JP3495127B2 - Work vehicle traveling speed change structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling speed change structure for a work vehicle.

[0002]

2. Description of the Related Art There are some work vehicles in which a main transmission capable of shifting in a plurality of stages and a sub transmission capable of shifting in two high and low stages are arranged in series for traveling. In this case, the main transmission and the auxiliary transmission are configured to be independently shiftable by a shift lever (corresponding to the first and second manual operation tools) or the like.

[0003]

When the main transmission and the auxiliary transmission as described above are equipped, for example, as shown in FIG. 1, the main transmission is capable of shifting to eight speeds and the auxiliary transmission has two high and low speeds. It is assumed that the vehicle is configured to be shiftable. As a result, the traveling system has a total of the 1st to 8th gear shift positions of the main transmission at the low speed position of the auxiliary transmission and the 1st to 8th gear shift positions of the main transmission at the high speed position of the auxiliary transmission. It becomes possible to shift to 16 steps.

For example, as shown in FIG. 11, in a state in which the auxiliary transmission is shifted to the low speed position and the main transmission is shifted to the fifth speed shift position, for example, the auxiliary transmission is shifted from the low speed position to the high speed position. Suppose In this case, since the main transmission remains in the 5th speed shift position regardless of the shift operation of the auxiliary transmission, the 5th speed shift position in the low speed position (the 5th speed position in the travel system) ), The gear shift operation is performed to the 5th speed shift position at the high speed position (the 13th speed position as the traveling system) (for example, if the traveling speed at the 5th speed position is 0.59 km / h, the 13th speed is set). The running speed at the position is 5.80 km / h). On the contrary, when the auxiliary transmission is shifted to the high speed position and the main transmission is shifted to the fifth speed position, for example, when the auxiliary transmission is shifted from the high speed position to the low speed position, the shift operation of the auxiliary transmission is performed. Since the main transmission remains in the 5th gear position regardless of the above, the traveling system shifts from the 5th gear position at the high speed position (13th gear position as the traveling system) to the 5th gear position at the low speed position. The gear shift operation is performed to the gear shift position (5th gear position as a traveling system).

As described above, when the shift position of the traveling system is largely changed when the auxiliary transmission is operated to shift (FIG. 1).
Since there are the 5th speed position and the 13th speed position shown in 1), the traveling speed of the airframe may change greatly with this and shock may occur, and there is room for improvement in ride comfort. The present invention relates to a traveling speed change structure for a work vehicle in which a main speed changer capable of shifting a plurality of speeds for traveling and a sub speed changer capable of shifting to two high and low speeds are arranged in series. The purpose is to improve comfort.

[0006]

The feature of the present invention resides in that the traveling speed change structure for a work vehicle as described above is configured as follows. [1] A first manual operation tool based on a first artificial operation tool that is manually operated by arranging a main transmission apparatus capable of shifting in a plurality of stages and an auxiliary transmission apparatus capable of shifting in two high and low stages in series. The first manual operation tool is provided with the speed change control means for changing the speed of the main transmission device to the speed change position corresponding to When the sub-transmission is shifted from the low speed position to the high speed position by the second manipulating tool while the main transmission is being shifted to a certain shift position by Also, the first transmission means for automatically shifting the main transmission in preference to the shift control means so that the shift position is on the low speed side, and the shift operation to the shift position where the main transmission is located by the first manual operation tool. Second, while being
When the auxiliary transmission is operated to shift from the high speed position to the low speed position by the manual operation tool, the main control unit takes precedence over the shift control unit so that the auxiliary transmission is at a higher speed side than the shift position of the main transmission before the shift operation. A second speed change means for automatically changing the speed of the speed change device;
Shifted from stationary or high speed position to neutral stop position
At the first, the main transmission is operated by the first manipulator
Then, after the gear shifting operation by the first manual operation tool,
Auxiliary transmission is in low speed position and high speed position due to human operation
Even if the gear shift operation is performed, the first and second gear shifting means take precedence.
After the gear shift operation by the first human-operated operation tool at the neutral stop position,
Auxiliary shift control means for maintaining the main transmission in the shift position
It is prepared.

[2] In the configuration of [1] above, the second
When the auxiliary transmission is shifted from the low speed position to the neutral stop position by the manual operation tool and is again shifted to the low speed position, the first transmission restraining means that leaves the main transmission at the shift position before the shift operation and the second artificial restraint means. When the auxiliary transmission device is operated to shift from the high speed position to the neutral stop position by the operating tool and then to the high speed position again, there is provided second restraining means for leaving the main transmission device at the shift position before the speed changing operation.

[0008]

[0009]

[I] For example, as shown in FIGS. 1 and 10, the main transmissions 10 and 11 are configured to be capable of shifting to eight speeds, and the auxiliary transmission 12 is configured to be capable of shifting to high and low speeds. It is assumed that the gear is configured to be capable of shifting to 16 speeds. in this case,
When configured as in the previous section [1], for example, the solid line A in FIG.
As shown by A and A2, the first manual operation tool shifts the main transmissions 10 and 11 to the 5th speed shift position, and the second manual operation tool shifts the auxiliary transmission 12 to the low speed position L. Suppose (5th speed position as a running system). In this state, the auxiliary transmission 12 is moved to the low speed position L by the second manual operation tool.
From the high speed position H to the main transmission 10, 1
1 is automatically shifted to a shift position lower than the shift position of 5th speed (for example, when shifting to the shift position of 1st speed, the shift position becomes 9th position as a traveling system).

