JP2001171385A - Travel/shift control device for working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a travel/shift control device for a working vehicle that can ensure travel motion with stepped shifts and travel motion with continuous shifts. SOLUTION: An interlock mechanism 20 interlocks a shift lever 13 with a control portion 10a of a continuously variable transmission for travel motion generation. For an operation of the shift lever 13 in a forward low-speed control range FL and in a reverse low-speed control range RL, friction type position retaining means 50 retain the shift lever 13 in a step-less control position to thereby retain the continuously variable transmission in a continuously controlled speed phase. For an operation of the shift lever 13 in a forward high-speed control range FH and in a reverse high-speed control range RH, lock type position retaining means 30 retain the shift lever 13 in a stepped control position to thereby retain the continuously variable transmission in a step-controlled speed phase.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling shift operation device for a working vehicle provided with a shift lever for shifting a continuously variable transmission that transmits power to a traveling device.

[0002]

2. Description of the Related Art Conventionally, as described in Japanese Patent Application Laid-Open No. 5-58183, a switching lever interlocked with an operation section of a continuously variable transmission is provided with a vertically long hole in a horizontally long guide plate and a vertically long hole. There has been a device that holds the operating position by a position holding mechanism including a spring ball that is detachable from a hole. That is, when the switching lever is rocked, the stepped operation position is held by the engagement between the elongated hole and the spring ball, and the continuously variable transmission is held in the stepped shift state.

[0003]

For example, when working by connecting a tilling device with an agricultural tractor or when traveling on a headland or on a road, the vehicle runs at high speed, and when working by connecting a trencher or the like, Driven at low speed. In the case of high-speed running, even if the running speed slightly changes, the work and running are not easily affected.On the other hand, in the case of low-speed running, if the running speed is slightly increased from an appropriate speed, the work load increases significantly and the finish is finished. Changes in running speed, such as worsening or harder to drive, can greatly affect work and running. Further, in the above-described conventional transmission technology, the continuously variable transmission is maintained at a stepped speed state even when the switching lever as the transmission lever is operated in any part of the lever operation range.
For this reason, conventionally, when performing low-speed traveling, the continuously variable transmission cannot be maintained at an appropriate speed state, or when performing a shift operation, the speed state of the continuously variable transmission is excessively changed, and the work finish is deteriorated. In some cases, it became difficult to drive. SUMMARY OF THE INVENTION An object of the present invention is to provide a traveling speed change operation device for a work vehicle that can easily perform a speed change operation and speed adjustment even when traveling with the continuously variable transmission set to any of high and low speeds.

[0004]

The constitution, operation and effect of the invention according to claim 1 are as follows.

[Constitution] In a traveling speed change operation device for a working vehicle provided with a speed change lever for shifting the speed of a continuously variable transmission that transmits power to the travel device, there is no stepless speed change device in the operation range of the speed change lever. There is a stepless speed change range that is held in a stepped speed change state, and a stepped speed change range in which the stepless transmission is held in a stepped speed change state.

[Operation] When the shift lever is operated in the stepless speed change range, the continuously variable transmission is held in the stepless speed change state, and the traveling device can be shifted steplessly. In addition, the continuously variable transmission is held in the stepped shifting state, and the traveling device can be shifted in the stepped manner. Thus, for example, by setting the stepless speed change range in which the continuously variable transmission shifts in a high speed range and setting the stepless speed change range in which the continuously variable transmission shifts in a low speed range, when traveling at high speed, When re-running, for example, after interrupting, it is possible to easily shift the traveling device to the speed state before the interruption by operating while easily judging whether or not the shift lever has been operated to the operating position that was operated before the interruption,
When traveling at low speed, set the continuously variable transmission to an appropriate speed state, finely adjust the set speed state of the continuously variable transmission to set the traveling speed appropriate for work, or fine-tune become able to.

[Effect] Therefore, it is possible to easily reset the running speed to one corresponding to work or running, or to finely adjust the running speed to easily obtain or maintain a desired speed.

The structure, operation and effect of the invention according to claim 2 are as follows.

In the configuration according to the first aspect of the present invention, the continuously variable transmission region is where the continuously variable transmission shifts in a low speed region of the continuously variable transmission, and the stepless transmission region is where the continuously variable transmission includes the continuously variable transmission. The speed is changed in the high speed range.

