JP5263087B2 - Cylinder device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylinder device having high practicality manufactured at low cost by employing a relief valve of not solenoid type, while the operating force applied to an operating member is effectively used for pressurizing brake fluid by a pressurizing piston during a failure. <P>SOLUTION: The cylinder device 110 can selectively create an operating-force-dependent pressurization state wherein brake fluid is pressurized by the operating force applied to a brake pedal 150, or a high-pressure-source-pressure-dependent pressurization state wherein brake fluid is pressurized dependent on the pressure from an external high-pressure source device 118 regardless of forward motion of an input piston 408. The cylinder device includes a mechanism in which the two states are switched by communication/non-communication between a reaction force chamber R4 provided between the input piston and a first pressurizing piston 402 to generate the pressure dependent on the operating force and a reservoir 122, and the communication/non-communication is switched by the pressure in the reaction force chamber, and a mechanism for switching the communication/non-communication dependent on the capacity of the reaction force chamber. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a cylinder device for pressurizing and supplying brake fluid to a brake device provided on a wheel.

  In the hydraulic brake system, for example, a cylinder device as described in the following patent document may be employed. The cylinder device has a function of pressurizing brake fluid using pressure input from an external high-pressure source, and is a so-called master cylinder with a fluid pressure boost function.

JP 2008-24098 A

  The cylinder device is normally in a high pressure source pressure dependent pressurization state in which the brake fluid is pressurized depending on the pressure from the high pressure source regardless of the advance of the input piston, and no power is supplied to the hydraulic brake system. In an electrical failure or the like, an operation force-dependent pressurization state in which the brake fluid is pressurized by an operation force applied to the operation member. The practicality of the cylinder device can be improved by improving the means for switching the operating state.

  This invention is made | formed in view of the said situation, and makes it a subject to provide a highly practical cylinder apparatus.

  In order to solve the above-described problem, the cylinder device of the present invention can be simply described regardless of the operation force-dependent pressurization state in which the brake fluid is pressurized by the operation force applied to the operation member and the forward movement of the input piston. A cylinder device that selectively realizes a high pressure source pressure dependent pressurizing state in which brake fluid is pressurized depending on a pressure from a high pressure source, and the two states are between an input piston and a pressurizing piston. A reaction force chamber that generates pressure according to the operating force, and a mechanism that switches between communication and non-communication with the reservoir, and switches the communication / non-communication by the pressure in the reaction force chamber, and the volume of the reaction force chamber And a mechanism for switching between the two.

  As will be described in detail later, for example, when an operation force-dependent pressurization state is established at the time of failure, the reaction force chamber and the reservoir are simply connected by realizing the communication state depending on the pressure of the reaction force chamber. The operating force corresponding to the residual pressure in the force chamber is not transmitted to the pressurizing piston, and in that sense, a loss occurs. According to the cylinder device of the present invention, since the mechanism for realizing the communication state is provided when the volume of the reaction force chamber is reduced, there is no loss of operating force, and the operating force applied to the operating member is reduced. Thus, it is effectively used for pressurizing the brake fluid by the pressurizing piston.

Aspects of the Invention

  In the following, some aspects of the invention that can be claimed in the present application (hereinafter sometimes referred to as “claimable invention”) will be exemplified and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is merely for the purpose of facilitating the understanding of the claimable inventions, and is not intended to limit the combinations of the constituent elements constituting those inventions to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiments, etc., and as long as the interpretation is followed, another aspect is added to the form of each section. In addition, an aspect in which some constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention.

  In each of the following terms, (1) corresponds to claim 1, (2) corresponds to claim 2, (3) corresponds to claim 3, (5) corresponds to claim 4, The combination of (6) and (7) is in claim 5, (10) in claim 6, (11) in claim 7, (12) in claim 8, (14) corresponds to claim 9, (15) corresponds to claim 10, and (18) corresponds to claim 11.

(1) A cylinder device for supplying pressurized brake fluid to the brake device in order to operate the brake device provided on the wheel,
A cylindrical housing with a closed front end;
A pressurizing piston disposed in the housing such that a pressurizing chamber for pressurizing the brake fluid is defined in front of the housing;
An input piston disposed behind the pressure piston and connected to the operation member at the rear end of the pressure piston;
An input chamber provided behind the pressurizing piston and into which pressure from a high pressure source is input;
(a) Prohibit transmission of the operating force applied to the operating member to the pressurizing piston, and apply brake fluid in the pressurizing chamber according to the pressure from the high pressure source input to the input chamber. A high pressure source pressure dependent pressurizing state that allows pressure, and (b) an operating force that transmits the operating force from the input piston to the pressurizing piston and allows the pressurization of the brake fluid in the pressurizing chamber by the operating force. An operating state switching mechanism that selectively realizes the dependent pressure state,
The operating state switching mechanism is
The reaction force chamber provided in the housing has a reaction force chamber that generates a pressure corresponding to the operation force, and the operation force is transmitted to the pressure piston in a state where the volume reduction of the reaction force chamber is prohibited. In the state where the volume reduction of the reaction force chamber is allowed, the operation force that exceeds the force corresponding to the pressure of the reaction force chamber is allowed to be transmitted to the pressurizing piston. And configured as
A pressure-based communication mechanism for allowing the reaction force chamber and the reservoir to communicate with each other in order to allow volume reduction of the reaction force chamber when the pressure of the reaction force chamber exceeds a set pressure;
A cylinder device having a volume-based communication mechanism for communicating the reaction force chamber and the reservoir when the volume of the reaction force chamber becomes smaller than a set volume.

  In brief, the cylinder device according to the aspect of the present aspect is configured such that the reaction force chamber is formed between the input piston and the pressure piston, and the operation state is switched depending on the state of the reaction force chamber. ing. Specifically, in a state where the reaction force chamber is sealed and volume reduction is prohibited, the high pressure source pressure dependent pressurization state is realized, and the reaction force chamber communicates with the reservoir, thereby In the state where the volume reduction is allowed, the operation force dependent pressurization state is realized. In the sealed state, the reaction force chamber is pressurized by the operating force and prohibits transmission of the operating force of the pressurizing piston from the input piston. That is, the operating force from the input piston is received by the pressure of the brake fluid in the reaction force chamber, and the transmission of the operating force to the pressurizing piston is prohibited. Since the reaction force chamber communicates with the reservoir, a reduction in the volume of the reaction force chamber is allowed, and the pressure increase of the brake fluid in the reaction force chamber is limited. Therefore, in the communication state in which the reaction force chamber and the reservoir communicate with each other, the reaction force chamber cannot receive all the operation force from the input piston, and the operation force except for the amount corresponding to the pressure in the reaction force chamber is not applied. It is transmitted to the pressure piston, and the operation force dependent pressurization state is realized. Incidentally, most of the operating force is transmitted to the pressurizing piston in a state where the reaction force chamber is at atmospheric pressure due to the communication state.

  The pressure-dependent communication mechanism provided in the cylinder device according to the aspect of the present aspect is a mechanism that realizes a communication state depending on the pressure of the reaction force chamber. In other words, the operation force applied to the operation member becomes more than a certain level. In this case, it is a mechanism that realizes an operation force-based pressurization state. According to this mechanism, it is possible to pressurize the brake fluid in the pressurizing chamber by the operating force when the driver operates the operating member with a certain operating force at the time of electrical failure. However, in the communication state realized by this mechanism, the reaction force chamber is at the set pressure, so that the operation force corresponding to the pressure, that is, the so-called residual pressure, is not transmitted to the pressurizing piston, and in that sense, a loss occurs. Will occur.

  In the cylinder device according to this aspect, the volume-dependent communication mechanism is provided as means for eliminating the loss. This mechanism has a function of communicating the reaction force chamber and the reservoir when the volume of the reaction force chamber is smaller than the set volume in the communication state realized by the pressure-dependent communication mechanism, In the communication state realized by this mechanism, the pressure in the reaction force chamber is atmospheric pressure. Therefore, when the communication state is realized by this mechanism, the loss of the operation force described above is eliminated, and most of the operation force is transmitted to the pressure piston. In other words, according to the cylinder device of this aspect, the operating force applied to the operating member is effectively used for pressurizing the brake fluid by the pressurizing piston in the event of failure.

  (2) The pressure-dependent communication mechanism is provided in a pressure-dependent communication mechanism communication path for communicating the reaction force chamber and the reservoir, and the pressure-dependent communication mechanism communication path. And a relief valve that opens only when the pressure exceeds a set pressure.

  As means for communicating the reaction force chamber and the reservoir, for example, an electromagnetic on-off valve that is in a closed state in an excited state can be employed. According to this on-off valve, when an electrical failure occurs, the valve is opened and the reaction force chamber and the reservoir can be communicated with each other. However, the cost of the electromagnetic on-off valve is high, and the adoption of the electromagnetic on-off valve contributes to raising the cost of the cylinder device. In that sense, according to the aspect of this section, a low-cost cylinder device is realized by employing a non-electromagnetic relief valve.

(3) The pressurizing piston has a bottomed hole that opens at a rear end, and has a main body portion and a flange portion formed on an outer periphery of the main body portion, and the pressurizing chamber is located in front of the main body portion. In addition, the input chamber is partitioned at the rear of the flange portion, and a counter chamber facing the input chamber is partitioned at the front of the flange portion, with the flange portion in between.
The input piston is fitted in the bottomed hole of the pressurizing piston so that the inter-piston chamber is partitioned by the pressurizing piston in front of the input piston,
The reaction force chamber is provided with an inter-chamber communication path that always communicates the counter chamber and the inter-piston chamber, so that the counter chamber and the inter-piston chamber are formed integrally.
The operating state switching mechanism prohibits a reduction in the volume of the reaction force chamber, thereby prohibiting contact between the input piston and the pressurizing piston, and transmitting the operating force to the pressurizing piston. Prohibit and allow contact with the pressurizing piston by the advance of the input piston in a state where the volume reduction of the reaction force chamber is allowed, and allow the operation force to be transmitted to the pressurizing piston. The cylinder device according to (1) or (2) configured as described above.

  The aspect of this section is an aspect in which the basic structure of the cylinder device is limited (hereinafter, the cylinder device having the above structure may be referred to as an input piston-free cylinder device for convenience). In the cylinder device according to this aspect, a reaction force chamber is formed by the counter chamber and the inter-piston chamber. When the pressure piston moves forward in a non-communication state where the reaction chamber and the reservoir do not communicate, the volume of the inter-piston chamber increases and the volume of the opposing chamber decreases accordingly, while the pressure piston moves backward. In this case, the volume of the opposing chamber decreases and the volume of the inter-piston chamber increases accordingly. That is, the suction and discharge of one brake fluid in these two fluid chambers and the suction and discharge of the other brake fluid are balanced. Therefore, in this state, the input piston and the pressurizing piston are allowed to move relative to each other when the input piston is not in contact with the pressurizing piston. In this state, pressure is introduced into the input chamber. Thus, a high pressure source pressure dependent pressurization state is realized.

  In the communication state where the reaction force chamber communicates with the reservoir, the volume of the reaction force chamber is allowed to decrease, and the volume of the inter-piston chamber is allowed to decrease, so that the input piston does not contact the pressure cylinder. An operation force-dependent pressurization state is realized. Incidentally, the “contact of the input piston with the pressurizing piston” in this section is not limited to the direct contact of the input piston with the pressurizing piston. It also means that the input piston makes indirect contact via some rigid body.

  In the cylinder device according to this aspect, the input piston is inserted into the bottomed hole provided in the pressurizing piston. Therefore, the high pressure seal that needs to be engaged with the input piston in order to partition each liquid chamber is between the inner peripheral surface of the bottomed hole of the pressure piston and the outer peripheral surface of the input piston, and the outer periphery of the input piston. One each may be disposed between the surface and the portion of the housing that slidably holds the input piston. Therefore, the frictional resistance against the movement of the input piston is relatively small, and the influence of the frictional resistance on the operational feeling of the operating member, that is, the influence on the operational feeling of the brake operation can be reduced.

  Further, in the cylinder device according to the aspect of this aspect, since the one reaction force chamber is formed by the communication between the inter-piston chamber and the counter chamber, the inter-piston chamber can be set to a relatively small volume. That is, the distance between the front end of the input piston and the bottom of the bottomed hole of the pressure piston can be made relatively small. Therefore, in the above communication state, it is possible to reduce the advance distance until the input piston comes into contact with the pressure piston. As a result, in the cylinder device of this section, it is possible to reduce the backlash feeling in the brake operation at the time of failure or the like and to improve the feeling of operation of the brake operation.

  (4) The cylinder device according to (3), further including an elastic force-based pressurizing mechanism that can pressurize the reaction force chamber by relying on an elastic force.

  The elastic force-based pressurizing mechanism in the aspect of this section is a mechanism for providing a so-called stroke simulator function. That is, in the cylinder device according to this aspect, in order to make the driver feel the operational feeling of the operation member in the high pressure source dependent pressurization state, the advance amount of the input piston, that is, the amount of advance of the input piston, that is, An operation reaction force according to the operation amount of the operation member can be applied. In other words, a mechanism for increasing the operation reaction force as the operation amount of the operation member increases by disposing an elastic member whose elastic deformation amount increases as the advance amount of the input piston increases. Is configured. In other words, it has a function of allowing the input piston to advance in accordance with the operation reaction force, that is, a function of allowing the operation of the operation member having an operation amount corresponding to the operation reaction force. In the cylinder device of this section, there is no need to dispose an elastic member such as a spring constituting the stroke simulator outside the cylinder device. According to the cylinder device of this section, the stroke simulator is arranged inside the cylinder device. Therefore, a compact cylinder device can be realized.

