JPS60264080A - High frequency heater with heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to improvements in the cooling structure and heating performance of a high-frequency heating device equipped with a heating device having heating means such as an electric heater or a gas burner.

Structure of conventional example and its problems For example, in the conventional high-frequency heating device 1 with a heater as shown in FIG. 1.2.3, the object to be heated is stored in the heating chamber 2.
A door 3 is provided at the front of the vessel. At this time, if the object to be heated is heated by high frequency, the high frequency oscillator 4
, a high-voltage transformer 6 , a high-voltage capacitor 6 , etc., generate a high frequency wave, guide it into the heating chamber 2 through a waveguide 7, and irradiate the object to be heated to heat it. Further, a fan motor 8 of high temperature 1 is provided to cool power supply parts and structural parts such as the high frequency oscillator 4 during high frequency heating.

Next, when heating the object to be heated in an open or grilled manner, the electric heater 9 is energized to raise the temperature in the heating chamber 2 containing the object to be heated. Since the temperature inside the heating chamber 2 becomes high, a second fan fan 11 is provided to suppress the rise in temperature inside the component storage space 1o.

FIG. 1 shows the cooling structure during high-frequency heating. In order to improve cooling efficiency, the first fan motor 8 and the second fan motor 11 are rotated simultaneously, and the air intake provided in the outer shell of the vessel is Outside air is sucked in through the opening 12 for use in the high frequency oscillator 4, high voltage transformer 5, high voltage capacitor 6, and other particularly resin structural parts provided in the parts storage space 10 in the upper part of the heating chamber 2, as well as in the upper part of the door 3. After cooling the printed circuit board 14 and the like mounted with various electronic components arranged behind the operation panel 13 provided therein, the structure is such that the printed circuit board 14 and the like are discharged through the exhaust opening 16 to the outside of the device.

In addition, in order to improve the cooling efficiency of the fan motor within the parts storage space 10, a first air guide 18 having an orifice 17 with an appropriate clearance is provided on the outer periphery of the propeller fan 16. A second air guide 19 is used to guide the air after cooling the heating chamber 2 into the heating chamber 2.
is provided, and is guided into the heating chamber 2 from the heating chamber first opening 21 provided in the upper plate 20 of the heating chamber 2, and is exhausted from the heating chamber second opening 22 through the exhaust guide 23 to the outside of the heating chamber. be done.

During heating by the electric heater 9, the inside of the parts storage space 10 is cooled by the second fan motor 11. At this time, the shaded area shown in FIG. 2 indicates the area where negative pressure 7 is generated due to the rotation of the fan motor. show. On the other hand, as the temperature inside the heating chamber 2 increases, the hot air tends to flow out of the heating chamber 2 through the first opening 21 of the heating chamber 2 provided in the upper plate 20 of the heating chamber 2. As a result, a large amount of hot air flows out as shown in the figure, and the thermal efficiency is extremely poor. In other words, in order to raise the temperature inside heating chamber 2, heat is transferred to the second
Because of the suction caused by the fan motor 11, the temperature inside the heating chamber 2 does not rise easily. The temperature near the first opening 21 of the heating chamber does not rise and the temperature (heat) distribution is poor, resulting in uneven heating and variations in temperature control relative to the set temperature in the heating chamber 2. It was a fatal flaw. In addition to hot air, water vapor generated by objects to be heated, especially pudding, etc., is also sucked in by the fan motor and transferred to the high-pressure transformer 5. High pressure air conditioner/su6
．． High frequency oscillator 4. Since the water vapor is sprayed onto the printed circuit board 14, etc., if the water vapor that hits the power supply parts condenses and adheres to the high voltage parts in particular, insulation between the high voltage parts and the ground cannot be ensured, resulting in high voltage being applied to the device body, or the high voltage transformer 5. In this case, the microcomputer-2 is in a very dangerous situation such as smoke and fire caused by a layer short in the secondary coil.
4, the charging part of electronic components such as IC25, and the printed circuit board 1.
Dew condensation may occur on the patterns on the microcomputer 24, causing malfunctions due to short-circuit phenomena in the electronic circuits and runaway of the microcomputer 24, resulting in a very dangerous situation.

