KR101069450B1 - Safety apparatus and service system for working machine - Google Patents

Abstract

The safety device of the working machine is a hydraulic actuating device for driving the working machine by the hydraulic oil from the hydraulic source, and the operation of the hydraulic actuating device is prohibited when the gate lock lever is operated to the locked position, and the hydraulic actuating device when operated to the unlocking position. A control device that permits operation of the operating device and two switches for detecting that the gate lock lever is in the unlocked position.

Main pump, pilot pump, actuator, operation lever, controller

Description

Safety device of work machine and service system of work machine {SAFETY APPARATUS AND SERVICE SYSTEM FOR WORKING MACHINE}

1 is an electric and hydraulic circuit diagram showing a configuration of a safety device according to a first embodiment of the present invention.

Fig. 2 is a perspective view showing a state in which the gate lock lever is operated to the unlock position.

Fig. 3 is a perspective view showing a state where the gate lock lever is operated to the locked position.

4 is a view for explaining the operation of the safety device shown in FIG.

5 is an electric and hydraulic circuit diagram showing a configuration of a safety device according to a second embodiment of the present invention.

6 is an electric and hydraulic circuit diagram showing a configuration of a safety device according to a third embodiment of the present invention.

7 is a view showing a modification of the safety device shown in FIG.

8 is a view showing another modification of the safety device shown in FIG.

9 is a diagram showing a schematic configuration of a service system of a work machine.

<Explanation of symbols for the main parts of the drawings>

1: main pump

2: pilot pump

3: Actuator

4: control valve

5: operation lever

6: hydraulic pilot valve

7: electromagnetic valve

8, 9: limit switch

10: gate lock lever

11: fault diagnostic port

12: display monitor

13: battery

14: engine

15: potentiometer

16: alarm

17: relay

50: driver

100: working machine

101: safety device

102: transmitting device

200: communication satellite

300: base station

400: terminal

[Document 1] Japanese Unexamined Patent Publication No. Hei 8-302748

The present invention relates to a safety device of a working machine having a gate lock lever and a service system of the working machine.

Japanese Patent Laid-Open No. Hei 8-302748 discloses the safety of a work machine such as a crawler crane equipped with a gate lock lever operable between a lock release position protruding in an elevation path to a driver's seat and a lock position retracted from an elevation path. An apparatus is disclosed. This device allows operation of various actuators (for example, hydraulic motors or hydraulic cylinders) in response to the operation of the operation lever when the gate lock lever is in the unlocked position, and operation when the gate lock lever is operated to the locked position. Force stop the actuator regardless of lever operation. In this kind of device, the ascent to the driver's seat is prevented when the gate lock lever is in the unlocked position, so that the gate lock lever is inevitably operated to the locked position when the crew is separated from the driver's seat. Therefore, there is no fear that the actuator will be operated in the absence of the crew.

In the safety device described in the above publication, when the gate lock lever is in the unlocked position, the limit switch is turned on, so that the oil pressure from the pilot pump can be supplied to the pilot valve by switching the electromagnetic valve. When the gate lock lever is in the locked position, the limit switch is turned off, and the supply of pressure oil to the pilot valve is prohibited by switching the electromagnetic valve. Therefore, if overcurrent flows to the limit switch for some reason and the limit switch is fixed in the on state, even if the gate lock lever is operated to the locked position, supply of pressure oil to the pilot valve is not prohibited, and the safety device does not function effectively. There is a possibility of not.

The safety device of the working machine according to the first aspect of the present invention is a hydraulic actuating device for driving the working machine by pressure oil from a hydraulic source, and prohibits the operation of the hydraulic actuating device when the gate lock lever is operated to the locked position, It is provided with the control apparatus which allows operation | movement of a hydraulic actuating device, when operated to a release position, and the 2 or more system detection apparatus which detects that a gate lock lever is in a lock release position.

In the safety device for a working machine according to the first aspect, the detection device is preferably an electrical detection device. The detection device may have an electrical detection device and a hydraulic detection device, or an electrical detection device and a mechanical detection device.

In the safety device of a working machine according to the first aspect, the detection device has two switches arranged in series to operate in conjunction with the gate lock lever, and the control device (a) has a gate lock lever installed in the lifting path of the working machine. Valve opens the hydraulic passage to the hydraulic actuating device when the valve is operated to the lock position to open the lifting path, and communicates the hydraulic passage to the hydraulic actuating device when the gate lock lever is operated to the lock release position to block the lifting path. Device and (b) an electrical circuit disposed in series with the two switches and controlling the operation of the valve device in accordance with the signals from the two switches, wherein the electrical circuit has a switch abnormality in which one of the two switches performs abnormal operation. If the other side is operating normally, the valve length is set so that the hydraulic flow path is shut off when the gate lock lever is operated to the lock position. To control the preferred.

