JPH0570010A - Paper feed roller - Google Patents

Abstract

PURPOSE:To provide a paper feed roller prevented from the adhesion of paper fiber since, in the paper feed roller having projections formed on the surface of a metallic cylindrical body through etching, its surface is formed into rough fine irregular shape through the etching to facilitate the adhesion of the paper fiber for lowering the gripping force of the paper feed roller. CONSTITUTION:A paper feed roller 11 is formed of a metallic cylindrical body 12, and many projections 15 are formed on its outside surface by an etching process. A surface hardening treatment is applied to the roller 11 to prevent the abrasion of the projection 15 caused by using the roller, and at last, a thin film pattern hard coating treatment, for instance the coating of an electroless nickel plating layer 17, is applied to the roller to check the adhesion of a paper fiber caused by fine irregularity 16 on the whole surface of the roller. The fine irregularity 16 on the surface is thereby blocked for checking the adhesion of the paper fiber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a paper feed roller which is particularly effective for use in OA equipment and the like.

[0002]

2. Description of the Related Art In equipment such as an XY plotter, a fax machine and a copier, a paper feed roller is used to feed a paper at a predetermined speed. For example, in the above-mentioned XY plotter, a pen that moves in a direction perpendicular to the paper feed direction is used, and while the paper is moved forward and backward in the feed direction, the pen is run substantially in the XY direction on the paper surface. It is necessary to move the paper accurately for drawing. As such a paper feed roller, it is desired that the paper feed roller has high dimensional accuracy, does not elastically deform, reliably grips the paper, and has high abrasion resistance.

Japanese Patent Laid-Open No. 60-23248 discloses a spring in which a hollow roller body is supported by a rotary shaft so that the distance to the rotary shaft can be elastically displaced and the roller body itself can be deformed. A paper feed roller is shown which is formed of an elastic metal member and is formed by assembling fine projections of substantially the same height on the surface thereof at substantially uniform fine intervals. Then, as a preferred embodiment, it is disclosed that fine projections are formed on the surface of the stainless steel plate by etching.

Further, the applicant of the present invention accurately machined the inner peripheral surface and the outer peripheral surface of a metal cylindrical body, then applied a resin in a dot shape on the outer peripheral surface, and etched the cylindrical body to obtain a large number of fine particles. A method for manufacturing a high-friction roller having protrusions has already been proposed (JP-A-3-94080). Also, a method has already been proposed in which the resin is applied to the cylindrical body by screen printing (Japanese Patent Laid-Open No. 3-130186). Thus, by directly etching the outer peripheral surface of the metal cylindrical body to form the protrusions, a high friction roller having high dimensional accuracy and excellent durability can be obtained.

[0005]

However, when the projection is formed by etching the surface of the metal, the roller including the projection surface becomes rough and has fine irregularities. Moreover, the minute projections are formed innumerably on the roller surface, and therefore, every time the paper is fed, the surface of the paper is constantly rubbed by the minute projections to slide. Fine fibers of the paper are scraped off and bite into the fine irregularities formed by the etching, and even minute protrusions are covered and deposited depending on the place.

In such a state, the coefficient of friction of the paper feed roller is lowered, the grip force is lowered, and the paper feed roller and the paper slide on each other during feeding, and as a result, the feed speed is naturally increased. And the problem of inaccurate feed accuracy occurs.

Therefore, an object of the present invention is to eliminate the unevenness of the surface of a paper feed roller in which a large number of projections are formed by etching the outer surface of a cylindrical body made of a metal material and to make it a relatively smooth surface. Therefore, it is an object of the present invention to provide a paper feed roller in which the fibers of the paper do not bite on the surface of the roller and the grip force is maintained well.

[0008]

According to the present invention, after the outer surface of a cylindrical body is subjected to an etching treatment, a hard coating is further applied so that the fine irregularities formed during the etching are covered with the hard coating. It was made in view of the fact that the surface becomes smooth, whereby the fibers of the paper are prevented from adhering and the grip force is maintained.

