JP2015223096A - Tractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively prevent or reduce the occurrence of a region having no leveling operation due to a rear cover of the rotary tiller though being tilled by a rotary tiller, in the execution of lifting/lowering interlocked control.SOLUTION: A controller executes the closure control for transferring a PTO clutch unit in a power cut-off state while holding the rotary tiller in a working position, upon receiving a lifting command of the rotary tiller when the PTO clutch unit is brought into a transmitted state and a rotary tiller is positioned in the working position in a selection state of a lifting/lowering interlocked mode, and executes the lifting control of a lifting/lowering actuator so that the rotary tiller may be positioned in a non-working position after the execution of the closure control.

Description

  The present invention relates to a tractor including a rotary tiller that is connected to a vehicle main unit so as to be movable up and down and is moved up and down by a lift actuator.

  2. Description of the Related Art Conventionally, a tractor including a rotary tiller that is connected to a vehicle main unit so as to be movable up and down and is moved up and down by a lift actuator has been widely used (for example, see Patent Document 1 below).

  The rotary tiller includes a frame structure coupled to the vehicle main unit via a link mechanism, and rotational power operatively transmitted from an engine provided in the vehicle main unit via a PTO clutch device and a PTO shaft. A tilling shaft driven by the tilling shaft, a tilling claw provided on the tilling shaft, a main cover that covers the rotation trajectory of the tilling claw, and a front end that covers the rear of the rotation trajectory of the tilling claw A rear cover rotatably connected to the rear end of the cover.

  The rotary cultivator having such a configuration can level the surface of the cultivated soil with the rear cover while cultivating with the cultivating claws.

  By the way, the tractor provided with the rotary tiller may be provided with an ascending / descending interlocking mode as a drive control mode of the PTO shaft in order to reduce an operation burden on the operator.

  Specifically, the tractor is provided with a PTO on / off operation member for manually operating engagement / disengagement of the PTO clutch device, and a PTO drive control switching operation member capable of selecting a lift interlocking mode.

  The control device for the tractor performs the operation control of the PTO clutch device in accordance with the operation state of the PTO on / off operation member, and in the state in which the lift interlocking mode is selected by the PTO drive control switching operation member, Even if the PTO clutch device is in a transmission state in response to an operation on the PTO on / off operation member, when a predetermined raising command for raising the rotary tillage device from the working position to the non-working position is input, the rotary tilling device is The PTO clutch device is lifted to the non-lifting position and forcibly shifted from the transmission state to the cutoff state.

  The tractor having such a configuration is useful in that it can effectively reduce the operation burden on the operator when changing the direction of the headland during tillage work.

  That is, when plowing work in a field, the tractor is usually driven from one side to the other side in the field while the rotary tiller is driven in a working position, and the other side of the field is driven. The rotary tiller is stopped at the direction change position (headland) and raised to a non-working position to change the direction of the tractor. After the change of direction, the rotary tiller is driven and lowered to the working position. The inside is repeatedly run from the other side to the one side.

  Here, when the ascending / descending interlock mode is provided, it is possible to eliminate the need for a human operation for stopping the driving of the rotary tiller when the direction is changed at the headland.

  However, the conventional tractor having the above-described configuration is configured to simultaneously perform the lifting operation of the rotary tillage device and the operation of interrupting power transmission to the rotary tilling device when the lift interlocking mode is executed. For this reason, there has been a problem that an area that has been cultivated by the cultivating claws but not subjected to the leveling action by the rear cover is generated.

Japanese Patent No. 4587392

  The present invention has been made in view of such a conventional technique, and when the rotary tiller is driven at the work position, the control device stops driving the rotary tiller in response to the ascent command of the rotary tiller. When performing the ascending / descending interlocking control, it is possible to effectively prevent or reduce the occurrence of an area where the rotary tiller does not receive a leveling action even though the rotary tiller is plowed. The purpose is to provide a tractor.

  In order to achieve the above object, the present invention provides a rotary tiller that is connected to a vehicle main body so as to be able to be raised and lowered while inputting rotational power from an engine via a PTO shaft, and an elevator that raises and lowers the rotary tiller. The control mode for driving the PTO shaft is switched between an actuator, a PTO clutch device that engages and disengages power transmission from the engine to the PTO shaft, a PTO on / off operation member that artificially operates the PTO clutch device. A tractor comprising a PTO drive control switching operation member and a control device for controlling the operation of the lift actuator and the PTO clutch device, wherein the control device selects the lift interlock mode by the PTO drive control switch operation member In this state, the PTO clutch device is driven by the PTO on / off operation member. And when the rotary tiller is in the working position and receives a predetermined raising command for raising the rotary tiller to the non-working position, the PTO is kept in the working position while holding the rotary tiller in the working position. Provided is a tractor that performs a shut-off control for shifting the clutch device to a power shut-off state, and that performs a lift control of the lift actuator so that the rotary tiller is positioned at a non-working position after the shut-off control is performed.

For example, the control device performs the ascending control after a predetermined time has elapsed since the blocking control was performed.
Preferably, there is provided a manipulable operation means for setting the predetermined time from the execution of the shut-off control to the execution of the ascent control.

Instead of or in addition to this, the control device executes the ascent control after traveling for a predetermined distance after executing the blocking control.
Preferably, an operation means capable of being manually operated to set the predetermined distance from the execution of the shut-off control to the execution of the ascent control is provided.

  Preferably, with respect to engine speed control, the control device is configured to perform normal control using a set speed set by an engine speed change operating member that is manually operated as a target speed of the engine speed change actuator, and a speed lower than the set speed. It is possible to execute the deceleration control using the low-speed rotation speed as the target rotation speed.

  In this case, the tractor has an artificial control fixed mode in which the normal control is fixedly executed and a normal control / deceleration control switching mode in which the normal control and the deceleration control are switched according to a predetermined condition. The turn-up work implement raising function for raising the rotary tiller to the predetermined non-working position when the operating angle of the turning operation member exceeds a predetermined value. And a turn-up mode selection means.

