JP3104581B2 - Rear suspension - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear suspension which can lower the floor of a room such as a bus.

[0002]

2. Description of the Related Art A conventional low-floor bus rear suspension is provided with beams extending from the rear axle case to the front and rear of the left and right rear wheels, as exemplified in Japanese Utility Model Laid-Open No. Hei 4-20808, and provided at the ends thereof. Although the air spring is located, the lower radial rod is placed in front of the front beam, so it is inevitable that the rod length will be restricted, and the V-shaped upper radius rod will be located almost in the center of the rear axle case. Because of the connection to the part, lowering the floor height between the left and right front beams is limited by the presence of the upper radius rod, and therefore, it is difficult to ensure sufficient ease of getting on and off the bus.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to make it possible to make the floor of a bus or the like having a rear suspension rod having a lower radial rod and an upper radial rod particularly low.

[0004]

Therefore, a rear suspension according to the present invention has a base end portion fixed to an end portion in the vehicle width direction of a rear axle housing, extends forward of a rear wheel, and has a vehicle suspension mounted on a front end portion thereof. A pair of left and right front beams provided with front springs, and rear ends of the rear axle housings each having a base end fixed to a vehicle width direction end and extending rearward of the rear wheel, and a rear spring for body suspension on the front end thereof. A pair of left and right rear beams, each of which is disposed substantially in the front-rear direction of the vehicle and has a front end pivotally attached to the vehicle body and a rear end pivotally attached to the vehicle width direction end of the rear axle housing. And the upper radius rod
A lower radial rod comprising two rods arranged symmetrically below the upper radius rod, wherein the distance between the front ends of the rods in the vehicle width direction is between the rear ends of the rods; The front ends are pivotally attached to the vehicle body, and the rear ends are pivotally attached to substantially the center of the rear axle housing in the vehicle width direction.

In this case, a front spring for suspension of the vehicle body and a rear spring for suspension of the vehicle body are disposed in front of and behind the rear wheel by a pair of left and right front beams and a pair of left and right rear beams, respectively. While the space between the rear wheels is not particularly restricted by the two springs, the pair of left and right upper radius rods are respectively disposed substantially in the front-rear direction of the vehicle, and the rear ends thereof are pivotally connected to the end of the rear axle housing in the vehicle width direction. Since the length of the upper radius rod can be set relatively freely, and the distance between the left and right upper radius rods in the vehicle width direction can be increased,
The floor surface such as a vehicle interior passage formed near the center in the vehicle width direction can be easily set low without being restricted by the existence of the upper radius rod.

Further, since the lower radial rod composed of two symmetrically disposed rods is located below the upper radial rod, the floor surface between the left and right front beams is set low even if disposed between the left and right front beams. The distance between the front ends of both rods in the vehicle width direction is larger than the distance between the rear ends of both rods in the vehicle width direction, and the front and rear ends of the vehicle body and rear axle, respectively. Since the rear axle housing is pivotally attached to the housing, displacement of the rear axle housing in the vehicle width direction can be effectively suppressed.

[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 disposed relatively low, and side gear boxes 2 are integrally provided at left and right end portions in the vehicle width direction. The rotation of the rear axle shaft 3 is reduced to the axle 4 located above the rear axle shaft 3. The rear axle housing 1 is configured so that the rear wheel 5 is connected to the axle 4.
The differential section 6 is located on the right side of the center of the vehicle, that is, on the side opposite to the left side of the vehicle having a not-shown entrance.

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 using its upper and lower bolt holes 13, respectively.
Reference numeral 1 extends forward of the rear wheel 5, and a front air spring 15 for suspension of the vehicle body is mounted on a mounting surface 14 formed at the tip of the rear wheel 5. A rear end 17 of the rear beam 17 is bolted, and the rear beam 17 extends rearward of the rear wheel 5. A rear air spring 19 for suspension of the vehicle body is mounted on a mounting surface 14 formed at the front end thereof. Have been.

The lower radial rod 20 has a 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 up and down and left and right by a spherical joint 24 on a bracket 23 and a resin bush or a rubber bush 25 which are bolted to the front of the central portion of the rear axle housing 1. And a side frame 26 and an outrigger 27
Is fixed to a bracket 28 bolted to the connecting portion of the, and the front end eye portion 30 of each rod 21 can swing up and down with a rubber bush 31 interposed therebetween by a horizontal support pin 29 having a circular central cross section. Is pivoted to
The lower radial rod 20 suppresses the displacement of the rear axle housing 1 in the front-rear direction and the left-right direction with respect to the vehicle body.

