Patent Publication Number: US-2007107352-A1

Title: Construction of wall opening in steel house

Description:
TECHNICAL FIELD  
      This invention relates to a construction of a wall opening in a steel house.  
     BACKGROUND ART  
      A steel house can be defined as a 2×4 (two-by-four) house of iron skeletal frames having a steel type panel construction constituted by frame members and structural face members each made of thin light-weight shape steel having a sheet thickness of about 1 mm.  
      The frame members of such a steel house are shaped into sectional shapes such as a groove shape, a groove shape with lips and a box shape by roll-forming a thin steel sheet. The frame members are shaped in such a fashion that their width satisfies a predetermined specification. To execute working of the steel house, it is customary to fasten a plurality of frame members by drill screws to constitute reinforcing frame members and to constitute a main erection structure by bonding these members by drill screws.  
      Next, the construction of a steel house by a construction method for a steel house according to the prior art will be explained with reference to FIGS.  7  to  9 .  
      To build the steel house, a plurality of longitudinal frame members  2  are rised with predetermined gaps between them at lower frame members  1  as shown in  FIG. 7 . The upper end of each longitudinal frame member  2  is interconnected to the upper ends of other frame members  2  through an upper frame member  3 . Structural face members  7  are fixed to wall frame members constituted by the lower frame members  1 , the longitudinal frame members  2  and the upper frame members  3  through drill screws  23  as shown in  FIG. 9 . Openings  8  such as entrances and exits  8   a  and windows  8   b  are formed in this steel house.  
      Side floor joists  5   a  and end floor joists  5   b  are supported by the upper frame members  3  to which the structural face members  7  are fitted, and both of these floor joists  5   a  and  5   b  are assembled into a rectangular shape. A plurality of floor joists  10  is arranged, with predetermined gaps between the joists, in parallel with the side floor joists  5   a  and both ends of each elongated floor joist  10  are connected to the front or rear end floor joist  5   b  or floor beams  12  by bracket metals  11 . One of the ends of each short floor joist  10  is connected to the front or rear end floor joist  5   b  and the other end, to the floor beam  12  (or to a cleat  10   d ) through the bracket metals  11  (or a floor joist bracket metal  10   c ), respectively. One of the ends of each floor joist  10   b  on the opening side is connected to the end floor joist  10  and the other end, to the floor joist  10   a  on the floor opening side. The structural face member  13  is fitted to a floor frame member  14  constituted by these floor joists  10  and floor beams  12 .  
      Incidentally, longitudinal frame members  2  do not exist in the openings  8  such as the entrances and exits  8   a  and  8   b  of this steel house. Because the support poles in the longitudinal direction for supporting the vertical load from the upper floor such as a roof do not exist in the openings  8 , therefore, the openings  8  are low in strength. A lintel  15  is therefore arranged above each opening  8  to reinforce the upper part of the opening  8 .  
       FIG. 8  shows the detail of the fitting position of the lintel  15 . As shown in this  FIG. 8 , an upper frame member  3  and a lintel frame member  17  are arranged above and below the window  8   b  (opening  8 ) and a lintel longitudinal frame member  19  is interposed between the lintel frame member  17  and the opening upper frame member  18 . Both ends of the lintel  15  are fixed to lintel receptacles  20  through lintel metal bracket  21 . Each lintel receptacle  20  is fixed to a longitudinal frame member  22  for accepting and fitting the lintel. The lower and upper ends of this longitudinal frame member  22  for accepting and fitting the lintel are fixed to the lower frame member  1  and to the upper frame member  3  through the drill screws  23 . The opening lower frame member  24  is supported at is lower end by the upper end of the opening lower longitudinal frame member  25  the lower end of which is fixed to the lower frame member  1  or through a bracket  24   a.    
      Incidentally, a structural face member is fixed by the drill screws  23  to the opening lower frame member  24  and each frame member arranged above the former to constitute a vertical wall  26  as shown in  FIG. 9 . A structural face member is fixed by the drill screws  23  to the opening lower frame member  24  and each frame member arranged below the former to constitute a wainscot wall  27  as shown in  FIG. 9 . Further, the structural face members  23  are fixed to the longitudinal frame members  22  for accepting and fitting the lintel and to the frame members (longitudinal frame members  2   a ) on both outer sides of this frame member  22  by the drill screws  23  to form each side face wall  28 .  
