Injection valve

#The invention relates to an injection valve for internal combustion engines, with a filter element arranged on the inside of the injection valve in the fuel flow of the latter and having ducts for the fuel.

#Patent literature (WO 93/02284, EP 0472 417 A1, U.S. Pat. Nos. 5,050,569, 5,758,826 or 5,179,927) discloses a series of injection valves of this type which are also provided for the heating of fuel prior to injection into the combustion space of internal combustion engines. However, all the approaches used here for heating the fuel are distinguished by a comparatively large mass to be preheated. They therefore all have a high energy consumption and a long response time >60 s.

#An object of the invention is to develop an injection valve and a method, by means of which, particularly when the engine is cold, improved mixture formation and as small a fraction as possible of CH in the exhaust gas during the starting phase can be achieved.

#FIG. 1 shows a detail of a cross section through an injection valve constructed according to a preferred embodiment of the present invention;

#FIG. 2 shows the start of a structurally etched filter element for use with the invention with an aspect ratio greater than 10:1;

#FIG. 3 shows an enlargement of a filter element for use with the invention; and

#FIG. 1 illustrates a detail of an injection valve 1 in cross section, the detail showing the discharge-side end region of the injection valve 1. The injection valve 1 has a housing 2, into which an insert 6 is pushed on the discharge side.

#The insert 6 has a seal 4 on its casing. A frustoconical outflow orifice 5 for the fuel is introduced into the insert 6 on the discharge-side end face. Arranged on the opposite (inflow-side) end face is a valve seat, on which a valve needle 9 of the injection valve 1 can be laid in a seal-forming fashion.

#Furthermore, the remaining surface of the inflow-side end face of the insert 6 is shaped in such a way that it has a termination with as low a flow resistance as possible for the fuel inflow duct 8 arranged concentrically around the valve needle 9.