JPH0144003Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a work implement coupling device for an agricultural tractor.

(Prior Art) A quick coupler for a three-point hitch that can connect the work machine body while riding is known. However, in that case, it was necessary to connect the universal joint between the PTO shaft on the machine side and the input shaft on the work equipment side by hand, which caused a problem in that it was time-consuming to attach and detach the work equipment.

There is also a coupling device, such as U.S. Patent No. 4,090,725, that allows you to connect the work machine and drive system while riding on the tractor, but the spring that biases the engaging part is placed on the work machine input shaft side. A spring must be provided for each working machine, which increases costs and requires time and effort to process the working machine input shaft.

In addition, in the above-mentioned conventional technology, the stroke amount of the spring is limited to an extremely short length, so if the protrusions of the teeth touch each other when connecting the work machine, the "relief action" by the spring will be incomplete, and the work machine may be pushed down.

(Purpose of the invention) The purpose of the invention is to make it easier to connect work equipment, to simplify the coupler frame attached to the rear end of the hitch, and to perfect the centering action. The goal is to make the power connection part more compact, reduce the number of parts, and reduce costs.

(Technical means for achieving the object) In order to achieve the above object, the present invention provides a quick coupler frame at the rear end of a three-point link hitch consisting of one top ring 4 and a pair of left and right lower links 3. The quick coupler frame 5 has an inverted U-shaped horseshoe shape when viewed from the rear, and has a bearing in the center of a stay that projects inward from both legs of the quick coupler frame. The rear end of the drive shaft, which is connected to the rear end PTO shaft of the tractor, is supported by the quick coupler frame via a bearing, and the rear end of the drive shaft and the front end of the work equipment input shaft are mutually engaged and disconnected. A flexible engaging portion is provided, and the engaging portion is formed so as to protrude from the supporting portion toward the work machine, and the engaging portion is provided on the connecting side of the supporting portion of the quick coupler frame on the drive shaft side. In addition to incorporating a spring that biases the
The expansion and contraction stroke of the spring is made larger than the dimension of the protrusion of the engaging portion, the quick coupler frame is provided with a connecting mechanism that can freely engage with the connecting pin of the working machine, and the bearing is located approximately directly below the upper connecting mechanism. It is located.

(Function) By bringing the quick coupler frame connected to the three-point link hitch of the tractor closer to the work equipment side, the connection pin of the work equipment engages with the coupling mechanism, and the work equipment input shaft is connected to the rear end of the drive shaft. Connecting.

The quick coupler frame is formed into an inverted U-shaped horseshoe shape when viewed from the rear, and has a bearing in the center of a stay that protrudes inward from both legs of the coupler frame. Since the bearing is positioned substantially directly below the upper coupling mechanism, the shape of the quick coupler frame is simplified, and manufacturing and processing become easier.

In addition, the bearing is located in the center of the stay that protrudes inward from both legs of the quick coupler frame, and is located almost directly below the upper connection mechanism, so it is difficult to align the connection mechanism when installing the work equipment. If so, the axes will automatically match, making alignment easy and preventing unnecessary loads from acting on the bearing.

The drive shaft side is equipped with a spring that can exert a relief action for the engagement part, so the area around the support part at the rear end of the drive shaft becomes compact, and each work machine has its own spring that can exert a relief action. This eliminates the need for this, which saves the number of parts and reduces costs.

