TW201900381A - Film forming device including a control device and a mold device that has an inner circumference member, an outer circumference member, and an adjustment unit - Google Patents

Abstract

The present invention provides a film forming device. The film forming device of the present invention comprises: a mold device, which extrudes molten resin in a tubular shape to form a film; and a control device (7), which controls the mold device. The mold device includes: an inner circumference member defining an inner circumference of an annular discharge port; an outer circumference member surrounding the inner circumference member and defining an outer circumference of the discharge port; and an adjustment unit, which elastically deforms at least one of the inner circumference member and the outer circumference member by imposing a load thereto, so as to vary a width of the discharge port in a radial direction. The control device (7) controls the thickness of the film by the load given by the adjustment unit.

Description

 Film forming device  

The present invention relates to a film forming apparatus.

There is known a film forming apparatus which is formed by solidifying a molten resin which is tubularly extruded from an annular discharge port of a die device and formed into a film. In the mold apparatus provided in the conventional film forming apparatus, the outer peripheral member of the outer peripheral opening of the annular discharge port is pressed by a bolt and elastically deformed, whereby the width of the discharge port is locally changed (Patent Document 1). . By locally changing the width of the discharge port, the thickness of the film can be locally controlled in the circumferential direction.

 (previous technical literature)    (Patent Literature)  

Patent Document 1: Japanese Laid-Open Patent Publication No. 2012-166365

In the conventional film forming apparatus described in Patent Document 1, the amount of movement (the amount of screwing) of the bolt that presses the outer peripheral member is managed to control the thickness of the film. However, the vicinity of the mold device becomes a relatively high temperature due to heat for melting the resin, and thus the bolt that presses the outer peripheral member may be thermally expanded by the heat. In the case where the amount of movement of the bolt is managed to control the thickness of the film, this thermal expansion adversely affects its accuracy.

The present invention has been made in view of such circumstances, and an object thereof is to provide a film forming apparatus capable of controlling the thickness of a film with high precision.

In order to solve the above problems, a film forming apparatus according to an aspect of the present invention includes a mold device that molds a molten resin into a tubular shape and forms a film, and a control device that controls the mold device. The mold apparatus includes: an inner peripheral member defining an inner circumference of the annular discharge port; an outer peripheral member surrounding the inner peripheral member and defining an outer circumference of the discharge port; and an adjustment portion by at least one of the inner circumferential member and the outer peripheral member The load is imparted and elastically deformed to change the width of the discharge port in the radial direction. The control device controls the thickness of the film by the load given by the adjustment portion.

Further, any combination of the above constituent elements, or constituent elements and expressions of the present invention are mutually replaced by methods, apparatuses, systems, and the like, and are also effective as aspects of the present invention.

According to the present invention, it is possible to provide a film forming apparatus capable of controlling the thickness of a film with high precision.

1‧‧‧Film forming device

2‧‧‧Molding device

3‧‧‧Cooling device

6‧‧‧ thickness sensor

7‧‧‧Control device

10‧‧‧Mold body

12‧‧‧ inner week components

14‧‧‧peripheral components

16‧‧‧Regulatory Department

80‧‧‧ Keeping Department

81‧‧‧Acquisition Department

82‧‧‧Decision Department

83‧‧‧Adjustment Action Control Department

Fig. 1 is a view showing a schematic configuration of a film forming apparatus according to a first embodiment.

Figure 2 is a cross-sectional view showing the upper portion of the mold apparatus of Figure 1 and its periphery.

3 is a top plan view of the mold apparatus of FIG. 1.

Fig. 4 is a perspective view showing an upper portion of the outer peripheral member of Fig. 2 and an adjusting portion attached thereto.

Fig. 5 is a side view showing an upper portion of the outer peripheral member of Fig. 2 and an adjusting portion attached thereto.

Fig. 6 is a perspective view showing the adjusting portion of Fig. 2;

Fig. 7 is a perspective view showing the adjusting portion of Fig. 2;

8(A) and 8(B) are explanatory views for explaining the operation of the adjustment unit.

Fig. 9 is a block diagram schematically showing the function and structure of the control device of Fig. 1.

Fig. 10 is a partially enlarged cross-sectional view showing the configuration of an adjustment portion of the film forming apparatus of the second embodiment.

Fig. 11 is a partially enlarged cross-sectional view showing the configuration of an adjustment portion of the film forming apparatus of the third embodiment.

Fig. 12 is a partially enlarged cross-sectional view showing the configuration of an adjustment portion of the film forming apparatus of the fourth embodiment.

(A) and (B) are views showing the configuration of an adjustment portion of the film forming apparatus of the fifth embodiment.

Fig. 14 is a cross-sectional view showing the upper portion of the mold device of the film forming apparatus according to the modification and its periphery.

Fig. 15 is a partially enlarged sectional view showing the structure of the adjusting portion of Fig. 14.

Fig. 16 is a cross-sectional view showing the upper portion of the mold device of the film forming apparatus according to another modification and its periphery.

Fig. 17 is a partially enlarged cross-sectional view showing the structure of the adjusting portion of Fig. 16.

