Patent Publication Number: US-8978393-B2

Title: Outdoor unit of air conditioner

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is based on, and claims priority from, Japanese Application Serial Number JP2011-18323, filed Jan. 31, 2011, the disclosure of which is hereby incorporated by reference herein in its entirety. 
     TECHNICAL FIELD 
     The present invention relates to an outdoor unit of an air conditioner, and more particularly, to a structure of an electrical component box provided in an outdoor unit. 
     BACKGROUND ART 
     Conventionally, an air conditioner installed in a building such as a condominium or an ordinary house includes: an outdoor unit installed outside of the building; and an indoor unit installed on a ceiling or a wall surface inside of the building. It is known that the outdoor unit is connected to the indoor unit by refrigerant piping. The inside of the outdoor unit is divided by a partition plate attached to a bottom plate constituting part of a casing of the outdoor unit, into a blower chamber in which a heat exchanger, a blower fan, and the like are installed and a machinery chamber in which a compressor, an accumulator, and the like are provided. An electrical component box is placed above the machinery chamber, and the electrical component box includes: a power supply apparatus that supplies driving electric power to apparatuses such as the compressor and the blower fan provided in the outdoor unit; and a control board that controls the operation of the outdoor unit. 
     For example, Japanese Patent Application Publication No. 2008-116137 describes an electrical component box including: a first plate-like member placed on the front side; a second plate-like member placed on the blower chamber side; and a plurality of coupling members that couple the first plate-like member to the second plate-like member, both the first plate-like member and the second plate-like member having a rectangular shape extending in the top-bottom direction. In this electrical component box, the first plate-like member and the second plate-like member are placed in a substantially V-shape as viewed from the top, and the upper end part, lower end part, or central part of the first plate-like member is coupled to that of the second plate-like member by the coupling members. 
     The first plate-like member has, attached thereto: an inverter board constituting the power supply apparatus that supplies driving electric power to the compressor and the blower fan provided in the outdoor unit; and a capacitor, a power module, and a reactor having a large amount of heat generation. In addition, the second plate-like member has, attached thereto, the control board that controls the operation of the outdoor unit and has a small amount of heat generation. 
     Unfortunately, in the above-mentioned structure of the electrical component box, the first plate-like member and the second plate-like member, which are placed in the substantially V-shape, are supported by only the plurality of coupling members arranged like a bridge therebetween, and the plurality of coupling members obliquely support the first plate-like member and the second plate-like member. Accordingly, if the electrical component box receives an impact in the front-back direction, the left-right direction, or the top-bottom direction, the electrical component box may deform. 
     The present invention has been made in order to solve the above-mentioned problem, and therefore has an object to provide an outdoor unit of an air conditioner capable of ensuring strength against an impact that is applied to an electrical component box in the front-back direction, the left-right direction, or the top-bottom direction. 
     SUMMARY OF THE INVENTION 
     In order to solve the above-mentioned problem, an outdoor unit of an air conditioner according to the present invention includes an electrical component box including: a partition plate; a front plate; and a box base plate that receives the partition plate and the front plate, and one end of the partition plate is coupled to one end of the front plate. Then, the electrical component box further includes an L-shaped arm, and the arm has one end that abuts at a right angle against a rear surface of the front plate and another end coupled to another end of the partition plate. The electrical component box further includes a support post that is joined perpendicularly to the arm and the box base plate and supports the arm and the box base plate in the top-bottom direction. 
     The outdoor unit thus configured of the air conditioner according to the present invention has the structure of the electrical component box, in which: the partition plate and the front plate are fixed to the box base plate; the partition plate and the front plate are coupled to each other by the arm; the one end of the arm abuts at a right angle against the rear surface of the front plate; and the support post is joined perpendicularly to the arm and the box base plate and supports the arm and the box base plate in the top-bottom direction. With this structure, strength high enough to withstand an impact applied in the front-back direction, the left-right direction, and the top-bottom direction of the electrical component box can be obtained, so that deformation of the electrical component box can be prevented. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an external perspective view illustrating a front side of an outdoor unit according to the present invention; 
         FIG. 2  is an external perspective view illustrating a back side of the outdoor unit according to the present invention; 
         FIG. 3  is a schematic perspective view illustrating an internal structure of the outdoor unit according to the present invention; 
         FIG. 4  is an enlarged view of a part A in  FIG. 3  and is a perspective view of an electrical component box according to the present invention; 
         FIG. 5  is a perspective view of the electrical component box, which is taken in a direction indicated by an arrow B in  FIG. 4 ; 
         FIG. 6  is a perspective view of the electrical component box, which is taken in a direction indicated by an arrow C in  FIG. 4 ; 
         FIG. 7A  is an exploded perspective view illustrating a main part of the electrical component box; 
         FIG. 7B  is a perspective view illustrating the main part, which is taken from a lower partition plate side; 
         FIG. 8  is an explanatory view of an upper partition plate, a front plate, and a front plate cover; 
         FIG. 9  is a cross-sectional view taken along a line T-T in  FIG. 3 ; 
         FIG. 10  is a view for describing flows of air in the electrical component box; 
         FIG. 11  is an exploded view of a water blocking member, which is taken in a direction indicated by an arrow E in  FIG. 7A ; 
         FIG. 12  is an enlarged view of a part D in  FIG. 4 ; 
         FIG. 13  is a cross-sectional view taken along a line X-X in  FIG. 12  and is a view for describing flows of air from the electrical component box to a blower chamber; 
         FIG. 14  is a cross-sectional view taken along a line Y-Y in  FIG. 12  and is a view for describing flows of air from the electrical component box to the blower chamber; 
         FIG. 15A  is a perspective view for describing a state where the front plate is joined to the upper partition plate; 
         FIG. 15B  is an explanatory view of a part G in  FIG. 15A ; 
         FIG. 16  is an explanatory view of a rotation state of the front plate; and 
         FIG. 17  is an explanatory view for joining the front plate cover to the upper partition plate. 
     
    
    
     DETAILED DESCRIPTION 
     An outdoor unit  1  of an air conditioner according to the present invention is installed outdoors, and is connected to at least one indoor unit installed in an air-conditioned room by refrigerant piping, to thereby constitute a refrigeration cycle. 
     Hereinafter, an embodiment of the present invention is described in detail with reference to the attached drawings. As illustrated in  FIG. 1  to  FIG. 3 , the outdoor unit  1  of the air conditioner according to the present embodiment includes a substantially parallelepiped casing. The outer frame of the casing is formed by processing mainly a steel plate, and includes an L-shaped front panel  1   a  also serving as one side panel, an L-shaped back panel  1   d  also serving as another side panel, a service panel  1   m , a bottom plate  1   h , a top plate  1   n , a front piping cover  1   t , and a side piping cover  1   w . The lower ends of the front panel  1   a , part of the back panel  1   d , the front piping cover  1   t , and the side piping cover  1   w  are screwed to a flange in the periphery of the bottom plate  1   h . The upper ends of the front panel  1   a  and the back panel  1   d  are screwed to the top plate  1   n  so as to be covered by the top plate  1   n.    
