JP4832943B2 - Vehicle suspension system - Google Patents

Description

  The present invention relates to a vehicle suspension apparatus that changes a vehicle body posture by extending and contracting a cushion unit using a fluid cylinder.

Conventionally, in the above suspension device, there is one in which a fluid cylinder is provided at an end of a rod on the vehicle body side of a damper provided in a cushion unit (see, for example, Patent Document 1).
Japanese Utility Model Publication No. 6-67942

By the way, in the said conventional structure, there exists a subject of increasing a cushion unit length and reducing a vehicle body mounting freedom degree. On the other hand, it is conceivable that the fluid cylinder is provided inside the coil spring provided in the cushion unit and on the outer periphery of the rod. However, in this configuration, the damper stroke is likely to be sacrificed, and as a result, the length of the cushion unit is increased. Issues remain.
Therefore, the present invention provides a vehicle suspension device that can be provided with a fluid cylinder for expansion and contraction while suppressing the length of the cushion unit.

As a means for solving the above problems, the invention described in claim 1 is a damper (for example, damper 5 of the embodiment) that is disposed between a vehicle body and a wheel and cushions the vertical movement of the wheel with respect to the vehicle body, and the damper. A coil spring (e.g., coil spring 6 of the embodiment) that is provided substantially coaxially and receives a relative load between the vehicle body and the wheel, and an upper spring seat and a lower spring seat (e.g., implementation) that support upper and lower ends of the coil spring. In a vehicle suspension device (for example, the vehicle suspension devices 1, 101, 201, 301 of the embodiment) provided with the upper spring seat 11 and the lower spring seat 12 of the example, the lower spring seat is a cylinder of the damper ( For example, the damper cylinder 7) of the embodiment is arranged on the outer periphery and the cylinder The lower spring seat constitutes a fluid cylinder (for example, the hydraulic cylinders 13, 113, 313 of the embodiment) on the outer peripheral side of the cylinder, and the fluid flows to the fluid cylinder. By being pumped and discharged, the lower spring seat moves in the axial direction with respect to the damper, and the fluid cylinder is in sliding contact with the piston rod (for example, the piston rod 8 in the embodiment) on the axial upper side of the damper. And a cylinder outer (for example, cylinder outers 15 and 115 in the embodiment) slidably contacting the cylinder on the lower side in the axial direction of the damper. The cylinder outer is formed between the inner surface of the cylinder outer and the outer surfaces of the cylinder and the piston rod. An oil chamber (for example, the oil chamber 16 of the embodiment) is formed between them, and the fluid in the oil chamber is allowed to flow in and out. It characterized by having a hydraulic inflow and outflow ports (e.g. main hydraulic inflow and outflow ports 18 in the embodiment).

The invention described in claim 2 is characterized in that the lower spring seat is provided across the outer periphery of the cylinder and the outer periphery of the piston rod in the damper.

According to the third aspect of the present invention, a coil (for example, 249 of the embodiment) coaxial with the cylinder outer is disposed inside the cylinder outer , and the coil detects a stroke amount of the fluid cylinder (for example, the sensor of the embodiment). 248).

According to the present invention , by providing the fluid cylinder on the outer periphery of the cylinder of the damper, the damper stroke is not sacrificed, and the damper length and the cushion unit length can be suppressed to improve the degree of freedom for mounting on the vehicle body. Further, by providing the fluid cylinder on the outer periphery of the cylinder having a relatively large diameter in the damper, it is possible to reduce the size and weight of the fluid cylinder structure by effectively utilizing the cylinder rigidity.

According to the present invention , it is possible to efficiently increase the rigidity of a damper against a lateral force (a force from a direction intersecting the axial direction, a stabilizer reaction force, etc.) without sacrificing the damper stroke. At this time, the rod outer peripheral surface which is a seal sliding surface in the damper can be effectively used as a seal sliding surface of the fluid cylinder.

