Piston, method of construction, and piston body portions thereof

Patent metadata

Field	Value
Publication number	US-9915223-B2
Application number	US-201615096377-A
Country	US
Kind code	B2
Filing date	Apr 12, 2016
Priority date	Dec 23, 2009
Publication date	Mar 13, 2018
Grant date	Mar 13, 2018

Abstract

A method of constructing a piston, piston formed thereby, and piston body portions are provided. The method includes providing an upper crown portion at least one annular upper rib depending from the upper combustion wall to a free end having a tapered peak. The method further includes providing a lower crown portion having at least one annular lower rib extending to a free end having a tapered peak. Then, moving the upper crown portion and the lower crown portion toward one another and initiating contact between the upper crown portion and the lower crown portion at their respective tapered peaks. Then, continuing moving the upper crown and the lower crown further toward one another after making initial contact at their respective tapered peaks and forming a friction weld joint between the free ends of the at least one upper rib and the at least one lower rib free end.

First claim

What is claimed is:

1. A method of constructing a piston, comprising:
providing an upper crown portion having an upper combustion wall against which combustion forces directly act in the cylinder bore and at least one annular upper rib depending from the upper combustion wall to a free end having a tapered peak;
providing a lower crown portion having at least one annular lower rib extending to a free end having a tapered peak and a pair of pin bosses configured for receipt of a small end of a connecting rod therebetween;
moving the upper crown portion and the lower crown portion toward one another and initiating peak-to-peak contact between the upper crown portion and the lower crown portion at their respective tapered peaks; and
forcing the upper crown and the lower crown further toward one another after making the initial peak-to-peak contact at their respective tapered peaks and while relatively rotating the upper and lower crowns to generate heat through mechanical friction sufficient to plastically displace and fuse the contacting surfaces in the form of a friction weld joint between the free ends of the at least one upper rib and the at least one lower rib free end.

2. The method of claim 1 wherein the at least one annular upper rib is provided in the form of a pair of annular upper ribs depending from the upper combustion wall, one being an upper inner rib extending to a free end having a tapered peak and the other being an upper outer rib extending to a free end having a tapered peak, and wherein the at least one annular lower rib is provided in the form of a pair of annular lower ribs, one being a lower inner rib bounding an inner gallery floor and extending to a free end having a tapered peak and the other being a lower outer rib extending to a free end having a tapered peak;
and during the step of moving the upper crown portion and the lower crown portion relatively toward one another there is initial peak-to-peak contact made between the upper and lower outer ribs at their respective tapered peaks; and
as a result of the relative rotation of the upper and lower crown portions, a friction weld joint is formed commencing at the contacting peaks and progressing radially to achieve a friction weld joint between the upper and lower inner and outer.

3. The method of claim 2 further including providing at least one of the upper and lower crown portions with a central post having a tapered peak at its free end and during the step of moving the upper and lower crown portions toward one another, engaging the tapered peak of the central post with an engaging surface of the respective other of the upper and lower crown members, with the central post and its respective engaging surface being dimensioned relative to said upper and lower inner and outer ribs so as to initially space the tapered peaks of the ribs from one another, and wherein the relative rotation causes commencement of friction welding of the center post before subsequent commencement of friction welding of the inner and outer upper and lower annular ribs maintaining the upper inner rib free end and the lower inner rib free end in spaced relation from one another to form an annular gap therebetween.

Assignees

• Federal Mogul Corp
• Fed Mogul Llc

Inventors

• Ribeiro Carmo

Classifications

• Y10T29/49252

  Multi-element piston making · CPC title

• F16J1/005

  obtained by assembling several pieces · CPC title

• B23K20/129

  specially adapted for particular articles or work · CPC title

• Y10T29/49254

  Utilizing a high energy beam, e.g., laser, electron beam · CPC title

• B23P15/10

  pistons · CPC title