JP2007205401A - Damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a damper having high degree of freedom of changing damping force besides obtaining damping force in response to an actual running state. <P>SOLUTION: The damper is equipped with a first damping member 10 for damping external force input in an input part and a second damping member 20 which movably contains the first damping member 10 and damps external force input in the first damping member 10. The first damping member 10 includes a first cylinder 11 and a piston 12 for the first cylinder for partitioning the inside of the first cylinder 10 into at least two fluid chambers. The second damping member 20 contains a second cylinder 21 slidably includes the first cylinder 11. The first cylinder 11 functions as a piston for a second cylinder 21 in the second damping member 20. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an attenuation device.

2. Description of the Related Art Conventionally, in a vehicle such as an automobile, an attenuation device is used to support a vehicle body and a wheel with appropriate rigidity and prevent an impact applied to the wheel from being transmitted to the vehicle body.
The damping device generally includes a cylinder filled with a viscous fluid, a piston that slides within the cylinder, and a piston rod that is coupled to the piston, and the viscous fluid is divided into a plurality of fluid chambers by the movement of the piston. It has a structure that moves between them. As a configuration for this purpose, a passage for viscous fluid is formed in the piston, and viscous resistance or the like when the viscous fluid passes through this passage is obtained as a damping force.

In addition, a damping device is disclosed in which a check valve is provided in the above-described passage, and a spring that biases the check valve toward the closing side as the stroke on the extension side increases (see, for example, Patent Document 1). .
In this damping device, when the stroke on the extension side increases, the pressing force of the spring is weakened, and the flow resistance of the viscous fluid passing through the check valve is lowered. As a result, the damping force based on the flow resistance decreases as the stroke on the extension side increases.
JP-A-61-88035

  By the way, in order to improve the running performance during rolling of the vehicle, it is necessary to increase the damping force and set the suspension to be hard. However, with such a hard suspension setting, the ride feeling during normal driving may be reduced, so a damping device that satisfies both of these conditions, that is, the shock absorption characteristics with a soft stroke during normal driving of the vehicle. In addition, it is desired to develop a damping device that enables a hard shock absorption characteristic when rolling a vehicle.

  In addition, in the conventional damping device, the damping force is configured to decrease with the stroke on the extension side. However, since the decrease in the damping force is due to a change in the pressing force of the spring, the damping force is reduced. The change was unambiguous and the degree of freedom in changing the damping force was low.

  Therefore, an object of the present invention is to provide a damping device that can obtain a damping force corresponding to a traveling state and has a high degree of freedom in varying the damping force.

  The damping device according to claim 1 of the present invention that has solved the above problems includes an input unit to which an external force is input, a first damping member that attenuates the external force input to the input unit, and the first damping member. A second damping member that is movably included and attenuates an external force input to the first damping member.

  According to the first aspect of the present invention, a double-structured damping device in which the first damping member is included in the second damping member is obtained, and the external force input to the input unit is attenuated by these two damping members. be able to. Accordingly, for example, the external force input to the input unit can be configured to be attenuated by the second attenuation member after being attenuated by the first attenuation member, and the external force that is not attenuated by the first attenuation member is It is possible to realize stepwise attenuation in which attenuation is performed by the two attenuation members. Accordingly, for example, during normal driving of the vehicle, it is possible to set the damping force to be soft by the first damping member so as to obtain a soft shock absorption characteristic. Also, when the vehicle is rolled, the damping is performed by the second damping member. It is possible to set the force so as to obtain a hard shock absorption characteristic. Therefore, a damping device having a high degree of freedom in varying the damping force can be obtained.

  According to a second aspect of the present invention, in the damping device according to the first aspect, the first damping member is provided slidably in the first cylinder filled with the viscous fluid, and in the first cylinder, A first cylinder piston that divides the inside of the first cylinder into at least two fluid chambers, and the second damping member is filled with a viscous fluid and slidably includes the first cylinder. The input portion is connected to the first cylinder piston of the first damping member, and the first cylinder of the first damping member is a second damping member in the second damping member. It is the structure which functions as a 2 cylinder piston.

