JP4989673B2 - Lid packing deterioration detection method and rice cooker using this method - Google Patents

Description

  The present invention relates to a method for detecting deterioration of lid packing that is attached to a lid (inner lid) and seals a pot-like container in a rice cooker that cooks rice and water put in a pot-like container, and rice cooking using this method. It is about a vessel.

  Conventional rice cookers generally have a main body provided with a heating means, a pan, and a lid made of an outer lid and an inner lid. The pan containing rice and water is accommodated in the main body, and the lid I cook with my body closed. The inner lid is provided with a packing made of an elastic material in order to improve the adhesion with the pan and prevent the leakage of steam during cooking, or to ensure the sealing degree when pressurizing ( For example, see Patent Document 1).

Japanese Patent No. 4137892 (page 3-5, Fig. 1-2)

  In the conventional rice cooker as described in Patent Document 1, the packing provided on the inner lid may deteriorate or deform due to repeated use. However, since the user continues to use it until he notices this, for example, in the case of pressure rice cooking, if the sealing degree is low, sufficient pressure cannot be obtained and cooking will be worse, It was difficult for the person to find out the cause.

  The present invention has been made to solve the above-described problems, and can easily and reliably detect deterioration and deformation of the lid packing, and always cook delicious rice by promoting replacement or repair of the lid packing. An object of the present invention is to provide a lid packing deterioration detection method that can be used and a rice cooker using this method.

The lid packing deterioration detection method according to the present invention includes a main body having an open upper surface, a pan-like container in which an object to be heated is placed and housed in the main body, heating means for heating the pan-like container, the heating In the rice cooker having a control part of the means, and an inner lid provided with a lid packing for sealing the pot-like container on the lower surface, and a lid for opening and closing the upper surface opening of the main body part,
The pan side temperature sensor disposed on the outer periphery of the pan-like container detects the temperature drop rate of the pan-like vessel from the end of rice cooking until the lid is opened, and the temperature drop rate is when the time of cooking completion in a normal state of the pre-detected the lid gasket by the side temperature sensor greater than the temperature drop speed of the pan-shaped container until the opening of the lid, the lid gasket deteriorates or deformed It is supposed to be.

  Moreover, the rice cooker which concerns on this invention uses said lid packing deterioration detection method.

  According to the present invention, by measuring the sealing degree of the lid packing that seals the pot-like container, it is possible to reliably detect deterioration and deformation of the lid packing, and inform the user of this and replace or repair the lid packing. Therefore, the user can easily replace or repair the lid packing, and can always cook delicious rice.

It is a longitudinal cross-sectional view of the rice cooker for demonstrating the deterioration detection method of the lid packing which concerns on Embodiment 1 of this invention. It is a drive circuit diagram of the rice cooker of FIG. It is a longitudinal cross-sectional view of the rice cooker for demonstrating the deterioration detection method of the lid packing which concerns on Embodiment 2 of this invention. It is a longitudinal cross-sectional view of the rice cooker for demonstrating the deterioration detection method of the lid packing which concerns on Embodiment 3 of this invention. It is a perspective view of the rice cooker for demonstrating the deterioration detection method of the lid packing which concerns on Embodiment 4 of this invention.

[Embodiment 1]
FIG. 1 is a longitudinal sectional view of a rice cooker for explaining a lid packing deterioration detection method according to Embodiment 1 of the present invention, and FIG. 2 is a drive circuit diagram of the rice cooker of FIG.
In the figure, reference numeral 1 denotes a main body having a bottom and an upper surface opened. Inside, a container cover 2 having a bottom and an upper surface opened and having a flange 2a provided on the outer periphery of the upper end is accommodated. Support portions 2b are projected from, for example, three places on the upper surface of 2a.

  Reference numeral 3 denotes a heating coil for electromagnetic induction heating, which is a heating means provided on the lower surface of the outer wall of the container cover 2, and a first heating coil 3a provided on the bottom outer wall and a second heating coil provided on the outer wall of the corner part. The heating coils 3a and 3b are respectively wound in a spiral shape and connected in series to be supplied with a high-frequency current. Reference numeral 4 denotes a pan bottom temperature sensor that is inserted into a hole provided in the center of the bottom of the container cover 2 and is constantly urged upward by a spring 4a interposed between the main body 1 and the pan.