In the safety device of a working machine according to the first aspect, the detection device has two switches that operate in conjunction with the gate lock lever, and the control device includes (a) a gate lock lever provided in the lifting path of the working machine to lift the lifting path. A valve device that blocks the flow path of the hydraulic pressure to the hydraulic actuating device when operated to the open lock position, and communicates the flow path of the hydraulic pressure to the hydraulic actuating device when the gate lock lever is operated to the lock release position that blocks the lifting path; b) When the signal input from the two switches is abnormal for the other switch, the valve device is connected so that the hydraulic flow path is communicated when the gate lock lever is operated to the lock release position, and the hydraulic flow path is blocked when the gate lock lever is operated to the lock position. You may be provided with the valve control apparatus to control.

In the safety device of a working machine according to the first aspect, the detection device has a switch operating in conjunction with a gate lock lever, and a potentiometer for outputting a signal according to the lock position and the unlock position of the gate lock lever, and the control device includes: (a) When the gate lock lever installed on the lifting path of the working machine is operated in the lock position to open the lifting path, the hydraulic flow path to the hydraulic actuator is blocked, and the gate lock lever is moved to the lock release position to block the lifting path. A valve device that communicates a hydraulic flow path to the hydraulic actuating device when operated, and (b) a signal from the switch and the potentiometer when it is determined that the gate lock lever is operated to the unlocked position based on the signal from the potentiometer. On the basis of the following, (1) if it is determined that the switch is normal, the hydraulic flow path is communicated, and (2) To block the flow path of the oil pressure in the abnormal position may be provided with a valve control device for controlling the valve device.

In the safety device of a working machine according to the first aspect, the detection device has a switch operating in conjunction with a gate lock lever, and a potentiometer for outputting a signal according to the lock position and the unlock position of the gate lock lever, and the control device includes: (a) When the gate lock lever installed in the lifting path of the working machine is operated to the lock position to open the lifting path, the hydraulic flow path to the hydraulic actuating device is shut off, and the gate lock lever is operated to the lock release position to block the lifting path. And (b) a switch failure in which the operating position of the gate lock lever in response to the signal from the potentiometer and the operation position of the gate lock lever in response to the signal from the switch are mismatched. Controlling the valve device to block or communicate with the hydraulic passage based on a signal from the potentiometer A valve control device may be provided.

An abnormality notification device which notifies a switch abnormality at the time of a switch abnormality may further be provided.

In the safety device of a working machine according to the first aspect, the detection device has two switching switches connected in series which are switched by the movement of the gate lock lever, and the control device is a hydraulic actuating device when both of the switching switches are on. Device which has an electromagnetic valve which permits the operation of the switch and prohibits the operation of the hydraulic actuating device when both of the two switching switches are off, and notifies the switch abnormality when one of the two switches is on and the other is off. You may further be provided. The abnormality notification device is preferably an alarm sound generating device or a display device. The abnormality notification device may store the switch abnormality information in the nonvolatile memory, and may always notify the switch abnormality based on the stored information.

A service system for a work machine according to a second aspect of the present invention includes a work machine equipped with the safety device according to the first aspect, a transmission device for transmitting the switch abnormality information from the safety device to the base station, and a switch transmitted to the base station. A notification device for notifying the service member of the above information is provided.

(1st embodiment)

EMBODIMENT OF THE INVENTION Hereinafter, with reference to FIGS. 1-4, 1st Embodiment at the time of applying this invention to the safety device of a hydraulic excavator (working machine) is demonstrated. 1 is an electric and hydraulic circuit diagram showing a safety device according to a first embodiment, and FIGS. 2 and 3 are perspective views showing an inlet of a cab of a hydraulic excavator.

The safety device of the hydraulic excavator shown in FIG. 1 includes a main pump 1 and a pilot pump 2 driven by the engine 14, and a hydraulic actuator 3 driven by pressure oil from the main pump 1; Control valve 4 for controlling the flow of pressure oil from the main pump 1 to the actuator 3, the operation lever 5 for commanding the drive of the actuator 3, and the operation lever 5 for operation. On / off by operation of the hydraulic pilot valve 6 driven by, the electromagnetic valve 7 which permits or prohibits the supply of the hydraulic oil from the pilot pump 2 to the pilot valve 6, and the gate lock lever 10. The two limit switches 8 and 9, the controller 11, and the display monitor 12 are provided. 13 is a battery. In the first embodiment, a hydraulic cylinder is used as the hydraulic actuator 3. The display monitor 12 is a liquid crystal display device, for example.

