JPH0569730B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention provides a mechanism for automatically disconnecting power transmission from the PTO shaft when the working equipment is raised in a tractor equipped with a working equipment that can be raised and lowered. I made it
Regarding PTO auto stop device.

(Conventional technology) In a tractor that is equipped with a rotary tiller or other working machine at the rear of the tractor so that it can be raised and lowered, and power is transmitted from the PTO shaft of the tractor to the working machine, it is possible to till the field and turn the headland. At that time, the tractor was turned after raising the work equipment. When the work equipment was raised during this headland turn, it would be extremely dangerous if the rotary tiller was rotating, so the power to the PTO shaft was cut off by operating the clutch lever. That is, it is necessary to operate the clutch lever at the same time as operating the work implement lifting control lever, which is very troublesome to operate.

In order to simplify the operation, for example, the PTO shaft clutch was automatically disengaged when the working machine rose by a predetermined amount.
It is disclosed in Publication No. 108429.

This conventional PTO auto-stop device connects the lift arm of the hydraulic system for lifting and lowering the work equipment with the PTO clutch using a link mechanism, etc. When the lift arm rises a predetermined amount, the PTO clutch is disconnected, and then lowers to a predetermined position. Then, the same clutch became ``in''.

(Problems to be Solved by the Invention) In the conventional PTO auto-stop device, the PTO clutch is "disengaged" when the work machine is in the ascending position and "engaged" when the work machine is in the descending position, but a problem occurs when the work machine descends. Ta.

In other words, when lowering from a raised position, the rotary work equipment must start rotating before it touches the ground, but because the clutch engages during the descent, the rotary work equipment touches the ground before the rotation has increased sufficiently, resulting in an excessive load on the work equipment. There was a problem with the effect of

Therefore, in the present invention, when the work equipment is raised, the PTO clutch is automatically disengaged, and when the work equipment is in the raised position, the PTO clutch can be independently ``engaged'', and the work is performed before the lowering operation. This is an attempt to solve the above-mentioned problem by putting the machine into a driving state.

(Means for solving the problems) In order to solve the above problems, the present invention takes the following measures. That is, the features of the present invention include a hydraulic device that moves a working machine mounted on a tractor up and down with respect to the tractor, a control lever that controls the hydraulic system, and a control lever that transmits power from the tractor's engine to the working machine. In a device equipped with a PTO shaft, a clutch that turns on/off power transmission of the PTO shaft, and a clutch lever that operates the clutch, when the control lever is placed in the work equipment raising position, the clutch lever is The clutch lever and the control lever are removably connected via a connecting means so that the clutch lever and the control lever are in the "off" position, and the connecting means is connected so that the clutch lever can be operated independently when the control lever is in the working machine raised position. The point is that a release means for releasing the engagement is provided.

(Function) According to the present invention, work is performed by lowering the working machine to the ground, driving the working machine, and towing the working machine with a tractor. The tractor approaches the ridge,
When changing direction, rotate the control lever so that it is in the work equipment raised position. Operation of this control lever activates the hydraulic system and raises the work equipment.

When the control lever is operated, the clutch lever is interlocked through the coupling means and the PTO clutch is disengaged.

Therefore, no power is transmitted to the work machine in the work machine raised position.

As described above, the tractor is turned with the working machine raised and its power cut off. When a turn is completed and you move on to the next task, first operate the clutch lever to turn on the PTO clutch, transmit power from the tractor to the work equipment, and then
Operate the control lever to lower the work equipment.

Therefore, the rotational speed of the working machine is sufficiently increased when it touches the ground, and the grounding can be done smoothly. Once grounding is complete, move the tractor forward and continue work.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

In FIG. 8, 1 is a tractor, and a rotary tiller 2 is attached to the rear of the tractor 1.

The tractor 1 includes an engine 3, a clutch housing 4, and a transmission case 5 that are rigidly connected to form a vehicle body 6, and the vehicle body 6 is supported by front wheels 7 and rear wheels 8.

The engine 3 is covered with a bonnet 9, a pair of left and right rear wheels 8 are covered with fenders 10, and a cabin 11 is placed on the fenders 10.

A hydraulic device 12 for lifting and lowering the work machine is placed on the rear upper surface of the transmission case 5, and the upper part of the hydraulic device 12 is covered with a floor sheet 13, and the left and right edges of the floor sheet 13 are fixed to the fender 10. ing. A driver's seat 14 is arranged on this floor seat 13.

The hydraulic device 12 is provided with a rearwardly projecting lift arm 15 that is rotatable in the vertical direction, and the lift arm 15 is rotated in the vertical direction by a cylinder within the hydraulic device 12. A lift rod 16 is pivotally supported at the rear end of the lift arm 15, and the lower end of the lift rod 16 is pivotally connected to a lower link 17 that is pivotally supported on both left and right sides of the transmission case 5 so as to be rotatable in the vertical direction. There is.

