JP5761578B2 - Vehicle suspension system - Google Patents

Description

  The present invention relates to a vehicle suspension device that generates a damping force according to vertical movement (for example, bounce or roll) of a vehicle body.

  Conventionally, as a suspension device of this type of vehicle, a shock absorber is interposed between the left wheel and the vehicle body, and between the right wheel and the vehicle body, and the left wheel and the vehicle are separated from the shock absorber. The left hydraulic cylinder interposed between the vehicle body, the right hydraulic cylinder interposed between the right wheel and the vehicle body, and the upper cylinder chamber of the left hydraulic cylinder and the lower cylinder chamber of the right hydraulic cylinder communicate with each other. A first oil passage to be connected; a second oil passage for connecting the upper cylinder chamber of the right hydraulic cylinder and the lower cylinder chamber of the left hydraulic cylinder; and a third oil for connecting the first oil passage and the reservoir tank to each other. A damping mechanism including a road, a fourth oil path that connects the second oil path and the reservoir tank, and a variable throttle provided in each of the third oil path and the fourth oil path. In relative vertical movement Was something is provided with a control mechanism for controlling the limiting level of the variable throttle (e.g., see Patent Document 1).

  Further, as a technique related to the hydraulic cylinder provided in the suspension device, there is a technique described in Patent Documents 2 to 4 which are cited below. The hydraulic cylinders described in Patent Documents 2 and 3 are composed of a double cylinder type including a slidable piston and a piston rod, and the volume of the cylinder chamber divided into two chambers by the piston changes due to the movement of the piston. . The rigidity of the automobile suspension is controlled by generating a flow of hydraulic oil through a port provided in the hydraulic cylinder.

  The fluid pressure damper included in the suspension device described in Patent Document 4 is also configured as a double cylinder type including a slidable piston and a piston rod. This fluid pressure damper also changes the volume of the oil chamber (corresponding to the “cylinder chamber”) partitioned by the piston in the cylinder due to the movement of the piston, and suppresses changes in the posture of the automobile by generating a flow of hydraulic oil. To do.

JP-A-5-193331 (FIG. 2) JP 2005-133902 A (9th paragraph) JP 2007-205416 A (8th paragraph) Japanese Patent No. 4740086 (10th paragraph)

According to the above-described conventional suspension device for a vehicle, both the shock absorber and the damping mechanism are provided side by side, so that there is a problem that the structure around the wheel is complicated.
Furthermore, it is necessary to detect the relative vertical movement (amount, speed, etc.) between the wheel and the vehicle body, and to control the damping mechanism that accompanies it.

  In the hydraulic cylinders described in Patent Documents 2 and 3, the cylinder outer cylinder and the port are integrally formed. On the other hand, the fluid pressure damper described in Patent Document 4 has a hollow rod interior and uses the rod interior as an oil passage. For this reason, since it is necessary to connect piping to the outer cylinder of a cylinder, when mounting in a vehicle is considered, it is necessary to arrange | position any one of piping, a rod, and a dust seal part below a vehicle. For this reason, the stepping stones, dust, muddy water, etc. may cause deterioration or damage to the pipe or rod and the dust seal.

  Accordingly, an object of the present invention is to provide a vehicle suspension apparatus that can solve the above-mentioned problems, simplify the structure around the wheels, and can reduce the impact without performing complicated control. It is in.

The characteristic configuration of the present invention includes a left hydraulic cylinder interposed between the left wheel and the vehicle body and a right wheel and the vehicle body in the pair of left and right wheels of at least one of the front wheel and the rear wheel. A first hydraulic passage that connects the right hydraulic cylinder, the upper cylinder chamber of the left hydraulic cylinder, and the lower cylinder chamber of the right hydraulic cylinder; the upper cylinder chamber of the right hydraulic cylinder; and the lower cylinder chamber of the left hydraulic cylinder Are provided in each accumulator so as to discharge hydraulic fluid from each accumulator, a second oil passage communicating with each other, an accumulator provided in communication with each of the first oil passage and the second oil passage, respectively. The first valve for the accumulator and the flow rate of the hydraulic oil entering the respective accumulators are adjusted to create a load larger than the load applied to the hydraulic oil by the first valve for the accumulator. A second valve for accumulator provided in each accumulator to provide an oil, the conjunction is provided in correspondence to each other to port of the cylinder chambers of the left hydraulic cylinder and the right hydraulic cylinder, each port of the respective cylinder chambers And a differential pressure mechanism for making a difference in the pressure of the hydraulic oil, and when the hydraulic oil is discharged from a cylinder chamber having an orifice, a check valve, and a port provided with the differential pressure mechanism. in Rutokoro to have a a damping force valve that generates a damping force by applying a load to the hydraulic oil.

According to such a characteristic configuration, when a roll is generated in the vehicle body, a large resistance pressure acts as the hydraulic oil flowing out from the left and right cylinder chambers passes through the second valve for accumulator together. As a result, a large damper effect acts on the hydraulic cylinder, the roll of the vehicle body can be suppressed, and it becomes easy to ensure running stability.
With the stabilizer function of this configuration, the conventional stabilizer bar can be omitted.

With such a configuration, in the case where bounce occurs in the vehicle body, the differential pressure mechanism is provided so that a small resistance pressure acts on the hydraulic oil passing through each port in a predetermined direction compared to when rolling. As a result, the bounce of the vehicle body can be attenuated by the damper effect of the hydraulic cylinder, and a good riding comfort can be obtained.

In addition, according to this configuration, it is possible to provide an absorber function, so that the conventional absorber can be omitted or downsized, and the conventional stabilizer bar can be omitted by having the above-described stabilizer function. In addition to this, the structure around the wheel can be simplified.

In addition, when the vehicle body rolls, the lower cylinder chamber of one hydraulic cylinder and the upper cylinder chamber of the other hydraulic cylinder communicating with the same contract together to reduce the volume. And is moved to one accumulator. In the present invention, since the second valve for an accumulator that applies a load when the hydraulic oil enters the accumulator is provided, when the hydraulic oil moves, it corresponds to each port of the cylinder together with the second valve for the accumulator. Even the differential pressure mechanism can generate flow resistance, and as a result, the damping effect on the roll of the vehicle body can be exerted more strongly.
As a result, it is possible to exert a damping force suitable for rolling and bounce of the vehicle body in a passive system without providing a complicated mechanical mechanism or control mechanism, ensuring driving stability and good To ensure a comfortable ride.

