JPS60253419A - Boiling type 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] [Technical field of invention] This invention relates to improvements in boiling type electric kettles.

[Technical background of the invention and its problems] In conventional electric pots, water is supplied into the pot, the water is raised to a predetermined temperature, for example, 92°C, and the water boiling control is stopped when this temperature reaches 92°C. The device was designed to switch to heat-retaining operation. For this reason, conventional electric pots have the problem of not being able to control the boiling of water in the pot. By the way, when boiling water in a pot, if the pot is sealed, the pressure inside the pot will be high, which is extremely dangerous.

This requires a structure that allows the steam inside the pot to escape, but in addition to this structure, it also detects when the water in the pot has risen to nearly 100°C, the boiling point, and turns on electricity to the water heater. Control is required to stop this. However, when a temperature sensor is used to detect the boiling point, the accuracy of the concentration sensor at high temperatures is required. For example, if the temperature sensor malfunctions and does not detect a point exceeding 100 degrees Celsius, power to the water heater will stop. If this happens, even if the water in the pot boils, the power to the heater will not be stopped, which is extremely dangerous.

[Purpose of the Invention] This invention was made to solve such problems, and it is an object of the present invention to reliably bring the water in the pot to a boil, and to reliably stop energizing the water heater after boiling. The purpose is to provide a highly safe boiling electric kettle.

[Summary of the Invention] The present invention includes a water heater for boiling and controlling the water in the pot, a water temperature detector for detecting the water temperature in the pot, and a start switch for starting water heating control in the pot. When the switch is turned on, the water heater starts to be energized, the water temperature detector starts to detect the water temperature, and starts counting the energization time. Read the count energization time, calculate the rate of change in water temperature over time from the starting water temperature, rising temperature, and count energization time, calculate the time until the water in the pot boils from that rate of change, and calculate the time until the water in the pot boils. The electricity supply to the water heater is controlled based on the electricity supply time determined.

[Embodiments of the invention] Embodiments of the present invention will be described below with reference to the drawings.

In the figure, reference numeral 1 denotes a cylindrical case forming an outer cylinder of the pot, and a support plate 2 is attached to the upper opening of the case 1. This support plate 2 has a large opening 3 in the center, and a stepped portion 4 is formed around the periphery of this opening 3. A tank 5 is housed inside the case 1 and is formed into a cylindrical shape with a bottom and forms an inner cylinder of the pot.
The flange 6 is in contact with the step portion 4 via the backing 7. An upper cover 8 is provided on the upper surface side of the support plate 2, and the upper cover 8 is rotatably attached to the support plate 2 via a pin 9. A lock button 13 is provided on the upper lid 8, located on the opposite side of the pin 9, so that the lock button 13 can move forward and backward.
This button 13 has an engaging claw 14 that engages with an engaging receiving portion 15 formed on the support plate 2. The lock button 13 is biased leftward in the figure by a spring 16, and this biasing force maintains the engagement between the engagement pawl 14 and the engagement receiving portion 15. By moving the lock button 13 rightward in the figure against the spring 16, the engagement between the engagement pawl 14 and the engagement receiving portion 15 can be released.

An inner cover 18 is provided inside the upper cover 8.
An annular groove 19 is formed on the outer circumferential surface of 8. A pair of locking bodies 20 and 21 are provided on the upper lid 8 and facing each other.
These locking bodies 2o and 21 engage with the annular groove 19. One of the locking bodies 2o is fixed to the upper lid 8, while the other locking body 21 is supported so as to be movable forward and backward. This locking body 21 integrally has a knob 22 and is biased leftward in the drawing by a spring 23, and this biasing force maintains the engagement between the locking body 21 and the annular groove 19.

