JP7181066B2 - WORK HOLDING DEVICE, PRINTING SYSTEM AND PRINTING METHOD - Google Patents

Description

The present invention relates to a holding technique for holding a workpiece rotatably around the axis of rotational symmetry in order to print on the side surface of the workpiece such as a glass container or plastic container having a shape that is rotationally symmetrical about the axis of rotational symmetry. be.

2. Description of the Related Art In recent years, there has been a demand for high-quality printing on the sides of containers and bottles made of glass or plastic that contain high-value-added products such as cosmetics. In order to meet such needs, a container such as a glass container or a plastic container having a rotationally symmetrical shape around an axis of rotational symmetry (corresponding to an example of the "work" of the present invention) is processed by gravure offset printing. It has been proposed to print the sides (body of the container) with high precision. That is, in a printing apparatus, an intaglio is filled with ink to form an ink pattern, and the ink pattern is received on the surface of a cylindrical blanket roll. Then, in the printing apparatus, the ink pattern on the blanket roll is transferred to the work by rotating the work around the axis of rotational symmetry while bringing the side of the work into contact with the blanket roll carrying the ink pattern. In addition, multi-color printing is realized by moving a work between a plurality of printing apparatuses different from each other and superimposing a plurality of layers of ink patterns on the side of the work.

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

WO2009/044569 JP 2009-101605 A

However, since the mandrel is inserted into the work from one side in the axial direction of the axis of rotational symmetry and supports the work from the inside, there are cases where the mandrel cannot be used depending on the type of work. Further, 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, the mandrel is inserted into the work in a so-called cantilevered state and supports the work from the inside. In some cases, it is difficult to press the side of the workpiece evenly. In addition, there is a demand for transferring an ink pattern to the shoulder portion of a work, and in order to further satisfy this need, it is necessary to increase the pressing force. However, there is also the problem that a sufficient pressing force cannot be obtained with a mandrel that is supported in a cantilevered state.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems. A work holding device capable of holding a work rotatably around an axis of rotational symmetry while favorably supporting the work, and a printing system capable of excellently printing on the side surface of the work using the work holding device. and a printing method.

In a first aspect of the present invention, when printing is performed by relatively pressing a printing device against the side surface of a work having a shape that is rotationally symmetrical about the axis of rotational symmetry, the work can be freely rotated about the axis of rotational symmetry. The present invention relates to a work holding device for holding.
A work holding device according to a first aspect includes a holding main body, a first holding part that rotatably holds one end of a work in the axial direction of an axis of rotational symmetry with respect to the holding main body, and a second holding portion that holds the other end of the work rotatably with respect to the holding main body; a first backup member rotatably provided around a parallel axis, the first holding part holding one end of the work via a self-aligning bearing , the work being a bottle, and the first holding part The second holding part has a mouth holding member that holds the mouth part of the bottle in a state of being rotatably provided with respect to the holding main body part via a self-aligning bearing, and the second holding part holds the bottom part of the bottle. The mouth holding member has a female screw portion that can be screwed into the male screw portion provided on the mouth portion, and the female screw portion is screwed to the male screw portion of the mouth portion to hold the bottle. characterized by holding .
Another work holding device of the first aspect comprises a holding main body portion, a first holding portion that rotatably holds one end portion of a work in the axial direction of an axis of rotational symmetry with respect to the holding main body portion, and a second holding part for rotatably holding the other end of the work with respect to the holding main body, the first holding part holding the one end of the work via a self-aligning bearing and pushing the printing device; A first backup member is disposed on the opposite side of the printing device across the work piece in the pressing direction, and supports the work piece in a posture that abuts against the side surface of the work piece and is rotatable about an axis of rotational symmetry. It is characterized by comprising a second backup member that abuts on the side surface of the work at a position lower than the first backup member and supports the work in a posture that is freely rotatable about the axis of rotational symmetry.
Another work holding device of the first aspect comprises a holding main body, a first holding part that rotatably holds one end of a work in the axial direction of an axis of rotational symmetry with respect to the holding main body, a second holding part for rotatably holding the other end of the work with respect to the holding main body, the first holding part holding the one end of the work via the self-aligning bearing; to rotate the workpiece held by the first holding part and the second holding part around the axis of rotational symmetry, wherein the rotary driving part is a driving source for generating the rotational driving force and a power transmission mechanism for transmitting rotational driving force from the drive source to the first holding portion, wherein the power transmission mechanism transmits the rotational driving force from the driving source to the first holding portion and interrupts the transmission of the rotational driving force. The power transmission mechanism includes a first pulley that rotates by receiving a rotational driving force from the drive source, a second pulley that is connected to the first holding portion, the first pulley and the second pulley. a third pulley provided displaceably with respect to, an endless belt suspended over the first, second and third pulleys; and the third pulley attached in a direction separating the first and second pulleys. and an urging member that applies tension to the endless belt by urging it.

