| 摘要 |
PURPOSE:To ensure the circularity of cylinder bore at all times by fitting a dummy head to a cylinder head, inserting a heating head in the bore for heating a cylinder part and machining the heated cylinder part. CONSTITUTION:A cylinder block 1 is so constituted that a dummy head 2 analogous to a cylinder head is fixed with a tightening bolt, transferred to a heating station via a transfer table 14, a heating head 13 comprising a heating coil 12 wound about the support member 11 thereof is inserted in each bore with a heating device 10 utilizing an induction hardening device and an internal bore wall is heated approximately up to the same temperature as in engine operation. And rough machining, intermediate finishing and horning are carried out under a tightening force and a temperature condition near the case of an actual engine. According to the aforesaid process, both of mechanical deformation due to the tightening of a cylinder head and thermal deformation at the time of engine operation can be properly absorbed and the circularity of a cylinder bore can always be ensured without any complicated machining process. |
