JPS6225926Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is configured to transmit power from an engine to a traveling device via a continuously variable transmission, and includes a speed change operation mechanism for the transmission, This invention relates to agricultural workers using tractors, combine harvesters, etc. equipped with foot pedals for increasing and decreasing speed by stepping in forward and reverse directions.

[Conventional technology]

In addition to running at an arbitrary speed by changing the speed of the foot pedal, it is preferable for the above-mentioned agricultural vehicle to run at a constant speed in order to stabilize the work and simplify the operation.For this reason, conventionally, for example, Jitsukai 1976
- As shown in Publication No. 16539, when the speed is changed to a predetermined speed using the foot pedal, in that state, the lever connected to the pedal is engaged with the engaging part formed on the fixed part of the aircraft body. It was used as a stopper to lock the movement of the lever, making it impossible to shift gears using the foot pedal. However, with this structure, when there is a risk of collision with another object at the edge of a ridge, etc., even if the pedal is depressed to the deceleration side, the deceleration operation is blocked by the stopper, and the action of the stopper must be manually released. It was difficult to stop the vehicle unless it was stopped, and it was difficult to stop suddenly, resulting in a lack of safety.

In addition, the structure that does not limit the speed setting by the foot pedal to a constant speed only, but allows the speed to be increased or decreased to a certain extent within a predetermined range, is
As shown in Publication No. 59427, the upper and lower limits of the speed change range of the foot pedal are defined, and even though the speed cannot be increased by pressing the pedal,
Techniques have also been known in which when the pedal is released, the neutral return biasing force of the transmission automatically returns to the set speed. However, even with such a structure, the speed of the aircraft when the foot pedal is free is limited to the lower limit range.
The danger of not being able to stop suddenly without manually releasing it remained unresolved.

[Means for Solving the Problems] In view of the above points, the present invention is capable of automatically maintaining running at any speed change state and constant speed work, while also preventing sudden stopping operations. The purpose is to make it easy and quick to improve safety.

[Means for solving problems]

The characteristic configuration of the present invention for achieving the above object is configured to transmit power from an engine to a traveling device via a continuously variable transmission, and to transmit power from the engine in forward and reverse directions. In an agricultural vehicle equipped with a speed change operation mechanism with a foot pedal for increasing speed by foot operation, the speed change operation mechanism includes a speed setting mechanism for maintaining an arbitrary speed change operation position of the continuously variable transmission. a frictional resistance member for linking the speed setting mechanism with the frictional resistance member for applying frictional resistance to the operation of the speed change operation mechanism in the direction in which the continuously variable transmission is changed;
It is composed of an elastic biasing device for elastic pressing and biasing, which prevents the speed change operation by friction when pressed by the frictional resistance member, and a biasing force changing device for changing the strength of the biasing force of the elastic biasing device. This structure has the following functions and effects.

[Effect]

In other words, the traveling speed of the aircraft, which is changed by the foot pedal, is not set by a rigid mechanical locking means that cannot be decelerated unless the lock is released, as in the past.
Since the speed is set using a friction locking device that can be forcibly operated by applying a certain amount of force, the friction locking ensures that the desired gear shifting operation is maintained, but in the event of a sudden stop, the pedal will not be activated. By forced operation, the transmission can be operated to reduce the set speed against the frictional force of the speed setting mechanism.

In addition, if the frictional resistance is too large to be fixed by friction, it will be difficult to shift using the foot pedal.
On the other hand, if it is too small, it will be difficult to securely fix it at a constant speed and it will be difficult to put it into practical use. However, the speed setting mechanism is equipped with a biasing force changing mechanism to change the degree of frictional resistance. , it is possible to change the friction force in the speed setting mechanism as needed.

[Effect of idea]

Therefore, for work that requires arbitrary speed changes by operating the foot pedal, the frictional force of the speed setting mechanism is weakened to compensate for the light speed change operation, and when the work requires traveling at a constant speed, the frictional force is strengthened. Stable and constant speed work can be performed.

Moreover, even though such a device can perform stable and low-speed work, it is not completely mechanically locked, but is fixed by the strength of friction, so in an emergency, if a strong force above a certain level is applied, the friction can be reduced. It is also possible to perform a forced operation against the rigid body stopper, and the aircraft can be stopped suddenly without the need to release the rigid stopper, which is excellent in terms of safety.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on illustrative drawings.

A traveling device 3 consisting of a pair of front and rear wheels 1 and 2.
An engine 4 is mounted on the front part of a running vehicle body equipped with an engine 4, and a driver's seat 5 and a steering wheel 6 are provided on the rear side, and the power from the engine 4 is transmitted to the rear transmission case via a hydraulic continuously variable transmission 7. 8, and from the rear transmission case 8 to the traveling device 3, the front and rear wheels 1,
Agricultural tractors are configured to be able to carry out various tasks by attaching a lawn mowing device to the lower abdomen of the vehicle body between the two, or by attaching a rotary tiller device to the rear of the vehicle body.

