JP2000186761A - Transmission for working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve speed change operability from working travel at low speed to moving travel to high speed. SOLUTION: An auxiliary transmission 9 and a main transmission 10 are interposed in serially connected/placed state in a transmission system to a travel device 1. As the main transmission 10, a device changing speed in multi steps by alternatively engaging a hydraulic clutch interposed in each of multiple transmission paths respectively having different transmission ratios to make one of the transmission paths into transmission state is provided. The transmission ratio is set so that the minimum output rotation number of the main transmission device 10 while the auxiliary speed change device 9 is in high speed transmission state and the main transmission device 10 is in the minimum speed side transmission state is smaller than the maximum output rotation number of the main transmission device 10 while the auxiliary transmission 9 is in low speed transmission state and the main transmission 10 is in the maximum speed side transmission state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission for a working machine such as a combine, and more particularly, to a transmission system for a traveling device.
The auxiliary transmission and the main transmission are interposed in a state of being connected in series, and as the main transmission, a hydraulic clutch interposed in each of a plurality of transmission paths having different transmission ratios is selectively engaged. The present invention relates to a device provided with a device for performing one of a plurality of transmission stages by setting one of the transmission paths to a transmission state.

[0002]

2. Description of the Related Art Conventionally, in a combine as an example of a working machine, as disclosed in Japanese Patent Application Laid-Open No. H10-30720, a gear type transmission capable of shifting between high and low speeds is provided as a subtransmission. When the sub-transmission is switched to the low-speed transmission state and the sub-transmission is switched to the high-speed transmission state and the main transmission is switched to the minimum-speed transmission state, compared with the vehicle speed when the main transmission is switched to the maximum transmission state. The speed ratio (transmission ratio) of the subtransmission is set so as to increase the vehicle speed of the vehicle, and the subtransmission is switched to the low-speed transmission state, thereby performing low-speed mowing work and switching the subtransmission to the high-speed transmission state. As a result, high-speed traveling such as headland traveling was performed.

[0003]

However, in the case of the above-mentioned conventional technique, the repetition of running on a headland to a reaping place and then on a reaping work is poor in shifting operability. That is, at the time of the transition from the headland traveling to the reaping work traveling and at the time of the transition from the reaping traveling to the headland traveling,
A shift operation on the auxiliary transmission by depressing the clutch pedal is necessary, and the shift operation is complicated.

An object of the present invention is to improve shifting operability from low-speed work traveling to high-speed traveling traveling.

[0005]

The features, functions and effects of the first aspect of the present invention are as follows.

[Features] A sub-transmission and a main transmission are interposed in a power transmission system to a traveling device in a state of being connected in series,
As the main transmission, one of the transmission paths is set in a transmission state by selectively engaging and operating a hydraulic clutch interposed in each of a plurality of transmission paths having different transmission ratios, thereby performing multiple-stage shifting. Wherein the auxiliary transmission is in a low-speed transmission state and the main transmission is in a maximum-speed transmission state. The transmission ratio is set so that the minimum output speed of the main transmission when the transmission is in the high speed transmission state and the main transmission is in the lowest speed transmission state is small.

In the main transmission, the gears can be shifted to a plurality of speeds by selectively engaging the hydraulic clutch. Therefore, there is no need to operate the clutch pedal, and the hydraulic clutch is operated by operating the shift operation tool. You only need to operate it. Focusing on the above points, when according to the first invention,
When the sub-transmission is in the high-speed transmission state and the main transmission is at the lowest, the maximum output rotational speed of the main transmission when the sub-transmission is in the low-speed transmission state and the main transmission is in the highest-speed transmission state. The minimum output rotational speed of the main transmission in the high-speed transmission state is reduced, that is, when the auxiliary transmission is in a higher-speed transmission state than the maximum vehicle speed when the auxiliary transmission is in the low-speed transmission state. Since the minimum vehicle speed is reduced, when repeating a low-speed work traveling such as reaping and a high-speed traveling traveling such as a headland traveling, by switching the auxiliary transmission to a high-speed transmission state,
The shift from the low speed to the high speed can be dealt with only by the shift operation on the main transmission. On the other hand, when the work traveling such as reaping is exclusively performed, the sub transmission is switched to the low speed transmission state so that the main transmission can be shifted to the low speed transmission state. It is possible to cope with a shift for obtaining a predetermined low speed only by a shift operation on the transmission.

[Effects] Therefore, according to the first aspect of the invention, when the low-speed work traveling and the high-speed traveling traveling are repeated,
By switching the sub-transmission to the high-speed transmission state, it is possible to repeatedly perform work traveling and traveling traveling with a shift operation with good operability by operating only the shift operation tool for the main transmission, and exclusively use the work traveling In such a case, by switching the sub-transmission to the low-speed transmission state, a predetermined low-speed shift can be performed by a shift operation with good operability by operating only the shift operation tool for the main transmission. Was.

