KR101611397B1 - Method and apparatus for auto-jog of carton processing machine - Google Patents

Abstract

The present invention relates to a method and a device for the auto-jog of a carton former and, more specifically, to a device for the auto-jog of a carton former, capable of manufacturing a carton by attaching or earthing a carbon blank while feeding and transferring the blank. The device includes: a human machine interface unit (HMI) unit (52) reading a specific standard value of the carbon blank, and outputting a control command according to the specific standard value; a digital carrier module (54) applying motor operation power to each corresponding motor (M1, M2, M3,..., Mn) in response to the specific standard value; and encoders (E1, 2, 3,..., n) transmitting motor RPM data of each motor (M1, M2, M3,..., Mn) to the digital carrier module (54). The digital carrier module transmits data, indicating an operation state of each motor (M1, M2, M3, ..., Mn), to the HMI unit (52) based on the motor RPM data from the encoders (E1, 2, 3,..., n), and moreover, the HMI unit (52) is operated to show the operation state of each motor (E1, 2, 3,..., n) to users in response to the data indicating the operation state of each motor (E1, 2, 3,..., n).

Description

[0001] METHOD AND APPARATUS FOR AUTO-JOG OF CARTON PROCESSING MACHINE [0002]

The present invention relates to an auto-jog technique for a carton forming machine, and more particularly to an automatic-jogging machine for automatically operating to improve user convenience of aligning a feeder part and a carrier part of a carton forming device according to a standard of a carton blank to be processed To a carton forming machine auto-jog method and apparatus.

In general, carton is a packing box using paper as a main material and is used to protect and transport various products such as household goods, food, electric and electronic, cosmetics, medicine, beverage, confectionery, liquor, flower, . The carton may be a printing process for printing contents such as photographs and / or characters on a wrapping paper, a coating process for protecting the printing surface, a die for cutting the carton in a developed form (i.e., a carton blank) A die-cutting process, a molding process in which a carton blank is folded and glued to form a three-dimensional box, and the like.

For example, Fig. 1 (a) shows a carton blank 10 as an example. The carton blank 10 of the illustrated example has four side portions 11, 12, 13 and 14 for forming a cube box, a flap surface 15 for bonding, a plurality of bottom surface portions 16 and a plurality of upper surface portions 17 for forming the upper surface of the box. The carton blank 10 is processed by a carton forming machine (see Figs. 2 and 3), thereby forming a carton 10 'shown in Fig. 1 (b). The carton 10 'is formed by applying an adhesive to the flap surface 15 of the carton blank 10 and attaching the flap surface 15 and the first side portion 11 to each other and attaching the side portion 11-14 and the bottom surface portion 16 may be folded to form a closed rock-bottom.

2 is a schematic side view of a carton forming machine 20 for applying a carton blank 10 and folding it into a carton 10 '. The carton forming machine 20 of the illustrated example can be divided into a feeder part 21, a carrier part 23, and a transfer part 25. The feeder part 21 is a part which continuously feeds the carton blanks one by one in accordance with the operation speed in a large amount of loaded carton blank piles. The carrier parts 23 and 24 are formed by performing a folding process and a bonding process on the carton blank supplied one by one from the feeder part 21 to form the carton 10 'as illustrated in FIG. 1 (b) . The transfer part 25 is a part for transferring the manufactured carton 10 'to a subsequent process.

3 is a schematic plan view of the carton forming machine 20 of FIG. In the illustrated example, the feeder part 21 is provided with a feeder 22 composed of a plurality of belts, the carrier part 23 is provided with a carrier belt 24 in which a plurality of belts are arranged side by side, (25) is provided with a transfer carrier (26) composed of a pair of belts parallel to each other.

The carton forming machine 20 having the above-described configuration is configured so as not to process only a single standard paper box but to form cartons of various sizes. For this purpose, it is necessary to arrange the parts of the feeder part 21 and the carrier part 23 according to the respective standards. Therefore, the parts that need to be aligned are typically configured so that the position can be moved by a motor for moving each part. That is, after completing the forming operation for the carton of one standard, the user aligns the feeder part 21 and the carrier part 23 in accordance with the carton standard to be worked in order to perform the carton forming operation of the other standard. The process of aligning the individual components of the carton forming machine according to a specific carton specification is referred to as jogging.

