JPH085300B2 - Rolling control device for work vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an elevating and lowering drive means for freely elevating and lowering at least a grounding portion of each of a pair of left and right traveling devices with respect to a vehicle body, and a left and right inclination of the vehicle body. Inclination angle detection means for detecting an angle, a manual elevation instruction operation tool for instructing the elevation drive means to issue an elevation command, and the elevation movement for maintaining the target inclination angle based on information from the inclination angle detection means. An elevating control means for instructing the elevating command to the driving means, a manual mode for instructing the elevating command to the elevating driving means by the elevating instruction operation tool, and an automatic mode for instructing the elevating command to the elevating driving means by the elevating control means. Selection means for selecting a mode, and the ascending / descending control means includes a descending reference ascending / descending control state for causing the grounding portions of the left and right traveling devices to approach the vehicle body side, and Regarding the right of the traveling device each work vehicle rolling control apparatus as switched operably configured grounding portion and the upper limit reference elevation control state so as to separate from the vehicle body.

[Conventional technology]

In the conventional rolling control device for a work vehicle, an automatic / manual mode changeover switch is provided as a selection means, and a manual elevating switch is provided as an elevating / instructing operation tool. An elevating command is given to the means, and the left and right traveling devices are moved up and down with respect to the vehicle body (for example, Japanese Patent Application No. 62-
See No. 170321). In the automatic mode, the upper limit reference lift control state (upper limit mode) and the lower limit reference lift control state (lower limit mode) of the lift control means are selected and pressed, and the upper limit mode button switch and the lower limit mode button switch are pressed. It is designed to be switched by operation (for example, see Japanese Patent Laid-Open No. 63-7716).

[Problems to be Solved by the Invention]

In the rolling control device for a work vehicle described above, the elevating switch is operated only in the manual mode, whereas the button switch is operated only in the automatic mode. That is, since the respective operation tools differ depending on the manual mode and the automatic mode, when either one of the modes is selected, the operation tool used in the other mode is not always used. Therefore, it is necessary to properly use the operation tool in each of the manual mode and the automatic mode, and therefore, it is easy to make a mistake or an error in operation.

Further, since separate operating tools required for the manual mode and the automatic mode are required, there is a problem that a dedicated space for installing the operating tools becomes large and a mechanical structure becomes complicated.

The present invention has been made by paying attention to such an actual situation, and an object thereof is to simplify an operation tool which is operated in a manual mode and an automatic mode and to eliminate the above-mentioned drawbacks.

[Means for solving the problem]

In order to achieve the above object, in the rolling control device for a working vehicle according to the present invention, in the first invention, in the automatic mode, the ascending / descending instruction operation device has the lower limit reference up / down control state and the upper limit reference up / down control state. It is characterized in that it is configured to instruct the elevation control means of the selection command.

A second aspect of the invention specifies a preferred mode for carrying out the first aspect of the invention. In the second aspect of the invention, the raising / lowering instruction operation tool simultaneously lowers the ground portions of the left and right traveling devices. A descending instruction state instructing an instruction to operate, an ascending instruction state instructing an instruction to raise the grounding portions of the left and right traveling devices at the same time, and a left tilt instruction state instructing an elevating instruction to incline the vehicle body to the left. , A tilting instruction state for instructing a lifting instruction for tilting the vehicle body to the right and a lifting stop state are freely switchable, and commands for the descending instruction state and the ascending instruction state of the elevator instruction operation tool are used for the elevator control. It is characterized in that it is configured so as to be a means selection command.

A third aspect of the invention specifies a preferred mode for carrying out the second aspect of the invention. In the third aspect of the invention, in the automatic mode, the elevating / lowering instruction manipulator is in a left tilt instruction state or a right tilt instruction. It is characterized in that the elevating and lowering drive means is operated based on the command when the state is switched.

[Action]

According to the first aspect of the present invention, the manual lifting / lowering instruction operating tool for instructing the lifting / lowering drive unit to command the lifting / lowering command in the manual mode causes the lifting / lowering control unit to perform the lower limit reference lifting control state and the upper limit reference lifting control state. The selection command is given.