  The control device performs the normal control as a basic control when the normal control / deceleration control switching mode is selected, and the normal control when the rotary tiller is raised by the turning work implement raising function. The control device is further configured to shift to the deceleration control, and the control device is further configured to perform the predetermined operation of the rotary tiller by a function of raising the work implement during turning when the lift interlocking mode is selected and the rotary tiller is in a driving state. In response to a command to move to a non-working position, a shut-off control is performed to shift the PTO clutch device from a transmission state to a shut-off state while holding the rotary tiller device in the working position, and then the normal Release the control, execute the deceleration control, and then raise the rotary tiller to a predetermined non-working position. It is intended to run.

  The tractor includes a manually operated manual elevating operation member, a one-touch elevating operation member, and an ascending position setting member. The control device is configured such that the rotary tillage device is operated by the manual elevating operation when the manual elevating operation member is operated. The lift actuator is controlled so as to have a height corresponding to the operation position of the operation member, and the rotary tiller is raised to a height set by the lift position setting member when the one-touch lift operation member is lifted. The lift actuator is configured to control the operation.

  In this case, when the normal control / deceleration control switching mode is selected, the control device performs the normal control as a basic control, and the rotary tiller is lifted by a lifting operation with the one-touch lifting operation member. The control device is configured to shift from the normal control to the deceleration control, and the control device is configured so that the one-touch lifting operation member performs a lifting operation when the lift interlocking mode is selected and the rotary tiller is in a driving state. If the rotary tiller is held at the work position, the PTO clutch device is shifted from the transmission state to the cutoff state, and then the normal control is canceled and the deceleration control is performed. After that, the ascent control is performed to raise the rotary tiller to a predetermined non-working position. That.

  According to the tractor according to the present invention, when the rotary interlocking mode is selected, when the rotary tiller is driven at the working position, a predetermined ascending command for raising the rotary tiller to the non-working position is input to the control device. Then, the control device executes a shut-off control that shifts the PTO clutch device to a power shut-off state while holding the rotary tiller device in a working position, and the rotary tiller device is not working after the shut-off control is executed. Since the lift control of the lift actuator is executed so as to be positioned, the leveling action by the rear cover of the rotary tiller despite the fact that it has been plowed by the rotary tiller during execution of the lift interlock control It is possible to effectively prevent or reduce the generation of a region that does not receive.

FIG. 1 is a side view of a tractor according to an embodiment of the present invention. FIG. 2 is a schematic diagram of transmission of the tractor. FIG. 3 is a block diagram of a control device in the tractor. FIG. 4 is a hydraulic circuit diagram of the tractor. FIG. 5 is a partially enlarged view of the vicinity of the link mechanism in the tractor. FIG. 6 is a schematic view of a PTO drive control switching operation member provided in the tractor. FIG. 7 is a side view of the rotary tiller in the tractor. FIG. 8 is a plan view of the rotary tiller.

Hereinafter, preferred embodiments of a tractor according to the present invention will be described with reference to the accompanying drawings.
1 and 2 show a side view and a transmission schematic diagram of the tractor 1 according to the present embodiment, respectively.

  As shown in FIGS. 1 and 2, the tractor 1 includes a vehicle frame 10, a driver seat 15 supported by the vehicle frame 10, an engine 50 supported by the vehicle frame 10, and a pair of left and right front wheels 20F. A pair of left and right rear wheels 20R, a traveling system transmission structure 60 that transmits rotational power from the engine 50 to driving wheels, a PTO shaft 95 that outputs rotational power to the outside, and rotation from the engine 50 It has a PTO transmission structure 80 that transmits power to the PTO shaft 95, a control device 100 (see FIG. 3 below), and a rotary tiller device 300 that is connected to the vehicle main unit so as to be movable up and down.

FIG. 3 shows a block diagram of the control device 100.
As shown in FIG. 3, in the present embodiment, the control device 100 has a plurality of controllers such as a main machine controller 101 and an engine controller 102.

  The plurality of controllers 101 and 102 are respectively electrically connected to the corresponding sensors and actuators, and the plurality of controllers 101 and 102 are electrically connected to each other via a CAN communication bus 105. Yes.

  As the output control of the engine 50, the control device 100 normally operates the engine speed change actuator so that the output speed of the engine 50 becomes a set speed by the engine speed change operation member 110 that is manually operated. It is configured to perform control.

  Specifically, as shown in FIG. 3, the tractor 1 includes an engine speed changing operation member 110 such as an accelerator lever, and an operation side engine speed sensor 110a that detects an operating position of the engine speed changing operation member 110. An electronic governor including a rack actuator 56 that acts as the engine speed changing actuator and moves the fuel adjustment rack 57 in the fuel injection device of the engine 50; and a rack position sensor that detects the rack position of the fuel adjustment rack 57 57a and an operating side engine speed sensor 50a for detecting the output speed of the engine 50.

  In the normal control, the control device 100 operates the rack actuator 56 using the set rotational speed detected by the operation side engine rotational speed sensor 110a as the target rotational speed of the engine output rotational speed.

  Specifically, the control device 100 controls the operation of the rack actuator 56 using the relationship between the engine speed and the rack position (fuel injection amount) stored in advance in a storage unit such as a ROM.

That is, the control device 100 detects the output speed of the engine 50 detected by the set engine speed detected by the engine speed changing operation member 110 detected by the operating side engine speed sensor 110a and the operating side engine speed sensor 50a. A target rack position (target value of the fuel injection amount) is calculated from the rotation speed and the rack position of the fuel adjustment rack 57 detected by the rack position sensor 57a, and the fuel adjustment rack 57 The rack actuator 56 is operated so as to be positioned at the target rack position.
Note that the relationship is obtained by experiments or the like, and can be stored as a map format or a function format.

As shown in FIG. 2, in the present embodiment, the traveling system transmission structure 60 has a hydraulic continuously variable transmission (HST) 61, a forward / reverse switching device 62, and a gear-type multi-stage transmission 63. .
The HST 61, the forward / reverse switching device 62, and the gear type multi-stage transmission 63 are supported or accommodated in a mission case 30 (see FIG. 1).

  As shown in FIG. 2, the HST 61 is configured to continuously change the rotational power from the engine 50 input via the main clutch 51.

