Taking the lower casing of a car air conditioning compressor as an example. This product uses ADC12 alloy and is produced on a DCC400 die-casting machine. The punch diameter is 70mm, the net weight of the product is 1040g, the slag ladle weight is 267g, the temperature of the automotive die-casting mold is 180-220 ℃, and the temperature of the aluminum liquid is 650-680 ℃.

After several small-scale production, it was found that there were varying amounts of air leaks in several parts of the lower shell produced by automotive die-casting molds, with a comprehensive air leakage rate even reaching 20% to 30%. Although some leaking product parts can meet the customer's inspection standards after subsequent infiltration treatment, the high cost of each infiltration leads to a significant increase in production costs, and the mold cannot be put into normal production. For this reason, calculation and analysis were conducted on several trial production die-casting processes, and the original die-casting process parameters of the automotive die-casting mold were basically adjusted to the Z-best state.

Use the currently popular die-casting simulation flow analysis software to conduct mold flow analysis on the filling process of the automotive die-casting mold.

From the mold flow filling diagram, it can be seen that due to the fact that the gate of the automotive die-casting mold is located on the end face of the product, during the metal liquid filling process, several air leakage areas happen to be where the Z end of the metal liquid filling is located. Due to the thick bottom of the product and the thin circumferential barrel wall thickness, the end of the metal liquid filling cannot be effectively compensated during the pressurization stage after Z, resulting in loose internal structure, which leads to air leakage in the casting, The air tightness is not qualified.

From the above analysis, it can be seen that the gate position design of the automotive die-casting mold is inadequate, resulting in unqualified air tightness testing of the casting. Adjusting process parameters can only slightly improve the proportion of air leakage, and cannot fundamentally solve the problem of casting air leakage.

Therefore, it has been decided to change the gate position of the automotive die-casting mold. At the same time, conduct simulation filling analysis on the new design scheme.

From the simulation analysis after changing the gate position, it can be seen that in the new filling scheme, the metal liquid is basically filled in sequence and flows smoothly. At the same time, there is also a large slag collection bag and a certain area of exhaust groove at the Z end of the metal liquid flow; From the simulation results, it can be seen that the modified scheme is significantly superior to the original design scheme.

Subsequently, based on the new design scheme, we made changes to the gate position of the automotive die-casting mold. After a small batch of mold testing, the comprehensive air leakage rate of the product decreased to around 3.3%, achieving the expected effect.

Beilun Fenda Mold | 16 Automotive Die Casting Mold Manufacturing