JP2000337424A - Damper with car height regulating mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify structure and to improve assemblability, in a damper with a car height regulating mechanism having a damper cylinder to which a reservoir chamber and a low pressure tank chamber are annexed. SOLUTION: In a damper 10 with a car height regulating mechanism, a communication hole 27 communicating with the low pressure chamber 26 of a reservoir pipe 102 is opened to the outer periphery of the reservoir pipe 102, and a valve element 29 is situated on the outer periphery of the reservoir pipe 102. During insertion of the reservoir pipe 102 into the outer tube 101 for assembly, an operation part 101A with which an outer tube 101 is provided sets a valve element 29 from a closing position for the communication hole 27 to its opening position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a damper with a vehicle height adjusting mechanism.

[0002]

2. Description of the Related Art Conventionally, as a damper with a vehicle height adjusting mechanism,
As described in JP-A-9-42362, a double pipe structure is formed by inserting a damper cylinder into an outer tube, a piston rod is inserted into the damper cylinder, and two oils are introduced into the cylinder by a piston attached to the piston rod. Define a room,
In some cases, the oil in the low-pressure tank chamber is supplied into the damper cylinder, and as a result, the oil pressure in the damper cylinder is increased to increase the vehicle height by increasing the hydraulic reaction force acting on the piston rod end face.

In the prior art, a diaphragm retainer is provided at an intermediate portion in the height direction of a gap between an outer tube and a damper cylinder, an upper space of the diaphragm retainer is a low-pressure tank chamber, and a lower space is a piston rod volume in the damper cylinder. A reservoir chamber for compensation is provided, and this reservoir chamber is partitioned by a diaphragm into an oil chamber and a gas chamber.

[0004]

However, in the prior art, the low-pressure tank chamber and the reservoir chamber are combined into a single gap between the outer tube and the damper cylinder.
The structure is extremely complicated, and the assemblability is very poor.

An object of the present invention is to simplify the structure of a damper with a vehicle height adjusting mechanism in which a reservoir chamber and a low-pressure tank chamber are attached to a damper cylinder and improve the assembling property.

[0006]

According to a first aspect of the present invention, there is provided a triple tube structure in which a reservoir tube is inserted into an outer tube, a damper cylinder is inserted into the reservoir tube, and a piston rod is inserted into the damper cylinder. , Two oil chambers are defined in the damper cylinder by a piston attached to the piston rod, and a reservoir chamber communicating with one of the oil chambers of the damper cylinder inside the reservoir pipe, and a low-pressure chamber separated from the oil chambers. A vehicle height adjustment mechanism that defines a chamber, defines a low-pressure tank chamber that communicates with the low-pressure chamber of the reservoir pipe inside the outer tube, and has a pump device that supplies oil in the low-pressure tank chamber into the damper cylinder. A damper for opening and closing a communication hole communicating with the low-pressure chamber of the reservoir pipe on an outer periphery of the reservoir pipe, and providing a valve body for opening and closing the communication hole on the outer periphery of the reservoir pipe; The assembly or the like for inserting the reservoir tube over blanking, in which the operation unit to which the outer tube is provided is so as to be set in the open position the valve body from the closed position for the communicating hole.

According to a second aspect of the present invention, in the first aspect of the present invention, the pump device is further fixed to a partition member forming a low-pressure chamber inside the reservoir pipe and rises in the damper cylinder. Slidably fitted to the pump tube inserted into the hollow part of the piston rod,
A pump rod that forms a pump chamber in the pump tube, a suction path provided on the pump rod and communicating the low-pressure tank chamber with the pump chamber through a low-pressure chamber of the reservoir pipe, and a low-pressure tank provided on the suction path. A check valve for suction that allows only the flow of oil from the chamber to the pump chamber, and a discharge path provided on the pump rod and communicating the pump chamber with the oil chamber of the cylinder;
A discharge check valve that is provided in the discharge path and allows only the flow of oil from the pump chamber to the oil chamber of the damper cylinder, and is provided between the pump rod and the pump tube, and according to their relative positions, A standard passage for connecting the pump chamber to an oil chamber in the cylinder when the piston rod extends to a predetermined standard vehicle height position, and a damper cylinder for the suction passage when the piston rod further extends to a predetermined standard vehicle height position. And a return passage for conducting the internal oil chamber.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the reservoir chamber has a free piston, and the free piston divides the reservoir chamber into an oil chamber and a gas chamber. The oil in the oil chamber is pressurized by the gas pressure in the gas chamber.