When the electromagnetic valve 7 is in a non-energized state and is switched to the position a, supply of pressure oil from the pilot pump 2 to the pilot valve 6 is prohibited. Thereby, even if the operation lever 5 is operated, pilot pressure does not act on the pilot port of the control valve 4, and driving of the hydraulic actuator 3 is prohibited. On the other hand, when the electromagnetic valve 7 is energized and is switched to the position (b), pressure oil is guided from the pilot pump 2 to the pilot valve 6. Thereby, the pilot pressure according to the operation amount of the operation lever 5 acts on the pilot port of the control valve 4, and the drive of the hydraulic actuator 3 becomes possible.

As shown in Figs. 2 and 3, the gate lock lever 10 is rotatably installed in the hatch 50a of the cab 50 of the hydraulic excavator. The crew lowers the gate 50a by lowering the gate lock lever 10 to the lock release position, and opens the gate 50a by raising the gate lock lever 10 to the locked position. That is, when the crew gets on and off, the gate lock lever 10 is operated from the lock release position shown in FIG. 2 to the lock position shown in FIG. In response to the operation of the lock of the gate lock lever 10 to the position of the lock, the electromagnetic valve 7 is switched to the position, and even if the crew accidentally touches the operation lever 5 when the crew rides down, the hydraulic actuator 3 Is not driven, so safety is high.

As shown in Fig. 1, the switches 8 and 9 are respectively switched to the terminal a side when the gate lock lever 10 is in the unlocking position (switch on), and the terminals b are respectively when in the lock position. Switch to the () side. That is, the switches 8 and 9 function as detection devices for detecting that the gate lock lever 10 is in the unlocked position. The switches 8 and 9 are connected in series with the electromagnetic valve 7, so that the solenoid of the electromagnetic valve 7 is excited when the switches 8 and 9 are turned on, and when either one is off or both off, the electromagnetic The solenoid of the valve 7 is demagnetized. The failure diagnosis port 11a of the controller 11 is connected to the terminal a of the switch 8 and the terminal b of the switch 9 via a diode, respectively, and the terminal b of the switch 8 and the switch. Terminal a of (9) is grounded, respectively.

The controller 11 determines the normality or abnormality of the switches 8 and 9 by the signal levels of the switches 8 and 9 input to the failure diagnosis port 11a, and displays the determination result on the monitor 12. The normal or abnormal determination result of the switches 8 and 9 is stored in the nonvolatile memory 11m in the controller 11.

4 shows on and off of the switches 8 and 9, the raising operation (locking) and the lowering operation (lock release) of the gate lock lever 10, the operation and non-operation of the hydraulic actuator 3, and the switch 8 And 9) illustrate the normal and abnormal relations. 4, the main operation of the safety device according to the first embodiment will be described.

(A) Switches (8, 9) are normal

ㆍ case (1)

If both switches 8 and 9 are normal, the switches 8 and 9 are switched in accordance with the operation of the gate lock lever 10. For example, if the crew operates the gate lock lever 10 to the unlocked position after boarding the cab 50, the switches 8 and 9 are switched to the terminal a side, and both the switches 8 and 9 are turned on. (Fig. 4 (1)). As a result, current flows through the solenoid of the electromagnetic valve 7 via the switches 8 and 9, and the electromagnetic valve 7 is switched to the position (b). When operating the operation lever 5 in this state, the pilot pressure according to the operation amount acts on the control valve 4, and the hydraulic actuator 3 can be driven according to the lever operation amount. At this time, the terminal a of the switch 8 is grounded via the switch 9, and the fault diagnosis port 11a of the controller 11 becomes the ground level (low level).

When the crew moves up and down the cab 50, the gate lock lever 10 is operated to the locked position. As a result, the switches 8 and 9 are switched to the terminal b side, respectively, so that the solenoid of the electromagnetic valve 7 is in a non-electrical state, and the electromagnetic valve 7 is switched to the position (a) so that the switches 8 and 9 are switched. Are both off (Fig. 4 (1)). Since the pilot pressure does not act on the control valve 4 even when the operating lever 5 is operated in this state, the drive of the hydraulic actuator 3 can be inhibited. At this time, the b terminal of the switch 9 is grounded via the switch 8, and the fault diagnosis port 11a of the controller 11 becomes the ground level (low level). As described above, when the failure diagnosis port 11a is at a low level, the controller 11 determines that the switches 8 and 9 are in a normal state.

