JP4437577B2 - Printing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention wraps a pre-printed master around the outer periphery of a plate cylinder, presses the printing paper fed from the paper feeding unit against the master on the plate cylinder by a pressing body such as a press roller or an impression cylinder, and displays the master image. The present invention relates to a printing apparatus configured to transfer to printing paper.
[0002]
[Prior art]
First, an example of a conventional printing apparatus will be described. FIG. 6 is a longitudinal front view showing a schematic configuration of the printing apparatus. Reference numeral 1 denotes a plate cylinder. Around the plate cylinder 1, a plate discharging device (not shown) for peeling off and collecting a used master wound around the plate cylinder 1 and a plate making device 2 are provided. The plate making apparatus 2 includes a holder (not shown) that holds a core 3a of an unused master 3 wound in a roll shape, a platen 4 that is driven to rotate, and a biasing force of a spring (not shown). 4, a thermal head 5 that is press-contacted to the plate 4, a cutter 6 that cuts the master 3 that has been subjected to plate making, a pair of transport rollers 7 that transport the master 3 toward the plate cylinder 1, and the master 3 that is the plate cylinder 1. And a guide plate 8 that is guided toward the vehicle. The platen 4 is connected to a stepping motor (not shown). The cutter 6 uses a guillotine type, but is not limited to a rotary type.
[0003]
The peripheral speed of the transport roller 7 is set to a peripheral speed slightly higher than the peripheral speed of the platen 4 so that a desired tension is applied to the master 3 during transport.
[0004]
In this embodiment, the master 3 is formed by laminating a thermoplastic resin film in a laminate structure on a porous support sheet obtained by combining Japanese paper fibers, synthetic fibers, or both.
[0005]
Although not shown in detail, the plate cylinder 1 is formed by winding a plurality of resin or metal mesh screens around the outer periphery of the porous cylinder, and fixing flanges to both ends of the porous cylinder. It is a known structure connected to the motor. The flange of the plate cylinder 1 is rotatably supported by an ink supply shaft 9 fixed at both ends by side plates (not shown). The ink supply shaft 9 is connected to an ink supply device (not shown).
[0006]
Further, a pair of side plates (not shown) fixed to the ink supply shaft 9 and opposed to each other are provided inside the plate cylinder 1, and the ink roller 10 and the doctor roller 11 are rotatable on these side plates. It is supported. The ink roller 10 and the doctor roller 11 are arranged in parallel with a slight gap therebetween, and a space formed in a wedge shape by the two receives ink dropped from an ink dropping hole 12 formed in the ink supply shaft 9. This is the ink reservoir 13. Further, on the surface of the non-opening portion other than the mesh screen of the plate cylinder 1, a stage 14 formed of a magnetic material and a clamper 15 for sandwiching the tip of the master 3 between the stage 14 are provided. It is provided along the bus. The clamper 15 is driven by an opening / closing drive unit (not shown) so as to rotate about a shaft 16.
[0007]
Cams 17 are integrally formed on the flanges at both ends of the plate cylinder 1. A part of the outer periphery of the cam 17 is formed with a protrusion 17a that is slightly longer than the area occupied by the stage 14 and the clamper 15 in terms of the length of the outer peripheral arc. Both sides of the projection 17a are smoothly connected to the circular portion 17c of the cam 17 by an inclined surface 17b whose radius from the center of the plate cylinder 1 changes.
[0008]
A press roller 18 as a pressing body is provided below the plate cylinder 1. On the upstream side of the press roller 18, there are a pair of registration rollers 19 that are aligned with the leading ends of the printing paper fed by a paper feed unit (not shown) and are driven to rotate in synchronization with the rotational movement of the plate cylinder 1. Is provided.
[0009]
The shaft 20 protruding from both ends of the press roller 18 is rotatably supported by a pair of roller arms 51 that rotate about a support shaft 50. The roller arm 51 is urged clockwise by a tension coil spring 52.
