JPH0246408B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a power extraction device for a tractor that drives a drive-type working machine such as a rotary or a mower.

<Prior art> A so-called independent power take-off device (live PTO) that intermittents engine power via a hydraulic clutch transmission mechanism and independently drives the PTO shaft via the transmission mechanism.
There is.

This live PTO is different from the ground PTO and is often used to drive drive-type work equipment.

<Problems to be Solved by the Invention> In the conventional technology, when a brake is provided to prevent the hydraulic clutch mechanism from rotating, a brake with a large capacity is required, and it is difficult to assemble it in a narrow tractor body. Even that was difficult.

Furthermore, if a continuous rotation prevention brake is not provided, torque from the working machine side will be transmitted, leading to failure of the traveling system.

An object of the present invention is to provide a one-way clutch on the drive system shaft of a live PTO, thereby making it possible to obtain continuous rotation torque and at the same time use a small capacity brake.

<Means for Solving the Problems> The technical means taken by the present invention to achieve the above-mentioned object are characterized by the following: PTO transmission mechanism 1 via hydraulic clutch mechanism 12
5 is driven and the PTO shaft 3 of the PTO transmission mechanism 15
3, a link prevention brake mechanism 23 is provided to brake the inertia energy of the clutch body 17 in the hydraulic clutch mechanism 12, and a PTO drive system shaft between the hydraulic clutch mechanism 12 and the PTO transmission mechanism 15 is provided. 10 and on the input side of the PTO transmission mechanism 15, the PTO
A one-way clutch mechanism 14 is provided that transmits power only toward the transmission mechanism 15.

<Function> The hydraulic clutch mechanism 12 is connected, and the PTO
When the transmission mechanism 15 is in the transmission state, the rotational power of the engine 4 is transferred to the hydraulic clutch mechanism 12,
The signal is transmitted to the PTO transmission mechanism 15 via the one-way clutch 14, and rotates the PTO shaft 33 under the required speed change, thereby driving various work machines.

When the hydraulic clutch mechanism 12 is disconnected, the aforementioned power is disconnected, but after this disconnection, the continuous rotation of the clutch body 17 due to inertial energy is prevented by the brake mechanism 23, and on the other hand, the continuous rotation torque from the PTO transmission mechanism 15 is prevented. Even if it works, this
It is shut off by the one-way clutch mechanism 14.

<Example> Referring to FIG. 3, a two-axis 4 to which the present invention is applied
A wheel-type tractor 1 is illustrated, and 2 is a front wheel;
3 is a rear wheel, 4 is an engine, and 5 is a transmission case, which is connected to the engine 4 to constitute a tractor body.

Referring to FIG. 1, reference numeral 6 denotes a transmission shaft for the traveling system, which has a cylindrical shaft structure and is interlocked and connected to the engine 4 via a clutch (not shown), and is connected to a differential mechanism 9 via a transmission gear mechanism 7 and a drive pinion shaft 8. Rear wheel 3 is linked
is driven.

10 is a PTO drive shaft system, and a first shaft 11 is inserted into the speed change shaft 6 and interlocked with the engine 4.
and a second shaft 13 connected to the first shaft 11 via a hydraulic clutch mechanism 12, and operatively connected to a PTO transmission mechanism 15 via a one-way clutch mechanism 14.

The hydraulic clutch mechanism 12 includes a clutch drive plate element 16 attached to the rear end of the first shaft 11 and a second shaft 1.
A hydraulic piston 18 is fitted into the clutch body 17 to freely connect and disconnect a clutch plate 19, and the clutch body 17 is fitted and supported by a holder 20.

The holder 20 is formed with an oil passage 22 and the like that sends pressure oil from the hydraulic control valve 21 to the piston 18, and is further provided with a brake mechanism 23 that brakes the coupled torque caused by the inertial energy of the clutch body 17. As shown in FIG. 2, the brake mechanism 23 consists of a brake shoe 25 that swings around a pin 24, a piston 26 that operates the brake shoe 25, etc., and by feeding pressure oil from the valve 21, The brake shoe 25 can be pressed.