  Note that reference numerals 52 and 53 in FIG. 2 denote a first hydraulic pump and a second hydraulic pump that are driven by rotational power from the engine 50 input via the main clutch 51.

  In the present embodiment, the HST 61 is configured to perform a speed change operation via a main speed change actuator 220 that is operation-controlled by the control device 100.

  Specifically, as shown in FIG. 3, the tractor 1 includes a main transmission operation member 120 that is manually operated, an operation-side main transmission sensor 120 a that detects an operation position of the main transmission operation member 120, and the main transmission actuator. 220 and an operating main transmission sensor 61a for detecting the output rotation speed of the HST 61.

  Then, the control device 100 determines that the output rotation speed of the HST 61 detected by the operating side main transmission sensor 61a is a speed corresponding to the operation state of the main transmission operation member 120 detected by the operation side main transmission sensor 120a. Thus, the operation of the main transmission actuator 220 is controlled.

FIG. 4 shows a hydraulic circuit diagram of the tractor according to the present embodiment.
In the present embodiment, as shown in FIG. 4, the main transmission actuator 220 is accommodated in the hydraulic cylinder 220a and the hydraulic cylinder 220a so as to reciprocate, and operates on a transmission operation member such as a control shaft in the HST 61. A hydraulic piston 220b to be connected and an electromagnetic valve 220c for switching supply / discharge of hydraulic oil to / from the hydraulic cylinder 220a are provided, and the operation of the electromagnetic valve 220c is controlled by the control device 100.
Alternatively, the main transmission actuator 220 can be configured to have an electric motor.

As shown in FIG. 4, the main transmission actuator 220 is configured to operate by pressure oil from the first hydraulic pump 52 that also acts as a charge oil source for the HST 61.
As shown in FIG. 4, the first hydraulic pump 52 and the second hydraulic pump 53 use the stored oil in the transmission case 30 as an oil source.

  The forward / reverse switching device 62 is configured to switch and output the rotational direction of the rotational power operatively transmitted from the HST 61.

  The forward / reverse switching device 62 is in a forward state in which the rotational power from the HST 61 is output to the drive wheel as rotational power in the normal rotation direction (forward direction), and the rotational power from the HST 61 is in the reverse direction (reverse direction). The reverse drive state is output to the drive wheel as the rotational power, and the neutral state in which the power transmission from the HST 61 to the drive wheel is cut off.

  The forward / reverse switching device 62 can be in a forward state or a reverse state in accordance with a manual operation to a forward / reverse switching operation member 130 such as an F / R lever that is manually operated.

  Specifically, as shown in FIG. 3, the tractor 1 includes the forward / reverse switching operation member 130, an operation side forward / reverse sensor 130 a that detects the operation position of the forward / reverse switching operation member 130, and a forward / reverse switching actuator 230. And an operation side forward / reverse sensor 62a for detecting an operation state of the forward / reverse switching actuator 230.

  Then, the control device 100 determines the operation state of the forward / reverse switching operation member 130 in which the output state of the forward / reverse switching device 62 detected by the operating side forward / reverse sensor 62a is detected by the operation side forward / reverse sensor 130a. The operation control of the forward / reverse switching actuator 230 is performed so as to meet the above.

In the present embodiment, as shown in FIG. 4, the forward / reverse switching actuator 230 corresponds to the forward hydraulic piston 203F, the reverse hydraulic piston 230R, the forward hydraulic piston 230F, and the reverse hydraulic piston 230R. A forward electromagnetic valve 231F and a reverse electromagnetic valve 231R for switching between supply and discharge of hydraulic oil are provided, and the electromagnetic valves 231F and 231R are controlled by the control device 100.
Alternatively, the forward / reverse switching actuator 230 can be configured to have an electric motor.

  As shown in FIG. 4, the forward / reverse switching actuator 230 is configured to be operated by pressure oil from the first hydraulic pump 52.

  In the present embodiment, a pilot pressure actuated switching valve 232 is interposed between the first hydraulic pump 52 acting as a pressure oil source, the forward hydraulic piston 230F, and the reverse hydraulic piston 230R. The switching valve 232 switches supply and discharge of hydraulic oil to and from the forward hydraulic piston 230F and the reverse hydraulic piston 230R.

  Specifically, as shown in FIG. 4, the switching valve 232 includes a forward position that is located when the forward pilot pressure is applied, a reverse position that is located when the backward pilot pressure is applied, When the pilot pressure and the reverse pilot pressure are not applied, the neutral position positioned by the neutral spring can be selectively taken.

  When the switching valve 232 is positioned at the forward movement position, the pressure oil flowing from the pressure oil source is supplied to the forward movement hydraulic piston 230F, and the hydraulic oil is drained from the backward movement hydraulic piston 230R, and the switching valve 232 is positioned at the reverse movement position. Then, the hydraulic oil is drained from the forward hydraulic piston 230F and the pressure oil flowing from the pressure oil source is supplied to the backward hydraulic piston 230R. When the hydraulic oil is positioned at the neutral position, the forward piston 230F and The hydraulic oil is drained from both of the reverse pistons 230R.

  The pilot pressure to the switching valve 232 is switched by the forward solenoid valve 231F and the reverse solenoid valve 231R that are controlled by the control device 100.

  In other words, the forward solenoid valve 231F selectively selects a forward state in which the forward pilot pressure for bringing the switching valve 232 into the forward state is applied to the switching valve 232 and a drain state in which the forward pilot pressure is released. It is configured to take.

  The forward solenoid valve 231F is held in a drain state by a return spring when no operating current is applied, and an operating current is applied from the control device 100 in accordance with a forward operation to the forward / reverse switching operation member 130. When it is received, the drain state is shifted to the forward state.

  The reverse solenoid valve 231R selectively takes a reverse state in which a reverse pilot pressure for bringing the switching valve 232 into a reverse state is applied to the switch valve 232 and a drain state in which the reverse pilot pressure is released. In a state where no operating current is applied, the drain spring holds the drain state.

  The reverse solenoid valve 231R is held in a drain state by a return spring when no operating current is applied, and an operating current is applied from the control device 100 according to a reverse operation to the forward / reverse switching operation member 130. When it is received, the drain state is shifted to the reverse state.

