JPS6144689B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a rear suspension for an automobile, and more 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., it is desired to have 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 maneuverability). 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 quality, 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. In addition, the tendency of rear suspension toe-in is not limited only when cornering.
This is also desirable from the viewpoint 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 if it is not a crosswind, it 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, resulting in comfortable handling. 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 one end is swingably supported on the vehicle body through one ball joint and two rubber bushes, and The control rod of the stabilizer is connected to the support member, and in particular, the ball joint is arranged above the wheel center, at least one of the rubber bushes is arranged below the wheel center, and these two rubber bushes and the ball joint are arranged above the wheel center. A plane including the three parts is arranged outward of the vehicle body from the left and right center of the wheel at the height of the wheel center and on the ground in a vertical plane including the wheel center axis, and the axis of the rubber bushing is placed on the vehicle body around the ball joint of the wheel support member. The control rod is arranged so as to guide clockwise rotation seen from the left side inwardly in front of the wheel center, and the control rod is arranged so as to be inclined downwardly and outwardly, and the wheel support member is arranged behind the ball joint. It is characterized by being connected to. In the present invention, the swinging member refers to a swinging support member on the vehicle body side whose one end is swingably supported on the vehicle body, such as a semi-trailing arm of a semi-trailing type rear suspension, or a strap-type rear suspension. This is a general term for various support members attached to the vehicle body, such as struts, upper arms and lower arms of Utsubon-type rear suspensions, and tubes of Deion-type rear suspensions. It is not limited to those of. Further, the term "wheel support member" is a general term for members such as wheel hubs that rotatably support tires, and is not limited to a specific wheel hub. In addition, the control rod is a link member connected between the end of the stabilizer and a part of the wheel support member in order to transmit the stabilization reaction force of the stabilizer to the wheel support member. It transmits power. 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 is transmitted to the wheel support member via the control rod. This is because it acts to displace the toe-in direction. Further, according to the present invention, it is possible to effectively toe-in the tire even 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 perspective view showing an example in which the present invention is applied to a strut type twin link rear suspension. A tire 1 is attached to the rear end of a trailing link 11 extending rearward from the end of the vehicle body side mount 10.
Three arms 1 supporting two wheel hubs 18
Bracket 13 having 3A, 13B, 13C is connected. This bracket 13 is connected to the lower end of the shock absorber 25 and to the tips of a pair of lateral links 14. Further, a drive shaft 17 extending laterally from a differential case 16 fixed to the cross member 15 is rotatably supported on the wheel hub 18 . Each arm of the bracket 13 has a wheel hub 1
8 is connected to the ball joint 21 through two rubber bushes 19 and 20 and the ball joint 21.
It is attached so that it can be rotated freely. The wheel hub 18 is integrally provided with an arm 22 extending rearward, and a control rod 24 whose one end is connected to the end 23a of the stabilizer 23 is connected to the rear end 22a of this arm 22. The stabilizer reaction force is transmitted to the arm 22. The ball joint 21 is located above the wheel center and is connected to two rubber bushes 19, 20.
One side 19 is located below the wheel center. Further, the control rod 24 is arranged to be inclined downwardly and outwardly, and is connected to an arm extending rearwardly from the wheel hub 18 to transmit the stabilizing reaction force downwardly and outwardly to the wheel hub 18. The main parts of FIG. 1 are shown in detail in FIG. 2. FIG. 1 is a view of the left rear wheel viewed from the front left, and FIG. 2 is a view of the right rear wheel viewed from the left (inside) rear, and corresponding members are designated by the same reference numerals. As clearly shown in FIG.
0 is located below the wheel center w (ie, in the third or fourth quadrant of the coordinates). Also, these two rubber bushes 1
9, 20 and the ball joint 21 is the height of the wheel center in the vertical plane including the wheel center axis c (its projection is shown on the left in Figure 2).
