WO2021215174A1 - Stretching device and clip number adjustment method - Google Patents

Abstract

This stretching device 100 comprises: a pair of rail devices 10L, 10R that each define an endless circulation path and that are disposed on the left and right sides of a film; a plurality of clip units CU that travel along the circulation paths of the pair of rail devices 10L, 10R and that grip the film; a linking mechanism 50 that links adjacent clip units CU on the circulation paths; a drive mechanism 60 that causes the clip units CU to travel along the circulation paths; an adjustment mechanism 70 that adjusts the pitch in the vertical direction and the pitch in the horizontal direction of the clip units CU; and a controller 80 that controls the operation of the drive mechanism 60 and the adjustment mechanism 70, wherein the controller 80 controls the rotation of outlet-side sprockets 62L, 62R in accordance with the load acting on the rail devices 10L, 10R from the clip units CU.

Description

Stretching device and clip number adjustment method

The present invention relates to a stretching device and a method for adjusting the number of clips.

Japanese Unexamined Patent Publication No. 2012-12159 discloses a biaxial simultaneous stretching device including an endless link device provided with a plurality of gripping devices for gripping the ends of the sheet-shaped object on both sides of the sheet-shaped object.

In the extending section, this endless link device is guided by two guide rails arranged in parallel in the divergent direction in the traveling direction, and is extended in the TD direction (longitudinal direction of the divergent portion) and MD. Grasp pitch gradually expands from P1 to P2 in the direction (traveling direction). As a result, the sheet-like material is simultaneously stretched in two vertical and horizontal directions. The endless link device is driven by the outlet sprocket and is configured to return to the inlet sprocket.

In the stretching device described in Japanese Patent Application Laid-Open No. 2012-12159, the endless link device is guided to move along the guide rail by a plurality of rollers. Further, the endless link device is composed of a plurality of link mechanisms, and the pitch of the gripping device (clip unit) in the MD direction is changed by changing the distance between the two guide rails, and the film (sheet-like object) is MD. Stretched in the direction.

In such a stretching device, it is required to appropriately adjust the number of clip units in the stretching region where the film is stretched. For example, when the number of clip units in the stretching region is less than the appropriate number, a force in the direction of widening the pitch of the clip units acts on the link mechanism that connects the clip units. By this force, the roller provided in the clip unit is pressed in one direction against the guide rail. If the load acting on the guide rail from the roller becomes excessive, the rail device and the clip unit may be deformed. In order to avoid such a situation, it is necessary to appropriately adjust the number of clip units in the stretched region.

The number of clip units in the extension region is adjusted by adjusting the operation of the electric motor that drives the outlet side sprocket. Conventionally, the operator manually adjusts the operation of the electric motor while checking the torque value of the electric motor, and there is a problem that the adjustment takes a lot of time.

An object of the present invention is to provide a stretching device capable of easily adjusting the number of clips.

According to an aspect of the present invention, the stretching device that stretches the conveyed film vertically and horizontally travels on the rail device that defines an endless circulation path and is arranged on the left and right sides of the film, and the circulation path of the rail device. A plurality of clip units that grip the film, a link mechanism that connects adjacent clip units on the circulation path, a drive mechanism that runs the clip units along the circulation path, and a vertical pitch and horizontal direction of the clip units. The clip unit is provided with an adjustment mechanism for adjusting the pitch, a controller for controlling the operation of the drive mechanism and the adjustment mechanism, and a controller for acquiring load data representing the load acting on the rail device from the clip unit. It has a roller part that engages and guides the movement of the clip unit along the circulation path, and the drive mechanism is provided on both the left and right sides of the film on the inlet side where the film is supplied, and the sprockets on the inlet side that engage with the clip unit. , The outlet side sprocket provided on both the left and right sides of the film on the outlet side for delivering the stretched film and engaging with the clip unit, the first drive unit for rotationally driving the outlet sprocket, and the second drive for rotationally driving the inlet sprocket. The controller has a unit and controls the operation of at least one of the first drive unit and the second drive unit according to the load acting on the rail device from the clip unit.

FIG. 1 is a plan view showing the overall configuration of the stretching device according to the embodiment of the present invention. FIG. 2 is an enlarged plan view showing a link mechanism of the stretching device according to the embodiment of the present invention. FIG. 3 is a schematic view showing a rail unit of a stretching device according to an embodiment of the present invention. FIG. 4 is a side view of the clip unit of the stretching device according to the embodiment of the present invention. FIG. 5 is a schematic view showing a rail unit of the stretching device according to the embodiment of the present invention, and is a diagram showing a state in which the number of clips is too small. FIG. 6 is a schematic view showing a rail unit of the stretching device according to the embodiment of the present invention, and is a diagram showing a state in which the number of clips is excessive. FIG. 7 is a flowchart showing a method of adjusting the pitch by the stretching device according to the embodiment of the present invention. FIG. 8 is a flowchart showing a method of adjusting the number of clips by the stretching device according to the embodiment of the present invention.

Hereinafter, the stretching device 100 according to the embodiment of the present invention will be described with reference to the drawings. In each drawing, the scale of each configuration is appropriately changed for convenience of explanation, and the scale is not necessarily exactly shown. Further, with respect to a plurality of the same configurations, only a part thereof may be coded, and the other parts may be omitted.

First, the configuration of the stretching device 100 will be described with reference to FIGS. 1 to 6.

The stretching device 100 conveys the film to be stretched (not shown) in one direction from the inlet side (left side in FIG. 1) to the outlet side (right side in FIG. 1), and in the vertical direction along the conveying direction. It is a so-called simultaneous biaxial stretching device that simultaneously stretches (hereinafter, also referred to as "MD direction") and a lateral direction perpendicular to the MD direction (hereinafter, also referred to as "TD direction"). In the following description, the "right side" refers to the right side (lower side in the middle of FIG. 1) when viewed from the entrance side to the exit side, and the "left side" refers to the left side (upper side in the middle of FIG. 1) when viewed from the entrance side to the exit side. ). Further, in the following description, the vertical direction of the paper surface of FIG. 1 is also appropriately referred to as "up and down".

As shown in FIGS. 1 and 2, in the stretching device 100, a pair of rail devices 10L and 10R and a pair of rail devices 10L and 10R that define an endless circulation path and are arranged on the left and right sides of the film and a circulation path of the pair of rail devices 10L and 10R. A link mechanism 50 that connects a plurality of clip unit CUs that travel on the circulation path and grip the film, and a link mechanism 50 that connects adjacent clip unit CUs on the circulation path, a drive mechanism 60 that runs the clip unit CU along the circulation path, and a clip unit CU. It is provided with an adjusting mechanism 70 for adjusting the vertical pitch and the horizontal pitch of the above, and a controller 80 for controlling the operation of the driving mechanism 60 and the adjusting mechanism 70.

In the stretching device 100, the region where the left and right rail devices 10L and 10R face each other is configured as the film transport area TA. Further, in the film transport area TA, the preheating zone Za, the stretching zone Zb, and the heat treatment zone Zc are arranged (allocated) in this order from the inlet side to the outlet side. The film transport area TA is covered by a heating furnace (not shown), and the temperature is controlled for each zone. The specific configuration of each zone will be described later.

The pair of rail devices 10L and 10R are composed of a pair of reference rails 11 and a pitch setting rail 12 that define a circulation path for circulating the clip unit CU, respectively. In the pair of rail devices 10L and 10R, the pitch setting rails 12 are arranged in a loop on the inner side of the reference rail 11.

