JPS638377Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to an electric water heater that boils water using an electric heater, and mainly relates to improvement of an electric circuit that controls the electric heater.

[Prior art]

Conventionally, the electric circuit of an electric water heater was as shown in FIG.

That is, in the figure, 1 is the power supply, 2 is the fuse, and 3
4 is a heat-retaining heater, and 4 is a temperature sensing element A that controls the power supply to the heat-retaining heater 3, and the OFF temperature (t ₁ °C) is 9.
℃, ON temperature (t ₂ ℃) is set to 85℃.
5 is a heater for boiling water; 6 is a temperature sensing element B that controls the electricity supply to the heater 5 for boiling water; the OFF temperature (t ₃ °C)
is set to 95℃, and the ON temperature ( _t4 ℃) is set to 80℃. Further, 7 is a boiling water indicator lamp, 8 is a heat retention indicator lamp, and 7A and 8A are lamp resistors.

The heaters 3 and 5 are located at the bottom of the water container of the electric water heater, and the temperature sensing elements A, B 4 and 6 are located at locations where the temperature of the water in the water container can be accurately detected, such as on the outer wall of the water container. Furthermore, the lamps 7 and 8 are respectively provided in the outer case so as to be visible from the outside.

Next, the operation of this conventional circuit will be explained. That is, when a voltage is applied to this circuit, electricity is applied to the heat-retaining heater 3 and the water-boiling heater 5, respectively, and they generate heat. Then, when the water temperature reaches 90℃ (t ₁ ℃), temperature sensing element A4
OFF, cutting off the power to the heat-retaining heater 3.
When the water temperature further rises to 95° C. (t ₃ ° C.), the temperature sensing element B6 is turned off, cutting off the power supply to the water boiling heater 5. Also, when the water temperature reaches between 80℃ (t ₄ ℃) and 85℃ (t ₂ ℃) due to natural heat dissipation, addition of water, etc., temperature sensing element A4 turns on and the heat retaining heater is turned on. 3, and the water temperature is 85℃~90℃
When the water temperature drops below 80°C (t ₄ °C), the temperature sensing element B6 turns on and energizes the water heater 3, raising the water temperature to 95°C (t ₃ °C).
℃). The conventional method operates as described above.

However, as mentioned above, conventional methods had the disadvantage that the water temperature did not reach 100°C (boiling), so the water was not sterilized.

In addition, the OFF temperature (t ₁ ℃) or (T ₃ ℃) is 100℃
Although the hot water temperature can be raised to 100℃ by using temperature sensing element A4 or temperature sensing element B6, the conventional method did not use a temperature sensing element with an OFF temperature of 100℃ for the following reason .

In other words, if a temperature-sensitive element with an OFF operating temperature exceeding 100°C, such as 101°C, is used in the electrical circuit of a water heater, the temperature-sensitive element will remain OFF for a long time.
Instead, the water continues to boil until the water runs out, resulting in a dangerous situation. For this reason,
When it comes to water heaters, it is necessary to avoid this dangerous situation at all costs, so in order to avoid this dangerous situation and raise the water temperature to 100°C, make sure to turn it off at 100°C.
It is necessary to use a temperature-sensitive element that However, with current manufacturing technology, it is extremely difficult to obtain a temperature-sensitive element that reliably turns off at 100°C, and even if it could be obtained, it would be extremely expensive, so conventional methods prioritize price. (sacrifice boiling at 100℃), and in anticipation of variations in OFF operating temperature accuracy,
It used a temperature-sensitive element with an OFF temperature of 90°C and 95°C.

Moreover, it goes without saying that if 100°C boiling is given priority, the price of the temperature sensing element will be sacrificed.

Also, in order to boil at 100°C, it is also possible to use only a timer without using a temperature sensing element.

In other words, when the water container of an electric water heater is full, it is 20℃.
If the time required for water to boil to 100°C is 20 minutes, one option would be to use a timer and set the timer to operate for 20 minutes from the beginning.

However, with this configuration, for example, if the initial water temperature is 5°C, it will not reach 100°C boiling, and if the initial water temperature is 30°C, the time to boil to 100°C will be too long, resulting in wasted power and It cannot sufficiently cover the difference in water temperature, and also cannot cover the difference in the amount of water in the water container. This results in disadvantages such as waste.

[Summary of the idea]

This invention was made to improve the above-mentioned drawbacks, and includes a timer that starts when electricity is turned on and energizes the water heater for a set time, and a water temperature at a predetermined temperature lower than 100 degrees Celsius (for example, 90 degrees Celsius). A temperature sensing element is provided, which energizes the water heater until then, and when the water temperature exceeds the predetermined temperature, cuts off the power to the water heater and energizes the timer to start the timer, The temperature of the water
The water heater is configured to energize the water heater through the temperature sensing element until the temperature is lower than 100°C, and when the water temperature exceeds the predetermined temperature, the water heater is energized for a set time through the timer. be.

