A piston for a heavy duty diesel engine including a composite layer forming at least a portion of a combustion surface is provided. The composite layer has a thickness greater than 500 microns and includes a mixture of components typically used to form brake pads, such as a thermoset resin, an insulating component, strengthening fibers, and an impact toughening additive. According to one example, the thermoset resin is a phenolic resin, the insulating component is a ceramic, the strengthening fibers are graphite, and the impact toughening additive is an aramid pulp of fibrillated chopped synthetic fibers. The composite layer also has a thermal conductivity of 0.8 to 5 W/m.Math.K. The body portion of the piston can include an undercut scroll thread to improve mechanical locking of the composite layer. The piston can also include a ceramic insert between the body portion and the composite layer.

There is provided a method for manufacturing a piston for a vehicle engine, including: a piston assembling step of forming a piston assembly by assembling a first piston part, a bonding member and a second piston part, wherein the first piston part has two or more bonding surfaces separated from each other and extended in a circumferential direction, and the second piston part has two or more bonding surfaces separated from each other and extended in the circumferential direction; a piston diffusion brazing step of diffusion brazing the first piston part, the bonding member and the second piston part under an open atmosphere by heating the formed piston assembly; and a piston cooling step of cooling a piston unit formed by diffusion brazing the first piston part, the bonding member and the second piston part. The piston diffusion brazing step is performed in a piston manufacturing device which includes a partially opened heating zone, a heater for providing heat into the heating zone, and a moving unit moved in one direction in the heating zone. In the piston diffusion brazing step, the piston assembly is heated while being moved at a predetermined speed through the heating zone in one direction by the moving unit.

A piston for an internal combustion engine includes a skirt and a crown coupled to the skirt. The crown is produced in isolation from the skirt using an additive manufacturing process. The piston includes a first air gap between the crown and the skirt. According to an example embodiment, the crown includes a plurality of sections produced in isolation from the skirt. The crown may include a second air gap disposed between two of the plurality of sections.

A method for producing a piston may include producing a piston top part and a piston bottom part each including an inner support element having an inner joining surface and an outer support element having an outer joining surface. At least one of the joining surfaces may include a solder depository. The method may also include pre-machining at least one of the joining surfaces and introducing a high-temperature soldering material in at least one solder depository. The method may further include assembling the piston top part and the piston bottom part to form a piston body via creating at least one of circular contact and linear contact between the joining surfaces such that a gap width is 20 m to 150 m. The method may also include transferring the piston body into a soldering oven, melting the high-temperature soldering material via heating the piston body, and cooling the piston body.

Disclosed is an internal combustion engine piston wherein at least one space is formed into which a coolant is installed. In one example, the coolant is first introduced into a coolant container and the coolant container is thereafter inserted into the at least one space in the piston. In one example, the coolant is an alkali metal consisting of sodium.

A steel piston with anti-coking design features is provided. The piston includes an upper crown portion and a lower crown portion forming an outer cooling gallery therebetween. The outer cooling gallery is substantially closed except for an oil inlet, oil outlet, and optional oil passage(s) to a central cooling gallery. According to one embodiment, at least one anti-coking insert is disposed in the outer cooling gallery and sized to prevent escaping through the oil inlet or the oil outlet. For example, the insert(s) can comprise a helical coil, a plurality of steel balls, coil springs, or chips formed of polymer with abrasive filler. Alternatively, an outer gallery floor to the outer cooling gallery includes a plurality of anti-coking openings disposed sequentially in decreasing spaced relation from one another, or anti-coking openings with varying lengths.

A piston for an internal combustion engine includes: a crown; a skirt extending from the crown; an oil gallery extending annularly within the crown, and having an inlet and an outlet; and a structure mounted at the outlet of the oil gallery to induce oil shaking.

A vehicle internal combustion piston and method of construction thereof are provided. The piston includes piston body extending along a central longitudinal axis, having an upper combustion wall forming an upper combustion surface and an undercrown surface opposite the upper combustion surface. An annular ring belt region depends from the upper combustion surface, a pair of skirt panels depend from the ring belt region, and a pair of pin bosses depend from the undercrown surface to provide laterally spaced pin bores aligned along a pin bore axis for receipt of a wrist pin. The undercrown surface forms a central undercrown region, and a portion of either an open outer cooling gallery, a sealed outer cooling gallery, or an outer galleryless region. A coating including copper is applied to hot spots along the undercrown surface to mitigate the hot spots provide a more uniform temperature along the undercrown surface during operation.

There is provided a method for manufacturing a piston, including: a piston assembling step of forming a piston assembly by assembling a first piston part, a bonding member and a second piston part, wherein the first piston part has two or more bonding surfaces separate from each other and extending in a circumferential direction, and the second piston part has two or more bonding surfaces separate from each other and extending in the circumferential direction; a piston diffusion brazing step of diffusion brazing the first piston part, the bonding member and the second piston part under an open atmosphere by heating the formed piston assembly; and a piston cooling step of cooling a piston unit formed by diffusion brazing the first piston part, the bonding member and the second piston part. The piston diffusion brazing step is performed in a piston manufacturing device which includes a partially opened heating zone, a heater for providing heat into the heating zone, and a moving unit moved in one direction in the heating zone. In the piston diffusion brazing step, the piston assembly is heated while being moved at a predetermined speed through the heating zone in one direction by the moving unit.

A piston includes an upper member having a crown and a combustion surface extending radially inward from the crown. The upper member includes concentrically oriented first and second upper connecting surfaces integrally formed on the bottom side of the upper member. At least one of the upper connecting surfaces includes a curvilinear and/or multi-arcuate cross-sectional profile. The piston also includes a lower member having a pair of opposing skirts, each skirt defining a bore. The lower member also includes concentrically oriented first and second lower connecting surfaces integrally formed on a top side of the lower member. The lower member is integrally connected to the upper member by friction welding. The curvilinear and/or multi-arcuate profile enables a shortened distance between the top surface of the crown and the bore centerline of the bore. Methods of manufacturing the piston are also disclosed.