JP2016015936A - Working vehicle and method for controlling lifting device of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a working vehicle allowing an external operation switch to be operated at appropriate timing, and a method for controlling its lifting device.SOLUTION: The working vehicle includes a PTO shaft for supplying power to the working vehicle, and an external operation switch 80 for conducting adjustment of lifting devices 22 and 29. The external operation switch 80 is configured to be invalidated when the PTO shaft is in a rotating state. In a control method for the lifting device 22 and 29 of the working vehicle in which the PTO shaft supplies power to the working vehicle, and the external operation switch 80 performs adjustment of the lifting devices 22 and 29 at the outside, the external operation switch 80 is configured to be invalidated when the PTO shaft is in a rotating state.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a work vehicle and a method for controlling the lifting device, and more particularly to a work vehicle for operating the lifting device externally and a method for controlling the lifting device.

  When various operations are performed on farmland, a work vehicle such as a tractor to which various work machines are connected is used. The tractor is provided with a lifting device that lifts and lowers the connected working machines. The elevating device is operated by a switch provided in the cockpit of the tractor. Further, some tractors are provided outside the cockpit with a switch for operating the lifting device. The switch provided on the outside of the work vehicle of the work vehicle allows the work machine to be finely adjusted, such as when the work machine is moved up and down, such as when the work machine is moved up and down. It is arrange | positioned in the vicinity of the connection part.

  In Patent Document 1, an operation switch for raising and lowering a lift arm for raising and lowering a work is provided in a driving unit, and a state in which an ascending operation command for raising the lift arm is output and a lowering operation command for lowering the lift arm are output. And a lifting / lowering operation structure for a work vehicle provided with an external lifting switch near the work device connection part of the traveling machine, which displays a state in which both operation commands are not output, and operates a wire harness for the external lifting switch There is disclosed a lifting / lowering operation structure for a work vehicle that is configured to be connectable to an operation switch that displays three states arranged in a section. That is, when the lifting / lowering operation structure of the work vehicle disclosed in Patent Document 1 becomes impossible due to a failure, the lifting / lowering operation of the lift arm by the operation switch arranged in the driving unit becomes impossible. Connects to the deployed operation switch.

Japanese Patent No. 3570901

  By the way, in order to perform work smoothly outside the work vehicle, it is desired to reduce the chance that the operating part of the operating PTO (Power Take-Off) is exposed in front of the worker. However, Patent Document 1 does not describe any PTO shaft, and does not disclose or suggest any relationship between the PTO shaft and an external lift switch.

  As described above, the external lift switch is very useful during the detaching operation. However, since the worker is near the PTO moving part during the detachment work, there is a possibility that a malfunction may occur if the PTO shaft rotates unintentionally without the worker's intention. And the removal | desorption operation | work in the place where the PTO axis | shaft is rotating was not so appropriate.

  Accordingly, an object of the present invention is to provide a work vehicle capable of operating an external operation switch at an appropriate time, and a method for controlling the lifting device.

  In order to solve the above-described problems, the present invention provides a work vehicle including a PTO shaft that supplies power to a work machine, and an external operation switch that operates adjustment of the lifting device externally, and the external operation switch is the PTO shaft. Is configured to be invalid in a rotating state.

  Furthermore, the work vehicle according to the present invention further includes a PTO drive switch for switching the PTO shaft between an operating state and a non-operating state, and the external operation switch is configured so that the PTO shaft is brought into the operating state by the PTO drive switch. It is configured to be invalid when it is performed.

  Furthermore, the work vehicle according to the present invention further includes a changeover switch for switching between the rotation state and the stop state of the PTO shaft between interlocking and non-interlocking of the lifting device, and the external operation switch is The switching switch is configured to be ineffective when the lifting / lowering of the lifting / lowering device is brought into the interlocked state.

  Furthermore, the work vehicle according to the present invention further includes a light emitting unit, and is configured to disconnect an electrical connection to the light emitting unit when invalid.

  Further, according to the present invention, in the control method of the lifting device in a work vehicle in which the PTO shaft supplies power to the work machine and the external operation switch operates the adjustment of the lifting device externally, the external operation switch includes the PTO The shaft is ineffective when the shaft is rotated.

  Further, according to the control method of the lifting apparatus according to the present invention, the PTO drive switch switches the PTO shaft between the operating state and the non-operating state, and the external operation switch is operated by the PTO drive switch. It becomes invalid when it is in a state.

  Furthermore, the control method of the lifting device according to the present invention is such that the changeover switch switches the switching between the rotating state and the stopped state of the PTO shaft between interlocking and non-interlocking with the lifting and lowering of the lifting device. The switch is disabled when the switch is brought into the interlocked state with the lifting / lowering of the lifting / lowering device.

  Furthermore, the control method of the lifting device according to the present invention is characterized in that the electrical connection to the light emitting unit is disconnected when the external operation switch is disabled.

  According to the present invention, in a work vehicle including a PTO shaft that supplies power to a work machine and an external operation switch that operates adjustment of the lifting device externally, the external operation switch is invalid when the PTO shaft is in a rotating state. Therefore, it is possible to prevent the position or the like of the work machine from being changed in a situation where the worker is close to the working work machine. Furthermore, since the external operation switch does not function while the work machine is in operation, the opportunity for the operator to approach the external operation switch during operation of the work machine is reduced, and as a result, the operation unit of the PTO is approached. Opportunities can be reduced. Therefore, it is possible to provide a work vehicle that can operate the external operation switch in a timely manner.

  Further, according to the work vehicle of the present invention, the work vehicle further includes a PTO drive switch for switching the PTO shaft between the operating state and the non-operating state, and the external operation switch is operated when the PTO shaft is activated by the PTO drive switch. Since it is configured to be invalid, it prevents the position of the work machine from being changed in a situation where the worker is in close proximity to the working work machine even if the PTO shaft is not rotating. be able to. Furthermore, it is possible to prevent the PTO shaft from rotating unexpectedly by the external operation switch from the state where the PTO shaft is not rotating.

  Furthermore, according to the work vehicle of the present invention, the work vehicle further includes a changeover switch for switching between the rotation state of the PTO shaft and the stop state between interlocking and non-interlocking of the lifting device, and the external operation switch is a changeover switch. Because it is configured to be invalidated when it is interlocked with the lifting / lowering of the lifting / lowering device, the worker is close to the work machine under the situation where the PTO shaft rotates according to the lifting / lowering of the lifting / lowering device. In the situation, it can be prevented that the work machine operates, that is, the position of the work machine is changed and the PTO shaft is changed to the rotation state.

  Furthermore, according to the work vehicle of the present invention, the light emitting unit is further provided, and when it is disabled, the electrical connection to the light emitting unit is cut off, so that the external operation switch can be operated. The light emitting unit is turned on, and it is clear whether the external operation switch can be operated. Therefore, it is possible to provide a work vehicle that can operate the external operation switch at a more appropriate time.

