End protection structure of LED lamp strip and preparation method thereof

Abstract

The application relates to the technical field of LED lighting, and particularly provides an end protection structure of an LED lamp strip and a preparation method thereof. The protection structure comprises a hollow protection sleeve, the protection sleeve is arranged at the connection position of the LED lamp strip and a power line, the power line is arranged at the end of the LED lamp strip, the inner surface of the protection sleeve facing the LED lamp strip is provided with a groove, the groove extends to the edge of the protection sleeve close to one end of the LED lamp strip along the length direction of the LED lamp strip, and the groove is filled with sealing glue. The method comprises the following steps: S1, raw materials are injected into a mold to obtain the protection sleeve through pressure maintaining, cooling and demolding; S2, the protection sleeve is arranged at the connection position of the LED lamp strip and the power line; S3, sealing glue is injected from the end of the protection sleeve close to the LED lamp strip, so that the sealing glue is filled along the groove; and S4, the sealing glue is solidified to form a sealed connection. According to the application, the groove guides the uniform filling of the sealing glue, the shear load is dispersed through the deformation of the glue layer, and the sealing reliability is improved.

Description

Technical Field

[0001] This application relates to the field of LED lighting technology, and more specifically, to an end protection structure for an LED light strip and its preparation method. Background Technology

[0002] Flexible LED light strips are bendable and versatile, widely used in interior decoration, commercial lighting, and outdoor landscape lighting. During operation, the LED light strip needs to be connected to an external power supply via a power cord. However, the power connection area at the end of the strip has exposed conductive parts, low mechanical strength, and susceptibility to environmental influences. Therefore, protective sleeves are needed at the ends of the LED light strip to protect the ends and the power cord connection area from moisture, dust, and other external factors. These sleeves also mitigate the mechanical forces of pulling and bending during installation and use, ensuring long-term stable operation of the LED light strip.

[0003] Existing protective sleeves are installed on the ends of LED light strips, with sealant filled between the sleeve and the strip to improve the waterproof and sealing performance of the connection area. During installation, the protective sleeve is first placed on the end of the light strip, then a partial opening is created by prying open the side wall of the sleeve, and sealant is injected into the gap between the sleeve and the strip to form a sealed connection. However, the internal space after the protective sleeve is installed is small, and the injection area created by prying it open is limited. This makes it difficult for the sealant to evenly penetrate the entire contact area between the sleeve and the strip, resulting in problems such as insufficient sealant, uneven sealant thickness, or discontinuous sealing. This allows external moisture to enter the strip through the incompletely sealed areas, affecting the lifespan of the light strip. Meanwhile, the cured sealant, protective sleeve, and LED strip form a relatively fixed connection. When the power cord is pulled or bent and moves relative to the LED strip, the force is easily concentrated on the edge of the protective sleeve or the connection interface between the sealant and the LED strip and the protective sleeve due to the lack of effective buffer space in the connection area. This increases the local shear stress, and long-term cyclic stress can easily cause the sealant to crack, the protective sleeve to be fatigued and damaged, and the connection interface to detach, reducing the reliability of the LED strip end protective sleeve.

[0004] In summary, existing LED light strip end protective sleeves cannot meet actual needs. There is a need for a type of sleeve that can improve the uniformity of sealant filling, reduce shear stress caused by relative movement, and enhance the long-term reliability of LED light strip end protective sleeves. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the prior art by providing an end protection structure for an LED light strip. The protection structure includes a hollow protective sleeve, which is fitted onto the connection between the LED light strip and the power cord. The power cord is located at the end of the LED light strip. The protective sleeve has a groove on its inner surface facing the LED light strip. The groove extends along the length of the LED light strip to the edge of the protective sleeve near one end of the LED light strip, and the groove is filled with sealant.

[0006] The groove in this application alters the filling path and stress transfer method of the sealant, ultimately improving the reliability of the protective sleeve. Specifically, after the protective sleeve is fitted onto the connection between the LED strip and the power cord, sealant is injected into the sleeve from one end of the groove located at the edge, eliminating the need to pry the sleeve open from the side to create a local injection port. Under the injection pressure and the sealant's own flow, the sealant flows continuously into the sleeve along the length of the groove, further diffusing into the tiny gaps between the sleeve and the LED strip on both sides. This ensures that the internal areas, which are difficult to inject directly, are fully filled, and the sealant more evenly covers the contact area between the sleeve and the LED strip. This extends and blocks the path of external moisture migration into the strip, improving the sealing reliability of the connection area. Simultaneously, the groove increases the space between the sleeve and the LED strip for accommodating the sealant. The sealant filled in the groove forms a continuous elastic transition layer between the sleeve and the LED strip, absorbing the relative displacement between the strip and the power cord through its own shear deformation, transforming the load transfer from concentrated to distributed. When the power cord is subjected to pulling, bending, or other forces that cause relative movement between it and the LED light strip, the external force is first transmitted to the sealant layer. Utilizing the sealant's significant elastic deformation capacity, the relative displacement is gradually released through shear deformation of the sealant layer, reducing the direct concentration of force at the edge of the protective sleeve and the sealing interface, thus improving the reliability of the end protective sleeve. This application improves the long-term reliability of the LED light strip end protective sleeve from both sealing performance and mechanical cushioning perspectives.

