JPS638167Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a check chain attached to a three-point hitch of an agricultural tractor.

This type of check chain connects the lower link of a three-point link hitch to the machine body, and is designed to restrict the rolling of a working machine attached to the lower link and its rear end. However, conventional check chains use turnbuckles as a means to adjust the length, so if the length of the check chain is adjusted to prevent the work equipment from rolling in the raised position, However, the operator may then accidentally operate the turnbuckle and lengthen the check chain, which may cause the work equipment to sway when the aircraft turns, potentially causing the tractor to overturn.

In order to solve the above-mentioned conventional problems, this invention
The check chain has been improved so that the length of the check chain cannot be adjusted unless the connecting pin at the front end of the check chain is removed from the bracket.It is constructed as follows.

That is, in the present invention, the front end of the lower ring is rotatably supported by a hinge pin in the vehicle width direction, a bracket is provided at a position inside the lower link in the vehicle width direction, and the bracket is connected to a support shaft in the vehicle width direction. A stopper is provided to determine the upper limit position of the rotation range of the bracket around the support shaft, and an upper hole and a lower hole are provided in the bracket for selectively and removably attaching the connecting pin. The front end of the check chain is detachably connected to the bracket by the connecting pin, the rear end of the check chain is fixed to the lower link, the check chain is provided with a bolt and nut for length adjustment, and the connecting pin is connected to the connecting pin. The bolt and nut can be rotated relative to each other only when the upper hole is removed, and the upper hole is located closer to the spindle than the lower hole. It is characterized in that the height relative to a certain lower link is set to be shorter than the relative height between the lower hole and the lower link.

Next, embodiments will be described with reference to the drawings.

Figure 1 is a schematic diagram of the left side of an agricultural tractor;
is the front wheel, 2 is the rear wheel, and 3 is the handle. The three-point link hitch 5 includes a lower link 6, a lift arm 7, a lift rod 8, and an upper link 9. In the illustrated state in which the work implement 12 (for example, a rotary) is lowered, both links 6, 9 and the arm 7 are connected.
extends generally in the longitudinal direction of the vehicle body. The front end (left end in FIG. 1) of the lower link 6 is connected to the lower rear end of the transmission case 11 via a hinge pin 10, as will be described later.
It is connected to 2. The front end (lower end when raised) of the lift arm 7 is fixed to the drive shaft 15 of the hydraulic cylinder 13, and the rear end is connected to the rear or intermediate portion of the lower link 6 via the lift rod 8. The front end of the upper link 9 is connected to the upper part of the transmission case 11 via a bracket (not shown) or a pin, and the rear end is connected to the working machine 12 via a mast 16. Reference numeral 17 denotes a drawbar hitch for towing a trailer (not shown) or the like, which extends in the longitudinal direction of the vehicle body, and its front end is fixed to the lower surface of the transmission case 11 as will be described later.

In FIG. 2, which is a schematic plan view, lower links 6, 6 and lift arms 7, 7 are provided one each symmetrically across the vehicle body center line O-O, which will be described in the front and back. Only one hitch 17 is arranged on each of the vehicle body center lines O--O when viewed from above.

In FIG. 3, which is an enlarged partial view of FIG. (only shown in the figure), the front end of the lower link 6 is rotatably fitted into the lower link 6. 19 is a retaining pin. The longitudinally intermediate portion of the pin 10 is supported by a pair of flanges 20 (only one of which is shown in FIG. 3) perpendicular to the pin 10, and the flanges 20 are fixed to the rear surface of the mission case 11 as follows. . As shown in FIG. 4, which is a view of the flanges 20, the flanges 20, 20 are provided with holes 21, 21, into which the pins 10 are fitted, in the vertically intermediate portions, and the upper portions of the flanges 20, 20 are provided with holes 21, 21 at right angles thereto. It is fixed to each plate-shaped portion 22. The portion 22 protrudes further outward in the vehicle width direction (to the left and right in FIG. 4) than the flanges 20, 20, and is provided with bolt insertion holes 23, 23 at both left and right ends thereof, as shown in FIG. As shown in FIG. 5, the plate-shaped portion 22 is fixed to the rear surface of the mission case 11 by bolts 25 inserted through each hole 23. As shown in FIG. A lower end portion of a bracket 29 for the PTO shaft 27 portion is located behind the plate portion 22 with the collar 26 in between, and the bracket 29 is also fixed to the case 11 by the bolts 25 mentioned above.