  Reference numeral 5 denotes a bottomed, open top surface, and a pot-shaped container in which rice and water to be heated are placed and is detachably accommodated in the container cover 2, and a flange 5a is provided on the outer periphery of the upper end. Yes. And when accommodated in the container cover 2, the flange 5a is supported by the support part 2b provided in the flange 2a of the container cover 2, and the bottom part temperature sensor urged by the spring 4a is provided at the bottom center part. 4 contacts.

Reference numeral 10 denotes a lid body comprising an inner lid 11 covering the upper surface opening of the pan-like container 5 and an outer lid 15 to which the inner lid 11 is detachably attached. The lid body 10 is opened and closed by a hinge (not shown). It is connected freely.
On the outer peripheral side of the lower surface of the inner lid 11, there is provided a ring-shaped lid packing 12 made of an elastic material such as rubber, for tightly sealing the inner wall of the pan-like container 5 when the lid 10 is closed. Yes. The inner lid 11 is detachably attached to the outer lid 15 by a locking portion 16, and is in contact with a lid heater built-in portion 13 provided with a heater and having a surface formed of a metal material and provided on the lower surface of the outer lid 15. Condensation is prevented.

  Reference numeral 18 denotes a steam port that penetrates the inner lid 11, the lid heater built-in portion 13, and the outer lid 15 and is detachably disposed in a recess 17 provided in the outer lid 15. An internal steam port 18a and an external steam port 18b that opens to the outside are provided. Reference numeral 19 denotes an operation / display unit provided on the upper surface of the outer lid 15.

  An internal temperature sensor 20 is provided in the outer lid 15, penetrates the lid heater built-in portion 13 and the inner lid 11, is exposed in the pan-like container 5 and detects the temperature in the pan-like container 5, and 21 is the main body 1. And a pan side surface temperature sensor that detects the surface temperature of the pan-like container 5 through the container cover 2 and abuts against the peripheral wall of the pan-like container 5. Although not shown in FIG. 1, the control unit 32 that controls the heating coil 3 and the like by inputting the detected temperature from each of the temperature sensors and the like to the outer lid 15 of the lid 10. 10 (the control unit 32 may be provided in the main body unit 1).

Next, the effect | action of the rice cooker comprised as mentioned above is demonstrated.
First, after putting a predetermined amount of rice in the pot-like container 5, water corresponding to this rice quantity is put in (hereinafter, this rice and water are called heated objects), and then this pot-like container 5 is covered with a container. 2, and the lid 10 is closed. At this time, the lid packing 12 provided on the inner lid 11 is pressed against the inner wall surface or inner wall surface of the pan-like container 5 and the flange 5a for sealing. If the rice cooking switch of the operation / display unit 19 is turned on in this state, rice cooking is started.

  When the rice cooking switch is turned on, a high-frequency current is supplied from the inverter unit 31 to the heating coil 3 to generate a high-frequency magnetic field, the surface facing the heating coil of the pot-shaped container 5 magnetically coupled to the heating coil 3 is excited, and the pot-shaped container 5 An eddy current is induced on the bottom surface of the substrate. Surreal heat is generated by the eddy current and the resistance of the pan-like container 5, and the bottom surface of the pan-like container 5 generates heat to heat the object to be heated.

  For about 20 minutes after the start of rice cooking, the preheating step is a step for maintaining the temperature in the pan-like container 5 at around 60 ° C. The preheating step is a step for promoting water absorption and extracting sweetness. Thereafter, heating is performed with a strong fire, the boiling point of the object to be heated is detected by the pan bottom temperature sensor 4 and the internal temperature sensor 20, and the detection result is input to the control unit 32, and the control unit 32 energizes the heating coil 3. Control. This process of boiling is called a rice cooking process.

  When the water in the pot-like container 5 disappears in the rice cooking process and the temperature of the pot-like container 5 rises rapidly, the pan-bottom temperature sensor 4 that detects this sends the signal to the control unit 32, and the control unit 32 sends the heating coil 3. Stop energizing the. And after cooking for about 15 minutes, the cooking is over. If the temperature of the pan-like container 5 falls to predetermined temperature after completion | finish of rice cooking, the control part 32 will perform the intermittent electricity supply to the heating coil 3 again, and will transfer to a heat retention process.

