JPS6334071B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a front wheel distance adjustment device for a work vehicle such as a tractor.

Generally, the front wheels 2 of the tractor 1' are set to a predetermined wheel width 1 to match the crop row width, as shown in FIG. 1, but as shown in FIG.
The steering angle of the front wheels 2 is limited so as not to interfere with the body 5 during front wheel steering, resulting in a large turning radius of the tractor.

Therefore, the present invention provides the kingpin with an arm connected to the steering device, and is configured so that the position of the kingpin can be moved as the arm rotates. It is an object of the present invention to provide a front wheel wheel distance adjustment device that automatically increases the front wheel steering angle and reduces the turning radius.

Embodiments of the present invention will be described below with reference to FIGS. 3 to 7.

As shown in FIG. 3, the tractor 1 has a body 5 supported by front wheels 2 and rear wheels 3, and the rear of the body 5 has a steering handle 6.
The driver's seat 7 has a And front wheel 2
has a front axle 9, as shown in FIGS. 4 to 6.
consists of an outer 9a suspended from the fuselage 5 and an inner 9b fitted telescopically at both ends of the outer. Further, a king pin holder 10 is fixed to the inner 9b, and a king pin 11 is rotatably supported on the holder 10. A front wheel 13 is attached to the kingpin 11 via an axle 12, and a bell crank-shaped arm 15 is attached to the upper part of the holder 10.
is permanently installed. The arm 15 has one end 15a
The tie rod 16 that makes up the steering device is connected to pin 1.
7, and a link 20 is connected to the other end 15b via a pin 19.
The link 20 constituting the connecting member is swingably disposed on the front axle outer 9a via a pin 21, and as shown in FIG.
In the straight-ahead state, pins 21, 19 and king pin 1
They are arranged so that the center points of 1 are located on a straight line.

Since this embodiment has the above configuration, when the tractor 1 is traveling straight, the link 20 is aligned with the front axle 9 as shown in FIG. 6, that is, the pins 21, 19 and the king pin 11 are aligned in a straight line, the king pin 11 is in the position where the front axle inner 9b is retracted, and the wheel width of the front wheel 2 is as shown in FIG. The distance is set to 1, which is the same as . Then, by operating the steering handle 6, as shown in FIG.
When tie rod 16 is pushed in the direction of arrow A, arm 1
5 rotates around the center point of the king pin 11, rotates the front wheel 13 by a predetermined angle in the direction of arrow B via the king pin 11 and the axle 12, and turns the tractor 1. At this time, the other end 15b of the arm 15 is connected to the pin 1.
Since the pin 19 is connected to the link 20 via the link 9, the pin 19 is restricted to move in a radius R centered on the pin 21, and therefore, as the arm 15 rotates, the king pin that serves as its fulcrum moves. 11 is moved outward by a predetermined amount Z. As a result, the front axle inner 9b moves in the direction of arrow C, and as shown in FIG. By rotating in the opposite direction, the center
The front wheel 2 is moved by a predetermined amount Z from D' to E', and the wheel width of the front wheel 2 is widened to a distance L.

In the above embodiments, the present invention is applied to the tractor 1, but it goes without saying that the present invention may also be applied to other working vehicles such as agricultural vehicles and construction vehicles.

As explained above, according to the present invention, when the vehicle 1 is traveling straight, the wheel distance 1 is maintained as in the conventional case, but when the vehicle is turning, the wheel distance L of the front wheels 2 is automatically widened. 2, the steering angle can be made large without interfering with the aircraft body 5, the turning radius can be made small, and workability can be improved. In particular, in a four-wheel drive tractor or the like, the steering angle is further restricted for the front wheels 2 equipped with large-diameter front wheels 13, but by applying the present invention, it is possible to reduce the turning radius. .

[Brief explanation of the drawing]

Figure 1 is a front view of a conventional tractor; Figure 2 is a front view of a conventional tractor;
3 is a plan view showing a tractor to which the present invention is applied, FIG. 4 is a plan view showing its front wheels, FIG. 5 is a perspective view showing the main parts, and FIG.
The figure is an enlarged plan view in the straight-ahead state, and FIG. 7 is a plan view in the turning state. 1...Work vehicle (tractor), 2...Front wheel, 5
...Fixed member (airframe), 9...Front axle,
9a...Outer, 9b...Inner, 11...
King pin, 13...front wheel, 15...arm,
16... Steering device (tie rod), 20... Connection member (link).

Claims (1)

[Claims] 1. In a work vehicle having a front wheel consisting of a pair of left and right front wheels that are supported by a front axle and can rotate around a king pin, the front axle is composed of an outer and an inner that is telescopically supported at both ends of the outer. The inner supports a kingpin, and the kingpin is provided with an arm connected to the snake remover, and the arm is connected to a fixed member such as the outer through a connecting member, and the arm is rotated. A wheel distance adjustment device configured to be able to move the position of the kingpin as the vehicle moves.