JP4289611B2 - Tenter device - Google Patents

Description

  The present invention relates to a tenter apparatus, and more particularly to a tenter apparatus for producing a sheet-like material such as a film having an orientation axis inclined at an arbitrary angle with respect to a side, regardless of the draw ratio.

  The demand for polarizing plates is rapidly increasing with the spread of liquid crystal display devices (hereinafter, LCDs). In general, a polarizing plate is formed by attaching a protective film to both surfaces or one surface of a polarizing layer having polarizing ability with an adhesive layer. As a material for the polarizing layer, polyvinyl alcohol (hereinafter referred to as PVA) is mainly used. After the PVA film is uniaxially stretched, it is dyed with iodine or a dichroic dye, or is stretched and dyed. A polarizing film for the polarizing layer is formed by crosslinking with. As the protective film, cellulose triacetate is mainly used because it is optically transparent and has a small birefringence. Usually, since the film is uniaxially stretched in the longitudinal direction, the absorption axis of the polarizing film is substantially parallel to the longitudinal direction.

  In the conventional LCD, the transmission axis of the polarizing plate is inclined by 45 ° with respect to the vertical or horizontal direction of the screen. Therefore, in the punching process of the polarizing plate manufactured in a roll form, Punched in the direction. However, when punched in the direction of 45 °, there was a portion that could not be used near the end of the roll, and there was a problem that the yield was reduced particularly with a large size polarizing plate.

  In recent years, the demand for retardation films has increased, and it is used to adhere to polarizing plates that form LCDs for the purpose of optical compensation such as coloring prevention and viewing angle expansion, and is oriented with respect to the transmission axis of the polarizing plate. There is a need to set the axis at various angles. Conventionally, from a film stretched vertically or laterally uniaxially, a method has been adopted in which the periphery is punched and cut so that the orientation axis is at a predetermined inclination angle with respect to the side, and the yield is reduced similarly to the polarizing plate. It was a problem.

  In order to solve this problem, several methods for inclining the orientation axis of the film to a desired angle with respect to the film transport direction have been proposed. For example, in Patent Document 1 and Patent Document 2, a plastic film is uniaxially stretched horizontally or longitudinally, and stretched in the longitudinal or lateral direction different from the previous stretching direction at different speeds on the left and right sides of the stretching direction. It has been proposed to incline the axis with respect to the uniaxial stretching direction.

  Further, in Patent Document 3, there are a plurality of pairs of left and right film holding points that form an angle θ with the running direction at the left and right ear ends of the continuous film, and each pair point can be extended in the direction of θ as the film runs There has been proposed a method for manufacturing a film having a stretching axis having an arbitrary angle θ with respect to the traveling direction of the film.

  Furthermore, in Patent Document 4, both ends of the film are gripped and run between two rows of chucks that run on tenter rails that are arranged so that the running distances of the chucks in the predetermined running section are different. A manufacturing method has been proposed in which the film is stretched in a direction oblique to the length direction.

  However, in the tenter devices described in Patent Document 1 and Patent Document 2, since both sides of the plastic film are gripped and stretched at different speeds, it is necessary to make a difference in the conveyance speed between the left and right, resulting in a twist caused by this. (Striped unevenness resulting from non-uniform tensile stress), wrinkles, and film deviation (local thickness unevenness) occur. For this reason, if it is going to make a left-right speed difference small, an extending process will become long and will lead to the increase in installation cost. The tenter device of Patent Document 3 also has the same problem as described above because the film traveling speed is changed between the left and right sides of the film. Further, in the tenter device of Patent Document 4, although the occurrence of creases and wrinkles due to the speed difference as described above is suppressed, it can be stretched only at a stretch ratio calculated in advance on a desk and patterned and fixed. There's a problem. As described above, in the conventional tenter apparatus, it is difficult to obtain a sheet-like material such as a film having an arbitrary stretching ratio at an arbitrary orientation angle.

Japanese Patent Laid-Open No. 50-83482 Japanese Patent Laid-Open No. 2000-9912 Japanese Patent Laid-Open No. 3-182701 Japanese Patent Laid-Open No. 2-113920

  In order to stretch the sheet-like material at an arbitrary orientation angle and at an arbitrary stretching ratio, the film is gripped by the gripping tools on the left and right rails, and the gripping tool from the start of gripping to the end of the substantial stretching. The length of the movement trajectory (hereinafter simply “substantially film gripping length”) is the same between the right and left, and the angle formed between the line connecting the substantial stretching end points of the left and right rails and the center line of the film after stretching. It is necessary to determine the left and right movement trajectory, that is, the bent shape of the rail so that is equal to the orientation angle α.

