JP4824314B2 - Stencil printing drum and stencil printing device - Google Patents

Description

  The present invention relates to a stencil printing drum and a stencil printing apparatus having the stencil printing drum, and more particularly to a stencil printing drum and a stencil printing apparatus that prevent ink leakage from both ends of the stencil printing drum.

A general stencil printing drum (hereinafter sometimes simply referred to as “printing drum”) is provided with a plate cylinder having an ink-permeable region and an inner surface of the plate cylinder in contact with the plate cylinder. An ink roller that supplies ink, and a doctor roller that forms an ink reservoir between the ink roller and forms an almost constant amount of ink film layer on the outer peripheral surface of the ink roller.
In addition, a porous support made of a Japanese paper fiber or synthetic fiber or a mixture of Japanese paper and synthetic fiber is bonded to the printing drum and a thermoplastic resin film (thickness of about 1 to 3 μm is generally used). Using a master (plate) with a laminated structure, the thermoplastic resin film surface of the master is heated and perforated by a plate making means such as a thermal head based on image information read from a document or image information transmitted from a personal computer or the like. After making the plate, it is wound around the outer peripheral surface of the plate cylinder, and ink is supplied to the inner peripheral surface of the plate cylinder from an ink supply means including an ink roller and a doctor roller provided inside the plate cylinder. By pressing the printing paper against the pre-printed master on the plate cylinder with pressing means such as an impression cylinder, the ink that has oozed out from the opening portion of the plate cylinder and the master perforation portion is printed. Stencil printing apparatus of a thermal digital printing is performed by transferring to the paper it is also well known (e.g., see Patent Document 1).

  In an ordinary stencil printing apparatus, an emulsion ink (hereinafter simply referred to as “ink”) made of a mixture of water and oil as a main component is used. This ink is uniformly agitated and kneaded by the ink roller and doctor roller inside the plate cylinder in the printing drum, and the plate cylinder passes through a large number of fine holes formed in the plate cylinder and a mesh screen wound as appropriate. It is a mechanism for printing by supplying to the outer periphery, and further transferring and transferring onto the printing paper through an opening (ink passage) formed by perforating and pre-rolled around the outer surface of the plate cylinder. .

  Here, when the perforation rate of the master is large (the image area rate is large), the ink is consumed quickly, and new ink is always supplied to the ink reservoir formed between the ink roller and the doctor roller. become. However, when printing an image with a very low master perforation rate (small image area rate) is repeated, the ink consumption is slow, so the ink on the ink roller and doctor roller is not easily consumed. It will be stirred and kneaded for a period of time. In such a case, the water in the ink evaporates and only the oil remains. Ink with only oil content loses viscosity and becomes a low-viscosity liquid. Normal ink maintains a certain level of viscosity, so it is held on the ink roller and doctor roller, but the liquefied ink flows down from the ink roller and falls onto the inner peripheral surface of the plate cylinder. When left unattended (long-term stop state of the stencil printing apparatus and printing drum), the ink roller tries to flow out of the plate cylinder from both ends (both sides) of the ink roller.

  On the other hand, as a technique for collecting ink protruding outside the ink roller to the ink roller side, for example, an ink weir described in JP-A-7-257004 and a scraping piece described in Utility Model Registration No. 2572701 are known. Yes.

Japanese Patent Laid-Open No. 2003-312115 JP 7-257004 A Utility Model Registration No. 2572701

  However, in the technique described in Japanese Patent Application Laid-Open No. 7-257004 and Utility Model Registration No. 2572701, the ink liquefied by leaving the stencil printing apparatus for a long time is near the lowest position on the inner peripheral surface of the plate cylinder by the action of gravity. It is impossible to prevent a malfunction that falls into the ink roller and flows out of the plate cylinder from both sides of the ink roller. That is, in both of the above techniques, it works effectively only when the ink roller is rotating, and when the apparatus / machine is stopped (specifically, the plate cylinder, the ink roller, etc. are in a stopped state). In this case, since the ink weir and the scraping piece are not provided in the portion including the lowest part of the inner peripheral surface of the plate cylinder, the effect of preventing the ink outflow as described above cannot be exhibited. is there. Therefore, in any of the above technologies, the ink flows out to both sides of the plate cylinder and the printing drum when the printing drum is left standing for a long time. Dirty or dirty printing paper. When such a malfunction occurs at the user site, it becomes a claim and the reliability of the machine is greatly impaired.

  In other words, in conventional printing drums, the inner circumference of the plate cylinder is used to prevent the phenomenon that ink liquefied by leaving the stencil printing apparatus for a long time flows out from both sides of the ink roller to the outside of the plate cylinder. Since no member that prevents ink outflow was provided on both sides of the ink roller including the lowest part of the surface, the ink that flowed on both sides of the ink roller had flowed out of the printing drum.

  Accordingly, the present invention has been made in view of the above-described circumstances, and liquefied ink that has been liquefied due to long-term leaving of a stencil printing drum / stencil printing apparatus flows out of the plate cylinder from both sides of the ink roller. It is a main object of the present invention to provide a stencil drum and a stencil printing apparatus that can prevent such a problem. Another object of the present invention is to provide a stencil printing drum and a stencil printing apparatus that exhibit the effects and advantages described below.

