JP6309799B2 - Turn bar - Google Patents

Description

  The present invention relates to a turn bar that reverses the front and back of a continuous print medium being conveyed.

  A printing apparatus that performs printing on both sides of a printing paper includes an inversion unit that inverts the surface of the printed printing paper. The reversing unit generally uses a turn bar having a fixed roller arranged in a 45-degree inclined posture. In the reversing unit, if the turn bar is used once, the printing device that prints the front surface and the printing device that prints the back surface can be arranged in the L shape. Can be arranged.

  Since the above-described turn bar slides on the printing paper, it is general that a hard chrome treatment is applied to improve wear resistance. By applying the hard chrome treatment, conductivity can be obtained, but since the coefficient of friction against the printing paper is increased, there is a difference in tension before and after the turn bar. Specifically, the front surface printing apparatus side has a low tension across the turn bar, and the back surface printing apparatus side arranged on the downstream side of the front surface printing apparatus has a high tension. If the conveyance of the printing paper is started in such a state where there is a difference in tension, the tension difference is released at the time when the conveyance of the printing paper is started, and the tension is rapidly lowered. For this reason, tension variation occurs at the start of conveyance. If tension variation occurs, variation occurs in the conveyance of the printing paper, so it is important to suppress tension variation.

  Various proposals have been made to solve such problems. For example, there is a method of sticking a tape having a small coefficient of friction and high slidability to a turn bar. Such a tape having high slidability is an insulator since many tapes are mainly composed of a fluororesin. In recent years, fluororesin tapes with surface layers that are conductive and durable are commercially available. However, when the humidity is low, such as in winter, static electricity is charged to the fluororesin tape, so the slidability is poor. Become.

  Then, the following is proposed as a technique for solving this problem.

(1) A plurality of rotatable rollers are provided on the outer peripheral surface of the turn bar to reduce the frictional force (see, for example, Patent Document 1).
(2) Air is ejected from the inside of the turn bar toward the outer peripheral surface, and an air layer is formed to reduce the frictional force.

Japanese Patent No. 3869254

However, the conventional example having such a configuration has the following problems.
That is, the conventional apparatus can prevent deterioration of slidability due to static electricity, but has a problem that the structure is complicated and the cost is increased.

  This invention is made in view of such a situation, Comprising: It aims at providing the turn bar which can prevent the deterioration of the slidability resulting from static electricity cheaply, using a fluororesin tape. .

In order to achieve such an object, the present invention has the following configuration.
That is, the invention according to claim 1 is a turn bar that contacts a surface of a continuous print medium being conveyed and inverts the front and back, and has a cylindrical shape and is electrically grounded. Fluorine resin tape that is made by attaching a fluororesin tape having an adhesive property and an insulating adhesive layer to the turn bar main body part that contacts the print medium on the adhesive layer side. And an exposed portion where a part of the surface of the turn bar main body is exposed, and the exposed portion and the fluororesin layer of the fluororesin tape pasting portion. comprising electrically conductive is not conductive member, is constituted of the fluorine resin tape putting portion is adhered to the fluorine resin tape sliding direction of the printing medium at a predetermined distance , The exposed portion, the is composed of a portion of the fluorine predetermined spacing resin tape, the print medium is a non-contact, is constructed by pasting the conductive members linearly in the axial direction of the turn bar body It is characterized by being.

[Operation / Effect] According to the first aspect of the present invention, since the fluororesin tape is attached to the turn bar body to form the fluororesin tape attaching portion, the friction coefficient of the turn bar can be reduced. Furthermore, since the fluororesin tape attaching portion and the exposed portion are electrically connected by the conductive member, static electricity can be prevented from accumulating on the fluororesin tape. Therefore, the deterioration of the slidability due to static electricity can be prevented at a low cost while using the fluororesin tape. In addition, the fluororesin tape affixed portion and the exposed portion are configured by affixing a fluororesin tape in a spiral manner in the direction in which the print medium being conveyed slides on the turn bar body, The part which does not contact with a fluororesin tape arises. Therefore, since the tension is easily transmitted before and after the direction change, the difference in tension between the front and rear feeding sides and the receiving side can be reduced.

