JP2007109667A - Induction heating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To conduct heating operation while watching a heating state by nearly arranging a heating coil and an operation part. <P>SOLUTION: In the induction heating device, a first shield part 49 is installed between a first heating coil 32 and a first operation part 42 and grounded to a metal housing 11 to ground noise generating from the first heating coil 32 to the metal housing 11, and to protect with the first shield part 49, and since the first operation part 42 can be positioned in the vicinity of the first heating coil 32, heating operation is conducted while watching the heating state, and usability is increased. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an operation unit of an induction heating device used in a home or a commercial kitchen.

An operation unit having an input device using a conventional capacitance method does not have a shield part (see, for example, Patent Document 1).
JP-A 62-66524

  However, the operation part of the conventional induction heating device is required to have an operation part that can be easily operated while cooking and can be operated while checking the state of cooking.

  It is an object of the present invention to provide an accurate response without malfunction of a switch of an operation unit disposed in the vicinity of a heating coil during induction heating.

  In order to solve the above-mentioned conventional problems, the induction heating device of the present invention has a shield member disposed between the operation unit and the heating coil when the operation unit located near the heating coil is operated during induction heating such as cooking. The shield member is configured to be grounded.

  As a result, even if the operation unit is arranged in the vicinity of the heating coil so that the operation unit can be operated while checking the state of heating while cooking, etc., the operation unit that responds accurately without malfunction due to noise etc. can get.

  The induction heating device of the present invention does not cause malfunction by providing a shield part provided on the top plate lower surface or the top surface lower part and a connecting member for electrically connecting the metal casing and the shield part. A stable performance can be realized.

  1st invention is equipped with the metal housing | casing, the top plate which covers the upper part of the said metal housing | casing, the heating coil incorporated in the metal housing | casing, and the control circuit, and is provided in the said top plate lower surface or the top surface lower part. And a connecting member that electrically connects the metal casing and the shield part, and has an effect that noise from the top plate can be grounded by the shield part.

  2nd invention is set as the structure which formed the shield part on the lower surface of the top plate by printing, and has the effect | action that a shield part can be formed by printing.

  3rd invention is equipped with the metal housing | casing, the top plate which covers the upper part of the said metal housing | casing, the flame | frame which fixes the said top plate, the heating coil incorporated in the metal housing | casing, and a control circuit, A shield part provided on a lower surface of the top plate, and a connection member for electrically connecting the metal casing and the shield part, wherein the connection member is configured to fix the frame to the metal casing. In addition, since the grounding of the shield portion is also used as a part of the assembly of the main body, it is not necessary to perform the grounding work at the time of assembling and disassembling such as repair, and thus the grounding work is not involved.

  4th invention is provided with the metal button, the top plate which covers the upper part of the metal case, the heating coil built in the metal case, and the control circuit, and the contact button provided on the top surface of the top plate, And an electrode provided on the lower surface of the top plate, a shield portion provided on the outer periphery of the electrode on the lower surface of the top plate, and a connection member for electrically connecting the metal casing and the shield portion. Even if the operation unit is arranged in the vicinity of the heating coil, the induction heating operation can be performed while confirming the state of cooking or the like without malfunction due to noise or the like during induction heating.

  According to a fifth aspect of the invention, an electrode is formed by printing on the lower surface of the top plate, and the operation is detected by a change in electrostatic capacity without drilling the top plate. There is an effect that the operation unit can be easily provided on the top plate by printing or the like without malfunction even if the differential unit is arranged in the vicinity of the heating coil.

  The sixth invention has a configuration in which the shield portion is formed by printing on the bottom surface of the top plate, and has an effect that the shield portion can be processed at the same time as the top plate is printed and can have a simple configuration.

  In a seventh aspect of the present invention, the gap between the shield part and the electrode is formed so as to be a constant distance, and at the same time, the effect of the electrostatic shield is great at a position close to the electrode, and at the same time, between the electrode and the shield part. This has the effect of having the highest dielectric strength without partial concentration of the dielectric strength.

