JP3332577B2 - 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 provides a cushion unit capable of adjusting the vehicle height as needed without increasing the cost and setting the vehicle height at an arbitrary position. The purpose is to provide.

[0006]

According to the first aspect of the present invention, the inner tube of a cylinder having an inner tube and an outer tube is filled with hydraulic oil and a piston is slidably disposed. And two piston pressure chambers are 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 with each other by a communication passage. In the cushion unit, 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 that can be opened and closed by an external electric drive means is installed, and a check valve is installed in parallel with the on-off valve. A cylinder spring receiver is provided slidably in the axial direction of the cylinder, and a spring receiving pressure chamber is formed between the cylinder spring receiver and the outer tube. The piston 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 through the open / close valve when the open / close valve is opened. A reserve valve that can be opened and closed by an external electric drive means is provided between the piston pressure chamber and the reserve chamber, so that when the reserve valve is opened, the hydraulic oil in the piston pressure chamber can be led to the reserve chamber. It is characterized by having been constituted.

[0007] The invention described in claim 2 is the first invention.
A vehicle height sensor is provided in the cushion unit described in
A vehicle height setting device is installed in the vehicle, and the vehicle height control device is configured to control the opening / closing operation of the on-off valve and the relief valve based on signals from the vehicle height sensor and the vehicle height setting device.

[0008]

According to the first aspect of the present invention, the piston pressure chamber and the spring receiving pressure chamber can communicate with each other via the check valve when the on-off valve is closed. Due to the reciprocating motion of the piston, the operating oil in the piston pressure chamber is pressure-fed to the spring receiving pressure chamber, the cylinder spring receiver moves in the axial direction of the cylinder, and the reaction force of the suspension spring increases. Further, when the on-off valve is opened, the spring receiving pressure chamber and the reserve chamber are configured to be able to communicate with each other via the on-off valve, so that the operating 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,
The reaction force of the suspension spring is reduced. 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.

Since the vehicle height is adjusted by supplying hydraulic oil in accordance with the reciprocating movement of the piston, a vehicle height adjustment hydraulic pump or the like is not required, and the vehicle height can be adjusted without increasing the cost. .

The vehicle height can be adjusted by opening and closing the on-off valve and the relief valve by an external electric drive means.
Moreover, the vehicle height can be adjusted to any position.

Further, according to the second aspect of the present invention, the vehicle height control device controls the opening and closing operations of the on-off valve and the relief valve based on signals from the vehicle height sensor and the vehicle height setting device. The height can be automatically adjusted to the height set by the vehicle height setting device.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a front view showing a cushion unit according to the present invention applied to a vehicle body, and FIG.
FIG. 2 is a block diagram showing a control system of the cushion unit in FIG. FIG. 2 is an enlarged sectional view showing a part of the cushion unit of FIG. FIG. 3 is a cross-sectional view illustrating the switching device of FIG. 2 in a further enlarged state, showing a state where the vehicle is descended most (a state during normal traveling). FIG. 4 is a sectional view showing the switching device of FIG. 3 when the vehicle height is rising. FIG. 5 is a cross-sectional view showing a vehicle height rising stop state and a vehicle lowering stop state of the switching device of FIG. 3. FIG. 6 is a cross-sectional view illustrating the switching device of FIG. FIG. 7 is a sectional view showing the switching device of FIG. 3 when the vehicle height is decreasing. FIG. 8 is a flowchart showing the control of the vehicle height control device of FIG. FIG. 9 is a sectional view showing the vehicle height sensor. FIG. 10 is a cross-sectional view showing a modification of the electric driving means.

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 includes 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 has a piston rod 19
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 disc 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.

