SHOCK ABSORBERS EQUIPPED WITH VEHICLE HEIGHT ADJUSTMENT

Abstract

A shock absorber (SA; SA1; SA2; SA3) equipped with vehicle height adjustment according to the present invention comprises: a shock absorber body (D) containing a cylinder (1), a piston (2) inserted into the cylinder (1) such that it is movable in an axial direction and divides the interior of the cylinder (1) into an expansion-side chamber (R1) and a compression-side chamber (R2) filled with a fluid, a piston rod (3) inserted into the expansion-side chamber (R1), movable in the axial direction relative to the cylinder (1) and connected to the piston (2), and an outer tube (5) surrounding the cylinder (1); a separating element (30;301), that the interior of the outer tube (5) is divided into a container (T) and a reservoir (R), the container (T) storing fluid, the reservoir (R) is connected to the compression-side chamber (R2) to compensate for a volume of the piston rod (3) entering and exiting the interior of the cylinder (1); a pump (31) provided at the separating element (30; 301) which supplies and discharges the fluid through the reservoir (R) into the interior of the cylinder (1); and a damping force adjusting valve (18) provided at the separating element (30; 301) configured to adjust a damping force during expansion and compression of the shock absorber body (D).

Description

Technical field

[0001] The present invention relates to a shock absorber equipped with vehicle height adjustment. Background of the invention

[0002] A conventional shock absorber equipped with vehicle height adjustment, for example, contains a cylinder, a piston that is movably inserted into the cylinder and divides the interior of the cylinder into an expansion-side chamber and a compression-side chamber, a piston rod connected to the piston, a high-pressure chamber that communicates with the interior of the cylinder, a low-pressure chamber that stores hydraulic oil, and a pump that supplies the hydraulic oil from the low-pressure chamber to the high-pressure chamber, and is connected between a vehicle body and a wheel in a vehicle.

[0003] In the shock absorber with vehicle height adjustment designed in this way, for example as disclosed in JP2000-127734 A, by driving a pump to supply hydraulic oil to a high-pressure chamber to pressurize the interior of the cylinder, a force is allowed to increase to push the piston rod out of the interior of the cylinder and to raise the vehicle height.

[0004] On the other hand, a shock absorber that can adjust a damping force and improve the ride quality in a vehicle, for example in JP2015-137676 A, was proposed in which a tube is provided between the cylinder and an outer tube surrounding the cylinder, a damping force adjustment passage is formed between the cylinder and the tube, through which the expansion-side chamber and a reservoir are connected, a bushing is provided which projects outwards from an outer circumference of a lower end of the outer tube and has an interior connected to the interior of the outer tube, and a solenoid valve is installed in a center of the damping force adjustment passage and is received in the bushing.In the shock absorber designed in this way, the damping force can be changed by opposing the hydraulic oil directed from the solenoid valve into the reservoir and by adjusting the resistance opposite to the hydraulic oil through the solenoid valve during expansion and contraction. Patent literature Patent Literature 1: JP 2000-127734 A Patent Literature 2: JP 2015-137676 A Description of the invention: Technical problem

[0005] In a shock absorber with height adjustment, as described above, the internal pressure in the cylinder fluctuates during height adjustment, and the damping force generated during expansion and contraction also fluctuates. However, if the damping force can be adjusted, the vehicle's ride quality can be maintained favorably even when the ride height is changed.

[0006] Therefore, by applying the damping force adjustment passage and the solenoid valve of the shock absorber disclosed in JP2015-137676 A to the shock absorber with vehicle height adjustment disclosed in JP2000-127734 A, it is possible to realize a shock absorber with vehicle height adjustment that is able to advantageously maintain the driving quality in the vehicle even when the vehicle height is adjusted.

[0007] However, the shock absorber equipped with vehicle height adjustment contains a pump with a drive and a hydraulic circuit for exchanging hydraulic oil between the low-pressure chamber and the high-pressure chamber when the pump is driven to perform the vehicle height adjustment. In addition to this configuration, if the damping force adjustment passage and the solenoid valve are installed, the pump and solenoid valve are located separately outside the cylinder, increasing the overall size and making installation difficult in the tight mounting space between the vehicle body and the wheel.

[0008] Therefore, an objective of the present invention is to provide a shock absorber equipped with a vehicle height adjustment that can perform both a vehicle height adjustment and a damping force adjustment. Solution to the problem

[0009] To achieve the aforementioned objective, a shock absorber equipped with a vehicle height adjustment in the device for solving the problem of the present invention comprises: a shock absorber body containing a cylinder, a piston inserted into the cylinder in such a way that it is movable in the axial direction and divides the interior of the cylinder into an expansion-side chamber and a compression-side chamber filled with a fluid, a piston rod inserted into the expansion-side chamber, movable in the axial direction relative to the cylinder and connected to the piston, and an outer tube surrounding the cylinder;a separating element that divides the interior of the outer tube into a container and a reservoir; the container stores fluid; the reservoir is connected to the compression-side chamber to compensate for the volume of the piston rod entering and exiting the interior of the cylinder; a pump provided on the separating element that supplies fluid through the reservoir into and out of the interior of the cylinder; and a damping force adjustment valve provided on the separating element that is designed to adjust a damping force during expansion and compression of the shock absorber body.

[0010] In this type of shock absorber with adjustable ride height, damping force can be generated when the pump is stationary, as the shock absorber body expands and contracts to suppress vibrations of the vehicle body. The damping force can be adjusted to improve ride comfort. Furthermore, the ride height can be adjusted by operating the pump.Since the pump and damping force adjustment valve are provided on the separating element that divides the inside of the outer tube into the tank and reservoir in the shock absorber equipped with vehicle height adjustment, the pump and damping force adjustment valve can be concentrated on the shock absorber body, thus enabling overall downsizing, even when the pump and damping force adjustment valve are included, and simplifying installation in a tight mounting space between the vehicle body and the wheel of the vehicle. Brief description of the drawings Fig. Figure 1 is a longitudinal sectional view of a shock absorber equipped with vehicle height adjustment according to one embodiment. Fig. Figure 2 is a hydraulic circuit diagram of the shock absorber equipped with vehicle height adjustment according to one embodiment. Fig. Figure 3 is a top view of the shock absorber equipped with vehicle height adjustment according to one embodiment. Fig. Figure 4 is a side view of the shock absorber equipped with vehicle height adjustment in a first modification according to an embodiment. Fig. Figure 5 is a side view of the shock absorber equipped with vehicle height adjustment in a second modification according to one embodiment. Fig. Figure 6 is a side view of the shock absorber equipped with vehicle height adjustment in a third modification according to one embodiment. Fig. Figure 7 is a side view of the shock absorber equipped with vehicle height adjustment in a fourth modification according to one embodiment. Description of the embodiments

[0011] The present invention will now be described with reference to the embodiments illustrated in the drawings. As shown in Fig. Figure 1 shows a shock absorber SA equipped with vehicle height adjustment according to one embodiment, comprising a shock absorber body D, a container T for storing fluid, a reservoir R, a housing 30 serving as a separating element, a pump 31, and a damping force adjusting valve 18. The shock absorber SA, equipped with vehicle height adjustment, is connected between a vehicle body and a wheel in a vehicle (not shown), expands and contracts in response to the vibration impulses occurring during the vehicle's travel, and generates a damping force to suppress vibrations of the vehicle body.There are several modifications of the shock absorber equipped with a vehicle height adjustment according to one embodiment, but in the description of each modification, components common to those of the shock absorber SA equipped with a vehicle height adjustment of one embodiment are designated by the same reference numerals and a detailed description thereof is omitted to avoid overlap.

[0012] First, the shock absorber base body D is described. As in Fig. As shown in Figure 1, the shock absorber body D according to the present embodiment comprises a cylinder 1, a piston 2 which is inserted into the cylinder 1 in such a way that it is movable in the axial direction and which divides the interior of the cylinder 1 into an expansion-side chamber R1 and a compression-side chamber R2, a piston rod 3 which is inserted into the expansion-side chamber R1, is movable in the axial direction relative to the cylinder 1 and is connected to the piston 2, an intermediate tube 4 which surrounds the outer circumference of the cylinder 1, and an outer tube 5 which surrounds the cylinder 1 and is arranged in the outer circumference of the intermediate tube 4.

[0013] As described above, the intermediate tube 4 is inserted between the cylinder 1 and the outer tube 5, and annular gaps are formed between the cylinder 1 and the intermediate tube 4 and between the outer tube 5 and the intermediate tube 4.

[0014] Furthermore, a rod guide 7 is attached to an upper end of the cylinder 1 and an upper end of the intermediate tube 4. The rod guide 7 has an annular shape with an inner circumference into which the piston rod 3 is slidably inserted and is attached to an inner circumference of an upper end of the outer tube 5. A valve housing 6, which closes the lower end of the cylinder 1 and the lower end of the intermediate tube 4, is also attached to the lower end of the cylinder 1 and the lower end of the intermediate tube 4. A lower end of the outer tube 5 is closed by a bottom cap 13, which abuts the lower end of the valve housing 6. Thus, the cylinder 1, the intermediate tube 4, and the valve housing 6 are sandwiched between the bottom cap 13, which closes the lower end of the outer tube 5, and the rod guide 7, and are fixed immovably inside the outer tube 5.