  For this reason, one or both of the left and right rails are connected to a linear first rail, a bendable curved rail portion coupled to the first rail, and a linear second rail coupled to the curved rail portion. And a tenter device that can be configured to independently change the distance in the film width direction of the left and right rails (for example, Japanese Patent Application No. 2002-8021). By the way, in such a tenter device, it is necessary to accurately calculate the length of the curved rail portion when determining the substantial film gripping length. For this purpose, it is easier to perform the calculation on the premise that the curved rail portion always maintains the arc shape, and the substantial film gripping length can be obtained with high accuracy. For this reason, it has been desired to develop a tenter device that accurately holds the shape of the curved rail portion in an arc shape.

  The present invention has been made in response to the above-mentioned demand, and is a tenter device capable of responding to changes in the orientation angle and the draw ratio by always maintaining the curved rail portion in an arc shape regardless of the change in the crossing angle. The purpose is to provide.

In the tenter device of the present invention, the plurality of gripping tools that travel along two rails arranged to face each other are gripped and moved on both side edges of the sheet-like material, and the sheet-like material is moved . In a tenter device that applies tension in a direction intersecting the conveyance direction to incline and extend an orientation axis of a sheet-like material , at least one of the rails is connected to the first rail portion and the first rail portion. A bendable bendable rail portion, a second rail portion connected to the bendable rail portion, a central portion of the bendable rail portion, and the second angle at the intersection angle between the first rail portion and the second rail portion. along the minute line you characterized in that it is composed of a curved rail holding means for sliding.

Still further, in the tenter device of the present invention, the curved rail holding means is connected to each other via a connecting shaft portion so as to be rotatable, and the first and second rails to which the first and second rail portions are respectively fixed. One end of the base, the support member, the drive unit, and the drive unit are pivotally connected to the first and second rail bases via the pivot shaft, and the other end is slidable and pivotable with the support member. And a frame member that slidably supports the vicinity of the center of the curved connection rail portion along the longitudinal direction, and the linear movement of the support member by the drive unit is caused to move to the other end of the frame member. It is preferable that the frame member is rotated so that the position on the bisector is transmitted.

  According to the present invention, at least one of the rails includes a first rail part, a bendable curved rail part coupled to the first rail part, a second rail part coupled to the curved rail part, Since the curved rail portion is configured by holding the central portion of the curved rail portion and sliding along the bisector at the intersection angle between the first rail portion and the second rail portion, the curved rail portion has an arc shape. And the substantial gripping length of the gripping tool can be obtained with high accuracy.

  FIG. 1 is a schematic plan view showing a tenter device of the present invention. The tenter device 10 includes a right rail 11, a left rail 12, endless chains (endless chains) 13 and 14 guided by the rails 11 and 12, film width adjusting sections 16 and 17, and angle adjusting sections. 20 to 23 and outlet position adjustment units 25 and 26, and the state of each unit is controlled by the controller 28. The tenter apparatus 10 is divided into areas of a preheating portion 10a, an extending portion 10b, and a heat treatment portion 10c in order from the entrance 31 side to the exit 32 of the film 30.

  A number of gripping tools (film clips) 33 are attached to the endless chains 13 and 14 at a predetermined pitch. The film clip 33 moves along the rails 11 and 12 while gripping the side edge of the film 30, thereby applying tension to the film 30, and the direction in which tension is applied is orthogonal to the transport direction of the film 30. By gradually inclining with respect to the width direction to be performed, the orientation axis of the sheet-like material is inclined with respect to the conveying direction.

  The endless chain 13 is stretched between a driving sprocket 34 as a wheel member and driven sprockets 35 and 36, and the endless chain 13 is guided by the right rail 11 between the sprockets 34 to 36. Similarly, the endless chain 14 is stretched between the driving sprocket 37 and the driven sprockets 38 and 39 and guided by the left rail 12. The central positions of the driving sprockets 34 and 37 are provided in accordance with the outlet 32 of the film 30, and the central positions of the driven sprockets 36 and 39 are provided in accordance with the inlet 31 of the film 30.

