JPS5977814A - electric water heater - 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 The present invention improves temperature control characteristics when boiling water in a heat-retaining electric water heater that stores liquid in a container equipped with a heater, boils the liquid with the heater, and then continues to keep it warm. related to what was done.

As shown in FIGS. 4 and 6, a conventional electric water heater has a main heater 2 and an auxiliary heater 3 in the form of a band around the lower outer circumference of a bottomed cylindrical container 1 made of a stainless steel plate or the like. A temperature regulator 4 is mounted integrally 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. are electrically connected in parallel to form an electric circuit.

At this point, water 5 is placed in container 1 and energization is started.

Heating is started by the main heater 2 and the auxiliary heater 3, and water is boiled. As the water boiling progresses and the water 5 reaches a predetermined temperature, the temperature regulator 4 is activated to cut off the power to the main heater 2 and the 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 5 at the completion of this boiling was limited to about 96° C., and it was not possible to reliably boil the water.

This is because when looking at the change in temperature rise during boiling water due to continuous energization of the main and auxiliary heaters 2 and 3, it is the next energization. For example, the temperature rise changes at the approximately center portion 5a of the water 5 contained in the container 1 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 of the temperature sensing part 4a at point A when the water 6 starts boiling is B°C, so if the operating temperature of the temperature regulator 4 is set to a temperature at which the temperature sensing part 4a reaches B°C, the water 5 boils. However, in reality, the temperature rise of the temperature sensing section 4a is B'
In most cases, the water 6 boils continuously without the temperature regulator 4 operating due to variations in the operating temperature of the temperature regulator 4, variations in temperature sensitivity, etc. there were. Furthermore, 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, it becomes as shown in FIG.
The temperature of the temperature sensing portion 4b at time A when the water 6a starts boiling is B'°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.

The temperature change at the lower outer periphery of the container 1 when the pickled water 5 is boiled is stable at the temperature at the start of boiling in most cases because the water 5 does not rise above 100°C. Therefore, it becomes almost impossible to prepare a temperature regulator when considering the variation in operating temperature and temperature sensitivity, and the operating temperature of the temperature regulator 4 has been set within a range that does not boil, taking into consideration the variation.

Therefore, the hot water obtained with this type of conventional electric 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 electric water heaters by boiling water for a certain period of time and then keeping it at a predetermined temperature when boiling water is completed.
An embodiment of the present invention will be described with reference to the drawings.

In the figure, reference numeral 11 denotes a bottomed cylindrical container made of a stainless steel plate, etc. Around the bottom of the container, there is a band-shaped main heater 12 housed in an insulator such as mica and surrounded by an aluminum plate, etc. An auxiliary heater 13 is integrally installed. 1. On the bottom back surface of the container 11, there is a main temperature regulator 1 approximately in the center thereof for controlling the energization of the main heater 12.
4, an auxiliary temperature regulator 15 at the end that controls the energization of the auxiliary heater 13, and a
An overtemperature rise prevention device 16 that cuts off the power supply to the auxiliary heaters 12 and 13 is mounted by pressing it with a pressing spring 18 attached to a mounting fitting 17.

A seven flange portion 19 is provided at the upper end of the container 11 and extends in the outer circumferential direction, and a spout packing 2 is attached to this flange portion 19.
The spout 21 is placed on the body 22 with the spout 21 located therebetween. The body 22 is formed into a cylindrical shape and is made of a steel plate or the like and covers the outer peripheral surface of the container 11 closely.

Reference numeral 23 denotes an inner lid that is detachably placed on the flange portion 19 of the container 11, and includes a water rising pipe 24 that extends to the bottom of the container 11 and has an opening, and a spout that extends to the outside of the container 11. 25
' and the water injection pipe 25 provided with the overflow prevention valve 2.
It communicates via a valve seat 27 having a valve seat 6. A cover 28 is provided at the tip of the water raising pipe 24, which faces substantially the center of the bottom surface of the container 11, which becomes the temperature sensing portion 14a of the main temperature regulator 14 when the inner lid 23 is attached. Reference numeral 29 denotes a decorative frame that covers the back surfaces of the valve seat 27 and the inner lid 23, and a container backing 51 is provided on the outer periphery of the decorative frame 29, which is airtightly attached to the container 11. A through hole 29 is provided in this decoration 9 frame 29.

