Electric telescopic tow hook

Abstract

The utility model discloses an electric telescopic trailer hook which comprises a hook body and a driving assembly, the hook body comprises a mounting part, a connecting part and a ball head, the mounting part is connected with the driving assembly, the connecting part is connected with the mounting part and the ball head, the ball head is used for hanging an object, the driving assembly is arranged on an assembly frame, and the assembly frame is arranged on the mounting frame; the driving assembly comprises a shell, a power unit and a locking unit, the shell is limited to the assembly frame, the locking unit is arranged in the shell and connected with the hook body, the locking unit is used for locking the hook body located at the storage position or the unfolding hanging position, and the power unit is arranged on the shell and used for driving the hook body to stretch out of the vehicle or retract into the vehicle; according to the electric telescopic tow hook, the power unit and the locking unit are adopted, the hook body can be driven to rotate in place, locking can be conducted when the tow hook rotates to the containing position or the unfolding hanging position, the tow hook is prevented from shaking, the stability of hung objects is guaranteed, and the tow hook is protected.

Description

Technical Field

[0001] The utility model relates to the technology of automobile trailer hooks, in particular to an electric telescopic trailer hook. Background Art

[0002] With the continuous change of people's lifestyle, more and more people have more requirements for the mounting performance of automobiles. The electric trailer hooks installed on existing automobiles are kept installed on the vehicle body of the automobile. The rotation of the tow hook can be controlled by a motor, so that the tow hook can be rotated to a storage position inside the vehicle body or rotated to an extended position outside the vehicle body for mounting according to actual needs. However, in the prior art, when the trailer hook is in the extended position or the storage position, there is no locking mechanism to lock the trailer hook. During the driving of the vehicle, when turning or on rough roads, the force on the trailer hook is relatively large, which is extremely likely to cause the trailer hook to swing during mounting or storage, not only reducing the stability of the object mounted by the trailer hook, but also causing the trailer hook to impact the vehicle body to generate abnormal noises or even damage. Content of the Utility Model

[0003] To solve the defects of the above-mentioned prior art, the utility model provides an electric telescopic trailer hook, which can be locked when the trailer hook is in the storage position or the extended mounting position, prevent the trailer hook from shaking, ensure the stability of the mounted object, and protect the trailer hook.

[0004] To achieve the above technical purpose, the utility model adopts the following technical scheme: an electric telescopic trailer hook, comprising a hook body and a driving component. The hook body includes a mounting part, a connecting part and a ball head. The mounting part is connected with the driving component. The connecting part connects the mounting part and the ball head. The ball head is used for mounting an object. The driving component is arranged on an assembly frame, and the assembly frame is arranged on a mounting frame.

[0005] The driving component includes a housing, a power unit and a locking unit. The housing is defined on the assembly frame. The locking unit is arranged in the housing and connected with the hook body. The locking unit is used to lock the hook body in the storage position or the extended mounting position for locking. The power unit is arranged on the outer shell and used to drive the hook body to extend out of the vehicle or retract into the vehicle.

[0006] Preferably, mounting plates are arranged on both sides of the mounting frame. A plurality of bolt holes are arranged on the mounting plates. Fixing bolts are fitted on the bolt holes. The fixing bolts fix the mounting plates to the vehicle body. Reinforcing plates are arranged on the mounting plates.

[0007] Preferably, a wiring hole is arranged on the connecting part. Positioning columns are respectively arranged on both sides of the connecting part.

[0008] Preferably, an assembly plate is arranged on the outer periphery of the housing. Assembly bolts are arranged at the four corners of the assembly plate. The assembly bolts are used to fix the assembly plate and the assembly frame.

[0009] Preferably, the connecting portion and the mounting portion are arranged at 45 degrees, and the mounting frame and the assembly frame are arranged at 45 degrees.

[0010] Preferably, the power unit includes a motor fixed to the outer cover. The outer cover is covered on one end of the housing relative to the hook body through assembly bolts. The output shaft of the motor extends into the outer cover and is sleeved with a bevel gear, which meshes with a bevel gear disk. The bevel gear disk is sleeved on a first-stage sun gear, and the first-stage sun gear meshes with a first-stage planetary gear. The first-stage planetary gear is rotatably connected to the planetary carrier through a first-stage rotating shaft. A second-stage sun gear is provided at the center on one side of the planetary carrier relative to the first-stage planetary gear. The second-stage sun gear meshes with a second-stage planetary gear, and the second-stage planetary gear is rotatably connected to the driving disk through a second-stage rotating shaft. A gear ring is nested on the inner wall of the housing, and the gear ring meshes with the first-stage planetary gear and the second-stage planetary gear.

