JPS6344322B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a work machine lifting device for a power agricultural machine that can automatically adjust the height of the work machine relative to the ground to be constant while the machine is in operation.

Agricultural machinery that operates while traveling in a field often undergoes various operations by an operator due to the nature of the field. Therefore, it is desirable that the operation of agricultural machinery be as simple as possible. Regarding the height setting of work equipment, which is frequently used in various operations, there are two methods: electrical control and mechanical control, but electrical control is expensive, and mechanical control is expensive. Although various studies have been made in the past, the operations have been complicated.

In other words, for those that perform mechanical control, for example, when switching the work equipment from position control to depth control, or when adjusting the working position of the work equipment on the ground using depth control, the link between position control and depth control is The worker must first cut off the switch and switch so that only one side is effective, or the worker must stop work and operate a switching device or adjustment device located near the work machine, and this operation requires skill. .

The operations required to control the height of the work equipment are frequently performed in this way, so automating and simplifying this process will greatly reduce the operational burden on the operator, while also ensuring uniform work accuracy by maintaining the work equipment at a constant height. is measured.

Therefore, the present invention makes it possible to arbitrarily change the position of the work machine relative to the ground surface without disconnecting the position control and depth control even if the depth signal is constantly fed back over the entire feedback operation range of the position signal. This was done as a result of research.

An important point of the present invention is that a control device such as a switching valve that controls a work machine lifting device receives a work machine height signal;
Both the work equipment position signal and the work equipment height detection signal can be constantly fed back over the entire range of feedback operation, and the ground surface is sensed by being linked to a depth control device installed opposite to the feedback path. A link mechanism that responds to a sensor that operates when the work equipment is activated, and a feedback link mechanism that is linked to the position control device to detect the work equipment height when the work equipment position detection signal instructs the work equipment to raise and stop The signal is automatically disconnected to give priority to the feedback path of the work equipment position signal, and the set engagement position of the feedback path and the link mechanism provided opposite thereto is determined based on the feedback path of the work equipment height detection signal. The set engagement position is configured to be constant over the entire operating range, and is configured to be movable so as to change the operation start position of the depth control device.

Next, one embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, a rotary tiller 2, which is a working machine, is pivotally mounted to the rear end of a tractor 1 so as to be movable up and down. In this embodiment, a case of an agricultural tractor will be explained with the rotary tiller 2 as the working machine. In addition to the rotary tiller 2, the working machine may be a traveling machine such as a plowing rotor, a reaping machine, a rice transplanter, etc. This includes all power-powered agricultural machinery that is attached to the vehicle and raised and lowered. The rotary plowing section 2 has a support frame 3 which is moved up and down by a hydraulic device such as a hydraulic cylinder and various control valves provided on the body 4 of the tractor 1 via a position control device 5 and a lift arm 6 and a lift rod 7 of a hydraulic lifting device. are connected. On the other hand, a depth control device 8 is provided extending from the vicinity of the position control device 5 to the rear end of the rotary tilling section 2 to control the height of the working machine relative to the ground surface.

The configurations of the position control device 5 and the depth control device 8 arranged in this way will be explained for each device below.

(a) Position control device (hydraulic lifting device) As shown in FIG.
0, a disc spring 11 that provides resistance to prevent them from inadvertently rotating, an arm 12 fixed to the lever support shaft 10, and a lever connecting this arm 12 and an arm 14 fixed to the lever interlocking shaft 13. The link 15, the valve shifter link 16 fixed to the lever interlocking shaft 13, and the spool 19 of the switching valve 18 fixed to the hydraulic case 17 linked thereto.
The valve link 20 is rotatably connected to the valve link 20.

On the other hand, the feedback mechanism 5b, as shown in FIG. A feedback shifter arm 25 is engaged by a spring 24 to a stopper 23 provided at an intermediate portion thereof, and its base end is pivotally supported by the hydraulic case 17, and its fulcrum shaft interlocks with this feedback shifter arm 25. A feedback shifter shaft 26 and an arm pin 2 whose upper end is fixed to the feedback shifter shaft 26 and whose lower end engages with the lower part of the valve link 20.
It consists of 7.

The position control device 5 configured in this way operates the valve link 20 via each link when the position lever 9 is rotated in the direction of arrow A in FIG.
rotates about the arm pin 27 in the direction of arrow E, moves the spool 19 in the direction C, and brings the switching valve 18 to the raised position. And the lift arm 6 is shown in Fig. 2G.
As the valve shifter link 20 rotates in the direction shown in FIG. Return 18 to the neutral position.