  The elastic force-based pressurizing mechanism can be configured to pressurize the reaction force chamber from at least one of the housing side, the pressurizing piston side, and the input piston side. That is, any one of a configuration in which the opposing chamber is pressurized from the housing side, a configuration in which the inter-piston chamber is pressurized from the pressure piston side, and a configuration in which the inter-piston chamber is pressurized from the input piston side is adopted. can do. The mode of adopting one of the two previous configurations can be considered as a mode in which the stroke simulator is disposed in the housing, and the mode of adopting the latter one configuration is that the stroke simulator is arranged in the input piston. It can be considered as an established aspect.

(5) The volume-based communication mechanism is
A communication path for a volume-based communication mechanism for communicating the reaction force chamber and the reservoir;
An open / close valve that is provided in the communication passage for the volume-dependent communication mechanism and opens only when the input piston moves forward and the volume of the inter-piston chamber becomes smaller than a set volume (3) The cylinder device according to item or (4).

  The mode of this section is a mode in which the configuration of the volume-dependent communication mechanism is specifically limited in the above-described input piston-free cylinder device. In view of the cost of the cylinder device, it is desirable that the on-off valve in this section is not mechanically actuated such as a solenoid valve but rather is mechanically actuated exclusively. When the pressure-based communication mechanism communication path described above is provided, at least a part of the communication path and the volume-based communication mechanism communication in this section may be shared.

(6) The input piston closes the front end of the main body member so as to partition the inner chamber inside the main body member and the main body member, and can project and retract with respect to the main body member. A front end member formed and a spring disposed in the inner chamber and biasing the front end member in a direction in which the front end member protrudes,
An elastic force-based pressurizing mechanism including the spring and capable of pressurizing the reaction force chamber depending on the elastic force is configured, and the front end of the main body member is moved to the pressurizing piston by the advance of the input piston. The operating force is transmitted to the pressurizing piston when it comes into contact with
The cylinder device according to (5), wherein the on-off valve is configured to open when a front end member of the input piston approaches a bottom of the bottomed hole of the pressurizing piston beyond a set distance. .

(7) The on-off valve is provided at the front end member of the input piston, and when the front end member approaches the set distance to the bottom of the bottomed hole, the engaging portion provided at the bottom of the bottomed hole Is configured to engage and open, and
The cylinder device according to (6), wherein the communication path for the volume-dependent communication mechanism includes the internal chamber of the input piston.

  The two modes can be considered as modes in which the stroke simulator is provided in the input piston in the input piston-free cylinder device. In addition, by utilizing the fact that the decrease in the volume of the reaction force chamber is related to the advance amount of the input piston with respect to the pressurizing piston, the open / close valve of the volume-dependent communication mechanism is configured to open in conjunction with the advance amount. It is an aspect. In the latter mode, the open / close valve of the volume-dependent communication mechanism is provided as a mechanical open / close valve at the front end of the input piston. In the state where the pressure-dependent communication mechanism allows the volume of the reaction force chamber to be reduced, the open / close valve is connected by opening the valve. After the open / close valve is opened, the operation based on the residual pressure in the pressure chamber is performed. No reaction force is generated, and it is possible to reduce a loss due to the use of the operation force other than the pressurization of the pressurizing piston.

(8) The input piston is
Each function as the spring, with one end supported by one of the main body member and the front end member, and the other end supported by the other of the main body member and the front end member. Two springs arranged in series and having different spring constants,
The two springs are sandwiched between one other end and the other other end, are floatingly supported by the two springs, and the elastic force of the two springs acts on the front end member. And a floating seat connecting the two springs,
The cylinder device according to (6) or (7), wherein the elastic force-based pressurizing mechanism includes the two springs and the floating seat.

  (9) In the process of retracting the front end member with respect to the main body member, when the amount of the retraction exceeds a set amount, displacement of the floating seat with respect to one of the main body member and the front end member is prohibited. Thus, the cylinder device according to the item (8), which is configured so that the amount of elastic deformation of one of the two springs does not increase.

  The modes described in the above two items are modes in which the elastic force-based pressurizing mechanism has two springs. According to the latter aspect, the elastic force-based pressurizing mechanism allows elastic deformation of both of the two springs at the initial stage of the brake operation, and prohibits elastic deformation of one of the two springs after the operation has progressed to some extent. Can be configured to. As a result, as described above, it is possible to realize a stroke simulator having an operation reaction force characteristic in which the operation reaction force gradient is small in the initial stage and the operation reaction force gradient is increased after the operation has progressed to some extent. . Further, by arbitrarily setting the spring constant difference between the two springs, it is possible to arbitrarily vary the difference between the initial operation reaction force gradient and the operation reaction force gradient at a stage where the operation has advanced to some extent. If the spring constant of the spring whose elastic deformation is prohibited when the operation has advanced to some extent is made smaller than the other spring constant, the difference in the operation reaction force gradient in the two stages can be made larger.

(10) The cylinder device is
An annular reaction force chamber having a main body portion and a flange portion formed on the outer periphery of the main body portion, the input chamber being partitioned in front of the main body portion, and the volume of which changes with its own advance and retreat. Is provided with an intermediate piston disposed in the housing in such a manner as to be partitioned in front of the flange portion,
The input piston is adapted to transmit the operating force to the intermediate piston from behind the intermediate piston;
The operating state switching mechanism prohibits the volume reduction of the reaction force chamber, thereby prohibiting the forward movement of the intermediate piston and prohibiting the transmission of the operating force to the pressurizing piston. In a state where the volume reduction of the intermediate piston is allowed, the intermediate piston is allowed to advance in a state where the main body portion of the intermediate piston is in contact with the pressure piston, and the operation force is transmitted to the pressure piston. The cylinder device according to (1) or (2), which is configured to allow

  The mode of this section is a mode in which the basic structure of the cylinder device is limited. The cylinder device having the above structure includes an intermediate piston, and the operation force-based pressurization state and the high-pressure source pressure-dependent pressurization state are switched depending on whether or not the movement of the intermediate piston is permitted. It will be called a lock-type cylinder device. In the cylinder device according to this aspect, the input chamber is provided between the pressurizing piston and the intermediate piston, and the reaction force chamber is provided as an annular liquid chamber in front of the intermediate piston. When the reaction force chamber and the reservoir are not in communication and the reaction force chamber is sealed, the pressure of the brake fluid in the reaction force chamber is a pressure corresponding to the operation force applied to the operation member. At the same time, the forward movement of the intermediate piston is prohibited. By inputting the pressure from the high pressure source into the input chamber in this state, a high pressure source dependent pressurization state is realized. On the other hand, in a state where the reaction force chamber and the reservoir communicate with each other, in the state, the intermediate piston is allowed to advance, and the intermediate piston is allowed to contact the pressure piston. The force is transmitted to the pressurizing piston, and the operating force-based pressurizing state is realized.

  In the cylinder device of this section, the volume of the input chamber can be reduced to the extent that the pressurizing piston and the intermediate piston come into contact with each other in the non-operating state, that is, in the state where the operating member is not operated. This makes it possible to pressurize the brake fluid in the pressurizing chamber by an operating force applied to the operating member immediately after the operating member starts to move in the event of a failure. Therefore, according to the cylinder device of the aspect of this section, it is possible to sufficiently secure the operation range of the operation member, that is, the operation stroke in the event of failure.

(11) The volume-based communication mechanism is
A communication path for a volume-based communication mechanism for communicating the reaction force chamber and the reservoir;
A reaction force chamber opening / closing valve that is provided in the communication passage for the volume-dependent communication mechanism and opens only when the intermediate piston moves forward and the volume of the reaction force chamber becomes smaller than the set volume. The cylinder device according to item (10).

  The mode of this section is a mode in which the configuration of the volume-dependent communication mechanism is specifically limited in the intermediate piston lock type cylinder device. In view of the cost of the cylinder device, it is desirable that the reaction force chamber opening / closing valve in this section is not mechanically operated such as a solenoid valve but rather is mechanically operated. When the pressure-based communication mechanism communication path described above is provided, at least a part of the communication path and the volume-based communication mechanism communication path in this section may be shared.

(12) The intermediate piston is in sliding contact with the inner peripheral surface of the housing via a seal fitted to the outer peripheral surface of the main body portion of the intermediate piston in front of the reaction force chamber.
The housing comprises:
The intermediate piston has a port that is provided on the inner peripheral surface of the housing at a position facing the front portion of the seal of the intermediate piston in a state where the intermediate piston is not advanced, and to which the communication passage for the volume-dependent communication mechanism is connected,
The reaction chamber open / close valve includes the seal and the port, and the intermediate piston moves forward to a position where the port faces a rear portion of the seal of the intermediate piston, so that the reaction chamber has the port. The cylinder device according to item (11), configured to communicate with the reservoir via

  The aspect of this section is configured so that the opening / closing valve of the volume-dependent communication mechanism opens in conjunction with the advance amount by utilizing the fact that the volume reduction of the reaction chamber is related to the advance amount of the intermediate piston. It is an aspect. The aspect of this section is an aspect in which the reaction chamber open / close valve is a mechanical open / close valve. In the state where the pressure-dependent communication mechanism allows the volume of the reaction force chamber to be reduced, the open / close valve is connected by opening the valve. After the open / close valve is opened, the operation based on the residual pressure in the pressure chamber is performed. No reaction force is generated, and it is possible to reduce a loss due to the use of the operation force other than the pressurization of the pressurizing piston.

  (13) The cylinder device according to any one of (10) to (12), wherein the intermediate piston and the input piston are integrally formed.

  In this mode, the relative movement between the intermediate piston and the input piston is always prohibited. The aspect of this section may be an aspect in which the intermediate piston and the input piston are coupled so as not to move relative to each other, or may be an aspect in which they are molded from one member into a single piston.

(14) The input piston is fitted to a rear end portion of the intermediate piston so that an inner chamber whose volume changes with relative movement with the intermediate piston is defined.
The cylinder device is
With the relative movement of the input piston and the intermediate piston in the direction in which the volume of the internal chamber decreases, the elastic force is applied to the input piston and the intermediate piston in the direction opposite to the relative movement. The cylinder device according to any one of (10) to (12), comprising a mechanism.

  The elastic force imparting mechanism in this aspect is a mechanism for providing a so-called stroke simulator function, similar to the elastic force-based pressurizing mechanism in the input piston-free cylinder device. The cylinder device according to the aspect of this section can apply an operation reaction force according to the operation amount of the operation member, similarly to the input piston-free type cylinder device including the elastic force-based pressurization mechanism described above. In other words, if it is turned upside down, it has a function of allowing the operation of the operation member having an operation amount corresponding to the operation reaction force.

(15) The cylinder device is
A spring disposed in the internal chamber and acting on the input piston and the intermediate piston in a direction in which the volume of the internal chamber increases in its own elastic force;
The cylinder device according to item (14), wherein the elastic force applying mechanism includes the spring.

  In short, the cylinder device according to this aspect is a cylinder device in which a stroke simulator is disposed in the internal chamber. According to the aspect of this section, since the spring constituting the stroke simulator is disposed in the internal chamber, a compact cylinder device can be realized.

(16) The cylinder device is
Each functions as the spring, with one end supported by one of the input piston and the intermediate piston and the other end supported by the other of the input piston and the intermediate piston. Two springs arranged in series in the inner chamber and having different spring constants;
The two springs are sandwiched between one other end and the other other end, and are floatingly supported by the two springs, and the volume of the inner chamber is increased by the elastic force of the two springs. A floating seat connecting the two springs to act on the input piston and the intermediate piston in the direction of
The cylinder device according to (15), wherein the elastic force applying mechanism includes the two springs and the floating seat.

  (17) In a process in which the input piston and the intermediate piston move relative to each other, when the volume of the internal chamber becomes a set volume or less, the displacement of the floating seat relative to one of the input piston and the intermediate piston is reduced. The cylinder device according to the item (8), which is configured so that the elastic deformation amount of one of the two springs does not increase by being prohibited.

  The modes described in the above two terms are modes in which the elastic force applying mechanism has two springs. The function of the elastic force applying mechanism is the same as the function of the elastic force-based pressurizing mechanism described with respect to the input piston-free cylinder device. Similar to the previous aspect, according to the aspect of this section, the operation reaction force characteristic is such that the operation reaction force gradient is small at the initial stage of operation of the operation member, and the operation reaction force gradient becomes large after the operation has progressed to some extent. A stroke simulator can be realized.

(18) The operating state switching mechanism is
An internal chamber communication state switching mechanism for communicating the internal chamber and the reservoir in the high pressure source pressure dependent pressurizing state and preventing the internal chamber and the reservoir from communicating in the operating force dependent pressurizing state; The cylinder device according to any one of (14) to (17).

  If the communication between the internal chamber and the reservoir is cut off by the internal chamber communication state switching mechanism, the internal chamber is sealed and the relative movement between the input piston and the intermediate piston is prohibited, so that the input piston and the intermediate piston are integrated. The forward movement is allowed. In this state, when the intermediate piston comes into contact with the pressure piston, the propulsive force of the input piston, that is, the operation force applied to the operation member is directly transmitted to the pressure piston. If the internal chamber non-communication state is realized at the initial stage of operation of the operation member, it is possible to pressurize the brake fluid with the operation force over almost the entire operation range of the operation member, and in the event of a failure, the operation stroke Will be used effectively. That is, it is possible to secure a sufficient operation stroke at the time of failure.

