JPH057903Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a steering device for rear wheels of a vehicle with front and rear wheel steering.

(Prior art) A rotation take-off shaft provided on a front wheel steering device and a rotation input shaft of a rear wheel steering device are connected via a linkage shaft, and a pinion is freely rotatable on an eccentric shaft provided on the rotation input shaft. Along with mating,
A front and rear wheel steered vehicle is provided with an eccentric member integrated with the pinion, a joint member that connects and supports left and right rear wheel tie rods engaged with the eccentric member, and a fixed side internal ring gear with which the pinion meshes. , JP-A-58-97565 and JP-A No. 60-128080
It is known under No.

According to this, the maximum steering angle of the rear wheels is larger when the phase is opposite to that of the front wheels than when it is in the same phase as the front wheels. Moreover, the vehicle's turning performance at low speeds, which allows the steering wheel to be operated over a wide range of steering angles, is further improved.

(Problem to be Solved by the Invention) The gear ratio between the pinion and the internal ring gear is determined to be 3:4 based on the substantial steering range of the rear wheels, and the pinion shifts from the neutral steering position to the ring gear. In the process of revolving around the inner circumference of the ring gear, the steering direction of the rear wheels changes from the same phase as the front wheels to the opposite phase, and when the pinion has made 3/4 rotation around the inner circumference of the ring gear, the steering direction of the rear wheels changes from the same phase as the front wheels to the opposite phase. The rear wheel steering angle becomes maximum.

However, since the conventional structure allows the pinion to freely revolve around the ring gear, when the pinion revolves more than 3/4 rotation, the rear wheel steering angle decreases, and the steering angle of the rear wheel steering device becomes neutral. It also becomes difficult to determine the location.

(Means for solving the problem) In order to solve the problem, the present invention provides a rear wheel steering device of the type described above, in which the pinion 2 is
A pair of toothless portions 41 and protruding teeth portions 43 are provided between the meshing portions of the internal ring gear 4 and the internal ring gear 26 in a neutral steering state.

(Function) The pinion 24 moves from the steering neutral position to the ring gear 2.
When the pinion 24 rotates 3/4 around the inner circumference of the ring gear 6, in the embodiment, the pinion 24 interferes with the toothed portion 43 on the ring gear 26 side, so that over-rotation of the pinion 24 exceeding 3/4 rotation is prevented.

Furthermore, since the toothless portion 41 and the protruding tooth portion 43 mesh only when the rear wheels are in the neutral steering state, the neutral steering position of the rear wheel steering device can be easily determined on the assembly line or during maintenance. .

(Example) Examples will be described below based on the accompanying drawings.

Figure 1 is a schematic system diagram of the front and rear wheel steering device.
A steering shaft 2 of the handle 1 is connected to a pinion shaft 4 incorporated in a rack-pinion front steering gear box 3.
Both ends of the rack shaft 5 that engage with the tie rods 8 and the nutcle arms 7, 7 that support the front wheels 6,
Connected at 8. Furthermore, a pinion shaft 9 for taking out rotation, which is a shaft for taking out rotation for the rear wheel steering system, is provided which meshes with the rack shaft 5.

On the other hand, knuckle arms 12, 12 supporting the rear wheels 11, 11 are connected to both ends of a joint shaft 14 via tie rods 13, 13, and the joint shaft 14 is incorporated into a rear steering gear box 15. A rotation input shaft 16 is incorporated into the gearbox 15, and an eccentric shaft 17 is attached to the rotation input shaft 16.
The joint shaft 14 is provided with an engaging portion 18 that engages with the eccentric shaft 17 and receives only left-right movement.

The rotation extraction pinion shaft 9 and the rotation input shaft 16 are connected via a linkage shaft 19.

The details of the internal structure of the rear steering gear box 15 are as shown in FIGS. 2 and 3, and balls 21 are mounted on the eccentric shaft 17 provided on the rotary input shaft 16.
The cylindrical member 23 is rotatably fitted through the rollers 22 and the pinion 2 provided at the front of the cylindrical member 23.
4 meshes with an internal ring gear 26 made up of two front and rear layers fixed in the gear box 15, and a slide yoke 28 is relatively rotatable on an eccentric cam 25, which is an eccentric member provided at the rear of the cylindrical member 23, via balls 27. mated to. This slide yoke 2
8 is provided with tapered surfaces 281, 281 in the vertical direction on the left and right, and a roller is provided between each tapered surface 281, 281 and a similar tapered surface 181, 181 provided on the engaging portion 18 fixed to the joint shaft 14. 29...
is interposed. The rotation input shaft 16 is rotatably supported within the gearbox 15 via front and rear ball bearings 31, 31, and a distance collar 3 is provided between the outer rings of each ball bearing 31, 31.
2 is interposed.

