Patent Publication Number: US-2019185362-A1

Title: Bending device

Description:
TECHNICAL FIELD 
     The present invention relates to a bending device for bending a material to be bent such as a glass sheet. 
     BACKGROUND ART 
     In recent years, demand for a curved-surface display in which a display surface is curved has been increasing due to factors such as design appeal or a need to provide for curved-surface parts such as column-shaped parts and corners of cars. Liquid-crystal display panels are often used as this type of curved-surface display. 
     A liquid-crystal display panel for example includes: a glass substrate with a color filter, a counter electrode, and the like (CF substrate); a glass substrate with a plurality of pixel electrodes, thin-film transistors, and the like (TFT substrate): and a liquid-crystal layer enclosed between the CF substrate and the TFT substrate. When implementing a curved-surface display using a liquid-crystal display panel, bending is performed on the liquid-crystal display panel (glass substrates) so as to give the display panel a desired curvature. In this case, however, stress may be locally concentrated to damage the glass substrates. 
     For example, Patent Literature 1 discloses a bending device including an oven, a curving form, and a tempering section. The curving form has a plurality of curved rods, with each rod rising in an arrangement that is inclined at a predetermined angle relative to a horizontal plane. A glass sheet conveyed into the curving form is bent according to the inclination of the rods. The bent glass sheet then undergoes tempering. 
     CITATION LIST 
     Patent Literature 
     [Patent Literature 1] 
     Japanese Examined Patent Publication No. S62-022930 
     SUMMARY OF INVENTION 
     Technical Problem 
     However, the bending device according to Patent Literature 1 requires a heater to heat glass to a softening point and a metal mold to withstand high temperature, and is therefore a large-scale device. The bending device is also difficult to apply to mass-produced goods such as display panels due to an increase in volume of the processed glass in conveyance of the glass to an assembly section. 
     The present invention takes these circumstances into account and aims to provide a bending device of a simple configuration with which it is possible to perform bending processing on a material being bent while suppressing damage to the material being bent. 
     Solution to Problem 
     The bending device according to the present invention includes a base portion and a plurality of bend correction plates. The base portion has a movement surface on which a material to be bent is moved in a circumferential direction of the movement surface. The movement surface has an arcuate cross-section. The bend correction plates are arranged to face the movement surface with a predetermined distance therebetween and lined up side by side along a movement direction of the material to be bent. 
     Advantageous Effects of Invention 
     According to the present invention, a bending device of a simple configuration is provided with which it is possible to perform bending processing on a material being bent while suppressing damage to the material being bent. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic perspective view of a bending device according to a first embodiment. 
         FIG. 2  is a schematic side view of the bending device according to the first embodiment. 
         FIG. 3A  is a descriptive diagram for illustrating a method of bending a glass sheet P. 
         FIG. 3B  is a descriptive diagram for illustrating the method of bending the glass sheet P. 
         FIG. 3C  is a descriptive diagram for illustrating the method of bending the glass sheet P. 
         FIG. 4  is a schematic perspective view of a bending device according to a second embodiment. 
         FIG. 5  is a schematic sectional side view for illustrating pivoting of a bend correction plate with movement of a glass sheet P. 
         FIG. 6  is a schematic sectional side view of a bending device according to a third embodiment. 
         FIG. 7  is a schematic perspective view of the bending device according to the third embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     The following specifically describes embodiments of the present invention according to the accompanying drawings. 
     First Embodiment 
       FIG. 1  is a schematic perspective view of a bending device  1  according to a first embodiment.  FIG. 2  is a schematic side view of the bending device  1  according to the first embodiment. 
     The bending device  1  includes a base portion  11 , a plurality of bend correction plates  12 , and two side plates  14 . The base portion  11  has an arcuate cross-section. An outer circumferential surface of the base portion  11 , which is a surface having an arcuate cross-section, is a movement surface  11   a  on which a glass sheet P serving as a material to be bent is moved in a circumferential direction of the movement surface  11   a . The side plates  14  are respectively mounted on either side of the movement surface  11   a  in a width direction (direction intersecting with a movement direction D of the glass sheet P on the movement surface  11   a ) thereof. In  FIG. 1 , illustration of a side plate  14  on a near side in  FIG. 1  is omitted. 
