JPS5939075Y2 - Transmission device in tractor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transmission system for a tractor that has a so-called live PTO, which can drive the PTO regardless of whether the tractor is traveling.

Two-stage clutch type and power shift type are known as conventional live PTOs, but the former has an expensive two-stage clutch and a two-stage clutch consisting of a shaft and a hollow shaft that fits the shaft.
It required a heavy shaft and a gear independent of the traveling system, making it very expensive.

Furthermore, the latter requires a friction clutch for each transmission gear, making it expensive and requiring a complicated control system.

Therefore, it consists of a human power main shaft, a traveling transmission shaft system to which power is branched and transmitted from the human power main shaft, and a PTO power transmission shaft system shaft, and a friction clutch is interposed in the traveling transmission shaft system.
A transmission has been proposed that can share the transmission gear of a human-powered main shaft and be used as a live PTO.

However, in this transmission, it is necessary to operate the friction clutch in addition to the main clutch, making the operation very troublesome.

In view of the above-mentioned circumstances, the present invention is designed so that a valve is interlocked with the main shift lever, and a friction clutch can be operated by operating the valve based on the main shift lever, thereby making it possible to perform gear shifting operations without operating the clutch. It is an object of the present invention to provide a transmission device for a tractor that is configured to have the following characteristics.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

As schematically illustrated in FIG. 1, the transmission 2 of the tractor 1 includes an input main shaft 6 connected to an engine 3 via a main clutch 5, and a driving transmission shaft disposed parallel to the input main shaft 6. system 7 and a power transmission shaft drive shaft system 9 for PTO.

Four gears 10.degree. 11, 12.13 are fixed to the input main shaft 6, and each gear 10.degree. 11.12° 13 is an idling gear 10', 11', 12', which is rotatably supported by the traveling subshaft 7a of the traveling transmission shaft system 7.
Shift gears 10", 11", 12", which are always in mesh with 13' and at the same time are slidably supported by the subshaft 9a of the PTO transmission shaft drive shaft system 9TO,
13" can be selectively engaged.

Further, the traveling subshaft 7a is provided with a synchronous mesh clutch 15.16.
is supported so that it can only slide freely, and the clutch 15.16
As shown in FIG. 2, the main shift lever 17 is operated to engage synchronously with any of the idle gears 10', 1, 12', and 13' via the shift rail 19 and shift fork 20. It is possible.

Furthermore, the traveling subshaft 7a is connected to the traveling intermediate shaft 7b via a friction clutch 21.

The friction clutch 21, as shown in FIG.
The valve 23 is operated by the hydraulic pressure generated by the pump 22 driven by the rotation of the synchronized mesh clutch 1 driven by the main gear shift lever 17.
At the time of operation 5.16, the plunger 25 provided on the shift rail 19 is operated, and the friction clutch 21 is brought into a disengaged state in synchronization with the operation of the clutch 15.16.

On the other hand, two gears 26 and 27 are fixed to the traveling intermediate shaft 7b, and the gears 26 and 27 are auxiliary transmission gears that are only slidably supported by a pinion shaft 29 that is aligned with the human-powered main shaft 6. It is selectively engaged with 26' and 27'.

Further, the pinion shaft 29 is connected to a differential shaft 31 via a differential gear 30, and further connected to left and right rear wheels 35 via final gears 32 and 33.

In addition, 36.36 in the figure is a brake provided on the differential shaft 31 for making a sharp turn of the tractor.

On the other hand, the PTO subshaft 9a is connected to the PTO shaft 9b via the cutout 37.
One end of the PTO shaft protrudes from the tractor body.

In addition, 39.39 in the figure is the front wheel of the tractor 1.

Since the present invention has the above-mentioned configuration, the rotation of the engine 3 is transmitted to the human-powered main shaft 6 via the main clutch 5, and further to the gear 10. Each gear 10', 11', 12', 1 of the traveling transmission shaft system 7 via 11.12.13
3' and shift gears 10'', 1',
12" and 13" are selectively engaged to transmit the power to the PTO transmission shaft drive shaft system 9TO subshaft 9a.

