JP5263323B2 - Torsion beam suspension - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a torsion beam type suspension for enhancing rigidity in the bush axial direction in the initial stage of steering. <P>SOLUTION: A rockable quantity regulating means 19 for changing a rockable quantity in the axial direction of an outer cylinder 13, is interposed between an inside end surface in the vehicle width direction of the outer cylinder 13 and an elastic body 15 in a bush 7 arranged in an end part of a trailing arm 8, and a vertical plate 17a. The rockable quantity in the axial direction of the outer cylinder 13 is regulated small in the initial stage of the steering. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

The present invention relates to a torsion beam Suspension of the vehicle.

  As a prior art, there exists a thing of patent document 1, for example. In this technique, when the bush moves relatively in the vehicle width direction by the cornering force acting on the tire, a part of the bush is pressed toward the control slope formed on the vehicle body side. As a result, the axis of the outer cylinder fixed to the front end of the trailing arm is displaced forward relative to the axis of the inner cylinder fixed to the vehicle body, so that the change in the toe-in direction occurs in the rear wheel tire on the turning outer wheel side. To suppress the steering to the oversteer side.

JP 2000-326713 A

However, the technique described in Patent Document 1 has a structure in which the bushing is swung in the axial direction from the initial stage of steering, and thus it is possible to prevent a change in the steering angle in the toe-out direction due to a lateral force generated by the tire. From the beginning, the lateral rigidity of the tire ground contact point is lowered due to the swinging of the bush.
The present invention has been made paying attention to the above points, and it is an object of the present invention to increase the bushing axial rigidity at the initial stage of steering.

In order to solve the above-mentioned problems, the first invention extends in the vehicle front-rear direction, and a front end portion is pivotally attached to the vehicle body through a bush so as to be swingable in the vertical direction, and a wheel is attached to the rear end portion. A pair of left and right trailing arms supported in a freely rotatable state, and a torsion beam extending in the vehicle width direction to connect the left and right trailing arms.
The bush is configured such that an elastic body is interposed between the inner cylinder and the outer cylinder arranged in a nested manner, and the inner bush is opposed to a pair of restraining members arranged opposite to each other on both axial sides of the inner cylinder. The cylinder is bolted, the inner cylinder is fixed to one of the front end of the vehicle body or the trailing arm via the restraining member, and the outer cylinder is fixed to the other of the front end of the vehicle body or the trailing arm,
A swingable amount restricting means for changing the swingable amount of the outer cylinder in the axial direction relative to the restraining member, and changing the swingable amount by the swingable amount restricting means according to the vehicle running state ;
In the bush, the inner cylinder is fixed to the vehicle body via a restraining member, and the outer cylinder is fixed to the other end of the trailing arm front end.
The swingable amount restricting means has an insertion member inserted between the end face of the elastic body or the outer cylinder facing the restraining member and the restraining member, and the inserting member is a shaft of the bush. It is characterized in that it is rotatable around and is connected to the trailing arm or torsion beam via a connecting member .

Next, the second invention extends in the longitudinal direction of the vehicle, and the front end portion is pivotally attached to the vehicle body via the bush so as to be swingable in the vertical direction, and the wheel is rotatable at the rear end portion. A pair of left and right trailing arms supported by and a torsion beam extending in the vehicle width direction and connecting between the left and right trailing arms,
The axial rigidity of the bush is controlled so that the rigidity at the initial stage of steering is higher than the rigidity after the initial stage of steering.

  According to the first aspect of the invention, the suspension is not moved directly by the actuator, but, for example, by restricting the swinging of the bush in the axial direction to a small extent only in the initial stage of steering and increasing the axial rigidity, As a result, it is possible to increase the tire lateral force by increasing the tire side slip angle that is caused to turn outward by the lateral movement of the tire contact point at the initial stage of steering. As a result, it is possible to improve the response of the rear at the beginning of turning.

The second aspect of the invention controls the axial rigidity of the bush by controlling the rigidity at the initial stage of the steering higher than the rigidity after the initial stage of steering, so that the lateral movement amount of the tire contact point at the initial stage of steering can be set small, and the steering After the initial stage, the bush axial rigidity is relatively lowered, so that the rotation angle of the trailing arm is increased, and the tire steer change can be increased.

It is a figure which shows the suspension apparatus for vehicles and vehicle which concern on embodiment based on this invention. It is a figure explaining the rocking | fluctuation possible amount control means which concerns on 1st Embodiment based on this invention. 1 is a schematic plan view showing a suspension device according to an embodiment of the present invention. It is a figure which shows the structure of the rocking | fluctuation control controller which concerns on embodiment based on this invention. It is a figure which shows the relationship between the damper pressure and clearance which concern on 1st Embodiment based on this invention. It is a figure which shows the action | operation area | region which concerns on 1st Embodiment based on this invention. It is a figure which shows operation | movement of the suspension which concerns on 1st Embodiment based on this invention. It is a figure explaining the effect which concerns on 1st Embodiment based on this invention. It is a figure which shows the action | operation area | region which concerns on 2nd Embodiment based on this invention. It is a figure which shows another operation area | region which concerns on 2nd Embodiment based on this invention. It is a figure explaining the rocking | fluctuation possible amount control means which concerns on 3rd Embodiment based on this invention. It is a figure explaining the rocking | fluctuation possible amount control means which concerns on 3rd Embodiment based on this invention. It is a figure which shows the relationship between the convex part and recessed part along the circumferential direction. It is a figure which shows the relationship between the damper pressure and clearance concerning 3rd Embodiment based on this invention. It is a figure which shows the variation of the convex part provided in a movable part. It is a perspective view which shows the bush which concerns on 4th Embodiment based on this invention. It is a figure which shows the relationship between the bush and bracket which concern on 4th Embodiment based on this invention, Comprising: (a) is a front view, (b) is a bottom view, (c) is a side view. It is a perspective view which shows direction of the bush and bracket which concern on 4th Embodiment based on this invention. It is a figure which shows the behavior of the suspension which concerns on 4th Embodiment based on this invention. It is a figure explaining the effect of the structure concerning 4th Embodiment based on this invention. It is a figure which shows the bush 7 and a suspension characteristic. It is a figure explaining another example which concerns on 4th Embodiment based on this invention. It is a figure explaining the convex part which concerns on 5th Embodiment based on this invention. It is a figure explaining the convex part of another example concerning a 5th embodiment based on the present invention. It is a figure explaining the convex part which concerns on 6th Embodiment based on this invention. It is a figure explaining the convex part which concerns on 7th Embodiment based on this invention. It is a perspective view which shows the structure which concerns on 8th Embodiment based on this invention. It is a side view which shows the structure which concerns on 8th Embodiment based on this invention. It is a figure which shows the bush structure which concerns on 8th Embodiment based on this invention. It is a figure explaining the rotary body which concerns on 8th Embodiment based on this invention. It is a figure which shows a shear center. It is a figure which shows operation | movement and an effect | action at the time of an in-phase. It is a figure which shows operation | movement and an effect | action at the time of a reverse phase. It is a figure which shows the effect | action which concerns on 8th Embodiment based on this invention. It is a perspective view which shows another example which concerns on 8th Embodiment based on this invention. It is a figure which shows the bush structure and rotary body which concern on 9th Embodiment based on this invention. It is a perspective view which shows the structure concerning 9th Embodiment based on this invention. It is a side view which shows the structure which concerns on 9th Embodiment based on this invention.

Next, embodiments according to the present invention will be described with reference to the drawings.
(First embodiment)
(Construction)
FIG. 1 is a diagram illustrating a vehicle suspension device 2 according to a first embodiment and a vehicle 1 on which the suspension device 2 is mounted. As shown in FIG. 1, the suspension device of the present invention is applied to the rear suspension of the vehicle body 1.

  As shown in FIG. 1, the suspension device 2 includes a pair of left and right trailing arms 8 extending in the vehicle width direction, and a front end portion of the suspension device 2 via a bush 7 whose axis is directed in the vehicle width direction. It is pivotally attached to the vehicle body so that it can swing in the vertical direction. A wheel 3 is rotatably attached to the trailing end of each trailing arm 8 via an axle. The pair of left and right trailing arms 8 are connected by a torsion beam 4 extending in the vehicle width direction. Reference numeral 5 denotes a suspension spring, and reference numeral 6 denotes a shock absorber, which supports a vertical force. In addition, instead of providing the suspension spring 5 and the shock absorber 6 on the trailing arm 8, a configuration in which these 5 and 6 are provided at positions adjacent to the torsion beam 4 is another embodiment. Reference numeral 100 denotes a steering wheel 100 operated by the driver, and the steering angle of the steered wheels is changed by operating the steering wheel 100.

Next, a structure for attaching the front end portion of the trailing arm 8 to the vehicle body via the bush 7 will be described. In the following description, the left side trailing arm 8 side is described as an example, but the right side mounting structure has the same configuration.
The bush 7 is disposed with its axis directed in the vehicle width direction. As shown in FIG. 2, the bush 7 is disposed between the inner cylinder 14 and the outer cylinder 13 disposed coaxially on the outer periphery of the inner cylinder 14. Is configured. An outward flange 13a is formed in an annular shape at the inner end in the vehicle width direction of the outer cylinder 13. The elastic body 15 is arranged opposite to the elastic body 15a interposed between the inner cylinder 14 and the outer cylinder 13 as described above and the flange 13a of the outer cylinder 13 while continuing to the elastic body 15a. And an annular and flat second elastic body 15b.

