TWI720691B - Work holding apparatus, printing system and printing method - Google Patents

Abstract

When the workpiece holding device of the present invention prints on the side surface of a workpiece such as a glass or plastic container, bottle, etc., which has a shape that is rotationally symmetric about the axis of rotation symmetry, it supports the workpiece well regardless of the type of the workpiece. It is held freely rotatably around the axis of rotational symmetry, and the side surface of the workpiece can be printed well. The workpiece holding device of the present invention includes: a holding body part; a first holding part that rotatably holds one end of the workpiece in the axial direction of the rotational symmetry axis with respect to the holding body part; and a second holding part that aligns the shaft The other end of the upward work piece is rotatably held with respect to the holding body; the first holding section holds one end of the work piece via the self-aligning bearing.

Description

Workpiece holding device, printing system and printing method

The present invention relates to a holding technology for printing on the side surface of a work piece such as a glass container or a plastic container having a shape that is rotationally symmetrical about the rotational symmetry axis, and the work piece is rotatably held around the rotational symmetry axis.

The descriptions, drawings, and disclosures in the scope of the patent application shown in the following Japanese applications are incorporated herein by reference in their entirety.

Japanese Patent Application No. 2018-223534 (filed on November 29, 2018).

For example, with regard to containers and bottles made of glass or plastic that contain high-value-added products such as cosmetics, it has been desired to perform high-quality printing on the sides of the containers and the like in recent years. In order to meet this demand, for containers such as glass containers, plastic containers, etc. (corresponding to an example of the "workpiece" of the present invention) that have a rotationally symmetrical shape around the axis of rotational symmetry, it is disclosed that the side surface of the work piece by intaglio printing (The body of the container) for high-precision printing. That is, an ink is filled in a gravure in a printing device to form an ink pattern, and the surface of a cylindrical blanket layer roller receives the ink pattern. Then, while making the side surface of the workpiece abut against the blanket layer roller carrying the ink pattern in the printing device, while rotating the workpiece around the rotational symmetry axis, the ink pattern on the blanket layer roller is transferred to the workpiece. In addition, the workpiece is moved between a plurality of different printing devices to make a plurality of layers The ink patterns overlap each other on the side of the workpiece, thereby realizing multi-color printing.

Here, when the ink pattern is transferred to the workpiece, the workpiece must be rotatably held around the axis of rotational symmetry. Therefore, it can be considered to use a mandrel as described in, for example, International Publication No. 2009/044569 or Japanese Patent Laid-Open No. 2009-101605.

However, the mandrel is inserted into the workpiece from one side of the workpiece in the axial direction of the rotational symmetry axis to support the workpiece from the inside. Therefore, there are cases where the mandrel cannot be used depending on the type of the workpiece. Furthermore, even if a mandrel can be used, in order to perform the above transfer process well, the side surface of the work must be strongly pressed against the blanket layer roller. At this time, the mandrel is inserted into the workpiece in a so-called cantilever state to support the workpiece from the inside. Therefore, there is a difference in the force supporting the workpiece between the front end side and the rear end side of the mandrel, which makes it difficult to evenly press the side surface of the workpiece. In the case of blanket rolls. In addition, it is desirable to transfer the ink pattern to the shoulder of the workpiece, but in order to further satisfy this demand, it is necessary to increase the pressing force. However, in a mandrel supported in a cantilever state, there is also a problem that sufficient pressure resistance cannot be obtained.

The present invention has been accomplished in view of the above-mentioned problems, and its object is to provide a workpiece holding device, a printing system and a printing method that can use the workpiece holding device to print on the side of the workpiece, and the workpiece holding device is rotated around the workpiece. When printing on the side of a work piece such as a glass or plastic container or bottle with a rotationally symmetrical axis of symmetry, regardless of the type of work, the work can be well supported and held rotatably around the rotational symmetry axis.

The first aspect of the present invention is a workpiece holding device that relatively presses a printing device to a workpiece having a shape that is rotationally symmetric about an axis of rotational symmetry When printing on the side surface, the workpiece is rotatably held around the axis of rotational symmetry. It is characterized in that it is provided with: a holding body portion; a first holding portion that opposes one end of the workpiece in the axial direction of the rotational symmetry axis The holding body is rotatably held; and a second holding part that rotatably holds the other end of the workpiece in the axial direction relative to the holding body; the first holding part holds one end of the workpiece via a self-aligning bearing.

In addition, a second aspect of the present invention is a printing system that prints on the side surface of a workpiece having a shape that is rotationally symmetric about an axis of rotational symmetry, and is characterized in that it is provided with: the above-mentioned workpiece holding device; first A printing device that prints a first printing pattern on the side surface of the workpiece held by the workpiece holding device; a second printing device that prints a second printing pattern on the side surface of the workpiece held by the workpiece holding device; and a conveying device in The workpiece holding device holding the workpiece is transported between the first printing device and the second printing device.

Furthermore, a third aspect of the present invention is a printing method, characterized in that it includes the following steps: a step of holding a workpiece having a shape that is rotationally symmetric about the axis of rotation symmetry by the workpiece holding device; The sequence of the device and the second printing device conveys the workpiece holding device holding the workpiece; the first printing device prints the first printing on the side surface of the workpiece held by the workpiece holding device that is conveyed to the first printing device The step of patterning; and the step of printing the second printing pattern by the second printing device on the side surface of the workpiece held by the workpiece holding device that is transported from the first printing device to the second printing device.