(19) It is configured to come into sliding contact with the inner peripheral surface of the housing through two seals fitted to the outer peripheral surface of the main body portion of the intermediate piston at positions separated from each other in the front-rear direction, and A first communication passage that connects the chamber and a piston-side port formed on the outer peripheral surface of the main body portion of the intermediate piston at a position between the two seals;
The housing comprises:
A second communication path connected to the reservoir from a housing-side port formed on the inner peripheral surface of the housing at a position facing the portion between the two seals of the intermediate piston when the intermediate piston is not advanced. Have
The internal chamber communication state switching mechanism is
Including the two seals, the first communication path, the second communication path, the piston side port, and the housing side port, and the piston side port and the housing side port are in a state where the intermediate piston is not advanced. By communicating, the inner chamber and the reservoir are communicated, and the forward movement of the intermediate piston causes the housing-side port to face the outer peripheral surface of the intermediate piston at a position on the rear side of the two seals. The cylinder device according to (18), wherein the piston chamber and the housing port are not in communication with each other, so that the internal chamber and the reservoir are not in communication.

  The mode of this section is a mode in which the structure of the internal chamber communication state switching mechanism is specifically limited. In short, in the cylinder device according to this aspect, a port communicating with the inner chamber is provided between two seals fitted to the intermediate piston, while the intermediate piston is slidably contacted on the inner peripheral surface of the housing. A port is provided in communication with the reservoir so that the two ports face each other in the non-operating state, and a seal provided on the rear side of the two seals is provided in the housing as the intermediate piston advances. The internal chamber communication state switching mechanism is configured so that the communication between the two ports is cut off when passing through the designated port. That is, it can be considered that the internal chamber communication state switching mechanism in the aspect of this section is configured by a mechanical on-off valve.

  According to the cylinder device of this aspect, the internal chamber non-communication state can be realized immediately after the intermediate piston moves from the non-operating state by optimizing the arrangement positions of the two ports and the two seals. Therefore, the function of sufficiently securing the operation stroke of the operation member at the time of failure as described above can be sufficiently secured.

  Although the two seals can be fitted to the inner peripheral surface of the housing and a housing-side port is provided between the two seals, an internal chamber communication state switching mechanism can be provided. In the case of a mechanism having a simple structure, the inner chamber needs to be sealed in the entire process of moving the intermediate piston, and therefore a sealed chamber that seals the port on the intermediate piston side over the entire range of the movement of the intermediate piston is necessary. Become. On the other hand, in the aspect of this section, two seals are fitted to the intermediate piston, and a port on the intermediate piston side is provided between them, so that the intermediate piston is located at any position in its forward range. Even in this case, the inner chamber can be sealed by a small space defined by the inner peripheral surface of the housing and the two seals. Therefore, according to the aspect of this item, the dimension in the moving direction of the intermediate piston of the cylinder device can be reduced, and the cylinder device can be made compact.

(20) The volume-based communication mechanism is
One of the two seals disposed on the rear side, the second communication passage, the housing side port, and the reaction force chamber and the housing side port in a state where the intermediate piston is not advanced Is not communicated, and the intermediate piston advances to a position where the housing side port faces the rear portion of the two seals of the intermediate piston, so that the reaction force chamber communicates with the reservoir through the port. The cylinder device according to item (19) configured as described above.

  In the aspect in which the internal chamber communication state switching mechanism is configured to include the two seals and the two ports, the aspect described above, in detail, the reaction force chamber opening / closing valve, A cylinder device embodying an aspect constituted by a seal fitted to an intermediate piston and a port provided in a housing. The seal fitted on the rear side of the two seals in the aspect of this section functions as the seal of the previous aspect, and the port provided on the housing side of the two ports in this section is in the previous aspect. Functions as a port. Moreover, the 2nd communicating path in the aspect of this term functions as a volume-dependent communication mechanism communicating path in the previous aspect.

  (21) In the case where the pressurizing piston is a first pressurizing piston, a first pressurizing chamber which is the pressurizing chamber is defined between itself and the first pressurizing piston behind itself, and (1) to (20) provided with a second pressurizing piston disposed in the housing in front of the first pressurizing piston so as to define a second pressurizing chamber in front of itself. The cylinder device according to any one of the items.

  The cylinder device according to this aspect is a cylinder device having two pressure pistons and two pressure chambers. Such a cylinder device is relatively long in the pressurizing direction of the pressurizing piston, that is, in the direction in which the input piston advances and retreats. Therefore, the advantage of downsizing due to the arrangement of the stroke simulator inside the cylinder device is effectively utilized for the cylinder device having two pressure pistons and two pressure chambers.

It is a schematic diagram showing the drive system and braking system of a hybrid vehicle which mount the cylinder apparatus of the Example of claimable invention. It is a figure which shows the hydraulic brake system comprised including the cylinder apparatus of 1st Example of claimable invention. It is a graph which shows the relationship between the operation amount of the operation member connected with a cylinder apparatus, and the operation reaction force provided to an operation member from a cylinder apparatus. It is a figure which shows the hydraulic brake system comprised including the cylinder apparatus used as the modification of 1st Example. It is a figure which shows the hydraulic brake system comprised including the cylinder apparatus of 2nd Example of claimable invention.

  Hereinafter, embodiments of the claimable invention will be described in detail with reference to the drawings. The claimable invention is not limited to the following examples and modifications, and can be implemented in various modes with various changes and improvements based on the knowledge of those skilled in the art.

≪Vehicle configuration≫
FIG. 1 schematically shows a drive system and a braking system for a hybrid vehicle equipped with the cylinder device of the first embodiment. In the vehicle, an engine 10 and an electric motor 12 are mounted as power sources, and a generator 14 that generates electric power by the output of the engine 10 is also mounted. These engine 10, electric motor 12, and generator 14 are connected to each other by a power split mechanism 16. By controlling the power split mechanism 16, the output of the engine 10 is divided into an output for operating the generator 14 and an output for rotating one of the four wheels 18 as a driving wheel, The output from the electric motor 12 can be transmitted to the drive wheels. That is, the power split mechanism 16 functions as a transmission related to the driving force transmitted to the drive wheels via the speed reducer 20 and the drive shaft 22. It should be noted that some components such as “wheel 18” are used as a general term, but when indicating that they correspond to any of the four wheels, the left front wheel, the right front wheel, the left rear wheel, The subscripts “FL”, “FR”, “RL”, and “RR” are assigned to the right rear wheel, respectively. According to this notation, the driving wheels in the vehicle are the wheel 18RL and the wheel 18RR.

  The electric motor 12 is an AC synchronous motor and is driven by AC power. The vehicle is provided with an inverter 24, and the inverter 24 can convert electric power from direct current to alternating current or from alternating current to direct current. Therefore, by controlling the inverter 24, the AC power output from the generator 14 is converted into the DC power for storing in the battery 26, or the DC power stored in the battery 26 is converted into the electric motor. 12 can be converted into AC power for driving the motor 12. Like the electric motor 12, the generator 14 has a configuration as an AC synchronous motor. That is, in the vehicle of the present embodiment, it can be considered that two AC synchronous motors are mounted, one of which is used mainly as an electric motor 12 for outputting a driving force, and the other is a generator 14. As mentioned above, it is mainly used for generating electricity by the output of the engine 10.

  The electric motor 12 can also generate power (regenerative power generation) by using the rotation of the wheels 18RL and 18RR as the vehicle travels. At this time, in the electric motor 12 connected to the wheels 18RL and 18RR, electric power is generated and a resistance force for stopping the rotation of the electric motor 12 is generated. Therefore, the resistance force can be used as a braking force for braking the vehicle. That is, the electric motor 12 is used as a regenerative brake means for braking the vehicle while generating electric power. Therefore, the vehicle is braked by controlling the regenerative brake together with the engine brake and a hydraulic brake described later. On the other hand, the generator 14 generates power mainly by the output of the engine 10, but also functions as an electric motor when power is supplied from the battery 26 via the inverter 24.

  In the present vehicle, the above-described brake control and various types of control relating to other vehicles are performed by a plurality of electronic control units (ECUs). Of the plurality of ECUs, the main ECU 40 has a function of supervising these controls. For example, the hybrid vehicle can run by driving the engine 10 and the electric motor 12. The driving of the engine 10 and the driving of the electric motor 12 are comprehensively controlled by the main ECU 40. . Specifically, the distribution of the output of the engine 10 and the output of the electric motor 12 is determined by the main ECU 40, and the engine ECU 42 that controls the engine 10, the electric motor 12, and the motor that controls the generator 14 based on the distribution. Commands for each control are output to the ECU 44.

  A battery ECU 46 that controls the battery 26 is also connected to the main ECU 40. The battery ECU 46 monitors the state of charge of the battery 26, and outputs a charge request command to the main ECU 40 when the amount of charge is insufficient. The main ECU 40 that has received the charge request command outputs a power generation command from the generator 14 to the motor ECU 44 in order to charge the battery 26.

  The main ECU 40 is also connected to a brake ECU 48 that controls the brake. The vehicle is provided with a brake operation member (hereinafter sometimes simply referred to as an “operation member”) that is operated by the driver, and the brake ECU 48 has a brake operation amount (hereinafter referred to as an operation amount of the operation member). May be simply referred to as an “operation amount”) and a brake control force that is a driver's force applied to the operation member (hereinafter, also referred to simply as “operation force”). The power is determined and this target braking force is output to the main ECU 40. The main ECU 40 outputs this target braking force to the motor ECU 44, and the motor ECU 44 controls the regenerative braking based on the target braking force, and the execution value thereof, that is, the generated regenerative braking force is supplied to the main ECU 40. Output to. In the main ECU 40, the regenerative braking force is subtracted from the target braking force, and the target hydraulic braking force to be generated in the hydraulic brake system 100 mounted on the vehicle is determined by the subtracted value. The main ECU 40 outputs the target hydraulic braking force to the brake ECU 48, and the brake ECU 48 performs control so that the hydraulic braking force generated by the hydraulic brake system 100 becomes the target hydraulic braking force.

≪Configuration of hydraulic brake system≫
The hydraulic brake system 100 mounted on the hybrid vehicle configured as described above will be described in detail with reference to FIG. In the following description, “front” represents the left side in FIG. 2, and “rear” represents the right side in FIG. In addition, “front side”, “front end”, “forward”, “rear side”, “rear end”, “reverse”, and the like are also represented in the same manner. In the following description, the character [] is a symbol used when a sensor or the like is shown in the drawings.

  FIG. 2 schematically shows a hydraulic brake system 100 provided in the vehicle. The hydraulic brake system 100 has a cylinder device 110 for pressurizing brake fluid. The driver of the vehicle can operate the cylinder device 110 by operating the operation device 112 connected to the cylinder device 110, and the cylinder device 110 pressurizes the brake fluid by its own operation. The pressurized brake fluid is supplied to a brake device 116 provided on each wheel via an antilock device 114 connected to the cylinder device 110. The brake device 116 generates a force for stopping the rotation of the wheel 18, that is, a hydraulic braking force, depending on the pressure of the pressurized brake fluid (hereinafter referred to as “output pressure”).

  The hydraulic brake system 100 has an external high pressure source device 118 for increasing the pressure of the brake fluid. The external high pressure source device 118 is connected to the cylinder device 110 via the pressure increasing / decreasing device 120. The pressure increasing / decreasing device 120 is a device that controls the pressure of the brake fluid that has been increased in pressure by the external high pressure source device 118, and increases the pressure of the brake fluid input to the cylinder device 110 (hereinafter referred to as "input pressure"). And reduce. The cylinder device 110 is configured to be operable by increasing or decreasing the input pressure. The hydraulic brake system 100 has a reservoir 122 that stores brake fluid under atmospheric pressure. The reservoir 122 is connected to each of the cylinder device 110, the pressure increasing / decreasing device 120, and the external high pressure source device 118.

  The operation device 112 includes a brake pedal 150 as an operation member, and an operation rod 152 connected to the brake pedal 150. The brake pedal 150 is rotatably held on the vehicle body. The operation rod 120 is connected to the brake pedal 150 at the rear end, and is connected to the cylinder device 110 at the front end. The operation device 112 includes an operation amount sensor [SP] 156 for detecting the operation amount of the brake pedal 150 and an operation force sensor [FP] 158 for detecting the operation force. The operation amount sensor 156 and the operation force sensor 158 are connected to the brake ECU 48, and the brake ECU 48 determines a target braking force based on detection values of these sensors.

  The brake device 116 is connected to the cylinder device 110 via the liquid passages 200 and 202. These fluid passages 200 and 202 are fluid passages for supplying the brake fluid pressurized to the output pressure by the cylinder device 110 to the brake device 116. An output pressure sensor [Po] 204 is provided in the liquid passage 202. Although not described in detail, each brake device 116 includes a brake caliper, a wheel cylinder (brake cylinder) and a brake pad attached to the brake caliper, and a brake disk that rotates with each wheel. . The fluid passages 200 and 202 are connected to the brake cylinder of each brake device 116 via the antilock device 114. Incidentally, the fluid passage 200 is connected to the brake devices 116FL and 116FR on the front wheel side, and the fluid passage 202 is connected to the brake devices 116RL and 116RR on the rear wheel side. The brake cylinder presses the brake pad against the brake disc depending on the output pressure of the brake fluid pressurized by the cylinder device 110. Due to the friction generated by the pressing, each brake device 116 generates a hydraulic braking force that stops the rotation of the wheel, and the vehicle is braked.

  The anti-lock device 114 is a general device, and simply has four pairs of on-off valves corresponding to each wheel. One of the pair of on-off valves is a pressure-increasing on-off valve. When the wheel is not locked, the valve is in an open state, and the other is a pressure-reducing on-off valve. When not locked, the valve is closed. When the wheel is locked, the pressure increasing on / off valve blocks the flow of brake fluid from the cylinder device 110 to the brake device 116, and the pressure reducing on / off valve allows the brake fluid to flow from the brake device 116 to the reservoir. And it is comprised so that the lock | rock of a wheel may be cancelled | released.

