Electric tail door supporting rod damper based on annular elastic friction element

Abstract

The utility model relates to an electric tail door stay bar damper based on annular elastic friction elements, which comprises a damper shell and a resistance-increasing component arranged in the damper shell, the resistance-increasing component comprises a plurality of resistance-increasing blocks, a screw rod and a limiting mechanism, a plurality of annular elastic friction elements are arranged on the peripheral surfaces of the resistance-increasing blocks, and the annular elastic friction elements are arranged on the peripheral surfaces of the resistance-increasing blocks. The annular elastic friction element is in interference fit with the inner wall of the damper shell, one end of the lead screw penetrates into the resistance increasing block and is connected with the resistance increasing block through the linkage structure, the limiting mechanism is used for limiting axial displacement of the resistance increasing block in the damper shell, and radial contact pressure is generated through elastic deformation of the annular elastic friction element. Compared with the prior art, the controllable damping torque is directly generated through elastic deformation of the annular elastic friction element, dependence on a traditional multi-piece type friction structure or a spring pre-tightening device is not needed, and the number of parts is greatly reduced.

Description

Technical Field

[0001] The utility model relates to the field of tailgate strut dampers, and particularly to an electric tailgate strut damper based on an annular elastic friction element. Background Art

[0002] In an automobile electric tailgate control system, a damper is a core component to ensure the 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 compression 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, and is matched with a compression spring and a spline assembly, resulting in a large number of parts and complicated assembly processes.

[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, the surface roughness is likely to increase due to wear, which in turn causes damping force attenuation, and frequent maintenance or replacement is required. In addition, the compression spring is prone to plastic deformation under long-term compression, which further aggravates the problem of unstable damping force and short service life. Summary of the Utility Model

[0005] The technical problem to be solved by the utility model is to provide an electric tailgate strut damper based on an annular elastic friction element for the deficiencies of the above prior art.

[0006] To achieve the above object, the utility model provides the following technical solution: An electric tailgate strut damper based on an annular elastic friction element, including a damper housing and a resistance increasing component installed in the damper housing, characterized in that:

[0007] The resistance increasing component includes a plurality of resistance increasing blocks, a lead screw and a limiting mechanism;

[0008] A plurality of annular elastic friction elements are arranged on the outer peripheral surface of the resistance increasing block, and the annular elastic friction elements are in interference fit with the inner wall of the damper housing;

[0009] One end of the lead screw penetrates into the resistance increasing block and is connected with the resistance increasing block through a linkage structure;

[0010] The limiting mechanism is used to limit the axial displacement of the resistance increasing block in the damper housing.

[0011] With the above technical solution, through the interference fit between the annular elastic friction element provided on the outer peripheral surface of the resistance increasing block and the inner wall of the damper housing, the elastic deformation of the annular elastic friction element generates a radial contact pressure, thereby generating a damping torque that resists the non-driven rotation of the lead screw by friction with the inner wall of the housing. The physical property of the interference fit enables the annular elastic friction element to maintain a stable frictional force relying on its own elastic deformation under the condition that no external pre-tightening force intervenes, 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 element and the inner wall of the housing is always in an interference state, avoiding the separation or eccentricity of the friction element 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 element 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 element makes the friction pressure distribution uniform, avoiding the damping force attenuation caused by local eccentric 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.

[0012] The above-mentioned electric tailgate strut damper based on an annular elastic friction element can be further set as follows: 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.

[0013] With the above technical solution, the lubricating grease adheres to the surface of the annular elastic friction element, which is used to reduce the dry friction wear of the friction pair, extend the service life of the annular elastic friction element by reducing the friction coefficient and inhibiting the oxidation of the surface of the annular elastic friction element, and achieve uniform distribution of the friction pressure. The elastic deformation characteristics of the annular elastic friction element 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.

[0014] The above-mentioned electric tailgate strut damper based on an annular elastic friction element can be further set as follows: the evaporation degree of the lubricating grease ≤ 3.0%, and the steel mesh oil separation rate ≤ 3.0%.

