JP5597074B2 - damper - Google Patents

Description

  The present invention relates to a damper, and more particularly to an improvement of a damper used for a seismic isolation device or a vibration control device for a structure, for example.

  For example, as dampers used for seismic isolation devices and damping devices for structures, various proposals have been made so far. Among them, the dampers disclosed in Patent Document 1 and Patent Document 2 are dampers. The outer cylinder disposed on the outer periphery of the inner cylinder is connected to the bottom member and the head member by welding.

  That is, Patent Document 1 discloses that the head side end of the outer cylinder in the damper is welded to a connecting member in series with the head member, and Patent Document 2 discloses that the bottom side end of the outer cylinder in the damper is the bottom member. It is disclosed that it is welded.

  In other words, as shown in FIG. 2 that summarizes this, the dampers so far made it possible to make the tip side of the rod body 2 on the right side in the drawing of the inner cylinder 1 filled with the working oil as the working fluid appear and disappear. The rod-side chamber R1 and the piston-side chamber R2 are defined in the inner cylinder 1 by the piston body 3 that is inserted through the piston body 3 that is held at the tip portion that is the right end portion in the drawing.

  In this damper, the outer cylinder 4 is provided outside the inner cylinder 1, and the reservoir R is set between the outer cylinder 4 and the inner cylinder 1. Among these, it is possible to communicate with the piston side chamber R <b> 2 in the inner cylinder 1 through a base valve portion 5 that is held inside the bottom side that is the right end portion.

  Since the damper shown in the figure is set to a uniflow type, the rod side chamber R1 in the inner cylinder 1 does not communicate with the piston side chamber R2 via the piston body 3, but communicates with the reservoir R.

  By the way, in this damper, the head side end which becomes the left end in the drawing of the outer cylinder 4 is connected to the connecting member 7 in series with the head member 6 constituting the head end portion which becomes the left end portion in the drawing of the damper. Are welded as indicated by the symbol M.

  And in this damper, the bottom side 8 which becomes the right end in the figure of the outer cylinder 4 is similarly shown by the symbol M in the figure in the bottom member 8 which constitutes the bottom end part which becomes the right end part in the figure of the damper. So that it is welded.

  Incidentally, the head member 6 has the rod body 2 under the arrangement of the bush 6a and the check seal 6b while closing the head side end which is the left end in the figure in the inner cylinder 1 positioned at the axial center portion of the outer cylinder 4. Through the shaft core.

  The connecting member 7 closes the head side end of the outer cylinder 4, and the head member 6 connected in series is integrally connected by screwing the connecting pin 9.

  The bottom member 8 closes the bottom side end which is the right end in the figure of the inner cylinder 1 and closes the bottom side end of the outer cylinder 4.

  Therefore, in the damper shown in FIG. 2, the head side end of the outer cylinder 4 is welded to the connecting member 7 connected to the head member 6 and the bottom side end is welded to the bottom member 8. It is possible to prevent the hydraulic oil stored in the damper from leaking out from a so-called connecting portion in the outer cylinder 4.

Japanese Patent Laying-Open No. 2005-315276 (see paragraph 0008 in FIG. 3, FIG. 3) Japanese Patent Laying-Open No. 2005-207488 (see FIG. 4)

  However, in the damper shown in FIG. 2 that summarizes the points disclosed in Patent Literature 1 and Patent Literature 2 described above, leakage of hydraulic oil contained in the damper from a so-called connecting portion to the outside can be prevented. In this respect, it is not basically a problem, but it may be pointed out that there is a minor defect in its implementation.

  That is, in the assembly procedure for the damper shown in FIG. 2 described above, first, the bottom side end of the outer cylinder 4 is closed with the bottom member 8, and the bottom side end of the outer cylinder 4 is closed under this condition. Weld to.

Next, the head side end of the outer cylinder 4 is closed by the connecting member 7, and the head side end of the outer cylinder 4 is welded to the connecting member 7 under this state.

Thereafter , the inner cylinder 1 is inserted so as to be positioned at the axial core portion of the outer cylinder 4, and the head side end of the inner cylinder 1 is inserted by the head member 6 that penetrates the rod body 2 having the piston body 3 at the distal end portion into the axial core portion. The head member 6 is connected to the connecting member 7 in series, and the head member 6 is integrated with the connecting member 7 by screwing the connecting pin 9.