A second aspect of the present invention is a printing system for printing on a side surface of a work having a rotationally symmetrical shape about an axis of rotational symmetry, comprising: the work holding device; A first printing device for printing a first print pattern on the side surface of a work, a second printing device for printing a second print pattern on the side surface of the work held by the work holding device, and the work holding the work It is characterized by comprising a transport device for transporting 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, comprising the steps of: holding a work having a rotationally symmetrical shape about an axis of rotational symmetry with the work holding device; a first printing device and a second printing device in order; and printing a second print pattern by the second printing device on the side surface of the work held by the work holding device transported from the first printing device to the second printing device. It is characterized by

In the invention configured as described above, one end and the other end of the work are rotatably held by the first holding portion and the second holding portion, respectively, in the axial direction of the rotationally symmetrical axis. Therefore, the work is held well by the work holding device. Therefore, when the printing device prints on the side surface of the work, the side surface of the work is printed in a state in which the printing device is relatively firmly pressed against the side surface of the work. Further, even if the axis of rotational symmetry slightly deviates due to individual differences in the workpiece, the self-aligning bearing absorbs the deviation of the axis of rotational symmetry and rotates the workpiece stably.

As described above, according to the present invention, regardless of the type of workpiece having a shape that is rotationally symmetrical about the axis of rotational symmetry, it is possible to satisfactorily hold the workpiece so as to be rotatable about the axis of rotational symmetry. Good printing can be done on the side.

1 is a schematic diagram showing a schematic configuration example of a printing system for printing the side surface of a work using the first embodiment of the work holding device according to the present invention; FIG. FIG. 3 is a diagram showing configurations of a plate stage unit and an ink filling unit; FIG. 2 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 configuration of a rotation drive unit provided in the bottle holding device; Figure 4 is a side view of the bottle holding device shown in Figure 3; 4 is a graph showing eccentricity characteristics when a bottle is rotated by the bottle holding device shown in FIG. 3. FIG. It is a figure which shows 2nd Embodiment of the work holding|maintenance apparatus which concerns on this invention. It is a figure which shows 3rd Embodiment of the work holding|maintenance apparatus which concerns on this invention.

FIG. 1 is a schematic diagram showing a schematic configuration example of a printing system for printing the side surface of a work using the first embodiment of the work holding device according to the present invention. This printing system 100 can be used for articles having a rotationally symmetrical shape around an axis of rotational symmetry (marked AR in FIG. 3), such as glass containers and bottles, resin containers and bottles (hereinafter collectively referred to as The bottle B corresponds to an example of the "work" of the present invention, and the bottle holding device for holding the bottle B is the "work" of the present invention. It corresponds to an example of "work holding device". Here, an XYZ orthogonal coordinate system is set as shown in FIG. 1 in order to uniformly show the directions in each figure. For example, the XY plane can be considered as the horizontal plane and the Z axis as the vertical axis. In the following, the (-Z) direction is defined as vertically downward. Also, the dotted arrows attached to the vicinity of the constituent elements in the following figures indicate the movements of the constituent elements.

The printing system 100 comprises two sets of printing devices, a first printing device 101 and a second printing device 102, each for printing on the side Ba of a bottle B with one ink color. Therefore, this printing system 100 can perform two-color printing on the side surface Ba of the bottle B. FIG. 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 each have a plate stage unit 1, an ink filling unit 2, a transfer unit 3 and a pre-curing unit 4. As shown in FIG. These units are arranged in the above order from the (-Y) direction side to 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 conveying device 400 while being held by the bottle holding device 300. be transported. In this embodiment, the attachment and detachment of the bottle B to and from the bottle holding device 300 are performed manually by the operator at the bottle attachment/detachment station. On the other hand, in order to automate other operations, the printing system 100 further includes a control device 900 that controls the operations of each of these units.