Further, according to such a characteristic configuration, it is possible to generate appropriate damping force characteristics with respect to the input from the road surface by effectively using the resistance characteristics of the orifice and the damping force valve.
Therefore, for example, when the input speed acting on the hydraulic cylinder is slow, the orifice mainly performs the damping, and when the input speed is fast, the impact damping can be achieved by the damping force valve in addition to the orifice. As a result, it is possible to achieve appropriate attenuation regardless of the magnitude of the road surface input acting on the wheels, and it is possible to achieve both running stability and improved ride comfort.

In the differential pressure mechanism, it is preferable that a set pressure when the hydraulic oil is discharged from the cylinder chamber is set larger than a set pressure when the hydraulic oil enters the cylinder chamber.

With this configuration, the damping force can be increased when the hydraulic oil is discharged from the cylinder chamber, while the hydraulic oil can smoothly enter when the hydraulic oil enters the cylinder chamber. It is possible to effectively generate a damping force suitable for bounce suppression.

  The differential pressure mechanism and the load mechanism having the first accumulator valve and the second accumulator valve can be unitized.

According to such a characteristic configuration, by integrating the differential pressure mechanism and the load mechanism into a unit, it is possible to reduce the number of parts such as pipes, improve the attachment to the vehicle body, and achieve space saving. Is possible.
Moreover, it becomes easy to prevent parts such as the valves constituting the differential pressure mechanism and the load mechanism from being exposed, and the durability of the parts can be improved.

  Further, the second valve for accumulator applies a larger load than the load applied to the hydraulic oil by the first valve for accumulator provided in the accumulator on the side different from the accumulator provided with the second valve for accumulator. It is also possible to configure.

  With such a configuration, the damper effect acting on the hydraulic cylinder can be increased, so that the roll of the vehicle body can be suppressed and traveling stability can be easily ensured.

  Furthermore, a suspension mechanism that suspends the wheel may be provided.

  With such a configuration, it is possible to increase the level of roll damping, rigidity, etc. of the vehicle, and the range of damping force tuning such as rolls, bounces, etc. is widened. Miniaturization and mounting flexibility are also improved.

  Further, each of the left hydraulic cylinder and the right hydraulic cylinder is provided with a port for supplying and discharging hydraulic oil from each of the upper cylinder chamber and the lower cylinder chamber at a position separated from the lower fixed portion. It is preferable.

  With such a configuration, it is possible to make it difficult to be affected by jumping stones and muddy water splashes associated with the traveling of the vehicle. Therefore, durability and reliability can be improved.

  Further, the port for supplying and discharging the hydraulic oil in the upper cylinder chamber and the port for supplying and discharging the hydraulic oil in the lower cylinder chamber are disposed on the side of the fixed portion of the rod provided on the upper side. Is preferred.

  With such a configuration, it is possible to eliminate the influence of jumping stones and muddy water splashes accompanying traveling of the vehicle. Therefore, durability and reliability can be improved.

  An upper cylinder chamber oil passage for supplying and discharging hydraulic oil in the upper cylinder chamber and a lower cylinder chamber oil passage for supplying and discharging hydraulic oil in the lower cylinder chamber are provided on the radially inner side of the rod. It is preferable that

  With such a configuration, the upper cylinder chamber oil passage and the lower cylinder chamber oil passage can be protected by the rod. Therefore, it is not necessary to take measures to increase the durability of the upper cylinder chamber oil passage and the lower cylinder chamber oil passage, and therefore an increase in cost can be avoided.

  In addition, the rod has a cylindrical member coaxially on the radially inner side of the rod, the lower cylinder chamber oil passage is formed on the radially inner side of the cylindrical member, and the inner peripheral surface of the rod and the tubular shape It is preferable that the upper cylinder chamber oil passage is formed between the outer peripheral surface of the member.

  With such a configuration, it is possible to configure the upper cylinder chamber oil passage and the lower cylinder chamber oil passage only by arranging cylinders having different diameters on the same axis. Therefore, it can be configured with a simple structure.

Schematic diagram of the suspension device according to the first embodiment Explanatory drawing showing the relationship between the pressure and flow rate of the damping force valve Explanatory diagram showing the relationship between piston speed and damping force The schematic diagram which shows the effect | action of the suspension apparatus which concerns on 1st Embodiment. The schematic diagram which shows the effect | action of the suspension apparatus which concerns on 1st Embodiment. The schematic diagram which shows the effect | action of the suspension apparatus which concerns on 1st Embodiment. The schematic diagram which shows the suspension apparatus which concerns on 2nd Embodiment. The schematic diagram which shows the effect | action of the suspension apparatus which concerns on 2nd Embodiment. The schematic diagram which shows the effect | action of the suspension apparatus which concerns on 2nd Embodiment. The schematic diagram which shows the effect | action of the suspension apparatus which concerns on 2nd Embodiment. The schematic diagram which shows the effect | action of the suspension apparatus which concerns on 2nd Embodiment. The schematic diagram which shows the effect | action of the suspension apparatus which concerns on 2nd Embodiment. The schematic diagram which shows the suspension apparatus which concerns on 3rd Embodiment. Schematic diagram showing a hydraulic cylinder The schematic diagram which shows the effect | action of the suspension apparatus of another embodiment. Schematic diagram showing a hydraulic cylinder of another embodiment

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

1. Vehicle suspension device 1-1. First Embodiment FIG. 1 shows a vehicle incorporating an example of a “vehicle suspension device” of the present invention, and is a schematic diagram showing a pair of front wheels (or rear wheels). The suspension device S of the vehicle can be applied to a pair of left and right wheels of at least one of a front wheel and a rear wheel.
The left wheel 2A and the right wheel 2B are attached to the vehicle body 1 so as to be rotatable around the rotation axis Xa and Xb, respectively.
The wheel 2 is attached to the vehicle body 1 so as to be movable up and down via the left hydraulic cylinder 4 and the right hydraulic cylinder 5.
Specifically, the wheel 2 is attached to the vehicle body 1 via a link member 3 that can swing up and down from the lower end 1 a of the vehicle body 1.
The left hydraulic cylinder 4 and the right hydraulic cylinder 5 have upper end portions attached to the support portion 1b of the vehicle body 1, and lower end portions attached to the intermediate portion 3a of the link member 3. It is configured so that it can be attenuated by expanding and contracting relative to the vertical relative movement.

