JP2007190916A - Printing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure the uniform transfer from a doctor type ink grooves to a roller. <P>SOLUTION: The printing machine includes an ink device including a roller 3, a rear wall 8 whose position can be adjusted for adjusting the ink level 15 of a printing ink 14 stored in a doctor type ink groove 4, and the doctor type ink groove 4 associated with the roller 3. The rear wall 8 has a fluid crosssection portion 9 for exerting hydrodynamic influence on the printing ink 14. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention includes a roller according to the premise of claim 1 and a doctor-type ink groove attached to the roller, the doctor-type ink groove for adjusting the ink level of the printing ink stored in the roller. The present invention relates to a printing press provided with an inking device including an adjustable rear wall.

Patent Document 1 describes such a printing machine. In this prior art printing machine, the roller is a screen roller and the printing ink is transferred from the doctor-type ink channel to the screen roller, i.e. in some situations it is not evenly uniform and the printing ink is transferred to the ink cell of the screen roller. Is filled. The filling of the ink cells may depend on the printing speed, and may be adversely affected by disturbing turbulent flow of the printing ink stored in the doctor type ink groove and bubbles of the printing ink.
US Patent Application Publication No. 6,705,223B2

  It is therefore an object of the present invention to provide a printing machine belonging to the field mentioned at the beginning, in which a uniform transfer of printing ink from the doctor-type ink groove to the roller is guaranteed.

  This object is achieved by a printing press comprising the features of claim 1. And a doctor-type ink groove attached to the roller, the doctor-type ink groove being a position-adjustable rear wall for adjusting the ink level of printing ink stored in the doctor-type ink groove A printing press according to the invention comprising an inking device comprising a fluid is characterized in that the rear wall has a fluid cross-section (Stromungsprofil) that affects the printing ink hydrodynamically.

  The fluid cross section may be attached to the rear wall when constituted by a plurality of portions, or may be integrally formed on the rear wall when constituted integrally. In the context of the present invention, printing ink also means varnish and inking device also refers to a varnishing unit.

  One advantage of the fluid cross section is that it improves the uniformity of printing ink transfer from the bladed ink channel to the roller. The uniformity does not depend greatly on the printing speed. Turbulence that impairs uniformity and bubbles in printing ink are reduced to a sufficient level. When the roller is configured as a screen roller having a screen structure composed of ink cells, for example, the filling of printing ink into the screen structure, so-called ink cell filling, is made uniform by the hydrodynamic action of the fluid cross section.

  Another advantage is that the hydrodynamic action of the fluid cross-section on the printing ink can be performed without disturbing accompanying effects on the bottom of the doctor or doctor-type ink groove. The hydrodynamic force exerted from the printing ink on the fluid cross section by the dynamic pressure of the printing ink staying in front of the fluid cross section is released from the fluid cross section through the rear wall. The rear wall is connected to the groove bottom by a joint, i.e. a straight joint or in particular a rotary joint, so that hydrodynamic forces received by the rear wall are transmitted to the groove bottom and the doctor attached to it. Absent.

  Yet another advantage is that positioning the rear wall away from the roller provides very good access to the fluid cross-section, and thus can be easily cleaned when changing the printing ink.

  Advantageous developments of the printing press according to the invention are described in the dependent claims.

  In one development, the rear wall is at a first position where the ink level is above or above the doctor blade edge of the doctor ink fountain doctor, and the ink level is at the doctor ink fountain doctor. The second position below or below the doctor blade edge is supported so as to be selectively adjustable. The doctor blade edge forms a point located at the highest point of the doctor.

  In another development, the rear wall is supported so that it can swing to a first position and a second position about the rotary joint, which is above the bottom of the doctor-type ink channel. Is arranged.

  In another development, the fluid cross section and the circumferential surface of the roller jointly form a constriction above the doctor blade edge when the rear wall is in the first position.

  In another development, the fluid cross-section has an outer corner that defines a narrow portion with an angle greater than 45 ° and less than 135 °. In particular, this angle may be greater than 60 ° and smaller than 120 °. The angle of the outer corner is preferably about 90 °, i.e. the outer corner is substantially perpendicular.

  In another development, the fluid cross section has an inner corner. The inner corner can have an angle that is at least 90 °. This angle may be about 135 °.

  In another development, at least one member is provided to ensure a good contact between the rear wall and the film. This film is inserted into the doctor-type ink groove so as to cover at least the groove bottom.

