JP3488530B2 - 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 arranged 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 Conventionally, there is a cushion unit disposed between a vehicle body and an axle of an automobile, in which the vehicle height can be adjusted. Of these, Japanese Patent Application No. 5-339876 and Japanese Patent Application No.
Cushion unit 1 described in the specification of 6-119720
00, as shown in the left half of FIG. 1B, a rod spring bearing 103 is provided at the tip of the piston rod 102 of the hydraulic shock absorber 101, and a cylinder spring bearing 105 is provided at the outer periphery of the cylinder 104. Rod spring receiver 1
03 and the cylinder spring receiver 105 between the suspension spring 106
And the hydraulic oil in the cylinder 104 is supplied into the spring bearing pressure chamber 109 of the cylinder spring bearing 105, the cylinder spring bearing 105 slides in the axial direction of the cylinder 104 and the suspension spring The spring reaction force of 106 is changed so that the vehicle height can be adjusted.

Reference numeral 107 in the drawing is a bump rubber (first stopper member) provided at the tip of the piston rod 102, and 108 is a bump stopper (second stopper member) installed in the cylinder 104. Is. The bump stopper 108 contacts the bump rubber 107 to define the maximum compression length of the suspension spring 106.

[0004]

In the conventional cushion unit 100 as described above, as shown in FIG. 7 (A), the bump stopper 108 causes the bump rubber to be compressed during compression in the vehicle height lowest descent state (normal state). The maximum compression length of the suspension spring 106, which is in contact with 107, is defined as L. Here, the hydraulic oil is supplied to the spring bearing pressure chamber 109 of the cylinder spring bearing 105 to move the cylinder spring bearing 105 to the position shown in FIG.
As shown in the left half of FIG. 7 (B) and FIG. 7 (B), the cylinder 104 is slid upward in the axial direction by a dimension X, and the vehicle height is set to the maximum rise state by the spring reaction force of the suspension spring 106. And

However, since the dimension Y (FIG. 1 (B)) of the bump rubber 107 and the bump stopper 108 does not change in this vehicle height maximum rise state, the bump spring 108 of the suspension spring 106 that abuts on the bump rubber 107. The maximum compression length is (L-X). In this way, the suspension spring 106 in the vehicle height highest rise state compresses more by the dimension X at the maximum compression than in the vehicle height lowest fall state, so that the maximum stress or stress amplitude (suspension) acting on the suspension spring 106 is increased. Spring 1
The maximum stress and the minimum stress of 06) increase.

In order to cope with this increase in maximum stress, etc.,
By increasing the diameter of the suspension spring 106,
The durability of the suspension spring 1 is secured in this case.
The weight of 06 increases, and the cost increases.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a cushion unit capable of improving the durability of the suspension spring while reducing the weight and cost thereof. .

[0008]

According to a first aspect of the present invention, a piston is slidably disposed in a cylinder, hydraulic oil is filled therein, and a piston rod connected to the piston is connected to the cylinder. A hydraulic shock absorber that projects and allows the cylinder and the piston rod to be arranged between the vehicle body and the axle, a rod spring receiver fixed to the piston rod tip of the hydraulic shock absorber, and the hydraulic shock absorber. A suspension spring interposed between the cylinder spring receiver and the cylinder spring receiver disposed on the cylinder, and the first stopper member provided on the cylinder spring receiving side of the tip end portion of the piston rod and the cylinder of the cylinder. In the cushion unit in which the maximum compression length of the suspension spring is restricted by contact with the second stopper member arranged on the rod spring receiving side,
The cylinder spring receiver is provided slidably in the axial direction of the cylinder by the supply of the hydraulic oil in the cylinder in the hydraulic shock absorber, and the reaction force of the suspension spring can be varied to adjust the vehicle height. The cylinder spring receiver is integrally connected to the second stopper member via the connecting member, and the cylinder spring receiver and the second stopper member are interlocked with each other in the axial direction of the cylinder in the hydraulic shock absorber. It is configured to be possible.

The invention described in claim 2 is the first aspect of claim 1.
At least one of the stopper member and the second stopper member is provided with a discharge hole that opens toward the other stopper member.

