JPH02124005A - Device for changing dead zone range of lifting and lowering position control of ground working machine - Google Patents

Abstract

PURPOSE:To eliminate a loss of engine horsepower in a nonoperating time without causing an error in positioning properties by changing an actuation dead zone range of an actuator corresponding to the position of a working machine. CONSTITUTION:During operation to lower a working machine 3 downward, an actuation dead zone range of an actuator 2 is narrowed to improve positioning accuracy. If the working machine 3 is lifted near the upper limit, the actuation dead zone range of the actuator 2 is extended. Thereby, a pump 18 is not actuated to the time of lowering within a specific range even if the working machine starts lowering in lifting and running the working machine without causing a loss in engine horsepower.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a lifting position control device for a ground-based work machine, which includes:
5. Related to a device for changing the dead zone width of actuator elevation control depending on the working condition 5 [Prior art] Conventional technology 5 Automatically changes the dead zone width of actuator operation when hoisting a ground work machine to a non-working position near the upper limit as in the present invention There was no widespread conversion.

If I were to cite a conventional method that is close in terms of sensitivity change, as shown in Japanese Patent Application Laid-Open No. 62-40206, hunting of the ground-based work equipment is detected when the ground-based work equipment is in the descending position in the working state. There is a method that changes the expansion and contraction speed of the actuator by changing the amount of high-pressure oil flowing to the actuator depending on the presence or absence of hunting.

[Problems sought to be solved by the invention] In order to improve the positioning performance of the work equipment, the dead zone of the conventional lift position control system can be reduced. If the ground work equipment attempts to descend under its own weight due to a leak, the upward correction is repeated each time, and pump pressure acts on the internal hydraulic circuit, resulting in a loss of engine horsepower.

In order to prevent these from occurring, it is necessary to make the dead zone larger than a certain level, and if it is made too large, there is a problem in that it causes an error in the positioning performance of the ground work machine.

[Means for solving the aI problem] This invention is an attempt to solve conventional problems with a simple configuration, and incorporates the following technical means. That is, the thing in claim (1) is the airframe 1
A ground work machine 3 is attached to the end of the actuator 2 so as to be freely movable downward in the L direction, and a proportional solenoid valve 4 for ascending control and a proportional solenoid valve 5 for descending control are provided as control valves for the actuator 2. In an apparatus that is provided with an operation sensor 6 that detects the operation and automatically controls the ascending and descending position of the ground-based work equipment 3, when the ground-based work equipment 3 is raised and during work, a When the dead zone A is set and the set position is changed to the non-working position C, which raises this ground work equipment 3 to near the upper limit, the actuator 2 is activated! j+ The configuration of the dead zone width changing device for controlling the elevation position of a ground work machine is characterized in that the width of the dead zone is changed to a second dead zone B in which the width of the dead zone is widened.

Further, in claim (2), a ground working machine 3 is attached to the end of the machine body 1 via an actuator 2 so as to be movable up and down, and a proportional solenoid valve 4 for ascending control is used as a control valve for the actuator 2. In a device that is equipped with a proportional solenoid valve 5 for descending control and an operation sensor 6 that detects the operation of the actuator 2, and automatically controls the ascending and descending position of the ground-to-ground machine 3, when the ground-to-ground machine 3 is raised and during work. Inside, the operation dead zone width of the actuator 2 is set to the first dead zone A, which is narrower, and once the ground work equipment 3 rises to the set position, the actuator 2 is not operated until the set position is changed next time. The structure of the vertical position control dead zone width changing device for a ground-based working machine is characterized in that the dead zone width is changed to a second dead zone B with a wider dead zone width.

In addition, claim (3) is characterized in that the non-working position C, in which the ground work equipment 3 is raised near the upper limit, is set by shifting the upper limit setting tool 7 downward. 1)
The structure of the insensitive cloth width changing device for controlling the elevation position of a ground-based work machine as described in 2.

[Function] During work when the ground work equipment 3 is lowered to the working position, the actuator 2 operates as a "first dead zone A" in which the operation dead zone width of the actuator 2 that raises and lowers the ground work equipment 3 is narrowed. Improves positioning accuracy without error for operation commands for raising and lowering.

From this working state, the ground work equipment 3 is set to move upward to the non-working position C, which is near the upper limit! When changing l\, the operation dead zone width of actuator 2 is changed to "second dead zone B" which widens the operation dead zone width, and even if actuator 2 drops a small amount due to leakage, the correction output is not output and the correction per hour is made. Reduce output.

In addition, when the set position for raising the ground work equipment 3 and the up movement position of the ground work equipment 3 become equal, the actuator 2 is converted into a "second dead zone B" in which the width of the actuation dead zone is widened, and the actuator 2 is slightly reduced due to leakage. Even if it descends, it does not output correction output and reduces the correction output per hour.

