CN100347485C

CN100347485C - Microwave oven with reduced electromagnetic noise

Info

Publication number: CN100347485C
Application number: CNB2004100785272A
Authority: CN
Inventors: 大平秀世
Original assignee: Toshiba Hokuto Electronics Corp
Current assignee: Toshiba Hokuto Electronics Corp
Priority date: 2003-09-10
Filing date: 2004-09-10
Publication date: 2007-11-07
Anticipated expiration: 2024-09-10
Also published as: DE602004001113T2; DE602004001113D1; JP2005085661A; EP1515590A1; JP3825430B2; CN1594986A; KR101023267B1; KR20050026874A; EP1515590B1

Abstract

A microwave oven includes a magnetron apparatus (14), a heat chamber (13), a chassis (11) and a cabinet (12). The magnetron apparatus (14) contains a magnetron tube (15) which generates an electromagnetic wave, and a metal member (16). The metal member (16) is electrically connected to the anode (15a) and encloses the magnetron tube (15). The heat chamber (13) is supplied with the electromagnetic wave. The heat chamber (13) is mounted on the chassis (11). The cabinet (12) constitutes a body (10) that covers the magnetron apparatus (14) and the heat chamber (13) in combination with the chassis (11). In the microwave oven, the metal member (16) and the cabinet (12) are electrically connected through an electrically conductive sponge (17). This microwave oven can suppress radiation noise.

Description

Micro-wave oven

Technical field

The micro-wave oven that the present invention relates to the culinary art of food and thawing etc. used.

Background technology

The Japan Patent spy opens that clear 63-110527 communique, spy are opened flat 08-007773 communique, the spy opens flat 09-320478 communique etc. and disclosed traditional micro-wave oven.Here, describe with reference to the example of the stereogram of seeing from the front face side of Figure 10 traditional micro-wave oven.The framework 100 of micro-wave oven is made of frame 101 and housing 102 etc.

Frame 101 is made of framework soleplate 101a and frame header board 101b, frame backboard 101c etc.Heating clamber 103 is configured on the framework soleplate 101a, and heating clamber is installed on the part of frame 101 with door 103a.Housing 102 is such as being bent to form コ word shape by 1 metallic plate, is made of upper wall portions 102a and side wall portion 102b, the 102c etc. that are positioned at about it.

The front face side of basket 100, with a door 103a residing side, the periphery in the frame end is provided with claw clinch (not shown) such as heating clamber, and in addition, the periphery in the end of housing 102 is provided with a plurality of claws (not shown).And the pawl carrier of frame 101 combines so that both are fixed with the claw mechanical type of housing 102.Meanwhile, the rear side of basket 100 is respectively equipped with screw hole on frame 101 and housing 102, both are screwed.

In addition, near configuration magnetron device 104 heating clamber 103.

Magnetron device 104 is by the magnetron (not shown) of high frequency source and be positioned at the outside of magnetron and form the formations such as filter cartridge 104c of the yoke 104b of the part of magnetic loop, the input part 104a that folding and unfolding has magnetron etc.

In addition, between heating clamber 103 and magnetron device 104, be provided with the waveguide pipe 105 that the electromagnetic wave to magnetron device 104 output transmits.

In the said structure, food etc. are configured in the heating clamber 103 of micro-wave oven.The electromagnetic wave that magnetron device 104 produces is supplied with heating clamber 103 via waveguide pipe 105, makes the food heating in the heating clamber 103.

Micro-wave oven is used as high-frequency agitation source with magnetron.Higher hamonic wave and radiation noise etc. except the basic wave corresponding with frequency of oscillation takes place, also take place in magnetron when action.In recent years, press for and prevent electromagnetic-wave leakage, suppress higher hamonic wave and radiation noise.

Traditional micro-wave oven such as the high frequency choke structure is set at efferent, in addition, is provided with filter cartridge at input part, and utilizes the function of shielding of basket part to wait to prevent electromagnetic leakage.

