Patent Publication Number: US-2013249148-A1

Title: Shape adjusting mechanism for extrusion molding machine, and method of manufacturing cylindrical member

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2012-064560 filed Mar. 21, 2012. 
     BACKGROUND 
     Technical Field 
     The present invention relates to a shape adjusting mechanism for an extrusion molding machine, and to a method of manufacturing a cylindrical member. 
     SUMMARY 
     According to an aspect of the invention, there is provided a shape adjusting mechanism for an extrusion molding machine. The shape adjusting mechanism includes a shape adjusting member, a blow-in mechanism, and a discharge mechanism. The shape adjusting member comes into contact with an inner circumferential surface of a molten substantially cylindrical resin extruded and transported from a ferrule provided to an extrusion molding machine, and adjusts the shape of the substantially cylindrical resin. The blow-in mechanism blows a gas into the substantially cylindrical resin transported between the ferrule and the shape adjusting member. The discharge mechanism discharges to the outside the gas in the substantially cylindrical resin transported between the ferrule and the shape adjusting member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments of the present invention will be described in detail based on the following figures, wherein: 
         FIG. 1  is a cross-sectional view illustrating a sizing mechanism according to a first exemplary embodiment of the invention; 
         FIG. 2  is a perspective view illustrating a sizing die used in the sizing mechanism according to the first exemplary embodiment of the invention; 
         FIG. 3  is a schematic configuration diagram illustrating an extrusion molding machine including the sizing mechanism according to the first exemplary embodiment of the invention; 
         FIG. 4  is a diagram illustrating evaluation results evaluating cylindrical members molded by the use of the sizing mechanism according to the first exemplary embodiment of the invention; 
         FIG. 5  is a cross-sectional view illustrating a sizing mechanism according to a second exemplary embodiment of the invention; 
         FIGS. 6A and 6B  are perspective views illustrating a sizing die used in a sizing mechanism according to a third exemplary embodiment of the invention; 
         FIG. 7  is a cross-sectional view illustrating a sizing die used in a sizing mechanism according to a fourth exemplary embodiment of the invention; 
         FIGS. 8A ,  8 B, and  8 C are cross-sectional views illustrating the sizing die used in the sizing mechanism according to the fourth exemplary embodiment of the invention; 
         FIG. 9  is a perspective view illustrating a sizing mechanism according to a fifth exemplary embodiment of the invention; 
         FIG. 10  is a cross-sectional view illustrating the sizing mechanism according to the fifth exemplary embodiment of the invention; and 
         FIGS. 11A ,  11 B, and  11 C are plan views illustrating the movement of shutter members and so forth used in the sizing mechanism according to the fifth exemplary embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     In accordance with  FIGS. 1 to 4 , description will be made of an example of a shape adjusting mechanism for an extrusion molding machine and a method of manufacturing a cylindrical member according to a first exemplary embodiment of the present invention. An arrow UP illustrated in the drawings indicates an upward vertical direction. 
     Overall Configuration:  FIG. 3  illustrates an extrusion molding machine  12  including a sizing mechanism  10  as an example of a shape adjusting mechanism for an extrusion molding machine according to the present exemplary embodiment. As illustrated in  FIG. 3 , the extrusion molding machine  12  includes, as major mechanisms, a hopper  16 , an extruder  18 , a ferrule  20 , the sizing mechanism  10 , a transport mechanism  22 , and a cutting mechanism  24 . A pelletized resin material P is put into the hopper  16 . The extruder  18  transports the resin material P put into the hopper  16 , while melting and stirring the resin material P. The ferrule  20  extrudes the resin material P molten and stirred by the extruder  18  into a cylindrical resin T. The sizing mechanism  10  stabilizes (adjusts) the shape of the molten cylindrical resin T extruded from the ferrule  20 , as compared with a case where a later-described air pump  42  is not provided. The transport mechanism  22  applies transporting force to the cylindrical resin T to transport the cylindrical resin T from the ferrule  20  toward the sizing mechanism  10 . The cutting mechanism  24  cuts the cylindrical resin T stabilized in shape by the sizing mechanism  10  into a determined length, and thereby forms a cylindrical member S. 
