JPH03114421A - Electric water container - Google Patents

Abstract

PURPOSE:To achieve thermal safety of resin of the body and outer cover of an electric water container, and to prevent extra power consumption by starting boil motion mode heating in a high power supply state of a heater, then decreasing power supply of the heater after a content has reached a predetermined temperature before boiling to obtain a water boiling state. CONSTITUTION:For the convenience of control by a microcomputer 66, a keeping warm heater 1a and boiling heater 1b to be used are, for example, respectively of 60 and 740W. In water boiling and reboiling, the both heaters 1a and 1b of 800W in total are used until the water temperature rises to about 90 deg.C. When the temperature exceeds 90 deg.C, heating is switched to the 740W heating only by the heater 1b, for the purpose of preventing thermal degradation of the resin of the outer cover 7 and container body 4. In keeping water warm, only 60W heating is conducted and turned ON-OFF alternately so as to keep the water temperature at about 80 deg.C constantly. The water boiling mode power supply is conducted when a temperature sensor 68 detects that the water temperature is lower than the keeping warm one, and when a reboiling key 211 is turned ON in the water keeping warm state. The power supply returns from the boiling mode to the keeping warm mode when the temperature sensor 68 detects out that the water temperature has reached to the boiling temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to various electric hot water storage containers such as electric kettles having a mode of boiling the liquid contained therein.

(Prior art) Conventionally, this type of electric hot water storage container normally performs a boiling operation and a warming operation, and when the content liquid is below the warming temperature due to water supply or water replenishment, the content liquid is temporarily boiled by the boiling operation. After that, the content liquid is kept at a predetermined temperature by switching to the warming operation. Further, even during the heat retention operation, the content liquid can be re-boiled and used at any time by operating the re-boiling key.

The heat retention operation is performed with the heater in a low capacity energized state of about several tens of W, and the boiling operation is performed with the heater in a high capacity energized state of about 6,700 W.

(Problem to be solved by the invention) By the way, it takes a relatively long time to boil water at room temperature. For this reason, high-speed boiling that shortens boiling time has recently been desired. To satisfy this requirement, it is sufficient to increase the current carrying capacity of the heater during boiling operation. However, if boiling is performed as usual with the heater capacity increased, steam will be generated vigorously just before and after boiling, increasing the temperature, pressure, and fluctuation of the liquid level, and causing the bottom of the inner container to leak. The liquid inside is pushed out naturally through the spout channel extending outside the shoulder of the vessel.
Otherwise, it may cause spontaneous discharge, which is dangerous.

In addition, an increase in steam temperature causes thermal deterioration of the container body and the resin surrounding the outer lid. In particular, if boiling is to be continued for a predetermined period of time for the purpose of so-called descaling, which promotes the dispersion of emitted substances from the content liquid, the above-mentioned problem becomes even more serious. These things also result in unnecessary energization of the heater and wasteful power consumption.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electric hot water storage container that can solve the above-mentioned problems by improving the energization method of the heater.

(Means for Solving the Problems) In order to achieve the above-mentioned problems, the present invention starts heating in the boiling operation mode with the heater in a high-capacity energized state, and when the content liquid reaches a predetermined temperature before boiling. The first feature is that the current carrying capacity of the heater is subsequently lowered to obtain a boiling state. The second feature is that a descaling mode is performed in which the boiling state is maintained for a predetermined period of time with the heater in a low-capacity energized state to evaporate the emitted substances in the content liquid.

(Function) In the boiling operation mode, the heater is turned on with high capacity current until the content reaches a predetermined temperature before boiling, which accelerates the temperature rise, especially in the low temperature range where the temperature rises slowly. I can do it. Then, when the pre-boiling temperature reaches a predetermined temperature, the heater is switched to a low-capacity energized state, so that the further temperature increase rate of the content liquid is particularly slowed down, since the content liquid has reached the pre-boil pre-determined temperature. It is possible to reliably raise the temperature to a boiling state without any trouble.

In addition, there is a descaling mode that maintains the boiling state for a predetermined period of time.
Since the heating is carried out in a low capacity energized state of the heater, once the content liquid has been boiled, boiling can be sustained in a lower capacity energized state.

