JP2005088700A - Travel operating device of working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a travel operating device of a working vehicle capable of enhancing the operability in the on-road traveling by effectively utilizing an existing configuration in a traveling device of the working vehicle in which the output of an engine is transmitted to the traveling device via a hydrostatic type continuously variable transmission. <P>SOLUTION: In the travel operating device of a working vehicle which is constituted to transmit the output of an engine 1 to a traveling device via a hydrostatic type continuously variable transmission 4 and has a neutral urging mechanism to urge the hydrostatic type continuously variable transmission 4 in a neutral condition by a manual operation tool 11 to operate the hydrostatic type continuously variable transmission 4, a rotary cam 19 interlocked with a rotary shaft 17 of the hydrostatic type continuously variable transmission 4, and a rocking positioning body 20 to be abutted on and urged by the rotary cam 19, an interlocking mechanism in which an operation unit 13 of an accelerator device 2 of the engine 1 is operated in the speed-increase side when the rocking positioning body 20 of the neutral urging mechanism is rocked as the speed-increasing operation of the hydrostatic type continuously variable transmission 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a traveling operation device for a work vehicle configured to transmit an output of an engine to a traveling device via a hydrostatic continuously variable transmission.

  This type of work vehicle is configured to adjust the traveling speed by operating the hydrostatic continuously variable transmission with the engine speed kept constant while holding the hand accelerator lever at an arbitrary operation position. There is a configuration in which an accelerator device of an engine is operated with a hand accelerator lever, and a hydrostatic continuously variable transmission is operated with a foot pedal. With this configuration, the engine speed can be kept constant by holding the hand accelerator lever at an arbitrary operating position regardless of the operation of the hydrostatic continuously variable transmission, so the travel speed can be changed when working on the field. Regardless, the work device can be driven at a constant speed.

  On the other hand, when traveling on the road for movement, the engine speed needs to be maximized or close to it due to a request for high-speed traveling. Furthermore, operations such as deceleration, stop, and standby are required to wait for traffic lights and turn left and right at intersections. In these situations, speed control is possible only with a hydrostatic continuously variable transmission, but the engine speed remains high at the time of traveling, so the engine noise is high and the fuel efficiency is deteriorated. Therefore, it is necessary to return to the low rotation position by the hand accelerator lever, which increases the number of operations. In addition, it is necessary to separately operate the hand accelerator lever again at the maximum or near position for starting and acceleration, and the number of operations is increased similarly.

  In order to solve these problems, there is one in which operability in running on the road is improved by means as shown in Patent Document 1. In Patent Document 1, when the changeover switch SW is set to the road running position, the vehicle speed control means C of the control device 15 acts, the engine speed N is detected by the speed detection sensor 17, and the detected engine is detected. Based on a characteristic that is calculated in advance so that the airframe traveling speed is proportional to the rotational speed N, the electric cylinder 11 is automatically driven so that the output of the stroke sensor 16 matches this characteristic, and the engine speed is increased. When the operation is performed, the electric cylinder 11 is automatically driven so that the airframe traveling speed changes proportionally with the increase in the engine speed, and the continuously variable transmission 4 is shifted to the speed increasing side. .

Japanese Patent Laid-Open No. 5-260828

  However, according to the configuration described in Patent Document 1, various sensors are used as a configuration in which the hydrostatic continuously variable transmission and the accelerator device of the engine are linked in order to eliminate the troublesome operation on the road. It is necessary to newly provide an electrical input / output device such as an electric cylinder and a computer processing device for controlling them. Such a configuration does not effectively use the existing configuration, and it can be said that a new independent configuration is added. There is a problem in terms of cost increase due to the addition of highly functional parts, and there is room for improvement.

  Therefore, the present invention provides a working traveling device configured to transmit the engine output to the traveling device via the hydrostatic continuously variable transmission, and effectively uses the existing configuration in traveling on the road. An object of the present invention is to simply configure a traveling operation device for a work vehicle with improved operability.

