JPH04271969A - Traveling transmission structure for working vehicle - Google Patents

Abstract

PURPOSE:To improve safety by preventing the excessively small turn in a moderate turn by installing a moderate turn mechanism for carrying out turn by driving one traveling device at the lower speed than that of the other traveling device, in a traveling transmission structure of a working vehicle equipped with the left and right traveling devices in pair. CONSTITUTION:When a selecting lever 43 is selection-operated to the state where turning by a moderate turning mechanism is carried out, the speed change lever 45 of a speed change device 35 for traveling can not be operated to a high speed side by the action of a restraining means 46.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling transmission structure for a working vehicle equipped with a pair of left and right crawler or multi-wheel traveling devices.

0002

[Prior Art] As an example of the above-mentioned work vehicle, there is a combine harvester equipped with a crawler-type traveling device, and its traveling transmission system transmits power from an engine to variable speeds through a traveling transmission. , the power is branched from the lower side of this transmission and transmitted to the left and right traveling devices. In such a combine harvester, it has been considered to provide a slow turning mechanism on the downstream side of the transmission so that one selected traveling gear is driven at a lower speed than the other traveling gear. Thereby, by operating the slow turning mechanism and driving one of the traveling devices at a low speed, the aircraft can reliably turn with a turning radius based on the speed difference between the left and right traveling devices.

0003

[Problem to be solved by the invention] The above-mentioned gentle rotation mechanism has the following features:
It is configured to reduce the power output from the transmission at a constant reduction ratio and transmit it to one of the traveling devices. Therefore, suppose that the reduction ratio in the slow turning mechanism is set to, for example, 1/2. In this case, if the slow turning mechanism is activated while traveling straight at a relatively high speed VH, one traveling gear will be decelerated to 1/2 VH (the opposite traveling gear will remain at speed VH). ), the speed difference between the left and right running gear is VH (
1-1/2), and as the speed VH increases, the speed difference between the left and right traveling devices also increases accordingly. This results in
If the aforementioned slow turning mechanism is activated while the vehicle is traveling straight at high speed, the large speed difference will cause the vehicle to suddenly start a slow turn, so there is room for improvement in terms of safety. The present invention
The purpose of this invention is to improve safety when starting a slow turn by operating the above-mentioned slow turning mechanism.

0004

[Means for Solving the Problems] The feature of the present invention is that the traveling transmission structure for a working vehicle as described above is configured as follows. In other words, a slow turning mechanism is provided on the lower side of the traveling transmission to drive one selected traveling gear at a lower speed than the other traveling gear so that it can turn, so that the left and right traveling gears are driven at the same speed. The system is configured to be able to freely switch between a straight-line state in which one traveling device is driven at a slow speed, and a slow turning state in which one traveling device is driven at low speed by a slow turning mechanism, and the transmission is operated at a high speed in conjunction with the switching operation to the slow turning state. Equipped with a check means to prevent operation to the side.

[0005]

[Operation] When configured as described above, assume that the reduction ratio in the slow turning mechanism is set to, for example, 1/2. in this case,
If the slow turning mechanism is activated while traveling straight at a relatively high speed VH, one of the traveling devices will be at a speed of 1/2V in that high speed state.
Since the speed is reduced to H, in the conventional configuration, the speed difference between the left and right traveling devices is VH (1-1/2) as described above. In contrast, in the present invention, when switching to a slow turning state while traveling at a relatively low speed, the restraining means prevents the transmission from being operated to the high speed side, resulting in a slow turning state at a relatively low speed. The mechanism must be activated. Therefore, if the speed at that time is VL, which is lower than the above-mentioned speed VH, the speed difference between the left and right traveling devices when turning in the present invention is VL (1-1/2). Therefore, if we compare the case of the conventional configuration and the case of the present invention, since VL<VH, VL(1-1/2)<VH(1-1/2), and the case of the present invention is better. This reduces the speed difference between the left and right traveling devices at the start of a slow turn, making it difficult for the vehicle to suddenly start a slow turn.