Then, by pinching the knob 22, the locking body 21 is attached to the spring 23.
By moving the locking body 21 and the annular groove 19 to the right in the figure against the movement, the engagement between the locking body 21 and the annular groove 19 can be released. It has become. A backing 25 is attached to the periphery of the lower end opening of the inner lid 18, and this backing 25 is in airtight contact with the flange 6 of the tank 5. Further, a steam cylinder 24 is integrally formed in the center of the upper surface of the inner lid 18 to protrude, and the upper end surface of the steam cylinder 24 is exposed flush to the upper surface of the upper lid 8 through the backing 17, and a plurality of passages are provided on this exposed surface. Stomata 26・
...is drilled. A safety valve mechanism 27 is provided inside the steam cylinder 24. To explain this safety valve mechanism 27 in detail, 28 is a partition plate attached to the lower end opening of the steam cylinder 24, and the partition plate 28 has an opening in the center. 29 is formed. Below the partition plate 28 is a valve holder 30.
The valve holder 30 is provided with a truncated conical recess 32 having a tapered surface 31, and a truncated conical valve body 33 made of rubber or the like is housed in the recess 32.゛The movable plate 34 has an opening 29 on the top surface of the partition plate 28.
The movable plate 34 is provided facing the spring 10.
It is pressed downward by the biasing force of , and comes into pressure contact with the partition plate 28 , and has an escape port 11 in the center that constitutes a communication section that communicates the inside of the tank 5 with the atmosphere.
1 faces the valve body 33 at a distance. In addition, 12
is a protective cover that covers the outer periphery of the valve holder 30.

A water boiling heater 35 and a heat-retaining heater 96 formed in the shape of a strip are wound around the outer periphery of the lower end of the tank 5, and a water temperature detector 36 made of, for example, a negative characteristic thermistor is placed in the middle thereof.
And a heat retention thermoswitch TR8 is attached. A lead-out pipe 37 is attached to the lower end of the tank 5, and the leading end of the lead-out pipe 37' is inclined diagonally upward so that the lead-out pipe 37' is connected to the case 1.
It protrudes outward from the front side. An on-off valve mechanism 38 is provided at the protruding end portion of the on-off valve mechanism.
0 is inserted through the operating shaft 40 so as to be freely forward and backward, and first and second valve bodies 41 and 42 made of an elastic material such as rubber are attached to the operating shaft 40, respectively. The operating shaft 40 is biased leftward in the figure by a spring 43, and this bias causes the first and second
The valve bodies 41 and 42 of the valve bodies 41 and 42 each elastically abut against the peripheral wall of the valve port 39, thereby closing the valve port 39 in a fluid-tight manner. The second valve body 42 integrally has a cylindrical thin wall portion 45 on its periphery, and this thin wall portion 45 is elastically deformed to spread around its outer periphery due to the biasing force of the spring 43, so that the thin wall portion 45 is elastically deformed around the valve port 39. Close to the wall.

Therefore, when the operating shaft 40 is operated to move rightward in the figure against the spring 43, the first valve body 41 first moves toward the valve opening 3.
9, and then, with a slight delay, the second valve body 42 separates from the peripheral wall of the valve port 39, and the valve port 39 is opened. When the operating shaft 40 moves to the left in the figure due to the biasing force of the spring 43, contrary to the above, the second valve body 42 first comes into contact with the peripheral wall of the valve port 39, and then the first valve body 42 comes into contact with the peripheral wall of the valve port 39. The valve body 41 abuts against the peripheral wall of the valve port 39 . Therefore, the valve body 4
There is no case where only one of the valve bodies 41.42 contacts the peripheral wall of the valve port 39 and the other does not, and both valve bodies 41,42 are always in contact with each other, so that the valve port 39 is reliably closed. Even if the second valve body 42, which is in direct contact with high-temperature water, deteriorates relatively early, the first valve body 4
1 can maintain the closed state of the valve port 39, so water flows through the valve port 3.
There is an advantage that there is no possibility of leakage.