As a result, a shift position (5th gear position shown in FIG. 10) as a traveling system before the shift operation of the auxiliary transmission and a shift position (9th gear position shown in FIG. 10) as a traveling system after the shift operation are performed. Is smaller than that in the conventional configuration (the position from the fifth speed position to the thirteenth speed position shown in FIG. 11), and the change in the traveling speed of the airframe due to this is also small. (For example, when the traveling speed at the fifth speed position is 0.59 km / h, the traveling speed at the thirteenth speed position is 5.80 km / h,
9 when the traveling speed at the 5th speed position is 0.59 km / h
The traveling speed in the high speed position is 1.90 km / h).

On the contrary, in FIG. 10, the first manual operation tool shifts the main transmissions 10 and 11 to the 5th speed shift position, and the second manual operation tool shifts the auxiliary transmission 12 to the high speed position H.
In the state of shifting gears (13th speed position as a running system),
When the second manual operation tool shifts the auxiliary transmission 12 from the high speed position H to the low speed position L, the main transmissions 10 and 11 are automatically shifted to a speed higher than the fifth speed. (For example, if you shift to the 8th gear position,
It becomes the 8th speed position as a running system). As a result, the difference between the shift position as the traveling system before the shift operation of the auxiliary transmission (13th speed position shown in FIG. 10) and the shift position as the traveling system after the shift operation (8th speed position shown in FIG. 10) is The size is smaller than that of the conventional configuration (the position from the 13th speed to the 5th speed shown in FIG. 11), and the change in the traveling speed of the airframe accompanying this is also small.

Further , the auxiliary transmission device is operated by the second manipulating tool.
Shifts from the low speed position or the high speed position to the neutral stop position.
The main transmission in the
When the gear shift operation is performed, the gear shift operation by the first artificial operation tool
Afterwards, the auxiliary transmission is set to the low speed position and
Even if the gear is operated to a high speed position, the first and second gear shifting means
Priority is given to shifting by the first manipulator at the neutral stop position
Auxiliary shift control that keeps the main transmission in the shift position after operation
Since it is provided with the means, it has the following effects. Figure 1
As indicated by the solid line A1 of 0 and the dashed line A4,
Move the main transmissions 10 and 11 to the 5th gear shift position with the operation tool.
Change the speed and lower the auxiliary transmission 12 by the second manipulator.
In the state where gear shifting operation is performed to the high speed position L (or the high speed position H).
Then, the auxiliary transmission 12 is neutrally stopped by the second manipulating tool.
It is assumed that the gear is changed to the stop position N. Next, the sub transmission 12
At the neutral stop position N of the
Change the speed device from, for example, the 5th gear position to the 3rd gear position.
When operated at high speed, after this, a secondary change is made by the second artificial operation tool.
Shift the speed device 12 from the neutral stop position N to the high speed position H.
Even if it is made, the main transmission 1
0 and 11 are gear shift positions after the gear shift operation by the first manual operation tool.
(3rd speed shift position shown in FIG. 10) is maintained.

As described above, the actual shift operation of the auxiliary transmission device is performed.
Work (from low speed position to high speed position or from high speed position)
Even if a gear change operation to a low speed position is performed,
Even if the actual shifting operation is not performed
At the stop position N, the operator shifts the main gear by the first manual operation tool.
When the device is operated to shift gears, this operator's intention
Respected, the main transmission is the first manipulator
Since it is maintained in the shift position after the work, it is uncomfortable for the worker.
I have no feeling.

[0014] With the configuration as (II) set forth in the preceding paragraph (2), provided with a "working" according to the above [1] items [I] As with the configuration of, the following in addition to It has "action". With the configuration of the above [2], for example, as shown by the solid line A1 and the alternate long and short dash line A3 in FIG. 10, the main transmissions 10 and 11 are shifted to the 5th speed shift position by the first manipulating implement, and the second manipulating device is operated. While the sub-transmission device 12 is being shifted to the low speed position L by the operation tool, the sub-transmission device 12 is operated by the second manual operation tool at the low speed position L.
From the neutral stop position N to the low speed position L again. In this case, the automatic transmission operation of the main transmissions 10 and 11 is not performed, and the main transmissions 10 and 11 are left at the 5th gear shift position, which is the gear shift position of the auxiliary transmission 12 before the gear shift operation.

[0015] Conversely, the main transmission by a first manual control device 1
In a state in which 0 and 11 are gear-shifted to the 5th gear shift position, and the auxiliary gearbox 12 is gearshifted to the high-speed position H by the second manipulator, the second gearshift device 12 is operated by the second manipulator.
It is assumed that the gear shift operation is performed from the high speed position H to the neutral stop position N and then to the high speed position H again. In this case, the automatic transmission operation of the main transmissions 10 and 11 is not performed, and the main transmissions 10 and 11 are left at the 5th gear shift position, which is the gear shift position of the auxiliary transmission 12 before the gear shift operation.

As described above, when the second manual operation tool starts shifting the auxiliary transmission and returns it to the original shifting position, the automatic shifting of the main transmission is not performed and the main shifting is not performed. The device is left in its original gear position. Thus, the operator does not actually shift the auxiliary transmission, but the operator does not feel uncomfortable due to an unnecessary change in the shift position of the main transmission.

[0017]

According to the first aspect of the present invention, there is provided a traveling speed change structure for a working vehicle in which a main speed changer capable of shifting a plurality of speeds for traveling and a sub speed changer capable of shifting to two high and low speeds are arranged in series. By automatically changing the speed of the main transmission so that the shift position of the traveling system does not change significantly due to the shift operation of the auxiliary transmission, the change in the traveling speed of the aircraft before and after the shift operation of the auxiliary transmission and I was able to reduce the shock and improve the riding comfort of the work vehicle.