[0011] Preferably, an installation groove is provided on one side of the mounting portion facing the housing. Symmetrically arranged mounting blocks are provided in the installation groove, and mounting holes are provided in the mounting holes. The mounting holes are fitted with mounting bolts. One end of the housing relative to the outer cover is fitted into the installation groove. A convex platform extending inward is provided at one end of the housing extending into the installation groove. A limiting block is provided inside the housing, and a convex ring is provided outside the limiting block. The side wall of the convex ring is attached to the inner wall of the housing to limit the convex platform in the installation groove. Threaded holes are provided on both sides of the limiting block, and a sliding groove is provided between the two threaded holes. The mounting bolts are in threaded cooperation with the threaded holes, and the mounting bolts fix the limiting block to the mounting portion.

[0012] Preferably, a limiting groove is provided on one side of the driving disk relative to the second-stage planetary gear. The side walls on both sides of the limiting groove each include a spreading portion, a limiting portion, and a contracting portion. The limiting portion is located between the spreading portion and the contracting portion, and the limiting portion is shaped to conform to the side wall of the clamping block. The distance from the spreading portion to the center of the driving disk gradually decreases from one end close to the limiting portion to the end away from the limiting portion, and the distance from the contracting portion to the center of the driving disk gradually increases from one end close to the limiting portion to the end away from the limiting portion.

[0013] Preferably, the locking unit includes two clamping blocks and a spring. The bottom ends of the two clamping blocks are both located in the limiting groove, and the top ends of the two clamping blocks are both located in the sliding groove. Through holes are provided at the top and bottom of one side of each clamping block facing the second-stage sun gear. The two ends of the spring respectively extend into the through holes at the bottoms of the two clamping blocks. Two grooves are provided on the inner wall of the convex platform, which cooperate with the clamping blocks. A positioning groove is provided on the inner wall of the housing, and a positioning block is provided on the outside of the driving disk. The positioning block extends into the positioning groove and moves along the positioning groove.

[0014] Preferably, a corrugated gasket is provided between the bottom wall of the installation groove and the housing, and a sealing ring is provided between the inner side wall of the installation groove and the outer side wall of the housing.

[0015] In summary, the present utility model has achieved the following technical effects:

[0016] The electric telescopic trailer hitch of the present utility model adopts a power unit and a locking unit, which can not only drive the hook body to rotate in place, but also lock the trailer hitch when it rotates to the storage position or the deployed mounting position, preventing the trailer hitch from shaking, ensuring the stability of the mounted object, and protecting the trailer hitch. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of the electric telescopic trailer hitch of the present utility model;

[0018] Figure 2 is a schematic structural diagram of the electric telescopic trailer hitch of the present utility model;

[0019] Figure 3 is a schematic structural diagram of the mounting bracket of the electric telescopic trailer hitch of the present utility model;

[0020] Figure 4 is a schematic connection structure diagram of the motor and the hook body of the electric telescopic trailer hitch of the present utility model;

[0021] Figure 5 is a schematic connection structure diagram of the motor and the hook body of the electric telescopic trailer hitch of the present utility model;

[0022] Figure 6 is a schematic structural diagram of the hook body of the electric telescopic trailer hitch of the present utility model;

[0023] Figure 7 is a schematic structural diagram of the hook body of the electric telescopic trailer hitch of the present utility model;

[0024] Figure 8 is a schematic internal structure diagram of the electric telescopic trailer hitch of the present utility model;

[0025] Figure 9 is a schematic internal structure diagram of the electric telescopic trailer hitch of the present utility model;

[0026] Figure 10 is a schematic structural diagram of the drive disk of the electric telescopic trailer hitch of the present utility model;

[0027] Figure 11 is a schematic diagram of the expanded state of the latch of the electric telescopic trailer hitch of the present utility model;

[0028] Figure 12 is a schematic retraction structure diagram of the latch of the electric telescopic trailer hitch of the present utility model;

[0029] Figure 13It is a schematic structural diagram of the limit block of the electric telescopic trailer hitch of the present utility model;

