JPS6144691B2 - - Google Patents

Description

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

In general, in the rear suspension of a car, when turning, a force (lateral force) and a bump load toward the turning center act on the left and right wheels, especially the wheels on the outside of the turning center. It is known that it is preferable to change the toe-in so that the wheels face inward with respect to the traveling direction in order to prevent oversteering and improve steering 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 swingably 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 bushing is reduced to the rear. Rubber bushings made softer than those of
No. 52-37649) has been proposed.

However, in all of the above-mentioned conventional devices, the toe-in effect against lateral force is not effectively exerted because the toe-in displacement is simply performed by a spring or a rubber bushing against lateral force. Furthermore, toe-in effects cannot be expected against the bump loads that act on the wheels when turning.

Therefore, in view of the above, the present invention provides a structure in which a ball joint and two It is float-coupled with an elastic bushing, and the position of each coupling part is set appropriately with respect to the center of the wheel, and the spring force of the spring unit that functions as a damper in the rear suspension is used to properly connect the wheel support member to the above-mentioned wheel support member. The object of this invention is to improve steering stability by making it possible to reliably change the toe-in of the wheel in response to lateral force and bump load.

In order to achieve this object, the configuration of the present invention includes: a swing member whose one end is swingably supported on the vehicle body; a wheel support member that rotatably supports a wheel;
a ball joint that connects the wheel support member and the swinging member so as to be able to swing around one point; a first elastic bushing that connects the wheel support member and the swinging member; The ball joint is provided with a second elastic bushing that connects the wheel support member and the swinging member, and a spring unit whose upper end is connected to the vehicle body and whose lower end is connected to the wheel support member. The first elastic bushing is located in the first quadrant of the horizontal-vertical coordinates based on the wheel center, and the first elastic bushing is located in the third quadrant of the coordinates, and is arranged with its axis facing outward toward the rear of the vehicle. The second elastic bushing is located in the fourth quadrant of the above coordinates, and is arranged so that its axis is oriented toward the rear and inward of the vehicle body,
and the plane including the first elastic bushing, the second elastic bushing, and the ball joint is located on the wheel center axis on the outside of the vehicle body from the wheel center on the wheel center axis in a vertical plane including the wheel center axis, and on the ground contact surface outside the vehicle body. Further, the spring unit is mounted at a position rearward of the ball joint connection point of the wheel support member so as to face downward and outward. As a result, the mounting surface including the three connection points mentioned above is rotationally displaced in the toe-in direction around the ball joint in response to lateral force, changing the toe-in of the wheel, and the mounting surface containing the above-mentioned connection points is rotated in the spring unit in response to the bump load. The toe-in of the wheel is changed by rotationally displacing the wheel in the toe-in direction by the downward and outward spring reaction force.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a first embodiment in which the present invention is applied to a semi-trailing type rear suspension, in which numeral 1 denotes a semi-trailing arm as a swinging member extending substantially in the longitudinal direction of the vehicle body; One end of the arm 1, that is, a forked front end, is swingably supported by a sub-frame 2, which is a vehicle body component and is disposed in the left-right direction of the vehicle body. Also,
3 is a wheel hub as a wheel support member that rotatably supports the wheel 4;
One end of the drive shaft 6 is connected to the differential 5, and the other end of the drive shaft 6 is connected to the differential gear 5. Furthermore, 7 is a spring unit consisting of a shock absorber 7a and a coil spring 7b, and the upper end of the spring unit 7 is connected to the vehicle body, and the lower end is connected to the wheel hub 3, respectively. Note that 8 is a stabilizer.

The space between the wheel hub 3 and the semi-trailing arm 1 is as shown in FIG. 4, which will be described later.
A ball joint P that can freely swing around one point,
Two first and second parts consisting of rubber bushes etc.
It is float-coupled by elastic bushes R ₁ and R ₂ . The arrangement of the ball joint P, the first and second elastic bushes R ₁ and R ₂ and the spring unit 7 will be described later.

Further, FIG. 2 shows a second embodiment in which the present invention is applied to a strut type suspension, and 10 is a connecting hub as a swinging member.
is swingably supported by sub-frames 12, 13 as vehicle body structural members arranged front and rear in the left-right direction of the vehicle body via two-link suspension arms 11, 11 extending in the left-right direction of the vehicle body. A wheel hub 15 as a wheel support member that rotatably supports the connecting hub 10 and the wheel 14.
As in the first embodiment, there is a connection between the ball joint P and the first and second elastic bushes R ₁ ,
Bonded by R ₂ . Further, the lower end of a spring unit (strut) 16 whose upper end is connected to the vehicle body is connected to the wheel hub 15. In addition, in Fig. 2, 17 is a stabilizer, and 18 is a stabilizer.
is the differential, and 19 is the 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 extending in the left-right direction of the vehicle body and serving as a swinging member into which a rear axle provided separately from the drive shaft 21 is inserted; the rear axle tube 20 has two left and right tension rods extending in the longitudinal direction of the vehicle body. 2
It is swingably supported by the vehicle body via 2 and 22. Similarly, a ball joint P and first and second elastic bushes R ₁ , _R2 , and the lower end of a spring unit 25 whose upper end is connected to the vehicle body is connected to the wheel hub 24. In addition, in FIG. 3, 26 extends in the longitudinal direction of the vehicle body and is the rear axle pipe 20.
The front end is rotatably connected to the vehicle body through an eye 27 and the rear end through a shaft 28, respectively. Further, 29 is a differential.

