JP2023007996A - Buffer with vehicle height adjustment function - Google Patents

Abstract

To provide a buffer with a vehicle height adjustment function, capable of reducing the number of components and a weight.SOLUTION: A buffer D with a vehicle height adjustment function comprises: a cylinder 1; a housing 2 that has a bottom part 20 and a cylindrical part 21, and in which one end of the cylinder 1 is inserted into the cylindrical part 21; a gas-liquid separator 3 that is inserted into the cylindrical part 21 of the housing 2 so as to be movable to a bottom side with respect to the cylinder 1, and partitions the inside of the housing 2 into an air chamber G and a space S communicating with the inside of the cylinder 1; a piston 4 that is movably inserted into the cylinder 1, and partitions the inside of the cylinder 1 into an expansion side chamber R1 and a compression side chamber R2; a rod 5 that is movably inserted into the cylinder 1, and is connected to the piston 4; a jack piston 15 that is inserted movably in an axial direction into a jack chamber 6 formed between the cylinder 1 and the cylindrical part 21 of the housing 2 in a radial direction; and a suspension spring bearing 8 that supports one end of a suspension spring 7, and is driven by the jack piston 15.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a shock absorber with a vehicle height adjustment function.

This type of shock absorber with a vehicle height adjustment function includes, for example, an outer shell and a piston rod axially movably inserted into the outer shell to generate a damping force when the piston rod moves relative to the cylinder. a shock absorber main body, an annular upper spring bearing slidably mounted on the outer periphery of the outer shell, a lower spring bearing mounted on the tip of the piston rod, an upper spring bearing and a lower spring A suspension spring interposed between a shock absorber and biasing the shock absorber body in the extension direction, and a hydraulic jack attached to the outer periphery of an outer shell and driving the spring bearer in the axial direction, comprising a vehicle body and wheels. (see, for example, Patent Document 1).

Specifically, the hydraulic jack is provided with a cylindrical housing that is arranged on the outer periphery of the outer shell and forms a jack chamber that is an annular gap between the outer shell and the inner periphery of the housing and the outer periphery of the outer shell. It has an annular jack piston that slides in and out of the jack chamber, a pump that supplies and discharges pressure oil to and from the jack chamber via a hose, and a tank that stores hydraulic oil.

When the pump is operated to discharge pressure oil from the jack chamber in the hydraulic jack to the tank, the hydraulic jack contracts to move the upper spring bearing along the outer circumference of the outer shell toward the side opposite to the piston rod. When the pump is actuated to supply pressure oil from the tank into the jack chamber, the hydraulic jack extends to move the spring bearing along the outer circumference of the outer shell toward the piston rod.

Therefore, the damper with a vehicle height adjustment function can adjust the height of the vehicle body (vehicle height) by changing the position of the spring bearing with respect to the outer shell by driving the hydraulic jack.

JP 2015-117812 A

As described above, the conventional shock absorber with a vehicle height adjustment function requires fixing of the hydraulic jack to the outer shell because the hydraulic jack is mounted on the outer periphery of the outer shell.

In addition, if the hydraulic jack rotates about the longitudinal axis of the outer shell with respect to the outer shell, the hose connection points of the hydraulic jack will become different when the shock absorber with vehicle height adjustment function is installed on the vehicle. Since it is troublesome to install the hydraulic jack in a vehicle, it is necessary to provide a detent to prevent the hydraulic jack from rotating around its axis in the conventional shock absorber with a vehicle height adjustment function.

As described above, the conventional shock absorber with a vehicle height adjustment function has the problem that the number of parts increases and the weight increases because the hydraulic jack must be fixed and detented.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a shock absorber with a vehicle height adjustment function that can reduce the number of parts and weight.

In order to solve the above-described problems, a shock absorber with a vehicle height adjustment function according to the problem solving means of the present invention includes a housing having a cylinder, a bottom portion and a cylindrical portion into which one end of the cylinder is inserted, a gas-liquid separator movably inserted into the cylindrical portion of the housing toward the bottom side of the cylinder and dividing the inside of the housing into an air chamber and a space communicating with the cylinder; into an expansion side chamber and a compression side chamber, a rod movably inserted into the cylinder and connected to the piston, and a jack chamber formed between the cylinder and the cylindrical portion of the housing in the radial direction It comprises a jack piston inserted movably in the axial direction, and a suspension spring bearing that supports one end of a suspension spring and is driven by the jack piston.

In the shock absorber with a vehicle height adjustment function configured in this way, a jack chamber is formed between the cylinder and the housing that accommodates the gas-liquid separator and constitutes the pressure vessel of the shock absorber main body together with the cylinder, Since the jack body is integrally and inseparably provided with the shock absorber body, there is no need to attach a separate hydraulic jack to the outer periphery of the cylinder unlike the conventional shock absorber with vehicle height adjustment function.

In addition, the shock absorber with a vehicle height adjustment function includes a sub-cylinder that covers the outer circumference of one end of the cylinder and is arranged on the inner circumference of the cylindrical portion of the housing, and the jack chamber is formed by the gap between the sub-cylinder and the cylindrical portion. may be The shock absorber with a vehicle height adjustment function configured in this way can reduce the manufacturing man-hours and costs, and can also eliminate the trouble of being forced to make many design changes when changing the cross-sectional area of the jack chamber.

In addition, the sub-cylinder in the shock absorber with vehicle height adjustment function may have a flange on its outer periphery for preventing the jack piston from coming off from the jack chamber, and the flange may have a groove on its outer periphery for engagement with a tool. According to the shock absorber with a vehicle height adjustment function configured in this way, the flange can be used not only for retaining the jack piston but also for connecting the cylinder and the housing to the sub-cylinder.