According to the second aspect of the present invention, the first cylinder is included in the second cylinder, and the first cylinder functions as a piston of the second cylinder. The external force obtained and input to the input unit can be attenuated by the action in these two cylinders. Accordingly, for example, the external force input to the input unit can be configured to be attenuated in the second cylinder after being attenuated in the first cylinder, and the external force that has not been attenuated in the first cylinder is It is possible to realize stepwise attenuation in which attenuation occurs in two cylinders.
In addition, since the first cylinder functions as the piston of the second cylinder and the number of parts can be reduced by that amount, the first cylinder is included in the second cylinder and the structure is simple. be able to.

  The stroke for reducing the damping force in the damping device is due to the sliding of the first cylinder piston in the first cylinder and the sliding of the first cylinder itself in the second cylinder. As a result, a stroke for reducing the damping force can be ensured without increasing the overall length of the damping device, and a compact damping device with excellent damping capability can be obtained. In addition, the degree of freedom of variable damping force increases.

  According to a third aspect of the present invention, in the damping device according to the first or second aspect, the first cylinder and the second cylinder are configured to have different damping characteristics. .

  According to the third aspect of the present invention, since the first cylinder and the second cylinder are configured to have different damping characteristics, for example, the input from the outside is attenuated by the first cylinder as described above. After that, it can be set so as to be attenuated by the second cylinder, and the region in which the damping force can be varied can be freely set.

  A fourth aspect of the present invention is the damping device according to the second or third aspect, wherein the first cylinder is an elastic member that expands and contracts in the sliding direction of the first cylinder. It is held in position.

  According to the fourth aspect of the invention, since the first cylinder is held in a predetermined position in the second cylinder by the elastic member, the return to the predetermined position after receiving an external force is excellent and stable. Damping force characteristics can be obtained. Moreover, smooth sliding of the 1st cylinder as a piston is realizable by expansion-contraction of an elastic member. Further, when the first cylinder strokes in small increments, the vibration absorption is improved and the riding feeling is improved.

  ADVANTAGE OF THE INVENTION According to this invention, the damping force corresponding to the state at the time of driving | running | working can be obtained, and also the damping device with a high freedom degree of variable damping force is obtained.

  Hereinafter, with reference to the drawings, details of an attenuation device according to an embodiment of the present invention will be described. In the present embodiment, a damping device applied to a left and right front wheel strut suspension system will be described. In addition, since the thing of the same structure is applied to right and left as an attenuation device, below, the attenuation device applied to the right front wheel which is one side is explained, and about the word which shows directionality, for example, the word "up and down" Based on the state where the damping device is attached to the right front wheel.

  In the drawings to be referred to, FIG. 1 is a rear view of a structure around a right front wheel for explaining an attenuation device according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view for explaining the installation state. 3 is an enlarged cross-sectional view of an attenuation device according to an embodiment of the present invention, and FIG. 4 is a schematic cross-sectional view.

First, the structure around the right front wheel to which the damping device of the present embodiment is applied will be described with reference to FIGS. 1 and 2. 1 and 2, the cover 5 (see FIG. 3) described later is omitted from the illustration.
A strut type suspension device 30 to which the damping device 1 is applied includes a coil spring 31 and stands along a caster angle. The damping device 1 is built in and a top strut mount 32 is fixed to a vehicle body (not shown). The lower end portion of the damping device 1 is fixed to a knuckle 34 via a connecting member 33, and this knuckle 34 is supported by a lower arm LA that is swingably connected to a vehicle body (not shown). Further, a bearing portion (not shown) is assembled to the knuckle 34, and a drive shaft DS supported by the bearing portion is connected to the hub H. The knuckle 34 is connected to a tie rod T from a steering device (not shown).