FIG. 3 is an enlarged schematic view of part A in FIG. As shown in FIG. 3, the reference rail 11 and the pitch setting rail 12 arranged in a loop form include a plurality of rail units 15 that are rotatably connected and an intermediate rail portion 16 that complements adjacent rail units 15. , Formed by. That is, each end of the rail unit 15 is rotatably connected to the intermediate rail portion 16. By rotatably connecting the adjacent rail units 15 to each other via the intermediate rail portion 16 in this way, the arrangement of the plurality of rail units 15 can be changed to form a desired circulation path. can.

The larger the distance between the pitch setting rail 12 and the reference rail 11, the smaller the MD pitch of the clip unit CU. In the preheating zone Za, the separation distance between the reference rail 11 and the pitch setting rail 12 is uniformly the maximum value (that is, the MD pitch is the minimum value) over the entire area.

In the extension zone Zb, the separation distance between the reference rail 11 and the pitch setting rail 12 is the maximum value at the extension start end (connection end with the preheating zone Za), and gradually becomes shorter toward the extension end end side. It is the minimum value at the end of stretching. That is, the stretching zone Zb is configured such that the MD pitch increases from the preheating zone Za side toward the heat treatment zone Zc.

In the heat treatment zone Zc, the separation distance between the reference rail 11 and the pitch setting rail 12 is uniformly the minimum value over the entire area.

The plurality of clip units CU are guided by the reference rails 11 of the pair of rail devices 10L and 10R, respectively, and move in a loop. The clip unit CU circulates in the clockwise direction in FIG. 1 on the right rail device 10R, and circulates counterclockwise on the left rail device 10L. In the pair of rail devices 10L and 10R, the same number of clip units CUs circulate around each other.

The clip unit CU mainly has a clip 20 for holding the film and a clip holding portion 30 for holding the clip 20, as shown in FIG.

The clip 20 can be rotated to the clip body 21 by a clip body 21 having a concave yoke shape formed in a substantially U shape, a lower fixed clip member 22 fixedly attached to the clip body 21, and a pin 23. The movable lever 24 is attached to the movable lever 24, and the upper movable clip member 26 is swingably attached to the lower end of the movable lever 24 by a pin 25. The clip 20 is gripped by the lower fixed clip member 22 and the upper movable clip member 26 by sandwiching the side edge of the film.

The clip holding unit 30 individually holds the clips 20, and there are as many clips as the number of the clips 20. The clip holding portion 30 is formed in a rigid frame structure having a closed cross section by the upper beam 35, the lower beam 36, the front wall 37, and the rear wall 38. Traveling wheels 33 and 34 are rotatably provided at both ends (front wall 37 and rear wall 38) of the clip holding portion 30 by shafts 31 and 32, respectively. The traveling wheels 33 and 34 roll on the horizontal traveling road surfaces 111 and 112 formed on the rail base 110. The traveling road surfaces 111 and 112 are parallel to the reference rail 11 of the rail devices 10L and 10R over the entire area.

A long hole (long hole) 39 is formed on the other end side (rear side) of the upper beam 35 and the lower beam 36 of each clip holding portion 30. Sliders 40 are slidably engaged with the upper and lower elongated holes 39 in the longitudinal direction of the elongated holes 39, respectively.

A single first shaft member 51 is vertically provided in the vicinity of one end (clip side) of each clip holding portion 30 so as to penetrate the upper beam 35 and the lower beam 36. A second shaft member 52 is provided vertically penetrating the upper and lower sliders 40 of each clip holding portion 30.

As shown in FIG. 2, the plurality of clip unit CUs are endlessly connected to the adjacent clip unit CUs on the circulation path by the link mechanism 50. The link mechanism 50 is composed of a first link member 53 and a second link member 54.

One end of the first link member 53 is pivotally connected to the first shaft member 51 of the clip holding portion 30, and the other end is adjacent to the clip holding portion 30 (in the present embodiment, the clip holding portion adjacent to the upstream side of the circulation). It is pivotally connected to the second shaft member 52 of 30).

One end of the second link member 54 is pivotally connected to the first shaft member 51 of the clip holding portion 30, and the other end is pivotally driven by the pivot shaft 55 to an intermediate portion between one end and the other end of the first link member 53. Be connected.

The more the slider 40 is moved to the other end side (anti-clip side) of the clip holding portion 30 by the link mechanism 50 composed of the first link member 53 and the second link member 54, in other words, the first link member. The smaller the angle formed by the 53 and the second link member 54 and the closed the link mechanism 50, the smaller the pitch (MD pitch) between the clip holding portions 30. On the contrary, as shown in FIG. 2, the more the slider 40 moves to one end side (clip side) of the clip holding portion 30, in other words, the more the first link member 53 and the second link member 54 move. The larger the angle formed and the more the link mechanism 50 is opened, the larger the pitch between the clip holding portions 30.

As shown in FIG. 4, the clip unit CU has a guide roller 56 as a first roller (roller portion) rotatably provided at the lower end of the first shaft member 51, and is rotatable at the lower end of the second shaft member 52. It has a pitch setting roller 57 as a second roller (roller portion) provided.

The guide roller 56 is provided on the rail base 110 and is engaged with the concave groove 11a of the reference rail 11 that defines the circulation path of the clip 20. The pitch setting roller 57 is provided on the rail base 110 and engages with the concave groove 12a of the pitch setting rail 12 that defines the circulation path of the clip 20. Further, a drive roller 58 is rotatably provided at the upper end of the first shaft member 51.

As shown in FIG. 1, the drive mechanism 60 includes a pair of inlet- side sprockets 61L and 61R provided on the inlet side for supplying the film and a pair of outlet- side sprockets 62L and 62R provided on the outlet side for delivering the stretched film. It has a first drive unit 64 that rotationally drives the outlet- side sprockets 62L and 62R, and a second drive unit 65 that rotationally drives the inlet- side sprockets 61L and 61R.

The inlet side sprockets 61L and 61R and the outlet side sprockets 62L and 62R are selectively engaged with the drive rollers 58 of the clip holding portions 30, respectively, and are rotationally driven by the first drive unit 64 and the second drive unit 65, respectively. A force is applied to the clip holding portion 30 to allow the clip holding portion 30 to travel along the patrol route. The inlet side sprockets 61L and 61R and the outlet side sprockets 62L and 62R are formed in the same shape. The inlet side sprockets 61L and 61R and the outlet side sprockets 62L and 62R may have different shapes.

The first drive unit 64 includes a first drive motor 64L that rotationally drives the left outlet side sprocket 62L and a second drive motor 64R that rotationally drives the right outlet side sprocket 62R. The first drive motor 64L and the second drive motor 64R are each composed of a servomotor. As described above, the left and right outlet side sprockets 62L and 62R are configured to be independently driveable by different electric motors.

The second drive unit 65 is composed of a third drive motor (hereinafter, also referred to as "third drive motor 65") that rotationally drives a pair of inlet- side sprockets 61L and 61R. The third drive motor 65 is a servo motor. The rotation of the third drive motor 65 is transmitted to each of the pair of inlet- side sprockets 61L and 61R by a transmission mechanism (not shown). In this way, the pair of inlet- side sprockets 61L and 61R are driven by a common electric motor. The rotation of the third drive motor 65 is transmitted to the left and right inlet- side sprockets 61L and 61R by transmission mechanisms so that the rotation directions are opposite to each other.

The adjustment mechanism 70 includes a first adjustment mechanism 71 that adjusts the lateral distance between the left and right rail units 15, and a second adjustment mechanism 75 that adjusts the distance between the reference rail 11 and the pitch setting rail 12 in each rail unit 15. And have.

