JP2011005686A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer capable of accurately correcting an ejection timing of a spray device, without providing a special sensor.SOLUTION: The extension amount of each of chains 4c and 6c is measured by detecting two gripper shafts of the chain 6c by a sheet-passage detection sensor 40 disposed in a paper discharge section 6, and then, the ejection timing of the spray device 50 disposed in the paper discharge section 6 is corrected.

Description

  The present invention relates to a printing machine, and more particularly to correction of ejection timing of a spray device.

  A printing machine 1 shown in FIG. 1 includes a varnish coating device 5 that coats paper with a varnish in order to prevent the printed sheet from being damaged or to improve the appearance. This printing machine 1 is composed of units that follow a paper feed unit 2, a printing unit 3, a transport unit 4, a varnish coating device 5, and a paper discharge unit 6 from upstream to downstream in the sheet transport direction. . The transport unit 4 has a chain inside, and transports the sheet from the printing unit 3 to the varnish coating apparatus 5. The sheet coated with the varnish by the varnish coating device 5 is conveyed from the varnish coating device 5 to above the paper discharge pile by a chain inside the paper discharge unit 6.

  Since the sheet discharge unit 6 stacks the sheets on the sheet discharge pile, spray powder is uniformly distributed on the sheet with a spray device in order to prevent the ink from turning over. In order to dispense with the waste of the spray powder and to disperse it efficiently, it is important to issue an injection command to the spray device by grasping the timing (injection timing) at which the leading edge of the sheet arrives under the spray nozzle of the spray device.

  However, as pointed out in Patent Document 1, there is a problem that the chain is extended and lengthened if the printing press is used for a long time. In particular, since the chain built in the transport unit 4 has a role of driving each unit on the downstream side, the load is easily increased.

JP 2008-132777 A

  When the chain is extended, the sheet being transported by the chain will pass under the spray device earlier than when the chain is not extended, and spray powder cannot be sprayed onto the sheet accurately. It was.

  The present invention solves the above problem and provides means capable of accurately correcting the injection timing of the spray device without providing a special sensor.

  The paper discharge unit 6 is provided with a sheet passage detection sensor 40 for detecting the fall of the sheet being conveyed. In order to achieve the above object, the sheet passage detection sensor 40 is provided with the sheet passage detection sensor 40. Utilizing this, the elongation of the chains 4c and 6c was measured, and the injection timing was corrected.

  According to the present invention, the sheet passage detection sensor is used to measure the elongation of the chain and correct the injection timing. Therefore, there is an effect that the injection timing can be corrected without providing a new sensor. .

It is a figure which shows the printing machine concerning this invention. FIG. 2 is a detailed view of a conveyance unit, a varnish coating unit, and a paper discharge unit in FIG. 1. It is a figure explaining elongation of a chain. It is the elements on larger scale of a chain. It is a control circuit diagram of a spray device. It is an operation | movement timing diagram of a spray apparatus.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments for carrying out the invention will be described with reference to the drawings.

  In FIG. 1, the printing unit 3 has a four-print unit configuration so that four-color printing can be performed at once, and prints with black, cyan, magenta, and yellow ink from the upstream in the normal transport direction. 7 is a plate cylinder, 8 is a rubber cylinder, and 9 is an impression cylinder.

  The conveyance unit 4 receives a sheet from the last impression cylinder 9 of the printing unit 3 and delivers it to the impression cylinder 5a of the varnish coating device 5. The conveyance unit front sprocket 4a driven by the impression cylinder 9 and the conveyance unit rear sprocket. A chain 4c is wound around 4b. 2, the chain 4c is configured to pass through the tension applying portion 11 so that the chain 4c does not stretch and sag. The tension applying portion 11 includes the tensioner 11a and the tension applying portion 11a. Consists of rollers 11b and 11b located on both sides, the tensioner 11a can move upward, and the urging force applied to the chain 4c can be adjusted.

  The paper discharge unit 6 receives a sheet from the pressure drum 5a of the varnish coating apparatus 5 and conveys the sheet onto the paper discharge pile. The paper discharge unit front sprocket 6a driven by the pressure drum 5a and the paper discharge A chain 6c is wound around the rear sprocket 6b. Prevention of sagging due to extension of the chain 6c is performed by urging the rear sprocket 6b in the horizontal direction to the downstream side, and this configuration is already well known.

