JP2014141339A - Web conveying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a web conveying device capable of regulating a travel position in a width direction of a web to perform stable conveyance and suppressing damage occurring at both side end parts of the web.SOLUTION: A web conveying device has: a buffer area 8 in which a web W is sagged; sag amount detection means for the web W; and carrying-in means for carrying the web W in the buffer area 8. The web conveying device includes: web buffer means for controlling a conveying amount of the web W by the carrying-in means depending on an output of the sag amount detection means; guide means having multiple guide shafts 11, drive means for rotating the guide shafts 11, a screw shaft 12, and a pair of edge guides 10 arranged at the substantially same interval as width of the web W conveyed; detection means for detecting tension of the web W; and tension applying means having control means for controlling the tension applied depending on an output of the detection means, in this order from an upstream side of a web conveying path. A rotation direction of the guide shafts 11 is the same direction as the conveying direction of the web W.

Description

  The present invention relates to a web conveyance device.

  2. Description of the Related Art An image forming system (printing apparatus) including a web conveyance device that continuously conveys a recording medium (hereinafter referred to as “web”) that is a long continuous belt-like sheet is known.

  When transporting a web that does not have a feed hole with a transport device composed of transport rollers, it is necessary to control the web tension, travel position, etc. during high-speed transport with high precision. There has been proposed a printing apparatus provided with a conveying device for performing stably (see, for example, Patent Document 1).

  Patent Document 1 discloses a printing unit that records and forms an image on a web, a pre-printing web control unit that controls a web traveling position and tension on the upstream side in the web conveyance direction with respect to the printing unit, and the printing unit. Describes an apparatus including a web travel position downstream of the web conveyance direction and a post-printing web control means for controlling tension.

  Moreover, the conveyance apparatus of patent document 1 is provided with the accumulation | storage part which gives a slack to a web, and the guide member which regulates the edge position of the web conveyed, and a guide member acts with respect to the web in the slack state in the accumulation | storage part. For this reason, it is described that the traveling position of the web in contact with the guide member can be easily corrected.

  In the web conveyance device, as a member for regulating the position in the width direction of the web (direction perpendicular to the conveyance direction), for example, as shown in FIG. A shaft having the provided structure is used.

  As shown in FIG. 7, the web W conveyed in the direction of the arrow may be in contact with the edge guides 30 arranged at substantially the same interval as the width of the web W, thereby damaging both side end portions 33. . In particular, as the tension applied to the web W is increased, the effect of regulating the traveling position in the width direction by the edge guide 30 is lowered, and further, damage (galling) of the side end portions 33 is increased.

  In general, a guide member of a conveying apparatus as shown in Patent Document 1 includes a plurality of shafts. Specifically, the configuration is as shown in FIG. 3, and the rigidity of the web W is improved by passing the web W between the plurality of shafts 11 in an S shape. The edge guide 10 that regulates the width direction has a hole that fits into the groove of the screw shaft 12 in which a spiral groove is formed, and moves in the width direction by rotating the screw shaft 12. It is possible.

  As described in Patent Document 1, the tension of the web W carried into the guide portion is reduced by forming slack in the web in the accumulation portion upstream of the guide member. However, in the guide member configured as shown in FIG. 3, the web is tensioned by passing while abutting against a plurality of shafts, and it is difficult to suppress damage occurring at both ends of the web. There is.

  SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a web transport device that regulates the travel position of the web in the width direction and performs stable transport and can suppress damage that occurs at both ends of the web.

  In order to solve the above-described problems, a web transport device according to the present invention includes a storage unit that provides a slack to a web, a slack amount detection unit that detects a slack amount of the web in the storage unit, and the web to the storage unit. Web buffer means for controlling the amount of web conveyed by the carry-in means in accordance with the output of the slack quantity detection means; a plurality of guide shafts; a drive means for rotating the guide shaft; and a screw. A shaft and a guide means having a pair of edge guides arranged at substantially the same interval as the width of the web to be conveyed, a detection means for detecting the tension of the web, and an output according to the output of the detection means Tension applying means having control means for controlling tension, and in this order from the upstream side on the conveyance path, and the rotation direction of the guide shaft is A web transport apparatus which is a same direction as the conveying direction of the probe.

