JPH0361112A - Ground work vehicle - Google Patents

Abstract

PURPOSE:To enable pitching operation with a simple control by installing a movable frame which is oscillated up and down, on a mechanical traveling body by a pitching drive means in a ground work vehicle equipped with a rolling drive means moving a truck frame up and down in parallel. CONSTITUTION:Movable frames 11 on the left and right are pivotally mounted with a fulcrum shaft 10 in a manner to freely oscillate on a bracket 9 installed between the front part of main frames 8 on the left and right of a mechanical traveling body 7 equipped with a pair of crawler travel devices 6L, 6R on the left and right, and a hydraulic cylinder for pitching CY2 is installed between a rod 12 installed between the rear part of the movable frames 11 on the left and right and a cross frame 14 connecting the main frames 8 on the left and right. Furthermore, a pair of bell cranks 16A, 16B in the fore and aft consisting of an oscillating link 16a and a drive arm 16b are pivotally supported on the movable frames 11. Oscillating arms 16a in the front and back are connected with a connecting rod 19, and a hydraulic cylinder for rolling CY3 supported on the movable frame 11 side is connected to an oscillating arm 16a.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a vehicle body that is supported by a pair of left and right crawler traveling devices, and each of the left and right crawler traveling devices has a vertically swinging motion around the left and right horizontal axes. It is equipped with a possible pair of front and rear bell cranks, a track frame that connects the lower ends of these bell cranks, and a rolling drive means that swings these bell cranks integrally and moves the track frame up and down in parallel. Regarding ground work vehicles.

[Conventional technology]

In such a ground work vehicle, each of the crawler traveling devices is connected with a hydraulic cylinder as a rolling drive means extending between the upper end of the rear bell crank and the vehicle body, and the upper end of the pair of front and rear bell cranks is connected to each other. When the rolling hydraulic cylinders are expanded and contracted separately on the left and right sides, the vehicle body tilts in the left-right direction with respect to the ground-contacting part of the crawler traveling device. In order to perform a rolling operation, when the pitching hydraulic cylinders are operated simultaneously on the left and right sides, the vehicle body tilts forward and backward with respect to the ground contact part of the crawler traveling device, and the pitching operation is performed (actual). Publication No. 63-202582).

[Problem to be solved by the invention]

However, in such a ground work vehicle, when performing a pitching operation, two pitching hydraulic cylinders must be simultaneously expanded and contracted, which has the disadvantage of consuming a large amount of energy. Furthermore, when one of the hydraulic cylinders for rolling and pitching is telescopically operated, the expansion and contraction state of the other hydraulic cylinder must be taken into account. Since it is connected to a bell crank, it has the disadvantage that control over pitching operations is complicated.

The present invention has been made in view of this situation, and an object of the present invention is to provide a ground work vehicle that consumes less energy during pitching operation and can perform pitching operation with simple control.

[Means to solve the problem]

In order to achieve the above object, in the ground work vehicle of the present invention, the support shaft of one bell crank is supported by a fixed member fixed to the vehicle body frame, and the support shaft of the other bell crank is supported by a fixed member fixed to the vehicle body frame.
It is supported by a movable member that is movable up and down with respect to the vehicle body frame, and the support shaft on the movable member side is moved up and down relative to the vehicle body frame, so that the vehicle body is connected to the support shaft on the fixed part side. The characteristic configuration is that a single pitching drive means for tilting back and forth around the axis is provided.

[For production]

When one pitching drive means is driven, the support shaft on the movable member side moves downward relative to the vehicle body frame together with the movable member. As a result, the vehicle body tilts back and forth around the axis of the support shaft on the fixed part side, and a pitching operation is performed.

〔Effect of the invention〕

Since only one pitching driving means is required, energy consumption during pitching operation can be minimized. Furthermore, when one of the hydraulic cylinders for rolling and pitching is telescopically operated, there is no need to consider the telescoping state of the other hydraulic cylinder, which simplifies control.

