JP3271166B2 - Cushion unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cushion unit disposed between a vehicle body and an axle of an automobile, and more particularly to a cushion unit capable of adjusting a vehicle height.

[0002]

2. Description of the Related Art Heretofore, there is a cushion unit which is arranged between a vehicle body and an axle of an automobile so that a vehicle height can be adjusted. Among them, in the invention described in Japanese Patent Application Laid-Open No. 57-192643, a cylinder spring receiver is installed on the outer periphery of a cylinder of a hydraulic shock absorber, and a rod spring receiver is installed on a piston rod via a spring receiving pressure chamber. A suspension spring is interposed therebetween. The hydraulic oil in the cylinder is fed to the spring receiving pressure chamber by the expansion and contraction movement of the hydraulic shock absorber, and the reaction force of the suspension spring is changed to adjust the vehicle height.

[0003]

In the above-described cushion unit, the hydraulic oil is not supplied to the spring receiving pressure chamber by using a hydraulic pump or the like, but the hydraulic oil is expanded and contracted by the hydraulic shock absorber in the cushion unit. The supply does not cause an increase in cost.

However, in the above-described cushion unit, the hydraulic oil in the cylinder is guided to the spring receiving pressure chamber each time the hydraulic shock absorber expands and contracts, so that the vehicle height can be adjusted even when the vehicle height adjustment is unnecessary. There is a possibility that the vehicle height cannot be selectively adjusted.

The present invention has been made in consideration of the above circumstances, and has as its object to provide a cushion unit capable of adjusting the vehicle height when necessary without increasing the cost.

[0006]

According to the present invention, there is provided a cylinder having an inner tube and an outer tube in which hydraulic fluid is filled in the inner tube and a piston is slidably disposed. A pressure chamber is defined, and a reserve chamber filled with gas and the hydraulic oil is provided between the inner tube and the outer tube, and the reserve chamber and the piston pressure chamber are communicated by a communication path, In a cushion unit in which a suspension spring is interposed between a rod spring receiver provided on a piston rod extending from the piston and a cylinder spring receiver provided on the outer tube, the communication passage is externally operated. An on-off valve provided to be openable and closable is provided, and a check valve is provided in parallel with the on-off valve, while the cylinder spring support is provided. Is provided so as to be slidable in the axial direction of the cylinder, a spring receiving pressure chamber is formed between the cylinder spring receiver and the outer tube, and the piston pressure is transmitted via the check valve when the on-off valve is closed. The chamber and the spring receiving pressure chamber are provided so as to be able to communicate with each other, and when the open / close valve is opened, the spring receiving pressure chamber and the reserve chamber are provided so as to be able to communicate through the open / close valve. An operation unit for opening and closing the valve is installed on the vehicle.

[0007]

According to the cushion unit of the present invention,
When the on-off valve is closed, the piston pressure chamber and the spring receiving pressure chamber are configured to be able to communicate with each other via the check valve, so that the hydraulic oil in the piston pressure chamber is pumped to the spring receiving pressure chamber by the reciprocating motion of the piston. Then, the cylinder spring receiver moves in the axial direction of the cylinder, and the reaction force of the suspension spring increases. Further, when the opening / closing valve is opened, the spring receiving pressure chamber and the reserve chamber are configured to be able to communicate with each other through the opening / closing valve. Therefore, the hydraulic oil in the spring receiving pressure chamber is returned to the reserve chamber, and the cylinder spring receiving chamber is returned. Moves in the axial direction of the cylinder, and the reaction force of the suspension spring decreases. When the piston rod and the cylinder are disposed between the vehicle body and the wheels, the vehicle height can be adjusted by the fluctuation of the reaction force of the suspension spring.

This vehicle height adjustment can be carried out by operating an operation unit provided on the vehicle to open and close the on-off valve, and therefore can be carried out only when it is desired to adjust the vehicle height.

Further, since the adjustment of the vehicle height is performed by supplying hydraulic oil in accordance with the reciprocating movement of the piston, the vehicle height can be adjusted without increasing the cost without the need for a hydraulic pump or the like for adjusting the vehicle height. Becomes

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing one embodiment of a cushion unit according to the present invention applied to a vehicle body. FIG.
FIG. 2 is an enlarged sectional view showing a part of the cushion unit of FIG. 1. FIG. 3 is a cross-sectional view showing the state of the switching device of FIG. FIG. 4 is a cross-sectional view showing a state in which the switching device of FIG. FIG.
FIG. 4 is a cross-sectional view showing a state in which the switching device of FIG. 3 is stopped when raising the vehicle height. FIG. 6 is a cross-sectional view illustrating a state of the switching device in FIG. 3 during a vehicle height lowering operation. 7 (A) is a side view showing the operation unit, FIG. 7 (B) is a view on arrow VIIB of FIG. 7 (A), and FIG. 7 (C) is a locking claw of FIG. 7 (A). It is a perspective view of.