  At this time, when the outer cylinder 4 is welded to the bottom member 8 and the connecting member 7, it is not easy to prevent the outer cylinder 4 from generating distortion due to welding heat. The rule of thumb is that it is virtually difficult to make the widths absolutely uniform.

  Therefore, in the above-described conventional damper, the length in the axial direction of the outer cylinder 4 after welding is different from that of the inner cylinder 1 due to the difference in the welding width and the distortion caused by the welding heat introduced to the outer cylinder 4. It is essential that the axial length is not set according to the setting.For this reason, in the production of the damper, careful assembly work is required, which makes it easy to reduce workability or after welding. Machining is required, resulting in high costs.

  The present invention was devised in view of the above-described circumstances, and its purpose is not only to provide a predetermined damping action, but also to improve the workability during assembly, and its general purpose. It is to provide a damper that is optimal for expecting improved performance.

In order to achieve the above object, one of the problem solving means of the present invention is:
An inner cylinder filled with working fluid;
A rod body whose tip side is inserted into the inner cylinder so as to be capable of appearing and retracting;
A piston body that is held at the tip of the rod body and is slidably accommodated in the inner cylinder while defining a rod side chamber and a piston side chamber in the inner cylinder;
An outer cylinder disposed outside the inner cylinder and defining a reservoir with the inner cylinder;
A base valve portion disposed inside the bottom side of the inner cylinder,
A head member that closes the head side end of the outer cylinder and the head side end of the inner cylinder while passing the rod body through the shaft core;
While fixing the base valve portion has a bottom member closing a bottom end at the bottom end and above of the inner tube in the outer tube,
In the damper that performs a predetermined damping action in the damping portion during the expansion and contraction operation in which the rod body appears and disappears with respect to the inner cylinder,
The bottom-side end portion is screwed under liquid-tight structure in the bottom member of the causes is screwed the head-side end of the inner cylinder under liquid-tight structure in the head member of the above,
The head-side end of the outer tube adjacent to the distribution設下the seal head members described above,
The outer diameter of the bottom member is formed to be smaller than the inner diameter of the bottom end of the outer cylinder, and a spacer with a seal wound is inserted into the gap between the bottom member and the bottom end. Let
Furthermore, the bottom end portion of the outer cylinder and the spacer are connected to the bottom member under the arrangement of the fixing means .
Similarly, other means are:
An inner cylinder filled with working fluid;
A rod body whose tip side is inserted into the inner cylinder so as to be capable of appearing and retracting;
A piston body that is held at the tip of the rod body and is slidably accommodated in the inner cylinder while defining a rod side chamber and a piston side chamber in the inner cylinder;
An outer cylinder disposed outside the inner cylinder and defining a reservoir with the inner cylinder;
A base valve portion disposed inside the bottom side of the inner cylinder,
A head member that closes the head side end of the outer cylinder and the head side end of the inner cylinder while passing the rod body through the shaft core;
A bottom member that closes the bottom side end of the outer cylinder and the bottom side end of the inner cylinder while fixing the base valve portion;
In the damper that performs a predetermined damping action in the damping portion during the expansion and contraction operation in which the rod body appears and disappears with respect to the inner cylinder,
The head-side end of the inner cylinder is screwed to the head member under a liquid-tight structure and the bottom-side end is screwed to the bottom member under a liquid-tight structure,
The outer diameter of the bottom member is formed to be smaller than the inner diameter of the bottom side end portion of the outer cylinder, and the reduced diameter has an inner diameter that matches the outer diameter of the bottom member at the bottom side end portion of the outer cylinder. Forming part,
The head side end of the outer cylinder is adjacent to the head member under the arrangement of the seal,
The bottom side end of the outer cylinder is adjacent to the bottom of the seal while the reduced diameter portion is in contact with the outer periphery of the bottom member,
The bottom end portion of the outer cylinder is connected to the bottom member under the arrangement of the fixing means .

  Therefore, according to the present invention, the inner cylinder filled with the working fluid causes the head side end to be screwed to the head member under the liquid-tight structure and the bottom side end to be screwed to the bottom member under the liquid-tight structure. Therefore, leakage of working fluid from the rod side chamber and piston side chamber in the inner cylinder to the outside of the inner cylinder can be prevented, so that the rod side chamber and piston side chamber can be maintained at the required pressure state, and the damping action by the damping section is as set. Can be realized.

