JP2005307791A - Erroneous operation prevention device for working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve safety by allowing starting of an engine in a condition that a lock lever is turned to a [operation disapproval] position and an actuator for working does not operate and to stop the engine after a predetermined time for not operating the actuator after the starting and then facilitate restarting. <P>SOLUTION: A working vehicle is provided with the lock lever 23 which operates a switch means for switching the actuator for driving a working machine to either of [operation approval] and [operation disapproval]. When the lever is operated to the [operation disapproval] position, the engine 13 is stopped after the predetermined time by a timer 48. A cell motor starting switch 48 is provided separately from a key switch 35 and an engine starting switch 48 is arranged on the lock lever. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is provided with a lock lever for operating a switching means for switching between “operational” and “nonoperational” of an actuator that drives a work machine provided for a backhoe or the like, and operates the lock lever to an “inoperational” position. The present invention relates to a technique for enabling an engine to be started with a simple operation after the engine is stopped after a predetermined time.

  Conventionally, in a work machine such as a backhoe or a loader equipped with an excavating work machine, an operation lever for operating the drive or running of the work machine is arranged near the driver's seat, and when the operator leaves the driver's seat, When the operator leaves the driver's seat so that the operating lever is not accidentally hooked or held, and the operating lever is rotated, the work implement is driven or the aircraft does not travel, A lock device is provided so that the working machine or the like does not operate even if it rotates.

  In addition, there is a technique in which an operation position for stopping the engine while maintaining neutrality is set on the operation lever so that the engine can be stopped quickly when an abnormality occurs in the hydraulic equipment, the engine, or the like (see, for example, Patent Document 1). In this technology, the lock lever is operated when the hydraulic circuit including the directional control valve is made inoperable by operating the lock lever to switch the on-off valve to a position where the pressure regulator and the pilot pump are disconnected. It was controlled to stop the engine in conjunction with the operation.

However, in the middle of work, the operator may leave the seat temporarily in order to check the work position of the work machine or to check the work machine mounting condition. In this case, the engine is stopped every time the lock lever is operated. Therefore, when returning to the seat again and resuming the operation, the operation lever is operated to the startable position and the start switch is required to be troublesome. Accordingly, there is a technique in which the engine is restarted by re-operating the lock lever (see, for example, Patent Documents 2 and 3).
Also, an engine start switch is arranged so that the engine can be easily started when one of the left and right control levers is lowered, and the operation of the working unit is allowed when the other control lever is lowered. There is also a technique (for example, see Patent Document 4).

JP-A-5-44517 JP 2000-96627 A JP 2001-41069 A Japanese Utility Model Publication No. 7-17861

However, in the technique of Patent Document 1, the engine is stopped by rotating the operation lever to the lock position, and wasteful consumption of energy can be suppressed. However, in the case where the work is resumed in a short time, Since the engine is restarted by operating the cell motor after returning to the neutral position, it takes time and increases the amount of battery usage.
Further, in the techniques of Patent Documents 2 and 3, the engine is not stopped if the lock lever is returned to the operable position within a predetermined time after leaving the seat for the purpose, and the engine is not operated after the predetermined time. Even if the engine is stopped, the engine is configured to start when the lock lever is returned to the operable position. However, when the engine is started by operating the key switch, the lock lever must be rotated to the operable position. It cannot be started. Therefore, when the key switch is turned on, the electromagnetic valve is activated, and there is a possibility that a working part such as a boom or an arm may be activated, which may move unintentionally. In addition, since the control is performed using a controller, the cost is increased, and operation signals such as lock levers and key switches are sent to the controller to control the engine and hydraulic equipment, resulting in complicated wiring and malfunction due to noise. There was also the possibility of producing.

Further, in the technique of Patent Document 4, since the engine can be started only when one of the left and right operation levers is in the lowered position and the other is raised, the position where one of the operation levers where the start switch is disposed is lowered. It is easy to understand that the other operation lever can be raised or lowered at the time of starting. Although the left control lever cannot be operated in the raised position, if the right control lever is raised while the left control lever is lowered during the work, it is unknown whether the operation can be performed and whether the engine stops. Whether it is unknown.
According to the present invention, when the lock lever is rotated from the operable position to the locked position where the operation is disabled, the engine is kept operating until a predetermined time elapses, and the engine is stopped after a predetermined time elapses, and unnecessary energy is consumed. It tries to improve safety by preventing consumption and allowing the engine to start only when the lock lever is inoperable.

