JP3939841B2 - Paper peeling structure in printing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a paper peeling structure in a printing apparatus, and more particularly to a peeling structure for peeling paper from a plate cylinder by an air knife method.
[0002]
[Prior art]
For example, in a stencil printing machine, a pre-printed master is wound around the outer peripheral surface of a plate cylinder having an ink supply structure inside, and ink is oozed out from the master perforation part, and the ink image is transferred to the paper pressed against the plate cylinder. To be done.
Since the paper adheres to the surface of the plate cylinder due to the adhesive force of the ink, conventionally, a peeling claw with a sharp tip is provided on the downstream side of the plate cylinder in the paper discharge direction to peel off the paper on which the printed image has been transferred from the surface of the plate cylinder. To be done.
However, in this method, the peeling claw is in direct contact with the image surface of the paper, and thus the problem that the image is rubbed and soiled by the peeling claw cannot be avoided.
[0003]
In order to cope with this problem, in recent years, a so-called air knife method has been adopted in which air is blown between the plate cylinder and the paper to separate in a non-contact state.
This air knife system has a structure as shown in FIG. 10, for example. As shown in the figure, an air blowing member 102 formed with a thin tip is provided on the downstream side of the plate cylinder 100 in the paper discharge direction. The air blowing member 102 generates air flow (not shown). An air flow is supplied from the source.
The paper P supplied from a paper supply unit (not shown) is pressed against the surface of the plate cylinder 100 by a pressing member 104 such as an impression cylinder, whereby an ink image is transferred onto the paper P.
Thereafter, air is blown from the air blowing member 102 between the surface of the plate cylinder 100 and the leading end of the paper P as indicated by an arrow A in accordance with the paper discharge timing.
[0004]
The paper P is continuously peeled off by the air blown along with the rotation of the plate cylinder 100, and is transported by the suction unit 108 provided with the suction fan 106, and is discharged to the paper discharge tray 110 as indicated by a two-dot chain line. Loaded.
[0005]
[Problems to be solved by the invention]
In the case of the air knife method, it is necessary to increase the air discharge speed in order to reliably peel off the paper. Conventionally, an air blower is used to increase the air volume from the air flow source or to efficiently use the air. The cross-sectional shape of the member 102, that is, the duct shape has been devised to cope with it.
However, when the velocity of the air blown out from the air blowing member 102 is high, a negative pressure region 112 is generated below the air flow in the vicinity of the blowing port as shown by hatching in FIG. For this reason, the sheet P that should originally go to the suction unit 108 along the path of the two-dot chain line comes into contact with the lower surface of the air blowing member 102 by the suction action of the negative pressure region 112 and then goes to the suction unit 108 as shown by the solid line. Shows behavior.
Since the surface on which the printed image is transferred contacts the lower surface of the air blowing member 102, the problem of image smearing still occurs like the peeling claw. This problem becomes more prominent when the paper is thin, or in a high-temperature and high-humidity environment where the paper is easily lost.
Further, since the paper is discharged to the paper discharge tray 110 without being sufficiently conveyed by the suction unit 108, a new problem has arisen in that the paper alignment on the paper discharge tray 110 becomes different.
[0006]
Therefore, an object of the present invention is to provide an air knife type paper peeling structure that can solve the problems of image smearing and paper misalignment.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention forms an air flow that cancels the suction action in the negative pressure region in addition to the original air flow that acts as an air knife.
Specifically, in the first aspect of the present invention, an air blowing member that blows out air from an air flow generation source is provided on the downstream side of the plate cylinder in the paper discharge direction, and the air blowing member is provided between the plate cylinder and the paper. In the paper peeling structure in the printing apparatus, in which air is blown to the plate cylinder, air from an air flow generation source is provided between the lower side of the blowout port of the air blowing member and the paper that has started to peel off. A sub air blowing member is provided on the lower surface side of the air blowing member, and the sub air blowing port is air discharged from the sub air blowing port. Is provided so as to flow in a layered manner toward the plate cylinder side outside the lower surface of the air blowing member.