In the rice cooker configured as described above, in order to detect the deterioration and deformation of the lid packing 12, the rising speed of the side surface temperature of the pan-like container 5 is used.
When the lid packing 12 is deteriorated or deformed, the sealing degree between the pan-like container 5 and the inner lid 11 is lowered, and the outside air enters from a gap, whereby the pan-like container 5 is cooled, and the lid packing 12 is deteriorated. Compared to the case where the pan-like container 5 is not deformed (hereinafter sometimes referred to as a normal state), the temperature rise of the pan-like container 5 is delayed.

  Therefore, the side surface temperature of the pot-like container 5 at the time of rice cooking when the lid packing 12 is in a normal state is measured in advance by the pan side surface temperature sensor 21, and the pattern of the rising speed is stored in the control unit 32 (predetermined value). ) By comparing this rate of temperature rise with the rate of rise of the side surface temperature of the pan-like container 5 measured during rice cooking, it was decided to detect deterioration and deformation of the lid packing 12. In addition, since the rising speed of the side surface temperature of the pot-shaped container 5 varies depending on the amount of the object to be heated and the outside air temperature, the temperature increasing speed pattern based on each condition is stored in the control unit 32 in advance. It is necessary to make a comparison based on the conditions at that time. In addition, the pan side surface temperature sensor 21 is desirably installed at a position higher than the maximum water level in the pan-shaped container 5 in order to make it less susceptible to the heated object of the pan-shaped container 5.

  Further, since the deterioration of the lid packing 12 proceeds gradually, the contact portion between the pan-shaped container 5 and the lid packing 12 gradually decreases when the deterioration of the lid packing 12 proceeds, and the side surface of the pot-shaped container 5 is reduced. Only the temperature of the portion not in contact with the lid packing 12 is lowered. The same can be said in the case of deformation. Therefore, a plurality of pan side surface temperature sensors 21 are provided at the same height position on the outer periphery of the pan-like container 5 at substantially equal intervals, and the pattern of the temperature rise rate of each pan side surface temperature sensor 21 in the normal state of the lid packing 21 is previously set. You may make it memorize | store in the control part 32 and compare this pattern with the temperature rise rate of each pan side surface temperature sensor 21 at the time of rice cooking, and you may make it detect degradation and deformation | transformation of the lid packing 12. FIG.

Further, the temperature lowering rate of the pan-like container 5 during the heat retaining step is detected by the pan side surface temperature sensor 21 and compared with the temperature lowering rate (predetermined value) when the lid packing 12 measured in advance is in a normal state. Deterioration and deformation of the packing 12 may be detected.
When the lid 10 is opened after rice cooking is finished, the temperature of the pan-like container 5 rapidly decreases. Therefore, when detecting the temperature drop rate of the pan-like container 5 during the heat-retaining step, the lid 10 is opened from the end of rice cooking. It is assumed that the temperature drop rate until the temperature is lowered, and the lid 10 is opened by changing the temperature detected by the internal temperature sensor 20 or by a lid opening detection means (not shown) such as a switch provided on the lid 10. ) To detect.

  When the deterioration or deformation of the lid packing 12 is detected according to the present embodiment, it is notified by display or sound by the operation / display unit 19 at the end of cooking and / or at the start of the next cooking. Encourage the replacement of the lid packing 12. As a result, the user can easily know that the decrease in the deliciousness of the cooked rice is due to steam leakage caused by the deterioration and deformation of the lid packing 12, and the repaired parts and replacement parts can be removed. By quickly identifying and repairing, it is possible to always cook delicious rice (the same applies to other embodiments).

  According to the present embodiment, the state of the lid packing 12 that seals the pan-like container 5 is measured in advance in the temperature of the pan-like container 5 during rice cooking and in the normal state of the lid packing 12. Since the deterioration and deformation of the lid packing 12 are surely detected and notified by comparing the temperature with the set temperature (set temperature), the user can easily replace or repair the lid packing 12. Can always cook delicious rice.