     Note that description is given below assuming in the following manner. That is, in the casing of the outdoor unit  1  in  FIG. 1 , the side on which the front panel  1   a  is placed is the front, and the opposite side to the front is the back. Further, when the front panel  1   a  is viewed from the front, the side on which the service panel  1   m  is placed is the right, and the opposite side to the right is the left. 
     The inside of the casing of the outdoor unit  1  is divided by an upper partition plate  61  and a lower partition plate  50  as partition plates into a blower chamber  10  and a machinery chamber  11 . The blower chamber  10  is mainly provided with two blower fans  20  and a heat exchanger  30 . The heat exchanger  30  is formed into a substantially L-shape as viewed from the top, and is placed along from the left side to the back side of the casing of the outdoor unit  1 . The two blower fans  20  are respectively attached to motors (not illustrated). The motors are attached to a motor support  40  fixed to the heat exchanger  30  with a predetermined vertical interval therebetween, whereby the two blower fans  20  are vertically aligned in the blower chamber  10 . 
     A compressor, an accumulator, a four-way valve, and piping are housed in the machinery chamber  11 . An electrical component box  60  is placed above the machinery chamber  11 . The electrical component box  60  is fixed to the lower partition plate  50  with the intermediation of a box base plate  62  that receives the electrical component box  60 . The lower partition plate  50  is made of a steel plate, and has: one side end fixed to the right end of the front panel  1   a ; and another side end fixed to a piping outlet (not illustrated) on the back side of the heat exchanger  30 . The lower end of the lower partition plate  50  is in contact with the bottom plate  1   h . As illustrated in  FIG. 7B , the lower partition plate  50  is bent so as to protrude toward the blower chamber  10 , and the front side thereof with respect to the bent portion is a first partition part  50   b , whereas the back side thereof with respect to the bent portion is a second partition part  50   d . A bent part  50   c  bent in multiple steps is provided at the leading end part of the first partition part  50   b . A leading end surface of the bent part  50   c  is substantially parallel to the front surface of the outdoor unit  1 . In addition, a flange  50   e  bent toward the back side is provided at the leading end part of the second partition part  50   d . Furthermore, a receiving part  50   a  bent inward is provided at the upper end parts of the first partition part  50   b  and the second partition part  50   d.    
     As illustrated in  FIG. 1  to  FIG. 3 , the front panel  1   a  is formed by bending a steel plate into a substantially L-shape as viewed from the top, from the front side to the left side of the outdoor unit  1 . The front panel  1   a  is placed so as to cover a portion corresponding to the blower chamber  10  on the front side of the casing of the outdoor unit  1  and the entire left side of the outdoor unit  1 . On the front side of the front panel  1   a , two blow-off windows  1   s  are opened into a circular shape at positions respectively corresponding to the blower fans  20 , and the blow-off windows  1   s  discharge, to the outside, air that has been suctioned into the blower chamber  10  of the outdoor unit  1  by the blower fans  20 . Fan guards  1   b  that respectively cover the blow-off windows is are attached to the front panel  1   a . A suction port  1   q  formed of a plurality of rectangular holes is provided on the left side of the front panel  1   a.    
     The back panel  1   d  is formed by bending a steel plate into a substantially L-shape as viewed from the top, from the back side to the right side of the outdoor unit  1 . The back panel  1   d  is placed so as to cover the back side of the machinery chamber  11  of the outdoor unit  1  and cover the right side of the outdoor unit  1  together with the service panel  1   m  to be described later. An air intake hole  1   f  is opened in a back-side lower portion of the back panel  1   d , and the air intake hole  1   f  serves to take external air into the machinery chamber  11  by means of the blower fans  20 . 
     The service panel  1   m  is formed by bending a steel plate into a substantially L-shape as viewed from the top, from the front side to the right side of the outdoor unit  1 . The service panel  1   m  is placed so as to cover a portion corresponding to the machinery chamber  11  of the outdoor unit  1  and cover the right side of the outdoor unit  1  together with the back panel  1   d . The service panel  1   m  is detachably attached in order to facilitate access to the machinery chamber  11  at the time of maintenance work for the outdoor unit  1 . 
     Note that the heat exchanger  30  is exposed between the side end of the back panel  1   d  and the side end of the front panel  1   a  on the back side of the casing of the outdoor unit  1 , and the exposed portion serves as a back suction port  1   e  for taking external air into the blower chamber  10  by means of the blower fans  20 . A protecting member  1   g  is provided for the back suction port  1   e.    
     The bottom plate  1   h  is made of a steel plate having a substantially rectangular shape, and the flange bent upward at a substantially right angle is formed in the periphery of the bottom plate  1   h . In addition, leg parts  1   c  extending in the front-back direction of the outdoor unit  1  are provided at right and left portions on the lower surface of the bottom plate  1   h , and the leg parts  1   c  serve for installation of the outdoor unit  1  on the ground or the like. 
     The top plate  1   n  is made of a steel plate having a substantially rectangular shape, and a flange bent downward is formed in the periphery of the top plate  1   n . The top plate  1   n  is screwed to the upper ends of the front panel  1   a , the service panel  1   m , and the back panel  1   d . Note that a heat insulating material (not illustrated) is attached to a portion corresponding to the electrical component box  60  on the rear side of the top plate  1   n.    
     Next, a configuration of the electrical component box  60  is described. As illustrated in  FIG. 4  to  FIG. 8 , a basic structure of the electrical component box  60  is formed of a front plate  63 , an arm  64 , and a support post  65  in addition to the upper partition plate  61  and the box base plate  62 . 
     The upper partition plate  61  is made of a steel plate, and is provided with an attachment part  610  that is formed on a straight line defined by connecting a joint part between the front panel  1   a  and the lower partition plate  50  to the vicinity of the piping outlet of the heat exchanger  30 , in consideration of ventilation efficiency. A first front bent part  611  and a second front bent part  612  that are bent in two steps are formed at the front-side side end of the attachment part  610 . Specifically, the first front bent part  611  is bent at an obtuse angle to the attachment part  610 , and the second front bent part  612  is formed by further bending the leading end of the first front bent part  611  at an obtuse angle to the first front bent part  611  so as to be substantially parallel to the front surface of the outdoor unit  1 . The leading end of the second front bent part  612  is bent at a substantially right angle toward the back side, whereby a front flange  616  is formed. A back bent part  613  bent at an obtuse angle to the attachment part  610  is formed at the back-side side end of the attachment part  610 . The side end of the back bent part  613  is bent toward the back side, whereby a back flange  617  is formed. An upper flange  614  that is bent at a substantially right angle toward the inside of the electrical component box  60  is formed at the upper ends of the attachment part  610 , the first front bent part  611 , and the back bent part  613 . A lower flange  615  that is bent at a substantially right angle toward the inside of the electrical component box  60  is formed at the lower ends of the attachment part  610 , the first front bent part  611 , and the back bent part  613 . 
