JPH0831562A - High frequency heating apparatus - Google Patents

Abstract

PURPOSE:To improve only a cooling effect of a magnetron without affecting any other else and provide high output and retain high reliability by an orifice structure of a fan guide, regarding magnetron cooling for a high frequency heating apparatus. CONSTITUTION:A holding part 29 to which an inverter printed substrate 28 is attached is installed in parallel to a cooling passage 18 of a magnetron 10 and a control plate 32 is composed at a position corresponding to the extended line of the cooling passage 18 in the direction of the cooling passage 18 in an orifice 31 of a fan guide which is unitedly formed with the holding part 29 and assembled into almost L-shape in the lower part of the holding part 29. Consequently, a portion of whirling current which escapes to the outside of almost L-shaped space 16 without contributing to cooling the magnetron 10 is supplied to the cooling passage 18 direction and thus a magnetron 10 cooling function can be improved.

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 device for a microwave oven or the like, and more particularly to a cooling structure for a magnetron or an inverter power source for heating a dielectric such as food or a catalyst by using microwaves.

[0002]

2. Description of the Related Art Conventionally, this type of high-frequency heating device represented by a microwave oven is composed of a magnetron and an inverter power supply for driving the magnetron, and as microwave oven performance, speedup of cooking, operability, and defrosting are performed. There is a strong demand for performance improvements in the essential aspects such as performance improvements.

A conventional high-frequency heating device of this type is shown in FIG.
As shown in FIG. 2, the main body 1 is composed of a heating chamber 2 and a machine chamber 3, and the machine chamber 3 is a space surrounded by the side plate 4, the back plate 5, the operation portion 6 and the main body cover 7 of the heating chamber 2. A waveguide 9 is provided in a mounting portion 8 on the rear surface of the heating chamber 2, a magnetron 10 is fixed to an end of the waveguide 9, and a semiconductor switching element 11 is provided in the machine chamber 3 such as a high voltage transformer 12 and the like. A holding portion 14 to which an inverter printed circuit board 13 having element parts is attached, and a fan guide 15 and the like formed integrally with the holding portion 14 and having a substantially L shape after the inverter printed circuit board 13 is attached. There is. Regarding the positional relationship between the magnetron 10, the inverter printed circuit board 13 and the fan guide 15, the magnetron 10 is located in a substantially L-shaped space 16 constituted by the inverter printed circuit board 13 and the fan guide 15 in terms of cooling configuration, and the heat radiation fan 17 of the magnetron 10 is positioned. The cooling passage 18 and the holding portion 14 are arranged in parallel with each other, and are arranged so that the blower passage 21 of the axial fan 20 in the orifice 19 provided in the fan guide 15 can be entered. As a result, the ventilation passage 21 of the substantially L-shaped space 16 is formed by a space surrounded by the side plate 4 of the heating chamber 2, the left and right side surfaces of the holding portion 14 and the mounting portion 8, and the front side of the ventilation passage 21. A fan guide B (not shown) is separately provided in the front gap between the guide 15 and the magnetron 10. Also,
In order to prevent fogging of the door 22 and improve the efficiency of the oven, there is a model that introduces a part of the cooled air into the heating chamber 2, but the structure is as shown in FIG. A plurality of small holes 23 are provided in the vicinity of the door 22, a heat insulating plate 25 having an air intake 24 is provided so as to cover the side plate 24, and the heating chamber 2 and the machine room 3 are communicated with each other via the heat insulating plate 25. At that time, the position of the air intake 24 is substantially L-shaped space 16
It is provided on the surface.

[0004]

However, in order to realize speeding up of cooking, that is, high output, with the above-mentioned conventional structure, the loss of the magnetron 10 is increased and the semiconductor switching element mounted on the inverter printed circuit board 13 is used. It is necessary to deal with the increase in loss of 11, the high voltage transformer 12, the high voltage diode (not shown), and the like. Regarding the latter inverter power supply, it has become possible to cope with it by increasing the frequency of the inverter power supply to increase the inverter efficiency and developing low loss devices. However, with respect to the former magnetron 10, for example, when the output is increased by 100 W, the temperature rises by about 30 K when the load is low, and the conventional cooling configuration has a problem that the temperature range that guarantees the reliability cannot be afforded. Was there. Further, in order to solve the above problems by the conventional technique, increasing the rotation speed of the axial fan 20 and increasing the fan size increase the size restriction of the main body 1, the problem of cost increase, and the noise. I have a problem.

