JP6238752B2 - Work vehicle - Google Patents

Description

  The present invention relates to a work vehicle including a PTO (power take off) mechanism that transmits power to a work device that is connected to an airframe via a link mechanism so as to be movable up and down. A PTO clutch is interposed in the PTO mechanism.

  Patent Document 1 discloses an automatic control in which the manual operation switching means is switched to automatic operation so that the rotation of the PTO shaft stops when the working device is raised during traveling and the PTO shaft rotates when the working device is lowered. An equipped tractor is disclosed. Further, the automatic control of the PTO incorporates a check function that prevents the PTO shaft from rotating unless the manual operation switching means is switched from automatic operation to manual operation when traveling is stopped. It is assumed that the raising / lowering operation of the working device and the switching operation of the switching means are performed by a driver seated in the driver's seat.

JP 59-18024 A (FIGS. 1 and 3)

  In order to check the connection state and the lifted state of the work device, a work vehicle has appeared that allows a driver who has moved out of the machine body to raise and lower the work device using an operation tool provided outside the machine body. Even in a work vehicle equipped with such a lifting operation tool operated from the outside of the machine body, it is desirable that a check function as disclosed in Patent Document 1 is appropriately incorporated.

A work vehicle according to the present invention includes a machine body, a link mechanism that connects a work device to the machine body so as to be movable up and down, a lift actuator that lifts and lowers the link mechanism, an internal lifting operation tool that is manually operated from a driver's seat, and an external body An external lifting operation tool that is manually operated from the PTO mechanism, a PTO mechanism that transmits power to the work device, a PTO clutch provided in the PTO mechanism, and a PTO clutch operation tool that is manually operated to turn the PTO clutch on and off. Elevating operation command for raising and lowering the working device in response to operation of the internal elevating operation tool and elevating operation command for raising and lowering the working device in response to operation of the external elevating operation tool PTO control that outputs an on / off operation command for the PTO clutch in response to an operation of the operating device control unit and the PTO clutch operating tool If the predetermined height of the external and PTO forcible stop control unit for commanding the output of cut operation command in response to the lifting operation tool of operation with respect to the PTO clutch to the PTO control unit, the working device by the inner lifting operation member In response to the above-described increase, the PTO clutch is operated to output a disconnection operation command, and in response to a decrease of a predetermined height or less, the PTO clutch is input to the PTO clutch. An ascending PTO control unit that stops the ascending PTO control until the PTO clutch manipulator is manually operated in response to the operation of the external elevating manipulator .

According to this configuration, the lifting / lowering operation on the work device is not only operated by the driver seated in the driver's seat using the internal lifting / lowering operation tool, but also by the driver or the worker who has gone outside the machine body. Operation is also possible using. In addition, when the external lifting / lowering operation tool is operated, a check function for forcibly disengaging the PTO clutch works, so that the person operating the external lifting / lowering tool outside the machine moves up and down while driving. It is not adversely affected by the device. Further, in this configuration, the power transmission to the working device is automatically controlled so that when the working device is raised, the PTO clutch is disconnected and when the working device is lowered again, the PTO clutch is connected. Thereby, when the working device is a tilling device or the like, inconveniences such as soil being scattered by the rotary rotary at the time of ascent and inconvenience of entering the ground in a state where the rotary is stopped are avoided. Even under such automatic control, the PTO clutch is not connected even if the working device is lowered below a predetermined height by operating the external lifting / lowering operation tool. Inconveniences such as driving the working device are also avoided. Even in this case, once the external lifting / lowering operation tool is operated, the connection of the PTO clutch, that is, the driving of the work device is prohibited unless the PTO clutch operation tool is manually operated by returning to the driver's seat.

  In the present invention, the PTO clutch is forcibly disconnected by the operation of the external lifting operation tool, but the return (connection of the PTO clutch) must be carefully performed. That is, it is necessary to support the operator's intention to reconnect the PTO clutch in order to reconnect the PTO clutch. From this, in one of the preferred embodiments of the present invention, the PTO forced stop control unit releases the disconnection operation command for the PTO clutch when the PTO clutch operating tool is manually operated. In this configuration, once the PTO clutch is disconnected by the operation of the external small operation tool, it is necessary to return to the driver's seat and manually operate the PTO clutch operation tool in order to reconnect the PTO clutch. Willingness to reconnect the PTO clutch.