The suspension device S includes a left hydraulic cylinder 4 and a right hydraulic cylinder 5 that are attached across the left and right support portions 1b of the vehicle body 1 and the intermediate portion 3a of each of the left and right link members 3. The first oil passage 6 that connects the upper cylinder chamber 4U and the lower cylinder chamber 5L of the right hydraulic cylinder 5 to each other, and the upper cylinder chamber 5U of the right hydraulic cylinder 5 and the lower cylinder chamber 4L of the left hydraulic cylinder 4 are connected to each other. The second oil passage 7 and the ports 110 and 111 of the cylinder chambers 4U, 4L, 5U, and 5L are provided corresponding to the ports 110 and 111, and the pressure of the hydraulic oil R is made different for each of the ports 110 and 111. The accumulators 9 and 10 are provided so as to communicate with the differential pressure mechanism 8 and the first oil passage 6 and the second oil passage 7, respectively. That is, the accumulators 9 and 10 are a pair.
The accumulators 9 and 10 generate system pressure and supply the hydraulic oil R from the cylinder chambers 4U, 4L, 5U and 5L, and conversely supply the hydraulic oil R to the cylinder chambers 4U, 4L, 5U and 5L. . Moreover, it is provided in order to give the roll rigidity of the vehicle. The containers of the accumulators 9 and 10 are filled with gas, and act as a gas spring by changing the volume of the gas depending on the volume of the hydraulic oil R. That is, when the hydraulic oil R flows into the accumulators 9 and 10, the gas is compressed, a repulsive force due to the spring force of the gas is added to the hydraulic oil R, and it becomes possible to impart the roll rigidity (stabilizer function) of the vehicle. .

The first oil passage 6 and the accumulator 9 are connected in communication by a third oil passage 11, while the second oil passage 7 and the accumulator 10 are connected in communication by a fourth oil passage 12.
The third oil passage 11 and the fourth oil passage 12 are each provided with a load mechanism 13 that applies a load when the hydraulic oil R enters the accumulators 9 and 10. In addition, between the third oil passage 11 and the fourth oil passage 12, the hydraulic oil volume between the oil passages increases and decreases, and the movement of the hydraulic oil R is allowed with respect to the vehicle inclination caused by the difference. A communication mechanism 14 for balancing is provided.

  Both the hydraulic cylinders 4 and 5 are divided into upper and lower cylinder chambers by pistons P, respectively, and the piston rod Pr is provided so as to penetrate the lower cylinder chambers 4L and 5L, respectively.

The differential pressure mechanism 8 allows only the hydraulic oil R to enter the cylinder chamber, and allows only the hydraulic oil R to be discharged from the cylinder chamber, and opens when the differential pressure exceeds a predetermined pressure value. However, a damping force valve 8b for adjusting the flow rate based on the differential pressure and an orifice 8c for providing resistance at the time of discharge are provided.
The relationship between the differential pressure of the damping force valve 8b and the flow rate is as shown in FIG.
The check valve 8a and the damping force valve 8b are provided with a spring 15 that closes and applies a biasing force to the valve body. If the biasing force of the spring 15 is large, the flow resistance of the hydraulic oil R increases. When the urging force is small, the flow resistance of the hydraulic oil R may be reduced, or a leaf valve structure may be used. However, the check valve 8a is not set to have a high flow resistance so that the hydraulic oil R can easily flow when it flows.
The damping force valve 8b changes the valve opening amount according to the flow rate and the differential pressure, and generates a corresponding damping force. For example, the damping force valve 8b is configured to apply an elastic biasing force by a leaf spring or the like in the valve closing direction. Can be used.
In the present embodiment, the differential pressure mechanism 8 has the flow resistance when the hydraulic oil R is discharged from the cylinder chambers 4U, 4L, 5U, 5L so that the hydraulic oil R enters the cylinder chambers 4U, 4L, 5U, 5L. It is set larger than the flow resistance. That is, rather than the damping force when the hydraulic oil R 1 enters the cylinder chambers 4U, 4L, 5U, and 5L via the check valve 8a, the hydraulic oil R passes through the cylinder chambers 4U, 4L, and 4L via the damping force valve 8b. The damping force when discharged from 5U and 5L is set larger.

Further, the relationship between the piston speed and the flow resistance (corresponding to the damping force) is controlled by the flow resistance by the orifice 8c when the piston speed is low, as shown in FIG. 3, by the damping force valve 8b and the orifice 8c. When the piston speed increases, the flow resistance change is added after the damping force valve 8b is opened.
As can be seen from this figure, the appropriate damping desired for the piston speed can be obtained.

  As shown in FIG. 1, the load mechanism 13 corresponds to a damping force valve 13a (corresponding to the “second valve for accumulator” according to the present invention) and a check valve 13b (corresponding to “the first valve for accumulator” according to the present invention). ) And an orifice 13c. The check valve 13b is provided in each accumulator 9, 10 so as to discharge the hydraulic oil R from the respective accumulator 9, 10. Therefore, the check valve 13b only allows the hydraulic oil R to be discharged from the accumulators 9 and 10. The damping force valve 13a is provided in the accumulators 9 and 10 so as to adjust the flow rate of the hydraulic oil R that enters the accumulators 9 and 10, respectively. Therefore, only the hydraulic oil R is allowed to enter the accumulators 9 and 10 and the flow rate is adjusted based on the pressure value while the valve is opened when the pressure exceeds a predetermined pressure value. The damping force valve 13a and the check valve 13b are provided with a spring that applies a closing biasing force to the valve body. If the spring biasing force is large, the flow resistance of the hydraulic oil R increases, and conversely the biasing force. Is small, the flow resistance of the hydraulic oil R may be small, and a leaf valve structure may be used. Further, the damping force valve 13a is configured to apply a larger load to the hydraulic oil R than the load of the check valve 13b. That is, the check valve 13b is set to have a low flow resistance so that the hydraulic oil R flows smoothly from the accumulators 9 and 10, and the damping force valve 13a is configured to generate an appropriate damping force.

  Here, the damping force valve 13a on the accumulator 9 side is configured to apply a load larger than the load applied to the hydraulic oil by the check valve 13b on the accumulator 9 side, and the damping force valve 13a on the accumulator 10 side is configured to be an accumulator. It is not limited to what is comprised so that the load larger than the load which the 10th side check valve 13b gives to hydraulic fluid may be given. The damping force valve 13a provided in the accumulator 9 applies a load larger than the load applied to the hydraulic oil by the check valve 13b provided in the accumulator 10 on the side different from the accumulator 9 provided with the damping force valve 13a. It is also possible to configure. Further, the damping force valve 13a provided in the accumulator 10 has a load larger than the load applied to the hydraulic oil by the check valve 13b provided in the accumulator 9 on the side different from the accumulator 9 provided with the damping force valve 13a. It can also be configured to provide.

