Process for manufacturing a magnetic circuit for a valve

A method for manufacturing a magnetic circuit for a valve having a longitudinal valve axis, the valve including an internal field and a valve jacket, the internal field and the valve jacket positioned substantially concentric with the longitudinal valve axis, the method comprising the steps of:

• (a) forming a single-part valve housing having a magnetic property, the single-part valve housing having an external contour substantially corresponding to a predetermined contour of the internal field and the valve jacket;
• (b) mounting an intermediate ring on the single-part valve housing, the intermediate ring including an intermediate ring material;
• (c) placing the single-part valve housing in a pressing tool to form a free-space opening, the valve housing including a valve housing material;
• (d) applying a force to the intermediate ring using the pressing tool, the force at least partially displacing the intermediate ring material and the valve housing material radially in the direction of the longitudinal valve axis, the intermediate ring material and the valve housing material being displaced into the free-space opening for binding the intermediate ring material with the valve housing material;
• and
• (e) radially-widening an internal opening in the valve housing up to the intermediate ring using a machining operation, the internal opening being radially-widened for separating the internal field from the valve jacket and for forming the external contour of the valve housing.