JP2013023099A - Working vehicle with hydraulic continuously variable transmission mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a working vehicle with a hydraulic continuously variable transmission, configured to allow a forward transmission pedal to be held at a desired position.SOLUTION: A tractor 10 with a hydraulic continuously variable transmission 20, which includes a forward transmission pedal 27F, a backward transmission pedal 27B, an oscillating plate 54 interlocking with the forward transmission pedal 27F and backward transmission pedal 27B, and a trunnion arm TA interlocking with the oscillating plate 54. The tractor has an auto-cruising mechanism composed of a metal stop plate 71 installed at a lower section of the forward transmission pedal 27F, and electromagnet 72 which is arranged at a predetermined distance from the stop plate 71 and installed in a vehicle body frame 11. The forward transmission pedal 27F is held at a desired depression amount by absorbing the electromagnet 72 to the stop plate 71 when a desired travel speed is obtained by depressing the forward transmission pedal 27F.

Description

  The present invention relates to a working vehicle having a hydraulic continuously variable transmission mechanism.

  A tractor (work vehicle) having a conventional hydraulic continuously variable transmission is interlocked with a forward transmission pedal (forward operation means), a reverse transmission pedal (reverse operation means), a forward transmission pedal, and a reverse transmission pedal. A shift operation unit and a trunnion arm interlocked with the shift operation unit are provided. An auto-cruise mechanism is provided for holding the forward shift pedal in a state where it is depressed by a certain amount.

JP 2008-74128 A

  The auto-cruise mechanism disclosed in Patent Document 1 includes an auto-cruise operation lever in the vicinity of a driver's seat, a gear connected to a lower portion of the auto-cruise operation lever, and a gear attached to a rotation shaft of a forward shift pedal. And the forward shift pedal is kept rotating. However, in the auto-cruise mechanism having such a configuration, the holding position of the forward shift pedal is limited by the distance between the gears attached to the rotating shaft of the forward shift pedal, and the driver performs forward shift at a desired position. There was a problem that the pedal could not be held. Accordingly, an object of the present invention is to provide a working vehicle capable of holding the forward operation means at a desired position.

For this reason, the invention according to claim 1 is a forward operation means;
Reverse operation means;
A speed change operation unit interlocked with the forward operation means and the reverse operation means;
In a working vehicle having a hydraulic continuously variable transmission including a trunnion arm interlocked with the speed change operation unit,
A metal attracted part attached to the lower part of the forward operation means;
An auto cruise mechanism is configured with a magnet arranged at a certain distance from the attracted portion and attached to the body frame,
When the forward operation means is operated to achieve a desired traveling speed, the forward operation means is held at a desired operation position by attracting the magnet to the attracted portion.

According to a second aspect of the present invention, in the working vehicle having the hydraulic continuously variable transmission according to the first aspect, the magnet is an electromagnet, and includes a switch for turning on and off the magnetic force of the electromagnet.
When the forward operation means is operated to achieve a desired traveling speed, the switch is turned on to generate a magnetic force in the electromagnet, and the electromagnet is attracted to the attracted portion to thereby change the forward operation means. It is characterized by being held at a desired operation position.

According to a third aspect of the present invention, the working vehicle having the hydraulic continuously variable transmission according to the first aspect includes a set of transmission portions that are respectively linked to the forward operation means and the reverse operation means. ,
A working vehicle having a hydraulic continuously variable transmission that opens and closes an engine throttle valve by operating the transmission unit,
The transmission unit includes a switching unit,
The switching unit selects whether to transmit the operation of the transmission unit to the engine throttle valve.

  According to a fourth aspect of the present invention, in the working vehicle having the hydraulic continuously variable transmission according to the third aspect, the transmission portion is made of a wire.

