JP4664667B2 - Printing device - Google Patents

Description

  The present invention relates to a printing apparatus such as a stencil printing apparatus having a plate cylinder and a plate discharging apparatus that collects a master wound around the plate cylinder as the plate cylinder rotates.

  Conventionally, in such a printing apparatus, as described in, for example, [Patent Document 1] and [Patent Document 2], a plate discharging apparatus that collects and discharges a master wound around a plate cylinder together with the rotation of the plate cylinder has been used. It has been. In general, such a plate removing apparatus takes into account the variation in the recovery speed of the master during the recovery of the master, and generally makes the recovery speed of the master faster than the rotational speed of the plate cylinder for the purpose of preventing the meandering of the master.

  The master has an ink adhering part and an unadhered part, and only the ink adhering part is attached to the peripheral surface of the plate cylinder, so the ink adhering part is wrapped around the plate cylinder Then, the master is recovered with a predetermined tension between the plate discharging device and the plate cylinder. The unattached portion of the ink is formed at the front end portion and the rear end portion of the master. The speed difference between the plate removal apparatus and the plate cylinder is eliminated by causing a slip with the master on the plate removal apparatus side.

JP 2004-148514 A Japanese Patent Laid-Open No. 9-290553

  However, when recovery of the master progresses and the ink adhering part is peeled off from the plate cylinder, the master is released from tension at a stretch and becomes free. The defect of the conveyance failure of an edge part arises. Specifically, there are problems such as the remaining plate removal at the rear end, or the master being caught or wound due to the rear end approaching the center in the width direction of the master. A phenomenon occurs, which causes a problem that the removal of the next printing plate is hindered.

  The present invention has a printing cylinder such as a stencil printing apparatus that has a printing drum and a plate discharging device that collects the master wound around the printing drum along with the rotation of the printing drum, and prevents a master conveyance failure at the time of collecting the master. The purpose is to provide.

In order to achieve the above object, the invention described in claim 1 includes a plate cylinder and a plate discharging device that collects the master wound around the plate cylinder as the plate cylinder rotates, and at least the entire ink adhering portion of the master. The recovery speed is changed to a low speed and / or the rotation speed is increased so that the recovery speed of the master and the rotation speed of the plate cylinder are approximately the same speed when the plate is separated from the plate cylinder. It is in a printing device that changes speed .

According to a second aspect of the invention, in the printing apparatus according to claim 1, further comprising a stencil discharge roller where the plate discharge device is recovered by rotating a master wound around the plate cylinder, the entire ink attaching at least part of the master is the plate The rotational speed of the plate discharge roller and the rotational speed of the plate cylinder are set to be substantially the same when leaving the cylinder.

According to a third aspect of the present invention, in the printing apparatus according to the second aspect of the present invention, the printing apparatus includes a DC motor that drives the plate discharge roller, and the rotation speed of the plate discharge roller and the plate are changed by changing a current value of the DC motor. It is characterized in that the rotational speed of the cylinder is substantially the same speed.

According to a fourth aspect of the present invention, in the printing apparatus according to the second aspect of the present invention, the printing apparatus includes a stepping motor that drives the plate discharging roller, and the rotation speed of the plate discharging roller and the plate are changed by changing the number of pulses of the stepping motor. It is characterized in that the rotational speed of the cylinder is substantially the same speed.

According to a fifth aspect of the present invention, in the printing apparatus according to the second aspect of the present invention, a motor for driving the discharge roller is provided, and the apparent rotation speed of the discharge roller is set by intermittently driving the motor. The rotational speed of the plate cylinder is substantially the same.

A sixth aspect of the present invention is the printing apparatus according to any one of the first to fifth aspects, further comprising a brushless motor for driving the plate cylinder, and changing a switching speed of each phase of the brushless motor. The rotational speed of the plate discharge roller and the rotational speed of the plate cylinder are substantially the same.

The invention according to claim 7 is the printing apparatus according to any one of claims 1 to 6 , wherein a timing at which the recovery speed of the master and the rotation speed of the plate cylinder by the plate discharging apparatus are set to substantially the same speed, It is characterized by changing according to the length of the master.

According to an eighth aspect of the present invention, in the printing apparatus according to any one of the first to seventh aspects, the recovery speed of the master by the plate removing device when recovering the ink adhering portion of the master is the rotation of the plate cylinder. It is characterized by being larger than the speed.