[0015] The outer tube 5 contains an upper tube 5a and a lower tube 5b. The rod guide 7 described above is attached to the upper end of the upper tube 5a, and the upper end of the upper tube 5a is closed by the rod guide 7. Furthermore, the lower end of the upper tube 5a is connected to the upper end of the housing 30, which is attached to the outer circumferential surface of the intermediate tube 4. A lower end of the lower tube 5b is closed by the bottom cap 13, which contains a bracket 13a that allows attachment to a vehicle (not shown), and an upper end of this bracket is connected to the lower end of the housing 30.

[0016] As described above, the annular gap between the intermediate tube 4 and the outer tube 5 is vertically subdivided by the housing 30, with the container T being formed by the annular gap between the upper tube 5a, which surrounds the top of the intermediate tube 4 and the intermediate tube 4, and the reservoir R being formed by the annular gap between the lower tube 5b, which surrounds the bottom of the intermediate tube 4 and the intermediate tube 4.

[0017] In this way, the housing 30, which serves as a separating element, forms the container T and the reservoir R inside the outer tube 5. In addition to being filled with liquid, the container T is filled with gas. The gas filling the container T is preferably an inert gas such as nitrogen, but can also be atmospheric air or the like.

[0018] Furthermore, a bladder 14 with a tubular shape, serving as an elastic partition, is housed within the reservoir R. The upper and lower ends of the bladder 14 are sandwiched between an annular retaining ring 15 and the lower tube 5b, and between an annular retaining ring 16 and the lower tube 5b, respectively. The bladder 14 divides the reservoir R into a gas chamber RG, containing gas, and a liquid-filled liquid chamber RL. Compressed gas is enclosed in the gas chamber RG, which is divided by the bladder 14, constantly pressurizing the interior of the reservoir R. The elastic partition can also be a membrane.

[0019] In a section of the intermediate tube 4, which faces radially towards the housing 30, an opening 4a is provided, and the opening 4a communicates with the reservoir R via a passage 40 that opens from a section of the housing 30 facing the intermediate tube 4 and leads to the interior of the reservoir R. The cylinder 1 also includes an opening 1a that communicates with an annular gap between the cylinder 1 and the intermediate tube 4 near its upper end. The upper and lower ends of the annular gap formed between the cylinder 1 and the intermediate tube 4, which surrounds the outer circumference of the cylinder 1, are closed by the rod guide 7 and the valve housing 6, and the annular gap communicates via the opening 1a with the interior of the expansion-side chamber R1 inside the cylinder 1.Thus, the expansion-side chamber R1 and the reservoir R are connected to each other via the opening 1a, the annular gap between the cylinder 1 and the intermediate tube 4, the opening 4a and the passage 40, and a damping force adjustment passage VP is formed through the opening 1a, the annular gap between the cylinder 1 and the intermediate tube 4, the opening 4a and the passage 40.

[0020] Piston 2 is slidably inserted into cylinder 1 and in Fig. 1 is movable in a vertical direction, which is the axial direction relative to cylinder 1, and divides the interior of cylinder 1 into the liquid-filled expansion-side chamber R1 and the compression-side chamber R2. Furthermore, a rectifying passage 9 is provided on piston 2, which contains a piston passage 9a through which the expansion-side chamber R1 and the compression-side chamber R2 are connected, and a check valve 9b, which is provided in the piston passage 9a and allows only a flow of liquid from the compression-side chamber R2 to the expansion-side chamber R1.

[0021] The piston rod 3 penetrates the expansion-side chamber R1, is connected at one end to the piston 2, and is inserted into the cylinder 1 such that it is axially movable. The other end of the piston rod protrudes outwards through the rod guide 7 from the cylinder 1. The piston rod 3 is inserted axially along its entire length into the expansion-side chamber R1, but not into the compression-side chamber R2. A portion of the lower end of the piston rod 3 may be inserted into the compression-side chamber R2, but the piston rod 3 is not inserted axially along its entire length into the compression-side chamber R2.

[0022] The valve housing 6 is attached to the lower ends of the cylinder 1 and the intermediate pipe 4 to seal these ends. Furthermore, the valve housing 6 separates the compression-side chamber R2 inside the cylinder 1 from the reservoir R and includes an intake passage 17 with a passage 17a through which the compression-side chamber R2 and the reservoir R are connected, and a check valve 17b that allows only a fluid flow from the reservoir R to the compression-side chamber R2.

[0023] An end bolt 3a, which enables attachment to a vehicle body, is provided at the upper end of the piston rod 3, and an upper spring seat 20 with an annular shape is attached to the outer circumferential surface near the upper end. Furthermore, a lower spring seat 21 with an annular shape is attached to the outer circumferential surface of the upper tube 5a. A support spring S, formed from a coil spring located on the outer circumferential surface of the piston rod 3, is positioned between the upper spring seat 20, located at the upper end of the piston rod 3, and the lower spring seat 21, located on the outer circumferential surface of the upper tube 5a.Thus, when the shock absorber SA, equipped with a vehicle height adjustment, is arranged between the vehicle body and the wheel of the vehicle using the end bolt 3a of the piston rod 3 and the bracket 13a of the bottom cap 13, the vehicle body is elastically supported by the suspension spring S.

[0024] As in the Fig. 1 and Fig. As shown in Figure 2, the damping force adjustment valve 18 is installed in the center of the passage 40, which is provided in the housing 30 and forms part of the damping force adjustment passage VP. In the present embodiment, the damping force adjustment valve 18 is a solenoid valve comprising: a valve body 18a, provided in the housing 30 and inserted in the center of the passage 40; a spring 18b, which biases the valve body 18a in a direction to close the valve body 18a; a solenoid 18c, which, when energized, can generate a thrust in a direction to open the valve body 18a against the spring 18b; and a control passage 18d, which causes the pressure of the expansion-side chamber R1 to act with respect to the valve body 18a in the valve opening direction.The damping force-adjusting valve 18 can adjust the valve opening pressure by changing the current supplied to the solenoid 18c, maximize the resistance to fluid flow at maximum valve opening pressure during a period of non-excitation, maximize the resistance to fluid flow at minimum valve opening pressure when the current supplied to the solenoid 18c is maximized, and adjust the valve opening pressure between maximum and minimum according to the current. The damping force-adjusting valve 18 can also function as a solenoid valve that minimizes the valve opening pressure during periods of non-energy storage and maximizes the valve opening pressure when the current supplied to the solenoid is maximized.

[0025] Part of the damping force adjustment passage VP is formed by the annular gap between the cylinder 1 and the intermediate tube 4, by providing the intermediate tube 4, which surrounds the cylinder 1, on the outer circumferential surface of the cylinder 1. However, instead of the intermediate tube 4 and the opening 1a, a tube can be bridged between the rod guide 7 and the housing 30, the interior of which can be connected to the expansion-side chamber R1 via the passage formed in the rod guide 7 and to the reservoir R via the passage provided in the housing 30, and the damping force adjustment passage VP can be formed through the tube, the passage of the rod guide 7, and the passage of the housing 30.

[0026] The housing 30 then contains inside a hydraulic circuit C, a pump body 31a of the pump 31, which will be described later, and other components such as the solenoid 18c of the damping force adjusting valve 18, and as described in Fig. Figure 1 shows an opening 30a into which the intermediate tube 4, provided on the outer circumferential surface of the cylinder 1 of the supply passage D of the shock absorber D, is inserted. The housing 30 is then attached to the outer circumferential surface of the intermediate tube 4 and connected to the upper tube 5a and the lower tube 5b of the outer tube 5 by welding or the like. In addition to the hydraulic circuit C, the housing 30 contains a passage 40 that opens from the inner circumferential surface, which forms the opening 30a of the housing 30, and leads to the lower end of the housing 30. When the housing 30 is attached to the outer circumferential surface of the intermediate tube 4 and fastened to the outer tube 5, the passage 40 faces the opening 4a of the intermediate tube 4. In this way, the passage 40 is connected to the opening 4a and, together with the opening 4a, forms part of the damping force adjustment passage VP.

[0027] Furthermore, the hydraulic circuit C is provided inside the housing 30 and includes: a supply passage 32 and an outlet passage 33 through which the container T and the reservoir R are connected; a pair of check valves 34 and 35 provided in the supply passage 32, which define the supply passage 32 as a one-way passage, allowing only a fluid flow from the container T to the reservoir R; and an operating check valve 36 provided in the outlet passage 33.

[0028] The pump 31 is located in the center of the feed passage 32 and between the check valve 34 and the check valve 35. In the present embodiment, the pump 31 is a bidirectional feed pump designed to deliver fluid in two directions, and the delivery direction of the fluid is switched by a drive 31b between a forward rotation of the pump body 31a and a reverse rotation of the pump body 31a. Furthermore, the drive 31b of the pump 31 is located at the upper end of the feed passage 32. Fig. 1 attached to housing 30 serving as a separating element.

[0029] When pump 31 rotates forward under the force of drive 31b, check valves 34 and 35 open to draw fluid from container T and supply it to cylinder 1 via reservoir R. Pump 31 can be a bidirectional pump, such as an internal gear pump or an external gear pump. Furthermore, since check valves 34 and 35 are closed by the pressure of reservoir R on the high-pressure side when pump 31 stops, fluid is not discharged from reservoir R into container T through inlet 32.