      Incidentally, because the support poles do not exist inside the opening  8 , the four sides of the opening upper frame member  18 , the opening lower frame member  24  and the longitudinal frame  22  for accepting and fitting the lintel undergo displacement in the horizontal direction when a stress in the horizontal direction, due to a earthquake and so forth, acts on them. When the vertical wall  26 , the wainscot wall  27  and the side wall  28  are rigidly coupled with one another during such horizontal displacement, each wall operates as a strong wall and the displacement of the frame members around the opening  8  can be suppressed.  
      According to the prior art, however, the vertical wall  26 , the wainscot wall  27  and the side wall  28  are loosely coupled with one another so that displacement does not occur among these walls.  FIGS. 10 and 11  show the behavior when the horizontal force is applied to the vertical wall  26 , the wainscot wall  27  and the side face wall  28  according to the prior art. As shown in  FIGS. 10 and 11 , the side wall  28  rocks due to the horizontal force that is applied. Because the side face wall  28  is loosely coupled with the vertical wall  26  and the wainscot wall  27 , however, the horizontal force is not transmitted to these walls  26  and  27 . In other words, the horizontal force applied to the periphery of the opening  8  is substantially fully borne by the side face wall  28  and is offset through rocking of such a side face wall  28 .  
      Incidentally, a “Wall Structure and Face Member Bonding Method” that deviates the joint portions of face members of side walls (wing walls) from the positions of plywood of vertical walls has been proposed in the past (for example, Japanese Unexamined Patent Publication (Kokai) No. 2000-234406). A “Calculation Method of Wooden Houses and Wooden Houses Using the Method” has also been proposed (for example, Japanese Unexamined Patent Publication No. 2001-164645).  
     DISCLOSURE OF THE INVENTION  
      In the example described above and shown in  FIGS. 10 and 11 , the side face walls  28  disposed on both sides of the opening  8  are spaced apart from the vertical walls  26  positioned above and below the opening  8  and from the wainscot wall  27 . For this reason, each side face wall  28  has a small resistance to rocking in the horizontal direction, due to the earthquake, etc, so that the quantity of deformation in the horizontal direction becomes great. Furthermore, a pull force represented by a downward vector as indicated by arrows in  FIG. 11 , a compressive force represented by an upward vector, a rightward force and a leftward force operate alternately and in a cycle.  
      In other words, the forces operating in these directions mutually have the relation of action and reaction and maintain a mutual balance. Therefore, the greater the magnitude of rocking in the transverse direction, the greater becomes the pull force and the compressive force. The pull force, in particular, is the sum of the vector amounts in the ellipse (X) of dotted line in  FIG. 11 . Therefore, when this pull force becomes great, the compressive force becomes great, too. To cope with the increase of this pull force (compressive force), the size of the longitudinal frame member for fitting the side face wall  28  must be increased and the size of hold-down metals for fitting the longitudinal frame member to the foundation, etc, must be increased to make them more rigid. Furthermore, anchors for fixing the hold-down metals to the concrete foundation must be thicker to improve the strength.  
      When the hold-down metal is made large in size to cope with such a pull force (compressive force), however, the strength of the structure itself around the opening  8  can be increased but when the steel house is considered as a whole, a structure having a high strength is arranged only at a part. Therefore, when a large horizontal force is applied to the steel house, due to an earthquake, etc, the stress concentrates on the periphery of the opening reinforced to a high level and a large load is also applied to other structural members. When such structural members are similarly fixed and reinforced separately by reinforcing members, the reinforcing members are eventually arranged throughout the entire steel house and this is not reasonable from the production cost and the labor.  