(B) Only one or more of the switches (8, 9)

ㆍ case (2)

Consider a case in which either of the switches 8 and 9 is fixed to the terminal a. For example, when the switch 8 is fixed to the terminal a, the switch 8 is turned on regardless of the operation of the gate lock lever 10 (Fig. 4 (2)). In this state, when the gate lock lever 10 is operated to the locked position, the other switch 9 is switched to the terminal b side. Thereby, the solenoid of the electromagnetic valve 7 will be in a non-electrical state, and driving of the actuator 3 can be prohibited. At this time, the failure diagnosis port 11a of the controller 11 communicates with the battery 13 via the switches 8 and 9 to reach a high level. As a result, the controller 11 determines that the switches 8 and 9 are abnormal, and displays the failure information (abnormal information) on the monitor 12. The controller 11 also stores, in the nonvolatile memory 11m, the determination result that the switches 8 and 9 are abnormal.

Moreover, when the gate lock lever 10 is operated to the unlocking position, the switches 8 and 9 will be turned on both, and the hydraulic actuator 3 can be driven. At this time, the hydraulic actuator 3 can be driven, but the controller 11 indicates that the switches 8 and 9 are abnormal based on the abnormality determination result of the switches 8 and 9 stored in the nonvolatile memory 11m. The failure information is displayed on the monitor 12.

ㆍ case (5)

On the other hand, when either of the switches 8 and 9, for example, the switch 8 is fixed to the terminal b, the switch 8 is turned off regardless of the operation of the gate lock lever 10 (Fig. 4 (5)]. Even when the gate lock lever 10 is operated in the unlocked position in this state, the solenoid of the electromagnetic valve 7 is not energized and the driving of the hydraulic actuator 3 can be prohibited. At this time, the failure diagnosis port 11a of the controller 11 communicates with the battery 13 to a high level. As a result, the controller 11 determines that the switches 8 and 9 are abnormal, and displays the failure information on the monitor 12. The controller 11 also stores the determination result that the switches 8 and 9 are abnormal in the nonvolatile memory 11m.

When the gate lock lever 10 is operated from the lock release position to the lock position, both the switches 8 and 9 are turned off. The controller 11 determines that the switches 8 and 9 are abnormal on the basis of the abnormality determination result of the switches 8 and 9 stored in the nonvolatile memory 11m, and displays the failure information on the monitor 12. .

The other case (3) and the case (6) (refer FIG. 4) in which either one of the switches 8 and 9 were stuck are the same as the case (2) and the case (5) mentioned above.

(C) Both sides of the switches 8 and 9 are abnormal

ㆍ case (8)

When either one of the switches 8, 9 (for example, switch 8) is fixed to terminal a, and the other (switch 9) is fixed to terminal b, the solenoid of electromagnetic valve 7 Is always in a non-energized state (Fig. 4 (8)). Thereby, the drive of the hydraulic actuator 3 can be prohibited. At this time, since the fault diagnosis port 11a of the controller 11 becomes a high level, the controller 11 determines that the switches 8 and 9 are abnormal, and displays the fault information on the monitor 12. The controller 11 also stores the determination result that the switches 8 and 9 are abnormal in the nonvolatile memory 11m.

The same applies to the case (8) also in the case (9) (see FIG. 4) when the switch 8 is fixed to the terminal b and the switch 9 is fixed to the terminal a.

ㆍ case (7)

When the switches 8 and 9 are all fixed to the terminal b, the solenoid of the electromagnetic valve 7 is always in the non-energized state (Fig. 4 (7)), and the driving of the hydraulic actuator 3 is prohibited. At this time, the failure diagnosis port 11a of the controller 11 becomes low level. However, since the switches 8 and 9 are not switched even when the gate lock lever 10 is operated, the controller 11 determines that the switches 8 and 9 are abnormal and displays the failure information on the monitor 12. .

ㆍ case (4)

In a state where the switches 8 and 9 are both fixed to the terminal a, the hydraulic actuator 3 can be driven. Since the switches 8 and 9 are not switched in accordance with the operation of the gate lock lever 10, the controller 11 determines that the switches 8 and 9 are abnormal and displays the failure information on the monitor 12.