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

Printing processing in the printing system 100 includes:
(1) Formation of an ink pattern using photocurable ink by the plate stage unit 1 and the ink filling unit 2;
(2) transferring 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 the ink by light irradiation from the temporary curing unit 4;
After executing the monochrome printing operation consisting of each step in each of the printing apparatuses 101 and 102,
(5) full curing of the ink by the main curing device 200;
is completed 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 attachment/detachment 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 mounted in this manner is held by the bottle holding device 300 so as to be rotatable about the axis of rotational symmetry, and in this state is conveyed integrally with the bottle holding device 300 to the first printing apparatus 101 by the bottle conveying device 400 . In the first printer 101, the steps (1) to (4) are performed on the bottle B while the bottle holding device 300 holds the bottle B rotatably. 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 .

FIG. 2 is a diagram showing the configuration 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. A stage 11 is attached to a base portion 13 via an alignment mechanism 12 . The alignment mechanism 12 moves the stage 11 in the XYZ directions and rotation directions around the Z-axis in accordance with a control command from the control device 900 . For example, a crossed 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 from the pedestal of the printing system 100 and is reciprocally movable along the guide rail 14 in the Y direction. More specifically, a driving mechanism (not shown) controlled by the control device 900 is connected to the base portion 13. By operating the driving mechanism, the base portion 13 moves in the (−Y) direction and the (+Y) direction. move to The position closest to the (−Y) direction (the position indicated by the solid line in FIG. 2) in the movable range of the base portion 13 is the home position of the base portion 13 .

Alignment cameras 15, 15 are arranged above the stage 11 positioned at the home position. The alignment cameras 15 and 15 take images of the peripheral edge of the plate P placed on the stage 11 or the alignment marks provided 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, thereby adjusting the position of the plate P to an appropriate position.

An ink filling unit 2 and a 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 has a nozzle 21 facing the upper surface of the plate P placed on the stage 11 passing directly below. The nozzles 21 are supplied with photocurable ink (hereinafter sometimes simply referred to as “ink”) from an ink supply unit 22 controlled by a control device 900 . The supplied ink is ejected from ejection openings provided at the lower ends of the nozzles 21 and applied to the upper surface of the plate P. As shown in FIG.

Photocurable ink is made up of a pigment as a color developer, a polymer material (including at least one of monomers and oligomers) that forms a strong polymer layer through polymerization, and active species that are generated by chemical changes upon exposure 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 rubs the surface of the plate P supplied with ink to scrape off the ink. As a result, the concave portions provided on the upper surface of the plate P are filled with the ink, and the remaining surplus ink is removed to form an ink pattern.

The plate P filled with ink in this way moves further 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 roll 30 and a motor 33 for rotating it. More specifically, the blanket roll 30 includes a blanket cylinder 31, which is, for example, a metal cylinder, and a blanket 32 wrapped around its surface, and has a generally cylindrical shape as a whole. The blanket roll 30 is rotatably supported by a frame (not shown) and driven to rotate about the central axis indicated by the dashed line in FIG. 1 by a motor 33 controlled by the control device 900 .

The blanket 32 is made of an elastic resin material, such as silicon resin, and is capable of carrying an ink pattern on its surface. The blanket 32 has a thickness sufficiently larger than the irregularities that may occur on the surface of the bottle B, which is the side surface Ba of the bottle B. As shown in FIG. As shown in FIG. 2, when the plate P placed on the stage 11 passes through the position directly below the blanket roll 30, the surface of the blanket 32 contacts the upper surface of the plate P. As shown in FIG. At this time, the ink filling the depressions of the plate P migrates to the surface of the blanket 32 . The ink pattern on the plate P is thus received by the blanket 32 .

The ink pattern once accepted (primarily transferred) by the blanket 32 is secondarily transferred to the surface of the bottle B, which is the final side surface Ba of the bottle B. As shown in FIG. Thus, the blanket 32 functions as an intermediate transfer member that temporarily carries the ink pattern to be finally transferred onto the side surface Ba of the bottle B. As shown in FIG. In this embodiment, two printing apparatuses 101 and 102 are installed to form two types of ink patterns. It corresponds to an example of "printing pattern" and "second printing pattern".