As shown in FIG. 3, the first adjusting mechanism 71 is provided for each intermediate rail portion 16 and advances and retreats the intermediate rail portion 16 in the lateral direction. The first adjusting mechanism 71 includes a first adjusting motor 72 which is a servomotor, and a screw mechanism 73 in which the slave moves linearly by the rotation of the first adjusting motor 72.

The second adjusting mechanism 75 is provided for each rail unit 15. The second adjusting mechanism 75 is composed of a pair of linear motion mechanisms. The linear motion mechanism includes a second adjustment motor 76, which is a servomotor, and a screw mechanism 77, in which the slave moves linearly by the rotation of the second adjustment motor 76. The pair of linear motion mechanisms are attached to both ends of the rail unit 15, respectively.

The second adjustment motor 76 adjusts the distance between the reference rail 11 and the pitch setting rail 12 by rotating the screw mechanism 77 to move the pitch setting rail 12 forward and backward with respect to the reference rail 11. When the second adjusting motor 76 rotates forward, the pitch setting rail 12 moves closer to the reference rail 11, and when it rotates in the reverse direction, the pitch setting rail 12 moves away from the reference rail 11. The pitch setting rail 12 is tilted with respect to the reference rail 11 by making the rotation positions of the second adjusting motors 76 different from each other in the pair of linear motion mechanisms. Therefore, in a certain rail unit 15, the distance between the reference rail 11 and the pitch setting rail 12 is not constant but changes, whereby the amount of extension in the MD direction is adjusted.

The second adjustment motor 76 is provided with a torque sensor 78 as a detection unit that detects the rotational torque of the second adjustment motor 76. The detection result of the torque sensor 78 is input to the controller 80 (see FIG. 1). The torque value of the second adjusting motor 76 is load data representing the load acting on the rail devices 10L and 10R from the clip unit CU.

Further, as shown in FIG. 1, the outlet portion of the stretching device 100 serves as a number measuring unit for measuring the number of clips 20 in the film transport area TA (hereinafter, also simply referred to as “the number of clips”). A counting sensor 81 is provided. The measurement result of the counting sensor 81 is input to the controller 80, and the number of clips is calculated from the moving speed of the clip unit CU and the measurement result of the counting sensor 81. In other words, the number of clips means the number of clips 20 (clip unit CU) per left and right side that actually grips the film when the film is stretched. From yet another point of view, the number of clips is the number of clips 20 between the inlet and outlet of the stretching device 100, which is the outward path portion from the inlet side sprockets 61L and 61R to the outlet side sprockets 62L and 62R. Means.

The controller 80 is composed of a microcomputer equipped with a CPU (central processing unit), ROM (read-only memory), RAM (random access memory), and an I / O interface (input / output interface). The RAM stores data in the processing of the CPU, the ROM stores the control program of the CPU in advance, and the I / O interface is used for input / output of information with the connected device. The controller 80 is programmed so as to be able to execute at least the processing necessary for executing the control according to the present embodiment and the modification. The controller 80 may be configured as one device, or may be divided into a plurality of devices, and each control may be distributed and processed by the plurality of devices.

The controller 80 controls the operation of each configuration of the stretching device 100 so that the film stretching method and the pitch adjusting method described below can be executed.

Hereinafter, the operation of the stretching device 100 will be described.

First, a method of stretching a film by the stretching device 100 will be described.

The left outlet side sprocket 62L is rotationally driven counterclockwise by the first drive motor 64L, and the right outlet side sprocket 62R is rotationally driven clockwise by the second drive motor 64R. Further, the third drive motor 65 rotationally drives the right inlet side sprocket 61R in the clockwise direction and the left side inlet side sprocket 61L in the counterclockwise direction. The left and right outlet- side sprockets 62L and 62R and the inlet- side sprockets 61L and 61R are rotationally driven at the same rotational speed. By engaging the drive roller 58 with these sprockets, a running force is applied to the clip holding portion 30. As a result, the clip unit CU circulates in the clockwise path on the right side and circulates in the counterclockwise direction on the left side.

More specifically, the outlet side sprockets 62L, 62R and the inlet side sprockets 61L, 61R are arranged so that the rotation speeds of the left and right outlet side sprockets 62L, 62R are matched with the rotation speeds of the inlet side sprockets 61L, 61R. Synchronized control. That is, when the rotation speeds of the inlet side sprockets 61L and 61R are changed, the speeds of the outlet side sprockets 62L and 62R are also changed accordingly. The transport speed of the film is controlled mainly by changing the speeds of the inlet- side sprockets 61L and 61R. As described above, since the stretching device 100 has a configuration in which the inlet- side sprockets 61L and 61R are controlled to adjust the film transport speed, the upstream equipment (for example, the film manufacturing device) and the film that supply the film to the stretching device 100. It becomes easy to match with the transport speed of.

Note that the synchronous control of the outlet side sprockets 62L and 62R and the inlet side sprockets 61L and 61R is only that the speeds of the outlet side sprockets 62L and 62R and the inlet side sprockets 61L and 61R actually match. Does not mean. That is, the synchronous control in the present embodiment means controlling to match the speeds of the outlet side sprockets 62L and 62R and the inlet side sprockets 61L and 61R, and for reasons such as a difference in the shape of the sprockets, Actually, it also includes the state where the speed is deviated. Further, the outlet side sprockets 62L and 62R and the inlet side sprockets 61L and 61R may not be synchronously controlled so that the speeds match.

At the entrance where the film is taken in, both edges of the film are gripped by the clip unit CU that travels on the left and right patrol paths. Then, the gripped film enters the preheating zone Za of the film transport area TA by the movement of the clip holding portion 30 guided by the reference rail 11. The left and right clip unit CUs grip the film so that the corresponding clip unit CUs are adjacent to each other in the left-right direction. That is, the operation of the left and right clip unit CUs is controlled so as not to be displaced in the vertical direction and alternately grip the film.

In the preheating zone Za, the separation distance (that is, TD pitch) of the left and right circulation paths is set to correspond to the initial width of the film, and the left and right circulation paths are arranged parallel to each other over the entire area. Further, the distance between the pitch setting rail 12 and the reference rail 11 is also set to be uniformly the maximum value (MD pitch is the minimum value) over the entire area. Therefore, in the preheating zone Za, neither the horizontal stretching nor the vertical stretching of the film is performed, and only the treatment of preheating the film to a stretchable temperature is performed.

The film enters the stretching zone Zb after passing through the preheating zone Za. In the stretching zone Zb, the separation distance between the left and right circulation paths is gradually increased from the side of the preheating zone Za toward the heat treatment zone Zc. That is, in the extension zone Zb, the left and right circulation paths are provided in a divergent shape in which the interval increases from the inlet side to the outlet side. Therefore, in the stretching zone Zb, the lateral distance (TD pitch) between the clip holding portions 30 gradually increases. Further, in the extension zone Zb, the separation distance between the pitch setting rail 12 and the reference rail 11 gradually becomes shorter from the side of the preheating zone Za toward the heat treatment zone Zc. Therefore, when the clip unit CU travels in the extension zone Zb, the pitch setting roller 57 of the clip unit CU is guided by the pitch setting rail 12 and moves toward the reference rail 11, and as a result, the slider 40 moves toward the clip holding portion 30. Move to one end side (clip side) of. Therefore, the vertical distance (MD pitch) between the clip holding portions 30 gradually increases. Therefore, in the stretching zone Zb, the film is stretched in the MD direction (longitudinal stretching) at the same time as stretching in the TD direction (transverse stretching).