[Embodiment 2]
FIG. 3 is a vertical cross-sectional view of a rice cooker for explaining a method for detecting deterioration of lid packing according to Embodiment 2 of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
In the present embodiment, the in-container steam port 18a of the steam port 18 provided in the lid 10 is omitted, and a safety valve 22 protruding into the steam port 18 and a part of the pressure adjusting unit 23 are provided in the inner lid 11. The pressure adjusting unit 23 is controlled by the control unit 32.

  The safety valve 22 has a vent hole 22 a that passes through the inner lid 11 and opens into the steam port 18, and a valve portion 22 b that is located in the steam port 18 and opens and closes the vent hole 22 a. When the pressure is equal to or higher than a predetermined pressure, the valve portion 22b opens and opens and closes the vent hole 22a. This prevents the pressure in the pan-like container 5 from becoming abnormally high.

  Further, the pressure adjusting unit 23 includes a vent 23a that passes through the inner lid 11 and opens into the steam port 18, and a pressure adjusting ball (pressure control valve) 23b that is located in the steam port 18 and opens and closes the vent 23a. The solenoid 23c is provided on the outer lid 15 and controlled by the control unit 32 to slide the pressure adjusting ball 23b in the lateral direction. Then, the adjustment ball 23b is slid in the left-right direction by driving the solenoid 23c, and the pressure in the pan-like container 5 is adjusted by opening and closing the vent hole 23a.

  In the present embodiment, in the rice cooker provided with the pressure adjusting unit 23 as described above, a decrease in the sealing degree of the rice cooker is detected using the fact that the boiling temperature is different between when pressurized and when not pressurized. By doing so, the deterioration and deformation of the lid packing 12 are detected.

  When the lid packing 12 is deteriorated or deformed, the steam in the pan-like container 5 escapes from the gap, so that the steam discharged from the vent hole 23a provided with the adjusting ball 23b is reduced and the pressure can be adjusted. Disappear. At the time of pressurization, when the lid packing 12 is in a normal state, the temperature of the pot-like container 5 at the time of boiling rises due to an increase in boiling point. However, when the lid packing 12 is deteriorated or deformed, the pressure is lowered, so The temperature of the container 5 becomes lower than that in the normal state.

  Therefore, the internal temperature sensor 20 detects in advance the boiling temperature of the contents of the lid packing 12 in a normal state and stores it in the control unit 32 (predetermined value), and the pan bottom temperature sensor 4 and pan side surface temperature sensor 21. The temperature of the pot-like container 5 at the time of boiling is detected by both or any of the above, and when the temperature of the pot-like container 5 is lower than that in the normal state, the lid packing 12 is deteriorated or deformed. It is intended to detect that.

In the present embodiment, the lid 10 is provided with an internal pressure sensor 24 that penetrates the inner lid 11 and is exposed in the pan-like container 5.
As described above, when the lid packing 12 is deteriorated or deformed, the pressure in the pan-like container 5 does not increase. Therefore, after the internal temperature sensor 20 detects boiling, the internal pressure sensor is detected after a certain time. The pressure in the pot-shaped container 5 is detected by 24, and when this is close to the atmospheric pressure, it can be detected that the lid packing 12 is abnormal.

  In this case, since the timing at which the pressure in the pan-like container 5 starts to rise differs depending on the amount of the object to be heated, the amount of the object to be heated is detected before the preheating step or the boiling step, and after detecting the boiling, It is desirable to detect the pressure in the pan-like container 5 by the internal pressure sensor 24 when the time corresponding to the amount of the heated object has elapsed.

[Embodiment 3]
FIG. 4 is a vertical cross-sectional view of a rice cooker for explaining a lid packing deterioration detection method according to Embodiment 3 of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
In the present embodiment, when the pan-like container 5 is accommodated in the container cover 2 at the bottom of the container cover 2, a vibration generating unit 25 that comes into contact with the bottom is provided, and on the upper surface of the flange 2 a of the container cover 2. A vibration sensor 26 is provided.

  When vibration is applied to the pot-shaped container 5 that is accommodated in the container cover 2 and the lid 10 is closed, for example, the lid packing 12 made of an elastic material such as rubber adheres to the pot-shaped container 5 in a normal state. However, if the lid packing 12 is deteriorated or deformed, the contact area with the pan-like container 5 is reduced, so that the degree of vibration attenuation is reduced. In other words, the vibration of the pan-like container 5 becomes larger than when the lid packing 12 is normal.