     As illustrated in  FIG. 4  and  FIG. 7A , a ventilation hole  61   d  formed of a plurality of circular holes is opened in an upper portion of the attachment part  610 . A water blocking member  80  including a water blocking cover  81  and an inner partition plate  82  is attached to the upper portion of the attachment part  610  on the blower chamber  10  side so as to cover the ventilation hole  61   d . As illustrated in  FIG. 4 , a rectangular heat sink hole  61   b  is opened in the center of the attachment part  610 . As illustrated in  FIG. 4  and  FIG. 5 , a heat sink  77  is attached to the heat sink hole  61   b  with the intermediation of a heat sink mount  78  made of a resin material such that a fin part of the heat sink  77  protrudes in the blower chamber  10 . As illustrated in  FIG. 7A , an inverter board  70  and a power module  74  are attached to the back side of the heat sink  77 . A reactor  75  is attached thereto above the power module  74 . The inverter board  70 , the power module  74 , and the reactor  75  constitute part of a power supply circuit, and heat generated by a heater element (not illustrated) mounted on the inverter board  70  and by the power module  74  during the operation of the power supply is transferred to the heat sink  77  to be released. 
     The second front bent part  612  is provided with a bead  61   a  in the top-bottom direction in order to obtain mechanical strength. As illustrated in  FIG. 8 , hinge slits  61   c  having a predetermined shape are provided with a vertical interval therebetween in a joint part between the second front bent part  612  and the front flange  616 . An insertion piece slit  61   h  is provided on the upper side (on the upper hinge slit  61   c  side) with respect to the middle between the upper and lower hinge slits  61   c.    
     As illustrated in  FIG. 7A , a hook engagement part  618  is provided at part of the upper end of the back bent part  613 , and the hook engagement part  618  is formed by cutting out the upper flange  614  at a predetermined size from the back flange  617  toward the blower chamber  10 . An upper screw hole  61   e  is provided in an upper portion of the back bent part  613 . 
     Insertion pieces  61   g  are provided in front and back portions of the lower flange  615  provided at the lower end of the attachment part  610  so as to protrude downward. A bottom screw hole  61   f  is provided in the lower flange  615  provided below the back bent part  613 . 
     As illustrated in  FIG. 7A , the box base plate  62  is made of a polygonal steel plate, and has a blower chamber  10  side that is shaped so as to be engaged with the upper end part of the lower partition plate  50 . A flange  62   a  bent downward is formed in the periphery of the box base plate  62 . A first ventilation hole  62   b , a second ventilation hole  62   c , and a third ventilation hole  62   d  each formed of a plurality of circular holes are opened in the box base plate  62 . The first ventilation hole  62   b  is provided near immediately below the inverter board  70  and at a position separated from the ventilation hole  61   d  of the upper partition plate  61 . The second ventilation hole  62   c  is provided near immediately below the power module  74  and at a position separated from the ventilation hole  61   d  of the upper partition plate  61 . The third ventilation hole  62   d  is provided immediately below a filter board  71  of the front plate  63  and at a position separated from the ventilation hole  61   d  of the upper partition plate  61 . In addition, two first slits  62   e  are provided in the vicinity of the first ventilation hole  62   b  and the second ventilation hole  62   c  so as to correspond the shape and position of the insertion pieces  61   g  of the upper partition plate  61 . A second slit  62   f   1  and a third slit  62   f   2  are provided in substantially the center of the front-back direction near the right end of the box base plate  62  so as to respectively correspond the shapes and positions of a second insertion piece  65   e  and a third insertion piece  65   f  of the support post  65  to be described later. A base screw hole  62   j  is provided in substantially the center of the left-right direction near the back end of the box base plate  62  so as to correspond to the position of the bottom screw hole  61   f  of the upper partition plate  61 . A portion of the flange  62   a  corresponding to the base screw hole  62   j  is cut out to be formed into a cut-out part  62   k . A side screw hole  62   h  is provided in substantially the center of the left-right direction of the flange  62   a  at the right end of the box base plate  62 . As illustrated in  FIG. 5 , a capacitor board  73  on which a plurality of capacitors  76  are mounted is attached to substantially the center of the box base plate  62 . The capacitor board  73  is placed so as not to block the first ventilation hole  62   b , the second ventilation hole  62   c , and the third ventilation hole  62   d.    
     As illustrated in  FIG. 8 , the front plate  63  is made of a steel plate, and includes an attachment part  630  that forms the front side of the electrical component box  60 . A side face part  631  that is bent at a substantially right angle toward the front side is formed at the left end of the attachment part  630 . The leading end of the side face part  631  is bent at a substantially right angle toward the left side, whereby a left end flange  632  is formed. The right end of the attachment part  630  is bent at a substantially right angle toward the back side, whereby a bent part  634  is formed. The leading end of the bent part  634  is bent at a substantially right angle toward the right side, whereby a right end flange  635  is formed. In addition, an upper flange  633  that is bent at a substantially right angle toward the front side of the electrical component box  60  is formed at the upper end of the attachment part  630 . 
     A fixing part  63   e  is provided in a right-end upper portion of the attachment part  630 , and the fixing part  63   e  is formed by cutting part of the bent part  634  and processing the part so as to protrude toward the right side. The fixing part  63   e  is provided with a screw hole  63   c  and a slit  63   f  for fixing a front plate cover  67  to be described later. In addition, the filter board  71  that removes noise entering from a commercial power supply and the like is attached to an upper portion on the rear side of the attachment part  630  (on the inner side of the electrical component box  60 ). As illustrated in  FIG. 4 , a control board  72  that controls the operation of the outdoor unit  1  is attached to a front-side upper portion of the attachment part  630 , and a terminal part  79  formed of a terminal mount (not illustrated) and a terminal mount cover  79   a  covering the terminal mount is attached to a front-side lower right portion of the attachment part  630 . A display board  90  that displays the operation state of the outdoor unit  1  is further attached to a front-side lower left portion of the attachment part  630 . 
     As illustrated in  FIG. 8 , the left end flange  632  is provided with two upper and lower hinge pieces  63   a , and the hinge pieces  63   a  are placed at positions respectively corresponding to the hinge slits  61   c  of the upper partition plate  61  so as to protrude toward the left side. Each hinge piece  63   a  is provided with a bead  63   d  in order to increase mechanical strength of the hinge piece  63   a , and the bead  63   d  extends from the side face part  631  to the hinge piece  63   a  so as to protrude toward the front side. 
     An insertion piece  63   b  is provided in a right portion of the upper flange  633 , and the insertion piece  63   b  is formed by cutting part of the upper flange  633  so as to protrude toward the back side. 