  In the bush 7 having the above-described configuration, the outer cylinder 13 is fixed to the front end portion of the trailing arm 8, and the inner cylinder 14 is fixed to the vehicle body via the bracket 17. The bracket 17 is a U-shaped member, and includes left and right vertical plates 17a disposed on both sides in the axial direction of the bush 7, and a connecting portion 17b that connects the vertical plates 17a to each other. It is fixed to the car body by bolts or welding. Each of the pair of left and right vertical plates 17a has a bolt hole at the center, and the inner cylinder 14 is fixed to the bracket 17 by mounting bolts 16 penetrating the left and right vertical plates 17a and the inner cylinder 14. Yes. Reference numeral 18 denotes a nut screwed onto the mounting bolt 16.

  In the present embodiment, the inner cylinder 14 is set to be long so that a predetermined clearance can be ensured between the outer cylinder 13 and the vertical plate 17a on the vehicle inner side, and the elastic body 15 and the outer cylinder 13 are arranged vertically on the vehicle outer side. It is arranged close to the plate 17a side. Then, a swingable amount restricting means 19 that changes the swingable amount of the outer tube 13 in the axial direction between the outer end surface of the outer tube 13 and the elastic body 15 in the vehicle width direction and the vertical plate 17a inside the vehicle. Is intervening.

The swingable amount restricting means 19 includes a drive unit 11 disposed near the vertical plate 17a inside the vehicle in the inner cylinder 14 and a movable part 12 driven by the drive unit 11 to advance and retreat toward the outer cylinder 13 side. Composed.
The drive unit 11 includes a motor inside. The motor is driven by a control signal from the controller 23, the rotational displacement of the motor is converted into a straight movement through the gear, and the movable part 12 is advanced and retracted through the rod 11a.

The movable portion 12 is an annular member that is opposed to the end surface of the outer cylinder 13 and is concentrically disposed with respect to the inner cylinder 14, and the outer cylinder 13 is changed by changing the axial position of the movable portion 12. And the distance between the elastic body 15 and the movable portion 12 is adjusted, and the swingable amount in the axial direction of the outer cylinder 13 (the swingable amount of the bush) is regulated according to the distance (clearance).
In this embodiment, the case where the swingable amount regulating means 19 is provided on the inner side in the vehicle width direction of the bush 7 is illustrated. The configuration in which the swingable amount regulating means 19 is provided on the outer side in the vehicle width direction of the bush 7 or on both sides in the axial direction of the bush 7 is another embodiment. Has the same effect.

  Further, in the present embodiment, as shown in FIG. 3, the axial direction and the axial direction of the bush 7 are not completely matched with the vehicle front-rear direction and the vehicle width direction, and the shaft of the bush 7 is directed outward in the vehicle width direction. The angle is provided so as to go rearward in the vehicle front-rear direction as it goes to. In other words, the shaft of the bush 7 is oriented in the vehicle width direction, but the shaft is arranged slightly inclined in the front-rear direction. Then, the bush rigidity in the axial direction of the bush 7 is lowered, and the intersection of the right and left bushes 7 in the axial direction is provided behind the tire contact point, so that the suspension is caused by the lateral force of the tire so that the suspension is It rotates around the virtual rotation center 41 that is the intersection. Thereby, it becomes easy to steer in the turning direction by the tire lateral force.

As another embodiment, the axial direction of the bush 7 is made completely coincident with the vehicle width direction. In this case, for example, the above-described conventional technique is used in combination to make the structure easy to steer to the understeer side.
A steering angle sensor is arranged in a steering system (not shown). The steering angle sensor detects the steering angle of the steering wheel 100 and outputs a steering angle signal to the swing restriction controller 23.

The shock absorber 6 has a pressure detection sensor for detecting the cylinder internal pressure (damper pressure), and a pressure signal detected by the pressure detection sensor is output to the swing restriction controller 23. FIG. 1 illustrates a case where a pipe for taking out the internal pressure from the shock absorber 6 is provided and the pressure is detected via the pipe.
Further, as shown in FIG. 4, the swing regulation controller 23 includes a clearance amount calculation unit 23A, an operation start determination unit 23B, and a command output unit 23C.

  The clearance amount calculation unit 23A calculates the bush clearance amount based on the damper pressure. In this embodiment, as shown in FIG. 5, the bush clearance is increased in the steady state, that is, the damper pressure is low, and the bush clearance is decreased as the damper pressure increases. That is, the bush clearance amount is obtained from the input damper pressure based on the map or function of the relationship between the damper pressure and the clearance shown in FIG.

Note that when the driver performs a transient steering, the vehicle body performs a sudden roll motion. As a result, the damper moves quickly and the damper pressure rises prior to the actual roll behavior.
The operation start determining unit 23B first determines whether or not the swingable amount regulating means 19 is operated based on the steering angle. In the present embodiment, the determination is made based on the steering angular velocity as shown in FIG. That is, the steering angular velocity is calculated based on the steering angular signal input every predetermined sampling period, and it is determined that the operating condition is satisfied when the calculated absolute value of the steering angular velocity is equal to or greater than the predetermined threshold value S1.

Next, when the operation condition is satisfied, the clearance amount calculated by the clearance amount calculation unit 23A is output to the command output unit 23C. On the other hand, if the operating condition is not satisfied, the initial clearance amount (initial value) of the clearance amount is output to the command output unit 23C.
The predetermined threshold value S1 of the steering angular velocity is a threshold value of the steering angular velocity that is estimated that the driver suddenly operated the steering wheel. By setting the threshold value in this way, it is possible to improve the responsiveness at the time of sudden turning according to the intention of the driver by performing the driver's sudden steering wheel operation.

The command output unit 23C outputs a control signal to the motor of the movable unit 12 so that the input clearance amount is obtained.
The operation start determination unit 23B satisfies the operation condition in the operation start determination unit 23B and adjusts to the clearance amount calculated by the clearance amount calculation unit 23A, for example, after a predetermined time (for example, 1 second to several seconds) has elapsed. When the steering angle exceeds the predetermined angle, the vehicle body roll exceeds the predetermined value, or the steering angular velocity becomes the predetermined value or less, it is determined that the operating condition has been canceled, that is, the operation canceling condition is satisfied. The initial clearance amount is output to the output unit 23C.

(Operation / Action)
The operation of controlling the clearance amount (swingable amount) via the swingable amount regulating means 19 will be described.
In the initial stage of steering when the driver suddenly steers the steering wheel 100 at a predetermined angular velocity or higher, the movable portion 12 is moved closer to the end surface of the outer cylinder 13 to reduce the clearance between them, and the bush 7 is swung in the axial direction. As a result of restricting the possible amount to be small, the axial rigidity of the bush 7 is increased.
At this time, based on the damper pressure, the clearance is increased and the axial rigidity of the bush 7 is set higher as it is determined that the vehicle body rolls suddenly, that is, the lateral force is larger.

If the operation cancellation condition is satisfied, for example, when the steering angular velocity decreases or becomes zero in the subsequent steering, that is, after the initial stage of steering, the clearance between the end surface of the outer cylinder 13 and the annular member is returned to the initial value. Thus, the axial rigidity of the bush 7 returns to the normal state.
In the present embodiment, since it is determined whether or not the steering angular velocity is equal to or higher than a predetermined threshold value, not only in the initial stage of steering that is steered from the straight traveling state, but also from the state of steady turning while maintaining a predetermined steering angle, The above operation is also performed in the early stage of turning change in which the driver further steers with a steered steering wheel to change the turning to change the lane.

From the above operation, the following effects are obtained.
In the initial stage of steering, since the axial rigidity of the bush 7 is increased, the rotation angle of the trailing arm 8 is decreased and the lateral movement amount of the tire contact point is decreased. That is, at the initial stage of steering, the influence of the tire slip angle due to the lateral movement of the tire ground contact point has a great influence on the vehicle behavior. It is possible to reduce the toe change considering the lateral movement (strictly speaking, the lateral speed) (see FIG. 7A).

  On the other hand, after the initial stage of steering, the axial rigidity of the bush 7 decreases, so the rotation angle increases and the tire steering change increases. That is, since the influence of the change in the steering angle on the vehicle behavior is large after the initial stage, the effect of steering in the direction of increasing the lateral force can be obtained (see FIG. 7B). That is, an effect of increasing the rear tire lateral force can be obtained even at the initial stage of steering and after the initial stage.

As a result, it is possible to set the steering angle change due to the lateral rigidity and lateral force of the tire contact point to an appropriate value according to the state of the vehicle. That is, by suppressing the lateral movement of the tire ground contact point that easily affects the initial stage of steering, it is possible to improve the rear following ability at the initial stage of steering, and to ensure the turning stability of the vehicle even in a steady state.
In addition, by providing the virtual rotation center 41 of the suspension behind the rear shaft, it becomes easier to steer in the turning direction due to the tire lateral force (actually, the steering amount does not go to the inside of the vehicle body and the amount of steering to the outside of the vehicle body is suppressed). be able to.).

