JP2008002756A - microwave - Google Patents

Abstract

Even when a microwave oven is placed in a narrow space and used in a state where the gap between the surrounding installation walls is small, electricity can be changed by changing the exhaust air passage without changing the basic structure of the main body. To provide a microwave oven that improves the cooling efficiency of parts and reduces the temperature rise.
The present invention has a magnetron cooling fan 20 and an electrical component cooling fan 28 at the lower part of the back of the main body, a heating chamber agitating fan 42 at the back of the heating box, and the inside of the heating chamber at the upper part of the back of the main body. In the microwave oven having the internal exhaust port 34 for exhausting from the main body to the outside, an exhaust guide 35 is provided at the internal exhaust port 34 to exhaust the exhaust toward the front side of the main body.
[Selection] Figure 4

Description

  The present invention relates to a microwave oven in which a mounted electric component is efficiently cooled by changing an exhaust ventilation path in a microwave oven installed in a narrow space such as a system kitchen.

  In a microwave oven, there is one described in, for example, Japanese Patent Application Laid-Open No. 2005-3319 (Patent Document 1) as an electric component cooled by blowing air.

JP 2005-3319 A

  When the microwave oven is used in a narrow space, the upper surface portion is designed to open a 200 mm space for installation, but there are no particular restrictions on the side surface portions and the back surface portions on both sides. For this reason, in order to configure the installation place as narrow as possible, the distance between the side surfaces on both sides and the back surface portion and the surrounding installation walls should be zero.

  On the other hand, in the case of a microwave oven, the temperature distribution is high on the top surface, and then on both sides and the back surface. Since the installation wall is usually made of many woods, the temperature needs to be relatively low. Therefore, the distance between the back surface and the installation wall is zero according to the temperature distribution, and the side walls on both sides are 10 It is installed with a gap of ~ 20mm.

  For this reason, since it becomes remarkably small with respect to the gap of about 50 mm in the related art, there is a problem that the ventilation resistance and the ventilation path are restricted, the cooling efficiency is lowered, and the temperature rise of the electrical component is increased.

  In other words, the cooling air was in the three directions of both sides, back and top, but the gap between both sides and the installation wall was reduced, the gap between the back and the installation wall was zero, and the ventilation resistance was greatly increased. As a result, the exhaust air does not diffuse from the installation space and stays on the upper surface of the rear and side surfaces. There was a problem that the temperature increased because of circulation.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a microwave oven that increases the cooling efficiency and reduces the temperature rise of electrical components by changing the exhaust air passage without changing the basic structure of the main body. And

  In order to solve the problems as described above, the present invention is configured to configure the exhaust guide so that the exhaust exhausted directly from the rear portion to the installation wall on the rear side is exhausted from the vertical to the front side by the exhaust guide, The heated air is discharged toward the front of the main body.

  For this reason, in Claim 1, it has the cooling fan for magnetrons and the cooling fan for electric parts in the lower part of the back of the main body, the heating fan stirring fan in the back of the heating cabinet, and the outside of the main body from the inside of the heating cabinet at the upper part of the back of the main unit. In the microwave oven having an internal exhaust port for exhausting air, an exhaust guide is provided at the internal exhaust port to exhaust the exhaust toward the front side of the main body.

  According to the second aspect, the angle θ between the tangent at the outlet of the exhaust guide and the horizontal plane is smaller than 90 degrees.

  According to a third aspect of the present invention, a protrusion is provided on the back cover that covers the back of the main body.

  According to a fourth aspect of the present invention, the exhaust guide is fixed by sharing a screw for fixing the back cover.

  According to the present invention, when the microwave oven is installed in a place where the installation space is reduced on the back surface and both side surfaces, it is heated by being configured to discharge from the vertical to the front side by the exhaust guide provided on the back surface. Since the air is discharged toward the front of the main body, it is possible to cool the electric parts of the microwave oven without a significant structural change.

  1 to 5 relate to an embodiment of the present invention, FIG. 1 is a perspective view of a product body, FIG. 2 is a bottom view with the outer frame and the like removed, and FIG. 3 is a perspective view from the back. 4 is an installation explanatory view seen from the side when the microwave oven is installed, and FIG. 5 is an installation explanatory view seen from the back when the microwave oven is installed.

  In the figure, there is a door 2 with a handle 1 on the front surface of the main body, and a transparent glass window 3 can be used to look inside. The door 2 can be opened horizontally by a hinge mechanism (not shown) with the lower part as a fulcrum by pulling the handle 1 forward.