According to the present invention , by using the cylinder outer of the lower spring seat as a part of the sensor, the cushion unit can be reduced in size and weight and cost can be reduced as compared with the case where a separate sensor is externally attached to the fluid cylinder. Can do.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a vehicle suspension device (hereinafter, simply referred to as a suspension device) 1 of this embodiment. The suspension device 1 includes right and left cushion units 2 respectively disposed at the left and right front wheels or the rear wheel positions, a hydraulic circuit 4 disposed between the cushion units 2 and controlling them, and a vehicle body roll for controlling the rolls of the vehicle body. And a stabilizer 41 for applying a spring reaction force to the cushion unit 2. Hereinafter, the left and right cushion units 2 may be referred to as 2L and 2R, respectively.

  The cushion unit 2 is formed by integrally combining, for example, a hydraulic cylinder type damper 5 and a coil spring 6 arranged so as to be wound around the cylinder unit, and the axial direction (longitudinal direction) of the cushion unit 2 in the vehicle mounted state is, for example, the vertical direction. It is arranged along. Note that a line C in the figure indicates an axis (cushion axis) along the axial direction of the cushion unit 2 (also the axial direction of the damper 5).

  The damper 5 is arranged so that a cylindrical damper cylinder 7 is positioned on the lower side and a piston rod 8 is positioned on the upper side. The piston rod 8 extends upward from a piston (not shown) that slides in the damper cylinder 7, and exhibits a damping force due to the viscous resistance of oil in the damper cylinder 7 during the stroke. The outer peripheral surface of the piston rod 8 is a sliding surface with the seal on the inner periphery of the upper end of the damper cylinder 7.

  An upper spring seat 11 that supports the upper end of the coil spring 6 is attached to the upper portion of the piston rod 8. On the other hand, a lower spring seat 12 that supports the lower end of the coil spring 6 is attached to the upper portion of the damper cylinder 7 via a hydraulic cylinder (elevating actuator) 13 described in detail later.

  By holding the coil spring 6 so as to be sandwiched between the spring seats 11 and 12, the coil spring 6 can be expanded and contracted together with the damper 5. An upper end portion (upper end portion of the cushion unit 2) of the piston rod 8 is a connecting portion 8a to the vehicle body side, and a lower end portion (lower end portion of the cushion unit 2) of the damper cylinder 7 is a connecting portion 7a to the wheel side. That is, the upper spring seat 11 is connected to the vehicle body side, and the lower spring seat 12 is connected to the wheel side.

  By providing such cushion units 2 at the left and right wheel positions of the vehicle body, the relative vertical movement between the vehicle body and the wheels is elastically received by the coil spring 6, and the expansion and contraction energy of the coil spring 6 is reduced by the damper 5. Is attenuated by In other words, the load from the road surface or the roll of the vehicle body is gently absorbed by the cooperation of the coil spring 6 and the damper 5.

  Referring also to FIG. 2, the hydraulic cylinder 13 that supports the lower spring seat 12 is provided so as to be coaxial with the damper 5 and surround the outer periphery thereof. The hydraulic oil is pumped and discharged from the hydraulic cylinder 13. Thus, the cylinder outer 15 constituting the outer shell is movable up and down (can be raised and lowered) with respect to the damper 5. A flange-like lower spring seat 12 is integrally provided on the outer periphery of the lower portion of the cylinder outer 15. Hereinafter, an integral structure composed of the cylinder outer 15 and the lower spring seat 12 may be referred to as a movable lower spring seat 12A.

  The cylinder outer 15 (hydraulic cylinder 13) is provided across the outer periphery of the damper cylinder 7 and the outer periphery of the piston rod 8, and has a bottomed cylindrical shape that covers the upper end portion of the damper cylinder 7 from above. At the center of the side end portion, a vehicle body side seal portion 15a that penetrates the piston rod 8 and slidably contacts the outer peripheral surface of the piston rod 8 projects upward (upper spring seat 11 side).

