Process for the production of a carbon fiber electric bicycle

Abstract

The application discloses a preparation process of a carbon fiber electric bicycle, which comprises the following steps: determining that the head tube end face hole of the head tube hole end part of the carbon fiber electric bicycle frame, the seat tube hole, and the rotating shaft end face hole of the rotating shaft hole end part close to the motor seat and used for connecting the damping device are directly formed by using support molds; determining the core shaft structure of the carbon fiber electric bicycle frame, and the hollow part is connected to the seat tube hole on the core shaft structure; attaching carbon fiber gauze on the core shaft structure and the hollow part to form a preform with a required structure; the support mold comprises a first support mold, a second support mold and a third support mold; and the preform, the first support mold, the second support mold and the third support mold are placed in a forming mold to form a rough structure. By directly forming the head tube end face hole of the head tube hole end part, the seat tube hole and the rotating shaft end face hole of the rotating shaft hole end part by using the support molds, the processing time can be effectively saved, and the processing cost is saved.

Description

Technical Field

[0001] This invention belongs to the field of electric bicycles, and particularly relates to a manufacturing process for a carbon fiber electric bicycle. Background Technology

[0002] Carbon fiber electric bicycles have a much more complex design than traditional bicycles due to the need to assemble motors and implement shock absorption. This includes molding the motor mount in the bottom bracket area and setting up the shaft hole near the motor mount for connecting the shock absorption device. If a traditional spindle structure is used, the splicing and assembly would be too complicated, the pre-molding accuracy would be insufficient, resulting in a large error between the pre-molded body and the actual product, making it difficult to mold and greatly affecting product quality. In addition, carbon fiber electric bicycles have significantly more holes and assembly positions than traditional bicycles, resulting in longer machining time on the machine and hindering actual production. Summary of the Invention

[0003] The purpose of this invention is to provide a manufacturing process for carbon fiber electric bicycles that can effectively balance the allocation of mold and machining processes, effectively save processing time and reduce processing costs.

[0004] To achieve the above objectives, the present invention provides a manufacturing process for a carbon fiber electric bicycle, comprising the following steps: determining that the head tube end hole, seat tube hole, and pivot end hole near the motor mount and used for connecting the shock absorption device on the carbon fiber electric bicycle frame are directly formed using a support mold; determining the mandrel structure of the carbon fiber electric bicycle frame, wherein the mandrel structure has a head tube end face yarn-attached portion corresponding to the head tube end hole, a hollow component is connected to the seat tube hole on the mandrel structure, and a pivot end face yarn-attached portion is provided on the mandrel structure corresponding to the pivot end hole; attaching carbon fiber yarn to the mandrel structure and the hollow component to form a preform of the desired structure, and such that the carbon fiber is attached to the head tube end face yarn-attached portion. A pre-shaped hole is formed at the end of the head tube after the gauze is applied. A pre-shaped hole is formed at the end of the seat tube after the carbon fiber gauze is attached to the hollow part. A pre-shaped hole is formed at the end of the rotating shaft after the carbon fiber gauze is attached to the end face of the rotating shaft. The support module includes a first support module, a second support module, and a third support module. The first support module is set and embedded in the pre-shaped hole at the end of the head tube, the second support module is set and embedded in the pre-shaped hole at the end of the seat tube, and the third support module is set and embedded in the pre-shaped hole at the end of the rotating shaft. The pre-shaped body, the first support module, the second support module, and the third support module are placed in a molding mold to form a rough blank structure.

[0005] Preferably, the head tube end face holes correspond to the two ends of the head tube and respectively include a first head tube end face hole and a second head tube end face hole. The head tube end face yarn attaching portion includes a first head tube end face yarn attaching portion corresponding to the first head tube end face hole and a second head tube end face yarn attaching portion corresponding to the second head tube end face hole. The first head tube end face yarn attaching portion includes a first recessed portion recessed towards the inside of the mandrel structure, and the second head tube end face yarn attaching portion includes a second recessed portion recessed towards the inside of the mandrel structure. A first carbon ring is provided on the first recessed portion, and a second carbon ring is provided on the second recessed portion. The head tube end pre-shaped hole includes a first head tube end pre-shaped hole formed after attaching carbon fiber yarn to the first recessed portion and the first carbon ring, and a second head tube end pre-shaped hole formed by attaching carbon fiber yarn to the second recessed portion and the second carbon ring. The first support module includes a first head tube support module embedded in the first head tube end pre-shaped hole and a second head tube support module embedded in the second head tube end pre-shaped hole.

[0006] Preferably, the two ends of the rotating shaft end face corresponding to the rotating shaft hole respectively include a first rotating shaft end face face and a second rotating shaft end face face, the rotating shaft end face gauze applicator includes a first rotating shaft end face gauze applicator corresponding to the first rotating shaft end face face and a second rotating shaft end face gauze applicator corresponding to the second rotating shaft end face face, the rotating shaft end pre-shaped hole includes a first rotating shaft end pre-shaped hole formed after attaching carbon fiber gauze to the first rotating shaft end face gauze applicator and a second rotating shaft end pre-shaped hole formed after attaching carbon fiber gauze to the second rotating shaft end face gauze applicator, and the third support module includes a first rotating shaft support module embedded in the first rotating shaft end pre-shaped hole and a second rotating shaft support module embedded in the second rotating shaft end pre-shaped hole.

[0007] Preferably, the second support module includes a fifth end and a fifth rod connected to the fifth end. The fifth free end of the fifth rod is provided with a snap-fit ​​hole, and the mandrel structure is provided with an alignment protrusion corresponding to the snap-fit ​​hole. The mandrel structure and the fifth rod are mated together through the snap-fit ​​hole and the alignment protrusion.

[0008] Preferably, the step of determining that the head tube end hole, seat tube hole, and pivot end hole near the motor mount and used for connecting the shock absorption device on the carbon fiber electric bicycle frame are directly formed using a support mold further includes: determining that the motor mount on the carbon fiber electric bicycle frame is directly formed using a support mold; and the step of determining the spindle structure of the carbon fiber electric bicycle frame further includes: determining that the spindle structure includes a first spindle and a second spindle, the first spindle including a seat tube spindle, a lower tube spindle, an upper tube spindle, and a head tube spindle, the end of the seat tube spindle being connected to the end of the lower tube spindle to form a connecting end; one side of the second spindle The structure of the motor base is provided with a first opening, and the other side of the second mandrel is provided with a clearance space, which is provided with respect to the connecting end and the connecting end is embedded in the clearance space; and the step of attaching carbon fiber gauze to the mandrel structure and the hollow part to form a preform of the desired structure further includes: attaching carbon fiber gauze to the second mandrel to form a motor base preform; and the step of the support module including a first support module, a second support module and a third support module further includes: the support module further includes a fourth support module, which is embedded in the first opening to support the second mandrel and form the motor base.

