JPH07323762A - Rapid starting preventing mechanism of continuously variable transmission type traveling vehicle - Google Patents

Abstract

PURPOSE:To fix a transmission pedal at the neutral position in the brake locking to avoid the condition of the rapid starting when the brake locking is released in a continuously variable transmission type traveling vehicle of pedal operation type. CONSTITUTION:In a traveling vehicle having a transmission pedal 1 for the continuously variable transmission, a brake pedal 2, and a brake locking lever 3, a locking pin 1d of an engaging arm 1c for neutral return to be projected from a rotary shaft 1a of the transmission pedal 1 and a locking pin 2d of an engaging arm 2c for the brake locking of the brake pedal 2 are engaged with engaging parts 3c or 3d, and 3e in operating the brake locking lever.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a sudden start preventing mechanism in a traveling vehicle such as a tractor which is continuously variable by depressing a pedal.

[0002]

2. Description of the Related Art Conventionally, a traveling vehicle such as a tractor which has a continuously variable transmission such as an HST transmission and is continuously variable by pedal operation has been known. A configuration is also known in which a brake lock lever for fixing the vehicle in a braked state is provided in order to stop the vehicle regardless of whether the engine is started or a shift operation is performed at the time of starting. However, in the past, when the brake lock lever was applied, the pedal for gear shifting operation was returned to the neutral position,
The simple structure did not provide a quick and reliable fixing in the neutral position.

[0003]

If the pedal for gear shift operation is not securely fixed to the neutral position when the brake is locked, for example, in the case of an HST transmission, the movement of pressure oil in the hydraulic circuit of the device is maintained. If you release the brake lock lever, it will start suddenly, which is very dangerous. Therefore, there is a demand for a configuration that reliably holds the pedal for gear shift operation at the neutral position when the brake is locked.

[0004]

The problems to be solved by the present invention are as described above. Next, the means for solving the problems will be described. In a traveling vehicle having a speed change operation pedal for continuously variable speed change and a brake pedal, a brake lock lever is provided to lock the brake pedal at a brake depression position, and the speed change operation pedal and the brake pedal are connected to the brake lock lever. An engaging portion is provided so as to project, and an engaging portion that engages with the engaging portion is provided on the side of the brake lock lever, and when the brake pedal is in the brake lock state by the turning operation of the brake lock lever, The gear change operation pedal is fixed to the neutral position.

[0005]

[Operation] Next, the operation will be described. Since the rotation of the brake pedal is restrained while the brake is applied by using the brake lock lever, the gear shift operation pedal can be guided to the neutral position by using the engaging portion of the brake lock lever.
Prevents sudden start after releasing the brake lock.

[0006]

EXAMPLES Next, examples will be described. FIG. 1 is an overall side view of a lawn tractor T equipped with a sudden start preventing mechanism of the present invention, FIG. 2 is a plan view of essential parts of a brake lock lever, a brake pedal, and a shift operation pedal, and FIG. FIG. 4 is a side view of the main part when the brake is locked, FIG. 4 is a side view of the main part when the brake is locked when the brake is set for a tall person, and FIG. FIG. 7 is a plan view of the same, FIG. 8 is a rear view of the same, FIG. 9 is a side view of a main part of the constant speed travel device, and FIG. 10 is a rear view of the same part. 4A and 4B are front views showing the shape of a detent hole of the rotating cam 32 in the constant speed traveling device, FIG. 9A being a round hole and FIG. 8B being a long hole.

A lawn mower tractor T having a sudden start preventing mechanism according to the present invention will be described with reference to FIG. On the upper part of the frame F, a bonnet 4 for covering the engine is mounted on the front side, and a dashboard 5 is erected on the rear end of the frame to project a steering wheel 6. A portion 7 is formed by utilizing the upper surface of the frame F, and the right front end portion thereof is
As shown in FIGS. 2 to 7, the gear shift operation pedal 1 and the brake pedal 2 are provided so as to project from below the frame F to above, and the brake lock lever 3 projects from near the center of the lower end of the dashboard 5. It is set up. A seat 8 is disposed behind the step portion 7, and a constant speed lever 9 is provided on the side of the seat 8. A front wheel FW is arranged at the front of the frame F, and a mission case M is arranged at the rear of the frame F, and the rear wheel RW is suspended on the mission case M.

