Method for manufacturing auxiliary mandrel and method for manufacturing carbon fiber product

Abstract

The application discloses a kind of auxiliary mandrel production methods, auxiliary mandrel is used for carbon fiber product, production method includes the following steps: production mandrel blank, mandrel blank corresponds the shape of carbon fiber product, size setting, and the size of mandrel blank has preset margin relative to the size of carbon fiber product;Non-stick film is attached to the outer surface of mandrel blank, non-stick film completely wraps mandrel blank;Glass fiber cloth is attached to the outer surface of non-stick film, glass fiber cloth completely wraps non-stick film;Fastener is wound with glass fiber cloth to press glass fiber cloth on mandrel blank;Mandrel blank with fastener is wound is baked to make glass fiber cloth shape;Remove fastener;Mandrel blank is taken out to form hollow auxiliary mandrel. Carbon fiber product is made using the auxiliary mandrel, and is not easy to deform after being placed for a long time or being extruded by external force due to the support of the auxiliary mandrel.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of carbon fiber forming, and particularly to a method for manufacturing an auxiliary mandrel and a method for manufacturing a carbon fiber product. BACKGROUND

[0002] As a new type of material, carbon fiber products made of carbon fiber are popular due to their light weight and high strength. Carbon fiber materials are commonly used in the manufacture of products such as bicycle frames and electric vehicle frames.

[0003] For the early pipe connection area of the bicycle frame, a silicone auxiliary mandrel is made to simulate the pipe connection area. Carbon fiber material is first attached to the silicone auxiliary mandrel to form a preform of the pipe connection area. After the attachment, the silicone mandrel is removed for reuse. The advantage of this method is that the silicone mandrel can be reused. However, the silicone mandrel is prone to deformation after being removed due to the softness of the carbon fiber material. In addition, the preform is prone to quality problems such as creases after curing. SUMMARY

[0004] The present application provides a method for manufacturing an auxiliary mandrel and a method for manufacturing a carbon fiber product, which avoids the problem of deformation of the carbon fiber product after being placed for a long time or being squeezed by external force, and the problem of creases in the preform after curing.

[0005] To achieve the above-mentioned purpose, in a first aspect, the present application provides a method for manufacturing an auxiliary mandrel for a carbon fiber product, comprising the following steps: manufacturing a mandrel blank, the mandrel blank corresponding to the shape and size of the carbon fiber product, and the size of the mandrel blank having a predetermined excess amount relative to the size of the carbon fiber product; attaching a non-stick film to the outer surface of the mandrel blank, the non-stick film completely wrapping the mandrel blank; attaching a glass fiber cloth to the outer surface of the non-stick film, the glass fiber cloth completely wrapping the non-stick film; winding the glass fiber cloth with a fastener to press the glass fiber cloth onto the mandrel blank; baking the mandrel blank with the fastener to set the glass fiber cloth; removing the fastener; and removing the mandrel blank to form a hollow auxiliary mandrel.

[0006] Preferably, the step of removing the mandrel blank to form a hollow auxiliary mandrel includes cutting the glass fiber cloth and the non-stick film along the outer contour of the cured glass fiber cloth to expose the mandrel blank; and removing the mandrel blank.

[0007] Preferably, the step of removing the mandrel blank is followed by the step of removing the non-stick film to form an auxiliary mandrel containing only the glass fiber cloth.

[0008] Preferably, the carbon fiber product is a carbon fiber front fork of a carbon fiber bicycle, the mandrel blank comprises a stem blank and left and right fork bone blanks extending to both sides along the stem blank, the preset allowance comprises a circumferential allowance, the length of the stem blank, the length of the left fork bone blank and the length of the right fork bone blank are all greater than or equal to the length of the corresponding part of the carbon fiber product; the circumferential size of the stem blank, the circumferential size of the left fork bone blank and the circumferential size of the right fork bone blank are all less than the circumferential size of the corresponding part of the carbon fiber product to form the circumferential allowance, the circumferential allowance of the stem blank in the circumferential direction, the circumferential allowance of the left fork bone blank in the circumferential direction and the circumferential allowance of the right fork bone blank in the circumferential direction are all greater than or equal to 1.5 mm and less than or equal to 3 mm.

[0009] Preferably, the baking temperature is 150°±5° and the baking time is 1 hour.

[0010] Preferably, the thickness of the glass fiber cloth is 0.5 mm.

[0011] Preferably, the non-stick film is a preservative film.

[0012] Preferably, the fastener is an OOP binding tape or a shrink film.