In the invention thus constituted, one end portion and the other end portion of the workpiece in the axial direction of the rotational symmetry axis are rotatably held by the first holding portion and the second holding portion, respectively. Therefore, the workpiece is held well by the workpiece holding device. Therefore, when the printing device is used to print on the side of the workpiece, the printing device is relatively firmly pressed to the workpiece. Perform printing on the side of the workpiece in the state of the side of the workpiece. In addition, even if the axis of rotational symmetry is slightly offset due to individual differences in the workpiece, the self-aligning bearing will absorb the offset of the axis of rotational symmetry, so that the workpiece can rotate stably.

As described above, according to the present invention, regardless of the type of workpiece having a shape that is rotationally symmetric about the rotational symmetry axis, the workpiece can be held rotatably around the rotational symmetry axis, and the side surface of the workpiece can be printed well.

The above-mentioned various aspects of the present invention have multiple components that are not essential. In order to solve part or all of the above-mentioned problems, or to achieve part or all of the effects described in the specification, part of the above-mentioned plural components may be added. The constituent elements are appropriately changed, deleted, replaced with other new constituent elements, and part of the limited content is deleted. In addition, in order to solve part or all of the above-mentioned problems, or to achieve part or all of the effects described in the specification, part or all of the technical features included in one aspect of the present invention may also be combined with the above-mentioned present invention. A combination of part or all of the technical features contained in other aspects is regarded as an independent aspect of the present invention.

1: Edition platform unit

2: Ink filling unit

3: Transfer unit

4: Temporary hardening unit

11: Platform

12: Calibration agency

13: Base

14: Rail

15: Calibrate the camera

21: Nozzle

22: Ink supply department

23: Scraper

30: Blanket layer roller

31: Blanket layer carcass

32: blanket layer

33: Motor

100: printing system

101: The first printing device

102: The second printing device

200: Formal hardening device

300: Bottle holding device

310: The first holding part

311, 321: Shaft

312: Self-aligning bearing

313: Mouth retaining member

314, 324: gripping member

320: second holding part

322: Bottom holding member

323: Spring member

330: Keep the body part

331: The first support part

332: The second support part

333: Abutment

340: Rotary drive unit

341: Motor (drive source)

342: Power Transmission Mechanism

343a, 343b: gears

344a: (1st) Pulley

344b: (2nd) Pulley

344c: (3rd) Pulley

345: Loop belt

346: Clutch

347: Swing member

348: Spring member (forcing member)

351, 353, 354: (1st) spare roll

352, 355, 356: (2nd) spare roll

400: Bottle conveying device

900: control device

AR: rotational symmetry axis

B: Bottle (workpiece)

Ba: (of the bottle) side

Bb: (of the bottle) carcass

Bc: (of the bottle) rim

Bd: (of the bottle) male thread

Be: (of the bottle) bottom

P: version

R: direction

X: axial

Y: compression direction

Z: Vertical direction

Fig. 1 is a schematic diagram showing a schematic configuration example of a printing system for printing the side surface of a workpiece using the first embodiment of the workpiece holding device of the present invention.

Figure 2 is a diagram showing the composition of the plate platform unit and the ink filling unit.

Fig. 3 is a diagram showing the structure of a bottle holding device and a bottle held by the bottle holding device.

Fig. 4 is a perspective view schematically showing the structure of the rotation driving part equipped in the bottle holding device.

Fig. 5 is a side view of the bottle holding device shown in Fig. 3.

6(a) to (d) are graphs showing the eccentricity characteristics of the bottle when the bottle holder shown in FIG. 3 is rotated.

Fig. 7 is a diagram showing a second embodiment of the work holding device of the present invention.

Fig. 8 is a diagram showing a third embodiment of the work holding device of the present invention.

Fig. 1 is a schematic diagram showing a schematic configuration example of a printing system for printing the side surface of a workpiece using the first embodiment of the workpiece holding device of the present invention. The printing system 100 is used for articles having a shape that is rotationally symmetrical about a rotational symmetry axis (symbol AR in FIG. 3) such as glass containers or bottles, resin containers or bottles (hereinafter, these are collectively referred to as A system for printing on the side Ba of "Bottle B"). Bottle B corresponds to an example of the "workpiece" of the present invention, and the bottle holding device for holding the bottle B corresponds to an example of the "workpiece holding device" of the present invention. Here, in order to uniformly show the directions in each figure, the XYZ orthogonal coordinate system is set as shown in FIG. 1. For example, the XY plane can be regarded as a horizontal plane, and the Z axis can be regarded as a vertical axis. Hereinafter, let the (-Z) direction be the vertical downward direction. In addition, in each of the following figures, the dotted arrow marked near the component element indicates the operation of the component element.

The printing system 100 is provided with two sets of printing devices, namely, a first printing device 101 and a second printing device 102 that print on the side Ba of the bottle B with one ink color. Therefore, the printing system 100 can perform two-color printing on the side Ba of the bottle B. Furthermore, it may be configured as a monochrome printing system with one set of printing devices or a multi-color printing system with three or more sets of printing devices.

