Patent Publication Number: US-11384581-B2

Title: Door opening/closing apparatus and hinge

Description:
This application is the U.S. national phase of International Application No. PCT/JP2019/039266 filed Oct. 4, 2019 which designated the U.S. and claims priority to JP Patent Application No. 2018-198999 filed Oct. 23, 2018, the entire contents of each of which are hereby incorporated by reference. 
     TECHNICAL FIELD 
     The present invention relates to a door opening/closing apparatus and hinge that causes a door to move parallel to itself between a closed position and an open position. 
     BACKGROUND ART 
     The applicants have proposed a door opening/closing apparatus illustrated in  FIG. 11  as this type of door opening/closing apparatus (refer to Patent Literature 1). The door opening/closing apparatus includes a pair of hinges  51   a  and  51   b , and a connecting bar  52  that is connected to the pair of hinges  51   a  and  51   b.    
     As illustrated in  FIGS. 12A and 12B , the hinges  51   a  and  51   b  each include a main body-side member  55  that is mounted on an inner surface of a main body  53 , a door-side member  56  that is mounted on the back of a door  54 , a main arm  58  that is pivotably connected to the main body-side member  55  and the door-side member  56 , a first link  57  that is pivotably connected to the main body-side member  55  and the door-side member  56 , and a second link  59  that is pivotably connected to the main body-side member  55  and the door-side member  56 . Three first shafts  58   a ,  57   a , and  59   a  about which the main arm  58 , the first link  57 , and the second link  59  pivot relative to the main body-side member  55  are placed on the vertices of a triangle in axial view. Similarly, three second shafts  58   b ,  57   b , and  59   b  about which the main arm  58 , the first link  57 , and the second link  59  pivot relative to the door-side member  56  are placed on the vertices of a triangle in axial view. 
     The main body-side member  55 , the door-side member  56 , the main arm  58 , and the first link  57  configure a parallel linkage mechanism (also called a parallel crank mechanism) in terms of mechanics. Hence, the door  54  moves parallel to itself between a closed position and an open position. However, if only the main body-side member  55 , the door-side member  56 , the main arm  58 , and the first link  57  are used, a change point may occur with the closing and opening of the door  54 , and the mechanism becomes unstable. Hence, the second link  59  is added to prevent the mechanism from becoming unstable. 
     As illustrated in  FIG. 12B , the main arm  58  includes a bent portion  58   c  to prevent the main arm  58  from interfering with the main body  53  and interfering with an unillustrated neighboring door in the open position of the door  54 . 
     As illustrated in  FIG. 11 , the connecting bar  52  is connected to the main arms  58  of the pair of hinges  51   a  and  51   b , which causes the pair of hinges  51   a  and  51   b  to work in an interlocked fashion and causes the door  54  to stably open and close even if the door  54  is heavy. 
     CITATION LIST 
     Patent Literature 
     
         
         Patent Literature 1: Japanese Patent No. 5291810 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     As illustrated in  FIG. 11 , however, the connecting bar  52  is mounted on the main body  53  side of the main arm  58  and near the bent portion  58   c  of the main arm  58  in the known door opening/closing apparatus. The connecting bar  52  runs from the top to bottom of the main body  53 . Accordingly, there is a problem that the connecting bar  52  interferes with storage, which results in a reduction in storage space in the main body  53 . 
     The present invention has been made considering the above problem, and an object thereof is to provide a door opening/closing apparatus that can expand storage space in a main body. 
     Solution to Problem 
     In order to solve the above problem, one aspect of the present invention is a door opening/closing apparatus including: at least two hinges; and a connecting bar configured to be connected to the at least two hinges, in which each hinge has: a main body-side member configured to be mounted on an inner surface of a main body; a door-side member configured to be mounted on the back of a door; a main arm configured to be pivotably connected to the main body-side member and the door-side member; a first link configured to be pivotably connected to the main body-side member and the door-side member; and a second link configured to be pivotably connected to the main body-side member and the door-side member, three first shafts about which the main arm, the first link, and the second link pivot relative to the main body-side member are placed on vertices of a triangle in axial view, three second shafts about which the main arm, the first link, and the second link pivot relative to the door-side member are placed on vertices of a triangle in the axial view, the main arm has a bent portion, the door opening/closing apparatus causes the door to move parallel to itself between a closed position and an open position, the connecting bar is mounted on a door side of the main arm, and the center of the connecting bar in a width direction thereof is placed on the second shaft side relative to the center between the first shaft of the main arm and the second shaft of the main arm in a front view of the door in a state where the door is in the closed position. 