Furthermore, the suspension spring receiver in the shock absorber with a vehicle height adjustment function includes an annular seat portion that supports one end of the suspension spring, and one that extends from the inner periphery to the outer periphery of the surface of the seat portion that faces the end surface of the cylindrical portion of the housing. or more grooves. According to the shock absorber with a vehicle height adjustment function configured in this way, even if the seat portion abuts against the tubular portion, the gap between the jack piston and the tubular portion communicates outward through the groove. Dust, such as water and dust, that has entered the gap through the opening can be discharged to the outside, and the dust is prevented from being pushed into the jack chamber by the suspension spring support.

In addition, the gas-liquid separator in the shock absorber with vehicle height adjustment function is a free piston that slides on the inner circumference of the cylindrical portion of the housing. It may have a large diameter. According to the shock absorber with a vehicle height adjustment function configured in this way, even if a structure in which the free piston is accommodated inside the housing connected to the cylinder is adopted, the stroke length of the piston relative to the cylinder can be reduced while the overall length is shortened. can be ensured.

Further, the housing in the height adjustable shock absorber may include a connection port for supplying and discharging liquid into the jack chamber and a bracket for mounting to the vehicle. According to the shock absorber with a vehicle height adjustment function constructed in this way, since the positions of the bracket and the connection port provided in the housing forming the jack chamber are predetermined, the bracket is used to attach the housing to the vehicle. Direct attachment allows the connection port to be positioned at the optimum position for attachment of the connection pipe, and facilitates attachment to the vehicle and connection to a pump installed in the vehicle.

According to the shock absorber with vehicle height adjustment function of the present invention, the number of parts and weight can be reduced.

It is a diagram showing a shock absorber with a vehicle height adjustment function in one embodiment. 1 is a partially enlarged cross-sectional view of a shock absorber with a vehicle height adjustment function according to one embodiment; FIG. FIG. 10 is a diagram showing a shock absorber with a vehicle height adjustment function in a modified example of one embodiment;

The present invention will be described below based on each embodiment shown in the drawings. As shown in FIGS. 1 and 2, a shock absorber D with a vehicle height adjustment function according to one embodiment is movable within a cylinder 1, a cylindrical housing 2 into which one end of the cylinder 1 is inserted, and the housing 2. A free piston 3 as a gas-liquid separator that is inserted into the housing 2 and partitions the inside of the housing 2 into an air chamber G and a space S that communicates with the cylinder 1, and a free piston 3 that is movably inserted into the cylinder 1 and extends inside the cylinder 1. A piston 4 partitioned into R1 and a pressure side chamber R2, a rod 5 movably inserted into the cylinder 1 and connected to the piston 4, and a jack chamber 6 formed between the cylinder 1 and the housing 2. It comprises a jack piston 15 inserted movably in the axial direction, and a suspension spring bearing 8 that supports one end of the suspension spring 7 and is driven by the jack piston 15 .

Although not shown, the shock absorbers D with a vehicle height adjustment function are installed horizontally between the vehicle body and the links connected to the knuckles that support the wheels of the vehicle. The generated damping force suppresses vibration between the vehicle body and the wheels, and the height of the vehicle body (vehicle height) can be adjusted by moving the suspension spring bearing 8 in the axial direction with respect to the cylinder 1 . Note that the shock absorber D with a vehicle height adjustment function is not limited to automobiles, and may be used in other vehicles such as motorcycles, and may be used vertically with respect to the vehicle.

Each part of the shock absorber D with a vehicle height adjustment function will be described in detail below. The cylinder 1 is cylindrical and has a threaded portion 1a on its outer periphery, and a cylindrical sub-cylinder 9 and a cylindrical housing 2 are attached to the outer periphery of the right end in FIG. The sub-cylinder 9 has a small diameter portion 9a having an inner diameter smaller than the inner diameter of the cylinder 1 at the right end in FIG. It has a flange 9c provided on the outer periphery at the left end in FIG. 1, which is the end, and a screw portion 9d provided on the inner periphery. The sub-cylinder 9 has an axial length shorter than that of the cylinder 1, and is attached to the outer circumference of the cylinder 1 at one end side by screwing the inner circumference screw portion 9d into the screw portion 1a provided on the outer circumference of the cylinder 1. be done. 1, the small-diameter portion 9a of the sub-cylinder 9 is in contact with the stepped portion of the cylinder 1. When the sub-cylinder 9 is screwed to the cylinder 1, the screw portion 1a and the screw portion 9d are axially connected. By applying a load in the direction, the cylinder 1 and the sub-cylinder 9 can be firmly connected. A flange 9c provided on the outer circumference of the other end of the sub-cylinder 9 is provided with a plurality of grooves 9e which are provided at regular intervals in the circumferential direction and which can be gripped by a tool (not shown). can apply a large tightening torque to the sub-cylinder 9 with respect to the cylinder 1 by using a tool for gripping the flange 9c, and the sub-cylinder 9 can be easily attached to the cylinder 1.

The inner periphery of the sub-cylinder 9 on the other end side of the small diameter portion 9a can be fitted to the outer periphery of the cylinder 1, and the sub-cylinder 9 is attached to the cylinder 1 without backlash. A seal ring 10 is mounted on the inner circumference of the sub-cylinder 9 and between the threaded portion 9d and the small diameter portion 9a, and the seal ring 10 seals between the sub-cylinder 9 and the cylinder 1. . A seal ring may be mounted on the outer periphery of the cylinder 1 on the one end side of the threaded portion 1a, but the seal ring needs to climb over the threaded portion 9d in the process of inserting the cylinder 1 into the sub-cylinder 9. Therefore, it is preferable to provide the seal ring on the sub-cylinder 9 side from the viewpoint of protection of the seal ring.

An annular valve case 11 is fitted to the inner circumference of the small diameter portion 9a of the sub-cylinder 9. The valve case 11 comprises an outer circumference nut 12 screwed onto the inner circumference of the small diameter portion 9a and an inner circumference flange. 9b and fixed to the sub-cylinder 9.

