JP2010058444A - Stencil printing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce flaws such as paper discharge jamming, uneven separation and image blurring by stabilizing the stripping posture of paper sheets. <P>SOLUTION: In a stencil printing device 1 equipped with a printing drum 3 around which a stencil printing original plate 4 is wound, an ink feeding means 8 which supplies ink to the inner circumference surface of the printing drum 3, a press roller 12 which transfers printing ink onto a sheet of paper P while conveying the sheet of paper P inserted in-between the printing drum 3 and the press roller 3, and an air ejection means 16 which jets out air from ejection hole 24 into the space between the tip of the sheet of paper P being transferred between the printing drum 3 and the press roller 12 and the stencil printing original plate 4 wound around the printing drum 3 in order to strip the sheet of paper P, the ejection hole 24 of the air ejection means 16 is arranged to locate in the center of the width direction X of the sheet of paper P while at the same time to be positioned symmetrically across the center in the width direction X and the air jet out from the ejection hole 24 is so designed, against a sheet of paper P, first to hit the center in the width direction X and subsequently to hit symmetrically across from the center to the both ends of the sheet of paper in the width direction X. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for separating a sheet from a printing drum in a stencil printing apparatus that prints by transferring ink onto the sheet by conveying the sheet between a printing drum and a press roller.

  As a paper peeling mechanism in a conventional stencil printing apparatus, there is one in which air is ejected from the tip of a separation claw and the paper is peeled off from a printing drum by the air pressure. The separation claw does not mechanically peel off the paper and therefore does not come into contact with the paper.

  However, depending on the amount, direction, and strength of the air ejected from the separation claw, the paper may tilt in the width direction, and if the paper peeling posture is not stable, paper discharge jam, separation unevenness, image blur (transfer) (Ghost) etc. may be caused.

In order to solve such problems, the center of the separation claw as disclosed in Patent Document 1 below and the injection holes at both sides thereof are dispersed to the both ends in the paper width direction by dispersing air in three directions. There was something that allowed the air pressure to reach. In addition, there are a mechanism for controlling the amount of air ejected from the separation claw, and a mechanism in which a plurality of separation claw are arranged in the width direction of the paper.
Utility Model Registration No. 3123853

  However, in the separation claw having three injection holes as disclosed in the above-mentioned Patent Document 1, air is distributed and injected in three directions from the center and both sides thereof so that the air pressure reaches both ends of the paper. In addition to the fact that the ejection holes are close to the leading edge of the paper, air is ejected from each ejection hole at the same timing, so it hits the paper before it spreads to both ends of the paper, especially for wide paper I couldn't respond enough.

  Further, even when the amount of air ejected from the separation claw is controlled, the air hits only a part of the paper, resulting in insufficient paper peeling.

  Further, in the case where a plurality of separation claws are provided in parallel in the width direction, air is ejected from each ejection hole at the same timing, so the separation start portion at the leading edge of the paper is not determined, and for example, separation starts from a certain portion. In such a case, the sheet may be tilted due to a stronger air resistance than the other part. Also, with such a configuration, the air pressure at the center is strong and the air pressure decreases toward both ends, so that the separation between the center and both ends at the leading edge of the paper is uneven.

  Therefore, the present invention has been made in view of the above situation, and the air ejected from the ejection holes first strikes the center of the sheet in the width direction of the sheet, and then is symmetrical from the center to both ends. It is an object of the present invention to provide a stencil printing apparatus that stabilizes the sheet peeling posture and reduces problems such as paper discharge jam, separation unevenness, and image blur.

Next, means for solving the above problems will be described with reference to the drawings corresponding to the embodiments.
The stencil printing apparatus according to claim 1 of the present invention comprises a printing drum 3 around which a stencil sheet 4 is wound around an ink-permeable outer peripheral surface;
An ink supply means 8 provided inside the printing drum 3 for supplying ink to the inner peripheral surface of the printing drum 3;
A press roller 12 provided outside the printing drum 3 and transferring the ink to the paper P by conveying the paper P between the printing drum 3 and the printing drum 3;
In order to peel the paper P toward the gap between the front end of the paper P conveyed between the printing drum 3 and the press roller 12 and the stencil sheet 4 wound around the outer peripheral surface of the printing drum 3. In the stencil printing machine 1 comprising air jetting means 16 (31) for jetting air from the jetting holes 24 (34),
The ejection holes 24 (34) of the air ejecting means 16 (31) are disposed in the central portion of the paper P in the width direction X, and are disposed symmetrically in the width direction X across the center portion.
The air ejected from the ejection holes 24 (31) first strikes the center of the paper P in the width direction X, and then sequentially strikes the paper in the width direction X symmetrically from the center to both ends. It is said.

