JP6442247B2 - valve - Google Patents

Description

  The present invention relates to a valve.

  Some shock absorbers used for vehicle suspensions include a valve that can vary the damping force. For example, a damping force variable valve disclosed in Patent Document 1 is used as a piston valve that is held by a rod and is movably inserted into a cylinder. This piston valve includes a piston that partitions an extension side chamber and a pressure side chamber formed in a cylinder, a valve disc (disc 18 of Patent Document 1) stacked on the piston, and an extension side chamber formed on the valve disc. A passage (the main passage C) communicating with the pressure side chamber, a valve body (spool 8) stacked on the valve disc to open and close the passage, and a back pressure chamber for biasing the valve body toward the valve disc side, And an electromagnetic pressure control valve for controlling the pressure of the back pressure chamber in accordance with the applied current. Then, by adjusting the current amount to control the valve opening pressure of the electromagnetic pressure control valve, the valve opening pressure of the valve body can be adjusted, and the damping force generated by the buffer can be made variable.

JP 2005-308178 A

  In the valve disc disclosed in Japanese Patent Application Laid-Open No. 2005-308178, the valve seat on which the valve body is separated and attached is provided with a notch for forming an orifice, and the piston speed for moving in the cylinder is low. In the low speed region where the body does not open, the shock absorber can exert a low speed damping force due to the orifice resistance caused by the stamping. Conventionally, in order to reduce the low-speed damping force in the soft mode in which the valve opening pressure of the valve body is minimized, the area of the orifice is increased by increasing the number of stamps or increasing the number of stamps. However, in this case, since the orifice characteristic is prioritized in the low speed region, there is a problem that the low speed damping force does not change even if the pressure in the back pressure chamber is changed, and the damping force variable range is narrowed.

  Accordingly, the present invention has been developed to improve the above-described problems, and an object of the present invention is to provide a valve that can vary the low-speed damping force and increase the damping force variable width. .

It means for solving the above problems, whereas a valve disk for partitioning the chamber and the other chamber, a passage above is formed in the valve disc communicates the hand chamber and the other chamber above is stacked on the valve disc a ring-shaped first valve body for opening and closing the passage Te, the first valve element anti the valve is stacked on the disk side between the outer diameter of the smaller ring than the outer diameter of the first valve body intermediate seat and , the outer diameter is laminated on the counter valve disc side of the intermediate spacer and the second valve body large ring plate than the outer diameter of the intermediate spacer, between the first valve body and the second valve body A gap between the valve bodies formed on the outer periphery of the intermediate spacer, a hole formed in the first valve body to communicate the passage and the gap between the valve bodies, and the second valve body and biasing the Ichiben side and a changing means for changing the amount of opening of the gap between the valve body, said changing means, internal A back pressure chamber for biasing the second valve body to the first valve body side with a force, and having an electromagnetic pressure control valve for controlling the internal pressure of the back pressure chamber. Other means include: a valve disc that partitions one chamber from the other chamber; a passage formed in the valve disc that communicates the one chamber with the other chamber; and a layer that is stacked on the valve disc to define the passage. An annular plate-shaped first valve body that opens and closes, an annular intermediate spacer that is laminated on the side opposite to the valve disc of the first valve body and has an outer diameter smaller than the outer diameter of the first valve body, and the intermediate space An annular plate-like second valve body laminated on the side opposite to the valve disc of the seat and having an outer diameter larger than the outer diameter of the intermediate spacer, and the intermediate between the first valve body and the second valve body A gap between the valve bodies formed on the outer periphery of the spacer, a hole formed in the first valve body to communicate the passage and the gap between the valve bodies, and the second valve body on the first valve body side Changing means for energizing and changing an opening amount between the valve element gaps, the changing means being a second counter element of the second valve element. A spool that contacts the outer periphery of the intermediate spacer on the valve body side, a back pressure chamber that urges the spool toward the first valve body side with internal pressure, and an electromagnetic pressure control that controls the internal pressure of the back pressure chamber And a valve .

  According to the valve of the present invention, it is possible to make the low-speed damping force variable and increase the damping force variable range.

It is the longitudinal cross-sectional view which showed partially the buffer provided with the valve | bulb which concerns on one embodiment of this invention. It is the longitudinal cross-sectional view which expanded and showed the principal part of the valve | bulb which concerns on one embodiment of this invention. It is the figure which expanded and showed a part of FIG. It is the top view which showed the 1st valve body of the valve | bulb which concerns on one embodiment of this invention. It is the figure which expanded and showed other one part of FIG. It is the figure which showed in principle the shock absorber provided with the valve | bulb which concerns on other embodiment of this invention. It is the longitudinal cross-sectional view which expanded and showed the principal part of the valve | bulb which concerns on other embodiment of this invention.

  A valve according to an embodiment of the present invention will be described below with reference to the drawings. The same reference numerals given throughout the several drawings indicate the same or corresponding parts.

  As shown in FIG. 1, the valve according to the present embodiment is used as a piston valve V1 of a shock absorber D, and is a valve disk that partitions an expansion side chamber (one chamber) R1 and a pressure side chamber (other chamber) R2. 1 and a pressure side passage (passage) 1b formed in the valve disc 1 and communicating the extension side chamber R1 and the pressure side chamber R2, and is laminated on the valve disc 1 as shown in FIG. An annular plate-like pressure-side first valve body (first valve body) 2 that opens and closes the pressure-side passage 1b, and the pressure-side first valve body that is laminated on the side opposite to the valve disk of the pressure-side first valve body 2 An annular intermediate spacer 20 smaller than the outer diameter of 2 and an annular plate-shaped pressure side second laminated on the opposite valve disc side of the intermediate spacer 20 and having an outer diameter larger than the outer diameter of the intermediate spacer 20. Valve body (second valve body) 21, pressure side first valve body 2, and pressure A clearance a between the valve bodies formed on the outer periphery of the intermediate spacer 20 with the second valve body 21, and a pressure side passage 1b and a clearance between the valve bodies a formed in the pressure side first valve body 2. And a changing means A for biasing the pressure side second valve body 21 toward the pressure side first valve body 2 to change the opening amount of the inter-valve gap a.

  In the present embodiment, the shock absorber D is used for a vehicle suspension. As shown in FIG. 1, the shock absorber D is a cylinder Dc, a rod Dr that enters and exits the cylinder Dc, and a cylinder Dc that is held by the rod Dr. A piston valve V1 that can move in the axial direction, a free piston (not shown) that slides in contact with the inner peripheral surface of the cylinder Dc on the opposite rod side, and that can move in the axial direction in the cylinder Dc, and FIG. An annular rod guide (not shown) that is fixed to the middle upper end and pivotally supports the rod Dr, a seal (not shown) that is attached to the rod guide and seals the outer periphery of the rod Dr, and FIG. And a bottom cap (not shown) for closing the middle and lower end openings.

  A mounting member (not shown) for interposing the shock absorber D between the vehicle body and the wheel is fixed to the protruding end of the rod Dr protruding from the cylinder Dc and the bottom cap (not shown). When the impact due to the unevenness is input to the wheel, the rod Dr enters and exits the cylinder Dc, and the shock absorber D expands and contracts.

  In the cylinder Dc, an extension side chamber R1 on the side of the rod Dr that is partitioned by the piston valve V1 and filled with hydraulic oil and a pressure side chamber R2 on the side of the piston valve V1 are formed, and the pressure side chamber R2 is formed by a free piston (not shown). And an air chamber (not shown) in which gas is enclosed is formed. When the shock absorber D expands and contracts, the free piston moves in the axial direction in the cylinder Dc to expand and contract the air chamber, and the change in the cylinder volume corresponding to the rod protruding and retracting volume can be compensated in the air chamber.

  In other words, the shock absorber D in the present embodiment is set to a single rod single cylinder type, and can compensate the change in volume in the cylinder corresponding to the volume of the rod and the change in the volume of hydraulic oil due to the temperature change in the air chamber. The configuration of the shock absorber D is not limited to the above, and even if it is set to a double cylinder type having an outer cylinder standing on the outer periphery of the cylinder Dc, it is a double rod type in which the rod Dr stands on both sides of the piston valve V1. It may be set. In addition, the shock absorber D in the present embodiment is a hydraulic shock absorber that uses hydraulic oil as a fluid for generating a damping force. However, it is assumed that a liquid other than hydraulic oil or gas is used as the fluid. Also good.

  In this embodiment, the rod Dr has a piston holding member 3 to which the valve disk 1 of the piston valve V1 is attached on the outer periphery, and one end connected to the piston holding member 3 and accommodates the electromagnetic pressure control valve 4 together with the piston holding member 3. And a rod member 31 having one end connected to the solenoid valve housing tube 30 and the other end projecting outward from the upper end of the cylinder Dc. .

  The piston holding member 3 is provided on a holding shaft 3a for holding the valve disc 1 on the outer periphery, an annular flange 3b provided on the outer periphery of the upper end in FIG. 1 of the holding shaft 3a, and an outer periphery of the upper end of the flange 3b in FIG. And a large-diameter cylindrical socket 3c. Further, the piston holding member 3 is provided with a vertical hole 3d that opens from the tip of the holding shaft 3a and extends in the axial direction and communicates with the socket 3c, and an annular ring that is provided at the lower end of the flange 3b in FIG. 1 so as to surround the holding shaft 3a. A groove 3e, a port 3f that communicates the annular groove 3e with the socket 3c, a horizontal hole 3g that communicates the annular groove 3e with the longitudinal hole 3d, and an extended side that opens from the outer periphery of the holding shaft 3a and communicates with the longitudinal hole 3d An extension side pilot orifice Pe as a resistance element, a pressure side pilot orifice Pp as a pressure side resistance element, and a groove 3h formed at the upper end of the flange 3b and leading to the vertical hole 3d are formed.