A first bracket 10 is connected to the speed change operation shaft 9 of the hydraulic continuously variable transmission 7, and a second bracket 13 is connected to the support shaft 12 to which a foot pedal 11 is rotatably attached. The bracket 10 and the second bracket 13 are connected via a link 14, and a damper 15 for buffering is interlocked with the second bracket 13, so that the gear can be shifted forward and backward by depressing the pedal 11 while preventing sudden gear change operations. It is configured so that the gear can be changed in either direction.

A cam surface F is formed at the lower end of the first bracket 10, and a cam body 17 that is brought into contact with the cam surface F is connected to an arm 16 that is swingably provided around the horizontal axis P, and A spring 18 is attached to the arm 16 in order to urge the cam body 17 to swing toward the side where it comes into contact with the cam surface F, and the transmission 7 is placed in a neutral operating state when the pedal 11 is not operated. The structure is such that the energization is restored.

a gearshift operating shaft 9, a first bracket 10, which is linked to the gearbox 7 and operates to shift the gear;
The link 14, the second bracket 13, the support shaft 12, and the pedal 11 are collectively referred to as a speed change operation mechanism.

A bracket 19 provided near the handle 6
A support shaft 20 having an oval-shaped portion with a different diameter is mounted on the
The bracket 19 is located on one end side of the support shaft 20.
A fixed cam 21 is attached so as to be slidable only, and a rotary cam 22 that acts on the fixed cam 21 is attached so as to be slidable and rotatable, and on the other hand, a friction plate 23 is attached to the other end of the support shaft 20 so as to be slidable. A pair of disk plates 24, 24 are slidably and rotatably attached to the disc plates 24, 24, which are held in pressure contact with each other, and a coil spring 25 is interposed between the friction plate 23 on one end side and the rotating cam 22, Then, one end of the link 26 is locked and connected across the protruding portions of both the disk plates 24, 24, and the other end of the link 26 is connected to the second bracket 13, and the rotary cam 22 is connected to the second bracket 13. The operating lever 22a is connected, and each of these elements, that is, the fixed cam 21 and the rotary cam 22 constitute a biasing force changing device 27, and the coil spring 25 constitutes an elastic biasing device. , the friction plate 23 and the disc plate 2
4 constitutes a friction resistance member, and each of these components constitutes a speed setting mechanism 28.

With the above configuration, the pedal 11
A suitable running speed is obtained by operating the lever 22a, and in this state, the rotating cam 22 is operated by the lever 22a, and the disc plates 24, 24 are frictionally fixed by the biasing force of the coil spring 25, whereby the running speed of the transmission 7 is increased. The speed can be maintained at a desired speed, and even in the frictionally fixed state, depressing the pedal 11 rotates the disc plates 24 against the frictional force, and the transmission 7
It is also possible to perform sudden stop welding by changing the speed.
The speed setting mechanism 28 can also be used when moving backward at a constant speed.

The present invention is not limited to the above-mentioned agricultural tractors, but can be applied to various agricultural vehicles, such as combine harvesters equipped with crawler traveling devices as the traveling devices 3.

Note that although reference numerals are written in the claims section of the utility model registration for convenience of comparison with the drawings, the present invention is not limited to the structure of the attached drawings by such entry.

[Brief explanation of the drawing]

The drawings show an embodiment of the agricultural vehicle according to the present invention,
Figure 1 is an overall side view of the agricultural tractor, Figure 2 is an enlarged partially cutaway view of the main parts, Figure 3 is an exploded perspective view of the speed setting mechanism, and Figure 4 is a partially cutaway front view of the speed setting mechanism. be. 3... Travel device, 4... Engine, 7... Continuously variable transmission, 11... Foot pedal, 23, 24...
...Frictional resistance member, 25...Elastic biasing device, 27...
Biasing force changing tool, 28...speed setting mechanism.

Claims (1)

[Scope of utility model registration request] It is configured to transmit power from the engine 4 to the traveling device 3 via a continuously variable transmission 7, and a foot pedal is used to increase and shift the speed of the continuously variable transmission 7 by stepping in forward and reverse directions. pedal 11
The agricultural vehicle is equipped with a speed change operation mechanism, and the speed change operation mechanism includes a speed setting mechanism 28 for maintaining an arbitrary speed change operation position of the continuously variable transmission 7.
and its speed setting mechanism 28
Frictional resistance members 23 and 24 provide frictional resistance to the operation of the gearshift operation mechanism in the direction in which the continuously variable transmission 7 is operated for gearshift operation, and the gearshift operation is performed by pressure contact between the frictional resistance members 23 and 24. Agricultural work characterized by comprising an elastic biasing tool 25 for elastic pressing and biasing to prevent the above-mentioned elastic biasing tool 25 by friction, and a biasing force changing tool 27 for changing the strength of the biasing force by the elastic biasing tool 25. car.