JP2006192856A - Casting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control variations in the angular velocity of rotation of an endless belt or a drum for forming a film and to improve the uniformity of thickness of a plastic film. <P>SOLUTION: The casting apparatus 1 consists of an endless belt 7 which has a surface on which a molten plastic 9 is cast to form a film and also rotatively travels, and a driving motor 19 which rotatively drives this endless belt 7. Further, the above driving motor 19 consists of a built-in type, and this built-in type driving motor 19 is directly connected to the rotary shaft 11 of the endless belt 7 for the drive. Because the apparatus has a constitution freed from eccentricity and backlash, which become factors of the variation of angular velocity, by getting rid of rotation transfer apparatuses and the like comprising universal joints, centering work, speed reducers, pulleys, flat belts and the like, the uniformity of thickness of the plastic film 33 is improved. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a casting apparatus, and more particularly to a casting apparatus that can suppress fluctuations in the rotational angular velocity of an endless belt or drum for forming a film of molten plastic.

  Conventionally, a casting apparatus is a belt type in which, for example, a steel belt is rotated so as to rotate as an endless belt having a surface on which a film made by casting a plastic melted with a solvent or the like is cast. Or a drum type casting apparatus in which a drum having a film forming surface is provided so as to rotate. The molten plastic is extruded from the die onto the surface of the steel belt or drum in the form of a curtain, and then dried and stretched (see, for example, Patent Document 1 and Patent Document 2).

  Referring to FIGS. 5A and 5B, a conventional belt-type casting apparatus 101 includes a die 109 on the surface of an endless steel belt 107 that is driven to rotate by two drums 103 and 105. The molten plastic 111 extruded from is dropped.

  6A and 6B, as a conventional drum type casting apparatus 113, the molten plastic 111 extruded from the die 109 is dropped directly onto the surface of one drum 115. It is.

  In any of the above casting apparatuses 101 and 113, both ends of the rotating shaft 117 of the drum 103, the rotating shaft 119 of the drum 105, and the rotating shaft 121 of the drum 115 are supported by bearings 123. Further, in the casting apparatus 101, one end of the rotating shaft 117 of the drum 103 is connected to the speed reducer 127 and the drive motor 129 via the universal joint 125 or other joints in order to rotate one drum 103. In the casting apparatus 113, one end of the rotating shaft 121 of the drum 115 is connected to the speed reducer 127 and the drive motor 129 via a universal joint 125 and the like in order to rotate the drum 115.

  5A and 6A, in any of the casting apparatuses 101 and 113, the pulley between the speed reducer 127 and the rotating shaft 117 (or 121) of the drum 103 (or 115) is a pulley. It is transmitted by a rotation transmission device 135 composed of 131 and a flat belt 133. However, depending on the casting device, the rotation transmission device 135 is not provided, and the reduction gear 127 and the rotation shaft 117 (or 121) of the drum 103 (or 115) are connected via a universal joint 125. There are also things.

The universal joint 125 is used to absorb misalignment of the rotation shafts of the drive motor 129, the speed reducer 127, the drums 103 and 115, and the like.
Japanese Patent Laid-Open No. 11-58425 JP 2002-127228 A

  By the way, in the conventional belt type casting apparatus 101, if the steel belt 107 or the drums 103 and 105 have an angular velocity fluctuation, the thickness accuracy in the flow direction of the plastic film is deteriorated. The rotational drive system of the drums 103 and 105 is important.

  For example, if the rotation shafts 117 and 119 of the drums 103 and 105 are misaligned, the rotation angular velocity of the drums 103 and 105 may be changed. Therefore, the steel belt 107 or the drums 103 and 105 wound around the drums 103 and 105 Since the speed fluctuated, there was a problem that this resulted in uneven thickness of the plastic film.

  This problem also applies to the conventional drum type casting apparatus 113.

  Accordingly, the rotary shafts 117, 119, and 121 are centered at the time of assembling the casting apparatuses 101 and 115, the cores are assembled so that the cores are aligned as much as possible, and a universal joint 125 is provided to absorb the misalignment. Although it is used, it is difficult to completely align the core, and even when the universal joint 125 is used, fluctuations in angular velocity cannot be completely suppressed.

  Further, a transmission such as the speed reducer 127 causes a gear gear cutting error, a pitch error, a backlash, and the like, which is a major factor in fluctuations in angular velocity. Further, in the rotation transmission device 135 including the pulley 131 and the flat belt 133, the joint of the flat belt 133, the elongation of the belt itself, and the like are factors of the angular velocity fluctuation.

