JPH0329203Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> This invention relates to a drawbar mounting structure for a tractor.

<Prior art> Conventionally, in order to attach a working machine such as a rotary tiller to the rear of a tractor, for example, as shown in FIG. Install with the rear open, and attach the U-shaped mounting part 3 at the rear end.
A mechanism is known in which a rotary frame (not shown) is removably attached to the machine, and the power of the rotary is connected by a universal joint shaft 5 between a PTO shaft 4 protruding from the rear of the aircraft body and an input shaft of the rotary or the like.

Further, a drawbar 7 for attaching a trailer or other towed object is attached to a position near the PTO shaft 4 at the rear lower part of the fuselage 1 via a drawbar bracket 6 in such a manner that it can slide back and forth in the front and rear directions. A connecting fitting 8 is attached to the rear end of the drawbar 7 and is U-shaped in side view and has a connecting pin 9 that is detachably inserted downward. Further, the tubular support 10 into which the draw bar 7 is inserted and the draw bar 7 are set in a fixed position by a set pin 11 inserted in the vertical direction.

<Problems to be solved by the invention> However, in the conventional mechanism as described above, the drawbar is attached to the bottom of the fuselage 1, which lowers the ground clearance of the bottom of the fuselage. In order to slide and store the connecting pin 9 in the vertical position while in use, the connecting pin 9
The lower end of the connecting pin 9 protrudes from the bottom of the fuselage, lowering the ground clearance of the fuselage. In addition, there are disadvantages such as grass, straw, etc. getting wrapped around the lower end of the connecting pin 9 during travel or work, and damage caused by contact with objects on the ground. be.

In addition, in the case of the drawbar mounting structure described above, in order to increase the ground clearance of the bottom of the tractor as much as possible, the drawbar 7, which is mounted at the highest possible position, that is, closer to the PTO axis, must be inserted forward and stored. Since the upper parts of the connecting fittings 8 and the connecting pins 9 contact the bottom of the hitch bracket 2, the storage depth becomes shallow. Therefore, when the rear end of the rotary is lowered to plow deeper, the joint shaft 5 comes into contact with the upper end of the connecting fitting 8 and the connecting pin 9, preventing the downward rotation of the joint shaft 5, and regulating the bending angle θ. This hinders deep plowing work using a rotary and other operations that require downward rotation of the PTO shaft, and problems such as damage to the telescopic sliding surface of the shaft occur with connecting shafts using splines.

<Means for solving the problem> The drawbar mounting structure of the present invention to solve the above problem has a PTO shaft and a hitch bracket arranged at the rear of the aircraft body, and the drawbar mounting structure of the invention is arranged below the bottom of the hitch bracket. A drawbar bracket is provided on the lower end surface of the rear, and a drawbar is supported by the drawbar bracket so as to be freely advanced and retracted in the front and back direction, and the drawbar is provided with a substantially U-shaped connecting fitting that forms an open end toward the rear at the rear end. When the drawbar is in a working posture in which the connecting fitting has a U-shape when viewed from the side, the upper surface of the connecting fitting is located above the top of the tree than on the longitudinal extension of the bottom surface of the hitch bracket, and the drawbar is pulled out rearward, and the connecting fitting is pulled out backwards. In the non-working position where the drawbar is rotated approximately 90 degrees from the above-mentioned working position to face sideways, the top surface of the connecting fitting is located below the treetop rather than on the longitudinal extension of the bottom of the hitch bracket, and the drawbar is stored below the hitch bracket. In addition, the drawbar is fixed to the hitch bracket by a fixing means such as a fixing pin in each working posture.

<Function> According to the drawbar mounting structure of the present invention, when the drawbar is in a working position in which its coupling fittings are U-shaped in side view, the drawbar can be pulled out rearward and fixed to be used to connect a towed object such as a trailer. In the non-working position where the connecting bracket is turned approximately 90 degrees from the working position so that it faces sideways, the top surface of the connecting bracket is located below the tree tree than on the longitudinal extension of the bottom of the hitch bracket, so that it does not interfere with the hitch bracket, etc. The drawbar can be stored and fixed under the hitch bracket.

