JPS63203473A - Turning mechanism for front wheel steering vehicle - Google Patents

Abstract

PURPOSE:To perform a turn with a small turning radius by making front wheels swayable to the right and left and making a front axle case itself swayable in the longitudinal direction. CONSTITUTION:A front axle case 4 is vertically swayably supported on a support frame 5 at its center section, and the said support frame 5 is horizontally rotatably supported on the lower face of the front section of a machine frame 1 by a rotary support shaft 6. A tie rod operating lever 10 is horizontally fitted to the upper face of the center section of the front axle case 4, the front extension section 10a of the said operating lever 10 is supported on the center section of a tie rod 9, and the left end of its rear lateral extension section 10b is interlocked and connected to a steering handle 14 of a steering mechanism D via a drag rod 11 and a pitman arm 12.

Description

[Detailed description of the invention] (b) Industrial application fields The present invention relates to a turning mechanism in a front wheel steering vehicle.

(b) Conventional technology and its problems Conventionally, as shown in Fig. 4, front wheels and rear wheels C are attached to the front and rear of the aircraft body a, and the front wheels are steered with a steering handle or the like. In vehicles, there is a restriction on the steering angle θ of the front wheels in order to avoid contact with the oil pan located in the center of the aircraft body a. Therefore, the turning center 0 of the turning radii R1 and R2 of the left and right front wheels also coincides with the rear wheels. Since the vehicle is located at a location spaced apart from the center C by a considerable distance CL in the width direction, the turning radii R1 and R2 become large, making it impossible to make sharp turns.

An object of the present invention is to provide a turning mechanism for a front wheel steering vehicle that can solve the above problems.

(d) Means for Solving the Problems The present invention has a central part of the front axle case that is pivotally supported on the aircraft body by a swinging support part so as to be able to swing freely in the longitudinal direction and the vertical direction. A front wheel steering vehicle, characterized in that a front wheel is pivotally supported at both ends so as to be swingable from side to side, and the swinging motion of the front axle case and the swinging motion of the front wheels are both linked to the steering operation of a steering mechanism. This relates to a turning mechanism.

(E) Actions and Effects With the above-described configuration, the present invention provides the following actions and effects.

■Not only can the front wheels be freely swung left and right at both ends of the front axle case, but the front axle case itself can also be swung back and forth, so even if the turning angle of the front wheels relative to the front axle case is restricted,
The apparent steering angle can be increased, making it possible to turn with a small turning radius by only slightly operating the steering mechanism.

■When turning, the turning angle of the front wheel can be increased by swinging the front axle case, so the turning angle of the front wheel relative to the front axle case can be reduced, which reduces the amount of dirt caused by the swinging of the front wheel. It is possible to reduce the amount of food being carried around, and it does not damage the field.

(f) Examples The present invention will be specifically described below based on examples shown in the attached drawings.

In FIG. 1, A is a tractor, and front wheels 2, 2 and rear wheels 3.3 are provided at the front and rear of the machine body l, respectively. Can perform turning operations.

In FIGS. 1 and 2, 4 is a front axle case disposed in the horizontal direction at the front of the fuselage 1;
The front axle case 4 has a support frame 5 at its center.
The support frame 5 is pivotally supported on the lower front surface of the machine frame 1 by a rotation support shaft 6 so as to be horizontally rotatable.

With this configuration, the front axle case 4 is pivotably supported in the vertical direction and in the longitudinal direction with respect to the fuselage l.

Furthermore, between the front axle case 4 and the fuselage l,
Although not shown, a return spring is interposed, and the return spring causes the front axle case 4 to be perpendicular to the axis χ-X of the tractor A as shown in FIG. 1 when no rotational force is applied. It is possible to assume a posture or position (Y-Y) that is stretched in the direction of

Further, the front axle case 4 pivotally supports the front wheel 2.2 via king pins 7.7 at both ends thereof so as to be swingable in the left-right direction.

Furthermore, around the kingpin 7.7, there is a knuckle arm 8,
8 is attached, and both knuckle arms 8.8 are connected by both ends of a tie rod 9 extending in the transverse direction parallel to the front axle case 4.

