A mold and manufacturing process for thermoplastic carbon fiber composite bolts

Abstract

This invention relates to the field of thermoplastic carbon fiber composite bolt processing technology, and provides a mold and manufacturing process for manufacturing thermoplastic carbon fiber composite bolts. It includes: an upper mold and a lower abrasive, which, when closed, form a first cavity and a second cavity; an upper wedge-shaped module and a lower wedge-shaped module, or a pressing module alone, are inserted into the first cavity; the upper and lower wedge-shaped modules are fixed to the upper mold and the lower abrasive by a first bolt and a second bolt, respectively; when the upper and lower wedge-shaped modules are removed from the first cavity, the pressing module is pressed into the first cavity; the portion of the upper mold and the lower abrasive located in the second cavity has a threaded structure. The beneficial effect is that the continuous carbon fiber at the thread only undergoes slight deformation in the radial direction of the bolt, ensuring a sufficient and uniform distribution of carbon fiber inside the thread, and preventing fiber breakage.

Description

Technical Field

[0001] This invention relates to the field of thermoplastic carbon fiber composite bolt processing technology, specifically to a manufacturing mold and process for thermoplastic carbon fiber composite bolts. Background Technology

[0002] The molding and manufacturing methods and processes for thermosetting carbon fiber composite bolts are relatively mature. However, for thermoplastic carbon fiber composites, especially those using high-performance thermoplastic resins such as polyetherimide (PEI), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), and low-density polyaryletherketone (LMPAEK) as the matrix, certain problems and limitations still exist in their molding and manufacturing. Existing technologies use rod-shaped continuous carbon fiber reinforced composite materials as raw materials and employ a flow extrusion technique, as shown in the attached... Figure 6 As shown, a heated bar is slowly pressed into a bolt-shaped mold cavity. During this process, continuous fibers and thermoplastic resin melt flow and deform, and the fibers move and arrange themselves axially at the threads, forming a bolt with continuous fiber reinforcement. This process has strict requirements on extrusion speed, bar temperature, and mold temperature. Deviations in any parameter will result in no reinforcing fibers at the threads or the fibers being broken and damaged. Furthermore, the optimal extrusion speed is very slow and the process window is very narrow, resulting in low production efficiency and yield.

[0003] Furthermore, flow extrusion technology is not suitable for smaller bolts or bolts with long threaded sections. Moreover, for high-performance composites such as continuous fiber reinforced PEEK and PEKK, the processing cost of rod-shaped raw materials is very expensive, presenting a high technological barrier. Currently, only a few European and American companies possess this technology. Other applications of flow extrusion for bolt forming generally use square-section strip composites that are machined into rods, further increasing costs and generating a large amount of waste.

[0004] Therefore, this invention is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a mold and manufacturing process for thermoplastic carbon fiber composite bolts, so as to solve the technical problems existing in the prior art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a thermoplastic carbon fiber composite bolt manufacturing mold, comprising: an upper mold and a lower mold, wherein the upper mold and the lower mold, after being closed, form a first cavity and a second cavity; an upper wedge-shaped module and a lower wedge-shaped module for cooperation are inserted into the first cavity, or a lower pressing module is inserted separately; the upper wedge-shaped module and the lower wedge-shaped module are respectively fixed to the upper mold and the lower mold by a first bolt and a second bolt; when the upper wedge-shaped module and the lower wedge-shaped module are removed from the first cavity, the lower pressing module is pressed into the first cavity; the portion of the upper mold and the lower mold located in the second cavity has a threaded structure.

[0007] In an optional embodiment, the cross-sections of both the first cavity and the second cavity are circular, and the first cavity is a trapezoidal cavity with a cross-sectional area that gradually decreases inward.

[0008] In an optional embodiment, the pressing module is provided with a top block, which is quadrilateral, hexagonal, or quincunx-shaped.