  FIG. 8 shows the above operation in time series. For comparison with the present embodiment, a response comparison with a torsion beam suspension having no actuator is shown. In the present embodiment, when the steer is applied on the step, the swingable amount regulating means 19 of the bush 7 is operated, and the clearance (swingable amount) of the bush 7 is reduced. Then, the contact point movement amount (movement inward of the turn) with respect to the lateral force of the rear wheel is reduced, and the effect of moving the contact point by the roll of the vehicle body outward of the turn is improved. The left figure of FIG. 8 shows the tire side slip angle α when the ground contact point moves to the inside of the turn. As the moving speed of the contact point to the inside of the turn increases, the tire lateral force toward the inside of the turn decreases. There is an effect.

As described above, by applying this embodiment, it becomes possible to increase the change in the steering angle toward the inside of the turn at the initial stage of steering, and the rear wheel generates a turning force faster than the torsion beam suspension without using the actuator, and the turn It can be seen that the initial rear followability can be improved.
During steady running, the swingable amount restricting means 19 does not operate and the shaft rigidity of the bush 7 is the same as that of the conventional one. Therefore, the compliance is the same as that of the conventional torsion beam suspension, and the steering changes to the inside of the turn. .

  In the case of a technique in which a torsion beam is moved directly using an actuator and a wheel is provided with a toe angle as in the conventional example described above, a large output is required to generate a toe angle without delay from the initial stage of steering. An actuator and a large system are required. On the other hand, in the present embodiment, the bush clearance is only adjusted to regulate the amount of axial swing of the bush 7 before the force generated by the rear wheel becomes large. It is possible to ensure the responsiveness.

By reducing the clearance as the damper pressure increases, the rear suspension characteristics can be set to the desired value before the rear wheels generate force when turning due to sudden turning, which can further increase the effect of sudden turning. Is possible.
In addition, by setting the operation region when the steering speed is equal to or higher than the predetermined threshold S1, the clearance is not adjusted when the damper moves against the driver's intention to turn due to the protrusion, etc. The characteristics of the rear suspension can be changed according to the intention of making a sudden turn and making a quick turn.

In the straight traveling state, by increasing the clearance of the bush 7, the movement of the bush 7 when the wheel moves up and down in the same phase is not hindered, and the riding comfort is improved. On the other hand, in the straight traveling state, the clearance of the bush 7 is narrowed so that the bush clearance is narrowed at the initial stage of steering to reduce the power consumption necessary for improving the steering response, and the movement of the bush 7 is controlled at the initial stage of steering. It is also possible to suppress the roll behavior at the initial stage of pressing and steering.
Here, the vertical plate 17a constitutes a restraining member. The movable part 12 and the drive part 11 constitute an interposed member. The steering angle sensor 21 constitutes a steering angular velocity detection means.

(effect)
(1) The suspension is not moved directly by the actuator, but the swingable amount is changed according to the running state. Here, it is possible to adjust the axial rigidity of the bush to an appropriate value according to the running state.
(2) The adjustment of the swingable amount is realized by changing a distance between the elastic body or the outer cylinder and the restraining member and the elastic body, the outer cylinder or the restraining member. Is done.
(3) For example, only in the initial stage of steering, swinging in the axial direction of the bush is limited to a small extent to increase the axial rigidity, thereby suppressing the movement of the suspension in the lateral direction. It is possible to increase the tire lateral force by increasing the tire side slip angle generated outwardly by turning by the lateral movement. As a result, it is possible to improve the response of the rear at the beginning of turning.

(4) By reducing the swingable amount as the internal pressure of the shock absorber becomes higher, it becomes possible to change the suspension characteristics before the rear wheels generate force when turning by sudden turning. The effect (3) can be further increased.
(5) In addition, by adjusting the swingable amount to be small only when the absolute value of the steering angular velocity is equal to or greater than a predetermined threshold, the damper is contrary to the driver's intention to turn due to riding over a protrusion on the road surface. When the is moved, it is possible to suppress the adjustment in the direction of decreasing the swingable amount.

(6) Further, by changing the axially swingable amount of the outer cylinder with respect to the restraining member according to the vehicle running state, for example, the bushing in the axial direction of the bush is limited to be small only in the initial stage of steering. By increasing the axial rigidity, the lateral movement of the suspension is suppressed, and as a result, the tire side slip angle that is generated by turning the tire contact point laterally at the beginning of steering is increased and the tire lateral force is increased. It becomes possible. As a result, it is possible to improve the response of the rear at the beginning of turning.

(7) Further, by changing the swingable amount based on the operation of the steering wheel 100, for example, only in the initial stage of steering by the operation of the steering wheel 100, the swing of the bush in the axial direction is limited to a small amount. By increasing the directional rigidity, it is possible to suppress the lateral movement of the suspension and, as a result, increase the tire lateral slip angle by increasing the tire side slip angle caused by the lateral movement of the tire contact point at the initial stage of steering, thereby increasing the tire lateral force. It becomes possible. As a result, it is possible to improve the response of the rear at the beginning of turning.

(Second Embodiment)
Next, a second embodiment will be described with reference to the drawings. The same parts as those in the first embodiment will be described with the same reference numerals.
(Constitution)
Although the basic conditions in this embodiment are the same as those in the first embodiment, the determination as to whether or not the operation conditions in the operation start determination unit 23B are satisfied is different.
In the present embodiment, based on the steering angle, when the vehicle is steered to a steering angle that can turn or more, it is determined that the steering is in the initial stage and the operation condition is satisfied.
Further, in the present embodiment, as in the operation map as shown in FIG. 9, it is determined whether or not the absolute value of the steering angle is equal to or less than a predetermined threshold value H1, and if it is not within the predetermined threshold value H1, the above operation condition is satisfied. Judge that not.
Other configurations are the same as those in the first embodiment.

(Function)
In the present embodiment, since the operation region is determined by the operation map of FIG. 9, the swingable amount regulating means 19 is operated only in the region where the steering angle is small to regulate the swing of the bush 7 and the shaft of the bush 7. Since the rigidity is increased, it is possible to increase the response only at the initial stage of steering from the straight traveling state.
In addition, by operating in the range limited to the initial stage of steering, the force that should be generated by the swingable amount regulating means 19 is reduced to adjust the clearance (adjustment of the swing regulation), and the system is reduced in size and weight. It becomes possible to do.

As another embodiment, the determination in the operation map of FIG. 9 is applied to the first embodiment, and also in the first embodiment, it is determined whether or not the absolute value of the steering angle is equal to or less than a predetermined threshold value. If it is not within the predetermined threshold, it is determined that the above operating condition is not satisfied. Even in this case, the same action as described above is obtained. Note that the operating region at this time is as shown in FIG.
Here, the steering angle sensor 21 constitutes a steering angle detection means.

(effect)
(1) When the internal pressure of the shock absorber is greater than or equal to a predetermined value, the swingable amount is increased to operate the swingable amount restricting means only in a region where the steering angle is small, thereby restricting the swinging of the bush. Therefore, it is possible to increase the response only at the initial stage of steering from the straight traveling state.
Also, by operating in the range limited to the initial stage of steering, the force that should be generated by the swingable amount regulating means is reduced in order to adjust the clearance (adjustment of the swing regulation), thereby reducing the size and weight of the system. It becomes possible.

(Third embodiment)
Next, a third embodiment will be described with reference to the drawings. The same parts as those in the first embodiment will be described with the same reference numerals.
(Constitution)
As shown in FIGS. 11 and 12, the swingable amount restricting means 19 of the present embodiment is inserted between the outer cylinder 13 and the vertical plate 17a, and with respect to the inner cylinder 14 via a sliding bearing or the like. The movable unit 12 is rotatably supported, and the drive unit 11 drives the movable unit 12.

The movable part 12 is a disk-shaped member, and has a convex or concave adjusting part 12a on the surface on the outer cylinder 13 side.
The driving unit 11 is fixed to the trailing arm 8, the tip of the rod is connected to the peripheral surface of the movable unit 12, and the movable unit 12 is rotationally displaced by moving the rod forward and backward. . The drive unit 11 rotates and displaces the movable unit 12 by moving the rod back and forth in response to a command from the controller 23.

Further, the second elastic body 15 fixed to the flange 13 in the bush 7 is provided with an uneven portion 24 corresponding to the unevenness of the movable portion 12 as shown in FIG. For example, by providing the movable portion 12 with the convex portion 12a as the adjusting portion and providing the concave portion 24 on the surface of the second elastic body 15 facing the convex portion 12a in the initial state, As the clearance is secured and the movable portion 12 is rotationally displaced, the convex portion 12a and the concave portion 24 are displaced in the circumferential direction, the clearance becomes small or zero, and the axial movement of the outer cylinder 13 of the bush 7 is reduced. Movement is restricted to a small level.
Further, the clearance amount calculation unit 23A of the present embodiment calculates the clearance based on a clearance adjustment map as shown in FIG. That is, when the damper pressure is larger than the steady damper pressure, the clearance is set small, and further, the clearance is set large in the region where the damper pressure is large.

(Operation)
In the present embodiment, the opposing position of the adjustment portion 12a formed on the end surface of the movable portion 12 and the concavo-convex portion 24 formed on the second elastic body 15 is shifted in the circumferential direction by rotationally displacing the movable portion 12, so that the outer The clearance with the cylinder 13 is adjusted.
Moreover, since the drive part 11 is being fixed to the trailing arm 8 which fixed the outer cylinder 13, even if a wheel bounces and rebounds, since the phase of the outer cylinder 13 and the movable part 12 is the same phase, it is movable. The clearance is adjusted by the rotational displacement of the portion 12.