  In an eighth aspect of the present invention, the shield portion is arranged between the electrode and the heating coil, and is positioned between the heating coil and the electrode, which is one of the largest sources of noise. It has the effect of having the greatest shielding effect.

  In the ninth aspect of the invention, the electrical resistance between the one end and the other end of the shield portion is set to 10 kiloohms or less, and the control circuit for controlling the signal of the electrode is generally composed of a semiconductor, so that from the electrode side The internal resistance of the control circuit as seen is generally several kilo ohms to several tens of kilo ohms, and if the ground resistance of the shield portion is 10 kilo ohms or less, electricity can be discharged to the ground and malfunctions and the like are less likely to occur.

  In the tenth aspect of the invention, the top plate is detachable from the metal housing. When the top plate is assembled to the metal housing, the shield portion can be reliably grounded, and the service such as disassembly is provided. Has the effect of improving the properties.

(Embodiment 1)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings of FIGS. In FIG. 1, reference numeral 11 denotes a substantially rectangular parallelepiped metal casing formed by pressing a steel plate having a thickness of 0.5 mm and having an open top. Reference numeral 12 denotes a rectangular top plate made of heat-resistant glass having a thickness of 4 mm that covers the upper opening of the metal casing 11. The top plate 12 is adhered to the metallic frame 13 by sealing the outer periphery thereof with an adhesive material in a watertight manner. The frame 13 has a substantially rectangular shape, and a longitudinal recess 15 is provided on the rear side where the intake / exhaust grill 14 is placed. Reference numeral 16 denotes three mounting holes provided in the recess 15, which are screwed to the fixing holes 18 formed in the rear flange 17 of the metal housing 11 with machine screws 19.

  The frame 13 has an outer wall 20 formed by constricting the outer periphery downward and an inner wall 22 formed by constricting the inner hole 21 side to which the top plate 12 is bonded. Reference numeral 23 denotes a mounting plate fixed to the frame 13 by welding on the outer periphery of the top plate 12 mounting position at two locations on the front portion of the frame 13. When the mounting plate 23 is welded to the frame 13, the mounting surface 24 is positioned slightly about 1 mm below the lower surface of the top plate 12. The mounting plate 23 is provided with two screw holes 25 each. Reference numeral 26 denotes a hook plate which is pressed into a substantially L shape and is fixed to the screw hole 25 of the mounting plate 23 with a mounting screw 27. One of the hook plates 26 is fixed to the frame 13 via the mounting plate 23, and a hooking claw 28 is formed on the other side so that the hook plate 26 is hooked on the locking portion 29 of the metal housing 11. A slit 30 is provided in the center of the hooking claw 28, and a fixing screw 31 provided in the locking portion 29 is set in the slit 30 when hooked on the locking portion 29. The fixing screw 31 is tightened in a state where the hooking claw 28 is hooked on the locking portion 29 and is fixed to the metal casing 11.

  The front portion of the frame 13 is fixed to the metal casing 11 with a fixing screw 31 via the hook plate 26. On the other hand, the rear portion of the frame 13 is fastened with a machine screw 19 with the mounting hole 16 of the frame 13 aligned with the fixing hole 18 of the metal housing 11. The frame 13 to which the top plate 12 is bonded as described above is fixed to the metal casing 11.

  Reference numeral 32 denotes a first heating coil, which is housed while being supported by three support springs 33 on the right side of the metal casing 11. Reference numeral 34 denotes a second heating coil that is housed while being supported by three support springs 33 on the left side of the metal casing 11. Reference numeral 35 denotes an operation unit, and the lower part of the operation unit 35 is pivotally opened when used. Reference numeral 36 denotes a roaster for grilling fish or the like with a sheathed heater. Reference numeral 37 denotes a radiant heater. A control circuit 38 is air-cooled by a cooling fan 39 when used. The cooling fan 39 sucks air from the intake / exhaust grill 14 to cool the control circuit 38, the first heating coil 32, and the second heating coil 34, and then is exhausted from the intake / exhaust grill 14.

