锻件加工扩孔的基本方法有哪些?扩孔的办法大致有冲子扩孔、芯棒扩孔和劈缝扩孔三种。

　　What are the basic methods of forging processing reaming Reaming? Measures are punch reaming, mandrel reaming and split seam hole three.

　　1、冲子扩孔：这种办法是在坯料上用小冲子先冲一孔，再用较大的冲子过一下，可将孔扩展一些，逐渐将孔扩到请求的尺度，多用于孔径在300mm以内的扩孔。

　　1, punch hole: this approach is to punch a hole with small punch in the blank, and then have a large punch, the hole expansion, gradually expanding to the request of the pore scale, used for reaming diameter within 300mm.

　　2、芯棒(马杠)扩孔：首要用于环形件铸造。是将芯棒穿入已冲过孔的坯料，并支撑在马架上，在铸造中边锤击边滚动边送进坯料，使坯料沿圆周在芯棒和上砧间反复遭到锻订被延伸，直到内径到达请求尺度停止。

　　2, mandrel (horse bar) reaming: mainly used for ring casting. Is the blank has crossed the hole through the mandrel, and supported on the trestle, the casting side hammer while rolling edge to the blank, the blank and mandrel along the circumference in the upper anvil forging was repeatedly set was extended, until the diameter scale arrival request stop.

　　3、劈缝扩孔：在坯料上先冲出两个小子孔后，把两孔间的金属剁开，用冲子胀开切断再扩孔，锻件加工以到达锻件请求的尺度。这种办法用于铸造大孔径薄壁锻件或铸造外形是不规则的带孔薄壁锻件。

　　3, crack expanding: first out of the two small holes in the blank, the metal cut between two holes, cut and reaming punch bulging, forging processing to forging scale request. The method is used for casting large aperture thin-wall forgings or casting shapes, and is an irregular thin-walled forging with holes.