JPH0687825B2 - Electric hot water storage container - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric hot water storage container for keeping the content liquid at a high temperature.

[0002]

2. Description of the Related Art This kind of electric hot water storage container is widely used as an electric pot for home use. Electric kettle is often to keep the hot water in the eyes of the extraction of the coffee and tea class. In particular, high temperature boiling water is required for extracting coffee. As a means to deal with this, there has been conventionally proposed one having a re-boiling function capable of boiling the content liquid once and then keeping it at a predetermined temperature and boiling the content liquid at any time as needed. There is. The heat retention control is performed by detecting the temperature of the content liquid with a sensor and turning on and off the heater based on the detection result.

[0003]

However, in the heat retention control as described above, the actual temperature during the heat retention of the content liquid changes in a wave shape as shown in FIG. 14 in response to the ON / OFF of the heater. In addition, the heater control does not easily follow the actual change in the temperature of the content liquid, and the temperature range due to the wavy change becomes comparatively large. For this reason, it has been attempted to prevent the danger by suppressing the heat retention temperature to a temperature range where boiling does not occur during heat retention.

However, under such heat retaining conditions, the content liquid cannot be kept warm at a high temperature. For this reason, when the content liquid is reboiled and used by utilizing the reboil function,
It will take a long time for the content liquid to boil. The waiting time for this is felt long, and it is desired to raise the heat retention temperature and shorten the waiting time for reboil.

Therefore, an object of the present invention is to provide an electric hot water storage container that can meet the above-mentioned requirements.

[0006]

In order to solve the above-mentioned problems, the present invention solves the above-mentioned problems by providing a room temperature sensor for detecting an ambient temperature, a liquid amount detecting means for the content liquid, room temperature information from the room temperature sensor and the content liquid. It is characterized by further comprising: a control means for determining the temperature lowering characteristic of the content liquid from the liquid amount information, and for setting a heating condition for keeping the content liquid in proportion to the determination result.

[0007]

According to the above configuration of the present invention, the control means determines the temperature drop characteristic of the content liquid during heat retention from the room temperature information of the atmosphere by the room temperature sensor and the liquid amount information of the content liquid by the liquid amount detecting means. The temperature lowering characteristic of the content liquid can be determined more practically, and the control means further sets the heating condition for keeping the content liquid warm in accordance with the result of the determination, so that the temperature of the content liquid is almost equal to the predetermined temperature. Can be stabilized.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described in detail with reference to FIGS.

In this embodiment, as shown in FIGS. 1 and 2, the heater 1 is attached to the lower surface of the bottom of the inner container 2, and the control circuit 91 including the microcomputer 66 controls the energization of the heater 1 to appropriately heat the content liquid. After being boiled once, it is kept at a predetermined temperature.

The inner container 2 is housed and held in the outer case 3,
The body 4 is formed. The mouth 2a of the inner container 2 is connected to the upper end of the outer case 3 by a shoulder member 5 made of synthetic resin,
A lid 7 is rotatably and removably pivotally attached to a bearing 9 at the rear of the shoulder member 5 by a hinge pin 6.

An inner lid 8 for closing the opening 2a of the inner container 2 is attached to the lower surface of the lid 7 and is opened and closed integrally with the lid 7.

Inside the lid 7, there is provided a bellows pump 11 which is pressed by an upper pressing plate 10 of the lid 7. The bellows pump 11 sends pressurized air into the inner container 2 through an air supply passage 13 provided between the lid 7 and the bellows pump lower plate 12 to pressurize the content liquid.

A vapor vent passage 15 is formed from the middle of the air supply passage 13 through the branch hole 14 to the upper surface of the lid 7.
The steam generated when the heater 1 keeps warm or boil is released to the outside to prevent abnormal pressure increase in the inner container 2.

The branch hole 14 is switched and closed with the discharge port 16 of the bellows pump lower plate 12 by a valve 36 that is moved downward by interlocking with the pressing operation of the bellows pump 11, and is added to the content liquid pressurized purified water discharge port 6. It prevents the compressed air from escaping to the steam vent passage 15 and the steam from entering the bellows pump 11 in the hot water storage state.

A pouring path 17 for guiding the pressurized content liquid to the upper outside of the inner container 2 is provided by connecting the base to the bottom of the inner container 2. The pouring path 17 communicates with the inner container 2 at the bottom, and the upper end is opened to the outside, so that the content liquid 42 in the inner container 2 always flows in and maintains the same level as in the inner container 2. .

At the upper end of the pouring path 17, a synthetic resin elbow 2 is provided.
An inverted U-shaped tube 23 made of synthetic resin is connected via 0. The inverted U-shaped pipe 23 is fixed to the back surface of the beak-shaped protrusion 5a formed on the front portion of the shoulder member 5, and the spout 19 at the tip is opened downward.