  A cylindrical separator 32 is inserted into the vertical hole 3d of the holding shaft 3a, and an extension side pilot orifice Pe and a pressure side pilot orifice Pp are inserted into the vertical hole 3d by an annular groove 32a formed on the outer periphery of the separator 32. Is formed. Further, an annular valve seat 32b surrounding the opening of the lower end is provided at the lower end of the separator 32 in FIG. The vertical hole 3d allows the pressure side chamber R2 to communicate with the socket 3c through the separator 32, but the expansion side pilot orifice Pe and the pressure side pilot orifice Pp are connected to the pressure side chamber R2 and the socket through the vertical hole 3d by the separator 32. It does not lead to 3c. Further, the lateral hole 3g also communicates with the communication passage 33, and the lateral hole 3g is also prevented from communicating with the pressure side chamber R2 and the socket 3c through the interior of the longitudinal hole 3d by the separator 32.

  The above-mentioned extension side resistance element and pressure side resistance element only have to give resistance to the flow of hydraulic fluid passing therethrough, so that not only the orifice but also another restriction such as a choke passage may be used, or a leaf valve Or a valve that provides resistance, such as a poppet valve.

  In the socket 3c, an annular recess 3i is formed on the outer periphery of the upper end in FIG. 1, and a through hole 3j communicating from the recess 3i into the socket 3c is formed. An annular plate 34a is attached to the recess 3i, and the annular plate 34a is urged by a spring member 34b from above in FIG. 1 to close the through hole 3j.

  The solenoid valve housing cylinder 30 has a top tubular housing cylinder portion 30a and a tubular connecting portion having an outer diameter smaller than that of the housing cylinder portion 30a and extending upward from the top of the housing tube portion 30a in FIG. 30 b and a through hole 30 c that opens from the side of the housing cylinder 30 a and communicates with the inside. The piston holding member 3 is integrated with the solenoid valve housing cylinder 30 by screwing the socket 3c of the piston holding member 3 to the inner periphery of the housing cylinder portion 30a of the solenoid valve housing cylinder 30. The housing tube 30 and the piston holding member 3 form a housing portion L in which the electromagnetic pressure control valve 4 is housed in the housing tube portion 30a, and a part of an adjustment passage Pc described later in detail is provided in the housing portion L. . The accommodating portion L is connected to the communication path 33 by the port 3f, the annular groove 3e, and the lateral hole 3g, and the port 3f, the annular groove 3e, and the lateral hole 3g form a part of the adjustment passage Pc. ing. In addition, since the accommodating part L should just be connected to the communicating path 33, it does not employ | adopt the port 3f, the annular groove 3e, and the horizontal hole 3g, but the path | route which communicates with the accommodating part L directly to the communicating path 33 is used. Although it may be provided, the use of the port 3f, the annular groove 3e, and the lateral hole 3g has an advantage that the processing of the passage communicating the accommodating portion L and the communication passage 33 is facilitated.

  As described above, when the piston holding member 3 is integrated with the solenoid valve housing cylinder 30, the through hole 30c faces the recess 3i and cooperates with the through hole 3j to communicate the housing portion L with the expansion side chamber R1. A check valve 34 is formed by the annular plate 34a and the spring member 34b. The check valve 34 allows only the flow of hydraulic oil from the accommodating portion L toward the extending side chamber R1. The through hole 30c, the recess 3i, the through hole 3j, and the check valve 34 allow the downstream of the adjustment passage Pc to communicate with the extension side chamber R1 and allow only the flow of hydraulic oil from the adjustment passage Pc toward the extension side chamber R1. A pressure side discharge passage Ep is formed.

  Further, a check valve 35 that is attached to and detached from an annular valve seat 32b provided at the lower end in FIG. 1 of the separator 32 is provided in the vertical hole 3d of the piston holding member 3, and the check valve 35 includes a pressure side chamber. While preventing the flow of the hydraulic oil which goes to the accommodating part L from the R2 side, only the flow of the hydraulic oil which goes to the compression side chamber R2 from the accommodating part L is permitted. An extension side discharge passage Ee that communicates the downstream side of the adjustment passage Pc to the pressure side chamber R2 and allows only the flow of hydraulic oil from the adjustment passage Pc to the pressure side chamber R2 is formed inside the separator 32 in the vertical hole 3d. Is done.

  The rod member 31 has a cylindrical shape, and the inner periphery at the lower end in FIG. 1 has an enlarged diameter. The insertion of the connecting portion 30b of the solenoid valve housing cylinder 30 is allowed, and the connecting portion 30b is screwed. Can be done. In this way, the rod Dr is formed by integrating the rod member 31, the electromagnetic valve housing cylinder 30, and the piston holding member 3.

  A harness H for supplying power to a solenoid Sol described later is inserted into the rod member 31 and the connecting portion 30b of the solenoid valve housing cylinder 30, and the upper end of the harness H is not shown, but from the upper end of the rod member 31. It extends outward and is connected to a power source.

  As shown in FIG. 3, the piston valve V <b> 1 held by the rod Dr includes a valve disc 1 held on the outer periphery of the holding shaft 3 a of the piston holding member 3, and a pressure side first assembled to the upper side of the valve disc 1 in FIG. 3. One valve body 2, a pressure side second valve body 21, a pressure side spool 23, a pressure side chamber 24 forming a pressure side back pressure chamber Cp, an extension side valve body 5 assembled on the lower side of the valve disk 1 in FIG. 51 and an extension side chamber 52 that forms the extension side back pressure chamber Ce, and an electromagnetic pressure control valve 4 that is housed in the housing portion L shown in FIG. 1 and controls the pressures of the pressure side back pressure chamber Cp and the extension side back pressure chamber Ce. And a fail valve 6 that bypasses the electromagnetic pressure control valve 4.

  As shown in FIG. 3, the valve disk 1 is a piston formed by superimposing the vertically divided disks 10 and 11 in this embodiment, and is provided on the outer periphery of the lower disk 11. By sliding a ring (not shown) in contact with the inner peripheral surface of the cylinder Dc, the cylinder Dc can be smoothly slid in the axial direction. The valve disk 1 is formed with an extension side passage 1a and a pressure side passage 1b that connect the extension side chamber R1 and the pressure side chamber R2. In this way, by forming the valve disc 1 with the discs 10 and 11 divided into upper and lower parts, it is possible to form the elongated side passage 1a and the compression side passage 1b having complicated shapes without drilling. The valve disc 1 can be manufactured inexpensively and easily. An annular valve seat 1d surrounding the outer periphery of the pressure side passage 1b is provided at the upper end of the upper disk 10, and an annular valve seat surrounding the outer periphery of the extension side passage 1a is provided at the lower end of the lower disk 11. 1c is formed.

  The extension side valve element 5 is formed in an annular plate shape and has a center hole for allowing the holding shaft 3a of the piston holding member 3 to be inserted, and is laminated on the lower end of the valve disc 1 in FIG. . The inner circumference of the extension side valve element 5 is sandwiched between the valve disc 1 and the extension side chamber 52 and is fixed to the holding shaft 3 a of the piston holding member 3. A spacer 50 is interposed between the extension side valve element 5 and the extension side chamber 52. The spacer 50 is formed in an annular shape and is a center for allowing insertion of the holding shaft 3a. While having a hole, the outer diameter is set smaller than the outer diameter of the expansion side valve body 5.

  The extension-side valve element 5 is seated on the valve seat 1c to close the extension-side passage 1a, and is allowed to bend on the outer peripheral side with respect to the portion supported by the spacer 50. The passage 1a can be opened.

  The extension side chamber 52 includes a cylindrical mounting portion 52a fitted to the outer periphery of the holding shaft 3a of the piston holding member 3, a flange portion 52b provided on the outer periphery of the lower end in FIG. 3 of the mounting portion 52a, and a flange portion 52b. And a sliding contact cylinder 52c extending from the outer periphery toward the valve disc 1 side.

  An extension side spool 51 is accommodated in the sliding contact cylinder 52c. The extension-side spool 51 is in sliding contact with the inner periphery of the sliding contact cylinder 52c, and can move in the axial direction within the sliding contact cylinder 52c. The extension side spool 51 includes an annular spool body 51a and an annular protrusion 51b that rises from the inner periphery of the upper end of the spool body 51a in FIG. 3, and the annular protrusion 51b is the back surface of the extension side valve body 5 in FIG. It can come into contact with the lower surface.

  Then, when the extension side spool 51 is assembled to the extension side chamber 52 and the extension side chamber 52 is assembled to the holding shaft 3a in this way, the extension side spine is located on the lower side in FIG. A pressure chamber Ce is formed. Although the inner diameter of the spool body 51a is larger than the outer diameter of the mounting portion 52a, the inner diameter of the spool body 51a is set to a diameter that is in sliding contact with the outer periphery of the mounting portion 52a so It is also possible to make it.

  In addition, the mounting portion 52a of the extension side chamber 52 is provided with an annular groove 52d on the inner periphery thereof, and a notch 52e leading from the outer periphery of the attachment portion 52a to the annular groove 52d. When assembled to the holding shaft 3a, the annular groove 52d is opposed to the pressure side pilot orifice Pp provided in the holding shaft 3a, so that the expansion side back pressure chamber Ce communicates with the pressure side pilot orifice Pp.

  Furthermore, the expansion side chamber 52 is provided with a pressure side pressure introduction passage Ip that opens from the outer periphery of the flange portion 52b, and communicates the compression side chamber R2 into the expansion side back pressure chamber Ce. An annular plate 54 is laminated on the upper end of the flange portion 52 b of the extension side chamber 52 in FIG. 3, and the annular plate is provided by a spring member 53 interposed between the annular plate 54 and the spool body 51 a of the extension side spool 51. 54 is pressed against the flange portion 52b to close the pressure side pressure introduction passage Ip. Note that the pressure-side pressure introduction passage Ip is considered so as not to cause resistance to the flow of the working oil that passes therethrough.

  The annular plate 54, together with the spring member 53, constitutes a pressure-side check valve Tp. When the shock absorber D is compressed, the pressure-side chamber R2 is compressed and the pressure is increased, and the pressure is increased by the pressure to separate from the flange portion 52b. Then, the pressure-side pressure introduction passage Ip is opened, and when the shock absorber D is operated so that the pressure in the extension-side back pressure chamber Ce becomes higher than the pressure-side chamber R2, the pressure-side pressure introduction passage Ip is closed by being pressed against the flange portion 52b. Only the flow of hydraulic oil from the pressure side chamber R2 is allowed. That is, the pressure-side check valve Tp sets the pressure-side pressure introduction passage Ip as a one-way passage that allows only the flow of hydraulic oil from the pressure-side chamber R2 toward the expansion-side back pressure chamber Ce.

