Chin strap assembly, chin strap assembly manufacturing method and safety helmet

Abstract

The invention is applicable to the technical field of safety helmets, and provides a chin strap assembly, a chin strap assembly manufacturing method and a safety helmet, the chin strap assembly comprises two fixing straps; the two buckle belts are respectively wound on the corresponding fixing belts; each helmet hoop connecting piece is integrally connected with the tail end of the corresponding fixing band through an insert injection molding process, and a connecting structure used for being connected with a helmet hoop of the safety helmet in a matched mode is arranged on each helmet hoop connecting piece; each buckling buckle is integrally connected with the corresponding buckling belt and the tail end of the buckling belt surrounding the fixing belt through an insert injection molding process; the buckle system comprises a male buckle and a female buckle which are matched with each other, the tail end of one buckle belt is integrally connected with the female buckle through an insert injection molding process, and the other buckle belt is arranged in the male buckle in a penetrating mode. The chin strap solves the problems that an existing chin strap is low in connecting strength, poor in durability and complex in process.

Description

Technical Field

[0001] The present invention relates to the technical field of safety helmets, and particularly to a chin strap assembly, a manufacturing method of the chin strap assembly, and a safety helmet. Background Art

[0002] A safety helmet is an essential personal protective equipment in high-risk workplaces such as industrial production and construction. It is used to protect the head from falling objects, impacts, etc. The structure of a safety helmet mainly includes a helmet shell, a helmet liner, etc. The helmet liner includes a top strap, a cap band, and a chin strap. As an important component, the chin strap plays a role in assisting in fixing the safety helmet. By fastening it under the chin, it maintains the stability and correct position of the safety helmet, preventing the safety helmet from falling off due to shaking, collision, or changes in head posture during work, thereby ensuring continuous and effective protection of the head.

[0003] Currently, the common connection method between the chin strap and the buckle of a safety helmet on the market generally adopts a stitching connection. Specifically, the webbing of the chin strap is passed through the holes or connectors on the buckle, and then the webbing and the buckle are fixed together using a sewing machine or other stitching equipment with stitches. Although this stitching connection method can meet the fixing requirements of the chin strap to a certain extent, it has the following obvious defects:

[0004] Insufficient connection strength and easy to fail: The strength of the stitching connection mainly depends on the material of the stitches and the stitching process. However, the stitches themselves are prone to wear, aging, corrosion, etc. during long-term use, especially in harsh working environments. In addition, when the safety helmet is subjected to a large external force impact or pulling, the stitching part is likely to become a weak link, resulting in breakage or thread shedding, causing the chin strap to separate from the buckle, making the safety helmet lose its fixing function and unable to effectively protect the user's head safety.

[0005] Many thread ends, affecting aesthetics and comfort: The stitching connection inevitably generates thread ends. These thread ends not only affect the overall aesthetics of the safety helmet but may also come into contact with the skin during wearing, causing frictional discomfort, and even scratching the skin in extreme cases. Moreover, the gaps are also prone to dirt accumulation and are not easy to clean.

[0006] Low production efficiency and high cost: The stitching connection process is relatively cumbersome and requires special sewing equipment and skilled operators. Even when using automated sewing equipment, operations such as threading, adjustment, and positioning are still required, resulting in relatively low production efficiency. In addition, the stitching process also consumes additional materials such as stitches, increasing the production cost. At the same time, it is difficult to ensure the quality consistency of manual stitching, which may also lead to an increase in the defective rate of products.

[0007] In summary, the existing stitching connection method between the chin strap and the buckle of the safety helmet has deficiencies in terms of connection strength, reliability, aesthetics, production efficiency, and production cost. There is an urgent need for a new connection structure to overcome these defects, improve the overall performance and safety of the safety helmet, and reduce production costs and improve efficiency. Summary of the Invention

[0008] Based on this, the object of the present invention is to provide a chin strap assembly, a manufacturing method of the chin strap assembly, and a safety helmet, so as to fundamentally solve the problems of low connection strength, poor durability, and complex process of the existing chin strap.

[0009] A chin strap assembly according to an embodiment of the present invention, applied to a safety helmet, includes:

[0010] Two fixing straps;

[0011] Two buckle straps, each of which is respectively wound around the corresponding fixing strap;

[0012] Two cap hoop connectors, each of which is integrally connected to the end of the corresponding fixing strap through insert molding technology, and a connection structure for cooperating with the cap hoop of the safety helmet is provided on the cap hoop connector;

[0013] Two snap fasteners, each of which is integrally connected to the corresponding buckle strap and the end of the buckle strap wound around the fixing strap through insert molding technology;

[0014] And a snap fastener system, including a male buckle and a female buckle that cooperate with each other, wherein the end of one of the buckle straps is integrally connected to the female buckle through insert molding technology, and the other buckle strap is inserted into the male buckle.

[0015] In addition, a chin strap assembly according to the above embodiment of the present invention may further have the following additional technical features:

[0016] Further, an adjustment buckle for adjusting the effective length of the chin strap assembly is provided on the buckle strap inserted into the male buckle.

[0017] Further, an anti - detachment buckle for fixing the free end of the buckle strap is provided at the end of the buckle strap inserted into the male buckle, and the anti - detachment buckle is integrally fixed to the buckle strap through insert molding technology.

