JPH01111142A - Electric part cooling structure of high-elequency heating device - Google Patents

Abstract

PURPOSE:To reduce a blasting noise by providing an air flow direction plate formed with an arcuate orifice only at a position along the peripheral end edge of a cooling fan and facing normally a high frequency generator. CONSTITUTION:When a cooling fan 2 is rotated and driven, external air is introduced into a main body 1 of the device through a suction port 4. A part of an air flow is introduced into the upper position of a magnetron 5. Since an air flow direction plate 20 acts as a partition, no short-circuiting occurs and the cooling fan 2 always sucks up fresh air from the external part to send the same. An air stream led out from an orifice 21 and normally oppose the magnetron 5, and there is no loss due to the orifice 21. Further, no short- circuiting occurs and the air led concentratedly to the magnetron 5 to effectively cool the magnetron 5. Further, it is possible to sent an air flow having a low air flow pressure because there is no orifice in a high-tension transformer 6, and an air flow appropriate for the exhaust air route to improve the cooling performance.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a cooling structure for electrical components such as a high-frequency generator, such as a magnetron, and a high-voltage transformer, in a high-frequency heating device, such as a microwave oven. Regarding improvements.

(Prior Art) In a microwave oven, which is a high-frequency heating device, a magnetron, which is a high-frequency generator, a high-voltage transformer, and many other electrical components are arranged.
Heat is generated due to the heating and cooking action, which is a high frequency generation action. If this heat generation is left unchecked, the temperature inside the device body will rise and the electrical components will be further heated, leading to accidents such as thermal damage. Therefore, it is necessary to provide a dedicated cooling fan to forcefully cool the electrical components by blowing air introduced from outside the device main body to the electrical components. In addition, rather than simply blowing air from a cooling fan, it is possible to improve cooling efficiency by placing a wind guide plate between the cooling fan and electrical components, but recently, orifices have been adopted to further increase this effect. A new cooling structure has been developed.

An example of this is a cooling structure for electrical components using an orifice, as disclosed in Japanese Patent Laid-Open No. 131495/1983. This is as shown in Fig. 7, where 1 is the main body of the device, 2 is a cooling fan fitted to the Oa rotating shaft of motor 3, 4 is an intake port, 5 is a magnetron which is a high frequency generator, and 6 is a magnetron that is a high frequency generator. It is a high voltage transformer, and these magnetrons5. An electrical component S is composed of a high voltage transformer 6 and the like. Then, the magnetron 5 is oscillated to heat the object to be heated in the heating chamber 8, and the motor 3 is energized to rotate the cooling fan 2. This cooling fan 2 introduces external air into the apparatus main body 1 through an intake port 4, and blows the air to electrical components S such as the magnetron 5 and high voltage transformer 6 to cool them. Note that a partition plate 9 is provided near the cooling fan 2. One end of the partition plate 9 is fixed to a portion above the air intake port 4 of the main body 1 of the device, bent horizontally from this fixed portion, and extended to a portion above the motor 3. It is then bent downward along this edge,
It faces the peripheral edge of the cooling fan 2.

In other words, this portion serves as the orifice 10.

The orifice 10 is also called a bell mouth,
It is as shown in FIG. That is, it has a notch in the horizontal direction that is approximately the same height as the center of the cooling fan 2, and is formed in a semicircular shape concentric with the center of the cooling fan 2. As shown in FIG. 7 again, high-pressure air is sent to the magnetron 5 by the orifice action of the partition plate 9, and since there is no orifice to the high-voltage transformer 6, low-pressure air is sent to each. The system aims to improve cooling performance by sending air that is suitable for the exhaust route.

However, the shape and dimensions of the magnetron 5 mentioned above.

Due to the arrangement structure of the intake port 4 and the motor 3, the cooling fan 2 cannot face the magnetron 5 in a correct manner, that is, directly facing the magnetron 5, and their positions are usually shifted from each other. Naturally, the orifice 10 is also out of position with the magnetron 5 and does not directly face it. For this reason, all of the wind blown out through the orifice 10 is not guided to the magnetron 5, and some of the wind is blown directly to the rear of the magnetron 5. There is room for improvement in the cooling structure for the magnetron 5. There are problems such as air blowing noise. Further, since the orifice 10 is formed in a semicircular shape, the flow of air is bent along the cooling fan 2 and is constricted, resulting in a loss.

(Problems to be Solved by the Invention) The present invention eliminates the incomplete cooling effect and generation of air blowing noise caused by the above-mentioned orifices not directly facing the high-frequency generator and being misaligned with each other. It is an object of the present invention to provide a cooling structure for electrical components of a high-frequency heating device, which can improve the cooling efficiency of electrical components such as a generator and reduce air blowing noise.

[Structure of the invention]

(Means for Solving the Problems) That is, the present invention disposes electrical components such as a high frequency generator and a high voltage transformer within the main body of the device, and blows air introduced from the outside to these electrical components. A high-frequency heating device equipped with a cooling fan for cooling, characterized in that a wind direction plate with an arcuate orifice formed along the circumferential edge of the cooling fan and only in a portion directly facing the high-frequency generator is provided. This is a cooling structure for electrical components.

