JP4302223B2 - Stencil printing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a stencil printing apparatus provided with a press roller that can be freely contacted and separated from the outer peripheral surface of a plate cylinder.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, stencil printing apparatuses provided with a press roller that can freely come in contact with and separate from the outer peripheral surface of a plate cylinder have been known. For example, they are described in JP-A-3-136890, JP-A-8-2083, and the like. There is something. In these stencil printing apparatuses, when the clamper provided on the outer peripheral surface of the plate cylinder moves with the rotation of the plate cylinder to a position facing the press roller, the press roller is separated from the outer peripheral surface of the plate cylinder, And the press roller are prevented from interfering with each other, and immediately after the clamper passes the position facing the press roller, the press roller is placed on the outer peripheral surface of the plate cylinder (more precisely, the master wound around the plate cylinder). It is in contact.
[0003]
That is, when printing is performed by the stencil printing apparatus, the press roller repeatedly contacts and separates from the outer peripheral surface of the plate cylinder every time printing is performed on one printing sheet, and the press roller contacts the outer peripheral surface of the plate cylinder. It generates a lot of noise.
[0004]
The stencil printing apparatus described in the above publication is mainly intended to reduce noise when the press roller comes into contact with the outer peripheral surface of the plate cylinder, and these stencil printing apparatuses are shown in FIGS. This will be explained based on.
[0005]
In the stencil printing apparatus shown in FIG. 5, a cylindrically formed plate cylinder 1 is rotatably held by an ink pipe 2 that also serves as a support shaft, and is rotated counterclockwise (arrow direction) by a rotation drive mechanism (not shown). ). Inside the plate cylinder 1, in addition to the ink pipe 2, an ink roller 3 that is driven to rotate in the same direction as the plate cylinder 1 with a minute gap between the plate cylinder 1 and the outer peripheral surface of the ink roller 3 The doctor roller 4 etc. which are arranged with a minute gap between them are provided. An ink reservoir 5 in which the ink supplied from the ink pipe 2 is stored is formed at a portion sandwiched between the outer peripheral surface of the ink roller 3 and the outer peripheral surface of the doctor roller 4.
[0006]
A press roller 6 is provided at a position facing the outer peripheral surface of the plate cylinder 1 so as to be movable in the direction of the arrow to a position close to and away from the outer peripheral surface of the plate cylinder 1.
[0007]
A clamper 8 is provided on the outer peripheral surface of the plate cylinder 1 to hold the tip of the master 7 made by plate making means (not shown). The master cylinder 7 is wound around the outer peripheral surface of the plate cylinder 1 by rotating the plate cylinder 1 after the leading end of the master 7 is clamped by the clamper 8.
[0008]
Further, a sheet-like shock absorber 9 is attached to the outer peripheral surface of the plate cylinder 1. The portion to which the shock absorbing material 9 is attached is the rear position of the clamper 8 along the rotation direction of the plate cylinder 1 and has moved to a position away from the plate cylinder 1 in order to avoid interference with the clamper 8. The press roller 6 is a portion that abuts the outer peripheral surface of the plate cylinder 1 for printing. That is, it is the start end side of the area where the press roller 6 is kept pressed against the outer peripheral surface of the plate cylinder 1 (printing operation rotation angle area). Further, the shock absorber 9 is attached over the entire area where the master 7 is wound in the width direction of the plate cylinder 1.
[0009]
Next, the basic structure of the stencil printing apparatus shown in FIG. 6 is the same as that of the stencil printing apparatus shown in FIG. 5, and the shape of the shock absorbing material 10 attached to the outer peripheral surface of the plate cylinder 1 is different. The shock absorbing material 10 is formed with an inclined portion 10 a extending toward the rear in the rotational direction of the plate cylinder 1.
[0010]
By forming the inclined portion 10a, the press roller 6 in contact with the impact absorbing member 10 rolls along the inclined portion 10a as the plate cylinder 1 rotates, and the press roller 6 passes through the inclined portion 10a. After that, it is pressed against the outer peripheral surface of the plate cylinder 1 to be ready for printing.
