CN110793071A

CN110793071A - Microwave oven heat radiation structure and microwave oven

Info

Publication number: CN110793071A
Application number: CN201810864138.4A
Authority: CN
Inventors: 谢川川; 赵涛; 张冀喆; 张辉; 陈金鑫
Original assignee: Midea Group Co Ltd; Guangdong Midea White Goods Technology Innovation Center Co Ltd
Current assignee: Midea Group Co Ltd; Guangdong Midea White Goods Technology Innovation Center Co Ltd
Priority date: 2018-08-01
Filing date: 2018-08-01
Publication date: 2020-02-14

Abstract

The invention relates to the technical field of microwave ovens and discloses a microwave oven heat dissipation structure and a microwave oven. The microwave oven heat dissipation structure comprises an electric control cavity, a first fan and a second fan, wherein the first fan and the second fan are arranged on the wall of the electric control cavity; and a side air guide plate positioned at the side part of the air outlet of the second fan is arranged in the electric control cavity, and the transformer mounting position and/or the capacitor mounting position in the electric control cavity are/is positioned on an air outlet path of the second fan. Two fans can adopt the fan that the diameter is less, with reduction total amount of wind and pneumatic noise, realize the silence effect, under the circumstances that total amount of wind reduces, the cooling airflow that first fan produced is through the water conservancy diversion in first wind channel in order to fully cool off the magnetron of the other end in first wind channel, the cooling airflow that the second fan produced then can cool off other emergence components and parts such as the transformer on its flow path, so that the inside components and parts of microwave oven can both reach the radiating effect who satisfies the requirement, very big promotion product quality and user experience.

Description

Microwave oven heat radiation structure and microwave oven

Technical Field

The invention relates to the technical field of microwave ovens, in particular to a microwave oven heat dissipation structure and a microwave oven.

Background

At present, a microwave oven is used as a kitchen tool for heating and steaming and baking food conveniently and widely used by thousands of households due to the convenience of use, and becomes an indispensable kitchen appliance. Inside the microwave oven, the magnetron for generating microwave to heat and the transformer for supplying high voltage to the magnetron are the largest two heating elements, and the large amount of heat generated continuously will cause the temperature of these components to rise sharply, which affects the normal operation of the machine. The working temperature of the magnetron and the transformer is generally kept between 200 and 300 ℃. In addition, the operating temperature of other surrounding components is also significantly increased by the two main heating elements. Therefore, in order to ensure the normal operation of each component and reduce the influence of high temperature on the service life, the heat in the microwave oven needs to be discharged in time.

The existing product mainly uses an alternating current fan with a larger diameter. The fan is fixed on the back plate of the electric control chamber. In front of the air outlet of the fan, the upper half area is a magnetron, the lower half area is a transformer, and the magnetron and the transformer are directly blown by the fan to dissipate heat. Most of the air flow in the upper half area passes through the magnetron to take away heat, and a small part of the air flow flows upwards to cool components such as a filter plate above the fan, a power line branch and the like. The air flow in the lower half is mainly used for cooling the transformer and simultaneously cooling the capacitor below the fan and the components on the electronic panel at the far end.

In order to maintain the temperature of the electronic components in the microwave oven within the allowable temperature range during operation, the heat dissipation fan must provide sufficient cooling air volume to dissipate heat, and therefore, a high rotational speed (about 2400 to 2600rpm) is required. The existing fan has large diameter and high rotating speed, thereby bringing higher pneumatic noise. Therefore, the pneumatic noise of the microwave oven products on the market is over 56 dB. But with the improvement of living standard of people, the requirement on the comfort of household appliances is more and more strict, and higher noise can bring negative influence to the use of consumers.

Disclosure of Invention

The invention aims to provide a microwave oven heat dissipation structure, which can enable components inside a microwave oven to achieve the heat dissipation effect meeting the requirements under the condition of greatly reducing the pneumatic noise of the microwave oven, and greatly improve the product quality and the user experience.

In order to achieve the above object, the present invention provides a heat dissipation structure for a microwave oven, comprising an electric control cavity, a first fan, and a second fan, wherein the first fan and the second fan are disposed on a cavity wall of the electric control cavity; and a side air guide plate which is positioned at the side part of the air outlet of the second fan and guides the outlet air flow of the second fan to be conveyed forwards is arranged in the electric control cavity, wherein the transformer mounting position and/or the capacitor mounting position in the electric control cavity are/is positioned on the outlet air path of the second fan.

