JP2910355B2 - 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 turning safety device for an upper turning construction machine such as a hydraulic shovel, a working vehicle, and the like.

[0002]

2. Description of the Related Art FIG. 4 is a side view of a hydraulic excavator provided with a safety device according to the prior art. In the figure, 1 is a lower traveling body of a hydraulic shovel, 2 is an upper revolving superstructure, 3 is a revolving motor, 4 is an ultrasonic sensor, and 5 is an alarm which generates an alarm sound (including an alarm light emission). FIG. 5 is a plan view of a main part of FIG. In the figure, reference numeral 6 denotes an operator who works outside the excavator, 7 denotes an ultrasonic sensor disposed on the operator 6, 0 denotes a center of rotation of the upper swing body 2, and R denotes an ultrasonic sensor 4.
, Ie the radius of the sensing area S1. FIG. 6 is a plan view illustrating a sensing area S2 according to another embodiment. The range of the sensing area S2 in a plan view is a fan shape. FIG.
FIG. 2 is a circuit diagram showing an embodiment of a safety device of the related art. In the figure, 8 is a controller, 9 is a swing motor 3
, A pilot switching valve for controlling the swing motor 3, 11 a main pump, 12 an electromagnetic switching valve, 13
Is a solenoid of the electromagnetic switching valve 12, 14 is a turning remote control valve, 15 is an operation lever of the turning remote control valve 14, and 16 is a pilot pump.

A prior art safety device is described with reference to FIGS. During operation of the hydraulic excavator, when the ultrasonic sensor 4 enters the sensing area S1 of the ultrasonic sensor 4, the ultrasonic sensor 4 senses it and outputs a detection signal to the controller 8. The controller 8 makes a determination based on the detection signal and outputs an alarm output to the alarm 5 and the solenoid 13. As a result, the electromagnetic switching valve 12 performs a switching operation and shuts off the pilot circuit of the pilot switching valve 10, so that the upper swing body 2 stops turning. In this case, the excavator generates an alarm sound and stops turning.
The alarm output from the controller 8 may be applied to an engine rotation unit, a pump tilt adjustment unit, and the like (not shown) to generate an alarm sound and limit the turning speed of the upper swing body 2 to a low speed.

[0004]

In the case of a hydraulic shovel, work is often performed by partially turning the upper revolving unit without turning the upper revolving unit. However, when a hydraulic excavator equipped with a safety device according to the related art is working, when the worker 6 enters a position that is within the sensing area S1 but is not dangerous as shown in FIG. 5, the hydraulic excavator turns. It stops. That is, when the hydraulic excavator is performing the work without performing the full swing, the upper swing body unnecessarily stops the swing, so that the working efficiency is very poor. As a countermeasure, even if the sensing area S2 is reduced to a sector shape in plan view as shown in FIG. 6, the sensing area should be reduced in consideration of the turning braking angle under the worst conditions and the response delay of the safety device. Has its limitations and could not be said to be perfect for work efficiency. An object of the present invention is to provide a safety device that can solve the above problems.

[0005]

According to the present invention, a sensing area provided by a sensing sensor provided on a construction machine is divided into a plurality of ranges in plan view, and each of the upper revolving structure and its work attachment is divided into the divided ranges. The range close to the outer peripheral portion is set as the turning stop area, and the range adjacent to the outer periphery of the turning stop area and slightly away from the upper revolving structure and the work attachment is set as the turning low speed area, and When a person or obstacle enters the turning stop area during turning operation, the turning operation of the upper turning body is stopped,
Also, when a person or obstacle enters the turning stop area when the upper revolving unit stops turning, subsequent turning activation is stopped, and when a person or obstacle enters the turning low speed area, the maximum turning speed is limited to a predetermined low speed. I did it. In addition, in the turning pilot circuit that is connected to the turning pilot switching valve by the turning remote control valve, a limit valve that can limit the maximum pressure of the turning pilot secondary pressure derived from the turning remote control valve to a predetermined low pressure is provided. When the sensor detects a person or an obstacle present in the low-speed turning area, the limit valve is actuated via the controller to suppress the maximum pressure of the turning pilot secondary pressure to a predetermined low pressure.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a plan view showing a sensing area S3 in the safety device of the present invention. In the figure, the same reference numerals are given to components using the same components as the conventional technology.
4 'is a sensing sensor attached to the excavator, 17 is a work attachment attached to the front part of the upper swing body 2,
Reference numeral 18 denotes a turning stop area which is a part of the sensing area S3, reference numerals 19L and 19R denote turning low-speed areas which are part of the sensing area S3, and R 'denotes a radius of the sensing area S3. FIG. 2 is a circuit diagram of the safety device of the present invention. In the figure, the same reference numerals are given to components using the same components as the conventional technology. Reference numeral 20 denotes a limiting valve capable of limiting the maximum pressure of the turning pilot secondary pressure to a predetermined low pressure, and reference numeral 21 denotes a solenoid of the limiting valve 20. FIG. 3 is a block diagram showing the function of the controller (8 ').

