JP2000316314A - Tillage depth controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the following capability of a working machine to a ground by preventing overdoing and response retardation of the working machine caused by the pitching of a machine body when controlling the tillage depth of the working machine by detecting upper or lower turning angle of a rear cover of the working machine. SOLUTION: A rear cover sensor 28 for detecting upper or lower turning angle of a rear cover 2 attached to a rotary working machine 12 is installed, and the rotary working machine 12 is lifted or lowered by turning a lift arm 22 upper or lower so that the detected value of the rear cover sensor 28 may coincide with the target value of the tillage depth set by a tillage depth- regulating dial 16. A pitching angular velocity sensor 42 is installed in the upper surface of a transmission case 18 to detect the pitching angular velocity of the machine body, and the tillage depth control of the rotary working machine 12 is carried out based on the detected value of the rear cover sensor 28 and the detected value of the pitching angular velocity sensor 42.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tillage depth control device, and more particularly to a tillage depth control device such as an agricultural tractor or a riding management machine.

[0002]

2. Description of the Related Art In an agricultural work vehicle such as an agricultural tractor or a riding management machine, a work machine such as a rotary is connected to a rear portion of an airframe, and a rear cover mounted on the work machine is vertically moved. A lift arm is provided to detect the amount of plowing of the work implement by providing a rear cover sensor for detecting the rotation angle, and to maintain the rotation angle of the rear cover according to the target plowing depth set by the plowing depth setting means. There is known a device provided with a tillage depth control device for vertically moving a work machine to move up and down. However, when the body is pitched back and forth during the work, the turning angle of the rear cover changes abruptly, so that the work machine may go up and down more than necessary.

Further, in the above-described tillage depth control device, dead zones are provided above and below the target tillage depth value, and within this dead zone, even if the rotation angle of the rear cover slightly changes, the lifting and lowering of the working machine is suppressed. For this reason, when the body is pitched, the lifting and lowering of the work machine is delayed, and the ability to follow the ground is deteriorated.

Therefore, when the vertical rotation angle of the rear cover of the work machine is detected to control the working depth of the work machine, excessive movement of the work machine and delay in response due to pitching of the machine body are prevented, and the ability to follow the ground is improved. A technical problem to be solved arises for improvement, and an object of the present invention is to solve this problem.

[0005]

SUMMARY OF THE INVENTION The present invention has been proposed in order to achieve the above object. A work machine is connected to a rear portion of an airframe, and a vertical rotation angle of a rear cover attached to the work machine is determined. Plowing depth control, in which a lift arm is turned up and down to raise and lower the work machine in order to maintain the turning angle of the rear cover according to the plowing depth target value set by the plowing depth setting means by providing a rear cover sensor to detect In the device, means for detecting the angular velocity when the aircraft pitches, provided based on the detection value of the rear cover sensor and the detection value of the pitching angular velocity,
A tillage depth control device configured to raise and lower the work machine, and a rear cover sensor for connecting the work machine to a rear portion of the body and detecting a vertical rotation angle of a rear cover mounted on the work machine is provided. When the airframe pitches in a tillage depth control device that raises and lowers the work machine by rotating the lift arm up and down in order to maintain the turning angle of the rear cover according to the tillage depth target value set by the setting means. The means for detecting the angular velocity of the, provided a dead zone of a predetermined width above and below the plowing depth target value to check the lifting and lowering of the working machine, even if the rotation angle of the rear cover is within the dead zone, When the pitching angular velocity detecting means is detecting the angular velocity in the forward or downward rising direction, the work machine is lowered, and the pitching angular velocity detecting means detects the angular velocity in the forward or downward descending direction. Rutoki is to provide a tilling depth control device configured to raise the working machine.