Air holes 23a and 23b are provided in the trench inner lid 23, and a steam hole 23a is provided in the periphery on the opposite side from the water injection pipe 25.

Reference numeral 30 denotes a lid which is pivotally connected to the spout 21 and houses a bellows 31, and has a cylindrical part 3 with an open top in the upper center part.
2, and within this cylindrical portion 32 is provided a push plate 34 that is vertically slidable by a spiral return spring 33 built into the bellows 31.

36 is a protection plate which presses the first check valve 36 provided in the upper opening 31a of the bellows 31 with the central lower part of the push plate 34 to open the upper opening 31a of the bellows 31 and the check valve 36.
After eliminating the gap 33'a with the seal ring 37 provided in the bellows 31, the bellows 31 is pressed at the lower part of the periphery of the pushing plate 34 via the protective plate 35. Further, the lower opening 31b of the bellows 31 is provided with a compression spring 38 inside the bellows 31.
A second check valve 39 biased inwardly from the lid cover 40 is provided and is engaged with the lid cover 40 so as to face substantially the center thereof. Reference numeral 41 denotes a steam pipe having one end opened at the top of the lid 30 and the other connected to the through hole 40a of the lid cover 40, and an interlocking shaft 42 interlocked with the pressing and returning of the pushing body 34 in the middle thereof. A steam valve 43 provided at the lower end is positioned to close the steam pipe 41 when the pushing body 34 is pressed. Note that 44 is a lock knob that locks and unlocks the lid 30 when opening and closing the main body.

45 is the lower opening 31b of the bellows 31 when the lid body 30 is closed.
and a first lid backing connected to the air hole 23a of the inner lid 23 to communicate with the inside of the container 11; and 46 connects the steam pipe 41 and the steam hole 23C of the inner lid 23 to communicate the inside of the container 11 with outside air. A lid backing, 47 a gauge section for displaying the amount of liquid contained in the container 11, 48 a hook, and 49 a back plate.

In the above configuration, when water 50 is put into the container 11 and the power is turned on, the water is heated by the main heater 12 and the auxiliary heater 13 and starts boiling water.

Here, inside the container 11, there are main and auxiliary heaters 12', 13.
As the water heated in
Since it is attached to the bottom of the heating chamber, the gradient of temperature rise with respect to heating time shows almost the same change due to the convection effect of water. However, within the cover 28, the convection of water is hindered.
The temperature rise is delayed compared to the temperature rise outside the cover 28 and becomes flat.

Figure 3 shows the temperature changes of the water 50a in the center and the water sob in the water tank 28 as representative of the temperature rise at the top and bottom of the container 11. As boiling begins and the boiling range gradually reaches the lower part, water 50 due to boiling in the container 11 increases.
The stirring becomes intense, and finally the hot water 45b inside the cover 28 is also stirred, and its temperature rapidly rises to reach boiling temperature. At about the same time, the temperature of the temperature sensing portion 14a on the bottom back surface of the container 11, which is opposite to the cover 28, also rises rapidly. In FIG. 3, the temperature of the temperature sensing part 14a at time C when the water 50a starts boiling in the approximate center is, for example, 76°C. Now water 5
If the longest boiling time of 0 is set in the range from C to E, where the temperature of the temperature sensing part 14a is not stable, the time will be, for example, 60 seconds. The temperature of the temperature sensing section 14a at point E (point F) is, for example, 90°C, which means that the operating temperature at which the electric circuit of the main temperature regulator 14 is opened is approximately 76°C.
If the temperature is set within the range of 90°C to 90°C, the water 50 contained in the container 11 will start boiling, and the main temperature regulator 14 will operate within 60 seconds to complete boiling.

Note that the auxiliary temperature regulator 16 cuts off the power to the auxiliary heater 13.
The operating temperature is set to a temperature that does not boil when keeping warm, and operates before the water 50 boils when boiling water.

