초록 ▼

In a fuel injector, in particular a fuel injector for fuel-injection systems of internal combustion engines, a piezoelectric or magnetostrictive actuator is surrounded by a compensation sleeve. The compensation sleeve is made of a material exhibiting virtually no, or negative, thermal expansion, so

In a fuel injector, in particular a fuel injector for fuel-injection systems of internal combustion engines, a piezoelectric or magnetostrictive actuator is surrounded by a compensation sleeve. The compensation sleeve is made of a material exhibiting virtually no, or negative, thermal expansion, so that the thermal expansion of the compensation sleeve and that of an upper valve-body section and/or lower valve-body section essentially corresponds to the thermal expansion of the actuator and effective transmission elements to the valve-sealing seat. The compensation sleeve, radially on the outside, is enclosed by a spring sleeve, which connects the lower valve-body section to the upper valve-body section and prestresses the compensation sleeve for pressure.

대표청구항 ▼

What is claimed is: 1. 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 ac

What is claimed is: 1. 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. 2. The fuel injector according to claim 1, further comprising: a thread joining the tube spring to the lower valve-body section; and a flange at which the tube spring wraps around the upper valve-body section. 3. The fuel injector according to claim 1, wherein the tube spring is composed of Invar. 4. The fuel injector according to claim 1, wherein the compensation sleeve is composed of Invar. 5. The fuel injector according to claim 1, wherein the compensation sleeve has the shape of a cylinder with face-ground end faces.