[0006]

An embodiment of the present invention will be described below in detail with reference to the drawings. FIGS. 1 and 2 show a small tractor 10 as an example of a work vehicle, and a rotary work machine 12 is connected to a rear part of the body via a link mechanism 11.
In the vicinity of the driver's seat 13, a position lever 15, which is a means for setting the vertical position of the work implement, a cultivation depth adjusting dial 16, which is a means for setting the amount of cultivation of the work implement, and a tilt, which is a means for adjusting the inclination of the work implement in the horizontal direction with respect to the vehicle body. An adjustment dial 17 and the like are provided. On the upper surface of the transmission case 18, an inclination sensor 41 for detecting the rolling angle of the fuselage and a means for detecting the angular velocity when the fuselage is pitching are provided at a substantially central portion of the upper position near the rear axle 19. A pitching angular velocity sensor 42 and a rolling angular velocity sensor 4 which is means for detecting an angular velocity when the aircraft rolls.
3 are integrally accommodated in the case 44.

The link mechanism 11 comprises a top link 20 and left and right lower links 21 and 21. The distal ends of the left and right lift arms 22 and 22 are connected to the lower links 21 and 21 by lift rods 23 and a lift cylinder 24. When the lift arm 22 is rotated by the drive of, the lower links 21 and 21 move up and down via the lift rods 23 and 23. In this way, the rotary working machine 12 moves up and down around the distal ends of the lower links 21 and 21.

[0008] A lift arm angle sensor 25 is provided at the rotation base of the lift arm 22 as means for detecting the elevation position of the work machine. The lift arm angle sensor 25 detects the rotation angle of the lift arm 22. Then, the controller 50 calculates the elevation of the rotary working machine 12. A rear cover 27 is attached to the rear end of the main cover 26 of the rotary work machine 12 so as to be vertically rotatable. A rotation angle of the rear cover 27 is detected by a rear cover sensor 28, and the controller 50 controls the rotation of the rotary work machine 12. Calculate the tillage depth.

On the other hand, as an actuator for changing the inclination of the rotary working machine 12 in the left-right direction, a rolling cylinder 30
Is provided so that the inclination of the rotary working machine 12 with respect to the machine body in the left-right direction can be changed by extending and contracting the rolling cylinder 30 to change the lift amount of the lower link 21 in the left and right directions.

A stroke sensor 31 is provided adjacent to the rolling cylinder 30. The stroke sensor 31 detects the length of expansion and contraction of the rerolling cylinder 30, and the controller 50 determines the rolling angle of the rotary working machine 12 with respect to the machine body. And the rolling cylinder 30 according to the set value of the tilt adjustment dial 17.
To drive the rotary work machine 12 to perform horizontal control.

A steering handle 32 is provided in front of the driver's seat 13 as a steering operation part of the fuselage. A forward / backward switching lever 33 is provided near the steering handle 32, and the forward / backward switching lever 33 is provided. Is operated, the driving force transmitted to the rear wheels 34 is reversed, so that the traveling direction of the aircraft can be selected. Further, a shift lever 35 is provided at a lower front portion of the driver's seat 13, and left and right brake pedals 36, 36 which can be depressed independently of each other are provided. The rotation operation of the steering handle 32 is transmitted to the steering device 37, and the front wheel 38 turns in accordance with the steering amount. The steering amount of the front wheel 38 is detected by a front wheel turning angle sensor 39.

FIG. 3 is a block diagram of a control system. The target value of the rotary working machine 12 is set by the working depth adjustment dial 16, and the vertical position of the rotary working machine 12 is detected by the detection signal of the lift arm angle sensor 25. , And the rotation angle of the rear cover 27 is detected by the rear cover sensor 28 to calculate the plowing depth of the rotary work machine. Then, in order to maintain the rotation angle of the rear cover 27 at a predetermined angle corresponding to the target plowing depth set by the plowing depth adjustment dial 16, the rising solenoid or the descending solenoid of the electromagnetic control valve that drives the lift cylinder 24 is moved to The controller 50 outputs a control signal. Accordingly, the lift arm 22 is rotated up and down, the rotary work machine 12 is raised and lowered, and the rear cover 27 is rotated so that the detection value of the rear cover sensor 28 is controlled to match the tillage depth target value.