[0011]
[Problems to be solved by the invention]
In the stencil printing apparatus described above, the shock absorbers 9 and 10 are attached over substantially the entire area around which the master 7 is wound in the width direction of the plate cylinder 1, and the press roller 6 is connected to the plate cylinder 1 (more precisely, When contacting the shock absorbers 9 and 10) attached to the plate cylinder 1, the press roller 6 uniformly contacts substantially the entire width direction of the outer peripheral surface of the plate cylinder 1.
[0012]
Here, the plate cylinder 1 is formed such that both ends thereof are higher in rigidity than the center portion in order to ensure smooth rotation, ensure strength, etc., and abut an object on the outer peripheral surface of the plate cylinder 1. When this is done, louder noise is generated when it is brought into contact with the central part than when it is brought into contact with both ends thereof. This is because the rigidity of the central portion of the plate cylinder 1 is low and is likely to resonate (vibrate). Therefore, when the press roller 6 comes into contact with the impact absorbing materials 9 and 10, the press roller 6 comes into contact with the central portion of the plate cylinder 1, and the generated noise increases.
[0013]
Further, an ink roller 3 is disposed in the center portion of the plate cylinder 1, and when the center portion of the plate cylinder 1 vibrates due to the contact of the press roller 6, the vibration between the plate cylinder 1 and the ink roller 3 is caused by the vibration. Will be generated and new noise will be generated.
[0014]
Further, since the plate cylinder 1 is lower in rigidity at the center than at both ends, the plate roller 1 is easily damaged when the press roller 6 comes into contact with the center of the outer peripheral surface of the plate cylinder 1 and the life of the plate cylinder 1 is shortened. Shorter.
[0015]
The shock absorbers 9 and 10 are attached over substantially the entire area around which the master 7 is wound in the width direction of the plate cylinder 1, and the master 7 is wound so as to cover the outer periphery of the shock absorbers 9 and 10. ing. For this reason, when the master 7 is wound around the outer peripheral surface of the plate cylinder 1, the shock absorbers 9 and 10 become an obstacle, and the master 7 wound around the plate cylinder 1 is liable to generate wrinkles. As a result, the quality of the printed image decreases.
[0016]
Further, when the press roller 6 comes into contact with the shock absorbers 9 and 10, the impact may directly act on the master 7 covering the buffer absorbers 9 and 10, and the master 7 may be broken.
[0017]
As in the stencil printing apparatus shown in FIG. 5, if there is a step between the shock absorber 9 and the outer peripheral surface of the plate cylinder 1, the press roller 6 enters the step and a pulling force acts on the master 7. Inconvenience of damaging the master 7 occurs. Therefore, such an inconvenience can be solved by using the shock absorbing material 10 having the inclined portion 10a as in the stencil printing apparatus shown in FIG.
[0018]
However, when such a shock absorber 10 is used, the non-printable angle range in the stencil printing apparatus of FIG. 5 is “α °”, whereas the non-printable angle range of the stencil printing apparatus of FIG. “Β ° (β> α)”. That is, when it is desired to increase the printing range while reducing the size of the plate cylinder 1 (when it is desired to reduce the non-printable range), it is not preferable to use the shock absorber 10 having the inclined portion 10a.
[0019]
Accordingly, an object of the present invention is to provide a stencil printing apparatus that can reduce noise generated when a press roller comes into contact with the outer peripheral surface of a plate cylinder.
[0020]
It is another object of the present invention to provide a stencil printing apparatus that can prevent the master from being broken due to repeated contact of the press roller with the outer peripheral surface of the plate cylinder.
[0021]
Further, in the present invention, even if a member for reducing noise generated when the press roller comes into contact with the outer peripheral surface of the plate cylinder is provided, the member does not become an obstacle when the master is wound around the plate cylinder. An object of the present invention is to provide a stencil printing apparatus in which wrinkles are not generated on a wound master.