[0006]

Effects of the Invention When the slow turning mechanism is operated as described above, by configuring the slow turning mechanism so that it cannot be operated while traveling at high speed, a large speed difference between the left and right traveling devices can be avoided from a straight-ahead state. As a result, there are fewer situations where the vehicle suddenly starts making slow turns, improving the safety of the work vehicle.

[0007]

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings. Figure 3 shows the structure inside the transmission case 8 of the traveling system of a combine harvester, which is one of the working vehicles.
Power from the hydrostatic continuously variable transmission 1 is transmitted via a belt transmission mechanism (not shown) equipped with a tension clutch.
At the same time, the power from the output shaft 3 of the hydrostatic continuously variable transmission 1 is transmitted to the reaping section 6 via the first transmission shaft 4.

Power from the first transmission shaft 4 is transmitted to the second transmission shaft 11 via the first gear 9 and the second gear 10. A shift gear 14 is slidably fitted on the second transmission shaft 11 with a spline structure, and the first high-speed gear 1
2 is fitted on the outside so as to be relatively rotatable. On the other hand, a second high speed gear 16, a medium speed gear 18, and a low speed gear 17 are fixed to the third transmission shaft 15, and the first high speed gear 12 and the second high speed gear 16 are engaged with each other. With the above structure, the gear shift type transmission device 35 shifts the power into three stages of high, medium and low by sliding the shift gear 14 and engaging the first high speed gear 12, medium speed gear 18 and low speed gear 17.
This power is transmitted to the third gear 19 that meshes with the medium speed gear 18. As shown in FIGS. 1 and 4, a shift lever 45 for slidingly operating the shift gear 14 of the transmission 35 is provided.

A right side gear 21R and a left side gear 21L are fitted onto the support shaft 20 supporting the third gear 19 so as to be relatively rotatable, and the input gears 23R, 23L of the left and right axles 22L, 22R are connected to the left and right side gears 21L, 21R
is in constant occlusion. As a result, the right or left side gears 21R, 21L are slid to engage and separate from the third gear 19, thereby transmitting and interrupting power to the crawler-type traveling device 24. Side clutch 2 between left and right side gears 21L and 21R
5R and 25L are configured.

As shown in FIG. 3, a right fourth gear 26R and a left fourth gear 26L are supported by bearings on the support shaft 20 so as to be relatively rotatable.
The paired fifth gear 29 is the right fourth gear 26R and the left fourth gear 2.
Occlusal to 6L. The fourth transmission shaft 27 has a sixth gear 37.
is fitted onto the outside so as to be relatively rotatable, and a hydraulic clutch 30 is provided between the sixth gear 37 and the fourth power transmission shaft 27.

On the other hand, a shift gear 5 is externally fitted onto the third transmission shaft 15 in a spline structure, and the shift gear 5 is positioned at a position where the shift gear 5 engages with a seventh gear pair 38 which engages with a sixth gear 37; It is constructed so that it can be slid freely over three positions: a position where it engages directly with the gear 37, and a neutral position where it does not engage with any of them. 7th gear pair 38 is mission case 8
The shift member 13 is fitted onto a fixed shaft 7 fixed to the fixed shaft 7 so as to be relatively rotatable, and the shift member 13 fitted onto the fixed shaft 7 with a spline structure is engaged with the seventh gear pair 38, thereby shifting the seventh gear pair. 38 can be fixed.

Next, a configuration for applying braking to one axle 22R or 22L will be explained. As shown in FIG. 3, when the shift member 13 is engaged with the seventh gear pair 38, the sixth gear 37 is in a fixed state (the shift gear 5 is in the neutral position). As a result, when the hydraulic clutch 30 is engaged and operated with the right side gear 21R or the left side gear 21L separated from the third gear 19 and engaged with the right fourth gear 26R or the left fourth gear 26L, one of the axles 22R or 22L is engaged. Braking is applied. This is the turning state.

