Abstract:
A part of a body of a high-voltage condenser ( 28 ) is arranged between a lower plate ( 23 ) constituting a heating chamber ( 21 ), and a bottom plate ( 27 ) thereby to reduce attachment dimension of the high-voltage condenser ( 28 ), whereby size-reduction and space-reduction of the high-frequency heating apparatus becomes possible, and an insulation distance between the high-voltage condenser ( 28 ) and metal-made parts constituting the high-frequency heating apparatus can be secured easily, so that the number of the parts can be reduced. Therefore, it is possible to provide the high-frequency heating apparatus which is advantageous also in resources-reduction, assembly efficiency, and price.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to an attachment method of a high-voltage condenser used in a high-voltage circuit of a high-frequency heating apparatus and attachment fittings for the high-voltage condenser.  
           [0003]    2. Description of the Related Art  
           [0004]    In a high-voltage circuit of a high-frequency heating apparatus, a high-voltage condenser has been used till now in order to obtain half-wave voltage double commutation. As its attachment method, there are methods shown in FIGS. 10, 11 and  12 ,  13 .  
           [0005]    In an example shown in FIGS. 10 and 11, below a resin-made orifice  1 , a high-voltage condenser  3  is held between the orifice and a half-oval attachment fittings  2 , and the attachment fittings  2  is fixed with a screw from a side of a back plate  4 .  
           [0006]    In an example shown in FIGS. 12 and 13, a high-voltage condenser  6  is held by an attachment fittings  7 , and the attachment fittings  7  is fixed to a flat portion  8 A of a bottom plate  8  with a screw  9  from the inside.  
           [0007]    However, in the example shown in FIGS. 10 and 11, since the high-voltage condenser  3  is attached below the orifice  1 , the size of the orifice  1  becomes large, so that there is a problem in resources-reduction. Further, since the width of the orifice  1  must be made larger than the length (L1) of the high-voltage condenser  3 , there are problems in size-reduction and space-reduction of the high-frequency heating apparatus. Further, since a terminal portion  3 A of the high-voltage condenser  3  is close to the metal-made back plate  4 , an outer frame  10  and a bottom plate  11 , sufficient insulation distance cannot be secured. Therefore, it is necessary to stick an insulating sheet  12  on the inside of the outer frame  10  or coat a lead wire  13  connecting to the terminal portion  3 A of the high-voltage condenser  3  with an insulating tube  14 , so that there are also problems in resources-reduction, assembly efficiency, and price. Further, since the high-voltage condenser  3  is placed below the orifice  1 , it does not receive wind from a cooling fan  15  at all but is cooled naturally, so that there is a problem in level-up of output.  
           [0008]    Further, in the example shown in FIGS. 12 and 13, the high-voltage condenser  6  is held by the oval attachment fittings  7 , and the attachment fittings  7  is fixed onto the flat portion  8 A of the bottom plate  8  with the screw  9  from the inside. However, similarly to in the example shown in FIG. 10, attachment dimension of the length (L2) of the high-voltage condenser  6  is required, so that there are problems in size-reduction and space-reduction of the high-frequency heating apparatus. Further, since a insulation distance between the high-voltage condenser  6  and a metal-made back plate  16  or an outer frame  17  cannot be sufficiently secured. Therefore, it is necessary to stick an insulating sheet  18  on the inside of the outer frame  17  or coat a lead wire  19  connecting to the high-voltage condenser  6  with an insulating tube  20 , so that there are also problems in resources-reduction, assembly efficiency, and price. Further, since the attachment fittings  7  holding the high-voltage condenser  6  is fixed to the flat portion  8 A of the bottom plate  8  with the screw  9 , the screw  9  protrudes downward from the bottom plate  8 . Therefore, when a user handles the high-frequency heating apparatus, the screw  9  touches his hand, so that an unpleasant feeling or a sense of incompatibility in appearance is given to him.  