The present invention includes a plate cylinder and a plate discharging device that collects the master wound around the plate cylinder as the plate cylinder rotates, and at least when the entire ink adhering portion of the master leaves the plate cylinder, the plate discharging device. as the recovery rate of master and rotational speed of the plate cylinder is substantially same speed by, since the recovery speed shift to low speed and / or printing apparatus for shifting the rotational speed at a high speed, by the plate discharge device By changing the recovery speed of the master to a low speed and / or changing the rotation speed of the conveyance to a high speed, the remaining plate removal at the rear end of the master or the rear end of the master is the width of the master during the recovery of the master. The master can be satisfactorily transported to its rear end without causing troubles such as catching and winding of the master with respect to the discharge roller due to approaching the center in the direction. Failure can be prevented.

  The plate removal apparatus has a plate discharge roller for collecting the master wound around the plate cylinder by rotation, and at least when the entire ink adhering portion of the master leaves the plate cylinder, the rotation speed of the plate discharge roller and the rotation of the plate cylinder Assuming that the speed is substantially the same speed, by changing the rotation speed of the discharge roller provided in the discharge apparatus and changing the recovery speed of the master, the discharge of the rear end of the master at the time of recovery of the master is performed. The master can be satisfactorily transported to its rear end without causing problems such as catching or wrapping of the master against the discharge roller due to the rest or the rear end of the master approaching the center in the width direction of the master. In addition, it is possible to provide a printing apparatus that can prevent conveyance failure.

  If there is a DC motor that drives the discharge roller, and the rotational speed of the discharge roller and the rotation speed of the plate cylinder are made substantially the same by changing the current value of the DC motor, the discharge plate By changing the current value of the DC motor that drives the roller, changing the rotation speed of the discharge roller provided in the discharge apparatus, and changing the recovery speed of the master, the rear end of the master at the time of recovery of the master The master is transported satisfactorily to the rear end without causing any problems such as the remaining part of the plate remaining or the master's catching or winding around the discharge roller due to the rear end of the master approaching the center in the width direction of the master. Therefore, it is possible to provide a printing apparatus that can prevent conveyance failure.

  If there is a stepping motor that drives the discharge roller, and the rotation speed of the discharge roller and the rotation speed of the plate cylinder are made substantially the same by changing the number of pulses of the stepping motor, the discharge plate By changing the number of pulses of the stepping motor that drives the roller, changing the rotation speed of the plate discharge roller provided in the plate discharge device, and changing the master collection speed, the master trailing edge is changed during the master collection. The master is transported satisfactorily to the rear end without causing any problems such as the remaining part of the plate remaining or the master's catching or winding around the discharge roller due to the rear end of the master approaching the center in the width direction of the master. Therefore, it is possible to provide a printing apparatus that can prevent conveyance failure.

  If the motor for driving the discharge roller is provided and the drive by this motor is intermittent, the apparent rotation speed of the discharge roller and the rotation speed of the plate cylinder are made substantially the same speed. , The motor for driving the discharge roller is intermittently driven, the apparent rotation speed of the discharge roller provided in the discharge apparatus is changed, and the recovery speed of the master is changed. There is no problem with the remaining end of the plate at the rear end or the master's rear end at the center in the width direction of the master. It is possible to provide a printing apparatus that can be transported and can prevent transport failure.

  A brushless motor for driving the plate cylinder is provided, and the rotational speed of the plate discharge roller and the rotation speed of the plate cylinder are made substantially the same by changing the switching speed of each phase of the brushless motor. By changing the switching speed of each phase of the brushless motor that drives the plate cylinder, and changing the rotation speed of the plate cylinder to match the recovery speed of the master, at the time of recovery of the master, The master can be transported satisfactorily to its rear end without causing problems such as remaining master and the rear end of the master approaching the central portion in the width direction of the master. It is possible to provide a printing apparatus that can prevent conveyance failure.

  If the timing at which the recovery speed of the master by the plate removal device and the rotation speed of the plate cylinder are made substantially the same speed is changed according to the length of the master, the recovery speed of the master by the plate removal apparatus and the rotation of the plate cylinder By optimizing the speed to be approximately the same speed according to the length of the master, at the time of recovery of the master, the remaining plate removal at the rear end of the master or the rear end of the master is in the width direction of the master. Provides a printing device that can transport the master well to its rear end and prevent poor transport without causing problems such as catching and winding of the master with respect to the discharge roller due to approaching the central portion can do.

