JPH0412126B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] This invention relates to improvements in boiling type electric pots.

[Technical background of the invention and its problems] Conventional electric pots supply water into the pot and raise the water to a predetermined temperature, for example, 92°C.
When the temperature reached 92 degrees Celsius, the water boiling control was stopped and the system switched to keeping warm mode. For this reason, conventional electric pots have had 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 of a sealed structure, the pressure inside the pot will become 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℃, 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 temperature sensor at high temperatures is required. For example, if the temperature sensor malfunctions and does not detect a point exceeding 100℃, the power supply 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 possible to reliably bring water in a pot to a boil, and also to reliably stop energizing the water heater after boiling. The purpose is to provide a highly safe boiling type electric pot.

[Summary of the Invention] This invention provides a water heater for boiling and controlling water in a pot, a water temperature detector for detecting the temperature of water in the pot, a water amount detector for detecting the amount of water in the pot,
A start switch is provided to start the water heating control in the pot, and when the start switch is turned on, a water amount signal is received from the water temperature detector, and a water amount signal is also taken from the water amount detector, and the water temperature and amount are determined based on the water temperature and water amount. The electricity supply time for the water boiling heater until the water boils is set, and the electricity supply to the water boiling heater is controlled based on this set electricity supply time.

[Embodiments of the Invention] Hereinafter, embodiments of the present invention will be described 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. As shown in FIG. 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 formed in a cylindrical shape with a bottom and forming an inner cylinder of the pot is housed inside the case 1.
This tank 5 has a flange 6 on the periphery of the opening at the upper end, and this flange 6 abuts on the step portion 4 via a packing 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 on the opposite side of the pin 9 so as to be able to move forward and backward. It engages with the joint receiving portion 15. 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. Then, by moving the lock button 13 in the right direction in the figure against the spring 16, the engagement pawl 14 and the engagement receiving portion 1 are engaged.
5 can be released from the engagement.

An inner cover 18 is provided inside the upper cover 8, and an annular groove 19 is formed on the outer peripheral surface of the inner cover 18. A pair of locking bodies 2 are provided on the upper lid 8 facing each other.
0 and 21 are provided, and these locking bodies 20 and 21 engage with the annular groove 19. One locking body 2
0 is fixed to the upper lid 8, but the other locking body 2
1 is supported so that it can move forward and backward. This locking body 21
has an integral 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 and moving the locking body 21 in the right direction in the figure against the spring 23, the engagement between the locking body 21 and the annular groove 19 can be released, and this release allows cleaning, etc. The inner cover 18 can be removed from the upper cover 8 at any time.
A packing 25 is attached to the periphery of the lower end opening of the inner lid 18, and this packing 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 this steam cylinder 24 is exposed flush to the upper surface of the upper lid 8 through the packing 17, and a plurality of passages are formed on this exposed surface. Pores 26... are perforated. A safety valve mechanism 27 is provided inside the steam cylinder 24, and the safety valve mechanism 27 will be described in detail as follows.
A partition plate 28 is attached to the opening at the lower end of the steam cylinder 24, and an opening 29 is formed in the center of the partition plate 28. A valve holder 30 is provided below the partition plate 28, and this valve holder 30 is provided with a truncated conical recess 32 having a tapered surface 31, and is made of rubber or the like formed in a truncated conical shape in the recess 32. A valve body 33 is housed therein. A movable plate 34 is provided on the upper surface of the partition plate 28 to face the opening 29, and this movable plate 34 is pressed downward by the biasing force of the spring 10 and comes into pressure contact with the partition plate 28. It has an escape port 11 constituting a communication portion that communicates the inside with the atmosphere, and this escape port 11 faces the valve body 33 at a distance. Note that 12 is a protective cover that covers the outer periphery of the valve holder 30.