  According to the first aspect of the present invention, the forward operation means, the reverse operation means, the speed change operation unit interlocked with the forward operation means and the reverse operation means, and the trunnion interlocked with the speed change operation unit In a working vehicle having a hydraulic continuously variable transmission including an arm, a metal attracted portion attached to a lower portion of the forward operation means, and a certain distance from the attracted portion, and An auto cruise mechanism is configured with a magnet attached to a vehicle body frame, and when the forward operation means is operated to achieve a desired traveling speed, the forward operation is performed by attracting the magnet to the attracted portion. The means is held in the desired operating position.

  For this reason, the driver | operator can hold | maintain the forward operation means in a desired position with the combination of a magnet and a to-be-adsorbed part. That is, until now, the holding position of the forward operation means has been limited by the gear interval or the like, but the driver can set the auto cruise at a desired forward speed. Therefore, it is possible to provide a working vehicle having a hydraulic continuously variable transmission that can hold the forward operation means at a desired position. In addition, the number of components can be reduced as compared with the use of gears and the like, and the auto-cruise mechanism can be reduced in size. Therefore, it is possible to provide a working vehicle having a hydraulic continuously variable transmission that can realize an auto-cruise mechanism having a compact and simple configuration.

  According to a second aspect of the present invention, the magnet is an electromagnet, and includes a switch for turning on / off the magnetic force of the electromagnet. The switch is turned on to generate a magnetic force in the electromagnet, and the electromagnet is attracted to the attracted portion, thereby holding the forward operation means at a desired operation position.

  As a result, the magnet can be attracted to the attracted part simply by turning the switch ON / OFF, facilitating the operation.

  According to a third aspect of the present invention, there is provided a pair of transmission portions that are respectively interlocked with the forward operation means and the reverse operation means, and the hydraulic operation mechanism opens and closes the engine throttle valve by operating the transmission portions. A working vehicle having a continuously variable transmission, wherein the transmission unit includes a switching unit, and the switching unit selects whether to transmit the operation of the transmission unit to the engine throttle valve.

  Therefore, when the hydraulic continuously variable transmission is operated, it is possible to easily select whether or not to increase the engine output by opening the engine throttle valve when the hydraulic continuously variable transmission is operated.

  According to the invention described in claim 4, since the transmission unit is made of a wire, the transmission unit can be configured with a simple configuration. Moreover, since the configuration is simple, the risk of failure can be reduced. Furthermore, by using the wire, it is possible to effectively utilize the gap inside the complicated working vehicle. For this reason, when using a link bar etc. as a transmission part, it was necessary to ensure a space linearly, but by using a wire, a working vehicle can be made compact.

1 is a side view of a tractor as an example of a working vehicle having a hydraulic continuously variable transmission according to the present invention. It is the principal part top view. It is a partial enlarged view of a driver's seat floor. It is a figure for demonstrating the link mechanism of a forward transmission pedal and a reverse transmission pedal. It is the elements on larger scale of FIG. It is a figure for demonstrating a motion of a rocking | fluctuation plate, (a) is a neutral position, (b) is a figure when a forward shift pedal is stepped on, (c) is a figure when a reverse shift pedal is stepped on It is. (A) is a figure for demonstrating the positional relationship of the link member 46 and the wire W1 in the state of (b) of FIG. 6, (b) is the link member 45 in the state of (c) of FIG. It is a figure for demonstrating the positional relationship of a wire W2. It is a figure for demonstrating an interlocking lever. It is a figure for demonstrating the frame structure of a driver's seat floor. (A) is a figure for demonstrating attachment of the link plate and stop plate of a forward gearshift pedal, (b) is a components figure of a stop plate. (A) is a schematic plan view for demonstrating attachment of the link plate and stop plate of a forward gearshift pedal, (b) is sectional drawing seen from the X arrow of (a).