  In addition, a wheel side seal portion 15b is provided on the inner periphery of the lower end portion (wheel side end portion) of the cylinder outer 15 so that the seal is slidably brought into contact with the outer peripheral surface of the damper cylinder 7 penetrating vertically. A predetermined gap is formed between the inner surface of the cylinder outer 15 and the outer surface of the damper 5, and the gap portion forms an oil chamber 16 in the hydraulic cylinder 13. A main hydraulic inflow / outflow port 18 communicating with the oil chamber 16 is provided immediately below the lower spring seat 12 in the cylinder outer 15.

The hydraulic circuit 4 communicates the oil chambers 16 of the hydraulic cylinders 13 in the left and right cushion units 2L and 2R via a gear pump (hydraulic pump) 20 that can rotate forward and backward.
The gear pump 20 rotates the driving gear 22 disposed in the housing 21 and the driven gear 23 meshing with the driving gear 22, and the hydraulic oil sucked from one of the auxiliary hydraulic inlet / outlet ports 24 provided on both sides of the cylinder outer 15. Discharge (pressure feed) at a predetermined pressure toward A motor 22a that is a drive source of the drive gear 22 is driven and controlled by an ECU (electric control unit) (not shown).

  For example, the right sub hydraulic flow port 24 in the gear pump 20 is connected to the main hydraulic flow port 18 of the hydraulic cylinder 13 in the right cushion unit 2R via a hydraulic pipe 27. On the other hand, for example, the left auxiliary hydraulic flow port 24 in the gear pump 20 is connected to the main hydraulic flow port 18 of the hydraulic cylinder 13 in the left cushion unit 2L via a hydraulic pipe 27.

  When the drive shaft is rotationally driven by the motor 22a, the hydraulic oil in the oil chamber 16 of the hydraulic cylinder 13 in one cushion unit 2 is supplied to the oil in the hydraulic cylinder 13 in the other cushion unit 2 via the hydraulic circuit 4. The lower spring seat 12 (movable lower spring seat 12A) in the one cushion unit 2 is lowered and the lower spring seat 12 (movable lower spring seat 12A) in the other cushion unit 2 is raised. Let

Each hydraulic pipe 27 is connected to a hydraulic supply pipe 31 that can supply or discharge hydraulic pressure to both hydraulic cylinders 13 in the left and right cushion units 2L and 2R at the same time.
The hydraulic supply pipe 31 is provided with an electric hydraulic pump 32 and an oil tank 33 on one end side, and the other end side branches to a left and right branch pipe 34 and is connected to each hydraulic pipe 27. Each branch pipe 34 is provided with a check valve 35 that prevents the flow of hydraulic oil from the hydraulic pipe 27 side to the hydraulic pump 32 side.

  A shutoff valve 36 is provided between each check valve 35 and the hydraulic pipe 27 in each branch pipe 34 so that the hydraulic pressure from the hydraulic pipe 27 (hydraulic pressure from the hydraulic cylinder 13) can be released into the oil tank 33. Each of the hydraulic return pipes 37 is extended. Each shut-off valve 36 is, for example, an electromagnetic type, and closes the hydraulic pressure return pipe 37 during normal times (when not energized), and opens the hydraulic pressure return pipe 37 when energized.

In such a suspension device 1, the vehicle body posture (right / left inclination, that is, roll and vehicle height) can be controlled by appropriately controlling the operation of the gear pump 20, the hydraulic pump 32, and each shut-off valve 36 by the ECU.
That is, when the vehicle is turning, the outside of the vehicle body in the turning radial direction (hereinafter simply referred to as the outside of the turning) sinks, and the inside of the turning radius direction (hereinafter simply referred to as the inside of the turning) tends to rise.
At this time, the coil spring 6 of the cushion unit 2 outside the swing is compressed by the load increase, and the coil spring 6 of the cushion unit 2 inside the swing is expanded by the load decrease.