  Chain grippers 30 are suspended at a plurality of locations on the chain 4c and the chain 6c, respectively. The suspension interval of the chain gripper 30 is a distance traveled by the chains 4c and 6c when the impression cylinder 9 makes one rotation. In the example of the printing press 1, the suspension is suspended at seven locations.

  Also, a sheet passage detection sensor 40 is provided below the chain 6c, and detects the presence or absence of sheets after the chain gripper 30 has passed, and the detection signal is input to a microcomputer (CPU) 61 described later. When it is determined that there is no sheet, the microcomputer (CPU) 61 sends a signal to a main controller (not shown) of the printing machine 1 to perform control such as stopping the operation of the printing machine 1. Reference numeral 50 denotes a spray device, which sprays spray powder uniformly on the surface of a printed sheet.

  The impression cylinder 9 is axially supported via a bearing between the frames of the printing press 1 by an impression cylinder shaft (not shown). Similarly, the conveyance unit front sprocket 4a for driving the chain 4c is pivotally supported between the frames of the printing press 1 via a bearing by a chain drive shaft (not shown). A driving force of a driving motor (not shown) of the printing press 1 is transmitted to a gear fastened to the chain drive shaft by a gear fastened to the impression cylinder 9, and the transport unit front sprocket 4a is rotated by the driving force. Since the chain 4 c is driven and the chain gripper 30 is suspended on the chain 4 c, the sheet gripped by the chain gripper 30 is conveyed to the downstream side of the printing press 1. A similar configuration can also be seen between the impression cylinder 5a of the varnish coating device 5 and the front sprocket 6a of the paper discharge unit 6. A rotary encoder 20 is attached to the impression cylinder shaft of the impression cylinder 9, and outputs an origin pulse GP and a rotation pulse RP according to the rotation of the impression cylinder 9 (see FIG. 5). When the impression cylinder 9 makes one rotation, one origin pulse GP is output, and a plurality of (N) pulses are output as the rotation pulse RP. The generation timing of the origin pulse GP is adjusted so that the rotary encoder 20 is attached to the impression cylinder shaft so that the sheet becomes a position where the sheet is changed from the impression cylinder 9 to the chain gripper 30 of the transport unit 4.

  The chain gripper 30 includes a claw and a claw base (not shown), and is fixed to different gripper shafts. Therefore, one chain gripper 30 has two gripper shafts.

  FIG. 3 is a conceptual diagram for explaining chain elongation and timing deviation. L is a conceptual distance from the position where the sprocket 4a in front of the transport unit receives the sheet from the impression cylinder 9 to the position of the spray device 50. Represents.

  FIG. 4 is a partially enlarged view of the chains 4c and 6c. The minimum unit of the chains 4c and 6c is constituted by the outer link and the inner link. Q represents the pitch when the chains 4c and 6c are still new and there is no elongation.

  FIG. 5 is a control circuit for controlling the spray device 50, which is arranged near an operation panel (not shown) of the paper discharge unit 6, and FIG. 6 is a timing chart thereof, in which no elongation occurs in the chains 4c and 6c. Is the case. The microcomputer 61 receives an origin pulse GP and a rotation pulse RP that are output as the rotary encoder 20 rotates, and also receives a signal JS from the sheet passage detection sensor 40. In addition, a signal indicating whether or not the printing press 1 is idling is also input to the microcomputer (CPU) 61 from a main controller (not shown) of the printing press 1. The microcomputer (CPU) 61 outputs an injection command ST to the spray controller 51 based on these signals, and the spray controller 51 drives the spray device 50 by the signals to inject spray powder. If the printing press 1 is idling, the sheet passage detection sensor 40 outputs a signal JS composed of two pulses for detecting two gripper shafts (not shown) of the chain 6c while the impression cylinder 9 rotates once. Occurs once. Since the two gripper shafts are separated by a small gap in the front and rear, two pulses are generated continuously. Further, during the normal printing operation, the ejection command ST is output once during that time. Reference numeral 62 denotes a storage element built in the microcomputer (CPU) 61. In the present invention, 62 is a data table in which the number of pulses for correcting the injection timing is stored. The number of pulses can be obtained by calculation or experiment in the manufacturing stage of the printing press 1.