〔Example〕

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

Figure 1 shows a combine harvester, which is an example of a ground work vehicle. This combine harvester includes a raising device (1) that causes the planted grain culm, a clipper-type cutting device (2) that reaps the raised grain culm, and a conveyor to transport the cut grain culm toward the rear threshing device (3). The reaping pre-processing device (5), which has a vertical conveyance device (4), etc., is connected to a pair of left and right crawler traveling devices (6L).
The hydraulic cylinder (CY
1) so that it can be freely swung up and down around the lateral fulcrum (X).

Next, move the traveling body (7) to the left and right crawler traveling devices (6L).
), (6R) A structure for pitching control that tilts in the front-rear direction with respect to the ground contact area will be described.

As shown in Figures 1 and 2, the left and right main frames (8
) A bracket (9) having an inverted U-shape in front view is installed across the front parts of the brackets (9), and a fulcrum shaft (10) is installed across the left and right lower portions of this bracket (9). At both ends of this fulcrum shaft (10) are left and right movable frames (11).
The front part is pivoted so that it can swing up and down. In addition, as shown in FIG. 3, a rod (12) is installed across the rear portions of the left and right movable frames (11), and this rod (
A pair of left and right guide frames (13) are placed on top of the guide frames (12).
) are provided to sandwich the left and right main frames (8), respectively, and when the movable frame (11) swings, the guide frame (13) comes into contact with the main frame (8). This makes it possible to restrict lateral displacement of the movable frame (11). Furthermore, the left and right main frames (8
) and the rod (1
2) One pitching hydraulic cylinder (C
Y2) (corresponding to the pitching drive means) is installed, and by extension of this pitching hydraulic cylinder (CY2), the left and right movable frames (11) simultaneously swing downward, and the traveling body (7) moves forward. so that it is in a leaning position, and
Due to the contraction, they swing upward at the same time, so that the traveling body (7) is tilted backwards. In addition, the left and right main frames (
8) Reinforcement plates (15A) are installed before and after.

(15B), especially the later reinforcement plate (15B).
B) has the function of guiding the vertical movement of the guide frame (13) while regulating its longitudinal movement.

(15B) is equipped with a limit switch (LSWI) and (LSW2) to detect whether the guide frame (13) and the pitching hydraulic cylinder (CY2) have reached the movable stroke end. It is possible to do so. Here, the limit switch that detects the state in which the traveling body (7) reaches the most forward tilted position is the forward tilt limit switch (LSWI), and the limit switch that detects the state in which the traveling body (7) reaches the most backward tilted position is the backward tilt limit switch (LSWI). LSW2) Toshishita.

Next, with respect to the traveling body (7), that is, the movable frame (
11), the left and right crawler traveling devices (6L), (
6R) will be described below. However, the left and right crawler traveling devices (6L),
Since the elevating structure of (6R) is the same, the left side will be explained below as a representative.

At each of the front and rear parts of the movable frame (11),
A pair of front and rear bell cranks (16A) and (16B) consisting of a swinging link (16a) projecting upward and a drive arm (16b) projecting downward are pivotally supported so as to be integrally swingable. A track frame (18) is pivotally attached to the lower ends of the front and rear swing links (16a), and a connecting rod (19) is installed across the tops of the front and rear drive arms (16b). It is.

Further, a rolling hydraulic cylinder (CY3) (corresponding to rolling drive means) supported on the movable frame (11) side is connected to the upper end of the rear drive arm (16a). Hydraulic cylinder (CY
The rear drive arm (16b) is designed to swing by the telescopic operation of 3).

In addition, the front bell crank (16A) is attached to the fulcrum shaft (16A).
0) is shared with the movable frame (11).

The truck frame (18) has a plurality of ground wheels (2
0) and the tension ring (21) are pivotally supported. Further, a swingable arm (22) is provided in a state that is elastically biased downward, and a grounding wheel (20) is also provided at the tip of this arm (22).
is supported by a shaft. Furthermore, a drive wheel (23) is provided on the fuselage side. And these ground contact wheels (20) and tension wheels (
21), and the drive wheel (23).
) is on a rack.