That is, the present invention is characterized in that a large number of projections are formed by etching on the outer surface of a cylindrical body made of a metal material, and further a hard coating is provided on the outer surface of the cylindrical body.

In a preferred aspect of the present invention, at least the outer surface of the cylindrical body is hardened, and the hard coating is further provided thereon. In the above, examples of the hardening treatment include nitriding treatment and quenching treatment.

[0011] In a further preferred aspect of the present invention, the hard coating comprises an electroless nickel plating layer. In the electroless nickel plating, a nickel feed layer is deposited on the roller surface by immersing the paper feed roller in a plating bath as a final step, and it has an advantage that the processing man-hour is simple and the production is quick. Further, the surface of the paper feed roller can be covered with a thin layer having a uniform thickness, and the hardness thereof is high, so that it can sufficiently withstand abrasion due to long-term use.

However, the hard coating is not limited to the above-mentioned plated layer, and a layer coated with a hard metal or the like by ion plating, thermal spraying or the like can also be used.

[0013]

In the paper feed roller of the present invention, the outer surface of the roller having projections formed by etching is coated with a hard coating, so that fine irregularities on the surface are covered with the hard coating, and the outer surface is smoothed. It is possible to prevent the fibers from biting or adhering.

Moreover, since the projections for maintaining the contact resistance with the paper are formed as they are, the grip force does not change and the paper is displaced left and right during the movement. , It does not cause uneven feeding.

Further, by hardening the surface of the metal cylinder and further providing the hard coating, the durability of the paper feed roller can be further improved.

Further, if the electroless nickel plating layer is used as the hard coating, the hardness is extremely thin, but the hardness is particularly hard as compared with other plating layers. Can withstand wear due to long-term use.

Even if the electroless nickel plating coats the entire surface of the roll, it does not change or deform the shape of the projection itself, and therefore does not deteriorate the quality of the roll itself.

[0018]

EXAMPLES Examples of the present invention will be described below.

As shown in FIG. 1, the paper feed roll 11 according to the present invention is formed by first cutting a metal material such as carbon steel into a cylindrical body 12 and secondly etching it. Innumerable protrusions 15 and 15 are formed by, and thirdly, the outer surface is hardened, and fourthly, hard coating is applied 17 to complete the process.

More specifically, each step will be described in more detail. First, as the cylindrical body 12, carbon steel is used because it is easily etched and the hardness can be increased by quenching. Is preferably adopted. The cylindrical body 12 is formed by molding a metal such as carbon steel by a method such as casting, rolling, and punching a column. When carbon steel is used, it is preferable to perform quenching treatment.

Then, the outer surface of the cylindrical body 12 and the hole of the shaft core are processed so as to have a roughness of 10 s or less, and the cylindrical body 12 having accurate inner and outer circumference accuracy is obtained. A sleeve 14 for inserting a rotary shaft is attached to a shaft core 13 fitted to the inner circumference of the cylindrical body 12. The outer surface of the cylindrical body 12 serves as a friction surface with which the paper comes into contact.

Second, a large number of protrusions are formed on the outer surface of the cylindrical body 12 by etching. As one of the methods,
Acid-resistant resin is screen-printed in a dot shape on the outer surface of the cylindrical body 12. Screen printing is performed by, for example, Japanese Patent Laid-Open No. 3-13.
It can be carried out using a screen printing machine as shown in No. 0186.

That is, the rotary shaft is inserted and fixed in the hole of the cylindrical body 12, and the cylindrical body 12 is brought into contact with the lower surface of the silk screen. Many fine dot holes are formed on this silk screen. A squeegee is arranged on the upper surface of the silk screen, and a predetermined amount of acid-resistant resin is applied to the contact surface between the squeegee and the silk screen.

In this state, the cylindrical body 12 is rotated together with the rotating shaft, and at the same time, the silk screen is moved. Thus, the applied acid-resistant resin is pressed by squeegee and applied in a dot shape on the outer surface of the cylindrical body 12 through the dot holes.

