A manufacturing method of a brake disc body special for a new energy electric vehicle

Abstract

The application discloses a manufacturing method of a brake disc body special for new energy electric vehicles and relates to the technical field of brake disc manufacturing. The manufacturing method of the brake disc body special for new energy electric vehicles is specifically as follows: S1, outsourcing gray iron 250 brake discs are taken as cast bodies for subsequent machining operations; S2, according to product needs and cast body conditions, the cast body is subjected to turning machining operations; and S3, nitrogen-carbon co-permeation operations are performed. The manufacturing method of the brake disc body special for new energy electric vehicles has a finished product surface compound layer thickness of 6-8 um, which is sufficient to meet the needs of new energy electric vehicle brake discs. The loose layer of the finished product is a discontinuous loose layer, 90% of which is Fe3O4, and the rest is graphite. Most of the brake discs in the prior art are continuous loose layers. Therefore, in terms of the friction coefficient, the finished product of the application is higher than the brake discs in the prior art, and the safety factor is relatively high during use.

Description

Technical Field

[0001] This invention relates to the field of brake disc manufacturing technology, specifically a method for manufacturing a brake disc body for new energy electric vehicles. Background Technology

[0002] New energy electric vehicles consist of: an electric drive and control system, mechanical systems such as drive transmission, and working devices to perform predetermined tasks. The electric drive and control system is the core of an electric vehicle and the biggest difference between it and an internal combustion engine vehicle. The electric drive and control system comprises a drive motor, a power supply, and a speed control device for the motor. Other components of an electric vehicle are basically the same as those of an internal combustion engine vehicle.

[0003] New energy electric vehicles have a kinetic energy recovery system, so they can brake as soon as they release the accelerator. In actual use, they basically do not need to step on the brake pedal. Therefore, the number of friction cycles of the brake discs of new energy electric vehicles is less than that of the brake discs of internal combustion engine vehicles, and they are basically not needed.

[0004] Currently, new energy electric vehicles use the same brake discs as internal combustion engine vehicles. Internal combustion engine brake discs need to ensure that the compound layer on the surface is above 10um. However, after multiple experiments, the inventors found that a compound layer of 6-8um on the surface of the brake discs of new energy electric vehicles is sufficient to meet the requirements. Since the standard needs to be changed, if the existing manufacturing process is still used, it will lead to a waste of manufacturing costs, increasing costs and reducing production efficiency. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a manufacturing method for a dedicated brake disc body for new energy electric vehicles. This method solves the problem that while new energy electric vehicles use the same brake discs as internal combustion engine vehicles, internal combustion engine brake discs require a compound layer of at least 10µm on their surface. However, after numerous experiments, the inventors discovered that a compound layer of 6-8µm is sufficient for new energy electric vehicle brake discs. Because this requires a change in standards, continuing to use existing manufacturing processes would lead to wasted manufacturing costs, increased expenses, and reduced production efficiency.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the present invention provides the following technical solution: a method for manufacturing a brake disc body specifically for new energy electric vehicles, the specific operation of which is as follows:

[0009] S1. Purchase 250mm gray iron brake discs as the casting body for subsequent machining operations;

[0010] S2. Based on product requirements and the condition of the casting body, perform turning operations on the casting body;

[0011] S3. Perform the modified nitriding / carbonodriding operation with the following specific parameters:

[0012] The reaction temperature is 540-590℃, the holding time is 1-2.5h, the flow rate of ammonia and nitrogen is 30-50m3 / h, and the flow rate of CO2 is 2-8m3 / h.

[0013] S4. Remove the casting body to complete the manufacturing operation of the brake disc body.

[0014] Preferably, in step S3, the reactor used for the nitrocarburizing operation is a muffle-less square bell furnace.

[0015] Preferably, in step S4, the nitrogen-carbon compound layer on the surface of the finished product is 6-8 μm, and the loose layer on its surface is discontinuous. 90% of the loose layer is Fe3O4 oxide, and the rest is exposed graphite.

[0016] (III) Beneficial Effects

[0017] This invention provides a method for manufacturing a brake disc body specifically for new energy electric vehicles. It possesses the following characteristics:

[0018] Beneficial effects:

[0019] (1) The manufacturing method of the brake disc body for new energy electric vehicles has a compound layer thickness of 6-8 μm on the surface of the finished product, which is sufficient to meet the needs of brake discs for new energy electric vehicles. The loose layer of the finished product of the present invention is a discontinuous loose layer, 90% of which is Fe3O4 and the rest is graphite. In contrast, most brake discs in the prior art are continuous loose layers. Therefore, in terms of friction coefficient, the finished product of the present invention is higher than that of the brake discs in the prior art, and the safety factor is relatively high when used.

[0020] (2) The manufacturing method of the brake disc body for new energy electric vehicles can complete the nitrocarburizing operation in only 1-2.5 hours by modifying the nitrocarburizing operation parameters (in the prior art, the nitrocarburizing operation requires 3-7 hours). Due to the shortened time, the deformation after the nitrocarburizing operation is relatively small, resulting in higher precision of the finished product. No additional stress relief process is required. While ensuring the quality of the finished product, the manufacturing time is reduced and the production efficiency is improved.

