JP2743553B2 - Insulated water heater - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulated water heater that evaporates a liquid contained in a container and keeps it warm.

2. Description of the Related Art In a conventional heat retaining / water heater, after boiling a liquid in a container, a temperature detecting unit turns on and off a heat retaining heater so as to keep the temperature of the liquid constant, thereby keeping the liquid in the container warm.

Problems to be Solved by the Invention In such a conventional heat retaining / water heater, even if it is desired to set the heat retaining temperature to a high temperature close to the boiling point, it is difficult to use the heater at high altitudes due to variations in the temperature detected by the temperature detecting means. Considering a decrease in the boiling point, etc., there is a problem that the temperature can be set only to about 95 ° C.

An object of the present invention is to solve the above-mentioned problem, and an object of the present invention is to provide a water heater that can keep a liquid at a temperature close to the boiling point.

Means for Solving the Problems In order to achieve the above object, the present invention provides a container for containing a liquid, a first heating means for boiling the liquid in the container, and a second means for keeping the liquid in the container warm. Heating means;
First heating means energizing means for controlling energization of the heating means, second heating means energizing means for controlling energizing of the second heating means, and temperature detecting means for detecting the temperature of the liquid in the container And a control means for outputting an ON signal or an OFF signal to the first heating means energizing means or the second heating means energizing means, and after the liquid boils, the control means makes the second heating means energized. Means for outputting an ON signal or an OFF signal to the means for controlling the energization of the second heating means so as to maintain the temperature at the heat retention set temperature set by the temperature detecting means. If the detected temperature does not reach the heat retention set temperature,
The heat retention is performed by resetting the heat retention temperature lower by a predetermined temperature than the temperature detected by the temperature detection means when the predetermined time has elapsed.

According to the present invention, when the temperature detected by the temperature detecting means does not reach the heat retention set temperature even when heating is continued for a predetermined time during the heat retention after the boiling of the liquid, the temperature after the predetermined time elapses. Since the heat retention temperature is set lower than the predetermined temperature by a predetermined temperature, the liquid can be kept at a temperature close to the boiling point even in a place having a different boiling temperature such as a flat ground and a highland.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. As shown in the figure, a container 1 for storing a liquid (in this embodiment, water) is provided on the outer bottom surface of the container 1.
A first heating means 2 for boiling the water inside and a second heating means 3 for keeping the boiling water warm are mounted. The first heating means energizing means 4 for controlling the energization of the first heating means 2 includes a relay contact 4a and a relay coil 4b, and the second heating means energizing means for controlling the energization of the second heating means 3. Reference numeral 5 denotes a bidirectional thyristor.

The temperature detecting means 6 for detecting the water temperature in the container 1 is composed of a thermistor 6a mounted on the outer bottom surface of the container 1 and a temperature measuring unit 6b, and the temperature measuring unit 6b is composed of an 8-bit A / D converter. The temperature near the boiling point is measured with a resolution of about 0.5 ° C., and the data is output to the control means 7. Control means 7
Is a signal to which an output signal of the temperature detecting means 6 is input and an on / off signal is output to the first heating means energizing means 4 or the second heating means energizing means 5. 8 is a commercial power supply.

In the above configuration, the operation will be described. When water is poured into the container 1 and the commercial power supply 8 is applied, the control means 7 outputs an ON signal to the relay coil 4b and closes the relay contact 4a. Thereby, the first heating means 2 generates heat and heats the water in the container 1. If the water boils, the temperature rise gradient of the thermistor 6a changes to a gentle gradient. Boiling detection is performed by the change in this gradient, an off signal is output to the relay coil 4b, and the relay contact 4a is opened. The heat generation of the heating means 2 is stopped. Then, the control means 7 turns on and off the bidirectional thyristor 5 so that the temperature of the thermistor 6a becomes a preset temperature, for example, 96 ° C., to keep the hot water in the container 1 warm. The heat retention temperature of the hot water at this time is 98 ° C.

By the way, if the heat retention temperature is set to a temperature close to the boiling point of 98 ° C., the former is not hot water due to a decrease in the boiling point of water when the place to be used is at high altitude, or a variation in the adjustment of the heat retention set temperature. Despite boiling, the temperature does not reach 98 ° C. (96 ° C. for the thermistor 6a), and in the latter case, boiling continues beyond 98 ° C., so that any temperature control cannot be performed.

According to the present invention, even if the control means 7 outputs an ON signal to the bidirectional thyristor 5 and energizes the second heating means 3 for a predetermined time, the present invention addresses the thermistor 6a as described above. If the temperature does not reach 96 ° C., or if the control means 7 continues to output an ON signal to the bidirectional thyristor 5 as in the latter case described above, the temperature detecting device 6 It is determined that the water temperature has reached the boiling point, and the heat retention temperature is reset to a predetermined temperature, for example, 2 ° C. lower than the heat retention set temperature of the thermistor 6a by design. By resetting the heat retention temperature, the heat retention temperature is a temperature lower than the boiling point by a predetermined temperature, for example, if the predetermined temperature is 2 ° C., the boiling point becomes 95%
In high places such as ° C, the temperature is 93 ° C, and the heat retention temperature can be set to a temperature close to the boiling point.

As described above, according to the heat retaining / hot water heater of the embodiment of the present invention, when the temperature detected by the temperature detecting means does not reach the heat retaining set temperature even when the power is continued for a predetermined time during the heat retaining,
Since the heat retention temperature is reset by a predetermined temperature lower than the temperature detected by the temperature detection means when the predetermined time has elapsed, the temperature of the hot water can be maintained at a temperature close to the boiling point.

As is clear from the above description of the embodiment, according to the present invention, if the temperature detected by the temperature detecting means does not reach the heat retention set temperature even after a predetermined time has elapsed during the heat retention, the heat retention temperature is reduced. Since the resetting is performed, the heat retention temperature is corrected according to the boiling point, and it is possible to provide a water heater that can keep the heat retention temperature close to the boiling point even in a place with a low boiling point, such as high altitude. .

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view of a heat retaining / water heater according to one embodiment of the present invention, and FIG. 2 is a circuit diagram thereof. DESCRIPTION OF SYMBOLS 1 ... container, 2 ... 1st heating means, 3 ... 2nd heating means, 4 ... 1st heating means energizing means, 5 ... 2nd heating means energizing means, 6 ... Temperature detection Means 7, Control means.

Claims (1)

(57) [Claims] 1. A container for accommodating a liquid, a first heating unit for boiling the liquid in the container, a second heating unit for keeping the liquid in the container warm, and an energization control of the first heating unit. A first heating unit energizing unit that performs energization control; a second heating unit energizing unit that performs energization control of the second heating unit; a temperature detecting unit that detects a temperature of a liquid in the container;
Control means for outputting an ON signal or an OFF signal to the heating means energizing means or the second heating means energizing means, and after the liquid boils, the control means sends an ON signal or an ON signal to the second heating means energizing means. Output an off signal to the second
When the temperature of the temperature detected by the temperature detecting means does not reach the set temperature even when the energization is continued for a predetermined time at the time of keeping the temperature maintained at the set temperature maintained by the temperature detecting means by controlling the energization of the heating means. A water heater that also resets the heat retention temperature by a predetermined temperature lower than the temperature detected by the temperature detection means when the predetermined time has elapsed, and keeps the temperature.