JPH0747829B2 - Etching method for rolling rolls - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method and an apparatus for etching a cast iron rolling roll for forming innumerable irregularities on a surface of a rolling roll in an accurate pattern.

[Conventional technology]

Generally, as a method of etching a roll, a method of immersing the roll in a container filled with the etching solution and a method of spray-coating the etching solution on the roll are known.

An example of the dipping method is disclosed in Japanese Patent Laid-Open No. 1-283389.
Roll 1 into the etching solution 6 that fills a shallow dish as shown.
There is disclosed a method of immersing and rotating only the body part of the. As an example of the method of spray coating, there is JP-A-60-23975.
Japanese Patent Publication No. 3 discloses a method of spraying an etching solution onto the roll surface from a plurality of nozzles while slowly rotating the roll, as shown in FIG. 3 or FIG.

A method for roughening the surface by etching has been conventionally performed, and for example, Japanese Patent Publication No. 42-9452 and Japanese Patent Publication No. 4-2896.
There is a technique of applying a pattern to the surface of a roll by electrolytic etching, as proposed in Japanese Patent Publication No. 8.

In such a technique, one roll is used to remove oil stains on the surface, an etching resist is applied, and this is dried, and then a film having a predetermined pattern composed of a transparent portion and a black portion is formed. The roll is adhered to the roll, wound, exposed to light, and further developed, etched, and resist stripped to produce a patterned roll.

Further, as another method, as proposed in Japanese Patent Laid-Open No. 2-175882, a resin film is formed by applying a corrosion-resistant resin liquid mixed with a light absorber, and a resin is formed using a Q-switch YAG laser. There is a method of vaporizing and removing a part of the film, then spraying an etching solution on the roll surface, and then peeling the resin film to give a pattern to the roll surface.

[Problems to be Solved by the Invention]

The conventional etching methods of the above two examples have the following problems.

The etching rate (etching depth / etching time) is small and it takes time to etch.

Because the etching progresses relatively in the same direction,
The etch factor (etching depth d / undercut c) shown in the figure is unlikely to be 2 or more as the actual value. That is, as the etching depth d increases as the etching progresses, the undercut c also increases to about the same extent, so that an etching portion larger than the void (predetermined pattern) size of the mask 8 in FIG. Since the etching depth d is larger, the etching accuracy is reduced as the difference between the predetermined pattern size and the size of the generated etching portion is increased.

FIG. 5 is an explanatory view showing an example in which the mask 8 is placed on the processing material 7 to perform etching.

As a countermeasure against this, a technique called "centrifugal force etching" is known. For example, "Theory and technical trend of wet etching"
(Toshikazu Sato Practical Surface Technology vol.35, No.11,1988 P2-P1
According to (0), as shown in FIG. 6, the workpiece 7 is immersed in the container 6 filled with the etching solution, and the container 6 is attached to the shaft 11 like the container 6a shown by the broken line in FIG. Rotate around 12
Then, a negative gravitational field is generated on the etched surface. In this gravitational field, a large gravitational difference is generated with respect to a slight difference in the density of the etching liquid before and after the chemical reaction, so that convection in the depth direction of the etching liquid is enhanced. Along with that, the etching rate is improved and the etch factor is increased.

The disadvantage of this method is that the entire container 6 containing the etching liquid in which the material to be processed is stored must be rotated at a high speed, so that when the material to be processed is large, the entire apparatus such as the container becomes very large. Is.

The present invention provides an extremely simple method that does not require an immersion container when centrifugal force etching is applied to a cylindrical work material.

[Means for Solving the Problems]

In order to solve the above problems, the present invention provides unevenness by etching on the surface of a cast iron roll, while applying an etching solution containing ferric chloride to the roll surface,
A method for etching a rolling roll, which comprises rotating the roll around a roll axis so that a centrifugal force of 5 g (g is the acceleration of gravity) or more acts on the surface of the roll.

The centrifugal force F was calculated by the following formula.

F = v ² /(r×9.8) where F: centrifugal force (g) v: roll peripheral velocity (m / sec) = 2πr · n / 60 r: roll radius (m) n: roll speed (rpm) ) Is.

[Action]

 The method and apparatus of the present invention have the following functions.

(1) Since an etching solution containing ferric chloride is spray-coated on a cast iron rolling roll, a large immersion container is not required.

(2) Since only the cast iron rolling roll is rotated in order to apply the centrifugal force, a device for rotating the container may be smaller than that for rotating the entire container.

(3) The centrifugal force generated on the surface of the cast iron rolling roll is set to a value of 5 g or more (g is the acceleration of gravity) from the experimental results shown in FIG. FIG. 7 is data obtained by centrifugally etching a cast iron rolling roll having an outer diameter of 150 mm and a body length of 200 mm with a 41 wt% aqueous solution of ferric chloride as an etching solution by the apparatus of FIG.
It shows the relationship of the influence of the roll rotation speed on the etching factor. The centrifugal force generated on the roll surface is proportional to the roll rotation speed. The etching factor increases as the centrifugal force increases. Theoretically, when a centrifugal force of 1 g or more acts, the etching factor becomes 2 or more, but in the present invention, the centrifugal force is limited to 5 g or more in order to ensure 2 or more. The centrifugal force was calculated from the radius of the cast iron rolling roll used and the number of revolutions at that time.

