Carbon fiber composite molding die and method

Abstract

The present invention discloses a carbon fiber composite molding die and a method thereof, the die includes a curing die and a preform shell mold which can be detachably joined together, the curing die is provided with a curing cavity for receiving the preform shell mold, the preform shell mold is provided with a preform cavity conforming to the structure of the molding product, the inner wall of the preform cavity is laid with a number of carbon fiber composite preform layers to form the preform of the product, a nylon duct is provided in the preform cavity, and the nylon duct supports the preform layer to be in close contact with the inner wall of the preform cavity when filled with air. The present invention provides a carbon fiber composite molding die and a method thereof, which lays layers from the outside to the inside, directly reinforcing the local areas that need internal reinforcement, ensuring the overall strength of the molding product, and making the product surface smooth and flat, thereby eliminating the subsequent surface smoothing process after molding of the product, and saving labor costs.

Description

[Technical field]

[0001] The present invention relates to the field of carbon fiber technology, and in particular to a molding tool and method for carbon fiber composite materials. [Background technology]

[0002] Carbon fiber composite materials have the advantages of light weight and high strength, and are widely used. Especially in the field of high-end bicycles, as people's living standards improve, the demand for high-end bicycles increases, and bicycles become more popular, which leads to a demand for lighter cycling equipment. Carbon fiber is ideal for manufacturing lightweight bicycles due to its light weight and strength characteristics.

[0003] In the prior art, when carbon fiber composite materials are manufactured, a carbon fiber thread layer is usually laid in the hardening cavity of a metal mold, and then hardened and molded in a high-temperature heated mold. However, this process is complicated and inefficient, and requires the use of a mold release agent for demolding, and there is a residue (excess resin) in the metal mold after demolding. Different product parts have different requirements for the hardening cavity structure of the metal mold, so multiple metal molds need to be opened, which is costly. Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention provides a molding die and method for carbon fiber composite materials to solve the above problems. [Means for solving the problem]

[0005] To achieve the above objectives, the present invention adopts the following technical solutions.

[0006] A molding die for a carbon fiber composite material, comprising a curing die and a preform shell mold that can be detachably joined together, the curing die having a curing cavity for accommodating the preform shell mold, the preform shell mold having a preform cavity that matches the structure of a molded product, a number of preform layers of a carbon fiber composite material for forming a preform of a product laid on the inner wall of the preform cavity, a nylon duct provided within the preform cavity, and the nylon duct supports the preform layer so as to be in close contact with the inner wall of the preform cavity when filled with air.

[0007] Preferably, the preform shell mould comprises a number of separate shell moulds which are joined together.

[0008] Preferably, two adjacent sets of the split shell moulds are detachably joined together by an engagement structure.

[0009] Preferably, the hardening mold includes an upper hardening mold and a lower hardening mold, the upper hardening mold is installed directly above the lower hardening mold so as to be able to rise and fall, an upper hardening groove is provided on the bottom side of the upper hardening mold, and a lower hardening groove is provided on the top side of the lower hardening mold, and the upper hardening groove and the lower hardening groove are fitted together to form a hardening cavity for accommodating the preform shell mold.

[0010] Preferably, the preform layer comprises several layers and employs carbon fiber composite material.

[0011] Preferably, the hardening mold is made of a metal material.

[0012] Preferably, the preform shell mold is made of a plastic material.

[0013] A method for forming a carbon fiber composite material, comprising the steps of: precasting a number of separate shell molds, laying a carbon fiber composite material inside the separate shell molds to form a preform layer; joining the number of separate shell molds to form a preform shell mold, and fitting the preform layers inside the separate shell molds of each set closely together to form a preform for a product; and inserting a nylon duct inside the preform in advance in step S2; filling the nylon duct with air, holding the pressure for several seconds, expanding the nylon duct, and forming the preform layer into the preform. The process includes step S3 of supporting the preform shell mold so that it is in close contact with the inner wall of the preform cavity of the reforming shell mold; step S4 of leaving the preform shell mold in the curing cavity of the curing mold, heating the curing mold while pressurizing the nylon duct, simultaneously carrying out the heating process and the pressurizing process, continuing until the temperature and pressure reach the requirements for curing molding, and continuing the dwell pressure until the preform is completely molded and cured to form a first product; and step S5 of opening the curing mold, peeling the preform shell mold from the surface of the first product, taking out the first product, and obtaining a finished product after machining and surface treatment.