[0007] Furthermore, the cross-sectional shape of the bottom of the groove is arc-shaped. The arc-shaped cross-section of the groove allows for a continuous curved transition between the bottom and sidewalls, reducing the obstruction of sealant flow caused by sharp corners. During the injection process, the sealant is less likely to form stagnant zones or residual air gaps at the corners of the groove bottom when flowing along the arc-shaped groove surface, facilitating continuous spreading and full filling of the groove. Simultaneously, after the sealant cures, when the power cord is stretched or bent, causing relative displacement between the LED strip and the protective sleeve, the sealant layer transfers the load through shear deformation. The arc-shaped cross-section allows the internal stress of the sealant layer to be gradually transferred and dispersed along the arc surface, reducing local stress concentration at the bottom of the groove and the edges of the sealant layer. This reduces sealant fatigue cracking and interface separation, improving the long-term sealing reliability of the end protective sleeve.

[0008] Furthermore, the grooves extend along a zigzag line on the inner surface of the protective sleeve. This extension increases the flow path of the sealant between the protective sleeve and the LED strip, creating a longer contact and constraint area between the sealant layer and both the protective sleeve and the LED strip, thus improving the stability of the sealed connection. The zigzag structure connects multiple groove segments in different directions sequentially. When the power cord is stretched or bent, causing relative displacement between the LED strip and the protective sleeve, the shear load borne by the sealant is decomposed in different groove segments and transmitted segment by segment in different directions. This reduces the degree of load concentration at a single straight interface, thereby reducing local shear stress and the tendency for the sealant layer to peel off.

[0009] Furthermore, a transition area is formed between the LED strip connector and the power cord connector of the protective sleeve. A small hole is provided on the end face of this transition area, communicating with a groove. This small hole in the transition area between the LED strip connector and the power cord connector creates a sealant injection space with an independent venting path. When sealant is injected into the groove, the sealant flows inward from one end of the LED strip, forming a directional flow path of front-end injection and end-end venting. This facilitates the sealant reaching the depth of the groove and the transition area, reducing dead zones. After curing, a more continuous sealant layer is formed between the LED strip connector and the power cord connector, reducing the possibility of moisture entering the connection area through local gaps and improving the sealing reliability of the end protective sleeve.

[0010] Furthermore, the transition area includes two opposing inclined walls, the distance between which gradually decreases towards the power cord socket. This creates a wedge-shaped space that gradually narrows along the power cord direction on both sides of the transition area. During the sealing process, the sealant enters from the LED strip socket side and gradually converges along the inclined walls towards the smaller power cord socket. The inclined walls provide continuous guidance for the sealant, preventing dead zones and air stagnation at the right-angle steps. As the distance between the two inclined walls gradually decreases, the sealant flow space gradually contracts, promoting further penetration of the sealant into the transition area and around the power cord, improving the continuity and sealing integrity of the sealant application between the LED strip socket and the power cord socket. During use, when the power cord is stretched or bent, the load is transferred from the smaller power cord socket to the larger light strip socket. The gradually increasing wedge-shaped transition area continuously expands the load-bearing cross-section and deformation area, causing the load concentrated at the connection boundary between the two parts to gradually disperse towards the light strip socket along the inclined wall. The filling sealant also gradually changes from thin to thick with the wedge-shaped space, absorbing relative displacement step by step through shear and elastic deformation in different areas, avoiding local stress concentration caused by abrupt changes in cross-section, thereby reducing the risk of fatigue cracking and interface separation of the protective sleeve and sealant layer, and improving the long-term reliability of the end connection.

[0011] Furthermore, connecting channels are provided between adjacent grooves, with the diameter of the connecting channels being smaller than the width of the grooves. These connecting channels create an interconnected adhesive flow network among the multiple independent grooves. During the adhesive injection process, as the sealant in one groove is pushed inward, the sealant can enter adjacent grooves through the connecting channels to replenish insufficiently filled areas. Simultaneously, compressed air within the groove can be transferred to other grooves or venting locations through the connecting channels, reducing localized air entrapment, air bubbles, and insufficient sealant, thus improving the uniformity of sealant filling in each groove. Furthermore, the diameter of the connecting channels is smaller than the width of the grooves, ensuring that the grooves still serve as the primary space for guiding and containing the sealant, while the connecting channels primarily function as lateral connections, pressure equalization, and sealant replenishment, preventing excessive sealant diversion along the lateral channels and thus avoiding weakening the directional filling along the length of the groove. After the sealant cures, the adhesive in the connecting channel can also connect the adhesive layers in adjacent grooves into a whole. When the power line is pulled, the shear load borne by the local adhesive layer is transmitted and dispersed to the adjacent adhesive layers through the finer connecting adhesive, so that multiple grooves share the relative displacement, reducing the local stress concentration of a single groove and its interface, thereby reducing sealant fatigue cracking and interface separation, and improving the long-term reliability of the end protective sleeve.

[0012] Furthermore, the elastic modulus of the sealant is lower than that of the protective sleeve. The sealant exhibits greater flexibility and elastic deformation capacity compared to the protective sleeve. When the power cord is stretched, bent, or experiences relative displacement with the LED strip, the low-modulus sealant located within the groove preferentially undergoes shear, tensile, and localized compressive deformation. This absorbs the relative displacement between the LED strip and the power cord within the sealant layer, preventing the load from being directly and concentratedly transmitted to the edge of the protective sleeve and the interface between the sealant and the LED strip. Instead, the load is gradually released through the sealant layer and dispersed over a larger area, reducing localized shear stress and peel stress, and improving the long-term reliability of the end protective sleeve.