  According to the present invention, in the method for controlling a lifting device in a work vehicle in which the PTO shaft supplies power to the work implement and the external operation switch operates the adjustment of the lifting device externally, the external operation switch is connected to the PTO shaft. Since it becomes invalid during the rotation state, it is possible to prevent the position of the work implement from being changed in a situation where the worker is close to the working work implement. Furthermore, since the external operation switch does not function while the work machine is in operation, the opportunity for the operator to approach the external operation switch while the work machine is in operation is reduced, and as a result, the opportunity to access the PTO shaft is reduced. Can be reduced. Therefore, it is possible to provide a method for controlling the lifting device in the work vehicle that can operate the external operation switch in a timely manner.

  Furthermore, according to the control method of the lifting device of the present invention, the PTO drive switch switches the PTO shaft between the operating state and the non-operating state, and the external operation switch has the PTO shaft operated by the PTO drive switch. Therefore, even if the PTO shaft is not rotating, it is possible to prevent the position or the like of the work machine from being changed in a situation where the worker is close to the working work machine in operation. Furthermore, it is possible to prevent the PTO shaft from rotating unexpectedly by the external operation switch from the state where the PTO shaft is not rotating.

  Furthermore, according to the control method of the lifting device of the present invention, the changeover switch switches the rotation state of the PTO shaft between the rotating state and the stopped state between interlocking and non-interlocking with the lifting and lowering of the lifting device. Since it becomes invalid when it is linked to the lifting / lowering of the lifting device by the changeover switch, work is performed in the situation where the worker is in close proximity to the work machine under the situation where the PTO shaft rotates according to the lifting / lowering of the lifting device. It is possible to prevent the machine from operating, that is, the position of the work machine from being changed and the PTO shaft from being changed to the rotating state.

  Furthermore, according to the control method of the lifting device of the present invention, when the external operation switch is disabled, the electrical connection to the light emitting unit is cut off, so that the light emitting unit is operated when the external operation switch can be operated. Illuminates to determine whether the external operation switch can be operated. Therefore, it is possible to provide a method for controlling the lifting device in the work vehicle that can operate the external operation switch at a more appropriate time.

It is a side view which shows the form with which the rotary cultivator as an example of a working machine was mounted | worn with the tractor as an example of the working vehicle which concerns on this embodiment. It is the top view in which the outline of the inside of a cabin and the periphery was shown. It is a top view of an operation panel. It is the block diagram in which the principal part structure of the adjustment mechanism of the raising / lowering apparatus was shown. It is the block diagram in which the principal part structure of the adjustment mechanism of another raising / lowering apparatus was shown. It is the block diagram in which the principal part structure of the adjustment mechanism of another raising / lowering apparatus was shown.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. FIG. 1 is a side view showing a form in which a rotary cultivator 30 as an example of a work machine is mounted on a tractor 10 as an example of a work vehicle according to the present embodiment. In the following, for convenience of explanation, the left side in FIG. 1 which is the traveling direction of the tractor 10 is defined as the front direction, and is orthogonal to the traveling direction and extends to the near side and the far side in FIG. The direction is the width direction.

  A tractor 10 illustrated in FIG. 1 includes an engine E, a battery BT, a generator (not shown), a radiator, a cooling fan, an air cleaner, and the like in a front bonnet 11 corresponding to the traveling direction of the airframe. The engine E, the battery BT, the generator, and the radiator are placed on the chassis 12. The generator is connected to the output portion of the engine E so as to operate using the engine E as power. The battery BT is connected to the generator. Electricity generated by the generator is stored in the battery BT.

  The tractor 10 includes front wheels 13 and 13 on the left and right of the front part, and rear wheels 14 and 14 on the left and right of the rear part, respectively. That is, the tractor 10 is supported so that the traveling machine body can travel by the wheels. Fenders 15 and 15 are provided so as to cover the left and right rear wheels 14 and 14 from above and from the inside of the tractor 10, respectively. The tractor 10 may have a configuration in which a crawler is used for the traveling device.

  A dashboard 16 is provided behind the bonnet 11 via an air cut plate (not shown). The dashboard 16 is provided with an instrument panel 40 that displays speed, fuel remaining amount, and the like. A steering column cover 17 is provided adjacent to the rear of the dashboard 16. A steering wheel 18 projects from the upper end of the steering column cover 17.

  A driver's seat 20 is provided behind the steering column cover 17 at a predetermined distance. The driver's seat 20 is disposed between the left and right fenders 15 and 15. The driver's seat 20 and the steering wheel 18 are covered with a cabin 19.

  The tractor 10 is not limited to the configuration having the cabin 19, and may be configured such that ROPS (Roll-Over Protective Structures) protrudes upward from the rear ends of the left and right fenders 15, 15. .

  A floor 21 is provided below the driver seat 20 and the dashboard 16. The floor 21 is for an operator to place his / her feet when getting on and off the tractor 10 or during driving.

  Below the driver's seat 20, a transmission case TM containing a transmission (not shown) such as a hydraulic continuously variable transmission mechanism, a gear transmission mechanism, or a PTO transmission mechanism is disposed. The transmission case TM is fixed to the rear part of the chassis 12. The transmission has a function of transmitting the power of the engine E to the rear wheels 14 and 14 with appropriate speed change.

  On the rear upper surface of the transmission case TM, for example, a hydraulic working machine lifting mechanism 22 for lifting and lowering a rotary tiller 30 mounted as a working machine is attached. Note that the working machine lifting mechanism 22 is not limited to a hydraulic type, and may be a mechanical type using a gear, for example, as long as the working machine can be raised and lowered.

  The rotary tiller 30 is connected to the tractor 10 via a three-point link mechanism including a pair of left and right lower links 23 and 23 and a top link 24 at the rear of the transmission case TM. The front end sides of the left and right lower links 23 are connected to the left and right side surfaces of the rear portion of the transmission case TM so as to be rotatable. A front end side of the top link 24 is rotatably connected to a rear portion of the work machine lifting mechanism 22. The PTO shaft 25 for transmitting the driving force of the engine E is linked to the engine E and protrudes rearward on the rear surface of the transmission case TM. The PTO shaft 25 has a function of supplying power to the rotary tiller 30 as a work machine.

  The work machine lifting mechanism 22 includes a pair of left and right lift arms 26 and 26 that are rotated by an actuator such as a lifting hydraulic cylinder (not shown). The left and right lift arms 26 and 26 are connected to the left and right lower links 23 and 23 via left and right lift rods 27 and 27, respectively. Each of the left and right lift arms 26 and 26 is configured such that the rotary tiller 30 moves up and down via the left and right lift rods 27 and 27 and the left and right lower links 23 and 23, respectively, by rotating. . As described above, the rotary cultivator 30 including the rotary cultivating claws is connected to the tractor 10 according to the present embodiment through the link mechanism so as to be movable up and down.

  A lift angle sensor 28 is provided at the shaft portion of the rotating left and right lift arms 26 and 26. The lift angle sensor 28 is configured to detect the rotation angle of the left and right lift arms 26 and 26 that raise and lower the link mechanism. For example, a potentiometer is used as the sensor.

  One of the left and right lift rods 27, 27, for example, the right lift rod 27 is attached with, for example, a hydraulic tilt control mechanism 29 for controlling the left and right tilt angle of the rotary tiller 30 as a working machine. The tilt control mechanism 29 is not limited to a hydraulic type, and may be a mechanical type using a gear, for example, as long as the working machine can be raised and lowered.

