JP2020082605A - Work holding device, printing system and printing method - Google Patents

Abstract

To preferably print at a lateral face of a work by holding the work so as to be rotatable about a rotational symmetry axis while preferably supporting the work irrespective of the type of a work when printing at a lateral face of a work such as a container or bottle made of glass or plastic and having a rotational symmetrical shape about a rotational symmetry axis.SOLUTION: A work holding device includes: a holding body part; a first holding part for holding one end of a work in an axial direction of a rotational symmetry axis so as to be rotatable relative to the holding body part; and a second holding part for holding the other end of the work in the axial direction so as to be rotatable relative to the holding body part. The first holding part holds the one end of the work via an automatic aligning bearing.SELECTED DRAWING: Figure 3

Description

The present invention relates to a holding technique for rotatably holding a work around a rotational symmetry axis in order to perform printing on the side surface of the work such as a glass container or a plastic container having a rotationally symmetric axis about the rotational symmetry axis. is there.

For example, in glass and plastic containers and bottles that store high-value-added products such as cosmetics, it has been desired in recent years to perform high-quality printing on the side surfaces of the containers and the like. In order to meet such needs, a container such as a glass container or a plastic container having a rotationally symmetric shape around a rotational symmetry axis (corresponding to an example of the “work” of the present invention) is processed by gravure offset printing. It has been proposed to perform highly accurate printing on the side surface (body of the container). That is, in the printing apparatus, the intaglio is filled with ink to form an ink pattern, and the ink pattern is received on the surface of the cylindrical blanket roll. Then, the ink pattern on the blanket roll is transferred to the work by rotating the work around the rotational symmetry axis while bringing the side surface of the work into contact with the blanket roll carrying the ink pattern in the printing apparatus. In addition, multicolor printing is realized by moving a work between a plurality of different printing devices and overlapping ink patterns of a plurality of layers on the side surface of the work.

Here, when transferring the ink pattern to the work, it is necessary to hold the work rotatably around the rotational symmetry axis. Therefore, it is conceivable to use a mandrel as described in Patent Document 1 and Patent Document 2, for example.

International Publication No. 2009/044569 JP, 2009-101605, A

However, since the mandrel is inserted into the work from one side of the work in the axial direction of the rotational symmetry axis and supports the work from the inside, there are cases where the mandrel cannot be used depending on the type of the work. Even if a mandrel can be used, it is necessary to strongly press the side surface of the work against the blanket roll in order to perform the transfer process well. At this time, since the mandrel is inserted into the work in a so-called cantilever state to support the work from the inside, the force for supporting the work is different between the front end side and the rear end side of the mandrel, and the mandrel is not supported by the blanket roll. On the other hand, it may be difficult to uniformly press the side surface of the work. Further, it is desired to transfer the ink pattern to the shoulder portion of the work, but in order to further satisfy this need, it is necessary to increase the pressing force. However, there is also a problem that a sufficient pushing force cannot be obtained with a mandrel supported in a cantilever state.

The present invention has been made in view of the above problems, and when printing on the side surface of a work such as a glass or plastic container or bottle having a rotationally symmetric shape around a rotational symmetry axis, the type of the work is not limited. In addition, a work holding device capable of rotatably holding a work around a rotational symmetry axis while favorably supporting the work, and a printing system capable of favorably performing printing on a side surface of the work using the work holding device And a printing method.

According to a first aspect of the present invention, when printing is performed by pressing a printing device relative to the side surface of a work having a shape rotationally symmetrical about the axis of rotational symmetry, the work is rotatable about the axis of rotational symmetry. A work holding device for holding, a holding main body, a first holding part that rotatably holds one end of a work in the axial direction of a rotational symmetry axis with respect to the holding main body, and the other of the work in the axial direction. A second holding portion that holds the end portion rotatably with respect to the holding body portion, and the first holding portion holds one end portion of the work through a self-aligning bearing.

A second aspect of the present invention is a printing system for printing on a side surface of a work having a rotationally symmetric shape about a rotational symmetry axis, which is held by the work holding device and the work holding device. A first printing device that prints a first printing pattern on a side surface of a work, a second printing device that prints a second printing pattern on a side surface of a work held by a work holding device, and a work holding the work It is characterized in that it is provided with a carrying device for carrying the holding device between the first printing device and the second printing device.

