JPH0581201B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention maintains a constant horizontal posture even when the towing machine tilts from side to side, so that the leveling effect is constant. This invention relates to a rolling control device that controls expansion and contraction of one lift rod of a link mechanism that connects ground-based work equipment.

[Prior Art and Problems to be Solved by the Invention] If the rolling control is continued even when the ground-based work equipment is raised during turning operations etc. during work near the headland, the ground-based work equipment will move from the towing machine. The universal joint shaft that transmits power to the towing machine was affected by both the horizontal and vertical inclinations of the ground work equipment relative to the towing machine, and the universal joint shaft broke significantly at its universal part. A large bend angle prevents the smooth rotation of the universal joint shaft, accelerating wear and tear on the parts, and also generates a large amount of noise.In order to avoid reducing efficiency, conventionally, when raised to a certain height, A known technique is to stop the rolling control and return the ground work machine to a reference posture parallel to the towing machine.

However, with this known method, when the ground work machine is raised while the towing machine is tilted left and right,
The lift rod suddenly makes a large expansion and contraction movement, and a large impact force due to this expansion and contraction acts on the ground work equipment and the traction machine.In addition, the ground work equipment also tilts significantly in the same direction as the traction machine, so the impact force is reduced. Both the slope and the tilt compete with each other, resulting in a lack of stability in the lateral direction.Also, when returning to the working position from this state, the lift cylinder suddenly returns to the controlled state and operates, resulting in a large impact force. There is a problem that occurs.

[Means for Solving the Problems] The present invention aims to prevent the above-mentioned decrease in stability, and has taken the following technical measures. That is, the working machine 2 is connected to the traction machine 1 via the hydraulic lifting mechanism 11 so as to be able to rise and fall freely, and the traction machine 1
is equipped with a left/right tilt sensor S ₁ that detects left/right tilt.
is further provided with a sensor _S3 for reading the rotation angle of the lift arm 3, and an attitude changing means 13 located between the towing machine 1 and the working machine 2 and changing the relative angle of both. is interposed, and
A sensor _S2 for reading this relative angle is provided beside the attitude changing means 13, and the left and right tilt sensor
In the rolling control device, the lift arm 3 is moved up and down based on the detection results of the sensor S ₁ and the sensor S ₂ . The present invention is characterized in that a control means 33 is provided for limiting the attitude control amount of the working machine 2 with respect to the towing machine 1 when the sensor _S3 detects that the work machine 2 has reached a predetermined height near the upper limit position. The configuration is a rolling control device.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

As shown in FIG. 1, a rotary tilling device as an example of a ground working device 2 is attached to the rear of a tractor as a towing machine 1, and is moved up and down to a pair of left and right lift arms 3, 3 via left and right lift rods 4, 5. They are connected by a three-point linkage mechanism 9 consisting of swinging left and right lower rings 6, 7 and a central top link 8, and this three-point linkage mechanism 9 uses its lift arms 3, 3 and hydraulic pressure. It is lifted and lowered by a hydraulic lifting mechanism 11 that is raised and lowered by a lift cylinder 10, and the horizontal inclination angle θ of the ground work equipment 2 accompanying the left-right tilting of the towing machine 1 is controlled by the towing machine 1. By extending or shortening one of the lift rods 5 using the lift rod cylinder ₁₂ , the left and right attitude of the ground work equipment 2 can be changed to a horizontal attitude, for example, by detecting the horizontal inclination sensor S1 installed on the ground. An automatically corrective rolling control mechanism 13 is provided, and the length of the lift rod 5 is detected by a lift rod sensor _S2 consisting of, for example, a linear sliding potentiometer.

The illustrated hydraulic elevating mechanism 11 is operated based on an instruction value α instructed by, for example, a rotational operation of a potentiometer lever serving as an elevation instruction member 14, and the height corresponding to this instruction value α is The lift arms 3, 3 are configured so as to reach the.