  An operation panel 4 for setting a heating operation, a display device 5 as a display unit for displaying setting contents and an operation state, and a menu display 6 are arranged below the door 2. A display device 5 composed of a liquid crystal with a white background is arranged at a substantially central portion of the display portion, and menu displays 6 are arranged on both sides thereof.

  By separating the operation panel 4 serving as the operation unit and the display device 5 serving as the display unit and disposing the display unit on the glass window 3 side, the line of sight between the display unit and the user comes closer to the user, making it easy to use. Become a thing. Further, the operation time can be set quickly by rotating a dial 4a provided on the operation panel 4.

  In order to cool the operation panel 4, display device 5, and menu display 6 provided on the door 2, the air inlet 7 is opened at the bottom of the door 2, and the air outlet 8 is opened below the handle 1. ing. Since the door 2 is opened and closed between the lower body 9 and the door 2, a gap 10 is provided in a state where the door 2 is closed. Since the air inlet 7 is located at the lowermost part of the door 2 and the air outlet 8 is located almost at the uppermost part of the door 2, air circulation by natural convection is performed well. Further, since both the air inlet 7 and the air outlet 8 are located on the lower surface side of the door 2 and the handle 1, it is difficult to see directly from the user, so that the appearance is good.

  A plurality of ventilation openings 12 are provided on the side surface of the outer frame 11. Ventilation ports 12 are also provided on the side surface and the rear side opposite to those shown in FIG. 1, and as long as water does not enter directly from the upper surface, the position and the number of openings can be freely set, and the more the temperature can be reduced.

  In FIG. 2, the cooling fan 20 for electric components is arrange | positioned at the lower surface of the back part right side. Most of the cooling air generated by the cooling fan 20 for electric parts passes through the air passage of the ventilation A, cools the electric parts of the inverter board 22 on which the high voltage transformer 21 is mounted, and separates the ventilation boards B and C into the power supply board 23. Cool down.

  Ventilation C is exhausted from the side of the main body to the outside, and ventilation B passes through the power supply board 23 to reach the weight sensor 24b and is exhausted from the ventilation port 12 on the side of the main body. Since the position of the weight sensor 24b is far from the electric component cooling fan 20, the cooling efficiency is very poor. For this reason, the temperature tends to be higher than that of the other two weight sensors. Although the weight sensor 24a is under the power supply board 23, the distance from the electric component cooling fan 20 is also short, and since it is cooled by the ventilation B, the cooling efficiency is relatively good.

  Further, the cooling air flow D by the cooling fan 20 for electric parts is cooled by applying the cooling air to the weight sensor 24 c more efficiently by the ventilation guide 25.

A turntable motor 27 for driving a turntable (not shown) in the cabinet is disposed at substantially the center.

  The magnetron cooling fan 28 is arranged on the lower surface on the left side of the back surface opposite to the electric component cooling fan 20. Ventilation E by the magnetron cooling fan 28 cools the magnetron 29, and most of the air is exhausted to the outside through the ventilation port 12 from the side surface.

  On the back surface of the main body, a steel plate back cover 30 is fixed to the outer frame 11 with a plurality of screws 31. A suction port 32 for the electronic component cooling fan 20 and a suction port 33 for the magnetron cooling fan 28 are provided in the lower part. Since the suction ports 32 and 33 are provided in the lower part, the heated air moves upward by convection, so that air having a low temperature flows into the suction ports 32 and 33 provided below to improve cooling. it can.

  In addition, an internal exhaust port 34 is provided at the upper portion, and high temperature air containing water vapor generated from an object to be heated heated in the internal chamber is exhausted from the internal exhaust port 34. An exhaust guide 35 is fixed to the back cover 30 with a screw 36 at the interior exhaust port 34. Since the screw 36 extends the mounting seat 39 of the exhaust guide 35 and is shared with the mounting screw 31 of the back cover 30, the number of screws and the work process can be reduced.

A ventilation port 37 for cooling the hot air motor 84 that drives the internal stirring fan 42 used for internal stirring is provided at the center of the back cover 30. The inside stirring fan 42 is housed behind the inside back portion 43. Further, the back cover 30 is provided with a projection 38. Although the gap between the back cover 30 and the back surface installation wall 41 is zero, the projection 38 secures a space between the ventilation port 37 and the back surface installation wall 41, so a hot air motor that drives the internal stirring fan 42. 84 can be cooled. Further, since it is difficult to see the back side when installing the microwave oven, the positioning can be performed by pushing until the protrusion 38 hits the back surface installation wall 41, so that the installation becomes easy.

