Patent Publication Number: US-2022227529-A1

Title: Prefabricated pallet shelf structure having adjustable width and height

Description:
FIELD OF THE INVENTION 
     The present invention relates to a prefabricated pallet rack structure capable of being adjusted in width and height, and more particularly, to a prefabricated pallet rack structure capable of being adjusted in width and height that is capable of being built on a pallet to stably accommodate goods therein and capable of laminating pallets up and down in a state where goods are accommodated therein if necessary so as to store the goods therein. 
     BACKGROUND OF THE RELATED ART 
     So as to transport objects through a forklift truck, generally, square pallets are used, and each pallet has given size holes passing through side surfaces thereof, so that as the forks of the forklift truck are inserted into the holes of the pallet, the pallet is ascended along the forks to allow the goods placed thereon to be transported. 
     In a process where the goods placed on the pallet are transported, however, they may easily fall down from the pallet, and in a state where the goods are placed on pallets, further, it is hard to laminate the pallets up and down, thereby additionally requiring a rack for storing the goods. 
     So as to solve the above-mentioned problems, a conventional prefabricated pallet rack structure is disclosed in Korean Patent No. 1808276 (hereinafter, referred to as ‘Patent Document’). 
     The conventional prefabricated pallet rack structure as disclosed in the Patent Document includes a pallet having an upper plate and a lower plate connected integrally with each other by means of a plurality of corner connecting rods and a plurality of side connecting rods, base members fittedly coupled to the corner connecting rods located on corners of the pallet and having vertically erected mounting pipes, a first column member having one pair of first vertical rods vertically erected in such a manner as to allow lower ends thereof to be inserted into the mounting pipes of the base members fittedly coupled to one side front side and the other side rear side of the pallet, a first horizontal rod attached between the top ends of one pair of first vertical rods, and a first coupling groove formed on top of the center of the first horizontal rod, and a second column member having one pair of second vertical rods vertically erected in such a manner as to allow lower ends thereof to be inserted into the mounting pipes of the base members fittedly coupled to the other side front side and one side rear side of the pallet, a second horizontal rod attached between the top ends of one pair of second vertical rods, and a second coupling groove formed on top of the center of the second horizontal rod in such a manner as to crossingly come into contact with the first coupling groove to allow the first horizontal rod and the second horizontal rod to cross each other on the same plane as each other. Further, each base member has a base plate located horizontally in a state of coming into contact with the underside of each corner of the lower plate of the pallet, and the vertically erected mounting pipe is welded on one side of the top of the base plate, while a corner support plate bent to a shape of “L” is being welded on the other side of the top of the base plate in such a manner as to be supported against the outer surfaces of each corner of the pallet. Also, the corner support plate has a fitting piece protruding horizontally from the other side end thereof, so that the corner support plate and the fitting piece are fittedly coupled to the corner connecting rod to a shape of “ ”, and the fitting piece is spaced apart from the base plate up and down by a thickness of the lower plate, so that the lower plate is placed between the base plate and the fitting piece. 
     According to the Patent Document, the conventional prefabricated pallet rack structure is coupled to the corners of the pallet so that it is built correspondingly to the width of the pallet, and further, the height of the rack structure is determined by means of the lengths of the column members so that there are limitations in sizes of goods placed on the rack structure for the pallet. 
     If the goods have width and height larger than the width and height of the rack structure, accordingly, the rack structure has to be unavoidably re-built on a relatively large size pallet, and as the sizes of the corner connecting rods are different according to the sizes of the pallets, however, there are difficulties to make the rack structures of different sizes. 
     Therefore, there is a definite need for the development of a prefabricated pallet rack structure capable of being built appropriately on pallets of various sizes through adjustment of the width and height thereof if necessary. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention has been made in view of the above-mentioned problems occurring in the related art, and it is an object of the present invention to provide a prefabricated pallet rack structure capable of being adjusted in width and height that is capable of being built on pallets of various sizes and appropriately adjusting the width and height thereof according to the sizes of goods to be placed on a pallet. 
