JP2012187173A - Rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that although the establishment of a steam superheater and safety device has been considered for the stabilization of steam temperatures and a further increase in steam temperature to deal with the problem that a surface of rice gets dry, a difference between a temperature increase in the steam superheater and that of the safety device is large so that it is difficult to set a temperature at which the safety device operates without fail in the case of abnormality while having a sufficient temperature allowance in regular or continuous use.SOLUTION: The rice cooker includes temperature detection-type safety devices 45a, 45b for securing the safety of a steam superheater 15. A certain clearance L is provided between the safety devices and the steam superheater, which allows the safety devices to have a sufficient temperature allowance in regular or continuous use and also to operate without fail in the case of abnormality, thus securing the safety of the steam superheater.

Description

  The present invention relates to a rice cooker using superheated steam, and particularly to improvement of rice cooking performance.

  In a general household rice cooker, a pot heating means for heating rice and water in the pot arranged at the bottom of the pot is the main heating means. In order to cook rice deliciously, it is important to fully gelatinize the starch of rice. In particular, starch is gelatinized by heating rice at a high temperature during additional cooking, and the sweetness and aroma of rice are increased. However, since there was almost no water at the time of additional cooking, if the additional heating by the pot heating means was continued, the rice near the bottom of the pot would be burnt, so the heating had to be weakened.

  For example, as shown in FIG. 8, there is a rice cooker that heats cooked rice and water by injecting hot steam into the pan from above the pan in addition to heating by the pan heating means (see, for example, Patent Document 1).

  FIG. 8 shows a conventional rice cooker described in Patent Document 1. As shown in FIG. In FIG. 8, 51 is a rice cooker body, 52 is a pan detachably mounted on the rice cooker body 51, and 53 is a lid that covers the top surface of the pan 52 so as to be freely opened and closed. Reference numeral 54 denotes a pot heating means for heating the pot. Reference numeral 55 denotes a steam generating means built in the main body 51, and has a water tank 56 and a water tank heating means 57. The water in the water tank 56 is heated by the water tank heating means 57 and boils. The water vapor generated in the water tank 56 is supplied to the pan 52 from the steam hole 59 through the steam pipe 58. As described above, steaming high temperature steam in the pan 52 is supplied immediately after finishing without promoting the upper layer rice to promote gelatinization, so that the taste of rice is improved throughout the pan. Can do.

JP 2003-144308 A

  However, in the structure of the conventional rice cooker, in order to promote the gelatinization of rice, the water tank and the water tank heating means are provided separately from the pan, and the steam generated in the water tank is overheated to 100 ° C. or higher. Since the rice cooker thrown into the inside has a problem that the surface of the rice is dried if the temperature is raised too much in order to stabilize the steam temperature and further raise the steam temperature, it is conceivable to provide a steam heating means. In order to ensure the safety of this steam overheating means, it is conceivable to further provide a temperature detection type safety device, but there are many menus for rice cooking, and steam temperature is set according to the menu. If the temperature variation of the superheater is large, and the rice is continuously cooked, etc., the second and subsequent rice cooking will be carried out while the temperature of the steam superheater is high. However, it was difficult to set the temperature so that a sufficient temperature margin of the safety device was ensured during normal use and continuous use, and the safety device operated in an abnormal state.

  The present invention provides a temperature detection type safety device to ensure the safety of the steam heating means, and further provides a certain clearance between the safety device and the steam superheating means, so that the temperature of the safety device can be maintained even during normal use and continuous use. An object of the present invention is to provide a rice cooker that can secure a sufficient margin and that ensures the safety of steam superheating means by adopting a configuration in which a safety device operates in an abnormal state.

  In order to solve the conventional problems, a rice cooker according to the present invention covers a rice cooker body having an open upper surface, a pan detachably accommodated in the rice cooker body, and a rice cooker body that can be opened and closed. A lid, heating means for heating the pan, steam generating means for generating steam, steam superheating means for increasing the temperature of steam generated from the steam generating means, and for preventing abnormal temperature rise of the steam superheating means. It has a safety device, and the safety device is installed with a certain gap from the steam superheating means.