As shown in FIG. 1, a cushion unit 3 is disposed between a vehicle body 1 and an axle 2 of an automobile to absorb a shock from a road surface. The cushion unit 3 has a hydraulic shock absorber 5 installed inside a suspension spring 4.
The suspension spring 4 of the cushion unit 3 absorbs the impact from the road surface, and the hydraulic shock absorber 5 attenuates the expansion and contraction movement of the cushion unit 3 due to the absorption of the impact of the suspension spring 4. The cushion unit 3 is composed of four wheels 6 of an automobile.
One axle is installed on the axle 2 near the rear wheel side, and a normal cushion unit is installed on the axle 2 near the front wheel side.

As shown in FIG. 2, the hydraulic shock absorber 5 has a cylinder 7 provided with an inner tube 8 and an outer tube 9. The inner tube 8 is filled with hydraulic oil 10 and the piston 11 slides. It is arranged movably. The inside of the inner tube 8 is defined by a piston 11 into an upper piston pressure chamber 12A and a lower piston pressure chamber 12B. A space between the inner tube 8 and the outer tube 9 is formed as a reserve chamber 13, and a hydraulic oil 10
However, gas (air) 14 is filled upward.

The bottom piece 1 is attached to the lower end of the inner tube 8.
5 is fixed, and the switching device 4
An apparatus housing 16 (described later) is fitted therein. Reducing-side communication passages 17A, 17B, and 17C are formed in the bottom piece 15 and the device housing 16, and extension-side communication passages 18 are formed in the bottom piece 15, so that the lower piston pressure chamber 12B and the reserve chamber 13 can communicate with each other. Provided.

On the other hand, the piston 11 is
The piston rod 19 extends from the cylinder 7, a rod end 20 (FIG. 1) is fixed to the end, and a rod spring receiver 21 is connected to the rod end 20. A cylinder spring receiver 22 is provided on the outer periphery of the outer tube 9 of the cylinder 7 so as to be slidable in the axial direction of the outer tube 9. These rod spring receivers 21
The suspension spring 4 is interposed between the cylinder spring receiver 22 and the cylinder spring receiver 22.

As shown in FIG. 2, the outer tube 9 is fitted on a mounting bracket 23, the cylinder 7 is supported on the axle 2 via the mounting bracket 23, and the rod end 20 is supported on the vehicle body 1. The cushion unit 3 absorbs the impact from the road surface by the suspension spring 4.
Furthermore, the cushion unit 3 mainly attenuates the expansion and contraction movement of the cushion unit 3 due to the shock absorption of the suspension spring 4 mainly by the contraction-side disk valve 24 and the first valve 26.

That is, the compression side disk valve 24 is
It is installed on the bottom piece 15 together with the extension side check valve 25. The compression side disc valve 24 is connected to the compression side communication passage 17A.
The expansion-side check valve 25 is provided so as to close the expansion-side communication passage 18. Further, the first valve 26 is installed on the piston 11 together with the second valve 27. A plurality of contraction side flow paths 28 and extension side flow paths 29 are formed in the piston 11 alternately in the circumferential direction. The first valve 26 enables the extension side flow path 29 to be closed, and the second valve 27 enables the contraction side flow path 28 to be closed.

Cushion unit 3 during normal running
In the compression process, the hydraulic oil 1 in the lower piston pressure chamber 12B
0 reaches the upper piston pressure chamber 12A via the contraction side flow path 28 and the second valve 27, and as shown by the solid arrow in FIG. Passage 17A, compression-side disc valve 24, compression-side communication passage 17B
And 17C sequentially, the hydraulic oil 10 in the lower piston pressure chamber 12B reaches the reserve chamber 13. The fluid resistance of the compression side disk valve 24 mainly generates a damping force in the compression process.

