JP2008074130A - Power take-off clutch operation structure for working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide power take-off clutch operation structure for a working vehicle capable of properly operating a PTO clutch into transmission/shut-off state in response to a drive for hoising a working device in the case of the PTO clutch operation structure comprising a hoist lever and a position control means. <P>SOLUTION: The PTO clutch operation structure for a working vehicle comprises the hoist lever 12 to be artificially operated over a predetermined range A1 and the position control means. PTO switching positions A4 and A5 are set lower than the highest position A3 of the predetermined range A1. When the hoist lever 12 is positioned lower than the PTO switching positions A4 and A5, a PTO clutch 29 is operated into the transmission state, and when the hoist lever 12 is positioned higher than the PTO switching positions A4 and A5, the PTO clutch 29 is operated into the shut-off state. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a PTO clutch operating structure for a work vehicle including a PTO shaft capable of transmitting power to a work device connected to an airframe, and a PTO clutch capable of transmitting and interrupting power to the PTO shaft.

In an agricultural tractor that is an example of a work vehicle including a PTO shaft and a PTO clutch, a link mechanism (such as a three-point link mechanism or a two-point link mechanism) and a hydraulic cylinder (equivalent to a lift actuator) that can drive the link mechanism up and down are provided. It is provided in the machine body and is configured so that a working device (for example, a rotary tiller) can be connected to the link mechanism.
In this case, as disclosed in Patent Document 1, when the lift switch (27 in FIGS. 3 and 5 of Patent Document 1) is pressed and operated while the rotary tiller is in contact with the ground, the rotary tiller is operated. Is driven up to the position of the upper limit angle of the link mechanism, and then, when the lift switch is pressed again, the rotary tiller is driven down to the position where it contacts the ground.

  In Patent Document 1, when the lift switch is pushed while the rotary tiller is in contact with the ground, the PTO clutch is operated in the disengaged state, and the rotary tiller is driven up to the position of the upper limit angle of the link mechanism. When the elevating switch is pressed again once again, the rotary tiller is driven down to a position where it comes into contact with the ground, and the PTO clutch is operated in the transmission state.

When the rotary tiller is driven to rotate up, the soil attached to the tillage claws of the rotary tiller is scattered, or the tillage claws of the rotating rotary tiller come into contact with the obstacles at the edge. Since damage may occur, when the rotary tiller is driven up by pressing the lift switch as described above, by operating the PTO clutch in the disengaged state and stopping the rotary tiller, It prevents the scattering of soil adhering to the tilling claws of the rotary tiller and the damage caused by the tilling claws of the rotating rotary tiller coming into contact with the obstacles at the edge.
As a result, the rotary tiller is driven up in order to prevent the scattering of soil adhering to the tillage claws of the rotary tiller and the damage caused by the tillage claws of the rotating rotary tiller coming into contact with the obstacles at the edge. In doing so, it is preferable to operate the PTO clutch in the disengaged state as quickly as possible.

JP-A-8-56413

  When the raising / lowering switch of Patent Document 1 is pressed, the work device is driven up and down over the position where it contacts the ground and the upper limit angle of the link mechanism. The working device cannot be stopped at an intermediate position between the positions. For example, when it is not necessary to operate the work device, such as when turning at the shore, it is not necessary to stop the work device at an intermediate position, so that the lift switch is effective.

Many work vehicles such as agricultural tractors are provided with a lift lever and position control means in addition to the lift switch described above. The elevating lever is operated manually over a predetermined range, and the position control means detects the detected value of the position sensor that detects the operating position of the elevating lever in the predetermined range and the vertical angle of the link mechanism with respect to the airframe. Based on the detected value of the angle sensor, the lift actuator that drives the link mechanism to move up and down is operated so that the link mechanism is positioned with respect to the fuselage at the vertical angle corresponding to the operation position of the lift lever within a predetermined range. It is. Accordingly, by operating the lifting lever to an arbitrary operation position, the work device can be stopped at an arbitrary intermediate position between the position where it contacts the ground and the position of the upper limit angle of the link mechanism.
In the PTO clutch operation structure of a work vehicle, when the elevating lever and the position control means are provided, the PTO clutch can be appropriately operated in the transmission and disengagement states according to the elevating drive of the work device. The purpose is that.

[I]
(Constitution)
The first feature of the present invention is that the PTO clutch operating structure of a work vehicle is configured as follows.
A link mechanism that can freely connect the working device, a lift actuator that can drive the link mechanism up and down, an angle sensor that detects a vertical angle of the link mechanism with respect to the machine body, and a lift that is manually operated over a predetermined range. A lever and a position sensor for detecting an operation position within a predetermined range of the lifting lever;
Based on the detection values of the position and angle sensors, position control means is provided for operating the lifting actuator so that the link mechanism is positioned with respect to the airframe at a vertical angle corresponding to the operating position of the lifting lever within a predetermined range.
A PTO shaft capable of transmitting power to a work device connected to a link mechanism, and a PTO clutch capable of transmitting and interrupting power to the PTO shaft.
The PTO switching position is set on the lower side than the upper limit position of the predetermined range. Based on the detection value of the position sensor, when the lifting lever is positioned lower than the PTO switching position, the PTO clutch is operated in the transmission state, and when the lifting lever is positioned higher than the PTO switching position, the PTO clutch is disconnected. PTO operation means for operating in a state is provided.

(Function)
[I-1]
When the lifting lever and the position control means are provided, the working device is stopped at an arbitrary intermediate position between the position where it contacts the ground and the upper limit angle of the link mechanism by operating the lifting lever to an arbitrary operation position. Can do.
In other words, by operating the elevating lever near the lower limit position and the upper limit position of the predetermined range, the working device can be driven up and down over the position where it contacts the ground and the upper limit angle of the link mechanism. Yes, by operating the lifting lever near the lower limit position of the predetermined range, the working height of the working device (for example, the tilling depth of the rotary tilling device) can be changed.