As mentioned above, the rolling hydraulic cylinder (CY
3) is extended, the front and rear bell cranks (16A)
, (16B) swing in one direction, and accordingly, the track frame (18) descends and moves toward the crawler traveling device (6).
When the hydraulic cylinder (CY3) is contracted so that the ground contact parts of L) and (6R) are lowered relative to the traveling aircraft (7), the front and rear bell cranks (16A), (
16B) integrally swing in the opposite direction, the track frame (18) rises and the crawler traveling device (
The ground contact areas of 6L) and 6R are raised relative to the traveling body (7). In short, the traveling body (7) tilts in the left-right direction due to the difference in the amount of expansion and contraction of the left and right rolling hydraulic cylinders (CY3').

Limit switches (LSW3) and (LSW4) are provided before and after the rear drive arm (17) to determine whether the drive arm (17) and the rolling hydraulic cylinder (CY3) have reached the end of their movable stroke. It should be possible to detect it. Here, the upper limit switch (LSW3) is used to detect the state in which the crawler traveling devices (6L) and (6R) are at the farthest position from the traveling body (7), and the upper limit switch (LSW3) is used to detect the state in which the crawler traveling devices (6L) and (6R) are at the closest position to the traveling body (7). The limit switch to be detected is the lower limit switch (LSW4). In addition, the right crawler traveling device (6R) is also equipped with limit switches (1, 5W3) and (LSW4), so to avoid confusion, we have added L and R to mean left and right sides. put.

The operating section of the traveling machine (7) includes a cutting height setting device (25) for setting the cutting height of the cutting pre-treatment device (5), as shown in FIG. 4, in order to perform various controls. ), traveling aircraft (
Setting devices such as a longitudinal inclination angle setter (26) for setting the target longitudinal inclination angle with respect to the horizontal reference plane (7), a left-right inclination angle setting device (27) for setting the target left-right inclination angle,
Switches such as the automatic/manual mode changeover switch (SWI) that switches between manual mode and automatic mode, the upper and lower limit mode changeover switch (SW2) that changes between upper limit reference mode and lower limit reference mode, and the posture of the manual mode. cross lever (28), traveling aircraft (7)
) The aircraft lift lever (29) is used to raise and lower the entire
), etc., and as shown in FIG. 5, this information is output to a control device (100) unitized as a microcomputer (100).

Let me add some additional information about the upper limit reference mode and lower limit reference mode. For rolling control, left and right crawler running devices (6L
), (6R) A descending reference elevation control state (hereinafter referred to as lower limit reference mode) that brings each ground contact part closer to the traveling aircraft side, and the left and right crawler traveling devices (6L)
(6R) There is an ascent reference elevation control state (hereinafter referred to as upper limit reference mode) in which each ground contact portion is separated from the traveling aircraft (7). In lower reference mode,
When the left and right inclination angle of the traveling body (7) is within the dead zone with respect to the target inclination angle, the left and right crawler traveling devices (6L),
The rolling hydraulic cylinder (CY3) is telescopically operated to bring the ground contact part of the traveling aircraft (6R) closer to the traveling aircraft side, and in the upper limit reference mode, the horizontal inclination angle of the traveling aircraft (7) is set to the target inclination angle (3 If it is within the dead zone, the rolling hydraulic cylinder (
CY3) will be expanded and retracted. In other words, in the lower limit standard mode, rolling control is performed while keeping the height of the traveling aircraft (7) above the ground as low as possible, and in the upper limit reference mode, the height of the traveling aircraft (7) above the ground is made as high as possible. However, rolling control will be performed. Note that detailed control operations in each of the lower limit reference mode and upper limit reference mode will be described later.