The first printing device 101 and the second printing device 102 include a plate platform unit 1, an ink filling unit 2, a transfer unit 3, and a temporary curing unit 4, respectively. Its wait The units are arranged in the above order from the (-Y) direction side to the (+Y) direction side. In addition, a main curing device 200 is installed in the vicinity of the second printing device 102. The bottle B is held between the first printing device 101, the second printing device 102, the main curing device 200, and the bottle loading and unloading table (not shown) by the bottle conveying device 400 while being held by the bottle holding device 300 It is transported circularly. Furthermore, in this embodiment, the installation and removal of the bottle B with respect to the bottle holding device 300 is performed by the operator's manual operation at the above-mentioned bottle loading and unloading station. On the other hand, in order to automate other tasks, the printing system 100 is further provided with a control device 900 that controls the actions of its various units.

As described below, the first printing device 101 and the second printing device 102 have the same configuration and perform the same operations. In addition, the structure and operation of the bottle holding device 300 will be described in detail below.

The printing process of the printing system 100 is performed by using the printing devices 101 and 102 to perform the monochrome printing operations including the following steps (1), (2), (3), and (4), and then perform the following steps (5) And complete, i.e.,

(1) Using the plate platform unit 1 and the ink filling unit 2 to form an ink pattern using photocurable ink;

(2) Transfer the ink pattern to the transfer unit 3;

(3) Transfer the ink pattern from the transfer unit 3 to the side Ba of the bottle B;

(4) The ink is temporarily hardened by light from the temporary hardening unit 4;

(5) The ink is fully cured by the actual curing device 200.

More specifically, the bottle B is loaded and unloaded to the bottle holding device 300 by the operator's manual operation at the bottle loading and unloading station. That is, after the printed bottle B is removed from the bottle holding device 300, the bottle B to be printed is installed in the bottle holding device 300. The bottle B thus installed is rotatably held by the bottle holding device 300 around the axis of rotational symmetry. In this state, it is transported to the first printing device 101 by the bottle transport device 400 integrally with the bottle holding device 300. In the first printing device 101, the steps (1) to (4) above are performed on the bottle B in a state where the bottle B is rotatably held by the bottle holding device 300. After that, the bottle holding device 300 holding the bottle B is transported from the first printing device 101 to the second printing device 102.

Figure 2 is a diagram showing the composition of the plate platform unit and the ink filling unit. The plate platform unit 1 includes a platform 11 on which a plate (for example, an intaglio plate) P for forming an ink pattern is placed on the upper surface. The platform 11 is attached to the base portion 13 via the calibration mechanism 12. The calibration mechanism 12 moves the platform 11 in the XYZ direction and the rotation direction around the Z axis in accordance with the control command from the control device 900. For example, a cross-roller bearing mechanism can be used as the calibration mechanism 12.

The base portion 13 is engaged with a guide rail 14 extending along the Y direction on the pedestal of the printing system 100 and can move back and forth in the Y direction along the guide rail 14. More specifically, a driving mechanism (not shown) controlled by the control device 900 is connected to the base portion 13, and the base portion 13 moves in the (-Y) direction and the (+Y) direction by the actuation of the driving mechanism . The position closest to the (-Y) direction side in the movable range of the base portion 13 (the position indicated by the solid line in FIG. 2) is the starting position of the base portion 13.

Calibration cameras 15 and 15 are arranged above the platform 11 in the state of being positioned at the initial position. The calibration cameras 15 and 15 photograph the calibration marks provided on the periphery of the plate P or the upper surface of the plate P placed on the platform 11 and send the image data to the control device 900. The control device 900 detects the position of the plate P on the platform 11, and if necessary, causes the calibration mechanism 12 to operate, thereby adjusting the position of the plate P to an appropriate position.

Set along the path that the base 13 moves in the (+Y) direction from the starting position An ink filling unit 2 and a transfer unit 3 are provided. The ink filling unit 2 is provided with a nozzle 21 opposed to the upper surface of the plate P placed on the platform 11 directly below. The ink supply unit 22 controlled by the control device 900 supplies the nozzle 21 with photocurable ink (hereinafter, abbreviated as “ink” in some cases). The supplied ink is discharged from a discharge port provided at the lower end of the nozzle 21, and is applied to the upper surface of the plate P.

The photocurable ink contains a pigment as a color developer, a polymer material (including at least one of a monomer and an oligomer) that forms a strong polymer layer by polymerization, and the use of A photopolymerization initiator that promotes the polymerization reaction of polymer materials by reactive species generated by causing chemical changes.

A scraper 23 is provided on the (+Y) direction side of the nozzle 21. The squeegee 23 slidably rubs on the surface of the plate P supplied with the ink to scrape the ink. Thereby, on the one hand, the ink is filled in the recesses provided on the upper surface of the plate P, and on the other hand, the remaining ink is removed to form an ink pattern.

The plate P filled with ink in this way moves in the (+Y) direction and reaches the arrangement position of the transfer unit 3. As shown in FIGS. 1 and 2, the transfer unit 3 includes a blanket-shaped layer roller 30 and a motor 33 that rotates it. In more detail, the blanket layer roller 30 includes, for example, a cylindrical blanket layer carcass 31 made of metal and a blanket layer 32 wound on the surface thereof, and has a substantially cylindrical shape as a whole. The blanket layer roller 30 is rotatably supported by a frame not shown in the figure, and is driven to rotate around a central axis represented by a dotted chain line in FIG. 1 by a motor 33 controlled by the control device 900.

