JP2006051634A - Printing press blanket cylinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blanket cylinder capable of easily and easily mounting a blanket of a type in which a blanket sheet is fixed to the surface of a flexible plate, and aims to stabilize printing quality and reduce waste paper during printing. And
A body groove having an opening along the axial direction on the surface of the blanket cylinder, a slit groove that is rotatably provided in the body groove and into which a tail end side end plate of the blanket is inserted, A tension bar having a pressing surface for pressing the grip end side end plate of the blanket, and a recess in the center side of the grip side inner surface of the body groove, and the blanket grip end plate in the recess It is characterized by being configured to bend and deform by pressing on the pressing surface.

[Selection] Figure 2

Description

The present invention relates to a blanket cylinder in which a blanket having a blanket sheet fixed to the surface of a thin flexible plate is mounted on a cylinder of a printing press.

  The blanket cylinder in the offset printing press has a function of accurately transferring the printed image from the plate surface on the outer periphery of the plate cylinder to the printing material. The wound blanket is different from the plate that is attached and detached whenever the image changes. It is used while being fixed to the cylinder for a long time until it causes a state of performance deterioration that affects the print quality. Therefore, the contact pressure during printing with the plate cylinder or the printing material, that is, the printing pressure (nip), is repeatedly received during this time, so-called squeezing, so that the structure can withstand this.

A conventional blanket of a printing press has a shape in which fixing metal fittings are integrated at both ends of a blanket sheet, and a method of winding and fixing the cylinder using the metal fittings is disclosed in, for example, Japanese Patent No. 2746839 or Japanese Patent Laid-Open No. 2-56215. ing. (Hereinafter referred to as the first prior art)
In the case of the blanket specification disclosed in the first prior art, there is a drawback in that the cylinder groove width in the axial direction of the cylinder mounting position is structurally large, so that vibration occurs in the rotating cylinder during printing, which adversely affects print quality. In recent years, the effect has become more prominent as the printing press speeds up.

Although a method of eliminating the body groove has been put into practical use as a measure for solving the vibration problem, there is a method of narrowing the body groove width as a method of obtaining an effect without significantly changing the main part configuration of the conventional printing press. In recent years, means using a blanket in which a blanket sheet is fixed to the surface of a thin flexible plate has been put into practical use. Examples of such means are disclosed in JP-A-9-99543 and Japanese Patent No. 3446122.

In the second prior art, Japanese Patent Laid-Open No. 9-99543, a blanket front and rear leg has a spindle capable of rotational displacement, in which pressing protrusions are arranged at an appropriate pitch in the axial direction in a slit opened on the outer peripheral surface in the blanket cylinder axial direction The part support plate is inserted into the slit, and both leg parts are pressed together by the pressing projections acting on the side surface of the slit with spring force.

In the third prior art, the above-mentioned Japanese Patent No. 3446122, as shown in FIG. 6, the rear end portion of the blanket base plate is bent in two steps, and the second step in the front end is bent at an acute angle. A retracting shaft to which a rotational force is applied so as to be hooked on the flange portion and retractable is disposed. This structure is a known technique that has been around for a long time, but a winding torsion spring that is hung on the end of the retracting shaft is employed as means for applying a rotational force.

As described in the background section above, the second and third prior arts have been disclosed as means for narrowing the cylinder groove width for the purpose of reducing cylinder vibration during printing.
In the second prior art, there is no way to absorb the slack due to the continuous nip rotation during printing, the so-called blanket extension caused by ironing, and only the partial pressing frictional force of only the pressing protrusions is used to fix the leg plate. The holding force is not sufficient for holding, and there is a drawback in that the ironing and vibration and the repulsive force and centrifugal force of the support plate cooperate to generate fine movement and slack of the blanket and affect the print quality.