Next, the configuration of the safety device of the present invention will be described with reference to FIGS. In the safety device of the present invention, the sensing area S3 of the sensing sensor (for example, an ultrasonic sensor capable of transmitting and receiving) 4 'provided on the excavator is divided into a plurality of ranges in a plan view, and the divided range is divided into a plurality of ranges. The upper revolving unit 2 and the work attachment 17 have a range close to the outer peripheral portion of the upper revolving unit 2 and an outer periphery of the revolving stop area 18, respectively.
And a range of a position slightly distant from the work attachment 17 is set in the turning low-speed areas 19L and 19R, and when a person or an obstacle enters the turning stop area 18 when the upper turning body 2 turns, the upper turning body 2 Stop turning operation,
Further, when a person or an obstacle enters the turning stop area 18 when the turning of the upper revolving unit 2 is stopped, the subsequent turning start is stopped, and the person or the obstacle turns into the turning low speed area 19L or 19L.
When entering R, the maximum turning speed is limited to a predetermined low speed. In addition, a limiting valve 2 capable of limiting the maximum pressure of the swirling pilot secondary pressure derived from the swiveling remote control valve 14 to a predetermined low pressure is provided to the swirling pilot circuit that is connected from the swiveling remote control valve 14 to the turning pilot switching valve 10.
0, and when the sensing sensor 4 'detects a person or an obstacle present in the turning low speed area 19L or 19R, the limit valve 20 is operated via the controller 8', and the maximum pressure of the turning pilot secondary pressure is set. At a predetermined low pressure.

Next, the operation of the present invention will be described. When the worker 6 enters the turning stop area 18 in the sensing area S3 during the operation of the hydraulic excavator, the sensing sensor 4 'senses this and outputs a detection signal to the controller 8'. The controller 8 'makes a judgment based on the detection signal and outputs an alarm output to the alarm 5 and the solenoid 13. As a result, the alarm 5 generates an alarm sound, and the electromagnetic switching valve 12 switches from the open oil passage position A to the cutoff oil passage position B, so that the turning of the upper swing body 2 stops.
Note that, in this case, the controller 21 ′ sends the solenoid 21
Is not output, the restriction valve 20 remains at the shutoff oil passage position C. As described above, the hydraulic shovel stops turning when the worker 6 enters the turning stop area 18 close to the upper revolving unit 2 (including the work attachment 17). Alternatively, when an obstacle enters the turning stop area 18, the subsequent turning start is stopped by a command signal from the controller 8 ', which is safe.

Next, during the operation of the hydraulic excavator, when the employee 6 enters the turning low speed area 19L or 19R in the sensing area S3, the sensing sensor 4 'senses it and sends a detection signal to the controller 8'. Output. The controller 8 'makes a judgment based on the above signal, and outputs an alarm output to the alarm 5 and the solenoid 21 of the restriction valve 20. However, in this case, no command signal is output from the controller 8 'to the solenoid 13 of the electromagnetic switching valve 12. Then, the alarm 5 generates an alarm sound, and the restriction valve 20 is switched from the shutoff oil passage position C to the oil passage position d with check valve. Therefore, when the upper operating body 2 is turned by operating the turning operation lever 15 in the direction of the position E or F, the primary pilot pressure from the pilot pump 16 is sent to the turning remote control valve 14. The turning pilot secondary pressure derived from the pilot valve 22L or 22R of the turning remote control valve 14 is controlled by the pilot line 23L or 23R in the pilot circuit and the electromagnetic switching valve 12
Opening oil passage a, pilot line 24L-25L, or 2
It acts on the pilot pressure receiving portion 26L or 26R of the pilot switching valve 10 through 4R-25R. At the same time, the pilot line 24L-25L or 24R-25
A part of the pilot secondary pressure in R flows into the oil tank 28 via the check valve 27L or 27R and the check valve-equipped oil passage position d of the restriction valve 20. Therefore, the maximum pressure of the turning pilot secondary pressure can be suppressed to a predetermined low pressure that can avoid danger. That is, when the excavator is turning and the employee 6 enters the turning low speed area 19L or 19R, the maximum pressure of the turning pilot secondary pressure is suppressed to a predetermined low pressure even if the operating lever 15 is fully tilted. Therefore, the swing speed of the upper swing body 2 (including the work attachment 17) becomes low. The worker 6 recognizes the warning from the warning device 5 and can safely escape to the outside from the turning low speed area 19L or 19R with a margin. In addition, since the turning braking angle of the excavator becomes small, the turning of the excavator can be stopped without contacting the worker even after the worker enters the turning stop area 18. Also, you can work in a wide turning work range,
Work efficiency can be improved.

