| 摘要 |
PURPOSE:To manufacture a cylinder head improving thermal fatigue strength by supplying Al to part to be necessary to the excellent thermal fatigue characteristic in the cast Al alloy-made cylinder head raw material and remelting this part. CONSTITUTION:The cylinder head raw material A is produced with low pressure casting method from the Al alloy of JIS standard AC4B, and at the part between an inlet port land an exhaust port 2 to be necessary to the excellent thermal fatigue characteristic and surrounding part of a port 3 for sub- combusting chamber, the pure Al sheet 5 having shape corresponding to these parts is stuck. Successively, after holding the raw material Al at about 250 deg.C for about 1hr, the Al sheet 5 is irradiated with TIG arc 6 as high density energy source from upper part to heat and remelt the part to be necessary to the excellent thermal fatigue characteristic. The raw material A forming the remelting part is water-cooled after holding it at about 535 deg.C for about 4 hr and again heated and held to at about 180 deg.C for 6 hr, and T6 treatment is executed and after executing surface machining with a machine, ASSY is executed, to manufacture the cylinder head. |