But the frame of the basket part of formation micro-wave oven is by welding and riveted joint etc. and heating clamber electrically conducting.The anode part electrically conducting of heating clamber and magnetron, usually, the anode part ground connection of magnetron.Therefore, frame becomes ground state, has good shielding character.

On the other hand, housing is that the front face side of basket is fixed on the frame by the mechanical type contact, and rear side is fixed on the frame with Screw.Housing and frame are considered appearance looks elegant etc., use the metallic plate after the application usually.Because of coating is insulating properties, so housing contacts many parts with frame in the front face side of framework, with the not conducting of the electric property of frame.This occasion, the front face side end of housing are in electric property float state, and the shielding character for the radiation noise is descended.

The rear side of basket, housing is connected with frame by Screw, and electrically conducting between the frame backplate.Therefore, housing is connected with the anode part of magnetron by frame and heating clamber, waveguide pipe etc.

The occasion of said structure, the end of its front face side of housing are in electric property float state, and the end of rear side is connected with the anode part of magnetron.Therefore, housing plays the antenna function of emitting the radiation noise, and the shield effectiveness of housing descends.

Here, the relation of representing frequency f and wavelength X, 1/4 wavelength with Figure 11 A.In addition, Figure 11 B represents the relation of the shell dimension etc. of micro-wave oven A～E.Figure 11 C represents the width W of housing parts of micro-wave oven and the relation of height H, depth degree D etc.

Among Figure 11 B, W is the width of housing 102, H is the height of housing 102, D is the depth degree of housing 02, (W+2H) be the size that width W adds 2 times height H, fw is the frequency that width W becomes 1/4 wavelength, and fH is the frequency that height H becomes 1/4 wavelength, (fw+2H) is the frequency that size (W+2H) becomes 1/4 wavelength.

Can think that from above-mentioned relation be equivalent to radiate the occasion of 1/4 wavelength of frequency noise such as the width W of housing 102 and height H, size (W+2H), housing 102 plays the function of antenna with respect to the radiation noise.

The present invention is in order to address the above problem, and its purpose is to provide a kind of micro-wave oven that can suppress the radiation noise.

Summary of the invention

A kind of form of the present invention is that a kind of micro-wave oven comprises:

Magnetron device comprises: have anode part, electromagnetic magnetron take place and with described anode part electrically conducting and surround the metal system member of described magnetron;

Can supply with the heating clamber of described electromagnetic electric conductivity;

The frame of the electric conductivity of this heating clamber is installed;

Constitute the housing of the electric conductivity of the basket part that covers described magnetron device and described heating clamber with this frame, it is characterized in that,

Described metal system member and described housing are electrically connected.

In above-mentioned micro-wave oven, the radiator of the electric conductivity that described hardware cools off by the electric conductivity filter cartridge of the input part of the yoke of the electric conductivity that is formed in a part that forms the magnetic loop of using in magnetic field in this magnetron, the described magnetron of folding and unfolding and to described magnetron constitutes, and at least one and described anode part in described yoke, described filter and the described radiator and described housing are electrically connected.

The present invention can realize suppressing the micro-wave oven of radiation noise.

Description of drawings

Figure 1A is the stereogram of the micro-wave oven of the example of the present invention seen from the place ahead of expression.

Figure 1B is the partial enlarged drawing of Figure 1A.

Fig. 2 A is the side view of the employed magnetron device of this example of expression.

Fig. 2 B is the side view that expression is seen from the right side of Fig. 2 A.

Fig. 3 is the stereogram of the employed frame of this example of explanation.

Fig. 4 is the stereogram of the employed housing of this example of explanation.

Fig. 5 A is the stereogram of the micro-wave oven of other examples of the present invention of seeing from the place ahead of expression.

Fig. 5 B is the partial enlarged drawing of Fig. 5 A.

Fig. 6 A～6E is the performance plot that is used to illustrate characteristic of the present invention.

Fig. 7 A, Fig. 7 B, Fig. 7 C are stereograms explanation other examples of the present invention, a taking-up part.

