JP2758318B2 - Travel transmission structure of work vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling power transmission structure for a working vehicle having a pair of left and right traveling devices such as a multi-wheel type and a crawler type with four wheels on one side.

[0002]

2. Description of the Related Art As an example of the working vehicle as described above, there is a combine equipped with a pair of right and left crawler type traveling devices.
-46871. In this structure, as shown in FIG. 2 of the publication, a pair of left and right side gears (12 in FIG. 2 of FIG. 2) for transmitting power to the traveling device are driven by a first transmission gear for straight traveling (FIG. 2 of the publication). 7) and
A second transmission gear for turning (9 in FIG. 2 of the above publication) is arranged. The power for traveling from the engine is shifted by a transmission (M in FIG. 2 of the above publication) and transmitted to the first transmission gear via a transmission shaft (24 in FIG. 2 of the above publication) as power for straight traveling. The power for straight traveling transmitted to the first transmission gear is transmitted to the second transmission gear through a speed reduction operation from the transmission shaft.

[0003] When the left and right side gears are connected to the first transmission gear in an interlocked manner, forward rotation power of the same speed is transmitted from the left and right side gears to the left and right traveling devices, so that the aircraft goes straight. Then, as shown in FIG. 2 of the above publication, when the left side gear is slid from the first transmission gear to the left in the drawing and is interlocked with the second transmission gear, the low-speed forward rotation transmitted to the second transmission gear is achieved. Power is transmitted to the left traveling device,
The left traveling device is driven at a lower speed than the right traveling device,
The aircraft slowly turns left due to the speed difference between the left and right traveling devices.

[0004]

A work vehicle such as a combine as described above travels on a work place having a large running resistance such as a soft field or a rough ground. Therefore, by increasing the number of gears on the low speed side in the traveling transmission, the traveling device can be driven with low-speed and high-torque power in accordance with various conditions of the work place to travel. Is preferred. However, there is a limit to increasing the number of gears of the transmission for traveling due to restrictions such as arrangement space. SUMMARY OF THE INVENTION It is an object of the present invention to provide a configuration in which, in a state where the number of gears of a traveling transmission is as large as possible, an existing structure can be effectively used to add one lower gear.

[0005]

The feature of the present invention resides in the following construction in the traveling power transmission structure for a working vehicle as described above. That is, a first transmission gear for straight traveling and a second transmission gear for turning are arranged for a pair of left and right side gears for transmitting power to each of the pair of left and right traveling devices, and each of the left and right side gears is connected to the first transmission gear. Independently and slidably supported between an interlocking connection position with the transmission gear and an interlocking connection position with the second transmission gear, the first transmission gear is operated as a power for straight-forward operation by shifting the power for traveling from the engine. And a reduction gear that reduces the speed of the straight-moving power transmitted to the first transmission gear and transmits the power to the second transmission gear, and the left and right gears at an interlocking connection position with the first transmission gear. Out of the side gears, the selected one of the side gears is slid to an interlocking connection position with the second transmission gear, and one of the traveling devices is driven at a lower speed than the other to rotate the body.
There is provided an operating means and a second operating means capable of operating both the left and right side gears in an interlocking connection position with the second transmission gear prior to the first operating means.

[0006]

With the above-described structure, for example, as shown in FIG. 1, the forward rotation power for straight traveling from the transmission 42 on the upper side is transmitted to the first transmission gear 24. Then, the forward rotation power for straight traveling transmitted to the first transmission gear 24 is decelerated and transmitted to the second transmission gear 30. Thus, when the left and right side gears 26 are interlocked with the first transmission gear 24, the forward rotation power for straight traveling is transmitted to the left and right traveling devices 27 via the side gears 26, and the aircraft advances straight.
Then, for example, the left side gear 26 is
Is moved away from the first transmission gear 24 and is linked to the second transmission gear 30, the low-speed forward rotation power of the left second transmission gear 30 is transmitted to the left traveling device 27 via the side gear 26. The aircraft turns slowly to the left.

In the above structure, both the left and right side gears 26 are moved by the second operating means to the second transmission gear 30.
, The low-speed forward power transmitted to the second transmission gear 30 (the forward power that is lower than the straight forward power transmitted to the first transmission gear 24) is transmitted to the left and right side gears. The driving force is transmitted to the left and right traveling devices 27 through 26. Thus, the aircraft advances at a lower speed than in a state in which the left and right side gears 26 are interlocked to the first transmission gear 24. In other words, an apparently additional speed stage is added to the traveling transmission.

