JP2010203301A - Working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a working vehicle having a structure changing the change gear ratio of a continuously variable transmission by an gear change actuator by the operation of a gear change pedal and securing travel stability even if an operation abnormality occurs at the gear change actuator. <P>SOLUTION: The working vehicle includes the continuously variable transmission 21, the gear change actuator 60 changing the change gear ratio of the continuously variable transmission 21 based on an operation quantity of the gear change pedal 16, a brake mechanism 23, a clutch mechanism 22, a mechanical interlocking mechanism changing over the connection and disconnection of the clutch mechanism 22 simultaneously by the operation of the brake mechanism 23 by the operation of a brake pedal 17, a brake apply member 75 bringing the brake mechanism 23 into an operation state, a clutch disconnection member 76 bringing the clutch mechanism 22 into a disconnection state, and a control device 80 bringing the brake mechanism 23 into an operation state by the brake apply member 75 and simultaneously bringing the clutch mechanism 22 into the disconnection state by the clutch disconnection member 76 when the gear change pedal 16 is not operated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a work vehicle that performs shift control of a continuously variable transmission using a shift actuator.

  2. Description of the Related Art Conventionally, a work vehicle that performs shift control of a continuously variable transmission using a shift actuator is known (for example, Patent Document 1). In a work vehicle (rice transplanter) in Patent Document 1, an operation amount of a speed change pedal is detected by a pedal position sensor (detection means), and an arm of a continuously variable transmission (stepless transmission) is positioned at a position corresponding to the operation amount. The speed change control of the continuously variable transmission is performed by controlling the drive of the speed change actuator so that is positioned.

  A work vehicle equipped with a mechanism for operating a clutch and a brake with the same pedal (brake pedal) is known. In a work vehicle equipped with such an operation mechanism, the brake is activated to brake the work vehicle after the clutch is disengaged. However, a work vehicle equipped with the operation mechanism may be in a state in which the clutch is disengaged even when the brake is not activated when the brake pedal is gradually depressed when traveling on an inclined surface or the like. The work vehicle may start to move against the intention of the operator who wants to brake the work vehicle. For this reason, a work vehicle (rice transplanter) has been developed in which the brake device is actuated first to brake the work vehicle, and then the clutch is actuated and the clutch is disengaged by depressing the brake pedal. (For example, Patent Document 2)

Japanese Patent No. 4095356 JP 2003-220933 A

However, in a work vehicle in which a continuously variable transmission is controlled by a speed change actuator as in Patent Document 1 to change the traveling speed, if the drive control of the speed change actuator cannot be performed due to an abnormal operation or the like, the clutch cannot be controlled. . For this reason, there is a problem in that the work vehicle moves even when the brake pedal is operated because the clutch is not disengaged even when the brake pedal is depressed.
On the other hand, in a work vehicle in which the brake is actuated first to brake the work vehicle and the clutch is actuated and the clutch is disengaged as in Patent Document 2, the continuously variable speed change is caused by an abnormal operation of the shift actuator. Even if the device cannot be controlled, if the brake pedal is depressed, the brake is activated first, and the work vehicle is braked. However, this braking is effective when the work vehicle is traveling at a low speed. However, when the vehicle is traveling at a high speed or when it stops suddenly in an emergency, braking with only the brake is sufficient. There was a problem that the braking effect could not be obtained.

  The present invention has been made to solve such a problem, and has a configuration in which the speed ratio of the continuously variable transmission is changed by the speed change actuator based on the operation amount of the speed change pedal, and an operation abnormality occurs in the speed change actuator. Even if it is a case, it aims at providing the work vehicle which can ensure driving | running | working stability.

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

That is, the work vehicle according to the first invention is
A continuously variable transmission that shifts the output of the engine and transmits it to the traveling device;
A work vehicle including a speed change actuator that changes a speed ratio of the continuously variable transmission based on an operation amount of a speed change pedal;
A brake mechanism for applying a braking force to the traveling device;
A clutch mechanism for transmitting or interrupting output from the continuously variable transmission to the traveling device;
A mechanical interlocking mechanism that simultaneously switches the operating state of the brake mechanism and the on / off state of the clutch mechanism by operating a brake pedal;
A braked member that switches the brake mechanism to an activated state;
A clutch disengagement member that switches the clutch mechanism to an disengaged state;
A control device that operates the brake-engaging member so that the brake mechanism is in an activated state and simultaneously operates the clutch disengaging member so that the clutch mechanism is in a disengaged state when the shift pedal is not operated. Is.

The work vehicle according to the second invention is:
An operation abnormality detection means for detecting an operation abnormality of the speed change actuator and a notification means for notifying an operation abnormality of the speed change actuator are provided, and the notification means when the operation abnormality detection means detects an operation abnormality of the speed change actuator. To inform the pilot.