  Further, in the present invention, the fluororesin tape affixing portion is configured by adhering the fluororesin tape so as to cover a surface on which the turn bar main body and the printing medium slide, and the exposed portion is A region where the fluororesin tape is not affixed is formed along the axial direction of the turn bar body, and the conductive member is affixed to the fluororesin tape and the exposed portion. Preferred (claim 2).

  Since the fluororesin tape is affixed so as to cover the surface on which the turn bar main body and the print medium slide, the fluororesin tape affixing part and the exposed part are configured.

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Further, in the present invention, the fluororesin tape affixing unit is configured such that a conveyance direction in which the print medium is redirected and conveyed is parallel to an inclination of the affixing direction of the fluororesin tape. The fluororesin tape is preferably affixed (Claim 3 ).

  Since the attachment direction of the fluororesin tape is inclined so as to be parallel to the print medium for which the direction is changed, the portion where the print medium for which the direction is changed does not contact can be lengthened. Accordingly, since the tension is more easily transmitted before and after the direction change, the difference in tension between the front and rear feeding sides and the receiving side can be further reduced.

Moreover, in this invention, it is preferable that the said electroconductive member is an electroconductive tape (Claim 4 ).

  Since the conductive member is a conductive tape, it can be produced inexpensively and easily. In addition, the fluororesin tape can be prevented from turning up.

According to the turn bar according to the present invention, the fluororesin tape is affixed to the turn bar main body to form the fluororesin tape affixing portion, so that the friction coefficient of the turn bar can be reduced. Furthermore, since the fluororesin tape attaching portion and the exposed portion are electrically connected by the conductive member, static electricity can be prevented from accumulating on the fluororesin tape. Therefore, the deterioration of the slidability due to static electricity can be prevented at a low cost while using the fluororesin tape. In addition, the fluororesin tape affixed portion and the exposed portion are configured by affixing a fluororesin tape in a spiral manner in the direction in which the print medium being conveyed slides on the turn bar body, The part which does not contact with a fluororesin tape arises. Therefore, since the tension is easily transmitted before and after the direction change, the difference in tension between the front and rear feeding sides and the receiving side can be reduced.

1 is a side view illustrating an overall configuration of an inkjet printing system according to an embodiment. It is a side view which shows schematic structure of a surface printing apparatus and a back surface printing measure. It is a top view which shows schematic structure of an inversion apparatus. It is a side view of the turn bar which concerns on Example 1. FIG. It is a side view of the turn bar which concerns on Example 2. FIG. FIG. 6 is a plan view showing a positional relationship between a turn bar and continuous paper in Example 2. It is a schematic diagram which shows the example of a fluctuation | variation of the tension | tensile_strength with each Examples 1, 2 and a prior art example. It is a graph which shows the fluctuation | variation of the tension from the conveyance start in a prior art example. 10 is a graph showing a variation in tension from the start of conveyance in Example 2.

  As an apparatus provided with the turn bar of the present invention, an ink jet printing system 1 will be described as an example with reference to FIG.

  The inkjet printing system 1 includes a paper feeding unit 3, a front surface printing device 5, a reversing device 7, a back surface printing device 9, and a paper discharge unit 11.

  The paper supply unit 3 holds the roll-shaped continuous paper WP so as to be rotatable about a horizontal axis, and unwinds and supplies the continuous paper WP to the front surface printing unit 5. The surface printing apparatus 5 is an ink jet printing apparatus that forms an image by ejecting ink droplets, and performs printing on the surface of the continuous paper WP. The reversing device 7 includes a turn bar described later, and reverses the back surface of the continuous paper WP upward. The back surface printing device 9 has the same configuration as the front surface printing device 5 and performs printing on the back surface of the continuous paper WP. The paper discharge unit 11 winds the continuous paper WP processed by the front surface printing device 5 and the back surface printing device 9 around a horizontal axis.