According to the second aspect of the present invention, when the raising / lowering instruction operation tool is switched to the raising instruction state in the manual mode, the raising / lowering instruction is given to enter the raising instruction state, and the ground portions of the left and right traveling devices are simultaneously raised to give the raising / lowering instruction. When the operation tool is switched to the descending instruction state, an elevating command is instructed to enter the descending instruction state, and the grounding portions of the left and right traveling devices are simultaneously operated to descend.
Also, by switching the up / down instruction operation tool to the left tilt instruction state,
When the left tilt instruction state is instructed to instruct a lift command to lean the vehicle body to the left, and when the up / down instruction operation tool is switched to the right tilt instruction state, a right tilt instruction state is instructed to instruct a lift instruction to tilt the vehicle body right. Then, when the lifting instruction operating tool is switched to the lifting stop state, a stop command is issued and the lifting of the vehicle body is stopped.

In the manual mode, switching between the descending instruction state and the ascending instruction state by the ascending / descending instruction operation tool gives an instruction to select between the lower limit reference elevating control state and the upper limit reference elevating control state in the automatic mode. Therefore, in the automatic mode, if the raising / lowering instruction operating tool is switched to the lowering instruction state, the lower limit reference lifting control state is set, and if the raising / lowering instruction operating tool is switched to the raising instruction state, the upper limit reference lifting control state is set.

According to the third aspect of the present invention, when the up / down instruction operation tool is switched to the left tilt instruction state in the automatic mode, the up / down drive means is actuated to lean the vehicle body to the left. When the up / down instruction operation tool is switched to the right leaning instruction state, the up / down drive means operates based on the instruction, and the vehicle body leans to the right.

〔The invention's effect〕

In the first aspect, the lifting instruction operating tool originally used in the manual mode can be used as selection means for switching the lifting control means between the lower limit reference lifting control state and the upper limit reference lifting control state in the automatic mode. Therefore, the number of operating tools is reduced. Therefore, the use of the operation tool in the manual mode and the automatic mode is simplified, and the confusing operation and the error are reduced. In addition, the dedicated space is reduced and the mechanical structure is simplified, which is advantageous in terms of maintenance.

According to the second aspect of the invention, in the manual mode, the grounding portions of the left and right traveling devices are simultaneously lowered to raise or lower the vehicle height, or the vehicle height is tilted to the right. It can be tilted to the left or to the left, and various operations can be freely performed by one manual lifting instruction operating tool. In the automatic mode, it is possible to switch to the lower limit reference lift control state by the descending operation of the lift instruction operation tool and to switch to the upper limit reference lift control state by the lifting operation, so that the operation becomes easy to understand. Therefore, operational confusion and mistakes are reduced.

In the third invention, since the manual mode is prioritized with respect to tilting the vehicle body to the right or to the left even though it is in the automatic mode, it is easy to respond to the work situation and quickly even in the case of frustration. I can deal with it.

〔Example〕

Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 9 shows a combine, which is an example of a work vehicle. This combine is a raising device (1) that causes planted grain culms, a mowing device (2) that mows the grain culms that have been raised, and a rear transportation device that conveys the mowing grain culms toward the rear threshing device (3). A cutting pretreatment device (5) including (4) and the like is provided on the front of a vehicle body, that is, a traveling machine body (7) including crawler traveling devices (6L) and (6R) as a pair of left and right traveling devices. It is attached by a lifting cylinder (26) so as to be vertically swingable around a horizontal support shaft (X).

Next, the attachment structure of the left and right crawler traveling devices (6L) and (6R) to the traveling machine body (7) will be described. As shown in FIGS. 7 and 8, a plurality of horizontally oriented frames (10) are attached at predetermined intervals in the front-rear direction below a main frame (9) formed by framing square pipe materials. The left and right track frames (11) are connected and fixed to both ends of the frame (10) to form a frame portion of the traveling machine body (7). A drive sprocket (12) for applying a drive force to the crawler (8) and a tension sprocket (13) for applying a tension to the crawler (8) are arranged in front of and behind the track frame (11).
The track frame (11) is formed in a channel shape that opens downward, and a pair of front and rear movable frames (15) pivotally supporting a plurality of idler wheels (14) in the open space.
A) and (15B) are mounted so that they can move in parallel. However, the front and rear movable frames (15A) and (15B) are connected so as to form one frame. A large diameter freewheeling body (16) capable of swinging up and down with respect to the track frame (11) is supported at an intermediate position of the group of freewheeling bodies (14).

