JP7292250B2 - Film stretching equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a film stretching apparatus for stretching a thin film-like stretching object such as a sheet or a film.

Conventionally, as a film stretching apparatus, clips for gripping a thin film-shaped object to be stretched such as a sheet or a film are arranged symmetrically in a plan view on endlessly connected clip links, and the clip interval of the clips is adjusted as a guide. There is a transverse stretching machine that performs transverse stretching (TD stretching) in a direction across the rails while gradually enlarging the film with the rails. Also known is a shrink tenter which, in addition to a structure similar to that of the horizontal stretching machine, has a mechanism for shrinking the gap between clips in the clip link, and which can shrink in the vertical direction at the same time as the horizontal stretching.

For example, in the clip link described in Patent Document 1, a link arm is pushed forward by a pushing rail from the rear of the clip link, thereby contracting an object to be stretched in the vertical direction.

Japanese Patent No. 5371523

However, according to the structure of the link arm of the film stretching apparatus described in Patent Document 1, the link arm can be pushed forward by the pushing rail from the rear of the clip link, but conversely, it cannot be pulled backward from the front. could not.

Therefore, when the contractile force of the object to be stretched is large, the contractile force of the object to be stretched pushes the link arm arbitrarily from the rear to the front even if the pushing of the link arm is not released. It was possible. As a result, there is a problem that the shrinkage rate in the longitudinal direction cannot be controlled.

Further, in the film stretching apparatus described in Patent Document 1, the link arm is pushed forward at the entrance of the object to be stretched, the object to be stretched is gripped by the clip in a state where the clip pitch is reduced, and in the stretching zone, The clip pitch can be widened by releasing the push of the link arm. However, when the contraction force of the object to be stretched is large, even if the pushing of the link arm is released and the object to be stretched is to be longitudinally stretched, the link arm remains in the pushed state, causing the object to be stretched to be vertically stretched. There is a problem that the film cannot be stretched.

The present invention has been made in view of the above, and is a film stretching apparatus that can reliably control the clip spacing in both the shrinking direction and the expanding direction, in contrast to clips for conventional shrink tenters. intended to provide

In order to solve the above-described problems and achieve the object, the film stretching apparatus according to the present invention holds the ends of the film in the width direction with a plurality of clips, and the clip links formed by the plurality of clips are connected. In a film stretching device that stretches the film while transporting it by running, a reference rail that is arranged along the transport direction of the film and guides the clip link and the reference rail that is adjacent to the A first gap adjusting rail provided with a gap corresponding to the clip gap of the clip, a second gap adjusting rail provided parallel to the first gap adjusting rail, and supporting the clip a first roller rotating around the first shaft member while contacting the reference rail ; The first shaft member is sandwiched between a second roller that rotates around a second shaft member parallel to the shaft member and two first rollers that respectively support the adjacent clips. a third shaft member installed in parallel with, the second shaft member, and one of the first shaft members that respectively pivotally support the two first rollers that support the adjacent clips; A link member integrally supporting the third shaft member , the other of the first shaft members, and the third shaft member are connected to each other such that the interval between the adjacent first rollers can be changed. and the angle of the link member is changed according to the distance between the connecting member and the distance between the reference rail and the first distance adjustment rail or the distance between the reference rail and the second distance adjustment rail. and a clip interval adjusting mechanism for adjusting the clip interval between the clips respectively supported by the adjacent first rollers connected by the link member and the connecting member .

ADVANTAGE OF THE INVENTION The film stretching apparatus which concerns on this invention is effective in the ability to control reliably the clip space|interval in both the contraction direction and the expansion direction.

FIG. 1 is an overall schematic diagram of a film stretching apparatus according to a first embodiment. FIG. 2 is a plan view of a clip link used in the film stretching device according to the first embodiment. FIG. 3 is a side view of the clip used in the film stretching apparatus according to the first embodiment, viewed from the upstream side in the conveying direction. FIG. 4 is a cross-sectional view taken along line AA of FIG. FIG. 5 is a plan view showing an example of a state in which clip intervals of clip links used in the film stretching apparatus according to the first embodiment are changed. FIG. 6 is a side view of the clip viewed from the upstream side in the conveying direction in a state where the clip interval is narrowed. FIG. 7 is a side view of the clip used in the film stretching apparatus according to the second embodiment, viewed from the upstream side in the conveying direction. FIG. 8 is a side view of the clip used in the film stretching apparatus according to the third embodiment, viewed from the upstream side in the conveying direction. FIG. 9 is a plan view of a clip link used in the film stretching device according to the fourth embodiment. FIG. 10 is a side view of the clip used in the film stretching apparatus according to the fourth embodiment, viewed from the upstream side in the conveying direction.

An embodiment of the clip link mechanism of the simultaneous biaxial stretching device according to the present disclosure will be described below in detail based on the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be replaced and easily conceived by those skilled in the art, or those that are substantially the same.

