JP2015113090A - Suspension device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a suspension device capable of utilizing differential pressure generated in a system when a vehicle turns, for the steering of left and right wheels.SOLUTION: A suspension device 4 according to an embodiment includes, for example, a left cylinder unit, a right cylinder unit, a left accumulator, a right accumulator and a steering cylinder unit. The steering cylinder unit has a steering piston of which one side in a left to right direction is connected to a left wheel and the other side is connected to a right wheel, of which movement to one side steers left and right wheels toward one of a clockwise direction and a counterclockwise direction in a view from above, and of which movement to the other side steers the left and right wheels toward the other of the clockwise direction and the counterclockwise direction.

Description

  Embodiments described herein relate generally to a suspension device.

  Conventionally, a left cylinder unit interposed between the vehicle body and the left wheel, and a right cylinder unit interposed between the vehicle body and the right wheel, the upper chamber of the left cylinder unit and the lower chamber of the right cylinder unit And a suspension device in which a lower chamber of the left cylinder unit and an upper chamber of the right cylinder unit are communicated with each other.

Japanese Patent No. 4890191

  In this type of suspension device, it may be advantageous if the differential pressure generated in the system when the vehicle turns can be used for steering the left and right wheels.

  The suspension device of the embodiment includes, for example, a left cylinder unit, a right cylinder unit, a left accumulator, a right accumulator, and a steered cylinder unit. The left cylinder unit has a left piston connected to one of the left wheel and the vehicle body, and a left cylinder connected to the other of the left wheel and the vehicle body that movably accommodates the left piston, Left first chamber between the piston and the left cylinder shrinks as the ground contact point of the left wheel and the vehicle body approach in the vertical direction, and extends as the ground contact point of the left wheel and the vehicle body move away in the vertical direction And a left second chamber that extends as the ground contact point of the left wheel and the vehicle body approach in the vertical direction and contracts as the ground contact point of the left wheel and the vehicle body move away in the vertical direction. The right cylinder unit includes a right piston connected to one of the right wheel and the vehicle body, and a right cylinder connected to the other of the right wheel and the vehicle body that movably accommodates the right piston, Between the piston and the right cylinder, it communicates with the second chamber on the left side and shrinks as the grounding point of the right wheel and the vehicle body approach the vertical direction, while the grounding point of the right wheel and the vehicle body move away in the vertical direction. The right side first chamber and the right side first chamber communicate with each other and extend as the ground contact point of the right wheel and the vehicle body approach the vertical direction, while the ground contact point of the right wheel and the vehicle body move away from each other in the vertical direction. A second right chamber that shrinks accordingly is formed. The left accumulator is in communication with the left first chamber. The right accumulator is in communication with the right first chamber. The steered cylinder unit is connected to the left wheel on one side in the left-right direction and connected to the right wheel on the other side. By moving to the one side, the left wheel and the right wheel are clockwise and counterclockwise as viewed from above. Steering piston that steers the left and right wheels to the other of the clockwise and counterclockwise directions by turning to one of the turning directions and moving to the other, and the turning piston can be moved And a steering cylinder connected to the vehicle body, and communicated with one of the left first chamber and the right first chamber between the steering piston and the steering cylinder. A third piston that contracts as it moves to the side and extends as the steering piston moves to the other side, and a steering piston that communicates with the other of the left first chamber and the right first chamber On the other hand a fourth chamber which steering piston with extending according to move to the side shrinks in response to the movement to the other side, is formed. Therefore, according to the suspension device of the embodiment, as an example, since the steering cylinder unit is provided, when a differential pressure is generated in the system when the vehicle turns, the left wheel and the right wheel are used by using the differential pressure. Can be steered.

  In the suspension device, for example, one of the left first chamber and the right first chamber communicates with the third chamber, and the other of the left first chamber and the right first chamber and the first chamber. A state in which the four chambers are communicated, one of the left first chamber and the right first chamber and the third chamber are shut off, and the other of the left first chamber and the right first chamber is A first switching valve that can switch between a state in which the four chambers are shut off is further provided. Therefore, according to the suspension device of the embodiment, as an example, it is easy to suppress the operation of the turning piston when the turning of the vehicle is not necessary.

  In the suspension device, for example, one of the left first chamber and the right first chamber communicates with the third chamber, and the other of the left first chamber and the right first chamber and the first chamber. The four chambers communicated with each other, one of the left first chamber and the right first chamber communicated with the fourth chamber, and the other of the left first chamber and the right first chamber and the first chamber. A second switching valve capable of switching between a state in which the three chambers are communicated is further provided. Therefore, according to the suspension device of the embodiment, for example, the turning direction can be switched.

  In the suspension device, for example, an elastic member that is provided in at least one of the third chamber and the fourth chamber and biases the steering piston in a direction in which the left wheel and the right wheel are not steered is further provided. Prepared. Therefore, according to the suspension device of the embodiment, as an example, after turning by the turning cylinder, the turning piston is likely to return to the neutral position more quickly.

