Three-point hanging and connecting method for automatic hanging and connecting of farm tools

Abstract

The invention discloses a three-point suspension hooking method for automatic hooking of a farm tool, which comprises the following steps: S1, carrying out backing adjustment according to the orientation of the farm tool, S2, adjusting a lower hook according to interface information, S3, judging whether the farm tool is parallel or not and adjusting the angle, S4, continuing backing, adjusting and hooking the lower hook, S5, adjusting and hooking an upper hook, S6, recovering the initial state, adjusting and hooking shaft power, and S5, automatically hooking the farm tool. S7, hooking and separating; compared with a traditional hitching method, in the reversing hitching process of the tractor, middle parking is only conducted once before final parking, the parking state is kept for angle adjustment during middle parking, reversing continues after angle adjustment, and in the whole reversing process, the tractor does not advance to adjust the angle of the tractor head; the invention innovatively provides a novel structure combination method to achieve the purpose of quick hooking, the hooking time can be greatly shortened, additional personnel intervention is not needed in the hooking process, hooking can be completed by one driver, labor force can be reduced, and efficiency can be improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of tractors, and particularly relates to a three-point suspension hitching method for automatic hitching of agricultural implements. BACKGROUND

[0002] With the development of global agricultural scale and intensification, the demand for efficient hitching devices suitable for large horsepower tractors has increased to improve work efficiency. This scale of operation mode promotes higher requirements for the efficiency and convenience of agricultural production in terms of agricultural implement hitching, and promotes the development of automatic hitching devices.

[0003] The traditional agricultural implement hitching method mainly relies on manual operation, which has many problems. For example, the hitching process takes a long time and depends on the experience of the driver. The operator needs to repeatedly adjust the position and angle of the tractor. The tractor needs to reverse, advance, adjust the angle, and then reverse again. The reverse and forward operations are repeated several times to achieve the alignment connection of the agricultural implement and the tractor. However, there is a lack of multi-directional adjustment function, and the hitching error is large. At the same time, manual hitching is labor-intensive, especially in the hitching of large agricultural implements, which requires multiple people to operate cooperatively, and there is a high safety risk, which is difficult to meet the needs of modern efficient agricultural production. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a three-point suspension hitching method for automatic hitching of agricultural implements, which utilizes the cooperation of beam rotation and hook translation adjustment, and can quickly complete hitching without repeated reversing.

[0005] To solve the above technical problems, the technical solution of the present application is as follows: a three-point suspension hitching method for automatic hitching of agricultural implements, comprising the following steps: S1. After the driver selects the agricultural implement to be hitched, the main controller of the hitching implement behind the tractor communicates with the secondary controller of the selected agricultural implement. The main controller obtains the position information and interface orientation information of the agricultural implement. The main controller positions the agricultural implement according to the position information and judges the orientation of the agricultural implement interface according to the interface orientation information. The position and direction of the agricultural implement are displayed on the display screen in the cab, and the driver controls the tractor to reverse towards the agricultural implement interface; S2. During the reversing process, the main controller obtains the interface position information and ground clearance information of the agricultural implement. The main controller obtains the distance between the left lower hanging point and the right lower hanging point of the agricultural implement according to the interface position information, and defines it as L. Then, according to the left hook positioner and the right hook positioner, the main controller obtains the distance between the left lower hook and the right lower hook of the hitching implement, and defines it as L1. Then, it is judged whether L1 is equal to L. When L1≠L, the left lower oil cylinder and the right lower oil cylinder are controlled to synchronously extend and retract in the left-right direction for adjustment until L1=L is stopped. During the extension and retraction of the oil cylinder, the upper oil cylinder assembly is controlled to swing the upper hook upward to avoid the agricultural implement; The main controller obtains the height of the left lower hanging point and the right lower hanging point of the agricultural implement relative to the ground according to the ground clearance information, and defines the height as H. The main controller obtains the height of the left lower hook and the right lower hook of the hanger relative to the ground according to the left hook positioner and the right hook positioner, and defines the height as H1. Then, the main controller judges the size of H1 and H. When H1+10cm≥H, the main controller controls the lifting assembly to drive the left lower hook and the right lower hook to simultaneously descend until H1+10cm<H. During the reversing process, the main controller and the secondary controller communicate in real time. When one of the lower hooks of the hanger moves to the lower area between the two lower hanging points of the agricultural implement, the reversing is stopped. S3. The main controller obtains the line between the two lower hanging points according to the interface position information of the agricultural implement, and defines the line as AB. The main controller obtains the line between the two lower hooks according to the left hook positioner and the right hook positioner, and defines the line as AB1. Then, the main controller judges whether AB is parallel to AB1. When AB is not parallel to AB1, the main controller calculates the deviation angle and the deviation direction between AB and AB1, converts the deviation angle into the number of rotations of the angle adjusting motor, controls the rotary locking device to be unlocked, and then controls the angle adjusting motor to rotate quantitatively according to the number of rotations and the direction, so as to drive the rear beam frame and the two lower hooks mounted on the rear beam frame to rotate as a whole until AB is parallel to AB1. S4. The tractor continues to reverse, driving the two lower hooks of the hanger to move towards the agricultural implement, and stops reversing when the two lower hooks move below the two lower hanging points of the agricultural implement. The main controller obtains the distance between the left lower hook and the left lower hanging point in the left-right direction according to the positions of the left lower hook and the left lower hanging point, and obtains the distance between the right lower hook and the right lower hanging point in the left-right direction according to the positions of the right lower hook and the right lower hanging point. The main controller controls the left lower oil cylinder and the right lower oil cylinder to act according to the obtained distances. The left lower oil cylinder and the right lower oil cylinder act synchronously, one extends and one retracts, and the extension amount is equal to the retraction amount. When the left lower hook is located directly below the left lower hanging point and the right lower hook is located directly below the right lower hanging point, the two oil cylinders stop. The main controller controls the lifting assembly to drive the left lower hook and the right lower hook to simultaneously move upwards. During the lifting process, the pins at the left lower hanging point and the right lower hanging point of the agricultural implement press the left lower hook and the right lower hook to open, and are locked after being hung, so as to complete the automatic hanging of the left lower hanging point and the left lower hook and the automatic hanging of the right lower hanging point and the right lower hook. S5. The main controller controls the upper oil cylinder assembly to act according to the relative positions of the upper hanging point of the agricultural implement and the upper hook of the hanger, so as to drive the upper hook to move from top to bottom and approach the upper hanging point. The pin at the upper hanging point presses the upper hook to open, and is locked after being hung, so as to complete the automatic hanging of the upper hanging point and the upper hook. S6, after the three hanging points are all connected, the main controller controls the lifting assembly and the oil cylinder assembly to act, driving the farm tool to leave the ground; then, the angle adjusting motor is controlled to act, and the angle adjusting motor rotates reversely according to the number of revolutions, driving the rear beam frame and the whole farm tool to rotate reversely and restore the initial state, and then the rotary locking device is powered off to lock; During the rotation of the farm tool, the oil cylinder assembly, the left lower oil cylinder and the right lower oil cylinder act synchronously to make adaptive adjustment, and finally the left lower oil cylinder and the right lower oil cylinder have the same extension amount, the plane where the upper hook, the left lower hook and the right lower hook are located is perpendicular to the ground, and then the main controller controls the power docking oil cylinder to extend, driving the spline shaft sleeve to move towards the farm tool, the spline shaft sleeve is inserted into the spline shaft of the farm tool, and the power of the tractor is transmitted to the farm tool through the shaft coupling, the spline shaft sleeve and the spline shaft, so that the power docking between the hitch and the farm tool is completed. S7, the main controller first controls the power docking oil cylinder to retract, disconnecting the spline shaft sleeve and the spline shaft, then controls the lifting assembly and the oil cylinder assembly to place the farm tool on the ground, controls the upper hook, the left lower hook and the right lower hook to be unlocked, then drives the upper hook to move upwards and be separated from the upper hanging point through the action of the oil cylinder assembly, and drives the left lower hook and the right lower hook to move downwards and be separated from the left lower hanging point and the right lower hanging point through the action of the lifting assembly, and the tractor advances, so that the farm tool and the hitch are completely separated.