FIG. 3 is a diagram showing the structure of the bottle holding device and the 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 made of, for example, a resin material whose main material is polyethylene terephthalate (PET) or a glass material, and has a rotationally symmetrical shape about a rotationally symmetrical axis AR. In this embodiment, the body portion Bb of the bottle B is finished in a cylindrical shape, and two types of ink patterns are superimposed and printed on the surface of the body portion Bb, that is, the side surface Ba of the bottle B. FIG. Further, the inside of the bottle B can store beverages such as water, tea, juice, cosmetics, and the like. In this bottle B, a mouth portion Bc is formed on one side of the rotationally symmetrical axis AR in the axial direction X, that is, on the (+X) direction side. The mouth portion Bc referred to here is a mouth portion that roughly extends from the shoulder portion of the body portion Bb to where the bottle cap is attached. An opening is provided in the (+X) direction end face of the mouth portion Bc, and a male screw portion Bd is appropriately formed in 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 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 rotates around the rotationally symmetrical axis AR in a sideways posture. It is freely held and further rotated as appropriate.

The bottle holding device 300 has a holding body portion 330 that rotatably holds the bottle B via the first holding portion 310 and the second holding portion 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 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) from the base 333. erected above.

The first holding portion 310 has a shaft 311 extending in the X direction. The shaft 311 is rotatably supported by the first support portion 331, and a lip holding member 313 is attached to the (-X) direction end of the shaft 311 via a self-aligning bearing 312. As shown in FIG. A female screw portion is formed inside the mouth holding member 313 . For this reason, when the operator holds the bottle B and rotates the knob member 314 attached to the (+X) direction end of the shaft 311 while restricting the rotation of the bottle B, the male screw provided in the mouth portion Bc is rotated. Bd is screwed to connect the mouth holding member 313 to the sideways bottle B. As shown in FIG. Conversely, the operator can remove the lip holding member 313 from the bottle B by rotating the knob member 314 in the opposite direction while restricting the rotation of the bottle B. The manner in which the lip portion Bc is held by the lip holding member 313 is not limited to the screw structure described above.

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 while being arranged so as to coincide with the axis of the shaft 311 . A bottom holding member 322 is attached to the end of the shaft 321 in the (+X) direction. A spring member 323 is loosely inserted on the shaft 321 between the bottom holding member 322 and the (+X) side wall surface of the second support portion 332 to bias the bottom holding member 322 toward the bottom portion Be of the bottle B. As shown in FIG. Therefore, as shown in FIG. 3, the bottom holding member 322 urges and holds the bottom Be of the bottle B while the bottle B is placed in a lateral position and the mouth portion Bc is connected by the mouth holding member 313. , the axis of rotational symmetry AR of the bottle B substantially coincides with the axes of the shafts 311 and 321, so that the bottle B can freely rotate around the axis of rotational symmetry AR. On the other hand, when the operator pulls the knob member 324 attached to the (−X) direction end of the shaft 321 in the (−X) direction against the urging force of the spring member 323, the bottom holding member 322 moves toward the bottom Be of the bottle B. It becomes possible to remove the bottle B away from the .

As described above, in the bottle holding device 300, the bottle B is held by the first holding portion 310 and the second holding portion 320 so as to be rotatable around the axis of rotational symmetry AR. , and the bottle B can be rotated by driving the shaft 311 to rotate. Hereinafter, the configuration and operation of the rotary drive unit 340 will be described in detail with reference to FIGS. 3 and 4. FIG.