According to a fourth aspect of the present invention, in the second or third aspect of the present invention, the suction port of the pump rod is set closer to the bottom of the low-pressure chamber.

The present invention according to claim 5 provides the present invention according to claims 1-4.
In the present invention described in any one of the above, further, a communication hole through which the reservoir pipe communicates with the reservoir chamber is also opened on the outer periphery of the reservoir pipe, and the valve body can also open and close the communication hole.

[0011]

According to the first and second aspects of the present invention, the following effects are obtained. The damper cylinder is inserted into the reservoir pipe, the piston rod is inserted into the damper cylinder, and the oil chamber in the damper cylinder, the low-pressure chamber in the reservoir pipe, and the damper sub-assembly in which the reservoir chamber is filled with oil can be assembled in advance. In this damper subassembly, a valve provided on the outer circumference of the reservoir pipe closes a communication hole opened on the outer circumference of the reservoir pipe.

When the reservoir tube constituting the above-described damper sub-assembly is inserted into the outer tube, the operating portion of the outer tube opens the valve body on the outer periphery of the reservoir tube from the closed position, and the low-pressure tank chamber of the outer tube and the reservoir are opened. The low pressure chamber of the pipe communicates with the low pressure chamber, and the assembly of the damper can be completed.

As described above, the sub-assembly is pre-assembled, and the reservoir tube of this sub-assembly is simply inserted into the outer tube to function as a damper, so that the structure is simple and the assemblability can be improved.

According to the third aspect of the present invention, the following operations are provided. A free piston was provided in the reservoir chamber. The free piston pressurizes the oil in the damper cylinder by gas pressure, and prevents the oil from blowing up from the oil chamber on the piston side of the damper cylinder to the oil chamber in the reservoir chamber during compression, so that air is mixed into the oil This prevents the occurrence of cavitation that may occur, and also avoids the delay (dribbling) of the generation of damping force during compression following expansion.

According to the present invention, there is provided the following operation. In a state where the communication hole provided in the reservoir pipe is provided immediately below the partition member, the pump rod can be penetrated through the partition member, and the penetrating end (suction port) can be provided near the bottom of the low-pressure chamber.
That is, by setting the suction port of the pump rod near the bottom of the low-pressure chamber, even if the air in the low-pressure tank chamber is mixed into the oil and this air enters the low-pressure chamber, this air will flow into the upper part of the low-pressure chamber. And does not enter the suction port of the pump rod and does not enter the damper cylinder. The air staying in the upper part of the low-pressure chamber returns to the low-pressure tank chamber through a communication hole provided in the reservoir pipe.

[0016] The intrusion of air into the damper cylinder causes a delay in the generation of damping force (slop) and a malfunction in vehicle height adjustment.

The air that has entered the damper cylinder is
The oil is returned to the low-pressure chamber together with the oil returned from the suction passage of the pump rod to the low-pressure chamber by adjusting the vehicle height, and then discharged from the upper part of the low-pressure chamber to the low-pressure tank chamber through a communication hole provided in the reservoir pipe.

According to the present invention, the following effects are obtained. A communication hole communicating with the low pressure chamber and a communication hole communicating with the reservoir chamber are provided in the reservoir pipe, and these communication holes can be opened and closed by the valve element. Therefore, when the oil chamber in the damper cylinder, the low-pressure chamber in the reservoir pipe, and the reservoir chamber are filled with oil during the assembly of the above-described damper subassembly, these communication holes can be opened to release air. After the filling of oil and the bleeding are completed, these communication holes are closed by the valve body.

[0019]

FIG. 1 is a sectional view showing a damper, and FIG.
3 is an enlarged view of the lower part of the damper, FIG. 3 is an enlarged view of the upper part of the damper, and FIG. 4 is a sectional view showing a sub-assembly of the damper.