In the initial setting of such a rear steering mechanism, for example, as shown in FIG.
The pinion 24 is engaged with the lowest part of the eccentric cam 25, and the top portion 251 of the eccentric cam 25 is directed vertically downward.

For example, if you turn the steering wheel to the right,
As shown in FIG. 6, the pinion 24 is connected to the ring gear 26.
The axes of the front steering and linkage mechanisms are configured so that the inner periphery revolves clockwise when viewed from the rear, and conversely revolves counterclockwise when the steering wheel is turned to the right.

In the above, the pinion 24 and the internal ring gear 26 are configured to have a gear ratio of 3:4, and the pinion 24 and the ring gear 26 have a pair of toothless portions 4 that mesh with each other as shown in FIG.
1 and a protruding tooth portion 43 are provided.

That is, as shown in FIG. 5, a toothless portion 41 is formed at the rear end of the lowest tooth of the pinion 24 in the neutral steering state, and the outer periphery of the rear end of this pinion 24 protrudes from the rear surface of the ring gear 26.

Then, on the rear surface of the ring gear 26, a ring plate 42 with the inner diameter of the bottom circle of the ring gear 26 is attached with screws 45, 45.
Conclude at. A protruding toothed portion 43 that includes the toothless portion 41 of the pinion 24 and engages between the teeth on both sides thereof is provided at the lowest inner periphery of the ring plate 42 .

Since the pair of toothless portions 41 and protruding teeth portions 43 that mesh only in the neutral steering state are provided, the pinion 24 moves 3/4 of the way from the neutral steering position to the inner periphery of the internal ring gear 26, as shown in FIG. When the pinion 24 performs the revolution, the pinion 24 rotates one rotation. Then, when the pinion 24 tries to revolve further, the pinion 24 butts against the protruding tooth part 43 located at the bottom of the ring gear 26, and since the pinion 24 cannot get over the protruding tooth part 43, further revolution is prevented. .

Further, on the assembly line or during maintenance, the toothless portion 41 and the protruding tooth portion 43 are engaged to align the pinion 24 and the internal ring gear 26, so that the neutral steering position can be easily determined.

Incidentally, the toothed portion 43 may be formed directly on the ring gear 26, or the toothless portion 41 may be formed directly on the ring gear 26.
6, the same effect can be obtained by forming the toothed portions 43 on the pinion 24 respectively.

(Advantages of the Invention) As described above, according to the present invention, the pair of missing teeth portions and the protruding teeth portion can prevent over-rotation of the pinion relative to the internal ring gear,
In addition, the neutral steering state can be easily determined.

[Brief explanation of drawings]

Fig. 1 is a schematic system diagram showing an example of a front and rear wheel steering device, Fig. 2 is a cross-sectional view of the inside of the rear steering gear box, Fig. 3 is a longitudinal sectional view of the same, and Fig. 4 is a perspective view of the pinion and ring gear parts. , FIG. 5 is a perspective view of the toothless portion, and FIG. 6 is a rear view of the pinion and ring gear portion. In the drawings, 1 is a handle, 3 and 15 are steering gear boxes, 6 is a front wheel, 9 is a rotating shaft, 11 is a rear wheel, 14 is a joint member, 16 is a rotating input shaft, 17 is an eccentric shaft, and 19 is a rotating shaft. A linkage shaft, 24 is a pinion, 25 is an eccentric member, 26 is an internal ring gear, 41 is a toothless portion, 42 is a ring plate, and 43 is a toothed portion.

Claims (1)

[Scope of Claim for Utility Model Registration] A rotation take-off shaft provided on a front wheel steering device and a rotation input shaft of a rear wheel steering device are connected via a linkage shaft, and a pinion is mounted on an eccentric shaft provided on the rotation input shaft. In addition to being rotatably fitted, an eccentric member is provided integrally with the pinion, and a joint member that connects and supports left and right rear wheel tie rods is engaged with the eccentric member, while a fixed side internal ring gear is engaged with the pinion. A rear wheel of a front and rear wheel steered vehicle, characterized in that a pair of toothless portions and a protruding tooth portion are provided between the meshing portions of the pinion and the internal ring gear in a neutral steering state. steering device.