Method for manufacturing thermoplastic composite bicycle frame

Abstract

The present invention discloses a method for manufacturing a thermoplastic composite bicycle frame, which mainly includes a shell forming step, a shell joining step, and a mold hot pressing forming step. In the shell forming step, each shell has corresponding straight segments and bent segments. In the shell joining step, the shells are joined and assembled so that the straight segment joining edges of the shells are staggered and overlapped, and the bent segment joining edges of the shells are abutted against each other. In this way, stress concentration problems at the bends of the frame can be effectively eliminated and subsequent reinforcement is facilitated. The staggered and overlapping straight segment joining edges facilitate the positioning of the two shells in the joined assembly.

Description

Technical Field

[0001] The present invention relates to a forming technology for bicycle frame components, in particular to a forming method for bicycle thermoplastic composite material frame components formed by thermoplastic composite materials in a hot pressing bonding manner. Background Art

[0002] The existing thermoplastic composite bicycle frame forming method combines multiple shells into a frame component through hot pressing, thereby improving the mass production of thermoplastic composite bicycle frames.

[0003] However, existing thermoplastic composite bicycle frame molding methods address stress concentration at the frame's bends by dividing the frame into multiple units and then combining them into frame components. This method is complex and cannot directly produce a complete frame component. Therefore, existing thermoplastic composite bicycle frame molding methods have shortcomings and require improvement. Summary of the Invention

[0004] To address the shortcomings of existing thermoplastic composite bicycle frame molding methods, the present invention provides a method for molding bicycle thermoplastic composite frame components. By overlapping the shell components and hot pressing, the above-mentioned problems are effectively improved, as further described below.

[0005] The method for manufacturing a thermoplastic composite bicycle frame of the present invention comprises:

[0006] The step of forming a shell component comprises hot pressing a thermoplastic composite sheet material with a mold to form two or more shell components capable of being mated with each other, wherein each shell component comprises a shell groove formed by the shell component, at least one straight line segment and at least one bent segment connected to each other, wherein the straight lines of the shell components correspond to each other, and the bent segments of the shell components correspond to each other, wherein the straight lines have straight line segment abutting edges, and the bent segments have bent segment abutting edges;

[0007] a shell member docking step: docking the shell members so that the straight segments of the shell members are overlapped and staggered, and the bent segments of the shell members are abutted and not overlapped; and

[0008] Mold hot pressing forming step: using a mold hot pressing forming method, the straight segment butt edges of the overlapping shell parts and the bent segment butt edges that abut each other are hot pressed to form a welded zone connected into one body, so that the shell parts are joined to form a vehicle frame member.

[0009] In the above-mentioned method for manufacturing a thermoplastic composite bicycle frame, in the shell forming step, the thermoplastic composite sheet material is a thermoplastic carbon fiber sheet material or a thermoplastic glass fiber sheet material.

[0010] Furthermore, the above-mentioned thermoplastic composite bicycle frame manufacturing method includes a reinforcement step: attaching a reinforcement material to at least one of the inner side and the outer side of the abutting edge of the bent section of the abutted shell components, and curing the reinforcement material in a mold hot pressing step.

[0011] Furthermore, in the above-mentioned thermoplastic composite bicycle frame manufacturing method, in the shell component forming step, each shell component forms a transition section between the adjacent straight segment abutting edges and the bent segment abutting edges; in the shell component abutting step, the transition sections of the two shell components partially abut against each other and are partially dislocated.

[0012] Furthermore, the above-mentioned thermoplastic composite bicycle frame manufacturing method includes a reinforcement step: attaching a reinforcement material to at least one of the inner side and the outer side of the abutting edge of the bent section of the two abutting shell components, with the reinforcement material covering the transition section, and curing the reinforcement material during a mold hot pressing step.

[0013] Furthermore, in the above-mentioned thermoplastic composite bicycle frame manufacturing method, in the shell forming step, the length of the transition section is between 10 and 100 mm, inclusive.

[0014] Preferably, in the above-mentioned method for manufacturing a thermoplastic composite bicycle frame, before the mold hot pressing step, an inner support member capable of supporting each shell member is disposed inside the frame member formed by the two shell members. After the mold hot pressing step, the inner support member located inside the frame member is removed, and the frame member is manufactured into a finished product by means of trimming and finishing.

[0015] By virtue of the above technical features, the technical effects of the present invention are as follows:

[0016] 1. Since stress is easily concentrated at the bends of thermoplastic composite bicycle frames during the molding process, the abutment of the two shells' bent sections at their edges can effectively eliminate stress at the bends, control the appearance of the frame components with a higher yield, facilitate the production of more complete frame components, and reduce the number of steps required to combine multiple frame units.

