An electric tailgate strut with a damper

Abstract

The present invention relates to an electric tailgate strut with a damper, which comprises a fixed rod assembly, a moving rod assembly and a bearing spring. The fixed rod assembly includes an outer sleeve, a lead screw, a driving motor and a damper. The moving rod assembly includes an inner sleeve, a guide sleeve and a connecting assembly. The outer sleeve and the inner sleeve are coaxially sleeved. The guide sleeve is coaxially installed inside the inner sleeve. One end of the lead screw is movably connected to the guide sleeve through the connecting assembly, and the other end passes through the damper and is connected to the output end of the driving motor. The damper includes a damper housing and a resistance increasing component. The resistance increasing component includes a resistance increasing block and a limiting mechanism. A plurality of annular elastic friction elements are provided on the outer peripheral surface of the resistance increasing block. The annular elastic friction elements are in interference fit with the inner wall of the damper housing. The limiting mechanism confines the resistance increasing block within the damper housing. One end of the lead screw penetrates into the resistance increasing block and is connected to the resistance increasing block through a linkage structure, and generates a damping torque that resists the non-driven rotation of the lead screw by friction with the inner wall of the damper housing.

Description

Technical Field

[0001] The present invention relates to the field of tailgate push rod dampers, and particularly to an electric tailgate strut with a damper. Background Art

[0002] In an automotive electric tailgate control system, a damper is a core component to ensure smooth opening and closing of the tailgate. In the prior art, a friction damper represented by the patent "CN 105735819 B" widely adopts a mechanical friction structure of friction plates, friction gaskets and pressure springs. Its working principle is to force the friction plate to contact the friction gasket through the spring pre-tightening force, and use the sliding friction force to generate a damping effect. Although this solution solves the problem of insufficient tailgate support force to a certain extent, there are still the following significant defects:

[0003] 1. The damper of the prior art requires multiple friction plates and friction gaskets to be alternately stacked, in cooperation with a pressure spring and a spline assembly, resulting in a large number of parts and a cumbersome assembly process.

[0004] 2. During the operation of the damper of the prior art, since the friction plate is in a high-speed sliding friction state for a long time, it is easy for the surface roughness to increase due to wear, which in turn causes damping force attenuation. It is necessary to perform frequent maintenance or replacement, and the pressure spring is prone to plastic deformation under long-term compression, further exacerbating the problem of unstable damping force and having a short service life. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an electric tailgate strut with a damper in view of the above deficiencies of the prior art.

[0006] To achieve the above object, the present invention provides the following technical solution: An electric tailgate strut with a damper, comprising a fixed rod assembly, a moving rod assembly that moves axially relative to the fixed rod assembly to achieve telescopic movement, and a load-bearing spring. The fixed rod assembly includes an outer sleeve, a lead screw rotatably disposed within the outer sleeve, a drive motor, and a damper. The moving rod assembly includes an inner sleeve, a guide sleeve, and a coupling assembly. The outer sleeve and the inner sleeve are coaxially sleeved. The guide sleeve is coaxially installed inside the inner sleeve. One end of the lead screw is movably connected to the guide sleeve through the coupling assembly, and the other end passes through the damper and is connected to the output end of the drive motor. The damper includes a damper housing installed within the outer sleeve and a resistance increasing component installed within the damper housing. The resistance increasing component includes a plurality of resistance increasing blocks and a limiting mechanism. The outer peripheral surface of the resistance increasing block is provided with a plurality of annular elastic friction elements. The annular elastic friction elements are in interference fit with the inner wall of the damper housing. The limiting mechanism restricts the resistance increasing block within the damper housing. One end of the lead screw penetrates into the resistance increasing block and is connected to the resistance increasing block through a linkage structure, and generates a damping torque that resists the non-driven rotation of the lead screw by friction with the inner wall of the damper housing. Lubricating grease is filled between the annular elastic friction element and the inner wall of the damper housing, and the lubricating grease adheres to the annular elastic friction element.

[0007] With the above technical solution, the electric tailgate strut drives the lead screw to rotate through a drive motor. The lead screw drives the guide sleeve and the inner sleeve to axially expand and contract relative to the outer sleeve through a coupling component, thereby realizing the opening and closing actions of the electric tailgate. During the rotation of the lead screw, since one end of the lead screw penetrates into the resistance increasing block and is connected to the resistance increasing block through a linkage structure, the lead screw will drive the resistance increasing block to rotate together. Several annular elastic friction elements are provided on the outer peripheral surface of the resistance increasing block, and these annular elastic friction elements are in interference fit with the inner wall of the damper housing. Therefore, when the resistance increasing block rotates, the annular elastic friction elements will generate friction with the inner wall of the damper housing, generating a damping torque that resists the non-driven rotation of the lead screw, thereby realizing the damping effect. The elastic deformation of the annular elastic friction elements generates a radial contact pressure, so as to generate a damping torque that resists the non-driven rotation of the lead screw when rubbing against the inner wall of the housing. The physical property of the interference fit enables the annular elastic friction elements to maintain a stable frictional force relying on their own elastic deformation without the intervention of an external pre-tightening force, and its elastic property can adaptively compensate for the contact pressure fluctuations caused by wear or temperature changes. The limiting mechanism rigidly restricts the axial displacement of the resistance increasing block to ensure that the contact area between the annular elastic friction elements and the inner wall of the housing is always in an interference state, avoiding the separation or eccentricity of the friction elements from the housing caused by the axial component force generated by the rotation of the lead screw. Compared with the prior art, the elastic deformation of the annular elastic friction elements directly generates a controllable damping torque, without relying on traditional multi-disc friction structures or spring pre-tightening devices, and the number of parts is greatly reduced. At the same time, the continuous contact design of the annular elastic friction elements makes the friction pressure distribution uniform, avoiding the damping force attenuation caused by local uneven wear. And the interference amount can be adjusted step by step for the damping torque by replacing annular elastic friction elements of different sizes to adapt to the load requirements of different vehicle models. Lubricating grease adheres to the surface of the annular elastic friction elements to reduce the dry friction wear of the friction pair, and prolongs the service life of the annular elastic friction elements by reducing the friction coefficient and inhibiting the surface oxidation of the annular elastic friction elements, realizing uniform distribution of the friction pressure. The elastic deformation characteristics of the annular elastic friction elements enable it to adaptively compensate for the contact pressure changes caused by assembly tolerances or long-term wear, ensuring the stability of the damping torque and prolonging the service life of the entire electric tailgate strut.

[0008] The above-mentioned electric tailgate strut with a damper can be further set as: the annular elastic friction element is an O-ring, a positioning groove for accommodating the O-ring is formed on the outer peripheral surface of the resistance increasing block, and the O-ring is arranged in the positioning groove and is in close contact with the inner wall of the damper housing.