Fig. 18 is a cross-sectional view showing the upper portion of the mold device of the film forming apparatus according to another modification and its periphery.

In the following, the same or equivalent constituent elements and members are denoted by the same reference numerals, and the description thereof will be omitted as appropriate. Further, for easy understanding, the size of the members in the respective drawings is appropriately enlarged and reduced. Further, in each of the drawings, a part of the members which are not important in the embodiment will be omitted.

 (First embodiment)  

Fig. 1 shows a schematic configuration of a film forming apparatus 1 according to the first embodiment. The film forming apparatus 1 is used to form a tubular film. The film forming apparatus 1 includes a mold device 2, a cooling device 3, a pair of stabilizing plates 4, a pair of pinch rolls 5, a thickness sensor 6, and a control device 7.

The mold device 2 forms a molten resin supplied from an extruder (not shown) into a tubular shape. In particular, the mold apparatus 2 forms the molten resin into a tubular shape by extruding the molten resin from the annular slit 18 (described later in FIG. 2). The cooling device 3 is disposed above the mold device 2. The cooling device 3 blows the cooling air from the outside with respect to the molten resin extruded from the mold device 2. The molten resin is cooled to be formed into a film.

The pair of stabilizing plates 4 are disposed above the cooling device 3, and guide the formed film between the pair of pinch rolls 5. The pinch roller 5 is disposed above the stabilizing plate 4, pulls the guided film up and folds it flat. The folded film is wound by a winder (not shown).

The thickness sensor 6 is disposed between the cooling device 3 and the stabilizing plate 4. The thickness sensor 6 is rotated about the tubular film and the thickness of the film is measured. The measurement result generated by the thickness sensor 6 is sent to the control device 7. The control device 7 transmits a control command corresponding to the measurement result received from the thickness sensor 6 to the mold device 2. The mold device 2 receives the control command to adjust the width of the slit 18 (especially its discharge port) in such a manner that the thickness unevenness becomes small.

Fig. 2 is a cross-sectional view showing the mold device 2 and its periphery. 3 is a plan view of the mold device 2. In Fig. 3, the representation of the cooling device 3 is omitted.

The cooling device 3 includes an air cooling ring 8 and an annular flow regulating member 9. The air cooling ring 8 is an annular casing that is recessed downward in the inner peripheral portion. An annular air outlet 8a that is open on the upper side is formed in the inner peripheral portion of the air cooling ring 8. In particular, the air outlet 8a is formed concentrically with the annular slit 18 centered on the central axis A.

In the following description, the direction parallel to the central axis A is referred to as the axial direction, and the arbitrary direction of the central axis A on the plane perpendicular to the central axis A is set to the radial direction, and the radial direction is close to the center. One side of the axis A is set as the inner peripheral side, and one side away from the central axis A is set as the outer peripheral side, and the direction of the circumference of the circle centered on the central axis A on the plane perpendicular to the central axis A is set as the circumference. direction.

In the outer peripheral portion of the air cooling ring 8, a plurality of hose ports 8b are formed at equal intervals in the circumferential direction. A hose (not shown) is connected to each of the plurality of hose ports 8b, and the cooling air is sent into the air cooling ring 8 from the air blower (not shown) via the hose. The cooling air sent into the air cooling ring 8 is blown out from the air outlet 8a and blown onto the molten resin.

The flow regulating member 9 is disposed in the air cooling ring 8 so as to surround the air outlet 8a. The flow regulating member 9 rectifies the cooling air sent into the air cooling ring 8. Thereby, the cooling air is blown out from the air outlet 8a at a uniform flow rate and wind speed in the circumferential direction.

The mold apparatus 2 includes a mold main body 10, an inner peripheral member 12, an outer peripheral member 14, and a plurality of (here, 32) adjustment portions 16. The inner peripheral member 12 is a substantially cylindrical member placed on the upper surface of the mold body 10. The outer peripheral member 14 is an annular member and surrounds the inner peripheral member 12. A slit 18 that is annular and extends in the vertical direction is formed between the inner peripheral member 12 and the outer peripheral member 14. The molten resin flows through the slit 18 toward the upper side, and the molten resin is extruded from the discharge port (that is, the upper end opening) 18a of the slit 18, and is cooled in the cooling device 3 to be formed to correspond to the width of the discharge port 18a. Thick film. A plurality of heaters 56 are mounted on the outer circumference of the mold body 10. Further, a heater 56 is also attached to the outer periphery of the lower portion of the outer peripheral member 14 (specifically, the large diameter portion 27 to be described later). The mold body 10 and the peripheral member 14 are heated to a desired temperature by the heater 56. Thereby, the molten resin flowing through the inside of the mold device 2 can be maintained at an appropriate temperature and a molten state.