[0006] As a preferred technical solution, the hitch comprises an upper hanging point module and a lower hanging point module, The upper hanging point module comprises an upper hook and an oil cylinder assembly, the front end of the oil cylinder assembly is connected to the rear axle of the tractor, and the upper hook is arranged at the rear end of the oil cylinder assembly. The lower hanging point module comprises a front beam frame, a rear beam frame, a left lower hook and a right lower hook, the left and right ends of the front beam frame are respectively connected with telescopic connecting arms, the telescopic connecting arms are connected to the rear axle of the tractor at the end portions, and a lifting assembly is arranged between the telescopic connecting arms and the rear axle of the tractor; a rotary adjusting device is arranged between the front beam frame and the rear beam frame, an angle adjusting motor is arranged on the front beam frame, the angle adjusting motor drives the rear beam frame to rotate through the rotary adjusting device, a rotary locking device is arranged on the front beam frame to lock or unlock the rotary adjusting device; a left telescopic hanging arm and a right telescopic hanging arm are respectively arranged on the left end and the right end of the rear beam frame in a transverse sliding mode, the left lower hook is arranged at the lower part of the left end of the left telescopic hanging arm, a left lower oil cylinder is arranged between the left telescopic hanging arm and the rear beam frame, the right lower hook is arranged at the lower part of the right end of the right telescopic hanging arm, a right lower oil cylinder is arranged between the right telescopic hanging arm and the rear beam frame, and a power docking device connected with the rear output end of the tractor is mounted on the middle part of the rear beam frame.

[0007] As a preferred technical scheme, the rotating adjusting device comprises a front beam connecting frame fixed to the front beam frame and a rear beam connecting frame fixed to the rear beam frame, the rear beam connecting frame is clamped between the front beam connecting frames and connected through a rotating shaft, a driven gear is fixed to the rear beam connecting frame at the axis line of the rotating shaft, an output end of the angle adjusting motor is provided with a driving gear, the driving gear and the driven gear are connected through an intermediate gear, and the rotating locking device is connected with the intermediate gear to be locked or unlocked.

[0008] As a preferred technical scheme, the rotating locking device comprises a fixing block fixed to the front beam frame, a lock tongue slidingly arranged in the fixing block, a locking tooth arranged at an inner end of the lock tongue, a locking tension spring arranged between an outer end of the lock tongue and the fixing block, a lock tongue gear rack arranged at the outer end of the lock tongue, and an unlocking motor fixed to the front beam frame, wherein an output end of the unlocking motor is provided with an unlocking gear, and the unlocking gear is engaged with the lock tongue gear rack.

[0009] As a preferred technical scheme, the power docking device comprises a mounting shell fixed to the rear beam frame, a bearing seat slidingly arranged in the mounting shell, a spline shaft sleeve rotatingly arranged in the bearing seat, a coupling connected to a front end of the spline shaft sleeve, and an inner spline machined at a rear end of the spline shaft sleeve, wherein a power docking oil cylinder is arranged between the mounting shell and the bearing seat, the power docking oil cylinder drives the bearing seat to slidingly extend or retract, so that the spline shaft sleeve is combined with or separated from the spline shaft.

[0010] As a preferred technical scheme, the left lower hook comprises a first hook seat, a first hooking pin hole and a first hooking opening communicated with the first hooking pin hole are arranged in the first hook seat, a first sliding block guide groove is arranged in the first hook seat corresponding to the first hooking opening, a first hooking sliding block is slidingly arranged in the first sliding block guide groove, a first guide arc surface curved towards one side of the first hooking pin hole is arranged at an opening end of the first hooking sliding block, a first locking tension spring is arranged between a tail end of the first hooking sliding block and the first hook seat, a first locking positioning member is arranged between the first hooking sliding block and the first hook seat, and a first electric control unlocking device overcoming the first locking tension spring is further arranged on the first hooking sliding block; the first electric control unlocking device comprises a first unlocking motor arranged on the first hook seat, an output end of the first unlocking motor is provided with a first unlocking gear, a first sliding block gear rack is arranged on a side surface of the first hooking sliding block away from the first hooking pin hole, and the first unlocking gear and the first sliding block gear rack are connected in transmission.

[0011] As a preferred technical scheme, the right lower hook comprises a second hook base, a second hooking pin hole and a second hooking opening communicated with the second hooking pin hole are arranged in the second hook base, a second sliding block guide groove is arranged in the second hook base corresponding to the second hooking opening, a second hooking sliding block is slidingly installed in the second sliding block guide groove, a second guide arc surface curved towards one side of the second hooking pin hole is arranged at an opening end of the second hooking sliding block, a second locking tension spring is arranged between a tail end of the second hooking sliding block and the second hook base, a second locking positioning piece is arranged between the second hooking sliding block and the second hook base, and a second electric control unlocking device overcoming the second locking tension spring is further arranged on the second hooking sliding block; the second electric control unlocking device comprises a second unlocking motor arranged on the second hook base, a second unlocking gear is installed at an output end of the second unlocking motor, a second sliding block rack is arranged on a side surface of the second hooking sliding block away from the second hooking pin hole, and the second unlocking gear and the second sliding block rack are in transmission cooperation.

[0012] As a preferred technical scheme, the upper hook comprises a third hook base, a third hooking pin hole and a third hooking opening communicated with the third hooking pin hole are arranged in the third hook base, a third sliding block guide groove is arranged in the third hook base corresponding to the third hooking opening, a third hooking sliding block is slidingly installed in the third sliding block guide groove, a third guide arc surface curved towards one side of the third hooking pin hole is arranged at an opening end of the third hooking sliding block, a third locking tension spring is arranged between a tail end of the third hooking sliding block and the third hook base, a third locking positioning piece is arranged between the third hooking sliding block and the third hook base, and a third electric control unlocking device overcoming the third locking tension spring is further arranged on the third hooking sliding block; the third electric control unlocking device comprises a third unlocking motor arranged on the third hook base, a third unlocking gear is installed at an output end of the third unlocking motor, a third sliding block rack is arranged on a side surface of the third hooking sliding block away from the third hooking pin hole, and the third unlocking gear and the third sliding block rack are in transmission cooperation.

[0013] As a preferred technical scheme, the telescopic connecting arm comprises a supporting arm and an extension arm slidingly sleeved in the supporting arm, a positioning hole is arranged between the supporting arm and the extension arm, a rear end of the supporting arm is fixed on the front beam frame, a connecting fulcrum plate is further arranged at a top of the rear end of the supporting arm, and an extension arm connecting hole is arranged at a front end of the extension arm.

[0014] As a preferred technical scheme, the upper oil cylinder assembly comprises an upper oil cylinder one and an upper oil cylinder two, one end of the upper oil cylinder one is hingedly connected to the rear axle of the tractor, the upper hook is arranged at the other end of the upper oil cylinder one, one end of the upper oil cylinder two is hingedly connected to the rear axle of the tractor, and the other end of the upper oil cylinder two is hingedly connected to the upper oil cylinder one.

