Patent Publication Number: US-2017349472-A1

Title: Device for molding glass curved surface and method for molding glass curved surface by using same

Description:
TECHNICAL FIELD 
     Apparatuses and methods consistent with the present invention relate to an apparatus for molding curved glass and a method for molding curved glass using the same, and more particularly, an apparatus for molding curved glass and a method for molding curved glass using the same, for putting a plurality of mold units in which a flat glass is positioned into a heated chamber and then forming the glass with a curved surface via vacuum adsorption or compression. 
     BACKGROUND ART 
     An electronic device such as a mobile phone and a digital camera uses a liquid crystal display device or an organic light emitting diode (OLED) display device so as to allow a user to display a display unit. A transparent window glass is disposed in front of the display device. 
     Recently, as portable devices with a curved surface have been developed, there has increasingly been a need for a widow including a curved surface. In general, differently from plate glass products, curved glass products applied to various electronic products are manufactured by molding a plate glass, which is cut according to the standard of a curved shape of the product, via thermal deformation using a mold. 
     Conventionally, molding is performed only via press pressure in order to manufacture a curved glass and, thus, quality deviation occurs. In order to overcome this issue, a technology of manufacturing a curved glass using vacuum adsorption and heat has been developed but heat applied to a mold is not capable of being effectively controlled to cause product errors. 
     According to the conventional technology, a mold unit with a single cavity is permitted to pass between an upper heater unit and a lower heater unit and, thus, the productivity of curved glasses is not high. In addition, when a plurality of mold units are arranged in parallel, there is a problem in that the molding quality of a glass is not uniform due to a temperature difference between an end portion and a center portion of each heater unit. 
     DISCLOSURE 
     The present invention provides an apparatus for molding curved glass and a method for molding curved glass using the same, for manufacturing curved glass with high quality by controlling adsorptive power and heat step by step via adsorption and compression and for configuring a multi-cavity mold unit so as to reduce molding quality deviation for each cavity. 
     The present invention provides an apparatus for molding curved glass and a method for molding curved glass using the same, for minimizing an installation area and reducing installation costs by configuring mold physical distribution as a 2 column rotation structure. 
     According to an aspect of the present invention, an apparatus for molding curved glass includes a plurality of mold units formed as one or more cavities in a chamber for thermal molding and including a lower mold in which glass is put into each cavity and an upper mold corresponding to a shape of a glass to be processed and disposed on the lower mold, and first and second processing apparatuses each including an inlet part into which the plurality of mold units are put, a preheating part configured to heat the glass, a molding part configured to mold the glass, a cooling part configured to cool the glass molded in the molding part, and an outlet part from which the glass cooled by the cooling part is discharged, wherein the molding part gradually reduces a rate of increase of heat applied to the plurality of mold units toward the cooling part from the inlet part. 
     The molding part may include first fixing unit spaced apart below the plurality of mold units, and second fixing unit spaced apart above the plurality of mold units. 
     The first and second fixing units may each include a plurality of temperature control blocks, and the temperature control block may include at least one heating block configured to heat the plurality of mold units, at least one heat sink stacked on the heating block to contact the heating block, and at least one cooling block stacked on a plate and formed to lower temperature of the first and second fixing units. 
     A contact area of the plurality of heat sink with the heating block may be gradually increased toward the cooling part from the inlet part. 
     As the contact area of the plurality of heat sinks with the heating block is gradually increased, 
     The cooling block and the heating block may exchange heat and a rate of increase of temperature of the plurality of mold units in the chamber is gradually reduced toward the cooling part from the inlet part. 
     Each of the heat sinks may have a hollow portion with at least one polygon. 
     A straight line type protrusion may be periodically and repeatedly formed on upper portion and lower portion of each heat sink. 
     A suction passage connected to a vacuum suction device may be formed in the first fixing unit and the suction passage extends to a suction hole formed on an upper portion of the heating block of the first fixing unit. 
     The lower mold may include a suction flow path formed on a lower portion of the lower mold, and the plurality of mold units may perform vacuum adsorption on a lower portion of the glass for a predetermined time at a location corresponding to the suction flow path and the suction hole and, simultaneously, may compress an upper portion of the glass by self load of the upper mold and an upper heat unit. 
     The plurality of mold units may be molded in one heating block disposed in the molding part and then moved to the cooling part. 
     The plurality of mold units may be molded according to suction force that is differently controlled by a plurality of temperature control blocks disposed in the molding part. 
     The first and second processing apparatuses may be arranged in parallel. 
     Inert gas may be injected into the chamber to prevent the mold unit from being oxidized. 
     Opening and closing doors may be formed at opposite ends of the molding part in order to prevent the inert gas from leaking when the plurality of mold units are input or discharged. 