  According to the present invention, since the working fluid in the inner cylinder does not leak out of the inner cylinder, the reservoir defined between the inner cylinder and the outer cylinder bears a fluid pressure that ensures the operation of the attenuation portion. Therefore, it is sufficient to generate a so-called tank function, and the structure for connecting the outer cylinder to the head member and the bottom member can be simplified, so that the workability during assembly can be improved.

  Also, according to the present invention, the bottom side end of the outer cylinder whose head side end is adjacent to the head member is adjacent to the bottom member, while the bottom side end is under the arrangement of the fixing means. Since it is connected to the bottom member, it is not necessary to generate distortion due to welding in the outer cylinder as compared with the case where it is connected by welding as in the technique disclosed in Patent Document 1 described above. There is no need to worry about variations in the finished length of the outer cylinder with respect to the set length.

  As a result, the occurrence of variations in the finished length of the outer cylinder relative to the set length of the inner cylinder can be prevented, so that no post-processing such as post-processing of the head member is required, and the occurrence of rattling in the inner cylinder can be prevented. Can be prevented from leaking out or fluid pressure can be released, improving the workability during assembly and reducing the product cost, so that the versatility can be expected to be improved.

It is sectional drawing which cuts and shows the damper by this invention partially. It is a figure which shows the damper made into a prior art example similarly to FIG.

  Hereinafter, the present invention will be described based on the illustrated embodiment. The damper according to the present invention is preferably used for, for example, a seismic isolation device or a vibration control device for a structure.

  By the way, according to the configuration of the present invention, this damper is used, for example, in a suspension device that is mounted on a vehicle and absorbs road surface vibrations input to wheels, or used in an exhibition stand on which exhibits are placed. Of course, it may be done.

  However, when the damper according to the present invention is used for a seismic isolation device or a vibration control device for a structure and a case where the damper is used for a suspension device or an exhibition stand, the damper is used for a seismic isolation device for a structure. In some cases, the scale is larger overall, and the parts are formed to be similar and larger. Therefore, from the viewpoint of realizing the present invention, it will be advantageous to be used for a seismic isolation device for a structure. .

  On the other hand, unlike dampers used for suspension devices in vehicles, dampers used in seismic isolation devices for structures should have the same damping action during telescopic operation, whereas suspension devices in vehicles In the damper used in the above, it is rare that the damping action on the extension side or the compression side is the same. Rather, the damping action on the extension side and the damping action on the compression side should be positively different. There is a tendency.

  Therefore, the damper according to the present invention is used for a seismic isolation device for a structure and the like, and is set to a uniflow type as described later, so that it is easy to make the damping action at the time of expansion / contraction operation the same. I have to.

  That is, the damper according to the present invention is basically formed in the same manner as the damper shown in FIG. 2 as shown in FIG. 1, and includes an inner cylinder 1, a rod body, a piston body 3, The outer cylinder 4, the base valve portion 5, the head member 6, and the bottom member 8 are provided.

  The inner cylinder 1 is filled with working oil as a working fluid. In the drawing, the inner side 1 is a head side end 1a which is a left end in the figure and a bottom end 1b which is a right end in the figure. It has a cylinder that has both ends open.

  The inner cylinder 1 has an outer peripheral thread 1c on the outer periphery of the head-side end 1a, and can be screwed to a head member 6 described later. A circumferential thread 1d is provided to enable screwing to a bottom member 8 described later.

  Incidentally, when the inner cylinder 1 is screwed to the head member 6 to be described later, as shown in the drawing, the lock nut 11 screwed on the outer peripheral thread 1c is tightened to the head member 6. Fix the screwed state.

  The rod body 2 is inserted into the inner cylinder 1 so that the tip side on the right side in the figure can be projected and retracted. In this damper, the bottom member 8 is, for example, on the fixed side which is one side. When connected, the rod body 2 is connected to the movable side which is the other side, and when the movement of the movable side with respect to the fixed side is expressed, the rod body 2 is attached to the inner cylinder 1 screwed to the bottom member 8. The damper will extend and retract.