FIG. 1 is a schematic front view showing an example of a suspension device provided on the rear wheel of the vehicle according to the first embodiment. FIG. 2 is a schematic front view showing an example of a suspension device provided on the rear wheel of the vehicle according to the first embodiment, and is a view showing a state during a left turn. FIG. 3 is a schematic plan view of the example of the vehicle in FIG. 2 viewed from above the vehicle. FIG. 4 is a schematic front view showing an example of a suspension device provided on the rear wheel of the vehicle according to the second embodiment. FIG. 5 is a hydraulic circuit diagram showing an example of the first switching valve of the suspension device of the second embodiment. FIG. 6 is a hydraulic circuit diagram illustrating an example of a second switching valve of the suspension device of the third embodiment. FIG. 7 is a schematic plan view of an example of a vehicle including the suspension device according to the third embodiment as viewed from above the vehicle, and shows a state in which the front wheels and the rear wheels are steered in opposite phases. It is.

  Hereinafter, embodiments will be described with reference to the drawings. It should be noted that the following exemplary embodiments include similar components. Therefore, below, the same code | symbol is attached | subjected to the same component, and the overlapping description is abbreviate | omitted. In the following drawings, directions are defined for convenience. The X direction is the front of the vehicle 1 (traveling direction), the Y direction is the left when facing the front of the vehicle 1 (right in front view, left in rear view), and the Z direction is above the vehicle 1. It is.

  Further, the configuration of the embodiment shown below, and the operation and result (effect) brought about by the configuration are merely examples. The present invention can be realized by configurations other than those disclosed in the following embodiments, and various effects (including derivative effects) obtained by the basic configuration can be obtained.

<First Embodiment>
In the present embodiment, as shown in FIG. 1, the vehicle 1 includes a suspension device 4 interposed between the vehicle body 2 and the wheels 3. Specifically, as shown in FIG. 3, in this embodiment, the suspension device 4 is positioned between the left rear wheel 3 </ b> A (left wheel) and the right rear wheel 3 </ b> B (right wheel) and the vehicle body 2. Yes. Each wheel 3 is connected to the vehicle body 2 by a support mechanism 5 (support portion) so as to be movable relative to the vehicle body 2 (movable up and down). The support mechanism 5 includes a plurality of arm members 6 (link members) connected to the vehicle body 2 and the wheels 3. The arm member 6 is an example of a connecting member connected to the wheel 3 (a support member that supports the wheel 3).

  As shown in FIG. 1, the suspension device 4 includes a left cylinder unit 11A, a right cylinder unit 11B, a left accumulator 12A, a right accumulator 12B, a passage structure 14, a left suspension spring 15A, and a right suspension spring. 15B and the turning cylinder unit 21 are provided. 1 and 2 are schematic views of the left rear wheel 3A and the right rear wheel 3B as viewed from the front (front) side of the vehicle 1. FIG.

  The left cylinder unit 11A is interposed between the left rear wheel 3A and the vehicle body 2, and includes a left cylinder 16A, a left piston 17A, and a left piston rod 18A. The left cylinder 16A is provided in a state extending substantially along the vertical direction (Z direction) of the vehicle 1, and is configured in a cylindrical shape in which one end (upper end) and the other end (lower end) are closed. ing. An oil chamber R filled with working oil (working fluid, fluid, liquid, medium) is provided inside the left cylinder 16A. The left piston 17A is positioned inside the left cylinder 16A and partitions the oil chamber R into a left first chamber RL1 and a left second chamber RL2. In the present embodiment, the left first chamber RL1 is the upper oil chamber R of the left piston 17A, and the left second chamber RL2 is the lower oil chamber R of the left piston 17A. The left piston rod 18A has one end (upper end) connected (connected) to the left piston 17A and the other end (lower end) passing through the other end (lower end) of the left cylinder 16A. It protrudes from 16A. In the present embodiment, one end (upper end) of the left cylinder 16A is connected to the connecting portion 2a (connecting portion) of the vehicle body 2, and the other end (lower end) of the left piston rod 18A is connected to the left rear wheel. The arm member 6 is connected to 3A. The left cylinder unit 11A expands and contracts when the left piston 17A moves relative to the left cylinder 16A together with the left piston rod 18A (reciprocates vertically). Specifically, in the present embodiment, when the ground contact point P1 of the left rear wheel 3A and the vehicle body 2 approach (approach) in the vertical direction (Z direction), the left piston 17A moves upward in the left cylinder 16A. To do. As a result, the left first chamber RL1 contracts, the volume of the left first chamber RL1 decreases, the left second chamber RL2 extends, and the volume of the left second chamber RL2 increases. Conversely, when the ground contact point P1 of the left rear wheel 3A and the vehicle body 2 are moved away (separated) in the vertical direction (Z direction), the left piston 17A moves downward in the left cylinder 16A. As a result, the left first chamber RL1 extends to increase the volume of the left first chamber RL1, and the left second chamber RL2 contracts to decrease the volume of the left second chamber RL2.