[0013] Furthermore, the depth of the groove should be 0.2-0.6 times the wall thickness of the protective sleeve. When the groove depth is less than 0.2 times the wall thickness, the space for adhesive formed by the groove is small, the sealant layer is thin, and the adhesive's ability to conduct flow and absorb relative displacement through shear deformation is limited, making it difficult to fully utilize the groove's adhesive guiding and buffering functions. When the groove depth exceeds 0.6 times the wall thickness, the remaining wall thickness at the bottom of the groove is significantly reduced, which can easily reduce the local stiffness and tensile and bending resistance of the protective sleeve, making it prone to fatigue damage during installation, pulling, or bending.

[0014] This application also proposes a method for preparing an end protection structure for an LED light strip, the method comprising the following steps: S1. The raw material is injected into and fills the mold. After pressure holding and cooling, the mold is demolded, and then the burrs are removed and the surface is cleaned to obtain the protective sleeve. S2, Place the protective sleeve along the length of the LED strip at the connection between the LED strip and the power cord; S3, inject sealant from the end of the protective sleeve near the LED light strip. The sealant flows along the groove and fills the gap between the protective sleeve and the LED light strip. S4, the sealant filled in the groove is cured to form a sealed connection.

[0015] This application's preparation method sequentially combines protective sleeve molding, fitting, glue injection, and curing, allowing the protective sleeve to be directly used for LED strip end assembly immediately after injection molding. The overall process is continuous and facilitates mass production. Particularly in the glue injection step, a pre-formed groove on the inner surface of the protective sleeve serves as a flow path for the sealant. The sealant can flow continuously from the end near the LED strip along the groove inwards, further filling the gap between the protective sleeve and the LED strip. Compared to the traditional method of prying open the protective sleeve laterally and then injecting sealant locally, this reduces manual prying and the resulting localized deformation. It also improves the accessibility and uniformity of the sealant in the internal area, reducing the probability of insufficient sealant, air gaps, and uneven sealant thickness. Subsequently, curing allows the sealant to form a continuous, sealed connection with the protective sleeve and the LED strip, enabling the sealant layer within the groove to simultaneously provide sealing and cushioning. This application's method has simple process steps, good compatibility with existing injection molding and assembly processes, and improves the assembly efficiency of the end protective sleeve.

[0016] Furthermore, in step S3, before injecting the sealant, a squeezing pressure is applied to the area of ​​the corresponding groove of the protective sleeve near the power cord end, and the squeezing pressure is released after the sealant injection is completed. Applying squeezing pressure to the area of ​​the corresponding groove of the protective sleeve near the power cord end before injecting the sealant causes elastic compression in this area, thereby reducing the volume of the groove end and the surrounding gap, and expelling some of the air through the groove or a small hole connected to the groove. Then, the sealant is injected from the end near the LED strip, which reduces the probability of air trapped deep in the groove forming bubbles, cavities, or insufficient sealant. After the sealant injection is completed, the squeezing pressure is released, and the protective sleeve returns to its original shape under its own elasticity, causing the previously compressed groove and gap volume to increase again. This creates a suction and traction effect on the uncured sealant towards the groove end and the surrounding gap, prompting the sealant to spread further into the difficult-to-fill deeper areas and compensating for localized insufficient filling. Utilizing the protective sleeve's own elastic deformation to actively change the internal volume and pressure state is beneficial for expelling air, promoting deep filling of the sealant, improving the continuity and uniformity of the sealant layer, and thus improving the sealing reliability of the end protective sleeve.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The groove on the inner surface of the protective sleeve forms an open adhesive channel, allowing the sealant to flow inward along the groove and evenly fill the gap between the sealant and the LED strip, reducing insufficient sealant, uneven sealant layer, and local sealing defects. At the same time, a continuous elastic sealant layer is formed in the groove. When the power cord and the LED strip move relative to each other, the sealant absorbs the displacement through shear deformation, changing the load from local concentrated transmission to distributed buffer transmission, reducing the shear stress at the edge of the protective sleeve and the sealing interface, and improving the sealing reliability of the end protective sleeve.

[0018] (2) The groove extends along the length of the LED strip to the edge of the protective sleeve. During the installation process, the opening of the protective sleeve is more likely to expand elastically under the insertion force, which increases the instantaneous assembly space and reduces the insertion resistance of the LED strip. After installation, sealant can be injected directly from the groove opening without having to pry the protective sleeve open from the side to form an injection space, reducing operation steps and local excessive deformation, and reducing the risk of squeezing damage to the surface and internal circuitry of the LED strip.

[0019] (3) By fixing a protruding strip corresponding to the shape of the groove at the corresponding position of the existing molding die, the groove can be formed simultaneously during the raw material injection process, without the need for secondary processing such as cutting after demolding. Existing injection molding equipment and production processes such as pressure holding, cooling, and demolding can be directly adapted and modified. The scope of modification is small and the manufacturing steps are few, making it suitable for mass production on existing production lines. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of an end protection structure for an LED light strip provided in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the end face of the protective sleeve in the end protection structure of an LED light strip provided in Embodiment 1 of the present invention; Figure 3 A schematic diagram of the groove in the end protection structure of an LED light strip provided in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the connecting channel in the end protection structure of an LED light strip provided in Embodiment 2 of the present invention; Figure 5 This is a schematic diagram of a gradient transition protective sleeve in the end protection structure of an LED light strip provided in Embodiment 3 of the present invention; Figure 6 This is a schematic diagram of a method for preparing an end protection structure for an LED light strip according to Embodiment 4 of the present invention; Figure 7 This is a partial schematic diagram of the mold in step S1 of the method for preparing an end protection structure for an LED light strip provided in Embodiment 4 of the present invention.

