JP2005118318A - Rice cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small, lightweight and inexpensive rice cooker that can perform an appropriate heating power control in accordance with the weight of an object of cooking, exhibits a good rice cooking performance, and uses electromagnetic induction heating. <P>SOLUTION: The rice cooker has a body, the top of which is opened, a pot removably stored in the storage section of the body, a lid openably covering the storage section, an induction heating means for induction heating the pot, a weight sensing element directly or indirectly mounted to the storage portion and a sensor directly or indirectly mounted to the weight sensing element and abutting against the near center of the outside bottom of the pot. The rice cooker also has a weight sensing means for sensing the total weight of the pan and the object of cooking put in the pot by the weight sensing element through the sensor and a control section computing the weight of the object of cooking on the basis of an output signal of the weight sensing means and controlling the percentage of current carried and/or the amount of current carried by the induction heating means in accordance with the weight of the object of cooking. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a rice cooker.

  In recent years, rice cookers using electromagnetic induction heating have become widespread in the market. Conventional rice cookers that use electromagnetic induction heating (induction heating rice cookers) have an induction heating coil on the outside of the pan bottom, and use the magnetic force generated from the induction heating coil to heat the pan itself. You can cook plump and delicious rice compared to the example rice cooker.

On the other hand, in order to improve the taste of rice, rice cookers that determine the amount of rice and water in the pan (the amount of cooked rice) and control the amount of heating according to the amount of cooked rice have become widespread. Conventionally, a method is known in which the amount of cooked rice is determined from the rate of temperature rise of a pan during heating (for example, when boiling after rice is absorbed at a predetermined temperature). However, in this case, the thermal power control is impossible until the temperature reaches a predetermined value and the amount of cooked rice is determined. Therefore, when the amount of cooked rice is small, the water boils before water absorption is sufficiently performed, and the core remains in the rice, and the rice may become hard.
Japanese Patent Publication No. 1-272724 discloses a conventional rice cooker. The rice cooker of the conventional example detects the weight of the inner pot (total weight of the inner pot, water and rice) by the weight detection means at the same time as the start of rice cooking, determines the amount of rice cooking, and the electric energy of the heater during cooking (thermal power) To control. Therefore, the thermal power control commensurate with the amount of cooked rice becomes possible at the start of cooking, and delicious rice can be cooked.
Japanese Examined Patent Publication No. 1-2724

A conventional rice cooker disclosed in Japanese Patent Publication No. 1-272724 has a main body, a bottom frame, and a bottom lid that is inserted inside the bottom frame. When the pan is stored in the main body, the distance between the electrodes attached to the bottom frame and the bottom lid changes in proportion to the total weight of the pan and the main body. A change in capacitance between electrodes is detected as a change in oscillation state, and the amount of rice cooked is detected. However, the conventional rice cooker has a problem that the overall size of the rice cooker relative to the pan is large, and the carrying and installation properties are poor. Furthermore, there is a problem that the number of parts is large and the assemblability is poor.
When attaching the same weight detection means as the conventional rice cooker to the induction heating rice cooker, the following problems occurred. In an induction heating rice cooker, when cooking rice, the pan itself is heated to a high temperature to cause convection of water in the pan, and the rice is heated by heat conduction by the convection. Therefore, in order to uniformly heat the rice and water in the pan and not cause uneven cooking, the positional relationship between the pan and the induction heating coil is fixed to an optimal state, and a predetermined state is determined according to the amount of rice cooked. It is necessary to cause convection of strength in the pan. For this reason, the induction heating coil often has a three-dimensional complicated shape. On the other hand, a storage unit (comprising an upper frame and an upper coil base) in which an induction heating coil is built is usually produced from a resin in view of moldability and mass productivity. Since the pot becomes hot and the heat resistance of the resin is not so high, in general, the induction heating rice cooker has a pan that is horizontally suspended at the upper end of the storage part by its flange, etc., and there is a gap between the pot and the storage part . Therefore, the same weight detection means as the conventional rice cooker could not be attached to the induction heating rice cooker.

The present invention solves the above-described conventional problems, and is a small, lightweight, inexpensive, rice cooker that exhibits excellent rice cooking performance using electromagnetic induction heating, capable of appropriate thermal power control according to the weight of the food. The purpose is to provide.
In a rice cooker using electromagnetic induction heating, the distance between the induction heating coil and the pan needs to be kept constant. The present invention provides a rice cooker using electromagnetic induction heating that accurately measures the weight of the cooked food while keeping the distance between the induction heating coil and the pan constant and appropriately controls the thermal power according to the measured value. The purpose is to do.