[0015] With the above technical solutions, the application has the advantages that the hanger can adjust the positions and distances of the two lower hooks and the upper hook, and can adapt to various sizes of three-point suspension agricultural implements. Meanwhile, the power docking device can be extended to adapt to the agricultural implement with power input. The hanger can rotate an angle, so even if the driver is not skilled in reversing, the hanger can be adjusted within a certain range, and the driver no longer needs to repeatedly reverse to find the connection position and angle as in the traditional hanger. During the reversing process of the tractor, only two stops are needed. At the first stop, the two key actions are angle adjustment and hook translation. The direction of the hanger is directly changed through angle adjustment to adapt to the angle of the agricultural implement, and then the left and right lower hooks are synchronously translated to change the position of the hook relative to the two lower hanging points in the left-right direction, so as to realize the effect that the two lower hooks are parallel to the two lower hanging points and consistent in the left-right direction. During the adjustment process, the tractor is always kept in a stopped state, and the effect that the tractor is not moving but can be fully adapted to the lower hanging point is achieved. The second stop is the final stop, and the hanging point is connected and the power is docked, so the second stop is the same as the final stop in the traditional connection method. Compared with the traditional connection method, the hanger connection method of the application only needs to stop once in the middle before the final stop during the tractor reversing connection process, and the angle is adjusted while keeping the stopped state during the middle stop. After the angle adjustment, the tractor continues to reverse, and the tractor never advances to adjust the angle during the entire reversing process. In the prior art, in order to adapt to the angle of the agricultural implement, the angle of the tractor head needs to be repeatedly adjusted, so the tractor repeatedly advances and reverses until the hanger is parallel to the agricultural implement. This adjustment method has large errors, low efficiency, and is time-consuming and labor-intensive. However, the current prior art can only use this method for adjustment, but the application provides a new structure combination method to achieve fast connection, which can greatly reduce the connection time and does not require additional personnel intervention during the connection process. One driver can complete the connection, which can reduce labor and improve efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0016] The following drawings are only intended to illustrate and explain the application, and do not limit the scope of the application. Among them: Figure 1 is a side view of the hanger of the embodiment of the application; Figure 2 is a structural schematic view of the hanger of the embodiment of the application; Figure 3 is a structural schematic view of the lower hanging point module of the embodiment of the application; Figure 4 is a structural schematic view of the lower hanging point module of the embodiment of the application from another angle; Figure 5 is a top view of the lower hanging point module of the embodiment of the application in the initial state; Figure 6 is a top view of the hanging point module after angle adjustment according to an embodiment of the present application; Figure 7 is a structural schematic diagram of the rotating locking device according to an embodiment of the present application; Figure 8 is a top view of the power docking device according to an embodiment of the present application; Figure 9 is a structural schematic diagram of the power docking device according to an embodiment of the present application; Figure 10 is a structural sectional view of the power docking device according to an embodiment of the present application; Figure 11 is a structural schematic diagram of the left lower hook according to an embodiment of the present application; Figure 12 is a structural sectional view of the left lower hook according to an embodiment of the present application; Figure 13 is a structural schematic diagram of the farm implement according to an embodiment of the present application; Figure 14 is a block diagram of the automatic hitching method according to an embodiment of the present application; Figure 15 is a simple diagram of the hitching state according to an embodiment of the present application; Figure 16 is a state diagram of the hitch before the hitch of the hitch and the farm implement according to an embodiment of the present application; Figure 17 is a state diagram of the lowering of the lower hook below the lower hanging point according to an embodiment of the present application; Figure 18 is a state diagram of the movement of the lower hook to directly below the lower hanging point according to an embodiment of the present application; Figure 19 is a state diagram of the hitch of the lower hook and the lower hanging point according to an embodiment of the present application; Figure 20 is a state diagram of the hitch of the upper hook and the upper hanging point according to an embodiment of the present application; Figure 21 is a state diagram of the hitch of the power docking device according to an embodiment of the present application; In the figure: A-hitch; 10-upper hanging point module; 11-upper hook; 12-upper oil cylinder assembly; 12a-upper oil cylinder one; 12b-upper oil cylinder two; 20-lower hanging point module; 21-front beam frame; 22-rear beam frame; 23-left lower hook; 23a-first hook seat; 23b-first hooking pin hole; 23c-first hooking sliding block; 23d-first locking tension spring; 23e-first unlocking motor; 23f-first unlocking gear; 23g-first sliding block rack; 24-right lower hook; 25-extendable connecting arm; 25a-supporting arm; 25b-extending arm; 25c-connecting support point plate; 25d-extending arm connecting hole; 26-lifting assembly; 26a-adjusting rod; 26b-lifting arm; 26c-lifting hydraulic cylinder; 27-rotary adjusting device; 27a-front beam connecting frame; 27b-rear beam connecting frame; 27c-passive gear; 27d-driving gear; 27e-intermediate gear; 28-angle adjusting motor; 29-rotary locking device; 29a-fixing block; 29b-locking tongue; 29c-locking tooth; 29d-locking tension spring; 29e-unlocking motor; 29f-unlocking gear; 210-left extendable hooking arm; 211-right extendable hooking arm; 212-left lower oil cylinder; 213-right lower oil cylinder; 214-power docking device; 214a-mounting shell; 214b-bearing seat; 214c-guiding shaft; 214d-keyed shaft sleeve; 214e-coupling; 214f-extendable cylinder; 214g-lengthening plate; 214h-power docking oil cylinder; 30-main controller; 40-tractor rear axle; B-farm implement; 50-upper hanging point; 60-left lower hanging point; 70-right lower hanging point; 80-keyed shaft; 90-secondary controller. DETAILED DESCRIPTION

[0017] The present application is further described below in conjunction with the accompanying drawings and examples. In the following detailed description of the application, certain exemplary embodiments of the application are described by way of illustration only. It will be apparent to those skilled in the art that the embodiments described can be practiced in various ways without deviating from the spirit and scope of the application. Therefore, the drawings and description are to be regarded as illustrative in nature and not restrictive.

[0018] The hitching of tractor farm implements is the suspension connection and power connection between the hitch A and the farm implement B. The farm implement B is generally placed on the ground, while the hitch A is connected to the tail end of the tractor. The tractor drives the hitch A to reverse and dock with the farm implement B. For agricultural production of a certain scale, the hitch A needs to be docked and matched with various different specifications of farm implement B, and therefore the hitch A and the farm implement B need to be adaptively designed.

[0019] As Figure 1 and Figure 2As shown, the hanger A includes an upper hanging point module 10, a lower hanging point module 20 and a main controller 30, the upper hanging point module 10 and the lower hanging point module 20 are independent of each other and are respectively installed on the tractor rear axle 40, the upper hanging point module 10 and the lower hanging point module 20 cooperate to form a three-point suspension, the main controller 30 is arranged on the lower hanging point module 20, used for acquiring and controlling the posture and position of the upper hanging point module 10 and the lower hanging point module 20, and cooperating with the tractor inner controller and the secondary controller in the farm tool B. In this embodiment, combined with Figure 1 and Figure 2 , the tractor rear axle 40 refers to the gearbox housing located at the rear of the tractor.

[0020] Referring to Figure 1 and Figure 2 , the upper hanging point module 10 includes an upper hook 11 and an upper cylinder assembly 12, the upper cylinder assembly 12 is used for adjusting the position of the upper hook 11, the front end of the upper cylinder assembly 12 is connected to the tractor rear axle 40, and the upper hook 11 is arranged at the rear end of the upper cylinder assembly 12.

[0021] The upper cylinder assembly 12 includes an upper cylinder one 12a and an upper cylinder two 12b, the front end of the upper cylinder one 12a is hinged to the tractor rear axle 40, the upper hook 11 is arranged at the rear end of the upper cylinder one 12a, the upper cylinder two 12b is arranged above the upper cylinder one 12a, and the front end is hinged to the tractor rear axle 40, the rear end of the upper cylinder two 12b is hinged to the upper cylinder one 12a, the upper cylinder one 12a is used for controlling the extension and retraction, the upper cylinder two 12b is used for controlling the inclination angle of the upper cylinder one 12a, and the upper cylinder one 12a and the upper cylinder two 12b cooperate to change the position of the upper hook 11, used for adapting the upper hanging point of the farm tool B.

[0022] The upper hook 11 is correspondingly provided with an upper positioner, which is used for collecting three-dimensional coordinate information of the position of the upper hook 11 in real time, and transmitting the three-dimensional coordinate information to the main controller 30; the upper cylinder one 12a and the upper cylinder two 12b are both provided with displacement sensors, which can monitor the extension distance of the cylinder in real time, and transmit the monitored data to the main controller 30.