  The spring member 53 plays a role of pressing the annular plate 54 against the flange portion 52 b, forms the annular plate 54 and the pressure side check valve Tp, and also functions to bias the extension side spool 51 toward the extension side valve body 5. Is also responsible. By energizing the extension side spool 51 with the spring member 53, the extension side valve body 5 is bent and the extension side spool 51 is pushed downward in FIG. Even if the deflection of the valve body 5 is eliminated, it is urged by the spring member 53, so that the expansion side spool 51 follows the expansion side valve body 5 and quickly returns to its original position (position shown in FIGS. 1 and 3). You can go back to Although it is possible to urge the extension side spool 51 with a separate spring member, the compression side check valve Tp and the spring member 53 can be shared, and the number of parts can be reduced and the structure can be simplified. There is. The outer diameter of the spool body 51a in the extension side spool 51 is formed larger than the inner diameter of the annular protrusion 51b, and the annular protrusion 51b comes into contact with the extension side valve body 5, and the extension side The spool 51 is urged toward the expansion valve body 5 by the pressure in the expansion side back pressure chamber Ce.

  The pressure side first valve body 2 and the pressure side second valve body 21 stacked above the valve disk 1 are formed in an annular plate shape, like the extension side valve body 5, and are inserted into the holding shaft 3 a of the piston holding member 3. 3 and is laminated so as to overlap the upper end of the valve disk 1 in FIG. The inner circumferences of the pressure side first valve body 2 and the pressure side second valve body 21 are sandwiched between the valve disk 1 and the pressure side chamber 24 and are fixed to the holding shaft 3 a of the piston holding member 3. An intermediate spacer 20 is interposed between the pressure side first valve body 2 and the pressure side second valve body 21, and a spacer 22 is interposed between the pressure side second valve body 21 and the pressure side chamber 24. It is intervened. The intermediate spacer 20 and the spacer 22 are both formed in an annular shape and have a center hole for allowing the holding shaft 3a to pass therethrough. The outer diameters of the intermediate spacer 20 and the spacer 22 are the pressure side first valve body 2 and the pressure side second valve body. 2 is set to be smaller than the outer diameter of 21, and as shown in FIG. 2, a gap between the pressure side first valve body 2 and the pressure side second valve body 21 is referred to as an inter-valve gap a on the outer periphery of the intermediate spacer 20. Is forming.

  The pressure side first valve body 2 is seated on the valve seat 1d to close the pressure side passage 1b, and is allowed to bend upward in FIG. The pressure side passage 1b is opened by the bending. As shown in FIG. 4, the pressure side first valve body 2 is formed with a notch 2b for forming an orifice on the outer periphery, and the pressure side first valve body 2 is located on the inner peripheral side of the notch 2b. A hole 2a is formed through which the pressure side passage 1b communicates with the inter-valve gap a. The number and shape of the holes 2a and notches 2b can be changed as appropriate. Even if a notch or groove is formed in the valve seat 1d instead of the notch 2b, a choke is formed instead of the orifice. You may do that.

  On the other hand, the pressure-side second valve body 21 is allowed to bend in the upper side in FIGS. Side deflection in FIGS. 2 and 3 is allowed.

  2 and 3, in the state where the pressure side first valve body 2 and the pressure side second valve body 21 are not bent, the inter-valve gap a opens to the expansion side chamber R1 to form an orifice, and its opening area Is a value obtained by multiplying the axial length (thickness) of the intermediate spacer 20 by the circumference of a circle having the outer diameter of the compression-side second valve body 21 as a diameter. When the pressure side first valve body 2 and the pressure side second valve body 21 are bent and approach each other, the opening area of the inter-valve gap a is reduced and the opening amount is reduced. Further, when the pressure side first valve body 2 and the pressure side second valve body 21 come into contact with each other, the opening area becomes substantially zero, and the communication between the inter-valve gap a and the extension side chamber R1 is blocked.

  As shown in FIG. 3, the compression side chamber 24 includes a cylindrical mounting portion 24a fitted to the outer periphery of the holding shaft 3a of the piston holding member 3, and a flange portion 24b provided on the outer periphery of the mounting portion 24a at the upper end in FIG. And a slidable contact cylinder 24c extending from the outer periphery of the flange portion 24b toward the valve disc 1 side.

  A pressure side spool 23 is accommodated in the sliding contact cylinder 24c. The pressure side spool 23 has an outer periphery in sliding contact with an inner periphery of the sliding contact cylinder 24c, and can move in the axial direction within the sliding contact cylinder 24c. The pressure-side spool 23 includes an annular spool body 23a and an annular protrusion 23b that rises from the lower end of the spool body 23a in FIG. 3, and the annular protrusion 23b is on the upper surface in FIG. It can come into contact.

  When the pressure side spool 23 is assembled to the pressure side chamber 24 and the pressure side chamber 24 is assembled to the holding shaft 3a as described above, the pressure side back pressure chamber Cp is located on the upper side in FIG. Is formed. The inner diameter of the spool body 23a is larger than the outer diameter of the mounting portion 24a, but is set to a diameter that is in sliding contact with the outer periphery of the mounting portion 24a so that the compression-side back pressure chamber Cp is sealed by the compression-side spool 23. It is also possible.

  The mounting portion 24a of the pressure side chamber 24 is provided with an annular groove 24d on the inner periphery thereof, and a notch 24e leading from the outer periphery of the mounting portion 24a to the annular groove 24d. When assembled to 3a, the annular groove 24d faces the expansion side pilot orifice Pe provided in the holding shaft 3a, and the compression side back pressure chamber Cp communicates with the expansion side pilot orifice Pe. Thus, the compression side back pressure chamber Cp communicates with the expansion side back pressure chamber Ce through the communication passage 33 formed in the vertical hole 3d of the holding shaft 3a and the compression side pilot orifice Pp by communicating with the expansion side pilot orifice Pe. Is done.

  Furthermore, the compression side chamber 24 is provided with an expansion side pressure introduction passage Ie that opens from the outer periphery of the flange portion 24b, and communicates the expansion side chamber R1 into the compression side back pressure chamber Cp. An annular plate 26 is laminated at the lower end in FIG. 3 of the flange portion 24 b of the compression side chamber 24, and the annular plate 26 is formed by a spring member 25 interposed between the annular plate 26 and the spool body 23 a of the compression side spool 23. The extension side pressure introduction passage Ie is closed by being pressed against the flange portion 24b. Note that the extension side pressure introduction passage Ie is designed so as not to cause resistance to the flow of the working oil passing therethrough.

  The annular plate 26, together with the spring member 25, constitutes the extension side check valve Te. When the buffer D is extended, when the extension side chamber R1 is compressed and the pressure is increased, the annular plate 26 is pressed by the pressure and separated from the flange portion 24b. The extension side pressure introduction passage Ie is opened, and the compression side back pressure chamber Cp is pressed against the flange portion 24b during the compression operation of the shock absorber D in which the pressure in the extension side chamber R1 is higher than the extension side chamber R1, thereby closing the extension side pressure introduction passage Ie. Only the flow of hydraulic oil from the extension side chamber R1 is allowed. That is, the expansion side check valve Te sets the expansion side pressure introduction passage Ie as a one-way passage that allows only the flow of hydraulic oil from the expansion side chamber R1 to the compression side back pressure chamber Cp.

  Here, as described above, the communication passage 33 communicates with the inside of the housing portion L through the annular groove 3e, the port 3f, and the lateral hole 3g provided in the piston holding member 3. Therefore, the extension side back pressure chamber Ce and the pressure side back pressure chamber Cp are not only communicated with each other via the extension side pilot orifice Pe, the pressure side pilot orifice Pp and the communication passage 33, but also via the extension side pressure introduction passage Ie. The expansion side chamber R1 communicates with the compression side chamber R2 via the pressure side pressure introduction passage Ip, and further communicates with the accommodating portion L through the annular groove 3e, the port 3f and the lateral hole 3g.

  Returning, the spring member 25 plays a role of pressing the annular plate 26 against the flange portion 24 b, forms the annular plate 26 and the extension-side check valve Te, and directs the pressure-side spool 23 toward the pressure-side second valve body 21. It also has a role to support. When the pressure side spool 23 is biased by the spring member 25, the pressure side second valve body 21 is bent and the pressure side spool 23 is pushed upward in FIG. Even if the bending of the valve body 21 is eliminated, the pressure side spool 23 follows the pressure side second valve body 21 quickly because it is biased by the spring member 25 (the position shown in FIGS. 1 to 3). You can go back to Although it is possible to urge the compression side spool 23 with a separate spring member, the extension side check valve Te and the spring member 25 can be used in common, and the number of parts can be reduced and the structure can be simplified. There is. The outer diameter of the spool body 23a in the pressure-side spool 23 is set to be larger than the inner diameter of the annular protrusion 23b, and the annular protrusion 23b comes into contact with the pressure-side second valve body 21. 23 is urged toward the pressure side second valve body 21 by the pressure of the pressure side back pressure chamber Cp. Further, the inner diameter of the annular protrusion 23b is set larger than the outer diameter of the intermediate spacer 20, and the pressure side spool 23 has an outer periphery that is closer to the first valve body 2 side than the intermediate spacer 20 of the pressure side second valve body 21. That is, it is biased toward the valve disc 1 side.

  The extension side spool 51 receives the pressure of the extension side back pressure chamber Ce and urges the extension side valve body 5 toward the valve disk 1. However, the extension side spool 51 reduces the pressure of the extension side back pressure chamber Ce of the extension side spool 51. The pressure receiving area is a difference between the area of a circle whose diameter is the outer diameter of the spool body 51a of the expansion side spool 51 and the area of a circle whose diameter is the inner diameter of the annular protrusion 51b. Similarly, the pressure side spool 23 receives the pressure of the pressure side back pressure chamber Cp and urges the pressure side second valve body 21 toward the pressure side first valve body 2, but the pressure side spool 23 has a pressure in the pressure side back pressure chamber Cp. The pressure receiving area that receives the pressure is the difference between the area of a circle whose diameter is the outer diameter of the spool body 23a of the pressure side spool 23 and the area of the circle whose diameter is the inner diameter of the annular protrusion 23b. In the case of the shock absorber D of this embodiment, the pressure receiving area of the expansion side spool 51 is larger than the pressure receiving area of the compression side spool 23.