  The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

  That is, according to the first aspect of the present invention, there is provided a lock lever for operating the switching means for switching between “operational” and “nonoperational” of the actuator that drives the work machine, and the actuator is operated to the “inoperational” position after starting. In a work vehicle in which the engine is stopped after a predetermined time by the delay means, a cell motor starting means is provided separately from the key switch.

  According to a second aspect of the present invention, start restriction means is provided that permits engine start only when the lock lever is in the “not operable” position.

  According to a third aspect of the present invention, engine starting means is disposed on the lock lever.

  According to a fourth aspect of the present invention, engine starting means is disposed on the boarding / alighting auxiliary member.

  As effects of the present invention, the following effects can be obtained.

  In claim 1, when the engine is stopped after a predetermined time by rotating the lock lever to “not operable” to temporarily stop or leave the seat during work, the lock lever can be rotated, It is possible to easily start with another switch without performing troublesome operations such as resetting the timer or re-operating the key switch. Further, since another switch is exclusively for restarting, it can be reliably started without making any mistake.

  According to the second aspect of the present invention, since the engine can be started only at the “inoperable” position, work is not operated simultaneously with the start of the engine, and safety can be further improved.

  According to the third aspect of the present invention, the operation lever for the actuator is operated by operating the lock lever after the engine is started, so that the position of the start switch can be easily understood and an operation error can be prevented. In addition, operations after the engine is started can be performed immediately, and workability can be improved.

  According to the fourth aspect of the present invention, since the start switch is disposed in the vicinity of the driver's seat, the operation for re-operation can be easily performed, and the position of the start switch can be easily understood.

Next, embodiments of the invention will be described.
1 is a side view showing a turning work vehicle having an erroneous operation prevention device for a working vehicle of the invention, FIG. 2 is a plan view of a driving operation unit, FIG. 3 is a hydraulic circuit diagram and an electric circuit diagram of the erroneous operation prevention device for a working vehicle, FIG. 4 is a hydraulic circuit diagram and an electrical circuit diagram when the engine is started, FIG. 5 is a hydraulic circuit diagram and an electrical circuit diagram when the lock lever is set to “inoperable” during the operation, and FIG. 6 is a state where the start switch is operated. FIG. 7 is a perspective view in which a start switch is provided on a boarding / alighting assisting member.

  First, a backhoe will be described as an example of a work vehicle having the hydraulic operating device of the present invention. In FIG. 1, the backhoe is equipped with a work machine 7 in the front part of the machine, and the machine supports the swivel frame 2 at the center of the upper part of the crawler type traveling device 1 through a swivel bearing 17 so as to be able to turn left and right. In addition, a blade 3 is disposed on one side of the front and rear of the crawler type traveling device 1 so as to be rotatable up and down. A bonnet 14 that covers the engine 13 and the like is disposed on the upper part of the revolving frame 2, a driver's seat 16 is disposed on the hood 14, and hydraulic operation levers 21, 22, lock levers 23, 24 and the like, and a driving lever 25 and a pedal are arranged in front of the driver's seat 16 to constitute the driving operation unit 15. A canopy 8 is disposed above the operation unit 15.

  In addition, a boom bracket 12 is attached to the front end portion of the revolving frame 2 so as to be turnable in the left-right direction, and the lower end portion of the boom 6 is supported on the boom bracket 12 so as to be turnable up and down. The boom 6 is bent forward in the middle and is formed in a substantially “<” shape. The arm 5 is rotatably supported at the upper end of the boom 6, and the arm 5 has a work at the tip. A bucket 4 that is an attachment for use is rotatably supported. The boom 7, the arm 5, the bucket 4, and the like constitute a work machine 7.