The film that has passed through the stretching zone Zb and has been biaxially stretched at the same time for lateral stretching and longitudinal stretching subsequently enters the heat treatment zone Zc. In the heat treatment zone Zc, the distance between the left and right circulation paths is set to correspond to the width of the stretched film, and the left and right circulation paths are arranged parallel to each other over the entire area. The separation distance is also uniformly the minimum value (the MD pitch is the maximum value) over the entire area. Therefore, in the heat treatment zone Zc, neither the lateral stretching nor the longitudinal stretching of the film is performed, and only the heat treatment such as temperature adjustment is performed.

At the exit at the end of the heat treatment zone Zc, the grip of the film by the left and right clips 20 is released, and the film goes straight. The clip holding portion 30 is guided by the reference rail 11 and circulates in a loop.

As described above, the film supplied from the inlet side is simultaneously stretched in two vertical and horizontal directions and sent out from the outlet side.

Next, the method of adjusting the TD pitch and the MD pitch will be described.

In the stretching device 100, the stretching amount in the horizontal direction and the stretching amount in the vertical direction can be changed by adjusting the TD pitch and the MD pitch.

To adjust the TD pitch, each intermediate rail portion 16 in the extension zone Zb is moved by the first adjustment mechanism 71 to change the distance between the left and right rail units 15. Further, in order to adjust the MD pitch, the distance between the reference rail 11 and the pitch setting rail 12 is changed by the second adjusting mechanism 75 of the rail unit 15 in the extension zone Zb. As a result, the distance between the pitch setting roller 57 guided by the pitch setting rail 12 and the reference rail 11 guided by the reference rail 11 is changed, the slider 40 (see FIG. 4) is moved, and the MD pitch is changed. NS.

Here, in the stretching device 100, the appropriate number of clips differs depending on the TD pitch and MD pitch of the clip unit CU. When there is a difference between the actual number of clips and the appropriate number of clips, a load acts on the rail unit 15 from the clip unit CU.

Specifically, when the number of clips is appropriate for the set TD pitch and MD pitch (actual number of clips = appropriate number of clips), the pitch setting roller 57 of the clip unit CU is a rail unit. It does not contact the pitch setting rail 12 of 15, or even if it does, it contacts with a relatively small force.

FIG. 5 shows the case where the number of clips is less than the appropriate number, and FIG. 6 shows the case where the number of clips is larger than the appropriate number. Note that, in FIGS. 5 and 6, the link mechanism 50 and the like are shown in a simplified manner.

As shown in FIG. 5, when the number of clips is less than the appropriate number, the clip units try to realize the set pitch in the TD direction and the MD direction by the small number of clip unit CUs. A force acts on the CU in the direction of increasing the pitch in the MD direction. Therefore, when the number of clips is too small, as shown by the arrow in FIG. 5, the pitch setting roller 57 approaches the film in the left-right direction toward the film side (left-right center side of the stretching device 100). Pressed against 12.

On the contrary, when the number of clips is larger than the appropriate number, a force acts on the clip unit CU in the direction of reducing the pitch in the MD direction. Therefore, when the number of clips is excessive, as shown by the arrow in FIG. 6, the pitch setting roller 57 is pressed against the pitch setting rail 12 toward the opposite side of the film in the left-right direction so as to be separated from the film.

When the pitch setting roller 57 is pressed against the pitch setting rail 12 in this way, the pitch setting roller 57 and the pitch setting rail 12 may be deformed, and the accuracy of pitch adjustment of the clip unit CU may decrease. In particular, when the pitch setting rail 12 is moved while the pitch setting roller 57 is pressed against the pitch setting rail 12 to adjust the MD pitch, the second adjustment mechanism 75 having the second adjustment motor 76 and the screw mechanism 77 On the other hand, a large load is generated and the machine life may be shortened.

Therefore, in the stretching device 100, in order to avoid such a situation, the pitches in the TD direction and the MD direction are adjusted while adjusting the number of clips to be appropriate. In the stretching device 100, the drive mechanism 60 and the adjustment mechanism 70 are controlled so that the left and right sides are synchronized with each other in adjusting the pitch and adjusting the number of clips.

Specifically, in the stretching device 100, the load acting on the rail devices 10L and 10R from the clip unit CU is detected by the torque value T of the second adjusting motor 76 of the second adjusting mechanism 75, and the clip is clipped according to the torque value T. Adjust the number. The number of clips can be adjusted by temporarily increasing or decreasing the rotation speed of the outlet side sprockets 62L and 62R. In other words, the number of clips is adjusted by changing the phase of the outlet side sprockets 62L, 62R with respect to the inlet side sprockets 61L, 61R rotating at the same speed.

More specifically, in the stretching device 100, the torque value T is compared with the predetermined first threshold value and the second threshold value to determine whether the number of clips is too small or too large, so that the number of clips is appropriate. It controls the operation of the outlet side sprockets 62L and 62R. In the stretching device 100, even if only the torque value T of the second adjustment motor 76 of any of the left and right second adjustment mechanisms 75 exceeds the first threshold value or falls below the second threshold value, the left and right sides The operation of both the outlet side sprockets 62L and 62R is controlled in the same manner.

The torque value T of the second adjustment motor 76 is acquired as a value having positive and negative values. In the present embodiment, the torque in the direction in which the second adjusting motor 76 rotates in the reverse direction (in other words, the pitch setting rail 12 is separated from the reference rail 11) is set as a positive torque value T.

The first threshold is a threshold having a positive value, and the second threshold is a threshold having a negative value. The first threshold value is a threshold value for determining whether or not the number of clips is too small, and the second threshold value is a threshold value for determining whether or not the number of clips is excessive. In the following, the first threshold value is “+ T1” and the second threshold value is “−T2”.

The technical significance of the first threshold value + T1 and the second threshold value-T2 will be described by taking the case where the number of clips is too small as an example.

The operation of the second adjustment motor 76 is controlled so as to be at the rotation position commanded by the controller 80. When the number of clips is within an appropriate range, the second adjustment motor 76 sets the torque for the mechanical loss (mechanical loss) for setting the commanded rotation position (hereinafter, the torque value T for the mechanical loss is "mechanical loss". Torque T0 ”) is generated. The mechanical loss torque T0 is a torque generated by rotating the second adjusting motor 76 to drive the pitch setting rail 12, and is + T0 when the second adjusting motor 76 rotates in the reverse direction and −T0 when the second adjusting motor 76 rotates in the forward direction. Torque is generated. That is, when the number of clips is in an appropriate range, the torque value T generated by the second adjusting motor 76 is in the range of + T0 to −T0 (+ T0 ≧ T ≧ −T0).

When the number of clips is too small, the clip unit CU is pressed against the rail unit 15 toward the film side (lower direction in FIG. 5). The pitch setting rail 12 is pressed in the direction approaching the reference rail 11 by the pressing force received from the pitch setting roller 57 of the clip unit CU. This pressing force acts on the second adjusting motor 76 via the screw mechanism 77 as torque in the direction of forward rotation.

Therefore, unless the command of the rotation position changes, the second adjustment motor 76 prevents the pitch setting rail 12 from moving toward the reference rail 11 due to the pressing force received from the clip unit CU (holds the pitch setting rail 12). The operation is controlled. That is, in addition to the mechanical loss torque T0, the second adjusting motor 76 generates a torque in the reverse rotation direction so as to oppose the torque in the forward rotation direction generated by the pressing force. As a result, the second adjusting motor 76 will generate a torque exceeding the range of mechanical loss torque + T0 to −T0 in order to set the predetermined rotation position. When the number of clips is too small, the second adjusting motor 76 generates a torque in the reverse rotation direction, that is, a positive torque. Therefore, by comparing the first threshold value + T1 which is a positive threshold value with the torque value T, It is possible to determine whether the number of clips is too small.