[0010]

When a hydraulic excavator equipped with a safety device according to the prior art is working without making a full turn, if a worker enters a position that is within the sensing area of the sensing sensor but is not dangerous, Work efficiency was very poor because the upper revolving unit stopped turning unnecessarily. As a countermeasure, even if the sensing area S2 is reduced to a sector shape in plan view as shown in FIG. Has its limitations and could not be said to be perfect for work efficiency. However, in the safety device of the present invention, the sensing area of the sensing sensor is divided into a plurality of ranges in plan view,
Of the divided ranges, the areas close to the outer periphery of the upper revolving structure and the work attachment are respectively located in the turning stop area, and adjacent to the outer periphery of the turning stop area and away from the upper revolving structure and the work attachment. Range was set as the turning low speed area. Accordingly, when a person or an obstacle enters the turning stop area during the turning operation of the upper revolving unit, the alarm is issued by the alarm output from the controller and the electromagnetic switching valve is switched. Stop. Also, when a person or an obstacle enters the turning stop area during the turning operation of the upper turning body, an alarm is issued by a warning output from the controller, and a restriction valve provided in the turning pilot circuit is provided with a check valve-equipped oil. Switch to road position. Therefore, even if the turning operation lever of the excavator is fully tilted, the maximum pressure of the turning pilot secondary pressure is suppressed to a predetermined low pressure, so that the turning speed of the upper turning body is reduced. For example, a worker who is in the turning low-speed area can recognize the warning from the alarm device and retreat outside from the turning low-speed area with a margin. In addition, since the turning braking angle becomes small at a low speed, the turning stop area can be reduced, which is effective. Therefore, in the hydraulic excavator equipped with the safety device of the present invention, unnecessary turning stop is not performed even when a person or an obstacle enters the sensing area, and work can be performed in a wide turning range, thereby improving work efficiency. Can be.

[Brief description of the drawings]

FIG. 1 is a plan view showing a sensing area in a safety device of the present invention.

FIG. 2 is a circuit diagram of the safety device of the present invention.

FIG. 3 is a block diagram illustrating functions of a controller according to the present invention.

FIG. 4 is a side view of a hydraulic excavator provided with a safety device according to the related art.

FIG. 5 is a plan view of a main part of FIG. 4;

FIG. 6 is a plan view showing a sensing area according to another embodiment of the prior art.

FIG. 7 is a circuit diagram showing an embodiment of a safety device according to the related art.

[Explanation of symbols]

 2 Upper revolving unit 4 'Sensor 5 Alarm 6 Worker 8, 8' Controller 10 Pilot switching valve 12 Electromagnetic switching valve 14 Remote control valve for turning 17 Work attachment 18 Turning stop area 19L, 19R Turning low speed area 20 Restriction valve S1, S2, S3 sensing area

Claims (2)

(57) [Claims] 1. A sensing device such as an ultrasonic sensor capable of transmitting and receiving signals is arranged on a construction machine having an upper revolving structure, and when a person or an obstacle enters a sensing area of the sensing sensor,
In a safety device that senses this and stops turning of the upper revolving unit, or limits the turning speed, the sensing area of the sensing sensor is divided into a plurality of ranges in a plan view,
Of the divided ranges, the areas close to the outer periphery of the upper revolving structure and the work attachment are respectively adjacent to the turning stop area and the outer periphery of the turning stop area, and slightly separated from the upper revolving structure and the work attachment. The range of the position is set to the turning low-speed area, the turning operation of the upper revolving unit is stopped when a person or an obstacle enters the turning stop area during the turning operation of the upper revolving unit, and the person is stopped when the turning of the upper revolving unit is stopped. Alternatively, when an obstacle enters the turning stop area, subsequent turning activation is stopped, and when a person or an obstacle enters the turning low speed area, the turning maximum speed is limited to a predetermined low speed. Safety equipment for construction machinery. 2. A turning pilot circuit derived from the turning remote control valve in the safety device for a construction machine according to claim 1, wherein the turning pilot circuit is connected to the turning pilot switching valve from the turning remote control valve. A limiting valve capable of limiting the maximum pressure of the secondary pressure to a predetermined low pressure is provided, and when the sensing sensor detects a person or an obstacle present in the turning low speed area, the limiting valve is actuated via the controller,
A safety device for a construction machine, wherein a maximum pressure of a turning pilot secondary pressure is suppressed to a predetermined low pressure.