As shown in FIGS. 3 and 4, the damping device 1 mainly includes a cylinder tube 2 and a piston rod 3 that reciprocates relative to the cylinder tube 2 and serves as an input portion for external force.
The cylinder tube 2 includes a first damping member 10 and a second damping member 20, and has a double structure in which the first damping member 10 is included in the second damping member 20 so as to be movable. In the present embodiment, the external force input to the piston rod 3 is first attenuated by the first damping member 10, and the external force input to the first damping member 10 (external force that has not been attenuated by the first damping member 10). Is attenuated by the second damping member 20.

As a configuration for that purpose, the first damping member 10 is provided in a first cylinder 11 and slidably provided in the first cylinder 11, and the first cylinder 11 is divided into two fluid chambers A1 and A2. And a cylinder piston 12.
As shown in FIG. 3, the first cylinder 11 is a double tube comprising an outer cylinder 11a and an inner cylinder 11b. The outer cylinder 11a and the inner cylinder 11b are concentrically coupled by a rib or the like (not shown). A fluid chamber A3 (hereinafter referred to as a first reservoir chamber A3) is formed between the outer cylinder 11a and the inner cylinder 11b. Such a first cylinder 11 is filled with oil as a viscous fluid.

  The first cylinder piston 12 divides the inside of the inner cylinder 11b into the fluid chamber A1 in which the piston rod 3 is not accommodated and the fluid chamber A2 in which the piston rod 3 is accommodated. A pressure side passage 12a and an extension side passage 12b are provided. The pressure side passage 12a is opened and closed by a check valve (not shown), and the extension side passage 12b is opened and closed by a disc valve (not shown).

  As a result, during compression, the oil in the fluid chamber A1 passes through the pressure side passage 12a, deforms and opens a check valve (not shown), and is guided to the fluid chamber A2. As a result, a compression side damping force is generated. Further, at the time of extension, the oil in the fluid chamber A2 passes through the extension side passage 12b, deforms and opens a disc valve (not shown), and is guided to the fluid chamber A1. Thereby, the extension side damping force is generated.

A first bottom valve 13 that partitions the fluid chamber A1 and the first reservoir chamber A3 of the inner cylinder 11b is provided at the lower portion of the first cylinder 11. A bolt 13a is inserted into the first bottom valve 13, and a disk valve, a check valve 13c, etc. (not shown) are interposed between the bolt 13a and the nut 13b.
In such a first bottom valve 13, when the first cylinder 11 is compressed, oil corresponding to the volume of the piston rod 3 entering the inner cylinder 11 b deforms a disk valve (not shown) from the opening of the check valve 13 c through the passage 13 d. Then, oil is pushed out from the fluid chamber A1 to the first reservoir chamber A3 to obtain a compression side damping force. Further, when extending, the oil corresponding to the retracted volume of the piston rod 3 that retracts from the inner cylinder 11b pushes open the check valve 13c and is replenished from the first reservoir chamber A3 to the fluid chamber A1, thereby obtaining an expansion-side damping force.

  The first reservoir chamber A3 is divided into a gas chamber G (see FIG. 4) and an oil chamber, and the gas chamber G is compressed by the oil pushed into the first reservoir chamber A3 when the first cylinder 11 is compressed. It has come to be. Further, at the time of compression, the compression limit (contracted state) in the first cylinder 11 is set so that the lower end portion of the piston rod 3 does not contact the upper end portion of the first bottom valve 13.

The piston rod 3 is provided with a first cylinder rebound rubber 3b via a bracket 3a. The first cylinder rebound rubber 3b has a ring shape and abuts against a shaft seal portion 11c provided on the upper portion of the inner cylinder 11b of the first cylinder 11 at the time of extension. The movement is regulated.
Further, sub bump stop rubbers 3c and 3c are provided at the lower end portion of the piston rod 3 and the upper end portion of the first bottom valve 13, respectively, as a fail-safe function during compression.

