JP2001029222A - Rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive, compact and quiet rice cooker for domestic purpose. SOLUTION: A space is provided between an inverter circuit board 16 and an induction heating coil 15, in which a heat sink 18 is disposed and a cooling fan 19 is disposed at the lower side almost in horizontal. As a result, the loss of wind fed by the cooling fan 19 is minimized and the heat sink 18 is made small with the increase of cooling efficiency, making it possible to obtain a compact and noise-suppressed rice cooker body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a rice cooker mainly used at home.

[0002]

2. Description of the Related Art In an electromagnetic induction heating type rice cooker using an induction heating coil, which has been widely used in recent years, various means for cooling heat generated by an induction heating coil and components on an inverter circuit board for controlling energization of the induction heating coil are used. Various methods have been devised, for example, in the following form.

The configuration of a conventional rice cooker will be described below with reference to the drawings.

As shown in FIG. 5, an induction heating coil 53 for heating a pot 52 by an induced electromotive force is provided at a rear portion of a main body 51.
An inverter circuit board 54 for controlling the conduction of the induction heating coil 53 is disposed outside the inverter circuit board 54. A switching element 55 is provided below the inverter circuit board 54.
And a heat sink 56 for thermally diffusing and cooling the heat. Further, a cooling fan 57 is arranged below the heat sink 56.

[0005] A cooling method in this configuration will be described. Most of the outside air drawn from the cooling fan 57 first hits the heat sink 56, and cools the switching element 55 via the heat sink 56. The heat sink 56 has a hole, and some outside air flows into the inverter circuit board 54 without hitting the heat sink to cool other heat generating components. In addition, part of the outside air is dispersed on the side surface of the heat sink and circulates around the induction heating coil 53 to prevent the induction heating coil 53 from generating excessive heat.

[0006]

However, in the rice cooker described above, most of the inhaled outside air is supplied to the heat sink 56.
As a result, a large loss occurs in the flow of the wind, thereby deteriorating the cooling efficiency and generating noise due to the collision with the wind.

Further, holes are formed in the heat sink 56 to cool many components of the inverter circuit board 54, and since air flows over the board, heat conduction in the heat sink 56 is deteriorated. Therefore, the entire heat sink 56 is large.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and minimizes the loss of the flow of the outside air sucked by the cooling fan to effectively reduce the heat sink, the components on the inverter circuit board, and the surface of the induction heating coil. It is a first object of the present invention to reduce the noise level even further.

A second object is to fix the cooling fan to both the protection frame and the inverter circuit board, so that the inverter circuit board is detached or deformed even when subjected to impact, vibration, or the like caused by dropping the main body. The purpose is to prevent cracking.

A third object is to reduce the surface area of the inverter circuit board by reducing the surface area of the inverter circuit board by providing the wiring connection section on the outer periphery of the cooling fan, thereby reducing the size of the rice cooker body. is there.

A fourth object of the present invention is to reduce the number of assembling steps by providing a wiring connection means between an inverter circuit board and an induction heating coil or the like by using an outer portion of a cooling fan.

[0012]

In order to achieve the first object, the present invention provides a main body, a pot removably stored in the main body, a protective frame surrounding the pot, and a protective frame. An induction heating coil provided outside the frame and causing the pan to generate heat by electromagnetic induction, an inverter circuit board for controlling the conduction of the induction heating coil, and a heat sink for cooling the switching elements of the inverter circuit in a thermally diffusive manner; A cooling fan and an openable / closable lid for covering an upper surface opening of the main body are provided, and the heat sink is disposed in a space provided between the inverter circuit board and the induction heating coil, and is provided below the space. A cooling fan is provided.

In order to achieve the second object, according to the present invention, the cooling fins of the heat sink and the direction of the wind discharged by the cooling fan are arranged in parallel with each other.

In order to achieve the third object, according to the present invention, the cooling fan is fixedly disposed on both the protection frame and the outer peripheral portion of the inverter circuit board.

According to a fourth aspect of the present invention, there is provided a cooling fan provided with an induction heating coil or a power supply, and a wiring connection means for connecting the power supply to an inverter circuit board.

According to a fifth aspect of the present invention, a circuit board is provided on a side surface of a cooling fan, and a connection terminal for directly connecting an inverter circuit board to an induction heating coil or a power supply is provided. .

In order to achieve the sixth object, according to the present invention, the wiring connection part is formed integrally with the outer part of the cooling fan.

[0018]

According to the first and second aspects of the present invention, a space is provided between the inverter circuit board and the induction heating coil.
A heat sink is arranged in that space, the cooling fins of the heat sink are arranged vertically, and the wind of the cooling fan is passed in a direction parallel to the cooling fins. Flow, then hit each part to cool down, so that the size of the heat sink is downsized, the cooling fan is downsized by increasing the cooling efficiency, and the cooling fan is downsized or the rotation speed is reduced, and the noise due to the wind noise of the cooling fan is reduced. Can be achieved.