[I]
(Constitution)
According to a first aspect of the present invention, an engine output is transmitted to a traveling device via a hydrostatic continuously variable transmission, and includes a human operation tool for operating the hydrostatic continuously variable transmission. The hydrostatic continuously variable transmission includes a rotary cam that is linked to a rotary operation shaft of the hydraulic continuously variable transmission so as to be integrally rotatable, and a swingable swinging positioning body that is biased against the rotary cam. In the traveling operation device for a work vehicle provided with a neutral urging mechanism for urging the transmission to a neutral state, the configuration is as follows.
When the swing positioning body of the neutral urging mechanism swings with the speed increasing operation of the hydrostatic continuously variable transmission, the operation portion of the accelerator device of the engine is operated to the speed increasing side in conjunction with this. An interlocking mechanism for interlocking the swing positioning body and the operation unit is provided.

(Function)
According to the first aspect of the present invention, when the human operating tool is operated to move the work vehicle forward, the hydrostatic continuously variable transmission is speed-up via the rotational operation shaft of the hydrostatic continuously variable transmission, The rotation operation shaft rotates in the forward rotation direction together with the rotation cam. The swingable swinging positioning body applied and biased to the rotating cam swings as the rotating cam rotates in the forward rotation direction, and the distance from the rotation center of the rotating cam changes.

  On the other hand, when the manual operation tool is operated to move the work vehicle backward, the rotating operation shaft and the rotating cam of the hydrostatic continuously variable transmission rotate in the opposite direction to the operation for moving forward. Since the rotary cam is biased to the neutral state by the swing positioning body, there are two non-neutral states in the opposite direction with respect to the rotation direction of the rotary cam. That is, a non-neutral state in which the rotating cam rotates forward and a non-neutral state in which the rotating cam rotates reversely exist with a neutral state interposed therebetween. In any non-neutral state, the rotating cam is biased to the neutral state by the swing positioning body, so that the swing positioning body is directed against the bias as the rotating cam rotates from the neutral state. It will swing in the same direction. Therefore, the swing positioning body swings in the same direction as the forward operation even during the reverse operation in which the rotation cam is reversely rotated to transition to the non-neutral state, and the distance from the rotation center of the rotary cam is the same as during the forward operation. Change.

  Since the swing positioning body is interlocked with the operation portion of the accelerator device of the engine, the operation portion of the accelerator device of the engine is operated according to the swing of the swing positioning body by the forward or reverse speed increasing operation. Since the swing amount of the swing positioning body increases and decreases according to the operation amount of the artificial operation tool, the operation amount of the operation unit of the accelerator device also increases and decreases in conjunction with it.

(effect)
According to the first feature of the present invention, the operation amount of the operation unit of the accelerator device is configured to increase or decrease in accordance with the operation amount of the artificial operation tool without adding a new highly functional part. It is possible to change the traveling speed of the work vehicle for road driving that requires high-speed driving and stopping with reduced engine noise only by manipulating the manipulator, effectively using the existing configuration and cost It was possible to improve maneuverability while suppressing the rise.

[II]
(Constitution)
The second feature of the present invention resides in the following configuration in the first feature of the present invention.
A switching operation mechanism for switching the interlocking between the swing positioning body and the operation unit by the interlocking mechanism between the on state and the off state is provided.
(Function)
According to the second aspect of the present invention, the switching operation mechanism for switching the interlocking between the swing positioning body and the operation unit by the interlocking mechanism between the on state and the off state is provided. The function of the device can be selected.

(effect)
According to the second feature of the present invention, since the function of the traveling operation device for the work vehicle can be selected according to the traveling condition, the function of the work vehicle can be enhanced.

  Embodiments of the present invention will be described below with reference to the drawings.

  A riding-type agricultural tractor is shown in FIG. 1 as an example of a work vehicle. The riding-type agricultural tractor includes an engine 1 having a speed adjusting mechanism that adjusts a rotational speed, and a hydrostatic continuously variable transmission 4 (HST) that is linked to the engine 1 via a clutch housing 3 and can be switched between forward and reverse. A pair of left and right steerable front wheels 5, a pair of left and right drive rear wheels 6, a driver seat 7, a lift arm 8 for connecting the work devices, and a work device drive for transmitting drive force to the connected work devices A shaft 9 is provided. The output of the engine 1 transmitted to the hydrostatic continuously variable transmission 4 is branched into a working device transmission system and a traveling transmission system, and drives the working device drive shaft 9 and the driven rear wheel 6.