[0008]
According to a second aspect of the present invention, in the configuration of the first aspect, the air flow generation source for sending an air flow to the air blowing member is a blower fan, and the blower fan and the air blower member are integrally configured. , Is adopted.
[0009]
According to a third aspect of the present invention, in the configuration of the first aspect, the air flow generation source for sending an air flow to the sub air blowing member is a blower fan, and the blower fan and the sub air blowing member are integrally configured. The structure is taken.
[0010]
According to a fourth aspect of the present invention, in the configuration of the first aspect, the air blowing member and the sub air blowing member share one air flow generation source.
[0011]
The invention according to claim 5 adopts a configuration in which the air blowing member and the auxiliary air blowing member are integrally formed in the configuration according to claim 1.
[0012]
The invention according to claim 6 adopts a configuration in which the air blowing member and the sub air blowing member share one air flow generation source in the configuration according to claim 5.
[0013]
According to a seventh aspect of the present invention, in the configuration according to the sixth aspect, the one air flow generation source is a blower fan, and the blower fan is integrally formed with the air blowing member and the sub air blowing member. , Is adopted.
[0017]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, a pressing member 4 such as an impression cylinder that is in pressure contact with the printing cylinder 2 is provided opposite to the printing cylinder 2, and is located downstream of the printing cylinder 2 in the paper discharge direction (arrow F direction). Is provided with an air knife blower 6 that blows and peels air between the plate cylinder 2 and the paper P. On the downstream side of the pressing member 4 in the paper discharge direction, a suction unit 8 is provided that transports the paper P peeled off by the air knife blower 6 while sucking it. The suction unit 8 includes a transport guide plate 10 and a transport belt 12. , A waist guide plate 14, a suction fan 16 (FIG. 2), and the like.
[0018]
The air knife blower 6 is integrally composed of an air blowing member 18 and a centrifugal blower fan 20 as an air flow generation source. The air blowing member 18 is formed in a cross-sectional shape that gradually narrows toward the plate cylinder 2 side, and has a blowing port 22 that widens toward the end in the axial direction of the plate cylinder 2. Two sub-blowing ports 24, 24 are formed on the bottom surface of the air blowing member 18 at an interval in the axial direction of the plate cylinder 2.
The blowout port 22 is an air flow for peeling the paper P from the plate cylinder 2, that is, an air knife discharge port, and the sub blowout port 24 is located between the lower portion in the vicinity of the blowout port 22 and the paper P peeled off by the air knife. It is for discharging an air flow. Therefore, the air blowing member 18 becomes a sub air blowing member when the sub blowing port 24 is taken as a reference.
That is, the air knife blower 6 is configured by integrally configuring an air blowing member and a sub air blowing member, and further integrally configuring a blower fan 20 as an air flow generation source. The air blowing member 18 and the sub air blowing member 18 share one blower fan 20.
[0019]
Next, the peeling operation of the paper P by the air knife blower 6 will be described based on FIG.
As shown in the figure, the air flow supplied from the blower fan 20 is discharged from the blowout port 22 and is blown between the surface of the plate cylinder 2 and the paper P, and the main airflow A indicated by a solid line as an air knife. ₁ and a sub-air flow (bypass flow) A ₂ indicated by a dotted line discharged from the sub blow-out port 24. When the negative pressure region 26 is generated by the main air flow A ₁ , the sub air flow A ₂ flows in a layered manner on the lower surface of the negative pressure region 26, so that the sub air flow A ₂ is temporarily separated by the main air flow A _{1 as} indicated by a two-dot chain line. be attracted sheet P is the suction effect of the negative pressure area 26, it does not contact the lower surface of the air outlet member 18 by the presence of auxiliary air flow a _2. Due to the presence of the auxiliary air flow A ₂ , the paper can be satisfactorily peeled without contact even when the paper is thin, or in an environment of high temperature and high humidity.