     Hopper: As illustrated in  FIG. 3 , the hopper  16  includes a conical portion  16 A increased in diameter toward the upper side and a cylindrical portion  16 B connected to the upper end of the conical portion  16 A. The cylindrical portion  16 B has an upper portion which is exposed to the outside, and into which the pelletized resin material P is put. 
     Extruder: The extruder  18  includes a cylindrical barrel  26  which extends in a horizontal direction, a screw  28  which is provided inside the barrel  26  and rotates to transport the resin material P put into the hopper  16  while stirring the resin material P, and a not-illustrated heating device which heats the barrel  26 . 
     Specifically, a base end portion of the hopper  16  is connected to one end portion of the barrel  26  such that the pelletized resin material P put into the hopper  16  is transported into the barrel  26 . Further, the screw  28  is disposed inside the barrel  26  to extend from the one end portion of the barrel  26  toward the other end portion of the barrel  26 . The screw  28  rotates to cause the resin material P transported into the barrel  26  to be transported from the one end portion of the barrel  26  toward the other end portion of the barrel  26 , while stirring the resin material P. 
     With this configuration, the resin material P transported into the barrel  26  heated by the heating device is molten, and is transported from the one end portion of the barrel  26  toward the other end portion of the barrel  26  by the rotating screw  28 , while being stirred by the screw  28 . 
     Ferrule: The ferrule  20  for molding the resin material P into the cylindrical resin T is connected to the other end portion of the barrel  26 . A ferrule body  32  of the ferrule  20  is formed with a resin flow channel  34 , into which the molten resin material P extruded from the other end portion of the barrel  26  by the rotating screw  28  flows. 
     Further, a downstream end of the resin flow channel  34  in a flow direction of the resin material P is provided with an extrusion port  36  for extruding the resin material P to the outside from the ferrule body  32 . The extrusion port  36  is formed into a ring shape such that the resin material P extruded from the extrusion port  36  is formed into the molten cylindrical resin T. 
     Sizing Mechanism: The sizing mechanism  10  for stabilizing the shape of the molten cylindrical resin T extruded from the ferrule  20  includes a sizing die  40  (an example of a shape adjusting member), an air pump  42 , and through-holes  60 . The sizing die  40  comes into contact with an inner circumferential surface of the molten cylindrical resin T extruded from the extrusion port  36 . The air pump  42  is an example of a blow-in mechanism which blows air (an example of a gas) into the cylindrical resin T transported between the ferrule  20  and the sizing die  40 . The through-holes  60  configure a ventilation mechanism  59  which discharges to the outside the air in the cylindrical resin T transported between the ferrule  20  and the sizing die  40 . The sizing mechanism  10  will be described in detail later. 
     Transport Mechanism: The transport mechanism  22  for applying the transporting force to the cylindrical resin T to transport the cylindrical resin T from the ferrule  20  toward the sizing mechanism  10  is disposed on the opposite side of the ferrule  20  across the sizing die  40 . The transport mechanism  22  includes plural (two in the exemplary embodiment) rollers  50  and belt devices  52 . The rollers  50  are provided inside the cylindrical resin T, and come into contact with the inner circumferential surface of the cylindrical resin T. Each of the belt devices  52  is provided on the opposite side of the corresponding roller  50  across a cylinder wall of the cylindrical resin T, and comes into contact with an outer circumferential surface of the cylindrical resin T. 
     Each of the belt devices  52  includes a pair of rollers  52 A aligned in a transport direction of the cylindrical resin T and an endless belt  52 B wound around the pair of rollers  52 A. Each of the belt devices  52  further includes a not-illustrated motor which applies to the rollers  50  and  52 A rotational force acting in the directions of arrows in the drawing. In accordance with the rotation of the rollers  52 A, the endless belt  52 B circularly moves in the direction of an arrow in the drawing. 
     With this configuration, the cylindrical resin T sandwiched by the rotating rollers  50  and the circularly moving endless belts  52 B is applied with the transporting force. 
     Cutting Mechanism: On the downstream side of the transport mechanism  22  in the transport direction of the cylindrical resin T, the cutting mechanism  24  is provided which cuts the cylindrical resin T stabilized in shape by the sizing mechanism  10  into the determined length. 
     Specifically, the cutting mechanism  24  is provided with a cutter  24 A which cuts the cylindrical resin T. The cutter  24 A is operated with determined timing. Thereby, the cylindrical resin T is cut into the determined length to be formed into the cylindrical member S. 