  The first heating coil 32 is driven by a current having a frequency of about 20 kHz as in the case of the first heating coil 32 when the object to be heated is a magnetic material, but the frequency is about 60 kHz when the object is a non-magnetic material. Drive with the current of. The reason is that a non-magnetic material cannot be heated sufficiently unless it is placed in a magnetic field having a frequency higher than that of the magnetic material or a large amount of magnetic flux is not passed. The second heating coil 34 is driven by the control circuit 38 with a current having a frequency of about 20 kHz.

  Reference numeral 40 denotes an operation detection circuit housed in the front part of the metal casing. Reference numeral 41 denotes a contact button formed by printing on the front center upper surface of the top plate 12, and controls the driving of the first heating coil 32 and the second heating coil 34 by touching the button with a finger. The contact button 41 includes a first operation unit 42 for operating the first heating coil 32 and a second operation unit 43 for operating the second heating coil 34. 45. A down button 46 is arranged on the left. The first operation unit 42 is located in the vicinity of the first heating coil 32, and the second operation unit 43 is located in the vicinity of the second heating coil 34. Reference numeral 47 denotes an electrode formed by printing on the bottom surface of the top plate 12 below the contact button 41. The electrode 47 is paired with the contact button 41 and is positioned below each contact button 41 to form a capacitor with the top plate 12 interposed therebetween. The electrode 47 located on the lower surface of the top plate 12 of the first operation unit 42 and the second operation unit 43 has a substantially track-shaped outer periphery. That is, the pair of electrodes of the on / off switch 44 has a rectangular shape, and one of the up button 45 and the down button 46 has a straight line and the other has a semicircular shape. Reference numeral 48 denotes a power feeding portion which is paired with the electrode 47 and is formed of phosphor bronze or the like which comes into contact with the electrode 47 when the frame 13 is fixed to the metal housing 11 and has a spring property. One end of the power supply unit 48 is connected to the electrode 47 and the other end is connected to the control circuit 38.

  The electrode 47 is connected to the control circuit 38. When the contact button 41 is touched with a finger or the like, the contact button 41 is grounded via a human body, and the electric capacity between the electrode 47 and the contact button 41 changes. The control circuit 38 detects this change in electric capacity and determines that the contact button 41 has been pressed.

  Reference numeral 49 denotes a first shield part formed by printing a conductive paint on the lower surface of the top plate 12 by printing, and is located between the first heating coil 32 and the first operation part 42. The first shield part 49 is located between the electrode 47 of the first operation part 42 and the first heating coil 32, and is disposed at a position close to the first shield part 49. An insulating space 50 having a high electrical resistance exists between the first shield part 49 and the first operation part 42.

  The first shield part 49 includes a protective part 51 in the vicinity of the first operation part 42 and a substantially linear conductive part 52, and a contact part 53 is provided at the tip of the conductive part 52. The first shield part 49 other than the contact part 53 is coated with an insulating paint 54 so as not to conduct directly. Only the contact portion 53 can conduct electricity. The electrical resistance from the protection part 51 to the contact part 53 is about 2 kilohms. This electric resistance depends on the material of the conductive paint and the shape of the first shield part 49.

  The conductive portion 52 is located in the vicinity of the mounting plate 23. 55 is a conductive tape which is formed of a metal mesh or the like and becomes electrically conductive when bonded, and one end is bonded to the contact portion 53 and the other end is bonded to the mounting plate 23. As a result, the contact portion 53 is electrically connected to the mounting plate 23. A hook plate 26 is fixed to the attachment plate 23 with a machine screw 19. The hook plate 26 is fixed to the metal casing 11 with a fixing screw 31. Therefore, the first shield part 49 is electrically connected to the metal casing 11.