     To accomplish the above-mentioned object, according to the present invention, there is provided a prefabricated pallet rack structure capable of being adjusted in width and height, which is fitted to a plurality of mounting portions formed on corners of a pallet to have a given width and a given height, the prefabricated pallet rack structure including: fixtures slidingly fitted to the plurality of mounting portions; a plurality of first assembling bars having one end fixedly fitted to the fixtures and the other end of a given length in a vertical direction; and a plurality of second assembling bars having one end fitted to the top end of the plurality of first assembling bars in such a manner as to be adjusted in height and the other end of a given length in a horizontal direction, wherein the plurality of second assembling bars is configured to allow the other end of the given length in the horizontal direction to cross to a shape of “X” in such a manner as to be drawnably fitted to each other to perform adjustment in the width. 
     According to the present invention, desirably, the prefabricated pallet rack structure further includes space adjustment members selectively mounted on the fixtures according to sizes of the mounting portions in such a manner as to allow the fixtures to be tightly fixed to the mounting portions. 
     According to the present invention, desirably, the prefabricated pallet rack structure further includes one pair of horizontal connecting bars of a given length in a horizontal direction in such a manner as to cross each other to a shape of “X” on centers thereof, so that instead of allowing the other end of each second assembling bar to be drawnably fitted to the other end of another second assembling bar, the other end of each second assembling bar is drawnably fitted to one end of each horizontal connecting bar. 
     According to the present invention, desirably, each fixture includes: a lower plate of a given size adapted to come into close contact with the underside of the pallet; a first side plate of a given size adapted to allow one end thereof to be connected to the lower plate and to allow the other end thereof to come into close contact with one side surface of the mounting portion; a second side plate of a given size adapted to allow one end thereof to be connected to the lower plate and to allow the other end thereof to come into close contact with the other side surface of the mounting portion; a fixing plate of a given length adapted to allow one end thereof to be connected to the second side plate and to allow the other end thereof to be parallel to the first side plate; and a plurality of cylindrical insertion pipes spaced apart from each other by a given distance on an outside thereof from the corner at which the first side plate and the second side plate abut against each other in such a manner as to allow the first assembling bar to be selectively inserted thereinto at different positions thereof. 
     According to the present invention, desirably, the fixing plate has a plurality of fitting slots formed thereon. 
     According to the present invention, desirably, each space adjustment member includes: a first locking plate of given width and length and having fitting portions of a given size protruding from one side surface thereof; a second locking plate of given width and length spaced apart from the first locking plate by a given distance by means of the fitting portions; extension plates of a given length extended in a vertical direction to a longitudinal direction of the second locking plate in such a manner as to allow one end thereof to be connected to the second locking plate; and a contacting plate of a given size connected to the extension plates in such a manner as to come into close contact with the mounting portion, and a plurality of space adjustment member sets is provided with the extension plates having different lengths according to the sizes of the mounting portions, so that one space adjustment member set having the extension plates of appropriate lengths according to the sizes of the mounting portions is selected and mounted on the fixtures. 
     According to the present invention, desirably, each space adjustment member includes: a first locking plate of given width and length and having fitting portions of a given size protruding from one side surface thereof; a second locking plate of given width and length spaced apart from the first locking plate by a given distance by means of the fitting portions; and an elastic contacting plate whose one end is connected to one end of the second locking plate and whose other end is bent to a given angle in such a manner as to be pressurizedly deformed by means of an elastic force, the second locking plate and the elastic contacting plate having a plane shape of a general “V” or “U”. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and advantages of the present invention will be apparent from the following detailed description of the embodiments of the invention in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a perspective view showing a prefabricated pallet rack structure capable of being adjusted in width and height according to the present invention; 
         FIG. 2  is an exploded perspective view showing the prefabricated pallet rack structure of  FIG. 1 ; 
         FIG. 3  is a front view showing the prefabricated pallet rack structure of  FIG. 1 ; 
         FIG. 4  is a plan view showing the prefabricated pallet rack structure of  FIG. 1 ; 
         FIG. 5  is a perspective view showing a fixture of the prefabricated pallet rack structure according to the present invention; 
         FIG. 6  is a plan view showing the fixture of the prefabricated pallet rack structure according to the present invention; 
         FIG. 7  shows (A) a perspective view showing a space adjusting member of the prefabricated pallet rack structure according to the present invention, and (B) a perspective view showing the space adjusting member of  FIG. 7A  mounted onto the fixture on the prefabricated pallet rack structure according to the present invention; 
