JPH10155309A - Elevating and lowering device for work machine in tractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an elevating and lowering device for improving traveling stability and operability without accompanying rapid acceleration-deceleration movement by changing the elevation upper limit height of a work machine based on a detected value obtained in a control means for detecting the front, back, left and right inclination states of a tractor main body. SOLUTION: For the work machine 3 freely vertically movably connected through a three-point link 2 to the rear part of a tractor 1, the upper limit and lower limit heights of the vertically driven work machine 3 are controlled by the variable setting of a controller provided in a drive operation part. The control means for detecting the front, back, left and right inclination states of the main body of the tractor 1 is provided and the elevation upper limit height of the work machine 3 is changed based on the detected value obtained in the control means. Also, it is preferable to freely variably provide the elevation control volume of the work machine 3 in the controller and to convert the detected value obtained in the control means to the upper limit height set value of the elevation control volume.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lifting and lowering device for a working machine in a tractor which holds a working machine mounted on a rear portion of a tractor in a vertical working posture according to a working purpose.

[0002]

2. Description of the Related Art Conventionally, a tractor is configured to raise and lower a working machine mounted on a rear part of a machine body via a three-point link to a vertical working posture suitable for the working purpose. Normally, by adjusting the ascent control volume provided in the operation section, the type of the work machine, or the presence or absence of the inclination of the field on which the tractor travels, and the like, restricting the ascending upper limit position of the work machine by the elevating lever, The running stability of a tractor equipped with a working machine and the safety of field work are ensured.

[0003] However, since the above-mentioned lift control volume only regulates the working machine mounted on the tractor to a certain upper limit position, when the lift operation is performed by the lift lever, the lift control volume is controlled by the lift control volume regardless of a change in the field on a sloped or flat ground. The work implement rises to the set height, and the tractor has a drawback that the stability of the tractor is reduced particularly when the tractor travels on a slope where the balance of the center of gravity of the tractor body is lost.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned situation and has been made in order to solve the conventional problems. In response to the degree of inclination of the slope, the position of the work implement is automatically controlled to the optimal upper limit position in accordance with the degree of inclination of the slope. Even when the tractor travels from a flat field scene to a sloped field scene without the need for troublesome control operations such as operation, the working position of the work machine with respect to the sloped surface can be appropriately maintained, and smooth operation can be performed. An object of the present invention is to provide a lifting device for a working machine in a tractor capable of performing field work.

[0005]

In order to achieve the above-mentioned object, the technical means adopted by the present invention is for a working machine which is connected to a rear portion of a tractor so as to be able to move up and down via a three-point link.
In a lifting device for a working machine in a tractor, the upper and lower limits of the working machine to be driven up and down are controlled by a variable setting of a control device provided in a driving operation unit. Control means for detecting a state is provided, and the upper limit height of the working machine is changed based on a detection value obtained by the control means.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. In FIG. 1, 1 is a front wheel 1a,
An agricultural tractor 2 having a rear wheel 1b, a three-point link 2 provided at the rear of the tractor 1, a working machine 3 mounted on the rear of the tractor 1 via the three-point link 2, and a cultivator as the working machine 3 Is exemplified.

The three-point link 2 automatically connects the work equipment 3 at four points of the output shaft 1c of the tractor 1, and has a base end side pivotally attached to the rear surface of the hydraulic case 4 of the tractor 1 for vertical rotation. A freely movable lift arm 5, left and right lower links 7, 7 having base ends pivotally attached to both side surfaces of a gear case 6, and a lift rod between each of the lower links 7, 7 and the distal end of the lift arm 5. Each of the three-point link 2 is configured by interposing the lower and upper arms 8 and 8 ′, and the lift rod 8 ′ interposed between one of the lower links 7 and the lift arm 5 is configured to extend and retract the work machine. And the working posture of the working machine 3 is maintained parallel to the horizontal plane of the field, upward and downward, and downward by the change in the amount of expansion and contraction of the working machine lifting cylinder 9. It is attached to the cylinder 9 for lifting and lowering the work equipment. The lift sensor 10 is configured to transmit a change in the amount of expansion and contraction of the work machine elevating cylinder 9 to the elevating controller 11.

[0008] The operation unit 1 of the agricultural tractor 1
2, as shown in FIG. 2, an ascending regulation volume 13 for controlling the upper and lower limits of the height of the working machine 3;
When the agricultural tractor 1 travels on a slope, an automatic tilt changeover switch 14 for enabling or disabling the automatic control set by the elevation control volume 13 is provided on the operation panel 15 together with other control switches and operation levers. In the setting operation with the above-mentioned rise control volume 13,
The upper and lower limit positions of the working posture suitable for various working machines 3 are manually or automatically controlled.