According to the second aspect of the present invention, the features, actions,
The effects are as follows.

[Features] In the features of the first invention,
The main transmission selectively shifts and operates a hydraulic clutch interposed in each of the plurality of first transmission paths having different transmission ratios, thereby setting one of the first transmission paths to the transmission state to perform a multi-stage transmission. And a hydraulic transmission clutch interposed in each of the plurality of second transmission paths having different transmission ratios is selectively engaged to operate one of the second transmission paths. A second transmission configured to perform a plurality of speed changes in a transmission state is connected in series, and a hydraulic clutch of the first transmission and a hydraulic clutch of the second transmission are connected to one transmission operation tool. It is characterized in that it is provided with a control valve for performing related control based on an operation.

According to the second aspect of the present invention, since the main transmission includes the first transmission and the second transmission connected in series, the shift of the first transmission and the shift of the second transmission are performed. A plurality of gear positions can be obtained in combination with the above. For example, when the number of gear positions of the first transmission device is two and the number of gear positions of the second transmission device is three, six 2 × 3 speeds are performed. As a result, the number of gears can be increased as compared with the number of hydraulic clutches to be installed. In other words, a smaller number of hydraulic clutches is required for the number of gears.

In addition, while being divided into a first transmission and a second transmission, a control valve is provided to control the hydraulic clutch of the first transmission and the hydraulic clutch of the second transmission based on the operation of one transmission operating tool. Since the related operation is performed, the desired good shift operability can be maintained.

[Effects] Therefore, according to the second aspect of the present invention, the number of hydraulic clutches is small for dividing the number of gears.
The shift can be performed with good operability while simplifying the structure and reducing the cost.

According to the third aspect of the present invention, the features, actions,
The effects are as follows.

[Features] In the features of the first and second aspects of the present invention, the auxiliary transmission shifts by operating a shift member based on an operation of an auxiliary transmission operating tool.

[Operation] The sub-transmission is operated to switch at the transition from work travel to travel travel or from travel to work travel. According to the third aspect of the present invention, since the auxiliary transmission is provided with a gear that is shifted by the operation of the shift member based on the operation of the auxiliary transmission operation tool, a comparison is made when the auxiliary transmission is configured in the same form as the main transmission. Thus, it is possible to reduce the cost of the subtransmission without significantly deteriorating the speed change operability.

[Effects] Therefore, according to the third aspect of the present invention, it is possible to reduce costs while maintaining good shifting operability.

According to the fourth aspect of the present invention, the features, actions,
The effects are as follows.

[Features] In the features of the first invention, the second invention, and the third invention, the sub-transmission is provided with a three-speed transmission state, a low-speed transmission state, and an ultra-low-speed transmission state at a lower speed. The point is that it can be switched to the state.

[Operation] According to the fourth aspect of the invention, the auxiliary transmission is provided with a device capable of displaying an ultra-low speed state in addition to the high-speed transmission state and the low-speed transmission state. In addition to being able to move and travel, it is possible to carry out loading and unloading at extremely low speeds using a step board to cross a ridge or to a truck bed and stably perform them.

[Effects] Therefore, according to the fourth aspect of the present invention, it is possible to conveniently carry over the ridges and unload the trucks from the loading platform.

According to the fifth aspect of the present invention, the features, functions,
The effects are as follows.

[Features] In the features of the second invention, the third invention, and the fourth invention, the first transmission is a transmission having two hydraulic clutches which can be switched between high and low, and the second transmission The device has three forward hydraulic clutches and one reverse hydraulic clutch, with three forward and one reverse
This is a transmission that can be switched between gears, and is characterized in that six hydraulic clutches are mounted on each of three transmission shafts.

[Operation] According to the fifth aspect of the present invention, the first transmission is a transmission capable of switching between high and low, and the second transmission is a second transmission.
Since the transmission is a transmission that can be switched between three forward speeds and one reverse speed, a combination of the shift of the first transmission and the shift of the second transmission enables the forward six speeds by simply installing six hydraulic clutches.・ Two reverse speeds can be changed.

Moreover, since two hydraulic clutches are mounted on each of the three transmission shafts, two hydraulic clutches are provided, and while the six hydraulic clutches are provided, the width of the installation space for the hydraulic clutches in the axial direction, that is, the hydraulic clutch The transmission case to be installed can be relatively compactly arranged in the axial direction.