[0010]
A circular cam follower 21 smaller than the outer diameter of the press roller 18 is provided at both ends of the shaft 20 of the press roller 18. Further, a locking means 24 is provided for holding the roller arm 51 in the locked state at the retracted position when not printing, and releasing the locked state with the roller arm 51 prior to printing. The locking means 24 is formed by a locking lever 26 that is rotatably supported by a support shaft 25, and a solenoid 27 that drives the locking lever 26 in the rotation direction. A pin 51 a that is locked to the locking lever 26 is planted on the side surface of the roller arm 51.
[0011]
Although not shown, a scanner and an operation panel for reading a document image and outputting the read image data to the plate making apparatus 2 are provided above the plate cylinder 1 and the plate making apparatus 2. The operation panel includes a plurality of keys for performing operations necessary for printing. These keys include a plate making start key for inputting a plate making start command signal. The other keys are not directly related to the present invention and will not be described.
[0012]
Next, the operation will be described. When an original is set on the scanner and the prepress start key on the operation panel is pressed, the scanner starts reading the original. During this time, the plate cylinder 1 is driven to rotate, and in this process, the used master 3 on the plate cylinder 1 is peeled off and collected by the plate removing device. When the used master 3 is collected, the plate cylinder 1 is rotated to a position where the clamper 15 is directly below the guide plate 8, the clamper 15 is opened, and the plate feed standby state is maintained.
[0013]
On the other hand, the plate making apparatus 2 generates heat by the heating elements of the thermal head 5 based on the image data read by the scanner, and forms dots by perforation in the master 3. This dot formation is performed each time the master 3 is fed one line by the platen 4 and the conveying roller 7. The master 3 thus made is guided between the stage 14 of the plate cylinder 1 and the clamper 15 by the guide plate 8, and the tip of the master 3 is clamped by the clamper 15 by means such as counting drive pulses of a stepping motor that drives the platen 4. The clamper 15 is closed. That is, the tip of the master 3 is sandwiched between the stage 14 and the clamper 15. At this point, the plate cylinder 1 is driven to rotate clockwise at a speed equal to the conveying speed of the master 3, whereby the master 3 is wound around the plate cylinder 1.
[0014]
When it is recognized that the plate making is completed by means such as counting the drive pulses of the stepping motor that drives the platen 4, the master 3 is cut by the cutter 6, and the rear end of the cut master 3 is rotated by the plate cylinder 1. Is wound around the plate cylinder 1, and the winding of the master 3 is completed here.
[0015]
Subsequently, the paper feeding unit sends out printing paper. The fed printing paper is brought into contact with the nip portion of the registration roller 19 maintained in a stopped state, and the leading edge is aligned.
[0016]
When the registration roller 19 rotates in synchronization with the rotational movement of the plate cylinder 1 under the control of a conveyance drive unit (not shown), the printing paper is sent out toward the plate cylinder 1. When the sheet passes between the plate cylinder 1 and the press roller 18, a sensor (not shown) provided in the passage path outputs a passage detection signal, so that the solenoid 27 is excited by using the signal as a trigger, and the locking lever. 26 rotates clockwise about the support shaft 25 and disengages from the pin 51 a of the roller arm 51, so that the roller arm 51 rotates clockwise about the support shaft 50 by the urging force of the tension coil spring 52. As a result, the press roller 18 presses the printing paper against the master 3 on the plate cylinder 1. The press roller 18 rotates following the rotation of the plate cylinder 1. As a result, the ink in the plate cylinder 1 oozes out from the perforations of the master 3 and is transferred to the paper. That is, printing is performed.
[0017]
During printing, the solenoid 27 continues to be excited, and the locking lever 26 releases the roller arm 51, so that the press roller 18 is brought into contact with and separated from the plate cylinder 1 by the cam 17 that rotates integrally with the plate cylinder 1. That is, when the cam follower 21 of the press roller 18 is pressed by the protrusion 17 a of the cam 17, the roller arm 22 moves against the urging force of the tension coil spring 52 to the retreat position where it is retracted from the plate cylinder 1 together with the press roller 18. It rotates counterclockwise around the support shaft 50. In this case, since the protrusion 17a is arranged corresponding to the position of the clamper 15, the press roller 18 is retracted downward only when the clamper 15 passes directly above it, so as to avoid interference with the clamper 15. When printing continuously, the roller arm 51 is continuously maintained in the released state, and when the clamper 15 passes just above the press roller 18, that is, the protrusion 17a of the cam 17 passes over the cam follower 21. At this time, the roller arm 51 is again rotated clockwise by the urging force of the tension coil spring 52, so that the press roller 18 presses the printing paper against the master 3 on the plate cylinder 1.