Top link 1 on the rear end surface of the transmission case 5
A three-point link mechanism 19 is constituted by this top link 18 and the pair of left and right lower links 17. The working machine 2 is detachably connected to this three-point linkage mechanism 19.

A PTO shaft 20 protrudes from the rear end surface of the transmission case 5, and the PTO shaft 20 and the input shaft 21 of the working machine 2 are interlocked and connected by a universal joint shaft 22.

The PTO shaft 20 is driven by the engine 3,
A clutch 23 is interposed in the power transmission path within the transmission case 5. This clutch 23
can be turned on and off by swinging the clutch lever 24 located on the right side of the driver's seat 14 in the longitudinal direction.
Be manipulated.

Raising and lowering of the lift arm 15 of the hydraulic system 12 is performed by swinging a hydraulic control lever 25 disposed in front of the clutch lever 24 in the longitudinal direction.

FIG. 1 shows details of the structure of the clutch lever 24 and control lever 25.

That is, the clutch lever 24 is pivotally supported on a plate 26 fixed to the inner surface of the fender 10 via a support shaft 27 so as to be freely rotatable in the front and rear directions. The clutch lever 24 is held in the forward pivoting position I or in the rearward pivoting position by an unstable switching spring 28. At the forward rotational position I of the clutch lever 24, the PTO clutch 23 is in the "on" state, and the power of the engine 3 is transmitted from the PTO shaft 20 to the working machine 2 via the universal joint shaft 22 and the input shaft 21. The rotary tiller 29 of the working machine 2 is rotationally driven. When the clutch lever 24 is in the backward rotation position, the PTO clutch 23 is "disengaged" and the power of the engine 3 is not transmitted to the work implement 2.

The control lever 25 is pivotally supported via a support shaft 32 to a bracket 31 fixed on a base plate 30 fixed on the floor seat 13 so as to be rotatable in the front and rear directions. For this control lever 25, the range shown in the figure is the position control range position, and the position V is the raised position.

That is, by operating the control lever 25 in the position control range position, the lift arm 15 is raised and lowered to a predetermined position and held.
By holding the lift arm 15 at a predetermined position, the working machine 2 is held at a predetermined working position height.

At the raised position V of the control lever 25, the lift arm 15 rises to the highest position, and the work implement 2 is held at the highest position. That is, the work implement 2 is held in this raised position when traveling on the road or turning on a headland.

The control lever 25 and the clutch lever 24 are interlocked and connected by a connecting means 33.

That is, the connecting means 33 is comprised of a push rod 33 etc. which is pivotally supported by the clutch lever 24 in a forwardly projecting manner so as to be freely rotatable in the vertical direction. A midway portion of the push rod 33 is inserted into and held in a long hole 35 of a support plate 34 provided upright on the upper surface of the base plate 30. This long hole 35 is a long hole that is long in the vertical direction. The push rod 33 is vertically swingable within the range of the elongated hole 35.

The tip of the push rod 33 is connected to a stopper 36 protruding from the side surface of the control lever 25.
It contacts and detaches freely. That is, the stopper 36 and the push rod 33 do not come into contact with each other when the control lever 25 is in the range of -V, but they do come into contact with each other when the control lever 25 is in the range of -V.

A push-up lever 37 is pivotally supported on the support plate 34 so as to be swingable in the vertical direction. A push-up pin 38 is fixed to the upper end of the push-up lever 37, and as the push-up lever 37 swings, the push-up pin 38 comes into contact with the push rod 33 and pushes the push rod 33 up within the elongated hole 35. Since the center of gravity of this push-up lever 37 is above the pivot portion, the push-up pin 38 tends to rotate downward, so a stopper pin 39 is fixed to the support plate 34 to prevent the downward rotation. .

The control lever 25 includes a push rod 4 that removably abuts on the lower end of the push lever 37.
0 is fixed. This push rod 40 is used to push up the push lever 3 when the control lever 25 is in the range of
7, but is configured to abut in the range of ~V.

According to the above configuration, when the clutch lever 24 is in the position, the clutch 23 is turned on and the work machine 2 is turned on.
is driven, and the control lever 25 is in the range of ~, and the work implement 2 performs tilling work in the lowered position.

To raise the working machine 2 when turning on a headland or the like, move the control lever 25 to the V position. At this time, the stopper 36 comes into contact with the tip of the push rod 33 at the position , and pushes the push rod 33 rearward. This pushing movement causes the clutch lever 24 to move from the position to the position,
PTO clutch 23 becomes "disconnected". The movement of the clutch lever 24 is as follows when the unstable switching spring 28 passes through the dead center position.
The clutch lever 24 is moved by this spring 28.

When the control lever 25 is moved from V to V, the push rod 40 pushes the push lever 37,
A push-up pin 38 moves the push rod 33 upward. Then, the control lever 25 is turned to V.
In the position , the push rod 33 is located above the stopper 36 and is released from contact therewith. That is, the lever 37, push rod 40, etc. constitute a release means for disengaging the coupling means 33 so that the clutch lever 24 can be operated independently when the control lever 25 is in the working machine raised position.