  The right cylinder unit 11B is interposed between the right rear wheel 3B and the vehicle body 2, and includes a right cylinder 16B, a right piston 17B, and a right piston rod 18B. The right cylinder 16B is provided in a state extending substantially along the vertical direction (Z direction) of the vehicle 1, and is configured in a cylindrical shape in which one end (upper end) and the other end (lower end) are closed. ing. An oil chamber R filled with working oil (working fluid, fluid, liquid, medium) is also provided in the right cylinder 16B. The right piston 17B is positioned inside the right cylinder 16B and partitions the oil chamber R into a right first chamber RR1 and a right second chamber RR2. In the present embodiment, the right first chamber RR1 is the upper oil chamber R of the right piston 17B, and the right second chamber RR2 is the lower oil chamber R of the right piston 17B. The right piston rod 18B has one end (upper end) connected (connected) to the right piston 17B and the other end (lower end) passing through the other end (lower end) of the right cylinder 16B. It protrudes from 16B. In this embodiment, one end (upper end) of the right cylinder 16B is connected to the connecting portion 2a (connecting portion) of the vehicle body 2, and the other end (lower end) of the right piston rod 18B is connected to the right rear wheel. It is connected to the arm member 6 connected to 3B. The right cylinder unit 11B expands and contracts when the right piston 17B moves relative to the right cylinder 16B together with the right piston rod 18B (reciprocates in the vertical direction). Specifically, in the present embodiment, when the ground contact point P2 of the right rear wheel 3B and the vehicle body 2 approach (approach) in the vertical direction (Z direction), the right piston 17B moves upward in the right cylinder 16B. To do. As a result, the right first chamber RR1 contracts, the volume of the right first chamber RR1 decreases, the right second chamber RR2 extends, and the volume of the right second chamber RR2 increases. Conversely, when the ground contact point P2 of the right rear wheel 3B and the vehicle body 2 move away (separate) in the vertical direction (Z direction), the right piston 17B moves downward in the right cylinder 16B. Accordingly, the right first chamber RR1 extends to increase the volume of the right first chamber RR1, and the right second chamber RR2 contracts to decrease the volume of the right second chamber RR2.

  The passage structure portion 14 includes a first passage 14a that communicates the left first chamber RL1 and the right second chamber RR2, and a second passage 14b that communicates the left second chamber RL2 and the right first chamber RR1. It has been. The passage structure portion 14 is a structure that forms the first passage 14a, the second passage 14b, and the like, and is, for example, a plurality of pipes 41 to 44. The passage structure 14 can be configured as a block, a hose, a tube, or the like. The passage is formed as a hole provided in the passage structure portion 14. In the present embodiment, the pipe 41 provided with the first passage 14a and the pipe 42 provided with the second passage 14b are piped so as to form a substantially X shape when viewed from the front (back view). These pipes 41 and 42 are fixed to the left cylinder 16A and the right cylinder 16B, respectively. The hydraulic oil is put into the first passage 14a and the second passage 14b, and the hydraulic oil flows through the first passage 14a and the second passage 14b.

  The left accumulator 12A communicates with the left first chamber RL1 via the first passage 14a. The right accumulator 12B communicates with the right first chamber RR1 through the second passage 14b. The left accumulator 12A receives hydraulic fluid that has flowed out of the left first chamber RL1 and the right second chamber RR2 (first passage 14a) or operates to the left first chamber RL1 and the right second chamber RR2 (first passage 14a). Or supply oil. On the other hand, the right accumulator 12B receives hydraulic oil flowing out from the right first chamber RR1 and the left second chamber RL2 (second passage 14b), or receives the right first chamber RR1 and the left second chamber RL2 (second passage 14b). Or supply hydraulic oil to Inside the left accumulator 12A and the right accumulator 12B, an air chamber R5 filled with gas and an oil chamber R6 in which hydraulic oil can flow in and out are partitioned so as to change the volume. The left accumulator 12A and the right accumulator 12B are formed as springs (gas springs) by changing the volume (gas volume) of the air chamber R5 in accordance with the change in the volume of the oil chamber R6 (volume of hydraulic oil). Works. Specifically, when the hydraulic oil flows into the oil chamber R6, the gas in the air chamber R5 is compressed, and the repulsive force (spring force, biasing force) of the compressed gas acts on the hydraulic oil, and the roll of the vehicle 1 Rigidity (stabilizer function) can be imparted. The left accumulator 12A and the right accumulator 12B are fixed to the vehicle body 2.

  The left suspension spring 15A is provided between the arm member 6 connected to the left rear wheel 3A and the vehicle body 2. The right suspension spring 15B is provided between the arm member 6 connected to the right rear wheel 3B and the vehicle body 2. The left suspension spring 15 </ b> A and the right suspension spring 15 </ b> B are interposed between the vehicle body 2 and the arm member 6, so that the stretchable portion elastically supports the weight of the vehicle body 1 and can absorb the impact. The left suspension spring 15A and the right suspension spring 15B are, for example, coil springs.

