JPH0848067A - Clamping device of master of stencil printing equipment - Google Patents

Abstract

PURPOSE:To provide a clamping device of the master of a stencil printing equipment, by which no wrinkle develops even when the master laminated with a porous support, the master having a thin porous support or the master made of a single film having no support is employed. CONSTITUTION:A clamping device 100 of the master of a stencil printing equipment is equipped with a clamper 7, both of the end parts 7a and 7b of which are supported by fulcrum shafts 14A and 14B, which are pivotally provided parallel to a stage 6 extending along one generatrix of the outer peripheral surface 1A of a porous cylindrical form cylinder 1 so as to allow to selectively occupy a sucking position, at which the clamper is magnetically sucked to the stage 6, and a separate position, at which the clamper is separated from the stage 6 in order to pinch the tip 8a of a justified master 8 when the clamper occupies its sucking position. Accordingly, the clamper 7 is made of a nearly band-like elastic body, which takes the shape curved so as for the central part 7c of the clamper 7 to keep apart from the stage 6 when the clamper occupies its separate position. Further, a magnet 7B is provided at least at the central part 7c or at the region, which is opposite to the central part, of the stage 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a master clamp device for a stencil printing machine.

[0002]

2. Description of the Related Art A master for heat-sensitive stencil printing used in a stencil printing machine is a very thin thermoplastic resin film such as polyester (hereinafter referred to simply as "film") and a porous flexible support. As the laminated structure, a synthetic fiber such as polyethylene terephthalate resin (PET) excellent in insulation and heat resistance, Japanese paper, or a mixture of Japanese paper and synthetic fiber is laminated. For this master, the stencil printing machine performs perforation plate making on the film portion by a heating element such as a thermal head, and automatically conveys the master to automatically wind it around the outer peripheral surface of the porous cylindrical plate cylinder. The printing paper is continuously pressed against the master by a pressing means such as a press roller, and the plate is formed by an ink supply member arranged inside the plate cylinder through an opening provided in the plate cylinder and a punched portion of the master. Printing is performed by allowing the printing ink supplied to the inner peripheral surface of the body to seep out.

Since the master used in the above-mentioned application uses Japanese paper or the like as its support, the passage of the ink is obstructed at the portion where the fibers of the Japanese paper are entangled with each other, and the ink is not transferred to the printing paper, and the solid portion is formed. The problem of the so-called fiber grain, in which a fiber pattern appears or thin lines are faint, occurs. Therefore, it is possible to prevent the generation of fiber grain by printing with a master consisting of only a film without using Japanese paper as a support, but the thickness of the film itself is about 1 to 1. It is about 2 μm, which is about 20 of the thickness of the Washi Laminate Master, which is about 40 to 50 μm.
It is very thin, about one-third, and the film material itself is a high insulator, so it is easy to be charged with static electricity, and jams or the like frequently occur when it is wrapped around or stuck to the transport roller,
There is a problem that the clamp property of the master tip part is deteriorated.

Conventionally, there is no full-scale technique for solving the above-mentioned inconvenience, but, for example, as disclosed in Japanese Utility Model Publication No. 1-26463, a clamper (clamp piece) is used.
And a stage part that sandwiches and joins a headless print master that does not have a reinforcing paper piece part to it is selectively magnetically attracted, and the magnetic attraction force causes the clamper (clamp piece) and the stage part to A method has been proposed in which the printing master is sandwiched between the printing master and the printing master is locked to the printing plate cylinder.

[0005]

However, in the prior art, when the master has a strong waist, the clamper moves down when it is held by the clamper because it has a waist even if it is conveyed in a slightly wavy state. When stretched, the slack was gradually relaxed and absorbed when it was wound around the plate cylinder, and wrinkles and the like were prevented from occurring. However, if the master is weak like a master consisting of only a single film, the strength of both sides will be lower than that of the center of the master, so that both ends will hang down more easily than the center, resulting in a semi-cylindrical (inverted U shape). Since it is conveyed in a letter shape and both ends hang down, it is delayed as compared with the central portion, and there is a problem that vertical wrinkles and horizontal wrinkles occur when winding without being clamped flat when clamped.

