[0036] First, in conjunction with Figure 8~ Picture 10 Explain the structure of the offset printing machine. In this embodiment, the type of the printing unit is an offset printing press that supplies water and ink separately.
[0037] In Figure 9 and Picture 10 Here, the sheet separating and feeding device 1 separates and feeds the sheets (paper sheets such as business cards, cards, envelopes, etc., plastics, etc.) S stacked in the storage section from the uppermost side one by one. The sheet conveying device 2 feeds the separated sheet S to the printing section 3 at a predetermined time. The sheet conveying device is provided with conveying claws (not shown) that abut on the rear end of the sheet S and feed the sheet into the printing section, and several pressure rollers 4 arranged in line in the conveying direction of the sheet S . The printing section 3 may perform monochrome printing on the sheet S, and of course may also perform color printing. Using an image scanner (not shown), the image data of the printing plate read for each color or the image data of the printing plate prepared by a personal computer is printed in each color by the printing section. The printed sheet S is discharged to the discharge section 5. An operation panel 7 is provided on the front part of the main body 6 of the apparatus, and the number of printing sheets, printing speed, ink density, etc. can be arbitrarily set on the top of the operation panel 7.
[0038] In FIG. 8, the schematic structure of the printing unit 3 is explained. The ink pot 11 stores ink of any one color of M (magenta), C (blue), Y (yellow), and K (black). In addition, the ink ejection roller 12 supplies the ink stored in the ink pot 11 to the ink distributor 13 arranged on the downstream side. The ink dispenser 13 adjusts the ink supply amount by alternately contacting and separating actions between the ink ejection roller 12 and the ink delivery roller 14.
[0039]The ink supplied to the ink conveying roller 14 is mixed by the ink mixing roller group 15 arranged in pressure contact with each other on the downstream side, so as to prevent the ink from being stretched to form ink twists and forming a striped pattern. This mixed printing ink is supplied to the plate surface of the plate body 17 via the ink roller 16 provided at two places. The water stored in the water pan 18 is sucked out by the suction roller 19, is conveyed by the water delivery roller 20, and is supplied to the plate surface of the plate body 17 by the water addition roller 21.
[0040] The plate body 17 has a printing plate wound on the peripheral surface of a roller, and the ink image applied on the printing plate is transferred to the roller sleeve body 22. The printing plate, for example, is formed by exposing the original picture film, and then the printing image printed on the sheet S is processed. The inking roller 16 and the absorbing roller 21 can contact and leave the plate body 17. When printing starts, they will contact the plate body 17 at a predetermined time and supply printing plate water and ink to form an ink image.
[0041] In the roller sleeve body 22, a rubber roller sleeve is wound around the peripheral surface of a metal roller. Both end sides of the roller cover are fixed to the opening part of the roller by a clamp with screws. The plate body 17 contacts and leaves the roller sleeve body 22, and the ink image formed on the printing plate is transferred onto the roller sleeve. The pressing body 23 uses a metal roller. The pressing body 23 makes contact with and moves away from the roller sleeve body 22, and forms a nip portion with the roller sleeve body 22. When the sheet S passes through the nip portion, the ink image is transferred by the roller sleeve.
[0042] The roller sleeve body 22 is fixed, and the plate body 17 and the pressing body 23 perform contact and separation actions at a predetermined time. In the case of this embodiment, once the printing starts, first, the plate body 17 is pressed against the roller sleeve body 22 (into the plate press), and then the press body 23 is pressed against the roller sleeve body 22 (into the press press), and the device During operation, the pressing body 23 and the roller sleeve body 22 are kept in pressure contact state, and each time the printing ends, the plate body 17 is moved away from the roller sleeve body 22 (the plate pressure is released). In addition, when the operation of the device is stopped, the pressing body 23 is moved away from the roller sleeve body 22 (the printing pressure is released).
[0043] Using an image scanner not shown, based on the read image data of the printing plate or the image data of the printing plate prepared by a personal computer, an ink image is formed on the plate body, and the ink image is transferred to the plate body 17 After the roller sleeve body 22 is applied, the ink image is transferred to the sheet S conveyed between the roller sleeve body 22 and the pressing body 23. The sheet S is fed into the nip part by the sheet conveying device 2 provided on the upstream side of the nip part between the roller sleeve body 22 and the pressing body 23 in synchronization with the ink image transferred on the roller sleeve. The sheet S stacked in the storage section is separated and fed one by one by the sheet separation and supply device 1, and the sheet S is fed by the sheet transport device 2 to the printing section 3 along the transport table 24. The sheet S on which the ink image has been transferred in the printing unit 3 is discharged to the discharge unit 5.
[0044] Below, combined figure 1 ~ Figure 7, the structure of the sheet separation and supply device 1 in detail.
