JPH0780406B2 - Car rear suspension - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rear suspension used in an automobile.

<Prior art> The axle suspension method is the mainstream for the rear suspension of large vehicles such as trucks and buses.

<Problems to be Solved by the Invention> In the case of the independent suspension method for a passenger car, riding comfort and maneuverability are advantageous, but the axle suspension method for a large-sized vehicle is disadvantageous in riding comfort and maneuverability.

An object of the present invention is to provide a rear suspension that is of an axle suspension type and has improved riding comfort and maneuverability.

<Means for Solving the Problems> According to the configuration of the present invention for achieving the above object, the rear axle is provided with an appropriate interval in the lateral direction of the chassis and in the longitudinal direction of the chassis with the front downward slope axis. A pair of left and right upper arms connected to the side, the front end of the front axle of the rear axle in the longitudinal direction of the chassis is connected to the chassis side at the front side of the rear axle, and the rear end is connected to the differential case in front of the center axis of the rear axle, and It consists of a pair of left and right lower arms that intersect the direction of the forward tilting axis in the direction of the frontward and downward tilting axis of the upper arm in front of the rear axle. V
It is arranged in the shape of a letter, and the intersection C of the virtual extension line of the front downhill tilt axis of the upper arm and the front downhill tilt axis of the lower arm is set higher than the height Tt of the rear axle from the road surface. Is.

<Operation> With the above configuration, the vehicle can be understeered and the steering response can be improved.

<Examples> Examples of the present invention will be described below with reference to the drawings. 1 and 2, 30 is a bus to which the present invention is applied, and 10 is a rear suspension according to the present invention.

The rear suspension 10 includes a pair of left and right air springs (not shown) that support axle tubes 31 and 32 of a rear axle (not shown) on a chassis (not shown), a pair of left and right upper arms 11 and 12, and a lower arm. Consists of 13 and. The rear axle has rear wheels 35, 36,
37, 38 are fixedly supported, and the air spring is connected to the chassis.

The pair of left and right upper arms 11 and 12 are arranged at appropriate intervals in the lateral direction of the chassis as understood in FIG. 1, and in the longitudinal direction of the chassis as understood in FIG. Axle tubes 31 and 32 are connected to a chassis bracket (not shown) by a descending tilt axis. In this connection, the tips of the upper arms 11, 12 are ball joints 14,
The upper ends of the upper arms 11 and 12 are rotatably connected to the brackets 21 and 22 screwed to the axle tubes 31 and 32 via ball joints 16 and 17, respectively. A forward-downward tilt axis line having a predetermined angle is provided.

The lower arm 13 is also composed of a pair of left and right, and as can be understood from FIG. 2, in the longitudinal direction of the chassis, the front descending tilt axis, and the rear end thereof at a position ahead of the axial center of the rear axle by a distance LC1, and Def case with height Hr from road surface 40
It is rotatably connected to the lower part of 34 via ball joints 41 and 42, and its front end is rotatably connected to a bracket (not shown) of the chassis via ball joints 18 and 19.

Further, as shown in FIG. 1, the axis line of the pair of left and right lower arms 13 viewed from above is an intersection 20 at a position behind the axis of the rear axle by a distance LC2. The lines are arranged in a V-shape.

Further, the front upward inclination axis of the lower arm 13 intersects with the front downward inclination axis of the upper arms 11 and 12.
That is, the intersection C is a distance Ld forward of the axis of the rear axle and a height HC from the road surface 40. The intersection C is set to be higher than the height Tt of the axis of the rear axle from the road surface 40.

Next, the operation of the above configuration will be described. Now, when the bus 30 is accelerated, if the driving force Ft is generated on the rear wheels 35, 36, 37, 38, the anti-dive car (Ft · Tt / Ld) acts on the roll center C of the vehicle body, 30 less pitching.