<Example> Figures 1 to 4 show an example of the present invention. In this example, the mounting structure of the hitch bracket 2, PTO shaft 4, joint shaft 5, etc. at the rear of the fuselage 1 is shown in Figure 5. The drawbar bracket 11 is attached to the bottom surface of the rear end of the fuselage 1 and the bottom surface of the hitch bracket 2 so as to span both.
Directly below the PTO shaft 4, a support 12 made of a cylinder extending in the longitudinal direction is fixed, and a drawbar 13 is fitted into the support 12 from its rear end so as to be able to slide forward and backward in the longitudinal direction.

A connecting fitting 14 having a constant width and having a U-shaped or U-shaped cross section when viewed from the side is fixed to the rear end of the drawbar 13 so as to open rearward.
A shaft hole 16 bored in both side pieces 14a, 14a,
A connecting pin 15 is removably inserted into the connecting pin 16, which pivotally supports the front end of a connecting rod (not shown) of a trailer or other towed object so as to be rotatable left and right. At the upper end of the connecting pin 15, a plate or pin of a certain length is attached as a pin head 17 to prevent the pin from falling off.
They are attached to form a letter shape.

Each side piece 14a, 14a of the connecting fitting 14 is
The side ends of the ribs 14 are bent toward the outer surface while forming a slope that gradually widens toward the rear end.
b, which has a reinforcing effect such as preventing deformation of the side piece 14a due to external force, and also functions as a rotation stopper for the pin itself by coming into contact with the end of the pin head 17 when the connecting pin 15 is inserted. Furthermore, the rotation prevention action of the pin has the effect of preventing wear and deformation of the connecting pin 15 and shaft hole 16 during towing work.

As shown in FIG. 4, when the connecting fitting 14 is connected to a trailer or the like in the "vertical state" (the connecting pin 15 is oriented vertically), the interval (vertical width) between the side pieces 14a, 14a is wide. Therefore, when the drawbar 13 is inserted into the support 12, its upper end or pin head 17 comes into contact with the bottom of the hitch bracket 2 and is regulated. When the connecting fitting 14 is in an unused state), the horizontal width of the connecting fitting 14 is narrower than the vertical width, so that the connecting fitting 14 is inserted deeply until the rear end surface of the connecting fitting 14 comes into contact with the front end of the support 12. (See Fig. 1) On the other hand, in order to set the front and back position of the drawbar 13, a set hole 18 on the fixed side in the lateral direction is drilled through the rear end of the support 12, and the drawbar 13 is connected to the set hole 18. Metal fittings 14
Set holes 19a on the movable side from two directions are spaced apart from each other by a predetermined interval in the front-rear direction and are shifted in phase by approximately 90 degrees with respect to the axis, depending on the vertical state and the horizontal state with a phase shift of approximately 90 degrees. , 19b are bored in a position where one or more stages can be overlapped if aligned with the set hole 18. and set holes 18 and 1
This is a mechanism in which the set pin 20 is inserted in a state in which 9a or 19b are arbitrarily selected and matched as necessary, and each state of the drawbar is set. Among the set holes 19a and 19b on the movable side, one set hole 19b in the sideways state closer to the shaft hole 16 is the set hole 19b of the support on the fixed side when the draw bar 13 is inserted and retracted to the deepest part. It is drilled to match 18.

With the above configuration, when the connecting fitting 14 is used vertically for connecting to a towed object, set it so that the set hole 19a and the set hole 18 are aligned according to the required pull-out length, and when not used for connection. Sometimes, the connecting fitting 14 is placed horizontally and the setting hole 1 is opened.
By aligning and setting the set hole 19b near the shaft hole 16 and the set hole 18 of the 9b,
The drawbar 13 can be placed in a stored state below the hitch bracket 2.

