JPS63169902A - Working machine rising and falling control apparatus of tractor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (a) Industrial Application Field The present invention provides
This relates to a deceleration mode that gradually reduces the descending speed to avoid a sudden collision upon touchdown.

(b) Prior art Conventionally, when lowering a working machine attached to a tractor,
Techniques for changing speed in order to eliminate the impact upon touchdown are known to the public.

For example, Japanese Patent Publication No. Sho 61-34766.

(C) Problems to be Solved by the Invention However, in the prior art, when the lift arm reaches a predetermined position, the speed is changed to a constant slow speed and the lift arm is lowered. In the case of soft fields or especially hard fields, there was a problem in that the length of the headland and the amount of initial penetration when going around the edge of the field became extremely large or small.

Another conventional method is known to slow down the descending speed when the rear cover touches the ground, but in this case too, if the plowing claws touch the ground before the rear cover, the aircraft may dash. Additionally, there was a problem in that if the rear cover hit the ground forcefully first, the rear cover would be damaged.

The present invention aims to solve this problem by setting the interval of intermittent opening and closing of the valve according to the rotational position of the lift arm, gradually reducing the speed as the lift arm descends, and adjusting the speed according to the field conditions. This makes it possible to respond flexibly to various situations.

(d) Means for Solving the Problems The objects of the present invention are as described above. Next, the configuration for achieving the objects will be explained.

In the configuration in which the lift arm 4 is moved up and down, the electromagnetic valve that controls the hydraulic cylinder for the lift arm 4 is configured to open and close intermittently using a pulse signal, and the pulse signal is changed in accordance with the lowered position of the lift arm. , which is configured to gradually slow down the descending speed of the working machine.

In addition, in the intermittent opening and closing of electromagnetic valves, the pulse signal O
The structure is such that the N time is constant and the OFF time is changed.

(e) Embodiments and Functions The objects of the present invention are as described above. Next, the structure of the embodiments shown in the attached drawings will be explained.

Fig. 1 is a side view of the rotary tilling device attached to the tractor, Fig. 2 is a side view showing the rotary tilling device of the present invention in the lowered state, and Fig. 3 shows the rotation angle of the lift arm 4 and the electromagnetic valve. Drawings showing the relationship with OFF time, Fig. 4 is a drawing showing OFF time control in pulse drive, Fig. 5
The figure is a side view showing problems associated with rapid descent.

The configuration of a rotary tiller installed on a tractor in FIG. 1 will be explained.

A tilling cover 5 covers and stands on the outer periphery of the rotation locus of the tilling claws 1, and a rear cover 2 is pivotally supported at the rear of the tilling cover 5. The rear cover 2 also serves as a sensor for automatic reverse control, and the rotation of the rear cover 2 is transmitted to the rotary encoder in the control box via a feedback wire 3, changed to an electrical value, and after comparison with the set value, It is transmitted as a pulse signal to control the electromagnetic valve, and is used to switch and operate the electromagnetic valve.

In the rotary tilling device of this configuration, the tilling cover 5 is adjustable back and forth, and is adjusted back and forth using a tilling cover adjustment handle 16.

Furthermore, when the tilling cover 5 is adjusted back and forth, the rear cover 2 is also adjusted back and forth accordingly. 17 is a depth wheel adjustment handle.

In this way, the present invention is attached to a work equipment mounting device of a tractor, and when the rotary tilling device is raised and lowered by the lift arm 4, the rotary tilling device is raised all at once for going around the field edge, and after going around, the rotary tilling device is tilled again. This relates to slow descent when lowering the rotary tiller to return to its original position.

Figures 2 and 5 show the situation when the tractor starts plowing work again after turning around at the edge of the field.

If a slow descent device is not provided at the time of ground contact, the tilling claws 1 will dig deep from the ground surface due to the inertial force of the rapid descent as shown in FIG. 5, and the amount of penetration will become large. The large part of this digging lh is concentrated in the headland area, and the headland is deeply gouged.

Furthermore, even if a slow descent device is provided at the time of ground contact, if the speed during slow descent becomes too slow, the insertion distance l shown in Fig. 2
This results in too long and uncultivated land on the headland.

The present invention brings the penetration distance close to O, and also reduces the penetration distance! It should also be as short and concise as possible.

In the present invention, even when opening the electromagnetic valve that operates the lift arm 4, oil is supplied by opening and closing intermittently using pulse signals.

The driving configuration for intermittent opening and closing using the pulse signal is set as shown in FIG.

That is, the ON time tQ during which the solenoid of the electromagnetic valve is energized to open the oil passage is constant, and this constant time is the time during which the lift arm 4 changes by 2 degrees in lift angle, as shown in FIG. The ON time during which the solenoid should be energized is set to be constant.

As the lift arm 4 descends, in order to gradually slow down the descending speed, the ON time of the solenoid is the same, so the length of the solenoid OFF time t1 and t2 that is created between the ON time is determined. is changing.

That is, the OFF times t1 and t2 are determined by dividing the angle of the lift arm 4 into 5 stages from 0 degrees at the lowest position to 70 degrees at the highest position, as shown in FIG. It is configured to change the time in five steps up to seconds.

Therefore, as the lift arm 4 descends, the OF of the pulse signal
Since the F time changes as shown in FIG. 3, the descending speed of the rotary tiller also gradually slows down as shown in the graph of FIG.

As a result, the speed when touching the ground surface is slowed down to almost zero, and the plowing depth is automatically controlled.

When traveling along the edge of a field, the rotary tiller is raised to the highest position by rotating the position control lever to the highest position while leaving the automatic tilling depth control in the same state. When the operator operates the position control lever to the lowest position or below the setting position of the automatic tillage depth control, the slow lowering is performed only until the tillage falls within the range of the automatic tillage depth control. When the tiller enters the automatic tillage depth control area, the tillage operation automatically continues under the automatic tillage depth control that was in effect before reaching the edge of the field.

