JPH0753448Y2 - Hitch device in tractor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a hitch device in a tractor in which a hitch frame is mounted on a rear portion of a tractor via an elevating link and a work machine is attached to and detached from the hitch frame.

(B) Prior art Conventionally, in a hitch device for a tractor, a rear connecting tool that protrudes forward from a component member of the working machine is attached to both front lower parts of the working machine, and a rear connecting tool at an upper center projects forward from the working machine. When attached to the support arm and connecting the working machine to the hitch frame, the hitch frame is lifted by the lift arm via the lift rod and the lower link, and the front connecting tool at the upper part of the hitch frame is located at the rear center of the front upper part of the working machine. To hang the work implement by engaging the connecting tool, and then connect the front connecting tools on both lower sides of the hitch frame to the rear connecting tools on both lower sides of the working machine to facilitate connecting the working machine next time when detaching. It is already known that the stand is set in a supporting posture or the tail wheel is lowered, and then the hitch frame is lowered by the lift arm to separate the upper and lower connecting members from each other.

(C) Problems to be Solved by the Invention The hitch device in the known tractor has an upper rear connecting member when a lower rear connecting member of the working device is projected forward from a front end of a working member constituting member, for example, a rotary cover. Also has to be projected forward so as to correspond to the lower one, and the distance between the working machine and the tractor eventually becomes large, so there was a problem that the circling property deteriorates and the headland becomes wide. .

In order to solve such problems, if the connecting point is set to the rear upper part from the front end of the working machine component, the weight of the hitch frame itself is considerably large when the hitch frame is lowered to separate from the working machine. Since the lower link and the yoke joint are also added with the weight, and the lift arm is generally lifted and lowered by a single-acting hydraulic cylinder, the rear couplings on both lower sides of the hitch frame are connected to the working machine. A new problem arises in that it collides with the protrusion and damages it.

(D) Means for Solving the Problems In the present invention, the hitch frame 2 is attached to the rear of the tractor via the elevating links 3 and 4 so that the hitch frame 2 can be moved up and down, and the front portion is connected to the upper center and both lower sides of the hitch frame 2. Attach the tools A and B, and attach the rear connectors corresponding to the front connectors A and B to the front part of the working machine at the upper center and both sides of the lower part so that the working machine can be attached to and detached from the hitch frame 2. In the tractor configured as described above, a member that supports a rear connecting tool at the center of the upper part of the working machine is received by a member that supports the rear connecting tool at the center of the upper portion of the hitch frame 2 and wraps with the descending locus of the tip end of the connecting / disconnecting work. 23 is attached to the front connecting tool B, and when the front connecting tool B comes into contact with the receiving member 23 when the front connecting tool B descends, it receives the front connecting tool B and guides the hitch frame 2 and the working machine in the separating direction. It is characterized in that the rear guide surface 19 is formed.

(E) Action When connecting the work machine to the hitch frame, raise the hitch frame together with the lower link by raising and tilting the lift arm while retracting the tractor, and bring the front connector on the upper part into contact with the receiving metal. When the hitch frame is further raised from that state, the front connecting tool engages with the rear connecting tool at the upper front part of the working machine, so that the working machine is lifted, whereby the working machine is centered on the upper connecting section. The lower connecting portion is connected to the left and right as it rotates.

Also, when removing the working machine from the hitch frame, if the working machine is of the working depth automatic control type, the stand is erected in the working posture, and if the working machine is of the type that regulates the working depth, the tail wheel is lowered. , Unlock the connecting parts on both sides of the lower part, and lower the hitch frame.First, the rear part of the working machine is grounded, then the front part is grounded, and then the front connector on the upper part of the hitch frame is separated from the rear connector. Separates and descends.

Then, when the timing of stopping the lift arm that is tilting downward is delayed, the connector on the upper part of the hitch frame is received by the receiver, and the weight of the hitch frame is large and the weight of the lower link and the yoke joint is added to it. Therefore, when the ground contact surface is hard, the work implement is pushed backward, and when it is soft, the hitch frame is disengaged from the work implement when the tractor is advanced.

