Mandrel holds expendable core in casting die

Abstract

This disclosure concerns a casting die for a cylinder, including engine blocks having a plurality of cylinders such as for internal combustion engines, including an expendable core for forming a jacket around the cylinders. This core has a printout portion at one end of the cylinder which is held in place by a cooperating flange on a mandrel that fits inside the cylinder. This mandrel may hold a liner for the cylinder. A dowel is provided in one of the die parts for insertion into the hollow mandrel. The mandrel is held in position by being clamped between the two opposing die parts, and the flanges of the core printout portion may be loosely held in the printout cavity of one of the die parts which preferably also contains one or more locating pins for bridging at least part of the gap between the printout portion and the printout cavity in the die for better positioning the core in the die. The core and mandrel may be assembled outside the die before being placed on the dowel, and after the casting is made, the mandrel and core are removed with it and then separated so the mandrel can be reused. For forming plural cylinders in an engine block, a secondary mandrel frame may be employed for further supporting the separate mandrels for each cylinder and the plural cylinder expendable core by holding the flanged printout portion of the core between the flanges on the separate mandrels and the secondary mandrel frame. In casting the plural cylinders of a V-engine block, retractable dowels permit the employment of die parts and slides that move only at right angles to each other.