JP2004171930A - Induction heating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an induction heating device allowing a heating operation while watching a heating state by disposing a heating coil in the vicinity of an operation part. <P>SOLUTION: A first shielding part 49 is formed between the first heating coil 32 and the first operation part 42, and grounded to a metal casing 11, so that noise generated from the heating coil 32 is grounded to the metal casing 11, the shielding part 49 can be protected, and the operation part 42 can be positioned in the vicinity of the heating coil 32. Thereby, this easy-to-use induction heating device operable while seeing the heating state can be provided. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an operation unit of an induction heating device used in a home or commercial kitchen.
[0002]
[Prior art]
A conventional operation unit having an input device using a capacitance method does not have a shield unit (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-62-66524
[Problems to be solved by the invention]
It is required that the operation unit of the induction heating device be provided with an operation unit that can be easily operated while cooking and the like and that can be operated while checking the state of the cooking and the like. SUMMARY OF THE INVENTION It is an object of the present invention to accurately respond to a switch of an operation unit disposed near a heating coil without malfunction during induction heating.
[0005]
[Means for Solving the Problems]
In order to solve this problem, the present invention arranges a shield member between the operation unit and the heating coil and grounds the shield member when the operation unit located near the heating coil is operated during induction heating such as cooking. It is configured as follows.
[0006]
Thus, even if the operation unit is arranged near the heating coil so that the operation unit can be operated while checking the state of heating while cooking or the like, the operation unit that responds accurately without malfunction due to noise or the like is provided. can get.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
The invention according to claim 1 of the present invention includes a metal housing, a top plate that covers an upper portion of the metal housing, a heating coil built in the metal housing, and a control circuit, and the lower surface of the top plate Alternatively, the shield portion provided at the lower portion of the top surface, and a connection member for electrically connecting the metal housing and the shield portion are provided, and noise from the top plate can be grounded by the shield portion. It has the action of:
[0008]
The invention according to claim 2 has a configuration in which the shield portion is formed on the lower surface of the top plate by printing, and has an effect that the shield portion can be formed by printing.
[0009]
The invention according to claim 3 includes a metal housing, a top plate that covers an upper portion of the metal housing, a frame that fixes the top plate, a heating coil built in the metal housing, and a control circuit. A shield portion provided on the lower surface of the top plate, and a connection member for electrically connecting the metal housing and the shield portion, wherein the connection member fixes the frame to the metal housing; Since the grounding of the shield part also serves as a part of the assembly of the main body, there is no need to perform the grounding work at the time of assembling and at the time of disassembly such as repair, so that there is an effect that the grounding work can not be performed. .
[0010]
The invention according to claim 4 of the present invention includes a metal housing, a top plate that covers an upper portion of the metal housing, a heating coil built in the metal housing, and a control circuit, wherein the top surface of the top plate is provided. A contact button provided on the top plate, 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 housing and the shield portion. Even if the operation unit is arranged near the heating coil, it is possible to operate the induction heating while checking the state of cooking etc. without malfunction due to noise etc. during the induction heating. Has an action.
[0011]
The invention according to claim 5 has a configuration in which the electrodes are formed on the lower surface of the top plate by printing, and a configuration in which the operation is detected by a change in capacitance without performing processing such as drilling the top plate. This has the effect that the top panel can easily be provided with an operation section by printing or the like without malfunction even if the plug section is disposed near the heating coil.
[0012]
The invention according to claim 6 has a configuration in which the shield portion is formed by printing on the lower surface of the top plate, and has an effect that the shield portion can be simultaneously processed at the time of printing on the top plate and can have a simple configuration.
[0013]
According to a seventh aspect of the present invention, the gap between the shield portion and the electrode is formed to have a fixed distance, and the effect of the electrostatic shield is large at a position close to the electrode, and at the same time, the electrode and the shield portion are formed. This has the effect that the dielectric strength between them is the highest without partial concentration.
[0014]
The invention according to claim 8 has a configuration in which the shield portion is disposed between the electrode and the heating coil, and is located between the heating coil and the electrode, which is one of the largest sources of noise. This has the effect of having the greatest shielding effect.