         SUMMARY OF THE INVENTION  
         [0009]    In order to solve the problems in size-reduction, space-reduction, resources-reduction, assembly efficiency, and price, in the first aspect of the invention, a part of a body of a high-voltage condenser is arranged between a heating chamber bottom wall and a bottom plate.  
           [0010]    A heating chamber of a high-frequency heating apparatus includes side plates, a lower plate, an upper plate, a front plate and a back plate. Flange portions are formed respectively at the lower portions of the front plate and the back plate, and a bottom plate is fixed to the flange portions of the front plate and the back plate. Apart of the body of the high-voltage condenser is arranged between the lower plate constituting the heating chamber and the bottom plate, the high-voltage condenser is held by an attachment fittings, and the attachment fittings is fixed onto the bottom plate.  
           [0011]    According to the first aspect, since a part of the body of the high-voltage condenser is thus arranged between the heating chamber lower plate and the bottom plate, the dimension regulated by the length of the high-voltage condenser can be reduced, so that size-reduction and space-reduction of the high-frequency heating apparatus are possible.  
           [0012]    Further, an outer frame is attached so as to cover the front plate and the back plate that are attached to the front and the back of the heating chamber. Since by arranging a part of the body of the high-voltage condenser between the heating chamber lower plate and the bottom plate, the insulation distance between a terminal portion of the high-voltage condenser and the outer frame can be sufficiently secured, it is not necessary to-stick an insulating sheet on the outer frame, so that the problems in resources-reduction, assembly efficiency, and price can be also solved.  
           [0013]    In order to solve the problems in resources-reduction, assembly efficiency, and price, in the second aspect of the invention, flange portions are formed respectively at the lower ends of a front plate and a back plate that form a heating chamber, a bottom plate is fixed to the flange portions of the front plate and the back plate, and valley portions drawn downward in order to attach leg rubbers are formed in a bottom plate. A terminal portion of a high-voltage condenser is arranged on the valley portion, and the high-voltage condenser is held through an attachment fittings at a mountainous portion formed at the bottom plate.  
           [0014]    According to the second aspect, the leg rubbers for supporting the high-frequency heating apparatus are attached apart from the back plate and the outer frame so as not to overturn in view of the weight balance of the high-frequency heating apparatus, and the terminal portion of the high-voltage condenser is arranged on the valley portion of the bottom plate formed in order to attach the leg rubber. Hereby, the insulation distance between the terminal portion of the high-voltage condenser and the metal-made back plate or outer frame can be secured sufficiently. Further, since the terminal portion of the high-voltage condenser is arranged on the leg rubber attachment portion formed by drawing the bottom plate downward, the insulation distance between the bottom plate and the terminal portion of the high-voltage condenser can be also sufficiently secured. Therefore, it is not necessary to stick an insulating sheet on the inside of an outer frame or to cover a lead wire with an insulating tube because of shortage of the insulation distance produced in the conventional examples, so that the problems in resources-reduction, assembly efficiency, and price can be solved.  
           [0015]    In order to remove the unpleasant feeling at the handling time or a sense of incompatibility in appearance in the examples, in the third aspect of the invention, flange portions are formed respectively at the lower ends of a front plate and a back plate that form a heating chamber, the front and the back of a bottom plate is fixed to the flange portions of the front plate and the back plate, a high-voltage condenser is held by an attachment fittings, the attachment fittings is fixed to a mountainous portion formed at the bottom plate with a screw from the inside of the bottom portion, and the screw is surrounded by valley portions formed in the bottom plate more deeply than the length of the screw.  
           [0016]    According to the third aspect, though the screw for holding the high-voltage condenser is tightened from the inside of the bottom plate and protrudes downward from the bottom plate, since it is surrounded by the valley portions drawn downward more deeply than the length of the screw, it is possible to solve such the problems that the unpleasant feeling is given by touch of the screw on user&#39;s hand at the carrying time of a high-frequency heating apparatus or a sense of incompatibility in appearance is given because the screw can be seen from the downside of the valley portion of the bottom plate.  