In the course of extension of the cushion unit 3 during normal running, the hydraulic oil 10 in the reserve chamber 13
However, as shown by the dashed arrow in FIG. 3, the lower piston pressure chamber 12B passes through the extension side communication passage 18 and the extension side check valve 25.
And the upper piston pressure chamber 12A shown in FIG.
Hydraulic oil 10 in the inside reaches the lower piston pressure chamber 12B via the extension side flow path 29 and the first valve 26. The fluid resistance of the first valve 26 mainly generates a damping force in the extension process.

As shown in FIG. 2, a partition member 30 is provided on the inner surface of the cylinder spring receiver 22.
Are fitted so as to be relatively movable in the axial direction. The partition member 30 is fixed to and supported by the outer tube 9 via the support tube 31. The partition member 30 forms a spring receiving pressure chamber 32 between the cylinder spring receiver 22 and the outer tube 9. This spring receiving pressure chamber 32
The lower piston pressure chamber 12B is provided so as to be able to communicate with the lower piston pressure chamber 12B via a hydraulic oil introduction passage 33 between the outer tube 9 and the support tube 31, a check valve 43 described later, and the like. Partition member 30
Further, an oil seal 34 is provided between the cylinder spring receiver 22 and the spring receiving pressure chamber 32 is configured in a sealed structure.

An air vent passage 35 is formed in the cylinder spring receiver 22 so as to communicate with the spring receiving pressure chamber 32.
A closing plug 36 as a closing means is provided in the air vent passage 35.
Is screwed. At the time of assembling the cushion unit 3, the stopper plug 36 is removed, and the air in the spring receiving pressure chamber 32 is extracted, whereby the inside of the spring receiving pressure chamber 32 is filled only with the hydraulic oil 10. Note that a dust seal 37 is supported by a seal member 38 at the lower end of the cylinder spring receiver 22. Reference numeral 39 indicates a bush.

As shown in FIGS. 2 and 3, a switching device 40 is provided at the lower end of the outer tube of the cylinder 7. The switching device 40 includes an upper opening / closing valve 41
And a lower opening / closing valve 42 is installed vertically adjacent to each other, and a check valve 43 and a relief valve 44 are further installed.

The upper on-off valve 41 opens and closes an on-off valve seat 45 disposed between the compression side communication passages 17B and 17C in the device housing 16. Also, the lower opening / closing valve 42
Is for opening and closing the upper open / close valve passage 46 formed in the upper open / close valve 41. The upper opening / closing valve 41 and the lower opening / closing valve 42 are operated by an operating sleeve 48 biased by an opening / closing valve spring 47.
The upper opening / closing valve 41 abuts on the opening / closing valve seat 45 to close between the contraction side communication passages 17B and 17C, and the lower opening / closing valve 42 acts to close the upper opening / closing valve flow path 46.

The operating sleeve 48 is slidably disposed in a sleeve housing 49, and an opening / closing valve spring 47 is interposed between the operating sleeve 48 and the sleeve housing 49. The sleeve housing 49 is screwed into the device housing 16 and fixed with a lock nut 50. One end of an operation wire 51 is locked to the operation sleeve 48, and the other end of the operation wire 51 is connected to an operation section 70 (described later) of a driver's seat or a bed. The operation wire 51 is covered and protected by the wire tube 52.

The operation section 70 has an operation lever 71 and an operation claw 72 as shown in FIGS. 7 (A), 7 (B) and 7 (C).

The operation lever 71 is rotatably supported on a driver's seat or a bed of the vehicle body 1 around a pin 73. Also,
The operation lever 71 has a locking portion 7 at the end opposite to the pin 73.
4 and a connecting wire 75 is connected to a central position. The connection wire 75 is connected to both the operation wire 51 for the cushion unit 3 arranged on the left rear wheel and the operation wire 51 for the cushion unit 3 arranged on the right side of the rear wheel.

The operation claw 72 includes a claw portion 76 and a shaft portion 77.
The shaft 77 is rotatably supported by the vehicle body 1. An operation spring 78 is interposed between the operation claw 72 and the vehicle body 1, and the claw portion 76 of the operation claw 72 is engaged with the locking portion 74 of the operation lever 71 by the urging force of the operation spring 78.

At the time of engagement between the pawl portion 76 and the locking portion 74, the connecting wire 75 and the operating wire 51 are connected to each other as shown in FIGS.
The upper opening / closing valve 41 is opened by being pulled in the direction of the arrow A of (A). At this time, the lower opening / closing valve 42 is opened or closed depending on the pressure relationship between the lower piston pressure chamber 12B and the spring receiving pressure chamber 32, as described later. In addition, the claw portion 76
Is released from the locking portion 74, the connecting wire 75 and the operation wire 51 are moved in the direction opposite to the arrow A by the urging force of the on-off valve spring 47, and the upper on-off valve 41
And the lower opening / closing valve 42 is closed. Claw portion 76 and locking portion 7
Engagement and disengagement with 4 are performed manually or using a solenoid valve or the like.

