JPH0531019Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The invention provides a pair of left and right front wheels and a pair of left and right rear wheels that can be freely steered.
The pair of left and right front wheels and the pair of left and right rear wheels are configured to steer the pair of left and right rear wheels in a direction opposite to the steering direction of the pair of left and right front wheels in accordance with the steering operation of the pair of left and right front wheels. The present invention relates to a steering system for a working vehicle which is connected to a reversing link mechanism.

[Conventional technology]

Conventionally, in such a steering device for a work vehicle,
As shown in FIG. 6, one end of a rear steering arm 22 is connected to a steering relay rod 21 that converts rotational operating force into a push-pull motion in a steering gear box 20, and a rear steering arm 22 that further converts the push-pull motion into a rocking motion. A pair of rear tie rods 23, 23 connected to the left and right from this rear steering arm 22 are connected to rear knuckle arms 24, 24 of the rear wheels 2a, 2b, respectively.
It constituted a reversing link mechanism A.

[Problem that the invention attempts to solve]

The reversing link mechanism A includes a steering relay rod 21 that extends diagonally from a steering gear box 20 located at the center of the aircraft body, a rear steering arm 22 that is long in the left and right direction and connected to this steering relay rod 21, and this rear steering arm 22. Since it is wide in the width direction of the fuselage, consisting of the rear tie rods 23, etc. that extend from the rear tie rods 23 toward the left and right ends, the installation of various devices originally installed on the fuselage is restricted by the reversing link mechanism A. It was hot.

In addition, when installing the reversing link mechanism A, in order to bypass the rear steering arm 22 that interferes with the fuselage frame 9, the reversing link mechanism A is installed.
must be placed below the fuselage frame 9, the ground clearance of the aircraft is substantially lowered, and it is difficult to secure space between the front and rear wheels for installing a mid-mount type working device. It was hot.

The purpose of this invention is to avoid restrictions on the installation of various devices that are originally equipped on the aircraft.
Another point is that the substantial ground clearance between the front and rear wheels of the aircraft body can be increased.

[Means for solving problems]

In order to achieve the above object, the steering device for a working vehicle according to the present invention has the above-mentioned structure, and a steering gear box is disposed between a pair of left and right frame members constituting the body frame. A Pittman arm is provided on the steering gear box so as to be movable back and forth in a state extending laterally and outwardly, and the reversing link mechanism is
The reversing link mechanism is interposed between the pitman arm for steering the pair of left and right front wheels and the rear wheel along the frame material located on the same lateral side of the aircraft. The characteristic configuration is that it is arranged within the vertical width of the fuselage frame when viewed.

The functions and effects of this characteristic configuration are as follows.

[Effect]

In other words, the reversing link mechanism is arranged on one side of the fuselage by connecting the pitman arm and the rear wheel on the same side as the pitman arm, which is located laterally outward than the fuselage frame. Since it can be placed along the frame material, it can be installed in structures such as various devices that are originally installed between the left and right pair of frame materials in the aircraft frame. The reversing link mechanism does not get in the way.

Further, since the reversing link mechanism can be arranged on one side of the fuselage, the reversing link mechanism can be arranged so as to fit within the vertical width of the fuselage frame.

[Effect of idea]

Therefore, by arranging the reversing link mechanism as described above, it is possible to avoid restrictions on the installation of various equipment originally equipped, and the reversing link mechanism also makes it possible to To provide a working vehicle that suppresses the actual ground clearance between the front and rear wheels from being lowered, facilitates the installation of mid-mount type work equipment, etc., and is advantageous in terms of production and use. Now I can do it.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings.

As shown in FIG. 5, a pair of left and right front wheels 1a,
1b, a pair of left and right rear wheels 2a, 2b, a steering handle 3, etc., and a lawn mowing device 4 as a mid-mounted working device is connected to the middle part of the traveling body to be able to be raised and lowered to form a riding lawn mower. There is.

The front wheels 1a, 1b and the rear wheels 2a, 2b
is configured to be freely steerable by the steering handle 3, and its configuration will be described below.

As shown in FIGS. 2 to 4, a steering gear mechanism 7 consisting of a small-diameter gear 7a and a large-diameter gear 7b provided in a steering gear box 6 is attached to a rotating shaft 5 interlockingly connected to the steering handle 3. The Pitman arm 8 is interlocked via. The tip side of this Pittman arm 8 is connected to a pair of left and right frame members 9 that constitute the fuselage frame 9.
The Pitman arm 8 of B and 9B is made to protrude laterally outwardly through a through hole 9A formed in the extending frame member 9B, and a front steering relay rod 1 is attached to the tip of the Pitman arm 8.
0 to the front knuckle arm 11a of the left front wheel 1a, and connects the free end of the front knuckle arm 11a and the front knuckle arm 11b of the right front wheel 1b to the front tie rod 12. The front wheels 1a and 1b are configured to be able to be steered by rotating the steering handle 3 by interlocking and connecting the front wheels 1a and 1b.