  Further, the damping force valve 13a on the accumulator 9 side is configured to apply a load larger than the load applied to the hydraulic oil by the check valve 13b on the accumulator 9 side, and the damping force valve 13a on the accumulator 10 side is configured to be an accumulator. The check valve 13b on the 10th side is configured to give a load larger than the load given to the hydraulic oil, and the damping force valve 13a provided in the accumulator 9 is a load given to the hydraulic oil by the check valve 13b provided in the accumulator 10. The damping force valve 13a provided in the accumulator 10 may be configured to apply a load larger than the load applied to the hydraulic oil by the check valve 13b provided in the accumulator 9. Of course it is possible.

  Further, the orifice 13c can adjust the damping force in the region where the piston speed is low, similarly to the orifice 8c. The orifice 13c is not always necessary and may be omitted depending on the performance required for the suspension device S.

Next, the operation state of the suspension device S with respect to the movement of the wheel 2 will be described.
As the movement of the wheel 2, as shown in FIG. 4, both the left hydraulic cylinder 4 and the right hydraulic cylinder 5 extend, and the left hydraulic cylinder 4 and the right hydraulic cylinder 5 as shown in FIG. A “shrink bounce” that shrinks and a “roll” that stretches one of the left hydraulic cylinder 4 and the right hydraulic cylinder 5 as shown in FIG.

“Elongation bounce” occurs when both wheels 2 rebound, and the hydraulic oil R is discharged from the lower cylinder chambers 4L and 5L and passes through the corresponding differential pressure mechanisms 8 as shown in FIG. , Flows into the upper cylinder chambers 5U, 4U of the opposite cylinder.
At this time, since the absolute value of the amount of expansion / contraction is equal between the one lower cylinder chamber 4L (5L) and the other upper cylinder chamber 5U (4U), it is discharged from the lower cylinder chamber 4L (5L). The hydraulic oil R corresponding to the volume of the piston rod Pr flows smoothly from the accumulator 10 (9) to the upper cylinder chamber 5U (4U) via the check valve 13b.
In the flow of the hydraulic oil R described above, a damping force is generated mainly by discharging the hydraulic oil R through the differential pressure mechanism 8 corresponding to the lower cylinder chambers 4L and 5L.
At this time, the differential pressure mechanism 8 corresponding to the upper cylinder chambers 4U and 5U has the check valve 8a set so that the hydraulic oil R flows smoothly in order to ensure a sufficient fluid pressure in the cylinder chamber. ing.

The “shrink bounce” occurs when both wheels 2 bounce, and the hydraulic oil R is discharged from the upper cylinder chambers 4U and 5U and passes through the corresponding differential pressure mechanisms 8 as shown in FIG. , Flows into the lower cylinder chambers 5L, 4L of the opposite cylinder.
At this time, since the absolute value of the amount of expansion / contraction is equal between one upper cylinder chamber 4U (5U) and the other lower cylinder chamber 5L (4L), the piston entering the upper cylinder chamber 4U (5U) The hydraulic oil R corresponding to the volume of the rod Pr flows into the accumulator 9 (10) via the load mechanism 13.
In the flow of the hydraulic oil R described above, the hydraulic oil R is discharged via the differential pressure mechanism 8 corresponding to the upper cylinder chambers 4U and 5U, thereby generating a damping force.
At this time, the flow rate of the hydraulic oil R corresponding to the volume of the rod passing through the load mechanism 13 is small, and the damping force generated by the load mechanism 13 is small. Further, the differential pressure mechanism 8 corresponding to the lower cylinder chambers 4L and 5L has a check valve 8a set to a characteristic that allows the hydraulic oil R to flow smoothly in order to ensure a sufficient fluid pressure in the cylinder chamber.

“Roll” occurs when the vehicle turns to the right or left, and here, a case where the vehicle turns to the left will be described.
The left wheel 2A (turning inner ring) moves relatively in the rebound direction, and the hydraulic oil R is discharged from the lower cylinder chamber 4L as shown in FIG. 6, and the corresponding differential pressure mechanism 8 and load mechanism It flows into the accumulator 10 via 13.
The right wheel 2B (turning outer wheel) moves relatively in the bounce direction, and the hydraulic oil R is discharged from the upper cylinder chamber 5U as shown in FIG. 6, and the corresponding differential pressure mechanism 8 and load mechanism It flows into the accumulator 10 via 13.
At this time, by the differential pressure mechanism 8 corresponding to the lower cylinder chamber 4L of the left hydraulic cylinder 4, the differential pressure mechanism 8 corresponding to the upper cylinder chamber 5U of the right hydraulic cylinder 5, and the load mechanism 13 corresponding to the accumulator 10, A big damping effect can be demonstrated.
The hydraulic oil R is supplied from the accumulator 9 to the upper cylinder chamber 4U of the left hydraulic cylinder 4 and the lower cylinder chamber 5L of the right hydraulic cylinder 5, and the corresponding differential pressure mechanisms 8 are provided in the cylinder chamber. In order to sufficiently secure the hydraulic pressures of 4L and 5U, the check valves 8a of the upper cylinder chamber 4U and the lower cylinder chamber 5L are set so that the hydraulic oil R flows smoothly.

The above-described characteristics of the impact damping force with respect to “elongation bounce”, “shrink bounce”, and “roll” can be expressed as shown in FIG.
The broken line indicates “elongation bounce” and “shrink bounce”, the solid line indicates “roll”, the horizontal axis indicates the piston speed, and the vertical axis indicates the damping force.
As the piston speed changes, the linearity is bent, and the damping effect by the orifice 8c of the differential pressure mechanism 8 appears in the initial steep area. In the area of gentle gradient, the damping effect by each differential pressure mechanism 8 and load mechanism 13 appears.

According to the suspension device S of the present embodiment, “bouncing” and “ Good attenuation can be achieved with respect to the “roll”, and it is possible to ensure both running stability and good riding comfort.
Further, according to the suspension device S of the present embodiment, the absorber function and the stabilizer function can be combined, and the stabilizer bar can be omitted, so that the structure around the wheel 2 can be simplified.

1-2. Second Embodiment Next, a second embodiment according to the present invention will be described. FIG. 7 shows a vehicle body 1 incorporating the suspension device S of the present embodiment. Although the suspension apparatus S of the first embodiment includes the differential pressure mechanism 8, the suspension apparatus S of the second embodiment differs from the first embodiment in that a suspension mechanism 50 is provided instead of the differential pressure mechanism 8. Different. Below, a different point is mainly demonstrated.