  Incidentally, in the illustrated embodiment, the damper is set to be a uniflow type, and the setting is made such that the flow rate of the hydraulic oil during the expansion / contraction operation is the same, so that the cross-sectional area of the rod body 2 and the inner circumference of the inner cylinder 1 described above The sectional area on the side is set to 1: 2.

  The piston body 3 is held at the tip end portion which is the right end portion in the drawing of the rod body 2 and defines the rod side chamber R1 and the piston side chamber R2 in the inner cylinder 1, and the damper is a uniflow type. Therefore, there is a so-called pressure side passage (not shown) that allows the hydraulic oil from the piston side chamber R2 to flow into the rod side chamber R1, but the piston of the hydraulic oil from the rod side chamber R1 is reversed. There is no so-called extension side passage allowing the outflow to the side chamber R2.

  The piston body 3 has an extension side check valve (not shown) so as to close the downstream end of the pressure side passage so as to be openable from the rod side chamber R1, and this extension side check valve. Allows the hydraulic oil from the piston side chamber R2 to flow into the rod side chamber R1, but prevents the reverse flow of the hydraulic oil from the rod side chamber R1 to the piston side chamber R2.

  The outer cylinder 4 is disposed outside the inner cylinder 1 and defines a reservoir R between the outer cylinder 4 and the head side end which is the left end portion in the figure like the inner cylinder 1. It consists of the cylinder which has the part 4a and the bottom side edge part 4b used as a right side edge part in a figure.

  In the outer cylinder 4, the head side end portion 4a is thinned so as to cut the inner peripheral side of the head side end portion 4a, thereby making it easy to improve the sealing performance of a seal 6f described later. ing.

  On the other hand, in the outer cylinder 4, as shown in the drawing, the bottom side end portion 4b has a thin-walled structure in the same manner as the head side end portion 4a, so that the sealing performance of a seal 41a described later is easily improved.

  That is, according to the assembly procedure of the damper, the head member 6 and the bottom member 8 are integrated with the inner cylinder 1 when the outer cylinder 4 is positioned at a predetermined position.

  From this, when the head side end 4a of the outer cylinder 4 is positioned on the outer periphery of the head member 6, the outer diameter of the bottom member 8 is such that the head side end 4a and the bottom side end 4b of the outer cylinder 4 It is important that it is set smaller than the inner diameter of a so-called main body (not shown).

  And since the outer diameter of the bottom member 8 is set smaller than the inner diameter in the main-body part of the outer cylinder 4, a cylindrical clearance gap (not shown) appears between both.

  In view of this, in order to fill the gap appearing in the above-described cylindrical shape, a spacer 41 formed in a cylindrical shape corresponding to the shape of the gap is inserted between the two. The connection to the outer periphery of the bottom member 8 in the bottom side end part 4b of the cylinder 4 is enabled.

  At this time, a seal 41 a is wound around the outer periphery of the spacer 41 to ensure liquid tightness between the spacer 41 and the bottom side end portion 4 b of the outer cylinder 4.

  Incidentally, in the outer cylinder 4, the head side end portion 4 a is adjacent to the outer periphery of the head member 6, and the bottom side end portion 4 b is adjacent to the outer periphery of the spacer 41 constituting the outer periphery of the bottom member 8. Therefore, in order to prevent displacement of the outer cylinder 4 from a predetermined position as an arrangement position of the outer cylinder 4, the outer cylinder 4 is fixedly connected to the bottom member 8 by a bolt 42 which is a fixing means that also penetrates the spacer 41. Is done.

By the way, the above-mentioned spacer 41 replaces the arrangement of the spacer 41 by filling the gap that appears between the outer periphery of the bottom member 8 and the inner periphery of the bottom-side end portion 4b of the outer cylinder 4. Although not shown, the inner circumference of the bottom side end 4b of the outer cylinder 4 may bulge inward to form a reduced diameter portion that matches the inner diameter with the outer diameter of the bottom member 8. This is advantageous in that the part that is the spacer 41 is unnecessary.

  Since the damper is set to a uniflow type, the base valve portion 5 is set to have no valve as a damping element, similar to the piston body 3 described above.