     The bend correction plates  12  are arranged to face the movement surface  11   a  with a predetermined distance therebetween and lined up side by side along the movement direction D of the glass sheet P, which is the circumferential direction of the movement surface  11   a . Each bend correction plate  12  is a rectangular plate-shaped member that is elongated in one direction, and is arranged such that a longitudinal direction thereof corresponds to the width direction of the movement surface  11   a . A dimension of each bend correction plate  12  in the longitudinal direction thereof is substantially the same as a dimension of the movement surface  11   a  in the width direction thereof. The side plates  14  respectively support either end portion of each bend correction plate  12  in the direction intersecting the movement direction D, which is the longitudinal direction of the bend correction plate  12 . 
     The bend correction plate  12  has an edge portion (referred to as a first edge portion in the following)  121  upstream in the movement direction D and an edge portion (referred to as a second edge portion in the following)  122  downstream in the movement direction D. According to the present embodiment, the bend correction plate  12  is fixed to the side plates  14  in a state where the first edge portion  121  is more separated from the movement surface  11   a  than the second edge portion  122 . That is, the bend correction plate  12  is fixed to the side plates  14  in an inclined state such that the distance between the bend correction plate  12  and the movement surface  11   a  gradually becomes smaller from upstream to downstream in the movement direction D. 
     It is preferable to use highly rigid material in the base portion  11  and the bend correction plate  12 . It is also preferable for surfaces making contact with the glass sheet P, which are the movement surface  11   a  of the base portion  11  and a surface of the bend correction plate  12  (referred to as an opposing surface in the following) facing the movement surface  11   a , to be smooth. According to the present embodiment, bending is performed on the glass sheet P by inserting the glass sheet P so as to slide between the base portion  11  and the bend correction plate  12  and moving the glass sheet P between the base portion  11  and the bend correction plate  12  as illustrated in  FIG. 2 . 
       FIGS. 3A to 3C  are descriptive diagrams for illustrating a method of bending the glass sheet P. In  FIGS. 3A to 3C , a bend correction plate  12   a  is a bend correction plate  12  positioned upstream in the movement direction D, and a bend correction plate  12   b  is a bend correction plate  12  positioned downstream in the movement direction D. 
     When the glass sheet P is moved from a state illustrated in  FIG. 3A , the glass sheet P is kept pressed against the upstream bend correction plate  12   a  and a leading edge portion of the glass sheet P advances while touching the downstream bend correction plate  12   b  as illustrated in  FIG. 3B . As a result, a part of the glass sheet P passing beneath the bend correction plates  12   a  and  12   b  is bent by being pressed against the base portion  11  as illustrated in  FIG. 3C . As the glass sheet P advances, the glass sheet P is guided by the bend correction plates  12  and each part of the glass sheet P is gradually stressed and bent. Finally, the glass sheet P is deformed into a shape following the movement surface  11   a  by the entire glass sheet P passing the movement surface  11   a  of the base portion  11 . As such, deforming stress can be evenly dispersed and stress concentration on the glass sheet P can be avoided by performing bending with the bending device  1  according to the present embodiment. Therefore, damage to the glass sheet P when bending the glass sheet P can be suppressed. 
     Note that lengthwise and widthwise dimensions, inclining angle, and number of bend correction plates  12  can be set to various values. For example, in a configuration using nine bend correction plates  12  to bend a 1.2 m long glass sheet P, the bend correction plates  12  are fixed to the side plates  14  so that for example a central portion in the movement direction D of each bend correction plate  12  is separated from the base portion  11  by a distance of approximately 20 mm. In this case, the widthwise dimension of the bend correction plate  12  is for example 12 cm, and the lengthwise dimension of the bend correction plate  12  is for example 1 m. The bend correction plates  12  are also arranged with a distance of for example approximately 10 cm therebetween. 
     Second Embodiment 
     A bending device  21  according to a second embodiment has the same configuration as the bending device  1  according to the first embodiment aside from bend correction plates  12  being configured to be pivotable with centers thereof in a movement direction D as axes. 