Claw section 76 of operation claw 72 in operation section 70
Engages with the locking portion 74 of the operation lever 71, and the operation wire 51 is pulled in the direction of arrow A in FIG. 3, whereby the upper opening / closing valve 41 is acted upon by the pressure of the hydraulic oil 10 in the lower piston pressure chamber 12B. Is separated from the on-off valve seat 45, and the contraction side communication passages 17B and 17C are in a communicating state. At this time, the lower on-off valve 4
Reference numeral 2 indicates that when the pressure of the hydraulic oil 10 in the lower piston pressure chamber 12B is larger than the pressure of the spring receiving pressure chamber 32, the upper on-off valve flow path 46 is closed. Also, the spring receiving pressure chamber 32
When the pressure of the hydraulic oil 10 in the inside is larger than the pressure of the lower piston pressure chamber 12B, the lower on-off valve 42 opens the upper on-off valve flow path 46 as shown in FIG. The receiving pressure chamber 32 and the reserve chamber 13 are brought into communication.

Further, in the device housing 16 shown in FIG. 3, branch passages 52A and 52B are branched from the contraction side communication passage 17B, and a check valve seat 53 is provided between the branch passages 52A and 52B. . The branch flow path 52 </ b> B further communicates with a branch groove 56 and a branch hole 57 formed in the outer tube 9, and the branch hole 57 communicates with the hydraulic oil introduction path 33. The check valve 43 opens and closes the check valve seat 53, and is therefore arranged in parallel with the upper and lower valves 41 and 42. The check valve 43 is slidably fitted on a check valve sleeve 54 screwed into the device housing 16. The check valve 43 has a cylindrical shape with a cover, and the check valve 4
A check valve spring 55 is interposed between the inside 43A of the third member 3 and the check valve sleeve 54. Further, the inside 43 of the check valve 43
A is communicated with the branch channel 52B by the passage 58.

Accordingly, the check valve 43 is caused by the urging force of the check valve spring 55 and the pressure of the hydraulic oil 10 in the spring receiving pressure chamber 32 acting on the inside 43A through the passage 58. To close between the branch flow paths 52A and 52B. Further, as shown in FIG. 4, the upper opening / closing valve 41 and the lower opening / closing valve 42 are closed, and the hydraulic oil 10 in the lower piston pressure chamber 12B flows into the branch flow path 52A. When the hydraulic oil 10 becomes larger than the urging force of the check valve spring 55 and the pressure of the hydraulic oil 10 in the spring receiving pressure chamber 32, the check valve 43 opens.

Relief channels 59A and 59B are formed in the apparatus housing 16 shown in FIG. The relief flow path 59A communicates with the contraction side communication path 17B, and the relief flow path 5
9B is communicated with the reserve chamber 13. A relief hole 60 is opened between these relief channels 59A and 59B. The relief valve 44 can open and close the relief hole 60.

The relief valve 44 is slidably mounted on the apparatus housing 16 via a relief valve spring 62 between the relief valve 44 and a relief valve plate 61 locked on the apparatus housing 16. A flange 63 is formed in the relief valve 44, and a relief valve operating hole 64 is formed in the device housing 16 at a position corresponding to the flange 63. The relief valve operation hole 64 opens in the branch groove 56 of the outer tube 9. Therefore, when the pressure of the hydraulic oil 10 in the spring receiving pressure chamber 32 becomes equal to or higher than a predetermined value, this pressure passes through the hydraulic oil introduction passage 33, the branch hole 57, the branch groove 56, and the relief valve operation hole 64, and the flange portion. Acting on 63, the relief valve 44 slides against the relief valve spring 62 and opens as shown in FIG.

Next, the function and effect will be described. [A] During normal running (FIG. 3) The operating portion 70 in the driver's seat or the carrier is operated to engage the claw portion 76 of the operating claw 72 with the locking portion 74 of the operating lever 71, and the operating wire 51 is 3. Pull in the direction of arrow A. Then, the operating sleeve 48 moves downward in the figure against the urging force of the opening / closing valve spring 47, and the upper opening / closing valve 41 and the lower opening / closing valve 42 move downward due to the pressure of the operating oil 10 in the lower piston pressure chamber 12B. Then, the upper opening / closing valve 41 is opened.
The lower opening / closing valve 42 is closed. As a result, the lower piston pressure chamber 12B is connected to the contraction side communication passages 17A, 17B and 17B.
It communicates with the reserve chamber 13 via C.

