JPS6146341B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a rear suspension for an automobile, and particularly to a novel rear suspension with excellent toe-in effect. BACKGROUND ART In the rear suspension of an automobile, in order to improve steering stability, riding comfort, etc., there is a desire for a rear suspension that allows tires to be toe-in during driving, especially when cornering. In other words, as is well known, when cornering, the centrifugal force applied to the vehicle body acts on the suspension as a lateral force.
In order to increase the turning limit G, it is desirable for tires to counteract this lateral force with a large resistance force. This drag can be increased by toe-in the tire and increase the slip angle. Also, if you increase this drag and improve the grip of the rear wheels, you can strengthen the tendency to understeer.
It can improve the stability of the car. moreover,
When cornering, when you press and release the accelerator, driving force and braking force are applied to the tires, but when you release the accelerator, the tires tend to suddenly toe out, and when you press the accelerator, they tend to toe in. This causes the tires to toe in or toe out during cornering, resulting in a decrease in steering stability (hereinafter referred to as steering stability). Also, when you step on the brakes or apply engine braking, the rubber bushings installed to improve riding comfort are located inside the tire's ground contact point, so the braking force can cause toe-out. This results in poor handling. The softer the rubber bushings, the better the ride comfort, so the more comfortable a car is, the worse it will be in handling.
Therefore, a rear suspension that provides toe-in even when braking force is applied by the brake or engine brake is desired. In other words, a rear suspension that always has a tendency to toe-in will always achieve stable cornering. Furthermore, the toe-in tendency of the rear suspension is desirable not only when cornering, but also from the standpoint of high-speed straight-line performance, which is particularly required for sports cars. That is, the road surface is actually not completely flat and always has irregularities of various sizes, but these irregularities cause disturbances to the tires from various directions. In addition, the wind that the car receives while driving acts as a lateral force when there is a crosswind, but even when there is no crosswind, the wind acts on the car's tires as a disturbance from all directions. Even in response to these disturbances, if the rear suspension always acts to toe-in the rear wheels, the car will tend to understeer and become stable. Regardless of the cause, these disturbances end up acting on the tires as one of the aforementioned lateral forces, braking forces, and driving forces. Therefore, the rear suspension is desired to have the effect of toe-in the tires against all of the lateral force, braking force (there are two types: braking and engine braking), and driving force. To explain these external forces in detail, the lateral force represented by the thrust load during cornering is the force that acts from the outside to the inside of the tire's grounding point, and the braking force when applying the brakes is the force that acts in front of the tire's grounding point. The force from the engine brake is the force that acts on the wheel center of the tire from front to back, and the driving force is the force that acts on the wheel center from the back to the front. This can be expressed in a table as shown below.

[Table] Various types of rear suspensions have been known that have a toe-in effect against lateral force during cornering, but all of them are structurally somewhat complex. For example, the one described in Japanese Patent Publication No. 52-37649 uses three rubber bushings and the hardness of the bushings is changed, and the one described in West German Patent Publication No. 2158931 or West German Patent Publication No. 2355954 is The wheel hub is supported via a vertical shaft and a spring, making the structure complex.
Further, this kind of rear suspension that is known in the past does not achieve toe-in effects against all of the above four types of external forces, but is mainly effective only against lateral forces. SUMMARY OF THE INVENTION An object of the present invention is to provide a novel rear suspension that has an extremely simple structure and can effectively toe-in the rear wheels against external forces, especially during cornering. Furthermore, the present invention has an extremely simple structure that enables toe-in of the rear wheels in response to any external force such as lateral force, braking force, engine braking force, or driving force, regardless of whether the vehicle is turning or going straight. The aim is to provide a completely new type of rear suspension that makes it possible to create highly safe cars. In the rear suspension of the present invention, a rear wheel support member is connected to a swinging member whose part is swingably supported on the vehicle body through one ball joint and two rubber bushes, and further A stabilizer that has a rotation center in the left-right direction of the vehicle body and is rotatably supported by the vehicle body via a control link is connected to a wheel support member, and in particular, the ball joint is the wheel center reference when viewed from the left side of the vehicle body. At least one of the rubber bushes is located in the fourth quadrant of the horizontal-vertical coordinates of the wheel, and at least one of the rubber bushes is located forward of the wheel center, and the plane containing these two rubber bushes and the ball joint is in the vertical plane containing the wheel center axis. Disposed outward from the vehicle body from the left and right center of the wheel at the height of the wheel center, and oriented such that the shaft of the rubber bushing guides the counterclockwise rotation of the wheel support member around the ball joint inward in front of the wheel center. and the swinging member is mounted so that the rotation locus of the wheel support member moves outward in the left-right direction of the vehicle body when bumping, and the end of the stabilizer is positioned forward of the ball joint and the swinging member is It is characterized in that it is connected to the wheel support member below the center of motion. In the present invention, the swinging member refers to a swinging support member on the vehicle body side that is partially supported swingably on the vehicle body, such as a semi-trailing arm of a semi-trailing type rear suspension, or a strut-type rear suspension. A general term for various support members attached to the vehicle body, such as the pension strut, the upper and lower arms of a suspension type rear suspension, and the front tube of a rear suspension type. It is not limited to the format. In addition, wheel members are a general term for members such as wheel hubs that rotatably support tires.