The blanket layer 32 is made of elastic resin material, such as silicone resin, and can carry ink patterns on its surface. The blanket layer 32 has a thickness sufficiently larger than the unevenness that can be produced on the side Ba of the bottle B, that is, the surface of the bottle B. As shown in Figure 2, when the plate P placed on the platform 11 passes through the position directly below the blanket layer roller 30, the surface of the blanket layer 32 Abutting on the upper surface of the plate P. At this time, the ink filled in the recesses of the plate P is transferred to the surface of the carpet layer 32. The ink pattern on this plate P. Accepted by blanket layer 32

In this way, the ink pattern temporarily accepted by the carpet layer 32 (primary transfer) is secondarily transferred to the side Ba of the final bottle B, that is, the surface of the bottle B. In this way, the blanket layer 32 functions as an intermediate transfer body that temporarily supports the ink pattern that is finally transferred to the side surface Ba of the bottle B. Furthermore, in this embodiment, two printing devices 101 and 102 are equipped to form two types of ink patterns, but the ink patterns formed by the printing devices 101 and 102 correspond to the "first printing pattern" and An example of "the second print pattern".

Fig. 3 is a diagram showing the structure of a bottle holding device and a bottle held by the bottle holding device. As shown in the figure, the bottle holding device 300 can hold the bottle B with the bottle cap (not shown) removed. The bottle B is formed of, for example, a resin material or a glass material whose main material is polyethylene terephthalate (PET), and has a shape that is rotationally symmetric about the axis of rotational symmetry AR. In this embodiment, the body part Bb of the bottle B is processed to form a cylindrical shape, and the surface of the body part Bb, that is, the side surface Ba of the bottle B, is printed with two kinds of ink patterns superimposed. In addition, beverages such as water, tea, juice, etc. or cosmetics can be stored inside the bottle B. In the bottle B, a rim portion Bc is formed on one side of the axis X of the rotational symmetry axis AR, that is, on the side in the (+X) direction. Here, the mouth edge portion Bc is a mouth edge portion roughly where the bottle cap is attached from the shoulder portion of the body portion Bb. On the one hand, an opening is provided on the (+X) direction end surface of the mouth edge portion Bc, and on the other hand, a male screw portion Bd is appropriately formed in the (-X) direction from the vicinity of the opening. The rim portion Bc and the bottom portion Be of the bottle B formed in this way are held by the first holding portion 310 and the second holding portion 320 of the bottle holding device 300, respectively, and the bottle B is freely rotatable about the rotational symmetry axis AR in a lateral posture The ground is held and then rotated appropriately.

The bottle holding device 300 has a holding body part 330 that rotatably holds the bottle B via the first holding part 310 and the second holding part 320. The holding body portion 330 has a flat base 333, a first support portion 331, and a second support portion 332. The first support portion 331 is erected upward from the base 333 on the (+X) direction side. In addition, the second support portion 332 is spaced in the (-X) direction from the first support portion 331 and is erected upward from the base 333 at an interval that is only slightly wider than the height of the bottle B (equivalent to the dimension in the X direction in FIG. 3) Set up.

The first holding portion 310 has a shaft 311 extending in the X direction. The shaft 311 is rotatably supported with respect to the first support portion 331, and a flange holding member 313 is attached to the end of the shaft 311 in the (−X) direction via a self-aligning bearing 312. A female screw part is formed on the inner side of the lip holding member 313. Therefore, when the operator holds the bottle B while restricting the rotation of the bottle B, while facing the gripping member 314 installed at the end of the shaft 311 in the (+X) direction to rotate, the edge holding member 313 is set The male screw part Bd of the lip part Bc is screwed and connected to the bottle B in the horizontal posture. Conversely, the operator restricts the rotation of the bottle B while rotating the gripping member 314 to the opposite side, so that the edge holding member 313 can be removed from the bottle B. In addition, the holding form of the mouth edge portion Bc by the mouth edge holding member 313 is not limited to the above-mentioned screw structure, and for example, a clamping structure gripped by a plurality of holding members may be adopted.

On the other hand, the second holding portion 320 has a shaft 321 extending in the X direction. The shaft 321 is rotatably supported with respect to the second support portion 332 in a state where it is arranged to coincide with the axis of the shaft 311. In addition, a bottom holding member 322 that is processed into a shape capable of engaging with the bottom Be of the bottle B is attached to the end of the shaft 321 in the (+X) direction. A spring member 323 is movably inserted into the shaft 321 between the bottom holding member 322 and the (+X) side wall surface of the second support portion 332 to urge the bottom holding member 322 toward the bottom Be of the bottle B. Therefore, as shown in Figure 3, the bottle B is arranged in a horizontal position, and the bottom is protected The holding member 322 applies force to the bottom Be of the bottle B and holds it in a state where the edge holding member 313 is connected to the edge portion Bc, whereby the rotational symmetry axis AR of the bottle B is substantially aligned with the axis of the shafts 311 and 321. Bottle B rotates freely around the rotational symmetry axis AR. On the other hand, the operator can pull the gripping member 324 installed at the (-X) direction end of the shaft 321 toward the (-X) direction by resisting the force of the spring member 323, so that the bottom can be held. The member 322 leaves the bottom Be of the bottle B, so that the bottle B is unloaded.

In this way, in the bottle holding device 300, the first holding portion 310 and the second holding portion 320 hold the bottle B rotatably around the rotational symmetry axis AR, but the rotation driving portion 340 may be further provided on the first support portion 331 , The shaft 311 is rotationally driven to rotate the bottle B. Hereinafter, the structure and operation of the rotation driving unit 340 will be described in detail with reference to FIGS. 3 and 4.