Purpose of the Invention The present invention solves the above-mentioned conventional drawbacks, and improves thermal efficiency without affecting temperature control and temperature (heat) distribution, and suppresses the temperature rise of high-voltage parts and electronic circuits while suppressing water vapor and The purpose is to create a structure that prevents insulation from deteriorating due to water vapor condensation and from creating a dangerous short-circuit condition.

Structure of the Invention In order to achieve the above object, the high-frequency heating device with a heating device of the present invention has a heating chamber for storing and heating the object to be heated, and is equipped with heating means such as a high-frequency heating and an electric heater, a gas burner, etc. It is equipped with at least two or more fan motors installed in the parts storage space, and the air volume of the other fan motors is smaller than that of the first fan motor, which is driven only during high-frequency heating. A first air guide having an orifice with a clearance of , the suction side of the fan motor, or
A third air guide is provided in the direction of the rotation axis of the axial fan on the intake and exhaust side and in the direction that regulates the intake or exhaust direction, and when heating with an electric heater, gas burner, etc., the fan motor When forcibly cooling various parts in the parts storage space and the outer shell of the container, the temperature control and temperature (heat) distribution in the heating chamber are not affected, and moreover, the hot air and water vapor inside the heating chamber are rapidly drawn in. Since the air is sprayed onto the parts to be cooled, it not only prevents the cooling capacity from decreasing, but also reduces the temperature in the heating chamber 2.
It is very slow to heat up, takes a long time to heat up, minimizes wasteful energy consumption, and prevents insulation deterioration of high-voltage parts due to water vapor and condensation, dangerous short-circuit conditions, and dangerous situations such as electronic parts and This has the effect of avoiding dangerous situations such as malfunctions in short-circuit conditions and runaway of the microcomputer.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

4 and 5, when the object to be heated is housed in the heating chamber 2 and the electric heater 9 is energized, a high voltage transformer 5.
The second fan motor 11 for cooling electrical components such as the high-voltage capacitor 6, various electronic components mounted on the printed circuit board 14, and other particularly resin structural components is a fan that is driven only when high-frequency heating is performed. The air volume is smaller than Motor 8. In other words, propeller fan 16
When using the same fan motor 11, lower the rotation speed of the second fan motor 11.

If the number of revolutions is determined, the outer diameter and other dimensions of the propeller fan used in the second fan motor 11 are reduced, or in other words, the driving capacity of the second fan motor 11 is reduced. Also, at this time, as shown in FIG. 6, a first air guide 18 is provided with an orifice 1 having dimensions that provide a substantially constant clearance l around the outer periphery of the propeller fan 16.
In this structure, a third air guide 26 is provided between the air intake opening 12 provided in the outer shell of the vessel body in the direction of the rotation axis of the propeller fan 16 and in a direction that restricts the air intake direction. Further, in FIG. 7, a fourth air guide 27 is provided between the first and second fan motors in the same direction as the third air guide on the side from which air is discharged by the fan motor than the first air guide 18. In particular, in this embodiment, when the high voltage transformer 5 and the first air guide 18 are close to each other, and the first air guide 18 and the third air guide 26 are made of ferromagnetic material, the high voltage In order to prevent magnetic vibration due to leakage magnetic flux of the transformer 5 or to prevent magnetic vibration of the fourth air guide 27, the fourth air guide 27 is made of a non-magnetic material so that the first air guide 18 and The structure is such that magnetic vibration of the third air guide 26 or the fourth air guide 27 is prevented. Also, inside heating chamber 2 or heating chamber 2
detects a temperature rise in the vicinity of the second fan motor 11.
The structure is equipped with a temperature switch 28 for driving.

The operation of the above configuration will be explained below.

When heating, hot air and water vapor in the heating chamber 2 flow through the opening 21 of the heating chamber cylinder 1 provided on the upper plate 20 of the heating chamber 2 and into the component storage space 1o via the second air guide 19.
It flows out by natural convection.

In addition, heat is radiated from each wall surface of the heating chamber 2, especially from the upper plate 20, etc.,
A high voltage transformer 5 arranged in the parts storage space 10,
In order to cool electrical components such as the high voltage capacitor 6, various electronic components mounted on the printed circuit board 14, and other particularly resin structural components, the second fan motor 11 is driven to forcibly cool them. , the second fan motor 11 has a propeller fan 16 of the same size and shape as the first fan motor 8 which rotates only during high frequency heating.
Since the propeller fan 16 is used at a low rotation speed, the discharge pressure of the wind is low, but the negative pressure generated by driving the propeller fan 16 also decreases as shown by the shaded area. Therefore, forced suction of hot air and water vapor within the heating chamber 2 is reduced. As shown in FIG. Since it is in a sealed state and isolated from the component storage space 1o, negative pressure is generated as shown in the shaded area. It is extremely rare for the hot air and water vapor in the heating chamber 2 to be forcibly drawn in by the drive of the fan motor 2.