     Each of the temperature control blocks may further include at least one plate disposed between the heat sink and the cooling block. 
     The first and second processing apparatuses may be arranged to form a closed loop and constitute a 2 column rotation structure. 
     According to another aspect of the present invention, a method for molding curved glass includes putting glass into a plurality of mold units, preheating the glass, molding the heated glass, cooling the molded glass, and sequentially extracting the completely cooled glass from each of the mold units, wherein a rate of increase of heat applied to the plurality of mold units is adjusted by each stage. 
     The molding may include molding the glass via vacuum adsorption of a lower mold of the mold units, self load compression of an upper mold of the mold unit, and an upper heater unit. 
     According to another aspect of the present invention, an apparatus for molding curved glass including a plurality of mold units including lower molds including a plurality of molding rooms into which a glass is input and upper molds formed above the lower molds with pressure due to self load being applied to the glass as a thermal molding target; and a processing apparatus configured to sequentially move the plurality of mold units to be injected, preheated, cooled, and discharged and to adjust a rate of increase of heat applied to the plurality of mold units to the cooling from the preheating, wherein the lower molds are integrally formed and the upper molds are separately formed to correspond to respective molding rooms of the lower molds, and the upper molds may be spaced apart from each other by a preset interval. In this case, the processing apparatus may gradually reduce a rate of increase of heat toward the cooling from the preheating. 
     The processing apparatus may include lower heater units disposed below the plurality of mold units and upper heater units spaced apart above the plurality of mold units for thermal molding. 
     The upper heater units may be separately formed above the upper molds, respectively. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic plan view of an apparatus for molding curved glass according to an exemplary embodiment of the present invention. 
         FIG. 2  is a perspective view of a mold unit illustrated in  FIG. 1 . 
         FIG. 3A  is a cross-sectional view of a molding part illustrated in  FIG. 1 . 
         FIG. 3B  is an exploded perspective view of a first temperature control block illustrated in  FIG. 3A . 
         FIG. 4  is a plan view in which a shape of a heat sink is varied according to an exemplary embodiment of the present invention. 
         FIG. 5  is a cross-sectional view of a mold unit that enters a molding part according to an exemplary embodiment of the present invention. 
         FIG. 6  is a cross-sectional view of a mold unit in which glass molding is completed according to an exemplary embodiment of the present invention. 
         FIG. 7  is a cross-sectional view of a first modified example of a mold unit and an upper heater unit according to an exemplary embodiment of the present invention. 
         FIG. 8  is a cross-sectional view of a first modified example of a mold unit that enters a molding operation according to an exemplary embodiment of the present invention. 
         FIG. 9  is a cross-sectional view of a first modified example of a mold unit in which glass molding is completed according to an exemplary embodiment of the present invention. 
         FIG. 10  is a diagram illustrating a change in temperature of a mold unit during passing through a first processing apparatus according to an exemplary embodiment of the present invention. 
         FIG. 11  is a block diagram for explanation of a method for molding curved glass according to an exemplary embodiment of the present invention. 
     
    
    
     MODE FOR INVENTION 
     Hereinafter, an apparatus for molding curved glass will be described with regard to exemplary embodiments of the invention with reference to the attached drawings. However, the present invention may be implemented in various different forms and is not limited to these embodiments. 
     Hereinafter, an apparatus for molding curved glass  1000  according to an exemplary embodiment of the present invention will be described. 
     The apparatus for molding curved glass  1000  may include a first processing apparatus  100  and a second processing apparatus  100   a . The first processing apparatus  100  and the second processing apparatus  100   a  may be arranged to face each other. A plurality of mold units  150  may be moved along a closed loop including the first and second processing apparatuses  100  and  100   a . The first processing apparatus  100  and the second processing apparatus  100   a  may be arranged in parallel. 
     The first processing apparatus  100  may include an inlet part I 1 , a molding part  130 , a mold standby part  101 , a cooling part  140 , a mold unit  150 , moving parts  160  and  170 , an actuator  180 , and an outlet part O 1 . 
     The inlet part I 1  may be used to put the mold unit  150  into the first processing apparatus  100  after putting a plate type glass G on the mold unit  150  by an operator. The mold unit  150  may be moved to a first moving part  160  by a first actuator  181 . 
     The molding part  130  may be used to the mold unit  150  via heat and vacuum adsorptive power of first and second fixing units F 1  and F 2 . The molding part  130  may include a preheating part  110  and a curved surface molding part  120 . The plurality of mold units  150  that are spaced apart from each other between the first and second fixing units F 1  and F 2  may be moved into the molding part  130  by the first moving part  160 . The molding part  130  may be surrounded by a chamber  400  and isolated from atmosphere in the chamber  400  so as to prevent heat from being dissipated out of the chamber  400 . 