[0030] As described above, the operating check valve 36 is located in the outlet passage 33. The operating check valve 36 does not open even when it receives pressure from reservoir R and blocks the outlet passage 33. However, when control pressure from pump 31 acts through a control passage 37, the operating check valve 36 opens and allows fluid flow from reservoir R to container T. The control passage 37 connects an outlet port, through which the pump body 31a discharges fluid when pump 31 reverses, to the operating check valve 36. When pump 31 reverses, the control pressure acts on the operating check valve 36, and the operating check valve 36 opens to allow the flow of fluid from reservoir R to container T.

[0031] Furthermore, the hydraulic circuit C includes: a reservoir T; a reverse rotary valve 38, through which the check valve 35, located in the center of the supply passage 32 and on the reservoir side, is connected to the pump 31; and a check valve 39, provided in the reverse rotary valve 38, which allows only a fluid flow from reservoir T to the pump 31. When the pump 31 rotates in reverse, the check valves 34 and 35 in the supply passage 32 remain closed, but because the check valve 39 is open, the pump 31 can draw fluid from reservoir T, discharge the fluid to the control passage 37, and cause the control pressure to act on the operating check valve 36.

[0032] The solenoid 18c of the damping force adjusting valve 18 is attached to a lower part on one side opposite the actuator 31b with respect to the housing 30, which is in Fig. 1 serves as a separating element. As described above, the actuator 31b of the pump 31 and the solenoid 18c of the damping force adjusting valve 18 are each mounted on opposite sides, with the housing 30 arranged vertically between them as a separating element, and are arranged in positions that overlap vertically with respect to the housing 30, as shown in Fig. Figure 3 illustrates this. By attaching the actuator 31b and the solenoid 18c to positions that overlap in the vertical direction, the outer circumferential shape (outer form) of the actuator 31b and the outer circumferential shape (outer form) of the solenoid 18c overlap at least partially when the shock absorber SA equipped with vehicle height adjustment is viewed from an axial direction. In the shock absorber SA equipped with vehicle height adjustment of the present embodiment, when viewed from an axial direction, the actuator 31b and the solenoid 18c are arranged with respect to the housing 30 such that a center point Do of the feed passage D, a center point Mo of the outer form of the actuator 31b, and a center point So of the outer form of the solenoid 18c are aligned on a straight line.Therefore, the mounting sections of the drive 31b and the solenoid 18c can be integrated in a circumferential position with respect to the housing 30 when viewed from the shock absorber body D, and the external shape of the shock absorber SA equipped with vehicle height adjustment can be reduced to the greatest extent.

[0033] As described above, the pump 31 and the damping force adjusting valve 18 are arranged in the shock absorber base body D via the housing 30 which serves as a separating element, and together with the shock absorber base body D form the shock absorber SA equipped with a vehicle height adjustment.

[0034] The operation of the shock absorber SA, equipped with vehicle height adjustment, is then described. First, a function is described at the time of extension of the shock absorber SA, in which the piston 2 is in Fig. 1 moves upwards relative to cylinder 1. As piston 2 moves upwards relative to cylinder 1, the expansion-side chamber R1 is compressed, causing fluid to move from the expansion-side chamber R1 through the damping force adjustment passage VP and the damping force adjustment valve 18 to reservoir R. Since there is resistance as the fluid passes through the damping force adjustment valve 18, the pressure in the expansion-side chamber R1 increases. When the shock absorber SA, equipped with vehicle height adjustment, expands, piston 2 moves upwards inside cylinder 1 to expand the compression-side chamber R2. This opens the check valve 17b provided in the valve housing 6, allowing fluid from reservoir R to enter the compression-side chamber R2 through the intake passage 17. Thus, reservoir R compensates for the volume of piston rod 3 exiting from inside cylinder 1.When the shock absorber SA, equipped with vehicle height adjustment, extends, the pressure in the expansion-side chamber R1 increases, while the pressure in the compression-side chamber R2 becomes essentially equal to the pressure in the reservoir R, and a difference arises between the pressure in the expansion-side chamber R1 and the pressure in the compression-side chamber R2, so that the shock absorber SA, equipped with vehicle height adjustment, generates a damping force that prevents the expansion of the shock absorber body D.Furthermore, since the resistance to the flow of fluid through the damping force adjustment valve 18 can be adjusted according to the amount of current supplied to the damping force adjustment valve 18, a height adjustment can be carried out with respect to the damping force which prevents the extension of the shock absorber body D generated by the shock absorber SA equipped with a vehicle height adjustment.

[0035] On the other hand, during the contraction of the shock absorber SA equipped with a vehicle height adjustment, in which the piston 2 moves into Fig. As the cylinder 1 moves downwards, the compression-side chamber R2 is compressed, causing the check valve 9b to open and fluid to flow into the expansion-side chamber R1. This fluid then expands from the compression-side chamber R2 via the rectifying passage 9. At the moment of contraction of the shock absorber SA, which is equipped with vehicle height adjustment, the piston rod 3 enters the interior of cylinder 1. This causes the fluid volume in cylinder 1 to increase by the volume of the piston rod 3 entering the cylinder 1. The excess fluid then passes from the expansion-side chamber R1 into the reservoir R via the damping force adjustment passage VP and the damping force adjustment valve 18. In this way, the reservoir R compensates for the volume of the piston rod 3 entering the interior of cylinder 1.Since the damping force adjustment valve 18 opposes the fluid flow, the pressure inside the cylinder 1 increases, and a pressure-bearing area facing the compression-side chamber R2 is larger by a cross-sectional area of ​​the piston rod 3 than a pressure-bearing area facing the expansion-side chamber R1 of the piston 2. Thus, the shock absorber SA, equipped with vehicle height adjustment, generates a damping force that prevents contraction of the supply passage D. Furthermore, since the resistance to the fluid flow offered by the damping force adjustment valve 18 can be adjusted according to the flow rate supplied to the damping force adjustment valve 18, height adjustment can be achieved by means of the damping force, which prevents contraction of the shock absorber body D generated by the shock absorber SA equipped with vehicle height adjustment.

[0036] The operation of the shock absorber SA, equipped with a vehicle height adjustment function, by driving the pump 31 is then described. First, as described above, the reservoir R is pressurized by the compressed gas enclosed in bladder 14, and the pressure in reservoir R is transferred to cylinder 1 via the intake passage 17 and the rectifier passage 9. In a stationary state, the pressure inside cylinder 1 is essentially equal to the pressure in reservoir R. This means that the interior of cylinder 1 is also continuously pressurized by the compressed gas enclosed in bladder 14.

[0037] The pressure in the compression-side chamber R2 acts in a direction that moves the piston 2 in Fig. 1 pushes upwards, and the pressure in the expansion-side chamber R1 acts in a direction that pushes the piston 2 into Fig. 1 pushes downwards. As described above, since the pressure-bearing area that absorbs the pressure of the compression-side chamber R2 of the piston 2 is larger by the cross-sectional area of ​​the piston rod 3 than the pressure-bearing area that absorbs the pressure of the expansion-side chamber R1 of the piston 2, the piston 2 is pushed downwards. Fig. 1 is continuously pre-tensioned upwards by a force whose value is calculated by multiplying the pressure inside cylinder 1 by the cross-sectional area of ​​the piston rod 3. Since the force for pre-tensioning the piston 2 upwards is Fig. Since the pressure inside cylinder 1 is proportional to the pressure inside cylinder 1, when pump 31 is driven to supply the fluid through reservoir R into cylinder 1, the pressure inside cylinder 1 can be increased to increase the force to preload piston 2 upwards so that the shock absorber base body D can be extended.

[0038] When pump 31 rotates forward by the drive of actuator 31b, check valves 34 and 35 open to draw liquid from container T through inlet 32 ​​and supply it to reservoir R. As the pressure in reservoir R increases due to the liquid supplied by pump 31, check valve 17b opens, and liquid is also drawn from reservoir R through inlet 17 into the compression-side chamber R2. As described above, when driven in the forward direction, pump 31 can draw liquid from container T and supply it to cylinder 1.

[0039] Then, the piston 2 is pushed upwards by the inflow of fluid into the compression-side chamber R2, the damping force adjustment valve 18 is opened by the expansion-side chamber R1, whose volume decreases, and the fluid moves from the expansion-side chamber R1 through the damping force adjustment passage VP to the reservoir R. When the pump 31 is then driven to supply the fluid from the container T into the cylinder 1, the pressure inside the reservoir R and the pressure in the cylinder 1 increase essentially uniformly.When pump 31 is stopped after the vehicle height has reached a desired level due to the pressure increase in the compression-side chamber R2, check valves 34 and 35 and damping force adjustment valve 18 are closed, thus maintaining the fluid volumes inside reservoir R and cylinder 1 and maintaining the vehicle height. In a case where pump 31 is rotated forward to supply fluid from reservoir T to the compression-side chamber R2 to extend the shock absorber body D and increase the vehicle height, the fluid from the expansion-side chamber R1, whose volume is reduced due to the movement of piston 2, moves upwards relative to cylinder 1 to reservoir R through the damping force adjustment valve 18.Therefore, if the resistance of the damping force adjusting valve 18 is minimized, the force that prevents the piston 2 from rising is minimized, and the energy consumption in the pump 31 can be reduced and the vehicle height can be increased quickly.