[Operation] When the shift lever is operated in the continuously variable shift range, the continuously variable transmission is maintained in a continuously variable shift state in the low speed range, and the traveling speed can be continuously changed on the low speed side. When operated in the stepped speed range, the continuously variable transmission is held in the stepped speed change state in the high speed range, and the traveling speed can be shifted stepwise on the high speed side.

[Effect] Therefore, when traveling at high speed,
When re-running after interrupting work, etc., the shift lever can be easily shifted to the speed state before interruption by operating the shift lever while easily judging whether or not it was at the operating position that was operated before interruption You can easily change gears. When traveling at low speed, the continuously variable transmission is set to an appropriate speed state, or the set speed state of the continuously variable transmission is finely adjusted, and the traveling speed is set to an appropriate speed state or finely adjusted to achieve a good finish. Can work.

The structure, operation and effect of the invention according to claim 3 are as follows.

[Structure] In the structure of the invention according to claim 1 or 2, the continuously variable transmission is a hydrostatic continuously variable transmission.

[Operation] In the case of a hydrostatic type continuously variable transmission, it is driven with oil leakage.
The speed is lower when traveling at low speed than when traveling at high speed.
In addition, as the traveling load increases, the amount of leak increases, and when the traveling load is large, the vehicle travels at a low speed. For this reason, in the case of low-speed traveling, speed changes are likely to occur.However, the speed of the continuously variable transmission is maintained steplessly, and the traveling speed is finely adjusted so as to be an appropriate speed according to the work. it can.

[Effect] While employing a hydrostatic continuously variable transmission as a continuously variable transmission so as to facilitate shifting both on the forward side and on the reverse side, and at the time of high-speed running, the transmission lever is used. When working while traveling at a low speed, the traveling speed is set to an appropriate one according to the work, while the traveling can be reliably held at the predetermined operation position by the locking type position holding means against the strong restoring force that acts. You can run while adjusting and adjusting to get a good finish.

The structure, operation and effect of the invention according to claim 4 are as follows.

[Structure] In the structure according to the third aspect of the present invention, the continuously variable transmission range is such that the continuously variable transmission shifts in a low speed range on both the forward and backward sides of the continuously variable transmission.
The continuously variable transmission changes the speed in both forward and backward shift ranges.

[Operation] Regardless of whether the vehicle is traveling forward or backward, when the shift lever is operated in the continuously variable speed range, the continuously variable transmission is held in a continuously variable shift state, and the continuously variable transmission can be performed. When the lever is operated in the stepped speed change range, the continuously variable transmission is held in the stepped speed change state and the traveling speed can be shifted stepwise.

[Effects] Therefore, regardless of whether the vehicle is traveling forward or backward, the traveling speed can be easily reset to a speed suitable for work or traveling, or a desired speed can be easily obtained or maintained by fine adjustment. You can run.

The structure, operation and effect of the invention according to claim 5 are as follows.

[Structure] In the structure of the invention according to any one of claims 1 to 4, the speed change lever is interlocked with an operation portion of a continuously variable transmission, and the speed change lever is operated in a stepped manner in the stepped speed change range. Position holding means for holding a position in a position, and position holding means for holding a position of a shift lever in a stepless operation position in the stepless speed change range.

[Operation] The shift lever is operated, and the operating force is transmitted to the operation section of the continuously variable transmission to operate the continuously variable transmission. When the shift lever is operated in the stepped shift range,
When the shift lever is held in the stepped operation position by the position holding means, the continuously variable transmission can be held at the stepped speed state. When the shift lever is operated in the continuously variable shift range, the shift lever is moved to the position holding means. As a result, the continuously variable transmission can be held at a continuously variable speed state by being held at a continuously variable operation position. The stepless transmission can be held in a stepped or stepless speed state while shifting with an operating force applied to a shift lever.

