JPH04309720A - High frequency heating device - Google Patents

Abstract

PURPOSE:To reduce the number of assemblying steps of a high frequency heating device having an inverter power supply installed therein and miniaturize the device and an improve the reliability. CONSTITUTION:A plurality of component elements such as an inverter power supply 1, a fan 2 and a motor 10 of a high frequency heating deice are disposed on the same printed circuit board 11. They are stored in one case 7 to enable them to be one component element and then a simple assemblying operation can be realized. In addition, a plurality of component elements are disposed on the same printed circuit board 11 to enable some lead lines to be eliminated and thus non-required radiation of electromagnetic wave from the lead lines can be eliminated. In addition, the case 7 is made of electrical conductive material to cause a non-required radiation of the electromagnetic wave to be shielded and its reliability in operation can be improved.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a high-frequency heating device that uses microwaves to heat foods and dielectric materials such as catalysts.More specifically, the present invention relates to a high-frequency heating device that uses microwaves to heat foods and dielectric materials such as catalysts. This invention relates to a high-frequency heating device using an inverter power source.

0002

2. Description of the Related Art The structure of a conventional high frequency heating device will be explained using the circuit diagram shown in FIG. In the same figure, commercial power supply 2
1 is rectified by a rectifier 22 and converted into a DC voltage. Power is supplied from a commercial power source 21. The DC voltage is passed through a filter circuit 23 to a capacitor 24 and an inductor 25.
The voltage is applied to the resonant circuit consisting of the semiconductor switching element 26 and the semiconductor switching element 26. The semiconductor switching element 26 switches at a frequency of several tens of kilohertz or more and produces high-frequency alternating current together with the resonant circuit. Inductor 25 is transformer 2
7, the high frequency alternating current generated in the inductor 25 is boosted to a high voltage by the transformer 27. The high voltage boosted by the transformer 27 is rectified into a DC high voltage by a high voltage rectifier circuit 28. The control circuit 32 provides a signal to the semiconductor switching element 26 to drive it. These electrical components constitute the inverter power supply 31. The DC high voltage rectified by the high voltage rectifier circuit 28 is supplied to the magnetron 2.
9 is applied between the anode and cathode. transformer 27
is provided with another winding 30, which supplies power to the cathode of the magnetron 29. The magnetron 29 can oscillate and generate microwaves when power is supplied to the cathode, the temperature of the cathode rises, and a high voltage is applied between the anode and the cathode. Microwaves generated by a magnetron are irradiated onto an object to be heated, such as food, to perform dielectric heating.

[0003] Since the inverter power supply 31 handles high-output power, the electrical components constituting it are accompanied by considerably large losses. For example, among the electrical components, the rectifier 23 and the semiconductor switching element 26 need to be fitted with aluminum fins to improve heat dissipation efficiency, and must be cooled with forced air along with other electrical components. Forced air cooling is motor 3
3, the fan 34 is rotated to generate cooling air.

FIG. 6 shows a high-frequency heating device main body 35 including an inverter power source 31, a magnetron 29, a motor 33,
This shows how the fans 34 are individually attached. As can be seen from the figure, in order to forcibly cool the inverter power supply 31 and the magnetron 29, it is necessary to supply air over a wide range. For this reason, a propeller fan capable of producing a relatively large amount of air is used as the fan 34. Further, an AC motor is used as the motor 33 for rotating the fan 34. Since forced cooling is performed using a combination of an AC motor and a propeller fan, the cooling configuration becomes extremely large.

[0005]

[Problems to be Solved by the Invention] However, the above conventional configuration has the following problems.

Firstly, since the inverter power source and motor are individually attached to the high-frequency heating device, there is a problem in that it requires a lot of assembly man-hours. That is, in order to supply necessary power to components such as an inverter power supply and a motor, it is necessary to connect each component to a power source using a lead wire. For this reason, components such as an inverter power supply and a motor are once attached to a high-frequency heating device, and these components are connected to a power source using lead wires. However, the wiring of these lead wires has to be done manually in a narrow space, which is labor-intensive and difficult to wire. In addition, when installing components such as an inverter power supply and a motor into a high-frequency heating device, each component has a variety of shapes.
Furthermore, each component must be wired with lead wires, making automatic assembly by a robot difficult and making it difficult to reduce assembly man-hours.

Second, unnecessary electromagnetic waves are radiated from the lead wires that supply the necessary power to components such as the inverter power supply, motor, or magnetron, and are transmitted to equipment such as televisions and radios around the high-frequency heating device. There was the issue of negative effects.

Thirdly, since the semiconductor switching devices constituting the inverter power supply generate a large amount of heat, it is necessary to attach fins for cooling. As a result, the fins become larger and occupy a larger area on the printed circuit board, making it difficult to downsize the printed circuit board.

The present invention solves the above problems and simplifies the assembly of a high-frequency heating device, reduces the number of assembly steps, reduces unnecessary radiation of electromagnetic waves, and realizes a highly reliable high-frequency heating device. It is intended for this purpose.

0010

[Means for Solving the Problems] In order to achieve the above object, the present invention provides the following means.

