JPH0626086Y2 - Work implement locking device for agricultural tractors - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a hitch device for attaching and detaching a working machine to a rear portion of an agricultural tractor via a link and a hitch frame.

(B) Conventional technology Conventionally, hooks that open upward are provided on the upper and lower sides of the hitch frame as a hitch device for attaching and detaching the working machine via a link and a hitch frame at the rear part of the agricultural tractor, and the front part of the working machine is provided. A connecting pin corresponding to each of the hooks is provided, the hitch frame is raised from a lowered position, each hook is hooked to the connecting pin to connect, and the hook is locked by a downward hook biased by a spring. The above-mentioned one is already known from Japanese Utility Model Publication No. 60-131105.

In addition, the hook and connecting pin are installed in reverse relation to the hitch frame and the working machine, and the hitch device in the agricultural tractor in which a lock pin that is inserted and removed from the rear is attached to the frame attached to the working machine is actually opened. It is already known from JP 61-505006.

(C) Problems to be solved by the device Among the known devices, the former needs to make the connecting pin attached to the working machine stand by at a position corresponding to the upward trajectory of the hook attached to the hitch frame. Preparatory work is troublesome because the working machine has to be corrected to a predetermined posture with a stand, and the only means for holding the state in which the connecting pin is fitted to the hook is the hook biased by the spring It was not possible to maintain a proper locked state.

In addition, the latter has the same problems as the former in that it requires preparatory work, and since the lock pin is inserted into and removed from the frame of the working machine from the rear, the operator gets off each time, or The assistant had to operate the lock pin.

(D) Means for Solving the Problems The present invention connects a hitch frame having engaging parts on both upper and lower sides to the rear ends of a top link and a lower link connected to the rear part of the machine body. In an agricultural tractor configured to connect a working machine to a frame, connecting pins protruding from both sides of a lower part of the working machine are fitted to a longitudinally and substantially vertical connecting plate attached to a lower part of the hitch frame. A groove having an opening at the rear is provided, and a locking plate that fits into the connecting pin and rotates following the movement of the connecting pin is rotatably pivotally supported on the connecting plate. A lateral lock pin that can be inserted into and removed from the lock hole is attached to the connecting plate by urging and urging the connecting plate, and the lock pin is linked to the operation lever, and the guide groove of the lever panel 28 that holds the operation lever.
28a is a long hole along the operating direction, and the end portion on the side where the operating lever 27 is locked is formed in a bent portion, and the operation lever is pulled and biased obliquely toward the bent portion. The above problem was solved by attaching a spring 30.

(E) Action When the work implement is placed on the ground, the lower connecting pin is located behind the upper connecting pin, so the work implement is connected to the rear part of the agricultural tractor via a link. When connecting to the frame, when the agricultural tractor is retracted toward the working machine and the upper engaging part of the hitch frame engages with the engaging member of the working machine and is lifted, the lower part of the working machine engages upward. Part of the work machine, the connecting pins provided on both sides of the lower part of the work machine fit into the grooves provided on the connecting plates on both sides of the lower part of the hitch frame, and the locking plates engage with the connecting pins accordingly. When the connecting pin is driven into the groove of the connecting plate and penetrates into the groove of the connecting plate, the lock pin held by the plate surface of the locking plate fits into the hole of the locking plate and also by the tension spring attached to the operation lever. The lock pin is pushed in The locked state can be reliably retained.

Without connecting the operation lever when connecting the work machine. The operation lever automatically moves along the guide groove in the direction in which the lock pin is fitted by the tension spring,
When it reaches the end of the guide groove, it is pulled into the bent portion of the guide groove by the tension spring, so the lock pin is biased by fitting and the operation lever linked to it is fitted by the tension spring. The biased state and the fact that the operation lever is fitted and locked in the bent portion are able to reliably maintain the locked state.

(F) Embodiments An embodiment of the present invention will be described with reference to the drawings. 1 is a mission case of an agricultural tractor. Connect the front end of the top link 4 to the bracket 3
At the rear ends of the top link 4 and the lower links 2 and 2, the upper center and the lower ends of a hitch frame 5 are connected, and the hitch frame 5 includes a portal frame 6 as a main frame and its upper part. A connecting plate 7 fixed to the center and having a front portion connected to the rear end of the top link 4 with a pin and an upward hook-shaped engaging portion 7a at the rear portion, and holes 8c, 8c.
The two connecting plates 8a, 8a that are vertical in the front-rear direction
It is composed of a connecting frame 8 which is connected by b and has an inner connecting plate 8a fixed to the lower outer side of the gate type frame 6, and a plate 9 having a U-shaped cross section which connects the lower part of the gate type frame 6. The connecting plates 8a, 8a of the connecting frame 8 are provided with substantially horizontal grooves 10 with their rear portions opened, and the locking plate 11 superposed on the connecting plate 8a on the outer side is a working machine 12 which will be described later. Has a locking groove 13 that opens upward in the state where it is mounted, and the rear end of the lower links 2 and 2 is provided in the hole 11a of the locking plate 11 and the holes 8c and 8c of the connecting plates 8a and 8a. Insert pin 15 of washer 16 and C
The lower parts of both sides of the hitch frame 5 are attached to the rear parts of the lower links 2 and 2 by being stopped by the pin 17 and the locking plate
11 is pivotally supported.