(Function) By configuring in this way, it is possible to send cooling air in a concentrated manner to the high-frequency generator without loss due to the orifice, and the wind that has collided with the high-frequency generator is not sucked into the cooling fan again. to prevent short circuits.

(Example) Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIGS. 1 and 2 show a part of a microwave oven, which is a high-frequency heating device. Regarding the parts that make up this microwave oven,
Components that are the same as those previously explained in FIG. 7 are given the same numbers, and new explanations will be omitted. Note that 12 is a high-voltage capacitor, and the magnetron 5. It constitutes an electrical component S together with the high voltage transformer 6 and the like.

A wind direction plate 20 is provided above the motor 3 and the cooling fan 2. One end of the wind direction plate 20 is fixed to a portion above the intake port 4 of the main body 1 of the device, bent horizontally from this fixed portion, and extended to a portion above the motor 3. Then, it is bent downward along the extended edge and faces the peripheral edge of the cooling fan 20 . In other words, this portion serves as the orifice 21.

The orifice 21 is as shown in FIG.
It is formed in an arc shape with the center of the cooling fan 2 as a concentric circle only in a portion directly facing the magnetron 5, which is not shown by the chain double-dashed line in the figure. Therefore, one end of the orifice 21 coincides with the lower edge of the magnetron 5, and the other end is integrally provided with a horizontal piece 22 extending in the horizontal direction.

Then, as shown in FIGS. 1 and 2 again, when the motor 3 is energized and the cooling fan 2 is driven to rotate, external air is introduced into the apparatus main body 1 through the intake port 4.

A portion of the river is directed to the upper part of the magnetron 5. Since the wind direction plate 20 acts as a partition for the wind flowing through this part, so-called short circuits do not occur, and the cooling fan 2 always sucks in fresh air from the outside and blows the air. Further, due to the orifice action of the orifice 21, high-pressure air is sent to the magnetron 5 for efficient cooling. That is, since the orifice 21 directly faces the magnetron 5, the wind led out from the orifice 21 is concentrated and guided to the magnetron 5 without any loss due to the orifice 21 and without short circuits.

Therefore, the magnetron 5 can be effectively cooled. Further, since there is no orifice in the high-pressure transformer 6, low pressure air can be sent to the high-pressure transformer 6, and air suitable for each exhaust route can be sent to the high-pressure transformer 6, resulting in good cooling performance.

As shown in FIG. 4, when the angle α is defined by the vertical central axis of the cooling fan 2 and the point where it touches the horizontal piece 22, which is the other end of the orifice 21, the angle α and the noise of the product are measured. The results (data obtained when the background noise was 25 d in actual measurement) are shown in FIG. As is clear from the figure, in the case of the magnetron 5, α is 45
If the temperature exceeds 100°, the rate of increase in noise will become large (if it leaves the magnetron 5), and if it is below that, it will be small.

From this, as shown in FIG. 6, the wind direction plate 20 is equipped with a 1/4 circular orifice 21a that coincides with the vertical central axis of the cooling fan 4, where α is Oo.
Even if it is a, the desired effects such as a reduction in air blowing noise can be obtained.

〔Effect of the invention〕

As explained above, according to the present invention, with the simple construction of providing an orifice directly facing a high-frequency generator, it is possible to improve the cooling performance of electrical components, reduce air blowing noise, and reduce costs. This has the effect of contributing to

[Brief explanation of the drawing]

1 to 5 show one embodiment of the present invention, FIG. 1 is a partial perspective view of a microwave oven which is a high frequency heating device, and FIG.
The figure is a side view, Figure 3 is a front view of the orifice and cooling fan, Figure 4 is an explanatory diagram of the angle α in the state shown in Figure 3, Figure 5 is its noise characteristic diagram, and Figure 6 is a diagram of its noise characteristics. The figure is a front view of an orifice and a cooling fan showing another embodiment of the present invention, Figures 7 and 8 show a conventional example of the present invention, and Figure 7 is a partial perspective view of a microwave oven that is a high-frequency heating device. Figure 8 is a front view of the orifice and the cooling fan. 1... Device main body, 5... High frequency generator, 6... High voltage transformer, S... Electrical components, 2... Cooling. fan,
21... Orifice, 20... Wind direction plate. Applicant's representative Patent attorney Takehiko Suzue Figure 3 Figure 2 Figure 4 0c (Kutomo) Figure 5 Figure 7 Figure 6 Figure 8

Claims (1)

[Claims] In a device that has electrical components such as a high frequency generator and a high voltage transformer disposed inside the device body and is equipped with a cooling fan that cools the electrical components by blowing air introduced from the outside to these electrical components, the surrounding area of the cooling fan is A cooling structure for electrical components of a high frequency heating device, characterized in that a wind direction plate having an arcuate orifice formed along an edge and only in a portion directly facing the high frequency generator is provided.