Further, the left and right upper radius rods 40 extending in the front-rear direction of the vehicle have front end eye portions 41 attached to a bracket 42 bolted to the outrigger 27 in the same manner as the front end eye portion 30 described above. The horizontal support pins 43 are pivotally pivoted up and down through rubber bushes on the inner side of the front air springs 15 respectively, and a support pin 44 similar to the support pin 43 is provided at each front beam base end. Bolts are screwed into screw holes 45 formed in the upper part of the portion 12, and the bolt holes 46 on the inner side of the screw holes 45 are inserted into the front side 1 of the side gear box 1.
0 are indirectly and directly fixed to the side gear box front face 10 by bolts screwed into
The rear end eye portion 47 of each upper radius rod 40 is pivotally pivoted up and down by a horizontal support pin 44 via a rubber bush 48 in the same manner as in the case of the front end eye portion 30 so as to be swingable up and down. By being attached to the front side 10 of the side gear box via the end portion 12, each upper radius rod 40 is arranged substantially above the front beam 11, and the displacement of the rear axle housing 1 with respect to the vehicle body in the front-rear direction is suppressed.

On the other hand, a pin 50 is provided on the front surface 10 of the side gear box immediately above the base end 12 of the left and right front beams.
Are screwed to support the lower end of the shock absorber 51 on the front face 10 of the side gear box via the pin 50, and the same pin is also provided on the rear face 16 of the side gear box immediately above the base end 18 of the left and right rear beams. Are screwed, and the lower end of the shock absorber 51 is supported on the rear surface 16 of the side gear box via the above-mentioned 50, and the upper end of each shock absorber 51 has a pin 53 fixed to a frame 52 constituting the tire house. , And each is supported by a frame 52, and each of the shock absorbers 51 is disposed in a substantially vertical upright state.

Above the center of the upper surface of the left and right side gear boxes 2, a rubber spring, a so-called bump stopper 54, is held on the vehicle body side by a frame 52 or the like. For the body roll angle when contacting
The front side disposed outside the bump stopper 54 in the vehicle width direction such that the roll angle of the vehicle body when the bump stoppers incorporated in the left and right front air springs 15 and the rear air spring 19 act is increased by about 2 °. The maximum contraction amount of the air spring 15 and the rear air spring 19 is set to be large so that the rolling of the vehicle body on the torsion road is not insufficient.

As described above, the entire rear suspension is configured symmetrically on the left and right sides. The central passage 60 at the rear of the vehicle compartment includes the left and right front beams 11, the front air spring 15, the rear beams 17, and the 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.

In addition, between the outer surface of the front end of the left front beam 11 where the entrance is provided and the outrigger 27,
An extendable and retractable cylinder-equipped leveling valve 70 is provided, and a normal rod-type leveling valve 71 is provided between the outer surface of the distal 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 cylinders and rods of the leveling valves 70 and 71 in the vehicle width direction, the amount of kneeling given to the vehicle body, the cylinder stroke until the bump stopper 54 operates by the roll of the vehicle body, and the like. Things.

In the above device, the side gear box 2 is provided at each end of the rear axle housing 1 in the vehicle width direction.
Are provided integrally, the rear axle housing 1 is arranged relatively low, and the differential portion 6 of the rear axle housing 1 is arranged closer to the right than the center of the vehicle, and at the same time, the left and right front beams 11 In addition to the front air spring 15 being arranged in front of the rear wheel 5 and the left and right rear beams 17 being arranged behind the right and left rear air springs 19 behind the rear wheel 5, the left and right upper springs are further arranged. Radius rod 40
Has a front end connected to the outrigger 27 side, a rear end connected to the side gear box front face 10, and is disposed substantially above the left and right front beams 11, respectively. The absorber 51 is disposed, the bump stopper 54 is disposed above the side gear box 2, and the lower radial rod 20 disposed substantially at the center of the vehicle is disposed at a lower position below the upper radial rod 40. As a result, the central passage 60 in the vehicle interior can be installed at a very low level as shown in the drawing, and relatively wide and at a substantially uniform height without being obstructed by these devices. In accordance with the use of the leveling valve 70, the kneeling is performed by inclining the cabin floor surface to the left of the vehicle. Therefore, getting on and off the vehicle from the entrance provided in front of or behind the rear wheel 5 is much easier than before, and the movement of passengers and the like in the central passage 60 in the vehicle is also facilitated. It is convenient.