In the compression process of the cushion unit 3 during normal running (in the lowest state of the vehicle), the hydraulic oil 10 in the lower piston pressure chamber 12B flows through the contraction side flow path 28 and the second valve 27 to the upper piston pressure chamber 12A. As well as inside
As shown by the solid arrow in FIG. 3, the upper opening / closing valve 41 described later is opened to open the expansion-side communication passage 17A and the compression-side disc valve 2.
4. The hydraulic oil 10 in the lower piston pressure chamber 12B reaches the reserve chamber 13 sequentially through the contraction side communication passages 17B and 17C. 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 (in the lowest state of the vehicle height), the hydraulic oil 10 in the reserve chamber 13 is displaced as shown by the dashed arrow in FIG.
The hydraulic oil 10 in the upper piston pressure chamber 12A shown in FIG. 2 passes through the expansion-side flow path 29 and the first valve 26 through the expansion-side communication passage 18 and the expansion-side check valve 25 into the lower piston pressure chamber 12B. It reaches the inside of the lower piston pressure chamber 12B. 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 opening / closing valve 41 opens and closes an opening / closing valve valve seat 45 disposed between the compression side communication passages 17B and 17C in the apparatus 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 open / close valve 41 abuts (closes) on the open / close valve seat 45 to close between the contraction side communication passages 17B and 17C, and the lower open / close valve 42 closes the upper open / close valve flow path 46 (closed valve). ).

The operating sleeve 48 is slidably disposed in the sleeve housing 49,
9 is integrated with an on-off valve solenoid 50 as an electric drive means. An on-off valve spring 47 is interposed between the operation sleeve 48 and the sleeve housing 49. Here, the cylinder bracket 5 is attached to the lower end of the outer tube 9.
1A is fixed, and the on-off valve solenoid 50 is supported by a bracket cover 51B attached to the cylinder bracket 51A. The first plunger 51 of the on-off valve solenoid 50 is locked to the operation sleeve 48.

In the energized state of the on-off valve solenoid 50,
As described above, the upper opening / closing valve 41 and the lower opening / closing valve 42 are closed by the action of the urging force of the opening / closing valve spring 47.
In the direction of arrow A. Thus, when the first plunger 51 is pulled in the direction of arrow A, the lower piston pressure chamber 12
The upper opening / closing valve 41 separates from the opening / closing valve seat 45 (opens) by the action of the pressure of the hydraulic oil 10 in B, and the contraction side communication passages 17B and 17
C enters the communication state. At this time, the lower on-off valve 42 is
When the pressure of the hydraulic oil 10 in the lower piston pressure chamber 12B is higher than the pressure of the spring receiving pressure chamber 32, the upper on-off valve flow path 4
When the pressure of the hydraulic oil 10 in the spring receiving pressure chamber 32 is larger than the pressure of the lower piston pressure chamber 12B, the upper open / close valve flow path 46 is opened as shown in FIG. State (valve open). Reference numeral 67 denotes an electric wire that supplies power to the on-off valve solenoid 50.

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.

In the apparatus housing 16 shown in FIG. 3, relief channels 59A and 59B are formed. 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 includes a relief valve plate 6
1 is slidably installed in the apparatus housing 16 via a relief valve spring 62. The relief valve plate 61 is integrated with a relief valve solenoid 70 as an electric driving means.
0 is locked to the cylinder bracket 51A. 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. Further, the relief valve solenoid 70 includes a second plunger 71, which is engaged with and fixed to the relief valve 44. An oil hole 72 is formed in the second plunger 71 so that the hydraulic oil 10 can flow in and out of the relief valve 44.

In the non-excited state of the relief valve solenoid 70, when the pressure of the hydraulic oil 10 in the spring receiving pressure chamber 32 becomes a predetermined value or more, this pressure is increased to the hydraulic oil introduction passage 33, the branch hole 57, the branch groove 56. And acts on the flange portion 63 via the relief valve operating hole 64, and the relief valve 44 slides against the relief valve spring 62 and opens as shown in FIG. When the relief valve solenoid 70 is excited, the second plunger 71 is pulled in the direction of arrow B in FIG.
As a result, the relief valve 44 opens as shown in FIG. Reference numeral 66 denotes an electric wire that supplies power to the relief valve solenoid 70.

Now, the switching device 4 configured as described above.
0, the spring receiving pressure chamber 32 shown in FIG.
When the hydraulic oil 10 is pressure-fed inside, the suspension spring 4 is compressed to increase the vehicle height, and the hydraulic oil 10 is discharged from the spring receiving pressure chamber 32 to lower the vehicle height. here,
The spring receiving pressure chambers 32 of the cushion unit 3 installed one by one on the axle 2 near the rear wheel side are connected by a communication pipe 72 as shown in FIG. High balance is ensured.