Further, in the clamper of an elastic member described in Japanese Utility Model Publication No. 1-26463, which is pivotally supported on the left and right sides, the central portion of the clamper bends downwardly toward the stage side due to magnetic force. When the master is held by the clamper (when the master is rotated in the closing direction), the central portion of the master comes into contact with the stage portion. In this way, when the clamper rotates and contacts the stage from the center of the clamper, the center of the master ear is clamped while being moved by the inner end of the clamper toward the pivot side. Therefore, since only the central part of the master is extended in the moving direction, clamp wrinkles were likely to occur.

The master porous support may be thinned for the purpose of reducing or preventing the number of fibers and improving the image quality, but in this case also, the strength and stiffness of the master itself is weak and waviness or the like occurs. However, the clamp becomes unstable and wrinkles occur in the master. Therefore, the present invention is a master in which a conventional porous support and film have a laminated structure, and
An object of the present invention is to provide a master clamp device that can suppress the generation of wrinkles even if a master having a thin porous support or no porous support is used.

[0008]

A stage extending along one generatrix of an outer peripheral surface of a porous cylindrical plate cylinder according to claim 1, and a stage on the outer peripheral surface of the plate cylinder in parallel with the stage. The support shaft provided and both end portions of the support shaft are selectively supported by a suction position magnetically attracted to the stage and a separation position separated from the stage. In a master clamp device of a stencil printing apparatus that includes a clamper that holds a prepressed master between the stage and the stage, the clamper has a curved shape in which a central portion thereof is away from the stage when the separated position is occupied. Is formed of a substantially strip-shaped elastic body, and a magnet is arranged at least at the central portion or at a portion of the stage facing the central portion. A stage extending along one generatrix of the outer peripheral surface of the porous cylindrical plate cylinder according to claim 2, a spindle provided on the outer peripheral surface of the plate cylinder in parallel with the stage, and the support. The central portion is supported by the shaft, and selectively occupies a suction position magnetically attracted to the stage and a separation position spaced from the stage, and when the suction position is occupied, a plate-making master is provided between the stage and the stage. In a master clamp device of a stencil printing apparatus including a clamper that holds the clamper, the clamper is formed of a substantially strip-shaped elastic body whose suction surface forms a planar shape when the separated position is occupied, and both ends thereof are A magnet is disposed so as to be displaceable toward the stage, and at least at the both end portions or at a portion of the stage facing the both end portions.

[0009]

According to the first aspect of the present invention, the clamper which selectively rotates between the attracting position magnetically attracted to the stage and the separated position separated from the stage is provided at the center of the clamper when the separated position is occupied. Since the part is formed of a substantially strip-shaped elastic body that is curved in a direction away from the stage, and the magnet is arranged at least in the central part or at the part of the stage facing the central part, the clamper moves from the separated position to the attracted position. When it is turned toward, both ends thereof come into contact with the master on the stage first, and thereafter, the curved central portion is magnetically attracted to the stage side and is displaced toward the same stage toward the same stage. Due to this displacement of the central portion, both ends move in the extending direction of the stage parallel to the support shaft, and tension is applied in the extending direction of the stage to the master sandwiched by the clamper and the stage. According to the second aspect of the present invention, the clamper that selectively rotates between the magnetically attracted position on the stage and the separated position separated from the stage has a flat attracting surface when the separated position is occupied. The clamper is made of a substantially band-shaped elastic body, and both ends of the elastic body can be displaced toward the stage, and the magnets are arranged at least at both ends or at the stage part facing the both ends, so that the clamper is at the separated position. When it is rotated to the suction position, the both ends are magnetically displaced to the stage side parallel to the support shaft during the rotation process and come into contact with the master on the stage before the central part, and the master rotates the clamper. It is pulled toward the center. When both ends of the clamper come into contact with the master on the stage, the center part supported by the support shaft is pushed and displaced toward the stage by the turning force of the clamper, and both ends move in the extension direction of the stage. , A tension is applied to the master in the extending direction of the stage.