  Furthermore, in the present embodiment, the forward / reverse switching device 62 is configured by forcibly positioning the pilot pressure actuated switching valve 232 in the neutral position in response to an operation on the main clutch operating member 135 that is manually operated. Is configured to be in a power cut-off state (neutral state).

  Specifically, as shown in FIG. 4, a clutch valve 235 operatively connected to the main clutch operating member 135 between the first hydraulic pump 52 acting as a pressure oil source and the pilot pressure operated switching valve 232. Is inserted.

  The clutch valve 235 is configured to be able to selectively take a pressure oil supply position that allows the pressure oil to flow into the switching valve 232 from a pressure oil source and a pressure oil blocking position that blocks the pressure oil from flowing in. Has been.

  The clutch valve 235 is constantly urged toward the pressure oil supply position by a return spring, and is located at the pressure oil supply position when no manual operation is performed on the main clutch operation member 135. The main clutch operating member 135 is positioned at the pressure oil shut-off position only when it is manually operated.

  The multi-stage transmission 63 shifts the rotational power input via the forward / reverse switching device 62 and transmits it to the traveling system output shaft 65.

  In the present embodiment, the multi-stage transmission device 63 is configured to perform a speed change operation via an auxiliary transmission actuator 240 that is controlled by the control device 100.

  Specifically, as shown in FIG. 3, the tractor 1 includes an auxiliary transmission operation member 140 that is manually operated, an operation-side auxiliary transmission sensor 140 a that detects an operation position of the auxiliary transmission operation member 140, and the auxiliary transmission actuator. 240 and an operation side auxiliary transmission sensor 63a for detecting the speed of the multi-stage transmission 63.

  Then, the control device 100 responds to the operation state of the sub-transmission operation member 140 in which the gear position of the multi-stage transmission 63 detected by the operating-side sub-speed sensor 63a is detected by the operation-side sub-speed sensor 140a. The sub-transmission actuator 240 is controlled so as to achieve a different gear position.

  In the present embodiment, as shown in FIGS. 2 and 3, the traveling system transmission structure 60 further has a pair of rear wheels 20 </ b> R that act as main drive wheels using the rotational power of the traveling system output shaft 65. A differential transmission main drive wheel side differential gear device 66, a sub drive wheel drive device 70 for inputting rotational power of the traveling system output shaft 65, and rotational power from the sub drive wheel drive device 70 as sub drive wheels. A sub-drive wheel side differential gear device 71 that differentially transmits to the pair of front wheels 20F that act, and a pair of left and right brake devices 75L and 75R that can apply braking force to the pair of left and right main drive wheels, respectively. Yes. In FIG. 2, only the left brake device 75L is shown.

  Further, as shown in FIGS. 1, 3 and 4, the tractor 1 includes a turning operation member 115 such as a steering wheel which is manually operated, and an operation side turning sensor which detects an operation position of the turning operation member 115. 115a, a turning actuator 215 such as a power steering device, and an operation side turning sensor 90a for detecting a vehicle turning angle.

  Then, the control device 100 controls the turning actuator 215 so that the vehicle turning angle detected by the operation side turning sensor 90a becomes the operation angle of the turning operation member 115 detected by the operation side turning sensor 115a. Perform operation control.

  In the present embodiment, as shown in FIG. 4, the swing actuator 215 includes a hydraulic cylinder 215a, a hydraulic piston 215b that is reciprocally accommodated in the hydraulic cylinder 215a, and is operatively connected to a steering wheel, An electromagnetic valve 215c for switching supply / exhaust of hydraulic oil to / from the hydraulic cylinder 215a is provided, and the electromagnetic valve 25c is controlled by the control device 100.

  As shown in FIG. 4, the turning actuator 215 is configured to be operated by pressure oil from the first hydraulic pump 52.

Next, the PTO transmission structure 80 will be described.
As shown in FIG. 2, in the present embodiment, the PTO transmission structure 80 includes a PTO clutch device 81 and a PTO transmission device 82.

  The PTO clutch device 81 is configured to selectively transmit or cut off rotational power from the engine 50 input via the main clutch 51.

  The PTO transmission device 82 is configured to change the rotational power from the engine 50 input via the PTO clutch device 81 and output it to the PTO shaft 95.

  In the present embodiment, the PTO clutch device 81 and the PTO transmission device 82 are configured to operate by a PTO clutch actuator 260 and a PTO transmission actuator 270 that are controlled by the control device 100, respectively. .

  That is, as shown in FIG. 3, the tractor 1 includes an artificially operated PTO on / off operation member 160, an operation side PTO on / off sensor 160a for detecting an operation position of the PTO on / off operation member 160, and the PTO. A clutch actuator 260, an operating side PTO on / off sensor 81a for detecting the operating state of the PTO clutch device 81, an artificially operated PTO speed change operating member 170, and an operating side for detecting the operating position of the PTO speed change operating member 170 A PTO transmission sensor 170a, the PTO transmission actuator 270, and an operation side PTO transmission sensor 82a for detecting an operation state of the PTO transmission device 82 are provided.

  Then, the control device 100 operates the PTO on / off operation member 160 in which the operating state of the PTO clutch device 81 detected by the operating side PTO on / off sensor 81a is detected by the operating side PTO on / off sensor 160a. The operation of the PTO clutch actuator 260 is controlled so as to change according to the state, and the operation state of the PTO transmission device 82 detected by the operation side PTO transmission sensor 82a is controlled by the operation side PTO transmission sensor 170a. The operation control of the PTO speed change actuator 270 is performed so as to change according to the detected operation state of the PTO speed change operation member 170.

  In the present embodiment, as shown in FIG. 4, the PTO clutch actuator 260 includes a hydraulic piston 260a and an electromagnetic valve 260b that switches between supply and discharge of hydraulic oil to and from the hydraulic piston 260a. The operation of the electromagnetic valve 260b is controlled by the control device 100.

  As shown in FIG. 4, the hydraulic piston 260 a is configured to be operated by pressure oil from the first hydraulic pump 52.