A lawn mower 10 having a lawn mowing blade is hung on the abdomen of the lawn mower tractor T, and a thrower 11 and a sprinkling pipe 12 are arranged from the side of the lawn mower 10. The cut grass is thrown into the catch box 13 mounted on the rear part of the Lonemore tractor T.

Next, the arrangement of the shift operation pedal 1 and the brake pedal 2 and the connecting mechanism of the brake pedal 1 and the shift operation pedal 2 below the frame F will be described with reference to FIGS. 2 to 8. First, the shift operation pedal 1 having an L-shape in side view can be rotated back and forth about the rotation shaft 1a as a rotation fulcrum. As shown in FIGS. A link arm 1b for a gear and an engaging arm 1c for neutral return are provided in a projecting manner. It is pivotally supported in the pivot hole 14a or 14b. As shown in FIGS. 3 and 4, when it is pivotally supported in the pivot hole 14a, the height of the speed change operation pedal 1 is set to a standard height, and as shown in FIG. 5, it is pivotally supported in the pivot hole 14b. At times, the height of the speed change operation pedal 1 becomes low, and it becomes easy for a long person with long legs to operate.

The rear end of the speed change rod 14 has a rotating shaft 15a.
Is pivotally connected to the lower end of the speed change cam plate 15 which is rotatable, and the tip of the speed change arm 16 extended from the trunnion 17 of the transmission case M is attached to the cam portion 15b at the rear end of the speed change cam plate 15. Roller portion 16a is in contact, and the speed change arm 16 is urged by a spring to return to the neutral state. When the front end of the speed change operation pedal 1 is depressed, the speed change rod 16 slides rearward, and the speed change cam plate 1
5 rotates forward, the forward speed is determined by the amount of rotation. On the other hand, when the rear end of the speed change operation pedal 1 is depressed, the speed change rod 14 slides forward and the speed change cam plate 15 moves. Rotates backward, and the reverse speed is determined by the amount of rotation. When the constant speed lever 9 is at the neutral position N1 when the foot is released from the speed change operation pedal 1, the speed change cam plate 15 also moves slightly forward of the constant speed lever 9 when the speed change arm 16 returns to the neutral position. To the neutral position N2, and therefore the transmission rod 1
The gear shift operation pedal 1 also returns to the initial position via the switch 4. The neutral position N1 of the constant speed lever 9 corresponds to a position after the maximum pivot position rearward of the neutral position N2 of the speed change cam plate 15, and therefore does not interfere with the rearward rotation of the speed change cam plate 15. .

Next, in the brake pedal 2, its base rotation shaft 2a is rotatably supported on the frame F in the left and right directions, and a link arm 2b protruding from the base rotation shaft 2a is interposed. 8 to pivotally connect the front end of the brake rod 18, and the rear end of the brake rod 18 is connected via a link mechanism 19 to a brake arm 20 shown in FIG. When the brake pedal 2 is depressed, the brake rod 18 is slid forward, and the transmission case M
The brake is applied inside.

Further, the base rotation shaft 2 of the brake pedal 2
At a, a connecting plate 21 is fixedly attached to a part of the frame F and is biased forward by connecting a spring 22 to the rear end of the connecting plate 21 and a front end of a constant speed releasing rod 23. It is pivotally connected, and the rear end of the constant speed releasing rod 23 is pivotally connected to a rotating cam 32 in the constant speed traveling device described later. When the foot on the brake pedal 2 is released, the brake pedal 2 returns to the initial position due to the forward biasing of the connecting plate 21,
As a result, the brake rod 18 and the constant speed release rod 23 are returned to their initial positions, and the brake is released in the mission case M. Further, the base rotation shaft 2
From a, the engaging arm 1c for neutral return that projects from the inner end of the base rotation shaft 1a of the speed change operation pedal 1 is approximately flush with the front and rear, and the engaging arm 2c for brake lock is forward and upward. It is projected.

Next, the structure of the brake lock lever 3 will be described with reference to FIGS. The brake lock lever 3 is pivotally supported by a lever rotation shaft 3a and is vertically rotatable, and a return spring 24 is connected to a part of the frame F in front of the lower end thereof, as shown in FIG. The lever portion is biased to be horizontal. The lever rotation shaft 3a
The front side has a flat plate shape, and the shift operation pedal 1
The locking pin rotating hole 3 so that the locking pin 1d protruding from the tip of the neutral return engaging arm 1c is fitted and slid
b is perforated, and the locking pin 1 is provided at the front portion of the upper end thereof.
Engaging portions 3c and 3d are cut out so that d engages. On the other hand, at the lower rear end of the brake lock lever 3,
As the locking pin 2d protruding from the tip of the brake lock engaging arm 2c of the brake pedal 2 is engaged,
The engaging portion 3e is cut out.