A water shutoff valve 25 at the time of fall is built in immediately downstream of the connecting portion of the inverted U-shaped pipe 23 with the elbow 20. Outlet 1
A slit 26 is formed on the front side of the container 9 from the lower end to a position higher than the full water level of the inner container 2. The beak-shaped protrusion 5a is provided with a pipe cover 27 that surrounds the beak-shaped protrusion 5a and the inverted U-shaped tube 23, and is fitted to the beak-shaped protrusion 5a and the outer case 3.

At the bottom of the pipe cover 27, a liquid injection guide 24 that receives the liquid spouted from the spout 19 in an open state to the atmosphere and gently flows downward is detachably attached from below. The air supply passage 13 is also provided with a water stop valve 29 at the time of falling.

The rising portion of the pouring path 17 serves as a liquid level detecting portion 17b and is made of an insulating material. Specifically who may be a glass resin tends to give the electrostatic capacitance change often dielectric constant to. Further, it is possible to suppress the unspecifiedness of the liquid surface level due to the rise due to the surface tension around the liquid surface.

The liquid level detecting section 17b includes a straight connecting pipe 17c made of synthetic resin, a curved pipe 17a made of metal, and an elbow 17 made of synthetic resin.
d, it is connected to the bottom of the inner container 2 through the metal connection port 17e.

The aluminum electrode 41 is wound around the outer periphery of the liquid level detecting portion 17b to form the first electrode, and the liquid level detecting portion 1 is used.
The bent tube 17a electrically connected to the content liquid in 7b is used as a second electrode, and the first electrode 41 and the content liquid 42 in the liquid level detection unit 17b communicating with the second electrode 17a are The position detecting portion 17b is faced with it via the insulating peripheral wall, and a capacitance corresponding to the size of the facing region, that is, the liquid level height of the content liquid 42 can be obtained.

The difference in electrostatic capacitance depending on the liquid level is that the first and second electrodes 41 and 17a are connected to the microcomputer 66 via the liquid amount detection circuit 301 as shown in FIG. Input is made to the microcomputer 66. As a result, the microcomputer 66 determines the liquid amount of the content liquid based on the input corresponding to the difference in capacitance, and according to the determination, the light emitting diode 42 for external display connected to the microcomputer 66 via the display circuit 302. _{1-42 6} drives, to external display the liquid volume.

The light emitting diodes 42 _{1 to} 42 ₆ have windows 4 on a resin panel 43 fitted to the front of the outer case 3.
The display is turned on through No. 4. Resin panel 4
A light emitting diode 80 for power-on display is provided at the bottom of 3, and this is also the microcomputer 66 in the same manner as described above.
It is connected to the.

A temperature sensor 68 provided by utilizing the central hole of the heater 1 is in contact with the center of the bottom of the inner container 2 to detect the temperature of the content liquid. The control panel 20 provided in front of the pipes cover 27
The operation circuit board 201 built in
04 is equipped with other necessary electrical components. The temperature sensor 68 and the room temperature sensor 204 are connected to the microcomputer 66 via the A / D conversion unit 205, and are used for heating control for boiling or keeping the content liquid warm.

On the operation panel 203, a reboil key 206 for boiling the content liquid at any time, a timer setting key 207 for presetting a time to finish the initial boiling of the content liquid, and a boiling state for removing scaly. Is provided with a descaling removal setting key 208 or the like for keeping the key for a predetermined time or repeating a predetermined number of times.
Reference numeral 208 is connected to the microcomputer 66 via the switch circuit 303.

On the operation panel 203, the keys 206 to
A display unit (not shown) corresponding to a control mode performed based on the operation of 208 is also provided, and is connected to the microcomputer 66 via the display circuit 302.

The microcomputer 66 controls the energization of the heater 1 and the operation of the signal buzzer 65.
A timer 77 is used to perform the time counting operation. Then, it operates based on the clock signal from the clock generation circuit 304. Further, the plug removal circuit 305 is also connected. The energization control of the heater 1 is performed by the relay 21.
1 through 1.

The operation control will be described below. FIG. 4 is a flow chart of the main routine showing the main operation control. After the power is turned on, the initial setting of step # 1 is first performed, and then the processing according to various inputs and outputs is performed (step # 2). Next, when the boiling process (step # 3) is called and the content liquid is lower than the heat retention temperature, that is, when the temperature is low due to initial water supply or addition of the content liquid, and when the reboil key 206 is operated. , Control to heat the content liquid to boiling.

Subsequently, a heat retention process (step # 4) is called to control the content liquid to be kept at a predetermined temperature after initial boiling or reboiling.

Further, timer processing (step # 5)
Is called and the timer is set by the timer setting key 207, only in the case of the initial boiling in the boiling process of step # 3, the boiling operation start time is required to boil the content liquid at the timer setting time. Delay control is performed so that the time is delayed.