Next, as an etching treatment, a known etching liquid such as hydrochloric acid, sulfuric acid or nitric acid is used, and the surface is corroded by immersing it in a treatment liquid diluted with water to some extent. The cylindrical body 1
The portion of the outer surface of the outer surface 2 to which the acid-resistant resin is applied is not corroded by the etching solution and remains, so that the protrusion 1
5 is formed.

Thirdly, the cylindrical body 12 on which the projections 15 and 15 are formed is preferably subjected to a nitriding treatment in order to increase the hardness of the surface thereof. In this case, place it in ammonia gas, heat it to about 500 degrees, and leave it for about 5 to 50
When left for a time, the surface is nitrided to increase the hardness and wear resistance of the entire surface is obtained. The cylindrical body 12
When carbon steel is used as the material of the above and is preliminarily quenched, this nitriding treatment may not be performed.

However, the paper feed roll 1 thus obtained
In No. 1, the fine rough surface 16 is generated on the entire surface of the paper feed roll 11 by the etching treatment for forming the projections 15 and the nitriding treatment for surface hardening.
This is necessary because it causes the fibers of the paper to be attracted.

For this reason, fourthly, a hard coating treatment is carried out as a final finish. Examples of this hard coating treatment include electroless nickel plating. This is to form a thin plating film by keeping the mixed solution of nickel and phosphorus at around 20 ° C. and immersing the paper feed roll 11 therein. In this case, since the thickness of the coating film is proportional to the immersion time, if the immersion time is adjusted according to the fine roughness of the roll surface, a plated surface with no surface roughness is formed.

FIG. 2 is a conceptual diagram showing a state in which this hard coating layer is formed. Here, 15 is a protrusion, 16 is a fine unevenness on the surface, and 17 is an electroless nickel plating layer. On the surface of the paper feed roller 11, many fine protrusions in such a state are formed. The hardness of the plating layer 17 is preferably about 1,000 to 1,500 in Vickers hardness.

Although the material of the cylindrical body 12 is carbon steel in the above description, it may be other metal material such as stainless steel. Further, as the formation of the hard coating, ion plating such as titanium carbide or titanium nitride may be performed.

Thus, a large number of fine projections 15, 15 are formed on the outer surface of the paper feed roller 11, and the paper is accurately fed by the pressure contact between the projections 15 and the paper. By applying a hard coating on the entire outer surface of the roller to prevent the fibers from sticking, it is possible to sufficiently prevent the fibers from sticking to the paper, effectively lowering the coefficient of friction and effectively preventing the paper surface from becoming dirty. it can.

[0032]

As described above, according to the paper feed roller of the present invention, a large number of protrusions are formed by etching the outer surface of a cylindrical body made of a metal material, and preferably the outer surface is cured. After treatment, it is characterized by further coating with a hard coating, so that even in long-term use, the accumulation of paper fibers due to pressure contact between the paper and the paper feed roll disappears, and the friction resistance also changes constantly. , Uniform operation can be obtained. Further, if the hard coating is an electroless nickel plating layer, the hardness is high, so that the wear resistance during use can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a paper feed roller according to the present invention.

FIG. 2 is a conceptual diagram showing a state where a hard film treatment is performed.

[Explanation of symbols]

 11 Paper Feed Roller 12 Cylindrical Body 13 Shaft Core 14 Rotating Shaft 15 Protrusion 16 Fine Asperity 17 Hard Coating Layer

Claims (3)

[Claims] 1. A paper feed roller, wherein a large number of projections are formed by etching on the outer surface of a cylindrical body made of a metal material, and a hard coating is provided on the outer surface of the cylindrical body. 2. The paper feed roller according to claim 1, wherein at least an outer surface of the cylindrical body is hardened, and the hard coating is further provided. 3. The paper feed roller according to claim 1, wherein the hard coating is an electroless nickel plating layer.