Furthermore, when the position lever 9 is rotated in the direction B in FIG. 3, the valve link 20 is rotated in the F direction due to the opposite effect to that described above, moving the spool 19 in the D direction and lowering the switching valve 18. position. When the lift arm 6 rotates in the direction I in FIG. 2, the valve link 20 rotates in the direction of arrow K to return the spool 19 in the direction C in FIG. 3 and return the switching valve 18 to the neutral position.

The height of the rotary tiller 2 relative to the machine body 4 is determined by such an action.

(b) Depth control device As shown in Figures 2, 6, and 10, the base end of a depth lever 28 is rotatably pivoted to the outer end of the lever support shaft 10 on the left side of the machine body. has been done.
The upper part of this lever 28 operates in the groove 30 of the lever guide 29 together with the position lever 9. In addition, the depth lever 28 and the lever guide 2
A spring 32 is installed between the lever 28 and the vertical piece 31 of 9 to prevent the lever 28 from rotating inadvertently.
is located. One end of the L-shaped pin 33 shown in FIGS. 10, 7, and 2 is fixed to the base end of the depth lever 28 so that it is positioned horizontally, and the other end is attached to the left side of the fuselage 4. It is placed so that it sticks out.

On the other hand, to explain the link mechanism 34 that interlocks with the sensor section 53, which will be described later, the middle section of the sensor response link 35 is pivotally attached to the rear left side surface of the hydraulic case 17 by a pin 36, and the tip thereof A rear end portion of a push link 37 is pivotally supported by a pin 38 in the section. An elongated hole 39 is bored in the front end of this push link 37, and this elongated hole 39 is connected to the lever support shaft 1.
0, the push link 37 is swingably supported in the longitudinal direction of the fuselage 4.

On the outer surface of the front side of the push link 37, there is a pin 4 near the bent part of the square-shaped contact link 40.
1, and an elongated hole 42a with an open front end is formed at the end of the horizontal portion 42 thereof. The other end of the L-shaped pin 33 of the depth lever 28 is engaged with this elongated hole 42a. Therefore, by swinging the depth lever 28 back and forth, the contact link 40 pivots in the vertical direction about the pin 41 as a fulcrum.

On the other hand, to explain the link mechanism 43 interlocked with the position control device 5, which is the above-mentioned hydraulic lifting device, as shown in FIG. The lower end portion is pivotally supported by a pin 45 so as to be swingable in the front-rear direction. And this switching link 4
A pin 46 provided at the upper end of the contact link 40 is arranged at a position where it contacts and separates from the hanging portion 47 of the contact link 40. Further, above the pin 45, which is the pivot point of the switching link 44, an intermediate portion of the depth control link 48 is rotatably supported by a pin 49. The upper part of the depth control link 48 is formed into a long groove with an open upper end, and a pin 51 of a projecting piece 50 extending below the position lever 9 is engaged therein. Further, the lower part of the depth control link 48 and the middle part of the feedback shifter arm 25 are connected by a depth transmission link 52 to form a link mechanism 43.

On the other hand, an inner wire 5 of a Bowden wire cable 54 connected to the sensor section 53 shown in FIGS. 4 and 5 is attached to the lower end of the sensor response link 35.
5 is attached, and one end of its outer cable 56 is fixed to the hydraulic case 17.

The sensor section 53 is supported by the rear end of the support frame 3 of the rotary tiller 2. To explain this sensor section 53 in detail, the upper end of a leveling plate 57 which also serves as a rear cover is supported at the rear end of the support frame 3 by a hinge 58 so as to be able to swing in the vertical direction. At the top of the opened support frame 3 is a fulcrum shaft 5.
9 is rotatably suspended horizontally. Further, on the flat plate 57 which is spaced apart from the fulcrum shaft 59, a Bowden wire support shaft 60 is disposed opposite to the fulcrum shaft 59.
is hung horizontally so that it can rotate freely. The upper ends of guide pins 61 and 62 are screwed and fixed to both ends of the fulcrum shaft 59, and their lower ends are slidably supported through the Bowden wire support shaft 60. Guide pins 61, 6 supported in this way
Stoppers 63, 63 are provided at the lower end of 2 to prevent the leveling plate 57 from hanging down more than necessary. Further, an L-shaped wire support rod 64 extends from the lower end of one of the guide pins 61 and 62. This wire support rod 6
4, the other end of the inner wire 55 of the Bowden wire cable 54 is attached. The other end of the outer cable 56 is fixed to the Bowden wire support shaft 60. Incidentally, springs 65, 65 are compressed on guide pins 61, 62 between the fulcrum shaft 59 and the Bowden wire support shaft 60. The springs 65, 65 always urge the leveling plate 57 downward to have a leveling effect and also prevent the leveling plate 57 from swinging unnecessarily due to body vibrations or the like while the vehicle is running.