     The preheating part  110  may apply heat to the mold unit  150  in room temperature to increase temperature of the mold unit  150  to predetermined temperature. The preheating part  110  may include a first preheating part  111  and a second preheating part  113 . In the present invention, for convenience of description, the two preheating parts  111  and  113  are exemplified. However, one preheating part  110  or three or more preheating parts  110  may be used, needless to say. 
     When the mold unit  150  is moved into the chamber  400  by the first moving part  160 , the first preheating part  111  may pre-heat the mold unit  150  for predetermined time. When the mold unit  150  is moved to the second preheating part  113  by the first moving part  160 , temperature of the mold unit  150  rises due to additional heat. For example, the mold unit  150  may be heated to 300° C. in the first preheating part  111  and heated to 400° C. in the second preheating part  113 . 
     The curved surface molding part  120  may be used to form the glass G to a desired curved surface by simultaneously performing heating, vacuum adsorption, and compression via self load. The curved surface molding part  120  may include first to seventh curved surface molding parts  121 ,  122 ,  123 ,  124 ,  125 ,  126 , and  127 . According to the present invention, for convenience of description, the curved surface molding part  120  is exemplified as seven curved surface molding parts including the first curved surface molding part  121  to the seventh curved surface molding part  127 . However, needless to say, the glass G is formed in one curved surface molding part  120 . 
     The mold unit  150  may be moved by the first moving part  160  via sliding over the first fixing unit F 1  formed on each of the curved surface molding parts  121 ,  122 ,  123 ,  124 ,  125 ,  126 , and  127 . Then, one end  152  of an suction flow path  159  of the mold unit  150  may be positioned to correspond to a suction hole  211  of the first fixing unit F 1 . 
     For example, vacuum adsorptive power is applied to a lower portion of the glass G for 140 seconds. In addition, heat from heating blocks  210  and  310  of first and second temperature control blocks  200  and  300  is applied to upper and lower portions of the glass G for the above time period. In addition, compressive force due to self load of an upper mold  151  is applied to the upper portion of the glass G for the above time period. As the mold unit  150  is moved step by step along each of the curved surface molding parts  121 ,  122 ,  123 ,  124 ,  125 ,  126 , and  127 , adsorptive power and heat may be controlled stepwise according to different adsorptive power and different heat. Accordingly, thermal distortion of the glass G may be prevented and, thus, quality deviation of the curved surface glass G may not occur. In addition, crack may not occur in the glass G and, thus, the curved surface glass G with high quality may be produced. 
     The mold standby part  101  is a portion in which the mold unit  150  discharged from the curved surface molding part  120  is on standby. Shielding doors  453  and  455  for preventing heat or inert gas in the chamber  400  from being externally discharged may be installed before and after the mold standby part  101 . The mold unit  150  in the mold standby part  101  may be moved into the cooling part  140  by the first moving part  160 . 
     The cooling part  140  is a portion in which the curved surface glass G moved into the cooling part  140  is cooled by cooling air to lastly form the curved surface glass G. The glass G moved into the cooling part  140  may be cooled to temperature similar to room temperature. The plurality of cooled mold units  150  may be moved to the outlet part O 1  by a second actuator  183 . In the cooling part  140 , the plurality of mold units  150  may be moved by the second moving part  170 . 
     With reference to  FIGS. 1 and 2 , the mold unit  150  will be described in detail. For convenience of description,  FIG. 1  illustrates an example in which one mold unit  150  is put into the inlet part I 1 . However, a plurality of mold units  150  may be arranged in the first processing apparatus  100  at a predetermined interval. 
     Referring to  FIG. 2 , the mold unit  150  may include upper molds  151  and  153  and lower molds  154  and  155  that are formed of a metallic material. The mold unit  150  is used for thermal molding. The glass G may be put into the mold unit  150  to form a desired curved surface by simultaneously performing vacuum adsorption, heating, and compression. 
     The upper molds  151  and  153  may include a mold cover  151  and a curved surface mold frame  153 . The mold cover  151  may be formed to a predetermined thickness in order to apply compressive force via self load to the glass G. The curved surface mold frame  153  may include two curved portions with predetermined curvature corresponding to a curved surface of the completely molded glass G and one flat portion for providing a flat surface to the glass G. 
     According to the present invention, the mold unit  150  as a multi-cavity mold includes two mold covers  151   a  and  151   b , two curved surface molding frames  153   a  and  153   b , and two molding rooms  155   a  and  155   b . However, needless to say, the mold unit  150  may include three or more multi-cavities formed therein. 
     The lower molds  154  and  155  may include a molding room case  154  and a molding room  155 . 