  In order to solve the above problems, the present invention has the following configuration. The invention according to claim 1 is a main body having an open upper surface, a pan that is detachably stored in a storage portion of the main body, a lid that covers the storage portion so as to be openable and closable, and induction heating that induction-heats the pan. Means, a weight detection element that is directly or indirectly attached to the storage section, and a detection body that is directly or indirectly attached to the weight detection element and abuts on a substantially central portion of the outer bottom portion of the pan. The weight detection means for detecting the total weight of the pan and the food put in the pan by the weight detection element via the detection body, and the weight of the food based on the output signal of the weight detection means A rice cooker comprising: a controller that calculates and controls an energization rate and / or energization amount to the induction heating means according to the weight of the cooked food.

The rice cooker of the present invention calculates the weight of the cooked food before the start of cooking, and performs thermal power control (control of energization rate and / or energization amount to the induction heating means) according to the weight. Regardless, you can cook delicious rice.
According to the present invention, since the weight detection means is configured with a small number of parts, a small, lightweight and inexpensive rice cooker can be realized. Since the weight is detected at the substantially central portion of the outer bottom portion of the pan, even if the position of the pan stored in the storage portion is shifted, the error in the weight measurement value is small.
The induction heating means for induction heating the pan is typically an induction heating coil attached to the bottom of the storage unit (the portion facing the outer bottom of the pan). The induction heating coil is a winding having a center substantially directly below the center of the bottom of the pan. In the present invention, the weight detection means supports and measures the weight of the pan at the substantially central portion of the outer bottom thereof. Therefore, the weight detection means can be attached without interfering with the induction heating coil. Since the pan supported at the center of the bottom is stably placed in the storage portion, the induction heating coil can heat the pan appropriately and stably.
Since the rice cooker of this invention supports the approximate center part of a pan with a detection body, a pan does not tilt. Therefore, the distance between the pan and the induction heating coil is kept constant, and excellent rice cooking performance can be exhibited.
“The total weight of the pot and the food in the pot” means the total weight of the object including at least the pot and the food in the pot.

The invention according to claim 2 is characterized in that an insulating member connected to the weight detection element and the detection body is provided between the weight detection element and the detection body. It is a rice cooker.
According to the present invention, since the insulating member can prevent static electricity from entering the weak electric circuit, a safe rice cooker can be provided with a simple configuration. The insulating member is not likely to be heated by the leakage magnetic flux of the induction heating coil.

Invention of Claim 3 is further equipped with the pan detection means which detects whether the said pan is accommodated in the said accommodating part in the approximate center part of the outer bottom part of the said pan. It is a rice cooker as described in.
According to the present invention, in a small, light and inexpensive configuration, the measurement of the total weight of the pot and the food put in the pot, and the detection of the presence or absence of the pot, both of the approximate center of the outer bottom of the pot Can be done.

The invention according to claim 4 is characterized in that the detection body has a cylindrical shape, and is provided with temperature detection means for detecting the temperature of the pan inside thereof. It is a rice cooker as described in the claim.
According to the present invention, in a small, lightweight and inexpensive configuration, detection of the temperature of the pan and measurement of the total weight of the pan and the food put in the pan (or further detection of the presence or absence of the pan), Both can be done at the approximate center of the outer bottom of the pan. Even if the position of the pan stored in the storage section is shifted, errors in the detected temperature and the weight measurement value are small. Or there is no risk of false detection of the presence or absence of a pan.

The invention according to claim 5 is characterized in that the temperature detecting means is urged upward by an elastic body so that the upper surface of the temperature detecting means protrudes above the upper surface of the detecting body. It is a described rice cooker.
According to the present invention, the temperature detecting means is not excessively stressed by the elastic body (for example, a spring) and the detecting body. Due to the elastic body, the temperature detecting means reliably contacts the bottom surface of the pan and accurately detects the temperature. The weight detection means accurately detects the total weight of the pot and the food put in the pot via the detection body.

  The invention according to claim 6 is the rice cooker according to any one of claims 1 to 5, wherein the weight detection element is a load cell or a piezoelectric element. Since the distance between the pan and the induction heating coil does not change depending on the weight of the object to be heated, the induction heating coil can stably heat the pan without being affected by the weight of the non-heated object. These elements are highly reliable and can accurately measure the weight because there is no risk of eddy currents flowing due to leakage magnetic flux of the induction heating coil to increase the temperature.

