CN2709827Y - Microwave oven - Google Patents

Abstract

The utility model provides a microwave oven which can realize uniform heating aiming at the situation of a load. In the provided microwave oven, an antenna driving part used for driving and inducting the movement of an antenna is divided into two relatively independent parts which are a first driving part and a second driving part, wherein, the first driving part is used for driving the antenna to rotate; the second driving part is used for driving the antenna to do reciprocating movement along an axial direction. The utility model also comprises a position induction part used for obtaining the position information of the axial direction of the antenna. In this way, under the control of a control part of the microwave oven, generally, when rotating, the micro-wave feed-in antenna can carry out reciprocating movement along the axial direction simultaneously. When a user gives the situation of a load, the antenna can be controlled to only rotate and not to do axial movement after the antenna moves to a position which corresponds to the situation of the load along the axial direction. In addition, L-shaped waveguide is used, and a magnet controlled pipe and the antenna driving part are accordingly arranged to cause the structure of the microwave oven to be compact as much as possible.

Description

Microwave oven

Technical field

The utility model relates to a kind of microwave oven, more specifically, relates to a kind of microwave oven with device of controlled microwave feed antenna motion.

Background technology

In general, known microwave oven is to come heat food like this.Magnetron in the microwave oven produces the electromagnetic wave of high frequency, i.e. so-called " microwave ".The microwave that produced enters the furnace chamber that is placed with food through waveguide, and in furnace chamber repeatedly toward interflection, constantly pass food and cause its molecular vibration, come cooking food thereby produce heat.One of microwave oven sixty-four dollar question is exactly the even heating that how to realize food.In the microwave scattering process, if distributing, can not realize in the needed electromagnetic field of even cooking food, will inevitably cause the inhomogeneous of food heating.

Addressing this problem very important a kind of method is exactly to use certain rotating machinery in furnace chamber, for example rotates and enters furnace chamber 1 after metal mode blender or rotable antenna are dispersed microwave as illustrated in fig. 1, perhaps rotates tray food is heated evenly.Existing most of microwave oven is arranged on the sidewall or the top of furnace chamber with the waveguide mouth, is positioned at the rotating disk of furnace chamber bottom by rotation, is heated and food on the rotating disk is rotated.The microwave oven that also has has been cancelled rotating disk, the waveguide mouth is arranged on the top or the bottom of furnace chamber, the metal mode blender of rotation is set simultaneously, after microwave is coupled into furnace chamber at the inlet of waveguide, stir and diffuse to space in the cavity through mode stirrer, thereby realize evenly heating.Disclosed a kind of microwave oven in U.S. Pat 5182426A for example again, control antenna axially moves when carrying out circular motion, thereby reaches the purpose of the microwave that distributes more equably.

But to the food of different profiles, volume and quality, adopt microwave diffusion mode, just make microwave energy not concentrate on the food, repeatedly reflect and lose microwave energy and cause with a kind of repeatability " machinery ".Microwave is in cavity repeatedly in the reflection process, because the metal surface resistance of cavity and the inherent loss of glass tray all can cause energy to scatter and disappear, and the many more losses of order of reflection are big more; Too much microwave reflection also may make the standing-wave ratio of microwave oven waveguide system bigger, and reduces the life-span of magnetron.On the other hand, the user but can't customize the mode of heating to these foods when the height of determining food, shape, for example will cause bigger cold and hot difference in the plane of thin piece food like this, the significantly phenomenon such as non-uniform temperature up and down in the high cup milk heating process.

Another one problem in the microwave oven design is how to make structure compact as far as possible.As shown in Figure 2, microwave excitation and transmission means that the microwave current stove is commonly used have 3 kinds: the coupling of right side waveguide among Fig. 2 A, and magnetron 2 is coupled to microwave in the furnace chamber 1 by right side waveguide 301; The coupling of top side waveguide among Fig. 2 B, magnetron 2 are led 302 by the long wave at furnace chamber 1 top microwave are coupled in the furnace chamber 1; The coupling of bottom side waveguide among Fig. 2 C, magnetron 2 are led 303 by the long wave of furnace chamber 1 bottom microwave are coupled in the furnace chamber 1.These layouts are structurally not compact, and are especially true behind the drive part that adds antenna.

