JP2946877B2 - Safety equipment for construction machinery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for automatically stopping a vehicle-based construction machine when the presence of an obstacle in the operation range of the vehicle-based construction machine is detected by a detection device mounted on the machine. The present invention relates to a safety device which is activated and automatically releases an operation stopping means when the obstacle is no longer present.

[0002]

2. Description of the Related Art When an obstacle enters a work area or a restricted area of a vehicle-based construction machine, a driver recognizes the obstacle and stops the driving operation. Means for stopping have been proposed in the past, as a method of detecting the presence of the obstacle by detecting a probe signal transmitter attached to the machine and a reflected wave of the signal from the obstacle. The transmitter is detected by a reflected wave detector, or the transmitter is attached to an obstacle itself, for example, a moving body such as a worker, and the obstacle signal from the transmitter is detected by a receiver mounted on the machine. ,
When such obstacles are within the danger range, there has been a method of automatically stopping the engine of the machine or disabling the operation of the operation lever for operating each part.

[0003] For example, FIG. 3 shows an example belonging to the latter, in which the mobile obstacle in the figure is a worker 21, 22 is a transmitter attached to the head, 23
Is a bulldozer as a typical example of a vehicle-based construction machine, to which transmitters 24, 24,... Are attached. FIG. 4 is a block diagram showing the engine stop means, showing a state in which the fuel cut solenoid 25 is energized. The solenoid 25 is a start switch 26 and a normally closed contact 28a of a relay 27.
And is connected to the positive electrode of the power supply 29 via the. Receiver 24
Is connected to the controller 30, and the controller 3
The output side of 0 is connected to the relay coil 28b of the relay 27.

With the above configuration, when the start switch 26 is turned on, the current of the power supply 29 is supplied to the solenoid 25 through the start switch 26 and the normally closed contact 28a of the relay 27. When the solenoid 25 is energized, the fuel governor is set free via a fuel control linkage (not shown), and the fuel flows from the fuel injection pump to the engine. When the worker 21 shown in FIG. 3 is in the vicinity of the bulldozer 23 in such a state, the receiver 24 receives a signal transmitted from the transmitter 22 carried by the worker 21, and the signal of the receiver 24 is transmitted to the controller 30. Is amplified and
The relay coil 28b of the relay 27 is energized, and as a result, the normally closed contact 28a is turned off, no current flows through the solenoid 25, no fuel flows from the fuel injection pump, and the engine stops. In the prior art shown in the above example, when the receiver 24 detects the presence of an obstacle and issues a signal, the controller 30 serves to stop the engine, so that the bulldozer 23 operates the operation lever 20 of the operation lever 20. Irrespective of the presence or absence of the vehicle, the traveling and the operation of the working device are both stopped.

[0005]

As described above, the stopping device is operated to stop all or a part of the operation of the machine,
Conventionally, a method similar to this example has been proposed for preventing accidents and disasters beforehand. However, when work is resumed after this stoppage, it is automatically detected that there is no danger at all. No method has been proposed for canceling the suspension state. There are some differences in the release of the suspension state depending on the type of construction equipment,
Generally, there are the following stop condition release conditions and problems at that time. That is,

[0006] As a first condition, while an obstacle is present in an operating range or a restricted area of the machine, the operation stop state is continuously maintained, but an obstacle in the range exists. In the case of a system in which the operation stop state is released when it disappears, if the driver sets the operation lever at the time of the release, the corresponding portion of the machine is suddenly operated, which is not preferable.

As a second condition, when the operation is stopped by a signal from the obstacle detecting means, the system determines that the driver is safe and can forcibly cancel the stop signal by operating a switch. In the case of, when there are a plurality of obstacles in the operation range and the no-go area and the driver exceeds the limit that can be confirmed by the driver, the operation is restarted with the unconfirmed obstacles existing. It is not safe because there is a possibility.

Next, as a third condition, the operation of the apparatus is stopped and the operation stop state is maintained, and when this state is released, the switch is operated by the driver each time. However, if there is an obstacle in the operation range or restricted area, the release will be invalidated, and in the case of a system where the operation stop state is maintained, there is no danger at all regardless of the operation of the operation lever, It is necessary to operate the switch again and again, and the operation becomes complicated and diverse. In the prior art illustrated in FIGS. 3 and 4 as one of the systems, every time an obstacle is sensed, the engine is stopped, and the start switch must be operated without fail to return. An object of the present invention is to release a stop state in consideration of all of these points, and to automatically obtain a condition under which safe work can be resumed after the release.

[0009]

In order to solve the above problems, the present invention takes the following measures. That is, a detector that transmits an exploration signal from a vehicle-based construction machine and senses a reflected wave from an obstacle within a predetermined range, or a detector that detects a signal from the obstacle as described above. Obstacle detecting means for detecting an obstacle signal and outputting a neutral signal when one or more operating levers for machine operation are in a neutral position; and A control signal is output when input, but the input of the obstacle signal disappears, and the controller stops outputting the control signal when the neutral signal is input. There is provided an operation stop means for invalidating one or a plurality of operation lever operation acts, but automatically canceling the operation lever invalidation action when the control signal disappears.