According to a seventh aspect of the present invention, a guide roller mounting portion that holds a guide roller that contacts the side surface of the pan and a bearing portion that rotatably supports the guide roller in a vertical direction is provided at an upper portion of the storage portion. The rice cooker according to any one of claims 1 to 6, comprising at least three.
Since the guide roller in contact with the pan rotates only in the vertical direction, the pan is stored smoothly. Furthermore, since the pan is supported by the guide roller not only from the detection body but also from the side surface, the posture of the pan is further stabilized and the weight detection accuracy is improved. Furthermore, since the distance between the induction heating means and the pan is kept constant, the induction heating means can appropriately and stably heat the pan. The rice cooker of this invention can exhibit the outstanding rice cooking performance.
Since the pan does not move in the circumferential direction, the pan does not rotate when the user tries to remove the rice from the pan.

The invention according to claim 8 includes a guide roller that contacts the side surface of the pan, and a bearing that pivotally supports the guide roller so as to be rotatable in the vertical direction and can be displaced in a direction orthogonal to the side surface of the pan. 7. The apparatus according to claim 1, further comprising: a spring member; and at least three guide roller mounting portions that are provided on an upper portion of the storage portion and hold the spring member so as to be displaceable. 8. It is a rice cooker as described in the claim.
Since the guide roller in contact with the pan rotates only in the vertical direction and is displaced in a direction perpendicular to the side surface of the pan, the pan is smoothly stored even if the pan size varies. Furthermore, since the pan is supported by the guide roller not only from the detection body but also from the side surface, the posture of the pan is further stabilized and the weight detection accuracy is improved. Furthermore, since the distance between the induction heating means and the pan is kept constant, the induction heating means can appropriately and stably heat the pan. The rice cooker of this invention can exhibit the outstanding rice cooking performance.

The invention according to claim 9 is characterized in that the guide roller has, on the outer periphery thereof, a rubber pan detent having a groove portion that is parallel to the rotation direction of the guide roller and has a V-shaped cross section. It is the rice cooker of Claim 7 or Claim 8 to do.
The pan stopper comes into contact with the pan while opening when the pan is stored. Therefore, the pan does not rotate when the user tries to cook rice from the pan.

INDUSTRIAL APPLICABILITY The present invention has an advantageous effect that it is possible to realize a rice cooker that can perform appropriate thermal power control according to the weight of the cooked food and that is small, lightweight, inexpensive, and that exhibits excellent rice cooking performance using electromagnetic induction heating. .
The present invention realizes a rice cooker using electromagnetic induction heating that accurately measures the weight of the cooked food while keeping the distance between the induction heating coil and the pan constant and appropriately controls the heating power according to the measured value. There is an advantageous effect of being able to.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments that specifically show the best mode for carrying out the present invention will be described below with reference to the drawings.

Embodiment 1
The rice cooker of Embodiment 1 of this invention is demonstrated using FIG.1, FIG.2 and FIG.3.
FIG. 1 is a partially cutaway side view of a rice cooker according to an embodiment of the present invention. A sectional view is shown in the broken part. In order to simplify the drawing, lead wires and the like for electrical connection are omitted. In FIG. 1, 10 is a body (main body) of a rice cooker. The body 10 is provided with a lid 20 that covers the upper surface thereof so as to be freely opened and closed. The housing portion 30 of the body 10 includes an upper frame 32 and a lower coil base 31. Reference numeral 12 denotes a pan formed of a magnetic material such as stainless steel or iron. The pan 12 has a flange 121 protruding outward from the upper end opening, and is detachably stored in the storage unit 30 by placing the flange 121 in a state of being lifted from the upper end of the upper frame 32. The pan 12 has a gap with the storage portion 30 during storage. An induction heating coil 13 that induction-heats the pan 12 is disposed at a portion of the coil base 31 that faces the bottom of the pan 12. The induction heating coil 13 includes an outer coil disposed outside the bottom surface of the coil base 31 and an inner coil disposed inside the bottom surface. Each induction heating coil is a winding having a center substantially directly below the center of the bottom of the pan 12. Reference numeral 14 denotes a circuit board. A microcomputer (not shown) is mounted on the circuit board 14. The microcomputer controls the current for generating an alternating magnetic field in the induction heating coil 13 by software. The rice cooker of Embodiment 1 induction-heats the pan 12 and heats the food 19 in the pan 12. The cooked food 19 is rice before cooking rice, water, cooked rice, or the like.

Reference numeral 21 denotes a base fixed with a gap at the bottom of the coil base 31. The base 21 is provided with weight detecting means 40 for detecting the weight of the pan 12, pot detecting means 16 for detecting the presence or absence of the pot 12, and temperature detecting means 52 for detecting the temperature of the pot 12. The configuration of each detection means will be described with reference to FIGS. FIG. 2 is an exploded perspective view of main parts of the rice cooker according to the first embodiment.
The weight detection means 40 includes a load cell 41, a sensor base (insulating member) 42, and a contact tube (detecting body) 43. The load cell 41 is a robust type load transducer (weight detection element). The load cell 41 has a screw hole 411 at one end and a screw hole 412 at the other end. A thin plate 211 having a screw hole 212 is attached to the base 21. One end of the load cell 41 is screwed to the base 21 via a screw hole 212 and a screw hole 411. The other end of the load cell 41 has a gap with respect to the base 21. A resistance wire strain gauge 413 is attached to the load cell 18. A change in resistance of the strain gauge 413 when the load cell 18 is bent by a load is taken out as an electrical signal by the bridge circuit.