  The tilt control mechanism 29 includes, for example, a double-acting hydraulic cylinder and a piston rod. A part of the right lift rod 27 connected to the right lift arm 26 and the right lower link 23 is constituted by a hydraulic cylinder and a piston rod. Therefore, the length of the right lift rod 27 provided with the inclination control mechanism 29 is configured to be adjustable in expansion and contraction. And the horizontal attitude | position with respect to the tractor 10 of the rotary tiller 30, ie, a roll angle, is changed when the right lift rod 27 of the left-right lift rods 27 and 27 expands / contracts.

  At the rear of the fenders 15, 15, an external operation switch 80 for operating the adjustment of the lifting device externally is provided. Here, the lifting device includes a working machine lifting mechanism 22 and a tilt control mechanism 29. Details of the external operation switch 80 will be described later.

  The rotary tiller 30 illustrated in FIG. 1 is a side drive type. However, there is no problem even if the rotary tiller 30 as a working machine connected to the work vehicle according to the present embodiment is a center drive type, for example.

  The front part of the rotary tiller 30 is detachably connected to the lower link 31 and the top link 24 detachably connected to the left and right lower links 23 and 23 of the three-point link mechanism of the tractor 10. An upper connecting portion 32 is provided. A main beam (not shown) extending in a cylindrical shape in the width direction of the rotary tiller 30 is connected to the rear end of the lower connecting portion 31. On the other hand, a center case (not shown) located at a substantially central portion in the width direction of the rotary tiller 30 is rotatably connected to the lower end of the upper connecting portion 32. The main beam extends on both sides of the center case in the width direction.

  A drive input shaft 33 protrudes from the front surface of the center case. The drive input shaft 33 is interlocked with the PTO shaft 25 via a universal joint shaft 34 that can be expanded and contracted. The center case incorporates a power transmission mechanism such as a bevel gear (not shown) that transmits the power of the drive input shaft 33 extending in the front-rear direction in the width direction. The main beam has a built-in power transmission shaft that extends in the width direction and is rotatably coupled to the power transmission mechanism.

  The upper part of the transmission side case 35 extending substantially in the vertical direction is fixed to one end of the main beam extending in the left-right direction. A claw shaft rotor 36 extending in the width direction is rotatably provided at the lower portion of the transmission side case 35. A plurality of claws 37 extending radially in the radial direction are attached to the claw shaft rotor 36.

  Each of the output end of the power transmission shaft and the input end of the claw shaft rotor 36 protrudes to the inside of the transmission side case 35. Sprockets (not shown) are fixed to the output end of the power transmission shaft and the input end of the claw shaft rotor 36, respectively. The sprockets are interlocked and connected by an endless chain (not shown).

  In this way, in the rotary tiller 30, the power input from the PTO shaft 25 via the universal joint shaft 34 is transmitted to the drive input shaft 33, the power transmission mechanism, the power transmission shaft, the endless chain, and the claw shaft rotor 36. It is configured to be.

  A rotary main cover 38 is provided so as to surround the rotation locus L1 of the claw shaft rotor 36 and the claw 37. The rotary main cover 38 includes an upper surface cover disposed so as to cover the rotation locus L1 of the claw 37 in the width direction, and a pair of left and right side covers provided at both ends of the upper surface cover in the width direction. A rear cover 39 disposed so as to cover the rear of the rotation locus L1 of the claw 37 is attached to the rear end of the rotary main cover 38 via a hinge (not shown) extending in the width direction. The rear cover 39 is configured to be rotatable about a hinge.

  Next, the structure of the driver's seat 20 and its surroundings will be described. FIG. 2 is a plan view schematically showing the inside and the periphery of the cabin 19. As described above, the dashboard 16 is provided with the instrument panel 40, and the steering column cover 17 is provided with the substantially round steering 18 in a plan view.

  On the right side of the steering column cover 17 is provided an accelerator lever 50 for setting and holding the output rotational speed of the engine E. Below the accelerator lever 50 is provided a work implement lifting lever 71 for raising and lowering the work implement such as the rotary tiller 30 and the like by a single operation. On the left side of the steering column cover 17, a reverser lever (forward / reverse switching lever) 51 for switching the traveling direction of the tractor 10 between forward and reverse is provided. On the lower right side of the steering column cover 17, left and right brake pedals 52, 52 for braking the tractor 10 are provided. On the lower left side of the steering column cover 17, a clutch pedal 53 for operating a main clutch for interrupting power transmission from the engine E is provided.

  The entire upper surface of the floor 21 in front of the driver's seat 20 is substantially flat. An accelerator pedal 54 for controlling the rotational speed of the engine E or the vehicle speed is provided on the floor 21 on the right side of the steering column cover 17.

  On the left side of the driver's seat 20, an auxiliary transmission lever 55 is provided for switching the gear ratio of the traveling auxiliary transmission gear mechanism in the transmission case TM (see FIG. 1). A PTO speed change lever 56 that is connected to a PTO speed change mechanism in the transmission case TM (see FIG. 1) and switches the rotational speed of the PTO shaft 25 is provided below the left side of the driver seat 20.

  On the right side of the driver's seat 20, an armrest 57 is provided for an operator sitting on the driver's seat 20 to put his arms and elbows. The position of the armrest 57 is configured to be adjustable up and down and up and down. The front part of the armrest 57 is connected to a speed change mechanism in the transmission case TM (see FIG. 1), and a main speed change lever 58 for accelerating / decelerating the traveling speed of the tractor 10 and a stepless fine adjustment of the vehicle speed. For example, a speed adjustment dial 59 is provided.

  The armrest 57 is further provided with a work implement lifting switch 72 for raising and lowering the work implement such as the rotary tiller 30 and the like by a single operation. The work machine up / down switch 72 includes a rise button 72u and a down button 72d.

  The armrest 57 is further provided with a PTO drive switch 73 which is connected to a PTO clutch (not shown) and used for driving the PTO. The PTO drive switch 73 is configured to connect and disconnect the PTO clutch and switch the PTO shaft 25 between an operating state and a non-operating state. In other words, when the PTO shaft 25 is in an operating state, the PTO clutch is connected, and when the condition is satisfied, the PTO shaft 25 rotates at the rotational speed selected by the PTO speed change lever 56. Therefore, the operating state of the PTO shaft 25 includes both a rotating state and a stopped state. On the other hand, when the PTO shaft 25 is not in operation, the PTO shaft 25 stops. When the PTO drive switch 73 is configured to be in an activated state when it is turned to the left or right while being pressed, and to be inactivated when it is pressed once in the activated state, the PTO shaft 25 is instantaneously operated with a simple operation. Can be stopped and operability is good.

  The arm rest 57 is electrically connected to an actuator such as an elevating hydraulic cylinder of the work implement elevating mechanism 22 on the left side of the armrest 57, and the actuator is driven to operate the rotary tiller 30 or the like connected to the work implement elevating mechanism 22. A work machine up / down lever 74 for raising and lowering the machine is provided.