(Function)
Since the movable portion 12 is not stroked in the axial direction, the distance between the left and right vertical plates 17a can be reduced as compared with the first embodiment. As a result, the system can be further downsized.
Due to the uneven shape of the adjusting portion 12a of the movable portion 12, the suspension characteristics can be easily changed.
FIG. 15 shows an example of the convex shape of the movable portion 12. If the convex part is made large as shown in (a), the clearance can be reduced to a range where the suspension stroke is large, or if the convex part is suddenly raised as shown in (b), the suspension characteristics can be made suddenly. It is also possible to change the characteristics on the bounce side and the rebound side if the shape is asymmetric as shown in (c).

As a result of using the clearance adjustment map shown in FIG. 14, when the driver suddenly operates the steering wheel, the damper pressure increases, and the same effect as in the above-described embodiment is obtained (illustration C).
Further, in the region where the damper pressure is high (B in the figure), the clearance is increased. That is, the region where the damper pressure is high is not a region generated by the driver's sudden steering, but is a region generated when overcoming a protrusion or the like, and therefore the bush clearance is widened in that region. As a result, the number of parts hindering the rotation of the trailing arm is reduced when riding over the protrusion, so that the impact from the road surface is not transmitted directly to the vehicle body.
Here, in all the above-mentioned embodiments, the case where the movable part is supported by the vertical plate and is expanded and contracted to the outer cylinder side is illustrated. As another embodiment, the movable part is supported by an outer cylinder or an elastic body, and is expanded and contracted toward the vertical plate. Has the same effect.

(effect)
(1) By increasing the swingable amount when the internal pressure of the shock absorber is greater than or equal to a predetermined threshold, it is possible to suppress the movement of the trailing arm during sudden wheel strokes such as overhanging protrusions. It is possible to prevent a transient input from being transmitted directly to the vehicle body.
(2) Since the swingable amount is adjusted by the rotational displacement, the size of the swingable amount regulating means in the bushing axial direction can be reduced by the amount not stroked in the axial direction.

(Embodiment 4)
Next, a fourth embodiment will be described with reference to the drawings. The same parts as those in the first embodiment will be described with the same reference numerals.
(Construction)
The basic configuration of the present embodiment is the same as that of the torsion beam suspension of the first embodiment and the vehicle on which the suspension is mounted. However, the structure of the bush 7 is different.

Next, a structure for attaching the front end portion of the trailing arm 8 to the vehicle body via the bush 7 will be described. In the following description, the left side trailing arm 8 side is described as an example, but the right side mounting structure has the same configuration.
The bush 7 is disposed with its axis directed in the vehicle width direction. As shown in FIG. 16, the bush 7 is disposed between the inner cylinder 14 and the outer cylinder 13 disposed coaxially on the outer periphery of the inner cylinder 14. Is configured. An outward flange 13a is formed in an annular shape at the inner end in the vehicle width direction of the outer cylinder 13. The elastic body 15 is continuous with the elastic body main body 15a interposed between the inner cylinder 14 and the outer cylinder 13 as described above, and is fixed to the flange 13a of the outer cylinder 13 while continuing to the elastic body main body 15a. An annular and flat plate-like second elastic body 15b is formed.

In the bush 7 having the above-described configuration, the outer cylinder 13 is fixed to the front end portion of the trailing arm 8, and the inner cylinder 14 is fixed to the vehicle body via the bracket 17 as shown in FIGS. Yes. The bracket 17 is a U-shaped member, and includes left and right vertical plates 17a disposed on both sides in the axial direction of the bush 7, and a connecting portion 17b that connects the vertical plates 17a to each other. It is fixed to the car body by bolts or welding. Each of the pair of left and right vertical plates 17 a has a bolt hole at the center, and the inner cylinder 14 is fixed to the bracket 17 by mounting bolts that penetrate the left and right vertical plates 17 a and the inner cylinder 14. . Reference numeral 18 denotes a nut screwed onto the mounting bolt 16.
As shown in FIG. 17, the outer cylinder 13 is disposed close to the vertical plate 17a on the vehicle inner side.

  Furthermore, in the present embodiment, two bush-side convex portions 15c that protrude toward the vertical plate 17a at positions symmetrical to the second elastic body 15b with respect to the bush shaft are provided. Each bush-side convex portion 15 c has a convex shape with a semicircular arc shape when viewed from the radial direction of the bush 7, and has a bowl-shaped contour shape with its top portion extending in the radial direction. The two bush-side convex portions 15c are arranged at symmetrical positions with respect to the axis, that is, in the same diameter direction. The figure illustrates the case where the top portion extends in the horizontal direction. Here, the said bush side convex part 15c comprises a 1st convex part.

  Further, bracket-side convex portions 17c that protrude toward the bush-side convex portions 15c are provided at positions facing the bush-side convex portions 15c on the inner vertical plate 17a. The bracket-side convex portion 17c also has a convex shape with a semicircular arc shape when viewed from the radial direction of the bush 7, and has a bowl-shaped contour shape with its top portion extending in the radial direction in the horizontal direction. Yes. The bracket-side convex portion 17c may be formed by pressing the vertical plate 17a.

  The radial length of the bracket-side convex portion 17c is formed longer than the radial length of the bush-side convex portion 15c. Even if the bush 7 swings in the vehicle front-rear direction, the bush is initially in the initial state. The top part of the side convex part 15c is made to oppose the top part of the bracket side convex part 17c. In this embodiment, the case where the top part of the bush side convex part 15c is contacting the top part of the bracket side convex part 17c in the initial state is illustrated. As another example, a gap is provided between the top of the bush-side convex portion 15c and the top of the bracket-side convex portion 17c in the initial state.

  Further, in the present embodiment, as shown in FIG. 18, the bush axis direction X and the axis direction Y, the vehicle front direction and the vehicle inner side direction do not coincide, and the vehicle longitudinal direction rearward as the bush axis goes outward in the vehicle width direction. An angle is provided so as to go to. In other words, the shaft of the bush 7 is oriented in the vehicle width direction, but the shaft is arranged slightly inclined in the front-rear direction. And the rigidity of the bush 7 in the bush axis direction X is lowered, and the intersection point in the right and left bush axis directions is provided behind the tire grounding point, so that the structure is easy to steer to the understeer side by the lateral force of the tire. . As another embodiment, the bush axis direction X and the axial direction Y, and the vehicle front side and the vehicle inner side direction are matched. In this case, for example, a similar effect can be obtained by using a conventional technique in combination with a structure that easily steers to the understeer side.

(Operation and action)
In the present embodiment, it is possible to change the characteristics of the suspension according to the posture of the vehicle by the opposing bush side convex portion 15c and the bracket side convex portion 17c. That is, the outer cylinder 13 rotates in the direction of the arrow 21 in FIG. 16 according to the stroke of the suspension. By this rotation, the tops of the bracket-side convex portion 17c and the bush-side convex portion 15c are displaced in the circumferential direction, so that a distance (gap) in which the elastic body 15 of the bush 7 can swing in the axial direction with respect to the vertical plate 17a is widened. As a result, the rigidity in the bush axis direction varies depending on the rotation angle of the trailing arm 8.

When the suspension employing the bush 7 and the bracket 17 having the above structure is applied to a vehicle, when the vehicle is turning, when the roll angle of the vehicle body is small (the amount of the arrow 21 in FIG. 16 is small), the opposing convex portions The top portions of the convex portions facing each other are separated in the circumferential direction as the roll angle increases.
That is, in a state where the roll of the vehicle body at the initial stage of steering is small, the outer cylinder 13 abuts on the bracket-side convex portion 17c of the bracket 17 via the second elastic body 15b and the bush-side convex portion 15c. As a result of restricting the relative movement in the axial direction and increasing the axial rigidity of the bush 7, the displacement of the trailing arm 8 in the vehicle width direction is constrained accordingly, and the lateral rigidity of the tire contact point is high. Subsequently, when the roll of the vehicle body increases, the top portions of the opposing convex portions are displaced (separated) from each other in the circumferential direction, thereby allowing relative movement in the axial direction of the outer cylinder 13 and allowing the axial rigidity of the bush 7 to be increased. Becomes lower.

  Here, the above operation is an operation on the turning outer wheel side, but since the bush 7 on the turning inner wheel side is connected via the torsion beam 4, when the axial rigidity on the turning outer wheel side becomes high, The axial rigidity of the bushing 7 on the turning inner ring side is increased by being restricted by the bushing 7 on the turning outer ring side, and the axial rigidity of the bushing 7 on the turning inner ring side is lowered when the axial rigidity of the bushing 7 on the turning outer ring side is lowered. .

  FIG. 19 shows the movement of the trailing arm 8 at the initial stage of steering (a) and after the initial stage of steering (b). The trailing arm 8 rotates about the virtual rotation center 41 due to the lateral force generated by the tire. In the initial stage of steering, the bushing axial direction rigidity is high (the amount of axial movement with respect to the bushing axial force is small), so the rotation angle of the trailing arm 8 is small. On the contrary, after the initial stage of steering, the bushing axial rigidity is low (the amount of axial movement with respect to the bushing axial force is large), so the rotation angle of the trailing arm 8 is large and the steering angle in the direction of reducing the oversteer due to the lateral force. It becomes possible to reduce the change.