At the neutral stop position of the auxiliary transmission,
When an operator shifts the main transmission,
The intention of high speed operation is respected, and the main transmission is operated first
The gear position is maintained after the gear shift operation,
The feeling of discomfort for workers is suppressed, and the operation feeling of the work vehicle is low.
I was able to prevent the bottom.

According to the second aspect, similar to the case of the first aspect, the above-mentioned "effect of the invention" is provided. According to the second aspect of the present invention, when the auxiliary transmission is started to shift and then returned to the original shift position, the main transmission is left in the original shift position. It was possible to prevent the operator from feeling uncomfortable due to the necessary gear shift operation and prevent the deterioration of the operation feeling of the work vehicle.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. (1) FIG. 1 shows the inside of a mission case 8 of a four-wheel drive type agricultural tractor, which is an example of a work vehicle. Power from an engine 1 is transmitted via a transmission shaft 2 and a hydraulic multi-plate PTO clutch 3. It is transmitted to the PTO shaft 4. The power from the engine 1 is the forward clutch 5 or the reverse clutch 6, the cylindrical shaft 7, the first main transmission device 10 (corresponding to the main transmission device), the second main transmission device 11 (corresponding to the main transmission device), and the auxiliary transmission device 12. ,
And transmitted to the left and right rear wheels 14 via the rear wheel differential device 13. The power branched from immediately before the rear wheel differential device 13 is transmitted through the transmission shaft 15, the hydraulic clutch type front wheel transmission device 16, the front wheel transmission shaft 17, and the front wheel differential device 18 to the left and right front wheels 19.
Be transmitted to.

The forward clutch 5 and the reverse clutch 6 are hydraulic multi-plate type in which a friction plate (not shown) and a piston (not shown) are combined, and are operated to the transmission side by supplying hydraulic oil. When the forward clutch 5 is operated to the transmission side,
The power of the engine 1 directly flows from the forward clutch 5 to the cylindrical shaft 7, and the vehicle body moves forward. When the reverse clutch 6 is operated to the transmission side, the power of the engine 1 is transmitted to the cylindrical shaft 7 in the reverse rotation state via the reverse clutch 6 and the transmission shaft 20, and the machine body moves backward.

The first main transmission 10 comprises four hydraulic multi-disc type first speed clutches 21, second speed clutches 22 and third speed clutches 2.
It is configured as a hydraulic clutch type in which the 3rd and 4th speed clutches 24 are arranged in parallel and is capable of shifting to 4 speeds. By operating one of the 1st speed to 4th speed clutches 21 to 24 to the transmission side, The power from the cylindrical shaft 7 on the engine 1 side is subjected to a four-speed gear shift operation and transmitted to the lower transmission shaft 25.

The second main transmission 11 is also of a hydraulic clutch type in which two hydraulic multi-plate low speed clutches 26 and high speed clutches 27 are arranged in parallel, and one of the low speed and high speed clutches 26, 27 is transmitted. By operating to the side, the power from the transmission shaft 25 on the side of the first main transmission 10 is reduced to 2
The shift operation is performed in steps and is transmitted to the auxiliary transmission device 12 on the lower side. The sub-transmission device 12 is of a synchromesh type in which the shift member 53 is slidably operated, and is capable of shifting in two stages, and is mechanically shifted by a shift lever 28 (corresponding to a second manual operation tool) described later.

(2) Next, the forward and reverse clutches 5,
6, the hydraulic circuit for the first and second main transmissions 10, 11, etc. will be described. As shown in FIG. 3, in the oil passage 30 from the pump 29, an electromagnetic proportional valve 35 for the forward and backward clutches 5, 6 and pilot operated switching valves 36a, 37 are provided.
a, first to fourth speed clutches 21 to 2 of the first main transmission device 10
4, pilot operated switching valves 31a, 32a,
33a, 34a and electromagnetic proportional valves 38, 39 for the low speed and high speed clutches 26, 27 of the second main transmission device 11 are connected in parallel.

An oil passage 40 branched from the oil passage 30 is provided with an oil pressure clutch 4 for differential lock operation in the front wheel differential device 18.
1, a pilot operated switching valve 42a, a hydraulic clutch 43 for differential lock operation in the rear wheel differential device 13
To the pilot operated switching valve 44a, the standard clutch 45 and the speed increasing clutch 46 of the front wheel transmission 16 (see FIG. 1).
(See the reference), pilot operated switching valves 47a, 48
a is connected in parallel. Each switching valve 31a-34
a, 36a, 37a, 42a, 44a, 47a, 48a
Is urged toward the oil discharge side (transmission cutoff side) by a spring, and is operated to the supply side (transmission side) by supplying pilot hydraulic oil as described later.

A pilot oil passage 50 is branched from the oil passage 30 via a pressure reducing valve 49, and this pilot oil passage 50 is connected to the switching valves 31a to 34a, 36a, 37a, 42a, 44a.
47a, 48a are connected to the operation parts, and the operation parts have electromagnetically operated valves 31b, 32b, 33b, 34b, 36b,
37b, 42b, 44b, 47b, 48b are connected. Each solenoid operated valve 31b-34b, 36b, 37b,
42b, 44b, 47b, 48b are urged toward the oil discharge side (transmission cutoff side) by springs, and when these are electrically operated to the supply side, the pilot operating oil causes the switching valves 31a to 34b.
a, 36a, 37a, 42a, 44a, 47a, 48a
Are supplied to the operation unit of the above, and these are operated to the supply side (transmission side).