[0010]

First, a stencil printing machine in which the first embodiment of the present invention is implemented will be described. A stencil printing machine indicated by reference numeral 200 in FIG. 1 has a plate cylinder 1 having a porous cylindrical shape. The plate cylinder 1 has a configuration including a porous support cylinder and a mesh screen of resin or metal mesh wound so as to cover the surface thereof. The plate cylinder 1 is rotatably supported by a rotation center shaft 5 that also serves as an ink pipe, and is rotationally driven in the direction of arrow A by a motor (not shown). An ink roller 2 rotatably supported by a side plate (not shown) is arranged inside the plate cylinder 1.

The ink roller 2 can be rotationally driven in the same direction in synchronism with the plate cylinder 1 by drive transmission means composed of gears, belts and the like (not shown). In the vicinity of the ink roller 2, a doctor roller 3 is arranged at a slight distance from the outer peripheral surface 2A thereof. In a wedge-shaped space formed by the ink roller 2 and the doctor roller 3, an ink reservoir 4 to which printing ink is supplied from an ink pipe (5) is formed, and the printing ink in this ink reservoir 4 is the outer periphery of the ink roller 2. It is supplied to the surface 2A and then supplied to the inner peripheral surface 1B of the plate cylinder. In the vicinity of the lower side of the outer peripheral surface 1A of the plate cylinder 1 facing the ink roller 2, a contact position indicated by a solid line and a separated position indicated by a chain double-dashed line with respect to the plate cylinder 1 that presses the printing paper S against the plate cylinder 1 A press roller 17 which is rocked by a rocking means (not shown) is arranged.

On the left side of the plate cylinder 1, a master roll 8A, around which a master 8 (hereinafter simply referred to as "master 8") consisting essentially of a thermoplastic resin film is wound, is rotated by holder means (not shown). Roll core 8B supported freely
Supported by. The master 8 is pressed against a platen roller 9 rotatably supported by a side plate (not shown) by a thermal head 10 having a heating element, and is rotated in the direction of arrow B from a master roll 8A by the rotation of the platen roller 9. It goes to the plate cylinder 1. The master 8 is perforated while passing between the platen roller 9 and the thermal head 10 to form a perforated image. Between the platen roller 9 and the plate cylinder 1 located on the downstream side in the master transport direction, feed rollers 11A and 11B that are rotatable in a state of being pressed against each other and a fixed blade 12a that cuts the master 8 to an appropriate length are provided. And a movable blade 12b, and the tip 8a of the master 8 is connected to the stage 6 and the clamper 7.
And a guide plate 13 for guiding between the two. These platen roller 9, thermal head 10, feed rollers 11A and 11B, and cutter device 12 constitute a plate making means. The feed rollers 11A, 11
B has its peripheral speed rotated slightly faster than the peripheral speed of the platen roller 9, and prevents the master 8 from being loosened between the feed rollers 11A and 11B and the platen roller 9.

The master clamp device 100 is provided with a stage 6 provided on the outer peripheral surface 1A of the plate cylinder 1 and a clamper 7 for clamping the leading end 8a of a master 8 which is conveyed together with the stage 6. The stage 6 is made of a magnetic material, and as shown in FIG.
It is installed along two busbars. On the hinges 6a and 6b formed at both ends of the stage 6, support shafts 14A and 14B which are parallel to the stage 6 are supported so as to be rotatable and slidable, respectively. As shown in FIG.
As shown in FIG. 3, the clamper 7 is supported with a space L between the clampers 7 and the hinges 6a and 6b. Each interval L is
The displacement amounts Δa of both end portions 7a and 7b of the clamper 7, which will be described later, are set to be respectively larger.

The clamper 7 is fixed to a support shaft 14A and a support shaft 14B, respectively, to which gears 15 for connecting both ends 7a and 7b to an opening / closing device (not shown) are fixed. It is openable / closable between the contacting suction position and the separation position separated from the stage 6. As shown in FIG. 3 and FIG. 4, the clamper 7 has a substantially belt-like planar shape, and is shaped in such a manner that its central portion 7c is curved in a direction away from the stage 6 when it occupies the separated position. 7a and 7b are flat surfaces that are continuous with the curvature of the central portion 7c, and when the suction position is occupied, the central portion 7c is deformed toward the stage 6 and adheres to the stage 6, and both end portions 7a and 7b are Each is designed to move in the axial direction. Further, the coil springs 16 are provided between the both ends 7a, 7b and the hinges 6a, 6b, respectively.
a and 16b are wound around the support shafts 14A and 14B, and the clamper 7 is urged from both sides toward the center by the spring force of the coil springs 16a and 16b.