Further, as shown in FIGS. 1 and 2, the vertical width of the fuselage frame 9 is the same as the vertical width of the fuselage frame 9 when the end of the pitman arm 8 and the left rear wheel 2a located on the same side of the fuselage are viewed from the side. The rear knuckle arms 1 of the pair of left and right rear wheels 2a, 2b are interlocked and connected by a reversing link mechanism A disposed inside.
3a, 13b are linked together by a rear tie rod 14, and as the pair of left and right front wheels 1a, 1b are steered by the steering handle 3, the pair of left and right rear wheels 2a, 2b are connected to the pair of left and right front wheels 1a, 1b. The steering wheel is configured to be able to be steered in a direction opposite to the steering direction of the steering wheel.

The reversing link mechanism A includes a rear steering relay rod 15 connected to the Pitman arm 8 and extending along the longitudinally long frame member 9B, and an L that changes the pushing and pulling motion of this rod 15 into rocking motion. It consists of a letter-shaped swinging arm 16, and a first link 17 and a second link 18 that transmit the swinging motion of the swinging arm 16 to the left rear knuckle arm 13a.

FIGS. 4A, 4B, and 4 show the rear wheels 2a, 1b, and 2a, respectively, with respect to the front wheels 1a, 1b, which are steered as the steering handle 3 is rotated.
2b shows the steering operation position. In other words, when the front wheels 1a and 1b are steered to the right,
As shown in FIG. 4A, when the rear wheels 2a and 2b are steered to the left, and when the front wheels 1a and 1b are steered to go straight, as shown in FIG. , 2b are similarly steered to go straight ahead, and when the front wheels 1a, 1b are steered to the left, the rear wheels 2a, 2b are steered to the right as shown in FIG. 4C. It is.

[Another Embodiment] In the above embodiment, the reversing link mechanism A is disposed on the left lateral side, but it may be disposed on the right lateral side.

Further, in the above embodiment, as the front wheels 1a, 1b are steered to one side, the rear wheels 2
Although the configuration is such that the front wheels 1a, 2b are steered in the opposite direction to the steering direction of the front wheels 1a, 1b, the rear wheels 2a, 2b are steered in the same direction until the front wheels 1a, 1b are steered with the set accuracy. and the front wheel 1
It may be configured such that the rear wheels 2a, 2b are steered in the opposite direction from the time when the wheels a, 1b are steered beyond a set angle.

The present invention can be applied not only to riding lawn mowers but also to various types of work vehicles such as tractors.

Incidentally, although reference numerals are written in the claims section of the utility model registration for convenience of comparison with the drawings, the present invention is not limited to the structure of the attached drawings by such entry.

[Brief explanation of drawings]

The drawings show an embodiment of the steering device for a working vehicle according to the present invention, and FIG. 1 is a schematic plan view showing the specific structure of the steering device, and FIG. 2 is a partial cutaway showing the mounting structure of the reversing link mechanism. 3 is a longitudinal sectional view of the steering gear box, FIG. 4 is a schematic plan view showing the steering status of the rear wheels, and FIG. 5 is an overall side view of the riding lawn mower. . FIG. 6 is a schematic plan view showing the conventional structure of a steering device. 1a, 1b...front wheel, 2a, 2b...rear wheel, 8...pitman arm, 9...body frame, 9B...frame material, A...reversing link mechanism.

Claims (1)

[Scope of utility model registration request] A pair of left and right front wheels 1a, 1b and a pair of left and right rear wheels 2a, 2b are provided so as to be freely steerable, and as the pair of left and right front wheels 1a, 1b are steered, the pair of left and right rear wheels 2a and 2b are provided.
In order to steer the left and right front wheels 1a, 2b in a direction opposite to the steering direction of the left and right pair of front wheels 1a, 1b, the left and right front wheels 1a, 1b and the left and right rear wheels 2a, 2b are connected by a reversing link mechanism A. A steering gear box 6 is connected between a pair of left and right frame members 9B, 9B constituting the body frame 9.
The steering gear box 6 is arranged so as to extend laterally outwardly than the frame member 9B.
A pitman arm 8 is provided to be movable back and forth, and the reversing link mechanism A is mounted on the frame member located on the same side of the aircraft as the pitman arm 8 that steers the pair of left and right front wheels 1a, 1b. 9A, and the reversing link mechanism A is disposed within the vertical width of the body frame 9 when viewed from the side.