A work vehicle according to a third invention is:
An operation abnormality detection means for detecting an operation abnormality of the speed change actuator and an engine speed control device for controlling the engine speed of the engine are provided, and when the operation abnormality detection means detects an operation error of the speed change actuator, The engine speed is limited within a predetermined value range by the engine speed controller.

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

  In the first invention, when an operation abnormality of the speed change actuator occurs due to a failure or the like during traveling, the brake mechanism is operated by operating the brake pedal and at the same time the clutch mechanism is turned off to reduce the traveling speed. Furthermore, traveling can be stopped. Moreover, even when the operation of the brake pedal is delayed, the brake mechanism and the clutch disengaging member are automatically operated by the control device by simply deactivating the speed change pedal, and at the same time the clutch mechanism is automatically operated. It is possible to reduce the traveling speed, and further stop the traveling. Therefore, even when an operation abnormality of the speed change actuator occurs, the traveling speed can be reduced and traveling can be stopped promptly and reliably, and traveling stability can be ensured.

  In the second aspect of the present invention, when an abnormal operation of the speed change actuator occurs due to a failure or the like during traveling, the operator can recognize the abnormal operation. Therefore, it is possible to immediately cope with an abnormal operation of the speed change actuator, and to ensure running stability.

  In the third aspect of the invention, even if an operation abnormality of the speed change actuator 60 occurs due to a failure or the like during travel, if the operation of the speed change pedal is continued and travel is not stopped, the engine speed Along with the restriction, the traveling speed can be restricted within a predetermined range. Therefore, traveling can be continued while preventing a rapid increase in traveling speed, and traveling stability can be ensured.

The side view of the rice transplanter which concerns on 1st Embodiment. The top view of the rice transplanter which concerns on 1st Embodiment. Schematic of a traveling speed change mission. Schematic which shows the relationship between a driving operation part and a driving | running | working transmission mission. FIG. 5 is an enlarged sectional view taken along line VV in FIG. 4. FIG. 6 is an enlarged sectional view taken along line VI-VI in FIG. 4. The block diagram which shows the control structure of a control apparatus.

  Hereinafter, an embodiment of the present invention will be described using a work vehicle according to the present invention as a rice transplanter. The work vehicle according to the present invention is not limited to a rice transplanter, and may be other agricultural work vehicles, construction work vehicles, or the like.

  First, the overall configuration of the rice transplanter 1 will be described with the arrow A direction in FIG.

  As shown in FIGS. 1 and 2, the rice transplanter 1 includes a multi-row planting seedling planting device 2 and a traveling machine body 3. The seedling planting device 2 is mounted on the rear part of the traveling machine body 3 so as to be rotatable in the vertical direction, and is configured so that the seedlings on the seedling mounting platform 2a can be planted on the field by a plurality of seedling planting claws 2b at an appropriate vertical position. Is done.

  In the traveling machine body 3, the vehicle body frame 4 is supported by a pair of left and right front wheels 6 and a pair of left and right rear wheels 7. The vehicle body frame 4 is equipped with an engine 5 and a traveling speed change mission 20. Then, the output of the engine 5 is appropriately shifted by the traveling shift transmission 20 and then transmitted to the wheels 6 and 7. Thereby, the traveling machine body 3 is allowed to travel.

  The vehicle body frame 4 is provided with a driving operation unit 10. The driving operation unit 10 includes a seat 12, a steering handle 13, a transmission lever 14, a display panel 15, a transmission pedal 16, a brake pedal 17, and the like. The shift pedal 16 and the brake pedal 17 are forward pedals that are arranged on the right and left sides of the floor of the driving operation unit 10 on the right side of the steering handle 13 and pivotally attached to the vehicle body frame 4.

  As shown in FIG. 2, the display panel 15 is disposed in the vicinity of the steering handle 13. The display panel 15 is provided with display means for displaying the airframe status, and in the event of problems such as abnormal operation of the speed change actuator 60 described later, cutting of seedlings and fertilizers, and clogging of fertilizers, this is indicated to the operator. An informing means for informing is provided.

  For example, the notifying means is configured so that a display lamp (not shown) is provided in the display panel body, and is turned on or blinks when the above-described malfunction occurs. However, the notification means can be configured such that a buzzer or the like is provided in the display panel body so that a notification sound is generated when the above-described problem occurs. Further, the notification means is not limited to the display panel and may be provided in another member.

  Next, a configuration for performing a shift will be described.

  As shown in FIG. 3, the traveling transmission mission 20 is provided with a hydraulic continuously variable transmission 21. The continuously variable transmission 21 includes a variable hydraulic pump 24 that is driven by the output of the engine 5 and a hydraulic motor 25 that is driven by the hydraulic pressure from the hydraulic pump 24, and a swash plate 24 a in the hydraulic pump 24. By changing the inclination angle, the speed ratio is changed to change the traveling speed of the traveling machine body 3.

  In the present embodiment, a hydraulic / mechanical continuously variable transmission is configured by combining the hydraulic continuously variable transmission 21 with a mechanical transmission 30 comprising a planetary gear mechanism.

