JP2725964B2 - Boiling detector for electric rice cooker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiling detector for an electric rice cooker for detecting a boiling state based on a steam temperature.

[0002]

2. Description of the Related Art Conventionally, a rice cooker in which the electric power of a rice cooker is controlled using a microcomputer or the like is disclosed in Japanese Patent Publication No. Sho 63-31.
As disclosed in Japanese Patent No. 204, there is a method in which a boiling element of cooked rice in a container is detected by a heat-sensitive element provided in a lid, and the amount of electric power thereafter is changed. According to this method, even if a small amount of rice is cooked, the rice can be cooked without being spilled because the power is reduced by detecting the boiling.

[0003] Further, if moisture is condensed on the inner lid at the end of rice cooking, water drops will fall on the cooked rice and the taste will be unpleasant. Tar
Control to prevent the formation of dew on the inner lid by raising the temperature of the inner lid by supplying electricity to the inner lid, but the above-mentioned temperature sensing element in the lid accurately detects the boiling of the cooked rice. Figure 4
After detecting the boiling as shown by the symbol, the heater in the lid had to be energized. This is because if the heater in the lid is energized before boiling, as shown in FIG. 5, before the temperature of the temperature-sensitive element rises due to the steam of the cooked food, the heat from the heater causes the temperature-sensitive element to heat up. This is because the temperature rises and boiling cannot be detected.

[0004]

However, by installing a pressure mechanism and the like for making the inside of the pot extremely high pressure,
When the thickness of the inner lid is set to the same thickness as the pressure vessel in terms of safety and strength, the heat capacity of the inner pot increases and the temperature does not become sufficiently high in a short time, so that the cooked rice will boil. Even when the lid heater is energized, the temperature of the inner lid (lid temperature sensor temperature) does not become higher than the temperature of the cooked food (inner pot bottom temperature sensor) as shown in FIG. It was difficult to prevent.

Therefore, the present invention is to provide an electric rice cooker which can detect the boiling of the cooked food by the steam temperature detecting means inside the cover even if the lid heater is energized before the cooked food boils. Is what you do.

[0006]

According to the present invention, there is provided an outer frame, a pot for storing cooked food which is removably provided in the outer frame, and a steam hole for allowing steam in the pot to flow out to the outside. A relatively thick lid for covering the pan, a lid heating means for heating the pan from above in the lid and provided on the inner peripheral side of the lid with respect to the steam hole, and the pan And a pressure device for heating the pot from the bottom, and a pressure device for setting the inside of the pot to a pressure state. With the heating of the pot heating device, the pressure in the pot is increased by the pressure device to cook rice, and the lid heating is performed. The means continuously energizes from the start of rice cooking, detects the boiling of the rice to be cooked, and adjusts the calorific value of the pot heating means, in the vicinity of the steam hole in the lid and on the outer side of the steam hole. Is provided with steam temperature detecting means, and the steam temperature detecting means detects boiling.

[0007]

The steam temperature detecting means for detecting the boiling of the cooked food is located farther from the lid heating means and near the steam hole and on the outer peripheral side of the steam hole, so that the heat of the lid heating means is received. In addition, the lid heating means is made to generate heat from the start of rice cooking, and when steam is generated, the boiling state due to the steam is detected as soon as possible.

[0008]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a boiling detection device for an electric rice cooker according to the present invention. FIG. 2 is a structural diagram of an electric rice cooker on which the boiling detection device of the present invention is mounted.

(1) A pan body, a synthetic resin frame (2), a metal outer frame (3), a synthetic resin bottom plate (4) provided below the outer frame, It has a pan (5) made of a magnetic material (iron or stainless steel) provided so as to be housed inside the outer frame (3) and the bottom plate (4). (6) Pan heating means (hereinafter referred to as a pan heater) comprising an induction heating coil closely attached to the lower surface of the bottom plate (4), and (7) side heating attached to the outer wall of the outer frame (3). A means, (8) a pot temperature sensor penetrating through the center of the bottom plate (4) and closely contacting the outer bottom surface of the pot (5), (9) a coil stand for supporting the pot heater (6), (10) is a ferrite for shielding provided on the lower surface of the coil stand, and (11) is the frame (2).
A choke coil (13) and a radiator plate (14) are mounted on a power supply board arranged in a space (12) below the bottom wall of the ferrite (10) and the ferrite (10). (15) a fan for cooling the heat sink, (16) a control board disposed in a space (17) between the side wall of the frame (2) and the outer frame (3), (1)
Reference numeral 8) denotes a frame cover for fixing the upper portions of the frame (2) and the outer frame (3).