Next, a configuration for reversing one axle 22R or 22L will be explained. As shown in FIG. 3, when the shift gear 5 is directly engaged with the sixth gear 37, the power from the third transmission shaft 15 is transmitted to the sixth gear 37 in a reversed state and at a speed reduced to 1/2. (The shift member 13 is separated from the seventh gear pair 38). As a result, the right side gear 21R
Alternatively, the left side gear 21L can be replaced with the right fourth gear 26 as described above.
When the hydraulic clutch 30 is engaged and operated with the R or left fourth gear 26L engaged, the axle 22R or 22L is driven in a reversed state and decelerated to 1/2. And this is the state of super confidence turning.

Next, a description will be given of a configuration in which one axle 22R or 22L is driven to rotate normally at a lower speed than the other. As shown in FIG. 3, when the shift gear 5 is engaged with the seventh gear pair 38 which is engaged with the sixth gear 37, the forward rotational power from the third transmission shaft 15 is reduced to 1/2 and transferred to the sixth gear 37. is transmitted (the shift member 13 is separated from the seventh gear pair 38). As a result, when the hydraulic clutch 30 is engaged with the right or left side gears 21R, 21L engaged with the right or left fourth gears 26R, 26L, one of the axles 22R or 22L is driven at a low speed. And this is a slow turning state,
The slow rotation mechanism 4 is operated by the shift gear 5, the seventh gear pair 38, etc.
0 is configured.

Next, a structure for supplying hydraulic oil to the hydraulic clutch 30 and the hydraulic cylinders 31R, 31L for sliding the left and right side gears 21L, 21R will be explained. Figure 2
As shown in FIG. 3, the hydraulic oil from the pump 32 is supplied to the hydraulic cylinders 31R, 31L for the left and right side gears 21L, 21R via the switching valve 33, and the oil passage 34 from the side of the hydraulic cylinders 31R, 31L is connected to the hydraulic clutch. 3
Connected to 0. Furthermore, a variable relief valve 36 for the hydraulic clutch 30 is connected to the oil passage 34 . Next, operations of the switching valve 33 and the variable relief valve 36 will be explained. As shown in FIG. 2, a swing-type operating arm 28 for operating the variable relief valve 36 to the closing side is provided, and this operating arm 28 and an operating lever 39 are connected to a wire 4.
1 is mechanically linked. Furthermore, the operating lever 39 and the switching valve 33 are mechanically linked by a linkage mechanism 42.

The state shown in FIGS. 1 and 2 is a state in which the switching lever 43 for operating the shift gear 5 and the shift member 13 is operated to the slow rotation position, and the shift gear 5 is engaged with the seventh gear pair 38. This is a state in which low-speed normal rotational power is being transmitted to the sixth gear 37. In this state, the operating lever 39
When the switch is operated from the neutral position N to the first right turning position R1 or the first left turning position L1, only the switching valve 33 is operated and the right or left operating part 46 is operated by the hydraulic cylinder 31R or 31L.
The right or left side gears 21R, 21L that were engaged with the third gear 19 are separated from the third gear 19 via R, 46L, and are engaged with the right or left fourth gears 26R, 26L.

In this case, since the variable relief valve 36 is fully open and the hydraulic clutch 30 is disengaged, the power transmission to the right or left axles 22R, 22L is cut off (
(side clutch 25R or 25L is disengaged), and the aircraft slowly changes direction to the right or left. Further, the sequence valve 47 provided in the oil passage 34 is configured such that the right or left side gears 21R, 21L are connected to the right or left fourth gear 26R,
This is to ensure that the hydraulic cylinders 31R and 31L have the pressure necessary to completely engage the cylinder 26L.