  Further, as shown in FIGS. 4 and 6, a speed change operation shaft 63 extends in the lateral direction at the front portion of the vehicle body frame 4 and is rotatably supported by a bearing. A sector gear 62 is fixed to the speed change operation shaft 63, and the sector gear 62 and the speed change operation shaft 63 can be rotated together. An arm 65 is fixed to the speed change operation shaft 63 at the base end portion thereof, and the arm 65 and the speed change operation shaft 63 can be integrally rotated.

  A pinion 61 is engaged with the sector gear 62 on the speed change operation shaft 63. The pinion 61 can be rotated by a speed change actuator 60 made of an electric motor, and the speed change operation shaft 63 is rotated in the direction of arrow C in FIG. 6 or the direction of arrow D in FIG. It is configured to be able to.

  On the other hand, a front end portion of a speed change rod rod 67 extending in the front-rear direction is pivotally attached to the distal end portion of the arm 65 on the speed change operation shaft 63. A long slot 67a is formed in the rear end portion of the transmission rod rod 67 with a predetermined length in the front-rear direction. A pin 47a provided at the front end of the speed change arm 47 of the continuously variable transmission 21 is slidably fitted into the long groove hole 67a so that the rear end of the speed change rod rod 67 and the front end of the speed change arm 47 are engaged. Combined. The transmission arm 47 is interlocked and connected to the swash plate 24a (FIG. 3) of the hydraulic pump 24 via a trunnion shaft at its base.

  Thus, the continuously variable transmission 21 is configured such that when the speed change operation shaft 63 is not rotated and the speed change rod rod 67 is not moved backward, or when the speed change operation shaft 63 is rotated and the speed change rod rod 67 is moved rearward. However, when the movement amount does not exceed the predetermined length of the long slot 67a, the swash plate 24a of the hydraulic pump 24 is set to the neutral position without being tilted by the speed change arm 47 and the trunnion shaft, and directed toward the wheels 6 and 7. Thus, it is configured to be in a neutral state where no output is transmitted.

  In the continuously variable transmission 21, the speed change rod 63 is rotated in the direction of the arrow C in FIG. 6 with the speed change rod 67 being hardly moved rearward, and the speed change rod 67 is moved rearward. When the movement amount of the hydraulic pump 24 exceeds the predetermined length of the long slot 67a, the swash plate 24a of the hydraulic pump 24 is moved from the point of time to the rear of the transmission rod rod 67 by the transmission arm 47 and the trunnion shaft. By tilting, the gear ratio is changed to the speed increasing side, and the traveling speed is continuously increased.

  In the continuously variable transmission 21, the speed change rod 63 is rotated in the direction of arrow D in FIG. When 67 is moved forward, the swash plate 24a of the hydraulic pump 24 is moved by the transmission arm 47 and the trunnion shaft while the rearward movement amount of the transmission rod rod 67 exceeds the predetermined length of the long slot 67a. The speed change rod rod 67 is tilted based on the amount of forward movement to change the speed ratio to the speed reduction side, and the travel speed is continuously reduced.

  The shift operation shaft 63 is provided with second detection means 66 for detecting the tilt angle of the swash plate 24a of the hydraulic pump 24 in the continuously variable transmission 21 (the rotation angle of the shift actuator 60). The second detection means 66 is composed of an angle sensor such as a potentiometer, and is configured to detect the rotation angle of the speed change operation shaft 63.

  In addition, a shift pedal shaft 51 extends laterally at the front portion of the vehicle body frame 4 and is rotatably supported by a bearing. The shift pedal 16 is linked to the shift pedal shaft 51 via the linkage mechanism 50.

  The shift pedal 16 is urged by a spring means and is held at an initial position where the shift pedal 16 stands on the floor surface of the driving operation unit 10. For this speed change pedal 16, a stepping operation in which the operator depresses the speed change pedal 16 in the initial position with his / her foot forward, and a stepping release operation for removing the foot from the speed change pedal 16 in the state in which the driver has stepped on is performed. Is called.

  When the depressing operation is performed, the shift pedal 16 is rotated forward from the initial position against the spring means to rotate the shift pedal shaft 51 in the direction of arrow E in FIG. 5, while the depressing operation is performed. And is returned to the original initial position by the spring means, and is configured to rotate the shift pedal shaft 51 in the direction of arrow F in FIG.

  The shift pedal shaft 51 is provided with first detection means 55 for detecting the depression operation amount of the shift pedal 16. The first detection means 55 includes an angle sensor such as a potentiometer, and is configured to detect the rotation angle of the shift pedal shaft 51.

  In addition, the traveling transmission mission 20 is provided with a clutch mechanism 22 (FIG. 3) for transmitting or shutting off the output from the hydraulic continuously variable transmission 21 to the wheels 6 and 7, and for each wheel 6 and 7 is provided with a brake mechanism 23 (FIG. 3) for applying a braking force to 7.