  Further, the exhaust in the chamber is exhausted forward rather than directly above by the exhaust guide 35, so that the heated air staying in the upper side is positively exhausted forward, and the side and lower sides are exhausted. Therefore, the temperature rise of the electrical components can be suppressed without increasing the temperature of the lower suction port 32 and the lower suction port 33.

  Most of the cooling air 51 to the lower suction port 32 and the suction port 33 is supplied through the gap between the side surface installation wall 50 and the outer frame 11. For this reason, the area of the plurality of ventilation holes 12 provided on the side surface of the outer frame 11 is heated because the upper part is larger than the lower part and most of the area is exhausted from the upper part having a larger area. The cooling air 51 is not exhausted from the lower side surface and circulated. Thereby, the temperature rise of an electrical component can be reduced.

Ventilation E by the magnetron cooling fan 28 cools the magnetron 29 and flows into the cabinet through the side surface ventilation path. The inflow ventilating air E is stirred by a stirring fan (not shown) provided in the warehouse and exhausted from the interior exhaust port 34. Since the magnetron 29 is cooled during the range operation, the magnetron cooling fan 28 operates continuously. However, since the temperature when it flows into the storage is about 70 ° C., the internal temperature does not decrease much. In this state, the object to be heated is heated and the generated water vapor is exhausted to the outside. When the oven is operating, it is necessary to keep the internal temperature as high as 300 ° C, so we want to evacuate without reducing the internal temperature as much as possible. I try not to. Since the magnetron is not operating during the oven operation, the temperature of the ventilation E is slightly higher than the outside air temperature.

  Next, the configuration of the exhaust guide 35 of this embodiment will be described with reference to FIG. Since the hot air having a temperature of 250 to 300 ° C. agitated in the chamber is exhausted to the exhaust guide 35, PBT or PPS containing glass having high heat resistance is molded and used. Further, during operation of the microwave oven, a large amount of steam is generated by heating the object to be heated in the warehouse, and is exhausted from the interior exhaust port 34 to the outside. A hole 60 for discharging condensed water is provided in the exhaust guide 35 so that the vapor does not condense and accumulate in the exhaust guide 35. Thereby, dew condensation water is prevented from entering from the inside exhaust port 34.

  The front end 61 of the exhaust guide 35 directs the exhaust toward the front side, so that the angle θ between the horizontal plane and the tangent 62 at the front end 61 is less than 90 degrees, so that the hot air 63 exhausted from the horizontal direction is exhausted from the exhaust guide 35. The air is exhausted in the tangential direction. Thereby, since the hot air 63 hits the upper surface installation wall 40 in a state having a velocity component in the front direction, it can be exhausted to the front side. The minimum value of θ is an angle larger than the contact angle when contacting the upper surface of the outer frame 11.

Next, a circuit block of the microwave oven according to the present embodiment will be described with reference to FIG. Power supply 70 is AC
Connected to a commercial power supply of 100V 50 / 60Hz. The power switch 71 is turned on to turn on the power. The power line noise and airwave noise are cut by the filter circuit 72, the power converted into the DC power by the rectifier circuit 73 is supplied to the inverter circuit 74, the frequency is converted, and the high voltage transformer 21 is connected to the primary side. Thus, a high voltage is generated on the secondary side and supplied to the magnetron 29 by the magnetron driving circuit 75 to operate the magnetron 29.

  A signal from the operation panel 4 is controlled by the microcomputer 77 via the display circuit 76. The weight sensor 24 is provided in a total of three places, two on the front side and one on the rear side in the storage, and thereby detects the weight of the heated object on the plate placed on the weight sensor 24. . Further, a temperature sensor 78 for detecting the temperature in the cabinet and a buzzer circuit 79 for notifying the end or abnormality are connected to the microcomputer 77.

  Various electrical components are connected to the microcomputer 77 via a drive circuit 80. The main electric components are the electric component cooling fan 20, the magnetron cooling fan 28, the upper heater 81 for heating the grill, the hot air heater 84 for generating hot air for heating the oven, and circulating and stirring the hot air in the chamber. A hot-air motor 83 for driving the internal stirring fan 42 to be performed, a boiler heater 85 for supplying steam to the internal space for steam heating, and the like are connected.

  Next, the operation timing of each electrical component will be described with reference to FIG. When the range is used, the magnetron 29 mainly operates. At this time, the electronic component cooling fan 20 and the magnetron cooling fan 28 are on. The hot air heater 84 is in an off state. When the oven is used, the hot air heater 84 is mainly turned on. At this time, the electronic component cooling fan 20 and the magnetron cooling fan 28 are also turned on. The magnetron 29 is in an off state. The inside temperature is the highest when the oven is used, and the maximum temperature is 250 to 300 ° C.