Also, the upper portions of the connecting plates 8a, 8a of the connecting frame 8 and the locking plate 11
In the upper part of the work machine 12, the locking hole 1
8, 18 and lock holes 19 are formed, and the lock pin 20 inserted through the locking holes 18, 18 is a guide pin 22 loosely fitted in a lateral long hole 21 formed in the curved plate 8b. There is a spring 23 between the guide pin 22 and the inner connecting plate 8a, which holds the state in which the lock pin 20 is pushed outward and biased to be fitted in the lock hole 19. The inner ends of the rods 25, 25 screwed into the inner ends of the left and right lock pins 20, 20 are supported by the support shaft 26 of the operating lever 27 which is rotatably supported by the support shaft 26 on the plate 9 such that the lower end thereof is pivotally supported by the support shaft 26. Is rotatably connected to the upper and lower parts of the control lever 27, and the guide groove 28a of the lever panel 28 in which the upper part of the operation lever 27 is loosely fitted has a bent portion at the inner end as shown in FIGS. And the operating lever 27 has a tension spring.
It is urged by 30 so that it is located closer to the center of the machine width, that is, the lock pin 20 is maintained in the locked state.

Further, a spring plate (a spring rod is also acceptable) 29 screwed vertically on the outer surface of the locking plate 11 is bent inward at a portion corresponding to the upper edge of the locking plate 11 and slightly forward. The inner end of the guide pin 22 with the lock pin 20 unlocked.
Is designed to be locked.

The working machine 12 is a rotary cultivator, which is an example of the working machine 12, and has a tail wheel 31 in the rear part and a top mast standing in the front part.
The rear portion of the connecting metal 33 composed of two plates is fixed to 32, and the hook-shaped engaging portion 7a of the connecting plate 7 is engaged from below with the pin 35 fixed to the front portion thereof, and from both sides of the lower portion to the front. To the connecting plates 36, 36 that are extended to the above, lateral connecting pins 37 that are fitted into the grooves 10, 10 of the connecting plates 8a, 8a and the locking groove 13 of the locking plate 11 are fixed.

Further, a shaft 40 projecting rearward from a rear part of a yoke 39, the front part of which is connected to the PTO shaft 38 of the agricultural tractor, is provided in a round hole 41 formed in the center of the plate 9 to which the lower part of the hitch frame 5 is connected. The dock clutch 42, which is inserted and supported through a bearing, a holder, and a ring-shaped rubber cushioning material, is spline-fitted and fixed to the shaft 40.
It engages with a dock clutch 45 attached to 12 input shafts 43 and transmits. 46 is a cover.

FIG. 1 shows a standby state or a detached state in which the working machine 12 is connected to the hitch frame 5, and FIGS. 2, 5, and 8 show a connection preparation state in which the locking plate 11 is rearward. Since the opening of the locking groove 13 is aligned with the groove 10 and the lock hole 19 is almost directly above the pin 15, the operating lever 27 is in this state when the working machine was previously removed. By the operation of No. 10
At the position shown in the figure, the lock pin 20 is pulled out and the tip thereof is received by the inner side surface of the locking plate 11 and held at the position shown in FIG. When connecting the working machine 12 in this state,
When the agricultural tractor is retracted toward the working machine 12 and the lower links 2 and 2 are pulled up by the lift arm 47 via a lift rod (not shown), the hitch frame 5 rises, and first, the engaging portion 7a is pinned. The upper part of the working machine 12 is lifted by hanging on 35, whereby the working machine 12 is rotated about the pin 35 so that the lower part advances. Thereby, the connecting pin
37 penetrates into the grooves 10, 10 of the connecting plates 8a, 8a and pushes forward the front part of the front of the locking groove 13 of the locking plate 11 to rotate it, and the connecting pin 37 causes the groove of the connecting plates 8a, 8a to rotate. When it reaches the deepest part of 10, 10, the locking groove 13 of the locking plate 11 faces upward to lock the connecting pin 37, and the lock hole 19 of the locking plate 11 locks the connecting plates 8a, 8a. Hole 18,
Since it coincides with 18, the lock pin 20 received by the plate surface of the locking plate 18 is automatically inserted into the lock hole 19 as shown in FIG. 3 by the pressing force of the springs 23 and 30. 6A, the spring plate 29 is in contact with the guide pin 22 and follows the elongated hole 21 as shown in FIG. 6B. Further, since the operation lever 27 is pulled by the tension spring 30 toward the center side and the rear side of the machine width, as shown in FIG.
Since the springs 30 and 23 urge the lock pin 20 by pushing it in, the lock pin 20 does not come out due to vibration of the machine body or other external force, and the lock pin 20 is substantially vertical connecting plate 8a in the front-rear direction. 8a and the locking plate 11 with the horizontal lock pin 2
Since the connection is 0, it is possible to firmly connect both in the front-rear direction and in the up-down direction.