  In one preferred embodiment of the present invention, a target value calculation unit that calculates an operation target value corresponding to the height of the working device from an operation displacement of the internal lifting operation tool is provided, and the PTO automatic control at the time of ascent The unit executes the ascending PTO control based on the operation target value. In this configuration, instead of actually measuring the height of the working device and executing the ascent PTO control based on the actually measured value, the height of the working device calculated from the operation displacement of the internal lifting operation tool, that is, Based on the operation target value for the control device, it is determined whether the working device is raised above a predetermined height or the working device is lowered below a predetermined height, so that quicker control is possible.

  The external lifting / lowering operation tool is an operating tool for operating the lifting / lowering operation while viewing the state of the working device from the outside of the machine body. Furthermore, considering the case where the worker moves around the working device, it is still more convenient to configure the external lifting operation tool as a remote control operating body that can be carried around the working device. As such a remote control operation body, it is advantageous in terms of cost if a mobile phone such as a smartphone having a wireless communication function such as WIFI is used. In that case, the remote control operation function is constructed by an application program installed in the mobile phone.

  In working devices such as a tillage device, there is a request to artificially position the tillage device at an arbitrary height, and at the same time when the aircraft is turning, the ascent to a preset ascent position and a preset descent position are established. There is a desire to perform a descent of one-touch. In order to satisfy this demand, in one preferred embodiment of the present invention, the internal lifting operation tool is composed of a lifting position adjusting operation body and a forced lifting operation body. The working device is positioned at a corresponding height position, and the forcible raising / lowering operating body raises the working device to a previously set raised position and a lowering operation signal to lower the working device from the upper position to the original position. To produce.

It is a schematic diagram explaining the basic composition of the present invention. It is a side view of a tractor which is one of the concrete embodiments of the work vehicle by the present invention. It is a perspective view which shows the rotary tilling apparatus connected with the rear part of the tractor via the link mechanism. It is a schematic diagram explaining the input device to a control apparatus, and the output device from a control apparatus. It is a functional block diagram which shows the function of a control apparatus. It is a chart figure which shows raising / lowering control and PTO control. It is a functional block diagram which shows the function of the control apparatus in another embodiment.

  Before describing a specific embodiment of a work vehicle according to the present invention, the basic principles of lifting control and PTO control for a work device, which characterize the present invention, will be described with reference to FIG. A core control element in the elevation control and the PTO control for the work device 3 is a computer-based control device 5 also called an ECU. The work device 3 is connected to a machine body of the work vehicle via a link mechanism 6 so as to be movable up and down. The link mechanism 6 moves up and down by the lift actuator 60. Power is transmitted to the work apparatus 3 from the machine body via a PTO (Power Take Off) mechanism 4. The PTO mechanism 4 is provided with a PTO clutch 41 that cuts off power to the working device 3.

  Around the driver's seat of the work vehicle, one or a plurality of internal lifting / lowering operating tools 2 and a PTO clutch operating tool 40 which are manually operated by a driver sitting in the driver's seat are arranged. The internal elevating operation tool 2 is used for elevating the working device 3. The PTO clutch operating tool 40 is used to turn on and off the PTO clutch 41 (power transmission and interruption). Further, an external lifting operation tool 30 that is manually operated to raise and lower the work device 3 from the outside of the machine body is provided at a position that can be operated by a worker (driver) outside the machine. The operation input by the internal elevating operation tool 2, the external elevating operation tool 30, and the PTO clutch operation tool 40 is converted into an electrical signal via a sensor or an electric switch and sent to the control device 5 as an operation input signal.

  In the control device 5, an operation command generation unit 51, a lifting operation device control unit 52, an ascending PTO automatic control unit 53, a PTO forced stop control unit 54, and a PTO control unit 55 are constructed by software and / or hardware. Has been. The operation command generation unit 51 generates an elevating operation command based on an operation input signal sent based on the operation of the internal elevating operation tool 2 or the external elevating operation tool 30. In response to the lifting / lowering operation command received from the motion command generating unit 51, the lifting / lowering operation device control unit 52 outputs a lifting / lowering operation control signal for lifting and lowering the work device. That is, the lifting / lowering operation device control unit 52 outputs a lifting / lowering operation control signal for lifting / lowering the work device 3 in response to the operation of the internal lifting / lowering operation tool 2 to raise and lower the lifting / lowering actuator 60, and In response to the operation, an elevating operation control signal for elevating the work device 3 is output, and the elevating actuator 60 is lowered. The PTO controller 55 outputs an on / off operation control signal for the PTO clutch 41 using an operation input signal sent based on the operation of the PTO clutch operating tool 40 as an on / off operation command.