In the jogging process, a user can manually place, for example, a guide for positioning the carton blank disposed on the feeder belt, a grounding part belt, an adhesive applicator, etc. by using an input device provided in the carton forming machine 20 The motor of the component was driven and moved to a specific position.

At this time, the user had to manually press the motor start button to drive each component to a predetermined position according to each standard. Since the moving distance may be short or long, the user has to press the motor driving button for a short time or a long time depending on the moving distance. Further, when the number of parts to be moved is large, there is a problem that the time required for the jogging operation becomes long. As described above, there is a problem that the jogging operation of the carton forming machine is inconvenient to the user and takes a long time.

In order to solve the above problems, according to the present invention, a process of aligning a feeder part and a carrier part of a carton forming device according to a carton blank standard is automatically implemented using an HMI (human machine interface) Jogging method and apparatus of a carton forming machine configured to improve the accuracy of the carton forming machine and to save time for precise adjustment by using stored data.

This object is achieved by an auto-jogging method and apparatus of a carton forming machine provided by embodiments of the present invention.

An auto-jogging method of a carton forming machine provided according to an aspect of the present invention is an auto-jogging method of a carton forming machine for producing a carton by adhering or grounding a carton blank while feeding the carton blank, The controller reading a specific specification value of the carton blank; The controller of the HMI unit transmitting the specific specification value to the control unit of the digital carrier module; Controlling the controller of the digital carrier module to apply the motor driving power to the corresponding motors (M1, M2, M3, ..., Mn) in response to the specific specification value, respectively; The control unit of the digital carrier module receiving motor revolution data from the respective encoders E1, E2, E3, ..., En of the motors M1, M2, M3, ..., Mn; The control unit of the digital carrier module transmits data indicating a driving state of each of the motors M1, M2, M3, ..., Mn to the controller of the HMI unit in response to the motor revolution number data; And the controller of the HMI unit controls the motors (M1, M2, M3, ..., Mn) on the display of the HMI unit in response to data indicating the driving state of each of the motors (M1, M2, M3, ..., Mn). , Mn) to the user.

The step of the controller of the HMI unit reading the specific specification value of the carton blank reads the standard value of the carton blank corresponding to the specific directive from the storage storing in advance as the user inputs a specific directive.

The storage is either a memory device built in the HMI unit, an external storage device insertable into the HMI unit, or a storage device of a remote device connected by the data communication means with the HMI unit.

Wherein the motors (M1, M2, M3, ..., Mn) comprise: a feed positioning device for a carton blank in a feeder part of the carton forming machine; an adhesive application positioning device for a carton blank fed in the feeder part; And a motor for moving the position of the ground positioning device of the carton blank fed from the part.

At least two of the feeding position determining devices of the carton blank in the feeder part of the carton forming machine are side guides for supporting both side parts parallel to the feeding direction of the carton blank, (G1 = G2) with respect to the axis.

Further, an auto-jogging apparatus of a carton forming apparatus provided according to an aspect of the present invention is an auto-jogging apparatus for a carton forming apparatus for producing a carton by bonding or grounding while feeding a carton blank, A human machine interface (HMI) unit for reading and outputting a control command according to the specified specification value; A digital carrier module 54 for controlling the motor driving power to be applied to corresponding motors M1, M2, M3, ..., Mn, respectively, in response to the specific specification value; And an encoder E1, E2, E3, ..., En for transmitting the motor revolution number data of each of the motors M1, M2, M3, ..., Mn to the digital carrier module 54 M2, M3, ..., Mn) to the HMI unit based on the motor revolution number data from the encoders (E1, E2, E3, ..., En) M2, M3, ..., Mn in response to data indicating a driving state of each of the motors (M1, M2, M3, ..., Mn), and the HMI unit transmits data indicating the driving states of the motors M2, M3, ..., Mn) to the user.

