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Spark Plugs Production Process and Technology

Before production, we will use professional high-precision equipment to inspect the raw materials, and then enter the production process. For ceramics, we use isostatic pressing ceramics, which are fired at a high temperature of 1700 degrees Celsius and can withstand a pressure of 120 MPa. The density, strength and insulation properties of ceramics all meet the standard requirements of CBT/7825-2017D. After testing the appearance, density, strength and internal dimensions of the ceramics, we began to use screen printing technology to print the product model and brand on the ceramic body. After dry, the center electrode will be placed into the ceramic . 

There are generally two types of center electrode materials. One is a nickel alloy material, pressurized by a special method, which makes the molecules of nickel and copper are well combined after several degrees of stretching. Therefore, this material can have the advantages of these two elements at the same time, with the high temperature resistance of nickel and the electrical conductivity and heat dissipation of copper. The other is precious metal electrode of iridium or platinum. We use laser welding technology to tightly bond the iridium or platinum to the center electrode. The melting point of this center electrode can reach 2400 degrees Celsius, which has effectively improved the carbon deposition, prolong the life of the spark plug, and enhance the ignition strength. 

Now it enters the powder filling process. We use the self-developed powder filling equipment to press the copper powder and resistance powder into the ceramic in stages. This ensures the stability of the interior of the ceramic. The screw is inserted into the ceramic filled with powder, and after being fired in a high-temperature electric furnace, the screw is compressed and fixed. At this point the ceramic part is assembled. After completion, we will conduct high voltage discharge inspection on all semi-finished products. 

After testing, we will assemble the good products into the iron shells which are quenched from No. 20 steel, and extruded at one time using imported machines. In the process of processing, fully automatic CNC machine tools are used to ensure the stability and accuracy of dimensions. In the thread processing of the shell, a three-wheel imported thread rolling machine is used to ensure the uniform shape of the thread. In the welding of the side electrodes, we use 5 pulse welding machines to ensure the welding quality of the side electrodes, and the side electrodes are all made by our self-researched nickel alloy, which has a longer life. 

The assembly process of the shell and the ceramic part is divided into two types. One is the combination of hot pressing. The high temperature, generated by the instantaneous heating of a large current to make the shell deform and shrink to complete the perfect combination of the shell and the ceramic parts. The other is powder filling and cold sealing assembly, which uses special configured powder filling to make the iron shell and ceramics tightly connected achieving absolute sealing and preventing air leakage. 

The assembled spark plugs will bend their side electrodes, which are all detected by testing equipment. The gap between the center electrode and the side electrode, and the alignment meet the production requirements. Afterwards, the high-voltage electrical inspection of the finished product is carried out to ensure that each finished product has no leakage or air leakage. 

Finally, the automatic packaging equipment is used to package the product under the premise of protecting the product.