The housing 2 has a cylindrical shape with a bottom and includes a bottom portion 20 and a cylindrical portion 21 . The bottom part 20 has a bracket 20a at its end which can be connected to the body of the vehicle. The cylindrical portion 21 includes a jack cylindrical portion 21a having an inner diameter larger than the outer diameter of the sub-cylinder 9 and accommodating one end of the cylinder 1 on the inner peripheral side, and a jack cylindrical portion 21a provided closer to the bottom portion 20 than the jack cylindrical portion 21a. has a larger diameter than the inner diameter of the cylinder 1 and communicates with the inside of the cylinder 1 to form a reservoir R; and an intermediate tubular portion 21c connecting the reservoir tubular portion 21b.

A threaded portion 21d is provided on the inner periphery of the intermediate cylindrical portion 21c, and a threaded portion 9e provided on the outer periphery of the small diameter portion 9a of the sub-cylinder 9 that is inserted into the housing 2 from the jack cylindrical portion 21a side of the housing 2. The housing 2 is connected to the cylinder 1 via the sub-cylinder 9 by screwing the threaded portion 21 d to the housing 2 . In addition, the inner diameter of the right end side in FIG. 1, which is one end side of the intermediate cylindrical portion 21c, is reduced in the middle, and a stepped portion 21e that contacts one end portion of the sub-cylinder 9 is provided on the inner circumference of the intermediate cylindrical portion 21c. ing. Therefore, when the housing 2 is screwed to the sub-cylinder 9, the sub-cylinder 9 and the housing 2 can be firmly connected by applying a load in the axial direction to the screw portion 9e and the screw portion 21d. A recessed portion 21k is provided on the outer periphery of the intermediate tubular portion 21c for the purpose of reducing the weight of the shock absorber D with a vehicle height adjustment function, but the recessed portion 21k may not be provided.

When the housing 2 is connected to the cylinder 1 in this way, one end of the cylinder 1 is inserted halfway into the tubular portion 21 of the housing 2, and the jack tubular portion 21a is located on the right end side in FIG. A jack chamber 6 is formed by an annular clearance between the jack tubular portion 21 a and the sub-cylinder 9 . Further, when the housing 2 is connected to the cylinder 1, the inside of the reservoir cylindrical portion 21b is communicated with the inside of the cylinder 1. As shown in FIG. A free piston 3, which is a gas-liquid separator, is inserted into the reservoir cylinder portion 21b so as to be movable in the axial direction of the reservoir cylinder portion 21b. The free piston 3 is in sliding contact with the inner circumference of the reservoir cylinder portion 21b, and divides the inside of the reservoir cylinder portion 21b into an air chamber G filled with gas and a space S which communicates with the cylinder 1 and is filled with liquid. there is Note that the reservoir R is composed of a space S and an air chamber G. As shown in FIG. The gas-liquid separator may be anything that can separate the air chamber G filled with gas and the space S filled with liquid in the housing 2. Therefore, in addition to the free piston 3, a bellows, a diaphragm, a bladder, and the like may also be used. may be

The air chamber G contains a gas that pressurizes the inside of the cylinder 1 via the space S. As shown in FIG. The gas enclosed in the air chamber G is preferably an inert gas such as nitrogen, but may be air or other gas.

Thus, in the damper D with a vehicle height adjustment function of the present embodiment, the cylinder 1 and the housing 2 accommodating the free piston 3 as the gas-liquid separator form a pressure vessel for functioning as a damper. It constitutes a shock absorber main body together with the piston 4 and the rod 5 .

A seal ring 14 is attached to the inner periphery of the intermediate cylindrical portion 21c to closely contact the outer periphery of the sub-cylinder 9. The seal ring 14 seals the space between the housing 2 and the sub-cylinder 9, thereby Communication with reservoir R is broken.

The intermediate cylindrical portion 21c of the housing 2 is provided with an injection hole 21f that opens from a portion facing the space S in the radial direction, penetrates through the wall thickness, and communicates with the outer periphery. After the liquid injection hole 21f is used for injecting the liquid into the cylinder 1 and the space S, it is closed by a plug 22 screwed to the intermediate cylindrical portion 21c. In addition, as shown in FIG. 2, the jack tube portion 21a has a connection port 21g that penetrates the inner and outer circumferences and communicates with the jack chamber 6 on the right end side in FIG. 21h is provided at the position of and closed with a plug (not shown).

21 g of connection ports are ports for connecting the connection piping 13 extended from the pump P installed in the vehicle. Although not shown, the connection port 21g is formed with a female screw on the inner periphery thereof, and a joint component that is joined to a joint provided at the end of the connection pipe 13 is screwed and attached. The pump P can supply liquid to the jack chamber 6 from a tank T installed in the vehicle, and can discharge liquid from the jack chamber 6 to the tank T. Therefore, by driving the pump P, liquid can be supplied to and discharged from the jack chamber 6 through the connection port 21 g and the connection pipe 13 .

A cylindrical jack piston 15 is inserted between the sub-cylinder 9 and the jack cylinder portion 21 a of the housing 2 so as to be in sliding contact with the outer circumference of the sub-cylinder 9 and the inner circumference of the jack cylinder portion 21 a. The left end opening is closed by the jack piston 15 in FIG. As shown in FIG. 2, the jack piston 15 is provided with annular grooves 15a and 15b provided along the circumferential direction at two locations on the inner periphery, and an annular suspension spring bearing 8 is integrally provided at the left end in FIG. It is The annular groove 15a on the atmosphere side of the jack piston 15 accommodates an annular dust seal 16 that slides on the outer periphery of the sub-cylinder 9, and the annular groove 15b on the side of the jack chamber opposite to the atmosphere of the jack piston 15 accommodates the sub-cylinder. A ring-shaped U-packing 17 is accommodated in sliding contact with the outer circumference of 9 .

Furthermore, as shown in FIG. 2, annular grooves 21i and 21j are provided at two locations on the inner periphery of the jack cylinder portion 21a of the housing 2 along the circumferential direction. An annular dust seal 18 that slides on the outer periphery of the jack piston 15 is accommodated in an annular groove 21i on the atmosphere side of the jack cylinder portion 21a. An annular U-packing 19 is accommodated in sliding contact with the outer circumference of the jack piston 15 .