[0023] The lower hanging point module 20 comprises a front beam frame 21, a rear beam frame 22, a left lower hook 23, a right lower hook 24, both ends of the front beam frame 21 are respectively connected with telescopic connecting arms 25, the rear ends of the two telescopic connecting arms 25 are respectively connected to the left and right ends of the front beam frame 21, the front ends of the telescopic connecting arms 25 are connected to the upper of the tractor rear axle 40, and a lifting assembly 26 is arranged between the telescopic connecting arms 25 and the tractor rear axle 40; a rotary adjusting device 27 is arranged between the front beam frame 21 and the rear beam frame 22, an angle adjusting motor 28 is arranged on the front beam frame 21, the rear beam frame 22 is driven to rotate by the rotary adjusting device 27, and a rotary locking device 29 is arranged on the front beam frame 21 and used for locking or unlocking the rotary adjusting device 27; the left end and the right end of the rear beam frame 22 are respectively transversely and slidably provided with a left telescopic hanging arm 210 and a right telescopic hanging arm 211, the left lower hook 23 is arranged at the lower part of the left end of the left telescopic hanging arm 210, a left lower oil cylinder 212 is arranged between the left telescopic hanging arm 210 and the rear beam frame 22, both ends of the left lower oil cylinder 212 are respectively connected to the left telescopic hanging arm 210 and the rear beam frame 22, and the left lower oil cylinder 212 is used for driving the left telescopic hanging arm 210 to drive the left lower hook 23 to move in the left-right direction, the right lower hook 24 is arranged at the lower part of the right end of the right telescopic hanging arm 211, a right lower oil cylinder 213 is arranged between the right telescopic hanging arm 211 and the rear beam frame 22, both ends of the right lower oil cylinder 213 are respectively connected to the right telescopic hanging arm 211 and the rear beam frame 22, and the right lower oil cylinder 213 is used for driving the right telescopic hanging arm 211 to drive the right lower hook 24 to move in the left-right direction, and a power docking device 214 connected with the tractor rear output end is mounted on the middle part of the rear beam frame 22, and the power docking device 214 is a component for power connection between the tractor rear output end and the power input end of the farm implement B.

[0024] The main controller 30 is arranged on the rear beam frame 22, displacement sensors are arranged in the left lower oil cylinder 212 and the right lower oil cylinder 213, the extension distances of the oil cylinders can be monitored in real time, and the monitored data is transmitted to the main controller 30.

[0025] Referring to Figure 3 and Figure 4 , the telescopic connecting arm 25 comprises a supporting arm 25a and an extension arm 25b slidably sleeved in the supporting arm 25a, positioning holes are arranged between the supporting arm 25a and the extension arm 25b, at least two positioning holes are connected by bolts or pins, the rear end of the supporting arm 25a is fixed to the front beam frame 21 by a U-shaped bolt, a connecting fulcrum plate 25c is further arranged at the top of the rear end of the supporting arm 25a, the front end of the extension arm 25b is provided with an extension arm 25b connecting hole, and the extension arm connecting hole 25d is hinged to the tractor rear axle 40.

[0026] The lifting assembly 26 can swing the telescopic connecting arm 25 up and down, so as to adjust the height position of the lower hanging point module 20. The lifting assembly 26 comprises an adjusting rod 26a, a lifting arm 26b and a lifting hydraulic cylinder 26c, the bottom end of the adjusting rod 26a is hinged to the connecting fulcrum plate 25c, the top end of the adjusting rod 26a is hinged to the rear end of the lifting arm 26b, the front end of the lifting arm 26b is hinged to the tractor rear axle 40, the top end of the lifting hydraulic cylinder 26c is hinged to the middle part of the lifting arm 26b, and the bottom end of the lifting hydraulic cylinder 26c is hinged to the tractor rear axle 40. When the lifting hydraulic cylinder 26c is elongated, the lifting arm 26b swings upward, the telescopic connecting arm 25 is pulled upward by the adjusting rod 26a, and the height of the left lower hook 23, the right lower hook 24 and the power docking device 214 is increased; when the lifting hydraulic cylinder 26c is retracted, the lifting arm 26b swings downward, the telescopic connecting arm 25 is pushed downward by the adjusting rod 26a, and the height of the left lower hook 23, the right lower hook 24 and the power docking device 214 is decreased.

[0027] Referring to Figures 3 to 5 , the rotation adjusting device 27 comprises a front beam connecting frame 27a fixed to the front beam frame 21 and two rear beam connecting frames 27b fixed to the rear beam frame 22, the two rear beam connecting frames 27b are clamped between the front beam connecting frame 27a and connected through a rotating shaft, a driven gear 27c is fixed on the rear beam connecting frame 27b at the axis of the rotating shaft, the body of the angle adjusting motor 28 is fixed to the front beam frame 21, a driving gear 27d is installed on the output end of the angle adjusting motor 28, the driving gear 27d and the driven gear 27c are driven through an intermediate gear 27e, the intermediate gear 27e is rotationally connected to the front beam frame 21, and the rotation locking device 29 cooperates with the intermediate gear 27e to lock or unlock. When the rotation locking device 29 is in the locking state, the intermediate gear 27e is locked at this time, the angle adjusting motor 28 cannot rotate the intermediate gear 27e, so the rear beam frame 22 is fixed and no longer rotates relative to the front beam frame 21. When the rotation locking device 29 is in the unlocking state, the intermediate gear 27e is released at this time, the angle adjusting motor 28 can rotate the intermediate gear 27e through the driving gear 27d, so that the rear beam connecting frame 27b rotates around the rotating shaft through the driven gear 27c, so that the rear beam frame 22 rotates relative to the front beam frame 21, and the state after rotation is shown in Figure 6 .

[0028] Referring to Figure 7The rotating locking device 29 comprises a fixed block 29a fixed on the front beam frame 21, a lock tongue 29b slidingly arranged in the fixed block 29a, a locking tooth 29c arranged at the inner end of the lock tongue 29b, the locking tooth 29c being in toothed engagement with the intermediate gear 27e, a locking tension spring 29d arranged between the outer end of the lock tongue 29b and the fixed block 29a, one end of the locking tension spring 29d being connected to the lock tongue 29b and the other end being connected to the fixed block 29a, and a lock tongue 29b rack arranged at the outer end of the lock tongue 29b. An unlocking motor 29e is fixed on the front beam frame 21, and an unlocking gear 29f is arranged at the output end of the unlocking motor 29e and is in engagement with the lock tongue 29b rack. The lock tongue 29b is pulled by the locking tension spring 29d to apply force in the direction of the intermediate gear 27e, so that the locking tooth 29c is in clamping engagement with the intermediate gear 27e, thereby limiting the rotation of the intermediate gear 27e and achieving the purpose of locking. The locked state is shown in Figure 7 When unlocking is required, the unlocking motor 29e is energized to drive the unlocking gear 29f to rotate, so that the lock tongue 29b is moved away from the intermediate gear 27e through the lock tongue 29b rack, and the locking tooth 29c is separated from the intermediate gear 27e, thereby achieving the purpose of unlocking.

[0029] Referring to Figures 8 to 10 The power docking device 214 comprises a mounting shell 214a fixed on the rear beam frame 22, the mounting shell 214a serving as a mounting base, a bearing seat 214b slidingly mounted in the mounting shell 214a, four long guide holes being formed in the mounting shell 214a in the embodiment, and guide shafts 214c slidingly arranged in the guide holes, the front segment of each guide shaft 214c sliding in the guide hole, and the rear end of each guide shaft 214c being threadedly connected with the bearing seat 214b, so that the bearing seat 214b can slide in the mounting shell 214a in the axial direction under the guidance of the guide shaft 214c; a spline shaft sleeve 214d is mounted in the bearing seat 214b through a bearing, the front end of the spline shaft sleeve 214d is connected with a shaft coupling 214e through a locking screw, the shaft coupling 214e is connected with the rear output shaft of the tractor through an extension cylinder 214f, the rear end of the spline shaft sleeve 214d is machined with an internal spline and is provided with a chamfer, and the farm implement B is provided with a spline shaft matched with the spline shaft sleeve 214d.

