JP2011010938A - Electric water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric water heater which reduces boiling time as much as possible.SOLUTION: The electric water heater has a heating means 2 for heating a vessel 1 for containing a liquid, a temperature sensing and boiling control means 4 for sensing boiling by sensing a temperature rise gradient of a temperature sensing means 3 for sensing a liquid temperature in the vessel 1, a reboiling switch 5 for reboiling the hot water kept warm, a floating means 6 to be afloat on a hot water surface in the vessel 1, a displacement sensing means 7 for sensing the displacement of the floating means 6, a displacement sensing and boiling control means 8 for deciding boiling when the displacement sensing means 7 senses a displacement of the floating means 6. When the hot water is heated by the reboiling switch 5, the displacement sensing and boiling control means 8 senses boiling. The position of the floating means 6 afloat on the hot water surface varies when the water gets into a boiling condition and the hot water surface boils hot, the displacement sensing means 7 can quickly sense boiling and stops heating by sensing the shaking of the floating means 6. Consequently, the electric water heater can reduce the boiling time and save power consumption required for reboiling.

Description

  The present invention relates to an electric water heater that heats and keeps a liquid contained in a container, and more particularly to a reboiling water heater of an electric water heater.

  Conventionally, in this type of electric water heater boiling determination, the control means detects the amount of water by the temperature rise of the temperature detection means for detecting the temperature of the liquid in the container, and the temperature rise time exceeds a predetermined value corresponding to the amount of water. If it becomes, it will be judged that it is boiling (for example, refer patent document 1).

JP 2002-10920 A

  However, in the configuration of the above-described conventional electric water heater, both the boiling detection control method at the time of boiling from water and the boiling from the heat retaining state by the reboiling switch is the temperature rise gradient of the temperature detection means installed at the bottom of the container Is used to detect boiling. Therefore, at the time of re-boiling from the heat retention, the temperature rise rate of the hot water is fast, so that the temperature detection by the temperature detection means is delayed from the temperature rise of the hot water.

  On the other hand, when re-boiling hot water that has been boiled once, the descaling has been done to some extent, and since it is kept warm at high temperatures, it can be safely consumed. Such electricity bills are useless, and there is a demand for shortening the boiling time from when steam begins to be emitted until the heating is stopped as much as possible.

  On the other hand, at the time of re-boiling, the boiling time may be short, but there is a boiling demand to always boil water until it is boiled. Conventionally, in order to shorten the boiling time, there has been proposed a steam sensor provided with a steam sensor for detecting steam generated at the time of boiling, but depending on the distance between the steam sensor and the hot water surface, the boiling point has not been reached. However, the steam sensor reacts to the slightly generated steam to stop heating too quickly.

  The present invention solves the above-mentioned conventional problems, and provides an electric water heater capable of boiling and heating until the hot water is boiled and shortening the boiling time when boiling with a reboiling switch from the time of keeping warm. The purpose is to do.

In order to solve the above-mentioned conventional problems, an electric water heater of the present invention includes a container for storing a liquid, a heating means for heating the container, a temperature detection means for detecting the temperature of the liquid in the container, and the temperature detection. Temperature detection boiling control means for detecting boiling by detecting a temperature rise gradient of the means, a reboiling switch for reboiling hot water being kept warm, a float means floating on the surface of the hot water in the container, and the float means A displacement detection means for detecting the displacement of the float means, and a displacement detection boiling control means for determining that the boiling is detected when the displacement detection means detects a displacement of the float means, and the boiling detection means for the displacement detection when boiling by the reboiling switch. The boiling position of the float floats on the surface of the vessel when it is boiled and the surface of the hot water in the container is boiled. Since the heating is detected quickly boiling by detecting can be stopped, it is possible to shorten the boiling time, it is possible to suppress the power consumption required for re-boiling kettle.

  The electric water heater of the present invention can reliably detect the boiling state when the reboiling switch is operated at the time of heat retention, and can shorten the boiling time as much as possible, thereby suppressing the power consumption required for reboiling water boiling. .