[0009] On the other hand, another embodiment of the invention provides a manufacturing process for thermoplastic carbon fiber composite bolts, using the thermoplastic carbon fiber composite bolt manufacturing mold as described above, including the following steps:

[0010] S1: Prepare a continuous carbon fiber reinforced thermoplastic composite material plate, and cut long strips of the composite material from the continuous carbon fiber reinforced thermoplastic composite material plate;

[0011] S2: The wedge module and the lower wedge module are fixedly installed on the upper mold and the lower mold respectively. The composite strip is then placed in the upper mold and the lower mold with a threaded structure. The strip is then placed together between the upper and lower plates of the flat vulcanizing machine for heating. The flat vulcanizing machine applies pressure to the upper mold and slowly closes the mold to form a workpiece with threads.

[0012] S3: Take out the upper wedge module and the lower wedge module, and slowly press the lower pressing module and the top block into the first cavity and press it into the top of the threaded workpiece to form a bolt head;

[0013] S4: After cooling, open the mold and remove the continuous fiber reinforced thermoplastic carbon fiber composite bolt.

[0014] In an optional embodiment, in S1, the composite strip is cut from the continuous carbon fiber reinforced thermoplastic composite plate using a water jet cutter, a precision abrasive wheel cutter, or a laser cutter.

[0015] In an optional embodiment, the carbon fibers of the composite strip are arranged unidirectionally along its length, and the cross-sectional area of ​​the composite strip is equal to the cross-sectional area of ​​the threaded workpiece to be formed.

[0016] In an optional embodiment, in S2, after the temperature is raised to between 0-40°C above the melting temperature of the continuous carbon fiber reinforced thermoplastic composite board, the flat vulcanizing machine applies pressure to the upper mold.

[0017] In an optional embodiment, in S3, the top block is pressed down after the temperature of the threaded workpiece is between 0-40°C above the melting temperature of the thermoplastic carbon fiber composite plate.

[0018] In an optional embodiment, the external shape of the bolt head is circular, hexagonal, or quadrilateral.

[0019] The beneficial effects of this invention are as follows:

[0020] (1) In the process of molding thermoplastic composite thread using the compression molding method of this invention, the continuous carbon fibers at the thread only undergo slight deformation in the radial direction of the bolt. In contrast, in the existing extrusion flow molding process, the carbon fibers undergo significant movement and continuous bending deformation along the axial direction of the bolt under pressure. Therefore, this invention can better ensure that there is a sufficient and uniform distribution of carbon fibers inside the thread, and the fibers will not break or be damaged. In addition, compared with the extrusion flow process, the entire molding process is shorter and more efficient.

[0021] (2) The present invention uses rectangular thermoplastic carbon fiber composite strips as raw materials for processing bolts. These raw materials can be directly obtained by cutting thermoplastic composite flat plates. Compared with the rod-shaped carbon fiber composites used in the prior art, the cost is greatly reduced. In particular, the cross-sectional area of ​​the cut composite strips is equal to the cross-sectional area of ​​the threaded workpiece to be formed, which ensures the quality of thread forming and does not waste raw materials. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of a continuous carbon fiber reinforced thermoplastic composite material plate provided in one embodiment of the present invention.

[0024] Figure 2 This is a schematic diagram of the cutting of a continuous carbon fiber reinforced thermoplastic composite plate provided in one embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram of obtaining a threaded workpiece according to one embodiment of the present invention. Figure 1 .

[0026] Figure 4 This is a schematic diagram of obtaining a threaded workpiece according to one embodiment of the present invention. Figure 2 .

[0027] Figure 5 This is a schematic diagram of obtaining a continuous fiber-reinforced thermoplastic carbon fiber composite bolt according to an embodiment of the present invention.

[0028] Figure 6 This is a schematic diagram of the extrusion molding of rod-shaped continuous carbon fiber reinforced composite materials in the prior art.