[0018] Further, the integral connection area between the cap hoop connector and the fixing strap, the integral connection area between the snap fastener and the buckle strap, and the integral connection area between the female buckle and the buckle strap all include at least one hole formed during the injection molding process.

[0019] Further, the integrated connection area between the anti-release buckle and the buckle strap includes at least one hole formed during the injection molding process.

[0020] Another object of an embodiment of the present invention is to provide a method for manufacturing a chin strap assembly for manufacturing the chin strap assembly as described above. The method includes the following injection molding steps:

[0021] Manufacturing the cap hoop connecting member: Place the end of the pre-treated fixing strap at a predetermined position in a first injection mold having a cavity defining the outer shape of the cap hoop connecting member, and fix it by components in the first injection mold; Inject the molten first plastic into the cavity of the first mold, and cover the end of the fixed fixing strap by injection molding; and obtain the cap hoop connecting member integrally connected to the fixing strap through pressure holding, cooling, and ejection.

[0022] Manufacturing the mating buckle: Place the corresponding buckle strap and the end of the buckle strap that has been pre-treated and wound around the fixing strap at a predetermined position in a second injection mold having a cavity defining the outer shape of the mating buckle, and fix it by components in the second injection mold, wherein the end of the buckle strap is positioned adjacent to the main body of the buckle strap; Inject the molten second plastic into the cavity of the second mold, and simultaneously cover a part of the main body of the buckle strap and the fixed end of the buckle strap by injection molding; and obtain the mating buckle through pressure holding, cooling, and ejection. The mating buckle is integrally connected to the main body of the buckle strap, and at the same time, the end of the buckle strap is fixed to form a closed structure surrounding the fixing strap.

[0023] Manufacturing the female buckle: Place the end of a buckle strap that has been pre-treated and is used to connect to the female buckle in the plug buckle system at a predetermined position in a third injection mold having a cavity defining the outer shape of the female buckle, and fix it by components in the third injection mold; Inject the molten third plastic into the cavity of the third mold, and cover the fixed end of the buckle strap by injection molding; and obtain the female buckle integrally connected to the buckle strap through pressure holding, cooling, and ejection.

[0024] Further, the method further includes the following injection molding steps:

[0025] Manufacturing the anti-release buckle: Place the end of the buckle strap that has been pre-treated and passed through the male buckle at a predetermined position in a fourth injection mold having a cavity defining the outer shape of the anti-release buckle, and fix it by components in the fourth injection mold; Inject the molten fourth plastic into the cavity of the fourth mold, and cover the fixed end of the buckle strap by injection molding; and obtain the anti-release buckle integrally connected to the end of the buckle strap through pressure holding, cooling, and ejection.

[0026] Further, the step of fixing by components in the first injection mold includes:

[0027] The end of the fixing band is compacted by using a pressing block structure arranged in the cavity of the first injection mold, and is further fixed by using at least one positioning post structure protruding from one side or both sides of the first injection mold to abut against or pass through the end of the fixing band;

[0028] The step of fixing by means of the components in the second injection mold includes:

[0029] The buckle band and the end of the buckle band wound around the fixing band are compacted by using a pressing block structure arranged in the cavity of the second injection mold, and are further fixed by using at least one positioning post structure protruding from one side or both sides of the second injection mold to abut against or pass through the buckle band and the end of the buckle band;

[0030] The step of fixing by means of the components in the third injection mold includes:

[0031] The end of the buckle band for connecting with the female buckle is compacted by using a pressing block structure arranged in the cavity of the third injection mold, and is further fixed by using at least one positioning post structure protruding from one side or both sides of the third injection mold to abut against or pass through the end of the buckle band.

[0032] Furthermore, the step of preprocessing the end of the fixing band and the end of the buckle band includes:

[0033] The cut edges of the end of the fixing band and / or the end of the buckle band are processed by ultrasonic melting to form a closed and regular edge structure.

[0034] Another object of the embodiment of the present invention is also to provide a safety helmet, including a helmet shell, a top band fixedly connected to the helmet shell, a cap band fixedly connected to the top band, and a chin strap assembly as described above fixedly connected to the cap band.

[0035] The chin strap assembly provided by the embodiment of the present invention is formed by insert injection molding of the cap hoop connecting piece at the end of the connecting fixing strap, the mating buckle at the end of the connecting buckle strap, and the female buckle at the end of the connecting buckle strap. By directly coating the end of the fabric strap with molten plastic and forming a physical locking interface, the seamless integration of the fabric and the plastic is realized. This three-dimensional physical embedding structure disperses the stress from points (sewing holes) to the surface. Its connection strength far exceeds that of traditional sewing, and there are no problems such as sewing thread wear and breakage, greatly improving the tensile strength, anti-fatigue performance and overall durability of the key connection points of the chin strap assembly, and significantly extending the service life of the product; due to the very high strength of the insert injection connection, the connection point is no longer the weak link of the assembly, and the failure mode more shifts to the ultimate strength of the fabric strap or the plastic part itself, thereby improving the reliability and safety of the entire chin strap assembly and even the safety helmet; by integrating the connection process into the injection molding process, the independent sewing steps are reduced, and the production process is shortened. Although the insert placement process is required, overall, especially in large-scale automated production, the production efficiency is effectively improved, the comprehensive manufacturing cost is reduced, and the product consistency is improved; at the same time, the seamless integration makes the transition between the fabric strap and the plastic part smooth and natural, the appearance is more concise and beautiful, and due to the absence of sewing thread gaps, it is also more convenient for cleaning and maintenance; for the design of the mating buckle, the buckle strap body and the surrounding end can be simultaneously and firmly integrated and fixed by insert injection molding, achieving the structural compactness, connection reliability and functional stability that are difficult to achieve by traditional processes; similarly, by fixing small parts such as anti-release buckles by insert injection molding, it is also more firm and reliable than the traditional method, solving the problems of low connection strength, poor durability and complex process of the existing chin strap connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic structural view of the chin strap assembly in the first embodiment of the present invention from the first perspective;