  In such a case, by operating the gear pump 20, for example, hydraulic oil is pumped from the hydraulic cylinder 13 of the cushion unit 2 inside the swing to the hydraulic cylinder 13 of the cushion unit 2 outside the swing, and the lower spring seat 12 inside the swing is lowered. The length of the left and right cushion units 2L and 2R, that is, the cushion arrangement in the vehicle body, is absorbed by absorbing the extension of the coil spring 6 and raising the lower spring seat 12 on the outside of the turn to follow the compression of the coil spring 6. The difference in the height of the parts is suppressed, and the roll of the vehicle body is suppressed.

  When adjusting the height of the vehicle body, first, the hydraulic pump 32 is operated in a state where each shut-off valve 36 is de-energized and each hydraulic return pipe 37 is closed, so that hydraulic pressure is supplied to the left and right hydraulic cylinders 13 and left and right lower The spring seat 12 is raised. Thereby, the cushion arrangement part in the vehicle body is jacked up via the coil spring 6 and the like, and the vehicle height increases. On the other hand, by opening each hydraulic pressure return pipe 37 with each shut-off valve 36 energized, the hydraulic pressure in the left and right hydraulic cylinders 13 is released and the left and right lower spring seats 12 are lowered. Thereby, the cushion arrangement | positioning site | part in a vehicle body is jacked down and vehicle height reduces.

The stabilizer 41 is formed by using a spring steel bar as a torsion bar, and is bent so as to extend along the front-rear direction from both ends of the torsion part 42 extending in the left-right direction of the vehicle body (vehicle width direction). The arm portion 43 extends. The left and right side portions of the torsion portion 42 are attached to the left and right side frames of the vehicle body via bushes 42a.
The lower ends of the left and right stabilizer links 44 are swingably connected to the distal ends of both arm portions 43 of the stabilizer 41, and the upper ends of the stabilizer links 44 are connected to the hydraulic cylinders 13 in the left and right cushion units 2L and 2R. The cylinder outer 15 is connected to the outer periphery of the cylinder outer 15 so as to be swingable.

  When the vehicle body is tilted left and right, the stabilizer 41 twists the torsion part 42 so as to displace the tip of the arm part 43 on one side upward and the tip of the arm part 43 on the other side downward. On the other hand, the torsion part 42 functions to keep the vehicle body horizontal from left to right as it tries to return to its original position. In other words, in a state where the vehicle body is kept horizontal, the stabilizer 41 basically does not function even if the vehicle body moves up and down.

  In such a suspension device 1, during normal traveling without roll control, the operation of the gear pump 20 is stopped and the cylinder outer 15 of the left and right hydraulic cylinders 13 is maintained at the intermediate position. In this state, if the vehicle body is horizontal, the left and right lower spring seats 12 have the same height, and the spring reaction force of the stabilizer 41 does not act on the left and right cushion units 2. Therefore, when the left and right wheels move up and down in the same phase when the vehicle travels, the coil spring 6 of the cushion unit 2 alone supports the vehicle body as a spring, and the vehicle body vibration is favorably absorbed with low spring rigidity.

  On the other hand, when the vehicle is turning, the outside of the vehicle body sinks and the vehicle body tends to incline so that the inside of the turning radius is lifted. In such a case, the gear pump 20 is operated and the hydraulic cylinder inside the vehicle turns When the hydraulic oil is pumped from the hydraulic cylinder 13 to the hydraulic cylinder 13 outside the turning, the lower spring seat 12 is lowered due to the hydraulic oil being discharged from the hydraulic cylinder 13 inside the turning, and the hydraulic oil 13 is pumped from the hydraulic cylinder 13 outside the turning. The lower spring seat 12 rises. As a result, the left and right inclination (roll) of the vehicle body during the turning travel is suppressed.