Through the technical scheme, because two fans are arranged, compared with an alternating current fan with a larger diameter in the prior art, the two fans can adopt fans with a smaller diameter, such as an axial flow fan, so that each fan does not need to operate at a high rotating speed, the total air volume can be reduced, the pneumatic noise of the microwave oven can be greatly reduced, the silencing effect is realized, meanwhile, under the condition that the total air volume is reduced, the side air guide plate arranged at the air outlet of the second fan guides the air outlet flow of the second fan to be conveyed forwards to pass through the transformer mounting position and/or the capacitor mounting position so as to cool the transformer and/or the capacitor mounted at each position, and the first fan can cool other components so that the components in the microwave oven can achieve the heat dissipation effect meeting the requirements, greatly improving the product quality and the user experience.

Further, when the transformer mounting position and the capacitor mounting position are simultaneously arranged on the air outlet path of the second fan, the capacitor mounting position is located between the transformer mounting position and the air outlet of the second fan.

Still further, the heat dissipation structure of the microwave oven further comprises a transformer installed on the installation position of the transformer and a capacitor installed on the installation position of the capacitor, wherein the transformer, the capacitor and the air outlet of the second fan are arranged at intervals, the height of the transformer is higher than that of the capacitor, so that a part of air flow sent by the second fan flows forwards along the upper surface of the capacitor, and can be deflected downwards after being blocked by the transformer to flow back from the lower surface of the capacitor to return to the air outlet of the second fan so as to form a surrounding air flow around the capacitor.

In addition, two side parts of the air outlet of the second fan are respectively provided with the side air guide plates, and a straight channel is formed between the two side air guide plates.

In addition, the microwave oven heat dissipation structure further comprises a first air channel, wherein one end of the first air channel is connected with an air outlet of the first fan, and the other end of the first air channel extends to a magnetron mounting position in the electric control cavity.

Furthermore, the microwave oven heat dissipation structure further comprises a second air channel extending towards the installation position of the filtering plate in the electric control cavity, and the second air channel is communicated with the air outlet of the first fan.

Furthermore, the microwave oven heat dissipation structure comprises a third air duct extending towards the installation position of the power line branching piece in the electric control cavity, and the third air duct is communicated with the air outlet of the first fan.

Furthermore, the lower wall, the left wall and the right wall of one end of the first air duct are respectively butted with the lower edge, the left edge and the right edge of the air outlet of the first fan, and the upper wall of one end of the first air duct is lower than the upper edge of the air outlet of the first fan, so that a part of the air outlet of the first fan leaks out; and a guide plate extending towards the front of the first fan air outlet is arranged on the upper edge to form the second air channel.

Furthermore, the guide plate is an arc-shaped plate, and the concave surface of the arc-shaped plate faces the upper wall.

Further, the baffle is disposed on a portion of the upper edge; the position department that is close to another part of upper edge of upper wall is provided with vertical water conservancy diversion front bezel and the vertical water conservancy diversion curb plate of connection, wherein, vertical water conservancy diversion front bezel is located the place ahead of first fan air outlet, vertical water conservancy diversion curb plate is located the side of first fan air outlet, and vertical water conservancy diversion front bezel and vertical water conservancy diversion curb plate form the third wind channel.

In addition, in the direction from one end to the other end of the first air duct, the distance between the upper wall and the lower wall of the first air duct gradually increases, and the distance between the left wall and the right wall of the first air duct gradually decreases.

Further, the end of the first air duct facing the magnetron mounting position further comprises an equal-diameter extending air duct section.

In addition, the first fan and the second fan are arranged up and down and disposed on a fan bracket in a height direction of the microwave oven, and the fan bracket is detachably connected to a rear cavity wall of the electric control cavity.

Finally, the present invention provides a microwave oven comprising the microwave oven heat dissipation structure as set forth in any of the above. Like this, as above, this microwave oven is under the condition that reduces aerodynamic noise by a wide margin, and the inside components and parts of microwave oven can reach the radiating effect who satisfies the requirement, very big promotion microwave oven's quality and user experience.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

fig. 1 is a partial perspective view illustrating a heat dissipation structure of a microwave oven according to an embodiment of the present invention;

FIG. 2 is a side view of the heat dissipating structure of the microwave oven shown in FIG. 1;

fig. 3 is a schematic top view of the heat dissipating structure of the microwave oven shown in fig. 1.