  If the recovery speed of the master by the plate removing device when recovering the ink adhering portion of the master is higher than the rotational speed of the plate cylinder, the master when recovering the ink adhering portion of the master during the recovery of the master is assumed. In addition to being able to improve the transportability of the master, the remaining master plate at the rear end of the master, the master's rear end portion being close to the central portion in the width direction of the master, the master being caught by the discharge roller, winding, etc. The master can be transported well to its rear end without causing problems, and it is possible to prevent poor transport during the master recovery and to shorten the time until the master recovery is completed. An apparatus can be provided.

FIG. 1 shows a stencil printing apparatus which is a printing apparatus to which the present invention is applied.
The stencil printing apparatus 100 includes an image reading apparatus 50 that is a scanner having a known configuration that reads an image of a document (not shown), and image information read by the image reading apparatus 50 or an image input by an external connection device such as a personal computer (not shown). It has a plate making apparatus 51 for making a plate of the master 8 and feeding it based on the information, and a printing drum 1 as a plate cylinder.

  The stencil printing apparatus 100 also peels the printing paper P from the printing drum 1, a paper feeding device 52 that feeds the printing paper P toward the printing drum 1, a pressing means 57 that presses the printing paper P against the printing drum 1. The sheet peeling device 25 to be discharged, the paper discharge conveying device 53 for sucking and conveying the printing paper P peeled from the printing drum 1 by the paper peeling device 25, and the printing paper P conveyed by the paper discharge conveying device 53 is discharged and accommodated. A paper discharge tray 54, a plate discharging device 55 as a plate discharging unit for peeling the used master 8 from the outer peripheral surface of the printing drum 1, a control means (not shown) for controlling the overall operation of the stencil printing device 100, and a start button (not shown) And an operation panel provided with a numeric keypad.

  The plate making apparatus 51 is arranged with a holder member (not shown) that rotatably supports the master 8 wound around the core material 8b through the core material 8b, and the master 8 in the feeding direction downstream. , A platen roller 10 rotatably supported by a plate making unit side plate (not shown), a thermal head 11 having innumerable heating elements, a guillotine type cutter 12 for cutting the master 8 made into a predetermined length, and plate making The reversing roller pair 13 is rotatably supported by the part side plate, and the curved guide plate 14 guides the front end of the master 8 made to the plate to the clamper 7 described later.

The thermal head 11 is urged toward the platen roller 10 by urging means (not shown), whereby the master 8 is pressed against the platen roller 10.
The platen roller 10 is rotated in the clockwise direction by a stepping motor (not shown), whereby the master 8 is fed out from the master roll 8a.

The cutter 12 has an upper blade 12a and a lower blade 12b. As the cutter 12, a rotary blade moving type may be adopted.
The reversing roller pair 13 is provided in a state of being pressed against each other. The reverse roller pair 13 is set to a speed slightly higher than the peripheral speed of the platen roller 10, and applies an appropriate tension to the master 8 while sliding with the master 8.

  An ADF as an automatic document feeder (not shown) that separates and conveys a document is provided above the image reading device 50. The image reading apparatus 50 has a well-known function of reading a document conveyed by the ADF while automatically automatically conveying it, or reading a document placed on a contact glass surface (not shown) without using the ADF.

  The printing drum 1 has a configuration in which a plurality of mesh screens of a resin or metal net (not shown) are wound around the outer periphery of a porous support cylindrical body 1a. Both ends of the printing drum 1 are fixed to a flange (not shown) rotatably supported by an ink pipe 5 as a support shaft, and a driving force of a brushless motor (not shown) serving as a plate cylinder driving means is driven by a drive transmission means such as a gear (not shown). Is transmitted and rotated in the clockwise direction.

  Inside the printing drum 1, side plates (not shown) are fixed to the ink pipe 5 at intervals in the drum axis direction which is perpendicular to the paper surface of FIG. 1, and the ink roller 2 is interposed between these side plates. The part is supported so as to be rotatable. The ink roller 2 is driven to rotate in the same direction in synchronism with the printing drum 1 by being transmitted with the driving force of the brushless motor by a drive transmission means such as a gear or a belt (not shown).

  A doctor roller 3 is provided at a slight distance from the outer peripheral surface of the ink roller 2, and the doctor roller 3 inks the ink in the wedge-shaped ink reservoir 4 formed between the ink roller 2 and the doctor roller 3. A thin film is supplied to the outer peripheral surface of the roller 2. The ink in the ink reservoir 4 is sucked from an ink pack or the like provided outside the printing drum 1 by an ink supply device (not shown), supplied dropwise from the supply hole 5a of the ink pipe 5, and rotated by the ink roller 2 and the doctor roller 3. Are kneaded.