In order to solve the above-mentioned problems and achieve the above object, the present invention employs the following invention specific matters (hereinafter referred to as “configuration”) in the invention of each claim. It is.
The invention according to claim 1 is a plate cylinder provided with an ink-permeable region, and is rotatable around an axis provided inside the plate cylinder and parallel to the central axis of the plate cylinder. An ink supply member that supplies W / O type emulsion ink ink in contact with the peripheral surface and an ink reservoir formed in parallel with the ink supply member with a small gap therebetween. And a stencil printing drum comprising an ink metering member that forms a substantially constant ink layer on the outer peripheral surface of the ink supply member, provided inside the plate cylinder outside both ends of the ink supply member, The ink dam member has a pair of ink dam members that contact the inner peripheral surface in the vicinity including the lowest part of the inner peripheral surface to block ink, and each of the ink dam members includes a pair of ink dam members including the lowest part of the inner peripheral surface. A subarc-shaped peripheral surface in contact with the inner peripheral surface; A front end portion of the ink dam member on the upstream side in the rotation direction of the plate cylinder includes an inclined portion inclined toward the outside of each end portion of the plate cylinder, and an elastic deformation portion that has elasticity and can be elastically deformed. The upper part of each ink dam member is formed in a step shape in the vertical direction when viewed from the axial direction of the ink supply member, and the lowest part of the inner peripheral surface with which the lower part of each ink dam member contacts from the height of to the lowest portion of said stepped shape of said each ink dam member being set in consideration of the maximum ink storage capacity before the liquefaction of reservoir above the ink, each ink dam member , when viewed from the axial direction of the ink supply member, the top of the extension line of said stepped shape of said each ink dam member is formed at a height that overlaps the axis of the ink supply member, and the Above contact with the inner surface The distal end portion and the rear end portion of the downstream side in the rotational direction of the plate cylinder Nki weir member extends to the intersection of the the top of the extension and the inner peripheral surface intersects, yet, the elastic deformation portion It is comprised so that it may contact the said internal peripheral surface by the elastic deformation by.

According to a second aspect of the invention, the stencil printing drum according to claim 1, characterized in that it has a biasing means for biasing the respective ink dam member in a direction in contact with the inner peripheral surface.

According to a third aspect of the invention, has a stencil printing drum of the mounting according to claim 1 or 2 SL, printing by supplying ink from the inner peripheral surface side in the stencil master wound around on the pore size printing drum The stencil printing apparatus is characterized in that it performs.

According to the present invention, a conventional stencil drum and stencil printing apparatus can be provided by solving the above-mentioned conventional problems. The effects for each claim are as follows.
According to the first aspect of the present invention, each ink dam member is configured to come into contact with the inner peripheral surface of the plate cylinder by elastic deformation by the elastic deformation portion of each ink dam member. The adhesion between the inferior arc-shaped peripheral surface of the plate and the inner peripheral surface of the plate cylinder is increased, and it is possible to cope with a slight change in unevenness on the inner peripheral surface of the plate cylinder. Including stencil drums for a long period of time or by repeating continuous printing with extremely low image area ratio and low ink consumption, the water content of the W / O emulsion ink system is evaporated, leaving almost only oil. When the viscosity is lost, when the ink flows from the ink reservoir onto the inner peripheral surface in the vicinity including the lowest part of the inner peripheral surface of the plate cylinder and tries to flow to both ends (both sides) of the ink supply member in the axial direction. Ink supply In addition to being able to prevent the flow from both ends (both sides) of the material to the outside of the plate cylinder and the stencil printing drum with an inexpensive structure, the front and rear ends of each ink weir member and the axis of the ink supply member The height from the lowest part of the inner peripheral surface of the plate cylinder where each ink weir member outside the both ends of the direction and the lower part of each ink weir member contacts to the lowest part of the step shape on the upper part of each ink weir member The liquefied ink corresponding to the maximum ink storage capacity can be stored in the space surrounded by the top and the leading end of each ink dam member on the upstream side in the rotation direction of the plate cylinder is connected to each end of the plate cylinder. By inclining toward the outside of the ink jet section, even if the ink leaks to the outside of the ink weir member, the ink can be collected again on the ink supply member side, so that the plate cylinder and the stencil printing drum Outside It is possible to eliminate it reliably the ink from leaking out, or worse soil the interior hence the stencil printing machine, the occurrence of user complaints or got dirty printing paper can be prevented.

According to the second aspect of the present invention, by having a biasing means for biasing in a direction in which contact with each ink dam member on the inner peripheral surface of the plate cylinder, in contact with the inner peripheral surface of each ink dam member plate cylinder As a result, the adhesion between the inferior arc-shaped peripheral surface and the inner peripheral surface of the plate cylinder is further increased, thereby further preventing ink from flowing out from both ends (both sides) of the ink supply member to the outside of the plate cylinder and the stencil printing drum. At the same time, the inferior arc-shaped peripheral surface of each ink dam member and the inner peripheral surface of the plate cylinder are always in contact with each other by the urging force of the urging means. Although it is a little worn, even in that case, there is an effect of preventing ink outflow that is the same as the initial stage.

According to the third aspect of the invention, the stencil printing apparatus having the stencil printing drum having the above-described effects prevents ink from leaking out of the stencil printing drum and the stencil printing drum. or got dirty, Ru it is possible to prevent the occurrence of a user claims or got dirty the printing paper in advance.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention including the best mode and examples for carrying out the invention will be described with reference to the drawings. Constituent elements such as members and components having the same functions and shapes in the embodiment and reference examples are denoted by the same reference numerals and will not be described after being described once. In order to simplify the drawings and the description, even components that are to be represented in the drawings may be omitted as appropriate without being specifically described in the drawings. When a constituent element such as a published patent publication is cited and explained as it is, the reference numeral is attached with parentheses to distinguish it from that of the embodiment.

First, the overall configuration and operation of a thermal digital stencil printing apparatus to which the present invention is applied will be described with reference to FIG.
In FIG. 6, reference numeral 65 denotes an apparatus main body frame that forms the framework of the stencil printing apparatus. The part indicated by reference numeral 80 on the upper part of the apparatus main body frame 65 constitutes an image reading unit, the part indicated by reference numeral 90 below the plate making and feeding part, and the part indicated by reference numeral 50 on the left side thereof constitutes a stencil printing drum. The printing drum on which the printing cylinder 1 and the like to be arranged are arranged, the portion indicated by the reference numeral 70 on the left of the printing drum, the portion indicated by the reference numeral 110 below the plate making plate feeding section 90 is the paper feeding section, and the reference numeral 120 below the printing cylinder 1 A portion indicated by is a printing pressure portion, and a portion indicated by reference numeral 130 on the lower left side of the apparatus main body frame 65 is a paper discharge portion.