[0009] Adopting the above technical solution, by providing a positioning groove on the outer peripheral surface of the resistance increasing block and accommodating an O-ring, the elastic deformation of the O-ring is utilized to form a stable interference contact with the inner wall of the damper housing. The positioning groove restricts the radial deformation direction of the O-ring to ensure uniform distribution of the contact pressure with the inner wall of the housing. The annular continuous structure of the O-ring and the geometric tolerance of the positioning groove act together to make the frictional pressure evenly transmitted circumferentially, avoiding the damping force fluctuation caused by local eccentric wear of the traditional split friction plate. At the same time, the elastic material property of the O-ring can adaptively compensate for the dimensional changes caused by wear or temperature change during long-term use, maintaining the stability of the contact pressure. The modular design of the positioning groove and the O-ring reduces the number of parts, greatly reduces the cost, and improves the assembly efficiency. At the same time, the torsional damping amount can be conveniently adjusted by increasing or decreasing the depth of the positioning groove.

[0010] The above-mentioned electric tailgate strut with a damper can also be configured as: the annular elastic friction element is a sealing sleeve, and the sealing sleeve completely or partially covers the outer peripheral surface of the resistance increasing block and is in close contact with the inner wall of the damper housing.

[0011] Adopting the above technical solution, by providing a sealing sleeve that covers the whole circumference or partially on the outer peripheral surface of the resistance increasing block as the annular elastic friction element, the elastic deformation property of the sealing sleeve is utilized to form a continuous and uniform interference contact with the inner wall of the damper housing. Its contact pressure directly generates a damping torque that resists the non-driven rotation of the lead screw through the radial deformation of the sealing sleeve. The continuous covering structure of the sealing sleeve (such as an integral silicone sleeve or a segmented fluororubber sleeve) eliminates the splicing gap of the traditional split friction plate, ensuring uniform distribution of the frictional pressure circumferentially and avoiding the damping force fluctuation caused by local poor contact. The elastic modulus design of the sealing sleeve enables it to adaptively compensate for the dimensional changes caused by temperature change or long-term wear, maintaining the stability of the contact pressure. And the sealing sleeve and the resistance increasing block are fixed by in-mold forming or gluing, etc., avoiding abnormal wear caused by relative sliding. By replacing the sealing sleeves with different thicknesses or materials, it can be modularly adapted to the needs of sedans, SUVs and commercial vehicles, greatly improving the versatility.

[0012] The above-mentioned electric tailgate strut with a damper can be further configured as: the evaporation degree of the lubricating grease ≤ 3.0%, the steel mesh oil separation rate ≤ 3.0%, and the water spray loss ≤ 1.5%.

[0013] With the above technical solution, the evaporation degree of the lubricating grease is ≤ 3.0%, the steel mesh oil separation rate is ≤ 3.0%, the operating temperature range covers -40°C to 280°C, the penetration is 245 - 260, the NLGI grade is 2 - 3, the starting torque at low temperature environment is ≤ 1300 mN·m, the running torque is ≤ 650 mN·m, the water spray loss is ≤ 1.5%. The lubricating grease maintains a stable lubricating film at high temperature (280°C) and low temperature (-40°C) through the characteristics of low evaporation degree and low oil separation rate, avoiding lubrication failure caused by grease volatilization or oil-soap separation. Among them, the starting torque ≤ 1300 mN·m and running torque ≤ 650 mN·m at low temperature (-40°C) ensure the integrity of the lubricating film, preventing dry friction between the annular elastic friction element and the inner wall of the housing during cold start. The water spray loss ≤ 1.5% guarantees the anti-scouring performance of the grease in a humid environment, avoiding the loss of lubrication function caused by rain or high-pressure water guns for car washing. The lubricating grease significantly reduces the wear amount of the annular elastic friction element under interference fit by reducing the friction coefficient and inhibiting oxidative wear. The NLGI grade 2 - 3 of the lubricating grease ensures that its softness and hardness are suitable for the friction interface, evenly filling the gap and avoiding abnormal wear caused by the rupture of the local lubricating film.

[0014] The above-mentioned electric tailgate strut with a damper can be further set as: the linkage structure includes an external spline portion provided at one end of the lead screw and a spline groove provided on the inner wall of the resistance increasing block, and the external spline portion of the lead screw penetrates into the spline groove of the resistance increasing block for cooperative linkage.

[0015] With the above technical solution, it is composed of the external spline portion at one end of the lead screw and the spline groove on the inner wall of the resistance increasing block, and realizes torque transmission and linkage through the precise cooperation of the external spline portion and the spline groove, achieving stable linkage rotation and convenient axial installation.

[0016] The above-mentioned electric tailgate strut with a damper can be further set as: an annular limiting platform and a bearing are arranged inside the damper housing, a bearing limiting groove is provided at the position corresponding to the bearing on the damper housing, a first bearing snap ring is clamped in the bearing limiting groove, the outer ring of the bearing abuts and is limited between the first bearing snap ring and the annular limiting platform, a first annular groove and a bearing positioning step are arranged on the lead screw, a second bearing snap ring is arranged in the first annular groove, and the inner ring of the bearing abuts and is limited between the second bearing snap ring and the bearing positioning step, thereby axially constraining the lead screw inside the damper housing.

[0017] With the above technical solution, a bearing limiting groove is provided at the position of the damper housing corresponding to the bearing. The first bearing snap ring is clamped in the bearing limiting groove and jointly clamps the outer ring of the bearing with the annular limiting platform to eliminate the axial displacement of the outer ring during rotation. The inner ring of the bearing realizes axial constraint through the cooperation of the second bearing snap ring and the bearing positioning step. The first annular groove and the bearing positioning step are machined on the lead screw. The second bearing snap ring is embedded in the first annular groove and jointly presses against the inner ring of the bearing with the bearing positioning step to prevent the inner ring from sliding relative to the lead screw. Compared with the traditional friction damper that relies on multiple sets of gaskets and threads to adjust the bearing preload and is prone to axial movement due to thread loosening, in this solution, through the physical locking of the snap ring and the limiting platform, the risk of loosening is completely eliminated. At the same time, the problem of damping force attenuation caused by the wear of the friction plate is avoided, the service life is improved, and the axial displacement of the lead screw in the damper is also avoided, improving the stability of the damper during operation. Moreover, the lead screw is supported by the bearing to prevent the lead screw from wobbling.

[0018] The above-mentioned electric tailgate strut with a damper can be further set as follows: The limiting mechanism includes a second annular groove provided on the lead screw, a first resistance-increasing snap ring provided in the second annular groove, and a limiting nut provided at one end of the damper housing away from the first resistance-increasing snap ring. The outer peripheral surface of the limiting nut is provided with a threaded portion threadedly connected to the inner wall of the damper housing. One end of the resistance-increasing block abuts against the limiting nut, and the other end abuts against the first resistance-increasing snap ring.