  The stencil printing apparatus according to claim 2, wherein the air ejecting means 16 is arranged such that the ejection hole 24 (24 a) located at the center portion in the width direction X of the paper P is closest to the front end of the paper P. The ejection holes 24 (24b, 24c) located farther from the central part are arranged so as to be separated from the front end of the paper P.

  The stencil printing apparatus according to claim 3, wherein the air ejecting means 31 ejects air toward the front end of the paper P through the ejection hole 34 (34 a) located at the center of the paper P in the width direction X. The injection control means 36 for controlling the injection hole 34 (34b) located farther from the central portion to control the air to be injected with a delay.

  According to the stencil printing apparatus of the present invention, the central portion of the paper in the width direction and the air jetted from the plurality of spray holes arranged symmetrically in the width direction across the central portion first hit the central portion of the paper. Next, the paper sheets are peeled symmetrically sequentially toward both ends of the paper, so that the paper starts to peel from the central portion and is peeled symmetrically toward the both ends. As a result, the paper posture is stabilized, and problems such as paper discharge jam, separation unevenness, and image blur can be reduced.

  In addition, the stencil sheet wound around the printing drum is tensioned in the width direction by the jetting holes injecting air from the center in the width direction of the sheet to both ends. As a result, the effect that the wrinkles of the stencil sheet can be extended is obtained.

  Furthermore, since the ejection hole located at the center in the width direction of the paper is closest to the front end of the paper, and the ejection holes farther from the center toward both ends, the air is separated from the front end of the paper, It hits the center and then hits both ends of the paper sequentially.

  In addition, the injection timing is controlled so that the injection hole located at the center of the paper in the width direction injects air toward the leading edge of the paper, and the injection holes that are farther away from the center toward both ends are injected later. As a result, the air first hits the central portion and then hits both ends of the paper sequentially.

Embodiments of the present invention will be specifically described below with reference to the drawings.
FIG. 1 is an overall configuration diagram of a stencil printing apparatus according to the present invention, FIG. 2 is a side view of an essential part of the first embodiment, and FIG. 3 is a plan view as viewed in the direction of arrow A in FIG.

First Embodiment As shown in FIGS. 1 and 2, in the stencil printing apparatus 1, a printing drum 3 is rotatably disposed at a substantially central position in a housing 2. The stencil sheet 4 is wound around the outer periphery of the printing drum 3 that is ink-permeable. The printing drum 3 is rotationally driven in the direction of the arrow in FIG. 2 around the rotation shaft 6 by a driving means 5 such as a motor. A clamp means 7 for holding the tip of the stencil sheet 4 is provided on the outer peripheral surface of the printing drum 3.

  Inside the printing drum 3, ink supply means 8 that supplies ink to the inner peripheral surface of the printing drum 3 is provided. The ink supply unit 8 includes a squeegee roller 9 that rotates while being in contact with the inner peripheral surface of the printing drum 3, a doctor roller 10 provided in the vicinity of the squeegee roller 9, and the squeegee roller 9 and the doctor roller 10. And an ink supply pipe 11 for supplying ink.

  A press roller 12 is provided outside the printing drum 3 in the vicinity of the printing drum 3. The press roller 12 is provided so as to be movable up and down, and contacts and separates from the printing drum 3. The press roller 12 rotates in the direction opposite to the rotation of the printing drum 3. Further, in the vicinity of the press roller 12, a pair of transport rollers 13 and 13 for transporting between the printing drum 3 and the press roller 12 are provided.

  As shown in FIG. 1, a paper feed tray 14 is provided on one side surface of the housing 2. Sheets P are stacked on the sheet feed tray 14. A paper discharge tray 15 is provided on the other side surface of the housing 2.

  Further, in the housing 2, air jetting means 16 to be described later for peeling the paper P from the outer peripheral surface (the stencil sheet 4) of the printing drum 3 on the downstream side of the conveyance of the printing drum 3 and the press roller 12, printing A suction conveyance means 17 is provided for conveying the paper P peeled from the outer peripheral surface of the drum 3 while sucking it.

