JP2001110559A - High frequency heating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a high frequency heating apparatus having excellent impact resistance by equipping with the steel plate of U-shape joining form to make function ground for the inverter power source substrate. SOLUTION: The shape of the electric parts mounting board 49 to join the inverter power source substrate 39 with screws and so, is formed in U-shape by bending. According to the moving construction of U-shaped part by its elasticity, the impact is absorbed by the elasticity of the U-shaped electric parts mounting board 49, even the impact force to the main body of high frequency heating apparatus has effects to the high frequency power source. The inverter power source substrate 39 can obtain enough impact resistance without causing damages, by receiving impact force by whole inverter power source substrate 39 without concentration of impact force at the one point of joining part likes screws.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency heating apparatus such as a microwave oven and a microwave oven, which fastens a wiring board on which electric components are mounted to a component mounting plate formed of a steel plate with screws or the like. It relates to the shape of the part.

[0002]

2. Description of the Related Art Conventionally, this kind of high-frequency heating apparatus has a configuration as shown in FIGS. 6 and 7 which was invented prior to the present invention.

FIG. 6 is a perspective view showing the configuration of a conventional high-frequency heating device viewed from the bottom.

In FIG. 6, there is a motor mounting guide 3 near the center of the bottom wall 2 of the heating chamber 1 of the heating chamber 1 of the main body of the high-frequency heating apparatus. There is material 5. The electric component mounting plate 6 for pressing and fixing the surface heater 4 by the heat insulating material 5 is fixed by fastening the mounting plate 8 for mounting the pan supporter motor 7 to the motor mounting guide 3 by screws. . Further, the propeller fan 9 and the sirocco fan 10 of the blower, the inverter power supply board 11, and the control unit 12 are mounted on the box-shaped electric component mounting plate 6, respectively.
15 is installed. The magnetron 16 of the oscillator, which is high-frequency heating means, is also installed at a position where it is efficiently cooled by the sirocco fan 10 on the electric component mounting plate 6. The electric component mounting plate 6 on which these electric components are installed is fixed by screwing the bottom plate 17 to the flange portion 18 on the front wall of the heating chamber and the flange portion 19 on the rear wall of the heating chamber with screws.

FIG. 7 is a sectional view of a conventional high-frequency heating device.

As shown in FIG. 7, the magnetron 16 of the above-described high-frequency generating means is attached to a flange 21 extending downward from a rear wall 20 of the heating chamber. The high frequency is guided to the heating chamber 1 by the waveguide 22 installed on the rear wall 20 of the heating chamber. The propeller fan 9 of the air blower and the inverter power supply board 11 of the power supply section are arranged on the inverted U-shaped box-shaped electric component mounting plate 6 in a state of being suspended from the mounting plates 13 and 14, respectively. Further, the turntable 23 is driven by the dish receiving table motor 7 (not shown).
Note that a tubular tube heater 25 is provided on the upper wall surface 24 of the heating chamber 1.
However, the planar surface heater 4 described above is provided on the bottom wall surface 2 so as to electrically heat the object to be heated.

The above-mentioned inverter power supply board 11 needs to be grounded to the high frequency heating device main body chassis in order to supply rectified power to the magnetron 16 of the high frequency generating means. Therefore, the electric component mounting plate 6 is formed of a steel plate, is subjected to drawing processing so as to contact the ground point of the inverter power supply board 11, and the functional component ground is fastened to the electric component mounting plate 6 by screwing. Was secured.

[0008]

FIG. 8 shows a structure for mounting an inverter power supply board 11 of a conventional high-frequency heating apparatus.
This will be described with reference to FIG. FIG. 8A is a perspective view of the inverter power supply board 11. The inverter power supply board 11 is mounted with heavy objects such as a radiation fin 26 for cooling the switching element and a high-voltage transformer 27 necessary for supplying rectified high-voltage power to the magnetron 16. Approximately 600 g. The inverter power supply board 11 is screwed (not shown) by mounting holes 28, 29, 30 provided on the inverter power supply board 11 and mounting bosses (not shown) provided on the mounting plate 14 made of resin. It is fixed with. Inverter power supply board 11
The unit products of the mounting plate 14 and the mounting plate 14 are provided on the mounting plate 14 at openings formed in the electrical component mounting plate 6 so that a space is formed between the electrical component mounting plate 6 and the mounting plate 14 for thermal insulation of the surface heater 4. It is installed on the main body of the high-frequency heating device by fitting the claws. The electric component mounting plate 6 is formed by drawing only the ground point portion 31 of the inverter power supply board 11 and
And the ground point is fastened with a screw 32 to ground. The bottom plate 17 supports a cover for covering electric components installed on the electric component mounting plate 6 and a main body.

