JPH025805A - Connection device between tractor and work equipment - Google Patents

Abstract

PURPOSE:To prevent slip off between input shaft and connecting shaft of working machine by making a force controlling slip off between input shaft and connecting shaft in the working machine larger than a force controlling slide of extending and contracting part in the connecting shaft. CONSTITUTION:Intermittent part of connecting shaft 34 connecting PTO shaft 7 of tractor 1 and input shaft of working machine R is constructed as extending and contracting part 26 freely sliding in shaft direction. The connecting shaft 34 and said input shaft are possible to engage and remove in slide-free in shaft direction and the connecting shaft 34 is potentialized of elasticity in the direction of engaging with said input shaft. In the connection device having said two sliding parts, sum of a sliding frictional force between the connection shaft 34 and said input shaft in the direction of the shaft and a force elastically potentializing the connecting shaft 34 in the direction of engaging with said input shaft is made larger than a sliding frictional force between the connecting shaft 34 and the extending and contracting part 26 in the shaft direction.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a coupling device for a tractor and a working machine.

(Prior art) As a coupling device between a tractor and a working machine,
There is one proposed in No. 113847.

This includes a connecting body and a connecting shaft, and the connecting body is detachably attached to a working machine and is detachably attached to a tractor via a link mechanism.

Further, the connecting shaft is detachably connected to the PTO shaft of the tractor and the input shaft of the working machine via a universal joint.

As the distance between the PTO shaft and the input shaft changes due to the vertical movement of the work equipment relative to the tractor, and in order to smoothly connect the connecting shaft and the input shaft, the connecting shaft can be expanded and contracted.
A midway portion of the connecting shaft is slidable in the axial direction via a spline or the like.

Further, the connection shaft and the input shaft of the working machine are connected to each other by being slidably fitted and removed in the axial direction via a spline or the like.

In order to perform this mating and unmating smoothly, the connecting shaft is supported with respect to the connecting body so that the position can be changed freely between the mating position with the input shaft and the uncoupling position. An elastic body is provided that biases in the fitting direction.

(Problems to be Solved by the Invention) In the conventional type, the frictional force of the axial sliding part in the middle of the connecting shaft is large during torque transmission, so when the work equipment moves up and down with respect to the tractor, the connecting shaft However, there is a problem in that the input shaft does not shrink in the middle and changes its position with respect to the connecting body in the direction of removal from the human power shaft, causing the input shaft to separate from the connecting shaft.

In particular, when the torque transmitted from the PTO shaft to the input shaft is large, the frictional force that restricts axial sliding in the middle of the connecting shaft becomes large, and this problem becomes significant.

The present invention aims to solve the above problems.

(Means for Solving the Problems) The present invention is characterized by a coupling device for coupling the tractor 1 and the working machine R, which includes a coupling body 14 and a coupling shaft 34.
The connecting body 14 is removably attached to the working machine R, and is also detachably attached to the tractor 1 via the link mechanism 9, and the connecting shaft 34 has a universal joint 35 at both ends.
．． 36, the middle part is an extensible part 26 that is slidable in the axial direction, the connecting shaft 34 and the PTO shaft 7 of the tractor 1 are removably connected, and the connecting shaft 34 and the input shaft 27 of the work aR are connected. The connecting shaft 34 is slidably fitted in and removably in the axial direction, and the connecting shaft 34 is supported to the connecting body 14 so as to be changeable between a fitting position with the input shaft 27 and a disengaging position. In a coupling device for a tractor and a working machine, in which the coupling body 14 is provided with an elastic body 29 that biases in the direction of engagement with the human power shaft 27, axial sliding between the coupling shaft 34 and the input shaft 27 is provided. The frictional force that regulates the
7 is greater than the frictional force that restricts the axial sliding of the extendable portion 26 of the connecting shaft 34.

(Function) When the work implement R moves up and down with respect to the tractor 1, the connecting shaft 34
A force that attempts to slide the extensible portion 26 in the axial direction and a force that attempts to slide the connecting shaft 34 and the input shaft 27 in the axial direction act.

In this case, the axial frictional force between the connecting shaft 34 and the input shaft 27 and the biasing force of the elastic body 29
7 and restricts axial sliding in the removal direction.

Further, the axial frictional force of the telescopic portion 26 of the connecting shaft 34 restricts the contraction of the connecting shaft 34.

Therefore, in the present invention, when the working machine R moves up and down, the telescopic portion 26 of the connecting shaft 34 contracts, and the connecting shaft 34 does not move in the direction of detachment from the input shaft 27 with respect to the connecting body 14.

(Example) Embodiments of the present invention will be described below based on the drawings.

