Shock absorber with height adjustment function

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]

[0001] The present invention relates to a shock absorber with a vehicle height adjustment function. [Background technology]

[0002] This type of shock absorber with height adjustment function includes, for example, an outer shell and a piston rod inserted in the outer shell so as to be movable in the axial direction. Outer Shell One such shock absorber is mounted between the body and wheels of a vehicle and comprises a shock absorber body that generates a damping force when the piston rod moves relative to the outer shell, an annular upper spring bearing mounted for sliding movement on the outer periphery of the outer shell, a lower spring bearing mounted to the tip of the piston rod, a suspension spring mounted between the upper and lower spring bearings and biasing the shock absorber body in the extension direction, and a hydraulic jack attached to the outer periphery of the outer shell and driving the spring bearing in the axial direction (see, for example, Patent Document 1).

[0003] Specifically, a hydraulic jack comprises a cylindrical housing that is arranged on the outer periphery of an outer shell and forms a jack chamber consisting of an annular gap between the housing and the outer periphery of the outer shell, a ring-shaped jack piston that slides between the housing and the outer periphery of the outer shell and moves in and out of the jack chamber, a pump that supplies and discharges pressurized oil to the jack chamber via a hose, and a tank that stores hydraulic oil.

[0004] When the pump is operated to discharge pressurized oil from the jack chamber in the hydraulic jack to the tank, the hydraulic jack contracts and moves the upper spring bearing along the outer periphery of the outer shell toward the side opposite the piston rod. When the pump is operated to supply pressurized oil from the tank to the jack chamber, the hydraulic jack expands and moves the spring bearing along the outer periphery of the outer shell toward the piston rod.

[0005] Therefore, the shock absorber with height adjustment function can adjust the height of the vehicle body (vehicle height) by changing the position of the spring receiver with respect to the outer shell by driving the hydraulic jack. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2015-117812 A Summary of the Invention [Problem to be solved by the invention]

[0007] As described above, in the conventional shock absorber with height adjustment function, the hydraulic jack is attached to the outer periphery of the outer shell, and therefore the hydraulic jack needs to be fixed to the outer shell.

[0008] Furthermore, if the hydraulic jack rotates around the longitudinal axis of the outer shell relative to the outer shell, when the shock absorber with vehicle height adjustment function is installed on a car, the hose connection points of the hydraulic jack will be scattered, making it difficult to install into the vehicle. Therefore, in conventional shock absorbers with vehicle height adjustment function, it is necessary to provide a stopper to prevent the hydraulic jack from rotating around its axis.

[0009] As described above, conventional shock absorbers with height adjustment functions have the problem that they require the hydraulic jack to be fixed and prevented from rotating, which increases the number of parts and makes the vehicle heavier.

[0010] SUMMARY OF THE PRESENT EMBODIMENTS 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 the weight. [Means for solving the problem]

[0011] In order to solve the above-mentioned problems, the shock absorber with vehicle height adjustment function in the problem-solving means of the present invention is configured to include a cylinder, a housing having a bottom and a cylindrical portion, one end of the cylinder being inserted into the cylindrical portion, an air-liquid separator movably inserted into the cylindrical portion of the housing further toward the bottom than the cylinder and dividing the inside of the housing into an air chamber and a space communicating with the inside of the cylinder, a piston movably inserted into the cylinder and dividing the inside of the cylinder into an extension side chamber and a compression side chamber, a rod movably inserted into the cylinder and connected to the piston, a jack piston movably inserted in the axial direction into a jack chamber formed between the cylinder and the cylindrical portion of the housing in the radial direction, and a suspension spring bearer that supports one end of a suspension spring and is driven by the jack piston.

[0012] In a shock absorber with vehicle height adjustment function configured in this manner, a jack chamber is formed between the cylinder and a housing which contains the gas-liquid separator and which, together with the cylinder, constitutes the pressure vessel of the shock absorber body. Since the jack body is integrally and inseparably attached to the shock absorber body, there is no need to attach a separate hydraulic jack to the outer periphery of the cylinder as in conventional shock absorbers with vehicle height adjustment function.

[0013] The shock absorber with height adjustment function may further include a sub-cylinder that covers the outer periphery of one end of the cylinder and is disposed on the inner periphery of the tubular portion of the housing, and the jack chamber may be formed by the gap between the sub-cylinder and the tubular portion. The shock absorber with height adjustment function configured in this manner can reduce the number of processing steps and costs, and can also eliminate the trouble of having to make many design changes when changing the cross-sectional area of ​​the jack chamber.

[0014] The sub-cylinder in the height-adjustable shock absorber may have a flange on its outer periphery to prevent the jack piston from coming out of the jack chamber, and the flange may have a groove on its outer periphery for engaging a tool. In the height-adjustable shock absorber configured in this manner, the flange can be used not only to prevent the jack piston from coming out, but also to connect the cylinder and the housing to the sub-cylinder. The shock absorber with height adjustable function may also include a valve case fixed to the sub-cylinder and having a passage that communicates between the compression side chamber and the space.

[0015] Furthermore, the suspension spring bearing in the height-adjustable shock absorber may include an annular seat portion that supports one end of the suspension spring, and one or more grooves that connect from the inner periphery to the outer periphery of the surface of the seat portion that faces the end face of the cylindrical portion of the housing. According to the height-adjustable shock absorber configured in this manner, even if the seat portion abuts against the cylindrical portion, the gap between the jack piston and the cylindrical portion communicates with the outside through the groove, so that water, dust, and other particles that have entered the gap can be discharged to the outside through the groove, and the suspension spring bearing prevents dust from being pushed into the jack chamber.