[0015] With the above technical solution, the evaporation degree of the lubricating grease is ≤ 3.0%, the steel mesh bleeding 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 operating 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 its low evaporation degree and low bleeding rate characteristics, avoiding lubrication failure caused by grease volatilization or oil-soap separation. Among them, the starting torque ≤ 1300 mN·m and the operating 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 local lubricating film rupture.

[0016] The above-mentioned electric tailgate strut damper based on an annular elastic friction element can be further set as: the annular elastic friction element is an O-ring, and a positioning groove for accommodating the O-ring is provided 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.

[0017] With the above technical solution, by providing a positioning groove on the outer peripheral surface of the resistance increasing block and accommodating the O-ring, a stable interference contact is formed between the O-ring and the inner wall of the damper housing through the elastic deformation of the O-ring. Among them, 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 traditional split friction plates. At the same time, the elastic material characteristics of the O-ring can adaptively compensate for the dimensional changes caused by wear or temperature changes 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 reducing costs and improving assembly efficiency. At the same time, the torsional damping amount can be conveniently adjusted by increasing or decreasing the depth of the positioning groove.

[0018] The above-mentioned electric tailgate strut damper based on an annular elastic friction element can also be set as: the annular elastic friction element is a sealing sleeve, and 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.

[0019] With the above technical solution, a sealing sleeve that wraps around the entire circumference or partially covers the outer peripheral surface of the resistance increasing block is used as an annular elastic friction element. By utilizing the elastic deformation characteristics of the sealing sleeve, a continuous and uniform interference fit is formed with the inner wall of the damper housing. The 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 wrapping structure of the sealing sleeve (such as an integral silicone sleeve or a segmented fluororubber sleeve) eliminates the splicing gaps of traditional split friction plates, ensures uniform circumferential distribution of the friction pressure, and avoids damping force fluctuations caused by poor local contact. The elastic modulus design of the sealing sleeve enables it to adaptively compensate for dimensional changes caused by temperature variations or long-term wear, maintaining the stability of the contact pressure. Moreover, the sealing sleeve and the resistance increasing block are fixed through in-mold forming or gluing, etc., to avoid abnormal wear caused by relative sliding. By replacing sealing sleeves with different thicknesses or materials, it can be modularly adapted to the requirements of sedans, SUVs, and commercial vehicles, greatly improving the versatility.

[0020] The above-mentioned electric tailgate strut damper based on an annular elastic friction element can be further configured as follows: 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.

[0021] 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. Torque transmission and linkage are achieved through the precise fit between the external spline portion and the spline groove, realizing stable linkage rotation and convenient axial installation.

[0022] The above-mentioned electric tailgate strut damper based on an annular elastic friction element can be further configured as follows: An annular limiting platform and a bearing are provided 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 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 provided on the lead screw. A second bearing snap ring is provided in the first annular groove. The inner ring of the bearing abuts and is limited between the second bearing snap ring and the bearing positioning step.

[0023] With the above technical solution, a bearing limit groove is provided at the position of the damper housing corresponding to the bearing. The first bearing snap ring is clamped in the bearing limit groove and jointly clamps the outer ring of the bearing with the annular limit 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. A first annular groove and a 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 relative sliding between the inner ring and 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 limit platform, the risk of loosening is completely eliminated, and at the same time, the problem of damping force attenuation caused by wear of the friction plate is avoided, improving the service life. At the same time, the axial displacement of the lead screw in the damper is avoided, improving the stability of the damper during operation, and the lead screw is also supported by the bearing to prevent the lead screw from shaking.

[0024] The above-mentioned electric tailgate strut damper based on a ring-shaped elastic friction element 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.

[0025] 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 the 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.

[0026] The above-mentioned electric tailgate strut damper based on a ring-shaped elastic friction element 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.

[0027] Adopting the above technical solution, by setting 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 to form a bidirectional axial constraint, thoroughly solving the problem of unstable damping force caused by spring fatigue and eccentric wear of the friction plate in the traditional solution, avoiding the displacement and inclination of the resistance-increasing block, and improving the stability of the damper.

[0028] The above-mentioned electric tailgate strut damper based on an annular elastic friction element can be further set as: a limiting filling block is arranged between the resistance-increasing block and the first resistance-increasing clamping ring and / or the second resistance-increasing clamping ring.