  In another development, the member is a cushion disposed between the film and the bottom of the doctor-type ink channel. The cushion may be a solid cushion such as a plastic cushion. In this case, the cushion may be foamed. The film and the cushion may be integrally made of a composite material. Alternatively, the film and cushion may be made in two parts, in which case the film rests on the cushion in a doctor-type ink channel.

  In another development, the film is configured as a disposable item that can be periodically disposed when cleaning the doctor-type ink fountain. At the time of ink change, the printing ink used for the previous print job is removed from the doctor-type ink channel, and the film is then removed from the doctor-type ink channel with the remaining ink on it and discarded. Insert a new unused film into the doctor-type ink channel, and then fill the doctor-type ink channel with the printing ink required for the next print job.

  In another development, the rear wall has a hard sliding surface of metal, and the rear wall abuts the film at this sliding surface to establish contact.

  In another development, the film and the back wall together divide the boundaries of the offset printing ink reserve, formed by printing ink, stored in a doctor-type ink channel. The printing ink stored in the doctor type ink groove is particularly highly viscous.

  In another development, the groove bottom surface facing the film is concavely curved.

  In another development, the inking device is an anilox inking device and the roller is a screen roller.

  Next, embodiments of the present invention will be described with reference to the drawings.

  The printing machine 1 includes an anilox ink device 2 that includes a screen roller 3 and a doctor ink groove 4 having an ink groove 5 and a doctor 6. The doctor 6 is attached to the ink groove 5 by means of a clamping device 25 configured as a quick lock (Schnellverschluss).

  The ink groove 5 includes a rear wall 8 attached to the side wall 26 of the ink groove 5 by a rotary joint 13. The dish-shaped groove bottom 7 of the ink groove 5 is curved in an arc shape, and has a surface 23 whose center of curvature is the rotary joint 13. The point located at the highest position of the doctor 6 is formed by a doctor blade edge 16 that contacts the screen roller 3 during a printing operation.

  The inside of the ink groove 5 is lined with a film 17 made of plastic such as polyethene (PE) or polyethylene terephthalate (PET). The film 17 may have an oleophobic surface that repels printing ink, that is, an anti-adhesive surface. The end portion of the film 17 is bent substantially in a U shape, and the hook-like portion of the front end portion forms a set that is sandwiched by the clamp device 25 together with the doctor 6. The rear end portion of the film 17 also forms a hook 19 that is hooked on the protruding portion 20 disposed in the ink groove 5 for fixing.

  The rear wall 8, the film 17, the side wall 26, and the side wall 26 of the ink groove 5 facing this together form the boundary of the offset printing ink reserve 14 stored in the doctor type ink groove 4. Naturally, instead of the offset printing ink reserve 14, another printing ink reserve having a viscosity as high as the offset printing ink may be stored.

  The ink level 15 formed by the offset printing ink reserve 14 by the swing of the rear wall 8 toward the doctor 16 performed around the rotary joint 13 causes the ink level 15 to be above the doctor blade edge 16. It rises until This increase in the ink level 15 takes place after the doctor 6 has been pressed against the screen roller 3 with a negative pressing angle for the printing operation. The first position where the rear wall 8 is held during the printing operation is shown in FIG. 1b. In this first position, the capacity of the doctor-type ink groove 4 is reduced compared to the second position of the rear wall 8 (see FIG. 1a). As a result, the offset printing ink reserve 14 is reduced to the doctor. If the doctor-type ink groove 4 is not pressed against the screen roller 3, it will flow out. For example, for the purpose of replacing the offset printing ink reserve 14, the rear wall 8 is in the second position and the ink level 15 is higher than the doctor blade edge 16 in order to move the doctor-type ink groove 4 away from the screen roller 3. The ink level 15 is lowered by the swinging of the rear wall 8 performed away from the doctor 6 until it comes down. After the ink level 15 is lowered in this way, the offset printing ink reserve 14 does not flow out when the doctor-type ink groove 4 is separated from the screen roller 3.

  The rear wall 8 has, at its free end, a sliding surface 12 that slides on the film 17 when the rear wall 8 swings. The sliding surface 12 is made of the same metal from which the other parts of the rear wall are entirely made, for example steel or in particular aluminum. In order to ensure a permanent and elastic contact between the rear wall 8 and the film 17 and to prevent printing ink from passing between the rear wall 8 and the film 17, an elastic or springy member is provided. Is provided.