A water 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 and a heat-retaining thermoswitch are installed in the middle.
TRS is installed. 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 obliquely upward and projects to the outside of the front side of the case 1. An opening/closing valve mechanism 38 is provided at the protruding end portion, and the opening/closing valve mechanism 38 will be described in detail.
An operating shaft 40 is inserted into the
First and second valve bodies 41 and 42 made of an elastic material such as rubber are attached to each of the valve bodies 0 . The operating shaft 40 is urged leftward in the figure by a spring 43, and this urging force causes the first and second valve bodies 4 to
1 and 42 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
The second valve body 41 is separated from the peripheral wall of the valve port 39, and then, with a slight delay, the second valve body 42 is separated from the peripheral wall of the valve port 39, and the valve port 39 is opened. Then, when the operating shaft 40 moves to the left in the drawing due to the biasing force of the spring 43, contrary to the above, first the second valve body 42 comes into contact with the peripheral wall of the valve port 39, and then the first
The valve body 41 contacts the peripheral wall of the valve port 39. Therefore, there is no case where only one of the valve bodies 41, 42 comes into contact with the peripheral wall of the valve port 39 and the other does not, and both valve bodies 41, 42 always come into contact with the peripheral wall of the valve port 39. 39 is reliably closed, and even if the second valve body 42, which comes into direct contact with high-temperature water, deteriorates relatively early, the first valve body 41 can prevent the valve port 39 from being closed. Since it can be maintained, there is an advantage that water will not leak from the valve port 39.

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 is provided at a part of the lower end of the inclination.
1 is formed, and a discharge pipe 52 is connected to this discharge port 51. A control component 53 is provided inside the controller case 50, and a large number of lead wires 54 led out from the control component 53 are connected to the controller case 5.
It is drawn out to the outside of the controller case 50 through a packing 55 provided at the lower edge of the controller case 50. The lower end surface of the tank 5 is provided with a terminal 56 through which the heaters 35, 96, water temperature detector 36, and thermoswitch TRS conduct, and the lead wires 54 are connected to this terminal 56. Case 1
A leg body 60 formed in an annular shape is attached to the lower end opening of the housing, a bottom plate 61 is provided inside the leg body 60, and a set screw 62 is screwed from the bottom plate 61 to the controller case 50. By tightening this set screw 62, the flange 6 of the tank 5 is crimped to the packing 7, and the packing 55 through which the lead wires 54 are inserted is compressed, thereby sealing the inside and outside of the controller case 50. .

An overturning switch mechanism 68 is provided on the upper surface of the bottom plate 61, and this overturning switch mechanism 68 is connected to the tapered surface 6.
The base 64 includes a truncated conical recess 63 having a diameter of 3a, a truncated conical weight 65 housed in the recess 63, and a micro switch 69 attached to the upper end surface of the base 64. The micro switch 69 has a push button 66 that protrudes elastically, and the push button 66 opens and closes the energizing circuit for the heaters 35 and 96 by pushing and retracting the push button 66. A movable operation plate 67 is provided on the upper surface of the recess 63, and the push button 66 faces the weight 65 with the operation plate 67 in between.

A transparent water level pipe 70 communicating with the upper and lower ends of the tank 5 is vertically provided on the outside of the side surface of the tank 5.
This water level pipe 70 protrudes to the outside of the front side of the case 1. A decorative panel 71 is attached to the front surface of the case 1, and as shown in FIG. 2, the decorative panel 71 consists of a display section 72 in the upper half and a cover section 73 in the lower half. A vertically elongated measuring window 74 is formed in the display section 72, a transparent measuring cover 74 is attached to the measuring window 74 from the inside with screws 76, and the water level pipe 70 is disposed facing inside the measuring cover 75. By visually observing the water level pipe 70 through the metering window 74 and through the metering cover 75, the tank 5
It is now possible to know the amount of water inside.
Further, an operation board 78 is attached to the inside of the display section 72 with screws 79, and a start/cancel switch 80a, a timer switch 80b, a boiling switch 80c, and each of these switches 80a to 80c are operated on this operation board 78. Operation buttons 81a, 81b, 81c and display elements (LEDs) 82a to 82n that display the control status thereof are arranged in a concentrated manner. And each operation button 8
1a to 81c and display elements 82a to 82n face the front surface of the display section 72 through notch holes 83..., 84... formed in the display section 72. 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 9 is provided inside the tip of this cover part 73.
This pouring button 90 is rotatably supported via a pin 91, is biased clockwise in the figure by a spring 92, and has a protrusion 92 on one side. 93 is opposed to and abuts on the operating shaft 40 of the on-off valve mechanism 38. 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. A pressure sensor 97 is attached to the bottom of the tank 5 to detect the amount of water in the tank 5 based on pressure.

