JPS6143204B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rear suspension installed on a vehicle, and more particularly to a rear suspension that changes the toe-in of a wheel in response to lateral force.

Generally, when a vehicle is equipped with a rear suspension equipped with a vehicle, when the vehicle turns, a force (lateral force) toward the center of the turn acts on the left and right wheels, especially the wheels on the outside of the center of the turn. On the other hand, it is known that it is preferable to change the toe-in so that the wheels face inward with respect to the driving direction in order to prevent oversteering and improve driving stability.

Conventionally, as a rear suspension that changes the toe-in of the wheel in response to such lateral force, the rear suspension arm, which has one end rotatably supported on the vehicle body, and the wheel hub, which rotatably supports the wheel, have a A float connection is made at least at two points in the front and back, and this connection structure is connected with a spring at the front and a pin at the rear (West German Patent No.
2158931), the characteristics of the front spring are gradually weakened according to the lateral force (West German Patent No. 2355954), or the front and rear springs are connected with rubber bushings, and the stiffness of the front rubber bushings is reduced. One that is softer than the rubber bushing on the side (Tokukosho)
No. 52-37649) has been proposed.

However, in all of the above-mentioned conventional devices, the toe-in effect against the lateral force cannot be effectively exerted because the lateral force is simply displaced in the toe-in direction of the spring or the rubber bushing. Moreover, the wheel acting force other than the lateral force,
For example, toe-in effects cannot be expected with respect to brake force, engine braking force, and engine driving force.

In view of this, the present invention provides a ball joint and two elastic bushes to connect the rear suspension component such as the rear suspension arm and the wheel support member that rotatably supports the wheel. The main objective is to enable the wheel to effectively change toe-in in response to lateral force by float coupling and appropriately setting the position of each coupling portion with respect to the center of the wheel.

Furthermore, another object of the present invention is to enable the toe-in effect to be exerted on acting forces other than lateral force, that is, braking force, engine braking force, and engine driving force.

In order to achieve this object, the configuration of the present invention includes a rear suspension component whose one end is rotatably supported on the vehicle body, a wheel support member rotatably supports a wheel, and a combination of the wheel support member and the rear suspension component. a ball joint that connects the members so as to be able to swing around one point; a first elastic bushing that connects the wheel support member and the rear suspension component; and the wheel support member and the rear suspension. a second elastic body bush that connects the pension component with the ball joint; The bushing is located in the first quadrant of the above coordinates, and the second elastic bushing is located in the second quadrant, so that in response to lateral force, the mounting surface including the three connection points described above rotates around the ball joint. The toe-in of the wheel can be changed by changing the rotational displacement of the mounting surface, and the toe-in can also be changed with respect to other braking force, engine braking force, and engine driving force by rotational displacement of the mounting surface.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 shows a first embodiment in which the present invention is applied to a semi-trailing type rear suspension. Reference numeral 1 denotes a semi-trailing arm as a component of the rear suspension extending substantially in the longitudinal direction of the vehicle body; One end of the trailing arm 1, that is, a forked front end, is rotatably supported by a sub-frame 2, which is a vehicle body component and is disposed in the left-right direction of the vehicle body. Reference numeral 3 denotes a wheel hub as a wheel support member that rotatably supports the wheel 4. The wheel 4 is connected to the other end of a drive shaft 6 whose one end is connected to a differential 5. In addition, in FIG. 1, 7 is a shock absorber, 8 is a coil spring, and 9 is a stabilizer.

Between the wheel hub 3 and the semi-trailing arm 1 is a ball joint P that is swingable about one point, as shown in FIGS. 4 to 6, which will be described later. The first and second elastic bushings R 1 and R 2 are float-coupled by two first and second elastic bushings R ₁ and R ₂ made of rubber bushings or the like having a fixed axis. The arrangement structure of the ball joint P and the first and second elastic bushes R ₁ and R ₂ will be described later.

Further, FIG. 2 shows a second embodiment in which the present invention is applied to a strut-type rear suspension, in which reference numeral 10 denotes a strut hub as a rear suspension component that supports struts 11, and the strut hub 10 extends in the left-right direction of the vehicle body. Through two-link suspension arms 12, 12 extending to
It is rotatably supported by sub-frames 13 and 14, which serve as vehicle body structural members, which are arranged front and rear in the left-right direction of the vehicle body. The strut hub 10 and wheel 1
Similarly to the first embodiment, the ball joint P and the first and second elastic bushes R ₁ and R ₂ are connected to the wheel hub 16 as a wheel support member that rotatably supports the wheel. are connected together. In FIG. 2, 17 is a stabilizer, 18 is a differential, and 19 is a drive shaft.