The cross lever (28) has four operation switches (28
a) to (28d), and when operated from the neutrally biased center position forward, backward, left, or right, any of the operation switches (28a) to (28d) sends a signal for attitude control to the control device (100). is now emitted. In other words,
If the cross lever (28) is operated forward, a signal instructing a pitching operation will be issued from the forward tilt operation switch (28a), and the traveling aircraft (7) will be in a forward tilt instruction state to be tilted forward, and if operated later, A signal instructing a pitching operation is emitted from the backward tilting operation switch (28b), resulting in a backward tilting instruction state, and when the left tilting operation switch 3 (28c) is operated, a signal instructing a rolling operation is issued from the left tilting operation switch (28c). The left tilt instruction state is entered, and when the right tilt operation switch (28d) is operated, a signal instructing a rolling operation is issued, and the right tilt instruction state is entered.

The aircraft lift lever (29) has two operation switches (
29a) and (29b), and when operated forward from the neutral biased center position, the lift operation switch (2
9a) sends a signal to the control device (100) instructing the traveling body (7) to rise, and when the traveling body (7) rises relative to the crawler traveling devices (6L) and (6R) and operates backward. , a signal instructing the lowering operation switch (29b) to lower the traveling body (7) is issued to the control device (100), and the traveling body (7) moves to the crawler traveling device (6L),
(6R).

The reaping lifting hydraulic cylinder (CYI), the pitching hydraulic cylinder (CY2), and the rolling hydraulic cylinder (CY3) each include a three-position switching type electromagnetic valve (m), (V2). .

4 (v3) are connected, and these three-position switching type electromagnetic valves m), (V2), and (V3) are connected to the control device (
100). And this control device (10
Various hydraulic cylinders (CYI
), (CY2).

(CY3) is designed to expand and contract. In addition, from each pump (P) to each electromagnetic valve m).

A schematic hydraulic circuit for supplying pressure oil to (V2) and (V3) is shown in FIG. In the figure, (VO) is a switching valve for controlling the supply to the electromagnetic valves m), (V2), and (V3), (RV) is a relief valve, and (E
) is the engine.

As shown in FIG. 5, the control device (100) also includes the forward tilt limit switch (LSWI),
Backward tilt limit switch (LSW2), upper and lower limit switch (LSW3L), (LSW3R), (L
SW4L).

(LSW4R) and other switches, reaping pre-treatment device (5)
A cutting height sensor (Sl) for detecting the cutting height, a weight-type longitudinal inclination angle sensor (S2) for detecting the longitudinal inclination angle of the traveling body (7) with respect to the horizontal reference plane (S2), and a left-right inclination Sensors such as a weight type left and right tilt sensor (S3) for detecting angles are connected.

The control device (100) controls a three-position switching type electromagnetic valve m) based on the information inputted from these devices.
(V2). In other words, the control device (100) controls the electromagnetic valve (■1) so that the cutting pretreatment device (5) reaches the cutting height set by the cutting height setting device (25) based on the information from the cutting height sensor (Sl). The mowing height is controlled based on the information from the longitudinal inclination angle sensor (S2).
) performs pitching control to control the electromagnetic valve (V2) so that the longitudinal inclination angle is set by the longitudinal inclination angle setting device (25), and the left and right inclination angle setting device (25) performs pitching control based on the left and right inclination sensor (S3). Solenoid valve (
(3) Rolling control is performed to control 3).

Next, pitching control and rolling control performed by the control device (100) will be explained based on flowchart 1 of FIGS. 7 to 10. In addition, the control device (100) is
In reality, cutting height control is also performed at the same time, but the description of the invention will be omitted below for the sake of clarity. Note that the step numbers in the diagram are indicated with a # mark.

What is shown in FIG. 7 is the main flow of rolling control. First, after starting, initialize the timer and various flags. After the set time has elapsed, output control is performed to write the contents of various flags to the output port, and the output flags are cleared. Next, the target inclination angle (target angle) is calculated by reading the output values from various sensors and setting devices. After completing the calculation, execute the output evaluation process,
Return to step 20 (steps IO to 70).