[0018]
When the cam follower 21 is pressed by the protrusion 17a of the cam 17 and the press roller 18 is displaced together with the roller arm 51 to the retracted position, the pin 51a is positioned slightly below the tip of the locking lever 26. When printing is not performed, the locking lever 26 is locked to the pin 51a and the roller arm 51 is moved to the retracted position by deactivating the solenoid 27 during the period in which the protrusion 17a presses the cam follower 21. Hold.
[0019]
[Problems to be solved by the invention]
As described above, when the press roller 18 is brought into contact with and separated from the plate cylinder 1, in the conventional structure described so far, the urging force of the tension coil spring 52 is such that the press roller 18 is in contact with the plate cylinder 1. Sometimes the minimum, and the maximum when the roller arm 51 is displaced to the retracted position. When the locking lever 26 is removed from the roller arm 51 held in the retracted position, the urging force of the tension coil spring 52 is strong, so the cam follower 21 of the press roller 18 collides with the protrusion 17a of the cam 17 with a strong urging force. A loud collision sound will be generated. In particular, when the plate cylinder 1 is continuously rotated for the warm-up operation, the noise of the collision is conspicuous because no printing paper conveyance noise or printing paper tension sound is generated during printing. .
[0020]
Further, during printing in which the plate cylinder 1 is rotated in the clockwise direction, during the period in which the cam follower 21 of the press roller 18 is in contact with the inclined surface 17b of the cam 17, the pressing force received by the cam 17 from the cam follower 21 is strong. Since the pressing force acts at a position deviated from the center of rotation of the plate cylinder 1, the rotational speed of the plate cylinder 1 changes. For example, when the cam follower 21 comes into contact with the inclined surface 17b of the cam 17 by the rotation of the plate cylinder 1 from the state in which the cam follower 21 is in contact with the protrusion 17a, the cam 17 receives a clockwise force together with the plate cylinder 1. The rotational speed of the plate cylinder 1 is increased. Accordingly, there is a problem that the master 3 is also shifted in the clockwise direction, and the printing position on the printing paper is shifted.
[0021]
As described above, the structure in which the cam 17 controls the contact / separation operation of the press roller 18 with respect to the plate cylinder 1 is not limited to that shown in FIG. 6, but is described in Japanese Patent Laid-Open No. 9-20055. In the stencil printing apparatus described in the above, the urging force of the press roller with respect to the plate cylinder is stronger when the press roller is retracted from the plate cylinder than when the press roller is in contact with the plate cylinder. A problem similar to the problem seems to occur.
[0022]
An object of the present invention is to reduce noise accompanying the contact operation of a pressing body with respect to a plate cylinder, and to prevent a change in rotational speed of the plate cylinder during printing.
[0023]
[Means for Solving the Problems]
The invention according to claim 1 is a plate cylinder which has a clamper for holding an edge of the master made by plate making a part of its outer periphery and is driven to rotate, and a pressing body which presses the printing paper against the master on the plate cylinder. A displaceable movable body that rotatably supports a protrusion, and a protrusion that displaces the pressing body together with the movable body to a retreat position that retracts from the plate cylinder at a timing when the clamper faces the pressing body. And a cam that rotates in synchronization with the rotational movement of the plate cylinder, and holds the movable body or the pressing body in a locked state at the retracted position when not printing, and the movable body or the Locking means for releasing the locking state with the pressing body, and a printing pressure that urges the movable body by increasing the urging force of the pressing body to the plate cylinder as the pressing body moves toward the plate cylinder. Generating means.