An arm 17 is fixed to a position shaft 16 that is pivotally supported on the cylinder case 15. A position link 21 is connected to the position link 21 whose lower part is connected to a spool 19 of a control valve 18 that controls the supply and discharge of pressure oil with a pin 20. Suspended with Hepin 22,
Lift arm shaft 23 integrated with lift arms 3, 3
Arm 24 and position link 21 fixed to
, pins 25, 26 and feedback link 27
It is connected to a position link mechanism 28 and is rotated to a predetermined position by a lift instruction member 14 fixed to a position shaft 16. For example, when in a lifting position, The spool 19 is stationary at the neutral position shown in FIG. 3, and when the elevation instruction member 14 is rotated counterclockwise in FIG. 3, the position shaft 16 is rotated counterclockwise in FIG. Link 21 is pin 25
The spool 19 rotates counterclockwise using the fulcrum as a fulcrum, and the spool 19 moves to the right, whereby the pressure oil in the lift cylinder 10 is discharged into the tank and the lift arm 3,
3 begins to rotate downward, and as it does so, the arm 24 also moves downward and the feedback link 27 begins to move to the left in FIG. 3, and the position link 21 rotates clockwise around the pin 22. Rotate and return the spool 19 to the left, and when the lift arms 3, 3 reach a predetermined height, the spool 19
3 returns to the neutral position shown in FIG. 3, so that the ejection operation from the lift cylinder 10 is stopped.

In order to detect the height of the three-point linkage mechanism 9, a detection shaft of, for example, a rotary potentiometer is connected to the pivot base of the lift arm 3 to provide a lift value sensor _S3.
The left and right tilt angle θ detected by the left and right tilt sensor _S1 is
As shown in FIG. 5, the control circuit controls the expansion and contraction of the lift rod cylinder 12 based _on Based on this, the bias value calculation circuit 30 corrects the bias value to be controlled, and calculates the bias voltage V corresponding to this bias value and the rod corresponding to the length l of the lift rod 5 by the lift rod sensor _S2 . In order to limit the voltage Vl, the lift voltage Vα corresponding to the detected lift value α of the lift arm 3 by the lift value sensor S ₃ , and the left-right tilt difference of the ground work equipment 2 with respect to the traction machine 1 to within a certain value, this left-right tilt is The expansion/contraction voltage ( _{Vl 0 + Δl} ) or ( _{Vl 0} −Δl) and a set lift voltage Vα ₀ , which is the output of the lift value setter 32 that specifies the set lift value α ₀ , which is a sufficient operating height for turning operation, for example, are input to the multiplexer 34 of the microcomputer 33. However, it is converted into a digital value by the A/D converter 35, and in the correction amount calculator 36, when the lift voltage Vα is lower than the set lift voltage Vα ₀ and the bias voltage is V, the reduction drive is performed. circuit 3
7, the lift rod 5 is contracted by the switching operation of the electromagnetic switching valve 38 so that the bias voltage V becomes 0, and when the bias voltage V is negative, the extension drive circuit 39 is operated to extend the lift rod 5 by the electromagnetic switching valve 38 to control the bias voltage V to 0. When the lift voltage Vα is higher than the set lift voltage Vα ₀ , the above drive is performed. The operation of the circuits 37 and 39 is determined when the maximum value of the rod voltage Vl is the expansion/contraction voltage (Vl ₀ +Δl) or (Vl ₀
−Δl).

[Operation of the invention] In other words, in either the state where the ground work equipment 2 is being lowered or the state where the ground work equipment 2 is operated to the set lift value α ₀ to obtain the operating height necessary for turning operation. However, basically, the correction computer 36 issues a command to control the ground work equipment 2 to the reference posture, but the set lift value α ₀ near the upper limit position
Only when the lift rod 5 is operated, a restriction is placed so that the lift rod 5 is not extended or contracted beyond the maximum or minimum length, and thereby the horizontal inclination angle of the ground work equipment 2 with respect to the traction machine 1 is The correction amount calculator 36 works so that the amount is within a certain value.