On the other hand, the operator can arbitrarily set the inclination of the rotary working machine 12 in the left-right direction by using the inclination adjustment dial 17. The rolling angle of the aircraft with respect to the ground is detected by the inclination sensor 41, and the rotary work machine 12 with respect to the aircraft is
Is detected by the stroke sensor 31. The pitching angular velocity sensor 42 and the rolling angular velocity sensor 43 each use a vibrating gyro system, and have a simple structure, precision, and low cost. However, a sensor of another system other than the vibration gyro system may be used.

The equal inclination sensor 41, pitching angular velocity sensor 42, and rolling angular velocity sensor 43 are connected to the rear axle 19
Is provided at a substantially central portion in an upper position in the vicinity of the front wheel 38.
As compared with the case of installing on the side, it becomes closer to the center of gravity of the machine body, the vibration in the vertical direction is small, it is hard to receive disturbance and the measurement accuracy is improved. In addition, all three sensors are in case 4
Since it is housed integrally in the housing 4, the installation space is compact, and the power supply circuit can be shared.

Further, a horizontal mode switch, a vehicle body parallel mode, and an angle setting mode can be selected by a horizontal changeover switch 45, and the horizontal changeover is performed while detecting the relative inclination of the machine body and the work machine and the inclination with respect to the ground. The target value of the horizontal control is determined according to the mode set by the switch 45, and the rolling cylinder 30 is driven to drive the rotary working machine 12
Adjust the tilt of.

For example, when the horizontal switch 45 is set to the horizontal mode, the rotary work machine 1 is determined based on the detected value of the inclination sensor 41 and the detected value of the stroke sensor 31.
2 is calculated with respect to the ground, and a target value of the horizontal control is determined so as to make this tilt zero. Then, a control signal is output from the controller 50 to the right-up solenoid or the right-down solenoid of the electromagnetic control valve that drives the rolling cylinder 30 so that the measured value of the stroke sensor 31 matches this target value. Therefore, regardless of the attitude of the machine body, control is performed such that the tilt of the rotary work machine 12 in the left-right direction is horizontal.

On the other hand, when the horizontal switch 45 is set to the vehicle parallel mode, the left and right lower links 21 are set.
The target value of the horizontal control is determined so that the lift amounts of the two are equal. Then, in order to drive the rolling cylinder 30 so that the measured value of the stroke sensor 31 matches this target value, a control signal is output from the controller 50 to the above-mentioned right-up solenoid or down-right solenoid. Therefore, control is performed so that the inclination of the rotary working machine 12 in the left-right direction is parallel to the inclination of the body.

When the horizontal changeover switch 45 is set to the angle setting mode, a target value of the horizontal control is determined according to the set value of the tilt adjustment dial 17 arbitrarily set by the operator, and the measurement of the stroke sensor 31 is performed. In order to drive the rolling cylinder 30 so that the value coincides with the target value, a control signal is output from the controller 50 to the above-mentioned right-up solenoid or the down-right solenoid. Therefore,
Control is performed such that the inclination becomes an arbitrary inclination set by the rotary work machine 12.

As shown in the flowcharts of FIGS. 4 and 5, when the tillage depth control is started, first, the states of various sensors, switches, dials, and the like are read into the controller 50 (Step 100). The setting routine (Step 110) is executed.

In the angular velocity sensor of the vibrating gyroscope system, the reference voltage is liable to drift due to a temperature change. Therefore, a voltage which is regarded as having no angular velocity, that is, a reference value may vary depending on environmental conditions. Although there is a method of guaranteeing the temperature for the angular velocity sensor, it is necessary to combine a temperature sensor separately, which increases the cost. Therefore, the detection value of the angular velocity sensor is sampled at regular time intervals, and data whose variation in the detected value is within the prescribed value is moving averaged to obtain a reference value.

As shown in FIG. 6, when the specified time has elapsed (Step 111) and the detected value of the angular velocity sensor is within the specified value (Step 112), the detected value measured this time is used as the current data (Step 111). Step113). On the other hand, if the detected value of the angular velocity sensor deviates from the specified value when the specified time has elapsed, the data added last time is used as the current data without using the detected value measured this time (Step 114). And
Clear the oldest data of the angular velocity sensor and recalculate the moving average of the inclination of the aircraft to which this data was added (Step 11)
5) The result of this calculation is stored as a reference value with no change in angular velocity (Step 116).