In FIG. 3, the hinge pin 10 (pivot shaft of the lower link 6) has a cylindrical boss 3 of a plate-shaped bracket 30.
1 is rotatably fitted. Plate bracket 3
0 (left side in FIG. 3) extends perpendicularly to the pin 10 adjacent to the outer surface of the flange 20, and the rear portion 32 is bent away from the centerline O--O. The bent rear portion 32 of the bracket 30
The front end of a check chain 39 is connected to the front end of the check chain 39 via a connecting pin 37 inserted through a pin attachment hole 35 or 36. As shown in FIG. 6, which is a partial cross-sectional view of FIG. 35, the lower hole 36 is located farther (rearward) by a distance l from the center of rotation of the bracket 30 (pin 10).
It is in. A stopper 4 is provided on the upper part of the flange 20.
0 is provided so as to protrude upward from the bracket 30. When the bracket 30' comes into contact with the stopper 40 and reaches the upper limit position as shown by the two-dot chain line 30', the lower link 6' is in the raised position when viewed from the side of the vehicle body as shown in Fig. 6 (the center line is shown in Fig. 6). The dimensions of each part are determined so that the upper hole 35' is at the same height and the lower hole 36' is at a lower position by an angular difference D. In addition, 30" is check chain 39
The bracket is shown with the bracket removed.

The check chain 39 in FIG. 3 has a pair of parallel members 41, 41 at its front end, and both ends of the connecting pin 37 fit into holes at the front ends of the members 41, 41.
Further, a pine needle pin 42 or other pin for preventing removal is removably attached to the tip of the pin 37. The rear ends of the members 41, 41 are connected to each other by a pin 43, and a chain portion 45 is engaged with the intermediate portion of the pin 43. As shown in FIG. 7, which is a cross-sectional view of FIG.
A hexagonal nut 46 is integrally provided between both ends of the portion 45. The nut 46 is screwed into an eye bolt 47 extending along the center line PP and is fixed by a lock nut 48. A retaining pin 49 protruding from the front end of the bolt 47 is perpendicular to the center line P-P, and both straight parts of a U-shaped chain part 50 parallel to the center line P-P are provided at the rear end of the bolt 47. The front part is welded. chain part 50
For example, three ring-shaped chain parts 51, 51, 51
It is connected to the chain portion 52 at the rear end via. The chain portion 52 is integrally provided with a bolt 53, and the bolt 53
As shown in FIG. 3, the lower link 6 is inserted into a hole 54 in the longitudinally intermediate portion from the vehicle body center line OO side and is fixed with a nut 55. Note that the pin 43 and the pair of members 41, 41 may be replaced with an integral U-shaped chain portion.

As shown in Fig. 3, the hinge pin 10 is connected to the lower link 6.
The portion between the cylindrical boss 31 of the bracket 30 and the cylindrical boss 61 of the plate-like support 60 is rotatably supported. As shown in FIG. 5, the upper and lower parts of the support 60 are fixed to the side surface of the mission case 11 and a bracket (not shown) on the side of the case 11 by bolts 62 and 63.

