JPS6315846B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a water heater that cuts off the power supply to the heating device after ensuring that water is boiled.

Structure of conventional example and its problems In general, it is preferable that the hot water used for brewing tea, coffee, or black tea is boiled water that is free of limescale and carbon dioxide gas.

There was a method that detected the water temperature by cutting off the power supply to the heating element after boiling, but in this case,
The boiling point of water is 100°C at 1 atm, requiring extremely accurate detection equipment and making boiling control practically difficult. A method was also considered to detect the steam that is rapidly generated during boiling. In this case, in order to prevent malfunctions due to steam generated before boiling, a steam passage was led out from the water container to the outside, and a steam detection element was installed near the outlet opening. It had the disadvantages of being large in size and being expensive due to the complicated steam passages.

OBJECTS OF THE INVENTION It is an object of the present invention to eliminate the above-mentioned conventional drawbacks, and to provide an electric water heater that is extremely simple in construction and has a construction that cuts off power supply to the heating device after reliably boiling water. be.

Structure of the Invention In order to achieve the above object, the present invention includes a container containing a liquid, a heating device provided at the bottom of the container, and a mounting member provided at the upper portion of the container and having a vapor detection element. , a lid covering the upper surface of the container and having a steam discharge port, and a shielding plate having a ventilation hole, a steam passage is formed between the lid and the shielding plate, and a steam passage is formed between the lid and the shielding plate. This structure keeps the steam detection element at a low temperature until the water in the container boils, and guides the steam that is rapidly generated due to boiling to the steam passage. It is capable of activating a vapor detection element.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. In Figures 1 to 3, 1
1 is a cylindrical container outer body, and this container outer body 1 has a spout 2 fixed to its upper opening and a bottom plate 3 integrally attached to its lower end. 4 is a handle rotatably attached to the spout 2. Reference numeral 5 denotes an upper lid that covers the spout 2 so that it can be opened and closed.The upper lid 5 is configured to be able to be opened and closed using a back portion 5a as a fulcrum and lock knobs 6 provided on both sides of the front beak portion 5a. A cylindrical portion 5c with an open top is provided in the center of the upper lid 5, and a push plate 7 that is vertically slidable is provided within the cylindrical portion 5c. Reference numeral 8 denotes a lock ring for regulating vertical sliding of the push plate 7. This lock ring 8 is engaged with a switching lever 9, so that the vertical movement of the push plate 7 can be selected.

Reference numeral 10 denotes a bellows pump provided at the lower part of the push plate 7, and its upper end opening is attached to the upper plate 11 by ultrasonic welding or the like and sealed. In addition, the upper plate 11 has a ventilation hole 11a in the center.
a is closed by a movable valve 13 that operates at the lower end of a push rib 12a provided at the center of the steam cover 12 integrally engaged with the push plate 7 when the push plate 7 moves downward; is configured to open the vent 11a when the push plate 7 moves upward. Also, the movable valve 13 and the bellows pump 10
A return coil spring 35 of the bellows pump 10 is interposed between the bellows pump 10 and the inner bottom 10a of the bellows pump 10. 10b
is a spout provided approximately at the center of the inner bottom portion 10a. Further, the bellows pump 10 is fixed at its lower end to a lid cover 14 that closes the lower end opening of the upper lid 5, and communicates with a discharge port 16a of a lid body 16 made of synthetic resin via a lid packing 15.

17 is a communication packing that airtightly connects the vent 11a provided in the top plate 11 and the steam cover 12, and the steam cover 12 and the steam hole 5d provided in the top cover 5 are connected by a connecting pipe 18. 19
is a bottomed cylindrical container installed inside the container outer shell 1,
It has a flange portion 19a at its upper end and is supported by the spout 2 via a container packing 20. Further, the lid 16 placed on the upper surface of the container 19 has a discharge port 16a for discharging steam at its center, and a valve chamber 22 containing an overflow prevention valve 21. A shielding plate 23 made of a stainless steel plate or the like is fixed to the lower surface of the lid 16 with screws or the like, and a steam passage A is formed by this shielding plate 23 and the lid 16.

