JP2005169634A - Printing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing machine capable of precisely performing recording of an image by preventing a driver from being damaged and generating heat although it has a simple constitution. <P>SOLUTION: As a motor 58 for making a printing plate, the motor having an induced electric voltage constant K is selected so that when a pressure resistance of the driver 93 to a reverse electromotive voltage is V, the value of a reverse electromotive force Vs which is a product of a following number of rotation N with an induced electric voltage constant K of the motor 58 for making the printing plate, becomes to be sufficiently smaller than V. In addition, when the motor 58 for making the printing plate is followingly rotated, by opening an electromagnetic switch 92 and cutting a connection of the motor 58 for making the printing plate with the driver 93 through an electric power supplying line 95, the reverse electromotive force is prevented from being loaded on the driver 93. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a printing machine that records an image on a printing plate mounted on the outer peripheral portion of a plate cylinder and performs printing by supplying ink to the printing plate.

  In a conventional general printing press, a printing plate is prepared by bringing a film on which a black and white binary image is recorded and the printing plate into close contact with each other in the plate making process and then exposing the printing plate to the printing press. The printing process was executed.

  On the other hand, in recent years, a printing machine generally called a digital printing machine that can execute such a plate making process and a printing process with one apparatus has been proposed. In this digital printing machine, a “computer to plate” system is employed in which a printing plate is directly scanned and exposed to form a image on a printing plate by a laser beam or the like modulated based on an image signal.

  Here, in a general printing press, the plate cylinder is connected to a plate cylinder gear arranged concentrically with the plate cylinder, a blanket cylinder gear arranged concentrically with the blanket cylinder, or the like. Are connected to a printing motor such as an inverter motor, and are rotated by driving the printing motor during printing.

  On the other hand, in a printing machine that performs both plate-making and printing, it is necessary to rotate the plate cylinder with the printing plate held on its outer periphery with high accuracy when recording an image on the printing plate by an image recording device. There is. At this time, when the drive system at the time of printing in the printing press is used as described above, the inverter motor used in such a drive system can rotate the plate cylinder at a high speed, but there are many variations in the rotation accuracy. Therefore, there arises a problem that it is difficult to record an image with high accuracy.

For this reason, in such a printing machine, a configuration is adopted in which an image is recorded with high accuracy by rotating a plate cylinder by a plate-making motor such as a servo motor different from the printing motor during image recording. Yes. More specifically, as described in Patent Document 1, a clutch is provided between the plate cylinder gear and the plate cylinder, and the drive transmission relationship between the plate cylinder and the drive system of the printing press is released during plate making. Thereafter, an image is recorded while rotating the plate cylinder using a plate-making motor different from the motor used in the drive system of the printing press.
JP 2000-280439 A

  In the printing machine described in Patent Document 1, in order to prevent the driven rotation of the plate-making motor at the time of printing, in addition to the clutch between the plate cylinder gear and the plate cylinder, between the plate cylinder and the plate-making motor. It is necessary to provide a clutch. Thus, when a clutch is further provided between the plate cylinder and the plate-making motor, the apparatus configuration becomes complicated. Further, the image recording accuracy may be deteriorated due to the phase shift of the clutch during plate making.

  For this reason, when separate motors are used for image recording and plate making, the clutch between the plate cylinder and the plate making motor described above is omitted, and the plate making motor is accompanied by the rotation of the plate cylinder during printing. It is also possible to adopt a configuration in which the driven rotation is performed. However, in this case, the counter electromotive force generated when the plate-making motor is driven to rotate not only damages the driver that controls the rotation of the motor, but also the plate-making motor generates heat and creates a danger. There is.

  The present invention has been made to solve the above problems, and provides a printing machine capable of accurately recording an image while preventing damage and heat generation of the driver while having a simple configuration. For the purpose.