[0019] With the above technical solution, the first resistance-increasing snap ring is embedded in the second annular groove on the lead screw. One end of the resistance-increasing block abuts against this snap ring, and the other end abuts against the limiting nut, forming a two-way rigid limit to eliminate the axial movement of the resistance-increasing block during the rotation of the lead screw. The outer peripheral surface of the limiting nut is provided with a threaded portion matching the inner wall of the damper housing. By rotating the nut, its axial position is adjusted, thereby controlling the contact pressure between the resistance-increasing block and the inner wall of the housing, avoiding the problem that the traditional friction damper relies on spring preload and multiple sets of gaskets to fix the resistance-increasing block and is prone to axial loosening due to spring fatigue or gasket wear and requires frequent maintenance. Only through the rigid snap ring limit and threaded self-locking design, the risk of loosening is completely eliminated.

[0020] The above-mentioned electric tailgate strut with a damper can also be set as follows: The limiting mechanism includes a second annular groove and a third annular groove provided on the lead screw, and a first resistance-increasing snap ring and a second resistance-increasing snap ring provided in the second annular groove and the third annular groove. One end of the resistance-increasing block abuts against the first resistance-increasing snap ring, and the other end abuts against the second resistance-increasing snap ring. A limiting filling block is provided between the resistance-increasing block and the first resistance-increasing snap ring and / or the second resistance-increasing snap ring.

[0021] With the above technical solution, by providing a second annular groove and a third annular groove on the lead screw and respectively embedding a first resistance-increasing clamping ring and a second resistance-increasing clamping ring, the two ends of the resistance-increasing block are rigidly abutted against the clamping rings, forming a two-way axial constraint, completely solving the problem of unstable damping force caused by spring fatigue and uneven wear of friction plates in the traditional solution, avoiding the displacement and inclination of the resistance-increasing block, improving the stability of the damper. By filling the assembly gap between the resistance-increasing block and the clamping ring, the axial movement margin is eliminated, ensuring uniform distribution of the contact pressure and avoiding local stress concentration or uneven wear caused by the gap. By using a modular filling block to replace the traditional redundant adjustment structure, the technical defects of uneven wear of the friction pair, axial end play and low assembly efficiency are solved. There is no need for lead screws of multiple specifications. The positioning and installation of the resistance-increasing block can be ensured through several fixedly provided annular grooves and limit filling blocks. At the same time, the clamp is arranged on the outer side of the damper housing for convenient installation and fixation.

[0022] The above-mentioned electric tailgate strut with a damper can be further configured as follows: The connection assembly includes a nut and a spacer. The nut is connected to the lead screw through a non-self-locking thread structure. Among them, the lead screw is rotatably arranged in the outer sleeve through an electric drive or an external driving force, and the outer peripheral surface of the nut is threadedly connected to the guide sleeve. The spacer is installed at the end of the lead screw and is located in the guide sleeve. Washers and fastening washers are respectively arranged at both ends of the lead screw corresponding to the spacer. One end of the washer abuts against the spacer, and the other end abuts against the nut. The fastening washer is connected to the end of the lead screw and is used to limit the spacer and the washer on the lead screw.

[0023] Adopting the above technical solution, the coupling component is mainly responsible for connecting the moving rod component (inner sleeve) and the fixed rod component (outer sleeve), and at the same time allowing the moving rod component to perform telescopic movement within the fixed rod component. The nut is a part of the coupling component. The nut is connected to the lead screw through a non-self-locking thread structure, that is, the nut and the lead screw can rotate relative to each other and move axially, while also maintaining the relative position between the two. The outer peripheral surface of the nut is threadedly connected to the guide sleeve. This connection method ensures the correct positioning of the nut within the guide sleeve. The threaded connection provides fixation and support, enabling the nut to interact stably with the guide sleeve during the telescopic process of the support rod. When the lead screw rotates, the nut drives the guide sleeve and the inner sleeve to enter or disengage from the outer sleeve, thereby realizing the telescopic movement of the moving rod component. The cushion block is installed at the end of the lead screw to ensure the correct position and stable operation of the lead screw within the outer sleeve, preventing the nut from slipping off the lead screw when it rotates. The combined use of the cushion block, washer, and fastening washer enhances the stability of the end of the lead screw, ensuring that the lead screw maintains the correct position and direction during the telescopic process. The washer and fastening washer can serve as a buffer layer between the lead screw and the nut, reducing direct contact and friction, thereby reducing wear and extending the service life of the support rod. Through the fixation of the cushion block and fastening washer, the accuracy of the lead screw during movement within the outer sleeve can be ensured. The washer helps to disperse the pressure at the end of the lead screw, reducing the direct contact between the lead screw and the nut, thereby reducing wear. The fastening washer is riveted to the end of the lead screw to limit the cushion block and washer on the lead screw, ensuring the fixed position of the cushion block on the lead screw and preventing displacement during the operation of the support rod.

[0024] The above-mentioned electric tailgate support rod with a damper can be further set as follows: an electric motor sleeve and a central tube are provided inside the outer sleeve. The drive motor and the damper are installed in the electric motor sleeve. The central tube is sleeved on the outer peripheral surface of the lead screw, and a plurality of central key grooves parallel to the axis of the lead screw are circumferentially formed in the inner cavity. Splines corresponding to the central key grooves are provided on the outer peripheral surface of the nut. The load-bearing spring is sleeved on the outer peripheral surfaces of the guide sleeve and the central tube, and one end abuts against the damper, and the other end abuts against the outer sleeve.

[0025] With the above technical solutions, the design of the central tube provides additional support, ensuring the stable operation of the lead screw within the outer tube, reducing offset and wear. The design of the spline groove and spline provides mechanical locking between the lead screw and the nut, preventing relative rotation and thus ensuring the effective transmission of force. The setting of the load-bearing spring provides additional support, enhancing the load-bearing capacity of the strut system and enabling it to withstand greater loads. The design of the outer tube and the inner tube allows the inner tube to freely expand and contract within the outer tube, while providing the necessary support through the load-bearing spring, ensuring the flexibility and stability of the strut system. The motor sleeve provides an installation space for the drive motor and the damper, ensuring their stable operation and providing sufficient driving force and damping effect. The design of the motor sleeve and the central tube makes the entire strut structure more compact, reducing the occupied space, while improving the overall aesthetics and practicality. The synergistic effect of the motor sleeve and the central tube not only protects the internal drive motor and damper from external environmental interference but also ensures their efficient and stable operation, thereby improving the reliability and service life of the electric tailgate strut.