Further, a pitching sensor (not shown) for detecting an inclined state of the main body of the agricultural tractor 1 before and after traveling is provided on a hydraulic case 4 located at a rear portion of the agricultural tractor 1.
And a body sensor 16 equipped with a rolling sensor (not shown) for detecting a tilting state in the traveling left-right direction. The agricultural tractor 1 was driven in a sloping field scene by enabling the automatic tilt changeover switch 14. If the body sensor 1
6 is transmitted as a detection signal to the elevation control unit 11 and the slope inclination angle θs (described later) of the field scene in which the agricultural tractor 1 travels is calculated based on the detection signal. Irrespective of the setting of the upper limit position of the working machine 3 by the regulating volume 13, the amount of expansion and contraction of the working machine elevating cylinder 9 is regulated, and the upper limit height of the working machine 3 is automatically controlled.

Next, a method of calculating the slope inclination angle θs based on the detection signal from the machine sensor 16 will be described.
In FIG. 3, θy: advancing direction angle S: a slope inclined forward in the arrow direction from the near side to the front as shown T: a traveling direction of an agricultural tractor traveling down slope S at a traveling direction angle θy θp: detected by a pitching sensor Angle change value of the agricultural tractor in the front-rear direction, which is detected θr: Angle change value of the agricultural tractor in the left-right direction detected by the rolling sensor Pl: Reference tilt length by the pitching sensor Rl: Reference tilt length by the rolling sensor Ph: Reference tilt The amount of inclination of the agricultural tractor in the front-rear direction relative to the length Pl Rh: The amount of inclination of the agricultural tractor in the lateral direction of travel relative to the inclination reference length Rl x: The slope S of the inclination reference length Pl derived from the traveling direction angle θy
Length y: slope S of inclination reference length Rl derived from traveling direction angle θy
Is the unknown slope inclination angle, and the following relationship holds from the above values.

(Equation 1) Also,

(Equation 2) Further, since the slope inclination angle θs calculated by the above equation 1 and the slope inclination angle θs calculated by the equation 2 are equivalent, by detecting the angle change value θp and the angle change value θr with the body sensor 16, The traveling direction angle θy is

(Equation 3) Is required.

Here, the control operation of the elevation control unit 11 will be described. As shown in FIG. 4, the slope inclination angle θs obtained by the above-described equations (1) to (3) is changed. As the size of the lift arm becomes larger, that is, as the slope becomes steeper, the upper limit value of the rise control data is reduced. Based on this, as shown in FIG. 5, the upper limit value of the lift arm 5 in the flat field scene is set. Vmin of the rising regulation volume 13 (= 0
The lift height (indicated by a dotted line) of the lift arm 5 that is changed by a change in the voltage value from V) to Vmax (= 5 V) is determined by the height of the lift arm 5 at a voltage value Vd corresponding to the upper limit value of the lift control data. The control operation is performed so as to limit the position (shown by a solid line).

Since the present invention is configured as described above, when the upper limit position of the work machine 3 is set in advance by the rise control volume 13 and the automatic tilt changeover switch 14 is turned on to cause the agricultural tractor 1 to work and run, As shown in the flowchart of FIG. 6, first, it is determined whether or not the ascent control is effective. Then, when the vehicle is running on a flat field scene, the ascent control position is calculated by the ascend control volume 13, After comparing the current position of the lift arm 5 with the calculated value of the elevation restriction position, the working machine lifting / lowering cylinder 9 (lift rod 8 ′) is telescopically driven based on the result of the comparison, and the working machine 3 is moved to an appropriate upper limit. Automatically position at height.

When the vehicle is traveling in a field scene consisting of a slope, after the above-described calculation of the slope inclination angle θs by the body sensor 16 and the calculation of the corresponding rise restriction position with the rise restriction volume 13, The working machine lifting / lowering cylinder 9 (lift rod 8 ') is driven to expand and contract, and the working machine 3 is automatically positioned at an appropriate upper-limit upper limit height. Then, when the traveling direction of the agricultural tractor 1 and the inclination angle of the slope change, the traveling direction angle θy and the slope inclination angle θs are sequentially calculated by the detection signal from the body sensor 16, and the work implement elevating The expansion and contraction drive of the cylinder 9 is automatically performed, and the upper limit height of the work machine 3 is changed regardless of the setting of the lift control volume 13.

