Hot-runner plastic injection molding system
First Claim
1. A hot-runner plastic injection molding system comprising a mold which has stationary and movable mold halves, and is provided with a plurality of cavities which is defined when the mold is closed and with a resin passage which communicates the cavities with the nozzle of a plastic injection machine to feed molten resin to each cavity through a gate open thereto, anda heating means for heating the resin passage to keep resin in the resin passage in a molten state, said heating means including a plurality of tubular members,characterized in thatat least part of the resin passage near to each gate is formed by one of said tubular members of material which can be heated by high frequency induction heating, and said heating means comprises a plurality of high frequency induction heating windings which are respectively wound around the tubular members and are connected in series with each other, a high frequency power supplying means for supplying the high frequency induction heating windings with high frequency power, and a temperature control means which controls the power to be supplied to the high frequency induction heating windings from the high frequency power supplying means according to a temperature signal from a temperature detecting means, thereby controlling the temperature of the tubular members to a target temperature.
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Accused Products
Abstract
In a hot-runner plastic injection system, part of a resin passage connecting the nozzle of an injection molding machine and cavities of a mold adjacent to each of the cavities is formed of a tubular member of material which can be heated by high frequency induction heating. High frequency induction heating windings are wound around the tubular members and are connected to a high frequency power source in series with each other. There is provided a temperature controller for controlling the temperature of the tubular members by controlling the power to be supplied to the heating windings.
51 Citations
30 Claims
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1. A hot-runner plastic injection molding system comprising a mold which has stationary and movable mold halves, and is provided with a plurality of cavities which is defined when the mold is closed and with a resin passage which communicates the cavities with the nozzle of a plastic injection machine to feed molten resin to each cavity through a gate open thereto, and
a heating means for heating the resin passage to keep resin in the resin passage in a molten state, said heating means including a plurality of tubular members, characterized in that at least part of the resin passage near to each gate is formed by one of said tubular members of material which can be heated by high frequency induction heating, and said heating means comprises a plurality of high frequency induction heating windings which are respectively wound around the tubular members and are connected in series with each other, a high frequency power supplying means for supplying the high frequency induction heating windings with high frequency power, and a temperature control means which controls the power to be supplied to the high frequency induction heating windings from the high frequency power supplying means according to a temperature signal from a temperature detecting means, thereby controlling the temperature of the tubular members to a target temperature.
Specification