Pull ring and preparation method thereof

Abstract

The pull ring sequentially comprises a core mold, a core layer and a protective layer from inside to outside, the core mold comprises two cylindrical coils with the axes collinear to a first axis at one end and a semi-cylindrical coil with the rotation axis perpendicular to the first axis at the other end, and the two ends of the semi-cylindrical coil point to the two cylindrical coils respectively. The core layer is wound on the surface of the core mold along the longitudinal direction according to a preset line shape to form a middle transition layer; and the protective layer is transversely wound on the surface of the core layer in an S-shaped spiral track. The pull ring is formed by winding fiber reinforced composite materials, and the weight of the pull ring is reduced by 40% or above compared with that of a steel pull ring of the same model. The pull ring is prepared by adopting a composite winding process, so that the overall mechanical property of the pull ring is effectively ensured. The performance of the composite material pull ring can be optimized by adjusting the arrangement of the fibers and the variety of the resin, and various use requirements can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of power transmission and transformation construction, in particular to a pull ring and a preparation method thereof. Background Art

[0002] In many industrial applications, such as aerospace, automotive, and sports equipment, the requirements for materials are becoming increasingly stringent. While traditional metal materials have certain advantages, they can no longer meet the requirements of modern technology in terms of certain performance indicators. This is also the reason for the development trend of pull rings. Contemporary technological developments have placed higher demands on the strength, durability, and lightweight nature of pull rings. However, traditional steel pull rings have a high density, making them a less than ideal choice for applications requiring lightweight designs. Although steel pull rings can be improved in corrosion resistance through galvanizing, chrome plating, or other surface treatments, these treatments can increase costs, and the treated surface can still expose the underlying steel when scratched or worn, leading to corrosion. To improve the strength of steel pull rings, it may be necessary to increase their thickness or use higher-strength steel, which will further increase weight.

[0003] Therefore, how to invent a pull ring that meets the requirements of high strength, corrosion resistance, lightweight and flexible design to replace the traditional steel pull ring is a technical problem that needs to be solved urgently in the field of power transmission and transformation construction technology. Summary of the Invention

[0004] In order to solve the technical problems of low strength, poor corrosion resistance and bulkiness of pull rings in the prior art, the present invention provides a pull ring, which comprises, from the inside to the outside, a core mold, a core layer and a protective layer;

[0005] The core mold includes: two cylindrical coils with axes collinear with a first axis at one end, and a semi-cylindrical coil with a rotation axis perpendicular to the first axis at the other end, with both ends of the semi-cylindrical coil pointing to the two cylindrical coils respectively;

[0006] The core layer is wound on the surface of the core mold in a predetermined linear shape along the longitudinal direction to form an intermediate transition layer;

[0007] The protective layer is transversely wound around the surface of the rigid core layer in an S-shaped spiral track.

[0008] The protective layer is transversely wound on the surface of the core layer in an S-shaped spiral track.

[0009] Preferably, the core layer comprises: continuous fibers impregnated with resin glue.

[0010] Preferably, the protective layer comprises: carbon fiber fabric impregnated with resin glue.

[0011] Preferably, the continuous fiber includes any one of carbon fiber, glass fiber, Kevlar, and PBO fiber.

[0012] Preferably, the fiber content in the pull ring is 50% to 70%.

[0013] Preferably, the carbon fiber includes: one of T300, T700, T800, and T1000.

[0014] Preferably, each layer of the carbon fiber fabric structure includes at least one of plain weave, twill weave and satin weave.

[0015] Preferably, the fiber specifications of the carbon fiber fabric include any one of 3K, 6K, 12K, 24K or 36K.

[0016] Preferably, the resin glue comprises any one of a thermosetting epoxy resin system and an in-situ polymerized thermoplastic resin system.

[0017] Preferably, the properties of the thermosetting epoxy resin system include any one of high and low temperature resistance, medium and normal temperature curing, high strength, and high toughness.

[0018] Preferably, the thermosetting resin may be any one of epoxy resin, unsaturated polyester resin, phenolic resin, urea-formaldehyde resin and the like.

[0019] Preferably, the thermoplastic resin includes any one of polyamide resin, polyacrylic resin and the like.

[0020] A method for preparing a pull ring as described in any one of the above items comprises the following steps:

[0021] Two cylindrical coils and one semi-cylindrical coil are mounted on a ring-shaped winding core mold frame to form a core mold;

[0022] Dipping the continuous fiber into the resin glue solution to fully wet it to form a first intermediate;

[0023] longitudinally winding the first intermediate between the cylindrical coil and the semi-cylindrical coil to form a core layer;

[0024] Winding the impregnated carbon fibers transversely around the core layer to form a second intermediate;

[0025] solidifying the second intermediate to obtain a third intermediate;

[0026] The third intermediate is removed from the core mold, corrected and processed to obtain a final pull ring.