[0022]
The present invention also provides a stencil printing apparatus that can secure a large printing range even if a member for reducing noise generated when the press roller contacts the outer peripheral surface of the plate cylinder is provided. Objective.
[0023]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided a plate cylinder on which an outer peripheral surface is wound with a master, and an outer peripheral surface of the plate cylinder that is provided so as to be able to contact with and separate from the outer peripheral surface of the plate cylinder and is in a printing operation rotation angle region. In the stencil printing apparatus having a press roller pressed against the outer surface of the plate cylinder, the press roller prints on the outer side of the area around which the master is wound in the width direction of the plate cylinder. Protrusions that abut only the outer peripheral surfaces on both ends of the press roller are provided at a portion that abuts on the start end side of the operating rotation angle region.
[0024]
Therefore, when the press roller comes into contact with the outer peripheral surface of the plate cylinder, the outer peripheral surfaces of both ends of the press roller come into contact with the protrusions provided on both ends of the outer peripheral surface of the plate cylinder, and the press roller comes into contact with the central portion of the plate cylinder. Does not touch. In other words, since the press roller contacts only both ends of the plate cylinder having high rigidity and does not contact the central portion having low rigidity, noise generated when the press roller contacts the outer peripheral surface of the plate cylinder is reduced. The Further, since the press roller does not come into contact with the central portion of the plate cylinder having low rigidity, deformation of the plate cylinder hardly occurs, and the life of the plate cylinder is prolonged. Further, when the master is wound around the outer peripheral surface of the plate cylinder, the protrusion does not become an obstacle to the winding, and the master does not wrinkle when the master is wound around the plate cylinder. Further, the impact when the press roller comes into contact with the plate cylinder does not act directly on the master, and the master is not torn due to the press roller contacting the outer peripheral surface of the plate cylinder.
[0027]
According to a second aspect of the invention, in the stencil printing apparatus of claim 1 Symbol mounting, the projections are thinly formed by compression deformation amount is less material.
[0028]
Therefore, even if the press roller repeatedly makes contact with the protrusion, the protrusion is hardly damaged. In addition, the press roller that comes in contact with the protrusion and is released from the protrusion and pressed against the outer peripheral surface of the plate cylinder becomes ready for printing immediately after it is removed from the protrusion, and the non-printable angle range is reduced, ensuring a large printing range. can do.
[0029]
According to a third aspect of the present invention, in the stencil printing apparatus according to the first or second aspect , buffer portions that contact the protrusions are provided at both ends of the press roller.
[0030]
Therefore, when the press roller comes into contact with the outer peripheral surface of the plate cylinder, the buffer portion of the press roller comes into contact with the projection of the plate cylinder, so that noise generated at the time of contact is further reduced.
[0031]
According to a fourth aspect of the present invention, in the stencil printing apparatus according to the third aspect , the press roller is configured to press a printing sheet conveyed to a printing position against the master, and the press rollers are located on both sides of the pressing section. A buffer portion, and the diameter of the buffer portion is smaller than the diameter of the pressing portion.
[0032]
Therefore, since the buffer portion is a portion that does not press the printing paper at the time of printing, even if the buffer portion is deformed or worn due to an impact when it comes into contact with the protrusion, the deformation or wear is caused by printing at the time of printing. Therefore, the quality of the printed image is favorably maintained.
[0033]
According to a fifth aspect of the present invention, in the stencil printing apparatus according to the fourth aspect , the buffer portion is formed of a material having a higher hardness than the pressing portion.
[0034]
Accordingly, the strength and wear resistance of the buffer portion can be improved, and the distance between the outer peripheral surface of the plate cylinder and the pressing portion can be kept constant when the press roller contacts the outer peripheral surface of the plate cylinder. it can. Further, by making the pressing portion and the buffer portion detachable, when either the buffer portion or the pressing portion is damaged, only the damaged portion can be replaced.