[0030] Figure 14 It is a schematic diagram of the locked state of the electric telescopic trailer hitch of the present utility model;

[0031] Explanation of the reference numerals in the drawings of the specification: 1. Mounting frame; 2. Mounting plate; 3. Reinforcing plate; 4. Assembly frame; 5. Hook body; 51. Mounting part; 52. Connecting part; 53. Ball head; 54. Wiring hole; 55. Positioning column; 56. Mounting block; 57. Mounting hole; 6. Motor; 7. Assembly plate; 8. Assembly bolt; 9. Housing; 10. Mounting bolt; 11. Bevel gear disk; 12. First-stage sun gear; 13. First-stage planetary gear; 14. Planet carrier; 15. Second-stage planetary gear; 16. Ring gear; 17. Driving disk; 18. Clamping block; 19. Spring; 20. Wave washer; 21. Sealing ring; 22. Outer cover; 23. Through hole; 24. Assembly bolt; 25. Positioning groove; 26. Limit groove; 27. Limit block; 28. Mounting screw hole; 29. Slide groove. Detailed implementation manners

[0032] The present utility model will be further described in detail below with reference to the drawings.

[0033] This specific embodiment is only an explanation of the present utility model, and it is not a limitation of the present utility model. Those skilled in the art can make modifications without creative contributions to this embodiment after reading this specification, but as long as it is within the scope of the claims of the present utility model, it is protected by the Patent Law.

[0034] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying 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 of the present utility model.

[0035] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, "a plurality" means two or more, unless otherwise specifically defined.

[0036] In the present utility model, unless otherwise clearly defined and limited, terms such as "installation", "connection", "linkage", "fixation", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral body; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0037] In the present utility model, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature is at a higher horizontal level than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature is at a lower horizontal level than the second feature.

[0038] Embodiment 1:

[0039] As Figure 1 As shown in FIG. - 3, an electric telescopic trailer hitch includes a hook body 5, a drive assembly and a mounting bracket 1. Mounting plates 2 are provided on both sides of the mounting bracket 1. A plurality of bolt holes are provided on the mounting plates 2, and fixing bolts are fitted in the bolt holes. The fixing bolts fix the mounting plates 2 to the vehicle body, and reinforcing plates 3 are provided on the mounting plates 2; the connecting portion 52 and the mounting portion 51 are arranged at an angle of 45 degrees, and the mounting bracket 1 and the assembly bracket 4 are arranged at an angle of 45 degrees.

[0040] The electric telescopic trailer hitch of this embodiment adopts a power unit and a locking unit, which can not only drive the hook body 5 to rotate in place, but also lock the trailer hitch when it rotates to the storage position or the deployed mounting position, prevent the trailer hitch from shaking, ensure the stability of the mounted object, and protect the trailer hitch.

[0041] As Figure 4 As shown in FIG. - 5, the drive assembly is arranged on the assembly bracket 4, and the assembly bracket 4 is arranged on the mounting bracket 1; the drive assembly includes a housing 9, a power unit and a locking unit. The housing 9 is defined on the assembly bracket 4. The locking unit is arranged inside the housing 9 and is connected to the hook body 5. The locking unit is used to lock the hook body 5 in the storage position or the deployed mounting position for locking. The power unit is arranged on the outer shell and is used to drive the hook body 5 to extend out of the vehicle or retract into the vehicle.

[0042] As Figure 6As shown in FIGS. 6-7, the hook body 5 includes a mounting portion 51, a connecting portion 52, and a ball head 53. The mounting portion 51 is connected to the driving assembly. The connecting portion 52 connects the mounting portion 51 and the ball head 53. The ball head 53 is used for hanging an object. The connecting portion 52 is provided with a wiring hole 54, and positioning columns 55 are respectively arranged on both sides of the connecting portion 52. The wiring hole 54 is used for arranging electric wires or communication lines to connect the vehicle and the hanging object. The positioning columns 55 are used for assisting in positioning, so that the contact positions between the hook body 5 and the hanging object increase from only one place of the ball head 53 to three places including the ball head 53 and the two positioning columns 55, preventing the hanging object from shaking and improving the stability of the hanging object.

[0043] An assembly plate 7 is arranged on the outer periphery of the housing 9, and assembly bolts 8 are arranged at the four corners of the assembly plate 7. The assembly bolts 8 are used for fixing the assembly plate 7 and the assembly frame 4.

