JPH0293Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a boiler having a structure that automatically changes the calorific value of a heater that heats a pot.

[Technical background of the invention and its problems]

Conventional rice cookers, such as electric rice cookers, generally have a heater placed below the pot and use this heater to heat the pot to cook rice. Because the heat source is small compared to other heat sources, there was a problem that it took a long time to cook rice. However, if you try to shorten the cooking time by simply increasing the capacity of the heater in a conventional electric rice cooker, the bottom of the pot will become locally too hot in the latter stages of the rice cooking process, resulting in uneven cooking and scorching. This will cause problems.

By the way, when cooking rice, a large amount of heat is required in the initial stage of cooking until the temperature inside the pot reaches a predetermined temperature (for example, 100℃), and the time required for this initial stage determines the length or shortness of the total rice cooking time. It is known that the amount of heat dissipated is only needed to supplement the amount of heat dissipated in the later stages of rice cooking. In view of this, recently, the heat output of the heater is increased only in the initial stage of rice cooking, and after that, the bottom temperature of the pot detected by a temperature detection device installed thermally at the bottom of the pot reaches a predetermined temperature (the water in the pot starts to boil). It has been considered to shorten the cooking time by configuring the heater to reduce the amount of heat generated when the rice reaches a certain temperature. However, with this type, the temperature detection device is installed on the bottom of the pot for heat transfer, so if you store the pot with water droplets attached to the bottom of the rice cooker, these water droplets will prevent the temperature detection device from detecting the temperature. There is a risk that it will be inaccurate and the intended purpose may not be fully achieved.

[Purpose of invention]

This invention was made in consideration of the above circumstances,
Therefore, its purpose is to reduce the amount of heat generated by the heater when the temperature detected by the temperature detection device reaches a predetermined temperature. To provide a boiler capable of always accurately detecting with a detection device to shorten cooking time and prevent burning.

[Summary of the idea]

The present invention focuses on the fact that an engagement pipe that engages and holds the inner lid is provided on the underside of the lid of the container frame so as to face the inside of the pot. A temperature detection device for detecting temperature is provided, and the heat generation amount of the heater is reduced when the temperature detected by the temperature detection device reaches a predetermined temperature.

In this case, since the temperature detection device detects the air temperature within the pot, the temperature detection accuracy can be improved compared to a conventional device that detects the bottom temperature of the pot. Moreover,
Since the temperature detection device is installed inside the engagement pipe for engaging the inner lid, unlike the case where the temperature detection device is installed in other places, there is a dedicated pipe for holding the temperature detection device. Since holders and the like are not required, the number of parts can be reduced and manufacturing costs can be reduced accordingly.

[Example of idea]

An embodiment in which the present invention is applied to an electric kettle will be described below with reference to the drawings. First, in Fig. 1, 1 is a container frame consisting of an outer frame 2, a bottom frame 3, an inner frame 4, etc., and 5 is a pot housed within the inner frame 4 with a space 6 left between the inner frame 4 and the like. , 7 is a heater arranged in the space 6, which is made up of first and second sheathed wire heaters 8 and 9 arranged concentrically. 10 is container frame 1
This is a heat-sensitive device installed at the bottom of the pot 5 to detect when the cooking is done.This device consists of a heat transfer cap 12 that is urged upward by a spring 11 and is pressed against the outer bottom of the pot 5, and an inner surface of the upper wall of the heat transfer cap 12. This is a well-known structure comprising a magnetic shunt steel 13 fixed to the heat transfer cap 12 and a magnet 14 vertically movably disposed inside the heat transfer cap 12. It can be moved up and down from the outside via the 16 is an operation knob attached to the tip of the lever 15, and 17 is a rice cooking switch that is opened and closed by the lever 15. On the other hand, 18 is a lid placed over the top opening of the container frame 1, and a steam vent pipe 19 is provided on one side of the lid so as to project downward. 20 is a steam vent pipe 1 on the bottom surface of the lid 18.
With the engagement pipe installed on the opposite side from 9,
This is provided so as to protrude into the pot 5, and is made of a material with excellent thermal conductivity, such as aluminum or brass, for example. The engagement pipe 20 and the steam vent pipe 19 are provided with an inner lid 21 for opening and closing the pot 5.
is penetrated and held by engagement. Reference numeral 22 denotes a normally closed type thermal reed switch which is a temperature detection device, and as shown in FIG. The opening is opened when the air temperature inside the pot 5 reaches a predetermined temperature, for example, the temperature at which the water in the pot 5 starts to boil. A filler 23 made of a material with excellent thermal conductivity such as thermally conductive silicone is filled between the thermal reed switch 22 and the engagement pipe 20.

Now, to explain the electrical configuration with reference to FIG. 3, the first sheath wire heater 8 is connected to the rice cooking switch 17
It is connected to the power plug 24 via. On the other hand, the second sheathed wire heater 9 is connected in series with the thermal reed switch 22, and this series circuit is connected in parallel with the first sheathed wire heater 8.
In addition, 25 is a rice cooking lamp, and 26 is a protective resistor.

