JPH04113935A - Pto clutch structure for work vehicle - Google Patents

Abstract

PURPOSE:To obtain a PTO clutch structure for a work vehicle, in which joint connecting work of a PTO shaft to a working device can be carried out safely and easily, thereby giving great advantages in practical use, by additionally arranging a check valve in a pressure oil supplying passage of the control valve of a PTO clutch. CONSTITUTION:A control valve 34 used for a PTO clutch 15 is provided with a pressure oil supply position F and a pressure oil discharge position S, while a pressure oil supplying passage 36 to the control valve 34 is provided with a check valve 37 which allows the pressure oil to flow into the control valve 34. In addition, an engine oil pressure switch 38, which detects whether an engine E is started or not, a pressure switch 40, which detects ON/OFF condition of a PTO clutch 15 located in an oil passage 39 led to the PTO clutch 15, and alarming buzzer 41 are electrically wired together in series. When the engine E is stopped after plating the PTO clutch 15 in engagement although manual joint connection of the PTO shaft 3 to a working device is required, an alarming mechanism A is also operated so as to ring the buzzer 41.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a hydraulically operated PTO clutch that engages when pressure oil is supplied and disengages when the oil is drained, as part of a PTO transmission mechanism. A brake device is provided at the downstream side of the transmission and is capable of braking the rotating member on the driven side of the PTO clutch, and this brake device is operated to perform a braking operation when the PTO clutch is disengaged, and when the PTO clutch is engaged. Accordingly, the present invention relates to a PTO clutch structure for a working vehicle that is linked to a state in which the brake is released.

[Conventional technology]

In the PTO clutch structure of this type of work vehicle, in order to prevent the work equipment from being driven due to the entrainment phenomenon caused by the viscosity of the hydraulic oil even if the PT○ clutch is disengaged, the return spring is closed when the PTO clutch is disengaged. A brake is provided that applies contact resistance to the driven rotating member on the working device side using urging force to brake the driven rotating member.

[Invention or problem to be solved]

Normally, the PTO shaft □ and the input shaft on the working device side are interlocked and connected via a joint, and the connection work is performed when the engine is stopped for safety reasons.

To connect the joint, the PTO shaft is often turned slightly by hand to match the phase in order to fit the spline at the end of the shaft, but in the prior art, when the engine is stopped, the PTO clutch The brake was working regardless of whether it was on or off, making it impossible to turn the PTO shaft by hand, making it difficult to attach and detach the joint. (If the engine is starting, engage the PTO clutch to release the brake system, and operate the Pro transmission mechanism in neutral to shift the PTO
Although it is possible to allow the O-axis to freely rotate, this method is not used to prevent dangers such as unexpected Pro gear shifting operations. ) The present invention aims to solve the above-mentioned problems.

[Means to solve the problem]

In order to achieve the above object, the present invention provides, in the PTO clutch structure for a work vehicle described at the beginning, a control valve for the PT◯ clutch at a supply position where pressure oil is supplied to the PTO clutch; The present invention is characterized in that an oil drain position is provided at which the clutch is in an oil draining state, and a check valve is provided in the pressure oil supply path to the control valve to allow pressure oil to flow into the control valve. .

[For production]

According to the above configuration, when the control valve of the PTO clutch is set to the pressure oil supply position where the clutch is engaged, the PTO clutch is engaged and the brake device is brought into a braking release state. If the engine is stopped in this state, the hydraulic pump will also stop, but the check valve provided in the pressure oil supply path of the control valve maintains the state in which pressure oil is supplied.
The TO clutch is engaged to maintain the brake release state of the brake device. Is it okay to take PTO at this time or around this time?
When the transmission mechanism is operated in neutral, the result is that the PTO clutch is engaged but in neutral operation, and the brake system is not working, so the PTO shaft is in a free rotating state.
In this state, the PTO shaft can be turned by hand to connect the joint.

If the PTO clutch is disengaged and operated before starting the engine again, it is possible to prevent the working device from being driven at the same time as the engine starting.