1. The pressure generated by the high temperature inside the heating chamber 2 and the second fan motor 11 in the parts storage space 10.
The pressure generated by the drive of the second fan motor 11
By balancing the number of revolutions and the design of the intake opening 12, exhaust opening 16, etc. provided in the outer shell of the vessel, heat radiation due to natural convection from the part with the highest amount of heat radiation is also extremely reduced. things are possible. At this time, if the second fan motor 11 is made to have the same cooling capacity as, for example, the first fan motor 8 and the air flow is increased, the temperature during heating can be controlled by sending cooling air into the heating chamber 2. If the temperature (heat) distribution becomes very poor, or if the rotational speed of both is the same but the air flow is reduced, the cooling capacity of electrical components such as the high-frequency oscillator 4 and high-voltage transformer 5 during high-frequency heating will be extremely poor. Especially high frequency oscillator 4
Since the fan motor 8 is a component with a small heat capacity but a large amount of heat, it is impossible to increase the capacity of the first fan motor 8 and set a particularly high discharge pressure compared to the conventional method, and the high frequency output decreases significantly due to overheating and the reliability decreases. There is a risk of decreased performance or burnout.

Next, in FIGS. 7, 8, and 9, a fourth air guide 27 is provided to rectify the flow of cooling air generated by the drive of the fan motor, and in particular, the flow of cooling air generated by the drive of the fan motor is The cooling air of the second fan motor 11 flows into the heating chamber 2 when the cooling capacity in the parts storage space 1o increases, with the aim of preventing interference when rotating simultaneously and increasing the cooling efficiency of each part. In order to eliminate the magnetic vibration of the first air guide 18 etc. caused by the leakage magnetic flux of the high voltage transformer 5, the heating chamber 2 or heating A temperature switch 28 is provided to detect the temperature rise in the vicinity of the heating chamber 2, and this operation is activated when the temperature of the heating chamber 2 rises to a certain level, thereby driving the second fan motor 11. This is a delayed operation in which the second fan motor 11 continues to be driven as long as the temperature rise in the heating chamber 2 or the vicinity of the heating chamber 2 is high, and the temperature in the heating chamber 2 is kept higher than normal temperature. When starting up the heating chamber 2, the second fan motor ~11 rotates only when the heating chamber reaches a high temperature, depending on the temperature switch operation settings, so the amount of heat radiated from the wall of the heating chamber 2 is extremely small and can be started quickly. The temperature inside the heating chamber 2 can be increased. Further, even at the end of heating, it is possible to easily suppress the temperature rise in the component storage space 10 due to overshoot due to residual heat in the heating chamber 2. Also, at this time, when attempting to delay operation of the second fan motor 11 during heating by high-frequency heating and electric heater, if there is no third air guide 26 or fourth air guide, as described above in FIG. Heating chamber 2 driven by second fan motor 11
Due to the temperature rise due to the suction of hot air and water vapor inside the parts storage space 10 and the short-circuit condition of the cooling air inside the parts storage space 10, it is not only possible to suppress the temperature rise inside the parts storage space 10, but also to increase the adverse effects of water vapor and condensation of water vapor. is clear.

In this way, according to this embodiment, the second fan motor 11
When it rotates and cools the parts storage space 10, hot air and water vapor in the heating chamber 2 are forcibly sucked in, and it takes extra time for the temperature inside the chamber to rise when heated by the electric heater, and it also causes forced cooling. However, not only is it not possible to suppress the temperature rise in the parts storage space 10, but it is also possible to control the temperature to the set temperature, which is an important performance of the original heating device, and to perform cooling without adversely affecting the temperature (heat) distribution. The configuration includes ensuring insulation resistance between high-voltage components such as the high-frequency oscillator 4, high-voltage transformer 6, and high-voltage capacitor 6 due to water vapor or condensation of water vapor, and smoke generation 9 due to short-circuiting of the secondary coil of the high-voltage transformer 5 and ignition of the microcomputer. It is possible to avoid malfunctions due to short-circuit conditions such as live parts of electronic components such as -24 and IC25 or patterns on the printed circuit board 14, and extremely dangerous situations due to runaway of the microcomputer 24. Parts storage space 1, which is the original purpose of driving the fan motor 11
The cooling performance of the inside of the heating chamber 2 and the outer shell of the container body can be greatly improved, and the temperature inside the heating chamber 2 can be raised quickly, and magnetic vibrations due to leakage magnetic flux of the high voltage transformer 5 can be prevented.