  As a result, the safety device detects the ambient temperature of the steam superheating means, so it is not directly affected by variations in the temperature of the steam superheating means during normal use of various menus and can be reduced. The temperature point at which the safety device operates only when an abnormal heating state occurs can be set, and the safety of the steam overheating means can be ensured.

  In the rice cooker of the present invention, since the steam superheating means and the safety device are installed with a certain distance, the temperature of the steam superheating means is not directly detected by many menus in normal use, and the atmosphere of the steam superheating means Since the temperature is detected, the temperature of the safety device can be stabilized, and even if it is used continuously, the temperature difference in the atmosphere is smaller than the temperature of the steam superheating means. The temperature of the safety device can be stabilized, and by ensuring a sufficient difference between the operating temperature in the abnormal state of the safety device and the detected temperature in the normal abnormal state, the operating accuracy of the safety device can be improved in the abnormal state. Therefore, it is possible to use superheated steam having a higher temperature for cooking rice while ensuring the safety of the steam superheating means.

Schematic sectional view of a rice cooker in Embodiment 1 of the present invention. Top view of rice cooker in Embodiment 1 of the present invention The principal part perspective view of the rice cooker in Embodiment 1 of this invention. Sectional drawing of the principal part of the rice cooker in Embodiment 1 of this invention. Sectional drawing of the principal part of the rice cooker in Embodiment 1 of this invention. Sectional drawing of the principal part of the rice cooker in Embodiment 1 of this invention. The characteristic figure of the rice cooker in Embodiment 1 of this invention Sectional drawing which shows the conventional rice cooker

  1st invention is the rice cooker main body which the upper surface opened, the pan accommodated in the said rice cooker main body detachably, the lid | cover which covers the said rice cooker main body openably, and the heating means which heats the said pan. Steam generating means for generating steam, steam superheating means for increasing the temperature of the steam generated from the steam generating means, and a safety device for preventing an abnormal temperature rise of the steam superheating means, By installing with a certain clearance from the steam superheating means, the safety device will not directly detect the temperature of the steam superheating means, but will detect the ambient temperature around the steam superheating means, such as normal use and continuous use Various usage conditions can not only reduce variations in the detected temperature of the safety device, but also eliminate contact variations between the steam heating means and the safety device.

2nd invention is the rice cooker main body with which the upper surface opened, the pan accommodated in the said rice cooker main body so that attachment or detachment is possible, the lid | cover which opens and closes the said rice cooker main body, and the heating means which heats the said pan, A steam generating means for generating steam, a steam superheating means for increasing the temperature of the steam generated from the steam generating means, a steam superheating means fixing base for fixing the steam superheating means, and an abnormal temperature rise of the steam superheating means A safety device for prevention, and the safety device is fixed on the steam superheating means between the steam superheating means and the safety device by providing a certain gap with the steam superheating means on the steam superheating means fixing base. A stand is present, and by stabilizing the temperature of the safety device in various usage states such as normal use and continuous use, it is possible to easily distinguish between normal use and abnormal normal state.

  In the third invention, in particular, by installing a plurality of safety devices of the first or second invention, even if one safety device breaks down, the other safety device is substituted, thereby ensuring more safety. be able to.

  According to the fourth aspect of the invention, in particular, by covering the steam superheating means and the safety device of any one of the first to third inventions with a heat insulating member, the ambient temperature of the steam superheating means is hardly affected by the outside air temperature. The detection temperature of the safety device can be stabilized without being affected by the temperature.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
The whole structure of the rice cooker concerning embodiment of this invention is demonstrated using FIG. 1 or FIG. FIG. 1 is a schematic cross-sectional view of a rice cooker according to an embodiment of the present invention. FIG. 2 is a top view schematically showing a state in which a part of the lid of the rice cooker of FIG. 1 is cut away.

