Rice cooker

Abstract

To obtain a rice cooker that can improve heating power by improving cooling performance for cooling a power supply board.SOLUTION: A rice cooker comprises: a main body having a cylindrical shape of which an upper end part and a lower end part are open; a bottom case covering the opening of the lower end part of the main body, and in which an intake port and an exhaust port are formed; an inner pot detachably housed inside the main body; a heating part arranged in the main body, and for heating the inner pot; a power supply board 20 arranged in the main body, and for driving the heating part; a heat dissipation fin 32 arranged on the power supply board; and a cooling fan 21 arranged in the intake port of the bottom case, and for blowing cooling air taken from the intake port, toward the heat dissipation fin and the power supply board. When a width direction X of the main body is defined as a first direction, a plurality of heat dissipation members of the heat dissipation fin are arranged in parallel at intervals in the first direction, and a width L1 of the cooling fan in the first direction is larger than a width L2 of the heat dissipation fin in the first direction.SELECTED DRAWING: Figure 13

Description

[Technical field]

[0001] The present disclosure relates to a rice cooker having a power supply board. [Background technology]

[0002] As a conventional example, there is a rice cooker that is provided with an air intake and a cooling fan on the bottom surface at the rear of the main body, and that cools a power supply board arranged at the rear of the main body (see, for example, Patent Document 1).

[0003] The rice cooker described in Patent Document 1 has an inner case provided in the main body, inside which a cylindrical bottomed inner pot that contains rice or other food to be heated is removably housed. The rice cooker described in Patent Document 1 has an induction heating coil that heats the bottom of the inner pot. The power supply board supplies power to the induction heating coil using power from an external power source such as a commercial power source. As a result, the inner pot receives an induced current from the induction heating coil and generates heat through electromagnetic induction. The heat generated heats and cooks the food contained inside the inner pot. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-75510 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the rice cooker described in Patent Document 1, when an attempt is made to increase the amount of heat generated by the induction heating coil, the amount of heat generated by the power supply board also increases at the same time, and the cooling cannot keep up with this, making it difficult to increase the heating power.

[0006] The present disclosure has been made to solve such problems, and aims to provide a rice cooker that can improve heating power by improving the cooling performance for cooling the power supply board. [Means for solving the problem]

[0007] The rice cooker according to the present disclosure comprises a main body having a cylindrical shape with upper and lower openings, a bottom case covering the opening at the lower end of the main body and having an air intake port and an exhaust port formed therein, an inner pot removably housed inside the main body, a heating unit disposed on the main body for heating the inner pot, a power supply board disposed on the main body for driving the heating unit, heat dissipation fins disposed on the power supply board, and a cooling fan disposed on the air intake port of the bottom case for blowing cooling air taken in from the air intake port towards the heat dissipation fins and the power supply board. A fin cover that covers the heat dissipation fins; When a width direction of the main body is defined as a first direction, the heat dissipation fin has a plurality of heat dissipation members arranged side by side at intervals in the first direction, and a width of the cooling fan in the first direction is larger than a width of the heat dissipation fin in the first direction. The fin cover has a first opening for taking in the cooling air taken in from the air intake by the cooling fan into the heat dissipation fins, a second opening for discharging the cooling air from the heat dissipation fins after the cooling air taken in from the first opening cools the heat dissipation fins, and a convex portion formed in a convex shape from an upper end to a lower end of the fin cover on an inner surface of the fin cover. It is something. Effect of the Invention

[0008] In the rice cooker according to the present disclosure, when the width direction of the main body is defined as a first direction, the width of the cooling fan in the first direction is made larger than the width of the heat dissipation fin in the first direction, increasing the wind power of the cooling fan and effectively utilizing the function of the heat dissipation fin to improve the cooling performance for cooling the power supply board. In this way, by improving the cooling performance, the power supply board can be cooled efficiently, so that even if the heating power of the rice cooker is increased, the temperature rise of the power supply board can be suppressed. As a result, it is possible to improve the heating power of the rice cooker. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view showing the appearance of a rice cooker according to a first embodiment. [Diagram 2] 1 is a cross-sectional view showing a configuration of a rice cooker according to a first embodiment. [Diagram 3] FIG. 1 is a perspective view showing a configuration of a rice cooker according to a first embodiment. [Figure 4] 2 is a perspective view showing the configuration of a bottom case provided in the rice cooker according to the first embodiment. FIG. [Diagram 5] 2 is a perspective view showing the configuration of a power supply board provided in the rice cooker according to the first embodiment. FIG. [Figure 6] 2 is a perspective view showing the configuration of a power supply board provided in the rice cooker according to the first embodiment. FIG. [Figure 7] 2 is a front view showing the front of a power supply board provided in the rice cooker according to the first embodiment. FIG. [Figure 8] 2 is a perspective view showing a power supply board provided in the rice cooker according to the first embodiment. FIG. [Figure 9] 2 is an explanatory diagram showing the positional relationship between a power supply board, heat dissipation fins, and a cooling fan in the rice cooker according to the first embodiment. FIG. [Figure 10] 2 is an explanatory diagram showing the positional relationship between a power supply board, heat dissipation fins, and a cooling fan in the rice cooker according to the first embodiment. FIG. [Figure 11] 2 is an explanatory diagram showing the positional relationship between a power supply board, heat dissipation fins, and a cooling fan in the rice cooker according to the first embodiment. FIG. [Figure 12] 2 is an explanatory diagram showing the positional relationship between a power supply board, heat dissipation fins, and a cooling fan in the rice cooker according to the first embodiment. FIG. [Figure 13] 4 is an explanatory diagram showing the size relationship in the width direction between the heat dissipation fins and the cooling fan in the rice cooker according to the first embodiment. FIG. [Figure 14] FIG. 2 is a perspective view showing the configuration of a fin cover in the rice cooker according to the first embodiment. [Figure 15] FIG. 2 is a perspective view showing the configuration of a fin cover in the rice cooker according to the first embodiment. [Figure 16] 4 is a plan view showing the configuration of a fin cover in the rice cooker according to the first embodiment. FIG. [Figure 17] FIG. 2 is a perspective view showing the configuration of a fin cover in the rice cooker according to the first embodiment. [Figure 18] FIG. 2 is a perspective view showing the configuration of a fin cover in the rice cooker according to the first embodiment. [Figure 19] 4 is a front view showing a rear portion of a fin cover provided in the rice cooker according to embodiment 1. FIG. [Figure 20] FIG. 20 is a partially enlarged view of FIG. [Figure 21] 4 is a perspective view showing a rear portion of a fin cover provided in the rice cooker according to embodiment 1. FIG. [Figure 22] FIG. 22 is a partially enlarged view of FIG. [Figure 23] 4 is an explanatory diagram showing the relationship in size between the width direction and the height direction of heat dissipation fins in the rice cooker according to the first embodiment. FIG. [Figure 24] 2, with the addition of arrows indicating the direction of cooling airflow. [Diagram 25] 7, with the addition of arrows indicating the direction of cooling airflow. [Figure 26] 20, with the addition of arrows indicating the direction of cooling airflow. [Figure 27] FIG. 3 is a cross-sectional view showing a method of arranging a cooling fan provided in the rice cooker according to the first embodiment. [Figure 28] FIG. 28 is a partially enlarged view of FIG. [Figure 29] FIG. 11 is a perspective view showing the configuration of a fin cover provided in a rice cooker according to a first variation of the first embodiment. [Diagram 30] 13 is a perspective view showing a state in which a fin cover is mounted on a power supply board in a rice cooker according to a first variation of the first embodiment. FIG. [Diagram 31] 10 is a plan view showing the configuration of a fin cover provided in a rice cooker according to a first variation of the first embodiment. FIG. [Diagram 32] 10 is a plan view showing the configuration of a fin cover provided in a rice cooker according to a first variation of the first embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the rice cooker according to the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the following embodiment, and various modifications can be made without departing from the spirit of the present disclosure. The present disclosure includes all combinations of possible configurations among the configurations shown in the following embodiment and its modified examples. In each drawing, the same reference numerals are the same or equivalent, and this is common throughout the entire specification. In each drawing, the relative dimensional relationship or shape of each component may differ from the actual one. In each drawing, Z is the height direction of the rice cooker, and Y is the depth direction of the rice cooker. X is the width direction of the rice cooker. The height direction Z is, for example, a vertical direction, and in the height direction Z, Z1 is the upward direction when the rice cooker is placed in the normal orientation, and Z2 is the downward direction. In the depth direction Y, Y1 is the front direction (or the front side) of the rice cooker, and Y2 is the rear direction (or the rear side) of the rice cooker. In addition, in the width direction X, X1 is the right direction (or right side) when the rice cooker is placed in the normal direction and viewed from the front, and X2 is the left direction (or left side). The width direction X is sometimes called the first direction. The height direction Z is sometimes called the second direction. The depth direction Y is sometimes called the third direction.