Fig. 4 is a perspective view schematically showing the structure of the rotation driving part equipped in the bottle holding device. The rotation driving portion 340 uses the motor 341 fixed to the first support portion 331 as the "drive source" of the present invention, and appropriately applies the rotation driving force generated by the motor 341 to the shaft 311 via the power transmission mechanism 342. Bottle B rotates around the axis of rotational symmetry AR. The power transmission mechanism 342 has two gears 343a and 343b, three pulleys 344a to 344c, an endless belt 345 spanned between the pulleys 344a to 344c, and a clutch 346. The gear 343a is mounted on the rotating shaft of the motor 341. The gear 343b is toothed to the gear 343a, and the pulley 344a is connected to the gear 343b via the clutch 346. In addition, the pulley 344a is connected to the pulleys 344b and 344c by an endless belt 345. Among them, the pulley 344b is attached to the shaft 311, and the pulley 344c is attached to the swing member 347. The swing member 347 receives the urging force generated by the spring member 348 and is urged in the direction R away from the pulleys 344a and 344b. In this way, the pulley 344c is set to be displaceable relative to the pulleys 344a and 344b, as The so-called tension pulley functions, and the endless belt 345 is spanned between the pulleys 344a to 344c, and receives tension along with the displacement of the pulley 344c. Therefore, when the clutch 346 is switched to the ON state in accordance with the transmission command from the control device 900, the pulley 344a and the gear 343b rotate together to perform power transmission to the shaft 311. As a result, the bottle B is rotationally driven around the rotational symmetry axis AR. On the other hand, when the clutch 346 is switched to the OFF state, the aforementioned power transmission is blocked. As a result, the bottle B is maintained in a freely rotatable state around the rotational symmetry axis AR, and when the ink pattern is transferred from the blanket layer 32, the bottle B can be rotated following the movement of the blanket layer 32.

In this way, the bottle B is rotated and driven in a lateral position by the rotation driving part 340, or is driven to rotate relative to the blanket layer 32, but in order to assist in supporting the bottle B and stabilize the position of the bottle B, the bottle holding device 300 is shown in FIG. It shows that there are two backup rollers 351 and 352.

Fig. 5 is a side view of the bottle holding device shown in Fig. 3. The backup rollers 351 and 352 have a shaft structure with the X direction as the axial direction, and are rotatably supported with respect to the first support portion 331 and the second support portion 332. Wherein, the backup roller 351 is in the pressing direction Y in which the side Ba of the bottle B is pressed against the blanket layer 32 of the printing devices 101 and 102, and is arranged on the opposite side of the blanket layer 32 via the bottle B, that is (+Y) Direction side. The displacement of the bottle B in the (+Y) direction is restricted by the backup roller 351 abutting on the side surface of the bottle B in the (+Y) direction.

In addition, the other backup roller 352 is arranged at a position lower than the backup roller 351 in the vertical direction Z. The backup roller 352 abuts against the side Ba of the bottle B from below to restrict the displacement of the bottle B in the direction of gravity, that is, the (-Z) direction. In this way, in this embodiment, the backup rollers 351 and 352 respectively function as the "first backup member" and the "second backup member" of the present invention.

In the printing system 100 constructed in this way, the bottle conveying device 400 is controlled by the control device 900, and the bottles are held in the order of the bottle loading and unloading table, the first printing device 101, the second printing device 102, and the final curing device 200 The device 300 is transported cyclically. Among them, at the bottle loading and unloading station, the operator manually performs the loading and unloading operation of the bottle B on the conveyed bottle holding device 300. That is, when the printed bottle B is installed in the bottle holding device 300, the operator operates the gripping members 314, 324 to release the first holding portion 310 and the second holding portion 320 from holding the bottle B, and the printed bottle The bottle B of is removed from the bottle holding device 300. On the other hand, when the bottle B before printing is not attached to the bottle holding device 300, the operator loads the bottle B before printing into the bottle holding device 300, and operates the gripping members 314, 324 to make the first holding part 310 and the second holding portion 320 hold it. In this way, the installation operation of the bottle B is completed, and when the intention is input to an input device (not shown) such as an operation panel, the control device 900 that receives the intention conveys the bottle holding device 300 holding the bottle B to the first The printing device 101 performs printing processing.

The printing process is realized by the control device 900 executing a pre-stored program to make each part of the device execute a predetermined operation. In this printing process, the plate P is carried into the first printing device 101 and placed on the platform 11, and is subjected to calibration adjustment. On the other hand, in the bottle holding device 300 transported to the first printing device 101, the motor 341 starts to operate in response to the drive command from the control device 900, and the clutch 346 is switched to the ON state in response to the transmission command to transmit the rotation of the motor 341 Driving force. As a result, the bottle B rotates around the rotational symmetry axis AR. During the rotation, the printing start position of the bottle B is detected, and the rotation amount of the bottle B is adjusted based on the detection result, thereby positioning the bottle B in such a manner that the printing start position is opposed to the printing device 101. In addition, the positioning process can be performed based on the image obtained by capturing the image of the bottle B by the camera in the same way as the calibration adjustment process of the plate P, or based on the detection of a specific part of the bottle B by the sensor. Sensor input Out of the detection signal. Regardless of the method, in this embodiment, the positioning process of the bottle B with respect to the printing device 101 is automatically performed in parallel with the calibration adjustment process of the plate P. Of course, it may be configured to perform the positioning process of the bottle B in parallel with the receiving process of the ink pattern in the printing device 101 described below.