According to the present invention, there is provided an automatic-jogging process for automatically aligning a feeder part and a carrier part of a carton forming apparatus according to a standard of a carton blank by using a human machine interface (HMI) Jogging method and apparatus for a carton forming machine configured to improve the productivity of a carton forming machine.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic diagram illustrating a typical carton blank and carton.
2 is a side view illustrating a carton forming machine to which an automatic jogging method and apparatus according to an embodiment of the present invention is applied.
3 is a plan view illustrating the carton forming machine of FIG. 2;
4 is a schematic view illustrating a feeder part and a carrier part of a carton forming machine to which an auto-jogging method and apparatus of a carton forming machine according to an embodiment of the present invention is applied;
5 is a schematic view showing a configuration of an auto-jogging apparatus of a carton forming machine according to an embodiment of the present invention.
6 is a schematic flow chart illustrating a process of an auto-jogging method of a carton forming machine according to an embodiment of the present invention.
7 is a schematic view showing an example of a screen for inputting a specification of a carton blank to be operated on an HMI screen of an auto-jogging apparatus of a carton forming machine according to an embodiment of the present invention.
FIG. 8 is a schematic view showing an example of visually displaying an auto jogging process of a carton blank to be operated on an HMI screen of an auto-jogging apparatus of a carton forming machine according to an embodiment of the present invention; FIG.
9 is a schematic view showing an example of constant-distance control of a side guide of a carton blank in an auto-jog apparatus of a carton forming machine according to an embodiment of the present invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings.

4 is a schematic plan view illustrating a feeder part and a carrier part of a carton forming machine to which an auto-jogging method and apparatus of a carton forming machine according to an embodiment of the present invention is applied.

Referring to Fig. 4, in the illustrated example, the carton blank 40 is disposed on a feeder track (not shown, see Fig. 3). Since the auto-jogging process is performed prior to the carton forming operation, the carton blank 40 can be usually placed on the feeder track.

Although the illustrated example is for explaining the auto-jogging process based on the carton forming machine 20 described in FIGS. 2 and 3, the present invention is not limited to such a carton forming machine alone. In other words, in the illustrated example, it is assumed that the carton forming machine consists of applying a glue to one flap to produce a generally cuboid-shaped carton and then grounding to process the work to make the floor rock bottom. However, it is apparent that the present invention can also be applied to a carton forming machine further including, for example, a grounding in a more complicated form, no bonding process, or another process of forming a cut or cut portion such as a handle hole.

The motor driven by the auto-jogging device of the present invention includes a motor for moving the feeding positioning devices 211, 212, 213, 214 of the carton blank 40 in the feeder part 21 of the carton forming machine 20 . The feeding positioning devices 211, 212, 213 and 214 of the carton blank 40 may include a pair of side guide members 211 and 212 and a pair of front guide members 213 and 214.

The carton blanks 40 are arranged on the feeder belt in a state in which a plurality of carton blanks 40 are laminated and both sides in a direction perpendicular to the direction in which the carton blank 40 advances are supported by a pair of side guide members 211, do. The gap between the side guide members 211 and 212 is arranged by the flap portion 45 and the four side portions 44-41 of the carton blank 40 and is adjusted by the auto jogging process according to the size of the carton blank. The height of the side guide members 211, 212 is equal to or greater than the height of the stack of carton blank sheets stacked one at a time. On the other hand, the pair of front guide members 213, 214 support the bottom of the carton blank 40 in the direction in which the carton blank 40 advances, while at the same time, Only the carton blank 40 is passed to be moved to the carrier part. Since the front guide members 213 and 214 must pass only one carton blank 40 at the bottom, the position is adjusted in the height direction according to the thickness of the carton blank 40.

Although the feed positioning apparatuses 211, 212, 213 and 214 are described as including a pair of side guide members 211 and 212 and a pair of front guide members 213 and 214, It will be appreciated by those skilled in the art that the invention is not limited to this configuration and that various numbers and shapes of guide members are possible.

The motor driven by the auto-jogging device of the present invention also includes a motor for moving the device 230 for determining the position of the flap portion 45 of the carton blank 40, that is, the adhesive application position, can do. The adhesive application position determining device 230 may be omitted in the case of a carton forming machine which does not include a process of applying an adhesive.

The motor driven by the auto-jogging device of the present invention may include a motor for moving the position of the ground positioning devices 242, 243 of the carton blank 40 transferred to the carrier part. The ground positioning devices 242 and 243 have to be moved in position corresponding to the position of the ground line between the four side portions 41, 42, 43 and 44 of the carton blank 40. [ In the illustrated example, the grounding position of the carton blank 40 is determined by the carrier belt 24 consisting of three parallel belts 241, 242, 243. The belt 241 positioned at the center among the three conveyors does not move, and the position of the ground can be determined by moving the left and right belts 242 and 243.