The present invention solves the above-mentioned conventional problems. In the arrangement of the magnetron in the substantially L-shaped space of the holding part and the fan guide, the cooling performance to the inverter power source side is not deteriorated to a substantially L level. A control plate that effectively guides the cooling air that swirls the character space to the cooling passage of the magnetron is provided in the orifice to achieve high output based on the conventional configuration and to improve the cloudiness of the door. The purpose is to achieve both.

[0006]

In order to achieve the above object, the high frequency heating apparatus of the present invention has the following constitution.

That is, a holding portion for mounting and holding the inverter printed circuit board is arranged in parallel with the cooling passage of the magnetron having the radiation fins, and the holding portion is integrally formed with the holding portion below the cooling passage to form a substantially L-shaped inside the orifice. Is provided with a fan guide having an axial fan, and at least one control plate is integrally formed with the fan guide at the orifice corresponding to the extension of the cooling passage.

Further, a holding portion for mounting and holding the inverter printed circuit board is arranged in parallel with the cooling passage of the magnetron having the heat radiation fins, and is integrally molded with the holding portion below the cooling passage so as to be substantially L-shaped in the orifice. Is provided with a fan guide having an axial flow fan, and a control plate is integrally formed with the fan guide at the orifice on the end face extension of the cooling passage facing the mounting portion of the magnetron.

Further, a holding portion for mounting and holding the inverter printed circuit board is arranged in parallel with the cooling passage of the magnetron having the radiation fins, and is integrally molded with the holding portion below the cooling passage to form a substantially L-shape inside the orifice. Is provided with a fan guide having an axial fan, and a partition plate crossing the orifice is provided between the fan guide and the cooling passage.

The height of the orifice portion of the partition plate is made higher than that of the mounting portion. In addition, a heat insulating plate is provided in parallel with the side plate in a machine chamber composed of a heating chamber, a machine room, etc., and a side plate and a back plate of the heating chamber, an operation section and a body cover, and a plurality of small plates are provided on the side plate. An air inlet is provided in the hole and the heat insulating plate, the heating chamber and the machine chamber are communicated with each other by a heat insulating material, the position of the air inlet is arranged in a substantially L-shaped space surface, and the opening is communicated with the air inlet. A control plate having a section is provided.

Further, a heat insulating plate is provided in parallel with the side plate in a machine chamber which is composed of a heating chamber, a machine chamber and the like, and is constituted by a side plate and a back plate of the heating chamber, an operating portion and a main body cover. An air inlet is provided in the plurality of small holes and the heat insulating plate, the heating chamber and the machine chamber are connected by a heat insulating plate, the position of the air inlet is arranged in a substantially L-shaped space surface, and a part of the orifice is formed. An opening or a notched inlet portion is provided, and an air intake guide for leading to the air inlet is provided on the outer periphery of the orifice, upstream of the inlet portion.

Further, a guide plate is provided in the gap between the heat insulating plate and the holding portion. Further, the air inlet is made to face the blowout flow of the axial fan.

[0013]

According to the present invention, with the above-described structure, only the flow of the swirling flow of the axial fan rotating in the orifice downstream of the orifice opening to the magnetron side is provided at an arbitrary position below the cooling passage. Part of the flow is changed to upward flow, and as a result, more flow is introduced into the cooling passage, which has less cooling flow with respect to the magnetron, and is made uniform, which effectively acts on the radiation fins.

Further, since the control plate which receives the swirling flow is positioned on the extension of the end face of the magnetron cooling passage on the holding portion side with respect to the rotating direction of the axial fan, the swirling flow in the magnetron side orifice almost flows upward. Can be changed to
The air is blown to the cooling passage of the magnetron.

Further, a part of the upward flow of the control plate and the partition plate is guided to the air intake of the heat insulating plate.