Reference numeral 42 denotes a resin sensor base. The load cell 41 is fitted into the recess 421 of the sensor base 42. The sensor base 42 is screwed to one end of the load cell 41 through a screw hole 422 and a screw hole 412.
Reference numeral 43 denotes a contact tube (detecting body) formed of aluminum having a thickness of 2 mm. The contact tube 43 has two claw portions 431 facing the lower side. The stopper cylinder 43 is fixed to the sensor base 42 by passing the claw portion 431 through the stopper cylinder fixing hole 423 of the sensor base 42 and bending it. The contact tube 43 has a flange 432 protruding inward at the upper end. An induction heating coil 13 is disposed outside the bottom surface of the coil base 31. The contact cylinder 43 is passed through one through hole provided in the central portion of the bottom of the coil base 31 (the central portion of the induction heating coil 13 where the induction heating coil 13 is not disposed). The The upper end of the contact tube 43 is higher than the inner bottom portion of the coil base 31 (FIG. 1). The weight detecting means 40 measures and supports the weight of the pan 12 only at the substantially central portion of the outer bottom thereof. Therefore, the weight detection means 40 can be attached without interfering with the induction heating coil 13. Since the pan 12 supported by the center of the bottom is stably disposed in the storage unit 30, the induction heating coil 13 can heat the pan 12 appropriately and stably.

  The temperature detection means 52 has two collars 521 facing the upper part, and is inserted into the contact tube 43 from the lower side. The outer diameter of the collar 521 is substantially the same as the inner diameter of the contact cylinder 43, and the temperature detection means 52 does not come out from the contact cylinder 43. Further, a spring 51 is inserted between the contact tube 43 and the temperature detection means 52. The spring 51 abuts on the lower surface of the collar 521 and the sensor base 42 and urges the temperature detection means 52 so that the temperature detection means 52 is in close contact with the pan 12. An electrical signal corresponding to the temperature of the pan 12 detected by the temperature detection means 52 is input to the circuit board 14 via the lead wire 53 and the connector 54. The lead wire 53 is pulled out from the groove 424 of the sensor base 42.

When there is no pan 12 in the storage unit 30, the upper surface of the collar 521 of the temperature detecting means 52 is in contact with the lower surface of the flange 432 of the abutting cylinder 43. The upper surface of the temperature detecting means 52 is located higher than the upper surface of the flange 432.
When the pot 12 is stored in the storage section 30, the bottom of the pot 12 first comes into contact with the temperature detection means 52, and finally comes into contact with the temperature detection means 52 and the contact cylinder 43 (FIG. 1). Therefore, since the batting cylinder 43 supports the pan 12 at the center, the pan 12 does not tilt. The load cell 41 detects and outputs the total weight of the pan 12, the food 19, the sensor base 42, the spring 51, the temperature detection means 52, and the contact cylinder 43. The temperature detecting means 52 sinks into the contact tube 43 by the spring 51, and the upper surface thereof is in contact with the bottom of the pan 12 at the same height as the upper surface of the flange 432. The temperature detection means 52 contacts the bottom of the pan 12 with an appropriate pressure defined by the spring 51 without applying an excessive force.

The pan detection means 16 is composed of a micro switch fixed to the base 21 (FIG. 1). When the pan 12 is stored in the storage unit 30, the bottom of the sensor base 42 comes into contact with the microswitch, and the pan detecting means 16 outputs an ON signal. The operation stroke of the microswitch is larger than the displacement amount of the sensor base 42 on which the pan 12 is placed. Thereby, even when the pan 12 is placed on the sensor base 42 and the micro switch is operated, the weight of the pan 12 supported by the micro switch is very small and does not affect the measurement value of the weight detection means 40. You may comprise so that the microswitch may not support the weight of the pan 12 more than fixed by driving a microswitch via an actuator (for example, the phosphor bronze board which has spring property).
Electric signals from the temperature detection means 52, the pan detection means 16 and the weight detection means 40 (load cell 41) are input to the circuit board 14, respectively.