In the compression process of the hydraulic shock absorber 5 in the cushion unit 3, the piston 11 (FIG. 2) relatively moves toward the lower piston pressure chamber 12B, and the hydraulic oil 10 in the lower piston pressure chamber 12B As shown by the solid line arrow in FIG. 3, the compression-side communication passage 17B and the on-off valve seat 45 are bent while deforming the compression-side disc valve 24 through the compression-side communication passage 17A.
Then, it moves into the reserve chamber 13 via the contraction side communication passage 17C. At this time, at the same time, the hydraulic oil 10 in the lower piston pressure chamber 12 </ b> B
The valve 27 is opened to move into the upper piston pressure chamber 12 </ b> A. The damping force in the compression process is mainly generated by the compression-side disk valve 24.

In the extension process of the hydraulic shock absorber 5 in the cushion unit 3, the piston 11 (FIG. 2) relatively moves toward the upper piston pressure chamber 12A, and the hydraulic oil 10 in the reserve chamber 13 is displaced by a broken line in FIG. As indicated by the arrow, the expansion-side check valve 25 is opened via the expansion-side communication passage 18, and flows into the lower piston pressure chamber 12B. At this time, the hydraulic oil 10 in the upper piston pressure chamber 12A (FIG. 2)
The first valve 26 is bent and deformed through the first extension flow path 29 and flows into the lower piston pressure chamber 12B. The bending deformation of the first valve 26 mainly generates a damping force in a damping process.

[B] Traveling while raising the vehicle height (FIG. 4) When the rear of the vehicle is lowered and it is desired to return the vehicle to the horizontal position, the operation unit 70 provided on the driver's seat or the carrier is operated to operate the operation claw 7.
Remove the second claw portion 76 from the locking portion 74 of the operation lever 71,
The pulling operation of the operation wire 51 is released. Then, the operating sleeve 48 presses the lower open / close valve 42 and the upper open / close valve 41 upward in FIG. 4 by the urging force of the open / close valve spring 47, and the upper open / close valve 41 comes into contact with the open / close valve seat 45 to close the valve. Become. At this time, the lower opening / closing valve 42 also keeps the valve closed state. Depending on the closed state of the upper opening / closing valve 41, the communication between the contraction side communication passages 17B and 17C is cut off.

Accordingly, in the process of compressing the hydraulic shock absorber 5 in the cushion unit 3, the hydraulic oil 10 in the lower piston pressure chamber 12B flexes and deforms the compression-side disk valve 24 as shown by the solid line arrow in FIG. While generating a damping force, it reaches the inside of the branch passage 52A from the contraction side communication passage 17B. When the pressure of the hydraulic oil 10 in the branch passage 52A becomes larger than the urging force of the check valve spring 55 and the pressure of the hydraulic oil 10 in the spring receiving pressure chamber 32, the check valve 43 opens. I do. As a result, the hydraulic oil in the lower piston pressure chamber 12B that has reached the branch flow path 52A is introduced from the branch flow path 52B into the hydraulic oil introduction path 33 through the branch groove 56 and the branch hole 57, and into the spring receiving pressure chamber 32. To be pumped. When the hydraulic oil 10 is fed into the spring receiving pressure chamber 32, the cylinder spring receiver 22 moves upward in FIG.
Is compressed.

During the extension of the hydraulic shock absorber 5 in the cushion unit 3, the hydraulic oil 10 in the spring receiving pressure chamber 32 is
Of the check valve 4 through the passage 58 from the branch flow path 52B.
3 acts on the inside 43A, and the check valve 43 maintains the closed state. For this reason, the hydraulic oil in the reserve chamber 13 flows into the lower piston pressure chamber 12B via the extension side communication passage 18 as shown by a broken arrow in FIG. For this reason, in the extension process of the hydraulic shock absorber 5, the compression state of the suspension spring 4 in the compression process performed before that is maintained.