On the contrary, when the number of clips is excessive, the direction of the pressing force acting on the rail unit 15 from the clip unit CU is opposite, so that the direction of the torque generated by the second adjusting motor 76 to resist the pressing force is opposite. Is also the opposite. Therefore, the second threshold value-T2, which is a negative threshold value, is a threshold value for determining an excess number of clips.

As described above, the positive threshold value, the first threshold value + T1, is for determining whether or not the number of clips is too small, and the negative threshold value, the second threshold value-T2, is for determining whether or not the number of clips is excessive. It is for doing. The first threshold value + T1 is a value larger than the mecha loss torque + T0, and the second threshold value -T2 is a value smaller than the mecha loss torque -T0.

Hereinafter, the pitch adjustment method in the TD direction and the MD direction of the clip unit CU in the stretching device 100 will be specifically described with reference to the flowcharts shown in FIGS. 7 and 8.

The pitch adjustment in the TD direction and the MD direction is performed without supplying the film to the stretching device 100. This makes it possible to reduce film loss and save energy in pitch adjustment. Further, a sensor for detecting that the film is not supplied to the stretching device 100 is provided, and when the sensor detects that the film is not supplied, the pitch adjustment in the TD direction and the MD direction is executed. You may. The pitch adjustment in the TD direction and the MD direction is not limited to that performed without supplying the film to the stretching device 100.

Further, the pitch adjustment in the TD direction and the MD direction is performed in a state where the temperature of the film transport region is not raised. This makes it possible to save energy in pitch adjustment. Further, in this case, for example, when it is detected that the temperature of the film transport region has not been raised based on the ON-OFF signal of the temperature sensor or the heater, the pitch adjustment in the TD direction and the MD direction is executed. It may be configured as. The pitch adjustment in the TD direction and the MD direction is not limited to that performed when the film transport region is not heated.

The controller 80 executes the process shown in FIG. 7 when the pitch setting condition is input by the operator and the automatic adjustment button (not shown) is pressed.

In the process shown in FIG. 7, adjustment (automatic scaling) of the TD pitch and the MD pitch is executed in steps S10 to S18. In the automatic scaling, the pitch in the TD direction is adjusted first in steps S10 to S13, and then the pitch in the MD direction is adjusted in steps S14 to S17. In steps S19 to S21, the final adjustment (number matching) of the number of clips is executed. Hereinafter, each step will be specifically described.

In step S10, the conditions for scaling in the TD direction are set based on the conditions set by the operator. Specifically, the TD pitch, which is a condition set by the operator, is calculated, and the rotation position of each first adjustment motor 72 in the extension zone Zb that realizes the TD pitch is calculated. Then, in step S11, an energization command is transmitted to the driver (not shown) of each first adjustment motor 72 so as to reach the calculated rotation position, and the first adjustment motor 72 is driven.

In step S12, the number of clips is adjusted in parallel with driving the first adjustment motor 72 to adjust the TD pitch in step S11. The clip number adjustment process is a process of adjusting the number of clips by monitoring the torque of the second adjustment motor 76 while the first adjustment motor 72 is driven to the rotation position that is the condition set in step S11. The clip number adjustment process will be described in detail later. When the first adjustment motor 72 is driven to the rotation position calculated in step S10 and the clip number adjustment process in step 13 is completed, the adjustment in the TD direction is completed (step S13).

Next, in step S14, the conditions for scaling in the MD direction are set based on the conditions set by the operator. Specifically, the MD pitch that is a condition set by the operator is calculated, and the rotation position of each second adjustment motor 76 in the extension zone Zb that realizes the MD pitch is calculated. Then, in step S15, an energization command is transmitted to the driver of each second adjustment motor 76 so as to reach the calculated rotation position, and the second adjustment motor 76 is driven. The clip number adjustment process is executed until the second adjustment motor 76 is driven to the calculated rotation position (step S16). When the second adjustment motor 76 is driven to the calculated rotation position and the number adjustment process in step S16 is completed, the adjustment in the MD direction is completed (step S17). The clip number adjustment process in step S16 is the same as the clip number adjustment process in step S12. Further, after reaching the calculated rotation position, the second adjustment motor 76 is controlled to maintain the rotation position again.

When both the TD pitch and the MD pitch are adjusted in this way, the automatic scaling is completed (step S18).

Here, the clip number adjustment process in steps S12 and S16 will be described with reference to FIG. As described above, steps S12 and S16 differ only in the execution timing of whether the TD pitch is being adjusted or the MD pitch is being adjusted.

As shown in FIG. 8, in the clip number adjustment process, first, in step S30, the torque value T as load data is acquired from the torque sensor 78 of each second adjustment motor 76.

In steps S31 and S33, the torque value T acquired in step S30 is compared with a predetermined threshold value (first threshold value + T1, second threshold value-T2).

In step S31, it is determined whether the acquired torque value T of the second adjustment motor 76 is equal to or less than the first threshold value + T1. When the torque value T exceeds the first threshold value + T1, the number of clips is too small as described above. Therefore, in step S32, the first sprockets 62L and 62R on the outlet side are temporarily decelerated. It controls the operation of the drive motor 64L. As a result, the number of clips is increased, and the load acting on the pitch setting rail 12 (in other words, the absolute value of the torque value T of the second adjusting motor 76) is reduced as the number of clips increases. If the torque value T is equal to or less than the first threshold value + T1, the process proceeds to step S33.

In step S33, it is determined whether the torque value T of the second adjustment motor 76 is equal to or greater than the second threshold value −T2. When the torque value T is lower than the second threshold value −T2, the number of clips is excessive, so that the first drive motor 64L and the first drive motor 64L and 62R are temporarily accelerated in step S34. It controls the operation of the second drive motor 64R. As a result, the number of clips is reduced, and the load acting on the pitch setting rail 12 (in other words, the absolute value of the torque value T of the second adjusting motor 76) is reduced as the number of clips is reduced. If the torque value T is equal to or greater than the second threshold value −T2, the process proceeds to step S35.

In step S35, it is determined whether the first adjustment motor 72 or the second adjustment motor 76 has been driven to the commanded rotation position, in other words, whether the TD pitch / MD pitch, which is the condition set by the operator, has been realized. If the set pitch is not realized, the process returns from step S35 to step S30, and the processing from step S30 is executed again. If the set pitch is realized, the clip number adjustment process is completed, and the process returns to step S13 or S16 shown in FIG. As described above, the processes shown in steps S30 to S35 of FIG. 8 are executed in parallel while the first adjustment motor 72 or the second adjustment motor 76 is driven so as to realize the set TD pitch or MD pitch. Will be done.

As described above, after adjusting the number of clips so that the torque value of the second adjusting motor 76 does not exceed the threshold value and adjusting the TD pitch and the MD pitch to the desired pitch, steps S19 to S19 shown in FIG. 7 are performed. In S21, the number of clips is adjusted.

In step S19, the number of clips is measured. In step S20, it is determined whether or not the number matching button has been pressed by the operator.

When the number matching button is pressed, the process proceeds to step S21, and the number of clips is automatically adjusted. Specifically, it is determined whether the number of clips measured in step S19 matches the target number calculated from the conditions set in step S10, and if they do not match, the number of clips measured is the number of clips measured. The rotation speeds of the first drive motor 64L and the second drive motor 64R are temporarily accelerated or decelerated according to the difference between the number of clips and the target number so as to reach the target number. As a result, the number of clips is adjusted to be the target number. When the number of clips is adjusted, the process ends.

The matching of the number of clips shown in step S21 will be described in detail.

