JPS609075Y2 - PTO device for agricultural tractors - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a circular Q device provided in an agricultural tractor for driving a working machine such as a rotary tiller.

In an agricultural tractor, an overload tends to act on a PTO device that drives a working machine such as a rotary tiller from the working machine side while the working machine is being driven.

In other words, from the perspective of the work equipment itself, abnormal loads are applied to the work equipment, such as when the rotary tiller's tilling claw hits a stone, encounters a layer of hard mud, or passes through a mound of mud while tilling. This is particularly caused by the fact that, when viewed from a single tractor, the running speed of the machine is excessive compared to the work load that the machine is subjected to.

The overload effect caused by the latter cause is particularly important when performing high-load work such as trencher work or deep plowing rotary work that requires the machine to operate at an extremely low speed. This happens when someone accidentally increases the speed of the vehicle.

In addition, overload tends to act on the PTO device of agricultural tractors from the working equipment side, and such overload tends to cause damage to transmission members such as damage to gears. Conventionally, no particular measures have been taken to protect the transmission member from such overload and ensure safety.

The purpose of this invention is to
In agricultural tractors with an O-axis extending from inside the machine to outside the machine, we have devised the structure and arrangement of the clutch that selectively rotates and stops the PTO shaft. The object of the present invention is to provide a new PTO device in an agricultural tractor, which is designed to protect the transmission member from overloads acting on the tractor.

Regarding the illustrated embodiment, to explain the configuration of the PTO device in the agricultural tractor according to the invention, as shown in FIG. 2 is forcibly driven, and the aircraft is steered by an operator sitting on a seat 3 rotating the front wheels 5 using a handle 4. A rotary tiller 6 is equipped with a connection mechanism 7 for a working machine and a hydraulic lift mechanism 8 for the working machine 6, and a PTO shaft 9 rotatably driven by the engine 1 is interlocked and connected 10 to the working machine 6. ,
In the agricultural tractor configured to drive the work implement 6, the gate temperature device according to this invention has the following configuration.

That is, as shown in FIG. 2, in the housing at the rearmost part of the fuselage, there is a main clutch (
Intermediate shaft 1 interlockingly connected to engine 1 via (not shown)
1 is provided, and the following PTO transmission mechanism is provided between the intermediate shaft 11 and the PTO shaft 9.

That is, first, on the intermediate shaft 11, there are two integral shift gears 1 having a common boss portion and different diameters.
2.13 is provided through a spline 14 so as to be slidable but not relatively rotatable, and the PTO shaft 9 is provided with three integral gears 15, 16, and 17 having a common boss portion. Three gears 15, 16, and 17 having different diameters are loosely fitted, of which gears 15 and 16 are configured to selectively mesh with shift gears 12 and 13, respectively. In this way, the shift gears 12, 13 and the gears 15 and 16 constitute a mechanical transmission or gear type transmission 18.

In addition, three gears 19, 20, 21, which have a common boss portion and have different diameters, are loosely fitted into the intermediate shaft 11. Of these, the gear 19 with the largest diameter is meshed with the gear 17 with the smallest diameter described above on the PTO shaft 9.

Furthermore, the PTO shaft 9 is loosely fitted with gears 22 and 23 that are meshed with the other two gears 20 and 21 on the intermediate shaft 11, respectively.
．． 23 is selectively coupled to the PTO shaft 9. Multi-disc hydraulic clutches 24 and 25 are provided, and by selectively operating either of the hydraulic clutches 24, 25, either Selectively PTO gear 22 or 23
Connected to the shaft 9, with which the gear 20.22 or the gear 21,
The intermediate shaft 11 and the PTO shaft 9 are transmission-connected via the gear 23, and thus a hydraulic clutch type transmission 26 is constituted by the gears 20-23 and the hydraulic clutches 24, 25.