  Since the annular protrusion 51b of the expansion side spool 51 abuts on the back surface of the expansion side valve body 5 and is supported by the spacer 50, the pressure of the expansion side back pressure chamber Ce is directly applied to the expansion side valve body 5. The acting pressure receiving area is an area obtained by subtracting the area of the circle whose diameter is the outer diameter of the spacer 50 from the area of the circle whose diameter is the inner diameter of the annular protrusion 51b. Therefore, the pressure of the extension-side back pressure chamber Ce is multiplied by the area obtained by subtracting the area of the circle having the outer diameter of the spacer 50 as the diameter from the area of the circle having the outer diameter of the spool body 51a of the extension-side spool 51 as a diameter. Using the force as the extension side load, the extension side valve element 5 is biased toward the valve disc 1 by the extension side load.

  On the other hand, the annular protrusion 23b of the pressure side spool 23 abuts on the back surface of the pressure side second valve body 21 and is supported by the spacer 22. Therefore, the pressure of the pressure side back pressure chamber Cp is directly applied to the pressure side second valve body 21. The pressure receiving area that acts in an automatic manner is an area obtained by subtracting the area of a circle having the diameter of the outer diameter of the spacer 22 from the area of a circle having the diameter of the annular protrusion 23b as the diameter. Therefore, the force obtained by multiplying the area obtained by subtracting the area of the circle whose outer diameter is the outer diameter of the spacer 22 from the area of the circle whose diameter is the outer diameter of the spool body 23a of the pressure-side spool 23 by the pressure of the pressure-side back pressure chamber Cp. As the pressure side load, the pressure side second valve body 21 is urged toward the pressure side first valve body 2 by the pressure side load.

  Further, the pressure side second valve body 21 is supported by the intermediate spacer 20 and the outer periphery thereof receives a pressure side load and bends to the pressure side first valve body 2 side, thereby making the opening amount of the inter-valve gap a variable. At the same time, when coming into contact with the pressure-side first valve body 2, a pressure-side load is applied to the pressure-side first valve body 2 toward the valve disc 1.

  According to the above configuration, when the pressure in the expansion side back pressure chamber Ce and the pressure in the compression side back pressure chamber Cp are equal, the expansion side load that is the load that the expansion side valve body 5 receives from the expansion side back pressure chamber Ce is The pressure side first valve body 2 and the pressure side second valve body 21 are set to be larger than the pressure side load that is a load received from the pressure side back pressure chamber Cp. When the extension side back pressure chamber Ce is closed by the extension side spool 51 and the pressure in the extension side back pressure chamber Ce is not directly applied to the extension side valve body 5, the extension side load is increased by the extension side spool 51. The pressure side is also determined by only the pressure receiving area that receives the pressure of the side back pressure chamber Ce. Similarly, the pressure side back pressure chamber Cp is closed by the pressure side spool 23 and the pressure of the pressure side back pressure chamber Cp is directly applied to the pressure side second valve body 21. When not acting, the pressure side load is determined only by the pressure receiving area that receives the pressure of the pressure side back pressure chamber Cp of the pressure side spool 23. When the pressure in the extension side back pressure chamber Ce and the pressure in the compression side back pressure chamber Cp are equal, the extension side load received by the extension side valve body 5 from the extension side back pressure chamber Ce is the compression side first valve body 2 or Since the pressure side second valve body 21 only needs to be set to be larger than the pressure side load received from the pressure side back pressure chamber Cp, pressure is directly applied to the expansion side valve body 5 and the pressure side second valve body 21 from the back pressure chamber. If not, it is sufficient to make the pressure receiving area of the expansion side spool 51 larger than the pressure receiving area of the compression side spool 23. The pressure in the expansion side back pressure chamber Ce is directly applied to the expansion side valve body 5, but the pressure in the compression side back pressure chamber Cp may not be directly applied to the compression side second valve body 21, or vice versa. May be. In the present invention, since the expansion side spool 51 and the compression side spool 23 are used, the pressure receiving area for applying the pressure of the expansion side back pressure chamber Ce to the expansion side valve body 5 substantially is the pressure receiving area of only the expansion side valve body 5. Since the pressure receiving area difference between the compression side spool 23 and the expansion side spool 51 can also be set large, there can be a large difference between the expansion side load and the compression side load. A very high degree of freedom can be given to the set width of the load.

  Further, as shown in FIG. 1, the extension side back pressure chamber Ce and the pressure side back pressure chamber Cp are upstream, the extension side discharge passage Ee and the pressure side discharge passage Ep are downstream, and these are communicated with each other through an adjustment passage Pc. The pressure control valve 4 is provided in the middle of the adjustment passage Pc and can control the pressures of the upstream extension side back pressure chamber Ce and the pressure side back pressure chamber Cp. Therefore, when the pressure in the extension side back pressure chamber Ce and the pressure side back pressure chamber Cp is controlled by the electromagnetic pressure control valve 4, the extension side load is made larger than the compression side load. Even when it is desired to increase the damping force on the extension side, the maximum pressure to be controlled by the electromagnetic pressure control valve 4 can be reduced.

  In the present embodiment, the expansion side spool 51 is not slidably contacted with the outer periphery of the mounting portion 52 a of the expansion side chamber 52, and the pressure of the expansion side back pressure chamber Ce is the back surface of the expansion side valve element 5. Since the extension side valve element 5 also acts on the inner side of the contact portion of the annular protrusion 51b to urge the extension side valve element 5, the extension side valve element is set by the pressure of the extension side back pressure chamber Ce when setting the extension side load. It is good to set taking into account the load that directly energizes 5. The inner circumference of the pressure side spool 23 is not in sliding contact with the outer periphery of the mounting portion 24a of the pressure side chamber 24, and the pressure side back pressure chamber Cp is on the back side of the pressure side second valve body 21 and the contact portion of the annular protrusion 23b. Since the pressure side second valve body 21 is also urged inside the pressure side, the load for directly urging the pressure side second valve body 21 with the pressure of the pressure side back pressure chamber Cp is taken into account when setting the pressure side load. To set.

  Further, the extension side valve body 5, the pressure side first valve body 2 and the pressure side second valve body 21 are all fixed to the rod Dr at the inner periphery. The whole may be separated from the valve disk 1.

In the present embodiment, the electromagnetic pressure control valve 4 is set to close the adjustment passage Pc when not energized and to perform pressure control when energization, and bypass the electromagnetic pressure control valve 4 in the middle of the adjustment passage Pc. A fail valve 6 is provided.

  As shown in FIG. 5, the electromagnetic pressure control valve 4 includes a valve seat member 40 including a valve housing cylinder 40a and a control valve valve seat 40d, an electromagnetic valve valve body 41 that is attached to and detached from the control valve valve seat 40d, The solenoid valve body 41 is provided with a solenoid Sol that applies thrust to the valve body 41 and drives it in the axial direction.

  The valve seat member 40 is fitted into the socket 3c of the piston holding member 3, and the valve housing cylinder 40a is inserted into the inner periphery of the annular valve housing 60 stacked on the upper end of the flange 3b in FIG. And is accommodated in the accommodating portion L while being positioned in the radial direction.

  The valve housing 60 is annular and has an annular window 60a provided at the upper end in FIG. 5, a port 60b that opens from the annular window 60a and communicates with the lower end in FIG. 5, and a port that opens from the inner periphery of the upper end in FIG. A notch groove 60c communicating with 60b, a groove 60d provided on the outer periphery along the axial direction, and an annular fail valve seat 60e surrounding the outer periphery of the annular window 60a are provided.

  When the valve housing 60 is inserted into the socket 3c and stacked on the upper end of the flange 3b in FIG. 5, the port 60b faces the opening facing the upper end of the flange 3b of the port 3f, and the port 60b and the cutout groove 60c are connected to the port 3f. Further, the groove 60d is communicated with the groove 3h provided in the flange 3b so as to face the groove 3h.

  Therefore, the port 60b and the cutout groove 60c are communicated with the communication path 33 through the annular groove 3e, the port 3f and the lateral hole 3g shown in FIGS. 1 and 3, and further, the communication path 33, the pressure side pilot orifice Pp and the expansion side pilot. The expansion side back pressure chamber Ce and the pressure side back pressure chamber Cp communicate with each other through the orifice Pe. Further, as shown in FIG. 5, the groove 60d communicates with the pressure side chamber R2 through the groove 3h in the separator 32 and through the expansion side discharge passage Ee formed by the check valve 35, as well as through holes 30c, recesses 3i, It communicates with the extension side chamber R1 through the pressure side discharge passage Ep formed by the through hole 3j and the check valve 34.

  In the valve housing 60, the valve accommodating cylinder 40a in the cylindrical valve seat member 40 is accommodated. The valve seat member 40 has a bottomed cylindrical shape and has a valve accommodating cylinder 40a provided with a flange 40b on the outer periphery of the upper end in FIG. 5, a through hole 40c that opens from the side of the valve accommodating cylinder 40a and communicates with the inside, An annular control valve seat 40d that protrudes in the axial direction is provided at the upper end in FIG. 5 of the valve accommodating cylinder 40a.

  Further, a fail valve valve body 61, which is an annular leaf valve, is mounted on the outer periphery of the valve housing cylinder 40a of the valve seat member 40. The valve housing cylinder 40a is inserted into the valve housing 60, and the valve seat member 40 is inserted. When assembled to the valve housing 60, the fail valve body 61 is fixed by being sandwiched between the flange 40b of the valve seat member 40 and the inner periphery of the upper end of the valve housing 60 in FIG. The annular fail valve seat 60e provided in the seat is seated in an initial deflection state, and the annular window 60a is closed. The fail valve body 61 bends when the pressure acting in the annular window 60a through the port 60b reaches the valve opening pressure, opens the annular window 60a, and connects the port 60b to the expansion side discharge passage Ee and the pressure side discharge passage Ep. The fail valve body 61 and the fail valve valve seat 60e form the fail valve 6 in communication.