     As illustrated in  FIG. 8 , the front plate cover  67  is made of a steel plate, and a front part  67   a  is formed therein so as to cover the control board  72  attached to the attachment part  630  of the front plate  63 . A side part  67   b  that is bent at a substantially right angle toward the back side is formed at the right end of the front part  67   a.    
     A first insertion piece  67   d  corresponding to the insertion piece slit  61   h  of the upper partition plate  61  is provided in substantially the center of the top-bottom direction at the left end of the front part  67   a . A substantially cross-shaped bead  67   c  for obtaining mechanical strength is provided at the root of the first insertion piece  67   d  so as to protrude toward the front side. Part of the horizontal portion of the bead  67   c  runs on the first insertion piece  67   d.    
     In addition, a second insertion piece  67   g  engaged with the slit  63   f  of the front plate  63  is provided at the leading end of the side part  67   b  so as to protrude toward the back side. A fixing piece  67   e  including a screw hole  67   f  is formed by bending below the second insertion piece  67   g  so as to follow the fixing part  63   e  of the front plate  63 . 
     As illustrated in  FIG. 5 , the arm  64  is formed by bending an elongated steel plate into a substantially L-shape with a significantly rounded corner as viewed from the top. A right arm part  64   a  is placed in a portion corresponding to the right side of the electrical component box  60  with respect to a circular arc-shaped bent part  64   c . A back arm part  64   b  is placed in a portion corresponding to the back side of the electrical component box  60  with respect thereto. Flanges that are bent at a substantially right angle toward the inside of the electrical component box  60  are respectively provided at the upper and lower ends of the right arm part  64   a  and the back arm part  64   b , whereby mechanical strength is ensured. Beads are respectively provided on outer surfaces of the right arm part  64   a , the back arm part  64   b , and the bent part  64   c , whereby mechanical strength is similarly ensured. 
     As illustrated in  FIG. 4 , an abutment surface  64   d  that is bent at a substantially right angle toward the inside of the electrical component box  60  is formed at the leading end of the right arm part  64   a . A first insertion hole  64   e  engaged with the insertion piece  63   b  of the front plate  63  is provided in the abutment surface  64   d  of the right arm part  64   a . A second insertion hole  64   f  engaged with a first insertion piece  65   d  of the support post  65  to be described later is provided in substantially the center of the front-back direction at the lower end of the right arm part  64   a . A screw hole  64   h  is provided above the second insertion hole  64   f  in the outer surface of the right arm part  64   a.    
     As illustrated in  FIG. 5 , a hook  64   g  bent into a substantially L-shape is provided in an upper portion on the left side (blower chamber  10  side) of the back arm part  64   b.    
     As illustrated in  FIG. 4  and  FIG. 5 , the support post  65  is made of a steel plate formed into a U-shape in cross-section, and includes: a front part  65   a  on the front side of the electrical component box  60 ; a left part  65   b  on the inner side of the electrical component box  60 ; and a right part  65   c  on the outer side of the electrical component box  60 . The left part  65   b  and the right part  65   c  are formed by bending the respective end parts of the front part  65   a  at a substantially right angle toward the back side of the electrical component box  60 . 
     As illustrated in  FIG. 7A , the upper end of the front part  65   a  is bent toward the back side of the electrical component box  60 , whereby a receiving part  65   j  that receives the right arm part  64   a  of the arm  64  is formed. The third insertion piece  65   f  engaged with the third slit  62   f   2  of the box base plate  62  is formed at the lower end of the front part  65   a.    
     The second insertion piece  65   e  engaged with the second slit  62   f   1  of the box base plate  62  is formed at the lower end of the left part  65   b . The upper end of the right part  65   c  is longer than those of the front part  65   a  and the left part  65   b . The upper end of the right part  65   c  is formed as the first insertion piece  65   d  engaged with the second insertion hole  64   f  of the arm  64  illustrated in  FIG. 4 , and an upper screw hole  65   g  is provided in the first insertion piece  65   d . Further, a lower screw hole  65   h  is provided in a lower portion of the right part  65   c.    
     Next, with reference to  FIG. 4  to  FIG. 9 , description is given of how to assemble the electrical component box  60  having the configuration described above and how to join the electrical component box  60  to above the machinery chamber  11 . First, as illustrated in  FIG. 7A , the inner partition plate  82  and the water blocking cover  81  are attached in the stated order from the outer side (blower chamber  10  side) of the upper partition plate  61  so as to cover the ventilation hole  61   d . Next, the heat sink mount  78  to which the heat sink  77  is attached is attached to the heat sink hole  61   b  provided in the attachment part  610  of the upper partition plate  61  illustrated in  FIG. 4  such that the fin part of the heat sink  77  protrudes toward the blower chamber  10 . The reactor  75  is attached to the inner side of the attachment part  610  (the inner side of the electrical component box  60 ), and the inverter board  70  and the power module  74  are attached to the rear side of the heat sink  77 . 
     Next, a seal material  300  is attached to each of the upper flange  614  and the lower flange  615  of the upper partition plate  61 . Then, the insertion pieces  61   g  of the upper partition plate  61  are respectively inserted into the first slits  62   e  of the box base plate  62  to be positioned. After that, the bottom screw hole  61   f  of the upper partition plate  61  is fixed with a screw to the base screw hole  62   j  of the box base plate  62 . 
     Next, the support post  65  is joined to the arm  64 . The first insertion piece  65   d  of the support post  65  is inserted into the second insertion hole  64   f  of the arm  64  illustrated in  FIG. 4 , whereby the lower end flange of the right arm part  64   a  is brought into contact with the receiving part  65   j  of the support post  65 . After that, the upper screw hole  65   g  of the support post  65  is fixed with a screw to the screw hole  64   h  of the arm  64 . 
     Next, the structure obtained by joining the support post  65  to the arm  64  is joined to the upper partition plate  61  and the box base plate  62  illustrated in  FIG. 5  on which the capacitor board  73  having the capacitors  76  thereon is mounted. First, the hook  64   g  of the arm  64  is engaged with the hook engagement part  618  provided in the back bent part  613  of the upper partition plate  61 . Then, the upper screw hole  61   e  of the upper partition plate  61  is fixed with a screw to a screw hole (not illustrated) of the back arm part  64   b . The second insertion piece  65   e  of the support post  65  is inserted into the second slit  62   f   1  of the box base plate  62 , and the third insertion piece  65   f  thereof is inserted into the third slit  62   f   2  of the box base plate  62 . Then, the lower screw hole  65   h  of the support post  65  is fixed with a screw to the side screw hole  62   h  of the box base plate  62 . 