[0037] Figure 2 It is a schematic structural view of the chin strap assembly in the first embodiment of the present invention from the second perspective;

[0038] Figure 3 It is a schematic structural view of the chin strap assembly in the first embodiment of the present invention from the third perspective;

[0039] Figure 4 It is a flowchart of the manufacturing method of the chin strap assembly in the second embodiment of the present invention;

[0040] Figure 5 It is an exploded view of the safety helmet in the third embodiment of the present invention from the fourth perspective;

[0041] Figure 6 It is a schematic structural view of the safety helmet in the third embodiment of the present invention from the fifth perspective;

[0042] Figure 7 This is a schematic structural view of the safety helmet in the third embodiment of the present invention from the sixth perspective;

[0043] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. Specific Embodiments

[0044] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0045] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used herein in the description of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0047] Embodiment 1

[0048] Please refer to Figures 1 - 3 , which shows the chin strap assembly in the first embodiment of the present invention. For the convenience of description, only the parts related to the embodiments of the present invention are shown. The chin strap assembly 40 provided by the embodiments of the present invention is applied to a safety helmet and includes:

[0049] Two fixing straps 41;

[0050] Two buckle straps 42, each buckle strap 42 is respectively wound around the corresponding fixing strap 41;

[0051] Two cap hoop connectors 43, each cap hoop connector 43 is integrally connected to the end of the corresponding fixing strap 41 by insert molding, and a connection structure 431 for cooperating with the cap hoop of the safety helmet is provided on the cap hoop connector 43;

[0052] Two snap fasteners 44, each snap fastener 44 is integrally connected to the corresponding buckle strap 42 and the end of the buckle strap 42 wrapped around the fixed strap 41 through insert molding process;

[0053] And a snap system 45, including a male snap 451 and a female snap 452 which cooperate with each other. The end of one buckle strap 42 is integrally connected to the female snap 452 through insert molding process, and the other buckle strap 42 is threaded through the male snap 451.

[0054] Wherein, in an embodiment of the present invention, the chin strap assembly is mainly applied to safety helmets used in various industries, construction, sports and other fields, and is used to firmly fix the safety helmet on the user's head. The chin strap assembly mainly includes two fixed straps 41 and two buckle straps 42. The fixed strap 41 is the main load-bearing part of the chin strap assembly and is usually made of woven materials with high tensile strength and wear resistance, such as nylon, polyester fiber or terylene and other webbing. The length of the fixed strap 41 is determined according to the safety helmet design and the position of the expected connection point. At this time, the fixed strap 41 provides a basic support structure, bears the main tensile force, and ensures the overall stability of the chin strap assembly. Both ends of the fixed strap 41 are connected to the cap hoop of the safety helmet (through the cap hoop connector 43), and the middle part is located at the side rear or below the user's head during wearing, serving as the basis for the buckle strap 42 to wrap around. The buckle strap 42 usually uses the same or similar material as the fixed strap 41, but may have slightly different widths or thicknesses. Before use or during the manufacturing process of each buckle strap 42, one section of it wraps around the corresponding fixed strap 41 to form a relatively slidable loop. The buckle strap 42 is the key part to realize the length adjustment and buckling function of the chin strap assembly. One end of the buckle strap 42 is connected to the snap fastener 44, and the other end participates in the connection or adjustment of the snap system 45. At this time, an adjustable Y-shaped structure basis is formed by wrapping around the fixed strap 41, which is convenient for subsequent connection of the snap fastener 44 and the snap system 45 to realize the multi-point fixation and adjustment functions.