The second damping member 20 is configured to include a second cylinder 21 that is filled with oil as a viscous fluid and slidably includes the first cylinder 11. In the present embodiment, the first cylinder 11 functions as a piston of the second cylinder 21, and the bottom spring 24 as an elastic member that expands and contracts in the sliding direction of the first cylinder 11 is used in the second cylinder 21. Is held at a predetermined position.
A second cylinder piston 22 is provided on the outer peripheral surface of the first cylinder 11, and the second cylinder piston 22 divides the second cylinder 21 into two fluid chambers B1 and B2. .
Further, in the second cylinder 21, the oil filled therein has a higher viscosity than the oil filled in the first cylinder 11. Thereby, when there is an external input, the attenuation characteristic is set so that the input is attenuated by the first cylinder 11 and then attenuated by the second cylinder 21.

  Similar to the first cylinder 11, the second cylinder 21 is a double tube comprising an outer cylinder 21a and an inner cylinder 21b. The outer cylinder 21a and the inner cylinder 21b are concentrically formed by a rib or the like (not shown). The fluid chamber B3 (hereinafter referred to as the second reservoir chamber B3) is formed between the outer cylinder 21a and the inner cylinder 21b.

  The second cylinder piston 22 partitions the inside of the inner cylinder 21b into the fluid chamber B1 in which the piston rod 3 is not accommodated and the fluid chamber B2 in which the piston rod 3 is accommodated. A pressure side passage 22a and an extension side passage 22b are provided. The pressure side passage 22a is opened and closed by a check valve (not shown), and the extension side passage 22b is opened and closed by a disc valve (not shown).

Thereby, at the time of compression, the oil in the fluid chamber B1 passes through the pressure side passage 22a, deforms and opens a check valve (not shown), and is guided to the fluid chamber B2. As a result, a compression side damping force is generated. At the time of extension, the oil in the fluid chamber B2 passes through the extension side passage 22b, deforms and opens a disk valve (not shown), and is guided to the fluid chamber B1 to generate an extension side damping force.
A bearing 25 is provided on the inner wall of the second cylinder 21 in order to smoothly perform the reciprocating motion of the first cylinder 11 in the second cylinder 21.

A second bottom valve 23 that partitions the fluid chamber B1 and the second reservoir chamber B3 of the inner cylinder 21b is provided below the second cylinder 21. A bolt 23a is inserted into the second bottom valve 23, and a disk valve, a check valve 23c and the like (not shown) are interposed between the bolt 23a and the nut 23b.
In such a second bottom valve 23, when the second cylinder 21 is compressed, oil corresponding to the intrusion volume of the piston rod 3 entering the inner cylinder 21 b deforms a disk valve (not shown) from the opening of the check valve 23 c through the passage 23 d. Then, oil is pushed out from the fluid chamber B1 to the second reservoir chamber B3 to obtain a compression side damping force. Further, when extending, the oil corresponding to the retracted volume of the piston rod 3 retracting from the inner cylinder 21b pushes open the check valve 23c, and is replenished from the second reservoir chamber B3 to the fluid chamber B1, thereby obtaining an expansion-side damping force.

  The second reservoir chamber B3 is divided into a gas chamber G (see FIG. 4) and an oil chamber, and the gas chamber G is compressed by the oil pushed into the second reservoir chamber B3 when the second cylinder 21 compresses. It has come to be.

In addition, a second cylinder rebound rubber 26 is provided on the upper portion of the first cylinder 11.
Further, a bump stop rubber 4 is provided around the piston rod 3 below the spring seat 32 a below the strut mount 32. The upper portion of the cylinder tube 2 is covered with an outer cover 5.