  Even in the suspension device S of the present embodiment, the left hydraulic cylinder 4 and the right hydraulic cylinder 5 are attached across the left and right support portions 1b of the vehicle body 1 and the intermediate portions 3a of the left and right link members 3. Therefore, the left hydraulic cylinder 4 and the right hydraulic cylinder 5 are respectively provided between the position where the support portion 1b of the vehicle body 1 is connected and the suspension mechanism 50 when viewed in the horizontal direction. Further, the upper cylinder chamber 4U of the left hydraulic cylinder 4 and the lower cylinder chamber 5L of the right hydraulic cylinder 5 are connected in communication by the first oil passage 6, and the upper cylinder chamber 5U of the right hydraulic cylinder 5 and the lower cylinder of the left hydraulic cylinder 4 are connected. The chamber 4 </ b> L is connected in communication with the second oil passage 7. The first oil passage 6 and the second oil passage 7 are respectively provided with accumulators 9 and 10 in communication.

  The first oil passage 6 and the accumulator 9 are connected in communication by a third oil passage 11, and the second oil passage 7 and the accumulator 10 are connected in communication by a fourth oil passage 12. A load mechanism 13 is provided in each of the third oil passage 11 and the fourth oil passage 12. A communication mechanism 14 is also provided across the third oil passage 11 and the fourth oil passage 12.

  Also in this embodiment, the load mechanism 13 includes a damping force valve 13a, a check valve 13b, and an orifice 13c, and the damping force valve 13a applies a larger load to the hydraulic oil R than the load of the check valve 13b. It is configured. Thereby, the function of the stabilizer which suppresses the roll of the vehicle body 1 is realized.

  Here, as described above, the present embodiment does not include the differential pressure mechanism 8 that attenuates the bounce of the vehicle body 1. Therefore, in the suspension device S of the present embodiment, the suspension mechanism 50 is provided to reinforce the absorber function. The suspension mechanism 50 is provided in parallel with each of the left hydraulic cylinder 4 and the right hydraulic cylinder 5 and suspends the wheel 2. The suspension mechanism 50 includes a so-called “shock absorber” including a hydraulic damper 51 and a spring 52. Since a well-known shock absorber can be used, the description about the structure is abbreviate | omitted. In this embodiment, a double cylinder type hydraulic damper 51 is used, and a piston valve 60 having a check valve Va1 and a damping force valve Va2 and a base valve 70 having a check valve Va3 and a damping force valve Va4 are provided. The damping force generated by the damping force valve Va4 is set to be larger than the damping force generated by the damping force valve Va2, and the damping force generated by the check valve Va1 and the check valve Va3 is extremely smaller than the damping force generated by the damping force valve Va2. Is set to be

Next, the operation state of the suspension device S with respect to the movement of the wheel 2 will be described.
As the movement of the wheel 2, as shown in FIG. 8, both the left hydraulic cylinder 4 and the right hydraulic cylinder 5 extend, and the left hydraulic cylinder 4 and the right hydraulic cylinder 5 as shown in FIG. "Shrink bounce" that shrinks, "roll" that one of the left hydraulic cylinder 4 and right hydraulic cylinder 5 stretches as shown in FIG. 10, and "shrink bounce" by single wheel input as shown in FIG. Then, “elongation bounce” by single wheel input as shown in FIG. 12 will be described.

“Elongation bounce” occurs when both wheels 2 rebound, and the hydraulic oil R is discharged from the lower cylinder chambers 4L and 5L as shown in FIG. 8, and the upper cylinder chambers 5U and 4U of the opposite cylinder are discharged. Flow into.
At this time, since the absolute value of the amount of expansion / contraction is equal between the one lower cylinder chamber 4L (5L) and the other upper cylinder chamber 5U (4U), it is discharged from the lower cylinder chamber 4L (5L). The hydraulic oil R corresponding to the volume of the piston rod Pr flows smoothly from the accumulator 10 (9) to the upper cylinder chamber 5U (4U) via the check valve 13b.
At this time, the hydraulic damper 51 of the suspension mechanism 50 also tends to extend both left and right. For this reason, a damping force is generated by the damping force valve Va2.

  As described above, in the “elongation bounce”, almost no damping force is generated by the left hydraulic cylinder 4 and the right hydraulic cylinder 5, but only the damping force by the hydraulic damper 51 of the suspension mechanism 50 is generated. In this way, it is possible to generate an appropriate damping force on the extension side, to secure the grounding property of the vehicle, and to ensure both running stability and good riding comfort.

“Shrink bounce” occurs when both wheels 2 bounce, and the hydraulic oil R is discharged from the upper cylinder chambers 4U and 5U as shown in FIG. 9, and the lower cylinder chambers 5L and 4L of the opposite cylinders. Flow into.
At this time, since the absolute value of the amount of expansion / contraction is equal between one upper cylinder chamber 4U (5U) and the other lower cylinder chamber 5L (4L), the piston entering the upper cylinder chamber 4U (5U) The hydraulic oil R corresponding to the volume of the rod Pr flows into the accumulator 9 (10) via the load mechanism 13.
At this time, the flow rate of the hydraulic oil R corresponding to the volume of the rod passing through the load mechanism 13 is small, and the damping force generated by the load mechanism 13 is small.
At this time, the hydraulic damper 51 of the suspension mechanism 50 also tries to contract both left and right. For this reason, a damping force is generated by the damping force valve Va4.

  As described above, in the “shrink bounce”, almost no damping force is generated by the left hydraulic cylinder 4 and the right hydraulic cylinder 5, but only the damping force by the hydraulic damper 51 of the suspension mechanism 50 is generated. In this way, it is possible to generate an appropriate damping force on the contraction side, to ensure the grounding property of the vehicle, and to ensure both running stability and good riding comfort.

“Roll” occurs when the vehicle turns right or left, and here, a case where the vehicle turns right will be described.
The left wheel 2A (turning outer wheel) moves relatively in the bounce direction, and the hydraulic oil R is discharged from the upper cylinder chamber 4U and is passed through the load mechanism 13 to the accumulator 9 as shown in FIG. Inflow.
The right wheel 2B (turning inner ring) moves relatively in the rebound direction, and the hydraulic oil R is discharged from the lower cylinder chamber 5L as shown in FIG. Inflow.
At this time, the damping force valve 13a of the load mechanism 13 can exert a great damping effect.

  The hydraulic oil R is smoothly supplied from the accumulator 10 to the lower cylinder chamber 4L of the left hydraulic cylinder 4 and the upper cylinder chamber 5U of the right hydraulic cylinder 5.