Next, the operation of the heat-sensitive digital stencil printing apparatus will be described below, including its detailed configuration.
First, a document 60 having an image to be printed is placed on a document placing table (not shown) arranged at the top of the image reading unit 80, and a plate making start key (not shown) on an operation panel (not shown) is placed. Push. Along with the pressing of the plate making start key, a plate removing process is first executed. That is, in this state, the used master 2 b used in the previous printing remains attached to the outer peripheral surface of the plate cylinder 1 of the printing drum 50.
The plate cylinder 1 rotates in the counterclockwise direction opposite to the rotation direction A indicated by an arrow in FIG. 6, and the rear end portion of the used master 2b on the outer peripheral surface of the plate cylinder 1 is the pair of plate release rollers 71a and 71b in the plate release portion 70. As the roller pair 71a, 71b is rotated, the rear end portion of the used master 2b is scooped up and peeled off by one discharge plate peeling roller 71a while rotating, and the used master 2b thus peeled off is the discharged plate peeling roller pair 71a. , 71b and a plate discharge box 74 while being conveyed in the direction of arrow Y1 by a pair of plate discharge conveyor belts 72a, 72b stretched between a pair of plate discharge rollers 73a, 73b and a pair of plate release peeling rollers 71a, 71b. The used master 2b is peeled off from the outer peripheral surface of the plate cylinder 1, and the plate discharging process is completed. At this time, the plate cylinder 1 continues to rotate counterclockwise. The used master 2 b that has been peeled and discharged is then compressed inside the plate discharging box 74 by the compression plate 75.

  In parallel with the plate removal process, the image reading unit 80 reads an image of a document. That is, the document 60 placed on a document placement table (not shown) is conveyed in the directions of arrows Y2 to Y3 by the rotation of the separation roller 81, the front document conveyance roller pair 82a and 82b, and the rear document conveyance roller pair 83a and 83b. It is used for exposure reading. At this time, when there are a large number of documents 60, only the lowermost document is conveyed by the action of the separating blade 84. When reading the image of the original 60, the reflected light from the surface of the original 60 illuminated by the fluorescent lamp 86 while being conveyed on the contact glass 85 is reflected by a mirror 87 and passed through a lens 88 from a CCD (charge coupled device) or the like. This is performed by entering the image sensor 89. The document 60 from which the image has been read is discharged onto the document tray 80A. The electrical signal photoelectrically converted by the image sensor 89 is input to an analog / digital (A / D) converter (not shown) in the apparatus main body frame 65 and converted into a digital image signal.

  On the other hand, in parallel with this image reading operation, plate making and plate feeding processes are performed based on the digital signalized image information. That is, the master 2 set at a predetermined portion of the plate-making plate feeding unit 90 is pulled out from the roll state wound in a roll shape, and pressed against the thermal head 91 as plate-making means for making the master 2 via the master 2. By the rotation of the platen roller 92 and the feed roller pair 93a and 93b, the platen roller 92 is intermittently conveyed to the downstream side of the conveyance path. A large number of minute heating elements arranged in a line in the main scanning direction of the thermal head 91 with respect to the master 2 transported in this way correspond to the digital image signal sent from the A / D converter. The portions of the thermoplastic resin film of the master 2 that selectively generate heat and are in contact with the generated heating elements are heated, melted, and perforated. Thus, the image information is written as a drilling pattern by position-selective melt drilling of the master 2 according to the image information.

The leading end of the plate-making master 2a on which image information has been written is fed toward the outer peripheral side of the plate cylinder 1 by a pair of plate feeding rollers 94a and 94b, and the traveling direction is changed downward by a guide member (not shown). The plate cylinder 1 in the plate feeding position state shown in FIG. 2 hangs down toward the clamper 3 indicated by the expanded two-dot chain line. At this time, the used master 2b has already been removed from the plate cylinder 1 by the discharging process.
When the leading end of the master 2a is clamped by the clamper 3 at a constant timing, the master 1a gradually winds the master 2a around the outer peripheral surface while rotating in the rotation direction A. The rear end portion of the master-making master 2a is cut to a certain length by the cutter 95 after the completion of the plate-making.

  When one plate-made master 2a is wound around the outer peripheral surface of the plate cylinder 1, the plate-making and plate-feeding steps are finished, and the printing step is started. First, the uppermost one of the printing papers P stacked on the paper feed tray 66 is sent in the direction of arrow Y4 toward the registration roller pair 113a, 113b by the paper feed roller 111 and the separation roller pair 112a, 112b. Further, it is sent to the printing pressure unit 120 at a predetermined timing synchronized with the rotation of the plate cylinder 1 by the registration roller pair 113a, 113b. When the fed printing paper P comes between the plate cylinder 1 and the press roller 9 as the pressing means, the press roller 9 indicated by a two-dot chain line in FIG. By being displaced upward as indicated by a solid line in the figure, the plate-making master 2 a wound around the outer peripheral surface of the plate cylinder 1 is pressed. In this way, ink oozes out from the opening portion of the plate cylinder 1 and the piercing portion (both not shown) of the plate-making master 2a, and the oozing ink is transferred to the surface of the printing paper P to form a printed image. The

  At this time, on the inner peripheral side of the plate cylinder 1, an ink roller as an ink supply member that supplies ink in contact with the inner peripheral surface of the plate cylinder 1 from a plurality of ink supply holes 8 a formed in the ink supply pipe 8. Ink is dripped and supplied to an ink reservoir 7 formed between 5 and the doctor roller 6, and rotates in the same direction as the rotation direction A of the plate cylinder 1 and in synchronization with the rotation speed of the plate cylinder 1. However, ink is supplied to the inner peripheral side of the plate cylinder 1 by the ink roller 5 that is in rolling contact with the inner peripheral surface. As the ink, for example, a W / O type emulsion ink type is preferably used, but it is of course not limited thereto.