Furthermore, FIG. 3 shows a third embodiment in which the present invention is applied to a Deion type rear suspension,
is a rear axle tube as a rear suspension component extending in the left-right direction of the vehicle body and into which a rear axle provided separately from the drive shaft 21 is inserted; It is rotatably supported by the vehicle body via tension rods 22, 22. Similarly, a ball joint P and first and second elastic bushings are connected between the end of the rear axle tube 20 and the wheel hub 24, which is a wheel support member that rotatably supports the wheel 23.
It is connected by R ₁ and R ₂ . In addition, in FIG. 3, 25 extends in the longitudinal direction of the vehicle body and is the rear wheel pipe 20.
The front end is rotatably connected to the vehicle body through an eye 26 and the rear end through a shaft 27, respectively. Further, 28 is a differential.

The ball joint P and the first and second elastic bushings in the first to third embodiments are
The arrangement structure of R ₁ and R ₂ will be explained with reference to FIG.

Figure 4 shows wheel 4 (or 1) on the rear right side of the vehicle body.
5, 23) as viewed from the left side (inside) of the vehicle body, and in the horizontal (X axis)-vertical (Z axis) coordinates of the wheel center O standard as seen from the left side of the vehicle body.
The ball joint P is located in the fourth quadrant, the first elastic bush R ₁ is located in the first quadrant, and the second elastic bush R ₂ is located in the second quadrant.

Further, the first elastic bushing _R1 is arranged so that its axis is inclined toward the rear and outside of the vehicle body, and the second elastic bushing _R2 is
Contrary to the elastic bushing _R1 , it is arranged so that its axis is inclined toward the rear and inside of the vehicle body. In addition, in Fig. 4, for the above coordinates (X, Y), the Y-axis in the horizontal left and right direction with respect to the wheel center O is set to create a rectangular coordinate system (X, Y).
Y, Z) is constructed, and the coordinate system (L, M,
N) is a coordinate system whose origin is the center of the ball joint P, which is obtained by moving the above coordinate system in parallel.

Furthermore, each attachment point of the ball joint P, the first elastic bush R ₁ and the second elastic bush R ₂ (in the case of the ball joint P, the center thereof,
In the case of the first and second elastic bushes R ₁ and R ₂ , the triangular mounting surface Q including the central point of each axis
is the intersection line q with the YZ plane of the above coordinate system (X, Y, Z) in the vertical plane containing the wheel center axis
Let W be the offset amount from the wheel center O on the wheel center axis (Y axis), G be the offset amount on the wheel contact surface, and let the offset toward the inside of the vehicle body be plus (+).
The above W is a positive (+) amount (that is, inside the car body),
It is arranged so that G is a negative (-) amount (outside the vehicle body).

Next, to describe the effect on each wheel acting force in this case, (a) Since the lateral force S acts in the +Y direction with respect to the wheel grounding point, the above △
The mounting surface Q of PR ₁ R ₂ rotates approximately clockwise around the N axis around the ball joint P. At that time, since the ball joint P is located in the fourth quadrant and is offset backward from the line of action of the lateral force S, a moment about the L axis is generated, and this moment causes the ball joint P in the second quadrant to Each of the bushes R ₁ and R ₂ is elastically deformed so that the attachment point of the second elastic body bush R ₂ is displaced more toward the inside of the vehicle body than the attachment point of the first elastic body bush R ₁ in the first quadrant. The toe-in will change.

(b) Since the brake force B acts in the +X direction with respect to the wheel grounding point, the mounting surface Q will be approximately L with the ball joint P at the center due to the (-) amount of G in response to the brake force B. The wheel is rotated counterclockwise around the axis, and the toe-in of the wheel changes. At that time, the mounting surface Q further tries to rotate counterclockwise around the M axis around the ball joint P, so the first
The elastic bushing _R1 is displaced inward to the vehicle body, and the second elastic bushing _R2 in the second quadrant is displaced to the outside of the vehicle body.
It will be toe out. Therefore, counterclockwise rotation of the mounting surface Q around the M axis is prevented, and the first
In order to prevent the first elastic bushing R ₁ of the quadrant from being displaced inward of the vehicle body, which would impede the toe-in effect, it is preferable to provide a stopper at the front end of the bushing R ₁ .