     Configuration of Major Components: Subsequently, the sizing mechanism  10  will be described. 
     As illustrated in  FIGS. 1 and 2 , a cylindrical support member  56  extending in a vertical direction has a lower end portion fixed to an upper surface  40 B of the sizing die  40 , and the sizing die  40  is supported by the support member  56 . The support member  56  extending in the vertical direction passes through the ferrule body  32 , and an upper end portion of the support member  56  is exposed to the outside from the ferrule body  32  (see  FIG. 3 ). A portion of the support member  56  passing through the ferrule body  32  is fixed to the ferrule body  32 . Further, the support member  56  is formed with a communication hole  58  which extends in the vertical direction and allows the outside of the support member  56  passing through the ferrule body  32  and the interior of the cylindrical resin T transported between the ferrule  20  and the sizing die  40  to communicate with each other. 
     As illustrated in  FIG. 3 , the air pump  42  for blowing air into the cylindrical resin T transported between the ferrule  20  and the sizing die  40  is connected to an upper end portion of the communication hole  58 . 
     As illustrated in  FIGS. 1 and 2 , the sizing die  40  fixed to the lower end portion of the support member  56  extends in the transport direction of the cylindrical resin T (vertical direction in the exemplary embodiment), and is formed into a cylindrical shape larger in diameter than the support member  56 . The inner circumferential surface of the cylindrical resin T extruded from the extrusion port  36  (see  FIG. 3 ) comes into contact with an outer circumferential surface  40 A of the cylindrically shaped sizing die  40 . 
     Specifically, the air pump  42  blows air into the cylindrical resin T transported between the ferrule  20  and the sizing die  40 . Thereby, the pressure in the cylindrical resin T is increased to be higher than the atmospheric pressure, and the cylindrical resin T expands outward in a bent manner. With the cylindrical resin T expanding outward, the inner circumferential surface of the cylindrical resin T comes into contact with the outer circumferential surface  40 A of the sizing die  40  without touching a corner portion  40 C of the sizing die  40 . 
     Further, the through-holes  60 , which discharge the air in the cylindrical resin T transported between the ferrule  20  and the sizing die  40  to the outside exposed to the atmosphere, are provided to pass through the sizing die  40  in the transport direction of the cylindrical resin T. Accordingly, the air in the cylindrical resin T transported between the ferrule  20  and the sizing die  40  is discharged to the outside through the through-holes  60 . Therefore, the leakage of air to the outside from between the sizing die  40  and the cylindrical resin T is suppressed. 
     Further, plural fans  62  are provided which blow wind to the cylindrical resin T in contact with the outer circumferential surface  40 A of the sizing die  40 , to thereby cool the cylindrical resin T. 
     Operations: Subsequently, operations of the extrusion molding machine  12  and the sizing mechanism  10  will be described with explanation of a method of manufacturing the cylindrical member S. 
     Method of Manufacturing Cylindrical Member: As illustrated in  FIG. 3 , in the extrusion molding machine  12 , the pelletized resin material P put into the hopper  16  is transported into the barrel  26  provided to the extruder  18 . The resin material P transported into the barrel  26  heated by the heating device is molten, and is transported from the one end portion of the barrel  26  toward the other end portion of the barrel  26  by the rotating screw  28 , while being stirred by the screw  28  (stirring and transporting process). 
     The resin material P extruded from the other end portion of the barrel  26  by the rotating screw  28  flows into the resin flow channel  34  formed in the ferrule body  32 , and is further extruded into the cylindrical resin T from the extrusion port  36  (extrusion process). 
     The inner circumferential surface of the molten cylindrical resin T extruded from the ferrule  20  comes into contact with the outer circumferential surface  40 A (see  FIG. 1 ) of the sizing die  40  provided to the sizing mechanism  10 . Further, the fans  62  blow wind to the cylindrical resin T in contact with the outer circumferential surface  40 A of the sizing die  40 , and thereby cool the cylindrical resin T. Thereby, the shape of the cylindrical resin T is stabilized (stabilization process). 
     Further, the cutter  24 A provided to the cutting mechanism  24  cuts the cylindrical resin T stabilized in shape in the stabilization process into the determined length, and thereby forms the cylindrical member S (cutting process). 
