Suspension with vehicle height adjustment function

Abstract

The buffer (D1) with vehicle height adjustment function of the present invention comprises: a buffer body (1) having a cylinder (2) filled with liquid, a piston (3) dividing the cylinder (2) into an extension side chamber (R1) and a compression side chamber (R2), and a piston rod (4) connected to the piston (3); a suspension spring (S) applying force to the buffer body (1) in the extension direction; a liquid reservoir (R) storing liquid; and a shock absorber circuit (C1) connected to the extension side chamber (R1). The system includes a compression chamber (R2) and a reservoir chamber (R) connected to generate a damping force in the buffer body (1) when it extends or retracts; a pump (P) that can draw liquid from the reservoir chamber (R) and discharge it; and a switching valve (V1) located between the buffer body (1), the shock absorber circuit (C1), and the pump (P), which can switch between a shock absorber mode that connects the buffer body (1) to the shock absorber circuit (C1) to generate a damping force in the buffer body (1) and a vehicle height adjustment mode that connects the buffer body (1) to the pump (P).

Description

Technical Field

[0001] This invention relates to a buffer with vehicle height adjustment function. Background Technology

[0002] As a buffer with vehicle height adjustment function, for example, as disclosed in JP2015-117812A, it comprises: a buffer body having a housing and a piston rod axially movable and inserted into the housing, generating a damping force when the piston rod moves relative to the housing; an annular spring support slidably mounted on the outer periphery of the housing; a rod-side spring support mounted on the front end of the piston rod; a suspension spring inserted between the spring support and the rod-side spring support, applying force to the buffer body in the extension direction; and a vehicle height adjustment device mounted on the outer periphery of the housing, driving the spring support axially. The buffer with vehicle height adjustment function is inserted between the body of the motorized two-wheeled vehicle and the swing arm.

[0003] Specifically, the vehicle height adjustment device includes: a hydraulic jack, which is installed on the outer periphery of the housing and drives the spring support axially; a pump, which supplies pressurized oil to the hydraulic jack via a hose; and a reservoir, which stores hydraulic oil.

[0004] Furthermore, when the vehicle height adjustment device's operating pump discharges pressurized oil from the jack chamber inside the hydraulic jack to the reservoir, the hydraulic jack contracts, causing the spring support to move along the outer periphery of the housing towards the opposite side of the piston rod. Additionally, when the vehicle height adjustment device's operating pump supplies pressurized oil from the reservoir to the jack chamber, the hydraulic jack extends, causing the spring support to move along the outer periphery of the housing towards the piston rod side.

[0005] Therefore, the damper with vehicle height adjustment function changes the position of the spring support relative to the shell by driving the hydraulic jack, which can adjust the vehicle height of the motorized two-wheeler. So when the motorized two-wheeler is parked, the vehicle height can be lowered to improve the leg support stability of the passenger.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2015-117812 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] As mentioned earlier, traditional shock absorbers with vehicle height adjustment function adjust the vehicle height through a vehicle height adjustment device installed on the outer periphery of the shock absorber body. The shock absorber body has a separate liquid storage chamber. In addition, the vehicle height adjustment device also has a hydraulic jack and a liquid storage tank. Therefore, the overall size is large, and there are problems with vehicle loadability.

[0011] Therefore, the purpose of this invention is to provide a buffer with vehicle height adjustment function that is small in size.

[0012] Solution for solving the problem

[0013] To achieve the aforementioned objective, the buffer with vehicle height adjustment function in the solution of the present invention comprises: a buffer body having a cylinder filled with liquid, a piston movably inserted into the cylinder and dividing the cylinder into an extension side chamber and a compression side chamber, and a piston rod movably inserted into the cylinder and connected to the piston; a suspension spring applying force to the buffer body along the extension direction; a reservoir chamber storing liquid; a shock absorber circuit connected to the extension side chamber, the compression side chamber, and the reservoir chamber, generating a damping force in the buffer body when it extends or retracts; a pump capable of drawing liquid from the reservoir chamber and discharging it; and a switching valve disposed between the buffer body, the shock absorber circuit, and the pump, capable of switching between a shock absorber mode that connects the buffer body to the shock absorber circuit to generate a damping force in the buffer body, and a vehicle height adjustment mode that connects the buffer body to the pump.

[0014] The damper with vehicle height adjustment function, constructed in this way, allows for selective activation of the shock absorber circuit and pump via a switching valve. Therefore, the reservoir chamber used to supply excess or insufficient fluid to the cylinder when the damper body generates damping force can be used as a reservoir to store fluid supplied to the damper body during vehicle height adjustment. Furthermore, the damper with vehicle height adjustment function, constructed in this way, allows the pump to be driven to supply fluid to the damper body, causing it to extend, retract, or expand / contract, thus eliminating the need for jacks to drive the suspension spring supports. Therefore, the damper with vehicle height adjustment function achieves miniaturization despite possessing this feature. Attached Figure Description

[0015] Figure 1 This is a diagram showing the buffer with vehicle height adjustment function in the first embodiment.

[0016] Figure 2 This is a diagram showing a buffer with vehicle height adjustment function in a first variation of the first embodiment.

[0017] Figure 3 This is a diagram showing a buffer with vehicle height adjustment function in a second variation of the first embodiment.

[0018] Figure 4 This is a diagram showing the buffer with vehicle height adjustment function in the second embodiment.

[0019] Figure 5 This is a diagram showing a buffer with vehicle height adjustment function in a first variation of the second embodiment.

[0020] Figure 6 This is a diagram showing a buffer with vehicle height adjustment function in a second variation of the second embodiment.

[0021] Figure 7 This is a diagram showing the buffer with vehicle height adjustment function in the third embodiment.

[0022] Figure 8 This is a diagram showing the structure of the cover in a specific example of a buffer with vehicle height adjustment function according to the third embodiment.

[0023] Figure 9 This is a longitudinal cross-sectional view of a specific example of a buffer with vehicle height adjustment function in the third embodiment. Detailed Implementation

[0024] The present invention will now be described based on the embodiments shown in the figures. In the buffers with vehicle height adjustment function in each embodiment, components and members with common symbols have the same configuration. Therefore, to avoid repetition, detailed descriptions of configurations already provided in the description of the buffer with vehicle height adjustment function in one embodiment will be omitted in the descriptions of the buffers with vehicle height adjustment function in other embodiments.

[0025] <First Implementation Method>

[0026] like Figure 1 As shown, the buffer D1 with vehicle height adjustment function in the first embodiment includes: a buffer body 1; a suspension spring S that applies force to the buffer body 1 along its extension direction; a liquid reservoir R that stores liquid; a shock absorber circuit C1; a pump P; and a switching valve V1. The buffer D1 is inserted between the body and axle of a vehicle (not shown). Furthermore, the vehicle using the buffers with vehicle height adjustment function in each embodiment is not limited to motorized two-wheeled vehicles, but can also be a car or other vehicles.

[0027] First, the buffer body 1 will be described. The buffer body 1 in this embodiment includes: a cylinder 2 filled with liquid; a piston 3 movably inserted into the cylinder 2, dividing the cylinder 2 into an extension side chamber R1 and a compression side chamber R2; a piston rod 4 movably inserted into the cylinder 2 and connected to the piston 3; and a housing 5, which is cylindrical, covers the outer periphery of the cylinder 2, and forms an annular gap 6 between the housing and the cylinder 2 that communicates with the extension side chamber R1.

[0028] Cylinder 2 is cylindrical, and its interior is as described above. Piston 3 is axially movable and inserted into cylinder 2. Figure 1 The left side is separated by an elongated lateral chamber R1. Figure 1 A compression chamber R2 is separated on the right side. The extension chamber R1 and the compression chamber R2 are filled with, for example, hydraulic oil as the working fluid. Alternatively, besides hydraulic oil, liquids such as water or aqueous solutions can also be used as the working fluid. Cylinder 2 Figure 1 A flange 2b is provided at the right end.

[0029] Furthermore, a piston rod 4 connected to the piston 3 is axially movable inside the cylinder 2. The cylinder 2 is then housed within a cylindrical outer casing 5 disposed on its outer periphery, with an annular gap 6 formed between the cylinder 2 and the casing 5.

[0030] Cylinder 2 and housing 5 Figure 1 An annular guide 7 is installed at the left-hand end, i.e., the head end, and the piston rod 4 protrudes outward from the cylinder 2 through the inner circumference of the guide 7. The guide 7 includes: a sealing ring 7a, which slides in contact with the outer circumference of the piston rod 4; and a bushing 7b, which is cylindrical and slides in contact with the outer circumference of the piston rod 4. The guide 7 seals the outer circumference of the piston rod 4 and guides it to move axially relative to the piston rod 4 in the cylinder 2.

[0031] In addition, cylinder 2 and housing 5 Figure 1 A cover 8 is installed at the right-hand end, i.e., the bottom end, to seal the bottom ends of the cylinder 2 and the housing 5. Furthermore, the openings at both ends of the cylinder 2 and the housing 5 are sealed by the guide 7 and the cover 8, and the inside of the cylinder 2 and the two ends of the annular gap 6 between the cylinder 2 and the housing 5 are sealed.

[0032] The cover 8 is a bottomed cylindrical shape, with the outer periphery of the flange 2b of the cylinder 2 fitted into its inner circumference. Furthermore, a threaded portion 5b provided on the outer periphery of the outer shell 5 is screwed onto the inner circumference of the cover 8. The flange 2b of the cylinder 2 is clamped on the bottom of the outer shell 5 and the cover 8, and the cylinder 2 is fixed to the cover 8. This structure fastening the cylinder 2 and the cover 8 of the outer shell 5 is only one example; other fastening structures can also be used. In addition, the cover 8 is provided with: a port 8a, which opens from the side and communicates with the annular gap 6; and a port 8b, which also opens from the side and communicates with the compression chamber R2. Ports 8a and 8b are respectively connected to the shock absorber circuit C1. Moreover, a hole 2a is provided near the head end of the cylinder 2 to communicate with the elongation chamber R1 and the annular gap 6. Therefore, the elongation chamber R1 is connected to the shock absorber circuit C1 via the annular gap 6 and port 8a, and the compression chamber R2 is connected to the shock absorber circuit C1 via port 8b. Furthermore, the cover 8 has a bottom spring support 8c, which is formed by an annular stepped portion on the outer periphery of the cylinder side relative to the openings of ports 8a and 8b.

[0033] The piston 3 is provided with: a pressure relief channel 9, which connects the elongation side chamber R1 and the compression side chamber R2; and a pressure reducing valve 10, which switches the pressure relief channel 9 on and off. When the pressure in the elongation side chamber R1 exceeds the pressure in the compression side chamber R2, and the pressure difference between the two reaches the valve opening pressure, the pressure reducing valve 10 opens, allowing only hydraulic oil to flow from the elongation side chamber R1 to the compression side chamber R2.

[0034] Piston rod 4 Figure 1 The left-hand end, i.e. the front end, is equipped with a bracket 11 for mounting the piston rod 4 to the vehicle, and a head-side spring support 12 is mounted via the bracket 11. This head-side spring support 12 cannot move axially. Alternatively, the head-side spring support 12 can also be directly mounted on the piston rod 4.

[0035] Furthermore, a suspension spring S is inserted between the head-side spring support 12 and the bottom-side spring support 8c formed on the cover 8. The suspension spring S is inserted between the head-side spring support 12 and the bottom-side spring support 8c in a compressed state, and always applies force in the direction that causes the piston rod 4 to protrude outward from the cylinder 2. That is, the suspension spring S applies force to the buffer body 1 in the extension direction.

[0036] In the buffer D1 with vehicle height adjustment function of this embodiment, the reservoir R is not shown in the figure. It is an accumulator, which is internally divided by a diaphragm into a liquid chamber filled with hydraulic oil and a gas chamber sealed with gas. The hydraulic oil in the liquid chamber is pressurized by the gas pressure in the gas chamber. Alternatively, the reservoir R may only store hydraulic oil without pressurizing the liquid chamber. In addition, the separator between the liquid chamber and the gas chamber in the reservoir R may be a free piston or a bellows, in addition to a diaphragm.

[0037] Next, the shock absorber circuit C1 will be described. The shock absorber circuit C1 includes: a first channel 13, one end of which is connected to the extension-side chamber R1; a second channel 14, which connects the other end of the first channel 13 to the reservoir R; a third channel 15, which connects the connection point between the first channel 13 and the second channel 14, i.e., the first connection point J1, to the compression-side chamber R2; a first extension-side damping valve 16, which is disposed on the first channel 13 and applies resistance to the flow of hydraulic oil from the extension-side chamber R1 to the first connection point J1; and a first extension-side stop valve. The first extension-side check valve 17 and the first extension-side damping valve are connected in parallel on the first channel 13 and only allow hydraulic oil to flow from the first connection point J1 to the extension-side chamber R1; the first compression-side damping valve 18 is connected on the second channel 14 and applies resistance to the flow of hydraulic oil from the first connection point J1 to the reservoir R; the first compression-side check valve 19 is connected in parallel with the first compression-side damping valve 18 on the second channel 14 and only allows hydraulic oil to flow from the reservoir R to the first connection point J1.

[0038] As previously described, one end of the first channel 13 is connected to the elongation chamber R1, and the other end is connected to the second channel 14. Furthermore, one end of the second channel 14 is connected to the first channel 13, and the other end is connected to the reservoir R. Thus, the first channel 13 and the second channel 14 are connected in series, and the elongation chamber R1 is connected to the reservoir R via the first channel 13 and the second channel 14. Additionally, one end of the third channel 15 is connected to the compression chamber R2, and the other end is connected to the first connection point J1 between the first channel 13 and the second channel 14. Therefore, the elongation chamber R1 is connected to the compression chamber R2 via the first channel 13 and the third channel 15, and the compression chamber R2 is connected to the reservoir R via the third channel 15 and the second channel 14.

[0039] In the buffer D1 with vehicle height adjustment function of this embodiment, the first extension-side damping valve 16 is a damping valve that only allows hydraulic oil to flow from the extension-side chamber R1 through the first channel 13 to the first connection point J1 and applies resistance to the flow of hydraulic oil. For example, it is a vane valve or a lift valve. Alternatively, the first extension-side damping valve 16 can also be a valve that allows bidirectional flow, such as a throttle or a choke. Furthermore, the first extension-side check valve 17 is connected in parallel with the first extension-side damping valve on the first channel 13, allowing hydraulic oil to flow from the first connection point J1 through the first channel 13 to the extension-side chamber R1, and preventing reverse flow of hydraulic oil. Therefore, when hydraulic oil flows from the extension-side chamber R1 through the first channel 13 to the first connection point J1, the hydraulic oil passes through the first extension-side damping valve 16; conversely, when hydraulic oil flows from the first connection point J1 through the first channel 13 to the extension-side chamber R1, the hydraulic oil passes through the first extension-side check valve 17.

[0040] In the buffer D1 with vehicle height adjustment function of this embodiment, the first compression-side damping valve 18 is a damping valve that only allows hydraulic oil to flow from the first connection point J1 through the second channel 14 to the reservoir R and applies resistance to the flow of hydraulic oil. For example, it is a vane valve or a lift valve. Alternatively, the first compression-side damping valve 18 can also be a valve that allows bidirectional flow, such as a throttle or a choke. Furthermore, the first compression-side check valve 19 is connected in parallel with the first compression-side damping valve 18 on the second channel 14, allowing hydraulic oil to flow from the reservoir R through the second channel 14 to the first connection point J1 and preventing reverse flow of hydraulic oil. Therefore, when hydraulic oil flows from the first connection point J1 through the second channel 14 to the reservoir R, the hydraulic oil passes through the first compression-side damping valve 18; conversely, when hydraulic oil flows from the reservoir R through the second channel 14 to the first connection point J1, the hydraulic oil passes through the first compression-side check valve 19.

[0041] Next, pump P is a one-way pump, which is installed on pump channel 20, one end of which is connected to reservoir R and the other end of which is connected to switching valve V1. When driven by motor 21, it draws in hydraulic oil from reservoir R and discharges it to switching valve V1. Alternatively, pump P can be a gear pump, but it can also be a piston pump, screw pump, or other types of pumps. Furthermore, pump channel 20 is equipped with a pump channel check valve 22, which only allows hydraulic oil to flow from pump P through pump channel 20 to switching valve V1, preventing hydraulic oil from flowing back from switching valve V1 to pump P.

[0042] The switching valve V1 is a two-position three-way solenoid switching valve with three ports a, t, and p. Ports a and t are connected to the middle of the first channel 13, and are positioned on the extension side chamber side relative to the first extension-side damping valve 16 and the first extension-side check valve 17. Port p is connected to the other end of the pump channel 20. Specifically, the switching valve V1 includes: a valve body 23, which has a first position 23a and a second position 23b. The first position 23a connects port a and port t to connect the first channel 13 and closes port p to cut off the other end of the pump channel 20. The second position 23b closes port t to cut off the first channel 13 and connects port a and port p to connect the pump channel 20 to the extension-side chamber R1; a spring 24, which applies force to the valve body 23 to select the first position 23a; and a solenoid 25, which, when energized, counteracts the force of the spring 24 to switch the valve body 23 to the second position 23b. Therefore, when the solenoid 25 is not energized and the switching valve V1 is selected in the first position 23a, the pump channel 20 is cut off, the damper body 1 is connected to the shock absorber circuit C1 via the first channel 13, the shock absorber circuit C1 is active, and the damper D1 with vehicle height adjustment function is in shock absorber mode. On the other hand, when the solenoid 25 is energized and the switching valve V1 is selected in the second position 23b, the first channel 13 is cut off, the pump channel 20 is connected to the extension side chamber R1, the pump P is active, and the damper D1 with vehicle height adjustment function is in vehicle height adjustment mode. In this way, the switching valve V1 can switch the damper D1 with vehicle height adjustment function to either the shock absorber mode that only activates the shock absorber circuit C1 or the vehicle height adjustment mode that activates the pump P.