[0014] By adopting the above technical solutions, the present invention has the following advantages over the background art:

[0015] 1. The present invention provides a molding die and method for carbon fiber composite material, in which a preform layer of carbon fiber composite material is first laid inside each separate shell mold, and then the separate shell molds of each stage are joined together to form a preform shell mold, and then the preform shell mold is placed into a hardening mold for hardening molding, and the preform cavity structure of the preform shell mold is compatible with the structure of the product to be formed. When laying the carbon fiber composite material, layers are laid from the outside to the inside, so as to directly reinforce the local areas that need internal reinforcement, and ensure the overall strength of the molded product. At the same time, the product surface is made smooth and flat, which eliminates the subsequent surface smoothing treatment process after molding of the product and saves labor costs.

[0016] 2. The carbon fiber composite molding die and method of the present invention are easy to demold, and the preform shell mold can be removed without the need for a release agent. The plastic preform shell mold is directly peeled off from the cured molded product, leaving no residue in the cured mold, allowing it to be used continuously. There is no need to clean the mold even after long-term use, the operation is simple, and the product is not easily damaged. Compared with traditional processes, the production process is simplified, the process time is shortened, and the production costs of the enterprise are reduced.

[0017] 3. The present invention provides a carbon fiber composite molding mold and method, which can adjust the preform cavity structure of the preform shell mold according to the needs of actual product structure, and can use a general-purpose mold as the hardening mold. Compared with the hardening mold structure that adjusts metal materials, the cost and difficulty of making a preform shell mold made of plastic materials are both lower, thereby reducing the production costs of enterprises. [Brief description of the drawings]

[0018] [Figure 1] 2 is a flow chart of the molding process of the present invention. [Diagram 2] FIG. 2 is a structural schematic diagram of a molding die of the present invention. [Diagram 3] FIG. 2 is a structural schematic diagram of the preform shell mold of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] In order to make the objectives, technical solutions and advantages of the present invention clearer, the following will further describe the present invention in conjunction with figures and examples. It should be understood that the specific embodiments described herein are only for the purpose of illustrating the present invention, and are not intended to limit the present invention.

[0020] Working Example As shown in Figures 1 to 3, the present invention discloses a molding die for carbon fiber composite material, and the product of carbon fiber composite material molding in this embodiment includes, but is not limited to, bicycle rims, bicycle frames, bicycle handlebars, etc., and in this embodiment, a bicycle rim is specifically taken as an example. The molding die includes a curing die 1 and a preform shell mold 2 that can be detachably joined together, the curing die 1 is provided with a curing cavity 11 for accommodating the preform shell mold 2, the preform shell mold 2 is provided with a preform cavity 21 that is suitable for the structure of the molding product, the inner wall of the preform cavity 21 is laid with a number of preform layers 3 of carbon fiber composite material to form the preform of the product, a nylon duct 4 is provided in the preform cavity 21, and the nylon duct 4 supports the preform layer 3 to be in close contact with the inner wall of the preform cavity 21 when filled with air.

[0021] The preform shell mold 2 includes several pairs of separate shell molds to be joined together. Two adjacent pairs of separate shell molds are detachably joined together by an engagement structure, which includes a fastener and a locking hole, and the fastener is inserted into the locking hole to lock and fix the two adjacent pairs of separate shell molds together.