[0016] In addition, the gas-liquid separator in the height-adjustable shock absorber may be a free piston that slides against the inner periphery of the cylindrical portion of the housing, and the inner diameter of the cylindrical portion of the housing within the range in which the free piston moves may be larger than the inner diameter of the cylinder. With this height-adjustable shock absorber configured in this manner, even if a structure is adopted in which the free piston is housed inside the housing connected to the cylinder, the stroke length of the piston relative to the cylinder can be secured while shortening the overall length.

[0017] Furthermore, the housing of the height-adjustable shock absorber may include a connection port for supplying and discharging liquid into the jack chamber, and a bracket that enables attachment to the vehicle. With the height-adjustable shock absorber configured in this manner, the positions of the bracket and the connection port provided in the housing that forms the jack chamber are in a predetermined relationship, so that if the housing is directly attached to the vehicle using the bracket, the connection port can be positioned at an optimal position for attaching the connection pipe, and attachment to the vehicle and connection to a pump installed in the vehicle can also be made easy. Effect of the Invention

[0018] According to the shock absorber with vehicle height adjustment function of the present invention, the number of parts and the weight can be reduced. [Brief description of the drawings]

[0019] [Figure 1] 1 is a diagram showing a shock absorber with a vehicle height adjustment function according to an embodiment; [Diagram 2] 1 is a partially enlarged cross-sectional view of a shock absorber with a vehicle height adjustment function according to an embodiment of the present invention; [Diagram 3] FIG. 13 is a diagram showing a shock absorber with a vehicle height adjustment function according to a modified example of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The present invention will be described below based on the embodiments shown in the drawings. As shown in Fig. 1 and Fig. 2, a shock absorber D with a vehicle height adjustment function in one embodiment includes a cylinder 1, a cylindrical housing 2 into which one end of the cylinder 1 is inserted, a free piston 3 as a gas-liquid separator that is movably inserted into the housing 2 and divides the inside of the housing 2 into an air chamber G and a space S that communicates with the inside of 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 connected to the piston 4, a jack piston 15 that is movably inserted into a jack chamber 6 formed between the cylinder 1 and the housing 2, and a suspension spring bearing 8 that supports one end of a suspension spring 7 and is driven by the jack piston 15.

[0021] Although not shown, shock absorber D with vehicle height adjustment function is installed horizontally between the vehicle body and a link connected to a knuckle supporting the vehicle wheel, and suppresses vibration between the vehicle body and the wheel with a damping force generated during expansion and contraction, and the height of the vehicle body (vehicle height) can be adjusted by moving suspension spring bearing 8 in the axial direction relative to cylinder 1. Note that shock absorber D with vehicle height adjustment function is not limited to automobiles, but may be used in motorcycles and other vehicles, and may be used in a longitudinally installed state relative to the vehicle.

[0022] Each part of the shock absorber D with height adjustment function will be described in detail below. The cylinder 1 is cylindrical and has a screw 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. 1, which is one end. The sub-cylinder 9 has a small diameter portion 9a at its one end, which is the right end in FIG. 1, whose inner diameter is smaller than the inner diameter of the cylinder 1, an inner peripheral flange 9b provided on the inner periphery of the small diameter portion 9a at the right end in FIG. 1, a flange 9c provided on the outer periphery at the left end in FIG. 1, which is the other 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 periphery of the one end side of the cylinder 1 by screwing the screw portion 9d on the inner periphery into the screw portion 1a provided on the outer periphery of the cylinder 1. 1, a step portion of cylinder 1 abuts against the left end of small diameter portion 9a of sub-cylinder 9, and when sub-cylinder 9 is screwed to cylinder 1, an axial load is applied to threaded portion 1a and threaded portion 9d, firmly connecting cylinder 1 and sub-cylinder 9. Flange 9c provided on the outer periphery at the other end of sub-cylinder 9 has a plurality of grooves 9e that are equally spaced in the circumferential direction and enable gripping with a tool (not shown), and an operator can apply a large tightening torque to sub-cylinder 9 against cylinder 1 using a tool to grip flange 9c, making it easy to attach sub-cylinder 9 to cylinder 1.

[0023] The inner periphery of the sub-cylinder 9, on the other end side of the small diameter portion 9a, can be fitted into the outer periphery of the cylinder 1, and the sub-cylinder 9 is attached to the cylinder 1 without any backlash. A seal ring 10 is attached to the inner periphery of the sub-cylinder 9, between the threaded portion 9d and the small diameter portion 9a, and the gap between the sub-cylinder 9 and the cylinder 1 is sealed by the seal ring 10. Note that a seal ring may be attached to the outer periphery of the cylinder 1, on the one end side of the threaded portion 1a, but because the seal ring needs to climb over the threaded portion 9d in the process of inserting the cylinder 1 into the sub-cylinder 9, providing the seal ring on the sub-cylinder 9 side is preferable from the viewpoint of protecting the seal ring.

[0024] In addition, an annular valve case 11 is fitted onto the inner periphery of the small diameter portion 9a of the sub-cylinder 9, and the valve case 11 is fixed to the sub-cylinder 9 by being clamped between an outer periphery nut 12 that is screwed onto the inner periphery of the small diameter portion 9a and an inner periphery flange 9b.

[0025] The housing 2 is cylindrical with a bottom and includes a bottom 20 and a tubular portion 21. The bottom 20 includes a bracket 20a at an end thereof that can be connected to a vehicle body of a vehicle. The tubular portion 21 includes a jack tubular 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 its inner periphery, a reservoir tubular portion 21b that is provided closer to the bottom 20 than the jack tubular portion 21a and has an inner diameter larger 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 that is provided between the jack tubular portion 21a and the reservoir tubular portion 21b and connects the jack tubular portion 21a and the reservoir tubular portion 21b.