[0026] The beneficial effects of the present invention are as follows:

[0027] Through a series of elaborate designs and optimizations, the electric tailgate strut with a damper of the present invention brings the following remarkable beneficial effects:

[0028] 1. The damper of the present invention uses an O-ring or a sealing sleeve as the annular elastic friction element, which not only ensures the uniform distribution of the friction pressure, avoids the damping force fluctuation caused by local eccentric wear of the traditional split friction plates, but also adaptively compensates for the dimensional changes during long-term use through its elastic material properties, maintaining the stability of the contact pressure. In addition, through the modular design, the number of parts is simplified, the cost is reduced, and the assembly efficiency is improved.

[0029] 2. The present invention ensures the stability of the lubricating film in high-temperature and low-temperature environments through the fine selection of lubricating grease and lubrication design, preventing lubrication failure caused by grease volatilization or oil soap separation, thereby greatly reducing the wear amount of the annular elastic friction element. At the same time, the precise fit of the external spline part and the spline groove, as well as the physical locking of the snap ring and the limiting platform, realize the stable transmission and linkage of torque, eliminate the risk of loosening, and improve the stability of the damper during operation.

[0030] 3. The present invention completely solves the problem of unstable damping force caused by spring fatigue and friction plate eccentric wear in the traditional scheme through the two-way rigid limit and thread self-locking design, avoiding the displacement and inclination of the resistance-increasing block, and further improving the stability of the damper. In addition, the design of the motor sleeve and the central tube makes the entire strut structure more compact, beautiful and practical, improving the reliability and service life of the electric tailgate strut.

[0031] The present invention will be further described below in conjunction with the accompanying drawings. Description of the Drawings

[0032] Figure 1 It is a schematic cross-sectional view and a partial enlarged view of Embodiment 1 of the present invention.

[0033] Figure 2 It is an exploded view of Embodiment 1 of the present invention.

[0034] Figure 3 It is a three-dimensional schematic view of the damper of Embodiment 1 of the present invention.

[0035] Figure 4 It is a schematic structural view of the damper of Embodiment 1 of the present invention after removing the damper housing.

[0036] Figure 5 It is the explosion of the damper of Embodiment 1 of the present invention Figure 1 .

[0037] Figure 6 It is the explosion of the damper of Embodiment 1 of the present invention Figure 2 .

[0038] Figure 7 It is a schematic cross-sectional view of the damper of Embodiment 1 of the present invention.

[0039] Figure 8 It is a three-dimensional schematic view of Embodiment 1 of the present invention.

[0040] Figure 9 It is a force-displacement characteristic curve graph in the initial state after installing the damper in Embodiment 1 of the present invention.

[0041] Figure 10 It is a force-displacement characteristic curve graph after the damper in Embodiment 1 of the present invention has worked 1000 times.

[0042] Figure 11 It is a force-displacement characteristic curve graph after the damper in Embodiment 1 of the present invention has worked 3500 times.

[0043] Figure 12 It is a force-displacement characteristic curve graph after the damper in Embodiment 1 of the present invention has worked 7000 times.

[0044] Figure 13 It is a force-displacement characteristic curve graph after the damper in Embodiment 1 of the present invention has worked 10000 times.

[0045] Figure 14 It is a force-displacement characteristic curve graph after the damper in Embodiment 1 of the present invention has worked 20000 times.

[0046] Figure 15It is the force-displacement characteristic curve graph after the damper in Embodiment 1 of the present invention has worked 30,000 times.

[0047] Figure 16 It is a three-dimensional schematic diagram of the damper in Embodiment 2 of the present invention.

[0048] Figure 17 It is a structural schematic diagram of the damper in Embodiment 2 of the present invention after removing the damper housing.

[0049] Figure 18 It is the explosion Figure 1 .

[0050] Figure 19 It is the explosion Figure 2 .

[0051] Figure 20 It is a cross-sectional schematic diagram of the damper in Embodiment 2 of the present invention.

[0052] Figure 21 It is a three-dimensional schematic diagram of the damper in Embodiment 3 of the present invention.

[0053] Figure 22 It is a structural schematic diagram of the damper in Embodiment 3 of the present invention after removing the damper housing.

[0054] Figure 23 It is the explosion Figure 1 .

[0055] Figure 24 It is the explosion Figure 2 .

[0056] Figure 25 It is a cross-sectional schematic diagram of the damper in Embodiment 3 of the present invention.

[0057] Figure 26 It is a three-dimensional schematic diagram of the damper in Embodiment 4 of the present invention.

[0058] Figure 27 It is a structural schematic diagram of the damper in Embodiment 4 of the present invention after removing the damper housing.

[0059] Figure 28 It is the explosion Figure 1 .

[0060] Figure 29 It is the explosion Figure 2 .

[0061] Figure 30 It is a cross-sectional schematic diagram of the damper in Embodiment 4 of the present invention.

[0062] Label annotation:

[0063] 1. Damper housing; 2. Resistance increasing block; 3. Lead screw; 4. O-ring; 5. Bearing; 6. Limit nut; 7. Limit filling block; 8. Outer sleeve; 9. Load-bearing spring; 11. Annular limit platform; 12. Bearing limit groove; 13. First bearing snap ring; 21. Positioning groove; 22. Spline groove; 31. Outer spline part; 32. First annular groove; 33. Bearing positioning step; 34. Second bearing snap ring; 35. Second annular groove; 36. First resistance increasing snap ring; 37. Third annular groove; 38. Second resistance increasing snap ring; 41. Sealing sleeve; 61. Threaded part; 81. Driving motor; 82. Damper; 83. Motor sleeve; 84. Central tube; 91. Inner sleeve; 92. Guide sleeve; 93. Connecting component; 811. Spline; 841. Central keyway; 931. Nut; 932. Spacer block; 933. Washer; 934. Fastening gasket. Detailed implementation mode

