JPH11256493A - Doctor blade of doctoring equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a doctor blade suitable for doctoring a flexible surface of a roll such as a pressure roll or the like. SOLUTION: This doctor blade 2 of a doctoring equipment has a two-layer structure consisting of the first plate material 20 made of polyethylene resin and the second plate material 30 made of stainless steal. The first plate material 20 has a nose 21, a thin tip part 22, a tapered part 23 and a thick body part 24. The overall rigidity of the doctor blade 2 is secured by the second plate material 30 and the flexibility of the nose 21 does not injure the surface of the roll. Consequently the nose 21 is pressed against the surface of the roll through a sufficient linear pressure, and can form the good hit state by the edge against the surface of the roll, which can lead the excellent doctoring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a doctor device used for scraping off foreign substances adhering to a roll surface such as a roll for iron making such as a rolling roll and a roll for a paper machine, and more particularly to a doctor blade for the doctor blade. It is about improvement.

[0002]

2. Description of the Related Art Conventionally, as a doctor device for a paper machine roll, a blade of a doctor blade having substantially the same length as the roll surface is pressed against the roll surface with an appropriate linear pressure, and the roll is rotated in this state. Thus, a material configured to scrape foreign matter from the roll surface is used.

As a doctor blade of a doctor device used for a paper machine roll, a material of a soft material is known. For example, a material using a polyethylene resin as a base material is known. Such a synthetic resin material has a lower rigidity than a composite material containing glass fiber, and thus is generally thicker than a material having a high rigidity and is set to a thickness of about 3 mm to about 6 mm. . With such a thickness, the pressing force (linear pressure) of the cutting edge against the roll surface can be sufficiently ensured. In a paper machine roll, the linear pressure is generally set to about 300 to 400 g.

[0004] Here, a large number of rolls such as rolling rolls are also used in the steelmaking industry. Even with these rolls, if foreign matter such as dust adheres to the surface of the roll, problems such as formation of irregularities on the surface of the formed sheet occur. As a method for removing foreign matter adhering to the surface of the rolling roll, a method using a brush roll, a method of reciprocating a brush along the roll surface, and the like are generally adopted.

[0005] In such a method, it is difficult to reliably remove the foreign matter adhering to the roll surface. Therefore, it is conceivable to use the above-described doctor device to scrape off foreign substances attached to the surface of the steelmaking roll. However, in the doctor device used for the paper machine roll, the pressing force of the blade of the doctor blade is about 300 g to 400 g.
g, but about 20 to 20 for steelmaking rolls.
It may be about 0 g. In general, ironmaking rolls are formed of a material softer than a paper machine roll, and when a high linear pressure is applied, adverse effects such as scratches on the roll surface occur. Therefore, the doctor blade of the doctor device used for the steelmaking roll is preferably made of a soft material such as polyethylene resin.

However, when a doctor blade made of a soft material is used, the doctor blade becomes thick in order to secure required rigidity. That is, if the doctor blade made of a soft material is thinned, its out-of-plane rigidity is reduced and the whole is curved, so that a sufficient pressure contact force cannot be applied to the blade edge. When a thick doctor blade is used as it is, the doctoring performance is inferior to that of a thin doctor blade. Further, when a thick doctor blade is used, the bending habit of the doctor blade itself directly affects the roll surface. If a hard doctor blade is used, this problem can be solved because it can be made thinner.However, as described above, the steelmaking roll surface is soft. Resulting in.

On the other hand, when doctoring the surface of a paper machine roll or a hard roll, when a doctor blade is manufactured from a hard material, for example, a material containing a metal plate or glass fiber, a thinner blade has a smaller doctor ring. Although the performance is good, if it is made too thin, the overall rigidity becomes insufficient, and the blade edge cannot be pressed against the roll surface with a sufficient linear pressure.

Therefore, the present inventor has disclosed in Japanese Patent Laid-Open No.
Japanese Patent No. 44187 proposes a doctor blade capable of performing excellent doctoring without damaging the roll surface. As shown in FIG.
The doctor blade 10 has a thin tip portion 12 on which a cutting edge 11 is formed, a main body portion 13 having a thickness of about twice or more the thickness of the front end portion 12, and a gradually increasing thickness between the front end portion 12 and the main body portion 13. And a tapered portion 14 having a cross section. By making the doctor blade have such a cross-sectional shape, even when the doctor blade is formed of a soft material such as polyethylene resin, the entire out-of-plane rigidity can be sufficiently ensured, and a good doctor ring can be obtained with a thin blade edge. be able to. Therefore, excellent doctoring can be performed without adverse effects such as damaging the surface of the soft steelmaking roll.