[0026] A screw portion 21d is provided on the inner circumference of the intermediate cylinder portion 21c, and the housing 2 is connected to the cylinder 1 via the sub-cylinder 9 by screwing the screw portion 21d into the screw portion 9e provided on the outer circumference of the small diameter portion 9a of the sub-cylinder 9 inserted into the housing 2 from the jack cylinder portion 21a side of the housing 2. The inner diameter of the right end side of the intermediate cylinder portion 21c in FIG. 1, which is one end side of the intermediate cylinder portion 21c, is reduced midway, and a step portion 21e that abuts against one end of the sub-cylinder 9 is provided on the inner circumference of the intermediate cylinder portion 21c. Therefore, when the housing 2 is screwed to the sub-cylinder 9, a load is applied in the axial direction to the screw portion 9e and the screw portion 21d, and the sub-cylinder 9 and the housing 2 can be firmly connected. A recess 21k is provided on the outer circumference of the intermediate cylinder portion 21c for the purpose of reducing the weight of the shock absorber D with a height adjustment function, but the recess 21k may not be provided.

[0027] When the housing 2 is connected to the cylinder 1 in this manner, one end of the cylinder 1 is inserted halfway into the tubular portion 21 of the housing 2, and the jack tubular portion 21a covers the right end side in FIG. 1, which is the one end side of the cylinder 1, and the outer periphery of the sub-cylinder 9, and the jack chamber 6 is formed by the annular gap between the jack tubular portion 21a and the sub-cylinder 9. When the housing 2 is connected to the cylinder 1, the inside of the reservoir tubular portion 21b is connected to the inside of the cylinder 1. A free piston 3 serving as a gas-liquid separator is inserted into the reservoir tubular portion 21b so as to be movable in the axial direction of the reservoir tubular portion 21b. The free piston 3 slides against the inner periphery of the reservoir tubular portion 21b, and divides the reservoir tubular portion 21b into an air chamber G filled with gas and a space S connected to the inside of the cylinder 1 and filled with liquid. The reservoir R is composed of the space S and the air chamber G. The gas-liquid separator may be anything that can separate the air chamber G filled with gas from the space S filled with liquid within the housing 2, and may be a bellows, a diaphragm, a bladder, etc. in addition to the free piston 3.

[0028] A gas is sealed in the air chamber G, which pressurizes the inside of the cylinder 1 through the space S. The gas sealed in the air chamber G is preferably an inert gas such as nitrogen, but may be air or other gases.

[0029] In this manner, in the shock absorber D with vehicle height adjustment function of this embodiment, the cylinder 1 and the housing 2 that accommodates the free piston 3 as a gas-liquid separator form a pressure vessel for functioning as a shock absorber, and together with the piston 4 and rod 5, constitute the shock absorber main body.

[0030] In addition, a seal ring 14 that fits tightly against the outer periphery of the sub-cylinder 9 is attached to the inner periphery of the intermediate cylindrical portion 21c, and the gap between the housing 2 and the sub-cylinder 9 is sealed by the seal ring 14, thereby cutting off communication between the jack chamber 6 and the reservoir R.

[0031] The intermediate cylindrical portion 21c of the housing 2 is provided with a liquid inlet 21f that opens from a portion radially opposed to the space S, penetrates the wall thickness, and reaches the outer periphery. The liquid inlet 21f is used to inject liquid into the cylinder 1 and the space S, and is then closed by a plug 22 screwed into the intermediate cylindrical portion 21c. As shown in Fig. 2, the jack cylindrical portion 21a is provided, at one end side (the right end side in Fig. 2), with a connection port 21g that penetrates the inner and outer periphery and leads to the jack chamber 6, and an air vent hole 21h that is provided at a position close to the connection port 21g in the circumferential direction and is closed by a plug (not shown).

[0032] The connection port 21g is a port for connecting the connection pipe 13 extending from the pump P installed in the vehicle. Although not shown, the connection port 21g has a female screw formed on its inner periphery, and a connecting part 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 from a tank T installed in the vehicle to the jack chamber 6, and can also discharge liquid from the jack chamber 6 to the tank T. Therefore, by driving the pump P, it is possible to supply liquid to the jack chamber 6 and discharge liquid from the jack chamber 6 through the connection port 21g and the connection pipe 13.

[0033] A cylindrical jack piston 15, which is in sliding contact with the outer periphery of the sub-cylinder 9 and the inner periphery of the jack barrel portion 21a, is inserted between the sub-cylinder 9 and the jack barrel portion 21a in the housing 2, and the left end opening of the jack chamber 6 in FIG. 1 is closed by the jack piston 15. As shown in FIG. 2, the jack piston 15 has annular grooves 15a and 15b provided along the circumferential direction at two locations on the inner periphery, and is integrally provided with an annular suspension spring bearing 8 at the left end in FIG. 1. An annular dust seal 16, which is in sliding contact with the outer periphery of the sub-cylinder 9, is accommodated in the annular groove 15a on the atmosphere side of the jack piston 15, and an annular U-packing 17, which is in sliding contact with the outer periphery of the sub-cylinder 9, is accommodated in the annular groove 15b on the jack chamber side, which is the side opposite to the atmosphere, of the jack piston 15.

[0034] 2, annular grooves 21i, 21j are provided in two locations along the circumferential direction on the inner periphery of the jack barrel portion 21a in the housing 2. An annular dust seal 18 that slides against the outer periphery of the jack piston 15 is accommodated in the annular groove 21i on the atmosphere side of the jack barrel portion 21a, and an annular U-packing 19 that slides against the outer periphery of the jack piston 15 is accommodated in the annular groove 21j on the jack chamber side, which is the side opposite to the atmosphere, of the jack barrel portion 21a.