  Therefore, in high-accuracy film deposition, there is a demand for a method for driving the steel belt 107 or the drums 103, 105, and 115 with less variation in angular velocity.

  The present invention has been made to solve the above-described problems.

A casting apparatus according to the present invention comprises a casting motor comprising a surface on which a melted plastic is cast to form a film, and an endless belt or drum that rotates and a drive motor that rotationally drives the endless belt or drum. In the device
The drive motor is of a built-in type, and the built-in type drive motor is directly connected to the rotation shaft of the endless belt or drum.

  In the casting apparatus according to the present invention, in the casting apparatus, the front drive motor includes a rotor, a stator coil member that rotates the rotor, and a housing that supports the stator coil member. It is preferable that the endless belt or the rotating shaft of the drum is fixed integrally.

  In the casting apparatus according to the present invention, in the casting apparatus, the drive motor includes a rotor, a stator coil member that rotates the rotor, and a housing that supports the stator coil member, and the rotor is endless. It is preferable to connect directly to the rotating shaft of the belt or drum via a joint member.

  In the casting apparatus according to the present invention, in the casting apparatus, the drive motor generates a transmission pulse of 9000 pulses / 1 rotation or more at the rear end of the rotor in order to control the rotational speed of the rotor. Is preferably connected directly.

  In the casting apparatus of the present invention, in the casting apparatus, the drive motor is preferably an 18-pole or 42-pole multipole servomotor.

  As can be understood from the means for solving the above problems, according to the present invention, the drive motor is a built-in type, and the rotary shaft of the drum and the drive motor are directly connected, so that the universal joint, the core Since it is possible to eliminate the unloading operation, the reduction gear, the rotation transmission device including a pulley, a flat belt, and the like, it is possible to make a configuration free from misalignment or backlash that causes the angular velocity fluctuation of the endless belt or drum. As a result, fluctuations in the angular velocity of the drum and the steel belt can be reduced, and the uniformity of the thickness of the plastic film can be improved.

  In addition, since the centering work as in the prior art is eliminated, the assembly time can be shortened, and the number of constituent members is reduced, so that the casting apparatus can be reduced in size.

  Embodiments of the present invention will be described below with reference to the drawings.

  1A and 1B, a casting apparatus 1 according to this embodiment forms a film on the surface of, for example, a steel belt 7 as an endless belt that is driven to rotate by drums 3 and 5. This is a belt type casting apparatus for dropping the molten plastic 9 to be used.

  In this type of casting apparatus 1, two drums 3, 5 are rotatably supported at both ends of rotary shafts 11, 13 via bearings 15, and endlessly between the two drums 3, 5. Steel belt 7 is stretched. Further, a die 17 for extruding the molten plastic 9 to flow on the surface of the steel belt 7 is disposed above the one drum 3 in FIG.

  A built-in type drive motor 19 is directly connected to one end of the rotating shaft 11 of one drum 3. That is, the drive motor 19 includes a bearing housing 23 that supports one end side of the rotating shaft 11 via the bearing 21, a motor housing 25 fixed to the bearing housing 23, and a stator coil member fixed to the inside of the motor housing 25. For example, a motor stator 27 and a rotor 29 (motor rotor) that is located inside the motor stator 27 and is fixed to the extension shaft portion 11A of the rotating shaft 11. Therefore, in the first embodiment, the rotating shaft 11 of the drum 3 and the rotor 29 of the drive motor 19 are directly connected integrally.

  In this embodiment, the peripheral speed of the drums 3 and 5 is 0.3 m / min. Therefore, for example, when the diameter of the drums 3 and 5 is 800 mm, the rotational speed of the rotary shaft 11 is 0.12 rpm, and when the diameter of the drums 3 and 5 is 2200 mm, the rotational speed of the rotary shaft 11 is 0.044 rpm. Thus, when the diameters of the drums 3 and 5 are 3500 mm, the rotational speed of the rotary shaft 11 is 0.028 rpm.

  Thus, since the drive motor 19 is a motor for ultra-low speed rotation, it is desirable that the motor stator 27 is configured by a multipole system having 18 poles to 42 poles. That is, since the drive motor 19 is a multi-pole servo motor, it is possible to perform more stable ultra-low speed operation by positioning control.

  The motor housing 25 is provided with, for example, a rotary encoder 31 as an encoder for detecting the rotation speed of the extension shaft portion 11A of the rotation shaft 11 and controlling the rotation speed. It is desirable that the rotary encoder 31 has a high accuracy for generating a transmission pulse of 9000 pulses / rotation or more.