     Herein, in the stabilization process, the air pump  42  blows air into the cylindrical resin T transported between the ferrule  20  and the sizing die  40 . Thereby, the pressure in the cylindrical resin T is increased to be higher than the atmospheric pressure, and the cylindrical resin T expands outward in a bent manner. Thereby, the inner circumferential surface of the cylindrical resin T comes into contact with the outer circumferential surface  40 A of the sizing die  40  without touching the corner portion  40 C of the sizing die  40  (see  FIG. 1 ). 
     Further, the air in the cylindrical resin T transported between the ferrule  20  and the sizing die  40  is discharged to the outside through the through-holes  60  provided in the sizing die  40 . Therefore, the discharge (leakage) of air to the outside from between the sizing die  40  and the cylindrical resin T is suppressed. 
     Further, the through-holes  60  are provided in the sizing die  40 , which configures an internal space of the cylindrical resin T transported between the ferrule  20  and the sizing die  40 . Accordingly, the air in the cylindrical resin T is discharged to the outside with a simple configuration, as compared with a case where the sizing die  40  is not provided with a through-hole. 
     With this configuration, cockling of the cylindrical resin T (cylindrical member S) caused by the discharge of air to the outside from between the sizing die  40  and the cylindrical resin T is suppressed. 
     Evaluations: Herein, cylindrical members S molded by the use of the sizing mechanism  10  according to the exemplary embodiment and a cylindrical member S molded by the use of a sizing mechanism according to a comparative example are evaluated in terms of the cockling (undulation) and so forth. 
     The pelletized resin material P used in the evaluations is obtained by the following method. 
     Resin Material: A semi-aromatic polyamide resin (N1000C-H32 manufactured by Kuraray Co., Ltd., which is a condensate of terephthalic acid as an aromatic dicarboxylic acid compound and 1,9-nonanediamine/2-methyl-1,8-octanediamine as an aliphatic diamine compound, wherein an aromatic ring of the aromatic dicarboxylic acid compound is a benzene ring, and the number of carbons in the alkyl group of the aliphatic diamine compound is 9) is mixed with 22 phr of a carbon black (Monarch M880 manufactured by Cabot Specialty Chemicals, Inc. and having a primary particle diameter of 15 nm). With the use of a twin-screw melt mixer (manufactured by Parker Corporation), the resin and the carbon black are melt-mixed with rotational torque of the screws set to 121 Nm, and with a barrel heating temperature set in phases to be 270° C. at the most downstream position (on the material supply side) of the barrel and be gradually increased therefrom to a maximum heating temperature of 300° C. Further, a molten strand (a rope shape having a diameter of approximately 2 mm) of the mixture discharged from a discharge port of the mixer is passed through a water tank to be cooled. Then, the cooled and solidified strand is inserted into a pelletizer and cut. Thereby, a pelletized resin material P (mixed resin pellets) having a length of approximately 5 mm is obtained. A unit “phr” represents the mass of the material relative to the mass of the resin represented as  100 . 
     First Example: The above-described pelletized resin material P is put into the hopper  16 . With the temperature of the barrel  26  set to 280° C., and with the temperature of the ferrule body  32 , which has a diameter of 170 mm for extruding the resin (size G illustrated in  FIG. 1 ), set to 300° C., the resin material P is extruded into the cylindrical resin T from the ferrule body  32 , while the cylindrical resin T is being applied with the transporting force by the transport mechanism  22 . 
     The inner circumferential surface of the extruded cylindrical resin T is brought into contact with the outer circumferential surface  40 A of the sizing die  40  formed with the through-holes  60  and having a diameter of 160 mm (size H illustrated in  FIG. 1 ), and thereby the cylindrical resin T is cooled. The cooled cylindrical resin T is cut with the use of the cutting mechanism  24 , and thereby a cylindrical member S (endless belt) having a diameter of 159.7 mm and a width (height) of 232 mm is obtained. 
     The sizing die  40  is formed with four through-holes  60  each having a diameter of 0.7 mm. 
     Second Example: Compared with the first example, the diameter of the ferrule body  32  for extruding therefrom the resin (size G illustrated in  FIG. 1 ) is set to 140 mm. In the other aspects, the second example is configured similarly to the first example. Thereby, a cylindrical member S (endless belt) having a diameter of 159.5 mm and a width (height) of 232 mm is obtained. 