The link ratio between the depth control device configured in this manner and the position control device 5 described above is such that, assuming that the switching link 44 is fixed, the valve link 20 in the neutral position rotates around it. It is designed to move.

To determine the plowing depth of the rotary plowing section 2 relative to the ground surface while the tractor 1 is running, first tilt the depth lever 28 in the direction of arrow A in FIG. It is rotated in the direction of arrow S to position this hanging portion so that it can engage with the pin 46 at the upper end of the switching link 44. Although the details will be described later, by appropriately rotating the depth lever 28, the engagement distance between the hanging portion 47 of the contact link 40 and the upper end of the switching link 44 can be changed.
This makes it possible to adjust the setting position of the depth control, and by rotating it to the non-engaged state, the engagement is released and the depth control can be rendered inactive.

In this way, by rotating the depth lever 28,
After setting the hanging portion 47 of the contact link 40 to a position where it can engage with the pin 46 at the upper end of the switching link 44 (set engagement position of the link mechanisms 34 and 43), in order to lower the ascending rotary tiller 2. When the position lever 9 is moved fully in the direction of arrow B in FIG.
0 moves in the direction of arrow F in FIG. 3 to move the spool 19 from the neutral position to the lowered position. Therefore, the hydraulic cylinder retreats and lowers the lift arm 6 in the direction of arrow I in FIG. 2 (the position setting position of the rotary tiller 2).

Note that when the position lever 9 is lowered in the direction of arrow B in FIG. 2, the switching link 44 temporarily moves in the direction of arrow L as shown in FIG. 2, but the rotary tiller 2 is still raised. Therefore, the leveling plate 57 is located at the lowest position (solid line position in FIG. 4). Therefore, since the sensor response link 35 is moving in the direction Q in FIG. 2, when the switching link 44 moves in the direction of the arrow L, the contact link 40 does not prevent the switching link 44 from moving in the direction of the arrow L.

When the lift arm 6 descends in the direction of arrow I in FIG. If you want to, move the position lever 9 fully lowered in the direction of arrow B as described above, and then move it slightly B from the direction of arrow A.
If the lift arm 6 is lowered in the direction and stopped, the set height of the position control device 5 is higher than the set plowing depth of the depth control device 8. Stop. When the position lever 9 is fully lowered as described above, as the rotary tiller 2 descends, the leveling plate 57 touches the ground and then rises from the solid line position in FIG. 4 in the direction of the arrow X.

Then, as shown in FIG. 4, the Bowden wire support shaft 60 is brought into contact with the stopper 63.
are separated and the inner wire 55 of the Bowden wire cable 54 is pulled in the direction of the arrow Y, so the sensor response link 35 is moved away from the pin 36 in the Y direction in FIG.
Rotates around. Therefore, push link 3
7 moves in the direction R in Figure 2, so the contact link 4
The hanging portion 47 of 0 is the pin 4 at the upper end of the switching link 44.
6. This is the switching point between position control and depth control. When this switching point is reached, the position lever 9 is fully lowered in the direction of arrow B as described above, and the tilling depth of the rotary tiller 2 relative to the machine body 4 is set to be deep by the position control device 5. Therefore, the sensor section 53 is activated before the feedback mechanism 5b of the position control device 5 acts.
detects the height of the rotary tiller 2 relative to the ground surface, and the depth control device 8 operates preferentially.

That is, after the hanging part 47 of the contact link 40 contacts the pin 46 at the upper end of the switching link 44, when the lift arm 6 further descends, the leveling plate 57 rotates in the X direction in FIG. 35, contact link 4 via push link 37
0 rotates the switching link 44 in the direction of arrow M in FIG. Therefore, the joint pin 25a of the feedback shifter arm 25 is rotated in a direction away from the stopper 23 against the spring 24 via the depth control link 48 and the depth transmission link 52, and the arm pin 27 is rotated in the direction indicated by the arrow in FIG. It rotates in the K direction to return the spool 19 from the lowered position to the neutral position. As a result, the lift arm 6, that is, the rotary tilling section 2, stops descending at the tilling depth H due to the action of the depth control device 8, and thereafter the depth is controlled to follow the unevenness of the ground surface.