The invention described in claim 3 is the invention according to claim 1 or 2.
The connecting member described in 1 is formed in a tubular shape surrounding the cylinder of the hydraulic shock absorber, and the connecting member has a discharge hole penetrating from the inner surface to the outer surface.

[0011]

According to the invention described in claim 1, the following effects are exhibited. When the vehicle height is adjusted by moving the cylinder spring receiver in the axial direction of the cylinder, the second stopper member arranged on the cylinder moves in the same direction and in the same amount in conjunction with the cylinder spring receiver. From this, when the cylinder spring receiver moves to the rod spring receiving side when the vehicle height rises, the second stopper member also moves to the rod spring receiving side by the same amount, and the dimension between the first stopper member and the second stopper member is the cylinder. The amount of movement of the spring bearing is shortened. As a result, the maximum compression length of the suspension spring defined by the contact of the second stopper member with the first stopper member is the same in both the vehicle height maximum rise state and the vehicle height minimum fall state. ,
The maximum stress acting on the suspension spring and the stress amplitude (amplitude of the maximum stress and the minimum stress) can always be maintained within an appropriate range. Therefore, since it is not necessary to increase the diameter of the suspension spring in order to apply it to the above-mentioned maximum stress, the durability of the suspension spring can be improved without increasing the weight and cost of the suspension spring.

According to the second aspect of the present invention, the following action is obtained. Since at least one of the first stopper member and the second stopper member is formed with a discharge hole that opens to the other stopper member side, at the time of maximum compression of the suspension spring in which the second stopper member abuts the first stopper member, Air, water, etc. compressed between both stopper members can be satisfactorily discharged from the discharge hole.

According to the third aspect of the invention, the following action is brought about. Since the discharge hole that penetrates from the inner surface to the outer surface is formed in the connecting member that connects the cylinder spring receiver and the second stopper member, the integrally connected cylinder spring receiver, the second stopper member and the connecting member, and the hydraulic buffer. The water or oil stored in the space surrounded by the cylinder of the container can be satisfactorily discharged to the outside from the discharge hole.

[0014]

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.
The right half shows the cushion unit of FIG. 1 (A), and the left half is the sectional view of the cushion unit of FIG. 7. FIG. 2 is an enlarged sectional view showing a lower half portion of the cushion unit of FIG. FIG. 3 is a further enlarged view of the switching device of FIG. 2 and shows the vehicle in the lowest position (state during normal running).
FIG. FIG. 4 is a cross-sectional view showing the vehicle height of the switching device of FIG. FIG. 5 is a cross-sectional view of the switching device of FIG. 3 when the vehicle height is lowered. FIG. 6 is an enlarged cross-sectional view of the upper half portion of the cushion unit of FIG. 1A, showing the suspension spring in the most compressed state. FIG. 7 is an enlarged view of the upper half of the conventional cushion unit, and is a cross-sectional view of the suspension spring in the most compressed state.

As shown in FIG. 1, a cushion unit 3 is arranged 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 shock from the road surface, and the hydraulic shock absorber 5 damps the expansion and contraction movement of the cushion unit 3 accompanying the shock absorption of the suspension spring 4. The cushion unit 3 is one of the four wheels 6 of the automobile.
One axle is installed on each axle 2 near the rear wheels, and a normal cushion unit is installed on each axle 2 near the front wheels.

As shown in FIG. 2, the hydraulic shock absorber 5 includes a cylinder 7 having an inner tube 8 and an outer tube 9. The inner tube 8 is filled with hydraulic oil 10 and the piston 11 slides. Arranged freely. 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 reserve chamber 13 is formed between the inner tube 8 and the outer tube 9, and hydraulic oil 10 is provided below in the drawing.
The gas (air) 14 is filled in the upper part.

The bottom piece 1 is attached to the lower end of the inner tube 8.
5 is fixed, and the switching device 4 is further attached to the bottom piece 15.
The device housing 16 of 0 (described later) is fitted. The bottom piece 15 and the device housing 16 are formed with compression side communication passages 17A, 17B and 17C, and the bottom piece 15 is formed with an extension side communication passage 18 so that the lower piston pressure chamber 12B and the reserve chamber 13 can communicate with each other. It is provided.