  As shown in FIGS. 1 and 2, the rotary tiller 300 is installed in the vehicle main unit in a state where rotational power transmitted from the engine 50 to the PTO shaft 95 via the PTO clutch device 81 can be input. It is connected via a link mechanism 380 so as to be movable up and down, and is moved up and down by a lift actuator 320 provided in the tractor 1.

FIG. 5 shows a partially enlarged view in the vicinity of the link mechanism 380.
In the present embodiment, as shown in FIGS. 1 and 5, the link mechanism 380 has a top link 381 and a pair of left and right lower links 382.

  In the present embodiment, the elevating actuator 320 includes an elevating hydraulic cylinder device 330 and a lift valve unit 340 that switches supply and discharge of hydraulic oil to and from the elevating hydraulic cylinder device 330.

  As shown in FIG. 4, the lifting hydraulic cylinder device 330 includes a hydraulic cylinder 331 and a hydraulic piston 332 accommodated in the hydraulic cylinder 331 so as to reciprocate.

  As shown in FIGS. 4 and 5, the hydraulic piston 332 is operatively connected to the lower link 382 via a lift arm 385 and a lift rod 386, and the rotary tiller according to the expansion / contraction operation of the hydraulic piston 332. 300 is moved up and down.

  As shown in FIG. 4, the lift valve unit 340 includes a valve block 350, an ascending electromagnetic proportional valve 360 </ b> U and a descending electromagnetic proportional valve 360 </ b> D accommodated in the valve block 350.

  As shown in FIG. 4, the valve block 350 is discharged with the inlet port 351 that receives the pressure oil from the second hydraulic pump 53 and the excess oil of the pressure oil that is received through the inlet port 351. A surplus oil discharge port 352, a supply / discharge port 353 that supplies / discharges hydraulic oil to / from the lifting hydraulic cylinder device 330, and a drain port 354 that drains the hydraulic oil discharged from the lifting hydraulic cylinder device 330. Is provided.

  The raising electromagnetic proportional valve 360U is controlled by the control device 100 to supply pressure oil received via the inlet port 351 to the supply / discharge port 353 and the pressure oil supply / discharge port 353. The state in which the supply to the device is cut off can be selectively displayed.

  The lowering electromagnetic proportional valve 360D is also controlled in operation by the control device 100, and the pressure oil from the elevating hydraulic cylinder device 330 flowing through the supply / discharge port 353 is discharged from the drain port 354. A state in which the flow of the pressure oil to the drain port 354 is blocked can be selectively exhibited.

  In addition, the code | symbol 362 in FIG. 4 is a diversion valve which flows the surplus oil of the pressure oil received through the said inlet port 351 to the said surplus oil discharge port 352. FIG.

  In the present embodiment, as shown in FIG. 4, a lowering prevention valve mechanism 370 is inserted in a supply / discharge line that fluidly connects the supply / discharge port 353 of the valve block 350 and the hydraulic cylinder device 330. ing.

  The lowering prevention valve mechanism 370 includes a lowering prevention valve 371 inserted in the supply / discharge line and a lowering prevention electromagnetic valve 372.

  The lowering prevention valve 371 has a lowering prevention state that prevents a reverse flow while allowing a flow of pressure oil from the supply / discharge port 353 to the hydraulic cylinder device 330 according to a pilot pressure, and the hydraulic cylinder device. A descending state allowing the flow of hydraulic oil from 330 to the supply / exhaust port 353 is selectively configured.

  The lowering prevention electromagnetic valve 372 is configured to selectively take a state of maintaining or releasing a pilot pressure of the lowering prevention valve 371 in accordance with a manual operation.

  In the present embodiment, as shown in FIG. 4, a slow return valve 375 is further interposed between the lowering prevention valve 371 and the elevating hydraulic cylinder device 330.

  The slow return valve 375 includes a first flow path 376 that allows a flow of hydraulic oil from the supply / discharge port 353 to the hydraulic cylinder device 330 while preventing a reverse flow, and the supply / discharge port 353 and the elevating / lowering port. And a second flow path 377 that fluidly connects the hydraulic cylinder device 330 through a variable throttle, and the throttle amount by the variable throttle can be changed by human operation.

Furthermore, the tractor 1 according to the present embodiment includes a tilt actuator 420 that tilts the rotary tiller 300 in the left-right direction.
As shown in FIG. 4, the tilt actuator 420 includes a tilt hydraulic cylinder device 430 that tilts the rotary tiller 300 in the left-right direction, and a tilt electromagnetic that switches between supply and discharge of hydraulic fluid to the tilt hydraulic cylinder device 430. And a proportional valve 440.

  The tilting hydraulic cylinder device 430 is inserted into one of the pair of left and right lift rods 386, and expands and contracts according to hydraulic oil supply / discharge control so that the rotary tillage device 300 has a horizontal posture with respect to the vehicle main unit. It is configured to be changed.

  As shown in FIG. 4, the tilting hydraulic cylinder device 430 includes a hydraulic cylinder 431 and a hydraulic piston 432 accommodated in the hydraulic cylinder 431 so as to reciprocate.

  The position of the electromagnetic proportional valve for tilting 440 is controlled by the control device 100 in accordance with a manual operation on a tilting operation member 185 (see FIG. 3) that is manually operated.

  That is, as shown in FIG. 3, the tractor 1 detects the tilting state of the tilt operation member 185, the operation side tilt sensor 185 a that detects the operation position of the tilt operation member 185, and the rotary tiller 300. The control device 100 includes the operation side tilt sensor 300b, and the control device 100 detects the tilt operation of the rotary tiller 300 detected by the operation side tilt sensor 300b by the operation side tilt sensor 185b. The position of the tilting proportional solenoid valve 440 is controlled so as to correspond to the operation state of the member 185.

  In the present embodiment, the tilting hydraulic cylinder device 430 is configured to receive the pressure oil from the second hydraulic pump 53 as hydraulic oil.

  Specifically, as shown in FIG. 4, the pressure oil line 510 fluidly connected to the discharge port of the second hydraulic pump 53 is branched into a lifting line 511 and a tilting line 512 via a flow dividing valve 520.