As shown in FIGS. 4 and 5, after completion of the angular velocity sensor reference value setting routine (Step 110), the detection signal of the angular velocity sensor is monitored (Step 120). In the case of the plowing depth control, only the angular velocity when the aircraft is pitching is monitored, and when the pitching angular velocity sensor 42 detects the angular velocity of the forward or downward movement of the aircraft, the rotary work machine 12 is in a raised state. , The work equipment must be lowered. Accordingly, the lowering speed dnoutn of the working machine is set according to this angular speed (Step 12).
1). On the other hand, when the pitching angular velocity sensor 42 detects the angular velocity of the machine body rising or falling backward, the rotary working machine 12 is in a hanging state, and the working machine must be raised. Therefore, the lifting speed upoutn of the work implement is set according to the angular velocity (Step 122).

By setting the lowering speed dnoutn and raising speed upoutn of the working machine faster as the angular velocity of the pitching is higher, and performing the lifting / lowering operation substantially synchronized with the pitching occurring in the machine body, the lifting / lowering of the working machine is performed. Is controlled so that no response delay or overshoot occurs.

After the speed setting is completed in Step 121 or Step 122, or when the pitching angular velocity is not generated in the machine body, the target value set by the tillage depth adjustment dial and the detection value of the rear cover sensor 28 are used. Compare (Step
130). If the difference is within the dead zone of tillage control,
It is determined whether or not the down speed dnoutn according to the angular velocity is set (Step 140), and it is determined whether or not the up speed upoutn according to the angular velocity is set (Step 150). If not, turn off the lifting output for the work equipment (Step 16
0).

In Step 130, when the detected value of the rear cover sensor 28 is out of the demand for lowering the plowing depth target value, the process proceeds to Step 170, and the lowering speed rdnn of the working machine is set according to the deviation.
And proceed to Step220. On the other hand, in Step 130, when the detected value of the rear cover sensor 28 is out of the demand for raising the depth with respect to the target plowing depth, the process proceeds to Step 180, the raising speed of the working machine is set according to the deviation, and the process proceeds to Step 250. .

As shown in FIG. 7, a dead zone upper limit (+ B) is provided above and centered on the target plowing value (A), and a dead zone lower limit (-B) is provided below. Even if the detected value of 28 deviates from the tillage target value (A), if it is within the dead zone, the lifting output of the working machine is suppressed. According to the present invention, the upper limit (+) of the angular velocity sensor is set below the dead zone upper limit (+ B).
C) is set, and a lower limit (-C) for lowering the angular velocity sensor is set above the dead zone lower limit (-B).

Even if the difference between the target value of the tillage depth and the value detected by the rear cover sensor 28 in Step 130 is within the dead zone, for example, the body is pitched forward or downward and the angular velocity of the pitching is increased. If the lowering speed dnoutn according to is set, Step 140 to Step 200
And the detected value of the rear cover sensor 28 is above the lowering lower limit (-C) of the angular velocity sensor (Step C).
200) And if the pitching angular velocity in the forward-downward or backward-upward direction has not decreased, Step 210 to Step 220
Then, a lowering output to the working machine is executed at the higher operating speed of the lowering speed rdnn of the working machine according to the deviation or the lowering speed dnoutn of the angular speed according to the angular velocity (Step 220).

In step 130, the difference between the target value of the tillage depth and the value detected by the rear cover sensor 28 is within the dead zone, and the body is pitched forward or backward, depending on the angular velocity of the pitching. When the raising speed upoutn is set, the process proceeds from Step 150 to Step 230, in which the detection value of the rear cover sensor 28 is below the lower limit (+ C) required for raising the angular velocity sensor (Step 230), and is raised or lowered forward. If the pitching angular velocity in the direction has not decreased, the process proceeds to Step 250, and the raising output to the working machine is executed at the higher operating speed of the raising speed rupn of the working machine according to the deviation or the raising speed upoutn according to the angular speed, whichever is higher. (Step 250).

