JP6997500B2 - rice cooker - Google Patents

Description

The present invention is a rice cooker having a rice cooking standby function that automatically starts cooking rice by waiting for the sensing unit that senses the temperature of the rice cooker to cool down from a high temperature state by continuously cooking rice. It is about.

Conventionally, a rice cooker that cooks rice using a temperature sensor has been known. Below the rice cooker, a temperature sensor is provided to detect the temperature of the bottom of the cooker, which is provided so as to be in contact with the flat bottom surface of the cooker. Judging that there is no water left in the kettle, stop heating and start steaming. However, when rice is cooked continuously, the temperature of the temperature sensor itself does not drop sufficiently and the next rice cooking is started at a high temperature, so the temperature of the rice cooker cannot be accurately detected and the rice is cut quickly. There was a variation in the cooked rice from the second time onward.

The cooking apparatus for continuous cooking shown in Document 1 below is provided with cooling means around the temperature sensor in order to solve such a problem, and it is said that rice can be continuously cooked after the temperature sensor drops to a predetermined temperature.

Japanese Unexamined Patent Publication No. 2005-349226

However, the cooking apparatus for continuous cooking described in Patent Document 1 has a configuration in which a pipe for flowing a refrigerant is arranged around the temperature sensor, and dew condensation is formed around the temperature sensor by cooling the temperature sensor with the refrigerant. Causes a problem that the temperature sensor is short-circuited and causes a failure.

The present invention has been made in consideration of such a problem, and as a means for cooling a temperature sensor that has become hot without using a refrigerant, the rice cooker before heating is brought into contact with the rice cooker before heating, and the rice cooker is continuously cooled. In the past, it was not possible to press the rice cooking start button until the temperature sensor cooled down, but if you press the rice cooking start button in advance, it will automatically wait for the temperature sensor to cool down to the specified temperature. The purpose is to provide a rice cooker that can start cooking rice.

In order to solve the above problems, the present invention has the following configurations and means.

The invention according to claim 1 is a rice cooker main body having a heating chamber in which rice is cooked, a rice cooker housed in the heating chamber, a heating means for heating the rice cooker, and a temperature sensor for detecting the temperature of the rice cooker. A rice cooker equipped with a control unit that controls the heating means based on the temperature information of the temperature sensor and an operation unit having a rice cooking start button for inputting the start of rice cooking. The control unit is the rice cooker. By pressing the rice cooking start button, the rice cooking in the rice cooker is automatically started when the temperature of the temperature sensor drops to the temperature at which rice cooking can be started, and the temperature of the temperature sensor is set to a predetermined value. When the temperature drops to the rice cooking startable temperature within the time, the rice cooking in the rice cooker housed in the heating chamber is started, and the temperature of the temperature sensor drops to the rice cooking startable temperature after a predetermined time. Is characterized in that, after changing the heating completion temperature, the rice cooking of the rice cooker housed in the heating chamber is started .

In the invention according to claim 1, unlike forced cooling, cooling cannot be performed in a short time, but if the rice cooker is set and the rice cooking start button is pressed, the temperature sensor is cooled by the newly introduced rice cooker. Since the temperature of the temperature sensor itself waits for the temperature to start cooking and the rice is automatically started, the operator does not have to wait until the temperature of the temperature sensor drops and press the rice cooking start button. Since you are pressing, you can start other work without forgetting to press the rice cooking start button, and if the temperature of the temperature sensor does not drop easily, the heating completion temperature is automatically changed to complete the cooking of rice quickly. It is possible to prevent the rice from being cooked and to obtain a stable cooked rice similar to the first cooked rice.

