KR840002274Y1 - Electric rice cooker - Google Patents

Abstract

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Description

electric rice cooker

The drawings show each embodiment of the present invention,

1 is a longitudinal sectional view of the first embodiment.

2 is an electrical circuit diagram of the embodiment.

3 is a temperature characteristic curve diagram of the embodiment.

4 is a longitudinal sectional view of the second embodiment;

5 is an electric circuit diagram of the embodiment.

6 and 7 are electrical circuit diagrams of the third and fourth embodiments, respectively.

The present invention relates to an electric rice cooker with an improved heating method by an electric heater.

In general, in order to cook the most delicious rice, cooking rice cookers, etc., at the beginning of cooking, with a low heat, and then with a strong fire, then the water in the rice cooker disappears, which is roughly dry It is well known that heating on low heat is ideal.

However, in a conventional electric rice cooker, that is, an electric heater for heating the rice cooker, and an electric rice cooker having a temperature switch for sensing the temperature of the bottom of the rice cooker and controlling the energization of the electric heater, one electric heater is provided. Since the heat is generated by the same amount of heat from the beginning of cooking until the rice cooker is in the dry-up state, and after the dry-up, the above-mentioned electric heater is cut off, and thus the rice cannot be cooked as described above.

The present invention focuses on the above-mentioned conventional problems, and an object thereof is to provide an electric rice cooker which can cook rice most ideally.

Next, the present invention will be described with reference to the drawings for each embodiment applied to the radiant heating type electric rice cooker. First, the first embodiment will be described according to FIGS. That is, in FIG. 1, (1) is a bottomed cylindrical outer frame which is provided with a substantially cylindrical inner frame 3 with a heat insulating material 2 interposed therebetween. The inner frame 3 is formed of a material such as aluminum having good thermal conductivity and is subjected to surface treatment such as chemical polishing in order to increase the heat reflectivity. An annular frame 4 is provided at the periphery of the upper opening. The rice cooker 5 detachably attached to the inner frame 3 is held at the predetermined position shown by bringing the flange 6 formed around the upper end opening into contact with the upper edge of the inner frame 3, and in this state, Each circumferential wall of the rice cooker 5 and the inner frame 3 opposes each other with an extremely small space therebetween, and each bottom wall opposes each other with a space 7 of a predetermined interval therebetween.

The outer lid 8 covering the upper opening of the outer frame 1 is, for example, a plastic material and is rotatably supported by the outer frame 1 with the hinge member 9 interposed therebetween, and integrally thereon. It has a handle 10 formed as. In addition, the outer frame 1 and the outer lid 8 are provided with a coupling member 11 opposite to the hinge member 9 so that the outer lid 8 can be held in the closed position and pressed. The member 12 is comprised so that the engagement can be released. The inner lid 14 is provided on the inner surface of the outer lid 8 with the support member 13 interposed therebetween. The inner lid 14 is configured such that the peripheral edge thereof comes into close contact with the peripheral edge of the upper opening of the rice cooker 5 when the outer lid 8 is in the closed position. The steam discharge container 15 is provided with the bowl valve 16 which can be opened and closed according to the difference between the internal pressure and the external pressure of the rice cooker 5. In the inner bottom of the outer frame 1, a little space is formed between the bottom of the inner frame 3, and on the lower side of the outer frame 1, the operation member 17a of the first temperature switch 17 ) Is installed to partially protrude outside the outer frame (1).

The operation member 17a is connected to the holding member 17c with the lever 17b interposed therebetween. The holding member 17c is, for example, a permanent magnet, and has a magnetic material 17d that loses its magnetic properties at the point of change of shape by manual operation of the first temperature switch 17. ) Is adsorbed against the repulsive force of the coil spring 17e. The sperm material 17d has a property in which the magnetic permeability rapidly decreases when the predetermined temperature T ₁ (for example, 310 ° C.) is reached. Accordingly, the first temperature switch 17 releases the magnetic adsorption between the holding member 17c and the sperm material 17d at the predetermined temperature T ₁ , and the microswitch 18 to be described later is removed from the first position. It is configured to switch to 2 positions.

On the other hand, in the space portion 7, the first electric heater 19 and the second electric heater 20, which are substantially annular, are provided as cooking heaters, and the outer peripheral portion of the inner frame 3 is in contact with this. An approximately annular third electric heater 21 is provided as part of the heat keeping heater. These first, second and third electric heaters 19, 20 and 21 are for example a size heater, of which the first and second electric heaters 19 and 20 are respectively The same rated output of 300 watts is used. Then, the bimetal-type second temperature switch 22 is installed above the outer periphery of the inner frame 3 so as to sense the temperature of the inner frame 3, which is energized only when the detection temperature exceeds, for example, 90 ° C. It is a configuration. Here, the second temperature switch 22 and the micro switch 18 correspond to the automatic switching means of the present invention.