The plurality of adjustment portions 16 are arranged substantially without a gap in the circumferential direction so as to surround the upper end side of the outer peripheral member 14. In particular, the adjustment portion 16 is attached to the outer peripheral member 14 in a cantilever shape. The cooling device 3 is fixed above the plurality of adjustment portions 16. Each of the plurality of adjustment portions 16 can provide the outer peripheral member 14 with a pressing load on the inner side in the radial direction or a tensile load on the outer side in the radial direction. Therefore, by adjusting the plurality of adjustment portions 16, the width of the discharge port 18a can be locally adjusted in the circumferential direction, and the thickness of the film can be locally controlled in the circumferential direction. In the case where unevenness in thickness occurs in the film, for example, the adjustment portion 16 corresponding to a portion having a thin wall thickness (for example, located below a portion having a thin wall thickness) is given a tensile load to the outer peripheral member 14, and is enlarged. A gap between the discharge port 18a below the portion having a thin wall thickness. Thereby, the unevenness of the film thickness is made small.

4 and 5 are a perspective view and a side view showing the upper portion of the outer peripheral member 14 and the adjusting portion 16 attached thereto. In FIGS. 4 and 5, only one adjustment unit 16 is shown, and the representation of the remaining adjustment unit 16 is omitted. 6 and 7 are perspective views showing the adjustment unit 16. Fig. 7 shows a state in which one of the pair of support members 30 is detached.

The upper portion of the outer peripheral member 14 has a small diameter portion 25 formed at the upper end, a middle diameter portion 26 formed to have a larger diameter than the small diameter portion 25 below the small diameter portion 25, and a large diameter portion 27 at the middle diameter. The lower portion of the portion 26 is formed to have a larger diameter than the intermediate diameter portion 26. The small diameter portion 25 has a flexible lip portion 22. The flexible lip portion 22 is a portion of the small diameter portion 25 that is located above the concave notch portion 20 provided along the circumferential direction. The flexible lip portion 22 is elastically deformed by the notch portion 20 as a boundary. The flexible lip portion 22 includes a cylindrical main body portion 28 and an annular projecting surrounding portion 29 that protrudes outward in the radial direction from the main body portion 28.

The adjusting portion 16 includes a pair of supporting members 30 attached to the outer peripheral member 14 and a rotating shaft 32 fixed to the pair of supporting members 30. The lever 34 is supported to be rotatable with the rotating shaft 32 as a fulcrum; the operating lever 36 accepts a rotation force due to the lever 34 moves in the axial direction; the coupling member 38 connects the actuating lever 36 and the flexible lip 22 in the axial direction; the bearing member 40 supports the actuating lever in the axial direction; and the actuator 24, imparting a rotational force to the lever 34.

The pair of support members 30 are formed in a flat plate shape, and are fixed to the outer peripheral member 14 by screws in parallel with each other. A space is provided between the pair of support members 30 to allow the lever 34 to intervene. The bearing member 40 is formed in a rectangular parallelepiped shape, and is fixed to the outer peripheral member 14 by screws at the inner side in the radial direction of the support member 30. An insertion hole 42 penetrating in the radial direction is formed in the bearing member 40. The inner peripheral surface of the insertion hole 42 constitutes a so-called sliding bearing (a bearing without oil supply type), and the operating rod 36 is slidably supported.

The rotating shaft 32 is fixed to the pair of supporting members 30 such that its axis faces the horizontal direction and is substantially orthogonal to the radial direction.

The action lever 36 is formed in a cylindrical shape having a step, and a middle portion thereof is inserted through the insertion hole 42 of the bearing member 40. A reduced diameter portion 44 is provided on the outer side in the radial direction of the operating lever 36. As will be described later, the reduced diameter portion 44 functions as a joint portion with the lever 34. A concave engaging portion 46 is provided on the inner side in the radial direction of the operating lever 36. As will be described later, the engaging portion 46 can function as a connecting portion with the connecting member 38. The outer peripheral surface (hereinafter referred to as "pressure receiving surface 23") of the protruding surrounding portion 29 of the flexible lip portion 22 faces the front end of the operating lever 36.

The connecting member 38 is formed in a bifurcated shape when viewed in a longitudinal section. Specifically, in the connecting member 38, the engaging portions 48 and 50 projecting downward are provided on the surface facing the outer peripheral member 14 in the axial direction. The engaging portion 48 has a substantially complementary shape with the engaging portion 46 of the operating lever 36. Further, an annular engagement groove 52 that is recessed downward in the axial direction is formed in the protruding surrounding portion 29 of the flexible lip portion 22. The engaging portion 50 and the engaging groove 52 have a substantially complementary shape.

The actuating lever 36 and the connecting member 38 are screwed by the engaging portion 48 being engaged with the engaging portion 46 and the engaging portion 50 being engaged with the engaging groove 52. The opposing surface of the engaging portion 48 and the engaging portion 46 is a tapered surface. Thereby, with the locking screw 54, the front end surface of the actuating lever 36 is pressed against the pressure receiving surface 23 of the flexible lip 22, and the actuating lever 36 and the flexible lip 22 are firmly fixed together. A part of the flexible lip portion 22 is sandwiched by the engaging portion 50 of the connecting member 38 and the front end portion of the operating lever 36. Thereby, the actuating lever 36 is connected to the flexible lip 22 in the axial direction thereof.