  An opening member (not shown) of the film clip 33 is disposed in the vicinity of the sprockets 34, 36, 37, 39. In the driving sprockets 36 and 39 on the entrance 31 side, the opening member comes into contact with an engaging portion (not shown) of the film clip 33 before the film 30 is gripped to open the side portion of the film 30. Is guided into the film clip 33. Then, when passing the gripping position, the opening member is separated from the engaging portion, the film clip 33 is set from the opening position to the gripping position, and the side edge portion of the film 30 is gripped. Similarly, in the driven sprockets 34 and 37 on the outlet 32 side, the film clip 33 is opened to the open position by the opening member at the grip release position of the film 30, and the grip of the side edge portion of the film 30 is released.

  The right rail 11 includes the sprockets 34 to 36, an extension side rail body 41 disposed between the sprockets 34 to 36, and a return side rail body 42. Similarly, the left rail 12 includes the sprockets 37 to 39, an extension side rail body 43 disposed between the sprockets 37 to 39, and a return side rail body 44.

  The extension side rail main body 41 and the return side rail main body 42 constituting the right rail 11 are respectively composed of entrance rail portions 41a and 42a, intermediate rail portions 41b and 42b, and exit rail portions 41c and 42c. Similarly, the extension side rail main body 43 and the return side rail main body 44 constituting the left rail 12 are also configured by entrance rail portions 43a and 44a, intermediate rail portions 43b and 44b, and exit rail portions 43c and 44c, respectively. Yes.

  The intermediate rail portion 41b is provided with curved connecting rail portions 41d and 41e on the upstream and downstream sides thereof. The curved connecting rail portions 41d and 41e connect the rail portions 41a to 41c so as to be bent. Similarly, the intermediate rail portions 43b, 44b, and 42b are provided with curved connecting rail portions 43d, 43e, 44d, 44e, 42d, and 42e on the upstream and downstream sides, respectively.

  The curved connecting rails 43e and 44e are attached with an angle adjusting unit 23 as a stretching ratio changing means for changing the stretching ratio and the orientation angle α of the film 30. The angle adjusting section 23 changes the bending angle of the curved connecting rail sections 43e and 44e. Similarly, the angle adjusting portions 20 to 22 are attached to the curved connecting rail portions 41d, 42d, 41e, 42e, 43d, and 44d, respectively.

  2 and 3 show the configurations of the angle adjusting portion 23 and the curved connecting rail portions 43e and 44e. The other angle adjusters 20 to 22 are similarly configured. The curved connecting rail portion 44e is composed of two bent rail members 47a and 47b. As shown in the enlarged view of FIG. 3, the bent rail members 47a and 47b are configured by overlapping a plurality of spring plates, and are slidably attached to the intermediate rail portion 44b and the outlet rail portion 44c. The curved connecting rail portion 43e is also composed of bent rail members 46a and 46b. When the angle is changed by the angle adjusting portion 23, the bent rail members 46a, 46b, 47a, 47b slide while sliding on the intermediate rail portions 43b, 44b and the outlet rail portions 43c, 44c, and the curved connecting rails. The angles at which the portions 43e and 44e are bent can be changed.

  The angle adjustment unit 23 includes rail bases 48 and 49, a connecting shaft 50, a lead screw rod 51, a motor 52, and a curved rail holding unit 53. The rail bases 48 and 49 are rotatably connected to each other via a connecting shaft 50. The rail base 48 includes intermediate rail portions 43b and 44b, and the rail base 49 includes outlet rail portions 43c and 44c. It is fixed. The curved rail holding portion 53 includes an arc holding frame 54, link levers 55 and 56, a slide pin 57, and a rail holding block 58. The arc holding frame 54 is rotatably attached to the rail bases 48 and 49 via the connecting shaft 50, and is attached to the arc holding frame 54 in the radial direction of the arc of the curved connecting rail portions 43e and 44e. A long-hole-shaped guide hole 54a is formed. One ends of the link levers 55 and 56 are rotatably connected to each other via a slide pin 57. The slide pin 57 is guided by the guide hole 54a and linearly moves in the guide hole 54a. The other ends of the link levers 55 and 56 are pivotally attached to the rail bases 48 and 49 via attachment pins 59 to constitute a four-bar linkage mechanism.

  A push block 60 is rotatably attached to the connecting shaft 50. The push block 60 is formed with a female screw portion, and a lead screw rod 51 is attached to the female screw portion. The push block 60, the lead screw rod 51 and the motor 52 constitute a moving means for the connecting shaft 50. The lead screw rod 51 is rotationally driven by the motor 52, and the motor 52 is controlled by the controller 28 via the driver 61. Is done. Therefore. When the motor 52 rotates, the connecting shaft 50 moves via the lead screw rod 51, thereby changing the angle of the angle adjusting unit 23.