     The molding room case  154  forms an outer appearance of the lower molds  154  and  155 . The moving part  160  pushes the molding room case  154  of each mold unit  150  at once so as to move the plurality of mold units  150  in the molding part  130 . 
     A plurality of molding rooms  155  may be arranged in the molding room case  154  and the glass G as a molding target may be positioned in each of the molding rooms  155   a  and  155   b . Each of the molding rooms  155   a  and  155   b  may include two curved portions with predetermined curvature corresponding to a shape of each of the molding frames  153   a  and  153   b  and one flat portion for providing a flat surface to the glass G. That is, the molding rooms  155   a  and  155   b  may each have an upper surface with the same shape as the glass G as a molding target and may have engaged shapes. 
     In operation in which the glass G reaches a softening point and a curved surface is formed with a predetermined curvature to complete molding, the molding frames  153   a  and  153   b  may be accommodated in the molding rooms  155   a  and  155   b , respectively. To this end, widths of the molding frames  153   a  and  153   b  may be smaller than widths of the molding rooms  155   a  and  155   b  by as much as twice the thickness of the glass G. 
     The moving parts  160  and  170  may move the plurality of mold units  150  in the first processing apparatus  100 . The moving parts  160  and  170  may include the first moving part  160  and the second moving part  170 . 
     The first moving part  160  may move the plurality of mold units  150  in the molding part  130 . The first moving part  160  may move the plurality of mold units  150  at once according to forward or backward movement of a one-axis robot (not shown) and normal or reverse rotation of a rotator cylinder (not shown). According to the present invention, the case in which the plurality of mold units  150  are moved by a one-axis robot (not shown) and a rotator cylinder (not shown) is exemplified. However, needless to say, the plurality of mold units  150  may be moved by a chain conveyer. 
     The second moving part  170  may move the plurality of mold units  150  in the cooling part  140 . The second moving part  170  may move the plurality of mold units  150  up to the second actuator  183  step by step. 
     The actuator  180  may straightly move the mold unit  150 . The actuator  180  may include the first actuator  181  for pushing the mold unit  150  put into the inlet part I 1  to the molding part  130  and the second actuator  183  for pushing the mold unit  150  to the outlet part O 1  from an end portion of the cooling part  140 . 
     The second processing apparatus  100   a  may have the same components as those of the first processing apparatus  100  and the same component is denoted by corresponding reference numerals. Accordingly, a detailed description of the same component will be omitted here. 
     The second processing apparatus  100   a  may be disposed to face the first processing apparatus  100 . The plurality of mold units  150  may circulate along a closed loop including the first and second processing apparatuses  100  and  100   a . According to the present invention, the case in which the first processing apparatus  100  and the second processing apparatus  100   a  are arranged in parallel is exemplified. However, needless to say, the closed loop including the first and second processing apparatuses  100  and  100   a  is formed in an oval form. 
     The apparatus for molding curved glass  1000  according to the present invention is configured to form a closed loop including the first processing apparatus  100  and the second processing apparatus  100   a  that is the same as the first processing apparatus  100 , in which injection, pre-heating, molding, and discharging are performed (refer to  FIG. 1 ). Accordingly, according to the present invention, mold physical distribution may be minimized to minimize an installation area compared with a prior art containing connected physical distribution. 
     With reference to  FIGS. 3A, 3B, and 4 , the first and second fixing units F 1  and F 2  and the chamber  400  will be described in detail. 
     The first fixing unit F 1  and the second fixing unit F 2  may be arranged to the seventh curved surface molding part  127  from the first preheating part  111  and may each include the plurality of temperature control blocks  200  and  300 . The plurality of mold units  150  may be spaced apart from each other at a predetermined interval and may be moved between the first fixing unit F 1  and the second fixing unit F 2 . The mold unit  150  may be used to perform a molding operation of the glass G while staying on the heating block  210  for a predetermined time period. 
     The pair of temperature control blocks  200  and  300  may be formed on each of the first and second preheating parts  111  and  123  and each of the curved surface molding parts  121 ,  122 ,  123 ,  124 ,  125 ,  126 , and  127 . Accordingly, the mold unit  150  may be heated with increased temperature while passing through each of the temperature control blocks  200  and  300 . 
     The first temperature control block  200  may include the heating block  210 , heat sinks  220 , a plate  230 , a cooling block  240 , and a suction passage  250 . The first temperature control block  200  is rectangular parallelepiped overall. 
     Referring to  FIG. 3B , the heating block  210  may heat the plurality of mold units  150 . The heating block  210  may include the heating block suction hole  211 , a heater accommodation part  213 , a heater  215 , a thermal couple accommodation part  217 , and a thermal couple  219 . 