[Effect] The structure in which the continuously variable transmission is shifted by the operating force applied to the shift lever is economically advantageous so that it can be operated by a simple operation mechanism, and that the stepped and continuously variable transmission can be performed depending on the speed state. Is obtained.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a pair of left and right steering wheels 1 and 1, which can be driven and driven, a pair of left and right driven rear wheels 2, 2, an engine 3 and a radiator for cooling the engine. A transmission portion provided with a steering unit 5 provided with a steering wheel 5 and a driver's seat 6 provided at the rear of the transmission portion 7 and the like; A lift arm 8 for connecting various working devices such as a rotary tilling device so as to be able to move up and down freely, and a power take-out shaft 9 for transmitting turning power from the engine 3 to the connected working device are used for agricultural use as an example of a working vehicle. Make up the tractor.

A continuously variable transmission 10 for traveling is mounted at the front of the transmission case 7. The continuously variable transmission 10 includes a plunger-type variable discharge pump for inputting the rotational output of the engine 3 through a clutch 11 and a rotary transmission shaft 12, and a hydraulic motor driven by hydraulic oil from the pump. It is configured as a hydraulic stepless transmission. The hydraulic motor transmits the rotation output to an input portion of a gear type traveling mission provided inside the transmission case 7. As a result, the continuously variable transmission 10
The rotational power from the engine 3 is used as forward or reverse rotational power, and is continuously variable on both the forward and reverse sides to be transmitted to the front and rear wheels 1 and 2 via the traveling transmission. Or stop power transmission.

That is, the speed of the continuously variable transmission 10 is shifted by the traveling speed change operation device provided with the speed change lever 13 located on the side of the driver's seat 6, thereby switching the tractor between forward and backward movements, stopping the traveling operation, and moving forward. The traveling speed change is performed on the side and the reverse side.

As shown in FIG. 2, the traveling speed change operation device comprises:
The shift lever 13 and the rear wheel fender 1 that are interlocked with the operation unit 10a of the continuously variable transmission 10 by the interlocking mechanism 20.
4 is provided with a guide groove 15 provided to guide the operation of the speed change lever 13, a locking type position holding means 30 acting on the speed change lever 13 to hold the position thereof, and a friction type position holding means 50. The details are configured as follows.

That is, as shown in FIGS.
The speed change lever 13 includes a base end lever portion 13b formed of a band plate member having a base end portion 13a rotatably connected to a support shaft 16 supported by a lateral side wall portion of the transmission case 7,
An intermediate lever portion 13c made of a round bar having a proximal end portion fixed to the distal end portion of the proximal end lever portion 13b, and a proximal end portion 13d rotatable by a connecting pin 17 at the distal end portion of the intermediate lever portion 13c. And a lever portion 13e made of a round bar material and connected to each other,
A grip portion 13f formed by attaching a resin grip member to the tip side of the tip lever portion 13e, and the tip lever portion 13e is laterally outwardly of the vehicle body with respect to the intermediate lever portion 13c around the axis of the connecting pin 17. And a spring 18 that oscillates to the side that oscillates.
By 3f, the swinging operation is performed in the longitudinal direction of the vehicle along the guide groove 15 as shown in FIGS.

As shown in FIGS. 2, 3 and 4, etc., the operating portion 10a of the continuously variable transmission 10
Rotary operating shaft 10b for changing the swash plate angle of the hydraulic pump
Is formed by a plate-like member whose corner is integrally rotatably connected to the square shaft. Thereby, the operation unit 10a
The swash plate angle of the hydraulic pump is changed by rotating the rotary operation shaft 10b by performing a swing operation around the axis of the rotary operation shaft 10b.

The interlocking mechanism 20 has a connecting shaft 21 having one end connected to the operating portion 10a and the other end protruding outside of the vehicle body from a through hole 19a of a center frame 19 forming an intermediate portion of the vehicle body. A swing link whose base end is rotatably connected to a support shaft 22 supported on the outer surface of the lateral side wall of the center frame 19, and whose intermediate portion is connected to the connection shaft 21 via a buffer rubber 23. 24 and one end thereof is rotatably connected to the free end of the swing link 24, and the other end is rotatably connected to the intermediate portion of the base lever 13 b of the speed change lever 13. It is constituted by an interlocking rod 25 that connects the oscillating link 24 and the speed change lever 13 to oscillate in conjunction with each other. That is,
When the shift lever 13 is rocked, the operation force is applied to the interlocking rod 25, the rocking link 24, the cushion rubber 23, the connecting shaft 21.
To the operating unit 10a through the control unit 10 and swings the operating unit 10a around the axis of the rotary operation shaft 10b. At this time,
The cushion rubber 23 absorbs the vibration of the operation unit 10a and makes it difficult to transmit the vibration to the shift lever 13.