  The printing paper P on which the printing image is formed in the printing pressure unit 120 is peeled off from the plate cylinder 1 by the paper discharge claw 114 in the paper discharge unit 130 and sucked by the suction fan 118, while the suction paper discharge inlet roller 115 and The conveyance belt 117, which is stretched around the suction discharge outlet roller 116 and formed with a plurality of air suction holes, is conveyed counterclockwise as indicated by arrow Y5 and discharged. The sheets are sequentially discharged and stacked on the paper board 67. In this way, so-called trial printing (also called plate printing) is completed.

  Next, when the number of prints is set with a numeric keypad (not shown) arranged on the operation panel (not shown) and a print start key (not shown) arranged on the operation panel is pressed, the same as the above-described test printing. In this step, the paper feeding, printing, and paper discharging steps are repeated for the set number of printed sheets, and all the stencil printing steps are completed.

( Reference Example 1 )
1 to 3 show Reference Example 1 according to the stencil printing apparatus of the present invention.
In FIG. 2, the thickness of the plate cylinder 1 and the size of the opening 1c, the length L1 of the plate cylinder 1 of the ink roller 5 in the axial direction Y (also the paper width direction Y and the master width direction Y), and the axis 5a The length, the maximum pressing range length L2 in the axial direction Y of the plate cylinder 1 in the press roller 9, the length L1a in the axial direction Y of the plate cylinder 1 in the ink-permeable region 1a, the thicknesses of the side plates 11 and the side blades 12, etc. In addition, the drawing is enlarged and exaggerated, and the dimensional ratios of the respective components are illustrated neglecting each other.
For convenience of explanation, the configuration around the printing drum 10 will be described in more detail.
The plate cylinder 1 is also called a support cylindrical body, and in the same manner as in the past, for example, an ink-permeable region 1a (or an aperture region) is formed by opening a large number of apertures 1c by an etching method (chemical corrosion method) or the like. Produced by bending a thin stainless steel plate into a cylindrical shape. The plate cylinder 1 has a predetermined elastic restoring property. Each end plate (not shown) is attached and fixed to each end edge of the plate cylinder 1. Each edge portion of the plate cylinder 1 is wound around the outer periphery of each of the end plates, and is attached and fixed by fastening means such as screws. The plate cylinder 1 is rotatable around a support shaft 8 that also serves as the ink supply pipe 8 shown in FIG. 6 through a rolling bearing (not shown) disposed at the center of the both end plates together with the above-described end plates. It is supported by. The ink impervious region 1 b (non-perforated region) is provided not only in the arrangement portion of the clamper 3 but also in each edge portion of the plate cylinder 1.
On a part of the outer peripheral surface of the plate cylinder 1, as simply shown in FIG. 6, a member called a clamper base portion that holds the above-described clamper 3 via a shaft includes an ink impermeable region (not shown). )) Along the outer peripheral one bus bar. The plate cylinder 1 is rotationally driven in the rotational direction A (clockwise direction) and counterclockwise by a drive motor (not shown) such as a DC motor.

As shown in FIGS. 1 and 6, the ink supply device 4 is provided inside the plate cylinder 1, and the ink as an ink supply member that supplies ink in contact with the inner peripheral surface 1 d of the plate cylinder 1. The roller 5 and the ink roller 5 are arranged in parallel with a minute gap, and an ink reservoir 7 having a wedge-shaped cross section is formed between the roller 5 and the ink roller 5, and a substantially constant film-like shape is formed on the outer peripheral surface of the ink roller 5. It is mainly composed of a doctor roller 6 as an ink metering member for forming an ink layer and an ink supply pipe 8 for supplying ink to the ink reservoir 7.
The ink roller 5 is formed integrally with the shaft 5a from a metal such as aluminum or stainless steel or rubber, and the gear roller including the gear 5b fixed to one end of the ink roller shaft 5a is used to form the plate cylinder 1. It rotates in the rotation direction A together with the plate cylinder 1 around an axis parallel to the central axis. The ink roller 5 is arranged so that the plate cylinder 1 is elastically deformed inward when in contact with the inner peripheral surface 1d when the press roller 9 is pressed.
The doctor roller 6 is made of metal such as iron or stainless steel, and rotates counterclockwise opposite to the rotation direction A by a gear train (not shown). The ink roller 5 and the doctor roller 6 are rotatably supported by a pair of side plates 11 suspended and fixed to the ink supply pipe 8 via a bearing such as a rolling bearing. In FIG. 2, the doctor roller 6 is virtually indicated by a two-dot chain line. The side plate 11 is formed of, for example, a metal plate having ink corrosion resistance such as stainless steel, or a sheet metal subjected to appropriate surface treatment.

The reference example 1 shown in FIGS. 1 to 3 is different from the stencil printing apparatus having the printing drum 50 shown in FIG. 6 in that it has a printing drum 10 instead of the printing drum 50. The point is the same as that of the stencil printing apparatus shown in FIG.
Compared with the printing drum 50 shown in FIG. 6, the printing drum 10 is provided inside the plate cylinder 1 outside the both ends and both sides of the ink roller 5, as shown in FIGS. The main difference is that it has a pair of side blades 12 as ink dam members that contact the peripheral inner peripheral surface 1d including the lowest part of the inner peripheral surface 1d of the cylinder 1 and block the ink. This is the same as the printing drum 50 shown in FIG. In other words, the side blade 12 is configured such that the ink impervious region (non-perforated region) 1b between each end plate (not shown) of the plate cylinder 1 and each end portion of the ink roller 5 facing the end plate. In this case, the ink is disposed so as to dam the ink by contacting the peripheral inner peripheral surface 1d including the lowest part of the inner peripheral surface 1d of the plate cylinder 1.
1 to 3, only one side blade 12 disposed corresponding to one end of the ink roller 5 is shown. However, the other side blade 12 is connected to the other end of the ink roller 5. Of course, it is arranged correspondingly.