Fig. 8 A, Fig. 8 B, Fig. 8 C are stereograms explanation other examples of the present invention, a taking-up part.

Fig. 9 A, Fig. 9 B, Fig. 9 C, Fig. 9 D are stereograms explanation other examples of the present invention, a taking-up part.

Figure 10 is the stereogram of expression conventional case.

Figure 11 A is the table of the relation of expression frequency f, wavelength X and 1/4 wavelength.

Figure 11 B is the table of the relation of the shell dimension of expression micro-wave oven A～E etc.

Figure 11 C is the stereogram of the relation of the width W of housing parts of expression micro-wave oven and height H, depth degree D etc.

The specific embodiment

Below, with reference to Figure 1A～Fig. 4 example of the present invention is described.

Figure 1A is the stereogram of the micro-wave oven seen from the place ahead, and Figure 1B is the partial enlarged drawing of Figure 1A.

The basket 10 of micro-wave oven is made of frame 11 and housing 12 etc.Frame 11 is made by the metallic plate bending, is made of framework soleplate 11a and frame header board 11b, frame backboard 11c etc.Be fixed with the heating clamber of being made by metallic plate 13 on framework soleplate 11a, heating clamber can be installed on the part of frame 11 with door 13a with opening and closing.Housing 12 is such as being bent to form コ word shape by 1 metallic plate, is made of

upper wall portions

12a and 2 side wall portion 12b, the 12c etc. that are positioned at about it.In addition, dispose magnetron device 14 on the next door of heating clamber 13.

Magnetron device 14 has the inner space of the vacuum kept, by the electromagnetic magnetron (not shown) that produces high frequency and surround the formations such as metal system member 16 of magnetron.Metal system member 16 is made of yoke 16a and filter cartridge 16b etc.

Yoke 16a has constituted a part that forms the magnetic loop of using in magnetic field in magnetron with magnet and pole piece etc.Filter cartridge 16b is such as constituting by seal the cover b2 that ends etc. with the framework part b1 of yoke 16a adjacency and with the rectangular aperture of framework part b1, be used for the folding and unfolding magnetron input part 15c, such as the bar part of magnetron and input with lead, with import the filter circuit that is connected with lead etc.

The occasion of Figure 1A, Figure 1B, magnetron device 14 are relative configurations of right side wall portions 12c with cover b2 with the housing 12 of filter cartridge 16b.Between this cover b2 and right side wall portions 12c, dispose electroconductive member, make between filter cartridge 16b and the housing 12 to be electrically connected such as conductive sponge 17.And the occasion of the external coating of housing 12, the application in the zone that contacts with conductive sponge 17 should be removed the back and be used.

In addition, between heating clamber 13 and magnetron device 14, be provided with the waveguide pipe 18 that the electromagnetic wave from magnetron device 14 outputs is transmitted.

In the said structure, food etc. are configured in the heating clamber 13 of micro-wave oven.The electromagnetic wave that magnetron device 14 produces is supplied with heating clamber 13 via waveguide pipe 18, makes the food heating in the heating clamber 13.

Here, with reference to Fig. 2 A, 2B described magnetron device 14 is described.Fig. 2 A is a side view, and Fig. 2 B is the figure that expression is seen from the right side of Fig. 2 A, and the part corresponding with Figure 1A, 1B put on same-sign, omits the local explanation that repeats.

Magnetron 15 is made of tubular anode 15a and efferent 15b, input part 15c etc.Constitute by the filter cartridge 16b of yoke 16a that surrounds tubular anode 15a and folding and unfolding input part 15b, radiator 16c etc. between tubular anode 15a and yoke 16a at the metal system member 16 in magnetron 15 outsides.Filter cartridge 16b is such as having framework part b1 and cover b2, and the electric conductivity sponge 17 with elastic force is fixed on the cover b2.In addition, on yoke 16a part, form a plurality of Screws hole 19.

