JPH0541935Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a speed change operating device for a work vehicle having a hydraulic continuously variable transmission.

Conventional technology Conventionally, in a four-wheeled work vehicle equipped with a hydraulic continuously variable transmission, a shift pedal connected to the hydraulic continuously variable transmission is provided, and the gears are changed by depressing and rotating the shift pedal. is performing an operation. Furthermore, a friction member is provided that restricts the rotational movement of the speed change pedal when the speed change pedal is rotated to an arbitrary position. The gear shift state is maintained.

Here, the friction member and the shift position fixing lever that operates the friction member are connected via a link mechanism, and the shift position fixing lever has a stop position where the friction member fixes the shift pedal, and a shift position fixing lever that operates the friction member. and a stop position for releasing the fixed state of the speed change pedal. In order to stop the shift position fixing lever at the position where the friction member releases the fixed state of the shift pedal, a dedicated stop member is required, and this stop member is fixed to the chassis of the work vehicle, It extends to a position where it interferes with the position fixing lever.

Problems to be solved by the invention: In order to fix a dedicated stop member to a chassis, etc., in addition to the dedicated stop member, a fixing member for fixing the stop member is also required, which increases the number of parts and makes assembly difficult. It takes a lot of time and effort.

Means to solve the problem In a work vehicle equipped with a hydraulic continuously variable transmission,
A friction member that fixes a speed change pedal connected to a hydraulic continuously variable transmission device at an arbitrary rotation position, and a speed change position fixing lever that moves the friction member between a position where the speed change pedal is fixed and a position where the fixed state is released. The friction member and the shift position fixing lever are connected via a four-bar linkage mechanism in which two links intersect in an X shape. When the gear shift position fixing lever is rotated and the friction member is moved to a predetermined position where the gear shift pedal is released from the fixed state, the friction member comes into contact with the link of the four-bar link mechanism and is in a position to restrict the operation of the four-bar link mechanism. Place the connecting pin of the four-bar linkage mechanism.

Operation When the friction member is moved to a predetermined position to release the fixed state of the gear shift pedal, the connecting pin of the four-bar link mechanism comes into contact with the link of the four-bar link mechanism, regulating the operation of the four-bar link mechanism and shifting the gear. Stop the rotation of the position fixing lever.

Embodiment An embodiment of this invention will be described based on the drawings. First, a four-wheeled work vehicle 1 is provided with a hydraulic continuously variable transmission 2. A boss 4 is fixed to the chassis 3 of the work vehicle 1 so as to pass through the chassis 3 in the left-right direction, and a support shaft 5 is inserted through the inner circumference of the boss 4 so as to be rotatable around the axis. . A connecting fitting 7 having a fan-shaped friction portion 6 is fixed to the inner end of the support shaft 5, and a connecting rod is provided between one end of the connecting fitting 7 and the gear shift lever 8 of the hydraulic continuously variable transmission 2. 9 are connected. In addition, the support shaft 5
A speed change pedal 10 is attached to a spring pin 1 at the outer end of the
1 are integrally connected. Furthermore, a cylindrical body 12 is rotatably fitted around the outer periphery of the boss 4, and a brake pedal 14 connected to a brake device (not shown) via a brake rod 13 is fixed to this cylindrical body 12. ing.

Next, a support shaft 15 located close to the connecting fitting 7 and a support shaft 16 located above the support shaft 15 are arranged in the working vehicle 1 with parallel axes. A cylindrical body 17 is rotatably fitted on the outside of the support shaft 16, and a cylindrical body 18 is similarly rotatably fitted on the support shaft 16. Then, the first link 19 whose one end is fixed to the cylindrical body 17 and the second link 20 whose one end is connected to the cylindrical body 18 are crossed in an X shape, and the other end of the first link 19 and the second link 20 are connected to the cylindrical body 17 at one end. link 20
A four-bar link mechanism 22 in which a third link 21 is rotatably connected to the other end is provided.

Here, a shoe 23, which is a friction member that faces the friction portion 6 of the connection fitting 7 so as to be able to freely approach and separate, is attached to the cylinder 17 via a support member 24. On the other hand, a shift position fixing lever 25 and a spring support part 26 are fixed to the cylinder body 18, and the tip part of the spring support part 26 and the locking part 27 are fixed to the cylinder body 18.
A spring 28 is tensioned between the gear shift position fixing lever 25 and the spring 28, which biases the shift position fixing lever 25 in the direction of rotation operation beyond the fulcrum. Next, the second link 20 and the third link 21 are rotatably connected by a connecting pin 29, and this connecting pin 29
The shift position fixing lever 25 is provided at a position where it comes into contact with a side surface of the first link 19 when the shift position fixing lever 25 is rotated to a predetermined position.