[0015]
According to a ninth aspect of the present invention, the electric resistance between one end and the other end of the shield portion is set to 10 kΩ or less, and the control circuit for controlling the signal of the electrode is generally made of a semiconductor. The internal resistance of the control circuit viewed from the electrode side is generally several kilohms to several tens of kilohms. If the grounding resistance of the shield part is set to 10 kilohms or less, electricity can be discharged to the ground, and the malfunction or the like hardly occurs.
[0016]
According to a tenth aspect of the present invention, the top plate is configured to be detachable from the metal housing, and when the top plate is assembled to the metal housing, the shield portion can be reliably grounded and disassembled. And the like.
[0017]
【Example】
(Example 1)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. In FIG. 1, reference numeral 11 denotes a substantially rectangular parallelepiped metal housing 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 and covering the upper opening of the metal housing 11. The top plate 12 is bonded to the metal frame 13 by sealing the outer periphery of the top plate 12 with an adhesive in a watertight manner. The frame 13 has a substantially rectangular shape and has a longitudinally long concave portion 15 on the rear side on which the intake and exhaust grille 14 is mounted. Reference numeral 16 denotes three mounting holes provided in the concave portion 15, which are screwed into fixing holes 18 formed in the rear flange 17 of the metal housing 11 with small screws 19.
[0018]
The frame 13 has an outer wall 20 formed by squeezing the outer periphery downward and inward, and an inner wall 22 formed by squeezing the inner hole 21 side to which the top plate 12 is bonded. Reference numeral 23 denotes an attachment plate fixed to the frame 13 by welding at two positions in the front part of the frame 13 to the outer periphery of the attachment position of the top plate 12. When the mounting plate 23 is welded to the frame 13, its mounting surface 24 is located about 1 mm below the lower surface of the top plate 12. The mounting plate 23 has two screw holes 25 at two locations. Reference numeral 26 denotes a hook plate which is fixed in the screw hole 25 of the mounting plate 23 with the mounting screw 27 and is pressed into a substantially L-shape. One of the hook plates 26 is fixed to the frame 13 via the mounting plate 23, and the other is formed with a hooking claw 28, so that the hook plate 26 is hooked on the locking portion 29 of the metal housing 11. A slit 30 is provided at the center of the hooking claw 28, and a fixing screw 31 provided on the locking portion 29 is set in the slit 30 when the hook 30 is 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 housing 11.
[0019]
The front portion of the frame 13 is fixed to the metal housing 11 via a hook plate 26 with fixing screws 31. On the other hand, the rear part of the frame 13 is fastened with small screws 19 so that the mounting holes 16 of the frame 13 are aligned with the fixing holes 18 of the metal housing 11. The frame 13 to which the top plate 12 is adhered as described above is fixed to the metal housing 11.
[0020]
Reference numeral 32 denotes a first heating coil, which is housed on the right side of the metal housing 11 while being supported by three support springs 33. Reference numeral 34 denotes a second heating coil, which is housed on the left side of the metal housing 11 while being supported by three support springs 33. Reference numeral 35 denotes an operation unit, and the lower part of the operation unit 35 is pivotally supported and opened at the time of use. 36 is a roaster for baking fish and the like with a sheath heater. Reference numeral 37 denotes a radiant heater. A control circuit 38 is air-cooled by a cooling fan 39 at the time of use. The cooling fan 39 draws 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 exhausts the air from the intake / exhaust grill 14.
[0021]
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 substance, but has a frequency of about 60 kHz when the object is a non-magnetic substance. Drive with current of The reason is that the non-magnetic material cannot be heated sufficiently unless it is placed in a magnetic field having a higher frequency than the magnetic material or does not pass a large amount of magnetic flux. The second heating coil 34 is driven by the control circuit 38 with a current having a frequency of about 20 kHz.