     Next, the control board  72 , the terminal part  79 , and the display board  90  illustrated in  FIG. 4  are attached to the front side of the attachment part  630  of the front plate  63 . As illustrated in  FIG. 7A , the filter board  71  is attached to the rear side of the attachment part  630  (the inner side of the electrical component box  60 ). Then, the front plate  63  is joined to the structure obtained by combining the upper partition plate  61 , the box base plate  62 , the arm  64 , and the support post  65 . First, the hinge pieces  63   a  of the front plate  63  illustrated in  FIG. 8  are respectively inserted into the hinge slits  61   c  of the upper partition plate  61 . Next, the insertion piece  63   b  of the front plate  63  is inserted into the first insertion hole  64   e  of the arm  64  illustrated in  FIG. 4 , and a lower portion of the front plate  63  is screwed to the front side of the box base plate  62 . 
     Lastly, the front plate cover  67  is joined to the front plate  63 . As illustrated in  FIG. 7A , the first insertion piece  67   d  of the front plate cover  67  is inserted into the insertion piece slit  61   h  of the upper partition plate  61 . Next, the second insertion piece  67   g  of the front plate cover  67  is inserted into the slit  63   f  provided in the fixing part  63   e  of the front plate  63 . After that, the fixing piece  67   e  of the front plate cover  67  is brought into contact with the fixing part  63   e  of the front plate  63 , and the screw hole  67   f  of the front plate cover  67  is fixed with a screw to the screw hole  63   c  of the front plate  63 . 
     As has been described above, the electrical component box  60  has the structure in which the upper partition plate  61 , the front plate  63 , and the box base plate  62  are joined to one another and are supported by the arm  64  and the support post  65 . The upper partition plate  61  is provided with the front flange  616  and the back flange  617 , to thereby obtain enhanced mechanical strength. In addition, the box base plate  62  is provided with the flange  62   a , to thereby obtain enhanced mechanical strength, and a surface of the flange  62   a  receives the lower portion of the attachment part  630  of the front plate  63 , whereby joining strength is enhanced. Further, the arm  64  substantially perpendicularly supports the front plate  63  in the front-back direction, and the arm  64  also supports the back bent part  613  of the upper partition plate  61  in the state where the back arm part  64   b  of the arm  64  is flush with the back bent part  613 . Hence, even if the electrical component box  60  receives an impact in the front-back direction and the left-right direction, strength high enough to withstand the impact can be obtained. Furthermore, the upper end parts of the front part  65   a  and the left part  65   b  of the support post  65  abut against the flange provided at the lower end of the right arm part  64   a  of the arm  64 , and the lower end parts of the front part  65   a  and the left part  65   b  of the support post  65  abut against the box base plate  62 . As a result, the support post  65  is perpendicularly joined to the right arm part  64   a  of the arm  64  and the box base plate  62 , to thereby support the right arm part  64   a  of the arm  64  and the box base plate  62  in the top-bottom direction. Hence, even if the electrical component box  60  receives an impact in the top-bottom direction, strength high enough to withstand the impact can be obtained. Accordingly, the amount of used material (steel plate) on the back side and right side of the electrical component box  60  can be reduced. Furthermore, the electrical component box  60  having high strength against an impact applied in three directions (front-back/right-left/top-bottom directions) can be achieved. In addition, because the support post  65  supports the lower end of the right arm part  64   a  of the arm  64  in the top-bottom direction, the arm  64  does not deform downward under its own weight. Accordingly, at the time of attaching the front plate  63 , the insertion piece  63   b  of the front plate  63  can be easily engaged with the first insertion hole  64   e  of the arm  64 . 
     In addition, among the components and apparatuses constituting the power supply circuit, the reactor  75  and the power module  74  having a large amount of heat generation are placed on the upper partition plate  61 , and the capacitors  76  similarly having a large amount of heat generation are installed on the box base plate  62  separately from the reactor  75  and the power module  74 . Hence, the electrical component box  60  can be downsized compared with the case where these components are installed on one member (in the present embodiment, the upper partition plate  61 ) constituting the casing of the electrical component box  60 . 
     Next, with reference to  FIG. 7B  and  FIG. 9 , description is given of how to join the electrical component box  60  to above the machinery chamber  11 . As illustrated in  FIG. 9 , the blower chamber  10  side of the box base plate  62  is shaped so as to be engaged with the upper end part of the lower partition plate  50 . The lower partition plate  50  is provided with the receiving part  50   a  that is formed by bending inward the upper end part of the lower partition plate  50 . At the time of joining the electrical component box  60  to the lower partition plate  50 , the box base plate  62  is set onto the receiving part  50   a  of the lower partition plate  50  along the flange  62   a  of the box base plate  62 , whereby the electrical component box  60  can be positioned. After that, the electrical component box  60  is fixed to the lower partition plate  50  by fastening with a screw, welding, or any other suitable method. 
     Note that, as illustrated in  FIG. 7B , at the time of setting the box base plate  62  onto the lower partition plate  50 , the vicinity of the upper leading end of the second partition plate  50   d  is engaged with the cut-out part  62   k  of the box base plate  62 , and the flange  50   e  protrudes toward the back side from the periphery of the box base plate  62 . 
     In general, the electrical component box is heavy (approximately 10 kg). In addition, at the time of joining the electrical component box to above the machinery chamber, it is necessary to position the electrical component box with respect to the lower partition plate and screw or weld the electrical component box thereto while the electrical component box is held up. For example, in the case where (the upper partition plate of) the electrical component box is put for positioning on a small flange part of the upper surface of the lower partition plate and is screwed or welded thereto, it is necessary to perform the positioning and the screwing or welding while the heavy electrical component box is held up, resulting in decrease in workability. 
     In the present embodiment, such positioning can be achieved only by setting the electrical component box  60  (box base plate  62 ) onto the receiving part  50   a  of the lower partition plate  50  along the flange  62   a  of the box base plate  62 . Accordingly, the positioning work is facilitated, and the fixing work such as screwing or welding after the positioning can be performed more easily, leading to simpler work and enhanced workability. In addition, the electrical component box  60  is joined to above the machinery chamber  11  in the state where the box base plate  62  is fixed to the lower partition plate  50 . Hence, the upper partition plate  61  does not need to be shaped so as to accord with the shape of the lower partition plate  50  (for example, so as to have the same shape as that of the lower partition plate  50 ). Accordingly, the degree of freedom in the shape of the upper partition plate  61  is higher, and, for example, in the case as in the present embodiment where the heavy electrical components such as the power module  74  and the reactor  75  are attached to the upper partition plate  61 , the shape of the upper partition plate  61  can be determined in the following manner. As illustrated in  FIG. 7B , the upper end part of the bent part  50   c  of the lower partition plate  50  supports the lower end parts of the first front bent part  611  and the second front bent part  612  of the upper partition plate  61  with the intermediation of the box base plate  62 , and the upper end part of the second partition part  50   d  of the lower partition plate  50  supports the lower end part of the back bent part  613  of the upper partition plate  61  with the intermediation of the box base plate  62 . With this structure, because the upper partition plate  61  is supported by both the box base plate  62  and the lower partition plate  50 , the heavy upper partition plate  61  can be supported more firmly. Furthermore, the attachment part  610  of the upper partition plate  61  can be formed on the straight line defined by connecting the joint part between the front panel  1   a  and the lower partition plate  50  to the vicinity of the piping outlet on the back side of the heat exchanger  30 , in order to enable the heat sink  77  to efficiently release heat in consideration of ventilation efficiency. 
