JPS58221706A - Automotive rear suspension - Google Patents

Abstract

PURPOSE:To improve the steerability by specifically setting up the joint position of a swingable member and a wheel supporting member by means of a ball joint and a resilient bush to make float engagement thereof so as to let a spring reaction force act on the wheel supporting part. CONSTITUTION:Float engagement between a wheel hub and a semi trailing arm is made by a ball joint P which is swingable about one point and by rubber bushes R1 and R2. At the same time a coil spring 7 is disposed between a car body and the wheel hub. When a wheel 4 is looked from the left side of the car body, the ball joint P, the bush R1 and the bush R2 are arranged in the fourth, the first and the second quadrant, respectively in the X-Z axes coordinates with its origin located at the wheel center, and the axis centers of R1 and R2 are inclined internally and externally in the rear of the car body respectively. Moments about L-axis and M-axis are produced by a lateral force and a bumping load to vary toe-in, thereby stabilizing the steerability.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rear suspension installed on an automobile, and particularly to one 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) toward the turning center and a bump load act on the left and right wheels, especially the wheels on the outside of the turning center. It is known that changing the toe-in of the wheels so that they face inward with respect to the traveling direction is preferable in order to prevent oversteering and improve steering stability.

Conventionally, a rear suspension arm that changes the toe-in of a wheel in response to such a lateral force is designed to connect at least one end between a rear suspension arm, whose one end is swingably supported on the vehicle body, and a wheel hub, which rotatably supports the wheel. The front and rear parts are float-coupled, and the front part is connected with a spring and the rear part is connected with a pin (West German Patent No. 2158931), and the characteristics of the front spring are gradually adjusted according to the lateral force. (West German Patent No. 2355954), or the front and rear rubber bushings are joined together and the front rubber bushing is softer than the rear rubber bushing (Special Publication Publication No. 52-3'7).
No. 649) has been proposed.

However, in all of the above-mentioned conventional devices, the toe-in effect against the lateral force cannot be effectively exerted because the lateral force is simply displaced in the toe-in direction of the spring or the rubber bush. Moreover, it was naturally impossible to expect a toe-in effect against the bump load acting on the wheel during turning.

In view of this, the present invention provides a ball joint and at least one elastic member between a rocking member as a rear suspension component such as the rear suspension arm and a wheel support member that rotatably supports a wheel. The body bushings are float-coupled, and each coupling part is appropriately positioned relative to the center of the wheel, and the spring reaction force of the spring unit that functions as a damper in the rear suspension is used to properly connect the wheel support member to the wheel support member. The purpose of this is to improve steering stability by making it possible to reliably change the toe-in of the wheel against lateral force and bump load.

In order to achieve this object, the present invention has a structure in which a swinging member whose one end is swingably supported on a vehicle body, a wheel support member rotatably supporting a wheel, and a combination of the wheel support member and the swinging member are provided. at least one elastic bushing that connects the wheel support member and the swinging member; an upper end connected to the vehicle body and a lower end connected to the wheel support member; and a spring unit connected to the ball joint. Second. The elastic bushing is located in one of the fourth quadrants, and the elastic bushing is located in any of the remaining three quadrants excluding the quadrant in which the ball joint is located, and the elastic bushing is The spring unit is arranged so that the direction of deformation is restricted to the toe-in direction, and the spring unit is mounted at a position forward of the ball joint connection point of the wheel support member.

As a result, the wheel support member is rotationally displaced in the toe-in direction around the ball joint in response to a lateral force, changing the wheel toe-in, and the wheel support member is rotated in response to a bump load by the downward spring reaction of the spring unit. The toe-in of the wheel is changed by rotationally displacing the wheel in the toe-in direction by force.

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

FIG. 1 shows a semi-trailing arm according to the present invention as a swinging member extending in the longitudinal direction of the vehicle body, and one end of the semi-trailing arm 1, that is, the forked front end is It is swingably supported by a sub-frame 2 as a vehicle body component disposed in the left-right direction of the vehicle body. The wheel knob is a wheel support member that rotatably supports the wheel 4, and the wheel 4 has one end connected to a differential 5 and the other end of a drive shaft 6 connected to the wheel 4. Further, reference numeral 7 denotes a spring unit consisting of a pump spring 7a and a coil spring 7b.
The upper end of the wheel is connected to the vehicle body, and the lower end is connected to the wheel no. Note that 8 is a stabilizer.