  The front surface printing device 5 and the back surface printing device 9 will be described with reference to FIGS. 1 and 2. FIG. 2 is a side view showing a schematic configuration of the front surface printing apparatus and the back surface printing measure.

  The front surface printing apparatus 5 includes a capturing unit 13, a plurality of transport rollers 15, a drying unit 17, an inspection unit 19, a driving roller 21, and a nip roller 23 in order. Among the plurality of transport rollers 15, a plurality of ink jet heads 25 are arranged between the capturing unit 13 and the drying unit 17. Each inkjet head 25 ejects ink droplets and prints an image on the surface of the continuous paper WP.

  The take-in unit 13 includes a driving roller 21 and a nip roller 23, an edge position control unit 27, a driving roller 21 and a nip roller 23 in this order from the side on which the continuous paper WP is fed. The edge position control unit 27 automatically corrects the position when the continuous paper WP meanders in the width direction (the front side of the paper in FIG. 2) so that the continuous paper WP is appropriately conveyed. That is, the taking-in unit 13 keeps the edge position constant while taking in the continuous paper WP with the driving roller 21 and the nip roller 23.

  The drying unit 17 includes a plurality of transport rollers 15 and a heat drum 29. The heat drum 29 has a built-in heater and is driven to rotate according to the conveyance of the continuous paper WP. The heat drum 29 heats and dries the ink droplets discharged onto the continuous paper WP.

  The inspection unit 19 is disposed between the driving roller 21 and the nip roller 23 on the most downstream side and the drying unit 19. The inspection unit 19 inspects print defects such as dirt and missing in the print image formed on the continuous paper WP.

  In the configuration described above, tension sensors TP1 to TP4 are arranged at four locations on the conveyance path of the continuous paper WP. The tension sensor TP1 measures the tension of the continuous paper WP located downstream of the driving roller 21 and the nip roller 23 located upstream of the take-in unit 13 and upstream of the edge position control unit 27. The tension sensor TP2 measures the tension of the continuous paper WP located on the downstream side of the capturing unit 13 and on the upstream side of the most upstream ink jet head 25. The tension sensor TP3 measures the tension of the continuous paper WP located on the downstream side of the transport roller 15 on the downstream side in the drying unit 17. The tension sensor TP4 measures the tension of the continuous paper WP located on the upstream side of the driving roller 21 and the nip roller 23 on the upstream side in the take-in portion 13. The tension signals output from these tension sensors TP1 to TP4 are output to a control unit (not shown) and used for driving control of the driving roller 21 and the heat roller 29 operated for transporting the continuous paper WP.

  The back surface printing device 9 has the same configuration as the above-described front surface printing device 5 except that the continuous paper WP is received from the front surface printing device 5 and the printing surface is the back surface of the continuous paper WP.

  Here, the reversing device 7 will be described with reference to FIG. FIG. 3 is a plan view showing a schematic configuration of the reversing device.

  The reversing device 7 includes two turn bars 31 and one roll bar 33. The reversing device 7 is for realizing a so-called “I-type” arrangement in which the printing devices 5 and 9 are arranged in series, and the continuous paper WP conveyed with the surface S1 facing up from the right side in FIG. Are turned upside down and conveyed with the back surface S2 on the left side in FIG. The two turn bars 31 do not rotate around the major axis, and are inclined at an angle of 45 degrees in a plan view with respect to the transport direction of the continuous paper WP, and in the height direction (in the rearward direction on the paper surface of FIG. 3). They are arranged so as to form an angle of 90 degrees in a separated positional relationship. Each turn bar 31 is fixed to the device at both ends.

  Here, if the lower one of the two turn bars 31 is the turn bar 31u and the upper one is the turn bar 31d, the continuous paper WP is conveyed as follows.

