JP2006027509A - Independent wheel suspension system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an independent wheel suspension system capable of enhancing the steering stability by providing the characteristic of the under-steer in a turning mode with rear wheels tow-in during the bound even in a structure in which a lateral link is omitted, and an axle member and a vehicle body are connected to each other via a shock absorber and a leaf spring. <P>SOLUTION: In the independent wheel suspension system, an axle member 1 to rotatably support a wheel W is connected to a vehicle body via a shock absorber 2 extending in the vertical direction and a leaf spring 3 extending in the longitudinal direction of a vehicle. The shock absorber 2 is of the type in which a rod 5 is protruded from both ends of a cylinder 4, both ends of the rod 5 are connected to a vehicle body, the cylinder 4 is connected to the axle member 1, the leaf spring 3 is connected to the vehicle body, the leaf spring 3 is inclined in the negative camber direction, and the leaf spring 3 is connected to the axle member 1 in a rocking manner via a pivoting means 8 with the vertical direction as its axis. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an independent suspension device that individually suspends wheels, and more particularly to a wheel independent suspension device that can save space under the vehicle floor and can improve the handling stability of the vehicle.

  Conventionally, as described in Patent Document 1, for example, as an independent wheel suspension apparatus, an axle member that rotatably supports a wheel is moved in a toe direction by a trailing member (a swing arm in Patent Document 1) that extends in the vehicle front-rear direction. The vehicle is restrained and restrained in the vehicle width direction by one lateral link (upper link and lower link in Patent Document 1) that extends to the bottom of the vehicle body in the vehicle width direction so that it can bounce and rebound in the vehicle vertical direction. A supported configuration has been proposed.

  However, in the conventional independent wheel suspension system represented by the above, the structure in which the axle member is restrained in the vehicle width direction using a lateral link that extends from the axle member inward in the vehicle width direction to the bottom of the vehicle body floor. Therefore, when the lateral link that extends inward in the vehicle width direction to the bottom of the vehicle body bounces or rebounds the axle member (wheel), a space for swinging up and down around the vehicle side attachment point is used as the pivot point. It is necessary to secure it. As a result, there is a problem that the vehicle interior space is sacrificed by the amount of protrusion to the vehicle interior under the vehicle body floor, making it difficult to reduce the floor and making it difficult to secure a spacious passenger space.

In order to solve this problem, as shown in FIG. 7, a structure in which a lateral link is eliminated and an axle member 51 is directly connected to a vehicle body by a shock absorber 52 and a leaf spring 53 has been proposed. However, depending on these structures, the axle member 51 moves along the center axis of the shock absorber 52 in a state where the movement in the toe direction is constrained by the leaf spring 53. When rolling, the rear wheel outside the turn cannot be toe-in (this is called roll steer), and there is a new problem that the steering stability performance cannot be improved by giving an understeer characteristic when turning. Occurred.
JP-A-10-0776826

  An object of the present invention is to solve the above-mentioned problems of the prior art, and the object of the present invention is to eliminate the lateral link and connect the axle member via the shock absorber and the leaf spring. An object of the present invention is to provide a wheel independent suspension device that can enhance steering stability by using a rear wheel as a toe-in when bouncing and giving an understeer characteristic during cornering even in a structure in which a vehicle body is connected.

The wheel independent suspension device according to the present invention is configured such that an axle member that rotatably supports a wheel is connected to a vehicle body via a shock absorber that extends in the vertical direction and a leaf spring that extends in the vehicle front-rear direction. A wheel independent suspension device,
The shock absorber is a type in which the rod protrudes from both ends of a cylinder, and both ends of the rod are connected to the vehicle body, the cylinder is connected to the axle member, and the leaf spring is connected to the vehicle body,
The leaf spring is inclined in the negative camber direction, and the leaf spring is swingably connected to the axle member via a pivoting means having a vertical axis as a central axis.

  In this way, by tilting the leaf spring in the negative camber direction, the axle member side of the leaf spring can be moved inward in the vehicle width direction when bound, and outward in the vehicle width direction when rebounding. Due to such movement of the leaf spring on the axle member side, at the time of bouncing, the pivot means side of the axle member is rotated relative to the center axis of the cylinder and rod of the shock absorber, and the leaf spring and the axle member On the basis of the swing, it can be moved inward in the vehicle width direction, and at the time of rebound, the pivot means side of the axle member can be moved outward in the vehicle width direction. As a result, based on the roll of the vehicle body at the time of turning, the rear wheel outside the turn is made toe-in, and the rear wheel inside the turn is made toe-out, thereby giving an understeer tendency and improving steering stability.

Embodiments of the present invention will be described below in detail based on the drawings.
FIG. 1 is a schematic diagram showing a main part of a wheel independent suspension device according to an embodiment of the present invention. FIG. 1 (a) shows what is seen from the side of the vehicle, FIG. 1 (b) shows what is seen from the front of the vehicle, and FIG. 1 (c) shows what is seen from below the vehicle.