In this case, the lifting lever is used for the current operation from the point of preventing the scattering of the soil adhering to the tilling claw of the rotary tilling device and the damage caused by the tilling claw of the rotating rotary tilling device coming into contact with the obstacle on the edge. It can be considered that the PTO clutch is immediately operated to the disengaged state when operated upward from the position.
However, with this configuration, when the lifting lever is operated near the lower limit position within the predetermined range in the transmission state of the PTO clutch, and the working height of the working device is changed, the PTO clutch is operated in the disconnected state. Therefore, in order to continue the work, the PTO clutch must be operated again in the transmission state, which is troublesome.

According to the first feature of the present invention, in the lifting lever that is artificially operated over a predetermined range, the PTO switching position is set on the lower side of the upper limit position of the predetermined range, and the lifting lever is positioned further than the PTO switching position. When located on the ascending side, the PTO clutch is configured to be operated in a disengaged state.
As a result, when changing the working height of the working device by operating the lifting lever near the lower limit position of the predetermined range, the lifting lever is located on the lower side of the PTO switching position, and the PTO clutch is operated in the disengaged state. It is not necessary to perform the operation of operating the PTO clutch again in the transmission state in order to continue the work.

[I-2]
According to the first feature of the present invention, when the work device does not need to be operated and the work device does not need to be stopped at an intermediate position, for example, when turning at the shore, the elevating lever is set to the upper limit of the predetermined range. When operated to the position, the working device is driven to rise to the position of the upper limit angle of the link mechanism, and the PTO clutch is operated to the disengaged state.
In this case, the lifting lever is set within a predetermined range from the point of preventing the scattering of soil adhering to the tilling claw of the rotary tilling device and the damage caused by the tilling claw of the rotating rotary tilling device coming into contact with the obstacle on the edge. If the PTO clutch is configured to be in the disengaged state when operated to the upper limit position, it can be said that the operation to disengage the PTO clutch is slow.

According to the first feature of the present invention, since the PTO switching position is set to the lower side of the upper limit position of the predetermined range in the lift lever that is artificially operated over the predetermined range, the lift lever is set to the upper limit of the predetermined range. When the lever is moved to the position, the lift lever reaches the upper limit position of the predetermined range after passing the PTO switching position, and the PTO clutch is operated relatively quickly before the lift lever reaches the upper limit position of the predetermined range. Operated in the shut-off state.
As a result, when the elevating lever is operated to the upper limit position within the predetermined range, the scattering of soil adhering to the tilling claws of the rotary tiller and the rotating rotary tiller rotating as compared with the configuration in which the PTO clutch is operated in the disengaged state. This is advantageous in that it prevents breakage caused by the contact between the tillage nail and the obstacle at the edge of the hook.

[I-3]
When a lift lever and position control means are provided, the reaction speed and operating speed of the lift actuator are limited. For example, when the lift lever is quickly operated from one operation position to another operation position, When starting to operate from the position, the lifting actuator is activated with a slight delay, and when the lifting lever reaches another operating position, the lifting actuator reaches the vertical angle corresponding to another operating position of the lifting lever with a slight delay. A state of stopping is generated.

According to the first aspect of the present invention, the PTO clutch is provided with a position sensor that detects an operation position within a predetermined range of the lifting lever, and when the lifting lever is positioned higher than the PTO switching position based on the detection value of the position sensor. Is configured to be operated in a shut-off state.
Thus, for example, when the lifting lever is quickly operated from the vicinity of the lower limit position of the predetermined range to the upper limit position, before the link mechanism (working device) reaches the vertical angle corresponding to the PTO switching position (corresponding to the PTO switching position). The vertical lever is lower than the vertical angle), and the elevating lever reaches the PTO switching position, and the PTO clutch is operated to the disengaged state earlier.
Therefore, in the previous section [I-2], it prevents the scattering of soil adhering to the tilling claws of the rotary tilling device and the damage caused by the tilling claws of the rotating rotary tilling device coming into contact with the obstacles on the edge. This is even more advantageous than the state of the first aspect of the invention described.

[I-4]
When the working device is driven up to the position of the upper limit angle of the link mechanism (the PTO clutch is disengaged), when the working device is driven down to the position where it contacts the ground, the PTO clutch is transmitted before the working device contacts the ground. (For example, in a rotary tiller, the rotary tiller of the rotary tiller is driven downward while the tiller claw of the rotary tiller is rotated, and the tiller of the rotating rotary tiller gradually enters the ground. It is preferable to go with

According to the first feature of the present invention, when the PTO switching position is set on the lower side than the upper limit position of the predetermined range, and the lift lever is positioned on the lower side than the PTO switching position based on the detection value of the position sensor, The clutch is configured to be operated in a transmission state, and the PTO switching position is located at a position higher than a position within a predetermined range corresponding to a position where the work device contacts the ground.
Thus, when operating the lifting lever from the upper limit position of the predetermined range to the vicinity of the lower limit position, the lifting lever reaches the PTO switching position before the working device contacts the ground, and the PTO clutch is brought into the transmission state relatively quickly. It is operated, and the elevating lever reaches the vicinity of the lower limit position of the predetermined range, and reaches a position where the work device contacts the ground.

  Furthermore, as described in the previous section [I-3], there is a limit to the reaction speed and operation speed of the lift actuator, and when the lift lever is operated quickly, the operation of the lift actuator is delayed with respect to the operation of the lift lever. For example, if the lifting lever is operated quickly from the upper limit position to the lower limit position within the predetermined range, before the link mechanism (working device) reaches the vertical angle corresponding to the PTO switching position (corresponding to the PTO switching position). The up / down angle is higher than the up / down angle), and the elevating lever reaches the PTO switching position, and the PTO clutch is operated to the transmission state sooner.

(The invention's effect)
According to the first feature of the present invention, in the PTO clutch operation structure of the work vehicle, when the elevating lever and the position control means are provided, the work device is grounded with the operation of the PTO clutch being transmitted and disconnected. It is possible to appropriately cope with both the state where the position and the upper limit angle of the link mechanism are driven up and down, and the state where the working height of the working device is changed while maintaining the PTO clutch in the transmission state. Thus, the operability and workability of the PTO clutch of the work vehicle could be improved.