A support fitting 48 is provided on the lower end surface of the tank 5, and a saucer 49 and a controller case 50 are attached to the lower end of the support fitting 48. The saucer 49 is inclined in one direction, and a discharge port 5'1 is formed in a part of the lower end of the slope.
A discharge pipe 52 is connected to 1. A control part 53 is provided inside the controller case 5o, and a large number of lead wires 54 led out from the control part 53 are passed through the backing 55 provided at the lower edge of the controller case 5o to the controller case 5o. It is drawn out to the outside of 50. A terminal 56 that is electrically connected to the heater 35, 96, the water temperature detector 36, and the thermoswitch TR8 is provided on the lower end surface of the tank 5, and the above-mentioned single lead wire 54 is connected to this terminal 56. A leg body 60 formed in an annular shape is attached to the lower end opening of the case 1, and a bottom plate 6 is mounted inside the leg body 60.
1 is provided, and a set screw 62 is screwed from the bottom plate 61 to the controller case 50, and by tightening the set screw 62, the flange 6 of the tank 5 is crimped to the backing 7, and the lead wire 54...・Backing 5 that was pushed through
5 is compressed, and the inside and outside of the controller case 50 are sealed.

A fall switch mechanism 68 is provided on the top surface of the bottom plate 61,
This overturning switch mechanism 68 includes a base 64 having a truncated conical recess 63 having a tapered surface 63a, and a base 64 having a truncated conical recess 63 having a tapered surface 63a
A truncated conical heavy housed in 3 #! 65 and base 64
It consists of a microswitch 69 attached to the upper end surface of. The microswitch 69 has a push button 66 that protrudes elastically, and the pushing and retracting operation of the push button 66 opens and closes the energizing circuits for the heaters 35 and 96. A movable operation plate 67 is provided on the upper surface of the recess 63.
is provided, and the push button 6 is located across the operation panel 67.
6 is facing the weight 65.

A transparent water level pipe 7o that communicates with the upper and lower ends of the tank 5 is vertically provided on the outside of the side surface of the tank 5.
protrudes to the outside of the front side of the case 1. A decorative board 71 is attached to the front of the case 1, and this decorative board 71 is attached to the second
As shown in the figure, it consists of a display section 72 in the upper half and a cover part 73 in the lower half. The display section 72 has a vertical measuring window 74.
A transparent metering cover 75 is attached to the metering window 74 from the inside with screws 76, and the water level pipe 7o is disposed facing inside the metering cover 75. The amount of water in the tank 5 can be known by visually observing the amount through the metering window 74 and the metering cover 75.

Further, inside the display section 72, an operation board 78 is attached with screws 79.
The operation board 78 includes a start/cancel switch 80a, a timer switch 80b, a boiling switch SOC, and each of these switches 80a to 80c.
Operation buttons aia, aib, 81C1 for operating the and display elements (LEDs) 82a to 82 for displaying the control status
n are arranged in a concentrated manner. The operation buttons 81a to 81c and the display elements 828 to 82n are connected to the display section 7.
It faces the front surface of the display section 72 through the notch holes 83 . . . , 84 . A cover portion 73 in the lower half of the decorative plate 71 protrudes forward and covers the opening/closing valve mechanism 38. A pouring button 90 is provided inside the tip of this cover part 73, and this pouring button 9
0 is rotatably supported via a bottle 91, is biased clockwise in the figure by a spring 92, and has a protrusion 93 on the side surface, and this protrusion 93 serves as an operating shaft in the opening/closing valve mechanism 38. 40 and are in contact with each other.

By rotating this pouring button 90 counterclockwise in the figure using the pin 91 as a fulcrum against the spring 92, the operation shaft 40 is moved to the right in the figure and the valve port 39 is opened. Water in the tank 5 can be poured out through a spout 95.

FIG. 3 shows a control circuit for controlling the boiling type electric kettle according to the present invention, and this control circuit is housed in the controller case 50. The control circuit includes a central processing unit (CPU) and a random access memory (RAM).
, read-only memory (ROM), various I10
A microcomputer 100 is provided which includes a built-in board, a clock signal generator, an A/D conversion circuit, etc., and this microcomputer 100 includes a power transformer, which is well known as a power source, a full-wave rectifier circuit, a transistor, a resistor element, etc. A stabilized power supply circuit 101 is connected thereto. Further, the micro switch 69. is connected to the commercial AC power supply 101'a. and normally open contact R of water heater relay RL1
For example, the water heater 35 of 670 W is connected via L1a in series, and the micro switch 69 is
and the heat retention heater 96 and the thermo switch TR8 via the normally open contact RL2a of the heat retention heater relay RL2 in series.
A series circuit with is connected. Each of the relays RLI, R
One end of L2 is connected to the positive terminal of the full-wave rectifier circuit in the stabilized power supply circuit 101, and the other end is connected to the microcomputer 100, and its operation is controlled by signals from the microcomputer 100. There is. The water temperature detector 36 is a Zener diode ZD.
, the microcomputer 10 via a reference voltage circuit 102 composed of resistors R1 to R4 and a capacitor C.
Connected to 0. Further, the start/cancel switch 80a, the timer switch 80b, and the boiling switch 80c are connected to the microcomputer 100 via diodes D1, D2, and D3, respectively. Further, the display section 72 is connected to the microcomputer 100 via resistors R1 to R9.

