JP2008221449A - Doctor blade polishing device and method of polishing doctor blade - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a doctor blade polishing device such that the defect of printing and the change of darkness of printing with time are eliminated by eliminating the nonuniformity of polishing by a doctor blade abrasive powder produced by the polishing operation of a doctor blade. <P>SOLUTION: This doctor blade polishing device polishes the doctor blade 100 of a doctor for scraping off an ink excessively supplied onto the surface of the plate cylinder of a photogravure. The doctor blade polishing device comprises: a cylinder grinding wheel 50 similar to the outer shape of a gravure cylinder 30; a polishing part formed on the peripheral surface of the cylinder grinding wheel 50; a rotatingly driving means for rotatingly driving the cylinder grinding wheel; a means for movably supporting the doctor blade and pressing the doctor blade 50 against the polishing part; and a removal means 200 for removing the doctor blade abrasive powder remaining on the polishing part. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention belongs to the technical field of gravure printing. In particular, the present invention relates to a doctor blade polishing apparatus for polishing a doctor blade for scraping off ink supplied excessively to the surface of a gravure printing plate cylinder from the plate surface.

  Conventionally, as a method of polishing the doctor blade for scraping off the excessive ink supplied to the surface of the gravure printing plate cylinder from the plate surface, an operator uses a grindstone or a file in the printing unit. A method of manually polishing is performed. However, in the manual polishing, the polishing finish varies depending on the skill level of the operator, the polishing condition in the longitudinal direction of the doctor blade varies, and the printing density of the printed matter varies. Furthermore, there is a problem that there is a danger in the polishing operation and that the polishing operation takes time.

Therefore, an invention of a doctor blade polishing apparatus that has a self-propelled polishing head capable of reciprocating along a doctor fixed on a base and automatically polishes a doctor blade is disclosed (Patent Document 1). . However, the polished surface polished using the doctor polishing apparatus and the actual printing plate surface do not coincide with each other, and during printing, the contact area between the doctor blade and the plate surface changes due to wear of the doctor blade, so that the printing density is changed over time. There is a problem of changing. In addition, there has been proposed a printing machine including a member for polishing a doctor blade at a position having a height difference with respect to a cylinder peripheral surface (Patent Document 2). However, there is a problem in that poor printing quality is caused by mixing of doctor blade wear powder generated by polishing into ink and uneven polishing due to adhesion to the doctor blade. Moreover, the invention of the cylinder type grindstone which has the grinding | polishing surface for grind | polishing a doctor blade on the surrounding surface of a cylinder type main-body part, and the doctor blade grinding | polishing apparatus and method provided with the said cylinder type grindstone is disclosed (patent document 3). . The polished surface is laid with a fine abrasive grain powder, and very fine doctor blade polishing is possible. However, the abrasive powders arranged in the polishing surface and adjacent to each other are not completely in close contact with each other, and there are fine gaps. The abrasion powder of the doctor blade adheres and remains in this gap, causing uneven polishing. As a result, there is a problem in that poor print quality occurs due to uneven polishing.
JP 04-372350 A Japanese Patent No. 3608276 JP 2006-75926 A

  The present invention has been made to solve the above problems. The purpose is that the skill level of the operator is not required, the contact area does not change with time due to the wear of the doctor blade edge, so the printing density does not change with time, the contamination of the abrasion powder generated by polishing and the remaining This is to prevent printing quality defects caused by uneven polishing due to wear powder. And it is providing the doctor blade grinding | polishing apparatus etc. for that.

