Abstract: In a method for producing a valve seat for a cylinder head of an internal combustion engine made of an aluminum metal alloy as the base material, an added material is fused by a laser beam with the base material of the cylinder head at the point at which the valve seat is to be formed. An alloy or a mixture of an aluminum-silicon alloy and nickel as well as at least one additional component is used as added material.

Abstract: An injection nozzle for use in a common-rail system includes a nozzle body with an actuator piston. In the closed condition of the nozzle the nozzle body bears against a seat and upstream of the seat delimits a nozzle chamber communicated with the high-pressure line of the common-rail system. A working chamber of the actuator piston is communicated with the high-pressure line by way of a feed throttle means, the active surface area of the actuator piston being larger than the surface area of the nozzle body which is effective in the nozzle chamber. A return line leads from the working chamber through a return valve. An actuating means is operated by an electrical signal for actuating the valve member of the return valve. The actuating means is a means which displaces the return valve member in analog relationship with the electrical signal so that the return valve forms in the return line a throttle of variable cross-section.