  In this embodiment, the exhaust guide 35 exhausts the exhaust from the interior toward the front side of the main body. Therefore, even if the gap between the back cover 30 and the rear installation wall 41 is zero, the exhaust is sucked into the cooling fan. There is no stagnation in the vicinity of the ports 32 and 33, and the electrical components can be efficiently cooled.

  FIG. 9 shows a sectional view of the exhaust guide 35 according to another embodiment of the present invention.

  When the microwave oven is used in an environment where the room temperature is low, when steam generated by cooking is exhausted from the interior, it comes into direct contact with the low temperature room temperature, and some of the water droplets become small droplets. Condensation occurs until the temperature rises. In addition, there is a problem that such moisture accumulates in the exhaust guide and flows out from the gap.

  In the exhaust guide 35, hot air at 250 to 300 ° C. in the refrigerator is agitated, and high-temperature air containing water vapor generated from the object to be heated is directly exhausted. Therefore, PBT or PPS containing glass with high heat resistance is molded. Are used. Further, since the inside of the exhaust guide 35 is attached to the outer frame 11 from the outside by screws 36, a gap 60 is formed. When the outside air temperature reaches 0 to 5 ° C., the hot air 63 having a high temperature and high humidity exhausted from the interior exhaust port 34 is condensed in the exhaust guide 35 having a low temperature to generate condensed water 65. For this reason, it is possible to prevent the outflow by collecting the dew condensation water 65 by lowering the back side bottom surface portion 67 from the bottom surface entrance side 66 so that the dew condensation water 65 does not directly flow out of the gap 60. Condensed water 65 is remarkably generated when the room temperature is 5 ° C. or lower, and the generated amount increases as the temperature decreases. Since the actual operating temperature range is generally 0 to 30 ° C., the range of 0 to 10 ° C. can be adapted to the amount of condensed water 65 produced. Condensed water 65 is generated mainly because the exhaust guide 35 becomes a condenser when the exhaust guide 35 comes into contact with hot air 63 of high temperature and high humidity. Since the exhaust guide 35 has a cooling capacity only for its own heat capacity, the temperature immediately rises and the condensed water 65 cannot be generated. After that, the temperature of the exhaust guide 35 becomes high, and the condensed water 65 naturally evaporates and decreases. And disappear. For this reason, in the present embodiment, the amount of condensed water 65 produced is 1 ml or less, so that this amount of condensed water 65 can be retained. The tip 61 of the exhaust guide 35 makes the exhaust air forward and the angle θ between the horizontal and the tangent 62 at the tip 61 is made smaller than 90 degrees, so that the hot air 63 exhausted from the horizontal direction hits the exhaust guide 35 in the tangential direction. By exhausting, the hot air 63 hits the upper surface installation wall 40 in a state having a velocity component in the front direction, so that it can be exhausted to the front side. The minimum value of θ is larger than the contact angle with the upper surface of the outer frame 11 and smaller than 90 degrees.

  According to the present embodiment, it is possible to provide a microwave oven in which the exhaust gas cooked in the refrigerator is condensed by the exhaust guide and does not flow out of the exhaust guide even when the room temperature is low.

  FIG. 10 is a cross-sectional view of the exhaust guide 35 according to another embodiment of the present invention. The exhaust guide 35 has a bottom surface portion entrance side 66 and a back surface bottom surface portion 67 that are horizontal, and a water retaining material 90 is attached to the bottom surface portion entrance side 66. The water retaining material 90 uses sponge, felt, or the like to facilitate water retention. Since the water retaining material 90 is attached to the bottom surface entrance side 66 to close the gap 60, the dew condensation water 65 can be more effectively prevented from flowing out.

FIG. 11 is a sectional view of the exhaust guide 35 according to still another embodiment of the present invention. The exhaust guide 35 has a bottom surface portion entrance side 66 and a back surface bottom surface portion 67 that are horizontal, and is provided with a recess 100 on the end surface of the bottom surface portion entrance side 66. Most of the condensed water 65 accumulates in the horizontal portion of the bottom surface portion, and a part flows out to the bottom surface entrance side 66 but is retained in the concave portion 100 so that it does not flow directly through the gap 60. This structure is suitable for structures with little condensed water.

