JPH0449853Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field This invention maintains a constant horizontal inclination angle of the working equipment when it is mounted on a tractor and is raised to the highest position when going around the edge of a field. This invention relates to a configuration for canceling a slope control device and returning the tractor to a specified position, and for canceling an automatic plowing depth control device.

(b) Prior art The technology of the left and right tilt control device for a working machine is known, and the tilt control device is released when the working machine rises to the highest position, and the working machine is moved against the body of the tractor. Techniques for returning to the parallel specified position are also known.

For example, Japanese Patent Application Laid-open No. 71310/1983.

(c) Problems to be solved by the invention In the invention, the operating mechanism for the hydraulic valve that controls the lifting and lowering of the lift arm has a conventional mechanical structure, and is provided at the tip of the hydraulic operating lever shaft and the cylinder shaft. It is configured to be operated by a push pin, and in addition to the mechanical operating mechanism, an operating mechanism using a control motor M is provided to enable electrical control.

In other words, an electric sensor detects when the tractor's gear is shifted into reverse, or when the tractor reaches the edge of the field and is about to turn, and electrically switches and controls the hydraulic valve. Therefore, the operating portion of the hydraulic operating lever shaft 16 is configured electrically.

In addition, the operation for raising the work equipment when going around the edge of the field is not done by a position control lever, but by a mechanical hydraulic valve and control motor M, in order to enable raising operation by a simple switch operation using a hand-held lift switch. This relates to the arrangement of a raised position detector when an electric operating mechanism is also provided.

Conventionally, there was no operating mechanism using the control motor M, so it was sufficient to place a rising position detector on the position operating lever, but if an electrical operating mechanism using the control motor was also installed. Since priority is given to the electric operating mechanism, the elevated position detector is provided opposite to the electric control arm rotated by the control motor.

(d) Means for solving the problem The purpose of the present invention is as described above. Next, the configuration for achieving the purpose will be explained.

In a hydraulic valve that controls the elevation of a lift arm, a control motor is disposed near a hydraulic operating lever shaft that pushes and operates a spool of the hydraulic valve,
The electric control arm 7 controls the forward and reverse rotation of the control motor.
A lift position detector is disposed at a position facing the electric control link.

(E) Embodiment The purpose and structure of the present invention are as described above. Next, the structure of the embodiment shown in the attached drawings will be explained.

FIG. 1 is an overall plan view of the tractor of the present invention, FIG. 2 is a side sectional view of the control motor M and hydraulic operating lever shaft 16, FIG. 3 is a rear view, and FIG. 4 is a hydraulic operating lever. FIG. 5 is a rear sectional view of the shaft 16 portion, and a plan view of the electric control arm 7 portion.

The configuration of the tractor of the present invention will be explained with reference to FIG.

A steering handle 30, which performs rotational steering operation when the tractor reaches the edge of the field, and left and right steering brake pedals 31L, 31R are arranged. A turning steering sensor is provided at the steering handle 30 and the steering brake pedal 31, and when it senses that the tractor is turned significantly, the control motor M is activated even if the operator does not raise the work equipment. It rotates to switch hydraulic valves.

In addition, the lever guide plate 2 installed on the right side of seat S
5, a hand lift switch 24 and a gear shift lever 8 are provided. 8 is provided at a position where it comes into contact when it rotates to the reverse position.

Further, in a position in front of the hand lift switch 24, a reverse movement alarm buzzer 32 is arranged to issue an alarm when the speed change lever 8 is shifted to the reverse position.
Furthermore, at the rear of the hand lift switch 24, there is a reverse lift setting switch 3 which can configure a state in which the work equipment does not rise even if the gear shift lever 8 is set to reverse.
3 is provided.

The operator can easily raise the work machine without rotating the position control lever 1 by rotating the hand lift switch 24, which is configured with a neutral position return type switch, backward. It is.

In the elevated position detector of the present invention, a tilt control return switch 6 is provided at the base position of the position control lever 1, and the tilt control return switch 6 is turned ON.
When the work equipment rises to such an extent, a signal is generated from the control box, and the tilt control hydraulic cylinder 34, which has been installed on the lift link 19 between the lift arm 28 and the lower link 17, is activated. The tilt control state that was performed by the expansion and contraction of the tilt control cylinder 34 is canceled, and the tilt control hydraulic cylinder 34 returns to the position before the start of the control in which the work implement is parallel to the tractor.

In addition, automatic tilling depth control, which was performed by raising and lowering the lift arm 28 by detecting changes in tilling depth using the rear cover as a sensor, is now detected by the automatic depth control switch 18, which is another lifting position detector. It is not necessary when going around the edge of the field, so it is canceled.

2 is a depth control lever, and 28 is a lift arm.

Next, the configuration of the control motor M and the hydraulic operating lever shaft 16 will be explained with reference to FIGS. 2, 3, 4, and 5.

