JPS6143208B2 - - 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.

In general, when a vehicle is turning in a rear suspension installed on a vehicle, a force (lateral force) directed toward the turning center acts on the left and right wheels, especially the wheels on the outside of the turning center. 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 two points in the front and back, and this connection structure is connected with a spring in the front and back and a pin in the rear (West German patent No.
(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 bushing is reduced to the rear. Rubber bushings made softer than those of
52-37649) has been proposed.

However, in the above-mentioned conventional device, since the lateral force is simply displaced in the toe-in direction of the spring or rubber bushing, the toe-in effect against the lateral force cannot be effectively exerted. Moreover, toe-in effects cannot naturally be expected for wheel acting forces other than lateral forces, such as braking force, engine braking force (so-called 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, it is an object of the present invention to enable the toe-in effect to be exerted also with respect to wheel acting forces other than lateral force, that is, braking force, engine braking force, and engine driving force.

In order to achieve this object, the present invention has a configuration including a rear suspension component whose one end is rotatably supported on the vehicle body, a wheel support member rotatably supports a wheel, and a rear suspension component that rotatably supports the wheel. a ball joint that connects the component member 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 component member. a second elastic bushing that connects the rear suspension component to the rear suspension component; The elastic bushing is located at the second point of the above coordinates.
By positioning the second elastic body bush in the quadrant and the third quadrant, the mounting surface including the three coupling points mentioned above is rotated about the ball joint in response to lateral force, and the wheel changes toe-in. Furthermore, toe-in can be changed by rotational displacement of the mounting surface with respect to other braking forces, engine braking forces, and engine driving forces.

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 subframe 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.

As described later, between the wheel hub 3 and the semi-trailing arm 1, there is a ball joint P that can freely swing around one point, and two first and second elastic bushings made of rubber bushings or the like.
Float bonded by R ₁ and R ₂ . 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. Between the strut hub 10 and the wheel hub 16, which is a wheel support member that rotatably supports the wheel 15, there is a ball joint P and the first and second
They are connected by elastic bushes R ₁ and R ₂ . 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 FIG. 3, reference numeral 25 extends in the longitudinal direction of the vehicle body and represents the rear axle 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) and 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 second quadrant, and the second elastic bush R ₂ is located in the third quadrant.

Further, the first elastic bushing _R1 is arranged so that its axis is inclined toward the rear inside of the vehicle body, and the second elastic bushing _R2 is arranged so that its axis is tilted toward the rear inside of the vehicle body. It is arranged in an inclined direction. In addition, in Fig. 4, a rectangular coordinate system (X, Y, Z) is constructed by setting the Y-axis in the horizontal left and right direction with respect to the wheel center O for the above coordinates (X, Z), 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.

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

Next, to explain its effect, since the lateral force S acts in the +Y direction with respect to the wheel grounding point, it causes the mounting surface Q of △PR ₁ R ₂ above to reflect approximately around the L axis with the ball joint P as the center. By acting as a moment force to rotate clockwise, the mounting surface Q is rotationally displaced around the L axis with P as the center in the toe-in direction, and the wheels 4 (15, 23) change in toe-in.

Brake force B acts in the +X direction with respect to the wheel grounding point, so depending on the (-) amount of G, the mounting surface Q is approximately L centered on the ball joint P.
By acting as a moment force that rotates counterclockwise around the axis, the mounting surface Q is
The wheel 4 (15, 23) is rotationally displaced in the toe-in direction about , and the toe-in of the wheel 4 (15, 23) changes. At this time, in order to prevent the first elastic bushing _R1 from being displaced inward of the vehicle body (that is, forward movement of the wheel) due to the moment force in the counterclockwise direction around the M axis caused by the braking force B, which would impede the toe-in effect. Furthermore, it is preferable to provide a stopper at the front end of the first elastic bushing _R1 in order to ensure the toe-in change.

Engine braking force E acts on the wheel center O in the +X direction, so depending on the (+) amount of W and the (-) amount of G, the mounting surface Q is moved approximately clockwise around the M axis with P as the center. Acts as a moment force that causes rotation. At that time, the axial center of the first elastic bushing _R1 is arranged toward the rear inward direction of the vehicle body, and the axial center of the second elastic bushing _R2 is disposed toward the rearward inward direction of the vehicle body, and in general, the rigidity of the elastic bushings is Since the axial direction is lower than the direction perpendicular to the axial center and has the characteristic that it is easily elastically deformed in the axial direction, the mounting surface Q rotates around P in the toe-in direction and the wheel 4
A toe-in change of (15, 23) will be performed. In this case, an outward force is applied to _the second elastic bushing _R2 , which generates a force that causes toe-out movement around the L axis. Wheel 4 (15,
If a stopper is provided to prevent movement in the toe-out direction of 23), the toe-in change described above can be easily and reliably performed.

Since the engine driving force K acts on the wheel center O in the -X direction, the (+) amount of W acts as a moment force that rotates the mounting surface Q approximately counterclockwise around the L axis around P. As a result, the mounting surface Q is rotationally displaced in the toe-in direction about P, as in the case of the above-mentioned brake force B, and the wheel 4 (15, 23)
The toe-in will change. Also in this case, it is preferable to provide a stopper at the front end of the first elastic bushing _R1 .