[0035] Therefore, the gap between the sub-cylinder 9 and the jack piston 15 is sealed by the U-packing 17, and the gap between the housing 2 and the jack piston 15 is sealed by the U-packing 19, preventing liquid from leaking from the jack chamber 6. Furthermore, the dust seal 16 and the dust seal 18 prevent water, dust, and the like from entering the jack chamber 6. Note that, in the shock absorber D with height adjustment function of this embodiment, the jack chamber 6 is annular and the jack piston 15 is also cylindrical, but the cross-sectional shape of the jack chamber 6 does not have to be annular, and the cross-sectional shape of the jack piston 15 does not have to be annular either, as long as it matches the cross-sectional shape of the jack chamber 6 and the jack piston 15 can close the opening of the jack chamber 6.

[0036] The suspension spring bearing 8 is integrated with the left end of the jack piston 15 in Fig. 1, and includes an annular seat portion 8a that supports the right end of the suspension spring 7 in Fig. 1, and a guide tube 8b that is provided on the inner periphery of the seat portion 8a, fits into the inner periphery of the suspension spring 7, and has one end connected to the jack piston 15. Although the suspension spring bearing 8 is configured as a single component together with the jack piston 15, it may be a separate component that can be separated from the jack piston 15.

[0037] The guide tube 8b has an inner diameter larger than the outer diameter of the flange 9c of the sub-cylinder 9, and allows the flange 9c to pass through. 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. When the jack piston 15 is fully removed from the jack chamber 6, it abuts against the flange 9c and is restricted from further removing from the jack chamber 6. In this way, the flange 9c not only allows a tool to be held 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. When the jack piston 15 is removed from the jack chamber 6, water, dust, and other particles adhering to the outer periphery of the sub-cylinder 9 are scraped off by the dust seal 16 on the inner periphery of the jack piston 15. Even if the flange 9c abuts against the jack piston 15, the scraped-off dust is discharged to the outside through the groove 9e because the gap between the sub-cylinder 9 and the jack piston 15 on the atmospheric side of the dust seal 16 communicates with the outside through the groove 9e. Therefore, even if the jack piston 15 repeatedly reciprocates in the axial direction and abuts against 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.

[0038] When the jack piston 15 penetrates into the jack chamber 6 to the maximum extent, the seat portion 8a comes into contact with the left end of the jack barrel portion 21a of the housing 2 in FIG. 1 to restrict the jack piston 15 from penetrating further into the jack chamber 6. A plurality of grooves 8c extending from the inner periphery to the outer periphery are provided radially at equal intervals in the circumferential direction on the surface of the seat portion 8a facing the end face (the left end face in FIG. 1) of the jack barrel portion 21a. When the jack piston 15 penetrates into the jack chamber 6, water, dust, and other particles adhering to the outer periphery of the jack piston 15 are scraped off by the dust seal 18 on the inner periphery of the jack barrel portion 21a. Even if the seat portion 8a abuts against the jack barrel portion 21a, the scraped-off dust is discharged to the outside through the groove 8c because the gap between the jack piston 15 and the dust seal 18 of the jack barrel portion 21a, which is closer to the atmosphere, is open to the outside through the groove 8c. Therefore, even if the suspension spring bearing 8 repeatedly reciprocates in the axial direction and abuts against the jack barrel portion 21a, the dust scraped off by the dust seal 18 is accumulated in the gap and is not pushed into the jack chamber 6 by the suspension spring bearing 8.

[0039] 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 presses the jack piston 15 against the biasing force of the suspension spring 7, causing it to move in a direction retracting from the jack chamber 6. With the movement of the jack piston 15, the suspension spring bearing 8 integrated with the jack piston 15 also moves leftward in FIG. 1. Conversely, when the pump P is driven to discharge liquid from the jack chamber 6 into the tank T, the jack piston 15 moves rightward in FIG. 1 in a direction in which it enters the jack chamber 6 due to the biasing force of the suspension spring 7. Thus, in the shock absorber D with vehicle height adjustment function of this embodiment, the suspension spring bearing 8 can move in the axial direction relative to the cylinder 1 by supplying and discharging liquid into the jack chamber 6 using the pump P.

[0040] As described above, in the shock absorber D with vehicle height adjustment function of this embodiment, the hydraulic jack that drives the suspension spring bearing 8 is composed of the jack chamber 6 formed between the cylinder 1 and the housing 2, a jack body consisting of a jack piston 15 that moves in and out of the jack chamber 6, a pump P as a supply / discharge means for supplying and discharging liquid into the jack chamber 6, and a tank T for storing liquid. Since the jack chamber 6 is thus formed by the housing 2 that constitutes a part of the pressure vessel of the shock absorber body, in the shock absorber D with vehicle height adjustment function of this embodiment, the jack body is provided integrally and inseparably with the shock absorber body.

[0041] As described above, the piston 4 is inserted into the cylinder 1 so as to be movable in the axial direction relative to the cylinder 1. The piston 4 divides the inside of the cylinder 1 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. 1. The expansion-side chamber R1 and the compression-side chamber R2 are filled with a liquid, specifically, hydraulic oil, for example. Note that, as the hydraulic liquid, liquids such as water and aqueous solutions may be used in addition to hydraulic oil.

[0042] The piston 4 is annular, and is attached to the outer periphery of the rod 5, which is inserted into the cylinder 1 so as to be axially movable, together with an annular extension side damping valve 26 and an annular compression side damping valve 27, and is fixed to the rod 5 by a piston nut 28.