FIG. 4 is a perspective view schematically showing the configuration of a rotary drive unit provided in the bottle holding device. The rotation driving section 340 uses a motor 341 fixed to the first support section 331 as a “driving source” of the present invention. B is rotated 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 stretched between the pulleys 344a to 344c, and a clutch 346. The gear 343 a is attached to the rotating shaft of the motor 341 . A gear 343b meshes with the gear 343a, and a pulley 344a is connected via a clutch 346 to the gear 343b. In addition, the pulley 344a is connected to pulleys 344b and 344c by an endless belt 345. As shown in FIG. Of these, the pulley 344 b is attached to the shaft 311 and the pulley 344 c 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 the biasing force of the spring member 348. As shown in FIG. In this way, the pulley 344c is displaceable with respect to the pulleys 344a and 344b, and functions as a so-called tension pulley. is recieving. Therefore, when the clutch 346 is switched to the ON state in response to a transmission command from the control device 900, the pulley 344a rotates together with the gear 343b to transmit power to the shaft 311. FIG. As a result, the bottle B is rotationally driven around the axis of rotational symmetry AR. On the other hand, when the clutch 346 is switched to the OFF state, the power transmission is interrupted. As a result, the bottle B is maintained in a rotatable state around the rotationally symmetrical axis AR, and when the ink pattern is transferred from the blanket 32, the bottle B can be driven to rotate as the blanket 32 moves. ing.

In this manner, the bottle B is driven to rotate in a sideways posture by the rotation driving unit 340, and is driven to rotate with respect to the blanket 32. In order to support the bottle B and stabilize the posture of the bottle B, the bottle holding mechanism 340 is provided. The device 300 has two backup rollers 351, 352 as shown in FIG.

5 is a side view of the bottle holding device shown in FIG. 3. FIG. The backup rollers 351 and 352 have a shaft 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 across the bottle B in the pressing direction Y in which the side surface Ba of the bottle B is pressed against the blanket 32 of the printing device 101 or 102, that is, on the (+Y) direction side. ing. The backup roller 351 abuts on the side surface of the bottle B in the (+Y) direction, thereby restricting displacement of the bottle B in the (+Y) direction.

Also, the other backup roller 352 is arranged at a position lower than the backup roller 351 in the vertical direction Z. As shown in FIG. The backup roller 352 contacts the side surface Ba of the bottle B from below, thereby restricting displacement of the bottle B in the direction of gravity, ie, the (-Z) direction. Thus, in this embodiment, the backup rollers 351 and 352 respectively function as the "first backup member" and the "second backup member" of the invention.

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 is connected to the bottle attaching/detaching station, the first printing device 101, the second printing device 102 and the book. It is circulated and transported in the order of the curing device 200 . At the bottle attaching/detaching station, the operator manually attaches/removes the bottle B to/from the transported bottle holding device 300 . That is, when a 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 section 310 and the second holding section 320. Remove the printed bottle B 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 portion. 310 and the second holding portion 320 are held. 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 receives it and transfers the bottle holding device 300 holding the bottle B to the first printing device. 101 to perform print processing.

This print processing is realized by executing a pre-stored program by the control device 900 and causing each unit of the device to perform a predetermined operation. In this printing process, the plate P is carried into the first printing device 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 is switched to the ON state in response to the transmission command. It transmits the rotational driving force of the motor 341 . This causes the bottle B to rotate about the axis of rotational symmetry AR. The print start position of the bottle B is detected during its rotation, and the amount of rotation of the bottle B is adjusted based on the detection result, so that the bottle B is positioned so that the print start position faces the printer 101 . This positioning process may be performed based on an image obtained by imaging the bottle B with a camera, similarly to the alignment adjustment process of the plate P, or may be performed 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 this embodiment, in parallel with the alignment adjustment processing of the plate P, the positioning processing of the bottle B with respect to the printing device 101 is automatically performed. Of course, the positioning process for the bottle B may be performed in parallel with the ink pattern receiving process in the printing apparatus 101, which will be described below.

Subsequently, the stage 11 of the first printing device 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 ink IK is applied by the doctor blade 23. By scraping off the ink, the plate surface is filled with the ink. The ink pattern formed on the plate P is received by the surface of the blanket 32 by moving the stage 11 further and passing through a position directly below the rotating blanket roll 30 . After that, the bottle holding device 300 moves in the (−Y) direction and presses the printing start position of the side surface Ba of the bottle B against the surface of the blanket 32 . As a result, transfer of the ink pattern from the blanket 32 to the bottle B is started. In this transfer process, the ink pattern on the surface of the blanket 32 is sequentially transferred to the bottle B by the blanket 32 receiving the ink pattern and the bottle B rotating with each other while being in contact with each other.