Further, a third aspect of the present invention is a printing method, which comprises a step of holding a work having a rotationally symmetric shape about a rotational symmetry axis by the work holding device, and a work holding device holding the work. And the step of transporting the second printing device in this order, and the first printing device applies the first printing pattern to the side surface of the work held by the work holding device that has been transported to the first printing device. A step of printing, and a step of printing a second print pattern by the second printing device on the side surface of the work held by the work holding device conveyed from the first printing device to the second printing device. It is characterized by

In the invention thus configured, one end portion and the other end portion of the work are rotatably held by the first holding portion and the second holding portion in the axial direction of the rotational symmetry axis. Therefore, the work is held well by the work holding device. Therefore, when printing is performed on the side surface of the work by the printing apparatus, printing is performed on the side surface of the work while the printing apparatus is pressed firmly against the side surface of the work. Further, even if the rotational symmetry axis deviates to some extent due to the individual difference of the work, the self-aligning bearing absorbs the deviation of the rotational symmetry axis and stably rotates the work.

As described above, according to the present invention, regardless of the type of the work having a rotationally symmetric shape about the rotational symmetry axis, the work can be favorably held rotatably about the rotational symmetry axis, and Good printing can be performed on the side surface.

It is a schematic diagram showing an example of schematic composition of a printing system which prints the side of a work using a 1st embodiment of a work maintenance device concerning the present invention. It is a figure which shows the structure of a plate stage unit and an ink filling unit. It is a figure which shows the structure of the bottle holding device and the bottle hold|maintained at the bottle holding device. It is a perspective view which shows typically the structure of the rotation drive part with which a bottle holding device is equipped. FIG. 4 is a side view of the bottle holding device shown in FIG. 3. 4 is a graph showing eccentricity characteristics when the bottle is rotated by the bottle holding device shown in FIG. 3. It is a figure which shows 2nd Embodiment of the workpiece holding apparatus which concerns on this invention. It is a figure which shows 3rd Embodiment of the workpiece holding apparatus which concerns on this invention.

FIG. 1 is a schematic diagram showing a schematic configuration example of a printing system that prints a side surface of a work by using the first embodiment of the work holding device according to the present invention. The printing system 100 includes articles (hereinafter, collectively referred to as articles having a rotationally symmetric shape about a rotational symmetry axis (reference numeral AR in FIG. 3) such as a glass container and a bottle, a resin container and a bottle, and the like. It is a system for printing on the side surface Ba of the "bottle B"), the bottle B corresponds to an example of the "workpiece" of the present invention, and the bottle holding device for holding the bottle B is the "workpiece" of the present invention. Corresponds to an example of a "workpiece holding device". Here, in order to uniformly indicate the directions in the respective drawings, an XYZ orthogonal coordinate system is set as shown in FIG. For example, the XY plane can be considered as a horizontal plane and the Z axis can be considered as a vertical axis. In the following, the (-Z) direction is vertically downward. Further, in each of the following drawings, a dotted arrow provided in the vicinity of a constituent element indicates the movement of the constituent element.

The printing system 100 includes two sets of printing devices, that is, a first printing device 101 and a second printing device 102, which print on the side surface Ba of the bottle B with one ink color. Therefore, the printing system 100 can perform two-color printing on the side surface Ba of the bottle B. It should be noted that it is also possible to configure a monochromatic printing system with one set of printing devices or a multicolor printing system with three or more sets of printing devices.

The first printing device 101 and the second printing device 102 respectively include a plate stage unit 1, an ink filling unit 2, a transfer unit 3, and a temporary curing unit 4. These units are arranged side by side in the above order from the (−Y) direction side toward the (+Y) direction side. A main curing device 200 is provided near the second printing device 102. Between the first printing device 101, the second printing device 102, the main curing device 200, and the bottle attaching/detaching station (not shown), the bottle B is circulated by the bottle transport device 400 while being held by the bottle holding device 300. Be transported. In the present embodiment, the mounting and removal of the bottle B with respect to the bottle holding device 300 is performed manually by the operator at the bottle attaching/detaching station. On the other hand, in order to automate other tasks, the printing system 100 further includes a control device 900 that controls the operation of each of these units.

The first printing apparatus 101 and the second printing apparatus 102 have the same configuration and execute the same operation, as described below. The configuration and operation of the bottle holding device 300 will be described in detail later.

The printing process in the printing system 100 is
(1) Formation of an ink pattern using photocurable ink by the plate stage unit 1 and the ink filling unit 2,
(2) Transfer of the ink pattern to the transfer unit 3,
(3) Transfer of the ink pattern from the transfer unit 3 to the side surface Ba of the bottle B,
(4) Temporary curing of ink by light irradiation from the temporary curing unit 4,
After performing the single-color printing operation including the respective steps in each of the printing apparatuses 101 and 102,
(5) Main curing of ink by the main curing device 200,
Complete by executing.

More specifically, the bottle B is attached/detached to/from the bottle holding device 300 by an operator's manual operation at the bottle attaching/detaching station. That is, after the printed bottle B is removed from the bottle holding device 300, the bottle B to be printed is attached to the bottle holding device 300. The bottle B thus mounted is held by the bottle holding device 300 so as to be rotatable around the rotational symmetry axis, and in that state, 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 apparatus 101, the bottle holding device 300 holds the bottle B rotatably, and the steps (1) to (4) are performed on the bottle B. After that, the bottle holding device 300 holding the bottle B is conveyed from the first printing device 101 to the second printing device 102.