  The work implement up / down lever 74 may be configured to be used in combination with the work implement lift lever 71 or the work implement lift switch 72. For example, when the up button 72u is pressed, the work implement is raised to the uppermost position, and when the lower button 72d is pressed, the work implement is lowered to a height corresponding to the set position of the work implement up / down lever 74. It may be configured. Further, when the work implement up / down lever 74 is set at the uppermost position, the work implement may be configured not to be lowered when the work implement lift lever 71 or the work implement lift switch 72 is pressed. With these configurations, the work implement can be lowered to a desired position by a single operation of the work implement lift lever 71 and the work implement lift switch 72, and the operability is good.

  A PTO interlocking changeover switch 75 is provided behind the armrest 57. The PTO interlocking changeover switch 75 is a changeover switch for switching between the rotation state and the stop state of the PTO shaft 25 between interlocking and non-interlocking when the left and right lift arms 26 and 26 of the lifting device are lifted. Here, the non-interlocking is a setting in which, when the PTO shaft 25 is in the rotating state, the PTO shaft 25 is maintained in the rotating state regardless of the lifting / lowering of the working machine connected to the lifting device. On the other hand, the interlocking is a setting in which the PTO shaft 25 is automatically brought into a stopped state from a rotating state when the work machine is raised to a predetermined height or higher. The interlocking is set so that when the working machine is lowered below a predetermined height, the PTO shaft 25 is automatically rotated when the PTO shaft 25 is in an operating state.

  As an example in which the interlocking functions and the PTO shaft 25 is changed to a stopped state, when the work implement is raised to the highest position by the operation of the work implement lift lever 71, the work implement lift switch 72, etc. And when the working machine is raised to a predetermined height or more by the machine up / down lever 74. It should be noted that the front wheels 13 and 13 (see FIG. 1) have functions such as turning and lifting in which the work implement automatically rises when the front wheels 13 and 13 (see FIG. 1) are operated beyond a certain angle, In the case where the tractor 10 has, the interlocking may function similarly.

  In addition, the PTO interlocking changeover switch 75 may be configured to be switchable also with respect to the correspondence relationship between the operation of the clutch pedal 53 and the operation of the PTO shaft 25. In the present embodiment, when the clutch pedal 53 is depressed, the rotation of the PTO shaft 25 and the traveling of the tractor 10 are stopped at the same time, regardless of whether the above-described interlocking or non-interlocking of the PTO interlocking changeover switch 75 is selected. It is configured as follows. There, independence may be provided as a driving method of the PTO shaft 25. That is, when the position of the PTO interlocking switch 75 is independent, the operation of the clutch pedal 53 and the operation of the PTO shaft 25 are independent, so that the rotation of the PTO shaft 25 does not stop even when the clutch pedal 53 is depressed. It may be configured.

  As described above, the external operation switch 80 is provided behind the fenders 15 and 15. The external operation switch 80 is preferably provided on the outer side in the width direction of the fenders 15 and 15 from the viewpoint of easy operation even when the work implements are connected. The external operation switch 80 includes an external elevating switch 81 for raising and lowering the work implement such as the rotary tiller 30 and the horizontal tilt of the work implement relative to the tractor 10, that is, an external tilt for adjusting the roll angle. An adjustment switch 82. In the example of FIG. 2, an external lift switch 81 is provided on the left fender 15, and an external tilt adjustment switch 82 is provided on the right fender 15. It should be noted that the external lift switch 81 and the external tilt adjustment switch 82 may be provided in the opposite direction, and both may be provided in each of the left and right fenders 15 and 15.

  The external raising / lowering switch 81 has an up button 81u and a down button 81d. Each of the ascending button 81u and the descending button 81d is electrically connected to an actuator such as an elevating hydraulic cylinder of the work implement elevating mechanism 22, and the rotary connected to the work implement elevating mechanism 22 by driving the actuator. It is comprised so that working machines, such as the tilling apparatus 30, etc. may be raised / lowered. The work implement is raised when the up button 81u is pressed, and the work implement is lowered when the down button 81d is pressed.

  The external tilt adjustment switch 82 includes a shortening button 82u and an extension button 82d. Each of the shortening button 82u and the extension button 82d is electrically connected to the hydraulic cylinder of the tilt control mechanism 29, and is configured to tilt the working machine such as the rotary tiller 30 by expanding and contracting the right lift rod 27. Has been. When the shortening button 82u is pressed, the right lift rod 27 is shortened and the right and left tilt of the work implement is raised to the right. When the extension button 82d is pressed, the right lift rod 27 is extended and the left and right tilt of the work implement is tilted. It is configured to descend to the right.

  As described above, the configuration in which the external operation switch 80 is provided at the rear part of the fenders 15 and 15 makes it possible to easily adjust the height between the pins of the working machine and the hole positions of the left and right lower links 23 and 23. Can be attached and detached easily and reliably.

  The external operation switch 80 according to the present embodiment is configured to function by satisfying a predetermined condition. More specifically, the external operation switch 80 is configured to be disabled when the PTO shaft 25 is in a rotating state. That is, in a state where the PTO shaft 25 is rotating at least, it is prohibited to move the rotary tiller 30 up and down and to adjust the tilt by the external operation switch 80 located outside the tractor 10.

  The external operation switch 80 according to the present embodiment configured as described above prevents the position or the like of the rotary tiller 30 from being changed in a situation where an operator is in proximity to the operating rotary tiller 30. can do. Furthermore, since the external operation switch 80 does not function while the rotary tiller 30 is in operation, the opportunity for the operator to approach the external operation switch 80 while the rotary tiller 30 is in operation is reduced. The opportunity to approach the shaft 25 can be reduced. Therefore, it is possible to provide the tractor 10 that can operate the external operation switch 80 in a timely manner.

  Further, the external operation switch 80 may be configured to be invalid when the PTO shaft 25 is activated by the PTO drive switch 73. As described above, the operating state of the PTO shaft 25 includes a rotating state and a stopped state. In this way, in a state where the PTO shaft 25 can be rotated by an operation from the outside of the tractor 10, the position of the rotary tiller 30 is moved up and down by the external operation switch 80 positioned outside the tractor 10, and the inclination It may be prohibited to make adjustments.

  With the external operation switch 80 according to the present embodiment configured as described above, in the situation where the operator is in close proximity to the operating rotary tiller 30 even if the PTO shaft 25 is not rotating, the rotary tiller is used. It is possible to prevent the position of 30 and the like from being changed. Furthermore, it is possible to prevent the PTO shaft 25 from rotating unexpectedly by the external operation switch 80 from the state where the PTO shaft 25 is not rotating. For example, it is possible to prevent the claw shaft rotor 36 from rotating while the grass is being removed from the claw 37 of the rotary tiller 30.

  Further, the external operation switch 80 may be configured to be disabled when the PTO interlocking changeover switch 75 is linked to the lifting / lowering of the lifting device. The tractor 10 according to this embodiment is set to be interlocked by a PTO interlocking changeover switch 75, and automatically rotates when the PTO shaft 25 is in an operating state when the rotary tiller 30 is lowered below a predetermined height. It is configured to be in a state. In this way, in a situation where the PTO shaft 25 automatically rotates, the position of the rotary tiller 30 is moved up and down and the tilt is adjusted by the external operation switch 80 located outside the tractor 10. May be prohibited.