[0021] Icons: 1-LED light strip; 2-Power cord; 3-Protective sleeve; 4-Groove; 5-Connecting channel. Detailed Implementation

[0022] To make the implementation process of this invention clearer, a detailed description will be provided below in conjunction with the accompanying drawings.

[0023] Example 1:

[0024] This application provides an end protection structure for an LED light strip, such as... Figure 1 As shown, the device includes an LED light strip 1, a power cord 2, and a protective sleeve 3. The LED light strip 1 includes a flexible substrate and multiple light-emitting elements disposed on the surface of the flexible substrate. The flexible substrate is made of flexible polyimide substrate or flexible polyvinyl chloride board, with a thickness of 0.2-0.8 mm and a width of 5-15 mm. The multiple light-emitting elements are spaced apart along the length of the flexible substrate. The power cord 2 is connected to the end of the LED light strip 1 and is used to provide power to the light-emitting elements.

[0025] A protective sleeve 3 is fitted over the connection area between the LED light strip 1 and the power cord 2 to protect the connection area. The protective sleeve 3 is made of an elastic insulating material, such as thermoplastic elastomer (TPE), polyvinyl chloride (PVC), or silicone rubber. In this embodiment, the protective sleeve 3 is made of TPE, which gives it a certain degree of elasticity, allowing it to expand elastically during installation and recover its deformation to fit the LED light strip 1 after installation.

[0026] The protective sleeve 3 includes a light strip socket, a power cord socket, and a transition area connecting the light strip socket and the power cord socket. The light strip socket has a flat, hollow structure, and its internal dimensions match the shape of the LED light strip 1; the power cord socket has a circular, hollow structure, and its internal dimensions match the outer diameter of the power cord 2. The light strip socket is 10-30mm long and 1-3mm thick; the power cord socket is 5-20mm long and 1-3mm thick.

[0027] like Figure 1 and Figure 2As shown, the protective sleeve 3 has a groove 4 on its inner surface facing the LED strip 1. Multiple inner surfaces of the protective sleeve 3 surrounding the outer periphery of the LED strip 1 also have grooves 4. The grooves 4 extend along the length of the LED strip 1 and penetrate to the edge of the protective sleeve 3 near the LED strip 1, forming an open channel for adhesive injection. The depth of the groove 4 is 0.2-0.6 times the wall thickness of the protective sleeve 3. In this embodiment, the wall thickness of the protective sleeve 3 is 2mm, providing sufficient space for adhesive in the groove 4 while maintaining a 1.4mm wall thickness to ensure the structural strength of the protective sleeve 3. Furthermore, the depth of the groove 4 gradually decreases from the end of the protective sleeve 3 near the LED strip 1 towards the power cord 2, with the initial depth being 0.5-0.6 times the wall thickness and the final depth being 0.2-0.3 times the wall thickness. The deeper areas in the initial stage of adhesive injection have a larger adhesive capacity and flow cross-section, which reduces flow resistance at the inlet. The layer gradually becomes shallower near the power line 2, allowing the adhesive to be subjected to increasing pressure as it propagates towards the end, guiding it to diffuse into the tiny gaps on both sides of the groove 4. After curing, a thicker adhesive layer forms near the light strip, providing greater shear deformation allowance, while the thinner adhesive layer near the power line 2 has stronger constraints, creating a gradual stress transfer path and reducing stress abrupt changes at the connection boundary.

[0028] The groove 4 has a width of 0.8-3mm, preferably 1.5mm; the extension length of the groove 4 along the length of the protective sleeve 3 is less than or equal to the length of the lamp strip splice. This ensures that the sealant covers the main stress area. The spacing between adjacent grooves 4 is 1-3 times the width of the groove 4, ensuring appropriate connection strength between multiple grooves 4 and forming a uniformly distributed sealant buffer area. The groove 4 has an arc-shaped cross-section with a radius of curvature of 0.5-3mm, creating a continuous and smooth transition between the bottom and sidewall of the groove 4, avoiding right-angle structures that would obstruct sealant flow and cause stress concentration. The arc-shaped groove 4 improves the flow continuity of the sealant during injection, making it easier for the sealant to spread along the bottom of the groove, while gradually transferring the shear load on the sealant along the arc-shaped interface, reducing local stress in the bottom area of ​​the groove.