Next, the specific structure in the case shown in Fig. 4 above will be explained as shown in Figs.
To explain with Figure 2, the front end is a rubber bush 3.
The rear end of the semi-trailing arm 1, which is rotatably supported on the vehicle body (side frame 2) via 0 and 30, and the wheel hub 3, which rotatably supports the spindle 4a of the wheel 4, are located on the left side of the vehicle body. The ball joint P located in the fourth quadrant of the coordinates (X, Z) based on the wheel center O as seen from the side, the first elastic body bush _R1 located in the second quadrant, and the second elastic body located in the third quadrant. The body is float-coupled by a bushing _R2 . Moreover, as mentioned above, the axis of the first elastic bushing _R1 is directed inward toward the rear of the vehicle body.
The second elastic bushing R ₂ has its axes facing inward toward the rear of the vehicle body, and also has a surface (mounting surface Q) that includes the ball joint P and the first and second elastic bushes R ₁ and R ₂ . ) is the wheel center axis (Y
The wheel center axis (Y
on the inside of the vehicle body (W) from the wheel center O on the
>O) and is located on the outside of the vehicle body (G<O) on the ground contact surface.

As shown in detail in FIG. 8, the ball joint P includes a casing 32 provided at the tip of a first arm portion 31 that protrudes from the wheel hub 3 in the fourth quadrant direction and has a spherical inner surface 32a; The semi-trailing arm 1 is pivoted via a bracket 33 having a U-shaped cross section, and includes a support shaft 34 having a spherical portion 34a in the center that is rotatably fitted into the casing 32. By freely rotating the casing 32 around the portion 34a, the semi-trailing arm 1 and the wheel hub 3 are swingably connected around one point (the center of the spherical portion 34a). There is.

Further, the first elastic bushing _R1 is made of a rubber bushing, and as shown in detail in FIGS. axis 36
, an inner cylinder 37 which is rotatably fitted to the support shaft 36 and interposed between the side walls 35a, 35a of the bracket 35, and a second arm part which projects from the wheel hub 3 in the second quadrant direction. An outer cylinder 39 is fixed to the tip of the inner cylinder 38 and is fitted onto the inner cylinder 37 and has a shorter axial length than the inner cylinder 37, and rubber etc. are filled and fixed between the outer cylinder 39 and the inner cylinder 37. The semi-trailing arm 1 and the wheel hub 3 are rotatably connected to each other. Further, between the outer cylinder 39 on the front side in the axial direction (on the right side in FIG. 9) and one side wall 35a of the bracket 35, a stopper member made of hard rubber, hard synthetic resin, etc. that is more rigid than the rubber 40 is provided. 41 is interposed, and by preventing the forward movement of the outer cylinder 39 (that is, the wheel 4),
When brake force B and engine driving force K act,
A stopper is configured to prevent the forward elastic deformation of the bush _R1 and prevent rotation of the mounting surface Q around the M axis, thereby ensuring a toe-in change of the mounting surface Q around the L axis. That's what I do.

Furthermore, the second elastic bushing _R2 is made of a rubber bushing, and as shown in detail in FIGS. A shaft 43, an inner cylinder 44 which is rotatably fitted to the support shaft 43 and interposed between the side walls 42a, 42a of the bracket 42, and a third cylinder from the wheel hub 3.
An outer cylinder 46 is fixed to the tip of the third arm part 45 projecting in the quadrant direction, is fitted onto the inner cylinder 44, and has a shorter axial length than the inner cylinder 44; and the outer cylinder 46 and the inner cylinder 44. The semi-trailing arm 1 includes a rubber 47 made of rubber or the like filled and fixed between the
and the wheel hub 3 are rotatably coupled to each other. Further, a portion 47a perpendicular to the axial direction of the rubber 47 and extending toward the outside of the vehicle body (lower side in FIG. 12) is made of hard rubber, hard synthetic resin, etc., which has higher rigidity than other portions, and the bushing is
A stopper 48 is configured to prevent the outward movement of the wheel 4 by suppressing the elastic deformation in the outward direction orthogonal to the axial direction of the bush R _{2 .} It ensures displacement toward the inside of the body and ensures a toe-in change.

13 and 14 show a modification of the arrangement of the mounting surface Q on a vertical plane (YZ plane) including the wheel center axis. In FIG. 13, 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, the behavior characteristics are the same as in the above case, and a toe-in effect is obtained, but for braking force B, the The surface Q rotates clockwise around the L axis with P as the center, causing the wheel to change toe out, and no toe-in effect can be obtained.