[0064] As Figures 1 - 15As shown in the figure, an electric tailgate strut with a damper includes a fixed rod assembly, a moving rod assembly that moves axially relative to the fixed rod assembly to achieve telescopic movement, and a load-bearing spring 9. The fixed rod assembly includes an outer sleeve 8, a lead screw 3 rotatably arranged inside the outer sleeve 8, a drive motor 81, and a damper 82. The moving rod assembly includes an inner sleeve 91, a guide sleeve 92, and a coupling assembly 93. The outer sleeve 8 and the inner sleeve 91 are coaxially sleeved. The guide sleeve 92 is coaxially installed inside the inner sleeve 91. One end of the lead screw 3 is movably connected to the guide sleeve 92 through the coupling assembly 93, and the other end passes through the damper 82 and is connected to the output end of the drive motor 81. The coupling assembly 93 includes a nut 931 and a spacer 932. The nut 931 is connected to the lead screw 3 through a non-self-locking thread structure. Among them, the lead screw 3 is rotatably arranged in the outer sleeve 8 by electric drive or external drive, and the outer peripheral surface of the nut 931 is threadedly connected to the guide sleeve 92. The spacer 932 is installed at the end of the lead screw 3 and is located in the guide sleeve 92. Washers 933 and fastening washers 934 are respectively arranged at both ends of the lead screw 3 corresponding to the spacer 932. One end of the washer 933 abuts against the spacer 932, and the other end abuts against the nut 931. The fastening washer 934 is connected to the end of the lead screw 3 and is used to limit the spacer 932 and the washer 933 on the lead screw 3. Inside the outer sleeve 8, there are a motor sleeve 83 and a central tube 84. The drive motor 81 and the damper 82 are installed in the motor sleeve 83. The central tube 84 is sleeved on the outer peripheral surface of the lead screw 3, and a plurality of central key grooves 841 parallel to the axis of the lead screw 3 are circumferentially opened in the inner cavity. On the outer peripheral surface of the nut 931, there are splines 811 corresponding to the central key grooves 841. The load-bearing spring 9 is sleeved on the outer peripheral surfaces of the guide sleeve 92 and the central tube 84, and one end abuts against the damper 82, and the other end abuts against the end of the outer sleeve 8. Among them, there are at least four implementation modes of the damper 82 that can be used on this electric tailgate strut.

[0065] Embodiment 1: As Figures 3 - 8 shown, the damper 82 includes a damper housing 1 and a resistance increasing component installed inside the damper housing 1. The resistance increasing component includes a resistance increasing block 2 and a limiting mechanism;

[0066] On the outer peripheral surface of the resistance increasing block 2, there are two O-rings 4 made of fluororubber. The O-rings 4 are in close contact with the inner wall of the damper housing 1 and are attached with lubricating grease;

[0067] On the outer peripheral surface of the resistance increasing block 2, there are positioning grooves 21 for accommodating the O-rings 4. The O-rings 4 are arranged in the positioning grooves 21 and are in close contact with the inner wall of the damper housing 1;

[0068] One end of the lead screw 3 penetrates into the resistance increasing block 2 and is connected to the resistance increasing block 2 through a linkage structure;

[0069] The linkage structure includes an external spline portion 31 provided at one end of the lead screw 3 and a spline groove 22 provided on the inner wall of the resistance increasing block 2. The external spline portion 31 of the lead screw 3 penetrates into the spline groove 22 of the resistance increasing block 2 and is linked through spline fit;

[0070] An annular limiting platform 11 and a bearing 5 are provided inside the damper housing 1. A bearing limiting groove 12 is provided at the position corresponding to the bearing 5 on the damper housing 1. A first bearing snap ring 13 is clamped in the bearing limiting groove 12. Between the first bearing snap ring 13 and the annular limiting platform 11, it abuts against and limits the outer ring of the bearing 5. A first annular groove 32 and a bearing positioning step 33 are provided on the lead screw 3. A second bearing snap ring 34 is provided in the first annular groove 32. Between the second bearing snap ring 34 and the bearing positioning step 33, it abuts against and limits the inner ring of the bearing 5;

[0071] The limiting mechanism is used to limit the axial displacement of the resistance increasing block 2 in the damper housing 1;

[0072] The limiting mechanism includes a second annular groove 35 provided on the lead screw 3, a first resistance increasing snap ring 36 provided in the second annular groove 35, and a limiting nut 6 provided at one end of the damper housing 1 away from the first resistance increasing snap ring 36. The outer peripheral surface of the limiting nut 6 is provided with a threaded portion 61 threadedly connected to the inner wall of the damper housing 1. One end of the resistance increasing block 2 abuts against the limiting nut 6, and the other end abuts against the first resistance increasing snap ring 36, thereby connecting the resistance increasing block 2 to the lead screw 3 and restricting the radial displacement. Among them, the limiting nut 6 controls the contact pressure by adjusting the pre-tightening force;

[0073] Lubricating grease is filled between the two O-rings 4 and the inner wall of the damper housing 1. The evaporation rate of the lubricating grease is 2.5% (150 °C, 1 h, SH / T 0337), the steel mesh oil separation rate is 2.8% (100 °C, 30 h, SH / T 0324), the operating temperature range is -40 °C to 220 °C, the penetration is 255 (0.1 mm, GB / T 269), the NLGI grade is 2, the low-temperature torque (-40 °C): starting torque: 1250 mN·m, running torque: 600 mN·m (SH / T 0338), water spray loss: 1.2% (38 °C, 1 h, SH / T 0109). The elastic pressure of the two O-rings 4 and the interference fit with the inner wall of the damper housing 1 act together to generate a damping torque, which resists the non-driven rotational movement of the lead screw 3 and prevents the tailgate from accidentally falling. The damper 82 is installed inside the electric tailgate strut. When the tailgate is opened, the tailgate has a downward movement tendency under the action of gravity. At this time, since the drive motor 81 is powered off, the lead screw 3 loses the driving force. However, due to the action of the damper 82, the lead screw 3 will not immediately undergo non-driven rotation, but is resisted by the damping torque generated between the O-ring 4 and the inner wall of the damper housing 1. The magnitude of this damping torque can be controlled by adjusting parameters such as the material, size, pre-tightening force of the O-ring 4, and the viscosity of the lubricating grease to meet the damping requirements of different tailgate weights; when the tailgate needs to be closed, the drive motor 81 starts and drives the lead screw 3 to rotate through the output end. The rotation of the lead screw 3 is transmitted to the guide sleeve 92 through the coupling assembly 93, and then drives the inner sleeve 91 to move axially relative to the outer sleeve 8, realizing the telescopic movement of the electric tailgate strut. During this process, the resistance increasing block 2 rotates together with the lead screw 3, while the O-ring 4 slides on the inner wall of the damper housing 1, generating a certain frictional resistance. Since lubricating grease is filled between the O-ring 4 and the inner wall of the damper housing 1, the friction coefficient can be reduced, wear and high-temperature environment can be reduced, and at the same time, the stability and durability of the damping torque can be ensured. In addition, by setting the limiting mechanism, the axial displacement of the resistance increasing block 2 inside the damper housing 1 can be restricted to prevent it from being damaged or failing due to excessive movement. The limiting mechanism includes components such as the second annular groove 35, the first resistance increasing snap ring 36, and the limit nut 6 provided on the lead screw 3. They act together to confine the resistance increasing block 2 within a certain range inside the damper housing 1. When the damping torque needs to be adjusted, the pre-tightening force can be adjusted by rotating the limit nut 6, thereby changing the contact pressure between the O-ring 4 and the inner wall of the damper housing 1, and further achieving the purpose of adjusting the damping torque.