The front portion of the drawbar hitch 17 is supported by the mission case 11 via a support 65.
As shown in FIG. 8, which is a partial cross-sectional view, the support 65 includes a long upper plate 66 in the front and back, and the upper plate 66 is fixed to the lower surface of the mission case 11 with two bolts 67, 67. The upper ends of plate members 69 and 70 are welded to the rear end (right end in FIG. 8) and front part of the upper plate 66. As shown in Figure 4, member 6 seen from the rear.
9 is approximately U-shaped or U-shaped with an open top, and member 70 in FIG. 8 also has approximately the same shape. Both members 6
Both ends of a longitudinally long lower plate 73 are welded to the lower surfaces of the bottom walls 71, 72 of the plates 9, 70. The drawbar hitch 17 passes inside both members 69 and 70 and is connected to the support 65 via a vertical pin 75. That is, the middle part of the pin 75 fits into the vertical hole 76 of the drawbar hitch 17, the lower end part fits into the hole in the bottom wall 71 of the member 69, and the upper end part fits into the hole in the upper plate 66. There is. Furthermore, the upper part of the pin 75 is fitted into a cylindrical member 77 and fixed by a pin pin 79, and the cylindrical member 77 is welded to the lower surface of the upper plate 66. As shown in FIG. 4, both vertical side walls 80, 80 of the member 69 are in contact with the lower inner surfaces of the flanges 20, 20 for the hinge pin 10,
Each side wall 80 is fixed to an adjacent flange 20 by bolts 81. Each bolt 81 is inserted into a hole in the flange 20 from the outside in the vehicle width direction, and each side wall 80 is provided with a screw hole 82 into which the bolt 81 is screwed.

Next, the length adjustment of the check chain 39 shown in FIG. 3 and its function will be explained. When adjusting the length of the check chain 39 in FIG. 3, first pull out the pin 42, remove the connecting pin 37 from the bracket 30, turn each part from the pin 37 to the nut 46, and screw the nut 46 onto the bolt 47. Adjust the position, then fit the connecting pin 37 into one of the two holes 35, 36 of the bracket 30 and tighten the pin 4.
2 to prevent it from coming off.

In that case, the length of the check chain 39 and the mounting hole 35 or 36 of the pin 37 are
The settings are as follows depending on the type of In other words, if the working machine 12 is of a type such as a rotary, in which it is desired to reliably prevent rolling during work (in the lowered position), the connecting pin 37 is attached to the upper hole 35 in FIG. The length of the check chain 39 (Fig. 3) is adjusted so that the check chain 39 (Fig. 3) remains in tension when the lower link 6 in the lowered position and the upper mounting hole 35 are located at the same height when viewed from the side of the vehicle body as shown in Fig. 6. In other words, the length of the check chain 39 is adjusted to be as short as possible so that the mounting hole 35 is kept at the same height as the lower link 6. In this way, the lower link 6 is pulled toward the center of the vehicle body by the check chain 39 in the lowered position, so that the work implement 12 during work can be reliably prevented from rolling. Further, the working machine 12 can be raised to a predetermined position while preventing sideways movement. In other words, when the check chain 39 is tensed, when the lower link 6 is raised, the lower link 6' can only be raised to the same height as the upper limit position of the mounting hole 35 (35': Fig. 6). Bracket 3
0' is in contact with the stopper 40, the upper mounting hole 35' is at the same height as the lower link in the raised position, so the lower link 6' can be raised to a predetermined raised position.
In addition, since the check chain 39 remains in tension even in the raised position, horizontal swinging of the lower ring 6' is reliably prevented. Therefore, when the work machine 12 is raised and the machine body is turned, the work machine 12 does not sway horizontally. Note that when the mounting hole 35' is aligned with the lower link 6' in the raised position, the bracket 3
It is also possible to leave a gap between 0 and the stopper 40. However, in that case, it is necessary to make the gap relatively small so that the following effect regarding the lower mounting hole 36 can be obtained.

When installing a type of work equipment 12, such as a plow, in which it is desired to allow some lateral movement during work, the connecting pin 37 shown in Fig. 3 is replaced from the upper mounting hole 35 shown in Fig. 6 to the lower mounting hole 36. . Then, the mounting position (hole 36) of the connecting pin 37 will move backward by a distance l from the previous mounting position (hole 35), so when the lower link 6 is lowered, the check chain will be moved by an amount corresponding to the distance l. 3
9 loosens. Therefore, in the lowered position, the lower link 6 can swing to a certain extent in the vehicle width direction without being pulled by the check chain 39, allowing the work implement 12 to sway horizontally during work.
Even in this case, horizontal shaking of the working machine 12 in the raised position is reliably prevented. That is, since the upper limit position 30' of the bracket 30 is set by the stopper 40 as described above, the lower mounting hole 36' is located below the lower link 6' at the upper limit position by an angular difference D, and the angular difference is Corresponding to D, the minimum required length of the check chain 39 (the distance from the mounting hole 36 to the bolt insertion hole 54 in FIG. 3) increases. Therefore, the slack in the check chain 39 is absorbed and the check chain 39 becomes taut, and the lower link 6' and the work implement 12 are reliably prevented from rolling in the raised position.