  In other words. In the initial stage of steering, the bushing axial rigidity is high, so the rotation angle of the trailing arm 8 is small, and the lateral movement amount of the tire contact point is small. On the other hand, after the initial stage of steering, the bushing axial rigidity decreases, so the rotation angle increases and the tire steering change increases. In the initial stage of steering, the effect of the tire slip angle due to the lateral movement of the tire ground contact point has a great influence on the vehicle behavior. It is possible to reduce the toe change taking into account, and since the influence of the steering angle change has a great influence on the vehicle behavior after the initial stage, it is possible to obtain the effect of steering in the direction of increasing the lateral force. That is, an effect of increasing the rear tire lateral force can be obtained even at the initial stage of steering and after the initial stage.

  As a result, it is possible to set the steering angle change due to the lateral rigidity and lateral force of the tire contact point to an appropriate value according to the state of the vehicle. That is, by suppressing the lateral movement of the tire ground contact point that easily affects the initial stage of steering, it is possible to improve the rear following ability at the initial stage of steering, and to ensure the turning stability of the vehicle even in a steady state.

  FIG. 20 is a diagram showing a change in the toe angle at the initial stage of steering in the case where the present embodiment based on the present invention is applied and in the above-described torsion beam suspension not provided with the opposed convex portions, and the tire caused by the lateral displacement of the tire contact point It is an equivalent steer angle including the side slip angle. The higher the vertical axis is, the more the steering angle is changed to the understeer side, and the steering is started from 1 second on the horizontal axis. By applying the present invention, the amount of lateral movement of the tire contact point at the initial stage of steering is reduced, and an action equivalent to that of steering to the understeer side appears, and the rear followability is improved compared with the conventional torsion beam suspension. It turns out that is possible.

  Here, as the bush 7 to be adopted, as shown in FIG. 21A showing the rigidity in the bush axis direction with respect to the rotation angle of the bush 7, the bush axis rigidity increases as the rotation angle of the bush 7 increases. When used, it has the following effects. That is, when the bush 7 having such characteristics is applied to a vehicle, it is possible to increase the lateral rigidity of the tire ground contact point when the roll motion of the vehicle body is small, and to the oversteer side due to the lateral force as the roll motion occurs. It becomes possible to reduce the steer. This reduces the side slip of the tire to the oversteer side due to the lateral movement of the tire contact point, which has a large effect on the vehicle behavior at the beginning of steering, and reduces the steer to the oversteer side due to side force in the quasi-steady state where steering is increased. Thus, it is possible to improve the rear followability in the initial stage of steering while ensuring the reduction of oversteer in the quasi-steady state.

By providing the convex portions 17c and 13c closer to the outer cylinder 13 on the outer peripheral side, the amount of displacement in the circumferential direction with respect to the rotation angle can be set large. As a result, the change in clearance with the bracket 17 caused by the rotation of the bush 7 is greatly increased. can do. For this reason, it is possible to set a small roll angle for increasing the rigidity at the initial stage of steering.
Further, by providing the bush-side convex portion 15c on the second elastic body 15b at the flange 13a portion position of the outer cylinder 13, the rigidity can be set high.

The bracket 17 is manufactured by, for example, pressing. As a result of the formation of the bracket-side convex portion 17c at the time of pressing, it is possible to improve the performance of the vehicle at a low cost.
Since the bush-side convex portion 15c is made of an elastic body, the generation of abnormal noise when the top portion of the bush-side convex portion 15c comes into contact with the top portion of the bracket-side convex portion 17c is prevented.
Here, in the said embodiment, the case where the bush side convex part 15c is comprised with an elastic body is illustrated. Another example is made of reinforced plastic or metal. In this case, the rigidity is improved accordingly.

  Moreover, in the said embodiment, the case where the outline shape of the convex part seen from the bush axial direction is a semicircular arc shape is illustrated. As another example, the outline is not a part of a perfect circle, but is formed in a semicircular arc shape including a part of an ellipse or a part of a parabola. Or it is trapezoidal. In this case, the top has a certain width in the circumferential direction. Due to the difference in the contour shape of the convex portions, it is possible to adjust the behavior when the convex portions facing each other shift in the circumferential direction.

Moreover, in the said embodiment, the case where a top part extends to radial direction is illustrated. As another example, it is a shape such as a circular truncated cone shape when viewed from the axial direction.
Moreover, in the said embodiment, the case where the outer cylinder 13 of the bush 7 is fixed to the front-end part of the trailing arm 8 is illustrated. As another example, a bracket 17 that supports the inner cylinder 14 is connected to the trailing arm 8 via a bolt, and the outer cylinder 13 is fixed to the vehicle body. Further, the bush-side convex portion 15 c is provided directly on the end surface of the outer cylinder 13.

Moreover, in the said embodiment, the case where the convex parts 17c and 13c which comprise the said group are provided in the vehicle width direction inside is illustrated. As another example, the convex portions 17c and 13c forming the above set are provided on the outer side in the vehicle width direction. Alternatively, it is provided on both the left and right sides.
Here, in the said embodiment, the case where the extending direction of a convex part is horizontally arranged is illustrated. As another example, as shown in FIG. 22, an angle is provided as shown by an arrow 22 in order to limit the suspension layout and realize desired suspension characteristics, without being horizontal.
The bush side convex portion 15c constitutes a first convex portion, the bracket side convex portion 17c constitutes a second convex portion, and the vertical plate 17a constitutes a restraining member. The inclinations 17g and 17h constitute an inclined surface. The flange 13a constitutes the end surface of the outer cylinder. The second elastic body 15b constitutes an elastic body between the outer cylinder end surface and the restraining member.

(Effect of 4th Embodiment)
(1) In the initial stage of steering, the first and second protrusions come into contact with each other to increase the bushing axial rigidity. Therefore, the rotation angle of the trailing arm in a plan view can be kept small, and the tire contact point The lateral movement amount becomes smaller. As a result, it is possible to improve the rear followability at the initial stage of steering.
On the other hand, after the initial stage of steering, the first convex portion and the second convex portion are displaced in the circumferential direction, so that the swing amount is relatively large and the bush axial rigidity is lowered. For this reason, the rotation angle of the trailing arm increases, and the steering change of the tire increases.

(2) When viewed from the bush radial direction, the first convex portion and the second convex portion are provided with inclined surfaces on both sides in the circumferential direction with the top portion interposed therebetween, so that the first convex portion and the second convex portion are in the circumferential direction. At the time of shifting, even if the first convex portion and the second convex portion are displaced while being in contact with each other, the first convex portion and the second convex portion can be smoothly shifted along the inclined surface.
(3) Since each top part of the first convex part and the second convex part extends in the bush radial direction, the contact amount between the first convex part and the second convex part can be set large. .

(4) The first and second protrusions are shifted in the circumferential direction by providing the first and second protrusions at a position closer to the outer cylinder than the inner cylinder when viewed from the bush axis direction. In this case, the change in the clearance between the outer cylinder and the restraining member can be increased with respect to the rotational displacement.
(5) A part of the elastic body is also provided between the end surface of the outer cylinder and the restraining member, and the first convex portion is formed on the elastic body portion provided between the end surface of the outer cylinder and the restraining member. By arranging, the first convex portion can be arranged on the outer diameter side.
(6) By forming the first convex portion with an elastic body, it is possible to suppress the generation of abnormal noise when the first convex portion contacts the mating member.

(7) By locating the intersection in the axial direction of each bush arranged at the front end of each left and right trailing arm in plan view, rearward in the vehicle longitudinal direction from the tire ground contact point of the wheel,
As a result of the rearward center of rotation with respect to the lateral force, the structure is easy to steer to the understeer side due to the lateral force of the tire.
(8) The axial rigidity of the bush is higher at the initial stage of steering than at the initial stage of steering, so that the lateral movement amount of the tire contact point at the initial stage of steering can be set small, and after the initial stage of steering, Since the bush axial rigidity is relatively lowered, the rotation angle of the trailing arm is increased, and the change in tire steer can be increased.

(9) By controlling the axial rigidity of the bush so that the rigidity at the initial stage of steering is higher than the rigidity after the initial stage of steering, the lateral movement amount of the tire ground contact point at the initial stage of steering can be controlled. After the initial stage of steering, the rigidity in the bushing axial direction is relatively lowered, so that the rotation angle of the trailing arm is increased, and the tire steering change can be increased.
(10) When the steering wheel is steered and the vehicle rolls while turning, the above-mentioned actions and effects reduce the tire slip to the oversteer side due to the lateral movement of the tire contact point that has a large influence on the vehicle behavior at the beginning of steering. In the quasi-steady state with increased steering, it is possible to reduce the steer to the oversteer side due to lateral force, and to improve the rear followability at the initial stage of steering while ensuring oversteer reduction in the quasi-steady state. Is possible.

(Fifth embodiment)
Next, a fifth embodiment will be described with reference to the drawings. Components similar to those in the above embodiment will be described with the same reference numerals.
(Constitution)
The basic configuration of the fifth embodiment is the same as that of the fourth embodiment, but the formation of the bush-side convex portion 15c and the bracket-side convex portion 17c forming a set is different.
That is, in this embodiment, only one set of the bush side convex portion 15c and the bracket side convex portion 17c forming a set is used. As a result, only one protrusion is formed in the same radial direction (diameter direction).

FIG. 23 shows a first example of the present embodiment, in which convex portions 17c and 13c are arranged only on the rear side in the vehicle front-rear direction with respect to the bush shaft so that the top portion extends in the horizontal direction.
FIG. 24 shows a second example of the present embodiment, in which the convex portions 17c and 13c are arranged only on the lower side of the bush shaft so that the top portion extends vertically.
Other configurations are the same as those in the first embodiment.