As shown in FIG. 4, which will be described later, between the wheel pro and the semi-trailing arm 1, there is a ball joint P that can swing freely around one point, and two first and the second elastic bushing R1 and the horse. second elastic bush R,
, R2 and the arrangement structure of 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 rear suspension 7. Reference numeral 10 denotes a connecting hub as a swinging member, and the connecting hub 10 is a two-stooth structure extending in the left-right direction of the vehicle body. It is swingably supported by sub-frames 12 and 15, which are vehicle body structural members, which are disposed front and rear in the left-right direction of the vehicle body via two-type suspension arms 11, 11.

Between the connecting hub 10 and a wheel hub 15 as a wheel support member that rotatably supports the wheel 14,
As in the first embodiment, they are connected by a pole joint P and first and second elastic bushes R1. 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 FIG. 2, 17 is a stabilizer, 18 is a differential, and 19 is a drive shaft.

Furthermore, FIG. 3 shows the present invention as shown in FIG.
20 is a rear axle tube as a swinging member extending in the left-right direction of the vehicle body and into which a rear axle provided separately from the drive shaft 21 is inserted; 20 is swingably supported by the vehicle body via two left and right tension/jin rods 22° 22 extending in the longitudinal direction of the vehicle body.

Similarly, between the end of the rear axle tube 20 and the wheel hub 24 as a wheel support member that rotatably supports the wheel 25, there is a pole joint P and first and second elastic bushes R, . The wheel knob 24 is connected to the lower end of a spring unit 25 whose upper end is connected to the vehicle body. In addition, in FIG. 3, 26 extends in the longitudinal direction of the vehicle body and is connected to the rear axle pipe 2.
The plate on which the 0 is mounted is sprung, and the front end is rotatably connected to the vehicle body via an eye 27 and the rear end via a shackle 28. Further, 29 is a differential.

The pole joint P in the first to third embodiments and the first. The arrangement of the second elastic body bush R1° and the arrangement of the spring unit 7 (16°25) will be explained with reference to FIG.

Fig. 4 is a view of the wheel 4 (14, 2'5) on the rear right side of the vehicle body, viewed from the left side (inside) of the vehicle body, and is a horizontal view (Y axis) of the wheel center 0 standard as seen from the left side of the vehicle body. In vertical (two-axis) coordinates, the pole joint P is located in the fourth quadrant, the first elastic bushing is located in the first quadrant, and the second elastic bushing is located in the second quadrant.

Further, the first elastic bush R1 is arranged so that its axis is inclined toward the rear inner side of the vehicle body, and the second elastic bush R1 is arranged so that its axis direction is inclined toward the rear outer side of the vehicle body. It is arranged in the direction. In addition, in FIG. 4, the horizontal and lateral Y-axes based on the wheel center 〇 are set for the above coordinates (X, Z) to create a rectangular coordinate system (X.

Y, Z) is constructed and the coordinate system (L, M,
N) is a coordinate system whose origin is the center of the pole joint P, which is obtained by translating the above coordinate system (X-, Y, Z).

Furthermore, the spring unit 7 (16, 25) is connected to the ball joint of the wheel knob 5 (15, 24).
It is attached at a position forward of the vehicle body from the P attachment point.

Therefore, the ball joint P, the first and second
A triangle that includes each attachment point of the elastic bushings R, R2 (the center of the pole joint P, the central point of each axis of the first and second elastic bushings R, R,) The mounting surface Q of and the YZ plane of the above coordinate system (X, Y, Z) (
At the intersection line q with the vertical plane (including the wheel center axis),
Assuming that the amount of offset from the wheel center 〇 in the Y-axis direction (wheel center axis) is W1, the offset amount on the wheel contact surface is G, and the amount toward the inner side of the wheel is a plus (+) amount, as shown in Figure 4. The above W is a negative (-) amount,
When G is a negative (-) amount, (a), the lateral force S acts in the +Y direction with respect to the wheel grounding point, so ΔPR
By acting as a moment force that rotates the mounting surface Q of R2 counterclockwise approximately around the L axis around the pole joint P, the mounting surface Q rotates around the L axis around the pole joint P in the toe-in direction. rotationally displaced, wheel 4
(14, 25) will change toe-in.