The lever 34 has a long plate-like body 60 extending in the radial direction, and one end portion thereof is rotatably supported by the rotating shaft 32. The lever 34 is disposed such that the body 60 and the actuating lever 36 are substantially parallel in a non-operating state. Further, a branching portion 62 having a bifurcated shape is provided so as to extend from one end portion of the main body 60 in a direction perpendicular to the axis of the main body 60. In other words, the connecting portion 62 is constituted by the pair of connecting pieces 64, and is configured such that the interval therebetween is slightly larger than the outer diameter of the reduced diameter portion 44 of the operating lever 36, and the width thereof is slightly smaller than the length of the reduced diameter portion 44. . With such a configuration, the lever 34 and the actuating lever 36 are coupled to each other with the connecting portion 62 fitted to the reduced diameter portion 44.

In addition, the configuration is not limited to the present embodiment as long as the rotational force of the lever 34 is directly applied to the operating lever 36. For example, the connecting portion 62 may be configured not to extend in the vertical direction from the axis of the body 60. The axis of the body 60 and the extending direction of the connecting portion 62 may also be acute or obtuse. Further, the lever 34 may be such that the body 60 is not parallel to the operating lever 36 in a non-operating state.

In the present embodiment, the actuator 24 is of a pneumatic drive type, and includes two sets of bellows 70 and 72, bellows 71 and 73, and a first base 75 that are operated by supply and discharge of compressed air, and are disposed in The second base 76 on the lower side in the axial direction of the first base 75 and the four connecting rods 77 are provided. The first pedestal 75 and the second pedestal 76 are disposed apart from each other in the axial direction, and are connected by four connecting rods 77. Bellows 70 and 72 are disposed between the lever 34 and the first base 75, and bellows 71 and 73 are disposed between the lever 34 and the second base. That is, the end portion of the lever 34 that becomes the point of application is supported so as to be sandwiched between the bellows 70, 72 and the bellows 71, 73. By supplying compressed air to one of the bellows 70, 72 or the bellows 71, 73, the lever 34 is rotationally driven in the clockwise or counterclockwise direction in the drawing.

In Fig. 5, when the bellows 70, 72 are extended by applying pressure to the bellows 70, 72 by the supply of compressed air, the lever 34 is rotated counterclockwise in the drawing, and the rotational force is converted to the axial direction of the operating lever 36. The force on the left side (ie, the outer side in the radial direction). As a result, the tensile load is applied to the flexible lip portion 22, and the gap of the portion corresponding to the discharge port 18a of the slit 18 (that is, the inner side in the radial direction of the adjustment portion 16) is changed in the increasing direction. On the other hand, when the bellows 71, 73 are extended by applying pressure to the bellows 71, 73 by the supply of compressed air, the lever 34 is rotated clockwise in the drawing, and the rotational force is converted to the axial direction of the operating lever 36. The force on the right side (ie, the inner side in the radial direction). As a result, the pressing load is applied to the flexible lip portion 22, and the gap of the portion corresponding to the slit 18 is changed in the direction of reduction.

In order to realize such air pressure driving, compressed air is supplied from a pressure adjusting device (not shown) via a supply path 75a formed in the first susceptor 75 or a supply path 76a supplied to the second susceptor 76. The pressure adjusting device controls the pressure in the bellows 70 to 73 in accordance with a control command from the adjustment operation control unit 83 (described later).

FIG. 8 is an explanatory diagram for explaining the operation of the adjustment unit 16. 8(A) shows the neutral state of the adjustment unit 16 (the bellows 70 to 73 are in a non-operating state), and FIG. 4(B) shows the expanded operation state of the adjustment unit 16 (only the states of the bellows 70 and 72 are operated). ).

By the adjustment portion 16, the rotational force of the lever 34 can be directly applied to the action lever 36 at the point of action P. That is, the rotational force of the lever 34 is imparted to the flexible lip portion 22 as a force in the axial direction of the operating lever 36. At this time, since the actuating lever 36 is stably supported by the outer peripheral member 14, the force in the axial direction can be efficiently transmitted to the flexible lip portion 22. As a result, the driving force for adjusting the gap between the inner peripheral member 12 and the outer peripheral member 14 can be effectively functioned.

In the present embodiment, as shown in Fig. 8(A), the connection point of the connection lever 34 and the operating lever 36 (the point of action P of the lever 34) and the line L1 of the rotating shaft 32 (the fulcrum of the lever 34) are configured. The axis L2 of the rod 36 is orthogonal. Thereby, the tangential direction of the virtual circle C passing through the action point P around the rotation axis 32 coincides with the axial direction of the operating lever 36.

Therefore, as shown in FIG. 8(B), the direction of the action point P of the rotational force of the lever 34 coincides with the axial direction of the operating lever 36. As a result, the rotational force of the lever 34 becomes the driving force in the axial direction of the operating lever 36, and the force transmission efficiency can be maximized. In other words, the driving force of the actuator 24 when the flexible lip portion 22 is expanded can be efficiently operated (see a thick arrow in the drawing).