The upper and lower radial rods 40 and the lower radial rod 20 prevent the rear axle housing 1 from being displaced in the front-rear direction with respect to the vehicle body, and the upper radial rod 40 and the lower radial rod 20 and the left and right front air springs. 15 and the rear air spring 19 suppress the rotational displacement of the rear axle housing 1 about the axis in the vehicle width direction, while the lower radial rod 20 is formed in a V-shape, with the front part facing the vehicle body and the rear part Are connected to the rear axle housing 1 side, respectively, the displacement of the rear axle housing 1 with respect to the left and right of the vehicle can be suppressed by the lower radial rod 20. In this case, the lower radial rod 20 is integrated in a V-shape. Two rods 2 Of the rear axle housing 1 can be strengthened easily, and the front part of the lower radial rod 20 can be attached to the joint of the side frame 26 and the outrigger 27, respectively. Loadias rod 2
0 is supported by a highly rigid body part, which makes it easy to reduce the weight of the vehicle without reducing the strength of the body, and at the same time, the lateral rigidity of the suspension is relatively high, so the space in the cabin is also easy. There are practical advantages that can be extended.

Moreover, the left and right upper radius rods 4
0 are arranged substantially above the left and right front beams 11, respectively, so that the upper radius rods 40 can easily be prevented from interfering with other members. Therefore, the length of each upper radius rod 40 is restricted by the front beams 11. This can be set to an appropriate length without receiving it.

Further, a side gear box 2 is integrally provided at an end of the rear axle housing 1 in the vehicle width direction, and a front end 12 of the front beam 11 and a rear end of the rear beam 11 are provided on the front surface 10 and the rear surface 16, respectively. 17 is bolted, a lower end of the shock absorber 51 is supported via a pin 50, and a rear end eyeball portion 47 of the upper radius rod 40 is supported on the front surface 10 by a support pin 44 and a front beam. The rear axle housing 1 is provided with mounting portions for the front beam base portion 12, the rear beam base portion 18, the lower end of the shock absorber 51, and the rear end portion 47 of the upper radius rod. Since there is no need, the overall shape of the rear axle housing 1 can be easily simplified. The front 10 screw holes of the upper and lower for mounting and a beam base end portion 12, 18 the pin 50 of the shock absorber 51 the lower end is the same plane, respectively
Since the rear axle housing 1 and the rear surface 16 can be easily processed simultaneously, the productivity of the rear axle housing 1 can be improved, and the cost can be reduced.

The front surface 1 of the left and right side gear boxes 2
0, the upper radius rods 4 are respectively set by bolts inserted through the bolt holes 46 of the front beam base end 12.
Since the support pin 44 for pivotally connecting the rear end of the upper radius rod 40 is fastened together with the front end 12 of the front beam, the front and rear inputs of the upper radius rod 40 are directly supported by the rear axle housing 1 and the front air spring 15 and the rear The upper and lower inputs from the side air spring 19 are also partially borne by the bolts, so that the load on the bolts that pass through the front beam base end 12, especially the upper bolt holes 13, can be reduced.

Further, the input to the rear axle housing 1 is appropriately dispersed by the mounting positions of the front and rear beams 11, 17, the lower radial rod 20, the upper radial rod 40, the shock absorber 51, the arrangement of the bump stopper 54, and the like. Therefore, the strength of the rear axle housing 1 can be easily secured.

The front end eye portions 30 of the respective rods 21 of the lower radial rod 20 are connected to the vehicle body via rubber bushes 31, respectively, and the front end eye portions 41 of the upper radius rods 40 are connected to the vehicle body via rubber bushes. And the rear end eye portion 47 of the upper radius rod 40 is connected to the rubber bush 4.
9 is connected to the rear axle housing 1 with
Further, since the front air spring 15 and the rear air spring 19 are provided between the vehicle body and the rear axle housing 1, the input from the rear wheel 5 and the vibration of the rear axle housing 1 are appropriately absorbed or softened. Transmitted to the vehicle body, while the front air spring 1
5 and the rear side air spring 19 are arranged outside the bump stopper 54 in the vehicle width direction, so that the maximum contraction amount of the air springs 15 and 19 is set large as described above, and Since the vertical stroke lengths are large and their cushioning properties are relatively good, the riding comfort of the vehicle can be easily improved.