[0011] Embodiment 1 Fig. 1 is a perspective view showing the appearance of the rice cooker according to the first embodiment. Fig. 2 is a cross-sectional view showing the configuration of the rice cooker according to the first embodiment. Fig. 2 shows a cross-sectional shape when cut along a plane parallel to the YZ plane. As shown in Figs. 1 and 2, the rice cooker 100 has a main body 1 which is an outer case, an inner case 2 fixed inside the main body 1, an induction heating coil 3, a temperature sensor 4, and a bottom case 8.

[0012] The main body 1 forming the side of the rice cooker 100 has a cylindrical shape. The main body 1 may be rectangular in plan view, or may be circular or elliptical. Alternatively, the main body 1 may have a rectangular back side and a circular or semicircular front side in plan view. The upper and lower ends of the main body 1 are open. A bottom case 8 is provided at the lower end of the main body 1. The bottom case 8 is attached to the main body 1 so as to cover the open lower end of the main body 1. The main body 1 and the bottom case 8 form the outer shell of the rice cooker 100 having a bottomed cylindrical shape. The bottom case 8 is made of a synthetic resin such as PP (polypropylene). The main body 1 is made of a resin such as PC (polycarbonate) or ABS (acrylonitrile butadiene styrene). The main body 1 is not limited to a resin, and may be made of a metal member such as stainless steel.

[0013] The inner case 2 has a cylindrical shape with a bottom and an open upper end. The inner case 2 has a circular or substantially circular shape, or an elliptical shape in a plan view. The inner case 2 removably accommodates the inner kettle 5 described later.

[0014] The induction heating coil 3 is a coil for electromagnetic induction heating provided on the outer wall of the inner case 2. The induction heating coil 3 is arranged on the bottom of the inner case 2 and on the side near the bottom. The induction heating coil 3 is wound, for example, in a spiral shape. A high-frequency current is supplied to the induction heating coil 3 through, for example, a rectifier circuit and an inverter circuit provided on the power supply board 20. The induction heating coil 3 constitutes a "heating unit" that heats the inner pot 5. The "heating unit" is not limited to the induction heating coil 3, and may be of another configuration as long as it can heat the inner pot 5.

[0015] The temperature sensor 4 is provided on the lid 7, which will be described later. The lid 7 is attached to the main body 1 so as to be openable and closable, covering the open upper end of the main body 1. The temperature sensor 4 detects the temperature inside the inner pot 5. The temperature sensor 4 is arranged, for example, so as to pass through a through hole formed in the inner lid 7b constituting the lid 7. The number of temperature sensors is not limited to one, and in addition to the temperature sensor 4 on the lid side, a temperature sensor on the pot bottom side may be provided at the bottom of the inner case 2.

[0016] Furthermore, the rice cooker 100 has an inner pot 5, a hinge portion 6, a lid body 7, and a lid heater 9.

[0017] The inner pot 5 has a bottomed cylindrical shape with an open upper end. The inner pot 5 has a circular or substantially circular shape, or an elliptical shape in a plan view. The inner pot 5 is detachably housed in the inner case 2 provided in the main body 1. The inner pot 5 houses the food to be heated, such as rice and water, inside. The inner pot 5 receives an induced current from the induction heating coil 3, and the inner pot 5 itself heats up due to electromagnetic induction. The food to be heated in the inner pot 5 is heated and cooked by the heat. A flange portion 50 is provided on the periphery of the opening of the inner pot 5. The flange portion 50 is provided around the entire circumference of the opening along the circumferential direction of the opening of the inner pot 5. As shown in FIG. 2, the flange portion 50 has an L-shaped cross section. The flange portion 50 is composed of a horizontal portion 50a extending horizontally from the periphery of the opening of the inner pot 5, and a vertical portion 50b standing upright from the outer periphery of the horizontal portion 50a in the upward direction Z1. The horizontal part 50a of the flange part 50 extends from the peripheral part of the opening of the inner hook 5 toward the outside of the inner hook 5 in the radial direction of the inner hook 5. That is, the horizontal part 50a is provided so as to be parallel to the XY plane. The horizontal part 50a has a doughnut shape in a plan view. The vertical part 50b is provided on the outer peripheral edge of the horizontal part 50a. The vertical part 50b stands upright from the outer peripheral edge of the horizontal part 50a toward the upward direction Z1. The extending direction of the vertical part 50b and the extending direction of the horizontal part 50a cross each other, for example, are perpendicular to each other.

[0018] The hinge portion 6 is provided on the back surface of the main body 1. The lid body 7 is attached to the main body 1 in an openable and closable manner via the hinge portion 6. The lid body 7 is composed of an outer lid 7a, an inner lid 7b, and a lid gasket (not shown).

[0019] The outer lid 7a is provided to the main body 1 so as to be openable and closable via the hinge portion 6. The outer lid 7a is disposed so as to cover the opening at the upper end of the main body 1.

[0020] The inner lid 7b is a lid that covers the inner pot 5 and is disposed inside the outer lid 7a. A lid packing (not shown) that is a sealing material is attached to the periphery of the inner lid 7b. The lid packing is made of an elastic material such as silicone rubber. The lid packing ensures the sealing between the flange portion 50 of the inner pot 5 and the inner lid 7b. The inner lid 7b is attached to the inner wall surface of the outer lid 7a by the user when the outer lid 7a is in an open state. As a result, the outer lid 7a and the inner lid 7b are connected to each other, and when the outer lid 7a is opened or closed, the inner lid 7b is opened and closed simultaneously in conjunction with the outer lid 7a. The inner lid 7b and the outer lid 7a constitute the lid body 7 that covers the inner pot 5. The inner lid 7b is detachably attached to the outer lid 7a, and when the inner lid 7b is washed, the inner lid 7b is removed from the outer lid 7a by the user.

[0021] The outer lid 7a is disposed on the upper part of the inner lid 7b so as to cover the inner lid 7b. The outer lid 7a is provided on the main body 1 so as to be openable and closable via the hinge portion 6. When the outer lid 7a is in the closed state, it is disposed so as to cover the opening of the main body 1 and the opening of the inner pot 5. When the outer lid 7a is in the open state, the food to be heated in the inner pot 5 can be put in and taken out. Furthermore, when the outer lid 7a is in the open state, the inner pot 5 itself can be taken in and out of the main body 1.

