JP3005160B2 - Work vehicle shifting structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission structure of a working vehicle such as a combine, for example, and more particularly to a work structure in which a shift output from a belt-type continuously variable transmission is transmitted into a traveling transmission case. The present invention relates to a vehicle speed change structure.

[0002]

2. Description of the Related Art Conventionally, as a transmission structure of this type of work vehicle, a gear-type auxiliary transmission is provided in a traveling transmission case to which a transmission output from a belt-type continuously variable transmission is input. And a gear-type forward / reverse switching clutch for selectively transmitting forward power and reverse power to the traveling device with a lower transmission than the auxiliary transmission.

[0003]

However, in the above-mentioned conventional structure, the transmission belt in the belt-type continuously variable transmission is connected to the transmission belt from the traveling device via the axle, the forward / reverse switching clutch, the auxiliary transmission, and the like. Since it was transmitted as a traveling load, there is a high possibility that an instantaneous excess load acts on the transmission belt more than the auxiliary transmission during traveling, and such an instantaneous excessive load acts on the transmission belt. In this case, there is a possibility that a trouble such as a break of the belt may occur. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a transmission structure of a work vehicle capable of suppressing transmission of an instantaneous excessive load from a traveling device to a belt continuously variable transmission. .

[0004]

Means for Solving the Problems] transmission structure of the working vehicle according to the present invention, in order to achieve the above object, in a traveling transmission case shift output from the belt type continuously variable transmission is input, forward To transmit power for power transmission to the lower side
Hydraulic clutch and the power for reverse drive to the transmission lower side
A reverse hydraulic clutch, and a subtransmission.
To the rotation axis of each hydraulic clutch.
With narrow part and narrow part
The forward hydraulic clutch and the rear
A hydraulic clutch is provided and the lower power transmission than this narrow part
The sub-transmission is arranged in the wide portion on the side . The operation and effect of this characteristic configuration are as follows.

[0005]

The clutch mechanisms for transmitting the forward power and the reverse power to the lower transmission side in the transmission case are each constituted by a hydraulic clutch, which is closer to a belt type continuously variable transmission than an auxiliary transmission. Since these hydraulic clutches are provided, even if a change in the load from the traveling device is transmitted to the transmission skill through the auxiliary transmission, the hydraulic clutch will buffer the change. Further, the auxiliary transmission which requires a relatively large installation volume is disposed on the lower transmission side, and the hydraulic clutch for forward and reverse which can be configured compactly is disposed on the upper transmission side. Since the width of the transmission can be set relatively small and a belt-type continuously variable transmission or the like can be disposed at the set position, the overall configuration can be made compact.

[0006]

Thus, according to the present invention, the transmission of the impact or the like due to the variation of the running load to the belt-type continuously variable transmission is suppressed by the hydraulic clutch for forward / reverse switching, so that the durability of the transmission belt is reduced. As a result, the transmission can be made compact as a whole.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a combine transmission as an example of a work vehicle. That is, power from an engine (not shown) is transmitted to an input pulley 2 of a belt-type continuously variable transmission 1 via a belt transmission mechanism (not shown) having a tension clutch, and the belt-type continuously variable transmission is provided. The output power from the device 1 is input into the transmission case 3.

As shown in FIG. 1, in the transmission case 3, a forward transmission shaft 4 and a reverse transmission shaft 5 are arranged in parallel along the front-rear direction of the transmission case 3. 1 is deviated from the left and right center to one lateral side to the left in FIG. A forward hydraulic clutch 6 and an input gear 7 for transmitting forward power to a lower transmission side in the transmission case 3 are mounted on the forward transmission shaft 4, and transmit reverse power in the transmission case 3. A reverse hydraulic clutch 8 and an input gear 9 for transmission to the lower side are attached to the reverse transmission shaft 5.

In the upper part of the transmission case 3, FIG.
The transmission shafts 4 and 5 for forward and reverse
Hydraulic oil from a directional control valve as a forward / reverse switching valve, and hydraulic oil clutch for forward movement through internal oil passages 4a and 5a of transmission shafts 4 and 5 for forward and backward movement. 6 and the reverse hydraulic clutch 8. Further, as shown in FIG. 1, a gear pair 11, a first transmission shaft 12, an output shaft 13, and a hydraulic clutch 14 for a pre-cutting processing unit at a front part of the body of the combine, which are not shown, and , Belt type continuously variable transmission 1
The input shaft 15 for inputting power from the transmission shaft 3 is located above the forward and reverse transmission shafts 4 and 5 in the transmission case 3.
The transmission case 3 is biased to one side of the transmission case 3 on the same side as the transmission shafts 4 and 5 for forward and backward travel.