[0043] The buffer D1 with vehicle height adjustment function in the first embodiment is configured as described above, and its operation will be explained below. First, the operation when the switching valve V1 selects the first position 23a to put the buffer D1 with vehicle height adjustment function into shock absorber mode will be explained.

[0044] In the shock absorber mode, the extension side chamber R1 is connected to the shock absorber circuit C1 via the first channel 13 through the switching valve V1, and then connected to the compression side chamber R2 and the liquid storage chamber R via the shock absorber circuit C1. However, on the other hand, the pump channel 20 is cut off, and the connection between the extension side chamber R1 and the pump P is disconnected.

[0045] Furthermore, when the buffer body 1 extends due to external force, the piston 3 inside the cylinder 2 moves towards... Figure 1The piston moves to the left, compressing the elongation chamber R1 and expanding the compression chamber R2. As the piston 3 moves, hydraulic oil ejected from the elongation chamber R1 moves through the first elongation-side damping valve 16 in the first channel 13 and then through the third channel 15 to the expanded compression chamber R2. When the buffer body 1 extends, the piston rod 4 retracts from the cylinder 2. Therefore, the amount of hydraulic oil moving from the elongation chamber R1 to the compression chamber R2 is insufficient to fill the expanded volume of the compression chamber R2, resulting in insufficient hydraulic oil in the compression chamber R2. This insufficient amount of hydraulic oil is the volume of the piston rod 4 retracting from the cylinder 2. This insufficient portion of hydraulic oil is supplied from the reservoir R through the first compression-side check valve 19 in the second channel 14 and then through the third channel 15 to the compression chamber R2. As mentioned above, when the buffer body 1 extends, the first extension-side damping valve 16 applies resistance to the flow of hydraulic oil moving from the extension-side chamber R1 to the compression-side chamber R2, so the pressure in the extension-side chamber R1 rises. However, on the other hand, the pressure in the compression-side chamber R2 is approximately equal to the pressure in the reservoir R. Therefore, the buffer D1 with vehicle height adjustment function generates an extension-side damping force that hinders the extension of the buffer body 1.

[0046] When the buffer body 1 contracts due to external force, the piston 3 inside the cylinder 2 moves towards... Figure 1 The piston moves to the right, compressing the compression chamber R2 and expanding the extension chamber R1. As the piston 3 moves, the hydraulic oil ejected from the compression chamber R2 moves through the third channel 15 and the first extension-side check valve 17 of the first channel 13 into the expanded extension chamber R1. When the buffer body 1 retracts, the piston rod 4 enters the cylinder 2, so the amount of hydraulic oil ejected from the compression chamber R2 is excessive relative to the expanded volume in the extension chamber R1, the excess being the volume of the piston rod 4 entering the cylinder 2. This excess hydraulic oil is discharged from the compression chamber R2 through the third channel 15 and then through the first compression-side damping valve 18 of the second channel 14 into the reservoir R. As mentioned above, when the buffer body 1 retracts, the first compression-side damping valve 18 resists the flow of hydraulic oil moving from the compression chamber R2 to the reservoir R, so the pressure in the extension chamber R1 and the compression chamber R2 rises and becomes approximately equal. The piston 3 subjected to pressure from the compression chamber R2 has a larger pressure area than the piston 3 subjected to pressure from the extension chamber R1. The larger portion is the cross-sectional area of ​​the piston rod 4. Therefore, the buffer D1 with vehicle height adjustment function generates a compression-side damping force that hinders the contraction of the buffer body 1.

[0047] Therefore, when the damper D1 with vehicle height adjustment function is selected in shock absorber mode, when the damper body 1 is extended or retracted by external force, the damper D1 with vehicle height adjustment function generates a damping force that hinders the extension or retraction of the damper body 1.

[0048] Next, the operation of the damper D1 with vehicle height adjustment function in vehicle height adjustment mode when the switching valve V1 is selected to the second position 23b will be explained. When the switching valve V1 is selected to the second position 23b, the pump passage 20 is connected to the extension side chamber R1, the first passage 13 is cut off, and there is no hydraulic oil flowing from the switching valve V1 in the first passage 13 to the first connection point J1.

[0049] In this state, when the pump P is driven by the motor 21 to supply hydraulic oil from the reservoir R to the extension side chamber R1, the hydraulic oil will push the piston 3 towards... Figure 1 When pushed from the right, the buffer body 1 retracts. As the buffer body 1 retracts, the elongation chamber R1 expands, and the compression chamber R2 compresses, causing hydraulic oil to be ejected from the compression chamber R2. The ejected hydraulic oil is discharged into the reservoir R through the first compression-side damping valve 18 of the third channel 15 and the second channel 14.

[0050] Therefore, when the vehicle height adjustment function of the buffer D1 is selected in the vehicle height adjustment mode, the buffer D1 compresses the suspension spring S by driving the pump P, causing the buffer body 1 to contract and lower the vehicle height. The elastic force of the suspension spring S increases accordingly with the amount of compression of the suspension spring S, exerting force on the buffer body 1 along the extension direction, so the pressure in the extension side chamber R1 becomes high pressure. In addition, a pump channel check valve 22 is provided on the pump channel 20, preventing the hydraulic oil in the extension side chamber R1 from moving. Therefore, even if the driving pump P is stopped, the buffer body 1 will remain in a contracted state, and the vehicle height will remain in a lowered state. Furthermore, the buffer D1 with vehicle height adjustment function can adjust the amount of contraction of the buffer body 1 according to the amount of hydraulic oil supplied from the pump P. If a stroke sensor is provided to detect the extension and retraction displacement of the buffer body 1, the amount of contraction of the buffer body 1 can be determined. Therefore, the amount of contraction of the buffer body 1 can be monitored using the stroke sensor, and if the motor 21 is controlled, the amount of contraction of the buffer body 1 can be adjusted to a predetermined amount. Furthermore, for example, if the vehicle occupant can power on the motor 21, the pump P can be driven until the vehicle reaches the occupant's desired height, allowing the occupant to adjust the vehicle height.

[0051] Furthermore, when the buffer D1 with vehicle height adjustment function is in vehicle height adjustment mode, when the external force causing the buffer body 1 to extend in the retracted state is applied to the buffer body 1, and the pressure in the extension side chamber R1 reaches the preset upper limit pressure, the pressure reducing valve 10 opens, allowing hydraulic oil to move from the extension side chamber R1 to the compression side chamber R2. Therefore, when the buffer D1 with vehicle height adjustment function is in vehicle height adjustment mode, even if the buffer body 1 extends while the occupant is driving the vehicle, the pressure in the extension side chamber R1 will not be excessive, thus protecting the buffer D1 with vehicle height adjustment function.

[0052] Furthermore, after lowering the vehicle height by switching the damper D1 with vehicle height adjustment function to vehicle height adjustment mode, the switching valve V1 is switched from the second position 23b to the first position 23a, turning the damper D1 into shock absorber mode. In this mode, the extension chamber R1 is connected to the shock absorber circuit C1 via the first channel 13, the pump channel 20 is cut off, and the connection between the pump P and the extension chamber R1 is disconnected. As a result, the suspension spring S, compressed after the vehicle height decreases, causes the damper body 1 to extend. Hydraulic oil is then pushed out from the extension chamber R1, moving through the first extension damping valve 16 and the third channel 15 to the compression chamber R2. Simultaneously, the piston rod 4 exits the cylinder 2, and a corresponding amount of hydraulic oil moves from the reservoir R through the first compression check valve 19 and the third channel 15 to the compression chamber R2. The suspension spring S extends until its elastic force balances the load on the vehicle body, thus restoring the damper body 1 from the vehicle height-lowered state to its state before the decrease. Therefore, when the damper D1 with vehicle height adjustment function switches from vehicle height adjustment mode to shock absorber mode, it can return to the state before vehicle height adjustment using the elastic force of the suspension spring S. In addition, when the damper body 1 returns from the retracted state to the original state, the first extension side damping valve 16 applies resistance to the flow of hydraulic oil, so the extension speed of the damper body 1 is appropriately slowed down, so as not to cause discomfort to the passenger.

[0053] In the aforementioned situation, when the buffer D1 with vehicle height adjustment function is in vehicle height adjustment mode, the vehicle height is lowered by driving pump P. However, if you want to raise the vehicle height using vehicle height adjustment mode, as follows... Figure 2 The buffer D2 with vehicle height adjustment function in the first variation of the first embodiment shown can be configured as follows.

[0054] The buffer D2 with vehicle height adjustment function in the first variation of the first embodiment has a different setting position of the switching valve V1 compared to the buffer D1 with vehicle height adjustment function in the first embodiment.

[0055] In the buffer D1 with vehicle height adjustment function, the switching valve V1 is set in the middle of the first channel 13. By switching the switching valve V1, the connection between the extension side chamber R1 and the shock absorber circuit C1 and the connection between the extension side chamber R1 and the pump channel 20 can be selectively switched. However, if you want to raise the vehicle height in the vehicle height adjustment mode, as shown in the buffer D2 with vehicle height adjustment function, the switching valve V1 is set in the middle of the third channel 15. By switching the switching valve V1, the connection between the compression side chamber R2 and the shock absorber circuit C1 and the connection between the compression side chamber R2 and the pump channel 20 can be selectively switched.

[0056] Specifically, such as Figure 2 As shown, the ports a and t of the switching valve V1 are connected to the middle of the third channel 15, and the port p of the switching valve V1 is connected to the other end of the pump channel 20. That is, when the switching valve V1 is selected in the first position 23a, the ports a and t are connected to connect the third channel 15, the compression chamber R2 is connected to the shock absorber circuit C1, and the port p is closed to disconnect the pump P from the compression chamber R2. In addition, when the switching valve V1 is selected in the second position 23b, the port t is closed to cut off the third channel 15, disconnecting the compression chamber R2 from the shock absorber circuit C1, and the ports a and p are connected to connect the pump P to the compression chamber R2. Therefore, without energizing the solenoid 25, when the switching valve V1 is selected in the first position 23a, the pump channel 20 is cut off, the buffer body 1 is connected to the shock absorber circuit C1 via the third channel 15, the shock absorber circuit C1 is active, and the buffer D2 with vehicle height adjustment function is in shock absorber mode. On the other hand, when the solenoid 25 is energized and the switching valve V1 is selected to the second position 23b, the third channel 15 is cut off, the pump channel 20 is connected to the compression side chamber R2, the pump P is active, and the buffer D2 with vehicle height adjustment function is in vehicle height adjustment mode. In this way, even when the switching valve V1 is in the buffer D2 with vehicle height adjustment function in the first modification of the first embodiment, it can be switched to either the shock absorber mode that only activates the shock absorber circuit C1 or the vehicle height adjustment mode that activates the pump P. Furthermore, in the buffer D2 with vehicle height adjustment function in the first modification, a pressure reducing valve 101 is provided on the pressure relief channel 9 in the opposite direction to that of the buffer D1 with vehicle height adjustment function.

[0057] The buffer D2 with vehicle height adjustment function in the first variation of the first embodiment is configured as described above, and its operation will be explained below. First, the operation when the switching valve V1 selects the first position 23a to put the buffer D1 with vehicle height adjustment function into shock absorber mode will be explained.

[0058] In the shock absorber mode, the compression side chamber R2 is connected to the shock absorber circuit C1 via the third channel 15 through the switching valve V1, and then connected to the extension side chamber R1 and the reservoir chamber R via the shock absorber circuit C1. However, on the other hand, the pump channel 20 is cut off, and the connection between the compression side chamber R2 and the pump P is disconnected.

[0059] First, when the buffer body 1 extends due to external force, the piston 3 inside the cylinder 2 moves towards... Figure 1 The piston moves to the left, compressing the elongation chamber R1 and expanding the compression chamber R2. As the piston 3 moves, hydraulic oil ejected from the elongation chamber R1 moves through the first elongation-side damping valve 16 in the first channel 13 and then through the third channel 15 to the expanded compression chamber R2. When the buffer body 1 extends, the piston rod 4 retracts from the cylinder 2. Therefore, the amount of hydraulic oil moving from the elongation chamber R1 to the compression chamber R2 is insufficient to fill the expanded volume of the compression chamber R2, resulting in insufficient hydraulic oil in the compression chamber R2. This insufficient amount of hydraulic oil is the volume of the piston rod 4 retracting from the cylinder 2. This insufficient portion of hydraulic oil is supplied from the reservoir R through the first compression-side check valve 19 in the second channel 14 and then through the third channel 15 to the compression chamber R2. As mentioned above, when the buffer body 1 extends, the first extension-side damping valve 16 applies resistance to the flow of hydraulic oil moving from the extension-side chamber R1 to the compression-side chamber R2, so the pressure in the extension-side chamber R1 rises. However, on the other hand, the pressure in the compression-side chamber R2 is approximately equal to the pressure in the reservoir R. Therefore, the buffer D2 with vehicle height adjustment function generates an extension-side damping force that hinders the extension of the buffer body 1.

[0060] Next, when the buffer body 1 contracts due to external force, the piston 3 inside the cylinder 2 moves towards... Figure 1The piston moves to the right, compressing the compression chamber R2 and expanding the extension chamber R1. As the piston 3 moves, the hydraulic oil ejected from the compression chamber R2 moves through the third channel 15 and the first extension-side check valve 17 of the first channel 13 into the expanded extension chamber R1. When the buffer body 1 retracts, the piston rod 4 enters the cylinder 2, so the amount of hydraulic oil ejected from the compression chamber R2 is excessive relative to the expanded volume in the extension chamber R1, the excess being the volume of the piston rod 4 entering the cylinder 2. This excess hydraulic oil is discharged from the compression chamber R2 through the third channel 15 and then through the first compression-side damping valve 18 of the second channel 14 into the reservoir R. As mentioned above, when the buffer body 1 retracts, the first compression-side damping valve 18 resists the flow of hydraulic oil moving from the compression chamber R2 to the reservoir R, so the pressure in the extension chamber R1 and the compression chamber R2 rises and becomes approximately equal. The piston 3 subjected to the pressure of the compression chamber R2 has a larger pressure area than the piston 3 subjected to the pressure of the extension chamber R1. The larger portion is the cross-sectional area of ​​the piston rod 4. Therefore, the buffer D2 with vehicle height adjustment function generates a compression-side damping force that hinders the contraction of the buffer body 1.

[0061] Therefore, when the buffer D2 with vehicle height adjustment function in the first variation of the first embodiment is selected as a shock absorber, it is the same as the buffer D1 with vehicle height adjustment function in the first embodiment. When the buffer body 1 is extended or retracted by external force, the buffer D1 with vehicle height adjustment function generates a damping force that hinders the extension or retraction of the buffer body 1.

[0062] Next, the operation of the damper D2 with vehicle height adjustment function when the switching valve V1 is selected to the second position 23b will be explained. When the switching valve V1 is selected to the second position 23b, the pump passage 20 is connected to the compression side chamber R2, the third passage 15 is cut off, and there is no hydraulic oil flowing from the switching valve V1 in the third passage 15 to the first connection point J1.

[0063] In this state, when the pump P driven by the motor 21 supplies hydraulic oil from the reservoir R to the compression chamber R2, the hydraulic oil pushes the piston 3 towards... Figure 2 When pushed from the left, the buffer body 1 extends. As the buffer body 1 extends, the compression chamber R2 expands, and the extension chamber R1 compresses, causing hydraulic oil to be ejected from the extension chamber R1. The ejected hydraulic oil is discharged into the reservoir R through the first extension-side damping valve 16 in the first channel 13 and the first compression-side damping valve 18 in the second channel 14.

[0064] Therefore, when the vehicle height adjustment mode is selected for the buffer D2 with vehicle height adjustment function, the buffer body 1 extends due to the drive pump P, raising the vehicle body and increasing the vehicle height. As the buffer body 1 extends, the suspension spring S also extends, reducing its elasticity. Thus, the buffer body 1 shares the vehicle load for support, increasing the pressure in the compression chamber R2. Furthermore, a pump passage check valve 22 is installed on the pump passage 20, preventing the hydraulic oil in the compression chamber R2 from moving. Therefore, even if the drive pump P is stopped, the buffer body 1 will remain extended, and the vehicle height will continue to rise.

[0065] Furthermore, the buffer D2, equipped with vehicle height adjustment function, can adjust the extension of the buffer body 1 according to the amount of hydraulic oil supplied from the pump P. If a stroke sensor is provided to detect the extension and retraction displacement of the buffer body 1, the extension of the buffer body 1 can be determined. Therefore, the extension of the buffer body 1 can be monitored using the stroke sensor, and if the motor 21 is controlled, the extension of the buffer body 1 can be adjusted to a predetermined amount. Additionally, for example, if a vehicle passenger can power on the motor 21, the pump P can be driven until the desired vehicle height is reached, allowing the passenger to adjust the vehicle height.

[0066] Furthermore, the buffer D2 with vehicle height adjustment function is equipped with a pressure reducing valve 101. When the pressure in the compression side chamber R2 exceeds the pressure in the extension side chamber R1 by a specified pressure, the pressure reducing valve 101 opens to allow hydraulic oil to flow from the compression side chamber R2 to the extension side chamber R1. In this way, when the buffer D2 with vehicle height adjustment function is in vehicle height adjustment mode, even if the buffer body 1 retracts while the occupant is driving the vehicle, the buffer body 1 can still retract, thus reducing vehicle body vibration.