More specifically, the clamper 7 has a thin elastic support plate 7A which is curved at the center and flattened at both ends so that the curved portion faces the surface facing the stage 6 so as to follow the curved portion. The rubber magnet 7B is provided on the surface of the two ends 7a and 7b, and a magnetic member 7C having a larger frictional resistance than the upper surface of the stage 6, for example, a rubber magnet is disposed on the surface facing the stage 6 in the double structure. Support plate 7
A may be any material having elasticity, and in this embodiment,
A thin metal plate of about 0.5 to 1 mm is used. In addition to this, as a material suitable for the support plate 7A, a thickness of 0.5 to
Examples of the plastic include vinyl chloride having a size of about 1 mm. The curvature rate of the central portion 7c of the clamper 7 is such that the distance Δd from the end bottom surface 7D forming a part of the attracting surface to the maximum curved portion 7E on the inner curved surface of the rubber magnet 7B is in a curvature range of about 2 mm to 5 mm. It is set.

The operations of the stencil printing apparatus 200 and the master clamp apparatus 100 having the above-mentioned configurations will be described. In the stencil printing apparatus 200, when a document is set on a document reading unit (not shown) and the start button is pressed, the plate cylinder 1 is rotated, and the used old plate is rotated by the plate discharge device (not shown).
The outer peripheral surface 1A is peeled off and discarded. Next, plate cylinder 1
Rotates to move the master clamp device 100 to a position which is a predetermined plate feeding position substantially directly above the plate cylinder 1 and stops, and the clamper 7 is opened to enter the plate feeding standby state. When the document is sent to a document reading unit (not shown), the read document image is converted into electrical image information by a CCD (not shown), an A / D converter, a plate-making control device, etc., and based on the information, the thermal head 10 The heating element generates heat, and the platen roller 9 and the feed rollers 11A and 11
B is rotatably driven by a stepping motor (not shown) to carry the master 8 while carrying out plate making. The tip 8a of the master 8 that has been plate-making is guided to the master clamp device 100 by the guide plate 13.

When it is judged that the tip 8a of the master 8 has reached between the stage 6 and the clamper 7 constituting the master clamp device 100, for example, is judged by the step number of a stepping motor (not shown), an opening / closing mechanism (not shown) is used. The clamper 7 rotates toward the suction position to clamp the leading end 8a of the master 8 and the plate cylinder 1 is re-driven in the clockwise direction at a speed substantially the same as the transport speed of the master 8, so that the master 8 made as a plate It begins to be wound around the outer peripheral surface 1A of the body 1. When it is determined that the master 8 made on the plate cylinder 1 has been wound around the plate cylinder 1 for a predetermined length according to the number of steps of the stepping motor, the plate cylinder 1, the platen roller 9 and the feed rollers 11A and 11B are stopped from rotating and the cutter device is also provided. 12, the master 8 is cut off, and then the plate cylinder 1 rotates clockwise again,
The cut master 8 is completely wound around the outer peripheral surface 1A of the plate cylinder 1.

When the master 8 is wrapped around the plate cylinder 1,
One sheet of printing paper S is inserted between the plate cylinder 1 and the press roller 17 at a predetermined timing synchronized with the rotation of the plate cylinder 1 by a paper feeding device (not shown). Then, the outer peripheral surface 1 of the plate cylinder 1
The press roller 17 separated from A swings upward, and the print sheet S is pressed by the plate-made master 8 wound around the outer peripheral surface 1A of the plate cylinder 1 rotating in the clockwise direction to form the plate. Ink is transferred from the perforated portion of the master 8 to the surface of the printing paper S and printed. At this time, the ink roller 2 also rotates in the same direction as the rotation direction of the plate cylinder 1 to supply the printing ink to the inner peripheral surface 1B of the plate cylinder 1. The printed printing paper S is printed on the outer peripheral surface 1 of the plate cylinder 1 by a peeling nail (not shown).
It is peeled from A and discharged to a paper discharge tray (not shown) arranged on the left side of the press roller 17,
Swings to the separated position and enters a print standby state.