Next, the configuration of the electric circuit will be described with reference to FIG. That is, the micro switch 18 is of a two-circuit switching type, and is switched between the contacts c _{1-a 1} and the contacts (when switched to the first position by the operation of the operation member 17a shown in FIG. ₁ ). c ₂ -a ₂ ) are connected, and when switched to the second position, between the contacts c _1- b ₁ and between the contacts c _2- b ₂ . The second circuit is connected between the terminals c _{1-a 1} of the micro switch 18 and the series circuit of the first electric heater 19 between both terminals of the power supply plug 23. heater (20), is brought into contact with a series circuit between the contact points (c ₁ -a ₁₎ of the second temperature switch 22 and micro switch 18 in parallel with the electric heater 19 of the first. In the micro switch 18, the fixed contact b ₂ is kept open from the electric circuit and the fixed contact b ₁ and the movable contact c ₂ are connected to each other. In addition it was connected to a series circuit of said third electric heater 21 and the configuration of the third temperature switch 24 for thermal insulation of a known parallel and between the contact points (c ₁ -a ₁₎ of the microswitch (18) .

Next, the operation of this embodiment of the above configuration will be described with reference to FIG. In FIG. 3, the cooking time T is indicated on the horizontal axis, the bottom temperature D of the rice cooker 5 is displayed on the vertical axis, the temperature characteristic curve of the embodiment is indicated by a solid line, and the temperature characteristic curve of the conventional configuration is dotted. Indicated by. First, a predetermined amount of rice and water according to the amount is put in the rice cooker (5) and placed in the inner frame (3), the outer lid (8) and the inner lid (14) in a closed state, and then the potential plug (23). Plug into the power outlet.

Next, by pressing the operating member 17a downward, the micro switch 18 of the first temperature switch 17 is switched to the first position, and between each contact c _{1-a 1} and (c _{2-a 2} ). Connect between. At this time, since the second temperature switch 22 which detects this when the temperature of the inner frame 3 is 90 ° C. or lower is opened, only the first electric heater 19 is the contact point c of the micro switch 18. _{1-a 1} ) is energized and heats up to a rated output of 300 watts, thereby starting cooking. Therefore, the temperature of the rice cooker 5 rises relatively slowly. When the temperature of the cooker 5 rises at the same time as the temperature of the rice cooker rises above 60 ° C., the temperature of the inner frame 3 (particularly, the temperature of the second temperature switch 22 attachment part) precedes the temperature of the rice cooker. The second temperature switch 22 is connected to a temperature exceeding 90 ° C., whereby the first electric heater 19 and the second electric heater 20 are connected to the power supply plug 23 (that is, the power supply). The first and second electric heaters 19 and 20 are both energized and heated, and as a result, the rice cooker 5 is heated to twice the heating capacity (600 watts) so far. do. In this manner, when the temperature of the rice cooker 5 reaches 100 ° C., the water inside is boiled, and the bottom temperature of the rice cooker is maintained at about 100 ° C. while water remains in the rice cooker 5 in this state.

Thereafter, when the water in the rice cooker 5 disappears and this represents a so-called dry-up state, the temperature of the bottom of the rice cooker 5 rises rapidly, and at the same time, the sperm material 17d also causes a rapid temperature rise. Then, when the temperature of the sperm material 17d reaches a predetermined temperature T ₁ (130 ° C.), the permeability is sharply lowered, so that the holding member 17c releases the adsorption of the sperm material 17d and the coil spring. It is moved downward by the repulsive force of 17e, and the micro switch 18 is switched from the first position to the second position so as to be connected between the respective contacts c _1- b ₁ and between (c _2- b ₂ ). do. As a result, since the first and second electric heaters 19 and 20 are connected in series with respect to the power supply plug 23 through the contacts c _1- b ₁ , as a result, each electric heater The power consumptions of (19) and (20) are 1/4 as compared with the case of energizing in the parallel connection state described above.

Therefore, the cooker 5 is heated to a heat generation capacity (150 watts) of 1/4 so far. After that, when the cooker bottom temperature becomes approximately 90 ° C. or less, the temperature of the inner frame 3 is also approximately 90 ° C. or less, approximately following this, so that the second temperature switch 22 is opened, and thus the first and second electric The heaters 19 and 20 are cut off to complete the cooking. After this, the third electric heater 21 and the first electric heater 19 are serially and intermittently energized by the action of the third temperature switch 24 for thermal insulation, so that the rice cooker 5 is kept warm. Maintain the temperature.

