Impeller for supercharger and method of manufacturing the same

A method of manufacturing an impeller for a supercharger by die casting, which impeller comprises a disk-shaped hub extending radially of a center axle, a plurality of blades extending from the hub and consisting of full blades and splitter blades arranged alternately and in adjacent relationship, each of which blades has an aerodynamically curved surface, spaces defined by the blades forming undercuts extending radially of the center axle,

• wherein the process of die casting comprises the steps of:
• forming a cavity by bringing a plurality of slide dies, which are arranged radially in relation to the axis of the impeller to be formed, into close contact with one another to form the impeller, each of the slide dies, having a hub cavity defining portion, blade cavity defining portions, and a bottomed groove portion in the form of a splitter blade thereby having a spatial configuration between a pair of adjacent full blades;
• casting a molten metal into the cavity;
• and
• moving and releasing the slide dies radially of the formed center axle while rotating each of the slide dies around its rotational axis,
• whereby the impeller is obtained, which has a respective space defined by a pair of adjacent full blades comprises parting-line corresponding parts only on a trailing edge face, a fillet face, and a leading edge face, which form an outer periphery of the full blade, the parting-line corresponding parts having forms corresponding to parting-lines each formed among respective adjacent sliding dies brought into close contact with one another when casting.

An impeller for a supercharger, comprising

• a center axle;
• a disk-shaped hub extending radially of the center axle;
• a plurality of blades extending from the hub, consisting of full blades and splitter blades arranged alternately and in adjacent relationship to each other, each of said blades having an aerodynamically curved surface;
• and
• a plurality of spaces defined by pairs of adjacent full blades, and
• wherein parting-lines are only present on a trailing edge face, a fillet face, and a leading edge face, which form an outer periphery of each of the full blades, and parting-lines are not present on a surface of the hub between adjacent full blades.

A method of manufacturing an impeller for a supercharger, by die casting, wherein said impeller comprises a disk-shaped hub extending radially of a center axle, a plurality of blades extending from the hub and consisting of full blades and splitter blades arranged alternately and in adjacent relationship, each of said blades having an aerodynamically curved surface, and spaces defined by the blades forming undercuts extending radially of the center axle, comprising:

• arranging a plurality of slide dies, each of said slide dies comprising a hub cavity defining portion, blade cavity defining portions, and a bottomed groove portion in the form of a splitter blade;
• casting a molten metal;
• and
• moving and releasing said slide dies radially of the center axle while rotating said slide dies, wherein parting-lines are not present on a surface of the hub between adjacent full blades.

An impeller for a supercharger, cast in dies and comprising:

• a center axle:
• a disk-shaped hub extending radially of the center axle;
• and
• a plurality of blades extending from the hub and consisting of full blades and splitter blades arranged alternately and in adjacent relationship, each of which blades has an aerodynamically curved surface, spaces defined by the blades forming undercuts extending radially of the center axle,
• wherein respective spaces defined by pairs of adjacent full blades comprise parting-line corresponding parts only on a trailing edge face, a fillet face, and a leading edge face which form an outer periphery of the full blade, wherein parting-line corresponding parts have forms corresponding to parting-lines each formed among respective adjacent dies brought into close contact with one another when casting, the dies being slide dies each having a hub cavity defining portion, blade cavity defining portions, and a bottomed groove portion.