In addition, in the case (4) and the case (7), for example, when detecting switching of the switches 8 and 9 according to the operation of the gate lock lever, the gate lock lever is detected using a detector such as a potentiometer. The operation state of (10) may be detected, and the on / off signals of the switches 8 and 9 may be input to the controller 11.

According to the above first embodiment, the following effects can be obtained.

(1) Two actuators 8, 9 for switching in accordance with the operation of the gate lock lever 10 are provided in series in the electric circuit for driving the electromagnetic valve 7, and the hydraulic actuator is fixed even when either of them is fixed in the on state. An electric circuit was configured to prohibit driving of (3). As a result, the safety device can be effectively operated, and safety is improved.

(2) When one of the switches 8 and 9 is fixed in the on state, when the gate lock lever 10 is operated in the locked position, the drive of the hydraulic actuator 3 is prohibited, and the gate lock lever 10 is turned off. Operation to the unlocking position was allowed to drive the hydraulic actuator 3. As a result, even if one of the switches 8 and 9 is broken, work can be performed as usual.

(3) Since the excitation current flows to the electromagnetic valve 7 via the switches 8 and 9, the electromagnetic valve 7 can be excited without the control signal from the controller 11, and the configuration is easy.

(4) Since the controller 11 determines the normality and abnormality of the switches 8 and 9 and displays the determination result on the monitor 12 in accordance with the signal level input to the fault diagnosis port 11a, the switches 8 and 9 The crew can easily recognize whether) is normal or abnormal.

(2nd embodiment)

With reference to FIG. 5, 2nd Embodiment of the safety device by this invention is described.

The second embodiment differs from the first embodiment in the configuration of an electric circuit for driving the electromagnetic valve 7. That is, in the first embodiment, the exciting current flows to the electromagnetic valve 7 via the switches 8 and 9, but in the second embodiment, the signal from the switches 8 and 9 is introduced into the controller 11 to control the controller. The electromagnetic valve 7 is switched by the control signal from (11). The differences from the first embodiment will mainly be described below.

5 is an electric and hydraulic circuit diagram showing a safety device according to a second embodiment. In addition, the same code | symbol is attached | subjected to the same site | part as FIG. As shown in Fig. 5, the switches 8 and 9 are connected to the fault diagnosis ports 11a and 11b of the controller 11, respectively, and the controller 11 is provided with on and off signals from the switches 8 and 9, respectively. Is entered. The controller 11 outputs a control signal to the electromagnetic valve 7 in accordance with the on / off signals of the switches 8 and 9, determines the abnormality of the switches 8 and 9, and sends the determination result to the monitor 12. Display.

For example, if both of the switches 8 and 9 are normal, as shown by the solid line in Fig. 5, when the gate lock lever 10 is operated to the unlocking position, the switches 8 and 9 respectively switch to the terminal a side. And the switches 8 and 9 are turned on. As a result, the controller 11 switches the electromagnetic valve 7 to a position (b), thereby enabling the hydraulic actuator 3 to be driven. On the other hand, when the gate lock lever 10 is operated to the locked position shown by the broken line in Fig. 5, the switches 8 and 9 are respectively switched to the terminal b side, and both the switches 8 and 9 are turned off. As a result, the controller 11 switches the electromagnetic valve 7 to the position a to prohibit driving of the hydraulic actuator 3. In this way, when the switches 8 and 9 are simultaneously switched by the operation of the gate lock lever 10, the controller 11 determines that the switches 8 and 9 are normal, and the state of the switches 8 and 9 is determined. Therefore, the electromagnetic valve 7 is controlled.

On the other hand, when either of the switches 8 and 9 is fixed to the terminal a, even if the gate lock lever 10 is operated to the locked position, either of the switches 8 and 9 is in the on state, Only the other switches 8 and 9 are turned off. When the two signal levels are different in this way, the controller 11 determines that either one of the switches 8 and 9 is faulty, turns the electromagnetic valve 7 into a non-energized state, and simultaneously sends fault information to the monitor 12. Display. Thus, even when one of the switches 8 and 9 is fixed in the ON state, the actuator 3 can be prevented from being driven by the operation of the gate lock lever 10 to the locked position. In this case, the on-off signals from the switches 8 and 9 are displayed on the monitor 12, and the crew compares the operation position of the gate lock lever 10 to determine which switch 8 or 9 is broken. Can be recognized.