  On the surface of the non-perforated portion of the printing drum 1, a stage 6 that is formed of a magnetic material and has a flat surface is provided along one generating line of the printing drum 1. A clamper 7 is rotatably supported parallel to the stage 6 and the drum axis direction, and the clamper 7 is opened and closed at a predetermined position by an opening / closing device (not shown). By the closing operation of the clamper 7, the front end portion of the master 8 that has been subjected to the plate making supplied from the plate making apparatus 51 is sandwiched between the stage 6. The printing drum 1 can be attached to and detached from the main body of the stencil printing apparatus in the axial direction as a unit integrated with the ink pack or the like.

  The pressing means 57 is provided below the printing drum 1. The pressing means 57 includes an arm shaft 22a rotatably supported on a side plate (not shown) of the stencil printing apparatus 100 main body, a press roller arm pair 22 fixed at one end to the arm shaft 22a, a press roller arm pair 22, and the like. It has a press roller 23 that is rotatably supported with a shaft portion supported on the end side.

  A cam follower (not shown) is provided on one end side of the arm shaft 22a, and is brought into contact with and separated from the printing drum 1 by a biasing means (not shown) along a cam (not shown) that rotates in synchronization with the printing drum 1. ing. The press roller 23 is held at a position indicated by a solid line separated from the printing drum 1 by a locking means (not shown) except during printing.

  The paper feeding device 52 includes a feed tray 58 that can be moved up and down to load and collect printing paper P, and a paper feeding roller 59 that separates and feeds the printing paper P one by one from the top. , 60 and the separation roller 61, the pair of registration rollers 20 that convey the separated and fed printing paper P to the printing pressure section between the printing drum 1 and the press roller 23 at a predetermined timing, and the printing paper P is the printing drum 1. It has a paper sensor (not shown) that detects that it has entered between the press roller 23.

  The paper peeling device 25 is disposed on the lower left side of the printing drum 1 and below the plate discharging device 55, and has a built-in fan 26 for peeling the printing paper P from the printing drum 1 toward the printing drum 1. A blower 27 that blows the airflow, and a rotatable peeling claw 62 that is disposed in the flow path of the airflow by the blower 27 and peels the printing paper P from the surface of the printing drum 1 in the vicinity of the printing drum 1. have.

The paper discharge transport device 53 includes a transport belt 63 that rotates counterclockwise and a fan 64 that is disposed below the transport belt 63.
On the paper discharge tray 54, the air flow by the blower 27 and the printing paper P peeled off from the printing drum 1 by the peeling claw 62 are transported while being attracted by the suction force of the fan 64 by the transport belt 63 of the paper discharge transport device 53. Discharged.
The control means includes a CPU, a ROM, a RAM, and the like, and controls the overall operation of the stencil printing apparatus 100 by controlling various motors provided in the stencil printing apparatus 100.

  The plate discharging device 55 is disposed on the left side of the printing drum 1. The plate discharging roller pair 56 that pulls and collects the used master 8 that is wound around the outer peripheral surface of the printing drum 1 while pulling it away, and the plate discharging roller pair. A plate discharging unit 35 for storing the waste master 8d collected by the 56, a plate discharging box 39 detachable with respect to the plate discharging unit 35, and a waste master disposed on the left side of the plate discharging roller pair 56 are compressed in the plate discharging unit 35. It has a compression plate 34 as a compression member and detection means (not shown) for detecting that the tip of the discard master 8d has been drawn into the plate discharge roller pair 56.

  The plate discharge roller pair 56 includes a plate discharge roller upper 31 as a plate discharge roller pressed against each other, a plate discharge roller lower 33 as a plate discharge roller, and an impeller 32 disposed integrally with the plate discharge roller 31. The shaft portion 31a of the upper 31 and the impeller 32 and the shaft portion 33a of the lower plate roller 33 are rotatably supported by a platen unit side plate (not shown).

  The upper plate roller 31 and the impeller 32 are formed of an elastic material such as nitrile rubber or silicon rubber. The lower discharge roller 33 is formed of a resin such as ABS resin or polyacetal resin. If the upper plate roller 31 and the impeller 32 are integrally formed of the same material, manufacture and assembly are facilitated.