A doctor blade polishing apparatus according to the present invention is a cylinder type grindstone similar to the outer shape of a gravure cylinder in a doctor blade polishing apparatus for polishing a doctor blade of a doctor for scraping off ink supplied excessively to the surface of a gravure printing plate cylinder Polishing means provided on the peripheral surface of the cylinder grindstone, rotation drive means for rotationally driving the cylinder-type grindstone, means for movably supporting the doctor blade, and pressing the doctor blade against the polishing section And removal means for removing doctor blade wear powder remaining in the polishing section.
A doctor blade polishing method according to the present invention is a doctor blade polishing method for polishing a doctor blade of a doctor for scraping ink supplied excessively to the surface of a gravure printing plate cylinder. Rotation driving process for rotationally driving a cylindrical grindstone having a polishing part on the peripheral surface, a support process for movably supporting the doctor blade, and a polishing process for pressing the doctor blade against the polishing part and polishing the doctor blade And a removing step of removing the abrasion powder by bringing a removal tool for removing the doctor blade abrasion powder adhering to the polishing section into contact with the polishing section.

According to the doctor blade polishing apparatus according to the present invention, since the polishing surface coincides with the peripheral surface of the gravure cylinder, the contact area does not change with time due to wear of the doctor blade edge during printing. In addition, since the doctor blade abrasion powder adhering to and remaining on the polished surface is removed, polishing unevenness of the doctor blade can be prevented, and deterioration in printing quality can be prevented.
Moreover, according to the doctor blade grinding | polishing method which concerns on this invention, since a grinding | polishing surface corresponds with the gravure cylinder surrounding surface, a contact area does not change with time by abrasion of a doctor blade edge | tip at the time of printing. In addition, since the doctor blade abrasion powder adhering to and remaining on the polished surface is removed, polishing unevenness of the doctor blade can be prevented, and deterioration in printing quality can be prevented.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view showing an example of a mode of polishing a doctor blade using a cylindrical grindstone 50 having a polishing portion on the peripheral surface in the doctor blade polishing apparatus of the present invention. FIG. 2 is a schematic top view of the doctor polishing apparatus shown in FIG. 3 is a schematic cross-sectional view (AA of FIG. 2) of the doctor polishing apparatus shown in FIG. FIG. 4 is a top view showing an example of the removing means in the doctor blade polishing apparatus of the present invention. FIG. 5 is a cross-sectional view (BB in FIG. 4) showing an example of the removing means in the doctor blade polishing apparatus of the present invention.

  The doctor holder 10 is a member that sandwiches the doctor blade 100 between two metal plates. These two metal plates are a holder upper plate 11a and a holder lower plate 11b as shown in FIG. The doctor blade 100 is attached to and detached from the doctor blade polishing apparatus in an integrated state sandwiched by the doctor holder 10. The doctor holder 10 can be used as a dedicated support tool for the doctor blade polishing apparatus, and can be used as a dedicated support tool for a gravure printing machine using the doctor blade 100. Accordingly, it is easy to make the polished surface of the doctor blade coincide with the gravure printing plate surface, and the work load for adjusting and holding the doctor blade 100 on the doctor holder 10 is reduced, which is preferable.

  The doctor mount 20 includes a holding mechanism for holding and fixing the doctor holder 10, and front and rear adjustment mechanisms 30 a and 30 b with respect to the longitudinal direction of the doctor blade 100.

  The front and rear adjustment mechanisms 30a and 30b are, for example, a threaded rod member that contacts the rear part (side opposite to the blade edge of the doctor blade 100) in the doctor holder 10, and a screw hole fixed to the doctor mount 20 that supports the threaded rod member. It comprises a member and a front / rear adjustment handle 31a, 31b for manually rotating a threaded rod member. The front / rear adjustment mechanisms 30a, 30b have a mechanism for rotating the front / rear adjustment handles 31a, 31b by an operator to bring the doctor blade 100 closer to or away from the cylinder-type grindstone 50.

  The vertical adjustment mechanism 40 is a mechanism for adjusting the vertical position of the doctor mount 20. For example, as the vertical adjustment mechanism 40, a well-known linear movement mechanism, an arm and its rotation mechanism provided between the frame of the doctor blade polishing apparatus and the doctor mount 20 can be applied.