What is shown in FIG. 8 is a subroutine for target angle calculation processing executed in step 60. A correction value is obtained from the output value of a fine adjustment volume (not shown), and this correction value is used to set the left and right tilt setting device (26) and the front and rear tilt setting device (27).
) to set the left and right target angles and the front and rear target angles. Note that the fine adjustment volume is already a setting device at the time of shipment.

7. What is shown in FIGS. 9(a) and 9(c) is the subroutine of the output evaluation process executed in step 70. However, in the following description, lower left, upper left, lower right, upper right, upper, and lower rear each mean the vertical operation direction of the left and right sides or the front and rear of the traveling body (7).

First, neither the cross lever (28) nor the machine lift lever (29) is operated, the automatic mode is selected with the automatic/manual mode changeover switch (SWI), and the threshing switch (SW3') is turned on. If the upper limit reference mode is selected with the upper/lower limit mode changeover switch (SW2), the upper limit reference mode is set, and if the lower limit reference mode is selected, the lower limit reference mode is set (steps 101 to 106).

However, if the cross lever (28) or the aircraft elevation lever (29) is operated in step 101, the mode is temporarily switched to manual mode (step 108). Also, step 1
Either the manual mode is selected with the automatic/manual mode changeover switch (SWI) in step 02, or the threshing switch (SW3) is turned off in step 103.
If so, set the lower limit reference mode, switch to manual mode, and proceed to step 141 (step 102).
．． 103.107.108).

Illustrated in FIG. 1O is the manual mode subroutine executed at step 108. Cross lever (28)
is operated forward and forward tilt operation switch Sochi (28a) is turned on.
If so, set the pull-out solenoid output flag and turn OF
If F, the process continues as is (steps 200 and 201).

If the cross lever (28) is operated later and the backward tilt operation switch (28b) is turned on, the drop solenoid output horn flag is set, and if it is turned off, the process continues (steps 202 and 203). If the cross lever (28) is operated to the left and the left tilt operation switch (28c) is turned ON, the lower left solenoid output flag and the upper right solenoid output flag are set, and if they are OFF, the process continues (step 204.
205), if the cross lever (28) is operated to the right and the right tilt operation switch (28d) is turned ON, the upper left solenoid output flag and the lower right solenoid output 9 flag are set, and if it is OFF, the process continues (step 206). .207). If the body lifting lever (29) is operated later and the lowering operation switch (29b) is turned ON, the lower left solenoid output flag and the lower right solenoid output flag are set, and if they are OFF, the process continues (steps 208 and 209). If the aircraft lift lever (29) is operated forward and the lift operation switch (29a) is turned ON, the upper left solenoid output flag and the upper right solenoid output flag are set, and if they are OFF, proceed to step 241 (steps 210 and 211). ).

In the automatic mode, when the lower limit reference mode or the upper limit reference mode is set, first, the left and right declination angle is calculated by subtracting the tilt angle detected by the left and right tilt angle sensor (S3) from the left and right target angle set in step 60. (Step 109).

In the lower limit reference mode, when the polarity of the left and right declination angles is positive and upward to the left, and the left and right declination angles are outside the dead band,
Furthermore, if the left and right deviation angle is significantly large and the left lower limit switch (LSW4L) 0 is OFF, the lower left solenoid output flag is set and the process proceeds to step 141 (steps 110 to 115).
. However, in step 113, it is determined that the left and right deviation angle is small, and the left lower limit switch (LSW4L)
is determined to be ON, or in step 114
If it is determined that the left lower limit switch (LSW4L) is ON, the upper right solenoid output J flag is set and the left lower limit switch (LSW4L) is turned on.
If it is determined that W4L) is OFF, the process directly proceeds to step 141 (steps 116 and 117).

In the lower limit reference mode, the polarity of the left and right declination angles is positive and upward to the left, but the left and right declination angles are within the dead zone, and the left and right lower limit switches (LSW4L).

If both (LSW4R) are OFF, set the lower right solenoid output flag and the lower left solenoid output flag and proceed to step 141, and either the left or right lower limit switch (LSW4L) or (LSW4R) is OFF.
If N, the process directly proceeds to step 141 (steps 110 to 112, 118, and 119).