(Example) Fig. 1 is a schematic left side view of a three-point link hitch 1 at the rear of an agricultural tractor and a working machine (rotary) 2 placed at a distance behind it (on the right side of the figure).
A gate-shaped quick coupler frame is attached to the rear end of the pair of left-facing lower links 3 and one top link 4 above them (the end in the reverse F direction, that is, the right end in the figure) that constitute the three-point link hitch 1. 5 is pivotally connected via pins 6 and 7 in the vehicle width direction. The left lower link 3 shown in Fig. 1 has its front end (left end in the figure) supported by a bracket 10 on the rear axle case 9 side via a pin 8, and the middle part near the rear end is supported by a lift. It is connected to the left lift arm 12 via a link 11. Reference numeral 13 denotes a lift shaft, which is supported by a hydraulic cylinder case 14 mounted on the rear axle case 9. Left and right lift arms 12 are attached to the portions protruding outward from the case 14 to the left and right.
The front end of is stuck. The right lower link 3 is similarly connected to the right lift arm 122 via the right lift link 11. The top link 4 extends in the front-rear direction between the two lift links 11, and its front end connects to the bracket 1 via a pin 20.
Connect to 5. A PTO shaft 16 protruding rearward from the rear axle case 9 is connected to the front end of a drive shaft 18 via a universal joint 17, and the rear end of the drive shaft 18 is connected to a universal joint 19 supported by the quick coupler frame 5. It is connected to the rear yoke 49. Both universal joints 17 and 19 are made of a pair of yokes and a cross-shaped spider connecting both yokes, and one yoke of the universal joint 17 is connected to the PTO shaft 16.
The other yoke is spline-fitted to the drive shaft 18, and the other yoke is spline-fitted to the drive shaft 18. One yoke of the universal joint 19 is spline-fitted to the drive shaft 18,
The other rear yoke 49 is rotatably supported by the quick coupler frame 5, as will be described later.

The quick coupler frame 5 has a rectangular cylinder-shaped bracket 2 that opens rearward at the upper end and both left and right lower ends.
1, and a guide 22 protruding rearward from the lower end of the bracket 21 has a rear downward slope 23 on the upper side. Both ends of a pin 24 are fixed to the left and right side walls of the bracket 21, and a hook claw 25 is rotatably supported on the pin 24 within the bracket 21. A coil spring 26 is compressed between the upper wall of the bracket 21 and the hook claw 25 is connected to the pin 24.
It is normally pressed against the guide slope 23 by receiving a moment in the direction of arrow A about . Hook claw 2
5 has a front downward slope 27 and a downward opening hook surface 28 on the lower side.
A connecting pin 29 of the working machine 2, which will be described later, can be held between the hook surface 28 and the guide 22, and at this time, the pin 29 is located directly behind the pin 24 and is attached to the vertical rear edge of the hook surface 28. Coupled with the fact that the hook claw 25 is receiving a moment in the direction of arrow A by the coil spring 26, there is no fear that the pin 29 will come off from the hook claw 25 when the work machine is towed. A solenoid 30 is installed on the bracket 21 at a position below the hook pawl 25 and facing the coil spring 26.
is installed, and the iron core 31 inside the solenoid 30
The upper end faces the lower surface of the hook pawl 25, and when the solenoid 30 is energized, the iron core 31 protrudes upward and resists the elasticity of the coil spring 26 to move the hook pawl 25 in a reverse A position.
direction to release the pin 29 from the hook claw 25.

The three connecting pins 29 on the work machine 2 side are provided in a horizontal position at the upper end and the left and right lower ends of the quick coupler frame 33, which has a shape corresponding to the quick coupler frame 5 on the machine side. The pins 29 are opposed to rear-opening V-shaped slopes 23 and 27, respectively. An input shaft 35 projects forward from a gearbox 34 of the working machine 2, and a front beam 36 projects in the vehicle width direction from the left and right side walls of the gearbox 34, and a gear case 37 is attached to one end of the front beam 36. 38 is a rotor pawl, 39 is a tail wheel frame, 4
0 is an adjustment pipe, 41 is a tail wheel, and 42 is a rotary cover. A bracket 43 is attached near the end of the front beam 36 near the gear case 37 so as not to interfere with the quick coupler frame 5, and a stand 44 is attached to the front end of the bracket 44 so as to be vertically adjustable. This stand 44
This member has the role of assisting in supporting the working machine 2 when the quick coupler frame 5 of the tractor is connected to the working machine 2 on standby, and is a member that is retracted upward during plowing work.

In FIG. 2, which is a rear view of the quick coupler frame 5 in FIG. 1, the shape of the coupler frame 5 is gate-shaped as described above, but more specifically, it is formed into an inverted U-shaped horseshoe shape. ing.
The stay 46 that connects the lower end of the frame 5 has a half metal 47 divided into upper and lower halves in the center and a metal presser 4.
8, and this half metal 47 is the rear yoke 4.
It rotatably supports the boss portion of No. 9.

