JPH0749674B2 - Work vehicle operating structure - Google Patents

Description

TECHNICAL FIELD The present invention relates to an operating structure for a work vehicle provided with an electromagnetic control valve for operating a hydraulic actuator.

[Prior Art] When a clogging of dust occurs in an electromagnetic control valve, it is difficult to clear the clogging by itself because it is difficult to clear the clogging by itself due to insufficient power with only the switching operation force that appears in the operating section. Of. Therefore, in the above-mentioned work vehicle, conventionally,
If the control valve is clogged with dust, and the hydraulic actuator does not stop because the control valve does not switch according to the signal even when the stop operation is performed and the neutral switching signal is output, the operator may By recognizing the trouble and stopping the operation of the engine to stop the drive of the hydraulic pump, the hydraulic actuator can be stopped.

[Problems to be Solved by the Invention]

Conventionally, it takes time to recognize the occurrence of trouble and stop operation,
The operation target device driven by the hydraulic actuator may move to the stroke end, or the operation target device may be an infinite rotating device with no operation limit such as a swivel base and may move a large stroke. .

An object of the present invention is to provide a work vehicle in which troubles due to poor switching of control valves can be easily avoided.

[Means for Solving the Problems]

In the operating structure of the work vehicle according to the present invention, in order to achieve the object, an operation sensor for detecting the operation of the hydraulic actuator, and a signal output when the neutral switching signal of the electromagnetic control valve of the hydraulic actuator is output. A measuring means for automatically measuring the elapsed time from the time is provided, and when the operation sensor is in the detection state when the elapsed time measured by the measuring means reaches the set elapsed time, the pressure oil is automatically supplied to the hydraulic actuator. There is an automatic emergency stop means to disable it. The action and effect are as follows.

[Action]

The set elapsed time is set so that there is no problem in terms of safety even if it is set as the time it takes to stop the hydraulic actuator after the neutral switching signal is output. Then, when the stop operation is performed and the neutral switching signal is output, the electromagnetic emergency stop means does not operate and the electromagnetic emergency stop means does not operate in the normal state in which the electromagnetic control valve switches to the neutral state before the set elapsed time accordingly. The actuator can be operated as desired by the control valve. When the control valve does not switch to the neutral state even though the neutral switching signal is output after the stop operation, even if the control valve remains in the pressure oil supply state due to switching failure, When the set elapsed time has elapsed from the signal output, the automatic emergency stop means automatically disables the pressure oil supply based on the information from the measuring means, and the drive of the hydraulic actuator is automatically stopped.

〔The invention's effect〕

Even if the electromagnetic control valve switching failure occurs due to the operation signal,
Since the hydraulic oil supply is disabled by the automatic emergency stop means, the driving of the hydraulic actuator is stopped, and the operation target device is stopped early so as not to be too late.

〔Example〕

 Next, examples will be shown.

As shown in FIG. 2, a swivel base (2) is attached to a crawler type traveling machine base having a dozer (1), and the swivel base (2) is provided with a driving part (3) and a control part (4). A swing bracket (6) is attached together with it to form a backhoe with a dozer.

In order to enable the operation of the swivel base (2), as shown in FIG. 1, a gear type speed reducing mechanism (8) is attached to the swivel race type swivel operation part (7) attached to the swivel base (2). A hydraulic swing motor (M) is interlocked so as to transmit rotational power through the swing motor (M), and the swing motor (M) is operated by a swing motor operating structure having a swing lever (9) arranged in the control section (4). Is configured.

That is, the control valve (V) of the swing motor (M) is configured as an electromagnetic control valve so as to be switched by the drive circuit (10), and the drive circuit (10) is associated with the swing control means (11). is there. Then, the turning means (11) detects whether or not the turning lever (9) is operated and the operating direction by the potentiometer (12) interlocked with the turning lever (9), and electrically extracts the detection result and outputs it as a detection result. An electric signal for switching the control valve (V) to a corresponding operating state is output to the drive circuit (10). As the drive circuit (10) receives the signal from the turning control means (11), it outputs a drive switching signal and a neutral switching signal to the electromagnetic operating section (13) of the control valve (V) to control the valve (V). Is operated to switch to the left turning side or the right turning side, or to the neutral state.

An automatic emergency stop means (15) is linked to a stop device (14) of an engine (E) that drives a hydraulic pump (P) that supplies pressure oil to a swing motor (M) via a control valve (V), and
The gear (8) is configured to detect the operation of the swing motor (M) based on the rotation of the gear (8a) that constitutes the speed reduction mechanism (8).
The pickup (16) capable of detecting the rotation of (a) and the measuring means (17) linked to the drive circuit (10) are linked to the automatic emergency stop means (15) to turn the swiveling lever (9). The safety is designed so that the drive of the swivel base (2) is automatically stopped in an emergency when the control valve (V) cannot be switched to the neutral state by the operation.

That is, every time the drive circuit (10) outputs a neutral switching signal to the control valve (V), the measuring means (17) automatically outputs the neutral signal based on the information from the drive circuit (10) and the timer means (18). The measurement operation is started, and the elapsed time from the time when the drive circuit (10) outputs the neutral switching signal is measured. Then, when this elapsed time reaches a set elapsed time that is preset as being free from trouble even after the stop operation until the turning motor (M) is stopped, at this time, the automatic emergency stop means (15) is activated. It is determined whether the pickup (16) is in the detection state or the non-detection state, and when it is determined that the pickup (16) is in the non-detection state, the stop device (14) is maintained in the non-operation state to continue the engine operation. This enables the pressure oil to be supplied by the hydraulic pump (P) when the drive of the control valve (V) is switched next time, and automatically when the engine (E) is determined to be in the detection state.
The stop motor (14) is operated to stop the drive of the hydraulic pump (P) so that the swing motor (M) stops even if the control valve (V) is in the pressure oil supply state. As described above, the pressure oil supply thereto is disabled.

[Another embodiment]

The present invention can be applied to an operation structure using a boom cylinder, an arm cylinder, or a bucket cylinder as an operation target actuator in addition to the swing motor (M), and further to various work vehicles other than the backhoe, such as a crane. And
Instead of the pickup (16), a detection means that acts on the operation target device driven by the hydraulic motor, the hydraulic cylinder, or these actuators may be adopted. Therefore, the swing motor (M) is simply replaced by the hydraulic actuator (M).
And the pickup (16) is referred to as an operation sensor (16).

Also, instead of stopping the engine, by disengaging the clutch provided between the engine and the hydraulic pump, or by adopting a means for opening the emergency oil drain passage provided between the hydraulic pump and the hydraulic actuator, You may implement and implement so that supply failure can be revealed.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

The drawings show an embodiment of the operating structure of a work vehicle according to the present invention,
FIG. 1 is a block diagram of a turning control system, and FIG. 2 is a side view of the entire backhoe with a dozer. (15) …… Automatic emergency stop means, (16) …… Actuation sensor,
(17) …… Measuring means, (M) …… Hydraulic actuator,
(V) ... Electromagnetic control valve.

Claims (1)

[Claims] 1. An operation sensor (16) for detecting an operation of a hydraulic actuator (M), and a signal output from a neutral switching signal of an electromagnetic control valve (V) of the hydraulic actuator (M). Is provided with a measuring means (17) for automatically measuring the elapsed time, and when the operation sensor (16) is in the detection state when the elapsed time measured by the measuring means (17) reaches a set elapsed time, A work vehicle operating structure provided with automatic emergency stop means (15) for automatically disabling pressure oil supply to an actuator (M).