JPH0688360A - Switch circuit for display device for construction machine - Google Patents

Abstract

PURPOSE:To improve safety by a method wherein an interlocking switch operated in linkage with rotation of a display unit is connected to the work lamp circuit for a construction machine. CONSTITUTION:When a work is carried out during operation of a hydraulic shovel as display of a display unit 32 is confirmed, the display unit 32 is opened to a display position. The pin of a shaft part fixed to the display unit 32 is brought into contact with a contact and an interlocking switch 34 is caused to effect ON-operation. Further, when a light switch 27 is turned ON since a work site is dark, back lights 22' and 23' for a liquid crystal of the display unit 32 are lighted ON simultaneously with lighting ON of work lamps 25 and 26. When the display unit 32 is rotated to a containing position in a case confirmation of display of the display unit 32 is not needed, the switch 34 is turned OFF and a containing position signal is inputted to a controller 18'. A command signal for controlling a working machine to the display unit 32 and an electromagnetic proportional pressure reducing valve 19 is not outputted from the controller 18'.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch circuit of a work status display device for a working machine mounted on the front part of a construction machine such as a hydraulic shovel.

[0002]

2. Description of the Related Art FIG. 4 is a diagram showing a hydraulic excavator equipped with a display device and a main circuit of the prior art. In the figure, 1 is a lower traveling body of a 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 side digging mounted on a front portion of the upper revolving structure 2. Working machine 5, 5 is a boom of working machine 4, 6 is a rear boom of boom 5, 7 is a front boom, 8 is an upper boom, 9 is an arm, 10 is a bucket as a working tool, 11 is a boom cylinder as a hydraulic actuator, and 12 is An arm cylinder, 13 is a bucket cylinder, 14 is a pin connecting part at the root of the rear boom 6, 15 is a pin connecting part at the base end of the front boom 7, 16 is a pin connecting part at the base end of the arm 9, and 17 is a tip part of the arm 9. And a bucket 10 with a pin connecting portion, P1 is a boom potentiometer attached to the pin connecting portion 14, and P1 is a boom potentiometer.
2 is an offset potentiometer attached to the pin coupling portion 15, P3 is an arm potentiometer attached to the pin coupling portion 16, a is a boom tilt angle, b is an arm rotation angle,
L1 is the rear boom length, L2 is the front boom length, L
3 is the upper frame length, and L4 is the arm length. Although not shown, in the plan view of the hydraulic excavator in FIG. 4, an offset cylinder for offset-moving the arm 9 is arranged, and the offset angle and the offset amount can be set by its operation. Further, as a constituent element of the main circuit of the hydraulic excavator shown in FIG.
Reference numeral 18 is a controller, 19 is a plurality of hydraulic actuators (boom cylinder 11, arm cylinder 12, bucket cylinder 13, and offset cylinder) which are provided to control a control valve (not shown) for switching. Electromagnetic proportional pressure reducing valve, 20 is an indicator, 21 is a display section of the indicator 20, 22 and 23 are backlights for liquid crystal, 24 is a display backlight switch, 25 and 26 are the working machine 4, and the upper swing body 3. A work light (including before turning off) is attached, 27 is a light switch for blinking the work light (25, 26), and 28 is a power source.

A conventional hydraulic excavator and its main circuit will be described with reference to FIG. When working on the hydraulic excavator, the tip position of the working machine is operated to a desired target position depending on working conditions. In this case, since the detection signals from the potentiometers P1, P2 and P3 are input to the controller 18, the controller 18 calculates the position of the working machine 4 based on the detection signals. The controller 18 judges the calculation result and outputs command signals to the plurality of electromagnetic proportional pressure reducing valves 19 and the display 20, respectively. Therefore, a plurality of hydraulic actuators for the working machine 4 are controlled, and the working height of the working machine 4 and the excavation depth are displayed on the display unit 21 of the display 20.

[0004]

As shown in FIG. 4, in the conventional hydraulic excavator, when performing night work or dark work, the light switch 27 is turned on to operate the work lamp 2.
5 and 26 are turned on, and the display back lighting switch 24 is turned on.
Had to be turned on to turn on the backlights 22 and 23 of the display unit 21 for the display device 20.
The on / off operation of the two switches 27 and 24 is troublesome because various other switches (not shown) must also be operated. Further, in the conventional technology, the display of the display device 20 is not required during excavation work of the hydraulic excavator, and the display is performed even when the driver performs a manual operation, or a command signal from the controller 18 is output to the electromagnetic proportional pressure reducing valve 19. There is a risk that it will be caused, and it cannot be said that it is perfect for safety. The present invention aims to solve the above problems.

[0005]

In a switch circuit of a display device according to the present invention, the display device is rotatably mounted inside a driver's cab between a display position and a storage position via a hinge member. An interlocking switch that operates in conjunction with the rotation of the indicator is installed in the vicinity, and the interlocking switch is connected to the work light circuit of the construction machine.When the indicator is in the display position and the work light circuit is operated by operating the light switch. The LCD backlight of the display unit is energized when energized. When the interlock switch is connected to the controller and the indicator is in the retracted position, the interlock switch retract position signal is input to the controller, which causes the controller to display the display command signal and the work implement control command. The signal is not output.

[0006]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a perspective view of an essential part showing the inside of a driver's cab 3 ′ equipped with a display device of 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. 29 is a cab of the driver's cab 3 ', 30 is a floor plate, 31
Is a driver's cab, 32 is an indicator, 33 is a harness connected to the indicator 32, and 34 is an interlocking switch. FIG. 2 is a detailed view of part A of FIG. In the figure, 35 is a hinge member for attaching the indicator 32 to the cab 29 on the inner surface thereof, 36 is a shaft portion fixed integrally with the main body of the indicator 32 and rotating together with the indicator 32, and 37 is a shaft portion. Pins protruding from 36, 38
Is a contact of the interlocking switch 34, reference numeral a is a display position of the display 32, virtual line B is a storage position, and arrow C is a rotation direction. FIG. 3 is a switch circuit diagram of 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. 18 'is a controller, 39 is a display 3
2 is a display unit, 22 'and 23' are backlights for liquid crystal, respectively, and reference numerals C, L, N and L are interlocking switch 3
4 are the contact points.