  According to the first feature of the present invention, when the lifting lever is operated to the upper limit position of the predetermined range, the PTO clutch is operated to be disengaged relatively quickly, and the lifting lever is operated near the lower limit position of the predetermined range. In this case, the operability and workability of the PTO clutch of the work vehicle can be improved because the PTO clutch is operated in the transmission state relatively quickly.

[II]
(Constitution)
The second feature of the present invention resides in the following configuration in the PTO clutch operation structure of the work vehicle of the first feature of the present invention.
A rolling actuator for rolling the working device with respect to the machine body is provided, and rolling control means for operating the rolling actuator so as to maintain the angle in the left-right direction of the machine device with respect to the horizontal plane of the working device at a set angle is provided. The rolling switching angle is set on the lower side than the upper limit angle of the link mechanism. Based on the detection value of the angle sensor, when the vertical angle of the link mechanism is lower than the rolling switching angle, the rolling control means is operated, and when the vertical angle of the link mechanism is higher than the rolling switching angle, Rolling operation means for stopping the rolling control means is provided.

(Function)
According to the second feature of the present invention, the “action” described in the preceding item [I] is provided in the same manner as the first feature of the present invention, and in addition to this, the following “action” is provided.
[II-1]
A work vehicle such as an agricultural tractor is provided with a rolling actuator that drives the work device to roll relative to the machine body, and the rolling actuator is operated to operate the rolling actuator so that the horizontal angle of the work device with respect to the horizontal plane is maintained at a set angle. Many have control means.

According to the second feature of the present invention, when the working device is driven up and down over the position where the working device contacts the ground and the upper limit angle of the link mechanism, as described in [I] above, the PTO clutch is transmitted and disconnected. In addition to being operated to the state, the rolling control means is operated to the activated and deactivated states.
It is preferable in terms of stability of the airframe when the rolling control means is operated and the working device is driven to roll in a state where the working device is driven to rise greatly (a state where the working device is driven to rise to the upper limit angle position of the link mechanism). However, as in the second feature of the present invention, the rolling control means is stopped in a state in which the work device is largely driven up (in a state of being driven up to the upper limit angle position of the link mechanism). It is good in terms of stability.

[II-2]
According to the second feature of the present invention, the rolling switching angle is set to the lower side than the upper limit angle of the link mechanism, and the rolling control means is activated and stopped based on the vertical angle and the rolling switching angle of the link mechanism. To be operated.
In this case, since the vertical angle of the link mechanism corresponding to the actual height (vertical angle) of the working device with respect to the aircraft is used, the ground state (the state where the aircraft does not sink into the ground in a hard work area, The rolling switching angle can be set at a position above the ground without being affected by the state in which the airframe is sunk like a paddy field or the like.

Thus, after the working device is driven up to the position of the upper limit angle of the link mechanism (when the PTO clutch is disengaged and the rolling control means is stopped), the lifting lever is operated from the upper limit position within the predetermined range to the lower limit position. In addition, before the working device touches the ground, the vertical angle of the link mechanism reaches the rolling switching position, and the rolling control means is activated relatively quickly, and the horizontal angle of the working device with respect to the horizontal plane becomes the set angle. In a maintained state, the work device reaches a position where it touches the ground.
Therefore, it is possible to prevent a malfunction caused by the working device being in contact with the ground in a state where the angle in the horizontal direction of the machine body with respect to the horizontal plane of the working device is maintained at an inappropriate angle.

[II-3]
As described in the previous section [II-2], considering the state where the elevating lever is operated from the upper limit position of the predetermined range to the vicinity of the lower limit position, the rolling switching angle may be set to the upper limit angle of the link mechanism.
However, when operating the lifting lever from the vicinity of the lower limit position of the predetermined range to the upper limit position, as described in the previous section [II-1], the rolling control means is stopped so that the aircraft body is stable. Therefore, it can be said that the operation of the rolling control means to the stop state is slow.

According to the second feature of the present invention, since the rolling switching angle is set to the lower side than the upper limit angle of the link mechanism, when operating the elevating lever from the vicinity of the lower limit position of the predetermined range to the upper limit position, The upper and lower angles reach the upper limit angle of the link mechanism after passing the rolling switching angle, and the rolling control means is stopped relatively quickly before the upper and lower angles of the link mechanism reach the upper limit angle of the link gypsum. Operated.
As a result, when the lifting lever is operated from the vicinity of the lower limit position of the predetermined range to the upper limit position, the rolling control means is stopped, compared to the configuration in which the rolling switching angle is set to the upper limit angle of the link mechanism, thereby stabilizing the aircraft. It is advantageous in that it is good in terms of.

(The invention's effect)
According to the second feature of the present invention, the “effect of the invention” described in the preceding item [I] is provided in the same manner as the first feature of the present invention. In addition, the following “effect of the invention” is provided. ing.
According to the second feature of the present invention, the stability of the airframe is improved by stopping the rolling control means in a state in which the work device is driven to be largely lifted (a state in which the work device is lifted to the upper limit angle position of the link mechanism). I was able to.

  According to the second feature of the present invention, when the lifting lever is operated from the upper limit position of the predetermined range to the vicinity of the lower limit position, the rolling control means is operated relatively quickly, and the lifting lever is moved within the predetermined range. When operating from the vicinity of the lower limit position to the upper limit position, the operability and workability of the PTO clutch of the work vehicle can be improved because the rolling control means is operated in a stopped state relatively quickly.

[III]
(Constitution)
The third feature of the present invention is that the working vehicle PTO clutch operating structure of the first or second feature of the present invention is configured as follows.
Elevation control means for operating the elevating actuator so as to position the work device at a set height from the ground is provided. When the elevation control means is operated to the stop state, the PTO operation means is configured to be operated to the stop state.