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 position of contact with the backup rollers 351 and 352 as the bottle B rotates, the uncured ink is removed from the bottle. B may be transferred to backup rollers 351 and 352 . In addition, when the bottle B rotates more than once, the ink pattern on the side surface Ba of the bottle B may be re-transferred onto 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 the ink.

In order to prevent this problem, pre-curing treatment is performed by UV irradiation with a relatively low exposure dose. That is, light (ultraviolet rays) is irradiated 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 polymerizes a portion of the polymer material contained in the ink, thereby increasing the viscosity of the ink, but does not cure the entire ink. It is.

The increased viscosity of the ink reduces the adhesion to other objects, and when the side Ba of the bottle B carrying the ink comes into contact with the backup rollers 351, 352 or the blanket 32, the ink is transferred to them. This prevents it from being put away.

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 ink pattern. Then, the printing process is performed by the second printing apparatus 102 in the same manner as the first printing apparatus 101 . As a result, another ink pattern by the second printing device 102 is superimposed and printed on the already printed ink pattern. 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 the ink is not completely cured. In order to completely cure this, the main curing device 200 irradiates the bottle B with light (ultraviolet rays) having a higher output than that of the temporary curing unit 4 . This completely cures the ink and completes the print. After that, the bottle holding device 300 is returned from the main curing device 200 to the loading/unloading station while holding the bottle B. FIG. Such a series of operations are repeatedly executed.

As described above, in the present embodiment, both ends of the bottle B, that is, the mouth portion Bc and the bottom portion Be, are rotatably held by the first holding portion 310 and the second holding portion 320 in the axial direction X of the rotationally symmetrical axis AR. is doing. For this reason, as described above, not only bottles B having a cylindrical body portion Bb, but also other types of bottles, such as bottles having a rotationally symmetrical shape about an axis of rotational symmetry AR, have a side surface Ba whose outer diameter is axially symmetrical. A bottle having a shape that varies in X can also be held rotatably around the axis of rotational symmetry AR while being well supported. Therefore, the side surface Ba of the bottle B can also be printed satisfactorily.

Also, although the bottles B are mass-produced, it is practically impossible to eliminate individual differences among them. 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 is often varied 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 portion holding member 313 and the bottom portion Be, respectively, it is difficult to always rotate the bottle B stably. There is a possibility that a large amount of stress acts on the mouth portion Bc and the bottle B is 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 mouth holding member 313, the bottle B is stably rotated around the rotationally symmetrical axis AR. It is possible to prevent a large amount of stress from acting on 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 practically impossible to reduce the eccentricity of the bottle B to zero. can be stably rotated while suppressing the eccentricity of the bottle B, and the bottle B can be rotated with high reproducibility with less variation in the eccentricity characteristics. For example, when the bottle B is held by the bottle holding device 300 and rotated a plurality of times (three times in the verification experiment shown in FIG. 6) around the rotationally symmetrical axis AR, the eccentricity characteristics are measured, and the results shown in FIG. 6 are obtained.

FIG. 6 is a graph showing the eccentricity characteristics when the bottle is rotated by the bottle holding device shown in FIG. and (d) is a graph in which the eccentricity characteristics are superimposed. The horizontal axis in the figure indicates the rotational position, and the vertical axis indicates 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 shown in FIG. As can be seen from these graphs, it is possible to rotate the bottle B around the rotationally symmetrical axis AR with high reproducibility while suppressing the amount of eccentricity of the bottle B. FIG. Therefore, by performing the printing process with the printing devices 101 and 102 while the bottle B is held by the bottle holding device 300, it is possible to print while suppressing the distortion of each ink pattern. can be suppressed, and the desired image can be printed on the side surface Ba of the bottle B with excellent quality.

Furthermore, in this embodiment, 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 apparatuses 101 and 102, so highly accurate printing can be performed. . In addition, the power transmission mechanism 342 is provided with a clutch 346, and the clutch 346 is controlled to switch between transmission and transmission cutoff of the rotational driving force to follow the motor-driven rotation suitable for the positioning process and the rotation of the blanket 32 suitable for the transfer process. rotating and switching. Thus, the bottle B can be rotated in a manner suitable for the positioning process and the transfer process, and 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 "work" of the present invention, and the bottle holding device 300 corresponds to an example of the "work holding device" of the present invention. Further, the mouth portion Bc and the bottom portion Be of the bottle B correspond to examples of "one end of the work" and "the other end of the work" in the present invention, respectively. Also, the pulleys 344a to 344c respectively correspond to examples of the "first pulley", the "second pulley" and the "third pulley" of the present invention. Also, 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 "conveying device" of the present invention.

