Preparation method of low-cost high-performance brake disc preform

Abstract

The invention discloses a preparation method of a low-cost high-performance brake disc preform, which comprises the following steps: S1, mold selection and treatment: a cylindrical mold is selected as a support matrix for needling molding, and the diameter of a treated cylinder is less than or equal to the inner diameter of a target brake disc preform; s2, laying and needling a base layer, namely laying a layer of carbon cloth and a layer of net tire on the outer side of the cylindrical mold in a staggered and superposed manner along the circumferential direction according to a manner that a layer of carbon cloth and a layer of net tire are taken as a group of base laying units, and needling and fixing the base laying units by adopting needling equipment after each group of base laying units is laid; and S3, laying a chopped fiber reinforced layer: after needling of each group of basic laying layer units in the S2 is completed, uniformly laying a layer of chopped carbon fibers on one side, far away from the carbon cloth, of the net tire. According to the method, near-size forming is achieved while the performance is guaranteed, large-amount cutting in the later period is not needed, the raw material cost is reduced, and meanwhile the yield of products is increased.

Description

Technical Field

[0001] This invention relates to the field of brake disc manufacturing technology, specifically a method for preparing a low-cost, high-performance brake disc preform. Background Technology

[0002] The preparation of carbon-ceramic brake discs mainly involves two aspects: the preparation of the preform and the ceramization of the preform. Currently, the preparation of carbon-ceramic brake disc preforms primarily involves flat plate needle punching, where carbon cloth and mesh are alternately stacked and needle punched. Excess material is then removed by cutting, resulting in approximately one-third material waste.

[0003] The existing technology for preparing brake disc preforms not only requires cutting off the weaker parts at the edges, but also requires using special tools to remove the center circle to form the shape of a brake disc. The limitation of this method is that the waste costs are high, resulting in high production costs. Moreover, removing the center circle with special tools increases the difficulty of operation and risks reducing the yield. Summary of the Invention

[0004] The purpose of this invention is to provide a low-cost, high-performance brake disc preform preparation method to solve the problems in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing a low-cost, high-performance brake disc preform, comprising the following steps:

[0006] S1. Mold selection and processing: Select a cylindrical mold as the support base for needle punching. The diameter of the processed cylinder is less than or equal to the inner diameter of the target brake disc preform.

[0007] S2, Base layer laying and needle punching: One layer of carbon cloth and one layer of mesh are laid as a base layer unit, and are laid alternately along the circumference on the outside of the cylindrical mold. After each base layer unit is laid, it is fixed by needle punching.

[0008] S3, Short chopped fiber reinforcement layer laying: After the needle punching of each basic layup unit in S2 is completed, a layer of short chopped carbon fiber is evenly laid on the side of the mesh away from the carbon cloth.

[0009] S4. Cyclic coiling and forming: Repeat steps S2-S3, continuously lay up the basic layer unit, needle punch and short carbon fiber on the outside of the cylindrical mold until the outer diameter of the formed structure reaches the outer diameter of the target brake disc preform in the range of 0-0.2mm.

[0010] S5. Thickness Cutting and Demolding: Using a CNC diamond saw blade cutting machine, the forming structure in S4 is circumferentially cut according to the thickness requirement of ±0.1mm of the target brake disc preform. After cutting, the preform is demolded from the cylindrical mold by a hydraulic ejection device to obtain the brake disc preform.

[0011] Preferably, in step S1, the cylindrical mold is made of wood and covered with a layer of EVA cotton. The EVA cotton has a thickness of 10-15mm, a hardness of 40-70, and a surface roughness Ra≤1.6μm.

[0012] Preferably, in step S2, the carbon cloth is polyacrylonitrile-based carbon fiber cloth, and the mesh is polyacrylonitrile-based carbon fiber mesh; the needle density of the needle punching is 30-35 needles / cm. 2 The needle depth for acupuncture is 12-17mm.

[0013] Preferably, in step S3, the length of the chopped carbon fiber is 5-10 mm, and the areal density is 20-80 g / m³. 2 Furthermore, during the laying process, an airflow distribution device ensures that the short-cut carbon fibers are free from agglomeration and voids.

[0014] Preferably, in step S4, during the cyclic burring process, after every 5 sets of basic layup units are laid, the outer diameter of the formed structure is measured by laser to ensure that the outer diameter deviation is within the control range.

