Injection-hole disc for a valve and method for its manufacture

摘要

A injection-hole disc, having at least one conical spray opening, for a fuel injection valve is already known. In this case, the spray openings are firstly introduced parallel to the longitudinal axis of the valve in the flat injection-hole disc. Plastic deformation of the injection-hole disc then takes place, for example by thermoforming, in the region of the spray openings. By means of this operation, the spray openings which are now inclined towards the longitudinal axis of the valve assume a conical shape. The at least one spray opening (25) is made in the novel injection-hole disc (21) by erosion parallel to the longitudinal axis of the valve. The erosion takes place using the tool electrode (51) while the dielectric (50) located around the tool electrode (51) flushes out the removed particles in the opposite direction to the erosion operation. During this process, the conical spray opening (25) is formed. In order to avoid a compensation of the conicity produced after the injection-hole disc (21) has been pierced by the tool electrode (51), the dielectric (50A) provided on the end face (19) facing away from the tool electrode (51) flows counter to the operating direction of the tool electrode (51) under pressure (p) into the spray opening (25) as a flushing reinforcement. The injection-hole disc is suitable, in particular, for injection valves of fuel injection systems of internal combustion engines (Figure 4). <IMAGE>