FIG. 2 is a diagram showing the configurations of the plate stage unit and the ink filling unit. The plate stage unit 1 includes a stage 11 on which a plate (for example, an intaglio plate) P for forming an ink pattern is placed. The stage 11 is attached to the base portion 13 via the alignment mechanism 12. The alignment mechanism 12 moves the stage 11 in the XYZ directions and the rotation directions around the Z-axis in response to a control command from the control device 900. For example, a cross roller bearing mechanism can be used as the alignment mechanism 12.

The base portion 13 is engaged with a guide rail 14 extending in the Y direction on the pedestal of the printing system 100, and can reciprocate in the Y direction along the guide rail 14. More specifically, a drive mechanism (not shown) controlled by the control device 900 is connected to the base portion 13, and the drive mechanism operates so that the base portion 13 moves in the (−Y) direction and the (+Y) direction. Move to. The home position of the base portion 13 is the position closest to the (−Y) direction side of the movable range of the base portion 13 (the position indicated by the solid line in FIG. 2).

Alignment cameras 15 and 15 are arranged above the stage 11 in the home position. The alignment cameras 15 and 15 image an alignment mark provided on the peripheral portion of the plate P placed on the stage 11 or on the upper surface of the plate P, and send image data to the control device 900. The control device 900 detects the position of the plate P on the stage 11 and operates the alignment mechanism 12 as necessary to adjust the position of the plate P to an appropriate position.

The ink filling unit 2 and the transfer unit 3 are provided along the path along which the base portion 13 moves in the (+Y) direction from the home position. The ink filling unit 2 includes nozzles 21 that face the upper surface of the plate P placed on the stage 11 that passes directly below. The photocurable ink (hereinafter, may be simply referred to as “ink”) is supplied to the nozzle 21 from the ink supply unit 22 controlled by the control device 900. The supplied ink is ejected from the ejection port provided at the lower end of the nozzle 21 and applied on the upper surface of the plate P.

A photo-curable ink consists of 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 an active species that is generated by a chemical change when exposed to light. It contains a photopolymerization initiator that accelerates the polymerization reaction of the polymer material.

A doctor blade 23 is provided on the (+Y) direction side of the nozzle 21. The doctor blade 23 scrapes the ink by rubbing the surface of the plate P supplied with the ink. As a result, ink is filled in the recesses provided on the upper surface of the plate P, while the other excess ink is removed to form an ink pattern.

The plate P filled with ink in this way further moves in the (+Y) direction and reaches the position where the transfer unit 3 is disposed. As shown in FIGS. 1 and 2, the transfer unit 3 includes a blanket roll 30 and a motor 33 that rotates the blanket roll 30. More specifically, the blanket roll 30 includes a blanket cylinder 31 which is, for example, a metal cylinder, and a blanket 32 wound around the surface of the blanket cylinder 31, and has a substantially cylindrical shape as a whole. The blanket roll 30 is rotatably supported by a frame (not shown), and is rotationally driven by a motor 33 controlled by the control device 900 about a central axis shown by a chain line in FIG.

The blanket 32 is made of an elastic resin material, for example, a silicon resin, and can carry an ink pattern on its surface. The blanket 32 has a thickness sufficiently larger than the unevenness that may occur on the surface of the bottle B, which is the side surface Ba of the bottle B. As shown in FIG. 2, when the plate P placed on the stage 11 passes directly below the blanket roll 30, the surface of the blanket 32 contacts the upper surface of the plate P. At this time, the ink filled in the recesses of the plate P moves to the surface of the blanket 32. In this way, the ink pattern on the plate P is received by the blanket 32.

The ink pattern once received (primarily transferred) on the blanket 32 in this manner is secondarily transferred to the surface of the bottle B, which is the final side surface Ba of the bottle B. In this way, the blanket 32 functions as an intermediate transfer member that temporarily carries the ink pattern that is finally transferred to the side surface Ba of the bottle B. In the present embodiment, the two printing devices 101 and 102 are installed to form two types of ink patterns. However, the ink patterns formed by the printing devices 101 and 102 are respectively the “first It corresponds to an example of a “print pattern” and a “second print pattern”.