     Another aspect of the present invention is a hinge including: a main body-side member configured to be mounted on an inner surface of a main body; a door-side member configured to be mounted on the back of a door; a main arm configured to be pivotably connected to the main body-side member and the door-side member; a first link configured to be pivotably connected to the main body-side member and the door-side member; and a second link configured to be pivotably connected to the main body-side member and the door-side member, in which three first shafts about which the main arm, the first link, and the second link pivot relative to the main body-side member are placed on vertices of a triangle in axial view, three second shafts about which the main arm, the first link, and the second link pivot relative to the door-side member are placed on vertices of a triangle in the axial view, the main arm has a bent portion, the hinge causes the door to move parallel to itself between a closed position and an open position, a mounting portion of the main arm on which a connecting bar is mounted is placed on a door side of the main arm, and the center of the mounting portion in a width direction thereof is placed on the second shaft side relative to the center between the first shaft of the main arm and the second shaft of the main arm in a front view of the door in a state where the door is in the closed position. 
     Advantageous Effects of Invention 
     According to the present invention, a connecting bar can be put closer to the back of a door in a closed position. Hence, storage space in a main body can be expanded. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIGS. 1A to 1C  are perspective views of a front side of a cabinet using a door opening/closing apparatus of one embodiment of the present invention ( FIG. 1A  illustrates a closed position of a door,  FIG. 1B  illustrates a midpoint position of the door, and  FIG. 1C  illustrates an open position of the door). 
         FIGS. 2A to 2C  are perspective views of a back side of the cabinet ( FIG. 2A  illustrates the closed position of the door,  FIG. 2B  illustrates the midpoint position of the door, and  FIG. 2C  illustrates the open position of the door). 
         FIGS. 3A and 3B  are perspective views of a hinge of the embodiment ( FIG. 3A  illustrates a perspective view of the hinge as viewed from a main body side, and  FIG. 3B  illustrates a perspective view of the hinge as viewed from the door side). 
         FIG. 4  is an exploded perspective view of the hinge of the embodiment. 
         FIGS. 5A and 5B  are perspective views of a main arm of the embodiment ( FIG. 5A  illustrates a state where an assist arm has been incorporated into an arm body, and  FIG. 5B  illustrates a state where the assist arm has been removed from the arm body). 
         FIGS. 6A to 6D  are detail views of the hinge of the embodiment ( FIG. 6A  is a plan view,  FIG. 6B  is a right side view,  FIG. 6C  is a bottom view, and  FIG. 6D  is a left side view). 
         FIGS. 7A and 7B  are cross-sectional views of the hinge of the embodiment ( FIG. 7A  is a cross-sectional view taken along A-A in  FIG. 6B , and  FIG. 7B  is a cross-sectional view taken along B-B in  FIG. 6B ). 
         FIGS. 8A to 8C  are plan views of the door opening/closing apparatus of the embodiment ( FIG. 8A  illustrates the closed position of the door,  FIG. 8B  illustrates the midpoint position of the door, and  FIG. 8C  illustrates the open position of the door). 
         FIG. 9  is a plan view of the door opening/closing apparatus of the embodiment. 
         FIG. 10  is a perspective view of the back side of the cabinet on which a shelf has been mounted. 
         FIG. 11  is a perspective view of a known door opening/closing apparatus. 
         FIGS. 12A and 12B  are plan views of a hinge of the known door opening/closing apparatus ( FIG. 12A  illustrates a closed position of a door, and  FIG. 12B  illustrates an open position of the door). 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     A door opening/closing apparatus of an embodiment of the present invention is described in detail hereinafter on the basis of the accompanying drawings. However, the door opening/closing apparatus of the present invention can be embodiment in various modes, and is not limited to the embodiment described in the description. The embodiment is provided with the intention of allowing those skilled in the art to fully understand the scope of the invention by fully disclosing the description. 
       FIGS. 1A to 1C  are perspective views of a front side of a cabinet using a door opening/closing apparatus  1  of one embodiment of the present invention (a door  4  is indicated by chain double-dashed lines).  FIGS. 2A to 2C  are perspective views of a back side of the cabinet (a part of a main body  5  is indicated by a break line). For convenience of description, directions of when the door  4  is viewed from the front, that is, the directions illustrated in the figures: front and back; up and down; and left and right, are used below to describe the configuration of the door opening/closing apparatus  1 . Naturally, the placement of the door opening/closing apparatus  1  is not limited to the above. 