Next, when reattaching a rotary or the like as the working machine 12, the connecting pin 37 is replaced from the lower attachment hole 36 to the upper attachment hole 35. In this case, the required length of the chain 39 increases by the distance l, so
The chain 39 can be kept under tension.

If you wish to finely adjust the degree of horizontal oscillation of the working machine 12, when replacing the connecting pin 37 between the holes 35 and 36, turn the nut 46 shown in FIG. The length can be adjusted.

As explained above, according to the present invention, the length of the check chain 39 shown in FIG. 3 cannot be adjusted unless the connecting pin 37 is removed from the bracket 30.
There is almost no fear of increasing the length of 9. Therefore, it is possible to prevent the working machine 12 from rolling in the raised position, and to prevent the body from rolling over when turning or the like. Further, when the length of the check chain 39 is set so that the working machine 12 can swing by a predetermined amount in the working position, as in the case of a plow, it is possible to prevent the predetermined swing amount from going out of order.

Furthermore, in the present invention, two types of holes 35 and 36 are provided in the bracket 30 as holes for attaching the connecting pin 37 of the check chain 39, and these holes 35 and 36 are configured as follows.

That is, the upper hole 35 is arranged closer to the spindle 10 than the lower hole 36, and at the upper limit position of the bracket 30 determined by the stopper 40, the relative relationship between the upper hole 35' and the lower link 6' in the raised position is adjusted. The relative height of the lower hole 36' and the lower link 6' is set to be shorter than the relative height of the lower hole 36' and the lower link 6'.

Therefore, even if the length of the check chain 39 is adjusted so as to prevent the lower link 6 from rolling in the raised position, if the pin 37 is installed in the upper hole 35, the check chain 39 will not move even in the lowered position. The horizontal swing of the lower link 6 can be restricted, and when the pin 37 is installed in the lower hole 36, the horizontal swing of the lower link 6 can be allowed in the lowered position.

In this way, with the present invention, by simply selecting the connecting pin mounting hole, the lower link can easily set the lower link's lowering state (sway permissible and swing prevention), and in the raised state, it always prevents rolling. be able to.

Note that the bracket 30 can also be attached to a portion other than the hinge pin 10.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of the left side of an agricultural tractor, Figure 2 is a schematic plan view of the agricultural tractor, Figure 3 is an enlarged partial view of Figure 2, and Figures 4 and 5 are viewed from the - and - arrows in Figure 3. 6 and 7 are cross-sectional partial views of FIG. 3, and FIG. 8 is a partially cutaway partial view of FIG. 5. 6...Lower link, 30...Bracket, 3
5, 36... Connecting pin mounting hole, 37... Connecting pin, 39... Check chain, 40... Stopper, 46... Nut, 47... Bolt.

Claims (1)

[Scope of utility model registration request] The front end of the lower ring is rotatably supported by a hinge pin in the vehicle width direction, a bracket is provided at a position inside the lower link in the vehicle width direction, and the bracket is supported by the vehicle body via a support shaft in the vehicle width direction. death,
A stopper is provided to determine the upper limit position of the rotation range of the bracket around the support shaft, and an upper hole and a lower hole are provided in the bracket for selectively and removably attaching a connecting pin, and the connecting pin is used for checking. The front end of the chain is removably connected to the bracket, the rear end of the check chain is fixed to the lower link, and the check chain is provided with bolts and nuts for length adjustment, and the bolts are removed only when the connecting pin is removed. and the nut can be rotated relatively, and the upper hole is located closer to the spindle than the lower hole, and at the upper limit position, the upper hole and the lower link in the raised position are rotated relative to each other. A check chain for an agricultural tractor, characterized in that a height thereof is set to be shorter than a relative height between a lower hole and a lower link.