5 is a schematic view showing a configuration of an auto-jogging apparatus of a carton forming machine according to an embodiment of the present invention.

The carton forming machine is a device for producing a carton by feeding a carton blank and bonding or grounding the carton while conveying it. The auto-jogging device 50 adjusts the position of the parts of the carton forming machine so as to process the specifications of the changed carton when the specifications of the carton processed by the carton forming machine change. 5, the auto-jogging device 50 of the carton forming machine includes an HMI unit 52, a digital carrier module 54, and motor encoders E1, E2, E3, ..., En).

The human machine interface (HMI) unit 52 is a control console that reads a specific specification value of the carton blank and outputs a control command according to the specification value. The HMI unit 52 may be configured to include a controller 523, a storage 521, an input unit 525, and a display 527.

The storage 521 is a memory device that stores the standard value of the carton blank in advance. The storage 521 may be a memory device such as a hard disk, a flash memory, a RAM, or the like, which is built on the HMI unit 52. [ The storage 521 may also be a device detachably connected to the HMI unit 52, such as a portable memory device such as a USB memory device. Further, the storage 521 may be a memory device included in a computer device connected by various data communication means such as Bluetooth, LAN, or the Internet.

The input unit 525 is a device such as a keyboard, a touch panel, a touch screen, or the like that allows a user to directly input a specification value of a carton blank to the HMI unit 52 or input a model name / job name of a carton blank to be operated .

The display 527 is a visual display device for displaying the contents to be processed by the HMI unit 52 so that the user can visually recognize the contents, and may be a device such as an LED monitor, a touch screen, or the like.

The controller 523 reads the specific standard value stored by the user or stored in the storage, and then transmits the digital standard data to the digital carrier module 54 to control the auto jog operation of the carton forming machine based on, for example, the RS 485 communication method. Lt; / RTI > The controller 523 then receives result data relating to the control operation from the digital carrier module 54 and may display the work progress to the user via the display 527 as a result.

The digital carrier module 54 has a control section 541 and a relay set 543. [ The control unit 541 responds to the specific standard value received from the HMI unit 52 to output the motor driving power that may be a three-phase alternating current power of, for example, 220 V to the corresponding motor M1, M2, M3, Respectively. The control unit 541 can receive the motor revolution data from the encoders E1, E2, E3, ..., En that sense the number of revolutions of the motors M1, M2, M3, have. The received motor speed data can be converted into the moving distance of the component driven by each motor, and such moving distance data can be transmitted to the HMI unit 52 as data indicating the driving state of the motor.

The motor set 56 controlled by the digital carrier module 54 includes motors M1, M2, M3, ..., Mn driven in an auto-jogging process. Each of the motors is provided with corresponding encoders E1, E2, E3, ..., En. Each of the encoders transmits the motor revolution number data to the digital carrier module 54.

6 is a schematic flow chart showing a process of an auto-jogging method of a carton forming machine according to an embodiment of the present invention.

Referring to FIG. 6, when using the master-slave communication protocol in the illustrated example, the HMI unit 52 operates as a master device (MS) and the digital carrier module 54 operates as a slave (SL).

First, for the auto-jog operation, the user can input data such as flap dimensions, length and width dimensions of the carton blank to be worked, stop margin, job name, and the like. Or, by calling an existing job name, data such as flap dimensions, length and width dimensions, stop margin, job name, etc., which are stored in advance, can be recalled. Then, the user can input a start command by pressing the start button, for example, in the HMI unit 52. [ The HMI unit 52 then sends 610 the current work dimension value to the digital carrier module 54 to check the motor.

In response, the digital carrier module 54 controls the relays R1, R2, R3, ..., Rn of the relay set 543 to correspondingly drive the motors. Each relay is a kind of switch device connected to provide motor drive power to each motor. The digital carrier module 54 can receive the data indicating the driving state of each motor from the motor set 56 and then forward it to the HMI unit 52 (630). Above 610 and 630 are initial routines that can be used for motor checking.

