JPH1052108A - Device for position control of working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rationally constitute a device for position control which does not carry out a lifting control by a degree of finger touching to a lever due to mistake, while enabling fine adjustments of the lifting control. SOLUTION: In this device for position control of a working vehicle, a position control device is constituted to carry out lifting of a tilling device until a signal reaches from a lift arm sensor within a neutral zone based on a preset signal from a lever sensor, and a neutral zone-adjusting means C, which brings a signal area for stopping a lifting movement of the tilling device narrower than the signal area of the neutral zone when the signal from the lever sensor goes beyond the signal area for starting based on the preset position of the lever sensor memorized in a memory, is installed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a setting device which is provided with a working device which can be raised and lowered by driving an actuator on a vehicle body, and which is operated by an operating tool for setting the height of the working device with respect to the vehicle body, The height of the work equipment is measured until the signal value from the body height sensor reaches a value corresponding to the control target set by the setting device. More specifically, the present invention relates to a technique for adjusting a width of a dead zone set according to a setting device at the time of elevating control.

[0002]

2. Description of the Related Art Conventionally, there is an apparatus disclosed in Japanese Patent Publication No. Hei 7-24487 as a position control device for a working vehicle constructed as described above. From the moment, in the embodiment, the control operation is set such that a narrow dead zone is set and the elevation control is performed from the moment when it is determined that the elevation operation has been performed by the position lever or the elevation switch.

[0003]

However, in the prior art in which the width of the dead zone is narrowed at the moment when the operation for raising and lowering is started, the vertical movement of the ground work machine with respect to the operation of the position lever is not described. Although the adjustment can be performed satisfactorily, even when the position lever is slightly touched by mistake during the operation and the position lever is slightly displaced, the elevation control is started, and there is room for improvement.

An object of the present invention is to rationally configure a position control device which enables fine adjustment of the elevation control but does not start the elevation control if the setting device is touched by mistake. is there.

[0005]

According to a first feature of the present invention, as described at the outset, a working device is provided which can be vertically moved by driving an actuator with respect to a vehicle body. A setting device operated by an operating tool that sets the height of the vehicle body, a body height sensor for feedback that measures the height of the working device relative to the body, and a value corresponding to the control target set by the setting device In a position control device of a work vehicle that drives and operates an actuator to raise and lower the work device until a signal value from the vehicle body height sensor reaches, a storage means for storing a set position set by the setting device; And a dead zone adjusting means for adjusting a signal range of a dead zone formed on the basis of a control target set by the control device, and a signal from the set device is operated by operating the operating tool with reference to a set position held in the storage means. When it is determined that the signal exceeds the preset signal area for activation, at least the working device based on the operation of the operating tool in the dead zone signal area formed based on the control target set by the setting device. The signal area on the side where the lifting / lowering operation is stopped is formed narrower than the signal area of the dead zone before the operating tool is operated, or the adjusting operation of the dead zone adjusting means is set to zero. The operation is as follows.

A second feature (claim 2) of the present invention is that, in claim 1, a signal area formed on one side based on a signal value from the setter in the signal area for starting, The control operation of the dead zone adjusting means is set so as to match the signal range set on the side where the lifting / lowering operation of the working device is stopped by the dead zone adjusting means. The operation is as follows.

[0007] A third feature of the present invention (claim 3) is that, in claim 1, the dead zone adjusting means sets a dead zone of a signal area of a predetermined width on the side where the lifting / lowering operation of the working device is stopped. Than the width of the dead band signal area set to
The point is that the width of the signal area formed on one side of the signal area for starting is narrowed based on the signal value from the setting device, and the operation is as follows.

According to a fourth feature of the present invention, the signal value from the vehicle height sensor when the actuator is driven is a dead band signal set based on the setting device. Control is performed such that the drive of the actuator is stopped at the timing when the signal reaches the setting signal value set by the setting device or the setting device, and the adjustment operation by the dead zone adjustment means is stopped to set the dead zone of the signal region set in advance. The operation is set, and the operation is as follows.

According to a fifth feature of the present invention (claim 5), when the driving of the actuator is stopped and the adjustment operation by the dead zone adjusting means is stopped in claim 4, the detection from the vehicle height sensor is performed. In the case where the signal value has reached a value equal to or higher than the predetermined height, the control operation is set so as to set a dead zone of a signal area having a wider width than the signal area in the case where the signal value is equal to or lower than the height value. The operation is as follows.