[0021] (3) The manufacturing method of the brake disc body for new energy electric vehicles has a relatively high casting body temperature after the nitrocarburizing operation, generally 390-380℃ (in the prior art, the casting body temperature after the nitrocarburizing operation is 135-145℃). If other high-temperature processes are required in the future, the energy consumed by heating will be saved (if there are no high-temperature processes in the future, it can be cooled naturally, which will also result in additional cost expenditures. At the same time, heat energy can be recovered during the cooling process). If there are unqualified products, due to the relatively high current temperature, remelting and remanufacturing will greatly reduce energy consumption. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the process of the present invention;

[0023] Figure 2 This is a schematic diagram of a process in the prior art;

[0024] Figure 3 This is a schematic diagram comparing the parameters of the nitriding operation in this invention and the prior art;

[0025] Figure 4 This is an image of the surface layer of the finished product of this invention under an electron microscope. Detailed Implementation

[0026] 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 some embodiments of the present invention, and not all embodiments. 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.

[0027] Please see Figure 1-4 This invention provides a technical solution: a method for manufacturing a brake disc body specifically for new energy electric vehicles, the specific operation of which is as follows:

[0028] S1. Purchase 250mm gray iron brake discs as the casting body for subsequent machining operations;

[0029] S2. Based on product requirements and the condition of the casting body, perform turning operations on the casting body;

[0030] S3. Perform the modified nitriding / carbonodriding operation with the following specific parameters:

[0031] The reaction temperature is 540-590℃, the holding time is 1-2.5h, the flow rate of ammonia and nitrogen is 30-50m3 / h, and the flow rate of CO2 is 2-8m3 / h. The reactor used for the nitrocarburizing operation is a square bell-type furnace without a muffle tank.

[0032] S4. Remove the casting body to complete the manufacturing operation of the brake disc body. The nitrogen and carbon compound layer on the surface of the finished product is 6-8um. The loose layer on its surface is discontinuous. 90% of the loose layer is Fe3O4 oxide, and the rest is exposed graphite.

[0033] In summary, the manufacturing method of this special brake disc for new energy electric vehicles results in a finished product with a compound layer thickness of 6-8 μm, which is sufficient to meet the requirements of brake discs for new energy electric vehicles. The loose layers of the finished product of this invention are discontinuous, with 90% being Fe3O4 and the remainder being graphite, while most brake discs in the prior art have continuous loose layers. Therefore, in terms of the coefficient of friction, the finished product of this invention is higher than that of the brake discs in the prior art, resulting in a relatively higher safety factor during use.

[0034] The manufacturing method of this brake disc body for new energy electric vehicles, by modifying the nitrocarburizing operation parameters, can complete the nitrocarburizing operation in only 1-2.5 hours (in the prior art, the nitrocarburizing operation requires 3-7 hours). Due to the shortened time, the deformation after the nitrocarburizing operation is relatively small, resulting in higher precision of the finished product. No additional stress relief process is required, which reduces manufacturing time and improves production efficiency while ensuring the quality of the finished product.

[0035] The manufacturing method of this brake disc for new energy electric vehicles involves a relatively high casting temperature after the nitrocarburizing process, generally 390-380℃ (in the prior art, the casting temperature after the nitrocarburizing process is 135-145℃). If other high-temperature processes are required later, the energy consumed by heating is saved (if no high-temperature processes are required later, it can be cooled naturally, which will incur additional costs; at the same time, heat recovery can be carried out during the cooling process). If there are defective products, due to the relatively high current temperature, remelting and remanufacturing also greatly reduces energy consumption.

[0036] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0037] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for manufacturing a brake disc body specifically for new energy electric vehicles, characterized in that: The specific steps are as follows: S1. Purchase 250mm gray iron brake discs as the casting body for subsequent machining operations; S2. Based on product requirements and the condition of the casting body, perform turning operations on the casting body; S3. Perform the modified nitriding / carbonodriding operation with the following specific parameters: The reaction temperature is 540-590℃, the holding time is 1-2.5h, and the flow rates of ammonia and nitrogen are 30-50m³ / h. 3 CO2 flow rate is 2-8 m³ / h. 3 / h; S4. Remove the casting body to complete the manufacturing operation of the brake disc body; In step S3, the reactor used for the nitrocarburizing operation is a muffle-free square bell furnace; In step S4, the nitrogen-carbon compound layer on the surface of the finished product is 6-8 μm, and the loose layer on its surface is discontinuous. 90% of the loose layer is Fe3O4 oxide, and the rest is exposed graphite. The furnace temperature of the casting body after the nitrocarburizing operation is 390-380℃. During the cooling process, heat energy is recovered. If there are unqualified products, they are recycled due to the relatively high current temperature, thus reducing energy consumption.

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