  The present embodiment utilizes the above phenomenon, and the vibration generating unit 25 applies vibration to the pan-like container 5, and the vibration sensor 26 detects this to compare with the case where the lid packing 12 is in a normal state. The deterioration and deformation of the lid packing 12 are detected based on the vibration attenuation degree. Since the degree of vibration attenuation varies depending on the amount of the object to be heated in the pan-like container 5, each object to be heated in the normal state of the lid packing 12 detected by the weight of the object to be heated and stored in the control unit 32. It is desirable to compare with vibration damping data for each quantity.

[Embodiment 4]
FIG. 5 is a perspective view of a rice cooker for explaining a lid packing deterioration detection method according to Embodiment 4 of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
A humidity sensor 27 is installed on the outer periphery of the lower surface of the upper lid 15 of the lid body 10 so as to cover the entire outer circumference of the flange 5a of the pan-like container 5 when the lid body 10 is closed. In order to prevent the ingress of water and to make it easy to eliminate when the water has infiltrated, it is provided downward.

When the lid packing 12 provided on the inner lid 11 deteriorates or deforms, steam is released from the gap between the lid packing 12 and the pot-like container 5, thereby increasing the humidity near the outer periphery of the flange 5 a of the pot-like container 5. To do.
The present embodiment utilizes such a phenomenon, and the humidity detection value by the humidity sensor 27 is stored in the control unit 32 before and after the contents of the pan-like container 5 boil. When the value is equal to or greater than the value in the normal state, the lid packing 12 is detected to be deteriorated or deformed. In addition, although the case where the humidity sensor 27 was provided in the perimeter of the cover body 10 was shown, you may provide it in a part.

[Embodiment 5]
This Embodiment is related with the rice cooker provided with the deterioration detection method of the lid packing which concerns on any of Embodiment 1-4.
According to the present embodiment, it is possible to easily and surely detect deterioration and deformation of the lid packing 12 provided on the lid 10 and sealing the opening of the pan-like container 5, and repair or exchange can be performed. You can always cook delicious rice.

  In the above description, the case of performing the lid packing deterioration detection method according to the present invention on the illustrated rice cooker has been shown, but the present invention is not limited to this, and the lid packing deterioration is also applied to rice cookers of other structures. A detection method can be implemented.

  DESCRIPTION OF SYMBOLS 1 Main body part, 2 Container cover, 3 Heating coil, 4 Pan bottom temperature sensor, 5 Pan-shaped container, 5a Flange, 10 Lid body, 11 Inner lid, 12 Lid packing, 15 Outer lid, 18 Steam port, 19 Operation / display part , 20 Internal temperature sensor, 21 Pan side surface temperature sensor, 22 Safety valve, 23 Pressure regulator, 24 Internal pressure sensor, 25 Vibration generator, 26 Vibration sensor, 27 Humidity sensor.

Claims (4)

A main body having an open upper surface, a pan-like container in which an object to be heated is placed and accommodated in the main body, a heating means for heating the pan-like container, a control unit for the heating means, and the pan-like container on the lower surface In a rice cooker having an inner lid provided with a lid packing for sealing, and having a lid for opening and closing the upper surface opening of the main body,
The pan side temperature sensor disposed on the outer periphery of the pan-like container detects the temperature drop rate of the pan-like vessel from the end of rice cooking until the lid is opened, and the temperature drop rate is when the time of cooking completion in a normal state of the pre-detected the lid gasket by the side temperature sensor greater than the temperature drop speed of the pan-shaped container until the opening of the lid, the lid gasket deteriorates or deformed A method for detecting deterioration of lid packing, characterized in that: The pan side temperature sensor deterioration detecting method of the lid gasket according to claim 1, characterized in that the plurality disposed at substantially equal intervals at the same height on the outer circumference of the pot-shaped container. A rice cooker using the lid packing deterioration detection method according to claim 1 or 2 . When the deterioration or deformation of the lid packing is detected by the lid packing deterioration detection method, a signal that prompts replacement or repair of the lid packing is generated at the end of cooking and / or before the next cooking. The rice cooker of Claim 3 characterized by the above-mentioned.

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