JP2007223519A - Torsion beam type suspension, its control method and automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance stability in turning utilizing biasing force biased to a bushing. <P>SOLUTION: The torsion beam type suspension is provided with a torsion bar extending in a vehicle width direction; left and right leg parts integrally provided at both left and right sides of the torsion bar and extending in a direction intersecting with an axis of the torsion bar; and a link member for connecting the leg parts and an outer cylinder of the bushing and turnably connected to the leg parts and the outer cylinder respectively. When a connection point of the link member to the outer cylinder is defined as a fist connection point and a connection point of the link member to the leg part is defined as a second connection point, the first connection point is arranged below a linear line passing through an axis of the bushing and the second connection point in side view. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a torsion beam type vehicle suspension device, a control method thereof, and a vehicle including the vehicle suspension device.

The torsion beam type suspension is configured such that the front end portions of the left and right trailing arms are elastically supported by a vehicle body via a bush so as to be swingable, and the left and right trailing arms are connected by a torsion beam. When the left and right wheels make strokes in opposite phases, the torsion beam is twisted, and a moment is generated in a direction that prevents it.
Furthermore, in the technique described in Patent Document 1, a torsion bar extending in the vehicle width direction is provided above the torsion beam, and the foot portions located on the left and right sides of the torsion bar are connected to the bush outer cylinder via the link member. The structure which is rotatably connected to the upper part is disclosed. This technique can increase roll rigidity without changing the shape (cross-sectional characteristics) of the torsion beam by providing a torsion bar that prevents the left and right wheels from moving in the reverse phase separately from the torsion beam.
JP 2005-119363 A

However, in the above prior art, when the vehicle body rolls and the left and right wheels stroke in opposite phases, the suspension steers in a direction that prevents the turning by the reaction force of the torsion bar. For example, assuming a case where the vehicle turns to the right, the left and right trailing arms stroke in the left-right reverse direction around the bush at the front end. At this time, the outer cylinder rotates so that the left side (turning outer ring side) strokes to the bounce side and the left bush twists counterclockwise when viewed from the left side, and the right side (turning inner ring side) strokes to the rebound side. The outer cylinder rotates so that the right bush is twisted clockwise as viewed from the left. As a result, the torsion bar is twisted, the stroke of the left and right wheels to the opposite phase is prevented, and a reaction force due to the twist of the torsion bar is generated. The reaction force acts in the direction of pulling the bush toward the rear side of the vehicle on the left side and acts to push the bush forward of the vehicle on the right side. Then, due to the reaction force of the torsion bar, the suspension as a whole is steered in a direction to receive a turn by receiving a counterclockwise force (a direction opposite to the turning direction).
The present invention has been made paying attention to the above points, and it is an object of the present invention to steer the suspension in the turning direction by a force urging the bush when rolling the vehicle body.

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 rotatable state, and a torsion beam extending in the vehicle width direction to connect the left and right trailing arms, and the bushes are arranged in a nested manner. In the torsion beam type suspension in which an elastic body is interposed between the inner cylinder and the outer cylinder, the outer cylinder is connected to the front end of the trailing arm and the inner cylinder is connected to the vehicle body,
When the left and right wheels are stroked in opposite phases, a bush urging mechanism that urges the outer cylinder of the bush connected to the trailing arm on the wheel bounce side forward in the vehicle front-rear direction along with the bounce is provided. .

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 supported in a freely rotatable state at the rear end portion. A pair of left and right trailing arms, and a torsion beam extending in the vehicle width direction to connect the left and right trailing arms, and each bush includes an inner cylinder and an outer cylinder arranged in a nested manner. In the control method of the torsion beam type suspension comprising an elastic body interposed between the outer cylinder and the trailing arm front end and the inner cylinder connected to the vehicle body,
The outer cylinder of the bush is connected to the trailing arm on the wheel bounce side by the torsional torque of the torsion bar due to the left and right wheels stroking in the opposite phase. Is energized forward in the vehicle front-rear direction along with the bound.

Next, the third aspect of the invention extends to the vehicle body, the left and right wheels, and the vehicle front-rear direction, and the front end portion is pivotally attached to the vehicle body through the bush so as to be swingable in the vertical direction. A pair of left and right trailing arms that are supported in a state where the wheels can rotate, and a torsion beam that extends in the vehicle width direction and connects between the left and right trailing arms. In an automobile in which an elastic body is interposed between the inner cylinder and the outer cylinder arranged in a shape, the outer cylinder is connected to the front end of the trailing arm and the inner cylinder is connected to the vehicle body,
A torsion bar that connects the outer cylinders of the left and right bushes, and a bracket that rotatably supports the torsion bar on the vehicle body,
When the left and right wheels stroke in opposite phases, the torsion bar urges the outer cylinder of the bush connected to the trailing arm on the wheel bounce side forward in the vehicle longitudinal direction along with the bounce.