The brake lock lever 3 having such a structure
At the time of releasing the brake lock with the lever horizontal, as shown in FIG. 3, the locking pin 1d of the speed change operation pedal 1 is
The locking pin 1d is freely inserted into the locking pin rotation hole 3b, and the locking pin 1d can be freely rotated in the locking pin rotation hole 3b when the shift operation pedal 1 is depressed. The gear can be operated. On the other hand, the locking pin 2d of the brake pedal 2 is also disengaged from the engaging portion 3e, the brake pedal 2 is freely rotatable, and the pedal is freely depressed to apply the brake. Further, when the foot is released from the brake pedal 2, the brake pedal 2 returns to the initial position.

When the lever portion is lifted and the rear end portion of the brake lock lever 3 is rotated upward, the engaging pin 2d is fitted in the engaging portion 3e, and the engaging pin 2d is further engaged.
Is lifted, the brake lock engagement arm 2c is lifted, and accordingly, the brake pedal 2 is rotated downward via the base rotation shaft 2a, and is fixed in a braked state. On the other hand, in the speed change operation pedal 1, even when the locking pin 1d is inserted into the locking pin rotation hole 3b while the pedal is depressed, the brake lock lever 3 rotates with the rotation. The locking pin 1d is guided and fitted into the engaging portion 3c or 3d. Note that FIG.
As shown in FIG.
When the standard height pivotally supported by the pivot support hole 14a is set, the locking pin 1d fits into the engaging portion 3c, and the lower end of the speed change link arm 1b is pivoted as shown in FIG. When the height for a tall person pivotally supported by the support hole 14b is set, the locking pin 1d fits into the engaging portion 3d. Thus, the locking pin 1
In the state where d is fitted in the fitting portion 3c or 3d, the shift operation pedal 1 is fixed at the initial position, that is, the neutral position.

To release the brake lock lever 3, when the brake pedal 2 is depressed, the locking pin 2d is released.
Pushes down the engaging portion 3e to rotate the rear end of the brake lock lever 3 downward, and eventually the locking pin 2d is disengaged from the engaging portion 3e, and the brake lock lever 3 returns the return spring 24. By force, the lever returns to the initial position in which the lever is horizontal, and the locking pin 1d is also disengaged from the engaging portion 3c or 3d, so that the shift operation pedal 1 can be freely operated. Since the gear shift operation lever 1 is held in the neutral position, the vehicle does not suddenly start when the brake lock is released.

Next, the constant speed traveling device will be described with reference to FIGS.
First, the description will be made. The constant speed lever 9 is used for the seat 8 as described above.
However, as shown in FIG. 1, since it does not project above the upper surface of the seating portion of the seat 8,
Since it does not hinder getting on and off and the center of gravity is located rearward, when the constant speed lever 9 is rotatable, it naturally returns to the rearward neutral position N1. . Then, the shift cam plate 15 that is rotated forward and is displaced as the shift operation pedal 1 is depressed
Is fixed at the displaced position, and is driven at a constant speed.

As shown in FIG. 6 or 9, the upper end of the speed change cam plate 15 is located in front of the base of the constant speed lever 9, and when the constant speed lever 9 is rotated forward. , The base end portion 9b thereof comes into contact. And FIG.
As shown in FIG. 0, a rotating plate 9a is extended downward from the base end 9b of the constant speed lever 9, and the rotating plate 9a projects from a fixed plate 25 protruding from the frame F. The pressing shaft 28 is externally fitted to the moving shaft 26, and the pressing plate 28 is externally fitted on the rotating shaft 26, and the fixed cam 29 is attached to the rotating shaft 26 in the holding portion 28 a of the pressing plate 28. The fixed cam 29 and the holding portion 28a of the pressing plate 28 are integrally fixed to the rotating shaft 26 by a fixing pin 30, and the rotating plate of the base end portion of the constant speed lever 9 is installed and held. Rotation suppressing member A that abuts 9a
Is formed. Then, the fixed plate 25 and the rotating plate 9a
Friction plates 27, 27 are respectively interposed in the gap between the pressure plate 28 and the rotating plate 9a.