FIG. 3 is a diagram showing a configuration 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 a bottle cap (not shown) removed. The bottle B is made of, for example, a resin material or a glass material whose main material is polyethylene terephthalate (PET), and has a rotationally symmetric shape around the rotational symmetry axis AR. In the present embodiment, the body Bb of the bottle B is finished into a cylindrical shape, and two types of ink patterns are superposed and printed on the surface of the body Bb, that is, the side surface Ba of the bottle B. Further, it is possible to store beverages such as water, tea and juice, cosmetics, etc. inside the bottle B. In the bottle B, the mouth portion Bc is formed on one side in the axial direction X of the rotational symmetry axis AR, that is, on the (+X) direction side. The mouth portion Bc referred to here is a mouth portion in a range in which the bottle cap is generally attached from the shoulder portion of the body portion Bb. An opening is provided on the end surface of the mouth portion Bc in the (+X) direction, and a male screw portion Bd is appropriately formed from the vicinity of the opening toward the (−X) direction. The mouth portion Bc and the bottom portion Be of the bottle B configured in this manner 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 rotates in a horizontal position around the rotational symmetry axis AR. It is held freely and is further rotated appropriately.

The bottle holding device 300 has a holding body portion 330 that holds the bottle B rotatably via the first holding portion 310 and the second holding portion 320. The holding body section 330 has a flat plate-shaped base 333, a first support section 331, and a second support section 332. The first support portion 331 is provided upright from the base 333 on the (+X) direction side. Further, the second support portion 332 is separated from the base 333 at a position slightly separated from the first support portion 331 in the (−X) direction by a distance slightly wider than the height of the bottle B (corresponding to the size in the X direction in FIG. 3). It stands upright.

The first holding unit 310 has a shaft 311 extending in the X direction. The shaft 311 is rotatably supported on the first support portion 331, and a mouth holding member 313 is attached to an end portion in the (−X) direction via a self-aligning bearing 312. A female screw portion is formed inside the mouth holding member 313. Therefore, when the operator rotates the knob member 314 attached to the (+X) direction end portion of the shaft 311 while holding the bottle B and restricting the rotation of the bottle B, the male screw portion provided at the mouth portion Bc. The mouth-holding member 313 is screwed with Bd to be connected to the bottle B in a horizontal posture. On the contrary, the operator can remove the mouth holding member 313 from the bottle B by rotating the knob member 314 to the opposite side while regulating the rotation of the bottle B. Note that the manner of holding the mouth portion Bc by the mouth holding member 313 is not limited to the above-described screw structure, and for example, a grip structure in which a plurality of gripping members are used for gripping may be employed.

On the other hand, the second holding unit 320 has a shaft 321 extending in the X direction. The shaft 321 is rotatably supported by the second support portion 332 in a state of being arranged so as to coincide with the axis of the shaft 311. Further, a bottom holding member 322 finished in a shape that can engage with the bottom portion Be of the bottle B is attached to the (+X) direction end portion of the shaft 321. A spring member 323 is loosely inserted in the shaft 321 between the bottom holding member 322 and the (+X) side wall surface of the second support portion 332, and biases the bottom holding member 322 to the bottom portion Be of the bottle B. Therefore, as shown in FIG. 3, the bottom holding member 322 biases and holds the bottom portion Be of the bottle B in a state where the bottle B is arranged in a horizontal posture and the mouth portion Bc is connected by the mouth holding member 313. Then, the rotational symmetry axis AR of the bottle B substantially coincides with the axes of the shafts 311 and 321, and the bottle B becomes rotatable around the rotational symmetry axis AR. On the other hand, when the operator pulls the knob member 324 attached to the end portion of the shaft 321 in the (−X) direction in the (−X) direction against the biasing force of the spring member 323, the bottom holding member 322 causes the bottom portion Be of the bottle B to have a bottom Be. It becomes possible to remove the bottle B apart from.

As described above, in the bottle holding device 300, the bottle B is held rotatably around the rotational symmetry axis AR by the first holding unit 310 and the second holding unit 320, and the rotation driving unit 340 is further provided by the first supporting unit 331. It is possible to rotate the bottle B by rotating the shaft 311. Hereinafter, the configuration and operation of the rotation drive unit 340 will be described in detail with reference to FIGS. 3 and 4.