As shown in FIG. 2, a plurality of discharge roller pairs 56 are provided at intervals in the drum axis direction. Of each of the plate discharging rollers 31, the width of the plate discharging roller 31 located at both ends is smaller than the width of the other plate discharging rollers 31.
The impeller 32 is disposed on one side of each pair of discharge roller 56 and is configured to rotate synchronously with the upper discharge roller 31. The impeller 32 has a roller-like base portion 32b fixed to the rotation shaft 31a, and a length that extends radially from the base portion 32b in the radial direction of the upper plate roller 31 and protrudes outward from the outer diameter of the upper plate roller 31. A plurality of elastic blades 32a having a thickness are provided.

  The elastic blade 32a is formed in a columnar shape having a small cross-sectional area so as to minimize contact with the disposal master 8d, specifically, a prismatic shape having a square cross section with a side of about 1 to 2 mm. It deform | transforms so that it may contact | abut 33 and bend. Since the elastic blade 32a has a columnar shape with less contact with the discard master 8d, sticking of the discard master 8d is reduced.

  The elastic blade 32a comes into contact with the tip of the waste master 8d to draw the waste master 8d into the nip portion between the upper plate discharge roller 31 and the lower plate discharge roller 33, and strikes the waste master 8d on the peripheral surface of the upper discharge roller 31. It has a function of preventing the disposal master 8d from sticking. The elastic blade 32a prevents sticking of the disposal master 8d after being accommodated by a swinging-down action due to its restoring repulsive force.

  The upper discharge roller 31 and the lower discharge roller 33 are rotationally driven in opposite directions by a common motor (not shown) as a driving means and a transmission means (not shown) that transmits the drive of the motor to the shaft portions 31a and 33a. The driving of the motor is performed by the control means in association with the driving of the brushless motor that drives the printing drum 1, and details thereof will be described later.

  As shown in FIG. 1, the compression plate 34 is rotatably supported at one end side between the plate discharge unit side plates and is rotated in the direction indicated by the arrow. The free end side of the compression plate 34 passes through a position close to the plate discharge roller pair 56 and compresses the waste master 8d along the wall surface of the plate discharge portion 35 while pressing the discharged waste master 8d. The disposal master 8d is accommodated in the inside of the discharge box 39 at the back.

The compression plate 34 is driven at a predetermined timing by a motor or the like (not shown). A protrusion 38 is provided on the compression surface side of the free end portion, which is the distal end portion of the compression plate 34, so that it does not remain in the compression conveyance path by being dragged while hooking the waste master 8d when the waste master 8d is rotated and compressed. I have to.
The plate discharging box 39 has a handle 39a and is detachably attached to the plate discharging unit 35, and the disposal master 8d that is full can be appropriately discarded by grasping the handle 39 and pulling it out from the plate discharging unit 35. ing.

  A printing operation of the stencil printing apparatus 100 having the above configuration will be described. A document is set on an ADF (not shown), and the number of prints is input and set using a numeric keypad on the operation panel. When a start button or the like is pressed, a start signal is output, and the printing drum 1 is rotated clockwise by a brushless motor.

  As shown in FIG. 3, the printing drum 1 rotates and stops until the clamper 7 reaches a home position which is a predetermined position close to the plate discharge roller pair 56. At this time, the clamper 7 is opened by the opening / closing device. Since the front end portion of the master 8 is an unattached portion of ink, the master 8 is lifted as shown in FIG.

  Simultaneously with the release of the clamper 7, the discharge roller pair 56 rotates to bring the raised tip of the master 8 into contact with the elastic blade 32 a of the impeller 32 and draw it into the nip portion between the upper discharge roller 31 and the lower discharge roller 33. In addition, since the rear end portion of the master 8 is also a non-ink-attached portion, it floats from the peripheral surface of the printing drum 1 as shown in FIG.

  When it is detected by the detecting means that the leading end of the master 8 is drawn into the nip portion between the upper plate discharging roller 31 and the lower plate discharging roller 33, the printing drum 1 resumes rotating as shown in FIG. Is held between the upper plate roller 31 and the lower plate roller 33 as the printing drum 1 rotates, and is peeled off from the surface of the printing drum 1 while being prevented from sticking to the upper plate roller 31 by the impeller 32. 34 is collected and stored in a space between the plate 34 and the plate discharging portion 35 in a bellows shape. At this time, the clamper 9 is closed by the opening / closing device.

