JPH0924717A - Rear suspension - Google Patents

Abstract

(57) [Summary] [Purpose] For rear suspension of low floor buses, etc.
The load of the beam supporting the air spring is reduced and the overall length of the shock absorber is shortened. [Structure] A side gear box 2 is provided on each of left and right ends of a rear axle housing in a bus, and front and rear beams 11 and 17 are fixed to front and rear surfaces thereof.
The front side air spring 15 and the rear side air spring 19 are attached to the front ends of the shock absorber 51, the lower end of the shock absorber 51 is attached to the front and rear surfaces, and the upper end of the shock absorber 51 is attached to the frame 52. 54 is installed on the vehicle body side above the side gear box 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear suspension capable of lowering the floor of a room such as a bus, and more particularly,
The shock absorber mounting structure is related.

[0002]

2. Description of the Related Art A conventional rear suspension for a low floor bus is provided with beams extending from the rear axle case to the front and rear of the left and right rear wheels, respectively, as illustrated in Japanese Utility Model Laid-Open No. 20808/1992. While the air springs are located, the shock absorbers are attached to the ends of the beams outside the air springs. In this case, the air springs and the shocks are attached to the ends of the beams. Since a large load is applied through both absorbers, it is necessary to increase the strength at the base end of each beam.Because the shock absorbers are tilted forward and backward, the entire length of the shock absorber is inevitable. Longer and therefore avoid increasing the weight of the entire rear suspension. It was not.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the load on the beam supporting the spring and to make the overall length of the shock absorber relatively short in the rear suspension of a low floor bus or the like. Is.

[0004]

For this reason, in the rear suspension according to the present invention, the base end portion is fixed to the end portion of the rear axle housing in the vehicle width direction and extends forward, and the front end portion is located in front of the rear wheel. A pair of left and right front beams,
The front side springs arranged between the front end portions of the front side beams and the vehicle body, and the base end portions of the rear axle housings fixed to the end portions in the vehicle width direction of the rear axle housing are extended rearward so that the front end portions are rearward of the rear wheels. A pair of left and right rear beams,
A rear spring disposed between the tip of each of the rear beams and the vehicle body, a lower end of the rear axle housing is supported by a vehicle width direction end of the rear axle housing, and an upper end of the rear axle housing is supported by the vehicle body to be substantially upright. It has a shock absorber arranged in a state.

In this case, the front side spring and the rear side spring respectively have a pair of left and right front beams and a pair of left and right rear beams whose base ends are fixed to the vehicle width direction ends of the rear axle housing. The lower end of the shock absorber is arranged between the front end of each beam and the vehicle body at the front and rear of the rear wheel, and the lower end of the shock absorber is supported by the end of the rear axle housing in the vehicle width direction. Since the upper end is supported on the vehicle body side, the load from the shock absorber acts on the widthwise end of the rear axle housing, and the front beam and rear beam are not loaded through the shock absorber. Also, the load acting on each base end portion of the rear beam can be made relatively small.

Further, the lower end of the shock absorber is supported by the end of the rear axle housing in the vehicle width direction, and the upper end of the shock absorber is supported by the vehicle body so that the shock absorber is arranged in a substantially upright state. Therefore, the damping efficiency of the shock absorber is increased, and therefore, the overall length of the shock absorber can be set to be relatively short and the size can be reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention shown in the drawings will be described below. The rear axle housing 1 of the bus is arranged relatively low, and side gear boxes 2 are integrally provided at the left and right ends of the vehicle in the vehicle width direction. The rotation of the rear axle shaft 3 is decelerated to the axle 4 located above it. The rear axle housing 1 is configured to be transmitted, and the rear wheel 5 is connected to the axle 4.
The differential unit 6 is disposed to the right of the center of the vehicle, that is, on the side opposite to the left side of the vehicle including the entrance / exit.

On the other hand, the front surface 1 of the left and right side gear boxes 2
0, the base end 12 of the front beam 11 is bolted to the front beam 11 using the upper and lower bolt holes 13, respectively.
1 extends to the front of the rear wheel 5, and a front air spring 15 for vehicle body suspension is mounted on a mounting surface 14 formed at the tip of the rear wheel 5, and in the same manner, on the rear surfaces 16 of the left and right side gear boxes 2, respectively. The base end 18 of the rear beam 17 is bolted, the rear beam 17 extends rearward of the rear wheel 5, and the rear air spring 19 for vehicle body suspension is mounted on the mounting surface 14 formed at the front end thereof. Has been.