On the other hand, the piston 11 is the piston rod 19
The piston rod 19 extends from the cylinder 7, the rod end 20 (FIG. 1) is fixed to the end, and the rod spring receiver 21 is connected to the rod end 20. A cylinder spring receiver 22 is arranged on the outer circumference 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 mounted 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 further supported on the vehicle body 1, The cushion unit 3 absorbs the impact from the road surface by the suspension spring 4.
Further, the cushion unit 3 damps the expansion / contraction movement of the cushion unit 3 due to the shock absorption of the suspension spring 4 mainly by the compression side disc 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.
Further, the contraction side communication passage 17B is arranged so as to be closed, and the extension side check valve 25 is arranged so that the extension side communication passage 18 can be closed. Further, the first valve 26 is installed on the piston 11 together with the second valve 27. A plurality of contraction-side channels 28 and expansion-side channels 29 are alternately bored in the piston 11 in the circumferential direction. The first valve 26 can close the expansion side flow path 29, and the second valve 27 can close the contraction side flow path 28.

In the compression process of the cushion unit 3 during normal traveling (the vehicle is at the lowest position), the hydraulic oil 10 in the lower piston pressure chamber 12B passes through the compression side flow passage 28 and the second valve 27, and the upper piston pressure chamber 12A. As you reach inside,
As shown by the solid line arrow in FIG. 3, the upper opening / closing valve 41, which will be described later, is opened to open the extension side communication passage 17A and the compression side disc valve 2.
4, the hydraulic fluid 10 in the lower piston pressure chamber 12B reaches the reserve chamber 13 through the compression-side communication passages 17B and 17C sequentially. The fluid resistance of the compression side disc valve 24 mainly generates a damping force in the compression process.

Further, in the process of extension of the cushion unit 3 during normal traveling (vehicle height most lowered state), the hydraulic oil 10 in the reserve chamber 13 is, as shown by the broken line arrow in FIG.
The hydraulic oil 10 in the upper piston pressure chamber 12A shown in FIG. 2 passes through the extension side flow passage 29 and the first valve 26 while passing through the extension side communication passage 18 and the extension side check valve 25 into the lower piston pressure chamber 12B. The inside of the lower piston pressure chamber 12B is reached. The fluid resistance of the first valve 26 mainly generates a damping force in the expansion process.

Now, as shown in FIG. 2, the partition wall member 30 is provided on the inner surface of the cylinder spring receiver 22.
It is 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 a support tube 31. The partition wall member 30 forms a spring bearing pressure chamber 32 between the cylinder spring bearing 22 and the outer tube 9. This spring receiving pressure chamber 32
Is provided so as to be able to communicate with the lower piston pressure chamber 12B via a hydraulic oil introduction path 33 between the outer tube 9 and the support tube 31, a check valve 43 described later, and the like. An oil seal 3 is provided between the partition wall member 30 and the cylinder spring receiver 22.
4, the spring receiving pressure chamber 32 has a closed structure.

A dust seal 37 is supported by a seal member 38 at the lower end of the cylinder spring receiver 22. Further, reference numeral 39 indicates a bush.

As shown in FIGS. 2 and 3, a switching device 40 is installed at the lower end of the outer tube of the cylinder 7. The switching device 40 includes an upper opening / closing valve 41 on the device housing 16.
And the lower opening / closing valve 42 are installed adjacent to each other in the vertical direction, and the check valve 43 and the relief valve 44 are further installed.

The upper open / close valve 41 opens / closes an open / close valve seat 45 disposed between the compression side communication passages 17B and 17C in the apparatus housing 16. In addition, the lower opening / closing valve 42
Is for opening and closing the upper opening / closing valve flow path 46 formed in the upper opening / closing valve 41. The upper opening / closing valve 41 and the lower opening / closing valve 42 include an operating sleeve 48 urged by an opening / closing valve spring 47.
The upper open / close valve 41 abuts (closes) the open / close valve seat 45 to close between the compression side communication passages 17B and 17C, and the lower open / close valve 42 closes the upper open / close valve flow path 46 (close valve). ) Acts like.