It is a front view of the rice cooker which concerns on embodiment of this invention. It is a side sectional view of the rice cooker which concerns on embodiment of this invention, (a) shows the state when the door is opened, (b) shows the state when the door is closed. It is a block diagram of the rice cooker which concerns on embodiment of this invention. It is a control flow diagram of the rice cooker which concerns on embodiment of this invention. It is a figure which showed the rice cooking curve at the time of the first rice cooking of the rice cooker which concerns on embodiment of this invention. The rice cooking curve from the completion of the previous rice cooking to the completion of the next rice cooking of the rice cooker according to the embodiment of the present invention is shown, and in (a), the temperature of the temperature sensor drops to the temperature at which the rice cooking can be started within a predetermined time. (Solid line) and the case where the temperature drops to the temperature at which rice cooking can be started over a predetermined time (single-point chain line), and (b) is a partially enlarged view of the rice cooking curve when the heating completion temperature is changed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

As shown in FIGS. 1 and 2, the rice cooker 1 includes a box-shaped rice cooker main body 11 and a heating chamber 4 having a plurality of rectangular shapes in which the inside of the rice cooker main body 11 is divided into one or more in the vertical direction. A door 2 that opens and closes the front opening of each heating chamber 4, a rice cooker 3 that can be taken in and out of the heating chamber 4, a burner 5 that heats the rice cooker 3, and a temperature that senses the temperature of the rice cooker 3. Control that has a sensor 6 and is arranged on the upper part of the rice cooker main body 11 to control the operation of the burner based on the information from the operation unit 7 in which the operator operates the rice cooker 1 and the temperature sensor 6 and the operation unit 7. It is composed of a part 8.

The rice cooker 3 has a bottom surface and a cylindrical shape with an open upper surface, and is housed freely in and out of the heating chamber 4. Near the center of the bottom of the rice cooker 3, a concave portion 31 having a flat recess at a portion where the temperature sensor 6 to be described later comes into contact is provided. The rice cooker 3 may have a rectangular shape that matches the shape of the heating chamber 4.

The temperature sensor 6 has a sensing unit 61 that senses the temperature of the bottom of the rice cooker while contacting the concave portion 31 at the bottom of the rice cooker 3 during rice cooking, and the flame and radiant heat of the burner 5 that covers the periphery of the sensing unit 61. It is provided with a housing 63 for making it less susceptible to the influence of.

The sensing unit 61 is electrically connected to a control unit 8 described later, is arranged so as to be vertically movable in the housing 63, and is always urged upward by a spring 62 provided below the sensing unit 61. Further, the sensing portion 61 has a convex upper and lower two-stage structure, and the upper surface portion abuts on the concave portion 31 of the rice cooking pot 3 to detect the temperature of the bottom of the pot.

The housing 63 forms a cylindrical shape located in the center of the bottom of the heating chamber 4. The housing 63 is composed of four layers made of metal, and is formed of an outer large cylinder 64, a two-layer middle cylinder 65 formed inside the large cylinder 64, and further inside the middle cylinder 65. It is composed of a small cylinder 66. A heat insulating material 67 is sandwiched between the cylinders 64, 65, and 66 to make it difficult for the heat received from the side surface of the housing 63 by the burner 5 in the heating chamber 4 to be transmitted to the central sensing portion 61. .. The opening at the upper end of the small cylinder 66 has a bent portion that is bent inward vertically from the upper edge of the side surface, and the sensing portion 61 located at the upper part of the small cylinder 66 has a convex shape. The portion protrudes upward from the bent portion, and the lower portion does not come out above the bent portion.

Then, when the rice cooker 3 is housed in the heating chamber 4 and the door 2 is closed, the sensing portion 61 comes into contact with the concave portion 31 at the bottom of the kettle as the housing 63 rises, and the sensing portion 61 that can be further lowered is brought into the kettle. The bottom is pushed down. Due to such a structure, the upper surface portion of the sensing portion 61 always keeps in contact with the concave portion 31 of the bottom of the rice cooking pot 3 during rice cooking, and senses the temperature of the bottom of the pot.

Further, the housing 63 moves up and down in the vertical direction in conjunction with the opening and closing of the door 2. The upper surface of the housing 63 when the door 2 is open is positioned so as to be separated downward so as not to come into contact with the bottom of the rice cooker 3 to be taken in and out (see FIG. 2A). When the door 2 is closed, the housing 63 is raised. A state in which the bottom of the rice cooker 3 housed in the heating chamber 4 and the top surface of the housing 63 are in contact with each other by a spring 68 provided below the housing 63, and the bottom of the rice cooker 63 is pushed down. It has become. (See FIG. 2 (b)). The diameter of the concave portion 31 at the bottom of the hook is larger than the diameter of the large cylinder 64 of the housing 63, and the upper surface of the raised housing 63 comes into contact with the concave portion 31. Due to such a structure, the upper surface of the housing 63 is always in contact with the concave portion 31 of the bottom of the rice cooker 3 during rice cooking, the housing 63 surrounds the sensing portion 61, and the sensing portion 61 is the burner 5 during rice cooking. It is designed to be less susceptible to the effects of flames and radiant heat.

