JP3105512U - Rotary grinding wheel for gravure printing roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary grindstone for a gravure printing roll capable of performing gravure printing excellent in finish without causing print unevenness in printed matter.
A rotary grindstone for a gravure printing roll of the present invention has a through hole 1 at the center of which a rotating shaft is attached, and both ends 3 of a 90 ° central angle portion of a great circle 2 concentric with the through hole 1; The shape is a combination of four arcs passing through a bisector 4 having a shorter length than the radius of the great circle 2 on the bisector 4 of the central angle.
[Selection diagram] Fig. 1

Description

  The present invention relates to a rotary grindstone mainly used for polishing the surface of a printing roll used for gravure printing or the like.

  The rotating grindstone for gravure printing rolls is used to polish the peripheral surface of a cylindrical or columnar gravure printing roll so that the printed matter by gravure printing becomes a beautiful printing surface without printing unevenness, As shown in FIG. 4, the load of the rotary grindstone 11 is appropriately adjusted so that the rotary grindstone 11 and the gravure printing roll 12 come into contact with an appropriate contact area and pressure, and the position of the rotary grindstone 11 and the roll 12 is adjusted. Then, while spraying water from a nozzle (not shown) provided on the side to the polishing portion, the rotary grindstone 11 itself reciprocates along the axial direction of the roll while rotating the grindstone 11 itself while rotating at a low speed. It moves and mirror-polishes the printing roll side peripheral surface.

JP-A-2000-24935

Conventionally, a circular grindstone for a gravure printing roll has been generally used. However, in this circular rotary grindstone 11, since the trajectory where the outer peripheral edge of the rotary grindstone 11 comes into contact with the gravure printing roll 12 is substantially straight, a streak-like polishing feed 13 as shown in FIG. However, there is a problem in that this causes printing unevenness in a printed matter during gravure printing.
Therefore, an object of the present invention is to provide a rotary grindstone for a gravure printing roll capable of performing gravure printing with excellent finish without causing print unevenness in a printed material in order to improve the above-described problems. is there.

In view of the above points, the present inventor, as a result of repeating trial and error, does not cause the above-mentioned polishing stitches, or even if a stitch occurs, so that it can be erased by mirror polishing with a rotating grindstone. Has found that it is effective to eliminate the stereotype of a rotating grindstone and to make the rotating grindstone a polygon.
However, if the rotating grindstone is formed in a polygonal shape, no feed stitches remain on the side peripheral surface of the rotating roll, but scratches may occur due to the apex angle of the polygonal shape.

  Therefore, the rotary grindstone of the present invention has a through-hole in which a rotating shaft is mounted at the center, and both ends of a central angle 90 ° portion of a great circle concentric with this through-hole and a great circle on a bisector of the central angle. , And preferably 5 to 10% shorter than the radius of the great circle, and four arcs passing through a point on a bisector are combined.

  More specifically, the shape of this rotary grindstone is, in a circular rotary grindstone having a diameter of 200 mm, composed of four quadrants having a central angle of 90 °, and the outer peripheral side of each quadrant is located at both ends of the quadrant. It is preferably formed by an arc passing through two vertices and a point on a bisector shorter than the radius of the great circle by 7 mm on the bisector of the central angle.

  The rotating grindstone of the present invention having such a shape is formed into a so-called square cam type image without leaving any linear portion at the periphery while leaving an image of a square plate-like body as a whole. By using this for the mirror polishing of the side peripheral surface of the gravure printing roll, an excellent gravure that not only prevents the side peripheral surface of the roll from being stitched by polishing on the side peripheral surface but also does not cause scratches A rotary grindstone for a printing roll is obtained.