Also, since the maximum contraction amount of both air springs 15 and 19 is set to be larger than the vertical distance between the upper surface of the side gear box 2 and the bump stopper 54,
By controlling the leveling valve 70, the descending amount on the left side of the vehicle can be easily increased, and the kneeling effect of the left inclination can be enhanced, so that the getting on and off the vehicle can be improved from this aspect as well.

Further, even if the differential portion 6 of the rear axle housing 1 is disposed on the right side of the center of the vehicle, the left and right front air springs 15 and the rear air spring 19 are disposed before and after the rear wheel 5, respectively. Therefore, there is a practical advantage that the arrangement of a propeller shaft (not shown) for connecting the post-installed engine and the differential section 6 is relatively easy.

In the above embodiment, the lower radial rods are integrated in a V-shape. However, these rods are separately provided and arranged in an eight-shape which is opened forward, and the respective front ends are formed. Similarly to the front end of the lower radial rod in the above-described embodiment, the front and rear end portions and the rear end portion are connected to the vehicle body side and the rear axle housing side via a rubber bush and a support pin in the eyeball portion, respectively. It goes without saying that the same operation and effect as in the embodiment can be obtained.

[0025]

In the rear suspension according to the present invention, the rear ends of a pair of left and right upper radius rods arranged substantially in the front-rear direction of the vehicle are pivotally attached to the vehicle width direction ends of the rear axle housing. The distance between the two upper radius rods in the vehicle width direction can be increased, and the floor surface such as an in-vehicle passage formed near the center in the vehicle width direction can be easily set low. Because the performance is always good and it is very convenient, the front end of the lower radius rod is configured with a larger interval in the vehicle width direction than the rear end,
The strength of the entire rear suspension in the vehicle width direction is also increased, so that the weight of the rear suspension can be easily reduced.

[Brief description of the drawings]

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

FIG. 2 is a side view of the embodiment.

FIG. 3 is an enlarged view of a main part as viewed from the arrow III in FIG. 1;

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;

FIG. 6 is an enlarged cross-sectional view taken along the line VI-VI of FIG. 1;

[Explanation of symbols]

 DESCRIPTION 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 (4)

(57) [Claims] 1. A pair of left and right front beams each having a base end fixed to a vehicle width direction end of a rear axle housing, extending forward of a rear wheel, and having a front body suspension front spring provided on a front end thereof. A pair of right and left rear beams, each having a base end fixed to a vehicle width direction end of the rear axle housing and extending rearward of the rear wheel and having a vehicle body suspension rear spring provided on a front end thereof, A pair of left and right upper radius rods, which are arranged substantially in the front-rear direction and whose front end is pivotally attached to the vehicle body and whose rear end is pivotally attached to the end of the rear axle housing in the vehicle width direction, are symmetrically arranged below the upper radius rod. And a lower radial rod composed of two rods, wherein the interval in the vehicle width direction between the front ends of the two rods is between the rear ends of the two rods. A rear suspension which is larger than the interval in the vehicle width direction at the front and rear ends of the rear axle housing, the front ends of which are pivotally attached to the vehicle body and the rear axle housings are pivotally attached to substantially the center of the rear axle housing in the vehicle width direction. . 2. The rear suspension according to claim 1, wherein the rear ends of the lower radial rods are connected to each other, and the rear axle housing is pivotally connected to a substantially central portion of the rear axle housing in the vehicle width direction by a spherical joint. 3. In any of claims 1 to 2, the support which the rear end of the upper radius rod has been fastened and the front beam proximal end by bolts to the vehicle width direction end portions of the rear axle housing Rear suspension pivoted via shaft. 4. The rear axle housing according to any one of claims 1 to 3 , wherein a side gear box for rotating shaft height conversion is provided at each of both ends in the vehicle width direction of the rear axle housing, and the front beam base end and the rear side are provided. A rear suspension having a beam base end fixed to a front surface and a rear surface of the side gear box, respectively.