The relationship between the number of clips and the rotation of the first drive motor 64L and the second drive motor 64R can be grasped in advance from the specifications of each configuration and the like. That is, the relationship between how much the outlet side sprockets 62L and 62R are advanced or retarded with respect to the inlet side sprockets 61L and 61R and how much the number of clips increases or decreases is known in advance. Therefore, for example, when the actual number of clips is larger than the set number, the outlet side sprockets 62L and 62R are advanced by an angle corresponding to the difference in the number of clips over a predetermined time. That is, the rotation speeds of the outlet side sprockets 62L and 62R are temporarily increased. As a result, the clip unit CU temporarily and quickly passes through the outlet- side sprockets 62L and 62R and is discharged from the stretched region, so that the number of clips is reduced. After the number of clips is adjusted, the inlet side sprockets 61L and 61R and the outlet side sprockets 62L and 62R rotate again in synchronization at the same speed.

On the contrary, when the actual number of clips is less than the set number, the outlet side sprockets 62L and 62R are retarded by the angle corresponding to the difference in the number (temporarily reduce the speed). As a result, the clip unit CU temporarily passes through the outlet side sprockets 62L and 62R and is discharged from the stretched region, so that the number of clips increases. In this way, the number of clips is adjusted and the process ends.

It is desirable that the number matching shown in step S21 be performed in a state where the temperature in the film transport region is stable at the temperature at which the film is actually stretched. According to this, the number of clips can be adjusted by eliminating the influence of thermal expansion of the clip unit CU or the like.

Hereinafter, the action and effect of this embodiment will be described.

The stretching device 100 that stretches the conveyed film vertically and horizontally defines a non-endless circulation path and defines a pair of rail devices 10L and 10R arranged on the left and right sides of the film and a pair of rail devices 10L and 10R. A plurality of clip unit CUs that run and grip a film, a link mechanism 50 that connects adjacent clip unit CUs on a circulation path, a drive mechanism 60 that runs the clip unit CU along the circulation path, and a clip unit CU. The adjustment mechanism 70 that adjusts the vertical pitch and the horizontal pitch, the controller 80 that controls the operation of the drive mechanism 60 and the adjustment mechanism 70, and the clip unit CU detect the load acting on the rail devices 10L and 10R. The clip unit CU includes a detection unit (torque sensor 78), and the clip unit CU engages with the rail devices 10L and 10R to guide the movement of the clip unit CU along the circulation path (guide roller 56, pitch setting roller 57). ), And the drive mechanism 60 is provided on the left and right sides of the film on the inlet side where the film is supplied, and on the pair of inlet sprockets 61L and 61R that engage with the clip unit CU and on the outlet side where the stretched film is sent out. A pair of outlet- side sprockets 62L, 62R provided on both the left and right sides of the film and engaged with the clip unit CU, a first drive unit 64 for rotationally driving the outlet- side sprockets 62L, 62R, and an inlet- side sprockets 61L, 61R are rotationally driven. The controller 80 controls the operation of the first drive unit 64 according to the load acting on the rail devices 10L and 10R from the clip unit CU detected by the detection unit.

Further, the method of adjusting the number of clips executed by the controller 80 of the stretching device 100 includes a step of acquiring load data representing the magnitude of the load acting on the rail devices 10L and 10R from the clip unit CU traveling on the circulation path, and load data. It is provided with a step of controlling the rotation speed of the outlet side sprockets 62L and 62R according to the above.

In such a stretching device 100 and the clip number adjusting method, the controller 80 controls the operation of the first drive unit 64 according to the load acting on the rail devices 10L and 10R from the clip unit CU to grip the film. The number of clip unit CUs is adjusted. Therefore, manual adjustment by an operator is not required, and the number of clips can be easily adjusted.

Further, in the stretching device 100, the rail devices 10L and 10R have a reference rail 11 and a pitch setting rail 12 in which the distance between the reference rail 11 is variable, and the roller portion is engaged with the reference rail 11. The link mechanism 50 includes a matching first roller (guide roller 56) and a second roller (pitch setting roller 57) that engages with the pitch setting rail 12, and the link mechanism 50 has one end connected to the second roller and the other end. The first link member 53 connected to the first roller of the adjacent clip unit CU, one end connected to the first roller, and the other end connected to the intermediate portion between one end and the other end of the first link member 53. The adjustment mechanism 70 has an adjustment motor (second adjustment motor 76) that advances and retreats the pitch setting rail 12 with respect to the reference rail 11.

Further, in the stretching device 100, the detection unit is a torque sensor 78 that detects the torque value T of the adjustment motor, and the controller 80 is the case where the torque value T of the adjustment motor exceeds the first threshold value + T1 which is a positive value. When either the rotation speed of the outlet side sprocket 62L or 62R is increased or decreased and the torque value T of the adjusting motor falls below the negative value of the second threshold value -T2, the outlet side is used. Either increase or decrease the rotational speed of the sprocket 62L, 62R is performed.

Further, in the clip number adjusting method, the load data is the torque value of the adjusting motor, and in the step of controlling the rotation speed of the outlet side sprocket, the torque value of the adjusting motor exceeds the first threshold value + T1 which is a positive value. In that case, either the rotation speed of the outlet side sprocket is increased or decreased, and when the torque value of the adjusting motor falls below the negative value of the second threshold value -T2, the outlet side sprocket 62L, Either an increase or decrease in the rotational speed of 62R is performed.

In such a stretching device 100, by using two threshold values of the first threshold value + T1 and the second threshold value-T2, it is possible to determine whether or not the number of clips is too small or too large. Therefore, the number of clips can be adjusted to an appropriate number with higher accuracy.

Further, the stretching device 100 further includes a number measuring unit (counting sensor 81) for measuring the number of clip unit CUs that grip the film, and the controller 80 further includes the actual number of clip unit CUs measured by the number measuring unit and a target. The operation of the first drive unit 64 is controlled based on the difference from the number.

In such a stretching device 100, since the actual number of clip unit CUs is measured and then the operation of the first drive unit 64 is controlled to adjust the number, the number of clip units CUs that grip the film is more reliably targeted. Can be.

Although the embodiments of the present invention have been described above, the above embodiments are only a part of the application examples of the present invention, and the technical scope of the present invention is limited to the specific configurations of the above embodiments. No.

In the above embodiment, the left and right outlet side sprockets 62L and 62R are rotationally driven in synchronization with each other. On the other hand, the left and right outlet side sprockets 62L and 62R may be rotationally driven independently of each other. In this case, the number of clips on the right side may be adjusted according to the torque value T of the second adjusting motor 76 on the right side, and the number of clips on the left side may be adjusted according to the torque value T of the second adjusting motor 76 on the left side. good. That is, the adjustment of the number of clips may be performed independently on the left and right.

Further, in the above embodiment, the left and right clip unit CUs travel on the patrol route so that the corresponding clip unit CUs are lined up in the left-right direction. Further, when compared at the same vertical position, the MD pitches of the clip unit CU on the right side and the clip unit CU on the left side are the same as each other. On the other hand, the MD pitch may be different on the left and right. That is, the left and right clip unit CUs corresponding to each other may not be lined up in the left-right direction but may be displaced in the vertical direction. By making the left and right MD pitches different, the film can be stretched in an oblique direction (a direction in which the film is inclined in both the vertical direction and the horizontal direction in the plane shown in FIG. 1).