The loaradius rod 20 has a bilaterally symmetrical structure in which two rods 21 are integrated in a V shape.
The rear end eyeball portion 22 to which the two rods 21 are connected can be swung vertically and horizontally by a spherical joint 24 on a bracket 23 bolted to the front surface of the central portion of the rear axle housing 1 and a resin bush or rubber bush 25. Pivotally attached to the side frame 26 and the outrigger 27.
It is fixed to a bracket 28 that is bolted to the connecting part of the rod, and a horizontal support pin 29 having a circular central cross section allows the front end eyeball portion 30 of each rod 21 to swing up and down with a rubber bush 31 interposed therebetween. Is pivoted to
The lower radius rod 20 suppresses displacement of the rear axle housing 1 with respect to the vehicle body in the front-rear direction and the left-right direction.

Further, the left and right upper radius rods 40 extending in the front-rear direction of the vehicle respectively have front end eyeball portions 41 with respect to the bracket 42 bolted to the outrigger 27, as in the case of the front end eyeball portion 30. The horizontal support pins 43 are pivotally attached to the inside of the front air spring 15 so as to be able to swing up and down with rubber bushes interposed. Further, the support pins 44 similar to the support pins 43 are attached to the front beam base ends. The side gear box front surface 1 is bolted to a screw hole 45 formed in the upper portion of the portion 12 and is inserted through a bolt hole 46 on the inner side of the screw hole 45.
Are fixed indirectly and directly to the side gear box front surface 10 by bolts screwed into 0,
The rear end eyeball portion 47 of each upper radius rod 40 is pivotally attached to the front beam base by a horizontal support pin 44 similarly to the case of the front end eyelet portion 30 so as to be vertically swingable with a rubber bush 48 interposed therebetween. By being attached to the front surface 10 of the side gear box via the end portion 12, each upper radius rod 40 is arranged substantially above the front beam 11 to suppress the displacement of the rear axle housing 1 with respect to the vehicle body in the front-rear direction.

On the other hand, the pins 50 are provided on the front surface 10 of the side gear box immediately above the left and right front beam base end portions 12, respectively.
The lower ends of the shock absorbers 51 are supported by the side gear box front face 10 via the pins 50, and the same pin is also provided on the side gear box rear face 16 immediately above the left and right rear beam base ends 18. Are screwed in, the lower ends of the shock absorbers 51 are respectively supported by the rear surface 16 of the side gear box via the pins, and the upper ends of the shock absorbers 51 are fixed to the pins 52 fixed to the frame 52 constituting the tire house. The shock absorbers 51 are respectively supported by the frame 52 via the, and the shock absorbers 51 are arranged in a substantially vertical upright state.

A rubber spring, a so-called bump stopper 54, is held on the vehicle body side by a frame 52 or the like above the center of the upper surfaces of the left and right side gear boxes 2, and the upper surface of either the left or right side gear box 2 is bump stopper 54. The car body roll angle when it comes into contact with
The front side arranged outside the bump stopper 54 in the vehicle width direction so that the vehicle body roll angle when the bump stoppers built in the left and right front side air springs 15 and the rear side air springs 19 act is increased by about 2 °. The maximum contraction amounts of the air spring 15 and the rear air spring 19 are set to be large so that the rolling of the vehicle body on the twisted road is not insufficient.

As described above, the entire rear suspension is symmetrically arranged on the left and right sides, and the central passage 60 in the rear portion of the vehicle compartment includes the left and right front beams 11, front air springs 15, rear beams 17, and rear air. The spring 19, the side gear box 2, the upper radius rod 40, the shock absorber 51, the bump stopper 54, and the differential portion 6 of the rear axle housing 1 are formed so as to be avoided.

Between the outer surface of the front end portion of the left front beam 11 where the entrance / exit is provided and the outrigger 27,
A leveling valve 70 with an expandable cylinder is provided, and a normal rod type leveling valve 71 is provided between the outer surface of the front end portion of the right front beam 11 and the outrigger 27. The stroke length of the cylinder at 70 is determined by the distance between the cylinder of the leveling valves 70 and 71 and the rod in the vehicle width direction, the amount of kneeling given to the vehicle body, the cylinder stroke until the bump stopper 54 acts due to the roll of the vehicle body, and the like. It is a thing.