The operating sleeve 48 is slidably arranged in a sleeve housing 49, and the sleeve housing 4
9 is integrated with the on-off valve solenoid 50. An on-off valve spring 47 is interposed between the operating sleeve 48 and the sleeve housing 49. Here, a cylinder bracket 51A is fixed to the lower end portion of the outer tube 9, and a bracket lid 51B attached to the cylinder bracket 51A.
Thus, the on-off valve solenoid 50 is supported. The first plunger 51 of the on-off valve solenoid 50 is locked to the operating sleeve 48.

In the non-excited 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. However, when the opening / closing valve solenoid 50 is in the excited state, the first plunger 51 moves to the position shown in FIG.
Is pulled 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 on-off valve 41 is separated from the on-off valve seat 45 (open) by the action of the pressure of the hydraulic oil 10 in B, and the compression side communication passages 17B and 17
C becomes a communication state. At this time, the lower opening / closing valve 42 is
When the pressure of the hydraulic oil 10 in the lower piston pressure chamber 12B is higher than the pressure in the spring bearing pressure chamber 32, the upper open / close valve flow path 4
6 is closed (valve closed), and when the pressure of the hydraulic oil 10 in the spring receiving pressure chamber 32 is higher than the pressure of the lower piston pressure chamber 12B, the upper opening / closing valve flow path 46 is opened as shown in FIG. State (open valve). Reference numeral 67 indicates an electric wire for supplying power to the on-off valve solenoid 50.

Further, in the apparatus housing 16 shown in FIG. 3, branch flow passages 52A and 52B are branched from the compression side communication passage 17B, and a check valve seat 53 is installed between the branch flow passages 52A and 52B. . The branch flow passage 52B is further communicated with a branch groove 56 and a branch hole 57 formed in the outer tube 9, and the branch hole 57 is communicated with the hydraulic oil introducing passage 33. The check valve 43 opens and closes the check valve seat 53, and therefore is installed in parallel with the upper opening valve 41 and the lower opening valve 42. The check valve 43 is slidably fitted to a check valve sleeve 54 screwed to the device housing 16. The check valve 43 has a cylindrical shape with a lid, and the check valve 4
A check valve spring 55 is interposed between the inside 43 </ b> A of 3 and the check valve sleeve 54. Further, the inside 43 of the check valve 43
A is communicated with the branch flow passage 52B by the passage 58.

Therefore, the check valve 43 is operated 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. Is pressed to close 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 passage 52A. When the hydraulic oil 10 becomes larger than the biasing 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 passage 59A is communicated with the compression-side communication passage 17B, and the relief flow passage 5
9B is communicated with the reserve chamber 13. A relief hole 60 is opened between the relief flow channels 59A and 59B. The relief valve 44 can open and close the relief hole 60.

The relief valve 44 includes the relief valve plate 6
It is slidably installed in the apparatus housing 16 via a relief valve spring 62 between the first and second terminals. The relief valve plate 61 is integrated with the relief valve solenoid 70,
This relief valve solenoid 70 is used for the cylinder bracket 5
Locked at 1A. The relief valve 44 has a flange portion 63.
Further, the device housing 16 is provided with a relief valve operating hole 64 at a position corresponding to the flange portion 63. The relief valve actuation hole 64 opens into the branch groove 56 of the outer tube 9. Further, the relief valve solenoid 70 includes a second plunger 71, and the second plunger 71 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 working oil 10 in the spring pressure chamber 32 exceeds a predetermined value, this pressure is introduced into the working oil introducing passage 33, the branch hole 57, and the branch groove 56. Also, it acts on the flange portion 63 via the relief valve actuation hole 64, and the relief valve 44 slides against the relief valve spring 62 to open. Further, when the relief valve solenoid 70 is excited, the second plunger 7
1 is pulled in the direction of arrow B in FIG. 5, whereby the relief valve 44 opens. Reference numeral 66 indicates an electric wire for supplying power to the relief valve solenoid 70.

