JP2001198976A - Roll peripheral velocity control device for longitudinal stretching machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roll peripheral velocity control device for a longitudinal stretching machine which realizes a change in the peripheral velocity of a roll easily and in a short time, besides with high precision when such a velocity change is necessary, and has such advantages that the velocity change range can be widened and the whole speed change gear can be made compact to save on an installation space for the entire device. SOLUTION: A servo motor 32 is provided which rotates and drives the center shaft 20 of a cam 9 for a differential gear mechanism 7. In addition, a controller 34 is provided which controls the servo motor 32 based on the rotary state of a roll 2a on the drive side of the longitudinal stretching machine 1 and controls the peripheral velocity of the rotation of a roll 2b on the driven side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll peripheral speed control device for a longitudinal stretching machine for controlling the roll peripheral speed of a longitudinal stretching machine for strips such as plastic films to be continuously variable.

[0002]

2. Description of the Related Art A longitudinal stretching machine for a plastic film uses a plurality of rolls to perform processes such as preheating, stretching, cooling and heat setting for removing internal strain and stabilizing a product form. It is a machine to make. FIG. 2 shows an example of a roll arrangement of the longitudinal stretching machine 1. In the longitudinal stretching machine 1, a plurality of rolls 2a to 2j are arranged in a substantially staggered arrangement or a horizontal arrangement to form a transport path for the plastic film 3. In FIG. 2, the rolls 2a to 2d are preheating rolls, the rolls 2e and 2f are stretch rolls, and the rolls 2g to 2j are heat set and cooling rolls after stretching.

The film 3 traveling on the transport path of the film 3 is preheated on the surface of a plurality of heated preheating rolls 2a to 2d, and is stretched longitudinally by stretching the film 3 in the film traveling direction by stretching rolls 2e to 2f. , Cooling rolls 2g to 2j
And heat set.

In this type of longitudinal stretching machine 1, the film 3 of the preheated rolls 2a to 2d sequentially expands due to thermal expansion, and gradually becomes loose on the rolls 2a to 2d. In order to prevent this slack, each of the preheating rolls 2a to 2d is increased by a predetermined speed (increased speed) from the peripheral speed of the immediately preceding roll. The preheating rolls 2a to 2d may be used not only for preheating but also for cooling.

A plurality of preheating rolls 2a of the longitudinal stretching machine 1
As a transmission device for feeding and longitudinally stretching the film 3 by giving a peripheral speed difference to the rotation of ~ 2d, for example, Japanese Patent Publication No. 2-473
There is a continuously variable transmission disclosed in Japanese Patent Publication No. 35-35. Here, as shown in FIG. 3, one end of a rotating shaft 4 of a roll 2 a serving as a peripheral speed reference of the continuously variable transmission on the side of the preheating rolls 2 a to 2 d is connected to a driving source 5.

A power transmission mechanism 6 for transmitting the rotation of the drive side roll 2a to the driven side roll 2b is provided with a differential gear mechanism 7 (a differential unit manufactured by Harmonic Drive Systems). . The differential gear mechanism 7 has a circular spline S as an input-side rotating element, a circular spline D as an output-side rotating element, and an elasticity for transmitting the rotation of the circular spline S to the circular spline D side. A flexspline 8 which is a ring, and a speed changing means for deforming the flexspline 8 to shift the rotation of the output circular spline D with respect to the rotation of the input circular spline S of the differential gear mechanism 7. A certain cam 9 is provided.

Further, a power transmission gear 10 for driving each of the rolls 2b to 2d on the downstream side of the roll 2a is provided on a rotating shaft 4 of the roll 2a, and a timing belt provided for continuously variable transmission of the roll 2b. Pulley 11 is attached. Here, the power transmission gear 10 sequentially meshes with the gear 13 fixed to the circular spline S of the differential gear mechanism 7 via the idle gear 12, and
The spline S is driven to rotate.

The timing belt pulley 11 is connected to a pulley 16 provided on an input shaft 15 of the continuously variable transmission 14 by a timing belt 17. Further, an output side pulley 19 is attached to an output shaft 18 of the continuously variable transmission 14. Here, the differential gear mechanism 7 is provided with a center shaft (drive shaft) 20 that passes through the center hole of the cam 9 and is fixed to the cam 9 by a key. A pulley 21 is attached to the center shaft 20. The pulley 19 of the continuously variable transmission 14 and the pulley 21 of the differential gear mechanism 7 are connected by a timing belt 22 so as to rotate the center shaft 20 of the cam 9.