(3) Next, the forward and reverse clutches 5,
6, the configuration of the operation unit of the first and second main transmissions 10, 11 and the like will be described. As shown in FIG. 2 and FIG. 3, an opening / closing valve 51 capable of draining pilot working oil from the operating portions of the switching valves 36a, 37a of the forward and reverse clutches 5, 6 is provided, and the opening / closing valve 51 is closed by a spring. The on-off valve 5
A clutch pedal 52 for mechanically operating 1 to the open side is provided. A forward / backward lever 59 for transmitting an electric forward signal and a backward signal to the base of the steering handle 58 for the front wheel 19.
Is equipped with.

As shown in FIG. 2, the gear shift lever 28 is swingably supported around the horizontal axis of the control section of the machine body, and the shift member 53 of the auxiliary transmission 12 (see FIG. 1) is slid. The shift fork 54 and the speed change lever 28 are mechanically interlocked by a linkage mechanism 55, and the speed change lever 28 is connected to the neutral stop position N, the low speed position L, and the high speed position H.
The sub-transmission device 12 is operated to shift gears by operating the three positions. A pair of limit switches 9 for detecting that the speed change lever 28 is operated to the low speed position L and the high speed position H is provided.

A lock pin 56 which is movable up and down is provided on a lateral side portion of the speed change lever 28, and an operation button 57 for moving the lock pin 56 up and down is provided at an upper portion of the speed change lever 28. The lock pin 56 is a spring (not shown)
Is urged to move to a fixed position above the paper surface (the operation button 57 is also urged to the protruding side on the left side of the paper surface), and the lock pin 56 is engaged with the fixed guide plate 60. Causes the gear shift lever 28 to move to the neutral stop position N,
It is held at each of the low speed position L and the high speed position H. When the operation button 57 is pushed, the lock pin 56 is moved to the holding release position below the paper surface, and the gear shift lever 28 can be operated to the neutral stop position N, the low speed position L and the high speed position H.

A shift-up button 61 (corresponding to a first artificial operating tool) and a shift-down button 62 (corresponding to a first artificial operating tool) are vertically arranged on the left lateral surface of the speed change lever 28, which will be described later. When the shift-up button 61 and the shift-down button 62 are pressed once as described above, one shift-up signal and one shift-down signal are transmitted, and the shift operation of the first and second main transmissions 10 and 11 shown in FIG. 1 is performed. Done.

As shown in FIG. 2, a 7-segment shift display portion 64 for displaying the shift positions (1st to 8th speeds) of the first and second main transmissions 10 and 11, and a forward / backward movement by a forward / reverse lever 59. A forward lamp 65 and a reverse lamp 6 which indicate which one of the clutches 5 and 6 is operated to the transmission side.
6. A neutral stop lamp 67 indicating that the shift lever 28 is operated to the neutral stop position N is provided in the control section. As shown in FIG. 3, a pressure sensor 74 is provided for detecting whether or not the operating pressures of the forward and reverse clutches 5, 6 have reached a predetermined pressure in the transmission state.
The forward and reverse lamps 65 and 66 are turned on by the detection of 4.

(4) Next, the shift operation by the shift up button 61 and the shift down button 62 of the shift lever 28 will be described with reference to FIG. When the forward / backward lever 59 shown in FIG. 2 is operated to the forward position F (step S1), an operation current is supplied to the electromagnetic operation valve 36b shown in FIG. 3 (step S2), and the switching valve 36a is operated to the supply side. Then, the forward clutch 5 is operated to the transmission side, and the forward lamp 65 is turned on (step S3). Conversely, if the forward / reverse lever 59 is operated to the reverse position R (step S
1), an operation current is supplied to the electromagnetic operation valve 37b shown in FIG. 3 (step S4), the switching valve 37a is operated to the supply side, the reverse clutch 6 is operated to the transmission side, and the reverse lamp 66 is operated.
Lights up (step S5), and the buzzer 71 shown in FIG. 2 operates intermittently (step S6).

As shown in FIG. 1, the first main transmission 10 has four
Since the second main transmission device 11 can shift to two speeds, the first and second main transmission devices 10 and 11 can shift to eight speeds. In this case, the second main transmission 1
The first to fourth speed clutches 21 to 2 of the first main transmission 10 are in a state where the first low speed clutch 26 is operated to the transmission side.
4 corresponds to the shift positions of the 1st to 4th speeds, and the 1st to 4th speed clutches of the 1st main transmission device 10 in the state where the high speed clutch 27 of the 2nd main transmission device 11 is operated to the transmission side. 21 to 24 correspond to the shift positions of the fifth speed to the eighth speed.

As shown in FIG. 3, one of the first main transmissions 10
A pressure sensor 74 for detecting whether or not the operating pressure has reached a predetermined pressure in a transmission state is provided in each of the first to fourth speed clutches 21 to 24 and the low speed and high speed clutches 26 and 27 of the second main transmission 11. The current shift positions (1st speed to 8th speed) of the first and second main transmissions 10 and 11 are detected by the detection of each pressure sensor 74, and the detected shift positions are displayed on the shift display section 64. (Step S7).