  The boom 6 is rotated by the boom cylinder 11, the arm 5 is rotated by the arm cylinder 10, and the bucket 4 is rotated by the bucket cylinder 9. In the crawler type traveling device 1, a driving sprocket 41 is disposed on one side of the front and rear, a driven sprocket 42 is disposed on the other side, and a crawler belt 43 is wound between the driving sprocket 41 and the driven sprocket 42. The drive sprocket 41 is driven by a hydraulic motor. Further, a turning motor is disposed between the turning frame 2 and the turntable bearing 17, and the turning frame 2 can be turned by the turning motor.

  The boom cylinder 11, the arm cylinder 10, and the bucket cylinder 9 are constituted by hydraulic cylinders, and hydraulic devices such as the cylinders 9, 10, 11 and the turning motor 45 and the traveling hydraulic motor 44 are referred to as hydraulic actuators. As shown in FIG. 2, the pilot valve is switched by the turning operation of the hydraulic operation levers 21 and 22, the traveling lever 25, the pedal, etc. disposed in the driving operation section 15, and the pilot valve is switched from the pilot valve to the main valve (direction control When the pressure oil is supplied from a hydraulic pump disposed in the bonnet 14 of the swivel base 2 through a hydraulic hose, the expansion and contraction drive and the rotation drive are performed.

  On both the left and right sides of the driver's seat 16, hydraulic operation levers 21 and 22 serving as pilot operation devices for operating the work implement 7 are provided, respectively. The hydraulic operation levers 21 and 22 are integrated with the lever stands 28 and 29, respectively. Attached, and from the lever stands 28 and 29, lock levers 23 and 24 for turning on / off (operating / inactivating) the operation of the work machine 7 by the hydraulic operation levers 21 and 22 are extended forward. .

  The lock levers 23 and 24 are configured to be pivotable up and down. When the lock levers 23 and 24 are pivoted downward, the working machine 7 can be operated by operating the hydraulic control levers 21 and 22, and the lock levers 23 and 24 are locked. When the levers 23 and 24 are turned upward, the work machine 7 is locked in a locked state (inoperable) in which the work implement 7 does not operate even if the hydraulic operation levers 21 and 22 are operated. Thus, the lock mechanism which locks the operation | movement of the working machine 7 by the hydraulic operation levers 21 and 22 by operating the left and right lock levers 23 and 24 up and down is configured.

  Furthermore, when the lock levers 23 and 24 are rotated downward and the working machine 7 can be operated by the hydraulic operation lever 22, the lock levers 23 and 24 are tilted forward to enter and exit the left and right sides. The entrances 19 and 19 are closed so that operators cannot get on and off, and when the lock levers 23 and 24 are rotated upward, the space of the entrances 19 and 19 is widened so that the operators can get on and off. However, it is also possible to provide a structure in which the entrance / exit is provided only on the left and right sides. In this case, the lock lever is disposed only on the side where the entrance / exit is provided.

  Next, a description will be given of the locking mechanism by starting and stopping the engine and operating the operation lever according to the present invention with reference to FIG. Hydraulic pumps 30 and 33 serving as hydraulic sources are connected to and driven on the output shaft of the engine 13, and the pressure oil discharged from the hydraulic pump 30 passes through a direction switching valve to a hydraulic actuator (hydraulic cylinders 9, 10, 11 and a hydraulic motor) are connected to each other so as to be able to feed oil. The hydraulic cylinders 9, 10, 11 and the hydraulic motor are each connected to a directional control valve (switching valve), and each pilot control valve is switched by operating a hydraulic control lever to control each directional control valve. Since the operation of the direction control valve and the hydraulic actuator is substantially the same, the operation of the boom cylinder 11 and the direction control valve and the on-off valve for controlling expansion and contraction of the boom cylinder 11 will be described.