     Comparative Example: Compared with the first example, a sizing die not formed with a through-hole is used. In the other aspects, the comparative example is configured similarly to the first example. Thereby, a cylindrical member S (endless belt) having a diameter of 159.6 mm and a width (height) of 232 mm is obtained. 
     Evaluation Items: As to cockling (undulation) evaluation, the measurement of surface cockling (undulation) is performed on the respective cylindrical members S (endless belts) obtained in the first example, the second example, and the comparative example with the use of a surface roughness measuring apparatus SURFCOM 1400D (manufactured by Tokyo Seimitsu Co., Ltd.). The evaluation criterion is set such that cockling of 3.0 μm or less is at an acceptable quality level. As to image evaluation, each of the cylindrical members S (endless belts) obtained in the first example, the second example, and the comparative example is used as a transfer belt of an image forming apparatus (DPC105 manufactured by Fuji Xerox Co., Ltd.). Then, an image obtained after operating the image forming apparatus and outputting fifty halftone (magenta 30%) images is evaluated. An image not having an image failure, such as the appearance of a streak, is evaluated as favorable, and any other image is evaluated as unfavorable. 
     Evaluation Results:  FIG. 4  illustrates the results of the cockling (undulation) evaluation and the image evaluation summarized in a table. As illustrated in  FIG. 4 , in the first and second examples, a favorable result is obtained in both the cockling (undulation) evaluation and the image evaluation. Meanwhile, in the comparative example, a satisfactory result fails to be obtained in both the cockling (undulation) evaluation and the image evaluation. Particularly as to the image evaluation, the cockling of the cylindrical member S causes a cleaning failure to clean the cylindrical member S and a transfer failure to transfer a toner image formed on the cylindrical member S to an object to which the toner image is to be transferred. As a result, the image failure is caused. 
     As understood from the above-described results, the air in the cylindrical resin T transported between the ferrule  20  and the sizing die  40  is discharged through the through-holes  60  provided in the sizing die  40 , and thereby the cockling occurring in the cylindrical member S molded by extrusion molding is suppressed. 
     Second Exemplary Embodiment: Subsequently, an example of a sizing mechanism  64  according to a second exemplary embodiment of the invention will be described in accordance with  FIG. 5 . The same members as those of the first exemplary embodiment will be designated by the same reference numerals, and description thereof will be omitted. 
     As illustrated in  FIG. 5 , the sizing die  40  is not provided with a through-hole for discharging to the outside the air in the cylindrical resin T transported between the ferrule  20  and the sizing die  40 . In the second exemplary embodiment, such a through-hole is replaced by a through-hole  66  formed in the support member  56  as an example of a discharge mechanism which discharges to the outside the air in the cylindrical resin T transported between the ferrule  20  and the sizing die  40 . 
     Accordingly, the air in the cylindrical resin T transported between the ferrule  20  and the sizing die  40  is discharged to the outside through the through-hole  66  formed in the support member  56 . The second exemplary embodiment is similar to the first exemplary embodiment in the other operations. 
     Third Exemplary Embodiment: Subsequently, an example of a sizing mechanism  68  according to a third exemplary embodiment of the invention will be described in accordance with  FIGS. 6A and 6B . The same members as those of the first exemplary embodiment will be designated by the same reference numerals, and description thereof will be omitted. 
     As illustrated in  FIGS. 6A and 6B , a sizing die  70  of the sizing mechanism  68  according to the third exemplary embodiment is formed with two through-holes  72 . Further, small-diameter members  74  are provided to be attachable to and detachable from the respective through-holes  72 . Each of the small-diameter members  74  is an example of a changing unit that changes the flow rate of the air passing through the corresponding through-hole  72 . 
     Specifically, the small-diameter member  74  is formed into a cylindrical shape capable of being housed in the through-hole  72 , and an outer circumferential surface of the small-diameter member  74  is attached with an  0 -ring  76  which suppresses the leakage of air between the outer circumferential surface of the small-diameter member  74  and the inner circumferential surface of the through-hole  72 . Further, the small-diameter member  74  is formed with a through-hole  74 A which is smaller in diameter than the through-hole  72 , and which discharges to the outside the air in the cylindrical resin T transported between the ferrule  20  and the sizing die  70 . Accordingly, a ventilation mechanism  71 , which discharges the air in the cylindrical resin T to the outside, includes the through-holes  72  and the small-diameter members  74 . 