[0013] In the second aspect, the application further provides a method for manufacturing a carbon fiber product, comprising the following steps: providing a wind pipe; placing the wind pipe in a hollow auxiliary mandrel manufactured by the method for manufacturing an auxiliary mandrel of the first aspect; bonding a carbon fiber material on the auxiliary mandrel to form a preform of the carbon fiber product; placing the auxiliary mandrel and the preform in a mold, heating the mold and introducing a gas with a certain pressure into the wind pipe to make the preform solidify and form; and taking out the wind pipe to form the carbon fiber product integrated with the auxiliary mandrel and the solidified preform.

[0014] Preferably, the auxiliary mandrel has an opening formed by cutting along the outer contour to take out the mandrel blank, and the step of placing the wind pipe in the hollow auxiliary mandrel manufactured by the method for manufacturing an auxiliary mandrel of the first aspect comprises: placing the wind pipe in the hollow auxiliary mandrel from the opening; and bonding the opening with adhesive tape.

[0015] Compared with the prior art, the method for manufacturing an auxiliary mandrel of the application first manufactures a mandrel blank with a preset size and shape, and then successively bonds a non-stick film and a glass fiber cloth on the mandrel blank to finally form an auxiliary mandrel with a fixed shape. The carbon fiber product manufactured by using the auxiliary mandrel is not easy to deform after being placed for a long time or being extruded by external force due to the support of the auxiliary mandrel, and the preform of the carbon fiber product is also not easy to have quality problems such as creases after being solidified and formed. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The structure diagram of the mandrel blank of the embodiment of the present application.

[0017] Figure 2 The structure diagram of the mandrel blank of the embodiment of the present application.

[0018] Figure 3 The cutting trajectory diagram when the auxiliary mandrel is cut off to take out the mandrel blank in the embodiment of the present application.

[0019] Figure 4 The structure diagram of the auxiliary mandrel after the auxiliary mandrel is cut off to take out the mandrel blank in the embodiment of the present application.

[0020] Figure 5 The cutting trajectory diagram when the auxiliary mandrel is cut off to take out the mandrel blank in another specific embodiment of the present application.

[0021] Figure 6 The structure diagram of the auxiliary mandrel. DETAILED DESCRIPTION

[0022] To make the technical content, structural features and effects of the present application clear, the following will be described in detail in combination with the embodiments and the accompanying drawings.

[0023] As shown in Figures 1 to 6 The present application provides a manufacturing method of an auxiliary mandrel 100 for a carbon fiber product, which comprises the following steps:

[0024] S1, manufacturing a mandrel blank 10, the mandrel blank 10 is set according to the shape and size of the carbon fiber product, and the size of the mandrel blank 10 has a preset allowance relative to the size of the carbon fiber product; specifically, the mandrel blank 10 is an aluminum product, a steel product, or even a resin product, as long as it can withstand a high temperature of 150 degrees or above and can provide a certain supporting force, the shape of the mandrel blank 10 is set according to the shape and size of the carbon fiber product, for example, when the carbon fiber product is a carbon fiber front fork of a carbon fiber bicycle, the shape of the mandrel blank 10 is also the shape of the carbon fiber front fork, the mandrel blank 10 includes a vertical pipe blank 1 and left and right fork bone blanks 2 and 3 extending to both sides along the vertical pipe blank 1, as shown in Figure 1 only has a preset allowance in the length direction a and the circumferential direction b to perform subsequent process processing, and finally reaches the required size of the carbon fiber product.

[0025] S2, a non-stick film is attached to the outer surface of the mandrel blank 10, and the non-stick film completely wraps the mandrel blank 10; specifically, the non-stick film is not attached to the mandrel blank 10, and can also not be attached to the glass fiber cloth in step S3, so that the glass fiber cloth and the mandrel blank 10 are effectively isolated, and the glass fiber cloth can be easily peeled off from the mandrel blank 10. The material of the non-stick film can be selected according to actual needs, for example, a plastic wrap or the like. When the non-stick film is attached, only one layer is needed, and the non-stick film should be as smooth as possible and tightly attached to the mandrel blank 10.

[0026] S3, a glass fiber cloth is attached to the outer surface of the non-stick film, and the glass fiber cloth completely wraps the non-stick film; specifically, a glass fiber cloth with a suitable thickness can be selected according to actual needs. When a glass fiber cloth with a larger thickness is needed, the glass fiber cloth can be folded in advance before being attached. When the glass fiber cloth is attached, only one layer is needed, and the glass fiber cloth should be as smooth as possible and tightly attached to the non-stick film.