[0029] The groove 4 extends in a zigzag pattern along the length of the LED strip 1 on the inner surface of the protective sleeve 3. Specifically, the groove 4 includes multiple sequentially connected inclined groove segments, with adjacent inclined groove segments forming an angle of 120°-170°. In this embodiment, the groove 4 consists of three inclined groove segments, with an angle of 150° between adjacent groove segments. The zigzag extension structure increases the flow path length of the sealant, creating a larger bonding area between the sealant and the protective sleeve 3. Simultaneously, it disperses the shear load generated when the power cord 2 is stretched in multiple directions, reducing stress concentration in a single area. Figure 3As shown, the transition between adjacent inclined groove segments is an arc, and the radius of the transition fillet can be set to 0.5-1.5 times the width of the groove 4. This retains the function of the zigzag groove 4 in changing the flow direction of the adhesive and extending the stress transmission path, while also preventing the adhesive from stagnating and trapping air at sharp corners. After the sealant cures, the arc transition also allows the shear stress to change continuously from one groove segment to another, reducing the likelihood of the zigzag corner itself becoming a new stress concentration point.

[0030] The groove 4 is filled with sealant, which is made of an elastic sealing material. In this embodiment, the sealant is room temperature vulcanizing silicone rubber (RTV silicone) with an elastic modulus of 0.5-5 MPa, and the protective sleeve 3 is made of TPE material with an elastic modulus of 10-100 MPa, so that the elastic modulus of the sealant is less than that of the protective sleeve 3. When the power cord 2 and the LED light strip 1 move relative to each other, the sealant can preferentially undergo shear deformation, absorb the relative displacement and disperse the load, and reduce the stress concentration at the edge of the protective sleeve 3 and the connection interface.

[0031] The protective sleeve 3 and the LED light strip 1 are sealed together using sealant. The sealant fills the groove 4 and the gap between the protective sleeve 3 and the LED light strip 1, creating a continuous sealing layer inside the protective sleeve 3 and improving the waterproof and dustproof performance of the protective structure. Simultaneously, the flexible deformation capability of the sealant enhances the tensile and bending resistance of the end structure.

[0032] Example 2:

[0033] Based on Embodiment 1, a transition area is provided between the LED strip connector and the power cord connector of the protective sleeve 3. The transition area is located at the end of the sealant flow direction along the groove 4. Multiple small holes are provided on the end face of the transition area, each hole communicating with a corresponding groove 4. In this embodiment, each groove 4 has a corresponding small hole, giving each groove 4 an independent venting path. The small hole is located at the end of the groove 4 near the power cord connector, i.e., at the end of the sealant flow path, allowing air pushed by the sealant during the injection process to preferentially move towards the end and be discharged through the small hole.

[0034] The orifice has a circular structure with a diameter of 0.3-1.0 mm, preferably 0.5 mm. The orifice diameter is smaller than the width of the groove 4, allowing it to primarily serve for air venting and pressure release, rather than becoming a main flow channel for the sealant. As the sealant flows along the groove 4, the air within the groove 4 is compressed and expelled through the orifice, reducing air stagnation and the formation of bubbles or cavities, thus improving the continuity of sealant filling. The axis of the orifice is inclined relative to the normal direction of the end face of the protective sleeve 3, with an inclination angle of 30°-60°. This inclined orifice allows for a smooth transition between the orifice and the groove 4, reducing air venting resistance and minimizing the impact of the through-hole on the structural strength of the transition area. Preferably, the orifice diameter is 0.6-1.0 mm at the end near the groove 4 and 0.3-0.6 mm at the end near the outside, forming a tapered vent that gradually narrows outwards. During sealant application, the larger inner inlet facilitates rapid airflow into the small hole at the end of the groove 4, reducing airflow resistance at the junction of the groove 4 and the small hole; the smaller outer inlet limits excessive sealant overflow. When the sealant reaches the vicinity of the small hole, the smaller outlet also creates a clear sealant-seeping point, allowing operators to determine if the groove 4 is essentially full, thus improving sealant application consistency. After sealant filling, the small hole is sealed either by filling with sealant or by using a flexible plug to prevent external moisture from entering the protective sleeve 3.

[0035] Furthermore, a connecting channel 5 is provided between adjacent grooves 4. The connecting channel 5 is located at one end of the groove 4 near the power cord socket and communicates with the adjacent groove 4, such as... Figure 4 As shown. The connecting channel 5 is located at the end of the sealant flow path, forming an interconnected venting network among the multiple grooves 4. During the sealant injection process, when air in a certain groove 4 cannot be directly discharged through the corresponding hole, it can enter the adjacent groove 4 through the connecting channel 5 and be discharged through the corresponding hole of the adjacent groove 4, thereby improving the overall venting capacity. The connecting channel 5 adopts a circular cross-section structure with a diameter of 0.2-0.8mm, and the diameter of the connecting channel 5 is less than 1 / 2 of the width of the groove 4. By setting the size of the connecting channel 5 to be smaller than the width of the groove 4, the groove 4 still serves as the main sealant filling space, while the connecting channel 5 mainly undertakes the functions of air circulation and pressure regulation, avoiding a large amount of sealant flowing through the connecting channel 5 and affecting the thickness of the sealant layer in the groove 4. Adjacent sets of connecting channels 5 are not located at the same cross-sectional position, but are staggered along the length of the LED light strip 1; this forms a multi-level rather than a single-level transverse connecting path between the grooves 4. During the injection process, if air in a certain area fails to be discharged through the first connecting channel 5, it can continue to move along the groove 4 and be transferred to other grooves 4 through the next connecting channel 5, thereby improving the air discharge tolerance. After curing, the misaligned adhesive bridge can also prevent multiple weak points from being concentrated in the same cross section, so that the stress is transferred to the adjacent adhesive layer step by step along the length direction, thereby improving the overall fatigue resistance.