     Accordingly, if it is desired to change the flow rate of the air passing through the through-holes  72 , the small-diameter members  74  may be attached to the through-holes  72 , or the small-diameter members  74  may be detached from the through-holes  72  attached with the small-diameter members  74 , to thereby change the flow rate of the air passing through the through-holes  72 . 
     Further, the through-holes  74 A formed in the respective small-diameter members  74  may be changed in diameter, to thereby change the flow rate of the air passing through the through-holes  72 . The third exemplary embodiment is similar to the first exemplary embodiment in the other operations. 
     Fourth Exemplary Embodiment: Subsequently, an example of a sizing mechanism  78  according to a fourth exemplary embodiment of the invention will be described in accordance with  FIGS. 7 to 8C . The same members as those of the first exemplary embodiment will be designated by the same reference numerals, and description thereof will be omitted. 
     As illustrated in  FIG. 7 , a sizing die  80  of the sizing mechanism  78  according to the fourth exemplary embodiment is formed with two through-holes  82 , and is provided with changing devices  84 , each of which is an example of a changing unit that changes the flow rate of the air passing through the corresponding through-hole  82 . 
     Specifically, each of the through-holes  82  includes an upper communication path  82 A opening in an upper surface  80 A of the sizing die  80 , two lower communication paths  82 B opening in a lower surface  80 B of the sizing die  80 , and a communication chamber  82 C which allows the upper communication path  82 A and the lower communication paths  82 B to communicate with each other. 
     Each of the changing devices  84  is disposed in the corresponding communication chamber  82 C. The changing device  84  includes an opening and closing valve  84 A and a spring member  84 B. The opening and closing valve  84 A is movably provided to change the flow rate of the air passing between the upper communication path  82 A and the communication chamber  82 C (to change flow channel resistance). The spring member  84 B is an example of an elastically deformable member which supports the opening and closing valve  84 A, and which is elastically deformed by the air pressure in the cylindrical resin T received by the opening and closing valve  84 A and thereby moves the opening and closing valve  84 A. The spring member  84 B biases the opening and closing valve  84 A such that the opening and closing valve  84 A closes the upper communication path  82 A. Accordingly, a ventilation mechanism  81 , which discharges the air in the cylindrical resin T to the outside, includes the through-holes  82  and the changing devices  84 . 
     With this configuration, as illustrated in  FIG. 8A , if the air pressure in the cylindrical resin T transported between the ferrule  20  and the sizing die  80  is equal to or lower than the atmospheric pressure, the opening and closing valves  84 A close the upper communication paths  82 A with the biasing force of the spring members  84 B. 
     Further, as illustrated in  FIG. 8B , if the air pressure in the cylindrical resin T is higher than the atmospheric pressure, the air pressure is transmitted to the spring members  84 B via the opening and closing valves  84 A, and the spring members  84 B are deformed (contracted). Thereby, the opening and closing valves  84 A separate from and open the upper communication paths  82 A. 
     Further, as illustrated in  FIG. 8C , if the air pressure in the cylindrical resin T is further increased, the spring members  84 B are further deformed (further contracted). Thereby, the opening and closing valves  84 A further separate from and widely open the upper communication paths  82 A. 
     As described above, if the air pressure in the cylindrical resin T is high, the degree of opening (opening degree) of the upper communication paths  82 A opened by the opening and closing valves  84 A is greater than in a case where the air pressure in the cylindrical resin T is low. Accordingly, the air in the cylindrical resin T is effectively discharged to the outside. 
     Further, if the air pressure in the cylindrical resin T is equal to or lower than the atmospheric pressure, the opening and closing valves  84 A close the upper communication paths  82 A with the biasing force of the spring members  84 B. In this case, therefore, the air pressure in the cylindrical resin T is maintained. The fourth exemplary embodiment is similar to the first exemplary embodiment in the other operations. 
     Fifth Exemplary Embodiment: Subsequently, an example of a sizing mechanism  88  according to a fifth exemplary embodiment of the invention will be described in accordance with  FIGS. 9 to 11C . The same members as those of the first exemplary embodiment will be designated by the same reference numerals, and description thereof will be omitted. 