The utility model content

The technical problems to be solved in the utility model provides a kind of microwave oven, the microwave feed antenna is moved reciprocatingly in rotation vertically, and when the given loading condition of user (for example height), can control antenna axially move to heat the corresponding position of object height degree after only rotation and not axially moving, thereby more even heat food.The another one purpose is rationally to arrange the relative position of magnetron, waveguide and antenna drive part, makes microwave oven structure compact as far as possible.

For solving the problems of the technologies described above, basic design of the present utility model is: the antenna drive part that will be used to drive with the induction antenna motion is divided into two relatively independent parts: first drives, and is used to drive described antenna rotation; Second drives, and is used to drive described antenna and moves reciprocatingly vertically.And comprise the location sensitive part, be used to obtain the current axial location information of antenna.Like this, control section in the microwave oven just utilizes this axial location information and user's setting, control first and drive and second operation that drives,, perhaps after reaching given axial location, rotate and do not axially move so that antenna or rotation edge, limit axially move reciprocatingly.

So, when the antenna drive part is installed in the microwave oven bottom,, can on lower position, rotate by control antenna for lower food; And to higher food, can on higher position, rotate by control antenna; To there being height to have food low or that shape is indefinite then axially to move reciprocatingly at rotation edge in control antenna limit.So just realized changing the even distribution pattern of microwave, and heated more efficiently at loading condition.When the antenna drive part is installed in other position of microwave oven, can change the position of antenna equally at load, just the efficiency of heating surface is low, because food generally all is placed on the bottom of microwave oven.

Preferably, described first driving and second drives and can comprise different drive motors respectively, and becomes real drive.Can certainly drive with same drive motors, and realize different forms of motion with certain mechanism, various well known organizations of driving-belt, travelling gear or the like for example, but in these mechanisms, to add the switch that to assign to control by control part, only to allow first to drive or second drive operation when being necessary.Second driving can use any known mechanism to convert rotatablely moving of motor to reciprocal rectilinear motion, for example inclined-plane, helicla flute, cam, rack-and-pinion, turbine and worm or the like.Preferably, in second drives, be used for making smooth bevel on the driving wheel of linear reciprocating motion of direct driven antenna.

The location sensitive part can comprise any known position transducer, for example sensitive switch, photoelectric sensor or the like.Preferably use sensitive switch, correspondingly, there is a cam at the height place that driving wheel is different from smooth bevel in the axial direction, described cam is by the circular arc be combined into of two different radiis, and sensitive switch and driving wheel in the heart distance be slightly less than radius than orthodrome greater than the radius of less circular arc.Like this, when driving wheel rotates, sensitive switch will with contact and connect than orthodrome, do not contact with less circular arc and disconnect.Control section just can be gathered the state of sensitive switch and obtain the positional information of driving wheel, thereby obtains antenna positional information in the axial direction.

In addition for compact conformation, and waveguide design is become L shaped, its outer longer sides is first limit, and outer is second limit than minor face, and inner longer sides is the 3rd limit.And first limit is fixed on the face of furnace chamber, magnetron irradiates microwaves into the waveguide from second limit, and the antenna drive part is installed on the 3rd limit.Preferably, antenna and tray all are located at the bottom of described furnace chamber, are about to first limit and are fixed on the bottom surface of furnace chamber, and this spline structure is the compactest, and is most effective.

Description of drawings

Label identical in the accompanying drawing is indicated similar part, wherein:

Fig. 1 is the schematic diagram that microwave is coupled into furnace chamber in the microwave oven;

Fig. 2 is the three kinds of microwave excitations of microwave oven in the prior art and the schematic diagram of transmission means;

Fig. 3 is comparison according to coupled waveguide in the microwave oven of an embodiment of the utility model and schematic diagram by the traditional approach coupled waveguide;

Fig. 4 is the structural representation according to waveguide bend 3 in the microwave oven of an embodiment of the utility model;

Fig. 5 is the cross-sectional schematic according to waveguide bend 3 in the microwave oven of an embodiment of the utility model and antenna 7 parts;

Fig. 6 is the structural representation according to antenna 7 in the microwave oven of an embodiment of the utility model;

Fig. 7 drives 4 perspective diagram according to antenna in the microwave oven of an embodiment of the utility model;

Fig. 8 is according to the schematic diagram that drives near guide shaft 17 structures in the microwave oven of an embodiment of the utility model;

Fig. 9 drives 4 floor map according to antenna in the microwave oven of an embodiment of the utility model;

Figure 10 is according to the driving guide shaft 17 in the different moment in the microwave oven of an embodiment of the utility model and the schematic diagram of corresponding sensitive switch state; With

Figure 11 is the flow chart according to embodiment of the utility model method of controlled microwave feed antenna motion in microwave oven.