Therefore, the space between the sub-cylinder 9 and the jack piston 15 is sealed by the U-packing 17, and the space between the housing 2 and the jack piston 15 is sealed by the U-packing 19 to prevent liquid leakage from the jack chamber 6. Furthermore, the dust seal 16 and the dust seal 18 prevent water, dust, etc. from entering the jack chamber 6 . In addition, in the shock absorber D with the vehicle height adjustment function of the present embodiment, the jack chamber 6 is annular and the jack piston 15 is also cylindrical. Well, if the cross-sectional shape of the jack piston 15 matches the cross-sectional shape of the jack chamber 6 and the opening of the jack chamber 6 can be closed by the jack piston 15, it does not have to be annular.

The suspension spring receiver 8 is integrated with the left end of the jack piston 15 in FIG. A guide cylinder 8 b is fitted to the inner periphery of the suspension spring 7 and connected to the jack piston 15 at one end. Although the suspension spring receiver 8 is formed as one part with the jack piston 15 , it may be a separate part that can be separated from the jack piston 15 .

The guide tube 8b has an inner diameter larger than the outer diameter of the flange 9c of the sub-cylinder 9, allowing the flange 9c to pass therethrough. The jack piston 15 can move axially relative to the housing 2 and the sub-cylinder 9, but faces the flange 9c in the axial direction. further exit is restricted. In this manner, the flange 9c not only enables a tool to be gripped when the cylinder 1 and the sub-cylinder 9 are screwed together, but also functions as a restricting portion that prevents the jack piston 15 from falling out of the jack chamber 6. . Also, when the jack piston 15 moves out of the jack chamber 6 , dust such as water and dust adhering to the outer circumference of the sub-cylinder 9 is scraped off by the dust seal 16 on the inner circumference of the jack piston 15 . Even if the flange 9c abuts on the jack piston 15, the scraped dust is communicated outwardly through the groove 9e in the space between the sub-cylinder 9 and the jack piston 15 on the atmosphere side of the dust seal 16. Therefore, it is discharged to the outside through the groove 9e. Therefore, even if the jack piston 15 repeatedly reciprocates in the axial direction and comes into contact with the flange 9c, the dust scraped off by the dust seal 16 accumulates in the gap and is not pushed into the jack chamber 6 by the flange 9c. no.

Further, when the jack piston 15 is fully inserted into the jack chamber 6, the seat portion 8a abuts against the left end of the jack tube portion 21a of the housing 2 in FIG. Regulate intrusions. A plurality of grooves 8c extending from the inner circumference to the outer circumference are radially provided at equal intervals in the circumferential direction on the surface of the seat portion 8a facing the end surface (the left end surface in FIG. 1) of the jack tube portion 21a. . When the jack piston 15 operates to enter the jack chamber 6, dust such as water and dust adhering to the outer periphery of the jack piston 15 is scraped off by the dust seal 18 on the inner periphery of the jack cylindrical portion 21a. Even if the seat portion 8a abuts against the jack cylinder portion 21a, the scraped dust is communicated outwardly through the groove 8c in the gap between the jack piston 15 and the jack cylinder portion 21a on the atmosphere side of the dust seal 18. Therefore, it is discharged to the outside through the groove 8c. Therefore, even if the suspension spring bearing 8 repeatedly reciprocates in the axial direction and comes into contact with the jack tube portion 21a, the dust scraped off by the dust seal 18 accumulates in the gap, and the suspension spring bearing 8 causes the jack chamber 6 to move. You can't get pushed inside.

When the pump P is driven to supply liquid from the tank T into the jack chamber 6, the liquid supplied into the jack chamber 6 pushes the jack piston 15 against the urging force of the suspension spring 7, thereby pushing the jack chamber. Move in the direction of exit from 6. Along with the movement of the jack piston 15, the suspension spring bearing 8 integrated with the jack piston 15 also moves leftward in FIG. Conversely, when the pump P is driven to discharge the liquid from the jack chamber 6 to the tank T, the jack piston 15 moves toward the right in FIG. Moving. Therefore, in the shock absorber D with a vehicle height adjustment function of the present embodiment, the suspension spring bearing 8 can move in the axial direction with respect to the cylinder 1 by supplying and discharging the liquid into the jack chamber 6 by the pump P.

Thus, in the shock absorber D with a vehicle height adjustment function of the present embodiment, the hydraulic jacks for driving the suspension spring bearings 8 are the jack chamber 6 formed between the cylinder 1 and the housing 2 and the jack chamber 6 It is composed of a jack body including a jack piston 15 that moves in and out, a pump P as a supply/discharge means for supplying/discharging liquid into/from the jack chamber 6, and a tank T for storing the liquid. As described above, the jack chamber 6 is formed by the housing 2 which constitutes a part of the pressure vessel of the shock absorber main body. inseparably established.

Next, the piston 4 is inserted into the cylinder 1 so as to be axially movable with respect to the cylinder 1 as described above. The inside of the cylinder 1 is divided by the piston 4 into an expansion side chamber R1 on the left side in FIG. 1 and a compression side chamber R2 on the right side in FIG. The expansion side chamber R1 and the compression side chamber R2 are specifically filled with hydraulic fluid, for example, as a liquid. As the working liquid, other than working oil, for example, liquid such as water or aqueous solution may be used.

The piston 4 is annular, and is assembled with an annular extension damping valve 26 and an annular compression damping valve 27 on the outer periphery of a rod 5 inserted axially movably into the cylinder 1 , and is attached by a piston nut 28 . It is fixed to the rod 5.