FIG. 6 is a speed curve when slow descent is configured by the shape of the lowering check valve 7 provided in the mechanical hydraulic valve V, FIG. 7 is a side view showing the relationship between the hydraulic operating lever 9 and the lift arm 4, FIG. 8 is a hydraulic circuit diagram of the configuration, FIG. 9 is a sectional view of the hydraulic valve V of the configuration, and FIG. 10 is a lowering check valve 7.
11 and 12 are cross-sectional views of conventional lowering check valves 27 and 37.

The lowering check valve 7 is shown in the hydraulic circuit diagram in FIG. 11 to be pressed and operated.

Conventionally, the lowering check valve 7 was not given the purpose of slow lowering, so as shown in FIGS. 11 and 12,
It was constructed in the shape of a short poppet valve, and the poppet valve had only two uses: to open or to close.

In this configuration, the lowering check valve 7 is not a check valve that only opens and closes, but a poppet valve portion 7b for closing.
In addition, a taper portion 7a for aperture is provided.

With this configuration, when the lowering check valve 7 does not fully retreat but retreats by the distance m shown in FIG. It is.

When the lift arm 4 is placed in the highest position for rounding the field edge, the lowering check valve 7 is closed, and when the lift arm 4 is to be lowered after finishing rounding, the operator moves the hydraulic operating lever 9 to the lowest position. However, as the lift arm 4 descends, the switching spool 6 and the lowering check valve 7 are gradually pushed back toward the neutral side as a unit by operation from the feedback mechanism.

When the feedback mechanism returns the lowering check valve 7, until the lowering check valve 7 is completely closed,
The aperture taper part 7a is arranged so that the aperture effect is gradually exerted.
It has been established.

In addition, as shown in FIG. 7, if a stopper 8 is projected within the rotation locus of the hydraulic operating lever 9 and the stopper 8 is made detachable, the hydraulic operating lever 9 can be moved to the lowest position. It is possible to stop at a distance m shown in FIG. 10 without rotating up to 9 degrees, and in this state, it is possible to start descending with the throttling effect of the throttling taper portion 7a exerted.

Moreover, if the stopper 8 is removed, the check valve 7 can be lowered to the position of the distance n shown in FIG. When the check valve 7 is gradually pushed back by the feedback mechanism and the throttling taper portion 7a begins to be fitted into the spool hole, the throttling effect gradually begins to be exerted.

With this configuration, it is possible to perform a slow descent gradually, rather than stepwise as shown in FIG.

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

First, the descending speed is gradually slowed down according to the angle of the lift arm 4 during descending, instead of changing the descending speed all at once when a certain descending position is reached as in the conventional technology. Therefore, even when the field is particularly hard or particularly soft, it is possible to shorten the insertion distance β of the tiller claws 1 in almost the same way as in normal cases, and the penetration lh can be brought close to 0. be.

Second, we configured a deceleration mode for slow descent by using an electromagnetic valve instead of the hydraulic valve and adjusting the intermittent opening/closing interval using pulse signals, so the reduction ratio for this deceleration mode can be easily set using an electrical setting dial. Therefore, it is possible to easily set the optimum slow descending speed according to the field conditions.

Thirdly, the slow descent of the solenoid valve is set constant during the 08 hours of pulse drive, and the deceleration mode is configured by changing the OFF time, so that when changing <08 hours as in the past, In the above, when the amount of oil discharged changed due to fluctuations in engine speed or oil temperature, the descending speed changed accordingly, but 08 hours was set as the time when the rotation angle of lift arm 4 changed by a certain amount. However, by setting this as a constant time, the deceleration is set by the length of the OFF time, so even if there is a change in the amount of discharged oil mentioned above, the descending speed will not change, and a constant slow descending will be obtained. This has become possible.

[Brief explanation of the drawing]

Fig. 1 is a side view of the rotary tilling device attached to the tractor, Fig. 2 is a side view showing the rotary tilling device of the present invention in the lowered state, and Fig. 3 shows the rotation angle of the lift arm 4 and the electromagnetic valve. Drawings showing the relationship with OFF time, Fig. 4 is a drawing showing OFF time control in pulse drive, Fig. 5
The figure is a side view showing a problem caused by rapid descent, and Figure 6 is a lowering check valve 7 installed in a mechanical hydraulic valve ■ for slow descent.
Figure 7 is a side view showing the relationship between the hydraulic operating lever 9 and the lift arm 4;
The figure is a hydraulic circuit diagram of the configuration, Figure 9 is a sectional view of the hydraulic valve (1) of the configuration, Figure 10 is a drawing showing the configuration of the lowering check valve 7, and Figures 11 and 12 are conventional lowering check valves. 27
- It is a sectional view of No. 37. 1...Tilling claw 4...Lift arm...Insertion distance h...Amount of penetration Applicant Yanmar Diesel Co., Ltd. Agent Patent attorney Hisashi Yano - Department Figure 2 Figure 5 Figure 3 Figure 4 Figure 7 A

Claims (2)

[Claims] (1). In the configuration in which the lift arm 4 is moved up and down,
The electromagnetic valve that controls the hydraulic cylinder for the lift arm 4 is configured to be opened and closed intermittently by a pulse signal, and the pulse signal is changed in accordance with the lowering position of the lift arm to gradually slow down the lowering speed of the work machine. A tractor working equipment elevation control device characterized by being configured as follows. (2). In the intermittent opening and closing of the electromagnetic valve according to claim 1, the ON time of the pulse signal is constant and the pulse signal is OFF.
A tractor work equipment elevation control device, characterized in that it is configured to change time.