[0022] The hardening mold 1 includes an upper hardening mold 12 and a lower hardening mold 13. The upper hardening mold 12 is installed directly above the lower hardening mold 13 so that it can be raised and lowered. An upper hardening groove is provided on the bottom side of the upper hardening mold 12, and a lower hardening groove is provided on the top side of the lower hardening mold 13. The upper hardening groove and the lower hardening groove are fitted together to form a hardening cavity 11 for accommodating the preform shell mold 2.

[0023] The preform layer 3 includes several layers and adopts carbon fiber composite material, and the number of layers of the preform layer 3 at different positions can be adjusted according to actual needs, for example, more layers can be laid in local areas that need reinforcement.

[0024] The hardening mold 1 is made of a metal material, and the preform shell mold 2 is made of a plastic material.

[0025] The present invention further discloses a method for forming a carbon fiber composite material, which includes a step S1 of precasting several sets of separate shell molds, laying a carbon fiber composite material inside the separate shell molds to form a preform layer 3, a step S2 of joining several sets of separate shell molds to form a preform shell mold 2, and closely fitting the preform layers 3 inside each set of separate shell molds to form a preform of a product, and inserting a nylon duct 4 into the inside of the preform in advance, and filling the nylon duct 4 with air and keeping the pressure for several seconds to expand the nylon duct 4 to form the preform layer. The process includes step S3 of supporting the preform shell mold 2 so that it is in close contact with the inner wall of the preform cavity 21 of the shell mold 2; step S4 of leaving the preform shell mold 2 in the curing cavity 11 of the hardening mold 1, heating the hardening mold 1 while pressurizing the nylon duct 4, performing the heating process and the pressurizing process simultaneously, continuing until the temperature and pressure reach the requirements for hardening molding, and continuing the pressure holding until the preform is completely molded and hardened to form a first product; and step S5 of opening the hardening mold 1, peeling the preform shell mold 2 from the surface of the first product, taking out the first product, and obtaining a finished product after machining and surface treatment.

[0026] In this embodiment, the molded product is specifically taken as a bicycle rim, the separated shell mold 2 includes three sets of upper shell mold 22, lower shell mold 23, and outer rim shell mold 24, the upper shell mold 22 has a first fastener on the inside, the lower shell mold 23 has a first locking hole on the inside that matches the first fastener, the upper shell mold 22 and the lower shell mold 23 have second locking holes on the outside, the outer rim shell mold 24 has second fasteners on both ends that match the second locking holes, and the preform layer 3 includes four sets of upper preform layer, lower preform layer, outer rim preform layer, and inner rim preform layer. The specific molding method includes the following steps:

[0027] 1) The upper shell mold 22, the lower shell mold 23 and the outer rim shell mold 24 are precast, and an upper preform layer, a lower preform layer and an outer rim preform layer are laid inside the upper shell mold, the lower shell mold and the outer rim shell mold 24, respectively.

[0028] 2) The outer rim shell mold 24 and the inner rim preform layer are left at both ends of the inside of the lower shell mold 23 and joined together, and a nylon duct is inserted between the outer rim shell mold 24, the inner rim preform layer, and the lower shell mold 23.

[0029] 3) The inner rim preform layer is laid and formed in advance using an external preform jig, and the laid and molded inner rim preform layer is left on the lower shell mold 23 and combined, and the upper shell mold 22, the lower shell mold 23 and the outer rim shell mold 24 are joined to form the preform shell mold 2, and the upper preform layer, the lower preform layer, the outer rim preform layer and the inner rim preform layer are tightly fitted together to form a rim preform.

[0030] Here, the upper and lower preform layers become thinner closer to the inner rim preform layer during the laying process, making it easier to flatly adhere the inner rim preform layer to the upper and lower preform layers, and the outer rim preform layer extends to both sides during the laying process, making it easier to flatly adhere the outer rim preform layer to the upper and lower preform layers, ensuring the strength of the bonded part of the rim after molding. At the same time, in the laying process of the preform layers, they are laid thicker in localized positions, such as the brake areas and spoke hole areas, to provide localized reinforcement.