  The continuous paper WP conveyed with the front surface S1 as the upper surface is reversed from the upper edge of the turn bar 31u to the left side in the conveyance direction through the left edge and the lower edge (downward in FIG. 3), and at this time, the back surface S2 is set as the upper surface. The The continuous paper WP is reversed by the roll bar 33, and at this time, the surface S1 is the upper surface. Then, the turn bar 31d is reversed from the upper edge to the left side in the transport direction through the right edge and the lower edge (left side 9 in FIG. 3), and at this time, the back surface S2 is the upper surface.

  Below, the Example of the turn bar 31 mentioned above is described in detail.

  Hereinafter, Embodiment 1 of the present invention will be described with reference to FIG. FIG. 4 is a side view of the turn bar according to the first embodiment.

  The turn bar 31 according to the first embodiment includes a turn bar main body 35, a fluororesin tape 37, an exposed portion 39, and a conductive tape 41.

  The turn bar body 35 is made of a conductor and has a cylindrical shape. The turn bar main body 35 is electrically grounded via the reversing device 7. The fluororesin tape 37 is formed by laminating a fluororesin layer 43 and an adhesive layer 45. The fluororesin layer 43 is processed to have conductivity, and the adhesive layer 45 is insulative and adhesive. Examples of the fluororesin tape 37 include an ultra tape manufactured by Sumitomo 3M Limited. The fluororesin tape 37 has a continuous paper WP, an upper edge (upper side in FIG. 4), and a side edge (upper side in FIG. 4) in a state where the turn bar 31 is attached to the reversing device 7 out of the entire outer circumference of the turn bar main body 35. It is affixed in the major axis direction where the back side of the paper surface and the lower edge (lower side in FIG. 4) contact. In other words, the fluororesin tape 37 is affixed to the outer peripheral surface of the turn bar main body 35 so as to cover the surface on which the turn bar main body 35 and the continuous paper WP slide. However, the fluororesin tape 37 is not affixed to a part of the outer peripheral surface of the turn bar main body 35 that is not in contact with the continuous paper WP. This portion is formed along the long axis direction of the turn bar main body 35, and this constitutes the exposed portion 39.

  The fluororesin tape 37 described above corresponds to the “fluororesin tape attaching portion” in the present invention.

  The conductive tape 41 is affixed along the major axis direction of the turn bar main body 35 so as to cover the exposed portion 39 and the sides of the fluororesin tape 37 facing each other on the outer peripheral surface of the turn bar main body 35. . As a result, the surface of the fluororesin tape 37 is electrically connected to the exposed portion 39 via the conductive tape 41, so that the fluororesin tape 37 is electrically grounded.

  The conductive tape 41 described above corresponds to the “conductive member” in the present invention.

  According to the turn bar 31 according to the first embodiment, since the fluororesin tape 37 is attached to the turn bar main body 35, the friction coefficient of the turn bar 31 with respect to the continuous paper WP can be reduced. Furthermore, since the fluororesin tape 37 and the exposed portion 39 are electrically connected by the conductive tape 41, it is possible to prevent static electricity from accumulating on the fluororesin tape 37. Therefore, while using the fluororesin tape 37, the deterioration of the slidability of the continuous paper WP due to static electricity can be prevented at a low cost.

  Further, since the fluororesin tape 37 is attached so as to cover the surface on which the turn bar main body 35 and the continuous paper WP slide, the turn bar 31 can be easily formed.

  Next, Embodiment 2 of the present invention will be described with reference to FIGS. FIG. 5 is a side view of the turn bar according to the second embodiment, and FIG. 6 is a plan view showing the positional relationship between the turn bar and the continuous paper according to the second embodiment.

  The turn bar 31 </ b> A according to the second embodiment includes a turn bar main body 35, a fluororesin tape 37, an exposed portion 39, and a conductive tape 41.