     The heating block suction hole  211  may be formed in an upper portion of the heating block  210 . The heating block suction hole  211  may constitute an end portion of the suction passage  250  connected to a vacuum suction device (not shown) and may be formed to correspond to a inlet hole  152  of the lower mold  154 . 
     The heater accommodation part  213  may accommodate the heater  215  therein. A plurality of heater accommodation parts  213  may be formed through the heating block  210  at a lateral surface of the heating block  210 . 
     The heater  215  may include a heater  215   a  and a heater cable  215   b  surrounded by the heater  215   a  and supply heat to the heating block  210 . 
     The thermal couple accommodation part  217  may accommodate a thermal couple  219 . A plurality of thermal couple accommodation parts  217  may be formed through the heating block  210  at a lateral surface of the heating block  210 . 
     The thermal couple  219  may detect temperature at a measurement point and may be inserted into the thermal couple accommodation part  217 . 
     The heat sinks  220  may be stacked between the heating block  210  and the cooling block  240  in order to control temperature of the first temperature control block  200 . The heat sinks  220  may each include a heat sink suction hole  221 , protrusions  223 , and hollow portions  225 . 
     The heat sinks  220  may be arranged below the heating blocks  210  according to one-to-one correspondence. As illustrated in  FIG. 4 , the heat sinks  220  may include nine heat sinks  220   a  to  220   i  from the first preheating part  111  that is one end of the molding part  130  to the seventh curved surface molding part  127  that is the other end of the molding part  130 . According to the present invention, heat sinks denoted by  220   a  to  220   f  may be formed with the hollow portions  225  with the same size. The remaining heat sinks  220   g ,  220   h , and  220   i  may be configured with the hollow portions  225  with different sizes. However, for example, needless to say, all of the heat sinks  220   a  to  220   i  may be formed with the hollow portions  225  with different sizes. 
     A contact area of the heat sink  220  with the heating block  210  and the plate  230  is gradually increased as the heat sink  220  approaches the seventh curved surface molding part  127 . According to this configuration, more heat of the heating block  210  may be lost by the cooling block  240  toward the seventh curved surface molding part  127 . Accordingly, temperature of the mold unit  150  in the curved surface molding part  120  may be controlled to an optimal condition for molding the glass G. 
     The heat sink suction hole  221  may be disposed at a vertical lower portion of the heating block suction hole  211 . The heat sink suction hole  221  may form a portion of the suction passage  250  connected to a vacuum suction device (not shown). 
     The protrusions  223  may be formed on upper portion and lower portion of the heat sink  220  to contact the heating block  210  and the plate  230 . The protrusions  223  may be configured in periodically repeated straight forms. 
     The hollow portions  225  may be configured to control a contact area of the heat sink  220  with the heating block  210  and the plate  230 . According to the present invention, although four hollow portions  225  are used, the hollow portions  225  may be polygonal. The heat sink  220  may include one hollow portion or include the plurality of hollow portions  225 . 
     According to shapes of the protrusions  223  and shapes of the hollow portions  225 , a contact area of the heat sink  220  with the heating block  210  and the plate  230  may be determined. 
     The plate  230  may be stacked between the heat sink  220  and the cooling block  240 . The plate  230  may transfer chilly air of the cooling block  240  to the heat sink  220 . The plate  230  may be coupled to and fix the first fixing unit F 1 . To this end, the plate  230  may be configured with a plurality of coupling holes  235  and screws  233 . A plate suction hole  231  may be disposed at a vertical lower portion of the heat sink suction hole  221  and may form a portion of the suction passage  250  connected to a vacuum suction device (not shown). 
     The cooling block  240  may be a cooling device for adjusting temperature of the first temperature control block  200 . The cooling block  240  may be staked on the plate  230 . The cooling block  240  may include a cooling block suction hole  241 , a plurality of coupling holes  245 , and a flow path  247 . 
     The cooling block suction hole  241  may be disposed at a vertical lower portion of the plate suction hole  231  and may form a portion of the suction passage  250  connected to a vacuum suction device (not shown). 
     The plurality of coupling holes  245  may be coupled to the screws  233  of the plate  230 . 
     The flow path  247  is a portion through which cold water passes. The cooling block  240  may lower temperature of the mold unit  150  according to cold water passing through the flow path  247 . 
     The suction passage  250  is a path for connecting the heating block suction hole  211 , the heat sink suction hole  221 , the plate suction hole  231 , and the cooling block suction hole  241 . The suction passage  250  may be connected to a vacuum suction device (not shown) to add vacuum adsorptive power to the plurality of mold units  150 . 
     The plurality of second temperature control blocks  300  of the second fixing unit F 2  may have almost the same components as the plurality of first temperature control blocks  200  of the first fixing unit F 1 . However, the second fixing unit F 2  does not disclose the same component such as the suction passage  250  of the first fixing unit F 1 . Accordingly, for convenience of description, the same component as the first fixing unit F 1  will be omitted. 