When the peeling of the master 8 is completed, the printing drum 1 is rotated and stopped until the clamper 7 reaches the plate feeding position, and then the clamper 7 is opened by the opening / closing device to enter a plate feeding standby state.
In the plate feeding standby state, the document is conveyed to the image reading device 50 and read, and the heating elements of the thermal head 11 are energized in pulses in accordance with the read image information. The plate making by which the thermal head 11 is operated in the main scanning direction, and the stepping motor is rotated and the master 8 is conveyed in the sub scanning direction by the platen roller 10 and the reverse roller pair 13 etc., and the thermal film of the master 8 is heated and punched. Is done.

  The leading end of the master 8 is guided between the stage 6 and the clamper 7 by the guide plate 14. When it is determined that the tip of the master 8 has reached the clamping region of the clamper 7 based on information such as the number of steps of the stepping motor, the clamper 7 is closed and clamped by the opening / closing device. As the leading end of the master 8 is sandwiched, the printing drum 1 resumes rotating at a speed substantially equal to the conveying speed of the master 8 and the master 8 thus made is wound.

  When it is determined that the plate making is completed based on the number of steps of the stepping motor, the cutter 12 is operated to cut the master 8 and the platen roller 10 and the reverse roller pair 13 are stopped. The end is pulled out by the rotation of the printing drum 1 and the master winding around the printing drum 1 is completed.

In parallel with this plate feeding / winding operation, the compression plate 34 in the plate discharging device 55 rotates in the clockwise direction, and the waste master 8d stored in a bellows shape is moved along the wall surface of the plate discharging box 35 to the back. The waste master 8d is compressed and stopped at a predetermined position while being pressed.
After a predetermined time, the compression plate 34 rotates counterclockwise and returns to the initial position.

  When the pre-printing master 8 has been wound around the printing drum 1, one sheet of printing paper P is fed from the paper feed tray 58, and the printing drum 1 and the press roller 23 are rotated by the registration roller pair 20 that rotates at a predetermined timing. It is transported between. When the entry of the printing paper P is detected by the paper sensor, the locking means of the pressing means 57 is released, so that the press roller 23 rises along the rotation of a cam (not shown), and the printing paper P is loaded on the printing drum 1. Pressing is performed to fill the master 8 with ink.

As a result, ink adhering portions are formed at portions other than the front end portion and the rear end portion of the master 8, and the master 8 is in close contact with the printing drum 1 at this portion and is in a state of being stuck thereto.
The printing paper P is peeled off from the surface of the printing drum 1 by the peeling claw 62 approaching the printing drum 1 and the airflow from the blower 27, transported by the paper discharge transport device 53, and discharged and stacked on the paper discharge tray 54. . Thereafter, the set number of prints is performed in the same operation.

  In such an operation, the plate removing device 55 considers the variation in the recovery speed of the master 8 at the time of recovery of the master and sets the recovery speed of the master 8 of the printing drum 1 for the purpose of preventing meandering of the recovered master 8. Therefore, the control means associates the recovery speed of the master 8 with the drive of the motor that drives the upper plate roller 31 and the lower roller 33 and the brushless motor that drives the printing drum 1, and the printing drum. The rotational speeds of these motors are adjusted to be 1.2 times the rotational speed of 1.

  Further, as described above, the master 8 has an ink adhering portion and an unattached portion, and only the ink adhering portion is attached to the peripheral surface of the printing drum 1. For this reason, the master 8 is collected with a predetermined tension between the plate discharging device 55 and the printing drum 1 in a state where the ink adhering portion is wound around the printing drum 1. At this time, the speed difference between the plate discharging device 55 and the printing drum 1 is eliminated by causing a slip between the plate discharging device 55, specifically, between the upper plate discharging roller 31 and the lower plate discharging roller 33 with the disposal master 8d. .

  However, when recovery of the master 8 progresses and the ink adhering portion is peeled off from the printing drum 1, the discarding master 8d is released from the tension at a stretch and becomes free. There is a risk that a defect in the conveyance failure at the rear end of the discard master 8d between them will occur.

  That is, as shown in FIG. 6, the remaining plate is removed at the rear end of the discard master 8d, or as shown in FIG. 7, the removed plate is caused by the rear end of the discard master 8d approaching the center in the width direction of the discard master 8d. There is a possibility that problems such as catching of the disposal master 8d with respect to the upper roller 31 and the lower plate discharging roller 33 and other wrapping not shown in the figure may occur.