[0016]

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

FIG. 1 shows a holder 29 in which a main body 1 of a high-frequency heating apparatus is attached with a magnetron 10 and an inverter printed circuit board 28 having electric element parts such as a semiconductor switching element 26 and a high-voltage transformer 27 corresponding to high output.
And a state in which a fan guide 30 that is integrally molded with the holding part 29 and is attached to the inverter printed circuit board 28 and then assembled into a substantially L shape is attached. Attached. The basic arrangement is the same as in the conventional example, and as shown in FIG. 2, an orifice 31 is provided in the fan guide 30 so as to surround the axial fan 20, and its diameter is approximately the width of the holding portion 29 and the position with respect to the magnetron 10. The relationship is such that one end is near the mounting portion 8 of the magnetron 10. The magnetron 10 is provided in the orifice 31.
Two control plates 32 and 33 are integrally formed with the fan guide 30 at positions facing the extension of the cooling passage 18. Both are downstream of the axial fan 20 and are plate-shaped and project toward the center of the orifice 31. One is the position facing the main body cover 7 side of the cooling passage 18, and the other is the cooling passage 18. It is provided at a position facing the heating chamber 2 side. The height dimensions of the control plates 32 and 33 are such that they do not overlap each other.

In the above structure, when the axial fan 20 rotates, the cooling air (shown by the solid line arrow) is sucked from the intake hole 35 provided in the main body bottom plate 34 below the fan guide 30, and the intake area does not change. The amount of air supplied to the downstream side of the flow fan 20 does not change, and as a result, the cooling air supplied to the inverter printed circuit board 28 is not affected. On the other hand, with respect to the cooling air originally supplied to the magnetron 10 side, the swirling flow that coincides with the rotation direction of the axial fan 20 is changed to the upward flow by the two control plates 32 and 33 in the orifice 31 respectively, The air is sent to the cooling passage 18 of the magnetron 10 corresponding to the position of the control plate. That is, the cooling passage 18 of the magnetron 10 can be arbitrarily blown to a place having a small amount of cooling air, the efficiency of the heat radiation can be improved, and the wasteful flow not contributing to the cooling can be efficiently collected. Further, since it can be integrally molded with the fan guide 30, the cost is not increased, and further, the cooling of the magnetron 10 can be improved without affecting noise and other performances as much as possible.

Further, in the embodiment shown in FIG. 3, the axial fan 20 rotates counterclockwise, while the extension of the end face of the cooling passage 18 of the magnetron 10 on the side facing the mounting portion 8 is extended. A control plate 36 is provided at the position of the orifice 31 in parallel with the end surface of the cooling passage 18. The length of the control plate 36 that protrudes inside the orifice 31 is determined by the ease of mounting the axial fan 20 and the convenience of molding. Further, in the height direction, it is possible to reach the end face of the magnetron 10 from a position directly above where the axial fan 20 does not melt, but it is not possible to set the height to the end face of the magnetron 10 in terms of easy attachment to the main body 1. A gap is formed to some extent with the end face of the magnetron 10. However, usually through the generally L-shaped space 16,
Main body 1 with almost no contribution to cooling the magnetron 10.
The swirling flow discharged to the outside is captured by the control plate 36, converted into an upward flow and sent to the cooling passage 18, so that the cooling performance can be improved more than in the first aspect. Further, FIG. 4 shows a state in which the holding portion 29 and the fan guide 30 are attached to the main body 1, and then the partition plate 37 is attached as a separate component on the conventional orifice 19.
With respect to the counterclockwise rotation, the straight portion 38 of the partition plate 37 is aligned with the extension of the side surface of the cooling passage 18 facing the mounting portion 8 of the magnetron 10 like the control plate 36. As a result, the swirling flow is completely partitioned off at the upper portion of the orifice 19, which has the same effect as in the above embodiment. Further, as shown in FIG. 5, by making the height of the orifice portion 39 of the partition plate 37 higher than that of the mounting portion 8, a part of the cooling flow leaking from the mounting portion 8 side can be collected, and further cooling effect can be obtained. it can.