[0030] In this embodiment, two bearings are arranged in the bearing seat 214b, and a bearing limiting sleeve is arranged between the two bearings. The bearing limiting sleeve comprises an inner limiting sleeve and an outer limiting sleeve. The inner limiting sleeve is arranged on the inner ring of the bearing, and the outer limiting sleeve is arranged on the outer ring of the bearing. The rear end of the bearing seat 214b is provided with a sealing groove, and a sealing ring is arranged in the sealing groove to prevent dust. The end cover of the bearing seat 214b is provided with a stopper which is arranged on the outer ring of the bearing to prevent the bearing from sliding. The spline shaft sleeve 214d is a stepped shaft, and a limiting step is arranged on the spline shaft sleeve 214d to limit the bearing. A bearing locking nut is arranged on the limiting step to lock the bearing.

[0031] The mounting shell 214a is fixedly provided with an elongated plate 214g which extends along the axial direction of the spline shaft sleeve 214d. A power docking oil cylinder 214h is arranged on the elongated plate 214g. The power docking oil cylinder 214h is used to drive the bearing seat 214b to slide. The piston rod end of the oil cylinder is fixedly connected with the bearing seat 214b. The power docking oil cylinder 214h drives the bearing seat 214b to slide, so that the spline shaft sleeve 214d is combined with or separated from the spline shaft of the agricultural implement B. A displacement sensor is arranged in the power docking oil cylinder 214h. The displacement sensor can monitor the extension distance of the oil cylinder in real time, and transmit the monitored data to the main controller 30.

[0032] After the front and rear hanging parts are roughly positioned, the axis of the spline shaft is roughly coincided with the axis of the spline shaft sleeve 214d. In this state, the movement of the power docking oil cylinder 214h is controlled by controlling the hydraulic valve. When the power docking oil cylinder 214h is extended, the bearing seat 214b is pushed to move, so as to indirectly drive the spline shaft sleeve 214d to extend. Under the action of the chamfer guide, the spline shaft is smoothly inserted into the spline shaft sleeve 214d. When the power docking oil cylinder 214h moves to the limit position, the docking is completed, and the oil cylinder is self-locked to prevent the spline shaft sleeve 214d from falling off during the movement. The torque transmission can be realized by the cooperation of the spline shaft and the spline shaft sleeve 214d. The power docking is fully automatic, and manual intervention is not required. The connection efficiency can be greatly improved, and the torque transmission is stable and reliable. After the docking is completed, the axes of the spline shaft and the spline shaft sleeve 214d are coincided. At this time, only the side surfaces of the splines of the spline shaft and the spline shaft sleeve 214d are in contact. When the spline shaft rotates, it is almost not affected by any radial force. Without the action of the radial force, the device will not vibrate and rub, so as to prolong the service life of the spline.

[0033] The structures of the left lower hook 23, the right lower hook 24 and the upper hook 11 are basically the same, only the positions and directions of installation are different, wherein the hooking openings of the left lower hook 23 and the right lower hook 24 are upward, and the hooking is performed from below to above, while the hooking opening of the upper hook 11 is downward, and the hooking is performed from above to below. Since the structures and principles are basically the same, only the left hook is taken as an example to be described in combination with the drawings.

[0034] Referring to Figure 11 and Figure 12 , the left lower hook 23 comprises a first hook seat 23a fixed to the left end of the left telescopic hooking arm 210, a first hooking pin hole 23b and a first hooking opening communicated with the first hooking pin hole 23b are arranged in the first hook seat 23a, the first hooking opening is upward, a first sliding block guide groove corresponding to the first hooking opening is arranged in the first hook seat 23a, a first hooking sliding block 23c is slidingly installed in the first sliding block guide groove, a first guide arc surface bending towards one side of the first hooking pin hole 23b is arranged at the opening end of the first hooking sliding block 23c, a first locking tension spring 23d is arranged between the tail end of the first hooking sliding block 23c and the first hook seat 23a, a first locking positioning member is arranged between the first hooking sliding block 23c and the first hook seat 23a, and a first electric control unlocking device overcoming the first locking tension spring 23d is further arranged on the first hooking sliding block 23c; the first electric control unlocking device comprises a first unlocking motor 23e arranged on the first hook seat 23a, a first unlocking gear 23f is installed at the output end of the first unlocking motor 23e, a first sliding block rack 23g is arranged on the surface of the first hooking sliding block 23c away from the first hooking pin hole 23b, and the first unlocking gear 23f and the first sliding block rack 23g are in transmission cooperation. When the left lower hook 23 approaches the pin shaft of the lower hooking point from below to above, the first hooking sliding block 23c contacts the pin shaft, the pin shaft pushes the first hooking sliding block 23c downward due to the continuous upward movement of the left lower hook 23, the first hooking sliding block 23c slides downward relative to the first hook seat 23a to open the first hooking opening by overcoming the first locking tension spring 23d, the pin shaft enters into the first hooking pin hole 23b along the first guide arc surface with the continuous upward movement of the left lower hook 23, and the first hooking sliding block 23c is no longer pressed by the pin shaft, so as to be reset and locked under the action of the first locking tension spring 23d; when unlocking is needed, the first unlocking motor 23e is powered on to drive the first unlocking gear 23f to rotate, the first sliding block rack 23g overcomes the elastic force of the first locking tension spring 23d to open the first hooking sliding block 23c downward, and then the left lower hook 23 is moved to make the pin shaft leave the first hooking opening.

[0035] The right lower hook 24 comprises a second hook base, a second hooking pin hole and a second hooking opening communicated with the second hooking pin hole are arranged in the second hook base, a second sliding block guide groove is arranged in the second hook base corresponding to the second hooking opening, a second hooking sliding block is slidingly installed in the second sliding block guide groove, a second guide arc surface curved towards one side of the second hooking pin hole is arranged at the opening end of the second hooking sliding block, a second locking tension spring is arranged between the tail end of the second hooking sliding block and the second hook base, a second locking positioning piece is arranged between the second hooking sliding block and the second hook base, and a second electric control unlocking device overcoming the second locking tension spring is further arranged on the second hooking sliding block; the second electric control unlocking device comprises a second unlocking motor arranged on the second hook base, a second unlocking gear is installed at the output end of the second unlocking motor, a second sliding block rack is arranged on the surface of the second hooking sliding block away from the second hooking pin hole, and the second unlocking gear and the second sliding block rack are drivingly matched. The working principle of the right lower hook 24 is the same as that of the left lower hook 23, and details are not repeated here.

[0036] The upper hook 11 comprises a third hook base, a third hooking pin hole and a third hooking opening communicated with the third hooking pin hole are arranged in the third hook base, a third sliding block guide groove is arranged in the third hook base corresponding to the third hooking opening, a third hooking sliding block is slidingly installed in the third sliding block guide groove, a third guide arc surface curved towards one side of the third hooking pin hole is arranged at the opening end of the third hooking sliding block, a third locking tension spring is arranged between the tail end of the third hooking sliding block and the third hook base, a third locking positioning piece is arranged between the third hooking sliding block and the third hook base, and a third electric control unlocking device overcoming the third locking tension spring is further arranged on the third hooking sliding block; the third electric control unlocking device comprises a third unlocking motor arranged on the third hook base, a third unlocking gear is installed at the output end of the third unlocking motor, a third sliding block rack is arranged on the surface of the third hooking sliding block away from the third hooking pin hole, and the third unlocking gear and the third sliding block rack are drivingly matched. The working principle of the upper hook 11 is the same as that of the left lower hook 23, and details are not repeated here.

[0037] Referring to Figure 13For the above-mentioned hanging cooperation, the agricultural tool B is provided with three hanging points arranged in an isosceles triangle, namely an upper hanging point 50, a left lower hanging point 60 and a right lower hanging point 70, and a spline shaft 80 is arranged at the middle of the three hanging points. A secondary controller 90 is further arranged on the agricultural tool B, which is used to record the basic information of the agricultural tool B, such as the name, weight, position information, interface orientation information, interface position information, ground clearance information and input shaft information. By respectively installing a positioner at the three hanging points, the three-dimensional coordinate information of the three hanging points can be detected, and the three-dimensional coordinate information is transmitted to the secondary controller 90, so that the relative distance between the hanging points can be obtained. Herein, the three-dimensional coordinate information and the relative distance are taken as the interface position information. Of course, the relative distance between the interfaces can also be pre-stored in the secondary controller 90 as the interface position information, and the relative positions of the interfaces and the hooks are obtained by using a radar at the rear end of the hanger A, so as to obtain the three-dimensional coordinate information of the interfaces.