In the above-described vehicle height adjustment, the vehicle height control device 73 shown in FIG. 1 (B) converts the set height signal a from the vehicle height setting device 74 and the sensor output signal b from the vehicle height sensor 75. In comparison, the on / off valve solenoid 50 of the switching device 40 is excited,
The operation is performed by outputting a signal c for the on-off valve solenoid to be de-energized and a signal d for the relief valve solenoid to excite and de-energize the relief valve solenoid 70. That is, as shown in FIG. 8, the vehicle height raising operation is performed by de-energizing the on-off valve solenoid 50 and the relief valve solenoid 70 (FIG. 4), and the vehicle height lowering operation is performed by turning the on-off valve solenoid 50 and the relief valve solenoid 70 on. This is done by exciting (FIG. 7). Further, when the vehicle height is raised or lowered, the vehicle height is stopped at the set height of the vehicle height setting device 74 by deenergizing the on-off valve solenoid 50 and energizing the relief valve solenoid 70 ( (Fig. 5).

Here, the vehicle height setting device 74 is installed at a position where the driver can easily operate it, such as a driver's seat at a vehicle height or a bed. The vehicle height sensor 75 is installed between the outer wall of the support tube 31 and the inner wall of the cylinder spring 22, as shown in FIG. This vehicle height sensor 75 is, for example, as shown in FIG.
As shown in FIG. 2A, the structure includes a permanent magnet 76 fixed to the partition member 30 and a magnetoelectric element 77 embedded in the seal member 38. When adjusting the vehicle height, adjust the cylinder spring support 2
When 2 moves relative to support tube 31 and partition member 30, magnetoelectric element 77 detects a change in the magnetic flux density from permanent magnet 76 and detects the vehicle height at that time.

Next, the control of the vehicle height control device 73 will be described with reference to FIG.
This will be described in detail with reference to FIG. (A) Vehicle lowering state (normal traveling, FIG. 3) When the vehicle height is lowered, the vehicle height control device 73 excites the on-off valve solenoid 50 to pull the first plunger 51 in the direction of arrow A and to release the relief. The valve solenoid 70 is de-energized. Then, the operating sleeve 48 moves downward in the figure against the urging force of the on-off valve spring 47, and the upper on-off valve 4
1 and the lower opening / closing valve 42 move downward by the pressure of the hydraulic oil 10 in the lower piston pressure chamber 12B, and the upper opening / closing valve 41 is opened and the lower opening / closing valve 42 is closed. Thereby, the lower piston pressure chamber 12B is connected to the contraction side communication passage 17A,
It communicates with the reserve chamber 13 via 17B and 17C.

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) When the vehicle height rises (FIG. 4) When it is desired to raise the vehicle height to a predetermined height, the driver sets the vehicle height setting device 74 to that height. At this time, the vehicle height control device 73 sets the on-off valve solenoid 50 to the non-excited state while maintaining the relief valve solenoid 70 in the non-excited state. 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 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 process 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 repeating the compression process and the extension process of the hydraulic shock absorber 5 described above,
The spring reaction force increases and the vehicle height rises, and eventually the vehicle height detected by the vehicle height sensor 75 matches the set height set by the vehicle height setting device 74. In the process of compressing or expanding the hydraulic shock absorber 5, the flow of hydraulic oil in the expansion side flow path 28 and the compression side flow path 29 of the piston 11,
Regarding the deformation of the first valve 26 and the second valve 27,
This is the same as during normal running.

(C) Vehicle Height Rising Stop State (FIG. 5) When the vehicle height matches the vehicle height set by the vehicle height setting device 74, the vehicle height control device 73 sets the on-off valve solenoid 50 to a non-excited state. The relief valve solenoid 70 is excited and the relief valve 44 is opened while the upper and lower valves 41 and 42 are kept closed. Then, 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 12 </ b> B
And flows sequentially through the relief flow path 59A, the relief hole 60, and the relief flow path 59B from the extension side communication path 17A and the extension side communication path 17B, and is guided to the reserve chamber 13. 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 running of (A),
The vehicle height is maintained at the set height.