  The lifting line 511 is fluidly connected to the inlet port 351 of the lift valve unit 350, and the tilting line 512 is fluidly connected to the tilting electromagnetic proportional valve 440.

  4 is a main relief valve for setting the hydraulic pressure of the pressure oil line 510, and reference numeral 540 is a safety valve for preventing the hydraulic oil in the lifting hydraulic cylinder device 330 from becoming an abnormally high pressure. .

Next, raising / lowering control of the rotary tiller 300 in the tractor 1 will be described.
First, raising / lowering control of the rotary tiller 300 based on manual operation will be described.
As shown in FIG. 3, the tractor 1 includes a manual lifting operation member 181, a one-touch lifting operation member 182, and a lift position setting member 183.

The manual lifting operation member 181 is an operation member for positioning the rotary tiller 300 at an arbitrary lifting position.
That is, when the manual lifting / lowering operation member 181 is operated, the control device 100 determines that the rotary tiller 300 is positioned at a height corresponding to the operation position of the manual lifting / lowering operation member 181. The valve 360U and the descending electromagnetic proportional valve 360D are operated.

  3 is a manual operation position sensor that detects the operation position of the manual elevating operation member 181, and reference numeral 300 a is a work machine position sensor that detects the elevating position of the rotary tiller 300. .

The one-touch lifting / lowering operation member 182 is a member for positioning the rotary tiller 300 at a predetermined raising position or lowering position by a one-touch operation.
That is, when the one-touch raising / lowering operation member 182 is raised, the control device 100 causes the raising electromagnetic proportional valve so that the rotary tiller 300 is raised to a height set by the raising position setting member 183. Operate 360U.

  3 is a one-touch elevating operation sensor that detects an operation state of the one-touch elevating operation member 182, and reference numeral 183a is a setting ascending position sensor that detects a setting position by the ascending position setting member 183. .

When the one-touch lifting / lowering operation member 182 is lowered, the control device 100 causes the lowering electromagnetic tiller 300 to descend to the lowered position defined by the operation position of the manual lifting / lowering operation member 181. Actuate valve 360D.
In other words, in the present embodiment, the manual elevating operation member 181 also acts as a lowered position setting member.

Next, automatic raising control of the rotary tiller 300 will be described.
The tractor 1 according to the present embodiment automatically turns the rotary tiller 300 when the operation angle of the turning operation member 115 exceeds a predetermined value in a state where the rotary tiller 300 is located at the working position. It has a function to raise the work machine during turning.

Specifically, as shown in FIG. 3, the tractor 1 is provided with a turn-up mode selection means 460 for artificially turning on / off the work implement lift function during turning.
The control device 100 validates the turning work implement raising function when the turning elevation mode selection means 460 is turned on, and invalidates the turning work implement raising function when the turn raising mode selection means 460 is turned off.

By providing the function of raising the working machine at the time of turning, it is possible to facilitate the manual operation at the time of changing the direction at the headland in the field.
That is, when the tractor 1 is reciprocated while the rotary cultivator 300 is located at the work position, the rotary cultivator 300 is raised on the headland in the field to move the direction of the tractor 1. A conversion is necessary. At this time, when the turning work machine ascent function is provided, the operator only performs the turning operation of the vehicle, and does not perform the raising operation of the rotary tilling device 300, and the rotary tilling device 300 does not work. It will automatically rise to the position.

  Further, the tractor 1 is a reverse working machine that automatically raises the rotary tiller 300 when the forward / backward switching operation member 130 is operated backward while the rotary tiller 300 is in the working position. Has a rising function.

  Specifically, as shown in FIG. 3, the tractor 1 is artificially turned on / off with a reverse work implement raising function for raising the rotary tiller 300 according to the reverse operation of the forward / reverse switching operation member 130. A reverse lift switch 470 is provided.

  The control device 100 validates the reverse work implement raising function when the reverse advance switch 470 is turned on, and invalidates the reverse work implement raise function when the reverse advance switch 470 is turned off.

Next, the drive control mode of the PTO shaft 95 in the tractor according to the present embodiment will be described.
As shown in FIG. 3, the tractor 1 is provided with a PTO drive control switching operation member 450 that switches the drive control mode of the PTO shaft 95.
FIG. 6 shows a schematic diagram of the PTO drive control switching operation member 450.

As shown in FIG. 6, the PTO drive control switching operation member 450 is configured to be able to select a lift interlocking mode.
In the present embodiment, as shown in FIG. 6, the PTO drive control switching operation member 450 is configured to be able to select the independent mode and the interlock mode in addition to the ascending / descending interlock mode.

When the interlock mode is selected, the control device 100 causes the PTO on / off operation member 160 to be operated when the main clutch operation member 135 is manually operated (that is, an operation for setting the forward / reverse switching device 61 to the neutral state). Regardless of the operation state, the PTO clutch actuator 260 is operated so as to force the PTO clutch device 81 into a power cut-off state (hereinafter referred to as main clutch interlocking control).
Note that reference numeral 135a in FIG. 3 is a sensor that detects an artificial operation on the main clutch operating member 135.

When the independent mode is selected, the control device 100 performs the operation control of the PTO clutch device 81 independently.
That is, when the independent mode is selected, the control device 100 causes the PTO clutch device 81 to respond to the operation state of the PTO on / off operation member 160 even if the main clutch operation member 135 is manually operated. Then, the PTO clutch actuator 260 is operated.

  When selecting the lift interlocking mode, the control device 100, in addition to the main clutch interlock control, when the PTO clutch device 81 is in a transmission state and the rotary tiller device 300 is positioned at the working position, When receiving a predetermined ascent command to raise the device 300 to the non-working position, the PTO clutch is configured to force the PTO clutch device 81 to be in a power cut-off state regardless of the operation state of the PTO on / off operation member 160. Actuator 260 is actuated (hereinafter referred to as lift interlock control).

  Here, in the present embodiment, when the control device 100 performs the ascending / descending interlock control, the PTO clutch device 81 is put into a power shut-off state while the rotary tiller device 300 is held in a working position. It is configured to execute a shut-off control to be transferred, and to perform a lift control of the lift actuator 320 that lifts the rotary tiller 300 from a working position to a non-working position after the shut-off control is performed.