  With this angle change, the arc holding frame 54 is positioned on a line that bisects the crossing angle of the rail bases 48 and 49 via the link levers 55 and 56. A long hole-shaped guide hole 54b is formed in the arc holding frame 54 at a position closer to the connecting shaft 50 than the above-described guide hole 54a, and a rail holding block 58 is slidably mounted in the guide hole 54b. It has been. Since the rail holding block 58 holds the central portions of the bent rail members 46a, 46b, 47a, 47b, the rail holding block 58 is always curved in a substantially arc shape regardless of the size of the crossing angle of the rail bases 48, 49. .

  FIG. 4 shows the configuration of the outlet position adjusting portion 26 of the left rail 12. The outlet position adjusting portion 26 includes outlet rail portions 43c and 44c, a width direction rail portion 61, a driving sprocket 37, a driven sprocket 38, a slide. The frame 64, the frame driving unit 65, the sprocket base 66, and the base moving unit 67 are included. The exit rail 43c is arranged so as to go straight to the position of the driving sprocket 37. At a position between the driving sprocket 37 and the driven sprocket 38, a width direction rail portion 61 is disposed along a width direction N orthogonal to the transport direction M of the film 30. And the exit rail part 44c is arrange | positioned so that it may return toward the exit rail part 43c from the position of the driven sprocket 38. FIG.

  The exit rail portion 43c includes an expansion / contraction portion upstream side 68a and an expansion / contraction portion downstream side 68b. Since the convex portion 71 on the downstream side of the telescopic portion 68b and the concave portion 72 on the upstream side of the telescopic portion 68a are slidably fitted along the feed direction of the endless chain 6, the exit rail portion 43c is telescopic. . In addition, the width direction rail part 61 and the exit rail part 44c are also the same structure as the exit rail part 43c, and are each comprised from the expansion-contraction part upstream 69a, 70a and the expansion-contraction part downstream 69b, 70b. The extension rail upstream side 68 a of the exit rail portion 43 c is fixed to the rail base 49 described above, and the extension portion downstream side 68 b is fixed to the frame 67.

  The slide frame 64 supports the driving sprocket 37, the width direction rail portion 61, the sprocket base 66, and the base moving portion 67, and moves by driving the frame driving portion 65. The frame drive unit 65 includes a lead screw rod 73 screwed into a female screw portion provided on the slide frame 67, a motor 74 for rotating the lead screw rod 73, and a guide shaft 75 arranged along the width direction N. Under the control of the controller 28, the motor 74 rotates and moves the slide frame 64 along the guide shaft 75.

  The sprocket base 66 is attached to the driven sprocket 38, the expansion / contraction section downstream side 69b of the width direction rail section 61, and the expansion / contraction section upstream side 70a of the exit rail section 44c. The base moving unit 67 has the same configuration as the frame driving unit 65 and includes a lead screw rod 78, a motor 79, and a guide shaft 80. The base moving unit 67 moves the sprocket base 66 relative to the slide frame 64 along the width direction N. By the movement of the sprocket base 66, the distance between the sprocket 37 and the sprocket 38 is changed, and the telescopic portion downstream side 69b slides following this, and the width direction rail portion 61 is shortened or extended.

  Further, the telescopic part upstream side 70 a of the exit rail part 44 c is rotatably attached to the sprocket base 66, and the telescopic part downstream side 70 b is rotatably attached to the rail base 49. . The movement of the sprocket base 66 causes the telescopic portion upstream side 70a to follow the sprocket base 66 and slide along the width direction N and to rotate with respect to the sprocket base 66 to shorten or extend the exit rail portion 44c.

  The frame driving unit 65 constitutes the exit position adjusting unit 26 and also serves as a film width adjusting unit. Similarly, the entrance rail portion 43a is provided with a film width adjusting portion 17 as a film width adjusting means. The film width adjusting unit 17 includes a lead screw rod 81 and a motor 82, and can adjust the entrance width W1. The right rail 11 has the same configuration, and is provided with an exit position adjustment unit 25 and a film width adjustment unit 16 that have substantially the same configuration as the exit position adjustment unit 26 and the film width adjustment unit 17.

