JPH11280827A - Hydraulic damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a drive comfortability and a running stability consistent with each other by adjusting a degree of stroke of a piston rod in accordance with a running condition. SOLUTION: A hydraulic damper is provided therein with a rebound stopper displacing mechanism 11 for axially replacing a rebound stopper 25, and a bump stopper displacing mechanism 30 for axially displacing a bump stopper 35. With this arrangement, when a vehicle runs on an ordinary road in a city, the rebound stopper 25 is displaced downward while the bump stopper 35 is displaced upward so as to increase the degree of stroke of a piston rod 10 in order to enhance the drive comfortability. Meanwhile, when the vehicle runs on a mountain road or the like, the rebound stopper 25 is displaced upward while the bump stopper 35 is displaced downward so as to decrease the degree of stroke of the piston rod 10 in order to restrain a tilt of the vehicle upon cornering.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic shock absorber suitably used for damping, for example, vibration of a vehicle.

[0002]

2. Description of the Related Art Generally, a hydraulic shock absorber according to the prior art is
A cylinder, a piston slidably inserted into the cylinder, and a piston defined inside the cylinder as a rod-side oil chamber and a bottom-side oil chamber; a base end fixed to the piston; and a distal end outside the cylinder. A protruding piston rod, an extension-side stopper provided on a base end side of the piston rod, and elastically abutting on the cylinder when the piston rod extends out of the cylinder, and an extension-side stopper provided on a distal end side of the piston rod. The piston rod is roughly constituted by a reduction-side stopper that elastically contacts the cylinder when the piston rod is reduced into the cylinder. For example, the piston applies resistance to the oil liquid flowing between the oil chambers. A damping force generating means is provided.

[0003] In the hydraulic shock absorber configured as described above, for example, the bottom side of the cylinder is mounted on the axle side of the vehicle, and the distal end side of the piston rod is mounted on the vehicle body side of the vehicle.

Thus, when the vehicle runs and the vehicle body vibrates due to irregularities on the road surface or the like, the piston rod extends and contracts from the cylinder, and the damping force generating means provided on the piston generates a damping force. The vibration at this time is attenuated.

Further, when the piston rod extends greatly from the cylinder, such as when climbing over a step,
The extension-side stopper elastically abuts the cylinder to reduce the impact near the maximum extension of the piston rod. On the other hand, when the piston rod is significantly reduced, the reduction-side stopper elastically contacts the cylinder to reduce the impact near the minimum reduction of the piston rod.

[0006]

By the way, in the above-described conventional hydraulic shock absorber, the extension of the piston rod,
The ride comfort of the vehicle can be improved by increasing the stroke at the time of reduction. However, in this case, since the inclination of the vehicle body at the time of cornering becomes large, there is a problem that running stability is deteriorated on a mountain road where a curve is continuous.

In order to improve running stability, it is conceivable to install the extension-side stopper and the reduction-side stopper close to the cylinder to suppress the inclination of the vehicle body during cornering. Side stopper and reduction side stopper come into easy contact with the cylinder,
There is a problem that the ride comfort of vehicles on general roads and the like in town is deteriorated.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to utilize a pumping action when a piston reciprocates in a cylinder, and to adjust a stroke amount of a piston rod according to running conditions. It is an object of the present invention to provide a hydraulic shock absorber capable of adjusting the vehicle comfort and achieving both riding comfort and running stability.

[0009]

A hydraulic shock absorber according to the present invention is provided with a cylinder filled with an oil solution, slidably inserted into the cylinder, and a rod-side oil chamber and a bottom-side oil inside the cylinder. A piston defined in the chamber, a piston rod having a proximal end fixed to the piston and a distal end protruding out of the cylinder, and a piston rod provided on the proximal end of the piston rod, the piston rod extending out of the cylinder An extension-side stopper that elastically abuts the cylinder, and a reduction-side stopper that is provided at the distal end of the piston rod and elastically abuts the cylinder when the piston rod is reduced into the cylinder. Have.

[0010] In order to solve the above-mentioned problems,
A feature of the configuration adopted by the invention of claim 1 is that extension side stopper displacement means provided between the piston rod and the extension side stopper, and displaces the extension side stopper in the axial direction with respect to the piston rod, A reducing-side stopper displacing means provided between the piston rod and the reducing-side stopper and displacing the reducing-side stopper in the axial direction with respect to the piston rod; It is configured by a hydraulic actuator provided so as to be displaceable in the axial direction of the piston rod, and the hydraulic actuator is configured to be operated by an oil liquid in the cylinder guided when the piston is displaced in the cylinder. is there.