(First embodiment)
[Description of schematic configuration of film stretching device]
First, the overall configuration of a film stretching apparatus 10a according to the first embodiment will be described with reference to FIG. FIG. 1 is an overall schematic diagram of a film stretching apparatus according to a first embodiment.

The film stretching apparatus 10a has endless loops 10R and 10L having a large number of clips 20 (see FIG. 2) for gripping the film S symmetrically on both left and right sides in plan view. A film S to be stretched is fed from the entrance 1a and discharged from the exit 1b in a stretched state. That is, the film S is conveyed along the conveying direction D shown in FIG. A right endless loop 10R and a left endless loop 10L are referred to as the right endless loop and the left endless loop 10L, respectively, when viewed from the entrance 1a side. The film S is, for example, a thermoplastic resin film or the like. Also, the coordinate system XYZ shown in FIG. 1 is set for the following description. The X-axis indicates the width direction of the film S. The Y-axis indicates the direction in which the film S is transported. The Z-axis indicates a direction orthogonal to the X-axis and the Y-axis. Although the film S is drawn discontinuously in FIG. 1 to make the drawing easier to understand, the film S is actually continuous from the entrance 1a to the exit 1b.

The clip 20 is attached at positions facing each other between the inlet 1a and the outlet 1b. That is, a pair of clips 20 facing each other are arranged at both ends in the width direction (X-axis direction) of the film S to be stretched, and function as a gripping device that grips the film S. As shown in FIG. A plurality of articulated clips 20 form a clip link 30 (see FIG. 2).

The clip link 30 is guided by the reference rail 100 and circulates in a loop. The right endless loop 10R circulates clockwise, and the left endless loop 10L circulates counterclockwise. Specifically, engaged portions (not shown) provided on the clips 20 selectively engage with the drive sprockets 11 and 12, causing the clips 20 to travel along the circuit route.

As the distance between the reference rail 100 of the right endless loop 10R and the reference rail 100 of the left endless loop 10L increases, the film S is stretched in the lateral direction (X-axis direction) (section Z3 in FIG. 1). Also, when the distance between the reference rail 100 of the right endless loop 10R and the reference rail 100 of the left endless loop 10L becomes smaller, the film S shrinks in the lateral direction (X-axis direction) (section Z5 in FIG. 1).

Adjacent clips 20 are connected by a clip spacing adjustment mechanism 40a (see FIG. 2) that adjusts a clip spacing k (see FIG. 5) between the clips 20 concerned. The clip spacing adjustment mechanism 40 a sets a clip spacing k according to the positional relationship between two parallel adjustment rails 110 and 120 installed with a rail spacing p therebetween and the reference rail 100 . More specifically, the clip spacing adjustment mechanism 40a adjusts the rail spacing Wa between the adjustment rail 110 and the reference rail 100 in the direction orthogonal to the reference rail 100, and between the adjustment rail 120 and the reference rail 100, A clip interval k is set according to the rail interval Wb in the direction perpendicular to the reference rail 100 . Note that the rail intervals Wa and Wb are set based on the longitudinal draw ratio of the film S according to the position in the Y-axis direction.

For example, the rail spacing Wa between the reference rail 100 and the adjustment rail 110 gradually increases along the transport direction D of the film S in the section Z3 of FIG. At this time, the clip spacing k is gradually increased by the action of the clip spacing adjusting mechanism 40a, which will be described later. Then, the film S is stretched along the transport direction D, that is, along the machine direction. Note that the adjustment rail 110 is an example of a first interval adjustment rail in the present disclosure.

1, the rail interval Wb between the reference rail 100 and the adjustment rail 120 gradually decreases along the transport direction D of the film S. As shown in FIG. At this time, the clip spacing k is gradually reduced by the action of the clip spacing adjusting mechanism 40a, which will be described later. Then, the film S is relaxed along the transport direction D, that is, along the longitudinal direction. Note that the adjustment rail 120 is an example of a second interval adjustment rail in the present disclosure.

Thus, the film stretching apparatus 10a stretches, relaxes, or maintains the state of the film S in accordance with the sections Z1, Z2, Z3, Z4, Z5, Z6, and Z7 shown in FIG. .

In the section Z1, the film stretching device 10a grips the film S in a state in which the clip interval k is set to the initial value of the longitudinal stretching ratio and the lateral stretching ratio is set to the initial value.

Section Z2 is a preheat zone. The film stretching device 10a preheats the film S in the zone Z2. In the section Z2, the interval between the reference rail 100 of the left endless loop 10L and the reference rail 100 of the right endless loop 10R is set to correspond to the initial lateral stretching width. Also, the clip interval k maintains the state of being set to the initial value of the longitudinal draw ratio.