[0038] Referring to Figure 14 A three-point suspension hanging method for automatic hanging of an agricultural tool B, comprising the following steps: Preparation stage before hanging: connecting the above-mentioned hanger A to the tractor rear axle 40 and connecting the hanger A with the power end of the tractor, and placing a plurality of different types or different models of agricultural tools B on the ground to wait for being hung.

[0039] S1, reversing adjustment according to the orientation of the agricultural tool B: after the driver selects the agricultural tool B to be hung in the cab, the main controller 30 of the hanger A at the rear of the tractor communicates with the secondary controller 90 of the selected agricultural tool B, the main controller 30 obtains the position information and the interface orientation information of the agricultural tool B, the main controller 30 positions the agricultural tool B according to the position information and judges the orientation of the interface of the agricultural tool B according to the interface orientation information, and displays the position and direction of the agricultural tool in the display screen of the cab. The driver controls the tractor to reverse towards the agricultural tool interface, and the initial state is shown in Figure 16 During this process, the tractor reverses manually according to the obtained data. Since the subsequent special method can better complete the hanging, the accuracy requirement of the tractor reversing is not high, and it can be considered as a rough positioning.

[0040] S2, adjusting the lower hooks according to the interface information: during the reversing process, the main controller 30 obtains the interface position information and the ground clearance information of the implement B, the main controller 30 obtains the distance between the left lower hook 60 and the right lower hook 70 of the implement B according to the interface position information, and defines it as L, and then obtains the distance between the left lower hook 23 and the right lower hook 24 of the hitch A according to the left hook positioner and the right hook positioner, and defines it as L1, and then judges whether L1 is equal to L, when L1≠L, the left lower oil cylinder 212 and the right lower oil cylinder 213 are controlled to synchronously stretch and retract along the left-right direction for adjustment until L1=L, and then stop; during the stretching and retracting of the oil cylinder, the upper oil cylinder assembly 12 is controlled to swing the upper hook 11 upward to avoid the implement B to avoid affecting the hooking of the left lower hook 23 and the right lower hook 24, see Figure 15 (a) the front and back changes of the left and right hooks; The main controller 30 obtains the height of the left lower hook 60 and the right lower hook 70 of the implement B relative to the ground according to the ground clearance information, and defines it as H, and then obtains the height of the left lower hook 23 and the right lower hook 24 of the hitch A relative to the ground according to the left hook positioner and the right hook positioner, and defines it as H1, and then judges the size of H1 and H, when H1+10cm≥H, the lifting assembly 26 is controlled to act to lower the left lower hook 23 and the right lower hook 24 at the same time until H1+10cm<H, and then stop, and the state after height adjustment is shown in Figure 17 ; During the reversing process, the main controller 30 and the secondary controller 90 communicate in real time, judge the relative position of the two lower hooks of the hitch A and the two lower hook points of the implement B, when one of the lower hooks of the hitch A moves to the lower area between the two lower hook points of the implement B, stop reversing, and complete the rough positioning of the tractor. During the rough positioning process, the tractor always maintains the reversing state, and the width adjustment between the two lower hooks and the height adjustment of the two lower hooks are completed at the same time, and this process only needs one-time reversing and stopping, and does not need to repeatedly adjust the vehicle.

[0041] S3, judging whether parallel, adjusting angle: in the first parking state, before angle adjustment, rear beam frame 22 is in initial state parallel with front beam frame 21, main controller 30 gets the line between two lower hanging points according to the interface position information of agricultural implement B, defines it as AB, gets the line between two lower hooks according to left hook positioner and right hook positioner, defines it as AB1, then judges whether AB and AB1 are parallel, when AB and AB1 are not parallel, main controller 30 calculates the deviation angle and deviation direction between AB and AB1, converts the deviation angle into the rotation number of angle adjusting motor 28, controls the power-on unlocking of rotation locking device 29, then angle adjusting motor 28 rotates quantitatively according to the rotation number and direction, drives the whole rotation of rear beam frame 22 and two lower hooks installed on rear beam frame 22, stops until AB and AB1 are parallel, completes angle adjustment, see Figure 15 (b) the front and back changes of left and right hooks. In angle adjustment, tractor is kept in parking state, at this time, position determination of hanging point and hook is more accurate, only adjust rear beam frame 22 to make two lower hooks parallel with two lower hanging points. In this embodiment, when tractor reverses to approach agricultural implement B, tractor head may face the left front of agricultural implement B, may also face the right front of agricultural implement B, when agricultural implement B faces the left front of agricultural implement B, rear beam frame 22 needs to rotate clockwise for adjustment, when agricultural implement B faces the right front of agricultural implement B, rear beam frame 22 needs to rotate counterclockwise for adjustment, therefore, first determine the rotation direction of rear beam frame 22, then rotate clockwise or counterclockwise combined with deviation angle.

[0042] S4, continue reversing, lower hook adjustment and hitching: tractor continues to reverse, drives two lower hooks of hitching implement A to move towards agricultural implement B, stops reversing when moving to the lower of two lower hanging points of agricultural implement B; main controller 30 gets the distance of left lower hook 23 and left lower hanging point 60 in left and right direction according to the position of left lower hook 23 and left lower hanging point 60, gets the distance of right lower hook 24 and right lower hanging point 70 in left and right direction according to the position of right lower hook 24 and right lower hanging point 70, controls the action of left lower oil cylinder 212 and right lower oil cylinder 213 respectively according to the obtained distance, left lower oil cylinder 212 and right lower oil cylinder 213 act synchronously, one extends and the other retracts, the extension amount and the retraction amount are equal, when left lower hook 23 is located directly below left lower hanging point 60 and right lower hook 24 is located directly below right lower hanging point 70, two oil cylinders stop, see Figure 15 (c) the front and back changes of left and right hooks, the state after adjustment simultaneously, see Figure 17Then, the main controller 30 controls the lifting assembly 26 to act to drive the left lower hook 23 and the right lower hook 24 to be lifted upward at the same time, and in the lifting process, the pins at the left lower hanging point 60 and the right lower hanging point 70 of the farm tool B will press the left lower hook 23 and the right lower hook 24 to be opened and locked after being hung, so as to complete the automatic hanging of the left lower hanging point 60 and the left lower hook 23 and the automatic hanging of the right lower hanging point 70 and the right lower hook 24. The state after the hanging is shown in FIG. 6. Figure 19 At this stage, the tractor is reversed and stopped again to meet the hanging of the lower hanging point.

[0043] S5, the upper hook 11 is adjusted and hung: the main controller 30 controls the upper oil cylinder assembly to act according to the relative position of the upper hanging point 50 of the farm tool B and the upper hook 11 of the hanging tool A, drives the upper hook 11 to move from top to bottom to approach the upper hanging point 50, the pins at the upper hanging point 50 will press the upper hook 11 to be opened and locked after being hung, so as to complete the automatic hanging of the upper hanging point 50 and the upper hook 11. The state after the hanging is shown in FIG. 6. Figure 20 At this stage, the tractor remains stationary.