[0045] in figure 1 In the storage section 25, the sheet S is stacked on the lift table 26. On the device racks 43 on both sides, an endless chain 27 is hung between sprockets 28 arranged up and down. A part of the elevating table 26 is connected to the sprocket 27. The forward and reversible elevating motor 29 shown in FIG.
[0046] The suction unit 30 sucks and holds the sheet S stacked on the lift table 26 on the suction cup 31. The suction cup 31 is supported at two places by support rods 32 provided along the width direction of the sheet S (see FIG. 7C). in figure 2 Here, the support rod 32 is connected to the tip side of the swing arm 34 that swings around the arm shaft 33 as the center.
[0047] in figure 1 In this case, when the suction cup 31 is performing an empty suction operation, the suction opening 31a extends downward to be able to contact the uppermost sheet S. When the sheet S is sucked, the suction port 31a is pulled upward to suck and hold the sheet S. The suction part 30 is sucked and supplied to the sheet conveying device 2 one by one from the uppermost side from the front side part of the sheet S stacked on the lift table 26. The sheet conveying device 2 is provided with a conveying belt 35 and a driven roller 36, and the tip end of the sheet S sucked and held by the suction pad 31 is supplied to the nip between the conveying belt 35 and the driven roller 36, and then is conveyed to the downstream side.
[0048] in figure 2 In, an explanation will be given on the adsorption and movement mechanism. The eccentric cam 37 is rotatably provided on the sheet separation and supply device 1 with the cam shaft as the center. The eccentric cam 37 is driven and transmitted from the side of the device main body 6 to rotate. Specifically, the device main body 6 is provided with a clutch 39, and by connecting the clutch 39 at a predetermined time, the clutch gear 40 provided coaxially with the clutch 39 rotates. At this time, the cam gear 41 meshed with the clutch gear 40 rotates, and the eccentric cam 37 provided coaxially with the cam gear 41 rotates. The swing arm 34 is applied with a force that constantly contacts the eccentric cam 37. Specifically, the swing arm 34 is rotatably arranged around the arm shaft 33 connected to the lower end side thereof, and the torsion coil spring 44 is connected to the upper end side thereof. The other end of the torsion coil spring 44 is fixed on the device frame 43. The swing arm 34 receives the torsion coil spring 44 figure 2 The eccentric cam 37 is always in contact with the eccentric cam 37 by applying force in the direction of the arrow. During one revolution of the eccentric cam 37, the swing arm 34 swings, and the support rod 32 supported on the upper end side of the swing arm 34 reciprocates. At this time, the suction cup 30 supported by the support rod 32 reciprocates between the supply device that transfers the sheet S to the sheet conveying device 2 and the suction position where the sheet S can be sucked and held. (see figure 1 ).
[0049] Below, combined Figure 2~Figure 4 Explain the air suction mechanism. In Figure 4, the air suction valve 45 is provided on the air suction line 47 connecting the air suction pump (dry pump) 46 and the adsorption part 30. The air suction valve 45 adopts a mechanical valve. In addition, a blower (blower outlet) 56 is connected to the air suction pump 46 through a blower duct 48. The air blowing section 56 blows air to the upper part of the front end side of the sheet S stacked on the storage section 25 to blow the sheet S apart.
[0050] in figure 2 Among them, the air suction valve 45 is provided with a valve body 49 in a part of the air suction line 47 passing through the vicinity of the eccentric cam 37. in Figure 3A In B, a valve arm 50 is provided near the valve body 49, and the valve arm 50 is swingable with the arm shaft 51 as the center. The valve arm 50 is provided with a pipe connection portion 52 leading to the air suction pump 45.
[0051] in Figure 3A Here, the valve arm 50 is constantly urged by the torsion coil spring 53, and the pipe connecting portion 52 is connected to the valve body 49. In addition, the valve arm 50 is provided with a cam follower 54 with which the eccentric cam 37 can abut. in Figure 3B When the eccentric cam 37 rotates and the cam surface abuts against the cam follower 54, the valve arm 50 resists the urging force of the torsion coil spring 53, and rotates counterclockwise in the opposite direction. At this time, the connection between the pipe connection portion 52 and the valve body 49 is released. Thus, during one revolution of the eccentric cam 37, the opening and closing of the air suction valve 45 is switched to achieve Figure 3A The state suction part 30 suction and hold the sheet S; Figure 3B The suction of the sheet S held by suction is released. The suction part moving mechanism and the air suction mechanism are driven by the same drive transmission mechanism (clutch 39, clutch gear 40, cam gear 41) from the side of the device body 6, and are connected with the reciprocating movement of the suction part 30 to perform the air suction valve 45 The opening and closing.
[0052] In FIGS. 7A to 7C, on the cam shaft 38 of the eccentric cam 37, a weight 55 corresponding to the eccentric portion is coaxially provided. Once the clutch 39 on the body side of the device stops driving transmission to the eccentric cam 37, the eccentric cam 37 stops at a predetermined position by the weight ( figure 2 The position of the solid line). In this way, when the separation and supply operation is suspended such as the exchange of the sheet S or the printing operation is stopped, the suction unit 30 can be automatically returned to the original position, which facilitates maintenance work.