(Operation of Master Clamp Device 100) The tip 8a of the master 8 that has been plate-made is the master clamp device 100.
When it reaches between the stage 6 and the clamper 7 constituting the above, the clamper 7 is rotated toward the suction position by an opening / closing mechanism (not shown), and as shown in FIG.
The lower surface of the magnetic member 7C provided on the
When contacted with 8c, the rubber magnet 7B, which is curvedly provided so as to project to the side away from the stage 6 in the central portion 7c, is directed downward in the drawing in order to attract the stage 6 composed of a magnetic body by its own magnetic force. Will be displaced. Central part 7c
5B, both ends 7a and 7b of the clamper 7 are moved by Δa in the extending direction of the stage 6 shown by the arrow (see FIG. 3), and both edges 8 are deformed.
Both end edges 8b, 8 of the master 8 in which the b, 8c hang down to form a kamaboko shape (inverted U shape) and are conveyed onto the stage 6.
Tension is applied to c in the direction of the arrow, and the tip 8a of the master 8 that has been plate-made is clamped between the stage 6 and the clamper 7 while curving the wrinkle in the width direction of the master 8.

As described above, according to the first embodiment, both ends 7a and 7b of the curved clamper 7 are first brought into contact with the master 8 on the stage 6 during the clamper closing operation of the master 8 which has been prepressed. Since the clamper 7 itself is elastically deformed while the entire clamper 7 is pressed against the stage 6, the positions of both end portions 7a and 7b of the clamper 7 are respectively moved in the extending direction of the stage 6, and the plate-making process is completed. The master 8 can be clamped while applying tension to both ends 8b and 8c to move the stage 6 in the extending direction. Therefore,
The master 8 that has been plate-made has both edges 8 of the master 8 during transportation.
Even if b and 8c hang down and are transported in the shape of a kamaboko as described above, they will be corrected during the clamping operation.
Wrinkles and the like are prevented from being generated when the plate cylinder 1 is wound.

Next, a second embodiment of the present invention will be described. The same reference numerals as those used in the first embodiment are given to the members having the same construction and the same function as those in the first embodiment. The description is omitted. In the second embodiment, as shown in FIGS. 6 and 7, the central portion 70c of the clamper 70 is fixed to one support shaft 140 rotatably supported by the hinges 6a and 6b, and the clamper 70 is at the separated position. The entire bottom surface 70D of the clamper 70 that constitutes the suction surface when occupying is formed from a substantially belt-shaped elastic body having a planar shape, and its both end portions 70a, 7
It is characterized in that 0b is composed of a magnet and can be displaced toward the stage 6.

The clamper 70 is a thin, strip-shaped elastically deformable support plate 70A, and both ends 70a and 70b of the support plate 70A are flat plate-shaped rubber magnets 70B having a larger friction resistance than the upper surface of the stage 6.
And the rubber magnets 7 at both ends 70a and 70b are arranged in the center.
The magnetic member 70C has a V-groove L1 between each
Has a double structure. Normally, when the clamper 7 is at the separated position away from the stage 6, the bottom surface 70D serving as the suction surface of the clamper 7 has a planar shape due to the tension of the support plate 70A, and is rotated to the vicinity of the suction position. Then, both ends 70a and 70b are deformed in a V-shape when viewed from the front toward the stage 6 by the attracting action of the rubber magnets 70B provided at both ends 70a and 70b. The amount of movement of the clamper 70 in the axial direction due to the deformation of the both end portions 70a and 70b is Δ
b. The clamper 70 has both ends 70a and 70b.
Is set so that the distance between the stage 6 and the bottom surface 70D when it is displaced is Δd ′. Here, Δd ′ is about 2 mm to 5 mm.