Further, since the auxiliary air flow A ₂ acts to push the paper P back toward the pressing member 4, the paper P returns to the original discharge path at an early stage and is sufficiently sucked and conveyed by the suction unit 8 while being discharged. Therefore, there is no variation in paper alignment.
[0020]
The sub blowout port 24 can be easily formed by pressing, drawing, or the like, and an optimum sub air flow A ₂ can be formed by changing the rising angle θ of the inclined surface 24a.
[0021]
Next, a reference example will be described based on FIGS. In addition, the same part as the said Example is shown with the same code | symbol, and description of the structure and function is abbreviate | omitted suitably (hereinafter, the same).
On the downstream side of the plate cylinder 2 in the paper discharge direction, an air knife blower 30, a sub air blowing member 32 assembled integrally with the air knife blower 30, and an air flow integrally formed with the sub air blowing member 32 are provided. An axial flow type blower fan 34 as a generation source is provided.
The air knife blower 30 has an air blowing member 36 configured integrally with the blower fan 20. The shape of the air blowing member 36 is based on the air blowing member 18 in the above embodiment, but a concave portion 38 for accommodating the sub air blowing member 32 in an intersecting state is formed in the center portion, thereby the plate cylinder 2. There are two outlets 40, 40 spaced apart in the axial direction.
[0022]
Next, the peeling operation of the paper P in this reference example will be described based on FIG.
As shown in the figure, the air flow supplied from the blower fan 20 of the air knife blower 30 is discharged as a main air flow A3 (indicated by a solid line) from the air outlet 40 of the air outlet member 36, and the surface of the plate cylinder 2 Sprayed between the sheets P. On the other hand, the air flow supplied from the blower fan 34 passes from the lower surface of the air blowing member 36 through the sub air blowing member 32 and intersects the main air flow A3 as the sub air flow A4 (indicated by a dotted line). It is sprayed between 40 vicinity and the paper P which peels by main airflow A3.
The sub-air flow A4 in the present reference example has a larger incident angle with respect to the paper P than the sub-air flow A2 in the above-described embodiment, and thus the action of pushing the paper P back to the pressing member 4 side is large. Therefore, even if the negative pressure region 42 is generated by the main air flow A3, the paper P is forcibly pushed back to the pressing member 4 side by the sub air flow A4. For this reason, the paper P peeled off by the main air flow A3 is discharged to the paper discharge tray 28 while being sufficiently sucked and conveyed by the suction unit 8, and the paper alignment is also improved.
In the case of this reference example, the optimum auxiliary air flow A4 can be formed by changing the crossing angle of the auxiliary air blowing member 32 with respect to the air blowing member 36.
[0023]
Although the peeling structure by a specific structure was shown in the said Example and reference example , it is not the meaning limited to these, For example, you may provide in the state which isolate | separated the air blowing member and the subair blowing member, and air You may make it supply an air flow with an air hose using a pneumatic press instead of a ventilation fan as a flow generation source.
[0024]
Next, another reference example will be described with reference to FIGS.
As shown in FIG. 5, a pressure cylinder 44 is provided opposite to the plate cylinder 2 so as to be able to contact with and separate from the plate cylinder 2, and on the downstream side of the plate cylinder 2 in the paper discharge direction, An air blowing member 46 for blowing air between the paper P is provided. A clamper 48 is provided on the outer surface of the impression cylinder 44 to sandwich the leading end of the paper P supplied from a paper supply unit (not shown). The clamper 48 is opened and closed at a predetermined timing by an opening / closing mechanism (not shown). ing.
The air blowing member 46 is supplied with air from an air flow generation source (not shown) such as a blower fan or a pneumatic press. In FIG. 5, reference numeral 50 denotes a paper conveyance guide.