When both of the switches 8 and 9 are fixed, the controller 11 detects that the signal levels of the switches 8 and 9 are not switched in accordance with the operation of the gate lock lever 10, so that the switches 8 and 9 It is possible to determine that both sides of 9) are faulty. At this time, the controller 11 turns the electromagnetic valve 7 into a non-energized state and displays failure information on the monitor 12. The operation state of the gate lock lever 10 can be detected by a detector such as a potentiometer, for example.

In addition, the output of the control signal (operation of the hydraulic actuator 3) from the controller 11 to the electromagnetic valve 7 with respect to the signals from the switches 8 and 9 is shown in Figs. Is the same.

(Third embodiment)

A third embodiment of the safety device according to the present invention will be described with reference to FIG.

The third embodiment differs from the first embodiment in the configuration of an electric circuit for driving the electromagnetic valve 7. In other words, in the first embodiment, two switches 8 and 9 are provided in the electric circuit. In the third embodiment, the potentiometer 15 is provided in place of the switch 9. That is, in 2nd Embodiment, the switch 8 and the potentiometer 15 function as a detection apparatus which detects that the gate lock lever 10 is in a release position. The differences from the first embodiment will mainly be described below.

6 is an electric and hydraulic circuit diagram showing a safety device according to a third embodiment. In addition, the same code | symbol is attached | subjected to the same site | part as FIG. As shown in Fig. 6, in the third embodiment, the potentiometer 15 for detecting the operation position of the gate lock lever 10 is provided in the rotating portion of the gate lock lever 10. As shown in Figs. A switch 8 and a potentiometer 15 are connected to the failure diagnosis ports 11a and 11b of the controller 11, respectively, so that the a terminal of the switch 8 is grounded and the b terminal is open. The potentiometer 15 outputs a low level signal when the gate lock lever 10 is in the unlocked position, and outputs a high level signal when the gate lock lever 10 is in the locked position. The switch 8 outputs a low level signal when switched to the terminal a side, and outputs a high level signal when switched to the terminal b side.

For example, if the switch 8 is normal, as shown by the solid line in Fig. 6, when the gate lock lever 10 is operated to the unlocking position, the switch 8 is switched to the terminal a side, and the Low-level signals are input to the failure diagnosis ports 11a and 11b, respectively. As a result, the controller 11 switches the electromagnetic valve 7 to the position (b), so that the hydraulic actuator 3 can be driven. On the other hand, when the gate lock lever 10 is operated to the locked position as indicated by the broken line in Fig. 6, the switch 8 is switched to the terminal b side, and the fault diagnosis ports 11a and 11b of the controller 11 are respectively provided. The high level signal is input. As a result, the controller 11 switches the electromagnetic valve 7 to the position a to prohibit driving of the hydraulic actuator 3. In this way, when a signal having the same level is input to the fault diagnosis ports 11a and 11b, the controller 11 determines that the switch 8 is normal, and switches the electromagnetic valve 7 in accordance with the on / off of the switch 8. do.

On the other hand, when the switch 8 is fixed to the terminal a, when the gate lock lever 10 is operated to the locked position, a low level signal is input to the failure diagnosis port 11a of the controller 11, and the failure diagnosis is performed. The high level signal is input to the port 11b. In this way, when the two signal levels are different, the controller 11 determines that the switch 8 is in a failure state, turns the electromagnetic valve 7 into a non-energized state, and displays failure information on the monitor 12. As a result, even when the switch 8 is stuck in the on state, the drive of the actuator 3 can be inhibited by the operation of the gate lock lever 10 to the lock position.

When the gate lock lever 10 is operated to the unlocked position when the switch 8 is fixed to the terminal b, a high level signal is input to the fault diagnosis port 11a of the controller 11, and the fault diagnosis port ( A low level signal is input to 11b). Also in this case, the controller 11 determines that the switch 8 is in a failure state, makes the electromagnetic valve 7 non-energized, and displays the failure information on the monitor 12. Further, when it is determined that the switch 8 is faulty, the operating position of the gate lock lever 10 is determined by the signal input to the fault diagnosis port 11b, and the electromagnetic valve 7 is in accordance with the signal from the potentiometer 15. ) May be controlled.

(Variation)

In the above first and second embodiments, even when the switches 8 and 9 are in a normal state, a signal different from the normal state until the switches 8 and 9 are completely switched when the gate lock lever 10 is operated. It may output In such a case, it is preferable that the controller 11 monitor the signal level of the failure diagnosis ports 11a and 11b for several seconds, and then determine the abnormal abnormality of the switches 8 and 9. The same applies to the third embodiment.