The one-way clutch mechanism 17 is provided on the input side of the PTO transmission mechanism 15, and specifically, the one-way clutch mechanism 17 is provided on the input side of the PTO transmission mechanism 15.
The rear end of the shaft 13 and the transmission shaft 27 of the PTO transmission mechanism 15
The pawl clutch plate 28 is provided between the second shaft 13 and is slidably fitted onto the second shaft 13 with a spline structure, and the driven pawl clutch plate 29 is attached to the transmission shaft 27. The part is a pawl clutch with a cam that transmits torque only toward the transmission mechanism 15, and the driving clutch plate 28 is a coil spring 30.
The driven pawl is urged toward the clutch plate 29.

The PTO transmission mechanism 15 is composed of a transmission shaft 27 having a gear 31 and a PTO shaft 33 having a transmission gear 32 meshed with the gear 31 so as to be freely rotatable, and can be shifted to two stages through the sliding movement of a shifter 34. A PTO transmission case 35 is attached to the rear end surface of the transmission case 5.

In addition, in the figure, 36 is a lubricating oil path, 37
is a traveling transmission mechanism.

Therefore, in this embodiment, the PTO transmission mechanism 15 is shifted to two stages by the shifter 34, and the hydraulic clutch mechanism 12
When pressure oil is sent to the piston 18 against the unillustrated return spring and the clutch plate 19 is connected, the power of the engine 4 is transmitted and drives the PTO shaft 33 under the required speed change.

If an excessive load is applied while driving the work machine, the driving pawl clutch plate 28 of the one-way clutch mechanism 14
is slid in the cutting direction against the spring 30 to cut off the load, and at the same time, by sending pressure oil to the piston 26 of the brake mechanism 23, the brake system 2
5 to brake the clutch body 17.

This braking of the clutch body 17 is the same when braking the continuous torque during disengagement of the hydraulic clutch mechanism 12.

When the aforementioned load is removed, the one-way clutch mechanism 14 is re-engaged by the spring 30.
Since it is provided before the PTO transmission mechanism 15, the clutch capacity can be reduced.

<Effects of the Invention> According to the present invention, there is provided a hydraulic clutch mechanism 12 provided in the middle of the PTO drive shaft system 10 and a PTO transmission mechanism 15 that is interlocked via the one-way clutch mechanism 14 via the hydraulic clutch mechanism 12. Therefore,
When an abnormal load acts on the PTO shaft 33 side,
This can be interrupted by the one-way clutch mechanism 14, which may reduce the capacity of the brake mechanism 23 that brakes the inertia energy of the clutch body 17 in the hydraulic clutch mechanism 12, and the one-way clutch mechanism 14 can be blocked by the PTO transmission mechanism 15.
Since it is provided on the input side of the clutch mechanism 14,
As a result, the drag torque from the PTO transmission mechanism 15 can be reliably cut off, and the capacity of the brake mechanism 23 can be further reduced.

Therefore, the brake mechanism 23 for continuous rotation torque braking
can be made smaller and can be easily accommodated in the narrow mission case 5.

Furthermore, damage to each transmission system (gears, shafts), etc. can be prevented and durability is improved.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which Fig. 1 is a partially omitted cross-sectional side view, Fig. 2 is an explanatory diagram of a brake mechanism for continuous torque braking, and Fig. 3 is an overall side view of a tractor to which the present invention is applied. It is a diagram. 4...Engine, 10...PTO drive shaft system, 1
2...Hydraulic clutch mechanism, 14...One-way clutch mechanism, 15...PTO transmission mechanism, 17...
Clutch body, 23... Brake mechanism to prevent continuous rotation.

Claims (1)

[Claims] 1. PTO drive shaft system 10 linked to engine 4
In a system in which the PTO transmission mechanism 15 is driven via a hydraulic clutch mechanism 12 provided in the middle of the PTO transmission mechanism 15 to extract power from the PTO shaft 33 of the PTO transmission mechanism 15, the inertia energy of the clutch body 17 in the hydraulic clutch mechanism 12 is braked. A rotation prevention brake mechanism 23 is provided on the PTO drive system shaft 10 between the hydraulic clutch mechanism 12 and the PTO transmission mechanism 15 and on the input side of the PTO transmission mechanism 15.
A power extraction device for a tractor, characterized in that a one-way clutch mechanism 14 that transmits power only toward a transmission mechanism 15 is provided.