JPH07237425A - Start assisting device of vehicle - Google Patents

Abstract

PURPOSE:To provide a device which increases the ground contact pressure of a drive shaft tire when a vehicle starts. CONSTITUTION:A vehicle 1A has a drive axle 31 and a driven axle 32 supported by a suspension 100 to a frame 10. The suspension 100, a trunnion type, supports the axles 31 and 32 through the bracket 110, leaf spring 120 and torque rod 130 fixed to the frame 10. Between the bracket 140 provided integrally with the drive axle 31 and the frame 10, air spring 150 is provided. The air spring 150 has a diaphragm 152, piston 154 and upper supporting section 156, and the piston 154 is mounted on the bracket on the drive axle side. The upper supporting section 156 is supported by the lower face of the frame 10 through a suitable bracket. When the vehicle starts, compressed air is supplied to the air pressure 150 to increase the ground contact pressure of the drive axle tire 31a and increase its thrust force, assisting the start of the vehicle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension for a rear axle of a large vehicle, and more particularly to a device for increasing traction when starting a rear two-axle vehicle.

[0002]

2. Description of the Related Art FIG. 5 is an explanatory view showing an outline of a vehicle having two rear axles. A large vehicle generally designated by reference numeral 1 has a front axle 21 at a front portion of a chassis 10 and a front tire. 21a is supported. The rear part has two axles 31 and 32 and supports tires 31a and 32a, respectively. The rear two axles 31, 32 are supported by the chassis 10 via a suspension 40, and
The cargo 50 is loaded on the 0. Therefore, the total weight WG of the vehicle 1 including the load 50 is the load W applied to the front tire 21a.
F and the load WR applied to the rear tires 31a and 32a are distributed and supported by the road surface G.

By equipping the rear part with two axles 31, 32, the load WR supported by the entire rear part is
The load WRF supported by 1 and the load WRR supported by the rear rear shaft 32 are distributed. Therefore, it is possible to configure a vehicle having a larger load while suppressing the maximum load applied to one shaft. In this type of rear two-axle vehicle, the rear front shaft 31 is a drive shaft that transmits the driving force from the engine, and the rear rear shaft 32 is a driven shaft that does not transmit the driving force. It is popular to construct a so-called 6 × 2 vehicle that simplifies and drives two of the six wheels.

In this 6 × 2 vehicle, the driving tire 3
1a needs to generate a sufficient driving force. Therefore, the axial load WRF applied to the tire 31a needs to be distributed with a load sufficient for the tire to generate a necessary driving force between the tire 31a and the road surface. When the load is loaded, the axial load WRF applied to the drive shaft 31 is also sufficiently large, and the tire 31a can generate a sufficient propulsive force. However, when there is no load and no load is applied, a sufficient load WRF is not distributed to the drive shaft 31, and the tire 31a cannot obtain sufficient propulsive force between the tire 31a and the road surface G. Especially when the vehicle starts or when the road surface has a small friction coefficient, the tire 31
There is a case where a slips to cause inconvenience in starting. For example, Japanese Utility Model Laid-Open No. 57-96081 discloses a device in which a driven shaft tire is floated from a road surface by using a hydraulic cylinder in a vehicle in which the rear two shafts are supported by a walking beam type suspension. Proposed.

[0005]

As described in the above-mentioned publication, in a 6 × 2 vehicle, the rear driven tires are floated from the road surface and run in a 4 × 2 state when the vehicle is idle. As a result, a sufficient driving force can be obtained, which is also preferable in terms of fuel consumption. However, the device disclosed in the above-mentioned publication makes the driven tire float above the road surface by the hydraulic cylinder. The floating driven tire stands still and is supported with a certain ground clearance. When the vehicle runs in this state, the driven tire may come into contact with the road surface due to unevenness of the road surface or the like. Since the driven tire is stationary, a large impact is applied at the moment of contact with the road surface, which causes damage.
Further, in the walking beam type suspension, if the driven shaft is forcibly pulled up, the leaf spring is bent toward the frame side, and the suspension function is greatly deteriorated. The present invention provides a vehicle start assisting device that solves the above-mentioned conventional problems.