  When the stretching ratio is changed, the right entrance rail portions 41a and 42a are translated in a direction perpendicular to the film transport direction by the film width adjusting unit 16 and the angle adjusting units 20 and 21 described above. Further, the left entrance rail portions 43a and 44a are translated in the direction perpendicular to the film transport direction by the film width adjusting portion 17 and the angle adjusting portions 22 and 23. These film width adjusting sections 16 and 17 and angle adjusting sections 20 to 23 determine the width of the film entrance 31 in accordance with the width W1 of the film 30 to be supplied.

  The controller 28 is provided with a data input unit 84 such as a keyboard, and set values such as a tenter entrance width W1, a draw ratio N, and an orientation angle α can be input. Instead of the draw ratio N, the film exit width W2 may be input. The controller 28 is preliminarily programmed with a drawing pattern arithmetic expression, and this is stored in the memory 85. When the set values of the tenter entrance width W1, the draw ratio N (or the exit width W2), and the orientation angle α are input to the controller 28, the controller 28 determines that the left and right chains 13 and 14 are substantially subtracted from the arithmetic expression based on these set values. Film gripping lengths LA and LB (LA = LB, where LA is the moving locus length of the film clip 33 from PA1 to PA2 and LB is the moving locus length of the film clip 33 from PB1 to PB2) The angle adjustment units 20 to 23 and the film width adjustment units 16 and 17 are driven so as to obtain the obtained positions, and the rail portions 41a to c, 42a to c, 43a to c are driven. 44a-c are displaced in the width direction.

  That is, the angle adjusting units 20 to 23 and the film width adjusting units 16 and 17 are driven so that the set tenter entrance width W1 and the draw ratio N are set, and the opening angles of the rails 11 and 12 are set. Is changed so that an oblique film having an arbitrary orientation angle α (10 ° ≦ α ≦ 80 °) can be obtained at an arbitrary stretch ratio (W2 / W1).

  Next, the operation of this embodiment will be described. First, the tenter entrance width W1, the exit width W2, and the tilt angle α of the orientation axis are input from the data input unit 84. When these data are input, the controller 28 drives each of the angle adjusting units 20 to 23 and the film width adjusting units 16 and 17 using an arithmetic expression.

  When the lead screw rod 51 is rotated by the rotation of the motor 52, the connecting shaft 50 is moved. Accordingly, the intermediate rail portions 43b and 44b and the outlet rail portion 44b are displaced together with the rail bases 48 and 49, and the angle at which the curved connecting rail portions 43e and 44e are bent is changed. At this time, as described above, the curved connecting rail portions 43e and 44e are always curved in a substantially arc shape regardless of the size of the crossing angle of the rail bases 48 and 49. Therefore, the endless chain 6 can smoothly move on the curved connecting rail portions 43a and 44a. And since it hold | maintains in a substantially circular arc shape, when calculating the substantial gripping length of the curved connection rail parts 43a and 44a, this substantial gripping length can be calculated | required accurately.

It is a top view including the functional block which shows the outline of the tenter apparatus of this invention. It is a perspective view which shows the structure of an angle adjustment part. It is the top view which looked at the angle adjustment part from upper direction. It is a top view which shows the structure of an exit position adjustment part.

Explanation of symbols

2 Tenter device 11, 12 Rail 13, 14 Endless chain 30 Film 14 Grip tool 53 Curved rail holding part 54 Arc holding frame 55, 56 Link lever 57 Slide pin 58 Rail holding block

Claims (2)

Tension in a direction that intersects the conveying direction of the sheet-like material while gripping and moving both side edges of the sheet-like material by a plurality of gripping tools that run along two rails arranged so as to face each other In a tenter device that extends and tilts the orientation axis of the sheet-like material,
At least one of the rails includes a first rail portion, a bendable curved rail portion coupled to the first rail portion, a second rail portion coupled to the curved rail portion, and a center of the curved rail portion. A tenter device comprising: a curved rail holding means that holds a portion and slides along a bisector at an intersection angle between the first rail portion and the second rail portion. The curved rail holding means is rotatably connected to each other via a connecting shaft portion, and the first and second rail bases to which the first and second rail portions are fixed are connected to each other via the connecting shaft portion. A pair of link levers that are pivotably connected and pivotally attached to the first rail base and the second rail base to form a four-bar link mechanism; a connecting shaft portion of the pair of link levers; It is rotatably attached to one of the connecting shaft portions of each rail base, and is slidably held on the other of the connecting shaft portions of the pair of link levers and the connecting shaft portion of each rail base, and is bisected. A frame member positioned on a line, and a slide member that holds a central portion of the curved rail portion and is slidably held on the bisector by the frame member. 1 tenter device as claimed.

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