JPS60193777A - Rear-wheels steering apparatus - Google Patents

Abstract

PURPOSE:To simplify structure by pivotally installing a radial rod and a torque rod which are connected onto a differential case, onto a chassis through an elastic body and steering a rear axle by elastically deforming the above-described elastic body by an actuator, thus eliminating the necessity of a neutral fixing means. CONSTITUTION:Each one edge of two pairs of a radial rod 12 and a torque rod 13 at right and left is connected, having a differential gear part 11 interposed. The other edges of these rods 12 and 13 are connected to a chassis 14 side. In the installation part, the installation eye 18 of each rod 12, 13 is fitted through a rubber bush 17 and a sleeve 16 onto a connecting pin 15 projecting from the chassis 14. A rear-wheel driving shaft 10 is turned horizontally around a center point by properly deforming each rubber bush 17 by each hydraulic cylinder 20. When the working oil in the hydraulic cylinder 20 is returned into a tank, the rubber bush 17 restores elasticity, and the rear-wheel driving shaft 10 is kept in the straight-advance state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a rear wheel steering device, and particularly to a rear wheel steering device suitable for application to a vehicle with a long wheel pace such as a large vehicle.

[Background of the invention]

In general, large vehicles such as buses have two rear axles, but rear wheel steering is used because the tires on the driven axle in particular suffer from severe tire wear and have poor steering performance, such as a narrow turning radius. There are known devices that allow this.

Figures 1 and 2 show a conventional rear wheel driven shaft 1 with a steering function.A steering cylinder 4 is installed between the rear wheel driven shaft 1 and the knuckle arm 3 of the rear wheel 2. A desired steering angle can be obtained by the telescoping motion.

However, providing the above structure with a steering function has a problem in that it also requires a locking mechanism to fix the steering device in a neutral position when traveling straight. This is because, since the resistance element during the steering operation is removed, there is a risk that an arbitrary steering operation may occur at the same time and vibration may occur. This locking mechanism is for axle 1
A support piece 5 is projected from the wheel 2 and a pin 6 is inserted and connected. However, such a structure requires a loading device for the bin 6 and a pin hole positioning device, and has drawbacks such as the need to perform operation operations and pin insertion operations frequently.

[Purpose of the invention]

The present invention has focused on the above-mentioned conventional problems, and an object of the present invention is to provide a ring steering device that has an extremely simple structure and does not require means such as neutral fixation.

[Overview of the invention]

In order to achieve the above object, the rear wheel steering device according to the present invention provides a rear wheel steering device that rotates the vehicle in the longitudinal direction with respect to the elastic body attached to the end of several examples of the rod member installed between the vehicle rear wheel axle and the vehicle body. An actuator is provided to provide elastic deformation, and the actuator is operated to horizontally rotate and steer the rear wheel axle within the range of the deformation of the elastic body.

With such a configuration, for example, the rubber bush, which is an elastic body attached to the attachment end of the radius rod as a rod member, is elastically deformed by the expansion and contraction movement between the rod and the vehicle body by the hydraulic cylinder as an actuator, so this deformation movement is controlled by the axle. It can be extracted as a rotation in the horizontal plane. As a result, the rear wheels can be steered by applying a couple motion to the left and right elastic bodies. If the hydraulic cylinder is made free, it functions as a normal support rod, so no neutral position locking means is required.

[Embodiments of the invention]

The rear wheel steering device of the present invention will now be described in detail with reference to FIGS. 6 to 4.

FIG. 6 is a plan view in which the steering device of the present invention is applied to the rear wheels, particularly the drive shaft 10. As shown in the figure, this rear wheel drive shaft 10
has a differential gear part 11, and a pair of left and right radius rods 12 and a torque rod 16 are connected with the gear part 11 in between, and the other ends of the rods 12 and 15 are connected to the vehicle body 14 side. The radius rod 12 is attached to support forces in the longitudinal direction, and the torque rod 15 is attached to support tramping, etc., so a rubber bush 17 is provided at its attachment portion. This specific structure is shown in FIG. 4 for the mounting portion of the two-diameter rod 12 on the vehicle body 14 side. A connecting pin 15 protrudes from the vehicle body 14, a sleeve 16 is fitted onto the pin 15, and the sleeve 16 is fitted onto the pin 15.
A shiver bush 17 is attached to the outer periphery of the holder. A mounting eye 1B of the radius rod 12 is attached to the rubber bush 17. This mounting structure allows each rod to
2.150 It is said that it is the same at both ends.