  When the valve housing cylinder 40a is inserted into the valve housing 60 and the valve seat member 40 is assembled to the valve housing 60, the notch groove 60c provided in the valve housing 60 is opposed to the through hole 40c provided in the valve housing cylinder 40a. The extension-side back pressure chamber Ce and the compression-side back pressure chamber Cp are communicated with each other in the valve housing cylinder 40a through the port 60b.

  A valve fixing member 36 that is annular and contacts the upper end of the flange 40b in FIG. 5 is stacked above the valve seat member 40 in FIG. A solenoid Sol accommodated in the valve accommodating cylinder 30 is arranged, and when the piston holding member 3 is screwed and integrated with the electromagnetic valve accommodating cylinder 30, the valve housing 60, the fail valve valve body 61, the valve seat The member 40, the valve fixing member 36 and the solenoid Sol are sandwiched and fixed between the electromagnetic valve housing cylinder 30 and the piston holding member 3. It should be noted that the valve fixing member 36 has a notch groove 36 a so that the space on the inner peripheral side of the valve fixing member 36 can communicate with the space on the outer peripheral side of the valve seat member 40 even when abutting against the flange 40 b of the valve seat member 40. Is provided. This communication may be performed not by the notch groove 36a but by a hole such as a port.

  As shown in FIG. 1, the solenoid Sol includes a top-end cylindrical mold stator 43 in which a winding 42 and a harness H energizing the winding 42 are integrated with a mold resin, and a top-end cylindrical stator stator. A first fixed iron core 44 fitted to the inner periphery of 43, an annular second fixed iron core 45 laminated on the lower end in FIG. 1 of the mold stator 43, a first fixed iron core 44, and a second fixed iron core 45 A filler ring 46 interposed therebetween to form a magnetic gap, a cylindrical movable iron core 47 disposed on the inner peripheral side of the first fixed iron core 44 and the second fixed iron core 45 so as to be axially movable, 1 and a shaft 48 fixed to the inner periphery of the movable iron core 47. By energizing the winding 42, the movable iron core 47 is sucked to give the shaft 48 thrust downward in FIG. Can be done.

  Further, as shown in FIG. 5, a solenoid valve body 41 is slidably inserted into the valve seat member 40. Specifically, the solenoid valve body 41 includes a small diameter portion 41a that is slidably inserted into the valve housing cylinder 40a of the valve seat member 40, and a counter valve seat member side that is the upper side of the small diameter portion 41a in FIG. A large-diameter portion 41b that is provided and is not inserted into the valve housing cylinder 40a, an annular recess 41c provided between the small-diameter portion 41a and the large-diameter portion 41b, and an outer periphery of the large-diameter portion 41b on the side opposite to the valve seat member A flange-shaped spring receiving portion 41d provided in the communication valve 41, a communication path 41e penetrating from the front end to the rear end of the solenoid valve valve body 41, and an orifice 41f provided in the middle of the communication path 41e.

  Further, in the electromagnetic valve body 41, as described above, the large diameter portion 41b having the outer diameter on the side opposite to the valve seat member larger than the small diameter portion 41a is formed with the recess 41c as a boundary. The large-diameter portion 41b is provided with a seating portion 41g facing the control valve valve seat 40d at the lower end in FIG. 5, and the seating portion 41g is controlled by the solenoid valve body 41 moving in the axial direction with respect to the valve seat member 40. The valve seat 40d is separated from the seat. That is, the electromagnetic pressure control valve 4 is configured by including the electromagnetic valve body 41 and the valve seat member 40, and the electromagnetic pressure control valve 4 is closed when the seating portion 41g is seated on the control valve valve seat 40d. It has become.

  A coil spring 37 for biasing the electromagnetic valve valve body 41 in a direction away from the valve seat member 40 is interposed between the flange 40b of the valve seat member 40 and the spring receiving portion 41d. A solenoid Sol that exerts a thrust force against the urging force of the spring 37 is provided. Therefore, the solenoid valve body 41 is always urged in the direction away from the valve seat member 40 by the coil spring 37, and if the thrust against the coil spring 37 from the solenoid Sol does not act, the valve seat member 40 It is positioned at the most distant position. In this case, the electromagnetic valve valve body 41 is urged away from the valve seat member 40 by using the coil spring 37, but an urging force can be exerted in addition to the coil spring 37. An elastic body that can be used can be used.

  When the solenoid valve body 41 is farthest from the valve seat member 40, the small diameter portion 41a is opposed to the through hole 40c to close the through hole 40c, and the solenoid Sol is energized to the valve seat member 40. When a predetermined amount is moved from the position farthest away to the valve seat member side, the concave portion 41c is always opposed to the through hole 40c and the through hole 40c is opened.

  When the solenoid valve body 41 opens the through hole 40c and the seating portion 41g is separated from the control valve valve seat 40d, the through hole 40c passes through the recess 41c of the solenoid valve valve body 41 and the notch groove 36a provided in the valve fixing member 36. It communicates with the extension side discharge passage Ee and the pressure side discharge passage Ep, and controls the force for biasing the solenoid valve body 41 toward the valve seat member 40 by adjusting the thrust of the solenoid Sol. If the action of the pressure upstream of the electromagnetic pressure control valve 4 and the force that pushes up the electromagnetic valve body 41 by the coil spring 37 in FIG. 5 exceeds the force that pushes down the electromagnetic valve body 41 by the solenoid Sol, the electromagnetic pressure control valve 4 can be opened to control the pressure on the upstream side of the electromagnetic pressure control valve 4 according to the thrust of the solenoid Sol. Since the upstream side of the electromagnetic pressure control valve 4 communicates with the expansion side back pressure chamber Ce and the pressure side back pressure chamber Cp through the adjustment passage Pc, the electromagnetic pressure control valve 4 allows the expansion side back pressure chamber Ce or the pressure side. The pressure in the back pressure chamber Cp can be controlled.

  In the present embodiment, the electromagnetic pressure control valve 4 includes a hard mode in which the pressures in the extension-side back pressure chamber Ce and the compression-side back pressure chamber Cp are controlled to the maximum, and the pressures in the extension-side back pressure chamber Ce and the compression-side back pressure chamber Cp. Can be adjusted steplessly between the soft mode with the lowest control. Then, by adjusting the pressure in the extension side back pressure chamber Ce, the extension side load resulting from the pressure in the extension side back pressure chamber Ce can be controlled. Similarly, by adjusting the pressure in the pressure side back pressure chamber Cp, the pressure side load caused by the pressure in the pressure side back pressure chamber Cp can be controlled, and the pressure in the pressure side back pressure chamber Cp can be adjusted so that the pressure side spool 23 Since the amount of deflection for bending the pressure side second valve body 21 toward the pressure side first valve body 2 can be made variable, the opening amount of the inter-valve gap a can be made variable. That is, in the present embodiment, the changing means A that includes the pressure-side spool 23, the pressure-side back pressure chamber Cp, and the electromagnetic pressure control valve 4 and changes the opening amount of the inter-valve gap a is configured.

  Further, when the pressure in the pressure side back pressure chamber Cp is increased by the electromagnetic pressure control valve 4, the force for urging the pressure side second valve body 21 to the pressure side first valve body 2 side by the pressure side spool 23 becomes larger. The valve body 21 bends downward. The pressure side second valve body 21 is brought into contact with the pressure side first valve body 2 seated on the valve seat 1d by the bending, and the pressure of the pressure side back pressure chamber Cp is set to a pressure that blocks communication between the inter-valve gap a and the extension side chamber R1. If the state in which the pressure is adjusted is set to the medium mode, the communication between the inter-valve gap a and the extension side chamber R1 is maintained from the medium mode to the hard mode.

  Further, the downstream side of the electromagnetic pressure control valve 4 communicates with the expansion side discharge passage Ee and the pressure side discharge passage Ep, and the hydraulic oil that has passed through the electromagnetic pressure control valve 4 is the pressure side chamber on the low pressure side when the shock absorber D is extended. When the shock absorber D is compressed to R2, it is discharged to the low-pressure side expansion chamber R1. Therefore, the adjustment passage Pc is formed by the annular groove 3e, the port 3f, the lateral hole 3g, the port 60b, the notch groove 60c, and a part of the housing portion L described above.

  Further, the electromagnetic pressure control valve 4 has a blocking position in which the through hole 40c in the valve seat member 40 is closed by the small diameter portion 41a in the electromagnetic valve valve body 41 during a failure in which the solenoid Sol cannot be energized. It also functions as an on-off valve. The fail valve 6 opens and closes an annular window 60a communicating with the port 60b, and the valve opening pressure is set to a pressure exceeding the controllable upper limit pressure of the electromagnetic pressure control valve 4. The electromagnetic pressure control valve When the pressure on the upstream side of the electromagnetic pressure control valve 4 exceeds the control upper limit pressure because the port 60b can be communicated with the expansion side discharge passage Ee and the pressure side discharge passage Ep by bypassing 4. The fail valve 6 is opened so that the pressure in the extension side back pressure chamber Ce and the pressure side back pressure chamber Cp can be controlled to the valve opening pressure of the fail valve 6. Therefore, for example, when the electromagnetic pressure control valve 4 is in the cutoff position at the time of a failure, the pressures in the extension side back pressure chamber Ce and the pressure side back pressure chamber Cp are controlled by the fail valve 6.

  Further, when the solenoid valve body 41 is inserted into the valve housing cylinder 40a of the valve seat member 40, the electromagnetic valve valve body 41 forms a space K in the valve housing cylinder 40a on the tip side from the through hole 40c. The space K communicates with the outside of the solenoid valve valve body 41 through a communication path 41e and an orifice 41f provided in the solenoid valve valve body 41. Thereby, when the solenoid valve valve body 41 moves in the axial direction which is the vertical direction in FIG. 5 with respect to the valve seat member 40, the space K functions as a dashpot, and the solenoid valve valve body 41 is suddenly displaced. And the vibrational movement of the solenoid valve body 41 can be suppressed.

  It continues and demonstrates the action | operation of the buffer D provided with the piston valve V1 which is a valve | bulb which concerns on one embodiment of this invention.