FIG. 4 is a perspective view schematically showing the configuration of the rotation drive unit equipped in the bottle holding device. The rotation driving unit 340 uses the motor 341 fixed to the first support unit 331 as the “driving source” of the present invention, and applies the rotation driving force generated by the motor 341 to the shaft 311 via the power transmission mechanism 342 as appropriate. B is rotated around the rotational symmetry axis AR. The power transmission mechanism 342 includes two gears 343a and 343b, three pulleys 344a to 344c, an endless belt 345 suspended between the pulleys 344a to 344c, and a clutch 346. The gear 343a is attached to the rotating shaft of the motor 341. A gear 343b meshes with the gear 343a, and a pulley 344a is connected to the gear 343b via a clutch 346. Further, the pulley 344a is connected to the pulleys 344b and 344c by the endless belt 345. Of these, the pulley 344b is attached to the shaft 311, and the pulley 344c is attached to the swing member 347. The swinging member 347 is biased in the direction R away from the pulleys 344a and 344b by receiving the biasing force of the spring member 348. In this way, the pulley 344c is provided so as to be displaceable with respect to the pulleys 344a and 344b, functions as a so-called tension pulley, the endless belt 345 is stretched between the pulleys 344a to 344c, and tension is applied as the pulley 344c is displaced. is recieving. Therefore, when the clutch 346 is switched to the ON state in response to the transmission command from the control device 900, the pulley 344a rotates together with the gear 343b, and the power is transmitted 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 power transmission is cut off. As a result, the bottle B is kept rotatable about the rotational symmetry axis AR, and when the ink pattern is transferred from the blanket 32, the bottle B can be driven to rotate along with the movement of the blanket 32. ing.

As described above, the bottle B is rotatably driven in the horizontal posture by the rotation driving unit 340 or is driven to rotate with respect to the blanket 32, but in order to support the bottle B in an auxiliary manner and stabilize the posture of the bottle B, the bottle is held. The device 300 includes two backup rollers 351 and 352 as shown in FIG.

FIG. 5 is a side view of the bottle holding device shown in FIG. The backup rollers 351 and 352 have a shaft body structure with the X direction as the axial direction, and are rotatably supported by the first support portion 331 and the second support portion 332. Of these, the backup roller 351 is arranged on the opposite side of the blanket 32, that is, on the (+Y) direction side with the bottle B sandwiched in the pressing direction Y in which the side surface Ba of the bottle B is pressed against the blanket 32 of the printing apparatuses 101 and 102. ing. The backup roller 351 contacts the side surface of the bottle B on the (+Y) direction side to regulate the displacement of the bottle B in the (+Y) direction.

The other backup roller 352 is arranged at a position lower than the backup roller 351 in the vertical direction Z. When the backup roller 352 comes into contact with the side surface Ba of the bottle B from below, the displacement of the bottle B in the gravity direction, that is, the (−Z) direction is restricted. Thus, in the present embodiment, the backup rollers 351 and 352 function as the “first backup member” and the “second backup member” of the present invention, respectively.

In the printing system 100 configured as described above, the bottle conveying device 400 is controlled by the control device 900, so that the bottle holding device 300 causes the bottle attaching/detaching station, the first printing device 101, the second printing device 102, and the book. It is circulated and conveyed in the order of the curing device 200. At the bottle attaching/detaching station, the operator manually attaches/detaches the bottle B to/from the transported bottle holding device 300. That is, when the printed bottle B is attached to the bottle holding device 300, the operator operates the knob members 314 and 324 to release the holding of the bottle B by the first holding unit 310 and the second holding unit 320. The printed bottle B 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 carries the bottle B before printing into the bottle holding device 300 and operates the knob members 314 and 324 to operate the first holding unit. 310 and the second holding unit 320. When the mounting operation of the bottle B is completed in this way and the fact is input to an input device (not shown) such as an operation panel, the control device 900 that has received the operation sets the bottle holding device 300 holding the bottle B to the first printing device. The sheet is conveyed to 101 and printing processing is performed.

This printing process is realized by the control device 900 executing a prestored program and causing each part of the device to perform a predetermined operation. In this printing process, the plate P is carried into the first printing apparatus 101, set on the stage 11, and subjected to alignment adjustment. On the other hand, in the bottle holding device 300 conveyed to the first printing device 101, the motor 341 starts operating in response to the drive command from the control device 900, and the clutch 346 switches to the ON state in response to the transmission command. The rotational driving force of the motor 341 is transmitted. As a result, the bottle B rotates about the rotational symmetry axis AR. By detecting the print start position of the bottle B during the rotation and adjusting the rotation amount of the bottle B based on the detection result, the bottle B is positioned so that the print start position faces the printing apparatus 101. Note that this positioning processing may be performed based on an image obtained by capturing an image of the bottle B by the camera as in the alignment adjustment processing of the plate P, or by detecting a specific portion of the bottle B with a sensor. You may perform based on the detection signal output from. In any case, in the present embodiment, the positioning process of the bottle B with respect to the printing apparatus 101 is automatically performed in parallel with the alignment adjustment process of the plate P. Of course, the bottle B positioning processing may be performed in parallel with the ink pattern receiving processing in the printing apparatus 101 described below.