[0008]

As described above, by effectively utilizing the existing structure of the second transmission gear for gentle turning, the reduction gear, and the like, the number of gears of the transmission for traveling is increased as much as possible. (Or in a state where the number of gears is not increased), one low-speed gear can be increased. As a result, it is easy to obtain gears according to various conditions of the work place, and the traveling performance of the work vehicle can be improved. Further, the present invention can be obtained only by adding a structure (second operation means) for preferentially operating the left and right side gears without particularly changing the transmission for traveling, so that the structure is advantageous in terms of production cost. Become.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a structure in a transmission case 1 of a traveling system of a combine, which is one of working vehicles, in which power from an engine (not shown) is connected to a belt transmission mechanism (not shown) having a tension clutch. The power is transmitted to the input pulley 3 of the belt-type continuously variable transmission 2 through the transmission. Power from the output shaft 4 of the belt-type continuously variable transmission 2 is cut via a first gear 5, a second gear 6, a first transmission shaft 7, a third gear 8, a fourth gear 9 and an output pulley 10 ( (Not shown).

A forward gear 11 and a reverse gear 12 are rotatably fitted to the first transmission shaft 7 so as to be relatively rotatable. A shift gear 13 is slidably movable between the forward and reverse gears 11 and 12 by a spline structure. Is fitted outside. With this structure, when the shift gear 13 is engaged with the forward gear 11, the power of the first transmission shaft 7 is moved forward and the fifth gear 14
(Occlusion with the forward gear 11) to the second transmission shaft 15. When the shift gear 13 is engaged with the reverse gear 12, the power of the first transmission shaft 7 is moved in reverse and the reverse gear 12, the sixth gear pair 16, and the fifth gear 14 (the sixth gear pair 1).
6 and is transmitted to the 22nd transmission shaft 15.

A first high-speed gear 17 is fitted on the second transmission shaft 15 so as to be relatively rotatable, and a shift gear 18 is fitted with a spline structure so as to be slidable. A cylindrical shaft 39 is externally rotatably fitted to a third transmission shaft 19 disposed in the transmission case 1. The low-speed gear 20, the medium-speed gear 21, and the second high-speed gear 2
2 is fixed, and the first and second high-speed gears 17 and 22 are engaged.

As a result, the shift gear 18 is slid to operate the first high-speed gear 17, the medium-speed gear 21, and the low-speed gear 2.
0, the forward rotation power from the second transmission shaft 15 can be shifted to three stages of high, medium, and low. This forward rotation power is transmitted from the linear gear 23 fixed to the cylindrical shaft 39 to the first rotation. The power is transmitted to one transmission gear 24. As described above, the shift gear 18, the cylindrical shaft 39, the low-speed gear 20, and the like constitute a gear transmission type transmission 42 for traveling.

Right and left side gears 26 are externally fitted to a support shaft 25 supporting the first transmission gear 24 so as to be relatively rotatable, and input gears 28 of left and right traveling devices 27 always mesh with the left and right side gears 26. ing. As a result, the left and right side gears 26 engage with the first transmission gear 24 (the first transmission gear 2).
4) to transmit the forward rotation power for straight traveling to the left and right crawler-type traveling devices 27. The spring 29 connects the side gear 26 to the first transmission gear 2.
It is biased to the 4 side.

A pair of second transmission gears 3 are provided on the left and right sides of the support shaft 25.
0 is externally fitted, and a multi-plate friction clutch 31 is provided between the left and right second transmission gears 30 and the side gears 26. A left turning gear 32L is fixed to one end of the third transmission shaft 19, and the left turning gear 32L is connected to the left second transmission gear 30.
The right turning gear 32R is slidably fitted to the other end of the third transmission shaft 19 in a spline structure, and the right turning gear 32R is fitted to the right second transmission gear 30. Occluded. Then, the seventh gear 4 is connected to the first transmission gear 24.
The fourth gear 4 is fixed, and an eighth gear 45 externally fitted to the third transmission shaft 19 so as to be relatively rotatable is engaged with the seventh gear 44. Further, a switching lever 41 capable of sliding the right turning gear 32R is provided in a control section of the fuselage.

With the above structure, as shown in FIG. 1, the switching lever 41 is operated to the gentle turning position and the right turning gear 32R is operated.
Is slid leftward on the paper, the right turning gear 32R
Are engaged with the eighth gear 45. Accordingly, the forward rotation power for straight traveling transmitted to the first transmission gear 24 is transmitted to the seventh gear 4.
Fourth, the speed is reduced via the eighth gear 45, the right turning gear 32R, the third transmission shaft 19, and the left turning gear 32L, converted into low-speed forward power, and transmitted to the left and right second transmission gears 30. (Equivalent to a reduction gear). Therefore, for example, when the left side gear 26 is operated to be separated from the first transmission gear 24 and the friction clutch 31 is pressed and operated by the pressing portion 43 of the left side gear 26 (corresponding to an interlocking connection position with the second transmission gear 30), The low-speed forward rotation power of the left second transmission gear 30 is transmitted to the left traveling device 27, and the aircraft slowly turns left due to the speed difference between the left and right traveling devices 27.