(b) Spring unit as a reaction force against bump load) 7 (16, 25) has a downward spring reaction force T
is generated, and the spring reaction force T is wheel knob 5 (15,
Since it acts at a position forward of the ball joint P in 24), the mounting surface Q is approximately M with the ball joint P as the center.
It acts as a moment force that rotates counterclockwise (forward rotation direction) around the axis, and rotates forward around the M axis around the mounting surface QFip. In this case, the axis of the first elastic bushing should be arranged inward toward the rear of the vehicle body, and the axis of the second elastic bushing should be arranged outward toward the rear of the vehicle body, and in general, the rigidity of the elastic bushing should be Since the mounting surface Q is lower in the direction than the direction perpendicular to the axis and has the property of being more easily deformed elastically in the direction of the axis, as the mounting surface Q is rotated forward about P, Due to the elastic deformation of the second elastic bushes R, R2, the rotation changes in the toe-in direction, and the wheel 4 (14° 25) changes in toe-in.

Further, in the case of this example, the toe-in effect is also obtained for other wheel acting forces (brake force B, engine braking force E, engine driving force K). That is, (C) Brake force B acts in the +X direction with respect to the wheel grounding point, so
The (-) amount of G acts as a moment force that rotates the mounting surface Q counterclockwise around the M-axis or L-axis around the ball joint P, so that the mounting surface Q rotates around the ball joint P in the counterclockwise direction. The wheel 4 (14, 25) is rotationally displaced in the toe-in direction, and the toe-in changes.

(d) Engine power (engine braking force) E acts in the +X direction with respect to wheel center 0, so W
By acting as a moment force that rotates the mounting surface Q counterclockwise approximately around the L axis with ball joint (ball joint) P as the center, the mounting surface Q moves in the toe-in direction with P as the center. Rotationally displaced, wheel 4 (1
4, 25) will change in toe-in.

At this time, in order to prevent clockwise rotation of the mounting surface Q around the M axis due to the engine braking force E, and to restrain the displacement of the first elastic bushing R1 in the first quadrant inward of the vehicle body, the bushing is It is desirable to provide a stopper at the rear end of R1.

(e) Since the engine driving force acts in the -X direction with respect to the wheel center 0, the (-) amount of W and the (-) amount of G
) by acting as a moment force that rotates the mounting surface Q in a counterclockwise direction approximately around the M axis with P as the center, as in the case of the spring reaction force T due to the bump load. The wheel 4 (14, 25
) toe-in change will be performed.

In addition, the above W is a positive (+) amount, and G is a negative (-) amount.
In the case of a lateral force S and a spring reaction force T due to a bump load, the same behavior characteristics as in (a) and (b) above are exhibited, and a toe-in effect is obtained.

In addition, in response to braking force B, the mounting surface Q rotates counterclockwise around the L axis, and in response to engine driving force K, it rotates counterclockwise around the L axis, producing a toe-in effect. However, in response to the engine braking force E, the mounting surface Q rotates clockwise around the M axis, and the toe-out changes contrary to the case of the spring reaction force T, and no toe-in effect can be obtained. .

Furthermore, when the above W and G are both positive (+) amounts, the lateral force S1 spring reaction force T and engine driving force K are Although a toe-in effect can be obtained for engine braking force E, a toe-in effect cannot be obtained for engine braking force E, and for braking force B, mounting surface Q rotates clockwise around the L axis and toe-out changes. Therefore, no toe-in effect can be obtained.

Moreover, FIG. 5 shows a modification of the arrangement structure of the ball joint P and the first and second elastic bushes R1, R2, in which the ball joint 1-p is located at the coordinates (X, Z) C1 in the first quadrant. and position the first and second elastic bushings R1, R, in the third and fourth quadrants, respectively, and align the axis of the first elastic bushing in the third quadrant toward the rear and inward of the vehicle body. This is an example in which the axis of the second elastic bush R2 in four quadrants is arranged outward toward the rear of the vehicle body. In addition, the spring unit 7 (16, 25) is attached to the wheel hub 5 as shown in FIG.
It is attached at a position forward of the ball joint P (15, 24).