[0022] The lid heater 9 is provided inside the lid body 7. As described above, since the induction heating coil 3 is arranged below the inner pot 5, the temperature of the upper part of the inner pot 5 tends to be lower than the temperature of the lower part of the inner pot 5 during the rice cooking operation and the warming operation of the rice cooker 100. Therefore, in the first embodiment, the lid heater 9 is arranged inside the lid body 7. The lid heater 9 heats the upper part of the inner pot 5. By using the induction heating coil 3 and the lid heater 9 together, it is possible to suppress temperature unevenness in the inner pot 5 and the adhesion of sauce to the inner lid 7b. This allows the rice to be cooked deliciously and the deliciousness of the rice can be maintained even during warming.

[0023] Furthermore, the rice cooker 100 has a power supply board 20, a cooling fan 21, and heat dissipation fins 32 (see FIG. 5). As shown in FIG. 2, the power supply board 20 is disposed on the rear part of the main body 1. The power supply board 20 stands in the Z direction. The power supply board 20 is disposed so that its main surface (i.e., the mounting surface) is parallel or approximately parallel to the height direction Z and perpendicular or approximately perpendicular to the XY plane. The power supply board 20 supplies a high-frequency current to the induction heating coil 3 using power from an external power source such as a commercial power source to drive the induction heating coil 3.

[0024] The heat dissipation fins 32 are disposed on the power supply board 20. The heat dissipation fins 32 dissipate heat from heat-generating components mounted on the power supply board 20, thereby cooling the power supply board 20. The heat dissipation fins 32 will be described later. As shown in FIG. 2, the cooling fan 21 is disposed below the power supply board 20. The cooling fan 21 is disposed opposite an intake port 30, which will be described later, formed in the bottom case 8. The cooling fan 21 blows outside air (cooling air) taken in from the intake port 30 toward the power supply board 20 and the heat dissipation fins 32, thereby cooling the power supply board 20 and the heat dissipation fins 32.

[0025] The bottom case 8 is provided with an air intake 30, an exhaust 31, and a cord reel 22. As described above, the air intake 30 takes in cooling air from the outside to cool the power supply board 20 and the heat dissipation fins 32. The exhaust 31 discharges the cooling air to the outside after cooling the power supply board 20 and the heat dissipation fins 32. The cord reel 22 houses a power cord having one end connected to a power plug 23. The other end of the power cord is connected to the power supply board 20. The power plug 23 is detachably connected to an external power source such as a commercial power source.

[0026] As shown in Figs. 1 and 2, an operation display unit 24 is provided on the top surface of the lid 7. The operation display unit 24 is provided with switches, various buttons, and a display screen such as a display. The user can execute each operation of the rice cooker 100 by operating the various buttons on the operation display unit 24. The display screen also displays the cooking status and the contents of the cooking menu set by the user's operation. An operation board 25 is connected to the operation display unit 24. The contents of the operation on the operation display unit 24 are transmitted to a control unit (not shown) via the operation board 25.

[0027] The control unit receives the detection results of the temperature sensor 4 and other sensors. In addition, various settings such as a cooking menu input by the user to the operation display unit 24 are transmitted to the control unit. The control unit controls the operations of the power supply board 20 and the cooling fan 21 based on the detection results of the temperature sensor 4 and other sensors and the various settings input to the operation display unit 24. The control unit is composed of, for example, a processor and a memory. Each function of the control unit is realized by the processor executing a program stored in the memory.

[0028] Next, a description will be given of the operation of the rice cooker 100. When operating the rice cooker 100, a user first puts ingredients such as rice and water into the inner pot 5. These ingredients are the items to be cooked by the rice cooker 100.

[0029] Thereafter, when the user grasps the flange portion 50 of the inner pot 5, places the inner pot 5 on the inner case 2, and closes the outer lid 7a, the lid gasket of the inner lid 7b is pressed against the flange portion 50 of the inner pot 5, hermetically sealing the internal space of the rice cooker 100.

[0030] As described above, the outer lid 7a is provided rotatably around the hinge portion 6, and opens and closes the opening at the upper end of the main body 1. The outer lid 7a is always biased in the opening direction by the hinge portion 6. The outer lid 7a in the closed state is locked to the main body 1 by, for example, a latch portion (not shown) provided on the front portion of the outer lid 7a. When the user presses the lid opening button (not shown), the latch portion that locks the outer lid 7a to the main body 1 is released, and the biasing force of the hinge portion 6 opens the outer lid 7a.

[0031] Next, the user selects a rice cooking menu on the operation display unit 24 and turns on the switch of the operation display unit 24, thereby starting rice cooking in the rice cooker 100. Note that, although FIG. 1 shows an example in which the operation display unit 24 is installed on the outer lid 7a, the present invention is not limited to this case, and the operation display unit 24 may be installed on the front part of the main body 1. Furthermore, the operation display unit 24 may be provided in a location other than the main body 1. That is, if the rice cooker 100 has a remote controller (not shown), the operation display unit 24 may be provided on the remote controller. Alternatively, the operation display unit 24 may be provided as an application program on a portable terminal such as a smartphone carried by the user.

[0032] When cooking is started in the rice cooker 100, a high-frequency current is supplied to the induction heating coil 3 from the power supply board 20. This generates a high-frequency magnetic field from the induction heating coil 3, exciting the surface of the inner pot 5 that faces the heating coil and is magnetically coupled with the induction heating coil 3 (i.e., the bottom surface of the inner pot 5), inducing an eddy current in the bottom surface of the inner pot 5. This eddy current and the resistance of the inner pot 5 generate Joule heat, causing the bottom surface of the inner pot 5 to heat up, thereby heating the food to be cooked.

[0033] Next, the configuration of the bottom case 8 will be described with reference to Figs. 3 and 4. Fig. 3 is a perspective view showing the configuration of the rice cooker according to the first embodiment. Fig. 4 is a perspective view showing the configuration of the bottom case provided in the rice cooker according to the first embodiment. Fig. 3 shows the rice cooker 100 viewed from the downward direction Z2. Therefore, please note that the orientations of the upward direction Z1 and the downward direction Z2 are reversed from those in Fig. 1. Also, Fig. 4 shows the bottom case 8 removed from the main body 1 viewed from the upward direction Z1. In Fig. 4, the orientations of the upward direction Z1 and the downward direction Z2 are the same as those in Fig. 1.

[0034] As described above, the bottom case 8 is attached to the main body 1 so as to cover the opening at the lower end of the main body 1. As shown in FIG. 3 and FIG. 4, the above-mentioned cord reel 22 is provided in the center of the bottom case 8. In addition, in the depth direction Y of the bottom case 8, an air intake 30 is provided in an area on the back side (closer to the back direction Y2) of the main body 1. In addition, in the bottom case 8, an exhaust port 31 is provided in an area on the front side (closer to the front direction Y1) of the main body 1. In addition, as shown in FIG. 2 and FIG. 4, a cooling fan 21 is provided above the air intake 30. Both the air intake 30 and the exhaust port 31 have multiple slits that penetrate the plate thickness of the bottom case 8. The inside and outside of the bottom case 8 are in communication through these slits, and the airflow of the cooling air can flow through these slits with reduced pressure loss. By providing multiple slits in the air intake 30 and the exhaust port 31, it is possible to prevent foreign matter such as dust from entering the main body 1 from the outside through the air intake 30 and the exhaust port 31.