  By the above-described front / rear adjustment mechanisms 30a, 30b and the vertical adjustment mechanism 40, a polishing operation is performed that satisfies substantially the same contact angle condition as the angle at which the doctor blade 100 contacts the plate surface of the actual printing plate cylinder. As a result, the polished surface of the doctor blade and the actual printing plate surface coincide with each other, and it is possible to eliminate the change with time of the printing density due to the change with time of the contact angle and the contact area between the doctor blade and the plate surface.

The cylinder-type grindstone 50 provided with a polishing portion on the peripheral surface is a cylinder and a cylinder similar to the outer shape of the gravure printing plate cylinder, and a polishing portion to which polishing abrasive powder is fixed is provided on the peripheral surface. To polish. In addition, about the manufacturing method of a cylinder grindstone, since it is disclosed by patent document 3, description is abbreviate | omitted in this specification.
The cylinder shape may be either a cylinder with a shaft with a shaft or a cylinder without a shaft (sleeve cylinder). When the cylinder-type grindstone 50 is a shaft-equipped cylinder, the doctor polishing device includes a shaft-cylinder bearing. When the cylinder-type grindstone 50 is an axisless cylinder, the doctor blade polishing apparatus is provided with a chucking mechanism including a chucking cone. In any cylinder shape, the doctor blade polishing apparatus includes a rotation mechanism that rotates the cylinder-type grindstone 50 at a predetermined rotation speed.

The cylinder-type grindstone 50 has polishing abrasive grains laid on the peripheral surface thereof, and the peripheral surface serves as a polishing portion. The abrasive grain powder is spread, for example, at a density of 6000 pieces / inch ² .

  The doctor blade 100 is a thin plate for scraping off ink supplied excessively to the plate surface of the gravure cylinder, and is generally made of metal or ceramic. Usually, it has a thickness of, for example, 0.01 mm to 1.0 mm, bends when pressed, adheres to and adheres to the plate surface.

The abrasion powder of the doctor blade 100 adheres and remains on the surface of the cylinder-type grindstone 50 by polishing the doctor blade. In the doctor blade polishing apparatus, the removing means is constituted by a base jig provided to face the doctor holder 10, a removing tool 200 attached to the base jig, and means 130 for pressing the removing tool against the polishing portion. Is done.
The means for moving in parallel with the longitudinal direction of the cylinder type grindstone 50 is constituted by a driving means 160 provided at the end with a base jig attached to the left and right linear motion guides 110a, 110b made of, for example, ball screws. For example, a motor can be used as the driving means.
As a means for removing the abrasion powder from the polished surface, for example, a brush is used. The brush covering a certain removal area is used, and the wear powder adhering to the circumferential surface of the cylinder-type grindstone can be removed by scanning in the longitudinal direction of the cylinder-type grindstone with the left-right linear guide and driving means. Further, by using a brush that covers the entire inside of the predetermined removal area, it is possible to remove the abrasion powder in the predetermined removal area without scanning, and the working time can be shortened. Means for pressing the removal tool against the polishing section includes an air cylinder and front / rear linear motion guides 120a and 120b. The removal tool is moved to the attaching / detaching position with respect to the cylinder-type grindstone by the air cylinder 130 along the front-rear linear motion guides 120a, 120b, and the brush can be brought into direct contact with the cylinder-type grindstone 50 while being pressurized. Although not indicated in the drawings, the base jig can be moved along the left and right linear guides 110a and 110b, and is a mount on which a removal tool can be attached and an air cylinder can be mounted.
The present application is not limited to the above configuration. Further, the positional relationship between the doctor holder and the removing means does not necessarily have to be opposed to each other, and the removing means only needs to be located at a position where the polishing surface can be removed to satisfy the effects of the present invention with a removing tool. This is one mode.

  Lubricating water is supplied to the submerged part installed below in the process of removing abrasion powder. The lower surface of the grinding part of the cylinder type grindstone is immersed in the lubricating water. With the brush, the abrasion powder is scraped off from the polishing surface supplied with the lubricating water, and the abrasion powder floating from the polishing section is again washed in the immersion section and washed away from the polishing section. As a result, the abrasion powder can be more reliably removed.