In the above-mentioned device, the lower end of the shock absorber 51 is attached to the front surface 10 and the rear surface 16 of the left and right side gear boxes 2 which are integrally provided at the end portions of the rear axle housing 1 in the vehicle width direction through the pins 50, respectively. Since the lower ends of the shock absorbers 51 are supported and are not connected to the left and right front and rear beams 11 and 17, loads acting on the shock absorbers 51 are directly supported by the left and right side gear boxes 2 and the shock absorbers 51 are supported. Since no load is applied to the front beam 11 and the rear beam 17 through 51, the attachment strength of the front beam base end 12 and the rear beam base end 18 to the side gear box front face 10 and the rear face 16 is relatively small. Can also be the rear axle housing By distributing the load to the front beam 11 and the rear beam 17, not only the weight of the rear axle housing 1 side to which the front beam 11 and the rear beam 17 are attached can be reduced, but also the front beam 11 and the rear beam 17 can be easily reduced in weight, The mounting bolt also has the advantage of being relatively small.

The left and right shock absorbers 51 have their lower ends supported by the front surface 10 and the rear surface 16 of the side gear box 2, respectively, while the upper ends thereof are respectively supported by the frames 52 constituting the tire house, so that they are substantially vertically upright. Shock absorber 51 because it is arranged in the state
The damping efficiency can be increased, and the overall length of the shock absorber 51 can be made relatively short, so that the shock absorber 51 can be easily downsized.

Furthermore, the lower ends of the left and right shock absorbers 51 are respectively the front surface 10 and the rear surface 1 of the side gear box.
6 and the bump stopper 54 is held on the vehicle body side above the center of the upper surfaces of the left and right side gear boxes 2, the left and right shock absorbers 51 in the vehicle width direction are provided.
Is substantially the same as the distance between the left and right bump stoppers 54, and the minimum length when the shock absorber 51 contracts can be brought close to the maximum vertical distance when the bump stoppers 54 act, and moreover, the left and right front sides in the vehicle width direction. Beam 11
Since the distance between the left and right shock absorbers 51 is smaller than the distance between the rear beams 17, when the vehicle body leans to the left or right when the vehicle rebounds, the front air spring 15
And the vertical stroke of the rear air spring 19
The vertical stroke of the shock absorber 51 may be small, so that the shock absorber 51 can be easily downsized also from this aspect.

A side gear box 2 is integrally provided at each end portion of the rear axle housing 1 in the vehicle width direction, and a front end portion 10 and a rear end portion of the front beam 11 are provided on the front surface 10 and the rear surface 16, respectively. The base end portion 18 of 17 is bolted, the lower end portion of the shock absorber 51 is supported through the pin 50, and the rear end eyeball portion 4 of the upper radius rod 40 is supported on the front surface 10.
7 is attached via the support pin 44 and the front beam base end portion 12, and the front beam base end portion 12, the rear beam base end portion 18, the shock absorber 51 lower end portion and the upper radius rod rear end portion 47 are attached. Since it is not necessary to provide each part on the rear axle housing 1,
The overall shape of the rear axle housing 1 can be easily simplified, and the upper and lower screw holes for attaching the pin 50 at the lower end of the shock absorber 51 and the beam base ends 12 and 18 are on the same plane. Since it is possible to easily process the front surface 10 and the rear surface 16 of the box at the same time, the productivity of the rear axle housing 1 is improved,
The cost can be reduced.

Further, the front beam base end portion 12, the rear beam base end portion 18 and the lower end portion of the shock absorber 51 are attached to the front surface 10 and the rear surface 16 of the side gear box 2 having high strength in the rear axle housing 1, and at the same time, the shock absorber. The upper end of 51 is attached to the frame 52 via a pin 53 and is supported by a portion having a relatively high rigidity on the vehicle body side.

The left and right shock absorbers 51 are
The lower end portions are attached to the upper portions of the front surface 10 and the rear surface 16 of the side gear box, are supported in an upright state, and are disposed inside the front air spring 15 and the rear air spring 19, so that the air is different from the conventional device. Compared to the case where the shock absorber is arranged on the outer side of the spring, the vertical stroke of the left and right rear wheels 5 located on the outer side can be largely allowed, so that the ride comfort and steering stability of the vehicle can be easily improved. Can be made.

