| 摘要 |
PURPOSE:To enable mass production by installing a masking member on a piston stock and, after masking a part which is to be the projectingly sliding part of a skirt part, spraying a liquid containing a specific powder onto said piston stock to scrape off a non-masking part. CONSTITUTION:A low friction piston 1 consists of a head part 2 and a skirt part 3. Three projectingly sliding parts 4-6 are provided on the thrust part and opposite thrust part of the skirt part 3. In other words, two of the projectingly sliding parts 4-6 are placed on the shoulder part 7 of the skirt part 3 while one on the lower part of the skirt part 3, in a triangular form. In manufacturing this piston 1, first, masking members 11, 12 are installed on the upper and lower parts, i.e., on the head part 2 and skirt part 3 of the piston stock 10. Then, a liquid containing hard ceramic powder is sprayed from a nozzle 13 at a pump discharge pressure of approx. 3-15kg/cm<2> to scrape off the non-masking part of the piston stock 10 by a depth of 20-30mum. |