The efferent 15b of magnetron 15 is more outstanding to illustrated top than yoke 16a, and the part of input part 15c connects the framework part b1 of filter cartridge 16b such as capacitive part.

Below, with reference to Fig. 3 frame 11 is described.Fig. 3 is a stereogram of seeing micro-wave oven from rear side, the state after expression is dismantled housing 12 parts from Fig. 1.Part corresponding with Figure 1A, 1B among Fig. 3 is put on same-sign, omits the local explanation that repeats.

Frame 11 is made of framework soleplate 11a and frame header board 11b, frame backboard 11c etc., and heating clamber 13 is fixed on the framework soleplate 11a.Frame backboard 11c goes up and forms a plurality of screw holes 111, is provided with a plurality of tabular claw clinch 112 on frame header board 11b.

Below, with reference to Fig. 4 housing 12 is described.Part corresponding with Figure 1A, 1B among Fig. 4 is put on same-sign, omits the local explanation that repeats.

Housing 12 is such as being bent to form コ word shape by 1 metallic plate.End on 3 limits that are positioned at front face side is provided with return portion 121 respectively, forms a plurality of claws 122 on each return portion 121.Claw 122 is provided with the joint-cutting such as コ word shape in the part of return portion 121, will be mentioned by the inside part De Swam end that this joint-cutting impales.This occasion when laterally seeing, the narrow slit of acute angle occurs between the inside part of the joint-cutting that lifts and the Outboard Sections of joint-cutting.In addition, the rear side of housing 12 is respectively equipped with the inwards kink 123 of bending in the end on 3 limits, forms a plurality of screw holes 124 on kink 123.

Housing 12 is fixed on occasion on the frame 11, and side in front is clipped in the claw clinch 112 of frame front panel 11b in the gap of inclination of housing claw 122 and fixes.Side overleaf, the screw hole 111 that screw is passed the screw hole 124 of housing 12 and frame 11 carries out screw to be fixed.

With the occasion that housing 12 and frame 11 interfix, the electric conductivity sponge 17 that is arranged on the cover b2 of filter cartridge 16b contacts with housing 12, is electrically connected between filter cartridge 16b and the housing 12.

Said structure, frame 11 parts of basket 10 are by welding and riveted joint etc. and heating clamber 13 electrically conductings.The anode part electrically conducting of heating clamber 13 and magnetron 15, the anode part ground connection of magnetron 15.Therefore, frame 11 becomes ground state, has good shielding character.

Housing 12 also is electrically connected and ground connection with the anode part of magnetron 15 by electric conductivity sponge 17 and filter cartridge 16b etc.Therefore, housing 12 can suppress the antenna function for the radiation noise, and guarantees good shielding character, reduces the radiation noise.

Below, with reference to Fig. 5 other examples of the present invention are described.Fig. 5 A is the figure that sees micro-wave oven from front face side, and Fig. 5 B is the enlarged drawing of the major part of Fig. 5 A.Part corresponding with Figure 1A, 1B among Fig. 5 A, the 5B is put on same-sign, omits the local explanation that repeats.

The occasion of this example, magnetron device 14 are towards the outstanding configuration of the front face side of basket 10 with the input part 15c of magnetron 15.This occasion, relative such as 1 face of yoke 16a with the right side wall portions 12c of housing 12.Dispose electric conductivity sponge 17 between 1 face of relative yoke 16a and the right side wall portions 12c.

This occasion, housing 12 also are connected with the anode part of magnetron 15 by electric conductivity sponge 17 and yoke 16a, are in ground state.Therefore, housing 12 can suppress the antenna function for the radiation noise, and guarantees good shielding character, reduces the radiation noise.