Also, when the bus 30 is decelerated, or when traveling on a bumpy road surface, the braking force on the rear wheels 35, 36, 37, 38, or if disturbance Fb from the road surface 40 is generated or received, anti-lift The force (Fb, Tt / Ld) acts on the roll center C of the vehicle body, reducing the pitching of the bus, as in the previous acceleration. In particular, regarding the joint of the road surface 40, the lower arm 13 is swung in the vertical direction around the ball joints 18 and 19 at the tip end thereof, and
Since the rear end of the lower arm 13 connected by the ball joints 41, 42 below 4 is retracted and the so-called rear axle is retracted, a buffering effect, so-called harshness reducing effect is produced.

Furthermore, when the bus 30 turns, the roll center Hr of the rear axle is low, so the load movement is small, the cornering power of the tires is effectively exerted, and the height Hc of the roll center C of the vehicle body is high. The roll becomes smaller. In addition, the lower arm 13 has an intersection 20 of its V-shaped axis.
Is substantially retracted backwards from the axis of the rear axle by a distance LC2, so the lateral force causes the rear axle to turn in the same direction as the front wheels centering on the intersection point 20, creating an understeer effect and improving maneuverability. To be done. Further, the upper arms 11 and 12 are swung up and down in opposite directions by the roll of the vehicle body, and in FIG. 1, the projected lengths of the upper arms 11 and 12 are changed to be long on the one hand and short on the other hand. The rear axle turns around the intersection 20 in the same direction as the front wheels, and as a result, an understeer effect occurs and maneuverability is improved.

The rear axle may be supported by a coil sprig or a leaf spring instead of the air spring. Further, the ball joints 14, 15, 16, 17, 18, 19 may have rubber bushes interposed.

<Effects of the Invention> As described above, according to the present invention, a pair of left and right upper arms that are arranged at appropriate intervals in the lateral direction of the chassis and that connect the rear axle to the chassis side by the front downward slope axis in the longitudinal direction of the chassis. In the longitudinal direction of the chassis, connect the front end of the front axle of the rear axle to the chassis side with the forward inclination axis, connect the rear end to the differential case in front of the center axis of the rear axle, and incline the forward inclination in front of the rear axle. It consists of a pair of left and right lower arms that intersect the axial direction in the direction of the front downward tilt axis of the upper arm, and the pair of left and right lower arms is arranged behind the rear axle in a V-shape whose virtual extension lines intersect. Moreover, the intersection C of the virtual extension line between the front-down inclination axis of the upper arm and the front-down inclination axis of the lower arm is at the rear axle. Since it is configured to be higher than the height Tt of the axis of the through from the road surface, pitching and rolling are reduced,
The harshness reduction effect and the understeer effect improve the riding comfort and improve straightness, turning performance, and maneuverability.

Further, the rear end position of the lower arm is configured by connecting the rear ends of the pair of left and right lower arms, which are arranged in a V shape behind the rear axle, where virtual extension lines of the axis intersect, to the differential case in front of the central axis of the rear axle. A large height Hc can be obtained from the road surface, a minimum vehicle ground height with a large height can be secured, and the above-described operational effects are achieved.

[Brief description of drawings]

FIG. 1 is a schematic plan view of a rear suspension used for an automobile of the present invention applied to a rear axle of a bus, and FIG. 2 is a schematic side view of the rear suspension shown in FIG. 11,12 …… Upper arm, 13 …… Lower arm.

Claims (1)

[Claims] 1. A pair of left and right upper arms that are spaced at appropriate intervals in the lateral direction of the chassis and that connect the rear axle to the chassis side with a forward-downward tilt axis in the vertical direction of the chassis, and a forward-upward tilt in the vertical direction of the chassis. Connect the front end to the chassis side on the front side of the rear axle along the axis, connect the rear end to the differential case in front of the center axis of the rear axle, and in the front of the rear axle, tilt the forward and upward axes in the forward and downward tilt directions of the upper arm. It is composed of a pair of left and right lower arms that intersect with each other in the direction of the axis, and the pair of left and right lower arms are arranged behind the rear axle in a V-shape where virtual extension lines of the axes intersect, and a front downward slope axis of the upper arm. The intersection C of the virtual extension line with the lower descent axis of the lower arm is the height Tt from the road surface of the rear axle axis. Rear suspension for automobiles, which is characterized by being set at a much higher level.