JPS61263809A - Rear suspension - Google Patents

Abstract

PURPOSE:To improve the running stability of a car, by specifying an intersecting angle on a plane surface between a fulcrum axis of an A arm to a car body and an axis of a lateral rod, in case of a device which supports a rear axle with at least each piece of the A arm and the lateral rod. CONSTITUTION:A bracket 15 is tightly attached to a lower part of a strut 14 whose one end is supported on an axle housing 11 supporting a rear axle 9 free of rotation, via a bracket 13, and a free end part of an A arm 16 is connected to a front end of this bracket 15 via a ball joint 20. A fulcrum shaft 18 supporting both ends 16a of the A arm 16 via an elastic bush is attached to a support member 5 of a rear suspension via a bracket 19. In addition, an interval between the bracket 15 and the support member 5 is connected via a lateral rod 22. At the abovementioned, an interseting angle alpha on a plane surface between a fulcrum axis l1 of the A arm 16 to a car body and an axis l2 of the lateral rod 22 is set to a point proximate to an angle where a toe-in variation comes to maximum at the time of braking.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a vehicle rear suspension.

(Prior Art) Conventional suspensions and suspensions include, for example, those shown in FIGS. 12 and 13 (corresponding to FIGS. 1 and 2 of Japanese Utility Model Application Publication No. 55-1556).

In the figure, 1 is a rear wheel, 2 is a rear suspension, 3 is an A-arm, 4 is a rear axle, and B is an elastic bush provided at the pivot point of the A-arm 3 relative to the vehicle body.

(Problems to be Solved by the Invention) However, in such a conventional rear suspension, the lateral force F as shown in FIG.

When this occurs, each member is displaced as shown by the chain double-dashed line due to the deflection of the elastic bushing B, and as a result, the rear wheel 1 is toe-out by θ. Similarly, when the braking force F2 is applied as shown in FIG. 13, the rear wheel l toes out by θ3, which causes the problem that the running of the vehicle becomes unstable.

(Means for Solving the Problems) In order to solve the above-mentioned problems, in the present invention, in a rear suspension system in which the rear axle is supported by at least one A-arm and one lateral rod, the A-arm is The intersection angle in a plan view of the pivot axis with respect to the vehicle body and the axis of the lateral rod is set close to the angle (approximately 60 degrees) at which the amount of toe-in change is maximized when braking force is applied to the wheels.

(Function) As described above, in the present invention, the intersection angle between the swinging wheel of the A-arm and the lateral rod is set as the angle (approximately 60 degrees) at which the amount of toe-in change is maximum when braking force is applied to the wheel. Since a steering angle in the toe-in direction is generated in the rear wheels when lateral force and braking force are applied to the wheels, the running stability of the vehicle can be improved.

(Example) The present invention will be described in detail below with reference to FIGS. 1 to 11. In the figure, 5 is a suspension support member attached to the vehicle body, 6 is a propeller shaft, 7 is a differential gear, 8 is a rear drive shaft, 9 is a rear axle, 10
is the rear wheel.

1 to 3 show a first embodiment of the present invention,
11 is an axle housing that rotatably supports the rear axle 9; 12 is a brake mounting plate fixed to the housing 11; 13 is a bracket formed integrally with the housing 11; 14 is a strut whose lower part is fixed to the bracket 13; A bracket 16 is an A-arm fixed to the lower end of the strut 14, and its both leg ends 16a support a pivot shaft 18 via an elastic bush 17 via a bracket 19, as shown in FIG. It is attached to the support member 5 of the rear suspension. Also, A-arm 16
The free end 16b of the bracket 15 is connected to the front end of the bracket 15 via a spherical joint 20. Note that 21 is a dust cover.

Reference numeral 22 designates a lateral rod, and its inner end 22a is attached to the support member 5 of the rear suspension at the rear of the differential gear 7 via an elastic bush 17, a pivot shaft 18, and a bracket 19, as shown in FIG. The outer end 22b of the lateral rod 22 is connected to the rear end of the bracket 15 via the spherical joint 20 as described above. Note that 21 is a dust cover. Further, 23 is a torsion bar.

In the rear suspension described above, the pivot axis of the A-arm 16 with respect to the vehicle body! , and the axis of the lateral rod 22! When the intersecting angle α in the plan view with 2 was changed variously and the amount of toe-in change was measured when braking force F and lateral force F3 were respectively applied to the rear wheel 10, the results shown in Fig. 5 were obtained. Obtained. That is, the dotted line is the characteristic when the braking force F is applied, and the solid line is the characteristic when the lateral force F3 is applied. As can be seen from this characteristic diagram, when the intersection angle α is approximately 60 degrees, the braking force Fl and the lateral force F,
It has been found that the amount of toe-in change can be increased both when the function is applied.