  The travel transmission mission 20 is provided with a rotary operation shaft 45 for the brake mechanism 23. An operation member 46 is fixed to the operation shaft 45, and the operation member 46 and the operation shaft 45 can be rotated together. The operating member 46 is not only linked to the brake mechanism 23 but also linked to the clutch mechanism 22 via a wire or the like.

  A brake member 75 (FIG. 3) provided in the traveling machine body 3 is also interlocked with the brake mechanism 23. A clutch disengagement member 76 (FIG. 3) provided in the traveling machine body 3 is also linked to the clutch mechanism 22.

  When the operation member 46 rotates together with the operation shaft 45 and is in a predetermined rotation position, the operation member 46 is in a stop state in which the brake mechanism 23 is in an operation state and the clutch mechanism 22 is in a disengagement state. At a certain time, the brake mechanism 23 is brought into a non-operating state, and at the same time, the clutch mechanism 22 is put into a running state. The actuating member 46 is biased so as to be in a traveling state by a spring means.

  Thus, the receiving member 46 a is integrally provided on the operating member 46 for both the clutch mechanism 22 and the brake mechanism 23. A speed change rod rod 67 is slidably inserted in the receiving piece 46a in the front-rear direction. A stopper piece 67b is provided in a portion of the speed change rod rod 67 positioned rearward of the receiving piece 46a so that the stopper piece 67b and the receiving piece 46a can come into contact with each other.

  When the speed change operation shaft 63 is not rotated and the speed change rod rod 67 is not moved backward, that is, when the speed change pedal 16 is held at the initial position and the stepping operation is not performed, the actuating member 46 resists the spring means. As described above, the rotation is restricted by coming into contact with the stopper piece 67b, and the brake mechanism 23 is kept in the operating state and at the same time the clutch mechanism 22 is kept in the stopped state.

  When the speed change operation shaft 63 is rotated and the speed change rod rod 67 is moved rearward, that is, when the speed change pedal 16 is depressed, the actuating member 46 is moved in accordance with the rearward movement of the stopper piece 67b. It is rotated by the means to change to a running state in which the brake mechanism 23 is inactivated and at the same time the clutch mechanism 22 is in an engaged state.

  A brake shaft 70 extends in the lateral direction at the front portion of the vehicle body frame 4 and is rotatably supported by a bearing. The brake pedal 17 is interlocked with the brake shaft 70.

  The brake pedal 17 is urged by a spring means and is held at an initial position where the brake pedal 17 stands on the floor surface of the driving operation unit 10. With respect to the brake pedal 17, a stepping operation in which the operator depresses the brake pedal 17 in the initial position with his / her foot forward, and a stepping release operation in which the foot is removed from the brake pedal 17 in the state in which the driver has stepped on are performed. Is called.

  When the stepping operation is performed, the brake pedal 17 is rotated forward from the initial position against the spring means, and the brake shaft 70 is rotated in the direction of arrow M in FIG. The spring means is rotated rearward and returned to the original initial position, and the brake shaft 70 is configured to rotate in the direction opposite to the arrow M direction in FIG.

  An arm 71 is fixed to the brake shaft 70 at its base end. A front end portion of a brake rod rod 72 extending in the front-rear direction is pivotally attached to the distal end portion of the arm 71. The rear end portion of the brake rod rod 72 is inserted into the locking piece 46b of the operating member 46 so as to be slidable in the front-rear direction.

  The locking piece 46 b is provided integrally with the operating member 46. A stopper 72a is provided at a portion of the brake rod rod 72 positioned rearward of the locking piece 46b, and the stopper 72a and the locking piece 46b can be brought into contact with each other.

  When the brake shaft 70 is not rotated and the brake rod rod 72 is not moved forward, that is, when the brake pedal 17 is held at the initial position and the depression operation is not performed, the brake mechanism 23 of the operating member 46 is in an operating state. At the same time, free operation is permitted from a stopped state in which the clutch mechanism 22 is disengaged to a traveling state in which the brake mechanism 23 is inactivated and at the same time the clutch mechanism 22 is in the engaged state.

  When the brake shaft 70 is rotated and the brake rod rod 72 is moved forward, that is, when the brake pedal 17 is depressed, the actuating member 46 brings the brake mechanism 23 into a non-actuated state and the clutch mechanism 22 at the same time. If the travel state is in the on state, it is rotated against the spring means and is forcibly stopped regardless of the movement position of the speed change rod rod 67, that is, prior to the stepping operation of the speed change pedal 16. Changed to

  The traveling machine body 3 is provided with a control device 80 (FIG. 7). The control device 80 is connected to a first detecting means 55, a second detecting means 66, and a speed change actuator 60 comprising an electric motor. The control device 80 is further connected with a brake member 75 and a clutch disengagement member 76.