  A directional control valve 31 is connected to the bottom side and the rod side of the boom cylinder 11 via hydraulic piping, respectively. The directional control valve 31 is constituted by a pilot-operated switching valve, and each pilot oil passage is hydraulically operated lever 21. Is connected to a pilot valve (remote control valve) 32 provided at the base of the valve. The pilot valve 32 is switched by the operation of the hydraulic operation lever 21, and the pressure oil from the hydraulic pump 33 connected to the engine 13 is sent to the pilot valve 32 via the on-off valve 34. By switching, the pilot oil can be fed to the pilot operating portion of the direction control valve 31. The boom cylinder 11 can be expanded and contracted by switching the direction control valve 31. However, the directional control valve 31 may be configured by an electromagnetic valve, and may be configured to switch by operating a solenoid of the electromagnetic valve by providing a switch or the like on the operation lever. In this case, the on-off valve 34 is interposed between the direction control valve 31 and the hydraulic pump 30.

  The on-off valve 34 is constituted by a two-position switching electromagnetic valve, and a solenoid 34a of the on-off valve 34 is connected to a switch 35 that serves as means for detecting the operation of the lock lever 23 described later. By switching the pressure oil from the hydraulic pump 33 to the pilot valve 32 and the direction of draining the pressure oil of the pilot valve 32 by the operation of the solenoid 34a, the boom cylinder 11 in which the on-off valve 34 serves as an actuator is switched. Switching means for switching between “operational” and “inoperational”.

  Thus, when the lock lever 23 is in the “operable” position, the solenoid 34 a is operated to switch the on-off valve 34, and the directional control valve 31 is operated when the pressure oil from the hydraulic pump 30 operates the pilot valve 32. The oil is fed to the pilot operating section and switched. Then, the pressure oil from the hydraulic pump 30 can be sent to the actuator (boom cylinder 11) via the direction control valve 31 to operate. Conversely, when the lock lever 23 is rotated to the “not operable” position, the solenoid 34 a is not activated, and the on-off valve 34 cannot feed the pressure oil from the hydraulic pump 33 to the pilot valve 32, and the hydraulic operation Even if the lever 21 (22) is operated, the direction control valve 31 cannot be switched and the actuator cannot be operated.

  Next, an electric circuit will be described. In FIG. 3, the key switch 36 is provided with each of an OFF terminal 36a, an ON terminal 36b, a START terminal 36c, and a common terminal 36d. By rotating the key, the common terminal 36d and the OFF terminal 36a or ON It can be connected to either the terminal 36b or the START terminal 36c, and the common terminal 36d is connected to a battery 37 serving as a power source.

  The ON terminal 36b is connected to one terminal (a power supply ON / OFF means side) of the two terminals 35a of the switch 35 for detecting the rotational position of the lock lever 23 (24), and the START terminal. The terminal 36c is connected to the other terminal 35b (starting restricting means side) of the switch 35. The switch 35 is integrally formed of a two-pole reversing switch, and the contact 35d is urged so as to always contact and close the terminal 35b by the urging force of the spring 35c. ”, The protrusion 23a provided at the base of the lock lever 23 pushes the contact point 35d to close the terminal 35a. Conversely, the terminal 35b is closed when the lock lever 23 is rotated to the “inoperable” position.

  The lock lever 23, the contact point 35d, and the terminal 35b serve as start restriction means. When the lock lever 23 is turned to the “operable” position, the terminal 35b is opened to start the key switch 36 as the start position ( Starting) is not possible. Further, the lock lever 23, the contact point 35d, and the terminal 35a serve as ON / OFF means for supplying electric power to the operating portion (solenoid 34a) of the switching means (open / close valve 34). ”Position, the contact 35a is closed (turned ON), and power is supplied to the solenoid 34a of the on-off valve 34 to operate it, so that pressure oil can be fed. In the “inoperable” position, the contact 35a is opened (OFF), power is not supplied to the solenoid 34a, the on-off valve 34 is not operated, and pressure oil is not sent to the pilot valve 32.

  The terminal 35a has a primary side (power supply side) connected to the ON terminal 36b of the key switch 36, and a secondary side (ground side) has a first input terminal 38a of a timer 38 serving as a delay means and a solenoid 34a of the on-off valve 34. The timer 38 is supplied with electric power from the battery 37, and is configured to be able to change the delay time (first delay time and second delay time described later) by the changing means 49, and the output side is the engine stop means 40. Is connected to the stop input. Therefore, when the key switch 36 is in the ON position and the lock lever 23 is rotated to the “operable” position, the terminal 35 a is closed and the on-off valve 34 is operated, and the actuator can be operated by operating the hydraulic control lever 21. It is said. When the lock lever 23 is in the “inoperable” position, the terminal 35a is opened, the on-off valve 34 is not operated, pressure oil is not supplied to the pilot valve 32, and the actuator operates even when the hydraulic operation lever 21 is rotated. It is not possible.