1 In the lower limit reference mode, when the polarity of the left and right yaw angle is negative and is rising to the right, and the left and right yaw angle is outside the dead band, this left and right yaw angle is extremely large, and the right lower limit switch (LSW4R ) is OFF, the lower right solenoid output flag is set and the process proceeds to step 141 (steps 110, 111, 120 to 123). However, in step 121, it is determined that the left and right deviation angle is small, and the right lower limit switch (LSW4R) is set to O.
If it is determined that the FF is FF, or if it is determined that the right lower limit switch (LSW4R) is ON in step 122, the upper left solenoid output flag is set and the process proceeds to step 141. If it is determined that the lower limit switch (LSW4R) is ON, the process directly proceeds to step 141 (step 124.1).
25).

In the lower limit reference mode, the polarity of the left and right declination angles is negative and upward to the right, but the left and right declination angles are within the dead zone, and the left and right lower limit switches (LSW4L).

If both (LSW4R) are OFF, set the lower right solenoid output flag and the lower left solenoid output flag and proceed to step 141, and also set one of the left or right lower limit switches (LSW4L) and (LSW4R). If is ON, the process directly advances to step 141 (steps 110.111.120.118.119).

In the upper limit reference mode, when the left and right declination angles are in a positive polarity and rising to the left, and the left and right declination angles are outside the dead band,
Furthermore, if this left/right deviation angle is extremely large and the right upper limit switch (LSW3R) is ON, the lower left solenoid output flag is set and the process proceeds to step 141 (
Steps 110.126-140). However, step 1
In step 28, it is determined that the left and right deviation angle is small, and in addition, it is determined that the right upper limit switch (LSW3R) is OFF, or in step 129, the right upper limit switch (LSW3R) is OFF. If it is determined that
If it is determined that W3R) is ON, the process directly proceeds to step 141 (step 13), 132).

In the upper limit reference mode, when the polarity of the left and right declination angle is positive and rising to the left, but the left and right declination angle is within the dead zone, the left and right upper limit switches (LSW3L),
(LSW3R) are both OFF, set the upper right solenoid output flag and the upper left solenoid output flag and proceed to step 141, and either the left or right upper limit switch (LSW3L) or (LSW3R) is ON. If so, the process directly proceeds to step 141 (steps 110, 126° 127, 133, 134).

In the upper limit reference mode, when the polarity of the left and right yaw angle is negative and upward to the right, and the left and right yaw angle is outside the dead band,
Furthermore, the left and right deviation angle is extremely large, and what's more, the left upper limit switch (LSW3L).

If (LSW3R) is ON, set the lower right solenoid output flag and proceed to step 141 (step 11
0.126.135-138). However, step 136
If it is determined in step 139 that the left/right deviation angle is small and that the left upper limit switch (LSW3L) is OFF, or if it is determined in step 139 that the left upper limit switch (LSW3L) is OFF. If it is determined that the left upper limit switch (LSW3L) is ON, the upper left solenoid output flag is set and the process proceeds to step 141. If it is determined that the left upper limit switch (LSW3L) is ON, the process directly proceeds to step 141 (step 139. 140)
.

In the upper limit reference mode, when the polarity of the left and right declination angle is negative and rising to the right, but the left and right declination angle is within the dead zone, the left and right upper limit switches (LSW3L),
If both (LSW3R) are OFF, set the upper right solenoid output flag and the upper left solenoid output flag and proceed to step 141, and if either the left or right upper limit switch (LSW3L) or (LSW3R) is ON. If there is, the process directly proceeds to step 141 (steps 110, 126° 135, 133, 134).

Next, as shown in FIG. 9(b), the total longitudinal declination angle is calculated by subtracting the inclination angle detected by the longitudinal inclination angle sensor (S2) from the left and right target angle set in step 6o (step 141). ). The polarity of the longitudinal yaw angle is positive, the longitudinal yaw angle is outside the dead zone, and the forward tilt limit switch (LSWI) is OFF.
In this case, the extraction solenoid output flag is set and the process proceeds to step 149 (steps 142 to 145). However, if it is outside the dead zone in step 143 or if it is outside the dead zone in step 144.
If it is determined that the forward tilt limit switch (LSWI) is ON, the process directly advances to step 149.