[0031] The preform shell mold 2 is further provided with a mounting hole (not shown) penetrating the inside and outside of the preform shell mold for mounting a tire air valve member, and the end of the nylon duct 3 is pulled out from the mounting hole and connected to the air valve member.

[0032] 4) Air is filled into the nylon duct 4 by the air valve member, and the pressure is maintained for several seconds to expand the nylon duct, thereby supporting the preform layer so that it is in close contact with the inner wall of the preform cavity of the preform shell mold.

[0033] 5) The preform shell mold 2 is left in the curing cavity 11 of the curing die 1, and the curing die 1 is heated while the nylon duct 4 is pressurized. The heating process and the pressurizing process are carried out simultaneously until the temperature and pressure reach 145°C to 155°C and 1.5MPa to 1.8MPa, respectively, and the rim preform is completely molded and cured to form a rim.

[0034] 6) The hardening mold 1 is opened, the preform shell mold 2 is peeled off from the surface of the rim, the rim is taken out, and after machining and surface treatment, the finished rim is obtained.

[0035] The above description is merely a preferred specific embodiment of the present invention, and the scope of protection of the present invention is not limited thereto. Any modifications or replacements that can be easily conceived by any person skilled in the art within the technical scope of the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. 1. A molding die for a carbon fiber composite material, comprising: a curing die; and a preform shell mold which can be detachably joined together, wherein the curing die is provided with a curing cavity for accommodating the preform shell mold, and the preform shell mold is provided with a preform cavity which is adapted to a structure of a molded product, a preform layer for forming a preform of a product is laid on an inner wall of the preform cavity, and a nylon duct is provided within the preform cavity, and the nylon duct supports the preform layer so as to be in close contact with the inner wall of the preform cavity when filled with air.

2. The preform shell mold is characterized in that it includes several sets of separate shell molds that are joined together. A mold for molding the carbon fiber composite material according to claim 1.

3. The two adjacent sets of the separate shell molds are detachably joined together by an engagement structure. A mold for molding the carbon fiber composite material according to claim 2.

4. The hardening mold includes an upper hardening mold and a lower hardening mold, the upper hardening mold is installed directly above the lower hardening mold so as to be movable up and down, an upper hardening groove is provided on the bottom side of the upper hardening mold, and a lower hardening groove is provided on the top side of the lower hardening mold, and the upper hardening groove and the lower hardening groove are fitted together to form a hardening cavity for accommodating the preform shell mold. A mold for molding the carbon fiber composite material according to claim 1.

5. The preform layer includes several layers and is characterized in that it adopts carbon fiber composite material. A mold for molding the carbon fiber composite material according to claim 1.

6. The hardening mold is characterized by adopting a metal material. A mold for molding the carbon fiber composite material according to claim 1.

7. The preform shell mold is made of a plastic material. A mold for molding the carbon fiber composite material according to claim 1.

8. A method for molding the carbon fiber composite material according to any one of claims 1 to 7, Step S1: precasting a number of separate shell molds and laying a carbon fiber composite material on the inside of the separate shell molds to form a preform layer; Step S2: joining several sets of the split shell molds to form a preform shell mold, and fitting the inner preform layers of each set of the split shell molds closely to form a preform of a product, and inserting a nylon duct into the inside of the preform; Step S3: filling the nylon duct with air and holding the pressure for several seconds to expand the nylon duct and support the preform layer in close contact with the inner wall of the preform cavity of the preform shell mold; Step S4: leave the preform shell mold in the curing cavity of the curing mold, heat the curing mold and pressurize the nylon duct at the same time, perform the heating process and the pressurizing process simultaneously, continue until the temperature and pressure reach the curing molding requirement, and continue the dwell pressure until the preform is completely molded and cured to form a first product; and step S5 of opening the curing mold, peeling off the preform shell mold from the surface of the initial product, taking out the initial product, and obtaining a finished product after machining processing.

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