[0009]

However, as shown in FIG. 4, the force for pressing the cutting edge 11 of the doctor blade 10 against the roll surface 101 is reduced by the metal blade on the side of the blade holder 15 holding the doctor blade 10. It is given by pressing the leading edge 16a of the top plate 16 against the upper surface of the main body portion 13 of the doctor blade 10. As described above, since a concentrated load acts on the doctor blade 10 from the side of the blade holder 15, even if the body portion 13 of the doctor blade 10 is thickened, the entire rigidity may not be sufficiently secured in some cases.

If the overall rigidity of the doctor blade 10 cannot be ensured, the blade edge 11 cannot be pressed against the roll surface 101 with a sufficient linear pressure, so that sufficient doctor ring cannot be performed.

It is an object of the present invention to provide a doctor blade of a doctor device which can perform excellent doctoring with a thin blade and can press the blade against a roll surface with a sufficient pressing force.

[0012]

In order to solve the above-mentioned problems, the present invention relates to a doctor apparatus for pressing a doctor blade against the surface of a rotating roll to scrape foreign substances adhered to the surface of the roll. A laminated structure comprising: a first plate member having a blade edge formed by pressing the doctor blade at the tip thereof against the roll surface; and a second plate member made of a different material laminated and fixed on the surface of the first plate member. It is characterized by having.

In the present invention, the doctor blade has a two-layer structure. Therefore, if the first plate member on which the cutting edge is formed is formed of a soft material and the side of the second plate member on which the pressing force for pressing the doctor blade against the roll surface is formed of a hard material is formed of a hard material, By pressing the blade edge of the blade against the roll surface with a sufficient linear pressure, excellent doctoring can be performed. Further, since the blade edge of the doctor blade is formed of a soft material, it does not damage the roll surface. Furthermore, since the soft first plate is reinforced by the hard second plate,
The first plate can be made very thin.

Here, in the doctor blade of the present invention as well, as the first plate member, a main body portion, a tip portion thinner than the main body portion, and a tapered shape formed between the main body portion and the tip portion. And a configuration in which the cutting edge is formed at a tip edge of the tip portion. According to this configuration, a doctor blade excellent in doctoring characteristics can be realized by a synergistic effect of the operation effect of the doctor blade proposed by the present applicant and the operation effect of the doctor blade according to the present invention.

In this case, it is desirable that the length from the tip of the cutting edge to the tapered portion at the tip of the first plate is set to a value within the range of 3 mm to 7 mm. With this configuration, when the first plate member is formed using a synthetic resin material that is a commonly used material of a doctor blade, the bending of the tip portion where the cutting edge is formed does not cause any practical problem. Range.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a doctor device provided with a doctor blade to which the present invention is applied will be described.

FIG. 1 shows the overall configuration of a doctor device, and FIG. 2 shows the cross-sectional shape of a doctor blade. As shown in FIG. 1, a doctor device 1 comprises an elongated rectangular doctor blade 2 having a cutting edge pressed against a roll surface, and a blade holder 3 holding a base end side thereof.
And a doctor back 4 supporting the blade holder 3. The doctor back 4 is rotatably supported by bearings on a stand (not shown) on which journal shafts 4a attached to both ends are fixedly arranged. A turnbuckle (not shown) is connected between the doctor back 4 and the gantry, and by adjusting this, the doctor back 4 can be fixed at an arbitrary rotational position.

The blade holder 3 is supported by the doctor back 4 so as to be rotatable about the connecting rod 3a. A tube 5 for opening the blade is arranged on the front side of the connecting rod 3a, and a tube 6 for pressing the blade is arranged on the rear side. These tubes 5,
6 is formed of a flexible material, and when the tube 5 side is expanded, the blade holder 3 holding the doctor blade 2 moves the doctor blade 2 away from the surface of the roll R around the connecting rod 3a. That is, it turns in the opening direction. When the other tube 6 is inflated, the blade holder 3 pivots in a direction to press the doctor blade 2 against the surface 101 of the roll 100, that is, in a pressing direction.

The expansion and contraction of these tubes 5 and 6 are as follows:
These are performed by controlling the supply of air. That is, the air supply path from the air source 7 communicates with the tubes 5 and 6 via the pressure adjusting valve 8 and the four-way switching valve 9. When the switching valve 9 is set to the switching position shown in the figure, the pressurizing tube 6 expands. When the switching valve is switched, the opening tube 5 expands.

Referring to FIG. 2, the structure and material of the doctor blade 2 used in this embodiment will be described. The doctor blade 2 includes a first plate member 20 having a cutting edge 21 formed at the tip thereof and pressed against the roll surface 101, and a second plate member 30 made of a different material laminated and fixed on the surface of the first plate member 20. It has a two-layer structure.

The first plate member 20 is formed with a main body portion 23 having a constant thickness, a tip portion 22 having a constant thickness smaller than the main body portion 23, and between the main body portion 23 and the tip portion 22. And a tapered portion 24 whose thickness gradually decreases toward the tip portion 22. The tip edge of the tip portion 22 is a cutting edge 21. A concave portion 25 is formed in the rear end portion of the main body portion 23 and is pressed and fixed by a leaf spring or the like so as not to come off from the blade holder 3 side.