(Function)
According to the third feature of the present invention, the “action” described in the preceding item [I] [II] is provided in the same manner as the first or second feature of the present invention. In addition, the following “action” is provided. It has.
Many work vehicles such as agricultural tractors are provided with a lift control means for operating the lift actuator so that the work device is located at a set height from the ground. For example, in the case of a work device that needs to maintain the work height (plowing depth of the rotary tillage device) at a set value regardless of the posture change of the machine body, such as a rotary tillage device, the lifting control means is operated. It is effective to operate the PTO operation means as described in the preceding item [I].
On the other hand, in a working device such as an excavator or a pasture working machine, the PTO clutch is operated in the transmission and disengagement state according to the working state regardless of the vertical angle of the link mechanism (the height of the working device). It may be appropriate to not operate the elevation control means.

  According to the third aspect of the present invention, in the case of a working device that needs to operate the PTO clutch in the transmission and disengagement states according to the work state, the PTO operation means is brought into the stop state when the lift control means is operated in the stop state. Since it is automatically operated, there is no such thing as forgetting to operate the PTO operating means in a stopped state. As a result, when the working device is lifted and lowered by the lifting lever and the position control means, the PTO operating means is not automatically operated in the transmission and disconnection state by the PTO operation means, and the worker is artificially operated according to the working state. Thus, the PTO clutch can be operated to the transmission and disengagement states.

(The invention's effect)
According to the third feature of the present invention, the “effect of the invention” described in the preceding paragraphs [I] and [II] is provided in the same manner as the first or second feature of the present invention. The effect of the invention is provided.
According to the third aspect of the present invention, in the case of a working device that needs to operate the PTO clutch in the transmission and disengagement state according to the work state, the user forgets to operate the PTO operation means in the stop state. In a working device that needs to operate the PTO clutch in the transmission and disengagement state according to the work state, it prevents a problem caused by the PTO clutch being automatically operated in the transmission and disengagement state by the PTO operation means. As a result, the operability and workability of the PTO clutch of the work vehicle could be improved.

[1]
As shown in FIGS. 1 and 2, a top link 1 (corresponding to a link mechanism) and a right and left lower link 2 (corresponding to a link mechanism) are connected to a mission case 3 of the airframe supported by a front wheel 23 and a rear wheel 24. Are supported by a single-acting hydraulic cylinder 5 (corresponding to a lifting actuator) and are equipped with right and left lift arms 6 (corresponding to a link mechanism). The right and left lift arms 6 and the right and left lower links 2 are connected via a lift rod 7 and a double-acting hydraulic cylinder 8 (corresponding to a rolling actuator), and are four wheels as an example of a work vehicle. A drive-type agricultural tractor is constructed. In this case, a rotary tiller 4 (corresponding to a working device) is connected to the top link 1 and the right and left lower links 2.

  As shown in FIG. 3, the three-position switching type control valve 16 for the hydraulic cylinder 5 is operated by the control device 22, and the lift arm 6, the top link 1 and the lower link 2 (rotary tiller 4) are operated by the hydraulic cylinder 5. It is driven up and down. A three-position switching type control valve 17 for the hydraulic cylinder 8 is operated by the control device 22, and the rotary tiller 4 is rotated around the connection point with the lower link 2 opposite to the hydraulic cylinder 8 by the expansion and contraction operation of the hydraulic cylinder 8. It is driven by rolling.

  As shown in FIGS. 1 and 2, a PTO shaft 26 is provided at the rear part of the transmission case 3, and a transmission shaft 27 is connected across the PTO shaft 26 and the rotary tiller 4. The power of the engine 28 mounted on the airframe is transmitted to the front wheels 23 and the rear wheels 24 via a traveling transmission (not shown) built in the mission case 3, and the power of the engine 28 is transmitted to the mission case. 3 is transmitted to the PTO shaft 26 via the PTO clutch 29 housed in 3, and is transmitted to the rotary tiller 4 via the transmission shaft 27. As shown in FIG. 3, the PTO clutch 29 is a frictional multi-plate hydraulic clutch, and is configured to be energized in a disconnected state and operated in a transmission state by supplying hydraulic oil. The PTO clutch 29 is provided with a control valve 30 for performing a hydraulic oil supply / discharge operation.

[2]
Next, the elevation control means and the position control means will be described.
As shown in FIGS. 1, 2, and 3, the rotary tiller 4 is provided with a rear cover 9 that can swing up and down, and the rear cover 9 is urged downward by a spring 18, so that the rear cover with respect to the rotary tiller 4 is covered. The tilling depth sensor 10 for detecting the vertical angle of 9 is provided, and the detected value of the tilling depth sensor 10 is input to the control device 22. A plowing depth setting device 11 that is artificially operated by a dial operation type and a lifting control switch 21 that is artificially operated are provided in the operation unit 19, and a set tilling depth and a lifting control switch of the plowing depth setting device 11 are provided. The operation signal 21 is input to the control device 22, and the elevating control switch 21 is used to operate the elevating control means in the activated and stopped states.

  As a result, as shown in FIGS. 1, 2, and 3, the detected value of the tilling depth sensor 10 becomes the set tilling depth of the tilling depth setting device 11 in a state where the lifting control means 21 is operated by the lifting control switch 21. Thus, the control valve 16 is operated in such a manner that the lift arm 6, the top link 1, and the lower link 2 (the rotary tiller 4) are driven up and down by the hydraulic cylinder 5. The tillage sensor 10 detects the height from the ground G to the rotary tiller 4, and detects the tillage depth H1 of the rotary tiller 4. Therefore, the rotary tiller 4 is set to the set height from the ground G. The lift arm 6, the top link 1, and the lower link 2 (rotary tilling device 4) are arranged by the hydraulic cylinder 5 so that the tilling depth H 1 of the rotary tilling device 4 becomes the set tilling depth set by the tilling depth setting device 11. Is driven up and down (lift control means).