  The PTO forced stop control unit 54 sends a cutting operation command for the PTO clutch 41 to the PTO control unit 55 in response to an operation input signal sent based on the operation of the external lifting operation tool 30. As a result, the PTO controller 55 outputs a disconnection operation control signal to the PTO clutch 41. That is, when the external lifting / lowering operation tool 30 is operated, the power to the work device 3 is forcibly cut off. This forced PTO power cutoff is maintained until the PTO clutch operating tool 40 is manually operated. That is, when the PTO clutch operating tool 40 is manually operated, the PTO forced stop control unit 54 releases the disconnection operation command for the PTO clutch sent to the PTO control unit 55.

  The ascending PTO automatic control unit 53 switches to the PTO control unit 55 to disengage the PTO clutch 41 in response to the manual operation of the internal lifting operation tool 2 to raise the working device 3 to a predetermined height or higher. An operation command is output. Further, the PTO automatic control unit 53 at the time of ascent raises the PTO clutch 41 in response to the operation of the internal elevating operation tool 2 so that the work device 3 once raised above the predetermined height is lowered below the predetermined height. In order to enter, the PTO controller 55 is entered and an operation command is output. However, when the external lifting operation tool 30 is operated, the PTO automatic control unit 53 at the time of rising responds to this operation, and the PTO corresponding to the lifting position of the work device 3 until the PTO clutch operation tool 40 is manually operated. PTO control at the time of ascent that is on / off control of the clutch 41 is stopped.

  Next, a tractor which is one of the specific embodiments of the work vehicle according to the present invention will be described with reference to the drawings. FIG. 2 is a side view of a tractor equipped with a rotary tiller as a working device, and FIG. 3 is a perspective view of the rotary tiller.

  As shown in FIG. 2, an engine 11 is mounted on the front portion of the tractor body 1 supported by the front wheels 1a and the rear wheels 1b, and a transmission case 12 is mounted on the rear portion. A rotary tiller 3 is mounted behind the machine body 1 via a link mechanism 6 so as to be movable up and down. This tractor is of a four-wheel drive type, and the power of the engine 11 is transmitted to the front wheels 1a and the rear wheels 1b via a traveling transmission (not shown) built in the transmission case 12. The power of the engine 11 is transmitted to the PTO shaft 42 via the PTO clutch 41 built in the transmission case 12 and also transmitted to the rotary tiller 3 via the transmission shaft 43. Here, the PTO mechanism 4 includes a PTO clutch 41, a PTO shaft 42, and a transmission shaft 43.

  As shown in FIGS. 1 and 2, the link mechanism 6 includes a top link 61, a pair of left and right lower links 62, a pair of left and right lift arms 63, and a lift rod 64. Further, a lifting hydraulic cylinder 60 as a lifting actuator for lifting and lowering the rotary tiller 3 connected to the link mechanism 6 and a rolling hydraulic cylinder 65 as a rolling actuator for adjusting the rolling posture of the rotary tiller 3 are also incorporated in the link mechanism 6. It is.

  The top link 61 and the right and left lower links 62 are supported by the transmission case 12 so as to be swingable up and down. The elevating hydraulic cylinder 60 is a single-acting type, and is linked to the top link 61 via a lever mechanism. The right and left lift arms 63 and the right and left lower links 62 are connected via a lift rod 64 and a double-acting rolling hydraulic cylinder 65.

  A driving unit 14 is formed behind the engine 11. A steering handle 15 that performs a steering operation of the front wheels 1a and a meter panel 16 that is one of notification devices that give various notifications to the driver are disposed in front of the driving unit 14. A driver's seat 17 is disposed between the pair of left and right rear wheel fenders 18 at the rear of the driver 14. A ROPS (Roll Over Protection Structure) frame 19 is disposed behind the driver's seat 17 between the pair of left and right rear wheel fenders 18. A brake lamp 83 is provided at the rear of the rear wheel fender 18. Right and left direction indicators 81 are provided on the outside (or inside) of the upper right and left sides of the top of the lops frame 19, and an announcement lamp 82 that is one of the announcement devices is provided below the direction indicator 81. It has been.