[0036] The connecting channel 5 is inclined along the inner surface of the protective sleeve 3, with its axis forming an angle of 40°-50° with the length of the LED light strip 1. The inclined arrangement of the connecting channel 5 relative to adjacent grooves 4 allows the two ends of the connecting channel 5 to be located in different areas of the grooves 4, creating directional gas and adhesive transfer paths. During the adhesive injection process, as the sealant flows along the grooves 4 and compresses the internal air, a local pressure difference is generated on both sides of the connecting channel 5 at different locations, guiding the air from the high-pressure area to the adjacent grooves 4 and further expelling it through the vent. This makes the pressure distribution inside the grooves 4 more uniform, reduces local air retention, and improves the integrity of the sealant filling. Simultaneously, after the sealant cures, the inclined connecting channel 5 creates an oblique connection between the adhesive layers in adjacent grooves 4. When the power line 2 is stretched or bent, causing relative displacement, the local shear load can be gradually transferred to the adjacent adhesive layers along the inclined connection direction, changing the stress transmission path and preventing the load from concentrating on a single groove 4 area. This improves the overall deformation coordination of the sealant layer, reduces local shear stress, and enhances the reliability of the end protection structure.

[0037] Example 3:

[0038] Based on Example 1, the transition area structure of the protective sleeve 3 is improved by setting inclined walls to form a gradual transition area, such as... Figure 5 As shown, this design aims to improve the flow state of the sealant during the filling process and reduce stress concentration when the power cord 2 moves relative to the LED strip 1. A transition region is located between the strip socket and the power cord socket, with a length of 3-10 mm along the direction of the LED strip 1. The transition region includes a first inclined wall and a second inclined wall arranged opposite to each other, located on opposite sides of the transition region and extending along the length of the LED strip 1. A gradual space for accommodating the sealant is formed between the first and second inclined walls, and the distance between the two inclined walls gradually decreases towards the power cord socket.

[0039] The first and second inclined walls form an angle with the length of the LED strip 1, with the angle set at 25°-35°, creating a wedge-shaped space that gradually narrows from large to small in the transition area. During the adhesive injection process, after the sealant enters the transition area from the LED strip's connector side, the two inclined walls guide the flow direction of the sealant, causing it to propagate along the gradually narrowing space towards the power cord connector. Figure 5As shown by the blue arrows in the diagram. Compared to a right-angle transition structure, the inclined walls reduce the sudden narrowing of the flow cross-section, making the resistance change of the adhesive more gradual. This reduces the possibility of adhesive stagnation, backflow, or local cavities in the transition area, allowing the sealant to fill the transition area more fully and improving the continuity of the sealing layer inside the protective structure. Simultaneously, the gradual space formed by the two inclined walls causes the sealant layer thickness to gradually change from the LED strip socket towards the power cord socket. In use, when the power cord 2 is subjected to pulling or bending and moves relative to the LED strip 1, due to the small size of the power cord socket, the load is easily concentrated and transferred to the connection area between the power cord socket and the LED strip socket. By setting the inclined walls, a transition structure that gradually expands from a small cross-section to a large cross-section is formed, gradually increasing the load-bearing area of ​​the sealant layer and the protective sleeve 3. This allows the force to gradually diffuse along the inclined direction, rather than being concentrated on a single connection interface, such as... Figure 5 As indicated by the orange arrow in the middle.

[0040] Furthermore, the wedge-shaped spaces formed on both sides of the inclined wall allow the sealant to have different thicknesses at different locations. The space near the power cord socket is smaller, resulting in a thinner sealant layer, which helps maintain the constraint of the connection area; the space near the LED strip socket is larger, allowing for a thicker sealant layer and providing greater space for shear deformation. When the power cord 2 undergoes relative displacement, the sealant in the thicker area first undergoes elastic shear deformation and gradually transfers the deformation to the thinner area, allowing stress to be gradually released along the transition area, reducing the local shear stress at the interface between the sealant and the LED strip 1 and the protective sleeve 3. In other words, the transition area achieves a gradual change in the sealant filling path and the mechanical load transfer path, transforming the load transfer method from localized abrupt transmission to gradual dispersion along the transition area. This improves the integrity of the sealant filling while reducing stress concentration during repeated pulling and bending of the power cord 2, thus enhancing the fatigue resistance and long-term reliability of the end protection structure.

[0041] Example 4:

[0042] This application also proposes a method for preparing an end protection structure for an LED light strip, such as... Figure 6 As shown, the method includes the following steps: S1. The raw material is injected into and fills the mold. After pressure holding and cooling, the mold is demolded, and then the burrs are removed and the surface is cleaned to obtain the protective sleeve 3.

[0043] The elastic material raw material for preparing the protective sleeve 3 is injected into the cavity of the mold for forming the protective sleeve 3, allowing the molten material to flow fully within the cavity and fill the entire cavity space. After holding pressure and cooling, the mold is demolded to obtain the preliminarily formed protective sleeve 3. The elastic material is an insulating material such as TPE, PVC, or silicone rubber. In this embodiment, TPE is used. The injection temperature is 180-230℃, the holding pressure time is 5-20s, and the cooling time is 10-60s.

