用挤压机生产摩托车轻合金车轮，有时会产生“跑边缝”，所谓“跑边缝”就是车轮在铸造过程中，高温液态金属从模具型腔合型面向外飞溅而出，这是一种不正常现象。造成“跑边缝”的直接原因有：模具材料选用不当，模具合型面间隙过大、模具变形、翘边等，间接原因有；压铸时比 The production of motorcycles light alloy wheels with the extruder, sometimes have a “running seam”, the so-called “running seam” is the wheel in the casting process, the high temperature liquid metal splash out from the mold cavity outwards, which is An abnormal phenomenon. The direct cause of “running seam” is: improper selection of mold material, mold fit surface clearance is too large, mold deformation, Alice edge, the indirect causes are; die-casting ratio