  At this time, the hydraulic damper 51 on the left wheel 2A side strokes in the contracting direction, and the hydraulic damper 51 on the right wheel 2B side strokes in the extending direction. Therefore, a damping force is generated by the damping force valve Va4 in the hydraulic damper 51 on the left wheel 2A side, and a damping force is generated by the damping force valve Va2 in the hydraulic damper 51 on the right wheel 2B side.

  As described above, the “roll” acts so that the damping force by the hydraulic damper 51 of the suspension mechanism 50 is added to the damping force by the left hydraulic cylinder 4 and the right hydraulic cylinder 5. In this way, it is possible to increase the damping force on the roll to suppress the roll, to ensure the grounding property of the vehicle, and to ensure both running stability and good riding comfort.

The “shrink bounce” of single wheel input occurs when either the left or right wheel 2 bounces when the left or right wheel 2 gets over a protrusion or the like. Here, a case where the left wheel 2 gets over a protrusion or the like will be described.
The left wheel 2A moves in the bounce direction. In this case, as shown in FIG. 11, the right wheel 2B hardly strokes. Since the lower cylinder chamber 5L of the right hydraulic cylinder 5 needs to have enough pressure to compress and retract the coil, the hydraulic oil R discharged from the upper cylinder chamber 4U of the left hydraulic cylinder 4 hardly flows and passes through the load mechanism 13. Then, it flows into the accumulator 9.
At this time, a damping force corresponding to the stroke amount and the stroke speed is generated by the damping force valve 13a of the load mechanism 13.

  The hydraulic oil R is smoothly supplied from the accumulator 10 to the lower cylinder chamber 4L of the left hydraulic cylinder 4. In this example, there is almost no inflow of hydraulic oil into the lower cylinder chamber 5L and outflow of hydraulic oil from the upper cylinder chamber 5U. Therefore, in order to facilitate understanding, the flow of these hydraulic oils is broken in FIG. Is shown.

  At this time, the hydraulic damper 51 on the left wheel 2A side strokes in the contraction direction, but the hydraulic damper 51 on the right wheel 2B side hardly moves. For this reason, in the hydraulic damper 51 on the left wheel 2A side, a damping force according to the stroke amount and the stroke speed is generated by the damping force valve Va4.

  As described above, in the “shrink bounce” of the single wheel input, the damping force by the damping force valve 13a of the load mechanism 13 on the accumulator 9 side, and the damping force by the damping force valve Va4 of the hydraulic damper 51 on the left wheel 2A side. Occurs. Thus, the damping force is generated, the grounding property of the vehicle is ensured, and both the running stability and the good riding comfort can be achieved.

Single wheel input “elongation bounce” occurs when either the left or right wheel 2 rebounds when passing through a recess or the like on either the left or right wheel 2. Here, a case where the left wheel 2 passes through a depression or the like will be described.
The left wheel 2A moves in the rebound direction. In this case, as shown in FIG. 12, the right wheel 2B hardly strokes. Since the upper cylinder chamber 5U of the right hydraulic cylinder 5 needs pressure to lift the vehicle body 1, the hydraulic oil R discharged from the lower cylinder chamber 4L of the left hydraulic cylinder 4 hardly flows and passes through the load mechanism 13. Flows into the accumulator 10.
At this time, a damping force corresponding to the stroke amount and the stroke speed is generated by the damping force valve 13a of the load mechanism 13.

  The hydraulic oil R is smoothly supplied from the accumulator 9 to the upper cylinder chamber 4U of the left hydraulic cylinder 4. In this example, there is almost no outflow from the hydraulic oil to the lower cylinder chamber 5L and no inflow of the hydraulic oil to the upper cylinder chamber 5U. Therefore, in FIG. Is shown.

  At this time, the hydraulic damper 51 on the left wheel 2A side strokes in the extending direction, but the hydraulic damper 51 on the right wheel 2B side hardly moves. For this reason, in the hydraulic damper 51 on the left wheel 2A side, a damping force corresponding to the stroke amount and the stroke speed is generated by the damping force valve Va2.

  As described above, in the “elongation bounce” of the single wheel input, the damping force by the damping force valve 13a of the load mechanism 13 on the accumulator 10 side and the damping force by the damping force valve Va2 of the hydraulic damper 51 on the left wheel 2A side. Occurs. Thus, the damping force is generated, the grounding property of the vehicle is ensured, and both the running stability and the good riding comfort can be achieved.

1-3. Third Embodiment Next, a third embodiment according to the present invention will be described. FIG. 13 shows the vehicle body 1 incorporating the suspension device S of the present embodiment. The suspension device S of the first embodiment has been described as including the differential pressure mechanism 8. Further, the suspension device S of the second embodiment has been described as including the suspension mechanism 50 instead of the differential pressure mechanism 8. The suspension device S of the third embodiment differs from the first and second embodiments in that both the differential pressure mechanism 8 and the suspension mechanism 50 are provided. Since the configuration is the same as that of the first embodiment and the second embodiment, description thereof will be omitted.

  Even with such a configuration, it is possible to generate a damping force appropriately in accordance with the state of the vehicle, as in the first and second embodiments. Therefore, it is possible to ensure the grounding property of the vehicle, and to ensure both running stability and good riding comfort.

2. Next, the structure of the hydraulic cylinder used for the left hydraulic cylinder 4 and the right hydraulic cylinder 5 will be described. The left hydraulic cylinder 4 and the right hydraulic cylinder 5 can be the same. Therefore, in the following, an example of the left hydraulic cylinder 4 will be described. A cross-sectional view schematically showing the configuration of the left hydraulic cylinder 4 is shown in FIG.

  The left hydraulic cylinder 4 includes an outer cylinder 41, an inner cylinder 42, a piston P, and a piston rod Pr. The outer cylinder 41 and the inner cylinder 42 are formed in a cylindrical shape, and are formed so that the outer diameter of the inner cylinder 42 is smaller than the inner diameter of the outer cylinder 41. The outer cylinder 41 and the inner cylinder 42 are arranged coaxially. Therefore, an annular space 90 is formed between the inner peripheral surface of the outer cylinder 41 and the outer peripheral surface of the inner cylinder 42.

  The lid portion 80 is welded so that one side in the axial direction of the outer cylinder 41 is closed. A cylindrical axially extending part 81 extending toward the axially central side of the outer cylinder 41 is formed inside the lid part 80, and the inner cylinder 42 is fitted into the axially extending part 81. Positioned. On the inner peripheral surface of the axially extending portion 81, a seal member 85 is provided at a portion that contacts the outer peripheral surface of the inner cylinder 42. As a result, one axial side of the annular space 90 can be liquid-tightly configured. Here, a fixing portion 101 for attaching the left hydraulic cylinder 4 to the link member 3 is welded to the outside (axially outside) of the lid portion 80.