Further, lower ends of front and rear bell cranks (17A) and (17B) pivotally supported by a track frame (11) so as to be vertically swingable are connected to the front and rear movable frames (15A) and (15B), respectively. , These front and rear bell cranks (17A), (17B)
The upper part of the is connected via a connecting rod (18). The lifting cylinders (19L) and (19R) for rolling are connected to the upper end of the rear bell crank (17B), and the lifting cylinders (19L) and (19R) control valves (VL) and (VR) are connected. A control device (20) unitized as a microcomputer is connected to (see FIG. 1). Then, when the control device (20) issues a lift command to the control valves (VL), (VR) and the lift cylinders (19L), (19R) expand and contract, the front and rear bell cranks (17A), (17B) swing integrally. As the front and rear movable frames (15A) and (15B) move up and down in the same direction by the same amount, the height of the ground contact portion of the left and right crawler traveling devices (6L) and (6R) relative to the traveling vehicle body (7) changes. I am doing it.

Elevating cylinders (19L) and (19R) for rolling, and a control valve (VL) with an electromagnetic solenoid that controls them,
(VR) and a pair of left and right crawler traveling device (6
L) and (6R) at least the grounding portions of the traveling machine body (7) can be individually lifted and lowered, and a lifting drive means (19
V).

As shown in FIG. 6, in the operating part of the traveling machine body (7), a mode changeover switch (SW) as a selection means for switching between a manual mode and an automatic mode and a control device (20) are used. A cross lever (21) for instructing a lift command to the lift drive means (19V) (an example of a lift instruction operation tool in the claims) is provided. The cross lever (21) is swingable back and forth and left and right, and is biased to return to the neutral position. As shown in FIG. 1, the swing lever (21a) lifts the lift switch (21a). ), The lowering switch (21b), the left tilting switch (21c), and the right tilting switch (21d) are operated to give an instruction to move up and down. In other words, in the neutral position, all the switches (21a to 21d) are not operated, and the elevator is stopped. If the lift switch (21a) is operated from the neutral position to the front, both the grounding parts are lifted to move the traveling body (7). ) Is instructed to descend, and if it is operated later from the neutral position, it is instructed to descend to lower both grounding parts to instruct the traveling body (7) to be lifted. If the left tilt switch (21c) is operated by operating it to the left, a left tilt instruction state is reached in which the traveling body (7) is tilted to the left, and the right tilt switch (21
When d) is operated, the state for inclining to the right to incline the traveling body (7) to the right is obtained.

As shown in FIG. 7, front and rear bell cranks (17
Limit switches (LSW) at both swing end positions of A) and (17B)
1) and (LSW2) are provided to detect whether or not the rear bell crank (17B) and then the lifting cylinders (19L) and (19R) for rolling have reached the end of the movable stroke. Here, the limit switch that detects the state where the crawler traveling devices (6L) and (6R) are at the most separated positions from the traveling machine body (7) is the upper limit switch (LSW).
1), the limit switch that detects the state of coming to the closest position is the lower limit switch (LSW2), and the detection results of these limit switches (LW ₁ ) and (LW ₂ ) are input to the control device (20). It has become.

As shown in FIG. 1, a tilt angle detection means (22) for detecting the left and right tilt angles of the traveling machine body (7) is provided. The inclination angle detecting means (22) is mainly composed of a weight that can swing to the left and right and a potentiometer that detects the swing position of the weight, and the detection information is the control device (20).
Is input to Further, as shown in FIG. 6, a tilt setting device (23) using a volume for setting a target tilt angle of the traveling machine body (7) is provided, and this setting information is input to the control device (20). It is like this.

Therefore, in the automatic mode, the control device (20) raises and lowers the driving means (19) so as to maintain the target tilt angle set by the tilt setting device (23) based on the tilt angle detection information.
V) will function as an elevating control means for instructing an elevating command. However, this control device (20) instructs the lifting drive means (19V) to move up and down based on the instruction information of the cross lever (21) in the manual mode, and also in the automatic mode, the cross lever (21). ) Lifting drive means (19V) based on the left tilting instruction information and the right tilting instruction information
It also functions as a control means for manual operation for instructing a lift command.

Here, a description will be given of the lifting control in the automatic mode.