The present invention is not limited to the above-described embodiments, 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 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. For example, as shown in FIG. The two gears 349a and 349b may be attached to a clutch plate (not shown) of the clutch 346 and the shaft 311 to transmit power (second embodiment).

In the above-described embodiment, when printing is performed, transmission of the rotational driving force generated by the motor 341 is interrupted and the bottle B is driven to rotate as the blanket 32 rotates. The bottle B may be rotated synchronously with the blanket 32 by the driving force.

In the above-described embodiment, the rotation driving section 340 is provided in the bottle holding device 300 to rotate the shaft 311 to rotate the bottle B. may be configured to be driven to rotate.

In the above embodiment, the two backup rollers 351 and 352 are used to support the bottle B, but the number of backup rollers is not limited to this. The bottle B may be additionally supported by book backup rollers 353 to 356 (third embodiment). In this third embodiment, the backup rollers 353 and 354 are arranged on the opposite side of the blanket 32 across the bottle B in the pressing direction Y, that is, on the (+Y) direction side, and are arranged on the (+Y) direction side surface of the bottle B. The contact restricts displacement of the bottle B in the (+Y) direction. In addition, the remaining backup rollers 355 and 356 are arranged at positions lower than the backup rollers 353 and 354 in the vertical direction Z, and by contacting the side surface Ba of the bottle B from below, regulates the displacement of the bottle B. Thus, in this embodiment, the backup rollers 353 and 354 function as the "first backup member" of the invention, while the backup rollers 355 and 356 function as the "second backup member" of the invention. Note that if 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.

Further, in the above-described embodiment, the printing system 100 which is equipped with the two printing devices 101 and 102 and the two bottle holding devices 300 and prints the two types of ink patterns on the side surface Ba of the bottle B in superimposed relation to each other. However, the number of printing devices and bottle holding devices 300 is not limited to this, and may be one or three or more.

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, so that they are positioned relative to each other in the printing process. However, it is sufficient that these movements are relatively realized, and which device is made movable is not limited to the above and is arbitrary.

Furthermore, in the above 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, even for a cylindrical object with both ends open, or an object having an uneven surface on a generally cylindrical surface, as long as each object has a rotationally symmetrical shape about the axis of rotational symmetry, the above-described A work holding device configured in the same manner as the bottle holding device 300 can rotatably hold the work holding device, and the printing system 100 can use the work holding device to perform print processing.

The present invention relates to a work holding device in general that holds a work rotatably around the axis of rotational symmetry when printing is performed on the side surface of the work having a shape that is rotationally symmetrical around the axis of rotational symmetry, and a work holding device that holds the work. It can be applied to all printing techniques that print on the side surface of a work while holding it.

DESCRIPTION OF SYMBOLS 100... Printing system 101... 1st printing apparatus 102... 2nd printing apparatus 300... Bottle holding|maintenance apparatus 310... 1st holding part 312... Self-aligning bearing 313... Mouth holding member 320... 2nd holding part 322... Bottom holding Member 348... Spring member (biasing member)
330... Holding main body part 331... First support part 332... Second support part 333... Base 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 conveying device AR ... axis of rotational symmetry B ... bottle (workpiece)
Ba... Side (of bottle) Bc... Mouth (of bottle) Bd... Male screw part Be... Bottom (of bottle) X... Axial direction Y... Pressing direction Z... Vertical direction

Claims (8)