[0044] S6, the initial state is restored, the shaft power is adjusted and hung: after the hanging of the three hanging points is completed, the main controller 30 controls the lifting assembly 26 and the upper oil cylinder assembly to act to drive the farm tool B to leave the ground; then, the angle adjusting motor 28 is controlled to act, the angle adjusting motor 28 is reversely rotated according to the number of rotation circles, drives the rear beam frame 22 and the whole farm tool B to be reversely rotated to restore the initial state, as shown in FIG. 6. Figure 15 (d) the front and back changes of the left and right hooks, and then the rotation locking device 29 is locked by being powered off; at this stage, the tractor remains stationary, but the whole farm tool B can be changed in angle by the angle adjusting motor 28, so as to adapt to the position of the tractor. In the rotation process of the farm tool B, the upper oil cylinder assembly 12, the left lower oil cylinder 212 and the right lower oil cylinder 213 are synchronously actuated to be adaptively adjusted, and finally the left lower oil cylinder 212 and the right lower oil cylinder 213 have the same extension amount, the plane where the upper hook 11, the left lower hook 23 and the right lower hook 24 are located is perpendicular to the ground and then stops; then, the main controller 30 controls the power docking oil cylinder 214h to be extended to drive the spline shaft sleeve 214d to move towards the farm tool B, the spline shaft sleeve 214d is inserted outside the spline shaft 80 of the farm tool B and is locked, the power of the tractor is transmitted to the farm tool B through the shaft coupling 214e, the spline shaft sleeve 214d and the spline shaft 80, and the power docking between the hanging tool A and the farm tool B is completed. The state after the power docking is shown in FIG. 6. Figure 21 .

[0045] S7, hanging separation: the main controller 30 first controls the power docking oil cylinder 214h to retract, disconnects the spline shaft sleeve 214d from the spline shaft 80, then controls the lifting assembly 26 and the upper oil cylinder assembly 12 to place the implement B on the ground, then controls the upper hook 11, the left lower hook 23 and the right lower hook 24 to be unlocked, then drives the upper hook 11 to move upward and disengage from the upper hanging point 50 through the action of the upper oil cylinder assembly 12, and then drives the left lower hook 23 and the right lower hook 24 to move downward and disengage from the left lower hanging point 60 and the right lower hanging point 70 through the action of the lifting assembly 26, and the tractor advances to achieve complete separation of the implement B from the hitch A.

[0046] The hitch of the present application can adjust the positions and distances of the two lower hooks and the upper hook, and can adapt to various sizes of three-point suspension implements. Meanwhile, the power docking device can be telescopic and can adapt to implements with power input. The hitch can rotate an angle, which can be adjusted within a certain range even if the driver is not skilled at reversing, and the hitch does not need to be repeatedly reversed to find the connection position and angle as in the traditional hitch. During the reversing process of the tractor, only two stops are required. During the first stop, the two key actions are angle adjustment and hook translation. The direction of the hitch is directly changed through angle adjustment to adapt to the angle of the implement, and then the positions of the hooks in the left-right direction relative to the two lower hanging points are changed through synchronous translation of the left and right lower hooks, so as to achieve the effect that the two lower hooks are parallel to the two lower hanging points and consistent in the left-right direction. During the adjustment process, the tractor is kept in a stopped state, and the effect that the tractor is not moving but can be completely adapted to the lower hanging points is achieved. The second stop is the final stop, which is used for hitching and power docking, so the second stop is the same as the final stop in the traditional hitching method. During the first stop, the tractor is roughly positioned, and the direction and position of the tractor do not need to be very strict. The angle is adjusted and the hook is translated based on the rough positioning to achieve accurate positioning, so the requirements for the reversing of the tractor and the driver are reduced, and the hitching difficulty is greatly reduced. Compared with the traditional hitching method, the hitching method of the present application only requires one intermediate stop before the final stop during the hitching process of the tractor, and the angle is adjusted during the intermediate stop while the tractor is kept in a stopped state. After the angle is adjusted, the tractor continues to reverse, and the tractor never advances to adjust the angle during the entire reversing process. In the prior art, the angle of the tractor needs to be repeatedly adjusted to adapt to the angle of the implement, so the tractor repeatedly advances and reverses until the hitch and the implement are parallel. This adjustment method has large errors, low efficiency, and is time-consuming and labor-intensive. However, the prior art can only use this adjustment method, but the present application provides a new structure combination method to achieve fast hitching, which can greatly reduce the hitching time, does not require additional personnel intervention during the hitching process, and can be completed by one driver, which can reduce labor and improve efficiency.

[0047] The foregoing is considered as illustrative only of the principles of the application. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the application to the exact construction and practice described. Accordingly, all such variations and modifications are intended to be included within the scope of the application as defined in the following claims and the equivalents thereof.

Claims

1. A three-point suspension method for automatic attachment of agricultural implements, characterized in that, Includes the following steps: S1. After the driver selects the implement to be attached, the main controller of the tractor's rear attachment will communicate with the secondary controller of the selected implement. The main controller obtains the implement's position information and interface orientation information. The main controller locates the implement's position based on the position information and determines the orientation of the implement's interface based on the interface orientation information. The position and direction of the implement are displayed on the cab display screen. The driver then controls the tractor to reverse towards the implement interface. S2. During the reversing process, the main controller acquires the interface position information and ground clearance information of the implement. Based on the interface position information, the main controller obtains the distance between the lower left and lower right hook points of the implement and defines it as L. At the same time, based on the left and right hook positioners, the main controller obtains the distance between the lower left and lower right hooks of the implement and defines it as L1. Then, it determines whether L1 is equal to L. When L1 ≠ L, it controls the lower left and lower right cylinders to extend and retract synchronously in the left and right directions until L1 = L and then stops. During the extension and retraction of the cylinders, it controls the upper cylinder assembly to drive the upper hook to swing upward away from the implement to avoid it. The main controller then obtains the height of the lower left and lower right hooks of the implement relative to the ground based on the ground clearance information, and defines it as H. At the same time, it obtains the height of the lower left and lower right hooks of the implement relative to the ground based on the left and right hook positioners, and defines it as H1. Then, it judges the size of H1 and H. When H1 + 10cm ≥ H, it controls the lifting component to move and drive the lower left and lower right hooks to descend simultaneously until H1 + 10cm < H. During the reversing process, the main controller and the secondary controller communicate data in real time to judge the relative position of the two lower hooks of the implement and the two lower hooks of the implement. When one of the lower hooks of the implement moves to the area below the two lower hooks of the implement, the reversing stops. S3. The main controller then obtains the connection between the two lower hook points based on the interface position information of the implement and defines it as AB. Based on the left hook locator and the right hook locator, it obtains the connection between the two lower hooks and positions it as AB1. Then it determines whether AB and AB1 are parallel. When AB and AB1 are not parallel, the main controller calculates the deviation angle and deviation direction between AB and AB1 and converts the deviation angle into the number of rotations of the angle adjustment motor. At the same time, it controls the rotation locking device to be energized and unlocked. Then the angle adjustment motor rotates quantitatively according to the number of rotations and direction, driving the rear beam frame and the two lower hooks installed on the rear beam frame to rotate as a whole until AB and AB1 are parallel and then it stops. S4. The tractor continues to reverse, causing the two lower hooks of the attachment to move towards the implement. When they move to below the two lower hook points of the implement, the tractor stops reversing. The main controller obtains the distance between the lower left hook and the lower left hook point in the left-right direction based on the position of the lower left hook and the lower left hook point. It also obtains the distance between the lower right hook and the lower right hook point in the left-right direction based on the position of the lower right hook and the lower right hook point. Based on the obtained distances, the lower left and lower right cylinders are controlled to move. The lower left and lower right cylinders move synchronously, one extending and the other retracting. The extension amount and the retraction amount are equal. When the lower left hook is directly below the lower left hook point and the lower right hook is directly below the lower right hook point, the two cylinders stop. The main controller controls the lifting component to lift the lower left and lower right hooks simultaneously. During the lifting process, the pins at the lower left and lower right hooks of the implement will press the lower left hook, open the lower right hook, and lock it after engagement, thus completing the automatic engagement of the lower left hook and the lower right hook. S5. The main controller controls the upper cylinder assembly to move according to the relative position of the upper hook of the implement and the upper hook of the attachment. The upper hook moves from top to bottom and approaches the upper hook. The pin at the upper hook will press the upper hook to open, engage and lock, thus completing the automatic engagement of the upper hook and the upper hook. S6. After all three attachment points are engaged, the main controller controls the lifting assembly and the upper hydraulic cylinder assembly to lift the implement off the ground. Then, the angle adjustment motor is controlled to rotate in the opposite direction according to the number of rotations, which drives the rear beam frame and the implement as a whole to rotate in the opposite direction to restore the initial state. Then, the rotation locking device is de-energized and locked. During the rotation of the implement, the upper cylinder assembly, lower left cylinder, and lower right cylinder move synchronously to make adaptive adjustments. Finally, the lower left cylinder and lower right cylinder extend by the same amount, and the plane containing the upper hook, lower left hook, and lower right hook stops when it is perpendicular to the ground. Then, the main controller controls the power docking cylinder to extend and drive the splined bushing to move toward the implement. The splined bushing is inserted into and locked onto the splined shaft of the implement. The tractor's power is transmitted to the implement through the coupling, splined bushing, and splined shaft, completing the power docking between the attachment and the implement. S7. The main controller first controls the power docking cylinder to retract, disconnecting the spline bushing from the spline shaft. Then, it controls the lifting assembly and the upper cylinder assembly to place the implement on the ground. Next, it controls the upper hook, lower left hook, and lower right hook to unlock electrically. Then, the upper cylinder assembly moves the upper hook upward and disengages from the upper attachment point. Then, the lifting assembly moves the lower left hook and lower right hook downward and disengages from the lower left and lower right attachment points, allowing the tractor to move forward and achieving complete separation of the implement from the attachment.