  The external high-pressure source device 118 is provided in the liquid passage from the reservoir 122 to the pressure increasing / decreasing device 120. The external high-pressure source device 118 includes a hydraulic pump 300 that increases the hydraulic pressure of the brake fluid, and an accumulator 302 that stores the increased brake fluid. Incidentally, the hydraulic pump 300 is driven by a motor 304. In addition, the external high-pressure source device 118 includes a high-pressure source pressure sensor [Pi] 306 for detecting the pressure of the brake fluid that is set to a high pressure. The brake ECU 48 monitors the detected value of the high-pressure source pressure sensor 306, and the hydraulic pump 300 is controlled and driven based on the detected value. With this control drive, the external high-pressure source device 118 always supplies brake fluid having a pressure equal to or higher than the set pressure to the pressure increasing / decreasing device 120.

  The pressure increasing / decreasing device 120 includes an electromagnetic pressure increasing linear valve 250 that increases the input pressure and an electromagnetic pressure reducing linear valve 252 that decreases the input pressure. The pressure increasing linear valve 250 is provided in the middle of the liquid passage from the external high pressure source device 118 to the cylinder device 110. On the other hand, the pressure-reducing linear valve 252 is provided in the middle of the liquid passage from the reservoir 122 to the cylinder device 110. Note that each fluid passage connected to the cylinder device 110 of the pressure-increasing linear valve 250 and the pressure-reducing linear valve 252 is a single fluid passage and is connected to the cylinder device 110. Further, an input pressure sensor [Pc] 256 for detecting the input pressure is provided in the liquid passage. The brake ECU 48 controls the pressure increase / decrease device 120 based on the detection value of the input pressure sensor 256.

  The pressure-increasing linear valve 250 is closed in a state where no current is supplied, that is, in a non-excited state, and by supplying current thereto, that is, in an excited state, The valve opens at the valve opening pressure corresponding to the supplied current. Incidentally, the valve opening pressure increases as the supplied current increases. On the other hand, the pressure-reducing linear valve 252 is opened when no current is supplied, and the maximum current in the set range is supplied during normal operation, that is, when power can be supplied to the system. When the valve is closed and the supplied current is reduced, the valve is opened at the valve opening pressure corresponding to the current. Incidentally, the valve opening pressure is configured to decrease as the current decreases.

≪Configuration of cylinder device≫
As shown in FIG. 2, the cylinder device 110 includes a housing 400 that is a housing of the cylinder device 110, a first pressure piston 402 and a second pressure piston 404 that pressurize brake fluid supplied to the brake device 116, The intermediate piston 406 moves forward by the pressure input from the external high pressure source device 118 and the input piston 408 to which the operation of the driver is input through the operating device 112 is configured. FIG. 2 shows a state where the cylinder device 110 is not operating, that is, a state where the brake operation is not performed. Incidentally, as is the case with a general cylinder device, this cylinder device 110 also communicates several fluid chambers in which brake fluid is stored, between those fluid chambers, and between these fluid chambers and the outside. Several communication passages are formed, and several seals are arranged between the components in order to ensure liquid tightness. These seals are general, and in consideration of the simplification of the description of the specification, the description thereof will be omitted unless particularly described.

  The housing 400 is mainly composed of two members, specifically, a first housing member 410 and a second housing member 412. The first housing member 410 has a generally cylindrical shape with the front end closed, and a flange 420 is formed on the outer periphery of the rear end. The first housing member 410 is fixed to the vehicle body at the flange 420. The first housing member 410 has three portions having different inner diameters, specifically, a front small diameter portion 422 having the smallest inner diameter located on the front side, and a rear large diameter portion 424 having the largest inner diameter located on the rear side. The intermediate portion 426 is located between the front small-diameter portion 422 and the rear large-diameter portion 424 and has an intermediate inner diameter between them.

  The second housing member 412 has a cylindrical shape having a front large-diameter portion 430 having a large outer diameter located on the front side and a rear small-diameter portion 432 having a small outer diameter located on the rear side. The second housing member 412 has a front end portion of the front large-diameter portion 430 at the rear large-diameter portion 424 in a state where a gap is provided in a step surface between the intermediate portion 426 and the rear large-diameter portion 424 of the first housing member 410. It is inserted. The first housing member 410 and the second housing member 412 are fastened to each other by a lock ring 434 fitted on the inner peripheral surface of the rear end portion of the first housing member 410.

  Each of the first pressurizing piston 402 and the second pressurizing piston 404 has a bottomed cylindrical shape whose rear end is closed, and is slidably fitted to the front small-diameter portion 422 of the first housing member 410. Are combined. The first pressure piston 402 is disposed behind the second pressure piston 404. Between the first pressurizing piston 402 and the second pressurizing piston 404, there is a first pressurizing chamber R1 for pressurizing the brake fluid supplied to the brake devices 116RL and RR provided on the two rear wheels. A second pressurizing chamber R2 for pressurizing the brake fluid supplied to the brake devices 116FL and FR provided on the two front wheels is defined in front of the second pressurizing piston 404. Is formed. The first pressure piston 402 and the second pressure piston 404 are fixed to the headed pin 460 erected at the rear end portion of the first pressure piston 402 and the rear end surface of the second pressure piston 404. The separation distance is limited within the set range by the pin holding cylinder 462 provided. In addition, compression coil springs (hereinafter also referred to as “return springs”) 464 and 466 are disposed in the first pressurizing chamber R1 and the second pressurizing chamber R2, respectively. The first pressurizing piston 402 and the second pressurizing piston 404 are biased in the direction in which they are separated from each other, and the second pressurizing piston 404 is biased rearward.

  The intermediate piston 406 has a shape having a bottomed cylindrical body 470 whose front end is closed and whose rear end is open, and a flange 472 provided at the rear end of the main body 470. Has been. The intermediate piston 406 is disposed behind the first pressurizing piston 402, the front part of the main body part 470 is on the rear side of the inner peripheral surface of the front small diameter part 422 of the first housing member 410, and the flange part 472 is intermediate. The inner peripheral surface of the part 426 is slidably fitted.

  In front of the intermediate piston 406, between the rear end portion of the first pressurizing piston 402, a fluid chamber to which brake fluid is supplied from the external high pressure source device 118, that is, pressure from the high pressure source device 118 is input. A liquid chamber (hereinafter may be referred to as an “input chamber”) R3 is defined. Incidentally, in FIG. 2, it is shown in the almost collapsed state. In addition, a space formed between the inner peripheral surface of the second housing member 412 and the outer peripheral surface of the main body portion 470 of the intermediate piston 406 exists inside the housing 400. The space is partitioned by a front end surface of the flange portion 472 of the intermediate piston 406 and a step surface between the front small-diameter portion 422 and the rear large-diameter portion 424 of the first housing member 410, so that an annular liquid chamber (hereinafter referred to as an annular liquid chamber). R4 is formed. In addition, a liquid chamber (hereinafter referred to as the same pressure as the input chamber R3) increases in volume with the forward movement of the intermediate piston 406 between the rear end of the flange portion 472 and the front end portion of the second housing member 412. R5 is defined as a compartment.

  The input piston 408 has a cylindrical shape with a front end opened and a rear portion closed. The input piston 408 is inserted into the housing 400 from the rear end side of the housing 400 while being in sliding contact with the inner peripheral surface of the second housing member 412, and is inserted into the intermediate piston 406. It can be moved relative to the input piston 408. More specifically, an annular seal holder 474 is fixedly attached to the rear end portion of the inner peripheral surface of the intermediate piston 406, and the input piston 408 is interposed via a seal held by the seal holder 474. Thus, the intermediate piston 406 can be advanced and retracted while being in sliding contact with the inner peripheral surface of the intermediate piston 406. Inside the input piston 408 and the intermediate piston 406 configured as described above, a liquid chamber (hereinafter sometimes referred to as “internal chamber”) R6 whose volume changes due to the relative movement of the intermediate piston 406 and the input piston 408 is provided. Is partitioned. Incidentally, the range of relative movement between the input piston 408 and the intermediate piston 406 is that the front end portion of the input piston 408 is locked by the stepped surfaces provided on the inner peripheral surface of the seal holder 474 and the intermediate piston 406, respectively. Limited. Further, the backward movement of the intermediate piston 406 is also restricted by the seal holder 474 coming into contact with the front end surface of the second housing member 412.

  In the internal chamber R6, a first reaction force spring 480 and a second reaction force spring 482, which are two compression coil springs, are disposed between the inner bottom surface of the intermediate piston 406 and the inner bottom surface of the input piston 408. . The first reaction force spring 480 is arranged in series behind the second reaction force spring 482, and a rod-shaped floating seat 484 with a hook is sandwiched between the reaction force springs and is supported in a floating manner. The front end portion of the first reaction force spring 480 is supported by the seat surface on the rear side of the floating seat 484, and the rear end portion is supported by the rear end portion of the input piston 408. The second reaction force spring 482 has a front end portion supported by the rear end portion of the intermediate piston 406 and a rear end portion supported by the front seat surface of the floating seat 484. The first reaction force spring 480 and the second reaction force spring 482 arranged in this manner cause the input piston 408 and the intermediate piston 406 to move away from each other, that is, the volume of the internal chamber R6 increases. Energized in the direction. The cylinder device 110 includes an elastic force applying mechanism constituted by a first reaction force spring 480 and a second reaction force spring 482, that is, a direction in which the input piston 408 and the intermediate piston 406 approach each other by the spring reaction force, In other words, a mechanism is provided that provides the input piston 408 and the intermediate piston 406 with an elastic force that opposes the relative movement between the input piston 408 and the intermediate piston 406 in the direction in which the volume of the internal chamber R6 decreases. Further, a buffer rubber 486 is fitted into the rear end portion of the floating seat 484, and the buffer rubber 486 abuts against the rear end surface of the input piston 408, so that the floating seat 484 and the input piston 408 are close to each other. Limited to range.

  An operation rod 152 is provided at the rear end of the input piston 408 so as to transmit the force applied to the brake pedal 150 operating force to the input piston 408 and to advance and retract the input piston 408 according to the operation amount of the brake pedal 150. The front ends of the are connected. A circular support plate 492 is attached to the operation rod 152, and a boot 494 is passed between the support plate 492 and the housing 400 to prevent dust at the rear of the cylinder device 110.

  The first pressurizing chamber R1 communicates with a liquid passage 202 connected to the antilock device 114 through a communication hole 500 whose opening serves as an output port, and a communication hole 502 provided in the first pressurizing piston 402 and The opening communicates with the reservoir 122 through a communication hole 504 serving as a drain port in a state where it is allowed to be non-communication. On the other hand, the second pressurizing chamber R2 communicates with the liquid passage 200 connected to the antilock device 114 via a communication hole 506 whose opening serves as an output port, and a communication hole provided in the second pressurizing piston 404. 508 and a communication hole 510 whose opening serves as a drain port communicate with the reservoir 122 in a state where it is allowed to be non-communication.

  The first pressurizing piston 402 has an outer diameter that is somewhat smaller than the inner diameter of the front small-diameter portion 422 of the first housing member 410, and a liquid passage 512 having a certain flow passage area is formed between them. . Further, the first housing member 410 is formed with a liquid passage 514 that communicates from the inner periphery of the front small diameter portion 422 to the stepped surface between the intermediate portion 426 and the rear large diameter portion 424. The input chamber R3 is connected to the pressure increasing / decreasing device 120 via the liquid passages 512 and 514, the back chamber R5, and a communication hole 516 whose opening serves as a connection port.

  The reaction force chamber R4 can communicate with the outside through a communication hole 518 whose opening serves as a connection port. The communication hole 518 is connected to the pressure increasing / decreasing device 120 by an external communication path 520. The external communication path 520 is provided with a relief valve 524. Further, a pressure sensor [Pr] 526 for detecting the pressure of the brake fluid in the reaction force chamber R4 is provided between the relief valve 524 and the communication hole 518.

  The intermediate piston 406 is provided with a communication hole 528 whose opening provided on the outer peripheral surface thereof is the piston-side port P1. The communication hole 528 is connected to the internal chamber R6, and the communication hole 528 forms one communication path (hereinafter sometimes referred to as “first communication path”). In addition, annular seals 530F and 530R are fitted into the outer peripheral surface of the intermediate piston 402 and in front of and behind the communication hole 528 at a relatively small interval. In addition, a communication path 532 is formed in the wall of the first housing member 410, and one end of the communication path 532 is open to the inner peripheral surface of the intermediate portion of the front small-diameter portion 422, and the first pressurization is performed. The outer peripheral surface of the piston 402 and the inner peripheral surface of the first housing member 410 communicate with the communication hole 504 through a gap. On the other hand, the other end of the communication path 532 opens to the inner peripheral surface of the rear end portion of the front small-diameter portion 422, and the opening at the other end serves as a housing side port P2. The communication path 532 is connected to the reservoir 122 via a communication hole 504, and one communication path (hereinafter sometimes referred to as “second communication path”) is formed by the communication path 532 and the communication hole 504. ing.

  Even when high-pressure brake fluid is supplied from the external high-pressure source device 118 to the input chamber R3 and the back chamber R5 via the pressure increasing / decreasing device 120, the intermediate piston 406 is not moved forward / backward. More specifically, the pressure receiving area at the front end of the main body portion 470 that defines the input chamber R3 and the pressure receiving area at the rear end of the collar portion 472 that defines the back chamber R5 are made substantially equal to each other by the pressure in the input chamber R3. The intermediate piston 406 is prevented from moving back and forth by balancing the force for moving the piston 406 backward with the force for moving the intermediate piston 406 forward by the pressure in the back chamber R5.

