JPH081609Y2 - Hitch device in tractor - Google Patents

Description

[Detailed description of the device] (a) Fields of industrial use A hitch frame is attached to the rear part of the machine body via a link so that it can be raised and lowered, and the front part of the yoke joint is connected to the PTO shaft protruding from the rear part of the machine body. The present invention relates to a hitch device for a tractor in which a rear portion of the yoke joint is supported by a hitch frame and is attached to and detached from an input shaft of a working machine via a clutch.

(B) Prior art As a hitch device that attaches and detaches the other end of the yoke joint, one end of which is connected to the PTO shaft of the tractor, to the input shaft of the working machine.
It has already been proposed that the rear joint with the yoke joint is supported by a hitch frame, and the front clutch is attached to the rear clutch of the input shaft.

(C) Problems to be solved by the invention In the hitch device of the tractor, when the front clutch and the rear clutch are centered and engaged with each other, the centering is not smooth, and the tractor and the hitch frame form a pair. Although it has a fixed structure, there are various work machines attached to it, and if a rear clutch is installed for each work machine, the cost will be high and if the rear clutch differs depending on the manufacturer, it cannot be attached to or removed from the front clutch. There was a problem.

(D) Means for solving the problem The present invention connects the hitch frame 5 to the rear part of the machine body via a link so as to be able to move up and down, and connects the front part of the yoke joint to the PTO shaft protruding from the rear part of the machine body. In a tractor in which a rear part is detachably connected to an input shaft of a working machine via a clutch, a transmission shaft is connected to a rear joint of the yoke joint and a rear part of the tractor is projected, and a protruding part of the transmission shaft is elastically connected. A front clutch having a centering hole at the rear end of the transmission shaft, which is held by the hitch frame via a machine so that its meshing portion is separated rearward from the ammunition machine; A rear clutch that has a centering pin that engages and disengages with the centering hole of the front clutch is detachably attached to the front clutch by a magnet, and the rear clutch is Push to the clutch side The above-mentioned problem was solved by providing a spring for biasing the protrusion and covering the outer circumference of the spring with a bellows boot.

(E) Action When connecting the work machine to the hitch frame, hang the upper connection part of the hitch frame on the upper connection part of the work machine and lift the work machine, with the upper connection part as the center and the lower part facing the hitch frame. It rotates and the lower connecting portion is brought into a connected state. In the process, the centering pin of the input shaft of the working machine is fitted into the centering hole of the transmission shaft to be centered, and the front clutch is engaged with the rear clutch.

Then, when the centering pin is fitted into the centering hole for centering, the meshing part between the front clutch and the rear clutch is located behind the part where the transmission shaft is supported by the hitch frame through the ammunition. Since the front clutch cooperates with the transmission shaft against the centering pin against the bullet, the front clutch can be smoothly centered without difficulty.

Further, when connecting the other working machine to the hitch frame, the rear clutch and the centering pin can be removed and easily mounted on the input shaft of the other working machine.

(E) Embodiment An embodiment of the present invention will be described with reference to the drawings. Reference numeral 1 denotes a tractor mission case, in which front ends of a lower link 2 are pivotally attached to both sides of a lower part thereof, and a top link bracket 3 fixed to an upper part thereof is attached to the top link bracket 3. Has a front end of a top link 4 pivotally attached thereto, and a hitch frame 5 is connected to the rear ends of the top link 4 and the lower links 2, 2 by pins 2a, 2a.

The hitch frame 5 includes an inverted U-shaped hitch frame 6, an upper connecting plate 7 formed of an upward hook fixed to the center of the upper part of the hitch frame 6, and a groove fixed to the lower ends on both sides and open to the rear.
It is composed of a lower connecting plate 8 having 8a and a plate-like bracket 10 having a U-shaped cross section, which connects the lower ends of the hitch frames 6.

An arm 14 having an upper connecting pin 15 is attached to the top mast 13 of the rotary tiller 12, which is illustrated as a working machine,
A lower connecting pin 17 that is inserted into the groove 8a of the lower connecting plate 8 is fixed to the front portion of the lower mast 16.