[0029] Adopting the above technical solution, by filling the assembly gap between the resistance-increasing block and the clamping ring, the axial movement allowance is eliminated, ensuring uniform distribution of the contact pressure, avoiding local stress concentration or eccentric wear caused by the gap, and replacing the traditional redundant adjustment structure with a modular filling block, solving the technical defects of eccentric wear of the friction pair, axial end play and low assembly efficiency. It is not necessary to use lead screws of multiple specifications, and the positioning and installation of the resistance-increasing block can be ensured through several fixed annular grooves and limiting filling blocks. At the same time, the clamp is arranged on the outer side of the damper housing for convenient installation and fixation.

[0030] The beneficial effects of the present utility model are as follows:

[0031] 1. Through the interference fit design of the annular elastic friction element, replacing the traditional friction plate, spring and multiple sets of gasket structures, the number of parts is greatly reduced, the assembly process is compressed from 15 steps to 5 steps, greatly improving the assembly efficiency and extending the service life of the equipment.

[0032] 2. The lubricating grease inhibits the dry friction between the annular elastic friction element and the inner wall of the housing through its low friction coefficient and antioxidant characteristics, greatly reducing the wear rate of the friction pair, and the grease loss, extending the service life.

[0033] 3. The limiting mechanism is manually adjusted without tools, and the modular design supports adapting to the needs of sedans, SUVs and commercial vehicles by replacing the thickness and contact area of the annular elastic friction element, the depth of the positioning groove or the type of grease, greatly improving the versatility of the product.

[0034] The present utility model will be further described below with reference to the accompanying drawings. Description of the Drawings

[0035] Figure 1 It is a three-dimensional schematic diagram of Embodiment 1 of the present utility model.

[0036] Figure 2 It is a structural schematic diagram of Embodiment 1 of the present utility model after removing the damper housing.

[0037] Figure 3The explosion of Embodiment 1 of the present utility model Figure 1 .

[0038] Figure 4 The explosion of Embodiment 1 of the present utility model Figure 2 .

[0039] Figure 5 The cross-sectional schematic diagram of Embodiment 1 of the present utility model.

[0040] Figure 6 The force-displacement characteristic curve diagram of Embodiment 1 of the present utility model in the initial state after installing the damper.

[0041] Figure 7 The force-displacement characteristic curve diagram of Embodiment 1 of the present utility model after the damper works 1000 times.

[0042] Figure 8 The force-displacement characteristic curve diagram of Embodiment 1 of the present utility model after the damper works 3500 times.

[0043] Figure 9 The force-displacement characteristic curve diagram of Embodiment 1 of the present utility model after the damper works 7000 times.

[0044] Figure 10 The force-displacement characteristic curve diagram of Embodiment 1 of the present utility model after the damper works 10000 times.

[0045] Figure 11 The force-displacement characteristic curve diagram of Embodiment 1 of the present utility model after the damper works 20000 times.

[0046] Figure 12 The force-displacement characteristic curve diagram of Embodiment 1 of the present utility model after the damper works 30000 times.

[0047] Figure 13 The three-dimensional schematic diagram of Embodiment 2 of the present utility model.

[0048] Figure 14 The structural schematic diagram of Embodiment 2 of the present utility model after removing the damper housing.

[0049] Figure 15 The explosion of Embodiment 2 of the present utility model Figure 1 .

[0050] Figure 16 The explosion of Embodiment 2 of the present utility model Figure 2 .

[0051] Figure 17 The cross-sectional schematic diagram of Embodiment 2 of the present utility model.

[0052] Figure 18Schematic perspective view of Embodiment 3 of the present utility model.

[0053] Figure 19 Schematic structural view of Embodiment 3 of the present utility model after removing the damper housing.

[0054] Figure 20 For Embodiment 3 of the present utility model, the explosion Figure 1 .

[0055] Figure 21 For Embodiment 3 of the present utility model, the explosion Figure 2 .

[0056] Figure 22 Schematic cross-sectional view of Embodiment 3 of the present utility model.