           [0017]    In order to solve the problems in resources-reduction, assembly efficiency, price, and cooling efficiency of high-voltage condenser, in the fourth aspect of the invention, a magnetron is fixed to a magnetron attaching plate fixed to a heating chamber sidewall, a bottom plate is attached to lower ends of a front plate and a back plate that form a heating chamber, a high-voltage transformer is attached on the bottom plate, a cooling motor having a cooling fan is attached to the back plate, a high-voltage condenser is arranged at a position nearer to the windward of the cooling fan than the magnetron and the high-voltage transformer, and the high-voltage condenser is held through an attachment fittings on the magnetron attaching plate.  
           [0018]    According to the fourth aspect, since the high-voltage condenser is thus held through the attachment fittings on the magnetron attaching plate, it can be held at a position sufficiently distant from the metal-made back plate and bottom plate. Therefore, it is possible to solve the problem in resources-reduction, assembly efficiency, and price that a lead wire is covered with an insulating tube. Further, since the high-voltage condenser is arranged at the position nearer to cooling fan than the high-voltage transformer and the magnetron hereby to forcedly receive wind from the cooling fan, cooling performance of the high-voltage condenser improves, so that the problem in level-up of output can be solved.  
           [0019]    In order to solve the problems in size-reduction, space-reduction, resources-reduction, assembly efficiency, and price, according to the fifth aspect of the invention, a drawn portion protruding backward is formed at a back plate constituting a heating chamber, a back portion of a high-voltage condenser is inserted into this drawn portion, a terminal portion side of the high-voltage condenser is held by an attachment fittings, the attachment fittings is fixed to a bottom plate, and the high-voltage condenser is arranged in the depth direction of the high-frequency heating apparatus.  
           [0020]    According to the fifth aspect, since high-voltage condenser is thus held in the depth direction of the high-frequency heating apparatus, it is possible to solve the problem that the size-reduction and space-reduction of the high-frequency heating apparatus are impossible due to the length of the high-voltage condenser. Further, it is easy to secure the insulation distance between the high-voltage condenser and the metal-made back plate, the bottom plate or an outer frame, and it is possible to solve such the problem in resources-reduction, assembly efficiency, and price that an insulating sheet or an insulating tube is used because of shortage of the insulation distance. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]    [0021]FIG. 1 is a perspective view showing an attachment method of a high-voltage condenser in a first embodiment of the invention;  
         [0022]    [0022]FIG. 2 is a sectional view showing an arranging state of the high-voltage condenser in the first embodiment of the invention;  
         [0023]    [0023]FIG. 3 is a transverse sectional view showing an attachment state of the high-voltage condenser in the first embodiment of the invention;  
         [0024]    [0024]FIG. 4 is a sectional view showing an attaching position of a high-voltage condenser in a second embodiment of the invention;  
         [0025]    [0025]FIG. 5 is an exploded view showing an attaching procedure of the high-voltage condenser in the second embodiment of the invention;  
         [0026]    [0026]FIG. 6 is a sectional view showing an attaching state of a high-voltage condenser in a third embodiment of the invention;  
         [0027]    [0027]FIG. 7 is a perspective view showing a shape of a bottom plate in the third embodiment of the invention;  
         [0028]    [0028]FIG. 8 is a side view showing an attaching state of a high-voltage condenser in a fourth embodiment of the invention;  
         [0029]    [0029]FIG. 9 is a side view showing an attaching state of a high-voltage condenser in a fifth embodiment of the invention;  
         [0030]    [0030]FIG. 10 is a perspective view showing an attaching state of a high-voltage condenser in a conventional example;  
         [0031]    [0031]FIG. 11 is a sectional view showing the constitution in the conventional example;  
         [0032]    [0032]FIG. 12 is a sectional view showing an attaching state of a high-voltage condenser in a conventional example; and  
         [0033]    [0033]FIG. 13 is a transverse sectional view showing the constitution in the conventional example. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0034]    Embodiments of the invention will be described below with reference to drawings.  