[0009] Preferably, the side of the second mandrel connected to the first mandrel is provided with a clearance portion covering the connecting end, the clearance portion having the clearance space formed therein, the clearance portion having a clearance end face, the clearance end face being C-shaped, the clearance end face including a first arc-shaped transition surface, an intermediate connecting surface and a second arc-shaped transition surface connected in sequence, the first arc-shaped transition surface, the intermediate connecting surface and the second arc-shaped transition surface extending downward from the seat tube mandrel, the first arc-shaped transition surface and the second arc-shaped transition surface being convex outward.

[0010] Preferably, the second mandrel has a mandrel hole corresponding to the mounting hole of the motor seat, the carbon fiber yarn layer includes a first yarn layer filled in the mandrel hole and a second yarn layer covering the first mandrel and the second mandrel, the fourth support module includes a first part embedded in the first opening and a second part located outside the first opening, and the bottom of the first yarn layer abuts against the first part of the fourth support module.

[0011] Preferably, the second spindle is further provided with the first spindle yarn attaching part and the second spindle yarn attaching part. The first spindle yarn attaching part includes a third recessed part that is recessed into the second spindle, and the second spindle yarn attaching part includes a fourth recessed part that is recessed into the second spindle. A third carbon ring is provided on the third recessed part, and a fourth carbon ring is provided on the fourth recessed part. In step S3, the step of forming a pre-shaped hole on the spindle end face after attaching carbon fiber yarn to the yarn attaching part includes: S31, attaching carbon fiber yarn to the third recessed part and the third carbon ring to form a first spindle end pre-shaped hole; S32, attaching carbon fiber yarn to the fourth recessed part and the fourth carbon ring to form a second spindle end pre-shaped hole.

[0012] Preferably, after the step of placing the preform and the first support module, the second support module and the third support module in the forming mold, the process further includes: mounting the rough blank structure on a fixture for machining to complete the preparation of the vehicle frame. The fixture is provided with a first positioning element, a second positioning element and a third positioning element corresponding to the head tube end hole, seat tube hole and shaft end hole on the rough blank structure, respectively. The first positioning element, the second positioning element and the third positioning element are used to define the position of the rough blank structure.

[0013] Preferably, the head tube end face holes correspond to the two ends of the head tube and respectively include a first head tube end face hole and a second head tube end face hole, the pivot end face holes correspond to the two ends of the pivot hole and respectively include a first pivot end face hole and a second pivot end face hole, the first positioning member is provided with a first positioning protrusion, the first positioning protrusion is embedded in the first head tube end face hole or the second head tube end face hole, the second positioning member includes a positioning rod, the positioning rod is embedded in the seat tube hole, and the third positioning member includes a protrusion corresponding to the first pivot end face hole or the second pivot end face hole, the protrusion is embedded in the first pivot end face hole or the second pivot end face hole.

[0014] Compared with the prior art, the present invention directly forms the head tube end hole, seat tube hole, and shaft end hole near the motor mount and used to connect the shock absorption device on the carbon fiber electric bicycle using a support mold. This can effectively balance the process allocation of mold and machine tool processing, effectively save processing time and processing costs. Attached Figure Description

[0015] Figure 1 This is a structural diagram of a carbon fiber electric bicycle frame according to an embodiment of the present invention.

[0016] Figure 2 This is a structural diagram of the carbon fiber electric bicycle frame from another angle, according to an embodiment of the present invention.

[0017] Figure 3 This is a structural diagram of the carbon fiber electric bicycle frame from another angle, according to an embodiment of the present invention.

[0018] Figure 4 for Figure 3 Enlarged view of point E in the middle.

[0019] Figure 5 This is a structural diagram of the first mandrel at one angle according to an embodiment of the present invention.

[0020] Figure 6 This is a structural diagram of the first mandrel from another angle according to an embodiment of the present invention.

[0021] Figure 7 This is a partial structural diagram of the mandrel structure according to an embodiment of the present invention. Only the mandrel structure at the motor mount is shown in the diagram.

[0022] Figure 8 This is a structural diagram of the second mandrel in an embodiment of the present invention.

[0023] Figure 9 This is a structural diagram of the second mandrel from another angle in an embodiment of the present invention.

[0024] Figure 10 This is a structural diagram of the preform of a carbon fiber electric bicycle frame according to an embodiment of the present invention.

[0025] Figure 11 This is a structural diagram of the preform of the carbon fiber electric bicycle frame according to an embodiment of the present invention from another angle.

[0026] Figure 12 This is a structural diagram of the carbon fiber electric bicycle frame according to an embodiment of the present invention, after the preform is connected to the first support module, the second support module, the third support module and the fourth support module.

[0027] Figure 13 This is a structural diagram from another angle showing the preform of the carbon fiber electric bicycle frame according to an embodiment of the present invention, after connecting the first support module, the second support module, the third support module, and the fourth support module.

[0028] Figure 14 This is a structural diagram of the connection between the preform and the fourth support module of the carbon fiber electric bicycle frame according to an embodiment of the present invention.

[0029] Figure 15 for Figure 14 Cross-sectional view along the GG direction.

[0030] Figure 16 This is a structural diagram of the first head tube support module according to an embodiment of the present invention.

[0031] Figure 17 This is a structural diagram of the second head tube support module according to an embodiment of the present invention.

[0032] Figure 18 This is a structural diagram of the seat tube support module according to an embodiment of the present invention.

[0033] Figure 19 This is a structural diagram of the first rotating shaft support module according to an embodiment of the present invention.

[0034] Figure 20 This is a structural diagram of the second rotating shaft support module according to an embodiment of the present invention.

[0035] Figure 21 This is a structural diagram of the fourth support module in an embodiment of the present invention.

[0036] Figure 22 This is a structural diagram of the molding die according to an embodiment of the present invention.

[0037] Figure 23 This is a structural diagram of the molding die housing in an embodiment of the present invention, showing the installation of a preform, a first support mold, a second support mold, a third support mold, and a fourth support mold.