[0055] Further, in an embodiment of the present invention, the cap hoop connector 43 is a plastic component, usually injection-molded from engineering plastics such as polyoxymethylene (POM), polypropylene (PP), polyamide (PA), etc. The lower part of each cap hoop connector 43 is integrally connected to the end of the corresponding fixing strap 41 through insert injection molding. This means that when the cap hoop connector 43 is injection-molded, the end of the fixing strap 41 is pre-placed in the mold cavity, and then molten plastic is injected. After the plastic solidifies, it firmly wraps the end of the fixing strap 41 inside, forming a seamless and high-strength combination. The upper part of the cap hoop connector 43 is provided with a connection structure 431 for mating connection with the cap hoop of the safety helmet. In this preferred embodiment, the connection structure 431 is a T-shaped hole, which can be conveniently and firmly snapped or inserted into the corresponding fixing points (such as fixing posts) on the cap hoop. Therefore, in the embodiment of the present invention, the fixing strap 41 is usually connected by insert injection molding, completely replacing the traditional sewing connection method. The plastic completely wraps and may penetrate into the gaps between the webbing fibers, forming a strong mechanical lock and chemical bond (depending on the material), greatly improving the tensile and detachment resistance and durability of the connection point, eliminating the risk of aging and fracture caused by factors such as wear, ultraviolet radiation, and chemical corrosion in the traditional sewing connection. At the same time, the injection molding speed is fast, automated production can be achieved, the manual sewing process is reduced, the production efficiency is improved, and the manufacturing cost is reduced. In addition, the integrated connection makes the connection part smoother and more regular, improving the overall aesthetics of the product. The connection structure 431 with a T-shaped hole design provides a reliable and convenient cap hoop connection method for disassembly and assembly.

[0056] Further, in an embodiment of the present invention, the snap fastener 44 is also a plastic component, and its material is similar to that of the cap hoop connector 43. Each snap fastener 44 is integrally connected to the corresponding buckle strap 42 (main body part) and the end of the buckle strap 42 wrapped around the fixing strap 41 through insert injection molding. That is, during injection molding, the main body part of the buckle strap 42 and the end of the buckle strap 42 loop formed by wrapping around the fixing strap 41 are simultaneously placed in specific positions of the mold. After the molten plastic is injected, these two parts are simultaneously wrapped and fixed together, forming a stable Y-shaped fork structure that is both connected to the main body of the buckle strap 42 and can lock the end of the wrapped buckle strap 42, so that the force from the buckle strap 42 is transmitted to the fixing strap 41, and the structure of the buckle strap 42 wrapping around the fixing strap 41 is permanently fixed. Compared with the traditional independent fixing ring or sewing fixation, the fixation through the insert injection molding process of the snap fastener 44 not only has high strength and good durability, but also has a compact structure, avoiding the risk of component loosening or loss, and ensuring the stability of the wrapped state of the buckle strap 42. Similarly, the insert injection molding provides a high-strength connection, avoiding the disadvantages of the traditional sewing connection. And integrating multiple connection functions on one injection molded part (snap fastener 44) reduces the number of parts and assembly steps.

[0057] Further, in an embodiment of the present invention, the snap-fastening system 45 includes a male snap 451 and a female snap 452 that cooperate with each other. One end of a strap 42 (usually the shorter or fixed-length side) is integrally connected to the female snap 452 through insert molding. Similar to the cap hoop connector 43, the end of the strap 42 is covered and fixed during injection molding to form the female snap 452. The other strap 42 (usually the side where the length needs to be adjusted) is threaded through the male snap 451, and a channel or lever structure for passing through and fixing the strap 42 is usually provided on the male snap 451. By adopting the snap-fastening system 45, a convenient and quick wearing and removal function, as well as a basis for length adjustment, are provided. At the same time, the female snap 452 is connected by insert molding and also has the advantages of high strength, high durability, seamless beauty. And the male snap 451 is threaded, providing a basis for length adjustment.

[0058] Among them, in an embodiment of the present invention, in order to facilitate the user to adjust the tightness of the chin strap assembly according to their own head shape and wearing habits, at this time, an adjustment buckle 46 is provided on the strap 42 threaded through the male snap 451, that is, an adjustment buckle 46 for adjusting the effective length of the chin strap assembly is provided on the strap 42 threaded through the male snap 451. The adjustment buckle 46 is usually a D-ring or a three-way buckle or a plastic or metal part with a similar structure. At this time, the strap 42 passes through the adjustment buckle 46, and the stepless or stepped adjustment of the effective length of the strap 42 is realized through friction or the lever principle. At this time, the user can change the effective length of the chin strap assembly by pulling the strap 42 through the adjustment buckle 46 as needed, ensuring that the safety helmet does not shake or fall off during activities, so that the user is allowed to conveniently tighten or loosen the chin strap assembly to achieve a comfortable and safe wearing state. The applicability, wearing comfort and safety of the chin strap assembly are improved.

[0059] Among them, in an embodiment of the present invention, in order to handle the free end of the strap 42 that is redundant after passing through the male snap 451 and the adjustment buckle 46, an anti-disengagement buckle 47 is provided at the end of the free end. That is, an anti-disengagement buckle 47 for fixing the free end of the strap 42 is provided at the end of the strap 42 threaded through the male snap 451, and the anti-disengagement buckle 47 is integrally fixed to the strap 42 through insert molding. The anti-disengagement buckle 47 is a small plastic part and is integrally fixed to the end of the strap 42 through insert molding. It is usually designed as a flat block or with a simple snap structure to prevent the end of the strap 42 from accidentally slipping out of the adjustment buckle 46, and at the same time avoid the messy shaking of the free end of the strap 42, making the appearance neater.