In Fig. 4, 1 is a tractor, 2 is a tractor body, and 3 is a tractor.
1 is a hydraulic device for elevating and lowering a work machine, which is exemplified as a lifting device mounted on the rear part of a tractor body 2, and has a pair of left and right lift arms 4. 5 is a seat, 6 is a rear wheel, and 7 is a PTO shaft, which protrudes rearward from the rear end of the vehicle body 2.

Reference numeral R denotes a side-drive two-row tiller, which is exemplified as a working machine, and is connected to the rear of the tractor I via a three-point linkage mechanism 9 and a connecting device so as to be movable up and down and detachable.

As shown in FIGS. 4 to 6, this tilling device R includes a top mast 49 projecting upward from an input case 48, a pair of support arms 51 projecting left and right from the input case 48, It includes a pair of left and right brackets 52 protruding forward from the middle part of each support arm 51 in the left and right direction, and a transmission case 53 and a side plate attached to the outer end of each support arm 51. A tilling shaft is provided which is horizontally suspended between the transmission case 53 and the lower end of the side plate and is driven to rotate.A tilling section 54 is configured by attaching a large number of tilling claws to this tilling shaft. A tillage cover 55 that covers the section 54, a pair of left and right gauge wheels 56, a tillage depth adjustment mechanism 57 for raising and lowering the gauge wheels 56, and the like are provided.

The input case 48 is provided with an input shaft 27 that projects forward.

The three-point link mechanism 9 includes a top link 10 in the center and a pair of lower links 11 on the left and right sides, and the lower links 11 and the lift arm 4 are connected by a lift rod 12.

The connecting device includes a connecting body 14 and a connecting shaft 34.

As shown in FIGS. 4 to 7, the connecting body 14 is constructed of a main body 15 having a mountain-like shape when viewed from the front, a bridge member 16 that connects both left and right sides of the main body 15, and a bridge member 16. body 15
It has mounting plates 17 fixed to both left and right sides of.

A pair of left and right mounting portions 18 are provided at the upper end of the main body 15.
A pair of left and right receiving members 19 extend rearward from both left and right ends of the main body 15 .

The rear end of the top link 10 is removably connected between the front parts of the attachment part 18 by a pin 22. Each mounting part 18
A notch is formed in the rear portion of the holder to form an engaging portion 23 that opens upward.

Each receiving member 19 has a rear end of the lower link 11 attached to the bin 2.
It is removably pivoted via 0. Further, each receiving member 19 is formed with an upper engaging portion 24 that opens rearward. At the upper part of the top mast 49 of the tilling device R, there is an upper connecting shaft 58 that removably engages with the first retaining part 23.
are provided in the left and right direction, and at the front of both brackets 52,
A pair of left and right lower connecting shafts 59 are provided that detachably engage with the rain retaining portion 24 .

As shown in FIGS. 1 to 4, the connecting shaft 34 is provided with universal joints 35, 36 at the front and rear ends, and the universal joints 35, 36
The front end is removably spline-fitted to the PTO shaft 7, and the rear end is spline-fitted to the human power shaft 27 so as to be slidable in the axial direction and removable.

Further, the connecting shaft 34 includes a front connecting shaft 34a and a rear connecting shaft 3.
4b are spline-fitted to each other, so that the midway portion thereof forms an extensible portion 26 that is slidable in the axial direction.

The rear universal joint 36 consists of front and rear yokes 37, 38, and a spider 39 that connects both yokes 37, 38.

The front yoke 37 is detachably attached to the connecting shaft 34.

A female spline portion 42 is formed on the rear inner surface of the rear yoke 38 and is slidably fitted into and removed from the male spline portion 41 of the input shaft 27 in the axial direction.

The rear yoke 38 has a bearing 4 on the circumferential surface of the mounting tube 28.
Supported through 0. The mounting tube 28 is loosely inserted into a mounting hole 21 opened in the mounting plate 17 of the connecting body 14 with its axis centered at the front and rear.

A ring-shaped spring receiving portion 30 that projects radially outward is integrally formed at the rear end of the mounting tube 28, and a retaining ring 31 serving as a stopper to prevent removal from the mounting hole 21 is provided at the front end. A washer 32 is removably fitted on the outside.

A coil spring 29 is fitted onto the mounting tube 28,
The front end of this coil spring 29 is in contact with the mounting plate 17, and the rear end is in contact with the spring receiver 30. As a result, the connecting shaft 34 is supported by the connecting body 14 through the mounting tube 28, and due to the elastic force of the coil spring 29, the connecting shaft 34 is supported through the mounting tube 28.
4 is biased rearward with respect to the connecting body 14. The coil spring 29 is formed so that its outer diameter gradually increases toward the front end.