According to the first invention, during suspension of the vehicle body, the suspension is steered in the same direction as the turn by urging the outer cylinder of the bush on the turning outer wheel side forward in the vehicle longitudinal direction by the bush urging mechanism. Thus, the urging force by the bush urging mechanism acts on the bush as a direction to increase the tire lateral force at the time of rolling, and the turning stability of the vehicle can be improved by the steering.
According to the second aspect of the invention, the outer cylinder of the bush on the turning outer wheel side is urged forward in the vehicle front-rear direction by the torsional torque (reaction force) of the torsion bar due to the left and right wheels stroking in the opposite phase. Will steer in the same direction as the turn. In this way, the reaction force of the torsion bar acts on the bush as a direction to increase the tire lateral force during rolling, and the turning stability of the vehicle can be improved by the steering.

  According to the third aspect of the present invention, the outer cylinder of the bush connected to the trailing arm on the wheel bounce side when the left and right wheels stroke in the opposite phase due to the reaction force of the torsion bar supported by the vehicle body is accompanied by the vehicle front and rear. The suspension is steered in the same direction as the turn by energizing forward in the direction. As described above, the reaction force of the torsion bar supported on the vehicle body via the bracket acts on the bush as a direction to increase the tire lateral force during the roll, and the turning stability of the vehicle can be improved by the steering.

(Embodiment 1)
Next, a first embodiment of the present invention will be described with reference to the drawings.
(Constitution)
FIG. 1 is a diagram showing a vehicle suspension 2 according to this embodiment and a vehicle on which the suspension 2 is mounted. As shown in FIG. 1, the suspension of the present invention is applied to the rear suspension.
As shown in FIG. 1, the suspension 2 has a pair of left and right trailing arms 8 extending in the vehicle front-rear direction, and the front end of the suspension 2 is swingable up and down via a bush 7. 1 is attached to the shaft. 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 the present embodiment, the suspension spring 5 and the shock absorber 6 are provided on the trailing arm 8. In another embodiment, these 5 and 6 are provided at positions adjacent to the torsion beam 4. The effect is the same.

  The bush 7 is configured such that an elastic body is interposed between an inner cylinder and an outer cylinder arranged coaxially on the outer periphery of the inner cylinder. The outer cylinder is fixed to the front end portion of the trailing arm 8, and the inner cylinder is connected to the vehicle body 1 via a mounting bolt. Further, as shown in FIG. 2, the shafts of the left and right bushes 7 are arranged so as to be inclined rearward in the vehicle front-rear direction toward the outer side in the vehicle width direction with respect to the vehicle width direction. As a result, the entire suspension rotates around the virtual rotation center H that is in the vicinity of the intersection of the axial lines of the bush 7 due to the tire lateral force. Thereby, it becomes easy to steer in the turning direction by the tire lateral force.

  The torsion bar 14 is disposed above the torsion beam 4. As shown in FIGS. 3 to 5, the torsion bar 14 extends in the vehicle width direction, and is supported by the vehicle body 1 via the bracket 15 so that the left and right portions can be pivoted. The portion of the bracket 15 that receives the torsion bar 14 is circular so that the torsion bar 14 can be held as freely as possible. If the portion in contact with the bracket 15 and the torsion bar 14 is made of an elastic body, it need not be circular. Further, the cross section of the torsion bar 14 does not have to be a uniform circle, and there is no problem if only the portion held by the bracket 15 is a circle.

  Both end portions of the torsion bar 14 are located outward of the left and right trailing arms 8 in the vehicle width direction, and the upper end portions of the foot portions 13 are integrally connected to the both end portions, respectively. 13 extends downward. The rear end portion of the link member 12 is connected to the lower end portion of the foot portion 13 via a spherical joint so as to be rotatable at least around an axis in the vehicle width direction. The link member 12 extends forward in the vehicle front-rear direction, and its front end is connected to the lower end of the outer cylinder 7a so as to be rotatable at least around an axis in the vehicle width direction. In this embodiment, the outer cylinder bracket 11 protrudes downward from the lower end of the outer cylinder 7a, and the front end of the link member 12 is connected to the lower end of the outer cylinder bracket 11 via a spherical joint. ing.