[Effects] Therefore, according to the fifth aspect of the present invention, it is possible to reduce the cost by using only six hydraulic clutches, while enabling a six-speed forward shift and a two-speed reverse shift. Six hydraulic clutches are enough and two hydraulic clutches
The synergy with being mounted on the transmission shaft one by one has made it possible to make the transmission case very compact in the axial direction of the transmission case while performing six forward speeds and two reverse speeds.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a combine, which is an example of a working machine, has a cutting section 2 which cuts planted cereal culms and transports it rearward at a front portion of a traveling machine body equipped with a traveling device 1.
Are connected so as to be able to ascend and descend, and a traveling machine is equipped with a threshing device 3 for threshing the transported grain culm from the mowing unit 2 and a boarding operation unit 4.

As shown in FIG. 2, the traveling device 1 comprises a pair of left and right crawler traveling devices 1L and 1R.

The mowing unit 2 is operated by a lifting cylinder 2A using a hydraulic cylinder.

As shown in FIG. 2, of the transmission system from the engine 5 mounted on the traveling body to the crawler traveling devices 1L and 1R, the engine 5 and the crawler traveling devices 1L and 1R are included.
A main clutch 8 for interrupting transmission is interposed in a portion located between the R and the transmission case 7 supporting the axles 6L and 6R, and a sub-transmission is provided in a portion located in the transmission case 7. 9 and the main transmission 10
In the series connection state in which the left and right axles 6 of the output of the main transmission 10 are positioned on the transmission upper side.
A steering clutch / brake device 11 for turning on / off the transmission to the L and 6R is provided.

As shown in FIG. 3, the auxiliary transmission 9 includes an auxiliary transmission input shaft 13 having an input pulley 12 and an auxiliary transmission that is linked to the auxiliary transmission input shaft 13 via a pair of gears 14a and 14b. An intermediate transmission shaft 15 is provided, and the low-speed transmission gear 16L and the high-speed transmission gear 16H
And a low-speed driven gear that meshes with and operates in conjunction with the low-speed transmission gear 16L when the transmission 16 is shifted to the low-speed position when the transmission 16 is shifted to the low-speed position. When the gear 17L and the transmission 16 are shifted to the high-speed position, the high-speed driven gear 17H and the low-speed output gear 17 mesh with and operate with the high-speed transmission gear 16H.
The sub-transmission output shaft 17 provided with the sub-transmission input shaft 13 is rotatably mounted on the sub-transmission input shaft 13. That is, by shifting the transmission 16 to the low-speed position via the sub-transmission lever 9A, which is an example of the sub-transmission operation tool, the low-speed transmission gear 16
A low-speed transmission state in which the sub-transmission output shaft 17 is driven at a low speed through the high-speed output / low-speed driven gear 17L appears, and the transmission 16 is shifted to the high-speed position to be transmitted to the sub-transmission intermediate transmission shaft 15. A high-speed transmission state in which the sub-transmission output shaft 17 is driven at high speed by the power via the high-speed transmission gear 16H and the high-speed driven gear 17H appears, and by shifting the transmission body 16 to the neutral position, the sub-transmission intermediate transmission shaft 15 A neutral state in which the transmitted power is not transmitted to the sub-transmission output shaft 17 appears.

As shown in FIGS. 3 and 4, the main transmission 10 has a first transmission 18 and a second transmission 19 in the transmission system, and the first transmission 18 is located on the transmission upper side. It is configured with a series connection.

The first transmission 18 selectively engages and operates the hydraulic clutches c1 and c2, which have different transmission ratios and are respectively interposed in the two first transmission paths connected in parallel with the supply of pressure oil. With this configuration, one of the first transmission paths is set in the transmission state to perform high-low two-stage shifting. Specifically, a first speed change transmission shaft 20 is provided, and the first speed change transmission shaft 20 meshes with the low speed output gear 17a of the subtransmission device 9 to interlock with the first speed change low speed input gear 21a.
And a first-speed high-speed input gear 21b meshing with and interlocking with the high-speed output / low-speed driven gear 17L so as to freely rotate only, and the first-speed low-speed output gear 22a and the first-speed high-speed output gear 22b are integrally rotated. One hydraulic clutch c <b> 1 is provided as a low-speed clutch for mounting and disengaging low-speed transmission from the first speed-change low-speed input gear 21 a to the first speed-change transmission shaft 20, and from the first speed-change high-speed input gear 21 b to the first speed-change transmission shaft 20. The other hydraulic clutch c2 is provided as a high-speed clutch for turning on and off the high-speed transmission. That is, when the low speed clutch c1 is engaged, the first speed transmission shaft 2 is transmitted from the sub speed output shaft 17 via the low speed output gear 17a and the first speed low speed input gear 21a.
0, a low-speed transmission state in which the low-speed transmission is performed, and the high-speed clutch c2 is engaged to operate the first-speed transmission via the high-speed output / low-speed driven gear 17L and the first-speed high-speed input gear 21b from the auxiliary transmission output shaft 17. A high-speed transmission state in which transmission is performed at a higher speed than when the low-speed clutch c1 is engaged with the shaft 20 appears, and both the hydraulic clutches c1 and c2 are disengaged to operate the first transmission transmission shaft from the auxiliary transmission output shaft 17. The first transmission low-speed input gear 21a, the first transmission low-speed transmission shaft 20, and the first transmission low-speed output gear 22a form one of the first transmission paths. And the first speed high-speed input gear 21
b, first transmission shaft 20 and first high-speed output gear 22b
The other first transmission path is formed from these.