Also, the non-working position C when the ground work equipment 3 is raised near the upper limit.
is shifted downward by the upper limit setting device 7, this shifted ground work equipment holding setting position is regarded as the ground work equipment upper limit position, and at the same time as setting, the operation dead band width of the actuator 2 is widened "second dead zone B" Even if the actuator 2 drops a small amount due to leakage, the correction output per unit time is reduced without outputting the correction output.

[Effects of the Invention] With the above-described configuration, the present invention provides the following technical effects. In other words, the device described in claim (1) can be used simply by setting the ground-based working device 3 to a position close to the upper limit, and then the device 1 can be moved on the road or in the field. During turning movement, the operating dead band width of the actuator 2 is always converted to the second dead band B, which is wider, so when the ground work equipment 3 is hoisted, pressure oil leaks in the actuator 2 part and the ground work equipment 3 Even if the movement sensor 6 detects the actuation of the actuator 2,
Since the actuator 2 is not commanded to correct the upward movement, no pressure oil flows to the actuator 2 until the ground work equipment 3 has descended within a certain range, and an increase in oil temperature can be suppressed.

Next, the thing described in claim (2) is a ground work machine 3
When raising and during work, the actuator 2's operation dead band width is set to the narrow first dead zone (IIFA), and once the ground work equipment 3 rises and reaches the set position, Since the actuator 2 is converted into a second dead zone 8B with a wider operation dead zone width, pressure oil leaks in the actuator 2 section, the ground work equipment 3 starts descending relative to the aircraft 1, and the operation sensor 6 detects the actuator 2.
Since the actuator 2 is not commanded to correct the upward movement even if the operation of the above is detected, the pressure oil does not flow to the actuator 2 until the ground work equipment 3 descends within a certain range, making it possible to suppress a rise in oil temperature.

Further, at this time, when the set position of the ground work device 3 is changed, the width of the actuation dead zone of the actuator 2 is set to the narrow first dead zone A, so that positioning accuracy is improved.

Next, the thing described in claim (3) is a ground work machine 3
Upper limit setting tool 7 sets the non-working position F1C to near the upper limit.
You can set the lower upper limit position by shifting it downwards, so raise the ground work equipment 3 a little above the field surface! Even during work such as turning with the R center kept low, it is possible to raise the actuator 2 to the upper limit at a low position and at the same time convert it to a second dead zone B in which the actuation dead zone width of the actuator 2 is widened.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in this example are not intended to limit the scope of this invention to only those, unless there is a specific description. It's just an illustrative example.

The rotation was attached to a three-point linkage device 9 provided at the rear of the agricultural tractor 8. Ground work machine 3 which is a rotary tiller
This invention is incorporated into the elevation control section described later.

At the top of the transmission case at the rear of the machine body 1 of the agricultural tractor 8,
A hydraulic cylinder case 10 having a cylinder 2a and a piston 2b inside is attached.

The actuator 2 is composed of the cylinder 2a and the piston 2b, and the bell crank lla provided at the base end of the lift arm 11.11 protrudes outward from the hydraulic cylinder case 10 on both sides, and the actuator 2 expands and contracts. The lift arms 11, 11 are connected to a connecting rod 12 that transmits motion, and thereby the lift arms 11, 11 are vertically suspended around the shaft 13.

At the shaft 13 portion at the base end of this lift arm 11.

An actuation sensor 6 is attached to measure the swing angle of the lift arm 11 with respect to the body 1, calculates the expansion and contraction movement of the actuator 2, and transmits the result to the CPU 14.

The three-point link 9 to which the ground work equipment 3 is attached consists of an upper top link 14 and lower links 15, 15 on both sides of the lower part, and a link between the middle part of the lower link 15 and the tips of the lift arms 11, 11. left and right lift rods 16,
They are linked via 1G.

A ground work machine 3 is detachably attached to the rear end of these three-point links 9, and the vertical position and height of the ground work machine 3 is measured by an operation sensor 6 that measures the swing angle of the lift arm 11 with respect to the machine body 1. .

The actuator 2 consists of a cylinder 2a and a piston 2b, and causes high-pressure oil from a hydraulic pump 18 to flow into an oil chamber 17 via a lift control proportional solenoid valve 4 to lift the lift arm 11 until it reaches a target position, the action of which will be described later. When the lift arm 11 rises, the lift control proportional solenoid valve 4 is set to neutral, and the ground work machine 3 is suspended and held at the target position.

To lower the ground work equipment 3, the high pressure oil sealed in the oil chamber 17 is discharged into the tank 19 via the descending control proportional solenoid valve 5.
descends.