  Furthermore, due to these problems, as shown in FIG. 8, there is a possibility that a take-out phenomenon of the discard master 8d by the compression plate 34 occurs, which may cause a problem that the removal of the plate at the next discharge is obstructed. The take-away phenomenon is a phenomenon in which the compression plate 34 rotates counterclockwise after the disposal master 8d is compressed and pulls up the disposal master 8d that should have completed the compression when returning to the initial position. This causes a compression failure of the master 8d.

Therefore, in the stencil printing apparatus 100, when the uninked portion of the master 8 is recovered, the control means controls so that the recovery speed of the master by the discharging apparatus 55 and the rotation speed of the printing drum 1 are substantially the same. Is supposed to do.
Specifically, the control means changes the collection speed of the master 8 by the plate removal device 55, that is, shifts to a low speed, so that the collection speed of the master 8 by the plate removal device 55 and the rotation speed of the printing drum 1 are substantially the same speed. And

  For this purpose, the control means sets the rotational speeds of the upper roller 31 and the lower roller 33 to be approximately the same as the rotational speed of the printing drum 1. Here, the motor for driving the upper plate roller 31 and the lower plate roller 33 is a DC motor in this embodiment, and the control means changes the current value of the DC motor, whereby the upper plate roller 31 and the upper plate roller are discharged. The rotation speed with the lower roller 33 is set to be substantially the same as the rotation speed of the printing drum 1.

Such a motor may be another motor instead of a DC motor. When the motor is a stepping motor, the number of pulses of the stepping motor is changed by the control means, whereby the upper plate discharge roller 31 and the lower plate discharge roller 33 Can be made substantially the same speed as the rotation speed of the printing drum 1.
Further, the drive by various motors is intermittently driven by the control means so that the apparent rotational speed between the upper plate roller 31 and the lower roller 33 is substantially the same as the rotational speed of the printing drum 1. May be.

Furthermore, instead of or at the same time as lowering the collection speed of the master 8 by the plate removal apparatus 55, the rotation speed of the printing drum 1 is changed, that is, the speed is changed to high speed, whereby the master 8 is collected by the plate removal apparatus 55. The speed and the rotation speed of the printing drum 1 may be substantially the same speed.
Since the motor for driving the printing drum 1 is a brushless motor, in this case, the control means changes or speeds up the switching speed of each phase of the brushless motor, so that the upper plate discharge roller 31 and the lower plate discharge roller 33 Can be made substantially the same speed as the rotation speed of the printing drum 1.

  Since a motor other than the brushless motor can be used as the motor for driving the printing drum 1, a method corresponding to the motor can be used as the speed change method. The same applies to the motor that drives the upper plate roller 31 and the lower plate roller 33.

  The timing at which the recovery speed of the master 8 and the rotation speed of the printing drum 1 by the plate removing device 55 are made substantially the same speed is at least when the entire ink adhering portion of the master 8 moves away from the peripheral surface of the printing drum 1, that is, the master 8. However, considering the transportability of the master 8, the same timing as when the ink adhering portion of the master 8 is separated from the peripheral surface of the printing drum 1 is acceptable. In the stencil printing apparatus 100, the control means performs such control.

  However, since the size of the master 8 is changed depending on the size of the original and the area of the ink adhering portion of the master 8 is affected by this, the timing at which the entire ink adhering portion of the master 8 is separated from the peripheral surface of the printing drum 1 is also affected. Depending on the size of the master 8, in other words, the length of the master 8. Therefore, in the stencil printing apparatus 100, the control means changes the timing at which the recovery speed of the master 8 by the plate removal apparatus 55 and the rotation speed of the printing drum 1 are made substantially the same speed according to the length of the master 8. It has become.

  Specifically, as shown in FIG. 4, based on the angle θ of rotation of the printing drum 1 with reference to the home position of the printing drum 1 where the clamper 7 is expanded, which is indicated by a two-dotted line in FIG. The control means is configured so that the recovery speed of the master 8 by the plate removal device 55 and the rotation speed of the printing drum 1 are substantially the same speed, and the master 8 corresponds to the B4 size when the size corresponds to the A3 size. For each of the sizes corresponding to the A4 size, the control means controls the recovery speed of the master 8 by the plate removal device 55 and the printing drum when θ becomes 165 °, 143 °, and 83 °. The rotational speed of 1 is substantially the same speed.

  As a result, the above-described discard master remaining at the rear end of the discard master 8d, or the discard master for the upper discharge roller 31 and the lower discharge roller 33 due to the rear end of the discard master 8d approaching the center in the width direction of the discard master 8d. There is no problem such as catching or winding of 8d, and there is no take-back phenomenon of the discard master 8d by the compression plate 34. As shown in FIG. 5, the discard master 8d is transported well to its rear end, There is no conveyance failure and the compression is good.