(D) Maximum vehicle height (FIG. 6) When it is desired to raise the vehicle height to the maximum height, the driver must
The vehicle height setting device 74 is set to the highest height. When the cylinder spring receiver 22 rises to the highest height during the vehicle height rise described in (B), the pressure in the spring bearing pressure chamber 32 reaches a predetermined value. The pressure in the spring receiving pressure chamber 32 that has reached the predetermined value is:
As shown by the solid arrows in FIG. 6, it acts on the flange portion 63 of the relief valve 44 through the hydraulic oil introducing furnace 33, the branch hole 57, the branch groove 56, and the relief valve operation hole 64, and the relief valve 44 is moved to the position shown in FIG. By moving the relief valve 44 downward, the relief valve 44 is opened.

Therefore, also in this case, during the compression process of the hydraulic shock absorber 5, the hydraulic oil 10 in the lower piston pressure chamber 12B becomes
Similarly to (C), it flows through the relief hole 60 and the like, is guided to the reserve chamber 13, and is maintained at the highest height.

(E) Lowering the Vehicle Height (FIG. 7) When the vehicle height is to be lowered to a predetermined height, the driver must
The vehicle height setting device 74 is set to that height. At this time, the vehicle height control device 73 excites the on-off valve solenoid 50 to pull the first plunger 51 in the direction of arrow A, and at the same time, excites the relief valve solenoid 70 and pulls the second plunger 71 in the direction B. When the first plunger 51 is pulled in the direction A, the hydraulic oil 10 in the spring receiving pressure chamber 32 is subjected to the hydraulic oil introduction passage 33, the branch hole 57, the branch groove 56, and the branch flow as shown by the solid arrow in FIG. To the road 52B, the device housing 1
6 to the flow path 65. At this time, the operation sleeve 48 is pulled by the first plunger 51 to open / close the valve spring 4.
7, the lower opening / closing valve 42 is lowered to the position of the operation sleeve 48, and the lower opening / closing valve 42 is opened. In this state, the hydraulic oil 10 that has reached the flow path 65 is supplied to the upper open / close valve flow path 46 by the upper open / close valve 41.
It is guided into the inside and flows into the reserve chamber 13 from the contraction side communication passage 17C.

At this time, since the second plunger 71 is pulled in the direction of arrow B and the relief valve 44 is opened, during the compression of the hydraulic shock absorber 5 in the cushion unit 3, the lower piston pressure chamber 12B The hydraulic oil flows in the relief valve channel 59A, the relief hole 60, and the relief channel 59B sequentially from the contraction side communication passages 17A and 17B, and is guided to the reserve chamber 13. In the course of extension of the hydraulic shock absorber 5, the hydraulic oil 10 in the reserve chamber 13 is supplied to the extension side communication passage 18.
Through the lower piston pressure chamber 12B.

(F) Vehicle Height Lowering Stop State (FIG. 5) When the vehicle height matches the height set by the vehicle height setting device 74, the vehicle height control device 73 sets the relief valve solenoid 7
The on / off valve solenoid 50 is de-energized while keeping the relief valve 44 in the open state while maintaining 0 in the excited state. Then, the operating sleeve 48 is raised by the urging force of the on-off valve spring 47, and the lower on-off valve 42 is closed together with the upper on-off valve 41, so that the spring receiving pressure chamber 32 and the reserve chamber 13
The flow of the hydraulic oil 10 to the vehicle is stopped, and the lowering of the vehicle height is stopped.

At this time, since the relief valve 44 is open, the hydraulic oil 10 in the lower piston pressure chamber 12B flows from the compression side communication passages 17A and 17B in the compressed state of the hydraulic shock absorber 5 in the cushion unit 3. It is guided to the reserve chamber 13 via the relief channel 59A, the relief hole 60 and the relief channel 59B. During the extension process of the hydraulic shock absorber 5, the hydraulic oil 10 in the reserve chamber 13 is guided to the lower piston pressure chamber 12B via the extension communication path 18. Thus, the vehicle height is maintained.