  The control device 80 detects the depression operation amount of the shift pedal 16 based on the first detection means 55, and the tilt angle of the swash plate 24a of the hydraulic pump 24 in the continuously variable transmission 21 is preset based on the detection result. The speed change actuator 60 is rotationally driven so that the set angle is set. The control device 80 is also configured to detect the tilt angle of the swash plate 24 a of the hydraulic pump 24 based on the second detection means 66.

  In such a configuration, when the depressing operation of the shift pedal 16 is not performed, the shift operation shaft 63 is not rotated and the shift rod rod 67 is not moved backward. Therefore, the transmission arm 47 of the continuously variable transmission 21 in the traveling transmission 20 is not rotated, and the swash plate 24a of the hydraulic pump 24 of the continuously variable transmission 21 is in the neutral position. That is, the continuously variable transmission 21 is in a neutral state in which no output is transmitted to the wheels 6 and 7.

  Moreover, when the shift pedal 16 is not depressed, the actuating member 46 is stopped, the brake mechanism 23 is activated, and the clutch mechanism 22 is disengaged. As a result, the output from the continuously variable transmission 21 (hydraulic / mechanical continuously variable transmission) to the wheels 6 and 7 is cut off. Therefore, the traveling machine body 3 is stopped without traveling.

  When the traveling machine body 3 is in a stopped state, when the shift pedal 16 is depressed, the shift pedal shaft 51 first rotates in the direction of arrow E in FIG. The rotation angle of the shaft 51 is detected. The control device 80 acquires the detection value of the first detection means 55 and detects the depression operation amount of the shift pedal 16 based on the detection value.

  Then, the speed change actuator 60 is driven to rotate in one direction by the control device 80 based on the stepping operation amount of the speed change pedal 16. As the speed change actuator 60 is driven to rotate, the speed change operation shaft 63 rotates in the direction of arrow C in FIG. 6, and the speed change rod rod 67 starts to move in the direction of arrow G in FIG.

  When the rearward movement amount of the transmission rod rod 67 exceeds the predetermined length of the long slot 67a on the rear end side, the stopper piece 67b moves rearward. As a result, the actuating member 46 whose rotation by the spring means is restricted by the stopper piece 67b is rotated to be in a running state, the brake mechanism 23 is inactivated, and the clutch mechanism 22 is in an engaged state. As a result, the output can be transmitted from the continuously variable transmission 21 to the wheels 6 and 7.

  At this time, the speed change arm 47 rotates rearward, and the swash plate 24a of the hydraulic pump 24 in the continuously variable transmission 21 has a trunnion so that the tilt angle thereof becomes a set angle corresponding to the stepping operation amount of the speed change pedal 16. Tilt through the axis. Thereby, the continuously variable transmission 21 changes its gear ratio to the speed increasing side, and transmits the shifted output to the wheels 6 and 7. Therefore, the traveling machine body 3 starts traveling.

  Subsequently, when the speed change rod rod 67 moves further rearward as the stepping operation amount of the speed change pedal 16 increases, the swash plate 24a of the hydraulic pump 24 in the continuously variable transmission 21 tilts to a larger set angle. . At this time, the control device 80 detects the tilt angle of the swash plate 24 a as needed based on the detection value of the second detection means 66. As a result, the continuously variable transmission 21 greatly changes the gear ratio on the speed increasing side, and transmits the shifted output to the wheels 6 and 7. Therefore, the traveling speed of the traveling machine body 3 is increased.

  In this state, when the depressing operation of the shift pedal 16 is performed, the shift pedal shaft 51 rotates in the direction of arrow F in FIG. 5, and the first detection means 55 detects the rotation angle of the shift pedal shaft 51 due to this rotation. To do. The control device 80 acquires the detection value of the first detection means 55 and detects the depression operation amount of the shift pedal 16 based on the detection value.

  Then, the speed change actuator 60 is rotationally driven in the direction opposite to the above based on the operation amount of the speed change pedal 16 by the control device 80. As the speed change actuator 60 is driven to rotate, the speed change operation shaft 63 rotates in the direction of arrow D in FIG. 6, and the speed change rod rod 67 moves in the direction of arrow H in FIG.

  As the transmission rod rod 67 moves forward, the transmission arm 47 rotates forward, and the tilt angle of the swash plate 24a of the hydraulic pump 24 in the continuously variable transmission 21 becomes the amount of depression of the transmission pedal 16. It tilts through the trunnion shaft so that the corresponding setting angle is obtained. As a result, the continuously variable transmission 21 changes its gear ratio to the deceleration side and transmits the shifted output to the wheels 6 and 7. Therefore, the speed of the traveling machine body 3 is reduced.

  When the transmission pedal 16 returns to the original initial position, the transmission arm 47 also returns to the original position, and the swash plate 24a of the hydraulic pump 24 of the continuously variable transmission 21 is set to the neutral position. Further, the operating member 46 is held in a stopped state by the stopper piece 67b of the speed change rod rod 67, so that the brake mechanism 23 is activated and at the same time the clutch mechanism 22 is disengaged. Therefore, the traveling of the traveling machine body 3 is stopped.