The drawbar 13 can be pulled out rearward in a horizontal state and used for temporary support of the joint shaft 5 when connecting the joint shaft 5 to the work input shaft 21 as shown in FIG. It is no longer necessary to support the heavy joint shaft 5 that hangs downward with one hand during the connection work of the joint shafts 5, thereby reducing labor, safety, and speed of the shaft alignment work. Further, the ribs 14b of the connecting fittings 14 have upwardly expanding left and right inclined surfaces to stabilize their support and prevent damage to the surface of the joint cover 5a.

Next, looking at the downward bending angle of the joint shaft 5 in the above embodiment, as shown by the imaginary line in FIG. , the joint shaft 5 comes into contact with the upper part of the connecting fitting 8 or the connecting pin 9, and its bending angle is limited to a maximum range of about 20° to 25° as indicated by θ ₁ . On the other hand, as shown by solid lines in the figure, the connecting pin 15 and the connecting fitting 14
When the drawbar 13 is inserted and set so that the connecting fitting 14 of the drawbar 13 is close to the rear end of the support 12 with the drawbar 13 facing sideways, the joint shaft 5
is located between the side pieces 14a, 14a of the connecting fitting 14, and its bending angle _θ2 can be close to 30° to 35°, which is the upper limit that allows smooth transmission of power.

On the other hand, looking at the ground clearance at the bottom of the tractor, in the conventional drawbar retracted and fixed state shown by the imaginary line in Fig. 1, the ground clearance determined by the connecting fitting 8 and the connecting pin 9 is higher than the ground clearance H ₂ shown by the solid line. Ground clearance when the drawbar of this invention is retracted and fixed
_H1 is higher and has a preferable structure with no pins or other protrusions protruding from the bottom of the tractor.

<Effects of the invention> According to the drawbar mounting structure of the present invention constructed as described above, the drawbar can be set with the connecting pin facing either vertically or horizontally depending on the purpose of use. By using it as a support rod when connecting the joint shaft, it is possible to not only reduce labor, safety, and speed up the connection work, but also to make the connection work horizontal, especially when in a non-working position without pulling with a drawbar. Since the upper surface of the joint shaft is housed below the hitch bracket, a sufficient bending angle of the joint shaft can be ensured, allowing deep plowing with a rotary, and also preventing damage caused by contact between the joint shaft and the connecting fitting.

In addition, since the drawbar can be retracted as described above, there are no connecting pins protruding from the bottom of the tractor, which increases the ground clearance of the tractor, making it easier to manage work across high ridges and break down ridges. This has practical effects such as making work easier to perform.

[Brief explanation of drawings]

Figure 1 is an enlarged side sectional view showing the main parts of the present invention;
Fig. 2 is a partial perspective view showing how the drawbar is used, Fig. 3 is a rear view thereof, Fig. 4 is a perspective view showing the rear end of the drawbar, and Fig. 5 shows a tractor to which the drawbar of the present invention is attached and a conventional tractor. FIG. 1... Aircraft, 2... Hitachi bracket, 4...
PTO shaft, 5... Joint shaft, 11... Drawbar bracket, 12... Support, 13... Drawbar, 14... Connection fitting, 14a... Side piece,
15... Connection pin, 18... Set hole of support 12, 19a, 19b... Set hole of drawbar 13, 20... Set pin.

Claims (1)

[Scope of utility model registration request] A PTO shaft and a hitch bracket are arranged at the rear of the fuselage, and a drawbar bracket is provided on the lower end surface of the rear of the fuselage below the bottom surface of the hitch bracket. In a case where a drawbar is provided with a substantially U-shaped connecting fitting with an open end toward the rear, when the drawbar is in a working position in which the connecting fitting has a U-shape in side view, the upper surface of the connecting fitting is In the non-working position, the drawbar is pulled out backwards from the front-rear extension line of the bottom of the bracket, and the connecting fitting is rotated approximately 90 degrees from the above-mentioned working position so that it faces sideways.
The upper surface of the connecting fitting is located below the top of the tree than on the longitudinal extension of the bottom surface of the hitch bracket so that the drawbar is stored below the hitch bracket, and the drawbar is attached to the drawbar bracket in each working posture. A drawbar mounting structure for a tractor, characterized in that the drawbar is fixed by a fixing means such as a set pin.