JPH0424177A - Working vehicle - Google Patents

Abstract

PURPOSE:To prevent rear downward movement at the time of advance and front downward movement at the time of advance by installing a lifting function which moves the track frame of a crawler traveling device vertically in parallel and a posture changing mechanism which changes the front and rear posture of a vehicle body frame to rear upward posture and rear downward posture. CONSTITUTION:In crawler traveling devices 4R, 4L, a crawler frame 5 is installed around the horizontal axial center PI of a supporting frame so as to oscillate vertically freely, and the first hydraulic cylinder 17 (posture changing mechanism) is mounted over a vehicle body frame 27 and the crawler frame 5. Also, operating arches 15, 16 are fixed respectively on the inner ends of a pair of supporting shafts 7, 8 rotatably-supported on the front and rear of the crawler frame 5, and the second hydraulic cylinder 18 (lifting mechanism) is mounted over a front side operating arm 15 and the supporting part 5a of the crawler frame 5.

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.

[Problem 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 begin 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 movement during reverse movement without any problem.

[Means to solve the problem]

The feature of the present invention is that the above-mentioned work vehicle is constructed as follows. That is, a lifting mechanism that moves up and down a track frame that supports the rolling wheels and a guide wheel at the rear end of the crawler traveling device in parallel or substantially parallel to the body frame located above the crawler traveling device; an attitude change mechanism that changes the longitudinal attitude of the fuselage frame around a front fulcrum between a rear ascending attitude and a rear descending attitude; and a detection means that detects that the track frame is being lowered relative to the aircraft frame. , and a restraining means that allows the attitude change operation of the aircraft frame to the rear downward direction only when the track frame is being operated downward relative to the aircraft frame, and its functions and effects are as follows. It is.

[For production]

With the configuration as described above, when moving forward, the attitude change mechanism can be used to switch the body frame to the backward upward attitude with respect to the track frame of the crawler traveling device. As a result, even if the aircraft falls backwards when moving forward, this is corrected and the aircraft remains approximately horizontal.

On the other hand, when going backwards, for example, as shown in Figure 3, the elevating mechanism (
18), the fuselage frame (27) must be lowered.

(28) cannot be switched to the backward descending position. In other words, when the track frame (13) is lowered, the wheels (11)
At the same time, the guide wheel (12) at the rear end will also descend,
The upper surface of the crawler (21) has a backward downward shape.

Therefore, the rear of the crawler (21) and the fuselage frame (27)
) and (28), so the aircraft frame (27)
, Even if (28) is in the backward-down position, the aircraft frame (
27) and (28) never come into contact with the top surface of the crawler (21).

As described above, by placing the aircraft frame in a backward descending position when moving backward, it is possible to suppress forward descending of the aircraft. In addition, when the machine frame is placed in a rearward downward position, the truck frame is lowered and the machine is lifted up, so when going backwards to cross a large step such as a ridge, the working equipment at the front of the machine (reaping section, etc.) may be on the ground. There's no such thing as a collision.

〔Effect of the invention〕

As described above, it is now possible to suppress backward descending when moving forward and forward descending when reversing without having to specifically move the center of gravity of the machine to the front of the machine. etc.) can now be prevented,
We were able to improve the driving performance of the work vehicle.

Furthermore, when moving backward, the body frame is prevented from inadvertently switching to a backward downward position and causing the body frame to collide with the rear upper surface of the crawler.

In addition, in the case of work vehicles where the rear visibility from the cockpit is not sufficient when the aircraft is lifted when reversing, it is less likely that the operator will come into contact with an obstacle on the ground without noticing it, and it will also reduce the possibility of large steps. You can cross it without any problem by going backwards.

〔Example〕

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

As shown in Figure 5, 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. Support frame (2
Drive wheels (6) are provided at both ends of the drive wheel (2).
6) A crawler (21) is wound around the wheel (11) and the guide wheel (12).

Operation arms (15) and (16) are fixed to the inner ends of both support shafts (7) and (8), respectively, and the front operation arm (15) and the support part (5a) of the crawler frame (5) A second hydraulic cylinder (1B) (corresponding to an elevating mechanism) is installed over this area. Furthermore, a link (2) is provided between the front and rear operation arms (15) and (16).
0) has been constructed.