As a result, there is no need for a thermosensor whose operating temperature is extremely accurate, that is, no expensive thermosensor, and while minimizing power consumption,
It is possible to provide an electric water heater that can reliably boil at 100°C.

Furthermore, this invention adds a water amount detection means for detecting the amount of water in the electric water heater to the above configuration, so that the power consumption can be almost completely eliminated and boiling at 100 degrees Celsius can be performed more reliably. The operating time of the timer is set in accordance with the amount of water detected.

[Example of idea]

An embodiment of this invention will be described below with reference to FIGS. 2 and 3.

That is, in FIG. 2, reference numeral 9 denotes a motor timer installed in parallel with the water heater 5, which starts operating when energized and closes its contact 12, and opens its contact 12 when the set time is over.

Reference numeral 10 denotes a temperature sensing element C, and 11 a switching contact thereof, which switches energization to the water heater 5 and the timer 9. Note that the other configurations of this electric circuit are the same as those of the conventional circuit, so explanations thereof will be omitted.

Further, in FIG. 3, 15 is a water amount detection means provided on the outer case of the electric water heater, which detects the amount of water in the water container of the electric water heater so that the amount of water injected into the water container can be seen from the outside. It is composed of a transparent tube 15A that communicates with the water container and is visually visible from the outside and has the same liquid level as the water level, and a scale plate 15B that has a cutout at a portion corresponding to the transparent tube 15A. The scale plate 15B is provided with a scale for displaying the actual amount of water in the water container and a scale corresponding to a timer operation time setting scale 16, which will be described later, through cutouts. In addition, in this example, when the water in the water container is 0.6, the temperature is 1
If the current is applied for 2 minutes from 95°C for 1.2, 3 minutes from 95°C for 1.8, 4 minutes from 95°C for 2.4, and 5 minutes from 95°C for 3, the temperature will rise to 100°C. Since the water heater 5 with a capacity that can obtain boiling water is used, the scale plate 15B
The scale corresponding to the timer operation time setting scale 16 in is the number 1 at the water volume of 0.6, 2 at the water volume of 1.2, 3 at the water volume of 1.8, 4 at the water volume of 2.4, and 5 at the water volume of 3. It is becoming.

Further, 9A is a knob for setting the operation time of the timer 9 described above, and a linear mark is formed on the surface.

16 is formed at a location corresponding to the mark of the knob 9A on the outer case of the electric water heater, and is 0 to 16.
This is a timer operation time setting scale consisting of 5 numbers, and the numbers 1 to 5 correspond to the numbers 1 to 5 on the scale plate. In other words, in this embodiment, since the above-mentioned capacity is used as the water heater 5, the number 1 on the timer operation time setting scale 16 is set to 1 when the mark on the knob 9A is aligned with the number 1. 9 operation time for 1 minute [95℃
The number 2 is formed at a position where it can be set to the time required to heat 0.6 of hot water to 100℃ with the water heater 5, and when the number 2 is pinched and the 9A mark is aligned, the timer 9 operates. 2 minutes [95℃ hot water 1.2 to 100℃ with water heater 5
It is formed in a position that allows it to be set at the desired time.

Also, for numbers 3-5, put knob 9 on the numbers 3-5.
When the mark A is aligned, the operation time of the timer 9 can be set to 3 minutes, 4 minutes, and 5 minutes, respectively.The number 0 is set when the mark 9A of the knob is aligned with the number 0. , is formed at a position where the operating time of the timer 9 is not set.

In addition, if the timer 9 takes into consideration the variation in accuracy of the temperature sensing element C10, the reading error of the scale of numbers 1 to 5 on the scale plate 15B, and the timer operation time setting scale 16, it is assumed that the timer 9 can be used for each water volume for 1 minute. To provide some margin, for example, when the mark on the knob 9A matches the number 5 on the scale 16, the operation may be performed for 6 minutes.

Further, in this embodiment, the temperature sensing element C10 is
OFF temperature t ₅ ℃, ON temperature t ₆ ℃, and temperature sensing element A4
The OFF temperature t ₁ °C and ON temperature t ₂ °C are 95 °C and 80 °C, respectively.
℃, 90℃, and 85℃.

Next, the usage and operation of the electric water heater according to this invention will be explained. First, a predetermined amount of water is poured into the water container of the electric water heater, the amount of water is read by the water amount detection means 15, and the operating time of the timer 9 is set by turning the knob 9A according to the read amount. .

In other words, for example, when the water volume is 1.8, the scale plate 1
The scale of numbers 1 to 5 on 5B can be read as 3, so the mark on knob 9A should also be set to 3 on the timer operation time setting scale 16 to set the timer operation time to 3.
Set to minutes.