The elevation control in the automatic mode is basically the difference (declination) between the detected value of the inclination angle detection means (22) and the target inclination angle (hereinafter simply referred to as a set value) by the inclination setter (23).
Then, the left and right crawler traveling devices (6L) and (6R) are moved up and down in a direction to reduce this difference, and rolling control is performed. This rolling control includes a descending reference elevating control state (hereinafter referred to as a lower limit reference mode) that brings the ground portions of the left and right crawler traveling devices (6L) and (6R) closer to the traveling body side, and the left and right crawler. Traveling device (6L),
(6R) There is an ascending reference elevating control state (hereinafter referred to as an upper limit reference mode) that separates each grounding part from the traveling vehicle body (7), and this mode switching uses the cross lever (21). It is supposed to be done. That is, in the automatic mode, if the cross lever (21) is operated forward from the neutral position, the lower limit reference mode is selected, and if it is operated backward from the neutral position, the upper limit reference mode is selected. In the lower limit reference mode, if the left / right inclination angle of the traveling vehicle (7) is within the dead zone with respect to the target inclination angle, the ground contact parts of the left and right crawler traveling devices (6L), (6R) are moved up and down to approach the traveling vehicle side. When the drive means (19V) is activated and the horizontal inclination angle of the traveling vehicle body (7) is within the dead zone with respect to the target inclination angle in the upper limit reference mode, the left and right crawler traveling devices (6L) and (6R) are grounded. The lifting drive means (19V) is operated so as to separate the section from the traveling body. That is, in the lower limit reference mode, rolling control is performed while making the ground height of the traveling body (7) as low as possible, and in the upper limit reference mode, the ground height of the traveling body (7) is made as high as possible. The rolling control will be performed while setting. The detailed control operation in each of the lower limit reference mode and the upper limit reference mode will be described later.

The control device (20) also has a function of raising and lowering the cutting pretreatment device (5) to maintain the cutting height at a set height. That is, as shown in FIGS. 1 and 9, an ultrasonic ground height sensor (25) is provided near the raising frame.
Is provided, and by controlling the control valve (26A) of the lifting cylinder (26) with the control valve based on the detection value of the ground height sensor (25), the ground height of the mowing pretreatment device (5) Cutting height setting device (27)
It is designed to maintain the height set by.

Reference numeral (23a) in FIG. 1 is a fine adjustment volume for outputting information for correcting the mounting error of the inclination angle detecting means (22) to the traveling machine body (7). The target tilt angle is set using the output information as well.

The rolling control will be described in detail below by explaining the operation of the control device (20) based on a flowchart. However, although the control device (20) also performs the processing for the elevation control for setting the cutting height as described in detail, only the rolling control will be described below. still,
Step numbers in the figure are indicated by a circle.

The main flow of rolling control is shown in FIG. First, when started, the timer and various flags are initialized. Then, when a predetermined time (about 10 mSEC) has elapsed, the output control for writing the contents of various flags to the output port is performed and the output flag is cleared. Then, the output values from the sensors such as the inclination angle detecting means (22) and the inclination setting device (23) are read. Next, the target tilt angle (target angle) is calculated. After the calculation is completed, execute the output evaluation process,
Return to step 2 (steps 1 to 7).

FIG. 3 shows a target angle calculation processing subroutine executed in step 6. A correction value is obtained from the output value of the fine adjustment potentiometer (23a), and the correction value is used to correct the set value of the tilt setting device (23) to set the target angle (steps 8 and 9). The fine adjustment knob (23
a) has already been set at the shipping stage.

Step 7 is shown in FIGS. 4 (a) and 4 (b).
This is a subroutine of the output evaluation processing executed in. However,
In the following description, leftward lowering, leftward raising, rightward lowering, and rightward raising mean the vertical operating directions of the left side portion and the right side portion of the traveling machine body (7). The cross lever (21) is not operated to the left or right, the automatic mode is selected by the mode switch (SW), the threshing switch is ON, and the cross lever (21) is operated backward. If so, the upper limit reference mode is set, and if the cross lever (21) has been operated previously, the lower limit reference mode is set (steps 11 to 17). That is, the cross lever (21) used in the manual mode is used as a switching tool for the upper / lower limit reference mode in the automatic mode.

However, if the cross lever (21) is operated to the left or right in step 11, the mode is temporarily switched to the manual mode (step 19). Further, if the manual mode is selected for the mode changeover switch (SW) in step 12, or if the threshing switch is turned off in step 13, the lower limit reference mode is set and the mode is switched to the manual mode (step 18 and
19) and proceed to step 60.