  Next, a configuration for changing the rotational speed of the engine 5 will be described.

  As shown in FIG. 6, a cam groove 62a is formed in the sector gear 62 so as to extend in the circumferential direction. Here, the cam groove 62a is arranged such that the start end portion is arranged at a predetermined distance from the speed change operation shaft 63 that is the center of the sector gear 62, and the end portion is located closer to the speed change operation shaft 63 than the start end portion. In addition, it is formed in an inclined shape so as to approach the speed change operation shaft 63 from the start end to the end.

  The cam groove 62a is slidably engaged with a distal end portion of a first arm 63c that is rotatably supported by the vehicle body frame 4 and extends from the horizontal shaft 63b. Then, the second arm 63d fixed to the horizontal shaft 63b is interlocked and connected to the accelerator lever 5a in the engine 5 via the wire 5b and the like.

  In this configuration, the first arm 63c moves along the cam groove 62a as the sector gear 62 rotates in the direction of the arrow C in FIG. 6, that is, the traveling speed increases, and the second arm associated therewith. The rotation of 63d causes the accelerator lever 5a to rotate in the direction of arrow J in FIG. 6 against its return spring means 5c. Accordingly, the rotational speed of the engine 5 is automatically increased in proportion to the increase of the traveling speed from the idle rotation.

  On the other hand, the first arm 63c moves along the cam groove 62a as the sector gear 62 rotates in the direction of arrow D in FIG. 6, that is, the traveling speed decreases, and the second arm 63d rotates accordingly. As a result, the accelerator lever 5a is rotated back by the return spring means 5c in the direction of arrow K in FIG. Accordingly, the rotational speed of the engine 5 is automatically decelerated in proportion to the deceleration of the traveling speed, and becomes idle when the traveling is stopped.

  Thus, in this embodiment, the rice transplanter 1 is configured to automatically change the rotational speed of the engine 5 in accordance with the speed change operation in the traveling speed change mission 20. The rice transplanter 1 is also configured to be able to arbitrarily change the rotational speed of the engine 5 by manually turning the accelerator lever 5a.

  Next, the control configuration will be described.

  As shown in FIG. 7, the control device 80 is connected with a first detection means 55, a second detection means 66, a maximum speed setter 77, a traveling speed detection means 86, and an engine speed detection means 87. The Also connected to the control device 80 are a speed change actuator 60, a display panel 15, an engine speed control means 85, a brake member 75, and a clutch disengagement member 76.

  The maximum speed setting unit 77 includes a dial or the like provided in the driving operation unit 10 and is configured to be able to set the maximum speed of the rice transplanter 1. The traveling speed detection means 86 is composed of a rotational speed sensor that detects the rotational speed of the axle or the like, and is configured to detect the traveling speed of the rice transplanter 1 from the detected value.

  The engine speed detector 87 includes a speed sensor that detects the speed of the output shaft of the engine 5 and is configured to detect the speed of the engine 5 from the detected value.

  Since the engine 5 in the rice transplanter 1 of the present embodiment is a diesel engine, the engine speed control means 85 includes a fuel injection device, and changes the fuel injection amount by changing the rack position by a solenoid. Apart from the mechanism using the accelerator lever 5a, the engine speed of the engine 5 can be adjusted and controlled. However, the engine speed control means is not particularly limited as long as it can adjust and control the engine speed according to the engine.

  The brake member 75 includes an electric motor or cylinder, a hydraulic cylinder controlled by an electromagnetic valve, or the like, and is configured to be able to switch the brake mechanism 23 from the non-operating state to the operating state by its operation. However, the brake member 75 is provided so that the brake device 23 can be operated without interfering with the operation of the brake mechanism 23 by the operating member 46.

  The clutch disengagement member 76 is composed of an electric motor or cylinder, a hydraulic cylinder controlled by an electromagnetic valve, or the like, and is configured so that the clutch mechanism 22 can be switched from the on state to the disengaged state by its operation. However, the clutch disengagement member 76 is provided so that the main clutch mechanism 22 can be operated without interfering with the operation of the clutch mechanism 22 by the operating member 46.

  Then, the control device 80 rotationally drives the speed change actuator 60 in accordance with the stepping operation amount of the speed change pedal 16 based on the first detection means 55 as described above, and the speed change ratio of the continuously variable transmission 21 by the speed change actuator 60. Configured to change. In addition, it is configured to perform the following control. In this control, the control device 80 first detects the depression operation amount of the shift pedal 16 based on the first detection means 55 and determines whether or not the shift pedal 16 is in the initial position.

  As a result, when the depressing operation of the speed change pedal 16 is performed and the speed change pedal 16 is returned to the initial position, that is, when the speed change pedal 16 is not operated, the control device 80 operates the brake member 75, The clutch disengagement member 76 is operated. The brake mechanism 23 is activated by the operation of the brake containing member 75, and the clutch mechanism 22 is deactivated by the operation of the clutch disengaging member 76.