  The attachment plate 23, the hook plate 26, and the conductive tape 55 form a connection member, and the first shield part 49 and the second shield part 56 and the metal casing 11 are electrically connected.

  When the conductive tape 55 is bonded to the mounting plate 23, the conductive tape 55 is bonded so that the conductive tape 55 can be seen from the end of the hook plate 26 when the hook plate 26 is fixed to the screw hole 25 with the mounting screw 27. This is to prevent forgetting to attach the conductive tape 55.

  In order to separate the frame 13 from the metal housing 11 for repair or the like, the fixing screw 31 of the front locking portion 29 is loosened. Next, the rear machine screw 19 is removed. As a result, the hooking claw 28 is detached from the locking portion 29 and the frame 13 is separated from the metal casing 11. At this time, the grounding of the first shield part 49 is also separated when the hook plate 26 and the metal casing 11 are separated.

  Reference numeral 56 denotes a second shield part, which is located between the second heating coil 34 and the electrode 47. The shape and positional relationship are the same as those of the first shield part 49. Reference numeral 57 denotes a light emitting diode that displays the driving status of the first heating coil 32 and the like. A power supply holding unit 58 holds the power supply unit 48 and is made of synthetic resin.

  About the induction heating apparatus comprised as mentioned above, the operation | movement is demonstrated using FIG. The heating by the second heating coil 34 is substantially the same as the heating by the first heating coil 32, and only the operation of the first heating coil 32 will be described. When the pan placed on the top plate 12 is made of a magnetic material, the control circuit 38 drives the first heating coil 32 with a current having a frequency of about 20 kHz. When the pan is made of a nonmagnetic material, the control circuit 38 drives the first heating coil 32 with a current having a frequency of about 60 kHz. Although noise is generated from the first heating coil 32, the first shield part 49 is located between the first operation part 42 and the first heating coil 32, and the metal casing is provided via the contact part 53. 11, the noise electric field from the first heating coil 32 is blocked by the shield portion 49.

  When disassembling for repair or the like, regarding the grounding of the first shield part 49, the grounding is separated when the hook plate 26 is separated from the metal casing 11, and the grounding of the first shield part 49 is completed when the frame 13 is assembled. . Since there is no need for assembly and disassembly, and since there is no forgetting to ground, the grounding can be performed reliably, and the first operation unit 42 and the second operation unit 43 can be reliably operated with little influence of noise. The second shield part 56 has the same shape and function as the first shield part 49, and a description thereof will be omitted.

  As described above, according to the present embodiment, the first shield portion 49 and the second shield portion 56 are provided on the lower surface of the top plate 12 and grounded to the metal casing 11 via the hook plate 26. The malfunction of the first operation unit 42 and the second operation unit 43 with respect to noise can be prevented. Even when disassembled for repair or the like, the grounding wiring of the first shield part 49 and the second shield part 56 is completed by tightening the hook plate 26 at the time of disassembly and assembly. Never forget the grounding work.

(Embodiment 2)
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. In FIG. 6, the top plate 12, the mounting plate 23, the mounting surface 24, the screw hole 25, the hook plate 26, the first shield part 49, the protective part 51, the conductive part 52, the contact part 53, and the conductive tape 55 are shown in the first embodiment. The same name and the same symbol are used.

  The difference from the first embodiment is the electrode 61, which has a shape that maintains a uniform distance from the protection unit 51. Accordingly, the insulating space 62 between the end portion of the electrode 61 and the end portion of the protection portion 51 has a parallel shape.

  About the induction heating apparatus comprised as mentioned above, the operation | movement is demonstrated using FIG. Since the distance from the electrode 61 to the protection part 51 is uniform, the generated electric field is constant, and a uniform electric field can be formed without generating a strong electric field partially.