  As shown in FIG. 1, the rice cooker concerning this embodiment is accommodated in the substantially bottomed cylindrical rice cooker main body 1 in which the pot accommodating part 1a was formed, and the pot accommodating part 1a, and rice and water are contained. It has a pan 2 that can be put in. A lid 3 having a hollow structure capable of opening and closing the upper opening of the rice cooker body 1 is attached to the top of the rice cooker body 1. A substantially disc-shaped inner lid (also referred to as a heating plate) 4 capable of sealing the upper opening of the pan 2 is detachably attached to the inside of the lid 3 (the side covering the opening of the pan 2).

  The pot storage part 1a of the rice cooker body 1 is composed of an upper frame 1b and a coil base 1c. The upper frame 1b has a cylindrical portion 1ba that is arranged so that a predetermined gap is provided with respect to the side wall of the stored pan 2, and an upper opening of the rice cooker body 1 that protrudes outward from the upper portion of the cylindrical portion 1ba. And a flange portion 1bb fitted to the inner peripheral portion. The flange portion 1bb is formed with a water tank storage portion 1bc for storing the water tank 5. The water tank 5 is a bottomed cylindrical container that holds water for generating steam. A water tank heating coil 6, which is an example of a water tank heating device for heating (induction heating) the water tank 5, is attached to the outer peripheral surface of the water tank housing 1 bc. Instead of the water tank heating coil 6, the water tank 5 may be heated by a heater. When the water tank heating coil 6 heats the water tank 5, the water in the water tank 5 boils and steam of about 100 ° C. is generated. In addition, an opening is provided in the side portion of the water tank storage portion 1bc. In the opening portion, a water tank temperature sensor 7 for measuring the temperature of the water tank 5 is disposed so as to be able to contact a side portion of the water tank 5 stored in the water tank storage portion 1bc.

  The coil base 1c is formed in a bottomed cylindrical shape corresponding to the shape of the lower portion of the pan 2, and the upper portion is attached to the lower end portion of the cylindrical portion 1ba of the upper frame 1b. A pan bottom heating unit 8 which is an example of a pan heating device for heating (induction heating) the pan 2 is attached to the outer peripheral surface of the coil base 1c. The pan bottom heating unit 8 includes an in-bottom heating coil 8a and an out-bottom heating coil 8b. The in-bottom heating coil 8a is disposed so as to face the periphery of the center of the bottom of the pan 2 via the coil base 1c. Outer bottom heating coil 8b is arranged so as to face the corner portion of the bottom of pan 2 via coil base 1c.

An opening is provided in the central portion of the bottom of the coil base 1c. In the opening portion, a pan temperature sensor 9 which is an example of a pan temperature detecting unit for measuring the temperature of the pan 2 is disposed so as to be able to contact the bottom of the pan 2 stored in the pan storage unit 1a. . Since the temperature of the pan 2 is substantially the same as the temperature of the cooked rice in the pan 2, the pan temperature sensor 9 can detect the temperature of the cooked rice in the pan 2 by detecting the temperature of the pan 2. .

  The lid 3 includes an upper outer member 3 a and a lower outer member 3 b that constitute the outer shell of the lid 3. The lid 3 includes a hinge shaft 3A. The hinge shaft 3A is an opening / closing shaft for the lid 3, and both ends of the hinge shaft 3A are rotatably fixed to the upper frame 1b of the rice cooker body 1. The lid 3 is provided with a through hole 3c so as to penetrate the vicinity of the center portion in the thickness direction of the lid 3, and the steam cylinder 10 is detachably attached to the through hole 3c. Steam escape holes 10 a and 10 b are provided on the upper and bottom walls of the steam cylinder 10 so that excess steam in the pot 2 can be discharged to the outside of the rice cooker body 1. An annular packing 11 is attached around the through hole 3 c on the inner lid 4 side of the lid 3. The packing 11 is provided so as to be in close contact with the periphery of the steam escape hole 4 a provided in the inner lid 4 when the inner lid 4 is attached to the lid 3.

