JPH023574A - Front wheel steering angle adjusting device for tractor - Google Patents

Abstract

PURPOSE:To aim at the smoothness of running while turning by dividing a front wheel axel supporting part into a knuckle arm part and a front wheel fixing part in a changeable front wheel tread so as to enable to alter the relative angle between a knuckle arm and a drag link. CONSTITUTION:A king pin 9 is fixed on both sides of a front axel housing 7 which is stretchable in the crosswise direction in the fixed range, a front wheel axel supporting part 10 is shiftably provided in the crosswise direction. A knuckle arm 11 for steering is protrusively provided at the axel supporting part 10 of each front wheel, and the right and left knuckle arms 11, 11 are connected to the front end part of a crank formed pitman arm 12 through a drag link 13. The front wheel axel supporting part 10 is divided into the upper and lower parts, that is, a knuckle arm part 17 and a front wheel fixing part 18 both separately turnable, and the angle between the drag link 13 and the knuckle arm 11 can be adjustable in several stages by the alteration of the inserting position of a bolt 26 to holes 22-24.

Description

[Detailed Description of the Invention] Field of Industrial Application] This invention relates to a front wheel steering angle adjustment device for a tractor, and in particular, to a front wheel steering angle adjusting device for a tractor, and in particular, a device that can change the front wheel tread and smoothly perform the steering operation. This invention relates to a front wheel steering angle adjustment device for a tractor.

[Prior art] When changing the tread depending on the work in a conventional tractor whose front wheel tread can be changed, the front axle housing is expanded and contracted in the left-right direction and fixed at an appropriate width, and the pitman arm and front wheel TJi shaft support are fixed. The drag link that connects the knuckle arm, which is fixed to the part, was adjusted to the appropriate length. Therefore, when turning, the steering angle difference between the turning side and the outer front wheels is approximately constant regardless of the tread. Therefore, especially when turning with a small radius with the tread expanded, the turning radii of the inner and outer front wheels are considerably different, so the steering angle of the outer front wheels becomes larger than necessary, resulting in side slip. The vehicle turned around and running resistance increased. This will be explained with reference to FIG. 4 of the attached drawings. In the figure, (+) indicates the left rear wheel, and (2) indicates the left front wheel. This figure shows a state in which the left rear wheel (1) is braked and the left front wheel (2) is turned 90 degrees to the left in order to turn left as the turning center. Also, the front right wheel has a narrowed tread (3a) and an enlarged tread (3b).
), and the grounding point (4) of the left rear wheel (+), which is the center of rotation, and the right front wheel (3a) (
3b) in the direction perpendicular to the straight line connecting the grounding points of
5a) (5b) can be expressed. However, since the steering angle of the left and right front wheels (2) and (3) is - between the roads, the right front wheels (3a and 3b) are turned by nearly 90 degrees as shown by the solid line, and the steering angle is greater than the direction of travel shown by the chain line. The tractor turns while slipping in the lateral direction. However, the difference between the traveling direction and the actual steering angle increases as the tread becomes wider.

[Problems to be Solved by the Invention] As mentioned above, in conventional tractors whose treads can be changed, the steering angle difference between the left and right front wheels is approximately constant regardless of the tread. The side front wheels cut through rather than in the actual direction of travel, and the angular difference with the direction of travel increases, increasing running resistance. Further, as the turning radius becomes smaller, this angular difference becomes larger, so it has been difficult to turn the tire smoothly when working with the tread enlarged. Therefore, a technical problem has arisen that needs to be solved in order to bring the steering angle of the turning outer front wheel as close as possible to the actual direction of travel regardless of the tread, and the purpose of this invention is to solve this problem. That is.

[Means for Solving the Problems] The present invention was proposed to achieve the above object, and provides a front wheel axle support system for a tractor whose tread can be changed by expanding and contracting the front axle housing in the left and right directions. The part is divided into a steering knuckle arm part and a front wheel mounting part, which are rotatably joined to each other, and connecting protrusions are provided facing each other on the upper and lower sides of the outer periphery of the joint surface, and the protrusions are A front wheel rudder for a tractor, characterized in that a plurality of bolt insertion holes are drilled in one piece, and the mounting angle of a knuckle arm relative to the front wheel axle can be adjusted when the bolts are inserted into the holes and connected. It is an object of the present invention to provide a gripping angle adjusting device.