Then, the platform 11 of the first printing device 101 starts to move in the (+Y) direction, and the photocurable ink IK is applied to the upper surface of the plate P from the nozzle 21 of the ink filling unit 2, and the remaining ink is scraped off by the doctor blade 23. This fills the ink on the layout. The platform 11 further moves and passes through a position directly below the rotating blanket layer roller 30, thereby receiving the ink pattern formed on the plate P on the surface of the blanket layer 32. After that, the bottle holding device 300 moves in the (-Y) direction to press the printing start position of the side Ba of the bottle B against the surface of the blanket layer 32. Thereby, the transfer of the ink pattern from the blanket layer 32 to the bottle B is started. In this transfer process, the ink pattern on the surface of the blanket layer 32 is sequentially transferred to the bottle B by the blanket layer 32 receiving the ink pattern and the bottle B while abutting and rotating with each other.

Here, the body portion Bb of the bottle B abuts on the backup rollers 351, 352. If the ink pattern reaches the abutment position with the backup rollers 351, 352 along with the rotation of the bottle B, there is uncured ink from the bottle B. When transferring to backup rollers 351 and 352. In addition, when the bottle B rotates more than one revolution, the ink pattern on the side Ba of the bottle B may be transferred to the blanket layer 32 again. Such conditions will mess up the ink pattern on the side Ba of the bottle B, and contaminate the blanket layer 32 and the backup rollers 351 and 352 with ink.

In order to prevent this problem, a temporary curing treatment is performed by ultraviolet irradiation with relatively low exposure. That is, light (ultraviolet rays) is irradiated from the temporary curing unit 4 toward the surface of the bottle B immediately after the transfer of the ink pattern from the blanket layer 32. As described below, the light irradiated from the temporary curing unit 4 has the following properties, that is, by making the ink contained in the Part of the contained polymer material polymerizes to increase the viscosity of the ink, but it will not harden the ink as a whole.

By increasing the viscosity of the ink in this way and reducing the adhesion to other objects, the ink is prevented from being transferred to the side Ba of the bottle B carrying the ink when it comes into contact with the backup rollers 351 and 352 or the blanket layer 32.

When the printing process in the printing device 101 is completed, the bottle holding device 300 is transported from the first printing device 101 to the second printing device 102 while holding the bottle B printed with the above-mentioned ink pattern. Then, the second printing device 102 performs printing processing in the same manner as the first printing device 101. Thereby, another ink pattern is superimposed and printed on the printed ink pattern by the second printing device 102. After that, the bottle holding device 300 is transported from the second printing device 102 to the main curing device 200 while holding the bottle B printed with these ink patterns.

At this point in time, the ink is not completely hardened. In order to completely harden it, the main hardening device 200 irradiates the bottle B with light (ultraviolet rays) that is larger than that of the temporary hardening unit 4. In this way, the ink is completely hardened and printing is completed. After that, the bottle holding device 300 returns to the loading and unloading station from the main hardening device 200 while holding the bottle B. Perform this series of actions repeatedly.

As above, in this embodiment, the first holding portion 310 and the second holding portion 320 respectively rotatably hold the two ends of the bottle B on the axis X of the rotational symmetry axis AR, that is, the mouth edge portion Bc and the bottom portion Be . Therefore, it goes without saying that the bottle B whose body part Bb is cylindrical as described above, for other types of bottles, for example, has rotational symmetry around the rotational symmetry axis AR but the outer diameter of the side surface Ba changes in the axial direction X The bottle of this shape can also be well supported and held rotatably around the rotational symmetry axis AR. Therefore, the side Ba of the bottle B can also be printed well.

Also, bottle B is mass-produced, but in fact it is impossible to make the individual difference between them zero. For example, the shape of the male threaded portion screwed with the bottle cap is uniform to a certain extent, but the angle with respect to the rotational symmetry axis AR is often uneven among the plurality of bottles B. Therefore, even if the rim portion Bc and the bottom portion Be of the bottle B are held by the rim retaining member 313 and the bottom portion Be, respectively, it is difficult to always rotate the bottle B stably. When the degree of deformation of the rim portion Bc is large, there is a situation There is a possibility that a huge stress acts on the mouth edge Bc, which may cause the bottle B to be damaged. However, in this embodiment, since the self-aligning bearing 312 is interposed between the shaft 311 of the first holding portion 310 and the edge holding member 313, the bottle B can be stably rotated about the rotational symmetry axis AR. Therefore, it is possible to prevent a huge stress from acting on the edge portion Bc during the printing process.

In addition, in the bottle holding device 300 of the present embodiment, it is practically impossible to make the eccentricity of the bottle B zero when the bottle B is held and rotated. However, according to the present embodiment, the eccentricity can be suppressed to make the bottle B Stable rotation and less variation in the eccentricity of bottle B can enable bottle B to rotate with higher reproducibility. For example, when the eccentric characteristic is measured while the bottle B is held by the bottle holding device 300 to rotate about the rotational symmetry axis AR several times (3 times in the verification experiment shown in FIG. 6), the eccentricity characteristic shown in FIG. 6 is obtained. result.