In such a configuration, when the shift pedal 10 is depressed and rotated around the axis of the support shaft 5, the support shaft 5 and the connecting fitting 7 rotate integrally, and are further connected via the connecting rod 9. A speed change lever 8 connected to the metal fitting 7 rotates, and the hydraulic continuously variable transmission 2 changes speed in accordance with the amount of depression of the speed change pedal 10.

Here, when maintaining the speed state after operating the hydraulic continuously variable transmission 2 to a desired speed change state, move the speed change position fixing lever 25 from the state shown in FIG. Rotate in direction A. In the state shown in FIG.
The biasing force acts in the direction of rotating the shift position fixing lever 25 in the direction of arrow A', but as the shift position fixing lever rotates in the direction of arrow A, the spring 2
8 exceeds the fulcrum of the support shaft 16, the biasing force of the spring 28 acts in a direction to rotate the shift position fixing lever 25 in the direction of arrow A. Further, as the shift position fixing lever 25 rotates, the connecting pin 29 rotates in the direction of arrow B, and the connecting pin 30 that rotatably connects the first link 19 and the third link 21 rotates in the direction of arrow C. Rotate to. Therefore, the shoe 23 rotates in the direction of arrow D and comes into pressure contact with the friction part 6, and the coupling fitting 7 and the speed change pedal 10
The rotation of the hydraulic continuously variable transmission device 2 is regulated, and the hydraulic continuously variable transmission device 2 is maintained in the operated shift state (FIG. 2). In the state shown in FIG. 2, the biasing force of the spring 28 acts in a direction to rotate the shift position fixing lever 25 in the direction of arrow A, and even if the shift position fixing lever 25 is released, the shift position remains unchanged. Fixed lever 25
is maintained in the state shown in FIG.

Next, when the shift position fixing lever 25 is rotated in the direction of arrow A' from the state shown in FIG. 2, the connecting pin 29 is rotated in the direction of arrow B', and the connecting pin 30 is rotated in the direction of arrow C'. . Therefore, the shoe 23 rotates in the direction of arrow D' and separates from the friction part 6, and the connecting fitting 7 becomes free and the shift pedal 10
is rotatable, allowing for gear shifting operations. Then, when the shift position fixing lever 25 is rotated to a predetermined position in the direction of arrow A', the connecting pin 29 interferes with the side surface of the first link 19 as shown in FIG. This prevents the shift position fixing lever 25 from rotating any further in the direction of arrow A'. On the other hand, in the state shown in FIG. 1, the biasing force of the spring 28 beyond the fulcrum is acting in the direction of rotating the shift position fixing lever 25 in the direction of arrow A', and when the user releases the shift position fixing lever 25, Shift position fixing lever 25
is maintained in the state shown in FIG. 1, and the speed can be changed freely.

Effects of the invention Since this invention is configured as described above, when the friction member is moved to a predetermined position where the fixed state of the gear change pedal is released, the four-bar link mechanism is operated by the connecting pin of the four-bar link mechanism. The shift position fixing lever can be stopped at the rotation stop position by regulating the shift position fixing lever.Therefore, there is no need to provide a new stopping member to stop the shift position fixing lever at the rotation stop position, and the number of parts can be reduced. This has the effect of reducing the number of assembly steps and reducing the number of assembly steps.

[Brief explanation of the drawing]

The drawing shows one embodiment of this invention.
The figure is a side view showing the non-fixed state of the speed change pedal.
FIG. 3 is a side view showing the fixed state of the speed change pedal, FIG. 3 is a side view showing the arrangement of the speed change pedal, etc., FIG. 4 is a front view thereof, and FIG. 5 is a side view showing the entire working vehicle. 1... Work vehicle, 2... Hydraulic continuously variable transmission, 1
0...Speed pedal, 19, 20...Link, 22
... Four-bar link mechanism, 23 ... Shoe (friction member), 25 ... Speed change position fixing lever, 28 ... Spring, 29 ... Connection pin.

Claims (1)

[Scope of utility model registration request] In a work vehicle that has a rotatable speed change pedal connected to a hydraulic continuously variable transmission and a friction member that fixes the speed change pedal at an arbitrary rotational position, a four-joint system in which two links intersect in an X shape is used. A shift position fixing lever is rotatably connected to the friction member via a link mechanism and moves the friction member between a position where the shift pedal is fixed and a position where the shift pedal is released from the fixed state; A spring is provided that biases the gear shift position fixing lever in a rotation operation direction by passing over a fulcrum, and the gear shift position fixing lever is rotated to move the friction member to a predetermined position to release the fixed state of the gear change pedal. A speed change operation device for a work vehicle, characterized in that a connecting pin of the four-bar link mechanism is arranged at a position where it comes into contact with a side surface of the link and restricts the operation of the four-bar link mechanism.