  In the stencil printing apparatus 1, a sheet feed roller (not shown) supplies the paper P placed on the sheet feed tray 14 to the transport rollers 13 and 13 one by one. The ink is transferred to the paper P by being conveyed in between and printed. Specifically, the paper P is sandwiched between the printing drum 3 and the press roller 12, and the ink inside the printing drum 3 is pushed out by the squeegee roller 9 and passes through the ink-permeable outer peripheral surface of the printing drum 3. An image is printed on the paper P. Then, the paper P to which the ink has been transferred is peeled off from the outer peripheral surface of the printing drum 3 by the air ejecting means 16 and discharged to the paper discharge tray 15 through the suction conveyance means 17.

From here, the air injection means which is the principal part of this invention is demonstrated.
The air ejecting means 16 described above has an air gap between the front end of the paper P (the end on the downstream side of the conveyance) and the stencil paper 4 in order to peel the paper P from the stencil paper 4 wound around the outer peripheral surface of the printing drum 3. Is to inject.

  As shown in FIGS. 1 and 2, the air ejecting unit 16 is provided on the downstream side of the conveyance of the printing drum 3 and the press roller 12 in the housing 2. The air ejecting means 16 includes a paper separating unit 18, a compression pump 19, and an air pipe 20, and the paper separating unit 18 is connected to the compression pump 19 through the air pipe 20.

  As shown in FIGS. 2 and 3, the sheet separation unit 18 rotates a plurality of (three) separation claws 21, an operation shaft 22 that rotatably supports these separation claws 21, and the operation shaft 22. Drive means 23.

  The operation shaft 22 is disposed in the vicinity of the printing drum 3 and is disposed in parallel with the rotation shaft 6 of the printing drum 3. As shown in FIG. 3, the main separation claw 21 </ b> A is disposed at a position corresponding to the width direction of the printing drum 3 on the operation shaft 22, that is, the center portion in the width direction X of the paper P. The main separation claw 21A is provided with a single injection hole 24 (24a) for injecting air at its tip, and is injected symmetrically across the injection hole 24a at the center on both sides in the width direction X of the injection hole 24a. Holes 24, 24 (24b, 24b) are provided. On both sides of the main separation claw 21A in the width direction X, the sub-separation claws 21B and 21B are arranged symmetrically with the main separation claw 21A interposed therebetween with a predetermined distance (about 2 to 6 cm) according to the plate size of the paper P. ing. Each sub-separation claw 21B is provided with one injection hole 24 (24c). As for the injection hole 24, the injection holes 24b and 24b and the injection holes 24c and 24c are symmetrically arranged in the width direction X across the both ends of the paper P with the central injection hole 24a interposed therebetween. The diameter of each injection hole 24 is formed such that the central injection hole 24a is about φ1.2 mm, the injection hole 24b is about φ1.0 mm, and the injection hole 24c is about φ0.6 to 1.2 mm.

  As shown in FIG. 3, since the main separation claw 21A disposed at the central portion in the width direction X of the paper P is formed longer than the sub separation claw, the injection hole 24a of the main separation claw 21A is the most paper. It is arranged close to the tip. The next closest holes are the injection holes 24b and 24b, and the injection holes 24c and 24c of the sub-separation claw 21B are arranged farthest from the leading edge of the sheet. That is, the ejection holes 24 are arranged so as to be separated from the front end of the paper P as they are separated from the central portion in the width direction X of the paper P toward both ends.

  The drive means 23 rotates the operating shaft 22 to swing each separation claw 21 (21A, 21B) between a position close to the printing drum and a position separated from the printing drum. When attaching, the separation claws 21A and 21B are held at positions separated from the printing drum to prevent interference with the stencil sheet 4, and at the time of printing on the paper P, the paper P is peeled off by repeating the approach and separation to the printing drum 3. Interference prevention for the clamping means 7 is performed alternately. In addition, as the drive means 23, a solenoid, a motor, etc. can be used.

  As shown in FIG. 3, the stencil printing apparatus 1 includes a control unit 25. The control means 25 controls the rotational drive during the attachment / detachment operation of the stencil sheet 4 of the printing drum 3 or during printing, the overall control of each part interlocked therewith, and the drive of the compression pump 19 as a part of the air injection means 16. To control.