With the above structure, as shown in FIG. 1, the power from the belt-type continuously variable transmission 1 is applied to the input shaft 15 of the transmission case 3, the first transmission shaft 12, and the input gear 7 of the forward hydraulic clutch 6. The output gear 1 of the forward hydraulic clutch 6 and the reverse hydraulic clutch 8 is transmitted from the input gear 7 to the input gear 9 of the reverse hydraulic clutch 8.
Each of the gears 6 and 17 is engaged with the input gear 19 of the second transmission shaft 18. Accordingly, when hydraulic fluid is supplied to the forward hydraulic clutch 6 and the hydraulic oil is turned on, the power from the first transmission shaft 12 is transmitted through the input gear 7, the forward hydraulic clutch 6 and the output gear 16 to the 2 is transmitted to the transmission shaft 18. Conversely, when the hydraulic oil is supplied to the reverse hydraulic clutch 8 and the hydraulic oil is turned on, the power from the first transmission shaft 12 is reversed through the input gears 7 and 9, the reverse hydraulic clutch 8 and the output gear 17. Is transmitted to the second transmission shaft 18 in the reverse traveling state.

As shown in FIG. 1, a shift gear 20 is externally slidably fitted on a second transmission shaft 18 by a spline structure, and a high speed gear 22, a medium speed gear 23 and a low speed gear 24 are mounted on a third transmission shaft 21. Fixed. Thereby, the shift gear 20 is slid, and the high-speed gear 25, the medium-speed gear 22, or the low-speed gear 23 meshing with the high-speed gear 22 is engaged.
And shifts the power to three stages of high, medium and low.
This power is transmitted from the output gear 26 to the transmission gear 27. Here, the shift gear 20, the high-speed gear 22, the medium-speed gear 23, the low-speed gear 24, the high-speed gear 25, the second transmission shaft 18, and the third transmission shaft 21 constitute a gear-type auxiliary transmission 28.

As shown in FIG. 1, right and left side gears 30 are rotatably fitted on a support shaft 29 supporting a transmission gear 27, and input gears 32 of left and right axles 31 are connected to left and right side gears 30. Is always occluded. Support shaft 29
A multi-plate type side brake 33 is provided between the left and right side gears 30 and the transmission case 3 on both left and right ends of the transmission gear 2 by a spring 34.
7 is urged to the occlusal side. With the above structure, when the left and right side gears 30 are engaged with the transmission gear 27, the power from the third transmission shaft 21 is transmitted to the left and right crawler type traveling devices 35 via the transmission gear 27 and the left and right side gears 30. Then, the aircraft goes straight. Then, when the right or left side gear 30 is operated to be separated from the transmission gear 27 and the side brake 30 is pressed and operated by the side gear 30, braking is applied to one of the traveling devices 35, and the aircraft body turns around.

With the above structure, the gear type auxiliary transmission 28
The transmission lower hand of the forward hydraulic clutch 6 and the reverse hydraulic clutch 8 is disposed on the side, and the transmission lower hand of the belt-type continuously variable transmission 1 is connected to the forward hydraulic clutch 6 and the reverse hydraulic clutch 8. In the belt-type continuously variable transmission 1, even if an instantaneous load change such as an impact received by the traveling device 35 from the ground is transmitted to the transmission system, the belt-type continuously variable transmission 1 is disposed in the middle thereof. The forward hydraulic clutch 6 and the reverse hydraulic clutch 8 are used to absorb shocks, thereby avoiding improperly applying high tension to the transmission belt of the belt-type continuously variable transmission 1. The durability of the transmission belt can be increased.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a shift structure of a work vehicle.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 belt-type continuously variable transmission 3 traveling mission case 6 forward hydraulic clutch 8 reverse hydraulic clutch 28 auxiliary transmission

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B60K 17/08

Claims (1)

(57) [Claims] 1. A traveling transmission case (3) to which a shift output from a belt-type continuously variable transmission (1) is input.
Hydraulic clutch for forward transmission that transmits forward power to the transmission lower side
H (6) and the reverse to transmit the power for reverse to the lower transmission side
Hydraulic clutch (8) and an auxiliary transmission (28).
Then, the transmission case (3) is
(6), (8) a narrow portion in which the width in the rotation axis direction is narrow.
And a wide part with a wide width.
The forward hydraulic clutch (6) and the reverse hydraulic clutch
(8), which is wider on the lower transmission side than this narrow part.
A transmission structure of a work vehicle in which a subtransmission (28) is disposed in a part .