[0017] 2. Since the bends of the thermoplastic composite bicycle frame are the parts that need special structural reinforcement, the bent sections of the shell members abut against each other with the bent section butt edges, which can effectively avoid yarn pinching and yarn folding, and is conducive to subsequent reinforcement.

[0018] 3. The bent sections of the shell components are butted against each other with their butt edges, and the straight sections with lower stress elimination and reinforcement requirements are staggered and overlapped with their butt edges, so as to facilitate the positioning of the two shell components. The straight sections and the bent sections can respectively facilitate positioning, eliminate stress, and facilitate reinforcement, thereby jointly improving the quality of the vehicle frame component products.

[0019] 4. The length of the transition section is between 10 and 100 mm, effectively connecting the straight section and the bent section, thereby preventing interference between the straight section and the bent section of the two shells. This increases the feasibility of the thermoplastic composite bicycle frame manufacturing method of the present invention and prevents the transition section from being too long, which would increase the difficulty of positioning the frame components or reduce the structural strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the shell forming steps of a preferred embodiment of the present invention.

[0021] Figure 2 Schematic diagram of the exploded view of the two shells of a preferred embodiment of the present invention.

[0022] Figure 3 This is a three-dimensional appearance diagram of the shell docking assembly of a preferred embodiment of the present invention.

[0023] Figure 4 It is a partially enlarged side view of the shell docking assembly of a preferred embodiment of the present invention.

[0024] Figure 5 For the Figure 4 Cross-section diagram of the AA cutting line.

[0025] Figure 6 For the Figure 5 Cross-section diagram of the BB cutting line.

[0026] Figure 7 for Figure 4 A top view of a locally enlarged portion.

[0027] Figure 8 Schematic diagram of the reinforcement step and mold hot pressing step.

[0028] Figure 9 For the Figure 7 Cross-sectional view of the CC cutting line. DETAILED DESCRIPTION

[0029] In order to understand the technical features and practical effects of the present invention in detail and to implement them according to the contents of the specification, the preferred embodiments shown in the drawings are further described in detail as follows:

[0030] The present invention provides a method for manufacturing a thermoplastic composite bicycle frame, which mainly includes: a shell forming step, a shell joining step, and a mold hot pressing forming step. The frame manufacturing method of the present invention can be applied to directly produce a complete bicycle frame. The preferred embodiment thereof is as follows: Figures 1 to 9 As shown, further details are given below.

[0031] Shell molding steps: Please refer to Figure 1 and Figure 2 As shown, the present invention separates a pre-formed vehicle frame member 20 into two mateable shell members 20A and 20B by splitting the pre-formed vehicle frame member 20 into two halves. During the shell member forming step, a thermoplastic composite sheet 10 made of a thermoplastic carbon fiber material or a thermoplastic glass fiber material is selected and hot-pressed into the shell members 20A and 20B using a mold hot-pressing method with appropriate trimming and finishing techniques.

[0032] like Figure 2 As shown, each of the shell members 20A and 20B includes a shell groove 21A and 21B formed by the shell members 20A and 20B, at least one interconnected straight line segment 22A and 22B, and at least one bent segment 23A and 23B. The straight line segments 22A and 22B of the two shell members 20A and 20B correspond to each other, and the bent segments 23A and 23B of the two shell members 20A and 20B correspond to each other. In a preferred embodiment of the present invention, each of the shell members 20A and 20B includes multiple straight line segments 22A and 22B and multiple bent segments 23A and 23B. For example, the straight line segments 22A and 22B include primarily straight portions of the frame member 20, such as the top tube and down tube. The bent segments 23A and 23B include bent portions, such as the connection between the head tube and the top tube, the connection between the head tube and the down tube, the connection between the top tube and the seat tube, and the connection between the seat tube and the motor mount. For further information, see Figures 4 to 7 As shown, the straight segments 22A and 22B have straight segment abutting edges 221A and 221B for combining the two shells 20A and 20B, and the bent segments 23A and 23B have bent segment abutting edges 231A and 231B for combining the two shells 20A and 20B.