In the second transmission 19, the hydraulic clutches C1, C2, C3, and C4, which have different transmission ratios and are interposed in the four second transmission paths connected in parallel, are selectively connected to the supply of hydraulic oil. And actuate the second
The transmission is configured such that one of the transmission paths is in a transmission state, and three forward speeds and one reverse speed are performed. Specifically, a second transmission first transmission shaft 23 for the first and third forward stages and a second transmission second transmission shaft 24 for the second forward and reverse stages are provided.
A forward first input gear 25a meshing with and interlocking with the first shift low-speed output gear 22a and a third forward input gear 25c meshing with and interlocking with the first shift high-speed output gear 22b are rotatably mounted on the first shift transmission shaft. At the same time, the first output gear 26a is mounted so as to rotate integrally with the second output gear 26a.
The transmission shaft 24 has a forward second input gear 25b meshed with the first speed change high-speed output gear 22b and a reverse input gear 25d meshed with the forward first input gear 25a (the first forward input gear 25a is an idler). The first forward input gear 25a and the second forward input gear 2
5b Rotates in the direction opposite to the forward third input gear 25c. ) And the second output gear 26b are mounted so as to rotate integrally, and the second output gear 26b is mounted in an integrally rotating state, so that the forward first speed transmission from the forward first input gear 25a to the second speed first transmission shaft 23 is turned on and off. One hydraulic clutch C <b> 1 is provided as one clutch, and the second forward transmission that switches on and off the second forward transmission from the second forward input gear 25 b to the second transmission second transmission shaft 24.
Another hydraulic clutch C2 is provided as a clutch, and another hydraulic clutch C3 is provided as a third forward clutch which switches on and off a third forward transmission from the third forward input gear 25c to the second transmission first transmission shaft 23, Reverse input gear 25d
One hydraulic clutch C4 is provided as a reverse clutch for turning on and off the reverse transmission from the second transmission to the second transmission shaft 24. That is, the forward first clutch C1
, The first transmission low-speed output gear 22 a and the forward first input gear 25 from the first transmission transmission shaft 20.
a to the second transmission first transmission shaft 23 via a (low speed 1st speed)
A first forward transmission state output from the first output gear 26a is transmitted, and the second forward clutch C2 is engaged to operate the first forward transmission shaft 20 to transmit the first forward high-speed output gear 22b and the first forward high speed output gear 22b. The second through the two-input gear 25b
The second forward transmission is performed at a higher speed than when the first clutch C1 is engaged with the second transmission shaft 24, and a second forward transmission state output from the second output gear 26b appears.
When the third forward clutch C3 is engaged, the second transmission first transmission shaft 2 is transmitted from the first transmission shaft 20 via the first high-speed output gear 22b and the third forward input gear 25c.
3, the third forward transmission is performed at a higher speed than when the second forward clutch C2 is engaged, and the third forward transmission state output from the first output gear 26a is exhibited.
, The first transmission low-speed output gear 22 a and the forward first input gear 25 from the first transmission transmission shaft 20.
a to the second transmission second transmission shaft 24 via the second input gear 25d and the reverse input gear 25d, thereby to exhibit a reverse transmission state output from the second output gear 26b.
An input gear 25a, a second transmission first transmission shaft 23, and a first output gear 26a form one second transmission path, and a forward second input gear 25b, a second transmission second transmission shaft 24, and a second output gear. 26b forms another second transmission path,
Another second transmission path is formed by the third forward input gear 25c, the second transmission first transmission shaft 23, and the first output gear 26a, and the first input gear 25a, the reverse input gear 25d, and the second transmission One second transmission path remaining from the second transmission shaft 24 and the second output gear 26b is formed.

Therefore, in the main transmission 10, a combination of a two-stage high-low speed shift by the first transmission 18 and a three-speed forward and one-reverse speed shift by the second transmission 19 combines the six forward speeds and two reverse speeds. It is possible to change gears.