  With the configuration described above, the suspension device 4 controls the posture of the vehicle body 2 by suppressing the movement of the corresponding piston in each cylinder by the pressure change of each part due to the relative movement between the vehicle body 2 and the wheel 3. be able to.

  When the vehicle 1 turns, the cylinder unit provided on the wheel 3 serving as the outer ring contracts, and the cylinder unit provided on the wheel 3 serving as the inner ring extends. As an example, as shown in FIG. 3, when the vehicle 1 turns in the A direction (in this embodiment, the left direction as an example, the counterclockwise direction in plan view from above the vehicle), the left cylinder unit 11 </ b> A extends. The right cylinder unit 11B contracts. In this case, as shown in FIG. 2, in the left cylinder unit 11A, the volume of the left first chamber RL1 increases, the volume of the left second chamber RL2 decreases, and in the right cylinder unit 11B, the right first chamber RR1. The volume of the right side second chamber RR2 increases. That is, the volume decreases in both the left second chamber RL2 and the right first chamber RR1 communicated by the second passage 14b. Therefore, the hydraulic fluid that has flowed out of the left second chamber RL2 and the right first chamber RR1 flows into the second passage 14b, and a part of the hydraulic fluid flows to the right accumulator 12B. On the other hand, since the volume increases in both the left first chamber RL1 and the right second chamber RR2 communicated by the first passage 14a, the left first chamber RL1 and the right first chamber RL1 are connected to the right first chamber RL1 from the left accumulator 12A via the first passage 14a. The hydraulic oil is supplied to the second chamber RR2. When turning in the reverse direction, each component operates in the reverse direction, and a flow of hydraulic oil is formed. According to this embodiment, when the vehicle 1 turns, the suspension device 4 can control the roll motion of the vehicle 1 (the roll posture of the vehicle body 2) by the gas spring action of the left accumulator 12A or the right accumulator 12B. .

  Further, when both the left cylinder unit 11A and the right cylinder unit 11B contract in phase, the volumes of the left first chamber RL1 and the right first chamber RR1 are reduced, and the volumes of the left second chamber RL2 and the right second chamber RR2 are reduced. Increase. In this case, a flow of hydraulic oil is formed from the left first chamber RL1 through the first passage 14a to the right second chamber RR2. On the other hand, a flow of hydraulic oil is formed from the right first chamber RR1 through the second passage 14b to the left second chamber RL2. At this time, the volume that increases in the left second chamber RL2 and the right second chamber RR2 is less than the volume that decreases in the left first chamber RL1 and the right first chamber RR1 with respect to the piston rod (the left piston rod 18A and the right piston rod). 18B) is smaller by the volume of the left second chamber RL2 and the right second chamber RR2, the hydraulic oil flowing out from the left first chamber RL1 and the right first chamber RR1 correspondingly flows to the left second chamber RL2 and the right second chamber RL2. It becomes surplus without being able to flow into the second chamber RR2. The excess hydraulic oil flows from the left first chamber RL1 to the left accumulator 12A via the first passage 14a, and from the right first chamber RR1 to the right accumulator 12B via the second passage 14b.

  Next, when the displacements of the left cylinder unit 11A and the right cylinder unit 11B extend in phase, the volumes of the left first chamber RL1 and right first chamber RR1 increase, and the volumes of the left second chamber RL2 and right second chamber RR2 increase. Decrease. In this case, the hydraulic oil flowing out from the left second chamber RL2 flows into the right first chamber RR1 through the second passage 14b. On the other hand, the hydraulic oil that has flowed out of the right second chamber RR2 flows into the left first chamber RL1 through the first passage 14a. At this time, the volume that decreases in the left second chamber RL2 and the right second chamber RR2 is less than the volume that increases in the left first chamber RL1 and the right first chamber RR1 with respect to the piston rod (the left piston rod 18A and the right piston rod). 18B) is smaller by the volume of the left second chamber RL2 and the right second chamber RR2 and therefore the hydraulic fluid flowing in from the left second chamber RL2 and the right second chamber RR2 is equivalent to the left first chamber RL1. In addition, the hydraulic oil flowing into the right first chamber RR1 is insufficient. The insufficient amount of hydraulic oil is supplied from the left accumulator 12A to the left first chamber RL1 via the first passage 14a, and supplied from the right accumulator 12B to the right first chamber RR1 via the second passage 14b. Is done.

  In the present embodiment, when the left cylinder unit 11A and the right cylinder unit 11B extend and contract in phase, the suspension device 4 has almost no gas spring acting on the left accumulator 12A and the right accumulator 12B. As described above, in this embodiment, when the left cylinder unit 11A and the right cylinder unit 11B expand and contract in opposite phases, the roll motion of the vehicle 1 can be controlled by the gas spring action, and in the same phase. The gas spring hardly acts on the. With such a configuration, it functions as a stabilizer.

