JPH0419283A - Working vehicle - Google Patents

Abstract

PURPOSE:To improve running performance by providing an orientation varying mechanism to switch orientation to a rearwardly downward state and setting the position of the center of gravity of a machine body to a spot above the central position in a longitudinal direction of the earthing surface of a crawler running device or to spot located rearwardly thereof. CONSTITUTION:An orientation varying mechanism 17 to switch an erthing surface 21a of crawler running devices 4R and 4L to rearwardly downward orientation based on a base body is provided. The position of the center of gravity of a machine body is set to a spot above the central position in the longitudinal direction of the earthing surface 21a of the crawler running devices 4R and 4L or to a spot located rearwardly of the central position. This constitution effects switching operation so that the earthing surface 21a of the crawler running devices is brought into rearwardly downward orientation based on a machine body. This operation suppresses the change of rearwardly downward orientation. Inversely, during reversing, the earthing surface 12a of the crawler running devices is restored to an original posture in parallel to the machine body. In this case, even when a propulsion reaction force is exerted, the front part of the machine body is prevented from lowering.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a working vehicle equipped with a pair of crawler traveling devices on both left and right sides of the vehicle.

[Conventional technology]

An agricultural combine harvester is one of the above-mentioned work vehicles. In recent years, combine harvesters are often equipped with various waste straw processing devices, including a waste straw binding device, at the rear of the machine, and the rear of the machine tends to be heavier. For this reason, in wet rice fields, the rear side sinks and tends to fall backwards. If the aircraft moves forward in this state, the front side of the aircraft may rise due to the propulsion reaction force of the crawler traveling device, and may even tend to move backward.

In this way, if the machine descends backwards, it will have a negative effect on the sorting inside the threshing device, so in order to suppress this downward tendency, each part is set so that the center of gravity of the entire machine is as close to the front as possible. It is being said.

[Problems to be Solved by the Invention] When a combine harvester completes one reaping stroke and reaches the edge of a ridge, it repeats forward and backward movement to change the orientation of the machine and enter the next reaping stroke. Therefore, if the center of gravity is located on the front side of the aircraft body as described above, the front side of the aircraft body will easily move down if the propulsion reaction force of the crawler traveling device is applied during backward movement.

This may cause the cutting section at the front of the machine to collide with the ground and be damaged.

Here, an object of the present invention is to suppress the backward downward tendency during forward movement, and also to suppress the forward downward downward tendency during reverse movement.

[Means to solve the problem]

The feature of the present invention is that the above-mentioned work vehicle is configured as follows. In other words, it is equipped with an attitude change mechanism that switches the ground contact surface of the crawler traveling device to a rearward downward attitude with respect to the aircraft body, and the center of gravity of the aircraft is located on the front-rear center position of the ground contact surface of the crawler travel device, or behind this front-rear center position. The functions and effects are as follows.

[For production]

With the configuration as described above, when moving forward, it is only necessary to perform a switching operation so that the ground contact surface of the crawler traveling device is in a backward downward attitude with respect to the aircraft body. As a result, even if the aircraft attempts to descend backwards during forward movement, the downward descending ground contact surface prevents the aircraft from returning to its forward descending attitude, thereby suppressing the backward descending attitude change.

Conversely, when going backwards, the ground plane of the crawler traveling device may be returned to its original position parallel to the aircraft body.

In this case, the center of gravity of the aircraft is on the front and back center of the ground plane, or
Since it is located at the rear of this position, the front part of the aircraft is prevented from lowering even if the propulsion reaction force from the crawler traveling device is applied during backward movement.

[Effects of the invention] As described above, it is now possible to suppress backward descent when moving forward and forward descent when reversing, and the negative effects (
This makes it possible to prevent problems such as deterioration in sorting performance within the threshing equipment, thereby improving the running performance of work vehicles.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

As shown in Figure 4, there is a reaping section (1) and a traveling transmission (2) at the front of the machine, and a threshing device (3) at the rear of the machine.
A combine harvester, which is an example of a working vehicle, is constructed by mounting this machine body and supporting it with a pair of left and right crawler traveling devices (4R) and (4L).

Next, the crawler traveling devices (4R) and (4L) will be explained. As shown in Figures 1 and 2, support frames (22
) is extended, and the crawler frame (
5) is installed. Also, the support frame (22)
A fixed fuselage frame (27) extends toward the rear of the fuselage, and a first hydraulic cylinder (17) extends between the fuselage frame (27) and the crawler frame (5).
(equivalent to an attitude change mechanism) is installed.