Next, another embodiment will be described with reference to FIGS. 6 to 9. 6 is different from the embodiment in FIG. 3 in that the main body 1 has a heat insulating plate 25, the air intake port 24 is provided in the substantially L-shaped space 16 surface, and the control plate 36 provided in the orifice 31 has an air intake port. Since the opening 40 is provided so as to face 24, a part of the swirling flow that is deflected upward by the control plate 36 is guided by the configuration to the air intake port 24 without being deflected through the opening 40. With the control plate 36, the cooling effect of the magnetron 10 is improved, and the clouding prevention effect of the door 22 is also obtained.

Further, in FIG. 7, the orifice 31 is provided with an inlet portion 41 which opens in the vicinity of the lower portion of the mounting portion 8 and an air intake guide 42 for guiding the cooling air blown out from the inlet portion 41 to the air inlet 24 is provided as an orifice. Since it is provided on the outer circumference of 31, the swirling flow escaping from the gap 43 between the mounting portion 8 and the orifice 31 can be added as wind for preventing fog of the door 22, and the air intake guide 42 effectively enables the air intake port. 24 can be supplied.

Next, FIG. 8 shows another embodiment. Holding part 29
When mounting the block integrally molded with the fan guide 30 to the main body bottom plate 34, the heat insulating plate 2 is considered in consideration of thermal influence.
5, a gap 43 is provided between the heat insulating plate 25 and the holding portion 29, which is located on the downstream side of the air intake 24 in the rotation direction of the axial fan 20. A guide plate 44 is provided in the height direction. As a result, the swirling flow discharged to the outside of the main body 1 through the gap 43 without contributing to the cooling of the components or the prevention of fogging of the door 22 is interrupted by the guide plate 44 and supplied to the air intake port 24. Further, the guide plate 44 comes into contact with the heat insulating plate 25, but there is no problem because the cooling air always passes through the surface of the guide plate 44. In the embodiment shown in FIG. 9, the air intake 45 provided in the heat insulating plate 25 is opposed to the blowout flow of the axial fan 20 in the configuration of FIGS. To make it easier to enter the door 22
Anti-fogging effect and control plate 36 magnetron 10
It is possible to sufficiently improve the cooling performance.

[0023]

As described above, according to the high frequency heating apparatus of the present invention, the following effects can be obtained.

At least one control plate projecting toward the center of the orifice is formed integrally with the orifice of the fan guide at a position facing the extension of the cooling passage of the magnetron as a part of the fan guide. One is a control plate parallel to the end face of the cooling passage that is integrally formed as a part of the fan guide at a position facing the extension of the end face of the cooling passage on the side facing the magnetron mounting part. Since a partition plate that crosses the orifice is provided in the substantially L-shaped space with respect to the fan guide, the swirling flow in the orifice formed by the axial fan is partially or almost turned upward by the control plate or the partition plate. The
The air will be blown to the cooling passage of the magnetron located above it. In addition, when there is no control plate or partition plate, the cooling flow leaked from the gap between the air passage and the main unit is added, improving the cooling performance of the magnetron, increasing the rotational speed of the axial fan, and newly cooling. High output can be realized based on the conventional configuration without developing the configuration. Further, the cooling performance to the inverter printed circuit board side is not affected because the intake and exhaust passages do not change due to the characteristics of the axial fan.

On the other hand, in the case of a main body having a heat insulating plate on the side wall of the heating chamber and introducing cooled air into the heating chamber from an air inlet provided in the heat insulating plate to prevent fogging of the door, one is the above control plate. , An opening that communicates with the air intake is provided, and one is that the fan guide is provided with an air intake guide that leads to the air intake from the inlet provided on the orifice on the upstream side of the control plate. A guide plate is provided in the gap between the heat insulating plate and the holding part so as to close the downstream side, and the other one is such that the shape of the air intake is made to face the blowout flow of the axial fan. It is possible to suppress the reduction in the fogging prevention effect on the door due to the deflection of the swirling flow of the axial fan toward the upward flow, and it is possible to achieve both improvement of the cooling performance of the magnetron.

[Brief description of drawings]

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

FIG. 2 is a perspective view of a main part of the high-frequency heating device.

FIG. 3 is a cross-sectional view of a high frequency heating device according to another embodiment of the present invention.

FIG. 4 is a perspective view of a main part of the high-frequency heating device.