       FIG. 4  is a schematic perspective view of the bending device  21  according to the second embodiment. Constituent elements shared with  FIGS. 1 and 2  are labeled with the same reference signs and detailed description thereof is omitted. 
     In the bending device  21  according to the present embodiment, each bend correction plate  12  has a pair of pivot plates  13 . The pivot plates  13  are respectively provided perpendicular to the bend correction plate  12  on either end portion of the bend correction plate  12  in a longitudinal direction (direction intersecting the movement direction D) of the bend correction plate  12 . A pin hole  13   a  (refer to  FIG. 5 ) is provided in a central portion of each pivot plate  13 . By inserting a pin  15  through the pin hole  13   a  of each pivot plate  13  with play from an outer side of each side plate  14 , the bend correction plate  12  is supported by the side plates  14  so as to be pivotable with the center thereof in the movement direction D as an axis. Therefore, the bend correction plate  12  is pivotable around the pins  15  in a first direction E 1  and a second direction E 2 . The first direction E 1  is a direction in which a first edge portion  121  of the bend correction plate  12  approaches the movement surface  11   a  and a second edge portion  122  of the bend correction plate  12  separates from the movement surface  11   a . The second direction E 2  is a direction in which the first edge portion  121  separates from the movement surface  11   a  and the second edge portion  122  approaches the movement surface  11   a.    
       FIG. 5  is a schematic sectional side view for illustrating the pivoting of the bend correction plate  12  with the movement of a glass sheet P. 
     According to the present embodiment, the first edge portion  121  is more separated from the movement surface  11   a  than the second edge portion  122  before the glass sheet P passes between the bend correction plate  12  and the movement surface  11   a  as illustrated in  FIG. 5 . When the glass sheet P passes between the bend correction plate  12  and the movement surface  11   a , a leading edge of the glass sheet P first makes contact with an opposing surface of the bend correction plate  12 . Thereafter, the bend correction plate  12  pivots in the first direction E 1  as the leading edge of the glass sheet P advances along the opposing surface of the bend correction plate  12 . Therefore, load on the glass sheet P from the bend correction plate  12  can be lessened, and the glass sheet P can be favorably deformed into a shape following the movement surface  11   a  while suppressing localized stress from being applied to the glass sheet P. Therefore, damage to the glass sheet P when bending the glass sheet P can be further suppressed. According to the present embodiment, stress is favorably reduced by the pivoting of the bend correction plate  12  even when a movement speed of the glass sheet P is increased. 
     Third Embodiment 
     A bending device  31  according to a third embodiment has the same configuration as the bending device  21  according to the second embodiment aside from that an inclining angle θ of each bend correction plate  12  with respect to a movement surface  11   a  (simply referred to as an inclining angle θ of the bend correction plate  12  in the following) can be set to a desired angle. 
       FIG. 6  is a schematic sectional side view of the bending device  31  according to the third embodiment.  FIG. 7  is a schematic perspective view of the bending device  31  according to the third embodiment. Constituent elements shared with  FIGS. 4 and 5  are labeled with the same reference signs and detailed description thereof is omitted. 
     The bending device  31  according to the present embodiment includes an inclining angle adjustment mechanism  18  for adjusting the inclining angle θ of the bend correction plate  12  to a desired angle. Note that in  FIG. 6 , the inclining angle θ of the bend correction plate  12  is shown as a reference of a tangent line L 3  at a point B. Herein, a point A is the center of a pin  15 , which is the center of a pivoting axis of the bend correction plate  12 , and the point B is an intersection of the movement surface  11   a  and a line passing though the point A and the center of an arc formed by the movement surface  11   a . A line L 1  passes through the point A and extends in the same direction as an opposing surface of the bend correction plate  12 . A line L 2  passes through the point A and is parallel to the tangent line L 3 . The inclining angle adjustment mechanism  18  includes a protrusion  16  provided on at least one of either end portion of the bend correction plate  12  in a longitudinal direction thereof, a guide hole  14   a  formed in at least one of a pair of side plates  14 , and a nut  17  (fastening member) which fixes pivoting of the bend correction plate  12  by being fastened to the protrusion  16 . 
