COMPLEX-SHAPED PISTON OIL GALLERIES WITH PISTON CROWNS MADE BY CAST METAL OR POWDER METAL PROCESSES

• US 20170314506A1
• Filed: 05/15/2017
• Published: 11/02/2017
• Est. Priority Date: 02/18/2013
• Status: Abandoned Application

• Current Assignee: Federal-Mogul, LLC (Apollo Global Management, Inc.)
• Original Assignee: Federal-Mogul, LLC (Apollo Global Management, Inc.)
• Inventors: SCHNEIDER, NORBERT G.
• Application Number:
  US15/594,964
• Publication Number:
  US 20170314506A1
• Time in Patent Office: Days
• CPC Class Codes: F02B 23/0681 Square, rectangular or the like profiles
• CPC Class Codes: F02F 3/0015 Multi-part 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: F02F 3/26 having combustion chamber in piston head the surface thereof being covered F02F3/14
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y10T 29/49249 Piston making

Abstract

A steel piston with an oil gallery, and process for forming a steel piston oil gallery channel, which corresponds to the complex shape of the combustion bowl in the piston crown. The piston crown is made by a cast metal or powder metal forming process. The oil gallery channel is formed to the basic shape that corresponds to the shape of the walls of the combustion bowl. Machine-turning surfaces in the oil gallery channel can be machine finished as desired. Surfaces in the oil gallery which cannot be machined with conventional turning operations, such as recesses and protrusions into the channel, are left in the original as-formed condition.

Claims

1. A method of manufacturing a piston, comprising the steps of:

providing a lower member including sidewall portions and pin bores;

providing an upper crown member having a combustion bowl on an upper side thereof and a lower surface on a lower side thereof, wherein the combustion bowl includes a plurality of protrusions spaced from one another along its outer perimeter;

machining the lower surface of the upper crown member; and

joining the upper crown member to the lower crown member.

2. The method of claim 1, wherein the joining step includes welding.

3. The method of claim 1, wherein the machining step includes machining portions of the lower surface located opposite the protrusions.

4. The method of claim 1, wherein the machining step includes machining the lower surface to a shape corresponding to a shape of the combustion bowl.

5. The method of claim 1 including providing the piston with an outer rim surrounding the combustion bowl, a ring belt depending from the outer rim, a cooling gallery disposed radially inwardly of the ring belt, and the machining step includes machining the lower surface until the upper crown member has a substantially uniform thickness along the cooling gallery.

6. The piston of claim 1, wherein the machining step includes machining portions of the lower surface located opposite the protrusions and spaced from one another by as formed portions.

7. The method of claim 1, wherein the machining step includes machine turning.

8. The method of claim 1 including the step of providing the piston with an outer rim surrounding the combustion bowl, a ring belt depending from the outer rim, and a closed cooling gallery disposed radially inwardly of the ring belt;

and wherein

the joining step includes welding;

the machining step includes machining portions of the lower surface located opposite the protrusions, machining the lower surface to a shape being the same as a shape of the combustion bowl, and machining the lower surface until the upper crown member has a substantially uniform thickness along the cooling gallery; and

the machining step includes machine turning.