EP0468640A1 - Appareil de chauffage à haute fréquence - Google Patents

Appareil de chauffage à haute fréquence Download PDF

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Publication number
EP0468640A1
EP0468640A1 EP91305691A EP91305691A EP0468640A1 EP 0468640 A1 EP0468640 A1 EP 0468640A1 EP 91305691 A EP91305691 A EP 91305691A EP 91305691 A EP91305691 A EP 91305691A EP 0468640 A1 EP0468640 A1 EP 0468640A1
Authority
EP
European Patent Office
Prior art keywords
magnetron
machine compartment
duct
air
high voltage
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP91305691A
Other languages
German (de)
English (en)
Inventor
Yukio Nagoya Works K. K. Toshiba Suzuki
Minoru Nagoya Works K. K. Toshiba Takagi
Masaaki Nagoya Works K. K. Toshiba Ozaki
Atuhiko Nagoya Works K. K. Toshiba Ono
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toshiba Corp
Original Assignee
Toshiba Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toshiba Corp filed Critical Toshiba Corp
Publication of EP0468640A1 publication Critical patent/EP0468640A1/fr
Withdrawn legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/64—Heating using microwaves
    • H05B6/6426—Aspects relating to the exterior of the microwave heating apparatus, e.g. metal casing, power cord
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24C—DOMESTIC STOVES OR RANGES ; DETAILS OF DOMESTIC STOVES OR RANGES, OF GENERAL APPLICATION
    • F24C7/00—Stoves or ranges heated by electric energy
    • F24C7/02—Stoves or ranges heated by electric energy using microwaves
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/64—Heating using microwaves
    • H05B6/642—Cooling of the microwave components and related air circulation systems