〔Example〕

FIG. 1 shows an apparatus according to an embodiment of the present invention. A spray nozzle 2 as a coating machine for applying the etching liquid to the surface of the roll 1.
And a fixture 5 supporting it is shown. An etching solution tank, a pump, piping, etc., which are not shown, are attached. The coating machine is moved in the axial direction of the roll 1 by the traverse device 3. A drive device 4 for rotating the roll 1,
A rotation control device 10 is provided.

A film with a light absorbing material is applied by spray coating on the surface of a cast iron rolling roll 1 (outer diameter 150 mm, body length 150 mm) to a film thickness of 10
Apply to less than μm.

The resin on the roll surface is processed into a target pattern by controlling the YAG laser light. In this case, the resin in the laser light irradiation portion is evaporated and the metal surface of the roll is exposed.

By this method, the resin on the entire surface of the roll is processed into a desired pattern, and the roll 1 is set in the apparatus shown in FIG. This pretreatment can also be performed by a method using a mask film.

The surface (exposed metal portion) of the roll 1 was applied by using a 41 wt% aqueous solution of ferric chloride as an etching solution using a spray nozzle 2, and the roll 1 was rotated to perform centrifugal etching with the apparatus shown in FIG.

The etching liquid is sprayed onto the roll surface by the spray nozzle 2. This nozzle is a two-fluid nozzle and uses air as assist gas. The air flow rate at this time is
It was set to 30 l / min. The spray angle is 90 °, and the distance from the nozzle tip to the roll surface is 50 mm. Further, the nozzle 2 repeats reciprocating motion in a direction parallel to the roll cylinder length at a speed of 480 mm / min by the traverse device 3 via the spray nozzle fixture 5.

The roll 1 is supported by a driving device 4 having a built-in bearing for high speed rotation, and its rotation can be controlled from 0 to 2000 rpm.

The results of centrifugal etching with the apparatus of FIG. 1 are shown in FIG. 8 as a comparative example and in FIG. 9 as an example of the present invention. This is a three-dimensional roughness profile diagram of the roll surface after etching. The deeper the centrifugal force, the deeper and sharper the uneven surface becomes. That is, as shown in FIG. 8, when the centrifugal force is 0.076 g, the depth SRz of the recess due to etching is larger when the centrifugal force is 83.84 g as shown in FIG. 9, and the etching rate is larger. Become. On the other hand, one of the etching factors has a centrifugal force of 0.
In case of 076 g, it is 1.5, and as shown in FIG. 9, centrifugal force is 83.
It is 2.8 for 84g. In this case, the etching time was set to 10 minutes in both the comparative example and the present invention example.

〔The invention's effect〕

In the present invention, the etching solution containing ferric chloride is spray-coated while rotating the roll so that a centrifugal force exceeding 5 g (g is the acceleration of gravity) acts on the surface of the cast iron rolling roll. And centrifugal force etching is now possible without the need for a large container for the roll. According to the present invention, an etching factor of two or more, which cannot be obtained by the conventional etching method, can be obtained, and the etching accuracy is further improved. Further, since the etching rate is increased, there is also an effect that the etching time is shortened.

[Brief description of drawings]

FIG. 1 shows an apparatus according to an embodiment of the present invention (a) is a plan view,
(B) is an elevational view, FIG. 2 is a perspective view showing a conventional dipping method device, FIGS. 3 and 4 are explanatory views showing a conventional spray coating method, FIG. 5 is an explanatory view of an etch factor, FIG. 6 is an explanatory view showing the conventional centrifugal etching method, FIG. 7 is a graph showing the relationship between centrifugal force and etching factor, FIG.
FIG. 9 is a three-dimensional profile diagram of the roll surface showing the effect of centrifugal force. 1 ... Roll 2 ... Spray nozzle 3 ... Traverse device 4 ... Drive device 5 ... Spray nozzle fixture 6 ... Etching liquid 7 ... Processing material 8 ... Mask 9 ... Material holder 10 ... Rotation control Device 11 …… Axis 12 …… Rotate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takaaki Hira 1 Kawasaki-cho, Chiba-shi, Chiba Inside Kawasaki Steel Co., Ltd. Technical Research Headquarters (56) Reference JP-A-60-239753 (JP, A) JP-A-2 -8377 (JP, A) JPB 52-24507 (JP, B2)

Claims (1)

[Claims] 1. When imparting unevenness to a surface of a cast iron roll by etching, while applying an etching solution containing ferric chloride to the roll surface, a centrifugal force of 5 g (g is the acceleration of gravity) or more is applied to the roll surface. A method for etching a rolling roll, which comprises rotating the roll around a roll axis so that force acts.