The suspension spring 4 is gradually compressed by the repetition of the compression process and the extension process of the hydraulic shock absorber 5 described above,
The height of the vehicle increases due to an increase in the spring reaction force, and the rear portion of the vehicle eventually becomes horizontal with the front portion. In the process of compressing or expanding the hydraulic shock absorber 5, the flow of the hydraulic oil in the expansion side flow path 28 and the compression side flow path 29 of the piston 11 and the deformation of the first valve 26 and the second valve 27 are described. Is the same as during the normal running.

[C] When the vehicle height is stopped (FIG. 5) When the cylinder spring receiver 22 of the suspension spring 4 rises to a predetermined position during the vehicle height raising travel described in [B], the pressure in the spring receiving pressure chamber 32 is increased. The pressure reaches a predetermined value. When the pressure in the spring receiving pressure chamber 32 reaches the predetermined value, as shown by the solid line arrow in FIG. 5, the hydraulic oil introduction passage 33, the branch hole 57, the branch groove 56
Then, it acts on the flange portion 63 of the relief valve 44 via the relief valve operation hole 64, and moves the relief valve 44 downward in FIG. 4 to open the relief valve 44.

Then, in the compression process of the hydraulic shock absorber 5 in the cushion unit 3, the hydraulic oil 10 in the lower piston pressure chamber 12B does not flow to the branch flow path 52A, but to the extension side communication path 1A.
The relief flow channel 59A, the relief hole 60, and the relief flow channel 59B sequentially flow from 7A and the extension side communication passage 17B, and are guided to the reserve chamber 13. Therefore, in the compression process and the expansion process of the hydraulic shock absorber 5, the hydraulic shock absorber 5 performs the same damping function as in the normal traveling of [A], and the vehicle height is maintained in the rising state.

[D] Car Height Lowering Operation (FIG. 6) When it is desired to unload luggage or the like from the car carrier and lower the rear part of the raised vehicle, the operation unit 7 in the driver's seat or the carrier.
0 to operate the claw portion 76 of the operation claw 72
The operation wire 51 is pulled in the direction of arrow A in FIG. At this time, the hydraulic oil 10 in the spring receiving pressure chamber 32 reaches the hydraulic oil introduction path 33, the branch hole 57, the branch groove 56, and the branch flow path 52B as shown by the solid arrow in FIG. It reaches the flow path 65. Then, the lower opening / closing valve 42 is lowered to the position of the operating sleeve 48 which is lowered downward in FIG. 6 against the urging force of the opening / closing valve spring 47 by the wire operation, and the lower opening / closing valve 42 is opened. In this state, the hydraulic oil 10 that has reached the flow path 65 is guided into the upper open / close valve flow path 46 of the upper open / close valve 41, and
It flows into the reserve chamber 13 from 7C.

As described above, when the pressure of the hydraulic oil 10 in the spring receiving pressure chamber 32 decreases, the cylinder spring receiving 22
Descends, and the rear of the vehicle descends to the original position. When the pressure in the spring receiving pressure chamber 32 decreases, the relief valve 4
4 flange portion 63 and upper open / close valve 41 and upper open / close valve flow path 4
Since the pressure acting on the valve 6 also decreases, the relief valve 41 and the upper opening / closing valve 41 return to the state at the time of the normal traveling of [A].

[E] Effect According to the above embodiment, the operation lever 71 and the operation claw 72 of the operation unit 70 are operated to release the pulling operation of the operation wire 51, and the upper open / close valve 41 and the lower open / close valve 42 are closed. When operated, the check valve 43 is opened, and the contraction side communication passages 17A and 17B, the branch passages 52A and 52B, the branch groove 56, and the branch hole 5 are opened.
7 and the hydraulic oil introduction passage 33, the lower piston pressure chamber 12
B and the spring receiving pressure chamber 32 are in communication with each other, so that the hydraulic oil 10 in the lower piston pressure chamber 12B is pressure-fed into the spring receiving pressure chamber 32 by the expansion and contraction movement of the hydraulic shock absorber 5 in the cushion unit 3, and The spring receiver 22 rises. As a result, the spring reaction force of the suspension spring 4 increases, and the rear part of the vehicle can be raised.

Since the vehicle height adjustment is performed only by supplying the hydraulic oil 10 in accordance with the expansion and contraction movement of the hydraulic shock absorber 5, a hydraulic pump for adjusting the vehicle height is not required, and the vehicle height is adjusted without increasing the cost. Can be adjusted.