Moreover, the piston 4 is provided with the expansion side passage 4a and the compression side passage 4b that connect the expansion side chamber R1 and the compression side chamber R2. In the shock absorber D with a vehicle height adjustment function of the present embodiment, the extension side damping valve 26 is a leaf valve whose inner circumference is fixed to the rod 5 and allows deflection on the outer circumference side. It is stacked on the chamber side and opens and closes the expansion side passage 4a. Specifically, when the expansion side damping valve 26 receives the pressure of the expansion side chamber R1 and bends, it opens the expansion side passage 4a and resists the flow while allowing the flow of liquid from the expansion side chamber R1 toward the compression side chamber R2. , and blocks the flow of the liquid from the compression side chamber R2 to the growth side chamber R1 by closing the growth side passage 4a. The compression side damping valve 27 is a leaf valve whose inner periphery is fixed to the rod 5 and whose outer periphery is allowed to flex. side to open and close the compression side passage 4b. Specifically, when the compression-side damping valve 27 bends under the pressure of the compression-side chamber R2, it opens the compression-side passage 4b to allow the flow of liquid from the compression-side chamber R2 toward the expansion-side chamber R1 while giving resistance to the flow. , the pressure-side passage 4b is closed to block the flow of the liquid from the expansion-side chamber R1 to the pressure-side chamber R2.

An annular rod guide 23 is attached to the other end of the cylinder 1, which is the left end in FIG. The rod guide 23 has a cylindrical bush 23a that slides on the outer circumference of the rod 5 and guides the axial movement of the rod 5 with respect to the cylinder 1. As shown in FIG. An annular seal member 24 is layered on the atmosphere side of the rod guide 23, and the cylinder 1 is secured by a head cap 25 screwed to the outer periphery of the left end in FIG. is fixed to The seal member 24 seals the outer periphery of the rod 5 to prevent liquid from leaking out of the cylinder 1 .

Further, at the tip of the rod 5, a bracket 5a that can be connected to a link that connects the rod 5 to a knuckle that holds a wheel of the vehicle is provided, and a rod-side suspension spring receiver 5b that supports the other end of the suspension spring 7 is provided. is provided. The suspension spring 7 is interposed in a compressed state between the rod-side suspension spring bearing 5b and the seat portion 8a of the suspension spring bearing 8, and the direction in which the rod 5 is withdrawn from the cylinder 1, that is, the vehicle height adjustment. It is biased in the direction of extending the shock absorber D with function. Since the suspension spring receiver 8 is provided with a guide cylinder 8b fitted to the inner circumference of the suspension spring 7, the suspension spring 7 is prevented from being axially misaligned in the radial direction, and the suspension spring 7 interferes with the cylinder 1. is prevented.

As shown in FIG. 2, the valve case 11 fixed to the sub-cylinder 9 has an annular shape and includes a discharge passage 11a that communicates the pressure side chamber R2 and the space S in the reservoir cylindrical portion 21b of the housing 2. and a suction passage 11b. A shaft portion of a guide rod 29 having a shaft portion having a screw portion at its tip and a flange provided at one end of the shaft portion is inserted through the inner circumference of the valve case 11 . An annular base valve 31, a valve case 11, and an annular check valve 30 are assembled in this order from the right in FIG. and a check valve 30 are fixed to the guide rod 29 .

The base valve 31 has an inner circumference fixed to the guide rod 29 and is allowed to flex on the outer circumference side. Specifically, when the base valve 31 bends under the pressure of the pressure-side chamber R2, the discharge passage 11a is opened to allow the flow of liquid from the pressure-side chamber R2 toward the space S in the reservoir R while resisting the flow. The discharge passage 11a is closed to block the flow of the liquid from the space S toward the pressure-side chamber R2. The inner periphery of the check valve 30 is fixed to the guide rod 29 so that the outer periphery thereof is allowed to flex. Specifically, the check valve 30 bends under the pressure of the space S to open the suction passage 11b and allow the flow of liquid from the space S toward the pressure-side chamber R2 without much resistance. The suction passage 11b is closed to block the flow of the liquid from R2 toward the space S.

The shock absorber D with a vehicle height adjustment function of this embodiment is configured as described above, and the operation of the shock absorber D with a vehicle height adjustment function will be described below. First, the operation when the shock absorber D with the vehicle height adjustment function expands and contracts will be described. When the shock absorber D with a vehicle height adjustment function is extended and the rod 5 and the piston 4 move leftward in FIG. The pressure side chamber R2 is enlarged. The liquid in the contraction-side chamber R1 passes through the contraction-side passage 4a of the piston 4, bends the contraction-side damping valve 26, and moves to the expansion-side chamber R2. Since the growth side damping valve 26 gives resistance to the flow of the liquid passing through the growth side passage 4a, the pressure in the growth side chamber R1 rises and becomes higher than the pressure in the compression side chamber R2.

In addition, when the shock absorber D with the vehicle height adjustment function is extended, the rod 5 is withdrawn from the cylinder 1, so that the liquid in the cylinder 1 runs short, but the check valve 30 is opened to absorb the shortfall of liquid. It is supplied from the reservoir R to the pressure side chamber R2 through the passage 11b. Since the liquid moves from the space S of the reservoir R to the compression side chamber R2, the free piston 3 moves leftward in FIG. In this way, the reservoir R compensates for the volume of the rod 5 withdrawing from the cylinder 1 due to the extension operation of the shock absorber D with the vehicle height adjustment function. As described above, the pressure in the compression side chamber R2 becomes almost equal to the pressure in the reservoir R, a difference occurs between the pressure in the expansion side chamber R1 and the pressure in the compression side chamber R2, and the shock absorber D with the vehicle height adjustment function A damping force that hinders the extension operation is generated in accordance with the difference between the pressure in R1 and the pressure in compression side chamber R2.

Further, the operation when the shock absorber D with the vehicle height adjustment function is retracted will be described. When the shock absorber D with a vehicle height adjustment function contracts and moves the rod 5 and the piston 4 to the right in FIG. The expansion side chamber R1 is enlarged. The liquid in the reduced pressure-side chamber R2 passes through the pressure-side passage 4b of the piston 4, bends the compression-side damping valve 27, and moves to the expanded expansion-side chamber R1.