  In addition, an inner lid temperature sensor 12, which is an example of an inner lid temperature detection unit that detects the temperature of the inner lid 4, is attached to the lid 3. An inner lid heating coil 13, which is an example of an inner lid heating device for inductively heating the inner lid 4, is attached to the inner surface (inner side of the lid) of the lower outer member 3 b serving as the bottom wall of the lid 3.

  The inner lid 4 is made of a magnetic metal such as stainless steel capable of induction heating. An annular packing 14 is attached to the surface of the outer peripheral portion of the inner lid 4 on the pan 2 side. The packing 14 is provided in close contact with the flange portion of the pan 2 when the lid 3 is in the closed state.

  Moreover, the superheated steam generator 15 which is a steam heating means for throwing in superheated steam exceeding 100 degreeC in the pot 2 is provided in the inside of the lid | cover 3. As shown in FIG. The mounting structure of the superheated steam generator 15 will be described in detail later. The superheated steam generator 15 is configured to be able to generate superheated steam by heating steam at about 100 ° C. generated in the water tank 5. A steam supply pipe 16 and a superheated steam input pipe 17 are connected to the superheated steam generator 15. In addition, the superheated steam generator 15 is in contact with a superheated steam temperature sensor 18 that is an example of a superheated steam temperature detection unit that detects the temperature of the superheated steam generated by the superheated steam generator 15.

  The steam supply pipe 16 communicates with the inside of the water tank 5 when the lid 3 is in a closed state, and is provided so as to guide the steam generated in the water tank 5 to the superheated steam generator 15. An annular packing 19 is attached to the end of the steam supply pipe 16 on the water tank 5 side. The packing 19 is provided in close contact with the flange portion of the water tank 5 when the lid 3 is in the closed state.

  The superheated steam input pipe 17 communicates with the inside of the pan 2 through the superheated steam input hole 4b provided in the inner lid 4 when the lid 3 is in the closed state, and the superheated steam generated by the superheated steam generator 15 is stored in the pan 2. It is provided to be put in. An annular packing 20 is attached to the end of the superheated steam input pipe 17 on the pan 2 side. The packing 20 is provided in close contact with the periphery of the superheated steam supply hole 4b of the inner lid 4 when the lid 3 is in the closed state.

  In addition, the lid 3 has a display unit 21 such as a liquid crystal display that displays various information such as a rice cooking course and rice cooking time, and a plurality of rice cooking courses such as a white rice course, a brown rice course, and a white rice (softer) course. The operation part 22 which is an example of the rice cooking course selection part which can select this rice cooking course is provided. The operation unit 22 includes a plurality of buttons such as a rice cooking start button so that instructions for starting, canceling, or making a reservation for cooking can be given in addition to selecting a rice cooking course. The user can select a specific rice cooking course with the operation unit 22 while referring to the display content of the display unit 21 and instruct the start of rice cooking.

A rice cooker control unit 23 is mounted inside the rice cooker body 1. The rice cooking control unit 23 includes a storage unit that stores a plurality of rice cooking sequences for cooking rice. Here, the “rice cooking sequence” is mainly composed of four steps of preheating, temperature rising, boiling maintenance, and steaming. In performing each step in turn, the energizing time, heating temperature, heating time, heating output, etc. This is a predetermined cooking procedure. Each rice cooking sequence corresponds to one of a plurality of rice cooking courses. The rice cooking control unit 23 controls the driving of each unit and each device based on the rice cooking course selected by the operation unit 22 and the detected temperatures of the temperature sensors 7, 9, and 12, and executes the rice cooking process. In addition, the rice cooking control unit 23 causes the superheated steam generator 15 to generate superheated steam based on the rice cooking course selected by the operation unit 22 and the detected temperature of the superheated steam temperature sensor 18.

  Next, the mounting structure and internal structure of the superheated steam generator 15 will be described in more detail with reference to FIGS. FIG. 3 is a perspective view showing a state where the steam supply pipe 16 and the superheated steam input pipe 17 are attached to the superheated steam generator 15, and FIG. 4 is a schematic cross-sectional view thereof. 5 and 6 are cross-sectional views showing a state where safety devices 45a and 45b are attached to the superheated steam generator 15. FIG.