         FIG. 8  shows (A) a perspective view showing another example of the space adjusting member of the prefabricated pallet rack structure according to the present invention, and (B) a perspective view showing the space adjusting member of  FIG. 8A  mounted onto the fixture on the prefabricated pallet rack structure according to the present invention; 
         FIGS. 9 and 10  are perspective and plan views showing an example in which the space adjusting member mounted onto the fixture is mounted onto a mounting portion of a pallet on the prefabricated pallet rack structure according to the present invention; 
         FIG. 11  is a perspective view showing a first assembling bar of the prefabricated pallet rack structure according to the present invention; 
         FIG. 12  is a front view showing an example in which the prefabricated pallet rack structure according to the present invention is adjusted in height; 
         FIG. 13  is a perspective view showing a second assembling bar of the prefabricated pallet rack structure according to the present invention; 
         FIG. 14  is a front view showing a horizontal connecting bar of the prefabricated pallet rack structure according to the present invention; 
         FIG. 15  is a plan view showing an example in which the prefabricated pallet rack structure according to the present invention is adjusted in width; 
         FIG. 16  is a perspective view showing an example in which an insertion pipe of the fixture is adjustable in position on prefabricated pallet rack structure according to the present invention; and 
         FIG. 17  is a perspective view showing an example in which the other end of one second assembling bar is drawnably fitted to the other end of another second assembling bar on prefabricated pallet rack structure according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Hereinafter, the present invention is disclosed with reference to the attached drawings. 
     The present invention provides a prefabricated pallet rack structure that is capable of mounting pallets having different sizes thereon and of being adjusted in width and height if necessary so as to accommodate goods having a larger width than a pallet therein, and as shown in  FIGS. 1 to 4 , the prefabricated pallet rack structure includes fixtures  10 , space adjusting members  20 , first assembling bars  30 , second assembling bars  40 , and horizontal connecting bars  50 . 
     The fixtures  10  are fixed to mounting portions  1 A having a sectional shape of a right square formed on corners of a pallet  1  so as to allow the first assembling bars  30  as will be discussed later to be erected vertically thereon. 
     As shown in  FIG. 5 , each fixture  10  includes a lower plate  11  of a given size formed of a rectangular plate in such a manner as to come into close contact with the underside of the pallet  1 , a vertically located first side plate  12  of a given size in such a manner as to allow one end thereof to be connected to the lower plate  11  and to allow the other end thereof to come into close contact with one side surface of the mounting portion  1 A, a vertically located second side plate  13  of a given size in such a manner as to allow one end thereof to be connected to the lower plate  11  and to allow the other end thereof to come into close contact with the other side surface of the mounting portion  1 A, and a fixing plate  14  of a given length in such a manner as to allow one end thereof to be connected to the second side plate  13  and to allow the other end thereof to be parallel to the first side plate  12 . 
     At this time, the fixing plate  14  has a plurality of fitting slots  14 A spaced apart from each other by a given distance, and the space adjusting members  20  as will be discussed later are selectively mounted onto the fitting slots  14 A, so that the fixture  10  can be fixed to the mounting portion  1 A of the pallet  1  of various sizes. 
     Further, the lower plate  11  has an extension plate  11 A extended protrudingly from one side thereof by a given length, and the extension plate  11 A has a plurality of insertion pipes  15  built thereon in such a manner as to fixedly fit the lower end of the first assembling bar  30  as will be discussed later thereto by a given depth. 
     The present invention provides a prefabricated pallet rack structure that is capable of mounting pallets having different sizes thereon and of being adjusted in width and height if necessary so as to accommodate goods having a larger width than a pallet therein, and as shown in  FIGS. 1 to 4 , the prefabricated pallet rack structure includes fixtures  10 , space adjusting members  20 , first assembling bars  30 , second assembling bars  40 , and horizontal connecting bars  50 . 
     The fixtures  10  are fixed to mounting portions  1 A having a sectional shape of a right square formed on corners of a pallet  1  so as to allow the first assembling bars  30  as will be discussed later to be erected vertically thereon. 
     As shown in  FIG. 5 , each fixture  10  includes a lower plate  11  of a given size formed of a rectangular plate in such a manner as to come into close contact with the underside of the pallet  1 , a vertically located first side plate  12  of a given size in such a manner as to allow one end thereof to be connected to the lower plate  11  and to allow the other end thereof to come into close contact with one side surface of the mounting portion  1 A, a vertically located second side plate  13  of a given size in such a manner as to allow one end thereof to be connected to the lower plate  11  and to allow the other end thereof to come into close contact with the other side surface of the mounting portion  1 A, and a fixing plate  14  of a given length in such a manner as to allow one end thereof to be connected to the second side plate  13  and to allow the other end thereof to be parallel to the first side plate  12 . 