  The timer 38 is reset when the lock lever 23 is rotated to the “operable” position, the terminal 35a is closed, and the power is input to the first input terminal 38a. When the power is cut off by turning to the “impossible” position and an OFF signal is input to the first input terminal 38a, the timer 38 is activated and a stop signal is sent to the engine stop means 40 after a set time (first delay time). It outputs and stops the engine 13. That is, the timer 38 has the first input terminal 38a and the second input terminal 38b. The timer 38 is reset when an ON signal is input to the first input terminal 38a, and the timer is operated when an OFF signal is input. After the first delay time, the engine 13 is output from the output terminal to the engine stop means 40, and the engine 13 is stopped. If there is an ON signal within the first delay time, it is reset and the engine 13 remains in operation.

  A secondary side of the terminal 35b is connected to a second input terminal 38b of a timer 38 and a solenoid 39a of a relay 39 serving as an engine starting circuit (including a cell motor operating circuit and an ignition circuit). The relay 39 has a solenoid 39 a and a contact 39 b, and the contact 39 b is connected between the battery 37 and the cell motor 44. A pinion 45 is fixed to the output shaft of the cell motor 44, and the pinion 45 is engaged with a start gear 46 fixed to the flywheel of the engine 13. The contact point 39b is always “open”, and when the power is supplied to the solenoid 39a, the contact point 39b is “closed”. That is, when the key switch 36 is rotated to the START position when the lock lever 23 is in the “not operable” position, a current flows through the solenoid 39a, the contact 39b is closed, the cell motor 44 is driven, the flywheel is rotated, and the engine 13 is rotated. Start it.

  When an OFF signal is input to the second input terminal 38b of the timer 38, the timer is operated, and after the second delay time, the output is outputted to the engine stop means 40 to stop the engine 13, and within the second delay time. When the ON signal is input to the first input terminal 38a, the engine 13 is reset and the engine 13 remains in operation. That is, when the key switch 36 is rotated to the START position, the terminal 35a is closed when the lock lever 23 is in the “inoperable” position, the ON signal is input to the second input terminal 38b, and the cell motor 44 is simultaneously driven. When the engine 13 is started in this way, the key switch 36 is changed from the START position to the ON position, an OFF signal is input to the second input terminal 38b, and the timer 38 is activated.

  When the second delay time elapses, the output of the timer 38 is output to the engine stop means 40 to stop the engine 13, and the lock lever 23 is moved from the “not operable” position to the “enabled” position within the second delay time. When it rotates, the terminal 35a is closed, an ON signal is input to the first input terminal 38a, the timer 38 is reset, and the engine 13 can maintain the operating state.

  Further, when an ON signal is input to the second input terminal 38 b of the timer 38, the stop output from the timer 38 is released, and this ON signal is used as a release signal for the engine stop means 40. That is, the output of the timer 38 stops the engine stop means 40 after the first delay time elapses after the lock lever 23 is rotated to the “not operable” position and the first delay time elapses. On the other hand, in order to start the engine 13, the key switch 36 is rotated to the START position while the lock lever 23 is rotated to the “not operable” position, but the timer 38 is not reset unless the ON signal is input. The stopping means 40 remains in a stopped state, and the engine 13 cannot be started only by turning the key switch 36 to the START position. Therefore, when the key switch 36 is rotated to the START position when the lock lever 23 is in the “not operable” position, the ON signal when it is rotated to the START position is released so that the stop of the engine stop means 40 is released. An input signal is input to the second input terminal 38b of the timer 38, and the stop output of the timer 38 to the engine stop means 40 is released. Therefore, the rotation of the key switch 36 to the START position and the rotation of the lock lever 23 (24) to the “inoperable” position are the stop releasing means.