  In the present embodiment, the steered cylinder unit 21 is interposed between the left rear wheel 3A and the right rear wheel 3B, and includes a steered cylinder 26, a steered piston 27, and a steered piston rod 28. Have. The steered cylinder 26 is positioned along the vehicle width direction (left and right direction, Y direction), and has one end (the end on the left rear wheel 3A side) and the other end (the end on the right rear wheel 3B side). It is configured as a closed cylinder. An oil chamber R filled with working oil (working fluid, fluid, liquid, medium) is provided inside the steered cylinder 26. The steered piston 27 is located inside the steered cylinder 26 and partitions the oil chamber R into a third chamber R3 and a fourth chamber R4. In the present embodiment, the third chamber R3 is an oil chamber R on the left side of the steering piston 27, and the fourth chamber R4 is an oil chamber R on the right side of the steering piston 27. The steered piston rod 28 has a first rod portion 28A and a second rod portion 28B. The first rod portion 28A has the other end portion (end portion on the right rear wheel 3B side) connected (coupled) to the steering piston 27 and one end portion (end portion on the left rear wheel 3A side) steered. One end of the cylinder 26 (the end on the left rear wheel 3 </ b> A side) passes through and protrudes from the steered cylinder 26. The second rod portion 28B has one end portion (an end portion on the left rear wheel 3A side) connected (coupled) to the steering piston 27 and the other end portion (an end portion on the right rear wheel 3B side) steered. The other end of the cylinder 26 (the end on the right rear wheel 3B side) passes through and protrudes from the steered cylinder 26. The first rod portion 28A is connected to an arm member 25A (link member) that is swingably connected to the left rear wheel 3A, and the second rod portion 28B is swingably connected to the right rear wheel 3B. The arm member 25B (link member) is connected. On the other hand, the steering cylinder 26 is fixed to the vehicle body 2.

  In the present embodiment, the third chamber R3 communicates with the left first chamber RL1 via the first passage 14a and the third passage 14c, and the fourth chamber R4 communicates with the second passage 14b and the fourth passage 14d. Via the right first chamber RR1. The third passage 14c and the fourth passage 14d can be constituted by pipes 43 and 44. In the present embodiment, the pipe 43 provided with the third passage 14c connects the pipe 41 and the steering cylinder 26, and the pipe 44 provided with the fourth passage 14d connects the pipe 42 and the steering cylinder 26. Connected. The pipe 43 and the pipe 44 are an example of the passage structure unit 14. The hydraulic oil is put in the third passage 14c and the fourth passage 14d, and the hydraulic oil flows in the third passage 14c and the fourth passage 14d.

  In the steered cylinder unit 21, when a differential pressure is generated between the first passage 14 a and the second passage 14 b due to a change in the posture of the vehicle body 2, the third chamber R 3 and the fourth chamber 4 according to the differential pressure. The hydraulic oil is supplied to one of the chambers R4, and the steered piston 27 moves in the steered cylinder 26 together with the steered piston rod 28. Specifically, in this embodiment, when the hydraulic pressure of the second passage 14b is lower than the hydraulic pressure of the first passage 14a, the flow of hydraulic oil from the first passage 14a through the third passage 14c to the third chamber R3 is performed. As a result, the third chamber R3 extends to increase the volume of the third chamber R3, the fourth chamber R4 contracts, and the volume of the fourth chamber R4 decreases. In this case, the steered piston 27 moves in a direction approaching the other end of the steered cylinder 26 (the end on the right rear wheel 3B side). On the other hand, when the hydraulic pressure of the second passage 14b is higher than the hydraulic pressure of the first passage 14a, the flow of hydraulic oil from the second passage 14b through the fourth passage 14d to the fourth chamber R4 is formed, as shown in FIG. As described above, the third chamber R3 is contracted to reduce the volume of the third chamber R3, the fourth chamber R4 is extended, and the volume of the fourth chamber R4 is increased. In this case, the steered piston 27 moves in a direction (direction B) approaching one end of the steered cylinder 26 (the end on the left rear wheel 3A side).

  In the present embodiment, when the steered piston 27 moves in a direction approaching the right rear wheel 3B, the arm member 25B pushes the front part of the right rear wheel 3B and the arm member 25A moves to the front part of the left rear wheel 3A. It is comprised so that the force of the steering piston rod 28 may act in the direction which pulls. When the steered piston 27 moves in a direction (direction B) approaching the left rear wheel 3A (see FIG. 3), the arm member 25A pushes the front portion of the left rear wheel 3A and the arm member 25B moves to the right rear wheel. It is comprised so that the force of the steering piston rod 28 may act in the direction which pulls the front part of 3B. Therefore, when the steering piston 27 moves in a direction approaching the right rear wheel 3B, the left rear wheel 3A and the right rear wheel 3B are in the right direction when viewed from the front of the vehicle, and clockwise when viewed from above the vehicle 1. To steer. On the other hand, when the steering piston 27 relatively moves in the direction (B direction) approaching the left rear wheel 3A (see FIG. 3), the left rear wheel 3A and the right rear wheel 3B are leftward when viewed from the front of the vehicle. 1 Turns in the counterclockwise direction when looking from above. Thus, in this embodiment, since the steered piston 27 that can move in the vehicle width direction (left-right direction) is provided, when a differential pressure occurs in the suspension device 4, the differential pressure is used to When the rear wheel 3A and the right rear wheel 3B are steered, or when other steering (steering) systems are provided, the left rear wheel 3A and the right rear wheel 3B can be steered.

