JPS608207Y2 - Forward and backward movement device in tractor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transmission device that allows a tractor to be easily operated in forward and backward directions.

Generally, tractors change gears by selectively meshing gears, and therefore, the forward/reverse gear change operation requires the operation of a clutch and a shift lever, and therefore cannot be performed instantaneously.

Therefore, in recent years, a system called a power shift has been proposed in which a clutch is provided for each gear so that forward and backward movement can be performed by operating only a gear shift lever.

However, this device requires a hydraulic system and many clutches, making it complicated and expensive. In addition, it is limited to a constant reverse speed, and the backward speed differs for each forward movement, which reduces work efficiency. was there.

In addition, although it is equipped with a hydraulic transmission, the hydraulic transmission is not only very expensive, but also continuously variable, so
The speed is determined by the amount of lever movement, so it requires considerable skill to instantaneously operate the lever to achieve the desired speed.
It was generally difficult.

Therefore, the present invention includes a planetary gear device interposed between the transmission shafts in the clutch housing, and further includes a first slide pawl that is slidably disposed on the transmission shaft, and a first slide pawl that is adjacent to the slide pawl and that is adjacent to the transmission shaft. A second rotatably and slidably arranged
The gear case supporting the planetary gear of the planetary gear device can be selectively attached to the transmission shaft or the fixed holder by sliding together with the slide claw of the planetary gear, thereby eliminating the above-mentioned drawbacks. The object of the present invention is to provide a forward and backward movement device for a tractor.

Hereinafter, the present invention will be specifically explained based on embodiments shown in the drawings.

As shown in FIG. 1, the tractor 1 has front wheels 2 and rear wheels 3.
The engine 6 is mounted on the front part of the vehicle body 5, and the driver's seat 7 is provided in the rear part.

As shown in FIG. 2, a clutch housing 9 is disposed below the driver's seat 7, and a transmission case 10 is fixed to the rear of the housing 9.

The clutch housing 9 is connected to the main shaft 1 which is a transmission shaft.
1 is rotatably supported, and the shaft 11 is connected at the front part to a flywheel 12 of the engine and a clutch 13 that can be engaged and disconnected, and at the rear part is connected to a forward and backward movement device 15 according to the present invention. .

Furthermore, a first transmission gear shaft 16, which is also a transmission shaft, extends from the forward/reverse device 15 toward the transmission case 10 in alignment with the main shaft 11.
is interlocked with the traveling axle via a gear train 17 within the case 10.

As shown in FIG. 3, the forward and backward movement device 15 is rotatably supported by a holder 19 fixed to the clutch housing 9 and a holder 20 fixed to the transmission case 10 via bearings 21 and 22, respectively. The gear case 23 has a pair of bevel gears 26 and 26 that constitute a planetary gear with a revolving shaft 25 disposed perpendicular to the main shaft 11 and the first transmission gear shaft 16. It is rotatably supported.

Additionally, splines 11a are provided at the end of the main shaft 11 supported by the holder 19 via a bearing 27, and at the end of the first transmission gear shaft 16 supported by the holder 20 via a bearing 29. , 16
A bevel gear shaft 3 that constitutes an input gear and an output gear via a
0.31 is fixed, and each bevel gear 30.31 meshes with a pair of bevel gears 26.26, forming a planetary gear device.

Further, a slide pawl 32 is fitted into the spline lla of the main shaft 11 so as to be able to slide freely, and the slide pawl 32 has a pawl 32a that can engage with a pawl 23a formed on the inner peripheral surface of the gear case 23. are doing.

Furthermore, a pawl 19a is formed on the inner peripheral surface of the holder 19 adjacent to the gear case 23 in alignment with the pawl 23a, and the pawl 19a is fitted onto the main shaft 11 so as to be slidable and rotatable. A pawl 33a formed on the outer peripheral surface of another slide pawl 33 is engaged.

Further, a spring 35 is compressed between the slide pawl 32 and the bevel gear 30, and urges the slide pawl 32 and other slide pawls 33 to the left in the figure.

On the other hand, an operation pedal 36 is arranged in the driver's seat 7,
The pedal 36 is connected via a rod 37 or the like to a shifter fork arm 39 whose tip is in contact with the side surface of another slide pawl 33.

Since the present invention has the above-described configuration, when the tractor 1 is used for work in which forward and backward movement is rapidly switched, such as front loader work, the operating lever is first operated to set the desired traveling speed using the gear train 17. select.