[0022]
Reference numeral 40 denotes an operation detection circuit housed in the front of the metal housing. 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 it 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 near the first heating coil 32, and the second operation unit 43 is located near the second heating coil 34. Reference numeral 47 denotes an electrode which is located below the contact button 41 on the lower surface of the top plate 12 and formed by printing. The electrodes 47 are paired with the contact buttons 41 and are located below the respective contact buttons 41 to form a capacitor with the top plate 12 interposed therebetween. The electrodes 47 located on the lower surface of the top plate 12 of the first operation unit 42 and the second operation unit 43 have 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 supply unit which is paired with the electrode 47 and is made 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. The power supply unit 48 has one end connected to the electrode 47 and the other end connected to the control circuit 38.
[0023]
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 capacitance 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.
[0024]
Reference numeral 49 denotes a first shield portion formed by printing a conductive paint on the lower surface of the top plate 12 by baking printing, and is located between the first heating coil 32 and the first operation unit 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 arranged 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.
[0025]
The first shield part 49 includes a protection part 51 near 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 be conductive. The electric resistance from the protection part 51 to the contact part 53 is about 2 kΩ. This electric resistance depends on the material of the conductive paint and the shape of the first shield part 49.
[0026]
The conductive part 52 is located near the mounting plate 23. Reference numeral 55 denotes a conductive tape formed of a metal mesh or the like and having electrical conductivity when bonded, one end of which is bonded to the contact portion 53, and the other end of which is bonded to the mounting plate 23. Thus, the contact portion 53 is electrically connected to the mounting plate 23. A hook plate 26 is fixed to the mounting plate 23 with small screws 19. The hook plate 26 is fixed to the metal housing 11 with fixing screws 31. Therefore, the first shield part 49 is electrically connected to the metal housing 11.
[0027]
A connection member is formed by the mounting plate 23, the hook plate 26, and the conductive tape 55, and the first shield part 49 and the second shield part 56 are electrically connected to the metal housing 11.
[0028]
When the conductive tape 55 is bonded to the mounting plate 23, when the hook plate 26 is fixed to the screw hole 25 with the mounting screw 27, the conductive tape 55 is bonded so that the end of the hook plate 26 can be seen. This is to prevent forgetting to attach the conductive tape 55.
[0029]
In order to separate the frame 13 from the metal casing 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 disengaged from the locking portion 29, and the frame 13 is separated from the metal housing 11. At this time, the grounding of the first shield part 49 is also separated by separating the hook plate 26 and the metal housing 11.
[0030]
Reference numeral 56 denotes a second shield portion, which is located between the second heating coil 34 and the electrode 47. The shape and the positional relationship are the same as those of the first shield part 49. Reference numeral 57 denotes a light emitting diode for displaying a driving state of the first heating coil 32 and the like. Reference numeral 58 denotes a power supply holding unit for holding the power supply unit 48, which is made of synthetic resin.
[0031]
The operation of the induction heating device configured as described above will be described with reference to FIG. The heating by the second heating coil 34 is almost 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. If the pot is made of a non-magnetic 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 connected via the contact part 53. Since it is grounded to 11, the noise electric field from the first heating coil 32 is blocked by the shield 49.
[0032]
When disassembling for repair or the like, the grounding of the first shield part 49 is separated when the hook plate 26 is separated from the metal housing 11, and the grounding of the first shield part 49 is completed when the frame 13 is assembled. . The labor of assembling and disassembling is not required, and since there is no forgetting to ground, reliable grounding is possible, and the operation of the first operating unit 42 and the second operating unit 43 can be reliably performed with less influence of noise. The second shield part 56 also has the same shape and function as the first shield part 49, and the description is omitted.
[0033]
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 housing 11 via the hook plate 26, It is possible to prevent the first operation section 42 and the second operation section 43 from malfunctioning due to noise. Even if disassembled for repair or the like, the ground 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 assembling, so that there is no need for assembling or disassembling. Never forget to ground.
[0034]
(Example 2)
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. 6, the top plate 12, the mounting plate 23, the mounting surface 24, the screw holes 25, the hook plate 26, the first shield part 49, the protection part 51, the conductive part 52, the contact part 53, and the conductive tape 55 are the same as those in the first embodiment. Same shape, same name and same sign are used.