Here, Fig. 6 A～6E represents for the result who is configured to the measured radiation noise of the micro-wave oven A～E shown in Figure 1A, 1B or Fig. 5 A, the 5B in basket 10, with magnetron device 14.Micro-wave oven A～E is corresponding with micro-wave oven A～E of Figure 11 B.In addition, the transverse axis of Fig. 6 A～6E is frequency (MHz), and the longitudinal axis is radiation noise intensity (dB μ V/m), and symbol S is a specification value.The measuring method of radiation noise is carried out according to CISPR11 (International Special Committee on Radio Interference 11): 1997+Amendmentl:1999.In addition, the characteristic of the invention structure that housing 12 and magnetron device 14 are electrically connected is represented the characteristic usefulness * expression of the traditional structure that is not electrically connected with zero.

Shown in Fig. 6 A～E, all in the scope of 30MHz～1000MHz, invention structure (zero mark) is compared with traditional structure (* mark) has good characteristic to each micro-wave oven A～E.Especially the inhibition effect at 30MHz～500MHz frequency band increases.

Can think that these frequency bands are because cause consistent as the frequency band that 1/4 wavelength antennas works with each size such as width of housing, that the antenna function for the radiation noise is descended.

The occasion of micro-wave oven A, B, shown in Fig. 6 A and Fig. 6 B, traditional structure (* mark) has surpassed the setting S of CISPR11.But invention structure (zero mark) is below setting S.

The occasion of micro-wave oven E, traditional structure be with 2 high voltage leads that feedthrough capacitor on the input part that is arranged at magnetron device is connected on ferrite ring is installed, to suppress the radiation noise.Therefore, shown in Fig. 6 E, the occasion of traditional structure (* mark) also can suppress the radiation noise.Such as, in 50MHz～70MHz frequency band, compare with invention structure (zero mark) and to have good characteristic.But, dismantled the occasion (mouthful mark) of ferrite ring, the radiation noise is poorer than invention structure (zero mark).

Below, with reference to taking out its a part of Fig. 7 A, 7B, 7C other examples of the present invention are described.Among Fig. 7 A, 7B, the 7C, the occasion that the configuration of magnetron device 14 is identical with Figure 1A, 1B, the part corresponding with Figure 1A, 1B put on same-sign, omits the local explanation that repeats.

Fig. 7 A is the upper wall portions 12a contacting structure of the yoke 16a and the housing 12 of magnetron device 14.The position corresponding with upper wall portions 12a at yoke 16a is provided with screw hole 71, both is screwed forms firmly contact, and be electrically connected.

Fig. 7 B is fixed on the yoke 16a with the end of screw 73 with lead 72, is fixed on the upper wall portions 12a with the other end of screw 74 with lead 72, is electrically connected between yoke 16a and the housing 12.

Fig. 7 C is configured in electric conductivity sponge 17 between the relative face of yoke 16a and upper wall portions 12a, is electrically connected between yoke 16a and the housing 12.

Below, with reference to taking out its a part of Fig. 8 A, 8B, 8C other examples of the present invention are described.Among Fig. 8 A, 8B, the 8C, the occasion that the configuration of magnetron device 14 is identical with Fig. 5 A, 5B, the part corresponding with Fig. 5 A, 5B put on same-sign, omits the local explanation that repeats.

Fig. 8 A is the right side wall portions 12c contacting structure of the yoke 16a and the housing 12 of magnetron device 14.The position corresponding with right side wall portions 12c at yoke 16a is provided with screw hole 81, the fixing formation firmly of both screws contacted, and be electrically connected.

Fig. 8 B is fixed on the yoke 16a with the end of screw 83 with lead 82, is fixed on the right side wall portions 12c of housing 12 with the other end of screw 84 with lead 82, is electrically connected between yoke 16a and the housing 12.

Fig. 8 C be cover b2 that electric conductivity sponge 17 is configured in filter cartridge 16b with the relative face of upper wall portions 12a between, be electrically connected between cover b2 and the housing 12.

Below, with reference to taking out its a part of Fig. 9 A, 9B, 9C other examples of the present invention are described.Among Fig. 9 A, 9B, 9C, the 9D, the occasion that the configuration of magnetron device is identical with Figure 1A, 1B, the part corresponding with Figure 1A, 1B put on same-sign, omits the local explanation that repeats.