Therefore, even when the agricultural machine tractor 1 travels on a steep slope with the work implement 3 being positioned at the upper limit height set by the elevation control volume 13, the work implement 3 is automatically moved to the proper upper limit position. And the center of gravity of the tractor main body can be maintained at a low level at a proper shock-elevating speed without a sudden acceleration / deceleration operation of the working machine elevating / lowering cylinder 9, thereby improving the running stability of the agricultural tractor 1. Can be secured.

FIG. 7A shows an embodiment of the control structure of the rise regulating volume 13 comprising a variable resistor disposed on the operation panel 15. As shown in FIG. In the figure, an A / D converter 17, a comparison operation unit 18, a tilt angle operation unit 19, and a D / A converter 20 are built in a CPU in the elevation control unit 11, and an elevation control volume is provided as an external input. 13, a voltage output line 13a, an output line 21 of a pitching sensor built in the body sensor 16, and an output line 22 of a rolling sensor are connected. Further, the working machine lifting / lowering cylinder 9 via a hydraulic drive mechanism 23 is used as an external output by the CPU. It is connected to the.

The control operation according to the above configuration will be described.
First, the rising regulation volume 13 is set to the voltage value Vd shown in FIG.
Is converted to a digital data amount corresponding to the following equation, and the calculation of the slope inclination angle θs based on the sensor input from each of the output lines 21 and 22 is performed by the inclination angle calculation unit 19 according to the above-described equations 1 to 3. The calculated increase regulation data corresponding to the slope inclination angle θs is calculated as a reference value.

Then, the voltage value Vd of the ascending regulating volume 13 converted into the digital data amount and the ascending regulating data corresponding to the above-mentioned slope inclination angle θs are compared with each other by a comparison operation unit 18
The difference amount of the digital data amount based on the comparison result is sent to the hydraulic drive mechanism 23 via the D / A converter 20 to drive the work machine lifting / lowering cylinder 9 to expand and contract.

When digital data having a data amount exceeding the ascent control data serving as a reference value in the comparison operation section 18 is input from the A / D converter 17, that is, in a state where the slope inclination angle θs does not change. When the rise control volume 13 is turned in the direction of the maximum voltage value Vmax, digital data corresponding to the rise control data serving as the reference value in the comparison operation unit 18 is transmitted via the D / A converter 20 to the hydraulic drive mechanism. 23, and the work machine lifting / lowering cylinder 9 is shown in FIG.
Is maintained at a constant lift arm height defined by the voltage value Vd shown in FIG.

On the other hand, if the slope inclination angle θs increases and a running state on a steep slope is detected while the above-described control operation is being performed, the comparison operation unit 18 sets the reference value to a reference value. The value of the regulation data decreases, and the telescopic drive of the working machine ascending / descending cylinder 9 is performed with the reference value defined by the decreased climb regulation data as the upper limit without resetting the climb regulation volume 13 set to the voltage value Vd. Is controlled. Therefore, as the tilting state of the field scene changes, the upper limit position of the work machine 3 is automatically changed, so that the danger of running on a steep slope while holding the work machine 3 at a carelessly high position is avoided. The stable running state of the agricultural tractor 1 can be maintained.

FIG. 8 shows a case in which the control content of the comparison operation section 18 in the CPU is changed in the control configuration shown in FIG. 7A, in which the control operation is performed. In the meantime, when the slope inclination angle θs increases and the value of the ascending regulation data serving as the reference value in the comparison operation unit 18 decreases, the voltage value Vd corresponding to the reference value is subtracted from the maximum voltage value Vmax. Then, the obtained difference voltage value is set as the dead voltage value Vf from the minimum voltage value Vmin (= 0 V). When the rising regulation volume 13 is operated in the direction of the maximum voltage value Vmax beyond the dead voltage value Vf, the dead voltage value Vf is linearly changed as a variable start value of the rising regulation volume 13 to lift the lift. Arm 5
The dead zone of the variable operation occurring up to the maximum set value of the upper limit height is wiped out, and the sense of incongruity at the time of operating the ascent control volume 13, that is, the "play" of the variable operation on the side where the upper limit height set value is higher is set. And smooth operation can be maintained.

FIG. 7B and FIG. 9 show that 1 to 4 bits
Multi-stage A / D converter 17 with different resolutions up to 2 bits
This shows a configuration in which the slope of the linear change of the ascending restriction volume 13 is changed via the data calculation unit 17 ′ having a to 17 d.