[0040] In contrast to the description above, when the fluid is diverted from reservoir R into container T, the pressure inside cylinder 1 decreases, thus reducing the force required to preload piston 2 upwards to lower the vehicle. When pump 31 then reverses due to the drive of actuator 31b, check valve 39 opens while check valves 34 and 35 remain closed. Therefore, during reverse rotation, pump 31 draws a sufficient quantity of fluid from container T through reverse passage 38, causing the delivery pressure to act as a control pressure on operating check valve 36 via control passage 37, opening the operating check valve 36. With operating check valve 36 open, reservoir R and container T are connected via outlet passage 33, allowing fluid to flow from reservoir R into container T.

[0041] As the fluid moves from reservoir R to tank T, the pressure in reservoir R drops, the damping force adjustment valve 18 opens, and the fluid moves from the expansion-side chamber R1 to reservoir R2. Additionally, the check valve 9b opens due to the fluid drop in the expansion-side chamber R1, and the fluid moves from the expansion-side chamber R1 through the rectifying passage 9 to the compression-side chamber R2. Therefore, when pump 31 is reversed to discharge the fluid from reservoir R to tank T, the pressure inside reservoir R and the pressure inside cylinder 1 are reduced substantially equally, thus decreasing the force required to bias the piston 2 upwards and lowering the vehicle height.When the vehicle height has reached a desired height and the drive 31b is stopped, the control pressure to the operating check valve 36 is released and the operating check valve 36 is closed to interrupt the connection between the reservoir R and the container T via the outlet passage 33, and the check valves 34 and 35 are also kept in a closed state so that the fluid quantities in the reservoir R and the fluid quantities inside the cylinder 1 can be maintained and the vehicle height can also be maintained.In a case where pump 31 is reverse-rotated to discharge fluid from reservoir R into tank T and the shock absorber body D is contracted to lower the vehicle height, the fluid moves from the expansion-side chamber R1 through the damping force adjustment valve 18 into reservoir R by moving towards the bottom of piston 2 relative to cylinder 1. Thus, when the resistance of the damping force adjustment valve 18 is minimized, the resistance preventing piston 2 from lowering is also minimized, and the vehicle height can be lowered quickly, while the rapid lowering of the vehicle height is mitigated. As described above, the shock absorber SA, equipped with a vehicle height adjustment, can adjust the vehicle height by increasing or decreasing the pressure in cylinder 1 by supplying and extracting fluid from cylinder 1 by driving pump 31.In the shock absorber SA of the present embodiment, which is equipped with a vehicle height adjustment, the pump 31, at the time of forward rotation, discharges fluid from the container T into the reservoir R and, at the time of reverse rotation, applies a control pressure to the operating check valve 36 of the outlet passage 33 in order to open the operating check valve 36 and discharge the fluid from the reservoir R into the container T. The hydraulic circuit C can be configured such that the operating check valve 36 is omitted and the fluid can be drawn from the reservoir R and discharged into the container T during the reverse rotation of the pump 31.

[0042] It should be noted that the hydraulic circuit C provided in the housing 30 includes a relief passage 41 through which the container T and the reservoir R are connected, and a relief valve 42 located in the relief passage 41. This valve opens when the pressure in the reservoir R becomes too high. If the pressure in the reservoir R becomes excessive due to contraction of the shock absorber body D or a supply of fluid from the pump 31 to the reservoir R, the pressure relief valve 42 opens to release the fluid in the reservoir R through the pressure passage 41 to the container T. This prevents the pressure in the reservoir R from becoming excessive and prevents fluid from escaping the shock absorber body D.

[0043] As described above, the shock absorber SA equipped with vehicle height adjustment comprises: a cylinder 1; a piston 2 inserted into the cylinder 1 so that it is movable in the axial direction and divides the interior of the cylinder 1 into a fluid-filled expansion-side chamber R1 and a compression-side chamber R2; a piston rod 3 inserted into the expansion-side chamber R1, movable in the axial direction with respect to the cylinder 1 and connected to the piston 2; a shock absorber body D with an outer tube 5 surrounding the cylinder 1; a housing (dividing element) 30 dividing the interior of the outer tube 5 into a container T and a reservoir R, the container T storing fluid and the reservoir R being connected to the compression-side chamber R2 to compensate for the volume of the piston rod 3 entering and exiting the interior of the cylinder 1;a pump 31, which is provided in the housing (separating element) 30 and supplies the fluid through the reservoir R into the interior of the cylinder 1 and discharges it from there; and a damping force adjusting valve 18, which is provided in the housing (separating element) 30 and can adjust a damping force during the extension and contraction of the shock absorber body D.

[0044] In the shock absorber SA, thus designed and equipped with a vehicle height adjustment, the damping force can be generated when the pump 31 is stationary, as the shock absorber body D expands and contracts to dampen the vibrations of the vehicle body. The damping force can be adjusted to improve ride comfort. Furthermore, by turning the pump 31 forward, fluid can be supplied from the reservoir T into the cylinder 1 to extend the shock absorber body D, thus increasing the vehicle height. By turning the pump 31 backward, the operating check valve 36 can be opened to discharge the fluid from inside the cylinder 1 through the outlet passage 33 into the reservoir T, thus contracting the shock absorber body D and lowering the vehicle height.

[0045] Then, in the shock absorber SA equipped with a vehicle height adjustment, since the pump 31 and the damping force adjustment valve 18 are provided in the housing (dividing element) 30, which divides the interior of the outer tube 5 into the container T and the reservoir R, the pump 31 and the damping force adjustment valve 18 can be mounted in a concentrated manner on the shock absorber body D, so that the overall miniaturization is possible even when the pump 31 and the damping force adjustment valve 18 are included, and installation in a narrow mounting space between the vehicle body and the wheel of the vehicle becomes easier, and components required for mounting the pump 31 and the damping force adjustment valve 18 are combined into a single unit, thereby reducing the number of components and lowering manufacturing costs.It is evident from the foregoing that, according to the present embodiment of the shock absorber SA equipped with a vehicle height adjustment, a reduction in size is possible, while both the adjustment (setting) of the vehicle height and the adjustment (setting) of the damping force are possible.

[0046] Furthermore, in the shock absorber SA equipped with vehicle height adjustment, even when the pump 31 is driven to supply the fluid from the container T to the reservoir R, and the pressure of the gas in reservoir R increases and the spring constant of the gas increases, or even when the fluid is discharged from reservoir R through the outlet passage 33 into container T, and the pressure of the gas in reservoir R decreases and the spring constant of the gas decreases, the damping force adjusting valve 18 can adjust the resistance encountered by the fluid as it flows through the shock absorber body D during expansion and contraction, thus changing the damping coefficient. A damping ratio ζ can be determined by ζ = C / {2 × (m·K) 1 / 2The damping coefficient can be increased by increasing the resistance to the fluid flowing through the damping force adjustment valve 18 by the same amount, even if the spring constant K of the gas in reservoir R increases due to the addition of liquid to reservoir R. Conversely, even if the spring constant K of the gas in reservoir R decreases due to the discharge of fluid from reservoir R into container T, the damping coefficient can be decreased by reducing the resistance to the fluid flowing through the damping force adjustment valve 18 by the same amount. Therefore, according to the shock absorber SA of the present embodiment, which is equipped with vehicle height adjustment, it is possible to suppress the change in the damping ratio ζ before and after the vehicle height adjustment.It follows from the above that, according to the shock absorber SA of the present embodiment, which is equipped with a vehicle height adjustment, even when the vehicle height is adjusted by increasing or decreasing the pressure in cylinder 1, the change in the damping ratio can be suppressed, so that the deterioration of the driving comfort in the vehicle can be suppressed.

[0047] Furthermore, the shock absorber SA of the present embodiment, which is equipped with a vehicle height adjustment, has a housing (separating element) 30, which has a supply passage 32, through which the container T and the reservoir R are connected and which is equipped with the pump 31, an outlet passage 33, through which the container T and the reservoir R are connected, an operating check valve 36, which is provided in the outlet passage 33 and which only allows the flow of liquid from the reservoir R to the container T at the time of valve opening, and a damping force adjustment passage VP through which liquid flows during the expansion and contraction of the shock absorber supply passage D and which is equipped with the damping force adjustment valve 18.The pump 31 is a bidirectional feed pump which, when rotating forward, supplies liquid from the container T to the reservoir R and, when rotating backward, exerts control pressure on the operating check valve 36 in order to open the operating check valve 36.

[0048] According to the shock absorber SA with vehicle height adjustment configured in the present embodiment, since the hydraulic circuit C and the damping force adjustment passage VP, which are required to actuate the pump 31 and the damping force adjustment valve 18, are integrated in the housing (separating element) 30, the shock absorber SA with vehicle height adjustment can be further miniaturized. Furthermore, in the shock absorber SA with vehicle height adjustment configured in the present embodiment, since the pump 31 and the damping force adjustment valve 18 are arranged in an intermediate section of the cylinder 1 above the lower end of the cylinder 1, the actuator 31b and the solenoid 18c can be protected from stone impacts during driving or from water splashes when driving on a flooded road.