According to the above structure, the rice cooker 5 is heated by the comparatively small heat generating capacity (300 watts) only by the 1st electric heater 1 in the beginning of cooking, and is connected in parallel with the power supply in the cooking medium. And the first and second electric heaters 19 which are heated by the second electric heaters 19 and 20 to a large heat generating capacity (600 watts), and are connected in series to the power source in the latter periods of cooking. And because it is configured to heat the heat generating capacity (150 watts) by the (20), it is possible to heat the cooker 5 in an ideal temperature change state suitable for a generally known delicious cooking method. In particular, according to this embodiment, since the first and second electric heaters 19 and 20 are rated at 300 watts, respectively, the current density per one of each of the electric heaters 19 and 20 can be reduced. Therefore, even in the case where the electric heaters 19 and 20 are constituted as sheath heaters as in the present embodiment, it is not necessary to use expensive materials having high heat resistance at their outer shells and can be manufactured at low cost as a whole.

4 and 5 show a second embodiment of the present invention, which will be described only in the parts different from the first embodiment. That is, in this embodiment, the micro switch 25 of the single switch type is provided in place of the micro switch 18 of the second switch type in the first embodiment, and at the same time, the outer bottom of the inner frame 3 is provided. A bimetal type temperature switch 26 is provided on the surface to sense the temperature of the inner frame 3, and the first and second electric heaters 19 having a rated output of 300 watts, respectively, in the first embodiment. And instead of (20) a first electric heater 27 of rated output, eg 350 watts and a second electric heater 28 of rated output, eg 650 watts, and the electrical circuit of FIG. It is configured as shown in. In addition, the micro switch 25 in this embodiment connects between the contacts ca when switched to the first position by the operation of the operating member 17a, and contacts cb when switched to the second position. The temperature switch 26 has a normal open contact 26a and a normal closed contact 26b, and the normal open contact 26a has a detection temperature exceeding, for example, 60 ° C. It connects as a ratio and the normal closed contact 26b is a structure opened only when the detection temperature exceeds 110 degreeC, for example. The micro switch 25 and the temperature switch 26 correspond to the automatic switching means of the present invention.

According to the second embodiment of the above arrangement, in the beginning of cooking, only the first electric heater 27 generates heat at a rated output of 350 watts, and then the cooker bottom temperature exceeds 60 ° C, whereby the normal open contact 26a is connected. At this time, the second electric heater 28 is also energized. Therefore, in the middle of cooking, the first and second electric heaters 27 and 28 generate heat to a total of 1000 watts, and then in the rice cooker 5 again. When the cooker bottom temperature exceeds 110 ° C, the normal closed contact 26b is opened, and only the second electric heater 28 comes to generate heat at the rated output of 650 watts during the cooking period. Therefore, also in the second embodiment, the rice cooker 5 can be heated in an ideal state suitable for the method of making delicious rice, as in the first embodiment.

The present invention is not limited to each of the above embodiments. For example, the present invention is configured as in the third embodiment shown in FIG. 6 by changing the configuration of the electric circuit of the second embodiment, or the second embodiment. The first electric heater 29 having a rated output of 1000 watts, respectively, as shown in FIG. 7 in place of the first electric heater 27 of the rated output 350 watts and the second electric heater 28 of 650 watts in the example. And a second electric heater 30, and each of these electric heaters 29 and 30 connected together with the micro switch 25, the temperature switch 26, etc. as shown in FIG. You may comprise like an Example.

In addition, the present invention is not limited to each of the above-described embodiments. For example, a timer or a microcomputer may be used as the automatic switching means, and various modifications can be made without departing from the scope thereof.

According to the present invention, as understood from the above description, in an electric rice cooker for cooking by a rice cooker, the first electric heater and the second electric heater for heating the rice cooker are provided, and these first and first An automatic switching means for connecting the electric heater of 2 to one side of the power source in accordance with the progress of cooking, or in series or parallel to this power source is provided, and the automatic switching means reduces the total output of the heater in the early stage of cooking. And the temperature control so as to be larger in the middle of cooking and smaller than that of the above in the middle of cooking, thereby making rice ideally cooked and making it the most delicious rice.

Claims (1)

While installing the first electric heater 19 and the second electric heater 20 for rice cooker heating of the electric rice cooker, only one side of the first and second electric heaters is supplied to the power source as the cooking proceeds. Automatic switching means for connecting or connecting in series or parallel to this power supply is provided, and the automatic switching means enables the total heater output to be small in the early stage of cooking, large in the middle of cooking, and the above-mentioned cooking in the later stage of cooking. Electric rice cooker characterized in that it is controlled to be smaller than that of the medium.