       FIG. 1A  illustrates a closed position of the door  4 .  FIG. 1B  illustrates a midpoint position of the door  4 .  FIG. 1C  illustrates an open position of the door  4 . A reference sign  2   a  denotes an upper hinge. A reference sign  2   b  denotes a lower hinge. A reference sign  3  denotes a connecting bar that connects the hinges  2   a  and  2   b . The door opening/closing apparatus  1  includes a pair of the hinges  2   a  and  2   b , and the connecting bar  3  that is connected to the pair of the hinges  2   a  and  2   b . When the door  4  is pulled toward the front from the closed position illustrated in  FIG. 1A , the door  4  performs pivotal motion, maintaining parallelism, and then opens to the open position illustrated in  FIG. 1C  through the midpoint position (the maximum opening projection toward the front) illustrated in  FIG. 1B . The main body  5  is open to its full width in the open position. 
     Conversely, when the door  4  is pulled toward the front from the open position illustrated in  FIG. 1C , the door  4  performs pivotal motion, maintaining parallelism, and then closes to the closed position illustrated in  FIG. 1A  through the midpoint position illustrated in  FIG. 1B . A catch mechanism and a damper mechanism, which are described below, are incorporated into the hinges  2   a  and  2   b . The catch mechanism causes the door  4  to automatically close right before the closed position. The damper mechanism causes the door  4  to softly close to the closed position. 
     The hinge  2   a  includes a main body-side member  11  that is mounted on an inner surface of a side plate  5   a  of the main body  5 , a door-side member  12  that is mounted on the back of the door  4 , a main arm  13  that is pivotably connected to the main body-side member  11  and the door-side member  12 , a first link  14  that is pivotably connected to the main body-side member  11  and the door-side member  12 , and a second link  15  that is pivotably connected to the main body-side member  11  and the door-side member  12 . The main arm  13 , the first link  14 , and the second link  15  each include a bent portion, and are bent into an L-shape to prevent themselves from interfering with the side plate  5   a  of the main body  5  and an unillustrated neighboring door in the open position of the door  4  as illustrated in  FIG. 2C . 
     The hinges  2   a  and  2   b  are configured to be the same or vertically symmetric. Only the configuration of the hinge  2   a  is described below, and the description of the hinge  2   b  is omitted. 
       FIG. 3A  illustrates a perspective view of the hinge  2   a  as viewed from the main body  5  side.  FIG. 3B  illustrates a perspective view of the hinge  2   a  as viewed from the door  4  side. The first link  14  is placed on one side (an upper side) of the main arm  13  in an axial direction (the up-and-down direction in  FIG. 3A ), displaced from the main arm  13 . The second link  15  is placed on the other side (a lower side) of the main arm  13  in the axial direction (the up-and-down direction), displaced from the main arm  13 . 
       FIG. 4  is an exploded perspective view of the hinge. The reference sign  11  denotes the main body-side member. The reference sign  12  denotes the door-side member. The reference sign  13  denotes the main arm. The reference sign  14  denotes the first link. The reference sign  15  denotes the second link. 
     Firstly, a linkage mechanism of the door opening/closing apparatus  1  is described. One end of the main arm  13  is connected to the main body-side member  11  in such a manner as to be pivotable about a first shaft  13   a . The other end of the main arm  13  is connected to the door-side member  12  in such a manner as to be pivotable about a second shaft  13   b . One end of the first link  14  is connected to the main body-side member  11  in such a manner as to be pivotable about a first shaft  14   a . The other end of the first link  14  is connected to the door-side member  12  in such a manner as to be pivotable about a second shaft  14   b . Similarly, one end of the second link  15  is connected to the main body-side member  11  in such a manner as to be pivotable about a first shaft  15   a . The other end of the second link  15  is connected to the door-side member  12  in such a manner as to be pivotable about a second shaft  15   b.    
     The pitch between the first shaft  13   a  and the second shaft  13   b  of the main arm  13 , the pitch between the first shaft  14   a  and the second shaft  14   b  of the first link  14 , and the pitch between the first shaft  15   a  and the second shaft  15   b  of the second link  15  are equal to each other. The three first shafts  13   a ,  14   a , and  15   a  are placed on the vertices of a triangle in axial view. The three second shafts  13   b ,  14   b , and  15   b  are also placed on the vertices of a triangle in axial view. When the door  4  opens and closes, a triangle t 1  (refer to  FIG. 8A ) including the first shafts  13   a ,  14   a , and  15   a , and a triangle t 2  (refer to  FIG. 8A ) including the second shafts  13   b ,  14   b , and  15   b  maintain parallelism, and the door  4  moves parallel to itself between the closed position and the open position, as illustrated in  FIGS. 8A to 8C . 