Next, an example of the operation of the doctor blade polishing apparatus of the present invention in the above configuration will be described with reference to FIG. FIG. 6 is a flow chart showing an example of the process of removing the doctor blade polishing and doctor blade wear powder in the doctor blade polishing apparatus of the present invention.
(1) Polishing preparation (step S1)
First, the doctor blade 100 before polishing is fixed to a doctor holder 10 dedicated to a gravure printing machine that will perform printing. The doctor holder 10 on which the doctor blade 100 is held and fixed is attached to the doctor blade polishing apparatus of the present invention. At this time, it is assumed that the cylinder-type grindstone 50 is previously installed in the doctor polishing apparatus. Moreover, when not installing beforehand, mounting | wearing to the doctor blade grinding | polishing apparatus of the cylinder type grindstone 50 shall be performed before this step.

(2) Polishing condition setting (step S2)
Next, the operator sets polishing conditions excluding the polishing angle in the doctor blade polishing apparatus. Examples of the polishing conditions include a doctor pressure, a polishing time, and a rotational speed of a cylinder-type grindstone.

(3) Polishing angle setting (step S3)
The operator sets the polishing angle in the doctor blade polishing apparatus. The polishing angle is set so that the polishing surface of the doctor blade 100 brought into contact with the plate surface when printing is made coincident with the plate surface. The polishing angle is set by adjusting the above-described front and rear adjustment mechanisms 30a and 30b and the vertical adjustment mechanism 40, and adjusting the relative positional relationship between the cutting edge of the doctor blade 100 and the peripheral surface of the cylinder-type grindstone 50. Set.

(4) Polishing (Step S4)
The operator presses the polishing start button on the operation panel of the doctor polishing apparatus. As a result, the cylinder rotation mechanism operates, the cylinder type grindstone 50 accelerates while rotating, and the constant speed operation starts at the set rotation speed. In this state, the doctor cradle 20 is displaced from the detached position to the worn position, and the doctor blade is brought into contact with the rotating cylinder-type grindstone 50 to polish the blade edge. The polishing operation is stopped after a certain period of time. This stopping operation may be a flow of decelerating and stopping the rotational speed of the cylindrical main body portion by putting the doctor blade at the landing position in a disengaged state and applying a brake to the rotation mechanism, or vice versa. In view of work efficiency, the cylinder-type grindstone 50 may be shifted to the next step while maintaining the rotation state.

(5) Doctor removal (S5)
The operator removes the doctor holder 10 on which the doctor blade is held and fixed from the doctor blade polishing apparatus of the present invention. Since the abrasion powder adheres to the polished surface of the doctor after the polishing operation by polishing in the above step, it is removed by wiping with a nonwoven fabric or the like.

(6) Preparation for removal (step S6)
The operator presses the removal start button on the operation panel of the doctor polishing apparatus. As a result, lubricating water 180 is prepared in a tray 170 provided below the cylinder-type grindstone 50, and the lower surface of the cylinder-type grindstone is immersed in the lubricating water as shown in FIG. Examples of the lubricating water include water filtered with a filter or the like. The air cylinder 130 acts on the cylinder-type grindstone 50 in a rotating state (when the cylinder-type grindstone 50 is in a stopped state, the rotation of the cylinder-type grindstone 50 is started), and the brush moves from the disengagement position to the landing position. The cylinder-type grindstone 50 is in direct contact with the polishing portion.

(7) Wear powder removal (step S7)
The brush 200 in contact with the polishing portion of the cylinder-type grindstone 50 is scanned in the predetermined removal area according to the left-right linear motion guides 110a and 110b. In order to remove the wear powder adhering to the circumferential surface of the cylinder-type grindstone 50 evenly, for example, a method of moving and scanning within the removal region at regular intervals can be mentioned.