24 is a waterproof packing, and this waterproof packing 24 keeps the container 19 and the lid 16 airtight. Reference numeral 25 denotes a water rising pipe extending from the valve chamber 22 to the bottom of the container 19. The water rising pipe 25 has an upper end extending outward from the container 19, and a spout 26a opening downward at its tip. It is connected in the valve chamber 22 via a discharge pipe 26 and a valve cover 27. 28 is an L provided at the bottom of the shielding plate 23
The vent hole 23b having a letter-shaped passage is a drainage hole having a smaller diameter than the vent hole 28.

Reference numeral 29 denotes a mounting member made of polysulfone resin or the like, which is provided in the upper part of the container 19 and to which the vapor detection element is attached. It is in communication with the steam passage A through a through hole 23a provided in 23. Reference numeral 32 denotes a vapor detection element provided at the tip of the mounting member 29 via a thermopacking 33. This vapor detection element 32 uses a manual reset type thermoswitch, and the heat-sensitive surface is placed inside the mounting member 29 by the mounting plate 34. It is set up to be exposed to.

Reference numeral 36 denotes a display plate fixed to the outer shell 1 of the container, in the center of which is provided a water conduit 37 that guides the hot water coming out of the spout 26a to the outside of the container, and on the front side is a thermoswitch 32 which is a vapor detection element. An operating lever 38 is provided for setting. 39 is a water level gauge window.

Reference numeral 40 denotes a band-shaped heating device provided on the outer peripheral surface of the bottom of the container 19, in which a heater 40a for boiling water and a heater 40b for keeping warm are integrated. Near the top of this heating device 40, a water boiling thermo 41 and a safety thermo 42 connected in parallel with the thermo switch 32 are arranged. 43a is a heat retention heater 40b
A thermal reed switch 43bb is a temperature fuse, and this temperature fuse 43b is pressed and held against the bottom surface of the container 19 by a presser spring 44. As shown in FIG. 3, the electric circuit includes a water heater 41 and a thermoswitch 32 forming a parallel circuit, which are connected in series to a water heater 40a and a safety thermos 42. 45 is an electrical connector, and 46 is a back plate.

Next, the operation of the above configuration will be explained.
First, water is poured into the container 19 so that it does not reach the mounting member 29, and then the thermoswitch 32 is set to ON, and power is supplied to the heating device 40. By supplying power to the heating device 40, the water in the container 19 is heated, and the water temperature rises as shown by the solid line in FIG.
At the same time, the temperature of the container space 3 and the steam passage A, which are formed by the water surface and the shielding plate 23, rises more slowly than the water temperature, as shown by the dashed line. Furthermore, since the thermoswitch 32 provided on the mounting member 29 faces the steam passage A, the temperature remains lower.

Then, the water temperature in the container 19 is about 95℃ (t ₁
When the temperature reaches point ), a rather large amount of steam begins to come out, and the temperature of the container space B becomes close to the water temperature. However, only weak steam enters into the steam passage A from the vent hole 28, and this steam is discharged from the discharge port 16a and separated by the shielding plate 23, so that the temperature inside the steam passage A is reduced. The temperature rises relatively slowly. Of course, the thermo switch 32 is in the steam passage A.
is maintained at an even lower temperature.

When the water temperature reaches the boiling point (time _t2 ), a large amount of steam is suddenly generated and fills the container space B, and then fills the steam passage A through the vent hole 28, causing a rapid temperature rise. At the same time, the steam passage A and the through hole 23a
Steam also enters into the mounting member 29, which is in communication through the thermoswitch 32, and rapidly raises the temperature of the thermoswitch 32, causing it to operate. In this case, the operating temperature _T3 of the thermoswitch 32, which is the vapor detection element, is turned off at 80 to 90°C.
It is set to work, and the temperature rises rapidly after the water boils, so it works reliably.

In addition, after the power supply to the water boiling heater 40a of the heating device 40 is cut off due to the OFF operation of the thermo switch 32, the water heating heater 40b is turned on at approximately 9.5 oz.
The water temperature is maintained at ℃. Therefore, a large amount of steam is no longer generated, and the steam passage A and thermo switch 32
The temperature also drops below the water temperature. When the thermo switch 32 is turned on again after the temperature of the thermoswitch 32 falls below the OFF operation, the water is heated and boils.
A large amount of steam is generated again and the temperature of the container space B and the steam passage A is rapidly raised in the same manner as above, and at the same time, the temperature of the thermoswitch 32 is rapidly raised and turned off.

Next, a case will be described in which about half of the hot water in the container 19 is taken out, water is poured in, and the thermoswitch 32 is turned on again.