  Further, during the turning, the operating force of the hydraulic cylinder 13 when the lower spring seat 12 inside the turning is lowered is input to the stabilizer 41 via the stabilizer link 44 so as to push it down. The operating force of the hydraulic cylinder 13 when raising the outer lower spring seat 12 is input to push the other side of the stabilizer 41 through the stabilizer link 44. Thereby, the twist generated in the torsion part 42 of the stabilizer 41 is in the same direction as the twist generated by the roll of the vehicle body during the turning.

  That is, by connecting the stabilizer 41 to the cylinder outer 15 of the hydraulic cylinder 13 that is movable during roll control, when the lower end support position (lower spring seat 12) of the coil spring 6 is displaced by the control of the hydraulic cylinder 13, A stabilizer reaction force that takes into account the displacement of the lower spring seat 12 can be generated while suppressing the roll of the vehicle body by the hydraulic cylinder 13. As a result, the stabilizer effect can be sufficiently obtained and the spring rigidity (roll rigidity) of the suspension device 1 can be increased.

  Therefore, in the case of the suspension device 1, the load on the coil spring 6 of each cushion unit 2 is reduced as compared with the case where the stabilizer 41 is not provided, and each hydraulic cylinder 13 moves (strokes) the lower spring seat 12. The load of is also reduced. In addition, the output of the gear pump 20 that strokes the hydraulic cylinder 13 is also suppressed, so that the suspension device 1 can be reduced in size and weight.

  Here, the outer peripheral surface of the piston rod 8 is a sliding surface with a seal on the inner periphery of the upper end of the damper cylinder 7, and this sealing sliding surface is used as a sealing sliding surface of the upper end of the hydraulic cylinder 13 (vehicle body side sealing portion 15a). Is used, only the processing as the seal sliding surface is performed only in the range corresponding to the lower end portion (wheel-side seal portion 15b) of the hydraulic cylinder 13 on the outer peripheral surface of the damper cylinder 7, and the both ends of the hydraulic cylinder 13 are supported. The manufacturing man-hours of the damper 5 are reduced as compared with the case where the seal sliding surface is provided in the range.

  The upper spring seat 11 has a disk shape substantially orthogonal to the cushion axis C, and a bump stopper 46 is provided below the center of the piston spring 8 so as to project downward (lower spring seat 12 side). It is provided so as to enter the coil spring 6 in a state. Here, the distance s (see FIG. 2) between the lower end of the bump stopper 46 and the upper end of the vehicle body side seal portion 15a corresponds to the effective stroke length of the cushion unit 2 (damper 5).

  When hydraulic oil is pumped into the oil chamber 16 of the hydraulic cylinder 13 in such a state that the cushion unit 2 supports the vehicle body, the cylinder outer 15 and the lower spring seat 12 (movable lower spring seat 12A) become the damper cylinder. 7 moves to the vehicle body side and jacks up the cushion support portion of the vehicle body via the coil spring 6 (or compresses the coil spring 6 to increase the spring reaction force of the cushion unit 2, that is, the support load). On the other hand, when the hydraulic oil is discharged from the oil chamber 16 of the hydraulic cylinder 13, the cylinder outer 15 and the lower spring seat 12 move to the wheel side with respect to the damper cylinder 7, and cushion the vehicle body via the coil spring 6. The support portion is jacked down (or the extension of the coil spring 6 is allowed to reduce the spring reaction force of the cushion unit 2, that is, the support load).

  As described above, when the cylinder outer 15 moves in the cushion vertical direction, the upper spring seat 11 and the bump stopper 46 also move in the cushion vertical direction via the coil spring 6. Therefore, compared with the case where the hydraulic cylinder 13 is provided not on the damper cylinder 7 but only on the outer periphery of the piston rod 8, the influence on the effective stroke length of the damper 5 can be suppressed even during the vehicle body posture control by the operation of the hydraulic cylinder 13. Thus, the overall length of the cushion unit 2 can be suppressed. Further, since the hydraulic cylinder 13 is provided across the damper cylinder 7 and the piston rod 8, the rigidity against the lateral force of the entire damper 5 (force from a direction intersecting the axial direction, stabilizer reaction force, etc.) is enhanced.

