JPH0719932Y2 - Anti-theft switch device for construction machinery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention mainly relates to an antitheft switch device for construction machines, industrial vehicles and the like.

2. Description of the Related Art FIG. 2 is a partially cutaway side view of a hydraulic excavator in a construction machine. In the figure, 1 is a lower traveling structure of the hydraulic excavator, 2 is an upper revolving structure, 3 is a driver's cab provided in the upper revolving structure 2, and 4 is a driver's seat in the operator's cab 3. Figure 3 shows
FIG. 3 is a detailed view of part A in FIG. 2. In the figure, 5 is an operation lever, 6 is a control box, 7 is a push-type knob,
8 is a base, 9 is a floor plate, 10 is a support bracket, 11 is an arm, 12 is a bracket, 13 is a mechanical lock mechanism, 14
Is a push bar, 15 is a push-pull cable, 16 is a contact, and 17 is a limit switch. FIG. 4 is a lock circuit diagram for a conventional operating lever. In the figure, 19 is one pilot switching valve of various hydraulic actuators (not shown) mounted on the hydraulic excavator, 20, 21 are pilot switching valves 19 pilot pressure receiving parts on the left and right, 22 is a main pump, and 23 is a remote control valve. , 24 and 25 are pilot valves of the remote control valve 23, 26 is a pilot pump, 27 is a solenoid valve,
28 is a solenoid of the solenoid valve 27, 29 is a battery relay, 30 is an engine key switch, and 31 is a power supply.

Next, the configuration of the operating lever lock circuit in the prior art will be described with reference to FIGS. 3 and 4. A control box 6 that can be tilted in the front-rear direction is provided on the left and right front sides of the driver's seat 4, and an operation lever 5 for a remote control valve 23 for switching and controlling a pilot switching valve 19 for various hydraulic actuators is provided on the upper part of the control box 6 and further the above control. A contact 16 is provided on the box 6. Meanwhile, driver's seat 4
A limit switch 17 is fixedly attached to the side base table 8, and when the control box 6 is rotated to the rear end position a, the contact 16 comes into contact with the limit switch 17, and the pilot pump 26 and the remote control valve are attached. The solenoid valve 27 interposed in the oil passage communicating with 23 is configured to be switched to the oil passage cutoff position.

Next, the function and function of the operating lever lock circuit in the prior art will be described. When the knob 7 provided on the upper part of the control box 6 is pushed downward (in the direction of arrow B), the pushing force is the push bar 14 and the push-pull cable.
After 15, the mechanical lock mechanism 13 is acted on and the lock operation of the mechanical lock mechanism 13 is released. Therefore, if the knob 7 is kept pressed, the tilt of the control box 6 can be adjusted with a light force. The control box 6 can be tilted and adjusted within the range of the angle α from the rear end position a. When the driver tilts the control box 6 to a desired angle position that is most suitable for the operation, and if the finger is released from the knob 7, the knob 7 returns to its original position, and the mechanical lock mechanism 13 is locked and the control is performed. Box 6 is fixed. Therefore, the driver may get off the vehicle with the engine key switch 30 kept in the closed state for the purpose of inspecting the aircraft. At that time, the driver returns the control box 6 to the rear end position a. Then, the contact 16 provided in the control box 6 contacts the limit switch 17 attached to the base 8 on the side of the driver's seat 4, and the limit switch 17 is turned off. As a result, the solenoid 28 of the solenoid valve 27 is de-energized and the solenoid valve 27
Changes from the oil passage opening position C to the oil passage shut-off position D. Therefore, the pressure oil supply from the pilot pump 26 is shut off to the remote control valve 23. In this state, even if the operation lever 5 is operated in the e position direction or the f position direction,
It is not derived for the pilot switching valve 19. Therefore, when the driver gets off the vehicle, for example, even if a part of the driver's body comes into contact with the operation lever 5, the unexpected actuator does not start operating. That is, the operation lever 5 becomes inoperable by returning the control box 6 to the rear end position a.

Problems to be solved by the invention The key switch for the engine of the hydraulic excavator is different from the case of the automobile because of the production management and the like, so that the common key can be used, so that other people use the common key. However, the hydraulic excavator was able to move freely. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide an antitheft switch device in which a key switch is provided in a lock circuit for an operating lever.