Next, the configuration of the switch circuit of the display device of the present invention will be described with reference to FIGS. The display device 32 is rotatably attached to the inner surface of the cab 29 via the hinge member 35 between the display position B and the storage position B, and is turned on and off in the vicinity of the display device 32 in conjunction with the rotation of the display device 32. An interlocking switch 34 that operates is provided, and the interlocking switch 34 is connected to the work light circuit. When the display 32 is in the display position B and the work light circuit is energized by turning on the light switch 27, Liquid crystal backlights 22 'and 2
3 was energized. When the interlocking switch 34 is connected to the controller 18 'and the display 32 is in the storage position B, the storage position signal of the interlocking switch 34 is input to the controller 18', so that the controller 18 'displays the display. The display command signal and the work machine control command signal for 32 are not output. In the present embodiment, a limit switch type mechanical switch is used as the interlocking switch 34, but not limited to a mechanical switch, a non-contact type switch (not shown) using a relay, a magnet or the like is used. You may.

Next, the operation of the switch of the display device of the present invention will be described. When the work of the hydraulic excavator is performed while checking the display of the display 32, the display 32 is opened to the display position B as shown in FIG. Since the pin 37 of the shaft portion 36 fixed to the display unit 32 contacts the contact 38, the interlock switch 34 is turned on. When the light switch 27 (shown in FIG. 3) is turned on because the work site is dark when the interlock switch 34 is on, the work lamp 2
The backlights 22 'and 23' for the liquid crystal of the display 32 can be turned on at the same time that 5 and 26 are turned on.
Therefore, it is no longer necessary to separately turn on and off the work light and the backlight as in the prior art.

Next, when working on the hydraulic excavator, the display 32
If it is not necessary to confirm the display of, the display 32 is rotated to the storage position b. Shaft 36 fixed to the display 32
Since the pin 37 does not come into contact with the contact 38, the interlock switch 34 is turned off. A storage position signal of the interlocking switch 34 (a signal indicating that the interlocking switch 34 is in the off state) is input to the controller 18 ′. The controller 18 'makes a determination based on the storage position signal, and does not output the display command signal to the display 32 and the working device control command signal to the plurality of electromagnetic proportional pressure reducing valves 19. Therefore, when the display device 3 is closed to the storage position B, no display is made and the controller 18 'does not automatically move the working machine. That is, in this case,
The hydraulic excavator can be moved only by manual operation.

[0010]

In the conventional hydraulic excavator, a work light and
Since it was necessary to separately turn on and off each switch of the display backlight, the operation was troublesome. Further, when the work is performed without the display of the indicator, the controller may output a command signal to the electromagnetic proportional pressure reducing valve for controlling the working machine, which is not safe. However, in the switch circuit of the display device of the present invention, the interlocking switch of the liquid crystal backlight is turned on when the display device is opened to the display position in order to use the display device. However, in this case, the backlight is not turned on unless the work lamp is turned on. When the work site is dark and the work light is turned on, the above-mentioned backlight is turned on at the same time, which makes it easy to see the display on the display, which is very rational. It is no longer necessary to turn the backlight and work light on and off separately, and it is possible to reduce the hassle of switch operation. If you close the display unit to the storage position when you do not use the display unit, the display will not be displayed.
No command signal is output from the controller to the electromagnetic proportional pressure reducing valve for controlling the work implement. Therefore, when the hydraulic excavator is working without using the indicator, it is safe because the hydraulic excavator is not moved by the command signal of the controller.

[Brief description of drawings]

FIG. 1 is a perspective view of an essential part showing the inside of a driver's cab provided with a display device of the present invention.

FIG. 2 is a detailed view of part A of FIG.

FIG. 3 is a switch circuit diagram of the present invention.

FIG. 4 is a diagram showing a hydraulic excavator equipped with a display device and a main circuit of a conventional art thereof.

[Explanation of symbols]

 3,3 'Operator's cab 4 Working machine 18, 18' Controller 19 Electromagnetic proportional pressure reducing valve 20,32 Indicator 21,39 Display section 22,22 ', 23,23' Backlight 25,26 Working light 27 Light switch 29 Cab 34 Interlocking switch

Claims (2)

[Claims] 1. An operating position detecting means for detecting an operating position of a working machine by connecting a working machine such as a boom, an arm and a working tool to the front part of the upper swing body so that the working machine can perform a bending work motion.
The height of the work machine by the signal from the operating position detecting means,
Operation of the indicator in a construction machine equipped with an arithmetic means for calculating the working position such as the digging depth and a means for displaying the arithmetic result obtained by the arithmetic means on the display. Inside the room, it is rotatably attached to the display position and the storage position via a hinge member, and an interlock switch that operates in conjunction with the rotation of the display is installed near the display, and the interlock switch is constructed. A construction machine characterized in that it is connected to a work light circuit of a machine, and when the display is in the display position and the work light circuit is energized by operating the light switch, the liquid crystal backlight of the display is energized. Switch circuit for display device. 2. The switch circuit of the display device for construction machine according to claim 1, wherein the interlocking switch is connected to the controller, and when the indicator is in the storage position, the storage position signal of the interlocking switch is the controller. A switch circuit of a display device for a construction machine, characterized in that a display command signal for a display device and a work machine control command signal are not output from a controller by being input to the controller.