The ball joint P and the first and second elastic bushings in the first to third embodiments are
The front structure of R ₁ and R ₂ and the arrangement structure of the spring units 7, 16, 25 will be explained with reference to FIG.

Figure 4 shows wheels 4, 14, and 2 on the right side of the rear of the vehicle.
3 viewed from the left side (inside) of the vehicle body, and in the horizontal (X axis)-vertical (Z axis) coordinates based on the wheel center O seen from the left side of the vehicle body, the ball joint P is in the first quadrant. The first elastic bush R ₁ is located in the third quadrant, and the second elastic bush R ₂ is located in the fourth quadrant.

Further, the first elastic bushing _R1 is arranged so that its axis is inclined toward the rear outer side of the vehicle body, and the second elastic bushing _R2 is arranged so that its axis is inclined toward the rearward inner side 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 translating the above coordinate system (X, Y, Z).

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, outside the vehicle body),
It is arranged so that G is a negative (-) amount (outside the vehicle body).

In addition, the spring units 7, 16, 25 are mounted so as to face downward and outward from the mounting points of the ball joints P of the wheel hubs 3, 15, 24 at positions rearward of the vehicle body.

Next, the wheels 4, 1 for that action, i.e. lateral forces, bump loads and other wheel acting forces.
Regarding the movements of 4 and 23, since the lateral force S acts in the +Y direction with respect to the wheel grounding point, the mounting surface Q of ΔPR ₁ R ₂ is moved counterclockwise around the ball joint P approximately around the L axis. By acting as a moment force to rotate the mounting surface Q, the mounting surface Q is
The wheels 14 and 23 are rotationally displaced around the axis in the toe-in direction, and the wheels 14 and 23 change in toe-in. At this time, a force directed toward the vehicle interior is generated in the first elastic bushing _R1 , and a force directed outward from the vehicle body is generated in the second elastic bushing _R2 , so that the axis of the first elastic bushing _R1 is By making the rigidity in the inward direction orthogonal to the center or the rigidity in the outward direction orthogonal to the axis of the second elastic body bushing _R2 lower than other parts, the above toe-in change can be easily and reliably performed. can.

In response to the bump load, a downward and outward spring reaction force T is generated in the spring units 7, 16, 25 as a reaction force, and this spring reaction force T is behind the ball joint P of the wheel hub 3, 15, 24. Since it acts on the position, its vertical downward component acts as a moment force that rotates the mounting surface Q clockwise (backward rotation direction) around the M axis around the ball joint P.
The horizontal outward component of the force acts as a moment force that rotates the mounting surface Q counterclockwise around the L axis with P as the center. As a result, in response to the moment force around the M-axis, the axis of the first elastic bushing _R1 is directed outward toward the rear of the vehicle.
The axis of the second elastic bushing _R2 is placed toward the rear of the vehicle body, and the rigidity of the elastic bushing is generally lower in the axial direction than in the direction perpendicular to the axis, so that it is elastic in the axial direction. Since it has a characteristic of being easily deformed, the mounting surface Q rotates around P in the toe-in direction. In addition, in response to the moment force around the L axis, the mounting surface Q rotates in the toe-in direction about P, as in the case of the lateral force S, and the wheel 4 , 14, and 23 will certainly 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 above mounting surface Q becomes P
The wheels 4, 14, and 23 are rotated and displaced in the toe-in direction around , and the wheels 4, 14, and 23 change in toe-in. At this time, in order to prevent the second elastic body bushing _R2 from being displaced inward of the vehicle body which impedes the toe-in effect due to the moment force in the counterclockwise direction around the M axis caused by the brake force B, the second elastic body bush R2 is It is desirable to provide a stopper at the rear end of the body bush _R2 in order to ensure toe-in change.

Engine braking force (engine braking force) E acts in the +X direction with respect to the wheel center O, so depending on the (-) amount of W, the mounting surface Q can be moved approximately counterclockwise around the L axis around the ball joint P. By acting as a moment force to rotate in the direction, the mounting surface Q is rotationally displaced in the toe-in direction about P, similarly to the case of the brake force B described above, and the wheels 4, 14, and 23 change in toe-in. Also in this case, it is desirable to provide a stopper at the rear end of the second elastic bushing _R2 .