Means for solving the problems a. In the present invention, in the construction machine in which the control box is provided on both left and right sides of the driver's seat so that the control box can be tilted in the front-rear direction, and the tilting of the upper end position of the control box disables the operation of various hydraulic actuators by the remote control valve operation lever, B. A solenoid valve is installed in the oil passage between the pilot pump and the remote control valve for operating various hydraulic actuators, and the tilt of the control box is detected in the solenoid valve solenoid and the electric circuit for driving the solenoid that passes through the power supply. Limit switch and anti-theft key switch are installed in series, and c. The key switch was attached to any position of the machine body.

Action a. If the antitheft key switch is turned off, the solenoid valve that locks the operation lever of the remote control valve cannot be set to the oil passage opening position even when the engine is operated and the operation lever is unlocked. That is, the engine mounted on the hydraulic excavator can be rotated, but the hydraulic excavator cannot be operated.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a circuit diagram showing a switch device according to the present invention. In the figure, the same reference numerals are given to those using the same constituent elements as those in the prior art. 34 is a theft prevention key switch.

Next, the configuration of the switch device according to the present invention will be described with reference to FIG. An anti-theft key switch in series with the above limit switch 17 in the electric circuit of the solenoid valve 27 interposed in the pilot pressure oil passage that connects the pilot pump 26 and the remote control valve 23 to the power source 31 from the solenoid 28 of the solenoid valve 27. 34 are arranged. Along with that, the above key switch 34
Was attached to any position on the fuselage. The anti-theft key switch is not limited to one, but a plurality of key switches may be connected in series and the plurality of key switches may be arranged at a plurality of hidden positions.

Next, the function and function of the switch device according to the present invention will be described. The control box 6 is returned to the rear end, and the engine key switch 30 is opened to stop the operation of the hydraulic excavator. When the hydraulic excavator is left as it is, the antitheft key switch 34 arranged at any hidden position of the hydraulic excavator is turned off. In this way, even if the engine key switch 30 is turned on, the control box 6 is tilted forward, and the battery relay 29 and the limit switch 17 are closed, the antitheft key switch 34 is still open. 28 is not energized. As a result, the solenoid valve 27 is in the oil passage shut-off position D, and the operation lever 5 remains inoperable. Therefore, the engine mounted on the hydraulic excavator (not shown)
Cannot operate the hydraulic excavator by rotating it. Further, since the anti-theft key switch 34 is disposed at any hidden position of the hydraulic excavator machine body, the position is known only to a limited person such as the driver of the hydraulic excavator. Therefore, other people can
Finding 34 and closing that circuit is difficult. This prevents the hydraulic excavator from being stolen.

Effect of the Invention The key switch for the engine of the hydraulic excavator allows the common key to be used unlike the case of an automobile because of reasons such as production control. I was able to move freely.

However, in the switch device of the present invention, an electromagnetic circuit is provided in the oil passage between the pilot pump and the remote control valve for operating various hydraulic actuators, which locks the operation lever of the remote control valve, and an electric circuit through the power supply. Since a key switch for theft prevention is installed in series with the limit switch that controls the lock switching of the solenoid valve, it is impossible to operate the construction machine even if another person can rotate the engine. become. Therefore, since the turning of the construction machine and the operation of the work attachment cannot be performed, as a result, the operation for self-propelled loading on the trailer or the like and the adjustment of the packing form become impossible, and the theft of the construction machine can be prevented.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a switch device according to the present invention,
FIG. 2 is a partially cutaway side view of the hydraulic excavator, FIG. 3 is a detailed view of portion A of FIG. 2, and FIG. 4 is a lock circuit diagram for a conventional operating lever. 5 …… Operating lever 6 …… Control box 16 …… Contact 17 …… Limit switch 19 …… Pilot switching valve 23 …… Remote control valve 26 …… Pilot pump 27 …… Solenoid valve 28 …… Solenoid 30 …… For engine Key switch 34 …… Anti-theft key switch

Claims (1)

[Scope of utility model registration request] 1. A construction machine in which a control box is provided on both left and right sides of a driver's seat so as to be tiltable in the front-rear direction, and various hydraulic actuators cannot be operated by a remote control valve operation lever by tilting an upper end position of the control box. , A solenoid valve is installed in the oil passage between the pilot pump and the remote control valve for operating various hydraulic actuators, and the control box is tilted to the solenoid valve solenoid and the electric circuit for driving the solenoid through the power supply. An anti-theft switch device for a construction machine, wherein a limit switch for detection and an anti-theft key switch are provided in series, and the key switch is attached to any position on the machine body.