  According to the web conveyance device of the present invention, it is possible to provide a web conveyance device capable of restricting the traveling position in the width direction of the web and performing stable conveyance and suppressing damage occurring at both end portions of the web.

It is a schematic diagram of the cross section which shows an example of a structure of the web conveyance apparatus of this embodiment. It is a perspective view which shows an example of the carrying-in means of the web conveyance apparatus of this embodiment. It is a perspective view which shows an example of the conventional guide means. It is a perspective view which shows an example of the guide means of the web conveyance mechanism of this embodiment. It is a top view which shows an example of the guide means of the web conveyance mechanism of this embodiment. It is a flowchart which shows an example of control of the web conveyance mechanism of this embodiment. It is a figure which shows an example of the member which regulates the position of the width direction of a web.

  Hereinafter, a web conveyance device according to the present invention will be described with reference to the drawings. It should be noted that the present invention is not limited to the embodiments of the examples shown below, and other embodiments, additions, modifications, deletions, and the like can be changed within a range that can be conceived by those skilled in the art. Any aspect is included in the scope of the present invention as long as the operations and effects of the present invention are exhibited.

The web conveyance device according to the present embodiment configures, for example, a printing system that forms an image on the web to be conveyed, and sends the web sent from the upstream web supply device, the preprocessing device, or the like to the downstream image forming unit. Transport.
The web to be conveyed is often paper, but is not limited to paper, and may be, for example, a plastic film or cloth.

FIG. 1 shows an example of the configuration of the web conveyance device of the present embodiment.
As shown in FIG. 1, the web conveyance device according to the present embodiment includes a storage unit 8 that gives a slack to the web W, a slack amount detection unit 9 that detects a slack amount of the web W in the storage unit 8, and a web to the storage unit 8. A web buffer means for carrying W, a web buffer means for controlling the carry amount of the web W by the carry-in means in accordance with the output of the slack quantity detecting means 9, a plurality of guide shafts 11, and a drive for rotating the guide shafts 11; Means (not shown), a screw shaft 12, and a guide means having a pair of edge guides 10 arranged at substantially the same interval as the width of the web W to be conveyed, a detecting means for detecting the tension of the web, Tension applying means having control means for controlling tension applied according to the output of the detecting means is provided in this order from the upstream side of the web conveyance path.
The rotation direction of the guide shaft 11 is the same direction as the conveyance direction of the web W.

  The guide roller 1 includes a feed-in roller 3, a nip roller 4, and arms 5 a and 5 b that rotate a web W fed from a web supply device and a pre-processing device arranged upstream of the printing system by a driving force of a motor 2. It feeds into the said carrying-in means to have.

The structure of the said carrying-in means is shown in FIG.
As shown in FIG. 2, the carry-in means includes a plurality of nip rollers 4 that press the web W against the feed-in roller 3 in a direction (width direction) perpendicular to the web conveyance direction. The number of nip rollers 4 can be selected as appropriate.

The nip roller 4 is incorporated so as to be able to be driven and rotated by the arm 5b, and the arm 5b is attached to the arm 5a so as to be able to swing and rotate.
The arm 5a is supported by the two shafts 6 and can move in the width direction of the web W. The arm 5 b presses the nip roller 4 against the feed-in roller 3 by the force of the spring 7.

The web W is fed into the accumulating unit 8 by the carrying-in means and forms a slack.
The amount of slackness of the web W in the accumulation unit 8 is detected by a plurality of sensors (light projecting / light receiving sensors) which are the slackness amount detecting means 9. The rotational speed of the feed-in roller 3 is controlled in accordance with ON / OFF of the sensor, and the amount of web slack formed in the accumulating unit 8 is controlled to be constant by controlling the conveyance amount of the web W. Is done.

The web W that has passed through the storage unit 8 is fed into the guide means.
The structure of the guide means is shown in FIGS.
As shown in FIG. 4, a pair of edge guides 10 movably supported by two guide shafts 11 are disposed at both ends in the width direction of the web W. The web W passes in an S shape between the two guide shafts while abutting against a part of the two guide shafts. This pass improves the rigidity of the web W.