[0035] Next, the configuration of the power supply board 20 and the heat dissipation fins 32 will be described with reference to FIG. 5 and FIG. 6. FIG. 5 and FIG. 6 are perspective views showing the configuration of the power supply board provided in the rice cooker according to the first embodiment. FIG. 5 shows the power supply board 20 viewed from the power supply board surface portion 201 side, which is the mounting surface on which the components 205 are mounted. Hereinafter, the power supply board surface portion 201 side will be referred to as the front side of the power supply board 20. FIG. 6 shows the power supply board 20 viewed from the rear portion 204 side of the power supply board 20. At least one of the multiple components 205 mounted on the power supply board surface portion 201 is a heat-generating component such as a semiconductor switching element that constitutes an inverter circuit and a rectifier circuit. At least another of the multiple components 205 mounted on the power supply board surface portion 201 is a consumable component such as an electrolytic capacitor that is damaged by heat and is likely to have a heat effect on the life of the component. Since a failure of the power supply board 20 leads to a failure of the entire rice cooker 100, it is important for the rice cooker 100 to improve the cooling performance of the power supply board 20.

[0036] As shown in FIG. 5 and FIG. 6, the power supply board 20 has a box-like shape as a whole. The power supply board 20 has a power supply board surface portion 201 on which the components 205 are mounted, an upper surface portion 202, a pair of side portions 203, and a rear portion 204. The lower end of the power supply board 20 is open. In the opening of the lower end of the power supply board 20, a cooling fan 21 is disposed, as shown in FIG. 9 and FIG. 10 described later. The power supply board 20 is also configured with a rear member 200 having an open front and a plate-like rear. The front side surface of the rear member 200 is the power supply board surface portion 201 described above, and the rear side surface of the rear member 200 is the rear portion 204 described above. In this way, the power supply board 20 has a box-like shape with at least a portion open, and the power supply board surface portion 201, which is the mounting surface, forms a part of the box-like shape of the power supply board 20. As shown in FIG. 5, a heat dissipation fin 32 is disposed in the center of the power supply board surface portion 201 of the power supply board 20. The heat dissipation fin 32 is disposed in the center of the power supply board surface portion 201 in the width direction X, but is disposed on the downward direction Z2 side of the power supply board surface portion 201 in the height direction Z. Therefore, a space is formed between the upper end of the heat dissipation fin 32 and the upper surface portion 202 of the power supply board 20. In addition, a space is also formed between the side portion of the heat dissipation fin 32 and the side portion 203 of the power supply board 20. That is, a U-shaped space is formed so as to cover the upper and side portions of the heat dissipation fin 32, and cooling air flows through the space (see arrow D in FIG. 25). The flow of the cooling air will be described later.

[0037] The heat dissipation fin 32 has a plurality of heat dissipation members 32a arranged side by side at a distance W2 (see FIG. 31) in the width direction X, and a base 32b to which the heat dissipation members 32a are attached in a cantilevered manner. The base 32b has, for example, a rectangular plate shape. The plurality of heat dissipation members 32a protrude from the base 32b toward the back direction Y2 in the depth direction Y. The plurality of heat dissipation members 32a are arranged to be parallel to each other. Each of the heat dissipation members 32a has a plate shape. The longitudinal direction of the heat dissipation members 32a extends along the height direction Z, and the lateral direction of the heat dissipation members 32a extends along the depth direction Y. The heat dissipation members 32a and the base 32b are arranged in directions that intersect with each other. The heat dissipation members 32a and the base 32b are, for example, perpendicular to each other. The heat dissipation fins 32 are attached to the power supply board surface 201 of the power supply board 20 by means of fixtures 206 (see FIG. 7) such as screws. Therefore, in the center portion of the heat dissipation fins 32 in the width direction X, the interval W1 at which the heat dissipation members 32a are arranged is larger than the interval W2 in other portions in order to ensure a space for arranging the fixtures 206. The heat dissipation fins 32 are made of a metal having high thermal conductivity, such as aluminum.

[0038] FIG. 7 is a front view showing the front of the power supply board provided in the rice cooker according to the first embodiment. FIG. 8 is a perspective view showing the power supply board provided in the rice cooker according to the first embodiment. FIG. 7 and FIG. 8 show the state in which the power supply board 20 is mounted on the main body 1 of the rice cooker 100. In FIG. 7 and FIG. 8, for the purpose of explanation, a part of the inside of the main body 1 is shown in a see-through manner. As shown in FIG. 7 and FIG. 8, the power supply board 20 is disposed on the rear part of the main body 1. Below the power supply board 20, a cooling fan 21 is disposed. Below the cooling fan 21, an intake port 30 provided in the bottom case 8 is provided. Also, as shown in FIG. 7, the heat dissipation fin 32 is attached to the power supply board surface part 201 of the power supply board 20 by a mounting fixture 206 such as a screw.

[0039] Fig. 9 to Fig. 12 are explanatory diagrams showing the positional relationship of the power supply board, heat dissipation fins, and cooling fan in the rice cooker according to the first embodiment. Fig. 9 shows the state when viewed from the front side of the power supply board 20, and Fig. 10 shows the state when viewed from the back side of the power supply board 20. Fig. 11 is a perspective view showing a cross section of the power supply board 20 cut along the XY plane passing through point A in Fig. 9. Fig. 12 is a plan view showing a cross section of the power supply board cut along the XY plane passing through point A in Fig. 9. Point A is a point located downward Z2 from the center of the power supply board 20 in the height direction Z.

[0040] The back member 200, which is composed of the power supply board surface portion 201 and the back portion 204 of the power supply board 20, is disposed in the center of the cooling fan 21 in the depth direction Y in a plan view, as shown in FIG. 12. The back member 200 of the power supply board 20 is formed in a plate shape as a whole, as shown in FIG. 10, and has a rectangular shape when viewed from the back side. The back member 200 extends along the width direction X in a plan view, as shown in FIG. 12. The back member 200 is erected from the upper surface of the cooling fan 21 toward the upward direction Z1, as shown in FIG. 10. The cooling fan 21 has a rectangular shape in a plan view, as shown in FIG. 12. The back member 200 of the power supply board 20 is disposed so as to cross the center of the cooling fan 21 in the Y direction in the X direction, as shown in FIG. The cooling fan 21 blows the outside air (cooling air) sucked in from the intake port 30 toward the power supply board 20 and the heat dissipation fins 32. The cooling air blown by the cooling fan 21 hits both the power board surface portion 201 and the back surface portion 204 of the power board 20. The flow of the cooling air will be described in detail later.

[0041] FIG. 13 is an explanatory diagram showing the size relationship in the width direction between the heat dissipation fin and the cooling fan in the rice cooker according to the first embodiment. As shown in FIG. 13, both the cooling fan 21 and the heat dissipation fin 32 have a rectangular shape when viewed from the front. In this case, the size of the cooling fan 21 in the width direction X is set to width L1, and the size of the heat dissipation fin 32 in the width direction X is set to width L2. As shown in FIG. 13, the width L1 of the cooling fan 21 is larger than the width L2 of the heat dissipation fin 32. In a conventional rice cooker, the width of the cooling fan and the width of the heat dissipation fin are the same. In the first embodiment, a cooling fan 21 larger in size than the heat dissipation fin 32 is used so that the width L1 of the cooling fan 21 is larger than the width L2 of the heat dissipation fin 32. In general, the larger the size of the cooling fan 21, the larger the volume of the cooling air taken in by the cooling fan 21 from the air intake 30. This improves the cooling performance for cooling the power supply board 20.