According to the master clamp device 100 'having the clamper 70 having such a structure, when the front end 8a of the master 8 made by plate-making reaches between the stage 6 and the clamper 70 constituting the master clamp device 100', it is shown in the drawing. It is rotated toward the stage from the separated position shown in FIG. 9A by the opening / closing mechanism. Then, when approaching the vicinity of the stage 6, first, as shown in FIG.
70b is deformed toward the stage 6 by the attracting action of the magnetic force of the rubber magnet 70B, and comes into contact with both end edges 8b and 8c of the tip 8a of the master 8 on the stage 6 before the central portion 70c. Then, the clamper 70 approaches the stage 6 while rotating, as shown in FIG.
The inner ends 70d of the both end portions 70a, 70b come into contact with the both end edges 8b, 8c of the tip 8a of the master 8 by Δc before the position when the inner end 70d is in the suction position shown by the two-dot chain line, and the clamper 70 is in the suction position. When the master 8 is turned toward, the tip 8a side of the master 8 is pulled toward the support shaft 140 side, which is the center of the turning. Therefore, the wavy wrinkles that occur in the longitudinal direction of the master 8 are extended during clamping.

When the clamper 70 is further rotated in the closing direction, the central portion 70c fixed to the support shaft 140 is pressed, and the bottom surface 70D is displaced downward as shown in FIG. 9C. Then, both end portions 70a and 70b respectively move by Δb in the extending direction of the stage 6 indicated by the arrow. Therefore, the stage 6 is attached to both end edges 8b and 8c of the master 8 which is curvedly entered between the clamper 70 and the stage 6.
Since it is possible to clamp while applying a tension to move the master 8 in the extending direction, the curvature of the master 8 is corrected during the clamper operation, and wrinkles and the like when the plate cylinder 1 is wound are eliminated.
In this embodiment, the V groove L1 is provided between the magnetic member 70C and the rubber magnet 70B, but for example, the support plate 70A is used.
Is made of extremely thin steel or synthetic resin, or
When a rubber magnet 70B having a strong magnetic force is adopted and both end portions 70a and 70b of the clamper 70 are easily deformed toward the stage 6, the groove L1 is not always necessary.

In each of the above-mentioned embodiments, the rubber magnets 7B and 70B are arranged on the clampers 7 and 70 side as the attracting members, but the invention is not limited to this. In the first embodiment, the clamper 7 is curved. Central portion 7c and both end portions 7
A magnetic material is arranged in a and 7b, and the central portion 7c and both end portions 7 are arranged.
A magnet is arranged on the stage 6 facing the a and 7b, and both ends 70a and 7 of the clamper 70 are also arranged in the second embodiment.
0b and the central portion 70c are provided with magnetic bodies, and both end portions 70a,
Even if the magnets are arranged on the stage 6 facing the 70b and the central portion 70c, the clampers 7 and 70 themselves are deformed and brought into close contact with the stage 6, and the tip 8a of the master 8 to be conveyed is clamped. Good. Even with such a configuration, the same effects as those of the above-described embodiments can be obtained. Further, in each of the above-described embodiments, the support shafts 14A, 14B or the support shaft 140 is provided rotatably with respect to the stage, but the present invention is not limited to this, and for example, the support shafts 14A, 14 are provided.
B and 140 are fixed to the stage 6, and the support shafts 14A,
14B or the support shaft 140 is provided with one end of the clamper 7, 70 rotatably, and the clamper 7 or 70 is opened and closed by an opening / closing means such as an arm selectively engaged with the clamper 7 or 70. May be.

Further, in the first embodiment, the magnetic members 7C are arranged at both ends 7a and 7b of the clamper 7, and in the second embodiment, the magnetic members 70C are arranged at the central portion 70c of the clamper 70, respectively. The magnetic members 7C and 70C may be metal or resin, or may be magnets similar to the central portion 7c and both end portions 70a and 70b.
Also, a non-magnetic member may be used instead of the magnetic members 7C and 70C. However, in terms of ensuring the wrinkle-extending effect of the master 8, the end portions 7a, 7 of the clampers 7, 70 are secured.
It is preferable to arrange magnets in all of b, 70a, 70b and the central portions 7c, 70c. The master 8 used in each of the above-described examples means that the master 8 is composed of only a thermoplastic resin film, and the master 8 is composed of only a thermoplastic resin film, and the thermoplastic resin film contains trace components such as an antistatic agent. In addition, those containing one and a plurality of thin film layers such as an overcoat layer are formed on both main surfaces of the thermoplastic resin film, that is, at least one of the front surface and the back surface. The master 8 may have a laminated structure in which a porous support and a film are bonded together.