Configuration diagram of electric water heater in Embodiment 1 of the present invention Top view of the float means of the electric water heater Flow chart showing the operation of the electric water heater

  According to a first aspect of the present invention, a container for containing a liquid, a heating means for heating the container, a temperature detection means for detecting the temperature of the liquid in the container, and a temperature rising gradient of the temperature detection means are detected to boil. Temperature detection boiling control means for detecting, re-boiling switch for re-boiling hot water being kept warm, float means floating on the surface of the hot water in the container, displacement detection means for detecting displacement of the float means, When the displacement detection means detects displacement of the float means, it comprises a displacement detection boiling control means for determining boiling, and when boiling water by the reboiling switch, the displacement detection boiling control means detects boiling, When the boiling surface of the container is boiled and the boiling surface is boiled, the position of the float that floats on the surface changes, and the displacement detection means detects the fluctuation of the float and quickly detects boiling and stops heating. It is possible to, it is possible to shorten the boiling time, it is possible to suppress the power consumption required for re-boiling kettle.

  In the second invention, in particular, the float means of the first invention has a disk shape, and a plurality of permanent magnets are arranged along the entire outer periphery of the float means. Even if the means rotates, the displacement detecting means can reliably detect the displacement of the float means.

  The third aspect of the invention is particularly over the entire outer circumference of the float means so that the distance between the outer circumference of the float means of the first or second invention and the inner wall of the container is substantially the same at any position. A plurality of protruding spacers are installed, and the distance between the permanent magnet inside the float means and the displacement detection means is always constant, so the detection response of the displacement detection means and signal level fluctuations are stable and stable detection is possible. It becomes.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
The electric water heater in the 1st Embodiment of this invention is demonstrated using FIGS. FIG. 1 is a configuration diagram of an electric water heater in the present embodiment, and FIG. 2 is a plan view of the float means of the electric water heater.

  In FIG. 1, a container 1 of an electric water heater in the present embodiment is a container for boiling water and keeping warm. 2 is a heating means composed of a 910 W heater (not shown) that heats and heats the liquid in the container 1 and a 75 W heat insulation heater (not shown) that has a heating power smaller than that of the heater. is there.

Reference numeral 3 denotes a thermistor that detects the temperature of the liquid in the container 1, and is a temperature detection means that contacts the bottom surface of the container 1. Based on the temperature detected by the temperature detection means 3, the temperature detection boiling control means 4 measures a time ΔT during which the temperature rises by about 5 ° C. during boiling, and when the temperature rise time is detected as five times as long as ΔT, It performs control to detect.

  The reboil switch 5 is a switch operated by the user to perform reboil. When the user operates the reboiling switch 5, the heating means 2 is immediately driven to perform boiling. Denoted at 8 is a displacement detection boiling control means for detecting a fluctuation of the float means 6 floating on the hot water surface in the container 1 as a displacement and judging boiling based on the signal.

  The float means 6 has a disk shape as shown in FIG. 2, and a plurality of permanent magnets 6a are integrally formed at equal intervals along the outer periphery of the float means 6, and the amount of hot water in the container 1 is always changed. It comes to float on the hot water surface. In addition, a plurality of protruding spacers 6b are installed on the outer periphery of the float means 6 at equal intervals. As a result, the float means 6 can be regulated so as to be always located at the center in the container 1, so that the distance between the permanent magnet 6 a and the outer wall of the container 1 is always kept constant.

  The displacement detection means 7 comes into contact with the outer wall of the container 1 from the outside, and the amount of hot water in the container 1 is 0.6L of the water supply level, 1L, 1.5L, 2.0L, 2.5L, and the full water level. In this structure, six reed switches 7a are arranged so as to match the height of the molten metal surface at 3L. The hot water surface during boiling does not fluctuate until it boils, and when it reaches the boiling point, large fluctuations occur due to convection of the hot water or bubbles generated vigorously from the bottom of the container 1.

  When the liquid in the container 1 boils and the molten metal surface fluctuates, the float means 6 vibrates up and down, and in response to the permanent magnet 6a inside the float means 6, the contact of the reed switch 7a is repeatedly turned on and off. The displacement detection means 7 converts the on / off of the reed switch 7 a into a voltage signal and outputs it to the displacement detection boiling control means 8. Since the distance between the permanent magnet 6a and the reed switch 7a is always constant even if the float means 6 rotates, the reaction of the reed switch 7a is always kept at a constant level.