(Operation / Action)
When an axial force is applied to the bush 7 due to the lateral force, the outer cylinder 13 moves in the direction perpendicular to the bush axis, and a load is applied to the convex portions forming a set behind the shaft, so that the same as described above. Further, the rigidity of the bush 7 in the bush axis direction at the initial stage of steering is increased.
At this time, in the present embodiment, since there is no convex portion on the opposite side of the convex portion across the bush shaft, at the initial stage of steering, the bush 7 is located on the opposite side of the convex portion across the bush shaft. The shaft of the bush 7 is tilted by swinging in a direction in which the distance from the vertical plate 17a approaches. That is, when an axial force is applied to the bush 7, a portion where the end surface of the bush 7 is in contact with the end surface of the bracket 17 and a portion where the end surface is not formed are generated. An angle is generated and the axis moves in the direction perpendicular to the axis.

By the above operation and action, the degree of freedom in designing the steering angle change and camber angle change due to the lateral force is increased, and it is possible to realize desired compliance characteristics.
As shown in FIG. 23, when the convex portion is disposed only on the rear side in the vehicle front-rear direction of the bush shaft, the axial rigidity of the bush 7 is increased and the tire ground contact point rigidity is increased at the initial stage of steering. Therefore, the front side of the bush 7 swings in the direction in which the distance between the bush 7 and the vertical plate 17a approaches, and the shaft of the bush 7 tilts in the vehicle front-rear direction. As a result, even in the initial stage of steering, the vehicle steers to the side where oversteer is reduced by the lateral force.

As shown in FIG. 24, when the convex portion is disposed only on the lower side of the bush shaft, the axial rigidity of the bush 7 is increased and the tire contact point rigidity is increased at the initial stage of steering, and the upper portion of the bush shaft is increased. Therefore, the upper side of the bush 7 swings in the direction in which the distance between the bush 7 and the vertical plate 17a approaches, and the shaft of the bush 7 is tilted up and down. As a result, even in the initial stage of steering, it is possible to aim at an effect of causing a camber change equivalent to reducing the oversteer by generating the ground camber angle on the side where the camber angle of the tire increases due to the lateral force.
Further, when the convex portions are provided only at the two points on the rear side of the bushing shaft in the vehicle front-rear direction and the upper side of the bushing shaft, the effects of both (1) and (2) are achieved.

(Effect of 5th Embodiment)
(1) Since each of the first convex portion and the second convex portion is provided at one location in the same radial direction in the bush radial direction, when an axial force acts on the bush, When a portion where the end surface of the outer cylinder and the end surface of the restraining member are in contact with each other and a portion where this is not the case occur, an angle is generated with respect to the shaft of the inner cylinder and the bush moves in the direction perpendicular to the axis. As a result, the degree of freedom in changing the steering angle and camber angle due to the lateral force is increased, and desired compliance characteristics can be realized.

(2) When the tops of the first and second protrusions extend in the vehicle front-rear direction, the axial rigidity of the bush is increased and the tire contact point rigidity is increased in the initial stage of steering. At the same time, since it is not on the front side of the bush shaft, the front side of the bush swings in the direction in which the distance between the bush and the restraining member approaches, and the shaft of the bush tilts in the vehicle front-rear direction. As a result, even in the initial stage of steering, the vehicle steers to the side where oversteer is reduced by the lateral force.

(3) Further, the top of each of the first and second protrusions extends in the vehicle vertical direction. For example, when the protrusion is disposed only on the lower side of the bush shaft, Since the rigidity in the axial direction is increased and the tire contact point rigidity is increased, and there is no upper side of the bushing shaft, the upper side of the bushing swings in the direction in which the distance between the bushing and the restraining member approaches and the shaft of the bushing moves up and down. Tilt in the direction. As a result, even in the initial stage of steering, it is possible to aim at an effect of causing a camber change equivalent to reducing the oversteer by generating the ground camber angle on the side where the camber angle of the tire increases due to the lateral force.

(Sixth embodiment)
Next, a sixth embodiment will be described with reference to the drawings. Components similar to those in the above embodiment will be described with the same reference numerals.
(Constitution)
The basic configuration of the present embodiment is the same as that of the fourth embodiment, but as shown in FIG. 25, the slopes on both sides in the circumferential direction across the top of the bracket-side convex portion 17c are different.

In FIG. 25, in the bush side convex portion 15c on the rear side of the bush shaft, the lower slope 17h is gentler than the upper slope 17g across the top portion 17f. In the bush-side convex portion 15c on the front side of the bush shaft, the upper slope 17h is gentler than the lower slope 17g across the top. Thus, the slopes on both sides across the top are different.
As another example, the slopes on both sides in the circumferential direction across the top of the bush-side convex portion 15c are changed.
Other configurations are the same as in the above embodiment.

(Operation and action)
Since the slopes on both sides of the projections 17g and 17h of the bracket 17 are different, it is possible to change the movement of the trailing arm 8 around the bush 7 as the center of rotation between the bounce side and the rebound side by the roll motion during turning. . As a result, the position of the roll center at the time of turning can be changed.
For example, as described above, it is possible to make the vehicle have a jackdown effect by making the slope 17h on the rebound side gentler when turning.
Here, the inclinations 17g and 17h constitute an inclined surface.
(Effect of 6th Embodiment)
(1) At least one of the first convex portion and the second convex portion is different in the contours of the inclined surfaces on both sides in the circumferential direction, so that the behavior when shifting in the circumferential direction can be changed between bounding and rebounding.

(Seventh embodiment)
Next, a seventh embodiment will be described with reference to the drawings. Components similar to those in the above embodiment will be described with the same reference numerals.
(Constitution)
As shown in FIG. 26, the basic configuration of this embodiment is the same as that of the above embodiment. However, in the bush-side convex portion 15c and the bracket-side convex portion 17c that form a pair, on both sides in the circumferential direction of the bracket-side convex portion 17c. The difference is that the third protrusions 30 are provided.
In FIG. 26, the height of the third convex portion 30 is set higher than that of the bracket-side convex portion 17c.

(Operation / Action)
The bush-side convex portion 15 c moves in the circumferential direction of the convex portion of the bracket 17 by the suspension stroke, approaches one third convex portion 30, and comes into contact with the inclined surface of the third convex portion 30. As a result, the bush-side convex portion 15c is restricted from further movement in the circumferential direction.
As a result of the third convex portion 30 restricting the movement of the bush side convex portion 15c in the circumferential direction, the axial rotation angle of the bush 7 relative to the bracket 17 can be suppressed within a certain value, and the roll angle can be reduced. It becomes possible to suppress.

At this time, it is possible to arbitrarily change the rotational rigidity of the vehicle body in the roll direction by changing the inclination of the inclined surface of the third convex portion 30.
Here, as another example, the third protrusion 30 is not provided on both sides, but is provided only on one side, for example, the bounce side. The restriction can be performed only on the side where the third convex portion 30 is provided.

(Effect of 7th Embodiment)
(1) By providing the third convex portion on at least one of the first convex portion and the second convex portion that form a pair so as to face each other in the circumferential direction, the third convex portion can The axial rotation of the bush is restricted, and it is possible to suppress the movement of the trailing arm that occurs with respect to the rotation center of the bush by the roll motion at the time of turning, thereby suppressing the roll angle.

(Eighth embodiment)
Next, an eighth embodiment will be described with reference to the drawings. Components similar to those in the above embodiment will be described with the same reference numerals.
(Constitution)
The basic configuration of the present embodiment is the same as that of the torsion beam suspension of the first embodiment and the vehicle on which the suspension is mounted. However, as shown in FIGS. 27 and 28, the swingable amount regulating means is different. Here, FIG. 27 is a view of the suspension according to the present embodiment as viewed from the upper left of the vehicle, and shows the configuration of the left wheel. FIG. 28 is a schematic view seen from the left of the vehicle. The structure on the left wheel side will be described below, but the right wheel side has the same structure.

As shown in FIGS. 27 and 28, the swingable amount regulating means of the present embodiment includes a rotating body 64 disposed in the vicinity of the bush 7 and a connecting member 70. The connecting member 70 includes a shaft 60, a foot 62, and a connecting arm 63.
First, from the connection member 70 side, as shown in FIGS. 27 and 28, a shaft 60 made of a torsion bar is disposed along the torsion beam 4 with its axis directed in the vehicle width direction. The shaft 60 has an inner end fixed to the torsion beam 4 via a bracket 61 and an outer end disposed near the trailing arm 8 on the target bush 7 side. When the shaft 60 is deformed in the twisting direction, a reaction force is generated thereby.

Although not shown in FIG. 27, it is preferable that the outer end side of the shaft 60 be supported by the torsion beam 4 in a state where only rotation is allowed. The bracket 67 in FIG. 28 is the support part. By doing so, the vibration on the outer end side of the shaft 60 can be suppressed to a small value.
A foot 62 is fixed to the outer end of the shaft 60, and the foot 62 extends obliquely downward. The foot 62 only needs to have a component that extends vertically. By having a component extending vertically, the tip of the foot 62 can be displaced in the vehicle front-rear direction by transmitting the torsional rotation of the shaft 60. The rear end of the connecting arm 63 is connected to the tip of the foot 62, and the connecting arm 63 extends toward the bush 7. The front end portion of the connecting arm 63 is connected to the rotating body 64.

