JP2004265871A - Cooling structure of induction heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a cooling performance of a coil by removing a dead water region of cooling air generated around a coil or the like, and to reduce the temperature to a predetermined allowable temperature or less.
SOLUTION: A coil 3 wound in a disk shape, an electronic component 4 for generating high-frequency electricity, a fan 7 for cooling the coil 3 and the like, a coil housing 1a for accommodating the coil 3, an electronic component 4, A housing 1 comprising an electronic component housing 1b for accommodating a fan 7 and a top plate 2 covering the surface of the housing 1, and a magnet placed on the top surface of the top plate 2 by high-frequency electricity flowing through the coil 3. In an induction heating device that heats with an eddy current generated in the body, a flow guide plate 14 that guides cooling air to the coil 3 by partially blocking the flow of cooling air blown by the fan 7 in the coil housing 1a is connected. Then, the cooling air is led to the coil 3 to cool the coil 3.
[Selection] Fig. 6

Description

  The present invention relates to a cooling structure for a coil for an induction heating device such as an electromagnetic cooker.

  The induction heating device supplies high-frequency electricity to a coil, induces eddy currents in a magnetic body near the coil, and heats the coil.

  As an example of a cooling structure of a conventional induction heating device, a cooling structure of an electromagnetic cooker shown in FIGS. 1, 7, 8, and 9 will be described. Here, FIG. 1 is a front view of the present invention and a conventional electromagnetic cooker, and FIG. 7 is a sectional view taken along the line AA of FIG. 8 is an internal structural view of the conventional electromagnetic cooker with the top plate removed, and FIG. 9 is a sectional view taken along line GG of FIG. 8, showing only the upper coil housing part and the lower electronic component housing. The body is omitted.

  At the time of induction heating, the electronic component 4 and the coil 3 that generate high-frequency electricity other than the pot (not shown), which is the portion to be heated, generate heat. In order to prevent the operation from becoming unstable, the electronic component 4 and the coil 3 are cooled by cooling air flowing into the housing 1 (Patent Document 1).

  In the cooling structure, the electronic component 4 is cooled by cooling air sucked from the intake hole 5 by the fan 7 and then guided from the air supply nozzle 9 to the inside 1a of the coil housing, and the coil 3 is cooled and discharged to the atmosphere from the exhaust hole 6 again. I take the. That is, since the allowable temperature of the coil 3 is relatively high, that is, 100 to 140 ° C., the coil 3 is cooled by air that has risen above the atmospheric temperature due to heat radiation of the electronic component 4.

  The structure around the coil 3 includes a temperature sensor 10 for detecting overheating and a number of ferrite members 11 radially attached from the center of the back surface of the coil 3 to the outer periphery for preventing diffusion of electromagnetic energy. The temperature sensor 10 attached to the disc-shaped resin is attached to the top plate 2 at the center of the coil 3 with a spring or the like (Patent Document 2).

  A large number of ferrite members 11 on the back surface of the coil 3 are integrated with a resin 12 and attached to the back surface of the coil 3 as shown in FIG. 9, but the outer periphery 12a and the inner periphery 12b of the resin 12 It protrudes in a ring shape from the disk 12c (Patent Document 3).

JP-A-11-185947

Japanese Patent No. 2964566 Japanese Patent No. 3001844

  In recent years, stainless steel pans have become widespread in terms of hygiene, and an electromagnetic cooker with a high calorific value has been demanded. Accordingly, it has been an issue to find an appropriate cooling method for keeping the electronic component 4 and the coil 3 at a predetermined allowable temperature. There are the following problems regarding cooling of the coil 3 according to the present invention, which hinders a desired allowable temperature.

  As a simple method for improving the cooling performance of the coil 3, there is a case where the amount of cooling air is increased. However, in this method, there is a risk that the water droplets spilled from the pot may exceed the limit speed at which the water droplets scatter and enter the electronic component 4, and it is difficult to significantly increase the cooling air flow.

  Therefore, the first problem is to find a method of making the inlet wind speed of the casing 1 as uniform as possible and increasing the cooling air flow as much as possible within the above-mentioned limit wind speed.

  A second problem is that local stagnation of cooling air due to the structure around the coil 3 occurs on the surface of the coil 3 and the temperature of the coil 3 in the stagnant portion increases. That is, in FIG. 9, there is a local stagnation of flow by the disk-shaped temperature sensor 10 for preventing overheating in the center of the disk-shaped coil 3, and a local flow by a large number of ferrite members 11 attached to the back surface of the coil 3. It is a stagnant flow. Here, the flow style of the cooling air is slightly different between the front and rear surfaces of the coil 3. On the surface of the coil 3, the flow of the cooling air partially stops behind the temperature sensor 10. On the back surface of the coil 3, the cooling air partially stays in a gap formed by the resin 12 protruding in a ring shape and the back surface of the coil 3 excluding the ferrite member 11.

  The stagnation of these flows is called dead water area, and it is difficult to remove even if the cooling air volume is increased.