[0067] Furthermore, after raising the vehicle height by switching the damper D2 with vehicle height adjustment function to vehicle height adjustment mode, the switching valve V1 is switched from the second position 23b to the first position 23a, turning the damper D2 into shock absorber mode. In this mode, the compression chamber R2 is connected to the shock absorber circuit C1 via the third channel 15, the pump channel 20 is cut off, and the connection between the pump P and the compression chamber R2 is disconnected. As a result, the extended suspension spring S and the damper body 1, after the vehicle height is raised, contract under the load of the vehicle body. Hydraulic oil is then pushed out from the compression chamber R2 and moves to the extension chamber R1 via the first extension side check valve 17. A corresponding amount of hydraulic oil enters the cylinder 2 from the compression chamber R2 via the third channel 15 and the first compression side damping valve 18 and moves to the reservoir R. The suspension spring S contracts until its elastic force balances the load on the vehicle body, so the damper body 1 returns to its pre-raised state. Therefore, when the damper D2 with vehicle height adjustment function switches from vehicle height adjustment mode to shock absorber mode, it can recover to the state before vehicle height adjustment by utilizing the load on the vehicle body. In addition, when the damper body 1 recovers from the extended state to the original state, the first compression side damping valve 18 applies resistance to the flow of hydraulic oil, so the retraction speed of the damper body 1 is appropriately slowed down, so as not to cause discomfort to the occupants.

[0068] In the aforementioned scenario, when the buffer D1 with vehicle height adjustment function is in vehicle height adjustment mode, the vehicle height is lowered by driving pump P; when the buffer D2 with vehicle height adjustment function is in vehicle height adjustment mode, the vehicle height is raised by driving pump P. However, if you want to raise and lower the vehicle height using vehicle height adjustment mode, as follows... Figure 3 The buffer D3 with vehicle height adjustment function in the second variation of the first embodiment shown can be configured as follows.

[0069] The buffer D3 with vehicle height adjustment function in the second variation of the first embodiment differs from the buffer D1 with vehicle height adjustment function in the configuration and location of the switching valve V2.

[0070] In the damper D3 with vehicle height adjustment function, a switching valve V2 is positioned midway between the first channel 13 and the third channel 15. By switching the valve V2, the connection between the extension side chamber R1 and the compression side chamber R2 and the shock absorber circuit C1, the connection between the extension side chamber R1 and the pump channel 20, and the connection between the compression side chamber R2 and the pump channel 20 can be selectively switched. The damper D3 with vehicle height adjustment function has two modes: a vehicle height raising mode and a vehicle height lowering mode. Switching the valve V2 allows switching between these modes, and the shock absorber mode can also be selected.

[0071] Specifically, such as Figure 3 As shown, the switching valve V2 is a three-position five-way solenoid switching valve with five ports a1, b1, t1, t2, and p1. It comprises: a valve body 26 having a left position 26a, a neutral position 26b, and a right position 26c; springs 27a and 27b that clamp the valve body 26 and apply force to it, causing it to select the neutral position 26b; and a solenoid 28, which is a push-pull type. Furthermore, the switching valve V2 connects ports a1 and t1 to the middle of the first channel 13, and is positioned in the middle of the first channel 13, i.e., on the extension side chamber side relative to the first extension-side damping valve 16 and the first extension-side check valve 17. It also connects ports b1 and t2 to the middle of the third channel 15, and connects port p1 to the other end of the pump channel 20.

[0072] When the valve body 26 is not energized by the solenoid 28, the springs 27a and 27b select the neutral position 26b, connect port a1 to port t1 to connect the first channel 13, connect port b1 to port t2 to connect the third channel 15, and close port p1 to cut off the other end of the pump channel 20.

[0073] Furthermore, when the valve body 26 is pushed to the right by energizing the solenoid 28, the left position 26a is selected, the port t1 is closed to cut off the first channel 13, the port a1 is connected to the port p1 to connect the pump channel 20 to the extended side chamber R1, and the port b1 is connected to the port t2 to connect the third channel 15.

[0074] Furthermore, when the valve body 26 is pushed to the left by energizing the solenoid 28, the right position 26c is selected, the port t2 is closed to cut off the third channel 15, the port b1 is connected to the port p1 to connect the pump channel 20 to the compression side chamber R2, and the port a1 is connected to the port t1 to connect the first channel 13.

[0075] Therefore, when the solenoid 28 is not energized and the switching valve V2 is in the neutral position 26b, the pump channel 20 is cut off, the damper body 1 is connected to the shock absorber circuit C1 via the first channel 13 and the third channel 15, the shock absorber circuit C1 is active, and the damper D3 with vehicle height adjustment function is in shock absorber mode. On the other hand, when the solenoid 28 is energized and the switching valve V2 is switched to the left position 26a, the first channel 13 is cut off, the pump channel 20 is connected to the extension side chamber R1, the pump P is active, the compression side chamber R2 is connected to the shock absorber circuit C1 via the third channel 15, and the damper D3 with vehicle height adjustment function is in vehicle height adjustment mode, which lowers the vehicle height. Subsequently, when solenoid 28 is energized and switching valve V2 is switched to the right position 26c, the third channel 15 is cut off, pump channel 20 is connected to the compression side chamber R2, pump P is active, and the extension side chamber R1 is connected to the shock absorber circuit C1 via the first channel 13. The buffer D3 with vehicle height adjustment function becomes a vehicle height adjustment mode that raises the vehicle height. In this way, switching valve V2 can select one of the following modes for the buffer D3 with vehicle height adjustment function: a shock absorber mode that only activates the shock absorber circuit C1, a vehicle height adjustment mode that activates pump P and lowers the vehicle height, or a vehicle height adjustment mode that activates pump P and raises the vehicle height.

[0076] Furthermore, in the buffer D3 with vehicle height adjustment function of this embodiment, the buffer body 1 includes: a pressure relief channel 9, which connects the extension side chamber R1 and the compression side chamber R2; and a pressure reducing valve 102, which is provided on the pressure relief channel 9. When the pressure in the extension side chamber R1 is higher than the pressure in the compression side chamber R2 and the difference between the pressure in the extension side chamber R1 and the compression side chamber R2 reaches the valve opening pressure, the pressure reducing valve 102 opens to allow hydraulic oil (liquid) to flow from the extension side chamber R1 to the compression side chamber R2. When the pressure in the compression side chamber R2 is higher than the pressure in the extension side chamber R1 and the difference between the pressure in the compression side chamber R2 and the extension side chamber R1 reaches the valve opening pressure, the pressure reducing valve 102 opens to allow hydraulic oil (liquid) to flow from the compression side chamber R2 to the extension side chamber R1. According to the buffer D3 with vehicle height adjustment function configured in this way, even if the buffer body 1 extends when the vehicle height is lowered by the passenger using the vehicle height adjustment mode, the pressure in the extension side chamber R1 will not be excessive. In addition, even if the buffer body 1 retracts when the vehicle height is raised by the passenger using the vehicle height adjustment mode, the pressure in the compression side chamber R2 will not be excessive, thus the buffer D3 with vehicle height adjustment function is protected.

[0077] The buffer D3 with vehicle height adjustment function in the second variation of the first embodiment is configured as described above, and its operation will be explained below. First, the operation when the switching valve V2 is selected to the neutral position 26b to put the buffer D3 with vehicle height adjustment function into shock absorber mode will be explained. In this state, the connection state between the buffer body 1 and the shock absorber circuit C1 in the buffer D3 with vehicle height adjustment function is the same as the connection state between the buffer body 1 and the shock absorber circuit C1 in the first embodiment with vehicle height adjustment function in shock absorber mode. Therefore, when the buffer D3 with vehicle height adjustment function in the second variation of the first embodiment is selected into shock absorber mode, it exhibits the same operation as the buffer D1 with vehicle height adjustment function in the first embodiment in shock absorber mode. When the buffer body 1 is extended or retracted by an external force, a damping force that hinders the extension or retraction of the buffer body 1 occurs.

[0078] Next, the operation of the buffer D3 with vehicle height adjustment function when the switching valve V2 is selected to the left position 26a, thus setting it to the vehicle height adjustment mode that lowers the vehicle height, will be described. In this state, the connection state of the buffer body 1 of the buffer D3 with vehicle height adjustment function to the pump P and the shock absorber circuit C1 is the same as that of the buffer body 1 of the buffer D1 with vehicle height adjustment function in the first embodiment in the vehicle height adjustment mode state. Therefore, when the buffer D3 with vehicle height adjustment function in the second variation of the first embodiment is selected to lower the vehicle height adjustment mode, it exhibits the same operation as the buffer D1 with vehicle height adjustment function in the first embodiment in the vehicle height adjustment mode, and the vehicle height is lowered by driving the pump P to retract the buffer body 1. If the vehicle height is lowered and the switching valve V2 is switched to the neutral position 26b so that the buffer D3 with vehicle height adjustment function is in shock absorber mode, then the extension side chamber R1 is connected to the compression side chamber R2 and the reservoir R through the shock absorber circuit C1, allowing the buffer body 1 to extend. Therefore, the buffer body 1 uses the elastic force of the suspension spring S to return to the original displacement state before the vehicle height was lowered.

[0079] Next, the operation of the buffer D3 with vehicle height adjustment function when the switching valve V2 is selected to the right position 26c, so that the buffer D3 with vehicle height adjustment function is in the vehicle height adjustment mode that raises the vehicle height, will be explained. In this state, the connection state of the buffer body 1 of the buffer D3 with vehicle height adjustment function to the pump P and the shock absorber circuit C1 is the same as the connection state of the buffer body 1 of the buffer D2 with vehicle height adjustment function in the first modification of the first embodiment with vehicle height adjustment function in the vehicle height adjustment mode state. Therefore, when the buffer D3 with vehicle height adjustment function in the second modification of the first embodiment is selected to raise the vehicle height mode, it exhibits the same operation as the buffer D2 with vehicle height adjustment function in the first modification of the first embodiment with vehicle height adjustment function in the vehicle height adjustment mode, and the vehicle height can be raised by driving the pump P to extend the buffer body 1. If the vehicle height is increased and the switching valve V2 is switched to the neutral position 26b so that the buffer D3 with vehicle height adjustment function is in shock absorber mode, the hydraulic oil in the compression side chamber R2 can move through the shock absorber circuit C1 to the extension side chamber R1 and the reservoir R, allowing the buffer body 1 to contract. Therefore, the buffer body 1 contracts and is subjected to the vehicle body load, restoring to the original displacement state before the vehicle height was increased.

[0080] As described above, the buffers D1, D2, and D3 with vehicle height adjustment function in this embodiment are configured with the following components: a buffer body 1, which includes a cylinder 2 filled with hydraulic oil (liquid); a piston 3 movably inserted into the cylinder 2 and dividing the cylinder 2 into an extension side chamber R1 and a compression side chamber R2; and a piston rod 4 movably inserted into the cylinder 2 and connected to the piston 3; a suspension spring S, which applies force to the buffer body 1 in the extension direction; a reservoir R, which stores hydraulic oil (liquid); and a shock absorber. The shock absorber circuit C1 is connected to the extension side chamber R1, the compression side chamber R2, and the reservoir R, and generates a damping force in the buffer body 1 when it extends or retracts; the pump P can draw in liquid from the reservoir R and discharge it; the switching valves V1 and V2 are located between the buffer body 1, the shock absorber circuit C1, and the pump P, and can switch between a shock absorber mode that connects the buffer body 1 to the shock absorber circuit C1 to generate a damping force in the buffer body 1, and a vehicle height adjustment mode that connects the buffer body 1 to the pump P.

[0081] In the shock absorbers D1, D2, and D3 configured in this way with vehicle height adjustment function, the shock absorber circuit C1 and pump P can be selectively activated by switching valves V1 and V2. Therefore, the reservoir R, which supplies too much or too little hydraulic oil (liquid) to the cylinder 2 when the shock absorber body 1 generates damping force, can be used as a reservoir to store the hydraulic oil (liquid) supplied to the shock absorber body 1 during vehicle height adjustment. Furthermore, in the shock absorbers D1, D2, and D3 configured in this way with vehicle height adjustment function, the pump P can be driven to supply hydraulic oil (liquid) to the shock absorber body 1 to extend, retract, or expand / contract, so there is no need for a jack to drive the spring support of the suspension spring S.

[0082] As described above, the buffers D1, D2, and D3 with vehicle height adjustment function, constructed in this way, eliminate the need for jacks and jack reservoirs required by conventional buffers with vehicle height adjustment function, thus enabling miniaturization even with vehicle height adjustment function.

[0083] Furthermore, in the vehicle height adjustment function buffers D1, D2, and D3 of this embodiment, in the vehicle height adjustment mode, switching valves V1 and V2 connect pump P to one of the extension side chamber R1 and compression side chamber R2 of the buffer body 1, and connect the other of the extension side chamber R1 and compression side chamber R2 to the reservoir chamber R via the shock absorber circuit C1. With the buffers D1, D2, and D3 configured in this way, during vehicle height adjustment, the compressed chambers in the extension side chamber R1 and compression side chamber R2 are connected to the reservoir chamber R via the shock absorber circuit C1. Therefore, there is no need for a channel connecting the compression side chamber and the reservoir chamber R solely for vehicle height adjustment, thus further miniaturization can be achieved.

[0084] Furthermore, in the buffers D1, D2, and D3 with vehicle height adjustment function in this embodiment, the shock absorber circuit C1 includes: a first channel 13, one end of which is connected to the extension side chamber R1; a second channel 14, which connects the other end of the first channel 13 to the reservoir R; a third channel 15, which connects the connection point between the first channel 13 and the second channel 14, i.e., the first connection point J1, to the compression side chamber R2; and a first extension side damping valve 16, which is disposed on the first channel 13 and controls the flow of hydraulic oil (liquid) from the extension side chamber R1 to the first connection point J1. The system applies resistance to the flow of hydraulic oil (liquid) from the first connection point J1 to the extension chamber R1; a first extension-side check valve 17, which is connected in parallel with the first extension-side damping valve 16 on the first channel 13 and only allows hydraulic oil (liquid) to flow from the first connection point J1 to the extension-side chamber R1; a first compression-side damping valve 18, which is connected in parallel with the first compression-side damping valve 18 on the second channel 14 and applies resistance to the flow of hydraulic oil (liquid) from the first connection point J1 to the reservoir R; and a first compression-side check valve 19, which is connected in parallel with the first compression-side damping valve 18 on the second channel 14 and only allows hydraulic oil (liquid) to flow from the reservoir R to the first connection point J1. According to the buffers D1, D2, D3 configured in this way with vehicle height adjustment function, when switching from vehicle height adjustment mode to shock absorber mode, the buffer body 1 extends or retracts to restore the vehicle height to the original state before vehicle height adjustment. The first extension side damping valve 16 or the first compression side damping valve 18 applies resistance to the flow of hydraulic oil (liquid), so the extension and retraction of the buffer body 1 is slowed down and will not cause discomfort to the passenger.

[0085] Furthermore, when the switching valve V1 has a first position 23a in shock absorber mode that connects the first channel 13 to disconnect the pump P from the buffer body 1, and a second position 23b in vehicle height adjustment mode that disconnects the first channel 13 to connect the pump P to the buffer body 1, the buffer D1 with vehicle height adjustment function can retract the buffer body 1 to lower the vehicle height in vehicle height adjustment mode. Additionally, when the switching valve V1 has a first position 23a in shock absorber mode that connects the third channel 15 to disconnect the pump P from the buffer body 1, and a second position 23b in vehicle height adjustment mode that disconnects the third channel 15 to connect the pump P to the buffer body 1, the buffer D2 with vehicle height adjustment function can raise the buffer body 1 to raise the vehicle height in vehicle height adjustment mode. Furthermore, when the switching valve V2 selectively selects two positions in the shock absorber mode—the neutral position 26b where the first channel 13 and the third channel 15 are connected to disconnect the pump P from the buffer body 1, and the left position 26a where the first channel 13 is disconnected to connect the pump P to the buffer body 1, and the right position 26c where the third channel 15 is disconnected to connect the pump P to the buffer body 1—the buffer D3 with the vehicle height adjustment function can raise and lower the buffer body 1 and raise and lower the vehicle height in the vehicle height adjustment mode.

[0086] Furthermore, in the buffers D1 and D3 with vehicle height adjustment function of this embodiment, the buffer body 1 has: a pressure relief channel 9 connecting the extension side chamber R1 and the compression side chamber R2; and pressure reducing valves 10 and 102 disposed on the pressure relief channel 9. When the differential pressure between the extension side chamber R1 and the compression side chamber R2 reaches the valve opening pressure, the pressure reducing valves 10 and 102 open, allowing hydraulic oil (liquid) to flow from the extension side chamber R1 to the compression side chamber R2. With the buffers D1 and D3 configured thus, even if the buffer body 1 extends while the vehicle is lowered in the vehicle height adjustment mode, the pressure in the extension side chamber R1 will not be excessive, thus protecting the buffers D1 and D3 with vehicle height adjustment function. Furthermore, in the buffers D2 and D3 with vehicle height adjustment function of this embodiment, the buffer body 1 has: a pressure relief channel 9, which connects the extension side chamber R1 and the compression side chamber R2; and pressure reducing valves 101 and 102, which are provided on the pressure relief channel 9. When the differential pressure between the compression side chamber R2 and the extension side chamber R1 reaches the valve opening pressure, the pressure reducing valves 101 and 102 open, allowing hydraulic oil (liquid) to flow from the compression side chamber R2 to the extension side chamber R1. With the buffers D2 and D3 configured in this way, even if the buffer body 1 retracts while the vehicle is being driven with the vehicle height raised in the vehicle height adjustment mode, the pressure in the compression side chamber R2 will not be excessive, thus protecting the buffers D2 and D3 with vehicle height adjustment function.

[0087] <Second Implementation Method>

[0088] like Figure 4 As shown, the buffer D4 with vehicle height adjustment function in the second embodiment includes: a buffer body 1; a suspension spring S, which applies force to the buffer body 1 along the extension direction; a liquid reservoir R, which stores liquid; a shock absorber circuit C2; a pump P; and a switching valve V1. The shock absorber circuit C2 of the buffer D4 with vehicle height adjustment function in the second embodiment differs from that of the buffer D1 with vehicle height adjustment function in the first embodiment.