It is located outward from the vehicle body from the left and right center w of the wheel on the CL and ground CL. Furthermore, the shaft 19 of the rubber bushes 19, 20
a, 20a are arranged in such a direction as to guide the wheel hub 18 inwardly in front of the wheel center w when the wheel hub 18 rotates clockwise around the ball joint, that is, in a direction that tone the tire 12. That is, the rear rubber bushing 19 is oriented rearward inward, and the front rubber bushing 20 is oriented rearward outward. This direction may be reversed depending on the position of the rubber bushes 19, 20. That is, for example, when the front rubber bushing 20 is arranged horizontally or diagonally in the upper part of the second quadrant with the rear high and the front low, the axis 20a is directed rearward inward rather than rearward outward. . This is because, in both cases, the clockwise rotation of the wheel hub 18 around the ball joint 21 is displaced in the toe-in direction. Hereinafter, the toe-in effect due to external force will be explained in detail in this embodiment with reference to FIG.
In FIG. 2, the vertical imaginary axis passing through the ball joint 21 is L, and the imaginary axis in the width direction of the vehicle body is M. The lateral force S acts on the tire grounding point G from outside to the inside, the braking force B acts on the grounding point G from the front to the rear, and the engine braking force E acts on the wheel center W from the front to the rear. The driving force K acts on the wheel center w from the rear to the front. When tire lateral force S acts during cornering, etc., a rotational moment is generated around the L axis in a counterclockwise direction when viewed from above, and the rubber bushes 19, 20
Due to the elasticity of the wheel hub 18, the wheel hub 18 is displaced around the ball joint 21 in the toe-in direction. At this time, if the elasticity of the front rubber bushing 20 is made larger than the elasticity of the rear rubber bushing 19, an even greater toe-in effect can be obtained. At the same time, due to a bump on one side during cornering, a stabilizing reaction force F from the stabilizer 23 acts diagonally downward and outward on the rear end of the arm 22 of the wheel hub 18 via the control rod 24. The vertical component VF of the stabilizer reaction force F causes the wheel hub 18 to rotate clockwise (as viewed from the left) around the ball joint 21, and the rear is displaced outward due to the horizontal component HF of the stabilizer reaction force F. . This clockwise rotation causes the front side of the wheel hub 18 to be displaced inwardly and the rear side to be outwardly due to the orientation of the axes of the rubber bushes 19 and 20, and as a result, the wheel hub 18 is displaced in the toe-in direction. Further, due to the outward action of the horizontal component force HF, the wheel hub 18 similarly receives a force in the toe-in direction, and is effectively displaced in the toe-in direction. In this way, during cornering, both the lateral force S and the stabilizing reaction force F produce a toe-in effect, making it possible to effectively toe-in the tire. Next, brake force B, engine brake force E,
The toe-in effect due to the driving force K will be explained. When the brake force B acts on the grounding point G from front to back, the grounding point G is located at the ball joint 2 in the illustrated example.
1 and the rubber bushes 19 and 20, the wheel hub 18 is rotationally displaced around the ball joint 21 (around the L axis) in the counterclockwise direction, that is, in the toe-in direction T when viewed from above.
On the other hand, this braking force B has the effect of attempting to rotate the wheel hub 18 counterclockwise (as viewed from the left side) around the M axis. As a result, the wheel hub 18 tends to be displaced in the toe-out direction. At this time, if the action of the braking force B around the L axis is larger, there is no problem because a toe-in effect can be obtained after all, but since it is not always possible to design it in this way, the rubber bushes 19, 2
By providing a stopper on the rear side of one of the wheels, toe-in can be ensured. When the engine braking force E acts on the wheel center w from front to back, the engine braking force E is applied around the L axis because the wheel center w is located inside the plane p that includes the ball joint 21 and the rubber bushes 19 and 20. acts in the toe-in direction. However, at this time, since the tire 12 simultaneously tries to rotate counterclockwise around the M axis, the rubber bush 1
The wheel hub 18 tends to be displaced in the toe-out direction depending on the orientation of the wheels 9 and 20. However, toe-out is prevented by the action of the stopper provided on the rear side of either one of the rubber bushes 19, 20, and around the line connecting the ball joint 21 and the rubber bush with the stopper provided at the rear. displacement is possible only in the toe-in direction. When the driving force K acts on the wheel center W from the rear to the front, this is a force in the opposite direction to the engine braking force E, so the wheel hub 18 has a toe-out tendency around the L axis, a clockwise rotation around the M axis, and a rubber bushing. As a result of the comprehensive effect of the toe-in tendency due to the orientations 19 and 20, toe-in is attempted.