At this time, even if you set the operating time of the timer 9 to 4 minutes or 5 minutes when the water temperature is 1.8, boiling at 100°C can be obtained, but when the water is 1.8, boiling water from 95°C for 3 minutes is possible. Boiling at 100°C can be achieved by energizing the water heater 5. Therefore, in consideration of power saving time, it is preferable to set the timer operating time to 3 minutes when the water is 1.8 liters.

When a voltage is applied to the electric circuit, electricity is supplied to the heat-retaining heater 3 and the water-boiling heater 5, and each of the heaters 3 and 5 generates heat. When the water temperature reaches 90℃ (t ₁ ℃), temperature sensing element A4 turns OFF, and heat retention heater 3
When the energization is cut off and the water temperature further rises to 95° C. (t ₅ ° C.), the temperature sensing element C10 is turned off and its switching contact D11 is switched to the timer 9 example. When this switching operation is performed, the timer 9 starts operating and its contact E12 is turned on, and the water heater 5 is energized through the contact E12 of the timer 9. And this timer 9 is
It operates for the time set with knob 9A above (for example, 3 minutes when the water volume is 1.8) and heats the water to 100℃.
After boiling, stop and turn off contact E12.
The power supply to the heater 5 for boiling water is cut off.

Note that the other operations are similar to the conventional one.

In addition, if boiling to 100°C is not required, the timer 9 need not be set; in other words, the mark on the knob 9A should be aligned with the number 0 on the scale 16 for setting the timer operation time, and the amount of water added, When the water temperature drops due to re-boiling, etc. and requires boiling to 100 degrees Celsius, you can set the timer appropriately depending on the amount of water.

FIG. 4 shows another embodiment of this invention, in which the temperature sensing element C10 is connected to the switching contact D1.
1, a relay 13, and a thermostat 14, and the configuration is similar to that of the embodiment described in FIGS. 2 and 3 above, except that the switching contact D11 is operated by the relay 13 and thermostat 14. It's summery.

Then, the OFF temperature of the thermostat 14 is _t5 ℃,
The ON temperature t ₆ °C is the temperature sensing element C1 of the above embodiment, respectively.
Since the temperatures are 95° C. and 80° C. as in 0, the same operation as in the above embodiment is performed. In other words, the water temperature is 95℃
(t ₅ °C), the relay 13 is energized and the water heater 5 is energized through the switching contact D11. When the water temperature exceeds 95 °C (t ₅ °C), the thermostat 14 is turned off and the relay 13 is turned off. The operation is performed to cut off the power supply to the switch, switch the switching contact D11 to the timer 9, and start the timer 9.

In each of the above embodiments, the operating time of the timer 9 is manually set. However, the water level detection means 15 may be a sensor such as a water level detection sensor or a weight sensor to automatically measure the water level. By making it possible to detect the water level and automatically setting the operating time of the timer 9 using the output of sensors such as the water level detection sensor and weight sensor, the timer operating time is automatically set according to the amount of water. It may be set.

[Effect of idea]

As described above, according to this invention, there is a timer that starts when electricity is turned on and energizes the water heater for a set time, and a timer that energizes the water heater until the water temperature reaches a predetermined temperature lower than 100 degrees Celsius. When the temperature exceeds the predetermined temperature, the device is equipped with a temperature sensing element that cuts off the power to the water heater and also powers the timer to start the timer, so it does not require an expensive temperature sensing element. Reliably, without the need for electricity, and while minimizing power waste.
An electric water heater capable of boiling at 100°C can be provided.

Furthermore, according to this invention, a water amount detection means is added to the above-mentioned configuration, and the operating time of the timer is set in accordance with the detection means detected by the water amount detection means, so that the above-mentioned power consumption is completely eliminated. It will be possible to bring the temperature closer to 100°C, and even more reliably achieve boiling at 100°C.

[Brief description of the drawings]

FIG. 1 is a diagram showing an electric circuit of a conventional electric water heater, FIGS. 2 and 3 are diagrams showing an electric water heater according to an embodiment of this invention, and FIG. 2 is a diagram showing the electric circuit. 3 is a perspective view showing its appearance, and FIG. 4 is a diagram showing an electric circuit of an electric water heater according to another embodiment of the invention. In addition, the same symbols in the figures indicate the same or equivalent parts,
5 is a water heater, 9 is a motor timer, 10
is the temperature sensing element C, 11 is the switching contact D of the temperature sensing element C,
15 is a water amount detection means.

Claims (1)

[Scope of utility model registration request] In an electric water heater that boils water with a water heater, there is a timer that starts when electricity is turned on and energizes the water heater for a set time, and a timer that starts the water heater when the water is turned on and energizes the water heater for a set time. A temperature sensing element that turns off electricity to the water heater and starts the timer when the water temperature exceeds the predetermined temperature; What is claimed is: 1. An electric water heater comprising: a water amount detecting means for detecting a water amount, and configured to set an operating time of the timer in accordance with a detected water amount detected by the water amount detecting means.