[0089] The shock absorber circuit C2 is configured with the following components: a fourth channel 31, one end of which is connected to the extension-side chamber R1; a fifth channel 32, which connects the compression-side chamber R2 to the other end of the fourth channel 31; a sixth channel 33, which connects the connection point between the fourth channel 31 and the fifth channel 32, i.e., the second connection point J2, to the reservoir R; a second extension-side damping valve 34, which is disposed on the fourth channel 31 and applies resistance to the flow of hydraulic oil from the extension-side chamber R1 to the second connection point J2; and a second extension-side check valve. Valve 35, the second extension-side check valve 35 and the second extension-side damping valve 34 are connected in parallel on the fourth channel 31, and only allow hydraulic oil to flow from the second connection point J2 to the extension-side chamber R1; second compression-side damping valve 36, the second compression-side damping valve 36 is connected on the fifth channel 32, and applies resistance to the flow of hydraulic oil from the compression-side chamber R2 to the second connection point J2; second compression-side check valve 37, the second compression-side check valve 37 and the second compression-side damping valve 36 are connected in parallel on the fifth channel 32, and only allow hydraulic oil to flow from the second connection point J2 to the compression-side chamber R2.

[0090] As previously described, one end of the fourth channel 31 is connected to the elongation chamber R1, and the other end is connected to the fifth channel 32. Furthermore, one end of the fifth channel 32 is connected to the compression chamber R2, and the other end is connected to the fourth channel 31. Thus, the fourth channel 31 and the fifth channel 32 are connected in series, and the elongation chamber R1 is connected to the compression chamber R2 via the fourth channel 31 and the fifth channel 32. Additionally, one end of the sixth channel 33 is connected to the second connection point J2 between the fourth channel 31 and the fifth channel 32, and the other end is connected to the reservoir R. Therefore, the elongation chamber R1 and the compression chamber R2 are interconnected via the fourth channel 31 and the fifth channel 32. Furthermore, the elongation chamber R1 is connected to the reservoir R via the fourth channel 31 and the sixth channel 33, and the compression chamber R2 is connected to the reservoir R via the fifth channel 32 and the sixth channel 33.

[0091] In the buffer D4 with vehicle height adjustment function of this embodiment, the second extension-side damping valve 34 is a damping valve that only allows hydraulic oil to flow from the extension-side chamber R1 through the fourth channel 31 to the second connection point J2 and applies resistance to the flow of hydraulic oil. For example, it is a vane valve or a lift valve. Alternatively, the second extension-side damping valve 34 can also be a valve that allows bidirectional flow, such as a throttle or a choke. Furthermore, the second extension-side check valve 35 is connected in parallel with the second extension-side damping valve 34 on the fourth channel 31, allowing hydraulic oil to flow from the second connection point J2 through the fourth channel 31 to the extension-side chamber R1, and preventing reverse flow of hydraulic oil. Therefore, when hydraulic oil flows from the extension-side chamber R1 through the fourth channel 31 to the second connection point J2, the hydraulic oil passes through the second extension-side damping valve 34; conversely, when hydraulic oil flows from the second connection point J2 through the fourth channel 31 to the extension-side chamber R1, the hydraulic oil passes through the second extension-side check valve 35.

[0092] In the buffer D4 with vehicle height adjustment function of this embodiment, the second compression-side damping valve 36 is a damping valve that only allows hydraulic oil to flow from the compression-side chamber R2 through the fifth channel 32 to the second connection point J2 and applies resistance to the flow of hydraulic oil. For example, it is a vane valve or a lift valve. Alternatively, the second compression-side damping valve 36 can also be a valve that allows bidirectional flow, such as a throttle or a choke. Furthermore, the second compression-side check valve 37 is connected in parallel with the second compression-side damping valve 36 on the fifth channel 32, allowing hydraulic oil to flow from the second connection point J2 through the fifth channel 32 to the compression-side chamber R2, and preventing reverse flow of hydraulic oil. Therefore, when hydraulic oil flows from the compression-side chamber R2 through the fifth channel 32 to the second connection point J2, the hydraulic oil passes through the second compression-side damping valve 36; conversely, when hydraulic oil flows from the second connection point J2 through the fifth channel 32 to the compression-side chamber R2, the hydraulic oil passes through the second compression-side check valve 37.

[0093] The switching valve V1 is the same as the switching valve V1 in the buffer D1 with vehicle height adjustment function in the first embodiment. It is a two-position three-way solenoid switching valve with three ports a, t, p. It connects ports a, t to the middle of the fourth channel 31, and is located on the extension side chamber side relative to the second extension side damping valve 34 and the second extension side check valve 35. It connects port p to the other end of the pump channel 20. Specifically, the switching valve V1 includes: a valve body 23, which has a first position 23a and a second position 23b. The first position 23a connects port a and port t to connect the fourth channel 31 and closes port p to cut off the other end of the pump channel 20. The second position 23b closes port t to cut off the fourth channel 31 and connects port a and port p to connect the pump channel 20 to the extended side chamber R1. A spring 24 applies force to the valve body 23 to select the first position 23a. A solenoid 25, when energized, counteracts the force of the spring 24 to switch the valve body 23 to the second position 23b. Therefore, when the solenoid 25 is not energized and the switching valve V1 selects the first position 23a, the pump channel 20 is cut off, the buffer body 1 is connected to the shock absorber circuit C2 via the fourth channel 31, the shock absorber circuit C2 is active, and the buffer D4 with vehicle height adjustment function is in shock absorber mode. On the other hand, when solenoid 25 is energized and switching valve V1 is selected to the second position 23b, the fourth channel 31 is cut off, pump channel 20 is connected to the extended side chamber R1, pump P is active, and the damper D4 with vehicle height adjustment function is in vehicle height adjustment mode. In this way, switching valve V1 can switch the damper D4 with vehicle height adjustment function to either the damper mode that only activates the damper circuit C2 or the vehicle height adjustment mode that activates pump P.

[0094] The buffer D4 with vehicle height adjustment function in the second embodiment is configured as described above, and its operation will be explained below. First, the operation when the switching valve V1 selects the first position 23a to put the buffer D4 with vehicle height adjustment function into shock absorber mode will be explained.

[0095] In the shock absorber mode, the elongation side chamber R1, the compression side chamber R2, and the liquid storage chamber R are interconnected via the shock absorber circuit C2 through the switching valve V1. However, on the other hand, the pump channel 20 is cut off, and the connection between the elongation side chamber R1 and the pump P is disconnected.

[0096] Furthermore, when the buffer body 1 extends due to external force, the piston 3 inside the cylinder 2 moves towards... Figure 4The piston moves to the left, compressing the elongation chamber R1 and expanding the compression chamber R2. As the piston 3 moves, hydraulic oil ejected from the elongation chamber R1 moves through the second elongation-side damping valve 34 in the fourth channel 31 and then through the second compression-side check valve 37 in the fifth channel 32 to the expanded compression chamber R2. When the buffer body 1 extends, the piston rod 4 retracts from the cylinder 2. Therefore, the amount of hydraulic oil moving from the elongation chamber R1 to the compression chamber R2 is insufficient to fill the expanded volume of the compression chamber R2, resulting in insufficient hydraulic oil in the compression chamber R2. This insufficient amount of hydraulic oil is the volume of the piston rod 4 retracting from the cylinder 2. This insufficient portion of hydraulic oil is supplied from the reservoir R to the compression chamber R2 through the sixth channel 33 and the second compression-side check valve 37 in the fifth channel 32. As mentioned above, when the buffer body 1 extends, the second extension-side damping valve 34 applies resistance to the flow of hydraulic oil moving from the extension-side chamber R1 to the compression-side chamber R2, so the pressure in the extension-side chamber R1 rises. However, on the other hand, the pressure in the compression-side chamber R2 is approximately equal to the pressure in the reservoir R. Therefore, the buffer D4 with vehicle height adjustment function generates an extension-side damping force that hinders the extension of the buffer body 1.

[0097] When the buffer body 1 contracts due to external force, the piston 3 inside the cylinder 2 moves towards... Figure 1 The piston moves to the right, compressing the compression chamber R2 and expanding the extension chamber R1. As the piston 3 moves, the hydraulic oil ejected from the compression chamber R2 moves into the expanded extension chamber R1 through the second compression-side damping valve 36 in the fifth channel 32 and the second extension-side check valve 35 in the fourth channel 31. When the buffer body 1 retracts, the piston rod 4 enters the cylinder 2, so the amount of hydraulic oil ejected from the compression chamber R2 is excessive compared to the expanded volume in the extension chamber R1; this excess is the volume of the piston rod 4 entering the cylinder 2. This excess hydraulic oil is discharged from the compression chamber R2 through the second compression-side damping valve 36 in the fifth channel 32 and the sixth channel 33 into the reservoir R. Therefore, when the buffer body 1 retracts, the hydraulic oil ejected from the compression chamber R2 must pass through the second compression-side damping valve 36, and the flow of this hydraulic oil is resisted. Therefore, the pressure in the compression chamber R2 rises, and the pressure in the elongation chamber R1 is approximately equal to the pressure in the reservoir R. The buffer D4 with vehicle height adjustment function generates a compression-side damping force that hinders the contraction of the buffer body 1.

[0098] Therefore, when the damper D4 with vehicle height adjustment function is selected in shock absorber mode, when the damper body 1 is extended or retracted by external force, the damper D4 with vehicle height adjustment function generates a damping force that hinders the extension or retraction of the damper body 1.

[0099] Next, the operation of the damper D4 with vehicle height adjustment function when the switching valve V1 is selected to the second position 23b will be explained. When the switching valve V1 is selected to the second position 23b, the pump passage 20 is connected to the extended side chamber R1, the fourth passage 31 is cut off, and there is no hydraulic oil flowing from the switching valve V1 in the fourth passage 31 to the second connection point J2.

[0100] In this state, when the pump P is driven by the motor 21 to supply hydraulic oil from the reservoir R to the extension side chamber R1, the hydraulic oil will push the piston 3 towards... Figure 4 When pushed from the right, the buffer body 1 retracts. As the buffer body 1 retracts, the elongation chamber R1 expands, and the compression chamber R2 compresses, causing hydraulic oil to be ejected from the compression chamber R2. The ejected hydraulic oil is discharged into the reservoir R through the second compression-side damping valve 36 in the fifth channel 32 and the sixth channel 33.

[0101] Therefore, when the vehicle height adjustment function of the buffer D4 is selected in vehicle height adjustment mode, the buffer D4, driven by the pump P, compresses the suspension spring S to retract the buffer body 1, thereby lowering the vehicle height. The elastic force of the suspension spring S increases accordingly with the compression of the suspension spring S, exerting force on the buffer body 1 along the extension direction, thus creating high pressure in the extension side chamber R1. Furthermore, a pump channel check valve 22 is provided on the pump channel 20, preventing the hydraulic oil in the extension side chamber R1 from moving. Therefore, even if the pump P is stopped, the buffer body 1 will remain in a retracted state, and the vehicle height will remain lowered. In addition, the buffer D4 with vehicle height adjustment function can adjust the retraction amount of the buffer body 1 according to the amount of hydraulic oil supplied from the pump P. If a stroke sensor is provided to detect the extension and retraction displacement of the buffer body 1, the extension amount of the buffer body 1 can be measured, thus monitoring the retraction amount of the buffer body 1. Moreover, if the motor 21 is controlled, the retraction amount of the buffer body 1 can be adjusted to a predetermined amount. Furthermore, for example, if the vehicle occupant can power on the motor 21, the pump P can be driven until the vehicle reaches the occupant's desired height, allowing the occupant to adjust the vehicle height.

[0102] Furthermore, when the buffer D4 with vehicle height adjustment function is in vehicle height adjustment mode, if an external force extends the buffer body 1 while it is in a retracted state, and the pressure in the extended side chamber R1 reaches a preset upper limit pressure, the pressure relief valve 10 opens, allowing hydraulic oil to move from the extended side chamber R1 to the compression side chamber R2. Therefore, even if the buffer body 1 extends while the vehicle is in vehicle height adjustment mode, the pressure in the extended side chamber R1 will not be excessive, thus protecting the buffer D4 with vehicle height adjustment function.

[0103] Furthermore, after lowering the vehicle height by switching the damper D4 with vehicle height adjustment function to vehicle height adjustment mode, the switching valve V1 is switched from the second position 23b to the first position 23a, turning the damper D4 into shock absorber mode. In this mode, the extension chamber R1 is connected to the shock absorber circuit C2 via the fourth channel 31, the pump channel 20 is cut off, and the connection between the pump P and the extension chamber R1 is disconnected. As a result, the suspension spring S, compressed after the vehicle height decreases, causes the damper body 1 to extend. Hydraulic oil is then pushed out from the extension chamber R1, moving through the second extension damping valve 34 and the second compression check valve 37 of the fifth channel 32 to the compression chamber R2. Simultaneously, the piston rod 4 withdraws a corresponding amount of hydraulic oil from the cylinder 2, moving from the reservoir R through the sixth channel 33 and the second compression check valve 37 to the compression chamber R2. The suspension spring S extends until its elastic force balances the load from the vehicle body, so the damper body 1 returns from the vehicle height lowered state to its pre-lowered state. Therefore, when the damper D4 with vehicle height adjustment switches from vehicle height adjustment mode to shock absorber mode, it can utilize the elastic force of the suspension spring S to return to its pre-adjustment state. Furthermore, when the damper body 1 returns from the retracted state to its original state, the second extension-side damping valve 34 applies resistance to the hydraulic oil flow, thus appropriately slowing the extension speed of the damper body 1 and preventing discomfort to the occupants.

[0104] In the aforementioned situation, when the buffer D4 with vehicle height adjustment function is in vehicle height adjustment mode, the vehicle height is lowered by driving pump P. However, if you want to raise the vehicle height using vehicle height adjustment mode, as follows... Figure 5 The buffer D5 with vehicle height adjustment function in the first variation of the second embodiment shown can be configured as follows.

[0105] The buffer D5 with vehicle height adjustment function in the first variation of the second embodiment differs from the buffer D4 with vehicle height adjustment function in the setting position of the switching valve V1.

[0106] In the buffer D4 with vehicle height adjustment function, the switching valve V1 is set in the middle of the fourth channel 31. By switching the switching valve V1, the connection between the extension side chamber R1 and the shock absorber circuit C2 and the connection between the extension side chamber R1 and the pump channel 20 can be selectively switched. However, if you want to raise the vehicle height in the vehicle height adjustment mode, as shown in the buffer D5 with vehicle height adjustment function, the switching valve V1 is set in the middle of the fifth channel 32. By switching the switching valve V1, the connection between the compression side chamber R2 and the shock absorber circuit C2 and the connection between the compression side chamber R2 and the pump channel 20 can be selectively switched.

[0107] Specifically, such as Figure 5 As shown, ports a and t of the switching valve V1 are connected to the middle of the fifth channel 32, and port p of the switching valve V1 is connected to the other end of the pump channel 20. That is, when the switching valve V1 is selected in the first position 23a, ports a and t are connected to connect the fifth channel 32, connecting the compression chamber R2 to the shock absorber circuit C2, and port p is closed to disconnect the pump P from the compression chamber R2. Furthermore, when the switching valve V1 is selected in the second position 23b, port t is closed to cut off the fifth channel 32, disconnecting the compression chamber R2 from the shock absorber circuit C2, and ports a and p are connected to connect the pump P to the compression chamber R2. Therefore, without energizing the solenoid 25, when the switching valve V1 is selected in the first position 23a, the pump channel 20 is cut off, the buffer body 1 is connected to the shock absorber circuit C2 via the fifth channel 32, the shock absorber circuit C2 is active, and the buffer D5 with vehicle height adjustment function is in shock absorber mode. On the other hand, when the solenoid 25 is energized and the switching valve V1 is selected to the second position 23b, the fifth channel 32 is cut off, the pump channel 20 is connected to the compression side chamber R2, the pump P is active, and the buffer D5 with vehicle height adjustment function is in vehicle height adjustment mode. In this way, even when the switching valve V1 is in the buffer D5 with vehicle height adjustment function of the first modification of the second embodiment, it can be switched to either the shock absorber mode that only activates the shock absorber circuit C2 or the vehicle height adjustment mode that activates the pump P. Furthermore, in the buffer D5 with vehicle height adjustment function of the first modification, a pressure reducing valve 101 is provided on the pressure relief channel 9 in the opposite direction to that of the buffer D1 with vehicle height adjustment function.

[0108] The buffer D5 with vehicle height adjustment function in the first variation of the second embodiment is configured as described above, and its operation will be explained below. First, the operation when the switching valve V1 selects the first position 23a to put the buffer D5 with vehicle height adjustment function into shock absorber mode will be explained.

[0109] In the damper mode, the compression chamber R2 is connected to the damper circuit C2 via the fifth channel 32 through the switching valve V1. The extension chamber R1, the compression chamber R2 and the liquid storage chamber R are connected to each other through the damper circuit C2. However, on the other hand, the pump channel 20 is cut off, and the connection between the compression chamber R2 and the pump P is disconnected.