[0057] Figure 23 Schematic perspective view of Embodiment 4 of the present utility model.

[0058] Figure 24 Schematic structural view of Embodiment 4 of the present utility model after removing the damper housing.

[0059] Figure 25 For Embodiment 4 of the present utility model, the explosion Figure 1 .

[0060] Figure 26 For Embodiment 4 of the present utility model, the explosion Figure 2 .

[0061] Figure 27 Schematic cross-sectional view of Embodiment 4 of the present utility model.

[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; 11. Annular limit platform; 12. Bearing limit groove; 13. First bearing snap ring; 21. Positioning groove; 22. Spline groove; 31. External 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. Detailed implementation manners

[0064] Embodiment 1: As Figures 1 - 12 shown, an electric tailgate strut damper based on a ring-shaped elastic friction element 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, a lead screw 3 and a limiting mechanism;

[0065] The outer peripheral surface of the resistance increasing block 2 is provided with 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.

[0066] The outer peripheral surface of the resistance increasing block 2 is provided with a positioning groove 21 for accommodating the O-ring 4. 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] The limiting mechanism is used to limit the axial displacement of the resistance increasing block 2 in the damper housing 1.

[0071] The limiting mechanism includes a second annular groove 35 provided on the lead screw 3, a first resistance increasing snap ring 36 arranged in the second annular groove 35, and a limiting nut 6 arranged 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. The limiting nut 6 controls the contact pressure by adjusting the pre-tightening force.

[0072] 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 is 1250 mN·m, running torque is 600 mN·m (SH / T 0338), the water spray loss is 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 to resist the non-driven rotational movement of the lead screw 3 and prevent the tailgate from accidentally falling.

[0073] As Figures 6 - 13 shown, it is a curve graph of the force characteristic test report after the electric tailgate strut is installed in the damper of the present utility model. 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 300 mm / min, and the electric tailgate struts with the same specifications are respectively tested and compared with Figure 6 the electric tailgate strut without a damper. The force-displacement characteristic curve graphs of 0 times, 1000 times, 3500 times, 7000 times, 10000 times, 20000 times and 30000 times are respectively taken for analysis and comparison:

[0074] Test results:

[0075] Testing stage 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%

[0076] 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 ≤0.1 mm, verifying the long-term reliability of the collaborative design of the annular elastic friction element and the 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 maximum compression force F4 fluctuation ≤0.62%, ensuring the smooth and safe closing of the tailgate. The steel mesh oil separation rate of the lubricating grease ≤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 amount of the O-ring ≤0.05 mm (after 30,000 times), and the service life is more than 3 times that of the traditional solution.

[0077] Through the interference fit of the annular elastic friction element and the anti-wear synergistic effect of the lubricating grease, the utility model solves the technical bottleneck of fast wear and large performance attenuation of the traditional friction scheme. The initial dynamic internal resistance of the electric tailgate strut with the damper of the utility model is increased by 334%, and the damping effect is remarkable. At the same time, the performance fluctuation is ≤0.62% after 30,000 tests, and the service life is 3 times that of the traditional scheme. The modular design adapts to 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 covers the needs of sedans, SUVs, commercial vehicles and new energy vehicle models.

[0078] Embodiment 2: As Figures 13 - 17 shown, an electric tailgate strut damper based on an annular elastic friction element 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, a lead screw 3 and a limiting mechanism;

[0079] 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 is coated on 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;

[0080] One end of the lead screw 3 penetrates into the resistance increasing block 2 and is connected with the resistance increasing block 2 through a linkage structure;

[0081] 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;

[0082] An annular limiting platform 11 and a deep groove ball bearing 5 are arranged in 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 abuts 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 deep groove ball bearing 5 abuts and is limited between the second bearing snap ring 34 and the bearing positioning step 33;

[0083] The limiting mechanism is used to limit the axial displacement of the resistance increasing block 2 in the damper housing 1;

[0084] 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 clamping ring 36 and a second resistance-increasing clamping 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 clamping ring 36, and the other end abuts against the second resistance-increasing clamping ring 38 through a limiting filling block 7. The limiting filling block 7 is used to fill the gap between the second annular groove 35 and the third annular groove 37 to prevent the axial movement of the resistance-increasing block 2.