Here, the rotational center of the spherical joint that connects the outer cylinder bracket 11 and the front end of the link member 12 forms the first connection point Pa, and the rotational center of the spherical joint that connects the foot 13 and the link member 12. Constitutes the second connection point Pb.
In the present embodiment, as shown in FIG. 6, the first connection point Pa is positioned below the straight line L1 passing through the shaft So of the bush 7 and the second connection point Pb as viewed from the vehicle width direction. It is arranged to do.

Further, the second connection point Pb is arranged rearward and downward in the vehicle front-rear direction with respect to the first connection point Pa.
Further, as shown in FIG. 7, in a plan view, a straight line L2 passing through the first connecting point Pa and the second connecting point Pb from the swing center point Po of the bush 7 (substantially central position in the axial direction of the bush 7). The first connection point Pa and the second connection point Pb are arranged so as to be inward in the vehicle width direction.

(Operation)
The suspension having the above configuration operates as follows.
If there is no difference between the strokes of the left and right wheels, the torsion bar 14 is not twisted and does not act. On the other hand, when the left and right wheels stroke in opposite phases, the torsion bar 14 is twisted and the roll rigidity is increased.
At this time, assuming that the vehicle turns right, as shown in FIG. 8, the bush outer cylinder 7a on the bounce side rotates counterclockwise (same direction as the turning direction) in a side view on the wheel bounce side. Due to the dynamic displacement, the bushing outer cylinder 7a on the rebound side is rotationally displaced clockwise (rotating in the direction opposite to the turning direction). At this time, as a result of arranging the first connection point Pa below the straight line passing through the axis So of the bush 7 and the second connection point Pb in a side view, the first connection point Pa on the bounce side. Moves rearward in the vehicle front-rear direction, and accordingly, the second connection point Pb also moves rearward in the vehicle front-rear direction. On the other hand, on the rebound side, the first connection point Pa moves forward in the vehicle front-rear direction, and the second connection point Pb also moves forward in the vehicle front-rear direction. As a result, the torsion bar 14 is twisted and a reaction force F <b> 1 in the opposite direction is applied to the outer cylinder 7 a of each bush 7. Specifically, a reaction force F1 directed forward in the vehicle longitudinal direction is input to the bush outer cylinder 7a on the bounce side, and a reaction force F1 directed in the vehicle longitudinal direction is input to the bush outer cylinder 7a on the rebound side. Is done.

Further, at this time, as a result of the second connection point Pb being arranged rearward and downward in the vehicle front-rear direction with respect to the first connection point Pa, the reaction force F1 on the bounce side is a force obliquely upward with respect to the horizontal direction. The force F2 directed upward is applied to the bushing outer cylinder 7a by the vertical component force thereof, and the reaction force F1 on the rebound side acts as a force directed obliquely downward with respect to the horizontal direction. Due to the directional component force, a downward force F2 acts on the bushing outer cylinder 7a.
As a result of arranging the swing center point Po of the bush 7 (the center position of the bush 7 in the direction of the axis So) inward in the vehicle width direction from the straight line passing through the first connection point Pa and the second connection point Pb. The reaction force F1 is input to the bush 7 as torque in the same direction as the turning direction when viewed from above.

(Function)
And it has the following operation.
When the vehicle turns, the turning outer wheel side bounces, and the turning inner wheel side rebounds, the reaction force F1 of the torsion bar 14 causes the entire suspension to rotate in the same direction as the turning direction as seen from above (see FIG. 2). In the drawing, the force (clockwise in the drawing) is received, and the steering changes toward the turning direction, that is, in the direction of increasing the lateral force of the tire, and the force generated by the rear wheels increases. As a result, it is possible to improve the stability of the vehicle during turning.

Further, at this time, as shown in FIG. 9, by the vertical component force F <b> 2 of the reaction force F <b> 1 from the torsion bar 14, a force acts on the turning outer wheel from the bottom to the top of the vehicle body and the turning inner wheel from the top to the bottom of the vehicle body. . As a result, the entire suspension receives a force that deforms clockwise in FIG. 9 when viewed from the rear of the vehicle, and the outer turning wheel is displaced to the negative camber side and the inner turning wheel is rotated to the positive camber side, generating canvas last. The force generated by the rear wheel is increased. That is, it is possible to move the tire contact point to the outside of the turn and improve the responsiveness at the initial stage of steering.
Further, as shown in FIG. 7, the reaction force F1 is input to the bush 7 as torque about the same direction as the turning direction. As a result, the left and right wheels steer inward of the turning due to the torque, and the tire generates tires. The power can be further increased.