[0110] First, when the buffer body 1 extends due to external force, the piston 3 inside the cylinder 2 moves towards... Figure 1 The piston moves to the left, compressing the elongation chamber R1 and expanding the compression chamber R2. As the piston 3 moves, hydraulic oil ejected from the elongation chamber R1 moves through the second elongation-side damping valve 34 in the fourth channel 31 and then through the second compression-side check valve 37 in the fifth channel 32 to the expanded compression chamber R2. When the buffer body 1 extends, the piston rod 4 retracts from the cylinder 2. Therefore, the amount of hydraulic oil moving from the elongation chamber R1 to the compression chamber R2 is insufficient to fill the expanded volume of the compression chamber R2, resulting in insufficient hydraulic oil in the compression chamber R2. This insufficient amount of hydraulic oil is the volume of the piston rod 4 retracting from the cylinder 2. This insufficient portion of hydraulic oil is supplied from the reservoir R to the compression chamber R2 through the sixth channel 33 and the second compression-side check valve 37 in the fifth channel 32. As mentioned above, when the buffer body 1 extends, the second extension-side damping valve 34 applies resistance to the flow of hydraulic oil moving from the extension-side chamber R1 to the compression-side chamber R2, so the pressure in the extension-side chamber R1 rises. However, on the other hand, the pressure in the compression-side chamber R2 is approximately equal to the pressure in the reservoir R. Therefore, the buffer D2 with vehicle height adjustment function generates an extension-side damping force that hinders the extension of the buffer body 1.

[0111] Next, when the buffer body 1 contracts due to external force, the piston 3 inside the cylinder 2 moves towards... Figure 1The piston moves to the right, compressing the compression chamber R2 and expanding the extension chamber R1. As the piston 3 moves, the hydraulic oil ejected from the compression chamber R2 moves through the second compression-side damping valve 36 in the fifth channel 32 and the second extension-side check valve 35 in the fourth channel 31 into the expanded extension chamber R1. When the buffer body 1 retracts, the piston rod 4 enters the cylinder 2, so the amount of hydraulic oil ejected from the compression chamber R2 is excessive relative to the expanded volume in the extension chamber R1; this excess is the volume of the piston rod 4 entering the cylinder 2. This excess hydraulic oil, after passing through the second compression-side damping valve 36 in the fifth channel 32 from the compression chamber R2, is discharged into the reservoir R via the sixth channel 33. As mentioned earlier, when the buffer body 1 retracts, the hydraulic oil ejected from the compression chamber R2 must pass through the second compression-side damping valve 36, and the flow of this hydraulic oil is resisted. Therefore, the pressure in the compression chamber R2 rises, and the pressure in the elongation chamber R1 is approximately equal to the pressure in the reservoir R. The buffer D5 with vehicle height adjustment function generates a compression-side damping force that hinders the contraction of the buffer body 1.

[0112] Therefore, when the damper D5 with vehicle height adjustment function is selected in shock absorber mode, when the damper body 1 is extended or retracted by external force, the damper D5 with vehicle height adjustment function generates a damping force that hinders the extension or retraction of the damper body 1.

[0113] Next, the operation of the damper D5 with vehicle height adjustment function when the switching valve V1 is selected to the second position 23b will be explained. When the switching valve V1 is selected to the second position 23b, the pump passage 20 is connected to the compression side chamber R2, the fifth passage 32 is cut off, and there is no hydraulic oil flowing from the switching valve V1 in the fifth passage 32 to the second connection point J2.

[0114] In this state, when the pump P driven by the motor 21 supplies hydraulic oil from the reservoir R to the compression chamber R2, the hydraulic oil pushes the piston 3 towards... Figure 5 When pushed from the left, the buffer body 1 extends. As the buffer body 1 extends, the compression chamber R2 expands, and the extension chamber R1 compresses, causing hydraulic oil to be ejected from the extension chamber R1. The ejected hydraulic oil is discharged into the reservoir R through the second extension-side damping valve 34 in the fourth channel 31 and the sixth channel 33.

[0115] Therefore, when the vehicle height adjustment mode is selected for the buffer D5 with vehicle height adjustment function, the buffer body 1 extends due to the drive pump P, raising the vehicle body and increasing the vehicle height. As the buffer body 1 extends, the suspension spring S also extends, reducing its elasticity. Thus, the buffer body 1 shares the vehicle load for support, increasing the pressure in the compression chamber R2 to high pressure. Furthermore, a pump passage check valve 22 is installed on the pump passage 20, preventing the hydraulic oil in the extended chamber R1 from moving. Therefore, even if the drive pump P is stopped, the buffer body 1 will remain extended, and the vehicle height will continue to rise.

[0116] Furthermore, the buffer D5, equipped with a vehicle height adjustment function, can adjust the extension of the buffer body 1 according to the amount of hydraulic oil supplied from the pump P. If a stroke sensor is provided to detect the extension and retraction displacement of the buffer body 1, the extension of the buffer body 1 can be determined. Therefore, the extension of the buffer body 1 can be monitored using the stroke sensor, and if the motor 21 is controlled, the extension of the buffer body 1 can be adjusted to a predetermined amount. Additionally, for example, if a vehicle passenger can power on the motor 21, the pump P can be driven until the desired vehicle height is reached, allowing the passenger to adjust the vehicle height.

[0117] Furthermore, the buffer D5 with vehicle height adjustment function is equipped with a pressure reducing valve 101. When the pressure in the compression side chamber R2 exceeds the pressure in the extension side chamber R1 by a specified pressure, the pressure reducing valve 101 opens to allow hydraulic oil to flow from the compression side chamber R2 to the extension side chamber R1. In this way, when the buffer D5 with vehicle height adjustment function is in vehicle height adjustment mode, even if the buffer body 1 retracts while the occupant is driving the vehicle, the buffer body 1 can still retract, thus reducing vehicle body vibration.

[0118] Furthermore, after raising the vehicle height by switching the damper D5 with vehicle height adjustment function to vehicle height adjustment mode, and then switching the switching valve V1 from the second position 23b to the first position 23a to make the damper D2 with vehicle height adjustment function a shock absorber, the compression side chamber R2 is connected to the shock absorber circuit C2 through the fifth channel 32, the pump channel 20 is cut off, and the connection between the pump P and the compression side chamber R2 is disconnected. As a result, the extended suspension spring S and the damper body 1, after the vehicle height is raised, are subjected to load from the vehicle body and contract, so hydraulic oil is pushed out from the compression side chamber R2 and moves to the extension side chamber R1 through the second compression side damping valve 36 and the second extension side check valve 35. The piston rod 4 enters the cylinder 2 with a corresponding volume of hydraulic oil, which moves from the compression side chamber R2 through the second compression side damping valve 36 of the fifth channel 32 and the sixth channel 33 to the reservoir R. As the suspension spring S contracts until its elastic force balances the load from the vehicle body, the damper body 1 returns from the vehicle height-raised state to its pre-raised state. Therefore, when the damper D5 with vehicle height adjustment switches from vehicle height adjustment mode to shock absorber mode, it can utilize the load from the vehicle body to return to its pre-adjustment state. Furthermore, when the damper body 1 returns from its extended state to its original state, the second compression-side damping valve 36 applies resistance to the hydraulic oil flow, thus appropriately slowing the contraction speed of the damper body 1 and preventing discomfort to the occupants.

[0119] In the aforementioned scenario, when the buffer D4 with vehicle height adjustment function is in vehicle height adjustment mode, the vehicle height is lowered by driving pump P; when the buffer D5 with vehicle height adjustment function is in vehicle height adjustment mode, the vehicle height is raised by driving pump P. However, if you want to raise and lower the vehicle height using vehicle height adjustment mode, as follows... Figure 6 The buffer D6 with vehicle height adjustment function in the second variation of the second embodiment shown can be configured as follows.

[0120] The buffer D6 with vehicle height adjustment function in the second variation of the second embodiment differs from the buffer D1 with vehicle height adjustment function in the configuration and location of the switching valve V2.

[0121] In the damper D6 with vehicle height adjustment function, a switching valve V2 is positioned midway between the fourth channel 31 and the fifth channel 32. By switching the valve V2, the connections between the extension side chamber R1 and the compression side chamber R2 and the shock absorber circuit C2, the connection between the extension side chamber R1 and the pump channel 20, and the connection between the compression side chamber R2 and the pump channel 20 can be selectively switched. The damper D6 with vehicle height adjustment function has two modes: a vehicle height raising mode and a vehicle height lowering mode. Switching the valve V2 allows switching between these modes, and also allows selection of the shock absorber mode.

[0122] The switching valve V2 is configured the same as the switching valve V2 in the buffer D3 with vehicle height adjustment function in the second variation of the first embodiment. Furthermore, the switching valve V2 connects ports a1,t1 to the middle of the fourth channel 31, and is positioned in the middle of the fourth channel 31, on the extension side chamber side relative to the second extension side damping valve 34 and the second extension side check valve 35. It also connects ports b1,t2 to the middle of the fifth channel 32, and is positioned in the middle of the fifth channel 32, on the compression side chamber side relative to the second compression side damping valve 36 and the second compression side check valve 37. Finally, it connects port p1 to the other end of the pump channel 20.

[0123] When the valve body 26 is not energized by the solenoid 28, the springs 27a and 27b select the neutral position 26b, connect port a1 to port t1 to connect the fourth channel 31, connect port b1 to port t2 to connect the fifth channel 32, and close port p1 to cut off the other end of the pump channel 20.

[0124] Furthermore, when the valve body 26 is pushed to the right by energizing the solenoid 28, the left position 26a is selected, the port t1 is closed to cut off the fourth channel 31, the port a1 is connected to the port p1 to connect the pump channel 20 to the elongated side chamber R1, and the port b1 is connected to the port t2 to connect the fifth channel 32.

[0125] Furthermore, when the valve body 26 is pushed to the left by energizing the solenoid 28, the right position 26c is selected, the port t2 is closed to cut off the fifth channel 32, the port b1 is connected to the port p1 to connect the pump channel 20 to the compression side chamber R2, and the port a1 is connected to the port t1 to connect the fourth channel 31.

[0126] Therefore, when the solenoid 28 is not energized and the switching valve V2 is in the neutral position 26b, the pump channel 20 is cut off, the buffer body 1 is connected to the shock absorber circuit C2 via the fourth channel 31 and the fifth channel 32, the shock absorber circuit C2 is effective, and the buffer D6 with vehicle height adjustment function becomes the shock absorber mode.

[0127] On the other hand, when solenoid 28 is energized and switching valve V2 is switched to the left position 26a, the fourth channel 31 is cut off, pump channel 20 is connected to the extension side chamber R1, pump P is active, and compression side chamber R2 is connected to shock absorber circuit C2 via the fifth channel 32. The buffer D6 with vehicle height adjustment function then enters the vehicle height adjustment mode, lowering the vehicle height. Furthermore, when solenoid 28 is energized and switching valve V2 is switched to the right position 26c, the fifth channel 32 is cut off, pump channel 20 is connected to compression side chamber R2, pump P is active, and extension side chamber R1 is connected to shock absorber circuit C2 via the fourth channel 31. The buffer D6 with vehicle height adjustment function then enters the vehicle height adjustment mode, raising the vehicle height. In this way, switching valve V2 can selectively switch the buffer D6 with vehicle height adjustment function to one of the following modes: shock absorber mode that only activates shock absorber circuit C2, vehicle height adjustment mode that activates pump P and lowers the vehicle height, or vehicle height adjustment mode that activates pump P and raises the vehicle height.

[0128] Furthermore, in the buffer D6 with vehicle height adjustment function in this embodiment, the buffer body 1 includes: a pressure relief channel 9, which connects the extension side chamber R1 and the compression side chamber R2; and a pressure reducing valve 102, which is disposed on the pressure relief channel 9. When the pressure in the extension side chamber R1 is higher than the pressure in the compression side chamber R2, and the difference between the pressure in the extension side chamber R1 and the pressure in the compression side chamber R2 reaches the valve opening pressure, the pressure reducing valve 102 opens to allow hydraulic oil (liquid) to flow from the extension side chamber R1 to the compression side chamber R2. When the pressure in the compression side chamber R2 is higher than the pressure in the extension side chamber R1, and the difference between the pressure in the compression side chamber R2 and the pressure in the extension side chamber R1 reaches the valve opening pressure, the pressure reducing valve 102 opens to allow hydraulic oil (liquid) to flow from the compression side chamber R2 to the extension side chamber R1. According to the buffer D6 with vehicle height adjustment function configured in this way, even if the buffer body 1 extends when the vehicle height is lowered by the passenger using the vehicle height adjustment mode, the pressure in the extension side chamber R1 will not be excessive. In addition, even if the buffer body 1 retracts when the vehicle height is raised by the passenger using the vehicle height adjustment mode, the pressure in the compression side chamber R2 will not be excessive, thus the buffer D6 with vehicle height adjustment function is protected.

[0129] The buffer D6 with vehicle height adjustment function in the second variation of the second embodiment is configured as described above, and its operation will be explained below. First, the operation when the switching valve V2 is selected to the neutral position 26b to put the buffer D6 with vehicle height adjustment function into shock absorber mode will be explained. In this state, the connection state between the buffer body 1 and the shock absorber circuit C2 in the buffer D4 with vehicle height adjustment function is the same as the connection state between the buffer body 1 and the shock absorber circuit C2 in the second embodiment with vehicle height adjustment function in shock absorber mode. Therefore, when the buffer D6 with vehicle height adjustment function in the second variation of the second embodiment is selected into shock absorber mode, it exhibits the same operation as the buffer D4 with vehicle height adjustment function in the second embodiment in shock absorber mode. When the buffer body 1 expands or contracts due to external force, a damping force that hinders the expansion or contraction of the buffer body 1 occurs.

[0130] Next, the operation of the buffer D6 with vehicle height adjustment function when the switching valve V2 is selected to the left position 26a, thus setting it to the vehicle height adjustment mode that lowers the vehicle height, will be explained. In this state, the connection state of the buffer body 1 of the buffer D6 with vehicle height adjustment function to the pump P and the shock absorber circuit C2 is the same as that of the buffer body 1 of the buffer D4 with vehicle height adjustment function in the second embodiment, which is in the vehicle height adjustment mode state. Therefore, when the buffer D6 with vehicle height adjustment function in the second variation of the second embodiment is selected to lower the vehicle height adjustment mode, it exhibits the same operation as the buffer D4 with vehicle height adjustment function in the second embodiment, which lowers the vehicle height by driving the pump P to retract the buffer body 1. If the vehicle height is lowered and the switching valve V2 is switched to the neutral position 26b so that the buffer D6 with vehicle height adjustment function is in shock absorber mode, the hydraulic oil in the extension side chamber R1 is connected to the compression side chamber R2 and the reservoir R through the shock absorber circuit C2, allowing the buffer body 1 to extend. Therefore, the buffer body 1 uses the elastic force of the suspension spring S to return to the original displacement state before the vehicle height was lowered.

[0131] Next, the operation of the buffer D6 with vehicle height adjustment function when the switching valve V2 is selected to the right position 26c, so that the buffer D6 with vehicle height adjustment function is in the vehicle height adjustment mode that raises the vehicle height, will be explained. In this state, the connection state of the buffer body 1 of the buffer D6 with vehicle height adjustment function to the pump P and the shock absorber circuit C2 is the same as that of the buffer body 1 of the buffer D5 with vehicle height adjustment function in the first modification of the second embodiment with vehicle height adjustment function in the vehicle height adjustment mode state. Therefore, when the buffer D6 with vehicle height adjustment function in the second modification of the second embodiment is selected to raise the vehicle height mode, it exhibits the same operation as the buffer D5 with vehicle height adjustment function in the first modification of the second embodiment with vehicle height adjustment function in the vehicle height adjustment mode, and the vehicle height can be raised by driving the pump P to extend the buffer body 1. If the vehicle height is increased and the switching valve V2 is switched to the neutral position 26b so that the buffer D6 with vehicle height adjustment function is in shock absorber mode, the hydraulic oil in the compression side chamber R2 can move through the shock absorber circuit C2 to the extension side chamber R1 and the reservoir R, allowing the buffer body 1 to contract. Therefore, the buffer body 1 contracts and is subjected to the vehicle body load, restoring to the original displacement state before the vehicle height was increased.

[0132] As shown above, the buffers D4, D5, and D6 with vehicle height adjustment function in this embodiment are configured with the following components: a buffer body 1, which includes a cylinder 2 filled with hydraulic oil (liquid); a piston 3 movably inserted into the cylinder 2 and dividing the cylinder 2 into an extension side chamber R1 and a compression side chamber R2; and a piston rod 4 movably inserted into the cylinder 2 and connected to the piston 3; a suspension spring S, which applies force to the buffer body 1 in the extension direction; a reservoir R, which stores hydraulic oil (liquid); and a shock absorber. The shock absorber circuit C1 is connected to the extension side chamber R1, the compression side chamber R2, and the reservoir R, and generates a damping force in the buffer body 1 when it extends or retracts; the pump P can draw in liquid from the reservoir R and discharge it; the switching valves V1 and V2 are located between the buffer body 1, the shock absorber circuit C1, and the pump P, and can switch between a shock absorber mode that connects the buffer body 1 to the shock absorber circuit C1 to generate a damping force in the buffer body 1, and a vehicle height adjustment mode that connects the buffer body 1 to the pump P.

[0133] In the shock absorbers D4, D5, and D6 configured with vehicle height adjustment, the damper circuit C2 and pump P can be selectively activated via switching valves V1 and V2. Therefore, the reservoir R, which supplies excessive or insufficient hydraulic oil (liquid) to the cylinder 2 when the shock absorber body 1 generates damping force, can be used as a reservoir for storing hydraulic oil (liquid) supplied to the shock absorber body 1 during vehicle height adjustment. Furthermore, in the shock absorbers D4, D5, and D6 configured with vehicle height adjustment, pump P can be driven to supply hydraulic oil (liquid) to the shock absorber body 1 to extend, retract, or expand / contract, thus eliminating the need for a jack to drive the spring supports of the suspension springs S.

[0134] As described above, the buffers D4, D5, and D6 with vehicle height adjustment function, constructed in this way, eliminate the need for jacks and jack reservoirs required by conventional buffers with vehicle height adjustment function, thus enabling miniaturization even with vehicle height adjustment function.