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings. FIG. 1 is a side view of a tractor 10 as a working vehicle having a hydraulic continuously variable transmission according to the present invention, and FIG. The tractor 10 includes a pair of front tires (front wheels) 12, 12 and a pair of rear tires (rear wheels) 13, 13 before and after the body frame 11. A bonnet 14 is disposed above the front tires 12 and 12, and an engine E as a drive unit is provided on the inside thereof. A handle column 15 is provided behind the bonnet 14, and a handle 16 projects upward from the handle column 15. A left brake pedal 17A and a right brake pedal 17B are provided below the right side of the handle column 15.

  A driver seat 25 is provided behind the handle column 15. Fenders 24 and 24 are provided on the left and right sides of the driver seat 25. The fender 24 is provided so as to cover a part of the rear tire 13. A driver seat floor 22 is provided in front of the driver seat 25. The driver's seat floor 22 is supported by the frame 21. Below the frame 21, the hydraulic continuously variable transmission 20 is attached to the vehicle body frame 11 via a link plate 26. A transmission case TM is connected and attached to the rear portion of the hydraulic continuously variable transmission 20. The mission case TM is located below the driver seat 25.

  The driver seat floor 22 on the right side includes a forward transmission pedal 27F and a reverse transmission pedal 27B linked to the hydraulic continuously variable transmission 20. In addition, an interlocking lever (switching unit) 31 for turning on and off the interlocking of the forward shift pedal 27F, the reverse shift pedal 27B, and the throttle of the engine E is provided below the right side of the dashboard 32.

  Next, the link mechanism of the forward transmission pedal (forward operation means) 27F and the reverse transmission pedal (reverse operation means) 27B will be described with reference to FIGS. The lower end of the forward shift pedal 27F is fixed to the link plate 41 via bolts. The link plate 41 is rotatably attached to the bracket B1 with a bolt at a rotation fulcrum C1. One end of a link bar 43 is rotatably attached to the end of the link plate 41. The other end of the link bar 43 is rotatably attached to the link member 45. A wire W <b> 2 is fixed to the lower end of the link member 45. The wire W2 extends to an interlocking lever that will be described later.

  On the other hand, the lower end of the reverse shift pedal 27B is fixed to the link plate 42 via bolts. The link plate 42 is rotatably attached to the bracket B1 with a bolt at a rotation fulcrum C2. One end of a link bar 44 is rotatably attached to the end of the link plate 42. The other end of the link bar 44 is rotatably attached to the link member 46. A wire W <b> 1 is fixed to the lower end of the link member 46. The wire W1 extends to an interlocking lever that will be described later.

  The link member 45 is fixed to the rotation shaft 48. On the other hand, the link member 46 is attached to the rotation shaft 48 so as to be rotatable (that is, the rotation shaft 48 does not rotate even if the link member 46 rotates). One end of a connecting member 47 is rotatably attached to the link member 46. The other end of the connecting member 47 is rotatably attached to the link member 50. The link member 50 is fixed to the rotation shaft 49.

  The rotation shafts 48 and 49 are rotatably attached to the holding plate 52. The holding plate 52 is fixed to the frame 60 via the bracket 51, and is fixed to the right side surface of the transmission case TM with a bolt BT1. Note that one end of a swing plate (transmission operation unit) 54 is fixed to the rotation shaft 48. The swing plate 54 has a recess 54M.

  On the other hand, another rocking plate 55 is rotatably fixed to the right side surface of the mission case TM via a rotation pin 56. A disc-shaped contact member 57 is fixed to the swing plate 55, and the side portion 54 </ b> B of the swing plate 54 is brought into contact with the outer periphery of the contact member 57. Specifically, the coil spring S1 is attached to one end of the swing plate 55, and the swing plate 55 is urged to rotate in the forward direction of the tractor 10 with the rotation pin 56 as a fulcrum. Accordingly, the contact member 57 is configured to always press the side portion 54B of the swing plate 54. When the contact member 57 is positioned in the recess 54M, the tensile force of the coil spring S1 is the smallest (this position is defined as a neutral position). When the abutting member 57 moves slightly away from the recess 54M to the left or right and moves the side portion 54B, the swing plate 55 rotates rearward to extend the coil spring S1 and increase the tensile force. For this reason, the swing plate 55 is operated so that the side portion 54B of the swing plate 54 is strongly pressed through the contact member 57, and the contact member 57 returns to the depression 54M (that is, the neutral position).