  As shown in FIGS. 29 and 30, the rotating body 64 is disposed between the vertical plate 17 a inside the vehicle and the outer cylinder 13. That is, the rotating body 64 is a flat plate-like member that is opposed to the end surface of the outer cylinder 13 and that is concentrically arranged with respect to the inner cylinder. The rotating body 64 is rotatable by being supported by a sliding bearing 66 with respect to the inner cylinder. A second convex portion 64 a that projects relatively toward the outer cylinder 13 is formed on the surface of the rotating body 64 on the outer cylinder 13 side. That is, the surface of the rotating body 64 on the outer cylinder 13 side is uneven so that the second protrusion 64a is formed. In addition, a first convex portion 15 c that protrudes relatively to the rotating body 64 side is also formed at a position facing the second convex portion 64 a in the elastic body of the bush 7 or the outer cylinder 13.

As described above, the distal end portion of the connecting arm 63 is connected to the outer peripheral side portion (the lower end portion in the present embodiment) of the rotating body 64. Note that both ends of the connecting arm 63 are connected by free joints. As another embodiment, it connects via the axis | shaft extended in a vehicle width direction. In short, it only has to be connected so as to be swingable in the vehicle front-rear direction around the axis in the vehicle width direction.
Here, the inner end portion of the shaft 60, that is, the fixed point to the torsion beam 4 is preferably arranged at the shear center of the torsion beam 4 determined by the shape of the torsion beam 4 and the arrangement of the torsion beam 4 or in the vicinity thereof. The shear center is a fixed point when a torsional force acts on the torsion beam 4 and the torsion beam 4 is twisted. When the left and right wheels stroke in opposite phases, the shear center hardly moves (see FIG. 31). Therefore, when the left and right wheels stroke in opposite phases, the shaft 60 is not twisted, but the torsion beam 4 is twisted around the shaft 60 axis. This twist causes the flat plate 10 to rotate.

(Operation and action)
When the left and right wheels stroke in the same phase, the left and right trailing arms 8 are displaced up and down in the same phase as shown in FIG. At this time, since the torsion beam 4 does not twist, the connecting member 70 including the shaft 60, the foot 62, and the connecting arm 63 moves up and down integrally with the trailing arm 8. That is, when the trailing arm 8 is pivotally displaced up and down around the bush 7 axis, the outer cylinder 13 integrated with the trailing arm 8 is also displaced, but the rotating body 64 is also synchronized. The same amount of rotational displacement occurs in the same direction. Accordingly, if the first convex portion 15c on the end face of the bush 7 and the second convex portion 64a of the rotating body 64 are set so as to face each other in the stopped state, the change in the vehicle posture due to the difference in the in-vehicle load or the like. Regardless of the fact that the first convex portion 15c and the second convex portion 64a are set in contact or in close proximity to each other, the axial rigidity of the bush 7 can be set high at the initial stage of steering regardless of the vehicle posture. It is possible to increase the lateral rigidity of the contact point.

  On the other hand, when the left and right wheels are stroked in the opposite phase, the torsion beam 4 is twisted as shown in FIG. 33, but the shaft 60 is not subjected to the torsional force even in the opposite phase stroke, so that the twist does not occur. For this reason, even if the trailing arm 8 is pivotally displaced, the rotational displacement generated in the connecting member 70 is reduced, and the outer cylinder 13 and the rotating body 64 that are fixed to the trailing arm 8 according to the torsion are reduced. A rotational displacement difference occurs between the first convex portion 15c and the second convex portion 64a, and the bush 7 axial rigidity is lowered. Since the rotating body 64 is inside the bush 7, the tire can be steered in the toe-in direction (compliance toe-in direction) due to the lateral force generated by the tire due to the clearance.

  As a result, the action shown in FIG. 34 can be obtained, and since the contact point lateral rigidity can be increased at the initial stage of steering regardless of the vehicle posture, the change in the steering angle caused by the contact point moving inward of the turn can be reduced. It is possible to reduce. Further, since the clearance is widened between the end surface of the elastic body of the bush 7 and the rotating body as the vehicle rolls (the tire strokes in the opposite phase) after the initial turning, compliance understeer can be ensured.

(application)
As shown in FIG. 35, disposing the rotating body 64 on the outer side in the vehicle width direction of the bush 7 outer cylinder 13 is another embodiment. Even with this configuration, the above-described effect is obtained.
Further, the fixing point to the torsion beam 4 which is the inner end portion of the shaft 60 is eccentric to the trailing arm 8 side opposite to the center portion in the vehicle width direction of the torsion beam 4, so that the length of the shaft 60 is increased. It is better to make it longer than 1/2 of the length. As the shaft 60 is lengthened, the rotational displacement at the time of the reverse phase stroke can be set larger. Further extending and fixing the inner end portion of the shaft 60 to the trailing arm 8 on the opposite side to further increase the length of the shaft 60 is another embodiment. Since it becomes longer, the rotational displacement difference further increases.
Here, the rotating body 64 constitutes an interposed member. The rotating body 64 and the connecting member 70 constitute swingable amount regulating means.

(effect)
(1) In the bush 7, the inner cylinder is fixed to the vehicle body via a restraining member, and the outer cylinder 13 is fixed to the other front end portion of the trailing arm 8, and the elastic body serves as the swingable amount regulating means. Alternatively, the outer cylinder 13 has an insertion member interposed between the end surface of the outer cylinder 13 facing the restriction member and the restriction member, and the insertion member is rotatable about the axis of the bush 7 and the tray. By connecting to the ring arm 8 or the torsion beam 4 via the connecting member 70, the trailing arm 8 and the connecting member 70 are integrated when the left and right wheels stroke in the same phase due to changes in the load on the vehicle. Due to the displacement, no rotational displacement occurs between the outer cylinder 13 of the bush 7 and the interposed member. That is, even if the interposed member is rotatable, it is possible to suppress the occurrence of rotational displacement between the outer cylinder 13 and the interposed member when the left and right wheels stroke in the same phase.

(2) At this time, the first convex portion 15c protruding toward the restraining member is provided on the end face of the elastic body or the outer cylinder 13 facing the restraining member, and the above-mentioned intervention facing the elastic body of the restraining member or the outer cylinder 13 Provided on the surface of the insertion member is a second convex portion 64a that protrudes toward the elastic body at a position facing the first convex portion 15c, and the connecting member 70 is connected to the outer cylinder 13 when the left and right wheels stroke in opposite phases. By connecting the insertion member and the trailing arm 8 or the torsion beam 4 so that a relative rotational displacement is generated between the intervention member and the interposition member, the rotational displacement can be suppressed as described above during the same phase. At the same time, since the twist of the torsion beam 4 is not transmitted to the connecting member 70 or is small, the trailing arm 8 and the connecting member 70 are not displaced together. Insertion member and the first convex portion 15c rotational displacement is generated and a second convex portion 64a is shifted that between the bush 7 axial stiffness is low.

(3) As the configuration of the connecting member 70, one end is fixed to the torsion beam 4 or the trailing arm 8 and extends in the vehicle width direction, and the foot 62 connected to the other end of the shaft 60; By providing the connecting arm 63 that connects the foot 62 and the insertion member, the left and right wheels rotate reliably between the outer cylinder 13 of the bush 7 and the insertion member when the left and right wheels are stroked in opposite phases. Can be displaced.

(4) By fixing the fixing point on the inner end side of the shaft 60 at the shear center of the torsion beam 4 or in the vicinity thereof, the inner end of the shaft 60 is fixed in the vicinity where the position hardly changes even during the reverse phase stroke. Thus, it is possible to transmit only the torsion bar torsion during the reverse phase, and it is possible to utilize this effect only during the reverse phase.
(5) By making the shaft 60 longer than half the length of the torsion beam 4, the length of the shaft 60 becomes longer, so that it becomes possible to increase the rotational displacement of the torsion bar by a minute amount. It is possible to clarify the effect of in-phase and reverse phase.

(6) By providing the bracket 67 that supports the middle portion of the shaft 60 in a state in which the shaft 60 is rotatable, the bending force received by the shaft 60 in the opposite phase is supported by the bracket 67. As a result, the rigidity of the shaft 60 Can be lowered. Further, the shake of the shaft 60 in the axial direction can be reduced.
(7) The insertion member rotates between the outer cylinder 13 of the bush 7 and the insertion member by the roll of the vehicle by the relative rotation displacement between the outer cylinder 13 when the left and right wheels stroke in opposite phases. Displacement can be generated.

(8) Even when the left and right wheels stroke in the same phase and opposite phase, the insertion member is connected to the trailing arm 8 so that relative rotational displacement does not occur between the outer cylinder 13 and the vehicle load. Even when the left and right wheels change and stroke in the same phase, no rotational displacement is generated between the outer cylinder 13 and the insertion member.
(9) The elastic member or the outer cylinder 13 has an insertion member interposed between the end surface facing the restraining member and the restraining member, and the left and right wheels stroke in opposite phases. As a result, the insertion member can be rotationally displaced relative to the outer cylinder 13 according to the roll state of the vehicle.

