JPS6486473A - Heat emitting structure of electric water boiler - Google Patents

Abstract

PURPOSE:To enhance the operating easiness in winding and enhance the safety, durability, and warm-keeping effect by winding a warm-keeping heater wire at the oversurface round a warm-keeping base board, winding a main heater wire at the undersurface round a heating base board in two-layer close contacting structure, and enclosing the oversurface and undersurface with an upper plate and lower plate, respectively. CONSTITUTION:A heat emitting structure 7 is composed of a warm-keeping heater element 11, which is pinched by a pair of insulating micas 10a between an upper plate 8 and a lower plate 9, which includes a warm-keeping heater wire 11b wound round a warm-keeping base board 11a and which is fixed to a fitting 12, a press plate 13 situated below the warm-keeping heater element 11, and a main heater element 14 which is pinched by another pair of insulating micas 10b and which includes a main heater wire 14b wound round a heating base board 14a. These three members together with associate parts are put one over another to form a laminated structure. Here the press plate 13 is equipped with a thermister 15 and a fuse 16 for control of temperature. Because heating during warm-keeping as a major part of current supply time is carried out with the warm-keeping heater element 11 situated above, air bubbles of the heat emitting structure generated during heating separate easily in the center at the oversurface where it is easy for bubbles to separate, and consequently there is no risk of deterioration of the insulation due to corrosion.