     At this time, the fixing plate  14  has a plurality of fitting slots  14 A spaced apart from each other by a given distance, and the space adjusting members  20  as will be discussed later are selectively mounted onto the fitting slots  14 A, so that the fixture  10  can be fixed to the mounting portion  1 A of the pallet  1  of various sizes. 
     Further, the lower plate  11  has an extension plate  11 A extended protrudingly from one side thereof by a given length, and the extension plate  11 A has a plurality of insertion pipes  15  built thereon in such a manner as to fixedly fit the lower end of the first assembling bar  30  as will be discussed later thereto by a given depth. 
     Furthermore, the extension plate  11 A includes a pair of support plates  16  having one end fixed thereto and the other end vertically protruding from outer ends of the insertion pipes  15  and thus supporting both side ends of the insertion pipes  15  and a plurality of reinforcing plates  17  for connecting one pair of support plates  16  with the extension plate  11   a  in a diagonal direction, so that through one pair of support plates  16  and the plurality of reinforcing plates  17 , the insertion pipes  15  are reinforced and are not easily deformed even if a large external force is applied to the first assembly bar  30  in a transverse direction in a state where one insertion pipe  15  inserts the first assembling bar  30 . 
     Under the configuration of the fixtures  10 , accordingly, the space adjustment members  20  of various sizes are selectively mounted on the fixing plates  14 , so that the rack structure according to the present invention can be mounted on the pallets of various sizes, and further, the first assembling bars  30  are inserted into the insertion pipes  15  through appropriate position changing, so that the rack structure according to the present invention can be adjusted appropriately in width. 
     The space adjustment members  20  are mounted on the fixing plates  14  of the fixtures  10  to allow the fixtures  10  to be tightly fixed to the mounting portions  1 A of the pallet  1 . 
     As shown in  FIG. 7A , the space adjustment member  20  includes a first locking plate  21  of given width and length in such a manner as to come into close contact with one side surface of the fixing plate  14  and having fitting portions  21 A protruding therefrom in such a manner as to be inserted into the fitting slots  14 A, a second locking plate  22  spaced apart from the first locking plate  21  by a given distance by means of the fitting portions  21 A and having given width and length in such a manner as to come into close contact with the other side surface of the fixing plate  14 , extension plates  23  of a given length extended in a vertical direction to a longitudinal direction of the second locking plate  22  in such a manner as to allow one end thereof to be connected to the second locking plate  22 , and a contacting plate  24  of a given size connected to the extension plates  23  in such a manner as to come into close contact with the mounting portion  1 A. 
     At this time, the extension plates  23  of the space adjustment member  20  are made with different lengths according to the sizes of the pallets, and accordingly, a plurality of space adjustment member sets  20  is made through changes in a distance between the second locking plate  22  and the contacting plate  24 . 
     The space adjustment member  20  with the extension plates  23  having appropriate lengths is selected from the plurality of space adjustment member sets  20  according to the size of the mounting portion  1 A on which the fixture  10  is mounted. As shown in  FIG. 7B , the fitting portions  21 A are fitted to the fitting slots  14 A of the fixing plate  14 , and the first locking plate  21  and the second locking plate  22  of the space adjustment member  20  come into close contact with both side surfaces of the fixing plate  14 , while the contacting plate  24  is facing the first side plate  12  of the fixture  10 . 
     Further, as shown in  FIGS. 9A and 9B , the outer surfaces of the mounting portion  1 A located on each corner of the pallet  1  are inserted into “ ”-shaped inner surfaces formed by the first side plate  12  and the second side plate  13  of the fixture  10  and the contacting plate  24  of the space adjustment member  20 , and accordingly, as shown in  FIG. 10 , even if the outer surfaces of the mounting portion  1 A have sizes smaller than the “ ”-shaped inner surfaces formed by the first side plate  12  and the second side plate  13  and the contacting plate  24 , the fixture  10  can be rigidly fixed to the mounting portion  1 A. 
     Only if the space adjustment member  20  having an appropriate size is fixed to the fixing plate  14  of the fixture  10 , accordingly, the fixture  10  can be easily mounted onto the mounting portions  1 A of various sizes. 
     As mentioned above, the plurality of space adjustment members  20  is made through changes in lengths of the extension plates  23 , and instead of the extension plates  23 , otherwise, the space adjustment member  20  has an elastic contacting plate  24 ′ whose one end is connected to one end of the second locking plate  22  and whose other end is bent to a given angle in such a manner as to be pressurizedly deformed by means of an elastic force, as shown in  FIGS. 8A and 8B . 