In the third prior art, as a countermeasure against the slack of the blanket, the blanket tail end is pulled in to try to eliminate the slack generation of the blanket. Blanket tremors and slacks are not eliminated.
Of course, it is clear that the influence does not reach enough to eliminate the slack of the tail end of the tail side that has been wound 360 ° by the pulling of the tail end side, and another countermeasure against slackness was required.
In addition, as described in the background art section, the blanket has a printing durability and is manufactured so as to be usable for a long time. That is, a plate in which a blanket sheet is attached and integrated is also considered to withstand long-term ironing, and unlike a printing plate, a tough metal material, for example, a thin plate of stainless steel or the like is generally used. Therefore, the repulsive force at which the plate at the end fixing portion is pulled out due to the restoring force of the plate wound around the cylinder by elasticity to return to the original flat plate shape is very large.
Unlike the second prior art, as a means for separating and holding the tail side from the tail edge side, there is a Japanese Patent Publication No. 7-080298 (referred to as the fourth prior art) of a plate winding apparatus shown in FIG. Although this publication is for a plate, not for a blanket, there is disclosed a biasing means for holding the end of the plate against the inner side of the cylinder groove and pressing the plate winding shaft. However, as in the second conventional example in which the blanket plate is pressed flat, only the frictional force is retained, so that the retention performance is low with respect to shock and vibration during ironing, and the occurrence of fine movement and slack has not been eliminated.

On the other hand, when the blanket plate is to be bent and deformed in the blanket mounting operation, a large force is required due to the same elasticity (rigidity) of the plate as described above. For example, the same applies to the second prior art, but the third prior art example will be described with reference to FIG. 6. The blanket is inserted into the slit and the blanket is wound around the barrel together with the barrel rotation. When trying to insert the bottom side into the slit, the leading edge of the plate to be inserted is longer than the bending position of the first end of the end that matches the slit position, and is shifted from the slit position. It is shifted in the circumferential direction of the body, and the tip portion is inserted into the slit. However, often cause the slack just another wrapping with portions since the rigidity of the plate is present, there are cases where forced operation for removing the slack of the newly the barrel winding section after inserting the tip.

As described above, the loose side at the time of printing operation and the loosening at the time of mounting and removal work of the highly elastic blanket plate are eliminated, and the tail end of the tail edge side is fastened to cope with the extension of the plate. A functional blanket cylinder was required.

  In order to solve the above-mentioned problem, the present invention according to claim 1 is a cylinder groove having an opening along the axial direction on the surface of a blanket cylinder on which a blanket having a blanket sheet fixed to the surface of a flexible plate is mounted. A tension bar provided rotatably in the body groove and having a slit groove for inserting a blanket tail end plate and a pressing surface for pressing the blanket tail end plate; A concave portion is formed on the inner side of the barrel groove inner side of the trunk groove, and the blanket tail end plate is pressed and bent by the pressing surface in the concave portion.

Further, in order to solve the above-mentioned problem, the present invention according to claim 2 is characterized in that a concave portion provided on the inner side of the inner side of the inner side of the body groove is provided with an inner surface of a cylindrical hole into which the tension bar is inserted in the axial direction It is characterized by having a dual-use configuration.
The invention according to claim 3 is characterized in that the convex surface portion that changes from the inner side surface of the body groove to the concave surface provided on the center side of the body groove is roughened or coated. Yes.

  Furthermore, in order to solve the above-mentioned problem, the present invention according to claim 4 is characterized in that the tension bar outer peripheral surface on the blanket holding side of the slit groove in a state where the slit groove of the tension bar faces the body groove. The present invention according to claim 5, wherein the slit groove of the tension bar is opposed to the body groove, and the blanket is at the tail edge side of the blanket at the outer peripheral corner of the blanket. A feature is that a chamfer guide is provided so that the end plate can be easily inserted.

In the present invention described in claim 6, the end of the blanket tail plate of the blanket is bent in two steps, and the bending angle θ1 of the first step is approximately 90 °, and the second step on the tip side. When the eye bend angle θ2 is an obtuse angle of 140 ° or more and the blanket's tail end is inserted into the trunk groove and then wrapped around the trunk surface and the tail end is inserted into the trunk groove, the blanket is in the circumferential direction of the trunk It is characterized in that it can be inserted up to the slit groove of the tension bar without being moved.

