A piston for an internal combustion engine includes a piston body having a top surface and having formed therein a combustion bowl surface, a base material of the piston body having a first thermal conductivity, a first layer of metal bonded to the top surface of the piston body, the first layer of metal having a second thermal conductivity that is lower than the first thermal conductivity, and a second layer of metal bonded to the first layer, the second layer of metal having a third thermal conductivity that is higher than the second thermal conductivity.

Systems, devices, and methods for a self-sensing fluid-driven extending actuation device and associated methods where a fluid controller adds fluid into or removes fluid from a coiled device made from sealed flat layers of material; the pressurized fluid expands the internal volume of the layers causing the device to partially un-coil and extend; a resistance measurement circuit measures the length of the extended section and uses it to control the fluid added or removed from the device to achieve a desired length.

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

A joined body is formed by joining end surfaces of two joining members to each other by a friction welding. The joined body includes a hollow portion formed on at least one of the two joining members, the hollow portion being configured to have an opening at the joining face between the two joining members. The joined body also includes an annular groove portion formed on an inner circumferential surface of the hollow portion at a position separated from a joining face in an axial direction.

A cooling channel piston for an internal combustion engine which includes a piston bottom and a piston shaft that are joined thereto of a friction welding process. The piston bottom and the piston shaft jointly form a cooling channel. An annular wall which radially delimits the cooling channel towards the outside is formed by the piston bottom and/or the piston shaft. The annular wall can be sealed by a welding process once the piston bottom and the piston shaft have been joined together.

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 prechamber ignition assembly for an internal combustion engine includes a base attached to a remanufactured prechamber ignition device at a base weld interface. The remanufactured prechamber ignition device includes a new tip formed of a tip material, and a root formed of a root material, with a used body formed of a body material disposed therebetween. The new tip is bonded to the used body at a tip weld interface and the root is bonded to the used body at a root weld interface.

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.

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 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 assembly includes a locking part for maintaining a position at which the first and second piston parts are assembled, and the method further includes a locking part removing step of removing the locking part from the cooled piston unit.

A drive unit of a fluid-actuated linear drive includes a piston rod, an annular drive piston seated coaxially on the piston rod and a buffer sleeve which is likewise seated coaxially on the piston rod. These components are secured to one another by one and the same common welded joint. Furthermore, a method for the manufacture of such a drive unit and a fluid-actuated linear drive equipped with such a drive unit is proposed.