Definitions

  • This invention relates to an improvement of the cooling construction of a machine compartment in a high frequency heating apparatus.
  • a machine compartment is provided at one side of a heating chamber so as to be adjacent thereto in high frequency heating apparatus such as microwave ovens.
  • a magnetron is provided in the machine compartment and a high voltage transformer is also provided over the magnetron in the machine compartment.
  • a cooling fan is provided behind the magnetron and high voltage transformer so that a cooling air delivered from the cooling fan is directed to both of the magnetron and the high voltage transformer, thereby cooling them.
  • the cooling air from the cooling fan needs to be dissipated so as to be directed to both the magnetron and the high voltage transformer, resulting in low cooling efficiency.
  • a so-called built-in type wherein the high frequency heating apparatus is built in a cabinet has recently found popular. Since an air intake efficiency to the machine compartment is lowered by the cabinet in the case of the built-in type, the cooling efficiency is further lowered.
  • a large-sized cooling fan needs to be employed to overcome this problem, which increases the production cost of the high frequency heating apparatus.
  • an object of the present invention is to provide a high frequency heating apparatus wherein both of the magnetron and the high voltage transformer provided in the machine compartment can be cooled efficiently and reasonably, thereby improving the cooling performance.
  • the present invention provides a high frequency heating apparatus comprising an outer casing, a heating chamber provided within the outer casing, a machine compartment provided adjacent the heating chamber within the outer casing, a magnetron provided in the machine compartment for radiating high frequency waves into the heating chamber so that a food contained in the heating chamber is heated, a high voltage transformer provided in the machine compartment for applying a high voltage to the magnetron, a partition member partitioning the interior of the machine compartment into a space where the magnetron is disposed and the other space where the high voltage transformer is disposed, the partition member having a ventilation opening, and a cooling fan provided at the ventilation opening of the partition member so that air in the space where the high transformer is disposed is taken in and then delivered into the space where the magnetron is disposed.
  • the high voltage transformer is cooled by air taken in by the cooling fan and the magnetron is cooled by the air delivered from the cooling fan. Accordingly, the high voltage transformer can efficiently be cooled by making effective use of the intake air of the cooling fan. Also, the magnetron can efficiently be cooled by having the air from the cooling fan concentrated onto it.
  • the partition member comprise a duct and the magnetron be enclosed by the duct.
  • An air guide action of the duct can cause the air delivered from the cooling fan to be further concentrated onto the magnetron, resulting in further improvement of the cooling efficiency.
  • the machine compartment have a bottom plate having one or a plurality of air inlets and a high voltage capacitor be provided so as to face a flow of air from each air inlet.
  • the high voltage capacitor can also be cooled by the intake air of the cooling fan efficiently.
  • the duct may have an open upper side and an open side so that the open upper side and the open side are closed by an upper side and a side of the machine compartment respectively, thereby forming a ventilation path.
  • a number of ventilation apertures may be formed in one side wall of the machine compartment so that air flowing along the duct is fed into the heating chamber through the ventilation apertures and an upper wall of the machine compartment may have escape apertures through which a part of the air flowing along the duct is caused to escape. Consequently, the heating chamber can be ventilated by feeding the air flowing along the duct into the heating chamber through the ventilation apertures formed in the side wall of the machine compartment.
  • the flow resistance of the air flowing along the duct can be reduced and an amount of air flowing along the duct can be increased, which can further improve the cooling performance.
  • the magnetron may have a terminal member connected to a secondary side of the high voltage transformer and the duct may have a hole through which the terminal member is externally exposed. Consequently, wiring from the high voltage transformer secondary side to the magnetron terminal member can be performed by viewing through the hole, which simplifying the wiring work.
  • An outer casing 1 of the high frequency heating apparatus has therein a heating chamber 2 (see FIG. 2) and a machine compartment 3 provided left and right respectively.
  • a high voltage transformer 5 is provided on a bottom wall 4 within the machine compartment 3 and a high voltage capacitor 6 is provided behind the transformer 5 within the machine compartment 3.
  • Air inlets 7 are formed in the bottom wall 4 so as to be positioned before and behind the high voltage transformer 5.
  • Legs 19 are mounted on the outer bottom wall 4 so as to provide below each air inlet 7 a space sufficient for the air intake.
  • the high voltage capacitor 6 is disposed so as to face a flow of air taken in through each air inlet 7.
  • a magnetron 9 is mounted on an upper plate 8 of the machine compartment 3 with an output antenna 9a directed upwards.
  • the magnetron 9 is driven by a high voltage at the transformer 5 secondary side to radiate high frequency waves from the output antenna 9a.
  • the high frequency waves delivered from the output antenna 9a are guided by a waveguide 10 mounted on the upper plate 8 into the heating chamber 2.
  • the magnetron 9 is enclosed by a duct 11 serving as a partition member partitioning the machine compartment 3 interior into two compartments.
  • the duct 11 is formed, for example, of a suitable plastic material so as to have an open upper side and an open side.
  • the duct 11 is secured by means of screws to a side wall 12 partitioning the outer casing interior into the heating chamber 2 and the machine compartment 3 and to the upper plate 8.
  • the open upper side and the open side of the duct 11 are closed by the side wall 12 and the upper plate 8 such that a ventilation path is formed together by the duct 11.
  • the duct 11 has a ventilation opening 13 formed in its rear portion.
  • a motor 15a of a cooling fan 15 is mounted by means of screws on a support flame 14 formed at the ventilation opening 13 so as to be directed upwards.
  • the machine compartment interior is thus partitioned by the duct 11 into air intake and outlet sides of the cooling fan 15 such that the high voltage transformer 5 is disposed in the air intake side and the magnetron 9 in the outlet side.
  • a number of ventilation apertures 16 are formed in the side wall 12 of the machine compartment 3 so as to correspond to outlet side of the duct 11. Air is fed into the heating chamber 2 through the ventilation apertures 16 during the high frequency heating to thereby ventilate the heating chamber 2.
  • a damper (not shown) is provided within the duct 11 for opening and closing the ventilation apertures 16. The damper is closed in an oven cooking mode wherein a heater (not shown) provided on the back of the heating chamber 2 is energized so that a heated air is fed into the heating chamber 2.
  • Escape apertures 17 are formed in the upper plate 8 of the machine compartment 3 so that a part of the outlet air flowing along the duct 11 is caused to escape through them. The air from the escape apertures 17 flows rearward along a space between the upper plate 8 and a ceiling 1 a of the outer casing 1 to be exhausted from an exhaust hole 18 formed in a rear plate 1 b of the outer casing 1.
  • the magnetron 9 is provided with a thermal switch 21 for detecting its overheating condition and a terminal member 22.
  • the thermal switch 21 and the terminal member 22 are exposed outward of the duct 11 through holes 23 and 24 (see FIG. 4) respectively.
  • the terminal member 22 is connected to the secondary side of the high voltage transformer 5.
  • the magnetron 9 is operated during the high frequency heating operation so that the high frequency waves are radiated into the heating chamber 2 and also, the cooling fan 15 is driven so that air is taken in through the air intake apertures 7.
  • the air thus taken in flows along the outer surfaces of the high voltage transformer 5, high voltage capacitor 6 and the like, thereby cooling them.
  • the intake air is caused by an air blowing action of the cooling fan 15 to flow along the outer periphery of the motor 15a, cooling it.
  • the intake air is then taken in through the ventilation opening 13 to be delivered into the duct 11.
  • the air delivered into the duct 11 flows forward along the magnetron 9, cooling it.
  • the air is fed into the heating chamber 2 through the ventilation apertures 16 after passing through the magnetron 9, thereby ventilating the heating chamber 2.
  • a part of the air passing through the magnetron 9 is caused to escape through the escape apertures 17 into the space between the upper plate 8 and the ceiling 1 a to be exhausted through the exhaust hole 18. Consequently, the flow resistance of the air flowing along the duct 11 is reduced, which increases an amount of air flowing along the duct 11 and accordingly, improves the cooling performance.
  • the machine compartment 3 interior is partitioned by the duct 11 into the intake and outlet sides of the cooling fan 15.
  • the high voltage transformer 5 is disposed at the intake side and the magnetron 9 at the outlet side in the machine compartment 3. Accordingly, the high voltage transformer 5 can efficiently be cooled by making effective use of the intake air and the magnetron 9 can efficiently be cooled by concentrating the outlet air delivered from the cooling fan 15 onto the magnetron 9, which can improve the cooling efficiency in the machine compartment 3. Therefore, even when the high frequency heating apparatus of the embodiment is used as the built-in type wherein the apparatus is enclosed in a cabinet (not shown), a sufficient cooling performance can be secured. Particularly, the cooling fan 15 need not be rendered large-sized and accordingly, the increase in the production cost can be prevented.
  • the duct 11 is employed as the partition member partitioning the machine compartment interior into the intake and outlet sides of the cooling fan 15 and the magnetron 9 is enclosed by the duct 11, the air guide action of the duct 11 can cause the outlet air delivered from the cooling fan 15 to be further concentrated onto the magnetron 9, resulting in further improvement of the cooling efficiency.
  • the high voltage capacitor 6 Since the high voltage capacitor 6 is disposed so as to face a flow of air taken in through each air inlet 7 formed in the bottom plate 4 of the machine compartment 3, the high voltage capacitor 6 can also be cooled by the intake air of the cooling fan 15 efficiently.
  • escape apertures 17 are formed in the upper plate 8 of the machine compartment 3, a part of air flowing along the duct 11 is allowed to escape through the escape apertures 17. Consequently, the flow resistance of the air flowing along the duct 11 can be reduced and an amount of air flowing along the duct 11 can be increased, which can further improve the cooling performance.
  • the duct 11 is provided with the hole 24 into which the terminal member 22 of the magnetron 9 is inserted so that it is externally exposed, the wiring from the high voltage transformer secondary side to the magnetron terminal member 22 can be performed by viewing through the hole 24, which simplifying the wiring work.
  • the cooling fan 15 is mounted on the duct 11 so as to be directed upwards in the foregoing embodiment, it may be mounted on the duct 11 so as to be directed toward the magnetron 9 and inclined forward. Further, the configuration of the duct 11 may be changed and the positions of the cooling fan 15 and the high voltage transformer 5 may be changed.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Constitution Of High-Frequency Heating (AREA)
  • Electric Ovens (AREA)
EP91305691A 1990-07-24 1991-06-24 Appareil de chauffage à haute fréquence Withdrawn EP0468640A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP195822/90 1990-07-24
JP2195822A JPH0482190A (ja) 1990-07-24 1990-07-24 電子レンジ