[0027]

According to the first aspect of the present invention, the central part of the clamper is curved in a direction away from the stage, and when the master is clamped, both ends of the clamper are brought into contact with both end edges of the master, and the center of the clamper is magnetically applied. By deforming the part toward the stage and moving both ends in the stage extending direction, it is possible to prevent wrinkles from being generated when the clamper is clamped.
In other words, even if a master in the shape of a kamaboko, which has both edges hanging down during transportation, can be corrected during clamping, it is possible to provide a master clamping device that is less likely to wrinkle during winding of the plate cylinder and that can be reliably locked. . According to the second aspect of the present invention, both ends of the clamper whose central portion is supported by the support shaft are deformed by magnetic force toward the stage in the vicinity of the stage and are attached to both end edges of the master on the stage before the central portion. By making contact, both ends of the master can be given tension in the direction of pulling outward of the stage, and the master can be drawn toward the center of rotation of the clamper as the clamper rotates, so that the Even if the master, which has a semi-cylindrical shape with its both edges hanging down, is conveyed, it can be corrected during clamping, it can be locked securely without wrinkling during plate cylinder winding, and the wavy wrinkles that extend in the conveying direction of the master are extended. It is possible to provide a master clamp device capable of performing the above.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a stencil printing machine to which an embodiment of the present invention is applied.

FIG. 2 is a perspective view showing a master clamp device of a stencil printing machine as a first embodiment of the present invention.

FIG. 3 is a partially cutaway enlarged perspective view of the clamper according to the first embodiment.

FIG. 4 is a partially cutaway plan view of the clamper according to the first embodiment.

5A is a sectional view showing an initial contact state between a clamper and a master in the first embodiment, and FIG. 5B is an operation diagram showing a deformed state of the clamper.

FIG. 6 is a plan view showing a second embodiment of the present invention.

FIG. 7 is a partially cutaway enlarged perspective view of a clamper according to a second embodiment.

FIG. 8 is a side view showing the operation of the master clamp device according to the second embodiment.

FIG. 9A is a front view of a clamper placed at a separation position in the second embodiment, and FIG. 9B is a cross-sectional view showing an initial contact state between the clamper and the master and a deformed state of the clamper.
(C) is a cross-sectional view showing a deformed state of the clamper.

[Explanation of symbols]

 1 plate cylinder 1A outer peripheral surface 6 stage 7,70 clamper 7a, 7b, 70a, 70b both ends 7c, 70c central part 7B, 70B magnet 8 master 14a, 14b, 140 spindle 100, 100 'master clamp device 200 stencil printer

Claims (2)

[Claims] 1. A stage extending along one generatrix of an outer peripheral surface of a plate cylinder having a porous shape, a support shaft provided on the outer peripheral surface of the plate cylinder in parallel with the stage, and the support. Both ends of the shaft are supported, and a suction position magnetically attracted to the stage and a separation position separated from the stage are selectively occupied, and when the suction position is occupied, a plate-making master is held between the stage and the stage. A master clamp device of a stencil printing apparatus comprising a clamper for sandwiching the clamper, wherein the clamper is formed of a substantially strip-shaped elastic body whose center portion is curved in a direction away from the stage when the separated position is occupied. A master clamp device for a stencil printing apparatus, wherein a magnet is provided on at least the central portion or a portion of the stage that faces the central portion. 2. A stage extending along one generatrix of an outer peripheral surface of a plate cylinder having a porous shape, a support shaft provided on the outer peripheral surface of the plate cylinder in parallel with the stage, and the support. The central portion is supported by the shaft, and selectively occupies a suction position magnetically attracted to the stage and a separation position spaced from the stage, and when the suction position is occupied, a plate-making master is provided between the stage and the stage. A master clamp device for a stencil printing apparatus, comprising a clamper for sandwiching the clamper, wherein the clamper is formed of a substantially strip-shaped elastic body whose suction surface forms a planar shape when the separated position is occupied, and both ends thereof. A master clamp device for a stencil printing apparatus, characterized in that a portion is displaceable toward the stage, and a magnet is provided at least at the both end portions or at a portion of the stage facing the both end portions.