[0033] Shell docking assembly steps: Figures 2 to 4 and Figure 7 As shown, the two shells 20A and 20B are joined together so that the straight-line joint edges 221A and 221B of the two shells 20A and 20B overlap and the bent-section joint edges 231A and 231B of the two shells 20A and 20B abut against each other, that is, the end edges of the bent-section joint edges 231A and 231B completely overlap. Figure 5 As shown in the preferred embodiment of the present invention, the two shells 20A and 20B are arranged such that the straight segment abutting edge 221B of the straight segment 22B of one shell 20B is inserted into the shell groove 21A of the other shell 20A, so that the straight segment abutting edges 221A and 221B of the two shells 20A and 20B overlap each other. Figure 6As shown, the bent sections of the two shells 20A and 20B form a butt joint (a "butt joint"), allowing the edges of the bent sections 23A and 23B of the two shells 20A and 20B to abut against each other without extending into the housing grooves 21A and 21B of the opposing shells 20A and 20B. Through the above steps, the two shells 20A and 20B are butted together to form a preliminary structure for various parts of the bicycle frame, including but not limited to a top tube 25', a seat tube 26', a down tube 27', a motor bracket 28', and a head tube 29'. These parts are then hot-pressed in a mold to form the top tube, seat tube, down tube, motor bracket, and head tube of the bicycle frame.

[0034] In the embodiment shown in the figure, to allow the straight abutting edges 221A and 221B of the two shells 20A and 20B to overlap, the side edges of the straight abutting edges 221A and 221B extend approximately 2.5 to 6 mm beyond the bisecting line of the frame member 20. This allows the corresponding straight abutting edges 221A and 221B to overlap by approximately 5 to 12 mm when the two shells 20A and 20B are joined. In other embodiments, the present invention can separate the prefabricated frame member into three or more mutually joinable shells. The present invention does not impose any specific restrictions on the number of separate shells, as long as the straight and curved segments of the shells possess the technical features defined in the present invention. In the embodiment shown in the figure, the overlapping width of the corresponding straight abutting edges 221A and 221B is approximately 8 mm.

[0035] Mold hot pressing steps: Please refer to Figure 8 As shown, the two shell members 20A and 20B are staggered and overlapped by a mold hot pressing method, and the straight segment butt edges 221A and 221B and the bent segment butt edges 231A and 231B that abut against each other are formed into a welded zone by hot pressing and welding, so that the two shell members 20A and 20B are joined to form the vehicle frame member 20.

[0036] Because the bent sections 23A and 23B of the thermoplastic composite bicycle frame are susceptible to stress concentration during the molding process, the two shells 20A and 20B are joined together by having their bent section abutting edges 231A and 231B abut each other rather than overlapping each other. This effectively eliminates stress at the frame bend, controls the appearance of the frame component with a higher yield, facilitates the production of a more complete frame component, and reduces the number of frame unit assembly processes. Furthermore, the aforementioned technical features, combined with the staggered overlapping of the straight sections 22A and 22B, which require less stress elimination and reinforcement, with their straight section abutting edges 221A and 221B, facilitate the positioning of the two shells 20A and 20B during the assembly. This allows the straight sections 22A and 22B and the bent sections 23A and 23B to enhance the quality of the frame component by facilitating positioning and stress elimination, and facilitating reinforcement, respectively.

[0037] Further, if Figure 8 As shown, before the hot press molding step, an inner support member 30 is positioned within the interior of the frame member 20A, 20B to support the frame members 20A, 20B. After the hot press molding step, the inner support member 30 is removed from the frame member, and trimming is performed to complete the finished frame member. The inner support member 30 can be a metal core mold, a foam core mold, a wax core mold, or an air bag, among other suitable support members, and the present invention is not particularly limited thereto.

[0038] Furthermore, in a preferred embodiment of the present invention, the method for manufacturing a thermoplastic composite bicycle frame further includes a reinforcing step: attaching a reinforcing material 40 to at least one of the inner side and the outer side of the bending section abutting edges 231A, 231B of the two abutting shells 20A, 20B, preferably, as shown in FIG. Figure 8 As shown, reinforcing material 40 is attached to the inner and outer sides of the bending section butt joint edges 231A, 231B, and is cured in the mold hot pressing step. The material of the reinforcing material 40 is conventional, so it will not be described in detail here.

[0039] In this way, in order to prevent the frame member 20 from being damaged by the structurally fragile bending sections 23A and 23B, the structural strength can be improved by the reinforcing material 40. If the bending section butt edges are combined in an interlaced and overlapping manner, during the mold hot pressing step, the bending section butt edges will form a thicker weld zone and a step difference, making the reinforcing material 40 prone to yarn pinching and yarn folding. Yarn pinching refers to the reinforcing material 40 being clamped by the mold to form an outward protruding excess material; yarn folding refers to the reinforcing material 40 being folded inward to form excess material. Both yarn pinching and yarn folding will cause defects in the finished product and require reprocessing to correct the defects. However, the present invention effectively avoids yarn pinching and yarn folding by abutting the bending sections 23A and 23B of the shell members 20A and 20B with the bending section butt edges 231A and 231B instead of interlacing and overlapping, which is beneficial for subsequent reinforcement.

