Three-point suspension device lifting rod piece and agricultural machine

Abstract

According to the lifting rod piece of the three-point suspension device and the agricultural machine, the stability of the lifting rod piece is improved through the additionally-arranged positioning disc and the positioning assembly, the situation that the lengths of the upper adjusting rod and the lower adjusting rod are changed due to rotation of the adjusting pipe caused by mistaken touch or vibration and the like is avoided, the requirements of different working environments are met, and the working efficiency is improved. The lifting rod piece comprises an adjusting pipe, an upper adjusting rod and a lower adjusting rod, the upper adjusting rod and the lower adjusting rod are arranged at the two ends of the adjusting pipe respectively and are in threaded connection with the adjusting pipe, rod bodies of the upper adjusting rod and the lower adjusting rod are sleeved with positioning discs, and the positioning discs are provided with a plurality of positioning grooves. One or more connecting pipes are arranged on the outer walls of the two ends of the adjusting pipe respectively; a connecting rod is assembled in the connecting pipe, and the distance of the connecting rod extending out of the connecting pipe is adjustable so as to be matched with the screwing-out length of the upper adjusting rod or the lower adjusting rod; a positioning assembly is arranged on the upper portion of the connecting rod and inserted into the positioning groove so as to fix the screwing-out length of the upper adjusting rod or the lower adjusting rod.

Description

Technical Field

[0001] The utility model relates to the field of a three-point suspension device for a tractor, in particular to a lifting rod of a three-point suspension device and an agricultural machine. Background Art

[0002] The three-point suspension mechanism of the tractor is mainly composed of two lower pull rods and one upper pull rod. The traction force of the tractor is mainly transmitted by the two lower pull rods. The upper pull rod is mainly used to adjust the pitch of the agricultural implement in the longitudinal plane, and its length is adjustable.

[0003] The currently disclosed CN204681825U tractor three-point suspension lifting rod uses a hydraulic cylinder to replace the lead screw, which has a complex structure and is not easy to disassemble and repair. When adjusting the length, the large and small cylinders need to be filled with oil or sucked from the oil tank, and the stop valve is opened at the same time, which is complicated to operate.

[0004] The currently disclosed tractor three-point suspension device of CN206759977U has a traction rod connected between the lifting rod and the upper pull rod to limit the swing of the three-point suspension device and improve the structural stability and rigidity. However, the lifting rod limiting effect is not good, the tractor vibrates frequently during operation, and the nut locking device is easy to loosen.

[0005] In summary, the three-point suspension upper tie rod used in the current wheeled tractor has a simple structure, and it is inconvenient to adjust the length of the upper and lower adjustment rods by rotating the adjustment tube in conjunction with the thread. In addition, during use, it is easy to be accidentally touched or vibrated, resulting in looseness between the upper / lower adjustment rod and the adjustment tube, and the length between the upper / lower adjustment rod and the adjustment tube changes, affecting normal use. Utility Model Content

[0006] The purpose of the utility model is to provide a lifting rod of a three-point suspension device, which increases the stability of the lifting rod by adding a positioning plate and a positioning assembly, and avoids the situation in which the rotation of the adjustment tube causes the length of the upper adjustment rod and the lower adjustment rod to change due to accidental touch or vibration, so as to meet the requirements of different working environments.

[0007] Another object of the utility model is to provide an agricultural machine with a three-point suspension device, which can apply a new lifting rod to improve the stability of the equipment.

[0008] The embodiment of the utility model is achieved as follows:

[0009] A lifting rod member of a three-point suspension device, the lifting rod member includes an adjusting tube and an upper adjusting rod and a lower adjusting rod respectively arranged at two ends of the adjusting tube and threadedly connected to the adjusting tube, a positioning plate is sleeved on the rod body of the upper adjusting rod and the lower adjusting rod, and a plurality of positioning grooves are arranged on the positioning plate; one or more connecting tubes are respectively arranged on the outer walls of the two end tubes of the adjusting tube; a connecting rod is assembled in the connecting tube, and the distance that the connecting rod extends out of the connecting tube is adjustable to adapt to the screw-out length of the upper adjusting rod or the lower adjusting rod; a positioning assembly is arranged on the upper part of the connecting rod, and the positioning assembly is inserted into the positioning groove to fix the screw-out length of the upper adjusting rod or the lower adjusting rod.