With this configuration, the hydraulic actuator can be operated by the oil liquid guided from the oil chamber in the cylinder by utilizing the pumping action when the piston is displaced in the cylinder. When traveling on a general road or the like, the extension-side stopper is disposed away from the cylinder by the extension-side stopper displacement means, and the reduction-side stopper is disposed away from the cylinder by the reduction-side stopper displacement means. Thereby, the stroke amount of the piston rod can be increased, and the riding comfort of the vehicle can be improved. On the other hand, when the vehicle travels on a mountain road where a curve is continuous, the extension-side stopper is disposed closer to the cylinder by the extension-side stopper displacement means, and the reduction-side stopper is disposed closer to the cylinder by the reduction-side stopper displacement means. Thus, the stroke amount of the piston rod can be reduced, and the inclination of the vehicle body during cornering can be suppressed to improve running stability.

According to a second aspect of the present invention, the extension-side stopper displacement means comprises a hydraulic actuator having an extension-side stopper movably supported in the axial direction of the piston rod, and a bottom-side oil chamber or rod-side oil in the cylinder and the hydraulic actuator. An oil passage communicating with any one of the oil chambers of the chamber, and a control valve mechanism provided in the middle of the oil passage. The reduction-side stopper displacement means moves the reduction-side stopper in the axial direction of the piston rod. A hydraulic actuator movably supported by the hydraulic actuator, an oil through-hole communicating the hydraulic actuator with one of the rod-side oil chamber and the bottom-side oil chamber in the cylinder, and provided in the middle of the oil through-hole. And a control valve mechanism.

[0013] With this configuration, when the oil communication hole is communicated and closed by the control valve mechanism, the oil liquid is supplied from the oil chamber in the cylinder to the hydraulic actuator by the pumping action when the piston is displaced in the cylinder. Therefore, the hydraulic actuator is operated using the oil liquid in the oil chamber, and the extension-side stopper and the reduction-side stopper can be displaced.

According to a third aspect of the present invention, the control valve mechanism is provided in parallel with the on-off valve that communicates and shuts off the oil through-hole, and allows the flow of the oil liquid only from the oil chamber in the cylinder to the hydraulic actuator. And a check valve that allows the above.

With this configuration, when the oil passage is communicated with the on-off valve, the oil liquid freely flows between the oil chamber in the cylinder and the hydraulic actuator. The stopper is movable in the axial direction of the piston rod, and the stroke amount at this time is large. On the other hand, when the oil through hole is closed by the open / close valve, the oil liquid in the oil chamber is unilaterally supplied to the hydraulic actuator via the check valve, so that the extension side stopper and the reduction side stopper are brought closer to the cylinder by the hydraulic actuator. Is fixed at the set position, and the stroke amount at this time becomes small.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A hydraulic shock absorber according to an embodiment of the present invention will be described below in detail with reference to FIGS.

Reference numeral 1 denotes an outer cylinder forming an outer shell of the hydraulic shock absorber, and 2 denotes an inner cylinder as a cylinder coaxially disposed in the outer cylinder 1.
The lower end of the outer cylinder 1 is gas-liquid-tightly closed by a bottom cap 3, and an annular oil chamber A provided between the outer cylinder 1 and the inner cylinder 2 is provided at the bottom 2 </ b> A of the inner cylinder 2. Damping force generating mechanisms 4 and 5 for providing resistance to the oil flowing through the bottom oil chamber C are provided. A rod guide 6 is provided at the upper end side of the outer cylinder 1 and the inner cylinder 2.
Is formed as a guide hole 6A for supporting a piston rod 10 described later. Further, the bottom cap 3 is provided with a mounting eye (not shown) for mounting on the axle side of the vehicle.

Reference numeral 7 denotes a piston slidably inserted into the inner cylinder 2. The piston 7 defines the inside of the inner cylinder 2 as a rod-side oil chamber B and a bottom-side oil chamber C. Further, the piston 7 is provided with damping force generating mechanisms 8 and 9 for applying resistance to the oil liquid flowing between the rod-side oil chamber B and the bottom-side oil chamber C.

