JPH0621614B2 - Transmission for traveling of work vehicle - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a power transmission device for traveling of a work vehicle provided with a main transmission mechanism and an auxiliary transmission mechanism.

[Conventional technology]

In such a traveling transmission device for a work vehicle, conventionally, all the power changed by the main transmission mechanism is output to the traveling device via the auxiliary transmission mechanism.

[Problems to be solved by the invention]

By the way, when you want to move the work vehicle to the next work place quickly after finishing work at one work place, operate the main speed change mechanism to the high speed side to drive the work vehicle at the maximum forward speed. become.

However, in the above-mentioned conventional configuration, when the main transmission mechanism is operated to the high speed side to perform the shift operation to the maximum forward speed, when the auxiliary transmission mechanism is operated to the low speed side, the maximum forward speed is changed. Therefore, the sub-transmission mechanism must be switched to the high speed side, and the operation for shifting to the maximum forward speed is troublesome.

An object of the present invention is to make it possible to shift to the maximum forward speed only by operating the main transmission mechanism even when the auxiliary transmission mechanism is operated to the low speed side, and to simplify the structure for that. It is to obtain with a simple configuration.

[Means for solving problems]

A characteristic configuration of the present invention includes a main transmission device and an auxiliary transmission mechanism, a traveling output shaft for guiding engine output after gear shifting by the transmission mechanisms to the rear wheel side, and a front wheel for guiding to the front wheel side. In a transmission for traveling of a work vehicle provided with a power transmission shaft, an output unit of speeds other than the maximum forward speed of the main speed change mechanism is interlocked with the auxiliary speed change mechanism to output the maximum forward speed of the main speed change mechanism. The part is detoured from the transmission upper side of the auxiliary transmission mechanism to the transmission lower side of the auxiliary transmission mechanism via the front wheel transmission shaft, and is linked to the traveling output shaft.

[Work]

That is, the output obtained by shifting the main transmission mechanism to a speed other than the maximum forward speed is transmitted to the traveling device via the auxiliary transmission mechanism. Further, the output obtained by shifting the main transmission mechanism to the maximum forward speed is directly transmitted to the traveling device.

〔The invention's effect〕

Therefore, only by performing the gear shifting operation to bring the main transmission mechanism to the maximum forward speed, it is possible to shift to the maximum forward speed regardless of the gear shift operation state of the auxiliary transmission mechanism, and the operability can be improved. It became so.

Further, since the front wheel drive shaft provided for driving the front wheels is used as a means for bypassing the auxiliary transmission mechanism when transmitting the maximum forward speed to the traveling output section, the bypass transmission is used. There is no need to add a new transmission shaft to do this. Therefore, there is an effect that the above-described traveling transmission device with a simple structure can be obtained with a simple structure without causing disadvantages such as complication of the structure and necessity of securing an installation space.

〔Example〕

A traveling transmission device of an agricultural tractor, which is an example of a work vehicle, will be described.

As shown in FIG. 1, a drive side transmission shaft of a transmission system to a connecting work device to which power from an engine (not shown) is transmitted.
Wet friction clutch (3) between (1) and driven shaft (2)
And the power transmitted to the driven side transmission shaft (2) is transmitted through the gear reduction mechanism (4) as a power take-off shaft.
A PTO transmission system is configured by transmitting the power to the TO shaft (5) and providing a switching gear (6) for displaying the live neutral ground PTO transmission state on the driven side transmission shaft (2). .

Next, the traveling transmission system will be described. A traveling first transmission shaft (7) is fitted on the transmission side of the drive side transmission shaft (1) so as to be rotatable relative to the drive side transmission shaft. Transmission 1st transmission shaft (7) for transmission Transmission upper transmission shaft (7A) and lower transmission shaft (7B)
And a planetary gear type high / low speed switching device (8) (a so-called dual transmission mechanism, which is a so-called dual speed change mechanism) between these transmission shafts (7A) and (7B) via a friction multi-plate hydraulic clutch between them. 25% speed deceleration) is provided, and 8 forward speeds and 1 reverse speed are provided between the second lower transmission shaft (7B) and the traveling second transmission shaft (9) installed in parallel. A main transmission mechanism (10) having a possible synchronized mesh type gear transmission is provided.

A second drive shaft for traveling (9) as an output unit of speeds other than the maximum forward speed of the main speed change mechanism (10) is linked to the auxiliary speed change mechanism 12 and is rotated relative to the drive shaft (9). A freely traveling third transmission shaft (11) is butted and opposed.

Explaining the sub-transmission mechanism (12), the output gear (13) fixed to the second transmission shaft (9) and the third transmission shaft (11) are loosely fitted to each other via a clutch sleeve (14). Transmission gears (18) for the front wheels, in which relay gears (16), (17) that mesh with the input gears (15) are installed in parallel with the second transmission shaft (9) and the third transmission shaft (11) The reduction gear mechanism (19) is loosely fitted to the second transmission shaft (9) by switching the clutch sleeve (14).
It is configured to be switchable between a high-speed transmission state in which it is directly connected to the transmission shaft (11) and a low-speed transmission state in which the output of the second transmission shaft (9) is transmitted to the third transmission shaft (11) via the reduction mechanism (19). There is.