In Fig. 3 showing the - section of Fig. 2, 5
0 is a spider, and 51 is a front yoke. The yoke 49 has a stepped spline hole 52 facing rearward (in the reverse F direction), and a coil spring 55 is inserted between the dog claw 53 fitted in the spline hole 52 and the stepped portion 54.
has been reduced. 56 is a snap ring.
The yoke 49 has a conical surface 58 near the rear end of the boss portion 45 that becomes narrower toward the rear, while the flange 59 at the front end of the input shaft 35 on the working machine side
3 and a conical surface 61 that engages with the conical surface 58. The conical surfaces 58 and 61 serve to guide the quick coupler frame 5 of the tractor so that the center lines of the dog claws 53 and 60 coincide when approaching the standby working machine, and also to guide both dog claws 53 and 60 so that their center lines coincide. , 60 are brought into contact with each other and act as a cone clutch.

To connect the standby working machine 2 to the three-point link hitch 1 of the tractor as shown in FIG. 1, adjust the height of the quick coupler frame 5 on the tractor side using the lift arm 12, and then 27 is adjusted to the height of the working machine side connecting pin 29, the quick coupler frame 5 of the tractor is gently approached, and the slope 27 is pressed against the pin 29. At this time, the stand 44 prevents the work equipment 2 from retreating, so the hook pawl 25 rotates in the opposite direction A against the elasticity of the coil spring 26, and when the slope 27 passes the pin 29, the pin 29 Fits within surface 28. Also, the dog claw 53 (the third
(Fig.) engages with the dog pawl 60 of the working machine input shaft 35, thereby also connecting the power system. After that, raise the stand 44 to a predetermined height and attach the bracket 43.
If you fix it in place, you can continue tilling work.

To remove the work implement 2, the tractor is stopped and the solenoid 30 is energized. Then solenoid 3
0 excitation causes the iron core 31 to protrude upward, and the hook pawl 25 rotates in the reverse A direction against the elasticity of the coil spring 26, releasing the connecting pin 29. In this state, the quick coupler frame 5 of the tractor When the hook is moved slightly away from the work machine side, the hook claw 25 moves forward from the connecting pin 29, and at the same time, the tractor-side dog claw 53 moves forward from the work machine-side dog claw 60, leaving the work machine 2 behind and moving the tractor forward. be able to. Thereafter, the stand 44 is erected to the position shown in FIG. 1 in preparation for the next connection operation.

Instead of using the solenoid 30 to release the connecting pin 29 from the hook pawl 25, a hydraulic cylinder 6 may be used as shown in FIG. The hydraulic cylinder 63 is attached to the bracket 21, and the rod 65 of the piston 64 fitted inside is connected to the hook pawl 2 through a pin 67 at the yoke 66.
Connected to 5. In this case, the coil spring 26 is mounted around the rod 65. stand 44
A brake may be attached to the tail wheel 41 instead. The stand 44 may not be necessary in some cases.

(Effects of the invention) As explained above, according to the invention: (1) The quick coupler frame is pivotally attached to the rear end of the three-point link hitch so as to hold it in a substantially vertical position, and the The rear end portion of the connected drive shaft 18 is supported by the quick coupler frame 5, and engagement portions that can be freely engaged and disengaged from each other are formed at the rear end portion of the drive shaft 18 and the front end of the work equipment input shaft, and the quick coupler frame 5 supports the rear end portion of the connected drive shaft 18. Since the coupler frame 5 is provided with a connection mechanism that can freely engage with the connection pin 29 of the work machine, it is possible to connect not only the main body of the work machine but also the drive system by simply bringing the quick coupler frame close to each other. The work of connecting machines becomes easier.

(2) The quick coupler frame 5, which is pivotally attached to the rear end of the three-point link hitch 1, is formed into an inverted U-shaped horseshoe shape when viewed from the rear.
Stays 46, 46 protrude inwardly from both legs of the
has a bearing 47 in the center thereof, supports the rear end of the drive shaft via the bearing 47, and supports the rear end of the drive shaft through the bearing 47.
Since it is located substantially directly below the upper connecting mechanism 25, the shape of the quick coupler frame is simplified and manufacturing and processing become easier.