[0006]

As a basic means of the present invention, a drive shaft mounted on a vehicle frame via a suspension, and a bracket provided substantially parallel to the drive shaft on the frame, An air spring is provided between the bracket and the frame.

[0007]

The air spring exerts the function of increasing the ground contact pressure of the drive shaft tire by being injected with compressed air and expanding when the vehicle starts.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A case where the present invention is applied to a vehicle equipped with various suspensions having an equalizer function will be described below. FIG. 1 is an explanatory diagram showing an example in which the present invention is applied to a vehicle equipped with a trunnion type suspension. Vehicle 1
A is equipped with a trunnion type suspension 100 at the rear of the frame 10. The trunnion type suspension 100 has a trunnion base 110 attached to the frame 10 via a trunnion shaft,
The central portion of the leaf spring 120 is fixed to the upper portion of the trunnion base 110. Both ends of the leaf spring 120 have the drive shaft 3
1 and the upper part of the driven shaft 32 are brought into contact with each other via sliding sheets 31b and 32b.

The drive shaft 31 is provided with a differential gear case 70 at the center, and the power from the engine side is transmitted through the propeller shaft 60. One end of the torque rod 130 is connected to the upper and lower portions of the drive shaft 31, and the other end of the torque rod 130 is connected to the frame 10 of the vehicle body and the trunnion base 110 integrated with the frame. The driven shaft 32 does not include a power transmission mechanism, and the tire 32a
An axle and a brake mechanism that rotatably support the vehicle are provided. The upper and lower portions of the driven shaft 32 are connected to the frame side via the torque rod 130.

The trunnion type suspension 100 is
The trunnion base 110 has the above basic configuration.
L ₁ from the center of the drive shaft 31 to the center of the drive shaft 31 and L from the center of the trunnion base 110 to the center of the driven shaft 32.
₂ is the length of the torque rod 130 and the leaf spring 120.
It can be set by selecting the length dimension of. The shaft load distributed to the drive shaft 31 and the driven shaft 32 can be adjusted by the ratio of the distances L ₁ and L ₂ . At the time of loading, the load distributed by the drive shaft 31 and the driven shaft 32 is taken over, and the tire 31a of the drive shaft 31 is also given a sufficient load to obtain a necessary propulsive force with the road surface.

In the trunnion type suspension of this embodiment, a bracket 140 is provided on the drive shaft 31, and an air spring 15 is provided between the bracket 140 and the frame 10.
Equip with 0. The air spring 150 has a diaphragm portion 152 that expands and contracts, a piston portion 154, and an upper support portion 156. The piston portion 152 is the bracket 140 of the drive shaft 31.
The upper support 156 is placed on the lower surface of the frame 10 via an appropriate bracket. The diaphragm portion 152 is connected to a supply source of compressed air via a hose or the like. Since a large vehicle of this type is equipped with an air compressor and a high-pressure tank for operating a brake and a clutch, the compressed air can be used to operate the air spring 150.

For example, the tire 31 of the drive shaft 31 when empty
When the ground pressure applied to a is insufficient, compressed air is injected into the air spring to apply a force to push down the drive shaft 31. As a result, the drive shaft tire 31a is given sufficient ground pressure to generate propulsive force. In particular, since the required propulsive force becomes maximum at the time of starting the vehicle, it is possible to detect the starting of the vehicle and instantaneously operate the air spring 150 to assist the starting. Since the air spring has a high responsiveness of operation, the above-described control of operation can be easily achieved.