[0060] Among them, in an embodiment of the present invention, the integrated connection area between the cap hoop connector 43 and the fixing strap 41, the integrated connection area between the mating buckle 44 and the buckle strap 42, and the integrated connection area between the female buckle 452 and the buckle strap 42 all include at least one hole formed during the injection molding process. Further, the integrated connection area between the anti-release buckle 47 and the buckle strap 42 includes at least one hole formed during the injection molding process. These holes are the result of the injection mold design. Before injection molding, in order to accurately and firmly position the end of the webbing at a predetermined position in the mold cavity and prevent it from shifting under the impact of the high-temperature and high-pressure molten plastic, a positioning post structure is usually provided in the mold. These positioning posts will protrude from one or both sides of the mold and abut against or pass through the end of the webbing. When the injection molding is completed and the positioning posts are withdrawn, holes corresponding to the shape of the positioning posts are left on the plastic part. At the same time, the pressing block structure in the mold will press the webbing to ensure that it closely adheres to the mold surface. These holes are the natural result of the manufacturing process, mainly due to the need to ensure the precise positioning and fixation of the webbing during the injection molding process. The existence of these holes indirectly proves that precise positioning measures have been adopted, ensuring the accuracy of the insert position and product consistency, helping to ensure that the webbing is correctly coated, and thus ensuring the strength and reliability of the insert injection connection. At the same time, in some cases, the plastic at the edge of the hole is more tightly combined with the webbing fibers, or the plastic slightly flows into the pores of the webbing, which can enhance the shear or peel resistance of the combined part to a certain extent, forming a stronger physical locking, and further enhancing the mechanical locking force microscopically.

[0061] In summary, for the chin strap assembly in the above embodiments of the present invention, the cap hoop connecting member at the end of the connecting fixing strap, the mating buckle at the end of the connecting buckle strap, and the female buckle at the end of the connecting buckle strap are formed by insert injection molding. By directly coating the end of the fabric strap with molten plastic to form a physical locking interface, the seamless integration of the fabric and the plastic is achieved. This three-dimensional physical embedding structure disperses the stress from points (stitching holes) to the surface. Its connection strength far exceeds that of traditional stitching, and there are no problems such as stitching wear and breakage, greatly improving the tensile strength, anti-fatigue performance, and overall durability of the key connection points of the chin strap assembly, and significantly extending the service life of the product. Since the strength of the insert injection connection is very high, the connection point is no longer the weak link of the assembly, and the failure mode is more transferred to the ultimate strength of the fabric strap or the plastic part itself, thereby improving the reliability and safety of the entire chin strap assembly and even the safety helmet. By integrating the connection process into the injection molding process, the independent stitching steps are reduced, and the production process is shortened. Although the insert placement process is required, overall, especially in large-scale automated production, the production efficiency is effectively improved, the comprehensive manufacturing cost is reduced, and the product consistency is improved. At the same time, the seamless integration makes the transition between the fabric strap and the plastic part smooth and natural, the appearance is more concise and beautiful, and due to the absence of stitching gaps, it is also more convenient for cleaning and maintenance. For the design of the mating buckle, the buckle strap body and the surrounding end can be integrally and firmly fixed simultaneously by insert injection molding, achieving the structural compactness, connection reliability, and functional stability that are difficult to achieve by traditional processes. Similarly, by fixing small components such as anti-release buckles by insert injection molding, it is also more firm and reliable than the traditional method, solving the problems of low connection strength, poor durability, and complex process of the existing chin strap connection.

[0062] Embodiment 2

[0063] Please refer to Figure 4 , which shows the manufacturing method of the chin strap assembly in the second embodiment of the present invention. For the convenience of description, only the parts related to the embodiments of the present invention are shown. The manufacturing method of the chin strap assembly provided by the embodiments of the present invention is used to manufacture the chin strap assembly described in the foregoing embodiments. The method includes the following injection molding steps:

[0064] Step S10, manufacturing the cap hoop connecting member: Place the end of the pretreated fixing strap at a predetermined position in the first injection mold with a cavity defining the outer shape of the cap hoop connecting member, and fix it through the components in the first injection mold; Inject the first type of plastic in a molten state into the cavity of the first mold, and coat the fixed end of the fixing strap by injection molding; and obtain the cap hoop connecting member integrally connected to the fixing strap through pressure holding, cooling, and ejection.

[0065] Among them, in an embodiment of the present invention, before injection molding, the ends of the fixing straps and the ends of the fastening straps that need to be connected with the plastic by inserts (including the ends of the fixing straps for the cap hoop connectors, the main body part and the surrounding ends of the fastening straps for the mating buckle, the ends of the fastening straps for the female buckle, and the ends of the fastening straps for the anti-release buckle) are pretreated. Preferably, the ultrasonic melting method is used to treat the cut edges of the ends of the fixing straps and / or the ends of the fastening straps to form a closed and regular edge structure. Among them, an ultrasonic melting device is used to treat the cut edges of these fabric straps. The heat generated by the high-frequency vibration of the ultrasonic waves causes the edge fibers to quickly melt and then cool and solidify, forming a smooth, closed, burr-free and somewhat hard coated edge. This step effectively prevents the fabric straps from spreading during use and manufacturing, provides a clean and regular interface, facilitates subsequent precise positioning and fixing in the mold, and helps to form a better seal during injection molding, reduce plastic overflow (flash), and improve the final connection quality and appearance.