On the other hand, a tie rod operating lever 10 is mounted horizontally rotatably on the upper surface of the center portion of the front axle case 4, and the operating lever 10 pivots its forward extending portion 10a to the center of the tie rod 9. The left end of the rear horizontal frame extension portion 10b is operatively connected to a steering handle 14 of a steering mechanism via a drag rod 11 and a focusman arm 12.

With this configuration, when the steering wheel 14 is turned, the drag rod 11. Tie rod operating lever 10. The front wheel 2.2 can be rotated in the left-right direction around the king pin 7.7 via the tie rod 9 and the knuckle arms 8, 8.

Furthermore, in the present invention, an axle operation engagement part 15 is formed at the end of the rear horizontal frame extension part 10b of the tie rod operation lever 10 on the side that is not connected to the drag rod 11. A pair of S7 pars 17 and 18 are protrudingly provided on both sides of the joint portion 15 at locations forming the upper surface of the front axle case 4.

With this configuration, when the rotation angle of the tie rod operating lever 100 exceeds a certain level, the axle operating engagement portion 15 comes into contact with either of the stoppers 17 and 18, and when the tie rod operating lever 10 rotates further, the front axle case 4 It will rotate in the left and right direction around the rotation support shaft 6.

Next, the turning operation of the tractor A by the turning mechanism B having the above configuration will be explained with reference to FIG.

When it is necessary to cut only within a certain small angle range, such as during normal driving, even if the tie rod operating lever 10 is rotated via the drag rod 11, the axle operating engagement portion 1
5 does not come into contact with the stopper 17.18, only the front wheel 2.2 rotates in the left-right direction around the king pin 7.7 via the tie rod 9 and the knuckle arms 8, 8.

On the other hand, when it is necessary to turn the front wheels 2, 2 significantly, such as when turning, when the tie rod operating lever 10 is rotated via the drag rod 11, the axle operating engagement portion 15 comes into contact with the stopper 17, 18. First, the front axle case 4 is rotated left and right about the rotation support shaft 611q, and along with this rotation, the front wheels 2, 2 are also cut.

In this way, when turning, not only can the front wheels 2, 2 swing freely left and right at both ends of the front axle case 4, but also the front axle case 4 itself can swing back and forth, so that the front wheels 2. Even if the steering angle with respect to the front axle case 4 of 2 is restricted by the engine, oil pan, etc., the apparent steering angle α can be made large, making it possible to turn with a small turning radius by only slightly operating the steering mechanism. becomes.

That is, in FIG. 3, R1 and R2 indicate the turning radius of the left and right front wheels 2.2, and 0 indicates the turning center of the left and right front wheels 2.2.

As shown in the figure, since 0 is located at a small distance 12 from the center C of the left and right rear wheels 3.3, the turning radii R1 and R2 can be made extremely short.

Furthermore, when turning, the turning angle of the front wheels 2.2 can be increased by rocking the front axle case 4, so the turning angle of the front wheels 2, 2 relative to the front axle case 4 can be reduced. Front wheel 2.2
It is possible to reduce the movement of soil caused by the shaking of the soil, and the field will not be damaged.

Furthermore, as shown in FIG. 3, after fixing the front axle case 4 at a position cut at a certain angle α by a required locking means, by operating the rotary handle 14, the required oscillation can be achieved at the same angle α position. It is also possible to further cut the front wheels 2, 2 with the dynamic width β, or to soften the cutting angle.

Furthermore, when the steering force of the steering handle 14 is loosened, the front axle case 4 is moved by the action of the return spring.
The vehicle can assume a normal running posture as shown in FIG.

[Brief explanation of the drawing]

FIG. 1 is an explanatory view of the main parts of a front wheel steering vehicle equipped with a turning mechanism according to the present invention, FIG. 2 is a view taken along the line 1-I in FIG. FIG. 4 is an explanatory diagram of a conventional turning mechanism. In the diagram, A: Tractor B: Swing mechanism 2: Front wheel 3: Rear wheel 4: Front axle case

Claims (1)

[Claims] 1. Attach the center part of the front axle case (4) to the fuselage (1)
), and the front wheels (2
), (2) are pivotably supported in the left-right direction, and the swinging operation of the front axle case (4) and the front wheel (2),
A turning mechanism in a front wheel steering vehicle, characterized in that the swinging operation (2) is linked to the steering operation of the steering mechanism (D).