[0042] Figs. 14 and 15 are perspective views showing the configuration of a fin cover in the rice cooker according to the first embodiment. Fig. 16 is a plan view showing the configuration of a fin cover in the rice cooker according to the first embodiment. As shown in Figs. 14 to 16, rice cooker 100 has fin cover 33 that covers heat dissipation fins 32. Fin cover 33 is arranged so as to cover heat dissipation fins 32, and is fixed to power supply board surface portion 201 of power supply board 20. Specifically, as shown in Fig. 14, an opening on the front side of power supply board 20 and an opening of fin cover 33 are arranged to face each other, and as shown in Figs. 15 and 16, fin cover 33 is attached so as to cover heat dissipation fins 32.

[0043] 17 and 18 are perspective views showing the configuration of the fin cover in the rice cooker according to the first embodiment. FIG. 17 shows the state of fin cover 33 as viewed from the rear portion 330 side, and FIG. 18 shows the state of fin cover 33 as viewed from the front side. As shown in FIGS. 17 and 18, fin cover 33 has rear portion 330 and a pair of side portions 331. Side portions 331 are arranged facing each other. Side portions 331 extend in height direction Z. In addition, rear portion 330 also extends in height direction Z. Fin cover 33 has a box shape as a whole, and upper end portion 334, lower end portion 335, and front portion are open. Rear portion 330 and side portion 331 are both rectangular plate-shaped members. Rear portion 330 and side portion 331 are adjacently arranged and joined. Rear portion 330 and side portion 331 are arranged in directions intersecting each other. The rear portion 330 and the side portion 331 are, for example, perpendicular to each other. Therefore, the upper end portion 334 of the fin cover 33 has a U-shape in a plan view. In addition, a tapered portion 332 is provided at the lower end of each of the side portions 331. The tapered portions 332 are arranged so as to be inclined with respect to the height direction Z. The tapered portions 332 are formed in a tapered shape so that the distance between them gradually decreases as they move upward in the Z1 direction. In other words, the tapered portions 332 are inclined so as to spread in a direction away from each other as they move downward in the Z2 direction. That is, the tapered portions 332 are formed so as to spread toward the outside of the fin cover 33 as they move downward in the Z2 direction. The rear portion 330 is joined to the side portion 331 and the tapered portion 332. Therefore, the lower end region 330a of the rear portion 330 gradually increases in size in the width direction X in an inverse tapered manner as it moves downward in the Z2 direction in accordance with the tapered portion 332. That is, lower end region 330a of rear surface portion 330 has a trapezoidal shape with an upper side shorter than the lower side. As shown in Fig. 17, space 337 is formed inside fin cover 33. Heat dissipation fins 32 are housed in space 337, as shown in Figs. 14 to 16. Furthermore, as shown in Figs. 17 and 18, fin cover 33 is provided with protrusions 336 for fixing fin cover 33 to power supply board 20, as necessary.

[0044] FIG. 19 is a front view showing a rear part of the fin cover provided in the rice cooker according to the first embodiment. FIG. 20 is a partially enlarged view of FIG. 19. FIG. 19 and FIG. 20 show a state in which the fin cover 33 is mounted on the main body 1 of the rice cooker 100. In FIG. 19 and FIG. 20, a part of the configuration is shown in a see-through manner for the purpose of explanation. As shown in FIG. 2 above, the power supply board 20 and the fin cover 33 are actually arranged inside the main body 1 and are not exposed to the outside. The fin cover 33 is arranged so as to cover the heat dissipation fins 32 (see FIG. 9) and is fixed to the power supply board surface portion 201 of the power supply board 20. As shown in FIG. 19 and FIG. 20, the fin cover 33 is arranged in the center of the power supply board surface portion 201 of the power supply board 20 so as to cover the heat dissipation fins 32. The fin cover 33 is arranged in the center in the width direction X, but is arranged on the downward direction Z2 side of the power supply board surface portion 201 in the height direction Z.

[0045] FIG. 21 is a perspective view showing a rear part of the fin cover provided in the rice cooker according to the first embodiment. FIG. 22 is a partially enlarged view of FIG. 21. In FIG. 21 and FIG. 22, a part of the configuration is shown in a see-through manner for the purpose of explanation. As shown in FIG. 22, the fin cover 33 has a first opening 40 that takes in the cooling air taken in by the cooling fan 21 into the power supply board 20. Furthermore, the fin cover 33 has a second opening 41 through which the cooling air taken in from the first opening 40 is discharged after cooling the heat dissipation fin 32. The first opening 40 is composed of the lower end 335 of the fin cover 33 shown in FIG. 17 and FIG. 18, and the second opening 41 is composed of the upper end 334 of the fin cover 33 shown in FIG. 17 and FIG. 18. Both the first opening 40 and the second opening 41 have a rectangular shape in a plan view. In this case, if the opening area of ​​the first opening 40 is defined as opening area R1 and the opening area of ​​the second opening 41 is defined as opening area R2, the opening area R2 of the second opening 41 is smaller than the opening area R1 of the first opening 40, as shown in FIG. 22.

[0046] 20 and 22, the first opening 40 of the fin cover 33 is formed to match the width of the cooling fan 21. Therefore, the size of the first opening 40 of the fin cover 33 in the width direction X is the same as the width L1 (see FIG. 13) of the cooling fan 21. As a result, the cooling air discharged from the large-diameter cooling fan 21 is efficiently taken into the fin cover 33 from the first opening 40 and flows into the heat dissipation fins 32. Furthermore, since the cooling fan 21 is covered by the fin cover 33 on the power supply board surface portion 201 side of the power supply board 20, it is possible to prevent the cooling air from returning to the intake surface side of the cooling fan 21. This makes it possible to eliminate loss of the cooling air.

[0047] On the other hand, the second opening 41 of the fin cover 33 is formed to match the width of the heat dissipation fin 32 as shown in FIG. 20 and FIG. 22. Therefore, the size of the second opening 41 of the fin cover 33 in the width direction X is the same as the width L2 (see FIG. 13) of the heat dissipation fin 32. That is, the side surface portion 331 of the fin cover 33 is arranged along the side surface portion of the heat dissipation fin 32 in the width direction X. This makes it possible to suppress the cooling air from passing through a space away from the heat dissipation member 32a of the heat dissipation fin 32. If it is assumed that the second opening 41 has the same opening area as the first opening 40, in that case, a space is formed between the side surface portion of the heat dissipation fin 32 in the width direction X and the side surface portion 331 of the fin cover 33. In that case, a part of the cooling air passes through a space away from the heat dissipation member 32a of the heat dissipation fin 32. In that case, the heat exchange efficiency between the cooling air and the heat dissipation member 32a is reduced. Therefore, in the first embodiment, in order to prevent a space from being generated between the side surface portion in the width direction X of the heat dissipating fin 32 and the side surface portion 331 of the fin cover 33, the second opening 41 of the fin cover 33 is formed to match the width of the heat dissipating fin 32. This makes it possible to prevent the cooling air from passing through a space away from the heat dissipating member 32a of the heat dissipating fin 32 inside the fin cover 33, and makes it possible to efficiently apply the airflow of the cooling air to the heat dissipating member 32a of the heat dissipating fin 32.

[0048] In this manner, in the first embodiment, a fin cover 33 is provided to cover the heat dissipation fins 32. The fin cover 33 has a first opening 40 through which the cooling air taken in from the cooling fan 21 is taken into the heat dissipation fins 32, and a second opening 41 through which the cooling air taken in from the first opening 40 is discharged after cooling the heat dissipation fins 32. In this manner, the fin cover 33 covering the heat dissipation fins 32 has the first opening 40 and the second opening 41, so that an air passage through which the cooling air flows is formed between the first opening 40 and the second opening 41. As a result, the airflow of the cooling air discharged from the cooling fan 21 flows along the heat dissipation member 32a of the heat dissipation fins 32, so that the cooling air can be efficiently applied to the heat dissipation member 32a of the heat dissipation fins 32. This can further improve the heat dissipation performance of the power supply board 20.