[0010] In a preferred embodiment of the utility model, the above-mentioned positioning assembly includes: a pin frame, a positioning pin and a spring. The pin frame is a frame body with an open space in the middle, and the upper and lower ends of the pin frame are respectively provided with a first through hole and a second through hole that penetrate the open space up and down; the positioning pin passes through the first through hole, the open space and the second through hole, and the bottom shape and size of the positioning pin match the shape and size of the positioning groove; the spring is assembled in the open space and is sleeved on the positioning pin. When the positioning pin is pulled out of the positioning groove, the spring is compressed.

[0011] In a preferred embodiment of the present invention, the positioning assembly further comprises a pull ring, which is fixedly disposed on the upper portion of the positioning pin.

[0012] In a preferred embodiment of the utility model, a clamping block is further provided on the upper portion of the pin shaft frame. After the position of the locating pin is determined, the pull ring is clamped on the clamping block to fix the locating pin.

[0013] In a preferred embodiment of the present utility model, a connecting groove matching the edge structure of the positioning plate is further provided on the connecting rod.

[0014] In a preferred embodiment of the present invention, a handle ring is installed in the middle of the adjusting tube.

[0015] In a preferred embodiment of the present invention, the connecting pipe and the connecting rod are assembled in a detachable manner.

[0016] In a preferred embodiment of the present invention, the detachable connection comprises a snap connection or a threaded connection.

[0017] In a preferred embodiment of the present utility model, the connection pipe and the connection rod are assembled in a fixed connection, and the connection rod is a telescopic rod with a locking structure.

[0018] An agricultural machine with a three-point suspension device comprises any one of the above-mentioned three-point suspension device lifting rods.

[0019] The beneficial effects of the embodiments of the utility model are:

[0020] 1. A fixed connecting rod with adjustable extension length is provided at the connecting pipe, so that the length of the connecting rod can be adapted when the upper / lower adjusting rod is screwed out / in;

[0021] 2. A positioning plate is provided on the rod body of the upper / lower adjusting rod, and a positioning assembly is provided on the connecting rod, so that after the screw-out / screw-in length of the upper / lower adjusting rod is determined, the positioning assembly is used to lock the upper / lower adjusting rod, thereby preventing the adjustment tube from rotating due to accidental touch or vibration, causing the length of the upper adjusting rod and the lower adjusting rod to change. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 This is a schematic diagram of the lifting rod structure of the first embodiment of the utility model;

[0024] Figure 2 This is an enlarged structural diagram of the positioning assembly of the first embodiment of the utility model;

[0025] Figure 3 This is a schematic diagram of the positioning plate structure of the first embodiment of the utility model;

[0026] Figure 4 This is a schematic diagram of the lifting rod structure of the second embodiment of the utility model;

[0027] Icons: connecting fork 001; lifting rod 100; adjusting tube 110; connecting tube 111; handle ring 112; upper adjusting rod 120; lower adjusting rod 130; positioning plate 140; positioning groove 141; connecting rod 150; positioning assembly 160; pin bracket 161; open space 1611; positioning pin 162; spring 163; upper stopper 164; block 165; pull ring 166. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0031] In the description of the present utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the utility model product is usually placed when in use, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0032] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0033] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] First embodiment

[0035] The conventional three-point suspension device lifting rod 100 includes an adjustment tube 110 and an upper adjustment rod 120 and a lower adjustment rod 130 respectively disposed at both ends of the adjustment tube 110 and threadedly connected to the adjustment tube 110. During use, it is easy to be accidentally touched or vibrated, which may cause the upper / lower adjustment rod and the adjustment tube 110 to become loose, causing the length between the upper / lower adjustment rod and the adjustment tube 110 to change, thereby affecting use.