Next, the operation of the damping device 1 of the present embodiment will be described mainly with reference to FIGS. For easy understanding, as shown in FIGS. 5A and 6A, in the initial state (normal state), the first cylinder piston 12 is positioned at a predetermined position in the first cylinder 11. In addition, it is assumed that the first cylinder 11 is held at a predetermined position by the bottom spring 24 in the second cylinder 21.
When a vehicle (not shown) travels and the tire 40 (see FIG. 1) moves up and down due to road surface unevenness and acceleration / deceleration, in the damping device 1, the piston rod 3 moves up and down relative to the cylinder tube 2.

First, the bump stroke (compression) will be described. At the time of compression, the piston rod 3 enters the first cylinder 11 as shown in FIG. As a result, the oil in the fluid chamber A1 passes through the pressure side passage 12a (see FIG. 3), deforms and opens a check valve (not shown), and is guided to the fluid chamber A2. Thereby, a compression side damping force is generated.
Thus, at the time of compression, the piston rod 3 first enters the first cylinder 11, as described above, because the viscosity of the oil in the second cylinder 21 is greater than the viscosity of the oil in the first cylinder 11. This is because it is set to be large and the holding force by the bottom spring 24 acts on the first cylinder 11. That is, since the oil filled in the second cylinder 21 has a higher viscosity than the oil filled in the first cylinder 11, when an external force from the piston rod 3 is input, When the external force is attenuated in the first cylinder 11 and then the external force is applied to the first cylinder 11, the first cylinder 11 is moved in the second cylinder 21. It acts so that the external force applied to is attenuated. As a result, a large external force that has not been attenuated in the first cylinder 11 is attenuated in the second cylinder 21 step by step.

  When the piston rod 3 enters the first cylinder 11, the oil corresponding to the intrusion volume of the piston rod 3 that enters the inner cylinder 11b (see FIG. 3) becomes the check valve 13c (see FIG. 3) of the first bottom valve 13. ) Through the fluid chamber A1 to the first reservoir chamber A3. At this time, a damping force is generated by the flow resistance when passing through the passage 13d (see FIG. 3).

After that, as shown in FIG. 5B, when the piston rod 3 moves to the compression side and reaches the compression limit state in the first cylinder 11, the movement of the piston rod 3 in the compression direction in the first cylinder 11 is restricted. Is done.
If an external force in the compression direction continues to act on the piston rod 3 from this state, the first cylinder 11 moves down in the second cylinder 21 against the spring force of the bottom spring 24, and as a result, in the second cylinder 21. The piston rod 3 further enters (see FIG. 5C).

  At this time, when the first cylinder 11 moves down in the second cylinder 21, the oil in the fluid chamber B1 passes through the pressure side passage 22a (see FIG. 3), deforms and opens a check valve (not shown), and opens the fluid chamber B2. Led to. Thereby, a thick damping force is generated in the second cylinder 21. In addition, the oil corresponding to the intrusion volume of the piston rod 3 entering the inner cylinder 21b (see FIG. 3) deforms a disk valve (not shown) from the opening of the check valve 23c (see FIG. 3) through the passage 23d (see FIG. 3). To open and push oil from the fluid chamber B1 to the second reservoir chamber B3. At this time, a damping force is generated by the flow resistance when passing through the passage 23d.

  Here, when the piston rod 3 moves to the compression side after the movement to the compression side, the operation reverse to the above-described operation, that is, from the state shown in FIG. In the second cylinder 21, the first cylinder 11 is returned to the extension side by the spring force of the bottom spring 24 so that the state shown in FIG. 5B is obtained, and then the state shown in FIG. ), The piston rod 3 is returned to the extending side.

  Next, at the time of the rebound stroke (extension), as shown in FIG. 6B, the piston rod 3 moves to the extension side and retreats from the first cylinder 11, so that the oil in the fluid chamber A2 is discharged. The disc valve (not shown) is deformed and opened through the extension side passage 12b (see FIG. 3). As a result, the oil in the fluid chamber A2 is guided to the fluid chamber A1 to generate an extension side damping force.