≪Cylinder unit operation≫
Hereinafter, the operation of the cylinder device 110 will be described. For convenience, the operation in the case of an electrical failure, that is, in the case where the power supply to the hydraulic brake system 100 is cut off, will be described before explaining the normal operation. Will be explained. At the time of failure, the pressure-increasing linear valve 250 and the pressure-decreasing linear valve 252 are in the closed state and the opened state, respectively.

  When the brake pedal 150 is not depressed at the time of failure, the reaction force chamber R4 has a relief valve 524 closed so that a reaction force chamber non-communication state that does not communicate with the reservoir 122 is realized. ing. In this state, the reaction force chamber R4 is prohibited from decreasing in volume, and the intermediate piston 806 cannot move forward. The piston side port P1 and the housing side port P2 face each other between the seal members 530F and 530R. That is, the piston side port P1 and the housing side port P2 are in communication with each other, and an internal chamber communication state in which the internal chamber R6 and the reservoir 122 are in communication is realized. In this state, the input piston 408 advances with respect to the intermediate piston 406 while contracting the first reaction force spring 480 and the second reaction force spring 482, and at this time, the volume of the inner chamber R6 is set to the brake of the inner chamber R6. The liquid flows out into the reservoir 122 and decreases.

  When the driver depresses the brake pedal 150, the input piston 408 starts moving forward, and the spring reaction forces of the first reaction force spring 480 and the second reaction force spring 482 increase. Due to these spring reaction forces, a forward force acts on the intermediate piston 406, and the brake fluid in the reaction force chamber R4 is pressurized by the flange 472 of the intermediate piston 406. Since the spring reaction force of the first reaction force spring 480 and the second reaction force spring 482 is a force that urges the input piston 408 rearward, the spring reaction force is an operation for the operation of the brake pedal 150. Acts as a reaction force. The characteristics of this operation reaction force will be described later.

  When the driver depresses the brake pedal 150 and the pressure of the brake fluid in the reaction force chamber R4 reaches the valve opening pressure of the relief valve 524 (hereinafter sometimes referred to as “set valve opening pressure”), the relief valve 524 opens. That is, the reaction force chamber R4 is communicated with the reservoir 122, the brake fluid in the reaction force chamber R4 is allowed to flow out to the reservoir 122, and the intermediate piston 406 is allowed to advance. The cylinder device 110 having such a structure includes a communication hole 518, an external communication passage 520, a communication passage formed by the pressure increasing / reducing device 120, and a relief valve 524, that is, a reaction force chamber R4. A pressure-based communication mechanism that selectively realizes a reaction force chamber communication state in which the reservoir 122 communicates and a reaction force chamber non-communication state in which the reservoir 122 does not communicate is provided. The communication path functions as a pressure-dependent communication mechanism communication path that communicates the reaction chamber R4 with the reservoir 122.

  When the seal member 530R passes through the housing side port P2 due to the advance of the intermediate piston 406, the communication between the piston side port P1 and the housing side port P2 is cut off, and the internal chamber non-communication state is realized. Therefore, the volume change of the internal chamber R6 is prohibited, the relative movement between the input piston 408 and the intermediate piston 406 is prohibited, and the input piston 408 and the intermediate piston 406 are advanced together. The cylinder device 110 having such a structure includes a mechanism including a first communication path, a second communication path, a piston side port, a housing side port, and seal members 530F and 530R, that is, an internal chamber R6 and a reservoir. An internal chamber communication state switching mechanism that selectively realizes an internal chamber communication state in which 122 communicates and an internal chamber non-communication state in which communication with 122 is not provided.

  Further, when the seal member 530R passes through the housing side port P2, the reaction force chamber R4 is communicated with the second communication path through a gap formed between the intermediate piston 406 and the first housing member 410. In detail, the intermediate piston 406 moves forward by a distance set by the positions of the housing side port P2 and the seal member 530R, and the volume of the reaction force chamber R4 is larger than the set volume corresponding to the distance. This is realized when the volume is reduced. When the volume of the reaction force chamber R4 is equal to or larger than the set volume, the communication is not realized. Therefore, it can be considered that the cylinder device 110 includes a reaction force chamber opening / closing valve that opens only when the volume of the reaction force chamber R4 is smaller than the set volume. The port P2 and the seal member 530R are included. The cylinder apparatus 110 having such a structure includes a communication path formed by a gap formed between the intermediate piston 406 and the first housing member 410 and a second communication path, and a reaction force chamber opening / closing valve. In other words, there is provided a volume-based communication mechanism that selectively realizes a reaction force chamber communication state in which the reaction force chamber R4 and the reservoir 122 communicate with each other and a reaction force chamber non-communication state in which the reaction force chamber R4 and the reservoir 122 communicate with each other. . The communication path functions as a communication path for a volume-based communication mechanism that communicates the reaction chamber R4 with the reservoir 122.

  As the intermediate piston 406 moves forward, the intermediate piston 406 moves the first pressurizing piston 402 forward while remaining in contact with the first pressurizing piston 402. Further, since the internal chamber non-communication state is realized, the input piston 408 and the intermediate piston 406 are integrated, and the operating force applied to the brake pedal 150 is directly transmitted to the first pressurizing piston 402. Will be. Therefore, the driver can push the first pressurizing piston 402 with his / her own force. As a result, the first pressurizing piston 402 moves forward, the transmission between the first pressurizing chamber R1 and the reservoir 122 is cut off, and the brake fluid in the first pressurizing chamber R1 is applied by the operating force applied to the brake pedal 150. Pressed. Incidentally, with the pressurization of the first pressurizing chamber R1, the second pressurizing piston 404 also moves forward, and the communication between the second pressurizing chamber R2 and the reservoir 122 is cut off similarly to the first pressurizing chamber R1, The brake fluid in the second pressurizing chamber R2 is also pressurized. As described above, an operation force-dependent pressurization state in which the brake fluid in the first pressurizing chamber R1 and the second pressurizing chamber R2 is pressurized by the operating force applied to the brake pedal 150 is realized. The hydraulic pressure corresponding to the driver's operating force is input.

  When the driver finishes the braking operation, that is, when the application of the operating force to the brake pedal 150 is released, the first pressurizing piston 402, the second pressurizing piston 404, and the intermediate piston 406 are connected to the return spring 464, 466 is returned to the initial position (the position shown in FIG. 2 where the rear end of the intermediate piston 406 is in contact with the front end of the second housing member 412). Further, the input piston 408 is moved to the initial position (the position shown in FIG. 2 by the first reaction force spring 480 and the second reaction force spring 482 together with the operation rod 152, and the front end portion is locked by the seal holder 474. Position).

  Under normal conditions, the pressure from the high pressure source device 118 is input to the input chamber R3 at a stage where the operation amount of the brake pedal 150 does not exceed a set amount described later. Therefore, the relief valve 524 is not opened even if the pressure in the reaction force chamber R4 becomes the set valve opening pressure due to the increase in the input pressure. That is, the reaction force chamber non-communication state in which the reaction force chamber R4 and the reservoir 122 do not communicate with each other is maintained, and the reaction force chamber R4 is kept sealed, thereby preventing the intermediate piston 406 from moving forward. In this state, even if the operation of the brake pedal 150 is advanced and the input piston 408 is advanced, the intermediate piston 406 is prohibited from moving forward. A reaction force chamber non-communication state in which the reservoir 122 is not communicated is not realized. Therefore, in the normal time, unlike the case of the above-described failure, the advancement of the input piston 408 relative to the intermediate piston 406 is always allowed. When the input piston 408 moves forward, the elastic force exerted on the input piston 408 by the elastic force application mechanism, that is, the first reaction force spring 480 and the second reaction force spring 482 acts as a resistance force. The elastic force acts as an operation reaction force with respect to the operation of the brake pedal 150.

  FIG. 3 is a graph showing the change in the operation reaction force with respect to the forward movement amount of the input piston 408, that is, the operation amount of the brake pedal 150 (hereinafter, sometimes referred to as “operation reaction force gradient”). In other words, the operation reaction force characteristics of the cylinder device 110 are graphs. As can be seen from this figure, when the operation amount of the brake pedal 150 increases, the operation reaction force increases accordingly. When the operation amount of the brake pedal 150 increases beyond a set amount (hereinafter sometimes referred to as “reaction force gradient change operation amount”), the change in the operation reaction force with respect to the change in the operation amount increases. In other words, the increase gradient of the operation reaction force is increased.

  The change in the operation reaction force having the characteristics shown in FIG. 3 is caused when the operation amount of the brake pedal 150 exceeds the reaction force gradient change operation amount, that is, when the advance amount of the input piston 408 exceeds the set amount. This is realized by preventing the pressure applied by the first reaction force spring 480, which is one of the two reaction force springs 880 and 882, from increasing. In the cylinder device 110, the spring constant of the first reaction force spring 480 is considerably smaller than the spring constant of the second reaction force spring 482. Therefore, in the range where the operation amount is relatively small, the change in the operation reaction force with respect to the change in the operation amount is considerably small. More specifically, the first reaction force spring 480 and the second reaction force spring 482 are both compressed and deformed within a relatively small range of operation. On the other hand, when the operation amount exceeds the reaction force gradient change operation amount, the buffer rubber 486 comes into contact with the rear end portion of the input piston 408, and the first reaction force spring 480 does not elastically deform, and the second reaction force spring. Only 482 is elastically deformed. With such a mechanism, when the brake pedal 150 is operated beyond the set amount, the increase gradient of the operation reaction force is increased. Due to such operational reaction force characteristics, the operational feeling of the brake pedal 150 is improved.

  As described above, in this vehicle, the hydraulic brake system 100 may generate the hydraulic braking force by an amount that exceeds the regenerative braking force of the target braking force. Extremely speaking, as long as the target braking force can be covered by the regenerative braking force, the hydraulic braking force by the hydraulic brake system 100 is not required. The cylinder device 110 is configured to generate an operation reaction force according to the operation amount of the brake pedal 150 without depending on the hydraulic braking force to be generated in a normal state. Speaking extremely, the cylinder device 110 has a function of allowing the operation of the brake pedal 150 in a state in which the brake fluid is not pressurized by the first pressure piston 402 and the second pressure piston 404. . That is, the cylinder device 110 has a stroke simulator suitable for a hybrid vehicle.

  When pressurizing the brake fluid in the first pressurizing chamber R1 and the second pressurizing chamber R2 by the first pressurizing piston 402 and the second pressurizing piston 404 in order to generate the hydraulic braking force during the braking operation. The pressure generated by the high pressure source device 118 may be input to the input chamber R3. Specifically, the pressure controlled by the pressure increasing / decreasing device 120 may be input to the input chamber R3 so that the hydraulic braking force exceeding the regenerative braking force can be obtained. If the maximum regenerative braking force that can be obtained by regenerative braking in this vehicle is defined as the maximum usable regenerative braking force, it is assumed that the hydraulic braking force is generated when the target braking force exceeds the maximum usable regenerative braking force. In this case, the operation amount of the brake pedal at the time when generation of the hydraulic braking force is started is generally the maximum regeneration hydraulic braking start operation amount in FIG. In the hydraulic brake system 100, the maximum regenerative hydraulic braking start operation amount is set to be slightly larger than the reaction force gradient change operation amount described above. Incidentally, even if the target braking force does not exceed the maximum available regenerative braking force due to the amount of charge of the battery 26, etc., the hydraulic braking force may be required. The pressure from the high pressure source device 118 may be input to the input chamber R3 at a stage that does not reach the hydraulic fluid braking start operation amount.

  When pressure is input to the input chamber R3, the first pressurizing piston 402 moves forward without depending on the operation force applied to the brake pedal 150 and without depending on the operation amount. The brake fluid in the first pressurizing chamber R1 is pressurized. Accordingly, the brake fluid in the second pressurizing chamber R2 is also pressurized by the second pressurizing piston 404. That is, regardless of the forward movement of the input piston 408, there is a high pressure source pressure dependent pressurization state in which the brake fluid is pressurized in the first pressurizing chamber R1 and the second pressurizing chamber R2 depending on the pressure from the high pressure source. Realized. The braking force by the cylinder device 110, that is, the hydraulic braking force is determined by the input brake fluid pressure. The input pressure is controlled by the pressure increasing / decreasing device 120, and a required pressure is input to the input chamber R3.

  Even during normal times, when the operation of the brake pedal 150 is terminated, the pressure-reducing linear valve 252 is opened, and the first pressure piston 402 and the second pressure piston 404 are respectively returned by return springs 464 and 466. The input piston 408 is returned to the initial position by the first reaction force spring 480 and the second reaction force spring 482.

  Here, it supplements about the action | operation at the time of failure. The set valve opening pressure of the relief valve 524 described above is the pressure in the reaction force chamber R4 when the operation amount of the brake pedal 150 becomes the set operation amount when the input pressure to the input chamber R3 is atmospheric pressure. Is set to The set operation amount is set to exceed the maximum regenerative hydraulic braking start operation amount in FIG. Therefore, in this cylinder device 570, when the brake pedal 150 is operated exceeding the set operation amount at the time of failure, the relief valve 524 is opened, and the operation force-based pressurization state is realized.

≪Features of this cylinder device≫
In the present cylinder device 110, when an operation force of a certain level or more is applied to the brake pedal 150, the relief valve 524 is opened to realize a reaction force chamber communication state. Generally, a relief valve is cheaper than an electromagnetic on-off valve, and the cylinder device 570 is a relatively inexpensive cylinder device.