FIG. 2 shows a case of implementing the present invention and a vehicle 1B having a four-spring type suspension. The suspension generally designated by the reference numeral 200 is a frame 1 of the vehicle body.
Three brackets 210, 212, 21 fixed to 0
Have 4. The first bracket 210 supports the front part of the first plate spring 220, and the rear part of the first plate spring 220 is swingably supported with respect to the second bracket 212, and the front end part of the equalizer beam 260. Supported by. The drive shaft 31 is attached to the lower center of the first leaf spring 220, and the drive shaft 31 and the first bracket 210 are connected by a torque rod 230.

The rear end of the equalizer beam 260 supports the front end of the second leaf spring 222, and the rear end of the second leaf spring 222 is supported by the third bracket 214. The driven shaft 32 is attached to the lower center of the second leaf spring 222. The driven shaft 32 and the second bracket 212 are connected by a torque rod 232. As described above, the present suspension includes the two leaf springs 220 and 222 on one side, and the equalizer beam 260 adjusts the eccentric load.

In this embodiment, the bracket 240 is fixed to the drive shaft 31, and the air spring 250 is provided between the bracket 240 and the frame 10 of the vehicle. The air spring 250 includes a diaphragm portion 252 and a piston portion 2
54 and an upper support portion 256, the piston portion 254 is fixed on the bracket 240, and the upper support portion 256 is brought into contact with the lower portion of the frame 10. By supplying compressed air to the diaphragm portion 252, it is possible to increase the ground contact pressure applied to the drive shaft tire 31a and assist the vehicle 1B in starting.

FIG. 3 shows a case where the present invention is applied to a vehicle 1C having a rocker beam type suspension. The suspension indicated by reference numeral 300 is the frame 1 of the vehicle body.
0 has a bracket 310 fixed to the bracket 3
10 supports the front part of the leaf spring 320. Body frame 1
On the rear side of 0, the frame 10 is provided by the mounting portions 312 and 313.
Shaft 360 via bracket 314 fixed to
And a shaft 360 rotatably supports the rocker arm 362. The front end of the rocker arm 362 supports the rear end of the leaf spring 320 via the rod 364. The drive shaft 31 is attached to the lower center of the leaf spring 320. The driven shaft 32 is attached to the rear end of the rocker arm 362. The driven shaft 32 and the mounting portion 31 on the frame 10 side
A cylinder 370 is disposed between the cylinder 370 and the cylinder 6.

In the apparatus of this embodiment, a bracket 340 is attached to the drive shaft 31, and an air spring 350 is provided between the bracket 340 and the frame 10. The structure and function of the air spring 350 are similar to those of the previous embodiment, and the diaphragm portion 352, the piston portion 354, and the upper support portion 3 are provided.
Has 56 and achieves starting aid.

FIG. 4 shows a case where the present invention is applied to a vehicle 1D having a walking beam type suspension.
The suspension, which is generally designated by the reference numeral 400, includes two brackets 410, 412 fixed to the frame 10 of the vehicle body.
The brackets 410 and 412 support the front and rear of the leaf spring 420. A central portion of the walking beam 430 is rotatably disposed below the center of the leaf spring 420 via a shaft 432. The front end of the walking beam 430 supports the drive shaft 31, and the rear end supports the driven shaft 32. The drive shaft 31 is connected to the differential 70, and power is transmitted from the axle shaft 60.

The upper portion of the differential gear case 70 and the frame 10 are connected by a torque rod 460, and the upper portion of the driven shaft 32 and the frame 10 are also connected to each other by the torque rod 46.
Two are connected. The apparatus of this embodiment is provided with a bracket 460 on the drive shaft 31, and the bracket 460 and the frame 1
Equip air spring 450 between zero. Air spring 450
Like the previous embodiment, has a diaphragm portion 452, a piston portion 454, and an upper support portion 456, and when the vehicle starts, compressed air is injected into the diaphragm portion 452 to drive the drive shaft 31.
Is pushed down to increase the ground contact pressure of the drive shaft tire 31a to assist in starting.