  And in this base valve part 5, about fixing this base valve part 5 inside the bottom side of the inner cylinder 1 which is a predetermined position, the snap ring 51 fitted to the outer periphery is fixed to the head side in the inner cylinder 1. By engaging with a step (not shown) formed on the inner periphery of the end portion 1b, the base valve portion 5 is prevented from being caught in the inner cylinder 1.

  In addition, the base valve portion 5 has a so-called expansion-side passage (not shown) that allows the hydraulic oil from the reservoir R to flow into the piston-side chamber R2 in the inner cylinder 1. There is no so-called pressure side passage allowing the hydraulic oil to flow out from the piston side chamber R2 to the reservoir R.

  The base valve portion 5 has a pressure side check valve (not shown) so as to releasably close the downstream end of the expansion side passage from the piston side chamber R2, and this pressure side check valve. Allows the hydraulic oil from the reservoir R to flow into the piston-side chamber R2, but prevents the hydraulic oil from flowing into the reservoir R from the piston-side chamber R2 which is the reverse.

  By the way, in this base valve portion 5, as shown in the drawing, the rear portion of the base valve portion 5, that is, the portion communicating with the reservoir R is a chamber R 3 formed of a recessed portion formed in the bottom member 8, The container chamber R3 communicates with the reservoir R through a communication hole 8b formed in the bottom member 8 in the same manner.

  The head member 6 constitutes a so-called cylinder head in the damper, and the rod body 2 is passed through the shaft core portion under the arrangement of the bush 6a and the check seal 6b.

  At this time, in the damper shown in FIG. 2 described above, the portion corresponding to the head member 6 in the present invention is formed in a divided structure consisting of two parts, the head member (6) and the connecting member (7). This is due to welding (M) the outer cylinder (4) to the connecting member (7) and the bottom member (8) on the head member (6) side.

  On the other hand, in the present invention, as is the case with the bottom member 8, the outer cylinder 4 is not welded to the head member 6. This is advantageous in that the number can be reduced.

  The head member 6 closes the head side end of the inner cylinder 1 and closes the head side end of the outer cylinder 4 as shown in the figure. The insertion portion 6 c is inserted between the head side end 1 a of the inner cylinder 1 and the head side end 4 a of the outer cylinder 4 to ensure concentricity between the inner cylinder 1 and the outer cylinder 4.

  Further, the head member 6 has an inner peripheral thread 6d on the inner periphery of the insertion portion 6c, and the inner peripheral thread 6d is provided on the outer periphery of the head side end 1a of the inner cylinder 1. The formed outer peripheral thread 1 c is screwed to realize the connection of the inner cylinder 1 to the head member 6.

  Further, the head member 6 has a seal 6e on the inner periphery of the insertion portion 6c, ensures liquid-tightness with the inner cylinder 1, and has a seal 6f on the outer periphery. The liquid tightness with the outer cylinder 4 is ensured.

  Further, the head member 6 has a seal 6g whose inner periphery is in sliding contact with the outer periphery of the rod body 2 at the head end, which is the left end in the figure, and is attached to the outer periphery of the rod body by the seal 6g. The intrusion of dust from the inside and the leakage of hydraulic oil constituting the oil film from the inside are prevented.

  Incidentally, as shown in the figure, the head member 6 has a lifting tool F, and the damper can be lifted by using the lifting tool F.

  By the way, since the damper shown in figure is utilized for the seismic isolation apparatus and damping device about a structure as mentioned above, it is set as the setting which makes the damping action the same at the time of expansion-contraction operation.

  Therefore, in order to realize this, the damper is set to be a uniflow type, and a predetermined damping action is realized by a single damping part. For this reason, this damping part is disposed on the head member 6, and The damping unit can be controlled to realize an optimum damping action.

  That is, in the damper shown in the figure, the head member 6 has a so-called external control valve V, and the generated damping force can be raised or lowered by a predetermined operation on the control valve V. This control valve V is shown in detail in the figure. However, it has a control part arrange | positioned in the drain channel | path which connects the rod side chamber R1 in the inner cylinder 1, and the reservoir | reserver R.

  The control unit is connected to an operation unit V1 projecting from the outer surface of the head member 6. The operation unit V1 enables rotation of an adjuster (not shown) by manual operation. In the case of V, the flow resistance in the working fluid that passes through the control unit is changed by the rotation of the adjuster, thereby realizing the optimum damping action by the damping unit.

