Piston For Internal Combustion Engines, Produced By Means of a Multi-Orbital Friction Welding Method

• US 20110119914A1
• Filed: 01/30/2009
• Published: 05/26/2011
• Est. Priority Date: 02/29/2008
• Status: Active Grant

• Current Assignee: KS Kolbenschmidt GmbH (Rheinmetall AG)
• Original Assignee: KS Kolbenschmidt GmbH (Rheinmetall AG)
• Inventors: Gniesmer, Volker, Janssen, Michael Albert, Weissert, Martin, Stork, Steffen, Luz, Gerhard
• Granted Patent: US 8,789,273 B2
• Time in Patent Office: Days
• US Class Current: 29/888.04
• CPC Class Codes: B23K 20/12 the heat being generated by friction; Friction welding
• CPC Class Codes: B23K 2101/003 Pistons
• CPC Class Codes: Y10T 29/49249 Piston making
• CPC Class Codes: Y10T 29/49252 Multi-element piston making
• CPC Class Codes: Y10T 29/49256 with assembly or composite article making

Abstract

A method for producing a piston of an internal combustion engine, designed as a one-piece cooling channel piston. The piston includes an upper part and a lower part supported by corresponding circumferential joining bosses together forming a joining zone. In order to produce a bonded joint of the upper part and the lower part, the joining bosses are connected by means of multiorbital friction welding in the region of a rotationally symmetrical or rotationally asymmetrical joining zone.

Claims

1. A method for producing a piston of an internal combustion engine, designed as a one-piece cooling channel piston comprising an upper part and a lower part that are supported by matching joining bosses together forming a joining zone and bonded by means of a friction weld, characterized in that multi-orbital friction welding is carried out to join the joining bosses of the piston that run one of rotationally symmetrically or rotationally asymmetrically.

5. A piston produced by the method in accordance with the method of claim 1, wherein the joining bosses have one of a constant and differently designed wall thickness around a circumference of the bosses.

6. The piston of claim 5 wherein the joining zone disposed circumferentially in the piston has a vertical offset “

v”

.

7. The piston of claim 5, wherein a vertical offset is provided between the two joining zones of the piston located radially offset to each other.

8. The piston of claim 5, wherein the joining bosses are designed to be closed circumferentially.

9. The piston of claim 5 wherein at least one joining boss encloses a passage.

10. The piston of claim 5 wherein at least one joining boss has a stiffening rib facing one of radially inward and radially outward.

11. The piston of claim 5, wherein at least one joining zone running one of rotationally symmetrically and rotationally asymmetrically runs perpendicular to a piston axis.

12. The piston of claim 5, wherein at least one section of the joining boss is aligned in some areas approximately parallel to an axis of the piston.

13. The piston of claim 5, wherein one position of the joining zone deviates from a perpendicular pressure direction resulting from the multi-orbital friction weld.

14. The piston of claim 5, wherein upsetting axes for the multi-orbital friction weld are aligned one of orthogonally and in a position to each other diverging therefrom.

15. The piston of claim 5, wherein the piston includes a combination of an outer cooling channel and an inner cooling channel that are separated by the joining bosses, where at least one joining boss encloses a passage forming a fluid transfer opening.

16. The piston of claim 5, wherein the cooling channel of the piston is at least partially sealed with a separate additional member.

17. The piston of claim 5, wherein the additional member inserted as one of an interference fit a positive fit and a material bond in the piston has at least one passage.

18. The piston of a claim 5, wherein a piston blank, the upper part and the lower part are produced from one of a matching material and from different materials, where one of aluminum and steel is the primary alloying element.

19. The piston of claim 5, wherein the upper part and the lower part made as forged, cast or produced by thixocasting can be used as piston blanks for the piston.

2. A method for producing a piston of an internal combustion engine, designed as a one-piece cooling channel piston comprising an upper part and a lower part that are supported by matching joining bosses together forming a joining zone and bonded by means of a friction weld, characterized in that the piston comprises at least two joining zones (24a, 24b) spaced apart radially from each other and running one of rotationally symmetrically and rotationally asymmetrically whose joining bosses are joined by means of multi-orbital friction welding.

3. The method claim 2 wherein a welding bead resulting after the friction weld is completed is left at the joining zones.

4. The method of claim 2 wherein a cooling channel of the piston is closed during the multi-orbital frictional welding process.