  As shown in FIGS. 3 and 4, the superheated steam generator 15 is connected to the steam supply pipe 16 and the superheated steam input pipe 17 via heat insulating materials 31 and 32 having elasticity such as rubber. With this configuration, heat generated in the superheated steam generator 15 is not transmitted to the steam supply pipe 16 and the superheated steam input pipe 17.

  The superheated steam generator 15 includes a cylindrical case 41 and a rod-shaped heater 42. The heater 42 is disposed in the case 41 coaxially with the central axis A1 of the case 41. The superheated steam generator 15 heats the steam supplied into the case 41 with the heater 42 to generate superheated steam.

  The heater 42 passes through one side wall 41a of the case 41 so that the heat generation range 42BB of the heat generation unit 42B is disposed in the case 41, and the tip end portion 42A contacts (fits) the other side wall 41b of the case 41. It is provided as follows. The case 41 is provided with a steam intake port 41 c that takes in the steam supplied through the steam supply pipe 16 and a superheated steam discharge port 41 d that discharges the superheated steam to the superheated steam input pipe 17. The steam intake port 41 c and the superheated steam discharge port 41 d are disposed in the vicinity of the heat generating portion 42 </ b> B of the heater 42. More specifically, the steam intake port 41 c and the superheated steam discharge port 41 d are disposed so as to face the heat generating portion 42 </ b> B of the heater 42. Further, around the heat generating part 42B of the heater 42, fins 43 made of a metal plate or the like are spirally provided.

  As shown in FIGS. 3, 4, and 5, an engagement claw 44, which is an example of an engagement portion, is formed on the outer peripheral surface of the case 41. The engagement claw 44 is engaged with an engagement hole 33a which is an example of an engaged portion provided in the fixing member 33 which is a steam heating means fixing base. The fixing member 33 is a metal (preferably inorganic) plate-like member formed so as to cover substantially the entire case 41 in plan view. The fixing member 33 is fixed to a plurality of bosses 3d erected on the lower outer member 3b of the lid 3 by fastening members 34 such as screws. That is, the superheated steam generator 15 is attached to the lower outer member 3b of the lid 3 via the fixing member 33 so as not to directly contact the upper outer member 3a and the lower outer member 3b. Further, the superheated steam generator 15 is in contact with the fixing member 33 only by the engaging claw 44 and is suspended by the fixing member 33.

  The superheated steam generator 15 is provided with a safety device 45a for preventing an abnormal temperature rise. The safety device 45a detects the temperature of the case 41 and prevents an abnormal temperature rise. However, the safety device 45a is not in direct contact with the case 41, but is installed in a state where a certain gap is secured. For example, in this configuration, the safety device 45 a is provided so as to contact the fixing member 33 that covers the case 41, but the fixing member 33 in the installation portion of the safety device 45 a is installed with a gap L from the case 41.

  In addition, since the safety device 45a is an important part for ensuring safety in the event of a product abnormality, the second safety device 45b is also installed to ensure product safety in the event of a failure. . Similarly to the first safety device 45a, the second safety device 45b also secures a certain gap L between the fixing member 33 of the installation portion and the case 41.

  Further, in order to prevent the temperature detection of the safety devices 45a and 45b from being affected by the environmental temperature, both the superheated steam generator 15 and the safety devices 45a and 45b are in the form of a sheet (preferably inorganic properties) having a lower thermal conductivity than air. The heat insulating member 46, for example, a silica heat insulating member, is covered with the heat insulating material for the superheated steam generator.

  According to the present embodiment, the superheated steam generator 15 and the steam supply pipe 16 and the superheated steam generator 15 and the superheated steam input pipe 17 are connected via the heat insulating materials 31 and 32 having elasticity. It is possible to suppress the heat generated by the steam generator 15 from diffusing throughout the steam supply pipe 16 and the superheated steam input pipe 17. This is because the heat generated by the superheated steam generator 15 is reduced by the heat insulating materials 31 and 32 from being transferred to the steam supply pipe 16 and the superheated steam input pipe 17.