Next, when the descaling process (step # 6) is called and the descaling setting key 208 is operated, the boiling operation in step # 3 is controlled to be continued for a predetermined time or repeated a predetermined number of times. To do.

Finally, after the other processing (step # 7) is completed, the process returns to step # 2 and the above control is repeated thereafter.

FIG. 5 shows a heat retention processing subroutine (step #
4) shows a flowchart of 4), and when the mode is the heat retention mode (step # 11), the processes of step # 12 and thereafter are executed. In step # 12, the room temperature data from the room temperature sensor 204 is fetched, and in step # 13, the liquid amount data from the liquid level detection unit 17b is fetched.

Next, at step # 14, the temperature lowering characteristic of the content liquid at the present time is judged from the room temperature data and the liquid amount data,
To compensate for this, the number of energized W of the heater 1 is set from a table (not shown) or the like, and in step # 15, the number of energized W of the heater 1 is changed according to the above setting. As a result, the content liquid is constantly heated in accordance with the temperature drop characteristics that change depending on the remaining amount and room temperature, and ideally realizes the constitutional heat retention control with no temperature change. By the experiment, the predetermined temperature could be maintained almost accurately, and even if the heat retention temperature was set to a high temperature of, for example, about 98 °, it did not reach boiling and could be used safely.

An example of the temperature change of the content liquid under such control is shown in FIG.

In this case, the fuzzy theory can be applied to the evaluation of various capturing conditions and the setting of the W number to further improve the control accuracy.

In addition to the capacitance method, the liquid amount of the content liquid is detected. For example, the rising portion of the pouring path 17 is made transparent, and the float is housed in the rising portion, and the height position is determined by the liquid level of the float. There is a method of detecting the change of the above with a photo sensor or the like, and a method of using other various sensors.

Furthermore, it is possible to determine the liquid amount even when sensors are not applied. 7 to 11 show a second embodiment of the present invention adapted to do this.

As shown in a part of the control circuit 91 in FIG.
The timer circuit 221 is connected to the interrupt terminal INT of the microcomputer 66, and the liquid amount of the content liquid is determined using the interrupt signal from the timer circuit 221 every 2 seconds at a predetermined time during the heat retention. .

For this liquid amount determination, as shown in FIG. 8, a liquid amount determination processing subroutine (step # 4a) is provided in the flow chart of the main routine.

As shown in the flowchart of FIG. 9A, in the liquid amount determination processing subroutine, in the heat retention mode (step # 21), the processings of step # 22 and thereafter are performed. First, the heater 1 is turned off as indicated by R in FIG. 11 (step # 22), and the IN signal from the timer circuit 221 is set.
The T interrupt is permitted (step # 23).

In this interrupt processing, as shown in FIG. 9B, the data of the content liquid temperature, which is gradually lowered with the heater 1 turned off, is read from the temperature sensor 68 (step # 41). . Next, in step # 42, the read temperature data is written in the storage position indicated by the pointer address P set in the pointer register 222. Next, in step # 43, 1 is added to the pointer address P set in the pointer register 222, the write pointer address P next to the sampled temperature data is set, and the interrupt process is ended.
The process returns to the liquid amount determination processing subroutine 4a.

This processing is performed by each pointer address P1 to P19 of the temperature series storage area 223 in the microcomputer 66 as shown in FIG.
Is repeated until the temperature data is stored and the temperature data is stored, and when the end of this process is determined (step # 24), the heater 1 is turned on as shown in S of FIG. After returning to the state (step # 25), the processes shown in steps # 26 to # 30 are performed.

Here, the temperature data in the storage area 223 is divided into four sections, and the temperature data stored in each section is added to obtain each section data. First, in step # 26, the temperature data stored in the temperature series storage area 223 is read by the pointer address P from t1 to t1.
Read in 9. In step # 27, the temperature data from the pointer addresses t0 to t4 are added to obtain the section temperature data A.

Next, at step # 28, the temperature data of t5 to t9 are added to obtain section temperature data B. Further, in step # 29, the temperature data of t10 to t14 are added to obtain section temperature data C. Finally at step # 30 t15
Up to t19 temperature data is added to obtain section temperature data D.

Next, in step # 31, the section data A is subtracted from the section data C to obtain the first section decrement data x, and in the next step # 32, the first section decrement data x.
Is 7 or less. If so, it is determined that the temperature drop of the content liquid is small and the liquid amount is large (step #
36).

If the first section decrement data x exceeds 7, it is determined in step # 33 whether it exceeds 7 and is 15 or less. If so, it is determined that the liquid amount is small (step # 34), and if not, it is determined that the liquid amount is medium (step # 35).

Then, this result is used for controlling the heat retention of the content liquid.