Description of the reference numerals

1-an electric control cavity, 2-a first fan, 3-a second fan, 4-a first air channel, 5-a second air channel, 6-a third air channel, 7-an upper wall, 8-an upper edge, 9-a guide plate, 10-a vertical guide front plate, 11-a vertical guide side plate, 12-a magnetron, 13-a filter plate, 14-a power line fork piece, 15-a transformer, 16-a capacitor and 17-a side guide plate.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

Referring to the structure shown in fig. 1 and fig. 2, the heat dissipation structure of a microwave oven provided by the present invention comprises an electronic control cavity 1, a first fan 2, and a second fan 3, wherein corresponding components required for the operation of the microwave oven can be arranged in the electronic control cavity 1, and the first fan 2 and the second fan 3 are arranged on the cavity wall of the electronic control cavity 1; a side air guide plate 17 is arranged in the electric control cavity 1 and is positioned at the side part of the air outlet of the second fan 3 to guide the outlet air flow of the second fan 3 to be conveyed forwards, wherein the transformer mounting position and/or the capacitor mounting position in the electric control cavity 1 are/is positioned on the outlet air path of the second fan 3.

In the technical scheme, because two fans are arranged, compared with an ac fan with a larger diameter in the prior art, the two fans can adopt fans with a smaller diameter, such as axial flow fans, so that each fan does not need to operate at a very high rotation speed, the total air volume can be reduced, the pneumatic noise of the microwave oven can be greatly reduced, the silencing effect is realized, meanwhile, under the condition that the total air volume is reduced, the side air deflector 17 arranged at the air outlet of the second fan 3 can prevent the air flow of the second fan 3 from leaking from the side and guide the air flow, so that the air flow is more gathered and conveyed to the front through the transformer installation position and/or the capacitor installation position to cool the transformer and/or the capacitor installed at each position, and the first fan 2 can cool other components, so that the components in the microwave oven can achieve the heat dissipation effect meeting the requirements, and the product quality and the user experience are greatly improved.

Of course, the transformer installation position and the capacitor installation position may be selected according to actual requirements, for example, in an embodiment, as shown in fig. 2, when the transformer installation position and the capacitor installation position are simultaneously disposed on the air outlet path of the second fan 3, the capacitor installation position is located between the transformer installation position and the air outlet of the second fan 3. In this way, since the heat generation amount of the capacitor is usually smaller than that of the transformer, the temperature rise of the cooling air is almost small after the capacitor is cooled by the cooling air delivered by the second fan 3, and therefore the transformer can be effectively cooled.

Further, in one embodiment, the heat dissipating structure of the microwave oven of the present invention may not include the transformer 15 and the capacitor 16, and the transformer 15 and the capacitor 16 may be installed at their respective positions when the microwave oven is assembled; or, in another embodiment, the heat dissipation structure of the microwave oven of the present invention includes a transformer 15 and a capacitor 16, as shown in fig. 2, the heat dissipation structure of the microwave oven further includes the transformer 15 mounted on the transformer mounting position and the capacitor 16 mounted on the capacitor mounting position, wherein the transformer 15, the capacitor 16 and the air outlet of the second fan 3 are arranged at intervals, and the height of the transformer 15 is higher than the height of the capacitor 16, so that a part of the air flow sent by the second fan 3 flows forward along the upper surface of the capacitor 16, and can be deflected downward after being blocked by the transformer 15 to flow back from the lower surface of the capacitor 16 to return to the air outlet of the second fan 3 to form a circulating air flow around the capacitor 16. In this way, the second fan 3 can continuously supply new cooling air, and a part of the cooling air forms a surrounding air flow around the capacitor 16 to take away the heat generated by the capacitor 16 as a whole.

In addition, of course, the arrangement of the side wind guide plate 17 may be determined according to actual requirements, for example, when a filter plate of a microwave oven is installed on a side wall of the electric control chamber 1, the side wind guide plate 17 may be arranged only at a position of the other side wall opposite to the filter plate due to the blocking of the filter plate, and of course, the end of the side wind guide plate 17 facing the second fan 3 is connected to a side edge of the second fan 3.

Or, when the filter plate is installed on the outer surface of the lower wall of the first air duct 4, or installed above the first air duct 4, the side air guide plates 17 may be respectively disposed on two opposite sides, the end of each side air guide plate 17 facing the second fan 3 is connected to the side edge of the second fan 3, that is, the side air guide plates 17 are respectively disposed on two side portions of the air outlet of the second fan 3, and a straight channel is formed between the two side air guide plates 17. Thus, as shown in fig. 2, the transformer 15 is located at the outlet of the flat passage, and the capacitor may be located at the lower portion of the flat passage, so that the cooling wind of the second fan 3 directly blows over the capacitor for precise cooling, while cooling the transformer 15 at the outlet.