  At this time, since the oil corresponding to the retraction volume of the piston rod 3 retreating from the inner cylinder 11b (see FIG. 3) is insufficient in the fluid chamber A1, through the check valve 13c (see FIG. 3) of the first bottom valve 13, Oil is supplied from the first reservoir chamber A3 to the fluid chamber A1, and a damping force is generated due to the flow resistance when passing through the passage 13d.

As shown in FIG. 6B, the piston rod 3 moves to the extension side, and the first cylinder rebound rubber 3b (see FIG. 3) contacts the shaft seal portion 11c of the first cylinder 11 (see FIG. 3). If it will be in a state, the movement to the expansion | extension side of the piston rod 3 in the 1st cylinder 11 will be controlled.
When the piston rod 3 continues to move to the extension side due to external force from this state, the first cylinder 11 moves up in the second cylinder 21 against the urging force of the bottom spring 24. As a result, the second cylinder 21 The piston rod 3 withdraws from the inside.

  At this time, as the first cylinder 11 moves up in the second cylinder 21, the oil in the fluid chamber B2 passes through the extension side passage 22b, deforms and opens a disk valve (not shown), and is guided to the fluid chamber B1. . Thereby, an extension side damping force is generated in the second cylinder 21. Further, in the fluid chamber B1, the oil corresponding to the retraction volume of the piston rod 3 retreating from the inner cylinder 21b is insufficient, so that the second through the check valve 23c (see FIG. 3) of the second bottom valve 23. Oil is supplied from the reservoir chamber B3 to the fluid chamber B1. As a result, a damping force is generated by the flow resistance when passing through the passage 23d (see FIG. 3) of the second bottom valve 23.

  Here, when the piston rod 3 is moved to the compression side after the movement to the extension side, the operation opposite to the above-described operation, that is, from the state shown in FIG. The first cylinder 11 is returned by the elasticity of the bottom spring 24 in the second cylinder 21 so that the state shown in FIG. 6B is obtained, and then the state shown in FIG. 6B from the state shown in FIG. The piston rod 3 is returned so that

  According to the damping device 1 of the present embodiment described above, a double-structure damping device 1 in which the first damping member 10 is included in the second damping member 20 is obtained, and the external force input to the piston rod 3 is applied to these. It can be attenuated by the two attenuation members 10 and 20.

  In addition, since the external force input to the piston rod 3 is attenuated by the first damping member 10 and then attenuated by the second damping member 20, the external force that has not been attenuated by the first damping member 10 is It is possible to realize stepwise attenuation in which the second attenuation member 20 attenuates. That is, during normal driving of the vehicle, the first damping member 10 can be set so that the damping force is softened to obtain a soft shock absorption characteristic, and when the vehicle rolls, the second damping member 20 can reduce the damping force. It can be set so that a hard shock absorbing characteristic can be obtained by making the hard. Therefore, the damping device 1 having a high degree of freedom of variable damping force is obtained.

  Further, since the first cylinder 11 as the first damping member 10 is included in the second cylinder 21 as the second damping member 20, and the first cylinder 11 functions as a piston of the second cylinder 21, it is simple. The damping device 1 having a double structure is obtained in the configuration, and the external force input to the piston rod 3 can be damped by the action in the two first cylinders 11 and second cylinders 21. As a result, a stepwise attenuation characteristic of attenuating the external force that has not been attenuated in the first cylinder 11 in the second cylinder 21 can be realized with a simple structure.

  Further, the stroke for reducing the damping force in the damping device 1 is caused by the sliding of the first cylinder piston 12 in the first cylinder 11 and the sliding of the first cylinder 11 itself in the second cylinder 21. As a result, the stroke for reducing the damping force can be secured without increasing the overall length of the damping device 1, and the damping device 1 is compact and excellent in damping capability. Is obtained. Further, a large damping force can be obtained with a small stroke, space saving can be achieved, and it can be suitably provided in a narrow space around the tire house.