[Operation] In this invention, the cylindrical front wheel axle support part, which is rotatably pivoted to king pins fixed to both sides of the front axle housing, is divided into two parts: an upper knuckle arm part and a lower front wheel mounting part. . The lower end of this knuckle arm portion and the upper end of the front wheel mounting portion are in contact with each other, and projecting pieces are provided on the lower end of the outer periphery of the knuckle arm portion and the upper end of the outer periphery of the front wheel mounting portion, respectively, so as to make sliding contact. are doing. A plurality of bolt insertion holes are drilled downward in the projecting piece of the knuckle arm portion, and the bolt insertion holes are arranged in an arc shape so as to be equidistant from the center of rotation. Further, a bolt insertion hole is formed in the protrusion of the front wheel mounting portion that slides in contact with the protrusion, and any of the bolt holes of the knuckle arm portion can be matched with the bolt insertion hole. . Therefore, when the tractor turns, the required steering angle differs due to the difference in turning radius between the inner and outer front wheels, and the larger the tread and the smaller the turning radius, the larger the required steering angle difference becomes. .

On the other hand, the farther the angle between the knuckle arm and the drag link is from a right angle, the greater the steering angle difference between the left and right front wheels becomes. Therefore, when changing the tread, select the bolt insertion hole in the knuckle arm part so that the knuckle arm is at an appropriate angle with respect to the drag link, match it with the bolt insertion hole in the front wheel mounting part, and connect it with bolts and nuts. . In such a case, the steering angle of the turning outer front wheel can be made to correspond to each tread, and it is possible to smoothly turn the outer front wheel without causing the outer front wheel to skid when turning.

[Embodiment] Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 3 of the attached drawings. For convenience of explanation, conventionally known techniques will also be explained at the same time. In FIG. 1, (6) is a tractor. On both sides of the front axle housing (7) (7), which can be expanded and contracted within a certain range in the left-right direction, there are king pins (9) that serve as the center axis of rotation of the front wheels (8) (8).
)(Q) is fixedly installed. The Kingpin (Q) (9)
A front wheel axle support part Qo) Qo) is pivotally attached to the front wheel axle support part Qo) so as to be freely rotatable in the left-right direction, and the front wheels (8) (8) are mounted on the axle (not shown) of the front wheel axle support part (In) (10). It is attached to the shaft.

In addition, steering knuckle arms (II) (It) are protruded forward from the front wheel axle support part Qn)Qn), and these left and right knuckle arms (1000 are disposed at the front central part of the tractor (6)). The front ends of the crank-shaped pitman arms θ are connected via drag links 03) and 03), respectively. One end of the pitman arm (+21 has a tie rod 04 at the other end) is pivotally connected to the other end, and the other end of the tie rod ω is pivotally connected to the steering gear box 0,
The rotational movement of the steering wheel (1G) is transmitted to the pitman arm (+21).Thus, the rotational movement of the steering wheel (10) is converted to the longitudinal movement of the tie rod CJ/I, and the ) is pivoted at the end of the pitman arm 0ri, which is pivoted to the left and right around the rotation axis (12a).In that case, it is connected to the pitman arm 02) via a drag link 03)03). The knuckle arms (I+) (I+) are also interlocked, and the front wheel axle support part (In) (10) on which the knuckle arms 0000 are protruded is rotated about the king pins (9) (9).