The operation of the above configuration will be described.
First, when the operator is seated on the work vehicle, both the lock levers 23 and 24 are rotated to the “inoperable” position. That is, the lock levers 23 and 23 are rotated so as to be able to pass through the entrance 19 by turning backward. In this state, as shown in FIG. 4, the terminal 35b of the switch 35 is closed, and when the key switch 36 is rotated to the START terminal 36c position, it is connected to the battery 37 serving as the starting power source, A stop release signal is output to the input terminal 38b, the stop of the engine stop means 40 is released, and the engine 13 becomes operable. At the same time, the solenoid 39a of the relay 39 is actuated, the contact 39b is closed, and electric power is supplied to the cell motor 44 to rotate and start the flywheel.

  At this time, if either or both of the lock levers 23 and 24 are rotated to the “operational” position, the relay 39 does not operate and the contact 39b is opened and the cell motor 44 cannot be driven. The engine 13 cannot be started. Therefore, even when the hydraulic control levers 21 and 22 are accidentally touched when starting the engine 13, the directional control valve 31 is not actuated because the on-off valve 34 is in a blocked state, and the actuator Is safe without operating.

When the engine 13 is started, the key switch 36 is turned to the ON position, the cell motor 44 is stopped, the OFF signal is input to the second input terminal 38b, and the timer 38 is activated. Then, as shown in FIG. 3, when working, the lock levers 23 and 24 are rotated forward to the “operable” position.
However, if the time from when the engine is started to when the lock lever is rotated from the “not operable” position to the “operable” position is not operated within the second set time, a stop signal is output from the timer 38 and the engine 13 To stop. In this way, useless driving of the engine 13 is prevented and fuel consumption is suppressed.

  Then, by turning the lock levers 23 and 24 to the “operational” position, the terminal 35a of the switch 35 is closed, and an ON signal is input to the first input terminal 38a of the timer 38, and the timer (second delay time). Is reset. At the same time, power is supplied to the solenoid 34a of the on-off valve 34 to turn it on, pressure oil is fed to the pilot valve 32 of the hydraulic operation levers 21 and 22, and the pilot of the direction control valve 31 is operated by the operation of the hydraulic operation levers 21 and 22. The direction control valve 31 can be switched by supplying oil to the operation unit. In this way, the work implement 7 can be operated by driving the actuator by operating the hydraulic operation levers 21 and 22.

  In the middle of the work, when the operator temporarily leaves the operation unit 15 to perform inspection or confirmation, when the lock lever 23 or 24 is lifted and rotated to the “inoperable” position, as shown in FIG. 35, the terminal 35a is opened, the on-off valve 34 is switched to the block position, and the direction control valve 31 is not switched even if the hydraulic operation levers 21 and 22 are operated. That is, even if the hydraulic control levers 21 and 22 are accidentally touched, the actuator does not operate. When the OFF signal is input to the first input terminal 38a of the timer 38, the timer 38 is activated and starts counting the first delay time. At this time, the engine 13 remains operating.

  When the operator returns to the driving control unit 15 within the first delay time set in the timer 38 and rotates the lock levers 23 and 24 to the “operable” position, the terminal 35a of the switch 35 is closed, and the timer 38 An ON signal is input to the first input terminal 38a, the timer (first delay time) is reset, the engine stop means 40 is not operated, the engine 13 remains operating, and the operation can be continued. Thus, when the ON signal is input to the first input terminal 38a, both the first delay time and the second delay time of the timer 38 can be reset, and the configuration for resetting can be simplified.

Further, when the operator cannot return to the driving control unit 15 and the first delay time set in the timer 38 has elapsed, a stop signal is sent from the timer 38 to the engine stop means 40 to stop the engine 13. In this way, wasteful fuel consumption can be suppressed. At this time, the lock lever 23 or 24 is in the “inoperable” position, and even if the hydraulic operation levers 21 and 22 are operated excessively, the actuator does not operate and is safe.
When the operation is performed again from the engine stop state, as described above, the key switch 36 is rotated and the engine 13 is restarted while the lock levers 23 and 24 are rotated to the “not operable” position. The operation for canceling the engine stop is unnecessary.

