Multipart, Cooled Piston For a Combustion Engine

• US 20080121204A1
• Filed: 11/28/2005
• Published: 05/29/2008
• Est. Priority Date: 11/30/2004
• Status: Active Grant

• Current Assignee: Mahle International GmbH (MAHLE-STIFTUNG GmbH)
• Original Assignee: Mahle International GmbH (MAHLE-STIFTUNG GmbH)
• Inventors: Scharp, Rainer
• Granted Patent: US 7,743,745 B2
• Time in Patent Office: Days
• US Class Current: 123/193.6
• CPC Class Codes: F02F 3/0023 the parts being bolted or screwed together
• CPC Class Codes: F02F 3/22 the fluid being liquid

Abstract

Disclosed is a multipart, cooled piston for a combustion engine, comprising, in a radially outward direction, an annular cooling duct located on the bottom side that faces away from the piston head. The cooling duct is closed by a cooling duct cover which is embodied as a ring. The cooling duct cover is provided with a tongue in the radially inner zone. The tongue engages into a recess that is molded into the bottom piston part, thus preventing the cooling duct cover from rotating relative to the piston during assembly as well as during operation.

Claims

1. Multi-part, cooled piston (1) for an internal combustion engine,

having an upper piston part (2)

that forms the piston crown (30),

that has a ring-shaped cooling channel (10) radially on the outside, on the underside that faces away from the piston crown (30),

that has a ring wall (4) that delimits the cooling channel (10) radially towards the outside, having a ring part (5) on the radial outside of the wall, and

on the underside of which, a pin (19) situated centrally and coaxial to the piston axis (18), having a thread (21), is disposed,

having a cooling channel cover (12) for closing off the cooling channel (10), configured as a ring in the manner of a disk spring, and

having a lower piston part (6)

that has two pin bosses (8) and skirt elements (7) that connected the pin bosses (8) with one another,

that has a region (22) connecting the skirt elements (7) and the pin bosses (8) with one another on the piston crown side, into which region a bore 23 situated centrally and coaxial to the piston axis (18), having an inside thread (24) that fits into the thread (21) of the pin (19), is formed, so that after the cooling channel cover (12) is laid onto a projection (29) formed onto the lower piston part (6) close to the cooling channel (10), the upper piston part (2) and the lower piston part (6) can be screwed together with one another by way of the threaded pin (19) and the threaded bore (23), whereby the radially outer region (12′

) of the cooling channel cover (12) lies on the face surface (26) of the ring wall (4) that faces away from the piston crown, and the radially inner region (12″

) of the cooling channel cover (12) lies on the projection (29), under bias,

wherein

two punched areas (29, 30) directed radially inward are introduced into the radially inner region (12″

) of the cooling channel cover (12), at such a distance from one another that a tongue (25) directed radially inward results between them,

the tongue (25) encloses an acute angle ? with the inner region (12″

) of the cooling channel cover (12),

the projection (29) has a recess (28) radially on the outside, into which the tongue (25) of the cooling channel cover (12) engages when upper piston part (2) and lower piston part (6) are screwed together.

2. Multi-part, cooled piston (1) according to claim 1, wherein the cooling channel cover (12) configured as a one-part and closed ring.