[0038] Figure 24 This is a structural diagram of the rough blank structure installed on the fixture according to an embodiment of the present invention.

[0039] Figure 25 This is a structural diagram of the fixture according to an embodiment of the present invention. Detailed Implementation

[0040] To illustrate the technical content, structural features, and effects of the present invention in detail, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0041] like Figures 1 to 25 As shown in the figure, an embodiment of the present invention provides a manufacturing process for a carbon fiber electric bicycle, comprising the following steps: S1. It is determined that the head tube end face, seat tube hole 21, and shaft end face near the motor mount 4 and used for connecting the shock absorption device at the end of the head tube hole 11 on the carbon fiber electric bicycle frame will be directly formed using a support mold; specifically, such as... Figures 1 to 4As shown, the carbon fiber electric bicycle includes a frame 100, which includes a seat tube 2, a motor mount 4 connected to the seat tube 2, a head tube 1, an upper tube 6 connecting the head tube 1 and the seat tube 2, a lower tube 5 connecting the head tube 1 and the motor mount 4, and a pivot part 3 near the motor mount 4 for connecting a shock absorption device. The holes on the frame 100 are manufactured in two ways: one is by directly forming them using a mold, which can be a forming mold or a support mold, but this increases the complexity of the mold and the difficulty of bonding and molding the carbon fiber fabric; the other is by machining them using a CNC machine tool, but the machined holes... The more positions there are, the longer the machine setup and subsequent processing time will be, and the more five-axis machines will be required. Therefore, it is necessary to balance the allocation of mold forming and machine machining processes. The head tube end hole, seat tube hole 21 and shaft end hole require high precision. If machine machining is used for forming, the machining difficulty and processing time will be long. Therefore, considering the complexity of mold design and the machining time, it is determined that the head tube end hole at the end of the head tube hole 11, the seat tube hole 21 and the shaft end hole at the end of the shaft hole 31 on the shaft part 3 of the carbon fiber electric bicycle will be formed directly by the support mold.

[0042] S2. Determine the spindle structure 7 of the frame. The spindle structure 7 has a head tube end face yarn-attaching part corresponding to the head tube end hole. A hollow part is connected to the spindle structure 7 corresponding to the seat tube hole 21. The spindle structure 7 has a shaft end face yarn-attaching part corresponding to the shaft end hole. Specifically, such as... Figures 5 to 8 As shown, except for the holes and parts directly formed by molds, the remaining parts are formed by air pressure molding, and the remaining holes are machined by a machine. For the manufacturing scheme of this carbon fiber electric bicycle, the mandrel structure 7 of the frame 100 is designed and determined. The mandrel structure 7 is mainly a core material formed by removing the yarn layer thickness and reducing it inwards according to the product shape. It is an auxiliary material used to bond the carbon fiber yarn, playing a supporting and positioning role in the shape. Specifically, as... Figures 5 to 6 As shown, the mandrel structure 7 includes a head tube mandrel 715, a seat tube mandrel 711, an upper tube mandrel 714, and a lower tube mandrel 712. The seat tube mandrel 711 has a mounting protrusion 7111 at a distance from the upper tube mandrel 714 at one end. A hollow piece is fitted onto the mounting protrusion 7111 to connect with the seat tube mandrel 711. The mandrel structure 7 has a head tube end face gauze applicator corresponding to the structure and size of the head tube end face hole. The gauze applicator on the head tube end face faces the mandrel structure. The inner recess of the mandrel structure 7 has a hollow part (not shown in the figure) connected to the mandrel structure 7 with the structure and size corresponding to the seat tube hole 21. The mandrel structure 7 has a rotating shaft end face gauze part with the structure and size corresponding to the rotating shaft end face hole. The hollow part is made of a material with a certain hardness and relatively light weight, such as a carbon ring with a long tubular structure, but it is not limited to this. The seat tube hole 21 is designed to be formed by a hollow part independent of the mandrel structure 7, which can simplify the mandrel structure 7 and make the mandrel structure 7 easier to manufacture. The design is very ingenious.

[0043] S3. Carbon fiber gauze is attached to the mandrel structure 7 and the hollow part to form a preform 10 of the desired structure, such that after the carbon fiber gauze is attached to the gauze-attached part of the head tube end face, a preformed hole is formed at the end of the head tube; after the carbon fiber gauze is attached to the hollow part, a preformed hole 103 is formed at the seat tube end face; and after the carbon fiber gauze is attached to the gauze-attached part of the rotating shaft end face, a preformed hole is formed at the end face of the rotating shaft. Specifically, as follows: Figures 10 to 11 As shown, a preform 10 of the frame 100 is formed by attaching carbon fiber gauze to a preset position on the spindle structure 7, a preform hole at the end of the head tube is formed after attaching carbon fiber gauze to the gauze-attached part on the head tube end face, a preform hole 103 at the seat tube is formed after attaching carbon fiber gauze to the surface of the hollow part, and a preform hole at the end of the pivot shaft is formed after attaching carbon fiber gauze to the gauze-attached part on the pivot shaft end face.

[0044] S4. The support module includes a first support module, a second support module 40, and a third support module. The first support module is configured and embedded in the pre-formed hole at the end of the head tube. The second support module 40 is configured and embedded in the pre-formed hole 103 at the end of the seat tube. The third support module is configured and embedded in the pre-formed hole at the end face of the rotating shaft. Specifically, as shown... Figures 11 to 12 As shown, the outer diameter and structure of the portion of the first support module embedded in the pre-formed hole at the end of the head tube are the same as the inner diameter and structure required to be formed in the pre-formed hole of the head tube. The outer diameter and structure of the portion of the second support module 40 embedded in the pre-formed hole 103 of the seat tube are the same as the inner diameter and structure of the seat tube hole 21. The outer diameter and structure of the portion of the third support module embedded in the pre-formed hole on the end face of the rotating shaft are the same as the inner diameter and structure of the hole on the end face of the rotating shaft. In some other embodiments, the inner diameter of the portion of the third support module embedded in the hole on the end face of the rotating shaft can also be slightly smaller than the size of the hole on the end face of the rotating shaft and then machined to the required size of the hole on the end face of the rotating shaft through subsequent machining. This design can also reduce the amount of machining and save time.