  With the above configuration, the molten plastic 9 is pushed out of the die 17 and dropped onto the surface of the steel belt 7. When the film is dried and returned to the lower position of the one drum 3 and dried into a film, it is peeled off as a plastic film 33.

  As described above, the drive motor 19 is a built-in type, and the rotary shaft 11 of the drum 3 and the rotor 29 of the drive motor 19 are directly connected to each other, so that a universal joint, a centering operation, a speed reducer, a pulley, A rotation transmission device such as a flat belt can be eliminated. That is, a configuration in which there is no misalignment or backlash that causes fluctuations in the angular velocity of the drum 3 can be achieved.

  As a result, the angular velocity fluctuations of the drums 3 and 5 and the steel belt 7 are reduced, and as a result, the thickness uniformity of the plastic film can be improved and highly accurate film formation can be performed.

  Further, since the conventional centering operation is eliminated, the assembly time of the casting apparatus 1 can be shortened. In addition, since the number of parts constituting the casting apparatus 1 is reduced, there are various advantages such as a reduction in the size of the casting apparatus 1.

  Further, since the rotary encoder 31 is directly connected to the rear end portion of the extension shaft portion 11A directly connecting the rotor 29 of the drive motor 19, it is not affected by the twist of the rotary shaft 11 (or the extension shaft portion 11A). Detection errors can be reduced.

  Furthermore, since the rotary encoder 31 has high accuracy to generate a transmission pulse of 9000 pulses / rotation or more, the detection error can be controlled to be small.

  Next, a casting apparatus 35 according to a second embodiment of the present invention will be described. In addition, since it is basically the same as the casting apparatus 1 of the first embodiment described above, the same members are denoted by the same reference numerals, detailed description thereof is omitted, and only different portions will be described.

  2A and 2B, the casting apparatus 35 according to the second embodiment is a drum-type casting apparatus that drops the molten plastic 9 directly onto the surface of the drum 37. Therefore, this type of casting apparatus 35 is different from the casting apparatus 1 of the first embodiment described above in that it does not have the steel belt 7 and is configured by one drum 37, and the other configurations are the same. is there. The drive motor 19 that rotationally drives the rotary shaft 39 of the drum 37 is the same as that in the first embodiment. That is, the rotor 29 (motor rotor) of the drive motor 19 is integrally fixed to the extension shaft portion 39 </ b> A of the rotation shaft 39 of the drum 37.

  With the above configuration, the molten plastic 9 is pushed out of the die 17 and dropped onto the surface of the drum 37, and the molten plastic 9 is placed on the surface of the drum 37 and dried while making one round. In (B), when the film returns to the right position and is dried into a film, it is peeled off as a plastic film 33.

  Therefore, similarly to the first embodiment, the drive motor 19 is a built-in type, and the rotational shaft 39 of the drum 37 and the rotor 29 of the drive motor 19 are directly connected integrally, so that the angular velocity fluctuation of the drum 37 is changed. It can be set as the structure which does not have misalignment and backlash which become the factor of this. Thereby, the angular velocity fluctuation of the drum 37 is reduced, and as a result, the uniformity of the thickness of the plastic film 33 can be improved and highly accurate film formation can be performed.

  Other advantages are the same as those of the first embodiment.

  Next, a casting apparatus 41 according to a third embodiment of the present invention will be described. In addition, since it is basically the same as the casting apparatus 1 of the first embodiment described above, the same members are denoted by the same reference numerals, detailed description thereof is omitted, and only different portions will be described.

  Referring to FIG. 3, a casting apparatus 41 according to the third embodiment is a belt-type casting apparatus that drops molten plastic 9 on a steel belt 7 driven by drums 3 and 5, This is almost the same as the casting apparatus 1 of the embodiment.

  The difference from the casting apparatus 1 of the first embodiment is that, for example, a universal joint 45 as a joint member is provided at one end of the rotating shaft 43 of one drum 3, and is connected to the drive motor 47 via the universal joint 45. There is in being. That is, in the drive motor 47, the rotor shaft portion 51 to which the rotor 49 is integrally fixed is supported by the bearing housing 23 via the bearing 21, and one end of the rotor shaft portion 51 is interposed via the universal joint 45. It is directly connected to the rotating shaft 43 of the drum 3. That is, this configuration is used when it is difficult to directly connect the rotating shaft 43 of the drum 3 to the rotor 49 of the drive motor 47.