The contact between the stopper 36 and the push rod 33 is released during the movement of the control lever 25 from V to V, but this release position is set after the unstable switching spring 28 has passed the dead center. Therefore, the clutch lever 24 is moved to the position where it is pulled by the spring 28.

Therefore, when the working machine 2 is in the raised position, the clutch 23 is "disengaged" and power transmission to the working machine 2 is cut off.

Next, when lowering the work implement 2 to move on to the next tilling operation, first move the clutch lever 24 from the position to the position of , turn the clutch 23 into the "on" position, and transmit power to the work implement 2. do. At this time, the push rod 33 is pushed upward by the push-up pin 38 and is located above the stopper 36, so even if the push rod 33 moves forward due to the forward movement of the clutch lever 24, the push rod 33 is pushed upward by the stopper 36. Do not come into contact with the

Thereafter, the control lever 25 is moved from the V position to lower the working machine 2.
As a result, the rotary tiller 29 of the working machine 2 descends in a rotating state and bites into the ground, resulting in a smooth descent.

When the control lever 25 moves forward, the contact between the push rod 40 and the push-up lever 37 is released, and the push-up lever 37 is rotated downward by the weight of the push rod 33 and itself, and is held in contact with the stopper pin 39. Ru. As a result, the push rod 33 also descends and returns to its original state.

In addition, FIGS. 2 to 4 show other embodiments of the present invention,
When moving the control lever 25 from the V position to the lowered position, the push rod 33 can be moved along with the control lever 25.
The clutch lever 24 can be operated independently when the clutch lever 5 is in the V position.

That is, a first stopper 36 and a second stopper 41 are provided on the side surface of the control lever 25 with predetermined gaps in the front-rear and up-down directions, and a collar 42 that can be freely adjusted with a screw is provided at the tip of the push rod 33. , control lever 2
It abuts against the rear surface of the first stopper 36 at the position 5, and abuts against the front surface of the second stopper 41 at the position V. The other configurations are the same as those shown in FIG.

Incidentally, a bracket 43 is attached to the upper part of the engine 3 in the tractor 1.
3, steering control unit 44
, an intake manifold 45, and an accelerator link 46 are attached.

Details of the bracket 43 are shown in FIGS. 5-7.

The accelerator link 46 is rotatably supported by a pin 47 protruding from the bracket 43, the upper end of the link 46 is connected to an accelerator pedal 49 via a push-pull wire 48, and the lower end of the link 46 is connected to an accelerator pedal 49 via a push-pull wire 48. It is connected to a fuel injection lever 51 via a rod 50.

In addition, 52 is a control unit mounting part, 53
54 is an outer wire attachment portion, and 54 is an air cleaner.

Note that the present invention is not limited to the above-mentioned embodiment, but the control lever 25 and the clutch lever 24 are connected by a wire or the like, and when the control lever is moved to the upper position, the clutch lever is moved together by pulling the wire, and the control In the lever raised position, the clutch lever may be operated independently by utilizing slack in the wire.

(Effect of the invention) According to the present invention, automatically
Since the PTO clutch is disconnected and a single PTO clutch can be connected prior to the lowering operation, safety can be ensured and the work equipment can be grounded smoothly.

[Brief explanation of the drawing]

FIG. 1 is a drawing showing an embodiment of the present invention, and is a side view seen from the driver's seat side, and FIGS. 2 to 4 are other embodiments of the present invention, and operational explanatory diagrams showing the main parts thereof. FIG. 5 is a plan view of the bracket, FIG. 6 is an assembly diagram including a front view of the bracket, FIG. 7 is a right side view of the bracket, and FIG. 8 is a front view showing the overall configuration of an embodiment of the present invention. . 1...Tractor, 2...Work machine, 12...Hydraulic system, 20...PTO shaft, 23...Clutch, 2
4...Clutch lever, 25...Control lever, 33...Push rod, 37...Push up lever, 40...Push rod.

Claims (1)

[Scope of Claims] 1. A hydraulic device 12 that moves a working machine 2 mounted on the tractor 1 up and down with respect to the tractor 1, a control lever 25 that controls the hydraulic device 12,
In a vehicle equipped with a PTO shaft 20 that transmits the power of the engine 3 of the tractor 1 to the working machine, a clutch 23 that turns on and off the power transmission of the PTO shaft 20, and a clutch lever 24 that operates the clutch 23, The clutch lever 24 and the control lever 25 are removably connected to each other via a connecting means 33 so that the clutch lever 24 is in the "off" position when the control lever 25 is placed in the working machine raised position; The present invention is characterized in that release means 37 and 40 are provided for disengaging the coupling means 33 so that the clutch lever 24 can be operated independently when the control lever 25 is in the working machine raised position.
PTO auto-stop device.