[0045] S5. The preform 10, the first support mold, the second support mold 40, and the third support mold are placed in the forming mold 80 to form a rough blank structure 1000. Specifically, as shown... Figures 22 to 23As shown, the molding mold 80 corresponds to the structural configuration of the carbon fiber electric bicycle frame 100. The molding mold 80 includes a seat 802 and a cover 801 provided on the seat 802. The molding mold 80 has a molding cavity for installing the preform 10 of the frame 100, the first support mold, the second support mold 40 and the third support mold. The first support mold, the second support mold 40 and the third support mold are all hard solid structures and do not deform at a high temperature of 200 degrees. They are preferably made of stainless steel. The molding mold 80 and the first support mold, the second support mold 40 and the third support mold respectively mold the preformed hole at the end of the head tube, the preformed hole 103 of the seat tube and the preformed hole at the end of the pivot. For the parts of the frame 100 that are not molded, conventional air pressure molding is used by introducing air into the hollow interior of the spindle structure 7.

[0046] In this embodiment of the invention, the head tube end hole at the end of the head tube hole 11, the seat tube hole 21, and the shaft end hole at the end of the shaft hole 31 near the motor seat 4 and used to connect the shock absorption device are directly formed using a support mold. This can effectively balance the process allocation of the mold and the machining process, effectively save processing time and processing costs.

[0047] In embodiments of the present invention, such as Figure 1 , Figure 2 , Figure 5 and Figure 6 As shown, the head tube end face holes corresponding to both ends of the head tube 1 include a first head tube end face hole 12 and a second head tube end face hole 13, respectively. The head tube end face yarn-attaching part includes a first head tube end face yarn-attaching part corresponding to the first head tube end face hole 12 and a second head tube end face yarn-attaching part corresponding to the second head tube end face hole 13. The first head tube end face yarn-attaching part includes a first recessed part 7151 recessed into the mandrel structure 7, and the second head tube end face yarn-attaching part includes a second recessed part 7152 recessed into the mandrel structure 7. A first carbon ring is provided on the first recessed part 7151, and a second carbon ring is provided on the second recessed part 7152, as shown. Figures 10 to 11As shown, the pre-shaped hole at the end of the head tube includes a first pre-shaped hole 101 formed after attaching carbon fiber gauze to the first recess 7151 and the first carbon ring, and a second pre-shaped hole 102 formed by attaching carbon fiber gauze to the second recess 7152 and the second carbon ring. Specifically, the bottom of the first recess 7151 is circular, and the outer diameter of the first carbon ring is the same as the outer diameter of the bottom of the first recess 7151 for positioning and installing the first carbon ring. Carbon fiber gauze is attached to the first recess 7151 and the first carbon ring, and the first carbon ring is embedded in the carbon fiber gauze. The first carbon ring is used to increase the hardness of the hole 12 at the end of the first head tube. The bottom of the second recess 7152 is circular, and the outer diameter of the second carbon ring is the same as the outer diameter of the bottom of the second recess 7152 for positioning and installing the second carbon ring. Carbon fiber gauze is attached to the second recess 7152 and the second carbon ring, and the second carbon ring is embedded in the carbon fiber gauze. The second carbon ring is used to increase the hardness of the hole 13 at the end of the second head tube. Figures 12 to 13 As shown, the first support module includes a first head tube support module 20 embedded in the pre-formed hole 101 at the end of the first head tube and a second head tube support module 30 embedded in the pre-formed hole 102 at the end of the second head tube. Figure 16 As shown, the first head tube support module 20 includes a first end portion 201 and a first rod portion 202 connected to the first end portion 201. The first free end 203 of the first rod portion 202 is embedded in the pre-formed hole 101 at the end of the first head tube to form the end face 12 of the first head tube. The first rod portion 202 is also provided with a first limiting step portion 204 to limit the distance of the first rod portion 202 embedded in the pre-formed hole 101 at the end of the first head tube. The outer diameter and structure of the portion of the first rod portion 202 embedded in the pre-formed hole 101 at the end of the first head tube are the same as the inner diameter and structure of the end face 12 of the first head tube. Figure 17As shown, the second head tube support module 30 includes a second end 301 and a second rod portion 302 connected to the second end 301. The second rod portion 302 is also provided with a second limiting step portion 304 to limit the distance of the second rod portion 302 embedded in the pre-formed hole 102 at the end of the second head tube. The outer diameter and structure of the portion of the second rod portion 302 embedded in the pre-formed hole 102 at the end of the second head tube are the same as the inner diameter and structure of the hole 13 at the end of the second head tube. The second free end 303 of the second rod portion 302 is embedded in the pre-formed hole 102 at the end of the second head tube to form the hole 13 at the end of the second head tube. Specifically, the head tube 1 includes a head tube body and a first head tube end face 12 and a second head tube end face 13 connected to both ends of the head tube body, respectively. The head tube body 1 can be directly formed by a mandrel structure 7 and air pressure. The first head tube end face 12 and the second head tube end face 13 need to be fitted with bearings. Therefore, the first head tube end face 12 and the second head tube end face 13 require higher machining precision. Thus, the first head tube end face 12 and the second head tube end face 13 can be molded to save machining time. Of course, in some other embodiments, only one end of the head tube 1 can be directly formed by a support mold. This method can also partially balance the complexity of mold design and machine processing time.

[0048] In embodiments of the present invention, such as Figures 1 to 2 As shown, the two ends of the rotating shaft end face corresponding to the rotating shaft hole 31 respectively include a first rotating shaft end face face 32 and a second rotating shaft end face face 33. The rotating shaft end face yarn-applying part includes a first rotating shaft end face yarn-applying part corresponding to the first rotating shaft end face face 32 and a second rotating shaft end face yarn-applying part corresponding to the second rotating shaft end face face 33, as shown. Figures 10 to 11 As shown, the pre-shaped holes at the ends of the shaft include a first pre-shaped hole 104 formed after attaching carbon fiber yarn to the yarn-attaching portion of the first shaft end face, and a second pre-shaped hole 105 formed after attaching carbon fiber yarn to the yarn-attaching portion of the second shaft end face, as shown. Figures 12 to 13 As shown, the third support module includes a first shaft support module 50 embedded in the pre-formed hole 104 at the end of the first shaft and a second shaft support module 60 embedded in the pre-formed hole 105 at the end of the second shaft. Specifically, as... Figure 19 As shown, the first rotating shaft support module 50 includes a third end portion 501 and a third rod portion 502 connected to the third end portion 501. The outer diameter and structure of the third rod portion 502 are the same as or slightly smaller than the inner diameter and structure of the first rotating shaft end face hole 32 for subsequent machining. The third rod portion 502 is embedded in the pre-formed hole 104 at the end of the first rotating shaft to form the first rotating shaft end face hole 32; as Figure 20As shown, the second pivot support module 60 includes a fourth end 601 and a fourth rod 602 connected to the fourth end 601. The outer diameter and structure of the fourth rod 602 are the same as or slightly smaller than the inner diameter and structure of the second pivot end face 33 for subsequent machining. The fourth rod 602 is embedded in the pre-formed hole 105 at the end of the second pivot to form the second pivot end face 33.

