Patent Publication Number: US-7587920-B2

Title: Hydro forming apparatus for making U-shaped products

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Korean Patent Application No. 10-2006-0110043 filed in the Korean Intellectual Property Office on Nov. 8, 2006, the entire contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     (a) Field of the Invention 
     The present invention relates to a hydro forming apparatus for making U-shaped products. More particularly, the present invention relates to a hydro forming apparatus for making U-shaped products, which can adjust a shape of bent tube thereby improving product quality. 
     (b) Background 
     Referring to  FIG. 10 , a process for making U-shaped products will be described in detail. 
     As shown in  FIG. 10 , after a tube is bent into a U-shaped tube, the U-shaped tube is free formed into a rough U-shaped product. After that, a hydro forming process is performed by applying hydraulic pressure to the free formed U-shaped tube and a U-shape product is made by cutting ends of the tube. 
     In a case that a tube is bent into a U-shaped tube, the bent tube tends to restore its original shape to some degree, instead of maintaining its bent shape. This phenomenon is called spring back. For this reason, the bent tube should be further bent so as to complete a bending process. If a bent tube that does not undergo such adjusting process is inserted in a hydro forming apparatus, as shown in  FIG. 11 , pinching may occur and production quality may be deteriorated. 
     The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. 
     SUMMARY OF THE INVENTION 
     The present invention has been made in an effort to provide an improved hydro forming apparatus that can adjust the shape of a bent tube before hydro forming the tube. 
     In one aspect, the present invention provides a hydro forming apparatus comprising: a lower base; a lower mold mounted on the lower base and provided with an U-shaped lower cavity; an upper mold provided with a U-shaped upper cavity corresponding to the lower cavity and configured to be coupled with the lower mold; an upper base mounted on the upper mold and configured to be coupled with the lower base; and an adjusting unit for adjusting the shape of the U-shaped lower and upper cavities. 
     The adjusting unit may preferably include a first adjusting unit for adjusting ends of the U-shaped lower and upper cavities; and a second adjusting unit for adjusting side portions of the U-shaped lower and upper cavities. 
     The first and second adjusting units may respectively include an adjusting bolt and a push rod configured to be screwed to the adjusting bolt. 
     A lower plate may be disposed between the lower base and the lower mold, and an upper plate may be disposed between the upper base and the upper mold. 
     The lower and upper plates may be respectively divided into two pieces and each piece may be rotatably connected to the lower and upper bases. 
     Each piece of the lower and upper plates may be hinged to the lower and upper bases, respectively. 
     A first position checking pin may be mounted on the lower plate and be coupled with the upper plate through an end of the lower cavity. 
     A second position checking pin may be mounted on the upper plate, and one end of the second position checking pin may be connected to a side portion of the upper cavity. 
     The other end of the second position checking pin may penetrate through the upper base. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing a lower base and a lower mold coupled with each other according to an exemplary embodiment of the present invention. 
         FIG. 2  is a perspective view showing a lower base of a hydro forming apparatus for making U-shaped products according to an exemplary embodiment of the present invention. 
         FIG. 3  is a perspective view showing a lower plate of a hydro forming apparatus for making U-shaped products according to an exemplary embodiment of the present invention. 
         FIG. 4  is a perspective view showing a lower mold of a hydro forming apparatus for making U-shaped products according to an exemplary embodiment of the present invention. 
         FIG. 5  is a perspective view showing an upper base and an upper mold coupled with each other according an exemplary embodiment of the present invention. 
         FIG. 6  is a perspective view showing an upper base of a hydro forming apparatus for making U-shaped products according to an exemplary embodiment of the present invention. 
         FIG. 7  is a perspective view showing an upper plate of a hydro forming apparatus for making U-shaped products according to an exemplary embodiment of the present invention. 
         FIG. 8  is a perspective view showing an upper mold of a hydro forming apparatus for making U-shaped products according to an exemplary embodiment of the present invention. 
         FIG. 9  is a perspective view showing upper and lower molds and upper and lower plates assembled with each other according to an exemplary embodiment of the present invention. 
         FIG. 10  is a schematic diagram showing a process for making U-shaped products. 
         FIG. 11  is a schematic diagram showing problems occurred in a process for making U-shaped products. 
     