  As shown in FIG. 2, the tractor travel operation device includes an engine 1, an accelerator device 2 that sets the rotation speed of the engine 1, a hand accelerator lever 10 that can hold an operation position for operating the accelerator device 2, Interlocking mechanism that links the speed increasing operation of the step transmission 4, the foot pedal 11, which is an artificial operation tool for operating the hydrostatic continuously variable transmission 4, and the accelerator device 2 of the engine 1. The switching mechanism 12 is configured to switch the interlocking mechanism between the on state and the off state.

  The accelerator device 2 of the engine 1 includes an adjustment lever 13 that is an operation unit, and is urged by a coil spring 14 so that the rotational speed of the engine 1 is in an idling state. The adjusting lever 13 and the hand accelerator lever 10 are linked by a release wire 15, and when the hand accelerator lever 10 is operated to the speed increasing side, the adjusting lever 13 biased in an idling state increases the rotational speed of the engine 1. The hand accelerator lever 10 is configured to be held at a predetermined operation position by being linked in the direction.

  A rotary operation shaft 17 projects outside the housing of the hydrostatic continuously variable transmission 4, and a rotary cam 19 is attached to the end of the rotary operation shaft 17 via a connecting body 18 so as to be integrally rotatable. A rod 16 is connected to one end of the rotating cam 19, and the hydrostatic continuously variable transmission 4 and the foot pedal 11 are configured to be linked via the rod 16. A swing positioning body 20 having a pivot center about the axis P is oscillated and biased to a rotating cam 19 via a roller 23 by a spring 21 connected to an end on the swing rotation peripheral side. That is, the roller 23 of the swing positioning body 20 comes into contact with the V-shaped cam surface 22 formed on the rotating cam 19 and is pressed and biased against the V-shaped cam surface 22. 19 is oscillated and biased to the neutral position. With this configuration, the hydrostatic continuously variable transmission 4 is neutrally urged. When the foot pedal 11 is depressed forward and backward, the hydrostatic continuously variable transmission 4 is moved forward and backward from the neutral position. It is configured to operate steplessly in the shifting state.

  An interlocking mechanism that interlocks the speed increasing operation of the hydrostatic continuously variable transmission 4 with the accelerator device 2 of the engine 1 is configured as follows. A push-pull wire 26 is connected to the end portion of the swing positioning body 20 constituting the neutral urging mechanism, and the other end is connected to the input portion 25 of the switching operation mechanism 12 provided in the vicinity of the driver seat 7. Yes. On the other hand, the release wire 27 is connected to the end of the adjusting lever 13 of the accelerator device 2 of the engine 1, and the other end is connected to the output unit 24 of the switching operation mechanism 12. The switching operation mechanism 12 has a switching operation lever 28a at a position where it can be operated from the state of being seated on the driver seat 7. By operating the switching operation lever 28a, the speed increasing operation of the hydrostatic continuously variable transmission 4 and the engine The interlocking operation with one accelerator device 2 can be switched between the on state and the off state. Details are as follows.

  As shown in FIGS. 3 and 4, the switching operation mechanism 12 has an input unit 25 and an output unit 24, and a push-pull wire 26 and a release wire 27 are connected to each as described above. A convex rotator 29 having an output portion 24 fixed thereto and having a convex portion 31 in the rotational axis direction, and a switching operation lever adjacent to the convex rotator 29 so as to be slidable in the direction of the common axis 34 and relatively rotatable. The rotary slide member 28 having 28a, the concave rotary body 30 to which the input portion 25 is fixed, the concave portion 32 in the direction of the rotational axis and the spring 33 for pushing and biasing the concave portion 32 are provided. Are connected to each other so as to be relatively rotatable. The convex rotator 29 is slidable in the axial direction on the rotation support shaft 34, and the concave rotator 30 has a wall portion due to a reaction between the biasing spring 33 and the convex portion 31 of the convex rotator 29. It is pressed against the wall 35 and is always in contact with the wall 35. The tip end portion of the convex portion 31 of the convex rotary body 29 is inserted into the concave portion 32 of the concave rotary body 30, and the switching operation mechanism is in a state where the front end surface of the convex portion 31 abuts against the spring 33 and is pushed and biased. 12 is constituted. The convex rotary body 29 is provided with a pin 36 protruding outward on the convex portion 31 in a direction orthogonal to the rotation support shaft 34, and the concave rotation body 30 has a recess in the direction orthogonal to the rotation support shaft 34. An engagement groove 37 is provided in the end face of 32.