For such a rear axle device, the embodiment includes each rod 12.
A hydraulic cylinder 20 as an actuator is installed between a 1" l mounting eye 18 and the vehicle body 14. This hydraulic cylinder 20 has its cylinder 21 end connected to the vehicle body 14, and the piston rod 22 is connected to the vehicle body 14 in some cases. connected to 18,
It is arranged so that the direction of expansion and contraction is within the horizontal plane. This is the same for each rod 12.1'3, and all are attached facing the same direction in the longitudinal direction of the vehicle. The hydraulic cylinder 20 is arranged so that the expansion and contraction movement of the hydraulic cylinder 20 causes elastic deformation of the bushing 17 in the horizontal direction.The hydraulic cylinder 20 is connected to a hydraulic circuit of a power steering system, for example, and is connected to a differential. Gear part 1
A circuit is constructed so that both hydraulic cylinders 20 on one side separated by sandwiching 1 operate synchronously, and the hydraulic cylinders 20 between the left and right sides operate in opposite directions.

The operation of the steering device according to this configuration is as follows. If the rear wheel drive shaft 10 is to be steered in accordance with the right turn, the rear wheel drive shaft 10 must be horizontally rotated clockwise in FIG. 5. At this time, hydraulic pressure is applied to both the upper hydraulic cylinders 20 in the drawing to apply extension thrust, and to the lower hydraulic cylinder 20 to apply contraction thrust. This action causes the rubber bushing 17, which is an elastic body, to release the sleeve.

16 and the eye 18. As a result, since the left and right hydraulic cylinders 20 operate in opposite directions, the rear wheel drive shaft 10 receives a couple of turns of the center vertical line A of the differential gear section 11, and the horizontal rotation angle is equal to the deformation value of the rhino (-button) 17. Then, when the supply to the hydraulic cylinder 20 is stopped and the hydraulic oil is returned to the tank, the bushing 17 recovers elastically and returns to the normal supporting state, that is, the rear wheel drive shaft 10. The rods 12 and 130 are held perpendicular to the longitudinal direction of the vehicle and perform their assigned functions.

According to this embodiment, the hydraulic cylinder 2 provides elastic deformation in the longitudinal direction of the vehicle to the rubber bush 17 attached to the rod 12.13 interposed between the rear wheel drive shaft 10 and the vehicle body 14.
It is only necessary to attach it to the 0 position, and it is possible to steer the rear 1-piece with a very large number of parts. Moreover, the hydraulic cylinder 20
Just by leaving it free, the rod 12.1 has the same mounting structure as before, so the rubber bush 17 can be fixed and held in the neutral position without any special measures. The same is achieved.

FIG. 5 shows another embodiment in which the mounting structure of the hydraulic cylinder 20 is such that one end is connected to the vehicle body 14 and the other end is connected to the middle of the busy rod 12 (■), and one end is connected to the rear wheel drive shaft. 10 shows an example (n) in which the other end is connected to the eye 26 on the axle side of the rod 12.

In this embodiment as well, the same effects as in the previous example can be obtained.

〔Effect of the invention〕

As explained above, according to the present invention, the rear wheel steering function can be achieved simply by utilizing the elastic deformation of the elastic body conventionally used in the rod connection part and installing an actuator that provides this elastic deformation. Since the neutral position holding function can be exhibited, it is possible to provide an effective rear wheel steering device with an extremely simple structure.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a conventional rear wheel steering device, FIG. 2 is a view taken along the line TI-n in FIG. 1, FIG. 5 is a plan view of an embodiment of the rear wheel steering device, and FIG. The figure is an enlarged sectional view taken along the line IV'-1v in FIG. 5, and FIG. 5 is a modified layout of the hydraulic cylinder. DESCRIPTION OF SYMBOLS 10... Rear wheel drive shaft, 12... Radius rod, 15... Torque rod, 17... Rubber bush, 20... Hydraulic cylinder. Agent Tatsuyuki Unuma (and 1 other person) Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 0) An actuator is provided that causes elastic deformation in the vehicle longitudinal direction to an elastic body attached to the attachment end of a rod member attached between the rear wheel axle of the vehicle and the vehicle body, and when the actuator operates, the elastic body A rear wheel steering device whose characteristic is to horizontally rotate the rear wheel axle within a range of deformations.