Although not shown in the figure, in the narrowed operation state of the adjustment portion 16 (only the bellows 71 and 73 are operated), only the direction of the force in FIG. 8(B) is opposite, and the rotational force of the lever 34 acts. The direction on P still coincides with the axial direction of the action lever 36. As a result, similarly to the case of the expansion operation, the rotational force of the lever 34 directly becomes the driving force in the axial direction of the operating lever 36, and the force transmission efficiency can be maximized. In other words, the adjustment portion 16 can effectively act to drive the driving force for adjusting the interval of the discharge port 18a of the slit 18.

In addition, the configuration is not limited to the present embodiment as long as the rotational force of the lever 34 is directly applied to the operating lever 36. For example, the direction in which the connecting portion 62 extends (the direction in which the rotating shaft 32 and the point of action P are connected) and the axial direction of the operating lever 36 are at an acute angle or an obtuse angle, and the point of action of the rotational force of the lever 34 can be made. The upward direction (also referred to as "rotational force acting direction" for convenience) is inconsistent with the axial direction of the action lever 36 (also referred to as "axial force acting direction" for convenience). In this case, the body 60 may be parallel to the actuating lever 36, and the axis of the body 60 may be at an acute or obtuse angle with the extending direction of the connecting portion 62. Alternatively, the axis of the body 60 may be at a right angle to the direction in which the connecting portion 62 extends, and the body 60 may be non-parallel to the operating rod 36. Alternatively, the axis of the body 60 may be at an acute or obtuse angle with the direction in which the connecting portion 62 extends, and the body 60 and the actuating rod 36 may be non-parallel. Further, as the body 60, a structure having at least a part having a bent portion or a bent portion (which does not necessarily define an axis) may be employed.

Fig. 9 is a block diagram schematically showing the function and structure of the control device 7. The blocks shown here can be realized by hardware or a device represented by a CPU of a computer, and can be realized by a computer program or the like on a software. Here, the drawing is realized by integration of the same. Function block. Therefore, those skilled in the art can understand that these functional blocks can be implemented in various forms by a combination of hardware and software.

The control device 7 includes a holding unit 80, an acquisition unit 81, a determination unit 82, and an adjustment operation control unit 83. The acquisition unit 81 acquires the measurement result generated by the thickness sensor 6. The holding portion 80 holds the thickness of the film in association with the load to be applied to the outer peripheral member 14 by the adjusting portion 16. More specifically, the holding portion 80 holds the thickness of the film in association with the load applied to the outer peripheral member 14 by the adjustment portion 16 in order to make the thickness of the film having the thickness targeted.

The determination unit 82 determines the load applied to the outer peripheral member 14 by each of the adjustment units 16 in order to reduce the thickness unevenness. In particular, the determination unit 82 refers to the thickness measured by the thickness sensor 6 and the holding portion 80, and determines the load to be applied to the outer peripheral member 14. Further, in order to give the determined load to the outer peripheral member 14, the determining unit 82 calculates how much the pressure of the bellows 70 to 73 of the adjusting unit 16 is to be controlled. The adjustment operation control unit 83 transmits a control command to the pressure adjustment device such that the pressure of the bellows 70 to 73 is the pressure calculated by the determination unit 82.

The operation of the film forming apparatus 1 configured as above will be described.

The control device 7 grasps the unevenness of the thickness of the film by the measurement result generated by the thickness sensor 6, and controls each of the adjustment portions 16 of the mold device 2 so as to reduce the unevenness of the thickness. When the control device 7 is to apply a pressing load to the adjustment portion 16, the pressure of the bellows 71, 73 of the adjustment portion 16 is increased to rotate the lever 34 in the clockwise direction. Further, when the control device 7 is to apply the tensile load to the adjustment portion 16, the pressure of the bellows 70, 72 of the adjustment portion 16 is increased to rotate the lever 34 in the counterclockwise direction.

According to the film forming apparatus 1 of the present embodiment described above, the load applied to the outer peripheral member 14 by the adjusting portion 16 is determined in accordance with the thickness of the film measured by the thickness sensor 6. Here, since the periphery of the mold device 2 is heated to a relatively high temperature by the heat for melting the resin, the operating lever 36 and the lever 34 are thermally expanded by the heat. Therefore, for example, depending on the thickness of the film to be measured, the amount of displacement of the operating rod 36 is managed to a desired value, and when the thickness of the film is controlled, the accuracy may be adversely affected. On the other hand, in the present embodiment, the thickness of the film to be measured is controlled so that the load applied to the outer peripheral member 14 by the operating rod 36 (that is, the adjusting portion 16) is a desired value, thereby controlling the film. thickness. Therefore, even if the operating lever 36 and the lever 34 are expanded by heat, the thickness of the film can be controlled with high precision.

Further, according to the film forming apparatus 1 of the embodiment, the rotational force of the actuator 24 is transmitted to the flexible lip portion 22 via the lever 34. That is, the rotational force of the actuator is amplified by the principle of the lever and transmitted to the flexible lip 22. Therefore, the output required for the actuator 24 can be reduced. Therefore, for example, the number of bellows required for the actuator 24 can be reduced. Alternatively, the size of the bellows can be reduced.