  Further, since the superheated steam generator 15 is attached to the lower outer member 3b via the fixing member 33 so as not to directly contact the upper outer member 3b and the lower outer member 3b, the heat generated in the superheated steam generator 15 Can be diffused by the fixing member 33 to reduce the amount of heat transferred to the lower outer member 3b. Accordingly, the deformation of the outer member of the lid 3 can be suppressed, and the temperature of the superheated steam can be further increased (for example, 200 ° C. or higher).

  Moreover, according to this embodiment, since the superheated steam generator 15 contacts with the fixing member 33 only by the engaging claw 44, the contact area between the fixing member 33 and the superheated steam generator 15 can be reduced. it can. Further, since the superheated steam generator 15 is suspended by the fixing member 33, heat can be diffused also from the outer peripheral surface of the case 41. Thereby, it is possible to suppress the temperature of the fixing member 33 from rising excessively, and to further suppress deformation of the outer member of the lid 3.

  Further, according to the present embodiment, since the fixing member 33 is formed so as to cover substantially the entire case 41 in plan view, the heat generated by the superheated steam generator 15 is transmitted to the upper outer member 3a. The fixing member 33 can function as a shielding plate that suppresses the above. Thereby, even if it is during rice cooking, it can suppress that the upper outer member 3a which a user can touch becomes high temperature. Therefore, the risk of burns can be further suppressed.

  In addition, according to the present embodiment, since the steam at 100 ° C. is generated by a device different from the superheated steam generator 15, the output of the heater 42 can be lowered, and the superheated steam generator 15 Downsizing can be realized. Moreover, since it is not necessary to supply water in the case 41 of the superheated steam generator 15, it is possible to suppress the adhesion of scale in the case 41 and the decrease in thermal efficiency.

  Further, according to the present embodiment, since the tip end portion 42A of the heater 42 is provided so as to contact the side wall 41b of the case 41, the heat of the heater 42 is directly transmitted to the case 41, and the steam in the case 41 is Heating can be efficiently performed from both the heater 42 and the inner surface of the case 41. Thereby, it is possible to further increase the temperature of the superheated steam and reduce the size of the apparatus. In addition, when the front-end | tip part 42A of the heater 42 and the side wall 41b of the case 41 are contacted, compared with the case where they are not contacted, the temperature of the case 41 can be raised about 70-80 degreeC, for example.

  Since the heater 42 and the case 41 have different shapes from each other, the connection portion between the heater 42 and the case 41 may be broken due to expansion or contraction due to thermal stress when the heat is cooled. For this reason, it is preferable that the front end portion 42 </ b> A of the heater 42 is fitted or brought into contact with the side wall 41 b of the case 41 instead of being integrally fixed. Thereby, it can suppress that the connection part of the heater 42 and the case 41 breaks.

  Further, according to the present embodiment, since the steam intake port 41c is arranged in the vicinity of the heat generating part 42B of the heater 42, the temperature difference between the steam taken in from the steam intake port 41c and the heat generating part 42B is large. Thus, heat exchange is efficiently performed. Thereby, the temperature of steam can be raised rapidly and the heating efficiency of steam can be improved. In addition, the heater 42 can be downsized.

  Further, according to the present embodiment, since the fins 43 are spirally provided around the heater 42, the steam can be spirally moved along the fins 43, and the steam movement path can be lengthened. it can. Further, since the steam is also heated from the fins 43 to which the heat of the heater 42 is transmitted, the contact area between the steam and the heat source (the heaters 42 and the fins 43) increases. Therefore, the heat of the heater 42 can be efficiently applied to the steam, and the steam heating efficiency can be further improved. In addition, the heater 42 can be downsized.

  When the case 41 and the fins 43 are configured to come into contact with each other, dimensional variation is likely to occur particularly in the contact portion between the case 41 and the fins 43 during mass production. In this case, the temperature of the superheated steam discharged from the superheated steam discharge port 41d varies. For this reason, it is preferable that the case 41 and the fin 43 are non-contact. However, if the gap between the case 41 and the fins 43 is increased, the amount of steam that flows through the gaps without flowing along the fins 43 increases, and the steam heating efficiency decreases. For this reason, it is preferable to make the gap between the case 41 and the fin 43 as small as possible (for example, 1.5 mm or less).