[0027] Preferably, the thickness of the core layer wrapped around the core mold is 5 to 20 mm.

[0028] Preferably, the thickness of the protective layer wrapped around the core layer is 0.5 to 5 mm.

[0029] Preferably, the width of the narrow strip of the protective layer wrapped around the core layer is 5 to 50 mm.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The unique structure of the core mold forms a stable support frame. The cylindrical coil provides longitudinal support, while the semi-cylindrical coil creates a smooth transition between the transverse and longitudinal directions. This evenly distributes stress across the entire pull ring when subjected to force, preventing stress concentration and structural damage, significantly enhancing the pull ring's overall strength and durability. The core layer is wound longitudinally onto the core mold surface in a predetermined linear pattern, forming an intermediate transition layer. This winding method further enhances the pull ring's structural strength while creating a smooth transition between the core mold and the protective layer. The intermediate transition layer effectively cushions external forces from impacting the pull ring, reducing the likelihood of direct external forces acting on the core mold, further enhancing the pull ring's impact resistance and service life. The protective layer is wound transversely onto the core layer surface in an S-shaped spiral pattern. This unique winding method ensures uniform coverage across the entire pull ring, forming a tight and continuous protective barrier. This S-shaped spiral winding pattern not only effectively prevents external environmental damage to the pull ring's internal structure, such as preventing dust and moisture from entering the pull ring, but also increases friction, making it easier to grip and operate during use. In addition, this winding method can also improve the stability of the protective layer itself, making it less likely to loosen or fall off during long-term use, thereby better playing a protective role. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is the overall structure diagram of the pull ring of the present invention;

[0033] 1- cylindrical coil; 2- semi-cylindrical coil; 3- core layer; 4- protective layer. DETAILED DESCRIPTION

[0034] In order to better understand the present invention, the present invention is further described below with reference to the accompanying drawings and examples.

[0035] A pull ring, comprising, from inside to outside, a core mold, a core layer 3 and a protective layer 4;

[0036] The core mold includes: two cylindrical coils 1 with their axes collinear with the first axis at one end, and a semi-cylindrical coil 2 with its rotation axis perpendicular to the first axis at the other end, with both ends of the semi-cylindrical coil 2 pointing to the two cylindrical coils 1 respectively;

[0037] The core layer 3 is wound longitudinally along a predetermined linear pattern around the core mold surface, forming an intermediate transition layer. This winding method further enhances the structural strength of the pull ring while creating a good connection and transition between the core mold and the protective layer 4. The presence of the intermediate transition layer effectively cushions the impact of external forces on the pull ring, reducing the likelihood of external forces directly acting on the core mold, further improving the pull ring's impact resistance and service life.

[0038] The protective layer 4 is wound transversely around the core layer 3 in an S-shaped spiral. This unique winding method allows the protective layer 4 to evenly cover the entire surface of the pull ring, forming a tight and continuous protective barrier. This S-shaped spiral winding method not only effectively prevents external environmental erosion of the pull ring's internal structure, such as preventing dust and moisture from entering the pull ring, but also increases the pull ring's friction to a certain extent, making it easier to grasp and operate during use. Furthermore, this winding method improves the stability of the protective layer 4, preventing it from loosening or falling off during long-term use, thereby further enhancing its protective function.

[0039] Continuous fibers impregnated with resin adhesive. Carbon fiber fabric impregnated with resin adhesive. Any of carbon fiber, glass fiber, Kevlar, and PBO fiber. The fiber content in the pull ring is 50% to 70%. Carbon fibers include T300, T700, T800, and T1000. The carbon fiber fabric can be any of 3K, 6K, 12K, 24K, or 36K.

[0040] Each layer in the carbon fiber fabric structure includes at least one of plain weave, twill weave and satin weave.

[0041] The resin glue comprises any one of a thermosetting epoxy resin system and an in-situ polymerized thermoplastic resin system.

[0042] The characteristics of thermosetting epoxy resin systems include resistance to high and low temperatures, curing at medium and normal temperatures, high strength, and high toughness.

[0043] The thermosetting resin may be any one of epoxy resin, unsaturated polyester resin, phenolic resin, urea-formaldehyde resin and the like.

[0044] Thermoplastic resins include any of polyamide resins, polyacrylic resins, and the like.

[0045] The thickness of the core layer 3 wound around the mandrel is 5 to 20 mm.

[0046] The thickness of the protective layer 4 wrapped around the core layer 3 is within a range of 0.5 to 5 mm.

[0047] The width of the narrow strip of the protective layer 4 wrapped around the core layer 3 is 5 to 50 mm.