[0135] Furthermore, in the vehicle height adjustment function buffers D4, D5, and D6 of this embodiment, in the vehicle height adjustment mode, switching valves V1 and V2 connect pump P to one of the extension side chamber R1 and compression side chamber R2 of the buffer body 1, and connect the other of the extension side chamber R1 and compression side chamber R2 to the reservoir chamber R via the shock absorber circuit C2. With the buffers D4, D5, and D6 configured in this way, during vehicle height adjustment, the compressed chambers in the extension side chamber R1 and compression side chamber R2 are connected to the reservoir chamber R via the shock absorber circuit C2. Therefore, there is no need for a channel connecting the compression side chamber and the reservoir chamber R solely for vehicle height adjustment, thus further miniaturization can be achieved.

[0136] Furthermore, in the buffers D4, D5, and D6 with vehicle height adjustment function in this embodiment, the shock absorber circuit C2 includes: a fourth channel 31, one end of which is connected to the extension side chamber R1; a fifth channel 32, which connects the compression side chamber R2 to the other end of the fourth channel 31; a sixth channel 33, which connects the connection point between the fourth channel 31 and the fifth channel 32, i.e., the second connection point J2, to the reservoir R; and a second extension side damping valve 34, which is disposed on the fourth channel 31 and regulates the hydraulic oil flowing from the extension side chamber R1 to the second connection point J2. The flow is resisted by: a second extension-side check valve 35, which is connected in parallel with a second extension-side damping valve 34 on the fourth channel 31 and only allows hydraulic oil to flow from the second connection point J2 to the extension-side chamber R1; a second compression-side damping valve 36, which is connected in parallel with a second compression-side damping valve 36 on the fifth channel 32 and applies resistance to the flow of hydraulic oil from the compression-side chamber R2 to the second connection point J2; and a second compression-side check valve 37, which is connected in parallel with a second compression-side damping valve 36 on the fifth channel 32 and only allows hydraulic oil to flow from the second connection point J2 to the compression-side chamber R2. According to the buffers D4, D5, D6 configured in this way with vehicle height adjustment function, when switching from vehicle height adjustment mode to shock absorber mode, the buffer body 1 extends or retracts to restore the vehicle height to its original state before vehicle height adjustment. The second extension side damping valve 34 or the second compression side damping valve 36 applies resistance to the flow of hydraulic oil (liquid), so the extension and retraction of the buffer body 1 is slowed down and will not cause discomfort to the passenger.

[0137] Furthermore, when the switching valve V1 has a first position 23a in shock absorber mode where the fourth channel 31 is connected to disconnect the pump P from the buffer body 1, and a second position 23b in vehicle height adjustment mode where the fourth channel 31 is disconnected to connect the pump P to the buffer body 1, the buffer D4 with vehicle height adjustment function can retract the buffer body 1 to lower the vehicle height in vehicle height adjustment mode. Additionally, when the switching valve V1 has a first position 23a in shock absorber mode where the fifth channel 32 is connected to disconnect the pump P from the buffer body 1, and a second position 23b in vehicle height adjustment mode where the fifth channel 32 is disconnected to connect the pump P to the buffer body 1, the buffer D5 with vehicle height adjustment function can raise the buffer body 1 to raise the vehicle height in vehicle height adjustment mode. Furthermore, when the switching valve V2 selectively selects two positions in the shock absorber mode—the neutral position 26b where the fourth channel 31 and the fifth channel 32 are connected to disconnect the pump P from the buffer body 1, and the left position 26a where the fourth channel 31 is disconnected to connect the pump P to the buffer body 1, and the right position 26c where the fifth channel 32 is disconnected to connect the pump P to the buffer body 1—the buffer D6 with the vehicle height adjustment function can raise and lower the buffer body 1 and raise and lower the vehicle height in the vehicle height adjustment mode.

[0138] Furthermore, in the buffers D4 and D6 with vehicle height adjustment function of this embodiment, the buffer body 1 has: a pressure relief channel 9 connecting the extension side chamber R1 and the compression side chamber R2; and pressure reducing valves 10 and 102 disposed on the pressure relief channel 9. When the differential pressure between the extension side chamber R1 and the compression side chamber R2 reaches the valve opening pressure, the pressure reducing valves 10 and 102 open, allowing hydraulic oil (liquid) to flow from the extension side chamber R1 to the compression side chamber R2. With the buffers D4 and D6 configured thus, even if the buffer body 1 extends while the vehicle is lowered in the vehicle height adjustment mode, the pressure in the extension side chamber R1 will not be excessive, thus protecting the buffers D4 and D6 with vehicle height adjustment function. Furthermore, in the buffers D5 and D6 with vehicle height adjustment function of this embodiment, the buffer body 1 has: a pressure relief channel 9, which connects the extension side chamber R1 and the compression side chamber R2; and pressure reducing valves 101 and 102, which are provided on the pressure relief channel 9. When the differential pressure between the compression side chamber R2 and the extension side chamber R1 reaches the valve opening pressure, the pressure reducing valves 101 and 102 open, allowing hydraulic oil (liquid) to flow from the compression side chamber R2 to the extension side chamber R1. With the buffers D5 and D6 configured in this way, even if the buffer body 1 retracts while the vehicle is being driven with the vehicle height raised in the vehicle height adjustment mode, the pressure in the compression side chamber R2 will not be excessive, thus protecting the buffers D5 and D6 with vehicle height adjustment function.

[0139] <Third Implementation Method>

[0140] like Figure 7 As shown, the buffer D7 with vehicle height adjustment function in the third embodiment includes: a buffer body 1; a suspension spring S, which applies force to the buffer body 1 along its extension direction; a liquid reservoir R, which stores liquid; a shock absorber circuit C1; a pump P1, which can discharge in both directions; a pump circuit PC; and a switching valve V3. The buffer D7 with vehicle height adjustment function in the third embodiment, compared to the buffer D1 with vehicle height adjustment function in the first embodiment, further includes a pump circuit PC, and the configurations of the pump P1 and the switching valve V3 are different.

[0141] The pump circuit PC includes: a supply channel 41, one end of which is connected to a switching valve V3 and a bidirectional discharge pump P1 is installed in the middle; an operating check valve OV, which is located in the middle of the supply channel 41, i.e., on the side opposite to the pump P1 and the switching valve V3; a first switching channel 42, one end of which is connected to the middle of the supply channel 41, i.e., between the pump P1 and the operating check valve OV; a second switching channel 43, one end of which is connected to the middle of the supply channel 41, i.e., on the opposite side opposite to the pump P1 and the switching valve; and a suction channel 44, one end of which is connected to the liquid storage chamber R. The system includes: a return channel 45, one end of which is connected to the liquid storage chamber R, and the other end of which is connected to the middle of the supply channel 41, i.e., connected to the opposite side of the pump P and the switching valve; a pump pressure relief channel 46, one end of which is connected to the liquid storage chamber R, and the other end of which is connected to the middle of the supply channel 41, i.e., connected between the pump P and the operating check valve OV; a directional switching valve 47, used to switch the connection state of the first switching channel 42 and the second switching channel 43 with the suction channel 44; a throttling orifice 48, which is disposed on the return channel 45; and a pump pressure reducing valve 49, which is disposed on the pump pressure relief channel 46.

[0142] One end of the supply channel 41 is connected to the switching valve V3, and the supply channel 41 is also connected to the operating check valve OV. Pump P1 is a bidirectional discharge pump, driven by motor 21. When rotating forward, it discharges pressurized oil through the operating check valve OV to the switching valve V3; when rotating in reverse, it supplies pressurized oil as pilot pressure to the operating check valve OV. Alternatively, pump P1 can be a gear pump, but any type of bidirectional discharge pump is acceptable.

[0143] When the pilot pressure is not applied, the check valve OV only allows hydraulic oil to flow from pump P1 to switching valve V3 through supply channel 41, preventing reverse flow. However, when the pilot pressure is applied from pump P1, the check valve OV is opened, allowing not only hydraulic oil to flow from pump P1 to switching valve V3 through supply channel 41, but also hydraulic oil to flow from switching valve V3 to pump P1.

[0144] The directional switching valve 47 is a three-position three-way directional switching valve with three ports a4, b4, and t4. Port a4 is connected to the other end of the first switching channel 42, port b4 is connected to the other end of the second switching channel 43, and port t4 is connected to the other end of the suction channel 44.

[0145] Specifically, the directional switching valve 47 includes: a valve body 50, which has a neutral position 50a, a supply position 50b, and a discharge position 50c. The neutral position 50a cuts off ports a4, b4, and t4. The supply position 50b connects ports b4 and t4 to connect the second switching channel 43 to the liquid storage chamber R via the suction channel 44 and cuts off port a4. The discharge position 50c connects ports a4 and t4 to connect the first switching channel 42 to the liquid storage chamber R via the suction channel 44 and cuts off port b4. Springs 51a and 51b clamp the valve body 50 and apply force to it from both sides, causing the valve body 50 to select a neutral position 50a; a first pilot channel 52 uses the pressure between the pump P1 in the supply channel 41 and the operating check valve OV as a pilot pressure, causing the valve body 50 to select a supply position 50b; a second pilot channel 53 uses the pressure on the opposite side of the switching valve of the supply channel 41 relative to the pump P1 as a pilot pressure, causing the valve body 50 to select a discharge position 50c.

[0146] The pump circuit PC is configured as described above, and its operation will be explained below. When the drive motor 21 causes the pump P1 to rotate forward, the pressure on the switching valve side of the supply channel 41 relative to the pump P1 increases by driving the pump P1, so the directional switching valve 47 switches from the neutral position 50a to the supply position 50b. Then, the side of the supply channel 41 opposite to the switching valve of the pump P1 is connected to the reservoir R via the second switching channel 43 and the suction channel 44, so the pump P1 draws in hydraulic oil from the reservoir R and discharges hydraulic oil to the switching valve V3. The hydraulic oil discharged from the pump P1 pushes open the operating check valve OV and flows to the switching valve V3. Furthermore, when the pressure on the switching valve side of the supply channel 41 relative to the pump P1 is excessive due to the forward rotation of the pump P1, the pump pressure reducing valve 49 opens, and the hydraulic oil is discharged into the reservoir R via the pump pressure relief channel 46, thus protecting the pump circuit PC.

[0147] Conversely, when the drive motor 21 reverses the pump P1, the pressure on the opposite side of the switching valve of the supply channel 41 relative to the pump P1 increases by driving the pump P1, so the directional switching valve 47 switches from the neutral position 50a to the discharge position 50c. Thus, the switching valve side of the supply channel 41 relative to the pump P1 is connected to the reservoir R via the first switching channel 42 and the suction channel 44, so the pump P1 draws in hydraulic oil from the reservoir R and discharges hydraulic oil. The hydraulic oil discharged from the pump P1 flows back to the reservoir R through the throttle orifice 48 of the return channel 45, so the pressure on the opposite side of the switching valve of the pump P1 in the supply channel 41 increases by the amount of pressure loss in the throttle orifice 48, and acts as the pilot pressure for operating the check valve OV. The operating check valve OV, subjected to the pilot pressure, opens, allowing hydraulic oil to flow from the switching valve V3 through the supply channel 41 between the switching valve V3 and the pump P1 to the pump P1.

[0148] Next, the difference between switching valve V3 and switching valve V1 is that switching valve V3 has a pilot channel 55 instead of solenoid 25, which guides the discharge pressure of pump P1 as pilot pressure. Therefore, switching valve V3 has the same valve body 23 and spring 24 as switching valve V1, but on the other hand, it also has a pilot channel 55 instead of solenoid, which guides the discharge pressure of pump P1 as pilot pressure. Moreover, port p of switching valve V3 is connected to one end of supply channel 41, and pilot channel 55 uses the pressure in the middle of supply channel 41, i.e., between switching valve V3 and operating check valve OV, as pilot pressure to act on valve body 23, causing it to select the second position 23b.

[0149] When pump P1 rotates forward, the direction switching valve 47 switches to the supply position 50b. The hydraulic oil discharged from pump P1 flows through the supply channel 41 to the switching valve V3. The pressure between pump P1 and switching valve V3 in the supply channel 41 increases, so switching valve V3 switches to the second position 23b. Therefore, when pump P1 rotates forward, switching valve V3 automatically switches to the second position 23b under the pilot pressure input from pump P1, switching the buffer body 1 to the vehicle height adjustment mode, and supplying hydraulic oil to the extension side chamber R1.

[0150] Furthermore, when pump P1 is rotated forward and then stopped, the directional switching valve 47 switches to the neutral position 50a, the check valve OV is closed, and the area between the switching valve V3 and the check valve OV in the supply channel 41 becomes high pressure, with the switching valve V3 continuously maintaining the second position 23b. That is, even if pump P1 is stopped after being rotated forward, the damper body 1 will maintain the vehicle height adjustment mode. When pump P1 is reversed from this state, the hydraulic oil discharged from pump P1 flows to the reservoir R through the return channel 45, the directional switching valve 47 switches to the discharge position 50c, and the switching valve side of the supply channel 41 relative to pump P1 is connected to the reservoir R. Therefore, the check valve OV is opened, the pilot pressure acting on the switching valve V3 is released, the switching valve V3 switches to the first position 23a, and the damper body 1 returns to the shock absorber mode. To return the damper body 1 to the shock absorber mode, the switching valve V3 simply switches from the second position 23b to the first position 23a. That is, in order to reduce the pressure between the switching valve V3 and the operating check valve OV of the supply channel 41 through which the forward conversion of pump P1 is converted into high pressure, it is only necessary to temporarily open the operating check valve OV. Therefore, the reverse drive of pump P1 only needs to be performed for a very short time.

[0151] After the switching valve V3 is switched to the first position 23a, when the pump P1 is stopped, the directional switching valve 47 selects the neutral position 50a. The pressure on the switching valve side of the supply channel 41 relative to the pump P1 does not increase. Therefore, the switching valve V3 selects the first position 23a to maintain the shock absorber mode of the buffer body 1.

[0152] That is, when the shock absorber mode is selected, as long as the pump P1 is not driven, the switching valve V3 selects the first position 23a, the pump circuit PC is cut off, the buffer body 1 is connected to the shock absorber circuit C1 through the first channel 13 and the third channel 15, the shock absorber circuit C1 is effective, and the buffer D7 with vehicle height adjustment function continues to maintain the shock absorber mode.

[0153] On the other hand, when the shock absorber mode is selected, when the pump P1 is driven in the forward direction, the switching valve V3 switches to the second position 23b due to the pilot pressure received from the pump P1. The first channel 13 is cut off, the supply channel 41 is connected to the extension side chamber R1, the pump P1 is active, and the compression side chamber R2 is connected to the shock absorber circuit C1 via the third channel 15. The buffer D7 with vehicle height adjustment function becomes the vehicle height adjustment mode, which lowers the vehicle height. When the pump P1 is driven in the forward direction and then stopped, the operating check valve OV is closed. High pressure is maintained between the operating check valve OV in the supply channel 41 and the switching valve V3. The switching valve V3 continues to select the second position 23b, so the buffer D7 with vehicle height adjustment function continues to maintain the vehicle height adjustment mode.

[0154] To restore the damper D7, which is in vehicle height adjustment mode, to shock absorber mode, pump P1 is reversed to open the operating check valve OV, releasing the pressure between switching valve V3 and operating check valve OV, and switching valve V3 is switched to the first position 23a. Thus, switching valve V3 selects the first position 23a, disconnecting the pump circuit PC and connecting the damper body 1 to the shock absorber circuit C1 via the first channel 13 and the third channel 15. Therefore, the connection between pump P1 and the extended side chamber R1 is broken, and the shock absorber circuit C1 is active, restoring the damper D7 with vehicle height adjustment function to shock absorber mode.

[0155] In this way, when the switching valve V3 selects the first position 23a, it switches to the second position 23b by rotating the pump P1 forward. When the second position 23b is selected, it switches to the first position 23a by rotating the pump P1 in reverse. Therefore, the buffer D7 with vehicle height adjustment function automatically switches the switching valve V3 by driving the pump P1 to switch to the shock absorber mode that only makes the shock absorber circuit C1 effective, and the vehicle height adjustment mode that makes the pump P1 effective and lowers the vehicle height.

[0156] Furthermore, when the buffer D7 with vehicle height adjustment function in the third embodiment is selected in shock absorber mode, the connection state between the buffer body 1 and the shock absorber circuit C1 in the buffer D6 with vehicle height adjustment function is the same as the connection state between the buffer body 1 and the shock absorber circuit C1 in the first embodiment with vehicle height adjustment function in shock absorber mode. Therefore, when the buffer D7 with vehicle height adjustment function in the third embodiment is selected in shock absorber mode, it exhibits the same operation as the buffer D1 with vehicle height adjustment function in the first embodiment in shock absorber mode, and when the buffer body 1 extends or retracts due to external force, a damping force that hinders the extension or retraction of the buffer body 1 occurs.

[0157] Next, the operation of the buffer D7 with vehicle height adjustment function, which is in vehicle height adjustment mode by selecting the second position 23b after the pump P1 is rotated forward, will be explained. In this state, hydraulic oil in the buffer D7 with vehicle height adjustment function is supplied from the pump P1 to the extension side chamber R1 of the buffer body 1. The connection state of the buffer body 1 and the shock absorber circuit C1 is the same as that in the first embodiment of the buffer D7 with vehicle height adjustment function in the vehicle height adjustment mode state. Therefore, the buffer D7 with vehicle height adjustment function in the third embodiment can automatically switch the switching valve V3 by driving the pump P1 to rotate forward, causing the buffer body 1 to contract and lower the vehicle height. After the vehicle height is lowered, when the pump P1 is stopped, hydraulic oil is no longer supplied from the pump P1 to the extension side chamber R1, but the switching valve V3 continues to be selected in the second position 23b, and the extension side chamber R1 is closed. On the other hand, the compression side chamber R2 is connected to the reservoir chamber R through the shock absorber circuit C1. Therefore, if the buffer D7 with vehicle height adjustment function causes the pump P1 to rotate forward and then stops it, the buffer body 1 is maintained in a retracted state by vehicle height adjustment.