Thus, when the shift lever 13 is swung in the front-rear direction of the vehicle body in the operation area A formed by the guide groove 15, the operation portion 10a is rotated about the axis of the rotary operation shaft 10b by the operation force. Rocks. When the shift lever 13 is operated to a neutral position N located at an intermediate portion in the front-rear direction of the operation area A, the operation portion 10a is set to the neutral position, and the swash plate angle of the motor is set to a neutral angle. Shift lever 1
When the operator moves the motor 3 to the forward operation area F located on the vehicle body front side of the neutral position N in the operation area A, the operation section 10a moves to the forward position and sets the swash plate angle of the motor to the forward angle. At this time, as the shift lever 13 is moved forward of the forward operation area F, the swing stroke of the operating portion 10a toward the forward side increases, and the operating angle of the swash plate toward the forward side increases. Go. When the shift lever 13 is operated to a reverse operation area R located on the vehicle rear side of the neutral position N in the operation area A, the operation unit 10a is in the reverse position and the swash plate angle of the motor is set to the reverse angle. I do. At this time, as the shift lever 13 is moved to the rear side of the reverse operation range R, the swing stroke of the operating portion 10a toward the reverse side increases, and the operating angle toward the reverse side of the swash plate increases. Go.

As shown in FIGS. 2 and 5, the locking type position holding means 30 is a plate body having one end rotatably connected to a bracket 31 supported by the transmission case 7 by a connecting pin 32. The transmission lever 13 is a shaft center of the connecting pin 32 in the lateral direction of the vehicle body.
A positioning member 33 supported on the vehicle body so as to be swingable about an axis 32a parallel to the oscillation axis 16a, and a locking member 34 formed of a roller attached to the base lever portion 13b of the speed change lever 13. And this locking body 34 is
3 is provided with a locking spring 37 which is urged to slide into the positioning recesses 35 and 36.

The positioning member 33 includes a long hole 38 for the locking body into which the locking body 34 is movably inserted, and a long hole 38 for the locking body above the front end portion of the long hole 38 for the locking body. And a plurality of positioning recesses 35 arranged in the direction of movement of the speed change lever 13 and a locking body long hole 38 above the rear end portion of the locking body long hole 38. And a plurality of the positioning recesses 36 arranged in the moving direction of the speed change lever 13.

As shown in FIG. 5, FIG.
One end of the support pin 39 for supporting the base lever portion 13b
The guide pin 40 is slidably inserted into the guide slot 40, and the mounting pin 42 connected to the upper end of the support 41 supporting the other end of the support pin 39 at the lower end is provided at the base end lever portion 13b.
Slidably fits in the guide notch 43. The locking spring 37 is provided on the spring receiving portion 13 of the proximal lever portion 13b.
g and the upper end of the support 41, and the support 41 is connected to the guide slot 40 and the guide notch 4.
3, and slidably biases the side away from the positioning member 33. As a result, the locking body 34 is
5 and 36 are supported by the speed change lever 13 in a slidable manner in the direction in which the positioning recesses 35 and 36 are engaged.
It is slidably urged by a locking spring 37 so as to be inserted.