Reference numeral 60 denotes a pair of left and right locking devices, which are provided on each receiving member 19 and releasably prevent the lower connecting shaft 59 from coming off the upper engaging portion 24 . This locking device 60 includes a cylindrical body 61 erected on the receiving member 19, a retaining pin 62 inserted into the cylindrical body 61 and the upper engaging portion 24, and a retaining pin 62 inserted into the cylindrical body 61 and the upper engaging portion 24.
It has a biasing spring 63 that biases downward. In addition, at the position where the retaining pin 62 is withdrawn from the upper engaging portion 24, a fixing plate 64 that is releasably engaged with the lower surface of the handle 44 of the retaining bottle, and a receiving member 19 are pivotally supported. and the stopper bottle 62
There is a regulating body 65 that releasably holds the body in the removed position, and a spring 66 that biases the regulating body 65 in the regulating direction.

To connect the tilling device R to the tractor 1, first place the tilling device R on the ground, as shown in FIG.
A coupling device attached to the three-point linkage mechanism 9 and the PTO shaft 7 is located at the lower front of this tilling device. At this time, the locking device 60 is prevented from being removed, and the pin 62 is pulled up and held by the regulating body 65.

Next, the coupling device is raised by the lift arm 4 via the three-point linkage mechanism 9. Thereby, the upper connecting shaft 58 of the tilling device R is engaged with the upper engaging portion 23 of the connecting body 14, and the lower punching portion 24 and the lower connecting shaft 59 are made to face each other in the front and back directions.

Further, as shown in FIG. 2, the rear yoke 38 at the rear end of the connecting shaft 34 and the input shaft 27 are opposed to each other.

When the connecting device is further raised from this state, the tilling device R is lifted via the upper engaging portion 23 and swings forward around the upper connecting shaft 58. As a result, as shown in FIG. The lower connecting shaft 59 is inserted and removed from the lower punching portion 24 .

In addition, as shown in FIG.
The male spline part 41 and the female spline part 42 are inserted into the inside of the spline part 42, and the male spline part 41 and the female spline part 42 are engaged with each other. At this time, the mounting tube 28 is attached to the mounting plate 1.
Since it is loosely inserted into the mounting hole 21 of No. 7, even if the axes of the male spline portion 41 and the female spline portion 42 are misaligned,
The movement of the mounting tube 28 with respect to the mounting hole 21 corrects the misalignment of its axis. Further, if the outer spline portion 41 and the female spline portion 42 do not match in the circumferential direction, the mounting tube 28 and the rear connecting shaft 34b are pushed forward against the elastic force of the spring 29, but the PTO If the shaft 7 is rotationally driven to correct the circumferential deviation of both spline parts 41 and 42, the elastic force of the spring 29 will cause the mounting cylinder 28 and the rear connecting shaft 3 to
4b moves rearward, and both spline parts 41 and 42 are engaged.

When plowing work is performed by the plowing device R connected to the tractor 1 as described above, power is transmitted from the PTO shaft 7 of the tractor 1 to the input shaft 27 of the plowing device R via the connecting shaft 34. When the tilling device R moves up and down with respect to the tractor 1 during work, the distance between the PT○ shaft 7 and the human power shaft 27 changes. If this interval becomes smaller, there is no problem because the connecting shaft 34 is reduced in the axial direction by the extensible portion 24. However, if the gap becomes large, not only will the telescopic portion 34 of the connecting shaft 34 try to expand in the axial direction (but also the mounting tube 28 at the rear end of the connecting shaft 34 will try to move forward with respect to the connecting body 14). .

The force that prevents the connecting shaft 34 from expanding is
This is a frictional force F that restricts axial sliding at the spline fitting portion between the front connecting shaft 34a and the rear connecting shaft 34b.

On the other hand, the mounting tube 28, that is, the connecting shaft 34 is connected to the connecting body 14.
The force that prevents the spring from moving forward is the rear biasing force F2 of the spring 29 against the mounting tube 28, the female spline portion 42 of the rear yoke 38, and the male spline portion 41 of the input shaft 27.
It is the sum of the frictional force F3 that restricts the axial sliding movement.

If Fl > l? , −+−p, if the relationship holds, then
The connecting shaft 34 does not extend, and the rear end side of the connecting shaft 34 is connected to the connecting body 1.
4, the input shaft 27 is moved forward from the rear yoke 38 as shown by the imaginary line in FIG. 1, and the tilling operation becomes impossible. Therefore, Fl<Fz+
The relationship is said to be F3. As a result, the connecting shaft 3
4 extends at the telescopic portion 26, and the rear end of the connecting shaft 34 connects to the input shaft 2.
The fitted position with 7 is maintained.

Specifically, various means can be considered to establish the relationship Fl<F2+F1.