  Further, when the stepping operation of the shift pedal 16 is performed and the shift pedal 16 is rotating, the control device 80 calculates a target traveling speed corresponding to the stepping operation amount of the shift pedal 16 at that time, After a predetermined time has elapsed, the target travel speed is compared with the actual travel speed based on the travel speed detection means 86, and it is determined whether or not the difference between the target travel speed and the actual travel speed is within an allowable range. To do.

  When the shift pedal 16 is depressed, the brake mechanism 23 is deactivated and the clutch mechanism 22 is engaged by the interlocking mechanism including the actuating member 46 as described above.

  As a result, when it is within the allowable range, the control device 80 determines that the operation of the transmission actuator 60 is normal. On the other hand, if it is not within the allowable range, control device 80 determines that the operation of transmission actuator 60 is abnormal, and causes display panel 15 to display that an operation abnormality of transmission actuator 60 has occurred. Thereby, the display panel 15 notifies the operator of the abnormal operation of the speed change actuator 60.

  In addition, at this time, the control device 80 determines whether or not the operation of the shift pedal 16, that is, whether or not the stepping operation or the stepping release operation is continuously performed, based on the first detection means 55. Determine based on.

  As a result, when the operation of the speed change pedal 16 is not continuously performed and the speed change pedal 16 is in a non-operating state, the control device 80 operates the brake member 75 and the clutch disengagement member 76. As a result, the brake mechanism 23 enters the operating state, and at the same time, the clutch mechanism 22 enters the disengaged state, the traveling speed is reduced, and the traveling is stopped.

  On the other hand, when the operation of the speed change pedal 16 is continued, the control device 80 causes the engine speed control means 85 to change the engine speed based on the engine speed detection means 87 to exceed the first predetermined value. It controls appropriately so that it may become below 2 predetermined value. These predetermined values of the engine speed are appropriately set in advance. Thereby, the engine speed in the engine 5 is limited to a predetermined range.

  Thereafter, the control device 80 compares the set travel speed set in advance by the maximum speed setter 77 with the actual travel speed based on the travel speed detection means 86, and the actual travel speed exceeds the set travel speed. It is determined whether or not.

  As a result, when the actual travel speed exceeds the set travel speed, the control device 80 again causes the engine speed control means 85 to cause the engine speed based on the engine speed detection means 87 to exceed the first predetermined value. It controls appropriately so that it may become below 2nd predetermined value. On the other hand, when the actual travel speed does not exceed the set travel speed, the control device 80 appropriately controls the engine speed control means 85 so that the engine speed is maintained within a predetermined range. Thus, the traveling is continued while the traveling speed is limited to a predetermined range with the set speed as the maximum speed.

  In the present embodiment, the means for detecting an operation abnormality of the speed change actuator 60 is configured using the control device 80, the first detection means 55, and the traveling speed detection means 86, but the present invention is not limited to this. For example, it is also possible to comprise using the control apparatus 80, the 1st detection means 55, and the 2nd detection means 66, for example.

  In this case, the control device 80 detects the target inclination angle of the swash plate 24a in the hydraulic pump 24 of the continuously variable transmission 21 corresponding to the depression operation amount of the transmission pedal 16 based on the first detection means 55, and the second detection means. 66, when the difference between the target inclination angle and the actual inclination angle is within the allowable range, the operation of the shift actuator 60 is determined to be normal, and when the difference is not within the allowable range, The operation of the speed change actuator 60 is determined to be abnormal.

  As described above, the rice transplanter 1 according to an embodiment of the present invention operates the continuously variable transmission 21 that changes the output of the engine 5 and transmits the output to the wheels 6 and 7 as a traveling device, and the operation of the shift pedal 16. A work vehicle including a speed change actuator 60 that changes the speed ratio of the continuously variable transmission 21 based on the amount, a brake mechanism 23 that applies a braking force to the front wheels 6, and the continuously variable transmission 21 to the front wheels 6 And a mechanical mechanism comprising a clutch mechanism 22 for transmitting or interrupting output to the rear wheel 7 and an operating member 46 for simultaneously switching the operating state of the brake mechanism 23 and the on / off state of the clutch mechanism 22 by operating the brake pedal 17. A mechanism 75, a brake member 75 for switching the brake mechanism 23 to an operating state, a clutch disconnecting member 76 for switching the clutch mechanism 22 to a disengaged state, and a speed change pedal And a control device 80 for operating the clutch disengagement member 76 so that the clutch mechanism 22 is disengaged at the same time as operating the brake-equipped member 75 so that the brake mechanism 23 is in the disengaged state. It is said.