In addition, when the shock absorber D with the vehicle height adjustment function is contracted, the rod 5 enters the cylinder 1, so the liquid in the cylinder 1 is excessive, but the excess liquid is discharged by opening the base valve 31. It is discharged from the pressure side chamber R2 to the reservoir R through the passage 11a. Since the pressure damping valve 27 and the base valve 31 provide resistance to the liquid flowing through the pressure side passage 4b and the discharge passage 11a, the pressure in the pressure side chamber R2 rises and becomes higher than the pressure in the expansion side chamber R1. Since the volume of liquid that the rod 5 intrudes into the cylinder 1 moves into the space S from the pressure side chamber R2, the free piston 3 moves rightward in FIG. In this manner, the reservoir R compensates for the volume of the rod 5 entering the cylinder 1 due to the contraction of the shock absorber D with the vehicle height adjustment function.

As described above, the pressure in the compression-side chamber R2 becomes higher than the pressure in the expansion-side chamber R1, and a difference occurs between the pressure in the compression-side chamber R2 and the pressure in the expansion-side chamber R1. A damping force that prevents contraction is generated according to the difference between the pressure of R2 and the pressure of expansion side chamber R1.

Instead of the compression-side damping valve 27, a check valve that does not give much resistance to the flow of the passing liquid may be used to open and close the compression-side passage 4b. In this case, since the check valve does not give much resistance, the pressure in both the expansion side chamber R1 and the compression side chamber R2 in the cylinder 1 is almost Although the pressure rises to the same level, the pressure-receiving area on the compression-side chamber side of the piston 4 is larger than the pressure-receiving area on the expansion-side chamber side, so the shock absorber D with a vehicle height adjustment function generates a damping force that prevents contraction.

Further, in the present embodiment, the valve case 11, the base valve 31 and the check valve 30 are provided to separate the inside of the cylinder 1 from the reservoir R, but the valve case 11, the base valve 31 and the check valve 30 are May be abolished. In this case, the shock absorber D with a vehicle height adjustment function has the same configuration as a so-called single-tube shock absorber, so that the extension side damping valve 26 generates a damping force that hinders the extension operation during the extension operation, and generates a damping force that hinders the extension operation during the retraction operation. The compression side damping valve 27 can generate a damping force that prevents the contraction operation. The extension side damping valve 26, the compression side damping valve 27 and the base valve 31 are all leaf valves. It may be a structural valve.

Next, the operation of the shock absorber D with a vehicle height adjustment function when adjusting the vehicle height will be described. When the vehicle height is raised by the damper D with the vehicle height adjustment function, the pump P is driven to supply the liquid into the jack chamber 6 . When the liquid is supplied from the pump P to the jack chamber 6, the jack piston 15 moves in the direction of withdrawing from the jack chamber 6, so that the suspension spring bearing 8 moves leftward with respect to the cylinder 1 in FIG. The support position of the suspension spring 7 is displaced. Suspension springs 7 are compressed in a state in which shock absorbers D with a vehicle height adjustment function are interposed between the vehicle body and the wheels, and provide an elastic force equivalent to supporting the wheel load that the wheels receive from the vehicle body. Therefore, even if the suspension spring bearing 8 moves leftward in FIG. Therefore, when the suspension spring bearing 8 moves to the left in FIG. is increased by the product of the displacement amount of the rod 5 and the lever ratio of the link. When the liquid is supplied from the pump P to the jack chamber 6 in this way, the suspension spring bearing 8 is displaced according to the amount of liquid supplied to the jack chamber 6, so the shock absorber D with the vehicle height adjustment function is can be raised.

On the other hand, when the vehicle height is lowered by the shock absorber D with the vehicle height adjustment function, the pump P is driven to discharge the liquid from the inside of the jack chamber 6 . When the liquid is discharged from the jack chamber 6, the jack piston 15 enters the jack chamber 6 according to the amount of liquid discharged, and the suspension spring support 8 moves rightward with respect to the cylinder 1 in FIG. to displace the support position of the suspension spring 7. When the suspension spring bearing 8 moves to the right in FIG. It is lowered by a value obtained by multiplying the amount of displacement by the lever ratio of the link. In this way, when the liquid is discharged from the jack chamber 6 by the pump P, the suspension spring bearing 8 is displaced according to the amount of liquid discharged from the jack chamber 6. You can lower the ride height. The suspension spring receiver 8 always receives a load equal to the weight of the vehicle body that the suspension spring 7 bears from the suspension spring 7 and urges the jack piston 15 in the direction of contracting the jack chamber 6 . Therefore, a passage that bypasses the pump P and communicates between the jack chamber 6 and the tank T that stores the liquid, and an on-off valve that opens and closes the passage are provided, and instead of driving the pump P, the on-off valve is opened. , the liquid may be discharged from the jack chamber 6 to the tank T to lower the vehicle height. Even if the shock absorber D with the vehicle height adjustment function is constructed in this way, when the on-off valve is opened, the jack piston 15 is pushed into the jack chamber 6 by the elastic force received from the suspension spring 7, and the jack chamber is closed. Since the liquid can be automatically discharged from 6 to the tank T, the vehicle height can be lowered.