[0025]
The air blowing member 46 is formed in a cross-sectional shape that gradually narrows toward the plate cylinder 2 side, and has a blowing port 52 that widens toward the end in the axial direction of the plate cylinder 2. A ring-shaped shaft support portion 54 that protrudes in the axial direction of the plate cylinder 2 is integrally formed at the upper end of the blowout port 52, and the shaft portion 56 a is supported by the shaft support portion 54, so that the air flow diverting plate 56. Is provided so as to be rotatable in the vertical direction.
The air flow diverting plate 56 changes the direction of the air flow as an air knife discharged from the blowout port 52 of the air blowing member 46, and the variable operation is performed by the drive mechanism 58.
[0026]
One end of the drive mechanism 58 is attached to the shaft portion 56a of the air flow diverting plate 56 so as to be able to rotate synchronously, and the arm 62 having the cam follower 60 at the other end and the air flow diverting plate 56 are in the direction of the air flow. A spring 64 as a biasing means for constantly biasing the arm 62 so as to be positioned at the upper limit position U shown in FIG. 5 and a position where the pressure drum 44 is synchronously rotated with one end side of the pressure drum 44. The cam 66 is provided. The cam 66 has a non-driving surface 66 a and a driving surface 66 b that swings the arm 62.
[0027]
Next, the peeling operation of the paper P in this reference example will be described.
FIG. 5 shows a state in which the clamper 48 of the impression cylinder 44 sandwiches the leading end of the paper P supplied from a paper supply unit (not shown) before the ink image of the plate cylinder 2 is transferred to the paper P.
Thereafter, as shown in FIG. 6, when the impression cylinder 44 is brought into pressure contact with the plate cylinder 2 for transfer, the cam follower 60 of the arm 62 comes into contact with the non-driving surface 66 a of the cam 66. In this state, the air flow diverting plate 56 is maintained at the upper limit position U, and the air flow A5 as an air knife from the air blowing member 46 is based on the discharge timing when the clamper 48 of the impression cylinder 44 is opened. Sprayed between the surface of the cylinder 2 and the paper P. As a result, the leading end of the paper P is peeled off from the surface of the plate cylinder 2.
[0028]
When the plate cylinder 2 and the impression cylinder 44 rotate, the cam follower 60 rides on the drive surface 66b of the cam 66 as shown in FIGS. 7 and 8, so that the arm 62 resists the biasing force of the spring 64. Turn to 8 side. In synchronization with the rotation of the arm 62, the air flow diverting plate 56 also rotates downward, and the air flow diverting plate 56 is finally maintained at the lower limit position D shown in FIG.
As the air flow diverting plate 56 pivots downward, the direction of the air flow A5 is changed to the paper discharge side, that is, the direction in which the paper P is pressed against the surface of the impression cylinder 44.
Due to the change in the direction, the weight of the action of the air flow A5 shifts from the action of the air knife to the pressing action for discharging the paper P satisfactorily. This action change is made smoothly and quickly because the boundary between the non-drive surface 66a and the drive surface 66b of the cam 66 is formed as a curved surface.
As a result, even if a negative pressure region is generated in the vicinity of the air outlet 52 of the air blowing member 46 due to the air flow A5, the paper P is immediately pushed back to the impression cylinder 44 side, and good discharge without contacting the air blowing member 46 is achieved. Follow the path.
As described above, in this reference example, the initial stage of the peeling process is performed by the original air knife action of the air flow A5, and thereafter, the same air flow A5 is controlled so as to mainly act as the auxiliary air flow in the reference example. It is.
[0029]
Next, a modified example of the reference example of the air flow turning type will be described with reference to FIG.
In this reference example, an opening 68 is formed on the bottom surface of the air blowing member 46 in the vicinity of the blowing port 52, and a shaft support portion 54 is formed on the blowing port 52 side of the opening 68. Similar to the above reference example, an air flow diverting plate 56 is rotatably supported by the shaft support portion 54 and is driven by a drive mechanism 58.
