JPH06209604A - Work machine lift control device - Google Patents

Abstract

(57) [Abstract] [Purpose] The PTO system is driven during the process of descending the working machine, and when it enters the soil, the target rotation is used to suppress the resistance at the initial stage of driving and reduce unworked parts. The purpose is to [Structure] A hydraulic device 5 having a lift arm 4 which is moved up and down via a control valve 14 which is switched up and down by a signal of an operation of a manual switch 13, and a PT which is turned on and off by a manual operation.
A traveling power vehicle 1 having a PTO shaft 10 interlocking with an O-type clutch 8 and a working machine 3 having a working portion 3A interlockingly connected to the PTO shaft 10 can be raised and lowered via a link mounting device 2. It is installed. A descending speed control circuit 31 is provided to turn on the PTO system clutch 8 and bring the PTO shaft 10 to a target rotation while the working machine 3 being lifted by the lift arm 4 is descended.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a working machine lifting control apparatus and is used for carrying out cultivating work by mounting a working machine such as a rotary on a tractor so that the working machine can be lifted and lowered.

[0002]

2. Description of the Related Art In a tractor (running power vehicle) equipped with a hydraulic device having a lift arm for raising and lowering a working machine such as a rotary, a control valve for switching the hydraulic device up and down is operated by a switch operated by an electric signal. It is provided. For example, as disclosed in Japanese Examined Patent Publication No. 4-74965, a lift sensor is attached to a lift mechanism that raises and lowers a work machine, and a lift limit detection value detected by the lift sensor when the lift mechanism is lifted after engine start is set. This is a technology in which the microcomputer stores the value and the stored value is used as the upper limit for the subsequent rise of the working machine.

[0003]

However, the above-mentioned technique does not mention whether or not to drive the PTO system when the working machine lifted by the lift arm is lowered. Further, when the working machine descends and the PTO system is driven when the working part of the working machine penetrates into the soil,
There is a problem that the resistance in the initial stage of driving becomes excessive and the unworked portion becomes large.

Therefore, according to the present invention, the PTO system is driven in the process of lowering the working machine, and the target rotation is performed when the work machine enters the soil, thereby suppressing the resistance in the initial stage of driving and reducing the unworked portion. The purpose is to

[0005]

According to the present invention, there is provided a hydraulic device 5 having a lift arm 4 which is lifted and lowered via a control valve 14 which is switched up and down by a signal of an operation of an artificial switch 13, and an on / off operation by an artificial operation. In the traveling motor vehicle 1 including the PTO shaft 10 that is interlocked with the PTO system clutch 8 that is turned off, the P
In order that the working machine 3 having the working unit 3A interlockingly connected to the TO shaft 10 is mounted via the link mounting device 2 so as to be able to move up and down, the following technical means are provided in order to achieve the above-mentioned object. I am taking it.

That is, according to the present invention, the PTO system clutch (8) is turned on and the PT is turned on during the process of lowering the working machine (3) lifted by the lift arm (4).
The descent speed control circuit (3
1) is provided.

[0007]

When the working machine 3 is lowered by the lift arm 4 via the link mounting device 2, the PTO system clutch 8 is turned on and the lowering speed of the working machine 3 is controlled to control the PTO shaft 1.
The circuit 31 controls 0 to the target rotation.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1 (B), a traveling power vehicle 1 illustrated by a two-shaft, four-wheel type tractor is illustrated by a three-point link. A work machine 3 exemplified by a rotary is mounted via a link mounting device 2 so as to be able to move up and down. The traveling power vehicle 1 is provided with a hydraulic device 5 having a pair of left and right lift arms 4. By connecting the lift arm 4 and the left and right lower links with a lift rod 6, the working machine 3 can be raised and lowered. Along with the power of the engine 7, the PTO system clutch 8,
A PTO shaft 10 that is interlocked via a PTO system transmission 9 is provided, and the PTO shaft 10 and the PIC shaft are interlockingly connected by a joint shaft 11, so that a working portion (plow tab) 3A of the working machine 3 is provided.
Can be driven and rotated.

As shown in FIG. 2, the hydraulic device 5 has a piston 5B slidably fitted in a hydraulic cylinder 5A and is connected to a lift arm 4 via a piston rod 5C and an interlocking arm 4A. The control valve circuit 12 of the hydraulic device 5 is a switch 1
A control valve 14 of an electromagnetic proportional type that can be switched up and down by a signal by a manual operation of 3 is provided, and pressure oil from a pump 15 driven by an engine is hydraulically supplied through a check valve 16, a fall speed adjusting valve 17 and the like. Liquid can be sent to the cylinder 5A.

