dorsal valve是什么意思

用法例句

The process character of back shell bracket of mobile phone is analyzed, and both the structure and working process of injection mold of back shell bracket of mobile phone are introduced, as well as the special inner side core-drawing mechanism and slanting rejecting mechanism are stated.

分析了手机背壳支架的工艺特点,介绍了手机背壳支架注射模具的结构及工作过程,阐述了颇具特色的内侧抽芯机构及斜顶机构。