The air flow diverting plate 56 pivots in the vertical direction on the inner side of the air blowing member 46, and closes the opening 68 when the cam follower 60 is in contact with the non-driving surface 66 a of the cam 66. When the cam follower 60 rides on the drive surface 66b of the cam 66, the upper limit position S is maintained as shown in FIG.
[0030]
At the start of the peeling operation, the opening 68 is closed by the air flow diverting plate 56. Therefore, all the air supplied from an air flow generation source (not shown) is supplied from the outlet 52 to the plate cylinder as a main air flow A6. 2 and the paper P.
As the plate cylinder 2 and the impression cylinder 44 rotate, the air flow diverting plate 56 rises upward and the opening 68 is opened. When the opening 68 is opened, a sub air flow A7 is generated and acts to press the paper P toward the impression cylinder 44. Accordingly, the paper P follows a good discharge path without contacting the air blowing member 46 as in the above reference examples.
The pressing action of the sub air flow A7 increases with the upward rotation of the air flow diverting plate 56, and the air knife action of the main air flow A6 decreases correspondingly.
[0031]
As in the embodiment shown in FIGS. 1 and 2, the present reference example has a configuration in which the main air flow A6 and the auxiliary air flow A7 are formed by a single air blowing member 46, which is shown in FIGS. In the embodiment, the sub blowout opening 24 is always open on the entire surface, whereas in the present reference example, the opening 68 is opened over time as the peeling operation proceeds.
Therefore, at the start of the peeling operation, there is no loss due to the outflow of air from the opening 68, and all the air from the air flow generation source (not shown) can act as an air knife, which is shown in FIG. 1 and FIG. An equivalent peeling function can be obtained with a smaller air flow rate than in the examples.
[0032]
In any of the above cam drive systems, the cam 66 is provided on the impression cylinder 44, but may be provided on the plate cylinder 2. In addition, although the driving force of the air flow diverting plate 56 is obtained by the rotational force of the impression cylinder 44 or the plate cylinder 2, an operation source of the driving mechanism 58 may be provided separately.
[0033]
【The invention's effect】
According to the first aspect of the present invention, since the auxiliary air blowing member that blows air from the air flow generation source is provided between the lower side of the air blowing member and the sheet that has started to be peeled, the negative air blowing member is provided. Even if the pressure region is generated and the sheet is about to be sucked, it is possible to prevent the sheet from coming into contact with the air blowing member by the air blown from the sub air blowing member, thereby preventing image smearing. it can.
Further, the paper can be put on a normal discharge process by the action of pushing back the air blown from the sub air blowing member, and a good paper alignment on the paper discharge table can be obtained.
The same peeling function can be obtained even when the paper is thin or in a high-temperature and high-humidity environment.
[0034]
According to the second aspect of the present invention, since the air flow generation source is a blower fan and the blower fan and the air blowing member are integrally formed, in addition to the effect of the first aspect, when using a pneumatic press or the like Compared to the configuration, the size and cost can be reduced.
[0035]
According to the third aspect of the present invention, the air flow source is a blower fan, and the blower fan and the auxiliary air blowing member are integrally formed. Therefore, in addition to the effect of the first aspect, a pneumatic press or the like is used. Compared to the above, the configuration can be made compact and the cost can be reduced.
[0036]
According to the invention described in claim 4, since the air blowing member and the sub air blowing member share one air flow generation source, in addition to the effect of claim 1, the air flow generation source is used individually. Compared to the configuration, it is possible to reduce the size and cost of the configuration.
[0037]
According to the invention described in claim 5, since the air blowing member and the sub air blowing member are integrally formed, in addition to the effect of claim 1, the configuration is made compact and the cost is reduced as compared with the case where it is provided individually. Can be achieved.