According to the third aspect of the present invention, the inverter circuit board can be firmly fixed by fixing the inverter circuit board from both sides of the upper surface of the main body and the cooling fan on the bottom side.

According to the fourth aspect of the present invention, since the wiring connection between the induction heating coil or the power supply and the inverter circuit board is provided on the side of the cooling fan, the wiring connection on the inverter circuit board has a lead wire. Since it is only necessary to pull out the inverter circuit board directly, the size of the inverter circuit board is reduced, and the size of the rice cooker body can be reduced.

According to the fifth aspect of the present invention, since the connection means between the inverter circuit board and the induction heating coil or the power supply is made by the connection means provided on the outer portion of the cooling fan, wiring processing at the time of assembly work is unnecessary. Thus, the manufacturing cost can be reduced.

According to the sixth aspect of the present invention, since the wiring connection portion and the connection terminal are integrally formed with the outer portion of the cooling fan, the number of components is reduced, and the manufacturing cost can be reduced.

[0023]

(Embodiment 1) An embodiment of the present invention will be described with reference to FIGS.

In FIG. 1, the main body 11 has an open upper surface, and a pot 12 is detachably housed inside the main body 11. An openable and closable lid 13 is supported above the pan 12. The outer periphery of the side and bottom of the pot 12 is covered with a protective frame 14, and an induction heating coil 15 is attached to the outer periphery thereof. An induction electromotive force is applied to the pot 12 by passing a high-frequency current through the induction heating coil 15. Raise and heat, pan 12
The food inside can be heated.

A high-frequency current is supplied to the induction heating coil 15 by an inverter circuit board 16 installed vertically on the front surface of the main body 11.
Has many heat-generating components including the switching element 17. It is the heat sink 18 that cools the switching element 17 in a heat diffusion manner, and the inverter circuit board 1
6 fixed on. A certain space is provided between the inverter circuit board 16 and the induction heating coil 15, and a heat sink 18 is provided in this space.
The lower side of the heat sink 18, that is, the inverter circuit board 1
A cooling fan 19 is installed in a substantially horizontal direction below a space provided between the induction heating coil 6 and the induction heating coil 15,
The outside air is taken into the main body.

The arrangement of the heat sink 18 and the cooling fan 19 is as shown in FIG. FIG. 2 shows the positional relationship between the inverter circuit board, the heat sink, and the cooling fan when viewed from the rear of the main body toward the front. That is, from FIG.
Heat sink 2 arranged on inverter circuit board 21
2 are provided with cooling fins 23 and are arranged substantially vertically. A cooling fan 24 is disposed substantially horizontally below the cooling fan 24.

Here, the component cooling means in this configuration will be described. 1, most of the outside air sucked from the cooling fan 19 passes through the cooling fins arranged on the heat sink 18 to cool the heat sink 18 and flows as it is onto the inverter circuit board 16 so as to flow on the other inverter circuit boards 16. Cool the heat-generating components. At this stage, the cooling air has already absorbed the heat of each heat-generating component and has become hot air. However, while passing through the upper side surface of the pan 12 as it is, the upper part of the pan 12 is appropriately heated to form a hot air. Exhaust from exhaust port.

A part of the remaining outside air sucked from the cooling fan 19 flows toward the induction heating coil 15, separates in the left-right direction, flows to the rear of the main body 11 along the induction heating coil 15, and is discharged from the exhaust hole. Is done. During this time, the heat generated in the induction heating coil 15 is cooled.

(Embodiment 2) Next, a second embodiment will be described with reference to FIG. In FIG. 1, the cooling fan 19 is fixed to the main body 11 at the upper part of the main body 11. However, there is a heavy component such as the heat sink 18 at the lower part of the inverter circuit board 16, and the main body 11 can be tilted, If the inverter circuit board 16 is accidentally dropped on the floor or vibrated during transportation, strong stress is applied to the inverter circuit board 16 and the inverter circuit board 16 may come off, crack, deform, or the like. Therefore, as shown in FIG. 1, the cooling fan 19 is provided with the protection frame 14 on one side and the inverter circuit board 16 on the other side.
If you fix it to the outer part and keep it away from the lower part of the main body 11,
The inverter circuit board 16 is also fixed by the cooling fan 19, and is separated from the lower part of the outer periphery of the main body 11, so that even if the main body 11 falls to the floor, it is not necessary to receive a direct impact from the bottom surface of the main body 11. .

(Embodiment 3) Next, a third embodiment will be described with reference to FIG. In FIG. 3, wiring connection means 32 is provided on the outer periphery of the cooling fan 31. The wiring connection means 32 is a metal fitting, and is fixed to the outer part of the cooling fan 31 with screws. There is a screw hole on the side of the fixed screw, a tapping process is performed, and the screw can be fixed.