That is, even when the detection value of the rear cover sensor 28 is within the dead zone, when the pitching angular velocity is detected, the detection value of the pitching angular velocity sensor 42 has priority over the detection value of the rear cover sensor 28,
By allowing the working machine to move up and down within a predetermined limit, the response speed when the body is pitched is improved, and the followability of the rotary working machine 12 to the ground is improved.
However, when the pitching angular velocity in the forward decreasing or backward increasing direction is changing in the decreasing direction in Step 210, or when the pitching angular velocity in the forward increasing or decreasing direction is changing in the decreasing direction in Step 240, respectively. St
Proceed to ep160 to turn off the lifting output for the work equipment. Thus, even if there is a response delay in the hydraulic system including the lift cylinder 24, the lifting output is stopped early so that the working machine does not go too far.

The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified ones.

[0031]

As described in detail in the above embodiment, the invention described in the first aspect of the present invention raises and lowers the working machine based on the detected value of the rear cover sensor and the detected value of the pitching angular velocity of the machine. , The lifting and lowering of the work implement when the body is pitched can be prevented from delaying, and the followability of the work implement to the ground can be improved.

According to a second aspect of the present invention, even when the detected value of the rear cover sensor is within the dead zone, if the body is pitched, the detected value of the pitching angular velocity is prioritized, and the detected value is determined according to the pitching direction. Since the work machine is controlled so as to elevate and lower, it is possible to eliminate a response delay in elevating and lowering the work machine, and to prevent the work machine from going too far.

[Brief description of the drawings]

 The figure shows an embodiment of the present invention.

FIG. 1 is a side view of a body of a tractor and a rotary working machine.

FIG. 2 is a rear view of FIG. 1 from which illustration of a rear cover sensor and the like is omitted.

FIG. 3 is a block diagram of a control system.

FIG. 4 is a flowchart showing a control procedure of the tillage depth control device, part 1;

FIG. 5 is a flowchart showing a control procedure of the tillage depth control device, part 2;

FIG. 6 is a flowchart showing an angular velocity sensor reference value setting routine.

FIG. 7 is an explanatory diagram showing a dead zone of plowing depth control by a rear cover sensor and a limit of control by an angular velocity sensor.

[Explanation of symbols]

 Reference Signs List 10 Tractor 12 Rotary work machine 16 Cultivation depth adjustment dial 22 Lift arm 27 Rear cover 28 Rear cover sensor 42 Pitching angular velocity sensor 50 Controller

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[Procedure amendment]

[Submission Date] May 13, 1999 (1999.5.1
3)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Figure 3

[Correction method] Change

[Correction contents]

FIG. 3

Claims (2)

[Claims] A working machine connected to a rear portion of the machine body, a rear cover sensor for detecting a vertical rotation angle of a rear cover mounted on the working machine is provided, and a cultivation depth target value set by cultivation depth setting means; In order to maintain the rotation angle of the rear cover in accordance with the above, in the tillage depth control device for raising and lowering the work machine by rotating the lift arm up and down, a means for detecting an angular velocity when the body is pitched is provided, A tillage depth control device configured to raise and lower the work implement based on a detection value of a sensor and a detection value of a pitching angular velocity. 2. A working machine is connected to a rear part of the machine body, a rear cover sensor for detecting a vertical rotation angle of a rear cover mounted on the working machine is provided, and a target cultivation depth set by cultivation depth setting means. In order to maintain the rotation angle of the rear cover in accordance with the above, in the plowing depth control device for vertically raising and lowering the work machine by rotating the lift arm up and down, a means for detecting an angular velocity when the body is pitched is provided. A dead zone of a predetermined width is provided above and below the depth target value to restrain the lifting and lowering of the work machine, and even when the turning angle of the rear cover is within the dead zone, the pitching angular velocity detecting means is lowered or raised forward. When detecting the angular velocity in the direction, lower the work machine,
The plowing depth control device is characterized in that the work implement is raised when the pitching angular velocity detecting means detects an angular velocity in a forward upward or backward downward direction.