According to the first feature, when an operating tool is operated, a signal from a setting device operated by the operating tool is set based on a set position held in a storage means. When the dead-zone adjusting means determines that the signal has exceeded the starting signal area, the dead-zone adjusting means makes the signal area of the dead zone narrower than the signal area of the dead zone before the operation tool is operated (including zero). ), The working device can be moved up and down in response to fine adjustment of the operating tool. In other words, in this configuration, the width of the dead zone does not become narrower unless the operation tool is operated by a predetermined amount or more, so that it is possible to avoid the inconvenience that the elevation control is started even when the operation tool is touched by mistake, At the time of control, the working device can be moved up and down to a height close to the control target in response to a slight operation of the operating tool.

According to the second feature, the signal area for activation for starting the lifting and lowering of the working equipment coincides with the signal area of the dead zone for stopping the lifting and lowering operation of the working equipment, so that the width of each signal area is extremely small. Operation amount when starting up / down control when operating the operation unit,
The balance between the lifting and lowering operation and the amount of operation up to the stop is balanced.

According to the third feature, since the signal area for starting is set narrower than the signal area of the dead zone, it is delicate when starting up / down by operating the operating tool from the state where the lifting / lowering of the working device is stopped. As a result, the working device can be stopped at a high speed without causing overshoot.

According to the fourth feature, a wide dead zone is set in a state where the lifting / lowering operation of the working device is stopped. Therefore, for example, the working device vibrates up and down due to external vibration, and this vibration is counteracted. Even if the vehicle height sensor measures, the elevation control is not performed.

According to the fifth feature, when it is detected that the working device is at a high position when the lifting / lowering operation of the working device is stopped, a dead zone having a wider width is set as compared with the case where the working device is at a low position. Therefore, for example, a situation occurs in which the working device is largely vibrated up and down as in the case where the working device is raised to the upper limit and the vehicle body runs at high speed on the road, and the vibration is measured by the body height sensor. Even if it does, the elevation control is not performed.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, an engine 4 is arranged at a front part of a vehicle body 3 having a front wheel 1 and a rear wheel 2,
A transmission case 5 to which the power from the engine 4 is transmitted is disposed at the rear of the vehicle body 3.
The driver's seat 7 is arranged at an intermediate position between the left and right rear fenders 6 above the vehicle, a steering handle 8 is arranged at the front of the driver's seat 7, and a three-point link mechanism L is provided at the rear end position of the vehicle body 3. The rotary tilling device 9 (an example of a working device) is vertically and freely rolled to form a farm tractor as a working vehicle.

The three-point link mechanism L comprises a single top link 10 and a pair of left and right lower links 11, 11. A single-acting lift cylinder 12 (of an actuator) is disposed above the transmission case 5. The pair of left and right lift arms 13, which are lifted and lowered by the drive of one example), and the lower links 11, 11 of the three-point link mechanism L are connected via left and right lift rods 14, and are supported in a suspended state. Further, by interposing a double-acting rolling cylinder 15 on one of the lift rods 14, the lifting and lowering of the rotary tilling device 9 by driving the lift cylinder 12 and the rolling of the rotary tilling device 9 by driving the rolling cylinder 15 are performed. It is freely configured.

As shown in FIGS. 1 and 2, a position lever 16 as an operating tool for raising and lowering the rotary tilling device 9 is arranged on the right side of the driver's seat 7, and is provided at a base end of the position lever 16. A potentiometer-type lever sensor 17 (an example of a setting device) for measuring the operation position of the lever 16 is provided, and the rotary tilling device 9 is mounted on the base end of the lift arm 13 based on the swing posture of the lift arm 13.
Is provided with a potentiometer type lift arm sensor 18 (an example of a vehicle height sensor) for measuring the vehicle height. The tractor includes a control unit 19 to which a signal from the lever sensor 17 and a signal from the lift arm sensor 18 are input, and a position control device including an output signal system for controlling the solenoid valve V from the control unit 19. It has.

The control unit 19 includes a microprocessor (not shown) in which a program for executing the position control described below is set, and has a built-in memory 20 as storage means. The solenoid valve V is connected to the control unit 19
Is opened and closed by a signal from the hydraulic pump P to supply hydraulic oil from the hydraulic pump P to the lift cylinder 12 to control the raising of the rotary tilling device 9 and stop supplying and discharging the hydraulic oil to raise the rotary tilling device 9 to its height. The control to maintain and the lowering control of the rotary tilling device 9 can be performed by draining the oil from the lift cylinder 12.