[0024]
Therefore, at the time of non-printing, the movable body or the pressing body is locked by the locking means and held at the retracted position. Prior to printing, when the locking state of the movable body or the pressing body and the locking means is released, the pressing body advances to the plate cylinder side together with the movable body by the urging force of the printing pressure generating means, and is determined by the printing pressure generating means. The pressing body presses the printing paper against the master on the plate cylinder by the applied urging force. In the process of rotationally driving the plate cylinder at the time of printing, the pressing body retreats from the plate cylinder by the protrusion of the cam together with the movable body against the urging force of the printing pressure generating means at the timing when the clamper faces the pressing body. It is displaced to the retracted position. When the pressing body advances to the plate cylinder side together with the movable body, since the urging force of the printing pressure generating means is weak, the impact sound with the cam is reduced. When the pressing body presses the printing paper against the master on the plate cylinder, the urging force of the printing pressure generating means is the strongest, and when the pressing body is retracted from the plate cylinder together with the movable body, the urging force of the printing pressure generating means is weak. As a result, the torque received by the protrusion of the cam from the pressing body or the movable body is reduced, so that changes in the rotational speed of the cam and the plate cylinder can be prevented.
[0025]
According to a second aspect of the present invention, in the first aspect of the present invention, the printing pressure generating means includes a first link having one end pivotably connected to the movable body, and one end pivotable at a fixed position. At the connection point between the first link and the second link, and the other end of the first link rotatably connected to the other end of the first link. One end is locked, and the first link and the second link are constituted by a spring that urges the first link and the second link in a direction in which the angle between both is increased.
[0026]
Therefore, the urging force of the spring acts on the connection point between the first link and the second link, and this force urges the first link and the second link in the direction in which the angle between them is increased. The angle between the first link and the second link when the pressing body is displaced to the retracted position together with the movable body by the protrusion of the cam, or when the pressing body or the movable body is held by the locking means at the retracted position. Is maintained at a narrow angle for comparison. In the process in which the pressing body advances to the plate cylinder side together with the movable body, the first link and the second link are displaced in the direction in which the angle expands due to the biasing force of the spring. Can be pressed against the plate cylinder. Further, by selecting the opening angle of the first and second links, the urging force of the pressing body in the plate cylinder direction can be set to an arbitrary value.
[0027]
According to a third aspect of the present invention, in the second aspect of the invention, the first link has the function of the movable body according to the first aspect of the invention, which rotatably supports the pressing body.
[0028]
Therefore, the pressing body can be supported using the first link constituting the printing pressure generating means.
[0029]
According to a fourth aspect of the present invention, in the first to third aspects of the present invention, the printing pressure generating means is disposed at both ends in the axial direction of the plate cylinder to form a pair, and the strength of the spring is adjustable. It is.
[0030]
Therefore, it is possible to perform adjustment so that the press roller is uniformly pressed against the plate cylinder over the entire axial direction.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described with reference to FIGS. The same parts as those described in FIG. FIG. 1 is a longitudinal sectional front view showing a schematic configuration of the printing apparatus in a state where the press roller 18 is retracted from the plate cylinder 1, and FIG. 2 shows a schematic configuration of the printing apparatus in a state where the press roller 18 is pressed against the plate cylinder 1. FIG. 3 is a side view showing a schematic configuration of the printing pressure generating means.
[0032]
A press roller 18 as a pressing body is provided below the plate cylinder 1. The press roller 18 has a shaft 20 protruding from both ends rotatably supported by a pair of roller arms 22 as a movable body. These roller arms 22 are supported by a support shaft 23 provided on a side plate of the printing apparatus so as to be rotatable in the vertical direction.
[0033]
A cam 17 is formed integrally with each flange of the plate cylinder 1 at both ends. This cam 17 is the same as the cam 17 described in FIG. In addition, a cam follower 21 is provided on the shaft 20 protruding from both ends of the press roller 18 so as to abut on the protrusion 17a and the inclined surface 17b of the cam 17. The cam follower 21 in the present embodiment is formed of an elastic material.