However, in the configuration of the conventional high-frequency heating device, only the ground point portion 31 is firmly connected between the inverter power supply board 11 and the rigid electric component mounting plate 6 which is firmly connected to the high-frequency heating device main body. Therefore, the impact force received by the high-frequency heating device main body due to dropping during transportation or the like is concentrated on one point of the ground point portion 31 when viewed from the inverter power supply board 11. As a result, as shown in FIG. 8B, with the earth point 31 serving as a fulcrum, the ends (particularly, both ends) of the inverter power supply board 11 vibrate up and down as shown by arrows, and the proof stress of the wiring board made of Fenol paper is reduced. Over the inverter power supply board 11
There has been a problem that the device may be destroyed, the pattern on the substrate may be disconnected, and the function of the high-frequency heating device may be impaired.

[0010]

According to the present invention, in order to solve the above-mentioned problems, a grounding portion 31 of the inverter power supply board 11 is provided to provide a functional ground for the inverter power supply board 11.
The shape of the fastening portion of the electrical component mounting plate 6 for fastening the electrical component mounting plate 6 formed of the steel plate and the steel plate with the screw 32 is formed into a U-shape by bending, and the inverter power supply board 11 is formed.
Are movable in one direction by the elasticity of the U-shaped portion of the electric component mounting plate 11.

Further, the U-shaped shape of the electric component mounting plate 6 is formed by cutting out the electric component mounting plate 6 and forming a U-shaped portion by bending, and the open end of the U-shaped portion corresponds to the cut-out surface. A configuration is provided in which an extending portion is provided which is in contact with the notch, and which is in contact with the notched cross section.

According to the above invention, the inverter power supply board 1
The ground point portion 31 is fixed to the U-shaped portion of the electric component mounting plate 6 by fastening it with screws or the like. Electric component mounting plate 6
The U-shaped elastic force makes it possible to receive an impact force on the entire inverter power supply board 11 without concentrating on one point of the ground point portion 31.
1 has no damage, and can solve the problem that the pattern on the substrate is disconnected and the function of the main body of the high-frequency heating device may be impaired.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A high-frequency heating apparatus according to a first aspect of the present invention has a heating chamber having an opening at a front surface for heating an object to be heated, and a machine room for accommodating electric components for driving the high-frequency heating apparatus body. The machine room includes an oscillator for high-frequency heating the object to be heated, and an electric component mounting plate formed of a steel plate on which a high-frequency power supply for supplying high-frequency power to the oscillator is provided. Is formed into a U-shape by bending the portion of the electric component mounting plate to be fastened to the electric component mounting plate with a screw or the like, and the U-shaped portion of the electric component mounting plate in one direction It is configured to be movable by the elasticity of. By doing so, even if an impact force applied to the high-frequency heating device main body is applied to the high-frequency power supply, the impact force is absorbed by the elastic force of the U-shaped portion of the electric component mounting plate, and the high-frequency power supply Since the high-frequency power supply can receive an impact force without concentrating an impact force on one fastening portion of a screw or the like, the high-frequency power supply has no damage and provides a high-frequency heating device excellent in impact resistance. can do.

According to a second aspect of the present invention, there is provided a high-frequency heating apparatus in which a U-shaped portion is formed by cutting out an electric component mounting plate and performing a bending process, and an open end of the U-shaped portion is cut out. And an extended portion that comes into contact with the notch section. With this configuration, when the electric component mounting plate and the high frequency power supply are fastened with a screw or the like, the U-shaped portion is prevented from being depressed from the cutout surface of the electric component mounting plate and being prevented from being twisted and deformed by the tightening torque. It is possible to provide a high-frequency heating device which is excellent in impact resistance without impairing workability.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is a perspective view of a high-frequency heating device according to one embodiment of the present invention, and FIG. 5 is a cross-sectional view of the high-frequency heating device in FIG. FIG. 4 is a bottom view of the high-frequency heating device with the bottom plate removed.