As shown in FIGS. 1 to 3, a damper 10 with a vehicle height adjusting mechanism includes a reservoir pipe 10
2 into the reservoir tube 102 and the damper cylinder 103
Is a triple tube structure. And the damper 10
A damper sub-assembly 104 (FIG. 4) in which a damper cylinder 103 and the like are assembled to the reservoir tube 102 is prepared, and the damper sub-assembly 104 is inserted into the outer tube 101 to be assembled.

In the damper 10, the bottom of the cylindrical outer tube 101 with a bottom is connected to the wheel side, and the mounting bracket 12 at the upper end of the piston rod 11 inserted into the damper cylinder 103 is connected to the vehicle body. A suspension system for a vehicle is configured.

Here, a step-shaped operation portion 101A, which will be described later, is provided on the inner peripheral portion near the lower end of the outer tube 101.
A cap 101 is provided at the upper end opening of the outer tube 101.
B is sealed. The reservoir tube 102 has a cylindrical shape with a bottom, and a stopper ring 10
A valve body 29 described later, which can be locked to 2A, is mounted, a seal case 102B is sealed at the upper end opening, and is inserted into the outer tube 101 in this state. Damper cylinder 10
3 is inserted into the reservoir tube 102 in a state of being supported by a support tube 103A inserted into the inner diameter portion near the lower end of the reservoir tube 102 and a later-described partition member 25 supported by the support tube 103A, A rod guide 103B is sealed in the upper end opening.

The cap 10 of the outer tube 101
1B is a dust seal 1 for the piston rod 11
4. A resin collar 15 is provided, which is screwed to the outer tube 101 via an O-ring 16 in a liquid-tight manner.
01, the reservoir tube 102 inserted through the O-ring 16A is pressed and held. The seal case 102B of the reservoir tube 102 includes an oil seal 17 for the piston rod 11, and is connected to the reservoir tube 102 via an O-ring 18.
And presses and holds the damper cylinder 103 inserted into the reservoir tube 102. Damper cylinder 1
03 includes an O-ring 19 and a bush 20 for the piston rod 11;
1 and is press-fitted into the damper cylinder 101 in a liquid-tight manner, and is pressed and held by the seal case 102B of the reservoir tube 102.

That is, the damper 10 is
The gap between 1 and the reservoir pipe 102 is a low-pressure tank chamber 23,
Here, a specified amount of oil and a low-pressure gas are sealed. The cap 101B of the outer tube 101 is provided with a low-pressure gas sealing plug 24 and a sealing passage 24A.

In the damper 10, a partition member 25 supported by the support tube 103A is inserted into the inner diameter of the lower end of the reservoir tube 102 in a liquid-tight manner by an O-ring 25A. And The reservoir tube 102 has a communication hole 27 communicating with the low-pressure chamber 26.
Can be opened to the outer periphery just below the partition member 25, and a sliding valve body 29 that opens and closes the communication hole 27 with respect to the low-pressure tank chamber 23 can be vertically slid toward the outer peripheral enlarged diameter portion near the lower end thereof. Is provided. The structure of the valve body 29 and the opening / closing mechanism will be described later.

The damper 10 is provided with a gap between the reservoir pipe 102 and the damper cylinder 103,
A reservoir chamber 30 is provided for compensating the oil inside. At this time, the free piston 31 is inserted into the reservoir chamber 30. The free piston 31 is provided with an O-ring 31A that slides on each of the reservoir tube 102 and the damper cylinder 103,
31B, the reservoir chamber 30 is composed of an oil chamber 30A and a gas chamber 3
0B, and the oil in the oil chamber 30A can be pressurized by the high-pressure gas in the gas chamber 30B. A sealing plug 102 for high-pressure gas is provided through the seal case 102B of the reservoir tube 102, and a sealing passage 32A is provided in a rod guide 103B of the damper cylinder 103.

The lower end of the damper cylinder 103 which partitions the reservoir chamber 30 is inserted into the above-mentioned ring-shaped projection of the partition member 25, and the oil chamber 30 A of the reservoir chamber 30 is connected to the communication path 33 provided in the partition member 25. And a damper cylinder 1 through a communication path 34 provided at the lower end of the damper cylinder 103.
No. 03 communicates with a lower oil chamber 42B described later.
That is, when the piston rod 11 contracts, the oil corresponding to the volume of the piston rod 11 entering the damper cylinder 103 is pushed out from the lower oil chamber 42B to the reservoir chamber 30 via the communication paths 33 and 34. When the piston rod 11 is extended, oil corresponding to the retreat volume of the piston rod 11 retreating from the damper cylinder 103 is supplied from the reservoir chamber 30 to the lower oil chamber 42B via the communication paths 33 and 34.

