JPH04331622A - Suspension device for vehicle - Google Patents

Abstract

PURPOSE:To change the camber characteristic, secure the straight advance stability of a vehicle, and improve the turning performance by changing the connection point between a suspension member and an upper control arm in response to the lateral force applied to wheels. CONSTITUTION:The first and second suspension members 5, 4 are supported on a vehicle body 7 with support pins 6, the rigidity of insulators 15 is made lower than that of insulators 14, both suspension members 5, 4 are connected by connecting members 2, 3, the turning outside of the first suspension member 5 is moved downward by the lateral force when a vehicle is turned, the connection point to an upper control arm is moved downward, the camber angle change against the vehicle body 7 on the turning outside is increased, and the camber angle change against the ground is moved to the negative direction.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension system for a vehicle.

0002

2. Description of the Related Art A conventional suspension device for a vehicle is disclosed, for example, in Japanese Patent Application Laid-Open No. 135314/1983. This is a double wishbone type vehicle suspension system, and a front view is shown in FIG.

As shown in FIG. 6, a wheel support member 8 that rotatably supports a wheel 9 is connected to an upper control arm 1.
1. The lower control arm 12 is attached to the vehicle body 7 so that it can swing in the vertical direction. That is, the upper control arm 11 is connected to the wheel support member 8 at its outer end, and connected to the vehicle body 7 at its inner end so as to be able to swing in the vertical direction of the vehicle body 7. Further, the lower control arm 12 located below the upper control arm 11 is also connected at its outer end to the lower end of the wheel support member 8, and its inner end is connected to the vehicle body 7 so that it can swing in the vertical direction of the vehicle body 7. It is connected to a supported suspension member 19.

Depending on the length and mounting position of the upper control arm 11 and lower control arm 12,
The angle with respect to the road surface accompanying the vertical movement of the wheel 9, that is, the camber angle of the wheel relative to the ground is determined. Figure 7 shows the camber angle φ for the wheels.
A front view and a plan view are shown showing the state in which the mark is attached. That is, when the wheel freely rolls in a horizontal plane, it forms an arc BB' centered on point O. In other words, the wheel draws a circle with radius R/sinφ (R is the radius of the wheel) centering on point O. Therefore, if a wheel with a camber angle is forced to move linearly without being allowed to make this circular turn, a force (canvas thrust) is generated in the wheel toward the camber angle.

That is, when the camber angle changes significantly due to the up and down movement of one wheel due to unevenness of the road surface, canvas thrust acts strongly, causing the vehicle to wobble when traveling straight. That is, since this has an undesirable effect on steering stability, conventional vehicle suspensions have been designed to minimize changes in the ground camber angle due to the vertical movement of the wheels.

[0006]

[Problems to be Solved by the Invention] However, in conventional vehicle suspension systems, when the vehicle performs a turning motion, the vehicle body tilts toward the outside of the turn due to centrifugal force, resulting in a roll angle (tilt angle) between the vehicle body and the road surface. occurs. This roll angle increases the ground camber angle of the wheel in the outward (positive) direction of the turn. For this reason, the canvas thrust works toward the outside of the rotation.

FIG. 8 is a rear view schematically showing the relationship between the vehicle body and wheels when a conventional vehicle turns leftward. That is, when the vehicle turns to the left, centrifugal force acts to the right of the vehicle, and the centrifugal force causes the vehicle body to roll to the right. At this time, due to the inclination angle with respect to the road surface, that is, the roll angle, the ground camber angle of the right wheel of the vehicle shifts to the positive side. For this reason, the canvas thrust works toward the right side of the vehicle. Normally, when a vehicle turns, turning performance is affected by the friction between the road surface and the tires, especially the friction between the tires on the outside of the turn, where the vehicle's load is large, and the road surface, which causes a lateral force that acts on the inside of the turn, and a centrifugal force that acts on the outside of the turn. It is determined by the difference between the turning lateral force and the centrifugal force. However, since the canvas thrust acts in the same direction as the centrifugal force, that is, toward the outside of the turn, there is a problem in that the turning performance deteriorates. In view of this, the present invention sets the ground camber angle of the wheels to be minimized when the vehicle is traveling straight, and sets the ground camber angle to be more negative than before, especially for the wheels on the outside of the turn when the vehicle is turning. The object of the present invention is to provide a possible suspension device.