Therefore, when the locking body 34 corresponds to any of the plurality of positioning recesses 35 and 36 by operating the transmission lever 13, the locking body 34 is moved to the positioning recesses 35 and 3.
6 and is locked and supported by the positioning member 33 for this entry, and holds the shift lever 13 in its operating position so as not to return to the neutral position N. That is, the continuously variable transmission 10 has a self-restoring force that naturally returns to the neutral state. As shown in FIG. 3, a positioning link 61 swingably supported by the case of the continuously variable transmission 10, a positioning spring 62 for biasing the positioning link 61 to swing, and the operating portion 10 a are provided. And a cam surface 63 provided on the operation portion 10a by pressing a roller 64 provided on the positioning link 61 against the cam surface 63 of the operation portion 10a by a positioning spring 62.
A positioning mechanism 60 for positioning a at the neutral position acts on the operation unit 10a. This positioning mechanism 60;
Shift lever 1 for self-restoring force of continuously variable transmission 10
3 has a restoring force for self-returning to the neutral position N, but the locking of the locking body 34 and the positioning member 33 by the engagement of the locking body 34 into the positioning recesses 35 and 36 is performed by the shift lever 1.
3 is held in the operating position against its restoring force. When the locking body 34 is in the positioning recesses 35 and 36, an operating force equal to or more than a set force determined by the locking force between the locking body 34 and the positioning member 33 and the frictional force by the friction type position holding means 50 is applied. When applied to the shift lever 13, the locking body 34 is disengaged from the positioning recesses 35, 36 by the operating force and the cam action of the inclined inner surfaces on the front and rear sides of the positioning recesses 35, 36, and the shift lever 13 can be operated. become.

Between the positioning recesses 35 on the forward side and between the positioning recesses 36 on the reverse side, it is difficult to position the locking body 34 due to the mountain shape and space of the positioning member 33 in that portion. By not locking the body 34 to the positioning member 33, and further increasing the restoring force to the neutral state as the continuously variable transmission 10 moves to a higher speed side, the shift lever 13 moves the locking body 34 It is difficult to hold at the operation position located between the concave portions 35 and 36.

As a result, the locking type position holding means 30
The shift lever 13 operated between the low speed range portion FL near the neutral position N of the forward operation range F and the low speed range portion RL near the neutral position N of the reverse operation range R has no positioning action, and Positioning is performed on the shift lever 13 operated on the high-speed range portion FH other than the low-speed range portion FL and the high-speed range portion RH other than the low-speed range portion RL of the reverse operation range R. In performing this positioning operation, the locking type position holding means 30 is provided with the gearshift lever 13 having the positioning recesses 35 and 36.
When the shift lever 13 is located at the operation position corresponding to the operation position, the shift lever 13 is held at the operation position so as not to return to the neutral position N. However, at the operation position between the positioning recesses 35 and 36, the position of the shift lever 13 is not held. Therefore, the locking type position holding means 30 includes a high speed range portion FH of the forward operation range F,
The high-speed range portion RH of the reverse operation range R is formed as a stepless speed change range in which the shift lever 13 is held at the stepped operation position and the continuously variable transmission 10 is held at the stepped speed state.

As shown in FIGS. 5 and 6, the friction type position holding means 50 includes the positioning member 33, a friction member 51 located on both sides of the positioning member 33, and one side surface of the positioning member 33. And a friction spring 52 located on the side.

The friction member 51 and the friction spring 52 are connected to the base lever portion 13b of the transmission lever 13 in a state where the support shaft hole 53, which is long in the direction of movement of the transmission lever 13 provided in the positioning member 33, is movably inserted. Is supported by a support shaft 54 attached to the shaft. The friction spring 52 presses and urges the two friction members 51 against the positioning member 33 such that the pair of friction members 51 sandwich the positioning member 33. As a result, the friction members 51 are moved together with the shift lever 13 along the shaft hole 53 while being pressed against the positioning member 33.
When the shift lever 13 is operated to any operation position in the operation area A, the positioning member 33
Frictional resistance is given to the shift lever 13 by the friction with

Thus, the friction type position holding means 50 is
The shift lever 13 which is operated in the low speed region portion FL of the forward operation region F and the low speed region portion RL of the reverse operation region R and whose position is not held by the locking type position holding means 30,
The continuously variable transmission is held by maintaining the position of the low-speed range portions FL and RL so as not to return to the neutral position N due to friction between the friction member 51 and the positioning member 33, and holding the transmission lever 13 at the stepless operation position. 10 is formed in a continuously variable speed range in which a stepless speed state is maintained.

When the shift lever 13 is operated to the high-speed region portion FH of the forward operation region F and the high-speed region portion RH of the reverse operation region R and the position is held by the locking Even if rattling occurs between the body 34 and the positioning member 33, the friction type position holding means 30 is provided so that the swinging motion and vibration of the speed change lever 13 due to the backlash are less likely to occur.
Acts on the shift lever 13 by friction between the friction member 51 and the positioning member 33.