Here, for example, when the slope inclination angle θs increases during the control operation and the value of the ascent control data serving as the reference value in the comparison operation unit 18 decreases,
The voltage value Vd corresponding to the reference value is changed to Vmax corresponding to the maximum upper limit height, and the detection signal obtained by the body sensor 16 is sent from the inclination angle calculator 19 to the switching signal generator 24. A two-bit switching signal is generated, and one of the four enable signals switched and output from the multiplexer unit 25 by the input of the switching signal is converted into one of the A / D converters 17a to 17d of the data operation unit 17 '.
To the corresponding A / D
Only the converters 17a to 17d are operated independently, and the inclination of the linear change of the rising regulation volume 13 is changed by changing the resolution of the data calculation.

That is, when the agricultural tractor 1 travels in a field scene consisting of a flat land or an inclined surface close thereto,
Since the upper limit height of the lift arm 5 can be made large, the A / D converter 1 having a low resolution in the data calculation unit 17 ′ based on the rise restriction data value obtained by the inclination angle calculation unit 19.
7a is switched to the operating state, and the inclination of the linear change indicated by the dotted line in FIG.

When traveling on a steeply inclined field, the upper limit height of the lift arm 5 is limited to a low value. A / D converter 1 with high resolution in 17 '
7b is switched to the operating state, and the inclination of the linear change shown by the solid line in FIG.

The change of the straight line change in the data calculation unit 17 'is performed in a height width obtained by dividing the ascending restriction data value obtained in the inclination angle calculation unit 19 into four parts with respect to the height of the lift arm 5, and As the regulation data value is set lower, the A / D converter on the higher resolution side is switched.
Therefore, since the dead zone does not exist in the variable range of the rising regulation volume 13, the operation can be performed in the entire variable range, and the quick variable operation and the fine variable operation can be performed without the need for a cumbersome switching procedure. It can be performed appropriately according to.

FIGS. 10 and 11 show other examples of control contents obtained by expanding the control structure shown in FIGS. 8 and 9. In FIG. 10, while the control operation is being performed, For example, when the slope inclination angle θs increases and the value of the ascent control data serving as the reference value in the comparison operation unit 18 decreases,
For the maximum voltage value Vx corresponding to the maximum upper limit height of the lift arm 5 when traveling on a flat field scene, the linear change of the rising restriction volume 13 defined by this is determined by the control operation in FIG. Similarly, when the dead voltage value Vf is deviated to the higher side of the upper limit height set value as a variable start value of the rise restriction volume 13 and the rise restriction volume 13 is operated beyond the set value of the rise restriction data, Uses the height setting of the lift arm 5 up to its maximum height by changing the maximum voltage value Vx corresponding to the maximum upper limit height of the lift arm 5 to the maximum voltage value Vmax that can be changed by the lift control volume 13. It is possible to improve workability and operability.

Also, in FIG. 11, during the control operation, the slope inclination angle θs increases and the comparison operation unit 1
For example, when the value of the ascent control data serving as the reference value at 8 decreases, the voltage is changed to the voltage value Vd corresponding to the reference value to be the maximum voltage value Vx corresponding to the maximum upper limit height, and the ascent control is performed. Exceeding the set value of the data, the rising regulation volume 13
Is operated, the maximum voltage value Vx corresponding to the maximum upper limit height of the lift arm 5 is set to the rising regulation volume 13.
By changing to the maximum voltage value Vmax that can be varied by
The height setting of the lift arm 5 can be used up to its maximum height, so that workability and operability can be improved.

FIGS. 12 (a) and 12 (b) show a case where the central variable position of the resistance value is set to the maximum value of the lift arm height instead of the rising restriction volume 13 comprising a normal variable resistor, Control the rise by variable operation of
In addition, it shows a configuration of an ascending regulation volume 13 ′ in which an ascending regulation control with an inclination control is performed on the side of gradually increasing the resistance value. For example, the ascending regulation volume 13 ′ is changed from MIN to MAX on a normal ascending regulation control side. When the rotation is performed in the direction, the working machine lifting / lowering cylinder 9 that drives the lift arm 5 with the change in the variable resistance value according to the rotation position is driven irrespective of the tilting state of the field, and the resistance exceeds the MAX position. When rotating to the value increasing side, the slope inclination angle θs
, The inclination control of the upper limit height of the work implement 3 and the ascending restriction control linked thereto are simultaneously performed. Therefore, the two different types of control can be performed by the single ascending control volume 13 'without requiring a cumbersome switching operation, and the operational burden can be reduced, and the arrangement space of the operation panel 15 can be more effectively used. Can be used.