  In addition to the key switch 36 for starting the engine 13, a cell motor starting means for starting the engine can be provided. In this embodiment, the cell motor starting means is a start switch 48 using a push button switch, but a toggle switch, a seesaw switch, or the like may be used.

  The start switch 48 is provided on the lock lever 23 or 24. In this embodiment, the start switch 48 is provided on the grip 24a of the lock lever 24 as shown in FIG. The start switch 48 is disposed at the top, that is, the upper end of the grip portion 24a, but may be disposed on the side surface. With this configuration, after the engine is started, the lock lever 24 is operated to the release side, and the hydraulic operation levers 21 and 22 for operating the actuator are operated, so that the position of the start switch 48 can be easily understood and operation mistakes can be prevented. it can. In addition, operations after the engine is started can be performed immediately, and workability can be improved.

  The start switch 48 can also be attached to a boarding / alighting auxiliary member. That is, a boarding / unloading handle 50 is provided at the entrance / exit 19 to assist the boarding / alighting, and when the operator gets on / off, the boarding / unloading handle 50 is used to stabilize the body or to put a hand to lift the body. Is provided so as to protrude from the front surface of the vertical bar, for example, as shown in FIG. In this way, erroneous operation is prevented. However, the boarding / alighting auxiliary member is not limited to the handle 50, and the shape of the auxiliary member is not limited. It is also possible to do. Thus, since the start switch 48 is disposed in the vicinity of the driver's seat, the operation for re-operation can be facilitated, and the position of the start switch can be easily understood.

  In such a configuration, when the lock lever 23 (24) starts the engine 13 in the “not operable” position and the engine 13 is stopped and restarted after a predetermined time, or for checking the working machine, etc. When the seat 13 is temporarily removed from the seat, the lock lever 23 (24) is turned to the “inoperable” position and the engine 13 is stopped after a predetermined time and restarted. Press 48. By this pushing operation, as shown in FIG. 6, the electric power from the battery 37 operates the solenoid 39a of the relay 39 from the key switch 36 through the start switch 48 and the terminal 35b to close the contact 39b, and the cell motor 44 is turned on. It can be activated to start the engine. At this time, the lock lever 23 (24) is open at a position other than the “inoperable” position, the contact 35d is opened, the engine cannot be started, and erroneous operation can be prevented.

The side view which shows the turning work vehicle which has the erroneous operation prevention apparatus for work vehicles of invention. The top view of a driving | operation operation part. The hydraulic circuit diagram and electric circuit diagram of a misoperation prevention device for work vehicles. The hydraulic circuit diagram and electric circuit diagram at the time of engine starting similarly. The hydraulic circuit diagram and electric circuit diagram when the lock lever is set to “inoperable” during work. The hydraulic circuit diagram and electric circuit diagram of the state which operated the switch for starting. The perspective view which provided the start switch in the boarding / alighting auxiliary member.

Explanation of symbols

11 Boom cylinder (actuator)
13 Engine 23/24 Lock lever 34 On-off valve (switching means)
35 switch 35b terminal (start limiter)
35a ON / OFF means 36 Key switch 38 Timer (delay means)
48 Start switch (Cell motor starter)
50 Handle (Auxiliary member for getting on and off)

Claims (4)

  Provided with a lock lever that operates the switching means to switch between “activatable” and “non-operable” of the actuator that drives the work implement. When operated to the “inoperable” position after starting, the engine is stopped after a predetermined time by the delay means An operation error preventing apparatus for a work vehicle, characterized in that the work vehicle is provided with a cell motor starting means separately from the key switch.   2. The erroneous operation preventing apparatus for a work vehicle according to claim 1, further comprising start restriction means for allowing engine start only when the lock lever is in an “inoperable” position.   3. The erroneous operation preventing apparatus for a work vehicle according to claim 1, wherein an engine starting means is disposed on the lock lever. 3. The erroneous operation preventing device for a work vehicle according to claim 1, wherein an engine starting means is arranged on the auxiliary boarding member.

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