[0049] Furthermore, the shock absorber SA of the present embodiment, which is equipped with a vehicle height adjustment, comprises the pump 31, a pump body 31a provided in the feed passage 32 and having a drive 31b that drives the pump body 31a, the damping force adjusting valve 18, a valve body 18a provided in the damping force adjusting passage VP and having a solenoid 18c that exerts a thrust on the valve body 18a, and the drive 31b and the solenoid 18c being attached to the housing (separating element) 30, the housing (separating element) 30 being sandwiched between them in the vertical direction and both being arranged in positions that overlap in the vertical direction with respect to the housing (separating element) 30.

[0050] In the shock absorber SA of the present embodiment, which is equipped with a vehicle height adjustment, the area of ​​the housing (separating element) 30, viewed from the axial direction of the shock absorber SA equipped with a vehicle height adjustment, can be reduced, since the drive 31b and the solenoid 18c are mounted separately above and below the housing (separating element), compared to the case in which both the drive 31b and the solenoid 18c are mounted either above or below the housing (separating element) 30.Furthermore, in the shock absorber SA with vehicle height adjustment of the present embodiment, since the actuator 31b and the solenoid 18c are mounted separately above and below the housing (separating element), the size of the shock absorber SA with vehicle height adjustment can be reduced in the radial direction compared to the axial direction, compared to the case where the actuator 31b and the solenoid 18c are mounted on a side surface of the housing (separating element) 30. Therefore, a further reduction in size is possible according to the shock absorber SA with vehicle height adjustment of the present embodiment.In the shock absorber SA of the present embodiment equipped with a vehicle height adjustment, when the shock absorber SA equipped with a vehicle height adjustment is viewed from an axial direction and the drive 31b and the solenoid 18c are arranged with respect to the housing 30 such that the center of the feed passage D, the center of the outer shape of the drive 31b and the center of the outer shape of the solenoid 18c are aligned on a straight line, the outer shape of the shock absorber SA equipped with a vehicle height adjustment can be reduced to the greatest extent when viewed from an axial direction.

[0051] The actuator 31b and the solenoid 18c can be installed either above or below the housing (separating element) 30. Even in this case, the shock absorber SA, equipped with vehicle height adjustment, can be reduced in size if both the actuator 31b and the solenoid 18c are arranged in a housing (separating element) 30, thus preserving the effect of the present invention. Furthermore, since the actuator 31b and the solenoid 18c are located on one of the upper and lower sides of the housing (separating element) 30, the wiring between the actuator 31b and the solenoid 18c can be easily routed. As shown in Fig. As shown in Figure 4, when the actuator 31b and the solenoid 18c are arranged above the housing (separator) 30, the housing 30 serves as a shield to reduce the possibility of a stone or spray from the road surface colliding with the actuator 31b and the solenoid 18c while the vehicle is traveling. Furthermore, it is also possible to use a structure in which one of the actuators 31b and the solenoid 18c is installed either above or below the housing (separator) 30, and the other actuator 31b and the solenoid 18c is installed on a side face of the housing (separator) 30.

[0052] The supply passage D in the shock absorber SA of the present embodiment, which is equipped with vehicle height adjustment, includes the intake passage 17, which only allows the flow of fluid from the reservoir R to the compression-side chamber R2, and the equalization passage 9, which only allows the flow of fluid from the compression-side chamber R2 to the expansion-side chamber R1, and the damping force adjustment passage VP connects the expansion-side chamber R1 and the reservoir R. According to the shock absorber SA with vehicle height adjustment designed in this way, even when the shock absorber body D is set to the equal-run type and is either extended or retracted, the fluid is always directed through the damping force adjustment passage VP from inside the cylinder 1 and discharged into the reservoir R.Therefore, both the damping force at the time of expansion and the damping force at the time of compression can be adjusted by a damping force adjusting valve 18.

[0053] In the shock absorber SA with vehicle height adjustment described above, only the rectification passage 9 is provided in the piston 2, and only the intake passage 17 is provided in the valve housing 6. However, the piston 2 can be provided with an expansion-side damping passage containing an expansion-side damping valve that resists the flow of fluid from the expansion-side chamber R1 to the compression-side chamber R2, and the valve housing 6 can be provided with a compression-side damping passage containing a compression-side damping valve that resists the flow of fluid from the compression-side chamber R2 to the reservoir R.Furthermore, if the flow of fluid through the damping force adjustment passage VP in both directions can be resisted by the damping force adjustment valve 18 itself or by adjusting the passage, the damping force adjustment passage VP can be provided in such a way that the expansion-side chamber R1 and the compression-side chamber R2 are connected to each other.In this case, for example, it is sufficient that the annular gap between the cylinder 1 and the intermediate pipe 4 is divided by the housing 30 into an upper chamber and a lower chamber, wherein the upper chamber is connected to the expansion-side chamber R1 through the opening 1a of the cylinder 1, the lower chamber is connected to the compression-side chamber R2 through an opening near the lower end of the cylinder 1, a passage connecting the upper chamber and the lower chamber is provided in which the housing 30 is provided as a separating element instead of the passage 40, and the damping force adjusting valve 18 is provided in the passage provided in the housing 30.

[0054] Furthermore, in a case where the damping force adjustment passage VP is provided such that the expansion-side chamber R1 and the compression-side chamber R2 are connected to each other, the shock absorber body D can assume a configuration similar to a so-called monotube shock absorber, in which the valve housing 6 is omitted and the compression-side chamber R2 and the reservoir R are continuous.

[0055] Furthermore, in the shock absorber SA of the present embodiment, which is equipped with vehicle height adjustment, the resistance opposing the flow of fluid in the damping force adjustment valve 18 is reduced as the fluid is supplied to and discharged from the cylinder 1 to expand and contract the shock absorber body D. According to the shock absorber SA with vehicle height adjustment designed as described above, because the resistance of the damping force adjustment valve 18 is reduced as fluid is supplied to and discharged from the cylinder 1, fluid moves easily within the cylinder 1 and the reservoir R, the energy consumption of the pump 31 can be reduced, and the shock absorber body D can be expanded and contracted quickly.

[0056] Furthermore, in the shock absorber SA equipped with a vehicle height adjustment according to the present embodiment, the drive 31b is arranged in the piston rod side which, with respect to the housing 30, forms the upper side in Fig. In this configuration, the housing 30 is positioned between the actuator 31b and a road surface. The housing 30 acts as a shield to reduce the likelihood of a stone or spray from the road surface colliding with the actuator 31b while the vehicle is in motion. Therefore, the shock absorber SA, configured in this way with vehicle height adjustment, can enhance the protective effect of the actuator 31b. The actuator 31b can be mounted below the housing (separator) 30, and the solenoid 18c can be mounted above the housing (separator) 30.

[0057] In the shock absorber SA of the present embodiment, which is equipped with a vehicle height adjustment, the housing (dividing element) 30 is attached to the outer circumferential surface of the intermediate tube 4 in order to vertically divide the annular gap between the outer tube 5 and the intermediate tube 4, thus creating a division into the container T and the reservoir R. However, the intermediate tube 4 can be omitted, the upper tube 5a and the lower end of the cylinder 1 can be closed by the housing (dividing element) 30, and the container T can be formed by the annular gap between the upper tube 5a of the outer tube 5 and the cylinder 1, and the entire interior of the lower tube 5b can be used as the reservoir R.

[0058] Subsequently, a shock absorber SA1 equipped with a vehicle height adjustment is used in a second modification of a Fig. The embodiment shown in Figure 5 is described. In the second modification of the shock absorber SA1, which is equipped with a vehicle height adjustment, the lower spring seat 21 is omitted in order to bring the housing 30 into a disc shape as a separating element, wherein the lower end of the support spring S is supported by the housing 30 and the support spring S is arranged between the housing 30 and the upper spring seat 20, which is provided at the upper end of the piston rod 3.

[0059] In the SA1 shock absorber, equipped with vehicle height adjustment in the second modification, the drive 31b of the pump 31 is located at the lower end in Fig. 5 is attached, which is located on an opposite piston rod side of the housing 30 as a separating element. The solenoid 18c of the damping force adjusting valve 18 is similar to the actuator 31b as a separating element at the lower end in Fig. 5 attached, which is located on the opposite side of the piston rod in relation to the housing 30.

[0060] As described above, in the second modification of the SA1 shock absorber equipped with a vehicle height adjustment, the pump 31 and the damping force adjusting valve 18 are arranged via the housing 30 as a separating element in the supply passage D of the shock absorber.

[0061] The housing 30 is arranged opposite the upper spring seat 20 in a vertical direction and contains a raised section 30b with an annular shape, extending from the outer circumferential side towards the piston rod side, which is in Fig. 5 the upper side, protrudes. The support spring S, formed from a helical spring and arranged on the outer circumferential surface of the piston rod 3, is located between the upper spring seat 20, provided at the upper end of the piston rod 3, and the upper end of the housing 30 in Fig. 5. Therefore, when the shock absorber SA1, equipped with vehicle height adjustment, is arranged between the vehicle body and the wheel of the vehicle using the end bolt 3a of the piston rod 3 and the bracket 13a of the bottom cap 13 described below, the vehicle body is elastically supported by the suspension spring S. As described above, the actuator 31b in the pump 31 and the solenoid 18c in the damping force adjusting valve 18 are mounted on the opposite piston rod side of the housing 30 as a separating element, so that no interference occurs with the suspension spring S mounted on the piston rod side of the housing 30.Even when the actuator 31b and the solenoid 18c are attached to the housing 30, and the lower end of the spring S is supported by the housing 30, it is not necessary to increase the overall length of the shock absorber SA1 equipped with vehicle height adjustment, and it is also possible to avoid increasing the radial size of the housing 30. Since the lower end of the spring S is mounted in the raised section 30b of the housing 30, radial displacement relative to the housing 30 is prevented.