  This member is made of a plastic foam such as polyethylene terephthalate foam (PET foam) or ethylene / propylene / diene rubber foam (EPDM foam), and is disposed as an underlay of the film 17 between the film 17 and the concave surface 23 of the groove bottom 7. Solid cushion 22. The solid cushion 22 and the film 17 can be sequentially inserted into the doctor-type ink groove 4, or alternatively, can be assembled into a sandwich structure and collectively inserted into the doctor-type ink groove 4.

  The solid cushion 22 is compressible to press the film 17 against the rear wall 8 in either the first position or the second position of the rear wall 8 and any intermediate position located between both positions. is there. In FIGS. 1 a and 1 b, the effect of the initial load exerted by the solid cushion 22 is illustrated as a small reversible deformation of the film 17 and the solid cushion 22 in the region of the sliding surface 12. The sliding surface 12 bites into the solid cushion 22 a little, and the solid cushion 22 and the film 17 on the solid cushion 22 form a small depression that returns to the original state when the load is removed in the region of the sliding surface 12.

  In FIGS. 1 a and 1 b, the rear wall 8 has a fluid cross-section 9 facing the screen roller 3, located at the lower end of the rear wall 8, opposite the rotary joint 13. It shows a state. The fluid cross section 9 has an outer corner 11 forming an edge extending perpendicular to the plane of the paper of FIGS. 1a and 1b. This edge may have a slight rounding or chamfer. The angle α of the outer corner 11 is almost a right angle. Furthermore, the fluid cross section 9 has an inner corner 21 with an angle β which is an obtuse angle. The outer corner 11 is between the rotary joint 13 and the inner corner 21. The inner corner 21 is between the outer corner 11 and the sliding surface 12.

  When the rear wall 8 is positioned so as to approach the screen roller 3 for a printing operation (see FIG. 1b), the outer corner 11 is the region of the fluid cross section 9 closest to the screen roller 3. However, at this time, the fluid cross section 9 and its outer corner 11 are not in contact with the screen roller 3 but are in the immediate vicinity thereof. That is, the outer corner 11 forms a narrow portion 10 together with the circumferential surface of the screen roller 3. In the region of the inner corner 21, the rear wall 8 forms a printing ink subchamber located below the outer corner 11. Above the outer corner 11 is a printing ink main chamber having a larger storage volume than the printing ink subchamber.

  FIG. 2 shows a state in which a positioning pin 27 that serves to align the doctor-type ink groove 4 with respect to the screen roller 3 is attached to one side wall 26. The positioning pin 27 has a substantially bone-shaped cross-sectional shape. On the other side wall 26, a link pin 28 protruding downward and a half-plate shaped joint socket 29 are arranged. The link pin 28 engages a link hole in a machine side frame or a component attached thereto. The side frames of the machine and the components attached to it are not shown in the drawings for the sake of clarity. The link socket 29 is supported on a joint pin attached to the machine side frame, also not shown in the drawing, so that these four components constitute a rotary joint 30 with a vertical geometric rotation axis. is doing.

  For maintenance purposes, the entire doctor-type ink channel 4 can be swung away from the screen roller 4 around the rotary joint 30, ie in a horizontal plane. The link pin 28 and the link socket 29 make it possible to remove the doctor-type ink groove 4 from the printing machine 1 without a tool. For this purpose of removal, the doctor-type ink groove 4 is lifted upward until the link pin 28 is pulled out of the link hole. In other words, the rotary joint 30 enables the removal of the doctor-type ink groove 4 from the printing press, which should be performed for maintenance purposes, and the attachment of the doctor-type ink groove 4 in the subsequent re-use. To do.

  On the side of the doctor-type ink groove 4 facing away from the rotary joint 30, a joint 24 for drivingly connecting the rear wall 8 to the actuator is disposed. The actuator is not shown in the drawing and may be a pneumatic working cylinder or an electric motor with a helical gear with a threaded spindle in front. The actuator is also moved by a lever, not shown in the drawing, when the joint half arranged on this lever engages the joint half of the joint 24 arranged on the rear wall 8 and not shown in the drawing. Drive connected to the wall 8. A joint 24 composed of both joint halves is a meshing joint and is arranged coaxially with the rotary joint 13. When the actuator is configured as a working cylinder, the piston rod is pivotally connected to the lever described above, and when the actuator is configured as an electric motor, the lever is connected to a helical gear disposed in front of the piston rod. Match. The swinging motion of the lever driven by the actuator is transmitted to the rear wall 8 by the joint 24, and selectively moves the rear wall 8 to the first position (see FIG. 1b) or the second position (see FIG. 1a). Adjust the position.