20.21 is a constant current circuit for rising and falling, and CP
U14, the proportional solenoid valve 4 for ascending control, and the proportional solenoid valve 5 for descending control are each independently electrically connected, and the CPU 1
The operation command from 4 is the constant current circuit 20 for raising and lowering.
．． 21 to open and close the proportional solenoid valve 4 for ascending control or the proportional solenoid valve 5 for descending control.

In the vicinity of the driver's seat 23 provided above between the rear wheels 22, 22, there is provided an operating lever 24 for setting the raising and lowering positions of the ground work equipment 3. The setting value of the potentiometer 24a,
It was provided on the shaft 13 at the base end of the lift arm 11. Anti-aircraft 1
In order to match the height detection value of the actuation sensor 6 that measures the swing angle of the lift arm 11 with respect to
and reaches the proportional solenoid valve 4 for ascending control or the proportional solenoid valve 5 for descending control. This automatic control is usually called position control.

Numeral 25 is a plowing depth setting device, which, like the operating lever 24, is equipped with a rotary potentiometer (not shown) at its base. The CP is adjusted so that the depth detection value of the tilling depth sensor 27 for calculating the tilling depth of a rotary tiller from the swing angle of the rotary tiller's pitcher 26 coincides with that of the rotary tiller.
Constant current circuit 2 for raising or lowering when the raising/lowering command is issued from U14
It is amplified by 0.21 and reaches the proportional solenoid valve 4 for ascending control or the proportional solenoid valve 5 for descending control. This automatic control is usually called depth control.

In addition to these operations, there is an operation normally called draft control, which is not shown but will be explained.

In the case of draft control, as with other position control and depth control, a drag force setting device (not shown) is provided near the driver's seat 23 of the fuselage 1, and the required target load is determined by a rotary potentiometer attached to the base. Set.

On the other hand, a load sensor (not shown) is provided on the base body 1 side of the top link 14 to detect the magnitude of the pushing force or tensile force acting on the top link 14, and the load sensor detects the set load of the drag setting device. Compare the magnitude of the load detected by
The detected value of the load sensor, which is the reaction force of the aircraft 1 during flight, which acts on the aircraft 1 is reduced until it matches the set load of the drag force setting device.

Conversely, when the detected load is small, a descending command from the CPU 14 is amplified by the descending constant current circuit 21, and the descending command is amplified by the descending constant current circuit 21.
The detected value of the load sensor, which is the reaction force acting on the aircraft 1 during forward movement, is increased until it matches the set load of the drag force setting device.

Reference numeral 28 is a work mode changeover board, which is a changeover switch for switching to the above-mentioned position control, depth control, draft control, or a mix control that mixes these. Only the device becomes operational.

7 is an upper limit setting device for raising the ground work equipment 3;

This is a setting device that shifts the upper limit position of the operating lever 24 that sets the lowering position downward. When working with the ground work equipment 3 lifted only to a low position, the operating lever 24 may be stopped at a fixed position, but this If the upper limit is set using the upper limit setting device 7, even if the operating lever 24 is moved to the highest position, the raised position of the ground work equipment 3 can be regulated, making operation easier.

Next, the expansion/contraction control of the actuator 2 will be explained.

FIG. 2 (graph) shows the upward movement (including a slight downward movement) of the ground work equipment 3 and the ``target setting value'' set by the rotary potentiometer 24a provided at the base of the operating lever 24. Shown as a difference.

In this second figure (graph), the vertical direction (Y axis) passing through the 0 point is
shows the flow rate of the pressure oil that operates the actuator 2, the displacement amount of the actuator 2 is shown in the lateral direction (X axis) passing through the 0 point, the upward displacement amount is shown on the right side of the Y axis, and the downward side displacement is shown on the left side of the Y axis. The displacement amount is shown, and the diagonal line with symbol d indicates the actuator 2 operating line when raising, and the diagonal line with symbol e indicates the actuator 2 operating line when lowering.

A situation in which the work of the ground work machine 3 is temporarily interrupted at the edge of a field will be described.

When the driver at the field edge operates the control lever 24 to the non-working position C, which raises the ground work equipment 3 near the upper limit, a rotary potentiometer 24a provided at the base of the control lever 24 activates the "target setting" function. "value Z" is set.

The greater the displacement between this target setting value 2 and the current position of the ground working machine 3, the greater the flow rate to the actuator 2, and the ground working machine 3 moves on the diagonal line d in the direction of arrow A.