Since the engine driving force K acts in the -X direction with respect to the wheel center O, it acts as a moment force that rotates the mounting surface Q clockwise around the ball joint P approximately around the M axis. Unit 7,1
Similarly to the case of the moment force around the M axis due to the spring reaction force of 6 and 25, the mounting surface Q is rotationally displaced in the toe-in direction about P, and the toe-in change of the wheels 4, 14, and 23 is performed. Become.

Next, the specific structure of the first embodiment (semi-trailing type rear suspension) will be explained with reference to FIGS. 5 to 7. The front end has a rubber bush 3.
The rear end of the semi-trailing arm 1, which is swingably supported on the vehicle body (side frame 2) via the wheels 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 first 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 third quadrant, and the second elastic body located in the fourth quadrant. The body is float-coupled by a bushing _R2 . In addition, as mentioned above, the axis of the first elastic bushing _R1 is directed outward 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
axis) on the outside of the vehicle body from the wheel center O (W<
0) and on the outside of the vehicle body (G<0) on the ground contact surface.

The ball joint P is connected to a casing 32 provided at the tip of a first arm portion 31 protruding from the wheel hub 3 in the first quadrant direction, and a bracket 33 having a U-shaped cross section to the semi-trailing arm 1. and a support shaft 34 having a spherical part in the center that rolls within the casing 32. By freely rotating the casing 32 around the spherical part of the support shaft 34, one point can be fixed. The semi-trailing arm 1 and the wheel hub 3 are swingably connected around the center.

The first elastic bushing _R1 is made of a rubber bushing, and includes an outer cylinder fixed to the tip of the second arm part 35 protruding from the wheel hub 3 in the third quadrant direction, and an inner cylinder inserted into the outer cylinder. A bushing part 3 formed by filling and fixing rubber made of rubber or the like between
6, and a support shaft 38 rotatably inserted into the inner cylinder of the bushing portion 36 and pivotally supported by the semi-trailing arm 1 via a bracket 37 having a U-shaped cross section. and the wheel hub 3 are rotatably coupled to each other. Further, a portion of the first elastic bushing R ₁ that is perpendicular to the rubber axis direction of the bushing portion 36 and extends toward the outside of the vehicle body is made of hard rubber, hard synthetic resin, etc., which has higher rigidity than other portions. It constitutes a stopper that restricts the elastic deformation of the bush R ₁ in the outward direction orthogonal to the axial direction, and therefore, when the lateral force S and the spring reaction force T of the spring unit 7 act, the bush R ₁ is directed toward the inside of the vehicle. This makes it easy to change the toe-in.

Further, the second elastic bushing _R2 is made of a rubber bushing, and includes an outer cylinder fixed to the tip of the third arm part 39 protruding from the wheel hub 3 in the fourth quadrant direction, and an inner cylinder inserted into the outer cylinder. A bushing part 40 is formed by filling and fixing rubber made of rubber or the like between the bushing part 40 and a bracket 41 which is rotatably inserted into the inner cylinder of the bushing part 40 and which is connected to the semi-trailing arm 1 through a bracket 41 having a U-shaped cross section. The support shaft 42 is supported by
The semi-trailing arm 1 and the wheel hub 3 are rotatably coupled to each other. Further, although not shown at the rear end in the axial direction of the second elastic bushing _R2 , a bushing portion 40 is provided.
A stopper is arranged to prevent the rearward movement of the bushing R2, and prevents the rearward inward elastic deformation of the bushing _R2 from occurring when the brake force B and engine braking force E are applied, thereby preventing rotation of the mounting surface Q around the M axis. In this way, the toe-in change around the L axis of the mounting surface Q is ensured.

In addition, a spring unit 7 is disposed between the wheel hub 3 and the vehicle body and extends substantially vertically. The spring unit 7 consists of a shock absorber 7a and a coil spring 7b arranged around the outer periphery of the shock absorber 7a.
Its upper end is connected to the vehicle body via a mount rubber, while its lower end is the tip of a fourth arm portion 43 that protrudes rearward from the tip of the first arm portion 31 of the wheel hub 3 (the attachment point of the ball joint P). It is rotatably connected to via a rubber bush 44. Further, the spring unit 7 is arranged to face downward and outward, and when a bump is loaded, a spring reaction force T is generated in the spring unit 7 in a downward and outward direction, and this spring force T is directed vertically downward and horizontally outward. The toe-in is changed by the force component. In addition, the above-mentioned shock absorber 7
The lower end of a is curved to prevent interference with the wheel 4.