In the above state, it is assumed that the shift up button 61 or the shift down button 62 of the shift lever 28 is pushed once (steps S8 and S9). In this case, as indicated by the solid line A1 (time point B1) in FIG. 5, when the shift-up button 61 is pressed, the first main transmission device 10 at the shift position one step higher than the current shift position.
When the operation current is started to be supplied to the electromagnetic operation valves 31b to 34b for operation and the shift down button 62 is pressed in reverse, the first main shift at the shift position one step lower than the current shift position. Solenoid operated valves 31b-3 for device 10
The operation current starts to be supplied to 4b (step S1).
0).

At the same time, the solid line A2 in FIG. 5 (time point B1)
As shown in FIG. 5, the electromagnetic proportional valves 38, 39 of the low speed or high speed clutches 26, 27 operated on the transmission side in the second main transmission 11 cause the low speed or high speed clutches 26, 27 operated on the transmission side. The operating pressure is reduced from the operating pressure P2 in the transmission state to a predetermined low pressure P3 (step S11). In this case, the operating pressure of the low speed clutch 26 of the second main transmission device 11 is reduced to zero during the shift operation from the 4th speed shift position to the 5th speed shift position, and the high speed clutch 2
The operating pressure of 7 is increased from zero to a predetermined low pressure P3. On the contrary, during the shift operation from the 5th speed shift position to the 4th speed shift position, the operating pressure of the high speed clutch 27 of the second main transmission 11 is reduced to zero, and the operating pressure of the low speed clutch 26 is changed from zero to a predetermined low pressure. It is operated to ascend to P3.

Then, as indicated by the solid line A1 (time B2 to time B3) in FIG.
1st to 4th speed clutches 21 to 2 on the higher speed side or the lower speed side
The operating pressure of No. 4 is increased to the operating pressure P1 in the transmission state by the electromagnetically operated valves 31b to 34b. At the same time,
As indicated by the alternate long and short dash line A3 in FIG. 5 (from time B2 to time B3), the first speed before the push operation of the shift up button 61 or the shift down button 62 in the first main transmission 10 is performed.
The operating pressure of the fourth speed clutches 21 to 24 is equal to the solenoid operated valve 31b.
.About.34b, the operating pressure P1 in the transmission state is lowered to zero (step S12).

Next, the second low pressure P3 maintained at a predetermined low pressure
The operating pressure of the low speed or high speed clutches 26, 27 of the main transmission 11 is gradually increased by the solenoid proportional valves 38, 39 as shown by the solid line A2 (time B3 to time B4) in FIG. The operating pressure of the low speed or high speed clutch 26, 27 reaches the operating pressure P2 in the transmission state (step S1.
3). In this case, from the time point B3 to the time point B4 of the solid line A2 shown in FIG. 5, the rising characteristic of the operating pressure of the low speed or high speed clutch 26, 27 is set for each shift position,
The shift position on the lower speed side (first speed side) is from the time point B3 to the time point B
The operating pressure of 4 is rapidly increased in a short time.

As described above, the shift-up button 6
One or the shift operation by pressing the shift down button 62 is completed. When the shift operation is completed, the shift position after the shift operation is displayed on the shift display section 64 (step S14), and the buzzer 71 is pressed once. And the operator is informed of the end of the gear shift operation (step S15). The shift operation as described above is not continuously performed even if the shift-up button 61 or the shift-down button 62 is continuously pressed, and the shift-up button 61 or the shift-down button 62 is once returned and then pressed again. Otherwise, the next one shift operation is not performed (the above corresponds to the shift control means).

(5) Next, the shift operation of the auxiliary transmission 12 by the shift lever 28 will be described. For example, the forward / reverse lever 59 is operated to the forward position F (the forward clutch 5 is operated to the transmission side and the reverse clutch 6 is operated to the transmission interruption side), and the shift lever 28 is operated to the low speed position L. In the state (operation button 57 and lock pin 5
6 is a state in which the shift lever 28 is held at the low speed position L) and the operation button 57 is pushed to release the lock pin 56 from the guide plate 60 downward, the solenoid operated valve 36b shown in FIG. 36a is operated to the oil drain side, and the forward clutch 5 is automatically operated to the transmission cutoff side.

As a result, the speed change lever 28 is operated from the low speed position L to the neutral stop position N or the high speed position H while the operation button 57 is being pressed, and the operation button 57 is returned to the lock pin 56 to operate the speed change lever 28. Is held at the neutral stop position N or the high speed position H. In this case, when the operation button 57 is returned to the neutral stop position N, the switching valve 36a is operated to the supply side by the electromagnetic operation valve 36b,
The forward clutch 5 is immediately and automatically operated to the transmission side by the solenoid proportional valve 35. Operation button 5 at high speed position H
When 7 is returned, the solenoid operated valve 36b causes the switching valve 3
6a is operated to the supply side, and the forward clutch 5 is gradually and automatically operated to the transmission side by the solenoid proportional valve 35.

When the forward / reverse lever 59 is operated to the reverse position R (the reverse clutch 6 is operated to the transmission side and the forward clutch 5 is operated to the transmission interruption side), the speed change lever 28 is operated as described above. When the operation button 57 is pushed and returned, the reverse clutch 6 is automatically operated to the transmission cutoff side and the transmission side.

(6) Next, automatic shifting of the first and second main transmissions 10 and 11 when the auxiliary transmission 12 is operated to shift while the shift lever 28 is operated to the low speed position L will be described. To do. As shown in FIGS. 6 and 7, when the first and second main transmission devices 10 and 11 are operated to shift to a certain shift position and the shift lever 28 is operated to the low speed position L, the current first and second main transmission devices 10 and 11 are operated. The gear shift positions of the second main transmissions 10 and 11 are displayed on the gear shift display section 64 (step S
21).