After the motor check is completed, the user can perform 650 the respective operations by pressing the home return, start, stop, finish, save (SAVE) command buttons in the HMI unit 52. Here, the home return instruction is an instruction for causing the alignment devices to move to the origin position. The start command is an instruction to start the auto-jog operation according to the set Carton blank specification value. The stop command is an instruction to stop driving the motor at the current position. The completion command is an instruction to finish the current auto-jog operation. On the other hand, the save command is a command to store the resultant data on the storage device.

HMI unit 52 then sends each command to digital carrier module 54. [ In response, the digital carrier module 54 can acknowledge by receiving the data indicative of the driving state of the motor from the encoder of the motor after controlling the motors, and then transmitting the result to the HMI unit 52 670).

7 is a schematic view showing an example of a screen for inputting a specification of a carton blank to be operated on an HMI screen of an auto-jogging apparatus of a carton forming apparatus according to an embodiment of the present invention.

Referring to FIG. 7, a screen 70 is displayed on the touch screen (input unit and display) of the HMI unit for directly inputting a standard value of a carton blank to be currently operated or inputting a job name. Also shown is an example in which buttons for starting, ending, stopping, referencing, and issuing a SAVE command are displayed. The user has to measure the width of the flap FLAP (i.e., the side to which the adhesive is applied) is 20 mm, the length of the length (i.e., width of the larger one of the side portions) is 250 mm, Width) is 220 mm, and the stop margin is 3 pulses. Alternatively, the user can retrieve a pre-stored dimension value associated with the job name by entering the job name. In the illustrated example, the job name is 'Ace 101', and it can be seen that data stored on the USB or SRAM, which is a storage, can be retrieved by using the job name.

8 is a schematic view showing an example of visually displaying an auto jogging process of a carton blank to be operated on an HMI screen of an auto-jogging apparatus of a carton forming machine according to an embodiment of the present invention.

The screen 80 shown in FIG. 8 shows the location of auto-aligned devices to be visualized and displayed to the user until the auto-jogging operation is initiated and completed. That is, the distance by which the motors (M1, M2, M3, M4) for moving the guide members are moved is represented by numerals as 7.5, and the motor M7 similarly moves the adhesive positioning devices, And the motors M5 and M6 for moving the carrier positioning device are indicated as being moved by 5, respectively. The contents of the screen are not limited to those shown in the drawings, and it is obvious that various modifications can be made if the contents are visualized to such an extent that the user can intuitively understand them easily.

9 is a schematic view showing an example of constant-distance control of a side guide of a carton blank in an auto-jogging apparatus of a carton forming machine according to an embodiment of the present invention.

A pair of side guide members 211 and 212 for supporting both sides of the carton blank 40 in the feeder part of the carton forming machine according to the present invention are disposed at equal intervals G1 = G2), that is, an equally spaced control feature is shown.

4, a plurality of carton blanks 40 are arranged on the feeder belt in a stacked state, and both side surfaces in a direction perpendicular to the direction in which the carton blank 40 advances are disposed on a pair of side surfaces And are supported by the guide members 211 and 212. The size of the carton blank 40 varies depending on the standard. Therefore, when arranging the carton blanks 40 of different sizes in the feeder part, it is always necessary to align them with respect to the same position.

In order to meet this need, according to the present invention, the side guide members 211 and 212, which support the carton blank 40 on both sides of the carton blank 40, are controlled at equal intervals with respect to the central axis of the overall working flow direction of the carton- . 9, the center axis 90 corresponds to the center axis of the carton forming machine, G1 is the distance between the center shaft 90 and the left side guide member 212, G2 is the distance between the center shaft 90 and the right side guide And the distance between the members 211.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. In addition, those skilled in the art will appreciate that many modifications and variations of the present invention are possible without departing from the spirit and scope of the appended claims. Accordingly, all such appropriate modifications and changes, and equivalents thereof, should be regarded as within the scope of the present invention.