Next, when the switching lever 41 is operated to the pivot position and the right turning gear 32R is slid rightward on the drawing surface, the right turning gear 32R is separated from the eighth gear 45, and the transmission case 1 Engages with the convex portion 1a on the inner surface of. Thus, the left and right second transmission gears 30 are stopped and held by the right turning gear 32R, the third transmission shaft 19, and the left turning gear 32L. Thereby, for example, the left side gear 26 is operated to be separated from the first transmission gear 24, and the left side gear 26
When the friction clutch 31 is pressed and operated by the pressing portion 43, the left traveling device 27 is braked, and the machine body turns left and right.

Next, the sliding operation structure of the left and right side gears 26 will be described. As shown in FIGS. 2 and 1, an operation arm 38 for sliding the left and right side gears 26 is provided.
And a hydraulic cylinder 33 (corresponding to first operating means) for swinging the hydraulic cylinder. In this case, the hydraulic cylinder 33 is provided with a spring (not shown) for urging the hydraulic cylinder 33 toward the contraction side, and hydraulic oil from a pump 34 is supplied to an electromagnetically operated control valve 35 for the hydraulic cylinder 33. I have. When the hydraulic cylinder 33 extends until the side gear 26 moves away from the first transmission gear 24 and moves to a neutral stop position where the friction clutch 31 is not pressed and operated, the hydraulic oil is removed from the hydraulic cylinder 33 and the hydraulic cylinder 3 is released.
A drain oil passage 36 for stopping the engine 3 at the neutral stop position is provided, and a variable relief valve 37 is provided in the drain oil passage 36.

Next, the control valve 35 and the variable relief valve 37
The operation of is described. The state shown in FIG. 2 and FIG.
The left and right side gears 26 are in a straight running state in which the first transmission gears 24 are engaged. In this state, for example, when the operation lever 40 is operated to the left first turning position L1, only the control valve 35 is switched to supply the hydraulic oil to the left hydraulic cylinder 33, and the left side gear 26 slides to the left on the paper. First
Move away from the transmission gear 24. In this case, the variable relief valve 3
7 is fully opened, the drain oil passage 36 is opened at the neutral stop position before the left side gear 26 presses the friction clutch 31, and the hydraulic oil flows out of the variable relief valve 37, so that the left side gear 26 is in the neutral position. Stop at the stop position. This is a state in which the transmission to the left traveling device 27 is cut off, and the aircraft gradually turns left.

When the operating lever 40 is operated to the left second turning position L2, the variable relief valve 37 is throttled, the hydraulic cylinder 33 is extended from the neutral stop position, and the left friction clutch 31 is engaged. Is done. in this case,
As shown in FIG. 1, if the switching lever 41 is operated to the gentle turning position to engage the right turning gear 32R with the eighth gear 45, the left traveling device 27 is driven forward at low speed to make a gentle turning. Can be performed. Further, the left first turning position L1 and the second turning position L2
When the operating lever 40 is operated between the above state, the operating oil is released from the hydraulic cylinder 33 from the above-described state, and the friction clutch 3
The pressing force to 1 is reduced. Thereby, the friction clutch 31 slips and the forward rotation speed of the left traveling device 27 can be changed.

Conversely, if the switching lever 41 is operated to the pivot position to engage the right turning gear 32R with the projection 1a of the transmission case 1 and stop and hold it, the operation lever 40 is operated. When operated to the left second turning position L2, the left traveling device 27 is braked to perform a pivot turn. or,
Move the operating lever 40 to the left first and second turning positions L1 and L2.
In this case, the friction clutch 31 slides and the braking force on the left traveling device 27 can be changed as described above.
The above operation is performed on the right first turning position R1 and the second turning position R
2 is performed similarly.

Next, a description will be given of a structure in which the left and right side gears 26 travel straight at a lower speed than the straight travel state in which the first transmission gear 24 is engaged. As shown in FIG.
8 is connected to one end of an arm 38a of the release wire 46, and the other operation arm 3
The outer 46b is connected to the eighth arm 38a.
In addition, a deceleration pedal 47 (corresponding to a second operation means) is provided in a control section of the fuselage, and an inner 46a of the release wire 46 is connected to the deceleration pedal 47. And a switching lever 4 for switching between a gentle turning state and a pivot turning state.
1 and the deceleration pedal 41 are connected by a wire 48.