  As described above, the suspension device 1 according to this embodiment includes the damper 5 disposed between the vehicle body and the wheel to buffer the vertical movement of the wheel with respect to the vehicle body, and provided substantially coaxially with the damper 5. A coil spring 6 that receives a relative load between a vehicle body and a wheel, and an upper spring seat 11 and a lower spring seat 12 that support upper and lower ends of the coil spring 6, the lower spring seat 12 ( The movable lower spring seat 12A) is disposed on the outer periphery of the damper cylinder 7 of the damper 5 and is movable in the axial direction with respect to the damper cylinder 7. The lower spring seat 12 is arranged on the outer periphery of the damper cylinder 7. A hydraulic cylinder 13 is formed on the side, and hydraulic oil is pumped and discharged from the hydraulic cylinder 13. In, in which the lower spring seat 12 moves in the axial direction with respect to the damper 5.

  According to this configuration, by providing the hydraulic cylinder 13 on the outer periphery of the damper cylinder 7, the stroke of the damper 5 is not sacrificed, and the length of the damper 5 and thus the length of the cushion unit 2 is suppressed to improve the degree of freedom for mounting on the vehicle body. Can do. Further, by providing the hydraulic cylinder 13 on the outer periphery of the damper cylinder 7 having a relatively large diameter in the damper 5, the rigidity of the damper cylinder 7 can be effectively utilized to reduce the size and weight of the hydraulic cylinder structure.

  In the suspension device 1, the lower spring seat 12 (movable lower spring seat 12 </ b> A) is provided across the outer periphery of the damper cylinder 7 and the outer periphery of the piston rod 8 in the damper 5, so that the stroke of the damper 5 is achieved. The rigidity with respect to the lateral force of the damper 5 can be efficiently increased without sacrificing. At this time, the outer peripheral surface of the piston rod 8, which is a seal sliding surface in the damper 5, can also be effectively used as the seal sliding surface of the hydraulic cylinder 13.

Next, a second embodiment of the present invention will be described with reference to FIG.
The suspension device 101 in this embodiment is different from the first embodiment mainly in that a cylinder outer 115 having a sliding surface with the damper cylinder 7 side is provided on the inner periphery. The same parts are denoted by the same reference numerals and the description thereof is omitted.

  The hydraulic cylinder 113 in this embodiment is provided so as to surround only the outer periphery of the damper cylinder 7 without reaching the piston rod 8. The cylinder outer 115 has a cylindrical shape that covers the outer periphery of the damper cylinder 7, and the upper end portion (end portion on the vehicle body side) has an inner periphery that slides a seal against the outer peripheral surface of the damper cylinder 7 that vertically passes through the cylinder outer 115. A seal portion 115a is provided. The inner peripheral surface of the cylinder outer 115 has a smooth cylindrical shape, and a wheel-side seal portion 7 b that slides the seal on the inner peripheral surface is provided on the outer periphery of the damper cylinder 7 in the cylinder outer 115. That is, the inner peripheral surface of the cylinder outer 115 forms a seal sliding surface below the hydraulic cylinder 113.

  A predetermined gap is formed between the inner peripheral surface of the cylinder outer 115 and the outer peripheral surface of the damper cylinder 7, and the gap portion forms an oil chamber 16 in the hydraulic cylinder 113. In this embodiment, a flange-like lower spring seat 12 is integrally provided on the outer periphery of the upper portion of the cylinder outer 115, and the main hydraulic inflow / outflow port 18 is provided immediately below the lower spring seat 12.