[0074] Such as Figures 9 - 15As shown in the figure, it is a curve graph of the force characteristic test report of the electric tailgate strut. The WQT-5000 tailgate strut testing machine is used to conduct force characteristic detection according to the QC / T207-1996 standard. The test speed is 300mm / min. Electric tailgate struts with the same specifications are tested respectively, and the force-displacement characteristic curve graphs of 0 times, 1000 times, 3500 times, 7000 times, 10000 times, 20000 times and 30000 times are taken respectively for analysis and comparison:

[0075] Test results:

[0076] Testing phase Dynamic internal resistance G (N) Change rate compared with the initial value Minimum stretching force F1 (N) Change rate compared with the initial value Initial (0 times) 556.0 - 385.0 - After 1000 times 557.0 +0.2% 356.0 -7.5% After 3500 times 581.0 +4.5% 334.0 -13.2% After 7000 times 526.0 -5.4% 368.0 -4.4% After 10000 times 585.0 +5.2% 327.0 -15.1% After 20000 times 577.0 +3.8% 317.0 -17.7% After 30000 times 558.0 +0.4% 327.0 -15.1%

[0077] Referring to the above table, after 30,000 tests, the dynamic internal resistance fluctuation is only ±5.4% (traditional solution ≥40%), the axial displacement error ≤0.1mm, verifying the long-term reliability of the collaborative design of the annular elastic friction element and lubricating grease. Among them, the total reduction of the minimum extension force F1 reaches 17.7% (after 20,000 times), and the friction coefficient is further reduced after the grease is run-in; the fluctuation of the maximum compression force F4 ≤0.62%, ensuring the smooth and safe closing of the tailgate. The grease steel mesh oil separation rate ≤3.0% (SH / T 0324), the water spray loss ≤1.5% (SH / T 0109), providing long-term lubrication for the support friction interface. The wear of the O-ring ≤0.05mm (after 30,000 times), and the service life is more than 3 times that of the traditional solution.

[0078] Through the interference fit of the annular elastic friction element and the anti-wear synergistic effect of the lubricating grease, the present invention solves the technical bottleneck of the traditional friction type solution with fast wear and large performance attenuation. The electric tailgate strut with the damper of the present invention has its initial dynamic internal resistance increased by 334%, with a significant damping effect. At the same time, the performance fluctuation ≤0.62% after 30,000 tests, and the service life is 3 times that of the traditional solution. The modular design is suitable for all scenarios: by replacing the O-ring size (tolerance ±0.1mm), the thickness of the sealing sleeve (±0.2mm) or the grease type (such as high and low temperature formulations), it can cover the needs of sedans, SUVs, commercial vehicles and new energy vehicle models.

[0079] Example 2: As Figures 16 - 20 shown, the damper 82 includes a damper housing 1 and a resistance increasing component installed in the damper housing 1. The resistance increasing component includes a resistance increasing block 2 and a limiting mechanism;

[0080] The outer peripheral surface of the resistance increasing block 2 is provided with a sealing sleeve 41 made of silica gel. The sealing sleeve 41 covers the outer peripheral surface of the resistance increasing block 2 and is in close contact with the inner wall of the damper housing 1 and is attached with lubricating grease;

[0081] One end of the lead screw 3 penetrates into the resistance increasing block 2 and is connected to the resistance increasing block 2 through a linkage structure;

[0082] The linkage structure includes an external spline portion 31 provided at one end of the lead screw 3 and a spline groove 22 provided on the inner wall of the resistance increasing block 2. The external spline portion 31 of the lead screw 3 penetrates into the spline groove 22 of the resistance increasing block 2 and is linked by spline fit;

[0083] An annular limiting platform 11 and a deep groove ball bearing 5 are provided inside the damper housing 1. A bearing limiting groove 12 is provided in the damper housing 1 corresponding to the deep groove ball bearing 5. A first bearing snap ring 13 is clamped in the bearing limiting groove 12. The outer ring of the deep groove ball bearing 5 is abutted and limited between the first bearing snap ring 13 and the annular limiting platform 11. A first annular groove 32 and a bearing positioning step 33 are provided on the lead screw 3. A second bearing snap ring 34 is provided in the first annular groove 32. The inner ring of the deep groove ball bearing 5 is abutted and limited between the second bearing snap ring 34 and the bearing positioning step 33;

[0084] The limiting mechanism is used to limit the axial displacement of the resistance increasing block 2 in the damper housing 1;

[0085] The limiting mechanism includes a second annular groove 35 and a third annular groove 37 provided on the lead screw 3, and a first resistance increasing snap ring 36 and a second resistance increasing snap ring 38 provided in the second annular groove 35 and the third annular groove 37. One end of the resistance increasing block 2 abuts against the first resistance increasing snap ring 36, and the other end abuts against the second resistance increasing snap ring 38 through a limiting filling block 7. The limiting filling block 7 is used to fill the gap remaining between the second annular groove 35 and the third annular groove 37 to prevent the resistance increasing block 2 from axially moving;

[0086] Lubricating grease is filled between the sealing sleeve 41 and the inner wall of the damper housing 1. Evaporation rate of the lubricating grease: 1.8% (150 °C, 1 h), steel mesh oil separation rate: 2.2% (100 °C, 30 h), service temperature range: -40 °C to 280 °C, penetration: 248 (NLGI2-3), NLGI grade: 2.5, low temperature torque (-40 °C): starting torque: 1150 mN·m, running torque: 580 mN·m, water spray loss: 0.9% (38 °C, 1 h). The elastic pressure of the sealing sleeve 41 and the inner wall of the damper housing 1 act together with an interference fit to generate a damping torque for resisting the non-driven rotation of the lead screw 3 and preventing the tailgate from accidentally falling.

[0087] Example 3: As Figures 21 - 25 shown, the damper includes a damper housing 1 and a resistance increasing component installed inside the damper housing 1. The resistance increasing component includes two resistance increasing blocks 2 and a limiting mechanism;

[0088] Two O-rings 4 made of fluororubber are provided on the outer peripheral surfaces of the two resistance increasing blocks 2. All four O-rings 4 are in close contact with the inner wall of the damper housing 1 and are attached with lubricating grease;

[0089] The outer peripheral surfaces of the resistance increasing blocks 2 are all provided with positioning grooves 21 for accommodating the O-ring 4. The O-rings 4 are arranged in pairs in the corresponding positioning grooves 21 and are in close contact with the inner wall of the damper housing 1;

[0090] One end of the lead screw 3 penetrates into the resistance increasing block 2 and is connected to the resistance increasing block 2 through a linkage structure;

[0091] The linkage structure includes an external spline portion 31 provided at one end of the lead screw 3 and a spline groove 22 provided on the inner wall of the resistance increasing block 2. The external spline portion 31 of the lead screw 3 penetrates into the spline groove 22 of the resistance increasing block 2 and is linked through spline fit;

