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AssigneeFederal-Mogul Corporation
InventorsBruce Inwood, Jeffrey L. Riffe
Estimating the term…
A piston including an abradable coating applied to a round surface of the piston is provided. The shape of the round surface is not greater than 0.1 mm from a circular shape, and thus is relatively inexpensive to machine. As the piston reciprocates in an internal combustion engine, the abradable coating rubs against another component, such as a cylinder liner or wrist pin, to achieve suitable contact geometry, such as an oval, asymmetric, or other non-round shape. Thus, a costly machining process is not required to achieve the desired contact geometry. The abradable coating can also be applied to ring lands, skirt sections, or along pin bores of the piston. The abradable coating can also be applied to a wrist pin or an opening of a connecting rod which receives the wrist pin. The abradable coating can be formed from a polymer-based material or an aluminum-silicon alloy-based material.
A piston for use in an internal combustion engine, comprising:
A piston assembly for use in an internal combustion engine, comprising:
A method of manufacturing a piston for use in an internal combustion engine, comprising the steps of:
A method of manufacturing a piston assembly for use in an internal combustion engine, comprising the steps of:
A piston for use in an internal combustion engine, comprising:
Dependencies are inferred from the claim text.
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From the US filing history. Foreign family members aren’t listed.
Pistons: having surface coverings
Running-in of internal-combustion engines
With connecting-rods, i.e. pivotal connections: with gudgeon-pin; Gudgeon-pins
With assembly or composite article making: by coating or cladding
About 9 years 6 months of term left · ends 26 Apr 2036 (estimated)
1. Field of the Invention
This invention relates generally to pistons for internal combustion engines, and methods of manufacturing the same.
2. Related Art
Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
FIG. 1 is a side view of a diesel piston formed of steel and including a cooling gallery and an abradable coating, according to an exemplary embodiment;
FIG. 1a is an enlarged view of a portion of the piston of FIG. 1 showing the abradable coating applied to ring lands;
One aspect of the invention provides a piston 20 with an abradable coating 22 for an internal combustion engine, as shown in the Figures. During use of the piston 20 in the internal combustion engine, the abradable coating 22 rubs against another component, such as a cylinder liner or wrist pin, and wears down to a suitable shape. The abradable coating 22 can be applied to a round running surface of the piston 20 and then wears down to generate an appropriate contact geometry, for example an oval, asymmetric, or other non-circular shape, during the “running-in phase” of operation. Thus, extensive and costly machining of the piston to achieve the appropriate contact geometry is no longer required. In addition to reducing manufacturing costs by reducing the amount of machining, the abradable coating 22 also has the potential to reduce oil consumption, blow-by, emission output, noise, cylinder liner cavitation, and the number of rings from three to two.
The abradable coating 22 can be applied to many types of pistons, for example diesel, gasoline, ethanol, 2-stroke, and 4-stroke pistons, including pistons with or without a cooling gallery. FIGS. 1-5 illustrate an exemplary diesel piston 20 formed of steel and including a cooling gallery 24, FIGS. 6-8 illustrate an exemplary diesel piston 20 formed of steel without a cooling gallery, and FIGS. 9 and 10 illustrate an exemplary gasoline piston 20 formed of aluminum without a cooling gallery. Although not shown, another example of the type of piston to which the abradable coating 22 can be applied is a diesel piston formed of aluminum, with or without a cooling gallery.
In the exemplary embodiments, the piston 20 includes a body portion 26 formed of a metal material. The metal material is typically an iron-based material or an aluminum-based material, but other materials could be used. The body portion 26 extends around a center axis A and longitudinally along the center axis A from an upper end 28 to a lower end 30. The piston 20 also includes a crown 32 extending circumferentially about the center axis A from the upper end 28 toward the lower end 30. In the embodiment of FIGS. 1-5, the crown 32 is joined to the remainder of the body portion 26, in this case by welding.