The partition member 25 is provided with a lower oil chamber 42B and a reservoir chamber 30 for the damper cylinder 103.
, And a relief valve 36 is provided in the relief passage 35. The relief valve 36 connects a pump rod 61, which will be described later, to the partition member 25.
Nut 37 for fixing the valve stopper 3
8 is provided as a backup. Relief valve 36
Is composed of a leaf spring-shaped valve element, and when the pressure difference between the lower oil chamber 42B and the reservoir chamber 30 of the damper cylinder 103 with respect to the pressure of the low pressure chamber 26 (low pressure tank chamber 23) exceeds a predetermined value. It is elastically deformed and opened to prevent the internal pressure of the damper cylinder 103 from excessively rising.

In the damper cylinder 103, a piston 41 is provided at an end of the piston rod 11, and the piston 41 is slidably fitted into the cylinder 103, and the inside of the cylinder 103 is divided into an upper oil chamber 42A and a lower oil chamber 42B. Partition into The piston 41 has a contraction-side flow path 43 and an extension-side flow path 44 that connect the upper oil chamber 42A and the lower oil chamber 42B. The compression-side flow path 43 opens when the piston rod 11 contracts to generate a damping force. Disc valve-like compression side valve 43A
The extension-side flow path 44 is provided with a disc-valve-shaped extension-side valve 44A that opens when the piston rod 11 is extended to generate a damping force. At this time, the piston 41, the contraction side valve 43A and the extension side valve 44A are mounted on the piston bolt 46 together with the valve stoppers 45A and 45B and fixed by the nut 47. The piston bolt 46 is screwed onto the piston rod 11. Wear and assemble.

However, the damper 10 has the pump device 60 for supplying the oil in the low-pressure tank chamber 23 into the cylinder 103. The pump device 60 flows the pump rod 61 fixed to the partition member 25 provided at the lower end of the cylinder 103 and raised in the cylinder 103 into the hollow portion 11A drilled from the lower end of the piston rod 11. The pump tube 63 is slidably fitted in a pump tube 63 inserted through the passage, and a pump chamber 62 is formed in the pump tube 63.

The pump rod 61 is fitted so as to penetrate the partition member 25, and the valve stopper 38 and the relief valve 36 are fastened to the partition member 25 by the nut 37 screwed to the penetrating end side. In this state, it is fixed to the partition member 25 in the axial direction. Further, an O-ring 2 is provided at the inner diameter of the partition member 25 through which the pump rod 61 passes.
5A is loaded, and the pump rod 61 is elastically supported in the diameter direction by the O-ring 25A.

The pump tube 63 is connected to the piston rod 11
The piston rod 46 is inserted into the hollow portion 11A of the piston rod 11 in a state of being fitted to the fitting portion 46A provided on the piston bolt 46 screwed to the above.
A is held by a spring 105 loaded at the back end portion of A through a check valve for discharge 67 described later and a stopper ring 63A provided on the outer periphery of the pump tube 63. At this time, the pump tube 63 is fitted with the basket-shaped spring receiver 67C of the discharge check valve 67, and the spring receiver 67C is fitted into the hollow portion 11A of the piston rod 11, so that the pump tube 63 and the piston rod 11 are consequently connected. It is centered in the hollow part 11A. The pump tube 63 is connected to the lower oil chamber 4 of the damper cylinder 103 through the hollow passage 46B of the piston bolt 46 through the lower end opening where the pump rod 61 is inserted.
Open to 2B. Further, the pump tube 63 has a flow path (discharge path 66) between the pump tube 63 and the hollow portion 11A of the piston rod 11.
Form A).