In the control section 19, even when the position lever 16 is operated small during the position control for setting the height of the rotary tillage device 9 with respect to the vehicle body by operating the position lever 16, the operation amount of the position lever 16 is reduced. Correspondingly, the rotary tilling device 9 can be moved up and down by a small amount, so-called inching, and when the lifting and lowering of the rotary tilling device 9 is stopped, the position control is performed even if the lift arm 13 vibrates up and down due to external vibration. The lifting and lowering control of the rotary tillage device 9 is not performed.

That is, the basic operation of the position control is represented as shown in the flowchart of FIG. 9. When the control is started, the initial setting is first performed, and then the lever sensor 1 is set.
The signal from the position sensor 16 is compared with the signal value from the lever sensor 17 stored in the memory 20 by inputting the signal from the position lever 16.
It is determined whether or not has been operated up to an area beyond the signal area set in advance (# 101 to # 103 steps).

The initial setting (step # 101) is performed when the position control is started, for example, immediately after the start of the engine 4. In this initial setting, a signal from the lever sensor 17 is input and the control is started. As shown in FIG. 3, the current setting position R of the position lever 16 is
A control operation to be held in the memory 20 on the basis of the voltage signal from the controller 20 and a target posture T of the lift arm 13 are set as shown in FIG. When the lift arm 13 is at or below a preset posture (height) based on a signal, the dead zone N formed based on the target posture T
The region ND on the side where the lowering operation of the lift arm is stopped and the region NU on the side where the raising operation of the lift arm is stopped are formed with a standard width based on the target posture T, and the lift arm 13 is set in advance. When the position is higher than the set posture (height), the dead zone N formed on the basis of the target posture T is shifted to a region ND on the side where the lowering operation of the lift arm 13 is stopped.
And the region N on the side where the lifting operation of the lift arm 13 is stopped
U is formed equally with a width that is twice as large as the target posture T (see FIG. 8 and related description will be described later).

Assuming that the position of the position lever 16 stored in the memory 20 is R as shown in FIG. 1, the preset signal area corresponds to an area where the position lever 16 is represented by strokes M and M. That the region M, M is exceeded in any direction means that the voltage value from the lever sensor 17 exceeds the region M, M based on the voltage value corresponding to the position R stored in the memory 20. The determination is made at the time when the value has changed to a value exceeding the value.

Next, only when it is determined that the position lever 16 has been operated beyond the signal range set in advance, the control section 19 controls the control target set based on the signal from the lever sensor 17; That is, the side of the dead zone N set based on the target posture T of the lift arm 13 for stopping the raising / lowering operation (the area NU on the side where the raising operation is stopped when the position lever 16 is operated to the raising side) is illustrated. 5
Is set to 1/2 (50%) of the width as shown in (# 10)
4, # 105 step).

This control operation enables inching. For example, when the posture of the lift arm 13 coincides with the target posture T, the position lever 16 is set in advance from the stored position R to the ascending side. When the operation is performed slightly beyond the area M, the target posture T of the lift arm 13 is displaced upward, and at the same time, as shown in FIG. The width of the area M and the area N for stopping the rising of the dead zone N so that the lower boundary of the NU coincides with the current posture of the lift arm 13.
By setting the relationship with U, the followability of the lift arm 13 to the operation of the position lever 16 is set high. Even if the control operation is set in this way,
When the initial posture of the lift arm 13 does not match the target posture T corresponding to the stored position R, the elevating operation may not be performed even when the position lever 16 is operated.

In this position control, when the lift arm 13 reaches the dead zone N by the lifting operation, the lifting operation is stopped at any position in the dead zone N, and the lifting operation is stopped. In many cases, the posture of the lift arm 13 does not coincide with the target posture T in the state of being in the state. Therefore, in a state where the posture of the lift arm 13 exists on the ascending side from the target posture T, for example, the position lever 16
If the width of each of the area NU for stopping the raising operation and the area ND for stopping the lowering operation is simultaneously reduced when the operation is performed on the ascending side beyond the preset area M, the area is controlled at the narrowed timing. There may be a disadvantage that the lowering operation is performed due to the posture of the lift arm above the ND. In order to prevent such inconvenience, when the position lever is operated beyond the preset area M, as shown in FIG. 5, the side on which the lifting and lowering operation of the rotary tillage device 9 by this operation is stopped. Only the width of the dead zone is reduced.