  In addition, when the vapor contains components such as calcium chloride and magnesium chloride, if those components adhere to and accumulate on the case 41 and the fins 43, the vapor hardly flows (or does not flow). For this reason, as materials for the fins 43 and the case 41 that are in contact with the steam, it is preferable to select an all-stenitic high corrosion-resistant material so that oxidation, corrosion, stress corrosion cracking, and the like due to steam do not occur.

  Further, when superheated steam is generated in the case 41, the inside of the case 41 becomes a high pressure (about 1.02 atm). For this reason, it is preferable that the member for sealing each connection portion such as the connection portion between the case 41 and the heater 42 is brazed using nickel wax or the like instead of a commonly used rubber member such as silicon or fluorine.

  In addition, it is necessary to set the operating temperature to a temperature at which the safety device does not operate in normal use and operates only in abnormal use. For this reason, in normal use, it is necessary to ensure a certain degree of temperature margin and to operate reliably in order to ensure safety during abnormal use. Therefore, the maximum of safety devices 45a and 45b during normal use, including continuous cooking It is necessary to set the operating temperature with a temperature margin from the temperature. For this reason, when the temperature variation of the safety devices 45a and 45b increases during normal use, the operating temperature is set in a state in which a margin value from the maximum temperature is secured, and thus detection may be delayed during abnormal use.

  From the above, the temperature of the safety devices 45a and 45b can be set lower as the variation in the detected temperature is smaller during normal use, and the safety of the product can be further enhanced.

  In this configuration, the safety devices 45a and 45b are installed with a certain clearance L from the case 41. However, when the safety devices 45a and 45b are installed in contact with the case 41 directly, the temperature of the case 41 is directly detected. When the temperature gradient of the case 41 is large, the difference between the detected temperatures of the safety devices 45a and 45b tends to increase, and when the temperature gradient is small, the detected temperature decreases. As a result, the detected temperature of the safety devices 45a and 45b changes due to the temperature gradient of the case 41 due to the temperature gradient of the case 41, and the detected temperature varies. In order to absorb the difference in temperature gradient, a certain gap L is provided and the safety devices 45a and 45b are installed through the air layer to absorb the difference in temperature gradient.

  In addition, the rice cooker may be used continuously, and a difference between the first case 41 temperature and the second and subsequent case temperatures may occur. Therefore, if the temperature of the case 41 is detected directly, the safety devices 45a and 45b. Both the detected temperature and the difference in the temperature increase greatly depending on the number of rice cooking. In order to absorb this variation, the safety devices 45 a and 45 b ensure a gap L with the case 41.

  However, providing a gap L between the case 41 and the safety devices 45a and 45b and having an air layer causes the influence of the environmental temperature to be used, but in order to reduce the influence of the environmental temperature. In this configuration, the superheated steam generator 15 and the safety devices 45a and 45b are entirely covered with the heat insulating member 46.

  By covering all of the superheated steam generator 15 and safety devices 45a and 45b with the heat insulating member 46, the influence of the operating environment temperature can be reduced, and the variation in the temperature of the case 41 can also be suppressed, enabling more stable temperature detection. It becomes.

  The heat insulating member 46 also serves to protect the upper outer member 3a and the lower outer member 3b from the high temperature of the superheated steam generator.

  Moreover, since the superheated steam generator 15 is suspended by the fixing member 33, the heat insulation member 46 does not apply the own weight of the superheated steam generator 15. Therefore, the heat insulation member 46 is not compressed by the dead weight of the superheated steam generator 15 and the heat insulation performance does not deteriorate.

  The condition for determining the operating temperature of the safety devices 45a and 45b is to ensure a certain margin from the temperature of the safety devices 45a and 45b for normal rice so that they do not operate during normal use. It is necessary to set the operating temperature so that the rice cooker operates in a state where safety can be ensured.