[0029] The attached figures are labeled as follows:

[0030] 1-Continuous carbon fiber reinforced thermoplastic composite plate, 2-Composite strip, 3-Upper mold, 4-Lower mold, 5-Threaded workpiece, 6-Upper wedge module, 7-Lower wedge module, 8-First bolt, 9-Second bolt, 10-Top block, 11-Pressing module, 12-Continuous fiber reinforced thermoplastic carbon fiber composite bolt. Detailed Implementation

[0031] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0032] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it may be directly or indirectly located on that other component. When a component is referred to as "connected to" another component, it may be directly or indirectly connected to that other component. The terms "upper," "lower," "left," "right," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate orientations or positions based on the accompanying drawings, and are for ease of description only, and should not be construed as limiting the technical solution. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. "A plurality" means two or more, unless otherwise explicitly defined.

[0033] Example 1

[0034] Please see the appendix Figure 1-5The purpose of this embodiment is to provide a manufacturing mold for thermoplastic carbon fiber composite bolts, including: an upper mold 3 and a lower abrasive 4. After the upper mold 3 and the lower abrasive 4 are closed, a first cavity and a second cavity are formed. An upper wedge-shaped module 6 and a lower wedge-shaped module 7 are inserted into the first cavity for cooperation, or a lower pressing module 11 is inserted alone. The cross-sections of the first cavity and the second cavity are both circular, and the first cavity is a trapezoidal cavity with a cross-sectional area that gradually decreases inward.

[0035] Specifically, the upper wedge-shaped module 6 and the lower wedge-shaped module 7 are fixed to the upper mold 3 and the lower grinding mold 4 respectively by the first bolt 8 and the second bolt 9; after the upper wedge-shaped module 6 and the lower wedge-shaped module 7 are removed from the first cavity, the lower pressing module 11 is pressed into the first cavity. The upper mold 3 and the lower grinding mold 4 have threaded structures in the second cavity portion, which are used to form the threaded portion of the bolt. The lower pressing module 11 is provided with a top block 10, which is quadrilateral, hexagonal, or star-shaped, for internal extrusion forming of the bolt head.

[0036] Example 2

[0037] Please see the appendix Figure 1-5 The purpose of this embodiment is to provide a manufacturing process for thermoplastic carbon fiber composite bolts, using the thermoplastic carbon fiber composite bolt manufacturing mold as described in the above embodiment, including the following steps:

[0038] S1: Prepare a continuous carbon fiber reinforced thermoplastic composite material plate 1, and cut long strips 2 from the continuous carbon fiber reinforced thermoplastic composite material plate 1. Preferably, the long strips 2 are cut from the continuous carbon fiber reinforced thermoplastic composite material plate 1 using a water jet cutter, a precision abrasive wheel cutter, or a laser cutter. Using long strips of carbon fiber composite material with a rectangular cross-section as the raw material for processing bolts, this raw material can be directly obtained from the composite material plate, which greatly reduces the cost compared with the rod-shaped carbon fiber composite material used in the prior art.

[0039] S2: Wedge-shaped modules 6 and 7 are fixedly installed on the upper mold 3 and lower mold 4 respectively. Then, the composite strip 2 is placed in the upper mold 3 and lower mold 4 with threaded structure. Then, they are placed together between the upper and lower plates of the flat vulcanizing machine for heating. After the temperature rises to 0-40°C above the melting temperature of the continuous carbon fiber reinforced thermoplastic composite board, the flat vulcanizing machine applies pressure to the upper mold 3 and slowly closes the mold to form a threaded workpiece 5. The carbon fibers of the composite strip 2 are arranged unidirectionally along its length direction. The cross-sectional area of ​​the composite strip 2 is equal to the cross-sectional area of ​​the threaded workpiece 5 to be formed, ensuring high-quality forming of the thread and avoiding waste of raw materials.

[0040] S3: Remove the upper wedge module 6 and the lower wedge module 7, and slowly press the lower pressing module 11, along with the top block 10, into the first cavity and press it into the top of the threaded workpiece 5 to form a bolt head. It should be noted that the top block 10 is pressed down after the temperature of the threaded workpiece 5 is between 0-40°C above the melting temperature of the thermoplastic carbon fiber composite board. The external shape of the bolt head is circular, hexagonal, or quadrilateral.