This display section 72 has the display elements 82a to 82n connected in a matrix circuit, with 82a being an LED for indicating boiling water, 82b being an LED for indicating completion of boiling, and 82c being an LED for indicating normal water boiling. , 82d are LEDs for displaying heat retention, and 820 to 82n are LEDs for displaying timer settings.

When the power supply 101a of the microcomputer 100 is turned on, the stabilizing voltage f! When voltage is output to 101,
An interrupt is generated at regular intervals according to a command from the CPU, and the interrupt processing shown in FIG. 4 is performed. That is,
When this process begins, other interrupts are first prohibited. Each time an interrupt is entered, the LEDs 82a to 82n are changed to a predetermined number, for example, LEDs 82a to 82d, 82e to 821182j to
The lights are turned on alternately in groups of 82n. This LED
Following the lighting process, the timer function performs a counting operation. This counting operation is performed every 8 interrupts, and for example, when the boiling switch 80c is operated, it takes 10 seconds to accept the start/cancel switch 80a, and after the start/cancel switch 80a is operated. It is used to count the energization time to the water heater 35, the timer setting time, etc. Next, it is checked whether the water temperature detected by the water temperature detector 36 is 110"C or higher, and if it is 110"C or higher, it is determined that the dry cooking is being performed and a dry cooking set flag is set.
If the temperature is lower than ℃, start/cancel switch 80a and timer switch 80b are activated.

The state of the boiling switch 80c is captured. If the start/cancel switch 80a is in the on state, check whether this switch 80a was also in the on state at the time of the previous interrupt.
It is determined by reading from AM, and if it was on the previous time, the count for the next interrupt is shifted. However, if it was turned off last time, it is checked whether the electric kettle is currently in operation. If the switch is in the operating state, the switch operation is determined to be a cancellation operation and set to cancel, and if it is not in the operating state, it is determined to be a start operation and the operation is set to start. Further, if the previous start/cancel switch 80a is off, then it is checked whether the timer switch 80b is on. If the timer switch 80b is on, the count of the timer function is cleared and the timer function is set again. Further, if the timer switch 80b is off, then it is checked whether the boiling switch 80c is on. If this switch 80C is turned on, the count of the timer function is cleared and the boiling operation is set. Finally, a shift is performed to count the occurrence of the next interrupt, the interrupt is enabled, and this interrupt processing is completed.

Further, the microcomputer 100 is shown in FIGS.
The main control processing shown in the figure is performed. First, in FIG. 5, the microcomputer 100 has a start/cancel switch 80a, a timer switch 80b, and a boiling switch 8.
The state of 0c is read and commands are issued according to the states of these switches.

This process first enables interrupts, then performs initialization,
Check the empty cooking set flag. If this flag is set, it is determined that the cooking is empty, and each LED 82a
~ 82n is flashed and water heater relay RLI is turned off.

