Patent Publication Number: US-9833821-B2

Title: Roll forming device for forming variable thickness plate

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Korean Patent Application No. 10-2015-0188971 filed in the Korean Intellectual Property Office on Dec. 29, 2015, 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 roll forming device for forming a variable thickness plate. More particularly, the present invention relates to a roll forming device for forming a variable thickness plate in which an initial gap between an upper forming roll and a lower forming roll, which are disposed on a forming device, is set, and a spring unit absorbs a forming reaction force that is applied to the upper forming roll depending on a material thickness to be able to control a gap between the upper forming roll and the lower forming roll in real time. 
     (b) Description of the Related Art 
     Generally, forming of a line-type beam is performed by a roll forming system in which at least ten roll forming devices having an upper forming roll and a lower forming roll are disposed in line to bend and form supplied material into various shapes. 
       FIG. 1  shows a roll forming device of a general roll forming system and processes for each step. 
     Referring to  FIG. 1 , the roll forming system and process include an uncoiling step S 110  in which an un-coiler  201  unfolding a supplied coil  200  is disposed at a front side of a process line, and a straightening step S 120  in which a straightener  203  straightening a band-type coil  200  unrolled from the un-coiler  201  to a flat steel plate  250  is disposed at a rear side thereof. 
     Further, a brake press  205  is disposed at a rear side of the straightener  203  and performs a piercing step S 130  to form various holes that are used to assemble a beam that is to be formed. 
     At least ten roll forming devices ( 207 : R 1 -R 7 ; partially not shown) are disposed at a rear side of the brake press  205  perform a roll forming step S 140 , which sequentially bends the steel plate  250  supplied through the un-coiler  201 , the straightener  203 , and the brake press  205 , to a beam having a desired shape. 
     A round bender  209  that has a plurality of curvature forming rolls, which are disposed along a radius of a curvature for forming a curvature of a roll forming product, is disposed at a rear side of the roll forming device  207 , and fabricates a predetermined curvature to perform a bending step S 150 . 
     However, in the conventional roll forming system, upper and lower forming rolls are is disposed at each roll forming device (R 1 -R 7 ), and when a material is inserted, a gap deviation is formed between the upper forming roll and the lower forming roll by a forming reaction force, or particularly, in a case that a thickness of the material such as a TWB (Tailor Weld Blank) or a TRB (Tailor Rolled Blank) is changed, there is a drawback that a forming pressure exceeds a predetermined range by a predetermined gap between the upper forming roll and the lower forming roll. 
     Particularly, it is difficult to control a gap between an upper forming roll and a lower forming roll when plates (TWB, TRB, and so on) having different thicknesses in a length direction are inserted in real time, because it is difficult to accurately control a gap by using a servo motor in real time, so left and right forming deviations are generated on the upper forming roll and the lower forming roll, and thus there is a problem that a defective product is formed by a distortion that is caused by a forming pressure difference. 
     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 a roll forming device for forming a variable thickness plate having advantages of controlling a gap between an upper forming roll and a lower forming roll in real time, wherein an initial gap is set between the upper forming roll and the lower forming roll that are disposed on each roll forming device of a roll forming system, and a spring unit absorbs a forming reaction force that is applied to the upper forming roll according to a material thickness. 
     A roll forming device for forming a variable thickness plate according to one or a plurality of exemplary embodiments may include both-side stand frames that are disposed at a left side and a right side on a process base at a predetermined distance from each other and in which a sliding groove is formed at a center portion in an up and down direction, a lower forming roll unit in which a lower forming roll is fixed on a lower rotation shaft such that both end portions are rotatably disposed on a lower sliding block that is fixed to a lower portion of each sliding groove on the both-side stand frames, an upper forming roll unit in which an upper forming roll is fixed on an upper rotation shaft such that both end portions are rotatably disposed at an upper sliding block that is disposed on each sliding groove of the both-side stand frames to be slidably moved in an up and down direction at an upper portion of the lower forming roll unit, a forming roll gap adjustment unit that adjusts an initial gap between the lower forming roll and the upper forming roll, wherein a worm wheel and a worm gear are operated in an adjustment block of each upper portion of the both-side stand frames and an adjustment screw that is screw-engaged to a center of the worm wheel in an up and down direction adjusts an up-down direction position of the both-side upper sliding blocks, and a spring unit that is disposed between the adjustment screw and the upper sliding block within each sliding groove of the both-side stand frames, absorbs a forming reaction force that is applied to the upper forming roll according to a thickness variation of a plate that is to be formed, and simultaneously maintains a forming pressure of the upper forming roll within a predetermined range. 