       FIG. 12  shows the relation of the shearing strength with respect to the shearing deformation amount of the side walls  28  arranged on both sides of the opening  8 . As shown in  FIG. 12 , when the construction in which the side face walls  28  are separated from the vertical wall  26  and the wainscot wall  27  positioned above and below the opening  8  as shown in  FIG. 12  is employed, the shearing stress gradually becomes great with the shearing deformation amount as indicated by p in the drawing. In contrast, when the frame members around the opening  8  are reinforced by the hold-down metals, or the like, the initial rigidity can be improved as indicated by q in the drawing but the shearing stress greatly increases.  
      Therefore, it has been necessary to eliminate the stress concentration inside the steel house by keeping the shearing stress at a low level while the initial rigidity is kept at a high level as indicated by the behavior r of the frame members around the opening  8 .  
      The invention has been completed in view of the problems described above and an object of the invention is to provide a reinforcing construction of an opening wall in a steel house capable of suppressing shearing stress to a low level while keeping, especially, the initial rigidity at a high level. In this construction, each side face wall is so arranged as to be clamped between a vertical wall panel and a wainscot panel, an opening upper frame member to which a lower end of the vertical panel is fixed and an opening lower frame member to which an upper end of the wainscot panel is fixed are fixed through joint metals  81  to each transverse frame member constituting a side face wall frame member to which the side face wall is fixed.  
      In other words, a construction of an opening wall in a steel house to which the invention is applied comprises two side face wall frame members, a vertical panel and a wainscot panel; each of the side face wall frame members comprising an opening formed by an opening upper frame member to which a lower end of the vertical panel is fixed, an opening lower frame member to which an upper end of the wainscot panel is fixed, two longitudinal frame members implanted on both sides of the frame members, outer longitudinal frame members implanted outside the longitudinal frame members, respectively, and transverse frame members for supporting portions between upper ends and lower ends of the longitudinal frame members and the outer longitudinal frame members, respectively; wherein face members constituting the wainscot panel are extended to and integrated with upper parts of side face walls, face members constituting the wainscot panel are extended to and integrated with lower parts of the side face wall, and the face members of the side face wall on the side of the opening are divided. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view of a reinforcing construction to which the invention is applied.  
       FIG. 2  is an explanatory view for explaining a framework of the reinforcing construction to which the invention is applied.  
       FIG. 3  is an explanatory view for explaining the arrangement position of each wall panel in the reinforcing construction to which the invention is applied.  
       FIG. 4  is an explanatory view for explaining a behavior when horizontal force acts on the reinforcing construction.  
       FIG. 5  is another explanatory view for explaining the behavior when the horizontal force acts on the reinforcing construction.  
       FIG. 6  shows the relation of shearing stress with a shearing deformation amount of side walls arranged on both sides of an opening.  
       FIG. 7  is an explanatory view for explaining a construction of a steel house.  
       FIG. 8  shows the detail of lintel fitting positions.  
       FIG. 9  is an explanatory view for explaining each fixing position of a structural face member.  
       FIG. 10  is a view showing a behavior when a horizontal force acts on a vertical wall, a wainscot wall and a side face wall according to the prior art.  
       FIG. 11  is another view showing a behavior when horizontal force acts on a vertical wall, a wainscot wall and a side face wall according to the prior art.  
       FIG. 12  is an explanatory view for explaining problems of the invention. 
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION  
      A reinforcing construction of a wall opening in a steel house will be hereinafter explained in detail with reference to the accompanying drawings as the best mode for carrying out the invention.  
      A reinforcing construction  50 , to which the invention is applied, is a construction for reinforcing an opening  51  as typified by an entrance-and-exit of the steel house as shown in FIGS.  1  to  3 . As the framework of this reinforcing construction  50 , a plurality of shape frame members  53  are implanted with predetermined gaps among them from lower frame members  52  as shown in  FIGS. 1 and 2  and the upper end of each shape frame member  53  is fixed to an opening lower frame member  54 . A plurality of shape frame members  56  is implanted with predetermined gaps among them from upper frame members  55  and the lower end of each shape frame member  56  is fixed to an opening upper frame member  57 .  