The shock absorber D with a vehicle height adjustment function according to the present embodiment includes a cylinder 1, a housing 2 having a bottom portion 20 and a cylindrical portion 21 into which one end of the cylinder 1 is inserted; a free piston (gas-liquid separator) 3 which is movably inserted into the cylindrical portion 21 of the cylindrical portion 21 toward the bottom side of the cylinder 1 and divides the housing 2 into an air chamber G and a space S communicating with the cylinder 1; A piston 4 that is movably inserted into the cylinder 1 and divides the inside of the cylinder 1 into an expansion side chamber R1 and a compression side chamber R2, a rod 5 that is movably inserted into the cylinder 1 and is connected to the piston 4, a diameter A jack piston 15 is axially movably inserted into a jack chamber 6 formed between the cylinder 1 and the cylindrical portion 21 of the housing 2, and the jack piston 15 supports one end of the suspension spring 7. and a suspension spring bearing 8 driven by

In the shock absorber D with a vehicle height adjustment function configured in this way, between the cylinder 1 and the housing 2 which accommodates the free piston (gas-liquid separator) 3 and constitutes the pressure vessel of the shock absorber body together with the cylinder 1, A jack chamber 6 is formed in the body of the shock absorber, and the jack body is integrally and inseparably provided with the shock absorber body. need not be installed. Therefore, according to the shock absorber D with the vehicle height adjustment function of the present embodiment, since the jack body is integrally and inseparably provided with the shock absorber body, the hydraulic jack can be fixed and detented with respect to the shock absorber body. no longer need to. As described above, according to the shock absorber D with the vehicle height adjustment function of the present embodiment, compared to the conventional shock absorber with the vehicle height adjustment function, the fixing and detent of the hydraulic jack are unnecessary, and the number of parts is reduced. can be reduced and the weight can be reduced.

Since the jack chamber 6 only needs to be formed between the cylinder 1 and the housing 2, it can be positioned between the sub-cylinder 9 and the housing 2 like the shock absorber D with vehicle height adjustment function of the present embodiment. A jack chamber 6 may be formed in the gap. In addition, in the shock absorber D with vehicle height adjustment function of the present embodiment, the gap between the sub-cylinder 9 and the housing 2 forms the jack chamber 6, but as shown in FIG. A gap between the cylinder 1 and the tubular portion 21 of the housing 2 forms a jack chamber 6, and the jack piston 15 is slidably contacted with the outer circumference of the cylinder 1 and the inner circumference of the jack tubular portion 21a of the housing 2. may be inserted into the jack chamber 6. In order to attach the valve case 11 to the cylinder 1, a small diameter portion 1b and an inner peripheral flange 1c are provided at the right end in FIG. The inner peripheral flange 1c and the outer peripheral nut 33 can hold the valve case 11 therebetween. If the valve case 11 is not provided, it is not necessary to provide the small diameter portion 1b and the inner peripheral flange 1c. When the sub-cylinder 9 is eliminated, it is preferable to provide a threaded portion 1d on the outer periphery of the cylinder 1 and attach an annular stopper 34 to the threaded portion 1d to prevent the jack piston 15 from falling out of the jack chamber 6. The stopper 34 may be a C-pin, in which case an annular groove may be provided on the outer periphery of the cylinder 1 for mounting the C-pin.

Although the jack chamber 6 may be formed in the gap between the cylinder 1 and the housing 2 in this way, the shock absorber D with a vehicle height adjustment function of the present embodiment covers the outer circumference of one end of the cylinder 1. A sub-cylinder 9 is arranged on the inner circumference of the cylindrical portion 21 of the housing 2 , and a jack chamber 6 is formed in a gap between the sub-cylinder 9 and the cylindrical portion 21 . Here, when the jack chamber is formed in the gap between the cylinder 1 and the housing 2 without providing the sub-cylinder 9, the piston 4 is in sliding contact with the inner periphery of the cylinder 1 and the jack piston 15 is in sliding contact with the outer periphery of the cylinder 1. It will be. In this case, since the piston 4 and the jack piston 15 have different displacements and velocities with respect to the cylinder 1, different surface treatments must be applied to the piston sliding surface on the inner periphery of the cylinder 1 and the jack piston sliding surface on the outer periphery. not. Although it is possible to apply different surface treatments to the inner circumference and the outer circumference of the cylinder 1, this results in an increase in processing man-hours and cost. Therefore, the shock absorber D with a vehicle height adjustment function using the sub-cylinder 9 can reduce the manufacturing man-hour and cost. Further, in the shock absorber D with a vehicle height adjustment function using the sub-cylinder 9, the cross-sectional area of the jack chamber 6 can be easily changed by changing the sub-cylinder 9 regardless of the diameter of the cylinder 1. If the diameter of the cylinder 1 is changed, the diameters of the rod 5 and the piston 4 must also be changed according to the diameter of the cylinder 1, and many design changes are forced. Buffer D does not have such troubles.

In addition, in the shock absorber D with vehicle height adjustment function of the present embodiment, the sub-cylinder 9 has a flange 9c on its outer periphery that prevents the jack piston 15 from coming off from the jack chamber 6, and the flange 9c has a tool has a groove 9e capable of engaging the . According to the shock absorber D with a vehicle height adjustment function configured in this way, the flange 9c can be used not only for retaining the jack piston 15 but also for connecting the sub-cylinder 9 with the cylinder 1 and the housing 2.

Furthermore, in the shock absorber D with a vehicle height adjustment function of the present embodiment, the suspension spring receiver 8 includes an annular seat portion 8a that supports one end of the suspension spring 7, and an end face of the cylindrical portion 21 of the housing 2 of the seat portion 8a. and one or more grooves 8c leading from the inner periphery to the outer periphery of the surface facing the . According to the shock absorber D with a vehicle height adjustment function configured in this way, even if the seat portion 8a abuts against the cylindrical portion 21, the gap between the jack piston 15 and the cylindrical portion 21 is maintained outward through the groove 8c. , dust such as water and dust entering the gap through the groove 8c can be discharged to the outside, and the dust is prevented from being pushed into the jack chamber 6 by the suspension spring support 8. In addition, in the shock absorber D with a vehicle height adjustment function of the present embodiment, the grooves 8c provided in the seat portion 8a are radially provided at equal intervals in the circumferential direction of the seat portion 8a. If there is no risk of pushing dust into the jack chamber 6 by 8, it can be abolished. Further, since the groove 8c may be formed from the inner circumference to the outer circumference of the seat portion 8a of the suspension spring receiver 8, the number of grooves to be installed, the position to be installed and the shape thereof can be arbitrarily changed in design.