That is, when the shift lever 13 is operated to swing in the longitudinal direction of the vehicle along the guide groove 15 and is operated to the neutral position N in the middle of the lever operation area A in the longitudinal direction, the continuously variable transmission 10 is operated. The vehicle enters the neutral state and stops transmitting power to the front and rear wheels 1 and 2. At this time, the tip lever portion 13e of the shift lever 13 enters the notch 15A communicating with the guide groove 15 for the swing operation by the spring 18, and the detection switch 70 attached to the inner surface side of the rear wheel fender 14 is provided. Abuts on the operation piece 70a. Then, the detection switch 70 detects that the continuously variable transmission 10 has been operated to the neutral state, outputs a signal for releasing the starting restraint to the engine starting restraint means, and the engine 3 can be started.

When the shift lever 13 is operated in the forward operation range F, the continuously variable transmission 10 switches to the forward drive state, and transmits forward drive force to the front and rear wheels 1 and 2. At this time, as the shift lever 13 is operated forward, the continuously variable transmission 10 shifts to the speed increasing side. When the shift lever 13 is operated in the reverse operation range R, the continuously variable transmission 10 switches to the reverse drive state, and transmits the reverse drive force to the front and rear wheels 1 and 2. At this time, as the shift lever 13 is operated rearward, the continuously variable transmission 10 shifts to the speed increasing side. In both forward traveling and reverse traveling, when the shift lever 13 is operated in the low speed portions FL and RL to shift the continuously variable transmission 10 in the low speed range, the shift lever 13 is moved by the friction type position holding means 50. , And the continuously variable transmission 10 is held in a stepless speed state to change the drive speed of the front and rear wheels 1 and 2 steplessly. When the shift lever 13 is operated in the high-speed portions FH and RH to shift the continuously variable transmission 10 in the high-speed range, the shift lever 13 is locked.
0, the continuously variable transmission 10 is held at a stepped speed state with a pitch determined by the arrangement of the positioning recesses 35, 36 of the locking type position holding means 30, and the drive speed of the front and rear wheels 1, 2 is maintained. Change to a stage. At this time, the shift lever 13 is moved by the friction type position holding means 50 so that there is no play between the positioning recesses 35 and 36 and the locking body 34.
Is held by

The plurality of positioning recesses 35 and 36 are arranged so as to be arranged in an arc centered on the oscillation axis 16a of the speed change lever 13 when viewed in a direction along the oscillation axis 16a of the speed change lever 13. When the support shaft hole 53 of the member 33 is viewed in a direction along the swing axis 16a of the speed change lever 13, the speed change lever 1
3 is formed in an arc shape centered on the swing shaft core 16a. Accordingly, when the locking body 34 and the support shaft 54 relatively move with respect to the positioning member 33, the relative movement is performed in a state in which the locking member 34 and the support shaft 54 are hardly twisted with the positioning member 33.

As shown in FIG. 5, a positioning concave portion 71 is provided in a portion of the positioning member 33 which is located at a central portion in the longitudinal direction of the locking body long hole 38. That is, when the assembling work is performed, the length of the interlocking rod 25 is adjusted so that the operation portion 10a of the continuously variable transmission 10 is located at the neutral position and the locking body 34 of the transmission lever 13 enters the positioning recess 71. It is adjusted by the screw 25a. Then, an assembled state in which the operation position of the shift lever 13 matches the speed state of the continuously variable transmission 10 corresponding to the operation position is obtained.

[Another Embodiment] FIG. 10 shows a travel operating device according to another embodiment. The operating device includes an uneven portion 72 provided on the positioning member 33 along the shaft hole 53 of the positioning member 33. And the positioning member 3
The concave / convex portion 72 is pressed and urged against the support shaft 54 by oscillatingly urging the positioning member 33 with a spring 73 connected to the free end side of the shaft 3. Accordingly, when performing the speed change operation of the continuously variable transmission 10, the support shaft 54 relatively moves with respect to the positioning member 33 while rubbing against the uneven portion 72, and the rubbing generates a moving sound of the shift lever 13 or rubs. The vibration generated by the shift lever 13
Is transmitted to the hand that operates the gearshift lever 1
The shift operation can be performed while easily recognizing the operation stroke and the operation position of No. 3. In particular, when performing a shifting operation in the operation area portions FL and RL where the positioning recesses 35 and 36 of the locking type position holding means 30 do not have the positioning recesses 35 and 36, the locking body 34 moves quietly, but the uneven portion 72 acts. This makes it easier to perform a gear shift operation.