[0048] A method for preparing a pull ring as described above comprises the following steps:

[0049] Two cylindrical coils 1 and a semi-cylindrical coil 2 are mounted on a ring-shaped winding core mold frame to form a core mold;

[0050] Dipping the continuous fiber into the resin glue solution to fully wet it to form a first intermediate;

[0051] Winding the first intermediate longitudinally between the cylindrical coil 1 and the semi-cylindrical coil 2 to form a core layer 3;

[0052] The impregnated carbon fibers are transversely wound around the core layer 3 to form a second intermediate;

[0053] solidifying the second intermediate to obtain a third intermediate;

[0054] The third intermediate is removed from the core mold, corrected and processed to obtain the final pull ring.

[0055] The present invention aims to provide a composite pull ring made by a winding process, which can solve the problem of the relatively heavy steel pull rings currently on the market and achieve the goal of lightweight pull rings. The composite pull ring includes: a core mold, a core layer 3, and a protective layer 4.

[0056] The specific manufacturing steps of the pull ring are as follows:

[0057] (1) Preparation of the core mold: Two steel cylindrical coils 1 and a semicircular steel ring are mounted on a winding core mold frame to form a winding core mold. Ensure that the surface of the core mold is smooth and flat to facilitate fiber winding and demoulding after curing.

[0058] (2) Fiber impregnation: Impregnate the continuous fiber in the resin glue to ensure that the fiber is fully impregnated to improve the strength and durability of the composite material.

[0059] (3) Winding of the Rigid Core 3: Under controlled tension and a predetermined linear shape, the impregnated fiber is longitudinally wound around the core mold in a certain pattern. The winding method is to wind one coil through a semicircular steel ring, and then wrap another coil, and so on until the required number of coils is reached.

[0060] (4) Winding of the protective layer 4, i.e., the surface splitting-resistant layer: Under conditions of controlled tension and predetermined linear shape, the impregnated carbon fibers are transversely wound on the rigid core layer 3 in an S-shaped spiral.

[0061] (5) Curing treatment: The wound composite material pull ring is cured at a certain temperature to fully cure the resin and form a stable composite material structure.

[0062] (6) Demolding and trimming: After curing is completed, the composite material pull ring is removed from the core mold and necessary trimming and processing are performed to meet the use requirements.

[0063] The fibers of the core layer 3 can be any kind of fibers such as carbon fibers, glass fibers, Kevlar fibers, PBO fibers, etc., and the fiber content is controlled within the range of 50% to 70%.

[0064] The carbon fiber of the surface splitting resistant layer can be any type of T300, T700, T800, and T1000, and its multidimensional fabric can adopt a two-dimensional fabric laminate structure, wherein the single layer in the two-dimensional fabric laminate structure can be any one or more combinations of plain, twill, and satin.

[0065] The carbon fiber fabric fiber specification is any one of 3K, 6K, 12K, 24K or 36K.

[0066] The resin glue can adopt a thermosetting resin system (resistant to high and low temperatures, medium and normal temperature curing, high strength, high toughness), or an in-situ polymerization thermoplastic resin system.

[0067] The thermosetting resin may be any one of epoxy resin, unsaturated polyester resin, phenolic resin, urea-formaldehyde resin, etc. and is not limited to the above types. The thermoplastic resin may be any one of polyamide resin, polyacrylic resin, etc. and is not limited to the above types.

[0068] The winding thickness of the core layer 3 is between 5 and 20 mm.

[0069] The thickness of the splitting-resistant layer on the surface of the composite material is between 0.5 and 5 mm, and the width of the winding narrow strip is between 5 and 50 mm.

[0070] The pull ring of the present invention is made of fiber-reinforced composite material by winding, and its weight is reduced by 40% or more compared with the same type of steel pull ring.

[0071] The pull ring is prepared by a composite winding process, which effectively guarantees the overall mechanical properties of the pull ring.

[0072] The performance of composite pull rings can be optimized by adjusting the arrangement of fibers and the type of resin to meet different usage requirements.

[0073] The present invention utilizes a combined linear and S-shaped spiral winding process to manufacture a composite pull ring. This method addresses the relatively heavy steel pull rings currently on the market and achieves the goal of lightweight pull rings. The composite pull ring comprises a winding core mold, a winding core layer (3), and a winding surface splitting-resistant layer.

[0074] Core mold preparation: Two cylindrical coils 1 and a semicircular steel ring are mounted on a winding core mold frame to form the winding core mold. Ensure the core mold surface is smooth and flat to facilitate fiber winding and demolding after curing. Fiber impregnation: Continuous fibers are impregnated with a resin adhesive to ensure full fiber saturation, enhancing the composite's strength and durability. Core layer 3 winding: Under controlled tension and a predetermined linear profile, the impregnated fibers are longitudinally wound around the core mold in a specific pattern. The winding process begins with one coil, then passes through a semicircular steel ring, and then wraps around another coil, repeating this process until the desired number of turns is reached. Surface split-resistant layer winding: Under controlled tension and a predetermined linear profile, the impregnated carbon fibers are transversely wound in an S-shaped spiral pattern around the rigid core film layer. Curing: The wound composite ring is cured at a specific temperature to fully cure the resin and form a stable composite structure. Demolding and finishing: After curing, the composite ring is removed from the core mold and subjected to necessary finishing and processing to meet application requirements.