  The invention according to claim 1 is a printing machine that performs printing by recording an image on a printing plate mounted on an outer peripheral portion of a plate cylinder and then supplying ink to the printing plate to perform printing. A plate cylinder, an image recording apparatus for recording an image on a printing plate mounted on the outer periphery of the plate cylinder, and the image recording apparatus connected to the plate cylinder when the image is recorded by the image recording apparatus. A plate-making motor that rotates the plate cylinder, and a printing motor that is coupled to the plate cylinder via a gear and rotates the plate cylinder during printing, and is connected to the plate-making motor via a power supply line and a signal line. And a driver for controlling the rotation of the plate-making motor, wherein the pressure resistance of the driver against the counter electromotive voltage generated by the driven rotation of the plate-making motor during printing is V, and the driven rotation speed of the plate-making motor during printing is N, motor for plate making When the induced voltage constant was K, characterized in that the product of N and K is sufficiently smaller than V.

  According to a second aspect of the present invention, in the first aspect of the present invention, the plate-making motor and the driver are arranged in a power supply line that connects the plate-making motor and the driver. A switch for disconnecting the connection by the power supply line is further provided.

  The invention according to claim 3 is a printing machine that performs printing by recording an image on a printing plate mounted on the outer peripheral portion of the plate cylinder and then supplying ink to the printing plate to perform printing. A plate cylinder, an image recording apparatus for recording an image on a printing plate mounted on the outer periphery of the plate cylinder, and the image recording apparatus connected to the plate cylinder when the image is recorded by the image recording apparatus. A plate-making motor that rotates the plate cylinder, and a printing motor that is coupled to the plate cylinder via a gear and rotates the plate cylinder during printing, and is connected to the plate-making motor via a power supply line and a signal line. A driver for controlling the rotation of the plate-making motor, and a power supply line connecting the plate-making motor and the driver, and connecting the plate-making motor and the driver by the power supply line during printing. With a switch to cut It is characterized in.

  According to a fourth aspect of the invention, there is provided a connection release mechanism for releasing the connection between the printing motor and the plate cylinder during image recording in the first to third aspects of the invention.

  According to the invention described in claim 5, in the invention described in any one of claims 1 to 4, the brake function of the plate-making motor by the driver is released during printing.

  According to the invention described in claim 1, since the plate cylinder is rotated by using a plate-making motor different from the printing motor at the time of image recording, the image recording can be executed with high accuracy. Since the clutch for preventing the driven rotation of the plate-making motor during printing is not used, the apparatus configuration is simplified, and the deterioration of the image recording accuracy due to the phase shift of the clutch can be prevented. And since the magnitude of the back electromotive force generated by the driven rotation of the plate making motor can be made sufficiently smaller than the withstand voltage of the plate making motor driver, damage to the driver can be prevented, and heat generation of the plate making motor can be prevented. Heat generation can be minimized.

  According to the second aspect of the present invention, it is possible to reliably prevent the counter electromotive voltage generated by the driven rotation of the plate making motor from being applied to the driver of the plate making motor.

  According to the invention of claim 3, since the plate cylinder is rotated by using a plate-making motor different from the printing motor at the time of image recording, the image recording can be executed with high accuracy, and Since the clutch for preventing the driven rotation of the plate-making motor during printing is not used, the apparatus configuration is simplified, and the deterioration of the image recording accuracy due to the phase shift of the clutch can be prevented. Since it is possible to reliably prevent the counter electromotive voltage generated by the driven rotation of the plate-making motor from being applied to the driver of the plate-making motor, it is possible to prevent damage to the driver.

  According to the fourth aspect of the present invention, it is possible to prevent other components of the printing machine such as an ink roller from being driven during plate making.

  According to the fifth aspect of the invention, since the brake function of the plate-making motor is released during printing, the plate cylinder can be smoothly rotated.

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

  First, the overall configuration of a printing machine to which the present invention is applied will be described. FIG. 1 is a schematic view of a printing machine to which the present invention is applied.

  The printing machine records an image on a printing plate on which images held on the first and second plate cylinders 11 and 12 are not recorded, and then makes the ink supplied to the printing plate first, Printing on four colors is performed by transferring to the printing paper held by the first and second impression cylinders 15 and 16 via the second blanket cylinders 13 and 14.

