JPS5826928B2 - ground work equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a work mode in which a ground work device attached to a machine body so as to be able to be driven up and down is automatically raised and lowered based on an automatic lift control command, and a work in which a ground work device is lifted and lowered based on a manual lift command. The present invention relates to a ground work machine that has a work mode switching mechanism that switches between the two modes, and also has a forced lift operation mechanism that can transmit a forced lift command to the lift mechanism of the ground work machine in the automatic control operating state.

This ground work equipment can automatically maintain the ground action depth within a set range by switching to a work mode based on automatic elevation control commands, and can stabilize the work load while maintaining the ground work equipment. If you switch to a work mode based on manual lifting commands, you can raise or lower the ground work equipment to a desired height, and furthermore, you can perform work based on automatic lifting control commands. Even in this mode, the ground work equipment can be forcibly raised by operating the forced lift operation mechanism, so when turning around at the end of the stroke, etc., the ground work equipment can be easily pulled out of the ground and lifted to the ground using ge. It is possible to switch to

In addition, in this ground work machine, when the engine is started, if the work mode switching mechanism is set to the work mode that automatically lifts and lowers the control, the ground work equipment automatically switches to the automatic lift control command as soon as the engine is started. There was a risk that this could lead to a dangerous situation where the vehicle would unexpectedly descend.

Incidentally, this type of problem similarly occurs when switching from a work style based on manual lifting/lowering commands to a working style based on automatic lifting/lowering control.

The present invention aims to solve the above problems and improve safety.

Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 1 shows a ground working machine in which a rotary tilling device 1 as a ground working device is attached to the rear of a tractor 2 so as to be able to rise and fall freely. , is configured to drive the rotary tiller 1 and a hydraulic pump (not shown) that drives the single-acting hydraulic cylinder 5 for raising and lowering the rotary tiller 1.

The tilling device 1 is suspended and supported by a lifting arm 6 that is interlocked with the hydraulic cylinder 5, and is driven up and down by controlling the electromagnetic control valve of the hydraulic cylinder 5 as described above. It is structured as follows.

Next, a mechanism for automatically controlling the raising and lowering of the tilling device 1 will be explained with reference to the block diagram shown in FIG. 2.

That is, the detector 1 detects the actual rotational speed of the engine 3.
and signal A from the rotation speed setter 8, which sets the maximum engine rotation speed according to the accelerator setting, are applied to the first subtractor 9, and the engine load is reduced by the amount of decrease in engine rotation speed A - It is configured to be detected as E.

Further, a signal from the first subtractor 9 and a signal H from a plowing depth setting device 10 for adjusting the relative level of the tilling device 1 with respect to the tractor 2 to change the target plowing depth are applied to the adder 11. At the same time, the output signal from the adder 11 and the signal from a level detector 12 that detects the relative level of the tiller 1 with respect to the tractor 2 are applied to the second subtractor 13.

Then, the signal from the second subtractor 13 is transmitted to the first subtractor 13. The information is transmitted to the second discriminators 14 and 15, and the first and second discriminators 1
4 and 15, the ascending valve 16 and descending valve 17 of the hydraulic cylinder 5 are opened as described later.

. Further, an operation panel 24 of the control section is provided between the adder 11 and the second subtractor 13, between the level detector 12 and the second subtractor 13, and between the power supply V and the valves 16 and 17. An interlocking switch 22a that is operated by one rotary operating tool 22 provided in the.

22b and 22c are interposed, and this switch 22a
As the tilling device 1 is switched, as described below, the tilling device 1
It is configured to be controlled for lifting and lowering by force.

That is, when the switch 22a is connected to the R contact point, the structure is such that automatic elevation control is performed so as to approach the target setting plowing depth based on the detection result of the engine load (work load).

First, the signal voltage A-E from the first subtractor 9 increases as the engine speed decreases, and the signal voltages H and L from the plowing depth setter 10 and level detector 12 increase as the plowing depth increases. If the tilling device 1 is located shallower than the set plowing depth position while the engine rotation speed is decreasing, the rotation speed decrease amount (engine load)
A-E>0 and deviation amount H-L from the set tilling depth of the tilling device 1 (
If they are equal to 0, the output voltage from the second subtractor 13 becomes zero, and it is determined that the tilling device 1 does not need to be raised or lowered.If the engine speed reduction amount A-E increases from this state, the second subtractor 13 The first discriminator 14 determines that the tilling device 1 needs to be raised because the output voltage becomes positive, and conversely, when the engine speed reduction amount A-E decreases, the second subtractor 13 determines that the tiller 1 needs to be raised. The output voltage becomes negative, and the second discriminator 15 determines that the tilling device 1 needs to be lowered.

Then, the raising and lowering of the tilling device 1 is controlled so that a balanced relationship is established based on the change in the amount of reduction in engine rotational speed and the change in the signal from the level detector 12 as the tilling device 1 is raised and lowered.

In other words, if the output voltage from the second subtractor 13 is positive,
The lifting valve 16 of the hydraulic cylinder 5 is opened to drive the lift arm 6 to swing upward, and conversely, when the output voltage is negative, the hydraulic cylinder 5 is opened so that the lift arm 6 and the tilling device 1 are automatically lowered. It is configured to open the descending valve 11.

Furthermore, if the switch 22a is connected to the contact P, a mode is realized in which automatic elevation control is performed so that the deviation between the target height and the actual height of the tractor 1 is equal to the deviation.

1. Signal H from plowing depth setting device 10 and level detector 1
The second subtractor 13 subtracts and compares only the signals from the second subtractor 13, and the tilling device 1 is controlled to move up and down based on the result.

That is, the tilling device 1 is configured to be automatically controlled to move up and down to a height set by the setting device 10 and then stopped.