     Next, the configuration of each unit of the door opening/closing apparatus  1  is described. As illustrated in  FIG. 4 , the main body-side member  11  includes a plate  21  that is fixed to the main body  5  with a fastening member such as a screw, and a bracket  22  that is fixed to the plate  21  with a fastening member such as a screw in such a manner as to be adjustable in position in the front-and-back direction. The bracket  22  has a squared U-shape in cross section. A pair of side plates  22   a  and  22   b  of the bracket  22 , which face each other, protrude from slits  21   a  in the plate  21 . A hole into which the first shaft  13   a  of the main arm  13  is inserted is formed in the side plates  22   a  and  22   b . A hole into which the first shaft  14   a  of the first link  14  is inserted is formed in the side plate  22   a . A hole into which the first shaft  15   a  of the second link  15  is inserted is formed in the side plate  22   b . The main arm  13  is placed between the pair of side plates  22   a  and  22   b . The first link  14  and the second link  15  are placed on outer sides of the pair of side plates  22   a  and  22   b  in the axial direction. 
     The position of the bracket  22  is adjusted in the front-and-back direction relative to the plate  21 ; accordingly, the position of the door  4  can be adjusted in the front-and-back direction. After the adjustment, a washer cover  23  (refer to  FIG. 7A ) is mounted on the main body-side member  11 . 
     As illustrated in  FIG. 4 , the door-side member  12  includes a plate  24  that is fixed to the door  4  with a fastening member such as a screw, a bracket  25  that is fixed to the plate  24  with a fastening member such as a screw in such a manner as to be adjustable in position in the left-and-right direction and in the up-and-down direction, an angle adjustment plate  26  that is fixed to the bracket  25  with a fastening member such as a screw in such a manner as to be adjustable in inclination, and a cam  27  that is fixed to the angle adjustment plate  26  with a fastening member such as a screw. 
     All of the bracket  25 , the angle adjustment plate  26 , and the cam  27  are formed into a squared U-shape in cross section. A hole into which the second shaft  13   b  of the main arm  13  is inserted is formed in side plates  26   a  and  26   b  of the angle adjustment plate  26 . A hole into which the second shaft  14   b  of the first link  14  is inserted is formed in the side plate  26   a . A hole into which the second shaft  15   b  of the second link  15  is inserted is formed in the side plate  26   b . The main arm  13  is placed between a pair of the side plates  26   a  and  26   b  of the angle adjustment plate  26 . The first link  14  and the second link  15  are placed on outer sides of a pair of side plates of the bracket  25  in the axial direction. 
     The position of the bracket  25  is adjusted in the left-and-right direction and in the up-and-down direction relative to the plate  24 ; accordingly, the position of the door  4  can be adjusted in the left-and-right direction and in the up-and-down direction. The inclination of the angle adjustment plate  26  relative to the bracket  25  is adjusted; accordingly, the inclination of the door  4  can be adjusted. After the adjustment, a washer cover  28  (refer to  FIG. 7A ) is mounted on the door-side member  12 . 
     As illustrated in  FIG. 4 , the main arm  13  includes an arm body  31 , an assist arm  32 , a catch mechanism  33 , and a damper mechanism  34 . 
     As illustrated in  FIGS. 5A and 5B , the arm body  31  has an L-shape, and includes a straight short-side portion  31   c  and a straight long-side portion  31   b  on either side of a bent portion  31   a . The long-side portion  31   b  of the arm body  31  has a squared U-shape in cross section, and includes a pair of opposing side plates  31   b   1 , and a connecting plate  31   b   2  that connects the pair of side plates  31   b   1 . A mounting portion  31   d  on which the connecting bar  3  is mounted is formed integrally with the pair of side plates  31   b   1  of the long-side portion  31   b . The arm body  31  is produced by pressing a metal plate. 
     As illustrated in  FIGS. 5A and 5B , the assist arm  32  has a squared U-shape in cross section, and includes a pair of opposing side plates  32   a , and a connecting plate  32   b  that connects the pair of side plates  32   a . The assist arm  32  is produced by pressing a metal plate. The assist arm  32  is inserted between the side plates  31   b   1  of the arm body  31  to form the main arm  13  into a square tubular shape in cross section. 