To explain in more detail, a hydraulic clutch 2 is mounted on the boss portion of the gears 22 and 23 arranged on the same axis as the PTO shaft 9.
Support portions 22a and 23a extending into the 4.25 are integrally formed.

Also, the clutch housing 24 of the hydraulic clutch 24.25
a.

25a is provided integrally with the PTO shaft 9 by locking keys 27 and 27' to the P'RO shaft 9.

And each hydraulic clutch 24.25 is connected to each gear 22.23.
A plurality of one-side friction plates 28 are slidably supported on the inner peripheral end side of the friction plates 28 by each of the above-mentioned supporting parts 22at23a, which are integrated with the PT'O shaft 9. Each of the clutch housings 24a, which is a supporting part,
, 25a supports a plurality of other friction plates 29 on the outer peripheral end side of the friction plates 29 so as to be slidable only, thereby forming a multi-plate structure.

Each clutch housing 24a. There is a friction plate 28 inside 25a.
．． A piston 30 facing the 29th group is biased by a return spring 31 to move in a direction opposite to the friction plate 28 and the 29th group, and each clutch housing 24a, 2
Inside 5a is an oil chamber 32 for applying hydraulic pressure to the piston 30 to slide the friction plate in the direction of the 28th and 29th groups against the urging force of the return spring 31.

Each hydraulic clutch 24, 25 selectively applies hydraulic pressure to the oil chamber 32 to move the piston 30 to the friction plate 28.
．． It is said that it is selectively activated by slidingly displacing it in the direction of the 29 group and frictionally engaging the friction plates 28 and 29 by the pressing force of the piston 30, and when the hydraulic action is released, the return spring The movement of the piston 30 by the applied force 31 releases the engagement between the friction plates 28 and 29, rendering them inoperative.

The illustrated circle 0 device according to this invention is constructed as described above, and therefore includes a shift fork (not shown) fitted in the shifter fitting groove 37 between the shift gears 12 and 13, and a hydraulic clutch 24. Hydraulic pressure supply/discharge mechanism to .25 (not shown)
and selectively operate the gear type transmission 18 to perform a two-speed shift, and for each gear, the hydraulic clutch type transmission 26 to perform a two-speed shift, thus a total of four speeds to the PTO shaft. 9, and by operating the hydraulic supply/discharge mechanism described above, the neutral state of the hydraulic clutch type transmission 26 is obtained with both hydraulic clutches 24 and 25 inactive, and the circular O axis 9 is obtained. The rotation of the PTO shaft 9 can be easily stopped, but this is because the multi-plate hydraulic clutch 24, 25 is provided with only the PTO shaft 9 on the driven side and no other transmission members. This provides the following advantages:

In other words, from a working machine such as a rotary tiller, overload occurs when the rotary tiller's tilling claws hit a stone, encounter a layer of hard mud, or pass through a raised area of mud. However, such overload is likely to occur on the multi-disc hydraulic clutch 24. which is located closest to the work machine.
25, it is absorbed by the slip between the friction plates 28 and 29 of the hydraulic clutch, and does not reach the transmission members such as gears on the front stage of the PTO transmission path, thereby preventing damage to the transmission members in the p'ro transmission system. It will be done.

Multi-disc hydraulic clutch 24 during the above-mentioned overload operation.
Based on the slip of 25, the work equipment is also protected.

In other words, if the work equipment were to be driven at the same rotational speed as before when an overload was applied, strain would be applied to the working members such as the tilling claws of the work equipment, which would damage the members. In the PTO device, the drive speed of the work equipment is reduced to a value suitable for the overload due to the slip of the multi-disc hydraulic clutch 24, 25 when an overload is applied.
The working machine is protected without the above-mentioned member damage.

Note that the same advantages can be obtained even if only one multi-disc hydraulic clutch is provided, or even if the multi-disc hydraulic clutch is of a spring-loaded type in which the clutch is engaged by a spring and the engagement is released by hydraulic pressure.