[0092] An annular limiting platform 11 and a bearing 5 are arranged in the damper housing 1. A bearing limiting groove 12 is provided in the damper housing 1 corresponding to the bearing 5. A first bearing snap ring 13 is clamped in the bearing limiting groove 12. The outer ring of the bearing 5 abuts against and is limited between the first bearing snap ring 13 and the annular limiting platform 11. A first annular groove 32 and a bearing positioning step 33 are provided on the lead screw 3. A second bearing snap ring 34 is arranged in the first annular groove 32. The inner ring of the bearing 5 abuts against and is limited between the second bearing snap ring 34 and the bearing positioning step 33;

[0093] The limiting mechanism is used to limit the axial displacement of the resistance increasing block 2 in the damper housing 1;

[0094] The limiting mechanism includes a second annular groove 35 and a third annular groove 37 provided on the lead screw 3, and a first resistance increasing snap ring 36 and a second resistance increasing snap ring 38 arranged in the second annular groove 35 and the third annular groove 37. The two resistance increasing blocks 2 are inserted side by side into the external spline portion 31. One end abuts against the first resistance increasing snap ring 36, and the other end abuts against the second resistance increasing snap ring 38 through a limiting filling block 7. The limiting filling block 7 is used to fill the gap remaining between the second annular groove 35 and the third annular groove 37 to prevent the two resistance increasing blocks 2 from axially moving;

[0095] Lubricating grease is filled between the O-ring 4 and the inner wall of the damper housing 1. Evaporation rate of the lubricating grease: 1.5% (150 °C, 1 h), steel mesh oil separation rate: 1.9% (100 °C, 30 h), service temperature range: -30 °C to 250 °C, penetration: 260 (NLGI 3), NLGI grade: 3, low temperature torque (-40 °C): starting torque: 1300 mN·m, running torque: 650 mN·m, water spray loss: 0.7% (38 °C, 1 h). The elastic pressure of the four O-rings 4 and the inner wall of the damper housing 1 are in interference fit and act together to generate a damping torque to resist the non-driven rotational movement of the lead screw 3 and prevent the tailgate from accidentally falling

[0096] Example 4: As Figures 26 - 30As shown, the damper 82 includes a damper housing 1 and a resistance increasing component installed within the damper housing 1. The resistance increasing component includes a resistance increasing block 2 and a limiting mechanism;

[0097] Two O-rings 4 made of fluororubber are provided on the outer peripheral surface of the resistance increasing block 2. The O-rings 4 are in close contact with the inner wall of the damper housing 1 and are attached with lubricating grease;

[0098] A positioning groove 21 for accommodating the O-ring 4 is formed on the outer peripheral surface of the resistance increasing block 2. The O-ring 4 is arranged in the positioning groove 21 and is in close contact with the inner wall of the damper housing 1;

[0099] One end of the lead screw 3 penetrates into the resistance increasing block 2 and is connected to the resistance increasing block 2 through a linkage structure;

[0100] The linkage structure includes an external spline portion 31 provided at one end of the lead screw 3 and a spline groove 22 provided on the inner wall of the resistance increasing block 2. The external spline portion 31 of the lead screw 3 penetrates into the spline groove 22 of the resistance increasing block 2 and is linked through spline fit;

[0101] An annular limiting platform 11 and a bearing 5 are arranged within the damper housing 1. A bearing limiting groove 12 is provided on the damper housing 1 corresponding to the bearing 5. A first bearing snap ring 13 is clamped within the bearing limiting groove 12. Between the first bearing snap ring 13 and the annular limiting platform 11, the outer ring of the bearing 5 is abutted and limited. A first annular groove 32 and a bearing positioning step 33 are provided on the lead screw 3. A second bearing snap ring 34 is arranged within the first annular groove 32. Between the second bearing snap ring 34 and the bearing positioning step 33, the inner ring of the bearing 5 is abutted and limited;

[0102] The limiting mechanism is used to limit the axial displacement of the resistance increasing block 2 within the damper housing 1;

[0103] The limiting mechanism includes a second annular groove 35 and a third annular groove 37 provided on the lead screw 3, and a first resistance increasing snap ring 36 and a second resistance increasing snap ring 38 arranged within the second annular groove 35 and the third annular groove 37. The resistance increasing block 2 is inserted into the external spline portion 31. One end abuts against the first resistance increasing snap ring 36, and the other end abuts against the second resistance increasing snap ring 38 through a limiting filling block 7. The limiting filling block 7 is used to fill the remaining gap between the second annular groove 35 and the third annular groove 37 to prevent the axial movement of the resistance increasing block 2;

[0104] Lubricating grease is filled between the two O-rings 4 and the inner wall of the damper housing 1. Evaporation rate: 3.0% (150 °C, 1 h), steel mesh oil separation rate: 3.0% (100 °C, 30 h), operating temperature range: -50 °C to 180 °C, penetration: 245 (NLGI 2), NLGI grade: 2, low temperature torque (-50 °C): starting torque: 1100 mN·m, running torque: 540 mN·m, water spray loss: 1.5% (38 °C, 1 h). The elastic pressure of the two O-rings 4 and the interference fit with the inner wall of the damper housing 1 act together to generate a damping torque to resist the non-driven rotational movement of the lead screw 3 and prevent the tailgate from accidentally falling.

[0105] The damping torque of the damper of the present invention can be precisely adjusted by the following methods:

[0106] 1. Replace the material (hardness) of the annular elastic friction element: Select friction element materials with different elastic moduli (such as fluororubber μ≈1.2, silica gel μ≈0.8, hydrogenated nitrile rubber μ≈1.0), and change the friction force by adjusting the friction coefficient (±20%) to adapt to different damping requirements.

[0107] 2. Change the contact area between the annular elastic friction element and the housing:

[0108] 2.1. Adjust the element size: Replace O-rings with different cross-sectional diameters (such as increasing the diameter from 12 mm to 15 mm) or the thickness of the sealing sleeve (±0.2 mm);

[0109] 2.2. Adjust the covering range: Control the effective contact area by changing the covering length of the sealing sleeve (such as full-circumference covering or segmented covering);

[0110] 2.3. Adjust the depth of the positioning groove: The depth tolerance of the positioning groove for the resistance-increasing block is ±0.1 mm, indirectly controlling the radial deformation of the O-ring.

[0111] 3. Adjust the contact pressure between the annular elastic friction element and the housing:

[0112] 3.1. Adjust the pre-tightening force: Rotate the limit nut (Example 1) or replace the thickness of the limit filling block (±0.5 mm) to control the axial displacement of the resistance-increasing block, so that the contact pressure can be adjusted within the range of ±15%;

[0113] 3.2. Adjust the element diameter: Directly change the contact pressure by increasing or decreasing the O-ring diameter (tolerance ±0.1 mm) or the interference amount of the sealing sleeve (0.1 - 0.3 mm);

[0114] 3.3. Adjust the wall thickness of the housing: Adapt to damper housings with different wall thicknesses (tolerance ±0.05 mm) to match the contact pressure requirements.