[0035]
The difference from the first embodiment is the electrode 61, which has a shape that maintains a uniform distance from the protection unit 51. Therefore, the insulating space 62 between the end of the electrode 61 and the end of the protection part 51 has a parallel shape.
[0036]
The operation of the induction heating device configured as described above will be described with reference to FIG. Since the distance from the electrode 61 to the protective portion 51 is uniform, the generated electric field is constant, and a uniform electric field can be formed without generating a strong electric field in part.
[0037]
As described above, since the distance between the electrode 61 and the protection unit 51 is maintained at a uniform distance, a stable electric field can be formed, and a configuration resistant to noise can be obtained.
[0038]
In the first embodiment, the first shield part 49 is provided near the first operation part 42 and the second shield part 56 is provided near the second operation part 43. It may be provided near the second heating coil 34. Although the first shield part 49 and the second shield part 56 are formed by printing a conductive paint, another part may be arranged near the lower surface of the top plate 12.
[0039]
Further, the connection member is formed by the mounting plate 23, the hook plate 26, and the conductive tape 55, but it is sufficient that the first shield part 49 and the metal housing 11 are electrically detachably connected. In addition, although the electrical connection between the contact portion 53 and the mounting plate 23 is made by the conductive tape 55, soldering, welding, or the like may be used. In other words, as long as the contact portion 53 and the hook plate 26 are electrically connected. Needless to say, it's good.
[0040]
【The invention's effect】
As described above, according to the present invention, by providing the shield portion provided on the lower surface of the top plate or the lower portion of the top surface, and the connection member for electrically connecting the metal housing and the shield portion, malfunction of the device is provided. It is possible to realize an induction heating device with stable performance that does not occur.
[Brief description of the drawings]
FIG. 1 is a partial perspective view of the vicinity of a hook plate of an induction heating device according to a first embodiment of the present invention. FIG. 2 is an exploded perspective view of the induction heating device according to the first embodiment of the present invention. FIG. 4 is a partial cross-sectional view showing the vicinity of a hook plate of the induction heating device in FIG. 4 FIG. 4 is a plan view of the induction heating device in Example 1 of the present invention from below the top plate; FIG. FIG. 6 is a plan view of the vicinity of the first shield part of the induction heating apparatus according to the second embodiment of the present invention.
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 housing, a top plate that covers the top of the metal housing, a heating coil built in the metal housing, and a control circuit, and a shield unit provided on the lower surface of the top plate or the lower portion of the top surface, An induction heating device comprising: a connection member that electrically connects the metal housing and the shield portion. 2. The induction heating device according to claim 1, wherein the shield part is formed by printing on a lower surface of the top plate. A metal housing, a top plate that covers an upper portion of the metal housing, a frame that fixes the top plate, a heating coil built in the metal housing, and a control circuit are provided on the lower surface of the top plate. An induction heating device comprising: a shield portion; and a connection member for electrically connecting the metal housing and the shield portion, wherein the connection member fixes the frame to the metal housing. A metal housing, a top plate that covers the top of the metal housing, a heating coil built in the metal housing, and a control circuit, a contact button provided on the top surface of the top plate, and a contact button provided on the bottom surface of the top plate An induction heating device comprising: an electrode provided; a shield provided on an outer periphery of the electrode on the lower surface of the top plate; and a connection member for electrically connecting the metal housing and the shield. The induction heating device according to claim 4, wherein the electrodes are formed on the lower surface of the top plate by printing. The induction heating device according to claim 4 or 5, wherein the shield portion is formed on the lower surface of the top plate by printing. The induction heating device according to any one of claims 4 to 6, wherein a gap between the shield part and the electrode is formed to have a fixed distance. The induction heating device according to claim 4, wherein the shield is disposed between the electrode and the heating coil. The induction heating device according to any one of claims 4 to 8, wherein an electric resistance between one end and the other end of the shield part is set to 10 kohm or less. The induction heating device according to any one of claims 4 to 9, wherein the top plate is detachable from the metal housing.

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