The suction rod 6 penetrates the entire length of the pump rod 61 and communicates with the low-pressure chamber 26, and thus with the low-pressure tank chamber 23.
4 (suction port 64A), and a suction check valve 65 at the upper end of the suction passage 64. At this time, the pump rod 6
The one suction port 64 </ b> A is set to be close to the bottom of the low-pressure chamber 26. The suction check valve 65 is a valve body 65A that opens and closes the suction passage 64 at the upper end of the pump rod 61.
So that the valve body 65A closes the suction passage 64.
The valve spring 65B presses 5A from the pump chamber 62 side, and allows only the flow of oil from the low pressure chamber 26 to the pump chamber 62. 65C is a cage spring support.

The pump tube 63 is connected to the piston rod 11
A discharge path 66A is formed between the hollow portion 11A and the piston 41, and a discharge path 66B is provided in the piston rod 11 immediately above the piston 41. (Path) is provided with a discharge check valve 67. The discharge check valve 67 includes a valve body 67A that opens and closes a discharge port 62A of the pump chamber 62, and a valve body 67A.
The valve body 67A is closed in the pump chamber 6 so that the discharge port 62A is closed.
The valve spring 67B is pressed from the opposite side of the valve spring 2 and allows only oil flow from the pump chamber 62 to the upper oil chamber 42A of the damper cylinder 103. 67C is a cage spring support.

Here, the pump rod 61 has an outer diameter at the base end side as a large outer diameter section 68 which is in sliding contact with the inner diameter section of the pump tube 63 in a liquid-tight manner, and an outer diameter at the distal end side as a small outer diameter section 69. age,
A fixed length range between the large outer diameter portion 68 and the small outer diameter portion 69 is defined as a tapered standard passage forming portion 70, and an orifice-shaped return passage 69 is provided at one or more positions in the axial direction of the small outer diameter portion 69.
Is provided. That is, the pump device 60 moves the large outer diameter portion 68 of the pump rod 61 up and down in the pump tube 63 in a state where the piston rod 11 is at the low vehicle height position lower than the predetermined standard vehicle height position, thereby performing the pumping operation. Then, the oil chambers 42A and 42B of the cylinder 103 and the reservoir chamber 30 are pressurized. On the other hand, the pump device 60 includes the piston rod 1
1 is extended to a predetermined standard vehicle height position, the standard passage forming portion 70 of the pump rod 61 faces the lower end opening of the pump tube 63 or less, and a pump chamber 62 is provided between the pump rod 61 and the pump tube 63. Is formed so as to communicate with the hollow passage 46B of the piston bolt 46, and the pumping operation is released. Also, the pump device 60
When the piston rod 11 further extends to a predetermined high vehicle height position, the return passage 69 of the pump rod 61 faces the lower end opening of the pump tube 63 or less, and the cylinder 103
The lower oil chamber 42B is connected to the hollow passage 46B of the piston bolt 46.
Through the return passage 69 to the suction passage 64 of the pump rod 61.
To release the pumping operation, and return the pressure oil in the oil chambers 42A and 42B of the cylinder 103 and the reservoir chamber 30 to the low-pressure chamber 26 and eventually to the low-pressure tank chamber 23 to depressurize the cylinder 103 and the reservoir chamber 30. .

However, in the damper 10, the communication hole 27 communicating with the low-pressure chamber 26 is opened in the outer periphery of the reservoir pipe 102, and the reservoir chamber 30 and the lower oil chamber 4 are opened.
A communication hole 28 communicating with 2B is also opened, and these communication holes 27 and 28 are formed by the above-mentioned slide type valve element 29 as follows.
It can be opened and closed as in (1) and (2).

(1) Subassembly stage of the damper subassembly 104 In the subassembly stage of the damper subassembly 104, the valve 29
Is in the closing operation position as shown in FIG.
7, 28 are sealed by O-rings 81A to 81C on the inner periphery thereof.

When the reservoir pipe 102 and the damper cylinder 103 are filled with oil in the sub-assembly stage of the damper sub-assembly 104, the communication holes 27 and 28 are temporarily opened by the valve body 29, and the communication holes 27 and 28 are opened. 28 can be used as an air vent passage. Low pressure chamber 2 of reservoir pipe 102
6 communicates with the communication hole 27 through the notch of the support chamber 103A, the reservoir chamber 30 of the reservoir pipe 102, the lower oil chamber 42B of the damper cylinder 103 communicates with the communication path 33 of the partition member 25,
The communication hole 34 communicates with the communication hole 28.