The deceleration transmission is set even at the highest forward six speeds. As shown in FIG. 7, the first transmission 18 is set to the low speed transmission state, and the second transmission 19 is set to the third forward transmission. The first transmission 18 is in a high-speed transmission state and the second transmission when the second transmission 19 is in a forward first transmission state is smaller than the output rotation speed of the second transmission 19 in the state.
The transmission ratio of the first transmission path and the second transmission path is set so as to increase the output rotation speed of the transmission 19. That is, the first transmission 18 is set to the low-speed transmission state and the second transmission
By setting the transmission 19 in the first forward transmission state, a first forward speed state F1 in which the output rotation is at the lowest speed appears, the first transmission 18 is set in the low speed transmission state, and the second transmission 1 is set in the first transmission state.
9 in the forward second transmission state, a second forward speed state F2 in which the output rotation is higher than that in the first forward speed state F1 appears, the first transmission 18 is brought into the low speed transmission state, and the second transmission 19 In the forward third transmission state, a third forward speed state F3 in which the output rotation is higher than in the second forward speed state F2 appears, the first transmission 18 is brought into the high-speed transmission state, and the second transmission 19 is brought into operation. By setting the first forward transmission state, a fourth forward state F4 in which the output rotation is higher than in the third forward state F3 appears, the first transmission 18 is set to the high-speed transmission state, and the second transmission 19 is moved forward. By setting the second transmission state, a fifth forward speed state F5 in which the output rotation is higher than in the fourth forward speed state F4 appears, the first transmission device 18 is set to the high speed transmission state, and the second transmission device 19 is set to the forward second speed state. 3 By setting the transmission state A sixth forward speed state F6, in which the output rotation is higher than the fifth forward speed state F5, appears, and the first transmission 18 is set to the low speed transmission state, and the second transmission 19 is set to the reverse transmission state, thereby setting the reverse low speed state. RL, the first transmission 18 is brought into a high-speed transmission state, and the second transmission 1
9 is set in a reverse transmission state, whereby a reverse high speed state RH in which the output rotation is higher than that in the reverse low speed state RL appears.
By setting the first transmission 18 to a neutral state where both hydraulic clutches c1 and c2 are disengaged, and setting the second transmission 19 to a neutral state where all the hydraulic clutches C1, C2, C3 and C4 are disengaged. , A neutral state N in which no transmission is performed.

As shown in FIG. 7, the maximum output rotational speed of the main transmission 10 is lower than when the sub-transmission 9 is in the low-speed transmission state and the main transmission 10 is in the highest-speed transmission state. The transmission ratio of the auxiliary transmission 9 is set so as to reduce the minimum output rotation speed of the main transmission 10 when the auxiliary transmission 9 is in the high-speed transmission state and in the transmission state on the lowest speed side of the main transmission 10. I have. Specifically, the auxiliary transmission 9
Is substantially equal to the vehicle speed when the main transmission 10 is in the fourth forward speed state and the vehicle speed when the auxiliary transmission 9 is in the high speed transmission state and the main transmission 10 is in the first forward speed state. The vehicle speed when the subtransmission 9 is in the low speed transmission state and the main transmission 10 is in the fifth forward speed state, the subtransmission 9 is in the high speed transmission state, and the main transmission 1
0 makes the vehicle speed in the second forward speed state substantially equal to the vehicle speed when the auxiliary transmission 9 is in the low speed transmission state and the main transmission 10 is in the sixth forward speed state, and the sub transmission 9 is in the high speed transmission state. In this state, the vehicle speed is set to be substantially equal to the vehicle speed when the main transmission 10 is in the third forward speed state.

As shown in FIG. 4, a disc clearance δ1, which is a clearance between the disc P and the piston P between the high speed clutch c2 of the first transmission 18 and the forward first clutch C1 of the second transmission 19, is increased. Other hydraulic clutch c
The disc clearance δ2, which is the gap between the piston P of each of C1, C2, C3, and C4 and the disc D, is set smaller.