Embodiment

Below with reference to accompanying drawing, describe preferred embodiment of the present utility model in detail.

As shown in Figure 3A, comprise furnace chamber 1, magnetron 2 according to the microwave oven of an embodiment of the utility model and the waveguide 3 in the furnace chamber of the microwave radiation that is used for magnetron 2 is produced.Comprise also that in addition microwave feed antenna (not shown, hereinafter to be referred as antenna) and antenna drive 4.For contrast the layout that has illustrated by traditional coupled modes in Fig. 3 B, magnetron 2 is vertically placed, and microwave is coupled to furnace chamber 1 by rectangle straight wave guide 304 with microwave, and this kind mode needs the spatial altitude of microwave oven bottom to be at least L2.And, adopt the waveguide bend 3 of " L " type according to embodiment of the present utility model, with magnetron 2 traverses, it is L1 that this kind mode needs microwave oven bottom space height.L2 is greater than L1 when other condition is identical, and the position, turning of waveguide bend 3 can be placed antenna and be driven 4 simultaneously, makes microwave oven compact more like this, and has saved space and cost.The concrete overall dimension of waveguide 3 can be determined according to guide wavelength and energized position.As shown in Figure 4, the insertion coupling aperture 5 of antenna axis is arranged on the long surface of waveguide bend 3, have magnetron to insert mouth 6 on the side.

Antenna and antenna are described below drive 4 layout and installation.As shown in Figure 5, at the back side of waveguide bend 3 welding antenna drive installation plate 16, antenna drives 4 and is fixed on the mounting panel 16 by screw 18.Antenna drives the 4 driving guide shafts 17 that driven and gos deep into waveguide inside by the hole 15 at waveguide bend 3 back sides, and cooperates with antenna axis 9, and antenna axis 9 is deep into the lower space 11 of furnace chamber 1 by coupling aperture 5.11 middle parts are provided with axle sleeve 10 in the space, and axle sleeve 10 can be reduced the wastage and anti-high temperature more than 200 ℃ by the engineering plastics manufacturing of low-k.Axle sleeve mesopore 101 play the guiding role, and prevents from deflection to occur in antenna axis 9 axial motions and rotation process, and has influence on the level of antenna 7.Slot 13 on furnace chamber base plate 12, the installation claw 102 of axle sleeve 10 13 is fixed on the base plate 12 by slotting.

The bottom surface of general furnace chamber 1 is an evagination, and forms space 11 thus, and antenna 7 is located in the space 11.Antenna 7 can be fixed on the front end of antenna axis 9 by variety of way.Be convenient and install that antenna axis 9 is made by pottery, its preceding end section is the D type, and the axis hollow of antenna 7 also is enclosed within on the antenna axis 9, is connected by riveting point 8.Certainly the preceding end section of antenna axis 9 can be set to other shape, and the axis of antenna 7 also is designed to hollow shape correspondingly, so that antenna axis 9 cooperates with antenna 7.

The top of antenna 7 is with tray 14 cappings, and the devitrified glass manufacturing that tray 14 can be absorbed by high temperature resistant, high strength, low microwave also can be by for example other low-k, low-loss made of pottery.The periphery of tray 14 is with silica gel 20 sealings.Such structure can hold weight, can prevent that again the moisture in the furnace chamber 1 from entering into furnace chamber bottom space 11.

The shape of antenna 7 has multiple, and is different with the difference of microwave oven cavity size, is generally an approximate disk, as shown in Figure 6.Disk is provided with the fluting (λ is the wavelength of microwave) of half-wave dipole structure or λ/10～λ/2, and surface current excites at the fluting place and is the microwave dissipate energy.It is in order to disperse microwave better like this that fluting is sized to.The disc centre place is an axis, and axis on the one hand cooperates to come driven antenna 7 to rotate with antenna axis 9, stretches on the other hand will be excited energy in the waveguide and be sent on the antenna surface.Axis is connected with riveted joint or screw with disk.Antenna 7 is aluminum material or similar metal material.