  According to the embodiment described above, the injection hole 24a at the center in the width direction X of the paper P, the injection holes 24b and 24b, and the injection holes 24c and 24c arranged symmetrically in the width direction X across the center. The air ejected from the first hits the central portion of the paper P, and then sequentially hits both ends of the paper P in a symmetrical manner so that the paper P starts to peel from the central portion and peels symmetrically to both ends. Become. Thereby, the paper posture at the time of peeling is stabilized. In addition, the stencil sheet 4 wound around the printing drum 3 is tensed in the width direction X by jetting air from the center to the both ends of the sheet P in the width direction X, and the wrinkles of the stencil sheet 4 may be extended. it can.

  Further, the ejection hole 24a located at the center of the sheet P in the width direction X is closest to the front end of the sheet P, and the ejection holes 24c and 24c that are separated from the center toward both ends are separated from the front end of the sheet P. As a result, the air first hits the central portion and then sequentially hits both ends of the paper.

FIG. 4 is a side view of an essential part of the second embodiment, FIG. 5 is a plan view taken along arrow B in FIG. 4, and FIGS. 6A and 6B are timing charts of air injection.
Note that in the second embodiment described below, the same reference numerals are given to the same or similar portions as those in the above-described embodiment, and the description thereof is omitted.

Second Embodiment As shown in FIGS. 1 and 4, the air injection means 31 is provided on the downstream side of the conveyance of the printing drum 3 and the press roller 12 in the housing 2 as in the above-described embodiment. . The air ejecting means 31 includes a paper separation unit 32, a compression pump 19, and an air pipe 20, and the paper separation unit 32 is connected to the compression pump 19 through the air pipe 20.

  As shown in FIGS. 4 and 5, the paper separation unit 32 rotates a plurality of (three) separation claws 33, an operation shaft 22 that rotatably supports these separation claws 33, and the operation shaft 22. Drive means 23.

  As shown in FIG. 5, the main separation claw 33 </ b> A is disposed at a position corresponding to the width direction of the printing drum 3 on the operation shaft 22, that is, the center portion in the width direction X of the paper P. One injection hole 34 (34a) for injecting air is provided at the tip of the main separation claw 33A. On both sides of the main separation claw 33A in the width direction X, the sub-separation claws 34B and 34B are arranged symmetrically with the main separation claw 33A interposed therebetween with a predetermined distance (about 2 to 6 cm) according to the plate size of the paper. Yes. Each sub-separation claw 33B is provided with one injection hole 34 (34b). The injection holes 34b are arranged symmetrically with respect to the injection hole 34a at the center. The diameter of each injection hole 34 is formed such that the central injection hole 34a is about φ1.2 mm and the injection hole 34b is about φ0.6 to 1.2 mm. The main separation claw 33A and the sub separation claws 33B and 33B are formed to have substantially the same length. Accordingly, each of the ejection holes 34a, 34b, 34b is arranged at an equal distance from the front end of the paper P.

  As shown in FIGS. 4 and 5, an electromagnetic valve 35 is provided immediately before each of the separation claws 33 </ b> A, 33 </ b> B, 33 </ b> B in the air pipe 20 connecting the paper separation unit 32 and the compression pump 19. The electromagnetic valve 35 is normally closed and is electrically connected to the injection control means 36.

  A part of the function of the control means 25 is the injection control means 36. The ejection control means 36 controls the opening / closing timing of each electromagnetic valve 35 in synchronization with the rotation of the printing drum 3 when air is supplied from the compression pump 19.

  As shown in FIG. 6, in this embodiment, there are two patterns for opening / closing control (air injection control) of each electromagnetic valve 35 by the injection control means 36. For example, as shown in FIG. 6A, first, when the leading end of the paper P approaches the main separation claw 33A by the rotation of the printing drum 3, the electromagnetic valve 35 of the main separation claw 33A is opened and the injection hole is opened. Air is sprayed from 34a to the center of the leading edge of the paper P. Next, the electromagnetic valves 35 and 35 of the two sub-separation claws 33B and 33B are simultaneously opened with a predetermined time delay, and air is injected from the respective injection holes 34b and 34b to both ends of the leading end of the paper P in the width direction X. To control. At this time, the delay time is about 15 msec, and the electromagnetic valves 35 are opened for a predetermined time, respectively, and are sequentially closed at the end of the sheet peeling.

