JPH0565724A - Safety device of working machine controller - Google Patents

Abstract

PURPOSE:To increase the safety of operation by driving an electro-magnetic proportion valve by an controller for operating an electrical lever manipulating a working machine or operating the output signal of a pedal and this operated signal to actuate the working machine. CONSTITUTION:When a lever lock switch 45 jointed in series to the solenoid 50a of a cut-off-valve 50 is pushed on, the solenoid 50a works to stop feeding the pressurised oil so as not to actuate the operation lever or the operation pedal. And when pushing on an emergent stop switch 44, the lamp 44a is lit and the relay R4 is turned off. And further, the contactor 4 opened to cease to conduct the current to the controller C. And electric current is not fed also to the stop solenoid 49 connected to the governer of engine to prevent the solenoid 49 from stopping at the intermediate position. Accordingly, danger can be rapidly avoided and safety can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for an operating device for an engine or hydraulic equipment such as construction machinery.

[0002]

2. Description of the Related Art Conventionally, for example, during work on a backhoe, when the work is temporarily stopped, it is dangerous to rotate a boom or a swing arm, so that the engine is stopped. Also, in an emergency, an emergency stop switch was provided to stop the engine and stop the work implement.

[0003]

However, although it is possible to turn the key to stop the engine in order to avoid a dangerous state, since the stop motor is used, the operation of the stop motor is completed. There was a time lag of about 1 second until I was mistaken for a failure. Even when not working, if you operate the lever or pedal until the engine stops, the actuator will operate and the boom or arm will rotate, so if you accidentally touch the lever or pedal, it may malfunction. It was in a dangerous state.

[0004]

In order to solve the above problems, the present invention provides a controller for calculating an output signal of an electric lever or pedal for operating a working machine,
In the configuration in which the solenoid proportional valve is driven by the signal calculated by the controller to operate the work machine, when the lever lock switch is turned on, the cutoff valve that stops the supply of pilot pressure to the solenoid proportional valve is operated to operate the lever or The pedal is inoperable. Also, when the emergency stop switch is turned on, the stop solenoid connected to the governor is turned off, the engine is stopped, and the supply of electric power to the controller is stopped.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The problems to be solved by the present invention and the means for solving the problems are as described above. Next, the structure of the embodiments of the backhoe shown in the accompanying drawings will be described. 1 is a control block diagram, and FIG. 2 is a plan view of an operation panel. The backhoe is provided with a swivel base 2 on a crawler type traveling device 1, an engine room 3 is arranged on the rear part of the swivel base 2, an engine E is mounted in the engine room 3, and a cabin is provided in the front part of the engine room 3. A is installed. A controller C is disposed below the seat in the cabin A, and the controller C includes the discrete circuit 5, the angle sensor input circuit 6, the A / D converter 7, the CPU 8, the disconnection check circuit 9, and the expansion output circuit 1.
0, LED drive circuit 11, ROM 12, D / A converter 13, electromagnetic proportional valve drive circuit 14, power cutoff circuit 15,
It is composed of a power supply circuit 16 and a power supply 17.

Touch sensors 4 are provided on the front and upper portions of the cabin A, respectively, and the signals of the touch sensors 4 are input to the discrete circuit 5 in the controller C, and when the working machine contacts the touch sensors 4. The power supply cutoff circuit 15 cuts off the power supply to the solenoid proportional valve drive circuit 14 to stop the expansion and contraction of the hydraulic cylinder that is the actuator. The boom 25 and the arm 26,
Rotation of the bucket 27 and the like, rotation of the swivel base 2, and supply of pressure oil to the hydraulic motor that drives the crawler type traveling device 1 are performed by switching the solenoid proportional valve 23. The electromagnetic proportional valve 23 is provided for each actuator, and the control signal from the controller C is converted into analog by the D / A converter 13 and output to the solenoid of each electromagnetic proportional valve to switch the electromagnetic proportional valve.

Angle sensors 30, 31 and 32 are provided on the rotation bases of the hydraulic cylinders that rotate to rotate the boom 25 and the arm 26 and to offset the arm, respectively. , Angle sensors 33 and 34 for detecting respective turning angles are provided at the bases of the bucket 27, the operation lever for operating the offset and the turn, and the operation pedal, and the A / D converter 7 from the terminal 21 via the input circuit 6. Input to CPU8,
When the boom 25, the arm 26, the bucket 27, and the offset rotate to a dangerous area, the electromagnetic proportional valve 23 is operated to rotate in accordance with the operation amount, and the electromagnetic proportional valve is switched to stop. Only the escape direction can be rotated. In a further dangerous state, the power supply from the discrete circuit 5 to the electromagnetic proportional valve drive circuit 14 is cut off.

An operation panel 20 as shown in FIG. 2 is arranged near the driver's seat, and the position of the bucket 27 is set on the operation panel 20 by inputs from the rotary switch 36 and the angle sensors 30 and 31. LCD 37 for calculating and displaying the excavation depth, switch 39 for selecting whether or not to display it, and lamp 39 that lights up when displayed.
a. A manual switch 3 for operating a working machine (bucket, arm, boom rotation, etc.) when an abnormality is detected
8 and its lamp 38a, a lamp 40 that lights when the boom 25 or the arm 26 enters a dangerous area and stops, a lamp 41 that lights when an abnormality occurs in the controller C,
A switch 42 for selecting the width of the bucket 27 and its ramps 42a and 42b, a switch 43 for setting an offset start height and an automatic offset, and a ramp 4 for indicating the height.
3a, 43b, 43c, an emergency stop switch 44, a lamp 44a that lights when turned on, and a lever lock switch 45 and a lamp 45a that lights when turned on.