(application)
FIG. 10 is a plan view of the suspension in which the virtual rotation center H is arranged behind the swing center point Po of the bush 7 in the vehicle longitudinal direction as described above due to the lateral force generated by the rear wheels. In this way, the vector from the second connection point Pb to the first connection point Pa is more inclined to the vehicle outer side than the vector from the virtual rotation center H to the swing center point Po of the bush 7 with respect to the vehicle longitudinal direction. The first connection point Pa and the second connection point Pb are set.

  With this arrangement, the reaction force F1 from the torsion bar 14 that occurs when the left and right wheels stroke in opposite phases is the amount parallel to the vector from the virtual rotation center H toward the swing center point Po of the bush 7. Considering the force and the vertical component force F3, the vertical component force F3 is directed toward the outside of the vehicle on the turning outer wheel side and toward the inside of the vehicle on the turning inner wheel side. A force acts in a direction to suppress rotation around the virtual rotation center H.

  In particular, it is possible to improve the rear response in the initial stage of steering. That is, at the initial stage of steering, when the vehicle body 1 rolls before the rear wheels generate force, the torsion bar 14 undergoes torsional deformation and generates a reaction force F1. The generated reaction force F1 is transmitted to the bush 7 to prevent the bush 7 from rotating around the virtual rotation center H (FIG. 11 (a)). In the above-described conventional example, in the initial stage of steering, the tire ground contact point moves inward of the turn by the lateral force generated by the rear wheels (see the left figure in FIG. 12), and a side slip angle is generated in the tire, which is opposite to the turn There is also a problem that a tire lateral force is generated in the direction, reducing the force that the tire should generate for turning, and lowering the response of the rear. On the other hand, in the present embodiment, it is possible to prevent the ground contact point from moving toward the inside of the turn at the initial stage of steering, thereby reducing the tire slip angle in a direction that hinders turning. This has the effect of improving the rear responsiveness. The effect is shown in FIG.

  FIG. 11A is a diagram showing the movement of the torsion beam 4 described above, and FIG. 12 shows this in time series. For comparison with the present embodiment, a response comparison with a torsion beam suspension not equipped with the present invention is shown. In the present invention, when the steering is applied to the step, a force is applied to the bush 7 to suppress the suspension from moving around the virtual rotation center H. Then, the contact point movement amount (inside of turning) 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 1 to the outside of turning is improved. The left figure of FIG. 12 shows the tire side slip angle α when the ground contact point moves to the inside of the turn, and the tire lateral force toward the inside of the turn decreases as the moving speed of the contact point to the inside of the turn increases. There is an effect.

In the steady turning state after the initial stage of steering when the rear wheel generates a large force, the suspension rotates around the virtual rotation center H, so that stability in the steady state can be ensured.
Further, in plan view, the suspension in which the virtual rotation center H is arranged behind the swing center point Po of the bush 7 in the vehicle front-rear direction due to the lateral force generated by the rear wheels is shown in FIG. As shown in FIG. 4, the vector from the virtual rotation center H to the swing center point Po of the bush 7 is more outward than the vector from the second connection point Pb to the first connection point Pa. The first connection point Pa and the second connection point Pb are set so as to be greatly inclined.

  With this arrangement, the reaction force F1 from the torsion bar 14 that occurs when the left and right wheels stroke in opposite phases is the amount parallel to the vector from the virtual rotation center H toward the swing center point Po of the bush 7. Considering the force and the vertical component force F3, the vertical component force F3 is directed toward the inside of the vehicle on the turning outer wheel side and toward the outside of the vehicle on the turning inner wheel side. A force acts in a direction that promotes rotation around the virtual rotation center H.

As a result, a change in the steer angle in the turning direction due to the roll is likely to occur, and the stability in steady turning can be improved.
In the above configuration, the foot 13 extends in a direction perpendicular to the axis of the torsion bar 14. In another embodiment, the foot 13 extends obliquely about the axis of the torsion bar 14 in consideration of interference with other components. The effect is the same.
Here, the connection structure between the torsion bar 14 and the outer cylinder 7a via the link member 12 constitutes a bush urging mechanism.

(effect)
(1) When the vehicle body rolls, the bushing biasing mechanism biases the outer cylinder of the bushing on the turning outer wheel side forward in the vehicle front-rear direction, whereby the suspension steers in the same direction as the turning. Thus, the urging force by the bush urging mechanism acts on the bush as a direction to increase the tire lateral force at the time of rolling, and the turning stability of the vehicle can be improved by the steering.