In the first to third embodiments, the abnormality determination results of the switches 8 and 9 are displayed on the monitor 12. However, as shown in Fig. 7, an alarm (alarm sound generating device) such as a buzzer or a horn is shown. (16) may notify the switch abnormality. That is, the abnormality notification means is not limited to the above.

In the first to third embodiments, the abnormality determination results of the switches 8 and 9 are displayed on the monitor 12 using the controller 11, but as shown in FIG. 8, instead of the controller 11, a relay is used. (17) may be provided and the alarm may be generated from the alarm device 16 by switching the relay 17.

The abnormality determination result by the controller 11 is memorize | stored in the nonvolatile memory 11m, and the abnormality information of the switches 8 and 9 is always displayed on the monitor 12, or the alarm 16 when an engine is started. The abnormality determination result may be informed from the user. That is, after determining that the switches 8 and 9 are abnormal, notification of abnormality information may be continued until the engine turns off.

It is also possible to configure the service system of the work machine by using the safety device described above. 9 shows a schematic configuration of a service system of a work machine. The working machine 100 transmits the abnormality information of the switches 8 and 9 detected by the safety device 101 from the transmitting device 102 to the base station 300 which is remote via the communication satellite 200. The base station 300 transmits the abnormality information transmitted from the work machine 100 to the terminal 400 of the service member in charge by e-mail or the like. The service person in charge may arrange the new switches 8 and 9 on the basis of the received abnormality information. In addition, the notification apparatus for notifying abnormal service information to the service person in charge is not limited to email. It is of course also possible to manage a plurality of working machines by the base station 300.

In the first to third embodiments, the operating positions of the gate lock levers 10 are detected by the switches 8 and 9 or by electrical detection means such as the switch 8 and the potentiometer 15. However, as long as it detects that the gate lock lever 10 is in the unlocking position by two or more detection means, a detection means is not limited to what was mentioned above. The position of the gate lock lever 10 may not only be detected by the electrical detection means, but the position of the gate lock lever 10 may be detected by other means in addition to the electrical detection means. For example, a hydraulic switching valve that is switched in conjunction with the operation of the gate lock lever 10 is provided, and the hydraulic switching valve mechanically detects the position of the gate lock lever 10 by switching (mechanical detection means), The hydraulic switching valve may hydraulically detect the position of the gate lock lever 10 by the pilot pressure by switching (hydraulic detection means).

Although the hydraulic actuator 3 is driven by the hydraulic pressure from the main pump 1 supplied via the control valve 4, the configuration of the hydraulic actuating device is not limited to this. Although the electromagnetic valve 7 was installed in the flow path through which the pilot pressure was supplied, and the pilot pressure was controlled, the flow path from the main pump 1 to the hydraulic actuator 3 was indirectly communicated or interrupted, but from the main pump 1 The electromagnetic valve 7 may be provided in a flow path through which hydraulic pressure is supplied, and the flow path from the main pump 1 to the hydraulic actuator 3 may be directly communicated or interrupted. That is, the configuration of the valve device is not limited to the above.

In the second and third embodiments (Figs. 5 and 6), the electromagnetic valve 7 is switched by the control signal from the controller 11, but the gate lock lever 10 is abnormal when the switches 8 and 9 are abnormal. Is to lock the electromagnetic valve 7 when the key is operated in the locked position, the configuration of the controller 11 as the control means is not limited to the above.

As described above, according to the first to third embodiments and modified examples thereof, since two or more systems are provided with a detection device for detecting that the gate lock lever 10 is in the unlocked position, when one system fails. Even the gate hydraulic actuating device can be prevented from operating, thereby improving safety.

Although the example which applied the safety device to the hydraulic excavator was demonstrated in the said, 1st-3rd embodiment and its modified example, this invention is similarly applicable to the other working machines which have the gate lock lever 10. FIG. That is, the present invention is not limited to the safety device of the embodiment as long as the features and functions of the present invention can be realized. In addition, the above description is an example to the last, and when interpreting an invention, neither a limitation nor a restriction | limiting is carried out in the correspondence relationship of the description of the said embodiment, and the description of a claim.

According to the present invention, the safety of the safety device of the gate hydraulic actuating device is improved by the configuration including two or more detection devices that detect that the gate lock lever is in the unlocked position.