  The side blade 12 is inferior in the shape of a generally crescent or fan shape in which the arcuate circumferential surface 12a at the lower part thereof substantially coincides with the shape of the inner circumferential surface 1d of the plate cylinder 1 so that the side blade 12 always contacts the inner circumferential surface 1d of the plate cylinder 1. It is provided with a circumferential surface in the form of an arc (meaning an arc smaller than half of the circumference) and is integrally formed. The side blades 12 are attached and fixed to the back wall of the side plate 11 with screws 14. The side blade 12 is not only an ink impermeable material because of its function, but the arc peripheral surface 12a is always in contact with the inner peripheral surface 1d of the plate cylinder 1, so that the side blade 12 is less worn and resistant to wear. For example, polyacetal resin (POM) is integrally formed as a material that has ink corrosion resistance (oil resistance) and does not increase the load on the drive motor or the like. Needless to say, the material of the side blade 12 is not limited to the resin as long as it satisfies the above functions.

  The arrangement positions of the side blades 12 in the axial direction Y (paper width direction Y) of the plate cylinder 1 are arranged as described above with reference to FIG. Accordingly, the circular arc peripheral surface 12a formed in the lower part of the side blade 12 is compared with the inner peripheral surface state of the ink-permeable region 1a, and the ink-impermeable region 1b of the plate cylinder 1 where the opening 1c is not formed. Therefore, its own wear and the load on the drive motor and the like are not so serious problems (the side blades 12A and 12B, which will be described later) The same).

  The arrangement position of the side drum 12 in the axial direction of the plate cylinder 1 is centered on the center of the ink roller 5, the attachment position of each end plate (not shown) of the plate cylinder 1> the attachment position of each side plate 11> each side blade 12. Mounting position> length L1a of ink-permeable region 1a> maximum pressing range length L2 of press roller 9> length position of each end of ink roller 5.

  An inclined portion 13 that is inclined toward the outside of each end portion of the plate cylinder 1 is integrally formed at the front end portion of the side blade 12 on the upstream side in the rotational direction A of the plate cylinder 1 as well shown in FIG. The lower circular arc surface 13 a of the inclined portion 13 is also formed so as to always contact the inner peripheral surface 1 d of the plate cylinder 1. In other words, the inclined portion 13 has a shape that widens toward the outside of each end portion of the plate cylinder 1.

According to the reference example 1 shown in FIGS. 1 to 3, since the side blades 12 are provided at both ends and both sides of the ink roller 5, for example, ink containing the ink reservoir 7 can be obtained by leaving the stencil printing apparatus for a long time. When the water in the ink around the roller 5 evaporates and becomes almost oil only, loses its viscosity and becomes almost liquefied, the ink is removed from the ink roller 5 and the ink reservoir 7 on the doctor roller 6 by the action of gravity. When it is about to flow down on the inner peripheral surface 1d of the cylinder 1 (the vicinity including at least the lowest inner peripheral surface 1d of the plate cylinder 1 that is stopped) and to flow on both sides of the ink roller 5, the side blade 12 Since it is possible to prevent the outflow of the almost liquefied ink 20 (shown by the two-dot chain line in FIG. 2) to the outside of the plate cylinder 1 and the printing drum 10, the plate cylinder 1 and the printing drum can be prevented. 0 is not such thing as external to the ink 20 from leaking out of. Therefore, it is possible to prevent the occurrence of user complaints that stain the inside of the stencil printing apparatus with the liquefied ink 20 or stain the printing paper.

  In addition, since the shape of the inclined portion 13 at the upstream end portion of the side blade 12 is widened and inclined outward, even if ink leaks to the outside of the side blade 12, It is possible to gather ink on the ink roller 5 side. Further, the side blade 12 includes an arcuate circumferential surface 12 a that is in an arcuate shape in contact with the inner circumferential surface 1 d in the vicinity including the lowest part of the inner circumferential surface 1 d of the plate cylinder 1, and is provided on the inner circumferential surface 1 d of the plate cylinder 1. Since the arc peripheral surface 12a of the side blade 12 in contact is limited to the range necessary for preventing the outflow of ink, the material can be saved and the contact resistance with the inner peripheral surface 1d of the plate cylinder 1 is not increased. That's it.

  The ink blocked by the side blade 12 and the ink collected by the inclined portion 13 at the upstream end of the ink are collected by the rotation of the ink roller 5 accompanying the rotation of the plate cylinder 1 and again the ink in the ink reservoir 7. The ink can be mixed and kneaded and reused without any problem, thus contributing to ink saving.

( Reference Example 2 )
FIG. 4 shows Reference Example 2 of Reference Example 1 shown in FIGS. In Reference Example 1 shown in FIGS. 1 to 3, since each side blade 12 is fixed to each side plate 11, it is worn by sliding contact with the inner peripheral surface 1d of the plate cylinder 1 due to long-term use. There is a possibility that a gap through which ink flows out is formed between the inner peripheral surface 1d and the inner peripheral surface 1d. Therefore, in order to prevent such a problem, the reference example 2 and an embodiment described later were created and invented.
The reference example 2 is different from the reference example 1 shown in FIGS. 1 to 3 in that it has a printing drum 10 </ b> A instead of the printing drum 10 compared to the stencil printing apparatus provided with the printing drum 10. The other points are the same as those of the stencil printing apparatus of Reference Example 1 shown in FIGS.