A gear 2 is provided on a rotating shaft 23 of the roll 2b.
4 are attached. The gear 24 is meshed with a gear 25 fixed to the circular spline D. Thus, the rotation of the output-side circular spline D is transmitted to the roll 2b via the meshing portion between the gear 25 and the gear 24, and the roll 2b is driven.

In the above-described conventional apparatus, the flex spline 8 is deformed by operating the cam 9 of the differential gear mechanism 7 so that the rotation of the circular spline S on the input side of the differential gear mechanism 7 is prevented. The peripheral speed of rotation between the rolls 2a and 2b is controlled by changing the rotation of the circular spline D on the output side.

The power transmission mechanism between the rolls 2a and 2b, between the rolls 2b and 2c, and between the rolls 2c and 2d is the same as the power transmission mechanism 6 between the rolls 2a and 2b. However, there is no drive source from the roll 2b to the roll 2d, and power is transmitted from the rotating shaft 4 of the roll 2a. Thereby, the peripheral speed of rotation of each of the preheating rolls 2a to 2d is controlled.

Further, as the continuously variable transmission 14 for operating the rotation of the cam 9, a continuously variable cup by friction transmission in which a drive cone is attached to each of an input shaft and an output shaft is used. Note that the cam 9 is
There is also a configuration in which the rotation of the is operated.

[0013]

[Problems to be Solved by the Invention]
In the continuously variable transmission disclosed in the above publication, a continuously variable transmission 14 is used to drive a cam 9 which is a transmission means of the differential gear mechanism 7. However, when the speed of the differential gear mechanism 7 is changed using the continuously variable transmission 14, the rotation of the input side circular spline S of the differential gear mechanism 7 causes the output side circular spline D to rotate. However, since the speed ratio at the time of shifting the rotation of the preheating rollers 2a to 2d is relatively narrow, there is a problem that the range of the peripheral speed of rotation of each of the preheating rolls 2a to 2d is narrow.

Further, since the continuously variable transmission 14 has a complicated internal structure of the transmission main body and the entire transmission main body becomes large, the continuously variable transmission 14 has the same number of continuously variable transmissions as the plurality of rolls 2a to 2j. When installing the transmission 14, a large space is required for installing the continuously variable transmission 14. Therefore, the longitudinal stretching machine 1
There is a problem that the whole becomes large.

Further, when a continuously variable cup transmission or the like is used as the continuously variable transmission 14, power is transmitted by friction transmission by the drive cone, so that there is a problem such as slippage due to abrasion and rotation accuracy is reduced. There's a problem.

Further, when the rotation of the cam 9 as the speed change means of the differential gear mechanism 7 is operated by the timing pulley, the speed ratio is fixed, and the speed increase ratio of each of the preheating rolls 2a to 2d is constant. Each preheating roll 2a
When changing the peripheral speed of the rotation of ~ 2d, an operation of changing the pulley ratio is required.

The present invention has been made in view of the above circumstances, and its purpose is to change the roll peripheral speed when it is necessary.
A longitudinal stretching machine that can easily change the speed in a short time and with high precision, can widen the speed change range, and can reduce the installation space of the entire device by making the entire transmission compact. An object of the present invention is to provide a roll peripheral speed control device.

[0018]

According to a first aspect of the present invention, a plurality of heated rolls are provided in a plastic film conveying path, and a peripheral speed difference is given to the rotation of the rolls so that the film is moved in a feeding direction. A differential gear mechanism having a speed change means is interposed in a power transmission mechanism of a roll in a longitudinal stretching machine for pulling and longitudinal stretching, and an output is provided in response to rotation of the input side of the differential gear mechanism with operation of the speed change means. In the roll peripheral speed control device of the longitudinal stretching machine that controls the peripheral speed of the rotation of each roll by shifting the rotation of the side, a drive motor that rotationally drives a differential drive shaft of the transmission unit is provided, A roll peripheral speed control device for a vertical stretching machine, further comprising a controller that controls the drive motor based on the rotation state of a drive-side roll to control the peripheral speed of rotation of each roll. .

According to the first aspect of the present invention, when controlling the peripheral speed of the rotation of each roll of the longitudinal stretching machine, the controller controls the drive motor based on the rotation state of the drive-side roll. By directly rotating the differential drive shaft of the speed change means by means of a motor, the peripheral speed of the rotation of each roll can be changed with high accuracy over a wide range.