Reference numeral 10 denotes a piston rod whose lower end is fixed to the piston 7 and whose upper end protrudes out of the inner cylinder 2 through the guide hole 6A of the rod guide 6. The upper end of the piston rod 10 is on the vehicle body side of the vehicle. Screw part 10A for mounting
Is provided. Further, the lower end side of the piston rod 10 is a cylindrical portion 10B, and the cylindrical portion 10B has oil through holes 10C,
10D is formed in the radial direction.

Reference numeral 11 denotes a rebound stopper displacement mechanism as extension side stopper displacement means provided on the lower end side of the piston rod 10. The rebound stopper displacement mechanism 11
Is generally constituted by a hydraulic actuator 12, an oil passage hole 15, a control valve mechanism 16, and the like, which will be described later.

Reference numeral 12 denotes a hydraulic actuator provided on the outer peripheral side of the cylindrical portion 10B of the piston rod 10. The hydraulic actuator 12 includes a fixed cylindrical body 13 fitted to the outer peripheral side of the cylindrical portion 10B in an axially positioned state. The movable cylinder 14 is fitted on the outer peripheral side of the fixed cylinder 13 and is movable in the axial direction of the piston rod 10.
On the outer peripheral side of the fixed cylindrical body 13, an annular convex portion 13 </ b> A is provided so as to protrude radially over the entire circumference, and at an upper end and a lower end of the movable cylindrical body 14, protrudes radially inward. An upper flange portion 14A and a lower flange portion 14B which are in sliding contact with the outer peripheral surface of the fixed cylindrical body 13 are provided, and the annular convex portion 13A and the upper flange portion 14 are provided.
An oil chamber D is provided between A and A. Further, the fixed cylinder 13
The oil chamber 10D of the piston rod 10 and the oil chamber D
And an oil passage hole 13B that communicates with the oil passage.

The hydraulic actuator 12 has a rebound stopper 25 (described later) above the movable cylinder 14.
And when the oil liquid is supplied to the oil chamber D, the rebound stopper 25 is displaced upward in the axial direction of the piston rod 10.

Reference numeral 15 denotes an oil through hole provided along the axis of the piston 7. The oil through hole 15 is an oil through hole 10D of the piston rod 10, an oil through hole 13B of the fixed cylindrical body 13 and the like. Oil chamber D and the bottom side oil chamber C are communicated.

Reference numeral 16 denotes a control valve mechanism serving as control valve means provided in the cylindrical portion 10B of the piston rod 10. The control valve mechanism 16 includes a valve case 17, a valve seat cylinder 20, a valve cylinder 21, a check valve It is roughly constituted by valves 23, 24 and the like.

Reference numeral 17 denotes a valve case which is inserted into the cylindrical portion 10 B of the piston rod 10.
A and a bottom portion 18B, a tubular body 18 formed into a bottomed tubular shape, and a lid body 19 closing the upper side of the tubular body 18 are formed. And the oil chamber F on the side. The cylindrical portion 1 of the cylindrical body 18
8A, an oil through hole 18C communicating with the rod side oil chamber B via an oil through hole 10C of the piston rod 10, an oil through hole 18D communicating with the oil chamber E, and an oil through hole communicating with the oil chamber F. 18E
The bottom portion 18B has an oil passage hole 18F for communicating the oil chamber H with the oil chamber F via the check valve 23, and an oil chamber H
And an oil through hole 18 </ b> G communicating the oil through hole 15 with the oil through hole 15. Further, the lid 19 is provided with an oil passage hole 19 </ b> A that communicates the oil chamber G with the oil chamber E via the check valve 24.

Reference numeral 20 denotes a valve seat cylinder inserted into the valve case 17, and the valve seat cylinder 20 has oil through holes 18C, 1C of the cylindrical body 18.
Oil through holes 20A, 20B, 20C communicating with 8D, 18E
Is provided.

Reference numeral 21 denotes a valve cylinder which is rotatably inserted into the valve seat cylinder 20 and forms an open / close valve together with the valve seat cylinder 20.
Numeral 1 is formed in a closed cylindrical shape by a cylindrical portion 21A and a lid portion 21B, and the inside thereof is defined by a partition 21C into an upper oil chamber G and a lower oil chamber H. Further, the cylinder portion 21A has an oil through hole 2 that is always in communication with the oil through hole 20A of the valve seat cylinder 20.
1D, an oil through hole 21E corresponding to the oil through hole 20B, and an oil through hole 21F corresponding to the oil through hole 20C are provided.
In addition, an oil through hole 21 </ b> G communicating with the oil through hole 19 </ b> A of the lid 19 is provided in the lid 21 </ b> B.