First, a fan for cooling the inverter power supply, a motor for driving the fan, and a cooling air generated by the fan are mounted on a printed circuit board on which electrical components constituting the inverter power supply are arranged. A guide is provided for guiding the printed circuit board, and the printed circuit board is housed in a conductive case.

Second, when attaching the motor to a printed circuit board, a support base for supporting the motor is made of a material with good thermal conductivity, and semiconductor switching elements and the like constituting the inverter power supply are mounted on the support base. Electrical components that generate heat are attached, and the support base is used as part of a guide for guiding cooling air generated by a fan.

[0013]

[Operation] First, by housing multiple components such as the inverter power supply, the fan, and the motor, which are some of the components of the high-frequency heating device, in a conductive case, they can be integrated into one component. can do. Therefore, by attaching the case to the high frequency heating device,
Multiple components can be attached to the high frequency heating device at one time. Furthermore, since the shape of the case can be made into any shape, it is possible to easily create a structure that is easy to assemble automatically. Further, by providing the inverter power source and the motor on the same printed circuit board, lead wires for connecting the power source and these components become unnecessary. Furthermore, since the components such as the printed circuit board and the magnetron are housed in a case made of conductive material, unnecessary radiation of electromagnetic waves can be shielded.

Second, when attaching the motor to the printed circuit board, a reinforcing plate for reinforcing the motor support is made of a material with good thermal conductivity, and the reinforcing plate is provided with semiconductor switching elements, etc. that constitute the inverter power supply. By attaching electrical components that generate heat and using the reinforcing plate as part of a guide for guiding cooling air generated by a fan, the following effects can be achieved. That is, as described in the conventional example, the fins used for cooling the semiconductor switching elements can be eliminated, and the space occupied by the fins can be reduced, so that the printed circuit board can be made smaller. For this reason, even when the printed circuit board on which the electrical components and motor that make up the inverter power source are attached, and the components of the high-frequency heating device such as the magnetron, are housed in a conductive case, the case must be made small. It has the effect of being able to.

[0015]

[Embodiments] Hereinafter, embodiments of the present invention will be explained with reference to the drawings.

1 to 4 are diagrams showing one embodiment of the present invention, in which 1 is a printed circuit board, 2 is a fan attached to a motor, 3 is a guide for guiding the wind generated by the fan 2, and 4 is a guide for guiding the air generated by the fan 2.
and 5 is a fin attached to a semiconductor switching element that is a part of the electrical component parts that make up the inverter power supply, 6 is a part of the electrical component parts that make up the inverter power supply 1, 7 is a conductive case, and 8 is a case. 7 is a handle used when attaching it to the main body of the high-frequency heating device; 9 is a magnetron that generates microwaves; 10 is a motor for rotating the fan 2; 11 is an electrical element component that constitutes an inverter power supply; a motor, a fan, and a guide. 12 is a support stand for supporting the motor 10; 13 is a printed circuit board on which is arranged;
is a semiconductor switching element that is a part of the electrical components that constitute the inverter power supply.

In the above configuration, FIG. 1 shows an inverter power supply 1 and electrical component parts 4 and 5 that constitute the inverter power supply 1.
, 6, a motor, a fan 2, and a printed circuit board 1 on which a guide 3 are arranged are housed in a single conductive case 7. In order to downsize the motor and fan 2, a DC motor is used instead of the conventional AC motor, and a sirocco fan is used instead of a propeller fan.

For cooling the printed circuit board 1, which is being miniaturized by increasing the mounting density of components, a sirocco fan that can generate a large amount of air pressure is suitable. Additionally, since a DC motor is used, a low-voltage DC power source is required. For this reason, a winding is provided in the transformer 6 among the electrical components that make up the inverter power supply 1, and low-voltage AC power is extracted.
This is rectified to obtain a DC power source.

As mentioned above, the transformer 6 and the motor 10, which are the electrical components constituting the inverter power supply 1, are
Since they are arranged on the same printed circuit board 1, the power obtained from the transformer 6 can be supplied to the motor 10 by transmitting it through the pattern provided on the printed circuit board 1, so no lead wire is required. . In addition, unnecessary electromagnetic waves radiated from the motor 10 and electric components including the transformer 6, semiconductor switching elements, and their cooling fins 4 and 5 are shielded by the conductive case 7, so that unnecessary electromagnetic waves such as televisions and radios are shielded. There will be no negative impact on the equipment. Furthermore, a handle 8 is attached to the conductive case 7. When installing it on the high frequency heating device main body, just attach this handle to the main body with screws.
Can be easily assembled using an automatic assembly machine.

FIG. 2 shows another embodiment. In the figure, a printed circuit board 11 on which electrical components 4, 5, 6, a motor, a fan 2, and a guide 3 constituting an inverter power supply 1, a motor, a fan 2, and a guide 3 are arranged in a conductive case 7, and a magnetron 9.
and are housed in one conductive case 7. The magnetron 9 generates microwaves, which are guided to an oven containing an object to be heated and heat the object, but some of the microwaves leak to the outside. Microwaves leaking to the outside are mainly radiated from the lead wire that connects the magnetron to the inverter power supply that energizes the magnetron. Therefore, if the magnetron 9 and the inverter power supply 1 are housed in the conductive case 7, unnecessary radiation due to microwaves can be reduced and reliability can be further improved.

