JPS5826926B2 - Safety equipment for ground-based work equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention operates a ground work device mounted on an aircraft body using the power of an engine mounted on the aircraft based on control detection results such as the height detection result of the work device relative to the aircraft body and the work load detection result. The present invention relates to a ground-based working machine that is equipped with a control mechanism for controlling the lifting drive and a mechanism for manually switching between the control operating state and the lifting neutral state in which the control is released.

The above-mentioned ground-based work equipment with an automatic control mechanism was developed to automatically raise and lower the ground-based work equipment to a desired height relative to the machine body, and to stabilize it at a predetermined load state. If the switching mechanism is mistakenly switched to the control state when the engine is started, the control mechanism will operate at the same time as the engine starts, and the ground work equipment that has been lifted will be unexpectedly controlled to descend. There was a risk.

In order to solve this problem, it is possible to consider a method that disables the engine from starting when the switching mechanism is in the controlled state, but if this is done, various causes of the inability to start the engine must be checked. It was an unavoidable annoyance.

For example, if the electric circuit of the starter is cut off to make it impossible to start, a similar phenomenon will occur due to over-discharge of the battery or disconnection of the starter circuit.

SUMMARY OF THE INVENTION Therefore, the present invention is intended to solve the above-mentioned problem caused by this, while making it possible to start the engine even when the switching mechanism is in the control-released state.

Embodiments of the present invention will be described in detail below based on illustrative 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 that it can be raised and lowered, and the rear propulsion wheels 4, 4 and the tilling device are powered by an engine 3 mounted on the tractor 2. 1 and also drives a hydraulic pump (not shown), and is operated by a hydraulic control pulp (described later) which is appropriately switched and activated by an electric control signal, and a single-acting hydraulic cylinder serves as a lifting mechanism for the tilling device 1. 5 is telescopically operated to vertically swing a lift arm 6 connected to the cylinder 5, thereby driving the tilling device 1 suspended and supported by the lift arm 6 up and down.

The hydraulic cylinder 5 is configured to be automatically controlled based on changes in the load of the engine 3 and changes in the relative height of the tilling device 1 with respect to the tractor 2, the details of which will be explained in the block diagram of FIG. 2. .

A signal E from a detector 7 that detects the actual rotational speed of the engine 3 and a signal A from a rotational speed setter 8 that sets a reference engine rotational speed are applied to a first subtractor 9 to reduce the engine load to the engine. The configuration is such that the amount of decrease in rotational speed is detected as A-E.

Further, the signals A-E from the first subtractor 9 and the tilling device 1
The signal H from the plowing depth setter 10 for changing the target plowing depth by adjusting the relative level with respect to the tractor is sent to the adder 11.
The signal A- from this adder 11 is applied to
A signal from a level detector 12 for detecting the relative level of E+H and the tiller 1 with respect to the tractor 2 is applied to a second subtractor 13, and the respective detection and setting devices ? , 8, 10 and 12, a signal for determining whether to raise or lower the tilling device 1 is taken out from the second subtractor 13 in view of the change in engine load and the set plowing depth value. It is.

First, the signals A-E from the first subtractor 9 increase as the engine speed decreases, and the signals 11 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 reduction amount (engine load) A-E
>0 and the deviation value HL to the set plowing depth of the tilling device 1 (if 0 are equal, the output from the second subtractor 13 becomes zero, and it is determined that the raising and lowering of the tilling device 1 is unnecessary, and this state When the engine speed reduction amount A-E increases from , the output from the second subtractor 13 becomes positive, and it is determined that the tilling device 1 needs to be raised; E
When this decreases, the output from the second subtractor 13 becomes negative, and it is determined that the tilling device 1 needs to be lowered.

The tiller 1 is then adjusted so that the balance relationship is established based on the change in engine speed reduction as the tiller 1 is raised and lowered and the change in the signal from the level detector 12.
Elevation control is performed.

When the output from the second subtractor 13 is positive, this is determined by the discriminator 14, and the lifting pulp 15 of the hydraulic cylinder 5 is opened so as to drive the lift arm 6 in one upward swing. On the other hand, if the output is negative, this is determined by the discriminator 16, and the lowering valve 17 of the hydraulic cylinder 5 is opened so that the lift arm 6 and the tilling device 1 are lowered.