Next, it is determined whether the signal value from the lift arm sensor 13 is outside the dead zone N. If the signal value is outside the dead zone N, the signal value of the target posture T and the signal value from the lift arm sensor 18 are compared. Lift cylinder 1 on the side where the deviation becomes smaller
2 to drive the rotary tillage device 9 up and down, and when the signal value from the lift arm sensor 18 is outside the dead zone N, the lifting operation is stopped (if already stopped, stop. Maintain state). When the lifting operation is stopped after the lifting and lowering operation of the rotary tilling device 9, a signal from the lift arm sensor 18 is input, and the lift arm 17 is set at a preset posture (set height) set near the upper limit in advance. It is discriminated whether it is on the high side or on the low side with reference to the reference position, and if it is on the low side, the regions NU and ND of the dead zone N having the standard width are set on both sides with reference to the target posture T. When it is formed and located on the side higher than the set attitude (set height), the dead zone N having the standard width with reference to the target attitude T
NU, ND of dead zone N with width twice as large as
Are formed on both sides, and the signal value from the lever sensor 17 at the time when the raising / lowering operation is stopped is written into the memory 20 to update the signal value, and this control is continued until the control is reset ( # 106 to # 116 steps).

This control operation will be described by taking as an example the case where the position lever 16 is operated to the ascending side. As shown in FIG. 6, when the posture of the lift arm 13 reaches the dead zone NU for stopping the ascending, the lift is lifted. The ascending drive by the cylinder 12 is stopped, and after this stop, as shown in FIG. 7, the dead zone ND for descending stop and the dead zone NU for ascending stop are returned to the original position based on the target posture T of the lift arm 13. The width is set to be equal, and at the same time, the attitude of the position lever 16 is held in the memory 20. If the target posture T of the lift arm 13 is higher than a preset height at the time when the respective dead zones ND, NU are set, as shown in FIG. 8, the respective dead zones ND, NU are set. The width of the NU is set to be twice as large as the standard width.

Further, the control for restoring the width of the dead zone N to the standard width after the lifting control is stopped is performed in a state in which the rotary tilling apparatus 9 vibrates up and down due to external vibration in a state where the lifting control is not performed. This is for the purpose of avoiding a phenomenon in which the signal from the sensor 18 deviates from the dead zone N and the position control is temporarily performed. Further, when the posture of the lift arm 13 is higher than the set posture, the width of the dead band N is reduced. In the control for setting the width larger than the standard width, the rotary tilling device 9 is often run on the road at a relatively high speed in a state where the rotary tilling device 9 is raised to near the upper limit. 13, the rotary tilling device 9 vibrates up and down greatly, and the signal from the lift arm sensor 18 is out of the dead zone, and the position control is temporarily performed. It is purpose from which to avoid.

It is determined that the position lever 16 has been operated by a predetermined amount or more from the position stored in the memory 20, and a control operation for raising and lowering the lift arm 13 is performed.
The step 103 and the step # 104 constitute the dead zone adjusting means C of the first aspect.

As described above, in the present invention, when performing position control, the width of the dead zone is reduced when the position lever 16 is operated by a predetermined amount or more. The lift arm 13 can be moved up and down with good follow-up, and the lift arm 13 can be moved up and down to a position very close to the control position T set by the position lever 16 to stop. Is stopped, the dead zone N is restored to the original width, and when the rotary tilling device 9 is raised to a high position where it does not touch the ground, the dead zone N having a further expanded width is set. Does not cause the lift arm 13 to move up and down even if it vibrates up and down.

[Other Embodiment] In addition to the above-described embodiment, the present invention, as shown in FIG. 10, for example, when the position lever 16 is operated to the ascending side beyond the set range, the dead zone NU for stopping the ascending. Can be set to zero. In this way, by setting the control operation of the dead zone adjusting means C so as to set one width of the dead zone to zero, the elevation control of the lift arm is performed until the attitude of the lift arm almost coincides with the target attitude. It is also possible to do.

Further, in the present invention, for example, based on a state in which the target posture T of the lift arm 13 set based on the position of the position lever 16 at the non-operation position and the actual posture of the lift arm 13 match, , Position lever 1
When the position lever 16 is operated on the ascending side and the position lever 16 is operated and exceeds the set area M, the area ND of the dead zone N for ascending and stopping formed based on the target attitude T of the lift arm 13 is It is also possible to set the control operation of the dead zone adjusting means C so as to be located at a position higher than the actual posture, and if the control operation is set in this way, it is possible to realize more delicate elevation control.

Further, it is possible to set a value other than 1/2 to narrow the areas NU and ND of the dead zone N, and to set a value other than twice to enlarge the areas NU and ND of the dead zone N. It is also possible to simultaneously narrow the areas NU and ND of the dead zone N.