FIG. 3 shows a control circuit for controlling the boiling type electric pot 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), random access memory (RAM), read-only memory (ROM), various I/O ports, a clock signal generator, an A/D conversion circuit, etc. A microcomputer 100 is provided, and connected to the microcomputer 100 is a stabilized power supply circuit 101 which is composed of a power transformer, a full-wave rectifier circuit, a transistor, a resistive element, etc., which are well-known as power supplies. Further, the micro switch 69 and the normally open contact RL1a of the water heater relay RL1 are connected in series to the commercial AC power supply 101a, for example.
The 670W water heater 35 is connected, and a series circuit of the heat retention heater 96 and the thermoswitch TRS is connected via the micro switch 69 and the normally open contact RL2a of the heat retention heater relay RL2 in series. Each of the above relays RL1, RL
2 has one end connected to the positive terminal of the full-wave rectifier circuit in the stabilized power supply circuit 101, and the other end connected to the microcomputer 100, so that its operation is controlled by signals from the microcomputer 100. There is. The water temperature detector 36 includes a Zener diode ZD and resistors R1 to R4.
and a reference voltage circuit 1 consisting of a capacitor C.
02 to the microcomputer 100. The microcomputer 100 is also connected to the start/cancel switch 80 via diodes D1, D2, and D3, respectively.
a, a timer switch 80b and a boiling switch 80c are connected. Further, the display section 72 is connected to the microcomputer 100 via resistors R1 to R9. In this display section 72, each of the display elements 82a to 82n is connected in a matrix circuit, where 82a is an LED for indicating boiling water, and 82b is for indicating boiling completion.
LED, 82c is a normal kettle display LED, 82d is a heat retention display LED, and 82e
~82n is used as a timer setting display LED.
Furthermore, the pressure sensor 97 is connected to the microcomputer 100.