[0008]

[Means for Solving the Problems] In order to achieve this object, the invention as set forth in claim 1 provides a suspension member supported by a vehicle body via an insulator;
A wheel support member rotatably supports the wheels located on the left and right sides of the vehicle body, and the upper and lower ends of the wheel support member are connected by an upper control arm and a lower control arm, respectively, so that the wheel support member can swing in the vertical direction of the vehicle body. In a suspension device connected to a suspension member, the suspension member includes a first suspension member and a second suspension member arranged above and below, the upper control arm is connected to the first suspension member, and A lower control arm is connected to the second suspension member, and the rigidity in the vehicle body vertical direction of an insulator interposed between the first suspension member and the vehicle body is determined by the second suspension member.
The rigidity in the vertical direction of the vehicle body of an insulator interposed between the suspension member and the vehicle body is lower than that, one end is connected to the right side of the center of the vehicle body of the first suspension member, and the other end is connected to the vehicle body of the second suspension member. A first connecting member connected to the left side of the center, and one end connected to the first connecting member.
The suspension member is connected to the left side of the center of the vehicle body,
A second connecting member whose other end is connected to the right side of the second suspension member from the center of the vehicle body is provided.

[0009]

[Operation] When the vehicle travels straight, the wheels move up and down due to changes in the camber angle relative to the ground determined by the lengths and mounting positions of the upper and lower control arms.

When a vehicle turns, centrifugal force and turning lateral force generated by friction between the road surface and the tires act as described below.

FIG. 3 is a rear view schematically showing the effect of force applied to the suspension device when the vehicle to which the present invention is applied turns to the left. At this time, the first suspension member 5 receives a force toward the outside of the turn (to the right in the figure), and the second suspension member 4 receives a force to the inside of the turn (to the left in the figure). Due to a portion of the force acting on the first suspension member 5 and the second suspension member 4, the first connecting member 3 receives a tensile force, and the second connecting member 2 receives a compressive force.

Therefore, due to the combination of the above forces, the connection point 5a between the first suspension member 5 and the first connection member 3
A substantially downward force E is applied to the connection point 5b between the first suspension member 5 and the second connection member 3, and a substantially upward force F is applied to the connection point 5b between the second suspension member 4 and the first connection member 3.
A substantially upward force G is applied to the connection point 4a between the second suspension member 4 and the second connection member 2, and the second suspension member 4 and the second connection member 2
A substantially downward force H is applied to the connection point 4b.

[0013] Due to the above forces E, F, G, and H, the vertical stiffness of the insulator interposed between the second suspension member and the vehicle body causes the insulator interposed between the first suspension member and the vehicle body to Due to the low rigidity, the vehicle left side portion of the first suspension member moves upward, and the vehicle right side portion moves downward, in a trajectory regulated by the lengths and connection points of the first and second connection members, and the second suspension member moves upward. Due to the relative movement with respect to the member, the connection point between the upper control arm on the outside of turning (on the right side in the figure) and the first suspension member moves downward. Therefore, when the right wheel moves upward relative to the vehicle body due to the roll of the vehicle body, the connection point between the upper control arm and the wheel support member (not shown) is pulled into the vehicle (left side in the diagram), compared to the conventional The wheel's camber angle to the ground increases toward the negative side.

On the other hand, when the vehicle turns to the right,
The vehicle left side portion of the first suspension member is directed downward;
Since the right side of the vehicle moves upward relative to the second suspension member on a trajectory regulated by the lengths and connection points of the first and second connecting members, the upper part on the outside of the turn (left side in the figure) The connection point between the control arm and the first suspension member moves downward. Therefore, when the left wheel moves upward relative to the vehicle body due to the roll of the vehicle body, the connection point between the upper control arm and the wheel support member (not shown) is pulled into the vehicle interior (right side in the diagram), Compared to this, the camber angle of the wheels toward the ground on the negative side increases.