 (Second embodiment)  

Next, a second embodiment will be described. The adjustment portion of the present embodiment is the same as that of the first embodiment except that the connection structure between the operating lever and the flexible lip is different. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals, and their description will be omitted. Fig. 10 is a partially enlarged cross-sectional view showing the configuration of an adjusting portion of the second embodiment.

In the present embodiment, the male screw portion 240 is provided on the inner side in the radial direction of the operating lever 236. A nut 242 is screwed to the proximal end portion of the male screw portion 240. On the other hand, the connecting member 238 has a U-shaped longitudinal section, and an internal thread portion 244 that can be screwed into the male screw portion 240 is formed in the upper portion thereof.

In this configuration, the male screw portion 240 is screwed to the extent that the internal thread portion 244 is penetrated, so that the front end surface of the operating lever 236 is pressed against the pressure receiving surface 23 of the flexible lip portion 22, and the actuating lever 236 is The flexible lips 22 are securely fastened together. At this time, the fixing of the operating lever 236 and the coupling member 238 can be stabilized by the lock nut 242. At this time, a part of the flexible lip portion 22 is sandwiched by the engaging portion 50 of the connecting member 238 and the distal end portion of the operating lever 236, whereby the operating lever 236 is connected to the flexible lip portion 22 in the axial direction.

 (Third embodiment)  

Next, a third embodiment will be described. The adjustment portion of the present embodiment is the same as the second embodiment except that the connection structure between the operating lever and the flexible lip is different. Therefore, the same components as those in the second embodiment are denoted by the same reference numerals, and their description will be omitted. Fig. 11 is a partially enlarged cross-sectional view showing the configuration of an adjusting portion of a third embodiment.

In the present embodiment, as in the second embodiment, the male screw portion 240 is provided at the lower portion of the operating lever 336, and the nut 242 is screwed to the proximal end portion. On the other hand, instead of the engagement groove 52, the protruding portion 29 of the flexible lip portion 22 is provided with a female screw portion 344 extending inward in the radial direction from the pressure receiving surface 23, and is configured such that the male screw portion 240 can be in the axial direction. Screwing.

In such a configuration, the operating rod 336 and the flexible lip portion 22 can be directly coupled by screwing the male screw portion 240 to the female screw portion 344. At this time, the actuating lever 336 and the flexible lip portion 22 can be firmly fixed by the lock nut 242. At this time, by adjusting the amount of screwing of the male screw portion 240 to the female screw portion 344, the positional relationship between the operating lever 336 and the lever 34 can be set with high precision. That is, the direction of the action point P of the rotational force of the lever 34 can be made to coincide with the axial direction of the operating lever 336.

 (Fourth embodiment)  

Next, a fourth embodiment of the present invention will be described. The adjustment unit of the present embodiment is the same as the first embodiment except that the connection structure between the operating lever and the lever is different. Fig. 12 is a partially enlarged cross-sectional view showing the configuration of an adjusting portion of a fourth embodiment.

In the present embodiment, the screw 420 is assembled in the axial direction on the outer circumferential side end portion of the operating lever 436, and the reduced diameter portion 444 is formed between the outer circumferential side end of the operating lever 436 and the head of the screw 420. Further, the connecting portion 62 of the lever 34 is assembled to the reduced diameter portion 444. With this configuration, it is not necessary to process the reduced diameter portion 44 on the outer circumferential surface of the operating rod 36 as in the first embodiment. The reduced diameter portion 444 requires high precision in terms of the action point P, and the manufacturing cost can be reduced by omitting the cutting process or the like. Further, for example, by increasing the locking strength of the screw 420, the operating lever 436 and the lever 34 can be more firmly coupled.

 (Fifth Embodiment)  

Next, a fifth embodiment will be described. The adjustment unit of the present embodiment is the same as the first embodiment except that the connection structure between the operating lever and the lever is different. Fig. 13 is a view showing the configuration of an adjustment unit according to the fifth embodiment. Fig. 13(A) is a partially enlarged cross-sectional view showing a connecting portion between the operating lever and the lever and its peripheral structure, and Fig. 13(B) is a front view of the operating lever.

In the present embodiment, a fork-shaped arm portion 540 is provided at an outer circumferential side end portion of the operating lever 536, and a rotating shaft 544 is provided across the arm portion 540. On the other hand, the connecting portion 562 of the lever 534 does not extend in a flange shape as in the first embodiment, but is provided with a through hole 546 for inserting the rotating shaft 544 through the center. The connecting portion 562 is rotatably coupled to the rotating shaft 544. With this configuration, the position of the rotating shaft 544 becomes the point of action of the lever 534. Since the lever 534 is relatively rotatable relative to the connecting portion of the operating lever 536, when the operating lever 536 is largely displaced, it is possible to prevent an excessive load from being applied to the operating point P.