FIG. 3 shows fins 4 and 5 to which semiconductor switching elements, which are one of the electric components constituting the inverter power supply, are attached, a transformer 6, a fan 2 for cooling these, and the fan 2. This figure shows a method of configuring a motor 10 for rotating a motor 10 and a guide 3 for guiding wind generated by a fan 2 on the same printed circuit board 11. As shown in the figure, the electrical component parts and the motor 10 are inserted from the same side of the printed circuit board 11 (the top side in the figure). Therefore, the electrical components and the motor can be soldered just by passing the printed circuit board 1 through the solder bath once. Also, replace fan 2 with motor 10
By inserting the guide 3 into the shaft of the fan 2 from above, and setting the guide 3 from the top of the fan 2, the electric components, motor 10, fan 2, and guide 3 can be inserted into the printed circuit board 11 with only vertical movement. This makes automatic assembly easy.

FIG. 4 shows the support stand 1 that supports the motor 10.
2 shows a configuration in which a semiconductor switching element 13, which is a part of the electrical component, is attached. Since the support base 12 is made of a material with excellent thermal conductivity, such as aluminum, the heat of the semiconductor switching element 13 is radiated through the support base 12. The support stand 12 is located at the bottom of the fan 2 and
It acts as part of the guide that guides the wind. Therefore, since sufficient air passes through the upper part of the support stand 12, the heat of the support stand 12 is efficiently radiated. That is, the semiconductor switching element 13 can be efficiently cooled. Moreover, the fins (for example, the fins 5 in FIG. 3) for cooling the semiconductor switching element 13 can be eliminated, and the space on the printed circuit board can be used effectively.

[0023]

[Effects of the Invention] As explained above, the high frequency heating device of the present invention has the following effects.

First, some of the components of the high-frequency heating device are an inverter power supply, a magnetron, a fan for cooling them, a motor for rotating the fan, and a guide for guiding the wind generated by the fan. By housing the guide for this purpose in a conductive case, these can be integrated into one component. Therefore, by attaching the case to the high-frequency heating device, a plurality of components can be attached to the high-frequency heating device at once. Furthermore, since the shape of the case can be made into any shape, it is possible to easily create a structure that is easy to assemble automatically. Therefore, there is an effect that the number of assembly steps can be reduced and costs can be reduced. Further, by providing the inverter power source and the motor on the same printed circuit board, lead wires for connecting the power source and these components become unnecessary. Furthermore, since the components such as the printed circuit board and the magnetron are housed in a case made of conductive material, unnecessary radiation of electromagnetic waves can be shielded and reliability can be improved.

Second, when attaching the motor to a printed circuit board, a reinforcing plate for reinforcing the motor support is made of a material with good thermal conductivity, and the reinforcing plate is provided with semiconductor switching elements, etc. that constitute the inverter power supply. By attaching electric component parts that generate heat and using the reinforcing plate as part of a guide for guiding cooling air generated by a fan, it can be used to cool semiconductor switching elements. You can eliminate the fins. Therefore, since the space occupied by the fins can be reduced, the size of the printed circuit board can be reduced. For this reason, even when the electric components making up the inverter power supply, the printed circuit board with the motor attached, and the components of the high-frequency heating device such as the magnetron are housed in a conductive case, the case must be made small. It has the effect of being able to

[Brief explanation of drawings]

FIG. 1 is a partially cross-sectional external perspective view of a high-frequency heating device according to an embodiment of the present invention.

FIG. 2 is a partially cross-sectional external perspective view of a high-frequency heating device according to another embodiment of the present invention.

FIG. 3 is an external perspective view showing the assembled configuration of a printed circuit board of a high-frequency heating device in another embodiment of the present invention.

FIG. 4 is an external perspective view showing the assembled configuration of a printed circuit board of a high-frequency heating device in another embodiment of the present invention.

[Figure 5] Circuit diagram showing the circuit configuration of a conventional high-frequency heating device

[Fig. 6] Perspective view of a conventional high-frequency heating device

[Explanation of symbols]

1 Inverter power supply 2 Fan 3 Guide 4, 5 Fin 6　Trans 7 Case 9 Magnetron 10 Motor 11 Printed circuit board 12 Motor support stand 13 Semiconductor switching element

Claims (2)

[Claims] 1. An electric power source comprising an inverter power source for driving a magnetron, a motor for driving a fan for cooling the inverter power source, and a guide for guiding cooling air generated by the fan, and comprising an inverter power source. A high-frequency heating device having a structure in which element parts, the motor, and the guide are arranged on the same printed circuit board, and the printed circuit board is housed in a case made of a conductive material. 2. A support base for supporting the motor is constructed using a material with good thermal conductivity, and electrical components that generate heat such as semiconductor switching elements constituting an inverter power supply are attached to the support base, and 2. The high-frequency heating device according to claim 1, wherein the support base is used as a part of a guide for guiding cooling air generated by a fan.