(2) For example, the bush urging mechanism includes a torsion bar that extends in the vehicle width direction and is rotatably supported by the vehicle body, and is integrally provided on the left and right sides of the torsion bar and intersects with the axis of the torsion bar. Left and right foot portions extending in the direction, and link members that connect the foot portions and the outer cylinder and are rotatably connected to the foot portions and the outer cylinder, respectively, and a connecting point of the link member to the outer cylinder When the first connection point and the connection point to the foot of the link member are defined as the second connection point, the first connection point is below the straight line passing through the bush shaft and the second connection point in a side view. It can be realized by arranging.

(3) By arranging the second connection point behind and below the first connection point in the vehicle front-rear direction, a force in the vertical direction acts on the bush during rolling, and the tire ground contact point toward the turning outer wheel side It is possible to improve the responsiveness at the initial stage of steering.
(4) The center of swing of the bush is positioned inward in the vehicle width direction from the straight line passing through the first and second connection points in plan view. In addition, the moment in the yaw direction acts, and the change in steering toward the toe-in side during the roll can be increased.

(5) The first connection point and the second connection point in a plan view when the virtual rotation center of the suspension with respect to the lateral force is arranged behind the swing center point of the bush in the vehicle front-rear direction. The line segment connecting the imaginary rotation center of the suspension and the pivot center point of the bush is tilted outward in the vehicle width direction with respect to the vehicle longitudinal direction. The force acts in the opposite direction to the deformation of the bush due to the lateral force, which increases the apparent bush shaft rigidity, increases the contact point rigidity, and improves the rear response at the initial stage of steering.

(6) The first connection point and the second connection point in a plan view when the virtual rotation center of the suspension with respect to the lateral force is arranged behind the swing center point of the bush. The line connecting the suspension and the center of rotation of the suspension with respect to the vehicle longitudinal direction is tilted inward in the vehicle width direction relative to the vehicle longitudinal direction relative to the line segment connecting the virtual rotation center of the suspension and the swing center point of the bush. Force acts in a direction that facilitates rotation around the virtual rotation center H. As a result, a change in the steer angle in the turning direction due to the roll is likely to occur, and the stability in steady turning can be improved.

(7) By urging the outer cylinder of the bush connected to the trailing arm on the wheel bounce side forward with the bounce in the vehicle front-rear direction by a torsion bar that twists when the left and right wheels stroke in opposite phases, It acts on the bush as a direction to increase the tire lateral force during rolling, and the turning stability of the vehicle can be improved by the steering.
(8) By urging the outer cylinder of the bush on the turning outer wheel side forward in the vehicle front-rear direction by the torsional torque (reaction force) of the torsion bar caused by the left and right wheels moving in opposite phases, the suspension is the same as turning. Steer changes in direction. In this way, the reaction force of the torsion bar acts on the bush as a direction to increase the tire lateral force during rolling, and the turning stability of the vehicle can be improved by the steering.

(9) When the left and right wheels stroke in the opposite phase due to the reaction force of the torsion bar supported by the vehicle body, the outer cylinder of the bush connected to the trailing arm on the wheel bounce side is urged forward in the vehicle longitudinal direction along with the bounce. The suspension steers in the same direction as the turn. In this way, the reaction force of the torsion bar supported by the vehicle body via the bracket acts on the bush as a direction to increase the tire lateral force during rolling, and the turning stability of the vehicle can be improved by the steering.

(Second Embodiment)
Next, a second embodiment will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected and demonstrated about the member similar to the said 1st Embodiment.
(Constitution)
The basic configuration of this embodiment is the same as that of the first embodiment, but the arrangement of the torsion bars 14 is different. That is, as shown in FIG. 14, the torsion bar 14 is arranged in front of the bush 7 in the vehicle front-rear direction, so that the second connection point Pb is arranged in front of the vehicle front-rear direction than the first connection point Pa. .
Note that either the bush 7 or the torsion bar 14 may be disposed above. As an example, the torsion bar 14 is arranged higher than the bush 7. This is advantageous when considering interference with the ground.

Also in this embodiment, when viewed from the vehicle width direction, the first connection point Pa is arranged at a position located below a straight line connecting the axis So of the bush 7 and the second connection point Pb.
In the second embodiment, the second connection point Pb is disposed forward and upward in the vehicle front-rear direction with respect to the first connection point Pa.
In accordance with the arrangement of the first connection point Pa below the second connection point Pb, the distance from the axis So of the bush 7 to the first connection point Pa (moment arm) in the side view is expressed by the torsion bar. A layout longer than the distance from the 14 axes to the second connection point Pb is adopted.
Other configurations are the same as those in the first embodiment.