According to the blanket mounting device described in the present invention, since the elastic plate is elastically deformed and fixed, even with a strong and rigid blanket plate, the holding end edge of the plate is secured, and the plate floats or loosens due to fine movement or disconnection. Can be prevented.
Also, the position of the tail end on the tail end is almost the same as that of the slit, and it is easy to insert, so there is no occurrence of floating or loosening of the plate around the body wrapping. The blanket can be installed reliably in time.

Of course, although not shown, a rotational force is applied to the tension bar so as to constantly generate and maintain the tension for pulling in the blanket, and the pulling force absorbs and eliminates slack due to the blanket's squeezing.

A blanket mounting device according to an embodiment of the present invention will be described with reference to FIGS. In addition, the overlapping description which concerns on the same site | part as the above-mentioned conventional thing is abbreviate | omitted as much as possible.
FIG. 1 is a view of the tail edge end mounting state, and FIG. 2 is a sectional view of the blanket mounting completed state.

Both end shaft portions of the blanket cylinder 1 are rotatably supported by a printing machine frame via bearings (not shown). A narrow body groove (gap) 5 opens on the surface of the blanket cylinder in parallel with the cylinder center axis, and a cylindrical hole 6 is provided in the cylinder radial direction center side of the cylinder groove 5, and a tension bar 2 is provided in the cylindrical hole 6. Is rotatably arranged. The tension bar 2 is provided with an attachment groove 2a, and the holder 3 and the pressing bar 4 are fixed to the side surfaces of the attachment groove 2a to create a slit 7.
The width of the slit 7 is the blanket plate 9a end thickness T + δ, and δ varies slightly depending on the material and rigidity of the plate 9a and the blanket sheet specifications, but basically the plate is easy to insert and has the maximum holding force. It is set to an optimal value to ensure.

  The cylindrical hole 6 is positioned and processed so that the cylindrical surface on the grip side is recessed by α dimension with respect to the grip side inner surface 5 a of the body groove 5. That is, in FIG. 1 to FIG. 3, the side-side dent is also used as the machining surface of the cylindrical hole to simplify the manufacturing process. The recess 8 on the inner side surface 5a of the gripping side may have a different shape that does not serve as the cylindrical hole 6 as shown in FIG.

The recess 8 on the inner side surface 5a is a relief space for pressing and elastically deforming the blanket end plate, and the pressing surface 4a holds the plate 9a in contact with the inner surface of the recess. It is not pressed. Accordingly, the pressing operation by the pressing surface 4a is only a position changing operation by the rotation of the tension bar 2, and no special means such as a biasing means for pressing the main plate side end plate is required, and the elastic force at the time of plate deformation is not required. A holding surface pressure is naturally generated.
During the pressing operation, the end plate is elastically deformed, but a strong surface load is applied to the change convex portion R where the plate contacts the inner side surface 5a to the concave portion 8 surface. Therefore, there is a concern that the holding force decreases due to elastic bending due to wear with use during operation. In order to prevent this, a surface treatment for wear resistance, such as plating, can be applied to the change convex portion R.
Further, in order to reduce the slip of the end plate and increase the holding force, a method of processing the surface of the changing convex portion R into a rough surface or a waveform can be applied.

The pressing bar 4 having the pressing surface 4a constitutes the slit 7 for holding the blanket tail end plate 9a together with the holder 3, but as shown in FIG. 1, it functions to guide and smooth the end plate insertion. The chamfer 4b is given to the outer peripheral corner of the slit surface.
The pressing bar 4 and the slit 7 constituting surfaces 4 s and 3 s of the holder 3 and the corner 3 e of the holder 3 are partially or entirely roughened or surfaced to increase the holding force of the inserted end plate. Processing and other processing can also be performed. For the surface treatment, a method of coating a resin or rubber can be employed.
In addition, when the specifications such as the thickness of the blanket plate 9a change, or when trouble occurs due to wear deformation of the current product, the press bar 4 or holder 3 can be easily replaced with a new product, and the slit 7 groove width is also desired. It has a structure that can be changed to a value.