Effects of the Invention As described above, according to the present invention, the following effects can be obtained.

(1) Forced cooling can keep the temperature rise in the parts storage space and the outer shell of the container low, without requiring additional time for the temperature in the heating chamber to rise. By downgrading the insulation type and heat resistance of parts, electronic parts, and other resin-manufactured parts in particular, the cost can be significantly reduced, making it possible to provide the products to users at low prices.

In addition, the temperature rise in the outer shell of the container is also low, so even if the user touches it, there is no danger of burns or a feeling of anxiety.

(2) Forced cooling causes cooling air to flow into the heating chamber, and conversely, the negative pressure generated by the drive of the fan motor sucks in hot air, which has a negative impact on temperature control and temperature (heat) distribution, which are important performances of heating equipment. This configuration does not significantly reduce the given cooling performance. In addition, it is possible to avoid the danger of deterioration of the insulation performance of high-voltage parts due to water vapor and condensation of water vapor, and to prevent malfunctions and runaway of the microcomputer due to short circuits of electronic parts and printed circuit boards.

(3) It is possible to prevent magnetic vibration due to leakage magnetic flux of the high voltage transformer, and to greatly improve the cooling capacity even during high frequency heating. This improvement will lead to significant reductions in size, weight, and cost.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing the cooling structure during high-frequency heating of a conventional high-frequency heating device with a heating device, Figure 2 is a cross-sectional view showing the cooling structure during heating by the electric heater in Figure 1, and Figure 3 is the 2 is a side sectional view of FIG. 2, FIG. 4 is a sectional view showing the generation of negative pressure in the cooling structure during heating by an electric heater of a high-frequency heating device with heating device, which is an embodiment of the present invention, and FIG. 5 is a sectional view of the side view of FIG. FIG. 4 is a side cross-sectional view, and FIG. 6 is a cross-sectional view showing another embodiment of the present invention, which has a third air guide. FIG. 7 is a cross-sectional view of another embodiment of the present invention, which has a fourth air guide and a heating chamber or a temperature detection means in the vicinity of the heating chamber; FIG. 8 is a cross-sectional view taken from the side of FIG. FIG. 9 is a sectional view showing the flow of cooling air during high-frequency heating in FIG. 7. 2... Heating chamber, 4... High frequency oscillator, 9
...Electric heater, 6...High voltage transformer, 6
...High voltage capacitor, 8...First fan motor, 11...Other fan motor (
2nd fan motor) 16... Axial fan (
propeller fan), 17... orifice, 18...
...First air guide, 19...Second air guide, 26...Third air guide, 27.
...Fourth air guide, 28... Means for detecting temperature (temperature switch, Jchi). Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 1 214. Figure 2 24. 5 '1.5 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8

Claims (3)

[Claims] (1) A heating chamber that stores and heats hot materials in a part of the vessel, heating means such as electric heaters and gas burners, a high-frequency oscillator, high-voltage transformer, and high-voltage capacitor. A high-frequency oscillation means such as a high-voltage diode, and at least two fan motors for cooling the high-frequency oscillation means and structural parts inside the container are provided, and the fan motors other than the first fan motor are driven only during high-frequency heating. ,
High frequency heating device with heating device with reduced air volume. (2) A first air guide that has an orifice with a certain clearance around the outer circumference of the axial fan, a second air guide that guides the air after cooling the high-frequency oscillator, etc. into the heating chamber; A third air guide or A high-frequency heating device with a heating device according to claim 1, which is provided with a fourth air guide. (3) It has a means for detecting a temperature rise in the heating chamber or the vicinity of the heating chamber, and after detecting it with this means, the fan motor is driven, and even after heating is completed, the driving of the fan motor is delayed. A high-frequency heating device with a heating device according to claim 1 or 2, which is configured to perform the following.