In addition, in order to improve accurate and efficient cooling of the magnetron of the microwave oven, preferably, as shown in fig. 1 and 2, the heat dissipation structure of the microwave oven further includes a first air duct 4, wherein one end of the first air duct 4 is connected to the air outlet of the first fan 2, and the other end of the first air duct 4 extends to the magnetron mounting position in the electronic control cavity 1.

Like this, under the circumstances that the total amount of wind reduces, the cooling air current that first fan 2 produced through the water conservancy diversion in first wind channel 4 in order to fully cool off magnetron 12 at the other end in first wind channel 4, and the cooling air current that second fan 3 produced then can cool off other emergence components and parts on its flow path such as transformer 15 and electric capacity 16 as shown in fig. 2 to make the inside components and parts of microwave oven can both reach the radiating effect who satisfies the requirement, very big promotion product quality and user experience.

Of course, in the heat dissipation structure of the microwave oven of the present invention, the filter plate and the power line branching member in the microwave oven may also be cooled by the wind of the first fan or the second fan, for example, the filter plate and the power line branching member may be located in the first air duct, or may be located on the cooling wind flow path of the second fan, or the power line branching member may be located at the air inlet position of the first fan or the second fan, so as to be cooled by the wind flow sucked by the first fan or the second fan.

Or, in another embodiment, the heat dissipation structure of the microwave oven further includes a second air duct 5 extending toward the installation position of the filter plate in the electronic control cavity 1, and the second air duct 5 is communicated with the air outlet of the first fan 2, so that a part of the cooling air discharged by the first fan 2 can cool the filter plate at the installation position of the filter plate under the guidance of the second air duct 5.

The air outlet intercommunication of second wind channel 5 and first fan 2 can be realized through multiple structure, for example in a structure, the one end in second wind channel 5 can be connected on the wall in first wind channel 4, and the other end extends towards the filter plate mounted position. Or in another structure form, one end of the second air duct 5 is directly opposite to the air outlet of the first fan, and the other end extends towards the installation position of the filter plate.

Further, the heat dissipation structure of the microwave oven includes a third air duct 6 extending toward the installation position of the power line fork in the electronic control cavity 1, and the third air duct 6 is communicated with the air outlet of the first fan 2, so that a part of the cooling air discharged by the first fan 2 can cool the power line fork at the installation position of the power line fork under the guide of the third air duct 6.

The third air duct 6 can communicate with the air outlet of the first fan 2 through various structures, for example, in one structure, one end of the third air duct 6 can be connected to the wall of the first air duct 4, and the other end extends toward the installation position of the filter plate. Or in another structure form, one end of the third air duct 6 is directly opposite to the air outlet of the first fan, and the other end extends towards the installation position of the filter plate.

For example, in an embodiment, as shown in fig. 1, 2 and 3, in the height direction of the graphical interface of fig. 2 and 3, a lower wall (height direction of fig. 2), a left wall and a right wall (height direction of fig. 3) of one end of the first air duct 4 are respectively butted against a lower edge, a left edge and a right edge of the air outlet of the first fan 2, and an upper wall 7 of one end of the first air duct 4 is lower than an upper edge 8 of the air outlet of the first fan 2, so that a part of the air outlet leaks out; the guide plate 9 that sets up the place ahead extension towards the air outlet of first fan 2 on the top edge 8 is in order to form second wind channel 5, like this, filter plate 13 can be located the route in second wind channel 5, the cooling air that spills from the air outlet of first fan 2 partially flows out cools off the filter plate after guide plate 9 water conservancy diversion, of course, as shown in fig. 2, filter plate 13 can set up on the upper wall of first wind channel 4, or filter plate 13 fixed mounting is on the side chamber wall of electric control chamber and is located the top of the upper wall of first wind channel 4.

Of course, the deflector 9 may have any suitable shape as long as it can guide a part of the wind flow toward the front of the outlet of the first fan 2, for example, in one form, the deflector 9 may include an inclined plate connected to the upper edge 8 and inclined upward and a straight plate connected to the upper portion of the inclined plate and extending straight forward;

alternatively, as shown in fig. 1 and 2, the baffle 9 is an arc-shaped plate, and the concave surface of the arc-shaped plate faces the upper wall 7. Therefore, the inner arc concave surface of the arc plate is easier to guide the wind flow stably, and the loss of the wind flow is reduced.