At this time, if the money is not received, the connector at the bottom of the hitch frame collides with the rotary cover or the like at the front of the working machine and damages it.

Further, by allowing the hitch frame to penetrate into the lower member of the working machine, the distance between the working machine and the tractor can be narrowed, and the turning radius can be reduced.

(F) Embodiments An embodiment of the present invention will be described with reference to the drawings. 1 is a mission case of a tractor, and a hitch frame 2 is a transmission case of the mission case 1 via a top link 3 and left and right lower links 4, 4. The lift arm 5 which is connected to the rear part and tilts up and down by a hydraulic device is connected to the lower links 4 and 4 through the lift rod 6, and the rear part is connected to the hitch frame 2 though not shown on the PTO shaft 7. The front part of the supported yoke joint is connected.

Reference numeral 8 denotes a rotary cultivator shown as an example of a working machine. Like the conventional one, the rotary cultivator is installed between the transmission case lowered from one end of the upper main frame, the support frame on the other side, and their lower parts, and a large number of tillers are mounted. Cultivating shaft with pawls 10 mounted thereon, rotary cover 11 covering the rotation locus of the plowing pawls 10 and tail wheels 13 and 13 pivotally supported by columns 14 at the rear of the tool bar 12.
It consists of and.

The hitch frame 2 is connected to a connecting plate 15 having a groove whose rear part is open and a locking plate 16 having a guide groove whose upper part is rotatably open and a lower part is connected to the lower part on both sides. A front connecting member A consisting of a horizontal lock pin (not shown) is attached, and a receiving groove 17 having an opening at the top is formed in the upper center of the hitch frame 2 and a downward inclination toward the receiving groove 17. The front connecting member B constituted by the guide surfaces 18 and 18 and the rear guide surface 19 curved upward is attached. Reference numeral 17a is a U-shaped metal fitting welded along the inside of the receiving groove 17.

Further, a top mast 20 pivotally supported on the main frame so as to be tiltable in the front-and-back direction has a pair of left and right plates branched into a V-shape, and a branch arm 20b at the rear of the top mast 20 is supported by an adjusting screw rod 21 on a tool bar 12.
And a pair of left and right mast stays 22, 22 rising from the main frame in the middle of the front branch arm 20a.
As shown in FIGS. 3A and 3B, the receiving member 23 made of a pipe is fitted inside the overlapping portion, and the bolts 25 are inserted into the holes and the receiving member 23 and fastened to the nut 26. Yes,
On the tip side of it, the upper connecting pin 27 which becomes the rear connecting tool.
As shown in FIGS. 1 and 2, the receiving metal 23 has a vertical space for engaging and disengaging the upper front connecting tool B with respect to the upper connecting pin 27, and It is provided at a position where it overlaps with the rotation trajectory of the rear part.

Further, at the lower ends of the brackets 28, 28 hanging from both sides of the main frame in a diagonally forward direction, lower connecting pins 30, 30 constituting a rear connecting tool are provided so as to project. As shown in FIG. 4, reference numerals 30, 30 face the upper surface of the rotary cover 11 near the rear end from the front end.

In the above-mentioned tractor, when the working machine is attached to the hitch frame 2, the hitch frame 2 is lowered by the lift arm 5.
As shown in FIG. 4, the rear guide surface 19 receives gold 23 and 4,4.
When the tractor is retracted in this state until the rear guide surface 19 of the front connecting tool B contacts the receiving metal 23 and then raised, the receiving groove 17 of the front connecting tool B is When the hitch frame 2 is further raised in this state by fitting with the upper connecting pin 27, the rotary tiller 8 is in the ascending posture shown in FIG. Since the lock pin locks the connecting plate 15 and the locking plate 16 with each other, the work is performed by lowering the lock plate to the ground.