As is clear from the above description, the PTO device for the agricultural tractor of this invention is provided in such a way that the circular axis 9 for transmitting power to the working machine extends from the inside of the machine to the outside of the machine.゛The rotation transmission part 22.23 for transmitting input to the 0-axis 9 is arranged on the same axis as the PTO shaft 9, and the support parts 22a, 23a and the above-mentioned One friction plate 28 and the other friction plate 29 for a plurality of sheets are supported by other supporting parts 24a and 25a provided integrally with the PTO shaft 9 so that they can only slide freely, respectively. The present invention is characterized by a multi-plate hydraulic clutch 24, 25 that can selectively connect and disconnect power transmission to the gate shaft 9 by frictional engagement and disengagement between the clutches 24 and 25, and provides the following effects.

That is, in the circle zero device of this invention, one friction plate 28 is attached to the support members 22a and 23a, which are integrally provided with the rotary transmission members 22 and 23 disposed on the same axis as the PTO shaft 9, and also on the circle zero axis. Other support parts 24a, 2 provided integrally with 9
5a supports the other friction plate 29, respectively, to form the multi-plate hydraulic clutch 24.25. Therefore, the driven side of the hydraulic clutch 24.25 has a clutch of the hydraulic clutch. There are no transmission members other than the PTO shaft 9, which is rotated and stopped by engaging and disengaging, and all transmission members such as gears are installed on the driving side of the multi-plate hydraulic clutch 24, 25. That's it.

Multi-disc hydraulic clutches use hydraulic pressure (springs for spring-loaded clutches) to obtain frictional engagement force between frictional elements, and spring force (for spring-loaded clutches, hydraulic pressure) to maintain frictional engagement between the frictional elements. If a load greater than the value corresponding to the hydraulic pressure (or spring force) required to engage the clutch is applied from the clutch driven side, the clutch will be released against the hydraulic pressure (or spring force). It has a characteristic of slipping between friction elements.

Therefore, according to this invention, the multi-disc hydraulic clutch 24 makes it easy to selectively rotate and stop the PTO shaft 9 because its operation is controlled by valve operation.
When an overload is applied to 25 from the working machine side, the overload is prevented from reaching all other PTO system transmission members such as gears except for the PTO shaft 9, and the PT
The O-system transmission member is protected to prevent damage, and since the multi-disc hydraulic clutch 24, 25 slips as described above when an overload is applied from the work equipment side, the drive rotation of the work equipment is prevented. As a result, the excessive force exerted on the working member of the working machine is eliminated, and the working machine is also protected.

[Brief explanation of the drawing]

FIG. 1 is a side view of an agricultural tractor equipped with an embodiment of this invention, and FIG. 2 is a longitudinal sectional view of the same embodiment. 9...PTO axis, 11...Intermediate shaft, 2
2.23... Gear, 22a, 23a... Curved support part, 24, 25... Multi-plate hydraulic clutch, 24
a, 25a... Bent clutch housing (support part), 26
・・・・・・Hydraulic clutch type transmission, 27.27'・
...Key, 28.29...Friction plate, 30
...Zeston, 31...Return spring,
32... Oil room.

Claims (1)

[Scope of utility model registration request] In an agricultural tractor in which a PTO shaft 9 that transmits power to a working machine is extended from inside the machine to outside the machine, the PTO
Rotary transmission member 22.2 for transmitting input to the O-axis 9
3 are disposed on the same axis as the PTO shaft 9, and are provided integrally with the rotational transmission member 22, 23.
and another support portion 24 provided integrally with the PTO shaft 9.
A, 25a supports one friction plate 28 and the other friction plate 29 for a plurality of sheets so that they can only slide freely, and the front yTO axis is moved by frictional engagement and disengagement between these friction plates 28 and 29. 9. A PTO device for an agricultural tractor, characterized by comprising a multi-disc hydraulic clutch 24, 25 that can selectively connect and disconnect power transmission to the agricultural tractor.