  The operation of the spray device of the printing press configured as described above will be described. If the printing press 1 has been used for many years, the chains 4c and 6c will extend slightly. In this state, the chains 4c and 6c are slackened. Therefore, the tension is applied to the chain 4c by the tension applying unit 11 and the chain 6c is applied with the tension by urging the sprocket 6b downstream of the paper discharge unit in the horizontal direction. It prevents it. However, since the pitch Q of the chains 4c and 6c is Q + α, the number of links as the minimum unit constituting the chain within the distance L shown in FIG. 4c and 6c will be less than the case where new elongation has not yet occurred. Since the chain gripper 30 is fixed to a specific link constituting the chains 4c and 6c, when the chains 4c and 6c are extended, the sheets held in the chain gripper 30 are not attached to the chains 4c and 6c. In the control method of the printing press 1 in which the position of the spray device 50 is reached earlier than in the case where the spray device 50 is not stretched and the rotation pulse RP of the rotary encoder 20 is counted and the spray timing of the spray device 50 is controlled. Deviation occurs in timing. Therefore, in order to eliminate the deviation of the injection timing and output the injection command ST at an accurate timing, it is necessary to measure the elongation of the chains 4c and 6c. However, in the present invention, a new sensor or the like is used to measure the elongation. The existing sheet passage detection sensor 40 is used without providing any.

  5 and 6, when the printing press 1 is idling, the microcomputer (CPU) 61 executes a program for measuring the elongation of the chains 4c and 6c based on the signal JS from the sheet passage detection sensor 40. . The microcomputer (CPU) 61 detects the two gripper shafts by the sheet passage detection sensor 40 after the origin pulse GP is output as an initial value when the chains 4c and 6c are not stretched. The number R (N> R) of the rotation pulses RP up to is stored. Similarly, the number M (N> M) of rotation pulses RP up to the injection timing is stored. When the number of rotation pulses RP detected by the sheet passage detection sensor 40 when the chains 4c and 6c extend and the pitch Q becomes Q + α is Rα, the difference (R−Rα) is the chain 4c, The gripper shaft is detected by the sheet passage detection sensor 40 earlier than when no elongation occurs in 6c. Based on this pulse number (R−Rα), the number of pulses for adjusting the injection timing of the spray device 50 stored in advance in the microcomputer (CPU) 61 is called from the data table 62 to correct the output timing of the injection command ST. The number of pulses to be obtained is obtained. That is, if the number of pulses in the data table 62 corresponding to (R−Rα) is B, the injection timing may be set at the (MB) pulse. When the printing press 1 moves to the normal printing operation from idling, the signal is transmitted to the microcomputer (CPU) 61, and the injection command ST from the microcomputer (CPU) 61 receives the origin pulse GP, and then receives the rotation pulse RP. It is controlled to output to the spray controller 51 at the (MB) pulse.

  Thus, since the spray timing of spray powder can be kept appropriate while measuring the elongation of the chain, it becomes possible to reliably spray the spray powder on the sheet.

  The printing press 1 according to the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made within the scope described in the claims. For example, although the above embodiment has been described as the printing machine 1 including the varnish coating apparatus 5, the present invention can be applied to a printing machine that does not include the varnish coating apparatus 5.

  The present invention is useful in a printing press.

DESCRIPTION OF SYMBOLS 1 Printing machine 2 Paper feed part 3 Printing unit 4 Conveying part 4a Sprocket front 4a Conveying part Sprocket 4c Chain 5 Varnish coating device 6 Paper discharge part 6a Sprocket before paper discharge part 6b Paper discharging part sprocket 6c Chain 7 Plate cylinder 8 Rubber cylinder 9 Pressure cylinder 9a Gear 11 Tension applying part 11a Tensioner 11b Roller 20 Rotary encoder 30 Chain gripper 40 Sheet paper passage detection sensor 50 Spray device 51 Spray controller 61 Microcomputer (CPU)
62 Data table

Claims (1)

  In a printing press having a paper discharge unit incorporating a chain for transporting a sheet of paper, an extension amount of the chain is measured by a sheet passage detection sensor provided in the paper discharge unit, and provided in the paper discharge unit. A printing machine characterized by correcting the ejection timing of the spray device.

Images