In order to adjust the vehicle height, the operating wire 51 is operated by operating the operating lever 71 and the operating claw 72 of the operating section 70 installed in the driver's seat, the loading platform, etc. It is done by selecting the opening and closing of 42,
Vehicle height adjustment can be performed only when necessary.

Further, when the stopper plug 36 is removed at the time of assembling the cushion unit 3 and the air is extracted from the spring receiving pressure chamber 32 through the air release passage 35, the lower piston pressure chamber 12B is introduced into the spring receiving pressure chamber 32. The hydraulic oil 10 can be supplied smoothly, and the inside of the spring receiving pressure chamber 32 can be filled with the hydraulic oil 10 alone. As a result, the hydraulic oil 10 that is pressure-fed along with the expansion and contraction of the hydraulic shock absorber 5 causes
The cylinder spring receiver 22 can be slid smoothly and reliably, and the vehicle height can be adjusted reliably.

FIG. 8 is a hydraulic circuit diagram showing a hydraulic shock absorber switching device in another embodiment of the cushion unit according to the present invention. In the other embodiments, the same parts as those in the above embodiment are denoted by the same reference numerals, and the description is omitted.

In the switching device 80 according to the other embodiment, the operating sleeve 48 is integrated with the solenoid valve 81, and the upper and lower valves 41 and 42 are opened and closed by the solenoid valve 81. Therefore, the operation unit 70 installed on the driver's seat or the bed of the vehicle body 1 excites or demagnetizes the electromagnetic valve 81 to open and close the upper opening and closing valve 41 and the lower opening and closing valve 42.

That is, in the switching device 80, the operation unit 7
0, and the solenoid valve 81 is demagnetized, the upper opening / closing valve 41 is opened, and during the compression process of the cushion unit 3, the hydraulic oil 10 in the lower piston pressure chamber 12B flows into the compression side communication passage 17B.
Flows through the upper opening / closing valve 41 and the contraction side communication passage 17C to the reserve chamber 13, and in the extension process, flows from the reserve chamber 13 to the lower piston pressure chamber 12B via the extension side communication passage 18. At this time, the lower on-off valve 42 is in the non-communication state (close operation state) since the check valve 43 is in the closed state.

When the operation unit 70 is operated to excite the solenoid valve 81 to raise the rear part of the vehicle body 1, the upper and lower opening / closing valves 41 and 42 are closed, and during the compression process of the cushion unit 3, the check valve is closed. 43 is opened, and the hydraulic oil 10 in the lower piston pressure chamber 12B flows into the branch passage 52A, the check valve 4
3, the branch passage 52B, the branch groove 56, the branch hole 57, and the hydraulic oil introduction passage 33 are guided to the spring receiving pressure chamber 32, and the rear portion of the vehicle body 1 is raised.

When the pressure in the spring receiving pressure chamber 32 reaches a predetermined pressure, the pressure of the hydraulic oil 10 in the spring receiving pressure chamber 32 acts on the flange portion 63 of the relief valve 44 through the relief valve operating hole 64, and this relief The valve 44 is opened. Therefore, after that, during the compression process of the cushion unit 3, the hydraulic oil 10 in the lower piston pressure chamber 12B is
B, the relief flow path 59A, the relief valve 44, the relief hole 60, and the relief flow path 59B are guided to the reserve chamber 13 through the relief flow path, whereby the ascending state of the rear portion of the vehicle body 1 is maintained at the current state.

When lowering the rear part of the vehicle body 1, the operation unit 7
0, the electromagnetic valve 81 is demagnetized, and the upper and lower valves 41 and 42 are opened. Then, the spring receiving pressure chamber 32
The hydraulic oil 10 is guided to the reserve chamber 13 through the hydraulic oil introduction path 33, the branch hole 57, the branch groove 56, the branch flow path 52B, the flow path 65, the lower opening / closing valve 42, and the contraction side flow path 17C. The rear of descends. At this time, the cushion unit 3
During the compression process, the hydraulic oil 10 in the lower piston pressure chamber 12B
Are the contraction side communication passage 17B, the upper opening / closing valve 41 and the contraction side communication passage 1
It is guided to the reserve chamber 13 via 7C and does not contribute to the rise of the rear part of the vehicle body 1.

According to the second embodiment, since the operating section 70 electrically operates the upper and lower opening / closing valves 41 and 42,
The structure around the operation unit 70 can be simplified. In addition, the second embodiment has the same effects as the first embodiment.