(10) The elastic member or the outer cylinder 13 has an insertion member interposed between the end surface of the outer cylinder 13 facing the restriction member and the restriction member. When the wheel strokes in the opposite phase, the relative displacement relative to the outer cylinder 13 allows the insertion member to be rotationally displaced relative to the outer cylinder 13 in accordance with the roll state of the vehicle caused by the steering wheel 100 being steered. .

(Ninth embodiment)
Next, a ninth embodiment will be described with reference to the drawings. Components similar to those in the above embodiment will be described with the same reference numerals.
(Constitution)
The basic configuration of this embodiment is the same as that of the torsion beam 4-type suspension of the eighth embodiment and the vehicle on which the suspension is mounted. However, the swingable amount regulating means is different as shown in FIGS.
That is, in this embodiment, the rotating body 64 is connected to the trailing arm 8 by the connecting member 70. If it demonstrates from the structure of the connection member 70, the rear-end part of the connection arm 63 is being fixed to the trailing arm 8 via the bracket 61. FIG. The connecting arm 63 extends forward in the vehicle front-rear direction, and connects the front end to the rotating body 64.

The rotating body 64 is disposed between the vertical plate 17a inside the vehicle and the outer cylinder 13. The rotating body 64 is a flat plate-shaped member that is opposed to the end surface of the outer cylinder 13 and that is concentrically arranged with respect to the inner cylinder. The rotating body 64 is rotatable by being supported by a sliding bearing 66 with respect to the inner cylinder. The rotating body 64 is disposed in contact with or close to the end face of the elastic body.
Moreover, the vehicle inner front in the outer peripheral part of the rotary body 64 is the inclined surface 64b curved in the vehicle inner direction.
In the present embodiment, the curbs 71 (cavities) are formed on both sides of the elastic body of the bush 7 across the shaft, and the rigidity in the vehicle front-rear direction is set to be low.

(Operation / Action)
By arranging the rotating body 64 in contact with or close to the end face of the elastic body, the rigidity in the axial direction of the bush 7 is high. Thereby, it is possible to improve the responsiveness in the early stage of turning.
The rotating body 64 is rotatable, but is connected to the trailing arm 8 via the connecting arm 63. Therefore, when the left and right wheels make a stroke, the rotating body 64 is connected to the trailing arm 8. Rotating displacement together. Therefore, even if the vehicle posture changes due to a change in the vehicle load, no rotational displacement is always generated between the outer cylinder 13 and the outer cylinder 13 fixed to the trailing arm 8. That is, the elastic body can be brought into close contact with the rotating body 64 regardless of the posture of the vehicle body, and the responsiveness at the initial stage of steering can be improved. Further, since the rotating body 64 and the elastic body are not rubbed when the posture of the vehicle body is changed, the elastic body is not worn by the stroke of the suspension.

When the rear wheel generates a force, if an axial force acts on the bush 7, the outer cylinder 13 slides along the surface of the rotating body 64 in the vehicle front-rear direction due to the deformation of the elastic body. On the turning outer wheel side, the outer cylinder 13 slides forward in the vehicle front-rear direction, and an angle at which the bush 7 is directed in the vehicle turning direction is formed by the inclined surface 64b that is formed in the vehicle inner front of the rotating body 64 and is bent in the vehicle inner direction. Is generated, and the toe angle of the rear wheel is promoted to the side where the lateral force increases, and the steering to the austenite side is suppressed.
Here, the rotating body 64 constitutes an insertion member. The inclined surface 64b constitutes an inclined surface.

(effect)
(1) The surface facing the outer cylinder 13 side of the insertion member is a flat surface, and the outer cylinder 13 is opposed to a part of the outer peripheral side end of the plane of the insertion member or a part of the outer peripheral end. By making the end surface of the surface inclined with respect to the axial direction of the bush 7, when the rear wheel generates a force, the axial force acts on the bush 7 and the outer cylinder 13 rotates due to the deformation of the elastic body. It slides in the vehicle front-rear direction along the surface of the body 64, and the bush 7 is inclined by the slope. By this inclination, it becomes possible to change the compliance after the initial turning to a predetermined state.
(2) When the inclined surface is provided on the front side in the vehicle front-rear direction with respect to the bushing 7 axis and is inclined inward in the vehicle width direction with respect to the bushing 7 axis direct direction, the turning outer wheel side after the initial turning It is possible to make the toe change on the understeer side.

2 Suspension device 3 Wheel 4 Torsion beam 7 Bush 8 Trailing arm 11 Driving part 12 Movable part 12a Adjusting part 13 Outer cylinder 13a Flange 14 Inner cylinder 15 Elastic body 15c Bush side convex part (first convex part)
16 Mounting bolt 17 Bracket 17a Vertical plate (restraint member)
17c Bracket side convex part (second convex part)
19 Swingable amount restricting means 21 Steering angle sensor 22 Pressure detection sensor 23 Swing restriction controller 23A Clearance amount calculating unit 23B Operation start determining unit 23C Command output unit 24 Recess 30 Third convex 60 Shaft 62 Foot 63 Linking arm 64 Rotating body (insertion member)
64a Second convex portion 64b Inclined surface 66 Sliding bearing 70 Connecting member

Claims (7)

A pair of left and right trailing members that extend in the vehicle front-rear direction, and whose front end is pivotally attached to the vehicle body via a bush so as to be swingable in the vertical direction, and are supported by the rear end in a state where the wheels are rotatable. An arm and a torsion beam extending in the vehicle width direction and connecting between the left and right trailing arms,
The bush is configured such that an elastic body is interposed between the inner cylinder and the outer cylinder arranged in a nested manner, and the inner bush is opposed to a pair of restraining members arranged opposite to each other on both axial sides of the inner cylinder. The cylinder is bolted, the inner cylinder is fixed to one of the front end of the vehicle body or the trailing arm via the restraining member, and the outer cylinder is fixed to the other of the front end of the vehicle body or the trailing arm,
Further, a swingable amount restricting means for changing the swingable amount of the outer cylinder in the axial direction relative to the restraining member is provided, and the swingable amount by the swingable amount restricting means is changed according to the vehicle running state. ,
In the bush, the inner cylinder is fixed to the vehicle body via a restraining member, and the outer cylinder is fixed to the other end of the trailing arm front end.
The swingable amount restricting means has an insertion member inserted between the end face of the elastic body or the outer cylinder facing the restraining member and the restraining member, and the inserting member is a shaft of the bush. It is rotatable around and connected to the trailing arm or torsion beam via a connecting member,
A first convex portion protruding toward the restraining member is provided on an end face of the elastic body or outer cylinder facing the restraining member, and a first convex is formed on the surface of the insertion member facing the elastic body or outer cylinder of the restraining member. Providing a second convex portion projecting toward the elastic body at a position facing the portion,
The connecting member connects the insertion member and the trailing arm or the torsion beam so that a relative rotational displacement occurs between the outer cylinder and the insertion member when the left and right wheels stroke in opposite phases. Characteristic torsion beam suspension. The connecting member has one end fixed to a torsion beam or a trailing arm and extending in the vehicle width direction, a foot connected to the other end of the shaft, and a connection connecting the foot and the insertion member. The torsion beam suspension according to claim 1 , further comprising an arm. 3. The torsion beam suspension according to claim 2 , wherein the one end side fixed point of the shaft is arranged at or near the shear center of the torsion beam. The shaft is a torsion beam type suspension according to claim 2 or claim 3, characterized in that longer than the length of half of the torsion beam. The torsion beam type suspension according to any one of claims 2 to 4 , wherein a bracket is provided for supporting a midway portion of the shaft in a state where the shaft is rotatable. A pair of left and right trailing members that extend in the vehicle front-rear direction, and whose front end is pivotally attached to the vehicle body via a bush so as to be swingable in the vertical direction, and are supported by the rear end in a state where the wheels are rotatable. An arm and a torsion beam extending in the vehicle width direction and connecting between the left and right trailing arms,
The bush is configured such that an elastic body is interposed between the inner cylinder and the outer cylinder arranged in a nested manner, and the inner bush is opposed to a pair of restraining members arranged opposite to each other on both axial sides of the inner cylinder. The cylinder is bolted, the inner cylinder is fixed to one of the front end of the vehicle body or the trailing arm via the restraining member, and the outer cylinder is fixed to the other of the front end of the vehicle body or the trailing arm,
Further, a swingable amount restricting means for changing the swingable amount of the outer cylinder in the axial direction relative to the restraining member is provided, and the swingable amount by the swingable amount restricting means is changed according to the vehicle running state. ,
In the bush, the inner cylinder is fixed to the vehicle body via a restraining member, and the outer cylinder is fixed to the other end of the trailing arm front end.
As the swingable amount restricting means, the elastic member or the outer cylinder has an insertion member interposed between the end surface facing the restraining member and the restraining member,
The insertion member is rotatable about the bush axis independently of the outer cylinder and the inner cylinder, and the insertion member is rotated and displaced with the stroke of the left and right wheels. Connect to the trailing arm or torsion beam via a connecting member,
The surface of the insertion member facing the outer cylinder side is a flat surface, and a part of the outer peripheral side end portion of the surface of the insertion member, or an end surface of the outer cylinder facing a part of the outer peripheral side end portion is a bush. A torsion beam suspension characterized in that the surface is inclined with respect to the axial direction. The torsion beam suspension according to claim 6 , wherein the inclined surface is provided on the front side in the vehicle front-rear direction with respect to the bushing shaft and is inclined inward in the vehicle width direction with respect to the direction perpendicular to the bushing shaft.

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