     The second temperature control block  300  may include a heating block  310 , a heat sink  320 , a plate  330 , and a cooling block  340 . Based on the mold unit  150 , components of the second temperature control block  300  of the second fixing unit F 2  may be stacked to correspond to respective components of the first temperature control block  200  of the first fixing unit F 1 . 
     Referring to  FIGS. 3A and 4 , the chamber  400  may be disposed to surround the plurality of mold units  150  and the first and second fixing units F 1  and F 2  of the molding part  130 . 
     Inert gas may be supplied into the chamber  400  to prevent the first and second fixing units F 1  and F 2  and the mold unit  150  from being oxidized. Although not illustrated, inert gas may be discharged by an exhaust pipe. 
     When the mold unit  150  is put into or out of the chamber  400 , a plurality of barriers  420 ,  430 , and  440  may be formed at opposite ends of the molding part  130  and an inlet part of the mold standby part  101  in order to prevent inert gas and heat from leaking. Opening and closing doors  450  may be formed at each barrier. Each of opening and closing doors  451 ,  453 , and  455  may be formed up and down direction so as to be opened for a predetermined time period only during movement of the mold unit  150 . 
     The plurality of mold units  150  may be moved into the chamber  400 . In addition, a core chamber  410  in which heating and molding are performed may be located in the chamber  400 . The core chamber  410  may be configured with a frame. 
     In order to support the second fixing unit F 2  in the chamber  400 , an upper portion of the chamber  400  and the second fixing unit F 2  may be supported by a plurality of support brackets  420 . 
     With reference to  FIGS. 5 and 6 , a molding procedure in the plurality of mold units  150  will be described. 
       FIG. 5  illustrates a procedure of heating the mold unit  150  in the preheating part  110  or a portion of the curved surface molding part  120  prior to molding. The glass G may be put in each of the molding rooms  155   a  and  155   b  of the plurality of mold units  150  disposed between the first and second fixing units F 1  and F 2 . The upper molds  151  and  153  may be put on the glass G. The upper molds  151  and  153  may be integrally formed. 
     In the preheating part  110 , vacuum suction through the suction passage  250  may not be applied to the mold unit  150 . However, suction force of a vacuum suction device (not shown) through the suction passage  250  may be applied to a lower portion of the mold unit  150  while entering the curved surface molding part  120 . Suction forces at the curved surface molding parts  121 ,  122 ,  123 ,  124 ,  125 ,  126 , and  127  may be differently controlled. 
     The first inlet hole  152  corresponding to the suction hole  211  at an upper portion of the heating block  210  may be formed in a lower portion of the molding room case  154 . Suction flow paths  159   a  and  159   b  connected to second and third inlet holes  157   a  and  157   b  at lower portions of the molding rooms  155   a  and  155   b  from the inlet hole  152  may be formed. Accordingly, suction force at a vacuum suction device (not shown) may be transferred to the suction passage  250 , the suction flow path  159 , and the second and third inlet holes  157   a  and  157   b  and the glass G may be adsorbed to a lower portion from an upper portion of each of the molding rooms  155   a  and  155   b  according to the suction force. 
       FIG. 6  illustrates a state in which molding of the glass G is completed in the mold unit  150 . Towards the seventh curved surface molding part  127  from the first molding part  121 , vacuum adsorptive power and temperature may be controlled step by step as increased to a preset value. In addition, when the glass G reaches a softening point, the glass G may be molded with two curved portions with predetermined curvature and one flat portion so as to correspond to upper shapes of each of the molding frames  153   a  and  153   b  and each of the molding rooms  155   a  and  155   b  according to compressive force due to self load of the upper molds  151  and  153 . In this case, vacuum adsorption, heating, and compressive force may be simultaneously applied. 
       FIGS. 7 to 9  illustrate a mold unit and an upper heater unit according to a first modified example of an exemplary embodiment of the present invention. 
     Referring to  FIG. 7 , the mold unit and the upper heat unit according to the first modified example of an exemplary embodiment of the present invention are almost the same as the examples of the mold unit and the second temperature control block according to an exemplary embodiment of the present invention and are different from the examples of the mold unit and the second temperature control block according to an exemplary embodiment of the present invention in that an upper mold of a mold unit and an upper heater unit are separately formed. The mold unit and the upper heat unit according to the first modified example of an exemplary embodiment of the present invention are denoted by the same reference numerals as the mold unit and the second temperature control block according to an exemplary embodiment of the present invention. The first modified example will be described in terms of a difference from the example. 