It is not limited to a specific wheel hub. In addition, the control link is a link member that is connected between a bracket that supports the center portion of the stabilizer extending in the left-right direction of the vehicle body and a bracket on the vehicle body side in order to support the stabilizer on the vehicle body while allowing the stabilizer to be slightly displaced. be. Furthermore, the quadrant defined in the present invention is a quadrant in rectangular coordinates when looking at the rear wheel from the left side of the vehicle body and imagining horizontal and vertical orthogonal axes with the wheel center as the center. All quadrants include the axes at both ends that limit the quadrant (for example, in the first quadrant, the right half of the horizontal axis and the upper half of the vertical axis). In the present invention, the direction of rotation of the wheel support member is also expressed as clockwise, counterclockwise, etc. when viewed from the left side of the vehicle body. According to the rear suspension of the present invention, when a lateral force is applied during cornering, it is possible to effectively toe-in the tire. Due to the arrangement of the ball joint and rubber bush, lateral force causes the wheel support member to rotate in the toe-in direction around the ball joint, and the stabilizing reaction force due to one side bump during cornering displaces the wheel support member in the toe-in direction. This is because it works like this. Further, according to the present invention, it is possible to effectively toe-in the tire when any of the four types of external forces are applied. This is also an effect of the arrangement of the ball joint and rubber bush. Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a conceptual diagram showing the basic structure and function of an embodiment of the rear suspension of the present invention. The right rear wheel is shown in the center as seen from the left (inside);
Projection views from the rear, left, and top are shown on the right and below, respectively. The ball joint 11 is disposed on the lower side behind the wheel center W (that is, in the fourth quadrant of the coordinates), and is located between the two rubber bushes 12, 1.
3 is located forward of the wheel center W (ie, in the second or third quadrant of the coordinates). Also, these two rubber bushes 1
The plane P that includes the three parts 2, 13 and the ball joint 11 is the height of the wheel center in the vertical plane that includes the wheel center axis C (its projection is shown on the left in Figure 1).
It is located outward of the vehicle body from the left and right center W of the wheel on the CL and ground GL. Furthermore, the shafts 12 of the rubber bushes 12 and 13
a and 13a are arranged in such a direction as to guide the wheel hub 10 inwardly in front of the wheel center W when the wheel hub 10 rotates counterclockwise around the ball joint, that is, in a direction that causes the tire 14 to be toe-in. . That is, the front rubber bushing 12 is oriented forward inward, and the rear rubber bushing 13 is oriented forward outward.
This direction may be reversed depending on the position of the rubber bushes 12, 13. That is, for example, when the front rubber bush 12 is arranged horizontally or diagonally toward the bottom of the third quadrant with the front high and the rear low, the axis 12a is not directed forward inward but rearward inward. . This is for the purpose of displacing the counterclockwise rotation of the wheel hub 10 around the ball joint 11 in the toe-in direction in either case. Also, from the wheel hub 10 to the front hair arm 15
extends, and a rear end 16a of a rearward bending portion 16A of the stabilizer 16 is connected to a front end 15a of the arm 15. Center part 16B of stabilizer 16
A control link 17 extends in the left-right direction of the vehicle body and has one end 17a connected to a vehicle body side bracket 18.
It is supported by the other end 17b via a bracket 19, and is rotatably supported in the left-right direction of the vehicle body. Therefore, at the time of a bump, the end portion 16a of the stabilizer 16 can move in the vertical direction along the vertical trajectory A in the projection view on the left side of FIG. On the other hand, the wheel hub 10 is supported by a swing member that is a support member on the vehicle body side, such as a semi-trailing arm that is partially swingably supported by the vehicle body.
This swing member is attached so that the rotation locus of the wheel hub moves outward in the left-right direction of the vehicle body (as shown by locus B on the left in FIG. 1) when the vehicle bumps. Further, the connecting portion between the end portion 16a of the stabilizer and the front end 15a of the arm 15 of the wheel hub 10 is located forward of the ball joint 11 and below the center of swing of the swing member. Hereinafter, the toe-in effect due to external force will be explained in detail in the case of this embodiment with reference to FIG.