[0041] It should be noted that during the molding process of the thread, the continuous carbon fibers at the thread only undergo slight deformation in the radial direction of the bolt. In contrast, during existing extrusion flow molding processes, the carbon fibers undergo significant movement and continuous bending deformation along the axial direction of the bolt under pressure. Therefore, this invention is better able to ensure a sufficient and uniform distribution of carbon fibers inside the thread, without fiber breakage. Please refer to the appendix. Figure 5 Furthermore, compared to extrusion flow processes, compression molding is a shorter and more efficient molding process.

[0042] Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention shall be included within the scope of protection of this invention.

Claims

1. A mold for manufacturing thermoplastic carbon fiber composite bolts, characterized in that, include: An upper mold (3) and a lower mold (4) are provided. After the upper mold (3) and the lower mold (4) are closed, they form a first cavity and a second cavity. An upper wedge-shaped module (6) and a lower wedge-shaped module (7) are inserted into the first cavity for use. The upper wedge-shaped module (6) and the lower wedge-shaped module (7) are fixed to the upper mold (3) and the lower mold (4) respectively by a first bolt (8) and a second bolt (9). When the upper wedge-shaped module (6) and the lower wedge-shaped module (7) are removed from the first cavity, the lower pressing module (11) is pressed into the first cavity. The upper mold (3) and the lower mold (4) located in the second cavity have a threaded structure. Both the first cavity and the second cavity have circular cross-sections, and the first cavity is a trapezoidal cavity with a cross-sectional area that gradually decreases inward. The process of manufacturing thermoplastic carbon fiber composite bolts using the aforementioned mold includes the following steps: S1: Prepare a continuous carbon fiber reinforced thermoplastic composite board (1) and cut a composite strip (2) from the continuous carbon fiber reinforced thermoplastic composite board (1); S2: The wedge module (6) and the lower wedge module (7) are fixedly installed on the upper mold (3) and the lower mold (4) respectively. Then, the composite strip (2) is placed in the upper mold (3) and the lower mold (4) with threaded structure. Then, they are placed together between the upper and lower plates of the flat vulcanizing machine for heating. The flat vulcanizing machine applies pressure to the upper mold (3) and slowly closes the mold to form a workpiece (5) with thread. S3: Take out the upper wedge module (6) and the lower wedge module (7), and slowly press the lower pressing module (11) and the top block (10) into the first cavity and press them into the top of the threaded workpiece (5) to form a bolt head; S4: After cooling, open the mold and remove the continuous fiber reinforced thermoplastic carbon fiber composite bolt (1); In S1, the composite strip (2) is cut from the continuous carbon fiber reinforced thermoplastic composite plate (1) by water jet, precision abrasive wheel cutting machine or laser cutting machine; the carbon fibers of the composite strip (2) are arranged unidirectionally along its length direction, and the cross-sectional area of ​​the composite strip (2) is equal to the cross-sectional area of ​​the threaded workpiece (5) to be formed.

2. The thermoplastic carbon fiber composite bolt manufacturing mold as described in claim 1, characterized in that, The pressing module (11) is provided with a top block (10), which is quadrilateral, hexagonal or plum blossom shaped.

3. The thermoplastic carbon fiber composite bolt manufacturing mold as described in claim 1, characterized in that, In S2, after the temperature is raised to between 0-40°C above the melting temperature of the continuous carbon fiber reinforced thermoplastic composite board, the flat vulcanizing machine applies pressure to the upper mold (3).

4. The thermoplastic carbon fiber composite bolt manufacturing mold as described in claim 1, characterized in that, In S3, the top block (10) is pressed down after the temperature of the threaded workpiece (5) is between 0-40°C above the melting temperature of the thermoplastic carbon fiber composite plate.

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