[0043] The piston 4 also has an expansion-side passage 4a and a compression-side passage 4b ​​that communicate the expansion-side chamber R1 and the compression-side chamber R2. In the shock absorber D with vehicle height adjustment function of this embodiment, the expansion-side damping valve 26 is a leaf valve whose inner periphery is fixed to the rod 5 and whose outer periphery is allowed to bend, and is stacked on the compression-side chamber side of the piston 4 to open and close the expansion-side passage 4a. Specifically, when the expansion-side damping valve 26 is deflected by the pressure of the expansion-side chamber R1, it opens the expansion-side passage 4a to allow the flow of liquid from the expansion-side chamber R1 to the compression-side chamber R2 while providing resistance to the flow, and closes the expansion-side passage 4a to prevent the flow of liquid from the compression-side chamber R2 to the expansion-side chamber R1. In the shock absorber D with vehicle height adjustment function of this embodiment, 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 bend, and is stacked on the expansion-side chamber side of the piston 4 to open and close the compression-side passage 4b. Specifically, when the compression side damping valve 27 is deflected by 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 to the expansion side chamber R1 while providing resistance to the flow, and closes the compression side passage 4b ​​to prevent the flow of liquid from the expansion side chamber R1 to the compression side chamber R2.

[0044] 1, which is the other end of the cylinder 1, is attached with an annular rod guide 23, and the other end of the rod 5 protrudes outside the cylinder 1 through the inner periphery of the rod guide 23. The rod guide 23 has a cylindrical bush 23a that slides against the outer periphery of the rod 5, and guides the axial movement of the rod 5 relative to the cylinder 1. An annular seal member 24 is laminated on the atmospheric side of the rod guide 23, and is fixed to the cylinder 1 together with the rod guide 23 by a head cap 25 that is screwed onto the outer periphery of the left end in FIG. 1, which is the other end of the cylinder 1. The seal member 24 seals the outer periphery of the rod 5 to prevent liquid from leaking from inside the cylinder 1.

[0045] Furthermore, a bracket 5a is provided at the tip of the rod 5, which can connect the rod 5 to a link connected to a knuckle that holds the wheel of the vehicle, and a rod-side suspension spring bearing 5b is provided to support the other end of the suspension spring 7. The suspension spring 7 is interposed in a compressed state between the rod-side suspension spring bearing 5b and a seat portion 8a of the suspension spring bearing 8, and biases the rod 5 in a direction to move the rod 5 out of the cylinder 1, that is, in a direction to extend the shock absorber D with vehicle height adjustment function. The suspension spring bearing 8 is provided with a guide tube 8b that fits into the inner periphery of the suspension spring 7, so that the suspension spring 7 is prevented from being misaligned in the radial direction, and the suspension spring 7 is prevented from interfering with the cylinder 1.

[0046] 2, the valve case 11 fixed to the sub-cylinder 9 is annular, and includes a discharge passage 11a and a suction passage 11b that communicate between the compression side chamber R2 and the space S in the reservoir tubular portion 21b of the housing 2. A shaft portion of a guide rod 29 having a shaft portion with a threaded portion at its tip and a flange provided at one end of the shaft portion is inserted into the inner periphery of the valve case 11. An annular base valve 31, the valve case 11, and an annular check valve 30 are assembled in this order from the right side in FIG. 2 to the outer periphery of the shaft portion of the guide rod 29, and the base valve 31, the valve case 11, and the check valve 30 are fixed to the guide rod 29 by a nut 32.

[0047] The base valve 31 is fixed at its inner periphery to the guide rod 29 and is allowed to bend on its outer periphery, and is stacked on the reservoir side of the valve case 11 to open and close the discharge passage 11a. Specifically, when the base valve 31 is bent by the pressure of the compression side chamber R2, it opens the discharge passage 11a to allow the flow of liquid from the compression side chamber R2 to the space S in the reservoir R while providing resistance to the flow, and closes the discharge passage 11a to prevent the flow of liquid from the space S to the compression side chamber R2. The check valve 30 is fixed at its inner periphery to the guide rod 29 and is allowed to bend on its outer periphery, and is stacked on the compression side chamber side of the valve case 11 to open and close the suction passage 11b. Specifically, the check valve 30 bends under the pressure of the space S, opening the suction passage 11b and allowing the flow of liquid from the space S to the pressure side chamber R2 without much resistance, and blocks the suction passage 11b to prevent the flow of liquid from the pressure side chamber R2 to the space S.

[0048] The shock absorber D with height adjustment function of this embodiment is configured as described above, and the operation of the shock absorber D with height adjustment function will be described below. First, the operation when the shock absorber D with height adjustment function operates to expand and contract will be described. When the shock absorber D with height adjustment function operates to expand and the rod 5 and the piston 4 move to the left in FIG. 1 relative to the cylinder 1, the extension side chamber R1 is contracted and the compression side chamber R2 is expanded as the piston 4 moves. The liquid in the contracted extension side chamber R1 passes through the extension side passage 4a of the piston 4, deflecting the extension side damping valve 26, and moves to the expanded compression side chamber R2. Since the extension side damping valve 26 provides resistance to the flow of this liquid passing through the extension side passage 4a, the pressure in the extension side chamber R1 rises and becomes higher than the pressure in the compression side chamber R2.

[0049] During the extension operation of the shock absorber D with height adjustment function, the rod 5 retreats from the cylinder 1, causing a shortage of liquid in the cylinder 1. However, the check valve 30 opens and the shortage liquid is supplied from the reservoir R to the compression side chamber R2 through the suction 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 to the left in FIG. 1 inside the housing 2, expanding the air chamber G. In this way, the volume of the rod 5 retreating from the cylinder 1 due to the extension operation of the shock absorber D with height adjustment function is compensated by the reservoir R. As a result, the pressure in the compression side chamber R2 becomes almost equal to that of the reservoir R, and 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 height adjustment function generates a damping force that hinders the extension operation according to the difference between the pressure in the expansion side chamber R1 and the pressure in the compression side chamber R2.

[0050] Next, the operation of the shock absorber D with height adjustment function when it is contracted will be described. When the shock absorber D with height adjustment function is contracted and the rod 5 and the piston 4 move to the right in FIG. 1 relative to the cylinder 1, the compression side chamber R2 is contracted and the expansion side chamber R1 is expanded in accordance with the movement of the piston 4. The liquid in the contracted compression side chamber R2 passes through the compression side passage 4b ​​of the piston 4, deflecting the compression side damping valve 27, and moves to the expanded expansion side chamber R1.