A pair of support shafts (7) and (8) are rotatably supported at the front and rear of the crawler frame (5), and supported at the outer ends of both support shafts (7) and (8) so as to face the aircraft rearward. Arms (9) and (10) are fixed. On the other hand, a plurality of rolling wheels (11) and guide wheels (12) are supported by the truck frame (13), and the rain rear ends of the front and rear support arms (9) and (10) are supported by the truck frame (13). is pivotally connected to. Drive wheels (6) are provided at both ends of the support frame (22), and a crawler (21) is wound around the drive wheels (6), roller wheels (11), and guide wheels (12). .

Operating arms (15) and (16) are fixed to the inner ends of both support shafts (7) and (8), respectively, and the front operating arm (15) and crawler frame (5)
The support part (5a) of the second hydraulic cylinder (18
) has been constructed. Furthermore, the front and rear operation arms (15
), (16), and an interlocking link (20) is installed.

With the above structure, by telescopically driving the second hydraulic cylinder (18), the track frame (13) is moved up and down in parallel to the crawler frame (5), and the crawler traveling device (4R), (4L) Ground plane (21a)
It moves up and down. And the first hydraulic cylinder (
17) by telescopically driving the crawler frame (
5) up and down around the horizontal axis (Pl), the ground planes (21a) of the crawler traveling devices (4R) and (4L) can be placed in a forward-down position relative to the aircraft frame (27), or in a backward-down position. It's a posture.

In addition, as shown in Fig. 4, a crawler traveling device (4R)
, (4L), the center of gravity (G) of the aircraft is located behind the front-rear center position (X) of the ground contact surface (21a).

As shown in Figure 3, it is equipped with a tilt sensor (14) that detects the horizontal tilt of the aircraft relative to the ground.
The detected value is input to the control device (19). or,
A switching lever (23) is provided for the forward/reverse switching device (not shown) in the mission (2) in Fig. 2, and detects that the switching lever (23) is operated to the forward position (F). A limit switch (24a) and a limit switch (24b) that detects operation to the reverse position (R)
is provided.

This causes the switching lever (23) to move to the forward position 1f (F).
, the first hydraulic cylinder (17)
The first hydraulic cylinders (17 ) is expanded. Then, the control device (1) is connected to the second control valves (26R) (26L) for the left and right second hydraulic cylinders (18) so that the aircraft is horizontal on the left and right based on the detected value of the tilt sensor (14).
An operation signal is issued from 9), and the track frame (13) of the left and right crawler traveling devices (4R) and (4L)
are each driven up and down independently.

Conversely, when the switching lever (23) is operated to the reverse position (R), the first control valves (25R) and (25L) cause the left and right crawler frames (5) to become parallel to the fuselage frame (27). The first hydraulic cylinder (17) is operated to contract. And the second control valve (26R), (26L
), the left and right second hydraulic cylinders (18) are contracted to their stroke ends, and the truck frame (
13) is configured to be operated downward.

During the aforementioned backward movement, the left and right crawler frames (5)
The truck frame (13) may be lowered while in the forward downward position.

In the above-mentioned embodiment, the crawler frame (5) is oscillated to set the ground plane (21a) of the crawler (21) in a backward descending position. The ground contact surface (21a) of the crawler (21) may be in a backward downward position.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of the drawing]

The drawings show an embodiment of the work vehicle according to the present invention, FIG. 1 is a side view showing the elevating structure of the crawler traveling device, FIG. 2 is a plan view showing the elevating structure of the crawler traveling device, and FIG. 3 is a control circuit. FIG. 4 is an overall side view of the combine harvester. (4R), (4L)... Crawler traveling device, (17)... Attitude change mechanism, (21a)...
... Ground contact surface of crawler traveling device, (X) ...
・Front-rear center position of the ground plane, (G)・・・Center of gravity of the aircraft.

Claims (1)

[Scope of Claims] A work vehicle equipped with a pair of crawler traveling devices (4R) and (4L) on both left and right sides of the machine body, wherein the ground contact surface (21) of the crawler traveling devices (4R) and (4L)
a) is equipped with an attitude change mechanism (17) for switching the a) to a backward descending attitude with respect to the aircraft, and a crawler traveling device (4R),
(4L) front and rear center position (X
), or the center of gravity (G) of the machine is set behind this front-rear center position (X).