  When the switching operation lever 28a is operated and the convex rotating body 29 is slid against the urging force in the axial direction via the rotary slide member 28, as shown in FIG. The pin 36 included in the body 29 and the engagement groove 37 included in the concave rotator 30 are engaged, so that the convex rotator 29 and the concave rotator 30 can rotate together. At this time, the switching operation mechanism 12 is turned on, and the release wire 27 connected to the output unit 24 is also operated by pulling the push-pull wire 26 connected to the input unit 25. In the state where the pin 36 and the engaging groove 37 are not engaged due to the pushing bias, that is, in the case shown in FIG. 3 (a), the convex rotating body 29 and the concave rotating body 30 cannot be integrally rotated and switched. The operation mechanism 12 is turned off, and the link between the push-pull wire 26 and the release wire 27 is cut off.

  In the cut state, since the input unit 25 is connected to the swing positioning body 20 by the push-pull wire 26, the concave rotary body 30 also returns to the neutral position every time the swing positioning body 20 returns to neutral. On the other hand, since the convex rotating body 29 is also returned to the neutral position in conjunction with the adjustment lever 13 biased to the idling state, the same phase is obtained when switching from the cut state to the on state. When the convex rotary body 29 is slid by the switching operation lever 28a and the pin 36 and the engagement groove 37 are to be engaged, the engagement is possible.

  The switching operation lever 28a is in the state where the pin 36 and the engagement groove 37 are engaged with each other by sliding the convex rotary body 29 against the pushing biasing force of the spring 33 incorporated in the concave rotary body 30, that is, the engaged state. Since the notch 38 is provided in the outer wall 35 of the switching operation mechanism 12, it is possible to hold the switching operation mechanism 12 in the on state against urging.

  When moving between fields or traveling on the road, the hand accelerator lever 10 is set in advance to a low-speed rotation state, and the switching operation mechanism 12 is switched to the on state, so that the foot pedal 11 is moved forward. Alternatively, when the reverse operation is performed, the rotation speed of the engine 1 is increased according to the operation amount by the above-described linkage mechanism, and the traveling speed is increased. When the foot pedal 11 is returned to the neutral position, the rotational speed of the engine 1 decreases and stops. Specifically, it operates as follows.

  The stepping operation of the foot pedal 11 toward the forward side or the reverse side is converted into a forward or reverse rotation of the rotary cam 19 by the linkage of the rod 16 and the rotary cam 19. The swing positioning body 20 that is neutrally urged to the V-shaped cam surface 22 via the roller 23 by the rotation operation of the rotary cam 19 resists neutral urging regardless of the rotation direction of the rotary cam 19. It is swung, and transitions to a non-neutral state with the speed increasing operation of the hydrostatic continuously variable transmission 4. The swing amount at this time varies according to the speed increasing operation amount of the hydrostatic continuously variable transmission 4, that is, the stepping operation amount of the foot pedal 11. The adjustment lever 13 of the accelerator device 2 is connected to the release wire 27 via the switching operation mechanism 12 that is in the engaged state by the linkage of the oscillation positioning body 20 and the push-pull wire 26. To increase the rotational speed of the engine 1.

  If the switching operation mechanism 12 is set to the on state, the foot pedal 11 and the adjustment lever 13 are linked as described above, and the adjustment lever 13 is speed-controlled in conjunction with the depression operation of the foot pedal 11. Therefore, if the travel speed is changed according to the depression amount by operating the foot pedal 11 to move forward or backward, the engine 1 is adjusted to the rotational speed corresponding to the depression amount.

