METHOD FOR PRODUCING PISTON FOR INTERNAL-COMBUSTION ENGINE

• US 20090071001A1
• Filed: 09/11/2008
• Published: 03/19/2009
• Est. Priority Date: 09/18/2007
• Status: Active Grant

• Current Assignee: Art Metal Manufacturing Co., Ltd. (Aisin Corp.), Riken Forge Co. Ltd. (Toyota Motor Corporation)
• Original Assignee: Art Metal Manufacturing Co., Ltd. (Aisin Corp.), Riken Forge Co. Ltd. (Toyota Motor Corporation)
• Inventors: KOMATSU, Takaaki, TANAKA, Osamu, KANAI, Shoji, KONDOH, Atsushi
• Granted Patent: US 8,240,039 B2
• Time in Patent Office: Days
• US Class Current: 29/888.40
• CPC Class Codes: B21K 1/185 with cooling channels
• CPC Class Codes: B23P 15/10 pistons
• CPC Class Codes: F02F 3/003 the parts being connected by casting, brazing, welding or clamping
• CPC Class Codes: F02F 3/22 the fluid being liquid
• CPC Class Codes: F16J 1/09 with means for guiding fluids F16J1/08 takes precedence
• CPC Class Codes: Y10T 29/49249 Piston making
• CPC Class Codes: Y10T 29/4925 Repairing, converting, servicing or salvaging
• CPC Class Codes: Y10T 29/49252 Multi-element piston making
• CPC Class Codes: Y10T 29/49256 with assembly or composite article making
• CPC Class Codes: Y10T 29/49265 Ring groove forming or finishing

Abstract

A method is provided for producing a piston for an internal-combustion engine of the structure in which a piston body which is composed of a crown having a groove for fitting a piston ring into an outer circumference surface and a skirt in connection with the bottom of the crown is provided with an annular cavity for flowing cooling liquid on an inside of the groove, the method comprising the steps of: forming the crown and the skirt individually; forming an annular groove for the annular cavity in the inner bottom of the crown and an annular rib in connection with the open edge of the annular groove before the crown and the skirt are joined together; bending the rib toward the opening of the annular groove by application of pressure to close the opening of the annular groove to thereby form the annular cavity; and joining the crown and the skirt together.

Claims

1. A method for producing a piston for an internal-combustion engine of a structure in which a piston body which is composed of a crown having a groove for fitting a piston ring into an outer circumference surface and a skirt in connection with the bottom of the crown is provided with an annular cavity for flowing cooling liquid on an inside of the groove, the method comprising the steps of:

forming the crown and the skirt individually;

forming an annular groove for the annular cavity in the inner bottom of the crown and an annular rib in connection with the open edge of the annular groove before the crown and the skirt are joined together;

bending the rib toward the opening of the annular groove by application of pressure to close the opening of the annular groove to thereby form the annular cavity; and

joining the crown and the skirt together.

2. The method for producing a piston for an internal-combustion engine according to claim 1, wherein the rib is bent toward the opening of the annular groove by pressing a pressure roller for imparting a bending load to the rib.

3. A method for producing a piston for an internal-combustion engine of a structure in which a piston body which is composed of a crown having a groove for fitting a piston ring into an outer circumference surface and a skirt in connection with the bottom of the crown is provided with an annular cavity for flowing cooling liquid on an inside of the groove, the method comprising the steps of:

forming the crown and the skirt individually;

forming an annular groove for the annular cavity in the inner bottom of the crown and an annular rib in connection with the outer open edge of the annular groove before the crown and the skirt are joined together;

joining the crown and the skirt together; and

forming the annular cavity by pressing the rib inwardly so as to bring the tip of the rib into close contact with the upper outer circumference of the skirt.