[0158] Then, if pump P1 is reversed and switching valve V3 is switched to the first position 23a, making the buffer D7 with vehicle height adjustment function a shock absorber, the extension side chamber R1 is connected to the compression side chamber R2 and the reservoir R through the shock absorber circuit C1, allowing the buffer body 1 to extend. Therefore, the buffer body 1 uses the elastic force of the suspension spring S to return to the original displacement state before the vehicle height decreased.

[0159] As described above, the buffer D7 with vehicle height adjustment function in this embodiment is composed of the following parts: a buffer body 1, which has a cylinder 2 filled with hydraulic oil (liquid), a piston 3 movably inserted into the cylinder 2 and dividing the cylinder 2 into an extension side chamber R1 and a compression side chamber R2, and a piston rod 4 movably inserted into the cylinder 2 and connected to the piston 3; a suspension spring S, which applies force to the buffer body 1 in the extension direction; a reservoir R, which stores hydraulic oil (liquid); and a shock absorber return. The shock absorber circuit C1 is connected to the extension chamber R1, the compression chamber R2, and the reservoir R, and generates a damping force in the buffer body 1 when it extends or retracts; the pump P1 can draw in liquid from the reservoir R and discharge it; the switching valve V3 is located between the buffer body 1, the shock absorber circuit C1, and the pump P, and can switch between a shock absorber mode that connects the buffer body 1 to the shock absorber circuit C1 to generate a damping force in the buffer body 1, and a vehicle height adjustment mode that connects the buffer body 1 to the pump P1.

[0160] In this configuration of a shock absorber D7 with vehicle height adjustment, the damper circuit C1 and pump P1 can be selectively activated via the switching valve V3. Therefore, the reservoir R, which supplies excessive or insufficient hydraulic oil (liquid) to the cylinder 2 when the shock absorber body 1 generates damping force, can be used as a reservoir for storing hydraulic oil (liquid) supplied to the shock absorber body 1 during vehicle height adjustment. Furthermore, in this configuration of a shock absorber D7 with vehicle height adjustment, the pump P1 can be driven to supply hydraulic oil (liquid) to the shock absorber body 1 to extend, retract, or expand / contract, thus eliminating the need for a jack to drive the spring support of the suspension spring S.

[0161] As described above, the buffer D7 with vehicle height adjustment function, constructed in this way, eliminates the need for jacks and jack reservoirs required by conventional buffers with vehicle height adjustment function, thus enabling miniaturization even with vehicle height adjustment function.

[0162] Furthermore, in the buffer D7 with vehicle height adjustment function in this embodiment, in the vehicle height adjustment mode, the switching valve V3 connects the pump P to one of the extension side chamber R1 and the compression side chamber R2 of the buffer body 1, and connects the other of the extension side chamber R1 and the compression side chamber R2 to the reservoir chamber R via the shock absorber circuit C1. With the buffer D7 configured in this way, during vehicle height adjustment, the compressed chambers in the extension side chamber R1 and the compression side chamber R2 are connected to the reservoir chamber R via the shock absorber circuit C1. Therefore, there is no need for a channel connecting the compression side chamber and the reservoir chamber R solely for vehicle height adjustment, thus further miniaturization can be achieved.

[0163] Furthermore, in the buffer D7 with vehicle height adjustment function in this embodiment, the pump P1 can discharge bidirectionally, and the switching valve V3 uses the discharge pressure of the pump P1 as a pilot pressure to switch to the vehicle height adjustment mode. With this configuration, the buffer D7 with vehicle height adjustment function can automatically switch the switching valve V3 by driving the pump P1. Therefore, it can automatically switch between vehicle height adjustment mode and shock absorber mode by driving the pump P1, without needing to switch the switching valve V3 via a solenoid, thus reducing costs. The aforementioned pump circuit PC is only one example; any design change can be made as long as the discharge pressure of the pump P1 can be used as a pilot pressure to switch the switching valve V3. However, in the aforementioned pump circuit PC, when the pump P1 is rotated forward and then stopped, the switching valve V3 maintains the second position 23b, which can maintain the state of extending or retracting the buffer body 1. Therefore, it is not necessary to drive the pump P1 to maintain the state of extending or retracting the buffer body 1, thus reducing energy consumption.

[0164] Furthermore, if the vehicle height is to be lowered using the vehicle height adjustment mode, and the switching valve V1 is replaced with the switching valve V3 relative to the configuration of the buffer D4 with vehicle height adjustment function in the second embodiment, and pump P1 and pump circuit PC are installed instead of pump P, pump channel 20 and pump channel check valve 22, then the vehicle height can be lowered by switching the buffer with vehicle height adjustment function from shock absorber mode to vehicle height adjustment mode by rotating pump P1 in the forward direction, and the vehicle height can be restored from vehicle height adjustment mode to shock absorber mode by rotating pump P1 in the reverse direction thereafter. Furthermore, if the vehicle height is to be raised using the vehicle height adjustment mode, and if, relative to the configuration of the buffer D2 with vehicle height adjustment function in the first variation of the first embodiment or the buffer D5 with vehicle height adjustment function in the second embodiment, the switching valve V1 is changed to the switching valve V3, and the pump P1 and pump circuit PC are installed instead of the pump P, pump channel 20 and pump channel check valve 22, then the vehicle height can be raised by switching the buffer with vehicle height adjustment function from the shock absorber mode to the vehicle height adjustment mode by rotating the pump P1 forward, and the vehicle height can be restored from the vehicle height adjustment mode to the shock absorber mode by rotating the pump P1 in reverse.

[0165] In the configuration of the shock absorber circuit C1 in the buffer D7 with vehicle height adjustment function, the first connection point J1 between the first channel 13, which is equipped with a first extension-side damping valve 16 and a first extension-side check valve 17 in parallel, and the second channel 14, which is equipped with a first compression-side damping valve 18 and a first compression-side check valve 19 in parallel, is connected to the compression-side chamber R2. The end opposite to the first connection point J1 of the second channel 14 is connected to the reservoir R. Furthermore, the end opposite to the first connection point J1 of the first channel 13 is connected to the extension-side chamber R1.

[0166] Therefore, as shown in the buffer D7 with vehicle height adjustment function in this embodiment, a housing 5 is provided on the outer periphery of the cylinder 2, and when the annular gap 6 between the cylinder 2 and the housing 5 is connected to the elongated side chamber R1, the shock absorber circuit C1, the switching valve V3 and the liquid reservoir R can be arranged on the bottom side. Therefore, the shock absorber circuit C1, the switching valve V3 and the liquid reservoir R can be set on the cover 8 that closes the bottom of the cylinder 2 and the housing 5.

[0167] Specifically, for example, Figure 8 as well as Figure 9As shown, the cover 8 can be equipped with a shock absorber circuit C1, a switching valve V3, and a liquid storage chamber R. The cover 8 comprises: a cover body 60, which is a bottomed cylindrical shape and fits into the ends of the cylinder 2 and the outer casing 5; a first valve housing 61, which is cylindrical and connected to the side of the cover body 60; a liquid storage chamber cylinder 62, which is connected to the first valve housing 61; a second valve housing 63, which is cylindrical and connected to the side of the cover body 60 and the first valve housing 61; and a bracket 64, which is disposed at the axial end of the cover body 60 and can be connected to a vehicle body (not shown). Additionally, for ease of understanding, Figure 8 In the middle, cross-sections cut at different horizontal heights are used to display the cover body 60, the first valve housing 61, and the second valve housing 63. Furthermore, Figure 9 The first extension-side damping valve 16, the first extension-side check valve 17, the first compression-side damping valve 18, and the first compression-side check valve 19, which are housed in the first valve housing 61, are omitted from the diagram.

[0168] The cover body 60 is cylindrical with a bottom, and the outer periphery of the flange 2b of the cylinder 2 is fitted into its inner circumference. Furthermore, a threaded portion 5b provided on the outer periphery of the outer casing 5 is screwed onto the inner circumference of the cover body 60. The flange 2b of the cylinder 2 is clamped between the bottom of the outer casing 5 and the cover 8, and the cylinder 2 is fixed to the cover 8. Moreover, the cover body 60 closes the bottom end of the cylinder 2 and the outer casing 5. This structure fastening the cover 8 to the cylinder 2 and the outer casing 5 is only one example; other fastening structures may also be used. In addition, the cover body 60 has a bottom spring support 60a composed of an annular stepped portion provided on the outer periphery of the cylinder side.

[0169] The first valve housing 61 is cylindrical and integrally connected to the side of the cover body 60. It is positioned on a plane orthogonal to the axis of the damper body 1 and has a centerline at a point where it is bent relative to the axis. The center of the first valve housing 61 communicates with the compression side chamber R2 in the cylinder 2 through a port 60b provided on the cover body 60. The port 60b functions as a third channel in the shock absorber circuit C1. The first valve housing 61 houses a first extension-side damping valve 16, a first extension-side check valve 17, a first compression-side damping valve 18, and a first compression-side check valve 19.

[0170] On the other hand, the liquid storage chamber 62 is positioned parallel to the buffer body 1 and is aligned with the first valve housing 61. Figure 8 It is connected to the left side of the middle section. In addition, the liquid storage chamber cylinder 62... Figure 9The lower end of the reservoir is sealed by a plug 65, making the reservoir 62 airtight. A diaphragm 66, filled with compressed gas and mounted on the plug 65, is inserted into the reservoir 62, dividing the reservoir 62 into a gas chamber G inside the diaphragm 66 and a liquid chamber L filled with hydraulic oil outside the diaphragm 66. Furthermore, the upper liquid chamber L inside the reservoir 62 communicates with the left side of the first valve housing 61 via a port 62a. Port 62a functions as part of the second channel in the shock absorber circuit C1. Additionally, the reservoir 62... Figure 9 The upper middle part is provided with a port 62b, which connects the liquid chamber L to the suction channel 44 of the pump circuit PC located outside the liquid storage chamber cylinder 62. In addition, the plug 65 is provided with a valve (not shown) that can inject gas into the diaphragm 66. After the diaphragm 66 is inserted into the liquid storage chamber cylinder 62, gas can be injected. The pressure in the gas chamber G can also be adjusted through the valve.

[0171] Furthermore, the second valve housing 63 is a bottomed cylindrical shape with an open rear end. It is integrated with the side of the cover body 60 and the first valve housing 61 from the side to the front end. It is located on a plane orthogonal to the axis of the damper body 1 and on which the first valve housing 61 is disposed, and has a centerline at a position orthogonal to the centerline of the first valve housing 61 and curved relative to the axis of the damper body 1. The interior of the second valve housing 63 is connected to the annular gap 6 between the cylinder 2 and the housing 5 through a channel 60c provided on the cover body 60 and a hole 5a provided on the housing 5. It is also connected to the right side of the first valve housing 61 through a port 63a provided at the front end. Furthermore, it is connected to the outside through a port 63b provided at the rear end of the second valve housing 63 relative to the channel 60c. The annular gap 6 between the cylinder 2 and the housing 5, the hole 5a, the channel 60c, and the port 63a constitute the first channel in the shock absorber circuit C1. The channel 60c and the port 63a function as port a and port t, respectively. In addition, port 63b functions as port p of switching valve V3 and is connected to supply channel 41 in pump circuit PC.

[0172] The cover 8 is configured as described above. As previously mentioned, the first valve housing 61 contains a first extension-side damping valve 16, a first extension-side check valve 17, a first compression-side damping valve 18, and a first compression-side check valve 19, and the second valve housing 63 contains a switching valve V3.

[0173] First valve body 61 Figure 8A plug component 67 is screwed onto the inner circumference of the left end of the first valve housing 61, the plug component 67 sealing the left end opening of the first valve housing 61. The plug component 67 has a shaft 67a protruding into the first valve housing 61, and the outer circumference of the shaft 67a is fitted with: a partition component 68, the partition component 68 being annular; and a first compression-side damping valve 18, the first compression-side damping valve 18 consisting of components stacked on the partition component 68. Figure 8 The left side consists of an annular stacked vane valve; the first compression-side check valve 19 is composed of valves stacked on the partition member 68. Figure 8 The system comprises an annular plate on the right side and a spring member that applies force to the annular plate toward the partition member 68. Furthermore, the partition member 68 abuts against the inner circumference of the first valve housing 61, dividing the first valve housing 61 into a space communicating with the liquid chamber L via port 62a and a space communicating with the compression-side chamber R2 via port 60b. In addition, the partition member 68 has ports 68a and 68b extending axially through the partition member 68, through which the partition member 68... Figure 8 The space on the left and right sides of the middle section is connected.

[0174] The inner circumference of the first compression-side damping valve 18 is fixed to the shaft 67a of the plug component 67, allowing bending of the outer circumference, and is stacked on the partition component 68 to open and close the outlet end of the port 68a. Moreover, for hydraulic oil flow from the compression-side chamber R2 through the port 68a to the reservoir R, the first compression-side damping valve 18 bends its outer circumference to open the valve, apply resistance and allow the flow, but for hydraulic oil flow on the opposite side, it closes the port 68a and maintains that position.

[0175] The annular plate in the first compression-side check valve 19 is slidably mounted on the outer periphery of the shaft 67a of the plug component 67, opening and closing the outlet end of the port 68b. Moreover, for hydraulic oil flow from the reservoir R through the port 68b to the compression-side chamber R2, the first compression-side check valve 19 opens by moving the annular plate away from the separator 68 with almost no resistance and allows the flow, but for hydraulic oil flow on the opposite side, it closes the port 68b and maintains that position.

[0176] First valve body 61 Figure 8 A plug component 69 is screwed onto the inner circumference of the right end of the first valve housing 61, the plug component 69 sealing the right end opening. The plug component 69 has a shaft 69a protruding into the first valve housing 61, and the outer circumference of the shaft 69a is fitted with: a partition component 70, the partition component 70 being annular; and a first extension-side damping valve 16, the first extension-side damping valve 16 being composed of components stacked on the partition component 70. Figure 8 The right side of the middle part consists of an annular stacked blade valve; the first extended side check valve 17, the first extended side check valve 17 is composed of stacked blades on the partition member 70. Figure 8The valve consists of an annular plate on the left side and a spring component that applies force to the annular plate towards the partition member 70. Furthermore, the partition member 70 abuts against the inner circumference of the first valve housing 61, dividing the first valve housing 61 into a space communicating with port 63a and a space communicating with port 60b. The partition member 70... Figure 8 The right-hand space is connected to the elongated side chamber R1 through port 63a, inside the second valve housing 63, channel 60c, and the annular gap 6 between cylinder 2 and outer casing 5, separating the component 70. Figure 8 The space on the left side is connected to the compression-side chamber R2 via port 60b. Furthermore, the partition member 70 has ports 70a and 70b extending axially through the partition member 70, through which the partition member 70... Figure 8 The space on the left and right sides of the middle section is connected.

[0177] The inner circumference of the first elongation-side damping valve 16 is fixed to the shaft 69a of the plug component 69, allowing bending of the outer circumference, and is stacked on the separator component 70 to open and close the outlet end of the port 70a. Moreover, for hydraulic oil flow from the elongation-side chamber R1 through the port 70a to the compression-side chamber R2, the first elongation-side damping valve 16 causes the outer circumference to bend to open the valve, applying resistance and allowing the flow, but for hydraulic oil flow on the opposite side, it closes the port 70a and maintains that position.

[0178] The annular plate in the first elongation-side check valve 17 is slidably mounted on the outer periphery of the shaft 69a of the plug component 69, opening and closing the outlet end of the port 70b. Furthermore, for hydraulic oil flow from the reservoir R or the compression-side chamber R2 through port 70b to the elongation-side chamber R1, the first elongation-side check valve 17 opens by moving the annular plate away from the separator 70 with almost no resistance and allows the flow; however, for hydraulic oil flow on the opposite side, it closes port 70b and maintains that position.

[0179] Second valve body 63 Figure 8 A plug component 71 is screwed onto the inner circumference of the upper part of the second valve housing 63, which closes the upper opening of the second valve housing 63. Furthermore, the second valve housing 63 contains: a sleeve 72, which is cylindrical; a valve body 73, which is a bottomed cylindrical shape and can be slidably inserted into the sleeve 72; and a spring 74, which is inserted between the sleeve 72 and the valve body 73, applying force to the valve body 73 against the plug component 71. Moreover, the sleeve 72, the valve body 73, and the spring 74 constitute a switching valve V3, which is housed within the second valve housing 63.

[0180] The inner diameter of sleeve 72 is from Figure 8 The middle and lower end, i.e., the front end Figure 8The upper middle section, i.e., the rear end side, has two stages of diameter expansion, and its inner circumference has two stepped portions 72a and 72b, so that the outer circumference of the rear end fits into the inner circumference of the second valve housing 63, i.e., it fits into the rear end side relative to the channel 60c, and the front end abuts against the bottom of the front end of the second valve housing 63. Furthermore, the sleeve 72 has a hole 72c on the rear end side of the stepped portion 72b relative to the rear end side, through which the sleeve 72 communicates with the channel 60c and the port 63a. Moreover, a sealing ring 75 is installed on the outer circumference of the rear end side of the sleeve 72, which is tightly fitted between the opening of the channel 60c and the opening of the port 63b on the inner circumference of the second valve housing 63, preventing the channel 60c from communicating with the port 63b without passing through the sleeve 72. Additionally, the plug component 71 that closes the opening of the second valve housing 63 has a socket 71a, which is fitted into the inner circumference of the rear end of the sleeve 72 and has a hole 71b, through which the sleeve 72 is connected to the port 63b.