  The printing press includes a first plate cylinder 11, a second plate cylinder 12, a first blanket cylinder 13 provided in contact with the first plate cylinder 11, and a second plate cylinder 12. A second blanket cylinder 14 provided so as to be able to contact, a first pressure cylinder 15 provided so as to be able to contact the first blanket cylinder 13, and a contact with the second blanket cylinder 14 The second impression cylinder 16 provided in a possible manner, the feed cylinder 17 for passing the printing paper supplied from the paper feeding unit 31 to the first impression cylinder 15, and the print received from the first impression cylinder 15. A transfer cylinder 18 for passing the sheet to the second impression cylinder 16 and a chain 23 for discharging the printing sheet received from the second impression cylinder 16 to the sheet discharge unit 32 are wound around the sprocket 22. In order to take an image printed on the paper discharge cylinder 19 and the printing paper and to measure the density of the detection patch Having an imaging unit 60.

  The first plate cylinder 11 and the second plate cylinder 12 are so-called double cylinders that hold printing plates for two different colors on the outer periphery thereof. The first blanket cylinder 13 and the second blanket cylinder 14 have the same diameter as the first plate cylinder 11 and the second plate cylinder 12, and each has a blanket surface on which images of two colors can be transferred. .

  A first impression cylinder 15 and a second impression cylinder 16 provided so as to be able to contact the first blanket cylinder 13 and the second blanket cylinder 14, respectively, 1. It has a diameter that is ½ of the diameter of the second blanket cylinder 13, 14. The first and second impression cylinders 15 and 16 have grippers (not shown) for holding and conveying the leading edge of the printing paper.

  A sheet feeding cylinder 17 disposed adjacent to the impression cylinder 15 has the same diameter as the first and second impression cylinders 15 and 16. The sheet feeding cylinder 17 holds and conveys the leading end portion of the printing paper supplied one by one from the sheet feeding unit 31 with a gripper (not shown) for each rotation of the sheet feeding cylinder 17. The leading end of the printing paper held by the gripper is held by the gripper of the first pressure drum 15 when the printing paper is transferred from the paper feeding drum 17 to the first pressure drum 15.

  A transfer cylinder 18 disposed between the first impression cylinder 15 and the second impression cylinder 16 includes first and second plate cylinders 11 and 12 and first and second blanket cylinders 13 and 14. It has the same diameter as the diameter. The transfer cylinder 18 holds and conveys the leading end of the printing paper received from the first impression cylinder 15 by a gripper (not shown), and delivers the leading end of the printing paper to the gripper of the second impression cylinder 16.

  A paper discharge cylinder 19 disposed adjacent to the second impression cylinder 16 has the same diameter as that of the first and second plate cylinders 11 and 12 and the first and second blanket cylinders 13 and 14. Have. The paper discharge cylinder 19 has a structure in which a pair of chains 23 are wound around both ends thereof, and a gripper (not shown) is disposed on a connection member (not shown) that connects the pair of chains 23. The leading end portion of the printing paper held by the gripper of the second impression cylinder 16 is held by any of the grippers of the discharge cylinder 19 when the printing paper is transferred from the second impression cylinder 16 to the discharge cylinder 19. The The printing paper is discharged onto the paper discharge unit 32 as the chain 23 moves.

  As will be described later, the gear attached to the paper feed cylinder 17 is connected to a gear 26 disposed concentrically with the driven pulley 25. A belt 29 is wound between a driving pulley 28 and a driven pulley 25 that are rotated by driving the printing motor 27. For this reason, the paper feed cylinder 17 is rotated by driving the drive printing motor 27. On the other hand, the first and second plate cylinders 11 and 12, the first and second blanket cylinders 13 and 14, the first and second impression cylinders 15 and 16, the paper feed cylinder 17, the transfer cylinder 18 and the paper discharge cylinder As will be described later, 19 are connected to each other by gears attached to the end portions thereof. For this reason, by driving the drive printing motor 27, the paper feed cylinder 17, the first and second impression cylinders 15, 16, the paper discharge cylinder 19, the first and second blanket cylinders 13, 14, and the first The second plate cylinders 11 and 12 and the transfer cylinder 18 rotate in synchronization with each other.

  Around the first plate cylinder 11, an ink supply device 20a for supplying, for example, black (K) ink to the printing plate, and an ink supply device for supplying, for example, cyan (C) ink to the printing plate 20b and dampening water supply devices 21a and 21b for supplying dampening water to the printing plate are arranged. Further, around the second plate cylinder 12, an ink supply device 20c for supplying, for example, magenta (M) ink to the printing plate, and an ink for supplying, for example, yellow (Y) ink to the printing plate. A supply device 20d and dampening water supply devices 21c and 21d for supplying dampening water to the printing plate are arranged.

