A piston of an internal combustion engine includes a crown portion; a pair of thrust-side and counter-thrust-side skirt portions; and a pair of apron portions connecting the thrust-side skirt portion with the counter-thrust-side skirt portion. Each of the pair of apron portions includes an upper end wall connected with the crown portion, and a pin boss portion supporting a piston pin. A reverse-surface-side portion of the crown portion is formed with a hollow portion extending along an outer surface of the upper end wall of the apron portion. The upper end wall of the apron portion includes a bending portion between an outside surface of the pin boss portion and a circumferential end of the skirt portion. The bending portion bends in a step-like manner from the outside surface of the pin boss portion toward the circumferential end of the skirt portion.

A piston of an internal combustion engine includes a crown portion; a pair of thrust-side and counter-thrust-side skirt portions; and a pair of apron portions connecting the thrust-side skirt portion with the counter-thrust-side skirt portion. Each of the pair of apron portions includes an upper end wall connected with the crown portion, and a pin boss portion supporting a piston pin. A reverse-surface-side portion of the crown portion is formed with a hollow portion extending along an outer surface of the upper end wall of the apron portion. The upper end wall of the apron portion includes a bending portion between an outside surface of the pin boss portion and a circumferential end of the skirt portion. The bending portion bends in a step-like manner from the outside surface of the pin boss portion toward the circumferential end of the skirt portion.

The present invention relates to a method for producing a piston (1) for an internal combustion engine from a piston upper part (2) and a piston lower part (3).

The method has the following method steps: producing a piston upper part (2) having a piston top (6), at least parts of a ring section (12) and at least part (7) of a cooling channel (8), by forging or casting for example, producing the piston lower part (3) and closing the part (7) of the cooling channel (8) which is arranged in the piston upper part (2) by means of an additive method, finish-machining the piston (1), including the production of at least one annular groove (4) in the ring support (5) for receiving a piston ring.

In this way, it is possible to provide a piston (1) that has a greater strength in its piston upper part (2), which is subjected to high thermal and mechanical loads, than in its piston lower part (3), which is subjected to lower thermal and mechanical loads, and that permits greater freedom of manufacture in respect of the shape of the piston lower part (3).

The invention relates to a method for producing an engine component, in particular a piston for an internal combustion engine, wherein an aluminum alloy is cast in the gravity die casting process and wherein the aluminum alloy has 7 to <14.5 wt % silicon, >1.2 to ≦4 wt % nickel, >3.7 to <10 wt % copper, <1 wt % cobalt, 0.1 to 1.5 wt % magnesium, 0.1 to ≦0.7 wt % iron, 0.1 to ≦0.7 wt % manganese, >0.1 to <0.5 wt % zirconium, ≧0.1 to ≦0.3 wt % vanadium, 0.05 to 0.5 wt % titanium, and 0.004 to ≦0.05 wt % phosphorus as alloying elements and aluminum and unavoidable contaminants as the remainder. The aluminum alloy can optionally comprise beryllium, wherein the calcium content is limited to a low level. The invention further relates to an engine component, in particular a piston for an internal combustion engine, wherein the engine component is composed at least partially of an aluminum alloy, and to the use of an aluminum alloy to produce an engine component, in particular a piston of an internal combustion engine.

A piston for an internal combustion engine may include a ring belt, a groove, and an additional groove. The ring belt may extend along an axial direction. The groove may be arranged on the outer circumference of the ring belt and may be configured to receive an oil scraper ring. The additional groove may be arranged on the outer circumference spaced apart from the groove with respect to the axial direction. The additional groove may include a first groove side axially facing away from the groove and a second groove side axially facing the groove. The first groove side may include an axial step.

An anti-polishing ring includes a ring body defining an axis of revolution, and a radial direction that is perpendicular to the axis of revolution, and a circumferential direction about the axis of revolution. The ring body includes an outer circumferential surface, a bottom surface, a top surface, and an inner circumferential surface. The inner circumferential surface defines an inner diameter, the ring body defines a radial thickness measured from the inner circumferential surface to the outer circumferential surface, and a ratio of the radial thickness to the inner diameter ranges from 0.015 to 0.020.

A piston for an internal combustion engine may include an encircling ring section in a region of a piston crown. The piston may include a convection region, which has at least one cavity containing a heat transfer medium for dissipation of heat from the piston crown to an underside of the piston. The piston may include a heat insulating region, which is arranged between the ring section and the convection region and thermally insulates the ring section.

A nodular graphite cast iron for pistons according to an embodiment contains, in mass %, C: 2.7 to 4.3%, Si: 2.0 to 3.5%, Mn: 0.3 to 0.8%, Mg: 0.02 to 0.10%, Cu: 0.3 to 1.0%, Cr: 0.05 to 0.90%, and Mo: 0.05 to 1.00% with the balance being composed of Fe and inevitable impurities. Then, the C content and the Si content fall within a composition range defined by a line sequentially joining respective points of point A (2.7%, 3.5%), point B (3.2%, 2.0%), point C (4.3%, 2.0%), and point D (3.8%, 3.5%) indicated by (the C content and the Si content) in a graph illustrating the relation between the C content and the Si content.

A nodular graphite cast iron for pistons according to an embodiment contains, in mass %, C: 2.7 to 4.3%, Si: 2.0 to 3.5%, Mn: 0.3 to 0.8%, Mg: 0.02 to 0.10%, Cu: 0.3 to 1.0%, Cr: 0.05 to 0.90%, and Mo: 0.05 to 1.00% with the balance being composed of Fe and inevitable impurities. Then, the C content and the Si content fall within a composition range defined by a line sequentially joining respective points of point A (2.7%, 3.5%), point B (3.2%, 2.0%), point C (4.3%, 2.0%), and point D (3.8%, 3.5%) indicated by (the C content and the Si content) in a graph illustrating the relation between the C content and the Si content.

The present disclosure provides a sealing ring assembly with one or more piston-integrated gap cover features, configured to seal a high-pressure region from a relatively lower pressure region of a piston and cylinder device. The sealing ring assembly may include two rings which each may include one or more ring segments. The one or more gap-cover features, which may be in the form of protrusions in the piston ring groove, may engage with corresponding flat sections of the ring segments. As the sealing ring wears, the gap-cover features may stay engaged with the ring segments, thereby maintaining a seal.