[0038]
According to the sixth aspect of the present invention, since the air blowing member and the sub air blowing member are configured integrally and further configured to share one air flow generation source, in addition to the effect of the fifth aspect, a further configuration is provided. Can be reduced in size and cost.
[0039]
According to the seventh aspect of the present invention, the air blowing member and the sub air blowing member are integrally configured, and further, the one blower fan is integrally configured to be shared. Further, the configuration can be made compact and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view of an essential part of a sheet peeling structure in a printing apparatus according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a paper peeling structure in the printing apparatus shown in FIG.
FIG. 3 is a perspective view of a main part of a sheet peeling structure in a printing apparatus according to a reference example.
4 is a cross-sectional view of a paper peeling structure in the printing apparatus shown in FIG. 3;
FIG. 5 is a cross-sectional view of a paper peeling structure in a printing apparatus according to another reference example, showing a state before transfer.
6 is a cross-sectional view of a paper peeling structure in the printing apparatus shown in FIG. 5, showing a state where the impression cylinder is in pressure contact with the plate cylinder.
7 is a cross-sectional view of the paper peeling structure in the printing apparatus shown in FIG. 5, showing a state in which the air flow direction change plate has moved slightly.
8 is a cross-sectional view of the paper peeling structure in the printing apparatus shown in FIG. 5, and shows a state in which the air flow is completely turned to the paper discharge side by the air flow turning plate.
FIG. 9 is a cross-sectional view of a sheet peeling structure in a printing apparatus according to still another reference example, showing a state in which a sub air flow is formed by the rotation of an air flow diverting plate.
FIG. 10 is a schematic sectional view showing a conventional example.
[Explanation of symbols]
2 Plate cylinder 4 Pressing member 18 Air blowing member 18 Sub air blowing member 20 Blowing fan 22 as air flow generation source 22 Blowing port 32 Sub air blowing member 34 Blowing fan 40 as air flow generation source 40 Blowing port 44 Pressure as pressing member Cylinder 46 Air blowing member 52 Blowing outlet 56 Air flow diverting plate 58 Drive mechanism 62 Arm 64 Spring 66 as biasing means Cam P Paper

Claims (7)

An air blowing member that blows out air from the air flow generation source is provided on the downstream side of the plate cylinder in the sheet discharge direction, and air is blown from the air blowing member between the plate cylinder and the sheet to peel the sheet from the plate cylinder. In the paper peeling structure in the printing device,
A sub air blowing member that blows air from an air flow generation source is provided between the lower side of the air blowing member and the sheet that has started to be peeled off. Is opened on the lower surface side of the air blowing member, and the sub-blowing port is provided so that air discharged from the sub-blowing port flows in a layered manner on the outer side of the lower surface of the air blowing member toward the plate cylinder side. A paper peeling structure in a printing apparatus. In the paper peeling structure in the printing apparatus according to claim 1,
An air flow generation source for sending an air flow to the air blowing member is a blower fan, and the blower fan and the air blower member are integrally configured. In the paper peeling structure in the printing apparatus according to claim 1,
An air flow generation source for sending an air flow to the sub air blowing member is a blower fan, and the blower fan and the sub air blowing member are integrally configured. In the paper peeling structure in the printing apparatus according to claim 1,
The paper peeling structure in a printing apparatus, wherein the air blowing member and the sub air blowing member share one air flow generation source. In the paper peeling structure in the printing apparatus according to claim 1,
The paper peeling structure in a printing apparatus, wherein the air blowing member and the sub air blowing member are integrally formed. In the paper peeling structure in the printing apparatus according to claim 5,
The paper peeling structure in a printing apparatus, wherein the air blowing member and the sub air blowing member share one air flow generation source. In the paper peeling structure in the printing apparatus according to claim 6,
The sheet peeling structure in a printing apparatus, wherein the one air flow generation source is a blower fan, and the blower fan is integrally formed with the air blowing member and the sub air blowing member.

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