FIG. 12 shows a third embodiment of the present invention. Since the effect of room temperature is great during heat retention, the amount of liquid can be more accurately determined from the temperature drop characteristics of the content liquid as described above in consideration of this. This shows the case.

As shown in the figure, after taking in the liquid temperature X and the room temperature Y (steps # 51, # 52), the heater 1 is turned off (step # 53), and the temperature drop of the content liquid for liquid amount judgment is checked. When the unit time required for
4), the liquid temperature is taken in again (step # 55). Next, in step # 56, the liquid temperature Z-X is calculated to obtain the liquid temperature change amount Q. Then, referring to a separately prepared table, the liquid amount is judged from the relationship between the room temperature and the change amount of the liquid temperature (steps # 57, # 58), and when this is completed, the heater 1 is turned on and the heat retention state is maintained. Return to.

FIG. 13 shows a third embodiment of the present invention, in which the heater energization W number is set according to the temperature drop characteristic of the content liquid determined from the room temperature and the liquid amount as described above. It also takes into consideration the influence of variations in power consumption.

As shown in the figure, in the heat retention mode (step # 60), room temperature data is taken in, liquid volume data is taken in, the temperature drop characteristic of the content liquid is judged by these data, and the heater energization W number is determined by this judgment result. Are sequentially set (steps # 61 to # 64), the energized W number of the heater 1 is changed to the set W number (step # 65), and after a predetermined time, specifically, one hour has elapsed (step # 65). # 6
6), the energization W number adjustment process starts from step # 67.

In this adjustment process, the temperature data from the temperature sensor 68 is fetched (step # 67), and if the temperature is 96 ° C. or lower (step # 68), the number of energized W is increased by 2 W (step # 69), and 99 ° C. or higher. (Step # 70)
The number of energized W is reduced by 2 W (step # 71). As a result, the actual heat retention temperature matches the target temperature.

When the temperature is 97 ° C. to 98 ° C. or less (step #
68, # 70) Without making the adjustment, or if the above adjustment has been made, after the adjustment, the process proceeds to step # 72.
Every time 0 seconds elapse, the process returns to step # 67 to repeat the adjustment process and perform the heat retention according to the actual condition. However, when the heat retention mode should be released, such as when the temperature of the content liquid falls below 95 ° C. and returns to the boiling mode, this is judged and the process returns to the main routine (step # 72).

[0055]

According to the present invention, the control means determines the temperature lowering characteristic of the content liquid during heat retention from the room temperature information of the atmosphere by the room temperature sensor and the liquid amount information of the content liquid by the liquid amount detecting means. The temperature drop characteristic of the liquid is judged more practically,
The control means further sets or corrects the necessary heating conditions for keeping the content liquid in proportion to this determination result,
Since the temperature of the content liquid can be almost stabilized at a predetermined temperature, even if the heat retention temperature is set close to the boiling temperature, for example, near 99 ° C, the boiling state is not inadvertently brought about, and the high temperature content liquid is immediately added. Even when the boiled content liquid is required and the content liquid is poured out after reboiling, the waiting time can be extremely shortened.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an electric hot water storage container according to a first embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a part of the electric hot water storage container of FIG.

3 is a block diagram of a control circuit of the electric hot water storage container of FIG. 1. FIG.

4 is a flowchart showing a main routine of main operation control of the electric hot water storage container of FIG. 1. FIG.

5 is a flowchart of a heat retention processing subroutine of the slow chart of FIG.

FIG. 6 is a graph showing an example of temperature change of the content liquid in the electric hot water storage container of FIG.

FIG. 7 is a block diagram of a control circuit showing a second embodiment of the present invention.

8 is a flowchart of a main routine of main operation control of the control circuit of FIG.

9 is a flowchart of a liquid amount determination processing subroutine of the flowchart of FIG.

10 is an explanatory diagram showing a state of temperature data sampling in the flowchart of FIG.

FIG. 11 is an explanatory diagram showing the energization state of the heater and the temperature change of the content liquid by the control circuit of FIG. 7.

FIG. 12 is a flowchart of a liquid amount determination processing subroutine showing a third embodiment of the present invention.

FIG. 13 is a flowchart of a heat retention processing subroutine according to the fourth embodiment of the present invention.

FIG. 14 is an explanatory diagram showing changes in the energization state of the heater and the temperature of the content liquid in the conventional heat retention control.

[Explanation of symbols]

 1 Heater 2 Inner Container 17 Pouring Path 17b Liquid Level Detector 66 Microcomputer 91 Control Circuit

Claims (1)

[Claims] 1. A room temperature sensor for detecting an ambient temperature, a liquid amount detecting means for the content liquid, a temperature drop characteristic of the content liquid based on room temperature information from the room temperature sensor and liquid amount information of the content liquid, and a result of the determination. An electric hot water storage container comprising: a control means for setting a heating condition for keeping the liquid warm.