Further, in the shock absorber D with a vehicle height adjustment function of the present embodiment, the gas-liquid separator is the free piston 3 in sliding contact with the inner circumference of the cylindrical portion 21 of the housing 2, and the free piston of the cylindrical portion 21 of the housing 2 The inner diameter of the movement range of 3 (the inner diameter of the reservoir cylinder portion 21 b ) is larger than the inner diameter of the cylinder 1 . In the damper D with vehicle height adjustment function, when the piston 4 is displaced with respect to the cylinder 1, the rod 5 moves in and out of the cylinder 1, so the free piston 3 is also displaced with respect to the housing 2, and the volume of the air chamber G change. According to the damper D with a vehicle height adjustment function in which the inner diameter of the movement range of the free piston 3 of the cylindrical portion 21 of the housing 2 (the inner diameter of the reservoir cylindrical portion 21b) is larger than the inner diameter of the cylinder 1, the free piston Since the outer diameter of the free piston 3 can be made larger than the outer diameter of the piston 4, the stroke of the free piston 3 can be made smaller than the stroke of the piston 4 with respect to the cylinder 1. can be shortened. Therefore, according to the shock absorber D with a vehicle height adjustment function configured in this way, even if a structure in which the free piston 3 is accommodated inside the housing 2 connected to the cylinder 1 is adopted, the overall length is shortened. A stroke length of the piston 4 with respect to the cylinder 1 can be secured.

Furthermore, in the shock absorber D with a vehicle height adjustment function of the present embodiment, the housing 2 includes a connection port 21g for supplying and discharging liquid into the jack chamber 6, and a bracket 20a that enables attachment to the vehicle. I have. According to the shock absorber D with a vehicle height adjustment function constructed in this way, since the position of the connection port 21g provided in the housing 2 forming the jack chamber 6 and the bracket 20a is predetermined, the bracket 20a is used. If the housing 2 is directly attached to the vehicle, the connection port 21g can be positioned at the optimum position for attachment of the connection pipe 13. As shown in FIG. Therefore, according to the shock absorber D with the vehicle height adjustment function, it becomes easy to attach to the vehicle and to connect with the pump P installed in the vehicle. Since the shock absorber D with a vehicle height adjustment function according to the present embodiment is used in a horizontal position with respect to the vehicle, the air vent hole 21h is formed when the housing 2 is attached to the vehicle using the bracket 20a. is preferably arranged in the housing 2 so as to face upwards. Moreover, the connection port 21g may be located at a position where the worker can easily connect the connection pipe 13 connected to the pump P to the connection port 21g in a state where the shock absorber D with the vehicle height adjustment function is attached to the vehicle. In the case where the shock absorber D with vehicle height adjustment function is installed in the vehicle vertically, when the housing 2 is attached to the vehicle using the bracket 20a, the operator must insert the connection pipe 13 into the connection port 21g. The positional relationship between the bracket 20a and the connection port 21g should be set so that the connection port 21g is arranged at a position where the connection port 21g can be easily connected.

Further, according to the shock absorber D with vehicle height adjustment function of the present embodiment, since the connection port 21g and the air vent hole 21h face upward, the shock absorber D can be easily installed in the hydraulic jack by driving the pump P while it is mounted on the vehicle. can be deflated.

Although preferred embodiments of the invention have been described in detail above, modifications, variations, and changes are possible without departing from the scope of the claims.

DESCRIPTION OF SYMBOLS 1... Cylinder, 2... Housing, 3... Free piston (gas-liquid separator), 4... Piston, 5... Rod, 6... Jack chamber, 7... Suspension spring , 8... Suspension spring receiver, 8a... Seat portion, 8c... Groove, 9... Sub-cylinder, 9c... Flange, 9e... Groove, 15... Jack piston, 20... ..bottom portion 20a...bracket 21...cylinder portion 21g...connection port D...buffer with vehicle height adjustment function G...air chamber S...space R1 ... Expansion side chamber, R2 ... Compression side chamber

Claims (6)

a cylinder;
a housing having a bottom portion and a cylindrical portion into which one end of the cylinder is inserted;
a gas-liquid separator that is movably inserted into the cylindrical portion of the housing closer to the bottom than the cylinder and divides the inside of the housing into an air chamber and a space that communicates with the cylinder;
a piston that is movably inserted into the cylinder and partitions the inside of the cylinder into an expansion-side chamber and a compression-side chamber;
a rod movably inserted into the cylinder and connected to the piston;
a jack piston inserted movably in the axial direction into a jack chamber formed between the cylinder and the cylindrical portion of the housing in the radial direction;
A shock absorber with a vehicle height adjustment function, comprising: a suspension spring support that supports one end of a suspension spring and is driven by the jack piston. a sub-cylinder covering the outer circumference of the one end of the cylinder and arranged on the inner circumference of the tubular portion of the housing;
The shock absorber with a vehicle height adjustment function according to claim 1, wherein the jack chamber is formed in a gap between the sub-cylinder and the cylindrical portion. The sub-cylinder has a flange on its outer periphery that prevents the jack piston from coming off from the jack chamber,
The shock absorber with a vehicle height adjustment function according to claim 2, wherein the flange has a groove on the outer periphery thereof for engagement with a tool. The suspension spring receiver includes an annular seat portion that supports one end of the suspension spring, and one or more grooves extending from the inner periphery to the outer periphery of the surface of the seat portion facing the end surface of the cylindrical portion of the housing. The shock absorber with a vehicle height adjustment function according to any one of claims 1 to 3, characterized by comprising: The gas-liquid separator is a free piston in sliding contact with the inner periphery of the cylindrical portion of the housing,
The shock absorber with a vehicle height adjustment function according to any one of claims 1 to 4, wherein the inner diameter of the movement range of the free piston of the cylindrical portion of the housing is larger than the inner diameter of the cylinder. vessel. The housing is
a connection port for supplying and discharging liquid into and from the jack chamber;
The shock absorber with a vehicle height adjustment function according to any one of claims 1 to 5, further comprising a bracket that enables attachment to a vehicle.

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