Also, the PT protruding from the rear surface of the mission case 1
The front joint 20a of the yoke joint 20 is connected to the O shaft 19, and the transmission shaft 22 is spline-fitted into the center hole of the rear joint 20b so as to project rearward, and the projecting portion is supported by the hitch frame 5. ing.

To explain the support structure of the transmission shaft 22 in more detail, the front end clutch 21 is fitted and welded to the outer periphery of the rear end of the transmission shaft 22 to connect the front clutch 21 and the rear joint 20b of the transmission shaft 22. A holder 25 having a circumferential groove in between, with a bearing 26 in between.
The holder 25 is fixed to the bearing 26 with a retaining ring 23, and a buffer ring (ammunition machine) 27 made of an elastic material such as rubber and having a cut is fitted in the circumferential groove of the holder 25. The cap 28, which is superposed on the outer periphery of the buffer ring 27, is screwed to the bracket 10 by means of bolts 30 ..., The rear end of the buffer ring 27 and the front clutch 21 are separated by L. Therefore, the transmission shaft 22 elastically tilts vertically and horizontally while expanding and contracting the buffer ring 27 with respect to the bracket 10, that is, the hitch frame 5.

Further, the cylinder shaft 32 is fitted to the input shaft 31 of the rotor tilling device 12 so as not to rotate but to be insertable / detachable (spline fitting in this embodiment). The spline is slidably fitted and the rear end is pushed out by a spring 37 received by a snap ring 35 and a washer 36, and a conical centering pin 38 is attached to the front part of the inner circumference.
A magnet 40 is attached to the end face of the input shaft 3 and attracts the centering pin 38.

When the magnet 40 is removed, or in addition to this, an oil seal 50 is adhered to the rear end of the cylindrical shaft 32 as shown in the figure, and the inner peripheral surface of the oil seal 50 is pressed against the outer peripheral surface of the input shaft. When attaching and detaching, especially when removing, the rear clutch 33 does not pull out together with the cylinder shaft 32, and when replacing the work machine, the rear clutch 33 and the centering pin 38 are attached to the cylinder shaft 32. It can be pulled out and easily attached to the input shaft of another work machine. The same purpose can be achieved by replacing the oil seal 50 with an O-ring made of an elastic material.

Further, when bellows-shaped boots 51 are adhered to the outer circumference of the rear clutch 33 and the outer circumference of the washer 36 to cover the outer circumference of the spring 37 and the rear outer circumference of the cylinder shaft 32, the splines of the spring 37 and the cylinder shaft 32 are covered with mud. Therefore, the expansion and contraction operation of the spring 37 and the forward / backward operation of the rear clutch can be smoothly performed.

In the tractor described above, when the rotary tiller 12 is connected to the hitch frame 5, the lower arms 2 and 2 are lifted and rotated by the lift arm 41 via the lift rod, and the upper connecting pin 15 is attached to the upper connecting plate 7. When hung up and lifted, the rotary tiller 12 rotates about the upper connecting pin 15 such that the lower part moves forward, so that the lower connecting pin 17 enters the groove 8a of the lower connecting plate 8. At that time, since the lower connecting pin 17 fits into the groove of the hook plate 42 whose upper part is pivotally attached to the lower connecting plate 8, the hook plate 42 rotates forward and the cam 43 serving as a lock member is hooked by the hook plate 42. The operation lever 44, which is integrated with the cam 43, moves to the rear end of the guide groove of the lever guide 45 by engaging with the step portion of the upper front side of the lock lever.

In the process of connecting the lower connecting pin 17 to the lower connecting plate 8 as described above, the centering pin 38 is easily inserted into the centering hole of the front clutch 21 to be centered, and the rear clutch 33 is connected to the front clutch 21. Mesh with. At that time, the centering pin 38 often enters from a slightly oblique direction with respect to the centering hole, but in such a case, the front clutch 21 receives a vertical acting force behind the buffer ring 27, The front clutch 21 and the transmission shaft 22 are tilted so that the centering operation is smoothly performed.