A lid body (19) is pivotally supported on one side to the pan body (1), and the other side is freely engageable with the pan body. The lid body (20), the lower plate (21) and the metal And a relatively thick lid (23) provided below the heat sink and having excellent pressure resistance. (24) is a lid heating means (hereinafter referred to as a lid heater) composed of a linear heater which is mounted on the upper surface of the heat radiator plate (22) in a ring around the center of the heat radiator plate. A steam temperature detecting means (hereinafter referred to as a lid temperature sensor) disposed and fixed between the lower plate (21) and the heat radiating plate (22). The lid heater (24). (26) is an outer packing fitted and fixed to the outer peripheral edge of the heat sink (22), (27) is an inner packing fitted and fixed to the outer peripheral edge of the inner lid (23), (2)
8) Reference numeral 8 denotes a steam hole which opens the upper plate (20) and the radiator plate (22) and communicates with the outside air, and is disposed outside a ring formed by the lid heater (24). (29) is a pressure regulating device provided at the center of the lid (23), which is provided at a lower portion of the hollow valve housing (31) having a plurality of pressure relief holes (30) at a lower portion and the valve housing. Valve seat (33) with pressure hole (32)
And a pressure regulating valve (34) mounted on the upper part of the valve seat and always closing the pressure hole (32). (35) is a safety device provided on the lid (23) and operated when the pot (5) is at a certain pressure or higher to release the pressure in the pan, and (36) is a pressure selector provided on the lid body (19). An operating button (37) and the lid (23) located below the operating button;
When the operating valve is depressed by operating the operation button, the inside of the pot (5) is closed. When the operation button is pressed again, the operating valve rises and the pot (5) is raised. ) And the steam hole (28) are communicated with each other to bring them into a normal pressure state.

[0011] Therefore, when the inside of the pot (5) is closed, pressure cooking is performed, and the cooking time is greatly shortened, so that the cooking is delicious. When the inside of the pot (5) is at normal pressure, normal cooking is performed. Suitable for porridge and cooked rice.

The pressure regulating device (29) and the safety device (35)
And the pressure selection device (36) constitute a pressure device.

The lid temperature sensor (25) has the following structure. (See FIG. 1) (25a) is a temperature-sensitive element whose resistance value changes with temperature,
(25b) is an elastic insulating tube covering the temperature sensing element.
(25c) is a heat collecting aluminum tape wound around the outer circumference of the insulating tube. And an insulating tube (25
b) is crushed and housed in the recess (37) of the lower plate (21) and held by the heat radiating plate (22).

Next, the pressure rice cooking operation will be described. FIG. 3 shows a characteristic diagram of a rice cooking operation by induction heating.

[0015] First, when starting the cooking in terms of the inner bowl (5) in a closed state by the pressure device (b), the microcomputer current having a frequency of 25KH _Z ~40KH _Z by the output of the (not shown) is pot Applied to the heater (6), an eddy current is generated and the entire circumference of the pot (5) generates heat. At the same time, as shown in FIG. 3, the lid heater (24) is also continuously energized, so that the radiator plate (22) and the lid (23) are heated in a short time. As the temperature of the cooked rice rises, the temperature of the space between the radiator plate (22) and the lid (23) and the temperature of the lid temperature sensor (25) also rises.

When the food starts boiling, the steam pressure in the inner pot (5) pushes up the pressure regulating valve (34), and the steam generated from the inner pot (5) is discharged into the pressure hole (32) and the pressure relief hole. Through (30), it begins to flow out of the steam vent (28). This steam heats around the steam holes of the radiator plate (22),
As the temperature rises, the temperature of the lid temperature sensor (25) also rises sharply.

When the temperature of the lid temperature sensor (25) reaches T1 at the point (b), the current flowing through the pot heater (6) is interrupted to maintain the boiling state and shift to the boiling step.