[0053] again Figure 5A In B, the storage section 25 is provided with a positioning mechanism for positioning the sheet S stacked on the lift table 26; a separation mechanism for improving the separation and arrangement of the sucked sheet S, and the like. Specifically, the positioning guide arm 58 and the pressing guide arm 59 are installed so as to be rotatable around the fulcrum 60 provided on the device frame 43 (see Figs. 7B and C). The pressing guide arm 59 is connected to the positioning guide arm 58 and is rotatable with the rotating shaft 61 as the center. A suspension arm 62 is slidably provided on the positioning guide arm 58 at the center. On the lower end side of the suspension arm 62, a pressing spring 63 that presses the sheet S stacked on the lifting table 26 is provided. The pressing spring 63 is a plate spring that urges the rear end side of the sheet S to the front end side, and pushes the sheet S to the positioning plate 64 to be flush. The position of the pressing spring 63 can be adjusted according to the size of the sheet. Loosen the adjusting bolt 65 to make the suspension arm 62 slide along the length of the positioning guide arm 58, and then tighten the adjusting bolt 65 to adjust. In addition, a separation claw (plate spring) 66 is provided near the positioning plate 64 to prevent the sheet S sucked and held by the sucking portion 30 from being overlapped and conveyed. A blower 56 is arranged in parallel near the separation claw 66, and blows air at the upper part of the front end side of the sheet S, so that the sheet S can be easily arranged.
[0054] In addition, on one end side of the pressing guide arm 59, the mounting portion 68 is slidably provided with a sheet pressing portion (pressing lever) for pressing the upper surface of the uppermost sheet S stacked on the lifting table 26 on the rear end side. ) 67. The position of the pressing portion 67 can be adjusted. After loosening the adjusting bolt 69 and sliding the mounting portion 68 along the length direction of the pressing guide arm 59, the adjusting bolt 69 is tightened (see FIG. 7C). Such as Figure 5A As shown by the two-dot chain line, the sheet pressing portion 67 moves in accordance with the change in the load amount of the sheet S, and the pressing guide arm 59 rotatably follows the rotation shaft 61 as the center. In addition, when the margin of the sheet S decreases, the lifting platform 26 rises, so it is sufficient that the rotation range of the pressing guide arm 59 is small. Again, such as Figure 5B As shown by the two-dot chain line, when supplementing the sheet S stacked on the lifting platform 26, the positioning guide arm 58 and the pressing guide arm 59 can also be rotated clockwise around the fulcrum 60 to make the lifting platform 26 After the upper side of the opening is opened, work is carried out.
[0055] in Figure 6A In B, the upper limit position of the lifting platform 26 is detected by the position sensor 71 attached to the link member 70. The up and down position of the position sensor 71 can be moved up and down in the bolt mounting portion 73 provided in the device frame 43 by rotating the height adjustment bolt 72 in a predetermined direction, and the position sensor 71 can be moved up and down through the connecting rod member 70 (see FIG. 7A, B). By adjusting the upper limit height of the lifting platform 26, the pressing force of the sheet pressing portion 67 and the degree of easy traversal of the separation claw 66 can be finely adjusted according to the type (rigidity) of the sheet S, thereby stabilizing the separation and feeding operation of the sheet S.
[0056] In FIG. 8, the sheet S separated from the storage unit 25 is conveyed to a predetermined position by the sheet separation and supply device 1 and the sheet S is conveyed to a predetermined position by the sheet conveying device 2. The rear end is kept in contact, and is fed to the printing section 3 for printing at a predetermined time.
[0057] With the above-mentioned sheet material separation and supply device 1, the driving force supplied from the device body 6 is connected or disconnected at a predetermined time through the clutch 39 and the eccentric cam 37. Even if the size and type of the sheet material S are changed, the drive force can be connected to the device body 6 The feeding time of the sheet S is arbitrarily adjusted on the side, and the responsiveness to the printing speed of the printing section 3 is fast, which facilitates high-speed printing (eg, 8000 sheets/hour). In addition, the air suction valve 45 can be opened and closed in connection with the reciprocating movement of the suction unit 30, so expensive rotary valves and pressure regulating valves are not required, and the device structure can be simplified and the device cost can be reduced.
[0058] Above, the best embodiment of the present invention has been described. However, the present invention is not limited to the above-mentioned embodiments. For example, the number of suction parts 30 can be arbitrarily increased or decreased, and the structure of the sheet conveying device 2 is also arbitrary. The offset printing machine is not only a printing machine with one printing section 3, but also a printing machine with several full-color printing. In addition, the printing press to which the sheet separating and supplying device 1 is applied is not limited to an offset printing press, but may be other types of printing presses, etc., and various changes can be implemented without departing from the scope of the present invention.