[0027] S4, a fastener is used to wrap the glass fiber cloth to press the glass fiber cloth tightly on the mandrel blank 10; specifically, a bandage or shrink film or the like is used to wrap the glass fiber cloth to fix the shape of the glass fiber cloth, and the shape of the glass fiber cloth is kept fixed during the baking process in step S5.

[0028] S5, the mandrel blank 10 with the fastener wrapped thereon is baked to shape the glass fiber cloth, as shown in Figure 2 ; specifically, the mandrel blank 10 with the fastener wrapped thereon is placed in a baking oven for baking. The baking time and temperature can be determined according to the thickness and size of the glass fiber cloth. When the carbon fiber product is a carbon fiber front fork of a carbon fiber bicycle, the baking temperature is 150°±5°, and the baking time is 1 hour. When it is another carbon fiber product, the baking temperature and time can be appropriately adjusted, or the required baking temperature and time can be determined through experimental tests.

[0029] S6, the fastener is removed; specifically, a blade can be used to cut the fastener, and then the fastener can be manually torn off.

[0030] S7, the mandrel blank 10 is taken out to form a hollow auxiliary mandrel 100, as shown in Figure 6 ; specifically, after the mandrel blank 10 is taken out, the auxiliary mandrel 100 has been shaped and has a certain strength after baking, and can play a supporting role to facilitate the attachment of the carbon fiber material on the auxiliary mandrel 100 to support the carbon fiber product.

[0031] The manufacturing method of the auxiliary mandrel 100 in this embodiment of the invention firstly involves making a mandrel blank 10 of a preset size and shape, and then sequentially attaching a non-adhesive film and a glass fiber cloth to the mandrel blank 10 to finally form an auxiliary mandrel 100 with a fixed shape. Carbon fiber products made using this auxiliary mandrel 100 are not easily deformed after being placed for a long time or subjected to external pressure due to the support of the auxiliary mandrel 100. At the same time, carbon fiber products are not prone to quality defects such as creases after the preform is formed and cured.

[0032] In this embodiment of the invention, step S7, removing the mandrel blank 10 to form a hollow auxiliary mandrel 100, includes:

[0033] S71. Cut along the outer contour of the cured fiberglass cloth and the non-adhesive film to expose the mandrel blank 10; specifically, it is sufficient to cut a portion along the outer contour of the fiberglass cloth to allow the mandrel blank 10 to be removed, such as... Figure 3 As shown, when the carbon fiber product is a carbon fiber fork, it can be cut along line c and line d. Because the fiberglass cloth is tough, the opening can be opened, so the mandrel blank 10 can be taken out directly.

[0034] S72. Remove the mandrel blank 10.

[0035] Of course, in other specific embodiments of the present invention, such as Figure 5 As shown, the fiberglass cloth can also be cut along line e, and the mandrel blank 10 can be pulled out along direction f. Alternatively, the mandrel blank 10 can be designed as a detachable structure, and the mandrel blank 10 can be pulled out in sections from the port of the cured fiberglass cloth without cutting.

[0036] In this embodiment of the invention, after step S72, which involves removing the mandrel blank 10, the method further includes:

[0037] S73. Remove the non-adhesive film to form an auxiliary mandrel 100 containing only fiberglass cloth. Specifically, the non-adhesive film is removed to make the auxiliary mandrel 100 lighter. Of course, the non-adhesive film can also be left in place, since the non-adhesive film is generally lightweight and has little impact on the weight of the auxiliary mandrel 100, and it can simplify the process.

[0038] In the embodiments of the present invention, for the case of cutting carbon fiber cloth to remove the mandrel blank 10, such as... Figure 4 As shown, the carbon fiber cloth can be preserved by adhesive tape at the opening 101. The tape can be a transparent tape or double-sided tape that can withstand a high temperature of 150 degrees Celsius. Alternatively, it can be left unattached and then attached when the auxiliary mandrel 100 is needed.