As shown in FIG. 3, the steering clutch brake device 11 includes a first output gear 2 of a second transmission 19.
A transmission shaft 28 interlocked with the second output gear 26a and the second output gear 26b via a gear 27 is provided.
Input gears 29L, 2 attached integrally to L, 6R
Transmission gears 30L, 3 meshing with and interlocking with the respective 9Rs
OR are independently rotatable and shiftably mounted. When the transmission gears 30L, 30R are shifted to the first position, the transmission gears 30L, 30R are respectively linked to the transmission shaft 28 and the transmission gears 30L, 30R are connected to the second gear. The transmission shaft 28 of the transmission gears 30L, 30R when shifting to the shift position
And left and right steering clutches 31L and 31R using a claw clutch for interrupting transmission to the steering clutches 31L and 31R, respectively.
When the transmission gears 30L and 30R shift from the second position to the side opposite to the first position in a state where the first gear 1R is turned off, the transmission gears 30L and 30R gradually increase the braking force.
Left and right springs 33 for biasing each of the transmission gears 30L, 30R to a first position are provided with multi-plate type steering brakes 32L, 32R for braking the respective L, 30R.
L, 33R, and transmission gears 30L, 3
The internal hydraulic cylinders 34L and 34R that shift by moving each of the 0Rs from the first position to the braking position against the urging force are provided. That is, the transmission gears 30L and 30R are shifted to the first position by the urging force of the springs 33L and 33R by the oil discharged from the hydraulic cylinders 34L and 34R, and the steering clutches 31L and 31R are engaged to operate the gear 27 and the transmission. The output of the main transmission 10 is transmitted to the axles 6L and 6R via the shaft 28 and the steering clutches 31L and 31R, and the hydraulic cylinders 34L and 34R are transmitted.
The main gear is shifted by shifting the transmission gears 30L, 30R to the second position against the urging force by the hydraulic oil supply for making the supply pressure to the R the first set pressure, and disengaging the steering clutches 31L, 31R. The transmission of the output of the device 10 to the axles 6L, 6R is cut off, and the transmission gears 30L, 30R are further supplied with pressure oil for causing the supply pressure to the hydraulic cylinders 34L, 34R to a second set pressure larger than the first set pressure. The axles 6L, 6R are braked by shifting to the braking position against the urging force and braking the steering brakes 32L, 32R with the steering clutches 31L, 31R disengaged. Accordingly, the left and right steering clutches 31L, 31R are both engaged and actuated, so that the output of the main transmission 10 is transmitted at a constant speed to the left and right crawler traveling devices 1L, 1R to drive the left and right crawler traveling devices 1L, 1R. You can go straight ahead,
By turning off the steering clutch 31L or 31R inside the turning, transmission to the crawler running device 1L or 1R inside the turning is cut off, and the crawler running device 1 inside the turning is cut off.
By turning off the L or 1R and performing only gentle turning by driving only the crawler traveling device 1R or 1L on the outer side of the turn, the steering brake 32L or 32R on the inner side of the turn is braked to operate the crawler traveling device on the inner side of the turn. 1L or 1
The transmission to the R is turned off, and the crawler traveling device 1L inside the turn is turned off.
Alternatively, it is possible to perform a sharp turn by braking only the 1R and driving only the crawler traveling device 1R or 1L outside the turn.

The steering clutch brake device 11
, One of the steering brakes 32L or 32R (shown by the right steering brake 32R in the figure) is used as the cam mechanism 35a.
And a brake lever 35 for performing a braking operation via the brake lever. That is, in the parking state in which the traveling is stopped, the brake lever 35 is operated in a state where the steering clutches 30L and 30R are engaged and operated, and one of the steering brakes 32L or 32L is operated.
By performing the braking operation on R, the braking force can be applied to the other crawler traveling device 1R or 1L via the transmission shaft 28, and the one steering brake 32L or 32
R functions as a parking brake.

As shown in FIG. 5, the operating device of the main transmission 10 is provided with a shift lever 36, which is one shift operating tool, and receives hydraulic clutches c1, c2, C1, A control valve 39 using a rotary valve for controlling the hydraulic clutches c1, c2, C1, C2, C3 and C4 based on the operation of the shift lever 36 is provided in a hydraulic supply path 38 to C2, C3 and C4. Have been. That is, as shown in FIG. 6, the control valve 39 is interlocked with the operation lever 36 via the gears 40 and 41, and when the shift lever 36 is operated to the forward first speed position f1, the low speed clutch c1 and the forward clutch When the transmission is switched to the first forward speed state F1 in which pressure oil is supplied to the first clutch C1 and the shift lever 36 is operated to the second forward speed position f2, forward movement in which pressure oil is supplied to the low speed clutch c1 and the forward second clutch C2. The state is switched to the second speed state F2, and the shift lever 36 moves forward 3
When operated to the speed position f3, the third forward speed state F3 in which hydraulic oil is supplied to the low speed clutch c1 and the third forward clutch C3
When the speed change lever 36 is operated to the fourth forward speed position f4, the shift lever 36 is switched to the fourth forward speed state F4 in which pressure oil is supplied to the high speed clutch c2 and the first forward clutch C1,
When the shift lever 36 is operated to the forward fifth speed position f5,
The state is switched to the forward fifth speed state F5 in which pressure oil is supplied to the high-speed clutch c2 and the forward second clutch C2, and the speed change lever 36
Is operated to the forward sixth speed position f6, the high speed clutch c
When the transmission is switched to the sixth forward speed state F6 in which pressure oil is supplied to the second and third forward clutches C3 and the shift lever 36 is operated to the reverse low speed position rL, the reverse drive for supplying hydraulic oil to the low speed clutch c1 and the reverse clutch C4 When the transmission is switched to the low speed state RL and the shift lever 36 is operated to the reverse high speed position rH, the operation is switched to the reverse high speed state RH in which pressure oil is supplied to the high speed clutch c2 and the reverse clutch C4.