The microcomputer mounted on the circuit board 14 stores in advance a predetermined state (when the pan 12 is not present, when the empty pan 12 is stored, the maximum amount of rice and the pan 12 filled with water are stored. Output signal data (S1, S2, S3) of the load cell 41 at the time of When the magnitude of the output signal of the load cell 41 is S, the weight W of the food 19 in the pan 12 is
W = Wmax × (S−S2) / (S3−S2)
It becomes. However, Wmax is the maximum weight of the food 19 and is a known amount (a pot 12 containing the maximum amount of rice and water (the food 19), the sensor base 42, the spring 51, the temperature detection means 52, and the pad). This is the total weight of the cylinder 43 and a value corresponding to the output signal data S3 of the load cell 41). From this equation, the microcomputer calculates the weight of the food 19 and estimates the amount of cooked rice.

Operation | movement in the rice cooking process of the rice cooker of Embodiment 1 of this invention is demonstrated paying attention to the difference with the operation | movement of the conventional rice cooker which determines the amount of rice cooking by the temperature rise gradient of the temperature detection means 52 during rice cooking.
The cooking process is predominately chronologically pre-cooked, cooked, boiled, cooked, and steamed. In the pre-cooking process, the rice and water in the pan are heated so that the temperature of the pan 12 becomes a temperature suitable for water absorption of rice (50 ° C.). Next, in the cooking step, the pan 12 is heated with a predetermined amount of heat until the temperature of the pan 12 reaches a predetermined value (100 ° C.). In a conventional rice cooker, the amount of cooked rice is determined based on the temperature rise rate at this time. In the boiling maintenance step, the rice and water are heated until the water in the pan 12 is exhausted and the temperature of the pan 12 reaches a predetermined value exceeding 100 ° C. Finally, in the steaming process, heating (cooking) according to the amount of cooked rice and stopping of heating are repeated a plurality of times during a fixed time.

  The pre-cooking process will be described. 3 (a) and 3 (b) show the bottom of the pan (solid line) and the center of the cooked food (broken line) when cooking 1 go rice and 5 go rice using the rice cooker of the embodiment of the present invention. ) Temperature. FIG.3 (c) and (d) are the rice cookers of the prior art example which determines the amount of rice cooking in a cooking process, The pot bottom (solid line) in the pre-cooking process at the time of 1-cooking and 5-cooking rice The temperature at the center of the cooked product (broken line) is shown. The temperature of the pan bottom is detected by the temperature detecting means 52.

  The conventional rice cooker that determines the amount of cooked rice in the cooking step performs heating until the temperature detected by the temperature detecting means 52 becomes a temperature suitable for water absorption (50 ° C.) regardless of the amount of the cooked food 19. Thereafter, the temperature of the pan 12 is kept at 50 ° C. for a predetermined time (Ta), and the rice is absorbed. However, when the amount of cooked rice is large (FIG. 3 (d)), it takes time for the temperature of the whole cooked item 19 to reach 50 ° C., so the water absorption time at an appropriate temperature is insufficient. Therefore, the core remains in the rice.

  The rice cooker according to the embodiment of the present invention changes the temperature at the time of water absorption (the temperature detected by the temperature detecting means 52) according to the amount of the cooked item 19. For example, when the amount of cooked rice is 1 go, heating is performed until the temperature detected by the temperature detecting means 52 reaches 50 ° C. And the temperature of the pan 12 is kept at 50 degreeC for predetermined time (Ta), and rice is made to absorb water (FIG. 3 (a)). For example, when the amount of cooked rice is 5 go, heating is performed until the temperature detected by the temperature detecting means 52 reaches 60 ° C. And the temperature of the pan 12 is kept at 60 degreeC for predetermined time (Ta), and water is absorbed. Since the temperature of the central part of the cooked food 19 rises later than the outside temperature and reaches about 50 ° C., the rice can absorb water sufficiently.

  The cooking process will be described. In the conventional rice cooker that determines the amount of rice cooked in the cooking process, the pot 12 is kept at a predetermined temperature (100) with a predetermined heating power (the current conduction rate and / or the current conduction amount of the induction heating coil 13) regardless of the amount of the cooked food 19. C.). Therefore, when the amount of cooked rice is small, the rice is boiled too quickly and only the surface of the rice is gelatinized, leaving the core remaining. The rice cooker according to the embodiment of the present invention changes the heating power (the energization rate and / or the energization amount of the induction heating coil 13) in the cooking process according to the amount of rice cooking. That is, control is performed to weaken the thermal power as the amount of cooked rice is small so that the time required for the cooking process is constant regardless of the amount of cooked rice.

The rice cooker of Embodiment 1 of this invention calculates the amount of rice cooking correctly before a heating start, and performs the thermal power control according to the amount of rice cooking. Therefore, delicious rice can always be cooked regardless of the amount of cooked rice.
In addition, it is good also as a control method which changes the time of pre-cooking instead of the temperature at the time of pre-cooking according to the amount of rice cooking.