  The edge guide 10 has a groove that engages with a helical groove on the outer peripheral surface of the screw shaft 12, and can be moved in the width direction of the web by rotating the screw shaft 12. By rotating the screw shaft 12, the position of the edge guide 10 is moved according to the width of the web W to be conveyed, and the distance between the pair of edge guides 10 is made substantially the same as the width of the web.

  The edge guide 10 includes a bearing 22 such as a bottom bracket (BB) that rotatably supports the guide shaft 11.

  The frame 23 shown in FIG. 5 includes a bearing 24 such as a bottom bracket (BB) that rotatably supports the guide shaft 11 and the screw shaft 12.

Drive means for rotating the guide shaft 11 is disposed outside the frame 23. The drive means includes a guide shaft drive motor 25, a belt 26 that transmits the drive force of the guide shaft drive motor 25, and a pulley 27.
The plurality of guide shafts 11 are driven by the driving means and rotate in the same direction as the web W conveyance direction.

The rotational speed of the guide shaft drive motor 25 is determined by the reduction ratio between the guide shaft drive motor 25 and the guide shaft 11, the outer diameter of the guide shaft 11 and the maximum conveyance speed of the web W, and is controlled by a control means (not shown). .
Specifically, the rotation speed of the guide shaft drive motor 25 is selected so that the outer peripheral speed of the guide shaft 11 to be rotated is faster than the conveyance speed of the web W, and the rotation speed is controlled by the control means.

By rotating all of the plurality of guide shafts 11 provided in the apparatus in the same direction as the conveyance direction of the web W, it is possible to reduce the tension generated in the web W by passing while contacting the guide shaft 11. Damage occurring at the end can be suppressed.
Furthermore, the tension of the web W can be sufficiently reduced by rotating the guide shaft 11 with the driving means so that the outer peripheral speed of the guide shaft 11 is faster than the conveying speed of the web W. The damage received by the edge guide 10 at both end portions can be reduced.

Here, when the speed ratio represented by “(guide shaft outer circumference measure) ÷ (web transport speed)” is changed, the results of evaluating the transport of the web W and the state of both end portions are shown in Table 1 below. .
The “web transport speed” means the maximum speed during transport of the web transport device.

As shown in Table 1, when the speed ratio was 1.0 or less, deformation (galling) was observed at the edge of the web, but when the speed ratio was 1.1 or more, There is no damage or deformation.
Further, meandering in the width direction of the web W is confirmed when the speed ratio is 1.0 or less, and even when the speed ratio is 1.1, meandering of 1 to 2 mm is confirmed.
Furthermore, it was confirmed that when the speed ratio is 2.2 or more, sagging occurs downstream of the guide means, and the running of the web W becomes unstable.

  From the above results, the guide shaft 11 is rotated by the driving means so that the outer peripheral speed of the guide shaft 11 is 1.2 to 2.0 times the maximum value of the conveyance speed of the web W. It can be seen that the traveling position is regulated and stable conveyance is possible, and damage occurring at both side edges of the web can be suppressed.

The tension generated by the web W coming into contact with the guide shaft 11 is also affected by the coefficient of friction between the web W and the guide shaft 11. The results shown in Table 1 above are results when a stainless steel guide shaft 11 and a paper web are used. The coefficient of friction between stainless steel and paper is about 0.3.
The guide shaft 11 is generally made of metal from the viewpoint of shape stability and durability. The coefficient of friction between the metal guide shaft 11 and the paper web is usually in the range of about 0.2 to 0.4, and if the guide shaft 11 is made of metal, a suitable speed based on the results in Table 1 above. It is considered that the same effect can be obtained in the ratio range.

  Therefore, in addition to the outer peripheral speed of the guide shaft 11 being 1.2 to 2.0 times the maximum value of the conveyance speed of the web W, the guide shaft 11 is preferably made of metal.

The rotation of the guide shaft 11 is preferably started before the web W is conveyed to the guide means. Since the rotation speed of the guide shaft 11 can be controlled without a load before the web W is conveyed, the control of the drive source can be simplified.
In addition, since the conveyance amount of the web W by rotation of the guide shaft 11 is very small, rotation of the guide shaft 11 does not affect the driving | running | working of the web W which has been conveyed.