  In this embodiment, as an internal elevating operation tool 2 that is manually operated from the driver's seat 17 to operate the elevating hydraulic cylinder 60, an elevating position adjusting operation body 21 and a forced elevating operation body 22 are provided. The lifting position adjusting operation body 21 is formed as a lever arranged on the side of the driver's seat 17, and is therefore referred to as a lifting adjustment lever 21 hereinafter. The forced raising / lowering operation body 22 is formed as a lever disposed on the lower right side of the steering handle 15 and is hereinafter referred to as a forced raising / lowering lever. In order to operate the lifting hydraulic cylinder 60, an external lifting operation tool 30 that is manually operated from the outside of the machine body is provided. In this embodiment, the external lifting / lowering operation tool 30 is disposed in the rear side end region of the rear wheel fender 18 and is formed as a switch having a raised position, a neutral position, and a lowered position. The operation tool 30 is referred to as an external lift switch. A dial-type PTO clutch operating tool 40 that is manually operated to turn the PTO clutch 41 on and off is disposed on the side of the driver seat 17.

Next, with reference to FIG. 4, a description will be given of the configuration of lifting control using the link mechanism 6, rolling control, and PTO control using the PTO clutch 41.
The three-position switching type lift control valve 91 for driving the lift hydraulic cylinder 60 is controlled by an operation control signal from the control device 5. The lift arm 63, the top link 61, and the lower link 62 are moved by the elevating hydraulic cylinder 60 extending and retracting (see FIG. 3), and as a result, the rotary tiller 3 is moved up and down. A three-position switching type rolling control valve 92 for driving the rolling hydraulic cylinder 65 is also controlled by an operation control signal from the control device 5. As the rolling hydraulic cylinder 65 expands and contracts, the rotary tiller 3 is adjusted for rolling around a connection point with the lower link 62 on the opposite side of the rolling hydraulic cylinder 65.

  The PTO clutch 41 is a friction multi-plate hydraulic clutch, and is configured to be operated in a transmission state by being energized in a disconnected state and supplied with hydraulic oil. In the PTO clutch 41, a power transmission state and a power cutoff state are selectively created by a PTO control valve 93 that performs a hydraulic oil supply / discharge operation based on a drive signal from the control device 5.

  The rotary tiller 3 is provided with a rear cover 31 that can swing up and down, and the rear cover 31 is biased downward by a spring 33 to detect the vertical angle of the rear cover 31 with respect to the rotary tiller 3. And the detection value of the tilling depth sensor 32 is input to the control device 5. The operating depth 14 is provided with a tilling depth setting device 34 that is manually operated by a dial operation type, and an operation signal of the set tilling depth of the tilling depth setting device 34 is input to the control device 5.

  When the lift control valve 91 is controlled so that the detection value of the tilling depth sensor 32 becomes the set tilling depth of the tilling depth setting device 34, the lift arm 63, the top link 61, and the lower link 62 are driven to move up and down by the lifting hydraulic cylinder 60. As a result, the rotary tiller 3 moves up and down. The tillage sensor 32 detects the height from the ground G to the rotary tiller 3 and detects the tillage depth H1 of the rotary tiller 3. Accordingly, the lifting arm is lifted by the lifting hydraulic cylinder 60 so that the tillage depth H1 of the rotary tiller 3 becomes the set tillage depth of the tiller setter 34 so that the rotary tiller 3 is positioned at the set height from the ground G. 63, the top link 61 and the lower link 62 move up and down.

  An angle sensor 66 for detecting the vertical angle of the lift arm 63 with respect to the airframe is provided at the base of the lift arm 63, and a detection value of the angle sensor 66 is input to the control device 5. A lift adjustment lever 21 is provided in the operating unit 14 of the machine body, and a detection value of a lift lever sensor 35 that detects an operation position of the lift adjustment lever 21 is input to the control device 5. The elevating adjustment lever 21 can be manipulated artificially. Even when the elevating adjustment lever 21 is released, the elevating adjustment lever 21 is held in its operating position by a friction holding mechanism (not shown).

  Thus, based on the detection value of the lift lever sensor 35, the lift arm 63, the lift arm 63, the lift arm 63, The top link 61 and the lower link 62 work together, and as a result, the rotary tiller 3 moves up and down to the target position.

