The invention relates to a piston for an internal combustion engine having an upper part integrally joined to a lower part having a shaft and at least one pin bore. The upper part including a combustion chamber bowl recess and a piston crown with a crown edge. At least one joint is arranged in the region of a ring zone and in an outer wall of the combustion bowl recess, and the ratio of piston compression height (h.sub.1) and the diameter of the piston (d.sub.1) is less than 0.53.

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 for an internal combustion engine has a surface treatment portion on a piston base material at a piston crown surface, the surface treatment portion including, along the direction of depth from the surface side, a first layer that is comprised of a layer of a first metal or a layer containing the first metal, a second layer that contains both a second metal containing oxygen or an oxide of the second metal and a low-thermal-conductivity material, and a third layer that is comprised of a mixture of a third metal and the low-thermal-conductivity material.

A connecting rod for a variable compression internal combustion engine, the connecting rod including a crank bearing eye configured to connect the connecting rod to a crankshaft of the variable compression internal combustion engine; a connecting rod bearing eye configured to connect the connecting rod to a cylinder piston of the variable compression internal combustion engine; an eccentrical element adjustment arrangement configured to adjust an effective connective rod length, which eccentrical element adjustment arrangement includes an eccentrical element that is connected torque proof with an eccentrical element lever, wherein a wrist pin of the cylinder piston is receivable in the eccentrical element, wherein the eccentrical element adjustment arrangement includes two hydraulic chambers respectively including a piston that is movably arranged in a cylindrical borehole and connected with a support rod which is connected with the eccentrical element lever at another end, wherein the support rod is configured from plural components.

A method for producing a piston for an internal combustion engine may include arranging a piston upper part and a piston lower part in a friction welding device. The piston upper part may include a piston head with a combustion recess. The piston lower part may include two mutually opposite skirt elements connected to one another via two mutually opposite pin bosses. The method may also include arranging a deflecting device configured to deflect at least one weld bead one of on and in the friction welding device. The method may further include joining the piston upper part and the piston lower part to one another via friction welding.

A method for manufacturing a rod includes a step of preparing a hollow first member and a second member formed so as to have a portion smaller in outer diameter than an outer diameter of the first member, a restraining step of placing a restraining member into abutment with an outer peripheral surface of the first member, a step of moving an inner peripheral surface of the first member and an outer peripheral surface of the second member closer to each other while rotating at least one of the first member or the second member, and a step of joining the first member and the second member by welding with the aid of friction by axially pressing in the first member and the second member by a predetermined amount after placing the inner peripheral surface of the first member and the outer peripheral surface of the second member into contact.

Concave part is formed in a crown surface of the top of piston made of an aluminum alloy. This concave part is filled with mixed powder constituted of zirconia powder as a filler material and pure aluminum powder as a bonding material. Solid cylindrical rotary implement is brought into contact with concave part filled with mixed powder, and then pressed against piston under load while being rotated. Mixed powder is softened by frictional heat with rotary implement, whereby mixed powder is bound in a solid phase to concave part to form low thermal conductive part. With this, the bonding strength of low thermal conductive part to the crown surface of the top of the piston is improved.

A laser processing device includes: a laser source; a collimator that collimates light generated by the laser source; an optical element including a converter that converts the collimated light into a beam of light that includes a plurality of collimated lights which respectively have optical axes that are different from each other and that transmits the beam of light; and a focusing element that focuses the beam of light onto a workpiece.

A piston capable of operating at a high temperature and consequently contributing to a high in-cylinder temperature, as well as reducing engine oil temperature, when used in an internal combustion engine, is provided. The piston includes an upper portion and a lower portion welded together to present a cooling gallery therebetween. The cooling gallery extends circumferentially around a center axis of the piston and is spaced the center axis. A partition is located in the cooing gallery and extends from one inner surface to another inner surface of the cooling gallery. The partition extends circumferentially around the center axis, and divides the cooling gallery into at least a first gallery portion and a second gallery portion. The partition can be formed as one piece with the upper portion or the lower portion. Alternatively, the partition can be formed as a separate piece from the upper portion and the lower portion.

The invention relates to a piston of an internal combustion engine including at least one peripheral annular groove. The piston includes an upper part and a lower part permanently joined in the region of a joining plane by a friction welding method. The joining plane may be located between the upper flank and the lower flank of the annular groove. A heat-affected zone is generated due to the use of the friction welding and includes at least one of the upper flank or the lower flank of the annular groove. Where multiple annual grooves are used, the joining plane and heat-affected zone may be positioned on alternate annular grooves.