[0036] See also Figure 1-3 The present embodiment provides a three-point suspension device lifting rod 100, wherein a positioning plate 140 is sleeved on the rod body of the upper adjusting rod 120 and the lower adjusting rod 130, and a plurality of positioning grooves 141 are arranged on the positioning plate 140; one or more connecting tubes 111 are arranged on the outer walls of the two end tubes of the adjusting tube 110; a connecting rod 150 is assembled in the connecting tube 111, and the distance that the connecting rod 150 extends out of the connecting tube 111 is adjustable to adapt to the screw-out length of the upper adjusting rod 120 or the lower adjusting rod 130; a positioning assembly 160 is arranged on the upper part of the connecting rod 150, and the positioning assembly 160 is inserted into the positioning groove 141 to fix the screw-out length of the upper adjusting rod 120 or the lower adjusting rod 130.

[0037] In this embodiment, the positioning plate 140 is fixedly welded to the rod bodies of the upper adjusting rod 120 and the lower adjusting rod 130 , and the positioning plate 140 is located between the threaded rod and the connecting head, which is used to connect the connecting fork 001 .

[0038] Specifically, the shape of the positioning disk 140 is not limited. The positioning disk 140 in this embodiment is disc-shaped, and in other embodiments, it can be square, hexagonal or octagonal. The number and thickness of the positioning disk 140 are also not limited. It can be only one as in this embodiment, or the number or thickness of the positioning disk 140 can be adaptively increased according to the specifications of the agricultural machine. As long as the positioning disk 140 can meet the anti-rotation requirement of fixing the upper / lower adjustment rod through the positioning assembly 160, it belongs to the same concept of the present utility model.

[0039] In this embodiment, the positioning plate 140 is provided with a plurality of positioning grooves 141 arranged in a circular array, and the positioning grooves 141 are in the shape of cylindrical grooves. In other embodiments, the positioning grooves 141 may also be designed as positioning holes, or may be grooves or groove holes of other shapes such as rectangular grooves or star-shaped grooves. As long as the positioning grooves 141 can meet the requirements of inserting the positioning assembly 160 to fix the screw-out length of the upper adjustment rod 120 or the lower adjustment rod 130, and ensure that the upper adjustment rod 120 or the lower adjustment rod 130 no longer rotates, they belong to the same concept of the present utility model.

[0040] One or more connecting tubes 111 are arranged on the outer wall of the tube at both ends of the adjusting tube 110. In the present embodiment, a connecting tube 111 is arranged at each of the upper and lower ends. In other embodiments, in order to increase the limiting and fixing effect of the upper adjusting rod 120 or the lower adjusting rod 130, two, three or each upper connecting tube 111 may be arranged at the position corresponding to the positioning groove 141.

[0041] A connecting rod 150 is installed in the connecting tube 111 , and the distance that the connecting rod 150 extends out of the connecting tube 111 is adjustable to adapt to the screw-out length of the upper adjusting rod 120 or the lower adjusting rod 130 .

[0042] There are many ways to assemble the connecting pipe 111 and the connecting rod 150, which can be a fixed connection method or a detachable connection method.

[0043] For example, when the connection tube 111 and the connection rod 150 are fixedly connected. If welding is used, the connection rod 150 is designed as a telescopic rod with a locking structure, the fixed end of the telescopic rod is welded to the connection tube 111, and the telescopic end of the telescopic rod is provided with a positioning assembly 160, so as to achieve the purpose of adapting the screw-out length of the upper adjustment rod 120 or the lower adjustment rod 130. Even when welding is used, the outer wall of the adjustment tube 110 may not be provided with the connection tube 111, and the fixed end of the telescopic rod may be directly welded to the outer wall of the adjustment tube 110, so as to achieve the purpose of adapting the screw-out length of the upper adjustment rod 120 or the lower adjustment rod 130.

[0044] Considering factors such as convenient assembly and use effect, the assembly method of the connecting tube 111 and the connecting rod 150 is preferably a detachable connection method. There are also multiple options for detachable connection methods, such as a snap connection or a threaded connection. The snap connection can be a snap-fit ​​fixed design, a plug-in fixed design, or a pin-key fixed design, as long as the connecting tube 111 can fix the connecting rod 150 and the connecting rod 150 and the connecting tube 111 can be detached.

[0045] Furthermore, the connecting rod 150 may be a rod body of a fixed length, and by moving the fixed positions of the connecting rod 150 and the connecting tube 111, a structure in which the distance that the connecting rod 150 extends out of the connecting tube 111 is adjustable (such as the method disclosed in the second embodiment); or the connecting rod 150 may be a telescopic structure, and a structure in which the distance that the connecting rod 150 extends out of the connecting tube 111 is adjustable (such as the method disclosed in the first embodiment).