Next, forced elevation and rolling control will be described.
The operation position of the forced lift lever 22 is input to the control device 5 via the forced lift lever sensor 36. The forced raising / lowering lever 22 is configured to be freely operated in a neutral position, a raised position, and a lowered position, and is biased to the neutral position.

  When the forced lift lever 22 is operated to the raised position (operated to the raised position and then to the neutral position), the lift arm 63, the top link 61, and the lower link 62 are interlocked by the lift hydraulic cylinder 60, resulting in a rotary tiller. 3 rises to a preset upper limit position. When the forced lift lever 22 is operated to the lowered position (operated to the lowered position and then to the neutral position), the lifting arm 63, the top link 61, and the lower link 62 are interlocked by the rolling hydraulic cylinder 65, resulting in a rotary tiller. 3 is lowered to the position before being raised.

  Note that when the rotary tiller 3 is lifted by a predetermined height or more by using the lift adjustment lever 21 or the forced lift lever 22, the PTO clutch 41 is operated in a disconnected state. Further, rolling control, which will be described later, is also released, the rolling hydraulic cylinder 65 is expanded and contracted so as to have the same length as the lift rod 64, and the rotary tiller 3 is held parallel to the left and right directions of the body. At that time, when the rotary tiller 3 is lowered to a position below a predetermined height using the forced elevating lever 22, the PTO clutch 41 is operated in the transmission state. At the same time, rolling control is restored.

  As shown in FIGS. 3 and 4, a stroke sensor 67 for detecting the operating position of the rolling hydraulic cylinder 65 and a weight-type tilt sensor 68 for detecting an angle in the horizontal direction of the aircraft relative to the horizontal plane of the aircraft are provided. The detection value of the sensor 67 and the detection value of the tilt sensor 68 are input to the control device 5. By detecting the operating position of the rolling hydraulic cylinder 65 with the stroke sensor 67, the angle of the horizontal direction of the rotary tiller 3 with respect to the machine body can be detected. By detecting this, it is possible to detect the angle of the horizontal direction of the rotary tiller 3 with respect to the horizontal plane.

  The setting angle of the tilt setting device 37 input to the control device 5 means the angle in the left-right direction of the machine body that should be maintained with respect to the horizontal plane of the rotary tilling device 3, and the setting angle of the tilt setting device 37 is horizontal. The position can be arbitrarily set and changed from the position to the right-down side and the left-down side. As a result, the top link 61 and the lower link 62 are rotated by the rolling hydraulic cylinder 65 so that the horizontal angle of the rotary tiller 3 with respect to the horizontal plane with respect to the horizontal plane is maintained at the set angle of the tilt setter 37. 3 is rolling controlled.

  In this embodiment, the external elevating switch 30 is a seesaw type switch having a neutral position, an ascending position, and a descending position, and is neutrally urged. The position state is input to the control device 5. When the external lift switch 30 is operated to the raised position, the lift hydraulic cylinder 60 causes the lift arm 63, the top link 61, and the lower link 62 to move upward, and the rotary tiller 3 is raised. When the external elevating switch 30 is operated to the lowered position, the lift arm 63, the top link 61, and the lower link 62 begin to move in the descending direction by the elevating hydraulic cylinder 60, and the rotary tiller 3 is lowered. When the external elevating switch 30 is operated from the neutral position to the ascending position or the descending position, the PTO clutch 41 is forcibly operated to the disconnected state. This forced disengagement state of the PTO clutch 41 is maintained regardless of the lift position of the rotary tiller 3. In order to release this disconnected state, it is necessary to operate a PTO clutch operating tool 40 described below.

  Next, the PTO clutch operating tool 40 will be described. As shown in FIG. 4, the PTO clutch operating tool 40 has a cutoff position set at the center, a transmission position set on the right side of the cutoff position, and an automatic position set on the left side of the cutoff position. 40 operation positions are input to the control device 5. Of course, in addition to setting the transmission position on the left side of the blocking position and setting the automatic position on the right side of the blocking position, various forms may be adopted.