In FIG. 1, the vertical imaginary axis passing through the ball joint 11 is L, the imaginary axis in the width direction of the vehicle body is M, and the imaginary axis in the longitudinal direction is N. Lateral force (S) acts on the tire's grounding point G from outside to inward, braking force (B) acts on the tire's grounding point G from front to rear, and engine braking force (E)
acts on the wheel center W from front to rear,
The driving force (K) acts on the wheel center W from the rear to the front. When a lateral force (S) is applied to the tire during cornering, a rotational moment is generated around the L axis in a counterclockwise direction when viewed from above, and the rubber bushing 12,
Due to the elasticity of the wheel hub 13, the wheel hub 10 is displaced around the ball joint 11 in the toe-in direction.
At this time, if the elasticity of the front rubber bushing 12 on the inside in the right angle direction and the elasticity of the rear rubber bushing 13 on the outside in the right angle direction are increased, an even greater toe-in effect can be obtained. At the same time, due to a one-sided bump during cornering, the wheel hub 10 attempts to move upward and outward along the trajectory B of the end 15 of the arm 15;
At this time, the stabilizing reaction force HF is received inward due to the upward trajectory A of the end 16a of the stabilizer 16. Therefore, the front portion of the wheel hub 10 is displaced inward, and therefore in the toe-in direction.
Further, at this time, a vertical component VF of the stabilizing reaction force from the stabilizer 16 acts downward on the front end 15 of the arm 15 of the wheel hub 10. The vertical component force VF of this stabilizer reaction force causes the wheel hub 10 to
rotates around the ball joint 11 in a counterclockwise direction (as viewed from the left). This clockwise rotation causes the front of the wheel hub 10 to be displaced inwardly and the rear to be outwardly due to the orientation of the axes of the rubber bushes 12 and 13, as described above, and as a result, the wheel hub 10 is displaced in the toe-in direction. In this way, during cornering, both the lateral force (S) and the stabilization reaction force (HF, VF) produce a toe-in effect, making it possible to effectively toe-in the tire. Next, the toe-in effect due to brake force (B), engine brake force (E), and driving force (K) will be explained. When the braking force (B) acts on the grounding point G from front to back, the wheel hub 10 is in contact with the ball joint 1 because the grounding point G is inside the plane P that includes the ball joint 11 and the rubber bushes 12 and 13.
1 (around the L axis) in the counterclockwise direction, that is, in the toe-in direction T when viewed from above. moreover,
This braking force (B) has the effect of trying to rotate the wheel hub 10 counterclockwise (as viewed from the left) around the M axis. As a result, the wheel hub 10 is further displaced in the toe-in direction. Engine braking force (E) is at wheel center W
When acting from front to back, the tire tries to rotate clockwise around the M axis. The clockwise rotation around the M-axis tends to displace the wheel hub 10 in the toe-out direction depending on the orientation of the rubber bushes 12 and 13. Therefore, in order to prevent this clockwise rotation, a stopper is provided on the rear side of either one of the rubber bushes 12, 13, thereby ensuring toe-in. on the other hand,
At this time, wheel center W is ball joint 1
1 and the rubber bushes 12 and 13, the engine braking force (F) acts in the toe-in direction around the L axis,
In the end, a toe-in effect is obtained. When the driving force (K) acts on the wheel center W from rear to front, this is a force in the opposite direction to the engine braking force (E), so the wheel hub 10 tends to toe out around the L axis and rotate around the M axis. As a result of the comprehensive action of the toe-in tendency due to the orientation of the rubber bushes 12 and 13, toe-out is prevented, and a toe-in effect is obtained. As is clear from the detailed description of the above embodiments,
According to the present invention, the effect of toe-in the tire when any of the four external forces, lateral force (S), braking force (B), engine braking force (E), and driving force (K), is applied In addition, a rear suspension can be obtained which has the effect of toe-in the tire on the bumped side by stabilizing reaction force (VF, HF) even when there is a bump on one side due to cornering or the like. Therefore, it is possible to realize a vehicle that is constantly stabilized during driving such as cornering, and that has improved maneuverability without impairing ride comfort.
Furthermore, this toe-in effect is advantageous in realizing a sports car with excellent straight-line performance at high speed, so the rear suspension according to the present invention has extremely high practical value. Next, examples in which the present invention is applied to a semi-trailing type rear suspension will be described in Sections 2A and 2.