         [0035]    (Embodiment 1)  
         [0036]    [0036]FIG. 1 is a perspective view showing a high-voltage condenser attaching method in a first embodiment of the invention. FIG. 2 is a sectional view showing an arrangement state of the high-voltage condenser in the first embodiment. FIG. 3 is a transverse sectional view showing an attachment position in the first embodiment.  
         [0037]    A heating chamber  21  of a high-frequency heating apparatus includes side plates  22 , a lower plate  23 , a upper plate  24 , a front plate  25  and a back plate  26 . And, flange portions  25 A and  26 A are formed at lower ends of the front plate  25  and the back plate  26  to attach a bottom plate  27  thereto. A high-voltage condenser  28  is attached through an attachment fittings  29  to the bottom plate  27  so that a part of a body  28 A of the high-voltage condenser  28  is arranged between the lower plate  23  constituting the heating chamber  21  and the bottom plate  27 . In the first aspect, since a part of the body  28 A (having the length L3) of the high-voltage condenser  28  is arranged between the heating chamber lower plate  23  and the bottom plate  27 , the dimension necessary to attach the high-voltage condenser  28  can be reduced, so that size-reduction and space-reduction of the high-frequency heating apparatus can be performed. Further, since dimensional allowances can be provided, an insulation distance between the high-voltage condenser  28  and the metal-made back plate or an outer frame  30  can be easily secured, and it is not necessary to stick an insulating sheet to the outer frame or to cover a lead wire with an insulating tube. Therefore, problems in resources-reduction, assembly efficiency, and price can be solved.  
         [0038]    (Embodiment 2)  
         [0039]    [0039]FIG. 4 is a sectional view showing an attachment position of a high-voltage condenser in a second embodiment of the invention. FIG. 5 is an exploded view showing an attachment procedure of the high-voltage condenser in the second embodiment of the invention.  
         [0040]    In FIGS. 4 and 5, a high-frequency heating apparatus has a heating chamber  31 , and the heating chamber  31  includes a front plate, a back plate, and the like similar to the first embodiment. A bottom plate  34  is attached to lower ends of the front plate and the back plate, and has valley portions  34 A for attaching leg rubbers  35  and mountainous portion  34 B.  
         [0041]    The leg rubbers  35  are attached at positions a little distant from the back plate or an outer frame  38  in order to support the high-frequency heating apparatus with balance. To the mountainous portion  34 B of the bottom plate  34 , a high-voltage condenser  37  is attached through an attachment fittings  36  so that a terminal portion  37 A of the high-voltage condenser  37  is arranged on the valley portion  34 A of the bottom plate.  
         [0042]    Since the terminal portion  37 A of the high-voltage condenser  37  is arranged on the valley portion  34 A formed in the bottom plate  34 , an insulation distance between the terminal portion  37 A of the high-voltage condenser and the metal-made back plate, the bottom plate  34  or the outer frame  38  can be sufficiently secured, and it is not necessary to stick an insulating sheet to the outer frame or to cover a lead wire with an insulating tube. Therefore, problems in resources-reduction, assembly efficiency, and price-can be solved.  
         [0043]    (Embodiment 3)  
         [0044]    [0044]FIG. 6 is a sectional view showing an attachment state of a high-voltage condenser in a third embodiment of the invention. FIG. 7 is a perspective view showing a shape of a bottom plate in the third embodiment of the invention.  
         [0045]    In FIGS. 6 and 7, a high-frequency heating apparatus has a heating chamber  39 , and the heating chamber  39  includes a back plate  40  and the like. A bottom plate  41  is attached to lower ends of the back plate  40 . To a mountainous portion  41 A of the bottom plate  41 , a high-voltage condenser  42  is attached through an attachment fittings  43  with a screw  44  from the inside of the high-frequency heating apparatus. Valley portions  41 B are formed around the mountainous portion  41 A of the bottom plate  41 , which are deeper than the length of the screw  44  protruding downward from the bottom plate  41 .  