     Referring to  FIG. 7 , a mold unit  650  is used for thermal molding and may include upper molds  651   a ,  651   b ,  653   a , and  653   b  and lower molds  654   a ,  654   b ,  655   a , and  655   b  which are formed of a metallic material. 
     Components of the lower molds  654   a ,  654   b ,  655   a , and  655   b  of the mold unit  650  according to the first embodied example of an exemplary embodiment of the present invention are the same as components of the lower molds  154  and  155  that are integrally formed according to an exemplary embodiment of the present invention. 
     However, differently from the upper molds  151  and  153  of the mold unit  150  according to an exemplary embodiment of the present invention, the upper molds  651   a ,  651   b ,  653   a , and  653   b  of the mold unit  650  according to the first modified example of an exemplary embodiment of the present invention may be configured in such a way that the upper molds  651   a ,  651   b ,  653   a , and  653   b  may be separately formed at each cavity of the lower molds  654   a ,  654   b ,  655   a , and  655   b , that is, each of the molding rooms  655   a  and  655   b.    
     In more detail, one of the upper molds  651   a ,  651   b ,  653   a , and  653   b  may be formed above of each of the molding rooms  655   a  and  655   b . That is, first upper molds  651   a  and  653   a  may be formed on first lower molds  654   a  and  655   a , second upper molds  651   b  and  653   b  may be formed on second lower molds  654   b  and  655   b , and the first upper molds  651   a  and  653   a  and the second upper molds  651   b  and  653   b  may be spaced apart from each other by a predetermined interval. 
     Components of upper heater units  700   a  and  700   b  according to the first modified example of an exemplary embodiment of the present invention are almost the same as those of the second temperature control block  300  according to an exemplary embodiment of the present invention but are different from the second temperature control block  300  according to an exemplary embodiment of the present invention in that the upper heater units  700   a  and  700   b  are formed as the first upper heater unit  700   a  and the second upper heater unit  700   b  that are separately formed. 
     The first upper heater unit  700   a  may include a heating block  710   a , a heat sink  720   a , a plate  730   a , and a cooling block  740   a  and the second temperature control block  300  may be configured in the same way as the heating block  310 , the heat sink  320 , the plate  330 , and the cooling block  340 . 
     The second upper heater unit  700   b  may also include a heating block  710   b , a heat sink  720   b , a plate  730   b , and a cooling block  740   b  and the second temperature control block  300  may be configured in the same way as the heating block  310 , the heat sink  320 , the plate  330 , and the cooling block  340 . 
     Differently from the second temperature control block  300  that is configured with one component, the upper heater units  700   a  and  700   b  may be configured with a plurality of components to correspond to the upper molds  651   a ,  651   b ,  653   a , and  653   b , respectively. In more detail, the first upper heater unit  700   a  may be disposed on the first upper molds  651   a  and  653   a  and the second upper heater unit  700   b  may be disposed on the second upper molds  651   b  and  653   b . In addition, the first upper heater unit  700   a  and the second upper heater unit  700   b  may be formed to be spaced apart from each other by a preset interval. 
     The upper molds  651   a ,  651   b ,  653   a , and  653   b  and the upper heater units  700   a  and  700   b  according to the first modified example of an exemplary embodiment of the present invention with the above configuration may enhance productivity compared with a single cavity by applying a multiple cavity to a mold. In addition, the upper heater units  700   a  and  700   b  may be separately applied to each of the upper molds  651   a ,  651   b ,  653   a , and  653   b  and, thus, each upper heater unit may be independently controlled to reduce molding quality deviation for each cavity, that is, each molding room of a lower mold, thereby enhancing molding quality of glass, compared with the case in which an upper mold and an upper heater unit are integrally molded. 
     That is, when the upper mold and the upper heater unit are integrally formed, more heat is applied to a middle portion of a mold unit due to a structure of a heater unit, compared with a lateral portion of the mold unit. According to this configuration, temperature of a middle portion of the upper mold is highest and is lowered toward a lateral end and, thus, quality distribution may occur on glass formed in each mold unit. However, the upper mold and the upper heater unit according to the first modified example of the present invention may be configured in such a way that each separate upper heater unit is installed for each upper mold so as to reduce quality distribution formed in each mold unit. 
       FIG. 8  is a cross-sectional view of a mold unit that enters a molding operation according to a first modified example of exemplary embodiment of the present invention.  FIG. 9  is a cross-sectional view of a mold unit on which molding of glass is completed according to the first modified example of exemplary embodiment of the present invention. 
     Components of the mold unit and the upper heater unit indicating a molding operation according to the first modified example of an exemplary embodiment of the present invention are almost the same as those of the mold unit and the second temperature control block indicating a molding operation according to an exemplary embodiment of the present invention. Accordingly, a detailed description of the same component and operation will be omitted. The mold unit and the upper heat unit according to the first modified example of an exemplary embodiment of the present invention are denoted by the same reference numerals as the mold unit and the second temperature control block according to an exemplary embodiment of the present invention. 