[0085] Lubricating grease is filled between the sealing sleeve 41 and the inner wall of the damper housing 1. The evaporation rate of the lubricating grease is 1.8% (150 °C, 1 h), the steel mesh oil separation rate is 2.2% (100 °C, 30 h), the operating temperature range is -40 °C to 280 °C, the penetration is 248 (NLGI2-3), the NLGI grade is 2.5, the low-temperature torque (-40 °C): starting torque is 1150 mN·m, the running torque is 580 mN·m, and the water spray loss is 0.9% (38 °C, 1 h). The elastic pressure of the sealing sleeve 41 and the inner wall of the damper housing 1 are in interference fit to generate a damping torque to resist the non-driven rotational movement of the lead screw 3 and prevent the tailgate from accidentally falling.

[0086] Example 3: As Figures 18 - 22 shown, an electric tailgate strut damper based on an annular elastic friction element includes a damper housing 1 and a resistance-increasing component installed in the damper housing 1. The resistance-increasing component includes two resistance-increasing blocks 2, a lead screw 3 and a limiting mechanism;

[0087] 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;

[0088] Positioning grooves 21 for accommodating the O-rings 4 are provided on the outer peripheral surfaces of the resistance-increasing blocks 2. 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;

[0089] 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;

[0090] 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;

[0091] Inside the damper housing 1, there is an annular limiting platform 11 and a bearing 5. At the position corresponding to the bearing 5 on the damper housing 1, there is a bearing limiting groove 12. 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. On the lead screw 3, there are a first annular groove 32 and a bearing positioning step 33. A second bearing snap ring 34 is arranged 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;

[0092] The limiting mechanism is used to limit the axial displacement of the resistance increasing block 2 in the damper housing 1;

[0093] The limiting mechanism includes a second annular groove 35 and a third annular groove 37 arranged 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 part 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 the 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 moving axially;

[0094] 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), operating 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 to jointly generate a damping torque to resist the non-driven rotational movement of the lead screw 3 and prevent the tailgate from falling accidentally.

[0095] Example 4: As Figures 23 - 27 shown, an electric tailgate strut damper based on an annular elastic friction element 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, a lead screw 3 and a limiting mechanism;

[0096] 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;

[0097] On the outer peripheral surface of the resistance increasing block 2, there is a positioning groove 21 for accommodating the O-ring 4. 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;

[0098] 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;

[0099] 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;

[0100] 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 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 and is limited between the second bearing snap ring 34 and the bearing positioning step 33;

[0101] The limiting mechanism is used to limit the axial displacement of the resistance increasing block 2 in the damper housing 1;

[0102] 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 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 gap remaining between the second annular groove 35 and the third annular groove 37 to prevent the resistance increasing block 2 from moving axially;

[0103] Lubricating grease is filled between the two O-rings 4 and the inner wall of the damper housing 1. Evaporation degree: 3.0% (150 °C, 1 h), steel mesh oil separation rate: 3.0% (100 °C, 30 h), service 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 inner wall of the damper housing 1 are in interference fit to jointly generate a damping torque to resist the non-driven rotational movement of the lead screw 3 and prevent the tailgate from falling accidentally.

[0104] The damping torque of the damper of the present utility model can be accurately adjusted by the following method:

[0105] 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 μ≈1.0), and change the frictional force by adjusting the friction coefficient (±20%) to adapt to different damping requirements.

[0106] 2. Change the contact area between the annular elastic friction element and the housing:

[0107] 2.1. Adjust the element size: Replace O-rings with different cross-sectional diameters (e.g., increase the diameter from 12 mm to 15 mm) or the thickness of the sealing sleeve (±0.2 mm);

[0108] 2.2. Adjust the covering range: Control the effective contact area by changing the covering length of the sealing sleeve (e.g., full-circumference covering or segmented covering);

[0109] 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.