[0035]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIGS. 5 and 6 are denoted by the same reference numerals, and description thereof is omitted. 1 is a front view showing a plate cylinder and a press roller in a stencil printing apparatus, FIG. 2 is a side view thereof, FIG. 3 is a side view showing a state where the press roller is in contact with the plate cylinder, and FIG. It is a side view which shows the state currently pressed by the outer peripheral surface of a trunk | drum and printing.
[0036]
The plate cylinder 1 is formed in a cylindrical shape and is rotatably held by an ink pipe 2 that also serves as a support shaft. In addition to the ink pipe 2, an ink roller 3, a doctor roller 4, and the like are provided inside the plate cylinder 1, and an ink reservoir is provided between the outer peripheral surface of the ink roller 3 and the outer peripheral surface of the doctor roller 4. 5 is formed. The plate cylinder 1 is formed such that the rigidity of both end portions is higher than that of the central portion in order to ensure smooth rotation and secure strength. A master 7 is wound around the outer peripheral surface of the plate cylinder 1.
[0037]
A press roller 11 is provided at a position facing the outer peripheral surface of the plate cylinder 1 so as to be movable to a position that is in contact with and away from the outer peripheral surface of the plate cylinder 1. The press roller 11 is formed by a columnar pressing portion 11a located at the center and columnar buffering portions 11b located on both sides of the pressing portion 11a, and the buffering portion 11b is attached to and detached from the end of the pressing portion 11a. It is connected freely. The pressing part 11a is a part that presses the printing paper 12 conveyed to the printing position (position between the plate cylinder 1 and the press roller 11) at the time of printing against the master 7, and is the length in the width direction of the pressing part 11a. The dimension is slightly larger than the width dimension of the master 7.
[0038]
The pressing part 11a and the buffer part 11b are each formed by winding a rubber material around a core material. A soft rubber material is used for the pressing part 11a, and a hard rubber material is used for the buffer part 11b.
[0039]
Unlike the diameter of the press part 11a and the diameter of the buffer part 11b, the diameter of the buffer part 11b is formed smaller than the diameter of the press part 11a. The difference is about 0.5 mm in the radial dimension.
[0040]
A clamper 8 is provided on the outer peripheral surface of the plate cylinder 1 to hold the tip of the master 7. Furthermore, the press roller 11 that has moved to both ends of the outer peripheral surface of the plate cylinder 1 and moved away from the plate cylinder 1 in order to avoid interference with the clamper 8 is used for printing. A protrusion 13 that is in contact with only the buffer portion 11b is fixed to a portion that is in contact with (a portion on the start end side of the printing operation rotation angle region). The protrusions 13 are located on both sides of the master 7 wound around the plate cylinder 1.
[0041]
The protrusion 13 is formed using a member having a small amount of compressive deformation and a small friction coefficient, such as a mylar film. The protrusion 13 is formed with a small thickness, and when the press roller 11 is in contact with the plate cylinder 1 (more precisely, when the buffer portion 11b is in contact with the protrusion 13), the pressing portion 11a is in the plate cylinder 1. It is formed in the thickness dimension which does not contact | abut to the center part of the outer peripheral surface. Specifically, the thickness dimension of the protrusion 13 is about 1 mm.
[0042]
In such a configuration, the protrusion 13 is fixed to the outside of the area around which the master 7 is wound on the outer peripheral surface of the plate cylinder 1, and the master 7 wound on the outer peripheral surface of the plate cylinder 1 is the outer periphery of the protrusion 13. Do not cover. For this reason, the protrusion 13 does not become an obstacle when the master 7 is wound around the outer peripheral surface of the plate cylinder 1, the wrinkled master 7 is not wrinkled, and the quality of the printed image is good. Maintained. Further, when the press roller 11 comes into contact with the plate cylinder 1 (more precisely, when the buffer portion 11 b comes into contact with the protrusion 13), the press roller 11 does not directly contact the master 7. No tearing occurs.