[0044] As Figure 8 As shown in FIGS. 8-9, the power unit includes a motor 6. The motor 6 is fixed to the outer cover 22. The outer cover 22 is covered on one end of the housing relative to the hook body 5 through an assembly bolt 24. The output shaft of the motor 6 extends into the outer cover 22 and is sleeved with a bevel gear. The bevel gear meshes with a bevel gear disk 11. The bevel gear disk 11 is sleeved on a first-stage sun gear 12. The first-stage sun gear 12 meshes with a first-stage planetary gear 13. The first-stage planetary gear 13 is rotatably connected to a planetary carrier 14 through a first-stage rotating shaft. A second-stage sun gear is arranged at the center of one side of the planetary carrier 14 relative to the first-stage planetary gear 13. The second-stage sun gear meshes with a second-stage planetary gear 15. The second-stage planetary gear 15 is rotatably connected to a driving disk 17 through a second-stage rotating shaft. A toothed ring 16 is nested on the inner wall of the housing 9. The toothed ring 16 meshes with the first-stage planetary gear 13 and the second-stage planetary gear 15.

[0045] As Figure 13 As shown, a mounting groove is arranged on one side of the mounting portion 51 facing the housing 9. Symmetrically arranged mounting blocks 56 are arranged in the mounting groove. The mounting hole 57 is provided with a mounting hole 57. The mounting hole 57 is matched with a mounting bolt 10. One end of the housing 9 relative to the outer cover 22 is fitted into the mounting groove. A convex platform extending inward is arranged at one end of the housing 9 extending into the mounting groove. A limiting block 27 is arranged in the housing 9. A convex ring is arranged on the outer side of the limiting block 27. The side wall of the convex ring is attached to the inner wall of the housing to be used for limiting the convex platform in the mounting groove. Mounting screw holes 28 are arranged on both sides of the limiting block 27. A sliding groove 29 is arranged between the two mounting screw holes 28. The mounting screw holes 28 are in threaded cooperation with the mounting bolts 10. The mounting bolts 10 fix the limiting block 27 to the mounting portion 51.

[0046] As Figure 10As shown, a limiting groove 26 is provided on one side of the driving disk 17 relative to the secondary planetary gear 15. Both side walls of the limiting groove 26 include a spreading portion, a limiting portion, and a contracting portion. The limiting portion is located between the spreading portion and the contracting portion. The limiting portion is shaped to fit the side wall of the clamping block 18. The distance from the spreading portion to the center of the driving disk 17 gradually decreases from the end close to the limiting portion to the end far from the limiting portion. The distance from the contracting portion to the center of the driving disk 17 gradually increases from the end close to the limiting portion to the end far from the limiting portion.

[0047] The locking unit includes two clamping blocks 18 and a spring 19. The bottom ends of the two clamping blocks 18 are both located in the limiting groove 26, and the top ends of the two clamping blocks 18 are both located in the sliding groove 29. Through holes 23 are provided at the top and bottom of the clamping block 18 on the side facing the secondary sun gear. The two ends of the spring 19 respectively extend into the through holes 23 at the bottom of the two clamping blocks 18. Two grooves are provided on the inner wall of the boss, and the grooves cooperate with the clamping blocks 18. A positioning groove 25 is provided on the inner wall of the housing. A positioning block is provided on the outer side of the driving disk 17, and the positioning block extends into the positioning groove 25 and moves along the positioning groove 25. The spring 19 is arranged in the through hole 23 at the bottom of the clamping block 18, which can directly apply the spreading force to the bottom of the clamping block 18, and the bottom of the clamping block 18 is also in direct contact with the driving disk 17 to receive the thrust. The two forces act at the same position, avoiding the bottom of the clamping block 18 from tilting and separating from the driving disk 17, preventing the entire trailer hitch from getting stuck. Through holes 23 are also provided at the top of the clamping block 18 to facilitate the assembly of the clamping block.

[0048] The angle between the two grooves is 180 degrees, and the angle of the positioning groove 25 minus the angle of the positioning block is 270 degrees.

[0049] A corrugated gasket 20 is provided between the bottom wall of the installation groove and the housing 9, and a sealing ring 21 is provided between the inner side wall of the installation groove and the outer side wall of the housing 9. The corrugated gasket 20 is used to spread the installation portion 51 and the housing 9, so that the housing 9 is tightly attached to the limiting block 27. The sealing ring 21 is used to seal the installation portion 51 and the housing 9 to prevent water vapor or foreign objects from entering.