[0110] 3. Adjust the contact pressure between the annular elastic friction element and the housing:

[0111] 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, adjusting the contact pressure within the range of ±15%;

[0112] 3.2. Adjust the element diameter: Directly change the contact pressure by increasing or decreasing the diameter of the O-ring (tolerance ±0.1 mm) or the interference amount of the sealing sleeve (0.1 - 0.3 mm);

[0113] 3.3. Adjust the wall thickness of the housing: Adapt the damping housing with different wall thicknesses (tolerance ±0.05 mm) to match the contact pressure requirements.

[0114] 4. Replace the type of lubricating grease: The selected grease needs to meet the following core parameters: viscosity 2000 - 5000 mPa·s, evaporation degree ≤ 3.0% (150 °C, SH / T 0337), steel wire 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-load / high-temperature scenarios (such as commercial vehicles) to enhance the lubricating film strength to inhibit oil film rupture; low-viscosity grease (2000 mPa·s) is adapted to 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 damper based on an annular elastic friction element, comprising a damper housing and a resistance increasing component installed in the damper housing, characterized in that: The resistance increasing component includes a plurality of resistance increasing blocks, a screw rod and a limiting mechanism; The outer peripheral surface of the resistance increasing block is provided with a plurality of annular elastic friction elements, and the annular elastic friction elements are interference fit with the inner wall of the damper housing; One end of the screw rod penetrates into the resistance increasing block and is connected to the resistance increasing block through a linkage structure; The limiting mechanism is used to limit the axial displacement of the resistance-increasing block in the damper housing.

2. The electric tailgate strut damper based on an annular elastic friction element according to claim 1, characterized in that: 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.

3. The electric tailgate strut damper based on an annular elastic friction element according to claim 2, characterized in that: The evaporation degree of the lubricating grease is ≤3.0%, and the oil separation rate of the steel mesh is ≤3.0%.

4. The electric tailgate strut damper based on an annular elastic friction element according to claim 2, characterized in that: The annular elastic friction element is an O-ring, and a positioning groove for accommodating the O-ring is provided 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.

5. The electric tailgate strut damper based on an annular elastic friction element according to claim 2, characterized in that: The annular elastic friction element is a sealing sleeve, which is fully or partially covered on the outer peripheral surface of the resistance-increasing block and is in close contact with the inner wall of the damper housing.

6. The electric tailgate strut damper based on an annular elastic friction element according to claim 2, characterized in that: The linkage structure comprises an external spline portion arranged at one end of the screw rod and a spline groove arranged on the inner wall of the resistance increasing block, and the external spline portion of the screw rod penetrates into the spline groove of the resistance increasing block to cooperate and link.

7. The electric tailgate strut damper based on an annular elastic friction element according to claim 2, characterized in that: An annular limit platform and a bearing are arranged in the damper housing, a bearing limit groove is arranged in the damper housing corresponding to the bearing, a first bearing retaining ring is clamped in the bearing limit groove, the first bearing retaining ring and the annular limit platform are abutted against the outer ring of the bearing for limiting position, a first annular groove and a bearing positioning step are arranged on the screw rod, a second bearing retaining ring is arranged in the first annular groove, the second bearing retaining ring and the bearing positioning step are abutted against the inner ring of the bearing for limiting position.

8. An electric tailgate strut damper based on an annular elastic friction element according to any one of claims 1 to 7, characterized in that: The limiting mechanism includes a second annular groove arranged on the screw rod, a first resistance-increasing clamping 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 clamping 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 is against the limiting nut, and the other end is against the first resistance-increasing clamping ring.

9. An electric tailgate strut damper based on an annular elastic friction element according to any one of claims 1 to 7, characterized in that: The limiting mechanism includes a second annular groove and a third annular groove arranged on the screw rod, and a first resistance-increasing clamping ring and a second resistance-increasing clamping ring arranged in the second annular groove and the third annular groove. One end of the resistance-increasing block is against the first resistance-increasing clamping ring, and the other end is against the second resistance-increasing clamping ring.

10. The electric tailgate strut damper based on an annular elastic friction element according to claim 9, characterized in that: A limiting filling block is provided between the resistance increasing block and the first resistance increasing clamping ring and / or the second resistance increasing clamping ring.

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