Of course, the third air duct 6 may be formed by utilizing the feature that the upper wall 7 of one end of the first air duct 4 is lower than the upper edge 8 of the air outlet of the first fan 2, as shown in fig. 1 and 2, the baffle plate 9 is provided on a part of the upper edge 8, that is, the baffle plate 9 is not provided on the other part of the upper edge 8; in this way, a vertical flow guide front plate 10 and a vertical flow guide side plate 11 which are connected are arranged at the position of the other part of the upper wall 7 close to the upper edge 8, wherein the vertical flow guide front plate 10 is positioned in front of the air outlet, the vertical flow guide side plate 11 is positioned at the side of the air outlet, and the vertical flow guide front plate 10 and the vertical flow guide side plate 11 form a third air duct 6. Like this, the partly of the cooling air that leaks the part outflow from the air outlet of first fan 2 cools off the filter plate after guide plate 9 water conservancy diversion, and another part then flows upwards under the guide effect of vertical water conservancy diversion front bezel 10 and vertical water conservancy diversion curb plate 11 in order to cool off the power cord branching piece 14 of top, and at this moment, power cord branching piece 14 sets up in the top of electric control chamber 1.

Of course, the distance of the upper wall 7 of one end of the first air duct 4 lower than the upper edge 8 of the air outlet of the first fan 2 may be set as appropriate, for example, the distance of the upper wall 7 lower than the upper edge 8 is 15-25 mm. More preferably 20 mm.

Further, in order to enhance the cooling of the magnetron 12, it is preferable that, as shown in fig. 1 to 3, in a direction from one end to the other end of the first air passage, a distance between the upper wall and the lower wall of the first air passage 4 is gradually enlarged to enlarge a cooling area, and a distance between the left wall and the right wall of the first air passage 4 is gradually reduced to make the air flow more convergent. In this way, the gas flow can be more focused for delivery to the magnetron 12 for more adequate cooling.

Further, in order to facilitate the cooling wind supplied by the first wind tunnel 4 to cool the magnetron 12 smoothly, the end of the first wind tunnel 4 facing the magnetron mounting position preferably further includes a constant diameter extending wind tunnel section. Therefore, the conveyed cooling air can be smoothly and uniformly blown to the magnetron for more comprehensive cooling through the rectification of the equal-diameter extending air duct section.

Of course, the equal-diameter extending air duct section may be made of a heat-resistant material such as a metal material to be capable of abutting against the magnetron, or the equal-diameter extending air duct section may be made of a material with general heat resistance such as a hard plastic, and at this time, the front end of the equal-diameter extending air duct section needs to keep a proper distance from the magnetron to prevent the magnetron from softening the front end of the equal-diameter extending air duct section at a high temperature.

In addition, the specific installation positions of the first fan 2 and the second fan 3 may be selected according to actual requirements, for example, the first fan 2 and the second fan 3 may be separately installed to be located on different side walls of the electronic control chamber, or, as shown in fig. 1 and 2, the first fan 2 and the second fan 3 are arranged and disposed on a fan bracket in the height direction of the microwave oven for easy installation, and the fan bracket is detachably connected to the rear chamber wall of the electronic control chamber 1. Due to the fan bracket, the wall of the first air duct 4 can also be detachably connected to the fan bracket, so that the corresponding first air duct 4 can be replaced according to microwave ovens with different specifications.

Because first fan 2 and second fan 3 arrange from top to bottom to transformer mounted position and electric capacity mounted position are located the defeated wind route of second fan 3, such arrangement not only is convenient for transformer and electric capacity so that heavier components and parts use the diapire in automatically controlled chamber as the support, can also make full use of second fan 3 to cool off, also can install two fans concentratedly on the back lateral wall in automatically controlled chamber.

Finally, the present invention provides a microwave oven comprising the microwave oven heat dissipation structure as set forth in any of the above. For example, in the case of including the first air duct 4, the other end of the first air duct 4 extends to the magnetron 12, and other components in the microwave oven such as the transformer 15 and the capacitor 16 may be located on the cooling path of the second fan 3. Like this, as above, this microwave oven is reducing the condition of aerodynamic noise by a wide margin under, and the inside components and parts of microwave oven can reach the radiating effect who satisfies the requirement, very big promotion microwave oven's quality and user experience.

The preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications can be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. The invention is not described in detail in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.