When the rotary cultivator 12 is removed and the operating lever 44 is rotated forward, the cam 43 is disengaged from the step portion of the hook plate and the lock is released.
When the rotary tiller 12 is lowered to the ground by holding it by abutting against the rear end face thereof, first, the tail wheel 47 comes into contact with the ground, then the lower connecting pin 17 comes out rearward from the groove 8a, and accordingly, the hook plate 42. As it rotates rearward, its upper portion receives the cam 43 and is ready for connection, and when the hitch frame 5 is further lowered, the upper connection plate 7 is connected to the upper connection pin.
Leave 15

Meanwhile, the rear clutch 33 disengages from the front clutch 21.

Further, when attaching the other working machine to the hitch frame 5, if the cylinder shaft 32 mounted on the input shaft 31 of the removed working machine is pulled out, the centering pin 38 mounted on it and the rear clutch
Since the 33, the oil seal 50, the boot 51, etc. can be integrally removed, by fitting the input shaft 31 of the working machine to be newly installed from the oil seal 50 side, the working machine is hitched. It can be connected to the frame 5 in the same manner as described above.

(G) Effect of the invention Since the invention is configured as described above, when the working machine is connected to the hitch frame 5, if the centering pin 38 enters the front clutch 21 from the misaligned direction, The clutch 21 will tilt in conformity with the centering pin 38 while expanding and contracting the buffer ring 27 together with the transmission shaft on which it is attached,
Front clutch for smooth centering without damaging each part
21 can be engaged with the rear clutch 33.

Further, when the working machine mounted on the hitch frame 5 is replaced, the rear clutch 33 and the centering pin 38 are removed from the working machine that has been used until then against the attraction force of the magnet 40 and the input shaft of the new working machine is removed. By mounting it on 31, various work machines can be easily mounted without preparing a separate rear clutch or the like. Furthermore, the outer periphery of the spring 37 that pushes the rear clutch 21 toward the front clutch side and urges the bellows-shaped boot 51.
Since it is covered with
The expansion / contraction operation and the rear clutch forward / backward movement can be smoothly performed.

[Brief description of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is a sectional view of a connecting portion, FIG. 2 is a side view showing a state in which a working machine is mounted on a hitch frame, and FIG. 3 is a hitch frame. The front view and FIG. 4 are side views of the work machine removed from the hitch frame. 5 ... hitch frame, 7 ... upper connecting plate, 8 ... lower connecting plate, 10 ... bracket, 15 ... upper connecting plate, 20 ... yoke joint, 20b ... rear joint, 21 ... front clutch , 22 …… transmission shaft, 25 …… holder, 27 …… buffer ring, 31 …… input shaft, 33 …… rear clutch, 38 …… centering pin

Claims (1)

[Scope of utility model registration request] 1. A hitch frame 5 is movably connected to a rear part of the machine body via a link, a front part of a yoke joint 20 is connected to a PTO shaft 19 protruding from a rear part of the machine body, and a rear part thereof is an input shaft 31 of a working machine. In the tractor configured to be detachably connected via a clutch, the transmission shaft is connected to the rear joint of the yoke joint 20 and the rear portion is projected, and the protruding portion of the transmission shaft 22 is inserted through an ammunition machine. The front clutch 21, which is held by the hitch frame 5 and has a centering hole at the rear end of the transmission shaft, is fixed so that its meshing portion is separated from the ammunition rearward, and the input shaft of the working machine is also provided. A rear clutch 33 that has a centering pin 38 that engages and disengages with the centering hole of the front clutch 21 is detachably attached to the front clutch 21 by a magnet 40, and the rear clutch Pushes 33 toward the front clutch side The spring 37 is provided that, hitch device in tractor, characterized in that it covers the outer periphery of the spring 37 in the convoluted boot 51.