  In the suspension device 4, as described above, the left cylinder unit 11A and the right cylinder unit 11B are displaced (expanded / contracted) in the same phase, and the left cylinder unit 11A and the right cylinder unit 11B displaced (expanded / contracted) in the opposite phase. ). When the left cylinder unit 11A and the right cylinder unit 11B are displaced in opposite phases, the steered piston 27 moves in the steered cylinder 26 as described above, and the left rear wheel 3A and The right rear wheel 3B is steered. In the present embodiment, as shown in FIG. 3, the left rear wheel 3A and the right rear wheel 3B are steered (steered) in the same direction (in phase) as the left front wheel 3C and the right front wheel 3D. Has been. Therefore, according to the present embodiment, the behavior of the vehicle 1 is more easily stabilized when steering is performed during traveling at a relatively high speed. On the other hand, when the left cylinder unit 11A and the right cylinder unit 11B are displaced in the same phase, no differential pressure is generated between the first passage 14a and the second passage 14b, so the steered piston 27 moves within the steered cylinder 26. Without turning the left rear wheel 3A and the right rear wheel 3B by the steering piston 27.

  As described above, in the present embodiment, when a differential pressure is generated between the first passage 14a and the second passage 14b, the turning piston 27 is in the vehicle width direction (left-right direction) with respect to the turning cylinder 26. And a steered cylinder unit 21 that moves relative to each other. Therefore, according to the present embodiment, as an example, the left rear wheel 3A and the right rear wheel 3B can be steered using the differential pressure in the suspension device 4 when the vehicle 1 is turning.

  In the present embodiment, as an example, the left rear wheel 3A and the right rear wheel 3B are steered in the same phase (in the same direction) with respect to the left front wheel 3C and the right front wheel 3D by the passage structure section 14. ing. Therefore, according to the present embodiment, as an example, the behavior of the vehicle 1 can be more easily stabilized when the vehicle 1 turns at a higher speed. That is, the side slip of the vehicle 1 is easily suppressed.

  In the present embodiment, the arm members 25A and 25B are connected to the left rear wheel 3A and the right rear wheel 3B at a position deviated to the front side in the front-rear direction (X direction) with respect to the axle Ax (or the turning center). However, the arm members 25A and 25B may be coupled to the left rear wheel 3A and the right rear wheel 3B at a position disengaged rearward in the front-rear direction (X direction) with respect to the axle Ax.

  In the present embodiment, the left cylinder 16A and the right cylinder 16B are connected to the vehicle body 2, and the left piston rod 18A and the right piston rod 18B are connected to the wheel 3. However, the left cylinder 16A and the right cylinder 16B are connected to the wheel 3. The left piston rod 18A and the right piston rod 18B may be connected to the vehicle body 2.

Second Embodiment
The suspension device 4A according to the embodiment shown in FIGS. 4 and 5 has the same configuration as the suspension device 4 of the above embodiment. Therefore, also according to this embodiment, the same result (effect) based on the same configuration as the above embodiment can be obtained.

  However, in this embodiment, as shown in FIG. 4, elastic members 40 are provided in the third chamber R3 and the fourth chamber R4, respectively. The elastic member 40 is, for example, a coil spring. Each of the pair of elastic members 40 urges the steering piston 27 in a direction in which the steering angles of the left rear wheel 3A and the right rear wheel 3B are reduced. That is, the elastic member 40 holds the steering piston 27 in a neutral position (an intermediate position in the vehicle width direction of the steering cylinder 26). Therefore, according to this embodiment, as an example, when the vehicle 1 returns from the turning state to the straight traveling state, the steered piston 27 can be returned to the neutral position more quickly. Therefore, as an example, when the turning of the vehicle 1 is not necessary, it is easy to suppress the turning piston 27 from operating.