In the operating device, the second time required for the hydraulic clutches c1 and c2 of the first transmission 18 to enter and operate in accordance with the supply of the pressure oil based on the operation of the control valve 39 is determined by the operation time of the control valve 39. Transmission 1 based on pressure oil supply based on
9 is set shorter than the first time required for the hydraulic clutches C1, C2, C3, and C4 to engage and operate. The setting means includes the hydraulic clutches c1 and c2 of the first transmission 18.
Means for delaying the supply of hydraulic oil to the hydraulic clutches C1, C2, C3, C4 of the second transmission 19 with respect to the supply of hydraulic oil to the second transmission 19, so that the second time is shorter than the first time It is.

A pressure reducing valve 43 for setting a clutch pressure is interposed in the hydraulic pressure supply path 38. The brake oil is supplied by the hydraulic pump 37 and the brake lever 44 is pressed against the bias by a brake spring 44. A brake release hydraulic cylinder 45 for releasing the brake 35 is connected.
In other words, the steering brake 32L or 3 serving as the parking brake
The 2R is configured as a negative brake that automatically performs a braking operation when the engine is stopped. In addition, the hydraulic supply channel 3
8, the supply path portion for the low-speed clutch c1 includes:
A check valve 38a and a throttle 38b for reducing the operating speed associated with oil drainage while maintaining the operating speed associated with the supply of pressure oil to the low-speed clutch c1 at a set value are interposed in a state of being connected in parallel. That is, when shifting from the third forward speed state F3 to a higher speed state (fourth forward speed state F4, fifth forward speed state F5, sixth forward speed state), and shifting from the reverse low speed state RL to the reverse high speed state RH. At times, the time during which the low-speed clutch c1 is engaged is as long as possible to prevent the vehicle speed from extremely lowering due to the running resistance, thereby reducing the difference in vehicle speed and causing a high-speed state with less shock. And a transition to the reverse high speed state RH. A hydraulic pressure supply line 46 for steering to the hydraulic cylinders 34L, 34R of the steering clutch brake device 11 is branched and connected to the hydraulic pressure supply line 38. A steering valve 48a for controlling the hydraulic cylinders 34L and 34R based on an operation of a steering lever 47, which is a steering operation tool, and a supply pressure adjusting valve 48b are interposed. That is, when the steering lever 47 is located at the neutral position N in the straight running state, the steering valve 48a is switched to the straight running state S in which the hydraulic oil is not supplied to the hydraulic cylinders 34L, 34R, so that the left and right steering clutches 31L, 3L are switched.
When the steering lever 47 is located at the gentle left turn position L1, the steering valve 4 is turned on.
8a is switched to the left turning state TL for supplying hydraulic oil to the left hydraulic cylinder 34L, and the supply pressure adjusting valve 48b is set to the first
By switching to the set pressure state, the left steering clutch 31L is disengaged to produce a gentle left turning state. When the steering lever 47 is located at the gentle right turning position R1, the steering valve 48a is moved to the right. By switching to the right turning state TR for supplying the hydraulic oil to the hydraulic cylinder 34R and switching the supply pressure regulating valve 48b to the first set pressure state, the right steering clutch 31R is disengaged to operate the right gentle turning state. When the steering lever 47 is located at the sharp left turning position L2, the steering valve 48a is switched to a left turning state in which hydraulic oil is supplied to the left hydraulic cylinder 34L and the supply pressure adjusting valve 48b is set to the second turning state.
By switching to the set pressure state, the left steering clutch 31L is disengaged and the left steering brake 32L is operated.
When the steering lever 47 is located at the sharp right turning position R2, the steering valve 48 is activated.
a to the right hydraulic cylinder 34R and to the right turning clutch 31R by switching the supply pressure regulating valve 48b to the second set pressure state.
Is turned off, and the right steering brake 32R is operated to perform a braking operation, thereby producing a sharply turning right state. Further, a second hydraulic pump 49 driven by the engine 5
The hydraulic oil supply path 50 for raising and lowering to the lifting cylinder 2A from
An elevating valve 52 for controlling the elevating cylinder 2A based on the operation of the elevating operation tool 51 is provided, and the hydraulic clutches c1 and c2 of the first transmission 18 and the second transmission 19
The lubricating oil supply passage 53 that supplies hydraulic oil as lubricating oil is connected to the hydraulic clutches C1, C2, C3, and C4.
The elevating operation tool 51 and the steering lever 47 are constituted by a single operation lever.