[0034]
A locking means 24 is provided that holds the roller arm 22 in a locked state at the retracted position when not printing, and releases the locked state with the roller arm 22 prior to printing. The configuration of the locking means 24 is the same as the configuration described in FIG. The only difference is that the locking lever 26 locks the pin 22 a planted on the side surface of the roller arm 22.
[0035]
Next, the configuration of the printing pressure generating means 28 that is a feature of the present invention will be described. This printing pressure generating means 28 has a property of urging the roller arm 22 by increasing the urging force of the press roller 18 to the plate cylinder 1 as the press roller 18 moves toward the plate cylinder 1.
[0036]
Specifically, the printing pressure generating means 28 includes a first link 30 having one end rotatably connected to the roller arm 22 by a shaft 29, and a shaft having one end supported at a fixed position on a side plate or the like of the printing apparatus. A second link 33 rotatably supported by 31 and having the other end pivotally connected to the other end of the first link 30 by a shaft 32 in a "<"shape; A connection point with the second link 33, that is, a spring (tensile coil spring) 34 that is locked at one end to the shaft 32 and urges the first link 30 and the second link 33 in a direction in which the angle between both is increased. It is comprised by.
[0037]
The printing pressure generating means 28 causes the urging force of the spring 34 to act on the connection point (the shaft 32) between the first link 30 and the second link 33, so that the first link 30 and the second link 33. The press roller 18 is displaced to the retracted position together with the roller arm 22 by the protrusion 17a of the cam 17, and the roller arm 22 as shown in FIG. Is held at the retracted position by the locking lever 26, the angle between the first link 30 and the second link 33 is maintained at a narrow angle for comparison. The state in which the press roller 18 and the roller arm 22 are located at the retracted position is a component force generated by the urging force of the spring 34, that is, the force that pushes the roller arm 22 upward by the first link 30, and the second link 33. The force that presses the shaft 31 is weak for comparison. This is because the angles of the first and second links 30 and 33 are narrow.
[0038]
As shown in FIG. 2, in the process in which the roller arm 22 and the locking lever 26 are unlocked and the press roller 18 advances to the plate cylinder 1 side together with the roller arm 22, the first force is applied by the urging force of the spring 34. Since the link 30 and the second link 33 are displaced in the direction in which the angle between them is increased, the press roller 18 is brought into pressure contact with the plate cylinder 1 with a strong biasing force by the toggle action. At this time, the component force generated from the urging force of the spring 34, that is, the force that pushes the roller arm 22 upward by the first link 30 and the force that the second link 33 presses the shaft 31 are the same as in FIG. Is also strong. This is because the angles of the first and second links 30 and 33 are wide.
[0039]
As will be understood from the above description, the printing pressure generating means 28 increases the urging force of the press roller 18 to the plate cylinder 1 as the press roller 18 moves toward the plate cylinder 1 so that the roller arm 22 moves toward the plate cylinder 1 side. Energize.
[0040]
Other configurations are the same as those described with reference to FIG.
[0041]
In such a configuration, when an original is set on the scanner and the plate making start key on the operation panel is pressed, the original is read, the used master on the plate cylinder 1 is collected, the master 3 is made, and the plate cylinder 1 is loaded. Various operations such as feeding of the master 3, winding of the master 3 around the plate cylinder 1, and feeding of the printing paper S (see FIG. 2) are performed. Since these operations are the same as those described above, description thereof will be omitted.
[0042]
When the registration roller 19 rotates in synchronization with the rotational movement of the plate cylinder 1 under the control of a conveyance drive unit (not shown), the printing paper S is sent out toward the plate cylinder 1. When the sheet passes between the plate cylinder 1 and the press roller 18, a sensor (not shown) provided in the passage path outputs a passage detection signal, so that the solenoid 27 is excited by using the signal as a trigger, and the locking lever. 26 rotates clockwise about the support shaft 25 and disengages from the pin 22a of the roller arm 22. Therefore, the roller arm 22 rotates clockwise about the support shaft 23 by the biasing force of the printing pressure generating means 28. . As a result, the press roller 18 presses the printing paper S against the master 3 on the plate cylinder 1. The press roller 18 rotates following the rotation of the plate cylinder 1. As a result, the ink in the plate cylinder 1 oozes out from the perforations of the master 3 and is transferred to the paper. That is, printing is performed.