  Further, around the first plate cylinder 11 or the second plate cylinder 12, a plate feeding section 33 for supplying a printing plate to the outer peripheral portion of the first plate cylinder 11, and a second plate cylinder, respectively. A plate supply unit 34 for supplying a printing plate to the outer periphery of the first plate cylinder, an image recording device 35 for recording an image on the printing plate mounted on the outer periphery of the first plate cylinder 11, and a second plate cylinder An image recording device 36 for recording an image on a printing plate mounted on the outer peripheral portion of 12 is disposed.

  In the printing machine having the above-described configuration, the printing plate drawn from the supply cassette 41 in the plate supply unit 33 is cut into a predetermined size by the cutter 42. Then, the leading end portion of the cut sheet-like printing plate is guided by a guide roller and a guide member (not shown), and is held by a holding claw of the first plate cylinder 11. Then, the first plate cylinder 11 is rotated at a low speed by driving a motor (not shown), the printing plate is wound around the outer peripheral portion of the first plate cylinder 11, and the rear end portion of the printing plate is held by the other holding nail. . In this state, while rotating the first plate cylinder 11 at a low speed, the image recording device 35 irradiates the surface of the printing plate held on the outer periphery of the first plate cylinder 11 with a modulated laser beam, Record.

  Similarly, the printing plate drawn out from the supply cassette 43 in the plate supply unit 34 is cut into a predetermined size by the cutter 44. Then, the leading end portion of the cut sheet-like printing plate is guided by a guide roller and a guide member (not shown), and is held by a holding claw of the second plate cylinder 12. Then, the second plate cylinder 12 is rotated at a low speed by driving a motor (not shown), the printing plate is wound around the outer periphery of the second plate cylinder 12, and the rear end portion of the printing plate is held by the other holding nail. . In this state, while rotating the second plate cylinder 12 at a low speed, the image recording device 36 irradiates the surface of the printing plate held on the outer periphery of the second plate cylinder 12 with a modulated laser beam, Record.

  A printing plate for printing with black ink and a printing plate for printing with cyan ink are mounted on the outer periphery of the first plate cylinder 11. These two printing plates are arranged at positions where they are evenly distributed (that is, separated from each other by 180 degrees), and the image recording device 35 records an image on these printing plates. Similarly, a printing plate for printing with magenta ink and a printing plate for printing with yellow ink are mounted on the outer periphery of the second plate cylinder 12. These two printing plates are also arranged at positions where they are equally distributed, and the image recording device 36 records an image on these printing plates, and the plate making process is completed.

  When the plate making process is completed, a printing process is performed in which printing is performed on printing paper using the printing plates on the first and second plate cylinders 11 and 12. This printing process is performed as follows.

  That is, first, each fountain solution supply device 21 and each ink supply device 20 are brought into contact only with the corresponding printing plates among the printing plates held on the first and second plate cylinders 11 and 12. Accordingly, the dampening water and the ink are supplied to each printing plate from the corresponding dampening water supply device 21 and the corresponding ink supply device 20. The ink supplied to the printing plate is transferred to corresponding areas of the first and second blanket cylinders 13 and 14.

  Then, the printing paper is supplied to the paper feed cylinder 17. This printing paper is delivered from the paper feed cylinder 17 to the first impression cylinder 15. When the first impression cylinder 15 that has received the printing paper continues to rotate, the first impression cylinder 15 has a diameter that is ½ that of the first plate cylinder 11 and the first blanket cylinder 13. On the printing paper held on the outer peripheral portion of one impression cylinder 15, black ink is transferred in the first rotation, and cyan ink is transferred in the second rotation.

  If the first impression cylinder 15 rotates twice, the printing paper is transferred from the first impression cylinder 15 via the transfer cylinder 18 to the second impression cylinder. When the second impression cylinder 16 that has received the printing paper continues to rotate, the second impression cylinder 16 has a diameter that is ½ that of the second plate cylinder 12 and the second blanket cylinder 14. On the printing paper held on the outer periphery of the second impression cylinder 16, magenta ink is transferred in the first rotation, and yellow ink is transferred in the second rotation.