In FIG. 3, a heating chamber 34 is provided inside a high-frequency heating apparatus main body 33, and a door 35 for taking in and out an object to be heated is provided on a front surface of the heating chamber 34. Note that an operation unit 36 is formed integrally with the door 35 below the door 35. Cabinets 37 are provided on the upper surface and the left and right side surfaces of the heating chamber 34. Cabinet 37
No exhaust port is provided so that the surface of the wall is not overheated even when installed close to a wall or the like.

Next, the internal configuration will be described with reference to FIGS. In FIG. 4, a blower 38 is provided on the front right side of the main body, an inverter power supply board 39 serving as a high-frequency power supply is provided on the side, and a magnetron 40 serving as an oscillator is provided on the rear side.
And a guide 41 for blowing air to the heating chamber 34, a motor 42 at the center, and a control board 43 at the rear of the main body. The cooling air from the blower 38 is
The first rectifying section 44a provided on the rectifying guide 44 and the second rectifying section 44a
Are diverted to the inverter power supply 39 and the magnetron 40, and are cooled respectively. Further, a part of the cooling air diverted by the second rectification unit 44b cools the control board 43 and the motor 42. The rectifying guide 44 is provided with a partition 44c for separating intake air and exhaust gas in order to improve cooling performance.

In FIG. 5, a tubular tube heater 46 is provided on an upper wall surface 45 of the heating chamber 34, and a planar heater 48 is provided on a bottom wall surface 47. An inverter power supply board 39, which is a power supply unit of the high-frequency generation means, is arranged in an inverted U-shaped box-shaped electric component mounting plate 49 made of a steel plate in a suspended state by a mounting plate 50 made of a resin. On the right side of the inverter power supply board 39, a sirocco fan 51, which is a centrifugal blower constituting a blower 53, a spiral casing 52, and a shading motor 38 are installed in a suspended state. A rectifying guide 44 is provided between the blower 53 and the inverter power supply board 39 for efficient cooling. The motor 42 for driving the turntable 51 is mounted on an electric component mounting plate 49 via a mounting plate (not shown) in order to avoid heat conduction from the surface heater 48. Thus, these components arranged on the electric component mounting plate 49 are
, And a machine room 55 is constituted by the electric component mounting plate 49 and the bottom plate 54.

Here, the air blowing path by the air blowing device 53 in FIG. 5 will be described. The cooling air blown by the blower 53 from the suction port 54 a provided in the bottom plate 54 and blown is supplied to the inverter power supply board 39 and the control board 4.
3. After cooling the motor 42, the rear wall of the heating chamber (not shown)
The air is exhausted from an exhaust port (not shown) provided in the lower part of the air conditioner. Further, a heat insulating plate 57 is provided between the right side surface 56 of the heating chamber and the cabinet 37, and a part of the air generated by the blower passes between the right side wall 56 of the heating room and the heat insulating plate 57 and passes through the right side of the heating room. In this configuration, air is blown into the heating chamber 34 from an opening (not shown) provided in the wall.

Next, the mounting structure of the inverter power supply board 39 to the electric component mounting plate 49 according to the present invention will be described with reference to FIGS. Inverter power supply board 39
Are the mounting holes 5 provided on the inverter power supply board 39.
8, 59, 60 and fixing bosses 61, 62, 63 provided on the mounting plate 50 made of resin are fixed to the mounting plate 50 with screws (not shown). The unit product of the inverter power supply board 39 and the mounting plate 50 made of resin is formed so that a space is formed between the electric component mounting plate 49 and the mounting plate 50 for thermal insulation of the surface heater 48, and the electric component mounting plate 49 is formed.
The claw 65 provided on the mounting plate 50 is fitted into the opening 64 provided on the electric component mounting plate 49 so that the mounting plate 49 made of resin is mounted on the portion where the temperature rise is low. I have. In order to secure the functional ground of the inverter power supply board 39, the ground point portion 66 of the inverter power supply board 39 is formed by cutting out a flat portion of a steel component mounting plate 49, and bending and forming a U-shaped screw. A portion 67 is formed, and a ground is formed by fastening the portion 67 to the inverter power supply board 39 with a screw.