FIG. 6 shows a flowchart of the rotation control of the guide shaft 11 in the guide means.
As shown in FIG. 6, first, at the stage of turning on the power (S01), it is determined whether or not the web W can be conveyed (S02). If the web W can be transported, the web transport speed Vp is monitored (S03), and when Vp = 0 is not reached, the outer circumference measure Vg of the guide shaft 11 is set as Vg = a × Vp (S04). Here, a is a value set in the range of 1.2 to 2.0, and the user can set an arbitrary value.
While the guide shaft 11 is rotated at the above-described outer peripheral speed of Vg = a × Vp, the web conveyance speed Vp is monitored (S05), and the rotation of the guide shaft 11 is performed when Vp = 0, that is, until the web conveyance is stopped. Continue driving. When Vp = 0, the rotational drive of the guide shaft 11 is stopped (S06).

Note that the guide shaft outer peripheral speed Vg obtained in step S04 is a maximum transport speed (Vpmax) defined in the transport device even if the guide shaft outer peripheral speed Vg is a value that is appropriately set according to the actually detected web transport speed Vp. There may be.
Further, when the power source in step S01 is turned on, the rotation of the guide shaft 11 may be started by setting Vg = a × Vpmax.

As described above, in the guide means, the web W is transported to the subsequent pre-measure 13 shown in FIG.
In the pre-measure 13, a narrow gap is formed by two shafts, and foreign matters attached to the web W are removed by passing through the narrow gap.

Next, the web W is conveyed to the adjusting roller 14.
The adjustment roller 14 is an eccentric roller that is not driven to rotate with respect to the web W, and the conveyed web W is pressed by the pressure roller 16 with the pressing force of the plate spring 15.
By changing the rotational position of the adjusting roller 14 by driving the motor 17, the force pressed by the pressure roller 16 can be changed.

Subsequently, the web W is conveyed to a downstream tension applying unit.
The tension applying means includes detection means for detecting the tension of the web W and control means for controlling the tension applied according to the output of the detection means.

A specific mechanism of the tension applying means includes a swingable and rotatable dancer roller 18 having one end suspended by a spring 19 and an angle detecting means for the dancer roller 18 (not shown).
The control means (not shown) controls the rotation angle of the upstream adjustment roller 14 in accordance with the output of the angle detection means. By controlling the rotation angle of the adjusting roller 14 by the control means, the angle of the dancer roller 18 is controlled, and as a result, the tension of the web W downstream (downstream) of the dancer roller 18 can be kept constant.

W web 3 feed-in roller 4 nip roller 5 arm 8 accumulating section 9 slack amount detecting means (sensor)
DESCRIPTION OF SYMBOLS 10 Edge guide 11 Guide shaft 12 Screw shaft 22 Bearing 24 Bearing 25 Guide shaft drive motor 26 Belt 27 Pulley

JP 2001-335206 A

Claims (5)

An accumulating unit that gives a slack to the web; a slack amount detecting unit that detects a slack amount of the web in the accumulating unit; and a loading unit that carries the web into the accumulating unit, according to the output of the slack amount detecting unit Web buffer means for controlling the amount of web conveyed by the carry-in means;
A guide means having a plurality of guide shafts, a drive means for rotating the guide shaft, a screw shaft, and a pair of edge guides arranged at substantially the same interval as the width of the web to be conveyed;
A detecting means for detecting the tension of the web, and a tension applying means having a control means for controlling the tension applied according to the output of the detecting means, are provided in this order from the upstream side of the web conveyance path,
The web conveyance device, wherein a rotation direction of the guide shaft is the same direction as a conveyance direction of the web.   2. The web conveyance device according to claim 1, wherein the guide shaft is rotated by the driving unit so that an outer peripheral speed of the guide shaft is faster than a conveyance speed of the web.   The guide shaft is rotated by the driving means so that an outer peripheral speed of the guide shaft is 1.2 to 2.0 times a maximum value of a conveyance speed of the web. The web conveying apparatus as described.   The web conveying device according to claim 1, wherein the guide shaft is made of metal.   5. The web conveyance device according to claim 1, wherein the rotation of the guide shaft is started before the web is conveyed to the guide unit.