Reference numeral 22 denotes a control rod whose lower end is fixed to the center of the lid 21B of the valve cylinder 21 and whose upper end extends in an oil through hole 34 described later and protrudes from the piston rod 10.
The control rod 22 is rotated by an electric motor 36, which will be described later, to rotate the valve cylinder 21 and to connect the oil through holes 21E and 21F to the oil through holes 20 of the valve seat cylinder 20.
B and 20C are communicated and blocked.

Reference numeral 23 denotes a check valve provided on the bottom portion 18B of the cylindrical body 18. The check valve 23 is formed by a plurality of disc valves, and is arranged in parallel with the valve seat cylinder 20 and the valve cylinder 21 which form an on-off valve. Have been. And check valve 2
Numeral 3 allows the oil liquid supplied from the bottom side oil chamber C via the oil through hole 15 to flow out to the oil chamber F toward the hydraulic actuator 12, and prevents the reverse flow.

A check valve 24 is provided on the lid 19, and the check valve 24 is formed by a plurality of disk valves, and is arranged in parallel with the valve seat cylinder 20 and the valve cylinder 21 which form an on-off valve. I have. The check valve 24 allows the oil liquid to flow from the rod-side oil chamber B toward the hydraulic actuator 31 toward the oil chamber E, and prevents the reverse flow.

Reference numeral 25 denotes a rebound stopper, which is located at the lower end side of the piston rod 10 and is supported by the hydraulic actuator 12 as an extension-side stopper. The rebound stopper 25 is formed above the upper flange 14A of the movable cylinder 14. A coil spring 27 provided through the cutout 26 provided,
A spring receiver 28 is provided on the upper end side of the coil spring 27 and slidably fitted on the outer peripheral side of the piston rod 10, and an elastic ring 29 fixed on the spring receiver 28. When the piston rod 10 is greatly extended, the rebound stopper 25 causes the elastic ring 29 to abut on the rod guide 6 so that the elastic force of the elastic ring 29 and the spring force of the coil spring 27 cause the rebound stopper 25 in the vicinity of the maximum extension. This is to reduce the impact. Notch 2
Numeral 6 permits the flow of the oil liquid between the rod-side oil chamber B and the oil passage hole 10C when the movable cylinder 14 moves upward.

Numeral 30 is a bump stopper displacement mechanism as reduction means stopper displacement means provided on the upper end side of the piston rod 10. The bump stopper displacement mechanism 30 includes the above-described control valve mechanism 16 and a hydraulic actuator 31 described later. , An oil passage hole 34 and the like.

Reference numeral 31 denotes a hydraulic actuator provided on the outer peripheral side of the upper end of the piston rod 10. The hydraulic actuator 31 is fitted to the upper end of the piston rod 10 in an axially positioned state as shown in FIG. A cylindrical fixed cylinder 32, and a movable cylinder 3 fitted on the outer peripheral side of the fixed cylinder 32 and movable in the axial direction of the piston rod 10.
3. In addition, the fixed cylinder 32
An annular convex portion 32A is provided to protrude in the radial direction over the entire circumference on the outer peripheral side of the movable cylindrical body 33. The outer peripheral surface of the fixed cylindrical body 32 protrudes radially inward at the upper and lower ends of the movable cylindrical body 33. An upper flange portion 33A and a lower flange portion 33B are provided so as to be in sliding contact with each other, and an oil chamber J is provided between the annular convex portion 32A and the lower flange portion 33B. Further, the fixed cylindrical body 32 is provided with an oil through hole 32B that communicates the oil through hole 34 with the oil chamber J.

The hydraulic actuator 31 supports a bump stopper 35 described below below the movable cylinder 33, and when the oil liquid is supplied to the oil chamber J, moves the bump stopper 35 to the shaft of the piston rod 10. It is displaced downward in the direction.

Numeral 34 denotes an oil through hole extending in the axial direction from the center of the piston rod 10. Above the oil through hole 34, the oil through hole extends in the radial direction and extends through the oil through hole 32 B of the hydraulic actuator 31. A communicating radial oil hole 34A is provided.
The oil through hole 34 is connected to the oil through hole 1 of the piston rod 10.
The oil chamber J of the hydraulic actuator 31 communicates with the rod-side oil chamber B together with 0C or the like.