  According to such a configuration, it is effective that an area that is not subjected to a leveling action by the rear cover 311 of the rotary tiller 300 even though the rotary tiller 300 is plowed is effective when the lift-up interlock control is performed. It can be prevented or reduced.

This effect will be described with reference to FIGS.
7 and 8 are a side view and a plan view of the rotary tiller 300, respectively.

  As shown in FIGS. 1, 7, and 8, the rotary tiller 300 includes a frame structure 301 connected to the link mechanism 380 and a tiller shaft 305 that is rotationally driven by rotational power from the PTO shaft 95. A tilling claw 306 provided on the tillage shaft 305, a main cover 310 that covers the top of the rotation trajectory of the tilling claw 306, and a swing on the main cover 310 so as to cover the rear of the rotation trajectory of the tilling claw 306. And a rear cover 311 that is movably connected.

  The frame structure 301 includes a gear box 301a for inputting rotational power from the PTO shaft 95 through a transmission shaft, and a pair of main beams 301b connected to the left and right of the gear box 301a along the vehicle width direction. An upper link frame 301c supported by the gear box 301a and rotatably connected to a rear end portion of the top link 381, and a rear end portion of the pair of lower links 382 supported by the main beam 301b. A pair of lower link frames 301d connected to each other, a chain case 301e connected to one outer end of the pair of main beams 301b in the body width direction, and the other body of the pair of main beams 301b. A bearing plate 301f coupled to the outer end portion in the width direction so as to face the chain case 301e; There.

  The tilling shaft 305 is supported by the chain case 301e and the bearing plate 301f so as to be rotatable about its axis in a state along the width direction of the machine body, and the gear box 301a, the one main beam 301b, and the chain case 301e. It is rotationally driven around the axis by the rotational power transmitted through the internal transmission mechanism.

  The main cover 310 can be rotated around the tilling shaft 305. In the present embodiment, the position of the main cover 310 is adjusted around the tilling shaft 305 by an electric motor 303 (see FIG. 7).

As shown in FIG. 7, the rear cover 311 has a front end portion connected to a rear end portion of the main cover 310 so as to be rotatable about a pivot shaft 312 extending in the body width direction.
The rear cover 311 has a rear end pressed against the ground by a pressure reducing spring mechanism 315 so that the soil surface cultivated by the cultivating claws 306 can be leveled.

  By the way, in the conventional tractor, the ascending / descending-linked control is performed by a rotary tiller that moves the rotary tiller from a working position to a non-working position, and a rotary tiller that moves the rotary tiller from a driving state to a stopped state. The rotation stop operation is performed at the same time.

  Therefore, when the up-and-down interlock control is executed in the conventional tractor, there is a region that is cultivated by the tilling claw but is not subjected to the leveling action by the rear cover (see Ga in FIG. 7, hereinafter referred to as an unleveled region). Will do.

On the other hand, in the present embodiment, as described above, when the control device 100 executes the lift interlocking control, the PTO clutch device 81 holds the rotary tiller 300 in the working position. Is configured to execute the lifting control of the lifting actuator 320 that moves the rotary tiller 300 from the working position to the non-working position after performing the blocking control. .
According to such a configuration, the generation of the unbalanced region Ga can be effectively prevented or reduced.

  The start of the ascent control can be, for example, a trigger signal indicating that a predetermined time has elapsed since the execution of the shut-off control, or that the vehicle has traveled a predetermined distance after the shut-off control is executed. It can also be a trigger signal.

  Preferably, the manipulating operation means for setting the predetermined time from execution of the shut-off control to execution of the ascent control and / or execution of the ascent control after executing the shut-off control It is possible to provide an operation means that can be manually operated to set the predetermined distance up to.

  In addition, since the said raising / lowering interlocking control interrupts | blocks the power transmission to the said rotary tillage apparatus 300 in response to the raising operation from the working position of the said rotary tillage apparatus 300 to a non-working position, the said raising / lowering interlocking control is performed. The predetermined ascending command as a condition for execution is intended to stop or interrupt the work by the rotary tiller 300.

  Specifically, the predetermined ascending command includes an ascending operation of the one-touch raising / lowering operation member 182 and a turning operation of the turning operation member 115 accompanied by the raising of the rotary tiller 300 by the raising function during turning.

Here, output control of the engine 50 in the tractor 1 according to the present embodiment will be described.
In the tractor 1, the control device 100 is configured to execute deceleration control in addition to the normal control, regarding the output control of the engine 50.

  Specifically, as described above, in the normal control, the target rotation speed of the engine rotation speed change actuator 56 is set so that the output rotation speed of the engine 50 becomes the rotation speed set by the engine rotation speed change operation member 110. The engine speed changing operation member 110 is configured to use a set speed.

On the other hand, in the deceleration control, as the target rotational speed of the engine rotational speed changing actuator 56, a low speed rotational speed lower than the set rotational speed is used instead of the set rotational speed by the engine rotational speed changing operation member 110. It is configured as follows.
The low-speed rotation speed may be obtained by multiplying the set rotation speed by a predetermined deceleration coefficient (for example, 0.85).

  The tractor 1 according to the present embodiment includes a normal control fixed mode in which the normal control is fixedly executed, and a normal control / deceleration control switch in which the normal control and the deceleration control are switched according to a predetermined condition. The mode can be selected manually.

  Specifically, as shown in FIG. 3, the tractor 1 is provided with a traveling mode selection means 500 that can manually select the normal control fixed mode and the normal control / deceleration control switching mode.

  The deceleration control includes a first deceleration control using a first low-speed rotation speed (for example, the set rotation speed × 0.85) lower than the set rotation speed as the low-speed rotation speed, and the low-speed rotation speed as the low-speed rotation speed. Second deceleration control using a second low-speed rotation speed lower than the first low-speed rotation speed (for example, the set rotation speed × 0.7).

  In this case, the travel mode selection means 500 is configured to select the normal control fixed mode, the normal control / first deceleration control switching mode, and the normal control / second deceleration control switching mode. .