Describe antenna below in detail and drive 4 structure.Antenna drives 4 and comprises second driving and the sensitive switch that first of driven antenna 7 rotations drive, driven antenna 7 moves reciprocatingly vertically.First driving and second in the present embodiment drives and comprises different drive motors respectively, is really independently to drive.But also can drive with same drive motors, and between two drivings, realize different forms of motion with certain mechanism, various well known organizations of driving-belt, travelling gear or the like for example, just to add the switch that to assign to control by control part in these mechanisms, only to allow first to drive or second drive operation when being necessary.

As shown in Figure 7, in first drove, first drive motors 401 drove driving wheel 402 and rotates, and driving torque is sent to gear drive axle 404 by gear 403, made therefrom to drive guide shaft 17 and antenna axis 9 rotations, finally drove antenna 7 and did the circumference rotation.In second drove, second drive motors 405 drove driving wheel 406 and rotates, and driving torque is sent to driving wheel 408 by gear 407.

Second driving can use any known mechanism to convert rotatablely moving of motor to reciprocal rectilinear motion, for example inclined-plane, helicla flute, cam, rack-and-pinion, turbine and worm or the like.Adopt the structure of smooth bevel to realize in the present embodiment.As shown in Figure 8, driving wheel 408 mainly comprises two parts except travelling gear: a part is a smooth bevel 4081, just axially raising the bottom surface 172 that drives guide shaft 17 when it rotates being driven by second drive motors 405, thereby rotation is being converted to the axially reciprocating that drives guide shaft 17; A part is a cam 4082 in addition, and it is by the circular arc be combined into of two different radiis.In Fig. 8, only show the structure relevant, and omitted other structure with driving guide shaft 17.For driving guide shaft 17 can be axially moved in rotation, just driving the side fluting 171 of guide shaft 17, the position of fixed gear driving shaft 404 also adds two flank strip projections 4041 on its axle 4042, in projection 4041 embedded grooves 171.Like this, projection 4041 guarantees to drive guide shaft 17 and can rotate with gear drive axle 404, and groove 171 guarantees that bottom surface 172 can axial motion.And, when driving wheel 408 does not rotate and gear drive axle 404 when rotating, just can make to drive guide shaft 17 and only rotates and do not axially move, thereby make first to drive and second driving becomes two independently drivings.

Fig. 9 is that antenna drives 4 plane graph to sensitive switch 409 (its position only is signal) when connecting.Can certainly use other position transducer as the location sensitive part, photoelectric sensor or the like for example, here only as an example with sensitive switch.Sensitive switch 409 contacts with cam 4082 and can cause sensitive switch 409 to be connected.Because distance in sensitive switch 409 and the driving wheel 408 in the heart, be arranged to be slightly less than radius than orthodrome greater than the radius of cam 4082 less circular arcs, so when driving wheel 408 rotations, sensitive switch 409 will the time and connect, the time and disconnect.As long as cam 4082 less circular arcs and be not 180 ° than the segment angle angle of orthodrome just can obtain the positional information of driving wheel 408 from the state of sensitive switch 409.This information can pass to the control section of microwave oven.

Control section refers generally to the little process chip control board in the microwave oven, wherein be solidified with the antenna driver at the different user menu, this program comes control antenna to drive 4 operation and energy failure judgement according to the state of the sensitive switch of being gathered 409 and user's selection.Describe the process of The whole control and operation in detail below in conjunction with Figure 10 and Figure 11.

Figure 10 is according to the driving guide shaft 17 in the different moment in the microwave oven of an embodiment of the utility model and the schematic diagram of corresponding sensitive switch state, wherein two parts are respectively the schematic diagrames of overlooking and facing up and down, for clarity sake the cam 4082 of not shown driving wheel 408 in front elevational schematic.As seen from the figure, driving wheel 408 revolutions move a week, sensitive switch 409 with regard to break-make once, so control section can carry out fault judgement according to break-make.As Figure 11, suppose that the cycle that driving guide shaft 17 rotates is T under the driving of antenna driving 4, if do not collect make-and-break signal (step 1103) in the operating time in predetermined a plurality of (for example 3) cycles (step 1102) inner control part, judge that then antenna drives 4 faults (step 1104).

If it is 4 working properly that antenna drives, then cook respectively and handle according to common food cooking and spontaneous menu.For the bread and cheese cooking (step 1105), first drive motors 401 and second drive motors 405 all move (step 1106), gear drive axle 404 and driving wheel 408 are all rotated, thereby make to drive guide shaft 17 and antenna 7 while rotating axially carrying out reciprocal rectilinear motion, also can obtain satisfied heats to general food like this.