In the present embodiment, the main body 24 of the first plate 20
The second plate member 30 is laminated and fixed to a portion of the surface 24a.

Here, the first plate member 20 is formed of polyethylene resin which is a generally used soft material. On the other hand, the second plate 30 is made of a metal material, for example, stainless steel.

The dimensions of each part of the doctor blade 2 are as follows. First, the cutting edge 21 has an acute angle of about 30 degrees. The tip portion 22 continuing to the cutting edge has a thickness of 2 mm, and the body portion 24 has a thickness of 5 mm. The length of the tip portion 22, that is, the length from the cutting edge 21 to the tapered portion 23 is 5 mm. The overall width of the doctor blade 2 having such a cross-sectional dimension is 76 mm.

According to the experiments of the present inventor, this tip portion 2
It has been confirmed that it is preferable to set the length of 2 between about 3 mm and about 7 mm. Further, when the doctor blade 2 of this example was used and the linear pressure was set at about 50 to 100 g / cm and the surface of the iron making roll was doctored, good results were obtained.

As described above, the doctor blade 2 of the doctor device 1 of the present embodiment has a two-layer structure including the first plate member 20 made of polyethylene resin and the second plate member 30 made of stainless steel. The first plate member 20 includes a cutting edge 21, a thin tip portion 22, a tapered portion 23, and a thick body portion 24. The overall rigidity of the doctor blade 2 can be ensured by the second plate 30 and the blade edge 2
1 is soft and does not damage the roll surface. Therefore, the blade edge 21 can be pressed against the roller surface 101 with a sufficient linear pressure, and a favorable blade contact state with respect to the roll surface can be formed, so that excellent doctor ring can be realized.

In the above example, the present invention is applied to a doctor blade for a steelmaking roll. However, the present invention can be similarly applied to other doctor blades for rolls.

Further, for example, a material formed of a synthetic resin composite material containing glass fiber can be used as the first plate material, or a metal material can be used. In this case, as shown in FIG. 3, the first plate member 20A has high rigidity, so that a plate member having a constant thickness can be used as a whole, and the tip of the plate member may be formed at an acute angle to be a cutting edge. The second plate member 30A is set back by a fixed distance so that the roll surface is not damaged when the cutting edge of the first plate member 20A is worn, so that the first plate member 20A
What is necessary is just to laminate and fix it on the surface of.

The first plate and the second plate can be integrated using, for example, an adhesive. When both are made of a synthetic resin material, they may be integrally molded. When one plate is a metal plate and the other is a resin plate, the molding may be performed with the metal plate inserted when the resin plate is molded.

[0030]

As described above, the doctor blade of the doctor device of the present invention has a structure in which the first plate made of a soft material and the second plate made of a hard material are laminated and fixed. Therefore, by appropriately setting the properties such as the bending performance and the flexibility of these plate members, a doctor blade which does not have a risk of damaging the roll surface and can perform appropriate doctor ring can be realized.

Further, the blade edge of the doctor blade can be pressed against the roll surface with a sufficient linear pressure without increasing the pressing force applied to the doctor blade.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a doctor device including a doctor blade to which the present invention is applied.

FIG. 2 is a sectional view of the doctor blade of FIG. 1;

FIG. 3 is a sectional view showing another example of a doctor blade according to the present invention.

FIG. 4 is a sectional view of a doctor blade proposed by the present applicant.

[Explanation of symbols]

 Reference Signs List 1 doctor device 2 doctor blade 20 first plate 21 cutting edge 22 tip 23 tapered portion 24 main body 24a surface of main body 30 second plate 3 blade holder 4 doctor back 100 roll 101 roll surface

Claims (5)

[Claims] 1. A doctor device in which a doctor blade is pressed against the surface of a rotating roll to scrape off foreign substances adhering to the surface of the roll, wherein the doctor blade has a cutting edge at the tip which is pressed against the surface of the roll. A doctor blade for a doctor device, wherein the doctor blade has a laminated structure including a first plate member thus formed and a second plate member made of a different material laminated and fixed on the surface of the first plate member. 2. The doctor blade according to claim 1, wherein the second plate is formed of a material having higher rigidity than a material of the first plate. 3. The doctor blade according to claim 2, wherein the first plate member is formed of a synthetic resin material, and the second material is formed of a metal material. 4. The method according to claim 1, wherein the first plate member includes a main body having a constant thickness,
It has a cross-sectional shape including a tip portion having a constant thickness thinner than the main body portion and a tapered portion formed between the main body portion and the tip portion. The doctor blade of the doctor device, wherein the blade edge is formed, and the second plate member is laminated and fixed on a surface of the main body portion. 5. The apparatus according to claim 4, wherein a length from a tip of the cutting edge to the tapered portion at a tip of the first plate is set to a value within a range of 3 mm to 7 mm. The doctor blade of the doctor device.