  The bottom member 8 constitutes a so-called bottom of the damper, and in the drawing, the bottom member 8 closes the bottom side end of the inner tube 1 and closes the bottom side end of the outer tube 4. The protruding portion 8c is inserted into the bottom end 1b of the inner cylinder 1.

  And in this bottom member 8, the outer periphery thread 8a formed in the bottom member 8 mentioned above is formed in the outer periphery of the protrusion part 8c, and the bottom side edge part 1b in the inner cylinder 1 mentioned above is formed in this outer periphery thread 8a. The inner peripheral thread 1d formed is screwed onto the inner periphery.

  Further, in the bottom member 8, the above-described communication hole communicating with the chamber R3 is formed by forming the above-described chamber R3 so that the shaft core portion of the protruding portion 8c is recessed from the base valve 5 side. Open 8b.

  By the way, as described above, in the drawing, it is not considered that the outer diameter of the bottom member 8 coincides with the outer diameter of the head member 6. Therefore, the inner periphery of the spacer 41 is the outer periphery of the bottom member 8. Adjacent.

  Therefore, as illustrated, the bottom member 8 has a seal 8d on the outer periphery, and the seal 8d ensures liquid tightness between the bottom member 8 and the spacer 41.

  As described above, the damper according to the present invention basically includes the inner cylinder 1, the rod body 2, the piston body 3, the outer cylinder 4, the base valve portion 5, the head member 6, and the bottom member 8. Thus, the intended purpose can be achieved. However, in the place shown in the drawing, the following consideration is given because the damper is formed in a uniflow type.

  That is, first, when this damper is used in a seismic isolation device or a vibration control device for a structure, the inner cylinder 1 side, that is, the so-called cylinder tube side is connected to a fixed side such as the ground side, or the structure side. Even if it is connected to the movable side, it does not rotate around the rod body 2, so that a so-called top and bottom can be set on the cylinder tube side in the damper arranged horizontally.

  Since the top and bottom can be set on the cylinder tube side, for example, in the bottom member 8 in which the base valve portion 5 is provided next to, the communication hole for communicating the chamber R3 on the back side of the base valve portion 5 with the reservoir R. It is sufficient to open 8b on the so-called lower surface side of the protruding portion 8c.

  As a result, in the protruding portion 8c, it is not necessary to open the communication hole 8b on the so-called upper surface side which is the opposite side, and therefore it is easy to ensure the mechanical strength of the bottom member 8 having the protruding portion 8c. .

  Next, in this damper, it is assumed that the hydraulic oil from the rod side chamber R1 in the inner cylinder 1 flows into the reservoir R through a drain passage (not shown) opened in the head member 6 and the control valve V during the expansion / contraction operation. However, at this time, when the damper is not completely horizontal, for example, when the rod body 2 is positioned obliquely so as to be positioned higher than the cylinder tube side, the lower surface side of the head member 6 is placed on the reservoir R. May be exposed from the hydraulic fluid in the tank.

  Under the condition that the lower surface side of the head member 6 is exposed from the hydraulic oil in the reservoir R, it is in the drain passage formed in the head member 6, that is, in the drain passage communicating with the rod side chamber R1 in the inner cylinder 1. When the hydraulic oil flowing out from the control valve V has a momentum, the hydraulic fluid is ejected to the reservoir R, which causes a problem that air is easily mixed into the hydraulic oil.

  Therefore, in the present invention, the pipe P is connected to the insertion portion 6c of the head member 6 and the drain passage is communicated with the pipe P. The drain communication passage is opened to the lower surface side. In addition, the opening at the lower end, which is the right end in the drawing of the pipe P, is positioned as far as possible in the reservoir R on the so-called bottom side of the damper.

  As a result, even when the damper is disposed obliquely as described above, the working oil from the inner cylinder 1 enters the reservoir R in an air chamber (not shown) defined by an oil surface (not shown) as a boundary. It is no longer ejected and the chance of air entering the hydraulic oil can be greatly reduced.

  Incidentally, the position of the drain communication path can be adjusted by the rotation of the threaded portion, and it can be fixed by using the lock nut 11 at a predetermined position.

  Although not shown, it is preferable that the pipe P has a plurality of pipes. For this reason, the pipe member P has a communication passage 6h formed in an annular shape in the head member 6, and each of the pipes having a plurality of pipes in the communication passage 6h. The so-called proximal end of P is connected.