(Example) To explain the first example of the in-port eR shown in Figs. It forms a vessel body 4. The outer case 3 and the inner container 2 are connected by a shoulder member 5 at the upper end, and by a connecting fitting (not shown) and a bottom member 1 at the lower end.
It is unified by 8. The upper end of the vessel body 4 has an outer M7
is applied. The outer lid 7 is removably supported by a shaft 6 on a bearing 9 provided at the rear of the shoulder member 5, and opens and closes the container body 4 by rotating around the shaft 6.

Inside the outer lid 7 is a bellows pump 11 which is pressed by a top pressing plate 10, and a pressing plate 1 disposed in the center of the bellows pump 11.
A valve 36 that is moved up and down in conjunction with the operation of 0 is provided. The valve 36 is connected to the discharge port 16 of the bellows lower plate 12 and the branch hole of the steam vent passage 15 which branches from the middle of the air supply path 13 to the inner container 2 to which the discharge port 16 communicates and which communicates with the outside of the outer lid 7. 14 are alternately closed in conjunction with the operation of the press plate 10. Normally, when the pressure plate 10 returns to the upward movement, the valve 3
6 closes the discharge port 16, so the interior of the inner container 2 is in communication with the outside through the air supply path 13, the branch hole 14, and the steam vent path 15, and the steam generated from the content liquid 42 while boiling or keeping warm. If the pressure is removed to the outside through that route, the pressure inside the inner container 2 will not increase. When the press plate 10 is pressed, the valve 36 moves downward to open the discharge port 16 and close the branch hole 14 at the same time. The liquid enters the inner container 2 through the tube and pressurizes the liquid inside. Note that an opening 8a for the air supply is formed in the inner lid 8.

An outlet path 17 for guiding the pressurized liquid to the outside and above of the inner container 2 is provided with its base end connected to the bottom of the inner container 2 (FIG. 1). This outlet path 17 communicates with the inner container 2 at its bottom, rises along the side periphery of the inner container 2, and has an upper end at the shoulder member 5 of the container body 4, which is a discharge port unit 23 for discharging the content liquid downward to the outside of the container. The inner container 2 is connected to the inner container 2 and is always open to the atmosphere, and the liquid inside the inner container 2 constantly flows in its own heat to maintain the same level as the inside of the inner container 2. The discharge port unit 23 has a built-in water valve 25 in case of overturning, and the discharge port unit 23
A slit 26 is formed on the front side of the downward discharge port 19 at the tip thereof, and extends from the lower end to a position above the full water position of the inner container 2.

A pipe cover 27 is provided below the beak-shaped portion 5a of the vessel body 4 and is fitted into the beak-shaped portion 5a and the outer case 3 of the vessel body 4. pipe cover 27
A liquid injection guide tube 24 is detachably attached to the bottom of the discharge port unit 23 to receive the liquid discharged from the discharge port 19 of the discharge port unit 23 in an open state to the atmosphere and to flow it downward.

The slit 2 is used for receiving this open state to the atmosphere.
6 is also relevant and reliably prevents siphons, splash phenomena and ejection of the contents in the case of rapid dispensing. The liquid injection guide tube 24 is removably fitted into the beak-shaped portion 5a of the shoulder member 5, receives the liquid discharged from the discharge port 19 with a slightly large diameter, and then gently squeezes the liquid while squeezing it appropriately. Let it flow downward.

The air supply passage 13 is provided with a water valve 29 at the time of overturning.

The rising portion of the content liquid outlet path 17 serves as a liquid level detection portion 17b, which is made of an insulating material. Specifically, glass may be used, but resin has a better frost melting rate, makes it easier to obtain changes in capacitance, and can suppress unspecificity in the liquid level caused by swelling due to surface tension around the liquid level. Liquid level detection part 1
7b is a straight connecting pipe 17c made of synthetic resin, and a bent pipe 17 made of metal.
a, it is connected to the bottom of the inner container 2 via a synthetic resin elbow 17d and a metal connection port 17e.