Compared with the printing drum 10 shown in FIGS. 1 to 3, the printing drum 10 </ b> A of Reference Example 2 is replaced with the ink side plate 11 </ b> A as shown in FIG. 4 instead of the side blade 12 fixed to the ink side plate 11. It is supported so as to be displaceable, and is provided inside the plate cylinder 1 outside the both ends and both sides of the ink roller 5, and contacts the peripheral inner peripheral surface 1 d including the lowest part of the inner peripheral surface 1 d of the plate cylinder 1. And a compression spring as an urging means for constantly urging each side blade 12A in a direction in contact with the inner peripheral surface 1d of the plate cylinder 1. 15 is mainly different, and the other points are the same as the printing drum 10. In FIG. 4, only one side blade 12 </ b> A disposed on the front side of the paper surface corresponding to one end portion of the ink roller 5 is shown, but the other side disposed on the back side of the paper surface. Of course, the blade 12 </ b> A is disposed corresponding to the other end of the ink roller 5.

Hereinafter, the configuration of the difference will be described in detail.
Compared with the side plate 11 shown in FIGS. 1 and 2, the side plate 11 </ b> A has a protruding spring hooking portion 11 a that locks the compression spring 15 at substantially the same position on the left and right sides across the shaft 5 a of the ink roller 5. The difference is mainly formed.

Compared with the side blade 12 shown in FIGS. 1 to 3, the side blade 12 </ b> A is not fixed by the screw 14, and the compression spring 15 is disposed at substantially the same position on the left and right sides with the shaft 5 a of the ink roller 5 interposed therebetween. The main difference is that a recessed spring receiving portion 13b is formed.
The side blade 12A is inferior in the shape of a generally crescent or fan shape in which the arcuate circumferential surface 12a of the lower portion of the side blade 12A substantially coincides with the shape of the inner circumferential surface 1d of the plate cylinder 1 so as to always contact the inner circumferential surface 1d of the plate cylinder 1. An arcuate arcuate circumferential surface 12a is provided and formed integrally. In the side blade 12A, the arc peripheral surface 12a of each side blade 12A is formed on the plate cylinder 1 by a compression spring 15 mounted between each spring hooking portion 11a of the side plate 11A and each spring receiving portion 13b of the side blade 12A. It is urged so as to always contact the inner peripheral surface 1d. The material of the side blade 12A is the same as that of the side blade 12.
In order to simplify the drawing, the illustration is omitted, but the side blades 12A are arranged in the vicinity of the spring hooks 11a of the side plates 11A so that the side blades 12A are not inclined with respect to the inner peripheral surface 1d of the plate cylinder 1. A U-shaped displacement support portion for supporting the displacement in the direction is formed.

  The position of the side blade 12A in the axial direction of the plate cylinder 1 will be described with parentheses in FIG. 2. When the end plate (not shown) of the plate cylinder 1 is attached> the attachment position of each side plate 11A> the side blades 12A. Mounting position> length L1a of ink-permeable region 1a> maximum pressing range length L2 of press roller 9> length position of each end of ink roller 5.

  At the front end of the side blade 12A on the upstream side in the rotational direction A of the plate cylinder 1, as shown in particular in parentheses in FIG. The lower circular arc peripheral surface 13 a of the inclined portion 13 </ b> A is also formed so as to always contact the inner peripheral surface 1 d of the plate cylinder 1. In other words, the inclined portion 13 </ b> A has a shape that widens toward the outside of each end portion of the plate cylinder 1.

According to the reference example 2 shown in FIG. 4, since the side blades 12A are provided at both ends and both sides of the ink roller 5, for example, when the stencil printing apparatus is left for a long time, the periphery of the ink roller 5 including the ink reservoir 7, for example. When the ink moisture evaporates and becomes almost oil only, loses its viscosity and becomes almost liquefied, the ink is transferred from the ink reservoir 5 on the ink roller 5 and the doctor roller 6 to the plate cylinder 1 by the action of gravity. When it is about to flow down on the inner peripheral surface 1d (the vicinity including at least the lowest inner peripheral surface 1d of the plate cylinder 1 that is stopped) and to flow on both sides of the ink roller 5, the plate cylinder 1 is driven by the side blade 12A. Since the outflow of the ink 20 (see FIG. 2) to the outside of the printing drum 10A is prevented and prevented, the ink 20 leaks to the outside of the plate cylinder 1 and the printing drum 10A. There. Therefore, it is possible to prevent the occurrence of user complaints that stain the inside of the stencil printing apparatus with the liquefied ink 20 or stain the printing paper.

  Since the support method of the side blade 12A including the inclined portion 13A is attached to the side plate 11A via the compression spring 15, the adhesion between the arc peripheral surface 12a of the side blade 12A and the inner peripheral surface 1d of the plate cylinder 1 is increased. Further, a more reliable ink outflow prevention effect to both sides of the ink roller 5 can be obtained.

  Further, since the arc peripheral surface 12a of the side blade 12A and the inner peripheral surface 1d of the plate cylinder 1 are always in contact with each other due to the biasing force of the compression spring 15, the arc peripheral surface 12a of the side blade 12A becomes long-term use. Although it is slightly worn, even in that case, an ink outflow prevention effect that is the same as the initial stage can be obtained.

In addition, since the shape of the inclined portion 13A of the upstream end portion of the side blade 12A is widened and inclined outward as in the case of the reference example 1 , the ink should be out of the side blade 12A. Even if it leaks out, it is possible to collect ink again on the ink roller 5 side. Further, the side blade 12 </ b> A includes an arcuate circumferential surface 12 a that is in an arcuate shape in contact with the inner peripheral surface 1 d in the vicinity including the lowest part of the inner peripheral surface 1 d of the plate cylinder 1. Since the arcuate circumferential surface 12a of the contacting side blade 12A is limited to the range necessary for preventing the outflow of ink, the material can be saved and the contact resistance with the inner circumferential surface 1d of the plate cylinder 1 is not increased. That's it.

The ink dammed up by the side blade 12A and the ink collected by the inclined portion 13A at the upstream end thereof are collected by the rotation of the ink roller 5 accompanying the rotation of the plate cylinder 1, as in the first embodiment. In addition, since it is mixed and kneaded with the ink in the ink reservoir 7 again and reused without any problem, it can contribute to ink saving.