Shown in FIG. 5 is the manual mode subroutine executed in step 19. If the cross lever (21) is operated forward, the left lower solenoid output flag is set and the right lower solenoid output flag is set (steps 20 and 21) to lower the vehicle height of the traveling machine body (7). When the cross lever (21) is operated later, the left raising solenoid output flag is set and the right raising solenoid output flag is set (steps 22 and 23) to raise the vehicle height of the traveling machine body (7). When the cross lever (21) is operated to the left, the left lower solenoid output flag is set and the right up solenoid output flag is set (steps 24 and 25), and the traveling machine body (7) is tilted to the left. When the cross lever (21) is operated to the right, the left lower solenoid output flag is set and the right lower solenoid output flag is set (steps 26 and 27), and the traveling device (7) is tilted to the right.

When the lower limit reference mode or the upper limit reference mode is set in the automatic mode, first, the tilt angle detected by the tilt angle detection means (22) is subtracted from the target angle set in step 9 to calculate the declination angle (step 28).

In the lower limit reference mode, when the deviation polarity is positive and to the left, and the declination is outside the dead zone, the declination is significantly larger and the left lower limit switch (LSW2) is OFF. , Set the output flag of the left-lower solenoid and proceed to step 60 (steps 29 to 3).
Four). However, if it is determined in step 32 that the declination is small and that the left lower limit switch (LSW2) is ON (step 35), or step 33
When it is determined that the left lower limit switch (LSW2) is ON, the output flag of the right-up solenoid is set (step 36) and the process proceeds to step 60. Also, in step 35, the lower limit switch (LSW2) on the left is
If it is determined to be OFF, the process proceeds to step 60.

In the lower limit reference mode, the polarity of the declination is positive and rising to the left, but if the declination is in the dead zone and both the left and right lower limit switches (LSW2) are OFF, the right lower solenoid output flag and The left lower solenoid output flag is set and the process proceeds to step 60. If either the left or right lower limit switch (LSW2) is ON, the process proceeds to step 60 (steps 29 to 31, 37, 38).

In the lower limit reference mode, the polarity of the declination is negative, and when the declination is outside the dead zone, the declination is even greater and the right lower limit switch (LSW2) is off. If so, set the output flag of the right-down solenoid and proceed to step 60 (step 29
~ 30, 39 ~ 42). However, it is determined in step 40 that the deviation angle is small, and the lower limit switch (LSW2) on the right side
Is determined to be OFF (step 43),
If it is determined in step 41 that the right lower limit switch (LSW2) is ON, the output flag of the leftward raising solenoid is set (step 44) and the process proceeds to step 60. In step 43, the right lower limit switch (LS
If it is determined that W2) is ON, the process proceeds to step 60.

When the upper limit reference mode is selected, the polarity of the declination is positive, rising to the left, and the declination is outside the dead zone, this declination is significantly larger and the right upper limit switch (LSW1) is ON. For example, set the left-lower solenoid output flag and proceed to step 60 (steps 29, 45-4
9). However, if it is determined in step 47 that the deflection angle is small and that the right upper limit switch (LSW1) is OFF (step 50), or
If it is determined at 48 that the right upper limit switch (LSW1) is OFF, the output flag of the right-up solenoid is set (step 51) and the routine proceeds to step 60. Also, in step 50, the right upper limit switch (LSW1)
If it is determined to be ON, the process proceeds to step 60.

In the upper limit reference mode, the polarity of the declination is positive and to the left, but when the declination is in the dead zone and both left and right upper limit switches (LSW1) are OFF, the solenoid is raised to the right. The output flag and the left-raising solenoid output flag are set, and the routine proceeds to step 60. If either the left or right upper limit switch (LSW1) is ON, the routine directly proceeds to step 60. (Steps 29,45,4
6,52,53).

When the upper limit reference mode is set, the polarity of the declination is negative, and the declination is outside the dead zone, and the declination is significantly larger, and the left upper limit switch (LSW1) is ON, , Set the output flag of the right-down solenoid and proceed to step 60 (steps 29, 45, 54 ~
57). However, when it is determined in step 55 that the declination is small and the left upper limit switch (LSW1) is OFF (step 58),
If it is judged at 56 that the left upper limit switch (LSW1) is OFF, the output flag of the leftward raising solenoid is set (step 59), and the routine proceeds to step 60. Also, in step 58, the left upper limit switch (LSW1)
If it is determined to be ON, the process proceeds to step 60.