[0115] 4. Replace the type of lubricating grease: The selected grease shall meet the following core parameters: viscosity 2000 - 5000 mPa·s, evaporation degree ≤ 3.0% (150 °C, SH / T 0337), steel mesh oil separation rate ≤ 3.0% (100 °C, SH / T 0324), service temperature -40 °C to 280 °C, penetration 245 - 260 (NLGI 2 - 3), low-temperature starting torque ≤ 1300 mN·m (-40 °C, SH / T 0338), water spray loss ≤ 1.5% (38 °C, SH / T 0109). For example, high-viscosity grease (4500 mPa·s) is suitable for heavy-duty / high-temperature scenarios (such as commercial vehicles) to enhance the lubricating film strength and inhibit oil film rupture; low-viscosity grease (2000 mPa·s) is suitable for extremely cold / high-frequency working conditions (such as new energy vehicles) to reduce friction resistance and improve smoothness. All greases are verified by the QC / T207 - 1996 standard to ensure long-term stability and precise damping control.

Claims

1. An electric tailgate strut with a damper, comprising a fixed rod assembly, a moving rod assembly that moves axially relative to the fixed rod assembly to achieve telescopic movement, and a bearing spring. The fixed rod assembly includes an outer sleeve, a lead screw rotatably arranged inside the outer sleeve, a drive motor, and a damper. The moving rod assembly includes an inner sleeve, a guide sleeve, and a coupling assembly. The outer sleeve and the inner sleeve are coaxially sleeved, the guide sleeve is coaxially installed inside the inner sleeve, one end of the lead screw is movably connected to the guide sleeve through the coupling assembly, and the other end passes through the damper and is connected to the output end of the drive motor. It is characterized in that: The damper includes a damper housing installed inside an outer casing and a resistance increasing component installed inside the damper housing. The resistance increasing component includes a plurality of resistance increasing blocks and a limiting mechanism. The outer peripheral surface of the resistance increasing block is provided with a plurality of annular elastic friction elements. The annular elastic friction elements are in interference fit with the inner wall of the damper housing. The limiting mechanism restricts the resistance increasing block inside the damper housing. One end of the lead screw penetrates into the resistance increasing block and is connected to the resistance increasing block through a linkage structure, and generates a damping torque against the non-driven rotation of the lead screw by friction with the inner wall of the damper housing. Lubricating grease is filled between the annular elastic friction element and the inner wall of the damper housing, and the lubricating grease adheres to the annular elastic friction element.

2. The electric tailgate strut with a damper according to claim 1, wherein: The annular elastic friction element is an O-ring. A positioning groove for accommodating the O-ring is formed on the outer peripheral surface of the resistance increasing block. The O-ring is arranged in the positioning groove and is in close contact with the inner wall of the damper housing.

3. The electric tailgate strut with a damper according to claim 1, characterized in that: The annular elastic friction element is a sealing sleeve. The sealing sleeve entirely or partially covers the outer peripheral surface of the resistance increasing block and is in close contact with the inner wall of the damper housing.

4. A power tailgate strut with a damper according to claim 1, characterized in that: The evaporation degree of the lubricating grease is ≤3.0%, the steel mesh oil separation rate is ≤3.0%, and the water spray loss is ≤1.5%.

5. A power tailgate strut with a damper according to any one of claims 1-4, characterized in that: The linkage structure includes an external spline portion provided at one end of the lead screw and a spline groove provided on the inner wall of the resistance increasing block. The external spline portion of the lead screw penetrates into the spline groove of the resistance increasing block for cooperative linkage.

6. A power tailgate strut with a damper according to any one of claims 1-4, characterized in that: An annular limiting platform and a bearing are arranged inside the damper housing. A bearing limiting groove is provided on the damper housing corresponding to the bearing. A first bearing snap ring is clamped in the bearing limiting groove. The outer ring of the bearing is abutted and limited between the first bearing snap ring and the annular limiting platform. A first annular groove and a bearing positioning step are provided on the lead screw. A second bearing snap ring is arranged in the first annular groove. The inner ring of the bearing is abutted and limited between the second bearing snap ring and the bearing positioning step, thereby axially restricting the lead screw inside the damper housing.

7. The electric tailgate strut with a damper according to claim 6, characterized in that: The limiting mechanism includes a second annular groove provided on the lead screw, a first resistance increasing snap ring arranged in the second annular groove, and a limiting nut arranged at one end of the damper housing away from the first resistance increasing snap ring. The outer peripheral surface of the limiting nut is provided with a threaded portion threadedly connected to the inner wall of the damper housing. One end of the resistance increasing block abuts against the limiting nut, and the other end abuts against the first resistance increasing snap ring.

8. The electric tailgate strut with a damper according to claim 6, wherein: The limiting mechanism includes a second annular groove and a third annular groove provided on the lead screw, and a first resistance increasing snap ring and a second resistance increasing snap ring arranged in the second annular groove and the third annular groove. One end of the resistance increasing block abuts against the first resistance increasing snap ring, and the other end abuts against the second resistance increasing snap ring. A limiting filling block is arranged between the resistance increasing block and the first resistance increasing snap ring and / or the second resistance increasing snap ring.

9. The electric tailgate strut with a damper according to claim 6, characterized in that: The coupling assembly includes a nut and a spacer block. The nut is connected to the lead screw through a non-self-locking thread structure. Wherein, the lead screw is rotatably arranged in the outer sleeve through electric drive or external driving force, and the outer peripheral surface of the nut is threadedly connected to the guide sleeve. The spacer block is installed at the end of the lead screw and is located in the guide sleeve. Washers and fastening washers are respectively arranged at both ends of the lead screw corresponding to the spacer block. One end of the washer abuts against the spacer block, and the other end abuts against the nut. The fastening washer is connected to the end of the lead screw and is used to limit the spacer block and the washer on the lead screw.

10. The electric tailgate strut with a damper according to claim 9, characterized in that: An inner side of the outer sleeve is provided with a motor sleeve and a central tube. The drive motor and the damper are installed in the motor sleeve. The central tube is sleeved on the outer peripheral surface of the lead screw, and a plurality of central key grooves parallel to the axis of the lead screw are circumferentially formed in the inner cavity. Splines corresponding to the central key grooves are provided on the outer peripheral surface of the nut. The load-bearing spring is sleeved on the outer peripheral surfaces of the guide sleeve and the central tube, and one end abuts against the damper, and the other end abuts against the outer sleeve.

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