Next, the forming method and function of the U-shaped screw fastening portion 67 will be described with reference to FIGS. 1 (a), 1 (b) and 1 (c). As shown in FIG. 1 (b), the oblique line portion of the flat portion of the electric component mounting plate 49 is punched, and
The U-shaped screw fastening portion 67 is formed by cutting the portion to form the outer shape of the fastening portion and bending a predetermined portion. FIG. 1C is a view showing the function of a screw fastening portion 67 formed in a U-shape according to the present invention. The main impact of the high-frequency heating device during transportation is mainly in the vertical direction. When the vertical impact force is applied to the inverter power supply board 39, the U-shaped screw fastening portion 67 is displaced in the Y direction as shown in FIG. It is possible to avoid concentration of stress on the earth point portion 66 of the inverter power supply board 39 by moving. Conventionally, since the earth point portion 66 is firmly fastened to the electric component mounting plate 50, stress concentrates on this portion, and the shearing stress of the commonly used paper base phenolic resin copper clad laminate becomes large. 12-15
When an impact force exceeding kgf / mm ² is applied, there is a risk that the pattern on the substrate may be broken. However, in the case of the screw fastening portion 67 of the present invention, the U-shaped screw fastening portion 67 is formed in accordance with the impact force.
Is displaced, so that a high-frequency heating device that is robust against impact force without stress concentration on the ground point portion 66 can be realized.

Further, as shown in FIGS. 1 (a) and 1 (b), the U-shaped screw fastening portion 67 of the present invention extends so as to be in contact with the cutout surface of the electric component mounting plate 49. In addition to providing the portion d, a portion e is provided which also comes into contact with the end surface (cross-sectional portion) of the cutout surface. By doing so, when fastening the inverter power supply board 39 to the electric component mounting plate 49 with screws, the U-shaped screw fastening portion 67 does not escape, and the fastening portion 67 is twisted and deformed by the tightening torque. It is possible to realize the screw fastening portion 67 which can be prevented from being performed and which is excellent in assemblability.

[0024]

As described above, the high-frequency heating device according to the first aspect of the present invention has the U-shaped portion of the electric component mounting plate even when an impact force applied to the high-frequency heating device body is applied to the high-frequency power supply. The high-frequency power supply is not damaged because the impact force is absorbed by the elastic force and the entire high-frequency power supply can receive the impact force without concentrating the impact force at one fastening portion such as a screw of the high-frequency power supply. Sufficient impact resistance can be obtained.

According to the second aspect of the invention, when the electric component mounting plate and the high-frequency power source are fastened with screws or the like, the U-shaped portion is depressed from the cutout surface of the electric component mounting plate or twisted due to the tightening torque. It is possible to provide a high-frequency heating device that can prevent deformation and has excellent impact resistance without impairing workability.

[Brief description of the drawings]

1A is a perspective view of a screw fastening portion of a high-frequency heating device according to an embodiment of the present invention. FIG. 1B is a front view and a longitudinal sectional view of a screw fastening portion of the high-frequency heating device. Sectional view showing how the impact force of the screw fastening part is absorbed

FIG. 2 is an exploded perspective view showing a main part assembly configuration of the high-frequency heating device.

FIG. 3 is an external perspective view of the high-frequency heating device.

FIG. 4 is a bottom view of the high-frequency heating device excluding a bottom plate.

FIG. 5 is a sectional view of the high-frequency heating device (section AA).

FIG. 6 is an exploded perspective view showing a main part assembly configuration of a conventional high-frequency heating device.

FIG. 7 is a sectional view of the high-frequency heating device.

FIG. 8A is an external perspective view of a high-frequency power supply of the high-frequency heating device. FIG. 8B is a cross-sectional view illustrating a state in which an impact force is concentrated on a screw fastening portion of the high-frequency heating device.

[Explanation of symbols]

 34 Heating chamber 39 Inverter power supply board (high frequency power supply) 40 Magnetron (Oscillator) 49 Electrical component mounting plate 55 Machine room d Extension part e Site

Claims (2)

[Claims] 1. A heating chamber having an opening at a front surface for heating an object to be heated, and a machine room for accommodating electric parts for driving a high-frequency heating device main body, wherein the object to be heated is housed in the machine room. An oscillator for high-frequency heating and an electrical component mounting plate formed of a steel plate for mounting a high-frequency power supply for supplying high-frequency power to the oscillator, wherein the high-frequency power source is fastened to the electrical component mounting plate with screws or the like. A high-frequency heating apparatus in which the shape of the electric component mounting plate is formed into a U-shape by bending, and the high-frequency power supply is movable in one direction by elasticity of a U-shaped portion of the electric component mounting plate. 2. A U-shaped configuration of an electric component mounting plate, wherein a portion to be fastened to a high-frequency power source is cut out to form a U-shaped portion, and an open end of the U-shaped portion is in contact with the cut-out surface. And a portion which comes into contact with the notched cross section.
The high-frequency heating device as described.