When the hydraulic oil 10 is pumped into the spring pressure chamber 32 shown in FIG. 2 by the switching device 40 configured as described above, the suspension spring 4 is compressed and the vehicle height is increased. The vehicle height is raised and the vehicle height is lowered by discharging the hydraulic oil 10 from the spring pressure chamber 32.

That is, when it is desired to raise the vehicle height to a predetermined height, as shown in FIG. 4, the opening / closing valve solenoid 5 is maintained while the relief valve solenoid 70 is kept in the non-excited state.
0 is deenergized. Then, the on-off valve spring 47
The operating sleeve 48 presses the lower opening / closing valve 42 and the upper opening / closing valve 41 upward in FIG. 4 by the urging force of, and the upper opening / closing valve 41 abuts the opening / closing valve seat 45 to be in the closed state. At this time, the lower opening / closing valve 42 also continuously maintains the closed state. Depending on the closed state of the upper opening / closing valve 41, the compression side communication passages 17B and 17C
Communication between them is cut off.

Therefore, during 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 causes the compression side disc valve 24 to flex and deform as shown by the solid line arrow in FIG. While generating a damping force, the compression side communication passage 17B reaches the inside of the branch flow passage 52A. The check valve 43 opens when the pressure of the hydraulic oil 10 in the branch flow passage 52A becomes larger than the biasing force of the check valve spring 55 and the pressure of the hydraulic oil 10 in the spring receiving pressure chamber 32. To do. As a result, the hydraulic oil in the lower piston pressure chamber 12B that has reached the branch flow passage 52A is introduced from the branch flow passage 52B into the hydraulic oil introduction passage 33 through the branch groove 56 and the branch hole 57, and inside the spring receiving pressure chamber 32. Pumped to. Due to the hydraulic oil 10 being fed under pressure into the spring bearing pressure chamber 32, the cylinder spring bearing 22 moves upward in FIG.
Is compressed.

During the expansion process of the hydraulic shock absorber 5 in the cushion unit 3, the hydraulic oil 10 in the spring receiving pressure chamber 32 is
Pressure from the branch flow passage 52B through the passage 58 to the check valve 4
3, the check valve 43 keeps the closed state. Therefore, 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 the broken line arrow in FIG. Therefore, in the expansion process of the hydraulic shock absorber 5, the compression state of the suspension spring 4 in the compression process performed before that is maintained.

By repeating the compression process and the expansion process of the hydraulic shock absorber 5 described above, the amount of the hydraulic oil 10 in the spring receiving pressure chamber 32 supplied from the lower piston pressure chamber 12B gradually increases, and the cylinder spring receiving member 22 2, the suspension spring 4 is gradually compressed as it moves further upward in FIG. 2, the spring reaction force increases, and the vehicle height rises.

When it is desired to lower the vehicle height to a predetermined height, as shown in FIG. 5, the opening / closing valve solenoid 50 is excited to pull the first plunger 51 in the direction of arrow A, and at the same time, the relief valve solenoid 70 is excited. , Second plunger 7
Pull 1 in the B direction. When the first plunger 51 is pulled in the A direction, the hydraulic oil 10 in the spring receiving pressure chamber 32 is transferred to the hydraulic oil introducing passage 33 and the branch hole 5 as shown by the solid line arrow in FIG.
7, the branch groove 56, and the branch flow path 52B, and reaches the flow path 65 of the apparatus housing 16. At this time, the operating sleeve 4
8 is lowered downward in FIG. 5 against the urging force of the on-off valve spring 47 by the pulling operation of the first plunger 51, the lower on-off valve 42 descends to this operating sleeve 48 position, and the lower on-off valve 42 The valve is opened. In this state, the hydraulic oil 10 that has reached the flow path 65 as described above is transferred to the upper opening / closing valve 4
1 is introduced into the upper open / close valve passage 46 and flows into the reserve chamber 13 from the compression side communication passage 17C. In this way, since the hydraulic oil in the spring receiving pressure chamber 32 is returned to the reserve chamber 13,
The cylinder spring receiver 22 descends, the spring reaction force of the suspension spring 4 decreases, and the vehicle descends.

