JPS6144690B2 - - 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.
(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 systems, the lateral force is simply caused by displacement of the spring or rubber bushing in the toe-in direction, so the toe-in effect against the lateral force cannot be effectively exerted. Moreover, it was naturally impossible to expect a toe-in effect against the bump load acting on the wheel during 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 wheel center, and the spring reaction force of the spring unit that functions as a damper in the rear suspension is used to connect the wheel support member to the above-mentioned wheel support member. The purpose 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 by acting appropriately.

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 fourth quadrant of the horizontal-vertical coordinates based on the wheel center, and the first elastic bushing is located in the first quadrant of the coordinates and is arranged with its axis facing outward toward the rear of the vehicle. The second elastic body bush is located in the second quadrant of the above coordinates and is arranged so that its axis is directed inward toward the rear of the vehicle body,
and the plane including the first elastic bushing, the second elastic bushing, and the ball joint is on a vertical plane including the wheel center axis, on the wheel center axis, on the inside of the vehicle body from the wheel center, and on the ground contact surface, on the outside of 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 above 3
The mounting surface including the two connection points is rotationally displaced in the toe-in direction around the ball joint to change the wheel's toe-in, and the above-mentioned mounting surface is moved in the toe-in direction by the downward and outward spring reaction force of the spring unit against the bump load. The wheel is rotated to change the toe-in of the wheel.

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.

There is a gap between the wheel hub 3 and the semi-trailing arm 1 as shown in FIG.
It is float-coupled by a ball joint P that is swingable about a point, and two first and second elastic bushings _R1 and _R2 made of rubber bushings or the like. 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, and the connecting hub 10
is swingably supported by sub-frames 12, 13, which are vehicle body structural members, arranged in the longitudinal 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 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 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, inside the car 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 outward from the vehicle body is generated in the first elastic bushing _R1 , and a force directed toward the vehicle body is generated in the second elastic bushing _R2 , so that the axis of the first elastic bushing _R1 is generated. By making the rigidity in the outward direction orthogonal to the center or the stiffness in the inward 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 force T is generated in the spring units 7, 16, 25 as a reaction force, and this spring force T is applied to a position rearward from the ball joint P of the wheel hub 3, 15, 24. Therefore, the vertical downward force causes the mounting surface Q to move M around the ball joint P.
It acts as a moment force that rotates clockwise (backward rotation direction) around the axis, and its horizontal outward component acts as a moment force that rotates the mounting surface Q counterclockwise around the L axis around P. . As a result, the above M
In response to the moment force around the axis, the axis of the first elastic bushing _R1 is directed outward toward the rear of the vehicle body, and the second
The axis of the elastic bushing _R2 is placed toward the rear and inward 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 axial center, so that it is elastically deformed in the axial direction. Since the mounting surface Q has a characteristic of being easy to bend, 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 first elastic body bushing _R1 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 first elastic body bushing R1 is It is desirable to provide a stopper at the front end of the body bush _R1 in order to ensure toe-in change.

Since the engine braking force (engine braking force) E acts on the wheel center O in the +X direction, it acts as a moment force that rotates the mounting surface Q approximately clockwise around the M axis around the ball joint P. As in the case of the moment force around the M axis due to the spring force T of the spring units 7, 16, 25,
The mounting surface Q is rotationally displaced about P in the toe-in direction, thereby changing the toe-in of the wheels 4, 14, and 23.

Since the engine driving force K acts on the wheel center O in the -X direction, the (+) amount of W causes the mounting surface Q to rotate approximately counterclockwise around the L axis around the ball joint P. By acting as a moment force, as in the case of the brake force B described above, the mounting surface Q rotates in the toe-in direction about P, and the wheels 4, 14, and 23 change in toe-in direction. Also in this case, it is desirable to provide a stopper at the front end of the first elastic bushing _R1 .

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 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 first quadrant, and the second elastic body located in the second quadrant. The body is float-coupled by a bushing _R2 . Further, as described above, the first elastic bushing R ₁ is arranged with its axis facing outward toward the rear of the vehicle body, and the axis of the second elastic bushing R ₂ is disposed with its axis facing inward toward the rear of the vehicle body, and the ball joint P , the surface including the first and second elastic bushes R ₁ and R ₂ (mounting surface Q) is aligned with 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.

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 fourth 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 first 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, although not shown, a stopper is provided at the front end of the first elastic bushing _R1 in the axial direction to prevent forward movement of the bushing portion 36.
When brake force B and engine driving force K are applied, forward inward elastic deformation of bush _R1 is suppressed to prevent rotation of mounting surface Q around the M axis, and toe-in change around the L axis of mounting surface Q is prevented. We make sure to do this.