     At this time, a plane formed by the second locking plate  22  and the elastic contacting plate  24 ′ has a shape of a general “V” or “U”, so that when the fixture  10  is fitted to the mounting portion  1 A, the free end of the elastic contacting plate  24 ′ is naturally pressurized against the outer surface of the mounting portion  1 A, thereby allowing the fixture  10  to be easily mounted on the mounting portions  1 A of various sizes. 
     Accordingly, there is no need to make the plurality of space adjustment members  20  having the extension plates  23  of different lengths according to the sizes of the mounting portions  1 A. In detail, one space adjustment member  20  having the elastic contacting plate  24 ′ is detachably mounted onto the fixing plate  14  of the fixture  10 , thereby allowing the fixture  10  to be easily mounted on the mounting portions  1 A of various sizes. 
     Each first assembling bar  30  whose one end (lower end) is fitted by a given depth to one of the insertion pipes  15  of the fixture  10  in such a manner as to be erected vertically. 
     As shown in  FIG. 11 , the first assembling bar  30  is formed of a pipe of a given length having a plurality of height adjusting holes  31  spaced apart from each other by a given distance on the upper outer periphery thereof in an up and down direction. 
     A fixing pin P is penetratedly inserted into one selected from the height adjusting holes  31 , and as shown in  FIG. 12 , the second assembling bars  40  as will be discussed later fixedly inserted into the upper ends of the first assembling bars  30  can be appropriately adjusted in height. 
     One end of the second assembling bar  40  is fixedly fitted to the upper end of the first assembling bar  30 , and the other end thereof is fitted to the horizontal connecting bar  50  as will be discussed later, so that an upper portion of the rack structure is formed, thereby making it possible to laminate a plurality of rack structures onto top of each other up and down. 
     As shown in  FIG. 13 , the second assembling bar  40  includes a vertical portion  41  having one end fitted to the upper end of the first assembling bar  30  and the other end of a given length in a vertical direction and a horizontal portion  42  having one end fitted to the upper end of the vertical portion  41  and the other end of a given length in a horizontal direction, so that the second assembling bar  40  has a shape of a general “ ” or inverse “ ”. 
     The vertical portion  41  and the horizontal portion  42  have through holes  41 A and  42 A of given sizes, and through the through holes  41 A and  42 A, the fixing pins P inserted into the height adjusting hole  31  and a distance adjusting hole  51 A as will be discussed later are passed through the second assembling bar  40 , thereby allowing the second assembling bar  40  to be rigidly fixed to the first assembling bar  30  and the horizontal connecting bar  50 . 
     The horizontal connecting bars  50  serve to connect the horizontal portions  42  of the second assembling bars  40  thereto. 
     As shown in  FIG. 14 , the horizontal connecting bar  50  includes a connecting bar body  51  formed of a circular pipe of a given length in a horizontal direction in such a manner as to fit the horizontal portions  42  of the second assembling bars  40  to both ends thereof and a crossing portion  52  formed of a groove of a given size on the center of the connecting bar body  51  in such a manner as to be crossingly laminated on top of another horizontal connecting bar  50  to a shape of “X” on the same height as each other. 
     Further, the horizontal connecting bar  50  includes the distance adjusting holes  51 A penetratedly formed on both sides of the connecting bar body  51  around the crossing portion  52  in such a manner as to be spaced apart from each other by a given distance, and the fixing pin P is inserted into one of the distance adjusting holes  51 A like the height adjusting holes  31 , so that as shown in  FIG. 15 , positions where the horizontal portions  42  of the second assembling bars  40  are insertedly fixed to the horizontal connecting bars  50  are adjusted to allow the width of the rack structure to be adjusted. 
     Hereinafter, an explanation on use examples of the prefabricated pallet rack structure capable of being adjusted in width and height according to the present invention will be given. 
     If the rack structure is built on the pallet  1 , the space adjustment member  20  having the extension plates  23  of appropriate lengths is selected and coupled to the fixing plate of the fixture  10  according to the size of the mounting portion  1 A of the pallet  1 , so that the fixtures  10  on which the space adjustment members  20  are mounted are coupled to the four mounting portions  1 A formed on the corners of the pallet  1 . 
     Next, the four first assembling bars  30  are inserted into the insertion pipes  15  of the fixtures  10 , and the vertical portions  41  of the second assembling bars  40  are fixedly fitted by a given depth to the upper ends of the first assembling bars  30 . 
     After that, one pair of horizontal connecting bars  50  is coupled to the four second assembling bars  40  in such a manner as to allow the horizontal portions  42  of the second assembling bars  40  to have a shape of “X”. 