  As shown in FIGS. 1, 2, and 3, an angle sensor 13 that detects the vertical angle of the lift arm 6 with respect to the airframe is provided at the base of the lift arm 6, and the detection value of the angle sensor 13 is input to the control device 22. ing. The operating unit 19 of the machine body is provided with the elevating lever 12, and the detection value of the position sensor 25 that detects the operation position of the elevating lever 12 is input to the control device 22. The elevating lever 12 can be manually operated over a predetermined range A1, and the elevating lever 12 is held in its operating position by a friction holding mechanism (not shown) even if the hand is released from the elevating lever 12.

  Accordingly, as shown in FIGS. 1 and 3, the lift arm 6 is moved to the vertical angle corresponding to the operation position of the elevating lever 12 in the predetermined range A <b> 1 based on the detection values of the position and angle sensors 25 and 13. The lift arm 6, the top link 1, and the lower link 2 (rotary tilling device 4) are moved up and down by the hydraulic cylinder 5 (position control means). In this case, the predetermined range A1 of the lifting lever 12 corresponds to the upper and lower range B1 of the lift arm 6, the lower limit position A2 of the predetermined range A1 corresponds to the lower limit angle B2 of the upper and lower range B1, and the upper limit position A3 of the predetermined range A1. Corresponds to the upper limit angle B3 of the vertical range B1.

  In the above-described lift control means and position control means, when the lift control means is operated to be stopped by the lift control switch 21, the lift control means is stopped and the position control means is activated. When the elevation control switch 21 is operated to the operating position (operating state of the elevation control means), when the elevation lever 12 is operated to the lower limit position A2 of the predetermined range A1, the elevation control means is activated and the position control means is activated. Therefore, when the elevating lever 12 is operated to an operating position other than the lower limit position A2 of the predetermined range A1, the elevating control means is stopped and the position control means is activated.

[3]
Next, the forced raising / lowering means and the rolling control means will be described.
As shown in FIGS. 1 and 2, a forcible elevating lever 32 is provided on the lower right side of the steering handle 31 that performs the steering operation of the front wheel 23, and the operation position of the forcible elevating lever 32 is input to the control device 22. ing. The forcible elevating lever is configured to be operable in a neutral position, a raised position, and a lowered position, and is biased to the neutral position.

  When the forced elevating lever 32 is operated to the raised position (operated to the raised position and then to the neutral position), the lift arm 6, the top link 1 and the lower link 2 (rotary tiller 4) are lifted by the hydraulic cylinder 8. The arm 6 is driven to rise from the vertical angle of the arm 6 to the upper limit angle B3 of the vertical range B1. When the forced elevating lever 32 is operated to the lowered position (operated to the lowered position and operated to the neutral position), the lift arm 6, the top link 1 and the lower link 2 (rotary tiller 4) are moved up and down by the hydraulic cylinder 8. The lifter 6 is driven down to the vertical angle before being lifted from the upper limit angle B3 (forced lifting means).

  Regardless of the operation and stop state of the PTO operation means described in [6], [7], and [8], which will be described later, when the forced elevating lever 32 is operated to the raised position (operating to the raised position and operating to the neutral position), At the same time as the lift arm 6, the top link 1 and the lower link 2 (rotary tilling device 4) start to be lifted by the hydraulic cylinder 8, the PTO clutch 29 is operated in the disconnected state, and the lifting control means and the position control means are stopped. Manipulated to state. A rolling control means, which will be described later, is operated in a stopped state, and the hydraulic cylinder 8 is expanded and contracted so as to have the same length as the lift rod 7, so that the rotary tiller 4 is held parallel to the aircraft in the left-right direction. The

  Regardless of the operation and stop state of the PTO operation means described in [6], [7] and [8] described later, when the forced elevating lever 32 is operated to the lowered position (operating to the lowered position and operating to the neutral position), At the same time that the lift arm 6, the top link 1 and the lower link 2 (rotary tillage device 4) start to be lowered by the hydraulic cylinder 8, the PTO clutch 29 is operated in the transmission state, and the lift control means, position control means, and rolling The control means is operated to the operating state.

  As shown in FIGS. 2 and 3, a stroke sensor 14 for detecting the operating position of the hydraulic cylinder 8 and a weight-type tilt sensor 15 for detecting an angle in the horizontal direction of the aircraft relative to the horizontal plane of the aircraft are provided. The detected value 14 and the detected value of the inclination sensor 15 are input to the control device 22. By detecting the operation position of the hydraulic cylinder 8 with the stroke sensor 14, the angle of the horizontal direction of the rotary tiller 4 with respect to the machine body can be detected. By detecting, the angle of the horizontal direction with respect to the horizontal surface of the rotary tiller 4 can be detected.

As shown in FIGS. 2 and 3, a tilt setting device 20 that is artificially operated by a dial operation type is provided in the operation unit 19, and a setting angle of the tilt setting device 20 is input to the control device 22. The setting angle of the inclination setting device 20 means an angle in the left-right direction of the machine body that should be maintained with respect to the horizontal plane of the rotary tiller 4. Can be set and changed arbitrarily.
As a result, the top link 1 and the lower link 2 (rotary tiller 4) are driven by the hydraulic cylinder 8 so as to maintain the angle of the horizontal direction of the rotary tiller 4 with respect to the horizontal plane at the set angle of the tilt setting device 20. (Rolling control means).

[4]
Next, the PTO switch 33 will be described.
As shown in FIG. 3, the driving unit 19 is provided with a PTO switch 33 that is manually operated by a dial operation type. The PTO switch 33 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, and the operation position of the PTO switch 33 is input to the control device 22. ing.
In this case, the transmission position may be set on the left side of the blocking position, and the automatic position on the right side of the blocking position may be set.