      Side face wall frame members  64  are formed on both sides of an opening  51 . Each side face wall member  64  comprises a longitudinal frame member  58  implanted on each side of the opening  51  defined between the opening upper frame member  57  and the opening lower frame member  54 , an outer longitudinal member  59  arranged outside each longitudinal frame member  58 , a transverse frame member  61  arranged to support the longitudinal frame member  58  and the outer longitudinal frame member  59 , and a transverse frame member  62  arranged to support the longitudinal frame member  58  and the outer longitudinal frame member  59 .  
      In this reinforcing construction  50 , longitudinal frame members  121  having a rectangular sectional shape are arranged to extend from the lower frame member  52  to the upper frame member  55 . An intermediate longitudinal frame member  131  is arranged between the longitudinal frame member  121  and the outer longitudinal frame member  59  in such a fashion as to extend from the lower frame member  52  to the upper frame member  55 . Incidentally, each outer longitudinal frame member  59  may be arranged to similarly extend from the lower frame member  52  to the upper frame member  55 .  
      Side face upper frame members  157  are further arranged at both ends of each opening upper frame member  57  and side face lower frame members  154  are arranged at both ends of each opening lower frame member  54 . In other words, the opening upper frame member  57  and the side face upper frame member  157  and the opening lower frame member  54  and the side surface lower frame member  154  are arranged in a mutually split form at the same height. A notch, not shown in the drawings, for inserting a plate, not shown, for supporting the opening upper frame member  57  and the side face upper frame member  157  or a plate, not shown, for supporting the opening lower frame member  54  and the side surface lower frame member  154  may be formed in the longitudinal frame member  121 .  
      A vertical wall panel  71  such as one shown in  FIG. 3  is fitted to each of the upper frame member  55 , the opening upper frame member  57  and the side face upper frame member  157 . A wainscot panel  72  is fitted to each of the opening lower frame member  54 , the side face lower frame member  154  and the lower frame member  52 . In other words, the lower end portion of the wainscot panel  71  is fixed to the opening upper frame  57  and the upper end portion of the wainscot panel  72  is fixed to the opening lower frame member  54 . Incidentally, both ends of the vertical wall panel  71  and the wainscot panel  72  may be extended to positions near the formation position of the outer longitudinal frame member  59 .  
      A side face wall  73  is fitted to a side surface wall frame member  64 . The side face surface wall  73  is fixed in such a manner as to be clamped between the vertical wall panel  71  and the wainscot panel  72  as shown in  FIG. 3 .  
      Each frame member is formed of a channel that is produced by bending a thin steel sheet having a thickness of about 1.0 mm to about 1.6 mm so that a web and flanges at both ends of the web continue integrally. The lower frame member  52  is constituted by a web  52   a  and flanges  52   b  formed on both sides of the web  52   a  as shown in  FIG. 1 . The shape frame member  53  including a web  53   a , flanges  53   b  on both sides of the web and lips  53   c  at the distal end of the flanges  53   b  is inserted into the lower frame member  52  substantially from the vertical direction. Drill screws, not shown, are set to their overlapping portions to bond these members with one another. Similarly, the opening lower frame member  54  is constituted by a web  54   a  and flanges  54   b  arranged on both sides of the web  54   a  and the frame member  53  is inserted into the opening lower frame member  54  substantially from the vertical direction.  
      The backs of the rear surfaces of the side face lower frame member  154  and the transverse frame member  62  are bonded to each other in such a fashion that the section describes substantially an H shape. Joint metals  81  such as drill screws are struck to the side surface lower frame member  154  and the transverse frame member  62  to bond them together. In consequence, the side wall portion of the vertical panel  71  or the wainscot panel  72  is fixed by the joint metals  81 .  
      The joint metal  81  is not limited to the drill screw but may be constituted by any fastening member such as a bolt-and-nut. Any other bonding means such as welding may also be employed instead of mounting the metal joint  81 .  
      Similarly, the side face upper frame member  157  constituted by the web  157   a  and the flanges  157   b  disposed on both sides of the web  157   a  is formed by bonding its rear surface to the rear surface of the transverse frame member  61  constituted by the web  61   a  and the flanges  61   b  in such a fashion that the section describes substantially an H shape. The metal joint  81  is connected to the side face upper frame member  157  and the transverse frame  61  that are so bonded.  