Publications (1)

Publication Number Publication Date
EP0468640A1 true EP0468640A1 (fr) 1992-01-29

Family

ID=16347578

Family Applications (1)

Application Number Title Priority Date Filing Date
EP91305691A Withdrawn EP0468640A1 (fr) 1990-07-24 1991-06-24 Appareil de chauffage à haute fréquence

Country Status (3)

Country Link
EP (1) EP0468640A1 (fr)
JP (1) JPH0482190A (fr)
KR (1) KR930002744A (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001049078A1 (fr) * 1999-12-27 2001-07-05 Lg Electronics Inc. Four a micro-ondes encastre

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2320440B2 (de) * 1973-04-21 1975-06-19 Robert Bosch Elektronik Gmbh, 1000 Berlin Und 7000 Stuttgart Gerät zur Erwärmung von Blut durch Mikrowellen
GB2056826A (en) * 1979-05-01 1981-03-18 Rinnai K Cooking apparatus
DE3521924A1 (de) * 1984-06-19 1986-01-30 Sharp Kk Mikrowellenherd
US4812617A (en) * 1979-03-06 1989-03-14 Sharp Kabushiki Kaisha Cooling system for cooling electrical parts for microwave oven

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2320440B2 (de) * 1973-04-21 1975-06-19 Robert Bosch Elektronik Gmbh, 1000 Berlin Und 7000 Stuttgart Gerät zur Erwärmung von Blut durch Mikrowellen
US4812617A (en) * 1979-03-06 1989-03-14 Sharp Kabushiki Kaisha Cooling system for cooling electrical parts for microwave oven
GB2056826A (en) * 1979-05-01 1981-03-18 Rinnai K Cooking apparatus
DE3521924A1 (de) * 1984-06-19 1986-01-30 Sharp Kk Mikrowellenherd

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001049078A1 (fr) * 1999-12-27 2001-07-05 Lg Electronics Inc. Four a micro-ondes encastre
US6528774B2 (en) 1999-12-27 2003-03-04 Lg Electronics Inc. Built-in microwave oven

Also Published As

Publication number Publication date
KR930002744A (ko) 1993-02-23
JPH0482190A (ja) 1992-03-16

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Effective date: 19920918

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Effective date: 19930129