     On the other hand, if it is desired to adjust the height of the rack structure in the state where the rack structure is built on the pallet  1 , the fixing pins P inserted into the height adjusting holes  31  of the first assembling bars are removed, and next, the second assembling bars  40  are raised appropriately to a desired height. In this state, the fixing pins P are insertedly passed through the height adjusting holes  31  and the through holes  41 A, thereby adjusting installation heights of the second assembling bars  40  to the desired height. 
     If it is desired to adjust the width of the rack structure, further, the positions of the first assembling bars  30  inserted into the insertion pipes  15  have to be first adjusted, and after the first assembling bars  30  inserted into one side insertion pipes  15  are removed sequentially from the insertion pipes  15 , accordingly, they are inserted into the insertion pipes  15  located at another position. At this time, the fixing pins P inserted into the horizontal connecting bars  50  are first removed so as to perform the work for adjusting the width of the rack structure. 
     Next, the horizontal portions  42  of the second assembling bars  40  inserted into the horizontal connecting bars  50  are appropriately adjusted in distance, and the fixing pins P are inserted into the distance adjusting holes  51 A and the through holes  42 A sequentially, thereby adjusting the width of the rack structure. 
     On the other hand, as mentioned above, the insertion pipes  15  are spaced apart from each other by a given distance, but as shown in  FIG. 16 , one insertion pipe  15  can be adjusted appropriately in position along horizontal long holes H 1  formed on the support plates  16 . 
     At this time, a plurality of locking grooves H 2  is formed along the horizontal long holes H 1 , and through the formation of the locking grooves H 2 , accordingly, the insertion pipe  15  can be easily adjusted horizontally in position. 
     Further, the insertion pipe  15  has a locking pin  15 A formed on an outer peripheral surface thereof in such a manner as to be selectively inserted into the locking grooves H 2  and to be thus fixed in position, and the locking pin  15 A has a screw thread (not shown) formed along the outer periphery thereof so that in a state where the insertion pipe  15  is appropriately adjusted in position by means of the horizontal long holes H 1  and the locking grooves H 2 , a nut is screw-coupled to the locking pin  15 A to allow the position of the insertion pipe  15  to be rigidly fixed. 
     Under the above-mentioned configuration, even if the first assembling bars  30  are separated from the insertion pipes  15  so as to adjust the width of the rack structure, the installation positions of the insertion pipes  15  can be easily changed through the horizontal long holes H 1  and the locking grooves H 2  in the state where the first assembling bars  30  are inserted into the insertion pipes  15 , thereby more easily adjusting the width of the rack structure. 
     As mentioned above, the other end of the second assembling bars  40  is inserted into both ends of the horizontal connecting bars  50  crossing to the shape of “X”, thereby adjusting the width of the rack structure. Unlike the above-mentioned configuration, the horizontal portions  42  cross to the shape of “X” in such a manner as to allow the front end of the other side horizontal portion  42  to be fitted by a given length to the front end of one side horizontal portion  42 , so that they can be connected horizontally to each other. 
     At this time, one side horizontal portion  42  has a connecting portion  42 B formed on the front end thereof in such a manner as to have a relatively larger or smaller diameter than the front end of the other side horizontal portion  42 , and accordingly, the front end of the other side horizontal portion is fitted by a given length to the connecting portion  42 B. Otherwise, the connecting portion  42 B is fitted by a given length to the front end of the other side horizontal portion  42 . As a result, the width of the rack structure can be appropriately adjusted. 
     Further, through holes  41 A and  42 A are spaced apart from each other by a given distance on the front ends of the connecting portion  42 B and the other side horizontal portion  42 , and the width adjusted by means of the through holes  41 A and  42 A is fixed by means of the fixing pin P in the same manner as the horizontal connecting bars  50 . 
     As described above, the prefabricated pallet rack structure according to the present invention can be built on the pallets having various sizes only if the space adjustment members of appropriate sizes are mounted onto the fixtures. In addition, the rack structure according to the present invention can easily adjust the width thereof just through changes in positions of the first assembling bars inserted into the insertion pipes if goods have a larger width than the pallet. Further, the rack structure according to the present invention can easily adjust the heights of the second assembling bars fixedly fitted to the first assembling bars by means of the fixing pins. 
     The present invention may be modified in various ways and may have several exemplary embodiments. Specific exemplary embodiments of the present invention are illustrated in the drawings and described in detail in the detailed description. However, this does not limit the invention within specific embodiments and it should be understood that the invention covers all the modifications, equivalents, and replacements within the idea and technical scope of the invention. 
     