In this example, as shown in Fig. 5, if the offset amount W of the mounting surface Q of ΔPR1R2 on the wheel center axis is a plus (10) amount, and the offset amount G on the ground contact surface is a minus (-) amount, , (a)' For the lateral force S, the above mounting surface Q is
), the toe-in changes by rotationally displacing the ball joint y in the counterclockwise direction around the L axis around the ball joint P.

(b)' Spring unit 7 (1) due to bump load
6, 25) For the downward spring reaction force T, the mounting surface Q
As described in (b) above, the ball joint P is rotationally displaced around the M axis in the counterclockwise direction (forward rotational direction), and the first elastic bushing R1 is elastically deformed toward the vehicle interior and the second Toe-in changes due to the elastic deformation of the elastic bushings outwards from the vehicle body.

(C)' In response to braking force B, the mounting surface Q rotates counterclockwise around the M-axis or L-axis around the ball joint P as described in (C) above, causing a toe-in change. do.

(d)' In response to the engine braking force E, the mounting surface Q rotates counterclockwise around the M axis around the ball joint P, as in the case of the spring reaction force T due to the bump load. A toe-in effect can be obtained.

(e)' In response to the engine driving force K, the mounting surface Q rotates counterclockwise around the L axis around the ball joint P and changes in toe-in. At that time, the mounting surface QO
It is preferable to provide a stopper at the front end of the bushing in order to prevent clockwise rotation around the M-axis and to prevent the second elastic bushing in the fourth quadrant from moving inward into the vehicle body.

In addition, when the above W is a positive (+) amount and G is a positive (+) amount, the above ( It shows the same behavior characteristics as the cases of a)/, (b)', (a)' and (θ)', and a toe-in effect can be obtained.

Furthermore, in response to the player force B, the mounting surface Q is rotationally displaced around the M axis in a counterclockwise direction, and a toe-in effect is obtained as in the case of the spring reaction force T described above.

Furthermore, the above W is a negative (-) amount, and G is a negative (-) amount.
-), a toe-in effect is obtained with respect to the lateral force S and the spring reaction force T due to the bump load, as in the cases (a)' and (b)' above. Also, brake force B
For engine braking force E, the mounting surface Q rotates approximately counterclockwise around the L axis, and for engine braking force E, the mounting surface Q rotates approximately around the L axis due to a negative offset, producing a toe-in effect. In response to the driving force K, the mounting surface Q rotates approximately clockwise around the M axis, and the toe-out change occurs contrary to the case of the above-mentioned spring reaction force T, so that no toe-in effect is obtained.

Therefore, the ball joint P and the first
．． Due to the arrangement structure of the second elastic bushes R, R2 and the arrangement structure of the spring unit 7 (16, 25),
In response to the lateral force S and the bump load, the mounting surface Q rotates around the pole joint) P, and the wheel 4 (
14, 25) can be reliably performed,
Therefore, it is possible to prevent oversteering when turning or the like, and to significantly improve the steering stability of the vehicle.

Moreover, the mounting surface Q changes rotationally around the ball joint P in response to other forces B, engine braking force E, and engine driving force K acting on the wheel 4 (14, 25). Since it is possible to change the toe-in of 4 (14, 25), it is possible to further improve the steering stability.゛Also, ball joint P and 1st. By combining the second elastic bush R11R2 with a simple float connection and by using the existing spring unit 7 (16, 25), a toe-in effect can be obtained for the various wheel acting forces mentioned above. The rear suspension structure can be significantly simplified compared to the case where a toe-in mechanism is provided for the acting force.