That is, the amount of toe-in when the lateral force F3 is applied increases as the intersection angle α becomes smaller, and there is a degree of freedom in selecting the amount of toe-in suitable for the vehicle, but the amount of toe-in when the braking force F is applied increases as the intersection angle α becomes 60. It has a maximum value at ', and decreases rapidly at other intersection angles. Therefore, in order to make the vehicle run stably, it is first important to determine the intersection angle α so that a large amount of toe-in can be obtained when the braking force F is applied.

Therefore, in the present invention, the intersection angle α in the plan view between the pivot axis 11 of the A-arm 16 with respect to the vehicle body and the axis Ilt of the lateral loft 22 is set such that the amount of toe-in change is the maximum when the braking force F is applied to the wheel 10. Set the angle close to (approximately 60 degrees).

That is, as shown in FIG. 6, when a braking force F and a lateral force F are applied to the rear wheel 10, the rear suspension of the present invention changes from the state shown by the solid line to the state shown by the two-dot chain line. As a result, a toe-in state as shown by arrow T is created, and the running stability of the vehicle can be improved. still,
In this embodiment, as shown in FIG. 3, since the struts 14 are offset toward the rear of the vehicle, a sufficient space for the rear seats in the vehicle interior can be secured.

Next, FIGS. 7 to 9 show a second embodiment of the present invention, and the same reference numerals as those described above indicate equivalent parts.

To explain only the differences from the first embodiment, this one has an axle housing 1 instead of the strut 14 of the first embodiment.
A bracket 24 is provided protruding from the upper front part of the vehicle 1, and the bracket 24 and the rear suspension support member 5 of the vehicle body are connected by an upper A-arm 25 in the same manner as the A-arm 16. In this case, the pivot axis to the car body! , are made parallel to the axis β1 in the plan view. Further, a bracket 26 is provided protruding from the rear of the housing 11, and the outer end 22b of the lateral rod 22 is connected to the end of the bracket 26 via the spherical joint 20 as described above. Note that 27 in FIGS. 8 and 9 is a silicon absorber.

Further, FIGS. 10 and 11 show a third embodiment of the present invention, and the same reference numerals as those described above indicate equivalent parts. To explain only the differences from the previous embodiment, this embodiment has a bracket 28 protruding above the axle housing 11 instead of the bracket 24 of the second embodiment.
The front end of the bracket 8 and the rear suspension support member of the vehicle body are connected by a link 29, and the rear end of the bracket 28 and the support member are connected by a link 30. In this case as well, the center line connects the center points of the pivot connecting ends 29a, 30a of each link 29, 30 with the support member! 3 is the vehicle body side pivot axis 2. of the A-arm 16. As in each of the embodiments described above, the angle α between the axes and the axis 13 is set to approximately 60 degrees.

Therefore, the second and third embodiments have the same effect as the first embodiment, and since the rear wheel suspension type is a double wishbone type, when turning,
The outer rear wheel has a negative camber, providing more stable turning characteristics to prevent spin.

(Effects of the Invention) As explained above, in the present invention, in the rear suspension that supports the rear axle 9 by at least one A-arm 16 and one lateral rod 22,
The intersection angle α in the plan view of the pivot axis IlI of the arm 16 with respect to the vehicle body and the axis IlI of the lateral rod 22 is
Since the angle is set close to the angle (approximately 60 degrees) at which the amount of toe-in change is maximum when braking force F is applied to the wheels, the rear wheel 10 is steered in the toe-in direction when braking force F and lateral force F are applied. Since the angle is formed, the excellent effect of improving the running stability of the vehicle, especially when driving at high speeds, can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing a first embodiment of the device of the present invention, Fig. 2 is a rear view, Fig. 3 is a side view of the same, Fig. 4 is a sectional view of the A-arm pivot portion on the vehicle body side, and Fig. The figure is a characteristic diagram showing the relationship between the intersection angle α and the amount of toe-in change, Figure 6 is an explanatory diagram of the operation of the device of the present invention, Figure 7 is a plan view showing the second embodiment of the device of the present invention, and Figure 8 is the rear view. 9 is a side view of the same, FIG. 10 is a plan view showing the third embodiment of the device of the present invention, and FIG.
FIG. 1 is a side view thereof, and FIGS. 12 and 13 are explanatory views of the operation of the conventional device. 5... Rear suspension support member 9... Rear axle 10... Rear wheel 11... Axle housing 13... Bracket 14... Strut 15
・・・Bracket 16・-A arm! ,...A
Vehicle body side pivot axis line 22 of arm 16...Lateral rod l! ...Axis α of the lateral loft 22...Intersecting angle F of 11hlz,...Braking force F3...Lateral force patent applicant
Nissan Motor Co., Ltd. Figure 4 Figure 5 Intersection angle

Claims (1)

[Claims] 1. In a rear suspension that supports the rear axle with at least one A-arm and one lateral rod,
A rear suspension characterized in that the intersection angle in a plan view of the pivot axis of the A-arm with respect to the vehicle body and the axis of the lateral rod is set close to the angle at which the amount of toe-in change is maximized when braking force is applied to the wheels.