[0015]

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings.

1 to 5 show a first embodiment of the present invention.

FIG. 1 is a rear view showing the entire suspension device to which the present invention is applied. As shown in FIG. 1, wheels 9 and wheel support members 8 that rotatably support the wheels 9 are arranged on both the left and right sides of the vehicle body 7, and are supported at the lower part of the vehicle body 7 on both the left and right sides of the vehicle body 7 and inwardly from the wheels 9. Fix pin 6 (vehicle body). The support pin 6 supports the first suspension member 5 and the second suspension member 4 located below the first suspension member through an insulator (not shown). One end of the first connecting member 3 is connected to the right side of the vehicle body 7 of the first suspension member 5.
The other end of the first connecting member 3 is connected to the left side of the vehicle body 7 of the second suspension member 2 so as to have a pivot axis in the longitudinal direction. do. One end of a second connecting member 2 is connected to the left side of the vehicle body 7 of the first suspension member 5 so as to have a swing axis in the longitudinal direction of the vehicle body 7, and the other end of the second connecting member 2 is connected to the left side of the vehicle body 7. The second suspension member 4 is connected to the right side of the vehicle body 7 so as to have a swing axis in the longitudinal direction of the vehicle body 7.

Further, the inner end of an upper control arm 11 is swingably supported on both left and right sides of the first suspension member 5, and the outer end of the upper control arm 11 is swingably supported on the upper end of the wheel support member 8. support. The inner end of a lower control arm 12 is swingably supported on both left and right sides of the second suspension member 4, and the outer end of the lower control arm 12 is swingably supported on the lower end of the wheel support member 8. Here upper control arm 1
1 and the lower control arm 12 have substantially the same length and are substantially parallel.

In order to absorb the vertical movement of the wheel 9, the upper end of the spring/shock absorber 30 is swingably supported on the vehicle body 7, and the spring/shock absorber 3
The lower end of the wheel support member 8 is swingably supported at the lower end of the wheel support member 8.

FIG. 2 shows a cross-sectional rear view of the suspension member shown in FIG. That is, the vertical stiffness k1 of the insulator 15 interposed between the support pin 6 and the first suspension member 5, and the vertical stiffness k1 of the insulator 14 interposed between the support pin 6 and the second suspension member 4. The relationship with k2 is k1 < k2. In addition, the upper control arm 11 on the right side of the vehicle body 7 and the
The connecting members 3 are substantially parallel, and the upper control arm 11 on the left side of the vehicle body 7 and the second connecting member 2 are substantially parallel. Therefore, when the second suspension member 4 is fixed, the trajectory drawn by the supporting portion of the upper control arm 11 of the first suspension member 5 is different from the trajectory drawn by the inner end when the outer end of the upper control arm is centered. do not intersect.

With the above configuration, when no force is applied to the wheels 9 in the lateral direction of the vehicle body, the positional relationship between the first suspension member 5 and the second suspension member 4 does not change as shown in FIG. Since the inclination angle between the vehicle body 7 and the road surface is also 0, when the wheels 9 move up and down, the change in the camber angle with the road surface is determined by the lengths and mounting positions of the upper control arm 11 and lower control arm 12.

FIG. 3 is a rear view schematically showing the effect of force applied to the suspension device when a vehicle to which the present invention is applied turns leftward.

That is, when a lateral force is applied to the wheel 9 in the left direction of the vehicle body when turning, the lateral force passes through the lower control arm 12 and causes the second suspension member 4 to move toward the inside of the turn (left side in the figure). This becomes a pushing force, which becomes forces I and J in the leftward direction of the vehicle body at the connection points 4a and 4b between the second suspension member 4, the first connection member, and the second connection member. On the other hand, the above-mentioned lateral force becomes a force that pushes the first suspension member 5 toward the outside of the turn (to the right in the figure) via the upper control arm 11, and this forces the first suspension member 5, the first connecting member, and the second At the connection points 5a and 5b with the connection members, forces K and L are applied in the rightward direction of the vehicle body.