( Embodiment )
FIG. 5 shows an embodiment of the present invention .
The embodiment shown in FIG. 5 has a printing drum 10B in place of the printing drum 10 as compared with the stencil printing apparatus provided with the printing drum 10 as compared with the reference example 1 shown in FIGS. The other points are the same as those of the stencil printing apparatus of Reference Example 1 shown in FIGS.

Compared with the printing drum 10 shown in FIGS. 1 to 3, the printing drum 10 </ b> B of this embodiment has an elastically deformable portion 12 b that can be elastically deformed as shown in FIG. 5 instead of the side blade 12. The ink roller 5 is provided inside the plate cylinder 1 outside both ends and both sides of the ink roller 5 and comes into contact with the peripheral inner peripheral surface 1d including the lowest portion of the inner peripheral surface 1d of the plate cylinder 1 to block ink. The only difference is that the ink dam member has a pair of side blades 12B, and the other points are the same as those of the printing drum 10. In FIG. 5, only one side blade 12B disposed on the front side of the paper surface corresponding to one end portion of the ink roller 5 is shown, but the other side disposed on the back side of the paper surface. Of course, the blade 12B is disposed corresponding to the other end of the ink roller 5.

In the elastic deformation portion 12b of each side blade 12B, a partially cut groove is formed so that the shape of the lower portion fixed to each side plate 11 with a screw 14 can be easily elastically deformed. Thus, the side blade 12B is characterized in that its own shape itself is provided with elasticity as the elastic deformation portion 12b in which the notch groove is formed.
The side blade 12B has a substantially crescent shape or a fan shape in which the arc peripheral surface 12a at the lower part thereof substantially coincides with the shape of the inner peripheral surface 1d of the plate cylinder 1 so as to always come into light contact with the inner peripheral surface 1d of the plate cylinder 1. An arcuate circumferential surface 12a having a sub-arc shape is provided and formed integrally.

The position of the side blade 12B in the axial direction of the plate cylinder 1 will be described with parentheses in FIG. 2. When the plate cylinder 1 is attached to each end plate (not shown)> each side plate 11 is attached> each side blade 12B. Mounting position> length L1a of ink-permeable region 1a> maximum pressing range length L2 of press roller 9> length position of each end of ink roller 5. An inclined portion 13 similar to that of the reference example 1 is integrally formed at the front end portion of the side blade 12B on the upstream side in the rotational direction A of the plate cylinder 1.

According to the embodiment shown in FIG. 5, since the side blades 12B are provided at both ends and both sides of the ink roller 5, the inner peripheral surface 1d of the plate cylinder 1 is pressed by the press roller 9 during the printing pressure operation. When each of the side blades 12B is deformed inward, the elastic deformation portion 12b absorbs the side blade 12B and follows the shape of the inner peripheral surface 1d of the plate cylinder 1. It will be possible to respond to changes in In the present embodiment , although there is no followability as much as the side blade 12A due to the urging force of the compression spring 15 in Reference Example 2 , an individual urging means / elastic member such as the compression spring 15 is not required, so that it is inexpensive. There is an advantage that it can be configured. Of course, also in the present embodiment , in the same way as in Reference Example 1 , the side cylinder 12B prevents the outflow of the ink 20 (see FIG. 2) to the outside of the plate cylinder 1 and the printing drum 10B, thereby preventing the plate cylinder. 1 and the outside of the printing drum 10B, the ink 20 is prevented from leaking, and the stencil printing apparatus is contaminated by the liquefied ink 20 or the printing paper is soiled. Needless to say, it can be prevented.

As in the above Reference Example 1 , the shape of the inclined portion 13 at the upstream end portion of the side blade 12B is a shape that spreads and inclines toward the outside, so that ink leaks out of the side blade 12B. However, it is possible to collect ink again on the ink roller 5 side. Further, the side blade 12B includes an arcuate circumferential surface 12a in an inferior arc shape that comes into contact with an inner circumferential surface 1d in the vicinity including the lowest part of the inner circumferential surface 1d of the plate cylinder 1, and is provided on the inner circumferential surface 1d of the plate cylinder 1. Since the arc peripheral surface 12a of the side blade 12 in contact is limited to the range necessary for preventing the outflow of ink, the material can be saved and the contact resistance with the inner peripheral surface 1d of the plate cylinder 1 is not increased. That's it.

The ink dammed up by the side blade 12B and the ink collected by the inclined portion 13 at the upstream end thereof are collected by the rotation of the ink roller 5 accompanying the rotation of the plate cylinder 1 as in the first embodiment. In addition, since it is mixed and kneaded with the ink in the ink reservoir 7 again and reused without any problem, it can contribute to ink saving.

When the printing drum 10B of the present embodiment was prototyped and mounted on a stencil printing machine and subjected to a durability test, the effect of preventing the ink outflow by each side blade 12B was confirmed to be almost the same as the initial after the durability test. It is done.
As test conditions at this time, the side blade 12B was made of the same resin as described above, and had a thickness of 2 mm. In addition, the height dimension of the lowest part of the side blade 12B from the lowest inner peripheral surface 1d of the plate cylinder 1 was set to about 15 mm in consideration of the maximum ink storage capacity of the ink reservoir 7. . The pressure contact force of the arc peripheral surface 12a of the side blade 12B to the inner peripheral surface 1d of the plate cylinder 1 was about 0.098 to 0.49N. The size of the plate cylinder 1 was A3 size, and the printing paper size was A3.

  By repeating continuous printing under extreme printing conditions, for example, an image area ratio of 1% / A3 or less, the water in the ink around the ink roller 5 including the ink reservoir 7 evaporates and becomes almost oil only and loses its viscosity. When the ink is almost liquefied (although it is fluid depending on the components of the emulsion ink, it is almost liquefied within one day after printing / passing through 50,000 to 60,000 sheets), the ink is transferred to the ink roller 5. And the ink reservoir 7 on the doctor roller 6 and the like by the action of gravity, the ink roller flows down onto the inner peripheral surface 1d of the plate cylinder 1 (the vicinity including at least the lowest inner peripheral surface 1d of the plate cylinder 1 that is stopped). The trouble phenomenon of trying to flow to both sides of the ink 5 tends to occur when the ink is stored in the ink reservoir 7 while being kneaded. Examples of the plate making / printing conditions corresponding to such a case include the above-described conventional examples.