[0043]
When the press roller 11 comes into contact with the plate cylinder 1, the buffer roller 11 b located at both ends of the press roller 11 comes into contact with the projections 13 at both ends of the plate cylinder 1, and the pressing portion 11 a of the press roller 11 is It does not contact the center of the plate cylinder 1. Since both ends of the plate cylinder 1 have high rigidity, the generation of noise accompanying the contact of the press roller 11 with the plate cylinder 1 is reduced. Further, since the buffer portion 11b made of a rubber material abuts on the protrusion 13, noise generated at the abutment is further reduced. In addition, since the press roller 11 does not come into contact with the central portion of the plate cylinder 1 having low rigidity, the plate cylinder 1 is hardly deformed and the life of the plate cylinder 1 is extended.
[0044]
In the press roller 11, the buffer portion 11b and the pressing portion 11a are formed to be detachable, and the buffer portion 11b is formed using a rubber material harder than the pressing portion 11a. The strength and wear resistance of the buffer portion 11b can be improved. Moreover, when either one of the press part 11a or the buffer part 11b is damaged, only the damaged part can be replaced | exchanged and another part can be used continuously.
[0045]
FIG. 3 shows a state in which the press roller 11 is in contact with the plate cylinder 1 (more precisely, the protrusion 13). Since the buffer portion 11b is 0.5 mm smaller in radius than the press portion 11a and the thickness of the protrusion 13 is 1 mm, when the buffer portion 11b contacts the protrusion 13, the press portion 11a and the plate cylinder A gap of “δ (δ = 0.1 to 0.5 mm)” is ensured between the outer peripheral surface 1 and the outer peripheral surface 1 even in consideration of compression of the buffer portion 11b. Thereby, as described above, the generation of noise can be reduced and the life of the plate cylinder 1 can be extended.
[0046]
Since the protrusion 13 is made of a hard material such as a mylar film and has a small amount of compressive deformation, even if the buffer portion 11b of the press roller 11 repeatedly contacts the protrusion 13, the protrusion 13 is hardly damaged. Further, when the press roller 11 that has come out of contact with the protrusion 13 and is released from the protrusion 13 is pressed against the outer peripheral surface of the plate cylinder 1 to be ready for printing, the press roller 11 is formed thinly because the protrusion 13 is formed thin. Immediately after the protrusion 13 is removed, the printer is ready for printing. For this reason, the non-printable angle range becomes small, and a large print range can be secured.
[0047]
In FIG. 4, printing is performed by pressing the press roller 11 (more precisely, the pressing portion 11 a) against the outer peripheral surface of the plate cylinder 1 (more precisely, the printing paper 12 conveyed to the printing position). State. At the time of printing, only the pressing portion 11 a is pressed against the outer peripheral surface of the plate cylinder 1, and the buffer portion 11 b is separated from the outer peripheral surface of the plate cylinder 1. For this reason, even if the buffer portion 11b is deformed or worn due to repeated contact with the plate cylinder 1, the deformation or wear is not a factor that fluctuates the pressing force acting on the printing paper 12 during the printing operation. The quality of the printed image is maintained in a good state.
[0048]
【The invention's effect】
According to the stencil printing apparatus of the first aspect of the present invention, the outer peripheral surfaces on both ends of the press roller are located at both ends of the outer peripheral surface of the plate cylinder and the portions where the press roller contacts on the start end side of the printing operation rotation angle region. As the press roller comes into contact with the outer peripheral surface of the plate cylinder, the press roller comes into contact only with high rigidity at both ends of the plate cylinder and the rigidity of the central part of the plate cylinder is provided. Therefore, noise generated when the press roller contacts the plate cylinder can be reduced. Further, since the press roller does not come into contact with the central portion having low rigidity in the plate cylinder, deformation of the plate cylinder is less likely to occur, and the life of the plate cylinder can be extended. Further, since the protrusion is provided outside the area where the master is wound in the width direction of the plate cylinder, the protrusion does not become an obstacle to the winding when the master is wound around the outer peripheral surface of the plate cylinder. The master can be prevented from wrinkling when the master is wound around the plate cylinder. Further, the impact when the press roller comes into contact with the plate cylinder does not act on the master, so that it is possible to prevent the master from being broken due to the press roller contacting the outer peripheral surface of the plate cylinder.