A bevel gear for transmitting power to a rear wheel differential device (20) as a traveling device is provided at a rear end of the traveling third transmission shaft (11).
While arranging the traveling output shaft (22) with (21) fitted on the outside,
An ultra-reduction mechanism (23) is provided between the third transmission shaft (11) and the output shaft (22) so that the speed can be changed between high and low. This super reduction mechanism (23) comprises an output gear on the third transmission shaft (11).
(24) and the output shaft (22) is provided with a clutch sleeve (26) also serving as an input gear (25), and both gears (24), (25)
Install the relay gears (27) and (28) that mesh with the mesh case (2
It is provided on the shaft (30) supported on the 9) side.

In this way, the output of speeds other than the maximum forward speed changed by the main transmission mechanism (10) is output through the auxiliary transmission mechanism (12) and the super speed reduction mechanism (23) to the rear wheel differential device (20). Input to the front wheel transmission shaft (18) and transmitted to the front wheel output shaft (18) via the gear mechanism (31), and the output transmitted to the transmission shaft (18) is output to the front wheel output shaft (32) to the reduction mechanism (33). The output synchronized with the rear wheels is transmitted to the front wheels. Then, the output of the maximum forward speed changed by the main transmission mechanism (10) is bypassed to the sub transmission mechanism (12) and transmitted to the rear wheel differential device (20) and the front wheel differential device (not shown). Is done. More specifically, as shown in FIG. 2, an overtop gear (34) as an output portion of the maximum forward speed of the main transmission mechanism (10) is loosely fitted to the front wheel transmission shaft (18), and The transmission of the output transmitted to the gear (34) to the transmission shaft (18) by the synchro mesh type is constructed so as to be intermittent so that the main gear changeover lever (35) is overdriven as shown in FIG. The first drive shaft for traveling by operating to the top position
The power from (7) bypasses the auxiliary transmission mechanism (12) and is transmitted from the front wheel transmission shaft (18) to the front wheel output shaft (32) and the traveling output shaft (22).
It is configured to transmit to.

In addition, the switching gear (6) is provided below the operation lever (36) for operating the switching gear (6) from the neutral PTO to the drive lever (36).
Electromagnetic valve (37) for operating the friction clutch (3) intermittently only when switching to the TO or from the leap PTO to the neutral PTO The limit switch (38) for operating
Is provided. In other words, switch gear (6) to neutral P
Operation lever (36) when operating from TO to live PTO
By contacting the projection (36A) formed on the lower end of the operation lever (36) with the initial operation of, the limit switch (38)
Is turned on, the electromagnetic valve (37) is switched, the friction clutch (3) is turned off, and the operating lever (36) is further operated to switch to the live PTO, and the limit switch (38) is turned off. Spring the valve (37)
The friction clutch is switched to the drain position by the urging force of (39).
By operating (3), the gears can be engaged with each other without damaging the occlusal part. or,
Change the switching gear (6) from live PTO to neutral PT
When operating to O, disengage the friction clutch (3) in the same manner as above and then release the engagement of the gears,
The operating force of the operating lever (36) for operating the switching gear (6) is reduced.

Incidentally, reference numeral (40) in FIG. 1 denotes a clutch for switching between two-wheel (rear wheel) drive and four-wheel drive.

[Brief description of drawings]

The drawings show an embodiment of a transmission system for traveling of a work vehicle according to the present invention, and FIG. 1 is a transmission system diagram in a mesh case, and FIG.
FIG. 4 is a sectional view of the main transmission mechanism, FIG. 3 is a schematic view showing a switching state of a switching gear, and FIG. 4 is a plan view of a shift switching display portion. (9), (34) …… Output section, (10) …… Main transmission mechanism, (12) ……
Auxiliary speed change mechanism, (18) ... front wheel transmission shaft, (22) ... traveling output section, (20) ... traveling device.

Claims (1)

[Claims] 1. A traveling output shaft (1) comprising a main transmission device (10) and an auxiliary transmission mechanism (12), for guiding engine output after shifting by these transmission mechanisms (10, 12) to the rear wheel side. 22) and a front wheel transmission shaft (18) for guiding to the front wheel side, which is a work transmission transmission device for a working vehicle, wherein a speed output unit other than the maximum forward speed of the main transmission mechanism (10) is output.
(9) is linked to the sub-transmission mechanism (12), and the maximum forward speed output section (34) of the main transmission mechanism (10) is connected to the front wheel from the transmission side of the sub-transmission mechanism (12). Transmission shaft (1
A work transmission device for a working vehicle, which is circumvented to the transmission lower side of the auxiliary transmission mechanism (12) via 8) and is interlockingly connected to the travel output shaft (22).