FIG. 5 is a perspective view of a high-frequency heating device showing another embodiment.

FIG. 6 is a perspective view of a high-frequency heating device according to another embodiment of the present invention.

FIG. 7 is a perspective view of a main part according to another embodiment of the present invention.

FIG. 8 is a perspective view of a main part according to another embodiment of the present invention.

FIG. 9 is a perspective view of a main part according to another embodiment of the present invention.

FIG. 10 is a perspective view of a high-frequency heating device according to a conventional example.

FIG. 11 is a perspective view of a high-frequency heating device according to another conventional example.

[Explanation of symbols]

 2 Heating chamber 3 Machine room 4 Side plate 5 Back plate 6 Operation part 7 Main body cover 8 Mounting part 10 Magnetron 17 Radiating fin 18 Cooling passage 20 Axial fan 23 Small hole 24, 45 Air inlet 25 Heat insulating plate 28 Inverter printed circuit board 29 Holding Part 30 Fan guide 31 Orifices 32, 33, 36 Control plate 37 Partition plate 39 Orifice part 40 Opening 41 Inlet 42 Air intake guide 43 Gap 44 Guide plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Villa Daisuke 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor, Yuji Nakabayashi 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (72) Inventor Makoto Shibuya 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Haruo Suenaga 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 1006 Kadoma, Kadoma-shi, Fuchu Matsushita Electric Industrial Co., Ltd.

Claims (8)

[Claims] 1. A holding portion for mounting and holding an inverter printed circuit board is arranged in parallel with a cooling passage of a magnetron having a radiation fin, and is integrally molded with the holding portion below the cooling passage to form a substantially L-shape in an orifice. A high-frequency heating device comprising a fan guide having an axial fan, and at least one control plate integrally formed with the fan guide at the orifice corresponding to the extension of the cooling passage. 2. A holding portion for mounting and holding an inverter printed circuit board is arranged in parallel with a cooling passage of a magnetron having a radiation fin, and the holding portion is integrally formed with the holding portion below the cooling passage so as to form a substantially L-shape in an orifice. A high-frequency heating device comprising a fan guide having an axial fan, and a control plate integrally formed with the fan guide at the orifice on the end face extension of the cooling passage facing the mounting portion of the magnetron. 3. A holding portion for mounting and holding an inverter printed circuit board is arranged in parallel with a cooling passage of a magnetron having a radiation fin, and the holding portion is integrally molded with the holding portion below the cooling passage so as to be substantially L-shaped in an orifice. A high-frequency heating device in which a fan guide having an axial-flow fan is provided, and a partition plate that crosses the orifice is provided between the fan guide and the cooling passage. 4. The high frequency heating device according to claim 3, wherein the height of the orifice portion of the partition plate is higher than that of the mounting portion. 5. A heat insulating plate is provided in parallel with the side plate in a machine chamber composed of a heating chamber, a machine room, etc., and a side plate and a back plate of the heating chamber, an operation section and a body cover. An air inlet is provided in the plurality of small holes and the heat insulating plate, the heating chamber and the machine room are communicated with each other by a heat insulating plate, and the position of the air inlet is arranged in a substantially L-shaped space surface to the air inlet. 5. A control plate having an opening for communication is provided.
The high-frequency heating device according to any one of items 1. 6. A heat-insulating plate is provided in parallel with the side plate in a machine chamber composed of a heating chamber, a machine chamber and the like, and a side plate and a back plate of the heating chamber, an operating section and a body cover. An air inlet is provided in the plurality of small holes and the heat insulating plate, the heating chamber and the machine chamber are connected by a heat insulating plate, the position of the air inlet is arranged in a substantially L-shaped space surface, and a part of the orifice is formed. 5. An inlet or a notched inlet portion is provided, and an air intake guide for guiding the inlet portion to the air inlet is provided on the outer circumference of the orifice, and the air inlet guide is provided to the air inlet. High frequency heating device. 7. The high frequency heating apparatus according to claim 5, wherein a guide plate is provided in a gap between the heat insulating plate and the holding portion. 8. The high-frequency heating device according to claim 5, wherein the air intake is opposed to the blowout flow of the axial fan.