As shown in Fig. 2, this front wheel axle support part (10) (+(1) is formed into a knuckle arm part (β7) and a front wheel mounting part (divided into upper and lower halves so that they can be rotated separately). Then, protrusions (A) are provided on the outer periphery of the contact surfaces of the knuckle arm part (B) and the front wheel mounting part (A), respectively, so that the protrusions (A) slide into contact with each other. At this point, drill a bolt insertion hole G!O in the vertical direction in the front wheel mounting part (the protrusion (G)), and insert the bolt insertion hole G! Therefore, in this embodiment, three bolt insertion holes @ (C) are drilled, but this number should not be limited to this. ) is placed on an arc centered on the rotation center axis (c),
All of them can be matched with the bolt insertion holes (21) drilled in the front wheel mounting part (the projecting piece (A)). Therefore, the three bolts of the knuckle arm part (β7) Align any one of the insertion holes @ (c) and (b) with the front wheel mounting part (the bolt insertion hole (21)), insert the bolt (1), screw the nut H'/), and tighten. Then,
Upper knuckle arm part (β7) and lower front wheel mounting part (
(g) can be combined to perform steering operations. Furthermore, by selecting the bolt insertion hole @(2) (b) of the knuckle arm portion (b), the angle formed by the drag link 0■ and the knuckle arm 00 can be changed in three steps.

The effect when the knuckle arm angle is changed as the tread of the tractor is changed will be explained with reference to FIG.

In the same figure, (1'3 is the pitman arm, (I■
indicates a drag link, and (11) indicates a knuckle arm.

Here, when the tread is at the minimum TOOmm, the knuckle arm (11) faces the outermost side with respect to the traveling direction (the above-mentioned bolt insertion hole (toward) is selected).

For example, when turning to the right, the knuckle arm (11) turns clockwise in the figure to the lock position, and the turning angle is β1. At this time, the rotation angle of the left front wheel (not shown) is represented by α1, and the angular difference between α1 and βl is the steering angle difference between the inner and outer front wheels. In the conventional example, the angle between the knuckle arm and the front wheel does not change even if the tread is extended, so the steering angle difference is always constant. On the other hand, in this embodiment, when the tread is extended, the knuckle arm 00 can be adjusted with the bolt insertion hole so that it moves inward, so when the tread l is 300 mm, the bolt insertion hole (b) and the front wheel can be adjusted. If the mounting parts (bolt insertion holes G!1 on the peaks) are aligned and connected with bolts, the steering angle β3 of the front wheel on the inside of the turning side will be slightly smaller than the above β1, but the steering angle of the front wheel on the outside side of the turning side will be slightly smaller. The angle α3 is considerably smaller than the above-mentioned α1, and as a result, the steering angle difference between the inner and outer wheels becomes large. Therefore, when turning with the tread widened, the steering angle of the outer front wheels is close to the actual direction of travel, and there is no risk of increased running resistance.

Effects of the Invention: As detailed in the above-mentioned embodiment, the present invention has a structure in which the front wheel axle support part is divided into a knuckle arm part and a front wheel mounting part so that the relative angle between the knuckle arm and the drag link can be changed. Therefore, by changing the angle, it is possible to adjust the steering angle difference between the inner and outer front wheels when turning, so the required steering angle difference due to the size of the tread can be reduced in tractors that can extend and retract the tread. Able to respond to change.

In the conventional example, when the tread was extended, the angle difference between the steering angle of the turning outer front wheel and the direction of travel became large, and the wheel turned while slipping laterally, but in the present invention, this is not the case. Since the angular difference can be made small, running resistance during turning can be reduced. Therefore, this invention is capable of exhibiting various effects, such as smooth turning running, reduced loads on the outer front wheels and axles, and improved durability.

Therefore, this invention can be modified in various ways without departing from the spirit of the invention, and it goes without saying that this invention extends to such modifications.

[Brief explanation of the drawing]

Figures 1 to 3 show one embodiment of the present invention, with Figure 1 being a plan view of the tractor, Figure 2 being a partially cutaway perspective view showing the main parts, and Figure 3 showing the operating state of the main parts. Explanatory diagram, FIG. 4 is an explanatory diagram showing the operating state of the conventional example.

Claims (1)

[Claims] In a tractor whose tread can be changed by expanding and contracting the front axle housing in the left-right direction, the front wheel axle support part is divided into a steering knuckle arm part and a front wheel mounting part, which are joined together so as to be rotatable; When coupling protrusions are protruded from above and below the outer periphery of the surface, and a plurality of bolt insertion holes are drilled in the protrusions to allow bolts to be inserted and coupled,
A front wheel steering angle adjustment device for a tractor, characterized in that the attachment angle of a knuckle arm with respect to a front wheel axle can be adjusted.