  In this embodiment, the PTO clutch operation tool 40 is configured to be freely pushable and rotatable to the right and left, and the PTO clutch operation tool 40 is in a state where the PTO clutch operation tool 40 is operated to the shut-off position. The PTO clutch operating tool 40 can be operated to the transmission position by rotating to the right while pushing. In a state where the PTO clutch operating tool 40 is being operated to the disengagement position, the PTO clutch operating tool 40 can be operated to the automatic position by rotating the PTO clutch operating tool 40 to the left while pushing it. When the PTO clutch operation tool 40 is pushed and operated while the PTO clutch operation tool 40 is operated to the transmission and automatic positions, the PTO clutch operation tool 40 is automatically returned to the disengagement position.

  When the PTO clutch operating tool 40 is operated to the transmission position, the PTO control valve 93 is operated based on the power transmission control signal from the control device 5, and the PTO clutch 41 is operated to the transmission state. When the PTO clutch operating tool 40 is operated to the cutoff position, the PTO control valve 93 is operated based on the power cutoff control signal from the control device 5, and the PTO clutch 41 is operated to the cutoff state.

  When the PTO clutch operating tool 40 is operated to the automatic position, as described above, when the rotary tiller 3 rises to a height equal to or higher than a preset threshold value, the PTO clutch 41 is operated in a disconnected state, and the rotary tiller 3 Increases to a height below a preset threshold value, the PTO clutch 41 is operated in a transmission state. The threshold value for operating the PTO clutch 41 in the disengaged state and the threshold value for operating the PTO clutch 41 in the transmitting state may be the same value or different values (hysteresis).

  Next, using FIG. 5, a functional unit that is constructed in the control device 5 and particularly related to the present invention will be described. Signals from various sensors and switches shown in FIG. 4 are input to the input evaluation unit 58 that functions as an input interface of the control device 5. An elevation control valve 91, a rolling control valve 92, and a PTO control valve 93 are connected to the solenoid drive unit 9 that functions as an output interface of the control device 5.

  The control device 5 includes the basic functional units described with reference to FIG. 1, that is, an operation command generation unit 51, a lifting operation device control unit 52, an ascent PTO automatic control unit 53, a PTO forced stop control unit 54, a PTO All of the control unit 55 is included. In addition, the functional units shown in FIG. 5 are a target value calculation unit 50, a threshold value setting unit 56, and an upper limit setting unit 57. The target value calculation unit 50 receives the target swing angle of the lift arm 63 based on the operation signals from the lift adjustment lever 21, the forced lift lever 22, and the external lift switch 30 received via the input evaluation unit 58, that is, a rotary tiller. The target value corresponding to the target height of 3 is calculated. The upper limit of the set target value is set by the upper limit setting unit 57. The rotary tiller 3 is prohibited from rising to a height exceeding the upper limit value. This upper limit value is manually input by an upper limit setter (not shown), and the input value is stored in the upper limit setting unit 57 as the upper limit value.

  The threshold value setting unit 56 sets a threshold value (corresponding to a predetermined height of the rotary tiller 3) when the PTO clutch 41 is disengaged as the rotary tiller 3 is raised. It is input manually by the upper limit setter that is not done.

Elevating control of the rotary tiller 3 and the PTO clutch using the elevating adjustment lever 21 that is one of the internal elevating operation tools and the external elevating switch 30 that is the external elevating operation tool by the control device 5 configured as described above. An example of 41 on / off control will be described with reference to the chart of FIG.
First, during the tilling work with the rotary tiller 3 lowered, at the time t1, the lift adjustment lever 21 is operated and moved upward to raise the rotary tiller 3. As a result, the rotary tiller 3 is raised, but when its height (target height) reaches the threshold value set by the threshold value setting unit 56 (time point t2), the function of the PTO automatic control unit 53 at the time of raising is reached. Thus, a command to cut off power transmission to the rotary tiller 3 by the PTO mechanism 4 is given to the PTO controller 55. As a result, a cut operation control signal is output through the solenoid drive unit 9, and the PTO clutch 41 is turned off. When the operation displacement of the lift adjustment lever 21 is stopped, the rotary tiller 3 is maintained at a height corresponding to the displacement position.

  Conversely, when the forced elevating lever 2 is operated and moved downward, the rotary tiller 3 is lowered (time point t3), and its height (target height) is set by the threshold setting unit 56. When the value falls below the threshold (time t4), the power transmission is released to the blocked rotary tiller 3 by the action of the PTO automatic control unit 53 at the time of ascent, and a command for permitting the power transmission is given to the PTO control unit 55. . As a result, an input operation control signal is output through the solenoid drive unit 9, and the PTO clutch 41 is input again.