[0015] Preferably, in step S5, the feed speed during the cutting process is 50-100 mm / min, and compressed air is used for cooling during cutting, with a cooling airflow velocity of 12-17 m / s.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] 1. The process involves using a cylindrical needle punch, where a cylinder is used as the starting support point for the needle punching. The outer diameter of the treated cylinder is less than or equal to the inner diameter of the brake disc preform. A layer of carbon cloth and a layer of mesh are alternately needle punched. After each layer of carbon cloth and mesh, a layer of chopped carbon fiber is evenly laid on the mesh. The fibers of the upper and lower layers interweave and interlock, which greatly increases the interlayer bonding force and mechanical interlocking effect, thereby significantly improving the interlaminar shear strength and anti-delamination ability of the material.

[0018] 2. Short fibers help to more tightly "bundle" the fibers of different layups together, resulting in a denser and more uniform preform structure after needle punching. This lays a good foundation for a higher-quality subsequent carbonization and densification process. The preform is needle-punched to the required outer diameter, and then cut to the required thickness. The demolded product is the final product. Sufficiently long cylindrical molds enable mass production; the process is simple and easy to manufacture, and the performance remains unchanged, significantly reducing production costs.

[0019] 3. While ensuring performance, near-size molding eliminates the need for extensive post-processing, reducing raw material costs and increasing product yield. Attached Figure Description

[0020] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0021] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0023] Please see Figure 1 In this embodiment of the invention, a method for preparing a low-cost, high-performance brake disc preform includes the following steps:

[0024] S1. Mold selection and processing: Select a cylindrical mold as the support base for needle punching. The diameter of the processed cylinder is less than or equal to the inner diameter of the target brake disc preform.

[0025] S2. Base layer laying and needle punching: A base layer unit consisting of one layer of carbon cloth and one layer of mesh (which can balance the strength and toughness of the precast body and avoid the performance defects of a single material) is laid in an alternating manner along the circumferential direction on the outside of the cylindrical mold. After each base layer unit is laid, it is fixed by needle punching using a needle punching device.

[0026] S3, Short chopped fiber reinforcement layer laying: After the needle punching of each basic layup unit in S2 is completed, a layer of short chopped carbon fiber is evenly laid on the side of the mesh away from the carbon cloth.

[0027] S4. Cyclic coil forming: Repeat steps S2-S3, continuously lay up the basic layer unit, needle punch and short carbon fiber on the outside of the cylindrical mold until the outer diameter of the formed structure reaches the outer diameter of the target brake disc preform in the range of 0-0.2mm, leaving a small margin to cope with subsequent cutting errors.

[0028] S5. Thickness Cutting and Demolding: Using a CNC diamond saw blade cutting machine, the forming structure in S4 is circumferentially cut according to the thickness requirement of ±0.1mm of the target brake disc preform. After cutting, the preform is demolded from the cylindrical mold by a hydraulic ejection device to obtain the brake disc preform.

[0029] In step S1, the cylindrical mold is made of wood with a layer of EVA cotton attached. The EVA cotton is 10-15mm thick, has a hardness of 40-70, and a surface roughness Ra≤1.6μm. This reduces wear on the preform structure during demolding and ensures tight adhesion between the carbon cloth and mesh during layering, preventing air bubbles or voids caused by the rough mold surface. The cylindrical structure directly matches the final shape of the brake disc ring, eliminating the need for later removal of the center circle. Using a cylindrical mold (outer diameter ≤ inner diameter of the target preform) directly matches the final shape of the brake disc "ring," replacing traditional flat plate needle punching. Traditional processes require later cutting of edges and removal of the center circle, resulting in a waste of 1 / 3 of the material. This method directly avoids forming unnecessary parts through the mold structure, reducing processing losses from the source.

[0030] In S2, the carbon cloth is polyacrylonitrile-based carbon fiber cloth, and the mesh is polyacrylonitrile-based carbon fiber mesh; the needle density of the needle punching is 30-35 needles / cm. 2 The needle-punching depth is 12-17mm, with carbon fiber cloth providing a high-strength skeleton and a mesh reinforcing the structural toughness; each set is needle-punched (needle density 30-35 needles / cm). 2 (Needle depth 12-17mm) to make the fibers interlock, forming a preliminary mechanical interlock and preventing interlayer separation.

[0031] In S3, the length of the short-cut carbon fiber is 5-10 mm, and the areal density is 20-80 g / m². 2 This method achieves both densification and structural rigidity without excessive fiber content. Furthermore, the airflow distribution device ensures that the chopped carbon fibers are free of agglomeration and voids during installation, reducing interlayer interfaces and further mitigating the risk of delamination. The chopped fibers further connect adjacent layers, strengthening interlayer bonding and filling tiny gaps, thus enhancing the overall density of the precast structure.