Here, an aluminum foil 41 is provided on the outer periphery of the liquid level detection part 17b.
The curved tube 17a electrically connected to the liquid in the liquid level detection part 17b is used as a second electrode, and the liquid connected to the first electrode 41 and the second electrode 17a is The content liquid 42 in the liquid level detection part 17b forms a capacitance sensor 201 that faces the liquid level detection part 17a through the insulating peripheral wall, and the size of the opposing area, that is, the liquid level height of the content liquid 42 This allows a higher capacitance to be obtained.

This difference in capacitance depending on the liquid level is determined by inputting the sensor 201 to the microcomputer 66 of the control circuit 91 as shown in FIG. As a result, the microcomputer 66 determines the liquid level of the content liquid based on the input according to the difference in capacitance, and according to the determination, the external display LED 421.42□ connected to the microcomputer 66 via the display circuit B -・・４
26 to display the liquid level externally. In particular, when the liquid level drops to a level that requires water supply to prevent dry cooking, the water supply indicator 0 LED 80 is turned on to prompt water supply. Note that for determining the liquid level, it is easy to prepare a table of the relationship between capacitance and liquid level in necessary stages, and to make the determination based on this table. LED42°~42b
, 80 are each provided on the display panel 43 on the front surface of the container body 4.

Further, a display panel 203 is provided on the front surface of the pipe cover 27. This operation panel 203 includes descaling,
Boiling and heat retention display LEDs 204, 205, and 206 and a reboil key 211 are also provided.

The microcomputer 66 includes each of the LEDs 42. ,426 and other L.
ED80.204 to 206 are also connected as display circuit B, and key 211 is also connected to microcomputer 6 as switch operation section 212.
6.

On the other hand, the heater 1 is divided into a heat retention heater 1a and a water boiling heater 1b, which are connected to a heater drive circuit 92, and a control circuit 9.
It is designed to be controlled by two relays RYI and RY2. For this purpose, contacts R-1 and R-2 of relays RYI and RY2 are connected to heaters la and lb as shown in the figure. Here, the heaters 1a and 1b are alternately wound around the mica substrate 51 as shown in FIG. 2, and the mica vi52.
53 and is enclosed in a metal case 54, which visually forms one heater 1, but it is possible to energize any combination by controlling the relays RYI and RY2 by the microcomputer 66.

For this control, each relay RYI and RY2 is controlled by a microcomputer 6.
The transistors TR1 and TR2 are controlled by transistors TR1 and TR2.

By the way, the heater 1 of this embodiment has a power of 60W under the control of the microcomputer 66, and the water heater lb has a power of 740W. Although this is adopted in this embodiment, when boiling or reboiling water as shown in Fig. 7, the temperature is 9.
Up to about 0°C, the capacity of the heaters used is 1 and 2.
When the temperature exceeds 90°C, the power is set to 800W by the heater 1b, and when the temperature exceeds 90°C, the power is switched to 740W by only the heater 1b in order to prevent heat deterioration around the outer lid 7 and the resin of the vessel body 4. In addition, when keeping warm, the heater 1a alone is turned on and off at 60 W so as to keep the content liquid at about 80°C.

The power is turned on in the boiling state when the temperature of the liquid content detected by the temperature sensor 68 (Fig. 1) is lower than the keep-warm temperature and requires boiling, and when the re-boil key 2 is turned on in the keep-warm state.
11 is turned on, and when the temperature sensor 68 detects the boiling temperature, the temperature is returned to the warming state.

When the temperature sensor 68 detects a predetermined lower limit temperature for keeping warm, the heater 1a is energized, and when the upper limit temperature for keeping warm is detected, the heater 1a is de-energized. For these controls, a temperature sensor 68 is also connected to the microcomputer 66 via an A/D conversion circuit 202.

Furthermore, under the control of the microcomputer 66, each time the reboil key 211 is turned on on the operation panel 203, the heat retention LED 20 is turned on.
6. Boil 111 LED 205, scale removal LED 204
are individually lit one after another, and a mode corresponding to the LED that has been lit for a predetermined period of time or more is set and executed.

However, if the reboiling key 211 is operated again, the operating mode setting can be changed in the same manner as described above.