Here, the dry cooking temperature was set at 110°C because the temperature at boiling never exceeds 100°C, and also because of the reliability of operation. When in the dry cooking state, the state of the start/cancel switch 80a is also taken in, and if this switch is on, the energy saving/warming operation shown in FIG. 7 is controlled. On the other hand, if it is not in the dry cooking state, the state of the timer switch 80b is read. This switch 8
If this switch 80b is in the on state, the timer setting control shown in FIG. 8 is performed, and if this switch 80b is in the off state, the state of the start/cancel switch 80a is taken. If the start/cancel switch 80a is on, the control shown in FIG. 7 is carried out, and if it is off, the water temperature detector 36 checks whether the water temperature is below 85°C. If the water temperature is higher than 85°C, the control shown in FIG. 7 is carried out, and if the water temperature is below 85°C, the state of the boiling switch 80c is taken next. If this switch 80C is off, the process is returned to the initialization described above, and if this switch 80c is on, this switch 80C is turned off.
Check whether 10 seconds have passed since c was turned on, and turn on the start/cancel switch 8 before 10 seconds elapse.
If 0a is operated, the boiling control shown in Fig. 6 will be performed,
When 10 seconds have elapsed, control is returned to initialization.

The boiling control shown in FIG. 6 first initializes, then boils I!
l! The water boiling display LED 82a is turned on, and the water boiling heater relay RL1 is turned on. Subsequently, the water ITa in the tank 5 at the time of starting is detected based on the signal from the water temperature detector 36. Then, the internal clock counts the energization time using the count function until the water temperature rises by 10°C. When the water temperature T reaches To + 10°C, the rate of change in temperature is determined from the starting temperature TO and the counted energization time, and from this rate of change, the water in the tank 5 reaches the current temperature, that is, TO + 10°C, until it boils. The time required for
is calculated, and thereafter the water heater 35 is energized for that t (1 hour). Thereafter, the water heater 35 is energized until this energization time has elapsed or a cancellation operation is performed using the start/cancel switch 80a midway through. When this energization time has elapsed, the heater relay RL1 is warmly turned off, the boiling completion indication LED 82b is turned on, and the boiling water indication LED 82a is turned off.Then, the control is shifted to Fig. 7. If cancellation occurs during the elapse of the energization time, control returns to the initialization process of FIG. 5 described above.

In the energy saving and heat retention control shown in FIG. 7, first, it is checked whether the timer switch 80b and the boiling switch 80G are in the on state.

If the timer switch 80b is on, the control shifts to FIG. 8, and even if the timer switch 80b is off, if the boiling switch 80c is on, the process shifts to 10 seconds as shown in FIG. Move to waiting processing. When the timer switch 80b and the boiling switch 80C are both in the OFF state, it is next checked whether the water temperature in the tank 5 is below 85°C. Then, if the temperature is not below 85℃, the heat retention display LED 82d is lit.
The kettle heater relay RLI is turned off and the heat retention heater relay RL2 is turned on to shift from the boiling operation to the heat retention operation. Furthermore, if the water temperature is below 85°C, it is determined that water has been replenished during the process, and the heater relay RL2 is turned off, the boiling completion display LED 82b is turned off, and the boiling completion display LED 82c is turned on. , and turns on water heater relay RL1. Next, it is sequentially checked whether there is a cancellation using the start/cancellation switch 80a, whether the water temperature in the tank 5 is 96.5°C or higher, whether the timer switch 80b is on, and further whether the boiling switch 80C is on, and then the process is canceled. If the water temperature is 96.5 degrees Celsius or higher, the process returns to the beginning of the process as shown in FIG. 5. If the timer switch 80b is on, the process proceeds to the process shown in FIG. and if the boiling switch 80c is on, the process shifts to the 10 second wait process shown in FIG.
Further, if this switch 80c is off, the process is returned to turning off the thermal insulation heater relay RL2.

The timer setting process shown in FIG. 8 first turns off the water heater relay RL1, then sets the timer time, and within 10 seconds after this setting, the start/cancel switch 8
If the start operation using 0a is not performed, the process will be performed in the fifth step.
If the initialization shown in the figure is restored and the start operation is performed using the start/cancel switch 80a within 10 seconds, the timer setting display L will continue until the set timer time elapses.
Turn off the EDs 82e to 82n one by one. If there is a cancellation operation in the middle of the automatic operation, the process returns to the initialization process shown in FIG. 5, and when the timer setting time has elapsed, the process shifts to the process shown in FIG. 7. The timer switch 80b is turned off when the timer time elapses, and the boiling switch 80c is turned off when boiling control is completed.