Next, the shift lever 28 is operated from the low speed position L to the neutral stop position N (step S22), and the shift up button 61 and the shift down button 62 are not pressed (steps S23, S24), and the shift lever 28 is operated. Is operated from the neutral stop position N to the high speed position H (step S2
5, S26, S27), the first and second main transmissions 10,
11 is automatically shifted to the 1st speed shift position (step S28) (corresponding to the first shift means), and the shift display section 64
The gear position for the 1st speed is displayed at (step S29).

The above state will be described more specifically.
As shown by the solid lines A1 and A2 in FIG. 10, the first and second main transmissions 10 and 11 are operated to shift to the fifth speed shift position, the shift lever 28 is operated to the low speed position L, and the shift display portion 64 displays In the state in which the fifth speed gear position is displayed, the speed change lever 28 is operated from the low speed position L to the neutral stop position N, and the speed change lever 28 is neutralized without pressing the shift up button 61 and the shift down button 62. When operated from the stop position N to the high speed position H, the first and second main transmissions 10, 1
1 is automatically shifted from the 5th gear shift position to the 1st gear shift position, and the 1st gear shift position is displayed on the gear shift display portion 64.

Next, as shown in FIGS. 6 and 7, the first and second main transmissions 10 and 11 are operated to shift to a certain shift position, and the shift lever 28 is operated to the low speed position L so that the current first shift position is set. In a state where the gear shift positions of the first and second main transmissions 10 and 11 are displayed on the gear shift display section 64 (step S2
1) Move the speed change lever 28 from the low speed position L to the neutral stop position N
Operation (step S22), shift up button 61
And the shift down button 62 is not pressed (steps S23 and S24), the shift lever 28 is moved to the neutral stop position N.
Is operated again to the low speed position L (steps S25, S
26, S27), the first and second main transmissions 10, 11 are not operated to shift, and are left in the original shift position (shift position in step S21) (step S30) (first).
The gear shift display section 64 displays the original gear shift position.

The above state will be described more specifically.
As indicated by the solid line A1 and the alternate long and short dash line A3 in FIG.
In a state in which the second main transmissions 10 and 11 are operated to shift to the fifth speed shift position, the shift lever 28 is operated to the low speed position L, and the shift display section 64 displays the fifth speed shift position, When the speed change lever 28 is operated from the low speed position L to the neutral stop position N and the speed change lever 28 is operated from the neutral stop position N to the low speed position L again without pressing the shift up button 61 and the shift down button 62, First and second
The main transmissions 10 and 11 are not shifted and remain in the 5th gear shift position, and the gear shift display portion 64 displays the original 5th gear shift position.

Next, as shown in FIGS. 6 and 7, the first and second main transmissions 10 and 11 are operated to shift to a certain shift position, and the shift lever 28 is operated to the low speed position L so that the current first shift position is reached. In a state where the gear shift positions of the first and second main transmissions 10 and 11 are displayed on the gear shift display section 64 (step S2
1) Move the speed change lever 28 from the low speed position L to the neutral stop position N
It is assumed that the shift up button 61 and the shift down button 62 are pushed at the neutral stop position N of the speed change lever 28 (step S2).
3, S24). In this case, as in step S10 to S15 of FIG. 4 and FIG. 5 described in the previous section (4), one step higher speed side and one step lower speed side based on the push operation of the shift up button 61 and the shift down button 62 are performed. A gear shift operation is performed, the gear shift position after the gear shift operation is displayed on the gear shift display portion 64, and the buzzer 71 operates only once (steps S31 to S3).
2).

As described above, the shift up button 61 and the shift down button 62 are used to shift the first and second main transmissions 10 and 11 to desired shift positions, and then the shift lever 28 is moved from the neutral stop position N. Whether the high speed position H is operated or the low speed position L is operated again (step S25,
N = 1 in S26), the first and second main transmissions 1
Since 0 and 11 are maintained at the shift positions shifted by the shift up button 61 and the shift down button 62 (corresponding to auxiliary shift control means), the shift display portion 64 has the shift up button 61 and the shift down button. The gear shift position by 62 is displayed.

The above state will be described more specifically.
As shown by the solid line A1 and the alternate long and short dash line A4 in FIG.
In a state in which the second main transmissions 10 and 11 are operated to shift to the fifth speed shift position, the shift lever 28 is operated to the low speed position L, and the shift display section 64 displays the fifth speed shift position, It is assumed that the shift lever 28 is operated from the low speed position L to the neutral stop position N. Next, the neutral stop position N of the speed change lever 28
In the case where the shift down button 62 is pressed twice to shift the first and second main transmissions 10 and 11 from the shift position of the fifth speed to the shift position of the third speed, the shift lever 28 is neutralized thereafter. Even if the stop position N is operated to the high speed position H or to the low speed position L again, the first and second main transmission devices 10 and 11 are maintained in the third speed shift position. Indicates the shift position of the third speed.

(7) Next, the automatic shifting of the first and second main transmissions 10 and 11 when the auxiliary transmission 12 is operated while the transmission lever 28 is operated to the high speed position H will be described. To do. As shown in FIGS. 8 and 9, when the first and second main transmissions 10 and 11 are operated to shift to a certain shift position and the shift lever 28 is operated to the high speed position H, the The gear shift positions of the second main transmissions 10 and 11 are displayed on the gear shift display section 64 (step S
41).