Incidentally, a coil lead wire 34 drawn out from the induction heating coil 33 and an inverter circuit board 35
The board lead wire 36 drawn out has a glass terminal crimped at each end, and these two glass terminals are bundled on the screw hole provided in the terminal connection fitting 32 described above, and are screwed. Tighten together. At this time, the board leads 36
Need only be passed through a hole formed in the inverter circuit board 34 and soldered.
The terminal components required for connection to the inverter circuit are unnecessary, and the inverter circuit board 34 is correspondingly reduced in size.

In this embodiment, each lead wire terminal is screwed to the terminal fitting 32. However, the same effect can be naturally obtained by using other connecting means such as a Faston terminal. In addition, the terminal fitting 32 can be integrally molded and fixed to the side surface of the cooling fan 31.

(Embodiment 4) Next, a fourth embodiment will be described with reference to FIG. In FIG. 4, cooling fan connection terminals 43 a and 43 b are provided on the side surfaces of the inverter circuit board 41 and the induction heating coil 42, respectively. And an induction coil connection terminal 45b. The inverter circuit board connection terminal 45a and the induction coil connection terminal 45b are
The four side surfaces are connected by a substantially circuit board 46. Here, when the cooling fan is inserted with the respective connection terminals aligned with each other, the inverter circuit board 41 and the induction heating coil 42 are electrically connected, so that it is not necessary to perform a wiring process using a lead wire or the like.

In this embodiment, the induction heating coil 42
Has been described as means for connecting to the inverter circuit board, but it can be used for various combinations of electrical connections such as connection to a power supply (cord reel) and connection to an external heater wire.

[0035]

As described above, according to the first aspect of the present invention, the heat sink is disposed in the space provided between the inverter circuit board and the induction coil, and the cooling fan is disposed below the space. As a result, the heat loss, the components on the inverter circuit board, and the surface of the induction coil are effectively cooled, minimizing the heat sink and cooling fan. In addition, the size of the rice cooker can be reduced.

According to the second aspect of the present invention, since the cooling fins of the heat sink and the direction of the wind discharged from the cooling fan are made parallel, the loss due to the collision of the wind is reduced, and the noise level is reduced. Can be performed.

According to the third aspect of the present invention, since the cooling fan is fixed to both the protection frame and the inverter circuit board, the inverter circuit board is entirely formed by the cooling fan at the top and bottom of the main body. By fixing, the strength against shock and vibration can be increased.

According to the fourth aspect of the present invention, since the wiring connection between the heating coil or the power supply and the inverter circuit board is provided on the outer part of the cooling fan, the wiring connection component on the inverter circuit board is provided. And the rice cooker body can be made smaller by reducing the surface area of the inverter circuit board.

According to the fifth aspect of the present invention, since a substantially circuit board is provided on the outer part of the cooling fan and the inverter circuit board is connected to the heating coil or the power supply, wiring processing during assembly work is not required. Thus, the manufacturing cost can be reduced.

Further, according to the sixth aspect of the present invention, since the connection terminals are formed integrally with the outer periphery of the cooling fan, the number of parts is reduced, and the number of assembling steps is reduced, so that the manufacturing cost can be reduced. I have.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a rice cooker showing one embodiment of the present invention.

FIG. 2 is a diagram showing a positional relationship between a heat sink and a cooling fan of the rice cooker.

FIG. 3 is a diagram showing wiring connections around a cooling fan of the rice cooker.

FIG. 4 is a diagram showing a wiring connection before a cooling fan of the rice cooker is incorporated.

FIG. 5 is a partial sectional view of a rice cooker showing a conventional embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Main body 12 Pot 13 Lid 14 Protection frame 15, 33, 42 Induction heating coil 16, 35, 41 Inverter circuit board 17 Switching element 18, 22 Heat sink 19, 24, 31, 44 Cooling fan 23 Cooling fin

Claims (6)

[Claims] 1. A pot removably stored in the main body, a protection frame surrounding the pot, an induction heating coil provided outside the protection frame, and causing the pot to generate heat by electromagnetic induction. An inverter circuit board for controlling the energization of the heating coil, a heat sink for cooling the switching elements of the inverter circuit in a thermally diffusive manner, a cooling fan, and an openable / closable lid for covering an upper opening of the main body; A rice cooker in which a heat sink is disposed in a space provided between the inverter circuit board and the induction heating coil, and the cooling fan is disposed below the space. 2. The rice cooker according to claim 1, wherein the cooling fins of the heat sink and the direction of the wind discharged by the cooling fan are arranged in parallel with each other. 3. The rice cooker according to claim 1, wherein the cooling fan is fixedly arranged on both the protection frame and the outer periphery of the inverter circuit board. 4. The rice cooker according to claim 1, wherein a wiring connection means for connecting an induction heating coil or a power supply to the inverter circuit board is provided on an outer portion of the cooling fan. 5. The rice cooker according to claim 1, wherein a substantially circuit board is provided on a side surface of the cooling fan, and a connection terminal for directly connecting the inverter circuit board to an induction heating coil or a power supply is provided. 6. The rice cooker according to claim 4, wherein the wiring connection part is formed integrally with the outer part of the cooling fan.