  The turn bar main body 35 has the same configuration as that of the first embodiment described above. The fluororesin tape 37 having the same structure as that of the first embodiment is attached to the outer peripheral surface of the turn bar body 35 in the sliding direction of the continuous paper WP at a predetermined interval. The fluororesin tape 37 may be attached so as to be spiral in one continuous state when wound around the turn bar main body 35, for example, or separated into strips, each strip being continuous. You may make it paste so that a helical may be comprised. When the strip is separated into strips, the end of the strip may be separated from the start of the next strip, but it is preferable that the portion is a portion where the continuous paper WP does not slide. The exposed portions 39 are formed at predetermined intervals sandwiched by the fluororesin tape 37.

  The fluororesin tape 37 described above corresponds to the “fluororesin tape attaching portion” in the present invention.

  The conductive tape 41 is affixed along the major axis direction of the turn bar body 35 on the exposed portion 39 and the side surface of the fluororesin tape 37 where the continuous paper WP does not slide. As a result, the surface of the fluororesin tape 37 is electrically connected to the exposed portion 39 via the conductive tape 41, so that the fluororesin tape 37 is electrically grounded.

  The conductive tape 41 described above corresponds to the “conductive member” in the present invention.

  According to the turn bar 31A according to the second embodiment, the same effects as those of the first embodiment described above can be obtained. Further, since the turn bar 31A according to the second embodiment is configured by affixing the fluororesin tape 37 in a spiral shape, a portion where the continuous paper WP does not contact the fluororesin tape 37 occurs. Therefore, since the tension is easily transmitted before and after the direction change, there is an effect that the difference in tension between the front and rear feeding sides and the receiving side can be reduced.

  Moreover, it is preferable to stick the fluororesin tape 37 on the above-described turn bar 31A under the conditions as shown in FIG.

  In the turn bar 31A, the fluororesin tape 37 is attached in the sliding direction of the continuous paper WP, but the fluororesin is parallel to the transport direction in which the continuous paper WP is redirected and transported by the turn bar 31A. Tape 37 is affixed.

  According to such a configuration, since the attachment of the fluororesin tape is inclined so as to be parallel to the continuous paper WP whose direction is changed, the portion where the continuous paper WP does not contact can be lengthened when the direction is changed. . Accordingly, since the tension is more easily transmitted before and after the direction change, the difference in tension between the front and rear feeding sides and the receiving side can be further reduced.

  Reference is now made to FIG. FIG. 7 is a schematic diagram showing a variation example of the tension between the first and second embodiments and the conventional example.

  In FIG. 7, reference numeral L1 is the first embodiment, reference numeral L2 is the second embodiment, and reference numeral L3 is a conventional example. TP3 is a tension signal from the tension sensor TP3 of the front surface printing apparatus 5, and TP4 is a tension signal from the tension sensor TP4 of the back surface printing apparatus 9.

  In Example 1 (symbol L1), the influence of the frictional force due to static electricity is reduced compared to the conventional example, so that the tension difference between the sending side (TP3) and the receiving side (TP4) is different from that in the conventional example (symbol L3). It is getting smaller. Further, in Example 2 (symbol L2), the influence of the frictional force due to static electricity is reduced as compared with the conventional example, and the tension is more easily transmitted by the portion not in contact with the fluororesin tape 37. The tension difference is smaller than that of the conventional example (reference numeral L3) and changes gradually.

  Reference is now made to FIGS. FIG. 8 is a graph showing a variation in tension from the start of conveyance in the conventional example, and FIG. 9 is a graph showing a variation in tension from the start of conveyance in the second embodiment. The conventional example referred to here is the turn bar 31 constituted only by the turn bar main body 35 to which the fluororesin tape 37 and the conductive tape 41 are not attached in the first and second embodiments.

  In these graphs, the vertical axis represents tension and the horizontal axis represents time. The horizontal axis represents 1 second because one step is 50 milliseconds. For example, 1 second is a distance by which the continuous paper WP is transported by about 10 m. In addition, 0 on the horizontal axis indicates a point in time when conveyance of the continuous paper WP is started.