Next, as shown in Fig. 4 (b), if the left lower limit switch (LSW2) is ON, clear the left lower solenoid output flag and proceed to the next. If it is OFF, leave the left lower solenoid output flag as it is. And proceed to the next (Step 60,6
1). If the lower right lower limit switch (LSW2) is ON, clear the lower right solenoid output flag, proceed to the next, and turn OFF.
If so, the right down solenoid output flag is left as it is and the process proceeds to the next step (steps 62 and 63). If the left upper limit switch (LSW1) is ON, the left raising solenoid output flag is cleared and the process proceeds to the next step. If it is OFF, the left raising solenoid output flag is left as it is and the process proceeds to the next step (steps 64 and 65).
If the right upper limit switch (LSW1) is ON, the right-up solenoid output flag is cleared and the process proceeds to the next step. If it is OFF, the right-up solenoid output slug is left as it is and the flow returns to the main flow (steps 66 to 67).

[Another embodiment]

In carrying out the present invention, as a manual lifting instruction operation tool, four button switches corresponding to up, down, left and right may be used other than the cross lever. Also, a stroke sensor may be used instead of the upper limit switch (LSW1) and the lower limit switch (LSW2). In this case, there is an advantage that the algorithm can be configured by arbitrarily changing the upper limit position and the lower limit position.

Further, the present invention can be carried out not only on the combine, but also on, for example, a construction work vehicle or a snowmobile. Of course, it is also possible to use an agricultural work vehicle such as a rice transplanter whose traveling device is a wheel.

In the claims, reference numerals are provided for the purpose of simplicity with the drawings, but the present invention is not limited to the structure shown in the accompanying drawings.

[Brief description of drawings]

FIG. 1 shows an embodiment of a rolling control device for a work vehicle according to the present invention. FIG. 1 is an overall configuration diagram of lifting control means, FIG. 2 is a diagram showing a main flow, and FIG. 3 is a subroutine of target angle calculation processing. 4A and 4B show a subroutine of horizontal control processing, FIG. 5 shows a subroutine of a manual mode, and FIG. 6 shows a lifting instruction operating tool.
FIG. 7 is a side view of the crawler traveling device, FIG. 8 is a rear sectional view of the crawler traveling, and FIG. 9 is a side view of the combine. (6L), (6R) …… Traveling device, (7) …… Body, (19
V) …… Lift drive device, (20) …… Lift control means, (2
1) ...... Lifting / instructing operation tool, (22) ...... Inclination angle detecting means,
(SW) …… Selection method.

Claims (3)

[Claims] 1. A raising / lowering drive means (19V) capable of individually raising and lowering at least a grounding portion of each of a pair of left and right traveling devices (6L), (6R) with respect to a vehicle body (7), and the vehicle body (7).
Of a tilt angle detecting means (22) for detecting a left and right tilt angle of the vehicle, a manual lifting instruction operating tool (21) for instructing a lifting command to the lifting driving means (19V), and a tilt angle detecting means (22). Based on the information, a lift control means (20) for instructing a lift command to the lift drive means (19V) so as to maintain the target tilt angle, and the lift drive means (19V) by the lift instruction operation tool (21). ) To select a manual mode for instructing an elevating command and an automatic mode for instructing an elevating command to the elevating drive means (19V) by the elevating control means (20).
W) is provided, and the ascending / descending control means (20) causes the ground contact portions of the left and right traveling devices (6L) and (6R) to approach the vehicle body (7) side. And a rolling control device for a working vehicle configured to be freely switchable between an upper limit reference lift control state in which the ground portions of the left and right traveling devices (6L) and (6R) are separated from the vehicle body (7). Yes, in the automatic mode,
A rolling control device for a work vehicle configured such that the lift instruction operating tool (21) is configured to instruct the lift control means (20) to select a command between the lower limit reference lift control state and the upper limit reference lift control state. . 2. The rolling control device for a work vehicle according to claim 1, wherein the lifting instruction operating tool (21) simultaneously lowers the ground portions of the left and right traveling devices (6L), (6R). A descending instruction state for instructing a command, an ascending instruction state for instructing an instruction for simultaneously ascending the grounding portions of the left and right traveling devices (6L), (6R), and an elevating instruction for tilting the vehicle body (7) to the left. To the left, an instruction state for tilting to the left, an instruction state for tilting to the right to instruct a lift command for tilting the vehicle body (7) to the right, and a lift stop state. A rolling control device for a work vehicle configured such that commands for a descending instruction state and an ascending instruction state become selection commands for the elevation control means (20). 3. The rolling control device for a working vehicle according to claim 2, wherein the up / down instruction operation tool (21) is switched to a left tilt instruction state or a right tilt instruction state in the automatic mode. A rolling control device for a work vehicle configured such that the lifting drive means (19V) is operated based on a command.