The polarity of the longitudinal yaw angle is negative, the longitudinal yaw angle is outside the dead zone, and the backward tilt limit switch (
If LSW2) is OFF, set the rear lower solenoid output flag and proceed to step 149 (step 14
2.146-148). However, if it is outside the dead zone in step 146 or if the backward tilt limit switch (
If it is determined that LSW2) is ON, the process directly advances to step 149.

Next, as shown in Figure 9 (c), if the left lower limit switch (LSW4L) is ON, the lower left solenoid output flag is cleared and the next step is performed, and if it is OFF6, the lower left solenoid output flag is left as is and the next step is performed. (Steps 149 and 150). If the lower right limit switch (LSW4R) is ON, the lower right solenoid output flag is cleared and the process proceeds to the next step; if it is OFF, the lower right solenoid output flag is left as is and the process proceeds to the next step (steps 151 and 152). Left upper limit switch (LSW)
3L) is ON, clear the upper left solenoid output flag and proceed to the next step; if OFF, leave the upper left solenoid output flag as is and proceed to the next step (step 153.15).
4).

If the right upper limit switch (LSW3R) is ON, clear the upper right solenoid output flag and proceed to the next step.
If F, the upper right solenoid output flag is left as is and the process proceeds to the next step (steps 155 and 156). If the forward tilt limit switch (LSWl) is ON, the lifting solenoid output flag is cleared and the process proceeds to the next step, and if it is OFF, the lifting solenoid output flag is left as is and the process proceeds to the next step (steps 157 and 158). Backward tilt limit switch (LSW2)
If it is ON, the rear lower solenoid output flag is cleared and the flow returns to the main fin flow (steps 159 and 160).

[Another example]

Furthermore, the present invention can also be applied to ground work vehicles other than combines, such as a straw harvester.

Note that although reference numerals are written in the claims section for convenience of reference to the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of drawings]

The drawings show an embodiment of the ground work vehicle according to the present invention, and FIG. 1 is a side view of a crawler traveling device, FIG. 2 is a plan view of the side view of the crawler traveling device, and FIG. 3 is a diagram showing the installation of a pitching hydraulic cylinder. Figure 4 is a plan view of the operating section, Figure 5 is a diagram showing the structure.
Figure 6 shows the overall configuration of the control system, Figure 6 shows the hydraulic circuit diagram, Figure 7 shows the main flow, Figure 8 shows the target angle calculation subroutine, and Figures 9 (a), (0), and (c) are FIG. 10 is a subroutine for output evaluation processing, and FIG. 11 is a side view of the entire combine harvester. (7)・・・Car body, (6L), (6R)・
... Crawler traveling device, (8) ... Vehicle body frame, (16A), (16B) ... Bell crank, (11) ... Movable frame, ( ■8
)...Track frame, (CY2)...
...Pitching drive means, (CY3)...Rolling drive means.

Claims (1)

[Claims] The vehicle body (7) has a pair of left and right crawler traveling devices (6L).
), (6R), and each of the left and right crawler traveling devices (6L), (6R) has a pair of front and rear bell cranks (16A), (1
6B) and these bell cranks (16A), (16B)
a track frame (18) that connects the lower ends of the
This ground work vehicle is equipped with a rolling drive means (CY3) that integrally swings and drives these bell cranks (16A) and (16B) to move the track frame (18) up and down in parallel, A movable frame (11) that can swing around the left and right horizontal axes is provided on the vehicle body frame (8), and the bell cranks (16A) and (16B) are pivotally supported at the front and rear of this movable frame (11). The ground work vehicle is also provided with one pitching drive means (CY2) for tilting the vehicle body (7) back and forth by swinging the movable frame (11) relative to the vehicle body frame (8). .