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 devices (4R) and (4L) are moved up and down in parallel to the crawler frame (5). The ground plane (21a) is moved up and down. Then, the first hydraulic cylinder (1
7) by telescopically driving the track frame (13).
) and the crawler frame (5), the fuselage frames (27) and (28) are operated to switch around the horizontal axis (Pl) into a rear-up attitude, a parallel attitude, and a rear-down attitude.

As shown in FIG. 4, an inclination sensor (14) is provided to detect the horizontal inclination of the aircraft relative to the ground, and its detected value is input to a control device (19). This results in
When moving forward, the second left and right hydraulic cylinders (
2nd control valve (26R), (26L) for 18)
An operation signal is issued from the control device (19), and the track frames (13) of the left and right crawler traveling devices (4R) and (4L) are each independently driven up and down.

In this case, operate the first operating lever (23) for the first control valves (25R) and (25L) for the left and right first hydraulic cylinders (17) to extend the first hydraulic cylinder (17) and If (27) and (28) are placed in the rear-up position, the aircraft can be made horizontal in both the front and rear directions.

When traveling backwards, the left and right track frames (13) are not raised or lowered by the tilt sensor (14), and the second control valve (2) is operated by operating the second operating lever (24).
6R), (26L) Therefore, the second hydraulic cylinder (1
8) can be expanded or contracted artificially. Then, as shown in FIG. 4, the first and second hydraulic cylinders (17) and (18
), there is a potentiometer (2) that detects each extension position.
9) and (30) (corresponding to the detection means) are attached.

Therefore, when the left and right track frames (13) are lowered using the second operation lever (24) when moving backward, the guide wheels (12) will also lower together with the road wheels (11), as shown in Figure 3. The upper surface of the crawler (21) becomes backward downward. And the second hydraulic cylinder (18) in this posture
The extended position of is detected by the potentiometer (30) and input to the control device (19).

As a result, the first hydraulic cylinder (17) is contracted by the first operating lever (23), and the fuselage frame (27),
(28) in the backward downward position, the first hydraulic cylinder (17) retracts until the fuselage frames (27) and (28) are in close proximity to the top surface of the crawler (21), and the potentiometer (29) ), the first control valves (25R) and (26L) are automatically returned to the neutral stop position, and the contraction of the first hydraulic cylinder (17) is stopped.

In the above-mentioned embodiment, a limit switch (corresponding to the detection means) is provided to detect when the second hydraulic cylinder (18) reaches the stroke end on the contraction side (when the track frame (13) reaches the lowest position). The first operating lever (23) may be configured so that it cannot be operated in the rearward downward direction unless such a state is reached.

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 truck frame. FIG. 4 is a control circuit diagram, and FIG. 5 is an overall side view of the combine harvester. (4R), (4L)... Crawler traveling device, (11)... Rolling wheels, (12)... Guide wheels, (13)... Truck frame, (17
)...Attitude change mechanism, (18)...Elevating mechanism, (27), (28)...Airframe frame, (30)...Detection means .

Claims (1)

[Claims] A work vehicle equipped with a pair of left and right crawler traveling devices (4R) and (4L), the crawler traveling devices (4R) and (4L)
The track frame (13) supporting the rolling wheels (11) and the rear end guide wheels (12) in the crawler traveling device (4R) and the fuselage frame (4L) located above the crawler traveling device (4R)
27), an elevating mechanism (18) that moves up and down in parallel or substantially parallel to (28), and the track frame (1).
an attitude changing mechanism (17) that changes the longitudinal attitude of the fuselage frames (27), (28) with respect to 3) between a rear ascending attitude and a rear descending attitude around a front fulcrum, and the track frame (13) Detection means (30) detects that the aircraft frames (27), (28) are being lowered.
), and the track frame (13) is connected to the fuselage frame (
27) A work vehicle equipped with a restraining means that allows the attitude change operation of the body frames (27) and (28) to the rear downward direction only when the body frames (27) and (28) are being operated downward.