〔Effect of the invention〕

Therefore, by simply adding a check valve to the pressure oil supply line of the PTO clutch control valve, there is a great practical advantage of being able to safely and easily connect the PTO shaft to the working equipment at the joint. We were able to provide a PTO clutch structure for a work vehicle.

〔Example〕

Below, a case will be described in which an embodiment of the present invention is applied to an agricultural tractor, which is an example of a working vehicle.

Fig. 5 shows an agricultural tractor. An engine (E) is arranged in the front part of the body of this tractor, a control part (1) is provided in the center part, and the engine (E) is provided in the center part.
The transmission case (M) that transmits the power of the engine (E) to the rear wheels (2) and the PTO shaft (3), or the transmission case (M), which also serves as the fuselage frame, is directly connected to the engine (E) and is arranged facing forward and backward.

The control section (1) is equipped with a handle (4) and a step board (6).
The mission case (
M) is located.

As shown in FIG. 2, the inside of the mission case (M) is roughly divided into three compartments (7) in the front and rear direction.

(8) and (9), and the front section (7) contains the main gear transmission mechanism (1o) for the driving system, the gear transmission mechanism (11) for the PTO system, and the forward/reverse transmission mechanism for the PTO system. Mechanism (12
), and the intermediate compartment (8) is equipped with a forward/reverse transmission mechanism (13) for the traveling system, and a hydraulic type for changing the speed of the transmission mechanism for the traveling system on the downstream side of the transmission from this forward/reverse transmission mechanism (13). Variable speed clutch (14) and hydraulic PTO clutch (
15), and the rear compartment (9) is equipped with an auxiliary gear transmission mechanism (16) for the driving system, a super reduction mechanism (17), and a differential transmission for driving the rear wheels (2) that receive the final shifting power of the driving system. Mechanism (1
8) and a rear axle (35) that supports the rear wheels (2).

The mission case (M) is directly connected to a clutch case part (19) at the rear of the engine (E), and via a hydraulic main clutch (C) provided in the clutch case part (19), Main shaft (20) in said front compartment (7)
Power is transmitted to.

Although the arrangement is not shown, there is a PT on the right side of the main shaft (20).
The O-system transmission shaft (21) and the PTO-system reversing shaft (22) are arranged in parallel with the traveling system transmission shaft (23) on the left side, and the main shaft (20) and the traveling system transmission shaft (23) are arranged in parallel. 23)
The main gear transmission mechanism (10) is installed across the main shaft (20) and the PTO system transmission shaft (21), and the gear transmission mechanism (11) is installed across the main shaft (20) and the PTO system transmission shaft (21).

That is, the main shaft (20) is equipped with a gear (G4), an intermediate gear (G5), a third gear (G3), and a second gear (G2) in order from the front.
and the first gear (Gl) are each equipped to rotate integrally,
The drive system transmission shaft (23) has 4th gear (G9) in order from the front.
), 3rd speed gear (G8), 2nd speed gear (G7), and 1st speed gear (G6) are each fitted loosely on the outside, and the PTO system transmission shaft (2
1) includes, in order from the front, 3rd gear (G12), 4th gear (G13), 2nd gear (Gll), and 1st gear (
GIO) are fitted loosely on the outside, and the main gear transmission mechanism (
10) is a hydraulically operated synchromesh mechanism having two transmission members (24), (24), and a gear transmission mechanism (1).
1) is constituted by a mechanically operated constant mesh mechanism which also serves as a transmission member such as a fourth gear (G13) and a second gear (Gll).

and the 1st, 2, and 3rd gear (Gl) of the main shaft (20).

(G2) and (G3) are the 1st, 2nd and 3rd speed gears (
G6).

(G7), (G8) and PTO system 1st, 2, 4th gear (GIO), (Gll), (G13) are configured as dual-purpose gears that engage with each other in this order, due to the speed ratio. Drive system 4th gear (G9) and PTO system 3rd gear (
G12) is configured so that a fourth gear (G4) and an intermediate gear (G5) of a separately prepared main shaft (20) engage with each other.

In addition, a reversing gear (G14) that can engage with the second gear (G2) is slidably fitted onto the reversing shaft (22) to form a forward/reverse transmission mechanism (]2). Gear (G
14) and engages both the second gear (G2) and the second speed gear (Gll), a reverse state can be obtained.