Claims

1. A heat radiation structure of a microwave oven is characterized by comprising an electric control cavity (1), a first fan (2) and a second fan (3), wherein the first fan (2) and the second fan (3) are arranged on the cavity wall of the electric control cavity (1);

and a side air guide plate (17) which is positioned at the side part of the air outlet of the second fan (3) and guides the outlet air flow of the second fan (3) to be conveyed forwards is arranged in the electric control cavity (1), wherein the transformer mounting position and/or the capacitor mounting position in the electric control cavity (1) are/is positioned on the outlet air path of the second fan (3).

2. The heat dissipating structure of a microwave oven as claimed in claim 1, wherein when the transformer mounting position and the capacitor mounting position are provided on the air outlet path of the second fan (3) at the same time, the capacitor mounting position is located between the transformer mounting position and the air outlet of the second fan (3).

3. The heat dissipating structure of a microwave oven according to claim 2, further comprising a transformer (15) mounted on the transformer mounting position and a capacitor (16) mounted on the capacitor mounting position, wherein,

the transformer (15), the capacitor (16) and the air outlet of the second fan (3) are arranged at intervals, the height of the transformer (15) is higher than that of the capacitor (16), so that a part of the air flow sent by the second fan (3) flows forwards along the upper surface of the capacitor (16), and can be deflected downwards after being blocked by the transformer (15) to flow back from the lower surface of the capacitor (16) to return to the air outlet of the second fan (3) to form surrounding air flow around the capacitor (16).

4. The heat dissipating structure of a microwave oven as claimed in claim 1, wherein the side air guide plates (17) are respectively provided at both side portions of the outlet of the second fan (3), and a straight passage is formed between the side air guide plates (17).

5. The heat dissipating structure of the microwave oven according to any one of claims 1 to 4, further comprising a first air duct (4), wherein one end of the first air duct (4) is connected to the air outlet of the first fan (2), and the other end of the first air duct (4) extends to the magnetron mounting position in the electrically controlled cavity (1).

6. The heat dissipating structure of a microwave oven as claimed in claim 5, further comprising a second air duct (5) extending toward a mounting position of the filter plate in the cavity (1), wherein the second air duct (5) communicates with an air outlet of the first fan (2).

7. The heat dissipating structure of claim 6, wherein the heat dissipating structure of the microwave oven comprises a third air duct (6) extending toward a power line fork mounting position in the electrically controlled chamber (1), the third air duct (6) communicating with an air outlet of the first fan (2).

8. The heat dissipating structure of the microwave oven as claimed in claim 7, wherein a lower wall, a left wall and a right wall of one end of the first air duct (4) are butted against a lower edge, a left edge and a right edge of the outlet of the first fan (2), respectively, and an upper wall (7) of one end of the first air duct (4) is lower than an upper edge (8) of the outlet of the first fan (2) to allow a portion of the outlet of the first fan (2) to leak out;

and a guide plate (9) extending towards the front of the air outlet of the first fan (2) is arranged on the upper edge (8) to form the second air duct (5).

9. The heat dissipating structure of a microwave oven as claimed in claim 8, wherein the guide plate (9) is an arc-shaped plate, and the concave surface of the arc-shaped plate faces the upper wall (7).

10. The heat dissipating structure of a microwave oven as claimed in claim 8, wherein the baffle (9) is provided on a portion of the upper edge (8);

the position department that is close to of upper wall (7) another part of upper edge (8) is provided with vertical water conservancy diversion front bezel (10) and vertical water conservancy diversion curb plate (11) of connection, wherein, vertical water conservancy diversion front bezel (10) are located the place ahead of first fan (2) air outlet, vertical water conservancy diversion curb plate (11) are located the side of first fan (2) air outlet, and vertical water conservancy diversion front bezel (10) and vertical water conservancy diversion curb plate (11) form third wind channel (6).

11. The heat dissipating structure of a microwave oven as claimed in claim 5, wherein a distance between the upper and lower walls of the first duct (4) is gradually increased and a distance between the left and right walls of the first duct (4) is gradually decreased in a direction from one end to the other end of the first duct.

12. The heat dissipating structure of a microwave oven as claimed in claim 11, wherein the end of the first air duct (4) facing the magnetron mounting position further comprises a constant diameter extended air duct section.

13. The heat dissipating structure of a microwave oven as claimed in claim 1, wherein the first fan (2) and the second fan (3) are arranged up and down in a height direction of the microwave oven and are provided on a fan bracket detachably connected to a rear cavity wall of the electric control cavity (1).

14. A microwave oven, characterized in that the microwave oven comprises the heat dissipation structure of the microwave oven as claimed in any one of claims 1 to 13.