[0043]
During printing, the solenoid 27 continues to be excited, and the locking lever 26 releases the roller arm 22, so that the press roller 18 contacts and separates from the plate cylinder 1 by the cam 17 that rotates integrally with the plate cylinder 1. That is, when the cam follower 21 of the press roller 18 is pressed by the protrusion 17 a of the cam 17, the roller arm 22 resists the urging force of the printing pressure generating means 28 to the retreat position where it is retracted from the plate cylinder 1 together with the press roller 18. Thus, it rotates counterclockwise around the support shaft 23. In this case, since the protrusion 17a is arranged corresponding to the position of the clamper 15, the press roller 18 is retracted downward only when the clamper 15 passes directly above it, so as to avoid interference with the clamper 15. When continuously printing, the roller arm 22 is kept in the released state, and when the clamper 15 passes just above the press roller 18, that is, above the cam follower 21, the protrusion 17 a of the cam 17 passes. At this time, the roller arm 22 is again rotated clockwise by the urging force of the printing pressure generating means 28, so that the press roller 18 presses the printing paper S against the master 3 on the plate cylinder 1.
[0044]
When the cam follower 21 is displaced to the retracted position by the protrusion 17a of the cam 17, the pin 22a is positioned slightly below the tip of the locking lever 26. Therefore, when printing is not performed subsequently, the protrusion 17a is the cam follower. By deactivating the solenoid 27 within the period during which the pressure 21 is being pressed, the locking lever 26 is locked to the pin 22a, and the roller arm 22 is held in the retracted position.
[0045]
As described above, the printing pressure generating means 28 increases the urging force of the press roller 18 to the plate cylinder 1 as the press roller 18 moves toward the plate cylinder 1 and urges the roller arm 22 toward the plate cylinder 1 side. Therefore, in the process in which the press roller 18 advances to the plate cylinder 1 side together with the roller arm 22, the urging force of the printing pressure generating means 28 is weak, so that the collision noise between the cam 17 and the cam follower 21 of the press roller 18 is reduced. In addition, since the cam follower 21 is formed of an elastic material, the collision sound can be further reduced.
[0046]
Further, when the cam follower 21 of the press roller 18 abuts against the protrusion 17 a of the cam 17, the upward biasing force of the first link 30 is weak, so that the load on the motor that drives the plate cylinder 1 together with the cam 17 is reduced. It is not necessary to make the support structure of the rotational drive system stronger than necessary.
[0047]
Further, in the process in which the press roller 18 advances to the plate cylinder 1 side together with the roller arm 22, the printing paper S is transferred to the master 3 on the plate cylinder 1 rotating in the clockwise direction by the press roller 18 with the movement in the rotation direction stopped. Is pressed against the master 3, and as a result, the master 3 is pulled in a direction opposite to the rotation direction of the plate cylinder 1. Accordingly, before the press roller 18 presses the printing paper S against the master 3 on the plate cylinder 1, the cam follower 21 comes into contact with the protrusion 17a of the cam 17, and the counter roller and the press roller 18 are counterclockwise due to friction of the contact portion. Since it rotates in the direction, the master 3 is not pulled in the direction opposite to the direction of rotation of the plate cylinder 1.
[0048]
On the other hand, when the press roller 18 presses the printing paper S against the master 3 on the plate cylinder 1, the opening angle of the first and second links 30 and 33 is large as described above, and the first link The urging force that 30 pushes up the roller arm 22 is the strongest in a range suitable for ink bleeding, but when the press roller 18 is pressed by the projection 17a of the cam 17 and retracts from the plate cylinder 1 together with the roller arm 22, Since the opening angle of the first and second links 30 and 33 is narrowed and the urging force that pushes the roller arm 22 down by the first link 30 is weakened, the torque received by the protrusion 17a of the cam 17 from the cam follower 21 of the press roller 18 Therefore, a change in the rotational speed of the cam 17 and the plate cylinder 1 can be prevented. Thereby, the registration position shift of the master 3 on the plate cylinder 1 can be prevented, and the shift of the image printing position with respect to the printing paper S can be prevented.