Steel balls 31, 31 forming a detent are fitted to the outer surface of the fixed cam 29, and a rotary cam 32 connected to the constant speed releasing rod 23 via a pin 34 is provided. The fixed cam 29 is externally fitted to the rotary shaft 26 so as to come into contact with the steel balls 31, 31 fitting surface of the fixed cam 29. The rotating cam 32 is provided with detent holes 32a, 32a into which the steel balls 31, 31 of the fixed cam 29 can be fitted, and a nut 26a is screwed on the end of the rotating shaft 26. Then, the nut 26
a on the rotary shaft 26 between the a and the rotary cam 32.
The rotating cam 32 is pressed against the fixed cam 29 by the spring 33, and the steel balls 31, 31 of the fixed cam 29 are normally moved by the pressing force by the spring 33. The fixed cam 29 and the rotating cam 32 are pressed against each other in a state of being fitted into the detent holes 32a of the fixed cam 29, the pressing plate 28, and the urging force of the spring 33. It is transmitted to the friction plate 27, presses and fixes the rotating plate 9a,
The constant speed lever 9 is pressed and fixed.

When the brake pedal 2 is depressed, the constant velocity releasing rod 23 is slid backward and the rotating cam 32 is rotated, whereby the detent holes 32a, 32a are formed.
The steel balls 31, 31 are further disengaged, so that the rotating cam 32
Rides on the steel balls 31, 31 and contracts the spring 33,
Therefore, the pressing force between the rotating plate 9a and the pressing plate 28 via the friction plate 27 is relaxed, and the constant speed lever 9 becomes rotatable. In this state, as described above, the constant speed lever 9 naturally rotates rearward because the center of gravity is rearward, and does not interfere with the neutral position N1, that is, the rotation of the upper end portion of the speed change cam plate 15. When the foot is released from the brake pedal 2, the constant speed releasing rod 23 slides forward, the rotating cam 32 returns to the original position, and the detent holes 32a and 32a are returned.
The steel balls 31, 31 are fitted in a, and the constant speed lever 9 is
It is fixed at the neutral position N1. On the other hand, in the brake pedal 2, the rotating cam 32 is rotated by the pressing force of the spring 33 in addition to the spring 22, and the steel ball 3 is inserted in the detent holes 32a and 32a.
In order to return the rotating cam 32 to the initial state after the engagement of 1.31 and 31 and the constant speed release rod 23 is returned to the initial state, the brake pedal 2 immediately returns to the initial position.

Incidentally, the detent hole 3 in the rotating cam 32.
The 2a and 32a can be formed in a round hole shape as shown in FIG. 11 (a) to simplify the construction. Further, in order to reduce the operation force at the time of starting the rotation, the rotation direction is taken into consideration. , A detent hole 32a 'having a long hole shape as shown in FIG.
-It is also possible to use 32a '.

A constant-speed traveling operation based on the constant-speed traveling device having such a structure will be described. First, when the constant speed lever 9 is in the neutral position N1 and the vehicle travels forward, the gear is shifted in proportion to the stepping amount of the gearshift operation pedal 1. Due to the restoring force of the arm 16 and the speed change cam plate 15 to the neutral state, it is possible to decelerate by the loosened amount. Further, when the foot is released, the vehicle can be completely returned to the neutral state and the traveling can be stopped, and the shift operation pedal 1 is also returned to the initial position.

In forward traveling, when the speed change operation pedal 1 is fixed at a position where the speed change operation pedal 1 is depressed and constant speed travel is performed, the constant speed lever 9 is moved to the friction plates 27, 27. The constant speed lever 9 is rotated forward against the frictional force, and the base end 9b of the constant speed lever 9 is pressed against the upper end of the speed change cam plate 15 which is rotated forward by the depression of the speed change operation pedal 1. Even if the constant speed lever 9 is released, the constant speed lever 9 cannot rotate due to the urging force of the spring 33 and the frictional force of the friction plates 27, 27. Is fixed at the pressed position against the attempt to return to the neutral position N2, and the speed change arm 16 is fixed at that position, and the constant speed traveling state is achieved. If the constant speed lever 9 is rotated rearward against the frictional force of the friction plates 27, 27, unless the speed change operation pedal 1 is depressed.
The speed can be reduced by the amount of rotation, and the upper end of the speed change cam plate 15 can be further rotated rearward to the neutral position N2 to stop traveling and the constant speed can be released.