When water is poured at time t4 in FIG. ₄ , the water temperature rapidly drops in both the steam passage A and the thermoswitch 32. Furthermore, when the water is heated by the heating device 40, the temperature of the steam passage A increases later than the water temperature. The temperature of the thermoswitch 32 falls later than the water temperature due to the residual heat of the container 19 and the mounting member 29, but even if the water temperature starts to rise, the temperature of the mounting member 2
The ambient temperature is maintained at 9°C. When the water temperature reaches the boiling point, a large amount of steam fills the container space B and steam passage A, and the steam also enters the mounting member 29, rapidly raising the temperature of the thermoswitch 32 and turning it off.
Activate.

Note that the steam coming out of the discharge port 16a of the lid 16 passes through the internal vent 11a of the bellows 10 and enters the steam hole 5.
d is discharged from the vessel. In addition, since the thermo switch 32 and the water boiling heater 40a are connected in parallel, if the thermo switch 32 is turned on without being set, the water boiling thermo 41 detects the water temperature and 95
When the water temperature reaches around ℃, the water heater 4
Turn off the power to 0a and boil water.

Furthermore, by providing the opening of the ventilation hole 28 of the shielding plate 23 facing the mounting member 29, when water boils and a large amount of steam is generated, the steam is vigorously injected to the thermoswitch 32, making it more reliable. It performs the operation.

In addition, in the above embodiment, the vapor detection element 3
Although a thermoswitch is used as the vapor detection element, a temperature-dependent resistance change element such as a thermistor or a shape memory alloy may be used as the vapor detection element to detect the temperature and turn off the power to the heating device.

Also, a mounting member 29 to which the vapor detection element 32 is attached.
has been described with respect to the spout 2 located above the container 19, the mounting member 29 is provided on the spout 2 located above the container 19, the lid 16 is provided on the upper end of the spout 2, and the shielding plate 23 is provided. The steam passage A formed by the lid 16 and the mounting member 29 may be communicated with each other.

Furthermore, if the mounting member 29 is made into a long cylindrical shape of about 10 to 30 mm, the temperature difference between the temperature of the vapor detection element 23 and the water temperature can be further increased.
Needless to say, it is possible to bring about reliable boiling and to re-boil water that has already been boiled while being kept warm.

Effects of the Invention As described above, the present invention provides the following excellent effects.

(b) A mounting tube having a vapor detection element is provided in the upper part of the container, and a compartment is formed by a lid and a shielding plate that covers the top surface of the container, and this compartment and the mounting tube are communicated with each other. Therefore, the power supply to the heating device can be reliably cut off after the water in the container boils and a large amount of steam is generated.

(b) Since the vapor detection element is attached to the upper part of the container, the mounting configuration is extremely simplified and the cost can be reduced.

(c) Since the steam detection element is not located outside the lid of the container, it can detect steam without ejecting steam outside the container, and therefore detects steam discharged from the steam outlet outside the container. Compared to conventional methods, there is less risk of burns, etc.

(d) Even in an air pump type water heater as shown in the embodiment, the same pump device as the conventional system can be used without requiring a special passage for steam detection, and as a result, the configuration can be simplified. It is something.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a water heater showing an embodiment of the present invention, Fig. 2 is a vertical sectional view of the water heater, Fig. 3 is an electric circuit diagram of the water heater, and Fig. 4 is a diagram of the water heater. It is a temperature one-hour characteristic diagram of each part. 16... Lid body, 19... Container, 23... Shielding plate, 29
...Mounting member, A...Steam passage, 32...Steam detection element, 40...Heating device.

Claims (1)

[Claims] 1. A container containing a liquid, a heating device provided at the bottom of the container, and a heating device provided at the top of the container,
and a mounting member having a vapor detection element, a lid covering the upper surface of the container and having a steam discharge port, and a shielding plate having a ventilation hole, wherein the lid and the shielding plate are arranged so that no steam can be detected between the lid and the shielding plate. A water heater that has a passage formed therein, and the steam passage and the mounting member communicate with each other. 2. The water heater according to claim 1, wherein the lid and the shielding plate are integrally connected and are detachable from the container. 3. The water heater according to claim 1, wherein the ventilation hole is opened facing the mounting member. 4. The water heater according to claim 1, wherein the top surface of the container and the lid are airtightly engaged.