  As shown in FIG. 5, a locking member 45 </ b> A is fixed to the lower portion of the link member 45. The locking member 45A is a metal plate, and its side portion is fixed to the surface of the link member 45 by welding or the like. A through hole is formed in the locking member 45A, and the wire W2 is passed through and held in the through hole. The through hole is formed slightly larger than the diameter of the wire W2. Further, the wire W2 and the locking member 45A are not fixed. A cylindrical Tyco End T2 is formed at the tip of the wire W2. This Tyco end T2 prevents the wire W2 from falling off the locking member 45A (the Tyco end T2 is prevented from coming off). The Tyco end T2 and the locking member 45A are not fixed.

  Similarly, a locking member 46 </ b> A is fixed to the lower portion of the link member 46. The locking member 46A is a metal plate, and its side portion is fixed to the link member 46 on the surface by welding or the like. A through hole is formed in the locking member 46A, and the wire W1 is passed through and held in the through hole. The through hole is formed to be slightly larger than the diameter of the wire W1. Further, the wire W1 and the locking member 46A are not fixed. A cylindrical Tyco end T1 is formed at the tip of the wire W1. This Tyco end T1 prevents the wire W1 from falling off the locking member 46A (the Tyco end T1 is prevented from coming off). The Tyco end T1 and the locking member 46A are not fixed.

  On the other hand, the link plate 59 is fixed to the rotating shaft 49 (the link plate 59 is shown in FIG. 6A). One end of the link plate 59 is biased by a spring so as to always come into contact with a rotating member (not shown). The rotating member is disposed in parallel to the swing plate 54 and is fixed to the rotating shaft 48. Therefore, it rotates in synchronization with the swing plate 54.

  One end of a link bar 58 is rotatably attached to the lower end of the swing plate 54. The other end of the link bar 58 is rotatably attached to one end of a trunnion arm TA projecting from the right side surface of the hydraulic continuously variable transmission 20. A trunnion shaft T is fixed to the other end of the trunnion arm TA. As the trunnion shaft T rotates, the swash plate in the hydraulic continuously variable transmission 20 tilts, changes the discharge amount from the hydraulic pump and the motor output, and inputs it into the transmission case TM to change the engine output. Is configured to do. When the trunnion shaft T rotates forward (clockwise in FIG. 4), the vehicle travels forward, and the speed increases as the rotation amount of the trunnion shaft T increases. On the other hand, when the trunnion shaft T rotates backward (counterclockwise in FIG. 4), the vehicle travels backward, and the speed increases as the rotation amount of the trunnion shaft T increases. Note that the state of the trunnion arm TA in FIG. 4 is the neutral (non-operating) position.

  6A shows a state in which neither the forward shift pedal 27F nor the reverse shift pedal 27B is depressed, and the contact member 57 is disposed in the recess 54M (neutral position).

  Since it is configured in this way, when the forward shift pedal 27F is depressed, the link plate 41 rotates backward about the rotation fulcrum C1. As a result, the link bar 43 is pushed rearward, the lower end of the link member 45 is pushed rearward, and the turning shaft 48 turns forward. As a result, the swing plate 54 rotates forward as shown in FIG. Then, the link bar 58 is pulled backward, and the lower end of the trunnion arm TA is pulled backward. As a result, the trunnion shaft T rotates forward, the hydraulic continuously variable transmission 20 enters the forward mode, and the speed increases as the rotation amount of the trunnion shaft T increases. At this time, the rotating member fixed to the rotating shaft 48 also rotates forward in synchronization with the swing plate 54. Then, the link plate 59 in contact with this rotates backward. Since the rotation shaft 49 fixed to the link plate 59 also rotates rearward, the link bar 44 is pushed forward via the connecting member 47 and the link member 46, and the reverse shift pedal 27B is rotated in the direction of returning. Move. In addition, since the lower end of the link member 45 is pushed back, the wire W1 is pulled back. On the other hand, the lower end of the link member 46 is pushed forward, but the Tyco end T1 only floats from the locking member 46A and does not push the wire W1 forward (see FIG. 7A).

