Patent ID: 7032833

Claim:
A fuel injector for a fuel-injection system of an internal combustion engine comprising: a valve-seat surface; a valve-closure member cooperating with the valve-seat surface to form a valve-sealing seat; a valve needle connected to the valve-closure member; an actuator for actuating the valve needle and the valve-closure member, the actuator being one of piezoelectric and magnetostrictive; an upper valve-body section; a lower valve-body section; effective transmission elements; a compensation sleeve surrounding the actuator, the compensation sleeve being composed of a material having substantially no, or negative, thermal expansion, so that a thermal expansion of the compensation sleeve and of at least one of the upper valve-body section and the lower valve-body section substantially corresponds to a thermal expansion of the actuator and the effective transmission elements to the valve-sealing seat; and a spring sleeve enclosing the compensation sleeve radially on an outside, the spring sleeve connecting the lower valve-body section to the upper valve-body section and prestressing the compensation sleeve for pressure; wherein the spring sleeve includes a tube spring.