  Assuming that the annular chamber communication state is realized only by opening the relief valve 524, if the intermediate piston 406 is moved forward by operating force, it corresponds to the valve opening pressure of the relief valve 524 in the reaction force chamber R4. Since there is a residual pressure, an operation in a state where an operation reaction force corresponding to the residual pressure is received is required. This causes a loss that the operating force is used for other than the pressurization by the first pressurizing piston 402 and the second pressurizing piston 404 at the time of failure. In view of that, in the present cylinder device 110, when the intermediate piston 406 moves forward by a set amount, that is, when the volume of the reaction force chamber R4 becomes the set volume, a mechanism for realizing a reaction force chamber communication state, That is, the above-described volume-based communication mechanism is provided. By realizing the communication state by this mechanism, there is no loss of operating force, and most of the operating force is transmitted to the first pressurizing piston 402. That is, according to the cylinder device 110, the operating force applied to the brake pedal 150 at the time of failure is effectively used for pressurizing the brake fluid by the first pressurizing piston 402.

  In the cylinder device 110, the volume of the input chamber R3 is reduced to the extent that the first pressurizing piston 402 and the intermediate piston 406 abut when the brake pedal 150 is not operated. Therefore, it is possible to pressurize the brake fluid in the first pressurizing chamber R1 and the second pressurizing chamber R2 by an operating force applied to the brake pedal 150 immediately after the brake pedal 150 starts to move at the time of failure. Has been. Therefore, in the cylinder device 110, the operating range of the brake pedal 150, that is, the operating stroke is sufficiently ensured when there is a failure.

  Further, in the present cylinder device 110, the input piston 408 and the intermediate piston 406 advance together as a result of prohibiting relative movement between the input piston 408 and the intermediate piston 406 in a state where the internal chamber is not in communication. In this state, the intermediate piston 406 contacts the first pressurizing piston 402, so that the propulsive force of the input piston 408, that is, the operating force applied to the brake pedal 150 is directly transmitted to the first pressurizing piston 402. It will be. In this cylinder device 110, the internal chamber is not communicated in the initial stage of operation of the brake pedal 150, and the brake fluid can be pressurized by operating force over almost the entire operable range of the brake pedal 150. Yes. That is, in this cylinder device 110, the operation stroke at the time of failure is also secured by this.

  The cylinder device 110 employs the above-described mechanism as a mechanism for realizing the internal chamber non-communication state. That is, two seal members 530F and 530R are fitted to the intermediate piston 406, the piston side port P1 is provided therebetween, and the communication between the piston side port P1 and the housing side port P2 is cut off as the intermediate piston 406 moves. It is configured to be. With such a configuration, even if the intermediate piston 406 is located at any position in the advance range thereof, the small space defined by the inner peripheral surface of the housing and the two sealing members 530F and 530R Chamber R6 is sealed. Therefore, the dimension in the moving direction of the intermediate piston 406 of the cylinder device 110 is reduced, and the size reduction is achieved.

  Further, in the present cylinder device 110, a first reaction force spring 480 and a second reaction force spring 482 constituting a stroke simulator are disposed inside the cylinder device 110, more specifically, in a dead space called an internal chamber R6. Yes. This also makes it more compact.

  Furthermore, since the cylinder device 110 has a structure in which the input piston 408 and the intermediate piston 406 are fitted together, the number of high-pressure seals that need to be engaged with the input piston 406 is reduced. Specifically, only two seals 540 and 542 shown in FIG. 2 are high pressure seals that engage the input piston 406. Therefore, in the high pressure source dependent pressurizing state, the frictional resistance against the movement of the input piston 408 is relatively small, and the influence of the frictional resistance on the operational feeling of the brake pedal 150, that is, the influence on the operational feeling of the brake operation is reduced. ing.

≪Modification≫
FIG. 4 shows a hydraulic brake system 100 that employs a modified cylinder device 570 instead of the cylinder device 110 of the first embodiment. The cylinder device 570 is roughly configured the same as the cylinder device 110 of the first embodiment. In the following description of the modified example, the configuration and operation different from the first embodiment will be described. The input piston 572 in the modified example has a columnar shape having a flange portion 574 at an intermediate portion thereof. On the outer peripheral surface of the front end portion of the input piston 572, annular seals 576F and 576R are respectively fitted at a relatively small interval. Further, the seals 576F and 576R are fitted to the input piston 572 so that the housing-side port P2 is located between them when the brake pedal 150 is not operated. That is, the cylinder device 570 is configured such that the input piston and the intermediate piston are integrally formed, and relative movement between the intermediate piston and the input piston is prohibited. Therefore, the cylinder device 570 is not provided with an internal chamber communication state switching mechanism and an elastic force applying mechanism.

  In the cylinder device 570 configured as described above, when an operation of the brake pedal 150 is started by the driver in an electrical failure, a forward force is applied to the input piston 572, and the flange portion 574 is operated. As a result, the brake fluid in the reaction force chamber R4 is pressurized. When the pressure of the pressurized brake fluid in the reaction force chamber R4 reaches the valve opening pressure of the relief valve 524, the relief valve 524 is opened, the reaction force chamber communication state is realized, and the input piston 572 moves forward. Permissible. Further, when the seal member 530 </ b> R passes through the housing-side port P <b> 2 by the advance of the input piston 572, the reaction force chamber R <b> 4 is communicated with the reservoir 122 via the communication path 532. Thus, this cylinder device 570 also includes two mechanisms, a pressure-based communication mechanism and a volume-based communication mechanism, as mechanisms for realizing the reaction force chamber communication state.

  FIG. 5 shows a hydraulic brake system 100 that employs a cylinder device 600 of the second embodiment instead of the cylinder device 110 of the first embodiment. Since the hydraulic brake system 100 has substantially the same configuration as the hydraulic brake system 100 adopting the cylinder device 110 of the first embodiment except for the cylinder device, the following description of the hydraulic brake system 100 will be given. It is assumed that this is performed only for the cylinder device 600.

≪Configuration of cylinder device≫
As shown in FIG. 5, the cylinder device 600 includes a housing 602 that is a housing of the cylinder device 600, a first pressure piston 604 and a second pressure piston 606 that pressurize brake fluid supplied to the brake device 116, It includes an input piston 608 in which the operation of the driver is input through the operation device 112. FIG. 5 shows a state where the cylinder device 600 is not operating, that is, a state where the brake operation is not performed.

  The housing 602 is mainly composed of two members, specifically, a first housing member 610 and a second housing member 612. The first housing member 610 has a generally cylindrical shape with the front end closed, and a flange 620 is formed on the outer periphery of the rear end. The first housing member 610 is fixed to the vehicle body at the flange 620. The first housing member 610 is divided into two parts having different inner diameters, specifically, a front small diameter part 622 having a small inner diameter located on the front side and a rear large diameter part 624 having a large inner diameter located on the rear side. Has been.

  The second housing member 612 has a cylindrical shape having a front large-diameter portion 630 with a large inner diameter located on the front side and a rear small-diameter portion 632 with a small inner diameter located on the rear side. The second housing member 612 is fitted into the rear large diameter portion 624 such that the front end portion of the front large diameter portion 630 is in contact with the step surface between the front small diameter portion 622 and the rear large diameter portion 624 of the first housing member 610. ing. The first housing member 610 and the second housing member 612 are fastened to each other by a lock ring 634 fitted into the inner peripheral surface of the rear end portion of the first housing member 610.

  The second pressurizing piston 606 has a bottomed cylindrical shape with a closed rear end, and is slidably fitted to the front small-diameter portion 622 of the first housing member 610. The first pressure piston 604 has a cylindrical main body 650 and a flange 652 provided at the rear end of the main body 650. The first pressurizing piston 604 is disposed behind the second pressurizing piston 606, and the front portion of the main body 650 is disposed on the rear side of the inner peripheral surface of the front small diameter portion 622 of the first housing member 610. 652 is slidably fitted to the inner peripheral surface of the front large-diameter portion 630 of the second housing member 612. Further, the inside of the main body 650 of the first pressure piston 604 is divided into two parts by a partition wall 654 provided at an intermediate position in the front-rear direction. That is, the first pressurizing piston 604 has a shape having two bottomed holes that open at the front end and the rear end, respectively.

  Between the first pressurizing piston 604 and the second pressurizing piston 606, there is a first pressurizing chamber R11 for pressurizing the brake fluid supplied to the brake devices 116RL and RR provided on the two rear wheels. A second pressurizing chamber R12 for pressurizing the brake fluid supplied to the brake devices 116FL and FR provided on the two front wheels is defined in front of the second pressurizing piston 606. Is formed. The first pressurizing piston 604 and the second pressurizing piston 606 are a headed pin 660 that is screwed up on the partition wall 654 of the first pressurizing piston 604 and a rear of the second pressurizing piston 606. The separation distance is limited within the set range by the pin holding cylinder 662 fixed to the end face. In addition, compression coil springs (hereinafter sometimes referred to as “return springs”) 664 and 666 are disposed in the first pressurizing chamber R11 and the second pressurizing chamber R12, respectively. The first pressurizing piston 604 and the second pressurizing piston 606 are set in directions away from each other, and the second pressurizing piston 606 is urged rearward.

  On the other hand, between the rear end portion of the second housing member 612 and behind the first pressure piston 604, specifically, behind the flange portion 652 of the first pressure piston 604, the external high-pressure source device 118 A fluid chamber to which the brake fluid is supplied, that is, a fluid chamber (hereinafter sometimes referred to as “input chamber”) R13 into which the pressure from the high pressure source device 118 is input is partitioned. Incidentally, in FIG. 2, it is shown in the almost collapsed state. In addition, a space formed between the inner peripheral surface of the second housing member 612 and the outer peripheral surface of the main body 650 of the first pressure piston 604 exists inside the housing 602. The space is partitioned by the front end surface of the flange portion 652 of the first pressurizing piston 604 and the step surface between the front small-diameter portion 622 and the rear large-diameter portion 624 of the first housing member 610, thereby A chamber is formed. This liquid chamber is a counter chamber R14 that faces the input chamber R13 with the flange 652 of the first pressure piston 604 interposed therebetween.

  The input piston 608 is a cylindrical main body 670 whose front end is opened and whose rear end is closed, and a front end member of the input piston 608, and can be projected and retracted with respect to the main body 670. An auxiliary piston 672, a first reaction force spring 674 that supports the auxiliary piston 672, a second reaction force spring 676 disposed in series behind the first reaction force spring 674, and the reaction force springs. And a rod-shaped floating seat 678 that is supported in a floating manner. Incidentally, the first reaction force spring 674 and the second reaction force spring 676 are both compression coil springs. The input piston 608 is inserted into the housing 400 from the rear end side of the housing 602 so as to be in sliding contact with the inner peripheral surface of the rear small-diameter portion 632 of the second housing member 612, and is inserted into the first pressure piston 604. A fluid chamber (hereinafter sometimes referred to as “inter-piston chamber”) R15 is defined between the first piston 604 and the input piston 608 in front of the input piston 608. Is formed.

  The auxiliary piston 672 includes a bottomed cylindrical outer cylinder member 680 having a hole in the front end surface thereof, a cylindrical inner cylinder member 682 fixedly fitted in the hole, and an inner part of the inner cylinder member 682. And a ball 684 and a biasing spring 686 housed in the housing. The front end surface of the inner cylinder member 682 is open, and the ball 684 is pressed forward against the opening by a spring reaction force of an urging spring 686 that is a compression coil spring so as to close the opening. The partition wall 654 positioned in front of the auxiliary piston 672 is provided with an engagement pin 688 that engages with the ball 684 by being inserted into the opening of the inner cylinder member 682. Therefore, when the auxiliary piston 672 moves forward and the distance between the auxiliary piston 672 and the partition wall portion 654 becomes equal to or smaller than the set distance, the engagement pin 688 pushes the ball 684 backward, and the opening of the inner cylinder member 682 is opened. become. As described above, in the auxiliary piston 672, the ball 684 is separated from the hole of the inner cylindrical member 682, so that a liquid chamber (hereinafter referred to as an “internal chamber”) that is partitioned in the inter-piston chamber R15 and the input piston 608 is formed. There is a case where an on-off valve is formed to communicate with R16. Incidentally, the internal chamber R16 of the input piston 608 is always at atmospheric pressure.

  The first reaction force spring 674 has a front end portion supported by the front end portion of the outer cylinder member 680 of the auxiliary piston 672 and a rear end portion supported by the seat surface on the front side of the floating seat 678. Further, the second reaction force spring 676 has a rear end portion supported by the rear end portion of the main body 670 of the input piston 608 and a rear end portion supported by the seat surface on the rear side of the floating seat 678. Therefore, the first reaction force spring 674 and the second reaction force spring 676 urge the auxiliary piston 672 in a direction protruding from the main body 670 of the input piston 608, and elastically support the auxiliary piston 672. . By the way, the auxiliary piston 672 has an engagement ring portion provided on the outer peripheral portion of the rear end of the outer cylinder member 680, and a step provided on the inner peripheral portion of the front end of the main body portion 670 of the input piston 608. By being stopped, it is limited to protrude forward from the main body 670 to some extent. Further, a buffer rubber 690 is fitted into the front end portion of the floating seat 678, and the buffer rubber 690 comes into contact with the rear end surface of the inner cylinder member 682 of the auxiliary piston 672. Access is limited to a certain range.