     A scale may be disposed at one side of the both-side stand frames respectively corresponding to the lower sliding block and the upper sliding block, and a scale needle may be disposed at one side of each of the lower sliding block and the upper sliding block corresponding to each scale. 
     A rib may be formed at one side of each of the both-side stand frames so as to reinforce stiffness. 
     The lower forming roll unit may include both-side lower sliding blocks that are fixed to a lower portion of each sliding groove on the both-side stand frames, a lower rotation shaft of which both end portions are rotatably disposed on the both-side lower sliding blocks through a bearing, and a lower forming roll that is disposed at a center of the lower rotation shaft through key engagement between the both-side stand frames through both-side collar rings and that rotates together with the lower rotation shaft. 
     The upper forming roll unit may include both-side upper sliding blocks that are disposed on each sliding groove of the both-side stand frames to be able to slide in an up and down direction at an upper portion of the both-side lower sliding blocks, an upper rotation shaft of which both end portions are rotatably disposed on the both-side upper sliding blocks through a bearing, and an upper forming roll that is key-engaged with a center of the upper rotation shaft between the both-side stand frames through the both-side collar rings and rotates together with an upper rotation shaft to form a predetermined gap with the lower forming roll. 
     The forming roll gap adjustment unit may include both-side adjustment blocks that are fixed to each upper portion of the both-side stand frames and in which a space portion is respectively formed, a worm wheel that is disposed in each space portion of the both-side adjustment blocks and is able to rotate through a bearing, a worm gear that is respectively fixed on an adjustment shaft penetrating the both-side adjustment blocks in a lateral direction and is engaged with the worm wheel in each space portion of the both-side adjustment blocks, and an adjustment screw that is screw-engaged with each worm wheel in the both-side adjustment blocks and of which a lower end thereof is connected to the spring unit through a rotation body. 
     Each upper side of the both-side adjustment blocks may be opened, and a cover may cover the opened portion. 
     The spring unit may include a support block that is fixed to an upper surface of the upper sliding block in each sliding groove of the both-side stand frames, a spring housing that is fixedly engaged with an upper portion of the support block, an upper surface of which is opened, and that forms a receiving space portion together with the support block, a retainer that is disposed at an upper portion at an inside of a receiving space portion of the spring housing, an upper end of which is connected to a lower end of the adjustment screw through a rotation body, and in which a spring guider is formed at a center of a lower surface thereof, and a plurality of disk springs that are disposed inside a receiving space portion of the spring housing to be engaged with a spring guider of the retainer in a crisscross manner and offers elastic force between the retainer and the support block. 
     The roll forming device may further include a space ring that is engaged with the spring guider between the support block and a disk spring to vary elastic force of an entire disk spring. 
     In an exemplary embodiment of the present invention, an initial gap is set between an upper forming roll and a lower forming roll that are disposed on each roll forming device of a roll forming system, a spring unit absorbs a forming reaction force that is applied to an upper forming roll depending on a material thickness, and a gap between an upper forming roll and a lower forming roll is accurately controlled in real time to prevent a gap deviation between a left and a right thereof according to a material thickness. 
     Accordingly, a forming pressure is uniformly maintained within a predetermined range and an up and down direction position of an upper forming roll is adjusted to enable a variable plate to be roll-formed, and thus a variation of roll forming can be optimized and a distortion generated by a variation of a forming pressure is prevented to improve an appearance quality. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a roll forming device of a general roll forming system and processes for each step. 