(2) Step of Assembling Damper Subassembly 104 to Outer Tube 101 In the step of assembling damper subassembly 104 to outer tube 101, reservoir tube 102 is connected to outer tube 101.
During the process of insertion into the outer tube 101, the valve body 29 provided on the outer periphery of the reservoir tube 102
The upper end portion is pushed up by a stepped operation portion 101A on the inner peripheral portion near the lower end, and its upper end portion is set to an open position as shown in FIG. 1 where it abuts against a stopper ring 102A engaged with the reservoir tube 102. In this open position, the valve body 29 connects the communication hole 27 of the reservoir pipe 102 and the low pressure chamber 26 to the low pressure tank chamber 23 through the communication passage 29A.

After the damper sub-assembly 104 is inserted into the outer tube 101, a cap 101B is sealed at the upper end opening of the outer tube 101, and low-pressure gas is sealed from the sealing plug 24 into the low-pressure tank chamber 23, so that the damper 10 Is completed.

In FIG. 1, reference numeral 91 denotes a rebound stopper, 92 denotes a rebound rubber, and 93 denotes a stopper ring.

Hereinafter, the operation of the damper 10 will be described. (A) Damping operation (A-1) Extension stroke When the piston rod 11 is extended, the oil in the upper oil chamber 42A of the cylinder 103 is pressurized, and this pressure oil passes through the extension valve 44A of the piston 41 and the lower oil chamber. 42B, and at this time, an extension-side damping force is generated. Also, the cylinder 103
Oil of the retreat volume of the piston rod 11 retreating from
The oil is supplied from the reservoir chamber 30 to the lower oil chamber 42B via the communication path 33 of the partition member 25 and the communication path 34 of the damper cylinder 103.

(A-2) Contraction stroke When the piston rod 11 contracts, the oil in the lower oil chamber 42B of the cylinder 103 is pressurized, and this pressure oil passes through the compression valve 43A of the piston 41 to the upper oil chamber 42A. Moving.
Further, oil corresponding to the volume of the piston rod 11 that enters the cylinder 103 is pushed out from the lower oil chamber 42B to the reservoir chamber 30 via the communication path 33 of the partition member 25 and the communication path 34 of the cylinder 103.

(B) Vehicle Height Adjustment Operation (B-1) At Standard Vehicle Height At standard vehicle height, the piston rod 11 is at the standard vehicle height position, and the standard passage forming portion 70 of the pump rod 61 is at the lower end of the pump tube 63. Facing below the opening, pump rod 61
A standard passage 71 is formed between the pump chamber 63 and the pump tube 63, and the pump chamber 62 is connected to the lower oil chamber 42B of the cylinder 103, so that the pump device 60 does not perform a pumping operation. Therefore, the vehicle height is not adjusted.

(B-2) Low vehicle height When the load on the vehicle increases and the piston rod 11 comes to a low vehicle height position lower than the standard vehicle height position, the pump rod 6
The large outer diameter portion 68 moves up and down by the pump tube 63 to perform a pumping operation. In this state, when the piston rod 11 expands and contracts due to the vibration of the suspension device during traveling, the pump chamber 62 expands and becomes negative pressure when the piston rod 11 expands, so that the oil in the low-pressure tank chamber 23 fills the low-pressure chamber 26. Through the suction passage 64 of the pump rod 61, the pump rod 62 enters the pump chamber 62 through the check valve 65 for suction. When the piston rod 11 subsequently contracts, the pump chamber 62 contracts and is pressurized, so that the oil in the pump chamber 62 flows from the discharge port 62A of the pump tube 63 through the discharge check valve 67 to the cylinder 103. It is supplied to the upper oil chamber 42A. This allows
Oil chambers 42A, 42B of cylinder 103, reservoir chamber 30
Is pressurized, the reaction force of the piston rod 11 increases, and the vehicle is returned to the standard vehicle height position.