     As illustrated in  FIG. 4 , a substantially L-shaped resin spacer  36  is inserted between a pair of side plates of the short-side portion  31   c  of the arm body  31 . The assist arm  32  and the spacer  36  are fixed to the arm body  31  with a screw. The assist arm  32  and the spacer  36  increase the strength of the main arm  13 . 
     As illustrated in  FIG. 7A , a hole  36   a  into which the damper mechanism  34  is inserted is formed in the spacer  36 . The damper mechanism  34  includes a linear damper  38  and a damper holder  37 . The damper holder  37  has a bottomed tubular shape. The linear damper  38  is housed in the damper holder  37 . A damper stopper  39  is mounted on the main body-side member  11 . When the door  4  has closed to the vicinity of the closed position, the damper holder  37  comes into contact with the damper stopper  39  to generate a damping force. 
     As illustrated in  FIG. 4 , the catch mechanism  33  is integrated into a tubular space between the arm body  31  and the assist arm  32 . The catch mechanism  33  includes a compression spring  41 , a spring case  42 , and a roller  43 . As illustrated in  FIGS. 7A and 7B , the spring case  42  is provided to the main arm  13  in such a manner as to be movable in the length direction. The roller  43  is provided to the spring case  42  in such a manner as to be rotatable. The compression spring  41  biases the roller  43  toward the cam  27  of the door-side member  12 . When the door  4  has closed to the vicinity of the closed position, the roller  43  fits into a recess of the cam  27  as illustrated in  FIG. 7A , and the door  4  closes automatically. When the door  4  opens and the roller  43  comes into contact with an arc surface of the cam  27 , an arbitrary angle of opening of the door  4  is maintained. 
     As illustrated in  FIG. 4 , the first link  14  has an L-shape, and includes a straight short-side portion  14   e  and a straight long-side portion  14   d  on either side of a bent portion  14   c . The first link  14  has a plate shape. The second link  15  also has an L-shape, and includes a straight short-side portion  15   e  and a straight long-side portion  15   d  on either side of a bent portion  15   c . The second link  15  also has a plate shape. 
     A finger pinch prevention cover  41  has an L-shape, and includes an upper cover  41   a , and a lower cover  41   b . Each of the upper cover  41   a  and the lower cover  41   b  includes a straight long-side portion and a straight short-side portion on either side of a bent portion as in the main arm  13 . The upper cover  41   a  is mounted on the top of the main arm  13 . The lower cover  41   b  is mounted on the bottom of the main arm  13 . The upper cover  41   a  and the lower cover  41   b  surround the main arm  13 . Holes  42   a  and  42   b  where the first shaft  13   a  and the second shaft  13   b  penetrate are formed in the upper cover  41   a  and the lower cover  41   b . Reference signs  43   a  and  43   b  denote collars. The width (the width in a direction orthogonal to the length direction) of each of the upper cover  41   a  and the lower cover  41   b  is longer than that of the main arm  13 . 
     As illustrated in  FIGS. 8A to 8C , the finger pinch prevention cover  41  eliminates a gap between the main arm  13  and the first link  14  in axial view, and also eliminates a gap between the main arm  13  and the second link  15  in axial view. A gap does not appear between the finger pinch prevention cover  41  and the first link  14  in axial view, and a gap does not appear between the finger pinch prevention cover  41  and the second link  15  in axial view, all the way from the closed position to open position of the door  4 . 
     Moreover, as illustrated  FIGS. 6B and 6D , the finger pinch prevention cover  41  reduces or eliminates a gap in the axial direction between the main arm  13  and the first link  14 , and also reduces or eliminates a gap in the axial direction between the main arm  13  and the second link  15 . A gap  61  in the axial direction between the finger pinch prevention cover  41  and the first link  14  and a gap  62  in the axial direction between the finger pinch prevention cover  41  and the second link  15  is, for example, from equal to or greater than 0 mm to equal to or less than 2 mm. 
     As illustrated in  FIGS. 1A to 1C , the plate-shaped connecting bar  3  extending in the up-and-down direction is mounted on the pair of the upper and lower hinges  2   a  and  2   b  with fastening members such as screws. As illustrated in  FIG. 9 , the connecting bar  3  is mounted on the mounting portion  31   d  of the main arm  13 . The mounting method of the connecting bar  3  is not particularly limited. For example, a screw is caused to penetrate through each of four corners of the mounting portion  31   d . A square nut is threadedly engaged with the screw. The square nuts are aligned with and then inserted into grooves in the connecting bar  3 . The screws are tightened and consequently the connecting bar  3  can be mounted on the mounting portion  31   d.    