For example, the frictional forces F1 and F3 between the telescopic portion 26 of the connecting shaft 34 and the spline portions 41 and 42 are both proportional to the circumferential force acting on the spline teeth and the friction coefficient between the spline teeth in the circumferential direction. In other words, the transmission torque is T, the telescopic part 2
If the friction coefficient in the circumferential direction of the spline teeth of No. 6 is μm, the average diameter of the torque transmission part is 02, the friction coefficient in the circumferential direction of the spline teeth of spline parts 41 and 42 is μ2, and the average diameter of the torque transmission part is D2. , F, is proportional to 2μ+'r/paste, and F2 is proportional to 2μ2T/DZ. Therefore, by making D+ larger than D2 as shown in the first diagram, Fl
<Fz+F:l. In addition, a lubricant is sealed between both splines of the extensible part 26, and μ2>μ
It may be made to be m. Note that F2 may be increased by increasing the biasing force of the spring 29, but as described above,
If the male and female spline portions 4L42 are misaligned in the circumferential direction when the human power shaft 27 is inserted into the rear yoke 38 when connecting the tilling device R and the connecting device, forward movement of the mounting tube 28 may be hindered. It is necessary to apply a certain amount of biasing force.

In addition, in order to remove the tilling device R from the coupling device, first pull up the retaining pin 62 of the locking device 60 and lock the handle 44 to the fixing plate 64 as shown by the imaginary line in FIG.
The retaining pin 62 is locked in the position removed from the upper engaging portion 24.

In this state, the hydraulic device 3 lowers the coupling body 14 and the tilling device P, and the tilling portion 54 of the tilling device R is brought into contact with the ground.

Then, if the connecting body 14 is further lowered, the tilling device R
rotates around the upper connecting shaft 58 and tilts forward, and first, the connecting body 1
The lower connecting shaft 59 of the tilling device R is removed from the upper engaging portion 24 of 4, and the input shaft 27 is removed from the rear yoke 38.

Then, if the connecting body 14 is further lowered, the connecting body 14
The upper connecting shaft 58 of the tilling device R is relatively disengaged from the upper engaging portion 23 upwardly.

Thereby, the work of removing the tilling device R from the tractor 1 is completed.

(Effects of the Invention) According to the present invention, the frictional force that restricts the axial sliding between the connecting shaft and the input shaft, and the elastic body that urges the connecting shaft in the direction of fitting the input shaft with respect to the connecting body. The sum of the biasing force is greater than the frictional force that restricts the axial sliding of the extendable part of the connecting shaft, so even if the work equipment moves up and down relative to the tractor during work, the connecting shaft will extend and the input shaft will will not come off from the connecting shaft.

[Brief explanation of the drawing]

The drawings relate to embodiments of the present invention, and FIG. 1 is a cross-sectional view showing the connected state of the connecting shaft and the input shaft, FIG. 2 is a cross-sectional view showing the same extraction and removal state, and FIG. 3 is the rear end of the connecting shaft. Fig. 4 is a side view of the tractor, coupling device, and working machine, Fig. 5 is a side view of the coupling device and working machine in a connected state, and Fig. 6 is a side view of the same in a disconnected state. 7 are front views of the coupling device. 1... Tractor, R... Tilling device, 7... PTO
Shaft, 9... Three-point link mechanism, 14... Connecting body, 26
... Telescopic part, 27 ... Input shaft, 29 ... Elastic body,
34...Connection shaft, 35.36...Universal joint. Hanging 3 Diagram

Claims (1)

[Claims] (1) A coupling device that connects the tractor 1 and the working machine R, and includes a coupling body 14 and a coupling shaft 34. The coupling body 14 is detachably attached to the working machine R, and the link mechanism 9 is attached to the coupling body 14. The connecting shaft 34 is detachably attached to the tractor 1 via the connecting shaft 34, and is provided with universal joints 35 and 36 at both ends.
The middle part is an extensible part 26 that is slidable in the axial direction, and the connecting shaft 3
4 and the PTO shaft 7 of the tractor 1 are removably connected,
The connecting shaft 34 and the input shaft 27 of the work machine R are fitted together so as to be able to slide freely in the axial direction and to be fitted in and out. The connection shaft 34 is supported by the input shaft 2 with respect to the connection body 14 so as to be freely repositionable.
In a coupling device between a tractor and a working machine, which is provided with an elastic body 29 that urges the coupling shaft 34 and the input shaft 27 in the fitting direction, the friction force that restricts the axial sliding between the coupling shaft 34 and the input shaft 27, and the elastic body The sum of the force that urges the connecting shaft 34 of No. 29 in the fitting direction with the input shaft 27 is larger than the frictional force that restricts the axial sliding of the extendable portion 26 of the connecting shaft 34. A coupling device between a tractor and a working machine.