(c) Since the engine braking force E acts in the +X direction with respect to the wheel center O, in response to the engine braking force E, the mounting surface Q is approximately clockwise around the M axis around the ball joint P. (toward the rear of the vehicle body). At this time, since the axis of the first elastic bush _R1 is inclined toward the rear outer side of the vehicle body, and the axis of the second elastic body bush _R2 is inclined toward the rear inner side of the vehicle body, the first elastic body bush
R ₁ is displaced to the outside of the vehicle body, and the second elastic bushing R ₂ is displaced to the inside of the vehicle body, resulting in a wheel toe-in change.

(d) The engine driving force K acts on the wheel center O in the -X direction, so for the engine driving force K, the mounting surface Q is smaller than the (+) amount of W on the ball joint P. The wheel is rotated counterclockwise around the L axis, and the wheel changes toe-in. At this time, a stopper may be provided at the front end of the first elastic bushing R 1 to prevent the first elastic bushing R ₁ from being displaced inward to the vehicle interior, which would impede the toe-in effect, as in the case where _the brake force B is applied. preferable.

Figures 5 and 6 show a modification of the arrangement of the mounting surface Q on a vertical plane (YZ plane) including the wheel center axis. In Figure 5, W is a positive (+) amount and G is This is a case where the amount is positive (+), that is, when the mounting surface Q is located inside the vehicle body with respect to the wheel center O. In this case, for lateral force S, engine braking force E, and engine driving force K,
It exhibits the same behavior characteristics as cases (a), (c), and (d) above, and a toe-in effect is obtained, but in response to braking force B, the mounting surface Q rotates clockwise around the L axis with P as the center. Due to the rotational displacement, the wheel changes to toe-out, and no toe-in effect can be obtained.

In addition, in Fig. 6, W and G are both negative (-) amounts, and the mounting surface Q is the wheel center O.
This is the case when the vehicle is located further outside the vehicle body. In this case, the axis of the first elastic bushing _R1 in the first quadrant should be placed on the rear inside of the vehicle body, and the axis of the second elastic bushing R1 in the second quadrant.
The axis of R ₂ is placed so that it is tilted toward the rear and outside of the vehicle body. In response to lateral force S, rotational displacement occurs and toe-in changes in the same way as in case (a) above. In response to the braking force B, the mounting surface Q is rotationally displaced counterclockwise around the M axis or the L axis with P as the center, resulting in a toe-in change. Furthermore, in response to the engine braking force E, the mounting surface Q is rotationally displaced counterclockwise around the L axis with P as the center, and the toe-in changes. At that time, the first elastic bushing that prevents the toe-in change
It is preferable to provide a stopper at the rear end of the bush _R1 to prevent rearward displacement of the bush _R1 . Furthermore, for the engine driving force K, the mounting surface Q is P
A toe-in effect can be obtained by rotating and displacing counterclockwise around the M axis with .

Therefore, in response to the lateral force S, the mounting surface Q rotates around the ball joint P located in the fourth quadrant (that is, below the rear of the wheel center O), and this rotation center P By being offset rearward with respect to the line of action of the lateral force S, the mounting surface Q is reliably rotationally displaced in the toe-in direction, and the toe-in change of the wheels 4 (15, 23) is reliably performed. Therefore, oversteering can be prevented and the running stability of the vehicle can be improved.

In addition, the mounting surface Q rotates around the ball joint P to obtain a toe-in effect with respect to the other brakes B, engine braking force E, and engine driving force K acting on the wheels 4 (15, 23). Therefore, it is possible to further improve running stability.

Moreover, the first and second elastic bushes R ₁ ,
Since R ₂ is located in the first and second quadrants above the wheel center O, and the rotation center P is in the fourth quadrant below the wheel center O,
In response to the lateral force S and the braking force B, only an acting force with a lever ratio of approximately 1:1 acts on each of the bushes R ₁ and R ₂ . Since the acting force is about half smaller than when the bushes R ₁ and R ₂ are located below the wheel center O, the strength design of each of the bushes R ₁ and R ₂ becomes strict and easy. Durability can be increased.