The microcomputer 100 has a power supply 101
When power is turned on and a voltage is output to the stabilized power supply 101, an interrupt is generated at regular intervals according to a command from the CPU, and the interrupt process shown in FIG. 4 is performed. That is, when this process starts, other interrupts are first prohibited. Each time an interrupt occurs, each LED 82a to 82n is set to a predetermined number, e.g.
82a-82d, 82e-82i, 82j-82
They are lit alternately in n groups. this
Following the LED lighting process, the timer function counts. This counting operation is performed by one each time each interrupt is performed. For example, when the boiling switch 80c is operated, the time required to accept the start/cancel switch 80a is 10 seconds, and the time for accepting the start/cancel switch 80a is 10 seconds. It is used to count the energization time to the heater 35, 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 dry cooking is occurring and a dry cooking set flag is set.
Further, if the temperature is lower than 110°C, the states of the start/cancel switch 80a, timer switch 80b, and boiling switch 80c are acquired. If the start/cancel switch 80a is on, it is determined whether this switch 80a was on at the time of the previous interrupt by reading it from the RAM, and if it was on at the previous time, the start/cancel switch 80a is set for the next interrupt. Shifts the count. However, if it was off last time, it will check to see if the electric pot is currently in operation. If the switch is in the operating state, it is determined that this switch operation is a cancellation operation and is 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.
Furthermore, if the previous start/cancel switch 80a is off, then a check is made to see if 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 a fifth
Main control processing shown in FIGS. 8 to 8 is performed. First, in FIG. 5, microcomputer 100 reads the states of start/cancel switch 80a, timer switch 80b, and boiling switch 80c, and issues commands in accordance with the states of these switches. This process first allows interrupts, performs initialization, and checks the empty cooking set flag.
If this flag is set, it is determined that the water is boiling, and each of the LEDs 82a to 82n is flashed, and the water heater relay RL1 is turned off. Here, the dry cooking temperature was set at 110℃ because the temperature at boiling never exceeds 100℃, and we also considered the reliability of operation. When in dry cooking mode, start/cancel switch 8
If the state of 0a is taken and this switch is on, the energy saving and heat retention operation control shown in FIG. 7 is performed. On the other hand, if it is not in the dry cooking state, the state of the timer switch 80b is read. This switch 80
If 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. And start/cancel switch 8
If 0a is on, the control shown in FIG. 7 is performed, 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℃, the control shown in Fig. 7 is performed, and if the water temperature is below 85℃, then the boiling switch 80 is activated.
Take in the state of c. If the switch 80c is off, the process is returned to the initialization described above, and if the switch 80c is on, it is checked whether 10 seconds have passed since the switch 80c was turned on. If the start/cancel switch 80a is operated before 10 seconds have elapsed, the boiling control shown in FIG. 6 will be performed, and if the 10 seconds have elapsed, the control will be returned to initialization.

The boiling control shown in FIG. 6 is first initialized, then the boiling water display LED 82a is turned on, and the water heater relay RL1 is turned on. Subsequently, the water temperature in the tank 5 is detected based on a signal from the water temperature detector 36, and the amount of water in the tank is further detected based on a signal from the pressure sensor 97. Then, the time required for the water in the tank to boil is calculated from the water temperature and water amount, and the calculated time is set as the time for energizing the water heater. Thereafter, the water supply heater 35 continues to be energized until this energization time elapses or unless a cancellation operation is performed using the start/cancellation switch 80a. When the set energization time has elapsed, the water heater relay RL1 is turned off,
The boiling completion display LED 82b is turned on, and the boiling water display LED 82a is turned off. Then control is transferred to FIG. It should be noted that if cancellation occurs during the elapse of the energization time, the control returns to the initialization in the process shown in FIG. 5 described above.

The energy saving and heat retention control shown in FIG. 7 starts with the timer switch 80b and boiling switch 80
Check whether c is turned on. If the timer switch 80b is on, the control shifts to FIG. 8, and even if the timer switch 80b is off, the boiling switch 80
If c is on, the process shifts to the 10 second wait process shown in FIG. 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 will be lit.
The kettle heater relay RL1 is turned off and the heat retention heater relay RL2 is turned on to shift from the boiling operation to the heat retention operation. In addition, if the water temperature is below 85℃, it determines that water has been replenished midway through, and turns off the heat retention heater relay RL2, which indicates the completion of boiling.
Turn off LED 82b, and LED 8 for normal water boiling display.
2c is lit and water heater relay RL1
Turn on. Next, start/cancel switch 8
There is a cancellation due to 0a, or the water temperature in tank 5 is
It sequentially checks whether the water temperature is 96.5°C or higher, whether the timer switch 80b is on, and whether the boiling switch 80c is on, and if there is a cancellation, the process moves to the initialization shown in Figure 5, and the water temperature is 96.5°C. If the timer switch 80b is on, the process goes to the process shown in FIG. 8, and if the boiling switch 80c is on, the process returns to step 5.
The process shifts to the 10-second wait process shown in the figure, and if this switch 80c is off, the process returns to turning off the heat-retaining 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 if the start operation by the start/cancel switch 80a is not performed within 10 seconds after this setting, the process will continue. Return to the initialization shown in Figure 5, and then press the start/cancel switch 8 within 10 seconds.
When the start operation with 0a is performed, the timer setting display is displayed until the set timer time elapses.
Turn off the LEDs 82e to 82n one by one. If there is a cancellation operation during the timer 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.
Note that each timer switch 80b is turned off when the timer time elapses, and the boiling switch 80b is turned off.
0c is turned off when boiling control is completed.