  In the situation where the operator is in close proximity to the rotary tiller 30 under the situation where the PTO shaft 25 rotates in accordance with the lifting and lowering of the lifting device by the external operation switch 80 according to the present embodiment configured as described above, the rotary tilling is performed. It is possible to prevent the device 30 from operating, that is, the position of the rotary tiller 30 and the like from being changed, and the PTO shaft 25 from being changed to the rotating state.

  The tractor 10 may further include a light emitting unit 90, and may be configured such that the electrical connection to the light emitting unit 90 is disconnected when disabled. 1 and 2 exemplify a form in which the light emitting unit 90 is provided above the external operation switch 80. The light emitting unit 90 may be provided in the vicinity of the external operation switch 80. The light emitting unit 90 may be provided in the gap between the buttons of the external operation switch 80. Furthermore, each button of the external operation switch 80 may have a form in which the light emitting unit 90 is built. In that case, a material having translucency is used for at least a part of each button.

  When the external operation switch 80 according to the present embodiment configured as described above can be operated, the light emitting unit 90 is turned on, and it is determined whether the external operation switch 80 can be operated. In particular, when the PTO shaft 25 is stopped, it is more effective when it is necessary to determine whether the external operation switch 80 can be operated. Therefore, it is possible to provide the tractor 10 that can operate the external operation switch at a more appropriate time. In addition, when the light emitting diode or the light bulb as the light emitting unit 90 is cut off due to the life or the like, or when the electric circuit is physically disconnected, the light emitting unit 90 is not turned on. Therefore, when an abnormality occurs in the light emitting unit 90, a safety failure occurs, so the external operation switch 80 of the tractor 10 including the light emitting unit 90 serves as a safety sensor.

  In addition, according to the structure of the light emission part 90 mentioned above, you may be comprised so that the function may be invalidated by disconnecting the electrical connection with respect to the contact of the external operation switch 80. FIG. By doing so, it is possible to obtain an external operation switch 80 that does not malfunction by a simple configuration and control method.

  An operation panel 60 is provided on the right side of the armrest 57. FIG. 3 is a plan view of the operation panel 60. 3 includes a depth setting dial 61, an inclination setting dial 62, an inclination control switch 63, a raising position setting dial 64, a depth control switch 65, a lower cushion setting dial 66, a link changeover switch 67, An auto sensitivity setting switch 68, a tilt manual lever 69, and the like are provided.

  The depth setting dial 61 sets the depth when the tilling depth of the rotary tiller 30 is automatically controlled. For example, the depth setting dial 61 is configured to rotate in the clockwise direction so that the depth of the rotary tiller 30 is set larger.

  The tilt setting dial 62 sets the left and right tilts when the tilt of the rotary tiller 30 is automatically controlled. For example, the tilt setting dial 62 rotates clockwise with reference to the center of rotation in the clockwise direction and rotation in the counterclockwise direction as a reference (horizontal), and the inclination of the rotary tiller 30 is lower right. It is configured to be a setting.

  The tilt control switch 63 switches the tilt control method of the rotary tiller 30. As a control method, there are horizontal automatic control, slope automatic control, and no control (manual). In the horizontal automatic control, the rotary tiller 30 is kept at a certain angle set by the tilt setting dial 62 with respect to the horizontal plane. Inclined land automatic control is to keep the rotary tiller 30 at a certain angle set by the tilt setting dial 62 with respect to the inclination of the ground. “Manual” means that the rotary tiller 30 is kept at a certain angle set by the tilt setting dial 62 with respect to the tractor 10. The tilt control switch 63 is configured to switch to horizontal automatic control, slope automatic control, and manual each time it is pressed, for example.

  The raising position setting dial 64 is for setting the maximum raising position of the rotary tiller 30. That is, the raising position setting dial 64 sets the uppermost position when the rotary tiller 30 is lifted by the work implement up / down lever 74, the work implement lift lever 71, the work implement lift switch 72, the back raising, the turning up and the like. To do. The raising position setting dial 64 is configured so that, for example, the maximum raising position of the rotary tiller 30 is set higher by rotation in the clockwise direction.

  The depth control switch 65 switches the control method of the tilling depth of the rotary tiller 30. As control methods, there are automatic depth control, automatic load control, and no control (manual). In the depth automatic control, the plowing depth of the rotary tiller 30 is maintained at a certain depth set by the depth setting dial 61. In the automatic load control, the plowing depth of the rotary tiller 30 is kept as much as possible at a certain depth set by the depth setting dial 61 and the plowing depth is controlled shallowly when the engine E is under a high load. . Note that the depth setting dial 61 is configured not to function manually. The depth control switch 65 is configured to switch to automatic depth control, automatic load control, and manual each time it is pressed, for example.

  The lower cushion setting dial 66 sets the height at which the lower cushion of the rotary tiller 30 starts to be effective when the lowering operation is performed by the work implement elevating lever 71 and the work implement elevating switch 72. This is a mechanism for preventing dashing or the like by slowing the descending speed of the rotary tiller 30 immediately before the ground contact. Here, dashing is a phenomenon that occurs when a tilling claw hits a hard ground field in particular, and a work vehicle that has received a reaction force of the excavation resistance of the tilling nail is strongly pushed forward. The lower cushion setting dial 66 is configured so that, for example, the position at which the lower cushion of the rotary tiller 30 starts to operate is set higher by rotation in the clockwise direction.

  The link changeover switch 67 selects the specifications of the three-point link mechanism (left and right lower links 23, 23) used for connecting the rotary tiller 30. More specifically, the link changeover switch 67 is switched depending on the difference between the width between the left and right lower links 23 and 23 and the position of the work machine mounting holes of the left and right lower links 23 and 23. And the correction | amendment according to the specification of the selected three-point link mechanism is performed, and the raising / lowering operation | movement of the rotary tiller 30 is changed. For example, each time the link changeover switch 67 is pressed, the (width, hole position) is (wide (718 mm), front), (wide, rear), (narrow (600 mm), front), and (narrow, It is configured to switch to (after).

  The auto sensitivity setting switch 68 switches the sensitivity of the auto rotary, that is, the operation sensitivity of the automatic tilling depth control. The automatic sensitivity setting switch 68 adjusts the operation sensitivity according to the hardness of the field, for example, and enables the tilling depth control with the operation sensitivity according to the field conditions. For example, when the ground of the field is hard, the sensitivity of the auto rotary is made insensitive. For example, each time the auto sensitivity setting switch 68 is pressed, the switch is switched between standard and insensitive.

  The tilt manual lever 69 is used to manually change and adjust the left and right tilt of the rotary tiller 30. Note that when the tilt of the rotary tiller 30 is automatically controlled, the tilt of the rotary tiller 30 is changed only while the tilt manual lever 69 is being operated. On the other hand, when the tilt of the rotary tiller 30 is not automatically controlled, the tilt of the rotary tiller 30 relative to the tractor 10 can be arbitrarily set by operating the tilt manual lever 69. The tilt manual lever 69 is configured such that, for example, when the tilt manual lever 69 is operated upward (backward from the operator), the tilt of the rotary tiller 30 is set to the lower right.