  In this way, the leading end portion of the printing paper on which the printing of four colors has been completed is transferred from the second impression cylinder 16 to the discharge cylinder 19. Then, the printing paper on which the printing of the four colors has been completed is conveyed toward the paper discharge unit 28 by the drive of the pair of chains 23 and is discharged.

  When the printing process is completed, the printing plate used for printing is discharged. Then, the first and second blanket cylinders 13 and 14 are cleaned by a blanket cylinder cleaning device (not shown), and the printing process is completed.

  Next, the structure of the characteristic part of this invention is demonstrated. FIG. 2 is a schematic side view showing the connection relationship of the first plate cylinder 11, the first blanket cylinder 13, the first impression cylinder 15, and the paper feed cylinder 17. In FIG. 2, the first plate cylinder 11, the first blanket cylinder 13, the first impression cylinder 15 and the sheet feeding cylinder 17 are developed in a plane.

  A plate cylinder gear 51 is disposed on the side of the first plate cylinder 11. Similarly, a blanket cylinder gear 52 that meshes with the plate cylinder gear 51 is disposed on the side of the first blanket cylinder 13. A pressure drum gear 53 that meshes with the blanket drum gear 52 is disposed on the side of the pressure drum 15. Further, a paper feed cylinder gear 54 that meshes with the impression cylinder gear 53 is disposed on the side of the paper feed cylinder 17.

  The first plate cylinder 11, the first blanket cylinder 13, the first impression cylinder 15, and the paper feed cylinder 17 are supported at both ends by a pair of side plates 50. A gear 55 is disposed on the side of the paper feed cylinder 17 opposite to the paper feed cylinder gear 54. The gear 55 is connected to the gear 26 arranged concentrically with the driven pulley 25 described above. As shown in FIG. 1, the driving pulley 28 and the driven pulley 25 are rotated by driving the printing motor 27. A belt 29 is wound around the belt 29. For this reason, the paper feed cylinder 17 is rotated by driving the printing motor 27. The rotational driving force is transmitted through the plate cylinder gear 51, the blanket cylinder gear 52, the impression cylinder gear 53, and the sheet feeding cylinder gear 54, and the first plate cylinder 11, the first blanket cylinder 13, the impression cylinder. 15 and the paper feed cylinder 17 rotate in synchronization.

  Between the first plate cylinder 11 and the plate cylinder gear 51, there is a clutch 56 for separating and independently rotating the first plate cylinder 11 from the drive system of other cylinders when performing the plate making operation. It is arranged. A rotary encoder 57 is disposed at the end of the first plate cylinder 11 opposite to the clutch 56, and the first plate cylinder 11 rotates at the side of the first plate cylinder 11 during image recording. For this purpose, a plate-making motor 58 is provided. Instead of using the clutch 56 for independently rotating the first plate cylinder 11 during plate making, a cylinder removing mechanism for temporarily releasing the meshing relationship between the plate cylinder gear 51 and the blanket cylinder gear 52 is used. May be.

  FIG. 3 is an enlarged view showing one end portion of the first plate cylinder 11.

  The support shaft 81 of the first plate cylinder 11 is supported by a bearing 82 disposed on the side plate 50, and a rotary encoder 57 is disposed at the tip of the support shaft 81. Further, a synchronous pulley 83 is attached to the support shaft 81. On the other hand, a plate-making motor 58 for rotating the first plate cylinder 11 during image recording is fixed to the side plate 50 via a support member 84. A synchronous pulley 86 is attached to the rotating shaft 85 of the plate-making motor 58. The synchronous pulley 83 attached to the support shaft 81 of the first plate cylinder 11 and the synchronous pulley 86 attached to the rotating shaft 85 of the plate-making motor 58 are connected via a synchronous belt 87. For this reason, the first plate cylinder 11 is configured to rotate by driving the plate-making motor 58.