Reference numeral 35 denotes a bump stopper which is located on the outer peripheral side of the piston rod 10 and is fixed to the movable cylinder 33 of the hydraulic actuator 31. The bump stopper 35 is formed in a stepped cylindrical shape by using, for example, an elastic rubber material. Have been. Then, the bump stopper 35 is attached to the piston rod 1.
When 0 is greatly reduced, it comes into contact with the rod guide 6 to relieve the impact near the minimum reduction by the elastic force.

An electric motor 36 is provided on the upper end of the piston rod 10. The upper end of the control rod 22 is attached to the electric motor 36. The electric motor 36 is operated by the controller 37 based on detection signals output from various sensors (not shown) that detect the running state of the vehicle, and the signal output from the controller 37 is used to control the electric motor 36 via the control rod 22. Valve 2
1 is rotated.

The hydraulic shock absorber according to the present embodiment has the above-described configuration, and its operation will be described next.

First, when the posture change during running is small, such as on a general road in town, as shown in FIGS. 1 to 3, the electric motor 3 is controlled by a signal from the controller 37.
6 pivots the control rod 22, and connects the oil through holes 21E and 21F of the valve cylinder 21 to the oil through holes 20B and 20C of the valve seat cylinder 20.
To communicate with

In this state, the bottom oil chamber C in the inner cylinder 2
Are oil through holes 15, 18G, oil chamber H, oil through holes 21F, 20
C, 18E, the oil chamber F, and the oil chamber D of the hydraulic actuator 12 via the oil through holes 10D, 13B, and the oil liquid freely flows between the bottom oil chamber C and the oil chamber D. . As a result, the rebound stopper 25 is
Is displaced downward by contact with the rod guide 6, and moves away from the rod guide 6 at a position where the upper flange portion 14 </ b> A of the movable cylinder 14 abuts on the annular projection 13 </ b> A of the fixed cylinder 13 of the hydraulic actuator 12. Functions as a stopper at the position.

The rod-side oil chamber B in the inner cylinder 2 has oil through holes 10C, 18C, 20A, 21D, an oil chamber G, and an oil through hole 21.
E, 20B, 18D, oil chamber E, oil through holes 34, 34A, 3
2B, the hydraulic fluid is communicated with the oil chamber J of the hydraulic actuator 31, and the oil liquid freely flows between the rod-side oil chamber B and the oil chamber J. As a result, the bump stopper 35 is displaced upward by contacting the rod guide 6, and the position where the lower flange 33 </ b> B of the movable cylinder 33 abuts on the annular projection 32 </ b> A of the fixed cylinder 32 of the hydraulic actuator 31. That is, it functions as a stopper at a position away from the rod guide 6.

As described above, by making the rebound stopper 25 and the bump stopper 35 function as stoppers at positions away from the rod guide 6, the stroke at the time of extension and contraction of the piston rod 10 can be increased. The ride comfort at the time can be improved.

On the other hand, as in a mountain pass where curves are continuous,
When the posture change during running is large, the control rod 22 is rotated by the electric motor 36 as shown in FIG.
The oil through holes 21E, 21F of the valve cylinder 21 are circumferentially shifted with respect to the oil through holes 20B, 20C of the valve seat cylinder 20, and the oil through holes 21E, 21C are shifted.
It shuts off between 21F and oil passage holes 20B and 20C.

In this state, the bottom oil chamber C in the inner cylinder 2
Are communicated with the oil chamber D of the hydraulic actuator 12 via the oil through holes 15, 18G, the oil chamber H, the oil through hole 18F, the check valve 23, the oil chamber F, and the oil through holes 10D, 13B. The valve 23 allows only the flow of the oil liquid from the bottom side oil chamber C to the oil chamber D, and prevents the reverse flow. This allows
When the piston 7 is displaced downward, the oil liquid in the bottom oil chamber C flows unilaterally into the oil chamber D of the hydraulic actuator 12, so that the rebound stopper 25 is moved upward in the axial direction by the hydraulic actuator 12. , And is fixed at a position where the lower flange portion 14B of the movable cylinder 14 abuts on the annular projection 13A of the fixed cylinder 13 of the hydraulic actuator 12, that is, a position near the rod guide 6.

