A piston unit of a working cylinder includes a piston and a piston rod. The piston has an axial bore hole formed therein. The piston rod is received in the axial bore hole. The piston rod and the piston are connected by a material-bond by a circumferential laser ring weld seam. The laser ring weld seam defines a pressure medium-tight sealing plane.

A fuel injection valve includes: a coil that is configured to generate a magnetic flux when the coil is energized; a stationary core that is configured to become a passage of the magnetic flux; a movable core that is configured to be attracted to the stationary core when the movable core becomes a passage of the magnetic flux; and a magnetic-flux limiting portion that is displaced from the stationary core in an axial direction while a degree of magnetism of the magnetic-flux limiting portion is lower than a degree of magnetism of the stationary core. A boundary between the stationary core and the magnetic-flux limiting portion is defined as a limiting boundary, and an imaginary extension line, which is formed by extending the limiting boundary toward the movable core, is defined as a boundary extension line. The limiting boundary is tilted relative to the axial direction.

A cylinder head for an internal combustion engine, includes: first and second valves being intake valves or exhaust valves; a first circumferential wall portion defining a first port, the first port being opened and closed by the first valve and communicating with a combustion chamber; and a first overlay welded portion formed on the first circumferential wall portion and serving as a first valve seat on which the first valve is seated.

A piston for a reciprocating piston engine includes a piston body including a piston form and a superalloy overlay cladding and metallurgically bonded with a portion of the piston form. The superalloy overlay includes a first weld layer disposed on the piston form which includes a first plurality of adjoining weld beads. The superalloy overlay further includes a second weld layer disposed on the first weld layer which includes a second plurality of adjoining weld beads.

A piston and method of making the same includes providing a piston lower part defining a piston axis and at least a portion of the upper combustion bowl surface, and assembling a piston upper part to the piston lower part. The piston upper and lower parts cooperate to define at least in part a cooling gallery extending annularly about the piston. The method further includes bringing the piston upper and lower parts together along respective upper and lower mating surfaces and inducing an electric current between the upper and lower mating surfaces while the upper and lower mating surfaces are in contact.

A piston capable of withstanding high temperatures and extreme conditions of a combustion chamber of an internal combustion engine and manufactured with reduced costs is provided. The method of manufacturing the piston includes casting or forging the bulk of the piston as a single-piece with an open cooling gallery from an economical first material, such as steel, cast iron, or aluminum. The method further includes forming a portion of a combustion bowl surface, which is a small area of the piston directly exposed to the combustion chamber, from a second material by additive machining. The second material has a higher thermal conductivity and higher resistance to oxidation, erosion, and oil coking, compared to the first material. The additive machining process is efficient and creates little waste, which further reduces production costs.

A piston for an internal combustion engine includes a lower portion and an upper portion. An upper joining plane is positioned between the upper and lower extending through the outer circumference of the piston. At least one lower joining plane is positioned between the upper and lower portions. A solder gap is defined in the upper and lower joining planes wherein a solder containing iron is inserted to fixedly join the upper and lower portions together. Methods for producing pistons through connection of the lower portion to the upper portion with solder are also disclosed.

A method for producing a piston for an internal combustion engine may include the steps of: producing a first blank corresponding to a piston main body via a deformation process; producing a second blank corresponding to a piston ring part via at least one of a deformation process and a casting process; pre-machining the first blank and the second blank, and finishing a welding surface of the first blank and a welding surface of the second blank via machining; connecting the first blank and the second blank via welding the welding surface of the first blank to the welding surface of the second blank to form a piston body; and performing at least one of a secondary machining process and a finish machining process on the piston body to produce the piston.

The disclosure relates to a method for producing a component, in particular a vehicle component or an engine component, such as a piston of an internal combustion engine. The method comprises forming a first body region, in particular by means of casting or forging. The method includes forming a second body region, which is connected to the first body region, from an aluminium alloy or an iron-based alloy or a copper-based alloy by means of an additive manufacturing method. The second body region is alloyed in such a manner that it has higher thermal stability, higher mechanical strength or higher wear resistance upon tribological stressing than the first body region.

A piston assembly for a two-stroke internal combustion engine includes an upper part joined to a lower part by hybrid induction welding. The upper part includes an upper and lower walls radially spacing inner and outer walls to present an outer cooling gallery therebetween. The lower wall includes first portions extending radially inwardly from the outer wall to the inner wall above the skirt sections and second portions extending radially inwardly from the outer wall to the inner wall above the pin bosses. The first portions extend oblique to the center axis and undulate between the inner and outer walls to reduce the stiffness of the skirt sections. The second portions of the lower wall extend perpendicular to the center axis. Skirt sections of the piston include a lower portion with a greater radial thickness and containing ring grooves.