     Note that, in the state where the electrical component box  60  is joined to above the machinery chamber  11  and where the top plate  1   n  of the outdoor unit  1  is then attached thereon, the upper flange  614  of the upper partition plate  61  abuts against the top plate in with the intermediation of the seal material  300 . In addition, the flanges provided at the upper end parts of the right arm part  64   a  and the back arm part  64   b  of the arm  64  abut against the top plate  1   n  with the intermediation of the heat insulating material (not illustrated). With this structure, the upper partition plate  61  and the arm  64  also serve to reinforce the top plate  1   n . In addition, the vicinity of the piping outlet of the heat exchanger  30  is coupled to the back flange  617  of the upper partition plate  61  and the flange  50   e  of the lower partition plate  50 . Accordingly, the upper partition plate  61 , that is, the electrical component box  60  is integrally fixed to the lower partition plate  50  by the heat exchanger  30 , so that the electrical component box  60  can be fixed more firmly to above the machinery chamber  11 . 
     Next, other effects of the electrical component box  60  of the outdoor unit  1  according to the present embodiment are described. First, with reference to  FIG. 1  to  FIG. 3  and  FIG. 10 , flows of air in the electrical component box  60  and effects thereof are described. As described above, the electrical component box  60  according to the present embodiment is provided with the box base plate  62  including the flange  62   a  in the periphery thereof, in order to obtain strength of the electrical component box  60 . As illustrated in  FIG. 3 , the box base plate  62  is placed between the upper partition plate  61  and the lower partition plate  50 , and hence the box base plate  62  may unfavorably hinder air from flowing into the electrical component box  60 , the air having flown into the machinery chamber  11  from the air intake hole if provided in the back panel  1   d  illustrated in  FIG. 2  by means of the blower fans  20 . In order to solve this problem, the plurality of ventilation holes are opened in the box base plate  62 , and air is taken from the machinery chamber  11  into the electrical component box  60  through the ventilation holes. 
     When the outdoor unit  1  starts operating and the blower fans  20  turn, a difference in air pressure occurs between the inside of the blower chamber  10  of the outdoor unit  1  and the other places (the outside of the outdoor unit  1 , the inside of the machinery chamber  11 , and the inside of the electrical component box  60 ). This difference in air pressure causes air to be suctioned into the blower chamber  10  from the back suction port  1   e  of the outdoor unit  1  and the suction port  1   q  provided on the left side of the outdoor unit  1 . Further, air is suctioned also into the machinery chamber  11  from the air intake hole if provided in the lower portion of the back panel  1   d . Because the difference in air pressure exists between the inside of the blower chamber  10  and the insides of the machinery chamber  11  and the electrical component box  60 , the air that has been suctioned into the machinery chamber  11  from the air intake hole if passes through the inside of the electrical component box  60 , and is discharged into the blower chamber  10  through the ventilation hole  61   d  of the upper partition plate  61 . 
     Specifically, as illustrated in  FIG. 10 , the flow of air from the machinery chamber  11  into the electrical component box  60  is divided into a flow of air Fa and flows of air Fb, Fc, and Fd. The flow of air Fa flows into the electrical component box  60  through open space defined by the upper partition plate  61 , the box base plate  62 , the front plate  63 , and the arm  64 , and the flows of air Fb, Fc, and Fd are separated from the flow of air Fa by the flange  62   a  of the box base plate  62 . The flow of air Fb flows into the electrical component box  60  through the first ventilation hole  62   b . The flow of air Fc flows into the electrical component box  60  through the second ventilation hole  62   c . The flow of air Fd flows into the electrical component box  60  through the third ventilation hole  62   d . The flow of air Fb and the flow of air Fc pass in the vicinity of the inverter board  70 , the power module  74 , and the reactor  75  attached to the upper partition plate  61  while flowing toward the ventilation hole  61   d  of the upper partition plate  61 , and hence these components are cooled by the flow of air Fb and the flow of air Fc. Part of the flow of air Fb and part of the flow of air Fc flow in the vicinity of the capacitors  76 , and hence the capacitors  76  are also cooled by the flow of air Fb and the flow of air Fc. The flow of air Fd passes in the vicinity of the filter board  71  while flowing toward the ventilation hole  61   d  of the upper partition plate  61 , and hence the filter board  71  is cooled by the flow of air Fd. The flows of air Fb, Fc, and Fd join the flow of air Fa that wholly cools the inside of the electrical component box  60  to become a flow of discharged air F, and the flow of discharged air F is discharged into the blower chamber  10  through the ventilation hole  61   d  of the upper partition plate  61  and the water blocking member  80 . 
     As has been described above, in the electrical component box  60 , generated are the two types of flows of air: the flows of air Fb, Fc, and Fd that directly touch the board on which the heater element is mounted and the components and apparatuses having a large amount of heat generation; and the flow of air Fa that wholly cools the inside of the electrical component box  60 . In the case where the electrical component box  60  is not provided with the box base plate  62 , the air flowing from the machinery chamber  11  into the electrical component box  60  flows evenly through the electrical component box  60 , and hence the air evenly cools the boards and the electrical components housed in the electrical component box  60  regardless of the amount of heat generation. In contrast to this, in the electrical component box  60  according to the present embodiment, the flange  62   a  is provided in the periphery of the box base plate  62  such that the air selectively touches the board on which the element having a large amount of heat generation is mounted and the electrical components having a large amount of heat generation. Further, the ventilation holes are opened at a plurality of positions of the box base plate  62  so as to correspond to these board and electrical components. Accordingly, the board on which the heater element is mounted and the components and apparatuses having a large amount of heat generation, which are housed in the electrical component box  60 , can be effectively cooled, and hence the heat release effect can be enhanced. 
     Next, with reference to  FIG. 11  to  FIG. 14 , the water blocking member  80  that covers the ventilation hole  61   d  of the upper partition plate  61  is described. As illustrated in  FIG. 11 , the water blocking member  80  includes the water blocking cover  81  and the inner partition plate  82 . The water blocking member  80  guides the air discharged from the ventilation hole  61   d  of the upper partition plate  61  into the blower chamber  10 , and also prevents water droplets from entering the electrical component box  60  through the ventilation hole  61   d  of the upper partition plate  61 , the water droplets resulting from the turning of the blower fans  20 . 