(B-3) High vehicle height When the vehicle is unloaded, the piston rod 11
When the vehicle is at a high vehicle height position higher than the standard vehicle height position due to the rising pressure inside the cylinder 03, the return passage 69 of the pump rod 61 faces below the lower end opening of the pump tube 63 and the cylinder 1
The lower oil chamber 42B of 03A is conducted from the return passage 69 to the suction passage 64 of the pump rod 61, and eventually to the low-pressure chamber 26 and the low-pressure tank chamber 23. Thus, the pressure oil in the oil chambers 42A and 42B of the cylinder 103 and the reservoir chamber 30 is returned to the low-pressure tank chamber 23 to reduce the pressure, thereby returning the vehicle to the standard vehicle height position.

When the piston rod 11 is contracted and the pumping operation is performed, the oil chambers 42A, 42
B, the oil pressure in the reservoir chamber 30 increases. In the present embodiment, the relief valve 36 is provided in the partition member 25. When the pressure in the oil chambers 42A and 42B of the cylinder 103 increases extremely, the relief valve 36 opens. Then, the oil in the cylinder 103 escapes to the low-pressure chamber 26 and eventually to the low-pressure tank chamber 23, and safety is ensured.

Therefore, according to the present embodiment, the following operations are provided. Insert the damper cylinder 103 into the reservoir tube 102,
Insert the piston rod 11 into the damper cylinder 103,
The oil chambers 42A and 42B in the damper cylinder 103, the low-pressure chamber 26 in the reservoir pipe 102, and the damper sub-assembly 104 filled with oil in the reservoir chamber 30 can be assembled in advance. In this damper subassembly 104, the reservoir tube 102
A valve body 29 provided on the outer periphery of the reservoir pipe closes the communication hole 27 opened on the outer periphery of the reservoir tube 102.

When the reservoir tube 102 constituting the above-described damper sub-assembly 104 is inserted into the outer tube 101, the stepped operation portion 101A of the outer tube 101 opens the valve body 29 on the outer periphery of the reservoir tube 102 from the closed position. , Low-pressure tank chamber 23 of outer tube 101
And the low pressure chamber 26 of the reservoir pipe 102 communicate with each other, so that the assembling of the damper 10 can be completed.

As described above, the sub-assembly 104 is assembled in advance, and the reservoir tube 102 of this sub-assembly 104 is
Is simply inserted into the outer tube 101 to form the damper 10, the structure is simple, and the assemblability can be improved.

A free piston 31 was provided in the reservoir chamber 30. The free piston 31 pressurizes the oil in the damper cylinder 103 by gas pressure, and prevents the oil from blowing up from the piston side oil chamber 42B of the damper cylinder 103 to the oil chamber 30A of the reservoir chamber 30 during compression. Prevents cavitation where air is mixed in oil,
Delay in the generation of damping force during compression following elongation (spilling)
Also avoid.

With the communication hole 27 provided in the reservoir tube 102 provided immediately below the partition member 25, the pump rod 61
Through the partition member 25 and its penetrating end (suction port 64A)
Can be provided near the bottom of the low-pressure chamber 26. That is,
By setting the suction port 64 </ b> A of the pump rod 61 near the bottom of the low-pressure chamber 26, even if the air in the low-pressure tank chamber 23 mixes with the oil and this air enters the low-pressure chamber 26, It stays in the upper part of the chamber 2626, is not sucked into the suction port 64A of the pump rod 61, and does not enter the damper cylinder 103. The air staying in the upper part of the low-pressure chamber 26 returns to the low-pressure tank chamber 23 from a communication hole 27 provided in the reservoir pipe 102.

Incidentally, the intrusion of air into the damper cylinder 103 causes a delay in generating the damping force (sloping) and a malfunction in adjusting the vehicle height.

The air that has entered the damper cylinder 103 moves to the low-pressure chamber 26 together with oil returning from the suction passage 64 of the pump rod 61 to the low-pressure chamber 26 by adjusting the vehicle height. It is discharged to the low-pressure tank chamber 23 through the communication hole 27 provided in the pipe 102.

The low pressure chamber 26 described above is connected to the reservoir tube 102.
A communication hole 28 communicating with the reservoir chamber 30 is provided together with a communication hole 27 that communicates with the communication hole 27, and these communication holes 27 and 28 can be opened and closed by the above-described valve body 29. Accordingly, when the oil chambers 42A and 42B in the damper cylinder 103, the low-pressure chamber 26 and the reservoir chamber 30 in the reservoir tube 102 are filled with oil during the assembly of the above-described damper subassembly 104, these communication holes 27 and 28 are filled. Air can be vented in the open state. After filling with oil and bleeding air, these communication holes 2
7 and 28 are closed by a valve body 29.