In both of the above embodiments, the cushion unit is installed between the rear wheel-side axle 2 and the vehicle body 1, but the cushion unit 3 is mounted on the axle 2 near the four wheels 6. You may install a total of four one by one.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and the design may be changed without departing from the scope of the present invention. Even if present, it is included in the present invention.

[0057]

As described above, according to the cushion unit of the present invention, the vehicle height can be adjusted when necessary without increasing the cost.

[Brief description of the drawings]

FIG. 1 is a front view showing one embodiment of a cushion unit according to the present invention applied to a vehicle body.

FIG. 2 is an enlarged sectional view showing a part of the cushion unit of FIG. 1;

FIG. 3 is a cross-sectional view illustrating the switching device of FIG. 2 in a further enlarged state in a state of normal traveling.

FIG. 4 is a cross-sectional view showing a state in which the switching device of FIG. 3 travels while raising the vehicle height.

FIG. 5 is a cross-sectional view showing a state in which the switching device of FIG. 3 is stopped when raising the vehicle height.

FIG. 6 is a cross-sectional view showing a state at the time of a vehicle height lowering operation of the switching device of FIG. 3;

FIG. 7A is a side view showing an operation unit, and FIG.
(B) is a view on arrow VIIB of FIG. 7 (A), and FIG. 7 (C)
FIG. 8 is a perspective view of the locking claw of FIG.

FIG. 8 is a hydraulic circuit diagram showing a hydraulic shock absorber switching device in another embodiment of the cushion unit according to the present invention.

[Description of Signs] 3 Cushion unit 4 Suspension spring 5 Hydraulic shock absorber 7 Cylinder 8 Inner tube 9 Outer tube 10 Hydraulic oil 11 Piston 12B Lower piston pressure chamber 13 Reserve chamber 14 Gas 16 Device housing 17A, 17B, 17C Compression side communication passage 18 Extension side communication path 21 Lot spring receiver 22 Cylinder spring receiver 30 Partition member 32 Spring receiving pressure chamber 33 Hydraulic oil introduction path 35 Air vent path 36 Closure plug 40 Switching device 41 Upper open / close valve 42 Lower open / close valve 43 Check valve 44 Relief valve 45 On-off valve valve seat 48 Operating sleeve 51 Operating wire 52A, 52B Branch flow path 53 Check valve seat 56 Branch groove 57 Branch hole 59A, 59B Relief flow path 60 Relief hole 63 Relief valve flange 64 Relief valve operating hole 70 Operation unit 71 Operation lever 72 Sakutsume

Claims (6)

(57) [Claims] A cylinder having an inner tube and an outer tube is filled with hydraulic oil in the inner tube, and a piston is slidably disposed on the inner tube.
One piston pressure chamber is defined, and a reserve chamber filled with gas and the hydraulic oil is provided between the inner tube and the outer tube, and the reserve chamber and the piston pressure chamber are communicated by a communication passage. A cushion spring in which a suspension spring is interposed between a rod spring receiver disposed on a piston rod extending from the piston and a cylinder spring receiver disposed on the outer tube; An on-off valve provided to be openable and closable is installed, and a check valve is installed in parallel with the on-off valve, while the cylinder spring receiver is provided so as to be slidable in the axial direction of the cylinder, A spring receiving pressure chamber is formed between the cylinder spring receiving and the outer tube, and the pin is set via the check valve when the on / off valve is closed. The ton pressure chamber and the spring receiving pressure chamber are provided so as to be able to communicate with each other, and the spring receiving pressure chamber and the reserve chamber are provided so as to be able to communicate with each other via the on-off valve when the on-off valve is opened. A cushion unit, wherein an operation unit for opening and closing the open / close valve is installed in a vehicle. 2. A relief valve is provided between the piston pressure chamber and the reserve chamber, and operates when the pressure of the spring receiving pressure chamber becomes equal to or higher than a predetermined pressure, so that the piston pressure chamber and the reserve chamber can communicate with each other. The cushion unit according to claim 1, wherein the cushion unit is provided in the cushion unit. 3. The cushion unit according to claim 1, wherein the operation unit is installed on a driver's seat or a bed of the vehicle. 4. The cushion unit according to claim 1, wherein the operation unit is connected to the on-off valve via a wire. 5. The cushion unit according to claim 1, wherein the on-off valve is openable and closable by an operation of an electromagnetic valve, and an operation unit operates the on-off valve via the electromagnetic valve. 6. The cushion unit according to claim 1, wherein the cushion unit is provided between the vehicle rear wheel and the vehicle body.