(G) Vehicle Height Lowering State (FIG. 3) When the vehicle height is lowered to the lowest height, the driver sets the vehicle height setting device 74 to the lowest height. When the cylinder spring receiver 22 is lowered to the lowest height when the vehicle height is lowered as described in (F), the pressure in the spring receiving pressure chamber 32 is sufficiently reduced. , The upper open / close valve 41 is opened, and the lower open / close valve 4 is opened.
2 is closed. Therefore, at this time, the vehicle height control device 73
With the relief valve solenoid 70 de-energized, the relief valve 44 is closed. In this state, the hydraulic oil 10 flows as shown in FIG.

(H) Effect According to the above embodiment, when the on / off valve solenoid 50 is de-energized to release the pulling operation of the first plunger 51 and the upper and lower opening / closing valves 41 and 42 are closed, the check is stopped. The valve 43 is opened, and the contraction side communication passages 17A and 17B, the branch passage 52A
, 52B, the branch groove 56, the branch hole 57, and the hydraulic oil introduction path 33, and the lower piston pressure chamber 12B and the spring receiving pressure chamber 32 are in communication. For this reason, the hydraulic oil 10 in the lower piston pressure chamber 12B is transferred to the spring receiving pressure chamber 3 by the expansion and contraction movement of the hydraulic shock absorber 5 in the cushion unit 3.
2 and the cylinder spring receiver 22 is raised. As a result, the spring reaction force of the suspension spring 4 increases, and the vehicle can be raised. If the first plunger 51 is pulled by energizing the on-off valve solenoid 50, the lower on-off valve 4
2 is opened, and the spring receiving pressure chamber is opened via the hydraulic oil introduction path 33, the branch hole 57, the branch groove 56, the branch flow path 52B, the flow path 65, the upper open / close valve flow path 46, and the contraction side communication path 17C. 32 and the reserve chamber 13 are in communication. For this reason, the hydraulic oil in the spring receiving pressure chamber 32 is returned to the reserve chamber 13, the cylinder spring receiver 22 is lowered, the spring reaction force of the suspension spring 4 is reduced, and the vehicle can be lowered.

Since the vehicle height is adjusted 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.

The vehicle height can be adjusted by changing the vehicle height setting value of a vehicle height setting device 74 installed in a driver's seat or a bed or the like, so that the vehicle height control device 73 operates the on-off valve solenoid 50 and the relief valve solenoid 70. This operation is performed by energizing or de-energizing the upper and lower valves 41, 42 and the relief valve 44 to open and close. Therefore, the vehicle height can be adjusted only when necessary, and the vehicle height can be set at an arbitrary position.

The vehicle height control device 73 compares the vehicle height setting value set by the vehicle height setting device 74 with the sensor output from the vehicle height sensor 75, and compares the upper opening / closing valve 41 and the lower opening / closing valve. Since the opening and closing operations of the relief valve 42 and the relief valve 44 are performed, the vehicle height can be automatically set to a desired position.

Further, since the spring receiving pressure chambers 32 of the two cushion units 3 installed on the axle 2 near the rear wheel side of the vehicle are connected by the connecting pipe 72, the vehicle width direction can be adjusted when the vehicle height is adjusted. The height can be adjusted at the same time, and the vehicle height balance in the same direction can always be appropriately maintained.

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 vent 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.

In the above embodiment, as shown in FIG. 9A, the vehicle height sensor 75 is provided with the permanent magnet 76 and the magneto-electric element 77.
Although the description has been given of the case of the magnetoelectric sensor using the sensor, the photoelectric vehicle height sensor 78 (FIGS. 9B and 9C), the electric vehicle height sensor 79, and the switch vehicle height sensor 80 Is also good.

The photoelectric type vehicle height sensor 78 has an indicator plate 81 fixed to the support tube 31 and a photo sensor 82 mounted on the cylinder spring receiver 22. Indicating board 81
In addition, black bands 81A and white bands 81B shown in FIG. 9C are provided alternately. In the vehicle height sensor 78, the photo sensor 82 emits light to the indicating plate 81, and the white band 8 of the indicating plate 81
The vehicle height is detected by receiving the reflected light from 1B.

In the electric vehicle height sensor 79, an electric resistance plate 83 is fixed to the support tube 31, a spring-biased electrode 84 is installed on the cylinder spring receiver 22, and the electric resistance at the time of adjusting the vehicle height is adjusted. The vehicle height is detected by the change.