The embodiment of the present invention and Reference Examples 1 and 2 have excellent advantages and effects with the above-described simple configuration. However, the present invention is not limited to this, and the following example is assumed immediately from the above-described contents. Can create. For example, the ink blade as the ink weir member is brought into contact with the inner peripheral surface 1d including at least the lowest part of the plate cylinder 1 as shown in FIGS. This is an example in which it is displaceable between a contact position that prevents outflow and a non-contact position that is spaced from the inner peripheral surface 1d and does not apply a load to the rotation of the plate cylinder 1 or the like. The displacement means in this example includes a means for guiding the ink blade to each position, a combination of a solenoid and a spring for displacing the ink blade to each position, or a drive means such as a motor. May be provided. Then, when the plate cylinder 1 is rotated, the ink blade is used to occupy the non-contact position, and when the plate cylinder 1 is stopped for a predetermined time, the ink blade is used to occupy the contact position.
In addition, it can also be configured as follows. That is, for example, when the printing cylinder 1 is rotated, the ink blade is brought into the non-contact position according to a command from a control unit (a power is always supplied) including a microcomputer having a CPU, a ROM, a RAM and a timer. The driving means is arranged so that the ink blade occupies the contact position when a predetermined leaving time of the stencil printing apparatus timed by the timer (corresponding to the time when the ink 20 is generated) is reached. (Always supply power) may be controlled.

As described above, the present invention has been described with respect to specific embodiments and reference examples . However, the technical scope disclosed by the present invention is not limited to those exemplified in the above-described embodiments . It will be apparent to those skilled in the art that various embodiments, modifications, and examples can be configured in accordance with the necessity and application within the scope of the present invention. .

  The present invention can be applied to apparatuses other than the stencil printing apparatus, for example, a double-sided printing apparatus using the stencil printing method described in Japanese Patent Application Laid-Open No. 2003-200355 and Japanese Patent Application Laid-Open No. 2003-31914. It can also be applied to or applied mutatis mutandis to a printing apparatus that can also be called a dedicated printing machine described in Japanese Patent No. 229736.

It is a partial cross section front view of the principal part around the printing drum of the printing drum which shows the reference example 1 of this invention, an ink roller, and a side blade. FIG. 4 is an enlarged vertical cross-sectional view of a main part passing through the axial center of the ink roller of Reference Example 1 . It is a perspective view of the principal part shown to the arrangement state of the internal peripheral surface of the plate cylinder of the said reference example 1 , and the inclination part of a side blade. It is a partial cross section front view of the principal part around the plate cylinder of a printing drum, an ink roller, and a side blade which shows the reference example 2 of the said reference example 1. FIG. It is a partial cross section front view of the principal part around the plate cylinder of a printing drum, an ink roller, and a side blade which shows embodiment of this invention . 1 is a schematic front view of an entire stencil printing apparatus including a printing drum to which the present invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plate cylinder 1a Ink permeability area 1d Inner peripheral surface of plate cylinder 2 Master (heat-sensitive stencil paper)
4 Ink supply device 5 Ink roller (ink supply member)
6 Doctor roller (ink metering member)
10B printing drum (stencil printing drum)
11 Side plate
12B side blade (ink weir member)
Inclined portion 13 Sa id blade (upstream tip)
P Printing paper Y Plate cylinder axis direction, paper width direction, master width direction

Claims (3)

A plate cylinder provided with an ink-permeable region, and is rotatable around an axis provided in the plate cylinder and parallel to the central axis of the plate cylinder; An ink supply member that supplies ink of an O-type emulsion ink system, and an ink reservoir formed between the ink supply member and the ink supply member that are arranged in parallel with a minute gap therebetween. In a stencil printing drum comprising an ink metering member that forms a substantially constant ink layer on the outer peripheral surface,
Provided inside the plate cylinder outside both ends of the ink supply member, and has a pair of ink dam members that contact the inner peripheral surface in the vicinity including the lowest part of the inner peripheral surface to block ink. ,
Each of the ink weir members has an inferior arc-shaped peripheral surface that is in contact with the inner peripheral surface in the vicinity including the lowest part of the inner peripheral surface, and a tip portion on the upstream side in the rotational direction of the plate cylinder in the ink dam member. An inclined portion inclined toward the outside of each end of the plate cylinder, and an elastic deformation portion that has elasticity and can be elastically deformed,
The upper part of each ink weir member is formed in a step shape in the vertical direction when viewed from the axial direction of the ink supply member,
Maximum pre height to the lowest portion of said stepped shape of the inner peripheral surface lowest from the each ink dam member of the bottom of each ink dam member contacts is to liquefaction in reservoir above the ink It is set in consideration of the ink storage capacity,
Each ink dam member is viewed from the axial direction of the ink supply member, formed at a height that the top of the extension line of said stepped shape of said each ink dam member overlaps the axis of the ink supply member And the tip of the ink weir member that is in contact with the inner peripheral surface and the rear end on the downstream side in the rotational direction of the plate cylinder are the intersections of the uppermost extension line and the inner peripheral surface. And a stencil printing drum configured to contact the inner peripheral surface by elastic deformation by the elastic deformation portion. The stencil drum according to claim 1,
A stencil printing drum comprising biasing means for biasing each of the ink weir members in a direction in contact with the inner peripheral surface.   A stencil printing apparatus comprising the stencil printing drum according to claim 1 or 2, wherein ink is supplied from the inner peripheral surface side to a stencil master which is wound on the stencil printing drum. .

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