Section Z3 is a drawing zone. In the section Z3, the film stretching device 10a laterally stretches the film S in the X-axis direction and longitudinally stretches it in the Y-axis direction. The lateral stretching is realized by widening the distance between the reference rail 100 of the left endless loop 10L and the reference rail 100 of the right endless loop 10R toward the downstream side in the conveying direction D. In longitudinal stretching, the rail spacing Wa between the reference rail 100 and the adjustment rail 110 of the left endless loop 10L and the rail spacing Wa between the reference rail 100 and the adjustment rail 110 of the right endless loop 10R are widened toward the downstream side in the conveying direction D. It is realized by A detailed operation example of the clip 20 will be described later.

Section Z4 is a heat treatment zone. In the section Z4, the film stretching apparatus 10a maintains the lateral magnification and the longitudinal magnification at the exit state of the section Z3.

Section Z5 is a relaxation zone. In the section Z5, the film stretching device 10a laterally relaxes the film S in the X-axis direction and longitudinally relaxes it in the Y-axis direction. Lateral relaxation is achieved by narrowing the distance between the reference rail 100 of the left endless loop 10L and the reference rail 100 of the right endless loop 10R toward the downstream side in the transport direction D. In longitudinal relaxation, the rail spacing Wb between the reference rail 100 and the adjustment rail 120 of the left endless loop 10L and the rail spacing Wb between the reference rail 100 and the adjustment rail 120 of the right endless loop 10R are narrowed toward the downstream side in the transport direction D. It is realized by A detailed operation example of the clip 20 will be described later.

Section Z6 is a cooling zone. In the section Z6, the film stretching apparatus 10a maintains the lateral magnification and the longitudinal magnification at the exit state of the section Z5.

In the section Z7, the film stretching device 10a releases the film S from its grip.

[Description of schematic structure of clip]
Next, a schematic configuration of the clip 20 will be described with reference to FIGS. 2 to 4. FIG. FIG. 2 is a plan view of a clip link used in the film stretching device according to the first embodiment. FIG. 3 is a side view of the clip used in the film stretching apparatus according to the first embodiment, viewed from the upstream side in the conveying direction. FIG. 4 is a cross-sectional view taken along line AA of FIG.

FIG. 2 is a plan view looking down from the Z-axis positive side of two adjacent clips 20 that constitute the left endless loop 10L. As shown in FIG. 2, the clip 20 includes rolling units 22a that abut on both side surfaces of the upper reference rail 100a (see FIG. 3) at approximately the same height. The rolling unit 22a includes two rollers 23a that contact the side surface of the upper reference rail 100a in the positive direction of the X axis, and two rollers 24a that contact the side surface of the upper reference rail 100a in the negative direction of the X axis. . Each roller 23a, 24a provided in the rolling unit 22a moves along the upper reference rail 100a while rotating around the Z axis.

The rolling unit 22a also includes a roller 25a. The roller 25a is positioned below the upper reference rail 100a. The roller 25a prevents the clip link 30 from lifting by coming into contact with the lower side of the upper reference rail 100a when the moving clip link 30 is lifted in the Z-axis positive direction.

Thus, the clip link 30 in which the plurality of clips 20 are connected is supported on the upper reference rail 100a by the rollers 23a, 24a and the roller 25a provided in the rolling unit 22a. The upper reference rail 100a is arranged on the upper surface side of the film S along the transport direction of the film S, and guides the clip link 30. As shown in FIG.

As shown in FIG. 3, a lower reference rail 100b parallel to the upper reference rail 100a is installed at the same position in the X-axis direction below the upper reference rail 100a. A rolling unit 22b having the same structure as the rolling unit 22a is provided below the clip 20. As shown in FIG. The rolling unit 22b includes rollers 23b and 24b corresponding to the rollers 23a and 24a included in the rolling unit 22a. The rollers 23b and 24b have the same structure as the rollers 23a and 24a. Each roller 23b, 24b provided in the rolling unit 22b moves along the lower reference rail 100b while rotating around the Z axis.

The rolling unit 22a also includes a roller 25b shown in FIG. The roller 25b contacts the upper surface of the lower reference rail 100b from the upper side of the lower reference rail 100b. The roller 25b moves along the lower reference rail 100b while rotating around the X axis.

Thus, the clip link 30 in which the plurality of clips 20 are connected is supported on the lower reference rail 100b by the rollers 23b, 24b and the roller 25b provided in the rolling unit 22b. The lower reference rail 100b is arranged along the conveying direction of the film S on the lower surface side of the film S, and guides the clip link 30. As shown in FIG.

A clip interval adjusting mechanism 40a shown in FIGS. 2 and 3 is installed between the adjacent clips 20. As shown in FIGS. The clip spacing adjusting mechanism 40 a includes a clip spacing adjusting link 42 a and a clip spacing adjusting roller 44 .

The clip interval adjustment link 42a connects adjacent clips 20 to each other. The clip interval adjusting link 42a has a substantially L-shape in plan view, and is rotatably supported on the XY plane by a shaft member 45 that penetrates the clip 20 in the Z-axis direction. The shaft member 45 further supports the rollers 23a and 23b.