In the apparatus of the present invention constructed in this manner, water is poured into the tank 5 and the boiling switch 8 is turned on.
If you operate 0c and then operate the start/cancel switch 80a within 10 seconds, the boiling water will be displayed.
When the LED 82a lights up, the kettle heater relay RL1 is turned on, and power supply to the kettle heater 35 is started. At the same time, the water temperature in the tank 5 is detected by the water temperature detector 36, and the pressure sensor 9
7 detects the amount of water in the tank 5. Then, the time required for energizing the water heater 35 until the water in the tank 5 boils is calculated from the detected water temperature and water amount. For example, as shown in the graph of FIG. 9, if the water temperature is low at T1 and the amount of water in the tank 5 is large, the energization time required for boiling is long, t3, and as shown in the graph, the water temperature is low at T1. If the amount of water is small, the energization time required for boiling is t.
It is shorter than t3 in case 2 and above A, and furthermore, as shown in graph HA, when the water volume is large but the water temperature is as high as T2, the energization time required for boiling is even shorter than t1 and t2 in case B above. . The time determined by such calculation is the relay for the kettle heater.
RL1 is turned on to energize the water heater 35. 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 kettle heater relay RL1 is turned off to stop supplying electricity to the kettle heater 35, the boiling completion display LED 82b lights up, and the boiling water display LED 82a goes out. After that, the heat-retaining heater relay RL2 is turned on and the heat-retaining operation is performed.

In this way, at the start, the time required to energize the water heater 35 to boil the water is calculated based on the water temperature and amount of water in the tank 5, and the water heater 35 is energized according to the calculated energization time. Because of this, the water in the tank 5 can be reliably brought to a boil, and unlike the system that detects the temperature near the boiling point and then stops the energization to the heater, the water in the tank 5 can be reliably stopped energizing the heater after it has boiled. can be made,
Safety can be improved. Further, there is no need for temperature detection control near the boiling point, and the control is simple.

In the embodiment described above, the setting of the energization time to the heater is determined from the water temperature and the amount of water, but the energization time can be set with higher accuracy by taking into account the ambient temperature, power supply voltage, etc.

[Effects of the Invention] As detailed above, according to the present invention, the water in the pot can be reliably boiled, and the electricity to the water heater can be reliably stopped after boiling, which improves safety. It can provide a high boiling electric pot.

[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 FIG. 4 is a flowchart showing the control process of the microcomputer, FIG. 4 is a flowchart showing interrupt processing, FIG. 5 is a flowchart showing main processing, and FIG. 6 is a flowchart showing boiling processing.
Figure 7 is a flowchart of normal water boiling and warming process, Figure 8
The figure is a flowchart of the timer setting process, and FIG. 9 is a graph showing the relationship between water temperature, water amount, and energization time. 5...Tank, 35...Kettle heater, 36...
...Water temperature detector, 80a...Start/cancel switch, 97...Pressure sensor, 100...Microcomputer, RL1...Kettle heater relay.

Claims (1)

[Claims] 1. A water heater for boiling and controlling the water in the pot, a water temperature detector for detecting the water temperature in the pot, a water amount detector for detecting the amount of water in the pot, and starting the water heating control in the pot. a start switch; when the start switch is turned on, a water temperature signal is taken from the water temperature detector, and a water amount signal is taken from the water amount detector;
energization time setting means for setting the energization time for the water heater until the water in the pot boils based on the water temperature and water amount; A boiling type electric pot characterized by being provided with an energization control means for controlling energization to a heater.