Furthermore, the rotational displacement of the mounting surface Q is the ball joint P.
Since the action is centered on the wheel 4 relative to the acting force
Since the deviation of (14, 25) is small, the behavior toward toe-in changes is performed stably, and the toe-in effect can be made more reliable.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but also includes various other modifications. For example, in the above embodiment, an example is shown in which it is applied to a semi-trailing type, a strut type, and a dove ion type rear suspension, but the present invention is also applicable to various double link types such as a tissue bone type, or various types of swing arm type rear suspensions. It can also be applied to for example,
In the case of wishbone type, the upper and lower 2 extending in the left and right direction of the vehicle body
The connecting hub that connects the book arms 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 bushes R, R2.
At the same time, the spring unit may be attached to the wheel support member.

Further, the arrangement structure of the ball joint P and the first and second elastic bushes R, R2 can be arranged in various forms other than the examples shown in FIGS. 4 and 5, for example. Ball join) P in the second quadrant, the first and second
The elastic bushes R1 and R2 may be located in the third and fourth quadrants, and the point is to set the ball joint P at the coordinates (X,
1st degree and 2nd degree in Z). The first and second elastic bushes R1 and R2 may be located in two of the remaining three quadrants excluding the quadrant in which the ball joint P is located.

Further, it is sufficient that there is at least one elastic bushing, and the spring unit 7 (16, 2
5) The direction of elastic deformation is set so that when the mounting surface Q (wheel support member) is rotated forward about the ball joint P due to the downward spring reaction force T, the elastic deformation causes the change in the toe-in direction. If it is arranged so as to be restricted in the toe-in direction, the same effect as described above can be achieved.

Furthermore, in FIGS. 4 and 5, the description has been given of the right wheel at the rear of the vehicle body, but 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 rear suspension of 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 and at least one elastic bushing are float-coupled, and the ball joint is located at 1°, 2. The elastic bushing is located in one of the fourth quadrants, and the elastic bushing is located in any of the remaining three quadrants excluding the quadrant in which the ball joint is located, and the elastic bushing is With a simple structure in which the spring unit is arranged so that the deformation direction is restricted to the toe-in direction, and the spring unit is attached to the wheel support member at a position forward of the ball joint, the toe-in effect is suppressed against lateral force and bump load. This can be achieved effectively and reliably, and it is also possible to obtain a toe-in effect on the brake force, engine braking force, and engine driving force, which improves the handling stability of the automobile and simplifies the rear suspension structure a'7)88. This will greatly contribute to the

In addition, since the wheel is rotated and displaced around the ball joint in response to the wheel acting force, the wheel is less likely to shift due to the acting force and has excellent behavior stability, making the above-mentioned toe-in effect more reliable. can.

Furthermore, the toe-in effect due to the bump load mentioned above can be effectively and reliably achieved by using the downward spring reaction force of the existing spring unit, which not only further improves handling stability but also further simplifies the structure. This has the advantage that it can be used for various purposes.

[Brief explanation of the drawing]

The drawings illustrate embodiments of the present invention; FIG. 1 is a schematic perspective view of the first embodiment, FIG. 2 is a schematic perspective view of the second embodiment, and FIG. 3 is a schematic perspective view of the third embodiment. A perspective view, FIG. 4 is a schematic explanatory view showing the arrangement structure of the ball joint, the first and second elastic bushings, and the spring unit, and FIG. 5 is a schematic explanatory view showing a modification of the same. 1. Semi-trailing arm, 6. 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, 2! I...Wheel, 24...Wheel hub, 25...Spring unit, P...Ball joint,...First elastic bushing, Yu...Second
Elastic bushing, 0...wheel center.

Claims (1)

[Claims] +1+ A swinging member whose one end is swingably supported on the vehicle body, a wheel support member which rotatably supports the wheel,
a ball joint that connects the wheel support member and the swinging member so as to be able to swing around one point; and at least one elastic bushing that connects the wheel support member and the swinging member; a spring unit whose upper end is connected to the vehicle body and whose lower end is connected to the wheel support member; Second. The elastic bushing is located in one of the fourth quadrants, and the elastic bushing is located in any of the remaining three quadrants excluding the quadrant in which the ball joint is located, and the elastic bushing is A rear suspension for an automobile, characterized in that the spring unit is arranged and arranged so that the direction of deformation is restricted to the toe-in direction, and the spring unit is installed at a position forward of a ball joint connection point of a wheel support member.