[0020]

As described above, the present invention is particularly applicable to a vehicle that drives one of the two rear axles, and is provided with a suspension having an equalizer function and an air spring. A means for urging is provided. The air spring increases the ground contact pressure of the drive shaft tire and increases the propulsive force to assist the vehicle in starting.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment in which the present invention is applied to a vehicle having a trunnion suspension.

FIG. 2 is an explanatory diagram of an embodiment in which the present invention is applied to a vehicle having an equalizer beam type suspension.

FIG. 3 is an explanatory diagram of an embodiment in which the present invention is applied to a vehicle having a rocker arm type suspension.

FIG. 4 is an explanatory diagram of an embodiment in which the present invention is applied to a vehicle having a walking beam type suspension.

FIG. 5 is an explanatory view of a vehicle having two rear axles.

[Explanation of symbols]

 1, 1A, 1B, 1C, 1D, 1E vehicle 10 frame 31 drive shaft 31a drive shaft tire 32 driven shaft 32a driven shaft tire 70 differential gear case 100 trunnion type suspension 150 air spring 200 equalizer beam type suspension 250 air spring 300 rocker arm type suspension 350 air spring 400 walking beam type suspension 450 air spring 500 rear uniaxial suspension 550 air spring

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B62D 61/12

Claims (5)

[Claims] 1. A drive shaft mounted to a vehicle frame via a suspension, a bracket provided substantially parallel to the drive shaft with the frame, and an air spring mounted between the bracket and the frame. A vehicle start assisting device, wherein the air spring expands when compressed air is injected when the vehicle starts to increase the ground contact pressure of the drive shaft tire. 2. A drive shaft mounted to a vehicle frame via a suspension, a bracket provided substantially parallel to the drive shaft with respect to the frame, and an air spring mounted between the bracket and the frame. The suspension includes a trunnion base supported by a frame, a leaf spring having a central portion fixed to an upper portion of the trunnion base,
A trunnion suspension including a drive shaft and a driven shaft supported at both ends of a leaf spring, and torque rods arranged above and below the drive shaft and the driven shaft, wherein the air spring is a compressed air when the vehicle starts. A vehicle start assisting device, which is injected and extended to increase the ground contact pressure of a drive shaft tire. 3. A drive shaft mounted on a vehicle frame via a suspension, a bracket provided substantially parallel to the drive shaft on the frame, and an air spring mounted between the bracket and the frame. The suspension includes a first leaf spring supporting the drive shaft, a second leaf spring supporting the driven shaft, a first leaf spring end portion and a second leaf spring end portion at both ends. A suspension of an equalizer beam type, which is provided with an equalizer beam which is supported and whose center portion is rotatably supported with respect to a frame, wherein an air spring is expanded by injecting compressed air when the vehicle starts and a drive shaft tire. A vehicle start assisting device that increases the ground contact pressure of the vehicle. 4. A drive shaft mounted on a vehicle frame via a suspension, a bracket provided substantially parallel to the drive shaft with the frame, and an air spring mounted between the bracket and the frame. The suspension is provided with a leaf spring connected to the front end of a rocker arm whose front portion is supported by the frame and whose rear portion is rotatably supported by the frame, a drive shaft supported in the central portion of the leaf spring, and a rocker arm. A rocker arm type suspension having a driven shaft supported at a rear end portion thereof, characterized in that an air spring expands when compressed air is injected when the vehicle starts to increase a ground pressure of a drive shaft tire. Vehicle start assist device. 5. A drive shaft mounted on a vehicle frame via a suspension, a bracket provided substantially parallel to the drive shaft with the frame, and an air spring mounted between the bracket and the frame. The suspension includes a leaf spring supported by the frame, a walking beam whose central portion is rotatably supported with respect to the leaf spring, and a drive shaft and a driven shaft arranged at both ends of the walking beam. Is a walking beam type suspension including: a compressed air is injected into the suspension when the vehicle starts to extend, and the grounding pressure of the drive shaft tire is increased.