The above heating control of the content liquid will be specifically explained based on the flowcharts of each subroutine shown in FIGS. 4 to 6.

In the heating control subroutine shown in FIG. 4, first, it is determined whether scale removal has been selected using the reboiling key 211 (step #1). If not, the content liquid is below 80°C or the reboiling key 211 Only when boiling is selected (steps #2 and #3), the process moves to step #5 and a boiling operation is performed. If descaling is selected in step #1, descaling F (flag)
After is set to °1" (step #4), the boiling operation subroutine in step #5 is executed. In this boiling operation, relays RYl and RY2 are connected to transistors TRI,
TR2 is turned on, relay contacts R-1 and R-2 are turned on, and heaters la and 1b are fully energized. The heater capacity at this time is 800W, and the temperature of the content liquid rises rapidly.

When the content liquid reaches 90°C, the relay RYI is turned off by the transistor TRI and the relay contact R-1 is turned off, so the heater 1a is turned off and the heater capacity ff1740 is turned off.
Switch to W heating.

Although the heater capacity is reduced, the temperature rises from 90°C to boiling relatively quickly, and thermal deterioration around the outer lid 7 and the resin of the container body 4 due to overheating can be prevented.

When it is determined in step #6 that the boiling has ended, the process moves to step #7, and it is determined whether the scale removal F is "1".If the boiling operation starts from step #2 or step #3, the scale removal F is "1". Since this is not the case, the process moves to step #8, where the boiling R end operation and the boiling notification by the buzzer BZ are performed, and then the heat retention operation is performed.At this time, the relay RYl is activated.
is turned on by transistor TRI, while relay R2 is turned off by transistor TR2. As a result, relay contact R-1 is turned on and relay contact R-2 is turned off, so that only the heater la is turned on. Therefore, only the heater 1a generates 60W, and in this state, it is repeatedly turned on and off to keep the content liquid at a temperature of about 80°C.

Here, the boiling operation from step #2 is the initial boiling Il! by water supply or water replenishment! (Dotted line in Figure 7), the boiling operation from step #3 is from the heat retention operation after boiling and corresponds to reboiling (reboiling in Figure 7).

If the scale removal F is 1" in step #7, the microcomputer 66 moves to step #10 and controls the boiling to continue for 3 minutes. By continuing this boiling, the chlorine compound trihalomethane in the content liquid is removed. It is possible to sufficiently dissipate emitted substances such as: It exhibits the so-called descaling effect. However, the duration of this boiling can be set by the user as appropriate according to the water quality, purpose, preference, etc. In addition, since the heating during the boiling is carried out using only the heater 1b with a heater capacity of 1740 W, even if the boiling continues, the outer lid 7 and the resin surroundings of the vessel body 4 will not be thermally deteriorated. Note that boiling can be sustained even after boiling has been achieved, even with a fairly small capacity heater.

When the boiling continues for a predetermined period of time, the scale removal F is reset to 0'' in step #11 and the process returns to step #8.

The details of each subroutine of the boiling operation and the warming operation are shown in the flowcharts of FIGS. 5 and 6.

Figures 8 and 9 show the second embodiment of the wood grain (4), in which the energizing capacity of the heater is reduced in several stages from just before boiling until boiling, ensuring faster boiling while still achieving boiling. This makes it possible to reliably prevent the adverse effects of accompanying temperature rises, pressure rises, and fluctuations in the liquid level.

Figure 9 shows the change in temperature of the liquid content and the current capacity of the heater used during boiling operation.The current capacity of the heater used is 800W until the liquid content reaches 90°C, and increases to 600W when the temperature reaches 95°C. Drop it.

If the boiling is to continue to remove scale even after the boiling has been confirmed, the current capacity of the heater is reduced to 400 W, which is half of the current capacity. Once the content liquid has boiled, even if the heater capacity is made extremely small, the boiling is maintained to the extent that the emitted substances are emitted, and scale removal can be achieved.

Note that the heat retention is set to 60 W as in the case of the above embodiment, but is not limited to this.

The specific control in this case will be explained based on the boiling operation subroutine shown in FIG.