  As shown in FIG. 1, a wheel independent suspension device according to an embodiment of the present invention includes an axle member 1 that rotatably supports a wheel W, a shock absorber 2 that extends in the vertical direction, and a vehicle longitudinal direction. The shock absorber 2 is connected to the vehicle body B via the existing leaf spring 3, and the rod 5 is projected from both ends of the cylinder 4, and both ends of the rod 5 are bracketed. The cylinder 4 is connected to the axle member 1 via a bracket 6 and the leaf spring 3 is allowed to move in the vehicle front-rear direction in response to bounce and rebound. The leaf spring 3 and the shackle 7 are connected in the negative camber direction (vehicle width) by connecting to the vehicle body B via the shackle 7 which is a connecting means. The bush 8 as a pivoting means having the up and down direction C1 as the central axis with respect to the axle member 1 by inclining the inner side in the downward direction and the outer side in the vehicle width direction up (corresponding to claim 3) ), And a bracket 9 so as to be swingably connected. (Equivalent to Claim 1) At this time, the central axis of the shock absorber 2 and the central axis C1 of the bush 8 are provided so as to be parallel when viewed from the rear of the vehicle.

  The cylinder 4 and the rod 5 of the shock absorber 2 can be relatively displaced in the cylinder axis direction and around the cylinder axis, but the relative displacements in the other four directions are constrained to each other.

As shown in FIG. 1A, such a shock absorber 2 is provided so that the relative displacement direction of the cylinder 4 and the rod 5 is the vertical direction. Here, in order to obtain an anti-dive property that alleviates a nose dive phenomenon (a phenomenon in which the front of the vehicle body sinks) during vehicle braking, the shock absorber 2 is tilted backward so that its upper end is positioned behind the lower end of the vehicle. Provide.
In this posture, as shown in FIG. 1B, the shock absorber 1 connects the lower end of the rod 5 protruding from the lower end of the cylinder 4 to the vehicle body B via the bracket 10, and the rod 5 protruding from the upper end of the cylinder 4. The upper end is connected to the vehicle body B via the bracket 11 and is restrained in the vehicle longitudinal direction, the vertical direction, and the vehicle width direction.

FIG. 2 is a schematic diagram showing the movement of the leaf spring and the axle member of the wheel independent suspension shown in FIG.
2 (a) is a side view, FIG. 2 (b) is a front view, FIG. 2 (c) is a normal view, and FIG. 2 (d) is a bounce. FIG. 2 (e) shows a view from below of the hour, and FIG. 2 (e) shows a view from below of the rebound.

  As shown in FIG. 2 (b), when the wheel W and the axle member 1 bounce, the axle member 1 side of the leaf spring 3 moves inward in the vehicle width direction. Based on the relative rotation of the shock absorber 2 around the central axis of the cylinder 4 and the rod 5 and the swinging of the leaf spring 3 and the axle member 1, It can be moved inward in the vehicle width direction. In particular, as compared to a bearing described later, the force in the direction of galling acting on each of the relative rotation center of the shock absorber 2 and the swing center of the bush 8 when they are not parallel when viewed from the side of the vehicle is absorbed. can do.

As shown in FIG. 2 (b), when the wheel W and the axle member 1 rebound, the axle member 1 side of the leaf spring 3 moves outward in the vehicle width direction. The bush 8 side can be moved outward in the vehicle width direction based on the relative rotation around the central axis of the cylinder 4 and rod 5 of the shock absorber 2 and the swinging of the leaf spring 3 and the axle member 1. it can.
Thereby, the wheel W and the axle member 1 become toe-in when bound and toe-out when rebound, and the steering characteristics can be improved by setting the vehicle characteristics as understeer during turning.

FIG. 3 is a schematic view showing a main part of a wheel independent suspension device according to another embodiment of the present invention. FIG. 3A shows what is seen from the side of the vehicle, FIG. 3B shows what is seen from the front of the vehicle, and FIG. 3C shows what is seen from below the vehicle.
The wheel independent suspension shown in FIG. 3 is such that the central axis C1 of the bush 8 serving as a pivot means is parallel to the central axis of the shock absorber 2. (Corresponding to claim 2) This prevents a force in the direction of the bushing 8 and the shock absorber 2 from acting on the bush 8 and the shock absorber 2 at the time of bounding and rebounding, and makes the axle member 1 bounce and rebound movement smoother. can do.
Since other structures and operational effects are the same as those of the wheel independent suspension shown in FIG.