Therefore, the PTO subshaft rotates at a predetermined rotational speed of the four-speed gear, regardless of the stoppage or rotational speed of the traveling transmission shaft system, and further drives the PTO shaft 9b at the same speed.

In addition, each idle gear 10', 11 of the traveling transmission shaft system 7
', 12', and 13'' are rotated by the gear shift lever 17.
As a result of the operation, the synchronous dog clutch 15, 16 frictionally engages with one of the gears, and after reaching the synchronous speed, based on the reliable engagement, the predetermined rotation speed is set to the traveling subshaft 7a by a smooth gear change operation. communicated.

At this time, by operating the speed change lever 17, the valve 23 is switched and operated by the plunger 25 via the shift rail 19 immediately before the synchronous mesh clutch is frictionally engaged.
Pressure oil from the pump 22 is sent to the friction clutch 21, and the clutch 21 is brought into a disengaged state.

This eliminates the need to manually operate the clutch.
In addition, the main clutch 5 remains connected, that is, the PTO shaft 9b
The speed of the traveling transmission shaft system 7 can be changed as appropriate while maintaining the driving state.

Furthermore, synchronous mesh clutch 15. 16 engages, the friction clutch 21 also becomes connected, and the traveling subshaft 7
The rotation of a is transmitted to the traveling intermediate shaft 7b.

The rotation of the intermediate shaft 7b is controlled by the sub-shift gear 2 based on the sub-shift lever.
The signal is transmitted to the pinion shaft 29 by the selective meshing of 6' and 27', and is further transmitted to the rear shaft 35 via the differential gear 30, shaft 31, and final gears 32 and 33, so that the tractor 1 travels at a desired speed.

As explained above, according to the present invention, the main shift lever 1
Since the friction clutch 21 is operated by the valve operated in conjunction with the operation of 7, even though the main clutch 5 remains connected, that is, the PTO shaft 9b is kept in the driven state, and the PTO is in a live PTO state, There is no need to operate a clutch, and gear shifting can be performed without a clutch, making it easy to shift gears.

In addition, the main gear shift for driving can be performed by simply disengaging the friction clutch 21 without disengaging the main clutch 5, so the main clutch 5 can be kept in the connected state and can be used for driving. Even when changing gears, the PTO
The drive state of the shaft 9b at a predetermined rotation speed can be maintained.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view showing the transmission of the tractor, and FIG. 2 is a schematic diagram showing the main speed change operation portion of the driving transmission shaft system. 1...Tractor, 2...Transmission, 3
...Engine, 5...Main clutch, 6
...Human power main shaft, 7...Transmission shaft system for traveling, 9...Transmission shaft system for PTO, 10゜11, 12
．． 13...Gear, 15.16...Synchronous mesh clutch, 17...Main gear shift lever, 21
...Friction clutch, 23...Valve.

Claims (2)

[Scope of utility model registration request] (1) Traveling where transmission is selectively branched as appropriate via an input main shaft connected from the engine via a main clutch and a plurality of gears arranged parallel to the main shaft and fixed to the main shaft. In a transmission device for a tractor that includes a transmission shaft system and a PTO transmission shaft system, a friction clutch is interposed in the traveling transmission shaft system, and a plurality of gears of the human-powered main shaft are connected to the traveling transmission shaft system. A main gear shift lever is provided for selectively transmitting the transmission, and a valve is provided that is operated by a selective operation of the main gear shift lever, and the friction clutch is operated by a switching operation of the valve based on the operation of the main gear shift lever. A transmission device for a tractor configured to (2) A transmission device for a tractor according to claim 1, which uses a synchronized mesh clutch for selectively transmitting power from the human-powered main shaft to the traveling power transmission shaft system.