The burner 5 mixes the gas supplied from the gas connection port 51 with the air taken in from the intake port 52, and ejects the mixed gas from the donut-shaped burner head 53 to burn the mixture. A temperature sensor 6 is located at the center of the burner head 53. The burner 5 is turned on and off and the thermal power is adjusted by a solenoid valve (not shown) of a gas supply path electrically connected to a control unit 8 described later.

As shown in FIG. 3, the operation unit 7 is provided with a power button 71, a rice cooking start button 72, a cancel button 73, a rice cooking start light 74, and an ignition light 75, and the information input by the operation unit 7 is electrically connected. It is transmitted to the control unit 8.

The control unit 8 executes a heating time and a heating start time suitable for each rice cooking process (preheating step, heating step, boiling maintenance step, steaming step) from a program stored in advance to supply gas to the burner 5. Control. Further, the temperature of each rice cooking process from the start to the completion of rice cooking is controlled based on the temperature sensed by the temperature sensor 6. Further, the rice cooking start time of the rice cooker 3 is controlled based on the temperature sensed by the temperature sensor 6 before the start of rice cooking.

Specific control is shown in the flowchart of FIG. First, when the power button 71 of the operation unit 7 is turned on (step 1) and the rice cooking start button 72 is pressed (step 2), the temperature TS of the temperature sensor becomes the temperature T1 or less at which the rice cooking start is possible after pressing the rice cooking start button 72. The measurement of the time until (hereinafter, standby time W) is started (step 3). Next, it is determined whether the temperature TS of the temperature sensor is equal to or lower than the rice cooking startable temperature T1. If the temperature TS of the temperature sensor is higher than the rice cooking start temperature T1, the next step is not proceeded until the rice cooking start temperature T1 or less is reached. When the temperature TS of the temperature sensor becomes equal to or less than the temperature at which rice cooking can be started T1, the process proceeds to the next step. In the next step, it is determined whether the standby time W measured in step 3 has elapsed the predetermined time. When the standby time W is equal to or less than the predetermined time, the process proceeds to the next step. If the standby time W exceeds a predetermined time, the heating completion temperature T3 that triggers the transition from the boiling maintenance step to the steaming step is changed (step 4), and the process proceeds to the next step. In the next step, gas is supplied and heating of the burner 5 is started (step 5). When the preset rice cooking process is completed, the control unit 8 stops the gas supply, stops the heating of the burner 5, and presses the power button 71 or the cancel button 73 of the operation unit 7 to complete the rice cooking (step 6). When continuously cooking rice using the same heating chamber 4, the process returns to step 1 before pressing the power button 71, and when the rice cooking is completed, the control flow is terminated.

Next, the operation of the rice cooker 1 according to the present invention will be described based on examples.

The rice cooker 1 in this embodiment is a three-dimensional rice cooker provided with a heating chamber 4 stacked in three upper and lower stages on the rice cooker main body 11. A predetermined amount of rice and water are put into the rice cooker 3, the lid is closed, the door 2 that opens the heating chamber 4 at a certain stage is opened, and the rice cooker 3 is accommodated in the heating chamber 4.

When the door 2 is closed, the lowered temperature sensor 6 rises, and the sensing portion 61 and the housing 63 come into contact with the concave portion 31 at the bottom of the rice cooker 3 while constantly receiving the urging force of the springs 62 and 68. ..