Next, when the work implement 12 is removed, the operator extends the right hand backward from the driver's seat of the agricultural tractor, pulls the operation lever slightly forward, and pivots outward to the position shown in FIG. Left and right lock pins 20,20 via
Is pulled out against the springs 23, 23, and the guide pin 22 is disengaged from the lateral portion of the spring plate 29 and is received by the bent portion at the tip to maintain the unlocked state, that is, FIG. When the agricultural tractor is advanced in the state shown in FIG. 7 and FIG. 7, the hitch frame 5 advances with respect to the working machine 12, the grooves 10, 10 of the connecting plates 8a, 8a are separated from the connecting pin, and the locking plate is interposed therebetween. When 11 rotates a little backward, the guide pin 22
Is released from the spring plate 29 and extruded, but its tip is received by the locking plate 11, and when the locking plate 11 is further rotated, it is in the detached state shown in FIGS. 2, 5, and 10. And it returns to the connection preparation state.

(G) Effect of the Invention Since the present invention is configured as described above, it is possible to automatically remove the working machine from the hitch frame 5 by releasing the operating lever 27. When mounted on the hitch frame 5, the operating lever 27 can be pulled by the tension spring 30 and automatically moved in the direction in which the lock pin 20 is fitted along the guide groove 28a, and the operating lever 27 is locked when the working machine is connected. The entering operation can be omitted.

Further, in the state in which the working machine is connected to the hitch frame 5, the lock pin 20 is biased in and the tension spring 30 biases the operating lever 27 in the direction in which the lock pin is fitted. In combination with the fact that the guide groove 28a is pulled into the bent portion of the guide groove 28a to be engaged with the bent portion so as not to move forward and backward, the locked state can be firmly maintained.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a side view of a rear part of an agricultural tractor and a working machine, and FIG. Is a front view of the same as above showing a mounting completed state, FIG. 4 is a front view of the same as a detaching preparation state, FIG. 5 (a) is a side view in the state of FIG. 2, and (b) is
6A is a side view of the state of FIG. 3,
7B is a side view of the state of FIG. 4, FIG. 7B is a side view of FIG. 4A of FIG. 8A, FIG. FIG. 10 is a plan view showing the operating position of the operating lever. 2 ... Lower link, 4 ... Top link, 5 ... Hitch frame, 6 ... Gate frame, 8a ... Connecting plate, 10 ...
Groove, 11 ... Locking plate, 12 ... Working machine, 13 ... Locking groove, 19 ...
… Lock hole, 20 …… Lock pin, 22 …… Guide pin, 23
...... Spring, 25 …… Rod, 27 …… Operating lever, 30
...... Tension spring, 36 ...... Connecting plate, 37 ...... Connecting pin

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. A top link 4 and a lower link 2, 2 which are connected to the rear part of the machine body.
In an agricultural tractor in which a hitch frame 5 having a 7a is connected and a working machine is connected to the hitch frame 5, a working machine is attached to a connecting plate 8a which is attached to a lower portion of the hitch frame 5 and which is substantially vertical in the front-rear direction. A groove 10 having a rear opening is provided so that the connecting pins 37 projectingly provided on both lower sides of 12 are fitted, and the locking plate 11 which fits to the connecting pin 37 and rotates following the movement thereof is provided. The connecting plate 8a is rotatably rotatably supported in the overlapping state, and a lateral lock pin 20 that can be inserted into and removed from the lock hole 19 of the locking plate 11 is inserted into the connecting plate 8a by urging and attached. The lock pin 20 is connected to the operation lever, and the guide groove 28a of the lever panel 28 holding the operation lever is formed into an elongated hole along the operation direction, and the end portion on the side where the operation lever 27 is locked is bent. Formed on the operation lever 27 and inclined toward the bent portion. Working machine locking device in agricultural tractor, characterized in that the 30 tensile spring for urging tension was attached to.