     As illustrated in  FIG. 11 , the water blocking cover  81  is made of a steel plate, and a ventilation part  81   a  is formed on a surface thereof facing the blower chamber  10 . A top face part  81   b  that is bent at a substantially right angle toward the electrical component box  60  is formed at the upper end of the ventilation part  81   a . A bottom face part  81   c  that is bent at a substantially right angle toward the electrical component box  60  is formed at the lower end of the ventilation part  81   a . A front side-face part  81   d  that is bent at a substantially right angle toward the electrical component box  60  is formed at the front-side side end of the ventilation part  81   a . A back side-face part  81   e  that is bent at a substantially right angle toward the electrical component box  60  is formed at the back-side side end of the ventilation part  81   a.    
     As illustrated in  FIG. 11  and  FIG. 14 , the ventilation part  81   a  is provided with a plurality of slit-like ventilation ports  81   m  with eaves, and as illustrated in  FIG. 14 , the ventilation ports  81   m  are opened downward with upper portions thereof being covered by the eaves. 
     As illustrated in  FIG. 11 , an upper bent part  81   f  that is bent upward at a substantially right angle is formed at the leading end of the top face part  81   b . A flange  81   k  that is bent at a substantially right angle toward the electrical component box  60  is formed at the leading end of the upper bent part  81   f . The top face part  81   b  is provided with an extending part  81   n  that is formed by extending part of the top face part  81   b  toward the back side so as to cover the upper end of the back side-face part  81   e.    
     As illustrated in  FIG. 13  and  FIG. 14 , a front bent part  81   h  that is bent at a substantially right angle toward the front side is formed at the leading end of the front side-face part  81   d . A back bent part  81   j  that is bent at a substantially right angle toward the back side is formed at the leading end of the back side-face part  81   e . A lower bent part  81   g  that is bent downward at a substantially right angle is formed at the leading end of the bottom face part  81   c.    
     As illustrated in  FIG. 11 ,  FIG. 13 , and  FIG. 14 , the inner partition plate  82  is made of a steel plate, and an inner partition part  82   a  is formed on a plane substantially parallel to the ventilation part  81   a  of the water blocking cover  81  and the attachment part  610  of the upper partition plate  61 . An upper bent part  82   b  that is bent at a substantially right angle toward the electrical component box  60  is formed at the upper end of the inner partition part  82   a . A lower bent part  82   c  that is bent at a substantially right angle toward the electrical component box  60  is formed at the lower end of the inner partition part  82   a . A side part  82   d  that is bent at a substantially right angle toward the electrical component box  60  is formed at the front-side side end of the inner partition part  82   a . A side flange  82   e  that is bent at a substantially right angle toward the front side is formed at the leading end of the side part  82   d . A bent part  82   f  bent toward the blower chamber  10  is formed at the back-side side end of the inner partition part  82   a.    
     As illustrated in  FIG. 13 , the length of the inner partition part  82   a  in the front-back direction is smaller than the internal length of the water blocking cover  81  in the front-back direction (the distance between the inner surface of the front side-face part  81   d  and the inner surface of the back side-face part  81   e  of the water blocking cover  81 ). As illustrated in  FIG. 14 , the height of the inner partition plate  82  (the distance between the outer surface of the upper bent part  82   b  and the outer surface of the lower bent part  82   c ) is substantially the same as the internal length of the water blocking cover  81  in the top-bottom direction (the distance between the inner surface of the top face part  81   b  and the inner surface of the bottom face part  81   c  of the water blocking cover  81 ). 
     As illustrated in  FIG. 11 , the inner partition plate  82  and the water blocking cover  81  are attached to the upper partition plate  61 . The inner partition plate  82  is first welded to the attachment part  610  of the upper partition plate  61 , and the water blocking cover  81  is then welded to the attachment part  610  of the upper partition plate  61 . As illustrated in  FIG. 12  and  FIG. 14 , at the time of welding the water blocking cover  81  to the upper partition plate  61 , the flange  81   k  of the water blocking cover  81  is fitted to the upper flange  614  of the upper partition plate  61 , whereby the positioning of the water blocking cover  81  is facilitated. Accordingly, the work of welding the water blocking cover  81  to the upper partition plate  61  can be simple, and the workability is enhanced. In addition, even if water droplets on the rear side of the top plate  1   n  fall onto the upper flange  614  of the upper partition plate  61 , the flange  81   k  of the water blocking cover  81  can prevent the water droplets from entering the water blocking member  80 . Eventually, the flange  81   k  can prevent the water droplets from entering the electrical component box  60 . Note that, although steps are caused on the upper flange  614  by fitting the flange  81   k  of the water blocking cover  81  to the upper flange  614  of the upper partition plate  61 , the seal material  300  is attached to the upper flange  614  as illustrated in  FIG. 11 , and the seal material  300  elastically deforms at the time of placing the top plate  1   n  thereon, to thereby absorb the steps on the upper flange  614 , so that the inside of the structure is sealed. 
     Next, with reference to  FIG. 13  and  FIG. 14 , description is given of a flow of air F (which is the same as the flow of discharged air F in  FIG. 7A ) that is suctioned from the inside of the electrical component box  60  through the ventilation hole  61   d  of the upper partition plate  61 , passes around the inner partition plate  82 , and is discharged into the blower chamber  10  from the ventilation ports  81   m  of the water blocking cover  81 . As illustrated in  FIG. 13 , an inner portion of the water blocking member  80  on the front side of the outdoor unit  1  is blocked by the side part  82   d  and the side flange  82   e  of the inner partition plate  82 . Similarly, as illustrated in  FIG. 14 , upper and lower inner portions of the water blocking member  80  are respectively blocked by the upper bent part  82   b  and the lower bent part  82   c  of the inner partition plate  82 . In addition, space is formed between the back side-face part  81   e  of the water blocking cover  81  and the bent part  82   f  of the inner partition plate  82 , in an inner portion of the water blocking member  80  on the back side of the outdoor unit  1 . This space serves as the air flow passage. As indicated by arrows F in  FIG. 13  and  FIG. 14 , the air that has been suctioned from the ventilation hole  61   d  of the upper partition plate  61  hits against the inner partition part  82   a  of the inner partition plate  82 , and flows toward the air flow passage formed between the back side-face part  81   e  of the water blocking cover  81  and the bent part  82   f  of the inner partition plate  82 . The air that has passed through the air flow passage and flown around the inner partition part  82   a  to reach the ventilation part  81   a  of the water blocking cover  81  is discharged into the blower chamber  10  from the ventilation ports  81   m  of the ventilation part  81   a.    