(Operation)
In the side view on the wheel bounce side, the bush outer cylinder 7a on the bounce side is rotationally displaced counterclockwise, and the bush outer cylinder 7a on the rebound side is rotationally displaced clockwise. At this time, as a result of arranging the first connection point Pa at a position located below a straight line connecting the axis So of the bush 7 and the second connection point Pb in a side view, the first connection point Pa is formed on the bounce side. The point Pa moves rearward in the vehicle front-rear direction, and the second connection point Pb moves rearward in the vehicle front-rear direction accordingly. On the other hand, on the rebound side, the first connection point Pa moves forward in the vehicle front-rear direction, and the second connection point Pb also moves forward in the vehicle front-rear direction. As a result, the torsion bar 14 is twisted and a reaction force F <b> 1 in the opposite direction is applied to the outer cylinder 7 a of each bush 7. Specifically, a reaction force F1 directed forward in the vehicle longitudinal direction is input to the bush outer cylinder 7a on the bounce side, and a reaction force F1 directed in the vehicle longitudinal direction is input to the bush outer cylinder 7a on the rebound side. Is done.

Further, at this time, as a result of the second connection point Pb being arranged forward and upward in the vehicle front-rear direction with respect to the first connection point Pa, the reaction force F1 on the bounce side is a force that is obliquely upward with respect to the horizontal direction. The upward force acts on the bushing outer cylinder 7a by the vertical component force, and the reaction force F1 on the rebound side acts as a force obliquely downward with respect to the horizontal direction. Due to the component force, a downward force acts on the bushing outer cylinder 7a.
As a result of arranging the swing center point Po of the bush 7 (the center position of the bush 7 in the direction of the axis So) inward in the vehicle width direction from the straight line passing through the first connection point Pa and the second connection point Pb. The reaction force F1 is input to the bush 7 as torque in the same direction as the turning direction when viewed from above.

(Function)
As a result of the torsion beam 4 and the left and right trailing arms 8 being less likely to interfere with the torsion bar 14 and the foot 13 during the suspension stroke, the degree of freedom in the layout of the components is increased.
By making the moment arm on the bush 7 side longer than the moment arm on the torsion bar 14 side, the diameter of the torsion bar 14 can be reduced.

  As shown in FIG. 14, in a side view, the rotation angle of the bush 7 is θo, the rotation angle of the torsion bar 14 is θa, the distance from the bushing shaft So to the first connection point Pa is Loa, and the torsion is from the second connection point Pb. Assuming that the distance to the center axis Sc of the bar is Lbc, θa≈ (Loa / Lbc) × θo can be approximated when the angle θo changes about the axis So of the bush due to the vertical displacement of the tire. Assuming that the torsional rigidity of the torsion bar 14 is Ks, the moment generated by the torsion bar 14 is 2 × (Loa / Lbc) × θo × Ks when the left and right wheels stroke in opposite phases. That is, when the same moment is to be generated, Ks can be reduced by increasing (Loa / Lbc). To reduce Ks, it is possible to reduce the diameter of the stabilizer 14, and the diameter can be reduced. And reducing the diameter leads to weight reduction of the vehicle.

(application)
FIG. 15 shows the second embodiment and other configuration examples. That is, this is an example in which the second connection point Pb is arranged above the torsion bar 14. In this case, the above-described effects can be achieved. It is not necessary to arrange the torsion bar 14 lower than the bush 7.

(effect)
(1) By disposing the second connection point forward and rearward in the vehicle front-rear direction with respect to the first connection point, a force in the vertical direction acts on the bush during rolling, and the tire ground contact point is on the turning outer wheel side. It is possible to improve the responsiveness at the initial stage of steering. Furthermore, interference between the trailing arm and the torsion bar can be avoided during the suspension stroke, and the layout of the suspension is improved.
(2) When viewed from the side, the distance from the bushing axis to the first coupling point is longer than the distance from the central axis of the torsion bar to the second coupling point, thereby increasing the twist ratio of the torsion bar to the stroke. Thus, the urging force against the bush due to the reaction force of the torsion bar can be increased. This leads to downsizing of the torsion bar.

(Third embodiment)
Next, a third embodiment will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected and demonstrated to the member similar to the said embodiment.
(Constitution)
The basic configuration of the third embodiment is the same as that of the first embodiment, except that the torsion bar 14 is disposed below the trailing arm 8 as shown in FIG.
Other configurations are the same as those in the first embodiment.
(Function and effect)
The torsion bar 14 can be disposed on the vehicle body 1 without interfering with the fuel tank or the like which is easily disposed near the front of the bush 7 in the vehicle.
Other functions and effects are the same as in the above embodiment.