Further, in FIG. 14, the above-mentioned W and G are both negative (-) amounts and the mounting surface Q is located on the outer side of the vehicle body than the wheel center O. In this case, the axis of the first elastic bushing _R1 is inclined toward the rear and outward of the vehicle body, and the axis of the second elastic bushing _R2 is inclined toward the rear and outward of the vehicle.
In response to lateral force S, rotational displacement occurs and toe-in changes in the same manner as in the above case. In response to braking force B, the mounting surface Q is rotated counterclockwise about the M axis or the L axis with P as the center, and the toe-in changes. 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. In this case, it is preferable to provide a stopper at the rear end of the first elastic bushing R1 in order to prevent rearward displacement of the first elastic bushing _R1 (that is, rearward movement of the wheel) that would impede _the toe-in change. Further, in response to the engine driving force K, the mounting surface Q is rotationally displaced counterclockwise around the M axis with P as the center, and a toe-in effect is obtained.
In this case, an outward force is applied to _the second elastic bushing _R2 , which generates a force that causes toe-out movement around the L axis. If a stopper is provided that has higher rigidity than other parts and prevents movement of the wheel 4 (15, 23) in the toe-out direction, the toe-in change described above can be easily and reliably performed.

Next, the specific structure in the case shown in FIG. 14 will be explained, for example, in FIGS.
This will be explained using Figure 2. Note that the same parts as in FIGS. 5 to 12 are designated by the same reference numerals, and the explanation thereof will be omitted.

In this case, the first and second elastic bushings R ₁ and R ₂ that connect the rear end of the semi-trailing arm 1 and the wheel hub 3 are arranged so that their axes face outward toward the rear of the vehicle. , and the surface including the first and second elastic bushes R ₁ and R ₂ and the ball joint P (mounting surface Q) is aligned with the wheel center axis (Y axis) in a vertical plane including the wheel center axis (Y axis). It is arranged so as to be located on the outer side of the vehicle body (W<O) than the wheel center O on the ground contact surface (G<O) on the ground contact surface.

The structure of the ball joint P and the second elastic bushing _R2 is shown in Fig. 18 and 21 and 22.
As shown in the figure, the stopper member 41 is similar to the _above , and prevents the outer cylinder 39, that is, the wheel 4, from moving backward in the axial direction rearward (left side in the figure) as shown in FIG. 19 in the first elastic bushing R1. ' is provided to ensure that the toe-in changes when the engine braking force E is applied.

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 toe-in 4 (15, 23) is reliably performed. Therefore, oversteering can be prevented and the running stability of the vehicle can be improved.

Moreover, since the ball joint P, which is the center of rotation of the mounting surface Q due to the wheel acting force, is located in the fourth quadrant below the wheel center O, lateral force S and brake force B are applied to the second and third quadrants. Each bush R ₁ and R ₂ has a lever ratio of approximately 1:1.
When the center of rotation P is above the wheel center O, each bush R ₁ ,
Since the acting force is about half smaller than when R ₂ is located below the wheel center O, the strength design of each bushing R ₁ and R ₂ is not difficult and easy, and its durability can be improved. 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 little 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 Uitshubon type, a connecting hub connecting two upper and lower arms extending in the left-right direction of the vehicle constitutes the rear suspension component in the present invention, and the connecting hub and the wheel support member are connected by a ball joint P and a first and the second elastic bushings R ₁ and R ₂ .

Further, in the illustration and explanation above, the right wheel at the rear of the vehicle body has been described, but 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 of the horizontal-vertical coordinates of the wheel center reference when viewed from the left side of the vehicle body. By locating them in the second and third quadrants, it is possible to reliably change the toe-in of the wheel against 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, rotational displacement occurs around the ball joint located in the fourth quadrant in the wheel center reference coordinates, so each elastic body in the second and third 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 schematic perspective view showing the second embodiment, FIG. 3 is a schematic perspective view showing the third embodiment, and FIG. 4 is a schematic perspective view showing the ball joint. A schematic explanatory diagram showing the arrangement structure of the first and second elastic body bushes, FIG. 5 is a detailed plan view showing the specific structure of the first embodiment, FIG. 6 is a side view of the vehicle body as seen from the right side, Fig. 7 is a rear view of the vehicle seen from the rear, Fig. 8 is an enlarged sectional view taken along the - line in Fig. 7, Fig. 9 is an enlarged sectional view taken along the - line in Fig. 5, and Fig. 10 is an enlarged sectional view taken along the - line in Fig. 5. - line cross-sectional view, 1st
Figure 1 is an enlarged sectional view taken along the line XI--XI in Figure 6, Figure 12 is a sectional view taken along the line XII--XII in Figure 11, and Figures 13 and 14 each show a modification of the arrangement structure in Figure 4. The schematic explanatory diagrams shown in Figs. 15 to 22 are the first
5 each showing a modification of the specific structure of the embodiment.
FIG. 12 is a diagram corresponding to FIG. 1...Semi-trailing arm, 2...Subframe, 3...Wheel hub, 4...Wheel,
10... Strut hub, 12... Rear suspension arm, 13, 14... Subframe, 1
5...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 body bush, 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 rocking mechanism between the wheel support member and the rear suspension component about one point. A ball joint movably coupled, a first elastic bushing coupling between the wheel support member and the rear suspension component, and a first elastic bushing coupling the wheel support member and the rear suspension component. the ball joint is located in the fourth quadrant of the horizontal-vertical coordinates of the wheel center reference when viewed from the left side of the vehicle, and the first elastic bushing is located in the second quadrant of the coordinates. and the second elastic bushing is located in a third quadrant of the coordinates.