The structure and operation of the film forming apparatus of the embodiment have been described above. These embodiments are illustrative, and those skilled in the art can understand that various combinations of the constituent elements can be variously modified, and such modifications are also within the scope of the invention.

 (Modification 1)  

Fig. 14 is a cross-sectional view showing the upper portion of the mold device 2 of the film forming apparatus according to the modification and its periphery. Figure 14 corresponds to Figure 2. Fig. 15 is a partially enlarged sectional view showing the structure of the adjusting portion of Fig. 14; Fig. 15 corresponds to Fig. 8(A). In the present modification, the extending direction of the connecting portion 62 (the direction connecting the rotating shaft 32 and the point of action P) is an obtuse angle with the axis of the body 60. In the non-operating state of the lever 34, the axis of the body 60 does not match the axis of the operating lever 36. parallel. Since the load is applied to the outer peripheral member 14 by the rotational force of the actuator, the axis of the body 60 can be configured such that the axis of the body 60 is not parallel to the axis of the operating rod 36. In this case, the degree of freedom in arrangement of the adjustment unit 16 is improved.

 (Modification 2)  

Fig. 16 is a cross-sectional view showing the upper portion of the mold device 2 and the periphery thereof of the film forming apparatus according to another modification. Figure 16 corresponds to Figure 2. Fig. 17 is a partially enlarged cross-sectional view showing the structure of the adjusting portion of Fig. 16. Fig. 17 corresponds to Fig. 8(A). In the present modification, the adjustment portion 16 is disposed such that the outer peripheral member 14 is biased toward the upper side in the axial direction. According to the film forming apparatus of the present modification, the same operational effects as those exhibited by the film forming apparatus of each embodiment can be exhibited.

 (Modification 3)  

In the case described in the embodiment, the adjustment portion 16 is disposed outside the outer peripheral member 14, and the outer peripheral member 14 is elastically deformed by applying a load of pressing or stretching to the outer peripheral member 14. However, the present invention is not limited thereto. The adjustment portion 16 may elastically deform the outer peripheral member 14 by applying a load to the inner peripheral member 12, thereby partially changing the width of the discharge port of the slit 18 in the radial direction. In this case, the inner peripheral member 12 may be formed to be hollow, and the adjustment portion 16 may be disposed in the hollow portion. Further, for example, the holding portion 80 can hold the thickness of the film in association with the load applied to the inner peripheral member 12 by the adjustment portion 16 in order to make the film having the thickness targeted.

 (Modification 4)  

In the case described in the embodiment, the holding portion 80 holds the thickness of the film in association with the load applied to the outer peripheral member 14 by the adjustment portion 16 in order to make the thickness of the film having the thickness targeted, but does not Limited to this. The holding portion 80 may hold information on the relationship between the thickness of the film and the load applied to the outer peripheral member 14 by the regulating portion 16. For example, the holding portion 80 may hold a relational expression indicating the relationship between the thickness of the film and the load applied to the outer peripheral member 14 by the adjustment portion 16 in order to make the thickness of the film having the thickness targeted. In this case, the determination unit 82 determines the load to be applied to the outer peripheral member 14 by the plurality of adjustment portions 16 by reducing the thickness unevenness by using the relational expression. Further, in order to apply the determined load to the outer peripheral member 14, the determining unit 82 may calculate the pressure of the bellows 70 to 73 of the adjusting unit 16 to be controlled.

Further, the holding portion 80 may associate the thickness of the film with the pressure of the bellows 70 to 73 for applying the load applied to the outer peripheral member 14 to adjust the thickness of the film having the thickness. Keep it. In this case, the determination unit 82 may determine the pressure of the bellows 70 to 73 by referring to the thickness measured by the thickness sensor 6 and the holding portion 80.

 (Modification 5)  

In the embodiment, both the tensile load and the pressing load are applied to the flexible lip portion by the operation of the lever and the operating lever by the driving of the actuator. In other words, the operation of expanding the flexible lip portion or the narrowing operation can be performed from the neutral state of the adjustment portion. In the modified example, only one of the tensile load and the pressing load may be applied to the flexible lip portion, and only the expansion operation or the narrowing operation of the flexible lip portion may be performed. For example, one end side of the actuating lever 36 may be connected, and only one of the pressing direction and the stretching direction is given to the flexible lip 22 to apply a force (driving force). In this case, when the accumulating force via the operating lever 36 is released, the flexible lip 22 can return to the state before the accumulating force is applied by the elasticity or the like.

 (Modification 6)  

In the embodiment, when the air blower is used as the actuator 24, when one of the bellows 70, 72 or the bellows 71, 73 is supplied with compressed air, the other is connected to the atmosphere. In the modification, the compressed air may be supplied to both of the bellows 70 and 72 and the bellows 71 and 73 to cause a pressure difference therebetween, thereby imparting a tensile load or a pressing load to the flexible lip. For example, the pressure difference can be generated by providing individual pressure regulating valves to the bellows 70, 72 and the bellows 71, 73.