  When the foot is released from the forward shift pedal 27F, the force applied to the link plate 41 and the link bar 43 is released. As a result, the force applied to the rotating shaft 48 and the swing plate 45 is also released. On the other hand, since the urging force is applied to the swing plate 55 by the coil spring S1, the swing plate 54 is moved so that the contact member 57 attached to the swing plate 55 returns to the recess 54M. That is, the swing plate 54 rotates from the position shown in FIG. 6B to the neutral position shown in FIG. Along with this, the link bar 58 is pushed forward, and the lower end of the trunnion arm TA is pushed forward. As a result, the trunnion shaft T rotates rearward to the neutral position, and the forward movement mode ends.

  On the other hand, when the reverse shift pedal 27B is depressed, the link plate 42 rotates backward about the rotation fulcrum C2. As a result, the link bar 44 is pushed rearward, and the link member 46 moves rearward. At this time, the link member 46 rotates independently without rotating the rotation shaft 48. The rotation shaft 49 rotates forward via the link member 50 connected to the link member 46. As a result, the link plate 59 rotates forward and pushes a rotating member (not shown) fixed to the rotating shaft 48 forward. For this reason, the rotation shaft 48 rotates rearward, and the lower end of the swing plate 54 fixed to the rotation shaft 48 is rotated forward (FIG. 6C). As a result, the link bar 58 is pushed forward, and the lower end of the trunnion arm TA is pushed forward. As a result, the trunnion shaft T rotates rearward, the hydraulic continuously variable transmission 20 enters the reverse mode, and the speed increases as the rotation amount of the trunnion shaft T increases. When the rotation shaft 48 is rotated rearward, the lower end of the link member 45 is rotated so as to be directed forward, and the link bar 43 is pushed forward to be rotated in a direction in which the forward shift pedal 27F is returned. Since the lower end of the link member 46 moves rearward, the wire W1 is pulled rearward. On the other hand, the lower end of the link member 45 moves forward, but the Tyco end T2 only floats from the locking member 45A and does not push the wire W2 forward (see FIG. 7B).

  When the foot is released from the reverse shift pedal 27B, the force applied to the link plate 42 and the link bar 44 is released. As a result, the force applied to the rotating shaft 49 and the link plate 59 is also released, and further, the force applied to the swing plate 54 is also released. On the other hand, since the urging force is applied to the swing plate 55 by the coil spring S1, the swing plate 54 is moved so that the contact member 57 attached to the swing plate 55 returns to the recess 54M. That is, the swing plate 54 is rotated from the position shown in FIG. 6C to the neutral position shown in FIG. Along with this, the link bar 58 is pulled backward, and the lower end of the trunnion arm TA is pulled backward. As a result, the trunnion shaft T rotates forward to the neutral position, and the reverse drive mode ends.

  Next, the interlocking lever 31 will be described with reference to FIG. The interlocking lever 31 is for turning on and off the interlocking of the wires (transmission parts) W1, W2 and the wire (transmission part) W3 by moving the handle 31a in the guide groove 31c (FIG. 8 shows the wire W1, W2 and wire W3 are shown in a disconnected state). The wire W3 is connected to an engine throttle valve valve (not shown), and when the wire W3 is pulled, the engine throttle valve is opened to supply more fuel to the engine E and increase the output of the engine E. Yes. When the handle 31a is moved to the front side in the drawing, the interlock is entered, the interlock bar provided in the link bar 31d is fitted into the link plate 31b, the link plate 31b and the link bar 31d are integrated, and the rotation shaft 31e. It becomes possible to rotate around the fulcrum.