If an obstacle is present in the operating range or in the off-limits range when the vehicle-based construction machine is operating, an obstacle signal is input to the controller, and the controller sends a control signal to the operation stopping means. Is entered,
The operation of all control levers becomes invalid, and the operation of the machine, including movement and work, stops. At this time, all of the operation levers are returned to neutral, and when an obstacle is removed from the operation or restricted area, the control signal from the controller is not input to the operation stop means. Is automatically released and can be freely operated by the operation lever. Even if the obstacle is removed, all the operation levers are in the neutral position at that time,
The control signal does not disappear unless a neutral signal is input to the controller.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an example in which the present invention is applied to a fully hydraulic vehicle construction machine. Then, a system in which switching control of the hydraulic system is performed by pilot hydraulic pressure from a remote control valve will be described. In the figures, reference numerals 6, 7, 8, and 9 denote remote control valves for switching hydraulic switching valves (both not shown) for distributing hydraulic oil to hydraulic actuators for traveling and working device operation, respectively. By operating the operation levers of the respective pilot lines 14, 14, 14,.
・ ・ Generate pilot pressure at. 15, 15, 15,
... are the remote control valves 6, 7, 8, 9
And selectively extracts the higher effective pilot pressure from the pilot pressure oil supplied to each of the two pilot lines 14, and the neutral detection means 1
Shuttle valve that leads to

The neutral detecting means detects the presence or absence of pilot pressure oil from each pilot line and, when no pilot pressure is generated in all the lines, functions to input a neutral signal to the controller. Thus, for example, a conventional technology in which a pressure switch provided at a terminal of a pilot pipeline from each shuttle valve 15 and a power supply are connected in series may be used. Reference numerals 10, 11, 12, and 13 denote detectors provided on the outer periphery of the fuselage and provided in a direction in which an obstacle may be present, which detects an obstacle and outputs a signal corresponding thereto. In the case of a single machine, in the case of a plurality of machines, the number is increased or decreased according to the form, operating condition, and work environment of the machine. When an obstacle detection signal is input from at least one of the one or a plurality of the detectors, the obstacle detection means 2 controls the controller 3.
An obstacle signal is output toward.

Reference numerals 4 and 5 denote operation stopping means, which stop the operation of the machine only while the control signal is being input, but have a function of automatically returning to the original state when the input disappears. For example, when a control signal is input to the operation stopping means 4, the pipeline to the traveling hydraulic actuator is closed and its operation is stopped. However, when the signal disappears, the operation returns or the operation stopping means 5 Once entered,
Stops all or part of the operation of the work equipment, or only one direction, and automatically returns when the signal disappears, or disables the operation lever for each of the above operations. There are various embodiments of the deactivation means depending on the operation.

Further, as described above, the controller 3 guides the neutral signal from the neutral detecting means 1 and the obstacle signal from the obstacle detecting means 2 each time. As shown in the flowchart of FIG. 2, as long as the obstacle signal is input, the operation stopping means 4 and 5 output the control signal, and unless the neutral signal from the neutral detecting means 1 is input. Even if the input of the obstacle signal disappears, the control signal is continuously output.

As is apparent from the above description of the configuration and functions, when the detector in the embodiment of the present invention detects an obstacle, the operation stopping means is activated to stop the operation of the machine, but the operation lever or the like is operated. Unless all of the operation systems are set to the neutral position, the function of the operation stopping means does not automatically return. Therefore, the first condition, the second condition, and the third condition described in the above-mentioned problem to be solved by the invention are not described. All of the problems under the above condition are satisfied, and the machine operation can be resumed only when the obstacle signal is not output and the levers of the operation system are neutral. In the above embodiment, the method of detecting the presence or absence of the pilot oil pressure is used as the neutral detecting means 1. Of course, the neutral operating position may be detected by mechanical or electrical means. In addition to the method of disabling the pilot oil pressure for operation as the operation stopping means 4 and 5, the main circuit pressure oil as the power transmission medium is opened and closed, and the power connection / disconnection mechanism of the mechanical transmission system is operated. This is of course also included.

[0016]

When the safety device according to the present invention is installed in a vehicle-based construction machine, if an obstacle is present in a predetermined range, such as within the operating range of the working device or within a restricted area during machine operation, An obstacle signal is input to the controller by the obstacle detecting means, and the controller outputs a control signal to the operation stopping means, so that all operations of the machine are stopped. Then, if the obstacle signal disappears and the neutral signal is input to the controller, the control signal is not output, the function of the operation stopping means is automatically released, and the original operation is enabled. Therefore, if the obstacle is removed while the driver is operating the operating lever, the operation will not be suddenly resumed, and the operation will not be suddenly resumed. A safety device that will not cause an accident due to unexpected operation and that will not cause harm from overlooking the driver when multiple obstacles enter, and all automatically Since the operation is stopped and released, the operation is easy and safe without requiring any special attention or operation.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of a configuration of a safety device according to the present invention.

FIG. 2 is a flowchart showing functions of a controller according to the present invention.

FIG. 3 is a side view illustrating an operation of a safety device of the related art mounted on a bulldozer.

FIG. 4 is a block diagram showing an operation of the safety device in FIG. 3;

[Description of Signs] 1 Neutral detecting means 2 Obstacle detecting means 3 Controller 4, 5 Operation stopping means 10, 11, 12, 13 Detector 22 Transmitter 24 Receiver

Claims (1)

(57) [Claims] An obstacle detecting means for detecting an obstacle within a working radius or a restricted area during operation of a vehicle-based construction machine and outputting an obstacle signal, and various operation levers for operating the construction machine are neutral. detects the presence of the position, and a neutral detection means for outputting a respective neutral signal, said obstruction signal
Outputs a control signal when the
When the signal disappears and the neutral signal is in the input state.
A controller for stopping the output of the control signal;
When the signal is input, stop the operation of the machine and
The machine is operating when no control signal is input.
Safety system for a construction machine characterized by having an actuation stopping means to return to.