When the vehicle height is lowered, the second plunger 71 is pulled in the direction of the arrow B and the relief valve 44 is opened. Therefore, during the compression process of the hydraulic shock absorber 5 in the cushion unit 3, the lower piston pressure is reduced. The hydraulic oil in the chamber 12B flows from the compression side communication passages 17A and 17B to the relief valve flow passage 5
9A, the relief hole 60, and the relief flow path 59B are sequentially flowed to be guided to the reserve chamber 13. Further, during the expansion process of the hydraulic shock absorber 5, the hydraulic oil 10 in the reserve chamber 13 is guided into the lower piston pressure chamber 12B via the expansion side communication passage 18.

By the way, as shown in the right half of FIG. 1 (B) and FIGS. 6 (A) and 6 (B), the tip of the piston rod 19 of the hydraulic shock absorber 5 has a rod end 20 as described above. The rod spring receiver 21 is fixed via the cylinder spring receiver 22 and the bump rubber 73 as a first stopper member is installed on the cylinder spring receiver 22 side. Further, the outer tube 9 of the cylinder 7 of the hydraulic shock absorber 5 is detachably provided with a bump stopper 74 as a second stopper member on the end surface on the rod spring receiver 21 side. The bump stopper 74 is integrally formed with the cylinder spring receiver 22 and connected by a cylindrical connecting sleeve 75 as a connecting member.

When the hydraulic shock absorber 5 expands and contracts, the bump stopper 74 contacts the bump rubber 73, whereby the maximum compression length of the suspension spring 4 is regulated. Further, the bump stopper 74 is supplied in the same direction as the cylinder spring receiver 22 in the same direction when the vehicle height is adjusted such that the hydraulic oil 10 is supplied to and discharged from the spring receiver pressure chamber 32 and the cylinder spring receiver 22 moves in the axial direction of the cylinder 7. Move by the amount.

The bump stopper 74 slides on the piston rod 19 in a loosely fitted state, and a stopper discharge hole 77 is formed in the bump stopper 74 to communicate the sliding surface 76 with the outside. Therefore, the piston rod 19
The gap t between the outer peripheral surface of the and the sliding surface 76 becomes an opening toward the bump rubber 73 side, and when the suspension spring 4 in which the bump stopper 74 contacts the bump rubber 73 is maximally compressed, it passes through the gap t and the stopper discharge hole 77. , Bump stopper 74
The compressed air and water between the bump rubber 73 and the bump rubber 73 can be discharged to the outside.

A sleeve discharge hole 78 is formed in the connecting sleeve 75 on the cylinder spring receiver 22 side. The sleeve discharge hole 78 is formed so as to penetrate from the inner surface to the outer surface of the connecting sleeve 75, and is integrally formed with the bump stopper 74, the connecting sleeve 75, and the cylinder spring receiver 2.
Water and oil stored in the space 79 between the cylinder 2 and the cylinder 7 of the hydraulic shock absorber 5 can be discharged to the outside.

According to the above embodiment, the cylinder spring receiver 2
When 2 is moved in the axial direction of the cylinder 7 in the hydraulic shock absorber 5 to adjust the vehicle height, the bump stopper 74 interlocks with the cylinder spring receiver 22 and moves in the same direction by the same amount. From this, as shown in the right half of FIG.
When the cylinder spring receiver 22 moves upward in the drawing by the dimension X when the vehicle height rises, the bump stopper 74 also moves upward by the same amount X, and the bump rubber 73 and the bump stopper 74 are moved.
The distance between and becomes shorter by the movement amount X of the cylinder spring receiver 22 (Y-X). As a result, the maximum compression length of the suspension spring 4 regulated by the bump stopper 74 contacting the bump rubber 73 is as shown in FIGS. 6A and 6B. Even in the most lowered state, the same amount L is obtained, and therefore, at this time, the maximum stress and the stress amplitude (amplitude between the maximum stress and the minimum stress) acting on the suspension spring 4 can always be maintained within an appropriate range. Therefore, since it is not necessary to increase the diameter of the suspension spring 4 in order to apply it to the maximum stress and the like, the durability of the suspension spring 4 can be improved without increasing the weight or cost of the suspension spring 4.