  In the present embodiment, a passage switching unit 30 (first switching valve) is provided. The passage switching unit 30 communicates with a third passage 14c and a fourth passage 14d. Further, in the present embodiment, the passage structure portion 14 communicates the pipe 45 provided with the fifth passage 14e for communicating the third chamber R3 and the passage switching unit 30 with the fourth chamber R4 and the passage switching unit 30. And a pipe 46 provided with a sixth passage 14f. As shown in FIG. 5, the passage switching unit 30 includes a first valve portion 31A and a second valve portion 31B. In the present embodiment, the first valve portion 31A is interposed between the third passage 14c and the fifth passage 14e, and the second valve portion 31B is interposed between the fourth passage 14d and the sixth passage 14f. ing. The first valve portion 31 </ b> A and the second valve portion 31 </ b> B respectively open the valve body 35, the elastic member 33 that urges the valve body 35 to the closed position, and the valve body 35 against the urging force of the elastic member 33. And a drive unit 32 that is moved to a position. The elastic member 33 is, for example, a coil spring, and the drive unit 32 is, for example, a solenoid. For example, the passage switching unit 30 closes the valve bodies 35 of the first valve portion 31A and the second valve portion 31B when the vehicle 1 goes straight, and operates the drive portion 32 to turn the first valve portion 31A when the vehicle 1 turns. And it can comprise so that the valve body 35 of the 2nd valve part 31B may be opened. As described above, the passage switching unit 30 is configured to block the left first chamber RL1 and the third chamber R3 and block the right first chamber RR1 and the fourth chamber R4, and the left first chamber RL1 and the third chamber R4. It is possible to switch between the state in which the chamber R3 is communicated and the right side first chamber RR1 and the fourth chamber R4 are in communication. Therefore, as an example, when the turning of the vehicle 1 is not necessary, for example, the turning piston 27 is more easily suppressed from operating.

  In the present embodiment, the steering piston 27 is held at the neutral position by the elastic member 40 provided in the third chamber R3 and the elastic member 40 provided in the fourth chamber R4. The configuration may be such that the steering piston 27 is held at the neutral position by the elastic member 40 provided in one of the chamber R3 and the fourth chamber R4.

  In the present embodiment, the first valve portion 31A connects the third passage 14c and the fifth passage 14e, and the second valve portion 31B connects the fourth passage 14d and the sixth passage 14f. The valve portion 31A may connect the third passage 14c and the sixth passage 14f, and the second valve portion 31B may connect the fourth passage 14d and the fifth passage 14e.

<Third Embodiment>
The suspension device according to the embodiment shown in FIG. 6 has the same configuration as the suspension device 4A of the second embodiment. Therefore, according to this embodiment, the same result (effect) based on the same configuration as that of the second embodiment can be obtained.

  However, in this embodiment, as shown in FIG. 6, a passage switching unit 30A (second switching valve) is provided instead of the passage switching unit 30 (first switching valve, see FIGS. 4 and 5). . In the passage switching unit 30A, each of the fifth passage 14e and the sixth passage 14f is bifurcated, one of which is connected to the first valve portion 31A and the other is connected to the second valve portion 31B. The first valve portion 31 </ b> A and the second valve portion 31 </ b> B respectively resist the valve body 36, a pair of elastic members 33 that urge the valve body 36 to the closed position, and the urging force of the elastic member 33. And a pair of drive units 32 that are moved to the first open position (first connection position) or the second open position (second connection position). The first valve portion 31A communicates the third passage 14c and the fifth passage 14e in the first open position, communicates the third passage 14c and the sixth passage 14f in the second open position, and in the closed position. The third passage 14c, the fifth passage 14e and the sixth passage 14f are blocked. On the other hand, the second valve portion 31B communicates the fourth passage 14d and the sixth passage 14f in the first open position, and communicates the fourth passage 14d and the fifth passage 14e in the second open position. In the position, the fourth passage 14d, the fifth passage 14e, and the sixth passage 14f are blocked. For example, the passage switching unit 30A moves the valve bodies 36 of the first valve portion 31A and the second valve portion 31B to the first open position when the vehicle 1 turns at high speed, and the vehicle 1 The valve bodies 36 of the first valve portion 31A and the second valve portion 31B can be configured to be moved to the second open position when, for example, turning. As described above, the passage switching unit 30A communicates the left first chamber RL1 and the third chamber R3 and the right first chamber RR1 and the fourth chamber R4, and the left first chamber RL1 and the fourth chamber R4. It is possible to switch between the state in which the chamber R4 is communicated and the right side first chamber RR1 and the third chamber R3 are in communication. Therefore, according to the present embodiment, as an example, the maneuverability of the vehicle 1 is easily improved. That is, when the vehicle 1 turns at high speed, the left rear wheel 3A and the right rear wheel 3B are steered (steered) in the same phase (in the same direction) as the left front wheel 3C and the right front wheel 3D (see FIG. 3). Can do. Therefore, as an example, the behavior of the vehicle 1 is easily stabilized. Further, when the vehicle 1 turns at low speed, the left rear wheel 3A and the right rear wheel 3B are reversed in phase with the left front wheel 3C and right front wheel 3D (in the reverse direction, see FIG. 7, in the present embodiment, the front wheels are used as an example. It can be steered (steered) in the clockwise direction and the rear wheels in the counterclockwise direction. Therefore, as an example, the minimum turning radius of the vehicle 1 is likely to be small, and a small turn is likely to occur. In the passage switching unit 30A, the third passage 14c, the fifth passage 14e, and the sixth passage 14f are shut off, and the fourth passage 14d, the fifth passage 14e, and the sixth passage 14f are turned off. it can. Therefore, according to the present embodiment, as an example, when the vehicle 1 goes straight, the left rear wheel 3A and the right rear wheel 3B are easily suppressed from being steered. Thus, the passage switching unit 30A (second switching valve) also functions as the passage switching unit 30 (first switching valve).