  Next, the control mechanism of the lifting device according to the present embodiment will be described in detail. FIG. 4 is a block diagram showing a main configuration of the adjustment mechanism of the lifting device. The tractor 10 further includes a control unit 100 that controls the operation of the lifting device. Various sensors and the like are connected to the input side of the control unit 100. The various sensors include an internal switch control device 101, an external switch control device 102, a lift angle sensor 28, a rear cover sensor 103, a rolling sensor 104, a rolling gyro sensor 105, a work machine position sensor 106, a PTO shaft rotation sensor 107, and the like. It is. Further, the work lifting mechanism 22, the tilt control mechanism 29, the light emitting unit 90, and the like are connected to the output side of the control unit 100.

  The control unit 100 reads input signals such as various setting values and detection values by various sensors and outputs control signals so as to control operations of the tractor 10 and the rotary tiller 30 as a work implement. It is configured. The control unit 100 is exemplified by a microcomputer including a CPU (Central Processing Unit) that performs arithmetic processing and control processing, a main storage device that stores data, an input circuit, an output circuit, a power supply circuit, and the like. . Various programs and the like for executing operations according to the present embodiment are stored in a main storage device (not shown) exemplified by a ROM (Read Only Memory) and a RAM (Random Access Memory). Note that data such as these various programs may be stored in an external storage device and read by the control unit 100.

  The internal switch control device 101 processes a signal of the internal operation switch 70 which is a switch group provided in the cabin 19. As the internal operation switch 70 having high relevance to the present embodiment, the above-described operation panel 60 (see FIG. 3), the work implement elevating lever 71, the work implement elevating switch 72, the PTO drive switch 73, the work implement up / down lever 74, PTO interlocking changeover switch 75, etc. (see FIG. 2).

  On the other hand, the external switch control device 102 processes a signal of the external operation switch 80 which is a switch group provided outside the tractor 10. As described above, the external operation switch 80 includes the external lift switch 81 and the external tilt adjustment switch 82 (see FIG. 2). The internal switch control device 101 and the external switch control device 102 according to the present embodiment are a CPU that controls the operation of the lifting device, a ROM that stores a control program related to the operation of the lifting device, and temporarily stores various information. It is comprised by the microcomputer etc. which provided RAM etc.

  The rear cover sensor 103 detects the rotation angle of the rear cover 39 that rotates up and down in accordance with fluctuations in the tilling depth of the claws 37 (see FIG. 1) of the rotary tiller 30. For example, a potentiometer is used as the rear cover sensor 103.

  The rolling sensor 104 detects the inclination angle of the tractor 10 and the rotary tiller 30 in the left-right direction. For example, a pendulum tilt sensor is used as the rolling sensor 104. Furthermore, as the rolling sensor 104, a capacitance type liquid level sensor that detects a change in liquid level due to inclination as a change in capacitance may be used.

  It is preferable that the rolling sensor 104 can detect at least the roll angle. However, the rolling sensor 104 may be a sensor that detects an omnidirectional inclination, or may be combined with a sensor that detects a pitch angle. In the case of a sensor that detects omnidirectional inclination, it is preferably disposed on the center line in the width direction of the tractor 100, that is, in the left-right direction, for example, on the transmission case TM. It is preferable that the position in the front-rear direction of the tractor 100 provided with the sensor for detecting the omnidirectional inclination is under the driver's seat 20. In the case of a sensor that detects omnidirectional inclination, a plurality of sensors may be provided.

  The rolling gyro sensor 105 detects the angular velocities in the left-right direction of the tractor 10 and the rotary tiller 30. As the rolling gyro sensor 105, for example, a gas rate type sensor is used.

  The work machine position sensor 106 detects a relative inclination angle of the rotary tiller 30 with respect to the tractor 10 in the left-right direction. As the work machine position sensor 106, for example, a potentiometer is used. Note that the above-described rear cover sensor 103 may include a tilt sensor that detects a tilt angle.

  The PTO shaft rotation sensor 107 detects the rotation of the PTO shaft 25 (see FIG. 1) and transmits this detection signal to the control device 100. As the PTO shaft rotation sensor 107, for example, an electromagnetic pickup sensor is used.

  The work implement lifting mechanism 22 includes, for example, a lift control electromagnetic valve 108, a drop control electromagnetic valve 109, and a single-acting lift hydraulic cylinder 110. These form a hydraulic circuit, and the elevating hydraulic cylinder 110 is connected to a hydraulic pump (not shown) driven by the engine E via the ascending control solenoid valve 108 and the descending control solenoid valve 109. The piston of the lifting hydraulic cylinder 110 is moved by the hydraulic oil supplied through the raising control electromagnetic valve 108 or the hydraulic oil discharged through the lowering control electromagnetic valve 109, whereby the left and right lift arms 26, 26 (see FIG. 1). Is configured to rise or fall. The hydraulic circuit is not limited to the above-described configuration, and may be configured so that the left and right lift arms 26 and 26 are raised or lowered. The ascending control solenoid valve 108 and the descending control solenoid valve 109 are connected to the output side of the control unit 100, and the control unit 100 is configured to switch each solenoid valve.

  The tilt control mechanism 29 includes, for example, a tilt control electromagnetic valve 111 and a double-acting tilt hydraulic cylinder 112. These form a hydraulic circuit, and the tilt hydraulic cylinder 112 is connected to a hydraulic pump (not shown) driven by the engine E via a tilt control electromagnetic valve 111. The piston of the tilt hydraulic cylinder 112 is moved by the hydraulic oil supplied to the piston rod side or the hydraulic oil supplied to the hydraulic cylinder side by switching the tilt control solenoid valve 111, so that the right lift rod 27 (FIG. 1) is configured to be shortened or extended. The hydraulic circuit is not limited to the above-described configuration, and may be configured so that the right lift rod 27 is shortened or extended. The tilt control electromagnetic valve 111 is connected to the output side of the control unit 100, and the control unit 100 is configured to switch the electromagnetic valve.

  As described above, the light emitting unit 90 notifies the operator whether or not the operation of the external operation switch 80 is possible. The light emitting unit 90 is configured by, for example, a light emitting diode or a light bulb. The tractor 10 according to the present embodiment may be configured such that the light emitting unit 90 is turned on when the external operation switch 80 can be operated. Thus, when the tractor 10 according to the present embodiment includes the light emitting unit 90 that operates according to whether the external operation switch 80 can be operated, it is clear that the external operation switch 80 can be operated. Can be recognized and can work efficiently.

  The light emitting unit 90 only needs to be able to notify the operator whether or not the external operation switch 80 can be operated. Therefore, the light emitting unit 90 may be configured by a notification device such as a buzzer or a speaker, or may be configured by a display unit such as a liquid crystal panel. The notification device and the display unit are configured to emit a sound or light according to a control signal from the control device 100 and notify the operator of whether or not the external operation switch 80 can be operated.

  Next, the control method of the lifting apparatus according to the present embodiment will be described in detail. First, the raising / lowering operation | movement of a working machine is explained in full detail.