  In the other pattern, as shown in FIG. 6B, when the leading end of the paper P approaches the main separation claw 33A by the rotation of the printing drum 3, the electromagnetic valve 35 of the main separation claw 33A is opened. Air is ejected from the ejection hole 34a to the center of the leading edge of the paper P, and after a predetermined time, the electromagnetic valve 35 is closed. Next, at the same time that the electromagnetic valve 35 is closed, the electromagnetic valves 35 and 35 of the two sub-separating claws 33B and 33B are simultaneously opened, and both ends in the width direction X of the leading end of the paper P from the respective injection holes 34b and 34b. Control is performed so that air is injected into the section. These electromagnetic valves 35 and 35 are also closed after injecting air from the injection holes 34b and 34b for a predetermined time.

  According to the above-described embodiment, as in the first embodiment, the injection hole 34a at the center in the width direction X of the paper P and the injection holes arranged symmetrically in the width direction X across the center. The air jetted from 34b, 34b first hits the central portion of the paper P, and then strikes symmetrically sequentially toward both ends of the paper P, so that the paper P begins to peel from the central portion and symmetrically toward both ends. It will come off. Thereby, the paper posture at the time of peeling is stabilized. In addition, the stencil sheet 4 wound around the printing drum 3 is tensed in the width direction X by jetting air from the central part of the sheet P in the width direction X to both ends, and the wrinkles of the stencil sheet 4 can be extended.

  Further, the injection hole 34a located at the center portion in the width direction X of the paper P injects air toward the front end of the paper P, and the injection holes 34b and 34b on both end sides inject air with a predetermined time delay. By controlling the ejection timing, the air first hits the center of the paper P and then sequentially hits both ends of the paper P.

  In addition, it is also possible to combine the air injection means 16 and 31 provided in the first and second embodiments described above. That is, as in the first embodiment, the separation claw in the center portion in the width direction X of the paper P is disposed closest to the front end of the paper P, and the separation claw farthest from the central portion is the front end of the paper P. The injection timing of the air from each separation claw is controlled by the injection control means as in the second embodiment. According to this configuration, the air can be sequentially and reliably applied from the central portion of the paper P to both ends.

1 is an overall configuration diagram of a stencil printing apparatus according to the present invention. It is a principal part side view of 1st Embodiment. It is a top view of A arrow in FIG. It is a principal part side view of 2nd Embodiment. It is a top view of A arrow in FIG. (A), (b) It is a timing chart of air injection.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Stencil printing device 3 ... Printing drum 4 ... Stencil paper 8 ... Ink supply means 12 ... Press roller 16, 31 ... Air injection means 24, 34 ... Injection hole 36 ... Injection control means P ... Paper X ... Paper width direction

Claims (3)

A printing drum in which a stencil sheet is wound around an ink-permeable outer peripheral surface;
An ink supply means provided inside the printing drum, for supplying ink to the inner peripheral surface of the printing drum;
A press roller that is provided outside the printing drum and transfers the ink to the paper by conveying the paper with the printing drum sandwiched between the press drum;
Air is ejected from the ejection holes to peel the paper toward the gap between the leading edge of the paper conveyed between the printing drum and the press roller and the stencil paper wound around the outer peripheral surface of the printing drum. An stencil printing apparatus comprising:
The ejection holes of the air ejection means are disposed at the center in the width direction of the paper, and are disposed symmetrically in the width direction across the center.
The stencil printing apparatus according to claim 1, wherein the air jetted from the jetting holes first strikes the central portion in the width direction with respect to the paper, and then sequentially strikes symmetrically in the width direction from the central portion to both ends.   In the air ejecting means, the ejection hole located at the central portion in the width direction of the paper is disposed closest to the front end of the paper, and the ejection holes located farther from the central portion are separated from the front end of the paper. The stencil printing apparatus according to claim 1, wherein the stencil printing apparatus is arranged as follows.   The air jetting unit jets air toward the leading end of the paper, and the jet holes located at the center of the paper in the width direction, and jets air later as the jet hole is located farther from the center. The stencil printing apparatus according to claim 1, further comprising: an ejection control unit that controls the stencil as described above.

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