A working cylinder has a cylinder tube, a first closure part, a second closure part and a piston unit. The first closure part is arranged on a first cylinder tube end, the second closure part is arranged on a second cylinder tube end to define a cylinder interior. The piston unit defines at least one working chamber in the cylinder interior. The piston unit slides through the first closure part. The first closure part is joined to the cylinder tube by a first peripheral laser ring weld seam and the second closure part is joined to the cylinder tube by a second peripheral laser ring weld seam. The laser ring weld seams each define a fluid-tight sealing plane. A method for producing the working cylinder is provided.

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.

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 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.

A piston for an internal combustion engine and a method for producing a piston are disclosed. The piston includes an upper piston part and a lower piston part that together delimit a circumferential cooling channel for receiving a cooling medium both radially inside and radially outside. The upper piston part and the lower piston part are connected to one another via a radially outer weld connection and a radially inner weld connection. The radially outer weld connection includes a radially outer weld bead that projects radially inwards into the cooling channel for forming a deflection element for the cooling medium received in the cooling channel.

An assembly method of a piston-cylinder group (10), where the piston-cylinder group (10) includes a cylinder (20) at an end of which a head (40) is fixable, provided with seal gaskets (43). The method includes the steps of: mounting the seal gaskets (43) in appropriate seatings in the head (40); coupling the head (40) with the cylinder (20); and a low-temperature welding of the coupling between the head (40) and the cylinder (20).

A thermal coating method for applying a functional layer to a workpiece surface, particularly for applying a running surface coating to a cylinder running surface of a crankcase of an internal-combustion engine, includes the steps of: melting a coating material by use of a melting device, applying coating material droplets to the workpiece surface by use of a gas jet aimed at the workpiece surface, which gas jet blows coating material droplets from a melting location of the melting device onto the workpiece surface, and cooling or rapidly freezing the coating material droplets during their transport from the melting location to the workpiece surface.

In a method for producing a piston, a flat end surface 44a of a rotary tool 44 of a frictional pore sealing device is brought into abutment with the top surface 5a of a low thermal conductivity member 5 cast on the crown surface 2a of an aluminum alloy piston 1, and this rotary tool is pressed against the low thermal conductivity member's side with a load while rotating the rotary tool through an electric motor and a speed reduction mechanism. With this, a frictional heat between the top surface of the low thermal conductivity member and the end surface of the rotary tool causes to form a plastic flow layer 5d on the top surface, thereby sealing an opening portion of a pore 9a on the top surface of the porous member 6.

A piston main body in a piston assembly of a fluid pressure cylinder includes a first piston member and a second piston member including a plate-shaped member. The first piston member and the second piston member are joined in a state overlapping in the axial direction of a piston rod. The second piston member is not provided with a hole that passes through in the plate thickness direction.

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.