     As illustrated in  FIGS. 9 and 10 , a sizing die  90  of the sizing mechanism  88  according to the fifth exemplary embodiment is formed with two through-holes  92 , and is provided with changing devices  94 , each of which is an example of a changing unit that changes the flow rate of the air passing through the corresponding through-hole  92 . Accordingly, a ventilation mechanism  91 , which discharges the air in the cylindrical resin T to the outside, includes the through-holes  92  and the changing devices  94 . 
     Further, the sizing mechanism  88  is provided with a detection sensor  93  and a controller  95 . The detection sensor  93  is an example of a detection member which detects the air pressure in the cylindrical resin T transported between the ferrule  20  and the sizing die  90 . The controller  95  controls the changing devices  94  on the basis of the result of detection by the detection sensor  93 , to thereby change the flow rate of the air passing through the through-holes  92 . 
     Specifically, as illustrated in  FIG. 9 , each of the changing devices  94  includes a shutter member  96  and a stepping motor  98 . The shutter member  96  is movably supported to change an opening area of an upper opening portion of the corresponding through-hole  92 , and is formed with a rack gear  96 A at an end portion thereof. The stepping motor  98  has an output shaft fixed with a pinion gear  98 A meshed with the rack gear  96 A. The rotation direction and the rotation angle of the stepping motor  98  are controlled by the above-described controller  95 . 
     With this configuration, as illustrated in  FIGS. 9 and 11A , the detection sensor  93  detects, for example, that the air pressure in the cylindrical resin T transported between the ferrule  20  and the sizing die  90  is equal to the atmospheric pressure. In this case, the controller  95  controls the stepping motors  98  to move the shutter members  96  via the pinion gears  98 A and the rack gears  96 A and thereby close the respective opening portions of the through-holes  92  (reduce the respective opening areas to 0 mm 2 ). 
     Further, as illustrated in  FIGS. 9 and 11B , the detection sensor  93  detects that the air pressure in the cylindrical resin T transported between the ferrule  20  and the sizing die  90  is higher in value than the atmospheric pressure. In this case, the controller  95  controls the stepping motors  98  to move the shutter members  96  via the pinion gears  98 A and the rack gears  96 A and thereby open the opening portions of the through-holes  92  and increase the opening areas. 
     Further, as illustrated in  FIGS. 9 and 11C , the detection sensor  93  detects that the air pressure in the cylindrical resin T transported between the ferrule  20  and the sizing die  90  is further higher in value than the atmospheric pressure. In this case, the controller  95  controls the stepping motors  98  to move the shutter members  96  via the pinion gears  98 A and the rack gears  96 A and thereby open the opening portions of the through-holes  92  and further increase the opening areas. 
     As described above, if the air pressure in the cylindrical resin T is high, the degree of opening (opening degree) of the opening portions of the through-holes  92  is greater than in a case where the air pressure in the cylindrical resin T is low. Accordingly, the air in the cylindrical resin T is effectively discharged to the outside. The fifth exemplary embodiment is similar to the first exemplary embodiment in the other operations. 
     Specific exemplary embodiments of the invention have been described in detail. It is, however, apparent to practitioners skilled in the art that the invention is not limited to the exemplary embodiments, and that various other exemplary embodiments are possible within the scope of the invention. For example, the cylindrical resin T is cooled by the use of the fans  62  in the above-described exemplary embodiments. However, the sizing die may be formed with a water pipe and cooled by water running through the water pipe, to thereby cool the cylindrical resin T. 
     In the above-described exemplary embodiments, description has been made with reference to specific numbers of the members, openings, and so forth. However, the described numbers are examples, and the numbers of the members, openings, and so forth may be more or less than the described numbers. 
     In the above-described fifth exemplary embodiment, each of the shutter members  96  is moved by the use of the rack gear  96 A and the pinion gear  98 A. However, the shutter member  96  may be moved by the use of another structure. 
     In the above-described fifth exemplary embodiment, the two shutter members  96  are moved at the same time. However, only one of the shutter members  96  may be moved. 
     In the above-described fifth exemplary embodiment, each of the shutter members  96  is configured to be stopped during the movement thereof. However, the shutter member  96  may be configured to be moved only between an open position for opening the through-hole  92  and a close position for closing the through-hole  92 . 
     The foregoing description of the exemplary embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.