      Next, the behavior of a steel house, having the reinforcing construction  50  described above, when the horizontal force is applied will be explained.  
      First, when applied to the steel house, the horizontal force is transmitted to the reinforcing construction  50  with the result that the entire reinforcing construction  50  undergoes deformation in the horizontal direction. In the reinforcing construction  50  according to the invention, however, the length of the side face wall  73  is smaller than that of the reinforcing construction of the opening according to the prior art and the initial rigidity itself of the side face wall  73  becomes great. As a result, the deflection amount itself of the side face wall  73  is small as shown in  FIG. 4  when the horizontal force applied is small. However, the portions having low strength in the reinforcing construction  50  are affected by the horizontal force and the metal joint  81  connecting to the flanges  61   a ,  62   a  of the transverse frames  61  and  62  to which the side face wall  73  is fixed, in particular, undergo elastic deformation or plastic deformation in the horizontal direction owing to such a horizontal force.  
      In other words, in comparison with the construction of the prior art, this construction can suppress the deformation of the side face walls. Therefore, even when slight vibration is imparted to the steel house, the construction can suppress the vibration.  
      In this reinforcing construction  50 , in particular, the side face wall  73  is interconnected to the vertical wall panel  71  and the wainscot panel  72  through the joint metals  81 . Therefore, even when the horizontal force acts on such a reinforcing construction  50 , the vertical wall panel and the wainscot panel can bear the horizontal force to a certain extent and deformation of the side face wall  73  is much more restricted. In other words, the vertical wall panel  71  and the wainscot panel  72  that are interconnected reduce the stress applied to the side face wall  73  and the section of the side face wall  73  can be made smaller.  
      When the large horizontal force acts on this reinforcing construction  50  owing to the earthquake, etc, too, the construction does break instantaneously, as shown in  FIG. 5 , because the side face wall  73  has high initial rigidity. When the portions of the reinforcing construction  50  that have low strength bear the horizontal force, the drill screws  23  (metal joint) connected to the flanges  61   a  and  62   a  of the transverse frame members  61  and  62  to which the face members of the side face walls  73  are fixed undergo deformation due to the horizontal force and eventually, the joint portions of these drill screws  23  are broken. Breakage of the drill screws  23  eventually invites lowering of the breaking stress of the reinforcing construction  50  as a whole.  
      In other words, this reinforcing construction does not much improve the final shearing stress in comparison with the prior art technology when the large horizontal force is applied, due to an earthquake, etc., but can prevent the state where a structure having a high strength is disposed at only a part of the entire steel house. Therefore, when the large horizontal force of an earthquake, etc., is applied to the steel house, the stress does not concentrate on the reinforcing construction  50  around the opening and a large load is not applied to other structural members, either.  
       FIG. 6  shows the relation of the shearing stress with the shearing deformation amount of the side face walls arranged on both sides of the opening. In comparison with the behavior t of the prior art, the behavior u of the reinforcing construction  50  according to the invention can suppress an increase in the shearing stress while keeping the initial rigidity at the high level. Therefore, the reinforcing construction  50  can suppress a local concentration of the stress inside the steel house. Because reinforcing members need not be provided separately to each constituent member of the steel house to cope with such a stress concentration, the production cost and the amount of labor can be reduced.  
      In the embodiment described above, the invention has been limitedly explained with reference the reinforcing construction  50  of the opening  51  constituting the windows and the entrances and exits of the steel house by way of example, but is not specifically limited to such portions and can of course be applied to any opening in the steel house.  
     INDUSTRIAL APPLICABILITY  
      According to the invention, the side face wall is arranged in such a fashion as to be clamped between the vertical wall panel and the wainscot panel, and the opening upper frame member to which the lower end of the vertical panel is fixed and the opening lower frame member to which the upper end of the wainscot panel is fixed are fixed through the joint metals to each transverse frame member constituting the side face wall frame body to which the side face wall is fixed. Consequently, the invention can limit the shearing stress to a low level while keeping the initial rigidity at a high level.