  The problem to be solved by the present invention is to improve the cooling performance of a coil by removing a dead water region of cooling air generated around the coil in an induction heating device provided with the coil, and to lower the coil to a predetermined allowable temperature or less. That is.

  The present invention has been made to solve the above-described problems. Specifically, a coil wound in a disk shape, an electronic component that generates high-frequency electricity, a fan that cools the coil and the like, and a coil And a top plate that covers the surface of the housing, and a top plate that covers the surface of the case. An induction heating device that heats with an eddy current generated in a placed magnetic body, in which a flow guide plate that guides cooling air to the coil by partially blocking the flow of cooling air sent by a fan in the coil housing is connected. It is.

  According to the present invention, since the flow of the cooling air blown by the fan is partially blocked in the coil housing and the air guide plate for guiding the cooling air to the coil is connected, the dead water area of the cooling air generated around the coil and the like is connected. Can be eliminated, and the cooling performance of the coil is further improved.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1, 2, 3, 4, 5, and 6. FIG.

  FIG. 1 is a front view of the present invention and a conventional electromagnetic cooker. FIG. 2 is a sectional view taken along line AA of FIG. FIG. 3 is an internal structural view of the electromagnetic cooker according to the first embodiment of the present invention from which a top plate is removed. 4 is a sectional view taken along line BB of FIG. 3, and FIG. 5 is a sectional view taken along line CC of FIG. FIG. 6 is a perspective view of the internal structure of the electromagnetic cooker according to the first embodiment of the present invention from which the top plate, the coil, and the like are removed. 4 to 6 show only the upper coil housing, and the lower electronic component housing is omitted. The broken arrows in FIG. 6 indicate the flow of the cooling air.

  Reference numeral 1 denotes a housing, which is composed of a coil housing 1a for storing a coil 3 described later on an upper portion and an electronic component housing 1b for storing an electronic component 4 described later on a lower portion. Reference numeral 2 denotes a top plate, which is provided on the upper surface of the housing 1 and on which a magnetic pot or the like (not shown) serving as a heated portion is placed.

  Reference numeral 3 denotes a coil, which is housed in the coil housing 1a, wound in a disk shape, and generates an eddy current in a magnetic pot or the like (not shown) placed on the upper surface of the top plate 2 by flowing high-frequency electricity. Then, the pot and the like (not shown) are heated. Reference numeral 4 denotes an electronic component, which is housed in the electronic component housing 1b and generates high-frequency electricity.

  Reference numeral 5 denotes an intake hole, which is provided on a part of the side surface of the electronic component casing 1b, and takes in cooling air from outside. Reference numeral 6 denotes an exhaust hole, which is provided on a part of the side surface of the coil housing 1a and discharges air that has cooled the coil 3, the electronic component 4, and the like.

  Reference numeral 7 denotes a fan, which is provided in the vicinity of the intake hole 5 in the electronic component housing 1b, and blows the inside of the external air taken in from the intake hole 5 as cooling air to cool the coil 3, the electronic component 4, and the like. Reference numeral 8 denotes a bottom plate that forms the lower surface of the coil housing 1a.

  Reference numeral 9 denotes an air supply nozzle, which is a hole provided in a part of the bottom plate 8 of the coil housing 1a, and supplies cooling air blown by the fan 7 from the lower electronic component housing 1b to the upper coil housing 1a. . Reference numeral 10 denotes a temperature sensor which is provided in the space in the center of the coil 3 so as to be substantially in contact with the lower surface of the top plate 2, and detects the temperature of the top plate 2 and the like in order to prevent overheating.

  Reference numeral 11 denotes a plurality of ferrite members which are radially arranged on the rear surface of the coil 3 and prevent diffusion of electromagnetic energy of the coil 3.

  Reference numeral 12 denotes a resin, which comprises an outer periphery 12a, an inner periphery 12b, and a disk 12c. A plurality of ferrite members 11 are integrated and attached to the back surface of the coil 3. The outer circumference 12a and the inner circumference 12b protrude from the disk 12c in a ring shape.

  Reference numeral 13 denotes a bypass prevention plate, which is provided between the inner wall of the coil housing 1a and the coil 3 and closes almost all the passage between the inner wall of the coil housing 1a and the coil 3 so that the cooling air blown by the fan 7 is blown. Is prevented from bypassing around the coil 3.

  Reference numeral 14 denotes an air guide plate, which is provided between the ferrite member 11 and the resin 12 on the back surface of the coil 3 and the bottom plate 8 of the coil housing 1a, and is provided between the ferrite member 11 and the resin 12 and the bottom plate 8 of the coil housing 1a. Is partially blocked and the cooling air is guided to the back surface of the coil 3. The baffle plate 14 has a curved structure that intersects the ferrite members 11 radially arranged downstream of the flow of the cooling air in the vicinity of the center of the coil 3. Reference numeral 15 denotes a resistor which is formed by connecting the bypass prevention plate 13 and the air guide plate 14 as shown in FIG.