[0049] In embodiments of the present invention, such as Figure 18 As shown, the second support module 40 includes a fifth end 401 and a fifth rod 402 connected to the fifth end 401. The fifth free end 403 of the fifth rod 402 is provided with a snap-fit ​​hole 404. The mandrel structure 7 is provided with an alignment protrusion corresponding to the snap-fit ​​hole 404. The mandrel structure 7 and the fifth rod 402 are engaged and connected through the snap-fit ​​hole 404 and the alignment protrusion.

[0050] In this embodiment of the invention, step S1, which involves directly forming the head tube end hole at the end of the head tube hole 11, the seat tube hole 21, and the shaft end hole at the end of the shaft hole 31 near the motor mount 4 and used to connect the shock absorption device, using a support mold, further includes: S10. It is determined that the outer shape of the motor mount 4 on the carbon fiber electric bicycle and the mounting surface 42 on the inner side of the motor mount 4 will be directly formed using a support mold; specifically, such as... Figures 1 to 4 As shown, the motor base 4 is formed in the bottom bracket area. The external structure of the motor base 4 is complex, and it is easier to implement by using a mold. The internal assembly plane 42 for mounting the motor also requires high precision. This assembly plane 42 is also directly formed using a support mold.

[0051] Furthermore, step S2, determining the spindle structure of the carbon fiber electric bicycle frame, also includes: S20. The mandrel structure 7 is defined as including a first mandrel 71 and a second mandrel 72. The first mandrel 71 includes a seat tube mandrel 711, a lower tube mandrel 712, an upper tube mandrel 714, and a head tube mandrel 715. The end of the seat tube mandrel 711 is connected to the end of the lower tube mandrel 712 to form a connecting end 713. One side of the second mandrel 72 is provided with a first opening 721 corresponding to the structure of the motor seat 4, and the other side of the second mandrel 72 is provided with a clearance space 724. The clearance space 724 is provided with the connecting end 713 and the connecting end 713 is embedded in the clearance space 724. Specifically, as shown in the figure... Figures 5 to 9As shown, a hollow component (not shown in the figure) is also connected to the seat tube mandrel 711. The lower tube mandrel 712 is also used to form the lower tube 5. The first mandrel 71 has an internal hollow structure for introducing high-pressure gas into the first mandrel 71, causing the first mandrel 71 to expand so that the carbon fiber gauze on the first mandrel 71 is formed by air pressure. The structure of the second mandrel 72 is the same as the shape of the motor seat 4. The first opening 721 corresponds to the motor mounting port 41 of the motor seat 4.

[0052] Furthermore, step S3, which involves attaching carbon fiber gauze to the mandrel structure 7 and the hollow component to form the preform 10 of the desired structure, also includes: S30, such as Figures 10 to 11 As shown, carbon fiber gauze is attached to the second mandrel 72 to form the motor mount preform 106.

[0053] Furthermore, in step S4, the support module includes a first support module, a second support module 40, and a third support module. The step further includes: S40, the support module also includes a fourth support module 70, which is embedded in the first opening 721 to support the second spindle 72 and form the motor seat 4. Specifically, as shown... Figures 12 to 15 As shown, the fourth support module 70 is a rigid solid structure that does not deform at a high temperature of 200 degrees Celsius, and is preferably made of stainless steel.

[0054] And, in step S5, the preform 10, the first support mold, the second support mold 40, and the third support mold are placed in the molding mold 80 to form a rough blank structure 1000, including: S50, the first mandrel 71, the second mandrel 72, the preform 10 disposed on the first mandrel 71 and the second mandrel 72, and the first support mold, the second support mold 40, the third support mold, and the fourth support mold 70 are placed in the forming mold 80 to form a rough blank structure 1000. Specifically, as follows: Figures 22 to 23 As shown, a clearance opening 803 is provided inside the molding die 80 corresponding to the fourth support module 70. The fourth support module 70 is installed at the clearance opening 803. The carbon fiber yarn on the second mandrel 72 is sandwiched between the inner surfaces of the fourth support module 70 and the molding die 80, and the carbon fiber yarn on the second mandrel 72 is cured by compression molding. By using a combined mandrel structure composed of the second mandrel 72 and the first mandrel 71 to form the structure of the motor seat 4, and using the fourth support module 70 to support it in the first opening 721 of the second mandrel 72, the problem of large dimensional changes of the carbon fiber yarn layer 8 on the second mandrel 72 during the compression molding process is prevented, so as to ensure the span accuracy requirements of the motor seat 4. The molding process of the motor seat 4 is simple, the yield is high, and the design is very ingenious.

[0055] In embodiments of the present invention, such as Figures 5 to 9As shown, the second mandrel 72 has a clearance portion covering the connecting end 713 on the side where it connects to the first mandrel 71. A clearance space 724 is formed within the clearance portion. The clearance portion has a clearance end face 722, which is C-shaped. The clearance end face 722 includes a first arc-shaped transition surface 7221, an intermediate connecting surface 7222, and a second arc-shaped transition surface 7223 connected sequentially. The first arc-shaped transition surface 7221, the intermediate connecting surface 7222, and the second arc-shaped transition surface 7223 extend from the seat mandrel 711 to the lower mandrel 712. The first arc-shaped transition surface 7221 and the second arc-shaped transition surface 7223 are convex. Specifically, as shown... Figures 14 to 15 As shown, due to the different pressures of molding and air pressure, the inner wall of the carbon fiber yarn layer 8 in the interface area between air pressure and molding will be uneven and have steps. In this embodiment, the first arc-shaped transition surface 7221 and the second arc-shaped transition surface 7223 are convex. The air pressure force on the first arc-shaped transition surface 7221 and the second arc-shaped transition surface 7223 during the molding process is set perpendicular to the relief end face 722, as shown by arrows A and B. The force of arrows A and B can offset part of the force generated by molding, as shown by arrows C and D, so that the air pressure part can smoothly transition to the molding part, making the inner wall of the product as smooth as possible.