(Fourth embodiment)
Next, embodiments of the present invention will be described with reference to the drawings. In addition, about the same location as the said embodiment, the same code | symbol is attached | subjected and demonstrated.
(Constitution)
In the present embodiment, as shown in FIG. 17, the shaft So of each bush 7 is arranged so as to be inclined so as to go forward in the vehicle front-rear direction as it goes from the inner side to the outer side in the vehicle width direction. In this example, the rotation center H is arranged in front of the bush 7 in the front-rear direction of the vehicle.
Other basic configurations are the same as those of the above-described embodiments. However, as shown in FIG. 17, the first configuration with respect to a straight line passing through the swing center point Po of the bush 7 and the virtual rotation center H in plan view. The straight line connecting the connection point Pa and the second connection point Pb is angled so that the front side in the vehicle front-rear direction is outside the vehicle with respect to the vehicle front-rear direction. Two connection points Pb are arranged.

(Operation / Action)
At the time of turning, the suspension tends to move laterally around the virtual rotation center H in front of the bush 7.
At this time, the reaction force F1 from the torsion bar 14 generated when the left and right wheels stroke in opposite phases is a component force parallel to the vector from the virtual rotation center H to the swing center point Po of the bush 7 and perpendicular thereto. When broken down into the component force F3, the vertical component force F3 is directed toward the outside of the vehicle on the turning outer wheel side and toward the inside of the vehicle on the turning inner wheel side. Force acts in the direction to suppress the rotation. That is, it becomes possible to prevent the toe angle of the rear wheels from being generated toward the outer side of the turn with respect to the lateral force generated by the rear wheels, and as a result, it is possible to prevent a decrease in the stability of the vehicle during the turn. .

(effect)
(1) The virtual rotation center of the suspension with respect to the lateral force is located in front of the bushing center point in the vehicle front-rear direction, and the line segment connecting the first connection point and the second connection point in plan view is The front of the vehicle in the longitudinal direction of the vehicle is tilted outward in the vehicle width direction with respect to the longitudinal direction of the vehicle with respect to the line segment connecting the virtual center of rotation and the swing center point of the bush. It is possible to prevent the toe angle of the rear wheel from being generated toward the turning outer wheel with respect to the lateral force that is arranged forward in the front-rear direction and is generated by the rear wheel. As a result, it is possible to prevent a decrease in vehicle stability during turning.

It is a figure which shows the vehicle body and suspension which concern on embodiment based on this invention. It is a typical top view showing arrangement of a bush concerning a 1st embodiment based on the present invention. It is a fragmentary perspective view which shows the suspension structure which concerns on 1st Embodiment based on this invention. It is a side view which shows arrangement | positioning of the suspension which concerns on 1st Embodiment based on this invention. It is a schematic diagram which shows arrangement | positioning of the torsion bar etc. which concern on 1st Embodiment based on this invention. It is a side view which shows the relationship between a bush axis | shaft, a 1st connection point, and a 2nd connection point. It is a typical top view explaining the effect of the suspension concerning a 1st embodiment based on the present invention. It is a figure explaining the effect of the suspension concerning a 1st embodiment based on the present invention. It is the schematic diagram seen from the vehicle rear explaining the effect of the suspension which concerns on 1st Embodiment based on this invention. It is a figure explaining the effect of the suspension concerning a 1st embodiment based on the present invention. It is a figure which prints the effect of the suspension which concerns on 1st Embodiment based on this invention. It is a figure which prints the effect of the suspension which concerns on 1st Embodiment based on this invention. It is a figure which prints the effect of the suspension which concerns on 1st Embodiment based on this invention. It is a side view which shows the suspension which concerns on 2nd Embodiment based on this invention. It is a side view which shows the suspension of another example which concerns on 2nd Embodiment based on this invention. It is a side view which shows the suspension which concerns on 3rd Embodiment based on this invention. It is a side view which shows the suspension which concerns on 4th Embodiment based on this invention. It is a figure explaining a prior art example.

Explanation of symbols

2 Suspension 3 Wheel 4 Torsion beam 7 Bush 8 Trailing arm 11 Outer cylinder bracket 12 Link member 13 Foot 14 Torsion bar Pa First connection point Pb Second connection point Po Bushing center point So Bushing shaft Sc Torsion bar Center axis H Virtual rotation center

Claims (12)