  In this damper formed as described above, the rod side chamber R1 contracts because the piston body 3 is in the inner cylinder 1 at the time of extension operation and the piston body 3 moves leftward in the drawing, so that the hydraulic oil flows into the drain passage and the control valve. It flows out to the reservoir R through V.

  At this time, the working oil from the reservoir R flows into the expanding piston side chamber R2 through the base valve portion 5 to prevent so-called negative pressure generation due to insufficient suction of the working oil.

  On the other hand, in the damper, the rod side chamber R1 expands and the piston side chamber R2 contracts because the piston body 3 moves rightward in the drawing in the inner cylinder 1 during the contraction operation.

  Accordingly, the hydraulic oil from the piston side chamber R2 passes through the piston body 3 and flows into the rod side chamber R1, but at this time, an amount of hydraulic oil corresponding to the so-called rod intrusion volume integral becomes excessive in the piston side chamber R2. Therefore, this excessive amount of hydraulic oil also flows into the rod side chamber R1 and flows out to the reservoir R through the drain passage and the control valve V.

  As a result, in this damper, the same amount of hydraulic oil passes through the control valve V during expansion and contraction operation, so that the same damping action is realized in both directions. Therefore, the level of the generated damping force can be adjusted by an external operation.

  In the damper, the inner cylinder 1 filled with hydraulic oil has the head-side end 1a screwed to the head member 6 under the liquid-tight structure and the bottom-side end 1b is liquid-tight to the bottom member 8. Since it is screwed down, leakage of the hydraulic oil from the rod side chamber R1 and the piston side chamber R2 in the inner cylinder 1 to the outside of the inner cylinder 1 can be prevented, so that the rod side chamber R1 and the piston side chamber R2 are brought to a necessary pressure state. It is possible to maintain the damping action by the damping part as set.

  In this damper, since the hydraulic oil in the inner cylinder 1 does not leak out of the inner cylinder 1, the operation of the damping portion is ensured in the reservoir R defined between the inner cylinder 1 and the outer cylinder 4. It is sufficient to generate a so-called tank function without burdening the fluid pressure, and since the configuration for connecting the outer cylinder 4 to the head member 6 and the bottom member 8 can be simplified, workability during assembly is improved. Can be improved.

  In the damper, the head side end 4a is adjacent to the head member 6 while the bottom side end 4b of the outer cylinder 4 is adjacent to the bottom member 8, while the bottom side end 4b is Since it is connected to the bottom member 8 under the arrangement of the bolts 42 serving as fixing means, compared to the case of being connected by welding as in the technique disclosed in Patent Document 1, the outer cylinder 4 is caused by welding. There is no need to generate distortion, and there is no need to worry about variations in the finished length of the outer cylinder 4 with respect to the set length of the inner cylinder 1.

  As a result, according to this damper, it is possible to prevent variations in the finished length of the outer cylinder 4 with respect to the set length of the inner cylinder 1, so that no post-processing such as post-processing of the head member 6 is required. Improves versatility by preventing backlash and preventing hydraulic fluid from leaking or fluid pressure from being released, improving workability during assembly and reducing product costs. Can be expected.

  For example, it is suitable for use in seismic isolation devices and vibration control devices for structures, and is suitable for suppressing shaking in structures resulting from earthquakes.

DESCRIPTION OF SYMBOLS 1 Inner cylinder 1a, 4a Head side edge part 1b, 4b Bottom side edge part 1c, 8a Outer periphery thread 1d, 6d Inner thread 2 Rod body 3 Piston body 4 Outer cylinder 5 Base valve part 6 Head member 6a Bush 6b Check Seal 6c Insertion part 6e, 6f, 6g, 8d Seal 8 Bottom member 8b Communication hole 8c Projection part 11 Lock nut 12 Snap ring 41 Spacer 42 Fixing bolt 51 Snap ring F Suspension tool P Pipe R Reservoir R1 Rod side chamber R2 Piston Side chamber R3 volume chamber V control valve

Claims (6)