Therefore, due to the arrangement structure of the ball joint P and the first and second elastic bushings R ₁ and R ₂ as well as the arrangement structure of the spring units 7, 16, and 25 as described above, the lateral force S and the bump load can be suppressed. , the mounting surface Q rotates around the ball joint P to reliably change the toe-in of the wheels 4, 14, and 23, thereby preventing oversteering when turning, etc., and improving the steering of the vehicle. Stability can be significantly improved.

Moreover, the mounting surface Q rotates around the ball joint P in response to other braking force B, engine braking force E, and engine driving force K acting on the wheels 4, 14, and 23. 14 and 23 can be changed in toe-in, it is possible to further improve steering stability.

In addition, the above various types can be achieved by a simple float connection by combining the ball joint P and the first and second elastic bushes R ₁ and R ₂ and by using the existing spring units 7, 16, and 25. Since a toe-in effect is obtained for the wheel acting force, 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 is shown in which the invention is applied to a semi-trailing type, a strut type, and a deion type rear suspension. This can also be applied to sion. for example,
In the case of the Uitschubon type, a connecting hub that connects two upper and lower arms extending in the left-right direction of the vehicle body constitutes the swinging member in the present invention, and the connecting hub and the wheel support member are connected to a ball joint P and a first and second arm. It is sufficient to connect the two elastic body bushes R ₁ and R ₂ and to attach a spring unit to the wheel support member.

Moreover, although the right wheel at the rear of the vehicle body has been described in FIGS. 4 to 7, 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, between the swinging member whose one end is swingably supported on the vehicle body and the wheel support member which rotatably supports the wheel,
A ball joint is float-coupled with two first and second elastic bushings, and the ball joint is located in the first quadrant in the horizontal-vertical coordinates of the wheel center as viewed from the left side of the vehicle body. and second elastic bushings are located in the third and fourth quadrants, respectively, and their axes are arranged facing outward to the rear of the vehicle body and facing inward to the rear of the vehicle body, respectively, and the plane including the above three connection points is aligned with the wheel. In a vertical plane including the center axis, the spring unit is placed on the wheel center axis on the outside of the vehicle body and on the ground contact surface on the outside of the vehicle body, and the spring unit is attached to the wheel support member at a position rearward from the ball joint facing downward and outward. With this simple structure, toe-in effect can be effectively and reliably obtained against lateral force and bump load, and
Since a toe-in effect is also obtained for the brake force, engine braking force, and engine driving force, this greatly contributes to improving the handling stability of the automobile and simplifying the rear suspension structure.

In addition, the toe-in effect due to the bump load mentioned above can be effectively and reliably achieved by using the horizontal and vertical components of the spring reaction force of the existing spring unit, which not only further improves handling stability but also improves the structure. This has the advantage of further simplification.

[Brief explanation of the drawing]

The drawings illustrate embodiments of the invention, 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 and the first, second embodiment.
A schematic explanatory diagram showing the arrangement structure of the second elastic body bush and the spring unit, FIG. 5 is a plan view showing the specific structure of the first embodiment, FIG. 6 is a side view as seen from the right side of the vehicle body, The figure is a rear view of the vehicle seen from the rear. 1...Semi-trailing arm, 3...Wheel hub, 4...Wheel, 7...Spring unit, 10...Connection hub, 11...Suspension arm, 14...Wheel, 15...Wheel hub, 16 ... Spring unit (strut), 20 ... Rear axle tube, 22 ... Tension rod, 23 ... Wheel, 24 ... Wheel hub, 25 ... Spring unit, P ... Ball joint, R ₁ ... First Elastic bushing, R ₂ ...
...Second elastic body bush, O...Wheel center.

Claims (1)

[Claims] 1. A rocking member whose one end is rockably supported on the vehicle body, a wheel support member that rotatably supports a wheel, and a rocking connection between the wheel support member and the rocking member about one point. a first elastic bushing that connects the wheel support member and the swinging member; a second elastic bushing that connects the wheel support member and the swinging member; The vehicle body is provided with a spring unit whose lower end is connected to the wheel support member, the ball joint is located in the first quadrant in the horizontal-vertical coordinates of the wheel center as seen from the left side of the vehicle body, and the first elastic bushing is is located in the third quadrant of the above-mentioned coordinates, and is arranged so that its axis faces outward toward the rear of the vehicle body, and the second elastic bushing is located in the fourth quadrant of the above-mentioned coordinates, and its axis faces outward toward the rear of the vehicle body. The first elastic bushing, the second elastic bushing, and the ball joint are arranged so as to face rearward and inward, and the plane including the three members is located on the wheel center axis from the wheel center in a vertical plane including the wheel center axis. The spring unit is located on the outside of the vehicle body and on the ground contact surface, and the spring unit is installed at a position rearward of the ball joint connection point of the wheel support member so as to face downward and outward. A distinctive feature of the car's rear suspension.