A steel piston with a bushing applied to pin bore surfaces by laser cladding or laser additive manufacturing is provided. The bushing is formed of metal, such as bronze, and metallurgically bonded to the steel of the piston. Thus, the bushing cannot fail by rotating relative to pin bore surfaces. The bushing has a porosity ranging from 0.05% to 5%, based on the total volume of the bushing, and a thickness ranging from 0.07 mm to 6 mm. Since the metal is applied directly to the steel by laser cladding or laser additive manufacturing, the overall size of the piston is reduced, compared to typical pistons with a separate steel backed bushing, and the possibility of bushing rotation is avoided. The bushing also provides scuffing resistance and increased unit load capacity of the pin bore.

A remanufactured piston for an internal combustion engine includes a crown and a skirt. A piston body includes a first piston body end within the crown and an opposite second piston body end. The crown further includes an annular crown body having an annular crown body edge. The first piston body end further includes an annular piston body edge. The annular piston body edge and the annular crown body edge form a joint, and a metallurgical bond attaches the annular crown body to the piston body at the joint.

A ring carrier for a piston for an internal combustion engine is formed by a carrier body having an outer circumferential surface, an inner circumferential surface, a top surface and a bottom surface, with at least one ring groove formed in the outer circumferential surface. An outer circumferential portion of the ring carrier is formed of gray iron, and an inner circumferential portion is formed of ductile iron. A transition region between the outer circumferential portion and the inner circumferential portion intersects upper and lower flanks of the ring groove, so that an outer circumferential extent of the flanks is formed of gray iron and an inner circumferential extent of the flanks is formed of ductile iron.

A steel piston (1) for a combustion engine, having an upper part in which a ring section (7) with at least one ring groove (8) is arranged, wherein the upper part is adjoined by a lower part that has two opposing skirt wall sections (2), wherein the two skirt wall sections (2) are connected via two mutually opposite case walls (3), wherein a pin bore (4) surrounded by a piston boss (6) is provided in each case wall (3). In one example, there is at least one aperture (14) or at least one recess in the case wall (3) in the region between the piston boss (6) and the skirt wall section (2).

A piston, particularly a piston for use in a diesel engine, particularly a heavy duty diesel engine, is formed from a billet of metal, such that the finished piston has a mass that is at least 50%, and, more preferably, up to about 62%, of the mass of the billet. Other than finishing steps, the piston is formed with a closed gallery, without loss of mass through machining processes.

A piston, particularly a piston for use in a diesel engine, particularly a heavy duty diesel engine, is formed from a billet of metal, such that the finished piston has a mass that is at least 50%, and, more preferably, up to about 62%, of the mass of the billet. Other than finishing steps, the piston is formed with a closed gallery, without loss of mass through machining processes.

A manufacturing method for a cylinder device which includes a cylinder, a piston, a piston rod, a seal member, and an installing member, the method includes: a welding step for fixing the installing member to the cylinder through electrical resistance welding; a demagnetizing step for demagnetizing at least an opening portion of the cylinder; and an assembling step for assembling the piston, the piston rod, and the seal member in the cylinder through the opening portion.

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.

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.