The rod-side oil chamber B in the inner cylinder 2 has oil through holes 10C, 18C, 20A, 21D, an oil chamber G, and an oil through hole 21.
G, 19A, check valve 24, oil chamber E, oil through holes 34, 3
4A and 32B communicate with the oil chamber J of the hydraulic actuator 31, but the check valve 24 allows only the flow of the oil liquid from the rod-side oil chamber B to the oil chamber J and prevents the reverse flow. I do. As a result, when the piston 7 is displaced upward, the oil liquid in the rod-side oil chamber B will flow unilaterally into the oil chamber J of the hydraulic actuator 31. Is displaced downward, and is fixed at a position where the upper flange portion 33A of the movable cylinder 33 abuts on the annular projection 32A of the fixed cylinder 32 of the hydraulic actuator 31, that is, at a position closer to the rod guide 6.

As described above, by fixing the rebound stopper 25 and the bump stopper 35 at positions close to the rod guide 6, the stroke amount when the piston rod 10 is extended and contracted can be reduced. The running stability can be improved by suppressing the lean of the vehicle body.

As described above, according to the present embodiment, between the piston rod 10 and the rebound stopper 25,
A rebound stopper displacement mechanism 11 for displacing the rebound stopper 25 in the axial direction with respect to the piston rod 10 is provided, and between the piston rod 10 and the bump stopper 35, the bump stopper 35 is displaced in the axial direction with respect to the piston rod 10. The configuration is such that a bump stopper displacement mechanism 30 is provided.

Thus, when the vehicle travels, for example, on a general road in a town, the rebound stopper 25 is displaced downward by the rebound stopper displacement mechanism 11 and the bump stopper 35 is displaced by the bump stopper displacement mechanism 30. By displacing the piston upward, the stroke of the piston rod 10 can be increased to improve the riding comfort. Moreover, when traveling on a mountain pass or the like, the stroke of the piston rod 10 is reduced by displacing the rebound stopper 25 upward by the rebound stopper displacement mechanism 11 and displacing the bump stopper 35 downward by the bump stopper displacement mechanism 30. By making it smaller, the inclination of the vehicle body during cornering can be suppressed and running stability can be increased.

As a result, the stroke amount of the piston rod 10 can be adjusted according to the running conditions of the vehicle, so that the riding comfort and running stability of the vehicle can be compatible, and the performance of the hydraulic shock absorber is improved. be able to.

The rebound stopper displacement mechanism 11
Are connected to the hydraulic actuator 12 supporting the rebound stopper 25, and the oil passage holes 15, 18 for communicating the oil chamber D of the hydraulic actuator 12 with the bottom oil chamber C in the inner cylinder 2.
, And a control valve mechanism 16 provided in the middle of the oil through holes 15, 18G,.
Check valve 23 permits only the flow of the oil liquid from the bottom oil chamber C to the oil chamber D.

The control valve mechanism 16 shuts off the oil holes 15, 18G,.
The oil liquid can be supplied from the bottom side oil chamber C to the oil chamber D of the hydraulic actuator 12 using the pumping action by the reciprocating motion of the hydraulic actuator 12, so that it is not necessary to use a separate hydraulic pump or the like, and the rebound is simple. The stopper 25 and the bump stopper 35 can be displaced.

Further, by rotating the control rod 22 by the electric motor 36, the valve cylinder 21 constituting the on-off valve is rotated to communicate and shut off the oil through holes 15, 34 and the like. Oil through holes 15, 34 based on a signal output from a controller 37 provided in
Can be communicated and cut off, and the stroke amount of the piston rod 10 can be automatically controlled.

In the embodiment, the control rod 22 is rotated by the electric motor 36. However, the present invention is not limited to this, and the control rod 22 is rotated manually. Is also good.

In the embodiment, the on-off valve is connected to the valve seat cylinder 2.
0 and the valve cylinder 21, and the case where the valve cylinder 21 is rotated by the control rod 22 has been described as an example. However, the present invention is not limited to this.
May be configured as in the modification shown in FIG.

That is, as in the modification shown in FIG. 5, a two-port, two-position electromagnetic opening / closing valve 42 is provided in the middle of an oil through hole 41 that connects the bottom side oil chamber C and the oil chamber D of the hydraulic actuator 12.
And a check valve 43 is provided in parallel with the electromagnetic on-off valve 42 so that the rod-side oil chamber B and the hydraulic actuator 31
A two-port, two-position electromagnetic on-off valve 45 is provided in the middle of an oil through hole 44 that communicates with the oil chamber J.
A check valve 46 is provided in parallel with the electromagnetic on-off valve 42,
45 may be configured to be controlled based on an electric signal from the controller 47. In this case, the rebound stopper 25 and the bump stopper 35 can be displaced separately, and complicated control of the hydraulic shock absorber becomes possible. Also, the check valves 43 and 46 are connected to the electromagnetic on-off valves 42 and 45.
It is good also as a structure built in.