[0051] In addition, when the shock absorber D with height adjustment function is contracted, the rod 5 enters the cylinder 1, so that the liquid in the cylinder 1 becomes excessive. And However, the base valve 31 opens and the excess liquid is discharged from the compression side chamber R2 to the reservoir R through the discharge passage 11a. The compression side damping valve 27 and the base valve 31 provide resistance to the flow of the liquid passing through the compression side passage 4b ​​and the discharge passage 11a, so the pressure in the compression side chamber R2 rises and becomes higher than the pressure in the expansion side chamber R1. In addition, the liquid equivalent to the volume of the rod 5 entering the cylinder 1 from the compression side chamber R2 moves to the space S, so that the free piston 3 moves to the right in FIG. 1 inside the housing 2, thereby reducing the air chamber G. In this way, the volume of the rod 5 entering the cylinder 1 due to the contraction operation of the shock absorber D with height adjustment function is compensated for by the reservoir R.

[0052] 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. of Depending on the difference, a damping force is generated that hinders the contraction operation.

[0053] Instead of the compression side damping valve 27, a check valve that does not provide 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 provide much resistance, the pressures in both the expansion side chamber R1 and the compression side chamber R2 in the cylinder 1 are increased to approximately equal pressures by the base valve 31 during the contraction operation of the height adjustable shock absorber D. However, since the pressure receiving area of ​​the piston 4 on the compression side chamber side is larger than the pressure receiving area of ​​the expansion side chamber side, the height adjustable shock absorber D generates a damping force that prevents contraction.

[0054] In this 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 may be eliminated. In this case, the shock absorber D with height adjustment function has the same configuration as a so-called mono-tube shock absorber, so that during extension, the extension side damping valve 26 generates a damping force that prevents the extension operation, and during contraction, the compression side damping valve 27 generates a damping force that prevents the contraction operation. Note that, although the extension side damping valve 26, the compression side damping valve 27, and the base valve 31 are all leaf valves, they may be valves of other structures that can generate a damping force in the shock absorber D with height adjustment function, such as poppet valves and needle valves.

[0055] Next, the operation of the shock absorber D with vehicle height adjustment function when adjusting the vehicle height will be described. When raising the vehicle height with the shock absorber D with vehicle height adjustment function, the pump P is driven to supply liquid into the jack chamber 6. When liquid is supplied from the pump P to the jack chamber 6, the jack piston 15 moves in a direction retracting from the jack chamber 6, so that the suspension spring bearing 8 moves leftward relative to the cylinder 1 in FIG. 1, displacing the support position of the suspension spring 7. The suspension spring 7 is compressed with the shock absorber D with vehicle height adjustment function interposed between the vehicle body and the wheels, and exerts a resilient force equivalent to supporting the wheel load received by the wheels from the vehicle body, so that the compression length does not change even if the suspension spring bearing 8 moves leftward relative to the cylinder 1 in FIG. 1. 1 relative to the cylinder 1, the rod 5 is displaced in a direction retracting from the cylinder 1 by approximately the same amount of displacement as the suspension spring bearing 8, raising the vehicle body by an amount equal to the displacement of the rod 5 multiplied by the lever ratio of the link. In this way, by supplying liquid from the pump P to the jack chamber 6, the suspension spring bearing 8 is displaced according to the amount of liquid supplied into the jack chamber 6, so that the shock absorber D with vehicle height adjustment function can raise the vehicle height.

[0056] On the other hand, when the vehicle height is lowered by the shock absorber D with vehicle height adjustment function, the pump P is driven to discharge the liquid from 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 bearing 8 moves rightward relative to the cylinder 1 in FIG. 1, displacing the support position of the suspension spring 7. When the suspension spring bearing 8 moves rightward relative to the cylinder 1 in FIG. 1, the rod 5 enters the cylinder 1 with a displacement amount substantially equal to the displacement amount of the suspension spring bearing 8, and the vehicle body is lowered by a value obtained by multiplying the displacement amount of the rod 5 by the lever ratio of the link. In this way, when the pump P discharges the liquid from the jack chamber 6, the suspension spring bearing 8 is displaced according to the amount of liquid discharged from the jack chamber 6, so that the shock absorber D with vehicle height adjustment function can lower the vehicle height. The suspension spring bearing 8 always receives a load from the suspension spring 7 equal to the vehicle body weight supported by the suspension spring 7, and biases the jack piston 15 in a direction to contract the jack chamber 6. Therefore, a passage that bypasses the pump P and communicates with the tank T for storing liquid, and an on-off valve that opens and closes the passage may be provided, and the vehicle height may be lowered by opening the on-off valve instead of driving the pump P to discharge the liquid from the jack chamber 6 to the tank T. Even if the shock absorber D with vehicle height adjustment function is configured in this way, if 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 liquid can be automatically discharged from the jack chamber 6 to the tank T, so that the vehicle height can be lowered.

[0057] The shock absorber D with vehicle height adjustment function of this embodiment is configured to include a cylinder 1, a housing 2 having a bottom 20 and a cylindrical portion 21, one end of the cylinder 1 being inserted into the cylindrical portion 21, a free piston (gas-liquid separator) 3 movably inserted into the cylindrical portion 21 of the housing 2 toward the bottom side of the cylinder 1 and dividing 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 movably inserted into the cylinder 1 and dividing the inside of the cylinder 1 into an extension side chamber R1 and a compression side chamber R2, a rod 5 movably inserted into the cylinder 1 and connected to the piston 4, a jack piston 15 movably inserted in the axial direction into a jack chamber 6 formed between the cylinder 1 and the cylindrical portion 21 of the housing 2 in the radial direction, and a suspension spring bearer 8 which supports one end of a suspension spring 7 and is driven by the jack piston 15.