[0046] In this embodiment, the connecting rod 150 and the connecting tube 111 adopt one of the feasible solutions: the connecting rod 150 is a telescopic rod, and the bottom of the connecting rod 150 is a snap-fit ​​locking structure, that is, a slot for fixing the bottom of the connecting rod 150 is provided inside the connecting tube 111, and the connecting rod 150 and the connecting tube 111 are rectangular rods and rectangular tubes respectively. While fixing the connecting rod 150, the length of the connecting rod 150 can be adapted to the screw-out length of the upper adjustment rod 120 or the lower adjustment rod 130.

[0047] A telescopic rod is provided on the adjustment tube 110, and a positioning plate 140 is provided on the upper / lower adjustment rod, and the telescopic rod is slidably engaged with the positioning plate 140 and fixed by a positioning assembly, so that when the adjustment rod is rotated to adjust the length of the upper and lower adjustment rods, the upper and lower adjustment rods can drive the telescopic rod to extend and retract. After the adjustment is completed, the telescopic rod and the positioning plate 140 are fixed together under the action of the positioning assembly, so as to avoid the situation that the rotation of the adjustment tube causes the length of the upper and lower adjustment rods to change due to accidental touch or vibration.

[0048] A positioning assembly 160 is provided at the upper part of the connecting rod 150. The positioning assembly 160 can be fixedly and non-detachably connected to the connecting rod 150, or can be fixedly and detachably connected. The positioning assembly 160 is inserted into the positioning groove 141 to fix the screw-out length of the upper adjusting rod 120 or the lower adjusting rod 130. When the positioning assembly 160 is pulled out of the positioning groove 141, the upper adjusting rod 120 or the lower adjusting rod 130 is released so that the upper adjusting rod 120 or the lower adjusting rod 130 can rotate.

[0049] Specifically, the positioning assembly 160 includes a pin frame 161 , a positioning pin 162 penetrating the pin frame 161 , and a spring 163 sleeved on the positioning pin 162 and disposed in the pin frame 161 .

[0050] The pin frame 161 is a frame body with an open space 1611 in the middle. The pin frame 161 in the present embodiment is a rectangular frame structure. The pin frame 161 in other embodiments can be set to other shapes such as a trapezoid, and the shape of the open space 1611 in the middle is not limited. It can be a rectangular open space 1611 as in the present embodiment, or a cylindrical open space 1611, etc., which can achieve the purpose of assembling the locating pin 162 and the spring 163, and they all belong to the same concept.

[0051] The upper and lower ends of the pin shaft frame 161 are respectively provided with a first through hole and a second through hole that penetrates the open space 1611 up and down, for the positioning pin 162 to pass through; the positioning pin 162 passes through the first through hole, the open space 1611 and the second through hole, and the bottom shape and size of the positioning pin 162 match the shape and size of the positioning groove 141. During assembly, the positioning pin 162 is passed through the first through hole, the open space 1611 and the second through hole in sequence, and then the positioning pin 162 is inserted into the positioning groove 141 to fix the upper adjusting rod 120 or the lower adjusting rod 130 to prevent the upper adjusting rod 120 or the lower adjusting rod 130 from rotating.

[0052] The spring 163 is assembled in the open space 1611 and sleeved on the positioning pin 162 . When the positioning pin 162 is pulled out of the positioning slot 141 , the spring 163 is compressed. When the positioning pin 162 is inserted into the positioning slot 141 , the spring 163 is reset.

[0053] One end of the spring 163 can be welded to the positioning pin 162 , which can achieve the purpose that when the positioning pin 162 is pulled out of the positioning slot 141 , the spring 163 is compressed; when the positioning pin 162 is inserted into the positioning slot 141 , the spring 163 is reset.

[0054] In this embodiment, in order to prevent the spring 163 and the positioning pin 162 from being broken at the welding position and causing compression / reset failure during long-term and high-frequency use, an upper stopper 164 is further provided on the positioning pin 162 in this embodiment to reduce the need for fixed connection methods such as welding and increase the service life.