[0062] As described above, the shock absorber SA1, equipped with vehicle height adjustment, in its second modification comprises: a cylinder 1; a piston 2, which is inserted into the cylinder 1 so that it is movable in the axial direction and which divides the interior of the cylinder 1 into a fluid-filled expansion-side chamber R1 and a compression-side chamber R2; a piston rod 3, which is inserted into the expansion-side chamber R1, is movable in the axial direction with respect to the cylinder 1 and is connected to the piston 2; a shock absorber body D with an outer tube 5 that surrounds the cylinder 1;a housing (separating element) 30 that divides the interior of the outer tube 5 into a container T and a reservoir R, wherein the container T stores liquid, the reservoir R is connected to the compression-side chamber R2 to compensate for a volume of the piston rod 3 entering and exiting the interior of the cylinder 1; a pump body 31a provided in the housing (separating element) 30 that supplies liquid through the reservoir R into and out of the cylinder 1; a pump 31 with a drive 31b that can drive the pump body 31a and is attached to a piston rod side of the housing (separating element) 30 opposite the housing; and the support spring S, which is arranged between the piston rod 3 and the housing (separating element) 30.

[0063] In the shock absorber SA1, designed in this way and equipped with a vehicle height adjustment, a function for attaching the pump 31 to the shock absorber body D and a function for holding the retaining spring S in the housing (separating element) 30 can be integrated such that the interior of the outer tube 5 is divided into the reservoir T and the reservoir R, and the actuator 31b is attached to the opposite piston rod side of the housing (separating element) 30, and the retaining spring S is arranged on the piston rod side of the housing (separating element) 30. Therefore, even when the retaining spring S is provided in addition to the pump 31 required for the vehicle height adjustment, the actuator 31b and the retaining spring S are arranged in positions that are axially offset, with the housing (separating element) 30 positioned between them, and do not interfere with each other.Therefore, according to the shock absorber SA1 configured with vehicle height adjustment, the drive 31b and the suspension spring S can be arranged in the shock absorber body D without increasing the overall length of the shock absorber body D. From the above, according to the second modification of the shock absorber SA1 equipped with vehicle height adjustment, an increase in overall length can be avoided while still allowing vehicle height adjustment, and the mountability on the vehicle is not affected.

[0064] Furthermore, in the SA1 shock absorber of the second modification, which is equipped with vehicle height adjustment, since the housing (separating element) 30 also serves as a lower spring seat supporting the lower end of the suspension spring S, it is not necessary to provide a separate lower spring seat supporting the lower end of the suspension spring S, and it is also possible to reduce the number of components and lower the manufacturing costs.

[0065] Furthermore, according to the SA1 shock absorber of the second modification, which is equipped with a vehicle height adjustment, since the drive 31b is mounted on the opposite piston rod side of the housing (separating element) 30 and the support spring S is arranged on the piston rod side of the housing (separating element) 30, it is also possible, even when the support spring S is included, to mount the drive 31b on the housing (separating element) 30 without increasing the outer circumferential shape of the housing (separating element) 30.

[0066] In the SA1 shock absorber of the second modification, equipped with vehicle height adjustment, the pump 31 and the damping force adjustment valve 18 are provided in the housing (separating element) 30, which divides the interior of the outer tube 5 into the reservoir T and the reservoir R, and the solenoid 18c in the damping force adjustment valve 18 is attached to the piston rod side of the housing (separating element) 30. According to the SA1 shock absorber with vehicle height adjustment of the second modification thus designed, the pump 31 and the damping force adjustment valve 18 can be concentrated on one section with respect to the shock absorber body D, and the suspension spring S is arranged in a position offset axially from the pump 31 and the damping force adjustment valve 18, with the housing (separating element) 30 positioned between them and not interfering with their operation.Therefore, according to the SA1 shock absorber of the second modification, which is equipped with vehicle height adjustment, a complete reduction in size is possible even when including the pump 31, the damping force adjustment valve 18, and the suspension spring S. Installation in a confined space between the vehicle body and the wheel is simplified, and the components required for mounting the pump 31 and the damping force adjustment valve 18 are combined into a single unit, thus reducing the number of components and lowering manufacturing costs. It follows from the above that, according to the SA shock absorber of the present embodiment, a reduction in size is possible while allowing for both vehicle height adjustment and damping force adjustment.

[0067] In the shock absorber SA1 described above, which is equipped with vehicle height adjustment, the housing 30 directly supports the lower end of the suspension spring S as a separating element. However, in the shock absorber SA2, which is equipped with vehicle height adjustment, in the third modification described in Fig. As shown in Figure 6, the housing 30 has a spring seat mounting section 30c with an annular shape as a separating element, which extends from the upper end around the opening 30a in Fig. 6 rises around, and includes a lower spring seat 21 with an annular shape, which is arranged in the outer circumference of the spring seat mounting section 30c.

[0068] The spring seat mounting section 30c extends around the opening 30a of the housing 30, surrounding the outer tube 5, and is formed in a stepped shape comprising a circumferential surface of a circular annular shape along the circumferential direction of the shock absorber base body D and an annular surface orthogonal to the axial direction of the shock absorber base body D. The pump 31 is provided on the outer circumferential side of the spring seat mounting section 30c with respect to the housing 30.

[0069] The lower spring seat 21 comprises a tubular guide tube 21a, which is attached to the circumferential surface of the spring seat mounting section 30c and has a bottom surface that rests against an upwardly directed annular surface in the spring seat mounting section 30c, and a flange-shaped spring seat section 21b that extends radially from an upper end of the guide tube 21a and supports the lower end of the suspension spring S. In this way, it is not necessary, as with the SA2 shock absorber in the third modification equipped with vehicle height adjustment, since the housing (separating element) 30 contains the lower spring seat 21, which supports the lower end in Fig. 3, which is a cylinder-side end of the support spring S, supports the housing (separating element) 30 in a shape that directly supports the cylinder-side end of the support spring S, and the degree of freedom in the design of the housing (separating element) 30 is increased.

[0070] The spring S is arranged between the upper spring seat 20 and the lower spring seat 21. The housing 30 receives an axial preload force from the spring S via the lower spring seat 21 through the spring seat mounting section 30c. Since the pump 31 is positioned on the outer circumferential side of the spring seat mounting section 30c with respect to the housing 30, and a line of action of the spring S preload force passes through the lower spring seat 21, the spring seat mounting section 30c and the lower tube 5b of the outer tube 5 act in such a way that they bypass the pump 31, and the pump 31 is not affected by the spring S preload force.Thus, according to the SA2 shock absorber of the third modification, which is equipped with a vehicle height adjustment, even when the structure in which the preload force of the suspension spring S is absorbed by the housing (separating element) 30 is used, the preload force of the suspension spring S does not act on the pump 31, and the smooth operation of the pump 31 can be ensured.

[0071] Furthermore, the housing 30 contains a drive cover 22 in a tubular shape that surrounds the circumference of the drive 31b, which is attached to the opposite side of the piston rod, which is in Fig. 6 is the lower end of the housing 30. Since the actuator 31b is thus surrounded by the actuator cover 22, the actuator 31b in the pump 31 can be protected from stone chips or similar hazards while the vehicle is in motion. In the present embodiment, the actuator cover 22 also accommodates the solenoid 18c of the damping force adjusting valve 18 in addition to the actuator 31b, so that not only the actuator 31b but also the solenoid 18c is protected from stone chips or the like while the vehicle is in motion.

[0072] Subsequently, a shock absorber SA3 equipped with vehicle height adjustment is used in a fourth modification of a Fig. The embodiment shown in section 7 is described. Fig. Figure 7 shows that the shock absorber SA3, in its fourth modification and equipped with vehicle height adjustment, comprises: a cylinder 1; a piston 2 inserted into the cylinder 1 so that it is movable in the axial direction and divides the interior of the cylinder 1 into a fluid-filled expansion-side chamber R1 and a compression-side chamber R2; a piston rod 3 inserted into the expansion-side chamber R1, movable in the axial direction relative to the cylinder 1 and connected to the piston 2; a housing 301 as a separating element, attached to an outer circumference of an intermediate section of the cylinder 1; an intermediate tube 43 that surrounds the housing 301 of the cylinder 1 at the top and forms an annular passage P that communicates with the expansion-side chamber R1 between the cylinder 1 and the intermediate tube 43;an upper tube 5a that surrounds the outer circumference of the intermediate tube 43 and forms a container T that stores liquid between the intermediate tube 43 and the cylinder 1; a lower tube 5b that surrounds the bottom of the housing 301 of the cylinder 1 and forms a reservoir R that is connected to the compression-side chamber R2 between the lower tube 5b and the cylinder 1; a pump 31 that is provided in the housing 301 and supplies liquid to and from the cylinder 1 via the reservoir R;a separating passage 44, through which an annular passage P and the reservoir R are connected, the separating passage 44 being provided in the housing 301, and a damping force adjusting valve 18, which is provided in a damping force adjusting passage VP, through which the expansion-side chamber R1 and the reservoir R are connected, including the annular passage P and the separating passage 44, and which resists a fluid flow passing through the damping force adjusting passage VP.