  In the above description, the drive system for the first plate cylinder 11, the first blanket cylinder 13, the first impression cylinder 15 and the paper feed cylinder 17 has been described. The blanket cylinder 14, the second impression cylinder 16, and the paper discharge cylinder 19 have the same configuration as described above except that the plate-making motor 58 is driven via the transfer cylinder 18. The second plate cylinder 12 is rotationally driven by a plate-making motor 58 different from the plate-making motor 58 shown in FIGS. 2 and 3 during plate making.

  FIG. 4 is a block diagram showing the main electrical configuration of the drive mechanism during plate making of the first and second plate cylinders 11 and 12 in this printing machine.

  The printing press includes a control unit 91 for controlling the entire apparatus. The control unit 91 is connected to the driver 93. The driver 93 includes a CPU and an ASIS (specific application IC) inside and controls rotation of the plate-making motor 58. The driver 93 is connected to a plate-making motor 58 through a signal line 94. The driver 93 is connected to a power supply line 95 connected to a power source, and is connected to the plate-making motor 58 via the power supply line 95. An electromagnetic switch 92 whose opening / closing operation is controlled by the control unit 91 is disposed at a position between the driver 93 and the plate-making motor 58 in the power supply line 95.

  As the plate-making motor 58, a servo motor is used. As shown in FIGS. 2 and 3, the plate-making motor 58 is connected to the first plate cylinder 11. Therefore, when the first plate cylinder 11 is rotated by driving the printing motor 27 shown in FIG. 1 during printing, the plate-making motor 58 is also driven to rotate. This also applies to the second plate cylinder 12.

  Thus, when the plate-making motor 58 is driven to rotate, a counter-electromotive force is generated from the plate-making motor 58, and this counter-electromotive force is applied to the driver 93 via the power supply line 95. When such a back electromotive force is applied to the driver 93, the driver 93 is damaged. In addition, when the plate-making motor 58 is driven to rotate, depending on the rating of the plate-making motor 58, there is a problem that the plate-making motor 58 itself generates excessive heat. For this reason, in this printing machine, the rating of the plate-making motor 58 is specially selected and the electromagnetic switch 92 is used.

  That is, the counter electromotive force Vs generated from the plate-making motor 58 when the plate-making motor 58 is driven to rotate is N as the driven rotational speed of the plate-making motor 58 during printing, and K is the induced voltage constant of the plate-making motor 58. Is represented by the following equation.

Vs = N * K
For this reason, as the plate-making motor 58, a motor having an induced voltage constant K such that the value of the counter electromotive force Vs is sufficiently smaller than the withstand voltage of the driver 93 against the counter electromotive voltage is selected. When the plate-making motor 58 is driven to rotate, the electromagnetic switch 92 is opened by the control of the control unit 91 so that the connection between the plate-making motor 58 and the driver 93 by the power supply line 95 is disconnected.

  More specifically, a plate-making motor 58 having an induced voltage constant K of about 22.5 mV / min is used. If the driven rotational speed N at this time is 133 revolutions per minute, for example, the counter electromotive force Vs obtained by multiplying these is 3.4V. Here, when the withstand voltage V of the driver 93 is about 500 V, the value of the back electromotive force Vs can be made sufficiently smaller (1% or less) than the withstand voltage V of the driver 93.

  In this specification, “making the value of the back electromotive force Vs sufficiently smaller than the withstand voltage V of the driver 93” means that the value of the back electromotive force Vs is 10% or less, preferably 5% or less of the withstand voltage V of the driver 93. More preferably, it means 1% or less.

  Further, when the plate-making motor 58 is driven to rotate, the brake function when the driver 93 is servo-off is canceled to set “free run” and the rotation angle origin confirmation function by the rotary encoder 57 is turned off. Then, in response to a signal from the control unit 91, the electromagnetic switch 92 is opened to cut off the connection between the plate-making motor 58 and the driver 93 by the power supply line 95.

  In this way, when the plate-making motor 58 is driven to rotate, the electromagnetic switch 92 is opened to disconnect the plate-making motor 58 and the driver 93 from the power supply line 95, thereby causing the driver 93 to counter electromotive force. Can be completely prevented from being applied.

  When the electromagnetic switch 92 does not perform the opening operation by making the product of the driven rotational speed N of the plate-making motor 58 and the induced voltage constant K of the plate-making motor 58 sufficiently smaller than the withstand voltage V of the driver 93 Even when such an error occurs, it is possible to prevent the driver from being damaged. In addition, it is possible to prevent the problem that the plate-making motor 58 generates heat and generates danger.