An inner cylinder filled with working fluid;
A rod body whose tip side is inserted into the inner cylinder so as to be capable of appearing and retracting;
A piston body that is held at the tip of the rod body and is slidably accommodated in the inner cylinder while defining a rod side chamber and a piston side chamber in the inner cylinder;
An outer cylinder disposed outside the inner cylinder and defining a reservoir with the inner cylinder;
A base valve portion disposed inside the bottom side of the inner cylinder,
A head member that closes the head side end of the outer cylinder and the head side end of the inner cylinder while passing the rod body through the shaft core;
While fixing the base valve portion has a bottom member closing a bottom end at the bottom end and above of the inner tube in the outer tube,
In the damper that performs a predetermined damping action in the damping portion during the expansion and contraction operation in which the rod body appears and disappears with respect to the inner cylinder,
The bottom-side end portion is screwed under liquid-tight structure in the bottom member of the causes is screwed the head-side end of the inner cylinder under liquid-tight structure in the head member of the above,
The head-side end of the outer tube adjacent to the distribution設下the seal head members described above,
The outer diameter of the bottom member is formed to be smaller than the inner diameter of the bottom end of the outer cylinder, and a spacer with a seal wound is inserted into the gap between the bottom member and the bottom end. Let
Further, the damper is characterized in that the bottom side end portion of the outer cylinder and the spacer are connected to the bottom member under the arrangement of the fixing means. An inner cylinder filled with working fluid;
A rod body whose tip side is inserted into the inner cylinder so as to be capable of appearing and retracting;
A piston body that is held at the tip of the rod body and is slidably accommodated in the inner cylinder while defining a rod side chamber and a piston side chamber in the inner cylinder;
An outer cylinder disposed outside the inner cylinder and defining a reservoir with the inner cylinder;
A base valve portion disposed inside the bottom side of the inner cylinder,
A head member that closes the head side end of the outer cylinder and the head side end of the inner cylinder while passing the rod body through the shaft core;
A bottom member that closes the bottom side end of the outer cylinder and the bottom side end of the inner cylinder while fixing the base valve portion;
In the damper that performs a predetermined damping action in the damping portion during the expansion and contraction operation in which the rod body appears and disappears with respect to the inner cylinder,
The head-side end of the inner cylinder is screwed to the head member under a liquid-tight structure and the bottom-side end is screwed to the bottom member under a liquid-tight structure,
The outer diameter of the bottom member is formed to be smaller than the inner diameter of the bottom side end portion of the outer cylinder, and the reduced diameter has an inner diameter that matches the outer diameter of the bottom member at the bottom side end portion of the outer cylinder. Forming part,

The head side end of the outer cylinder is adjacent to the head member under the arrangement of the seal,
The bottom side end of the outer cylinder is adjacent to the bottom of the seal while the reduced diameter portion is in contact with the outer periphery of the bottom member,
A damper characterized in that a bottom side end portion of the outer cylinder is connected to the bottom member under a fixing means . The outer peripheral thread which the head side end portion of the inner cylinder has on the outer periphery is coupled to the head member by screwing with the inner peripheral thread which the head member has, and the lock nut screwed to the outer peripheral thread is connected to the head. The damper according to claim 1 or 2 , wherein a connection state of the inner cylinder to the head member is fixed by being in close contact with the end surface of the member . The side part where the base valve part is opposed to the inside of the inner cylinder is located under the liquid-tight structure in the inner cylinder, and the snap ring fitted to the outer periphery of the side part communicating with the reservoir is formed at the bottom side end part of the inner cylinder. The damper according to claim 1, 2 or 3 , wherein the damper is fixed to a predetermined position by being locked to a step formed on the inner periphery . The piston body has an extension-side check valve that allows the working fluid from the piston-side chamber in the inner cylinder to flow into the rod-side chamber but prevents the hydraulic oil from flowing from the rod-side chamber to the piston-side chamber. The valve portion includes a pressure side check valve that allows the working fluid from the reservoir to flow into the piston side chamber, but prevents the hydraulic oil from flowing from the piston side chamber to the reservoir. Or the damper of 4 . A damping part is provided on the above-mentioned head member in an external manner to allow the working fluid to flow out from the rod side chamber in the inner cylinder to the reservoir, but acts as a damping while preventing the reverse flow, and from the outside The damper according to claim 1, 2, 3, 4 or 5, wherein the generated damping force can be adjusted by the above operation .

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