  During the compression operation of the shock absorber D in which the rod Dr enters the cylinder Dc, the pressure in the pressure side chamber R2 pressurized by the piston valve V1 deflects the pressure side first valve body 2 upward in FIGS. 1 to 3 through the pressure side passage 1b. Acts like it does. On the other hand, the pressure side first valve body 2 tries to return to the position where it is seated on the valve seat 1d by the spring reaction force of the pressure side first valve body 2 itself. On the other hand, the pressure side second valve body 21 is biased toward the pressure side first valve body 2 by receiving a pressure side load caused by the pressure of the pressure side back pressure chamber Cp.

  Further, the hydraulic oil in the pressure side chamber R2 pushes open the pressure side check valve Tp, passes through the pressure side pressure introduction passage Ip, and flows to the adjustment passage Pc through the pressure side pilot orifice Pp. In this adjustment passage Pc, an electromagnetic pressure control valve 4 is provided. If the solenoid Sol of the electromagnetic pressure control valve 4 is energized to control the pressure upstream of the adjustment passage Pc, the pressure in the pressure-side back pressure chamber Cp is increased. Can be controlled to a desired pressure.

  In the soft mode, the pressure of the pressure-side back pressure chamber Cp is adjusted to be low by the electromagnetic pressure control valve 4, and the force for urging the pressure-side second valve body 21 by the pressure-side spool 23 toward the pressure-side first valve body 2 is small.

  For this reason, in the pressure side low speed region where the piston speed is low and the pressure side first valve body 2 is not opened, the pressure side second valve body 21 does not contact the pressure side first valve body 2 seated on the valve seat 1d. Since the communication between the inter-valve gap a and the extension side chamber R1 is allowed, the hydraulic oil in the compression side chamber R2 to be reduced enters the extension side chamber R1 that expands through the orifice formed by the inter-valve gap a and the notch 2b. The shock absorber D moves and exhibits a compression-side low-speed damping force due to the resistance between the valve element gap a and the notch 2b in the soft mode.

  On the other hand, in the pressure side low speed region from the medium mode to the hard mode in which the pressure of the pressure side back pressure chamber Cp is increased by the electromagnetic pressure control valve 4, the pressure side second valve body 21 is bent toward the pressure side first valve body 2 side. Since the communication between the inter-valve gap a and the expansion side chamber R1 is cut off, the hydraulic fluid in the compression side chamber R2 to be reduced moves to the expansion side chamber R1 expanding through the orifice by the notch 2b, and the shock absorber D Exerts a compression-side slow damping force due to the resistance of the notch 2b. That is, compared with the soft mode in which both the gap a between the valve bodies and the notch 2b can move, the flow path area for the hydraulic oil to move from the compression side chamber R2 to the extension side chamber R1 is increased from the medium mode to the hard mode. Since it becomes narrow by the clearance gap a between valve bodies, compared with soft mode, a big compression side low speed damping force can be exhibited now.

  In the compression-side medium / high-speed region where the piston speed increases during the compression operation, the hydraulic oil pushes and bends the compression-side first valve body 2 and moves from the compression-side chamber R2 to the expansion-side chamber R1 that expands the compression-side passage 1b. In the soft mode, the pressure-side first valve body 2 is received by the pressure of the pressure-side chamber R2 received from the pressure-side passage 1b until the pressure-side first valve body 2 is bent upward in FIGS. The pressure side passage 1b is opened by bending so as to balance the force to bend 2 and the spring reaction force corresponding to the amount of bending of the pressure side first valve body 2 itself.

  Further, in the soft mode, after the pressure side first valve body 2 contacts the pressure side second valve body 21, and from the medium mode where the pressure side second valve body 21 contacts the pressure side first valve body 2 to the hard mode, The pressure-side first valve body 2 and the pressure-side second valve body 21 are configured so that the pressure-side first valve body 2 and the pressure-side second valve body 21 are bent by the pressure of the pressure-side chamber R2 received from the pressure-side passage 1b side, The pressure side passage 1b is opened by bending so that the spring reaction force and the pressure side load corresponding to the bending amount of the first valve body 2 and the pressure side second valve body 21 itself are balanced.

  For this reason, by adjusting the pressure of the pressure side back pressure chamber Cp with the electromagnetic pressure control valve 4, the pressure side load can be controlled to a desired load, and thereby the opening degree of the pressure side first valve body 2 can be controlled. Specifically, if the pressure in the pressure-side back pressure chamber Cp is adjusted to be low, the pressure-side load is reduced and the opening of the pressure-side first valve body 2 can be increased, so that the resistance by the pressure-side first valve body 2 is reduced. The compression side medium and high speed damping force of the shock absorber D caused by the resistance can be reduced. On the other hand, if the pressure in the pressure side back pressure chamber Cp is adjusted to be high, the pressure side load increases and the opening degree of the pressure side first valve body 2 can be reduced. The compression side medium and high speed damping force of the shock absorber D can be increased.

  The hydraulic oil that has passed through the adjustment passage Pc pushes the check valve 34 open and is discharged to the low pressure side expansion chamber R1 via the pressure side discharge passage Ep. Note that the pressure side pilot orifice Pp gives a resistance and a pressure loss when the hydraulic oil passes, so that the pressure side pilot orifice Pp has a lower pressure than the pressure side chamber R2 downstream of the adjustment passage Pc when the hydraulic oil is flowing. The check valve 35 provided in the extension-side discharge passage Ee does not open and remains closed.

  Further, the pressure side pressure introduction passage Ip not only communicates with the expansion side back pressure chamber Ce, but also communicates with the pressure side back pressure chamber Cp through the communication passage 33, and when the shock absorber D is compressed, the pressure side back pressure chamber Cp. Since the internal pressure becomes higher than that of the expansion side chamber R1, the expansion side pressure introduction passage Ie remains blocked by the expansion side check valve Te.

  Subsequently, during the extension operation of the shock absorber D in which the rod Dr retreats from the cylinder Dc, the pressure in the extension side chamber R1 pressurized by the piston valve V1 moves the extension side valve element 5 through the extension side passage 1a in FIGS. It acts to bend downward. On the other hand, the extension side valve element 5 tries to return to the position where it is seated on the valve seat 1c by the spring reaction force of the extension side valve element 5 itself, and the extension side caused by the pressure in the extension side back pressure chamber Ce. Under load, it is biased toward the valve disc 1 side.

  Further, the hydraulic oil in the extension side chamber R1 pushes open the extension side check valve Te, passes through the extension side pressure introduction passage Ie, and flows to the adjustment passage Pc through the extension side pilot orifice Pe. An electromagnetic pressure control valve 4 is provided in the adjustment passage Pc, and if the solenoid Sol of the electromagnetic pressure control valve 4 is energized to control the pressure upstream of the adjustment passage Pc, the expansion side back pressure chamber Ce The pressure can be controlled to a desired pressure.

  In the soft mode, the pressure in the compression-side back pressure chamber Cp is the same as the pressure in the expansion-side chamber R1, and the compression-side spool 23 is designed so that the expansion-side pressure introduction passage Ie does not give resistance to the flow of hydraulic oil. Since no force is generated to urge the pressure side second valve body 21 to the pressure side first valve body 2 side, the communication between the inter-valve gap a and the extension side chamber R1 is maintained.

  For this reason, in the extension side low speed region where the piston speed is low and the extension side valve element 5 is not opened, the hydraulic oil in the extension side chamber R1 to be reduced expands through the orifice between the valve element gap a and the notch 2b. Since it moves to R2, the shock absorber D exhibits the extension side low-speed damping force resulting from the resistance of the inter-valve gap a and the notch 2b in the soft mode.

  Further, even in the extension side low speed region from the medium mode to the hard mode, the hydraulic oil in the extension side chamber R1 to be reduced moves to the pressure side chamber R2 that expands through the orifice by the gap a between the valve bodies and the notch 2b. D exhibits the extension side low-speed damping force resulting from the resistance of the clearance a between the valve bodies and the notch 2b.

  In the extension side medium and high speed region where the piston speed becomes high during the extension operation, the hydraulic oil pushes and flexes the extension side valve body 5 and moves the extension side passage 1a from the extension side chamber R1 to be reduced to the pressure side chamber R2. . The extension side valve element 5 has a force to bend the extension side valve element 5 by the pressure of the extension side chamber R1 received from the extension side passage 1a side, and a spring reaction force according to the amount of deflection of the extension side valve element 5 itself. The extension side passage 1b is opened by bending so as to balance the extension side load.

  For this reason, by adjusting the pressure of the extension side back pressure chamber Ce between the soft mode and the hard mode with the electromagnetic pressure control valve 4, the extension side load is controlled to a desired load. The opening degree can be controlled. Specifically, if the pressure in the extension side back pressure chamber Ce is adjusted to be low, the extension side load can be reduced and the opening degree of the extension side valve element 5 can be increased, so that the resistance by the extension side valve element 5 is reduced. It is possible to reduce the extension side medium and high speed damping force of the shock absorber D caused by the resistance. On the other hand, if the pressure in the extension side back pressure chamber Ce is adjusted to be high, the extension side load increases and the opening of the extension side valve element 5 can be reduced, so that the resistance by the extension side valve element 5 increases, It is possible to increase the middle- and high-speed damping force of the shock absorber D due to the extension.

  The hydraulic oil that has passed through the adjustment passage Pc pushes the check valve 35 open and is discharged to the low pressure side pressure side chamber R2 through the expansion side discharge passage Ee. The expansion side pilot orifice Pe gives resistance when the hydraulic oil passes and causes a pressure loss. In a state where the hydraulic oil flows, the expansion side pilot orifice Pe has a lower pressure than the expansion side chamber R1 downstream of the adjustment passage Pc. The check valve 34 provided in the pressure side discharge passage Ep is not opened and remains closed.

  The extension side pressure introduction passage Ie not only communicates with the compression side back pressure chamber Cp but also with the extension side back pressure chamber Ce via the communication passage 33. Since the pressure in the pressure chamber Ce becomes higher than that in the pressure side chamber R2, the pressure side pressure introduction passage Ip remains closed by the pressure side check valve Tp.