  As is apparent from FIG. 8, in the conventional example, it can be seen that the continuous paper WP is conveyed with a large variation in tension immediately after the start of conveyance.

  On the other hand, as can be seen from FIG. 9, according to the second embodiment, it is understood that the variation in tension immediately after the start of conveyance is suppressed and the continuous paper WP is conveyed. Although not shown, it has been confirmed that even in Example 1 described above, tension variation can be suppressed more than in the conventional example.

  From the above two graphs, it can be clearly seen that the present invention is effective for the conventional example.

  The present invention is not limited to the above embodiment, and can be modified as follows.

  (1) In each of the above-described embodiments, the printing medium is the continuous paper WP. However, in the present invention, the printing medium is not limited to paper. For example, a film is mentioned as another printing medium.

  (2) In each of the embodiments described above, the turn bar 31 in the reversing device 7 that realizes a so-called I-type printing device in which two printing devices are arranged in series has been described as an example. The present invention can also be applied to the turn bar 31 in the reversing device 7 that realizes a so-called L-type printing device arranged in the above.

  (3) In each Example mentioned above, the electroconductive tape 41 was illustrated as an electroconductive member. However, in the present invention, the conductive member is not limited to the conductive tape 41, and any material can be used as long as it can electrically connect the fluororesin tape 37 and the turn bar body 35. Also good. For example, one end of the conductive thin plate may be soldered to the turn bar body 35 and the other end may be in contact with the surface of the fluororesin tape 37.

  (4) In each of the above-described embodiments, the turn bar 31 of the reversing device 7 in the inkjet printing system 1 is taken as an example, but the present invention is not limited to the printing method.

1 ... Inkjet printing system.
WP ... Continuous paper 5 ... Front surface printing device 7 ... Reversing device 9 ... Back surface printing device 13 ... Capture section TP1 to TP4 ... Tension sensor 31 (31u, 31d) ... Turn bar 33 ... Roll bar S1 ... Front surface S2 ... Back surface 35 ... Turn bar body 37 ... Fluororesin tape 39 ... Exposed part 41 ... Conductive tape 43 ... Fluororesin layer 45 ... Adhesive layer

Claims (4)

A turn bar that contacts the surface of a continuous print medium being conveyed and reverses the front and back,
A turn bar body that is cylindrical and electrically grounded;
Fluorine resin tape affixed with a fluororesin tape having a conductive fluororesin layer and an insulating adhesive layer on the adhesive layer side to the portion of the turn bar body that contacts the print medium Attached part,
The fluororesin tape is not affixed, and an exposed portion exposing a part of the surface of the turn bar body,
A conductive member that electrically connects the exposed portion and the fluororesin layer of the fluororesin tape attaching portion;
Equipped with a,
The fluororesin tape affixing part is configured by affixing the fluororesin tape in a sliding direction of the print medium with a predetermined interval,
The exposed portion is constituted by a predetermined interval portion of the fluororesin tape,
A turn bar characterized in that the print medium is non-contact, and the conductive member is attached linearly in the axial direction of the turn bar main body . The turn bar according to claim 1, wherein
The fluororesin tape affixing part is configured by affixing the fluororesin tape so as to cover a surface on which the turn bar main body and the printing medium slide.
In the exposed portion, a region where the fluororesin tape is not attached is formed along the axial direction of the turn bar body,
A turn bar characterized in that the conductive member is attached to the fluororesin tape and the exposed portion. The turn bar according to claim 1 , wherein
The fluororesin tape affixing unit is configured such that the transport direction in which the print medium is redirected and transported is parallel to the inclination of the affixing direction of the fluororesin tape. A turn bar characterized in that is pasted. The turn bar according to any one of claims 1 to 3 ,
The turn bar, wherein the conductive member is a conductive tape.

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