This will be explained with reference to FIGS. B, 2C, 3A, 3B, 4A, 4B, and 5. Figure 2A is a view of the right rear wheel viewed from above, Figure 2B is a side view of it viewed from the right outside (however, the tires are shown with imaginary lines),
Figure C is a rear view of the tire of Figure 2A. Two arms 20A, 2 extending forward in a bifurcated shape
The front end of each arm 20A, 20B of the semi-trailing arm 20 having 0B is attached to a shaft support 21 on the vehicle body.
a, 21b, and a wheel hub 22 is supported by a ball joint 23, a first rubber bush 24 and a second rubber bush on the outside of the rear main body 20C.
It is supported via a rubber bushing 25. The wheel hub 22 also has an arm 22 extending forward.
A is integrally provided, and the rear end of a rearward bending portion 27A of a stabilizer 27 supported by the vehicle body via a control link 26 is connected to the front end of this arm 22A. The cross section of the front rubber bush 24 is shown in No. 3A, 3.
Shown in Figure B. As is clear from these cross-sectional views, the rubber bush 24 is integrally rotated with the wheel hub 22 so as to allow the wheel hub 22 to be largely displaced inward of the vehicle body, but not vice versa, that is, to prevent the wheel hub 22 from being displaced outward. A rubber 24a between the arm portion 22a and the shaft portion 20d that is integrally fixed to the main body 20c of the semi-trailing arm 20.
is made softer on the outside of the car body and harder on the inside of the car body. That is, a hard rubber or a stopper 24a' is inserted between the shaft portion 20d and the inside of the arm 22a to prevent the arm 22a from moving outward. The cross section of the rear rubber bushing 25 is shown in No. 4A, 4.
Shown in Figure B. As clearly shown in FIG. 4A, the rear flange 20e of the pair of flanges fixed to the main body 20c side of the semi-trailing arm
A stopper 25a is provided between the arm 22b and the arm 22b on the wheel hub 22 side to prevent forward displacement. FIG. 5 is a sectional view showing details of the ball joint 23, in which the arm 22B integrally provided on the wheel hub 22 is connected to the semi-trailing arm 20.
It is rotatably supported on the flange 20f and shaft 20g on the main body 20c side. This shaft 20g has a spherical surface and forms a ball of a ball joint. The effects on the four types of external forces and stabilizing reaction forces in this embodiment are exactly the same as those in the embodiment shown in FIG. 1, and are clear from the figure, so a description thereof will be omitted. That is, any of these forces can change the toe-in of the tire and achieve the desired effect.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram showing the main parts of the rear suspension of the present invention in detail, showing a perspective view of the right rear wheel seen from the left rear and its three-way projection view, and FIG. 2A is a semi-sectional view showing the rear suspension of the present invention. Fig. 2B is a partially cutaway top view of the right rear wheel showing an example of application to a trailing type rear suspension; Fig. 2B is a side view of the example shown in Fig. 2A, looking through the tire from the right outside; Fig. 2C is a Figure 2A viewed from the left, Figure 3A is the front rubber bushing 2.
4, FIG. 3B is a central cross-sectional view thereof, and FIG. 4A is a longitudinal cross-sectional view of the rear rubber bushing 25.
4B is a central cross-sectional view thereof, and FIG. 5 is a vertical cross-sectional view of the ball joint 23. 10... Wheel hub, 11, 23... Ball joint, 12, 13, 24, 25... Rubber bush, 14... Tire, 15, 22A... Arm, 16, 27... Stabilizer, 17, 26
...Control link, 20...Semi-trailing arm.

Claims (1)

[Claims] 1. A rocking member whose part is swingably supported on the vehicle body;
A wheel support member that rotatably supports the rear wheel is supported at three points on this swing member via a ball joint and two rubber bushes, and a wheel support member has a rotation center in the left-right direction of the vehicle body and is supported at three points via a control link. The stabilizer is rotatably supported on the vehicle body, the ball joint is located in the fourth quadrant of the horizontal-vertical coordinates based on the wheel center when viewed from the left side of the vehicle body, and at least one of the two rubber bushes is attached to the wheel. Located in front of the center, these two rubber bushes and three ball joints
The surface containing the rubber bushing is disposed outward of the vehicle body from the left and right center of the wheel at the height of the wheel center in a vertical plane including the wheel center axis, and the shaft of the rubber bush is located at the rear side of the vehicle body around the ball joint of the wheel support member. The swinging member is arranged in such a direction as to guide clockwise rotation inward in front of the wheel center, and the swinging member is mounted so that the rotation locus of the wheel support member moves outward in the left-right direction of the vehicle body when bumping. A rear suspension for an automobile, wherein an end of the stabilizer is connected to a wheel support member forward of the ball joint and below the center of swing of the swing member.