The means for driving the reaping unit 2 comprises:
A means for transmitting the output of the first transmission 18 to the reaping unit 2, specifically, a reaping output shaft 55 having an output pulley 54 to the reaping unit 2 is driven by a first transmission low-speed output gear 22 a They are linked via 56.

[Alternative Embodiment] In the above embodiment, the auxiliary transmission 9 is provided so as to be freely switchable between a low-speed transmission state and a high-speed transmission state. However, the auxiliary transmission 9 is shown in FIG. As shown in FIG.
6U, and an ultra-low speed driven gear 17U, which meshes with and interlocks with the ultra-low speed transmission gear 16U when the transmission body 16 is shifted to the ultra-low speed position, is provided on the sub-transmission output shaft 17 to switch between the low-speed transmission state and the high-speed transmission state. In addition, ultra low speed transmission gear 1
It may be configured such that an ultra-low speed transmission state in which the sub-transmission output shaft 17 is driven at an extremely low speed lower than the low speed transmission state by the interlocking engagement between the 6U and the ultra low speed driven gear 17U.

In the above-described embodiment, the main transmission 10 has a forward 6-speed and a reverse 2-speed consisting of two transmissions 18 and 19 connected in series. It may be composed of a multi-stage transmission.

In the above-described embodiment, the hydraulic clutch of the main transmission 10 has been described as being operated by supplying hydraulic oil. However, the hydraulic clutch is configured to be activated by the force of a spring as oil is drained. May be.

[Brief description of the drawings]

FIG. 1 is a side view of a combine.

FIG. 2 is a transmission system diagram from an engine to a traveling device.

FIG. 3 is a schematic longitudinal side view of the transmission.

FIG. 4 is a longitudinal sectional view of the transmission.

FIG. 5 is a hydraulic circuit diagram

FIG. 6 is a side view of a shift lever.

FIG. 7 is a graph showing a relationship between a shift state and a vehicle speed.

FIG. 8 is a transmission system diagram showing another embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 traveling device 9 auxiliary transmission device 9A auxiliary transmission operation device 10 main transmission device 16 shift member 18 first transmission device 19 second transmission device 20 transmission shaft 23 transmission shaft 24 transmission shaft 36 transmission operation device 39 control valve c1 hydraulic clutch c2 hydraulic pressure Clutch C1 Hydraulic clutch C2 Hydraulic clutch C3 Hydraulic clutch C4 Hydraulic clutch

Claims (5)

[Claims] An auxiliary transmission and a main transmission are interposed in a transmission system to a traveling device in a state where the auxiliary transmission and a main transmission are connected in series. As the main transmission, each of a plurality of transmission paths having different transmission ratios is provided. A transmission for a working machine, wherein one of the transmission paths is set in a transmission state by selectively engaging and operating a hydraulic clutch interposed in the transmission gear to perform a plurality of speed changes, wherein the auxiliary transmission Are in the low-speed transmission state and the main transmission is in the transmission state on the highest speed side, the auxiliary transmission is in the high-speed transmission state and the main transmission is A transmission for a working machine in which a transmission ratio is set such that a minimum output rotation speed of a main transmission in a transmission state is reduced. 2. The transmission according to claim 1, wherein one of the first transmission paths is set in a transmission state by selectively engaging and operating a hydraulic clutch interposed in each of the plurality of first transmission paths having different transmission ratios. The second transmission is performed by selectively engaging and operating a first transmission that is configured to perform a plurality of gear shifts and a plurality of second transmission paths that are different from each other in transmission ratio. A second transmission configured to perform a plurality of speed changes with one of the paths in a transmission state is connected in series, and a hydraulic clutch of the first transmission and a hydraulic clutch of the second transmission are connected to each other. The transmission of a work machine according to claim 1, further comprising a control valve for performing related control based on an operation of the two shift operation tools. 3. The transmission of a working machine according to claim 1, wherein the auxiliary transmission changes the speed by operating a shift member based on an operation of the auxiliary transmission operation tool. 4. The sub-transmission according to claim 1, wherein the sub-transmission is switchable between three states: a high-speed transmission state, a low-speed transmission state, and an ultra-low-speed transmission state at a lower speed. Work machine transmission. 5. The first transmission is a two-stage switchable transmission having two hydraulic clutches, and the second transmission has three forward hydraulic clutches and one reverse hydraulic clutch. The transmission according to any one of claims 2 to 4, wherein the transmission is capable of switching between three forward speeds and one reverse speed, and two hydraulic clutches are mounted on each of the three transmission shafts. Transmission of the machine.