(8) Stop operation (step S8)
The operator presses the stop button on the operation panel of the doctor blade polishing apparatus. As a result, the scanning of the brush 200 is finished, the brush 200 moves from the wearing position to the detached position, and the operation of the rotation driving means is stopped.
Also, the doctor blade polishing and the abrasion powder removal work from the cylinder grinding wheel surface may be such that the operation time is set in advance and automatically ended by a timer mechanism. The operation of the doctor blade polishing apparatus and the doctor blade polishing method according to the present invention are not limited to the above steps.

By the above steps, polishing of the doctor blade 100 held by the doctor holder 10 is completed, and a polishing surface that matches the actual printing plate surface is formed on the blade edge of the doctor blade. Further, the abrasion powder of the doctor blade adhering to and remaining on the polishing portion provided on the circumferential surface of the cylinder type grindstone 50 is removed by the removing means. Therefore, the variation in the degree of polishing of the doctor blade polishing surface can be eliminated, and gravure printing with few quality defects becomes possible.

It is the schematic which shows an example when grind | polishing using a cylinder type grindstone in the doctor blade grinding | polishing apparatus of this invention. It is a top view which shows an example of the grinding | polishing part in the doctor blade grinding | polishing apparatus of this invention. It is sectional drawing which shows an example of the grinding | polishing part in the doctor blade grinding | polishing apparatus of this invention. It is a top view which shows an example of the removal means in the doctor blade grinding | polishing apparatus of this invention. It is sectional drawing which shows an example of the removal means in the doctor blade grinding | polishing apparatus of this invention. It is a flowchart which shows an example of the process of grinding | polishing and abrasion powder removal in the doctor grinding | polishing apparatus of this invention.

Explanation of symbols

10 Doctor holder 11a Holder upper plate 11b Holder lower plate 20 Doctor mount 30a, 30b Front / rear adjustment mechanism 31a, 31b Front / rear adjustment handle 40 Vertical adjustment mechanism 50 Cylinder type grindstone 100 Doctor blades 110a, 110b Left / right linear motion guides 120a, 120b Guide 130 Air cylinder 140 Ball screw 150 Coupling 160 Driving means 170 Receptacle 180 Lubricating water 200 Remover

Claims (5)

In the doctor blade polishing device that polishes the doctor blade of the doctor for scraping off the excessive ink supplied to the surface of the gravure printing plate cylinder,
A cylinder-type grindstone that resembles the outer shape of a gravure cylinder;
A polishing portion provided on a peripheral surface of the cylinder-type grindstone;
Rotation driving means for rotating the cylinder type grindstone,
Means for movably supporting the doctor blade and pressing the doctor blade against the polishing section;
A doctor blade polishing apparatus comprising: removal means for removing doctor blade wear powder remaining in the polishing section.   The doctor blade polishing apparatus according to claim 1, wherein the polishing portion is a polishing surface to which polishing abrasive grains are fixed.   The removal means comprises a base jig capable of reciprocating in parallel with the longitudinal direction of the cylinder type grindstone, a removal tool attached to the base jig, and means for pressing the removal tool against the polishing section. The doctor blade polishing apparatus according to claim 1 or 2, In the doctor blade polishing method for polishing the doctor blade of the doctor for scraping off the excessive ink supplied to the surface of the gravure printing plate cylinder,
Rotation drive process that rotationally drives a cylinder-type grindstone that resembles the outer shape of the gravure cylinder and has a polishing portion on its peripheral surface;
A supporting step for movably supporting the doctor blade;
A polishing step of pressing the doctor blade against the polishing portion and polishing the doctor blade;
A removal method of removing a wear powder by bringing a removal tool that removes the doctor blade wear powder adhering to the polishing section into contact with the polishing section.   The removing step is performed using a removing tool attached to a base jig that can reciprocate substantially parallel to the longitudinal direction of the cylinder-type grindstone, and pressing the removing tool against the polishing unit. The doctor blade polishing method according to claim 4.

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