[0073] The following section describes in detail each part of the SA3 shock absorber of the fourth modification, which is equipped with vehicle height adjustment. The cylinder 1 contains the opening 1a provided near its upper end, the annular rod guide 7 supporting the piston rod 3 and inserted through its inner circumference is attached at the upper end, and the valve housing 6 is attached at the lower end. Furthermore, the housing 301, acting as a separating element with an opening 301a through which the cylinder 1 is inserted, is attached to the outer circumferential surface of the intermediate section of the cylinder 1.

[0074] In the rod guide 7, the outer diameter of the outer circumference is reduced in two stages at the lower end, with the smallest outer diameter section at the lower end fitting into the opening at the upper end of the cylinder 1 and the next smaller outer diameter section fitting into the opening at the upper end of the intermediate tube 43 that surrounds the housing 301 of the cylinder 1 at the top.

[0075] The lower end of the intermediate tube 43 is attached to an annular raised section 301b that protrudes from the upper end of the housing 301 and is fastened to the cylinder 1 by being sandwiched between the rod guide 7 attached to the upper end of the cylinder 1 and the housing 301.

[0076] The outer tube 5 contains the upper tube 5a and the lower tube 5b. The rod guide 7 described above is attached to the upper end of the upper tube 5a, and the upper end of the upper tube 5a is closed by the rod guide 7. Furthermore, the lower end of the upper tube 5a is firmly connected to the upper end of the housing 301 by welding or the like. The lower end of the lower tube 5b contains the bracket 13a, which can be attached to a vehicle (not shown), and is closed by the bottom cap 13, which abuts the lower end of the valve housing 6. The upper end of the lower tube 5b is connected to the lower end of the housing 30 and surrounds the housing 301 of the cylinder 1 downwards.

[0077] Therefore, the cylinder 1, the housing 301 and the valve housing 6 are arranged in a sandwich-like manner between the bottom cap 13 closing the lower end of the outer tube 5 and the rod guide 7 and are fixed immovably inside the outer tube 5, and the intermediate tube 43 is also arranged in a sandwich-like manner between the housing 301 and the rod guide 7 and is fixed immovably inside the outer tube 5.

[0078] When cylinder 1, intermediate tube 43, housing 301, and outer tube 5 are assembled in this manner, the annular passage P is formed between the housing 301 of cylinder 1 and the intermediate tube 43, the reservoir T, which stores fluid, is formed in the annular gap between the intermediate tube 43 and the upper tube 5a, and the reservoir R is formed in the annular gap between the housing 301 of cylinder 1 and the lower tube 5b. Therefore, the housing 301, acting as a partition, divides the interior of the SA3 shock absorber, which is equipped with vehicle height adjustment, into the reservoir T and the reservoir R.

[0079] The valve housing 6 is attached to the lower ends of the cylinder 1 to seal them. Furthermore, the valve housing 6 separates the compression-side chamber R2 inside the cylinder 1 from the reservoir R and includes an intake passage 17 with a passage 17a through which the compression-side chamber R2 and the reservoir R are connected, as well as a check valve 17b that allows fluid flow only from the reservoir R to the compression-side chamber R2. As described above, in the shock absorber SA3 of the present embodiment, which is equipped with vehicle height adjustment, the fluid chamber RL in the reservoir R is connected to the compression-side chamber R2 via the intake passage 17.

[0080] Furthermore, the annular passage P between cylinder 1 and intermediate tube 43 is connected to the expansion-side chamber R1 in cylinder 1 via the opening 1a provided in cylinder 1, and to the reservoir R via the separating passage 44 provided in housing 301. Therefore, the expansion-side chamber R1 and the reservoir R are connected to each other via the opening 1a, the annular passage P between cylinder 1 and intermediate tube 43, and the separating passage 44, and the opening 1a, the annular passage P, and the separating passage 44 form the damping force adjustment passage VP. The annular passage P can be connected to the expansion-side chamber R1 by providing a passage in the rod guide 7 instead of the opening 1a in cylinder 1.In this way, the damping force adjustment passage VP can be designed so that it contains a passage provided in the rod guide 7 instead of the opening 1a.

[0081] As in Fig. As shown in Figure 7, the damping force adjustment valve 18 is installed in the center of the separating passage 44, which is provided in the housing 301 that forms part of the damping force adjustment passage VP. In the present embodiment, the damping force adjustment valve 18 is a solenoid valve comprising: a valve body 18a, which is provided in the housing 301 and installed in the center of the separating passage 44; a spring 18b, which biases the valve body 18a in a direction in which the valve body 18a is closed; a solenoid 18c, which, when energized, can generate a thrust in a direction in which the valve body 18a is opened against the spring 18b; and a control bushing 18d, which causes the pressure of the expansion-side chamber R1 to act with respect to the valve body 18a in the valve opening direction.The damping force-adjusting valve 18 can perform a height adjustment of a valve opening pressure by adjusting the amount of current supplied to the solenoid 18c, maximize the resistance to fluid flow at maximum valve opening pressure during power interruption, maximize the resistance to fluid flow at minimum valve opening pressure when the amount of current supplied to the solenoid 18c is maximized, and adjust the valve opening pressure between maximum and minimum according to the amount of current. The damping force-adjusting valve 18 can be a solenoid valve that minimizes the valve opening pressure during power interruption and maximizes the valve opening pressure when the amount of current supplied to the solenoid is maximized.The damping force adjusting valve 18 can be provided in the damping force adjusting passage VP and thus, in addition to the separating passage 44 in the housing 301, can be provided in the annular passage P or the rod guide 7.

[0082] The housing 301 then contains internally the hydraulic circuit C, the pump body 31a of the pump 31 described later, and other components besides the solenoid 18c of the damping force adjusting valve 18, and includes, as in Fig. Figure 1 shows the opening 301a into which the cylinder 1 is inserted, and the annular raised section 301b, which projects from its upper end around the opening 301a and is attached to the inner circumferential surface of the lower end of the intermediate tube 43. The housing 301 is then attached to the outer circumferential surface of the cylinder 1 and connected to the upper tube 5a and the lower tube 5b of the outer tube 5 by welding or the like. In addition to the hydraulic circuit C, the housing 301 contains the separating passage 44, which forms an upper end opening of the annular raised section 301b of the housing 301. Fig. 7 and leads to the lower end of the housing 301. When the separating passage 44 is attached to the outer circumferential surface of the cylinder 1 and the annular raised section 301b is fitted to the lower end of the intermediate tube 43 in Fig.The separating passage 44, which is attached to the outer tube 5, faces the annular passage P between the cylinder 1 and the intermediate tube 43. In this way, the separating passage 44 is connected to the annular passage P between the cylinder 1 and the intermediate tube 43 to form part of the damping force adjustment passage VP.

[0083] In this way, the shock absorber SA3, equipped with vehicle height adjustment, comprises: a cylinder 1; a piston 2, which is inserted into the cylinder 1 so that it is movable in the axial direction and which divides the interior of the cylinder 1 into a fluid-filled expansion-side chamber R1 and a compression-side chamber R2; a piston rod 3, which is inserted into the expansion-side chamber R1, is movable in the axial direction with respect to the cylinder 1 and is connected to the piston 2; a housing 301 as a separating element, which is attached to an outer circumference of an intermediate section of the cylinder 1; an intermediate tube 43, which is inserted between the cylinder 1 and the outer tube 5 and surrounds the housing 301 of the cylinder 1 at the top and forms an annular passage P, which is connected to the expansion-side chamber R1 between the cylinder 1 and the intermediate tube 43;an upper tube 5a, which surrounds the outer circumference of the intermediate tube 43 and forms a container T, which stores liquid between the intermediate tube 43 and the upper tube 5a; a lower tube 5b, which surrounds the bottom of the housing 301 of the cylinder 1 and forms a reservoir R, which is connected to the compression-side chamber R2 between the lower tube 5b and the cylinder 1; a pump 31, which is provided in the housing 30 and supplies liquid to and from the cylinder 1 via the reservoir R; a separating passage 44, which is provided in the housing 301 and through which an annular passage P and the reservoir R are connected;and a damping force adjustment valve 18, which is provided in a damping force adjustment passage VP, with which the expansion-side chamber R1 and the reservoir R are connected, including the annular passage P and the separating passage 44, and which resists a fluid flow flowing through the damping force adjustment passage VP.