Next, when the operation lever 39 is operated from the right or left first rotation position R1, L1 to the right or left second rotation position R2, L2, the operation arm 28 is moved to the position shown in FIG. The variable relief valve 36 is operated to the closing side by being oscillated clockwise in the paper. As a result, the hydraulic clutch 30 starts to be engaged and operated, and the right or left axle 22
R and 22L are gradually driven forward at low speed, and the aircraft slowly turns to the right or left. Then, when the operating lever 39 is in the right or left second turning position R2, L2, the hydraulic clutch 30 is fully engaged.

As shown in FIGS. 1 and 4, FIG.
A shift lever 45 for the transmission 35 is supported to be swingable around an axis P1, and a check arm 46 (having an L-shape in plan view) is swingably supported around an axis P2 perpendicular to the axis P1.
This check arm 46 and the switching lever 43 are linked by a wire 48.

With the above structure, when the switching lever 43 is operated to the slow rotation position as shown in FIGS. 1 and 4, the check arm 46 enters the operation path of the gear shift lever 45. As a result, the speed change lever 45 can only be operated to a medium speed position and a low speed position, and cannot be operated to a high speed position. Conversely, even if you try to operate the switching lever 43 to the slow swing position while the shift lever 45 is being operated to the high speed position, the check arm 46 will come into contact with the shift lever 45, so the switching lever 43 will not be moved to the slow swing position. It can not be operated.

Furthermore, as shown in FIG.
contacts the shift lever 45 in a state oblique to the operating path of the shift lever 45 when viewed from above, and the check arm 46 is obliquely oblique to the shift lever 45 when viewed from the front as shown in FIG. Therefore, when the shift lever 45 is operated to the high speed position in the state shown in FIGS. 1 and 4 (with the shift lever 45 in the medium or low speed position and the switching lever 43 in the slow rotation position), The check arm 46 is lifted and the switching lever 43 is returned to the neutral position N1 and operated. This neutral position N1 is an intermediate position between a pivot turning position and a slow turning position, which will be described later, and is a position before the shift gear 5 is separated from the seventh gear pair 38 in FIG. It is. In this state, no power flows to the lower sixth gear 37 and the hydraulic clutch 30, and the right and left fourth gears 2
Since 6R and 26L are in a free rotating state, the operating lever 3
9 to the right or left second turning position R2, L2 will not cause a slow turning state.

Next, the pivot turning state will be explained. Figure 1
As shown in FIG.
is engaged with the seventh gear pair 38 to fix the sixth gear 37, and the shift gear 5 is placed in the neutral position. In this state, when the operating lever 39 is operated from the neutral position N to the right or left first turning position R1, L1, the side clutch 25R or 25L is disconnected as described above, and the aircraft gently turns to the right or left. I'm going to change it. Next, when the operation lever 39 is operated to the right or left second rotation position R2, L2, the variable relief valve 36 is gradually operated from the fully open state to the closed side. As a result, the hydraulic clutch 30 is engaged and operated,
Braking is gradually applied to the right or left axles 22R, 22L, and the aircraft turns to the right or left. Then, the braking force becomes maximum at the right or left second turning position R2, L2 of the operating lever 39.

Next, the super-turning state will be explained. As shown in FIG. 1, the switching lever 43 is operated to the super pivot position to separate the shift member 13 from the seventh gear pair 38 and cause the shift gear 5 to engage directly with the sixth gear 37. In this state, when the operating lever 39 is operated from the neutral position N to the right or left first turning position R1, L1, the side clutch 25R or 25L is disconnected as described above, and the aircraft gently turns to the right or left. I'm going to change it. Next, when the operation lever 39 is operated to the right or left second rotation position R2, L2, the variable relief valve 36 is gradually operated from the fully open state to the closed side. As a result, the hydraulic clutch 30 is engaged and operated,
The right or left axles 22R, 22L are driven in reverse, and the aircraft makes a sharp turn to the right or left.