  The control unit 100 uses an internal switch to set the depth control switch 65 (see FIG. 3) and the setting value of the depth setting dial 61 or the work implement up / down lever 74 (see FIG. 2) set by the operator. It is read through the control device 101 and the set tilling depth of the rotary tiller 30 is stored. On the other hand, the control unit 100 reads the output of the rear cover sensor 103 and stores the measured value of the tilling depth of the rotary tiller 30. And the control part 100 compares the memorize | stored setting tilling depth and the measured value of tilling depth.

  Further, the control unit 100 reads the setting of the link changeover switch 67 through the internal switch control device 101, reads the output of the lift angle sensor 28, and calculates the vertical position of the three-point link mechanism. Based on the difference between the set plowing depth and the measured value of the plowing depth, the control unit 100 switches the lifting control electromagnetic valve 108 or the lowering control electromagnetic valve 109 to expand and contract the lifting hydraulic cylinder 110 to rotate the rotary tilling device 30. Adjust the plowing depth to the set plowing depth.

  Next, the tilting operation of the work machine will be described in detail.

  The control unit 100 reads the setting of the tilt control switch 63 (see FIG. 3) and the set value of the tilt setting dial 62 or the tilt manual lever 69 set by the operator through the internal switch control device 101, and rotary tillage. The set inclination angle of the device 30 is stored. On the other hand, the control unit 100 reads the outputs of the rolling sensor 104, the rolling gyro sensor 105, and the work machine position sensor 106, and stores the measured values of the inclination angles of the tractor 10 and the rotary tiller 30. Then, the control unit 100 compares the stored set inclination angle with the actually measured value of the inclination angle.

  The control unit 100 expands and contracts the tilt hydraulic cylinder 110 by switching the tilt control electromagnetic valve 111 based on the difference between the set tilt angle and the measured value of the tilt angle, and sets the tilt angle of the rotary tiller 30 by setting the tilt angle. To match.

  Next, a method for controlling the invalidation of the external operation switch 80 will be described in detail.

  The internal operation switch 70 does not change in the operation result depending on whether the PTO shaft 25 is in a rotating state or a stopped state. For example, regardless of the state of the PTO shaft 25, when the lift button 72u is pressed, the rotary tiller 30 is raised to the uppermost position, and when the tilt manual lever 69 is operated downward, the rotary tiller 30 is tilted. It becomes more upper right. On the other hand, the external operation switch 80 according to the present embodiment is controlled so that its function is invalidated corresponding to the state of the PTO shaft 25.

  The control unit 100 reads the output from the PTO shaft rotation sensor 107 and determines whether the PTO shaft 25 is in a stopped state or a rotating state. When it is determined that the PTO shaft 25 is in the stopped state, the control unit 100 reads the operation of the external operation switch 80 through the external switch control device 102 and controls the lifting device, similarly to the internal operation switch 70. For example, when the PTO shaft 25 is in a stopped state, the rotary tiller 30 is raised when the lift button 81u (see FIG. 2) is pressed, and the rotary tiller 30 is more inclined when the extend button 82d is pressed. Lower right. When it is determined that the PTO shaft 25 is in a stopped state, the control unit 100 may perform control so that the light emitting unit 90 is turned on.

  On the other hand, when it is determined that the PTO shaft 25 is in the rotating state, the control unit 100 performs control so that the operation output of the external operation switch 80 read through the external switch control device 102 becomes invalid. For example, when the PTO shaft 25 is in a rotating state, the rotary tiller 30 does not descend even if the lowering button 81d is pressed, and the inclination of the rotary tiller 30 does not become the upper right even if the shortening button 82u is pressed. . If it is determined that the PTO shaft 25 is in a rotating state, the control unit 100 may control the light emitting unit 90 to be turned off.

  In the present embodiment, it is sufficient that the external operation switch 80 does not function when the PTO shaft 25 is rotating. Therefore, even when the control unit 100 sends a signal to the external switch control device 102 when the PTO shaft 25 is rotating, the external switch control device 102 performs control so that the operation output of the external operation switch 80 is not passed. good. Further, when the PTO shaft 25 is in a rotating state, the external switch control device 102 may perform control so as not to accept the operation output of the external operation switch 80. Furthermore, a switch, a relay, or the like may be provided between the external operation switch 80 and the external switch control device 102 so that the continuity is cut off when the PTO shaft 25 is in a rotating state.

  By such a method for controlling the lifting device in the tractor 10, it is possible to prevent the position of the rotary tiller 30 from being changed in a situation where an operator is in proximity to the operating rotary tiller 30. . Furthermore, since the external operation switch 80 does not function while the rotary tiller 30 is in operation, the opportunity for the operator to approach the external operation switch 80 while the rotary tiller 30 is in operation is reduced. The opportunity to approach the shaft 25 can be reduced. Therefore, it is possible to provide a method for controlling the lifting device in the tractor 10 that can operate the external operation switch 80 in a timely manner.

  Further, the external operation switch 80 may be controlled to be invalid when the PTO shaft 25 is activated by the PTO drive switch 73. As described above, the operating state of the PTO shaft 25 includes a rotating state and a stopped state. In this way, in a state where the PTO shaft 25 can be rotated by an operation from the outside of the tractor 10, the position of the rotary tiller 30 is moved up and down by the external operation switch 80 positioned outside the tractor 10, and the inclination It may be prohibited to make adjustments.

  FIG. 5 is a block diagram showing the main configuration of an adjustment mechanism of another lifting device. In the control method of the lifting device having the main configuration illustrated in FIG. 5, a PTO drive switch 73 is used instead of the PTO shaft rotation sensor 107 in FIG. 4.

  The control unit 100 reads the setting of the PTO drive switch 73 and determines whether the PTO drive switch 73 is in the off state or the on state. Here, when the PTO drive switch 73 is in the off state, that is, the PTO shaft 25 is in an inoperative state, and when the PTO drive switch 73 is in an on state, that is, the PTO shaft 25 is in an activated state. When it is determined that the PTO drive switch 73 is in the OFF state, the control unit 100 controls the operation of the external operation switch 80 as in the case where it is determined that the PTO shaft 25 is in the stop state. Read through 102 to control the lifting device. When it is determined that the PTO drive switch 73 is in the off state, the control unit 100 may perform control so that the light emitting unit 90 is turned on.

  On the other hand, when it is determined that the PTO drive switch 73 is in the on state, the control unit 100 performs control so that the operation output of the external operation switch 80 read through the external switch control device 102 becomes invalid. For example, when the PTO drive switch 73 is in the on state, the rotary tiller 30 does not descend even if the lowering button 81d is pressed, and the inclination of the rotary tiller 30 is more upper right even if the shortening button 82u is pressed. Don't be. If it is determined that the PTO drive switch 73 is in the on state, the control unit 100 may control the light emitting unit 90 to be turned off.

  In the control method of the lifting device with the main configuration illustrated in FIG. 5, it is sufficient that the external operation switch 80 does not function when the PTO drive switch 73 is in the on state. Examples of the control method for preventing the external operation switch 80 from functioning and the control method by the external switch control device 102 are the same as described above.

  By such a method for controlling the lifting device in the tractor 10, the position of the rotary tiller 30, etc. in a situation where an operator is in proximity to the operating rotary tiller 30 even if the PTO shaft 25 is not rotating. Can be prevented from being changed. Furthermore, it is possible to prevent the PTO shaft 25 from rotating unexpectedly by the external operation switch 80 from the state where the PTO shaft 25 is not rotating.