[0049]
Further, the printing pressure generating means 28 selects the opening angles of the first and second links 30 and 33 when the press roller 18 presses the printing paper S against the master 3 on the plate cylinder 1, The urging force of the press roller 18 toward the plate cylinder 1 can be set to an arbitrary value. By increasing the urging force by this method, it is possible to print neatly even on embossed paper with poor ink filling or printing paper S with coarse mesh.
[0050]
Further, the printing pressure generating means 28 is disposed at both ends in the axial direction of the plate cylinder 1 and forms a pair. By adjusting the strength of the spring 34, the press roller 18 is spread over the entire area in the axial direction. It is possible to perform adjustment so as to press the plate cylinder 1 uniformly. As a method of changing the strength of the spring 34, there is a method of changing the spring 34 itself, or a method of providing a support member (not shown) for supporting one end of the spring 34 so that its position can be adjusted in the tension direction of the spring 34. It is done. The spring 34 is not limited to the tension coil spring, and a compression spring may be used. When using a compression spring, in FIG.1 and FIG.2, it arrange | positions so that the connection point (shaft 32) of the 1st, 2nd links 30 and 33 may be pressed toward the right side from the left side.
[0051]
Although the pin 22a of the roller arm 22 is configured to be held by the locking lever 26 of the locking means 24, the shaft 20 of the press roller 18 may be held by the locking lever 26.
[0052]
Further, as the movable body, the roller arm 22 that swings and pivots around the support shaft 23 is used. However, the movable body that rotatably supports the press roller 18 is linearly moved toward and away from the plate cylinder 1. It may be displaced.
[0053]
Next, a second embodiment of the present invention will be described with reference to FIGS. The same parts as those of the first embodiment are denoted by the same reference numerals, and description thereof is also omitted. FIG. 4 is a partial longitudinal sectional front view showing a schematic configuration of the printing apparatus in a state where the press roller 18 is retracted from the plate cylinder 1, and FIG. 5 is an outline of the printing apparatus in a state where the press roller 18 is pressed against the plate cylinder 1. It is a partial vertical front view which shows a structure.
[0054]
This embodiment is an example in which the first link 30 in the above embodiment has a function of a roller arm as a movable body that rotatably supports a press roller 18 as a pressing body.
[0055]
In this case, in order to hold the first link 30 serving also as a movable body in the retracted position together with the press roller 18, a pin 30 a is implanted on the side surface of the first link 30, and the pin 30 a is moved by the locking lever 26. You may comprise so that it may hold | maintain, and you may comprise so that the axis | shaft 20 of the press roller 18 may be hold | maintained by the latching lever 26. FIG.
[0056]
Thus, the number of parts can be reduced by supporting the press roller 18 using the first link 30 constituting the printing pressure generating means 28.
[0057]
【The invention's effect】
According to the first aspect of the present invention, there is provided a plate cylinder having a master holding clamper at a part of the outer periphery, a displaceable movable body that supports a pressing body that presses the printing paper against the master on the plate cylinder, and the clamper presses A cam with a protrusion formed on a part of the outer periphery that displaces the pressing body together with the movable body to the retracted position at the timing facing the body, and the movable body or the pressing body is held in a locked state when not printing. And a locking means for releasing the locked state with the movable body or the pressing body prior to printing, and the urging force of the pressing body to the plate cylinder is made stronger as the pressing body moves toward the plate cylinder. Is provided with a printing pressure generating means for urging the pressure, so that when the pressing body advances to the plate cylinder side together with the movable body, the urging force of the printing pressure generating means is weak, so the impact sound with the cam can be reduced, When the body is pressing the printing paper against the master on the plate cylinder, The urging force of the generating means is the strongest, and when the pressing body is retracted from the plate cylinder together with the movable body, the urging force of the printing pressure generating means is weakened, so the torque received by the cam protrusion from the pressing body or the movable body is reduced, Changes in the rotational speed of the cam and the plate cylinder can be prevented, thereby preventing the registration position shift of the master on the plate cylinder and the printing position shift of the image with respect to the printing paper.