[0032] In S4, during the cyclic burring process, after every 5 sets of basic layup units are laid, the outer diameter of the formed structure is measured by laser to ensure that the outer diameter deviation is within the control range.

[0033] In S5, the feed speed during the cutting process is 50-100 mm / min. Compressed air is used for cooling during cutting, and the cooling airflow speed is 12-17 m / s. This can prevent carbon fiber oxidation caused by high temperature during cutting, and at the same time prevent the saw blade from overheating and wearing, ensuring a smooth cutting surface.

[0034] The working principle of this invention is as follows: A cylindrical needle punch is used, with the cylinder serving as the starting support point for the needle punching. The outer diameter of the treated cylinder is less than or equal to the inner diameter of the brake disc preform. A layer of carbon cloth and a layer of mesh are alternately needle punched. After each layer of carbon cloth and mesh, a layer of chopped carbon fiber is evenly laid on the mesh. The fibers of the upper and lower layers interweave and connect, greatly increasing the interlayer bonding force and mechanical interlocking effect, thereby significantly improving the interlaminar shear strength and anti-delamination ability of the material. The short fibers help to more tightly "bundle" the fibers of different layers together, making the structure of the needle-punched preform more dense and uniform, laying a good foundation for a higher-quality subsequent carbonization and densification process. The needle punching is continued until the required outer diameter of the brake disc preform is reached. Finally, it is cut according to the required thickness of the brake disc, and the demolded product is the final product.

[0035] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a low-cost, high-performance brake disc preform, characterized in that, Includes the following steps: S1. Mold selection and processing: Select a cylindrical mold as the support base for needle punching. The diameter of the processed cylinder is less than or equal to the inner diameter of the target brake disc preform. S2, Base layer laying and needle punching: One layer of carbon cloth and one layer of mesh are laid as a base layer unit, and are laid alternately along the circumference on the outside of the cylindrical mold. After each base layer unit is laid, it is fixed by needle punching. S3, Short chopped fiber reinforcement layer laying: After the needle punching of each basic layup unit in S2 is completed, a layer of short chopped carbon fiber is evenly laid on the side of the mesh away from the carbon cloth. S4. Cyclic coiling and forming: Repeat steps S2-S3, continuously lay up the basic layer unit, needle punch and short carbon fiber on the outside of the cylindrical mold until the outer diameter of the formed structure reaches the outer diameter of the target brake disc preform in the range of 0-0.2mm. S5. Thickness Cutting and Demolding: Using a CNC diamond saw blade cutting machine, the forming structure in S4 is circumferentially cut according to the thickness requirement of ±0.1mm of the target brake disc preform. After cutting, the preform is demolded from the cylindrical mold by a hydraulic ejection device to obtain the brake disc preform.

2. The method for preparing a low-cost, high-performance brake disc preform according to claim 1, characterized in that, In S1, the cylindrical mold is made of wood and covered with a layer of EVA cotton. The EVA cotton has a thickness of 10-15mm, a hardness of 40-70, and a surface roughness Ra≤1.6μm.

3. The method for preparing a low-cost, high-performance brake disc preform according to claim 1, characterized in that, In S2, the carbon cloth is polyacrylonitrile-based carbon fiber cloth, and the mesh is polyacrylonitrile-based carbon fiber mesh; the needle density of the needle punching is 30-35 needles / cm. 2 The needle depth for acupuncture is 12-17mm.

4. The method for preparing a low-cost, high-performance brake disc preform according to claim 1, characterized in that, In S3, the length of the short-cut carbon fiber is 5-10 mm, and the areal density is 20-80 g / m². 2 Furthermore, during the laying process, an airflow distribution device ensures that the short-cut carbon fibers are free from agglomeration and voids.

5. The method for preparing a low-cost, high-performance brake disc preform according to claim 1, characterized in that, In S4, during the cyclic burring process, after every 5 sets of basic layup units are laid, the outer diameter of the formed structure is measured by laser to ensure that the outer diameter deviation is within the control range.

6. The method for preparing a low-cost, high-performance brake disc preform according to claim 1, characterized in that, In S5, the feed speed during the cutting process is 50-100 mm / min, and compressed air is used for cooling during cutting, with a cooling airflow speed of 12-17 m / s.

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