  A first cap member 82 is fitted on the other side in the axial direction of the inner cylinder 42 so that the outer peripheral surface is in contact with the inner peripheral surface of the outer cylinder 41, and is positioned with respect to the inner peripheral surface of the outer cylinder 41. Is done. The first cap member 82 is supported by the second cap member 83 from the outside in the axial direction (the side opposite to the fixed portion 101). The outer peripheral surface of the second cap member 83 is provided in contact with the inner peripheral surface of the outer cylinder 41. A Teflon rod seal 84 is disposed on the radially inner side of the second cap member 83 via an O-ring 131. Thereby, the sealing performance can be enhanced while reducing the sliding resistance when the piston rod Pr slides. A seal member 86 is disposed on the outer peripheral surface of the second cap member 83. Thereby, it becomes possible to form between the 2nd cap member 83 and the outer cylinder 41 liquid-tightly.

By configuring as described above, the annular space 90 can be configured in a liquid-tight manner. In the annular space 90, oil or air is sealed in a liquid-tight manner. Thereby, the heat insulation of the left hydraulic cylinder 4 can be improved. Further, it is possible to prevent distortion of the sliding surface of the piston P (outer circumferential surface) by flying stones or the like from the outside.

  On the inner side in the radial direction of the inner cylinder 42, a piston P and a piston rod Pr, which is coaxially fixed to the piston P on one side in the axial direction, are provided. The piston rod Pr is formed so that its outer diameter is smaller than the inner diameter of the inner cylinder 42, and its outer peripheral surface is slidable on the inner peripheral surfaces of the first cap member 82 and the second cap member 83. A region surrounded by the inner peripheral surface of the inner cylinder 42, the piston P, and the lid 80 corresponds to the lower cylinder chamber 4L.

  In the piston rod Pr, a cylindrical tube 93 (corresponding to the “tubular member” of the present invention) is disposed coaxially on the radially inner side. A cap 94 is fastened and fixed to the other side of the piston rod Pr with screws. The cap 94 is formed with a port 111 for supplying and discharging the hydraulic oil R from the upper cylinder chamber 4U and a port 110 for supplying and discharging the hydraulic oil R from the lower cylinder chamber 4L. The cap 94 is welded with a fixing portion 102 that attaches the left hydraulic cylinder 4 to the support portion 1 b of the vehicle body 1. Therefore, the ports 110 and 111 can be disposed at positions separated from the lower fixing portion 101.

  As described above, the piston rod Pr is fastened and fixed by the cap 94. For this reason, the fixing | fixed part 102 is corresponded to the fixing | fixed part of piston rod Pr provided in the upper side. Therefore, in this embodiment, the ports 110 and 111 can be disposed on the fixed portion 102 side of the piston rod Pr.

  One side in the axial direction of the pipe 93 is inserted through the piston P, and is in communication with the lower cylinder chamber 4L through a space inside the pipe 93 in the radial direction. A space on the radially inner side of the pipe 93 serves as a lower cylinder chamber oil passage 171 for supplying and discharging the hydraulic oil R in the lower cylinder chamber 4L. The other axial side of the pipe 93, that is, the other axial side of the lower cylinder chamber oil passage 171 is communicated with the port 110 via the radial oil passage 181. The space surrounded by the outer peripheral surface of the pipe 93, the inner peripheral surface of the inner cylinder 42, the piston P, and the first cap member 82 corresponds to the upper cylinder chamber 4U.

  An annular space is formed between the outer peripheral surface of the tube 93 and the inner peripheral surface of the piston rod Pr. One side of the annular space communicates with the upper cylinder chamber 4U via the radial oil passage 182, and the other side communicates with the port 111. Therefore, this annular space becomes an upper cylinder chamber oil passage 170 for supplying and discharging the hydraulic oil R. As described above, in the present embodiment, the upper cylinder chamber oil passage 170 and the lower cylinder chamber oil passage 171 are provided on the radially inner side of the piston rod Pr.

  The upper cylinder chamber 4U and the lower cylinder chamber 4L are filled with hydraulic oil R, and the volumes of the upper cylinder chamber 4U and the lower cylinder chamber 4L change as the piston P moves in the inner cylinder 42. In response to this change, the hydraulic oil R is supplied and discharged from the ports 110 and 111. In accordance with the movement of the piston P, the piston rod Pr also moves along the axial direction. For this reason, the bush 120 is disposed at a position facing the outer peripheral surface of the piston rod Pr of the first cap member 82.

  A small-diameter portion 41 </ b> A that reduces the inner diameter is formed at the axial end of the outer cylinder 41. A disk-shaped iron plate 150 is disposed on the axial position side (the second cap member 83 side) of the small diameter portion 41A. The iron plate 150 is positioned with its outer peripheral surface in contact with the inner peripheral surface of the outer cylinder 41. A rubber member 151 attached to the iron plate 150 is disposed on the radially inner side of the small diameter portion 41A, and a metal spring 152 that biases the rubber member 151 radially inward is disposed on the outer peripheral surface of the rubber member 151. Has been. Thereby, the penetration | invasion of the dust from the outside through the radial inside of the small diameter part 41A can be prevented.

  A disc-shaped iron plate 140 is disposed on the axial end surface of the iron plate 150 on the second cap member 83 side. The outer peripheral surface of the iron plate 140 is positioned in contact with the inner peripheral surface of the outer cylinder 41. A rubber seal member 121 is disposed on the inner peripheral surface of the iron plate 140 and the axial end surface on the second cap member 83 side. The seal member 121 extends in the axial direction along the piston rod Pr. This extending portion is urged radially inward by the metal spring 142 from the radially outer side. In addition, a resin bush 191 is disposed on the radially inner side of the seal member 121 on which the iron plate 140 is disposed on the radially outer side. As a result, it is possible to improve the sealing performance particularly at a low pressure, and to prevent the hydraulic oil R in the left hydraulic cylinder 4 from leaking through the outer peripheral surface of the piston rod Pr. Therefore, the hydraulic oil R can be prevented from leaking outside. With the above configuration, the piston rod Pr can be moved coaxially with the piston P.

  A cover member 160 is disposed on the cap 94 so as to cover at least part of the outer peripheral surface of the piston rod Pr and the outer cylinder 41. Thereby, it becomes possible to protect the outer peripheral surface of the piston rod Pr from dust or the like.