Further, since the bump stopper 74 is formed with the discharge hole 77 opening to the bump rubber 73 side through the gap t, the bump stopper 74 can be replaced by the bump rubber 73.
At the time of maximum compression of the suspension spring 4 that abuts on the air, water or the like compressed between the bump rubber 73 and the bump stopper 74 can be satisfactorily discharged from the gap t and the discharge hole 77, and the maximum compression length of the suspension spring 4 can be reduced. Can be secured.

Further, since the sleeve discharge hole 78 penetrating from the inner surface to the outer surface is formed in the connecting sleeve 75 which connects the cylinder spring receiver 22 and the bump stopper 74, the cylinder spring receiver 22 and the bump stopper which are integrally connected are formed. Water, oil, and the like stored in the space 79 surrounded by 74 and the connecting sleeve 75 and the cylinder 7 of the hydraulic shock absorber 5 can be satisfactorily discharged from the sleeve discharge hole 78 to the outside.

Although the gap t and the stopper discharge hole 77 are formed in the bump stopper 74 according to the above embodiment, the gap t and the stopper discharge hole 77 may be provided in the bump rubber 73. good.

[0049]

As described above, according to the cushion unit of the present invention, the weight and cost of the suspension spring can be reduced and the durability thereof can be improved.

[Brief description of 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) shows a right half of the cushion unit of FIG. 1 (A) and a left side thereof. FIG. 8 is a sectional view showing half of the cushion unit of FIG. 7.

FIG. 2 is an enlarged cross-sectional view showing a lower half portion of the cushion unit in FIG. 1 (A).

FIG. 3 is a cross-sectional view showing a further enlarged state of the switching device of FIG. 2 and showing a vehicle lowermost state (state during normal traveling).

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

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

6 is an enlarged cross-sectional view of the upper half of the cushion unit of FIG. 1A, showing the suspension spring in the most compressed state.

FIG. 7 is an enlarged view of the upper half of a conventional cushion unit, and is a cross-sectional view of the suspension spring in the most compressed state.

[Explanation of symbols]

1 car body 2 axles 3 cushion unit 4 suspension springs 5 hydraulic shock absorber 7 cylinders 10 hydraulic oil 11 pistons 19 piston rod 21 Rod spring receiver 22 Cylinder spring support 73 bump rubber 74 bump stopper 77 Stopper discharge hole 78 Sleeve discharge hole Maximum compression length of L suspension spring t gap

Claims (3)

(57) [Claims] 1. A piston is slidably disposed in a cylinder and is filled with hydraulic oil, a piston rod connected to the piston is projected from the cylinder, and the cylinder and the piston rod are connected to a vehicle body and an axle. And a rod spring receiver fixed to the piston rod tip of the hydraulic shock absorber and a cylinder spring receiver arranged in the cylinder of the hydraulic shock absorber. A first stopper member having a suspension spring interposed therebetween and provided on the cylinder spring receiving side of the piston rod tip portion, and a second stopper provided on the rod spring receiving side of the cylinder. In a cushion unit in which the maximum compression length of the suspension spring is regulated by abutting against a member, the cylinder spring receiver is provided with When the hydraulic oil is supplied to the cylinder, it is slidably provided in the axial direction of the cylinder to change the reaction force of the suspension spring to adjust the vehicle height. Cushion unit characterized in that the two stopper members and the second stopper member are integrally connected via a connecting member, and the cylinder spring receiver and the second stopper member are interlockable in the axial direction of the cylinder in the hydraulic shock absorber. . 2. The cushion unit according to claim 1, wherein at least one of the first stopper member and the second stopper member is formed with a discharge hole that opens toward the other stopper member. 3. The cushion unit according to claim 1, wherein the connecting member is formed in a tubular shape surrounding a cylinder of the hydraulic shock absorber, and the connecting member has a discharge hole penetrating from an inner surface to an outer surface. .