As shown in FIGS. 1 and 3, the fourth power transmission shaft 2
A main brake 49 for parking is provided at one end of 7.
A brake pedal 50 and a main brake 49 are linked by a wire 51. The inner end of another wire 52 is connected to the brake pedal 50, and the inner end of this wire 52 on the other end side is connected to the right operating section 46R shown in FIG. 2, and the outer end is connected to the left operating section 46L. With the above structure, when the brake pedal 50 is depressed and operated, the right and left side gears 2
1R and 21L are engaged with the right and left fourth gears 26R and 26L, and the main brake 49 is engaged and operated. A parking operation can be performed by fixing the brake pedal 50 at the depressed position using the locking member 53.

In this case, as shown in FIG. 1, a rod-shaped linkage mechanism 54 that can be operated by pushing the switching lever 43 is connected to the brake pedal 50. With the above structure, when a parking operation is performed using the brake pedal 50 while the switching lever 43 is operated to the slow turning position as described above, the switching lever 43 is operated to the neutral position N1 by the linkage mechanism 54. .

Next, the support structure for the wheels 60 in the traveling device 24 will be explained. As shown in FIG. 5, a support pipe 62 is fixed to a fixed truck frame 61, and a stop member 58 to which a nut 57 is welded and fixed is prepared. On the other hand, the bearing 55 and the support shaft 56 are attached to the roller 60.
etc., and these are constructed as an integrated part. With the above structure, the rolling wheels 60 are connected to the track frame 61.
When installing the support shaft 56 of the rolling wheel 60 into the support pipe 62, turn the head 56a of the support shaft 56 with a wrench, etc., and screw the end of the support shaft 56 into the nut 57 of the stopper member 58 to fix it. do. The stopper member 58 is prevented from rotating by the contact between its upper end 58a and the upper surface of the track frame 61 and by the pin 61a fixed to the track frame 61. To remove the wheel 60, the cap 59 of the wheel 60 is removed, the head 56a of the support shaft 56 is turned with a wrench, etc., and the support shaft 56 is removed from the nut 57 of the stopper member 58.

[Another Embodiment] In the above embodiment, when the switching lever 43 is moved to the slow turning position, the gear shift type transmission 35 cannot be operated to the high speed side. However, when the switching lever 43 is moved to the slow turning position, It may be configured such that the hydrostatic continuously variable transmission 1 (corresponding to a transmission for traveling) cannot be operated to the high speed side when operated.

[0028] Although reference numerals are written in the claims section for convenience of comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of the drawing]

[Fig. 1] A diagram showing the interlocking state of a switching lever for selecting a turning state, a shift lever for a transmission, and a brake pedal for a main brake.

[Figure 2] Hydraulic circuit diagram showing the interlocking state of the steering control lever, hydraulic cylinders for left and right side gears, and hydraulic clutches

[Figure 3] Schematic diagram showing the transmission structure inside the mission case

[
Figure 4: Plan view of the gear lever and restraint arm for the transmission

[Figure 5] Longitudinal front view of the vicinity of the wheels of a crawler-type traveling device

[Explanation of symbols]

1,35 Transmission device for driving 24 Traveling device 40 Slow rotation mechanism 46 Checking measures

Claims (1)

[Claims] Claim 1: A vehicle is equipped with a pair of left and right traveling devices (24), and transmits power from an engine to transmission devices (1), (3) for traveling.
5), and this transmission device (1), (35
), the power is branched from the lower side of the left and right traveling devices (
A traveling transmission structure for a work vehicle configured to transmit power to a vehicle (24), wherein one selected traveling device (24) is driven at a lower speed than the other traveling device (24) to enable turning. The slow rotation mechanism (40) to rotate the transmission (1)
), (35) on the lower side to connect the left and right traveling devices (24).
) are driven at the same speed, and the slow turning mechanism (
40), one of the traveling devices (24) is configured to be able to be freely switched to a slow turning state in which the one traveling device (24) is driven at a low speed, and the transmission device (1)
, (35) to the high speed side.
) Travel transmission structure for work vehicles.