[Effects of the Invention] Since the present invention is configured as described above, it has the following technical effects.

That is, a working machine 2 is connected to the traction machine 1 via a hydraulic lifting mechanism 11 so as to be able to rise and fall freely, and the traction machine 1 is equipped with a lateral inclination sensor S ₁ that detects inclination in the lateral direction, and is further equipped with a lift arm 3. A sensor _S3 is provided to read the rotation angle of the towing machine 1 and the working machine 2, and an attitude changing means 13 is interposed between the towing machine 1 and the working machine 2 to change the relative angle of the two. A sensor S ₂ for reading the target angle is provided beside the posture changing means 13, and the horizontal tilt posture of the working machine 2 is maintained at the set posture based on the detection results of the horizontal tilt sensor S ₁ and the sensor S ₂ . In the rolling control device in which the posture changing means 13 is controlled to expand and contract, when the sensor S ₃ detects that the lift arm 3 has risen and reached a predetermined height near the upper limit position, Work equipment 2
Since the control means 33 is provided to limit the attitude control amount of the lift rod 5, even if the ground work machine 2 is raised for turning operation when the towing machine 1 is tilted significantly to the left or right, the lift rod 5 does not move. Since the amount of expansion or contraction is limited and does not exceed a certain value, the expansion and contraction movement of the lift rod 5 will not become excessive.
Therefore, the bending angle of the universal portion of the universal joint shaft does not become large, and there is no risk of damage to the universal joint shaft or generation of abnormal noise.

In addition, in this invention, the tilt attitude control amount of the working machine is limited only when the lift arm 3 rises and reaches a predetermined height near the upper limit position, so that work can be performed smoothly even in soft places. can be done. That is, in places where the ground is soft, both the towing machine 1 and the work machine sink, and the work machine is pushed up by the reaction force from the ground and tries to rotate the lift arm 3 upward. case,
When the work machine is on the ground, the left and right attitude control amount is not limited, so the work machine can always be maintained at a predetermined angle. In addition, since the left/right tilt sensor S ₁ is installed on the towing machine 1 side rather than on the work machine side, the left/right attitude can be controlled in the same way even if another work machine is connected in place of the currently connected work machine. In this way, it is possible to control the left and right posture of various operations with one traction machine 1, which is economical and expands the adaptability of operations.

[Brief explanation of drawings]

The figures show an embodiment of the present invention, in which Fig. 1 is an overall side view, Fig. 2 is a perspective view of essential parts, Fig. 3 is a longitudinal sectional side view of the position link mechanism, Fig. 4 is a rear view, and Fig. 4 is a rear view. FIG. 5 is a block diagram of the control device. Explanation of symbols, 1... Traction machine, 2... Ground work equipment, 5... Lift rod, 9... Three-point linkage mechanism, 11... Hydraulic lifting mechanism, 14... Lifting instruction member, S ₁ ... Left/right tilting Sensor, S ₃ ...Lift value sensor.

Claims (1)

[Claims] 1 A working machine 2 is connected to the traction machine 1 via a hydraulic lifting mechanism 11 so as to be able to rise and fall freely, and the traction machine 1 is equipped with a lateral inclination sensor S ₁ that detects inclination in the left and right direction, A sensor _S3 for reading the rotation angle is provided, and an attitude changing means 13 is interposed between the towing machine 1 and the working machine 2 for changing the relative angle of both. The sensor S ₂ that reads the angle is the attitude changing means 1
3, and controls the expansion and contraction of the posture changing means 13 so as to maintain the horizontal tilted posture of the working machine 2 at the set posture based on the detection results of the horizontal tilt sensor _S1 and sensor _S2 . In the control device, the sensor detects that the lift arm 3 has risen to a predetermined height near the upper limit position.
A rolling control device characterized in that a control means 33 is provided that limits the attitude control amount of the working machine 2 with respect to the traction machine 1 when S ₃ is detected.