Further, in the above embodiment, the heat treatment zone Zc is not stretched in the vertical direction or the horizontal direction. On the other hand, in the heat treatment zone Zc, the MD pitch may be reduced to shrink the film in the MD direction. As a result, the amount of stretching of the left and right central portion of the film is smaller than that of the left and right edge portions of the film gripped by the clip 20, and the film is constricted (in other words, the left and right edge portions of the film protrude in the transport direction from the central portion. It is possible to suppress the occurrence of the so-called Boeing phenomenon.

Further, in the above embodiment, the case of adjusting the pitches in both the TD direction and the MD direction has been described, but the stretching device 100 can also adjust the pitches in either the TD direction or the MD direction. In this case, the processing according to the direction in which the adjustment is not performed (steps S10 to S13 or steps S14 to S17 shown in FIG. 7) may be omitted.

Further, in the above embodiment, the detection unit is the torque sensor 78 of the second adjustment motor 76, and the torque value of the second adjustment motor 76 is used as load data. On the other hand, the load data is not limited to the torque value of the second adjusting motor 76, and the detection unit is not limited to the torque sensor 78. For example, the load torque calculated based on the voltage value, the current value, the frequency, and the like input to the second adjusting motor 76 may be used as the torque value of the second adjusting motor 76 without providing the torque sensor 78. Further, instead of the torque value, the current value to the second adjusting motor 76 may be used as the load data. Further, a load sensor may be provided as a detection unit instead of the torque sensor 78, and the load sensor may detect the load acting on the pitch setting rail 12 from the pitch setting roller 57 as load data. Further, a displacement sensor may be provided as a detection unit, and the displacement sensor may detect the deflection (deformation) of the pitch setting rail 12 due to the load acting on the pitch setting rail 12 from the pitch setting roller 57 as load data.

Further, in the above embodiment, the torque in which the second adjusting motor 76 rotates in the reverse direction (the pitch setting rail 12 is separated from the reference rail 11) is described as a positive torque value. On the other hand, the positive / negative setting of the torque value is not limited to the above configuration and may be set arbitrarily. Correspondingly, the positive and negative values can be arbitrarily set for the first threshold value and the second threshold value. Further, the magnitudes (absolute values) of the first threshold value and the second threshold value can be arbitrarily set as long as the number of clips is not adjusted at the normal time when the number of clips is appropriate. That is, in the stretching device 100, a threshold value for determining whether the number of clips is too small and a threshold value for determining whether the number of clips is excessive are set, and the number of clips is appropriate according to the number of clips. It is desirable to control the operation of the outlet side sprockets 62L and 62R so as to be. As long as it is configured in this way, the setting of the torque value and the specific contents of the threshold value are not limited to the above-described embodiment.

For example, contrary to the above embodiment, when the torque in the direction in which the second adjusting motor 76 rotates in the forward direction (the pitch setting rail 12 approaches the reference rail 11) is set as a positive torque value, the first value is a positive value. The threshold value + T1 means a threshold value for determining whether the number of clips is excessive, and the second threshold value-T2, which is a negative value, means a threshold value for determining whether the number of clips is too small. In this case, when the torque value of the second adjusting motor 76 exceeds the first threshold value + T1, the rotation speeds of the outlet side sprockets 62L and 62R are increased, and the torque value of the second adjusting motor 76 sets the second threshold value-T2. If it falls below the limit, the rotation speed of the outlet- side sprockets 62L and 62R may be controlled to decrease. Even in this case, the same effect as that of the above embodiment is obtained. That is, the meanings of the first threshold value + T1 and the second threshold value-T2 are interchanged depending on how the positive and negative torque values are set. Correspondingly, when the torque value of the second adjusting motor 76 exceeds the first threshold value + T1, the rotation speeds of the outlet side sprockets 62L and 62R are increased or decreased, or fall below the second threshold value-T2. In this case, the rotation speeds of the outlet- side sprockets 62L and 62R are switched to be reduced or increased, respectively. Therefore, when the torque value T of the second adjusting motor 76 exceeds the first threshold value + T1 which is a positive value, the controller 80 either increases or decreases the rotation speed of the outlet side sprockets 62L and 62R. When the torque value T of the second adjusting motor 76 falls below the negative value of the second threshold value -T2, either the rotation speed of the outlet side sprockets 62L or 62R is increased or decreased, or the other is executed. It is desirable that it is configured as follows.

Further, in the above embodiment, the first threshold value + T1 and the second threshold value-T2 are common depending on whether the second adjustment motor 76 rotates in the forward direction or in the reverse direction. On the other hand, different first threshold value + T1 and second threshold value-T2 may be set depending on whether the second adjustment motor 76 rotates in the forward direction or in the reverse direction. For example, when the mechanical loss of rotating the second adjustment motor 76 to move the pitch setting rail 12 is large, the first threshold value + T1 and the second threshold value-T2 when the second adjustment motor 76 rotates in the positive direction, It is desirable to individually set the first threshold value + T1 and the second threshold value-T2 when rotating in the opposite direction.

When the magnitude (absolute value) of the mechanical loss is small, the threshold value (first threshold value + T1, second threshold value-T2) and the mechanical loss torque (+ T0,-) and the mechanical loss torque (+ T0,-) are used depending on whether the second adjustment motor 76 rotates forward or backward. There is no large difference in the difference from T0). That is, to explain the first threshold value + T1 as an example, the difference (+ T1 + T0) from the mechanical loss torque −T0 when the first threshold value + T1 and the second adjustment motor 76 rotate in the forward direction, and the first threshold value + T1 and the second adjustment motor 76 The difference (+ T1-T0) from the mechanical loss torque + T0 when rotating in the reverse direction does not change significantly. Therefore, even if the first threshold value + T1 and the second threshold value-T2 are used in common regardless of the rotation direction of the second adjustment motor 76 as in the above embodiment, the adjustment of the number of clips has a large effect. No.

On the other hand, if the mechanical loss is large, the difference between the threshold value and the mechanical loss torque will be relatively large between the case where the second adjustment motor 76 rotates in the forward direction and the case where the second adjustment motor 76 rotates in the reverse direction. Therefore, if the first threshold value + T1 and the second threshold value-T2 are shared regardless of the rotation direction of the second adjustment motor 76, when the second adjustment motor 76 rotates in the reverse direction, the first threshold value + T1 and the mechanical loss torque + T0 are obtained. Since the difference between the two is relatively small, the clip number adjustment process is executed even if the number of clips is slightly excessive. On the other hand, when the second adjustment motor 76 rotates in the forward direction, the difference between the first threshold value + T1 and the mechanical loss torque −T0 becomes relatively large. Therefore, when the second adjustment motor 76 rotates in the forward direction, the clip number adjustment process is not executed even if the number of clips is excessive by the same number as in the case of the reverse rotation, and is executed unless the number of clips is excessive. Not done. In this way, if the first threshold value + T1 and the second threshold value-T2 are shared between the case where the second adjustment motor 76 rotates in the forward direction and the case where the second adjustment motor 76 rotates in the reverse direction, the same number may be excessive or too small. Regardless, the number of clips may or may not be adjusted depending on the rotation direction of the second adjustment motor 76. That is, the timing at which the number of clips is adjusted may differ depending on the rotation direction of the second adjustment motor 76.

On the other hand, the first threshold value + T1 and the second threshold value-T2 are set for the rotation direction of the second adjustment motor 76, respectively (that is, the first threshold value + T1 and the second threshold value-T2 for forward rotation and the reverse rotation. By setting a total of four threshold values, that is, the first threshold value + T1 and the second threshold value-T2), if the number of clips is the same, the number of clips is excessive or too small. Regardless, the number of clips can be adjusted at the same timing. For example, the first threshold value + T1 and the second threshold value-T2 are set as if the predetermined torque values Td are increased or decreased (T1 = ± T0 + Td, T2 = ± T0-Td) with respect to the mechanical loss torque + T0 and -T0, respectively. Just do it. As a result, the timing at which the control of the number of clips is executed can be made constant, so that the number of clips can be adjusted stably.