[0075] Compared to traditional steel pull tabs, composite pull tabs offer the following advantages: Lightweight: Composite pull tabs are lighter than steel pull tabs, which helps reduce overall product weight, improve transportation efficiency, and reduce energy consumption. Corrosion resistance: Composite pull tabs are typically made of resin-based composite materials, offering excellent corrosion resistance and resistance to a variety of chemical agents, extending their service life. High strength: Despite their lighter weight, composite pull tabs are comparable in strength to steel pull tabs, and in some cases even surpass them. Designability: Composite pull tabs can optimize their performance by adjusting the fiber arrangement and resin type to meet diverse application requirements. Using a winding process to manufacture composite pull tabs as a replacement for traditional steel pull tabs is a promising innovation. With continuous technological advancements and decreasing costs, composite pull tabs are expected to find widespread application in even more areas. In the future, we can expect the emergence of more innovative composite production technologies and solutions to meet the needs and challenges of diverse industries.

[0076] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of the claims of the present invention to be approved.

Claims

1. A pull ring, characterized in that: From the inside to the outside, it includes: a core mold, a core layer (3) and a protective layer (4); The core mold comprises: two cylindrical coils (1) with their axes collinear with a first axis at one end, and a semi-cylindrical coil (2) with its rotation axis perpendicular to the first axis at the other end, wherein both ends of the semi-cylindrical coil (2) respectively point to the two cylindrical coils (1); The core layer (3) is wound on the surface of the core mold in a predetermined linear shape along the longitudinal direction to form an intermediate transition layer; The protective layer (4) is transversely wound on the surface of the core layer (3) in an S-shaped spiral track.

2. A pull ring according to claim 1, characterized in that: The core layer (3) comprises continuous fibers impregnated with resin glue.

3. A pull ring according to claim 1, characterized in that: The protective layer (4) comprises: carbon fiber fabric impregnated with resin glue.

4. A pull ring according to claim 2, characterized in that: The continuous fiber includes any one of carbon fiber, glass fiber, Kevlar and PBO fiber.

5. A pull ring according to claim 4, characterized in that: The fiber content in the pull ring is 50% to 70%.

6. A pull ring according to claim 3, characterized in that: The carbon fiber includes: one of T300, T700, T800 and T1000.

7. A pull ring according to claim 3, characterized in that: Each layer of the carbon fiber fabric structure includes at least one of plain weave, twill weave and satin weave.

8. A pull ring according to claim 7, characterized in that: The fiber specifications of the carbon fiber fabric include: any one of 3K, 6K, 12K, 24K or 36K.

9. A pull ring as claimed in claims 2 and 3, characterized in that: The resin glue comprises any one of a thermosetting epoxy resin system and an in-situ polymerized thermoplastic resin system.

10. A pull ring according to claim 9, characterized in that: The properties of the thermosetting epoxy resin system include any one of high and low temperature resistance, medium and normal temperature curing, high strength, and high toughness.

11. The pull ring according to claim 9, characterized in that: The thermosetting resin may be any one of epoxy resin, unsaturated polyester resin, phenolic resin, urea-formaldehyde resin and the like.

12. The pull ring according to claim 9, characterized in that: The thermoplastic resin includes any one of polyamide resin, polyacrylic resin and the like.

13. A method for preparing a pull ring according to any one of claims 1 to 12, characterized in that: The following steps are involved: Two cylindrical coils (1) and a semi-cylindrical coil (2) are mounted on a ring-shaped winding core mold frame to form a core mold; Dipping the continuous fiber into the resin glue solution to fully wet it to form a first intermediate; Winding the first intermediate longitudinally between the cylindrical coil (1) and the semi-cylindrical coil (2) to form a core layer (3); The protective layer (4) transversely winds the impregnated carbon fibers onto the core layer (3) to form a second intermediate; solidifying the second intermediate to obtain a third intermediate; The third intermediate is removed from the core mold, corrected and processed to obtain a final pull ring.

14. A pull ring according to claim 13, characterized in that: The thickness of the core layer (3) wrapped around the core mold is 5 to 20 mm.

15. The pull ring according to claim 13, characterized in that: The protective layer (4) is wrapped around the core layer (3) with a narrow strip width of 5 to 50 mm.

16. The pull ring according to claim 13, characterized in that: The thickness of the protective layer (4) wrapped around the core layer (3) ranges from 0.5 to 5 mm.

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