Next, when the brake pedal 2 is stepped on, the brake is applied, while the constant speed releasing rod 22 slides backward, and as described above, the rotating cam 32 in the constant speed lever mechanism.
Rotates, and the constant speed lever 9 becomes rotatable,
Immediately after returning to the neutral position N1 by its own weight and releasing the foot from the brake pedal 2, the constant speed lever 9 is automatically fixed at the neutral position N1, and even if the shift operation pedal 1 is depressed, the shift cam The rotation of the plate 15 causes the constant speed lever 9
You can't be disturbed by, so if you release your foot, it will immediately return to the initial state.

When the vehicle is traveling in reverse, the speed change cam plate 15 is located behind the neutral position N2 and the constant speed lever 9
Is further rearward of the speed change cam plate 15, and therefore does not interfere with the return of the speed change cam plate 15 to the front neutral position N2. Therefore, when the vehicle is traveling in reverse, if the stepping force of the foot on the speed change operation pedal 1 is relaxed, the speed change cam plate 15 is rotated in the direction of the neutral position N2, and the speed can be reduced. Since it is rare to maintain reverse running for a long time, constant speed operation is almost unnecessary, and this does not cause any problems. It should be noted that if the constant speed lever 9 is rotated slightly forward, the amount of rearward rotation of the shift cam plate 15 is limited, so that it is possible to limit the maximum reverse speed.

As described above, in the constant speed traveling device, since the detent is interposed between the rotation suppressing member A and the rotation cam 32, the detent is disengaged when the brake pedal is stepped on, so that the rotation is prevented. Since the pressure-bonding between the restraining member A and the rotating cam 32 is immediately released, the constant speed lever 9 is immediately rotatable, and immediately returns to the initial position by its own weight. When the foot is released from the brake pedal 2, the detent fitting state is immediately brought about by the spring pressing force, the rotation of the constant speed lever 9 is suppressed, and the brake pedal 2 is reliably returned to the initial position.

[0027]

Since the present invention is constructed as described above, it has the following effects. In other words, by operating the brake lock lever, the brake can be fixed while the brake is applied, and at the same time the speed change operation pedal is quickly and reliably guided and fixed to the neutral position. At the moment when is released, the gear shift operation pedal is in the neutral position, so there is no sudden start, which greatly improves the safety of the continuously variable traveling vehicle. Further, the structure is simple and the number of parts is small, which contributes to cost reduction.

[Brief description of drawings]

FIG. 1 is an overall side view of a lawn tractor T equipped with a sudden start preventing mechanism of the present invention.

FIG. 2 is a plan view of essential parts of a brake lock lever, a brake pedal, and a gear shift operation pedal.

FIG. 3 is a side view of an essential part when the brake lock is released.

FIG. 4 is a side view of the main part when the brake is locked.

FIG. 5 is a side view of an essential part when the brake is locked, which is also set for a tall person.

FIG. 6 is a side view showing a coupling mechanism for connecting a shift operation pedal and a brake pedal to a constant speed traveling device.

FIG. 7 is a plan view of the same.

FIG. 8 is a rear view of the same.

FIG. 9 is a side view of a main part of the constant speed traveling device.

FIG. 10 is a rear view of the main part of the same.

FIG. 11 is a front view showing the shape of a detent hole of the rotating cam 32 in the constant speed traveling device, in which (a) is a round hole,
(B) is a figure of what made a long hole.

[Explanation of symbols]

 F Frame 1 Rotating Shaft 1a Brake Pedal 1b Shift Link Arm 1c Neutral Return Engaging Arm 1d Locking Pin 2 Fixed Cam 2a Base Rotating Shaft 2b Link Arm 2c Brake Lock Engaging Arm 2d Locking Pin 3 Brake Lock Lever 3a Lever rotation shaft 3b Locking pin rotation hole 3c Engagement part 3d Engagement part 3e Engagement part 24 Return spring

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Suematsu 428 Enami, Okayama City Seirei Industrial Co., Ltd. In-house

Claims (1)

[Claims] 1. In a traveling vehicle having a gear shift operation pedal for continuously variable gear shift and a brake pedal, a brake lock lever is provided to lock the brake pedal at a braking depression position, and the gear shift operation pedal and the brake pedal are provided. An engaging portion for engaging the brake lock lever is provided in a protruding manner, and an engaging portion engaging with the engaging portion is provided on the side of the brake lock lever, and the brake pedal is braked by the turning operation of the brake lock lever. A sudden start preventing mechanism for a continuously variable traveling vehicle, characterized in that the shift operation pedal is fixed to a neutral position in a locked state.