     The mounting portion  31   d  is placed on the door  4  side of the main arm  13 . The connecting bar  3  is mounted on the door  4  side of the main arm  13 . Moreover, a center B′ of the mounting portion  31   d  in a width direction thereof and a center B of the connecting bar  3  in a width direction thereof are placed on the second shaft  13   b  side relative to a center C between the first shaft  13   a  of the main arm  13  and the second shaft  13   b  of the main arm  13  in front view (indicated by an open arrow A in FIG.  9 ) in a state where the door  4  is in the closed position. In the embodiment, the entire mounting portion  31   d  and the entire connecting bar  3  are placed on the second shaft  13   b  side relative to the center C. As illustrated in  FIGS. 8A to 8C , the connecting bar  3  is located forward of the first link  14  and the second link  15  in the opening direction all the way from the closed position to open position of the door  4 . The connecting bar  3  does not interfere with the first link  14  and the second link  15 . 
     The configuration of the door opening/closing apparatus  1  of the embodiment has been described above. The door opening/closing apparatus  1  of the embodiment has the following effects: 
     The main arm  13  includes the bent portion  31   a . Closer to the second shaft  13   b  on the main arm  13  indicates closer to the door  4 . The connecting bar  3  is placed on the door  4  side and the second shaft  13   b  side of the main arm  13 . Accordingly, the connecting bar  3  can be put closer to the back of the door  4 . Hence, storage space in the main body  5  can be expanded. 
     Moreover, the connecting bar  3  is placed close to the second shaft  13   b . Therefore, even if a shelf  5   b  is installed on the side plate  5   a  of the main body  5 , for example, as illustrated in  FIG. 10 , it is possible to prevent the shelf  5   b  from interfering with the connecting bar  3 . 
     The first link  14  is placed on one side of the main arm  13  in the axial direction. The second link  15  is placed on the other side of the main arm  13  in the axial direction. Accordingly, it is possible to ensure the strength of the door opening/closing apparatus  1  and to render the door opening/closing apparatus  1  compact. 
     The main arm  13  includes the metal arm body  31  of a squared U-shape in cross section, and the metal assist arm  32  of a squared U-shape in cross section fastened to the arm body  31 . The main arm  13  is formed into a square tubular shape in cross section. Accordingly, it is possible to ensure the strength of the main arm  13 . 
     The finger pinch prevention cover  41  that reduces or eliminates the gaps between the main arm  13  and the first link (the gap in axial view and the gap  61 ,  62  in the axial direction) is mounted on the main arm  13 . Accordingly, it is possible to prevent fingers from getting caught in these gaps. The same applies to the gaps between the main arm  13  and the second link  15 . 
     The present invention is not limited to the realization of the above embodiment, and can be realized in various embodiments within the scope where the gist of the present invention is not changed. 
     In the above embodiment, the door opening/closing apparatus is mounted on the side plate of the main body, and the door is opened and closed in the left-and-right direction. However, it is also possible to mount the door opening/closing apparatus on an upper or lower plate of the main body to open and close the door in the up-and-down direction. 
     In the above embodiment, the connecting bar is mounted on a pair of hinges. It is also possible to mount the connecting bar on three or more hinges. 
     In the above embodiment, there is no gap between the finger pinch prevention cover and the first link in axial view. However, there may be a gap that is too narrow to pinch fingers. The same applies to the gap between the finger pinch prevention cover and the second link in axial view. 
     The description is based on Japanese Patent Application No. 2018-198999 filed on Oct. 23, 2018, the entire contents of which are incorporated herein. 
     REFERENCE SIGNS LIST 
     
         
           1  Door opening/closing apparatus 
           2   a ,  2   b  Hinge 
           3  Connecting bar 
           4  Door 
           5  Main body 
           11  Main body-side member 
           12  Door-side member 
           13  Main arm 
           13   a  First shaft of the main arm 
           13   b  Second shaft of the main arm 
           14  First link 
           14   a  First shaft of the first link 
           14   b  Second shaft of the first link 
           15  Second link 
           15   a  First shaft of the second link 
           15   b  Second shaft of the second link 
           31  Arm body 
           31   a  Bent portion of the main arm 
           32  Assist arm 
           41  Finger pinch prevention cover 
         A Door in front view 
         B Center of the connecting bar in width direction 
         C Center between the first and second shafts of the main arm