         FIG. 2  is a front view of a roll forming device according to an exemplary embodiment of the present invention. 
         FIG. 3  is a cross-sectional side view of a roll forming device according to an exemplary embodiment of the present invention. 
         FIG. 4  is an enlarged cross-sectional view of a spring unit that is applied to a roll forming device according to an exemplary embodiment of the present invention. 
         FIG. 5  is an operation state diagram of a roll forming device according to an exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Hereinafter, an exemplary embodiment of the present invention will be described in detail with reference to accompanying drawings. 
     The size and thickness of each component shown in the drawings are arbitrarily shown for better understanding and ease of description, but the present invention is not limited thereto, and the thickness of parts, regions, etc., are exaggerated for clarity. 
     Also, in order to clarify an exemplary embodiment of the present invention, parts that are not related to the description are omitted. 
       FIG. 2  is a front view of a roll forming device according to an exemplary embodiment of the present invention, and  FIG. 3  is a cross-sectional side view of a roll forming device according to an exemplary embodiment of the present invention. 
     Referring to  FIG. 2  and  FIG. 3 , a roll forming device according to an exemplary embodiment of the present invention includes both-side stand frames  10 , a lower forming roll unit  20 , an upper forming roll unit  30 , a forming roll gap adjustment unit  40 , and a spring unit  50 . 
     Firstly, the both-side stand frames  10  are disposed at a left side and a right side on a process base (not shown) at a predetermine distance from each other, and a sliding groove (G) is formed at each center portion in the up-down direction. 
     A rib (L) is formed at both sides of each inner side and outer side of the both-side stand frames  10  so as to reinforce supporting stiffness. 
     In the lower forming roll unit  20 , a lower sliding block  21  is respectively fixed at a lower portion of each sliding groove (G) on the both-side stand frames  10 , both end portions of a lower rotation shaft  23  are rotatably disposed at both sides of the lower sliding block  21 , and a lower forming roll  25  is fixed on the lower rotation shaft  23 . 
     To describe the lower forming roll unit  20  in detail, respective sides of the lower sliding block  21  are fixed to lower portions of each sliding groove (G) on the both-side stand frames  10 . 
     Both end portions of the lower rotation shaft  23  are rotatably disposed in both sides of the lower sliding block  21  through a bearing (B). 
     Also, the lower forming roll  25 , which is disposed at a center of the lower rotation shaft  23  to be engaged by a key between the both-side stand frames  10  and between both-side collar rings  27  that are inserted into both sides of the lower rotation shaft  23 , is configured to rotate together with the lower rotation shaft  23 . 
     In this condition, the lower forming roll  25  is disposed on a center of the lower rotation shaft  23  to be supported by both side collar rings  27 . 
     The upper forming roll unit  30  is disposed at an upper portion of the lower forming roll unit  20 , respective sides of an upper sliding block  31  are disposed at each sliding groove (G) on the both-side stand frames  10  to be slidably moved in an up and down direction, both end portions of an upper rotation shaft  33  are rotatably disposed on both sides of the sliding block  31 , and an upper forming roll  35  is fixed on the upper rotation shaft  33 . 
     More specifically, for the upper forming roll unit  30 , respective sides of the upper sliding block  31  are disposed at each sliding groove (G) on the both-side stand frames  10  to be slidably moved in an up and down direction above both sides of the lower sliding block  21 . 
     Both end portions of the upper rotation shaft  33  are rotatably disposed inside both sides of the upper sliding block  31  through a bearing (B). 
     Also, the upper forming roll  35 , which is disposed at a center of the upper rotation shaft  33  to be engaged by a key between both-side stand frames  10  and between both side collar rings  37  that are inserted into both sides of the upper rotation shaft  33 , is configured to rotate together with the upper rotation shaft  33 . In this condition, the upper forming roll  35  is disposed on a center of the upper rotation shaft  33  to be supported by both-side collar rings  37 , and the upper forming roll  35  forms an initial gap (T 1 ) with the lower forming roll  25 . 