Next, the shift lever 28 is operated from the high speed position H to the neutral stop position N (step S42), and the shift up button 61 and the shift down button 62 are not pushed (steps S43, S44), and the shift lever 28 is operated. Is operated from the neutral stop position N to the low speed position L (step S4
5, S46, S47), the first and second main transmissions 10,
11 is automatically shifted to the shift position of 8th speed (step S48) (corresponding to the second shift means), and the shift display portion 64
The eighth speed gear position is displayed on the display (step S49).

The above state will be described more specifically.
Shifting the first and second main transmissions 10 and 11 to the 5th speed shift position and operating the shift lever 28 to the high speed position H;
In the state in which the gear shift display portion 64 displays the fifth gear shift position, the gear shift lever 28 is operated from the high speed position H to the neutral stop position N, and the shift up button 61 and the shift down button 62 are not pressed, When the shift lever 28 is operated from the neutral stop position N to the low speed position L, the first and second main transmission devices 10 and 11 are automatically shifted from the fifth speed shift position to the eighth speed shift position, and the shift display section is displayed. The 64th gear position is displayed at 64.

Next, as shown in FIGS. 8 and 9, the first and second main transmissions 10 and 11 are operated to shift to a certain shift position, and the shift lever 28 is operated to the high speed position H to change the current speed to the present speed. In the state where the gear shift positions of the first and second main transmissions 10 and 11 are displayed on the gear shift display portion 64 (step S4
1) Move the speed change lever 28 from the high speed position H to the neutral stop position N
Operation (step S42), the shift up button 61
The shift lever 28 is moved to the neutral stop position N without pressing the shift down button 62 (steps S43 and S44).
Is operated again to the high speed position H (steps S45, S
46, S47), the first and second main transmissions 10, 11 are not operated to shift, and are left in the original shift position (shift position in step S41) (step S50) (second).
The gear shift display section 64 displays the original gear shift position.

The above state will be described more specifically.
Shifting the first and second main transmissions 10 and 11 to the 5th speed shift position and operating the shift lever 28 to the high speed position H;
In the state in which the gear shift display portion 64 displays the fifth gear shift position, the gear shift lever 28 is operated from the high speed position H to the neutral stop position N, and the shift up button 61 and the shift down button 62 are not pressed. When the speed change lever 28 is operated from the neutral stop position N to the high speed position H again, the first and second main transmissions 10 and 11 are not operated for speed change and are left at the speed change position of fifth speed. The original 5th gear position is displayed.

Next, as shown in FIGS. 8 and 9, the first and second main transmissions 10 and 11 are operated to shift to a certain shift position, and the shift lever 28 is operated to the high speed position H to change the current speed to the present speed. In the state where the gear shift positions of the first and second main transmissions 10 and 11 are displayed on the gear shift display portion 64 (step S4
1) Move the speed change lever 28 from the high speed position H to the neutral stop position N
It is assumed that the shift up button 61 and the shift down button 62 are pushed at the neutral stop position N of the speed change lever 28 (step S4).
3, S44). In this case, as in step S10 to S15 of FIG. 4 and FIG. 5 described in the previous section (4), one step higher speed side and one step lower speed side based on the push operation of the shift up button 61 and the shift down button 62 are performed. A gear shift operation is performed, the gear shift position after the gear shift operation is displayed on the gear shift display portion 64, and the buzzer 71 operates only once (steps S51 to S5).
2).

As described above, the shift up button 61 and the shift down button 62 are used to shift the first and second main transmissions 10 and 11 to desired shift positions, and then the shift lever 28 is moved from the neutral stop position N. Whether the low speed position L is operated or the high speed position H is operated again (step S45,
(M = 1 state in S46), first and second main transmission 1
Since 0 and 11 are maintained at the shift positions shifted by the shift up button 61 and the shift down button 62 (corresponding to auxiliary shift control means), the shift display portion 64 has the shift up button 61 and the shift down button. The gear shift position by 62 is displayed.

The above state will be described more specifically.
Shifting the first and second main transmissions 10 and 11 to the 5th speed shift position and operating the shift lever 28 to the high speed position H;
It is assumed that the shift lever 28 is operated from the high speed position H to the neutral stop position N while the shift display portion 64 displays the shift position of the fifth speed. Next, at the neutral stop position N of the gear shift lever 28, the shift down button 62 is pressed twice to shift the first and second main transmission devices 10 and 11 from the fifth gear shift position to the third gear shift position. In this case, whether the gear shift lever 28 is moved from the neutral stop position N to the low speed position L or again to the high speed position H after that, the first and second main transmissions 10 and 11 are set to the third speed shift position. The gear shift display portion 64 displays the gear shift position of the third speed.

[Other Embodiment] Step S28 shown in FIG.
In, for example, when the speed change lever 28 is operated from the low speed position L to the high speed position H while the first and second main transmissions 10 and 11 are being operated to shift to the fifth speed, the first and second main transmissions are operated. If the transmissions 10 and 11 are in the 5th gear position,
The shift operation may be automatically performed to any shift position from the first speed to the first speed. Step S shown in FIG.
At 48, for example, the first and second main transmissions 10, 1
When the speed change lever 28 is operated from the high speed position H to the low speed position L in the state in which the gear shift operation of 1 is performed to the fifth speed shift position, the first and second main transmission devices 10 and 11 shift from the fifth speed shift position to The shift operation may be automatically performed to any shift position of the sixth speed to the eighth speed.