[0055] The locating pin 162 is also provided with a stop structure to prevent the locating pin 162 from passing through the first through hole position. There are many ways to implement it, such as increasing the diameter of the locating pin 162, or providing a pull ring 166 on the upper part of the locating pin 162 as in the present embodiment.

[0056] Furthermore, a block 165 is provided on the upper part of the pin shaft frame 161. The block 165 is a rectangular strip structure. When the locating pin 162 needs to be pulled up, the pull ring 166 can be clamped on the block 165 to fix the locating pin 162. When the locating pin 162 needs to be released, the pull ring 166 can be removed from the block 165. The block 165 can also be provided on both sides. One block 165 is used to fix the state of the locating pin 162 when it is inserted into the locating groove 141 to prevent the locating pin 162 from popping out of the locating shallow groove due to vibration, etc., and the other block 165 is used to fix the state of the locating pin 162 when it is pulled out of the locating groove 141.

[0057] In this embodiment, a connecting groove 151 matching the edge structure of the positioning plate 140 is further provided on the side wall of the connecting rod 150, which is used to strengthen the connection between the connecting rod 150 and the positioning plate 140, ensure the consistent position of the positioning assembly 160, and avoid the diameter of the new structure being larger than the diameter of the original lifting rod 100.

[0058] Further, a handle ring 112 is installed in the middle of the adjusting tube 110. The handle ring 112 is a ring sleeve arranged on the adjusting tube 110, and a plurality of handles are arranged on the outer wall of the ring sleeve, and the handle ring 112 facilitates the rotation operation of the adjusting tube 110.

[0059] Internal threads are respectively provided at both ends of the lumen of the adjusting tube 110, and the threads at both ends of the lumen of the adjusting tube are rotated in opposite directions. External threads are provided at both ends of the upper adjusting rod 120 and the lower adjusting rod 130, and the upper adjusting rod 120 and the lower adjusting rod 130 are threadedly connected to the adjusting tube 110. The length of the upper and lower adjusting rods can be changed by rotating the adjusting tube, and this adjustment method is more convenient and quick to meet the assembly requirements of different machines.

[0060] The adjustment method of the lifting rod 100 in this embodiment is:

[0061] Insert the connecting rod 150 into the connecting tube 111 and fix it. When the upper / lower adjusting rod is screwed out / in, the pull ring 166 is clamped on the clamping block 165, so that the positioning pin 162 is in a locked state when it is pulled out of the positioning groove 141. The connecting rod 150 can adaptively adjust the distance between the positioning assembly 160 and the adjusting tube 110 by its own scalability.

[0062] When the position of the up / down adjusting rod is determined, the pull ring 166 is unlocked, and the positioning pin 162 is inserted into the positioning groove 141 to prevent the up / down adjusting rod from rotating.

[0063] Second embodiment

[0064] See also Figure 4 The structure of the lifting rod 100 of the three-point suspension device in this embodiment is roughly the same as the structure of the lifting rod 100 in the first embodiment, except that: the connecting rod 150 is not a telescopic rod, but a rod body having a plurality of first positioning holes arranged in a straight line and at equal intervals, and the connecting rod 150 passes through the connecting tube 111; a second positioning hole is provided on the corresponding connecting tube 111, and the connecting rod 150 can be fixed to the adjusting tube 110 by inserting a bolt into the second positioning hole and the first positioning hole, and the protruding length of the connecting rod 150 can be adjusted by loosening the bolt, so as to adapt the screw-out / screw-in length of the upper / lower adjusting rod.

[0065] The lifting rod 100 in this embodiment is used as follows:

[0066] Loosen the bolts, insert the positioning pin 162 into the positioning slot 141, and the upper / lower adjustment rod adaptively adjusts the extension length of the connecting rod 150 during the process of screwing out / in;

[0067] After the screwing-out / screwing-in length is determined, the bolts are tightened to fix the connecting rod 150 .

[0068] Third embodiment

[0069] This embodiment provides an agricultural machine with a three-point suspension device, and the agricultural machine uses the three-point suspension device lifting rod 100 in the first embodiment or the second embodiment.