[0029]

In summary, the present invention relates to a working machine which is connected to a rear part of a tractor so as to be able to move up and down via a three-point link by a variable setting of a control device provided in a driving operation unit. In a lifting device for a working machine in a tractor configured to control an upper limit and a lower limit height of the working machine, a control unit for detecting a front, rear, left and right inclination state of the tractor body is provided, and a detection value obtained by the control unit is provided. Based on, since the upper limit height of the work machine was changed, even when the agricultural tractor travels on a steep slope while the work machine is positioned at the preset upper limit height,
The machine can be automatically lowered to the proper upper limit position at an appropriate ascending / descending speed with little shock without a sudden acceleration / deceleration operation, and the center of gravity of the tractor body can be maintained at a low level, and running stability can be maintained. Thus, a useful novel effect that a smooth field operation can be performed while ensuring the above is achieved.

[Brief description of the drawings]

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

FIG. 2 is a plan view showing an arrangement of an operation panel.

FIG. 3 is an explanatory diagram showing a method of calculating a slope inclination angle in an agricultural tractor that travels at an advancing direction angle θy with respect to the slope S.

FIG. 4 is a graph showing a relationship between ascending restriction data and a slope inclination angle θs.

FIGS. 5 (a) and (b) are graphs showing a variable relationship between ascending restriction data obtained at a slope inclination angle θs and an ascending restriction volume.

FIG. 6 is a flowchart of the ascent control;

FIG. 7 (a) is an elevation control volume, an airframe sensor and C
It is a block diagram which shows the connection with PU and the connection with the cylinder for work machine raising / lowering. (B) is a block diagram of another example showing an ascent control volume, a connection between a machine sensor and a CPU, and a connection with a work machine elevating cylinder.

FIGS. 8A and 8B are graphs showing variable relations between ascending restriction data obtained at the slope inclination angle θs and ascending restriction volumes.

FIGS. 9A and 9B are graphs showing a variable relationship between ascending restriction data obtained at a slope inclination angle θs and an ascending restriction volume.

FIGS. 10 (a) and (b) are graphs showing a variable relationship between ascending restriction data obtained at a slope inclination angle θs and an ascending restriction volume.

FIGS. 11 (a) and (b) are graphs showing a variable relationship between ascending restriction data obtained at a slope inclination angle θs and an ascending restriction volume.

FIG. 12 (a) is an enlarged plan view of a rising restriction volume. (B) is an operation explanatory view showing the connection between the ascent control volume, the CPU, and the working machine elevating cylinder.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Agricultural tractor 2 Three-point link 3 Work implement 13 Ascent control volume

Claims (7)

[Claims] An upper limit and a lower limit height of a working machine which is driven up and down by a variable setting of a control device provided in a driving operation unit with respect to a working machine connected to a rear portion of a tractor via a three-point link so as to be able to move up and down. A lifting and lowering device for a working machine in a tractor, the control device comprising: a control unit configured to detect a front, rear, left and right inclination state of the tractor body, and the working machine based on a detection value obtained by the control unit. A lifting device for a working machine in a tractor, wherein an ascending upper limit height is changed. 2. The control device according to claim 1, wherein the control device is provided with a variable lift control volume of the working machine, and the detected value obtained by the first control means is converted into a set upper limit height value of the raise control volume. The lifting / lowering device for a working machine in a tractor according to claim 1, wherein: 3. The variable start value of the rising restriction volume is deviated to the upper limit height setting value side, and the gradually increasing change of the rising restriction volume reaching the upper limit height setting value is linear. Item 3. The lifting device for a working machine in a tractor according to Item 1 or 2. 4. The method according to claim 1, wherein a slope of a linear gradual increase from the variable start value of the rising restriction volume to the upper limit height setting value is changed according to the setting change of the upper limit height setting value. The lifting / lowering device for a working machine in a tractor according to claim 1, 2 or 3. 5. A variable start value of the rising regulation volume is deviated to an upper limit height setting value side, a gradual change of the rising regulation volume reaching the upper limit height setting value is linear, and the upper limit height setting is performed. 4. The working machine according to claim 1, wherein the maximum value that can be set by the ascending control volume is changed again to the upper limit height when the value exceeds the value. lift device. 6. The slope of a linear gradual increase from the variable start value of the rising restriction volume to the upper limit height setting value is changed according to the setting change of the upper limit height setting value, and the upper limit height setting value is changed. The lifting and lowering of the working machine in the tractor according to claim 1, 23 or 4, wherein the maximum value that can be set by the ascending control volume is changed again to the upper limit height setting value when the value exceeds the limit. apparatus. 7. A single ascent control volume for setting an upper limit height of a work machine can be switched between a work machine ascend regulation control on a flat terrain and a work machine ascend regulation control on an inclined terrain. Claims 1, 2, 3, 4, 5
Or the lifting and lowering device of the working machine in the tractor according to 6. [0001]