  However, even if there is the above-mentioned universal joint 45 in the casting device 41, there is no speed reducer which is a major factor of fluctuation in angular velocity, and no rotation transmission device consisting of a pulley or a flat belt. The fluctuation of the angular velocity of the steel belt 7 is reduced, and as a result, the thickness and uniformity of the plastic film 33 can be improved, and highly accurate film formation can be performed. Other advantages are the same as those of the first embodiment.

  Next, a casting apparatus 53 according to a fourth embodiment of the present invention will be described. In addition, since it is basically the same as the casting apparatus 35 of the second embodiment described above, the same members are denoted by the same reference numerals, detailed description thereof is omitted, and only different portions will be described.

  Referring to FIG. 4, a casting apparatus 53 according to the fourth embodiment is a drum-type casting apparatus that directly drops molten plastic 9 onto the drum 5, and a casting apparatus according to the second embodiment. It is almost the same as 35.

  The difference from the casting apparatus 35 of the second embodiment is that, for example, a universal joint 57 as a joint member is provided at one end of the rotating shaft 55 of the drum 37, and is connected to the drive motor 47 via the universal joint 57. There is to be. The method for connecting the drive motor 47 and the drum 37 is the same as in the third embodiment. That is, in the drive motor 47, the rotor shaft portion 51 to which the rotor 49 is integrally fixed is supported by the bearing housing 23 via the bearing 21, and one end of the rotor shaft portion 51 is connected via the universal joint 57. It is directly connected to the rotating shaft 55 of the drum 37. That is, this configuration is used when it is difficult to directly connect the rotating shaft 55 of the drum 37 to the rotor 49 of the drive motor 47.

  However, even if the universal joint 57 is provided in the casting device 53, since there is no speed reducer and a rotation transmission device composed of a pulley or a flat belt, which is a major factor of the angular velocity fluctuation, the angular velocity fluctuation of the drum 37 is not present. As a result, the thickness and uniformity of the plastic film 33 can be improved, and highly accurate film formation can be performed. Other advantages are the same as those of the second embodiment.

(A) is a top view of the casting apparatus of 1st Embodiment of this invention, (B) is a partial front view of (A). (A) is a top view of the casting apparatus of 2nd Embodiment of this invention, (B) is a partial front view of (A). It is a top view of the casting apparatus of 3rd Embodiment of this invention. It is a top view of the casting apparatus of 4th Embodiment of this invention. (A) is a top view of the conventional belt type casting apparatus, (B) is a partial front view of (A). (A) is a top view of the conventional drum type casting apparatus, (B) is a partial front view of (A).

Explanation of symbols

1 Casting device (of the first embodiment)
3, 5 Drum 7 Steel belt (endless belt)
9 Molten plastic 11, 13 Rotating shaft 11A Extension shaft 17 Die 19 Drive motor 23 Bearing housing 25 Motor housing 27 Motor stator (stator coil member)
29 Rotor 35 Casting device (of the second embodiment)
37 Drum 39 Rotating shaft 39A Extension shaft portion 41 Casting device (of the third embodiment)
43 Rotating shaft 45 Universal joint (joint member)
47 Drive motor 49 Rotor 51 Rotor shaft 53 Casting device (of the fourth embodiment)
55 Rotating shaft 57 Universal joint (joint member)

Claims (5)

In a casting apparatus comprising an endless belt or drum that has a surface on which a melted plastic is cast to form a film and rotates, and a drive motor that rotationally drives the endless belt or drum.
The casting apparatus according to claim 1, wherein the drive motor is a built-in type, and the built-in type drive motor is directly coupled to the endless belt or the rotating shaft of the drum.   The drive motor includes a rotor, a stator coil member that rotates the rotor, and a housing that supports the stator coil member, and the rotor is integrally fixed to a rotation shaft of an endless belt or a drum. The casting apparatus according to claim 1.   The drive motor includes a rotor, a stator coil member that rotates the rotor, and a housing that supports the stator coil member, and the rotor is directly connected to the rotation shaft of an endless belt or drum via a joint member. The casting apparatus according to claim 1.   The drive motor is directly connected to a high-precision encoder that generates a transmission pulse of 9000 pulses / 1 rotation or more at the rear end of the rotor in order to control the rotational speed of the rotor. 3. The casting apparatus according to 3. 5. The casting apparatus according to claim 1, wherein the driving motor is a multipole servomotor having 18 poles or 42 poles.

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