Piston for an internal combustion engine and method for its production

• US 20120222644A1
• Filed: 04/18/2011
• Published: 09/06/2012
• Est. Priority Date: 03/04/2011
• Status: Active Grant

• Current Assignee: Mahle International GmbH (MAHLE-STIFTUNG GmbH)
• Original Assignee: Mahle International GmbH (MAHLE-STIFTUNG GmbH)
• Inventors: Bing, Karlheinz, Lapp, Michael T., Scharp, Rainer, Ullrich, Michael
• Granted Patent: US 8,813,712 B2
• Time in Patent Office: Days
• US Class Current: 123/193.6
• CPC Class Codes: B23K 2101/003 Pistons
• CPC Class Codes: B23K 26/28 of curved planar seams
• CPC Class Codes: B23P 15/10 pistons
• CPC Class Codes: F02F 2200/00 Manufacturing
• CPC Class Codes: F02F 3/00 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: Y10T 29/49249 Piston making
• CPC Class Codes: Y10T 29/49252 Multi-element piston making

Abstract

A piston for an internal combustion engine has a piston head, a piston skirt, and a circumferential recess configured between the piston head and the piston skirt. The piston has a piston base body and a piston ring element. The piston base body has a crown region of a combustion bowl and the piston skirt. The piston ring element has a piston crown, a wall region of the combustion bowl, a circumferential top land, and a circumferential ring belt with ring grooves. The piston ring element has a circumferential cooling channel between the wall region of the combustion bowl and the ring belt, closed with a closure element. The piston base body and the piston ring element have a circumferential joining seam in the region of the combustion bowl, by way of which seam they are non-releasably connected with one another.

Claims

1. Piston (10) for an internal combustion engine, having a piston head (10a), a piston skirt (15), and a circumferential recess (25) configured between the piston head (10a) and the piston skirt (15),

wherein

the piston (10) has a piston base body (11) and a piston ring element (12),

the piston base body (11) has at least a crown region (19a) of a combustion bowl (19) as well as the piston skirt (15),

the piston ring element (12) has at least a piston crown (21), a wall region (19b) of the combustion bowl (19), a circumferential top land (22), and a circumferential ring belt (23) provided with ring grooves,

the piston ring element (12) has a circumferential cooling channel (27) between the wall region (19b) of the combustion bowl (19) and the ring belt (23), closed with a closure element (26),

the piston base body (11) and the piston ring element (12) have a circumferential joining seam (28) in the region of the combustion bowl (19), in each instance, by way of which seam they are non-releasably connected with one another.

2. Piston according to claim 1, wherein the joining seam (28) encloses an acute angle (α

) with the center axis (M) of the piston (10).

3. Piston according to claim 1, wherein the closure element (26) is held on the piston ring element (12) in the region of the ring belt (23).

4. Piston according to claim 1, wherein the end (28a) of the joining seam (28) on the cooling channel side lies outside of the cooling channel (27).

5. Piston according to claim 4, wherein the free edge (26a) of the closure element (26) is disposed above the joining seam (28).

6. Piston according to claim 1, wherein the closure element is configured as a one-piece or multi-piece sheet-metal component.

7. Piston according to claim 1, wherein the closure element is configured as a one-piece or multi-piece spring sheet and lies against the piston (10) with its free edge (26a), under bias.

8. Piston according to claim 1, wherein the closure element (26) has at least one entry opening (31) that is provided with a sleeve-shaped guide element (32) for the cooling oil that projects into the cooling channel (27).

9. Method for the production of a piston (10) for an internal combustion engine, having a piston base body (11) and a piston ring element (12) and a ring-shaped recess (25) configured between a piston head (10a) and a piston skirt (15), comprising the following method steps:

(a) making available a blank (11′

) of a piston base body (11) that has at least a crown region (19a) of a combustion bowl (19), the piston skirt (15), as well as a joining surface (33) in the region of the combustion bowl (19);

(b) making available a blank (12′

) of a piston ring element (12) that has at least a piston crown (21), a wall region (19b) of a combustion bowl (19), a circumferential recess (27a), as well as a joining surface (34) in the region of the combustion bowl (19);

(c) connecting the blank (11′

) of the piston base body (11) with the blank (12′

) of the piston ring element (12) by way of their joining surfaces (33, 34), to produce a piston blank (10′

);

(d) reworking and/or finishing the piston blank (10′

) to produce the piston (10).

10. Method according to claim 9, wherein subsequent to step (b) or subsequent to step (c), the recess (27a) is closed by means of a closure element (26), in such a manner that a circumferential cooling channel (27) is formed.

11. Method according to claim 9, wherein subsequent to step (b), the closure element (26) is reversibly or irreversibly attached in the region of the ring belt (23).

12. Method according to claim 9, wherein a blank (11′

) of a piston base body (11) and a blank (12′

) of a piston ring element (12) are used, whose joining surfaces (33, 34) enclose an acute angle (a) with the center axis (M) of the piston (10).

13. Method according to claim 9, wherein the blanks (11′

, 12′

) of piston base body (11) and piston ring element (12) are connected with one another by means of beam welding, particularly laser welding.

14. Method according to claim 9, wherein a blank (11′

) of a piston base body (11) is used, which has at least the crown region (19a) and a part of the wall region (19b) of the combustion bowl (19).

15. Piston (10), which can be produced according to a method according to claim 9.