A shaft member 46 along the Z-axis is installed at the end of the clip interval adjusting link 42a on the reference rail 100 side. The shaft member 46 pivotally supports the adjacent clips 20 so that the clip interval k can be adjusted. Details will be described later (see FIG. 4).

The clip interval adjusting roller 44 is rotatably supported around the Z axis by a shaft member 47a along the Z axis at the end of the clip interval adjusting link 42a on the side of the adjusting rails 110, 120. As shown in FIG. The clip spacing adjusting roller 44 is fitted between the adjusting rail 110 (first spacing adjusting rail) and the adjusting rail 120 (second spacing adjusting rail) and contacts the adjusting rail 110 and the adjusting rail 120 . More specifically, the clip spacing adjustment roller 44 is arranged to adjust the clip spacing k more accurately and to allow the clip link 30 to run smoothly, with a small gap between the adjustment rail 110 and the adjustment rail. 120. Note that the clip interval adjusting roller 44 is an example of a roller in the present disclosure.

Note that the clip interval adjusting rollers 44 are installed at two locations, upper and lower, with the clip interval adjusting link 42a interposed therebetween. That is, as shown in FIG. 3, a clip interval adjusting roller 44a is installed above the clip interval adjusting link 42a, and a clip interval adjusting roller 44b is installed below the clip interval adjusting link 42a.

The clip interval adjusting rollers 44 a and 44 b move together with the clip 20 while rotating in contact with the adjusting rail 110 and the adjusting rail 120 . The clip spacing adjusting rollers 44a and 44b receive forces according to the installation positions of the adjusting rail 110 (first spacing adjusting rail) and the adjusting rail 120 (second spacing adjusting rail).

For example, when the rail spacing Wa between the reference rail 100 and the adjustment rail 110 increases along the transport direction D, the clip spacing adjustment rollers 44a and 44b are pushed out in the X-axis negative direction (direction away from the reference rail 100). receive power. As a result, the clip interval adjusting link 42a rotates clockwise around the shaft member 45. As shown in FIG. As a result, the clip interval k between adjacent clips 20 is increased. Details will be described later (see FIG. 5).

Also, when the rail interval Wb between the reference rail 100 and the adjustment rail 120 decreases along the conveying direction D, the clip interval adjustment rollers 44a and 44b are pushed out in the positive direction of the X axis (direction approaching the reference rail 100). receive power. As a result, the clip interval adjusting link 42a rotates around the shaft member 45 counterclockwise. As a result, the clip interval k between adjacent clips 20 is reduced. Details will be described later (see FIG. 5).

Next, the action of the clip interval adjusting link 42a will be described with reference to FIG. Adjacent clips 20 are connected to each other by a shaft member 46 along the Z axis so as to be rotatable around the Z axis. Specifically, the first element 50 formed by the end portion of the clip interval adjustment link 42a on the side of the reference rail 100 and the shaft member 48 that supports the rollers 23a and 23b of the adjacent clips 20 are pivotally supported. and the second element 52 are connected by a shaft member 46 so as to be rotatable about the Z axis.

With such a connection structure, when the clip interval adjustment link 42a is pushed out in the positive direction of the X axis by the adjustment rail 120, the angle formed by the first element 50 and the second element 52 in plan view changes. do. As a result, the clip interval k between adjacent clips 20 changes. Further, when the clip interval adjusting link 42a is pushed out in the X-axis negative direction by the adjusting rail 110, the angle formed by the first element 50 and the second element 52 in plan view changes. As a result, the clip interval k between adjacent clips 20 changes. Details will be described later (see FIG. 5).

[Explanation of operation of clip interval adjustment mechanism]
Next, the operation of the clip interval adjusting mechanism 40a will be described with reference to FIGS. 3, 5 and 6. FIG. FIG. 5 is a plan view showing an example of a state in which clip intervals of clip links used in the film stretching apparatus according to the first embodiment are changed. FIG. 6 is a side view of the clip viewed from the upstream side in the conveying direction in a state where the clip interval is narrowed. Further, FIG. 3 described above represents a side view of the clip seen from the upstream side in the conveying direction in a state where the clip interval is widened in FIG.

FIG. 5 shows three clips 20a, 20b, 20c that are articulated. Here, for the sake of explanation, the clip 20a and the clip 20b show a state where the clip interval k has reached the maximum value (kmax). Clip 20b and clip 20c indicate a state where clip interval k is the minimum value (kmin).

First, the operation of the clip interval adjusting mechanism 40a installed between the clip 20a and the clip 20b will be described.

In FIG. 5, the rail spacing Wa2 between the reference rail 100 (100a) and the adjustment rail 110 (110a) in the section between the clip 20a and the clip 20b is equal to that of the reference rail 100 in the section between the clip 20b and the clip 20c. (100a) and the adjustment rail 110 (110a) are set larger than the rail spacing Wa1. Therefore, when the clip link 30 moves in the transport direction D, the roller 44 (44a) is pushed out in the X-axis negative direction by the adjustment rail 110 (110a).