         [0046]    In order to hold the high-voltage condenser  42 , the screw  44  thus protrudes downward from the inside of the high-frequency apparatus through the bottom plate  41 . However, such the problems that the unpleasant feeling is given by touch of the screw on user&#39;s hand at the carrying time of the high-frequency heating apparatus and a sense of incompatibility in appearance is given because the screw can be seen from the downside of the bottom plate can be solved because the surroundings of the screw  44  is covered with the valley portions  41 B formed in the bottom plate  41 .  
         [0047]    {Embodiment 4} 
         [0048]    [0048]FIG. 8 is a side view showing an attachment state of a high-voltage condenser in a fourth embodiment of the invention.  
         [0049]    In the figure, a high-frequency heating apparatus has a heating chamber  45 , and the heating chamber includes a front plate  46 , a back plate  47 , side plates  48 , and the like. To the side plate  48 , a magnetron attaching plate  49  is fixed, and a magnetron  50  is attached onto it&#39;s the magnetron attaching plate  49 . To the back plate  47 , a cooling motor  52  having a cooling fan  51  is attached. At lower ends of the front plate  46  and the back plate  47 , a bottom plate  53  is attached, and a high-voltage transformer  54  is fixed onto the bottom plate  53 . A high-voltage condenser  55  is attached through an attachment fittings  56  onto the magnetron attaching plate  49  at a position closer to the windward of the cooling fan  51  than the magnetron  50  and the high-pressure transformer  54 .  
         [0050]    In the fourth embodiment of the invention, since the high-voltage condenser  55  is held on the magnetron attaching plate  49 , it can be held at a position sufficiently distant from the metal-made back plate  47  and bottom plate  53 . Therefore, it is not necessary to cover a lead wire with a insulating tube because of shortage of the insulation distance, so that it is possible to solve the problems in resources-reduction, assembly efficiency, and price.  
         [0051]    Further, since the high-voltage condenser  55  is arranged at the position nearer to cooling fan  51  than the magnetron  50  and the high-voltage transformer  54  and arranged on the windward side of the cooling fan  51  hereby to forcedly receive wind of lower temperature, increase of temperature of the high-voltage condenser  55  can be suppressed more than where natural cooling is performed, so that level-up of output of the high-frequency heating apparatus can be facilitated. In the fourth embodiment, the temperature of the high-frequency heating apparatus can be reduced by 8° C. compared with that in the example shown in FIG. 10.  
         [0052]    (Embodiment 5)  
         [0053]    [0053]FIG. 9 is a side view showing an attachment state of a high-voltage condenser in a fifth embodiment of the invention.  
         [0054]    A bottom plate  60  is attached to lower ends of a front plate  58  and a back plate  59  that constitute a heating chamber  57 . At the back plate  59 , a drawn portion  59 A protruding backward (projecting to outer side of the high-frequency heating apparatus) is formed, a back portion  61 A of a high-voltage condenser  61  is inserted into the drawn portion  59 A, a terminal portion  61 B side of the high-voltage condenser  61  is held by an attachment fittings  62 , the attachment fittings  62  is fixed to the bottom plate  60 , and the high-voltage condenser  61  is arranged in the depth direction of the high-frequency heating apparatus.  
         [0055]    Since the high-voltage condenser  61  is thus arranged in the depth direction of the high-frequency heating apparatus, the width dimension of the high-voltage condenser is sufficient for attachment. Therefore, it is possible to solve the problem that the size-reduction and space-reduction of the high-frequency heating apparatus are difficult, because the dimension is regulated by the length of the high-voltage condenser.  