FIG. 4 is a schematic view showing a main part of a wheel independent suspension device according to another embodiment of the present invention. 4A shows what is seen from the side of the vehicle, FIG. 4B shows what is seen from the front of the vehicle, and FIG. 4C shows what is seen from below the vehicle.
The wheel independent suspension shown in FIG. 4 uses a bearing 12 as a pivot means instead of a bush. (Equivalent to claim 4)
This also realizes toe-in at the bounce and toe-out at the rebound as in the wheel independent suspension shown in FIG. 1, and can improve the steering stability as a tendency of understeer during turning. Furthermore, by using a bearing instead of the bush, the rigidity in the direction perpendicular to the central axis of the pivoting means can be increased, so that the rigidity of the independent wheel suspension and thus the entire vehicle can be increased.
Since other structures and operational effects are the same as those of the wheel independent suspension shown in FIG.

FIG. 5 is a schematic view showing a main part of a wheel independent suspension device according to another embodiment of the present invention. 5 (a) shows what is seen from the front of the vehicle, FIG. 5 (b) shows what is seen from the side of the vehicle, FIG. 5 (c) shows what is seen from below the vehicle, and FIG. It is a figure which shows a leaf spring single-piece | unit.
As shown in FIG. 5 (d), the wheel independent suspension device shown in FIG. 5 has a shape in which the axle member mounting side of the leaf spring is pre-twisted in the positive camber direction with respect to the vehicle body mounting side. As shown in (b), the axle member mounting side of the leaf spring is twisted in the negative camber direction with respect to the vehicle body mounting side so that the leaf spring becomes flat when assembled. (Equivalent to claim 5)

According to this, as shown in FIG. 5A, the moment N applied to the shock absorber 2 by the input F of the ground contact point position of the wheel W is generated by the torsional reaction force of the leaf spring 3 twisted in advance. By canceling with the moment M, the friction in the shock absorber 2 generated from the moment N can be suppressed, and the riding comfort of the vehicle can be enhanced.
Since other structures and operational effects are the same as those of the wheel independent suspension shown in FIG.

FIG. 6 is a schematic view showing a main part of a wheel independent suspension device according to another embodiment of the present invention. 6A shows what is seen from the front of the vehicle, FIG. 6B shows what is seen from the side of the vehicle, and FIG. 6C shows what is seen from below the vehicle.
As shown in FIG. 6B, the wheel independent suspension device shown in FIG. 6 is obtained by twisting the axle member mounting side of a flat leaf spring in the negative camber direction with respect to the vehicle body mounting side during assembly. . (Equivalent to claim 5)

As a result, as shown in FIG. 6A, the moment N applied to the shock absorber 2 by the input F of the ground contact point position of the wheel W is changed to the moment generated by the torsional reaction force of the leaf spring 3 that has been twisted in advance. By canceling with M, the friction in the shock absorber 2 generated from the moment N can be suppressed, and the riding comfort of the vehicle can be enhanced.
Since other structures and operational effects are the same as those of the wheel independent suspension shown in FIG.
In addition, this invention is not limited only to the said embodiment, Many deformation | transformation or a change is possible.

  The present invention is effective when applied to a wheel independent suspension device that can increase the interior space of the vehicle and improve the steering stability.

It is a schematic diagram which shows the principal part of the wheel independent suspension which becomes one Example of this invention. It is a schematic diagram which shows the bounce and rebound motion of the leaf spring and axle member of the wheel independent suspension apparatus which become one Example of this invention shown in FIG. It is a schematic diagram which shows the principal part of the wheel independent suspension apparatus which becomes another Example of this invention. It is a schematic diagram which shows the principal part of the wheel independent suspension apparatus which becomes another Example of this invention. It is a schematic diagram which shows the principal part of the wheel independent suspension apparatus which becomes another Example of this invention. It is a schematic diagram which shows the principal part of the wheel independent suspension apparatus which becomes another Example of this invention. It is a schematic diagram which shows the principal part of the conventional wheel independent suspension apparatus.

Explanation of symbols

1 Axle member 2 Shock absorber 3 Leaf spring 4 Cylinder 5 Rod 6 Bracket 7 Shackle 8 Bush 9 Bracket 9 Bracket 10 Bracket 11 Bracket 12 Bearing

Claims (5)

A wheel independent suspension device in which an axle member that rotatably supports a wheel is connected to a vehicle body via a shock absorber that extends in a vertical direction and a leaf spring that extends in a vehicle longitudinal direction,
The shock absorber is a type in which the rod protrudes from both ends of a cylinder, and both ends of the rod are connected to the vehicle body, the cylinder is connected to the axle member, and the leaf spring is connected,
A wheel independent suspension device in which the leaf spring is tilted in a negative camber direction and is pivotally connected to an axle member via a pivoting means having a vertical axis as a central axis.   The wheel independent suspension device according to claim 1, wherein a central axis of the pivot support means is parallel to a central axis of the shock absorber.   The wheel independent suspension device according to claim 1 or 2, wherein the pivot support means is a bush.   The wheel independent suspension system according to claim 1 or 2, wherein the pivot means is a bearing.   The wheel independent suspension device according to any one of claims 1 to 4, wherein an axle member attachment side of the leaf spring is twisted in a negative camber direction with respect to a vehicle body attachment side.

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