[0044] During the molding process, a raised structure is provided in the mold cavity corresponding to the groove 4 on the inner surface of the protective sleeve 3, so that the inner surface of the molded protective sleeve 3 forms the groove 4. The groove 4 extends along the length of the protective sleeve 3 and extends to the edge of the protective sleeve 3 near the LED light strip 1. The protective sleeve 3 with the groove 4 structure can be formed by one injection molding, without the need for subsequent secondary processing such as cutting and milling. After demolding, the burrs at the parting surface, gate and edges of the protective sleeve 3 are removed with a trimming knife, and the local protrusions are simply trimmed; then, the surface of the protective sleeve 3 and the inside of the groove 4 are wiped with a lint-free cloth dipped in an appropriate amount of isopropyl alcohol or anhydrous ethanol to remove mold release agent, dust and residual debris, and then air-dry at room temperature or blow-dry with low-pressure clean air to keep the surface of the protective sleeve 3 clean and dry, so as to avoid residues affecting the flow, wetting and adhesion of the subsequent sealant.

[0045] S2, the protective sleeve 3 is placed along the length of the LED light strip 1 at the connection between the LED light strip 1 and the power cord 2.

[0046] The molded protective sleeve 3 is fitted along the length of the LED strip 1 at the connection point between the LED strip 1 and the power cord 2, ensuring that the strip connection area inside the protective sleeve 3 covers the end of the LED strip 1, and the power cord connection area covers the outside of the power cord 2. During fitting, the groove 4 on the inner surface of the protective sleeve 3 is oriented towards the LED strip 1, and the groove 4 is kept open to the side extending to the end of the LED strip 1, allowing the sealant to enter from the end of the groove 4. Because the protective sleeve 3 is made of elastic material, it can expand and deform during fitting, allowing the LED strip 1 to smoothly enter the protective sleeve 3. After fitting, the protective sleeve 3 returns to its elastic deformation, maintaining a close fit with the LED strip 1 and the power cord 2. After fitting, the position of the protective sleeve 3 is adjusted to ensure that the end of the LED strip 1, the connection area of ​​the power cord 2, and the protective sleeve 3 are coaxial or corresponding, preventing uneven sealant filling due to installation misalignment.

[0047] S3, inject sealant into the end of the protective sleeve 3 near the LED light strip 1. The sealant flows along the groove 4 and fills the gap between the protective sleeve 3 and the LED light strip 1.

[0048] Liquid sealant is injected into the protective sleeve 3 through the opening of the groove 4 near the LED strip 1, allowing the sealant to flow along the length of the groove 4 and fill the gap between the protective sleeve 3 and the LED strip 1. The sealant is an elastic insulating sealing material, such as RTV silicone, polyurethane sealant, or modified silane sealant. In this embodiment, RTV silicone is used, and the injection viscosity is controlled at 1000-10000 mPa·s to ensure good fluidity of the sealant within the groove 4 while preventing excessive flow that could cause overflow.

[0049] During the adhesive injection process, the sealant first enters the groove 4 and propels into the protective sleeve 3 along the flow path formed by the groove 4. Then, under pressure, it spreads to both sides of the groove 4, filling the tiny gap between the protective sleeve 3 and the LED strip 1. The groove 4 serves as a continuous adhesive channel, allowing the sealant to cover areas difficult to reach with traditional lateral adhesive injection, improving filling uniformity. The amount of sealant injected is controlled according to the internal space of the protective sleeve 3, ensuring that the sealant completely fills the groove 4 and the gap between the protective sleeve 3 and the LED strip 1, while preventing excessive sealant from overflowing from the end of the protective sleeve 3.

[0050] S4, the sealant filled in the groove 4 is cured to form a sealed connection.

[0051] The sealant filling the groove 4 and the space between the protective sleeve 3 and the LED strip 1 is cured, transforming the sealant from a liquid state into an elastic solid sealing layer, forming a stable connection with the protective sleeve 3 and the LED strip 1. In this embodiment, room temperature curing is used, with a curing temperature of 20-30℃ and a curing time of 12-48 hours. Alternatively, depending on the sealant material, a heat curing method can be used, for example, curing at 40-80℃ for 1-4 hours to improve production efficiency. The cured sealant fills the interior of the groove 4, forming a continuous elastic connection layer. Because the elastic modulus of the sealant is lower than that of the protective sleeve 3 material, when the LED strip 1 and the power cord 2 are subjected to tension or bending, causing relative movement, the sealant can absorb the displacement through its own shear deformation, reducing stress concentration in the connection area while maintaining a sealed state between the protective sleeve 3 and the LED strip 1. The preparation method of this application is simple and suitable for mass production.

[0052] This application does not require the re-fabrication of the entire protective sleeve molding die; instead, it allows for partial modification of existing molds. The modified portion of the mold is as follows: Figure 7As shown. Specifically, firstly, the corresponding area in the existing mold cavity used to form the inner surface of the protective sleeve 3 is cleaned and positioned. Based on the position, width, depth, and extension shape of the groove 4, a matching metal protrusion is machined. The protrusion is preferably made of mold steel similar to the mold. Then, the protrusion is placed in the corresponding position of the cavity, and local spot welding or intermittent welding is performed along both sides of the protrusion using adhesion or laser welding methods to stably fix the protrusion to the inner wall of the mold. After welding, the weld seam and the edges of the protrusion are ground and polished to create a smooth transition between the protrusion and the original mold inner wall, avoiding burrs, material accumulation, or demolding obstacles during injection molding. After the above modifications are completed, the existing injection molding equipment and processes such as injection, pressure holding, cooling, and demolding can be used to directly form the corresponding groove 4 integrally on the inner surface of the protective sleeve 3 during molding. Therefore, only local additive manufacturing modification of the existing mold cavity is required, without redesigning and manufacturing the entire mold. The changes to the existing production equipment and process are minimal, and the modification cost is low. At the same time, the groove 4 can be formed in one piece with the protective sleeve 3, which helps to ensure the consistency of the position and size of the groove 4, making it suitable for mass production on existing production lines.