  If the switching operation mechanism 12 is set to the cut-off state, the foot pedal 11 and the adjustment lever 13 are disconnected from each other, and the adjustment lever 13 is speed-controlled only by the hand accelerator lever 10. Therefore, it is possible to change the vehicle speed only by the hydrostatic continuously variable transmission 4 that is not linked to the rotational speed of the engine 1.

[Another Embodiment of the Invention]
The switching operation mechanism 12 in the above-described embodiment can be configured as shown in FIGS. That is, the swing positioning body 20 interlocked with the speed increasing operation of the foot pedal 11 is combined with the swing body 39 that is configured to be able to swing integrally with the pressing member 40 and the swing axis P is common. 20 so as to be able to rotate relative to 20. The pressing member 40 is urged to the cut state by the urging spring 41, and the switching operation lever 43 linked by the release wire 42 is operated against the urging to switch between the on state and the cut state. It is configured to be possible. Since the notch 44 is provided so as to hold the position of the switching operation lever 43 in the closed state against the biasing spring 41, the switched operation mechanism 12 can be held in the closed state.

  As shown in FIG. 5B, when the switching operation mechanism 12 is in the engaged state, the contact portion 45 of the pressing member 40 and the swing positioning body 20 are frictionally engaged, and the swing positioning body 20 is When the foot pedal 11 swings in response to a stepping operation before and after the foot pedal 11, the double rocking body 39 swings integrally with the rocking positioning body 20 with the axis P as the rocking center via the pressing member 40. Since the double oscillating body 39 is linked to the adjusting lever 13 of the accelerator device 2 by the release wire 46, the adjusting lever 13 is operated in conjunction with the swing of the swing positioning body 20. Accordingly, the adjustment lever 13 provided in the accelerator device 2 of the engine 1 is operated according to the depression amount of the foot pedal 11, and the rotational speed of the engine 1 is adjusted according to the change in the vehicle speed of the work vehicle.

  As shown in FIG. 5 (a), when the switching operation mechanism 12 is in the cut state, the inner part of the release wire 42 is slack, and the contact portion 45 of the pressing member 40 including the biasing spring 41 is The swing positioning body 20 is not engaged with the swing positioning body 20, and the swing of the swing positioning body 20 does not act on the adjustment lever 13 provided in the accelerator device 2 of the engine 1. Therefore, the rotational speed of the engine 1 is governed by the operation of the hand accelerator lever 10, and a predetermined engine speed can be set and held.

  In any of the above-described embodiments, the rod 16 is connected to the rotating cam 19 so that the foot pedal 11, which is an artificial operation tool, is linked to the swing positioning body 20. The rod 16 may be connected to a member, for example, a connecting body 18.

Side view of tractor Operation system diagram of travel operation device Cross-sectional view of switching operation mechanism (A) Cutting state (B) Entering state Top view of the switching operation mechanism in the cut state Operation system diagram of switching operation tool in another embodiment (b) Cutting state (b) Entered state Plan view of neutral urging mechanism and switching operation mechanism in another embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Accelerator apparatus 4 Hydrostatic continuously variable transmission 11 Artificial operation tool 12 Switching operation mechanism 13 Operation part 17 Rotation operation shaft 19 Rotation cam 20 Swing positioning body

Claims (2)

The output of the engine is configured to be transmitted to the traveling device via a hydrostatic continuously variable transmission, and includes a manipulator for operating the hydrostatic continuously variable transmission, and the hydrostatic continuously variable transmission The hydrostatic continuously variable transmission is brought into a neutral state by a rotary cam that is linked to the rotary operation shaft of the rotary shaft and a swingable positioning member that is urged against the rotary cam. A traveling operation device for a work vehicle provided with a neutral biasing mechanism for biasing,
When the swing positioning body of the neutral urging mechanism swings in accordance with the speed increasing operation of the hydrostatic continuously variable transmission, the operation unit of the accelerator device of the engine is operated to the speed increasing side in conjunction with this. As described above, a traveling operation device for a work vehicle including an interlocking mechanism for interlocking the swing positioning body and the operation unit.   The traveling operation device for a work vehicle according to claim 1, further comprising a switching operation mechanism that switches between interlocking of the swing positioning body and the operation unit by the interlocking mechanism between an on state and a off state.

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