In the above embodiment, the positioning recesses 35, 3
The positioning recesses 35 and 36 are formed so that the angle formed by the inclined inner surfaces on the front and rear sides of 6 and the depth of the positioning recesses 35 and 36 are the same at any operation position.
As shown in FIG. 9, the angles of the inclined inner surfaces 35a and 36a,
The positioning recesses 35, 36 become steeper or deeper as the depth of the positioning recesses 35, 36 reaches the high-speed side.
May be formed and supported such that the stronger the shifting lever 13 reaches the higher speed side, the stronger the locking force is exerted and the position is firmly held. Further, the positioning recesses 35, 36 are so arranged that the angles of the inclined surfaces on the front and rear sides of the positioning recesses 35, 36 are different.
When the shift lever 13 is moved and the shift operation is performed, the operating resistance generated by the detachment of the locking body 34 from the positioning recesses 35 and 36 causes the operation resistance to move the shift lever 13 to the speed increasing side. Differently from the case where the shift operation is performed to the side, the shift operation may be performed while easily recognizing the shift direction.

The present invention can be applied to a working vehicle provided with a crawler belt instead of the wheels 1 and 2. Therefore,
The wheels 1 and 2 and the crawler belt are collectively referred to as traveling devices 1 and 2.

[Brief description of the drawings]

Fig. 1 Side view of the whole agricultural tractor

FIG. 2 is a side view of the traveling operation device.

FIG. 3 is a side view of an operation unit of the continuously variable transmission.

FIG. 4 is a sectional view of an operation unit of the continuously variable transmission.

FIG. 5 is a side view of the position holding unit.

FIG. 6 is a sectional view of a position holding unit.

FIG. 7 is a cross-sectional view of a front end portion of the shift lever.

FIG. 8 is an explanatory diagram of an operation position.

FIG. 9 is a side view of a positioning recess with another embodiment.

FIG. 10 is a side view of an operation device including another embodiment.

[Explanation of symbols]

 1, traveling device 10 stepless transmission 10a operating section 13 speed change lever 30 position holding means for stepless transmission 50 position holding means for stepped transmission A operation area FH, RH stepped transmission area FL, RL stepless transmission Area

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Kenzo 64 Ishizukita-cho, Sakai-shi, Osaka F-term in Kubota Sakai Works (reference) 3D040 AA14 AA22 AA33 AB04 AC14 AC50 AC66 3J552 MA01 MA10 NA05 PA07 PA18

Claims (5)

[Claims] 1. A traveling speed change operation device for a work vehicle provided with a speed change lever for performing a speed change operation of a continuously variable transmission that transmits power to a traveling device, wherein a continuously variable transmission is provided in an operation range of the speed change lever. A traveling speed change operation device for a work vehicle, comprising: a continuously variable transmission region that is maintained in a continuously variable transmission state; and a stepped transmission region in which a continuously variable transmission is maintained in a continuously variable transmission state. 2. The stepless speed change range in which the continuously variable transmission shifts in a low speed range thereof, and the stepless speed change range in which the continuously variable transmission shifts in a high speed range thereof. Claim
2. The traveling speed change operation device for a work vehicle according to 1. 3. The traveling speed change operation device for a working vehicle according to claim 1, wherein the stepless transmission is a hydrostatic stepless transmission. 4. The continuously variable transmission includes a stepless transmission in which the continuously variable transmission shifts in a low-speed region on both the front and rear sides of the continuously variable transmission. The traveling speed change operation device for a work vehicle according to claim 3, wherein the speed change is performed in a speed change range. 5. A position-change means for a step-variable transmission, wherein the speed-change lever is interlocked with an operation section of a continuously-variable transmission, and serves to maintain a position of the speed-change lever operated in the step-variable shift range; The traveling speed change operation device for a working vehicle according to any one of claims 1 to 4, further comprising a position holding means for continuously variable speed change that operates to hold a position on a speed change lever operated in a step speed change range.