Further, the bump stopper 54 is held by the vehicle body side frame 52 and the like located above the center of the upper surfaces of the left and right side gear boxes 2, while the shock absorber 5 is held.
1 is arranged in the vicinity of the bump stopper 54, the upper end of which is supported by the same frame 52, and the frame 52 or the like which is a reinforcing member on the vehicle body side can be commonly used for mounting the bump stopper 54 and the shock absorber 51. The structure simplification and the weight reduction can be promoted at the same time.

Moreover, since the shock absorbers 51 are arranged in front of and in the rear of the left and right side gear boxes 2, respectively, a sufficient damping force can be obtained even if the shock absorber 51 is relatively small, and the rear suspension can be provided. Compactness can be promoted easily.

In the above embodiment, since the upper and lower ends of the shock absorber are eye-shaped, the upper and lower ends thereof are supported by pins, respectively. However, when the upper and lower ends of the shock absorber are stud type, It goes without saying that the upper and lower ends thereof may be supported by the respective brackets at the same locations as in the case of the above-described embodiment, and the number of shock absorbers installed in the rear suspension is required. Depending on the damping force of the rear axle housing, only the front of the side gear box at both ends of the rear axle housing or only the rear of the side gear box may be provided.

[0024]

In the rear suspension according to the present invention, the load from the shock absorber acts on the end portion of the rear axle housing in the vehicle width direction, and the front beam and the rear beam are not loaded through the shock absorber. The load acting on the base end portions of the front beam and the rear beam can be made relatively small, and the overall weight can be easily reduced by distributing the load to the rear axle housing, and the shock absorber is Since the shock absorbers are arranged in a substantially upright state and have high damping efficiency, the shock absorber can be downsized and the entire rear suspension can be made compact.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment of the present invention.

FIG. 2 is a side view of the embodiment example.

FIG. 3 is an enlarged view of a main part taken along the arrow III in FIG.

FIG. 4 is an enlarged cross-sectional view taken along the line IV-IV in FIG. 1;

FIG. 5 is an enlarged cross-sectional view taken along line VV of FIG. 1;

6 is an enlarged cross-sectional view taken along the line VI-VI of FIG.

[Explanation of symbols]

 1 Rear Axle Housing 2 Side Gear Box 5 Rear Wheel 11 Front Beam 15 Front Air Spring 17 Rear Beam 19 Rear Air Spring 20 Lower Radius Rod 24 Spherical Joint 26 Side Frame 27 Outrigger 29 Support Pin 40 Upper Radius Rod 43 Support Pin 44 Support Pin 51 Shock Absorber 54 Bump stopper 60 Central passage 70 Leveling valve 71 Leveling valve

Claims (7)

[Claims] 1. A pair of left and right front beams, each of which has a base end portion fixed to a vehicle width direction end portion of a rear axle housing and extends forward and a front end portion of which is located in front of a rear wheel, and a front end portion of each front beam. A front spring disposed between the vehicle body and a pair of left and right rear beams whose rear end is fixed to a rear end of the rear axle housing and whose rear end extends rearward and whose front end is located behind the rear wheel. A rear spring arranged between the tip of each of the rear beams and the vehicle body, a lower end of the rear axle housing is supported by an end portion in the vehicle width direction of the rear axle housing, and an upper end thereof is supported by the vehicle body. Rear suspension with shock absorbers placed almost upright. 2. The rear suspension according to claim 1, wherein the shock absorber is arranged inside the front spring and / or the rear spring in the vehicle width direction. 3. The bump stopper according to claim 1 or 2, further comprising a bump stopper attached to the vehicle body above an end portion of the rear axle housing in a vehicle width direction, wherein the shock absorber is arranged near the bump stopper. Rear suspension. 4. The rear suspension according to claim 1, wherein a plurality of the shock absorbers are arranged at intervals in the front-rear direction of the vehicle body. 5. The lower end portion of the shock absorber and the front beam base end portion, or the lower end portion of the shock absorber and the rear beam base end portion according to any one of claims 1 to 4, wherein: A rear suspension mounted in the same plane at the end of the rear axle housing in the vehicle width direction. 6. The rear suspension according to claim 5, wherein the flat surface faces the front of the vehicle or the rear of the vehicle. 7. The rotating shaft height converting side gear box is provided at both ends of the rear axle housing, and the front beam base end and the rear beam base end are provided. Rear suspension with the parts fixed to the front and rear surfaces of the side gear box.