Figure 6 is a graph showing the eccentricity characteristics of the bottle when the bottle is rotated by the bottle holding device shown in Figure 3. (a) ~ (c) in the figure represent the first rotation, the second rotation, and the third rotation. The eccentricity characteristic of the second rotation, (d) is a graph showing the eccentricity characteristic of the superposition. In the figure, the horizontal axis represents the rotation position, and the vertical axis represents the distance from the upper surface of the base 333 of the bottle holding device 300 to the center of the side surface of the bottle B. It can be seen from the graphs that the eccentricity of the bottle B can be suppressed, and the bottle B can be rotated around the rotational symmetry axis AR with high reproducibility. Therefore, by using this kind of bottle holding device 300 to hold the bottle In the state of B, the printing process of each printing device 101, 102 can not only suppress the skew of each ink pattern for printing, but also suppress the positional deviation between the two ink patterns, so that the desired image can be excellent The quality is printed to the side Ba of bottle B.

Furthermore, in this embodiment, since the motor 341 and the power transmission mechanism 342 are provided in the bottle holding device 300, and the positioning process is performed before the printing process of each printing device 101, 102, high-precision printing can be performed. Moreover, a clutch 346 is provided in the power transmission mechanism 342, and the clutch 346 switches between the rotation of the rotation driving force and the transmission interruption, which is suitable for the positioning process, and the rotation by the motor drive and suitable for transfer. The processing is driven by the rotation of the carpet layer 32. In this way, the bottle B can be rotated in a state suitable for the positioning process and the transfer process, so that the printing on the side Ba of the bottle B can be better performed.

As described above, in the above embodiment, the bottle B corresponds to an example of the "workpiece" of the present invention, and the bottle holding device 300 corresponds to an example of the "workpiece holding device" of the present invention. In addition, the rim portion Bc and the bottom portion Be of the bottle B correspond to examples of "one end of the workpiece" and "the other end of the workpiece" in the present invention, respectively. In addition, the pulleys 344a to 344c correspond to examples of the "first pulley", "second pulley", and "third pulley" of the present invention, respectively. In addition, the spring member 348 corresponds to an example of the "biasing member" of the present invention. Furthermore, the bottle conveying device 400 corresponds to an example of the "transporting device" of the present invention.

In addition, the present invention is not limited to the above-mentioned embodiment, and various changes other than the above can be made as long as it does not deviate from the gist. For example, in the printing system 100 of the above embodiment, the three pulleys 344a to 344c and the endless belt 345 are combined to transmit the rotational driving force from the motor 341 to the shaft 311, but for example, it may be configured as shown in FIG. Install the two gears 349a and 349b separately from the clutch 346 The combiner plate (not shown) and the shaft 311 perform power transmission (the second embodiment).

Furthermore, in the above-mentioned embodiment, the transmission of the rotational driving force generated by the motor 341 is blocked during the printing process, and the bottle B is driven to rotate with the rotation of the blanket layer 32, but it can also be used in the printing process. The bottle B and the blanket layer 32 are rotated synchronously by the rotational driving force.

In addition, in the above-mentioned embodiment, the bottle holding device 300 is provided with a rotation driving part 340 to rotate the shaft 311 to rotate the bottle B. However, the rotation driving part 340 may be omitted so that the bottle B always rotates. .

In addition, in the above-mentioned embodiment, two backup rollers 351 and 352 are used to support the bottle B. However, the number of backup rollers is not limited to this. For example, as shown in FIG. 8, four backup rollers 353~ 356 supports bottle B in a supplementary manner (third embodiment). In the third embodiment, the backup rollers 353, 354 are arranged on the opposite side of the blanket layer 32, that is, the (+Y) direction side, with the bottle B interposed in the pressing direction Y, and are contacted by the (+Y) direction side of the bottle B. +Y) The side surface restricts the displacement of bottle B in the (+Y) direction. In addition, the remaining spare rollers 355, 356 are arranged at a lower position than the spare rollers 353, 354 in the vertical direction Z, and by abutting against the side surface Ba of the bottle B from below, the bottle B is restricted from moving in the direction of gravity, that is (- Z) Displacement in the direction. In this way, in this embodiment, the backup rollers 353 and 354 function as the "first backup member" of the present invention, and on the other hand, the backup rollers 355 and 356 function as the "second backup member" of the present invention. Furthermore, when the bottle B can be stably held by the first holding portion 310 and the second holding portion 320, the backup roller may be omitted.

In addition, in the above embodiment, the present invention is applied to a printing system 100 equipped with two printing devices 101, 102 and two bottle holding devices 300 to overlap and print two kinds of ink patterns on the side Ba of the bottle B, but the printing The number of the device and the bottle holding device 300 is not limited to this, and one or more than three may be equipped.

Furthermore, in the above embodiment, the plate P is moved relative to the fixed blanket layer roller 30 by the platform 11, and the bottle holding device 300 moves the bottle B relative to the fixed blanket layer roller 30 to complete printing. Mutual positioning in processing. However, as long as the movement can be achieved relatively, the device to be movable is not limited to the above, but is arbitrary.

Furthermore, in the above-mentioned embodiment, the substantially cylindrical bottle B is an example of the "work" of the present invention, but the work is not limited to this. For example, for a cylindrical object with open ends, or an object with unevenness on the surface of a substantially cylindrical surface, as long as each object has a shape that is rotationally symmetric about the axis of rotation symmetry, it can also be combined with the above-mentioned bottle holding device 300 The work holding device configured in the same manner is rotatably held, and the work holding device is used in the printing system 100 to perform printing processing.