A hydraulic case C is mounted and fixed on a transmission case of a tractor, and a hydraulic valve is arranged inside the hydraulic case C. Further, a top spring hinge 15 is provided on the rear surface of the hydraulic case C to detect the traction load related to the working machine during draft control. Further, in the front part of the hydraulic case C, a pilot valve 12 for extracting hydraulic pressure to the outside and a hydraulic valve 14 for extracting the hydraulic pressure to the outside are arranged.

The hydraulic valve of the present invention is fixed to the lower surface of the hydraulic case C, and as shown in FIG. 4, the control bar in contact with the spool is pushed by push pins 21 and 22 to cause the spool to extend or retreat. Do it.

In the conventional configuration, the position control lever 1 is fixedly attached to the inner hydraulic control lever shaft 16 of the lever shaft configured as a double shaft, and the depth control lever is fixed to the cylindrical shaft 20 outside the lever shaft. The base of 2 was fixed.

In the present invention, the depth control lever 2 is fixed to the cylinder shaft 20, but in the conventional case,
The position control lever 1 is the hydraulic control lever shaft 16
The position operating lever 1 is configured to be loosely fitted to the hydraulic operating lever shaft 16, and the base of the position operating lever 1 only comes into contact with the locking piece 9 of the electric control arm 7. As a result, the position control lever 1 and the electric control arm 7 can be rotated together, and serve the same role as the conventional position control lever 1.

However, since the position control lever 1 is loosely fitted to the hydraulic control lever shaft 16 and the boss portion 7c of the electric control arm 7 is fixed to the hydraulic control lever shaft 16, the control motor M is driven to rotate. Priority is given to the rotation of the electric control arm 7 accompanying this.

The control motor M is fixedly attached to the vertical edge of the lever guide plate 25, and a reduction mechanism 11 is attached to the control motor M. A rotating arm 3 is fixed to a shaft protruding from the reduction mechanism 11. It rotates forward and backward.

A C-shaped metal fitting 4 is pivotally supported at the tip of the rotating arm 3, and the C-shaped metal fitting 4 changes the rotation of the rotating arm 3 into linear movement of the flexible wire 5.

The tip of the flexible wire 5 is connected to a lower arm 7b of an electric control arm 7 branched into a bell crank shape. The other upper arm 7a is configured to engage and come into contact with a locking piece 9 projecting outward from the position operating lever 1 and an operating piece 6a of the tilt control return switch 6.

The tilt control return switch 6 causes the work implement to come into contact with other parts of the tractor when the work implement approaches the lifting limit position of the lift arm 28 and rises in an angle control state that keeps the horizontal inclination of the work implement constant at a set angle. In order to eliminate this problem, the switch is configured to cancel the tilt control state and return to the horizontal state with respect to the tractor when the lift arm 28 approaches its lifting limit.

Further, a switch operation piece 29 protrudes from the boss portion 7c of the electric control arm 7, and the switch operation piece 29 is configured to turn on the depth automatic control switch 18, which is another ascending position detector. There is. The depth control lever 2 is operated to obtain the automatic depth control state only when the position control lever 1 and the electric control arm 7 are at the lowest position.

Therefore, when the work equipment is raised to go around the edge of the field, or when the work equipment is automatically raised due to reverse gear change, the automatic depth control is automatically turned off. Then, when the position control lever 1 and the electric control arm 7 are rotated again and the automatic depth control switch 18 is turned on, automatic depth control is started.

(f) Effects of the invention The structure of the invention is as described above, and the effects based on the invention will be explained.

A locking piece 9 projects outward from the position control lever 1, and the locking piece 9 is connected to the electric control arm 7.
It is configured to come into contact with the lower end of the upper arm 7a. Therefore, when the position control lever 1 is rotated in the upward direction of the working machine, that is, in the direction of arrow a in FIG. 2, the electric control arm 7 is also rotated in the upward direction by the rotational force of the position control lever 1.
The rotation of the electric control arm 7 causes the hydraulic operation lever shaft 16 to rotate, and the push pin 22 pushes the spool of the hydraulic valve to switch it to the upward side, thereby raising the working machine.

In this case, the difference in the operating position due to the fact that the control motor M is not rotating is absorbed by the bending of the flexible wire 5.

Conversely, when the position control lever 1 is rotated toward the lowering side of the lift arm 28, that is, in the direction of arrow b in FIG. The hydraulic control lever shaft 16 rotates, and the internal push pin 22 rotates back and forth to move the spool backward, and the hydraulic valve is switched to the lowering side.

As disclosed above, when the position control lever 1 rotates, the electric control arm 7 follows and rotates due to the locking piece 9 and the biasing spring 10. This operates in exactly the same way as when the position operating lever 1 is directly fixed to the hydraulic operating lever shaft 16.

When the operator operates the steering handle 30 or steering brake pedal 31 to rotate the machine at the edge of the field at a certain operating position of the position control lever 1, a sensor detects this operation and controls the control motor M. It is rotated in the upward direction.