[0070] In summary, the benefits of the present invention are:

[0071] 1. A fixed connecting rod 150 with adjustable extension length is provided at the connecting pipe 111, so that the connecting rod 150 can be adapted in length when the upper / lower adjusting rod is screwed out / in;

[0072] 2. A positioning plate 140 is provided on the rod body of the upper / lower adjusting rod, and a positioning assembly 160 is provided on the connecting rod 150, so that after the screwing-out / screwing-in length of the upper / lower adjusting rod is determined, the positioning assembly 160 is used to lock the upper / lower adjusting rod, thereby preventing the adjusting tube 110 from rotating due to accidental touch or vibration, causing the length of the upper adjusting rod 120 and the lower adjusting rod 130 to change.

[0073] This specification describes examples of embodiments of the utility model, and it is not intended that these embodiments illustrate and describe all possible forms of the utility model. It should be understood that the embodiments in the specification can be implemented in a variety of alternative forms. The drawings do not need to be drawn to scale; some features can be enlarged or reduced to show the details of specific components. The specific structural and functional details disclosed should not be interpreted as limiting, but are merely representative bases for teaching those skilled in the art to implement the utility model in various forms. It should be understood by those skilled in the art that the multiple features illustrated and described with reference to any of the drawings can be combined with the features illustrated in one or more other drawings to form embodiments that are not explicitly described or described. The described combined features provide representative embodiments for typical applications. However, various combinations and variations of features consistent with the teachings of the utility model can be used for specific applications or implementations as needed.

[0074] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A lifting rod of a three-point suspension device, the lifting rod comprising an adjusting tube and an upper adjusting rod and a lower adjusting rod respectively arranged at both ends of the adjusting tube and threadedly connected to the adjusting tube, characterized in that: A positioning plate is sleeved on the rod body of the upper adjusting rod and the lower adjusting rod, and a plurality of positioning grooves are arranged on the positioning plate; one or more connecting tubes are respectively arranged on the outer walls of the two end tubes of the adjusting tube; a connecting rod is assembled in the connecting tube, and the distance that the connecting rod extends out of the connecting tube is adjustable to adapt to the screw-out length of the upper adjusting rod or the lower adjusting rod; a positioning assembly is arranged on the upper part of the connecting rod, and the positioning assembly is inserted into the positioning groove to fix the screw-out length of the upper adjusting rod or the lower adjusting rod.

2. The three-point hitch lifting rod according to claim 1, characterized in that: The positioning component comprises: A pin frame, wherein the pin frame is a frame body with an open space in the middle, and the upper and lower ends of the pin frame are respectively provided with a first through hole and a second through hole that penetrates the open space from top to bottom; A positioning pin, the positioning pin passes through the first through hole, the open space and the second through hole, and the shape and size of the bottom of the positioning pin match the shape and size of the positioning groove; The spring is assembled in the open space and sleeved on the positioning pin. When the positioning pin is pulled out of the positioning groove, the spring is compressed.

3. The three-point hitch lifting rod according to claim 2, characterized in that: The positioning assembly also includes a pull ring, which is fixedly arranged on the upper part of the positioning pin.

4. The three-point hitch lifting rod according to claim 3, characterized in that: A clamping block is also provided on the upper part of the pin shaft frame. After the position of the locating pin is determined, the pull ring is clamped on the clamping block to fix the locating pin.

5. The three-point hitch lifting rod according to claim 1, characterized in that: The connecting rod is also provided with a connecting groove matching the edge structure of the positioning plate.

6. The three-point hitch lifting rod according to claim 1, characterized in that: A handle ring is installed in the middle of the adjusting tube.

7. The three-point suspension lifting rod according to any one of claims 1 to 6, characterized in that: The connecting pipe and the connecting rod are assembled in a detachable connection.

8. The three-point hitch lifting rod according to claim 7, characterized in that: The detachable connection includes a snap connection or a threaded connection.

9. The three-point suspension lifting rod according to any one of claims 1 to 6, characterized in that: The connecting pipe and the connecting rod are assembled in a fixed connection manner, and the connecting rod is a telescopic rod with a locking structure.

10. An agricultural machine, characterized in that: The invention comprises a lifting rod of a three-point suspension device as described in any one of claims 1-9.

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