[0181] The valve body 73 is a bottomed cylindrical shape with a flange 73a on its outer periphery. The flange 73a has an opening near its opening that makes sliding contact with the stepped portions 72a and 72b of the inner periphery of the sleeve 72. The outer periphery of the flange 73a also makes sliding contact with the inner periphery of the sleeve 72, specifically with the rear end of the stepped portion 72b. Furthermore, a hole 73b is provided on the side of the valve body 73 opposite to the opening of the flange 73a.

[0182] The valve body 73 can move in the direction of entering the sleeve 72 until the flange 73a abuts against the stepped portion 72b of the sleeve 72, and conversely, it can move in the direction of exiting the sleeve 72 until the flange 73a abuts against the socket 71a of the plug component 71.

[0183] Furthermore, at the position where the flange 73a abuts against the step portion 72b, the hole 73b is closed by the inner circumference of the sleeve 72, so the valve body 73 disconnects the communication between the channel 60c and the port 63a, but on the other hand, it connects the hole 72c of the sleeve 72 with the port 63b of the second valve housing 63. Additionally, when the flange 73a is away from the step portion 72b and abuts against the socket 71a of the plug member 71, the valve body 73 disconnects the communication between the port 63a and the port 63b through the abutment between the flange 73a and the socket 71a, but on the other hand, it aligns the hole 73b with the hole 72c of the sleeve 72 to connect the channel 60c with the port 63a.

[0184] Furthermore, a spring 74, composed of helical springs, is inserted in a compressed state between the open end of the valve body 73 and the stepped portion 72a of the sleeve 72. The spring 74 constantly applies force to the valve body 73 against the plug component 71. When the pressure in the space between the valve body 73 and the plug component 71, which communicates with port 63b, is low, the valve body 73 is positioned where the flange 73a abuts against the socket 71a of the plug component 71. In this state, as previously described, the connection between port 63a and port 63b is broken through the abutment of the flange 73a and socket 71a. As previously described, port 63b is connected to the pump circuit PC, so the connection between the pump circuit PC and the extended side chamber R1 is broken. However, on the other hand, the shock absorber circuit C1 is connected to the extended side chamber R1 through the connection between the channel 60c and port 63a. That is, in this state, the switching valve V3 selects the first position.

[0185] With the switching valve V3 in the first position, when the pump P1 is driven to rotate forward, hydraulic oil is supplied from the pump P1 through port 63b into the space between the valve body 73 and the plug component 71. The valve body 73 compresses the spring 74, the flange 73a abuts against the step portion 72b, and the port 63b communicates with the channel 60c, supplying hydraulic oil from the pump P1 to the extended side chamber R1. In this state, the connection between the port 63a forming the first channel and the channel 60c is broken by the abutment between the flange 73a and the step portion 72b, thus disconnecting the extended side chamber R1 from the shock absorber circuit C1. That is, the switching valve V3 switches from the first position to the second position.

[0186] Furthermore, when the switching valve V3 selects the second position and stops driving the pump P1, the operating check valve OV in the pump circuit PC closes, so the space between the valve body 73 and the plug component 71 remains under high pressure, maintaining the state where the flange 73a of the valve body 73 abuts against the stepped portion 72b of the sleeve 72, and the switching valve V3 continues to maintain the second position.

[0187] Then, with the switching valve V3 maintained in the second position, when the pump P1 is reversed, the reverse rotation of pump P1 opens the check valve OV, allowing hydraulic oil to be discharged from the space between the valve body 73 and the plug component 71 through port 63b. Therefore, the valve body 73 is pushed by the force of the spring 74, causing the flange 73a to abut against the socket 71a of the plug component 71, disconnecting the connection between port 63b and channel 60c, and connecting port 63a, which forms the first channel, to channel 60c. Thus, the switching valve V3 returns from the second position to the first position, disconnecting the extension chamber R1 from the pump circuit PC, and connecting the extension chamber R1 to the shock absorber circuit C1.

[0188] When the switching valve V3 is in the first position, the shock absorber circuit C1 is connected to the extension-side chamber R1 via port 63a and channel 60c, which function as the first channel. The shock absorber circuit C1 is always connected to the compression-side chamber R2 via port 60b, which functions as the third channel. In this state, when the buffer body 1 extends, the hydraulic oil pushed out from the extension-side chamber R1 moves through the first extension-side damping valve 16 to the enlarged compression-side chamber R2, therefore... Figure 8 as well as Figure 9 The buffer D7 with vehicle height adjustment function shown generates an extension-side damping force that resists the extension of the buffer body 1 when it extends. Furthermore, in this state, when the buffer body 1 retracts, hydraulic oil pushed out from the compression-side chamber R2 moves through port 60b and the first compression-side damping valve 18 to the reservoir R, and then moves via the first extension-side check valve 17 to the enlarged extension-side chamber R1. Therefore, Figure 8 as well as Figure 9 The buffer D7 shown has a vehicle height adjustment function. When the buffer body 1 retracts, it generates an elongation-side damping force that hinders the retraction of the buffer body 1.

[0189] On the other hand, when pump P1 is rotated forward and switching valve V3 is switched to the second position, pump circuit PC is connected to the extension side chamber R1 through port 63b and channel 60c, and the connection between shock absorber circuit C1 and the extension side chamber R1 is disconnected. Therefore, the hydraulic oil supplied from pump P1 to the extension side chamber R1 causes the damper body 1 to contract, thus lowering the vehicle height. When pump P1 is stopped, the damper body 1 remains in the contracted state, maintaining the state of lowering the vehicle height. Then, if pump P1 is reversed for a very short time, switching valve V3 returns to the first position, and damper body 1 extends using the elastic force of suspension spring S until it reaches the vehicle height before it lowers.

[0190] In this way, even Figure 8 as well as Figure 9 The damper D7 with vehicle height adjustment function, when the vehicle height adjustment mode is selected, causes the damper body 1 to retract by rotating the pump P1 in the forward direction, thus lowering the vehicle height. Alternatively, to raise the vehicle height in vehicle height adjustment mode, a second valve housing 63 is positioned midway between the port 60b connecting the partition member 68, partition member 70, and compression chamber R2 within the first valve housing 61, eliminating port 63a. The channel 60c is then connected to the space on the left side of the first valve housing 61 relative to the partition member 68, ensuring that the shock absorber circuit C1 is always connected to the extension chamber R1. With this configuration, the damper with vehicle height adjustment function has the same circuit configuration as the damper D2 with vehicle height adjustment function, thus allowing the vehicle height to be raised in vehicle height adjustment mode.

[0191] Furthermore, when using a shock absorber circuit C2 with buffers D3 and D4 that have vehicle height adjustment function, a housing 5 is provided on the outer periphery of the cylinder 2, so that the annular gap 6 between the cylinder 2 and the housing 5 is connected to the elongated side chamber R1. In this case, the shock absorber circuit C2, the switching valve V3 and the liquid reservoir R can also be arranged on the bottom side. Therefore, the shock absorber circuit C2, the switching valve V3 and the liquid reservoir R can be set on the cover 8 that closes the bottom of the cylinder 2 and the housing 5.

[0192] Alternatively, if space permits, the pump circuit PC, pump P1, and motor 21 can be integrated with the cover 8. An example with shock absorber circuits C1 and C2, switching valve V3, and liquid storage chamber R on the cover 8 has been described, but the solenoid switching valve, i.e., switching valve V1, can also be installed on the cover 8 instead of switching valve V3. In this case, the pump passage 20, motor 21, pump passage check valve 22, and pump P can also be integrated with the cover 8.

[0193] Moreover, as mentioned above, the buffer body 1 includes: a housing 5, which covers the outer periphery of the cylinder 2 and forms an annular gap 6 between the housing 5 and the cylinder 2, communicating with the elongated side chamber R1; and a cover 8, which closes one end of the cylinder 2 and one end of the housing 5. When the liquid reservoir R, the shock absorber circuits C1, C2, and the switching valves V1, V3 are mounted on the cover 8, the liquid reservoir R, the shock absorber circuits C1, C2, and the switching valves V3 can be integrated onto the cover 8. Therefore, the buffer body 1 is easy to assemble and can be connected to the liquid reservoir R, the shock absorber circuits C1, C2, and the switching valves V1, V3 from the outside of the buffer body 1. Thus, maintenance and debugging are also convenient.

[0194] Furthermore, the first extension-side damping valve 16 and the first compression-side damping valve 18 (the second extension-side damping valve 34 and the second compression-side damping valve 36) in the shock absorber circuit C1 (C2) can also be valves with adjustable damping force. By providing these first extension-side damping valves 16 and first compression-side damping valves 18 (the second extension-side damping valves 34 and the second compression-side damping valves 36) on the cover 8, the damping force can be easily adjusted. In this way, the first extension-side damping valve 16, the first compression-side damping valve 18, the second extension-side damping valve 34, and the second compression-side damping valve 36 in the buffers D1, D2, D3, D4, D5, D6, and D7 with vehicle height adjustment function can also be damping valves with adjustable damping force, or they can be solenoid valves using solenoids.

[0195] Furthermore, when the first elongation-side damping valve 16, the first elongation-side check valve 17, the first compression-side damping valve 18, and the first compression-side check valve 19 (the second elongation-side damping valve 34, the second elongation-side check valve 35, the second compression-side damping valve 36, and the second compression-side check valve 37) in the shock absorber circuit C1 (C2) are housed within a single cylindrical first valve housing 61, the structure of the cover 8 does not need to be complex, and the setting of the third channel (sixth channel) is also convenient. Furthermore, the assembly of the shock absorber circuits C1 and C2 can be completed simply by inserting the plug components 67 that hold the first extension-side damping valve 16 and the first extension-side check valve 17 (the second extension-side damping valve 34 and the second extension-side check valve 35) and the plug components 69 that hold the first compression-side damping valve 18 and the first compression-side check valve 19 (the second compression-side damping valve 36 and the second compression-side check valve 37) face-to-face into the openings on both ends of the first valve housing 61, respectively. Therefore, the assemblability is also good. Alternatively, the first valve housing 61 can also be a bottomed cylindrical shape. In this case, the following structure can be used: a plug component is screwed into the opening of the first valve housing 61, and a first extension-side damping valve 16, a separator component 68, a first extension-side check valve 17, a first compression-side damping valve 18, a separator component 70, and a first compression-side check valve 19 (a second extension-side damping valve 34, a separator component 68, a second extension-side check valve 35, a second compression-side damping valve 36, a separator component 70, and a second compression-side check valve 37) are mounted on a shaft portion provided on the plug component. Furthermore, the first valve housing 61 can also be composed of a first cylinder and a second cylinder, with the first cylinder housing the first extension-side damping valve 16 and the first extension-side check valve 17 (a second extension-side damping valve 34 and a second extension-side check valve 35), and the second cylinder housing the first compression-side damping valve 18 and the first compression-side check valve 19 (a second compression-side damping valve 36 and a second compression-side check valve 37).

[0196] The preferred embodiments of the present invention have been described in detail above, but modifications, variations and alterations can be made without departing from the scope of the claims.

[0197] Symbol Explanation

[0198] 1. Buffer body

[0199] 2 cylinders

[0200] 3 Pistons

[0201] 4 Piston rod

[0202] 5. Outer shell

[0203] 6. Annular gap

[0204] 8 lids

[0205] 9. Pressure relief channels

[0206] Pressure reducing valves 10, 101, and 102

[0207] 13 First Passage

[0208] 14 Second Channel

[0209] 15 Third Channel

[0210] 16 First elongation side damping valve

[0211] 17 First extension side check valve

[0212] 18 First compression-side damping valve

[0213] 19 First compression side check valve

[0214] 31 Fourth Channel

[0215] 32 Fifth Channel

[0216] 33 Sixth Channel

[0217] 34 Second extension side damping valve

[0218] 35 Second extension side check valve

[0219] 36 Second compression side damping valve

[0220] 37 Second compression side check valve

[0221] 23a First position

[0222] 23b Second position

[0223] 26a Left position

[0224] 26b Neutral position

[0225] 26c Right position

[0226] C1, C2 shock absorber circuits

[0227] D1, D2, D3, D4, D5, D6, and D7 are buffers with vehicle height adjustment function.

[0228] P, P1 pumps

[0229] R reservoir

[0230] R1 elongated side chamber

[0231] R2 compression side chamber

[0232] S suspension springs

[0233] V1, V2, V3 switching valve

Claims

1. A buffer with vehicle height adjustment function, comprising: The buffer body has a cylinder filled with liquid, a piston movably inserted into the cylinder and dividing the cylinder into an extension side chamber and a compression side chamber, and a piston rod movably inserted into the cylinder and connected to the piston. A suspension spring that applies a force to the buffer body along its extension direction; A liquid storage chamber is used to store liquid. A shock absorber circuit is connected to the extension side chamber, the compression side chamber, and the liquid reservoir, and generates a damping force in the buffer body when the buffer body extends or retracts. A pump that can draw liquid from the storage chamber and discharge it; A switching valve is disposed between the buffer body, the shock absorber circuit, and the pump, and can switch between a shock absorber mode that connects the buffer body to the shock absorber circuit to generate damping force in the buffer body, and a vehicle height adjustment mode that connects the buffer body to the pump. The reservoir chamber, in the shock absorber mode, supplies excess or insufficient liquid to the cylinder, and in the vehicle height adjustment mode, functions as a reservoir for storing liquid supplied to the buffer body by driving the pump.

2. The buffer with vehicle height adjustment function as described in claim 1, characterized in that, In the vehicle height adjustment mode, the switching valve connects the pump to one of the elongation side chamber and the compression side chamber of the shock absorber body, and connects the other of the elongation side chamber and the compression side chamber to the reservoir via the shock absorber circuit.

3. The buffer with vehicle height adjustment function as described in claim 1 or 2, wherein, The shock absorber circuit has: A first channel, one end of which is connected to the elongated side chamber; A second channel connects the other end of the first channel to the liquid storage chamber; The third channel connects the connection point between the first channel and the second channel, i.e., the first connection point, to the compression side chamber. A first elongation-side damping valve is disposed on the first channel and applies resistance to the liquid flow from the elongation-side chamber to the first connection point; The first extension-side check valve is connected in parallel with the first extension-side damping valve on the first channel and only allows liquid flow from the first connection point to the extension-side chamber. A first compression-side damping valve is disposed on the second channel and applies resistance to the liquid flow from the first connection point to the liquid storage chamber. A first compression-side check valve is connected in parallel with a first compression-side damping valve on the second channel, and only allows liquid flow from the reservoir to the first connection point.

4. The buffer with vehicle height adjustment function as described in claim 1 or 2, wherein, The shock absorber circuit has: A fourth channel, one end of which is connected to the elongated side chamber; The fifth channel connects the compression-side chamber to the other end of the fourth channel; The sixth channel connects the connection point between the fourth and fifth channels, i.e., the second connection point, to the liquid storage chamber; A second extension-side damping valve is disposed on the fourth channel and applies resistance to the liquid flow from the extension-side chamber to the second connection point; The second extension-side check valve, which is connected in parallel with the second extension-side damping valve on the fourth channel, only allows liquid flow from the second connection point to the extension-side chamber. A second compression-side damping valve is disposed on the fifth channel and applies resistance to the liquid flow from the compression-side chamber to the second connection point; The second compression-side check valve, which is connected in parallel with the second compression-side damping valve on the fifth channel, only allows liquid flow from the second connection point to the compression-side chamber.

5. The buffer with vehicle height adjustment function as described in claim 3, wherein, The switching valve The system includes a position in the shock absorber mode where the first channel is connected and the pump is disconnected from the buffer body, and a position in the vehicle height adjustment mode where the first channel is disconnected and the pump is connected to the buffer body. Alternatively, it may have a position in the shock absorber mode where the third channel is connected and the pump is disconnected from the buffer body, and a position in the vehicle height adjustment mode where the third channel is disconnected and the pump is connected to the buffer body. Alternatively, two positions can be selectively selected: in the shock absorber mode, the position where the first channel is connected to the third channel and the pump is disconnected from the buffer body; and in the vehicle height adjustment mode, the position where the first channel is cut off and the pump is connected to the buffer body, and the position where the third channel is cut off and the pump is connected to the buffer body.

6. The buffer with vehicle height adjustment function as described in claim 4, wherein, The switching valve The system includes a position in the shock absorber mode where the fourth channel is connected and the pump is disconnected from the buffer body, and a position in the vehicle height adjustment mode where the fourth channel is disconnected and the pump is connected to the buffer body. Alternatively, it may have a position in the shock absorber mode where the fifth channel is connected and the pump is disconnected from the buffer body, and a position in the vehicle height adjustment mode where the fifth channel is disconnected and the pump is connected to the buffer body. Alternatively, two positions can be selectively selected: in the shock absorber mode, the position where the fourth channel is connected to the fifth channel and the pump is disconnected from the buffer body; and in the vehicle height adjustment mode, the position where the fourth channel is disconnected and the pump is connected to the buffer body, and the position where the fifth channel is disconnected and the pump is connected to the buffer body.

7. The buffer with vehicle height adjustment function as described in claim 1, wherein, The pump can discharge in both directions. The switching valve uses the pump's discharge pressure as a pilot pressure to switch to the vehicle height adjustment mode.

8. The buffer with vehicle height adjustment function as described in claim 1, wherein, The buffer body has: A pressure relief channel connects the elongated side chamber to the compressed side chamber; A pressure reducing valve is provided on the pressure relief channel and opens after the differential pressure between the elongation side chamber and the compression side chamber reaches the valve opening pressure.

9. The buffer with vehicle height adjustment function as described in claim 1, wherein, The buffer body has: A housing that covers the outer periphery of the cylinder and forms an annular gap between the housing and the cylinder that communicates with the elongated side chamber; A cover that seals one end of the cylinder and one end of the housing. The liquid storage chamber, the shock absorber circuit, and the switching valve are mounted on the cover.

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