  As shown in FIG. 3, the PTO switch 33 is configured to be freely pushable and to be rotated to the right and left. When the PTO switch 33 is operated to the cutoff position, the PTO switch 33 is pushed and operated. However, the PTO switch 33 can be operated to the transmission position by rotating to the right. In a state where the PTO switch 33 is being operated to the cutoff position, the PTO switch 33 can be operated to the automatic position by rotating the PTO switch 33 to the left while pushing the PTO switch 33. When the PTO switch 33 is pushed and operated while the PTO switch 33 is operated to the transmission and automatic position, the PTO switch 33 is automatically returned to the cutoff position.

[5]
Next, control when the PTO switch 33 is operated to the transmission and shut-off positions will be described with reference to FIG.
When the PTO switch 33 is operated to the transmission position (step S1), the PTO operation means described in [6], [7] and [8], which will be described later, is stopped (step S2), and the PTO clutch 29 is set to the transmission state. It is operated (step S3). When the PTO switch 33 is operated to the disengagement position (step S1), the PTO operation means described in [6], [7] and [8] described later is operated to the stop state (step S4), and the PTO clutch 29 is disengaged. It is operated (step S5).

  When the operating position of the elevating lever 12 is detected (step S6) and the elevating lever 12 is operated to an operating position other than the lower limit position A2 of the predetermined range A1 (step S7), the elevating control means is operated in a stopped state. (Step S8), the position control means is operated to the operating state (Step S9), and the lift arm is moved by the hydraulic cylinder 5 in accordance with the operation position of the elevating lever 12 (detected values of the position and angle sensors 25 and 13) and the position control means. 6. The top link 1 and the lower link 2 (rotary tiller 4) are driven up and down.

  If the elevating lever 12 is operated to the lower limit position A2 of the predetermined range A1 (step S7), if the elevating control switch 21 is operated to the operating position (step S10), the elevating control means is operated to the operating state (step S10). In step S11), the position control means is operated in a stopped state (step S12), and the lift arm 6 is lifted by the hydraulic cylinder 5 according to the detected value of the tilling depth sensor 10, the set tilling depth of the tilling depth setting device 11 and the lifting control means. The top link 1 and the lower link 2 (rotary tiller 4) are driven up and down. In this case, when the elevation control switch 21 is operated to the stop position (step S10), the elevation control means is operated to the stop state (step S8), and the position control means is operated to the operation state (step S9).

  As shown in FIG. 3, in the vertical range B1, the first rolling switching angle B4 is set to the lower side of the upper limit angle B3 of the vertical range B1, and the second rolling switching is set to the lower side of the first rolling switching angle B4. An angle B5 is set. First and second rolling switching angles B4 and B5 are set on the higher side of the central angle of the vertical range B1, and an interval (for example, a dead zone) is set between the first and second rolling switching angles B4 and B5. Exist).

  As described above, the lift arm 6, the top link 1, and the lower link 2 (rotary tiller 4) are operated by the hydraulic cylinder 5 in accordance with the operation position of the elevating lever 12 (detected values of the position and angle sensors 25 and 13) and the position control means. The vertical angle of the lift arm 6 is detected (step S13).

  In this case, when the vertical angle of the lift arm 6 exceeds the first rolling switching angle B4 and changes to the ascending side (see arrow BY1 in FIG. 3) (step S14), the rolling control means is operated to stop (step S15). ), The hydraulic cylinder 8 is expanded and contracted so as to have the same length as the lift rod 7 (step S16), and the rotary tiller 4 is held parallel to the machine body in the left-right direction. When the vertical angle of the lift arm 6 exceeds the second rolling switching angle B5 and changes to the lower side (see arrow BY2 in FIG. 3) (step S17), the rolling control means is operated (step S18).

[6]
Next, the first half of the control when the PTO operation means and the PTO switch 33 are operated to the automatic position will be described with reference to FIG.
When the PTO switch 33 is operated to the automatic position (step S1), when the elevation control switch 21 is operated to the stop position (step S19), the PTO switch 33 is operated to the cutoff position (step S21). As a result, the PTO operating means is operated to the stopped state (step S4), and the PTO clutch 29 is operated to the disengaged state (step S5) (When the elevation control means is operated to the stopped state, the PTO operating means is Equivalent to a state that is operated in the stop state).

  When the PTO switch 33 is operated to the automatic position (step S1), it is detected whether or not the aircraft is in an interrupted state. If the aircraft is in an interrupted state (step S20), the PTO switch 33 is operated to the shut-off position. Then (step S21), the PTO operating means is operated to the stopped state (step S4), and the PTO clutch 29 is operated to the disengaged state (step S5).

  In this case, the suspended state is a state where the vehicle has traveled for a certain period of time at a high speed that does not travel in a normal work state, a state in which the vehicle has traveled for a certain distance at a high speed that does not travel in a normal work state, A state in which a transmission (not shown) is operated at a high speed position for traveling on the road, a state in which the vehicle travels over a certain distance without performing work at a low speed, and a restart operation after the engine 28 is stopped The state where the rotary tiller 4 (corresponding to the working device) is removed from the top link 1, the right and left lower links 2, and the like.

[7]
Next, the second half of the control when the PTO operation means and the PTO switch 33 are operated to the automatic position will be described with reference to FIG.
When the PTO switch 33 is operated to the automatic position (step S1), the lift control switch 21 is operated to the operating position (step S19), and the PTO operating means is in the operating state if the machine body is not suspended (step S20). (Step S31). The operating position of the elevating lever 12 is detected (step S32), the operating position of the elevating lever 12 is differentiated, and the operating speed of the elevating lever 12 is detected (step S33).

  When the elevating lever 12 is operated to an operating position other than the lower limit position A2 of the predetermined range A1 (step S34), the elevating control means is operated to the stop state (step S35), and the position control means is operated to the operating state. (Step S36), the lift arm 6, the top link 1 and the lower link 2 (rotary tilling device 4) by the hydraulic cylinder 5 according to the operation position of the lifting lever 12 (detected values of the position and angle sensors 25, 13) and the position control means. Is driven up and down.