In FIG. 2, reference numeral 18 is a relief valve, 19 is an unload valve, the position of the control valve circuit 12 including these valves can be controlled, and it is operated by an electric signal by turning on / off a switch 13. As shown in FIG. 3, a lift arm upper limit sensor 20, an upper limit setting dial 21 and the like are provided, and the switch 13 and the dial 21 are provided near the steering handle of the traveling power vehicle.

The PTO system clutch 8 is a hydraulic clutch which is connected / disconnected via an electromagnetic control valve which is turned on / off by operating a switch 22, its human side is directly connected to the engine, and its output side is a PTO transmission. 9 connected, PTO shaft 1
It is linked to 0. As shown in FIG. 1A, the PTO control including the PTO switch is interlocked to automatically control the hydraulic control valve 14 when the PTO switch 22 is turned on or off from the start, as shown in FIG. The microcomputer unit 23 shown in FIG.

The microcomputer unit 23 shown in FIG.
An automatic PTO control unit 24 is provided, and a signal from the control valve switch 13, a signal from the PTO switch 22, and a signal from the lift arm upper limit setting dial 21 are input and stored in the control unit 24, and an engine rotation signal 25, PTO
The shift position signal 26 and the PTO rotation signal 27 are the target PTO rotation control unit 28 and the PTO connection state calculation unit 2, respectively.
9 and is stored in the control unit 24.

The steps from the start to the end of the control of the hydraulic-automatic PTO control section 24 are shown in FIG. 1 (A), and are controlled as follows. In FIG. 1 (A), P
In the first step S1 from the start of TO control, ON (including automatic) and OFF of the PTO switch 22 is detected, and when it is OFF, the automatic PTO control safety circuit 30 described later is turned OFF and the PTO system clutch is turned OFF to finish. To do.

On the other hand, when the PTO switch 22 is on, the safety circuit 30 detects whether the safety circuit 30 is on or off in the second step S2, and when it is on, the PTO clutch is turned off to end the operation.
When the PTO switch 22 is off, it is detected in a third step S3 whether the PTO switch 22 is on or automatic. If the PTO switch 22 is turned on in the third step S3, the PTO clutch is turned on and the process ends.

On the other hand, in the third step S3, automatic (AUT
O), the control valve switch 13 is turned on or off
This is detected in step S4. Here, in the fourth step S4, ON means that the control valve 14 has been switched to the upward position, and conversely, OFF means that the control valve 14 has been switched from the lift arm upper limit position to the downward position.

When the signal is the ON signal in the fourth step S4, the lift arm upper limit condition is determined and detected in the fifth step S5. Here, the lift arm upper limit condition is a position lower than the upper limit position set by the dial 21 by, for example, about 10 °, and this is detected by the lift arm sensor 20. Therefore, when the signal is NO in the fifth step S5, the lift amount by the hydraulic device 5 is insufficient, so the PTO clutch remains on, and here the working unit 3A continues to rotate and the signal YES When is hydraulic device 5
Means that the working portion 3A is in the non-working posture (position of height 3AH in FIG. 2), and therefore the control circuit works to turn off the PTO clutch, while the control valve 14 Keeps the lifting circuit and lifts the working machine through the lift arm 4 to the highest position H shown in FIG.

In the fifth step S5, a YES signal is output, and it is judged in step S6 whether or not a predetermined time has elapsed, and the time is not reached. That is, when NO, the PTO clutch is turned off, but the safety circuit 30 is activated when a predetermined time has passed, for example, 30 seconds or more.
That is, in the sixth step S6, if there is no down signal even after 30 seconds or more, for safety, even if the switch 13 is lowered after 30 seconds, the PTO clutch 8 does not turn on, and the PTO clutch 8 must be restored to restart. If the switch 22 is turned off once and the PTO switch 22 is not turned on again, the PT
A safety circuit 30 that does not drive the O-axis 10 is provided.

As a result, for example, when the rotary work is completed, the control valve switch 13 is operated to be raised, and the control valve 14 is switched to the raised state by the signal to lift the rotary (working machine). However, when the switch 13 is lowered, the PTO shaft 1
0 is in a state of starting rotation. When a worker forgets this state and, for example, travels on the road with the work implement 3 lifted to store the traveling motor vehicle 1 in the barn, the work unit 3A unexpectedly rotates when the work implement 3 is lowered. Can be prevented.

