JPS5977815A - Electric pot - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION In the present invention, a liquid is stored in a container equipped with a heater, and this liquid is heated by the heater! This invention relates to a heat-retaining type electric water heater that boils the water continuously and then keeps it warm, with improved temperature control characteristics when boiling the water.

Conventionally, this type of electric water heater has a band-shaped main heater 2 and an auxiliary heater for external use at the bottom of a bottomed cylindrical container 1 made of a stainless steel plate or the like, as shown in FIGS. 4 and 6. A temperature regulator 4 is provided on the outer peripheral surface of the container 1 above the heaters 2 and 3 and is electrically connected in series with the main heater 2. The auxiliary heater 3 is electrically connected in parallel to form an electric circuit. When water 6 is placed in the container 1 and electricity is started, heating is started by the main heater 2 and the auxiliary heater 3 to boil water. As water boiling progresses and water 6 reaches a predetermined temperature, temperature regulator 4 is activated to cut off power to main heater 2 and water boiling is completed. Thereafter, the water temperature is maintained and kept warm by heating only with the auxiliary heater 3. However, the temperature of the water 6 at the end of this boiling process is limited to about 96°C (not guaranteed to boil).

This is because the change in temperature rise when boiling water due to continuous energization of the main and auxiliary heaters 2 and 3 is as follows. For example, the temperature rise changes at the approximate center of the water 6 contained in the container 1, 5a, and at the temperature sensing portion 4a of the container 1, which is the mounting portion of the temperature regulator 4, were as shown in FIG. In other words, the temperature sensing part 4 at time A when water 6+L starts boiling.
Since the temperature of a becomes B''C, if the operating temperature of the temperature regulator 4 is set to a temperature at which the temperature sensing part 4a becomes B'C, the water 6 will boil.However, in reality, the temperature sensing part 4a will boil. The temperature of the portion 4IL hardly rises above B'C, and furthermore, due to variations in the operating temperature in the temperature regulator 4, variations in temperature sensitivity, etc., the temperature regulator 4 does not operate, and the water 5 Most boiled continuously.

Next, assuming that the temperature regulator 4 is provided on the bottom back surface of the container 1, and looking at the temperature change of the temperature sensing part 4b, the sixth
As shown in the figure, the temperature of the temperature sensing portion 4b at time A when the water 5a starts boiling is 87°C.

However, the temperature of the temperature sensing portion 4b hardly rose above B'°C, and the same result as in the previous case was obtained. In other words, when the water 6 boils, the temperature at the lower outer periphery of the container 1 does not rise above 100° C., so in most cases, the temperature remains stable at the temperature at the start of boiling. Therefore, even if a temperature regulator is provided, it is impossible to operate it after boiling, and the operating temperature of the temperature regulator 4 is set within a range that does not boil, taking into account the above-mentioned variations. The hot water obtained from the water heater is
No sterilization or deodorization due to boiling, making milk for babies,
In addition, it was not possible to properly brew coffee and tea.

The present invention solves the drawbacks of conventional heat-retaining electric water heaters by boiling water for a certain period of time and then keeping it at a predetermined temperature upon completion of boiling water.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 11 is a cylindrical container with a bottom made of stainless steel plate, and a recess 12 is provided approximately in the center of the bottom surface of the container.
It communicates with the inside of the container 11, and is provided with a main temperature regulator 13 with its back surface serving as a temperature sensing section. A main heater 1 in the form of a band is wrapped around an insulating plate made of mica or the like and made of seven seams with an aluminum plate or the like on the outer periphery of the lower part of the container 11.
4 and an auxiliary heater 16 are integrally installed.

In addition, in the part off the center of the bottom back surface of the container 11,
An auxiliary temperature regulator 16 and an overtemperature rise prevention device 17 are pressed by a pressing spring 19 attached to a mounting bracket 18. The main heater 14 is electrically connected in series with the main temperature regulator 13, and the auxiliary heater 16 is electrically connected with the auxiliary temperature regulator 16 in series, and these series connections are electrically connected in parallel. 17 to the power supply, in which case each temperature regulator 13.16 is connected to each ° heater 1.
4. Perform the energization control in 15.

The upper end of the container 11 is provided with a flange portion 2o extending in the outer circumferential direction, and a spout 22 is combined with this flange portion 20 via a container backing 21.
is placed on a cylindrical body 23 made of a steel plate or the like that covers the outer peripheral surface of the container 11.

Reference numeral 24 denotes an inner lid that is detachably placed on the container backing 21 located in the nozzle portion 20 of the container 110, and a ball valve 26 for preventing liquid from flowing out in the event of a fall is housed in the center of the inner lid. A valve seat 26 with through holes 27 & 27b is located on the bottom surface. Reference numeral 28 denotes a lid detachably pivoted to the spout 22, and approximately in the center thereof, a through hole 271L of the inner lid 24 is inserted through the lid backing 29.
A lock lever 3 is provided at the open end of the lid 28 to lock and release the lid 28 to the spout 22 via a built-in compression spring 31.
I am wearing 2.

Reference numeral 33 denotes a communication pipe that connects a discharge port 34 and a discharge port 36 provided on a part of the bottom surface of the container 11 via an on-off control valve 36, and the on-off control valve 36 is connected to a lever 3 provided with a return spring 37.
The water filling knob 39 is pressed to open the water injection knob 39 via 8.

Incidentally, reference numeral 4o denotes a fixing metal fitting welded to the bottom back surface of the container 11, and the mounting metal fitting 18 and the supporting metal fitting 41 are screwed thereto. Dimension 42 is the frame, and 43 is the back plate.