[0049] FIG. 23 is an explanatory diagram showing the relationship between the width and height of the heat dissipation fins in the rice cooker according to the first embodiment. As shown in FIG. 23, the heat dissipation fins 32 have a rectangular shape when viewed from the front. In this case, the size of the heat dissipation fins 32 in the width direction X is defined as width L2, and the size of the heat dissipation fins 32 in the height direction Z is defined as height H1. As shown in FIG. 23, the height H1 of the heat dissipation fins 32 is greater than the width L2 of the heat dissipation fins 32. Most of the heat of the power supply board 20 is dissipated by heat exchange between the heat dissipation member 32a of the heat dissipation fins 32 and the cooling air. In addition, the cooling air flows along the height direction Z. Therefore, by increasing the height H1 of the heat dissipation fins 32, the heat exchange surface where heat exchange between the heat dissipation member 32a of the heat dissipation fins 32 and the cooling air is performed becomes longer, and the heat exchange efficiency is improved.

[0050] Next, the flow direction of the cooling air will be described with reference to Fig. 24 and Fig. 25. Fig. 24 is a diagram in which arrows indicating the flow direction of the cooling air are added to Fig. 2. Fig. 25 is a diagram in which arrows indicating the flow direction of the cooling air are added to Fig. 7.

[0051] As shown in FIG. 24, more than half of the cooling air generated by driving the cooling fan 21 flows into the fin cover 33, and the remaining cooling air flows toward the induction heating coil 3. The cooling air that has flowed into the fin cover 33 rises inside the heat dissipation fins 32 while cooling the heat dissipation member 32a of the heat dissipation fins 32, as shown by arrow B in FIG. 24, and is discharged into the power supply board 20 from the second opening 41 at the upper end of the fin cover 33. Then, the cooling air flows inside the power supply board 20 while cooling the components 205 (see FIG. 25) mounted on the power supply board 20, and flows from the lower opening of the power supply board 20 toward the center of the bottom case 8. The cooling air is then discharged to the outside of the rice cooker 100 from the exhaust port 31 formed in the bottom case 8.

[0052] On the other hand, as shown by arrows C1 and C2 in FIG. 24, the cooling air that flows toward the induction heating coil 3 flows upward in a "part" and flows horizontally in a "other part". The "part" that flows upward rises through the space between the inner case 2 and the rear part 204 of the power supply board 20 as an air passage, as shown by arrow C1, and hits the inner lid 7b. The cooling air then flows into the gap between the main body 1 and the inner case 2 of the rice cooker 100. Then, the cooling air absorbs heat from the induction heating coil 3 that enters the gap and is discharged to the outside of the rice cooker 100 from the exhaust port 31 formed in the bottom case 8. The cooling air of the "other part" that flows horizontally flows into the space between the bottom surface of the inner case 2 and the bottom case 8 and around the bottom surface of the inner case 2, as shown by arrow C2 in FIG. 24. The cooling air cools the induction heating coil 3 and the cord reel 22 and is discharged to the outside of the rice cooker 100 from the exhaust port 31 formed in the bottom case 8.

[0053] FIG. 25 shows the direction of flow of the cooling air inside the power supply board 20 described with reference to FIG. 24 with arrows. The cooling fan 21 generates the cooling air flowing in the upward direction Z1 by being driven. The cooling air flowing in the upward direction Z1 flows toward the heat dissipation member 32a of the heat dissipation fin 32 (see FIG. 11 and FIG. 12) as shown by the outlined arrow B in FIG. 25. As a result, the cooling air passes through the inside of the heat dissipation fin 32, thereby cooling the heat dissipation member 32a of the heat dissipation fin 32. The cooling air flowing in the upward direction Z1 inside the heat dissipation fin 32 is discharged into the inside of the power supply board 20 from the second opening 41 (see FIG. 22) of the fin cover 33. Then, as shown by the arrow D in FIG. 25, the cooling air hits the upper surface portion 202 of the power supply board 20 and spreads toward the left side surface portion 203 and the right side surface portion 203 of the power supply board 20. After that, the cooling air flows in the downward direction Z2 inside the power supply board 20. The cooling air flowing in the downward direction Z2 flows through a gap at the bottom of the power supply board 20 toward the center of the bottom case 8 of the rice cooker 100. The cooling air that has flowed toward the center of the bottom case 8 flows toward the induction heating coil 3 provided in the inner pot 5 and cools the induction heating coil 3. It is then exhausted to the outside of the rice cooker 100 from the exhaust port 31 formed in the bottom case 8.

[0054] Next, the cooling air flowing along the fin cover 33 will be described with reference to Fig. 26. Fig. 26 is a diagram in which arrows indicating the flow direction of the cooling air are added to Fig. 20. Although Fig. 25 above shows a state in which the fin cover 33 is not shown for the sake of explanation, the fin cover 33 is attached to the heat dissipation fins 32. Therefore, the cooling air flows along the fin cover 33.

[0055] First, the flow of the cooling air inside the fin cover 33 will be described. As described above with reference to FIG. 22, the opening area R1 of the first opening 40 of the fin cover 33 is larger than the opening area R2 of the second opening 41. A tapered portion 332 is provided at the lower end of the side portion 331 of the fin cover 33. Therefore, as shown by the arrow B in FIG. 26, the cooling air taken into the power supply board 20 by the cooling fan 21 flows along the inner wall of the tapered portion 332 of the fin cover 33. At this time, the air path of the cooling air is gradually narrowed by the inner wall of the tapered portion 332 of the fin cover 33 as it moves in the upward direction Z1. This increases the flow rate of the cooling air. In this way, the tapered portion 332 of the fin cover 33 increases the flow rate of the cooling air, so that the cooling air can be efficiently applied to the heat dissipation fins 32. In this way, the tapered portion 332 can increase the flow rate of the cooling air flowing through the power supply board 20, thereby improving the cooling efficiency.

[0056] Next, the flow of the cooling air outside the fin cover 33 will be described. As shown by the arrow D in FIG. 26, the cooling air flowing out from the second opening 41 at the upper end of the fin cover 33 flows along the outer wall of the side portion 331 of the fin cover 33. After that, the cooling air flows along the outer wall of the tapered portion 332 of the fin cover 33. The tapered portions 332 expand in a direction away from each other as they move toward the downward direction Z2 of the height direction Z. In this way, the cooling air flows along the outer wall of the tapered portion 332, so that the cooling air flows so as to expand to the left and right as shown in FIG. 26. As a result, the cooling air is more likely to flow toward the center part of the bottom case 8 of the rice cooker 100 from the gap at the bottom of the power supply board 20. The cooling air that flows toward the center part of the bottom case 8 is discharged to the outside of the rice cooker 100 from the exhaust port 31 formed in the bottom case 8. In this way, by providing the tapered portion 332, the cooling air flowing outside the fin cover 33 can be guided, thereby improving the cooling efficiency.

[0057] Next, a method for arranging cooling fan 21 in rice cooker 100 according to embodiment 1 will be described with reference to Fig. 27 and Fig. 28. Fig. 27 is a cross-sectional view showing a method for arranging cooling fans provided in the rice cooker according to embodiment 1. Fig. 28 is a partially enlarged view of Fig. 27.