  In the tractor 1 according to the present embodiment, the control device 100 is lifted by the one-touch lifting operation member 182 when the normal control / deceleration control switching mode is selected by the traveling mode selection means 500. When the rotary tiller 300 is lifted by operation, the rotary tiller 300 is lifted by the turning work implement raising function, and the rotary tiller 300 is raised by the reverse work implement raising function. In this case, the normal control is shifted to the deceleration control.

According to such a configuration, it is possible to make the vehicle run at a low speed without performing an artificial deceleration operation.
When the rotary tiller 300 is lowered to the work position by the lowering operation with the one-touch lifting operation member 182, the control device 100 shifts from the deceleration control to the normal control.

Here, in the present embodiment, in the state in which the ascending / descending interlocking mode is selected, by the ascent command of the rotary tiller 300 by the turning work machine ascent function or the ascending operation by the one-touch ascending / descending operation member 182 When receiving the raising command of the rotary tiller 300, the control device 100 makes the PTO clutch device 81 shift from the transmission state to the shut-off state while keeping the rotary tiller 300 in the working position. Next, the engine output control for canceling the normal control and executing the deceleration control is changed, and then the ascent control for raising the rotary tiller 300 to a predetermined non-working position is executed. .
According to such a configuration, the leveling action by the rear cover 311 can be obtained more effectively.

  As described above, in the present embodiment, when a predetermined ascending command is received when the ascending / descending interlock mode is selected, the control device 100 performs sequence control that sequentially executes the blocking control and the ascending control. Preferably, the sequence control can be implemented or canceled according to a human operation.

  That is, sequence control selection means that can be manually operated is provided, and when the sequence control selection means is turned on, the control device 100 performs the sequence control, while when the sequence control selection means is turned off, the control device 100 Can be configured to simultaneously perform the blocking control and the raising control.

1 Tractor 50 Engine 56 Rack actuator (engine speed change actuator)
81 PTO clutch device 95 PTO shaft 100 control device 110 engine speed changing operation member 115 turning operation member 160 PTO on / off operation member 181 manual lifting operation member 182 one-touch lifting operation member 183 lift position setting member 300 rotary tillage device 320 lifting actuator 450 PTO drive control switching operation member 460 Turning ascent mode selection means 500 Traveling mode selection means

Claims (7)

A rotary tiller connected to the vehicle main body in a state where the rotational power from the engine is input via the PTO shaft, a lift actuator for lifting and lowering the rotary tiller, and power from the engine to the PTO shaft A PTO clutch device for engaging / disengaging transmission, a PTO on / off operation member for manually operating engagement / disengagement of the PTO clutch device, a PTO drive control switching operation member for switching a control mode related to driving of the PTO shaft, the lifting actuator, A tractor comprising a control device for controlling the operation of the PTO clutch device,
The control device is configured such that the PTO clutch device is in a transmission state by the PTO on / off operation member and the rotary tillage device is in a working position in a state where the ascending / descending interlock mode is selected by the PTO drive control switching operation member. When a predetermined raising command for raising the rotary tillage device to the non-working position is received when the rotary tiller device is being operated, shut-off control is performed to shift the PTO clutch device to the power shut-off state while holding the rotary tiller device at the working position. The tractor is executed, and the lift control of the lift actuator is executed so that the rotary tiller is positioned at a non-working position after the cutoff control is executed.   2. The tractor according to claim 1, wherein the control device executes the ascent control after a predetermined time has elapsed since the execution of the cutoff control.   The tractor according to claim 2, further comprising an operation unit that can be manually operated to set the predetermined time from when the blocking control is performed to when the ascent control is performed.   2. The tractor according to claim 1, wherein the control device executes the ascending control after traveling for a predetermined distance after executing the blocking control.   The tractor according to claim 4, further comprising an operation unit that can be manually operated to set the predetermined distance from the execution of the blocking control to the execution of the ascent control. The control device relates to engine speed control, normal control using the engine speed change operation member set manually by the engine speed change operation member as a target speed of the engine speed change actuator, and low speed rotation lower than the set speed And a deceleration control using a number as the target rotation speed,
For the tractor, the normal control fixed mode in which the normal control is fixedly executed and the normal control / deceleration control switching mode in which the normal control and the deceleration control are switched according to a predetermined condition are artificially selected. A traveling mode selection means for turning on and off artificially turning on and off a turning work implement raising function for raising the rotary tiller to the predetermined non-working position when the operation angle of the turning operation member exceeds a predetermined value. And a selection means,
The control device performs the normal control as a basic control when the normal control / deceleration control switching mode is selected, and the normal control when the rotary tiller is raised by the turning work implement raising function. Configured to shift to the deceleration control from
The control device, when the ascending / descending interlock mode is selected and the rotary tiller device is in a driving state, when the rotary tiller device receives an ascent command to the predetermined non-working position by the turning work implement raising function , Executing the shut-off control for shifting the PTO clutch device from the transmission state to the shut-off state while holding the rotary tiller device in the working position, then canceling the normal control and executing the deceleration control, The tractor according to any one of claims 1 to 5, wherein ascending control is performed to raise the rotary tiller to a predetermined non-working position. It includes a manually operated manual elevating operation member, a one-touch elevating operation member and an ascending position setting member,
The control device controls the operation of the lifting actuator so that the rotary tillage device has a height corresponding to the operation position of the manual lifting operation member when the manual lifting operation member is operated, and the one-touch lifting operation member is lifted Sometimes the rotary tiller is configured to control the lifting actuator so that it rises to the height set by the lift position setting member,
The control device performs the normal control as a basic control when the normal control / deceleration control switching mode is selected, and when the rotary tiller is lifted by a lifting operation with the one-touch lifting operation member. Configured to shift from the normal control to the deceleration control,
When the one-touch lifting operation member is lifted when the lifting / lowering interlocking mode is selected and the rotary tiller is in a driving state, the control device holds the rotary tiller while holding the rotary tiller in a working position. The shut-off control is executed to shift the clutch device from the transmission state to the shut-off state, then the normal control is canceled and the deceleration control is executed, and then the rotary tillage device is moved up to a predetermined non-working position. The tractor according to claim 6, wherein the ascending control is executed.

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