  Reference numeral 16 denotes a high-pressure space, which is formed on the upstream side of the resistor 15 by blocking the flow of cooling air sent from the fan 7 with the resistor 15 provided in the coil housing 1b. Reference numeral 17 denotes a low-pressure space, which is a low-pressure space formed downstream of the resistor 15.

  The feature of the cooling structure of the present embodiment is that the flow of the cooling air between the ferrite member 11 and the resin 12 and the bottom plate 8 of the coil housing 1a is partially blocked to guide the cooling air to the back surface of the coil 3. That is, the plate 14 is provided.

  The wind guide plate 14 is attached between the ferrite member 11 and the resin 12 on the back surface of the coil 3 and the bottom plate 8 of the coil housing 1a, and is connected to the bypass prevention plate 13 to form the resistor 15, and the coil housing 1a Block the flow of cooling air inside. The air guide plate 14 downstream from the center of the coil 3 is attached in a curved shape that intersects the ferrite members 11 arranged radially.

  That is, all the cooling air that has entered the inside of the coil housing 1a flows into the gap between the top plate 2 and the surface of the coil 3, and the gap between the back surface of the coil 3 and the upper portion of the air guide plate 13.

  Here, in the cooling structure of the present embodiment, the gap between the top plate 2 and the coil 3 is made smaller and the gap between the coil 3 and the bottom plate 8 is made larger than in the conventional structure.

  With the cooling structure described above, a high-pressure space 16 on the upstream side which is pressurized by the fan 7 and a low-pressure space 17 on the downstream side near the exhaust hole 6 are formed.

  The operation of the above cooling structure will be described with reference to FIGS.

  Outside air is drawn into the electronic component casing 1b from the air inlet 5 by the fan 7, and the fan 7 blows to cool the electronic components 4 in the electronic component casing 1b, so that the bottom plate 8 of the coil casing 1a, that is, the electronic component casing. It reaches the intake nozzle 9 provided on a part of the upper surface of 1b. Cooling air flowing into the coil housing 1a from the intake nozzle 9 is collected by the bypass prevention plate 13 and is concentrated and sprayed on the coil 3, so that the wind speed when flowing through the coil 3 increases to promote heat transfer. 3 can be lowered.

  Further, since the space on the upstream side of the baffle plate 14 is pressurized by the fan 7 to form a high-pressure space 16 having a higher pressure than the downstream side, in each space where the ferrite members 11 arranged radially are adjacent, the vicinity of the center of the coil 3 A radial flow from the high pressure space 16 to the low pressure space 17 is formed. The radial flow of the cooling air is temporarily blocked by the baffle plate 14 to form a turbulent air flow accompanied by a contraction and an expansion flow passing through a narrow gap formed by the back surface of the coil 3 and the baffle plate 14. . Thereby, the heat transfer promoting action on the back surface of the coil 3 becomes large.

It is a front view of the present invention and the conventional electromagnetic cooker. It is AA sectional drawing of FIG. 1 which shows the front view of the electromagnetic cooker of this invention. FIG. 2 is an internal structural view of the electromagnetic cooker according to the first embodiment of the present invention from which a top plate is removed. It is BB sectional drawing of FIG. 3 which shows the internal structural drawing which removed the top plate of the electromagnetic cooker of the 1st Example of this invention. FIG. 4 is a CC view of FIG. 3 showing an internal structure diagram of the electromagnetic cooker according to the first embodiment of the present invention from which a top plate is removed. FIG. 2 is a perspective view of the internal structure of the electromagnetic cooker according to the first embodiment of the present invention from which a top plate, a coil, and the like are removed. It is AA sectional drawing of FIG. 1 which shows the front view of the electromagnetic cooking device of a conventional example. It is the internal structure figure which removed the top plate of the conventional electromagnetic cooker. It is GG sectional drawing of FIG. 8 which shows the internal structure figure which removed the top plate of the conventional electromagnetic cooker.

Explanation of reference numerals

Reference Signs List 1 housing 1a coil housing 1b electronic component housing 1c grill housing 2 top plate 3 coil 4 electronic component 7 fan 8 bottom plate 11 ferrite member 13 bypass prevention plate 14 wind guide plate

Claims (1)

A coil (3) wound in a disk shape, an electronic component (4) for generating high-frequency electricity, a fan (7) for cooling the coil (3) and the like, and a coil housing for housing the coil (3) A housing (1) composed of (1a), an electronic component housing (1b) for housing an electronic component (4) and a fan (7), and a top plate (2) covering the surface of the housing (1). In an induction heating device for heating by a eddy current generated in a magnetic material placed on the upper surface of a top plate (2) by high-frequency electricity flowing through a coil (3), a fan (7) is provided in a coil housing (1a). A cooling structure for an induction heating device, characterized in that a flow guide plate (14) for guiding a cooling air to a coil (3) is connected by partially blocking a flow of the cooling air sent by the cooling device.

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