     Here, a scale  11  is disposed at on side of a stand frame  10  to be extended in an up and down direction corresponding to the lower sliding block  21  and the upper sliding block  31 , and a scale needle  13  is disposed at one side of the lower sliding block  21  and the upper sliding block  31  corresponding to the scale  11 . 
     The scale  11  and the scale needle  13  are used as a base for adjusting a position and gap of the lower forming roll  25  and the upper forming roll  35 . 
     Further, in the forming roll gap adjustment unit  40 , a worm wheel  43  and a worm gear  45 , which are disposed inside an adjustment block  41  of each upper portion of the both-side stand frames  10 , are operated, and an adjustment screw  47  that is screw-engaged with a center of the worm wheel  43  to be extended in an up and down direction adjusts a vertical position of both sides of the upper sliding block  31  to be able to adjust the initial gap T 1  between the lower forming roll  25  and the upper forming roll  35 . 
     In more detail, the both-side adjustment blocks  41  are fixed at each upper portion of the both-side stand frames  10 , and a space portion (S) is formed in the forming roll gap adjustment unit  40 . 
     Here, an upper portion of the both-side adjustment block  41  is opened, and a cover (C) is engaged with the opened portion to cover the space portion (S). 
     The worm wheel  43  is disposed in each space portion (S) of the both-side adjustment block  41  and is disposed in a lateral direction to rotate through a bearing (B). 
     Also, in a condition in which the worm gear  45  is engaged with the worm wheel  43  in each space portion (S) of the both-side adjustment block  41 , the worm gear  45  is fixed on an adjustment shaft  49  to penetrate the both-side adjustment block  41  in a lateral direction. 
     Also, the adjustment screw  47  is screw-engaged with each worm wheel  43  to penetrate a center thereof in an up and down direction inside the both-side adjustment block  41 , and a lower end of the adjustment screw  47  is connected to the spring unit  50  through a rotation body (R). 
       FIG. 4  is an enlarged cross-sectional view of a spring unit that is applied to a roll forming device according to an exemplary embodiment of the present invention. 
     The spring unit  50  that is disposed inside each sliding groove (G) of the both-side stand frames  10  between the adjustment screw  47  and the upper sliding block  31  absorbs a forming reaction force that is applied to the upper forming roll  35 , and simultaneously maintains a forming pressure of the upper forming roll  35  within a predetermined range in real time according to a thickness of a plate, wherein the thickness is different in a length direction. 
     Referring to  FIG. 4 , in more detail, the spring unit  50  includes a support block  51 , a spring housing  53 , a retainer  55 , a disk spring  57 , and a space ring  59 . 
     The support block  51  is integrally fixed on an upper surface of the upper sliding block  31  inside each sliding groove (G) of the both-side stand frames  10 . 
     The spring housing  53  is engaged with an upper portion of the support block  51 , and an upper portion thereof is opened to form a receiving space portion (SP) together with the support block  51 . 
     Also, the retainer  55  is disposed at an opened upper portion of the receiving space portion (SP) of the spring housing  53  to be supported in an upper direction. An upper end of the retainer  55  is connected to a lower end of the adjustment screw  47  through the rotation body (R), and a spring guider  56  is formed at a center of a lower surface thereof. 
     Also, a plurality of the disk springs  57  are disposed inside a receiving space portion (SP) of the spring housing  53 , and are engaged with the spring guider  56  of the retainer  55  in a crisscross manner to offer elastic force between the retainer  55  and the support block  51 . 
     The space ring  59  is disposed between the support block  51  and the disk spring  57 , and the space ring  59  is engaged with the spring guider  56  to be able to adjust the number of disk springs  57  such that elastic force thereof can be varied. 
       FIG. 5  is an operation state diagram of a roll forming device according to an exemplary embodiment of the present invention. 