[0039] In embodiments of the present invention, such as Figure 1As shown, the carbon fiber product is a carbon fiber front fork of a carbon fiber bicycle, the mandrel blank 10 includes a vertical tube blank 1, and a left fork bone blank 2 and a right fork bone blank 3 extending to both sides along the vertical tube blank 1, the preset allowance includes a circumferential allowance, the length of the vertical tube blank 1, the length of the left fork bone blank 2 and the length of the right fork bone blank 3 are all greater than or equal to the length of the corresponding part of the carbon fiber product; the size of the vertical tube blank 1 on the circumference b, the size of the left fork bone blank 2 on the circumference b and the size of the right fork bone blank 3 on the circumference b are all smaller than the size on the circumference of the corresponding part of the carbon fiber product to form a circumferential allowance, the circumferential allowance of the vertical tube blank 1 on the circumference b, the circumferential allowance of the left fork bone blank 2 on the circumference b and the circumferential allowance of the right fork bone blank 3 on the circumference b are all greater than or equal to 1.5 millimeters and less than or equal to 3 millimeters. Specifically, since the auxiliary mandrel 100 is used to make the carbon fiber product, the size of the auxiliary mandrel 100 on the circumference b is reduced on the basis of the size of the carbon fiber product on the circumference b to leave an allowance for attaching the carbon fiber material, and the auxiliary mandrel 100 is made on the mandrel blank 10, so the size of the mandrel blank 10 on the circumference b is further reduced relative to the size of the auxiliary mandrel 100 on the circumference b to leave an allowance. For the carbon fiber front fork, the length of the vertical tube blank 1, the length of the left fork bone blank 2 and the length of the right fork bone blank 3 are all greater than or equal to the length of the corresponding part of the carbon fiber product, and in actual operation, the mandrel blank 10 is generally made longer, for example, the length of the vertical tube blank 1 is greater than 2 millimeters compared to the length of the vertical tube of the carbon fiber front fork, and the length of the left fork bone blank 2 and the length of the right fork bone blank 3 are all greater than 2 millimeters compared to the length of the left fork bone and the length of the right fork bone of the carbon fiber front fork, to ensure that the auxiliary mandrel 100 made is relatively long, which can be trimmed according to actual needs subsequently, and the circumferential allowance of the vertical tube blank 1 on the circumference, the circumferential allowance of the left fork bone blank 2 on the circumference and the circumferential allowance of the right fork bone blank 3 on the circumference are all greater than or equal to 1.5 millimeters and less than or equal to 3 millimeters, that is, the mandrel blank 10 needs to be inwardly shrunk on the basis of the carbon fiber front fork to be made by the above-mentioned circumferential allowance on the circumference.

[0040] In the embodiment of the present application, the thickness of the glass fiber cloth is 0.5 millimeters, and the specific thickness can be selected according to actual needs, the non-stick film is a preservative film, of course, as long as it can withstand 150 degrees high temperature and is not sticky, it can be a lighter flexible material, for example, it can also be a carbon fiber cloth. In the embodiment of the present application, the fastener is an OOP bandage, which can withstand 150 degrees high temperature, and in some other embodiments, the fastener can also be a shrink film that can withstand 150 degrees high temperature. The glass fiber cloth, the preservative film and the OOP bandage are all light in weight and low in cost, and the auxiliary mandrel 100 made of them can be controlled at 1-2 yuan each, which can be left in the carbon fiber product, and is very suitable for large-scale production and use.

[0041] The above is a detailed description of the manufacturing method of the auxiliary mandrel 100 provided by the embodiment of the present application. Next, a manufacturing method of a carbon fiber product provided by the embodiment of the present application is described in combination with Figures 1 to 6 The manufacturing method of the carbon fiber product provided by the embodiment of the present application is described in detail.

[0042] The manufacturing method of the carbon fiber product provided by the embodiment of the present application is described in detail.

[0043] S10, providing a wind pipe; the wind pipe is used to provide wind pressure to provide pressure to help molding when the preform is molded.

[0044] S20, placing the wind pipe in the hollow auxiliary mandrel 100 manufactured by the manufacturing method of the auxiliary mandrel 100; specifically, the wind pipe can be placed in the auxiliary mandrel 100.

[0045] S30, bonding the carbon fiber material on the auxiliary mandrel 100 to form a preform of the carbon fiber product; specifically, the carbon fiber material can be directly and smoothly attached to the auxiliary mandrel 100 with a certain supporting strength.

[0046] S40, placing the auxiliary mandrel 100 and the preform in a mold, heating the mold and introducing a gas with a certain pressure into the wind pipe to make the preform solidify and form; specifically, the heating temperature of the mold is 150°, and the wind pressure is 200PSI.

[0047] S50, taking out the wind pipe to form a carbon fiber product integrating the auxiliary mandrel 100 and the solidified preform.

[0048] The manufacturing method of the auxiliary mandrel 100 provided by the embodiment of the present application can attach the carbon fiber material on the auxiliary mandrel 100 and solidify to form a carbon fiber product integrating the auxiliary mandrel 100 and the solidified preform. Because of the support of the auxiliary mandrel 100, the preform of the carbon fiber product is not easy to deform after a long time or is extruded by external force, and the preform is not easy to have a fold or other quality problems after being molded and solidified.