In the above configuration, when water 46 is poured into the container 11 and the power is turned on, water is heated by the main heater 14 and the auxiliary heater 16 to boil water.

Here, the main heater 14 and the auxiliary heater 15 are connected to the container 1.
Inside the container 11, the water heated by the heaters 14 and 15 moves upwards by convection, so the temperature near the water surface becomes higher than the temperature at the bottom, but due to the convection of the water. , the gradient of temperature rise over time changes almost the same. However, the water in the recess 12
The convection effect is hindered because the opening is slightly narrowed, and the temperature rise there becomes flat much later than at the top and bottom. FIG. 3 shows temperature changes in the water 45a in the approximately central portion and the water 45b in the recess 12. After the water has boiled to a certain extent, it will begin to boil near the water surface.
As this boiling range gradually decreases, the stirring of the water 45 in the container due to boiling becomes more intense, and finally the 46 kl of water in the four parts 12 is also stirred, and its temperature rapidly rises to reach the boiling temperature. At about the same time, the temperature of the temperature sensing portion 13a on the back surface of the recess 12 also rises rapidly.

Here, the temperature of the temperature sensing portion 13a at the 0 point where the water 4f5& in the substantially central portion starts boiling is, for example, 76°C. Now, if the longest boiling time of the water 46 is set to a range from C to E, where the temperature of the temperature sensing part 13a is not stable, and that time is, for example, 60 seconds, the temperature F of the temperature sensing part 131L at point E is, for example, It will be 90'C. In other words, the operating temperature of the main temperature regulator 13 is approximately 76°C at the temperature sensing section 13a.
If the temperature is set within a range of 90° C. to 90° C., the water 46 contained in the container 11 will boil and the main temperature regulator 13 will operate within 60 seconds to complete boiling.

In addition, the auxiliary temperature regulator 16 cuts off the power supply to the auxiliary heater 16.
The operating temperature is set to a temperature that does not boil when keeping warm.
When boiling water, it operates before boiling.

Next, when the temperature of the water 46 falls to a predetermined temperature, the auxiliary temperature regulator 16 is activated to close the electric circuit, and power supply to the auxiliary heater 15 is started again. This auxiliary heater 16
Heating using water 46 requires far less electricity than boiling water, but as this heating progresses and the temperature of water 46 rises to a predetermined temperature, the auxiliary temperature regulator 16 is activated again and the auxiliary heater 16 is activated.
By repeating this process, the water 46 is kept at a constant temperature. Note that the operating temperature range of the auxiliary temperature regulator 16 is narrower than that of the main temperature regulator 13, so
Before the auxiliary temperature regulator 16 is closed and heating is performed by the auxiliary heater 16, the main temperature regulator 13 is closed and heating is not performed by the main heater 14, so that the above-mentioned boiling operation is repeated during heat retention. There isn't. However, when the water filling knob 39 is pressed to discharge more than a certain amount of water 45 from the discharge port 36 and the water is supplied again, the water temperature of the water 46 becomes lower than the circuit closing operating temperature of the main temperature regulator 13 and the auxiliary temperature regulator 16, and the above-mentioned boiling point occurs again. After repeating the operation, it is kept warm.

In the above description, the water 46 is almost full, but even if the water is small, the boiling time is short, and although the boiling time is slightly longer, the water 46 is kept warm after boiling for a certain period of time.

Further, in this embodiment, the cylindrical recess 12 is provided with a round hole-shaped opening 12a smaller than the maximum diameter of the recess 12, but the shape of the recess 12 and the opening 122L is not limited to a circular shape. Even if the opening area of the opening 121L is the shape of the recess 1
It goes without saying that it is sufficient to have a smaller area than the maximum plane area of 2. Furthermore, although this recess 12 is provided approximately at the center of the bottom of the container 11, this recess 12 is
This prevents the convection action that occurs when the water 46 inside the container 11 is boiled to delay the temperature rise of the water 46 above the recess 12, and then produces a rapid temperature rise due to the stirring action caused by boiling. The same effect can also be expected by providing an opening that projects above the bottom surface of the container 11 and is slightly narrowed on the top surface.

As described above, the present invention generates a rapid temperature rise in the temperature sensing part of the main temperature regulator by the convection action when heating the liquid in the container and the stirring action when it boils, and this temperature rise causes the main temperature to rise. This system absorbs variations in the operating temperature and temperature sensitivity of the temperature regulator and controls the boiling time to a constant level.It is possible with a simple configuration and does not require any other control means such as conventional timers or electronic control circuits. It has great practical value.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of an electric water heater according to an embodiment of the present invention, Fig. 2 is an electric circuit diagram of the electric water heater, and Fig. 3 is a water temperature of the electric water heater and temperature sensing of the main temperature controller. Figure 4 is a partially cutaway side view of a conventional electric water heater, Figure 5 is an electrical circuit diagram of the electric water heater, and Figure 6 is the water temperature and main temperature of the electric water heater. FIG. 3 is a temperature change diagram of a temperature sensing section of the regulator. 11... Container, 12... Concavity, 12a
...Opening, 13...Main temperature controller, 14
...Main heater, 15...Auxiliary heater. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 - Poetry Shield Figure 4 Figure 6 Temporarily open

Claims (1)

[Claims] An electric water heater comprising a container for storing a liquid, a heater attached to the container to heat the liquid, and a container provided at the bottom of the container.