Since the rice cooker according to the first embodiment has a structure in which a resin sensor base 42 is provided between the batting cylinder 43 and the load cell 41, static electricity generated by friction between the pan 12, the batting cylinder 43, and the temperature detection means 52 is provided. Does not enter the weak electrical circuit. In the first embodiment, the sensor base 42 is made of resin, but it may be made of an insulating material.
According to the present invention, it is possible to realize a rice cooker that is small, light, and inexpensive with a small number of parts of the weight detection means 40.
In addition, the strength with respect to the impact of the body 10 can be increased by providing the contact 55 between the base 21 and the body 10.
The shape of the contact tube 43 is not limited to that shown in FIG. 2, and any shape that abuts against the bottom of the pan 12 when the pan 12 is stored in the storage unit 30 may be used. It is good also as a structure which provides the temperature detection means 52 in the outer side (for example, peripheral part of the bottom of the pan 12) of the contact cylinder 43. FIG.
As the weight detection element 41, only a piezoelectric element, a capacitance detection element, or a spring may be used. Preferably, the amount of displacement due to the weight of the pan 12 is very small (preferably the distance between the pan 12 and the induction heating coil 13 does not change due to the weight of the object to be heated), and the eddy is caused by the leakage magnetic flux of the induction heating coil 13. A sensing element (for example, a load cell or a piezoelectric element made of aluminum or an aluminum alloy) that does not cause a temperature rise due to current flow is used. The weight detected by the weight detection element 41 when the pan 12 is stored in the storage unit 30 includes at least the weight of the pan 12 (if the cook 19 is present, the pan 12 and the cook 19). good.
Since the pan 12 has a gap between the pan 12 and the storage portion 30 during storage, heat is not easily transmitted from the pan 12 to the storage portion 30. Therefore, the storage unit 30 (the coil base 31 and the upper frame 32) can be manufactured at low cost by resin molding.

  Preferably, the temperature detection means 52, the actuator of the weight detection element 41, and the pan detection means 16 (or the actuator) are arranged in this order from the top in the vicinity of the center of the rice cooker. The temperature detecting means 52 directly contacts the center of the bottom of the pan 12 and detects the temperature with high accuracy. The weight detection element 41 (or the sensor base 42 which is an actuator thereof) includes the pan 12, the temperature detection means 52, and the holding structure of the temperature detection means 52 (the spring 51 and the detection body 43 in the first embodiment). A structure that receives the weight it contains. The weight detection element 41 detects the weight of the pan 12 and the food 19 with high accuracy. The pan detection means 16 can detect the presence or absence of a pan based on the displacement of the sensor base 42.

As shown in FIG. 1, the position of the weight detecting element (load cell) 41 having a rectangular parallelepiped shape is slightly shifted from the center of the bottom of the pan by using the sensor base 42 (acting as an actuator of the weight detecting element 41). By arranging the pan detection means (microswitch) 16 under the sensor base 42, the weight detection element (load cell) 41 and the pan detection means (microswitch) 16 can be juxtaposed on the base 21. Thereby, the attachment structure of the weight detection element (load cell) 41 and the pan detection means (microswitch) 16 can be simplified, and the height of the whole rice cooker can be suppressed.
According to the rice cooker of the first embodiment, the measurement of the total weight of the pan 12 and the food 19 placed in the pan 12 and the detection of the presence or absence of the pan 12 are performed in a small, light and inexpensive configuration. Can also be performed at the approximate center of the outer bottom of the pan 12.

<< Embodiment 2 >>
The rice cooker of Embodiment 2 of this invention is demonstrated using FIG.4, FIG.5 and FIG.6. In the rice cooker according to the second embodiment, the upper frame 32 of the rice cooker according to the first embodiment is replaced with the upper frame 61, and a guide roller 70 is added to the upper end opening of the upper frame 61. Since it is the same as the rice cooker (FIGS. 1-3) of Embodiment 1 except the structure of the upper end opening part of the upper frame 61, the same code | symbol is attached | subjected to the same location and description is abbreviate | omitted.

  FIG. 4 is a plan view of a rice cooker according to Embodiment 2 of the present invention, and FIG. 5 is an exploded perspective view of a main part. The upper frame 61 has three guide roller mounting portions 63 that are equally disposed in the upper end opening. A guide roller 70 is rotatably attached to the bearing portion 62 of the guide roller attachment portion 63 via a shaft (shaft portion) 73 in the vertical direction (with the shaft 73 held horizontally as a rotation axis) (FIG. 5). An upper frame cap 64 formed of a heat resistant resin is engaged with the guide roller mounting portion 63 by a claw portion 65. The guide roller 70 is formed of a slidable resin and rotates with respect to the shaft 73. Reference numeral 71 denotes a silicon rubber pan detent provided so as to surround the outer peripheral portion of the guide roller 70. The pan detent 71 has a groove 72 that is parallel to the rotation direction of the guide roller 70 and has a V-shaped cross section. The V-shaped groove 72 is opened inward.