Subsequently, the stage 11 of the first printing apparatus 101 starts moving in the (+Y) direction, 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 surplus is caused by the doctor blade 23. When the ink is scraped off, the plate surface is filled with the ink. When the stage 11 further moves and passes directly below the rotating blanket roll 30, the ink pattern formed on the plate P is received on the surface of the blanket 32. After that, the bottle holding device 300 moves in the (−Y) direction and presses the print start position of the side surface Ba of the bottle B against the surface of the blanket 32. As a result, the transfer of the ink pattern from the blanket 32 to the bottle B is started. In this transfer process, the blanket 32 receiving the ink pattern and the bottle B are rotated in contact with each other while being in contact with each other, whereby the ink pattern on the surface of the blanket 32 is sequentially transferred to the bottle B.

Here, the body portion Bb of the bottle B is in contact with the backup rollers 351 and 352, and when the ink pattern reaches the contact position with the backup rollers 351 and 352 as the bottle B rotates, the uncured ink remains in the bottle. It may be transferred from B to the backup rollers 351 and 352. Further, when the bottle B rotates for one rotation or more, the ink pattern on the side surface Ba of the bottle B may be retransferred to the blanket 32. These disturb the ink pattern on the side surface Ba of the bottle B and contaminate the blanket 32 and the backup rollers 351 and 352 with ink.

In order to prevent this problem, a temporary curing process is performed by irradiating a relatively low dose of ultraviolet rays. That is, light (ultraviolet rays) is emitted from the temporary curing unit 4 toward the surface of the bottle B immediately after receiving the transfer of the ink pattern from the blanket 32. As will be described later, the light emitted from the temporary curing unit 4 has the property of increasing the viscosity of the ink by polymerizing a part of the polymer material contained in the ink, but not curing the entire ink. It is a thing.

As the viscosity of the ink increases in this way, the adhesion to other objects decreases, and when the side surface Ba of the bottle B carrying the ink contacts the backup rollers 351, 352 or the blanket 32, the ink is transferred to these. It is prevented from being lost.

When the printing process in the printing device 101 is completed, the bottle holding device 300 is conveyed from the first printing device 101 to the second printing device 102 while holding the bottle B on which the ink pattern is printed. Then, the printing process is performed by the second printing device 102 in the same manner as the first printing device 101. As a result, another ink pattern is printed by the second printing device 102 on the already printed ink pattern. After that, the bottle holding device 300 is conveyed from the second printing device 102 to the main curing device 200 while holding the bottle B on which these ink patterns are printed.

The ink is not completely cured at this point. In order to completely cure this, the main curing device 200 irradiates the bottle B with light (ultraviolet light) having a larger output than that of the temporary curing unit 4. This completely cures the ink and completes printing. After that, the bottle holding device 300 is returned from the main curing device 200 to the attaching/detaching station while holding the bottle B. Such a series of operations is repeatedly executed.

As described above, in the present embodiment, both ends of the bottle B in the axial direction X of the rotational symmetry axis AR, that is, the mouth part Bc and the bottom part Be are rotatably held by the first holding part 310 and the second holding part 320, respectively. is doing. Therefore, as described above, not only the bottle B having the cylindrical body portion Bb but also other types of bottles, for example, those having a rotationally symmetric shape about the rotational symmetry axis AR, have an outer diameter dimension of the side surface Ba in the axial direction. A bottle having a shape that changes in X can be rotatably held around the rotational symmetry axis AR while being well supported. Therefore, printing can be favorably performed on the side surface Ba of the bottle B.

Although the bottles B are mass-produced, it is practically impossible to reduce the individual difference between them to zero. For example, although the shape of the male screw portion screwed with the bottle cap is uniform to some extent, the angle with respect to the rotation axis AR often varies among the plurality of bottles B. Therefore, even if the mouth portion Bc and the bottom portion Be of the bottle B are held by the mouth holding member 313 and the bottom portion Be, respectively, it is difficult to constantly rotate the bottle B stably, and when the degree of deformation of the mouth portion Bc is large. There is a possibility that a large amount of stress acts on the mouth portion Bc to damage the bottle B. However, in this embodiment, since the self-aligning bearing 312 is interposed between the shaft 311 of the first holding unit 310 and the mouth holding member 313, the bottle B is stably rotated around the rotational symmetry axis AR. Therefore, it is possible to prevent a large amount of stress from being applied to the mouth portion Bc during the printing process.

Further, in the bottle holding device 300 according to the present embodiment, when the bottle B is held and rotated, it is virtually impossible to set the eccentricity of the bottle B to zero, but according to the present embodiment, the eccentric amount It is possible to rotate the bottle B with high reproducibility while suppressing eccentricity and allowing stable rotation. For example, when the eccentricity characteristic is measured while holding the bottle B by the bottle holding device 300 and rotating it about the rotational symmetry axis AR multiple times (three times in the verification experiment shown in FIG. 6), the results shown in FIG. 6 are obtained.