  When the lifting lever 12 is operated to the lower limit position A2 of the predetermined range A1 (step S34), the lifting control means is operated (step S37), and the position control means is stopped (step S38). The lift arm 6, the top link 1 and the lower link 2 (rotary tillage device 4) are driven up and down by the hydraulic cylinder 5 in accordance with the detected value of the tilling depth sensor 10, the set tilling depth of the tilling depth setting device 11 and the lifting control means. The

As shown in FIG. 3, in the predetermined range A1, the first PTO switching position A4 is set to the lower side of the upper limit position A3 of the predetermined range A1, and the second PTO switching position A5 is set to the lower side of the first PTO switching position A4. Is set. First and second PTO switching positions A4 and A5 are set on the ascending side of the center position of the predetermined range A1, and an interval (for example, a dead band-like interval) is set between the first and second PTO switching positions A4 and A5. ) Exists.
In this case, the first PTO switching position A4 and the first rolling switching position B4 correspond to each other (the vertical angle corresponding to the first PTO switching position A4 matches the first rolling switching angle B4). The second rolling switching angle B5 is set to be slightly higher than the second PTO switching position A5 (the vertical angle corresponding to the second PTO switching position A5 is slightly lower than the second rolling switching angle B5. Is set).

  As described above, the lift arm 6, the top link 1, and the lower link 2 (rotary tiller 4) are operated by the hydraulic cylinder 5 in accordance with the operation position of the elevating lever 12 (detected values of the position and angle sensors 25 and 13) and the position control means. If the operating position of the elevating lever 12 changes to the ascending side beyond the first PTO switching position A4 (see arrow AY1 in FIG. 3) (step S39), the PTO clutch 29 is operated to the disconnected state. (Step S40) At the same time as the buzzer (not shown) is activated, a notification message (that the PTO clutch 29 has been operated in the disengaged state in the operating state of the PTO operating means) is displayed on the meter panel 34 shown in FIG. (Step S41).

  The vertical angle of the lift arm 6 is detected (step S46), and the vertical angle of the lift arm 6 is differentiated to detect the operating speed of the lift arm 6 (step S47). When the vertical angle of the lift arm 6 exceeds the first rolling switching angle B4 and changes to the ascending side (see arrow BY1 in FIG. 3) (step S48), the rolling control means is operated to stop (step S49), and the hydraulic pressure The cylinder 8 is expanded and contracted so as to have the same length as the lift rod 7 (step S50), and the rotary tiller 4 is held parallel to the machine body in the left-right direction.

  As described above, the lift arm 6, the top link 1, and the lower link 2 (rotary tiller 4) are operated by the hydraulic cylinder 5 in accordance with the operation position of the elevating lever 12 (detected values of the position and angle sensors 25 and 13) and the position control means. Is moved up and down, the operating position of the elevating lever 12 changes to the lower side beyond the second PTO switching position A5 (see arrow AY2 in FIG. 3) (step S42), and the operating speed of the elevating lever 12 is When the operation speed is higher than the set operation speed V1 (step S43), the PTO clutch 29 is operated in the transmission state (step S44), and the buzzer (not shown) is stopped. Disappears (step S45).

The vertical angle of the lift arm 6 changes to the lower side beyond the second rolling switching angle B5 (see arrow BY2 in FIG. 3) (step S51), and the operating speed of the lift arm 6 is the set operating speed V2 (step S43). If the speed is higher than that (corresponding to the set operation speed V1) (step S52), the rolling control means is operated (step S53).
In this case, the second rolling switching angle B5 is set to be slightly higher than the second PTO switching position A5 (the vertical angle corresponding to the second PTO switching position A5 is higher than the second rolling switching angle B5. As described above, when the operating position of the lifting / lowering lever 12 changes to the lowering side beyond the second PTO switching position A5 (see arrow AY2 in FIG. 3) (step S42), rolling is performed. After the control means is operated to the operating state, the PTO clutch 29 is operated to the transmission state.

[8]
In step S43 of FIG. 5 described in the previous item [7], even if the operating position of the lifting lever 12 changes to the lower side beyond the second PTO switching position A5 (see arrow AY2 in FIG. 3) (step S42) When the operation speed of the lever 12 is lower than the set operation speed V1 (step S43), the PTO clutch 44 is maintained in the disconnected state without being operated in the transmission state.
In step S52 of FIG. 5 described in the preceding item [7], even if the vertical angle of the lift arm 6 changes to the lower side beyond the second rolling switching angle B5 (see arrow BY2 in FIG. 3) (step S51), If the operating speed of the lift arm 6 is lower than the set operating speed V2 (step S52), the rolling control means is maintained in the stopped state without being operated.

  As described above, when the operating speed of the elevating lever 12 is lower than the set operating speed V1 (the operating speed of the lift arm 6 is lower than the set operating speed V2), the elevating lever 12 is operated arbitrarily. It is considered that after the operator operates the position, the operator releases his hand from the lift lever 12 and the lift lever 12 gradually moves downward from the current operation position due to vibration of the airframe during traveling.

  As a result, even if the operating position of the elevating lever 12 changes beyond the second PTO switching position A5 to the lower side, the operating speed of the elevating lever 12 is lower than the set operating speed V1, so that the PTO clutch 29 is in the transmission state. (If the vertical angle of the lift arm 6 changes to the lower side beyond the second rolling switching angle B5, the operating speed of the lift arm 6 is lower than the set operating speed V2, When the rolling control means is not operated to the operating state), the operator holds the elevating lever 12, operates the elevating lever 12 on the ascending side beyond the second PTO switching position A5, and then again exceeds the second PTO switching position A5. If the elevating lever 12 is operated at a lower operation speed than the set operation speed V1, the process returns to steps S44, S45, and S53 in FIG. .

[First Alternative Embodiment of the Invention]
In step S19 of FIG. 4 of the above-mentioned [Best Mode for Carrying Out the Invention], instead of the lift control switch 21 being operated to the stop position, the rotary tiller 4 (corresponding to the working device) is the top link. When the rear cover 9 is removed from the rotary tiller 4 when the rear cover 9 is removed from the first link 1 and the lower link 2, the PTO switch 33 may be operated to the blocking position (step S21).