       FIG. 8  illustrates a procedure of heating the mold unit  650  in a portion of a preheating operation or a molding operation. The glass G may be put in each of the molding rooms  655   a  and  655   b  of the plurality of mold units  650 . The upper molds  651   a ,  651   b ,  653   a , and  653   b  may be put on the glass G. 
     In the preheating operation, vacuum suction through a suction passage  550  may not be applied to the mold unit  650 . However, as the mold unit  650  enters a molding operation, suction force of a vacuum suction device (not shown) through a suction passage  550  may be applied to a lower portion of the mold unit  650 . 
     According to suction force of a vacuum suction device (not shown) through the suction passage  550 , the glass G may be adsorbed on each of the molding rooms  655   a  and  655   b.    
       FIG. 9  illustrates a state in which molding of the glass G is completed in the mold unit  650 . During a molding operation, vacuum adsorption, heating, and compressive force may be simultaneously applied to the glass G. 
     When the upper molds  651   a ,  651   b ,  653   a , and  653   b  are integrally formed, mold covers  651   a  and  651   b  may be connected and bending deflection may occur due to self load of each of molding frames  653   a  and  653   b  at the connection portions. Accordingly, predetermined load may not applied to each glass G. The upper molds  651   a ,  651   b ,  653   a , and  653   b  according to an exemplary embodiment of the present invention and the upper heater units  700   a  and  700   b  according to the first modified example are configured in such a way that loads of the upper molds  651   a ,  651   b ,  653   a , and  653   b  is constantly applied to the glass G in each of the molding rooms  655   a  and  655   b  as the upper molds  651   a ,  651   b ,  653   a , and  653   b  are separately formed. Accordingly, molding quality deviation for each cavity may be advantageously reduced. 
       FIG. 10  is a schematic diagram illustrating change in temperature while the mold unit  150  passes through the preheating part  110 , the curved surface molding part  120 , and the cooling part  140 . 
     During a preheating operation at room temperature, temperature begins to increase. During a molding operation, temperature may further increase to show highest temperature distribution in the seventh curved surface molding part  127 . As described above, a shape of the heat sink  220  may be differently configured. Accordingly, temperature gradient of the curved surface molding part  120  may be smoothly controlled to a preset value using temperature of the seventh curved surface molding part  127  as a peak. That is, the molding part  130  may gradually reduce a rate of increase of heat applied to the plurality of mold units  150  toward the cooling part  140  from the inlet part I 1 . 
     Hereinafter, a mobile window method for molding curved glass according to the present invention will be described in detail with reference to  FIG. 11 . 
     As illustrated in  FIG. 11 , the mobile window method for molding curved glass according to an exemplary embodiment of the present invention will be described below. 
     First, the glass G may be put in the mold unit  150  and the mold unit  150  is input to a first process (S 1 ). 
     Then, the glass G may be preheated in the preheating part  110  (S 2 ). Vacuum adsorptive power may not be applied to the mold unit  150  in the preheating part  110 . 
     The glass G may be molded in the curved surface molding part  120  (S 3 ). 
     In a heating operation including the preheating operation and the molding operation, rate of increase of heat applied to the plurality of mold units  150  may be gradually reduced toward an end point of the heating operation from a start point of the heating operation. 
     In the heating operation, the glass G may be molded through vacuum adsorption from the lower molds  154  and  155  of the mold unit  150  and self load compression from the upper molds  151  and  153  of the mold unit  150 . 
     The molded glass G may be cooled in the cooling part  140  (S 4 ). 
     The glass G on which cooling is completed may be extracted from the mold unit  150  (S 5 ). 
     In this case, the mold unit  150  may be moved along a closed loop including a first process including S 1  to S 5  and a second process including the same processes as the first process. In addition, an operator is positioned at the inlet parts I 1  and I 2  and outlet parts O 1  and O 2  between the first process and the second process. The glass G in which molding and cooling are completed may be extracted from the outlet parts O 1  and O 2  and the mold unit  150  from which the glass G is extracted may be cleaned. The glass G may be put in the cleaned mold unit  150  at the inlet parts I 1  and I 2  and the mold unit  150  may be input to the first process and the second process. 
     The foregoing exemplary embodiments and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. Also, the description of the exemplary embodiments of the present invention is intended to be illustrative, and not to limit the scope of the claims, and many alternatives, modifications, and variations will be apparent to those skilled in the art. 
     INDUSTRIAL APPLICABILITY 
     The present invention relates to an apparatus for molding curved glass and a method for molding curved glass using the same.