[0053] Further, in step S3, before injecting the sealant, a squeezing pressure is applied to the area of ​​the corresponding groove 4 of the protective sleeve 3 near the power line 2. The squeezing pressure is released after the sealant is injected. Specifically, before injecting the sealant, a ring clamp or multiple elastic pressure blocks evenly distributed around the circumference of the protective sleeve 3 are used to apply a circumferential squeezing pressure from the outside to the inside to the area of ​​the corresponding groove 4 of the protective sleeve 3 near the power line 2. This causes the area to elastically contract inward, reducing the volume of the gap at the end of the groove 4 and between the protective sleeve 3 and the LED light strip 1. The air in the gap is compressed and moves along the groove 4 and the connecting channel 5 to the small hole in the transition area, and is discharged through the small hole that remains open. After the squeezing continues until there is basically no obvious air discharge at the small hole, a flexible plug or a removable seal is used to close the small hole, and the protective sleeve 3 is kept under pressure. Then, the injection nozzle is attached to the opening of the groove 4 of the protective sleeve 3 near the LED light strip 1 and an appropriate amount of liquid sealant is injected to keep the inlet area of ​​the groove 4 covered with sealant. The circumferential squeezing pressure is then gradually released. As the protective sleeve 3 recovers its original shape through its own elasticity, the volume of the previously compressed groove 4 and its internal gaps increases. With the small holes already sealed and the inlets of the grooves 4 covered by sealant, the internal pressure decreases, creating a pressure difference relative to the outside. This draws the sealant at the inlet of the groove 4 towards the power cord 2 side along the groove 4, and promotes the sealant to further penetrate the depth of the groove 4, the connecting channel 5, and the tiny gap between the protective sleeve 3 and the LED strip 1, thus achieving active sealant replenishment and deep filling. After the protective sleeve 3 returns to its natural state and the sealant is fully filled, the small holes can remain sealed and the sealant can continue to cure. Using circumferential uniform extrusion instead of unilateral extrusion allows the protective sleeve 3 to shrink its internal volume more evenly along the circumference, avoiding local folding or tilting. This allows air to be expelled synchronously from the ends of each groove 4, and creates a more uniform recovery suction force after the pressure is released, thereby reducing air bubbles and localized sealant gaps, and improving the integrity and consistency of the sealant filling.

[0054] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An end protection structure for an LED light strip, the protection structure comprising a hollow protective sleeve, the protective sleeve being fitted onto the connection point between the LED light strip and a power cord, the power cord being disposed at the end of the LED light strip, characterized in that: The protective sleeve has a groove on its inner surface facing the LED light strip. The groove extends along the length of the LED light strip to the edge of the protective sleeve near one end of the LED light strip, and the groove is filled with sealant.

2. The end protection structure of the LED light strip according to claim 1, characterized in that: The bottom of the groove has an arc-shaped cross-section.

3. The end protection structure of the LED light strip according to claim 2, characterized in that: The groove extends along a fold line on the inner surface of the protective sleeve.

4. The end protection structure of the LED light strip according to claim 3, characterized in that: A transition area is formed between the LED strip connector and the power cord connector of the protective sleeve. A small hole is provided on the end face of the transition area, and the small hole communicates with the groove.

5. The end protection structure of the LED light strip according to claim 4, characterized in that: The transition area includes two inclined walls arranged opposite each other, and the distance between the two inclined walls gradually decreases in the direction close to the power line socket.

6. The end protection structure of the LED light strip according to any one of claims 1-5, characterized in that: A connecting channel is provided between adjacent grooves, and the diameter of the connecting channel is smaller than the width of the groove.

7. The end protection structure of the LED light strip according to claim 1, characterized in that: The elastic modulus of the sealant is less than that of the protective sleeve.

8. The end protection structure of the LED light strip according to claim 1, characterized in that: The depth of the groove is 0.2-0.6 times the wall thickness of the protective sleeve.

9. A method for preparing an end protection structure for an LED light strip, characterized in that, The method includes the following steps: S1. The raw material is injected into and fills the mold. After pressure holding and cooling, the mold is demolded, and then the burrs are removed and the surface is cleaned to obtain the protective sleeve. S2, the protective sleeve is fitted along the length of the LED light strip at the connection between the LED light strip and the power cord; S3, inject sealant from the end of the protective sleeve near the LED light strip, the sealant flows along the groove and fills the gap between the protective sleeve and the LED light strip; S4, the sealant filled in the groove is cured to form a sealed connection.

10. The method for preparing the end protection structure of the LED light strip according to claim 9, characterized in that: In step S3, before injecting the sealant, a squeezing force is applied to the area of ​​the protective sleeve corresponding to the groove near the end of the power cord, and the squeezing force is released after the sealant is injected.

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