According to a second aspect of the present invention, the differential gear mechanism comprises:
The first internal gear on the input side to which the rotation of the roll on the drive side is transmitted, and the number of teeth are set to be different from those of the first internal gear, and are arranged coaxially with the first internal gear. A second internal gear; and an elastic ring formed by an external gear having the same number of teeth as the second internal gear, the elastic ring being locally meshed with the first internal gear, and the transmission means includes: A roll peripheral speed control for a longitudinal stretching machine, comprising: an elliptical cam disposed inside the ring to elastically deform the elastic ring to move a meshing portion between the external gear and the first internal gear. Device.

According to the second aspect of the present invention, when the differential gear mechanism operates, the rotation of the roll on the driving side is changed to the first rotation on the input side.
Of the differential gear mechanism by moving the meshing portion between the external gear and the first internal gear by elastically deforming the elastic ring by an elliptical cam disposed inside the elastic ring. In this case, the rotation on the output side is shifted with respect to the rotation on the input side.

According to a third aspect of the present invention, the controller comprises:
Connected to a speed detector that detects the rotation speed of the drive-side roll, detection data output from the speed detector and a preset set value of the speed-change speed of the driven-side roll with respect to the drive-side roll. A roll peripheral speed control device for a vertical stretching machine, wherein the control device controls the drive motor based on the following.

According to the third aspect of the present invention, the detection data output from the speed detector for detecting the rotation speed of the driving roll and the setting of the shift speed of the driven roll with respect to the driving roll set in advance. The drive motor is controlled by the controller based on the value.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIG. FIG. 1 shows a schematic configuration of a main part of a roll peripheral speed control device 31 of a longitudinal stretching machine of the present embodiment. Here, FIG. 1 explains the control of the roll peripheral speed between the roll 2a of the longitudinal stretching machine 1 of FIG. 2 and the speed change roll 2b.

That is, in the roll peripheral speed control device 31 of the longitudinal stretching machine 1 of the present embodiment, the preheating roll 2a
One end of the rotation shaft 4 of the roll 2 a serving as a reference of the peripheral speed on the side of 2 to 2 d is connected to the drive source 5.

A power transmission mechanism 6 for transmitting the rotation of the drive roll 2a to the speed change roll 2b is provided with a differential gear mechanism 7 (a differential unit manufactured by Harmonic Drive Systems). The differential gear mechanism 7 includes a circular spline (first internal gear) S as an input-side rotating element, a circular spline (second internal gear) D as an output-side rotating element, and a circular spline (D). A flexspline 8 which is an elastic ring for transmitting the rotation of the spline S to the circular spline D side, and the flexspline 8 is deformed to output an output with respect to the rotation of the circular spline S on the input side of the differential gear mechanism 7. And a cam 9 serving as speed change means for changing the speed of rotation of the circular spline D on the side.

Here, the circular spline S is formed by an internal gear having a predetermined number of spline-shaped internal teeth formed on the inner peripheral surface. Further, the circular spline D is formed by, for example, an internal gear having teeth of the same pitch as the circular spline S and having two fewer teeth than the number of teeth of the circular spline S.

The flex spline 8 is formed by an external gear having the same number of teeth as the internal gear of the circular spline D on the output side, and is formed by an elastic ring locally meshing with the internal gear of the circular spline S on the input side. Have been.

Further, the cam 9 is formed by an elliptical cam disposed inside the elastic ring of the flexspline 8. A center shaft (drive shaft) 2 is provided in the center hole of the cam 9.
0 is penetrated. Here, the cam 9 is fixed to the center shaft 20 by a key. The elastic ring of the flex spline 8 is elastically deformed by the rotation of the cam 9 to move the meshing portion between the internal gear of the circular spline S and the external gear of the flex spline 8, thereby moving the differential gear mechanism 7 The rotation on the output side is shifted relative to the rotation on the input side.

The rotating shaft 4 of the roll 2a has a roll 2
A power transmission gear 10 for driving each of the rolls 2b to 2d on the downstream side of a is mounted.
Here, the power transmission gear 10 sequentially meshes with the gear 13 fixed to the circular spline S of the differential gear mechanism 7 via the idle gear 12, so that the circular spline S is driven to rotate.

The rotating shaft 23 of the roll 2b has a gear 2
4 are attached. The gear 24 is meshed with a gear 25 fixed to the circular spline D. Thus, the rotation of the output-side circular spline D is transmitted to the roll 2b via the meshing portion between the gear 25 and the gear 24, and the roll 2b is driven.