[0084] In the SA3 shock absorber of the fourth modification, equipped with vehicle height adjustment, since the pump 31 is provided in the housing (separating element) 301, which divides the interior of the outer tube 5 into the reservoir T and the reservoir R, and the damping force adjusting valve 18 is provided in the damping force adjusting passage VP, which does not affect the volume of the reservoir R, the pump 31 and the damping force adjusting valve 18 can be mounted on the shock absorber base body D above the intermediate section with respect to the shock absorber base body D, and since the intermediate tube 43 only surrounds the housing (separating element) 301 of the cylinder 1 at the top and the reservoir R is not arranged between the cylinder 1 and the lower tube 5b, the volume of the reservoir R can be kept large.Therefore, according to the SA3 shock absorber of the fourth modification, which is equipped with a vehicle height adjustment, a complete reduction in size is possible, even if the pump 31 and the damping force adjusting valve 18 are included, an increase in the outer diameter of the lower tube 5b can be avoided and the overall length of the intermediate tube 43 can be reduced, so that the costs can also be reduced.

[0085] It is evident from the above that, according to the SA3 shock absorber of the fourth modification, which is equipped with a vehicle height adjustment, a reduction and securing of the volume of the reservoir R as well as a reduction in costs are possible, while both the adjustment of the vehicle height and the adjustment of the damping force are possible.

[0086] Furthermore, in the SA3 shock absorber of the fourth modification, which is equipped with a vehicle height adjustment, the pump 31 and the damping force adjusting valve 18 are provided in the housing (separating element) 301, which divides the inside of the outer tube 5 into the container T and the reservoir R, so that the pump 31 and the damping force adjusting valve 18 can be concentrated on one part with respect to the main body D of the shock absorber, which simplifies manufacturing and further reduces costs.

[0087] Furthermore, the SA3 shock absorber of the fourth modification, equipped with vehicle height adjustment, includes a bladder (elastic partition) 14, which is housed in the reservoir R and divides the interior of the reservoir R into a gas chamber RG and a liquid chamber connected to the compression-side chamber R2. According to the SA3 shock absorber with vehicle height adjustment of the fourth modification, since the reservoir R is not facing the intermediate tube 43 and the width of the reservoir R can be increased in the radial direction, the volume in the reservoir R can be easily protected, even when the interior of the reservoir R is divided by its installation in the bladder (elastic partition) 14, and the ingress of gas in the reservoir R into the cylinder 1 can be prevented.

[0088] Although the preferred embodiment of the present invention has been described in detail above, modifications, variations and changes may be made without departing from the scope of the claims. Reference symbol list 1 cylinder 2 pistons 3 Piston rod 5 Outer pipe 9 Rectifier passage 17 Intake passage 18 Damping force adjusting valve 18a Valve body 18c Solenoid 21 Lower spring seat 22 Drive cover 30, 301 Housing (separating element) 30c Spring seat mounting section 31 Pump 31a Pump body 31b Drive 32 Feed pass 33 Outlet passage 36 Operating check valve D Shock absorber base body P Pump unit R Reservoir R1 Expansion-side chamber R2 Compression-side chamber SA, SA1, SA2, SA3 shock absorbers equipped with vehicle height adjustment T container VP damping force adjustment range QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2000-127734 A [0003, 0004, 0006] JP 2015-137676 A [0004, 0006]

Claims

[1] Shock absorber equipped with vehicle height adjustment (SA; SA1; SA2; SA3), comprising: a shock absorber body (D) comprising a cylinder (1), a piston (2) inserted into the cylinder (1) in such a way that it is movable in an axial direction and divides the interior of the cylinder (1) into an expansion-side chamber (R1) and a compression-side chamber (R2) filled with a fluid, a piston rod (3) inserted into the expansion-side chamber (R1), movable in the axial direction relative to the cylinder (1) and connected to the piston (2), and an outer tube (5) surrounding the cylinder (1); a separating element (30; 301) that divides the interior of the outer tube (5) into a container (T) and a reservoir (R), the container (T) stores liquid, the reservoir (R) is connected to the compression-side chamber (R2) to compensate for a volume of the piston rod (3) entering and exiting the interior of the cylinder (1); a pump (31) provided at the separating element (30; 301) which supplies the liquid through the reservoir (R) into the interior of the cylinder (1) and discharges it from there; and a damping force adjusting valve (18) which is provided on the separating element (30; 301) and is designed to adjust a damping force during an expansion and a compression of the shock absorber body (D). [2] The shock absorber (SA; SA1; SA2; SA3) equipped with vehicle height adjustment according to claim 1, wherein the separating element (30; 301) contains: a feed passage (32) through which the container (T) and the reservoir (R) are connected and at which the pump (31) is provided, an outlet passage (33) through which the container (T) and the reservoir (R) are connected, a service check valve (36) which is provided in the outlet passage (33) and which only allows a fluid flow from the reservoir (R) to the container (T) when the valve is open, and a damping force adjustment passage (VP) through which fluid flows during expansion and compression of the shock absorber body (D) and at which the damping force adjustment valve (18) is provided, and The pump (31) is a bidirectional delivery pump which, when rotating forward, delivers liquid from the container (T) to the reservoir (R) and, when rotating backward, applies a control pressure to the operating check valve (36) to open it. [3] The shock absorber (SA; SA1; SA2; SA3) equipped with vehicle height adjustment according to claim 1, wherein The pump (31) includes: a pump body (31a) which is provided in the feed passage (32) and a drive (31b) which drives the pump body (31a), The damping force adjustment valve (18) comprises: a valve body (18a) provided in the damping force adjustment passage (VP), and a solenoid (18c) that exerts a thrust on the valve body (18a), and the drive (31b) and the solenoid (18c) are attached to the separating element (30; 301), the separating element (30; 301) is sandwiched between the drive (31b) and the solenoid (18c) in a vertical direction, and in the vertical direction both are arranged in overlapping positions relative to the separating element (30; 301). [4] The shock absorber (SA; SA1; SA2; SA3) equipped with vehicle height adjustment according to claim 1, comprising a support spring (S) arranged between the piston rod (3) and the separating element (30; 301), wherein the pump (31) contains: a pump body (31a) which is provided on the separating element (30; 301) and supplies and discharges fluid through the reservoir (R) into the cylinder (1), and a drive (31b) which is designed to drive the pump body (31a) and is attached to the separating element (30; 301) on the side opposite the piston rod (3). [5] The shock absorber (SA; SA1; SA2; SA3) equipped with vehicle height adjustment according to claim 1, wherein the separating element (30; 301) is attached to an outer circumference of the cylinder (1), The shock absorber equipped with vehicle height adjustment (SA; SA1; SA2; SA3) includes: an intermediate tube that is inserted between the cylinder (1) and the outer tube (5), surrounds the cylinder (1) above the separating element (30; 301) and forms an annular passage that is connected to the expansion-side chamber (R1) between the intermediate tube and the cylinder (1), wherein the outer tube (5) contains: an upper tube that surrounds the outer circumference of the intermediate tube and forms a container (T) for liquid storage between the upper tube and the intermediate tube, and a lower tube that surrounds the area below the separating element (30; 301) on the cylinder (1) and forms a reservoir (R) that lies between the cylinder (1) and the lower tube and is connected to the compression-side chamber (R2), and the separating element (30; 301) contains: a separation passage through which the annular passage and the reservoir (R) are connected, and The damping force adjustment valve (18) is provided in a damping force adjustment passage (VP) through which the expansion-side chamber (R1) and the reservoir (R) are connected; the damping force adjustment passage (VP) contains the annular passage and the separating passage. [6] The shock absorber (SA; SA1; SA2; SA3) equipped with vehicle height adjustment according to claim 2, wherein the shock absorber body (D) comprises: an intake passage (17) which only allows a fluid flow from the reservoir (R) to the compression-side chamber (R2), and a rectifier passage (9) which only allows fluid flow from the compression-side chamber (R2) to the expansion-side chamber (R1), and The expansion-side chamber (R1) and the reservoir (R) are connected to each other via the damping force adjustment passage (VP). [7] The shock absorber (SA; SA1; SA2; SA3) equipped with vehicle height adjustment according to claim 4, comprising a lower spring seat (21) which is attached to the separating element (30; 301) and supports a cylinder-side end of the spring. [8] The shock absorber (SA; SA1; SA2; SA3) equipped with vehicle height adjustment according to claim 4, comprising a tubular drive cover (22) attached to the separating element (30; 301) and surrounding the outer circumference of the drive (31b). [9] The shock absorber (SA; SA1; SA2; SA3) equipped with vehicle height adjustment according to claim 4, comprising a damping force adjusting valve (18) which is provided on the separating element (30; 301) and is configured to adjust a damping force during an expansion and compression of the shock absorber body (D), wherein The damping force adjustment valve (18) includes: a valve body (18a) provided in the damping force adjustment passage (VP), and a solenoid (18c) that exerts thrust on the valve body (18a), and the solenoid (18c) is attached to the separating element (30; 301) on the opposite side of the piston rod (30; 301). [10] The shock absorber (SA; SA1; SA2; SA3) equipped with vehicle height adjustment according to claim 7, wherein the separating element (30; 301) includes a spring seat mounting section (30c) that surrounds the outer tube (5) and in which the lower spring seat (21) is seated, and The pump (31) is attached to an outer circumferential side of the spring seat mounting section (30c) of the separating element (30; 301). [11] The shock absorber (SA; SA1; SA2; SA3) equipped with vehicle height adjustment according to claim 5, comprising an elastic partition which is received in the reservoir (R) and divides the interior of the reservoir (R) into a gas chamber and a liquid chamber which is connected to the compression-side chamber (R2).

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