  As described above, in the suspension device 101 in the second embodiment, the lower spring seat 12 (movable lower spring seat 12A) has the cylinder outer 115 coaxial with the damper cylinder 7, and the cylindrical portion. By making the inner peripheral surface of the damper cylinder 7 a sliding surface with the damper cylinder 7 side, it is possible to prevent the sliding surface from being damaged by flying stones, etc., compared to the case where the outer peripheral surface of the damper cylinder 7 is a sliding surface. Cost reduction can be achieved by eliminating the need for a dust cover or the like. The configuration of this embodiment is also applicable to a hydraulic cylinder straddling the outer periphery of the piston rod 8 and the outer periphery of the damper cylinder 7 as in the first embodiment.

Next, a third embodiment of the present invention will be described with reference to FIG.
The suspension device 201 in this embodiment is mainly different from the second embodiment in that a coil 249 constituting a part of the stroke detection sensor 248 of the hydraulic cylinder 113 is provided on the outer periphery of the damper cylinder 7. Therefore, the same reference numerals are given to the same parts as those in the previous embodiment, and the description thereof is omitted.

The coil 249 is provided over a predetermined range, for example, below the wheel-side seal portion 7b on the outer periphery of the damper cylinder 7, and by detecting a change in inductance of the coil 249, the hydraulic cylinder 113 (cylinder outer 115) The stroke amount can be detected.
More specifically, since the inductance of the coil 249 affects the magnetic permeability when they are the same, a metal sleeve (cylinder outer 115) having a high magnetic permeability is arranged on the outside, and this is moved to transmit the magnetic sleeve. By changing the magnetic susceptibility, the inductance changes and the flowing current value changes. The position of the cylinder outer 115 relative to the damper cylinder 7 (that is, the stroke amount of the hydraulic cylinder 113) can be detected by reading a change in voltage applied to the coil 249 with a resistor or an ammeter arranged in series. .

  As described above, in the suspension device 201 in the third embodiment, the coil 249 coaxial with the suspension is arranged inside the cylinder outer 115, and the coil 249 detects the stroke amount of the hydraulic cylinder 113. By configuring a part of the cushion unit 2 as compared with the case where a separate sensor is externally attached to the hydraulic cylinder 113, the cushion unit 2 can be reduced in size and weight and the cost can be reduced. The configuration of this embodiment is also applicable to a hydraulic cylinder straddling the outer periphery of the piston rod 8 and the outer periphery of the damper cylinder 7 as in the first embodiment.

Next, a fourth embodiment of the present invention will be described with reference to FIG.
The suspension device 301 in this embodiment is mainly different from the second embodiment in that a hydraulic cylinder 313 unitized separately from the damper 5 is attached to the outer periphery of the damper cylinder 7. The same parts are denoted by the same reference numerals and the description thereof is omitted.

The hydraulic cylinder 313 in this embodiment is configured on a cylindrical base sleeve 351 having an inner peripheral surface aligned with the outer peripheral surface of the damper cylinder 7.
The base sleeve 351 is integrally fixed to the damper cylinder 7 by a stopper mechanism 352 that is fixed to the outer periphery of the damper cylinder 7 adjacent to both ends thereof with the damper cylinder 7 inserted through the inner periphery thereof. The stopper mechanism 352 is configured by, for example, a ring-shaped member that is fixed to the outer periphery of the damper cylinder 7 by welding or the like, or a C-ring that is fitted into an annular groove on the outer periphery of the damper cylinder 7. The outer peripheral surface of the upper half of the base sleeve 351 constitutes a sliding surface with the vehicle body side seal portion 115a of the cylinder outer 115.