When the boiling operation is confirmed (step #31), the current carrying capacity of the heater used is set to 800 W and the boiling operation is performed (step #32). Next, the boiling operation in step #32 is repeated until it is determined that the temperature of the content liquid in the boiling operation is 90° C. or higher (step #33). When the temperature reaches 90° C., the water boiling operation is performed with the current capacity of the heater used at 700 W, and the boiling determination process is started. Next, step #35) to determine whether the temperature of the content liquid is below 80°C.
If not, it means that the heating toward boiling is continuing, and in the next step #36, it is determined whether the content liquid temperature is 95° C. or higher. If not, step #34~
Step #36 is repeated, and when the temperature reaches 95° C. or higher, the current capacity of the heater used is switched to water boiling operation of 600 W (step #37).

Next, it is determined again whether the temperature of the content liquid is below 80°C (Step #38), and if not, it means that heating toward boiling is continuing, and boiling is determined (Step #38).
39) Repeat steps #37 to #39 until there is. If boiling is determined, it is determined whether descaling is selected (step #40), and if not, the process returns to the main routine and shifts to the warming operation.

If scale removal is selected in step #40, timer T is set for 3 minutes, then subtraction is started, and the current capacity of the heater used is switched to continuous boiling operation with a current capacity of 400W (steps #41 to #43). , timer T=
This process is repeated until O is determined, and boiling is maintained for 3 minutes in a low capacity energized state.

Note that in steps #35 and #38, the content liquid temperature is 8.
If the temperature is below 0°C, even though it has been confirmed that it is boiling, the content liquid has dropped below the heat retention temperature for some reason such as the influence of the outside temperature, and it is not called boiling. Since the purpose of the term has not been achieved, in order to achieve this, return to step #32 and set the current carrying capacity of the heater used to 8.
The water boiling operation is repeated from the water boiling operation at 00W to the boiling operation again.

Figure 10 shows a third embodiment of Honzon 1, in which a microcomputer or the like is used to control the energizing capacity of the heater used to change steplessly after the content liquid reaches a pre-boiling temperature, for example 90°C. It's Nishide. However, consideration is given so that the current carrying capacity of the heater used does not fall below a predetermined number of watts before the boiling point.

This predetermined wattage is the lowest wattage that can reliably achieve boiling at a reasonable rate.

The heating operation and the warming operation are performed by one heater l.

The heater l is a transistor, TR4, by the microcomputer 66.
and a relay contact R- which is provided in parallel with the triac 301 and is controlled by a microcomputer 66 via a transistor, as in the first embodiment, and which is turned on and off by a relay (not shown). 4, energization is controlled. While the relay contact R-4 is on, the heater 1 is fully energized and performs a boiling operation with a current carrying capacity of, for example, 800 W, and when a predetermined temperature before boiling is reached, the relay contact R-4 is turned off. As a result, the triac 301 becomes activated, and by controlling this with the microcomputer 66 via the transistor TR4, the content liquid is heated to boiling by reducing the current carrying capacity of the heater used, and the boiling is used to remove scale. In order to maintain this for a predetermined period of time, the current carrying capacity of the heater used can be reduced as appropriate.

Furthermore, even when switching to heat retention after boiling or after descaling, control can be performed to obtain the necessary current carrying capacity for heat retention.

FIGS. 12 and 13 show an example of simple control in this case. In this example, the heater 1 is fully energized until the normal boiling is finished, so that the energizing capacity becomes 800 W, and after that, when descaling is performed, the energizing capacity is set by repeatedly turning the heater 1 on and off for 10 seconds each. is halved to 400W. The duration of Naoriki removal is determined by counting the number of times the heater 1 is energized;
When the count number N reaches 9, that is, after 180 seconds have elapsed, it is determined that descaling has been completed, and the process returns to the main routine in order to move on to the warming operation.

FIG. 14 shows a fifth embodiment of the present invention, in which the current carrying capacity of the heater I used in descaling is changed depending on the amount of the liquid contained therein.