10, 40: Carton blank
20: Carton forming machine
50: auto-jog device
52: HMI unit
521: Storage
523: Controller
525:
527: Display
54: Digital Carrier Module
541:
543: Relay set
56: Motor set

Claims (10)

An auto-jogging method of a carton forming machine for producing a carton by feeding a carton blank and bonding or grounding the carton while conveying,
The controller 523 of the human machine interface (HMI) unit 52 reads from the storage 521 storing the specification value of the carton blank corresponding to the specific directive in advance as the user inputs a specific directive;
The controller 523 of the HMI unit 52 transmits the specific specification value to the control unit 541 of the digital carrier module 54;
Controlling the controller 541 of the digital carrier module 54 to apply the motor driving power to the corresponding motors M1, M2, M3, ..., Mn according to the specified specification value, respectively;
The controller 541 of the digital carrier module 54 outputs the motor revolution number data from the encoders E1, E2, E3, ..., En of the motors M1, M2, M3, ..., Receiving;
The controller 541 of the digital carrier module 54 sends a command to the controller 523 of the HMI unit 52 in response to the motor rotational speed data of each of the motors M1, M2, M3, Transmitting data indicating a driving state; And
The controller 523 of the HMI unit 52 responds to the data indicative of the driving state of each of the motors M1, M2, M3, ..., Mn by the display 527 of the HMI unit 52 The step of displaying the driving status of each of the motors M1, M2, M3, ..., Mn to the user
The method of auto-jogging a carton forming machine according to claim 1, delete The method according to claim 1,
The storage 521
A memory device built in the HMI unit 52, an external storage device insertable into the HMI unit 52, or a storage device of a remote device connected to the HMI unit 52 by data communication means Wherein the auto-jogging method comprises the steps of: The method according to claim 1,
The motors (M1, M2, M3, ..., Mn)
The feeding position determining devices 211, 212, 213 and 214 of the carton blank 40 in the feeder part 21 of the carton forming machine 20 and the adhesive application of the carton blank 40 fed in the feeder part 21 And a motor for moving the position of the positioning device (230) and the ground positioning devices (242, 243) of the carton blank (40) fed by the feeder part (21) Auto-jog method. 5. The method of claim 4,
At least two of the feeding positioning devices 211, 212, 213 and 214 of the carton blank 40 in the feeder part 21 of the carton forming machine 20 are parallel to the feeding direction of the carton blank 40 Side guides 211 and 212 for supporting both side portions, respectively,
Wherein the side guides (211, 212) supporting the both side portions are controlled to have the same gap (G1 = G2) with respect to the center shaft (90). An auto-jogging apparatus for a carton forming machine for producing a carton by feeding a carton blank and bonding or grounding the carton while conveying,
A human machine interface (HMI) unit 52 for reading a specific specification value of a carton blank stored in advance in the storage 521 and outputting a control command according to the specified specification value;
A digital carrier module 54 for controlling the motor driving power to be applied to corresponding motors M1, M2, M3, ..., Mn, respectively, in response to the specific specification value; And
E2, E3, ..., En) for transmitting the motor revolution number data of each of the motors (M1, M2, M3, ..., Mn) to the digital carrier module
Including,
The digital carrier module 54 instructs the HMI unit 52 based on the motor revolution number data from the encoders E1, E2, E3, ..., En. ..., Mn), and also transmits data
The HMI unit 52 is connected to the motors M1, M2, M3, ..., Mn in the HMI unit 52 in response to data indicating the respective driving states of the motors M1, M2, M3, 0.0 > Mn < / RTI >
Wherein the auto-jogging device of the carton forming machine is characterized in that the auto-jogging device of the carton forming machine. delete The method according to claim 6,
The storage 521
A memory device built in the HMI unit 52, an external storage device insertable into the HMI unit 52, or a storage device of a remote device connected to the HMI unit 52 by data communication means Wherein the auto-jogging device of the carton forming machine is characterized in that the auto-jogging device of the carton forming machine. The method according to claim 6,
The motors (M1, M2, M3, ..., Mn)
The feeding position determining devices 211, 212, 213 and 214 of the carton blank 40 in the feeder part 21 of the carton forming machine 20 and the adhesive application of the carton blank 40 fed in the feeder part 21 And a motor for moving the position of the positioning device (230) and the ground positioning devices (242, 243) of the carton blank (40) fed by the feeder part (21) Auto-jog device. 10. The method of claim 9,
At least two of the feeding positioning devices 211, 212, 213 and 214 of the carton blank 40 in the feeder part 21 of the carton forming machine 20 are parallel to the feeding direction of the carton blank 40 Side guides 211 and 212 for supporting both side portions, respectively,
Wherein the side guides (211, 212) supporting the both side portions are controlled to have the same gap (G1 = G2) with respect to the center shaft (90).

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