As the target setting value 2 and the current position of the ground work equipment 3 become closer together as it moves in the direction of the arrow A, the actuator 2 on the diagonal line d
The movement gradually decreases until the vertical line a, which is the first dead zone A,
When the ground work equipment 3 reaches the part shown in FIG.
Rotary potentiometer 24 provided at the base of 4
By a, the "target set value Z" is set to a position near the upper limit, and at the same time, the vertical position control dead zone width is changed to the width of the second dead zone. "Target set value Z" is set by the rotary potentiometer 24a provided in D, and after the ground work equipment 3 rises and matches the target set value Z, the vertical position control dead zone width is changed to the second dead zone B. will be changed to

The above-mentioned first dead zone A is usually ±1.5 to 2 degrees in the operating angle of the lift arm 11 in the conventional mechanical type, but this is changed to ±0 degrees in the operating angle of the lift arm 11 on the same side.
．． I was able to reduce it to about 3 degrees.

If we continue to control the actuator 2 with this first dead zone A (conventional method), when the ground work equipment 3 is held at the raised position, a leak will occur in the actuator 2 and the lift arm 11 will be adjusted to the dead zone width. When it descends to -H, the output that corrects the rise of actuator 2 immediately changes to C.
When the ground work equipment 3 tries to rise a little, it enters the first dead zone A and output is stopped. This is output repeatedly twice in - seconds to correct the oil temperature. cause.

On the same side, as mentioned above, the non-working position C near this upper limit
When the target position is set, the operation start point of the actuator 2 is switched to the second dead zone B, so even if a leak occurs in the actuator 2, it will not move until it moves to the vertical line position along the arrow in the + direction on the X-axis. During the leak, actuator 2
Since no increase correction is instructed (increase correction is done approximately once every 5 minutes in actual measurement time), the rise in oil temperature has been reduced.

If the set value is changed, the first dead zone A is applied for both ascending and descending.
The width of the dead zone of the actuator 2 is reduced to 1/2 to 1/3 compared to the mechanical type.

What is described in claim (3) is a large ground work machine 3.
etc., when lifting the machine 1 to near the upper limit will change the balance of the machine 1 and make it difficult to operate, or when lifting the ground work machine 3 a little to perform turning or moving work, set the upper limit of the ground work machine 3 to the lift arm. Since the operating angle of No. 11 is shifted to the lower side, this upper limit setting tool 7
The target position can be converted to the second dead zone B the moment the target position is set using the set value set as the upper limit, and even when the ground work equipment 3 is lifted slightly and is rotated or moved, there is no leakage in the actuator 2 due to the normal gap. Even if leakage occurs, do not instruct the actuator 2 to perform upward correction until the leakage moves to the vertical line position along the arrow in the ten directions on the X-axis (
Actual measurement shows an increase of about once every 5 minutes. ), so you can continue working with less oil temperature rise.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention, in which Figure 1 is a relationship diagram between each sensor and actuator, Figure 2 is a diagram explaining the operation of the main parts, and Figure 3 is an overall side view. be. In the figure, numeral 1 is the aircraft body, 2 is the actuator, 3 is the ground work equipment, 4 is the proportional solenoid valve for ascending control, 5 is the proportional solenoid valve for descending control, 6 is the operation sensor, and 7 is the upper limit setting device.

Claims (3)

[Claims] (1) A ground working machine 3 is attached to the end of the body 1 so as to be able to move up and down via an actuator 2, and a proportional solenoid valve 4 for ascending control and a proportional solenoid valve 5 for descending control are provided as control valves for the actuator 2. , which is equipped with an operation sensor 6 that detects the operation of the actuator 2 and automatically controls the ascending and descending position of the ground-based work equipment 3, and when the ground-based work equipment 3 is raised and during work, the operation dead zone width of the actuator 2 is narrowed. When the setting position is changed to the non-working position C in which the ground work equipment 3 is raised to the vicinity of the upper limit, the first dead zone A is changed to the second dead zone B in which the actuation dead zone width of the actuator 2 is widened. A dead band width changing device for controlling the elevation position of ground-based work equipment. (2) A ground work equipment 3 is attached to the end of the machine body 1 via an actuator 2 so as to be able to move vertically, and a proportional solenoid valve 4 for ascending control and a proportional solenoid valve 5 for descending control are provided as control valves for the actuator 2. , which is equipped with an operation sensor 6 that detects the operation of the actuator 2 and automatically controls the ascending and descending position of the ground-based work equipment 3, in which the operation dead zone width of the actuator 2 is narrowed when the ground-based work equipment 3 is raised and during work. When the ground work equipment 3 rises and reaches the set position, the actuator 2 is changed to the second dead zone B in which the width of the actuator 2 is widened until the set position is changed. A vertical position control dead zone width changing device for ground-based work equipment. (3) The ground work machine according to claim 1, characterized in that the non-working position C in which the ground work machine 3 is raised to near the upper limit is set by shifting downward by the upper limit setting tool 7. Lifting position control dead zone width changing device.