  A front end portion of the operation rod 152 is provided at the rear end portion of the input piston 608 in order to transmit the operation force of the brake pedal 150 to the input piston 608 and to advance and retract the input piston 608 according to the operation amount of the brake pedal 150. Are connected. Incidentally, the rear end portion of the input piston 608 is locked by the rear end portion of the rear small-diameter portion 632 of the second housing member 612, so that the backward movement is restricted. The operation rod 152 is provided with a disk-shaped spring seat 692, and a compression coil spring (hereinafter referred to as “return spring”) may be provided between the spring seat 692 and the second housing member 612. 694 is disposed, and the operation rod 152 is urged rearward by the return spring 694. Note that a boot 694 is passed between the spring seat 692 and the housing 602 so that the rear portion of the cylinder device 600 is protected from dust.

  The first pressurizing chamber R11 communicates with the liquid passage 202 connected to the antilock device 114 through a communication hole 700 whose opening serves as an output port, and a communication hole 702 provided in the first pressurizing piston 604 and The opening can communicate with the reservoir 122 through a communication hole 704 serving as a drain port. On the other hand, the second pressurizing chamber R12 communicates with the liquid passage 200 connected to the antilock device 114 through a communication hole 706 whose opening serves as an output port, and a communication hole provided in the second pressurizing piston 606. It is possible to communicate with the reservoir 122 through a communication hole 710 whose opening is a drain port. Further, the internal chamber R16 of the input piston 608 is provided with a communication hole 712 provided in the first pressurizing piston 604, a communication hole 714 provided in the second housing member 612, and a first housing member 610 with an opening opened. It communicates with the reservoir 122 through a communication hole 718 serving as a port. A portion located on the front side of the second housing member 612 has an outer diameter that is somewhat smaller than the inner diameter of the first housing member 610, and a liquid passage 720 having a certain flow passage area between the housing members 610 and 612. Is formed. The input chamber R13 is connected to the pressure increasing / decreasing device 120 via the liquid passage 720, a communication hole 722 provided in the second housing member 612, and a communication hole 724 whose opening serves as an input port.

  The facing chamber R14 can communicate with the outside through a communication hole 726 provided in the second housing member 612 and a communication hole 728 whose opening serves as a connection port. The main body portion 650 of the first pressurizing piston 604 has an outer diameter that is somewhat smaller than the inner diameter of the front small-diameter portion 622 of the first housing member 610, and a liquid passage 730 having a certain flow passage area therebetween. Is formed. The inter-piston chamber R15 can communicate with the outside through a liquid passage 730, a communication hole 732 provided in the first pressure piston 604, and a communication hole 734 whose opening serves as a connection port. The connection port of the communication hole 728 and the connection port of the communication hole 734 are communicated with each other by an external communication path 736, and an inter-chamber communication path for communicating the opposing chamber R14 and the inter-piston chamber R15 is formed. Yes. That is, in the present cylinder device 600, the counter chamber R14 and the piston chamber R15 are formed as one integral liquid chamber (hereinafter also referred to as “reaction force chamber”) R17 by the chamber communication passage. .

  As the first pressure piston 604 and the input piston 608 move relative to each other, the volume of the inter-piston chamber R15 increases and decreases, and the volume of the facing chamber R14 decreases and increases. The inter-chamber communication path has a function for absorbing the volume changes of the two liquid chambers. Incidentally, the cross-sectional area of the facing chamber R14 is substantially equal to the cross-sectional area of the inter-piston chamber R15, and only the first pressurizing piston 604 is moved relative to the housing 602 without moving the input piston 608 relative to the housing 602. It can be moved.

  In the cylinder device 600, the internal chamber R16 of the input piston 608 constitutes a part of the communication path from the reaction force chamber R17 to the reservoir 122. This communication path is opened and closed by an on-off valve provided in the auxiliary piston 672 described above.

  The external communication path 736 is branched in the middle thereof, and the branched communication path is connected to the pressure increasing / reducing device 120. The external communication path 736 is provided with a relief valve 738 for releasing the pressure to the reservoir 122 through the pressure increasing / decreasing device 120 when the pressure of the reaction force chamber R17 is high. More specifically, the reaction force chamber R17 can communicate with the reservoir 122 via the relief valve 738 and the pressure-reducing linear valve 252 included in the pressure-increasing / reducing device 120. The relief valve 738 is opened when the pressure in the reaction force chamber R17 is higher than a threshold pressure input to the input chamber R13, and the pressure input to the input chamber R13. Is the atmospheric pressure, the valve is opened when the pressure in the reaction force chamber R17 increases from the atmospheric pressure above the threshold pressure. With this configuration, in the cylinder device 600, the pressure in the reaction chamber R17 is set to a set pressure (hereinafter referred to as “set valve opening”) by the relief valve 738 and the communication passage for communicating the reaction force chamber R17 and the reservoir 122. This is a communication state switching mechanism that allows the reaction force chamber R17 and the reservoir 122 to communicate with each other only when the pressure exceeds a certain pressure.

≪Cylinder unit operation≫
First, the operation of the cylinder device 600 at the time of electrical failure will be described. At the time of failure, when the driver starts depressing the brake pedal 150, the main body 670 of the input piston 608 starts to move forward. Thus, the pressure in the reaction force chamber R17 increases until the pressure in the reaction force chamber R17 reaches the set valve opening pressure. As described above, since the cross-sectional area of the inter-piston chamber R15 and the cross-sectional area of the counter chamber R14 are substantially the same, the first pressurizing piston 604 cannot be advanced even when the input piston 608 advances. . Further, since the volume change of the inter-piston chamber R15 is prohibited, the auxiliary piston 672 causes the first reaction force spring 674 and the second reaction force to increase due to the increase in the pressure of the reaction force chamber R17, that is, the pressure of the inter-piston chamber R15. While the reaction force spring 676 is contracted, the reaction force spring 676 is pushed into the main body 670. In other words, the reaction force spring 676 is retracted by an amount corresponding to the pressure in the reaction force chamber R17.

  The amount of elastic deformation of the first reaction force spring 674 and the second reaction force spring 676, that is, the amount of compression, depends on the increase in the pressure of the reaction force chamber R17. In other words, the reaction force chamber R17 is pressurized according to the elastic force of the first reaction force spring 674 and the second reaction force spring 676, and the operation reaction force according to the pressure of the reaction force chamber R17 is input. It is given to the operating member via the piston. That is, the pressure applied by the two springs 674 and 676 acts as a resistance force against the forward movement of the input piston 608, that is, as an operation reaction force against the operation of the brake pedal 150. The cylinder device 600 having such a structure has a mechanism including an auxiliary piston 672, a first reaction force spring 674, a second reaction force spring 676, and a floating seat 678, that is, a reaction force chamber R17. An elastic force-based pressurizing mechanism is provided which can pressurize depending on the elastic force of the first reaction force spring 674 and the second reaction force spring 676.

  The operation reaction force depends on the advance amount of the input piston 608, that is, the operation amount of the brake pedal 150. The magnitude of the operation reaction force with respect to the operation amount of the brake pedal has the characteristics as shown in FIG. As can be seen from this figure, when the operation amount of the brake pedal 150 increases, the operation reaction force increases accordingly, and when the operation amount of the brake pedal 150 increases beyond the reaction force gradient change operation amount, the operation with respect to the change in the operation amount is performed. The reaction force changes greatly. That is, the increasing gradient of the operation reaction force is increased. Such a characteristic is that, when the operation amount of the brake pedal 150 exceeds the reaction force gradient change operation amount, the pressure applied by the first reaction force spring 674 which is one of the two reaction force springs 674 and 676 does not increase. It is realized by doing so. Specifically, the rear end surface of the inner cylinder member 682 of the auxiliary piston 672 abuts against a buffer rubber 690 fitted in the floating seat 678, so that the first reaction force spring 674 does not elastically deform, and the second reaction force spring Only 676 is elastically deformed. In the cylinder device 600, the spring constant of the first reaction force spring 674 is considerably smaller than the spring constant of the second reaction force spring 676. Therefore, the change gradient of the operation reaction force is reduced in a range where the operation amount is relatively small, and is considerably increased when the operation amount exceeds the reaction force gradient change operation amount.

  The set valve opening pressure of the relief valve 738 is such that when the pressure from the high pressure source device 118 is not input to the input chamber R13, the operation amount of the brake pedal 150 is greater than the maximum regenerative hydraulic braking start operation amount in FIG. It is set to the pressure of the reaction force chamber R17 when it becomes large to some extent. When the operation amount of the brake pedal 150 increases and the operation force applied to the brake pedal 150 becomes the set threshold operation force, the relief valve 738 is opened and the reaction force chamber R17 is opened. The pressure reducing linear valve 252 communicates with the reservoir 122. When this communication state is realized, the forward movement of the input piston 608 is allowed while the volume reduction of the reaction force chamber R17 is allowed while the pressure of the reaction force chamber R17 is maintained at the set valve opening pressure. Become. In the cylinder device 600 having such a structure, the communication state switching mechanism that allows the reaction force chamber R17 and the reservoir 122 to communicate with each other does not communicate with the reaction force chamber communication state in which the reaction force chamber R17 and the reservoir 122 communicate with each other. This is a pressure-based communication mechanism that selectively realizes the force chamber non-communication state based on the pressure of the reaction force chamber. The communication path in the communication state switching mechanism is a pressure-dependent communication mechanism communication path that communicates the reaction force chamber R17 with the reservoir 122.

  When the operation of the brake pedal 150 proceeds in this state, the auxiliary piston 672 moves forward together with the input piston 608 to some extent. When the distance between the auxiliary piston 672 and the partition wall portion 654 is equal to or less than the set distance, the engagement pin 688 provided on the partition wall portion 654 is a ball that constitutes the on-off valve provided on the auxiliary piston 672. Push 684 backwards. As a result, the reaction force chamber R17 communicates with the reservoir 122 via the internal chamber R16 of the input piston 608. The cylinder device 600 having such a structure includes a communication path communicating from the reaction force chamber R17 to the reservoir 122 and a reaction force chamber opening / closing valve, that is, the reaction force chamber R17 and the reservoir 122. It is provided with a volume-based communication mechanism that selectively realizes a reaction force chamber communication state in which communication is established and a reaction force chamber non-communication state in which communication is not established, depending on the volume of the reaction force chamber. In addition, this communication path is a communication path for a volume-based communication mechanism that communicates the reaction force chamber R17 with the reservoir 122.

  By realizing the reaction force chamber communication state by the volume-based communication mechanism, the reaction force chamber R17 is set to atmospheric pressure, and the input piston 608 is allowed to move relatively freely and comes into contact with the partition wall portion 654. The first pressurizing piston 604 is directly pressed. Therefore, in that state, the driver's operating force applied to the brake pedal 150 is directly transmitted to the first pressurizing piston 604, and the driver presses the first pressurizing piston 604 with his / her own operating force. It can be done. Since the pressure-reducing linear valve 252 is in an open state, the input chamber R13 is always at atmospheric pressure and does not generate a resistance force against the forward movement of the first pressurizing piston 604.

  As the first pressurizing piston 604 advances, transmission between the first pressurizing chamber R11 and the reservoir 122 is cut off, and the brake fluid in the first pressurizing chamber R11 is pressurized by the operating force of the driver. Incidentally, with the pressurization of the first pressurizing chamber R11, the second pressurizing piston 606 also advances, and similarly to the first pressurizing chamber R11, the communication between the second pressurizing chamber R12 and the reservoir 122 is cut off. The brake fluid in the first pressurizing chamber R11 is also pressurized. In this way, an operation force-dependent pressurization state in which the brake fluid is pressurized in the first pressurizing chamber R1 and the second pressurizing chamber R2 by the operating force applied to the brake pedal 150 is realized, and the brake device 116 has The hydraulic pressure corresponding to the driver's operating force is input.

  When the driver finishes the brake operation, that is, when the operation force is no longer applied to the brake pedal 150, the first pressurizing piston 604 and the second pressurizing piston 606 are initialized by the return springs 664 and 666, respectively. The position is returned to the position (the position shown in FIG. 5 where the rear end of the first pressure piston 604 comes into contact with the rear end of the second housing member). The input piston 608 is returned to the initial position (position shown in FIG. 5, the rear end being locked by the rear end of the second housing member) by the return spring 694 together with the operation rod 152. .

  Next, the normal operation will be described. Under normal conditions, the maximum current is supplied to the pressure-reducing linear valve 252 and is closed, but the forward movement of the input piston 608, the pressure change in the reaction force chamber R17, and the elastic force-based pressurizing mechanism The relationship between the operation, the operation amount of the brake pedal 150 and the operation reaction force, etc. is not different from the case of the above-mentioned failure. Under normal conditions, the pressure from the high pressure source device 118 is input to the input chamber R13 when the operation amount of the brake pedal 150 does not exceed the maximum regenerative hydraulic braking start operation amount. Incidentally, the relief valve 738 is not opened even if the pressure of the reaction force chamber R17 becomes the above-mentioned set valve opening pressure due to the increase of the input pressure.

  If the pressure generated by the high pressure source device 118 is input to the input chamber R13 in order to generate the hydraulic braking force during the braking operation, the first pressure piston 604 and the second pressure piston 606 are generated by the pressure. Is advanced, and the brake fluid in the first pressurizing chamber R11 and the second pressurizing chamber R12 is pressurized. When the brake fluid is pressurized depending on the pressure input to the input chamber R13, the reaction force chamber R17 is sealed. Therefore, if the operation does not exceed the maximum regenerative hydraulic braking start operation amount, The front end of the piston 608 does not contact the partition wall 654 of the first pressure piston 604. Further, since the pressure receiving area of the front end of the flange portion 652 of the first pressure piston 604 and the pressure receiving area of the front end surface of the input piston 608 are substantially equal, even if the first pressure piston 604 moves forward, The advance / retreat of the input piston 608 is not affected. That is, the operation amount and the reaction force of the brake pedal 150 are not changed.