First, an example of cooking rice for the first time will be described. Press the power button 71 of the operation unit 7 to turn on the power. When the rice cooking start button 72 of the operation unit 8 is pressed, the rice cooking start light 74 of the operation unit 8 lights up. Since this is the first rice cooking, the temperature TS of the temperature sensor is lower than the rice cooking startable temperature T1 and the standby time W is also a predetermined time or less. Therefore, the control unit 8 immediately supplies gas and starts heating the burner 5. .. When the control unit 7 detects a flame by a flame detecting means (not shown), the ignition lamp 75 lights up, and the operator can know that the flame has ignited the burner and the rice cooking has started.

The control unit 8 starts cooking rice based on the rice cooking process stored in advance. As shown in FIG. 5, in the preheating step, the burner 5 is turned on and off for a predetermined time so as to maintain a temperature at which the rice in the rice cooker 3 can be easily immersed. When rice that has been soaked in advance before cooking is used, the rice cooking process in which the preheating step is omitted may be stored in the control unit 8 and the rice cooking may be started.

After the preheating step, the temperature raising step is started, and heating is continued until the rice and water in the rice cooker 3 reach the boiling temperature. The heating by the burner 5 is continued, and when the temperature TS of the temperature sensor senses the boiling maintenance temperature T2 (for example, 102 ° C.), the temperature raising step is completed and the next boiling maintenance step is started.

In the boiling maintenance step, the control unit 8 heats for a predetermined time so as to maintain the boiling maintenance temperature T2. The water in the rice cooker 3 evaporates and gradually decreases, and when there is almost no water in the bottom of the rice cooker, the temperature of the bottom of the rice cooker rises. The control unit 8 stops heating the burner 5 when the temperature TS of the temperature sensor senses the heating completion temperature T3 (for example, 104 ° C.). The temperature TS of the temperature sensor eventually drops and enters the next steaming step.

In the steaming step, the control unit 8 turns the burner 5 on and off for a predetermined time so as to maintain the steaming temperature. In the steaming step, the steaming may be performed only by the residual heat of the rice cooker 3 and the radiant heat in the heating chamber 4 without heating by the burner 5. When the power button 71 or the cancel button 73 of the operation unit 7 is pressed after completing the above steps, the rice cooking start light 74 is turned off and the first rice cooking is completed.

Next, an embodiment in the case of continuously cooking rice will be described. When the door 2 is opened, the temperature sensor 6 is lowered, and the sensing portion 61 and the housing 63 of the temperature sensor 6 are separated from the concave portion 31 at the bottom of the rice cooker 3 so that the rice cooker 3 can be taken out from the heating chamber 4. Become. The rice cooker 3 that has finished cooking rice is taken out, and the rice cooker 3 that cooks rice next to the rice and water is put into the heating chamber 4 and the door 2 is closed. The operator presses the rice cooking start button 72 after pressing the power button 71 of the operation unit 7.

At this time, the temperature sensor 6 rises and is in contact with the bottom of the pot, but the sensing unit 61 itself of the temperature sensor 6 immediately after the completion of rice cooking receives heat from the bottom of the rice cooker 3 heated at the first time. The temperature TS of the temperature sensor is higher than the temperature at which rice cooking can be started T1 due to the influence thereof, so that the state is in a standby state. From this, when the rice cooking start button 72 is pressed, the rice cooking start light 74 becomes a blinking state indicating a standby state, and the heating of the burner 5 is not started. Then, the heat of the sensing unit 61 itself of the temperature sensor 6 drops quickly due to the rice cooker 3, and when the temperature TS of the temperature sensor drops to the temperature T1 (for example, 60 ° C.) at which rice cooking can be started, the rice cooking start lamp 74 is turned on. The heating of the burner is started.

Therefore, if the operator sets the next rice cooker 3 and presses the rice cooking start button 72, it is necessary to wait for the temperature sensor 6 to drop to the rice cooking start possible temperature T1 and then press the rice cooking start button 72. Since it is gone, you can start other work. During standby, the sensing unit 61 of the temperature sensor 6 is in contact with the rice cooker 3 before heating that has been put into the heating chamber 4, so that when waiting for the sensing unit 61 to cool down without putting the next rice cooker 3 into the heating chamber 4. The cooling of the sensing unit 61 is further promoted as compared with the above.