Above, the invention has been described according to specific embodiments, but this description is not intended to be interpreted in a limited meaning. By referring to the description of the invention, those skilled in the art can understand various modifications of the embodiments disclosed in the same manner as the other embodiments of the present invention. Therefore, it is considered that the scope of the attached patent application does not deviate from the true scope of the invention, and includes the modification or embodiment.

The present invention can be applied to all workpiece holding devices that rotatably hold the workpiece about the axis of rotational symmetry when printing on the side surface of the workpiece having a shape that is rotationally symmetric about the axis of rotational symmetry, and one side that holds the workpiece by the workpiece holding device. All printing techniques for printing on the side of the workpiece.

300: Bottle holding device

310: The first holding part

311, 321: Shaft

312: Self-aligning bearing

313: Mouth retaining member

314, 324: gripping member

320: second holding part

322: Bottom holding member

323: Spring member

330: Keep the body part

331: The first support part

332: The second support part

333: Abutment

340: Rotary drive unit

341: Motor (drive source)

342: Power Transmission Mechanism

346: Clutch

AR: rotational symmetry axis

B: Bottle (workpiece)

Ba: (of the bottle) side

Bb: (of the bottle) carcass

Bc: (of the bottle) rim

Bd: (of the bottle) male thread

Be: (of the bottle) bottom

X: axial

Y: compression direction

Z: Vertical direction

Claims (10)

A workpiece holding device which is used to hold the workpiece rotatably around the axis of rotational symmetry when the printing device is relatively pressed to the side surface of the workpiece having a shape that is rotationally symmetric about the axis of rotational symmetry, and the workpiece is held rotatably around the axis of rotational symmetry when printing is performed. It is characterized in that it includes: a holding body part; a first holding part that rotatably holds one end of the workpiece in the axial direction of the rotational symmetry axis with respect to the holding body part; and a second holding part that holds the The other end portion of the workpiece in the axial direction is rotatably held with respect to the holding body portion; and a first backup member that abuts against the side surface of the workpiece and supports the workpiece in a posture freely rotatable about the axis of rotational symmetry, Furthermore, it is rotatably provided around an axis parallel to the rotational symmetry axis; the first holding portion holds one end of the workpiece via a self-aligning bearing. The workpiece holding device of claim 1, wherein the workpiece is a bottle, the first holding portion has a lip holding member, and the lip holding member is rotatably provided with respect to the holding body portion via the self-aligning bearing The second holding portion has a bottom holding member that holds the bottom of the bottle. The workpiece holding device of claim 2, wherein the lip holding member has a female thread portion that can be screwed to a male thread portion provided on the lip portion, and the female thread portion is screwed to one of the lip portions The male screw portion holds the bottle. The workpiece holding device according to any one of claims 1 to 3, wherein the first backup member is arranged on the opposite side of the printing device with the workpiece interposed therebetween in a pressing direction against the printing device. The workpiece holding device of claim 4, wherein a second backup member is provided, and the second backup member abuts against the side of the workpiece in a vertical direction at a position lower than the first backup member, and supports around the side of the workpiece The above-mentioned workpiece in the posture that the rotational symmetry axis can rotate freely. The workpiece holding device according to any one of claims 1 to 3, which is provided with a rotation driving part that applies a rotation driving force to the first holding part so that the first holding part and the second holding part The workpiece held by the holding portion rotates around the rotational symmetry axis. The workpiece holding device according to claim 6, wherein the rotation driving portion has a driving source that generates the rotation driving force, and a power transmission mechanism that transmits the rotation driving force from the driving source to the first holding portion, and the power transmission mechanism A clutch is provided for switching between the transmission of the rotational driving force from the drive source to the first holding portion and the interruption of the transmission of the rotational driving force. The workpiece holding device according to claim 7, wherein the power transmission mechanism has: a first pulley that is rotated by the rotational driving force from the drive source; a second pulley that is connected to the first holding portion; and a third A pulley, which is set to be displaceable relative to the first pulley and the second pulley; an endless belt, which is erected on the first pulley, the second pulley, and the third pulley; and a urging member, by which By applying a force to the third pulley in a direction away from the first pulley and the second pulley, the endless belt The belt imparts tension. A printing system that prints on the side surface of a workpiece having a shape that is rotationally symmetric about an axis of rotational symmetry, characterized in that it is provided with: the workpiece holding device of any one of claims 1 to 3; the first printing A device for printing a first printing pattern on the side surface of the workpiece held by the workpiece holding device; a second printing device for printing a second printing pattern on the side surface of the workpiece held by the upper piece holding device; and conveying An apparatus for conveying the workpiece holding device holding the workpiece between the first printing device and the second printing device. A printing method, characterized in that it has the following steps: a step of holding a workpiece having a shape that is rotationally symmetric about an axis of rotation symmetry by the workpiece holding device of any one of claims 1 to 3; according to the first printing device The step of transporting the workpiece holding device holding the workpiece in the sequence of the second printing device; the first printing device is used to transport the workpiece held by the workpiece holding device to the first printing device. A step of printing a first printing pattern on the side; and printing a second printing pattern by the second printing device on the side of the workpiece held by the workpiece holding device that is transported from the first printing device to the second printing device A step of.

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