     Hereinafter, referring to  FIG. 3  and  FIG. 5 , an operation of a roll forming device for forming a variable thickness plate having the above configuration will be described. 
     Firstly, as shown in  FIG. 3 , an upper forming roll  35  and a lower forming roll  25  that are disposed at each roll forming device of a roll forming system sets an initial gap T 1  by a forming roll gap adjustment unit  40 . 
     That is, if an operator controls both side worm gears  45  through an adjustment shaft  49 , both side worm wheels  43  engaged with both side worm gears  45  are rotated, each adjustment screw  47  that is engaged with a center of each worm wheel  43  moves upward or downward depending on a rotation direction of each worm wheel  43  to minutely move both side upper sliding blocks  31  of an upper forming roll unit  30 , which is connected by each spring unit  50 , in an up and down direction, and an up and down direction position of an upper forming roll  35  based on the lower forming roll  25  is varied to set an initial gap T 1  between forming rolls. 
     In this condition, as shown in  FIG. 5 , a plate that has a variable thickness in a length direction, particularly, TWB, TRB, and so on, is inserted in a process direction, the plate is formed by an upper forming roll  35  and a lower forming roll  25 , if a part where a thickness of a plate is thick is interposed between the upper forming roll  35  and the lower forming roll  25 , a spring unit  50  absorbs a forming reaction force (F) depending on the thickness of the plate through the upper forming roll  35 . 
     That is, an upper forming roll  35  compresses a plurality of disk springs  57  of a spring unit  50  depending on a thickness of a plate, and an initial gap T 1  between a lower forming roll  25  and a upper forming roll  35  is adjusted to a fine adjustment gap T 2  to absorb a forming reaction force (F) depending on a thickness of a plate. 
     In this condition, a forming reaction force (F) of an upper forming roll  35  is input into a support block  51  through an upper sliding block  31 , and a support block  51  compresses a plurality of disk springs  57  that are disposed between a retainer  55  to be minutely moved upward by a varied thickness of the plate together with a spring housing  53  such that an upper forming roll unit  30  is minutely moved upward based on a lower forming roll unit  20  to absorb a forming reaction force (F). 
     Also, because elastic force of each disk spring  57  of the spring unit  57  is set to uniformly maintain a forming pressure of an upper forming roll  35  to a lower forming roll  25 , there is no problem for forming a plate. 
     As described above, a roll forming device for forming a variable thickness plate according to an exemplary embodiment of the present invention uses a spring unit  50  to absorb a forming reaction force (F) according to a thickness variation of a plate, accurately controls an initial gap T 1  to a fine adjustment gap T 2  between an upper forming roll  35  and a lower forming roll  25  in real time, prevents a gap deviation of a left side and a right side depending on a thickness variation of a plate, and accordingly, a roll forming variation amount can be optimized and a distortion of a final formed beam can be prevented by maintaining a forming pressure, while a plate of which the thickness is different in a length direction is being roll-formed. 
     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. 
     DESCRIPTION OF SYMBOLS 
     
         
           10 : stand frame 
           11 : scale 
           13 : scale needle 
           20 : lower forming roll unit 
           21 : lower sliding block 
           23 : lower rotation shaft 
           25 : lower forming roll 
           27 : collar ring 
           30 : upper forming roll unit 
           31 : upper sliding block 
           33 : upper rotation shaft 
           35 : upper forming roll 
           37 : collar ring 
           40 : forming roll gap adjustment unit 
           41 : adjustment block 
           43 : worm wheel 
           45 : worm gear 
           47 : adjustment screw 
           49 : adjustment shaft 
           50 : spring unit 
           51 : support block 
           53 : spring housing 
           55 : retainer 
           56 : spring guider 
           57 : disk spring 
           59 : space ring 
         G: sliding groove 
         L: rib 
         B: bearing 
         T 1 : initial gap 
         T 2 : fine adjustment gap 
         S: space portion 
         SP: receiving space portion 
         C: cover 
         R: rotation body