(3) Bearing 47 that supports the rear end of drive shaft 18
is the center part of the stays 46, 46 protruding inward from both legs of the quick coupler frame 5,
Moreover, it is located almost directly below the upper connection mechanism 25, so when the work machine is attached, the connection mechanism 25
If 5, 25, and 25 are matched, the axes will automatically match, making alignment easy.
No unnecessary load is applied to the bearing 47, and the life of the bearing 47 is also improved.

(4) Since the extension and contraction stroke of the spring 55 for biasing the engaging portion is configured to be larger than the protrusion size of the engaging portion (dog pawl) 53, 60, the engaging portion 53, 60
When the two protrusions collide, the engaging part (dog pawl) 53 on the drive shaft side, which is biased by the spring 55, retreats against the spring 55, allowing the engaging parts to approach. That is to say.

In other words, since the spring 55 has a "relief action", even if the protrusions of the engaging parts 53 and 60 come into contact, the above-mentioned escape action will cause the coupling mechanism and the connection pin of the working machine to It becomes possible to connect
To solve the problem of pushing down the work machine during the work machine connection work, and to eliminate the need for a special connection mechanism.

(5) A spring 55 that can exert a relief action on the engagement part,
Since it is installed inside the support part of the quick coupler frame 5 on the drive shaft 18 side, the area around the support part becomes compact and a special cover for protecting the spring is not required.

If the protrusions of the engaging parts touch each other, the spring 55 will not exert the escape action of one of the engaging parts 53. (6) The engaging part will move from the supporting part of the coupler frame 5 to the working machine side. The protrusion makes alignment and engagement easier.

(7) Since the spring 55 for biasing the engaging part is internally installed in the support part of the quick coupler frame on the drive shaft side, when replacing and installing various types of work machines, the above-mentioned It is not necessary to provide a spring having a relief action as in the above, and only one spring 55 having a relief action is required.
Economical. Further, there is no need to perform processing for arranging springs for each input shaft of various working machines.

(8) The spring 55 of the present application has the above-mentioned "relief action", but in this case, the engaging portion 53 on the drive shaft side retreats toward the drive shaft side, that is, the quick coupler frame 5 side, and the quick coupler frame 5, the rotation radius of the engaging part with respect to the center of rotation of the universal joint, etc. in the bearing part becomes smaller, the misalignment becomes smaller, and the moment of the engaging part becomes smaller. Support by the frame 5 is stable.

[Brief explanation of the drawing]

Figure 1 is a schematic view of the left side showing the three-point link hitch at the rear of the tractor and the work equipment waiting behind it;
3 is an enlarged cross-sectional view of FIG. 2, and FIG. 4 is a drawing corresponding to a part of FIG. 1 to show another embodiment. ...Three-point link hitch, 3...Lower link, 4
... Top link, 5 ... Quick coupler frame, 16 ... PTO axis, 18 ... Drive shaft,
25... Hook claw (an example of a connection mechanism), 29...
Connecting pin, 46...stay, 47...bearing, 5
3, 60... dog claw (an example of an engaging part), 55...
...Spring.

Claims (1)

[Scope of utility model registration request] A quick coupler frame 5 is pivotally attached to the rear end of a three-point link hitch 1 consisting of one top link 4 and a pair of left and right lower links 3 so as to hold it in a substantially vertical position. It has a horseshoe shape with an inverted U-shape in view, and has a bearing 47 at the center of stays 46, 46 protruding inward from both legs of the quick coupler frame 5, and is connected to the rear end PTO shaft 16 of the tractor. Drive axis 1
8 is supported by the quick coupler frame 5 via a bearing 47, and an engaging portion is provided at the rear end of the drive shaft 18 and the front end of the work equipment input shaft so that they can be freely engaged with and disengaged from each other. are formed so as to protrude from the support portion toward the work machine, and the support portion of the quick coupler frame 5 on the drive shaft side is provided with a spring 55 that biases the engagement portion toward the connection side; The expansion and contraction stroke of the spring is made larger than the size of the protrusion of the engaging portion, the quick coupler frame 5 is provided with a connecting mechanism that can freely engage with the connecting pin 29 of the working machine, and the bearing 47 is connected to the upper connecting mechanism 25. A working machine coupling device for an agricultural tractor, characterized in that the device is located substantially directly below the tractor.