A cylindrical piston sleeve 353 having an inner peripheral surface aligned with the outer peripheral surface is integrally attached to the lower half portion of the base sleeve 351. A wheel side seal portion 353 b is provided on the outer periphery of the upper end portion of the piston sleeve 353 so that the seal is in sliding contact with the inner peripheral surface of the cylinder outer 115.
A predetermined gap is formed between the inner circumferential surface of the cylinder outer 115 and the outer circumference of the base sleeve 351, and the gap portion forms the oil chamber 16 in the hydraulic cylinder 313. In this embodiment, the lower spring seat 12 having a flange shape is integrally provided on the outer periphery of the upper portion of the cylinder outer 115, and a bracket for connecting the stabilizer link 44 of the stabilizer 41 just below the lower spring seat 12. 354 is provided, and the main hydraulic inflow / outflow port 18 is provided on the outer periphery of the lower end of the piston sleeve 353.

  Such a hydraulic cylinder 313 can be handled as an integral unit different from the damper 5, and is compatible as long as it is at least between dampers having the same outer diameter of the damper cylinder 7, and in the damper axial direction. It is also possible to easily change the mounting position of. As a result, the assembly of the cushion unit 2 is facilitated, the damper for mounting the hydraulic cylinder need not be designed exclusively, and the outer peripheral surface of the damper cylinder 7 need not be processed as a seal sliding surface.

  As described above, in the suspension device 301 in the fourth embodiment, the hydraulic cylinder 313 is unitized separately from the damper 5 so that the assembly man-hour of the cushion unit 2 can be reduced and the damper for each vehicle type can be reduced. The cost of the cushion unit 2 can be reduced by suppressing the increase in the design man-hours corresponding to the above, suppressing the increase in the man-hours for manufacturing the damper, and enhancing the versatility of the hydraulic cylinder 313.

1 is a schematic configuration diagram of a vehicle suspension device according to an embodiment of the present invention. It is a principal part enlarged view of the cushion unit of the said suspension apparatus. It is a principal part enlarged view equivalent to FIG. 2 in 2nd Example of this invention. It is a principal part enlarged view equivalent to FIG. 2 in the 3rd Example of this invention. It is a principal part enlarged view equivalent to FIG. 2 in 4th Example in this invention.

Explanation of symbols

1, 101, 201, 301 Vehicle suspension device 2 Cushion unit 5 Damper 6 Coil spring 7 Damper cylinder (cylinder)
8 Piston rod (rod)
11 Upper spring seat 12 Lower spring seat 12A Movable lower spring seat 13, 113, 313 Hydraulic cylinder (fluid cylinder)
115 Cylinder outer (cylindrical part)
248 Sensor 249 Coil

Claims (3)

A damper disposed between the vehicle body and the wheel to cushion the vertical movement of the wheel relative to the vehicle body; a coil spring provided substantially coaxially with the damper to receive a relative load between the vehicle body and the wheel; and the coil In a vehicle suspension apparatus comprising an upper spring seat and a lower spring seat that support upper and lower ends of a spring,
The lower spring seat is disposed on the outer periphery of the cylinder of the damper and is movable in the axial direction with respect to the cylinder. The lower spring seat forms a fluid cylinder on the outer peripheral side of the cylinder, and the fluid When the fluid is pumped and discharged from the cylinder, the lower spring seat moves in the axial direction with respect to the damper ,
The fluid cylinder includes a cylinder outer that is in sliding contact with the piston rod on the axially upper side of the damper and that is in sliding contact with the cylinder on the axially lower side of the damper, and the cylinder outer includes the inner surface of the cylinder outer, the cylinder, and the cylinder A suspension apparatus for a vehicle , wherein an oil chamber is formed between an outer surface of a piston rod and a hydraulic inflow / outflow port through which a fluid in the oil chamber flows in / out . The vehicle suspension device according to claim 1, wherein the lower spring seat is provided across the cylinder outer periphery and the piston rod outer periphery of the damper. The vehicle suspension apparatus according to claim 1 or 2 , wherein a coil coaxial with the cylinder outer is disposed inside the cylinder outer , and the coil constitutes a sensor for detecting a stroke amount of the fluid cylinder.

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