  Further, since the viscosity of the oil in the second cylinder 21 is greater than the viscosity of the oil in the first cylinder 11, the input from the piston rod 3 is attenuated by the first cylinder 11 and then attenuated by the second cylinder 21. The damping device 1 can be configured easily. Further, it is possible to freely set a region where the damping force is varied by adjusting the viscosity of the oil. In addition, it is possible to freely change the setting according to the characteristics of the suspension for each vehicle type.

  Further, the first cylinder 11 is held at a predetermined position in the second cylinder 21 by the bottom spring 24 that expands and contracts in the sliding direction of the first cylinder 11, so that the first cylinder 11 is moved to the predetermined position after receiving an external force. Excellent returnability and stable damping force characteristics can be obtained. Further, the first cylinder 11 can be smoothly slid by the expansion and contraction of the bottom spring 24. Further, the vibration absorption when the first cylinder 11 makes a small stroke is improved, and the riding feeling is improved.

As mentioned above, although embodiment which concerns on this invention was described, it cannot be overemphasized that this invention is not limited to these, The appropriate change implementation according to the main point of invention is possible. For example, in the above embodiment, the viscosity of the oil in the second cylinder 21 is set to be larger than the viscosity of the oil in the first cylinder 11, but the present invention is not limited to this. The oil viscosity may be set larger than the oil viscosity of the second cylinder 21.
Further, as a method of making the damping characteristics of the first damping member 10 and the second damping member 20 different, changing the specifications of the passages and valves of the first cylinder piston 12 and the second cylinder piston 22 is mentioned. It is done. In this case, even if the oil viscosity of the 1st cylinder 11 and the 2nd cylinder 21 is the same, a damping characteristic can be varied by changing the flow rate of the station which passes a valve etc.
Further, the inside of the first cylinder 11 and the inside of the second cylinder 21 may be divided into three or more fluid chambers.

It is the figure which looked at the structure around the right front wheel for demonstrating the damping device which concerns on one embodiment of this invention from the back side. It is a disassembled perspective view for demonstrating an installation state similarly. It is an expanded sectional view of the damping device concerning one embodiment of the present invention. It is a schematic cross section similarly. (A)-(c) is an operation explanatory view at the time of bump stroke (at the time of compression). (A)-(c) is an effect explanatory view at the time of a rebound stroke (at the time of extension).

Explanation of symbols

1 damping device 2 cylinder tube 3 piston rod 3b first cylinder rebound rubber 3c sub bump stop rubber 4 bump stop rubber A1, A2 fluid chamber A3 first reservoir chamber B1, B2 fluid chamber B3 second reservoir chamber 10 first damping member DESCRIPTION OF SYMBOLS 11 1st cylinder 12 1st cylinder piston 13 1st bottom valve 20 2nd damping member 21 2nd cylinder 22 2nd cylinder piston 23 2nd bottom valve 24 Bottom spring 26 2nd cylinder rebound rubber

Claims (4)

  An input unit to which an external force is input, a first damping member that attenuates the external force input to the input unit, and a first damping member that is movably included, and attenuates the external force that is input to the first damping member And a second damping member. The first damping member includes a first cylinder filled with a viscous fluid, and a first cylinder piston that is slidably provided in the first cylinder and divides the first cylinder into at least two fluid chambers. Comprising
The second damping member is configured to include a second cylinder filled with a viscous fluid and slidably including the first cylinder;
The input unit is connected to the first cylinder piston of the first damping member;
2. The damping device according to claim 1, wherein the first cylinder of the first damping member functions as a piston of a second cylinder of the second damping member.   The damping device according to claim 2, wherein the first cylinder and the second cylinder are configured to have different damping characteristics.   4. The damping device according to claim 2, wherein the first cylinder is held at a predetermined position in the second cylinder by an elastic member that expands and contracts in a sliding direction of the first cylinder. 5.

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