[0058] In the first embodiment, as shown in Figures 27 and 28, the cooling fan 21 is positioned so that the blowing direction E of the cooling air is inclined in the direction hitting the power supply board surface portion 201 of the power supply board 20 rather than in a direction parallel to the power supply board surface portion 201 of the power supply board 20.

[0059] As shown in FIG. 28, the cooling fan 21 is disposed so that the blowing direction E of the cooling air is inclined by an angle θ toward the direction of hitting the power supply board surface portion 201 from the direction parallel to the height direction Z. Specifically, the end 21a of the cooling fan 21 on the power supply board surface portion 201 side is disposed on the upper Z1 side from the plane parallel to the XY plane passing through the center part of the cooling fan 21. Also, the end 21b of the cooling fan 21 on the opposite side to the power supply board surface portion 201 side is disposed so that it is on the lower Z2 side from the plane parallel to the XY plane passing through the center part of the cooling fan 21. As a result, the cooling fan 21 is disposed so that the end 21a on the rear side of the main body 1 is higher than the end 21b on the front side, as shown in FIG. 28. In this way, the end 21a of the cooling fan 21 on the power supply board surface portion 201 side is disposed higher in the height direction Z than the end 21b of the cooling fan 21 on the opposite side to the power supply board surface portion 201 side. The ends 21a and 21b are opposite ends of the cooling fan 21 in the depth direction Y. The ends 21a and 21b are disposed opposite to each other (see FIGS. 11 and 12).

[0060] According to the first embodiment, as shown in Figures 27 and 28, the blowing direction E of the cooling fan 21 is inclined toward the power supply board surface portion 201, so that the cooling air can be efficiently blown onto the components 205, which are heat generating bodies, mounted on the power supply board surface portion 201. As a result, the cooling performance of the power supply board 20 in the rice cooker 100 can be improved.

[0061] <Variation 1> Next, a first modified example of the first embodiment will be described with reference to Figs. 29 to 32. Fig. 29 is a perspective view showing the configuration of a fin cover provided in a rice cooker according to the first modified example of the first embodiment. Fig. 30 is a perspective view showing a state in which the fin cover is mounted on a power supply board in a rice cooker according to the first modified example of the first embodiment. Figs. 31 and 32 are plan views showing the configuration of a fin cover provided in a rice cooker according to the first modified example of the first embodiment. Fig. 31 shows the fin cover viewed from the upward direction Z1 side in the height direction Z, and Fig. 32 shows the fin cover viewed from the downward direction Z2 side in the height direction Z.

[0062] 29, in Modification 1, a protrusion 338 is provided on the inner surface of fin cover 33A, which is formed in a convex shape from upper end 334 to lower end 335 of fin cover 33A. That is, protrusion 338 is formed over the entire length in height direction Z of fin cover 33A.

[0063] As shown in Figs. 29 to 32, the protrusion 338 is provided on the inner wall of the rear portion 330 of the fin cover 33A. Moreover, as shown in Figs. 31 and 32, the protrusion 338 protrudes from the inner wall of the rear portion 330 in the depth direction Y toward the front direction Y1. The protrusion 338 protrudes from the inner wall of the rear portion 330 toward the space 337 inside the fin cover 33A. When the fin cover 33A is attached to the heat dissipation fins 32, the protrusion 338 is disposed so as to be parallel to the heat dissipation members 32a of the heat dissipation fins 32.

[0064] As shown in Figs. 29 to 32, the convex portion 338 has a plate-like shape and is disposed in the center of the width direction X on the inner wall of the back surface portion 330 of the fin cover 33A. As described above, the heat dissipation fin 32 is attached to the power supply board 20 by the fixture 206 such as a screw. Therefore, as shown in Fig. 31, in the center of the width direction X of the heat dissipation fin 32, the interval W1 at which the heat dissipation member 32a is disposed is larger than the interval W2 in other parts in order to secure a space for disposing the fixture 206. Since the interval W2 is narrow, the cooling air flowing through the gap of the interval W2 passes near the heat dissipation member 32a of the heat dissipation fin 32. Therefore, the heat exchange between the heat dissipation member 32a and the cooling air is efficiently performed. On the other hand, since the interval W1 is wider than the interval W2, a part of the cooling air flowing through the gap of the interval W1 flows away from the heat dissipation member 32a. In that case, the efficiency of the heat exchange between the heat dissipation member 32a and the cooling air decreases. Therefore, in the first modification, the convex portion 338 is disposed between the two heat dissipation members 32a disposed at the interval W1. This allows the cooling air to flow through the narrow gap between the convex portion 338 and the heat dissipation member 32a. As a result, the cooling air passes near the heat dissipation member 32a of the heat dissipation fin 32. Therefore, heat exchange between the heat dissipation member 32a and the cooling air is efficiently performed.

[0065] In this manner, in the first modification, the convex portion 338 is provided in an area where the heat dissipation members 32a of the heat dissipation fin 32 are spaced apart from one another at larger intervals than the other heat dissipation members 32a. This allows the flow path of the cooling air to be formed only in the vicinity of the heat dissipation members 32a. As a result, the cooling air passes in the vicinity of the heat dissipation members 32a of the heat dissipation fin 32, so that heat exchange between the heat dissipation members 32a and the cooling air is efficiently performed, and the cooling performance is further improved.

[0066] The protrusion 338 may be formed over the entire length of the fin cover 33A in the depth direction Y, but this is not limited to the first modification. That is, in the first modification, as shown in Figs. 31 and 32, the protrusion 338 is formed so as to be shorter in the depth direction Y than the entire length of the fin cover 33A in the depth direction Y. As described above, the heat dissipation fin 32 is attached to the power supply board 20 by the mounting fixture 206 such as a screw. Therefore, the protrusion 338 is formed so as to be shorter in the depth direction Y than the entire length of the fin cover 33A in the depth direction Y so as not to come into contact with the mounting fixture 206.

[0067] As shown in FIG. 29, the protruding portion 338 has a V-shaped inclined portion 338a at the lower end. The inclined portion 338a is formed in a V-shape protruding toward the windward side in the direction in which the cooling air flows (i.e., the direction toward the upward direction Z1). That is, the inclined portion 338a has a V-shape, i.e., a triangular shape, when viewed from the front direction Y1 side in the depth direction Y. The cross-sectional shape of the inclined portion 338a cut on a plane parallel to the XZ plane is a triangular shape. The inclined portion 338a has the same rectangular shape as the protruding portion 338 in a plan view. That is, the inclined portion 338a is formed so that the plate thickness of the protruding portion 338 gradually decreases toward the downward direction Z2, and the tip portion (lower end portion) arranged on the windward side is pointed. That is, the inclined portion 338a is thinnest on the windward side and gradually becomes thicker toward the leeward side.

[0068] In this way, the inclined portion 338a is provided to guide the cooling air discharged from the cooling fan 21. The cooling air discharged from the cooling fan 21 flows along the outer wall of the inclined portion 338a and flows into the heat dissipation fins 32. Therefore, the airflow of the cooling air discharged from the cooling fan 21 is naturally guided to the heat dissipation fins 32 without any pressure loss.

[0069] If the inclined portion 338a were not provided, the cooling air discharged from the cooling fan 21 would collide with the lower end of the rectangular shape of the convex portion 338. In that case, the airflow of the cooling air discharged from the cooling fan 21 would experience a pressure loss, causing a decrease in flow speed, and part of the cooling air would flow toward the left and right of the convex portion 338, so that the cooling air would not be efficiently guided to the heat dissipation fins 32.