[0058] In the shock absorber D with vehicle height adjustment function configured as described above, a jack chamber 6 is formed between the cylinder 1 and the housing 2 that contains the free piston (gas-liquid separator) 3 and constitutes the pressure vessel of the shock absorber body together with the cylinder 1, and the jack body is provided integrally and inseparably with the shock absorber body, so there is no need to attach a separate hydraulic jack to the outer periphery of the cylinder as in the conventional shock absorber with vehicle height adjustment function. Therefore, according to the shock absorber D with vehicle height adjustment function of this embodiment, since the jack body is provided integrally and inseparably with the shock absorber body, there is no need to fix and stop the hydraulic jack to the shock absorber body. As described above, according to the shock absorber D with vehicle height adjustment function of this embodiment, the number of parts can be reduced and the weight can be reduced by the amount that it is not necessary to fix and stop the hydraulic jack compared to the conventional shock absorber with vehicle height adjustment function.

[0059] In addition, since the jack chamber 6 only needs to be formed between the cylinder 1 and the housing 2, it may be formed in the gap between the sub-cylinder 9 and the housing 2 as in the shock absorber D with vehicle height adjustment function of this embodiment. In the shock absorber D with vehicle height adjustment function of this embodiment, the jack chamber 6 is formed in the gap between the sub-cylinder 9 and the housing 2. However, as shown in FIG. 3, the sub-cylinder 9 may be omitted and the jack chamber 6 may be formed in the gap between the cylinder 1 and the tubular portion 21 of the housing 2, and the jack piston 15 may be inserted into the jack chamber 6 by sliding it against the outer periphery of the cylinder 1 and the inner periphery of the jack tubular portion 21a of the housing 2. To attach the valve case 11 to the cylinder 1, a small diameter portion 1b and an inner periphery flange 1c may be provided at the right end of the cylinder 1 in FIG. 3, which is one end of the cylinder 1, in the same manner as the small diameter portion 9a and the inner periphery flange 9b provided in the sub-cylinder 9, and the valve case 11 may be sandwiched between the inner periphery flange 1c and the outer periphery nut 33. If the valve case 11 is not provided, there is no need to provide the small diameter portion 1b and the inner peripheral flange 1c. If the sub-cylinder 9 is eliminated, a threaded portion 1d may be provided on the outer periphery of the cylinder 1, and an annular stopper 34 for preventing the jack piston 15 from falling out of the jack chamber 6 may be attached to the threaded portion 1d. The stopper 34 may be a C-pin, and in that case, an annular groove for mounting the C-pin may be provided on the outer periphery of the cylinder 1.

[0060] In this way, the jack chamber 6 may be formed in the gap between the cylinder 1 and the housing 2, but the shock absorber D with height adjustment function of this embodiment is provided with a sub-cylinder 9 that covers the outer periphery of one end of the cylinder 1 and is disposed on the inner periphery of the tubular portion 21 of the housing 2, and the jack chamber 6 is formed in the gap between the sub-cylinder 9 and the tubular portion 21. Here, if 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 slides against the inner periphery of the cylinder 1, and the jack piston 15 slides against the outer periphery of the cylinder 1. butIn this case, the piston 4 and the jack piston 15 have different displacement amounts and speeds relative to the cylinder 1, so different surface treatments must be applied to the piston sliding surface on the inner circumference of the cylinder 1 and the jack piston sliding surface on the outer circumference. Different surface treatments can be applied to the inner circumference and the outer circumference of the cylinder 1, but this increases the number of processing steps and costs. Therefore, the shock absorber D with height adjustment function using the sub-cylinder 9 can reduce the number of processing steps and costs. In addition, the shock absorber D with height adjustment function using the sub-cylinder 9 can easily change the cross-sectional area of ​​the jack chamber 6 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, which forces many design changes, but the shock absorber D with height adjustment function using the sub-cylinder 9 does not have such trouble.

[0061] In the shock absorber D with vehicle height adjustment function of this embodiment, the sub-cylinder 9 has a flange 9c on its outer periphery to prevent the jack piston 15 from coming out of the jack chamber 6, and the flange 9c has a groove 9e on its outer periphery with which a tool can be engaged. According to the shock absorber D with vehicle height adjustment function configured in this manner, the flange 9c can be used not only to prevent the jack piston 15 from coming out, but also to connect the cylinder 1 and the housing 2 to the sub-cylinder 9.

[0062] Furthermore, in the shock absorber D with vehicle height adjustment function of this embodiment, the suspension spring bearing 8 is provided with an annular seat portion 8a that supports one end of the suspension spring 7, and one or more grooves 8c that connect from the inner periphery to the outer periphery of the surface of the seat portion 8a that faces the end face of the tubular portion 21 of the housing 2. According to the shock absorber D with vehicle height adjustment function configured in this manner, even if the seat portion 8a abuts against the tubular portion 21, the gap between the jack piston 15 and the tubular portion 21 communicates with the outside through the groove 8c, so that water, dust, and other dust that has entered the gap can be discharged to the outside through the groove 8c, and the suspension spring bearing 8 prevents the dust from being pushed into the jack chamber 6. In the shock absorber D with vehicle height adjustment function of this embodiment, the grooves 8c provided in the seat portion 8a are provided radially at equal intervals in the circumferential direction of the seat portion 8a, but can be eliminated if there is no risk of the suspension spring bearing 8 pushing dust into the jack chamber 6. Furthermore, as long as the grooves 8c are formed from the inner periphery to the outer periphery of the seat portion 8a of the suspension spring bearing 8, the number, locations and shapes of the grooves 8c can be freely modified.