The end of the blanket tail plate on the blanket is folded in two steps, and the dimensions vary depending on the size and detailed shape of the mounting device. The bend angle θ2 is an obtuse angle of 140 ° or more. As a result, as shown in FIG. 1, the tail end plate 9a is inserted into the body groove 5 and the slit 7 in the direction of the involute curve as shown by the arrow without greatly deforming the blanket or moving the blanket in the circumferential direction of the body. Insertion / removal is possible only by shifting only the end. Therefore, after inserting the tail end and wrapping it around the barrel, there is no slack in the blanket around the waist when inserting the tail end, and the blanket can be securely and smoothly installed. Is no longer necessary.

Sectional drawing of the mounting apparatus at the time of blanket tail end part insertion concerning this invention

Sectional drawing of the blanket installation completion state based on this invention

2 is a detailed view of the pressing side concave portion pressing state of FIG. 2 according to the present invention.

3 is another detailed drawing of the shape of the recess on the side of the side of FIG.

Blanket vertical section detail view

Cross-sectional configuration diagram of the trunk groove portion of the third prior art

Cross-sectional configuration diagram of the trunk groove portion of the fourth prior art

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Blanket cylinder 2 Tension bar 2a Mounting groove 3 Holder 3e Holder corner | angular part 3s Slit surface 4 Pressing bar (pressing member) 4a Pressing surface 4b Chamfering 4s Slit surface 5 Body groove (gap) 5a Holding side inner surface 6 Cylindrical hole 7 Slit 8 Recess 9 Blanket 9a Plate 9b Blanket sheet
R Deflection on the inner surface of the trunk groove T Blanket plate thickness α Recess dent amount θ1 Plate tail edge side first step bending angle θ2 Plate tail edge side second step bending angle

Claims (6)

  A blanket cylinder of a printing press in which a blanket with a blanket sheet fixed to the surface of a flexible plate is mounted, and a cylinder groove having an opening in the axial direction on the surface of the cylinder, and rotatable inside the cylinder groove A tension bar having a slit groove into which the blanket tail end plate of the blanket is inserted and a pressing surface for pressing the blanket tail end plate of the blanket; A blanket cylinder for a printing press, wherein a concave portion is provided on the cylinder center side, and the blanket grip side end plate is pressed and bent by the pressing surface in the concave portion. The blanket cylinder of a printing press according to claim 1, wherein a concave portion provided on a cylinder center side of the inner side surface of the cylinder groove is also used as an inner surface of a cylindrical hole into which the tension bar is inserted in the axial direction. The blanket cylinder of a printing press according to claim 1 or 2, wherein the convex surface portion that changes from the inner side surface of the cylinder groove to the concave surface provided on the cylinder central portion side is roughened or coated. . 4. The blanket cylinder of a printing press according to claim 1, wherein a pressing surface is provided on an outer peripheral surface of the tension bar on the blanket holding side of the slit groove in a state where the slit groove of the tension bar faces the cylinder groove. . With the slit groove of the tension bar facing the body groove, a chamfer guide is provided at the blanket handle side outer peripheral corner of the slit groove so that the blanket tail end plate can be easily inserted into the slit groove. 5. A blanket cylinder for a printing press according to claim 1. The blanket tail plate end of the blanket is bent in two steps, the first step bending angle is about 90 °, and the tip second bending angle is an obtuse angle of 140 ° or more. When the blanket tail end is inserted into the trunk groove and wound around the trunk surface and the blanket tail end is inserted into the trunk groove, the blanket is not moved in the circumferential direction of the trunk bar. 6. The blanket cylinder of a printing press according to claim 1, wherein the blanket cylinder can be inserted into the groove.

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