FIG. 6 is a graph showing eccentricity characteristics when the bottle is rotated by the bottle holding device shown in FIG. 3, and (a) to (c) in FIG. 6 are the first rotation, the second rotation, and the third rotation, respectively. And (d) is a graph in which the eccentricity characteristics are superimposed. In the figure, the horizontal axis represents the rotational 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. As can be seen from these graphs, the bottle B can be rotated around the rotational symmetry axis AR with high reproducibility while suppressing the amount of eccentricity of the bottle B. Therefore, it is possible not only to suppress the distortion of each ink pattern and perform printing by performing the printing process in each of the printing devices 101 and 102 while holding the bottle B in the bottle holding device 300, but also between the two ink patterns. It is also possible to suppress the positional deviation at the time, and it is possible to print a desired image on the side surface Ba of the bottle B with excellent quality.

Further, in this embodiment, since the bottle holding device 300 is provided with the motor 341 and the power transmission mechanism 342 and the positioning process is performed before the printing process in each of the printing devices 101 and 102, highly accurate printing can be performed. .. Moreover, the power transmission mechanism 342 is provided with the clutch 346, and the clutch 346 controls the transmission and the cutoff of the rotation driving force to follow the rotation by the motor drive suitable for the positioning process and the rotation of the blanket 32 suitable for the transfer process. Switching between rotation and. In this way, the bottle B can be rotated in a mode suitable for the positioning process and the transfer process, and the printing on the side surface Ba of the bottle B can be performed even better.

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. Further, the mouth portion Bc and the bottom portion Be of the bottle B correspond to examples of the "one end portion of the work" and the "other end portion of the work" of the present invention, respectively. Further, the pulleys 344a to 344c respectively correspond to examples of the "first pulley", the "second pulley", and the "third pulley" of the present invention. Further, the spring member 348 corresponds to an example of the "biasing member" of the present invention. Further, the bottle transfer device 400 corresponds to an example of the “transfer device” of the present invention.

The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the printing system 100 of the above-described embodiment, the rotational driving force from the motor 341 is transmitted to the shaft 311 by combining the three pulleys 344a to 344c and the endless belt 345, but as shown in FIG. The two gears 349a and 349b may be attached to the clutch plate (not shown) of the clutch 346 and the shaft 311, respectively, so as to transmit power (second embodiment).

Further, in the above-described embodiment, when the printing process is performed, the transmission of the rotational driving force generated by the motor 341 is interrupted and the bottle B is driven to rotate in accordance with the rotation of the blanket 32. The bottle B may be rotated in synchronization with the blanket 32 by the driving force.

Further, in the above embodiment, the rotation driving unit 340 is provided in the bottle holding device 300 and the shaft 311 is rotationally driven to rotate the bottle B. However, the rotation driving unit 340 is omitted and the bottle B is always used. May be driven to rotate.

Further, in the above-described embodiment, the bottle B is supplementarily supported by the two backup rollers 351 and 352, but the number of backup rollers is not limited to this, and for example, as shown in FIG. The bottle B may be supplementarily supported by the book backup rollers 353 to 356 (third embodiment). In the third embodiment, the backup rollers 353 and 354 are arranged on the opposite side of the blanket 32 in the pressing direction Y, that is, on the (+Y) direction side, and on the (+Y) direction side surface of the bottle B. The abutment restricts the displacement of the bottle B in the (+Y) direction. Further, the remaining backup rollers 355 and 356 are arranged at a position lower than the backup rollers 353 and 354 in the vertical direction Z, and come into contact with the side surface Ba of the bottle B from below to move in the gravity direction, that is, the (−Z) direction. The displacement of the bottle B is regulated. As described above, in this embodiment, the backup rollers 353 and 354 function as the “first backup member” of the present invention, while the backup rollers 355 and 356 function as the “second backup member” of the present invention. If the bottle B can be stably held by the first holding unit 310 and the second holding unit 320, the backup roller may be omitted.

Further, in the above-described embodiment, the present invention is applied to the printing system 100 that is equipped with the two printing devices 101 and 102 and the two bottle holding devices 300 and that prints two types of ink patterns by superimposing them on the side surface Ba of the bottle B. However, the number of printing devices and bottle holding devices 300 is not limited to this, and one device or three or more devices may be provided.

Further, in the above-described embodiment, the plate stage 11 moves the plate P and the bottle holding device 300 moves the bottle B with respect to the fixed blanket roll 30, thereby performing mutual positioning in the printing process. However, it is sufficient that these movements are relatively realized, and which device is movable is not limited to the above and is arbitrary.

Furthermore, in the above-described embodiment, the substantially cylindrical bottle B is an example of the “work” in the present invention, but the work is not limited to this. For example, for a cylindrical object whose both ends are open, or an object in which unevenness is provided on the surface which is a substantially cylindrical surface, as long as each object has a rotationally symmetric shape about the rotational symmetry axis, It is possible to rotatably hold the work by a work holding device having the same structure as the bottle holding device 300, and to execute a printing process using the work holding device in the printing system 100.