3. Other Embodiments Other embodiments will be described below.

The differential pressure mechanism 8 and the load mechanism 13 in the first embodiment are not limited to being individually formed, and for example, as shown in FIG. May be.
The unit Y can be installed simply by providing the oil passage connection portions 16 corresponding to the respective ports and connecting each oil passage to the oil passage connection portion 16.
In this way, by integrating the differential pressure mechanism 8 and the load mechanism 13 as a unit, exposure of parts such as valves can be prevented to improve the durability of the parts, and the unit Y can be attached to the vehicle body 1. It can be improved and space saving can be realized.

  The differential pressure mechanism 8 and the load mechanism 13 are not limited to the specific configuration described in the previous embodiment, and may include a configuration for electrically controlling the valve opening state.

  In the above embodiment, the configuration of the left hydraulic cylinder 4 (right hydraulic cylinder 5) is schematically shown in FIG. However, the scope of application of the present invention is not limited to this. For example, as shown in FIG. 16, the present invention can naturally be applied to a hydraulic cylinder having a McPherson-Strut type suspension mechanism 50. In such a case, it is preferable to fasten and fix to the vehicle body 1 using the bracket 202 instead of the fixing portion 102. It is also possible to fasten and fix the cap 94 and the pipe 93 with the nut 203.

  In the said embodiment, the suspension apparatus S demonstrated and demonstrated the example in case the front wheel is equipped. However, the scope of application of the present invention is not limited to this. The present invention can be applied to the rear wheel, and naturally can be applied to both the front wheel and the rear wheel.

  In the embodiment described above, the first accumulator valve 13b is a check valve, and the second accumulator valve 13a is a damping force valve. However, the scope of application of the present invention is not limited to this. In other words, the first valve 13b for the accumulator is not a check valve, and can naturally be constituted by a damping force valve that applies a load smaller than the load of the damping force valve as the second valve 13a for the accumulator.

  In addition, as mentioned above, although the code | symbol was written in order to make contrast with drawing convenient, this invention is not limited to the structure of an accompanying drawing by this entry. In addition, it goes without saying that the present invention can be carried out in various modes without departing from the gist of the present invention.

  The present invention can be applied to a vehicle suspension device for front wheels and rear wheels.

DESCRIPTION OF SYMBOLS 1 Car body 2 Wheel 2A Left wheel 2B Right wheel 4 Left hydraulic cylinder 4U Upper cylinder chamber 4L Lower cylinder chamber 5 Right hydraulic cylinder 5U Upper cylinder chamber 5L Lower cylinder chamber 6 1st oil path 7 2nd oil path 8 Differential pressure mechanism 8a Check valve 8b Damping force valve 8c Orifice 9 Accumulator 10 Accumulator 13 Load mechanism 13a Damping force valve (second valve for accumulator)
13b Check valve (first valve for accumulator)
50 Suspension mechanism 93 Tube (tubular member)
101 fixed part (lower fixed part)
102 fixed portion 110 port 111 port 170 oil passage for upper cylinder chamber 171 oil passage for lower cylinder chamber R hydraulic oil S suspension device (vehicle suspension device)

Claims (9)

In the pair of left and right wheels of at least one of the front wheel and the rear wheel,
A left hydraulic cylinder interposed between the left wheel and the vehicle body;
A right hydraulic cylinder interposed between the right wheel and the vehicle body;
A first oil passage that connects the upper cylinder chamber of the left hydraulic cylinder and the lower cylinder chamber of the right hydraulic cylinder in communication with each other;
A second oil passage for connecting the upper cylinder chamber of the right hydraulic cylinder and the lower cylinder chamber of the left hydraulic cylinder in communication with each other;
Accumulators respectively provided in communication with the first oil passage and the second oil passage;
A first valve for an accumulator provided in each accumulator so as to discharge hydraulic oil from each accumulator;
A second valve for an accumulator provided in each accumulator so as to apply a larger load to the hydraulic oil than the load applied to the hydraulic oil by the first valve for the accumulator by adjusting the flow rate of the hydraulic oil entering each of the accumulators. When,
A differential pressure mechanism that is provided corresponding to each port of each cylinder chamber of the left hydraulic cylinder and the right hydraulic cylinder, and that makes a difference in the input / output pressure of hydraulic oil for each port of the cylinder chamber ;
The differential pressure mechanism includes a damping force valve that generates a damping force by applying a load to the hydraulic oil when the hydraulic oil is discharged from a cylinder chamber having an orifice, a check valve, and a port provided with the differential pressure mechanism. suspension device for a vehicle that Yusuke. The differential pressure mechanism is configured such that a set pressure when hydraulic oil is discharged from a cylinder chamber having a port in which the differential pressure mechanism is provided is when the hydraulic oil enters the cylinder chamber having a port in which the differential pressure mechanism is provided . The vehicle suspension apparatus according to claim 1 , wherein the suspension apparatus is set to be larger than a set pressure. The vehicle suspension apparatus according to claim 1 or 2 , wherein the differential pressure mechanism and a load mechanism having the first valve for accumulator and the second valve for accumulator are unitized. The second valve for accumulator is configured to give a load larger than the load given to the hydraulic oil by the first valve for accumulator provided in the accumulator on the side different from the accumulator provided with the second valve for accumulator. The vehicle suspension device according to any one of claims 1 to 3 . The vehicle suspension apparatus according to any one of claims 1 to 4 , further comprising a suspension mechanism that suspends the wheel. Each of the left hydraulic cylinder and the right hydraulic cylinder has a port for supplying and discharging hydraulic oil from each of the upper cylinder chamber and the lower cylinder chamber disposed at a position separated from a lower fixing portion. The vehicle suspension apparatus according to any one of claims 1 to 5 . 2. A port for supplying and discharging hydraulic oil in the upper cylinder chamber and a port for supplying and discharging hydraulic oil in the lower cylinder chamber are disposed on the side of a fixed portion of a rod provided on the upper side. The vehicle suspension apparatus according to any one of claims 1 to 6 . An upper cylinder chamber oil passage for supplying and discharging hydraulic oil in the upper cylinder chamber and a lower cylinder chamber oil passage for supplying and discharging hydraulic oil in the lower cylinder chamber are provided on the radially inner side of the rod. The vehicle suspension apparatus according to claim 7 . The rod has a cylindrical member coaxially on the radially inner side of the rod, the lower cylinder chamber oil passage is formed on the radially inner side of the cylindrical member, and the inner circumferential surface of the rod and the cylindrical member The vehicle suspension device according to claim 8 , wherein the upper cylinder chamber oil passage is formed between the outer peripheral surface and the outer peripheral surface.

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