The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 07, 2012
Filed:
Oct. 05, 2005
Anh-tuan Hoang, Tamm, DE;
Martin Maier, Moeglingen, DE;
Guenther Hohl, Stuttgart, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
Conventional devices have a valve needle and a shape memory element which, by the application of a controllable magnetic field, executes a control stroke travel that operates the actuator, and having a coil that excites the magnetic field which is situated in a magnet housing which, at its end face, is bordered with respect to an actuating axis by a front wall in each case, the front walls having a through opening radially within the coil. It is a disadvantage that the magnetic field excited around the coil is conducted unfavorably, so that at most a slight magnetic field develops in the shape memory element. The shape memory element has a magnetic field flowing through it, in the direction of its longitudinal extension, if at all. Since the shape memory element has a high magnetic resistance and is developed to be very long in the axial direction, only a very weak magnetic field can be induced in the shape memory element. In response to the magnetic field that is weak at most, the shape memory element can generate only a very slight lift of the valve needle. In the device according to the present invention, a strong magnetic field is conducted through the shape memory elements, and in this way, a large control stroke travel is achieved. The shape memory element(s) is/are positioned generally only in the through opening(s).