In the embodiment, the oil liquid in the bottom oil chamber C is guided to the hydraulic actuator 12 of the rebound stopper displacement mechanism 11, and the oil liquid in the rod oil chamber B is guided to the hydraulic actuator 31 of the bump stopper displacement mechanism 30. Although the case where the liquid is guided is exemplified, the present invention is not limited to this.
For example, as shown by a two-dot chain line in FIG. 1, by connecting an oil through hole 51 provided in place of the oil through hole 15 to the rod side oil chamber B, the hydraulic actuator 12 of the rebound stopper displacement mechanism 11 It may be configured to guide the oil liquid in the side oil chamber B. Further, the oil liquid in the bottom oil chamber C may be guided to the hydraulic actuator 31 of the bump stopper displacement mechanism 30.

In the embodiment, the oil passage holes 20B and 20C of the valve seat cylinder 20 are arranged at the same circumferential position, and
By arranging the first oil passage holes 21E and 21F at the same position in the circumferential direction, the rebound stopper displacement mechanism 11 and the bump stopper displacement mechanism 30 are simultaneously controlled, but instead, for example, a valve seat may be used. Oil through hole 20 of cylinder 20
B, 20C at different positions in the circumferential direction, or
By arranging one oil passage hole 21E, 21F at a different position in the circumferential direction, the rebound stopper displacement mechanism 11 and the bump stopper displacement mechanism 30 may be controlled separately.

The controller 37 controls the valve cylinder 2
The rotation angle of 1 may be controlled to adjust the flow rate of the oil liquid flowing through the oil through holes 15 and 34. In this case, the moving speed of the rebound stopper 25 and the bump stopper 35 can be adjusted. , More complicated control becomes possible.

Further, in the embodiment, the outer cylinder 1 and the inner cylinder 2
Although described as an example of a multi-cylinder type hydraulic shock absorber having, the present invention is not limited thereto, for example, a free piston,
The present invention may be applied to a single cylinder type hydraulic shock absorber having an accumulator or the like.

[0060]

As described above in detail, according to the first aspect of the present invention, the extension-side stopper displacement means is provided between the piston rod and the extension-side stopper, and the reduction-side stopper is provided between the piston rod and the reduction-side stopper. Displacement means is provided, and the extension-side stopper displacement means and the reduction-side stopper displacement means are constituted by a hydraulic actuator that displaces in the axial direction of the piston rod,
Since the hydraulic actuator is operated by the oil liquid in the cylinder which is guided when the piston is displaced in the cylinder, the pumping action when the piston is displaced (reciprocating) in the cylinder is utilized to make use of the pumping action in the cylinder. The hydraulic actuator can be operated by the oil liquid guided from the oil chamber, and the extension-side stopper and the reduction-side stopper can be displaced by the hydraulic actuator.

Thus, for example, when traveling on a general road or the like in a town, the extension-side stopper is located away from the cylinder by the extension-side stopper displacement means, and the reduction-side stopper is moved away from the cylinder by the reduction-side stopper displacement means. To place. Therefore, the stroke amount of the piston rod increases, so that the riding comfort of the vehicle can be improved.

On the other hand, when the vehicle travels on a mountain road where curves are continuous, the extension side stopper is disposed closer to the cylinder by the extension side stopper displacement means, and the reduction side stopper is brought closer to the cylinder by the reduction side stopper displacement means. Deploy. Therefore, since the stroke amount of the piston rod is reduced, the inclination of the vehicle body at the time of cornering can be suppressed and the running stability can be improved. Therefore, the stroke amount of the piston rod can be adjusted according to the running conditions of the vehicle, and both the riding comfort and the running stability of the vehicle can be achieved. Further, it is not necessary to use a separate hydraulic pump, and the extension-side stopper and the reduction-side stopper can be displaced with a simple configuration.

According to the second aspect of the present invention, a hydraulic actuator in which the extension-side stopper displacement means and the reduction-side stopper displacement means are supported so that the stopper is movable in the axial direction of the piston rod, and the hydraulic actuator and the oil chamber in the cylinder And a control valve mechanism provided in the middle of the oil through hole. This allows the control valve mechanism to communicate and shut off the oil through hole, so that the pumping action when the piston is displaced allows the oil chamber to supply oil from the oil chamber in the cylinder to the hydraulic actuator, and uses the oil in the oil chamber. As a result, the hydraulic actuator can be operated, so that there is no need to use a separate hydraulic pump, and the extension-side stopper and the reduction-side stopper can be displaced with a simple configuration.