With the above structure, the left and right side gears 26
When the deceleration pedal 47 is depressed in a straight-ahead state in which is engaged with the first transmission gear 24, the operation arm 38 on the right side of the drawing is swung counterclockwise by the pulling action of the inner 46a of the release wire 46, Outer 4
By the action of 6b, the operation arm 38 on the left side of the paper is swung clockwise. Thereby, the left and right side gears 26
Are operated to be separated from the first transmission gear 24 to the left and right, and the left and right side gears 26 press and engage the left and right friction clutches 31. At the same time, by the pulling action of the wire 48, the switching lever 41 is operated from the pivot turning position to the gentle turning position. If the switching lever 41 has already been operated to the gentle turning position, the switching lever 41 remains at the gentle turning position.

As described above, when the left and right side gears 26 and the switching lever 41 are operated, the straight forward power transmitted to the first transmission gear 24 is transmitted to the seventh gear 44, the eighth gear 45, and the right gear. The speed is reduced through the turning gear 32R, the third transmission shaft 19, and the left turning gear 32L to be converted into low-speed forward power, and the second transmission gear 30 and the left and right side gears 26 are rotated.
Is transmitted to the left and right traveling devices 27 via the. Thereby, the aircraft advances straight at a lower speed than the straight running state in which the left and right side gears 26 are engaged with the first transmission gear 24.

[Alternative Embodiment] In the embodiment of FIG. 1, a state in which low-speed forward rotation power is transmitted to the second transmission gear 30 by the sliding operation of the right turning gear 32R (slow rotation state) and a state in which the second transmission is transmitted. Although the switching operation is performed in two states of a state in which the gear 30 is stopped and held (a pivoting state), the structure for stopping and holding the second transmission gear 30 is abolished, and the low-speed forward rotation power is reduced. Two transmission gears 30 may be configured to be constantly transmitted. In this case, the switching lever 41 shown in FIGS. 1 and 2 becomes unnecessary. In the embodiment of FIG. 1, the side gear 26 and the first transmission gear 24 have an occlusal structure,
The friction clutch 31 is provided between the side gear 26 and the second transmission gear 30, but the side gear 26 and the first transmission gear 2 are provided.
4, a friction clutch is provided between the side gear 26 and the second gear.
The transmission gear 30 and the transmission gear 30 may be configured in an occlusal structure, both may be configured in an occlusal structure, or both may be provided with a friction clutch. In the embodiment of FIG. 2, the deceleration pedal 47 is eliminated,
The function of the deceleration pedal 47 may be incorporated in a shift lever (not shown) for the transmission 42 in FIG. In this case, the shift lever is of a three-stage shift operation type of high, medium and low, so if an ultra low speed position is added to this and the shift lever is operated to the ultra low speed position, the shift gear 18 of the transmission 42 engages with the low speed gear 20, The left and right side gears 26 are the left and right friction clutches 31
, The switching lever 41 is operated to the gentle turning position.

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 transmission structure of a traveling system in a transmission case.

FIG. 2 is a diagram showing a circuit of a hydraulic cylinder for sliding operation of a side gear, and a linkage structure between a reduction gear and a side gear.

[Explanation of symbols]

 24 first transmission gear 26 side gear 27 traveling device 30 second transmission gear 33 first operation means 42 transmission 47 second operation means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-46871 (JP, A) JP-A-3-153478 (JP, A) JP-A-4-37077 (JP, U) JP-A-61- 157063 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) B62D 11/04-11/08

Claims (1)

(57) [Claims] 1. A pair of left and right side gears (26) for transmitting power to each of a pair of left and right traveling devices (27).
A first transmission gear (24) for straight traveling and a second transmission gear (30) for turning are arranged, and each of the left and right side gears (26) is connected to an interlocking connection position with the first transmission gear (24). ,
It is independently slidably supported over an interlocking connection position with the second transmission gear (30), and the speed of the traveling power from the engine is shifted to the first transmission gear (24) as straight-line power. A transmission (42) for transmitting the power; and a reduction gear for transmitting the power for straight traveling transmitted to the first transmission gear (24) to the second transmission gear (30) by performing a speed reduction operation. One of the left and right side gears (26) at the interlocking connection position with the first transmission gear (24) is slid to one of the selected side gears (26) at the interlocking connection position with the second transmission gear (30). Traveling equipment (27)
And the left and right side gears (26) in preference to the first operating means (33) and the second transmission gear (30). And a second operating means (47) operable at an interlocking connection position with the driving transmission structure of the working vehicle.