  As a result, when an operation abnormality of the speed change actuator 60 occurs due to a failure or the like during traveling, the brake mechanism 23 is operated by operating the brake pedal 17 and at the same time the clutch mechanism 22 is turned off to reduce the traveling speed. Furthermore, traveling can be stopped. In addition, even when the operation of the brake pedal 17 is delayed, the brake mechanism 23 is automatically operated by operating the brake member 75 and the clutch disengaging member 76 by the control device 80 only by putting the speed change pedal 16 into the non-operation state. Simultaneously with the operation, the clutch mechanism 22 is turned off, the traveling speed can be reduced, and the traveling can be stopped. Therefore, even when an operation abnormality of the speed change actuator 60 occurs, the traveling speed can be reduced and traveling can be stopped quickly and reliably, and traveling stability can be ensured.

  Further, when the rice transplanter 1 is stopped, while the shift pedal 16 is not operated, the brake device 23 is operated by operating the brake member 75 and the clutch disengagement member 76 by the control device 80. At the same time, the clutch mechanism 22 is turned off, and the rice transplanter 1 can be kept stopped. Therefore, unintended start of traveling can be prevented. Even when the operation of the speed change actuator 60 has not occurred, the speed change pedal 16 is not operated as described above when it is desired to make a sudden stop when an obstacle is approaching immediately or when the vehicle is going over the fence. It is possible to stop traveling quickly and reliably.

  The rice transplanter 1 according to an embodiment of the present invention also includes an operation abnormality detection unit that detects an operation abnormality of the transmission actuator 60 and a display panel 15 that also serves as a notification unit that notifies the operation abnormality of the transmission actuator 60. When the operation abnormality detecting means detects an operation abnormality of the speed change actuator 60, the display panel 15 notifies the operator. For example, as described above, the operation abnormality detection unit is configured using the control device 80, the first detection unit 55, and the traveling speed detection unit 86.

  As a result, when an operation abnormality of the speed change actuator 60 occurs due to a failure or the like during traveling, the operator can recognize the operation abnormality. Therefore, it is possible to immediately cope with an abnormal operation of the speed change actuator 60 and to ensure running stability.

  The rice transplanter 1 according to an embodiment of the present invention includes an operation abnormality detection unit that detects an operation abnormality of the speed change actuator 60, and a fuel injection device (engine rotation speed) as a rotation speed control device that controls the engine rotation speed of the engine 5. Control means 85), and when the operation abnormality detection means detects an operation abnormality of the speed change actuator 60, the fuel injection device (engine speed control means 85) limits the engine speed to a predetermined value or less. The For example, as described above, the operation abnormality detection unit is configured using the control device 80, the first detection unit 55, and the traveling speed detection unit 86.

  As a result, even if an operation abnormality of the speed change actuator 60 occurs due to a failure or the like during travel, if the operation of the shift pedal 16 is continued and travel is not stopped, the engine speed is limited. Thus, the traveling speed can also be limited within a predetermined range. Therefore, traveling can be continued while preventing a rapid increase in traveling speed, and traveling stability can be ensured. As a result, for example, when traveling near the center of the field, the rice transplanter 1 can be escaped from the field even if an operation abnormality of the speed change actuator 60 occurs during work.

1 Rice transplanter (work vehicle)
5 Engine 15 Display panel (notification means)
DESCRIPTION OF SYMBOLS 16 Shift pedal 17 Brake pedal 21 Continuously variable transmission 22 Clutch mechanism 23 Brake mechanism 60 Shift actuator 66 Second detection means 75 Brake-in member 76 Clutch disengagement member 80 Control device 85 Engine speed control device

Claims (3)

A continuously variable transmission that shifts the output of the engine and transmits it to the traveling device;
A work vehicle including a speed change actuator that changes a speed ratio of the continuously variable transmission based on an operation amount of a speed change pedal;
A brake mechanism for applying a braking force to the traveling device;
A clutch mechanism for transmitting or interrupting output from the continuously variable transmission to the traveling device;
A mechanical interlocking mechanism that simultaneously switches the operating state of the brake mechanism and the on / off state of the clutch mechanism by operating a brake pedal;
A braked member that switches the brake mechanism to an activated state;
A clutch disengagement member that switches the clutch mechanism to an disengaged state;
A control device that operates the brake-engaging member so that the brake mechanism is in an activated state and simultaneously operates the clutch disengaging member so that the clutch mechanism is in a disengaged state when the shift pedal is not operated. Work vehicle.   An operation abnormality detection means for detecting an operation abnormality of the speed change actuator and a notification means for notifying an operation abnormality of the speed change actuator are provided, and the notification means when the operation abnormality detection means detects an operation abnormality of the speed change actuator. The work vehicle according to claim 1, wherein the work vehicle is notified to the operator.   An operation abnormality detection means for detecting an operation abnormality of the speed change actuator and an engine speed control device for controlling the engine speed of the engine are provided, and when the operation abnormality detection means detects an operation error of the speed change actuator, The work vehicle according to claim 1, wherein the engine speed is limited within a range of a predetermined value by the engine speed control device.

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