  By using the rotating grindstone of the present invention for mirror polishing of a cylindrical or columnar gravure printing roll, the side peripheral surface of the gravure printing roll does not have any feed streaks or scratches due to polishing, so printing unevenness. Gravure printing can be performed with a beautiful printed surface without defects.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a plan view showing an example of the rotary grindstone for a gravure printing roll of the present invention, and FIG. 2 is a schematic explanatory view showing a detailed shape of the rotary grindstone of FIG. FIG. 3 is a perspective view showing an example of the rotary grindstone for gravure printing rolls of the present invention.
As shown in FIGS. 1 to 3, the rotary grindstone of the present invention has a through hole 1 at the center of which a rotating shaft is attached, and both ends 3 of a 90 ° central angle portion of a great circle 2 concentric with the through hole 1. And a point 5 on a bisector having a length shorter than the radius of the great circle 2 on the bisector 4 of the central angle, and a shape in which four arcs convex to the center are combined.

  If the length shorter than the radius of the great circle 2 is larger than the numerical value obtained by the following equation 1 that increases the length, that is, if it is about 30% or more, the new arc becomes concave with respect to the center, An apex (a) of an acute angle occurs, which is not preferable. Even if it is not extremely extreme, if the vertex a is too sharp, a scratch is likely to be formed. Therefore, it is found that the length to be shortened is 5 to 10% of the radius of the great circle in consideration of them.

More specifically, for example, when this shape is applied to a circular rotary grindstone having a diameter of 200 mm, as shown in FIG. The outer peripheral side of the quadrant is defined by two vertices (a, a) at both ends of the quadrant and a point 5 on the bisector which is 7 mm shorter than the radius of the great circle 2 on the bisector 4 of the central angle. Is a rotating grindstone formed by an arc passing through.
The rotating grindstone of the present invention having such a shape can be said to be a so-called square cam type having four sides swelling and a smooth ridge portion without any linear portion on the entire periphery.

  By using such a non-conventional square-based square cam-type rotating grindstone for mirror polishing of a cylindrical gravure printing roll, the trajectory at which the outer peripheral edge of the rotating grindstone contacts the gravure printing roll is reduced. Therefore, since no straight line is formed, no polishing stitches or scratches occur on the side peripheral surface of the gravure printing roll due to polishing.

  By applying the rotary grindstone for gravure printing rolls of the present invention to gravure printing, the quality of any printed matter can be improved, and therefore, its industrial utility value is extremely high.

FIG. 3 is a plan view showing an example of a rotary grindstone for a gravure printing roll of the present invention. FIG. 2 is a schematic explanatory view showing a detailed shape of a rotary grindstone for gravure printing rolls in FIG. 1. FIG. 3 is a perspective view showing an example of the rotary grindstone for gravure printing rolls of the present invention. It is a schematic plan view which shows the positional relationship of a gravure printing roll and a rotary grindstone. It is a schematic plan view which shows the side peripheral surface of a gravure printing roll.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Through hole 2 Great circle 3 Both ends (of 90 degree central angle of great circle) 4 Bisector (at 90 degree central angle of great circle) 5 Point (on bisector of great circle) 11 Rotating grindstone 12 Gravure printing roll 13 Polishing feed
a vertex (on a circle with a central angle of 90 ° of the great circle)

Claims (3)

  It has a through-hole at the center of which a rotating shaft is attached, and both ends of a 90 ° central angle portion of a great circle concentric with the through-hole, and two ends having a length shorter than the radius of the great circle on a bisector of the central angle. A rotary grindstone for a gravure printing roll, characterized in that it has a shape in which four arcs passing through a point on an equal line are combined.   It has a through-hole at the center of which a rotating shaft is attached, and both ends of a 90 ° central angle portion of a great circle concentric with the through-hole and 5-10% shorter than the radius of the great circle on a bisector of the central angle. A rotary grindstone for a gravure printing roll, characterized in that it has a shape in which four arcs passing through a point on a length bisector are combined.   In a circular grinding wheel having a diameter of 200 mm and a through-hole in which a rotating shaft is attached at the center, four quadrants each having a central angle of 90 ° are formed of four quadrants, and the outer peripheral side of each quadrant has two vertexes at both ends of the quadrant. And a point on a bisector shorter than the radius of the great circle by 7 mm on the bisector of the central angle, and a rotary grindstone for a gravure printing roll.

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