         [0056]    Further, since the high-voltage condenser  61  is held by the drawn portion  59 A formed at the back plate  59  and the attachment fittings  62  located in the vicinity of the terminal portion  61 B, it is easy to secure the insulation distance between the high-voltage condenser  61  and the metal-made back plate  59  or the bottom plate  60 , and it is not necessary to cover a lead wire with an insulating tube. Therefore, it is possible to solve such the problems in resources-reduction, assembly efficiency, and price.  
         [0057]    Although the description is made with reference to the specific embodiments, however, the present invention is not limited to the embodiments but various variations and modifications can be applied. In addition, each embodiment can be applied to other embodiments.  
         [0058]    As described above, according to the first aspect of the invention, since a part of the body of the high-voltage condenser  28  is arranged between the heating chamber lower plate  23  and the bottom plate  27 , the dimension necessary to attach the high-voltage condenser  28  can be reduced, so that problems in size-reduction and space-reduction of the high-frequency heating apparatus can be performed.  
         [0059]    Further, since dimensional allowances for attachment of the high-voltage condenser  28  can be provided, the distance between the high-voltage condenser  28  and the metal-made back plate  26  or the outer frame  30  can be easily secured. Therefore, it is not necessary to cover the lead wire with the insulating tube, so that the problems in resources-reduction, assembly efficiency, and price can be solved.  
         [0060]    According to the second aspect of the invention, the terminal portion  37 A of the high-voltage condenser  37  is arranged on the valley portion  34 A formed in the bottom plate  34  in order to attach the leg rubber  35 , and the high-voltage condenser  37  is held through the attachment fittings  36  at the mountainous portion  34 B of the bottom plate. Hereby, the insulation distance between the terminal portion  37 A of the high-voltage condenser and the metal-made back plate, the outer frame  38 , or the bottom plate  34  can be secured readily. Therefore, it is not necessary to stick the insulating sheet on the inside of the outer frame or to cover the lead wire with the insulating tube, so that the problems in resources-reduction, assembly efficiency, and price can be solved.  
         [0061]    According to the third aspect of the invention, the attachment fittings  43  for holding the high-voltage condenser  42  is fixed to the mountainous portion  41 A formed at the bottom plate  41  with the screw  44 , and the screw  44  is surrounded by the valley portions  41 B formed in the bottom plate  41 . Hereby, it is possible to solve such the problems that an unpleasant feeling is given by touch of the screw on user&#39;s hand when the high-frequency heating apparatus is carried, and that a sense of incompatibility in appearance is given by the protrusion of the screw from the bottom plate.  
         [0062]    According to the fourth aspect of the invention, the high-voltage condenser  55  is arranged through the attachment fittings  56  on the magnetron attaching plate  49  at the position nearer to the windward of the cooling fan  51  than the magnetron  50  and the high-voltage transformer  54 . Hereby, the insulation distance from the back plate  47  or the bottom plate  53  can be secured sufficiently, and the insulating sheet is not required, so that the problems in resources-reduction, assembly efficiency, and price can be solved. Further, since the high-voltage condenser can be cooled forcedly by the cooling fan  51 , it is possible to suppress increase of the temperature of the high-voltage condenser and level-up of output of the high-frequency heating apparatus can be facilitated.  
         [0063]    According to the fifth aspect of the invention, the high-voltage condenser  61  is held by the drawn portion  59 A formed at the back plate  59  and the attachment fittings  62 , and arranged in the depth direction of the high-frequency heating apparatus. Hereby, the width dimension (W1) of the high-voltage condenser  61  is sufficient for attachment. Therefore, it is possible to solve the problems in size-reduction and space-reduction of the high-frequency heating apparatus. Further, it is easy to secure the insulation distance between the high-voltage condenser  61  and the back plate  59  or the bottom plate  60 , and the insulating sheet or the insulating tube is not required. Therefore, it is possible to solve the problems in resources-reduction, assembly efficiency, and price.