2. The three-point suspension method for automatic attachment of agricultural implements as described in claim 1, characterized in that, The mounting bracket includes an upper mounting point module and a lower mounting point module. The upper attachment point module includes an upper hook and an upper cylinder assembly. The front end of the upper cylinder assembly is connected to the rear axle of the tractor, and the upper hook is located at the rear end of the upper cylinder assembly. The lower attachment point module includes a front beam frame, a rear beam frame, a left lower hook, and a right lower hook. Telescopic connecting arms are connected to both ends of the front beam frame, and the ends of the telescopic connecting arms are connected to the tractor's rear axle. A lifting assembly is provided between the telescopic connecting arms and the tractor's rear axle. A rotation adjustment device is provided between the front beam frame and the rear beam frame. An angle adjustment motor is installed on the front beam frame, which drives the rear beam frame to rotate via the rotation adjustment device. A rotation locking device is provided on the front beam frame to lock or unlock the rotation adjustment device. A left telescopic attachment arm and a right telescopic attachment arm are laterally slidable at the left and right ends of the rear beam frame, respectively. The left lower hook is located at the lower left end of the left telescopic attachment arm, and a left lower hydraulic cylinder is provided between the left telescopic attachment arm and the rear beam frame. The right lower hook is located at the lower right end of the right telescopic attachment arm, and a right lower hydraulic cylinder is provided between the right telescopic attachment arm and the rear beam frame. A power docking device connected to the tractor's rear output end is installed on the middle of the rear beam frame.

3. The three-point suspension method for automatic attachment of agricultural implements as described in claim 2, characterized in that, The rotation adjustment device includes a front beam connecting frame fixed on the front beam frame and a rear beam connecting frame fixed on the rear beam frame. The rear beam connecting frame is clamped between the front beam connecting frames and the two are connected by a rotating shaft. A driven gear is fixed on the rear beam connecting frame at the axis of the rotating shaft. An active gear is installed at the output end of the angle adjustment motor. The active gear and the driven gear are driven by an intermediate gear. The rotation locking device cooperates with the intermediate gear to lock or unlock.

4. The three-point suspension method for automatic attachment of agricultural implements as described in claim 2, characterized in that, The rotary locking device includes a fixed block fixed to the front beam frame, a locking tongue slidably disposed within the fixed block, a locking tooth disposed at the inner end of the locking tongue, a locking tension spring disposed between the outer end of the locking tongue and the fixed block, a locking tongue rack disposed at the outer end of the locking tongue, an unlocking motor fixed on the front beam frame, an unlocking gear disposed at the output end of the unlocking motor, and the unlocking gear meshing with the locking tongue rack.

5. The three-point suspension method for automatic attachment of agricultural implements as described in claim 2, characterized in that, The power docking device includes a mounting housing fixed to the rear beam frame, a bearing seat slidably mounted inside the mounting housing, a splined bushing rotatably mounted inside the bearing seat, a coupling connected to the front end of the splined bushing, and an internal spline machined at the rear end of the splined bushing. A power docking cylinder is provided between the mounting housing and the bearing seat, and the power docking cylinder drives the bearing seat to extend and slide, thereby engaging or disengaging the splined bushing from the splined shaft.

6. The three-point suspension method for automatic attachment of agricultural implements as described in claim 2, characterized in that, The lower left hook includes a first hook base, which has a first hook pin hole and a first hook opening communicating with the first hook pin hole. A first slider guide groove is provided in the first hook base corresponding to the first hook opening. A first hook slider is slidably installed in the first slider guide groove. The open end of the first hook slider has a first guide arc surface curved towards the first hook pin hole. A first locking tension spring is provided between the tail end of the first hook slider and the first hook base. A first locking positioning member is provided between the first hook slider and the first hook base. The first hook slider also has a first electrically controlled unlocking device that overcomes the first locking tension spring. The first electrically controlled unlocking device includes a first unlocking motor mounted on the first hook base. A first unlocking gear is installed at the output end of the first unlocking motor. A first slider rack is provided on the surface of the first hook slider away from the first hook pin hole. The first unlocking gear and the first slider rack cooperate for transmission.

7. The three-point suspension method for automatic attachment of agricultural implements as described in claim 2, characterized in that, The lower right hook includes a second hook base, which has a second hook pin hole and a second hook opening communicating with the second hook pin hole. A second slider guide groove is provided in the second hook base corresponding to the second hook opening. A second hook slider is slidably installed in the second slider guide groove. The open end of the second hook slider has a second guide arc surface curved towards the second hook pin hole. A second locking spring is provided between the tail end of the second hook slider and the second hook base. A second locking positioning element is provided between the second hook slider and the second hook base. The second hook slider also has a second electrically controlled unlocking device that overcomes the second locking spring. The second electrically controlled unlocking device includes a second unlocking motor mounted on the second hook base. A second unlocking gear is installed at the output end of the second unlocking motor. A second slider rack is provided on the surface of the second hook slider away from the second hook pin hole. The second unlocking gear and the second slider rack cooperate for transmission.

8. The three-point suspension method for automatic attachment of agricultural implements as described in claim 2, characterized in that, The upper hook includes a third hook base, which has a third hook pin hole and a third hook opening communicating with the third hook pin hole. A third slider guide groove is provided in the third hook base corresponding to the third hook opening. A third hook slider is slidably installed in the third slider guide groove. The open end of the third hook slider has a third guide arc surface curved towards the third hook pin hole. A third locking spring is provided between the tail end of the third hook slider and the third hook base. A third locking positioning element is provided between the third hook slider and the third hook base. The third hook slider also has a third electrically controlled unlocking device that overcomes the third locking spring. The third electrically controlled unlocking device includes a third unlocking motor mounted on the third hook base. A third unlocking gear is installed at the output end of the third unlocking motor. A third slider rack is provided on the surface of the third hook slider away from the third hook pin hole. The third unlocking gear and the third slider rack cooperate for transmission.

9. The three-point suspension method for automatic attachment of agricultural implements as described in claim 2, characterized in that, The telescopic connecting arm includes a support arm and an extension arm that is slidably fitted inside the support arm. A positioning hole is provided between the support arm and the extension arm. The rear end of the support arm is fixed to the front beam frame. A connecting fulcrum plate is also provided at the top of the rear end of the support arm. An extension arm connecting hole is provided at the front end of the extension arm.

10. The three-point suspension method for automatic attachment of agricultural implements as described in claim 2, characterized in that, The upper cylinder assembly includes an upper cylinder one and an upper cylinder two. One end of the upper cylinder one is hinged to the rear axle of the tractor, and the upper hook is provided at the other end of the upper cylinder one. One end of the upper cylinder two is hinged to the rear axle of the tractor, and the other end of the upper cylinder two is hinged to the upper cylinder one.

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