  The operation of the electric water heater in the present embodiment configured as described above will be described with reference to FIG. FIG. 3 is a flowchart showing the operation of detecting boiling water from the temperature of the electric water heater in the present embodiment.

  First, during the heat insulation, it is determined in step S100 whether or not the reboiling switch 5 has been operated. When the reboiling switch 5 is on, the displacement detecting means 7 detects the position information of the float means 6 in step S101. Determine whether or not. If the float means 6 is not detected, it is considered that the user has forgotten to put the float means 6 in, so a warning notification of no float is given in step S102. Then, the reception of the reboiling switch 5 is invalidated, and the reception of the reboiling switch 5 in step S101 is waited again.

  If the float means 6 is detected in step S101, the displacement detection boiling control means 8 turns on the heating means 2 and starts heating in step S103.

  Next, the displacement detection means 7 detects the displacement of the float means 6 in step S104. If a displacement signal due to turning on / off of the reed switch 7a per 3 seconds is detected five or more times, it is determined that the boiling has occurred, and heating of the heating means 2 is stopped in step S105.

According to the conventional electric water heater, in the case of boiling detection by the temperature detection means 3 installed at the bottom of the container 1, the boiling point at the time of re-boiling from 90 ° C. heat retention of about 0.6 L of a small amount of water whose response of detection is most delayed. After the steam is generated, the time until the heating means 2 stops is about 60 seconds. Even in the method of directly detecting steam, the hot water cannot be sufficiently boiled unless about 10 seconds have elapsed since the generation of steam. However, in this embodiment, since it is detected by fluctuation of the hot water surface that the hot water is boiled directly, even in a state where sufficient steam is not generated outside the body of the electric water heater, it can be quickly detected that it is boiling, Heating power consumption required for reboiling can be reduced.

  In the present embodiment, the displacement signal of the float means 6 is used for boiling detection at the time of re-boiling, but the power consumed for heating is the same even if it is used for boiling detection in boiling water other than re-boiling. Can be reduced. In addition, the float means 6 is not only used for detecting fluctuations in the molten metal surface, but if activated carbon or the like is incorporated inside, the water purification effect such as removal of chalk is enhanced, and the range of reasons for using the float means 6 is widened for the user. Therefore, usability will be further improved.

  As described above, according to the present embodiment, when the displacement detecting means 7 detects the displacement of the float means 6 that floats directly on the hot water surface in the container 1, the hot water surface in the container 1 can be boiled by boiling. Since the position of the float means 6 floating on the hot water surface fluctuates and the displacement detection means 7 can quickly detect the fluctuation of the float means 6, heating can be stopped after reliably detecting the determination of boiling. The electric power consumed for re-boiling heating can be reliably suppressed.

  As described above, since the electric water heater according to the present invention can shorten the boiling time at the time of re-boiling, it can also be applied to uses such as a heated extractor for beverages.

DESCRIPTION OF SYMBOLS 1 Container 2 Heating means 3 Temperature detection means 4 Temperature detection boiling control means 5 Reboiling switch 6 Float means 6a Permanent magnet 7 Displacement detection means 7a Reed switch 8 Displacement detection boiling control means

Claims (3)

A container for containing a liquid; a heating means for heating the container; a temperature detection means for detecting the temperature of the liquid in the container; and a temperature detection boiling control for detecting boiling by detecting a temperature rise gradient of the temperature detection means. Means, a re-boiling switch for re-boiling hot water being kept warm, a float means floating on the surface of the hot water in the container, a displacement detection means for detecting displacement of the float means, and the displacement detection means is the float An electric water heater comprising displacement detection boiling control means for detecting boiling when detecting the displacement of the means, and detecting boiling by the displacement detection boiling control means when boiling by the reboiling switch. The electric water heater according to claim 1, wherein the float means has a disk shape, and a plurality of permanent magnets are arranged along the entire outer periphery of the float means. 3. The projecting spacer according to claim 1, wherein a plurality of projecting spacers are provided over the entire outer periphery of the float means so that the distance between the outer periphery of the float means and the inner wall of the container is substantially the same at any position. Electric water heater.

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