  The piston speed is divided into a low speed region and a medium high speed region during the expansion operation and compression operation of the shock absorber D in the present embodiment, but the threshold value of each region can be arbitrarily set. It is.

  It continues and demonstrates the effect of the piston valve V1 which is a valve | bulb which concerns on this Embodiment, and the buffer D provided with the said piston valve V1.

  In the shock absorber D for the vehicle, it is necessary to increase the extension side damping force during the extension operation compared to the compression side damping force during the compression operation. The pressure receiving area that receives the pressure of R1 may be an area obtained by subtracting the cross-sectional area of the rod member 31 from the cross-sectional area of the valve disk 1, and the pressure in the expansion side chamber R1 during the expansion operation is the pressure side chamber R2 during the compression operation. It must be very large compared to the pressure of

  On the other hand, in the shock absorber D of the present embodiment, when the extension side back pressure chamber Ce and the compression side back pressure chamber Cp are at the same pressure, the extension side load that biases the extension side valve element 5. Is larger than the pressure side load for urging the pressure side first valve body 2 and the pressure side second valve body 21. Further, in the present invention, by using the expansion side spool 51, compared with a structure in which the pressure of the expansion side back pressure chamber Ce is applied to the back side of the expansion side valve body 5 without using the expansion side spool 51. The pressure receiving area that receives the pressure of the extension side back pressure chamber Ce of the extension side spool 51 can be made larger than the back surface area of the extension side valve element 5, and a large extension side load is applied to the extension side valve element 5. be able to. Furthermore, by using the extension side spool 51 and the compression side spool 23, the degree of freedom in designing the extension side load and the compression side load is also improved.

  Therefore, in the shock absorber D having the above-described configuration, the pressure in the extension-side back pressure chamber Ce is increased when the extension-side load needs to be very large in order to adjust the extension-side damping force during the extension operation. Even if it is small, it can be set so as to output a large extension side load, and the control range of the extension side damping force can be secured without using a large solenoid Sol.

  In addition, pressure control of the extension side back pressure chamber Ce and the pressure side back pressure chamber Cp is not performed by driving independent valve bodies, but by increasing the extension side load relative to the compression side load, the extension side back pressure is increased. Even if the pressures in the chamber Ce and the pressure side back pressure chamber Cp are communicated and controlled, the control range of the extension side damping force can be secured, so the electromagnetic pressure control valve 4 is provided with one electromagnetic valve valve body 41. All that is required is a very simple structure and reduced costs.

  As described above, the solenoid Sol in the electromagnetic pressure control valve 4 can be reduced in size, and the structure of the electromagnetic pressure control valve 4 is simplified, and the shock absorber D is not enlarged even when applied to the piston portion of the shock absorber D. . Therefore, according to the shock absorber D, the structure of the shock absorber D can be simplified and miniaturized, and the solenoid Sol is large in increasing the extension side damping force without deteriorating the mountability on the vehicle. Since it is not necessary to exhibit thrust, power consumption when increasing damping force can be reduced to save power.

  Further, since the pressure receiving area for receiving the pressure of the expansion side back pressure chamber Ce of the expansion side spool 51 is made larger than the pressure receiving area for receiving the pressure of the compression side back pressure chamber Cp of the compression side spool 23, the expansion side load can be easily converted into the compression side load. It can be made larger than that.

  Further, the expansion side back pressure chamber Ce and the compression side back pressure chamber Cp are communicated with each other through the communication path 33 through the compression side resistance element and the expansion side resistance element, respectively, and the compression side pressure introduction path Ip has almost no resistance. Since hydraulic oil is introduced into the pressure chamber Ce from the pressure side chamber R2, when the shock absorber D switches from the expansion operation to the compression operation, the pressure in the pressure side chamber R2 is quickly introduced into the expansion side back pressure chamber Ce, The extension side spool 51 presses the extension side valve body 5 by the pressure in the extension side back pressure chamber Ce and the urging of the spring member 53 so that the extension side valve body 5 is quickly seated on the valve seat 1c, and the extension side passage 1a can be closed. The expansion side pressure introduction passage Ie also introduces hydraulic oil from the expansion side chamber R1 to the compression side back pressure chamber Cp with almost no resistance. Conversely, when the shock absorber D switches from the compression operation to the expansion operation, the compression side back pressure chamber Cp The pressure in the extension side chamber R1 is rapidly introduced into the pressure side spool 23, and the pressure side spool 23 presses the pressure side second valve body 21 toward the pressure side first valve body 2 by the pressure in the pressure side back pressure chamber Cp and the spring member 25. can do.

  Further, the annular plate 26 which is a check valve body in the extension side check valve Te and the annular plate 54 which is a check valve valve body in the pressure side check valve Tp are deteriorated over time, and the corresponding pressure side chamber 24 and extension side chamber are correspondingly deteriorated. Even if a gap is generated between the pressure side resistance element 52 and the pressure side back pressure chamber Cp, the pressure side resistance element is provided on the downstream side of the pressure side pressure introduction path Ip and the pressure side pressure introduction path Ip. Since it is provided downstream of the chamber Ce, even if the flow rate passing through the expansion side pressure introduction passage Ie and the pressure side pressure introduction passage Ip changes, the damping force control and the valve closing operation at the time of expansion / contraction switching are affected. There is nothing.

  Further, a valve disc 1 having an extension side passage 1a and a pressure side passage 1b on the outer peripheral side of the rod Dr, an extension side valve body 5, a pressure side first valve body 2 and a pressure side second valve laminated on the valve disc 1. The body 21, the cylinder-shaped extension side spool 51 in which the extension side spool 51 is slidably inserted in the inner periphery and the extension side back pressure chamber Ce is formed, and the cylinder, the pressure side spool in the inner periphery. 23 is slidably inserted, and a pressure side chamber 24 forming a pressure side back pressure chamber Cp is mounted, a pressure side pressure introduction passage Ip is provided in the extension side chamber 52, and an extension side pressure introduction passage is provided in the pressure side chamber 24. Since Ie is provided, each member required for adjusting the damping force can be concentrated on the piston portion of the shock absorber D.

  Further, the biasing of the expansion side spool 51 toward the expansion side valve body 5 and the urging of the annular plate 54 as a check valve valve body in the pressure side check valve Tp that opens and closes the pressure side pressure introduction passage Ip are provided as one spring. Energizing the pressure side spool 23 to the pressure side second valve body 21 side and energizing the annular plate 26 as a check valve body in the extension side check valve Te that opens and closes the extension side pressure introduction passage Ie. Is performed by one spring member 25, so that the check valves Te and Tp and the spools 51 and 23 can be restored to the return side by one spring member 53 and 25, thereby reducing the number of parts. can do.

Further, the shock absorber D is provided at the tip of the rod Dr, and the valve disc 1, the extension side valve body 5, the pressure side first valve body 2, the pressure side second valve body 21, the extension side chamber 52, and the pressure side chamber 24 are arranged on the outer periphery. An extension side pilot as an extension side resistance element that is provided in the holding shaft 3a, a vertical hole 3d that opens from the tip of the holding shaft 3a, and a communication path 33 provided in the holding shaft 3a and provided in the vertical hole 3d. An orifice Pe and a pressure-side pilot orifice Pp as a pressure-side resistance element, a housing portion L that is provided inside and accommodates the electromagnetic pressure control valve 4 through the vertical hole 3d, and an adjustment passage that communicates the communication passage 33 with the housing portion L Pc and a pressure side discharge passage Ep that communicates the accommodating portion L with the expansion side chamber R1 are provided, and the expansion side back pressure chamber Ce and the pressure side are inserted into the vertical hole 3d by an annular groove 32a that is inserted into the vertical hole 3d and provided on the outer periphery. A communication path communicating with the back pressure chamber Cp 3 and the separator 32 that forms the extended-side discharge passage Ee on the inner periphery, the electromagnetic pressure control valve 4 is accommodated in the rod Dr without any difficulty and is shifted in the axial direction from the electromagnetic pressure control valve 4. An extension-side back pressure chamber Ce and a compression-side back pressure chamber Cp can be provided on the outer periphery of the rod Dr.

Furthermore, the electromagnetic pressure control valve 4 is set to close the adjustment passage Pc when not energized and to perform pressure control when energized, and includes a fail valve 6 provided in the middle of the adjustment passage Pc to bypass the electromagnetic pressure control valve 4; Since the valve opening pressure of the fail valve 6 is made larger than the maximum control pressure by the electromagnetic pressure control valve 4, at the time of failure, the extension side load and the pressure side load become maximum, and the shock absorber D exhibits the largest damping force, and fails. Even at times, the body posture can be stabilized.

  In addition, when the electromagnetic pressure control valve 4 takes the cutoff position, the small diameter portion 41a of the electromagnetic valve valve body 41 is opposed to the through hole 40c, and the through hole 40c is closed to close the valve. In addition, it is possible to function as a throttle valve by closing the through-hole 40c without causing the through-hole 40c to close and slightly facing the through-hole 40c at the blocking position. In this way, the damping characteristic of the shock absorber D at the time of failure can be added with the characteristic of the cutoff position throttle valve in the electromagnetic pressure control valve 4 in the region where the piston speed is low. Riding comfort can be improved.

  Furthermore, the electromagnetic pressure control valve 4 is provided in the end part of the valve storage cylinder 40a and the valve storage cylinder 40a which are cylindrical and have the through-hole 40c which connects inside and outside, and forms a part of adjustment passage Pc. A valve seat member 40 having an annular control valve valve seat 40d, a small diameter portion 41a slidably inserted into the valve housing cylinder 40a, a large diameter portion 41b, the small diameter portion 41a, and the large diameter portion 41b, a recess 41c that can be opposed to the through hole 40c, and an electromagnetic valve valve body 41 that allows the end of the large diameter part 41b to be separated from and seated on the control valve valve seat 40d, with a small diameter in the through hole 40c. The adjustment passage Pc is blocked by facing the portion 41a. Therefore, the pressure receiving area in which the pressure acts in the direction in which the solenoid valve body 41 is removed from the valve seat member 40 is a circle having the outer diameter of the small diameter portion 41a as the diameter from the area of the circle having the inner diameter of the control valve valve seat 40d as the diameter. As a result of subtracting the area, the pressure receiving area can be greatly reduced, and the flow path area at the time of valve opening can be increased. Therefore, the necessary thrust of the solenoid Sol is small, and the movement amount of the solenoid valve valve body 41 is small, so that the movement of the solenoid valve valve body 41 is stabilized. Further, since the outer periphery of the small-diameter portion 41a is opposed to the through hole 40c to close the through hole 40c, the valve is kept closed even when pressure is applied from the upstream side in the blocking position, and only the fail valve 6 is effective. can do.