In the example of FIG. 6, in order to check the state of the rotary tiller 3 in the middle of the operation, the forcible elevating lever 22 is switched to the raised position by operating the lifting adjustment lever 21 to the upper limit, and the rotary tiller 3 has the upper limit height. Is rising. At this time, since the rotary tiller 3 exceeds the threshold value, the PTO clutch 41 is in a disengaged state. In this situation, the driver who goes out of the machine operates the external elevating switch 30 from the neutral position to the lowered position in order to lower the rotary tiller 3 slightly (time point t11). Thereby, when the operation command generation unit 51 gives the lowering operation command to the lifting operation device control unit 52, the rotary tiller 3 starts to descend. When the external elevating switch 30 is operated from the neutral position to the lowered position or raised position (time point t11), the PTO forced stop control unit 54 forces the PTO power to be shut off, that is, the PTO clutch 41 is disconnected. The PTO check flag that brings about the maintenance of the state is turned ON. Therefore, even if the height of the rotary tiller 3 falls below the threshold value when the rotary tiller 3 is lowered (time point t12), the PTO check flag is ON, so the PTO clutch 41 is not engaged and kept in the disconnected state. To do. When the external elevating switch 30 is returned from the lowered position to the neutral position, the ascent of the rotary tiller 3 is finished (time t13). Thereafter, the state of the rotary tiller 3 is checked as the rotary tiller 3 is lifted and lowered based on the operation of the external lift switch 30 until time t14. When this state check is completed, the normal tillage work is resumed. For this purpose, it is necessary to turn off the PTO check flag. The turning off of the PTO check flag is realized by the driver returning to the driver's seat 17 and operating the PTO clutch operating tool 40. That is, when any operation (PTO operation event) is performed on the PTO clutch operating tool 40 such as from the automatic position to the shut-off position and from the transmission position to the automatic position, the PTO forced stop control unit 54 turns the PTO check flag from ON to OFF. (Time t15). Therefore, after that, when the height of the rotary tiller 3 becomes equal to or higher than the threshold value, the PTO clutch 41 is turned off, and when the height of the rotary tiller 3 falls below the threshold value, the PTO clutch 41 is turned on and operated. Automatic control is executed.
In the control chart illustrated in FIG. 6, the lifting adjustment lever 21 is used for lifting and lowering the rotary tiller 3 by the internal lifting operation tool, but a forced lifting lever 22 may be used. The forcible elevating lever 22 is a lever that can be switched between an ascending position and a descending position with the neutral position as a home position, and when operated to the ascending position, the rotary tiller 3 rises to a preset position and operates to the descending position. As a result, the rotary tiller 3 is lowered to a position set in advance. Therefore, the PTO clutch 41 is turned off when the forced lifting lever 22 is switched to the raised position, and the PTO clutch 41 is turned off when the forced lifting lever 22 is switched to the lowered position. Of course, in the raising / lowering operation of the rotary tiller 3 by the forced raising / lowering lever 22, as well as the raising / lowering operation by the raising / lowering adjustment lever 21, the PTO clutch 41 is disengaged when the height (target value) exceeds a threshold value. In addition, it is possible to employ control in which the PTO clutch 41 is engaged when the height (target value) falls below a threshold value.

The above-described PTO check control using the PTO check flag that forcibly stops the PTO when the external lift switch 30 is operated has its height (target value) adjusted during the lift operation by the lift adjustment lever 21. Automatic PTO control (also called up-off control) that puts the PTO clutch 41 in the disengaged state when the threshold value is exceeded and turns on the PTO clutch 41 when its height (target value) falls below the threshold value. This is especially useful when running. Therefore, Ru conveniently der When the PTO restraining control only during the execution of the automatic PTO control (up off control) is executed.