  When the forward shift pedal 27F (or the reverse shift pedal 27B) is depressed, the link member 45 (or link member 46) rotates rearward and pulls the wire W2 (or wire W1) toward the rear. Then, the link bar 31d connected to the wire W2 rotates downward. Since the link bar 31d and the link plate 31b are interlocked, the link plate 31b is also rotated downward, the wire W3 is pulled, and the engine throttle valve is opened.

  When the handle 31a is moved as shown in FIG. 6, the interlock is turned off, and the interlock between the wires W1, W2 and the wire W3 is cut off. Does not work with.

  9-11, the auto-cruise mechanism for the forward shift pedal 27F will be described. The link plate 41 that connects the forward shift pedal 27F is provided with two through holes. On the other hand, a stop plate (adsorbed portion) 71 made of a metal plate is provided with two through holes 71H and 71H. The link plate 41 and the stop plate 71 are connected by a bolt by combining the through hole 71H and the through hole of the link plate 41. The stop plate 71 is provided with a notch 71C.

  A frame 62 projects from the right side surface of the hydraulic continuously variable transmission 20, and the frames 62 are provided with frames 60 and 64 projecting in a substantially right angle direction. The other end of the frame 60 is supported by a bracket 61. The bracket 61 is attached so as to overhang the mission case TM. The driver's seat floor 22 is placed on the bracket 61 and the frames 60, 62, 64.

A bracket 73 is attached to the frame 64 with bolts, and an electromagnet (magnet) 72 for attracting the stop plate 71 is attached to the bracket 73 with bolts. The electromagnet 72 can be turned ON / OFF by a switch. This switch is arranged at a position that can be reached by the driver who is seated in the driver's seat 25. The electromagnet 72 is arranged so that it can be adsorbed in the expected adsorption area 71Z when the stop plate 71 rotates, and is arranged with a slight gap (a constant distance) Δd slightly outside the stop plate 71. Is done. The notch C1 is continuously formed in the suction planned area 71Z.

  When the forward shift pedal 27F is depressed, the hydraulic continuously variable transmission 20 is operated according to the procedure described above. When the forward shift pedal 27F is depressed, the stop plate 71 also rotates about the rotation fulcrum C1. When the depressing amount of the forward shift pedal 27F reaches a certain amount, the electromagnet 72 is positioned in the expected adsorption area 71Z in a side view. When it is desired to maintain the depression amount of the forward shift pedal 27F at the desired travel speed (that is, when the trunnion shaft T is desired to be held at a desired position), the driver turns on the switch to turn on the electromagnet. A magnetic force is generated in 72, and the electromagnet 72 is attracted to the stop plate 71. Even if the forward shift pedal 27F is released in this state, the forward shift pedal 27F does not return because the electromagnet 72 attracts and holds the stop plate 71. This state is an auto cruise state. Thus, the combination of the electromagnet 72 and the stop plate 71 allows the driver to fix the forward shift pedal 27F at a desired position. That is, until now, the holding position of the forward shift pedal has been determined by the gear interval or the like, but the driver can set auto-cruise at a desired forward speed.

  To cancel the auto cruise state, turn off the switch. Then, the forward shift pedal 27F returns to its original state, and the operation of the hydraulic continuously variable transmission 20 is stopped as described above.