FIG. 6A is a cross-sectional view of the main part passing through the shaft when the pan is stored in the storage unit of the rice cooker according to Embodiment 2 of the invention, and FIG. 6B does not store the pan in the storage unit. It is principal part sectional drawing which passes along the shaft of time. When the pan 12 is stored in the storage unit 30, the three pan detents 71 are in contact with the pan 12 while being opened (FIG. 6A). Since the guide roller 70 rotates only in the vertical direction, the pan 12 is stored smoothly.
The induction heating rice cooker heats the pan 12 to a high temperature. In the induction heating rice cooker, a gap is provided between the pan 12 and the storage unit 30 so that the temperature of the storage unit 30 does not rise above a predetermined temperature. Since the temperature of the storage unit 30 is kept below a predetermined temperature, the storage unit 30 can be molded with a light and inexpensive resin. Usually, the pan 12 has a flange 121, and the position of the pan 12 is stabilized by placing the flange 121 of the pan 12 on the upper surface circumference of the storage unit 30. However, in the rice cooker of this invention which has the weight detection means 40, the detection body 43 becomes a structure which supports the whole weight of the pan 12, and the pan 12 is not stably arrange | positioned by the flange 121. As shown in FIG. In the present invention, the position of the pan 12 is also restricted in the horizontal direction by the three pan detents 71 and the posture is stabilized, so that the weight detection means 40 detects the weight of the pan 12 with high accuracy. Furthermore, since the distance between the induction heating coil 13 and the pan 12 is kept constant, the induction heating coil 13 heats the pan 12 appropriately and stably. The rice cooker of Embodiment 2 can exhibit excellent rice cooking performance. Further, when the user tries to remove the rice from the pan 12, the pan 12 does not rotate.
Note that at least three guide rollers 70 may be provided in the upper end opening of the upper frame 61.

<< Embodiment 3 >>
The rice cooker of Embodiment 3 of this invention is demonstrated using FIG.7 and FIG.8. The rice cooker according to the second embodiment has a configuration in which the guide roller 70 is pivotally supported by the guide roller mounting portion 63 of the upper frame 61. The rice cooker of the third embodiment has a configuration in which the guide roller 70 is pivotally supported by a guide roller base (spring member) 80 held by the guide roller mounting portion 63 (the bearing portion 62 of the upper frame 61 is not used). . Since the other structure is the same as the rice cooker (FIGS. 1-4) of Embodiment 2, the same code | symbol is attached | subjected to the same location and description is abbreviate | omitted. FIG. 7 is an exploded perspective view of main parts of the rice cooker according to Embodiment 3 of the present invention. FIG. 8A is a side view of the guide roller base when the pan is not stored in the storage portion of the rice cooker according to Embodiment 3 of the present invention, and FIG. It is a side view of the guide roller base at the time.

The guide roller base 80 is a spring member formed of an elastic resin. The guide roller base 80 includes a guide roller base fixing portion 81 that is sandwiched between the upper frame cap 64 and the upper frame 61 and is fixed, and a bearing portion 82 that rotatably supports the guide roller 70. The shaft 73 is fitted into the bearing portion 82.
When the pan 12 is stored in the storage unit 30, the three pan detents 71 are in contact with the pan 12 while being opened, and the guide roller base 80 is elastically deformed and pushed out toward the outside of the pan 12 (FIG. 8B). ). Since the guide roller 70 rotates in the vertical direction, the pan 12 is stored smoothly. In the rice cooker of the third embodiment, even if the size of the pan 12 varies in the manufacturing process, the guide roller base 80 is elastically deformed and the guide roller 70 is displaced according to the unevenness of the pan 12, so that the pan 12 is smooth. Can be stored. In the present invention, since the position of the pan 12 is regulated in the horizontal direction by the three pan stoppers 71 and the posture is stabilized, the weight detecting means 40 detects the weight of the pan 12 with high accuracy. Furthermore, since the distance between the induction heating coil 13 and the pan 12 is kept constant, the induction heating coil 13 heats the pan 12 appropriately and stably. The rice cooker of Embodiment 3 can exhibit excellent rice cooking performance. Further, when the user tries to remove the rice from the pan 12, the pan 12 does not rotate.
Note that at least three guide rollers 70 and guide roller bases 80 may be provided in the upper end opening of the upper frame 61.