  FIG. 12 is a cross-sectional view of the exhaust guide 35 according to still another embodiment of the present invention. The exhaust guide 35 is such that the bottom surface entrance side 66 and the back bottom surface portion 67 are horizontal, and a convex portion 110 and a slope 111 are provided inside the exhaust guide 35, and the hot air 63 is formed so that the slope 111 becomes the convex portion 110. Is set to the same direction to prevent resistance when the hot air 63 passes. Condensed water 65 is retained in the concave portion 112 formed by the convex portion 110 and the slope 111. This structure is suitable for structures with little condensed water.

  9, 10, 11, and 12 may be arbitrarily combined. The more combinations, the greater the water retention effect.

It is a perspective view of the product main body of the microwave oven of one Example of this invention. It is the bottom view seen in the state where the outer frame 11 etc. were removed of the microwave oven. It is the perspective view seen from the back of the microwave oven. It is installation explanatory drawing seen from the side surface when the same microwave oven is installed in the narrow space. It is installation explanatory drawing seen from the back surface when the same microwave oven is installed in the narrow space. It is sectional drawing of the exhaust guide 35 part of the microwave oven. It is a circuit block diagram of the microwave oven. It is explanatory drawing of the operation timing of each electric component of the microwave oven. It is sectional drawing of the exhaust guide 35 part in the other Example of the same microwave oven. It is sectional drawing of the exhaust guide 35 part in the other Example of the same microwave oven. It is sectional drawing of the exhaust guide 35 part in the other Example of the same microwave oven. It is sectional drawing of the exhaust guide 35 part in the other Example of the same microwave oven.

Explanation of symbols

2 ... Door, 4 ... Operation panel, 5 ... Display device, 6 ... Menu display, 7 ... Intake port, 8 ... Exhaust port, 12 ... Ventilation port, 20 ... Cooling fan for electrical parts, 28 ... Cooling fan for magnetron,
29 ... Magnetron, 30 ... Back cover, 31, 36 ... Screw, 32, 33 ... Suction port, 34 ... Exhaust port in chamber, 35 ... Exhaust guide, 38 ... Projection, 40 ... Upper surface installation wall, 41 ... Rear surface installation Wall, 42 ... Stirring fan in the cabinet, 62 ... Tangent.

Claims (8)

  There is a magnetron cooling fan and electrical component cooling fan at the bottom of the back of the main unit, a heating chamber agitation fan at the back of the heating chamber, and an exhaust port inside the chamber that exhausts from the inside of the heating chamber to the outside of the main unit. The microwave oven according to claim 1, wherein an exhaust guide is provided at the interior exhaust port, and the exhaust is exhausted toward the front side of the main body.   2. The microwave oven according to claim 1, wherein an angle [theta] between a tangent at the outlet of the exhaust guide and a horizontal plane is smaller than 90 degrees.   3. The microwave oven according to claim 1, wherein a protrusion is provided on the back cover that covers the back of the main body.   4. The microwave oven according to claim 1, wherein the exhaust guide is fixed by sharing a screw for fixing the back cover.   In a microwave oven with a magnetron cooling fan, an electrical component cooling fan at the bottom of the back, and a stirring fan at the back of the interior, and an interior exhaust at the top of the back, an exhaust guide is provided at the interior exhaust. A microwave oven provided with an exhaust guide that is provided and has a bottom surface on the back side that is lower than an entrance side of the bottom surface so that condensed water condensed inside the exhaust guide does not leak outside.   In a microwave oven with a magnetron cooling fan, electrical component cooling fan in the lower part of the rear part, and a stirring fan in the rear part of the interior, and an exhaust outlet in the upper part of the rear part, an exhaust guide is provided in the exhaust part of the interior. A microwave oven provided with a water retaining material for retaining condensed water inside the exhaust guide so that the condensed water condensed inside the exhaust guide does not leak outside.   In a microwave oven with a magnetron cooling fan, electrical component cooling fan in the lower part of the rear part, and a stirring fan in the rear part of the interior, and an exhaust outlet in the upper part of the rear part, an exhaust guide is provided in the exhaust part of the interior. A microwave oven characterized in that the entrance has a recessed side end surface so that the condensed water condensed inside the exhaust guide does not leak outside. In a microwave oven with a magnetron cooling fan, an electrical component cooling fan at the bottom of the back, and a stirring fan at the back of the interior, and an interior exhaust at the top of the back, an exhaust guide is provided at the interior exhaust. A microwave oven characterized in that it is provided with a convex portion on the inside so that the condensed water condensed inside the exhaust guide does not leak to the outside and is inclined to reduce resistance in the exhaust direction.

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