[0050] Working principle: When hanging an object, the hook body 5 needs to be rotated from the storage position to the hanging position. The state of the clamping block 18 is as Figure 14As shown, the hook body 5 is in the locked state, and neither the clamping block 18 nor the hook body 5 can rotate. That is, the clamping block 18 is stuck in the groove, and the clamping block 18 is also in the limiting part. Therefore, unlocking is required first: First, the motor 6 drives the bevel gear to rotate, driving the bevel gear disc 11 and the first-stage sun gear 12 to rotate, driving the first-stage planetary gear 13 to rotate around the ring gear 16, realizing the rotation of the planet carrier 14, and then driving the second-stage sun gear to rotate, so that the second-stage planetary gear 15 rotates around the ring gear 16, realizing the rotation of the driving disc 17, so that the clamping block 18 moves out of the limiting part and enters the contraction part. Since the side wall of the contraction part is closer to the center of the driving disc 17 as it is farther away from the limiting part, the two clamping blocks 18 are pushed inward. When the clamping block 18 moves to the end of the contraction part, the two clamping blocks 18 are closest to each other at this time, and the clamping block 18 disengages from the groove, thus unlocking the state. Then the driving disc 17 continues to rotate, driving the clamping block 18 to rotate until the positioning block moves to the end of the positioning groove 25. At this time, the clamping block 18 just rotates 180 degrees, and the two clamping blocks 18 exchange grooves. The hook body 5 rotates outward to the outside of the vehicle. The motor 6 reverses, driving the driving disc 17 to move in the reverse direction. The clamping block 18 is separated from the driving disc 17, and the clamping block 18 is pushed outward by the spring 19 until as Figure 11 shown, the clamping block 18 enters the limiting part. At this time, the clamping block 18 is completely stuck in the groove, and when in the mounting position, the hook body 5 is locked;

[0051] When there is no need to mount an object, the hook body 5 needs to be rotated from the mounting position to the storage position. The state of the clamping block 18 is as Figure 14 shown. The hook body 5 is in the locked state, and neither the clamping block 18 nor the hook body 5 can rotate. That is, the clamping block 18 is stuck in the groove, and the clamping block 18 is in the limiting part. Therefore, unlocking is required first: First, the motor 6 continues to reverse to drive the bevel gear to rotate, driving the bevel gear disc 11 and the first-stage sun gear 12 to rotate, driving the first-stage planetary gear 13 to rotate around the ring gear 16, realizing the rotation of the planet carrier 14, and then driving the second-stage sun gear to rotate, so that the second-stage planetary gear 15 rotates around the ring gear 16, realizing the rotation of the driving disc 17, so that the clamping block 18 moves out of the limiting part and enters the expansion part. Since the side wall of the expansion part is closer to the center of the driving disc 17 as it is farther away from the limiting part, the two clamping blocks 18 are pushed inward. When the clamping block 18 moves to the end of the expansion part, the two clamping blocks 18 are closest to each other at this time, and the clamping block 18 disengages from the groove, thus unlocking the state. Then the driving disc 17 continues to rotate, driving the clamping block 18 to rotate until the positioning block moves to the other end of the positioning groove 25, as Figure 12 shown. At this time, the clamping block 18 just rotates 180 degrees, and the two clamping blocks 18 exchange grooves. The hook body 5 rotates inward to the inside of the vehicle. At this time, the motor 6 resumes forward rotation, driving the driving disc 17 to move forward. The clamping block 18 is separated from the driving disc 17, and the clamping block 18 is pushed outward by the spring 19 until the clamping block 18 enters the limiting part. At this time, the clamping block 18 is completely stuck in the groove, and when in the storage position, the hook body 5 is locked.

[0052] The above description is only a preferred embodiment of the present utility model and does not impose any formal limitations on the present utility model. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present utility model are all within the scope of the technical solution of the present utility model.

Claims

1. An electric telescopic trailer hook, characterized in that: It comprises a hook body and a driving assembly, wherein the hook body comprises a mounting portion, a connecting portion and a ball head, wherein the mounting portion is connected to the driving assembly, the connecting portion connects the mounting portion and the ball head, the ball head is used to mount an object, the driving assembly is arranged on an assembly frame, and the assembly frame is arranged on a mounting frame; The driving assembly includes a shell, a power unit and a locking unit. The shell is limited to the assembly frame. The locking unit is arranged in the shell and connected to the hook body. The locking unit is used to lock the hook body in the storage position or the unfolded mounting position. The power unit is arranged in the outer shell and is used to drive the hook body to extend out of the vehicle or retract into the vehicle.

