Method of molding cavity plate of ink jet printer head

Abstract

A cavity plate of an ink jet printer head is adapted to be attached to a piezoelectric element member and has walls prescribing a plurality of ink storing chambers and a plurality of ink discharge holes. A mold for molding the cavity is provided with: a corniform block member including (i) a plurality of corniform convex portions to mold the ink storing chambers, each having an opening portion on a side of an attachment surface of the cavity plate to be attached to the piezoelectric element member, and (ii) a plurality of corniform concave portions to mold partition walls of the cavity plate for partitioning each of the ink storing chambers; and plurality of pin members to mold the ink discharge holes, which are continuous to the ink storing chambers such that the ink discharge holes have straight tubular portions respectively from the ink storing chambers to ink discharge tip portions at an ink discharge surface of the cavity plate on an opposite side of the attachment surface. The pin members include U-shaped column portions, to mold connection portions between the ink storing chambers and the straight tubular portions, respectively. Each of the U-shaped column portions has (i) a half-cylindrical portion and (ii) a prism portion. The pin members also include cylindrical portions to mold the straight tubular portions respectively.