Further, when the switch 22a is connected to the contact M, the second
All inputs to the subtractor 13 are cut off, automatic control is canceled, and the lifting valves 16 and 17 are activated only by operating the respective changeover switches 23.

This switch 23 is disposed on the front panel 24 of the control section together with the tilling depth setting device 10.
The tilling device 1 is configured to be able to be moved up and down as desired and fixed in accordance with the switching direction of No. 3 and the operating time thereof.

Further, this automatic control mechanism incorporates a forced lift mechanism described below.

That is, a switch 19 is provided in the output circuit of the plowing depth setting device 10, which can be switched and connected to the setting device 18 to which a sufficiently large positive constant signal is set. By inputting the fixed signal from the setter 18 to the adder 11 instead of the signal 11 of 10, the output from the second subtracter 13 can be made positive, and the tilling device 1 can be operated upward even during automatic control. I can,
Further, the configuration is such that the control can be returned to the above-mentioned state again by returning the switch 19 to its original state.

1. This switch 19 is configured as a manual operation mechanism for pulling out the tilling device 1 from underground when turning the machine during automatically controlled tilling work, and returning it to automatically controlled tilling work after turning. -ing

This switch 19 is operated by a snap lever 21 provided on the column of the steering bundle 20.

Further, the switch 22a is included in the automatic elevation control mechanism.
is connected to P or R, in other words, when the engine 3 is started or the switch 22a is switched from M to P or R, the control command is issued. Since there is a possibility that the tilling device 1 may unexpectedly descend due to the above, the following safety mechanism has been incorporated in order to eliminate this possibility.

That is, between the first and second discriminators 14, 15 and the second subtractor 13, the signal from the second subtractor 13 is transmitted to the first and second discriminators 14, 15 and the second subtractor 13.
A locking mechanism 25 is provided that prevents the signal from being transmitted to the second discriminators 14, 15 and disables automatic lifting/lowering operation.

This locking mechanism 25 operates when the switch 22c is connected to the contact M, or when the comparator 26 that compares the signal from the speed detector 1 and the signal set in the setting device 26a is connected to the engine rotation speed. When at least one of the states in which it is comparatively detected that the speed is not higher than a certain level appears, the lock is activated, and the switch 19 is connected to the setting device 18. A state in which the comparator 26 compares and detects that the engine rotation speed is in a high speed state above a certain level, and the switch 22
When all states in which c is connected to P or R are manifested, the state is switched to the unlocked state.

According to the above configuration, even when the engine 3 is started, the switch 19 is connected to the setting device 18 by the action of the lock mechanism 25, the switch 22a is connected to the contact P or R, and the engine rotational speed is kept at a constant speed. Until the above conditions are met, it is impossible to lower the tiller 1 based on the automatic elevation control command, and only when these conditions are satisfied, the locking mechanism 2
5 is in the released state, and the switch 19 is set to the plowing depth setting device 10.
If connected to the , automatic control will be performed as specified.

In summary, the ground work machine according to the present invention has the above-mentioned structure, when the work mode switching mechanism 75 is not switched to the flip control operating state, or when the rotation speed of the engine installed in the machine is below a certain set rotation speed. If at least one of the certain conditions is detected, a locking mechanism is provided that disables the operation of the lifting mechanism based on the automatic lifting control command, and the working mode is in the automatic control operating state and the engine is set to the certain setting. It is characterized in that it is configured to release the lock when it is in an operating state of rotation or higher and a forced lift command is issued from the manual operation mechanism 19.

In other words, the action of the lock mechanism prevents the ground work equipment from unexpectedly lowering when the engine is started, and also locks the operating state of whether the engine rotation speed is below or above a certain set rotation speed. This is in addition to one of the requirements for activating and disengaging the mechanism, so that during the early stages of engine startup, when the engine has not yet reached a certain set rotation speed that can withstand the work load, the ground handling equipment may be unexpectedly activated. When the vehicle descends, the load will not suddenly increase due to ground resistance and cause the engine to stop, and the forcible ascent operation mechanism must issue a forced ascent command as a requirement for unlocking. It is possible to further improve safety by doubly preventing the ground work equipment from descending rapidly just by starting the engine even though the worker has no intention of carrying out serious work. It has become.

[Brief explanation of the drawing]

The drawings show an embodiment of the ground working machine according to the present invention, with FIG. 1 being a side view and FIG. 2 being a block diagram. 1...Ground work device, 2...This machine, 3
... Engine, 5 ... Lifting mechanism, 19
......Manual operation mechanism, 22a...Working mode switching mechanism, 25...Lock mechanism.

Claims (1)

[Claims] 1 Ground work device 1 attached to the aircraft body 2 so that it can be raised and lowered by one drive
It has a work mode switching mechanism 22a that switches between a work mode in which the ground work device 1 is automatically raised and lowered based on an automatic lifting control command and a work style in which it is raised and lowered based on a manual lift command, and in the automatic control work mode, the lifting and lowering of the ground work device 1 is performed. Forced lift operation mechanism 19 capable of transmitting a forced lift command to the mechanism 5
In the ground work machine having the following, at least one of the state in which the work mode switching mechanism 22a75 is not switched to the flicking control operating state or the state in which the rotational speed of the engine 3 mounted on the machine is below a certain set rotation is detected. In this case, a locking mechanism 25 is provided to disable the operation of the lifting mechanism 5 based on the automatic lifting control command, and the working mode is in the automatic control operating state and the engine 3 is in an operating state at or above the certain set rotation speed. 2. A ground-based working machine characterized in that the above-mentioned lock is released when a forced-lift command is issued from the forced-lift operation mechanism 19.