When the number of times of continuous rice cooking is small from the first time using the same heating chamber 4, even if the housing 63 portion of the temperature sensor 6 is heated, the temperature is not yet relatively high, and the rice is cooked next. The temperature of the sensing portion 61 itself in contact with the concave portion 31 of the bottom of the rice cooker 3 drops relatively quickly to the temperature TS at which rice cooking can be started without being significantly affected by the temperature of the housing 63 portion, and FIG. 6 (a) shows. As shown by the solid line, rice can be cooked normally.

That is, when the temperature TS of the temperature sensor in contact with the bottom surface of the rice cooker 3 drops to the temperature T1 at which rice cooking can be started within a predetermined time, the rice is cooked by the same rice cooking process as the first time. Even if the housing 63 part of the temperature sensor 6 and the entire heating chamber 4 have heat due to the repeated cooking of rice in this way, the heat received on the surface of the cooked rice cooker is charged for the first time. It is carried out until the rice cooking is completed without significantly affecting the temperature change of the bottom of the rice cooker 3 when the rice cooker 3 is heated by the same rice cooking process as above.

However, as the rice is cooked continuously, the sensing unit 61 of the temperature sensor 6 retains high-temperature heat even if the temperature sensor 6 is surrounded by the heat-insulating housing 63. Become affected. In addition, the entire inside of the heating chamber 4 is repeatedly heated to have high temperature heat, and even the surface of the rice cooker 3 put into the heating chamber 3 rises in temperature, so that the sensing unit 61 of the temperature sensor 6 has a temperature rise. Even if it is in contact with the bottom of the pot, the temperature does not easily drop. As a result, the temperature TS of the temperature sensor does not drop to the temperature T1 at which rice cooking can be started within a predetermined time, and even if rice cooking is started as it is, a temperature curve different from the initial rice cooking curve is drawn.

Therefore, even if the rice cooking is started after the temperature TS of the temperature sensor drops to the temperature at which the rice cooking can be started T1, the standby time W becomes long as shown by the one-point chain line in FIG. 6A, and the gas is used in the boiling maintenance step. Not only is it heated in, but the surface of the rice cooker 3 becomes hotter than when the rice is cooked for the first time due to the influence of the heat of the entire heating chamber 4, so that the temperature is maintained higher than the normal boiling maintenance temperature T2. Become. When rice is cooked in such a state, the heating of the burner 5 is stopped in the middle of cooking by reaching the heating completion temperature T3, which is normally judged to be in a state where there is almost no water in the bottom of the pot, in a shorter time than planned, and the control unit In No. 8, water still remains in the kettle and the rice is not sufficiently cooked before entering the steaming process, so that it is not possible to obtain rice with an appropriate finish.

Therefore, when the waiting time W until the temperature TS of the temperature sensor drops to the rice cooking startable temperature T1 elapses for a predetermined time (for example, 2 minutes), the control unit 8 sets the rice cooking completion temperature T3 in advance. The heating is automatically raised to the set heating completion temperature T3.

In the following embodiment, the heating completion temperature T3 is changed from, for example, 104 ° C. to 106 ° C., and then the next cooked rice is started. In the temperature sensor 6 for continuously cooking rice, the housing 63 portion retains heat and becomes high temperature, and the temperature sensor 6 already has heat and becomes high temperature due to radiant heat from the entire heating chamber 4, so that the next rice cooking is performed. Even if the temperature sensor 6 comes into contact with the bottom of the kettle 3, the temperature of the sensing unit 61 does not easily drop, and it takes time for the temperature of the sensing unit 61 to drop to the temperature at which rice cooking can be started T1.

Further, even in the rice cooking pot 3 for starting rice cooking, since the inside of the heating chamber 4 is in a high temperature state, the heating to the surface of the rice cooking pot 3 becomes stronger than when the burner 5 alone is heated, and the temperature only rises quickly. The temperature of the rice cooker 3 at the time of boiling is maintained higher than the boiling maintenance temperature T2.