     The protrusion  16  is provided on at least one of pivot plates  13  of the bend correction plate  12  so as to protrude outward. Specifically, the protrusion  16  is provided in a position near a first edge portion  121  or a second edge portion  122  on an outer surface (surface not facing another pivot plate  13 ) of one of the pair of pivot plates  13  so as to protrude perpendicularly outward from the surface. 
     The guide hole  14   a  is arcuate for example. The guide hole  14   a  receives insertion of the protrusion  16  and guides movement of the protrusion  16  as the bend correction plate  12  pivots. A plurality of guide holes  14   a  respectively corresponding to protrusions  16  of a plurality of bend correction plates  12  are formed in at least one of the side plates  14 . In a configuration in which a protrusion  16  is provided on one of each pair of pivot plates  13 , the guide holes  14   a  are formed in one of the side plates  14  that is located toward the pivot plate  13  provided with the protrusion  16 . In a configuration in which a protrusion  16  is provided on both of each pair of pivot plates  13  by contrast, the guide holes  14   a  are formed in both of the side plates  14 . 
     A tip of the protrusion  16  protrudes outward from the guide hole  14   a , and a male screw  16   a  is provided on a protruding part of the protrusion  16 . The pivoting of the bend correction plate  12  is fixed by fitting the nut  17  to the tip of the protrusion  16  inserted through the guide hole  14   a.    
     According to the present embodiment, the bend correction plate  12  is rotated around the pins  15  to a position that allows the inclining angle θ of the bend correction plate  12  to be a desired angle, with a base part of the protrusion  16  inserted through the guide hole  14   a . Thereafter, the bend correction plate  12  is fixed to a side plate  14  by fastening the nut  17  to the male screw  16   a . Therefore, in the bending device  31  according to the present embodiment, the inclining angle θ of each bend correction plate  12  can be easily set to a desired angle. 
     It should be noted here that the way that stress is applied to the glass sheet P when bending varies according to the inclining angle θ of the bend correction plate  12 . Also, rigidity of the glass sheet P varies according to thickness, size, or the like of the glass sheet P. Therefore, an optimal inclining angle θ of the bend correction plates  12  varies according to the type of the glass sheet P intended for bending. According to the present embodiment, however, the inclining angle θ of the bend correction plates  12  can be easily set to an optimal angle for the intended glass sheet P. 
     Note that the present embodiment is described using an example in which the protrusion  16  is fixed by the nut  17 . However, the present embodiment is not limited as such, and the protrusion  16  may be fixed by securing the base part of the protrusion  16  to the guide hole  14   a  after positioning the bend correction plate  12 . Another configuration is possible in which the base part of the protrusion  16  is not secured to the guide hole  14   a  but rather the base part of the protrusion  16  moves along the guide hole  14   a  with the pivoting of the bend correction plate  12 . 
     A number of embodiments of the present invention are described above. As such, a bending device  1  ( 21 ,  31 ) according to the embodiments includes a base portion  11  and a plurality of bend correction plates  12 . The base portion  11  has a movement surface  11   a  which is a surface having an arcuate cross-section. A material P to be bent is moved along the movement surface  11   a  in a circumferential direction of the movement surface  11   a . The bend correction plates  12  are arranged to face the movement surface  11   a  with a predetermined distance therebetween and lined up side by side along a movement direction D of the material P to be bent. 
     According to the above configuration, deforming stress applied to the material P to be bent when bending can be evenly dispersed, and stress concentration in a glass sheet P can be prevented. Therefore, damage to the material P to be bent when bending can be suppressed. Accordingly, in the bending device  1  according to the embodiments, bending can be performed while suppressing damage to the material P to be bent with a simple configuration such as the above. 
     In the bending device  1  according to the embodiments, a first edge portion  121  of each bend correction plate  12  upstream in the movement direction D may be more separated from the movement surface  11   a  than a second edge portion  122  of each bend correction plate  12  downstream in the movement direction D. 
     According to the above configuration, a leading edge of the material P to be bent can be easily inserted to slide between the movement surface  11   a  and a bend correction plate  12 . Therefore, it is possible to prevent a problem of damage being caused to the material P to be bent due to the material P to be bent hitting the first edge portion  121  of the bend correction plate  12  or the material P to be bent failing to slide between the movement surface  11   a  and the bend correction plate  12  and bending backward. 