[0040] Preferably, see Figure 4 、 Figure 7 and Figure 9 As shown, in the shell forming step, each shell 20A, 20B forms a transition section 24A, 24B between the adjacent straight section butt edges 221A, 221B and the bent section butt edges 231A, 231B; in the shell butt joint step, as shown Figure 9 As shown, the transition sections 24A and 24B of the two shells 20A and 20B partially abut against each other. Figure 9 The right end areas of the transition sections 24A and 24B shown in FIG. 2 are partially in contact with each other, and the transition sections 24A and 24B of the two shells 20A and 20B are partially in a non-staggered and non-abutting state. Figure 9 The left end areas of the transition sections 24A and 24B are shown. Furthermore, the lengths L and L' of the transition sections 24A and 24B range from 10 to 100 mm, inclusive, effectively connecting the straight section butt edges 221A and 221B with the bent section butt edges 231A and 231B, preventing interference between the straight section butt edges 221A and 221B and the bent section butt edges 231A and 231B of the two shells 20A and 20B. This enhances the feasibility of the thermoplastic composite bicycle frame manufacturing method of the present invention and prevents excessive length of the transition sections 24A and 24B, which would increase the difficulty of positioning the frame member 20 or reduce the structural strength. Preferably, in a preferred embodiment of the present invention, the lengths L and L' of the transition sections 24A and 24B range from 30 to 50 mm, further enhancing the aforementioned advantageous effects. During the reinforcement step, the reinforcing material 40 covers the transition sections 24A and 24B.

[0041] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any person with ordinary knowledge in the technical field can make equivalent embodiments by making partial changes or modifications to the technical content disclosed in the present invention without departing from the scope of the technical solution of the present invention, and the equivalent embodiments still fall within the scope of the technical solution of the present invention without departing from the technical solution of the present invention.

Claims

1. A method for manufacturing a thermoplastic composite bicycle frame, characterized in that: include: The step of forming a shell is as follows: hot pressing the thermoplastic composite sheet material with a mold to form two or more shells that can be matched with each other, each shell comprising a shell groove formed by the shell, at least one straight line segment and at least one bent segment connected to each other, the straight lines of the two or more shells corresponding to each other, and the bent segments of the two or more shells corresponding to each other, the straight lines having straight line segment abutting edges, and the bent segments having bent segment abutting edges; a shell member docking step: docking the shell members so that the straight segments of the shell members are overlapped and staggered, and the bent segments of the shell members are abutted and not overlapped; and Mold hot pressing forming step: using a mold hot pressing forming method, the straight segment butt edges of the overlapping shell parts and the bent segment butt edges that abut each other are hot pressed to form a welded zone connected into one body, so that the shell parts are joined to form a vehicle frame member.

2. The method for manufacturing a thermoplastic composite bicycle frame according to claim 1, wherein: In the shell forming step, the thermoplastic composite plate is a thermoplastic carbon fiber plate or a thermoplastic glass fiber plate.

3. The method for manufacturing a thermoplastic composite bicycle frame according to claim 1, wherein: The method further includes a reinforcing step: attaching a reinforcing material to at least one of the inner side and the outer side of the butt joint edge of the bent section of the butt joint shell components, and curing the reinforcing material in a mold hot pressing step.

4. The method for manufacturing a thermoplastic composite bicycle frame according to claim 1, wherein: In the shell forming step, each shell forms a transition section between the adjacent straight section butt joint edges and the bent section butt joint edges; in the shell butt joint step, the transition sections of the two or more shells partially abut against each other and are partially dislocated.

5. The method for manufacturing a thermoplastic composite bicycle frame according to claim 4, wherein: The method further includes a reinforcing step: attaching a reinforcing material to at least one of the inner side and the outer side of the butted edges of the bent sections of the two butted shells, with the reinforcing material covering the transition section, and curing the reinforcing material in a mold hot pressing step.

6. The method for manufacturing a thermoplastic composite bicycle frame according to claim 4, wherein: In the shell forming step, the length of the transition section is between 10 and 100 mm.

7. The method for manufacturing a thermoplastic composite bicycle frame according to any one of claims 1 to 6, characterized in that: Before the mold hot-pressing step, an inner support member capable of supporting each of the shell members is disposed inside the frame member formed by the two or more shell members. After the mold hot-pressing step, the inner support member located inside the frame member is removed, and trimming is performed to produce the finished frame member.

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