       
         
           
               
               
             
               
                   
               
             
            
               
                 1: pallet 
                 1A: mounting portion 
               
               
                 1B: forkbar insertion hole 
                 10: fixture 
               
               
                 11: lower plate 
                 11A: extension plate 
               
               
                 12: first side plate 
                 13: second side plate 
               
               
                 14: fixing plate 
                 14A: fitting slots 
               
               
                 15: insertion pipes 
                 15A: locking pin 
               
               
                 16: support plates 
                 17: reinforcing plates 
               
               
                 20: space adjustment members 
                 21: first locking plate 
               
               
                 21A: fitting portions 
                 22: second locking plate 
               
               
                 23: extension plates 
                 24: contacting plate 
               
               
                 24′: elastic contacting plate 
                 30: first assembling bar 
               
               
                 31: height adjusting holes 
                 40: second assembling bars 
               
               
                 41: vertical portion 
                 41A: through holes 
               
               
                 42: horizontal portion 
                 42A: through holes 
               
               
                 42B: connecting portion 
                 50: horizontal connecting bars 
               
               
                 51: connecting bar body 
                 51A: distance adjusting hole 
               
               
                 52: crossing portion 
                 CP: center point of insertion hole 
               
               
                 DL: virtual diagonal line 
                 P: fixing pins 
               
               
                 H1: horizontal long holes 
                 H2: locking grooves