Further, when the rotary cultivator 8 is detached, if it is a type in which the tailing depth is adjusted by the tail wheel, the tail wheel 13 is lowered to such an extent that the landing posture becomes the forward leaning posture shown in FIG. In the system that automatically detects and controls the working depth,
When a proper stand is erected, the lock pins of the front couplings A, A are pulled out, the lift arm 5 is tilted downwardly, and the rotary tiller 8 is lowered together with the hitch frame 2, the rear part of the rotary tiller 8 is first set. Is grounded, then the front is grounded.

Normally, when connecting the hitch frame 2 to the work implement, the operator pays close attention to the height setting of the hitch frame 2 with respect to the rotary tiller 8, whereas when removing the hitch frame 2, it is relatively rough. Since the hydraulic cylinder for performing the operation and tilting the lift arm 5 up and down is a single-acting type, if the operating lever of the hydraulic cylinder is lowered too much, the hitch frame 2 will have its own weight, yoke joint weight, lower links 4, 4, etc. Since the front connecting tools A, A collide with the upper surface of the front part of the rotary cover 11 because they fall rapidly due to the weight of, the upper front connecting tool B is received by the receiving metal 23 and further descends. At this time, if the ground contact surface is hard, the rear guide surface 19 of the front connecting device B is curved so that the rear side becomes higher and the above-mentioned load is applied, so that the rotary tiller 8 retracts. ,
If the ground contact surface is soft, the rotary tiller 8 will not retreat. Therefore, if the tractor is advanced a little, the front couplings A, A will not collide with the rotary cover 11.

(G) Effect of the Invention According to the present invention configured as described above, even if the connecting point of the lower part is set to the upper part near the front part of the work machine in order to improve the traveling property of the machine body, When the hitch frame 2 is disengaged, the upper front connecting device B is received by the receiving metal 23 and does not drop, so that the front connecting device A on the front side of the working machine or on both sides of the lower part of the hitch frame 2, Does not damage or deform A.

Also, when the hitch frame 2 is connected to the working machine,
Positioning, which can also be used for positioning and guiding the upper connector of the hitch frame 2, can be easily performed.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a side view of a main part, and FIG. 2 is a side view showing a state in which a front connecting tool at an upper portion of a hitch frame is in contact with a receiving metal. FIG. 3 is a plan view of the state shown in FIG. 1, FIG. 4 is a side view showing a state immediately before connecting the hitch frame to the working machine, and FIG. 5 is a state in which the working machine is lifted by the hitch frame. It is a side view shown. 2 ... Hitch frame, 3 ... Top link, 4 ... Lower link, 5 ... Lift arm, 8 ... Rotary work machine, 11 ...
… Rotary cover, 17 …… Receiving groove, 20 …… Top mast,
22 …… Mast stay, 27 …… Upper connecting pin, 30 …… Lower connecting pin, A, B …… Front connecting tool

Claims (1)

[Scope of utility model registration request] 1. A lifting link (3) at the rear of the tractor,
The hitch frame (2) is attached via the (4) so as to be able to move up and down, and the front connecting members (A) and (B) are attached to the upper center and both sides of the lower part of the hitch frame (2), in front of the working machine. In the tractor in which the rear connecting tools corresponding to the front connecting tools (A) and (B) are attached to the center of the upper part and both sides of the lower part, the work machine is attached to and detached from the hitch frame (2). The member that supports the rear connecting tool at the center of the upper part of the machine is connected to the lower connecting path of the front connecting tool (B) mounted on the upper center of the hitch frame (2) when the connecting / disconnecting work is performed. ) Is attached to the front connector (B), and the front connector (B) receives the front connector (B) when the front connector (B) comes into contact with the money receiver (23) when the front connector (B) descends and the hitch frame (2). A hitch device for a tractor, characterized in that a rear guide surface (19) for guiding the work machine and the working machine in a separating direction is formed. .