According to the third aspect of the present invention, the control valve mechanism is
An open / close valve that communicates and shuts off the oil through hole, and a check valve that is provided in parallel with the open / close valve and that allows the flow of the oil liquid only from the oil chamber in the cylinder to the hydraulic actuator. In the state where the oil through hole is communicated, the oil liquid can freely flow between the oil chamber in the cylinder and the hydraulic actuator, and the extension-side stopper and the reduction-side stopper can be freely moved in the axial direction of the piston rod, At this time, the stroke amount of the piston rod can be increased.

On the other hand, when the oil passage hole is closed by the on-off valve, the oil liquid in the oil chamber can be unilaterally supplied to the hydraulic actuator via the check valve. The actuator can be fixed at a position close to the cylinder, and the stroke amount of the piston rod at this time can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a hydraulic shock absorber according to an embodiment of the present invention.

FIG. 2 is an enlarged vertical cross-sectional view of a main part showing the rebound stopper displacement mechanism and the rebound stopper in FIG. 1 in an enlarged manner.

FIG. 3 is an enlarged longitudinal sectional view of a main part showing a flow of an oil liquid when a stroke amount of a piston rod is increased.

FIG. 4 is an enlarged vertical sectional view of a main part as viewed from the same position as in FIG. 3, showing a flow of an oil liquid when a stroke amount of a piston rod is reduced.

FIG. 5 is an enlarged longitudinal sectional view of a main part showing a hydraulic shock absorber according to a modification of the present invention.

[Explanation of symbols]

2 inner cylinder (cylinder) 7 piston 10 piston rod 11 rebound stopper displacement mechanism (extension side stopper displacement means) 12, 31 hydraulic actuator 15, 34, 41, 44, 51 oil through hole 16 control valve mechanism 20 valve seat cylinder (open / close) Valve) 21 Valve cylinder (open / close valve) 23, 24, 43, 46 Check valve 25 Rebound stopper (extension side stopper) 30 Bump stopper displacement mechanism (reduction side stopper displacement means) 35 Bump stopper (reduction side stopper) B Rod side oil Chamber C Bottom side oil chamber

Claims (3)

[Claims] 1. A cylinder filled with an oil liquid, a piston slidably inserted into the cylinder and defining a cylinder in a rod-side oil chamber and a bottom-side oil chamber in the cylinder, and A piston rod fixed to a piston and having a distal end protruding outside the cylinder; and an extension side provided on a base end side of the piston rod and elastically abutting on the cylinder when the piston rod extends out of the cylinder. A stopper,
A hydraulic shock absorber provided on a tip end side of the piston rod and having a reduction side stopper elastically abutting on the cylinder when the piston rod is reduced into the cylinder, wherein the piston rod and the extension side stopper; And an extension-side stopper displacement means for displacing the extension-side stopper in the axial direction with respect to the piston rod; and an extension-side stopper provided between the piston rod and the reduction-side stopper; And a reduction-side stopper displacement means for displacing the piston rod in the axial direction. The actuator is guided in the cylinder when the piston is displaced in the cylinder. A hydraulic shock absorber characterized by being operated by an oil liquid. 2. The extension-side stopper displacement means includes: a hydraulic actuator that supports the extension-side stopper movably in an axial direction of the piston rod; and a bottom-side oil chamber or a rod-side oil chamber in the hydraulic actuator and the cylinder. An oil passage communicating with any one of the oil chambers, and a control valve mechanism provided in the middle of the oil passage, wherein the reduction-side stopper displacement means connects the reduction-side stopper to the piston rod. A hydraulic actuator movably supported in the axial direction, an oil through-hole communicating the hydraulic actuator with any one of the rod-side oil chamber and the bottom-side oil chamber in the cylinder, and 2. The hydraulic shock absorber according to claim 1, wherein the hydraulic shock absorber is constituted by a control valve mechanism provided. 3. The control valve mechanism communicates with the oil through hole.
The hydraulic shock absorber according to claim 2, comprising an on-off valve that shuts off, and a check valve that is provided in parallel with the on-off valve and that allows the flow of the oil liquid only from the oil chamber in the cylinder to the hydraulic actuator. .