  In the above-described example, the forward transmission pedal (forward operation means) 27F and the reverse transmission pedal (reverse operation means) 27B provided to protrude from the driver's seat floor 22 are connected to the trunnion arm TA via the link mechanism, and are hydraulically operated. Although the continuously variable transmission 20 is mechanically operated, the present invention is not limited to this. For example, two operation levers (forward operation means and reverse operation means) are arranged around the driver's seat 25, and the two operation levers are connected to the trunnion arm TA via a link mechanism to provide a hydraulic continuously variable transmission. 20 may be mechanically operated. Further, a potentiometer may be attached to the rotation fulcrum of the two operation levers, the rotation angle may be detected and sent to the control unit, and the trunnion arm TA may be rotated by a motor or the like by an electric signal from the control unit.

  Further, instead of the electromagnet 72, a permanent magnet may be used to attract the stop plate 71. In this case, the permanent magnet is arranged at a predetermined distance from the stop plate 71 and connected to the operation lever. When the forward shift pedal 27F is at a desired position, the permanent magnet is operated by operating the operation lever. It is comprised so that it may adsorb to. At this time, the permanent magnet is fixed to a side surface of the hydraulic continuously variable transmission or the like via a bracket or the like.

  Furthermore, it may replace with wire (transmission part) W1, W2, W3, and may comprise a transmission part using a link bar. Moreover, it is good also as an electric structure instead of a wire, a link bar, etc. In this case, a control unit is provided, and potentiometers and the like are arranged at the rotation fulcrums C1 and C2 of the forward transmission pedal (forward operation means) 27F and the reverse transmission pedal (reverse operation means) 27B, respectively. The amount of rotation of the reverse shift pedal 27B is electrically detected and transmitted to the control unit, and an interlocking switch (switching unit) is disposed near the driver's seat 25 and connected to the control unit. Further, the engine throttle valve valve is opened and closed by a motor, and the motor and the control unit are connected. When the interlock switch is ON, the opening / closing amount of the engine throttle valve valve is controlled by the motor in accordance with the rotation amount of the potentiometer provided at the rotation fulcrums C1 and C2.

  The working vehicle of the present invention is not limited to a tractor, and can be applied to any agricultural machine such as a rice transplanter or a combine.

10 Tractor (work vehicle with hydraulic continuously variable transmission)
11 Body frame 20 Hydraulic continuously variable transmission 27F Forward shift pedal (forward operation means)
27B Reverse shift pedal (reverse operation means)
31 Interlocking lever (switching part)
54 Oscillating plate (shifting operation part)
71 Stop plate (Suction part)
72 Electromagnet (Magnet)
TA trunnion arm W1, W2, W3 wire (transmission part)

Claims (4)

Forward operating means;
Reverse operation means;
A speed change operation unit interlocked with the forward operation means and the reverse operation means;
In a working vehicle having a hydraulic continuously variable transmission including a trunnion arm interlocked with the speed change operation unit,
A metal attracted part attached to the lower part of the forward operation means;
An auto cruise mechanism is configured with a magnet arranged at a certain distance from the attracted portion and attached to the body frame,
When the forward operation means is operated to achieve a desired traveling speed, the forward operation means is held at a desired operation position by attracting the magnet to the attracted portion. Work vehicle having a continuously variable transmission. The magnet is an electromagnet, and includes a switch for turning ON / OFF the magnetic force of the electromagnet;
When the forward operation means is operated to achieve a desired traveling speed, the switch is turned on to generate a magnetic force in the electromagnet, and the electromagnet is attracted to the attracted portion to thereby change the forward operation means. The working vehicle having the hydraulic continuously variable transmission according to claim 1, wherein the working vehicle is held at a desired operation position. A set of transmission portions respectively interlocking with the forward operation means and the reverse operation means;
A working vehicle having a hydraulic continuously variable transmission that opens and closes an engine throttle valve by operating the transmission unit,
The transmission unit includes a switching unit,
2. The working vehicle having a hydraulic continuously variable transmission according to claim 1, wherein the switching unit selects whether or not to transmit the operation of the transmission unit to the engine throttle valve.   The working vehicle having a hydraulic continuously variable transmission according to claim 3, wherein the transmission portion is made of a wire.

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