Part of the force pushing the first suspension member 5 toward the right side of the vehicle is a force A in the upper right direction of the vehicle at the connection point 4a between the second suspension member 4 and the first connection member 3. Become. Furthermore, at the connection point 4b between the second suspension member 4 and the second connection member 2, a force B is generated in the lower right direction of the vehicle.

On the other hand, the second suspension member 4
A part of the force pushing the vehicle toward the left side becomes a force C toward the lower left of the vehicle at the connection point 5a between the first suspension member 5 and the first connection member 3. Further, at the connection point 5b between the first suspension member 5 and the second connection member 2, a force D is generated in the upper left direction of the vehicle.

As a result, the first suspension member 5
At the connection point 5a between the first connection member 3 and the first connection member 3, a force E is applied substantially downward to the vehicle as a result of the combination of the force K in the right direction of the vehicle and the force C in the lower left direction of the vehicle. At the connection point 5b between the first suspension member 5 and the second connection member 2, the force L in the right direction of the vehicle and the force D in the upper left direction of the vehicle are combined to form a force F in the generally upward direction of the vehicle. At the connection point 4a between the second suspension member 4 and the first connection member 3, the force I in the left direction of the vehicle and the force A in the upper right direction of the vehicle are combined to form a force G in the generally upward direction of the vehicle. Second suspension member 4
At the connection point 4b between the second connection member 2 and the second connection member 2, a force H in a substantially downward direction of the vehicle is applied by combining a force J in the left direction of the vehicle and a force B in the right downward direction of the vehicle.

Therefore, the vertical rigidity of the insulator 14 interposed between the second suspension member 4 and the support pin 6 increases the vertical rigidity of the insulator 15 interposed between the first suspension member 5 and the support pin 6. Since the rigidity in the direction is low, the vehicle left side portion of the first suspension member 5 is directed upward, the vehicle right side portion is directed downward, and the lengths of the first and second connecting members 3 and 2 and the connecting points 4a, 4b, 5
It moves relative to the second suspension member 4 along a trajectory regulated by a and 5b.

FIG. 4 shows a rear view schematically illustrating the state in which each suspension member 4, 5 has moved. The connection point 11a between the upper control arm 11 and the first suspension member 5 on the right side of the vehicle moves downward, and the connection point 11c between the upper control arm 11 and the first suspension member 5 on the left side of the vehicle moves upward. At this time, the first connecting member and the upper control arm 1 on the right side of the vehicle
1 are substantially parallel, the connection point 11 between the first suspension member 5 and the upper control arm 11
Since the trajectory drawn by a does not intersect with the trajectory drawn by the connection point 11a when the center is the outer end 11b of the upper control arm 11, the connection point 11b between the upper control arm and the wheel support member 8 is actually You will be drawn inside. Then, due to the roll, the wheels 9 are moved to the vehicle body 7.
When the vehicle approaches , the connection point 11b is pulled further inside the vehicle than when the vehicle is traveling straight.

[0029] Above, the case where the vehicle turns to the left has been explained, but when the vehicle turns to the right,
The connection point 11c between the upper control arm 11 and the first suspension member 5 on the left side of the vehicle moves downward, and the connection point 11a between the upper control arm 11 and the first suspension member 5 on the right side of the vehicle moves upward. At this time, the connection point 11d is drawn inward of the vehicle, and when the wheel 9 approaches the vehicle body 7 due to the roll, the connection point 11d is further drawn into the inside of the vehicle compared to when the vehicle is traveling straight.