  The fluid cross section 9 causes a dynamic pressure of the printing ink in the region of the narrow portion 10 when the printing ink is conveyed toward the narrow portion by the rotation of the screen roller 3. As a result of this dynamic pressure, the screen recesses (ink cells or grooves) of the screen roller 3 are filled very evenly with almost no air contamination.

  As a result of the aforementioned dynamic pressure, a force acts on the rear wall 8, and this force presses the rear wall 8 away from the screen roller 3, with the rotating joint 13 as the center, as viewed in FIG. Try to rock. This force is released from the rear wall 8 through the joint 24 and the lever described above to the actuator that receives the force described above. This force is not received by these because the rear wall 8 and the side wall 26 are movably connected (rotary joint 13), and is transmitted from these to the groove bottom 7 attached to the side wall 26, Since it is not transmitted from the groove bottom 7 to the blade 6 attached to the groove bottom 7 by the clamping device 25, bending and deformation of the groove bottom 7, the clamping device 25, and especially the doctor 26 caused by the flow of force. Is reliably avoided, and the doctor contacts the screen roller 3 evenly over the entire printing width.

FIG. 5 shows a doctor-type ink channel having an adjustable rear wall with a fluid cross-section that is adjusted to a maintenance position drawn from a roller. FIG. 7 shows a position-adjustable rear wall with a fluid cross section in an operating position close to a roller. It is the three-dimensional figure which looked at the doctor type ink groove from back.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printing machine 2 Anilox type ink apparatus 3 Screen roller 4 Doctor type ink groove 5 Ink groove 6 Doctor 7 Groove bottom part 8 Rear wall 9 Fluid cross-section part 10 Narrow part 11 Outer corner 12 Sliding surface 13 Rotary joint 14 Offset printing ink stockpile 15 Ink level 16 Blade edge 17 Film 19 Hook 20 Protruding portion 21 Inner corner 22 Solid cushion 23 Surface 24 Joint 25 Clamping device 26 Side wall 27 Positioning pin 28 Link pin 29 Link socket 30 Rotating joint α Angle β Angle

Claims (15)

Printing ink stored in the doctor-type ink groove (4), comprising a roller (3) and a doctor-type ink groove (4) attached to the roller (3). In a printing press comprising an inking device comprising an adjustable rear wall (8) for adjusting the ink level (15) of (14),
Printing machine, characterized in that the rear wall (8) has a fluid cross section (9) that hydrodynamically affects the printing ink (14).   The back wall (8) is moved to a first position where the ink level (15) is above the doctor blade edge (16) of the doctor (6) of the doctor-type ink groove (4) and the ink level The printing press according to claim 1, wherein (15) is supported so as to be selectively adjustable to a second position below said doctor blade edge (16).   The rear wall (8) swings to the first position and the second position around a rotary joint (13) disposed above the groove bottom (7) of the doctor-type ink groove (4). The printing press according to claim 2, which is movably supported.   The fluid cross section (9) and the roller (3) form a narrowed section (10) above the doctor blade edge (16) when the rear wall (8) is in the first position. The printing press according to claim 2 or 3.   The fluid cross section (9) has an angle (α) greater than 45 ° and less than 135 ° and has an outer corner (11) defining the narrowed portion (10). Printing machine.   The printing press according to claim 5, wherein the angle (α) of the outer corner (11) is about 90 °.   The printing press according to any one of the preceding claims, wherein the fluid cross section (9) has an inner corner (21).   Printing press according to claim 7, wherein the inner corner (21) has an angle (β) which is at least 90 °.   Printing machine according to any one of the preceding claims, wherein at least one member is provided for ensuring a contact established between the rear wall (8) and the film (17).   The printing machine according to claim 9, wherein the member is a cushion (22) disposed between the film (17) and a groove bottom (7) of the doctor-type ink groove (4).   11. The printing press according to claim 10, wherein the film (17) is a disposable product that can be disposed of periodically when washing the doctor-type ink channel (4).   The rear wall (8) has a hard sliding surface (12) of metal, and the rear wall (8) contacts the film (17) with this sliding surface to establish the contact. The printing press according to any one of claims 9 to 11, which contacts the printing press.   The film (17) and the rear wall (8) form a boundary of an offset printing ink reserve (14) formed by the printing ink stored in the doctor-type ink groove (4). Item 13. The printing machine according to any one of Items 9 to 12.   14. A printing press according to any one of claims 10 to 13, wherein the surface (23) of the groove bottom (7) facing the film (17) is curved concavely.   The printing machine according to any one of claims 1 to 14, wherein the inking device is an anilox inking device (2) and the roller is a screen roller (3).

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