In addition, in this case, by providing a stopper to restrict rotational displacement in the counterclockwise direction around the M-axis after either one of the rubber bushes 19, 20, rotational displacement around the L-axis can be more reliably achieved. The wheel hub 18 can be displaced in the toe-in direction around the line connecting the toe-in points 21. The arrangement of the ball joint 21 and the two rubber bushes 19, 20 in FIG. 2 is shown in FIG. 3, and examples of different arrangements are shown in FIGS. 4 and 5. In FIG. 3, the ball joint 21 is placed in the first quadrant, the rubber bush 20 is placed in the third quadrant, and the rubber bush 19 is placed in the fourth quadrant. As explained above. In Figure 4, the ball joint 21 is also the first
It is arranged in a quadrant, and the rear rubber bush 1
9 is also placed in the fourth quadrant as in FIG. 3, but the other rubber bushes 20 are placed in the second quadrant. In this case, the rubber bushing 20 disposed in the second quadrant is oriented downwardly and outwardly so as to guide the clockwise rotation of the wheel hub inwardly.
It is oriented upward and inward. The rear rubber bushing 19 is rearwardly inward and displaces clockwise rotation of the wheel hub later and outwardly. In the arrangement shown in FIG. 4 as well, the toe-in effect with respect to the four external forces and stabilizer reaction force is the same as in the case shown in FIG. 3. In other words, in response to lateral force S, the rubber bushing changes toe-in by displacing counterclockwise around the L-axis when viewed from above, and in response to stabilizer reaction force and driving force K, it rotates clockwise around the M-axis. 19,
20 is guided in the toe-in direction, and in response to brake force B and engine brake force E, the toe-in changes by displacing counterclockwise around the L axis when viewed from above. In FIG. 5, the ball joint 21 is placed in the second quadrant, and the two rubber bushes 19, 2
0 is placed in the fourth and first quadrants. Both rubber bushes are oriented upwards, downwards and outwards. This is to displace the clockwise rotation around the ball joint 21 outward from the rear of the wheel center w, thereby changing the toe-in.
Ball joint 21 and rubber bush 19,2
The plane P including 0 is located outward from the wheel center w and is a plane perpendicular to the ground. The arrangement shown in FIG. 5 also provides a toe-in effect against the four external forces and the stabilizer reaction force. That is,
The stabilizer reaction force (acting downward and outward behind the ball joint 21) consists of an outward horizontal component force and a downward force that rotates the wheel hub clockwise around the M axis of the ball joint 21. The wheel hub is displaced in the toe-in direction by the vertical force and the action of the rubber bushes 19, 20 which guide the rotation outwardly at the rear.
The driving force K also causes clockwise rotation around the M axis, causing a toe-in change. Brake force B and engine brake force E are at the wheel center w
is ball joint 21 and rubber bush 19,
Since the wheel hub is located inside the plane p including 20, an attempt is made to displace the wheel hub in the toe-in direction, but at this time, the wheel hub rotates counterclockwise at the same time and is also guided in the toe-out direction. A stopper is provided on the upper side of the lower rubber bushing 19 (on the rear side when the rubber bushing 19 is oriented horizontally) to prevent rotation in the counterclockwise direction. This causes the wheel hub to be displaced only in the toe-in direction. In response to the lateral force S, the rubber bushings 19 and 20 tend to move in the toe-out direction around the ball joint 21, so it is desirable to make the inside of the rubber bushes 19 and 20 hard so that they do not move in the toe-out direction. When this lateral force S acts, the outer tire is bumped and a stabilizing reaction force is often applied, so as mentioned above, toe-in changes due to the stabilizing reaction force occur at the same time, resulting in a toe-in effect. As is clear from the detailed description of the above embodiments,
According to the present invention, it is possible to toe-in the tire when any of the four external forces, lateral force S, brake force B, engine brake force E, and driving force K, is applied, and also toe-in the tire on one side due to cornering etc. It is possible to obtain a rear suspension that has the effect of toe-in the tire on the bumped side even when bumping by the vertical component VF and horizontal component HF of the stabilizing reaction force F. 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. Further, 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, an example in which the present invention is applied to a semi-trailing type rear suspension will be described in Sections 6A+6B.