Further, the switch-type vehicle height sensor 80 is provided with a plurality of switches 85 on the support tube 31, and a contact 86 provided on the cylinder spring receiver 22 comes into contact with each switch 85 to reduce the vehicle height. To detect.

Although the vehicle height sensors 75, 78, 79 and 80 have been described as being installed on the cushion unit 3, they may be installed on the vehicle body.

In the above embodiment, the solenoids 50 and 70 are used as the electric driving means for driving the upper opening / closing valve 41, the lower opening / closing valve 42, and the relief valve 44, but the motor 87 shown in FIG. There may be. In this case, a pinion 88 is attached to a shaft of the motor 87, a rack rod 90 on which a rack 89 is engraved is engaged with the operating sleeve 48 (or the relief valve 44), and the pinion 88 is engaged with the rack 89, Motor 8
8 drives the operating sleeve 48 (or the relief valve 4).
4) is a pull operation performed against the on-off valve spring 47 (or the relief valve spring 62).

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 a design change or the like may be made without departing from the gist of the present invention. Even if present, it is included in the present invention.

[0063]

As described above, according to the cushion unit of the present invention, the vehicle height can be adjusted as required without increasing the cost, and the vehicle height can be adjusted to an arbitrary position.

[Brief description of the drawings]

FIG. 1 (A) is a front view showing a cushion unit according to the present invention applied to a vehicle body, and FIG. 1 (B) is a block diagram showing a control system of the cushion unit in FIG. 1 (A). It is.

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, showing a state where the vehicle is at its lowest position (a state during normal running).

FIG. 4 is a sectional view showing the switching device of FIG. 3 when the vehicle height is increased.

FIG. 5 is a cross-sectional view showing a vehicle height rising stop state and a vehicle lowering stop state of the switching device of FIG. 3;

FIG. 6 is a sectional view showing a state in which the vehicle height of the switching device of FIG. 3 is highest.

FIG. 7 is a sectional view showing the switching device of FIG. 3 when the vehicle height is lowered.

FIG. 8 is a flowchart showing control of the vehicle height control device in FIG. 1 (B).

FIG. 9 is a sectional view showing a vehicle height sensor.

FIG. 10 is a sectional view showing a modification of the electric driving means.

[Explanation of symbols]

 Reference Signs List 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 path 18 Extension side communication path Reference Signs List 21 Lot spring receiver 22 Cylinder spring receiver 32 Spring receiving pressure chamber 33 Hydraulic oil introduction path 40 Switching device 41 Upper open / close valve 42 Lower open / close valve 43 Check valve 44 Relief valve 45 Open / close valve valve seat 48 Operating sleeve 50 Open / close valve solenoid 51 First 1 plunger 52A, 52B branch passage 53 check valve seat 56 branch groove 57 branch hole 59A, 59B relief passage 60 relief hole 70 relief valve solenoid 71 second plunger 73 vehicle height control device 74 vehicle height setting device 75 vehicle height Sensor 76 Permanent magnet 77 Magneto-electric element a Set height signal b Sensor output signal c Signal for on-off valve solenoid d Signal for relief valve solenoid

Claims (3)

(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 provided on a piston rod extending from the piston and a cylinder spring receiver provided on the outer tube; An on-off valve that can be opened and closed by an electric drive means 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 receiver and the outer tube, and is closed via the check valve when the on-off valve is closed. The piston 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 relief valve that can be opened and closed by an external electric drive means is installed between the piston pressure chamber and the reserve chamber, and when the relief valve is opened, hydraulic oil in the piston pressure chamber can be led out to the reserve chamber. A cushion unit characterized by being made. 2. A vehicle height sensor is provided in a cushion unit, a vehicle height setting device is installed in a vehicle, and a vehicle height control device is configured to control an on-off valve and a relief valve based on signals from the vehicle height sensor and the vehicle height setting device. The cushion unit according to claim 1, which controls opening and closing operations of the valve. 3. The cushion unit according to claim 1, wherein the on-off valve is electrically opened and closed by an on-off valve solenoid, and the relief valve is electrically opened and closed by a relief valve solenoid.