At this time, the clip interval adjusting link 42a connected to the roller 44 (44a) rotates clockwise around the shaft member 45. As shown in FIG. With this rotation, the angle θ1 formed by the first element 50 and the second element 52, which are supported by the shaft member 46, approaches 180° in a plan view. , the shaft member 48 of the clip 20b and the shaft member 46 connecting the clip 20a and the clip 20b change in the direction in which they are aligned linearly in plan view. As a result, the clip interval k between the clip 20a and the clip 20b is increased.

On the other hand, let us consider a case where the conveying direction D is reversed in FIG. At this time, the rail spacing Wb2 between the reference rail 100 (100a) and the adjustment rail 120 in the section between the clip 20b and the clip 20c is equal to that of the reference rail 100 (100a) in the section between the clip 20a and the clip 20b. It is set smaller than the rail interval Wb1 with the adjustment rail 120 . Therefore, when the clip link 30 moves in the direction opposite to the conveying direction D, the roller 44 (44a) is pushed out by the adjustment rail 120 in the X-axis positive direction.

At this time, the clip interval adjusting link 42a connected to the roller 44 (44a) rotates around the shaft member 45 counterclockwise. Along with this rotation, the angle θ2 formed in plan view between the first element 50 and the second element 52 supported by the shaft member 46 decreases from 180°, that is, the shaft member of the clip 20a. 45, the shaft member 48 of the clip 20b, and the shaft member 46 connecting the clip 20a and the clip 20b are bent in a plan view. As a result, the clip interval k between the clip 20a and the clip 20b is reduced.

FIG. 3 is a side view of the clip 20 showing a state where the clip interval k has reached its maximum value (kmax). As shown in FIG. 3, the roller 44a is installed above the clip interval adjusting link 42a, and the roller 44b is installed below the clip interval adjusting link 42b. Therefore, the force of the adjusting rail 110 (110a, 110b) pushing out the rollers 44 (44a, 44b) in the negative direction of the X-axis uniformly acts on the clip interval adjusting link 42a. As a result, the expansion of the clip interval k (that is, the stretching of the film S in the longitudinal direction) is ensured.

Also, FIG. 6 is a side view of the clip 20 (20b) showing a state where the clip interval k has reached the minimum value (kmin). As shown in FIG. 6, the roller 44a is installed above the clip interval adjusting link 42a, and the roller 44b is installed below the clip interval adjusting link 42b. Therefore, the force of the adjustment rail 120 pushing out the rollers 44 (44a, 44b) in the positive direction of the X axis acts evenly on the clip interval adjustment link 42a. As a result, the reduction of the clip spacing k (that is, the relaxation of the film S in the longitudinal direction) is ensured.

As described above, the film stretching apparatus 10a of the first embodiment connects the adjacent clips 20, and adjusts the adjustment rail 110 (first interval adjustment rail) and the adjustment rail 120 (second interval adjustment rail). ) has a clip spacing adjusting mechanism 40a having rollers 44 (44a, 44b) that abut against the clip. The adjustment rail 110 applies force to the roller 44 in the direction of increasing the clip spacing k. The adjustment rail 120 is provided at the same height position parallel to the adjustment rail 110 to apply a force to the roller 44 in the direction of reducing the clip spacing k. Therefore, it is possible to reliably control the clip spacing k in both the contracting direction and the expanding direction, as compared with clips for a conventional shrink tenter.

Further, according to the film stretching apparatus 10a of the first embodiment, the adjustment rail 110 (first interval adjustment rail) is arranged along the transport direction D of the film S with the adjustment rail 110, and the clip link 30 By widening the rail spacing Wa with the reference rail 100 (100a, 100b) that guides the clip spacing k, the clip spacing k is increased. Therefore, the clip interval k can be reliably controlled in the enlargement direction. This solves the conventional problem that the clip link 30 is arbitrarily pushed forward without releasing the push of the clip link 30 when the contraction force of the object to be stretched is large. be able to.

Further, according to the film stretching apparatus 10a of the first embodiment, the adjustment rail 120 (second interval adjustment rail) narrows the rail interval Wb between the adjustment rail 120 and the reference rail 100 (100a, 100b). reduces the clip interval k. Therefore, the clip interval k can be reliably controlled in the contraction direction.

Further, according to the film stretching apparatus 10a of the first embodiment, the rollers 44 (44a, 44b) are arranged at two positions symmetrical in the height direction with respect to the clip spacing adjustment mechanism 40a, respectively, the adjustment rails 110 (first spacing adjustment rail) and adjustment rail 120 (second spacing adjustment rail). Therefore, the force that the clip interval adjustment mechanism 40a receives from the film S can be received in a well-balanced manner in the vertical direction. As a result, the clip link 30 can be stably run, and the clip interval k can be reliably controlled both in the contracting direction and the expanding direction.