2. The electric telescopic trailer hook according to claim 1, characterized in that: Both sides of the mounting frame are provided with mounting plates, the mounting plates are provided with a plurality of bolt holes, the bolt holes are matched with fixing bolts, the fixing bolts fix the mounting plates to the vehicle body, and the mounting plates are provided with reinforcing plates.

3. The electric telescopic trailer hook according to claim 1, characterized in that: The connecting portion is provided with a wiring hole, and positioning columns are respectively provided on both sides of the connecting portion.

4. The electric telescopic trailer hook according to claim 1, characterized in that: An assembly plate is arranged on the outer periphery of the shell, and assembly bolts are arranged at the four corners of the assembly plate, and the assembly bolts are used to fix the assembly plate and the assembly frame.

5. The electric telescopic trailer hook according to claim 1, characterized in that: The connecting portion and the mounting portion are arranged at 45 degrees, and the mounting frame and the assembly frame are arranged at 45 degrees.

6. The electric telescopic trailer hook according to claim 1, characterized in that: The power unit includes a motor, which is fixed to an outer cover, and the outer cover is covered by an assembly bolt on one end of the outer shell relative to the hook body. The motor output shaft extends into the outer cover and is sleeved with a bevel gear, which meshes with a bevel gear plate, and the bevel gear plate is sleeved on a primary sun gear, which meshes with a primary planetary gear, and the primary planetary gear is rotatably connected to a planet carrier through a primary rotating shaft. A secondary sun gear is provided at the center of one side of the planet carrier relative to the primary planetary gear, and the secondary sun gear and the secondary planetary gear, and the secondary planetary gear are rotatably connected to a drive disk through a secondary rotating shaft, and a gear ring is embedded in the inner wall of the shell, and the gear ring is meshed with the primary planetary gear and the secondary planetary gear.

7. The electric telescopic trailer hook according to claim 6, characterized in that: The mounting portion is provided with a mounting groove toward one side of the shell, a symmetrically arranged mounting block is provided in the mounting groove, the mounting hole is provided with a mounting hole, and the mounting hole is matched with a mounting bolt, the shell is matched with the mounting groove at one end relative to the outer cover, and the shell is provided with a boss extending inward at one end extending into the mounting groove, a limit block is provided in the shell, a convex ring is provided on the outer side of the limit block, and the side wall of the convex ring is fitted with the inner wall of the shell to limit the boss in the mounting groove, screw holes are installed on both sides of the limit block, a slide groove is provided between the two mounting screw holes, the mounting screw holes are threadedly matched with the mounting bolts, and the mounting bolts fix the limit block to the mounting portion.

8. The electric telescopic trailer hook according to claim 7, characterized in that: The driving disk is provided with a limiting groove on one side relative to the secondary planetary gear, and the side walls on both sides of the limiting groove include an expansion portion, a limiting portion and a contraction portion, the limiting portion is located between the expansion portion and the contraction portion, and the limiting portion is contoured with the side wall of the block, and the distance from the expansion portion to the center of the driving disk gradually decreases from one end close to the limiting portion to one end away from the limiting portion, and the distance from the contraction portion to the center of the driving disk gradually increases from one end close to the limiting portion to one end away from the limiting portion.

9. The electric telescopic trailer hook according to claim 8, characterized in that: The locking unit includes two blocks and a spring, the bottom ends of the two blocks are located in the limiting grooves, the top ends of the two blocks are located in the sliding grooves, the top and bottom of the blocks facing the secondary sun gear are provided with through holes, the two ends of the spring respectively extend into the through holes located at the bottom of the two blocks, the inner wall of the boss is provided with two grooves, the grooves cooperate with the blocks, the inner wall of the outer shell is provided with a positioning groove, and a positioning block is provided on the outer side of the driving disk, the positioning block extends into the positioning groove and moves along the positioning groove.

10. The electric telescopic trailer hook according to claim 1, characterized in that: A corrugated gasket is provided between the bottom wall of the installation groove and the shell, and a sealing ring is provided between the inner side wall of the installation groove and the outer side wall of the shell.

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