[0058]
According to a second aspect of the present invention, in the first aspect of the present invention, the printing pressure generating means includes a first link having one end rotatably connected to the movable body, and one end rotatably supported at a fixed position. The other end of the first link is pivotally connected to the other end of the first link in the shape of a "<", and one end is locked to the connection point between the first link and the second link. The first link and the second link are configured by a spring that urges the two links in a direction in which the angle between the first link and the second link increases. And the pressing body can be pressed against the plate cylinder by the urging force. Further, by selecting the opening angle of the first and second links, the urging force of the pressing body in the plate cylinder direction can be set to an arbitrary value.
[0059]
The invention according to claim 3 is the invention according to claim 2, wherein the first link has the function of the movable body according to claim 1 which rotatably supports the pressing body, and thus constitutes the printing pressure generating means. The pressing body can be supported using the first link, whereby the number of parts can be reduced.
[0060]
According to a fourth aspect of the present invention, in the first to third aspects of the present invention, the printing pressure generating means is disposed at both ends in the axial direction of the plate cylinder to form a pair, and the strength of the spring is adjustable. The press roller can be adjusted to be uniformly pressed against the plate cylinder over the entire axial direction.
[Brief description of the drawings]
FIG. 1 is a longitudinal front view showing a schematic configuration of a printing apparatus in a state where a press roller is retracted from a plate cylinder according to a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional front view showing a schematic configuration of a printing apparatus in a state where a press roller is pressed against a plate cylinder.
FIG. 3 is a side view showing a schematic configuration of printing pressure generating means.
FIG. 4 is a partial longitudinal front view showing a schematic configuration of a printing apparatus in a state in which a press roller is retracted from a plate cylinder according to a second embodiment of the present invention.
FIG. 5 is a partial longitudinal front view showing a schematic configuration of a printing apparatus in a state where a press roller is pressed against a plate cylinder.
FIG. 6 is a longitudinal front view showing a schematic configuration of a conventional printing apparatus.
[Explanation of symbols]
1 plate cylinder
3 Master
15 Clamper
17 cams
17a protrusion
18 Pressing body
22 Movable body
24 Locking means
28 Printing pressure generating means
30 First link
32 connecting points
33 Second link
34 Spring
S printing paper

Claims (4)

A plate cylinder that is rotationally driven with a clamper that holds the edge of the master made as a part of the outer periphery;
A displaceable movable body that rotatably supports a pressing body that presses the printing paper against the master on the plate cylinder;
A protrusion that displaces the pressing body together with the movable body to a retracted position for retracting from the plate cylinder at a timing when the clamper faces the pressing body is formed on a part of the outer periphery, and is synchronized with the rotational movement of the plate cylinder. A rotating cam,
Locking means for holding the movable body or the pressing body in a locked state at the retracted position at the time of non-printing and releasing the locked state with the movable body or the pressing body prior to printing;
A printing pressure generating means for urging the movable body by energizing the pressing body to the plate cylinder, and increasing the pressing body toward the plate cylinder;
A printing apparatus comprising: The printing pressure generating means includes a first link having one end rotatably connected to the movable body, one end rotatably supported at a fixed position, and the other end connected to the other end of the first link. A second link that is pivotably connected to the shape of the "ku", and one end of the second link that is locked to a connection point between the first link and the second link. The printing apparatus according to claim 1, wherein the printing apparatus is configured by a spring that urges the link in a direction in which the angle of both increases. The printing apparatus according to claim 2, wherein the first link has a function of a movable body according to claim 1 that rotatably supports the pressing body. 4. The printing apparatus according to claim 1, wherein the printing pressure generating means is disposed on both ends in the axial direction of the plate cylinder to form a pair, and the strength of the spring is adjustable. 5.

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