  Further, the external operation switch 80 may be controlled so as to be disabled when the PTO interlocking changeover switch 75 is linked to the lifting / lowering of the lifting device. The tractor 10 according to this embodiment is set to be interlocked by a PTO interlocking changeover switch 75, and automatically rotates when the PTO shaft 25 is in an operating state when the rotary tiller 30 is lowered below a predetermined height. It is controlled to be in a state. In this way, in a situation where the PTO shaft 25 automatically rotates, the position of the rotary tiller 30 is moved up and down and the tilt is adjusted by the external operation switch 80 located outside the tractor 10. May be prohibited.

  FIG. 6 is a block diagram showing the configuration of the main part of another adjustment mechanism of the lifting device. In the control method of the lifting device with the main configuration illustrated in FIG. 6, a PTO interlocking changeover switch 75 is used in addition to the main configuration in FIG. 4.

  The control unit 100 reads the output from the PTO shaft rotation sensor 107 and determines whether the PTO shaft 25 is in a stopped state or a rotating state. When it is determined that the PTO shaft 25 is in the rotating state, the control unit 100 performs control so that the operation output of the external operation switch 80 read through the external switch control device 102 becomes invalid. If it is determined that the PTO shaft 25 is in a rotating state, the control unit 100 may control the light emitting unit 90 to be turned off.

  On the other hand, when it is determined that the PTO shaft 25 is in the stopped state, the control unit 100 reads the setting of the PTO interlocking changeover switch 75, and the PTO interlocking changeover switch 75 is not interlocked or interlocked. Determine whether. When it is determined that the PTO interlocking switch 75 is interlocked, the control unit 100 performs control so that the operation output of the external operation switch 80 read through the external switch control device 102 becomes invalid. When it is determined that the PTO shaft 25 is in a stopped state and the PTO interlocking changeover switch 75 is interlocked, the control unit 100 may perform control so that the light emitting unit 90 is turned off.

  On the other hand, when it is determined that the PTO interlocking changeover switch 75 is not interlocked, the control unit 100 reads the operation of the external operation switch 80 through the external switch control device 102 and controls the lifting device. When it is determined that the PTO shaft 25 is in a stopped state and the PTO interlocking changeover switch 75 is not interlocked, the control unit 100 may perform control so that the light emitting unit 90 is turned on.

  In the lifting device control method having the main configuration illustrated in FIG. 6, the external operation switch 80 must function unless the PTO shaft 25 is stopped and the PTO interlocking switch 75 is not interlocked. It ’s fine. Examples of the control method for preventing the external operation switch 80 from functioning and the control method by the external switch control device 102 are the same as described above.

  By such a control method of the lifting device in the tractor 10, the rotary tiller 30 operates in a situation where an operator is in close proximity to the rotary tiller 30 in a state where the PTO shaft 25 rotates in accordance with the lifting of the lifting device. In other words, it is possible to prevent the position or the like of the rotary tiller 30 from being changed and the PTO shaft 25 from being changed to a rotating state.

  Further, as described above, the external operation switch 80 has a built-in light-emitting unit 90 in any of the adjustment mechanisms of the lifting device, and is controlled so that the electrical connection to the light-emitting unit 90 is disconnected when disabled. May have been. When the external operation switch 80 according to this embodiment controlled in this way can operate the external operation switch 80, the light emitting unit 90 is turned on, and it is determined whether the external operation switch 80 can be operated. In particular, when the PTO shaft 25 is stopped, it is more effective when it is necessary to determine whether the external operation switch 80 can be operated. Therefore, it is possible to provide a method for controlling the lifting device in the tractor 10 that can operate the external operation switch at a more appropriate time. In addition, when the light emitting diode or the light bulb as the light emitting unit 90 is cut off due to the life or the like, or when the electric circuit is physically disconnected, the light emitting unit is not turned on. Therefore, when an abnormality occurs in the light emitting unit 90, a safety-side failure occurs. Therefore, the external operation switch 80 incorporating the light emitting unit 90 serves as a safety sensor.

  The work vehicle according to the present invention is not limited to the combination of the tractor 10 and the rotary tiller 30. For example, the vehicle main machine and the work machine are combined like a transplanter and a seedling planting device. In other words, the present invention can be applied to any vehicle that needs to adjust the height and inclination of the working machine with respect to the vehicle main unit.

10 Tractor (work vehicle)
DESCRIPTION OF SYMBOLS 15 Fender 20 Driver's seat 22 Lifting mechanism for work machines 25 PTO shaft 26 Lift arm 27 Left and right lift rod 28 Lift angle sensor 29 Tilt control mechanism 30 Rotary tillage device (work machine)
70 Internal operation switch 71 Work implement lift lever 72 Work implement lift switch 72u Up button 72d Down button 73 PTO drive switch 75 PTO interlocking switch 80 External operation switch 81 External lift switch 81u Up button 81d Down button 82 External tilt adjustment switch 82u Shortening Button 82d Extension button 90 Light emitting unit 100 Control unit 101 Internal switch control device 102 External switch control device 108 Lift control solenoid valve 109 Drop control solenoid valve 110 Lift hydraulic cylinder 111 Tilt control solenoid valve 112 Tilt hydraulic cylinder

Claims (8)

A PTO shaft that supplies power to the work implement;
In a work vehicle including an external operation switch for operating the adjustment of the lifting device externally,
The work vehicle, wherein the external operation switch is configured to be invalid when the PTO shaft is in a rotating state. A PTO drive switch for switching the PTO shaft between an operating state and a non-operating state;
2. The work vehicle according to claim 1, wherein the external operation switch is configured to be disabled when the PTO shaft is brought into the operating state by the PTO drive switch. A switching switch for switching the rotation state of the PTO shaft and the stop state between interlocking and non-interlocking of the lifting device;
The said external operation switch is comprised so that it may become the said invalid, when it is in the said interlocking | linkage state with the said raising / lowering of the said raising / lowering apparatus by the said changeover switch. The work vehicle according to the item. Further comprising a light emitting section,
The work vehicle according to any one of claims 1 to 3, wherein an electrical connection to the light emitting unit is cut when the invalidation is performed. The PTO shaft supplies power to the work implement,
In the control method of the lifting device in the work vehicle in which the external operation switch operates the adjustment of the lifting device externally,
The method for controlling an elevating device, wherein the external operation switch is disabled when the PTO shaft is in a rotating state. A PTO drive switch switches the PTO shaft between an operating state and a non-operating state;
The method for controlling the lifting device according to claim 5, wherein the external operation switch is disabled when the PTO shaft is brought into the operating state by the PTO drive switch. A change-over switch switches between the rotation state and the stop state of the PTO shaft between interlocking and non-interlocking with the lifting and lowering of the lifting device;
The lifting device according to any one of claims 5 to 6, wherein the external operation switch is disabled when the changeover switch is set to the interlocking state with the lifting / lowering of the lifting device. Control method. The method for controlling an elevating device according to any one of claims 5 to 7, wherein when the external operation switch is disabled, electrical connection to the light emitting unit is disconnected.

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