    
    
     Reference numerals set forth in the Drawings includes reference to the following elements as further discussed below: 
     
       
         
           
               
               
               
             
               
                   
                   
               
             
            
               
                   
                 100: lower base 
                 200: lower plate 
               
               
                   
                 300: lower mold 
                 400: upper mold 
               
               
                   
                 500: upper plate 
                 600: upper base 
               
               
                   
                   
               
            
           
         
       
     
     DETAILED DESCRIPTION 
     An exemplary embodiment of the present invention will hereinafter be described in detail with reference to the accompanying drawings. 
     As discussed above, in one aspect, the present invention provides a hydro forming apparatus for making U-shape products, comprising: a lower base; a lower mold mounted on the lower base and provided with an U-shaped lower cavity; an upper mold provided with a U-shaped upper cavity corresponding to the lower cavity and configured to be coupled with the lower mold; an upper base mounted on the upper mold and configured to be coupled with the lower base; and an adjusting unit for adjusting the shape of U-shaped lower and upper cavities 
       FIG. 1  is a perspective view showing a lower base and a lower mold coupled with each other, and  FIG. 5  is a perspective view showing an upper base and an upper mold coupled with each other according an exemplary embodiment of the present invention. 
     As shown in  FIG. 1  and  FIG. 5 , an exemplary hydro forming apparatus for making U-shaped products according to an embodiment of the present invention includes a lower base  100 , a lower plate  200 , a lower mold  300 , an upper mold  600 , an upper plate  500 , and an upper base  400 . 
     The lower mold  300  is mounted on the lower base  100 , and the lower plate  200  is disposed between the lower base  100  and the lower mold  300 . 
     The upper mold  600  is mounted under the upper base  400 , and the upper plate  500  is disposed between the upper base  600  and the upper mold  600 . 
     The lower mold  300  is coupled with the upper mold  600 , and the lower base  100  is coupled with the upper base  400 . 
     As shown in  FIG. 2 , the lower base  100  is provided with a first adjusting unit  130  and a hinge receiving groove  140 . 
     The first adjusting unit  130  includes an adjusting bolt  120  and push rods  110  connected to two sides of the adjusting bolt  120 . Each of the push rods  110  is configured to be screwed to the adjusting bolt  120 . Each of the push rods  110  can move outward of the adjusting bolt  120  or moves inward of the adjusting bolt  120  when the adjusting bolt  120  is rotated. 
     One end of a hinge shaft (not shown) is inserted in the hinge receiving groove  140 . 
     As shown in  FIG. 3 , the lower plate  200  is divided into two pieces, and each piece is rotatably connected to the lower base  100 . The lower plate  200  is provided with a first adjusting unit receiving groove  230 , a first position checking pin  220 , and a hinge insert hole  210 . 
     The push rod  110  of the first adjusting unit  130  is inserted in the first adjusting unit receiving groove  230  so that the push rod  110  may push the lower plate  200 . 
     In addition, the hinge insert hole  210  is formed at each piece of the lower plate  200 . The hinge shaft inserted in the hinge receiving groove  140  of the lower base  100  penetrates into the hinge insert hole  210 . In other words, each piece of the lower plate  200  is rotatably connected to the lower base  100  with reference to the hinge shaft. 
     As shown in  FIG. 4 , the lower mold  300  is provided with a lower cavity  310  and a position checking pin insert hole  320 . A forming surface is formed on the lower cavity  310 . The lower cavity  310  is substantially U-shaped such that a bent tube is inserted therein. The first position checking pin insert hole  320  is formed at ends of the U-shaped lower cavity  310 , and the first position checking pin  220  is configured to be coupled to the upper plate  500  through the first position checking pin insert hole  320 . 
     Therefore, when a user controls the first adjusting unit  130  and rotates each piece of the lower plate  200  with reference to the hinge shaft, the ends of the U-shaped lower cavity  310  can be rotated by the first position checking pin  220 , and accordingly, ends of the bent tube can be adjusted. 