[0056] In embodiments of the present invention, such as Figure 7 , Figure 14 and Figure 21 As shown, the second spindle 72 has a spindle hole 7211 corresponding to the mounting hole 43 of the motor seat 4. The spindle hole 7211 is filled with carbon fiber gauze to form a first yarn layer 81. Carbon fiber gauze is attached to the first spindle 71, the second spindle 72, and the hollow component to form the second yarn layer 82. The fourth support module 70 includes a first part 701 embedded in the first opening 721 and a second part 702 located outside the first opening 721. The first part 701 corresponds to the internal structure and dimensions of the motor seat 4. The bottom of the first yarn layer 81 presses against the first part 701 of the fourth support module 70. Specifically, as shown... Figures 4 to 14 As shown, a first yarn layer 81 is filled into the spindle hole 7211 to form the connecting hole of the motor seat 4. The inner end face of the connecting hole is the mounting plane 42 of the motor seat 4. The connecting hole can be machined to form the mounting hole 43 of the motor seat 4. The bottom of the first yarn layer 81 presses against the upper surface of the first part 701 of the fourth support module 70. The upper surface of the first part 701 is flat. Therefore, the inner end face of the formed connecting hole is very flat, and no further machining is required. The process is simple and cost-saving. At the same time, since the fourth support module 70 is supported on the second spindle 72 and the fourth support module 70 does not deform, the distance H between the inner end faces of the two opposite connecting holes is limited, ensuring the manufacturing accuracy of the motor seat 4.

[0057] In embodiments of the present invention, such as Figure 21 As shown, the connection between the second part 702 and the first part 701 is higher than the outer surface of the first part 701 to form a limiting step 703. Specifically, the limiting step 20 is cleverly designed to ensure that the fourth support module 70 is installed in place within the first opening 721.

[0058] In this embodiment of the invention, the interior of the seat tube mandrel 711 has a first through hole along its length, the interior of the lower tube mandrel 712 has a second through hole along its length, and the interior of the connecting end 713 has a third through hole. The first, second, and third through holes are interconnected. Specifically, the interior of the head tube mandrel 715 has a fourth through hole, and the interior of the upper tube mandrel 714 has a fifth through hole. The first, second, third, fourth, and fifth through holes are interconnected. High-pressure gas is introduced into the first, second, third, fourth, and fifth through holes to perform wind-pressure molding on the carbon fiber gauze attached to the first mandrel 71.

[0059] In embodiments of the present invention, such as Figure 5 As shown, the connecting end 713 is provided with a protrusion 7131, and the second spindle 72 is provided with a recessed hole that mates with the protrusion 7131 so that the first spindle 71 and the second spindle 72 are aligned and fitted. The protrusion 7131 and the recessed hole are aligned and fitted to better align and install the first spindle 71 and the second spindle 72.

[0060] In this embodiment of the invention, a scribe line or a stepped structure 723 is provided on one side edge of the second mandrel 72 for aligning the second yarn layer 82. Specifically, the distance between the scribe line or the stepped portion and the edge of the second mandrel 72 is 10 mm. By providing the scribe line or the stepped portion, alignment can be easily achieved when attaching the carbon fiber yarn layer 8, reducing the situation of exceeding the yarn attachment area, reducing the amount of subsequent machining, and effectively saving time and cost.

[0061] In this embodiment of the invention, the first mandrel 71 is a polypropylene mandrel or a latex mandrel, and the second mandrel 72 is a polyurethane mandrel. Specifically, the first mandrel 71 is a PP mandrel or a latex mandrel, and the second mandrel 72 is a PU mandrel.

[0062] In this embodiment of the invention, the second spindle 72 is further provided with a first spindle yarn-attaching part and a second spindle yarn-attaching part. The first spindle yarn-attaching part includes a third recessed part 725 recessed inward of the second spindle 72, and the second spindle yarn-attaching part includes a fourth recessed part 726 recessed inward of the second spindle 72. A third carbon ring is provided on the third recessed part 725, and a fourth carbon ring is provided on the fourth recessed part 726. In step S3, the step of forming a pre-shaped hole on the spindle end face after attaching carbon fiber yarn to the yarn-attaching part includes: S31. Carbon fiber gauze is attached to the third recess 725 and the third carbon ring to form a pre-shaped hole 105 at the end of the second shaft. Specifically, the bottom of the third recess 725 is round, and the outer diameter of the third carbon ring is the same as the bottom outer diameter of the third recess 725 to position and install the third carbon ring. Carbon fiber gauze is attached to the third recess 725 and the third carbon ring, and the third carbon ring is embedded in the carbon fiber gauze. The third carbon ring is used to increase the hardness of the hole 32 at the end of the first shaft.

[0063] S32. Carbon fiber gauze is attached to the fourth recess 726 and the fourth carbon ring to form a pre-formed hole 105 at the end of the second shaft. Specifically, the bottom of the fourth recess 726 is rounded, and the outer diameter of the fourth carbon ring is the same as the outer diameter of the bottom of the fourth recess 726 to position and install the fourth carbon ring. Carbon fiber gauze is attached to the fourth recess 726 and the fourth carbon ring, and the fourth carbon ring is embedded in the carbon fiber gauze. The fourth carbon ring is used to increase the hardness of the hole 33 at the end of the second shaft.

[0064] In this embodiment of the invention, after the step of placing the preform 10 and the first support mold, the second support mold 40, and the third support mold in the forming mold 80 in step S5, the method further includes: S6. The rough blank structure 1000 is mounted on the fixture 9 and machined to complete the preparation of the carbon fiber electric bicycle frame 10. The fixture 9 is provided with a first positioning member 92, a second positioning member 93 and a third positioning member 94 corresponding to the head tube end hole, seat tube hole 21 and shaft end hole on the rough blank structure 1000. The first positioning member 92, the second positioning member 93 and the third positioning member 94 are used to limit the position of the rough blank structure 1000.