A workpiece holding device that holds a workpiece rotatably around the axis of rotational symmetry when printing is performed by pressing a printing device against the side surface of the workpiece that has a shape that is rotationally symmetrical about the axis of rotational symmetry. hand,
a holding body;
a first holding portion rotatably holding one end of the workpiece in the axial direction of the rotationally symmetrical axis with respect to the holding main body;
a second holding portion rotatably holding the other end of the work in the axial direction with respect to the holding main body;
a first backup member that abuts against a side surface of the work to support the work in a posture that is rotatable about the axis of rotational symmetry and that is rotatable about an axis parallel to the axis of rotational symmetry; ,
The first holding part holds one end of the work via a self-aligning bearing,
the workpiece is a bottle,
The first holding portion has a mouth holding member that holds the mouth portion of the bottle while being rotatably provided with respect to the holding body through the self-aligning bearing,
The second holding part has a bottom holding member that holds the bottom of the bottle,
The mouth holding member has a female threaded portion that can be screwed into the male threaded portion provided on the mouth portion. to hold
A workpiece holding device characterized by: The work holding device according to claim 1 ,
The work holding device, wherein the first backup member is arranged on the opposite side of the printing device with the work sandwiched therebetween in a pressing direction in which the printing device is pressed. A workpiece holding device that holds a workpiece rotatably around the axis of rotational symmetry when printing is performed by pressing a printing device against the side surface of the workpiece that has a shape that is rotationally symmetrical about the axis of rotational symmetry. hand,
a holding body;
a first holding portion rotatably holding one end of the workpiece in the axial direction of the rotationally symmetrical axis with respect to the holding main body;
a second holding portion that rotatably holds the other end of the work in the axial direction with respect to the holding main body;
The first holding part holds one end of the work via a self-aligning bearing,
A second device is arranged on the opposite side of the printing device across the work in the pressing direction against which the printing device is pressed, and is in contact with the side surface of the work to support the work in a posture rotatable about the rotationally symmetrical axis. 1 backup member,
A work holding device comprising a second backup member that abuts against 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 that is freely rotatable about the axis of rotational symmetry. The work holding device according to any one of claims 1 to 3 ,
A work holding device comprising a rotary drive section that applies a rotational driving force to the first holding section to rotate the work held by the first holding section and the second holding section around the axis of rotational symmetry. The work holding device according to claim 4 ,
The rotary drive unit has a drive source that generates the rotary drive force, and a power transmission mechanism that transmits the rotary drive force from the drive source to the first holding unit,
The power transmission mechanism includes a clutch that switches between transmission of the rotational driving force from the drive source to the first holding portion and interruption of transmission of the rotational driving force. A workpiece holding device that holds a workpiece rotatably around the axis of rotational symmetry when printing is performed by pressing a printing device against the side surface of the workpiece that has a shape that is rotationally symmetrical about the axis of rotational symmetry. hand,
a holding body;
a first holding portion rotatably holding one end of the workpiece in the axial direction of the rotationally symmetrical axis with respect to the holding main body;
a second holding portion that rotatably holds the other end of the work in the axial direction with respect to the holding main body;
The first holding part holds one end of the work via a self-aligning bearing,
a rotary drive unit that applies a rotational driving force to the first holding unit and rotates the workpiece held by the first holding unit and the second holding unit around the axis of rotational symmetry;
The rotary drive unit has a drive source that generates the rotary drive force, and a power transmission mechanism that transmits the rotary drive force from the drive source to the first holding unit,
The power transmission mechanism has a clutch that switches between transmission of the rotational driving force from the drive source to the first holding portion and interruption of transmission of the rotational driving force,
The power transmission mechanism includes a first pulley rotated by receiving the rotational driving force from the drive source, a second pulley connected to the first holding portion, and a pulley for the first pulley and the second pulley. a third pulley that is displaceable by a third pulley; an endless belt that is stretched over the first, second, and third pulleys; and separating the third pulley from the first and second pulleys. and an urging member that applies tension to the endless belt by urging it in a direction to hold the workpiece. A printing system for printing on a side surface of a workpiece having a rotationally symmetrical shape about an axis of rotational symmetry,
a workpiece holding device according to any one of claims 1 to 6 ;
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 that prints a second print pattern on the side surface of the work held by the work holding device;
A printing system, comprising: a conveying device for conveying the work holding device holding the work between the first printing device and the second printing device. A step of holding a workpiece having a rotationally symmetrical shape about an axis of rotational symmetry with the workpiece holding device according to any one of claims 1 to 6 ;
a step of transporting the work holding device holding the work to a first printing device and a second printing device in that order;
a step of printing a first print pattern by the first printing device on the side surface of the work held by the work holding device conveyed to the first printing device;
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. A printing method characterized by:

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