The present invention relates to an overall work holding device that holds a work rotatably around the rotational symmetry axis when printing is performed on a side surface of the work having a rotational symmetry axis about the rotational symmetry axis, and a work holding device for holding the work. It can be applied to all printing techniques for printing on the side surface of a work while holding it.

100... Printing system 101... First printing device 102... Second printing device 300... Bottle holding device 310... First holding part 312... Self-aligning bearing 313... Mouth holding member 320... Second holding part 322... Bottom holding Member 348... Spring member (biasing member)
330... Holding main body part 331... 1st support part 332... 2nd support part 333... Base stand 340... Rotation drive part 341... Motor (drive source)
342... Power transmission mechanism 344a... (First) pulley 344b... (Second) pulley 344c... (Third) pulley 345... Endless belt 346... Clutch 351, 353, 354... (First) backup roller 352, 355, 356 …(Second) Backup roller 400…Bottle carrier AR…Rotation symmetry axis B…Bottle (work)
Ba... (bottle) side surface Bc... (bottle) mouth portion Bd... male screw portion Be... (bottle) bottom portion X... axial direction Y... pushing direction Z... vertical direction

Claims (10)

A work holding device for rotatably holding the work around the rotational symmetry axis when printing is performed by pressing the printing device relatively to the side surface of the work having a rotational symmetry axis about the rotational symmetry axis. hand,
A holding body,
A first holding part that holds one end of the work in the axial direction of the rotational symmetry axis so as to be rotatable with respect to the holding body part;
A second holding portion that holds the other end portion of the work in the axial direction rotatably with respect to the holding body portion,
The work holding device, wherein the first holding portion holds one end of the work via a self-aligning bearing. The work holding device according to claim 1,
The work is a bottle,
The first holding portion has a mouth holding member that holds the mouth portion of the bottle in a state of being rotatably provided with respect to the holding body portion via the self-aligning bearing,
The second holding unit is a work holding device having a bottom holding member that holds the bottom of the bottle. The work holding device according to claim 2, wherein
The mouth-holding member has a female screw portion that can be screwed into a male screw portion provided in the mouth portion, and the bottle is formed by screwing the female screw portion into the male screw portion of the mouth portion. Work holding device that holds the workpiece. The work holding device according to any one of claims 1 to 3,
Arranged to be opposite to the printing device with the work sandwiched in the pressing direction of pressing the printing device, and contacting the side surface of the work to support the work in a posture rotatable around the rotational symmetry axis; 1 Work holding device equipped with a backup member. The work holding device according to claim 4,
A work holding device comprising a second backup member that abuts a side surface of the work at a position lower than the first backup member in the vertical direction and supports the work in a posture in which the work is rotatable about the rotational symmetry axis. The work holding device according to any one of claims 1 to 5,
A work holding device comprising: a rotation driving unit that applies a rotation driving force to the first holding unit to rotate the work held by the first holding unit and the second holding unit around the rotational symmetry axis. The work holding device according to claim 6,
The rotation drive unit includes a drive source that generates the rotation drive force, and a power transmission mechanism that transmits the rotation drive force from the drive source to the first holding unit,
The power transmission mechanism is a work holding device having a clutch that switches between transmission of the rotational driving force from the drive source to the first holding unit and interruption of transmission of the rotational driving force. The work holding device according to claim 7,
The power transmission mechanism includes a first pulley that rotates by receiving the rotational driving force from the drive source, a second pulley that is connected to the first holding portion, and the first pulley and the second pulley. A displaceable third pulley, an endless belt hung on the first pulley, the second pulley and the third pulley, and the third pulley separated from the first pulley and the second pulley. A work holding device having a biasing member that applies tension to the endless belt by biasing the endless belt. A printing system for printing on a side surface of a work having a rotationally symmetric shape about a rotational symmetry axis,
A work holding device according to any one of claims 1 to 8,
A first printing device that prints a first print pattern on a side surface of the work held by the work holding device;
A second printing device for printing a second printing pattern on a side surface of the work held by the work holding device;
A printing system comprising: a conveyance device that conveys the work holding device holding the work between the first printing device and the second printing device. Holding a work having a rotationally symmetric shape about a rotational symmetry axis by the work holding device according to any one of claims 1 to 8,
Transporting the work holding device holding the work in the order of a first printing device and a second printing device;
Printing a first print pattern on the side surface of the work held by the work holding device that has been conveyed to the first printing device by the first printing device;
A step of printing a second print pattern by the second printing device on the side surface of the work held by the work holding device that has been conveyed from the first printing device to the second printing device. A printing method characterized by the above.

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