[0065] Specifically, the first positioning member 92 is provided with a first positioning protrusion 922, which is embedded in the first head tube end hole 12 or the second head tube end hole 13. The second positioning member 93 includes a positioning rod 933, which is embedded in the seat tube hole 21. The third positioning member 94 includes a protrusion 94 corresponding to the first rotating shaft end hole 32 or the second rotating shaft end hole 33, which is embedded in the first rotating shaft end hole 32 or the second rotating shaft end hole 33. In this embodiment of the invention, the selection of head tube end holes, seat tube holes 21, and shaft end holes for direct molding using a mold is also to solve the machining positioning problem of the formed rough blank structure 1000. The head tube end holes, seat tube holes 21, and shaft end holes are dispersed and can roughly form a stable triangular distribution. First, the head tube end holes, seat tube holes 21, and shaft end holes are formed using a support mold and a forming mold 80. Then, the head tube end holes, seat tube holes 21, and shaft end holes are used for positioning, ensuring that the installation position of products of the same model on the fixture 9 is consistent. This avoids the problem of inconsistent clamping positions of each frame 100 rough blank structure 1000 on the fixture 9 due to inaccurate clamping positions, resulting in low machining stability and improving the stability and accuracy of machine tool processing. Figures 24 to 25As shown, the fixture 9 includes a base plate 91 and a first positioning member 92, a second positioning member 93, and a third positioning member 94 disposed on the base plate 91. The first positioning member 92 includes a first positioning seat 921 vertically disposed on the base plate 91. The first positioning seat 921 is provided with a first positioning protrusion 922 corresponding to the first head tube end hole 12 or the second head tube end hole 13. The first positioning protrusion 922 is used to be embedded in the first head tube end hole 12 or the second head tube end hole 13. The second positioning member 94 includes... The system includes a second lower positioning seat 931 mounted on the base plate 91, a second upper positioning seat 932 connected to the second lower positioning seat 931, and a positioning rod 933 sandwiched between the second lower positioning seat 931 and the second upper positioning seat 932. The positioning rod 933 is used to be embedded in the seat tube hole 21. The third positioning member 94 is a protrusion 94 corresponding to the first rotating shaft end face 32 or the second rotating shaft end face 33. The third positioning member 94 is embedded in the first rotating shaft end face 32 or the second rotating shaft end face 33. The base plate 91 is also provided with a first clamp 95, a second clamp 96, and a third clamp 97. The first clamp 95, the second clamp 96, and the third clamp 97 are respectively used to clamp the connection between the upper tube 6 and the lower tube 5 of the rough blank structure 1000, the connection between the upper tube 6 and the seat tube 2, and the connection between the seat tube 2 and the lower tube 5. The first clamp 95 includes a first lower seat body 951 detachably connected to the first lower seat body 951 and a first upper seat body 952 that cooperates with the first lower seat body 951. The first lower seat body 951 is provided on the base plate 91. A first clamping hole 953 and a second clamping hole 954 are formed between the first upper seat body 952 and the first lower seat body 951. The upper tube 6 and the lower tube 5 are respectively passed through and clamped in the first clamping hole 953 and the second clamping hole 954. The second clamp 96 includes a second lower seat body 961 detachably connected to the second lower seat body 961 and a second upper seat body 962 that cooperates with the second lower seat body 961. The second lower seat body 961 is provided with On the base plate 91, a third clamping hole 963 and a fourth clamping hole 964 are formed between the second upper seat body 962 and the second lower seat body 961. The seat tube 2 and the upper tube 6 are respectively inserted and clamped in the third clamping hole 963 and the fourth clamping hole 964. The third clamp 97 includes a third lower seat body 971 that is detachably connected to the third lower seat body 971 and a third upper seat body 972 that cooperates with the third lower seat body 971. The third lower seat body 971 is located on the base plate 91. A fifth clamping hole 973 and a sixth clamping hole 974 are formed between the third upper seat body 972 and the third lower seat body 971. The seat tube 2 and the lower tube 5 are respectively inserted and clamped in the fifth clamping hole 973 and the sixth clamping hole 974. The third lower seat body 971 is also provided with a protrusion 94 corresponding to the first rotating shaft end face 32 or the second rotating shaft end face 33. The protrusion 94 is directly provided on the third lower seat body 971, which simplifies the design process and is a very ingenious design. In this embodiment of the invention, the first positioning member 92 is located at the end away from the second positioning member 93, so as to make the positioning more stable.This invention employs a positioning rod 933 installed in the seat tube hole 21 for positioning, and a second end tube hole 13 installed on the first positioning protrusion 922. Simultaneously, a first rotating shaft end hole 32 is installed on the protrusion 94. This ensures that products of the same model are consistently positioned on the fixture 9, avoiding the problem of inconsistent clamping positions leading to low machining stability for each frame 100 rough blank structure 1000 on the fixture 9. In contrast, existing frame rough blank structures, which are entirely air-pressurized and closed, lack any holes and are only positioned by clamps. This inconsistency in clamping positions results in inconsistent clamping positions for each frame 100 rough blank structure 1000 on the fixture 9, affecting the machining accuracy.

[0066] The above-disclosed examples are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention shall still fall within the scope of the present invention.

Claims

1. A manufacturing process for a carbon fiber electric bicycle, characterized in that, Includes the following steps: It is determined that the head tube end hole, seat tube hole, and shaft end hole near the motor mount and used to connect the shock absorption device on the carbon fiber electric bicycle frame will be directly formed using a support mold. The spindle structure of the carbon fiber electric bicycle frame is determined. The spindle structure has a head tube end face yarn-attaching part corresponding to the head tube end face hole. A hollow part is connected to the seat tube hole on the spindle structure. A spindle end face yarn-attaching part is provided on the spindle structure corresponding to the shaft end face hole. Carbon fiber gauze is attached to the mandrel structure and the hollow part to form a preform of the desired structure, and carbon fiber gauze is attached to the end face of the head tube to form a preformed hole at the end of the head tube, carbon fiber gauze is attached to the hollow part to form a preformed hole at the seat tube, and carbon fiber gauze is attached to the end face of the rotating shaft to form a preformed hole at the end face of the rotating shaft. The support module includes a first support module, a second support module, and a third support module. The first support module is configured and embedded in the pre-formed hole at the end of the head tube. The second support module is configured and embedded in the pre-formed hole at the end of the seat tube. The third support module is configured and embedded in the pre-formed hole at the end face of the rotating shaft. The preform, the first support module, the second support module, and the third support module are placed in a molding die to form a rough blank structure; The step of directly forming the head tube end hole, seat tube hole, and pivot end hole near the motor mount and used for connecting the shock absorption device on the carbon fiber electric bicycle frame using a support mold further includes: It was determined that the motor mount on the carbon fiber electric bicycle frame would be directly molded using a support module; and, The step of determining the spindle structure of the carbon fiber electric bicycle frame further includes: The mandrel structure is defined as including a first mandrel and a second mandrel. The first mandrel includes a seat tube mandrel, a lower tube mandrel, an upper tube mandrel, and a head tube mandrel. The ends of the seat tube mandrel and the lower tube mandrel are connected to each other to form a connecting end. One side of the second mandrel corresponds to the structure of the motor seat and has a first opening. The other side of the second mandrel has a clearance space, which corresponds to the connecting end and is embedded in the clearance space. The side of the second mandrel connected to the first mandrel has a clearance portion covering the connecting end, and the clearance portion forms the clearance space. The clearance portion has a clearance end face, which is C-shaped and includes a first arc-shaped transition surface, an intermediate connecting surface, and a second arc-shaped transition surface connected in sequence. The first arc-shaped transition surface, the intermediate connecting surface, and the second arc-shaped transition surface extend from the seat tube mandrel to the lower tube mandrel. The first arc-shaped transition surface and the second arc-shaped transition surface are convex. The step of attaching carbon fiber gauze to the mandrel structure and the hollow component to form a preform of the desired structure further includes: Carbon fiber gauze is attached to the second mandrel to form a motor housing preform; and... The supporting module includes a first supporting module, a second supporting module, and a third supporting module. The step further includes: The support module further includes a fourth support module, which is embedded in the first opening to support the second mandrel and form the motor seat.

