A piezo injector for direct fuel injection may comprise an injector body, an actuator unit having a piezoelectric actuator with a head plate and a base plate, a hydraulic coupler having a coupler piston, a coupler cylinder, and a coupler spring, and a nozzle unit having a nozzle needle arranged in a nozzle body. The piezoelectric actuator is surrounded by a corrugated tube braced between the head plate and the base plate such that the piezoelectric actuator has a preload imparted to it. The coupler spring forces the coupler piston against a face side, facing toward the coupler piston, of the nozzle needle.

A valve assembly for an injection valve may include a valve body including a central longitudinal axis, the valve body having a cavity with a fluid inlet portion and a fluid outlet portion, and a chamber, with an electro-magnetic actuator unit arranged in the chamber, and a valve needle axially movable in the cavity, the valve needle preventing a fluid flow through the fluid outlet portion in a closing position and releasing the fluid flow through the fluid outlet portion in further positions. The valve needle is designed to be actuated by the electro-magnetic actuator unit. A bellows arranged between the valve body and the valve needle is sealingly coupled to the valve body and to the valve needle. The bellows prevents a fluid flow between the cavity and the chamber. An injection valve comprising such a valve assembly is also disclosed.