In this state, when the clutch 13 is connected, the power of the engine 6 is transmitted to the main shaft 11, but the rotation of the main shaft 11 is controlled by the spring 3 as shown in FIG.
5, the pawl 32a of the slide pawl 32 is engaged with the pawl 23a of the gear case 23, and the bevel gear 30 is meshed with the pair of bevel gears 26 and 26 supported by the gear case 23, so that the bevel gear The bevel gear 26 rotates integrally with the gear case 23 without rotating around the revolution axis 25, and the revolution of the bevel gear 26 is transmitted to the first transmission gear shaft 16 via the bevel gear 31. 16 is main shaft 1
Rotates in the same direction and at the same speed as 1.

Thereby, the tractor 1 moves forward at the desired speed.

Next, in order to move the tractor 1 backward, the operating pedal 36 is depressed.

Then, the shifter fork arm 39 rotates clockwise, causing the other slide pawl 33 to slide together with the slide pawl 32 against the spring 35.

As a result, the claw 32a of the slide claw 32 is attached to the gear case 2.
At the same time as it comes off from the third slide claw 23a, the other slide claw 33
The claw 33a of the holder 19 remains engaged with the claw 19a of the holder 19, and also engages with the claw 23a of the gear case 23, thereby fixing the gear case 23.

In this state, the rotation of the main shaft 11 is controlled by the bevel gear 30.
is transmitted to a pair of bevel gears 26 and 26 through bevel gear 2.
6 is prevented from revolving, so it rotates around the shaft 25, and the rotation is transmitted to the first transmission gear shaft 16 via the bevel gear 31.

Therefore, the gear shaft 16 is in the opposite direction to the main shaft 11,
The motor rotates at the same speed and moves backward at a speed corresponding to the forward speed.

To move the tractor 1 forward again, take your foot off the operating pedal 36, slide the slide claw 32 by the spring 35, remove the claw 33a of the other slide claw 33 from the claw 23a of the gear case 23, and then 23a.

As explained above, according to the present invention, the operating pedal 36
The vehicle can be moved forward or backward with simple operations such as stepping on the front loader of a tractor, so there is no need to perform many operations in an instant, such as switching the vehicle forward or backward, as well as lifting or lowering the loader or front processing unit. This makes it very easy to carry out the work, and since the gears can be changed independently and the reverse speed corresponds to the multiple forward speeds, the work can be done efficiently.

In addition, unlike power shift and hydraulic transmission devices, special equipment such as a hydraulic device is not required, and a simple mechanical structure is sufficient, making it possible to obtain a robust and inexpensive device. By providing it within a certain clutch housing 9, the forward and backward movement device 15 can be installed without making any special changes to the transmission case 10 and the clutch housing 9, and can be easily installed in an existing tractor.

Furthermore, two slide claws 32 and 33 arranged adjacently
Since the forward/reverse movement device 15 is switched by sliding the gear case 23 as a unit, the gear case 23
The two operations of connecting and disconnecting the gear case 23 to the transmission shaft 11 (or 16) and connecting and disconnecting the gear case 23 to the fixed holder 19 (or 20) can be performed accurately without timing deviation, ensuring that malfunctions occur. It is possible to prevent this from happening, and maintenance becomes extremely easy.

[Brief explanation of drawings]

FIG. 1 is an overall side view showing a tractor to which the present invention is applicable, FIG. 2 is a cross-sectional view showing its power transmission system, and FIG. 3 is a cross-sectional view showing a forward and backward movement device according to the present invention. 1...Tractor, 6...Engine, 9
......Clutch housing, 10...Mission case, 11.16...Transmission shaft, 15
...Forward/backward movement device, 19.20...Fixed holder, 19a...Curved claw, 23...Gear case, 22a...Claw, 26... ... Planetary gear, 30 ... Input gear, 31 ... Output gear, 26, 30. 31 ... Planetary gear device, 32
...First slide claw, 33...Second
Slide claw, 36...operation pedal.

Claims (1)

[Scope of utility model registration request] In a tractor that has an engine, a clutch housing, and a transmission case, and transmits power from the engine to a traveling axle via a transmission shaft in the clutch housing and a gear train built in the transmission case, a planetary gear is installed in the clutch housing. A device is provided to fix the input gear of the planetary gear device to a transmission shaft linked to the engine, and fix the output gear to the transmission shaft linked to the gear train, further supporting the planetary gear. A gear case is rotatably supported on a fixed holder, and claws are formed on the inner circumferential surface of the gear case and on the inner circumferential surface of the fixed holder adjacent thereto, and the gear case is slidable only on the transmission shaft. 1st
A sliding pawl is provided, and a second sliding pawl is provided adjacent to the first sliding pawl and rotatably and slidably on the transmission shaft.The first and second sliding pawls are integrated. There is a forward rotation position where the first slide claw engages with the gear case claw and the second slide claw only engages with the fixed holder claw, and a forward rotation position where the first slide claw is removed from the gear case claw. A forward and backward movement device for a tractor, wherein the second sliding pawl is switched to a reverse position in which it engages with a pawl of a gear case and a pawl of a fixed holder.