This upward rotation of the control motor M causes the rotation arm 3 to rotate, the C-shaped metal fitting 4 and the flexible wire 5 to be lifted, and the electric control link 7 to be separated from the locking piece 9 and rotate upward freely. It moves. Due to the rotation of the electric control arm 7 by the control motor M, the electric control arm 7 and the hydraulic operation lever shaft 1 are rotated even though the position operation lever 1 does not move.
Only the arm 6 rotates and the push pin 22 is pushed in to switch to the upward side, causing the lift arm 28 and the rotating arm 3 to rise.

Similarly, when the hand lift switch 24 is operated to the upper side or when the gear shift lever 8 is shifted to the reverse position, the control motor M rotates in the same way to control the electric control arm 7 and the hydraulic operating lever shaft 16. Regardless of the position of position control lever 1,
This raises the work equipment.

When the state detected by the sensor ends or is canceled, the control motor M rotates again,
The position of the steering brake pedal 31 is changed to a position where the electric control arm 7 contacts the locking piece 9 and the steering brake pedal 31 is lowered.

In the above configuration, the control motor M can take only two positions of the electric control link 7, the lowest position and the highest position.

Therefore, when the position control lever 1 assumes a position between them, the flexible wire 5 bends and is forced along the position control lever 1 of the electric control arm 7.

On the other hand, when the sensor detects a state that produces the highest position, the control motor M always rotates the electric control arm 7 to the highest position. As described above, whether only the electric control arm 7 is raised or when the position control lever 1 and the electric control arm 7 are raised, both conditions can be detected by the tilt control return switch 6, which is a raised position detector. Furthermore, the upper arm 7a is configured to operate the operating piece 6a.

The tilt control return switch 6 is connected to the electric control arm 7.
When the switch is turned ON by rotating the electric control arm 7 and the position control lever 1 to the upward side,
The signal from the tilt control return switch 6 is sent to the control box and judged, and as shown in FIG.
The machine moves up and down to return the work equipment to a parallel position with the tractor.

Further, a switch operation piece 29 protrudes from the boss portion 7c of the electric control arm 7, and the switch operation piece 29 is configured to turn on the depth automatic control switch 18, which is another ascending position detector. There is. The depth control lever 2 is operated to obtain the automatic depth control state only when the position control lever 1 and the electric control arm 7 are at the lowest position.

Therefore, when the work equipment is raised to go around the edge of the field, or when the work equipment is automatically raised due to reverse gear change, the automatic depth control is automatically turned off. Then, when the position control lever 1 and the electric control arm 7 are rotated again and the automatic depth control switch 18 is turned on, automatic depth control is started.

(g) Effects of the invention Since the invention is constructed as described above, it has the following effects.

First, when the hydraulic operating mechanism is configured such that the hydraulic valve side is a mechanical operating mechanism, and the side that pushes the spool of the hydraulic valve is configured to be operable by electric signals from the control motor M, it is possible to control the position as in the conventional case. If the raising position detector is arranged to detect only the rotation of the operating lever 1, there is a possibility that the raising operation of the hydraulic valve by the control motor M may be overlooked.

In the present invention, by providing the tilt control return switch 6 and the automatic depth control switch 18 as a rise position detector corresponding to the electric control arm 7, it is possible to overlook the rise operation caused by the operation on the control motor M side. is gone.

Second, since the tilt control return switch 6 and the automatic depth control switch 18, which constitute the ascent position detector, are arranged between the hydraulic operating lever shaft 16 and the control motor M, the surrounding area is S and the lever guide plate 25 can be used to cover the tractor, thereby preventing mud, water spray, etc. from entering even when the tractor runs through rice fields.

[Brief explanation of the drawing]

Fig. 1 is an overall plan view of the tractor of the present invention, Fig. 2 is a side sectional view of the control motor M and the hydraulic operating lever shaft 16, Fig. 3 is a rear view, and Fig. 4 is the hydraulic operating lever. FIG. 5 is a rear sectional view of the shaft 16 portion, and a plan view of the electric control arm 7 portion. M... Control motor, 1... Position operating lever, 2... Depth operating lever, 3... Rotating arm, 4... C-type metal fitting, 5... Flexible wire, 6
...Tilt control return switch (raised position detector),
7... Electric control arm, 7a... Upper arm, 7
b...lower arm, 8...shift lever, 9...locking piece, 18...depth automatic control switch (ascent position detector).

Claims (1)

[Scope of utility model registration request] In a hydraulic valve that controls the elevation of a lift arm, a control motor is disposed near a hydraulic operating lever shaft that pushes and operates a spool of the hydraulic valve,
A hydraulic control mechanism for a tractor, characterized in that forward and reverse rotation of the control motor is transmitted to a hydraulic control lever shaft via an electric control arm, and a rising position detector is disposed at a position facing the electric control arm.