  In step S19 of FIG. 4 of the above-mentioned [Best Mode for Carrying Out the Invention], the rolling control means has been operated to the stop state instead of the lift control switch 21 being operated to the stop position, or The PTO switch 33 may be configured to be operated to the cutoff position based on the operation of the auto-up unit being stopped or the backup unit being operated to be stopped (step S21).

  In this case, the auto-up means means that when the front wheel 23 is steered by the steering handle 31 and turned, the lift arm 6, the top link 1 and the lower link 2 (rotary tiller 4) are This means that the lift arm 6 is lifted from the vertical angle of the lift arm 6 to the upper limit angle B3 of the vertical range B1. The backup means means that when a travel transmission (not shown) is operated to a reverse position, the lift arm 6, the top link 1 and the lower link 2 (rotary tiller 4) are lifted by the hydraulic cylinder 5. This is a function that is driven upward from the vertical angle of the arm 6 to the upper limit angle B3 of the vertical range B1.

[Second Embodiment of the Invention]
As shown in FIG. 1, a brake lamp 36 is provided at the rear of a rear wheel fender 35 that covers the rear wheel 24, and a lops frame 37 is provided between the right and left rear fenders 35. Right and left direction indicators 38 are provided outside (or inside) the upper right and left sides of the frame 37. In this case, a notification lamp 39 is provided below the right (or left) direction indicator 38 in the lops frame 37, or a notification lamp 39 is provided above the right (or left) direction indicator 38 in the lops frame 37. (Not shown), the rotary tiller 4 may be provided with a notification lamp 39 (not shown), or the meter panel 34 may be provided with a notification lamp (not shown).

Thereby, in step S41 of FIG. 5 of [Best Mode for Carrying Out the Invention] [First Alternative Embodiment of the Invention], the following configuration may be adopted.
(1) A buzzer (not shown) is operated to turn on (or blink) the notification lamp 39 of the lops frame 37.
(2) A buzzer (not shown) is operated to turn on (or blink) the notification lamp on the meter panel 34.
(3) A buzzer (not shown) is operated to turn on (or flash) the notification lamp 39 of the rotary tiller 4.
(4) A buzzer (not shown) is operated to blink the right and left direction indicators 38 (hazard state).

[Third Another Embodiment of the Invention]
In the above-mentioned [Best Mode for Carrying Out the Invention] [First Alternative Embodiment] [Second Alternative Embodiment], the angle sensor 13 is connected to the base of the top link 1 or the base of the lower link 2. In preparation for this, the position control means may be operated based on the vertical angle of the top link 1 relative to the airframe or the vertical angle of the lower link 2 relative to the airframe. The present invention can also be applied to a two-point link mechanism that does not include the top link 1 but includes the right and left lower links 2 and the right and left lift arms 6.

[Fourth Embodiment of the Invention]
In the above-mentioned [Best Mode for Carrying Out the Invention] [First Alternative Embodiment of the Invention] to [Third Alternative Embodiment of the Invention], the first and second PTO switching positions A4 and A5 are set within a predetermined range A1. , The dead zone may be set for the first and second PTO switching positions A4 and A5. The first and second rolling switching angles B4 and B5 may be set to the same angle in the vertical range B1, and the dead zone may be set with respect to the first and second rolling switching angles B4 and B5.

Whole side view of agricultural tractor and rotary tiller Rear perspective view of agricultural tractor and rotary tiller The figure which shows the relationship of the elevating lever, lift arm, PTO clutch and PTO switch The figure which shows the flow of control at the time of operating a PTO switch to a transmission and interruption | blocking position The figure which shows the flow of control at the time of operating a PTO switch to an automatic position

Explanation of symbols

1, 2, 6 Link mechanism 4 Working device 5 Lifting actuator 8 Rolling actuator 12 Lifting lever 13 Angle sensor 25 Position sensor 26 PTO shaft 29 PTO clutch A1 Predetermined range A3 Predetermined range upper limit position A4, A5 PTO switching position B3 Link mechanism Upper limit angle B4, B5 Rolling switching angle G Ground

Claims (3)

A link mechanism that can be connected to the working device so as to be movable up and down, a lift actuator that can drive the link mechanism up and down, an angle sensor that detects a vertical angle of the link mechanism with respect to the machine body, and is manually operated over a predetermined range. And a position sensor for detecting an operation position within a predetermined range of the lifting lever,
Based on detection values of the position and angle sensor, position control for operating the elevating actuator so that the link mechanism is positioned with respect to the airframe at a vertical angle corresponding to the operating position of the elevating lever in the predetermined range. With means,
A PTO shaft capable of transmitting power to the working device connected to the link mechanism, and a PTO clutch capable of transmitting and interrupting power to the PTO shaft;
Set the PTO switching position below the upper limit position of the predetermined range,
Based on the detection value of the position sensor, when the lifting lever is positioned lower than the PTO switching position, the PTO clutch is operated in a transmission state, and when the lifting lever is positioned higher than the PTO switching position, A PTO clutch operating structure for a work vehicle, comprising PTO operating means for operating the PTO clutch in a disengaged state. A rolling actuator for rolling the work device with respect to the airframe; and a rolling control means for operating the rolling actuator so as to maintain a left-right angle of the work device with respect to a horizontal plane at a set angle. ,
Set the rolling switching angle below the upper limit angle of the link mechanism,
Based on the detection value of the angle sensor, when the vertical angle of the link mechanism is lower than the rolling switching angle, the rolling control means is operated, and the vertical angle of the link mechanism is higher than the rolling switching angle. 2. The PTO clutch operation structure for a work vehicle according to claim 1, further comprising a rolling operation unit that stops the rolling control unit. Elevating control means for operating the elevating actuator so that the working device is located at a set height from the ground,
3. The PTO clutch operation structure for a work vehicle according to claim 1, wherein the PTO operation unit is operated in a stopped state when the elevating control unit is operated in a stopped state. 4.

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