[0070] In the first modification, since a V-shaped inclined portion 338a is provided at the lower end of the protrusion 338, the cooling air discharged from the cooling fan 21 is guided to the heat dissipation fins 32 without pressure loss. This allows the cooling air to be efficiently applied to the heat dissipation fins 32. As a result, the cooling performance is further improved.

[0071] As described above, in the rice cooker 100 according to the first embodiment, as shown in FIG. 13, the width L1, which is the size in the width direction X of the cooling fan 21, is larger than the width L2 of the heat dissipation fin 32. In this way, by using a cooling fan 21 with a large diameter, the air volume of the cooling fan 21 is increased, and the heat dissipation performance and cooling performance of the power supply board 20 are improved. As a result, even if the heating power of the rice cooker 100 is increased and the amount of heat generated by the power supply board 20 increases, the heat generated by the power supply board 20 can be efficiently dissipated, so that the temperature rise of the power supply board 20 can be suppressed. Therefore, the heating power of the rice cooker 100 can be increased more than before. Therefore, in the rice cooker 100 according to the first embodiment, the amount of heat generated by the induction heating coil 3 can be increased, and the heating power of the rice cooker 100 can be improved. As a result, rice can be cooked at a high temperature, which improves the taste of the cooked rice and enables rice to be cooked at a high speed.

[0072] Furthermore, the rice cooker 100 according to the first embodiment is provided with a fin cover 33 that covers the heat dissipation fins 32. The fin cover 33 has a first opening 40 that takes in cooling air to the heat dissipation fins 32, and a second opening 41 that releases the cooling air into the power supply board 20 after cooling the heat dissipation fins 32. This allows the airflow released from the cooling fan 21 to flow along the heat dissipation fins 32, so that the cooling air can be efficiently applied to the heat dissipation fins 32. As a result, the heat dissipation performance and cooling performance of the power supply board 20 are improved.

[0073] Moreover, the opening area of ​​the second opening 41 is formed to be smaller than the opening area of ​​the first opening 40. Therefore, the cooling air flowing inside the fin cover 33 narrows as it goes downwind, so the air speed gradually increases. In this way, by increasing the air speed, the cooling air can be efficiently applied to the heat dissipation fins 32. In addition, the cooling air flowing outside the fin cover 33 flows along the outer wall of the tapered portion 332 of the fin cover 33. The tapered portions 332 expand in a direction away from each other as they move toward the downward direction Z2 of the height direction Z. In this way, the cooling air flows along the outer wall of the tapered portion 332, so that the cooling air flows so as to expand to the left and right as shown in FIG. 26. As a result, the cooling air is more likely to flow from the gap at the bottom of the power supply board 20 toward the center part of the bottom case 8 of the rice cooker 100. As a result, the heat dissipation performance and cooling performance of the power supply board 20 are further improved. [Explanation of symbols]

[0074] 1 main body, 2 inner case, 3 induction heating coil, 4 temperature sensor, 5 inner pot, 6 hinge portion, 7 lid body, 7a outer lid, 7b inner lid, 8 bottom case, 9 lid heater, 20 power supply board, 21 cooling fan, 21a end portion, 21b end portion, 22 cord reel, 23 power plug, 24 operation display portion, 25 operation board, 30 intake port, 31 exhaust port, 32 heat dissipation fin, 32a heat dissipation member, 32b base portion, 33 fin cover, 33A fin cover, 40 first opening portion, 41 second opening portion, 50 flange portion, 50a horizontal portion, 50b vertical portion, 100 rice cooker, 200 rear member, 201 power supply board surface portion, 202 upper surface portion, 203 side portion, 204 rear portion, 205 parts, 206 Mounting fixture, 330 rear portion, 330a lower end region, 331 side portion, 332 tapered portion, 334 upper end portion, 335 lower end portion, 336 protrusion portion, 337 space, 338 convex portion, 338a inclined portion, B arrow, C1 arrow, C2 arrow, D arrow, E blowing direction, H1 height, L1 width, L2 width, R1 opening area, R2 opening area, X width direction, Y depth direction, Y1 front direction, Y2 rear direction, Z height direction, Z1 upward direction, Z2 downward direction, W1 interval, W2 interval, θ angle.

Claims

1. A main body having a cylindrical shape with an upper end and a lower end open; a bottom case covering an opening at a lower end of the main body and having an intake port and an exhaust port; An inner pot that is detachably accommodated inside the main body; A heating unit disposed in the main body for heating the inner pot; A power supply board that is disposed in the main body and drives the heating unit; A heat dissipation fin disposed on the power supply board; a cooling fan disposed at the intake port of the bottom case and configured to blow cooling air taken in through the intake port toward the heat dissipation fins and the power supply board; A fin cover that covers the heat dissipation fins; Equipped with When the width direction of the main body is defined as a first direction, The heat dissipation fin includes a plurality of heat dissipation members arranged side by side at intervals in the first direction, a width of the cooling fan in the first direction is greater than a width of the heat dissipation fin in the first direction, The fin cover is a first opening through which the cooling air taken in from the air intake by the cooling fan is taken into the heat dissipation fins; a second opening for discharging the cooling air from the heat dissipation fins after the cooling air taken in from the first opening has cooled the heat dissipation fins; A convex portion is provided on an inner surface of the fin cover and is formed in a convex shape from an upper end portion to a lower end portion of the fin cover; having Rice cooker.

2. The opening area of ​​the second opening is smaller than the opening area of ​​the first opening. The rice cooker according to claim 1.

3. The first opening is formed to cover the cooling fan along the width of the cooling fan.

3. The rice cooker according to claim 1 or 2.

4. The second opening is formed along the width of the heat dissipation fin. The rice cooker according to any one of claims 1 to 3.

5. The fin cover has a box shape with at least a portion open, When the height direction of the main body is defined as a second direction, The fin cover is A pair of side portions extending in the second direction and disposed opposite each other; a pair of tapered portions provided at lower ends of the side portions, the tapered portions expanding in directions away from each other as they extend downward in the second direction; having The rice cooker according to any one of claims 1 to 4.

6. The cooling air taken into the heat dissipation fins from the first opening of the fin cover flows along an inner wall of the tapered portion inside the fin cover. The rice cooker according to claim 5.

7. The cooling air discharged from the second opening of the fin cover toward the power supply board flows along the outer wall of the tapered portion outside the fin cover, is guided to the outer wall of the tapered portion, and is exhausted from the exhaust port of the bottom case.

7. The rice cooker according to claim 5 or 6.

8. The protrusion has an inclined portion provided at a lower end of the protrusion, The inclined portion is formed in a V-shape protruding toward the upwind side in the direction in which the cooling air flows, and guides the cooling air taken in from the first opening to the heat dissipation fins. The rice cooker according to any one of claims 1 to 7.

9. the cooling fan is disposed such that a blowing direction of the cooling air is inclined toward a direction in which the cooling air strikes the mounting surface of the power supply board, rather than a direction parallel to the mounting surface on which components of the power supply board are mounted. The rice cooker according to any one of claims 1 to 8.

10. The power supply board has a box shape with at least a portion open, the heat dissipation fin is disposed in a central portion of a mounting surface that forms a part of the box shape of the power supply board, the cooling air that has passed through the inside of the heat dissipation fins is discharged from the heat dissipation fins into the inside of the power supply board, and after cooling the components mounted on the power supply board, is discharged to the outside of the power supply board through an opening in the power supply board. The rice cooker according to any one of claims 1 to 9.

11. When the depth direction of the main body is defined as a third direction, the power supply board and the air intake are disposed on a rear side in the third direction, The exhaust port is disposed on the front side in the third direction. The rice cooker according to any one of claims 1 to 10.

Images