  The rice cooker according to the present invention is useful as a rice cooker for home use or business use.

The side view in which the rice cooker of Embodiment 1- Embodiment 3 of this invention was notched partially The principal part exploded perspective view of the rice cooker of Embodiment 1- Embodiment 3 of this invention 3 (a) and 3 (b) show the pan bottom (solid line) in the pre-cooking step when 1-cooking rice is cooked with the rice cooker of Embodiments 1 to 3 and 5-cooking rice of the present invention. The temperature at the center of the cooked product (dashed line), FIGS. 3C and 3D are the conventional rice cookers that determine the amount of rice cooked in the cooking process, when cooking 1 go and 5 go cooking. Temperature of the pan bottom (solid line) and the center of the cooked food (dashed line) in the pre-cooking process The top view of the rice cooker of Embodiment 2 and Embodiment 3 of this invention The principal part disassembled perspective view of the rice cooker of Embodiment 2 of this invention. FIG. 6 (a) is a cross-sectional view of the main part passing through the shaft when the pan is stored in the storage unit of the rice cooker according to Embodiment 2 of the present invention, and FIG. 6 (b) stores the pan in the storage unit. Sectional view through the shaft when there is no The principal part exploded perspective view of the rice cooker of Embodiment 3 of this invention FIG. 8A is a side view of the guide roller base when the pan is not stored in the storage portion of the rice cooker according to Embodiment 3 of the present invention, and FIG. Side view of the guide roller base

Explanation of symbols

10 Body
DESCRIPTION OF SYMBOLS 12 Pan 13 Induction heating coil 14 Circuit board 16 Pan detection means 19 Cooked food 20 Lid 21 Base 30 Storage part 31 Coil base 32, 61 Upper frame 40 Weight detection means 41 Load cell (weight detection element)
42 Sensor stand (insulating material)
43 Batting cylinder (detector)
51 Spring 52 Temperature Detection Means 53 Lead Wire 54 Connector 55 Contact 62, 82 Bearing Portion 63 Guide Roller Mounting Portion 64 Upper Frame Cap 70 Guide Roller 71 Pan Stopper 72 Groove 73 Shaft (Shaft)
80 Guide roller base (spring member)
81 Guide roller base fixing part 121, 432 Flange 211 Thin plate 212, 411, 412, 422 Screw hole 413 Strain gauge 421 Recessed part 423 Cover cylinder fixing hole 424 Groove 431 Claw part 521 Brim

Claims (9)

A main body with an open top;
A pan that is detachably stored in the storage portion of the main body,
A lid that covers the storage part so as to be freely opened and closed;
Induction heating means for induction heating the pan;
A weight detection element that is directly or indirectly attached to the storage section, and a detection body that is directly or indirectly attached to the weight detection element and that is in contact with the substantially central portion of the outer bottom of the pan, A weight detection means for detecting the total weight of the pan and the food put in the pan by the weight detection element via a detector;
A controller that calculates the weight of the cooked food based on the output signal of the weight detection means, and controls the energization rate and / or the energization amount to the induction heating means according to the weight of the cooked food;
Rice cooker characterized by having. The rice cooker according to claim 1, wherein an insulating member connected to the weight detection element and the detection body is provided between the weight detection element and the detection body. 2. The rice cooker according to claim 1, further comprising a pan detection means for detecting whether or not the pan is stored in the storage portion at a substantially central portion of an outer bottom portion of the pan. 4. The rice cooker according to claim 1, wherein the detection body has a cylindrical shape, and includes temperature detection means for detecting the temperature of the pan inside thereof. 5. . The rice cooker according to claim 4, wherein the temperature detecting means is urged upward by an elastic body such that an upper surface of the temperature detecting means protrudes above the upper surface of the detector. The rice cooker according to any one of claims 1 to 5, wherein the weight detection element is a load cell or a piezoelectric element. At least three guide roller mounting portions for holding a guide roller that contacts the side surface of the pan and a bearing portion that rotatably supports the guide roller in the vertical direction are provided on the upper portion of the storage portion. The rice cooker according to any one of claims 1 to 6. A guide roller that contacts the side surface of the pan;
A spring member that includes a bearing portion that rotatably supports the guide roller in the vertical direction and that can be displaced in a direction orthogonal to the side surface of the pan;
At least three guide roller mounting portions provided at an upper portion of the storage portion and detachably holding the spring member;
The rice cooker according to any one of claims 1 to 6, characterized by comprising: 9. The guide roller according to claim 7, wherein the guide roller has a rubber pan detent having a groove portion having a V-shaped cross section parallel to a rotation direction of the guide roller on an outer peripheral portion thereof. The described rice cooker.

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