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 can be changed without departing from the scope of the present invention. The present invention is also included in the present invention.

[0057]

As described above, according to the present invention, in a damper with a vehicle height adjusting mechanism in which a reservoir chamber and a low-pressure tank chamber are attached to a damper cylinder, the structure can be simplified and the assemblability can be improved. .

[Brief description of the drawings]

FIG. 1 is a sectional view showing a damper.

FIG. 2 is an enlarged view of a lower portion of a damper.

FIG. 3 is an enlarged top view of a damper.

FIG. 4 is a sectional view showing a subassembly of the damper.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Damper 11 Piston rod 23 Low-pressure tank chamber 25 Partition member 26 Low-pressure chamber 27, 28 Communication hole 29 Valve 30 Reservoir chamber 30A Oil chamber 30B Gas chamber 31 Free piston 41 Piston 42A, 42B Oil chamber 60 Pump device 61 Piston rod 62 Pump Chamber 63 Pump tube 64 Suction path 64A Suction port 65 Suction check valve 66 Discharge path 67 Discharge check valve 101 Outer tube 101A Operation unit 102 Reservoir tube 103 Damper cylinder 104 Damper sub-assembly

Claims (5)

[Claims] 1. Inserting a reservoir tube into an outer tube,
A triple pipe structure with a damper cylinder inserted into the reservoir pipe, a piston rod inserted into the damper cylinder, two oil chambers defined in the damper cylinder by the piston attached to the piston rod, and a damper inside the reservoir pipe A reservoir chamber communicating with one of the oil chambers of the cylinder and a low-pressure chamber separated from those oil chambers are defined.A low-pressure tank chamber communicating with the low-pressure chamber of the reservoir pipe is defined inside the outer tube. In a damper having a vehicle height adjusting mechanism having a pump device for supplying oil in a tank chamber into a damper cylinder, a communication hole communicating with a low-pressure chamber of the reservoir pipe is opened on the outer periphery of the reservoir pipe, and A valve body for opening and closing the communication hole is provided on the outer periphery, and an operation unit provided in the outer tube connects the valve body to the connection tube when the reservoir tube is inserted into the outer tube. Vehicle height adjusting mechanism with a damper, characterized in that a settable to open position from the closed position for the holes. 2. The pump device according to claim 1, wherein the pump device is fixed to a partition member forming a low-pressure chamber inside the reservoir pipe, is erected in a damper cylinder, and slides on a pump tube inserted into a hollow portion of a piston rod. A pump rod fitted to form a pump chamber in the pump tube; a suction path provided on the pump rod and communicating the low-pressure tank chamber with the pump chamber via a low-pressure chamber of the reservoir pipe; and a suction path provided on the suction path. A suction check valve that allows only the flow of oil from the low-pressure tank chamber to the pump chamber; a discharge path provided on the pump rod, which communicates the pump chamber with the oil chamber of the cylinder; and a discharge path provided on the discharge path. A discharge check valve that allows only the flow of oil from the pump chamber to the oil chamber of the damper cylinder is provided between the pump rod and the pump tube. A standard passage for connecting the pump chamber to the oil chamber in the cylinder when the rod extends to a predetermined standard vehicle height position, and a damper cylinder when the piston rod further extends to a predetermined standard vehicle height position. And a return passage for conducting the oil chamber inside.
A damper with a vehicle height adjustment mechanism as described. 3. The reservoir according to claim 1, wherein the reservoir has a free piston, and the free piston divides the reservoir into an oil chamber and a gas chamber, and pressurizes oil in the oil chamber by gas pressure in the gas chamber. 2. The damper with a vehicle height adjusting mechanism according to 2. 4. The damper with a vehicle height adjusting mechanism according to claim 2, wherein a suction port of the pump rod is set near a bottom of the low-pressure chamber. 5. The vehicle height according to claim 1, wherein a communication hole through which the reservoir pipe communicates with the reservoir chamber also opens on the outer periphery of the reservoir pipe, and the valve body can open and close the communication hole. Damper with adjustment mechanism.