Furthermore, if the center of rotation P is in the fourth quadrant, the lateral force S
Since the distance in the vertical direction from the point of application (grounding point) of the brake force B is relatively short, the wheel 4 (15, 23) in response to the lateral force S and the brake force B
Since there is no movement deviation and the behavior in the toe-in direction can be performed stably, the toe-in effect can be further ensured.

In addition, the toe-in effect can be obtained against the various wheel acting forces by the simple structure of the float connection by combining the ball joint P and the first and second elastic bushes R ₁ and R ₂ .
The rear suspension structure can be significantly simplified compared to the case where a toe-in mechanism is provided for each acting force.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but also includes various other modifications. For example, in the above embodiment, an example was shown in which it is applied to a semi-trailing type, a strut type, and a deion type rear suspension, but the present invention is also applicable to various double link type rear suspensions such as the Witsubon type or various swing arm type rear suspensions. It can also be applied to for example,
In the case of the Utsushu Bon type, a connecting hub that connects two upper and lower arms extending in the left-right direction of the vehicle body constitutes the rear suspension component in the present invention, and the connecting hub and the wheel hub are connected by a ball joint P and a first and second arm. It is sufficient to connect it with the second elastic bushings R ₁ and R ₂ .

Moreover, although the right wheel at the rear of the vehicle body has been described in FIGS. 4 to 6, it goes without saying that the same can be said for the left wheel at the rear of the vehicle body.

As explained above, according to the present invention, the ball joint and the first and The ball joint is float-coupled with the second two elastic bushings, and the ball joint is located in the fourth quadrant in the horizontal-vertical coordinates of the wheel center reference when viewed from the left side of the vehicle body, and the first and second elastic bushings are connected to the first and second elastic bushings. With a simple configuration in which the wheels are located in the first quadrant and the second quadrant, respectively, it is possible to reliably change the toe-in of the wheel in response to lateral force. In addition, it is possible to obtain a toe-in effect with respect to the wheel acting forces of other brake forces, engine braking forces, and engine driving forces. Therefore, with one simple float connection structure, it is possible to obtain a toe-in effect against various wheel acting forces. In contrast, it becomes possible to exhibit toe-in changes, which greatly contributes to improving the running stability of the vehicle and simplifying the rear suspension structure.

Furthermore, in response to wheel acting forces such as lateral forces, the rotation changes around the ball joint located in the fourth quadrant in the wheel center reference coordinates, so each elastic body in the first and second quadrants responds to lateral forces etc. The acting force on the bushing is small, which improves its durability, and the wheel is less likely to shift due to the acting force, resulting in excellent behavior stability in the toe-in direction, making the toe-in effect more reliable. It has the advantage of being able to

[Brief explanation of the drawing]

The drawings illustrate embodiments of the invention, FIG.
FIG. 2 is a perspective view showing the second embodiment; FIG. 3 is a perspective view showing the third embodiment; FIG.
6 through 6 are schematic explanatory diagrams showing examples of the arrangement structure of the ball joint and the first and second elastic bushings, respectively. 1...Semi-trailing arm, 2...Subframe, 3...Wheel hub, 4...Wheel, 10...Strut hub, 12...Suspension arm, 1
3, 14...Subframe, 15...Wheel, 16
...Wheel hub, 20...Rear axle tube, 22...Tension rod, 23...Wheel, 24...Wheel hub, P...Ball joint, _R1 ...First elastic bushing, _R2 ...Second elastic bushing, O...Wheel Center.

Claims (1)

[Claims] 1. A rear suspension component whose one end is rotatably supported on the vehicle body, a wheel support member which rotatably supports a wheel, and a center point between the wheel support member and the rear suspension component. A ball joint that is swingably connected, a first elastic bushing that connects the wheel support member and the rear suspension component, and a first elastic bush that connects the wheel support member and the rear suspension component. and a second elastic bushing, the ball joint is located in the fourth quadrant of the horizontal and vertical coordinates based on the wheel center when viewed from the left side of the vehicle body, and the first elastic bushing is located in the first quadrant of the coordinates. The rear suspension is characterized in that the two elastic bushings _R2 are located in the second quadrant.