[0063] In the shock absorber D with height adjustment function of this embodiment, the gas-liquid separator is the free piston 3 that slides against the inner circumference of the tubular portion 21 of the housing 2, and the inner diameter of the moving range of the free piston 3 of the tubular portion 21 of the housing 2 (the inner diameter of the reservoir tubular portion 21b) is larger than the inner diameter of the cylinder 1. In the shock absorber D with height adjustment function, when the piston 4 is displaced relative to the cylinder 1, the rod 5 moves in and out of the cylinder 1, so that the free piston 3 also displaces relative to the housing 2, changing the volume of the air chamber G. According to the shock absorber D with height adjustment function in which the inner diameter of the moving range of the free piston 3 of the tubular portion 21 of the housing 2 (the inner diameter of the reservoir tubular portion 21b) is larger than the inner diameter of the cylinder 1, the outer diameter of the free piston 3 can be made larger than the outer diameter of the piston 4, so that the stroke amount of the free piston 3 can be made smaller than the stroke amount of the piston 4 relative to the cylinder 1, and the tubular portion 21 of the housing 2 can be shortened accordingly. Therefore, according to the shock absorber D with vehicle height adjustment function configured in this manner, even if a structure is adopted in which the free piston 3 is accommodated inside the housing 2 connected to the cylinder 1, the stroke length of the piston 4 relative to the cylinder 1 can be secured while the overall length is shortened.

[0064] Furthermore, in the shock absorber D with height adjustment function of this embodiment, the housing 2 is provided with a connection port 21g for supplying and discharging liquid into the jack chamber 6, and a bracket 20a that allows the shock absorber D to be attached to a vehicle. According to the shock absorber D with height adjustment function configured in this manner, the positions of the bracket 20a and the connection port 21g provided in the housing 2 that forms the jack chamber 6 are in a predetermined relationship, so that if the housing 2 is directly attached to the vehicle using the bracket 20a, the connection port 21g can be positioned at an optimal position for attaching the connection pipe 13. Therefore, according to the shock absorber D with height adjustment function, it is also easy to attach the shock absorber D to the vehicle and to connect the shock absorber D to the pump P installed in the vehicle. Since the shock absorber D with height adjustment function of this embodiment is used in a horizontal position relative to the vehicle, it is preferable that the air vent hole 21h is arranged in the housing 2 so that it faces upward when the housing 2 is attached to the vehicle using the bracket 20a. Furthermore, the connection port 21g may be located in a position where an operator can easily connect the connection pipe 13, which is connected to the pump P, to the connection port 21g when the shock absorber D with vehicle height adjustment function is attached to the vehicle. When the shock absorber D with vehicle height adjustment function is installed vertically on the vehicle, the positional relationship between the bracket 20a and the connection port 21g may be set so that the connection port 21g is located in a position where an operator can easily connect the connection pipe 13 to the connection port 21g when the housing 2 is attached to the vehicle using the bracket 20a.

[0065] In addition, according to the shock absorber D with vehicle height adjustment function of this embodiment, the connection port 21g and the air vent hole 21h face upward, so that the air in the hydraulic jack can be easily vented by driving the pump P when the shock absorber D is attached to the vehicle.

[0066] Although the preferred embodiment of the present invention has been described in detail above, modifications, variations and changes can be made without departing from the scope of the appended claims. [Explanation of symbols]

[0067] Reference Signs List 1 cylinder, 2 housing, 3 free piston (gas-liquid separator), 4 piston, 5 rod, 6 jack chamber, 7 suspension spring, 8 suspension spring holder, 8a seat portion, 8c groove, 9 sub-cylinder, 9c flange, 9e groove, 15 jack piston, 20 bottom portion, 20a bracket, 21 tube portion, 21g connection port, D shock absorber with vehicle height adjustment function, G air chamber, S space, R1 extension side chamber, R2 compression side chamber

Claims

1. A cylinder; a housing having a bottom and a cylindrical portion, one end of the cylinder being inserted into the cylindrical portion; a gas-liquid separator that is movably inserted into the cylindrical portion of the housing toward the bottom side of the cylinder and divides the inside of the housing into an air chamber and a space that communicates with the inside of the cylinder; a piston movably inserted into the cylinder to divide 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 axially movably into a jack chamber formed between the cylinder and a cylindrical portion of the housing in a radial direction; and a suspension spring bearing that supports one end of the suspension spring and is driven by the jack piston. A shock absorber with a vehicle height adjustment function.

2. a sub-cylinder that covers an outer periphery of the one end of the cylinder and is disposed on an inner periphery of the cylindrical portion of the housing, The jack chamber is formed by a gap between the sub-cylinder and the cylindrical portion.

2. The shock absorber with vehicle height adjustment function according to claim 1.

3. the sub-cylinder has a flange on its outer periphery for preventing the jack piston from coming out of the jack chamber, The flange has a groove on its outer periphery that allows a tool to be engaged therewith.

3. The shock absorber with vehicle height adjustment function according to claim 2.

4. A valve case is provided which is fixed to the sub-cylinder and has a passageway which communicates between the compression side chamber and the space.

3. The shock absorber with vehicle height adjustment function according to claim 2.

5. The suspension spring bearing has an annular seat portion that supports one end of the suspension spring, and one or more grooves extending from an inner periphery to an outer periphery of a surface of the seat portion that faces an end face of the cylindrical portion of the housing.

5. The shock absorber with vehicle height adjustment function according to claim 1.

6. The gas-liquid separator is a free piston that is in sliding contact with an inner periphery of the cylindrical portion of the housing, The inner diameter of the cylindrical portion of the housing within the range in which the free piston moves is larger than the inner diameter of the cylinder.

6. The shock absorber with vehicle height adjustment function according to claim 1,

7. The housing includes: A connection port for supplying and discharging liquid into and from the jack chamber; and a bracket that enables attachment to a vehicle.

7. The shock absorber with vehicle height adjustment function according to claim 1,

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