The temperature TS of the temperature sensor in such a state rises to a higher temperature (for example, 103 ° C.) in a time earlier than the boiling maintenance temperature T2 when the number of initial times and the number of consecutive times is small. Then, when the boiling maintenance step is nearing the end, specifically, as shown in FIG. 6 (b), when the temperature TS of the temperature sensor starts to rise slightly, assuming that the water in the rice cooker 3 starts to run out, heating is performed. If the completion temperature T3 remains at 104 ° C. before the change, the temperature sensor 6 immediately senses the heating completion temperature T3 in a short time (Δt1) while the boiling maintenance temperature T2 rises by 1 ° C. Therefore, the control unit 8 stops the heating of the burner 5 before the water in the rice cooker 3 has sufficiently evaporated, and starts the next steaming step. However, if the heating completion temperature T3 is changed to 106 ° C., the burner 5 continues to heat for a longer period of time (Δt2) until the temperature TS of the temperature sensor rises by 3 ° C., so that the water in the rice cooker 3 is in the meantime. Evaporates, and the water in the rice cooker 3 can be evaporated before entering the next steaming step without the burner 5 being cut off prematurely.

In this way, when cooking rice continuously, even if the temperature TS of the temperature sensor 6 does not easily drop, the rice cooker 3 is put into the heating chamber 4 and the rice cooking start button 72 is pressed to automatically complete the heating. Since the rice cooker 1 starts cooking rice at an appropriate time after changing the temperature T3, it is possible to prevent forgetting to press the rice cooking start button 72. In addition, even if the rice is cooked continuously, the same cooked rice as the first cooked rice can be stably obtained.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and can be appropriately modified without departing from the object of the present invention.

The control unit 8 of the present embodiment uses a gas-type rice cooker, but the present invention is not limited to this, and an electric-type rice cooker using a carbon heater or the like can also exert the same effect.

Further, a safety mechanism is provided in the temperature sensor 6 to allow heating of the burner 25 when the bottom of the rice cooker 3 pushes down the sensing portion 61 and the housing 63 while resisting the urging force of the springs 62 and 68. May be good.

Further, in this embodiment, when the steaming step is completed, the heating of the burner 5 is stopped and the rice cooking step is finished as it is, but a baking step may be added after the steaming step.

In this embodiment, the control unit 8 is configured to automatically start cooking rice after waiting for the temperature TS of the temperature sensor to drop to the temperature at which rice cooking can be started T1, but the temperature sensor is not limited to this. The time at which the temperature TS is predicted to drop to the temperature at which rice cooking can be started T1 may be set in advance, and the cooked rice may be automatically started after the predicted time has elapsed.

1 Rice cooker 11 Rice cooker body 2 Door 3 Rice cooker 31 Concave part 4 Heating chamber 5 Burner 51 Gas connection port 52 Intake port 53 Burner head 6 Temperature sensor 61 Sensing part 62 Spring 63 Housing 64 Large cylinder 65 Medium cylinder 66 Small cylinder Body 67 Insulation material 68 Spring 7 Operation unit 71 Power button 72 Rice cooking start button 73 Cancel button 74 Rice cooking start light 75 Ignition light 8 Control unit TS Temperature sensor temperature T1 Rice cooking start possible temperature T2 Boiling maintenance temperature T3 Heating completion temperature W Standby time

Claims (1)

A rice cooker body with a heating chamber where rice is cooked, a rice cooker housed in the heating chamber, and
A heating means that heats the rice cooker, a temperature sensor that detects the temperature of the cooker, and
A control unit that controls the heating means based on the temperature information of the temperature sensor,
It is a rice cooker equipped with an operation unit having a rice cooking start button for inputting the start of rice cooking.
The control unit
By accommodating the rice cooker in the heating chamber and pressing the rice cooker start button, when the temperature of the temperature sensor drops to the temperature at which rice cooker can be started, the rice cooker is automatically started to cook rice .
When the temperature of the temperature sensor drops to the temperature at which the rice cooking can be started within a predetermined time, the rice cooking in the rice cooking pot housed in the heating chamber is started.
When the temperature of the temperature sensor drops to the temperature at which the rice cooking can be started after a predetermined time has elapsed, the rice cooking in the rice cooker housed in the heating chamber is started after changing the heating completion temperature.
A rice cooker that is characterized by that.

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