Next, in the fourth step S4, when the lift arm 4 is lowered for starting the work from the state where the work machine 3 is lifted to a predetermined position, the control valve switch 13 is operated to be lowered. When the control valve 14 is switched from the neutral position to the lowered position by the signal, the working machine 3 is lowered to the position position. At this time, in the seventh step S7, the lift arm sensor 20 detects the lift arm upper limit condition (lowering the lift arm upper limit position by -10 °, that is, 10 °), and when the PTO is on, the PTO is turned on.
The shaft starts modulation at the same time as the working machine descends, and the working machine 3 moves to the PTO shaft 10 at the lower limit of, for example, -10 °.
The control unit 31 controls the falling speed of the automatic PTO working machine 3P so as to achieve the target rotation speed.

Specifically, the rotation speed of the PTO shaft 10 is 54
The throttle valve 17 is controlled so as to be 0 rpm or 1000 rpm. The control valve switch 13 can be switched between three positions, that is, a raising position, a lowering position, and a neutral position of the working machine, and the raising and lowering is a momentary switch. In addition, various monitors are provided on the panel near the steering handle of the traveling power vehicle 1, and the up / down monitor of the lift arm is provided in the road traveling caution monitor, and blinks only when the switch 13 is raised. It is supposed to do.

When the position dial is raised to the designated position of the lift arm in this state, the monitor lamp is turned off. At this time, the control by the electric signal of the control valve 14 is released, and thereafter, even if the position dial is lowered or raised, the electric control does not return to the electric control, and the working machine is position-controlled to the position set by the position dial. Further, the PTO monitor lights up even when the PTO is rotating and is temporarily stopped by the raising signal of the control valve switch 13,
Is turned on or off by turning off the PTO switch 22 and is provided in the road monitor.

Further, adjustments such as raising of the working machine are made as follows. Designated position of work implement 3 (upper limit position)
Is adjusted by the lift arm upper limit dial 21. When the dial 21 is moved while the switch 13 in the hydraulic operation panel is turned on, the working machine 3 position-controls and follows the target position, which allows adjustment.

When the position of the lift arm upper limit dial 21 is lower than the position of the position dial, and the actual position of the lift arm 4 is lower than the position of the position dial, the automatic operation of the hydraulic control valve is canceled. ,
It is effective if the lift arm upper limit dial is quickly moved before that so that the actual position of the lift arm does not fall below the position of the position dial.

When the engine is stopped, the automatic operation of the hydraulic control valve (operation by the signal from the switch 13) is released. After that, when the engine is started, the basic idea of how the lift arm behaves is "rise but not fall." Therefore, if the engine is immediately stopped (power off) with the switch 13 in the raised state, the engine cannot be started with the PTO switch still on, and the work machine will be lowered even if the engine is restarted and the switch 13 is lowered. First, the position dial cannot move unless the position dial is brought to the stop position.

Further, even if the operator tries to lower the working machine by the lift arm upper limit dial after the engine is stopped while the switch 13 is in the raised state, the working machine cannot be lowered, and in order to lower the working machine, the position dial must be brought after the engine is restarted. In addition,
The working machine may be a ditcher or the like in addition to the rotary.

[0026]

The present invention is as described above, and when lowering the lifted work implement, the PTO system clutch is driven and the lowering speed is set so that the PTO shaft attains the target rotation before the working unit enters the soil. By adjusting, it is possible to reduce the impact resistance in the initial stage of driving and reduce the unworked portion.

[Brief description of drawings]

FIG. 1A shows a flow chart of the present invention,
(B) is an overall operation side view.

FIG. 2 is a configuration diagram of a hydraulic control system.

FIG. 3 is a block dialgram for hydraulic control and PTO control.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Traveling power vehicle 2 Link mounting device 3 Working machine 3A Working part 4 Lift arm 5 Hydraulic device 8 PTO system clutch 10 PTO shaft 13 Control valve switch 14 Control valve 22 PTO system switch 30 Safety circuit 31 Control circuit

Claims (1)

[Claims] 1. A hydraulic device (5) having a lift arm (4) which is moved up and down via a control valve (14) which is switched up and down by a signal of an operation of an artificial switch (13), and is turned on by an artificial operation. P interlocking with the PTO clutch (8) that is turned off
A working unit (3) operatively connected to the PTO shaft (10) is connected to a traveling power vehicle (1) having a TO shaft (10).
A working machine (3) having (A) is mounted to be movable up and down via a link mounting device (2), and the working machine (3) lifted by the lift arm (4).
A working machine lifting control device comprising: a descent speed control circuit (31) for turning on the PTO system clutch (8) and lowering the PTO shaft (10) to a target rotation in the process of descending.