In the structure shown in FIG. 10, the auxiliary transmission 12 is in the low speed position L and the first and second main transmissions 10, 11 are in the high speed position H when the auxiliary transmission 12 is in the high speed position H. The second main transmissions 10 and 11 are set so that the first shift position has a higher shift speed, and the shift range at the low speed position L (shift positions from the first speed to the eighth speed) and the shift position at the high speed position H are changed. Although the range (shift positions of 1st to 8th speed) is separated so as not to overlap at all, the vicinity of the shift positions of 6th to 8th speeds at the low speed position L and the 1st to 3rd speeds at the high speed position H are separated. The present invention can also be applied to a work vehicle that is set so as to overlap with the vicinity of the gear shift position.
The present invention can also be applied to a work vehicle in which the first and second main transmissions 10 and 11 are configured to be capable of shifting in 10 speeds or 6 speeds.
In the configuration shown in FIG. 1, the first and second main transmission devices 10, 1
1 is configured as a hydraulic clutch type, the first and second main transmissions 10 and 11 are configured as a gear shift type in which a shift member is operated to slide like an auxiliary transmission 12, and the shift members are hydraulic cylinders. Alternatively, it may be configured to perform a slide operation and a gear shift operation.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry. Further, the traveling speed changing structure for a working vehicle according to the present invention may be a traveling speed changing method for a working vehicle.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a transmission system in a mission case.

FIG. 2 is a diagram showing a linked state of a shift lever and an auxiliary transmission device, a shift display portion, and a linked state of each portion.

FIG. 3 is a hydraulic circuit diagram of first and second main transmissions and the like.

FIG. 4 is a diagram showing a flow of a shift operation by a shift up button and a shift down button of a shift lever.

FIG. 5 is a diagram showing a state of each part at the time of a gear shift operation using a shift up button and a shift down button of a shift lever.

FIG. 6 is a diagram showing a flow in the case where a shift lever shifts an auxiliary transmission from a low speed position to a high speed position.

FIG. 7 is a diagram showing a flow in the case of performing a shift operation of the auxiliary transmission from a low speed position to a high speed position by a shift lever.

FIG. 8 is a diagram showing a flow of a case where a shift lever shifts the auxiliary transmission from a high speed position to a low speed position.

FIG. 9 is a diagram showing a flow when the auxiliary transmission is shifted from a high speed position to a low speed position by a shift lever.

FIG. 10 is a diagram showing a flow in the case of performing a gear shift operation of the auxiliary transmission with a gear shift lever.

FIG. 11 is a diagram showing a conventional flow when the auxiliary transmission is gear-shifted by a gear shift lever.

[Explanation of symbols]

10, 11 Main transmission 12 Auxiliary transmission 28 Second Artificial Manipulation Tool 61,62 1st manual operation tool L Low speed position of auxiliary transmission H High speed position of auxiliary transmission N Auxiliary transmission neutral stop position

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-1007023 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B60K 20/00 F16H 61/00

Claims (2)

(57) [Claims] 1. A main transmission (1) capable of shifting in a plurality of stages.
0), (11) and an auxiliary transmission (1
2) and 1 are arranged in series and are manually operated by the first artificial operation tools (61), (62)
On the basis of the above, the main transmission device (10), at the shift position corresponding to the operation of the first manual operation tool (61), (62),
(11) is provided with a shift control means and a sub-transmission device (12) for shifting, and is provided with a second artificial operation tool (28) that is artificially operated, and the first manual operation is performed. The sub-transmission device (12) is operated by the second manual operation tool (28) while the main transmission devices (10), (11) are being shifted to a certain shift position by the tools (61), (62). When the gear shift operation is performed from the low speed position (L) to the high speed position (H), the shift position is set to a speed lower than the shift positions of the main transmissions (10) and (11) before the shift operation. In preference to the shift control means, the main transmission device (10),
A first speed change means for automatically changing the speed of (11), and a speed change operation of the main speed change devices (10), (11) to a certain speed change position by the first manual operation tools (61), (62). When the sub-transmission (12) is shifted from the high speed position (H) to the low speed position (L) by the second manual operation tool (28) while the main transmission is in the state before the shift operation ( The main transmission device (10), in preference to the shift control means, so that the shift position is located on a higher speed side than the shift positions of 10) and 11).
A second speed change means for automatically changing the speed of the sub-transmission device (1).
2) is neutral from the low speed position (L) or the high speed position (H)
In the state where the shift operation is performed to the stop position (N),
The main transmission by the one-manual operation tools (61), (62)
When the gear shift operation of (10) and (11) is performed, the gear shift operation is performed by the first manual operation tools (61) and (62).
After that, the auxiliary speed change device is operated by the second manual operation tool (28).
Position (12) shifts to low speed position (L) and high speed position (H)
Even if it is operated, it takes precedence over the first and second shifting means,
The first artificial operation tool (61) at the neutral stop position (N),
The main transmission is set to the shift position after the shift operation according to (62).
Auxiliary shift control means for maintaining (10) and (11) is provided.
A structure for changing the traveling speed of a work vehicle. 2. The second manual operation tool (28) shifts the auxiliary transmission (12) from the low speed position (L) to a neutral stop position (N) and again to the low speed position (L). Then, the sub-transmission device (1) is controlled by the first restraint means that leaves the main transmission devices (10) and (11) at the shift position before the shift operation, and the second artificial operation tool (28).
When 2) is shifted from the high speed position (H) to the neutral stop position (N) and again shifted to the high speed position (H), the main transmission (10),
The traveling speed change structure for a work vehicle according to claim 1, further comprising a second check mechanism for leaving (11).