  In the present embodiment, the drive unit 32 is configured by a solenoid that allows the valve body 36 to take three positions. However, the drive unit 32 may be configured by a linear solenoid. In this case, the opening speed of the valve body 36 is controlled by the linear solenoid, whereby the turning speed, turning angle, etc. of the left rear wheel 3A and the right rear wheel 3B can be controlled.

  As mentioned above, although embodiment of this invention was illustrated, the said embodiment is an example to the last, Comprising: It is not intending limiting the range of invention. These embodiments can be implemented in various other forms, and various omissions, replacements, combinations, and changes can be made without departing from the scope of the invention. These embodiments are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof. In addition, the specifications of each component (structure, type, direction, shape, size, length, width, thickness, height, number, arrangement, position, material, etc.) should be changed as appropriate. Can do.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Vehicle body, 3 ... Wheel, 3A ... Left rear wheel (left wheel), 3B ... Right rear wheel (right wheel) 4, 4A ... Suspension device, 11A ... Left cylinder unit, 11B ... Right cylinder unit , 12A ... Left accumulator, 12B ... Right accumulator, 16A ... Left cylinder, 16B ... Right cylinder, 17A ... Left piston, 17B ... Right piston, 21 ... Steering cylinder unit, 26 ... Steering cylinder, 27 ... Steering piston, 30 ... passage switching unit (first switching valve), 30A ... passage switching unit (second switching valve), 40 ... elastic member, RL1 ... left first chamber, RL2 ... left second chamber, RR1 ... right first chamber, RR2 ... right second chamber, R3 ... third chamber, R4 ... fourth chamber, P1 ... ground point (for the left rear wheel), P2 ... ground point (for the right rear wheel).

Claims (4)

A left piston connected to one of the left wheel and the vehicle body, and a left cylinder connected to the other of the left wheel and the vehicle body, movably accommodating the left piston, and the left piston and the The left first chamber extends between the left wheel contact point and the vehicle body in the vertical direction and contracts as the left wheel contact point and the vehicle body move in the vertical direction and extends as the left wheel contact point and the vehicle body move in the vertical direction. And a second left chamber that extends as the ground contact point of the left wheel and the vehicle body approach in the vertical direction and contracts as the ground contact point of the left wheel and the vehicle body move away from each other in the vertical direction. Left cylinder unit,
A right piston connected to one of the right wheel and the vehicle body, and a right cylinder connected to the other of the right wheel and the vehicle body, which movably accommodates the right piston, and the right piston and the Between the right side cylinder and the left side second chamber, the ground point of the right wheel and the vehicle body shrink in response to approaching in the vertical direction, and the ground point of the right wheel and the vehicle body move away in the vertical direction. A right side first chamber that extends in response to the left side first chamber, and a right side wheel ground point and the vehicle body that are communicated with the left side first chamber and extend in response to the right wheel ground point and the vehicle body approaching in the vertical direction. A right side second chamber that shrinks as it moves away, and a right side cylinder unit that is formed,
A left accumulator in communication with the left first chamber;
A right accumulator in communication with the right first chamber;
One side in the left-right direction is connected to the left wheel and the other side is connected to the right wheel, and the left wheel and the right wheel are moved in the clockwise direction and the counterclockwise direction as viewed from above by moving to the one side. A steering piston that steers the left and right wheels to the other of the clockwise direction and the counterclockwise direction by moving to one side and moving to the other side, and the steering piston can be moved And a steering cylinder connected to the vehicle body, and communicated with one of the left first chamber and the right first chamber between the steering piston and the steering cylinder. A third chamber that contracts as the rudder piston moves to the one side and extends as the steered piston moves to the other side; the left first chamber and the right first chamber; A steering cylinder formed with a fourth chamber that communicates with the other and extends as the steering piston moves toward the one side and contracts as the steering piston moves toward the other side. Unit,
A suspension device comprising:   One of the left first chamber and the right first chamber communicates with the third chamber, and the other of the left first chamber and the right first chamber communicates with the fourth chamber; One of the left first chamber and the right first chamber and the third chamber are shut off, and the other of the left first chamber and the right first chamber is shut off from the fourth chamber; The suspension device according to claim 1, further comprising a first switching valve capable of switching between the two.   One of the left first chamber and the right first chamber communicates with the third chamber, and the other of the left first chamber and the right first chamber communicates with the fourth chamber; A state in which one of the left first chamber and the right first chamber communicates with the fourth chamber, and a state in which the other of the left first chamber and the right first chamber communicates with the third chamber; The suspension device according to claim 1, further comprising a second switching valve capable of switching between the two.   The elastic member that urges the steering piston in a direction in which the left wheel and the right wheel are not steered is provided in at least one of the third chamber and the fourth chamber. The suspension device according to any one of the above.

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