For the cooking (step 1107) of spontaneous menu, the height that at first will determine to drive guide shaft 17 is the moment of H0, and with reference to figure 10A as can be known, this moment, sensitive switch 409 was in by the logic break-make point that is disconnected to connection, control section with this point as with reference to point.When microwave oven is made, the optimum height of antenna 7 when manufacturer has determined the food of heating differing heights, generally speaking, the high more antenna 7 of food just need be stretched highly more.Below only as an example, and the rule of the medium-altitude kind of actual conditions even definite antenna height can change according to actual microwave oven structure and situation with the food of three kinds of height.The height of supposing the best heats requirement driving guide shaft 17 of thin piece food (for example fried egg) is H1 (Figure 10 B), it is H2 (Figure 10 C) that intermediate gauge food (for example bowl is adorned the heat of turning over of food) requires the height of driving guide shaft 17, and it is H3 (Figure 10 D) that highly higher food (for example high cup milk) requires the height of driving guide shaft 17.

Because the rotating speed and the cycle of second drive motors 405 all are known to control section, so can be by calculating and at the experiment of concrete structure (for example slope of smooth bevel or the like), just can obtain to make driving guide shaft 17 to move to H1, H2, H3 respectively in advance from H0, second drive motors, the 405 required time that works on, for example T/X, T/Y, T/Z.Like this, in user's use, when the user has selected a kind of food type, for example high cup milk (step 1112), then control section control second drive motors 405 after the reference point of determining the H0 height works on the time (step 1113) of T/Z, make to drive the height that guide shaft 17 arrives H3, also reach predetermined height thereby drive antenna blade 5.At this moment, control section is controlled second drive motors 405 quit work (step 1114).First drive motors, 401 continuous runnings during this period make antenna 7 rotate on predetermined altitude.Therefore, just realized changing the motion of antenna, thereby obtained desirable microwave distribution situation at loading condition.

Claims (8)

1. microwave oven comprises:

Furnace chamber is provided with opening;

Waveguide is used for the microwave that magnetron produces is radiated in the described furnace chamber by described opening;

The microwave feed antenna comprises antenna blade and antenna axis, and described antenna blade is positioned at described furnace chamber and links to each other with described antenna axis, and described antenna axis stretches out described furnace chamber by described opening;

The antenna drive part links to each other with described antenna and is used to drive and responds to the motion of described antenna, and comprising: first drives, and is used to drive described antenna rotation; Second drives, and is used to drive described antenna and moves reciprocatingly vertically; With the location sensitive part, be used to obtain the current axial location information of antenna; And

Control section, the described axial location information of utilizing described location sensitive partly to obtain, drive and described second operation that drives and control described first, so that described antenna or limit rotation edge axially moves reciprocatingly, perhaps after reaching given axial location, only rotate and do not axially move.

2. microwave oven as claimed in claim 1, wherein said waveguide is L-shaped, its outer longer sides is first limit, outer is second limit than minor face, inner longer sides is the 3rd limit, and described first limit is fixed on the face of described furnace chamber, and described magnetron irradiates microwaves into the described waveguide from described second limit, and described antenna drive part is installed on described the 3rd limit.

3. microwave oven as claimed in claim 2, wherein said first limit is fixed on the bottom surface of described furnace chamber.

4. microwave oven as claimed in claim 1, wherein said first driving and described second drives and comprises first drive motors and second drive motors respectively.

5. microwave oven as claimed in claim 4, wherein said first driving also comprises first running part and the driving guide shaft that cooperates with described antenna, described first drive motors assigns to drive described driving guide shaft rotation by described first driving section, and further drive the rotation of described antenna, and described driving guide shaft can with the appropriate section of first running part slide relative vertically.

6. microwave oven as claimed in claim 5, wherein said second driving also comprises second running part and driving wheel, on the described driving wheel axial first highly the place smooth bevel is arranged, when described second drive motors assigned to drive the rotation of described driving wheel by described second driving section, described inclined-plane drove the reciprocating motion in the axial direction of described driving guide shaft.

7. microwave oven as claimed in claim 6, wherein said location sensitive partly comprises sensitive switch, and on the described driving wheel axial second highly the place cam is arranged, described cam is by the circular arc be combined into of two different radiis, and described sensitive switch and described driving wheel in the heart distance be slightly less than radius than orthodrome greater than the radius of less circular arc.

8. microwave oven as claimed in claim 1, wherein said control section mainly comprises little process chip, it realizes described control by execution command.

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