The switching point between position control and depth control (the contact position between the hanging portion 47 of the contact link 40 and the pin 46) is the depth lever 2.
It is determined by the setting position of the contact link 40 according to 8. That is, since the hanging portion 47 of the contact link 40 moves in an arc around the pin 41 due to the operation of the depth lever 28, the position where the hanging portion 47 contacts the pin 46 is at the same position as the hanging portion 47 in the longitudinal direction of the fuselage 4. It can be freely set within the engagement range with the pin 46. Therefore, the hanging portion 47 of the contact link 40 is
If the hanging portion 47 and the pin 46 are rotated in the
If the leveling plate 57 is rotated slightly in the X direction, the hanging portion 47 and the pin 46 will be engaged with each other if the leveling plate 57 is rotated slightly in the X direction.

As a result, the depth control starting point is at a position where the tilling depth of the rotary tiller 2 is deep in the former case, and at a shallow position in the latter case. In this way, the plowing depth of the rotary plowing section 2 can be freely adjusted by the operator simply operating the depth lever 28 from the driver's seat of the tractor 1.

If there is an obstacle in the field and you want to cancel the depth control, rotate the depth lever 28 in the direction of arrow B in FIG. In this state, the position control device 5 automatically becomes ready for operation.

As described above, the present invention constantly sends both the work equipment height detection signal and the work equipment position detection signal to the control device such as the switching valve that controls the work equipment lifting device over the entire lifting range of the work equipment. Even if the machine is designed to perform feedback, a link mechanism that responds to a sensor installed in the feedback path and a feedback link mechanism are used to detect when the work equipment position detection signal instructs the work equipment to raise or stop. ,
The work implement height detection signal can be automatically disconnected and the feedback path of the work implement position detection signal can be prioritized.

Moreover, the set engagement position between the feedback path of the work equipment position detection signal and the link mechanism installed opposite thereto can always be kept constant over the entire feedback operation range of the work equipment height detection signal. The plowing depth of the work equipment can be set by changing the set engagement position of the depth control device by adjusting the movement of the link mechanism without changing the set engagement position of the link mechanism by setting the position of the control device. However, the operation start position of this depth control is not connected to the position control device as in the past.
There is no need for troublesome operations such as maintaining only the linked state with the depth control, and while the automatic path where both detection signals are fed back is enabled, the set engagement position of the link mechanism installed opposite to the feedback path can be changed. Since it is only necessary to change the structure, the operation is very simple, and the operator does not operate the working machine by mistake, thereby preventing damage to the working machine.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and Fig. 1 is an overall left side view, Fig. 2 is a left side view of the main part, Fig. 3 is a right side view of the main part, and Fig. 4 is a position of the depth control device. An enlarged left side view of the detection unit, FIG. 5 is a partially omitted plan view, FIG. 6 is a sectional view along the line of FIG. 2, FIG. 7 is a sectional view along the line of FIG. 2, and FIG. 8 9 is an expanded sectional view showing the relationship between the position lever and the feedback link, FIG. 9 is an enlarged left side view of the valve operating link, and FIG. 10 is an enlarged perspective view of the main parts. 2... Rotary tilling section (work machine), 4... Airframe, 5
...Position control device (hydraulic lifting device),
8... Depth control device, 28... Depth lever, 34... Link mechanism linked to sensor section 53, 43... Link mechanism linked to position control device, 53... Sensor section, 57... Leveling plate (sensor).

Claims (1)

[Scope of Claims] 1. A work machine lifting device for power agricultural machinery, which is equipped with a position control device that controls the height of the work machine with respect to the machine body, and a depth control device that controls the position of the work machine with respect to the ground surface. A control device such as a switching valve to be controlled receives both a work equipment height signal that detects the height of the work equipment relative to the machine body and a work equipment position signal that detects the work equipment position relative to the ground. A link mechanism that enables constant feedback over the entire feedback operation range of the ground detection signal, and a link mechanism that responds to a sensor that senses the ground surface and operates in conjunction with a depth control device installed opposite to the feedback path, and a position control device. When the work equipment position detection signal instructs the work equipment to rise and stop, the feedback link mechanism connected to the
The work equipment height detection signal is automatically disengaged to give priority to the feedback path of the work equipment position signal, and the set engagement position of the feedback path and the link mechanism provided opposite thereto is set according to the work equipment height. A working machine elevating device for a power agricultural machine, wherein the feedback of a depth detection signal is constant over the entire range of operation, and the set engagement position is movable to change the operation start position of a depth control device. 2. A working machine elevating device for a power agricultural machine according to claim 1, wherein a link mechanism responsive to a sensor is movably provided. 3. A working machine elevating device for a power agricultural machine according to claim 1, wherein the link mechanism responsive to the sensor is movably provided by a lever provided near the driver's seat.