The center shaft 2 of the cam 9 of the differential gear mechanism 7
A drive motor such as a servo motor 32 is attached to 0 in a directly connected state. The speed range of the servo motor 32 is set to, for example, about 100 to 2000 rpm.
The drive motor is not limited to the servo motor 32, and may be, for example, an inverter motor. Then, the center axis 2 of the cam 9 is
0 is rotated to drive the cam 9 to rotate.

The servo motor 32 is connected to a servo motor controller 33. The servo motor controller 33 is connected to a controller 34 that controls the peripheral speed of rotation of each of the rolls 2a to 2e on the driven side of the preheating roll.

Further, the controller 34 is connected to a speed detector 35 for detecting the rotation speed of the drive motor, which is the drive source 5 of the drive roll 2f. The controller 34 is provided with speed setting devices 36 for setting the rotation speed of each of the rolls 2a to 2d.

The speed setting device 36 has a memory 37 for storing a preset speed setting value of the speed change roll 2b with respect to the driving roll 2a, a comparator 38,
An ID amplifier 39 is incorporated. Here, memory 3
7, a speed set value corresponding to the absolute speed increase ratio of the speed change roll 2b with respect to the drive side roll 2a is input. When the servo motor 32 is driven, the detection data from the speed detector 35 is input to one input terminal of the comparator 38 of each speed setting device 36 in the controller 34. Further, a speed setting value SV1 of the shift speed of the shift roll 2b with respect to the drive roll 2a is input from the memory 37 to the other input end of the comparator 38.

In this embodiment, the controller 3
4 controls the servo motor 32 based on the detection data output from the speed detector 35 and a preset value of the shift speed of the shift roll 2b with respect to the drive roll 2a,
The cam 9 of the differential gear mechanism 7 is driven by the servo motor 32.
, The flex spline 8 is deformed, and the rotation of the input-side circular spline S of the differential gear mechanism 7 causes the output-side circular spline D to rotate.
The speed of the rotation is changed. Thus, the peripheral speed of rotation between the rolls 2a and 2b is controlled.

The power transmission mechanism between the rolls 2b and 2c, and between the rolls 2c and 2d,
a and the power transmission mechanism 6 between the roll 2b. However, there is no drive source from the roll 2b to the roll 2d, and power is transmitted from the rotating shaft 4 of the roll 2a. Thereby, the peripheral speed of rotation of each of the preheating rolls 2a to 2d is controlled. In some cases, the speed is reduced between 2g and 2j based on the roll 2g.

Next, the operation of the above configuration will be described.
As shown in FIG. 2, the film 3 introduced into the longitudinal stretching machine 1 is transported in the direction of the arrow while being staggered in the order of the rolls 2a to 2j. At this time, the film 3 is preheated (heated) to a predetermined temperature by the preheating rolls 2a to 2d, and after the preheating, is stretched between the rolls 2e and 2f. Further, after stretching, heat setting and cooling treatment are performed by the rolls 2g to 2j, and the stretching is completed.

The film 3 heated by the preheating rolls 2a to 2d elongates and gradually loosens as it travels from the roll 2a to the roll 2d for the above-described reason. In order to prevent the loosening, in the present embodiment, the speed between the rolls 2a to 2d is increased steplessly between the preheating rolls 2a to 2d based on the roll 2a as follows.

That is, in this embodiment, during the operation of the longitudinal stretching machine 1, the detection data output from the speed detector 35 and the speed change roll 2b with respect to the drive roll 2a set in advance.
The servo motor 32 is controlled by the controller 34 on the basis of the set value of the shift speed, and the cam 9 of the differential gear mechanism 7 is operated by the servo motor 32.
The rotation of the output circular spline D is changed relative to the rotation of the input circular spline S of the differential gear mechanism 7 by deforming the flexspline 8. This changes the relative speed between the circular spline S and the flex spline 8 to change the speed of rotation of the output side circular spline S.

The difference in acceleration / deceleration is determined by the difference in the input / output direction of the circular splines S and D of the differential gear mechanism 7 and the difference in the rotation direction of the cam 9; When the rotation direction is the same direction as the S side, the speed is reduced. When the rotation direction of the cam 9 is the same as the D side, the speed is increased.

Therefore, the above configuration has the following effects. That is, in the present embodiment, the servo that directly drives the center shaft 20 of the cam 9 of the differential gear mechanism 7 provided in the power transmission mechanism 6 that transmits the rotation of the driving roll 2a to the driven roll 2b. A motor 32 is provided and a servo motor 3 is provided based on the rotation state of the reference roll 2a.
2 is provided to control the peripheral speed of rotation of each of the driven rolls 2b to 2d by controlling the rotation speed of each of the preheated rolls 2a to 2d. The gear can be shifted easily and with high precision.