2. The manufacturing process of the carbon fiber electric bicycle as described in claim 1, characterized in that, The head tube end face holes correspond to the two ends of the head tube and respectively include a first head tube end face hole and a second head tube end face hole. The head tube end face yarn attaching part includes a first head tube end face yarn attaching part corresponding to the first head tube end face hole and a second head tube end face yarn attaching part corresponding to the second head tube end face hole. The first head tube end face yarn attaching part includes a first recessed part that is recessed into the mandrel structure, and the second head tube end face yarn attaching part includes a second recessed part that is recessed into the mandrel structure. A first carbon ring is provided on the first recessed part, and a second carbon ring is provided on the second recessed part. The head tube end pre-shaped hole includes a first head tube end pre-shaped hole formed after attaching carbon fiber yarn to the first recessed part and the first carbon ring, and a second head tube end pre-shaped hole formed by attaching carbon fiber yarn to the second recessed part and the second carbon ring. The first support module includes a first head tube support module embedded in the first head tube end pre-shaped hole and a second head tube support module embedded in the second head tube end pre-shaped hole.

3. The manufacturing process of the carbon fiber electric bicycle as described in claim 2, characterized in that, The two ends of the rotating shaft end face corresponding to the rotating shaft hole respectively include a first rotating shaft end face face and a second rotating shaft end face face. The rotating shaft end face gauze attaching part includes a first rotating shaft end face gauze attaching part corresponding to the first rotating shaft end face face and a second rotating shaft end face gauze attaching part corresponding to the second rotating shaft end face face. The rotating shaft end pre-shaped hole includes a first rotating shaft end pre-shaped hole formed after attaching carbon fiber gauze to the first rotating shaft end face gauze attaching part and a second rotating shaft end pre-shaped hole formed after attaching carbon fiber gauze to the second rotating shaft end face gauze attaching part. The third support module includes a first rotating shaft support module embedded in the first rotating shaft end pre-shaped hole and a second rotating shaft support module embedded in the second rotating shaft end pre-shaped hole.

4. The manufacturing process of the carbon fiber electric bicycle as described in claim 1, characterized in that, The second support module includes a fifth end and a fifth rod connected to the fifth end. The fifth free end of the fifth rod is provided with a snap-fit ​​hole. The mandrel structure is provided with an alignment protrusion corresponding to the snap-fit ​​hole. The mandrel structure and the fifth rod are mated together through the snap-fit ​​hole and the alignment protrusion.

5. The manufacturing process of the carbon fiber electric bicycle as described in claim 1, characterized in that, The second mandrel has a mandrel hole corresponding to the mounting hole of the motor seat. The carbon fiber yarn layer includes a first yarn layer filled in the mandrel hole and a second yarn layer covering the first mandrel and the second mandrel. The fourth support module includes a first part embedded in the first opening and a second part located outside the first opening. The bottom of the first yarn layer presses against the first part of the fourth support module.

6. The manufacturing process of the carbon fiber electric bicycle as described in claim 1, characterized in that, The second mandrel is further provided with a first rotating shaft yarn-attaching part and a second rotating shaft yarn-attaching part. The first rotating shaft yarn-attaching part includes a third recessed part that is recessed inward toward the second mandrel, and the second rotating shaft yarn-attaching part includes a fourth recessed part that is recessed inward toward the second mandrel. A third carbon ring is provided on the third recessed part, and a fourth carbon ring is provided on the fourth recessed part. In step S3, the step of forming a pre-shaped hole on the rotating shaft end face after attaching carbon fiber yarn to the yarn-attaching part includes: S31. Attach carbon fiber gauze to the third recess and the third carbon ring to form a pre-shaped hole at the end of the first shaft. S32. Attach carbon fiber gauze to the fourth recess and the fourth carbon ring to form a pre-shaped hole at the end of the second shaft.

7. The manufacturing process of the carbon fiber electric bicycle as described in claim 1, characterized in that, After the step of placing the preform, the first support mold, the second support mold, and the third support mold into the molding die, the process further includes: The rough blank structure is mounted on a fixture for machining to complete the preparation of the vehicle frame. The fixture is provided with a first positioning member, a second positioning member, and a third positioning member corresponding to the head tube end hole, seat tube hole, and shaft end hole on the rough blank structure. The first positioning member, the second positioning member, and the third positioning member are used to define the position of the rough blank structure.

8. The manufacturing process of the carbon fiber electric bicycle as described in claim 7, characterized in that, The head tube end face corresponding to both ends of the head tube includes a first head tube end face and a second head tube end face, respectively. The pivot end face corresponding to both ends of the pivot hole includes a first pivot end face and a second pivot end face, respectively. The first positioning member is provided with a first positioning protrusion, which is embedded in the first head tube end face or the second head tube end face. The second positioning member includes a positioning rod, which is embedded in the seat tube hole. The third positioning member includes a protrusion corresponding to the first pivot end face or the second pivot end face, which is embedded in the first pivot end face or the second pivot end face.

Images