The rotary switch 36 is for selecting an operation pattern for adjusting the operation lever to an operation pattern of another maker, and is connected to the controller C so that it can be changed by software. The emergency stop switch 44 is normally closed as shown in FIG.
When the key switch 46 is ON (connected to 46c), the relay R4 is turned ON, the contact r4 is closed, power is supplied to the controller C, and at the same time, the stop solenoid 49 connected to the governor of the engine E is operated. Then, when the emergency stop switch 44 is pressed, the lamp 44a is turned on, the relay R4 is turned off, the contact r4 is opened, the power supply to the controller C is stopped, all controls are stopped, and the solenoid proportional valve is also stopped. The work machine is also stopped, and the power supply for holding the stop solenoid connected to the governor of the engine is stopped to stop the engine.

Further, the lever lock switch 45 is for preventing the operation even if the operation lever or the offset operation pedal of the working machine is operated for the purpose of erroneous operation or safety, and the lever lock switch 45 is a cut-off valve. The cut-off valve 50 is connected in series with the solenoid 50a of 50, and the cut-off valve 50 is expanded and contracted by switching the solenoid proportional valve 23. The solenoid proportional valve 23 operates a solenoid in response to a control signal from the controller C and causes the pilot pressure oil to slide the spool of the solenoid proportional valve 23. The pilot pressure oil is supplied from the hydraulic pump P2 through the cutoff valve 50 and the line filter 52, and the cutoff valve 50 is switched by pressing the lever lock switch 45 to operate the solenoid 50a. Since the supply is stopped and the solenoid proportional valve 23 cannot be switched, it cannot be operated even by operating the operation lever or the offset operation pedal.

Reference numeral 47 in FIG. 3 denotes a work lamp switch. When the work lamp switch 47 is turned on, the work lamp 48 is turned on, and at the same time, the controller C also turns on the light on the operation panel. Reference numeral 53 is an oil pressure switch, which is turned on to turn on the lamp 53a when the pressure oil does not reach a predetermined pressure, and inputs it to the lamp checker 59 to make the buzzer 57 ring.
Reference numeral 54 is a water temperature switch, which is turned on when the temperature of the cooling water becomes equal to or higher than a set temperature and the lamp 54
A is turned on and the buzzer 57 is activated. Reference numeral 55 is a charge indicator, which turns on the lamp 55a and makes the buzzer 57 sound when the voltage drops below a predetermined value.

Further, when the engine E is started, in the winter season, the engine E is cold and difficult to ignite, so the key switch 46 is rotated to the glow position 46a to energize the air heater 56 for a predetermined time. At this time, the relay R3 is turned on, the contact r3 is closed, and the air heater 56 is turned on.
At the same time, the relay R1 is turned on to open the contact r1 and the relay R4 is turned off to open the contact r4, so that the controller C is not supplied with power and is not controlled. The stop solenoid 49 is also not supplied with power to prevent the solenoid from stopping at the intermediate position.

When the key switch 46 is rotated to the position 46b, the air heater 56 is energized, the relay R2 and the relay Rs are turned on, the respective contacts r2 and rs are closed, the cell motor M is operated, and the stop solenoid 4 is activated.
The engine 9 is started by operating 9 to hold the governor in the starting position.

[0014]

Since the present invention is configured as described above, the working machine does not operate even if the operating lever or the operating pedal is operated only by pushing the lever lock switch, and if the lever lock switch is pushed when the work is stopped, the operator can operate. If you accidentally touch it, the work machine will not operate and you can safely leave your seat. Further, when the emergency stop switch is turned on, the engine is stopped and the controller is also stopped, so that danger can be avoided quickly, and thus safety can be improved.

[Brief description of drawings]

FIG. 1 is a control block diagram.

FIG. 2 is a plan view of an operation panel.

FIG. 3 is an electric circuit diagram of a power supply unit.

FIG. 4 is a hydraulic circuit diagram of an electromagnetic proportional valve and a cutoff valve.

[Explanation of symbols]

 C Controller E Engine 23 Electromagnetic proportional valve 25 Boom 26 Arm 27 Bucket 44 Emergency stop switch 45 Lever lock switch 49 Stop solenoid 50 Cut-off valve

Claims (2)

[Claims] 1. A lever comprising a controller for calculating an output signal of an electric lever or pedal for operating a work machine, and a structure for operating a work machine by driving an electromagnetic proportional valve based on the signal calculated by the controller. A safety device for a work equipment operating device, characterized in that when a lock switch is turned on, a cutoff valve that stops the supply of pilot pressure to the solenoid proportional valve is actuated to disable a lever or pedal. 2. A controller for calculating an output signal of an electric lever or pedal for operating a work machine, and a structure for operating a work machine by driving an electromagnetic proportional valve based on the signal calculated by the controller. When the stop switch is turned on, the stop solenoid connected to the governor is turned off, the engine is stopped, and the power supply to the controller is stopped.