Further, interlocking switches (switching mechanisms) 18a and 18b for switching the control mode are arranged in the input circuit to the second subtractor 13, and are switched to the contact R, respectively, as shown in the figure, so that the above-mentioned control mode is maintained. dripping

Then, when the contacts P are switched, signals 11 . Only L is input to the second subtractor 13, and the lift control is performed based on the calculation results of both.

In other words, control is performed to raise and lower the tilling device 1 to the height determined by the tilling depth setting device 10 regardless of the work load.

Furthermore, when the contacts Q are switched, all input to the second subtractor 13 is cut off, and automatic control is canceled.

In this state, the changeover switch 18a. Another changeover switch 18c linked to switch 18b turns on the power to a manual lift switch 19 that selectively operates the lifting and lowering valves 15 and 17, and by operating this switch 19, the tilling device 1 can be raised or lowered as desired. And it will be in a neutral fixed state.

Furthermore, the present invention incorporates the following safety devices.

First, it is configured to detect, via a differential circuit 21, that the starter 20 of the engine 3 is activated;
A safety lock circuit 22 that operates using the signal from the differential circuit 21 as a set signal is connected, and is configured to block the signal from the second subtractor 13 with the output signal from the safety lock circuit 22. .

Further, this safety lock circuit 22 is configured to be reset by a signal from a differential circuit 23 that detects that each of the changeover switches 18c is switched to the contact point Q.

That is, the changeover switches 18a, 18b and 18
Starter 2 with c switched to contact R or P
0 is activated and the engine 3 is started, the second subtractor 1
Even if the lift control signal is output from 3, the safety lock circuit 22
The valves 15 and 17 are not activated by the operation of , and the safety lock circuit 22 is reset when the changeover switches 18a, 18b, and 18c are switched to the contact Q, but at this time, unless the switch 19 is operated, the pulp 15,17
will never operate.

Then, the changeover switch 18 a t 18 b
, 18c to contact R or P, each of the above-mentioned lifting and lowering controls can be performed respectively.

Note that it is also possible to use a key switch 24 in place of the starter 20, and in this case, in order to confirm that the engine 3 has been started, an engine rotation speed detector 25 [detector] can be used as shown in FIG. 7] and the starting rotation speed setter 26 are compared with the comparator 27, and the engine 3
is started, and the changeover switches 18a, 18b, 18
It is preferable that the differential circuit 23 is activated to reset the safety lock circuit 22 only when the contact point Q is switched to the point c.

As described above in detail in the embodiments, the present invention provides switching mechanisms 18a and 1 for switching the control mechanism between the control operating state and the non-operating state.
When 8b and 18c are in the controlled operating state, the engine 3
When a starting operation is performed, a safety lock circuit 22 that prevents the control detection result from being input to the control mechanism is configured to be activated. Since it is configured to be reset by switching to the state, it goes without saying that the lifting control is performed immediately after the engine 3 is started, and there is no danger of the ground work device 1 being raised or lowered unexpectedly. Since this is possible in any case, it is possible to immediately start working in the desired configuration by operating the switching mechanism 18a, making it possible to improve safety and work efficiency all at once.

[Brief explanation of drawings]

The drawings illustrate an embodiment of the safety device for a ground-based work machine according to the present invention, in which Fig. 1 is a side view of a riding tiller, Fig. 2 is a block diagram of the control mechanism, and Fig. 3 is another embodiment. FIG. 1...Ground work device, 3...Engine, 18a. 18 b, 18 c... switching mechanism, 22.
...Safety lock circuit.

Claims (1)

[Scope of Claims] 1. Ground work equipment 1 mounted on the aircraft body is powered by the aircraft engine 3 based on control detection results such as the height detection result of the work equipment 1 relative to the aircraft body and the work load detection result. A mechanism 18a that is equipped with a control mechanism for controlling the lifting drive and artificially switches between the control operating state and the lifting neutral state in which the control is released. In a ground work machine equipped with 18 b t 18 c,
When the engine 3 is started while the switching mechanisms 18a, 18b, and 18c are in the control operating state, a safety lock circuit 22 is configured to be activated to prevent the control detection result from being input to the control mechanism. , and this safety lock circuit 22 has a switching mechanism 18 a , 1
8b t 18 c A safety device for a ground-based work machine, characterized in that the device is configured to be reset by switching to a vertically neutral state.