[0066] Furthermore, the pretreated ends of the fixing straps are manually or automatically placed at a predetermined position in the first injection mold (with a cavity defining the shape of the cap hoop connector). A positioning device is provided inside the mold to complete the fixation. The positioning device preferably includes: a pressing block structure, arranged at the bottom or side of the cavity, providing preliminary pressing and positioning for the placed fabric strap; at least one positioning post structure, protruding from one or both sides of the mold during or after mold closing, precisely abutting against or passing through the fabric strap, and cooperating with the pressing block to finally firmly lock it in the spatial position. Therefore, the step of fixing by the components in the first injection mold includes: using the pressing block structure arranged in the cavity of the first injection mold to press the ends of the fixing straps, and using at least one positioning post structure protruding from one or both sides of the first injection mold to further abut against or pass through the ends of the fixing straps for fixation. At this time, the combined use of the pressing block and the positioning post can resist the mold closing pressure and the impact of the high-pressure melt, ensuring that the fabric insert does not displace during the entire injection molding process, thereby ensuring the consistency of the final product size accuracy, connection strength and appearance quality.

[0067] Further, close the corresponding first injection mold, and inject the first type of molten plastic (which can be the same or different engineering plastics selected according to component requirements) into the mold cavity through the gate system (preferably a large runner or a direct gate to reduce flow resistance). The molten plastic flows and completely wraps the end (or specific part) of the fixed fabric tape, and flows around the positioning post structure. Further, apply pressure holding to make the plastic filling denser and compensate for shrinkage. Then, rapidly cool through the mold cooling system to solidify the plastic. At this time, during the plastic solidification process, it penetrates into the gaps of the fabric fibers and tightly "grabs" these fibers and the hardened edges formed by pretreatment during cooling shrinkage, forming a strong physical locking. This physical locking provides mechanical connection strength and anti-fatigue performance far exceeding that of traditional stitching. Further, open the first injection mold, activate the ejection mechanism (such as ejector pins, ejector plates) to eject the formed cap hoop connecting member (fabric tape and solidified plastic functional member), and obtain the cap hoop connecting member integrally connected to the fixed tape. Among them, when ejecting, the cap hoop connecting member is separated from the positioning post, and holes are naturally formed in the connection area.

[0068] Step S20, manufacture the snap fastener: Place the corresponding buckle tape and the end of the buckle tape that has been pre-treated and wound around the fixed tape at the predetermined positions in the second injection mold with a cavity defining the shape of the snap fastener, and fix them through the components in the second injection mold; Inject the second type of molten plastic into the cavity of the second mold, and simultaneously wrap a part of the buckle tape body and the fixed end of the buckle tape through injection molding; and obtain the snap fastener through pressure holding, cooling, and ejection;

[0069] Among them, in an embodiment of the present invention, first, the end of the buckle belt to be wrapped around the fixing belt is subjected to the pretreatment operation as described above. Then, a part of the corresponding buckle belt main body and the pretreated end of the buckle belt that has been wrapped around the fixing belt are placed at a predetermined position in a second injection mold (having a cavity defining the shape of the mating buckle). It should be noted that the end of the buckle belt is positioned adjacent to the main body of the buckle belt and is jointly coated. Then it is fixed in a similar manner as described above. Specifically, the steps of fixing by the components in the second injection mold include: using a pressing block structure provided in the cavity of the second injection mold to press the buckle belt and the end of the buckle belt that has been wrapped around the fixing belt, and using at least one positioning post structure extending from one side or both sides of the second injection mold to further abut against or pass through the buckle belt and the end of the buckle belt for fixing. Then the corresponding second injection mold is closed, and the molten second plastic (which can be the same as or different from the first one) is injected into the cavity of the second injection mold. Through the injection molding, pressure holding, cooling, and ejection processes as described above, a mating buckle covering a part of the buckle belt main body and the fixed end of the buckle belt is formed. The mating buckle is integrally connected to the buckle belt main body, and at the same time, the end of the buckle belt is fixed to form a closed structure around the fixing belt. This step cleverly completes two tasks with one injection molding: connecting the mating buckle to the buckle belt and permanently locking the loop formed by the buckle belt around the fixing belt, with a very stable and efficient structure.

[0070] Step S30, manufacturing the female buckle: Place the end of a buckle belt that has been pretreated and is used to connect to the female buckle in the plug buckle system at a predetermined position in a third injection mold having a cavity defining the shape of the female buckle, and fix it through the components in the third injection mold; inject the molten third plastic into the cavity of the third mold, and coat and fix the end of the buckle belt through injection molding; and obtain the female buckle integrally connected to the buckle belt through pressure holding, cooling, and ejection.

[0071] Among them, in an embodiment of the present invention, first, the end of the buckle belt connected to the female buckle is subjected to the pretreatment operation as described above. Then, the corresponding pretreated end of a buckle belt used to connect to the female buckle in the plug buckle system is placed at a predetermined position in a third injection mold (having a cavity defining the shape of the female buckle). Then it is fixed in a similar manner as described above. Specifically, the steps of fixing by the components in the third injection mold include: using a pressing block structure provided in the cavity of the third injection mold to press the end of the buckle belt used to connect to the female buckle, and using at least one positioning post structure extending from one side or both sides of the third injection mold to further abut against or pass through the end of the buckle belt for fixing. Then the corresponding third injection mold is closed, and the molten third plastic (which can be the same as or different from the previous two) is injected into the cavity of the third injection mold. Through the injection molding, pressure holding, cooling, and ejection processes as described above, a female buckle covering the end of the buckle belt is formed.