[0049] In the embodiment of the present application, the step S20, the auxiliary mandrel 100 has an opening 101 formed by cutting along the outer contour to take out the mandrel blank 10, and the wind pipe is placed in the hollow auxiliary mandrel 100 manufactured by the manufacturing method of the auxiliary mandrel 100, which includes:

[0050] S201, placing the wind pipe in the hollow auxiliary mandrel 100 from the opening 101.

[0051] S202, bonding the opening 101 with adhesive tape, and the structure of the auxiliary mandrel 100 after bonding is shown in Figure 6 Specifically, the adhesive tape is a transparent adhesive tape or double-sided adhesive tape that can withstand 150 degrees of high temperature.

[0052] The above-described are only the preferred embodiments of the present application and are not intended in any way to limit the scope of the present application. Any equivalents for the technical features of the present application are intended to be encompassed in the scope of the present application.

Claims

1. A method of manufacturing a mandrel aid, characterized by, The auxiliary mandrel is used for a carbon fiber product, which is a carbon fiber front fork of a carbon fiber bicycle, and the manufacturing method comprises the following steps: manufacturing a mandrel blank, which is arranged according to the shape and size of the carbon fiber product and has a preset size margin relative to the size of the carbon fiber product; attaching a non-stick film to the outer surface of the mandrel blank, which completely wraps the mandrel blank; attaching a glass fiber cloth to the outer surface of the non-stick film, which completely wraps the non-stick film; winding the glass fiber cloth with a fastener to press the glass fiber cloth on the mandrel blank; baking the mandrel blank wound with the fastener to make the glass fiber cloth set; removing the fastener; taking out the mandrel blank to form the hollow auxiliary mandrel; wherein the step of taking out the mandrel blank to form the hollow auxiliary mandrel comprises: cutting the glass fiber cloth and the non-stick film along the outer contour of the cured glass fiber cloth to expose the mandrel blank; taking out the mandrel blank.

2. The method of claim 1, wherein The step of taking out the mandrel blank further comprises: taking out the non-stick film to form the auxiliary mandrel containing only the glass fiber cloth.

3. The method of claim 1, wherein the auxiliary mandrel is made by, The mandrel blank comprises a vertical tube blank and left and right fork bone blanks extending to both sides along the vertical tube blank, the preset size margin comprises a circumferential margin, the length of the vertical tube blank, the length of the left fork bone blank and the length of the right fork bone blank are all greater than or equal to the length of the corresponding part of the carbon fiber product; the circumferential size of the vertical tube blank, the circumferential size of the left fork bone blank and the circumferential size of the right fork bone blank are all less than the circumferential size of the corresponding part of the carbon fiber product to form the circumferential margin, the circumferential margin of the vertical tube blank in the circumferential direction, the circumferential margin of the left fork bone blank in the circumferential direction and the circumferential margin of the right fork bone blank in the circumferential direction are all greater than or equal to 1.5 mm and less than or equal to 3 mm.

4. The method of claim 3, wherein the auxiliary mandrel is made by, The baking temperature is 150°±5°, and the baking time is 1 hour.

5. The method of claim 4, wherein the auxiliary mandrel is formed by, The thickness of the glass fiber cloth is 0.5 mm.

6. The method of claim 1, wherein the auxiliary mandrel is made by, The non-stick film is a fresh-keeping film.

7. The method of claim 1, wherein the auxiliary mandrel is made by, The fastener is an OOP binding tape or a shrink film.

8. A method of producing a carbon fiber product, characterized by, The method comprises the following steps: providing a wind pipe; placing the wind pipe in the hollow auxiliary mandrel manufactured by the manufacturing method of the auxiliary mandrel according to any one of claims 1-7; attaching a carbon fiber material to the auxiliary mandrel to form a preform of the carbon fiber product; placing the auxiliary mandrel and the preform in a mold, heating the mold and introducing a gas with a certain pressure into the wind pipe to make the preform cured and formed; taking out the wind pipe to form the carbon fiber product integrated with the auxiliary mandrel and the cured preform.

9. The method of producing a carbon fiber product according to claim 8, wherein The auxiliary mandrel has an opening formed by cutting along the outer contour to take out the mandrel blank, and placing the wind pipe in the hollow auxiliary mandrel manufactured by the manufacturing method of the auxiliary mandrel according to any one of claims 1-7 comprises: placing the wind pipe in the hollow auxiliary mandrel from the opening; adhering the opening with adhesive tape.

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