Cylinder block and method for manufacturing the same

• Main Author: MICHIOKA HIROFUMI
• Format: Patent
• Language: English
• Published: 28.06.2007
• Subjects: ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES; BLASTING; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; COMBINED OPERATIONS; COMBUSTION ENGINES; CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; DIFFUSION TREATMENT OF METALLIC MATERIAL; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES ORMATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHERTHAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES; INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUSSUBCLASSES OF CLASSES F01-F04; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; LIGHTING; MACHINE TOOLS; MECHANICAL ENGINEERING; METAL-WORKING NOT OTHERWISE PROVIDED FOR; METALLURGY; OTHER WORKING OF METAL; PERFORMING OPERATIONS; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TRANSPORTING; UNIVERSAL MACHINE TOOLS; WEAPONS

A cylinder block has a metal film on an inner circumferential surface of each cylinder. The film is constituted by a first sprayed layer formed on the inner circumferential surface of the cylinder and a second sprayed layer formed on the inner circumferential surface of the first sprayed layer. The hardness of the second sprayed layer is lower than the hardness of the first sprayed layer. It is preferred that the second sprayed layer have a Vickers hardness of 50 to 200. It is preferred that the first sprayed layer have a Vickers hardness of not less than 350. It is preferred that the first sprayed layer have a thickness of 400 mum to 500 mum. A method of manufacturing a cylinder block includes the step of casting a cylinder block, which involves casting the cylinder in the cylinder block, the step of forming the first sprayed layer on the inner circumferential surface of the cylinder, and the step of forming the second sprayed layer on the inner circumferential surface of the first sprayed layer.