[0072] Further, in an embodiment of the present invention, after all necessary insert molding parts are manufactured, final assembly is required. This includes threading the adjustment buckle onto the corresponding buckle strap, threading the male buckle onto the corresponding buckle strap, and assembling the male buckle with the female buckle.

[0073] Further, in other embodiments of the present invention, the method further includes the following injection molding steps:

[0074] Manufacturing an anti - detachment buckle: placing the end of the buckle strap that has been pre - treated and threaded through the male buckle at a predetermined position within a fourth injection mold having a cavity that defines the outer shape of the anti - detachment buckle, and fixing it by means of components within the fourth injection mold; injecting a fourth type of molten plastic (which can be the same as or different from the previous three types) into the cavity of the fourth mold, and fixing the end of the buckle strap through injection molding and coating; and obtaining an anti - detachment buckle integrally connected to the end of the buckle strap through pressure holding, cooling, and ejection.

[0075] Among them, in the embodiments of the present invention, the specific structural content of the chin strap assembly manufactured by using the method of this embodiment can be referred to the description in the foregoing embodiments. Its implementation principle and the technical effects produced are the same as those of the foregoing embodiments. For the sake of brief description, for the parts not mentioned in this embodiment, reference can be made to the corresponding content in the foregoing embodiments. In the embodiments of the present invention, the regularity of the insert edge is ensured by ultrasonic pretreatment, and the precise positioning of the insert during the injection molding process is guaranteed by in-mold fixing technologies such as the pressure block and positioning posts. All these contribute to improving the dimensional accuracy and quality consistency of the final product; and by forming the cap hoop connecting piece at the end of the connecting fixing strap, the mating buckle at the end of the connecting buckle strap, and the female buckle at the end of the connecting buckle strap by the above-mentioned insert injection molding process, the tensile strength, fatigue resistance and overall durability of the key connection points of the chin strap assembly are greatly improved, and the service life of the product is significantly extended; due to the very high strength of the insert injection connection, the connection point is no longer the weak link of the assembly, and the failure mode is more transferred to the ultimate strength of the fabric belt or the plastic part itself, thereby improving the reliability and safety of the entire chin strap assembly and even the safety helmet; by integrating the connection process into the injection molding process, the independent sewing steps are reduced, and the production process is shortened. Although the insert placement process is required, overall, especially in large-scale automated production, the production efficiency is effectively improved, the comprehensive manufacturing cost is reduced, and the product consistency is improved; at the same time, the integrated seamless connection makes the transition between the fabric belt and the plastic part smooth and natural, the appearance is more concise and beautiful, and because there is no sewing seam, it is also more convenient for cleaning and maintenance; for the design of the mating buckle, the buckle belt body and the surrounding end can be integrally and firmly fixed simultaneously by insert injection molding, achieving the structural compactness, connection reliability and functional stability that are difficult to achieve by traditional processes; similarly, by fixing small parts such as anti-detachment buckles by insert injection molding, it is also more firm and reliable than the traditional method, solving the problems of low connection strength, poor durability and complex process of the existing chin strap connection.

[0076] Embodiment III

[0077] Please refer to Figures 5 - 7 , which shows the safety helmet in the third embodiment of the present invention. For the convenience of description, only the parts related to the embodiments of the present invention are shown. The safety helmet provided by the embodiments of the present invention includes a helmet shell 10, a top strap 20 fixedly connected to the helmet shell 10, a cap hoop 30 fixedly connected to the top strap 20, and a chin strap assembly 40 as described in the foregoing embodiments and fixedly connected to the cap hoop 30.

[0078] Furthermore, in an embodiment of the present invention, the safety helmet further includes a sweat-absorbing strap 50 fixedly connected to the cap hoop, where reference is made to Figure 5As shown, the cap hoop 30 includes a ring band, an adjustment band and an adjustment buckle respectively connected to both ends of the ring band; ventilation holes, anti-collision columns, fixing columns for connecting and fixing the top band and the chin strap, and fixing protrusions for connecting and fixing the sweat-absorbing band are provided along the length direction of the ring band. The ventilation holes are used to increase the ventilation and heat dissipation of the ring band and disperse stress. The anti-collision columns are used to disperse the impact force, avoid direct contact between the cap shell and the user's head, reduce the impact on the user's head top caused by the deformation of the cap shell under stress, and prevent head injuries. The fixing columns are used to cooperate with the fixing holes on the top band of the safety helmet and the connection structure on the chin strap assembly for fixation. Specifically, in this embodiment, the fixing columns are T-shaped columns, the fixing holes on the corresponding top band are T-shaped holes, and the connection structure on the chin strap assembly also uses T-shaped holes. The fixing protrusions are used to pass through the fixing through holes of the sweat-absorbing band to fix the sweat-absorbing band.