FIG. 5 is a graph showing changes in the camber angle of the wheels relative to the vehicle body in the conventional suspension system and changes in the camber angle of the wheels relative to the vehicle body in the suspension system using the present embodiment. That is, even if the change in the camber angle relative to the vehicle body due to the vertical movement of the wheels in this embodiment is set to be small as in the conventional case, when the vehicle turns, the connection point between the first suspension member 5 on the outside of the turn and the upper control arm 11. is lowered below the vehicle, the change in the camber angle relative to the vehicle body due to the vertical movement of the wheel increases in the negative direction. For this reason, even if a roll angle occurs in the vehicle body, the camber angle of the wheels relative to the ground can be prevented from increasing toward the positive side compared to conventional systems, and conversely, it can be changed toward the negative side.

[0031]

As explained above, in the vehicle suspension device according to the present invention, the suspension members are composed of a first suspension member and a second suspension member arranged vertically, and the upper control arm is supported on a first suspension member, the lower control arm is supported on a second suspension member so as to be able to swing vertically, and an insulator interposed between the first suspension member and the vehicle body is supported in the vertical direction of the vehicle body. The rigidity is lower than the rigidity in the vertical direction of the vehicle body of an insulator interposed between the second suspension member and the vehicle body, and one end is connected to the right side of the center of the vehicle body of the first suspension member, and the other end is connected to the first suspension member to the right of the center of the vehicle body. 2
a first connecting member connected to the left side of the vehicle body center of the suspension member; one end connected to the left side of the vehicle body center of the first suspension member, and the other end connected to the right side of the vehicle body center of the second suspension member; The second connected
Because of the provision of the connecting member, when the vehicle is traveling straight, the wheels move up and down due to changes in the ground camber angle determined by the lengths and mounting positions of the upper and lower control arms, but when the vehicle is turning, Since both ends of the first suspension member move upward on the inside of the turn and downward on the outside of the turn, the connection point between the first suspension member on the outside of the turn and the upper control arm moves downwards of the vehicle, causing the vehicle to roll. It is possible to change the camber angle of the outer wheel to the negative side compared to the conventional case. Therefore, the turning performance of the vehicle can be improved without impairing the stability when traveling straight.

[Brief explanation of drawings]

FIG. 1 is a rear view showing the entire suspension device to which the present invention is applied.

FIG. 2 is a rear view showing a cross section of the suspension member in FIG. 1;

FIG. 3 is a rear view schematically showing the forces applied to each suspension member when the vehicle turns.

FIG. 4 is a rear view schematically showing the movement of each suspension member when the vehicle turns.

FIG. 5 is a graph showing changes in camber angle when traveling straight and changes in camber angle when turning.

FIG. 6 is a front view showing a conventional suspension device.

FIG. 7 is a front view and a plan view showing the relationship between the camber angle of the wheel and the canvas last.

FIG. 8 is a rear view schematically showing a rolling state of the vehicle when turning.

[Explanation of symbols]

2... Second connection member, 3... First connection member, 4... Second suspension member, 5... First suspension member, 6... Support pin (vehicle body), 7... Vehicle body, 8... Wheel support member, 9...wheels, 11 upper control arm, 12...
Lower control arm.

Claims (1)

[Claims] 1. A suspension member supported by a vehicle body via an insulator, a wheel support member rotatably supporting wheels located on the left and right sides of the vehicle body, and a wheel support member capable of swinging in the vertical direction of the vehicle body. In the suspension device in which the upper end and the lower end are connected to the suspension member by an upper control arm and a lower control arm, respectively, the suspension member is composed of a first suspension member and a second suspension member arranged above and below. The upper control arm is connected to the first suspension member, the lower control arm is connected to the second suspension member, and the insulator interposed between the first suspension member and the vehicle body is connected to the upper and lower parts of the vehicle body. The rigidity in this direction is lower than the rigidity in the vertical direction of the vehicle body of an insulator interposed between the second suspension member and the vehicle body, one end is connected to the right side of the center of the vehicle body of the first suspension member, and the other end is connected to the first suspension member to the right of the center of the vehicle body. a first connecting member connected to the left side of the vehicle body center of the second suspension member; one end connected to the left side of the vehicle body center of the first suspension member; the other end connected to the left side of the vehicle body center of the second suspension member; a second connecting member connected to the right side;
A vehicle suspension device characterized by being provided with.