Clamping Force Setting Rules for Automotive Wheel Mold Assembly

Automotive wheel low-pressure casting molds have strict clamping force setting specifications, which are key parameters to ensure mold closing tightness, casting dimensional precision and mold service life. Wheel casting has high liquid filling pressure and complex cavity structure, and unreasonable clamping force will directly lead to casting flash, dimensional deviation and mold structural damage. Industry unified setting rule takes 1.2 times of the maximum casting working pressure as the core standard. The conventional maximum working pressure of wheel low-pressure casting is 10-12.5MPa, so the matched clamping force is stably set at 12-15MPa. When the clamping force is lower than 10MPa, the mold cannot resist the jacking force of high-pressure aluminum liquid, resulting in local mold gap opening and casting flash defects, which seriously affects wheel appearance and dimensional qualification rate. When the clamping force exceeds 18MPa, excessive extrusion stress will be generated on the mold plate and guide column, causing permanent micro deformation of the mold structure and reducing mold assembly precision. In assembly operation, secondary graded clamping process is adopted: first pre-clamp with 60% of the standard force to correct mold position, then apply full standard force locking, which can effectively improve the uniform stress of the mold, avoid unilateral gap deviation, and further stabilize casting quality. Standardized clamping force setting can control wheel mold assembly fault rate below 1%.