(Second embodiment)
Next, a film stretching apparatus 10b according to a second embodiment will be described with reference to FIG. FIG. 7 is a side view of the clip used in the film stretching apparatus according to the second embodiment, viewed from the upstream side in the conveying direction.

The film stretching device 10b includes a clip spacing adjusting mechanism 40b instead of the clip spacing adjusting mechanism 40a included in the clip 20 of the film stretching device 10a. In addition, the film stretching device 10b includes an adjustment rail 110 instead of the adjustment rails 110 (110a, 110b) provided in the film stretching device 10a.

The clip spacing adjusting mechanism 40b includes a clip spacing adjusting link 42b and clip spacing adjusting rollers 44 (44c, 44d).

The clip interval adjusting link 42b has a shape substantially equal to that of the clip interval adjusting link 42a in plan view. 3 and 7, the clip interval adjusting link 42a and the clip interval adjusting link 42b have different shapes when viewed from the side. That is, the clip spacing adjusting link 42a has a vertically symmetrical shape with respect to the center line passing through the clip spacing adjusting link 42a along the X axis, whereas the clip spacing adjusting link 42b has a vertically asymmetrical shape along the X axis. shape.

The clip spacing adjusting rollers 44 (44c, 44d) are rotatably supported around the Z axis by a shaft member 47b along the Z axis at the end of the clip spacing adjusting link 42b on the side of the adjusting rails 110, 120. . Clip spacing adjustment rollers 44c and 44d have the same diameter and thickness.

Two clip interval adjusting rollers 44 (44c, 44d) are provided above the clip interval adjusting link 42b. The clip interval adjusting rollers 44 (44c, 44d) are fitted between the adjusting rails 110 and 120, respectively.

The clip interval adjusting link 42b has the same function as the clip interval adjusting link 42a described in the first embodiment. The clip interval adjusting link 42 b expands the clip interval k of the clip 20 traveling in the transport direction D to an amount corresponding to the rail interval Wa between the adjusting rail 110 and the reference rail 100 . Further, the clip interval adjusting link 42b reduces the clip interval k of the clip 20 traveling along the conveying direction D to an amount corresponding to the rail interval Wb between the adjusting rail 120 and the reference rail 100. FIG.

Note that the clip interval adjusting link 42b shown in FIG. 7 may be installed in a state of being rotated (reversed) by 180° around the X axis. In this case, two clip interval adjusting rollers 44 (44c, 44d) are provided below the clip interval adjusting link 42b.

As described above, in the film stretching apparatus 10b of the second embodiment, the clip spacing adjusting rollers 44 (44c, 44d) included in the clip spacing adjusting mechanism 40b are positioned either above or below the clip spacing adjusting mechanism 40b. , they abut on equal height positions of the adjustment rail 110 (first adjustment rail) and the adjustment rail 120 (second adjustment rail), respectively. Therefore, the adjustment rail 110 applies force to the roller 44 in the direction of increasing the clip spacing k. Further, the adjustment rail 120 is provided in parallel with the adjustment rail 110 and at the same height position, and applies a force to the roller 44 in the direction of reducing the clip spacing k. As a result, it is possible to reliably control the clip spacing k in both the contracting direction and the expanding direction, as compared with clips for a conventional shrink tenter.

(Third Embodiment)
Next, a film stretching device 10c according to a third embodiment will be described with reference to FIG. FIG. 8 is a side view of the clip used in the film stretching apparatus according to the third embodiment, viewed from the upstream side in the conveying direction.

The film stretching device 10c includes a clip spacing adjusting mechanism 40c instead of the clip spacing adjusting mechanism 40a included in the clip 20 of the film stretching device 10a. In addition, the film stretching device 10c includes an adjustment rail 110 instead of the adjustment rails 110 (110a, 110b) provided in the film stretching device 10a.

The clip spacing adjusting mechanism 40c includes a clip spacing adjusting link 42c and a clip spacing adjusting roller 44 (44e).

The clip spacing adjusting link 42c has a shape substantially equal to that of the clip spacing adjusting link 42a in plan view. 3 and 8, the clip interval adjusting link 42a and the clip interval adjusting link 42c have different shapes when viewed from the side. That is, the clip spacing adjusting link 42a has a vertically symmetrical shape with respect to the center line passing through the clip spacing adjusting link 42a along the X axis, whereas the clip spacing adjusting link 42c has a vertically asymmetrical shape along the X axis. shape.

The clip spacing adjusting roller 44 (44e) is rotatably supported around the Z axis by a shaft member 47c along the Z axis at the end of the clip spacing adjusting link 42c on the side of the adjusting rails 110, 120. One clip interval adjusting roller 44e is provided above the clip interval adjusting link 42c. The clip interval adjusting roller 44 ( 44 e ) is fitted between the adjusting rail 110 and the adjusting rail 120 .