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 second 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. Furthermore, the portion of the bushing portion 40 that is perpendicular to the axial direction of the rubber 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, and On the other hand, a stopper is configured to restrict the elastic deformation in the orthogonal outward direction, and thus when the lateral force S and the spring force T of the spring unit 7 act, the bush R ₂ is easily displaced inward to the vehicle body, and the toe-in is changed. We make it easy to do this.

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 attached to a rubber bush at the tip of a fourth arm 43 that protrudes from the wheel hub 3 in the fourth quadrant direction and to a position rearward from the attachment point of the ball joint P. They are rotatably connected via 44. Further, the spring unit 7 is arranged to face downward and outward, and when a bump is loaded, a downward and outward spring force T is generated in the spring unit 7, and this spring force T is directed vertically downward and horizontally outward. The toe-in is changed by component force.

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, 23, causing the wheels 4, 14, 23 to rotate. , 23 can be changed in toe-in, the steering stability can be further improved.

In addition, the first and second elastic bushes R ₁ , R ₂
are the first and second wheels above the wheel center O.
Since the ball joint P, which is located in a quadrant and is the center of rotation, is located in the fourth quadrant below the wheel center O, lateral force S and braking force B are applied to each bush R ₁ and R ₂ . The lever ratio is approximately 1:1, and the action force is only applied, compared to the case where the ball joint P is above the wheel center O and the bushes R ₁ and R ₂ are below the wheel center O. Since the force is reduced to about half, the strength design of each bushing R ₁ and R ₂ is simple and not strict, and its durability can be improved.

Furthermore, if the ball joint P is in the fourth quadrant, the point of application of the lateral force S and the brake force B (grounding point)
Since the vertical distance between the wheels 4 and 1 is relatively short,
4 and 23, and the movement in the toe-in direction can be performed stably, making it possible to further ensure the toe-in effect.

In addition, by combining the ball joint P and the first and second elastic bushes R ₁ and R ₂ with a simple structure, and by using the existing spring units 7, 16, and 25, the above various types can be achieved. Since a toe-in effect is obtained for each wheel acting force, the rear suspension structure can be significantly simplified compared to a case where a toe-in mechanism is provided for each individual 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 the present invention is applied to a semi-trailing type, a slat 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 constitutes the swinging member in the present invention, and the connecting hub and the wheel support member are connected to the ball joint P and the first and second elastic bushings R ₁ and R ₂ , and a spring unit may be attached 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 fourth quadrant of the horizontal-vertical coordinates of the wheel center as viewed from the left side of the vehicle body. The first and second elastic bushings are located in the first and second quadrants, respectively, and their axes are oriented outward toward the rear of the vehicle body and toward inward toward the rear of the vehicle body, respectively, and the plane containing the three connection points is In a vertical plane including the wheel center axis, the spring unit is placed on the inside of the vehicle body from the wheel center on the wheel center axis, and on the outside of the vehicle body on the ground contact surface, and furthermore, the spring unit is attached to the wheel support member at a position rearward from the ball joint and directed downward and outward. With a simple installation structure, toe-in effects can be effectively and reliably obtained against lateral forces and bump loads, and toe-in effects can also be obtained against braking force, engine braking force, and engine driving force.
This greatly contributes to improving the handling stability of automobiles and simplifying the rear suspension structure.

Furthermore, in response to wheel acting forces such as lateral forces, the ball joint located in the fourth quadrant in the coordinates based on the wheel center is rotated and displaced, so each elastic body in the first and second quadrants responds to lateral forces, etc. The acting force of the bushing is small, and its durability can be improved, and the wheel operation deviation due to the acting force is small, and the behavior stability in the toe-in direction is excellent, and the toe-in effect is more reliable. I can do it. In addition, the toe-in effect due to bump loads 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 simplifies the structure. This has the advantage of being able to achieve even greater benefits.

[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 fourth quadrant in the horizontal-vertical coordinates of the wheel center as viewed from the left side of the vehicle body, and the first elastic bushing is is located in the first quadrant of the above 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 second quadrant of the above 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 in a vertical plane including the wheel center axis from the wheel center. inside the car body,
The spring unit is arranged so as to be located on the outside of the vehicle body on the ground contact surface, and further, the spring unit is installed at a position rearward from the ball joint connection point of the wheel support member so as to face downward and outward. rear suspension.