As described above, the stencil printing apparatus 100 as a printing apparatus has been described as an embodiment for carrying out the present invention. However, the present invention collects not only the stencil printing apparatus but also the master wound around the plate cylinder as the plate cylinder rotates. Any printing apparatus provided with a plate removal apparatus can be applied to other types of printing apparatuses.
The sameness of these speeds when the recovery speed of the master by the plate removal device and the rotation speed of the plate cylinder are substantially the same may be in a range that can prevent the above-described problems, and is completely the same. It is not a thing.

The recovery speed of the master by the plate removing device and the rotation speed of the plate cylinder should be substantially the same as long as at least the entire ink adhering portion of the master is separated from the plate cylinder, and the entire ink adhering portion of the master is the plate cylinder. It may be before leaving.
If the recovery speed of the master by the plate removal device and the rotation speed of the plate cylinder are approximately the same when the entire ink adhering part of the master is separated from the plate cylinder, the relationship between these speeds does not need to be maintained thereafter. For example, if the recovery speed of the master by the plate removal device is made faster than the rotation speed of the plate cylinder, the time until the recovery of the master is completed is shortened.
The application of the present invention is not limited to the above-described embodiment unless particularly limited in the above description.

1 is a schematic front view of a stencil printing apparatus to which the present invention is applied. FIG. 2 is a plan view of a part of a plate discharging apparatus of the stencil printing apparatus shown in FIG. 1. It is a front view which shows the home position of the plate cylinder of the stencil printing apparatus shown in FIG. FIG. 2 is a front view illustrating a state in which a plate cylinder of the stencil printing apparatus illustrated in FIG. 1 is rotated by an angle θ from a home position. It is a top view which shows a mode that a part of plate discharging apparatus shown in FIG. 2 conveys a master favorably. It is a front view which shows the malfunction of the conveyance of a master. It is a top view which shows the malfunction of the conveyance of a master. It is a front view which shows the other malfunction of conveyance of a master.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plate cylinder 8, 8d Master 31, 33 Discharge roller 55 Discharge apparatus 100 Printing apparatus

Claims (8)

A plate cylinder and a plate discharging device that collects the master wound around the plate cylinder with the rotation of the plate cylinder, and at least when the entire ink adhering portion of the master is separated from the plate cylinder, the master is collected by the plate discharging device. A printing apparatus that shifts the recovery speed to a low speed and / or shifts the rotation speed to a high speed so that the speed and the rotation speed of the plate cylinder are substantially the same . 2. The printing apparatus according to claim 1, wherein the plate discharging device has a plate discharging roller for collecting the master wound around the plate cylinder by rotation, and at least when the entire ink adhering portion of the master is separated from the plate cylinder. The printing apparatus is characterized in that the rotation speed of the plate cylinder and the rotation speed of the plate cylinder are substantially the same . The printing apparatus according to claim 2, further comprising a DC motor that drives the plate discharge roller, and changing a current value of the DC motor so that the rotation speed of the plate discharge roller and the rotation speed of the plate cylinder are substantially the same. A printing apparatus characterized by a high speed . 3. The printing apparatus according to claim 2 , further comprising a stepping motor that drives the discharge roller, and the rotation speed of the discharge roller and the rotation speed of the plate cylinder are substantially the same by changing the number of pulses of the stepping motor. A printing apparatus characterized by a high speed . The printing apparatus according to claim 2 , further comprising: a motor that drives the plate discharge roller , wherein an apparent rotation speed of the plate discharge roller and a rotation speed of the plate cylinder are obtained by intermittently driving the motor. A printing apparatus characterized by substantially the same speed . 6. The printing apparatus according to claim 1 , further comprising: a brushless motor that drives the plate cylinder, and changing a switching speed of each phase of the brushless motor to change a rotation speed of the plate discharge roller. A printing apparatus characterized in that the rotational speed of the plate cylinder is substantially the same . 7. The printing apparatus according to claim 1, wherein the timing at which the recovery speed of the master and the rotation speed of the plate cylinder by the plate discharging apparatus are set to substantially the same speed is changed according to the length of the master. A printing apparatus characterized by that. 8. The printing apparatus according to claim 1 , wherein a recovery speed of the master by the plate discharging apparatus when recovering an ink adhering portion of the master is higher than a rotation speed of the plate cylinder. Printing device.

Images