     The front side-face part  81   d  and the back side-face part  81   e  of the water blocking cover  81  are formed by bending the respective side ends of the ventilation part  81   a , and a slight gap may occur between the two side-face parts and the ventilation part  81   a . As illustrated in  FIG. 13 , the air flow passage is formed between the back side-face part  81   e  of the water blocking cover  81  and the bent part  82   f  of the inner partition plate  82  in the back-side inner portion of the water blocking member  80 , and hence this back-side inner portion is not blocked by the inner partition plate  82  unlike the other portions inside of the water blocking member  80 . Accordingly, if water droplets are attached to the back side of the top face part  81   b  of the water blocking cover  81 , the water droplets may enter the water blocking member  80  from the above-mentioned gap occurring between the back side-face part  81   e  and the ventilation part  81   a . In order to prevent this, the extending part  81   n  that protrudes from the top face part  81   b  toward the back side of the outdoor unit  1  is provided so as to cover the gap occurring between the back side-face part  81   e  and the ventilation part  81   a . The extending part  81   n  can prevent water droplets from entering the water blocking member  80  from the gap occurring between the back side-face part  81   e  and the ventilation part  81   a , and eventually can prevent the water droplets from entering the electrical component box  60 . 
     In the water blocking cover  81  described above, the extending part  81   n  is formed by extending part of the top face part  81   b  toward the back side. Alternatively, if the air flow passage is formed by the inner partition plate  82  in a front-side inner portion of the water blocking cover  81 , the extending part  81   n  may be formed by extending part of the top face part  81   b  toward the front side. Still alternatively, if the air flow passage is formed by the inner partition plate  82  in a top-side inner portion of the water blocking cover  81 , the extending part  81   n  may be formed by extending part of the top face part  81   b  toward both the front side and the back side. 
     Next, with reference to  FIG. 8  and  FIG. 15  to  FIG. 17 , description is given of how to attach the front plate  63  and the front plate cover  67  to the upper partition plate  61  and effects thereof. Note that, in  FIG. 8  and  FIG. 15  to  FIG. 17 , the boards, components, and apparatuses attached to the front plate  63  and the upper partition plate  61  are omitted. As illustrated in  FIG. 8  and  FIG. 15 , at the time of attaching the front plate  63  to the upper partition plate  61 , first, the hinge pieces  63   a  provided on the left side of the front plate  63  are respectively engaged with the hinge slits  61   c  of the upper partition plate  61 . As illustrated in FIG.  15 B, first, each hinge piece  63   a  is inserted into each hinge slit  61   c  in the lateral direction of the hinge slit  61   c . Next, the front plate  63  is slid downward, whereby an engagement part  63   j  of the hinge piece  63   a  is engaged with the front flange  616  of the upper partition plate  61 . After that, as described with reference to  FIG. 7A , the lower portion of the front plate  63  is screwed to the front side of the box base plate  62 . 
     The horizontal width of the hinge slit  61   c  of the upper partition plate  61  is set to be slightly larger (for example, 0.2 mm) than the thickness of the hinge piece  63   a  (the total value of the height of the bead  63   d  and the thickness of the hinge piece  63   a ). With such setting, as illustrated in  FIG. 16 , if the screw that fixes the front plate  63  to the box base plate  62  is removed, the front plate  63  can be rotated in a direction indicated by an arrow R with respect to the insertion parts of the hinge pieces  63   a  into the hinge slits  61   c.    
     At the time of replacing or repairing the boards, components, and apparatuses in the electrical component box  60  during maintenance work of the outdoor unit  1 , a worker detaches the service panel  1   m  of the outdoor unit  1 , and removes the screw that fixes the front plate  63  to the box base plate  62 . Then, the worker detaches the front plate cover  67 , and rotates the front plate  63  toward the near side, whereby the worker can perform internal work of the electrical component box  60 . Accordingly, the workability during maintenance is enhanced. 
     As illustrated in  FIG. 17 , after the front plate  63  is attached to the upper partition plate  61  and the box base plate  62 , the front plate cover  67  is attached to the upper partition plate  61  and the front plate  63 . The first insertion piece  67   d  of the front plate cover  67  is inserted into the insertion piece slit  61   h  of the upper partition plate  61 . After that, the fixing piece  67   e  of the front plate cover  67  is brought into contact with the fixing part  63   e  of the front plate  63 , and the screw hole  67   f  of the front plate cover  67  is fixed with the screw to the screw hole  63   c  of the front plate  63 . 
     In the front part  67   a  of the front plate cover  67 , the length between the insertion piece  67   d  and the upper end part of the front part  67   a  and the length of the front part  67   a  in the left-right direction are set such that the rear surface of an upper left portion of the front part  67   a  covers part of the bead  63   d  provided on the upper hinge piece  63   a  of the front plate  63  when the front plate cover  67  is attached to the upper partition plate  61  and the front plate  63 . Accordingly, when the first insertion piece  67   d  of the front plate cover  67  is inserted into the insertion piece slit  61   h  of the front plate  63 , (the rear surface of the upper left portion of) the front part  67   a  of the front plate cover  67  comes into contact with (runs on) the bead  63   d  of the upper hinge piece  63   a . At this time, the length and the thickness (the total value of the height of the bead  67   c  and the thickness of the first insertion piece  67   d ) of the first insertion piece  67   d  are determined such that the bead  67   c  of the first insertion piece  67   d  comes into contact with the rear surface of the second front bent part  612  of the upper partition plate  61 . Accordingly, when the front plate cover  67  is attached to the upper partition plate  61  and the front plate  63 , the bead  67   c  of the first insertion piece  67   d  comes into contact with the rear surface of the second front bent part  612  of the upper partition plate  61 , and the front part  67   a  comes into contact with the bead  63   d  provided on the upper hinge piece  63   a  of the front plate  63 , whereby the front plate  63  and the front plate cover  67  push each other. Note that, in such an attachment state of the front plate cover  67  as described above, the upper-end left side (the portion in contact with the bead  63   d ) of the front part  67   a  of the front plate cover  67  may warp toward the front side, but the bead  67   c  is provided also in the top-bottom direction on the front part  67   a , and hence the warpage of the upper-end left side of the front part  67   a  can be suppressed. 
     Because the horizontal width of each hinge slit  61   c  of the upper partition plate  61  is set to be slightly larger than the thickness of each hinge piece  63   a  of the front plate  63 , a slight gap exists between the hinge slit  61   c  and the hinge piece  63   a . In the case where the front plate  63  and the upper partition plate  61  vibrate due to vibration of the compressor provided in the machinery chamber  11  during the operation of the outdoor unit  1 , the hinge slits  61   c  and the hinge pieces  63   a  may hit against each other due to the vibration to thereby cause noise (hitting sound). In order to solve this, the front plate cover  67  is attached to the front plate  63 , whereby the front plate  63  and the front plate cover  67  push each other. Hence, even if the front plate  63  and the upper partition plate  61  vibrate, the hinge slits  61   c  and the hinge pieces  63   a  do not hit against each other, and the noise caused by the hitting can be suppressed from occurring. In addition, because the front plate cover  67  is pushed by the front plate  63 , the front plate cover  67  can be suppressed from vibrating.