[0034]

As a result, a position control device which enables fine adjustment of the elevation control but does not start the elevation control when the setter is accidentally touched by a hand has been rationally constructed. Claim 1). Further, the lifting and lowering control can be performed with a reasonable operation feeling (claim 2), and the working device can be raised and lowered while enabling fine control of the height from a stopped state of lifting (claim 3). A state in which the height of the working device is stably maintained while the lifting operation is stopped while the height of the working device can be finely adjusted (claim 4), and the working device is raised to the upper limit and suspended. Thus, even when the vehicle travels on rough ground, the lifting / lowering control is prevented, and the working device can be stably held at that position (claim 5).

[Brief description of the drawings]

FIG. 1 is an overall side view of a tractor.

FIG. 2 is a block circuit diagram of a control system.

FIG. 3 is a schematic diagram showing a relationship between a position lever and a lift arm in a non-operation state.

FIG. 4 is a schematic diagram showing a relationship between a target posture and a dead zone when the position lever is operated to a posture slightly over an area M;

FIG. 5 is a schematic diagram showing a relationship between a target posture and a dead zone when the position lever is operated to a posture beyond an area M;

FIG. 6 is a schematic view showing a relationship between the position lever and the lift arm when the lift arm operates until reaching a dead zone.

FIG. 7 is a schematic diagram showing a relationship between a region M and a dead zone when the control operation of the lift arm is stopped.

FIG. 8 is a schematic diagram showing a relationship between a region M and a dead zone when the posture of the lift arm is higher than a predetermined posture when the control operation of the lift arm is stopped.

FIG. 9 is a flowchart showing a control operation.

FIG. 10 is a schematic diagram showing a relationship between a target posture and a dead zone when a position lever is operated to a posture beyond a region M in another embodiment.

[Explanation of symbols]

 Reference Signs List 3 vehicle body 9 work device 12 actuator 16 operating tool 17 setting device 18 body height sensor 20 storage means C dead zone adjusting means N dead zone

Claims (5)

[Claims] An operating device is provided on a vehicle body for driving the actuator up and down by driving an actuator, and a setting device operated by an operating tool for setting the height of the operating device with respect to the vehicle body; And the actuator is driven to raise and lower the working device until the signal value from the body height sensor reaches a value corresponding to the control target set by the setting device. What is claimed is: 1. A position control device for a work vehicle, comprising: storage means for storing a set position set by the setting device; and dead zone adjustment for adjusting a signal range of a dead zone formed based on a control target set by the setting device. Means, and when it is determined that the signal from the setting device has exceeded a preset signal area for activation based on the set position held in the storage means by operating the operation tool, the setting is performed. vessel Among the signal ranges of the dead zone formed on the basis of the set control target, at least the signal range on the side for stopping the lifting / lowering operation of the working device based on the operation of the operation tool is a signal zone of the dead zone before the operation tool is operated. A position control device for a working vehicle, wherein the adjusting operation of the dead zone adjusting means is set to be narrower or zero. 2. A signal area formed on one side based on a signal value from the setting unit in the signal area for starting, and a signal area set on a side for stopping a lifting / lowering operation of a working device by the dead zone adjusting means. 2. The position control device for a working vehicle according to claim 1, wherein a control operation of said dead zone adjusting means is set so as to match a signal area to be performed. 3. A dead zone having a predetermined signal range is set on the side where the lifting / lowering operation of the working device is stopped by the dead zone adjusting means, and the starting zone for the starting is determined from the width of the signal zone of the dead zone thus set. 2. The position control device for a work vehicle according to claim 1, wherein a width of a signal area formed on one side of the signal area is set to be narrow based on a signal value from the setting device. 4. A signal value from the vehicle height sensor when the actuator is driven reaches a signal range of a dead zone set based on the setting device or a setting signal value set by the setting device. 2. The position control device for a work vehicle according to claim 1, wherein the drive of the actuator is stopped at a timing, and the control operation is set so as to stop the adjustment operation by the dead zone adjustment means and set a dead zone in a preset signal range. 5. The driving of the actuator is stopped,
When the adjustment operation by the dead zone adjusting means is stopped, if the signal value from the vehicle body height sensor has reached a value equal to or greater than a predetermined height, a signal indicating that the height value is equal to or less than this value. 5. The position control device for a working vehicle according to claim 4, wherein the control operation is set so as to set a dead zone of a signal range having a width wider than the range.