     In the bending device  1  according to the embodiments, the bend correction plate  12  may be pivotable in a first direction E 1  and a second direction E 2 . The first direction E 1  is a direction in which the first edge portion  121  upstream in the movement direction D approaches the movement surface  11   a  and the second edge portion  122  downstream in the movement direction D separates from the movement surface  11   a.    
     The second direction E 2  is a direction in which the first edge portion  121  separates from the movement surface  11   a  and the second edge portion  122  approaches the movement surface  11   a.    
     According to the above configuration, load on the material P to be bent from the bend correction plate  12  can be lessened, and the material P to be bent can be favorably deformed into a shape following the movement surface  11   a  while suppressing localized stress from being applied to the material P to be bent. Therefore, damage to the material P to be bent when bending can be further suppressed. Also, stress is favorably reduced by the pivoting of the bend correction plate  12  even when the movement speed of the material P to be bent is increased. 
     In the bending device  1  according to the embodiments, the first edge portion  121  is more separated from the movement surface  11   a  than the second edge portion  122  before the material P to be bent passes between the bend correction plate  12  and the movement surface  11   a , and the bend correction plate  12  may pivot in the first direction E 1  when the leading edge of the material P to be bent passes between the bend correction plate  12  and the movement surface  11   a.    
     According to the embodiments, the bending device  1  may further include an inclining angle adjustment mechanism  18  for adjusting an inclining angle θ of the bend correction plate  12  with respect to the movement surface  11   a  to a desired angle. 
     According to the above configuration, the inclining angle θ of the bend correction plate  12  can be easily set to a desired angle. Therefore, the inclining angle θ of the bend correction plate  12  can be easily set to an optimal angle for the glass sheet P intended for bending. 
     According to the embodiments, the bending device  1  may further include a pair of side plates  14  respectively supporting either end portion of the bend correction plate  12  in a direction intersecting with the movement direction D such that the bend correction plate  12  is pivotable in the first direction E 1  and the second direction E 2 . The first direction E 1  is a direction in which the first edge portion  121  upstream in the movement direction D approaches the movement surface  11   a  and the second edge portion  122  downstream in the movement direction D separates from the movement surface  11   a . The second direction E 2  is a direction in which the first edge portion  121  separates from the movement surface  11   a  and the second edge portion  122  approaches the movement surface  111   a . The inclining angle adjustment mechanism  18  may include a protrusion  16 , a guide hole  14   a , and a fastening member  17 . The protrusion  16  is provided on at least one of the end portions of the bend correction plate  12  so as to protrude outward. The guide hole  14   a  is a hole formed in at least one of the side plates  14  for receiving insertion of the protrusion  16  and guiding the movement of the protrusion  16  as the bend correction plate  12  pivots. The fastening member  17  fixes the pivoting of the bend correction plate  12  by being fastened to the protrusion  16 . 
     According to the above configuration, the bend correction plate  12  is rotated with a center thereof in the movement direction D as an axis to a position that allows the inclining angle θ of the bend correction plate  12  to be a desired angle, with the protrusion  16  inserted through the guide hole  14   a . Thereafter, the bend correction plate  12  is fixed to side plate  14  by fastening the fastening member  17  to the protrusion  16 . Thus, the bend correction plate  12  can be favorably inclined. 
     Note that the presently disclosed embodiments are merely examples in all respects and should not be construed to be limiting. The scope of the present invention is indicated by the claims, rather than by the description given above, and includes all variations that are equivalent in meaning and scope to the claims. 
     REFERENCE SIGNS LIST 
     
         
           1 ,  21 ,  31  Bending device 
           11  Base portion 
           11   a  Movement surface 
           12  Bend correction plate 
           121  First edge portion 
           122  Second edge portion 
           13  Pivot plate 
           13   a  Pin hole 
           14  Side plate 
           14   a  Guide hole 
           15  Pin 
           16  Protrusion 
           16   a  Male screw 
           17  Nut 
           18  Inclining angle adjustment mechanism