     As shown in  FIG. 6 , the upper base  400  is provided with a hinge receiving groove  410  and a second position checking pin insert hole  450 . In addition, a second adjusting unit  440  is mounted on the upper base  400 . 
     The other end of the hinge shaft is to be inserted in the hinge receiving groove  410 . 
     The second adjusting unit  440  includes an adjusting bolt  430  and a push rod  420  connected to a side of the adjusting bolt  430 . Such second adjusting unit  440  is provided on left and right sides of the upper base  400 . 
     Each of the push rods  420  is configured to be screwed to the adjusting bolt  430 . Therefore, each of the push rods  420  can move outward of the adjusting bolt  430  or move inward of the adjusting bolt  430  when the adjusting bolt  430  is rotated. 
     As shown in  FIG. 7 , the upper plate  500  is divided into two pieces, and each piece is rotatably connected to the upper base  400 . The upper plate  500  is provided with a second adjusting unit receiving groove  510 , a hinge insert hole  520 , and a first position checking pin receiving groove  530 . In addition, a second position checking pin  540  is mounted on the upper plate  500 . 
     The second adjusting unit receiving grooves  510  are formed at left and right sides of the upper plate  500 , and the push rod  420  of the second adjusting unit  440  is to be inserted in the second adjusting unit receiving grooves  510 . 
     The hinge insert hole  520  is formed on each piece of the upper plate  500 . The other end of the hinge shaft, which penetrates the hinge insert hole  210  of the lower plate  200 , is inserted in the hinge receiving groove  410  of the upper base  400  through the hinge insert hole  520  of the upper plate  500 . Therefore, each piece of the upper plate  500  is rotatably connected to the upper base  400  with reference to the hinge shaft. 
     One end of the first position checking pin  220  mounted at the lower plate  200  is inserted in the first position checking pin receiving groove  530 . Therefore, the lower and upper plates  200  and  500  are simultaneously rotated by the first position checking pin  220 . 
     The second position checking pin  540  has one end inserted in the upper mold  600  and the other end penetrating the second position checking pin insert holes  450 . 
     As shown in  FIG. 8 , the upper mold  600  is provided with a U-shaped upper cavity  610  corresponding to the lower cavity  310  of the lower mold  300 . Second position checking pin receiving grooves  620  are formed at left and right sides of the U-shaped upper cavity  610 . The second position checking pin  540  is to be inserted in the second position checking pin receiving groove  620 . 
     When a user controls the second adjusting unit  440 , the push rod  420  of the second adjusting unit  440  pushes side portion of the upper cavity. Therefore, the side portion of the bent tube can be adjusted. In addition, the second position checking pin  540  inserted in the second position checking pin receiving groove  620  also moves and a user can check a shape of the side portion of the bent tube. 
     Hereinafter, an operation of the present invention will be described in detail. 
     As shown in  FIG. 9 , after a user uncouples the lower and upper bases  100  and  400  that are coupled with each other, a user rotates the adjusting bolt  120  of the first adjusting unit  130  and adjusts the shape of the ends of the U-shaped lower and upper cavities  310  and  610 . A user can check the shape of the ends of the lower and upper cavities  310  and  610  by the position of the first position checking pin  220 . 
     In addition, a user rotates the adjusting bolt  430  of the second adjusting unit  440  and adjusts the shape of the side portion of the U-shaped lower and upper cavities  310  and  610 . A user can check the shape of the side portion of the lower and upper cavities  310  and  610  by the position of the second position checking pin  540 . 
     After the shape of the lower and upper cavities  310  and  610  is adjusted, the lower and upper bases  100  and  400  are coupled with each other. After that, hydraulic pressure is applied to the U-shaped tube inserted in the lower and upper cavities  310  and  610  from a hydraulic pressure supplier (not shown) and a hydro forming process is completed. 
     According to the present invention, since a shape of a bent tube is easily adjusted and the adjusted tube undergoes a hydro forming process, product quality may be improved. 
     In addition, according to the present invention, since an additional adjusting process is not needed, working speed may be improved. 
     While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.