Processing Cylinder Head is a complex and delicate project that requires the cooperation of multiple processes.
1. Casting process
Casting is the first step in processing Cylinder Head. There are two common methods: sand casting and precision casting. Sand casting is a traditional casting method. By making a sand mold, the molten metal liquid is injected into it, and the Cylinder Head blank is obtained after cooling and solidification. This method is low-cost and suitable for large-scale production, but the precision is relatively low. For example, when making the Cylinder Head of a large engine, sand casting can quickly produce blanks. Precision casting, such as investment casting, can produce Cylinder Heads with high precision and complex shapes. First, make a wax mold, then apply refractory material on the surface of the wax mold, and after drying and hardening, melt the wax mold and discharge it to form a cavity. After injecting molten metal and cooling, the finished product is obtained. This method is suitable for the production of high-end engine Cylinder Heads with extremely high precision requirements.
2. Machining process
Machining is a key step to improve the precision and surface quality of Cylinder Head. Milling is one of the important methods. Milling machines are used to perform plane and contour processing on the Cylinder Head. By cutting the blank with a high-speed rotating tool, various planes and curved surfaces can be accurately processed to ensure the dimensional accuracy and surface flatness of the Cylinder Head. For example, the installation plane of the Cylinder Head is milled to ensure a close fit with the engine block. Turning is mainly used to process the cylindrical surface and holes of the Cylinder Head, such as the valve guide hole. Through the rotation of the workpiece and the feed movement of the tool, high-precision cylindrical surface processing is achieved to ensure the installation accuracy and sealing of the valve. Drilling is used to process various bolt holes, oil holes, etc., and the position accuracy and dimensional accuracy of the holes need to be strictly controlled to ensure the accuracy of subsequent assembly.
3. Special processing technology
In some specific cases, special processing technology is required to meet the special requirements of the Cylinder Head. Electrospark machining is a commonly used special processing method, which is suitable for processing holes and cavities with complex shapes. The high temperature generated by the electric spark discharge between the electrode and the workpiece is used to melt and vaporize the metal material, thereby achieving high-precision processing. For example, when processing some small cooling channels or oil channels of special shapes, electric spark processing can play a unique advantage. Laser processing is also gradually applied to the processing of cylinder heads. It can perform high-precision cutting, punching and engraving operations. Laser processing has fast speed, high precision and small heat-affected zone. For some parts with extremely high requirements for precision and surface quality, such as the nozzle mounting hole, laser processing can provide excellent processing results.
4. Surface treatment process
In order to improve the wear resistance, corrosion resistance and sealing of the cylinder head, surface treatment is required. Common surface treatment methods include spraying and electroplating. Spraying can form a wear-resistant and corrosion-resistant coating on the surface of the cylinder head, such as ceramic coating, to increase the service life of the cylinder head. Electroplating is to increase the surface hardness and corrosion resistance by plating a layer of metal, such as chromium, nickel, etc. on the surface of the cylinder head. At the same time, surface treatment can also improve the appearance of the Cylinder Head and improve the overall quality of the product. In short, processing the Cylinder Head requires the comprehensive use of multiple processes, and the processes must cooperate with each other to produce high-quality Cylinder Head products.