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 to connect the left and right trailing arms, and each bush has an elastic body between an inner cylinder and an outer cylinder arranged in a nested manner. In the torsion beam suspension in which the outer cylinder is connected to the trailing arm front end and the inner cylinder is connected to the vehicle body,
A torsion beam suspension comprising a bush urging mechanism for urging the outer cylinder of the bush connected to a trailing arm on the wheel bounce side when the left and right wheels stroke in opposite phases, along with the bound . 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 to connect the left and right trailing arms, and each bush has an elastic body between an inner cylinder and an outer cylinder arranged in a nested manner. In the torsion beam suspension in which the outer cylinder is connected to the trailing arm front end and the inner cylinder is connected to the vehicle body,
A torsion bar that extends in the vehicle width direction and is rotatably supported by the vehicle body, left and right foot portions that are integrally provided on the left and right sides of the torsion bar and extend in a direction intersecting the axis of the torsion bar, and the foot portions And a link member that connects the outer cylinder and rotatably couples to the foot and the outer cylinder,
When the connection point to the outer cylinder of the link member is defined as a first connection point and the connection point to the foot of the link member is defined as a second connection point,
A torsion beam suspension, characterized in that the first connection point is disposed below a straight line passing through the bush shaft and the second connection point in a side view.   The torsion beam suspension according to claim 2, wherein the second connection point is disposed rearward and downward in the vehicle front-rear direction with respect to the first connection point.   The torsion beam suspension according to claim 2, wherein the second connection point is disposed forward and rearward of the vehicle front-rear direction with respect to the first connection point.   The distance from the axis | shaft of a bush to a 1st connection point is longer than the distance from the center axis | shaft of a torsion bar to a 2nd connection point in a side view, The claim 1 characterized by the above-mentioned. The torsion beam suspension described.   6. The plane according to claim 2, wherein the swing center point of the bush is located inward in the vehicle width direction from a straight line passing through the first connection point and the second connection point in plan view. The torsion beam type suspension described in item 1. The virtual rotation center of the suspension with respect to the lateral force is located behind the bushing center point in the vehicle longitudinal direction,
In plan view, the line connecting the first connection point and the second connection point is more forward in the vehicle front-rear direction than the line connecting the virtual rotation center of the suspension and the swing center point of the bush. The torsion beam suspension according to any one of claims 2 to 6, wherein the suspension is inclined outward in the width direction. The virtual rotation center of the suspension with respect to the lateral force is located behind the bushing center point in the vehicle longitudinal direction,
In plan view, the line connecting the first connection point and the second connection point is more forward in the vehicle front-rear direction than the line connecting the virtual rotation center of the suspension and the swing center point of the bush. The torsion beam suspension according to any one of claims 2 to 6, wherein the suspension is inclined inward in the width direction. The virtual rotation center of the suspension with respect to lateral force is located in front of the bushing center point in the vehicle longitudinal direction,
In plan view, the line connecting the first connection point and the second connection point is more forward in the vehicle front-rear direction than the line connecting the virtual rotation center of the suspension and the swing center point of the bush. The torsion beam suspension according to any one of claims 2 to 6, wherein the suspension is inclined outward in the width direction. 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 to connect the left and right trailing arms, and each bush has an elastic body between an inner cylinder and an outer cylinder arranged in a nested manner. In the torsion beam suspension in which the outer cylinder is connected to the trailing arm front end and the inner cylinder is connected to the vehicle body,
A torsion beam that urges the outer cylinder of the bush connected to the trailing arm on the wheel bounce side forward in the vehicle front-rear direction along with the bounce by a torsion bar that twists when the left and right wheels stroke in opposite phases. Suspension. 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 to connect the left and right trailing arms, and each bush has an elastic body between an inner cylinder and an outer cylinder arranged in a nested manner. In the control method of the torsion beam type suspension in which the outer cylinder is connected to the front end of the trailing arm and the inner cylinder is connected to the vehicle body.
The outer cylinder of the bush is connected to the trailing arm on the wheel bounce side by the torsional torque of the torsion bar due to the left and right wheels stroking in the opposite phase. The torsion beam suspension control method is characterized by urging the vehicle forward in the vehicle front-rear direction along with the bound. The vehicle body, the left and right wheels, and the vehicle extend in the front-rear direction, and the front end portion is pivotally attached to the vehicle body so as to be swingable in the vertical direction via the bush, and the wheel is rotatable at the rear end portion. A pair of left and right trailing arms to be supported, and a torsion beam extending in the vehicle width direction to connect the left and right trailing arms, and each bush includes an inner cylinder and an outer cylinder arranged in a nested manner In the automobile in which the outer cylinder is connected to the front end of the trailing arm and the inner cylinder is connected to the vehicle body.
A torsion bar that connects the outer cylinders of the left and right bushes, and a bracket that rotatably supports the torsion bar on the vehicle body,
An automobile characterized in that, when the left and right wheels stroke in opposite phases, the torsion bar urges the outer cylinder of the bush connected to the trailing arm on the wheel bounce side forward in the vehicle front-rear direction along with the bounce.

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