This prevents unnecessary power consumption due to the heater current carrying capacity being too high when the liquid level is low, and also prevents the generation of more active steam than necessary in the liquid content and large fluctuations in the liquid level. This danger can be avoided.

A specific example of this control will be explained. When boiling has finished and descaling is selected, the liquid volume is first determined, and if it is greater than if, heater 1 is turned on and off for 10 seconds each six times, and descaling continues for 120 seconds, then the main routine begins. to switch back to keep warm.

Also, the liquid volume is 1! If it is less than that, the heater 1 is turned on for 5 seconds and turned off for 10 seconds, which is repeated 8 times to maintain descaling for 120 seconds, and then returns to the main routine and switches to heat retention.

(Effects of the Invention) According to the present invention, heating in the boiling operation mode is started with the heater in a high-capacity energized state, and after the content liquid reaches a predetermined temperature before boiling, the energizing capacity of the heater is reduced and the boiling state is reached. Therefore, in the boiling operation mode, the heater is turned on at high capacity and heated until the content reaches the pre-boiling temperature, thereby reducing the temperature rise, especially in the low temperature range where the temperature rises slowly. can be accelerated, and when the predetermined temperature before boiling is reached,
By switching the heater to a low-capacity energized state and ensuring that the liquid content has reached a predetermined temperature before boiling, the temperature of the liquid content can be reliably raised to a boiling state without slowing down the rate of further temperature rise. As a result, high-speed boiling can be achieved with satisfactory thermal safety around the resin of the vessel body and outer lid, as well as suppression of natural discharge caused by fluctuations in the liquid level and rise in internal pressure due to boiling, and also waste reduction. It is also possible to prevent excessive power consumption.

Furthermore, in the case of so-called descaling, which removes emitted substances in the liquid by maintaining the boiling state, the heater is used at a low capacity energized state at least during the continuation of the boiling state.
Descaling by continuous boiling also satisfies the thermal safety of the resin around the container body and outer lid due to the heater's high-capacity energization state, and the suppression of spontaneous discharge caused by fluctuations in the liquid level and increase in internal pressure due to boiling. This can be achieved and wasteful power consumption can be avoided.

[Brief explanation of drawings]

Fig. 1 is a cut-away side view of an electric kettle showing the first embodiment of the present invention, Fig. 2 is a perspective view showing the heater base partially cut away, and Fig. 3 is a control circuit diagram. , FIG. 4 is a flowchart of the heating control subroutine, FIG. 5 is a flowchart of the boiling operation subroutine in FIG. 4, and FIG. 6 is a flowchart of the heat retention subroutine in FIG. 4.
FIG. 7 is a graph showing the relationship between the temperature change of the liquid content and the energization capacity of the heater used in each operation mode, and FIG. 8 is a graph showing the relationship between the temperature change of the liquid content and the energization capacity of the heater used in the second embodiment of the present invention. A graph showing the relationship with capacity, FIG. 9 is a flow chart of the boiling operation subroutine showing its specific control, and 1st O
The figure is a graph showing the third embodiment of the present invention, FIG. 11 is a graph showing a modified example of the fourth embodiment of zero nitration generation, and FIG.
FIG. 13 is a graph and a flowchart showing the relationship between the change in content liquid temperature and the current carrying capacity of the heater used in each mode showing a specific example of the fourth embodiment of the present invention, and FIG. 2 is a flowchart of a boiling operation subroutine illustrating an embodiment of the present invention. 1, la, 1b---- 55,301----・66-・--1-・-・-----～----・・9t-
−−１１−−−・−・・・・−−１−−・92− ・−
... RYI, RY2, ---, - TRI ~ TR4-, R-1, R-2-... Heater triac microcomputer control circuit Heater drive circuit relay transistor relay contact

Claims (2)

[Claims] (1) Heating in the boiling operation mode is started with a high capacity energization state of the heater, and after the content liquid reaches a predetermined temperature before boiling, the energization capacity of the heater is reduced to obtain a boiling state. Electric hot water storage container. (2) An electric hot water storage container characterized in that a boiling state is maintained for a predetermined period of time in a low-capacity energized state of a heater to perform a descaling mode in which emitted substances in the content liquid are emitted.