一、问题的提出: 我厂是一机部生产洗选设备的定点厂。今年接到焦化设备66型气封炉门的制造任务。其铸件技术要求高,难度大,关键件炉门框上有两只Φ20、L1000的不通孔,采用钻加工,要 First, the question put forward: I plant is a machine-designated washing plant production plant. This year received Coking Equipment 66-type gas seal door manufacturing tasks. The casting technology requires high difficulty, the key pieces of the door frame has two Φ20, L1000 not through hole, the use of drilling, to