In the apparatus according to the embodiment of the present invention configured as described above, if water is poured into the tank 5, the boiling switch 80C is operated, and the start/cancel switch 80a is operated within 10 seconds, boiling ffl is displayed. At the same time, the LED 82a lights up and the water heater relay RLI is turned on to start supplying electricity to the water heater 35. At the same time, the water temperature detector 36 detects the water ITo in the tank 5, and starts counting the energization time. When the water temperature rises by 10 degrees Celsius, the rate of change in water temperature rise is determined from the water temperature Ta at the start and the energization time until the temperature rises by 10 degrees Celsius, and from that change rate, the water heater 3 required to boil the water in the tank 5 is calculated.
Calculate the energization time to to 5. For example, as shown in graph (a) in Figure 9, when the water temperature at star is T2 and the water volume is relatively small, the energization time is tl, and as shown in graph (b), even if the water volume is the same, the starting time is When the water temperature is T1, which is lower than T2, the energization time becomes t2, which is longer than tl, and as shown in the graph (c), even if the water temperature at the start is T2, when the water volume is large, the energization time is longer than tl and t2. It becomes even longer t3. In this way, the energization time from the rate of increase in water temperature to boiling can be determined reliably.

Thus, the water in the tank 5 is reliably raised to the boiling point, and the water in the tank 5 is heated to boiling point. When this time period has elapsed, the water boiler heater relay RL1 is turned off, the electricity supply to the water boiler heater 35 is stopped, and the boiling completion display L
The ED82b lights up and the boiling water display LED82a goes out. After that, the heat-retaining heater relay RL2 is turned on and the heat-retaining operation is performed.

In this way, the time required to energize the water heater 35 to boil the water is calculated from the water temperature at the start and the time required for the water temperature to rise by 10°C, and the water heater 35 is energized according to the calculated energization time. This makes it possible to reliably bring the water in the tank 5 to a boil, and also to ensure that the heater is not energized after boiling, unlike the method that detects the temperature near the boiling point and then stops energizing the heater. can be stopped, improving safety. Further, there is no need for temperature detection control near the boiling point, and the control is simple. Furthermore, since the energization time until boiling is determined based on the rate of change of the actual water temperature rise, the conditions of the ambient temperature and power supply voltage are taken into account, allowing for highly accurate boiling control.

[Effects of the Invention] As detailed above, according to the present invention, it is possible to reliably boil the water in the pot, and it is also possible to reliably stop energizing the water heater after boiling, which improves safety. It can provide a high boiling electric kettle.

[Brief explanation of drawings]

The figures show an embodiment of the present invention; FIG. 1 is an overall sectional view, FIG. 2 is an exploded perspective view of the display section, FIG. 3 is a circuit configuration diagram, and FIGS. 4 to 8 are These are flowcharts showing the control processing of the microcomputer. Fig. 4 is a flowchart showing interrupt processing, Fig. 5 is a flowchart showing main processing, Fig. 6 is a flowchart of boiling processing, and Fig. 7 is a flowchart of normal water boiling and warming processing. , FIG. 8 is a flowchart of the timer setting process, and FIG. 9 is a graph showing the relationship between water temperature rise and energization time. 5...Tank, 35...Kettle heater, 36...
Water temperature detector, 80a...start/cancel switch,
100...Microcomputer, RLl...Kettle heater relay. Applicant's agent Patent attorney Takehiko Suzue Figure 8 Figure 9

Claims (1)

[Claims] A water heater for controlling the water in the pot; a water temperature detector for detecting the temperature of the water in the pot; a start switch for starting water heating control in the pot; and a start switch for starting water heating control in the pot; means (i) for starting energization and at the same time starting detection of the water temperature by the water temperature detector and starting the counting operation of the energization time; energization time calculation means that reads the count energization time, calculates the rate of change in water temperature with respect to time from the starting water temperature, rising temperature, and count energization time, and calculates the time until the water in the pot boils from the rate of change; A boiling type electric pot characterized by being provided with energization control means for controlling energization to the water boiling heater based on the energization time calculated by the energization time calculation means.