Further, when the first threshold value and the second threshold value are individually set according to the rotation direction of the second adjustment motor 76, the first threshold value and the second threshold value may be set to have the same positive and negative values. Specifically, for example, the first threshold value may be set as a threshold value having a positive value, and the second threshold value may be set as a threshold value having a positive value smaller than the first threshold value. In this way, the second threshold value is set as a value smaller than the first threshold value regardless of whether it is positive or negative with the first threshold value. In this case, when the torque value T of the second adjustment motor 76 is within the range between the first threshold value and the second threshold value, the number of clips is not adjusted as in the above embodiment. When the torque value T of the second adjusting motor 76 exceeds the first threshold value, the number of clips is increased by temporarily decelerating the outlet- side sprockets 62L and 62R, assuming that the number of clips is too small. When the torque value T of the second adjusting motor 76 is lower than the second threshold value, the number of clips is reduced by temporarily accelerating the outlet side sprockets 62L and 62R, assuming that the number of clips is excessive. As described above, even if the first threshold value and the second threshold value are set as threshold values having the same positive and negative values, the same action and effect as those of the above-described embodiment can be obtained. Further, either the first threshold value or the second threshold value may be set as zero.

Further, in the above embodiment, the inlet side sprockets 61L and 61R are driven by a common third drive motor 65. On the other hand, the left and right inlet- side sprockets 61L and 61R may be independently driven by electric motors different from each other. That is, the second drive unit 65 may have an electric motor for driving the left inlet side sprocket 61L and an electric motor for driving the right inlet side sprocket 61R.

Further, in the above embodiment, the operation of the outlet side sprockets 62L and 62R is controlled while the inlet side sprockets 61L and 61R and the outlet side sprockets 62L and 62R are rotationally driven and the clip unit CU is traveling on the circulation path. , Adjust the number of clips. On the other hand, the operation of the first drive unit 64 and the second drive unit 65 may be stopped, and the number of clips may be adjusted while the traveling of the clip unit CU on the circulation path is stopped. That is, the processes of steps S10 to S18 shown in FIG. 7 and steps S30 to S35 shown in FIG. 8 may be executed in a state where the operations of the first drive unit 64 and the second drive unit 65 are stopped.

Further, in the above embodiment, the number of clips is adjusted by controlling the operation of the first drive unit 64 to temporarily increase or decrease the rotation speed of the outlet side sprockets 62L and 62R. On the other hand, the number of clips may be adjusted by controlling the operation of the second drive unit 65 to temporarily increase or decrease the rotation speed of the inlet- side sprockets 61L and 61R. Further, the number of clips may be adjusted by controlling the rotation speeds of both the inlet side sprockets 61L and 61R and the outlet side sprockets 62L and 62R. That is, the number of clips can be adjusted by controlling the operation of at least one of the inlet side sprockets 61L and 61R and the outlet side sprockets 62L and 62R. In any case, the number of clips of the inlet side sprockets 61L and 61R and the outlet side sprockets 62L and 62R decreases and rotates when the operation is controlled so that the difference in rotation speed between them temporarily increases. The number of clips decreases when the speed difference is controlled to be temporarily small.

This application claims priority based on Japanese Patent Application No. 2020-76181 filed with the Japan Patent Office on April 22, 2020, and the entire contents of this application are incorporated herein by reference.

Claims (6)

1. A stretching device that stretches the film to be conveyed vertically and horizontally.
   A rail device that defines an endless circulation path and is arranged on both the left and right sides of the film.
   A plurality of clip units that travel along the circulation path of the rail device and grip the film, and
   A link mechanism that connects adjacent clip units on the circulation path, and
   A drive mechanism that causes the clip unit to travel along the circulation path, and
   An adjustment mechanism that adjusts the vertical pitch and horizontal pitch of the clip unit, and
   A controller that controls the operation of the drive mechanism and the adjustment mechanism and acquires load data representing the load acting on the rail device from the clip unit is provided.
   The clip unit has a roller portion that engages with the rail device and guides the movement of the clip unit along the circulation path.
   The drive mechanism
   On the inlet side where the film is supplied, sprockets on the inlet side provided on both the left and right sides of the film and engaging with the clip unit, and
   Outlet-side sprockets provided on the left and right sides of the film on the outlet side for delivering the stretched film and engaging with the clip unit.
   A first drive unit that rotationally drives the outlet-side sprocket, and
   It has a second drive unit that rotationally drives the inlet side sprocket, and has.
   The controller controls the operation of at least one of the first drive unit and the second drive unit according to the load acting on the rail device from the clip unit.
   Stretching device.
2. The stretching device according to claim 1.
   The rail device
   With the reference rail
   It has a pitch setting rail in which the distance from the reference rail is variable.
   The roller portion is
   The first roller that engages with the reference rail and
   Includes a second roller that engages the pitch setting rail.
   The link mechanism
   A first link member having one end connected to the second roller and the other end connected to the first roller of the adjacent clip unit.
   It has a second link member, one end of which is connected to the first roller and the other end of which is connected to an intermediate portion between the one end and the other end of the first link member.
   The adjusting mechanism includes an adjusting motor that advances and retreats the pitch setting rail with respect to the reference rail.
   Stretching device.
3. The stretching device according to claim 2.
   The controller acquires the torque value of the adjustment motor as the load data, and when the torque value of the adjustment motor exceeds the first threshold value, the rotation speed of the outlet side sprocket and the inlet side sprocket. When either the difference is increased or decreased and the torque value of the adjusting motor falls below the second threshold value smaller than the first threshold value, the rotation of the outlet side sprocket and the inlet side sprocket is performed. Perform either an increase or decrease in the speed difference, the other
   Stretching device.
4. The stretching device according to any one of claims 1 to 3.
   A number measuring unit for measuring the number of the clip units that grip the film is further provided.
   The controller controls the operation of the first drive unit based on the difference between the actual number of the clip units measured by the number measuring unit and the target number.
   Stretching device.
5. A rail device that is placed on both the left and right sides of the film to be conveyed and defines an endless circulation path,
   A plurality of clip units that travel along the circulation path of the rail device and grip the film, and
   A link mechanism that connects adjacent clip units on the circulation path, and
   The film is gripped by a controller of a stretching device including a drive mechanism that rotationally drives an inlet-side sprocket and an outlet-side sprocket that engage the clip unit to allow the clip unit to travel along the circulation path. This is a method for adjusting the number of clips that adjusts the number of the clip units.
   A step of acquiring load data representing a load acting on the rail device from the clip unit, and
   A method for adjusting the number of clips, which comprises a step of controlling the rotation speed of at least one of the outlet side sprocket and the inlet side sprocket according to the load data.
6. The method for adjusting the number of clips according to claim 5.
   The rail device
   With the reference rail
   It has a pitch setting rail in which the distance from the reference rail is variable.
   The load data is a torque value of an adjustment motor that advances and retreats the pitch setting rail with respect to the reference rail.
   In the step of controlling the rotation speed of at least one of the outlet side sprocket and the inlet side sprocket, when the torque value of the adjustment motor exceeds the first threshold value, the rotation of the outlet side sprocket and the inlet side sprocket When either the speed difference is increased or decreased and the torque value of the adjusting motor falls below the second threshold value smaller than the first threshold value, the outlet side sprocket and the inlet side sprocket are used. Either an increase or decrease in the rotational speed difference is performed,
   How to adjust the number of clips.

Images