This will be explained using diagram +6C. Figure 6A is a view of the right rear wheel viewed from above, Figure 6B is a side view of it viewed from the right outside (the tires are shown with phantom lines), and Figure 6C is a side view of the right rear wheel viewed from above.
The figure is a view of FIG. 6A viewed from the left. Two arms 30A, 3 extending forward in a bifurcated shape
The front end of each arm 30A, 30B of the semi-trailing arm 30 having 0B is attached to a shaft support 31 on the vehicle body.
A and 31B, and the wheel hub 32 is supported by the ball joint 33, the first rubber bush 34, and the second rubber bush 34 on the outside of the rear main body 30C.
It is supported via a rubber bushing 35. The wheel hub 32 also has an arm 32 extending rearward.
A is integrally provided, and an arm 32B extending further upward is connected to the rear end of this arm 32A,
Control rod 3 is attached to the upper end of this arm 32B.
6 is connected to the control rod 3.
The upper end of the stabilizer 6 is connected to the front end of a forward bent portion 38A of a stabilizer 38 supported by a bracket 37 on the vehicle body. In this configuration, the arrangement of the front rubber bushing, that is, the second rubber bushing 35 and the wheel hub 1
arm 32 between 8 and control rod 36
Except for the shapes of A and 32B, the arrangement of all other members is the same as in the embodiment shown in FIG. The second rubber bush 35 is higher than the first rubber bush 34 and is in the third quadrant (the definition of the quadrant is the same as above).
3B, and is arranged upwardly and inwardly so as to guide inward the rotation of the wheel hub 32 in the clockwise direction (as viewed from the left, that is, when viewed from the direction opposite to that in FIG. 3B) due to the stabilizer reaction force. ing. The actions on the vertical and horizontal components of 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. 2, 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 perspective view showing an example in which the present invention is applied to a strut type twin link suspension;
Figure 2 is a principle diagram showing the main parts in detail, showing a perspective view of the right rear wheel seen from the rear left and its three-way projection view, and Figure 3 shows the ball joint and rubber bushing shown in Figure 2. Figures 4 and 5 are principle diagrams showing other examples of the arrangement of ball joints and rubber bushings, and Figure 6A is an example of applying the present invention to a semi-trailing type rear suspension. A partially cutaway top view of the right rear wheel shown,
FIG. 6B is a side view of the example shown in FIG. 6A, looking through the tire from the right outside, and FIG. 6C is a view of FIG. 6A seen from the left. 12... Tire, 14... Lateral link, 1
8, 32...Wheel hub, 19, 20, 34,
35... Rubber bush, 21, 33... Ball joint, 22, 32A, 32B... Arm,
23, 38... Stabilizer, 24, 36... Control rod, 30... Semi-trailing arm.

Claims (1)

[Claims] 1. A swinging member whose one end is swingably supported on a vehicle body;
A wheel support member is supported at three points on this swinging member via a ball joint and two rubber bushes, and rotatably supports the wheel, and a stabilizer control rod that transmits stabilizer reaction force is connected to this wheel support member. The stabilizer comprises connected stabilizers, the ball joint is disposed above the wheel center, at least one of the two rubber bushes is disposed below the wheel center, and includes the two rubber bushes and the ball joint. The surface of the rubber bushing is located at the height of the wheel center on a vertical plane including the wheel center axis, outward from the vehicle body from the left and right center of the wheel, and outward from the vehicle body on the ground, and the shaft of the rubber bush is located at the vehicle body around the ball joint of the wheel support member. The control rod is arranged so as to guide clockwise rotation inwardly in front of the wheel center when viewed from the left side, and the control rod is arranged to be inclined downwardly and outwardly, and is connected to the wheel support member behind the ball joint. An automobile rear suspension characterized by being connected.