The clip interval adjusting link 42c has the same function as the clip interval adjusting link 42a described in the first embodiment. The clip interval adjusting link 42 c expands the clip interval k of the clip 20 traveling in the transport direction D to an amount corresponding to the rail interval Wa between the adjusting rail 110 and the reference rail 100 . Further, the clip interval adjusting link 42b reduces the clip interval k of the clip 20 traveling along the conveying direction D to an amount corresponding to the rail interval Wb between the adjusting rail 120 and the reference rail 100. FIG.

Note that the clip interval adjusting link 42c shown in FIG. 8 may be installed in a state of being rotated (reversed) by 180° around the X axis. In this case, the clip spacing adjusting roller 44 (44e) is provided below the clip spacing adjusting link 42c.

As described above, in the film stretching apparatus 10c of the third embodiment, the clip spacing adjusting roller 44 (44e) provided in the clip spacing adjusting mechanism 40c is positioned either above or below the clip spacing adjusting mechanism 40c. , at the same height position of the adjustment rail 110 (first adjustment rail) and the adjustment rail 120 (second adjustment rail). Therefore, the adjustment rail 110 applies force to the roller 44 in the direction of increasing the clip spacing k. Further, the adjustment rail 120 is provided in parallel with the adjustment rail 110 and at the same height position, and applies a force to the roller 44 in the direction of reducing the clip spacing k. As a result, it is possible to reliably control the clip spacing k in both the contracting direction and the expanding direction, as compared with clips for a conventional shrink tenter.

(Fourth embodiment)
Next, a film stretching apparatus 10d according to a fourth embodiment will be described with reference to FIGS. 9 and 10. FIG. FIG. 9 is a plan view of a clip link used in the film stretching device according to the fourth embodiment. FIG. 10 is a side view of the clip used in the film stretching apparatus according to the fourth embodiment, viewed from the upstream side in the conveying direction.

The film stretching device 10d includes a clip spacing adjusting mechanism 40d instead of the clip spacing adjusting mechanism 40a included in the clip 20 of the film stretching device 10a. In addition, the film stretching device 10d includes an adjustment rail 130 instead of the adjustment rails 110 and 120 provided in the film stretching device 10a.

The clip spacing adjusting mechanism 40d includes a clip spacing adjusting link 42d and clip spacing adjusting rollers 44f and 44g.

The clip spacing adjusting link 42d extends from the clip spacing adjusting link 42a on the side of the adjusting rail 130 in plan view, and has two clip spacing adjusting rollers 44f and 44g at the tip of the clip spacing adjusting link 42d. is different.

The clip spacing adjustment roller 44f is installed at the tip of the clip spacing adjustment link 42d on the side of the adjustment rail 130 so as to contact the side surface of the adjustment rail 130 on the negative side of the X axis. The clip interval adjusting roller 44g is installed at the tip of the clip interval adjusting link 42d on the adjusting rail 130 side so as to contact the side surface of the adjusting rail 130 in the positive direction of the X axis. The clip interval adjusting roller 44f is rotatably supported around the Z-axis by a shaft member 49a along the Z-axis. In addition, the clip interval adjusting roller 44g is rotatably supported around the Z-axis by a shaft member 49b along the Z-axis. The clip interval adjusting rollers 44f and 44g abut on both sides of the adjusting rail 130 at equal height positions.

When the clip link 30 moves in the conveying direction D, the clip spacing adjustment link 42d receives a force that pushes it in a direction corresponding to the rail spacing Wc between the adjustment rail 130 and the reference rail 100 .

That is, when the rail interval Wc increases along the transport direction D, the clip interval adjustment roller 44f receives a force that pushes it in the X-axis negative direction. At this time, the clip interval adjusting link 42d rotates clockwise around the shaft member 45. As shown in FIG. As a result, the clip interval k between adjacent clips 20 is increased.

Further, when the rail interval Wc decreases along the transport direction D, the clip interval adjusting roller 44g receives a force that pushes it in the positive direction of the X axis. At this time, the clip interval adjusting link 42d rotates around the shaft member 45 counterclockwise. As a result, the clip interval k between adjacent clips 20 is reduced.

In the first to third embodiments, two adjustment rails 110 and 120 are installed, and the clip interval k is increased in accordance with the rail interval Wa between the reference rail 100 and the adjustment rail 110. It was adjusted. In addition, the clip spacing k is adjusted in the direction of reduction according to the rail spacing Wb between the reference rail 100 and the adjustment rail 120 . In contrast, in the fourth embodiment, the two adjustment rails 110 and 120 are replaced with one adjustment rail 130, and the clip interval k is adjusted according to the rail interval Wc between the reference rail 100 and the adjustment rail 130. Adjust to grow and shrink.