Next, when the temperature of the water 50 falls to a predetermined temperature, the auxiliary temperature regulator 15 operates to close the electric circuit and start supplying electricity to the auxiliary heater 13 again. Although heating by this auxiliary heater 13 requires much less electricity than boiling water,
When this heating progresses and the temperature of the water 50 rises to a predetermined temperature again, the auxiliary temperature regulator 16 operates again to cut off the power to the auxiliary heater 13, and by repeating this process, the water 50 is kept at a constant temperature. The operating temperature range of the auxiliary temperature regulator 15 is narrower than the operating temperature range of the main temperature regulator 12, so that the operating temperature range of the main temperature regulator 14 is made narrower than the operating temperature range of the main temperature regulator 12, so that the operating temperature range of the main temperature regulator 14 is made narrower than that of the main temperature regulator 14 before heating is performed by the auxiliary heater 13 due to the closing operation of the auxiliary temperature regulator 16. Heating by the main heater 12 is not performed, so that the boiling described above due to energization of the main heater 12 is not repeated during heat retention. However, by pressing the push plate 34, the container 1
1. 6 o of water is raised in the water pipe 24. Valve seat 27. When a certain amount or more is poured out from the spout 25' through the water injection pipe 25 and water is again supplied into the container 11, the temperature of the water 5o becomes lower than the closing operation temperature of the main temperature controller 14 and the auxiliary temperature controller 15, and the above-mentioned state is again performed. Repeat the action for a certain period of time $/I! L It is something that is kept warm.

In the above description, the amount of water 5o is almost full, but if the amount is small, the boiling time will be shorter, and although the boiling time will be slightly longer, the water will be kept warm after boiling for a certain period of time.

In addition, in this embodiment, the water rising pipe 24 is placed opposite to the temperature sensing part 14a of the main temperature regulator 14 provided on the bottom back surface of the container 11.
The cover 28 provided at the lower end is made thicker than the water rising pipe 24, but if it is possible to reliably cover the temperature sensing portion 14a, the water rising pipe 24 should be extended to near the bottom of the container 11. The cover 28 may also be extended to serve as the cover 28. Furthermore, the cover 28 may be made of an elastic material such as rubber, and its lower end may be brought into contact with the bottom surface of the container 11 to sufficiently prevent the convection of the water 5o. In addition to widening the operating temperature setting of the temperature controller 14, water absorption holes are provided on the top surface of the cover 28 or the side of the water rising pipe 24 to increase the amount of water remaining in the container 11, thereby increasing the amount of water remaining in the container 11. You may try to prevent dry baking.

Furthermore, with this type of boiling type electric water heater, if you forget to attach the inner lid, hot water will spray out from between the spout and the lid, creating a risk of burns, but in the present invention, it is integrated with the inner lid. The tip of the water rising pipe is facing the temperature sensing part of the main temperature regulator, and if the inner lid is not attached, the convection action at 12 o'clock in the boiling period is not hindered, so the main temperature regulator operates before boiling. This eliminates the above-mentioned danger.

In other words, in the present invention, as explained above, a rapid temperature rise is generated in the temperature sensing part of the main temperature regulator by the convection action during heating of the liquid in the container and the stirring action during boiling, and this temperature rise causes the main temperature to rise. It controls the boiling time at a constant level by absorbing variations in the operating temperature of the regulator and variations in temperature sensitivity, etc. It is simple and does not require any other control means such as conventional timers or electronic control circuits. This was made possible by a configuration that
It has great 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 water heater, and Fig. 3 is a diagram showing the water temperature of the water heater and the temperature sensing section of the main temperature controller. Fig. 4 is a partially cutaway side view of a conventional electric water heater, Fig. 6 is an electric circuit diagram of the water heater, and Fig. 6 shows the water temperature of the water heater and the main temperature controller. It is a temperature change diagram with a temperature sensing part. 11 Container, 12.13 Heater, 1
4...Main temperature regulator, 14a...River/temperature sensing section, 23...Inner lid, 24...mark/water rise pipe. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 1 Figure 4 Figure 5 Figure 6 - Poem Y

Claims (1)

[Claims] A container for storing a liquid, a heater attached to the container to heat the liquid, and a temperature regulator for controlling energization of the heater, with a part of the bottom surface of the container serving as a temperature sensing part, The lid body is provided with a water rising pipe that extends and opens at the bottom of the container, and the open end of the water rising pipe is disposed close to the bottom surface of the container and covers the temperature sensing part. An electric water heater made of