At point (c), when the water in the inner pot (5) disappears and the temperature rises sharply, the pot temperature sensor (8) that senses this temperature inputs the change to the microcomputer and sends the change to the pot heater (6). Then, the power supply to the heater is stopped, and the process proceeds to the spotting process. When the temperature of the pot reaches the heat retaining temperature (about 70 ° C.), the process proceeds to the heat retaining process.

On the other hand, during rice cooking, the steam generated from inside the inner pot (5) touches the lower surface of the lid (23) and contacts the pressure hole (3).
Heading to 2), and during the transition from the end of rice cooking to the warming process (during murara), the temperature in the inner pot decreases, and the steam generated slowly by residual heat or the inside of the inner pot during cooking is filled. The heat generated by the lid heater (24) heats the radiator plate (22) and the lid (23) from the beginning, and the vapor does not condense.

Although the present invention has been described using an induction heating coil as the pan heating means, it may be an ordinary hot plate in which a seed heater is embedded, particularly in a rice cooker using a thick lid. Is valid.

[0021]

As described above, according to the present invention, since the steam temperature detecting means is provided near the steam hole in the lid and on the outer peripheral side of the steam hole, the lid is kept until the cooked rice reaches the boiling point. In addition to reducing the influence of the heat from the lid heating means on the temperature sensor, once the boiling of the cooked food starts, it is possible to detect a rise in the temperature of the radiator plate due to the steam as soon as possible. This makes it possible to energize the lid heating means from the start of cooking of the cooked rice, and even if the lid is as thick as the pressure vessel due to the mounting of the pressure device, the lid must be sufficiently opened before reaching the boiling point. Not only prevents condensation on the lid during cooking, but also supplements the heating of the upper part of the cooked material, which is likely to be insufficient during cooking, with the lid heating means, so there is little unevenness in cooking up and down It will bring about the finished rice.

[Brief description of the drawings]

FIG. 1 is a sectional view of a boiling detection device for an electric rice cooker according to the present invention.

FIG. 2 is a structural drawing of an electric rice cooker in which a boiling detection device is mounted.

FIG. 3 is a characteristic diagram of a rice cooking operation by induction heating.

FIG. 4 is a diagram showing rice cooking characteristics of a conventional electric rice cooker when a lid heater is energized after boiling.

FIG. 5 is a rice cooking characteristic diagram of a conventional electric rice cooker when a lid heater is energized before boiling.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rice cooker main body 3 Outer frame 5 Pot 6 Pot heating means (induction heating coil) 8 Pot temperature sensor 19 Lid body 23 Lid 24 Lid heating means 25 Steam temperature detecting means (Lid temperature sensor) 28 Steam hole

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Daisuke Ikemoto 3-201 Minamiyoshikata, Tottori City, Tottori Prefecture Tottori Sanyo Electric Co., Ltd. (72) Hiroshi Wakaichi 3-201 Minamiyoshikata, Tottori City, Tottori Tori Tori Sanyo Electric Co., Ltd. (72) Inventor Yuji Saito 3-201 Minamiyoshikata, Tottori City, Tottori Prefecture Tottori Sanyo Electric Co., Ltd. (56) References JP-A-2-268710 (JP, A) JP-A-3 −136615 (JP, A)

Claims (1)

(57) [Claims] 1. An outer frame, a pot provided to be detachably inserted into the outer frame to store cooked food, and a steam hole through which steam in the pot flows out to the outside, and the pot is covered. A relatively thick lid,
A lid heating means for heating the pan from above in the lid and provided on the inner peripheral side of the lid with respect to the steam hole, a pan heating means for heating the pan from below, and a pressure state in the pan. consists of a pressure device according to performs cooking by increasing the pressure in the pot by the pressure device with the heating of the pan heating means, said cover heating means is energized continuously from the start cooking, the object to be rice product In the apparatus for detecting the boiling and adjusting the calorific value of the pot heating means, a steam temperature detecting means is provided near the steam hole in the lid and on the outer peripheral side of the steam hole, and the boiling temperature is detected by the steam temperature detecting means. A boiling detection device for a rice cooker.