Claims (12)

A hydraulic actuating device for driving the work machine by oil pressure from an oil pressure source driven by the engine, The operation of the gate lock lever provided in the lift path to the lock position to open the lift path to shut off and lock the hydraulic flow path in the hydraulic actuating device, and the operation to the lock release position to block the lift path to the lock position. A valve device for unlocking by communicating a hydraulic path in the hydraulic operation device; Two switches which operate in conjunction with the gate lock lever and are arranged in series so as to be all turned on or off in accordance with the operation of the gate lock lever; Disposed in series with the two switches, having an electrical circuit for switching the locking and unlocking of the valve device by switching between the two switches, The electrical circuit (a) switches both locking and unlocking of the valve device in accordance with the operation of the gate lock lever when both of the two switches operate normally in conjunction with the gate lock lever, and (b) the On the operation of the gate lock lever, even when a switch abnormality operates in which one of the two switches does not interlock with the gate lock lever, when the other operates normally, the operation of the gate lock lever to the lock position A safety device for a work machine, which locks the valve device at the time. A hydraulic actuating device for driving the work machine by oil pressure from an oil pressure source driven by the engine, The operation of the gate lock lever provided in the lift path to the lock position to open the lift path to shut off and lock the hydraulic flow path in the hydraulic actuating device, and the operation to the lock release position to block the lift path to the lock position. A valve device configured to communicate with and release the hydraulic flow path in the hydraulic actuating device; Two switches that operate in the locked position and the unlocked position of the gate lock lever in conjunction with the gate lock lever to output the same signal; When the signal input from the two switches at the lock position of the gate lock lever is different from the other switch, the valve device is unlocked when the gate lock lever is operated to the lock release position, and the gate lock lever is And a control device for locking the valve device when operated in the locked position. A hydraulic actuating device for driving the work machine by oil pressure from an oil pressure source driven by the engine, The operation of the gate lock lever provided in the lift path to the lock position to open the lift path to shut off and lock the hydraulic flow path in the hydraulic actuating device, and the operation to the lock release position to block the lift path to the lock position. A valve device configured to communicate with and release the hydraulic flow path in the hydraulic actuating device; A switch operating in a locked position and a unlocked position of the gate lock lever in conjunction with the gate lock lever; A potentiometer for outputting a signal according to the locked position and the unlocked position of the gate lock lever; When it is determined by the signal of the potentiometer that the gate lock lever has been operated to the lock release position, and the switch is determined to be normal based on the signal from the switch and the potentiometer, the valve device is unlocked. And a control device for locking the valve device when the switch abnormality is determined that the switch is abnormal. A hydraulic actuating device for driving the work machine by oil pressure from an oil pressure source driven by the engine, The operation of the gate lock lever provided in the lift path to the lock position to open the lift path to shut off and lock the hydraulic flow path in the hydraulic actuating device, and the operation to the lock release position to block the lift path to the lock position. A valve device configured to communicate with and release the hydraulic flow path in the hydraulic actuating device; A switch operating in a locked position and a unlocked position of the gate lock lever in conjunction with the gate lock lever; A potentiometer for outputting a signal according to the locked position and the unlocked position of the gate lock lever; The valve device on the basis of a signal from the potentiometer in a switch abnormality in which the operation position of the gate lock lever and the operation position of the gate lock lever according to the signal from the switch are inconsistent according to the signal from the potentiometer And a control device for locking or unlocking the safety device. The said valve apparatus locks and locks the said hydraulic flow path in the said hydraulic actuating device by the element of a solenoid, The said valve apparatus in the said hydraulic actuating device by excitation of the said solenoid. An electromagnetic valve for unlocking by communicating a hydraulic flow path, wherein the solenoid is excited when both of the two switches are turned on, and excited when one or both of them is turned off. The safety device of a work machine according to any one of claims 1 to 4, further comprising an abnormality notification device for notifying a switch abnormality at the time of the switch abnormality. Two switching switches connected in series, all of which are switched on or off by the movement of the gate lock lever, An electromagnetic valve which permits the operation of the hydraulic actuating device when both of the two switching switches are on and prohibits the operation of the hydraulic actuating device when both of the two switching switches are off; And an abnormality notification device for notifying a switch abnormality when one of the two switches is on and the other is off. The safety device of a work machine according to claim 7, wherein the abnormality notification device is an alarm sound generating device or a display device. The method of claim 7 or 8, further comprising a nonvolatile memory, The abnormality notification device stores the switch abnormality information in the nonvolatile memory and always notifies the switch abnormality based on the stored information. Service system of working machine, A working machine equipped with the safety device according to any one of claims 1 to 4 or 7, A transmission device for transmitting the switch abnormality information from the safety device to a base station; And a notification device for notifying a service member of information on the switch abnormality transmitted to the base station. delete delete

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