 (Modification 7)  

In the embodiment, the bellows 70 and 72 for stretching and the bellows 71 and 73 for pressing are provided on both sides of one lever. In the modification, the bellows may be provided on only one side of one of the levers, and the bellows may be pressurized or depressurized to operate the lever in the stretching direction or the pressing direction.

 (Modification 8)  

In the embodiment, the actuator 24 is pneumatically driven, but it may be a hydraulic or hydraulic drive. Further, although the bellows is exemplified as a circular shape, other shapes such as a rectangle may be employed. Further, an actuator other than the motor drive may be employed.

 (Modification 8)  

Fig. 18 is a cross-sectional view showing the upper portion of the mold device 2 and the periphery thereof of the film forming apparatus according to another modification. Figure 18 corresponds to Figure 2.

In the present modification, the heater 56 is also attached to the outer circumference of the upper portion of the outer peripheral member 14, specifically, the outer circumference of the small diameter portion 25 of the outer peripheral member 14. In the upper portion of the outer peripheral member 14, the temperature of the molten resin is easily lowered by the influence of the cooling air from the air cooling ring 8, and the heater 56 is attached to the outer periphery of the small-diameter portion 25, so that a more appropriate temperature and a molten state can be obtained. The molten resin is maintained, and as a result, the quality of the film can be improved. Further, in the present modification, as in the embodiment, the thickness of the film is controlled so that the load applied to the outer peripheral member 14 becomes a desired value, so that the heat for melting the resin is caused. When the member constituting the adjustment portion 16 is inflated, the thickness of the film can also be controlled with high precision. Therefore, the heater 56 can be attached to the outer circumference of the small diameter portion 25 of the outer peripheral member 14.

Further, in the present modification, the small-diameter portion 25 is formed such that a portion of the small-diameter portion 25 that is lower than the protruding surrounding portion 29, that is, a deformed portion that is elastically deformed, is axially oriented, as compared with the first embodiment. lengthen. Thereby, the variable amount of the flexible lip portion 22 becomes large, and the adjustment range of the thickness of the film becomes large.

Further, when the inner peripheral member 12 is formed to be hollow, the heater 56 may be attached to the inner circumference of the inner peripheral member 12 instead of the outer circumference of the upper portion of the outer peripheral member 14 or in addition to the outer periphery of the upper portion of the outer peripheral member 14.

Any combination of the above-described embodiments and modifications is also useful as an embodiment of the present invention. The new embodiment produced by the combination has the effects of each of the combined embodiments and modifications.

 [Industrial Applicability]  

According to the present invention, it is possible to provide a film forming apparatus capable of controlling the thickness of a film with high precision.

Claims (8)

 A film forming apparatus comprising: a mold device for extruding a molten resin into a film to form a film; and a control device for controlling the mold device, wherein the mold device includes an inner peripheral member defining an annular shape An inner circumference of the discharge port; an outer peripheral member surrounding the outer peripheral member and defining an outer circumference of the discharge port; and an adjustment portion that elastically deforms at least one of the inner peripheral member and the outer peripheral member by applying a load thereto The width of the discharge port in the radial direction is changed, and the control device controls the thickness of the film by the load given by the adjustment portion.    The film forming apparatus according to claim 1, further comprising: a measuring unit that measures a thickness of the film, wherein the control device includes a determining unit that determines the adjusting unit according to a thickness measured by the measuring unit The correlation value of the load to be applied; and the adjustment operation control unit to operate the adjustment unit based on the value determined by the determination unit.    The film forming apparatus according to claim 2, wherein the control device includes a holding unit that holds information on a relationship between a thickness of the film and a load to be applied to the adjusting portion, and the determining unit is based on the aforementioned The thickness measured by the measuring unit and the information held by the holding unit determine the correlation value of the load given by the adjusting unit.    The film forming apparatus according to any one of claims 1 to 3, wherein the adjustment unit includes an actuator that outputs a rotational force, and the load is imparted by the rotational force of the actuator.    The film forming apparatus according to claim 4, wherein the adjusting portion comprises: a lever supported to be supported by a rotating shaft whose position is fixed with respect to the mold device, and which receives the actuator a rotational force; and an action rod supported by the mold device to be displaceable in the axial direction and supported by the action point of the lever; the rotational force of the lever is converted into a force in the axial direction of the action rod, the axial direction The force acts as a load on the inner peripheral member or the outer peripheral member, and the lever directly applies a force to the operating rod at the point of action of the lever.    The film forming apparatus according to claim 5, wherein a line connecting the point of action of the lever and the rotating shaft and the actuating lever is provided in a state in which the inner peripheral member and the outer peripheral member are not biased. The axes are orthogonal, whereby the direction of the aforementioned point of action of the rotational force of the aforementioned lever coincides with the axial direction of the action rod.    The film forming apparatus according to claim 5, further comprising: a connecting member that connects the operating rod and the inner peripheral member or the outer peripheral member, wherein the operating rod is opposed to the inner peripheral member or the outer peripheral member The position is adjusted by the aforementioned connecting member.    The film forming apparatus according to claim 5, wherein the body of the lever including the point of application of the lever is substantially parallel to the action lever.