  By performing the operation as described above, the first pressurizing piston 604 and the second pressurizing piston 606 are applied to the brake pedal 150 when pressurizing the brake fluid depending on the pressure of the input chamber R13. Therefore, the brake fluid in the first pressurizing chamber R11 and the second pressurizing chamber R12 is pressurized without depending on the operating force and without depending on the operation amount. That is, regardless of the forward movement of the input piston 608, there is a high pressure source pressure dependent pressurization state in which the brake fluid is pressurized in the first pressurization chamber R11 and the second pressurization chamber R12 depending on the pressure from the high pressure source. Realized. The braking force by the cylinder device 600 in this case, that is, the hydraulic braking force is determined by the input brake fluid pressure. Normally, the input pressure is controlled by the pressure increasing / decreasing device 120, and a required pressure is input to the input chamber R13.

  In normal times, the pressure controlled by the pressure increasing / decreasing device 120 may be input to the input chamber R3 so that a hydraulic braking force exceeding the regenerative braking force can be obtained. In many cases, the hydraulic braking force may be generated when the target braking force exceeds the maximum available regenerative braking force. Incidentally, even if the target braking force does not exceed the maximum available regenerative braking force due to the charge amount of the battery 26, etc., the hydraulic braking force may be required. The pressure from the high pressure source device 118 may be input to the input chamber R13 at a stage that does not reach the hydraulic fluid braking start operation amount.

  As described above, in this vehicle, the hydraulic brake system 100 may generate the hydraulic braking force by an amount that exceeds the regenerative braking force of the target braking force. Extremely speaking, as long as the target braking force can be covered by the regenerative braking force, the hydraulic braking force by the hydraulic brake system 100 is not required. The cylinder device 600 is configured to generate an operation reaction force according to the operation amount of the brake pedal 150 without depending on the hydraulic braking force to be generated in a normal state. Speaking extremely, the cylinder device 110 has a function of permitting the operation of the brake pedal 150 in a state where the brake fluid is not pressurized by the first pressure piston 604 and the second pressure piston 606. . That is, this cylinder device 600 has a stroke simulator suitable for a hybrid vehicle.

  Even during normal times, if the operation of the brake pedal 150 is terminated, the pressure-reducing linear valve 252 is opened, and the first pressure piston 604 and the second pressure piston 606 are respectively returned by return springs 664 and 666. The input piston 608 is returned to the initial position by the return spring 694.

≪Features of this cylinder device≫
In the cylinder device 600, the pressure-based communication mechanism is provided as a mechanism for communicating the reaction force chamber R17 with the reservoir 122, and a relief valve 738 is employed in the mechanism. Generally, a relief valve is less expensive than an electromagnetic on-off valve, and the cylinder device 600 is relatively inexpensive.

  In the cylinder device 600, when the volume of the reaction force chamber becomes smaller than the set volume in the communication state realized by the pressure-based communication mechanism, the reaction force chamber R17 and the reservoir 122 are communicated by the volume-based communication mechanism. It is done. Therefore, the communication state is realized by this mechanism, so that at the time of failure, loss of the operating force is eliminated, and most of the operating force is transmitted to the first pressurizing piston 604. That is, according to the cylinder device 600, the operating force applied to the brake pedal 150 at the time of failure is effectively used for pressurizing the brake fluid by the first pressurizing piston 604.

  In the cylinder device 600, the input piston 608 is inserted into a bottomed hole provided in the first pressure piston 604. Therefore, the high pressure seal that needs to be engaged with the input piston 608 to partition each liquid chamber is between the inner peripheral surface of the bottomed hole of the first pressurizing piston 604 and the outer peripheral surface of the input piston 608. Only one each is disposed between the outer peripheral surface of the input piston 608 and the second housing member 612. Specifically, the seal 750 and the seal 752 are provided. Therefore, the frictional resistance with respect to the movement of the input piston 608 is relatively small, and the influence of the frictional resistance on the operation feeling of the operation member, that is, the influence on the operation feeling of the brake operation is reduced.

  In the cylinder device 600, the stroke simulator is configured including an elastic force-based pressurizing mechanism that pressurizes the reaction force chamber R17. Therefore, the first reaction force spring 674 and the second reaction force spring 676 constituting the stroke simulator. Since it is disposed inside the cylinder device 600, more specifically, inside the input piston 608, it is a compact cylinder device.

  Further, in the cylinder device 600, one reaction force chamber R17 is formed by communication between the inter-piston chamber R15 and the counter chamber R14, and the inter-piston chamber R15 has a relatively small volume. That is, the distance between the front end of the input piston 608 and the bottom of the bottomed hole of the first pressure piston 604 is relatively small. Therefore, the advance distance until the input piston 608 contacts the first pressurizing piston 604 is reduced. As a result, the cylinder device 600 has less play in the brake operation at the time of failure or the like, and the operation feeling of the brake operation is good.

  In the cylinder device 600, the first reaction force spring 480 and the second reaction force spring 482 constituting the stroke simulator are disposed inside the cylinder device 110, more specifically, inside the input piston 608. Therefore, since it is disposed, it is compact.

  110: Cylinder device 116: Brake device 118: External high pressure source device 122: Reservoir 150: Brake pedal (operating member) 400: Housing 402: First pressurizing piston (pressurizing piston) 406: Intermediate piston 408: Input piston 470: 472: first reaction force spring (elastic force applying mechanism) 482: second reaction force spring (elastic force applying mechanism) 484: floating seat 520: external communication path 524: relief valve (pressure-dependent communication mechanism) ) R1: first pressurizing chamber R2: second pressurizing chamber R3: input chamber R4: reaction force chamber R5: back chamber R6: reaction force chamber 572: input piston 574: flange 576F: seal 576R: seal 600: cylinder Device 602: Housing 604: First pressurization Piston (pressurizing piston) 608: input piston 650: main body portion 652: collar portion 670: main body portion (main body member) 672: auxiliary piston (front end member) 674: first reaction force spring (elastic force applying mechanism) 676: first 2 reaction force spring (elastic force applying mechanism) 678: floating seat 680: outer cylinder member 682: inner cylinder member 684: ball 686: biasing spring 688: engagement pin 736: external communication path 738: relief valve (pressure-dependent communication) 750: Seal 752: Seal R11: First pressurizing chamber R12: Second pressurizing chamber R13: Input chamber R14: Opposite chamber R15: Inter-piston chamber R16: Internal chamber R17: Reaction force chamber

Claims (11)

A cylinder device that supplies pressurized brake fluid to the brake device in order to operate a brake device provided on the wheel,
A cylindrical housing with a closed front end;
A pressurizing piston disposed in the housing such that a pressurizing chamber for pressurizing the brake fluid is defined in front of the housing;
An input piston disposed behind the pressure piston and connected to the operation member at the rear end of the pressure piston;
An input chamber provided behind the pressurizing piston and into which pressure from a high pressure source is input;
(a) Prohibit transmission of the operating force applied to the operating member to the pressurizing piston, and apply brake fluid in the pressurizing chamber according to the pressure from the high pressure source input to the input chamber. A high pressure source pressure dependent pressurizing state that allows pressure, and (b) an operating force that transmits the operating force from the input piston to the pressurizing piston and allows the pressurization of the brake fluid in the pressurizing chamber by the operating force. An operating state switching mechanism that selectively realizes the dependent pressure state,
The operating state switching mechanism is
The reaction force chamber provided in the housing has a reaction force chamber that generates a pressure corresponding to the operation force, and the operation force is transmitted to the pressure piston in a state where the volume reduction of the reaction force chamber is prohibited. In the state where the volume reduction of the reaction force chamber is allowed, the operation force that exceeds the force corresponding to the pressure of the reaction force chamber is allowed to be transmitted to the pressurizing piston. And configured as
A pressure-based communication mechanism for allowing the reaction force chamber and the reservoir to communicate with each other in order to allow volume reduction of the reaction force chamber when the pressure of the reaction force chamber exceeds a set pressure;
A cylinder device having a volume-based communication mechanism for communicating the reaction force chamber and the reservoir when the volume of the reaction force chamber becomes smaller than a set volume.   The pressure-dependent communication mechanism is provided in a pressure-dependent communication mechanism communication path for communicating the reaction force chamber and the reservoir, and the pressure-dependent communication mechanism communication path, and the pressure of the reaction force chamber is set to a set pressure. The cylinder device according to claim 1, wherein the cylinder device includes a relief valve that opens only when the pressure exceeds. The pressurizing piston has a bottomed hole that opens at the rear end, and has a main body portion and a flange portion formed on the outer periphery of the main body portion, and the pressurizing chamber is in front of the main body portion, The input chamber is partitioned at the rear of the buttock, and the opposite chamber facing the input chamber is partitioned at the front of the buttock with the buttock sandwiched therebetween,
The input piston is fitted in the bottomed hole of the pressurizing piston so that the inter-piston chamber is partitioned by the pressurizing piston in front of the input piston,
The reaction force chamber is provided with an inter-chamber communication path that always communicates the counter chamber and the inter-piston chamber, so that the counter chamber and the inter-piston chamber are formed integrally.
The operating state switching mechanism prohibits a reduction in the volume of the reaction force chamber, thereby prohibiting contact between the input piston and the pressurizing piston, and transmitting the operating force to the pressurizing piston. Prohibit and allow contact with the pressurizing piston by the advance of the input piston in a state where the volume reduction of the reaction force chamber is allowed, and allow the operation force to be transmitted to the pressurizing piston. The cylinder device according to claim 1 or 2, configured as described above. The volume-based communication mechanism is
A communication path for a volume-based communication mechanism for communicating the reaction force chamber and the reservoir;
An open / close valve provided in the communication passage for the volume-dependent communication mechanism and opened only when the input piston moves forward and the volume of the inter-piston chamber becomes smaller than a set volume. The cylinder device described in 1. The input piston has a cylindrical main body member and a front end which blocks the front end portion of the main body member so as to define an internal chamber in the main body member and can be projected and retracted with respect to the main body member. A member and a spring disposed in the inner chamber and biasing the front end member in a direction in which the front end member protrudes;
An elastic force-based pressurizing mechanism including the spring and capable of pressurizing the reaction force chamber depending on the elastic force is configured, and the front end of the main body member is moved to the pressurizing piston by the advance of the input piston. The operating force is transmitted to the pressurizing piston when it comes into contact with
The on-off valve is provided at a front end member of the input piston, and when the front end member approaches the set distance to the bottom of the bottomed hole, it engages with an engaging portion provided at the bottom of the bottomed hole. Configured to open, and
The cylinder device according to claim 4, wherein the volume-dependent communication mechanism communication path includes the inner chamber of the input piston. The cylinder device is
An annular reaction force chamber having a main body portion and a flange portion formed on the outer periphery of the main body portion, the input chamber being partitioned in front of the main body portion, and the volume of which changes with its own advance and retreat. Is provided with an intermediate piston disposed in the housing in such a manner as to be partitioned in front of the flange portion,
The input piston is adapted to transmit the operating force to the intermediate piston from behind the intermediate piston;
The operating state switching mechanism prohibits the volume reduction of the reaction force chamber, thereby prohibiting the forward movement of the intermediate piston and prohibiting the transmission of the operating force to the pressurizing piston. In a state where the volume reduction of the intermediate piston is allowed, the intermediate piston is allowed to advance in a state where the main body portion of the intermediate piston is in contact with the pressure piston, and the operation force is transmitted to the pressure piston. The cylinder device according to claim 1 or 2, wherein the cylinder device is configured to allow the above. The volume-based communication mechanism is
A communication path for a volume-based communication mechanism for communicating the reaction force chamber and the reservoir;
A reaction force chamber opening / closing valve that is provided in the communication passage for the volume-dependent communication mechanism and opens only when the intermediate piston moves forward and the volume of the reaction force chamber becomes smaller than the set volume. The cylinder device according to claim 6. The intermediate piston is in sliding contact with the inner peripheral surface of the housing via a seal fitted to the outer peripheral surface of the main body portion of the intermediate piston in front of the reaction force chamber,
The intermediate piston has a port that is provided on the inner peripheral surface of the housing at a position facing the front portion of the seal of the intermediate piston in a state where the intermediate piston is not advanced, and to which the communication passage for the volume-dependent communication mechanism is connected,
The reaction chamber open / close valve includes the seal and the port, and the intermediate piston moves forward to a position where the port faces a rear portion of the seal of the intermediate piston, so that the reaction chamber has the port. The cylinder device according to claim 7, which is configured to communicate with the reservoir via The input piston is fitted to the rear end of the intermediate piston such that an internal chamber whose volume changes with relative movement with the intermediate piston is defined.
The cylinder device is
With the relative movement of the input piston and the intermediate piston in the direction in which the volume of the internal chamber decreases, the elastic force is applied to the input piston and the intermediate piston in the direction opposite to the relative movement. The cylinder device according to any one of claims 6 to 9, further comprising a mechanism. The cylinder device is
A spring disposed in the internal chamber and acting on the input piston and the intermediate piston in a direction in which the volume of the internal chamber increases in its own elastic force;
The cylinder device according to claim 9, wherein the elastic force applying mechanism includes the spring. The operating state switching mechanism is
An internal chamber communication state switching mechanism for communicating the internal chamber and the reservoir in the high pressure source pressure dependent pressurizing state and preventing the internal chamber and the reservoir from communicating in the operating force dependent pressurizing state; The cylinder device according to claim 9 or 10, which has the cylinder device.

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