[0079] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0080] The above-described embodiments only represent several implementation manners of the present invention, and the description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A chin strap assembly, applied to a safety helmet, characterized in that Comprising: Two fixing straps; Two buckle straps, each of which is respectively wound around the corresponding fixing strap; Two cap hoop connectors, each of which is integrally connected to the end of the corresponding fixing strap by insert molding, and a connection structure for cooperating with the cap hoop of the safety helmet is provided on the cap hoop connector; Two snap fasteners, each of which is integrally connected to the corresponding buckle strap and the end of the buckle strap wound around the fixing strap by insert molding; And a snap fastener system, including a male buckle and a female buckle that cooperate with each other, wherein the end of one of the buckle straps is integrally connected to the female buckle by insert molding, and the other buckle strap is inserted into the male buckle.

2. The chin strap assembly according to claim 1, wherein An adjusting buckle for adjusting the effective length of the chin strap assembly is provided on the buckle strap inserted into the male buckle.

3. The chin strap assembly according to claim 1, characterized in that, An anti - detachment buckle for fixing the free end of the buckle strap is provided at the end of the buckle strap inserted into the male buckle, and the anti - detachment buckle is integrally fixed to the buckle strap by insert molding.

4. The chin strap assembly according to claim 1, wherein The integrally connected area between the cap hoop connector and the fixing strap, the integrally connected area between the snap fastener and the buckle strap, and the integrally connected area between the female buckle and the buckle strap all contain at least one hole formed during the injection molding process.

5. The chin strap assembly according to claim 3, characterized in that, The integrally connected area between the anti - detachment buckle and the buckle strap contains at least one hole formed during the injection molding process.

6. A method for manufacturing a chin strap assembly for manufacturing the chin strap assembly according to any one of claims 1-5, characterized in that, The method includes the following injection molding steps: Manufacturing the cap hoop connector: Place the end of the pre - treated fixing strap at a predetermined position in the first injection mold with a cavity defining the outer shape of the cap hoop connector, and fix it by the components in the first injection mold; Inject the molten first plastic into the cavity of the first mold, and wrap the fixed end of the fixing strap by injection molding; And obtain the cap hoop connector integrally connected to the fixing strap through pressure holding, cooling, and ejection. Manufacturing the snap fastener: Place the corresponding buckle strap and the end of the buckle strap that has been pre - treated and wound around the fixing strap at a predetermined position in the second injection mold with a cavity defining the outer shape of the snap fastener, and fix it by the components in the second injection mold, wherein the end of the buckle strap is positioned adjacent to the main body of the buckle strap; Inject the molten second plastic into the cavity of the second mold, and simultaneously wrap a part of the main body of the buckle strap and the fixed end of the buckle strap by injection molding; And obtain the snap fastener, which is integrally connected to the main body of the buckle strap and simultaneously fixes the end of the buckle strap to form a closed structure around the fixing strap through pressure holding, cooling, and ejection. Manufacturing the female buckle: Place the end of the pre - treated buckle strap for connecting to the female buckle in the snap fastener system at a predetermined position in the third injection mold with a cavity defining the outer shape of the female buckle, and fix it by the components in the third injection mold; Inject the molten third plastic into the cavity of the third mold, and wrap the fixed end of the buckle strap by injection molding; And obtain the female buckle integrally connected to the buckle strap through pressure holding, cooling, and ejection.

7. The method for manufacturing the chin strap assembly according to claim 6, wherein The method further includes the following injection molding steps: Manufacturing anti-disengagement buckle: Place the end of the buckle strap that has been pre-treated and threaded through the male buckle at a predetermined position within a fourth injection mold having a cavity that defines the outer shape of the anti-disengagement buckle, and fix it with components within the fourth injection mold; Inject the fourth type of molten plastic into the cavity of the fourth mold to encapsulate and fix the end of the buckle strap through injection molding; and obtain the anti-disengagement buckle integrally connected to the end of the buckle strap through pressure holding, cooling, and ejection.

8. The method for manufacturing the chin strap assembly according to claim 6, wherein, The step of fixing with components within the first injection mold includes: Using a pressing block structure provided within the cavity of the first injection mold to press the end of the fixing strap, and further fixing it by using at least one positioning post structure extending from one side or both sides of the first injection mold to abut against or pass through the end of the fixing strap. The step of fixing with components within the second injection mold includes: Using a pressing block structure provided within the cavity of the second injection mold to press the buckle strap and the end of the buckle strap that has been wound around the fixing strap, and further fixing it by using at least one positioning post structure extending from one side or both sides of the second injection mold to abut against or pass through the buckle strap and the end of the buckle strap. The step of fixing with components within the third injection mold includes: Using a pressing block structure provided within the cavity of the third injection mold to press the end of the buckle strap for connecting to the female buckle, and further fixing it by using at least one positioning post structure extending from one side or both sides of the third injection mold to abut against or pass through the end of the buckle strap.

9. The manufacturing method of the chin strap assembly according to claim 6, characterized in that, The step of pre-treating the end of the fixing strap and the end of the buckle strap includes: Adopting ultrasonic melting to treat the cut edges of the end of the fixing strap and / or the end of the buckle strap to form a closed and regular edge structure.

10. A safety helmet, characterized in that, It includes a cap shell, a top strap connected and fixed to the cap shell, a cap band connected and fixed to the top strap, and a chin strap assembly as described in any one of claims 1-5 connected and fixed to the cap band.

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