[0050]
According to the second aspect of the present invention, in the stencil printing apparatus of claim 1 Symbol placement, projections, since the amount of compressive deformation is formed with less material, the press roller against the protrusions even after repeated contact The damage to the protrusions can be reduced, and the protrusions are thin, so that the press roller that comes out of the protrusions after being in contact with the protrusions and is pressed against the outer peripheral surface of the plate cylinder can be printed immediately after the protrusions are removed. Thus, the non-printable angle range is reduced, and a large print range can be secured.
[0051]
According to a third aspect of the present invention, in the stencil printing apparatus according to the first or second aspect, since the buffering portions that contact the protrusions are provided at both ends of the press roller, the press roller is disposed on the outer peripheral surface of the plate cylinder. When the contact is made, the buffer portion of the press roller makes contact with the projection of the plate cylinder, so that the noise generated at the time of contact can be further reduced.
[0052]
According to a fourth aspect of the present invention, in the stencil printing apparatus according to the third aspect , the press roller includes a pressing portion that presses the printing paper conveyed to the printing position against the master, and the pressing roller positioned on both sides of the pressing portion. Since the buffer portion is formed so that the diameter of the buffer portion is smaller than the diameter of the pressing portion, the buffer portion is a portion that does not press the printing paper at the time of printing. Even if deformation or wear occurs due to impact, the deformation or wear does not cause the pressing force for printing to fluctuate during printing, and the quality of the printed image can be maintained well. .
[0053]
According to the invention described in claim 5, in the stencil printing apparatus described in claim 4 , since the buffer part is formed of a material having a hardness higher than that of the pressing part, the strength and wear resistance of the buffer part are improved. When the press roller comes into contact with the outer peripheral surface of the plate cylinder, the distance between the outer peripheral surface of the plate cylinder and the pressing portion can be maintained constant. Moreover, only the damaged part can be replaced | exchanged as needed by making a press part and a buffer part into a detachable structure.
[Brief description of the drawings]
FIG. 1 is a front view showing a plate cylinder and a press roller in a stencil printing apparatus.
FIG. 2 is a side view thereof.
FIG. 3 is a side view showing a state where a press roller is in contact with a plate cylinder.
FIG. 4 is a side view showing a state in which printing is performed by pressing a press roller against an outer peripheral surface of a plate cylinder.
FIG. 5 is a side view showing an example of a conventional stencil printing apparatus.
FIG. 6 is a side view showing another example of a conventional stencil printing apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Plate cylinder 7 Master 11 Press roller 11a Press part 11b Buffer part 12 Printing paper 13 Protrusion

Claims (5)

A plate cylinder on which a master is wound on the outer peripheral surface, and a press roller provided so as to be able to contact with and separate from the outer peripheral surface of the plate cylinder and pressed against the outer peripheral surface of the plate cylinder in a printing operation rotation angle region. In a stencil printing machine having
On the outside of the area where the master is wound in the width direction of the plate cylinder, which is the both ends of the outer peripheral surface of the plate cylinder, and the part where the press roller abuts on the start end side of the printing operation rotation angle area, A stencil printing apparatus, wherein a protrusion is provided on which only the outer peripheral surfaces of both ends of the press roller abut. The protrusions claim 1 Symbol placement stencil printing machine, characterized in that it is thinner in the amount of compression deformation is less material. Wherein both ends of the press roller, stencil printing machine according to claim 1 or 2, wherein a buffer unit for contact with the projection is provided. The press roller includes a pressing portion that presses the printing paper conveyed to a printing position against the master, and the buffer portion positioned on both sides of the pressing portion, and the diameter of the buffer portion is the diameter of the pressing portion. The stencil printing apparatus according to claim 3 , wherein the stencil printing apparatus is formed smaller. The stencil printing apparatus according to claim 4, wherein the buffer portion is made of a material having higher hardness than the pressing portion.

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