The power that has passed through the PTO clutch (15) is transferred to the intermediate shaft (2
5) is transmitted to a working device (not shown) via the PTO shaft (3).

As shown in Fig. 3, the PTO clutch (15) has an inner body (2
6) and an outer body (27) externally fitted with a spline on the intermediate shaft (25), which engages the clutch when pressure oil is supplied and disengages the clutch when the oil is drained. At the same time, a clutch piston (2) is attached to the cylindrical shaft portion (27a) of the outer body (27).
A pressure oil passage (29) for pressing operation (8) and an oil passage (30) for clutch lubrication are formed.

The PTO clutch (15) is equipped with a brake device (B) that releases braking when the clutch (15) is engaged and operates the brake when the clutch (15) is disengaged.

That is, as shown in FIG. 4, a brake piece (31) that is pushed and pulled by hydraulic pressure is arranged facing the outer body (27), which is a rotating member on the driven side, and a return spring ( 32) presses the brake piece (31) into contact with the outer body (27). In addition, (33) is a hydraulic cylinder for brakes,
(33a) is a piston.

Further, as shown in FIG. 1, the control valve (34) for the PTO clutch (15) is set to a supply position (F) in which pressure oil is supplied to the PTO clutch (15), and
In addition to providing respective oil drain positions (S) where the clutch (15) is in the oil drain state, a pressure oil supply path (36
) is equipped with a check valve (37) that allows pressure oil to flow into the control valve (34). Furthermore, the engine (E)
The engine oil pressure switch (38) detects whether or not the PTO clutch (15) is activated.
39), a pressure switch (40) that detects the on/off state of the PTO clutch (15), and an alarm buzzer (4).
1) are electrically wired in series to form an alarm mechanism (A) that sounds a buzzer (41) when the engine (E) is stopped and the PTO clutch (15) is engaged.

In other words, the PTO system transmission mechanism (D) such as the gear transmission mechanism (11) is operated in neutral, and the PTO clutch (15) is engaged and operated while the engine (E) is running. ), the P
The joint is connected by turning the TO shaft (3) by hand, but at the same time the alarm mechanism (A) is activated and the buzzer (41) is activated.
) sounds, and if the engine is started again in that state, the working equipment (for example, the rotary tiller) will also be activated to alert the operator that there is a danger.

[Another example]

The present invention may be applied to lawn mowers and transport vehicles equipped with a PTO shaft.

It should be noted that the present invention is not limited to the structure of the attached drawings by adding numerals in the claims for convenient comparison with the drawings.

[Brief explanation of drawings]

The drawings show an embodiment of the PTO clutch structure for a working vehicle according to the present invention, and FIG. 1 shows the operation system of the clutch, and FIG.
3 is a sectional view showing the structure of the transmission device, FIG. 3 is a sectional view showing the structure of the PTO clutch, FIG. 4 is a view showing the brake device, and FIG. 5 is a side view of the tractor. (15)...PTO clutch, (27)...
... Rotating member, (34) ... Control valve, (36
)... Pressure oil supply path, (37)... Check valve, (B)... Brake device, (D)...
...PTO transmission mechanism, (F) ...supply position, (S) ...oil drain position.

Claims (1)

[Claims] A hydraulically operated PTO clutch (15
) is provided on the lower transmission side of the PTO transmission mechanism (D), and a brake device (B) capable of braking the driven side rotating member (27) of the PTO clutch (15) is provided, and this brake device (B) ) to the PTO clutch (1
5) A PTO clutch structure for a working vehicle that is linked to a state in which braking is activated when the PTO clutch (15) is turned off and brake is released when the PTO clutch (15) is engaged, The control valve (34) is provided with a supply position (F) where pressure oil is supplied to the PTO clutch (15) and an oil drain position (S) where the PTO clutch (15) is drained. At the same time, a pressure oil supply path (36) to the control valve (34) is connected to the control valve (34).
4) A PTO clutch structure for a work vehicle equipped with a check valve (37) that allows pressure oil to flow into the work vehicle.