Fig. 9 A is that an end of the leaf spring 91 that will be made by conductive material of screw 92 is fixed on the yoke 16a, and the other end of leaf spring 91 is contacted with the inner face of the upper wall portions 12a of housing 12, is electrically connected between yoke 16a and the housing 12.

Fig. 9 B is that an end of the leaf spring 91 that will be made by conductive material of screw 93 is fixed on the right side wall portions 12c inner face of housing 12, and the other end of leaf spring 91 contact with cover b2 outside, and housing 12 and cover b2 are electrically connected.

Fig. 9 C is the leaf spring 91 that the helical spring that will be made by conductive material 94 replaces Fig. 9 A.This occasion, an end screw of helical spring 94 is fixed on the yoke 16a, and the other end of helical spring 94 contacts with the upper wall portions 12a inner face of housing 12.

Fig. 9 D is the leaf spring 91 that the helical spring that will be made by conductive material 94 replaces Fig. 9 B.This occasion, an end screw of helical spring 94 is fixed on the right side wall portions 12c, and the other end of helical spring 94 contacts with the outside of cover b2.

Among Fig. 7 A～Fig. 9 D, the occasion of the inside surface coating of housing 12, the application of the face that electric conductivity sponge 17 is contacted with lead 72, leaf spring 91, helical spring 94 etc. is removed, and makes electrically conducting.

Above-mentioned example as electroconductive member, has utilized electric conductivity sponge and lead, helical spring, leaf spring.But, also can use other soft electroconductive members such as electric conductivity aluminium strip and steel plate, aluminium sheet etc. to replace above-mentioned member.Thus, even the gap change between magnetron device and housing 12 inner faces also can be kept good being electrically connected.

In addition, the occasion with housing and magnetron device are electrically connected is connected with cover with the yoke of magnetron device.But,, same effect is arranged also even partly be connected such as the framework part of, filter cartridge and radiator etc. with other hardwares parts of the anode part electrically conducting of magnetron.

In addition, with the occasion that housing and magnetron device are electrically connected, the distance that both are electrically connected is short more good more.Therefore, preferably such as connecting between the relative face with housing and magnetron device.

In addition, the link position of magnetron device side is the position of close magnetron preferably, such as partly being connected with the hardware that surrounds magnetron device.As housing is connected with heating clamber, framework soleplate, frame backboard, frame header board etc. such as waveguide pipe with hardware part part in addition, just can not get good effect.Therefore, can think that housing is that directly to carry out conducting be effective for magnetron and electroconductive member by utilizing noise generation source.

Claims

1. micro-wave oven comprises:

Magnetron device, this magnetron device comprises: have anode part, electromagnetic magnetron take place and with described anode part electrically conducting and surround the metal system member of described magnetron;

Be supplied to the heating clamber of described electromagnetic electric conductivity;

The frame of the electric conductivity of this heating clamber is installed;

Described metal system member and described housing are electrically connected.

2. micro-wave oven as claimed in claim 1, it is characterized in that, the radiator of the electric conductivity that described hardware cools off by the electric conductivity filter cartridge of the input part of the yoke of the electric conductivity that is formed in a part that forms the magnetic loop of using in magnetic field in this magnetron, the described magnetron of folding and unfolding and to described magnetron constitutes, and at least one and described anode part in described yoke, described filter and the described radiator and described housing are electrically connected.

3. micro-wave oven as claimed in claim 1 is characterized in that, described metal system member is electrically connected by directly contacting with described housing.

4. micro-wave oven as claimed in claim 1 is characterized in that, has the gap between described metal system member and described housing inner face, is electrically connected by the electric conductivity contact member between described metal system member and the described housing inner face.

5. micro-wave oven as claimed in claim 4 is characterized in that, in described metal system member and housing inner face face position opposite one another, described metal system member and described housing inner face are electrically connected.

6. micro-wave oven as claimed in claim 4 is characterized in that, described contact member has the material that can change the softness of shape according to the variation in described gap.