Next, the operation of the above configuration will be explained. First, after placing rice and water in the pot 5 and setting it in the state shown in FIG. At the same time, the rice cooking switch 17 is held in the on state. In this state, both the first and second sheathed wire heaters 8 and 9 constituting the heater 7 are energized at the same time, and the pot 5 is heated by the heat generated by both the sheathed wire heaters 8 and 9. As a result, the rice and water in the pot 5 are heated strongly and their temperature rises early in the morning, and eventually the steam generated in the pot 5 causes the air temperature in the pot 5 to also rise; It is detected by the thermal reed switch 22 through the engagement pipe 20 and the filler 23. Furthermore, since the engagement pipe 20 and the filler 23 are made of a material with excellent thermal conductivity, the temperature of the air inside the pot 5 cannot be detected by the thermal reed switch 22 even through the engagement pipe 20 and the filler 23. It can't be inaccurate. When the water in the pot 5 starts to boil, the amount of steam generated in the pot 5 rapidly increases, so that the air temperature in the pot 5 rises rapidly. As a result, the temperature detected by the thermal reed switch 22 suddenly reaches a predetermined temperature, the thermal reed switch 22 is turned off, and the second sheathed wire heater 9 of the heaters 7 is cut off. As a result, the point at which the water in the pot 5 starts boiling can be easily and accurately detected, and from then on, the first sheathed wire heater 8
By energizing only the heater 7, the amount of heat generated by the heater 7 is reduced, and rice cooking continues in this state. and,
When the rice cooking is completed and the temperature at the bottom of the pot 5 rises rapidly,
Since the magnetic shunt steel 13 of the heat-sensitive device 10 loses its magnetism, the magnet 14 falls from the magnetic shunt steel 13 and the lever 15 returns to its original position, which turns off the rice cooker switch 17 and turns off the first sheathed wire heater 8. is cut off.

According to the above embodiment, since the thermal reed switch 22 is provided to detect the air temperature inside the pot 5, it can be detected through the air temperature inside the pot 5 that the rice and water in the pot 5 have been heated to a predetermined temperature. Accurate detection is possible at all times. That is, even if rice cooking is started with water droplets adhering to the outer bottom of the pot 5, the thermal reed switch 22 will not be adversely affected by this, and the air temperature inside the pot 5 detected by the thermal reed switch 22 will not be affected. Since the water rises due to the steam filling the pot 5, boiling can be accurately detected regardless of the amount of rice and water in the pot 5. Therefore, if the thermal reed switch 22 is configured to turn off when the water in the pot 5 starts boiling as in this embodiment, the first and second thermal reed switches 22 are turned off until the water in the pot 5 starts boiling. 2 both sheathed wire heaters 8, 9
Because it is possible to simultaneously generate heat and cook rice,
The water in the pot 5 can be raised to the boiling point in a short period of time, which can reliably shorten the cooking time.Moreover, as mentioned above, boiling can be accurately detected by the thermal reed switch 22, so the boiling point can be accurately detected after boiling. The second sheathed wire heater 9 can be reliably powered off to reduce the amount of heat generated by the heater 7, and the rice can be cooked well without burning or uneven cooking. , the power consumption of the heater 7 can also be reduced. In particular, in this embodiment, a thermal reed switch 2 is provided in an engagement pipe 20 that penetrates the inner lid 21 and is held by engagement.
2, there is no need to separately provide a dedicated mechanism for holding the thermal reed switch 22, which simplifies the structure and reduces manufacturing costs.

In the above embodiment, the thermal reed switch 22 is used as the temperature detection device, but the present invention is not limited to this, and other heat-sensitive elements such as a thermistor may be used. Furthermore, the heater 7 does not have to be composed of two sheathed wire heaters 8 and 9, but can be composed of a single heater to reduce the amount of power supplied to the heater when the air temperature in the pot reaches a predetermined temperature. It may also be reduced.

In addition, the present invention can be applied to boilers other than electric pots, and can be implemented with appropriate modifications within the scope of the gist.

[Effect of idea]

As is clear from the above description, the present invention reduces the amount of heat generated by a heater when the temperature detected by the temperature detection device reaches a predetermined temperature. This temperature detection device is installed in the joint pipe for use in the pot and detects the air temperature inside the pot. This allows for accurate detection at all times, which in turn reliably shortens the cooking time and prevents burning,
It has an excellent effect of being able to cook food without causing uneven cooking. Moreover, since the temperature detection device is installed inside the engagement pipe for engaging the inner lid, unlike the case where the temperature detection device is installed in another place, there is no need to hold the temperature detection device. This eliminates the need for a dedicated holder, which reduces the number of parts and reduces manufacturing costs, which is an excellent effect.

[Brief explanation of drawings]

The drawings show an embodiment in which the present invention is applied to an electric kettle, and Fig. 1 is an overall vertical sectional view, Fig. 2 is an enlarged longitudinal sectional view of the main parts, and Fig. 3 is an electric circuit diagram. . In the drawing, 1 is a container frame, 5 is a pot, 7 is a heater, 8 is a first sheathed wire heater, 9 is a second sheathed wire heater, 20 is an engagement pipe, 21 is an inner lid, and 22 is a thermal reed switch. (Temperature detection device), 23 is a filler.

Claims (1)

[Scope of utility model registration request] A pot housed in a container frame, a heater that heats the pot, an engagement pipe protruding from the bottom surface of the lid that opens and closes the top surface of the container frame, and a container that is penetrated by the engagement pipe. An inner lid that is engaged and held, and a temperature detection device provided in the engagement pipe to detect the air temperature in the pot, and when the detected temperature of the temperature detection device reaches a predetermined temperature. A boiler characterized by being configured to reduce the amount of heat generated by the heater.