Further, in this embodiment, the servo motor 3
2, the center shaft 20 of the cam 9 of the differential gear mechanism 7 is directly driven. Therefore, when the rotation of the cam 9 is operated by a cupless continuously variable transmission, a timing pulley, or the like as in the related art. In comparison, the transmission range can be widened, and the entire transmission can be made compact to reduce the installation space of the entire transmission.

Further, since there is no power transmission by friction unlike the conventional continuously variable cup transmission, there is no slip due to wear. Therefore, the preheating rolls 2a-
The change of the roll peripheral speed of 2d can be controlled.

Further, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0046]

According to the first aspect of the present invention, a drive motor for rotating the drive shaft of the speed change means is provided, and the drive motor is controlled based on the rotation state of the drive side roll to control the rotation of each roll. Since the controller for controlling the peripheral speed is provided, when the roll peripheral speed needs to be changed, the speed can be changed easily and more precisely in a shorter time, and the speed change range can be widened. The entire transmission can be made compact and the installation space of the entire device can be reduced.

According to the second aspect of the present invention, when the differential gear mechanism is operated, the rotation of the drive roll is transmitted to the first internal gear on the input side, and the elliptical shape is disposed inside the elastic ring. The cam is driven by the drive motor to elastically deform the elastic ring and change the meshing state between the external gear and the first internal gear, so that the rotation of the differential gear mechanism on the output side with respect to the rotation on the input side. You can change the speed.

According to the third aspect of the present invention, the detection data output from the speed detector for detecting the rotation speed of the driving roll and the set value of the speed change speed of the driven roll with respect to the driving roll set in advance. The drive motor can be controlled by the controller based on the above.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a main part of a roll peripheral speed control device of a plastic film longitudinal stretching machine according to a first embodiment of the present invention.

FIG. 2 is a front view showing a schematic configuration of the entire longitudinal stretching machine for plastic films.

FIG. 3 is a schematic configuration diagram of a main part of a roll peripheral speed control device of a conventional plastic film longitudinal stretching machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Longitudinal stretching machine 2a Roll based on speed or before speed change 2b Speed change roll 3 Plastic film 6 Power transmission mechanism 7 Differential gear mechanism D Output side circular spline S Input side circular spline 8 Flex spline 9 Cam (transmission means) 32 Servo motor (drive motor) 34 Controller

Continued on front page F term (reference) 3J027 FA36 FB31 GB05 GC07 GC24 GC27 GD03 GD07 GD13 GE01 3J028 EA25 EB35 EB37 EB63 FB05 FC04 FC24 FC32 FC66 FD01 GA25 4F210 AG01 AP08 AR09 QA03 QC02 QG01 QG18 QM15

Claims (3)

[Claims] 1. A plurality of heated rolls are disposed in a conveying path of a plastic film, and a peripheral speed difference is given to the rotation of the rolls to pull the film in a feed direction and to longitudinally stretch the rolls. The power transmission mechanism is provided with a differential gear mechanism having a speed change means, and the rotation of the output side is changed with respect to the rotation of the input side of the differential gear mechanism in accordance with the operation of the speed change means. A roll peripheral speed control device for a longitudinal stretching machine that controls a peripheral speed of rotation of a roll, further comprising: a drive motor that rotationally drives a differential drive shaft of the speed change unit; A roll peripheral speed control device for a vertical stretching machine, further comprising a controller that controls a drive motor to control a peripheral speed of rotation of each roll. 2. The differential gear mechanism, wherein a first internal gear on the input side to which rotation of the roll on the driving side is transmitted, and a number of teeth different from that of the first internal gear are set. 1
A second internal gear coaxially arranged with the internal gear of the second internal gear; and an external gear having the same number of teeth as the second internal gear,
An elastic ring locally meshed with the first internal gear, wherein the speed change means is disposed inside the elastic ring, and elastically deforms the elastic ring to form the external gear and the first internal gear. A roll peripheral speed control device for a longitudinal stretching machine, comprising an elliptical cam for moving a meshing portion with a gear. 3. The controller according to claim 1, wherein the controller is connected to a speed detector for detecting a rotation speed of the drive-side roll, and the detection data output from the speed detector and a preset drive force for the drive-side roll. A roll peripheral speed control device for a longitudinal stretching machine, wherein the drive motor is controlled based on a set value of a shift speed of a side roll.