  First, in FIG. 7, when the temperature of the superheated steam generator 15 during normal rice cooking is viewed, the temperature of the superheated steam generator 15 varies depending on each rice cooking course, and among them, the superheated steam generator 15 reaches the highest temperature. It is necessary to ensure a certain margin from the temperature of the safety devices 45a and 45b. At this time, if the safety devices 45a and 45b are installed in contact with the superheated steam generator 15, the temperature of the safety devices 45a and 45b is A2, and the operating temperature of the safety devices 45a and 45b is B2. When the safety devices 45a and 45b are installed in the superheated steam generator 15 with a gap, the detected temperature of the safety devices 45a and 45b is A1, and the operating temperature can be B1. From the above, when the safety devices 45a and 45b are installed with a clearance from the superheated steam generator 15, the set temperature can be set lower by B2-B1.

  Furthermore, when taking into account the case of continuous rice cooking, if the safety devices 45a and 45b are installed directly on the superheated steam generator 15, the detected temperature is A4 and the operating temperature needs to be B4. Then, the detected temperature can be A3 and the operating temperature can be B3.

  From the above, considering various usages of the rice cooker, the set temperature of the safety devices 45a and 45b needs to be set to B4 or B3.

  Next, looking at the temperature of the safety devices 45a and 45b when the rice cooker operates abnormally, when the operating temperature is set to B4, the operating temperature of the safety device is T2, and when the operating temperature is B3, the operating time is At T1, the safety devices 45a and 45b can operate faster by T2-T1 minutes. When the abnormal operation is performed, the safety devices 45a and 45b are operated as quickly as possible, so that the rice cooker is less damaged and the safety is improved.

  As described above, the safety devices 45a and 45b are improved in safety by setting a clearance with the superheated steam generator 15.

  In addition, this invention is not limited to the said embodiment, It can implement in another various aspect. For example, in the above description, the steam supplied to the superheated steam generator 15 is generated by heating the water in the water tank 5, but the present invention is not limited to this. For example, steam generated in the pan 2 during rice cooking may be supplied to the superheated steam generator 15.

  In the above description, the air layer is formed between the case 41 and the lower outer member 3b, but the present invention is not limited to this. For example, a sheet-like (preferably inorganic physical) heat insulating member having a lower thermal conductivity than air, such as a silica heat insulating member, may be provided between the case 41 and the lower outer member 3b.

  Since the rice cooker concerning this invention can suppress the deformation | transformation of the outer member of a lid | cover, etc., and can make the temperature of superheated steam still higher, it is useful as a household rice cooker for business use, etc.

1 Rice cooker body 2 Pot 3 Lid 6 Water tank heating coil (steam generator)
8 Pan bottom heating unit (heating means)
15 Superheated steam generator (steam superheating means)
33 Fixing member (steam heating means fixing base)
46 Thermal insulation material

Claims (4)

A rice cooker body with an open top;
A pan that is detachably stored in the rice cooker body;
A lid for freely opening and closing the rice cooker body;
Heating means for heating the pan;
Steam generating means for generating steam;
Steam superheating means for raising the temperature of the steam generated from the steam generating means;
Having a safety device for preventing an abnormal temperature rise of the steam overheating means,
The safety device is a rice cooker installed with a certain gap from the steam superheating means. A rice cooker body with an open top;
A pan that is detachably stored in the rice cooker body;
A lid for freely opening and closing the rice cooker body;
Heating means for heating the pan;
Steam generating means for generating steam;
Steam superheating means for raising the temperature of the steam generated from the steam generating means;
A steam superheating means fixing base for fixing the steam superheating means;
Having a safety device for preventing an abnormal temperature rise of the steam overheating means,
The safety device is a rice cooker provided on the steam superheating means fixing base with a certain clearance from the steam superheating means. The rice cooker according to claim 1 or 2, wherein a plurality of safety devices are installed. The rice cooker according to any one of claims 1 to 3, wherein the steam superheating means and the safety device are covered with a heat insulating member.

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