  In the above-described embodiment, the electromagnetic switch 92 is opened during the driven rotation of the plate making motor 58 to completely prevent the back electromotive force from being applied to the driver 93, and the driven rotation of the plate making motor 58 is driven. A double safety measure has been implemented in which the product of the number N and the induced voltage constant K of the plate-making motor 58 is made sufficiently smaller than the withstand voltage V of the driver 93, but only one of these is adopted. You may do it.

1 is a schematic diagram of a printing machine to which the present invention is applied. 2 is a schematic side view showing a connection relationship among a first plate cylinder 11, a first blanket cylinder 13, a first impression cylinder 15 and a sheet feeding cylinder 17. FIG. 3 is an enlarged view showing one end portion of the first plate cylinder 11. FIG. It is a block diagram which shows the main electric structures of the drive mechanism at the time of plate making of the 1st and 2nd plate cylinders 11 and 12 in this printing machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 1st printing cylinder 12 2nd printing cylinder 13 1st blanket cylinder 14 2nd blanket cylinder 15 1st impression cylinder 16 2nd impression cylinder 17 Paper feed cylinder 18 Transfer cylinder 19 Paper discharge cylinder 20 Ink supply Device 21 Dampening water supply device 22 Sprocket 23 Chain 27 Printing motor 31 Paper feed portion 32 Paper discharge portion 33 Plate feed portion 34 Plate feed portion 35 Image recording device 36 Image recording device 51 Plate cylinder gear 52 Blanket cylinder gear 53 Pressure drum Gear 54 Feed cylinder gear 55 Gear 56 Clutch 58 Plate making motor 81 Support shaft 83 Synchronous pulley 85 Rotating shaft 86 Synchronous pulley 87 Synchronous belt 91 Control unit 92 Electromagnetic switch 93 Driver 94 Signal line 95 Power supply line

Claims (5)

A printing machine that performs printing by recording an image on a printing plate mounted on the outer periphery of a plate cylinder and supplying ink to the printing plate,
A plate cylinder holding the printing plate on its outer periphery,
An image recording apparatus for recording an image on a printing plate mounted on the outer periphery of the plate cylinder;
A plate-making motor connected to the plate cylinder and rotating the plate cylinder when an image is recorded by the image recording apparatus;
A printing motor connected to the plate cylinder via a gear and rotating the plate cylinder during printing;
A driver for controlling the rotation of the plate-making motor, connected to the plate-making motor through a power supply line and a signal line;
When the pressure resistance of the driver with respect to the counter electromotive voltage generated by the driven rotation of the plate-making motor during printing is V, the driven rotation speed of the plate-making motor during printing is N, and the induced voltage constant of the plate-making motor is K A printing machine characterized in that the product of N and K is sufficiently smaller than V. The printing press according to claim 1, wherein
A printing machine further comprising a switch disposed in a power supply line connecting the plate-making motor and the driver, and disconnecting the connection of the plate-making motor and the driver by the power supply line during printing. A printing machine that performs printing by recording an image on a printing plate mounted on the outer periphery of a plate cylinder and supplying ink to the printing plate,
A plate cylinder holding the printing plate on its outer periphery,
An image recording apparatus for recording an image on a printing plate mounted on the outer periphery of the plate cylinder;
A plate-making motor connected to the plate cylinder and rotating the plate cylinder when an image is recorded by the image recording apparatus;
A printing motor connected to the plate cylinder via a gear and rotating the plate cylinder during printing;
A driver for controlling rotation of the plate-making motor, connected to the plate-making motor via a power supply line and a signal line;
A switch disposed in a power supply line connecting the plate-making motor and the driver, and disconnecting the connection of the plate-making motor and the driver by the power supply line during printing;
A printing machine comprising: The printing press according to any one of claims 1 to 3,
A printing machine comprising a connection release mechanism for releasing connection between the printing motor and the plate cylinder during image recording. The printing press according to any one of claims 1 to 4,
A printing machine that releases a brake function of the plate-making motor by the driver during printing.

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