  As described above, since the distance between the electrode 61 and the protective portion 51 is maintained at a uniform distance, a stable electric field can be formed and a configuration that is strong against noise can be obtained.

  In the first embodiment, the first shield part 49 is provided in the vicinity of the first operation part 42, and the second shield part 56 is provided in the vicinity of the second operation part 43. You may provide in the 2nd heating coil 34 vicinity. Moreover, although the 1st shield part 49 and the 2nd shield part 56 were formed by printing conductive paint, you may arrange | position another component in the lower surface vicinity of the top plate 12. FIG.

  In addition, although the connection member is formed by the mounting plate 23, the hook plate 26, and the conductive tape 55, it is only necessary that the first shield portion 49 and the metal housing 11 are electrically detachably connected. In addition, the electrical connection between the contact portion 53 and the mounting plate 23 is performed with the conductive tape 55, but soldering, welding, or the like may be used. In short, as long as the contact portion 53 and the hook plate 26 are electrically connected. Needless to say, it is good.

  As described above, the induction heating device according to the present invention includes the shield part provided on the top plate lower surface or the top surface lower part, and the connection member that electrically connects the metal housing and the shield part. Since it is possible to stabilize the performance without causing malfunction, it can also be applied to uses such as cooking equipment used in homes and commercial kitchens.

The partial perspective view of the hook plate vicinity of the induction heating apparatus in Embodiment 1 of this invention The exploded perspective view of the induction heating apparatus in Embodiment 1 of this invention The fragmentary sectional view of the hook plate vicinity of the induction heating apparatus in Embodiment 1 of this invention The top view from the downward direction of the top plate of the induction heating apparatus in Embodiment 1 of this invention The top view of the 1st shield part vicinity of the induction heating apparatus in Embodiment 1 of this invention The top view of the 1st shield part vicinity of the induction heating apparatus in Embodiment 2 of this invention

Explanation of symbols

11 Metal housing 12 Top plate 23 Mounting plate (connection member)
26 Hook plate (connection member)
32 First Heating Coil 34 Second Heating Coil 38 Control Circuit 41 Contact Button 47 Electrode 49 First Shield Part 55 Conductive Tape 56 Second Shield Part 61 Electrode

Claims (10)

A metal case, a top plate covering an upper part of the metal case, a heating coil built in the metal case, and a control circuit, a shield part provided on the lower surface of the top plate or the lower part of the top surface, An induction heating apparatus comprising a connection member for electrically connecting the metal casing and the shield part. The induction heating device according to claim 1, wherein the shield portion is formed on the bottom surface of the top plate by printing. A metal case, a top plate that covers the top of the metal case, a frame that fixes the top plate, a heating coil built in the metal case, and a control circuit are provided on the bottom surface of the top plate. An induction heating apparatus comprising: a shield part; and a connection member that electrically connects the metal casing and the shield part, wherein the connection member fixes the frame to the metal casing. A metal case, a top plate covering the top of the metal case, a heating coil built in the metal case, and a control circuit, a contact button provided on the top surface of the top plate, and a bottom surface of the top plate The induction heating apparatus provided with the electrode provided, the shield part provided in the said electrode outer periphery of the said top plate lower surface, and the connection member which electrically connects the said metal housing | casing and the said shield part. The induction heating apparatus according to claim 4, wherein the electrode is formed on the bottom surface of the top plate by printing. The induction heating apparatus according to claim 4 or 5, wherein the shield part is formed on the bottom surface of the top plate by printing. The induction heating apparatus according to any one of claims 4 to 6, wherein a gap between the shield part and the electrode is formed to be a constant distance. The induction heating device according to any one of claims 4 to 7, wherein the shield portion is disposed between the electrode and the heating coil. The induction heating apparatus according to any one of claims 4 to 8, wherein an electrical resistance between one end and the other end of the shield portion is set to 10 kiloohms or less. The induction heating apparatus according to any one of claims 4 to 9, wherein the top plate is detachable from the metal casing.

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