[Another embodiment]
(1) In the embodiment described above, the external lifting switch 30 as the external lifting operation tool is attached to the rear wheel fender 18 which is an exterior member of the fuselage 1. A driver or a worker may be able to carry it as a body. In the functional block diagram shown in FIG. 7, a mobile phone 8 having a remote control function is used as an external lifting operation tool. Data communication is performed with the control device 5 using a wireless communication function (such as WiFi, Bluetooth (registered trademark), infrared rays, etc.) of the mobile phone 8 such as a smartphone. For this reason, the control device 5 is provided with a wireless communication unit 59, and the mobile phone 8 has an external elevating operation function unit 80 that gives an ascending operation command and a descending operation command to the rotary tiller 3 through communication with the wireless communication unit 59. It is built by an application program (app).
(2) In the above-described embodiment, the lifting / lowering adjustment lever 21 and the forced lifting / lowering lever 22 are provided as the internal lifting / lowering operation tool 2. However, the operation form adopts an operation form other than the lever type, such as a button or a dial. May be. Moreover, the number of equipment of the internal lifting operation tool 2 and the external lifting operation tool 30 is not limited in the present invention.
(3) In the embodiment described above, a hydraulic cylinder is used as the lifting actuator 60, but other actuators such as an electric cylinder may be used.
(4) The division of each functional unit constructed in the control device 5 in the above-described embodiment is an example, and each functional unit can be freely integrated or divided as long as a similar function is realized.
(5) In the above-described embodiment, the tractor equipped with the rotary tiller 3 is taken up as a work vehicle. However, the present invention is effective even with a work device other than the rotary tiller 3. The present invention is also effective for a work vehicle other than a tractor that is equipped with a work device that is controlled to move up and down.

  The present invention is applied to various work vehicles including a PTO mechanism and a work device capable of moving up and down to which power is transmitted from the PTO mechanism.

1: Airframe 6: Link mechanism 60: Elevating actuator 17: Driver's seat 2: Internal elevating operation tool 21: Elevating adjustment lever (operating body for elevating position adjustment)
22: Forced lift lever (forced lift operation body)
30: External lift switch (external lift operation tool)
4: PTO mechanism 41: PTO clutch,
40: PTO clutch operation tool 50: Target value calculation unit 51: Operation command generation unit 52: Elevating operation device control unit 53: PTO automatic control unit when ascending 54: PTO forced stop control unit 55: PTO control unit 56: Threshold value Setting section

Claims (7)

The aircraft,
A link mechanism for connecting the work device to the machine body so as to be movable up and down;
A lifting actuator for lifting and lowering the link mechanism;
An internal lifting operation tool that is manually operated from the driver's seat;
An external lifting operation tool that is manually operated from outside the aircraft,
A PTO mechanism for transmitting power to the working device;
A PTO clutch provided in the PTO mechanism;
A PTO clutch operating tool that is manually operated to turn the PTO clutch on and off;
Elevating operation for outputting an elevating operation command for elevating the working device in response to the operation of the internal elevating operation tool and for outputting an elevating operation command for elevating the working device in response to the operation of the external elevating operation tool A device control unit;
A PTO controller that outputs an on / off operation command for the PTO clutch in response to an operation of the PTO clutch operating tool;
A PTO forced stop control unit that commands the PTO control unit to output a cutting operation command for the PTO clutch in response to an operation of the external lifting operation tool ;
In response to an increase in the working device by the internal lifting operation tool above a predetermined height, a cutting operation command to the PTO clutch is output, and an operation to enter the PTO clutch in response to a decrease below the predetermined height. An ascending PTO automatic control unit having an ascending PTO control that outputs a command,
The ascending PTO automatic control unit is a work vehicle that stops the ascending PTO control until the PTO clutch operating tool is manually operated in response to an operation of the external lifting operating tool .   2. The work vehicle according to claim 1, wherein the PTO forced stop control unit releases a disconnection operation command for the PTO clutch when the PTO clutch operation tool is manually operated. A target value calculation unit that calculates an operation target value corresponding to the height of the working device from an operation displacement of the internal lifting operation tool is provided, and the ascent-time PTO automatic control unit is based on the operation target value when the ascent time The work vehicle according to claim 1 or 2 , which executes PTO control. The work vehicle according to any one of claims 1 to 3 , wherein the external lifting / lowering operating tool is an operating body provided on an exterior member of the machine body. The work vehicle according to any one of claims 1 to 3 , wherein the external lifting operation tool is a remote control operating body that can be carried around the work device. The work vehicle according to claim 5 , wherein the remote control operating body is constructed by an application program installed in a mobile phone. The internal elevating operation tool includes an elevating position adjusting operation body and a forced elevating operation body, and the working device is positioned at a height position corresponding to an operation displacement of the elevating position adjusting operation body. the work vehicle according to any one of claims 1 to 6 to produce a lowering operation signal for lowering to the original position from the raised operating signal and the upper position is raised to the raised position which is pre-set the working device.

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