As shown in FIG. 9, the clip spacing adjusting roller 44f and the clip spacing adjusting roller 44g contact the adjusting rail 130 at different Y-axis direction positions along the transport direction D. As shown in FIG. As a result, both the force of the adjusting rail 130 pushing the clip spacing adjusting roller 44f in the negative direction of the X axis and the force of the adjusting rail 130 pushing the clip spacing adjusting roller 44g in the positive direction of the X axis act as the clip spacing adjusting link. 42d. Therefore, the clip spacing adjusting mechanism 40d reliably controls both the increasing direction and the decreasing direction of the clip spacing k.

As described above, the film stretching apparatus 10d of the fourth embodiment includes the adjusting rail 110 (first gap adjusting rail) and the adjusting rail 120 (second gap adjusting rail) described in the first embodiment. is formed by one adjustment rail 130 . Clip interval adjusting rollers 44f and 44g (rollers) provided in the clip interval adjusting mechanism 40d abut on both sides of the adjusting rail 130 at equal height positions. Therefore, one adjusting rail 130 and the clip spacing adjusting rollers 44f and 44g (rollers) that receive the force pushed out from the adjusting rail 130 in the positive direction of the X axis or the negative direction of the X axis are used to expand the clip spacing k. and can be reliably controlled both in the direction of contraction.

10a, 10b, 10c, 10d... Film stretching device, 10L... Left endless loop, 10R... Right endless loop, 20, 20a, 20b, 20c... Clip, 22a, 22b... Rolling unit, 23a, 23b, 24a, 24b, 25a, 25b... Rollers 30... Clip links 40a, 40b, 40c, 40d... Clip interval adjusting mechanisms 42a, 42b, 42c, 42d... Clip interval adjusting links 44, 44a, 44b, 44c, 44d, 44e, 44f , 44g... Clip interval adjusting roller (roller) 45, 46, 47a, 47b, 47c, 48, 49a, 49b... Shaft member 50... First element 52... Second element 100... Reference rail 100a Upper side reference rail 100b Lower side reference rail 110 Adjustment rail (first interval adjustment rail) 120 Adjustment rail (second interval adjustment rail) 130 Adjustment rail D Conveying direction k Clip interval, p... Rail interval, S... Film, Wa, Wa1, Wa2, Wb, Wb1, Wb2, Wc... Rail interval, Z1, Z2, Z3, Z4, Z5, Z6, Z7... Section, θ1, θ2... Angle

Claims (7)

A film stretching device that stretches the film while conveying it by holding the ends of the film in the width direction with a plurality of clips and running a clip link formed by the plurality of clips,
a reference rail arranged along the transport direction of the film for guiding the clip link;
a first spacing adjustment rail provided with a spacing corresponding to the clip spacing of the adjacent clips between the reference rail;
a second spacing adjustment rail provided parallel to the first spacing adjustment rail ;
a first roller that supports the clip and rotates around a first shaft member while contacting the reference rail;
a second roller rotating around a second shaft member parallel to the first shaft member while contacting the first gap adjustment rail and the second gap adjustment rail;
a third shaft member installed parallel to the first shaft member at a position sandwiched between the two first rollers respectively supporting the adjacent clips;
integrally supporting the second shaft member, one of the first shaft members that respectively pivotally support the two first rollers that support the adjacent clips, and the third shaft member a link member;
a connection member that connects the other of the first shaft members and the third shaft member so that the interval between the adjacent first rollers can be changed;
By changing the angle of the link member according to the distance between the reference rail and the first distance adjustment rail or the distance between the reference rail and the second distance adjustment rail, the link member and a clip interval adjusting mechanism that adjusts the clip interval between the clips respectively supported by the adjacent first rollers connected by the connecting member . The first spacing adjustment rail expands the clip spacing by increasing the rail spacing between the first spacing adjustment rail and the reference rail.
The film stretching apparatus according to claim 1. The second spacing adjustment rail reduces the clip spacing by narrowing the rail spacing between the second spacing adjustment rail and the reference rail.
The film stretching apparatus according to claim 1. The second roller abuts on equal height positions of the first gap adjusting rail and the second gap adjusting rail at two locations symmetrical in the height direction with respect to the clip gap adjusting mechanism.
The film stretching apparatus according to any one of claims 1 to 3. The second rollers are positioned at equal heights of the first gap adjusting rail and the second gap adjusting rail at two locations on either the upper side or the lower side of the clip gap adjusting mechanism. abut,
The film stretching apparatus according to any one of claims 1 to 3. The second roller abuts on the same height position of the first spacing adjustment rail and the second spacing adjustment rail at one point on either the upper side or the lower side of the clip spacing adjustment mechanism. ,
The film stretching apparatus according to any one of claims 1 to 3. The first spacing adjustment rail and the second spacing adjustment rail are formed of a single rail,
The second rollers included in the clip spacing adjustment mechanism are in contact with equal height positions on both side surfaces of the one rail.
The film stretching apparatus according to claim 1.

Images