  Further, in the present embodiment, the changing means A that changes the opening amount of the inter-valve gap a is a pressure-side spool that contacts the outer periphery of the intermediate spacer 20 on the counter-pressure side first valve body side of the pressure-side second valve body 21. 23, a pressure-side back pressure chamber Cp that urges the pressure-side spool 23 toward the pressure-side first valve body 2 with internal pressure, and an electromagnetic pressure control valve 4 that controls the internal pressure of the pressure-side back pressure chamber Cp. Configured. For the purpose of only changing the opening amount of the clearance a between the valve bodies, a solenoid with a small thrust can be employed even if the compression side spool 23 is directly driven by the solenoid Sol. However, in this case, as in the present embodiment, when the damping force is also adjusted by the solenoid Sol, it is necessary to employ a solenoid having a large thrust, and there is a problem that the piston valve V1 has a large diameter. On the other hand, in the present embodiment, the pressure in the pressure side back pressure chamber Cp is adjusted by the electromagnetic pressure control valve 4 to control the pressure side load acting on the pressure side first valve body 2 and the pressure side second valve body 21. Therefore, even if the opening amount of the inter-valve gap a and the damping force are adjusted with one solenoid Sol, a small solenoid Sol can be employed.

  Further, in the present embodiment, the piston valve V1 includes an intermediate spacer 20 interposed between the pressure side first valve body 2 and the pressure side second valve body 21, and the pressure side first valve body 2 and the pressure side first valve body 21 are provided. A hole 2a is formed between the two valve bodies 21 on the outer periphery of the intermediate spacer 20 and between the pressure side passage 1b and the valve body gap a. And a changing means A for biasing the pressure side second valve body 21 toward the pressure side first valve body 2 to change the opening amount of the inter-valve gap a. Therefore, the low-speed damping force can be varied by changing the opening amount of the inter-valve gap a by the changing means A. Even if the opening amount of the inter-valve gap a is increased to reduce the low-speed damping force in the soft mode, the communication between the inter-valve gap a and the extension side chamber R1 is blocked from the medium mode to the hard mode. Therefore, it is possible to increase the variable damping force range.

  In the present embodiment, the present invention is embodied only in a configuration that opens and closes the compression side passage 1b. However, the present invention may be embodied in a configuration that opens and closes the extension side passage 1a. It is good.

  Further, in the present embodiment, a notch 2b for forming an orifice is provided in the outer peripheral portion of the pressure side first valve body 2, but the valve seat 1d on which the pressure side first valve body 2 is seated is notched or grooved. And an orifice may be formed by the embossing or groove. Further, an orifice is formed by the notch, the notch, and the groove by providing a notch in the outer peripheral portion of the extension-side valve body 5 or by providing a notch or groove in the valve seat 1c on which the extension-side valve element 5 is seated. However, it is not always necessary to provide notches, stamps, or grooves.

  Further, in the present embodiment, the valve according to the present invention is the piston valve V1, but the shock absorber is a uniflow type shock absorber as disclosed in, for example, Japanese Patent Application Laid-Open No. 2013-177976. 6, a cylinder Dc, a rod Dr that enters and exits the cylinder Dc, a piston valve V2 that is held at the tip of the rod Dr, a base valve V3 that is fixed to the opposite end of the cylinder Dc, The extension side chamber R1 and the pressure side chamber R2 formed in the cylinder Dc and defined by the piston valve V2, the reservoir R3 formed outside the cylinder Dc and defined by the base valve V3 and the pressure side chamber R2, and the extension side chamber R1 and the reservoir When the discharge passage 8 communicating with R3 and the damping valve V4 provided in the middle of the discharge passage 8 are provided, the valve according to the present invention is provided with a damping valve. It may be used as a blanking V4.

  In such a uniflow-type shock absorber, the piston valve V2 allows only the flow of hydraulic oil that moves from the pressure side chamber R2 to the expansion side chamber R1, and the base valve V3 moves from the reservoir R3 to the pressure side chamber R2. Only the flow of is allowed. During the expansion operation of the shock absorber, the hydraulic oil in the expansion side chamber R1 to be reduced moves through the discharge passage 8 to the reservoir R3, and an amount of hydraulic oil corresponding to the rod withdrawal volume passes through the base valve V3. It moves from the reservoir R3 to the compression side chamber R2. On the contrary, during the compression operation of the shock absorber, the hydraulic oil in the compression side chamber R2 to be reduced moves to the expansion side chamber R1 that passes through the piston valve V2 and expands, and an amount of hydraulic oil corresponding to the rod entry volume is discharged. 8 is discharged from the extension side chamber R1 to the reservoir R3.

  As shown in FIG. 7, unlike the piston valve V1 of the embodiment, the damping valve V4 partitions the expansion side chamber R1 and the reservoir R3 with the valve disc 100, but, like the piston valve V1, two chambers are provided. A valve disc 100 that partitions, a passage 101 that is formed in the valve disc 100 and communicates with a chamber partitioned by the valve disc 100, and a ring-plate-shaped first valve that is stacked on the valve disc 100 and opens and closes the passage 101 Body 200, an annular intermediate spacer 201 which is laminated on the side opposite to the valve disc of the first valve body 200 and whose outer diameter is smaller than the outer diameter of the first valve body 200, and the anti-valve disc of the intermediate spacer 201 A ring-shaped second valve body 202 having a larger outer diameter than that of the intermediate spacer 201, and the intermediate spacer 20 between the first valve body 200 and the second valve body 202. Between the valve body a formed on the outer periphery of the valve body, a hole 200a formed in the first valve body 200 for communicating the passage 101 and the clearance a between the valve bodies, and the second valve body 202 on the first valve body 200 side. And changing means A for changing the opening amount of the inter-valve gap a.

  According to the above configuration, since the hydraulic oil passes through the damping valve V4 and moves from the expansion side chamber R1 to the reservoir R3 during both the expansion operation and the compression operation of the shock absorber, the valve body is used during both the expansion operation and the compression operation. The low-speed damping force can be adjusted by changing the opening amount of the gap a. Furthermore, since the clearance a between valve bodies can be closed, the damping force variable width can be increased.

  Also in the present embodiment, similarly to the first embodiment, the changing means A includes the spool 203 that contacts the outer periphery of the intermediate spacer 201 on the side opposite to the first valve body of the second valve body 202, and the internal pressure. The back pressure chamber C for urging the second valve body 202 toward the first valve body 200 and an electromagnetic pressure control valve (not shown) for controlling the internal pressure of the back pressure chamber C are provided, although not shown in detail. , A pressure introducing passage I for guiding the pressure from the expansion side chamber R1 side to the electromagnetic pressure control valve, an adjustment passage connected to the back pressure chamber C and provided with the electromagnetic pressure control valve, and hydraulic oil that has passed through the electromagnetic control valve In this case, the configuration of the changing means A for changing the opening amount of the inter-valve gap a is not limited to this.

  Although preferred embodiments of the present invention have been described in detail above, it should be understood that modifications, variations and changes may be made without departing from the scope of the claims.

a Inter-valve clearance A Changing means C Back pressure chamber Cp Pressure side back pressure chamber (back pressure chamber)
R1 extension side chamber (one chamber in one embodiment, the other chamber in another embodiment)
R2 pressure side chamber (the other chamber in one embodiment)
R3 reservoir (one chamber in other embodiments)
V1 Piston valve (valve)
V4 Damping valve (valve)
1,100 Valve disc 1b Pressure side passage (passage)
2 Pressure side first valve element (first valve element)
2a, 200a Hole 4 Electromagnetic pressure control valve 20, 201 Intermediate spacer 21 Pressure side second valve body (second valve body)
23 Pressure side spool (spool)
101 passage 200 first valve body 202 second valve body 203 spool

Claims (2)

A valve disk that divides the one chamber and the other chamber;
A passage communicating the hand chamber and the other chamber above is formed in the valve disc,
An annular plate-like first valve body that is stacked on the valve disc and opens and closes the passage;
An annular intermediate spacer that is laminated on the side opposite to the valve disc of the first valve body and whose outer diameter is smaller than the outer diameter of the first valve body;
An annular plate-like second valve body laminated on the valve disc side of the intermediate spacer and having an outer diameter larger than the outer diameter of the intermediate spacer;
The inter-valve gap formed on the outer periphery of the intermediate spacer between the first valve body and the second valve body,
A hole formed in the first valve body to communicate the passage and the gap between the valve bodies;
Changing means for urging the second valve body toward the first valve body side to change the opening amount between the valve body gaps ;
The changing means includes a back pressure chamber that biases the second valve body toward the first valve body with internal pressure, and an electromagnetic pressure control valve that controls the internal pressure of the back pressure chamber. Valve to do. A valve disk that divides the one chamber and the other chamber;
A passage formed in the valve disk and communicating with the one chamber and the other chamber;
An annular plate-like first valve body that is stacked on the valve disc and opens and closes the passage;
An annular intermediate spacer that is laminated on the side opposite to the valve disc of the first valve body and whose outer diameter is smaller than the outer diameter of the first valve body;
An annular plate-like second valve body laminated on the valve disc side of the intermediate spacer and having an outer diameter larger than the outer diameter of the intermediate spacer;
The inter-valve gap formed on the outer periphery of the intermediate spacer between the first valve body and the second valve body,
A hole formed in the first valve body to communicate the passage and the gap between the valve bodies;
Changing means for urging the second valve body toward the first valve body side to change the opening amount between the valve body gaps;
The change means includes a spool that is in contact with the outer periphery of the intermediate spacer on the anti-first valve body side of the second valve body, a back pressure chamber that biases the spool toward the first valve body side with internal pressure, An electromagnetic pressure control valve for controlling the internal pressure of the back pressure chamber.

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