Piston having a barrel of forged steel and a cooling channel

• US 6,026,777 A
• Filed: 01/21/1999
• Issued: 02/22/2000
• Est. Priority Date: 10/07/1998
• Status: Expired due to Term

• Current Assignee: Mahle GmbH (MAHLE-STIFTUNG GmbH)
• Original Assignee: Mahle GmbH (MAHLE-STIFTUNG GmbH)
• Inventors: Ullrich, Michael, Kemnitz, Peter
• Primary Examiner(s): MCMAHON, MARGUERITE J
• Application Number:
  US09/234,750
• Time in Patent Office: 397 Days
• Field of Search: 123/193.6, 92/222, 92/231, 92/260
• US Class Current: 123/193.6
• CPC Class Codes: F02B 23/0696 W-piston bowl, i.e. the combustion space having a central projection pointing towards the cylinder head and the surrounding wall being inclined towards the cylinder wall
• CPC Class Codes: F02F 2200/04 Forging of engine parts
• CPC Class Codes: F02F 3/0023 the parts being bolted or screwed together
• CPC Class Codes: F02F 3/22 the fluid being liquid
• CPC Class Codes: F05C 2201/0448 Steel
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A piston with a cooling channel having a basic piston barrel made from forged steel and a box-shaped shaft, bosses and boss supports and connecting walls between the boss supports as well as a combustion trough. The piston increases the rigidity of the ring part. To accomplish this, the piston has a wall extending all around above the boss bores. A structural component is welded in between the wall and the piston head and limits the cooling channel. This design increases the rigidity of the ring part in pistons.

Claims

1. A piston comprising:

a piston barrel made of forged steel having a carbon equivalent of at least 0.3% and having a box shaped shaft;

a cooling channel formed in the piston barrel;

bosses with boss bores and boss supports formed in the piston barrel;

connecting walls between the boss supports;

a wall extending all around the piston barrel and disposed axially above the boss bores, said wall extending radially outside of the boss supports and the connecting walls, said wall being integrally formed with the basic piston barrel;

an elastic metal sheet in the interior of the piston, said sheet forming a lower limitation of an inner cooling space, said metal sheet being fixed in the region of the boss support by its own initial stress;

a combustion trough formed in the piston barrel; and

a structural component welded to the piston barrel and forming at least part of a ring band and part of a piston head disposed outwardly radially on the piston barrel, wherein the welding seams are produced by a process selected from the group consisting of MIG-welding process, MAG-welding process, laser welding and electron beam welding;

wherein the wall of the piston barrel and the structural component jointly form a radially outer and axially lower limiting wall of the cooling channel, resulting in a bending-resistant zone in the region of the ring band.