JPH09183533A - Paper feed roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carrying roller having friction coefficient equivalent to that of polished one without polishing a rubber roller by forming a pattern groove on the surface of a rubber roller inclining against the rotating direction, and forming the groove depth to be over a specific value. SOLUTION: A pattern groove 13 inclined at about 60 deg. against the rotating direction 12 is formed on the surface 11 of a rubber roller 10. This pattern groove 13 is formed by integratedly molding together with manufacture of the rubber roller 10 or by embossing and the like, so as to form lozenge-shaped contact surfaces by crossing the grooves to each other. The depth of the groove 13 must be over about 50μ, usually over 0.1mm, and favorably about 200μ is appropriate at considering durability from the abrasion resistance of the roller. This pattern grooves 13 are crossed at about 60 deg. inclination against the rotating direction, but the angle is properly changed according to the peripheral speed of the roller 10. Namely, the higher the peripheral speed is, the smaller the inclination is, and the slower the speed is, the larger the inclination is.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feed roller for carrying paper sheets in office equipment such as printers and copying machines.

[0002]

2. Description of the Related Art In office equipment such as printers, copiers, and fax printers, paper feed rollers for conveying paper sheets are widely used.

The elastomer (rubber and resin), which is the material of the paper feed rubber roller, has a reduced frictional force when the paper is conveyed. The main cause of this is that, as shown in FIG. 4, a pulp fiber fragment (hereinafter referred to as paper dust) 1 or the like, which is a material of paper, enters between the roller 2 and the paper sheet 3 and is due to the principle of roller.
It is known to reduce friction.

In the prior art, FIGS. 5 (a) and 5 (b) are used.
There is a method of polishing the roller 2 with a grindstone or the like to generate the polishing grain 4 so that the paper dust 1 collects on the valley side of the polishing grain 4 as shown in FIG.

Alternatively, FIG. 5 (c), FIG. 5 (d), and FIG.
As shown in (e), there is also a method of forming a concavo-convex portion having the shape of the tooth profile 5 or the V groove 6 on the surface of the roller 2 with a foam or the like. As a principle of the roller 2, as shown in FIG. 5 (e), the paper dust 1 enters the uneven portion 7. Therefore, providing the uneven portion 7 is a method of preventing the reduction of the frictional force due to the paper dust 1.

As for the unfoamed body and the foamed body, as shown in FIG. 6, the coefficient of friction of the unfoamed body m decreases as the number of passed sheets increases, but the friction coefficient of the foamed body n becomes equal to the number of passed sheets. It is stable regardless.

[0007]

However, (1) the tooth profile 5, the V groove 6 and the foam have a small contact area with the paper sheet 3 and a small frictional force. Further, the tooth profile 5 and the V groove 6 are
In the case of using two pieces, if the convex portions are not aligned and they are not rotated synchronously, the load of the frictional force is shifted to the sheet and the sheet is sent obliquely.

(2) The polishing process has a maximum step difference of 1
It is not more than 00 μm. By transporting the paper sheets, the surface of the roller 2 is abraded, and the polishing marks 4 as the uneven portion are easily lost. A low-hardness roller can process a step of 50 μm or more, but the contact area becomes small and the frictional force becomes small as in the case of (1). In the case of polishing, the scraped rubber adheres to the roller surface and cannot be completely removed even by washing. Even if it can be removed, the tip 8 of the abrasion mark 4 on the surface of the roller 2 is easily cut as shown in FIG. 5 (f), and when the paper sheet is conveyed, the cut rubber easily adheres to the paper sheet. .

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and to provide a paper feed roller having a friction coefficient equivalent to that of a rubber roller without polishing.

[0010]

In order to achieve the above object, the invention of claim 1 forms a pattern groove on the surface of a rubber roller by inclining it with respect to the rotation direction and makes the groove depth 0.1 mm or more. The formed paper feed roller.

According to a second aspect of the invention, there is provided the paper feed roller according to the first aspect, wherein the pattern groove is formed to be 1/3 or less of the roller contact area.

The invention of claim 3 is the paper feed roller according to claim 2, wherein the depth of the pattern groove is about 0.2 mm.

A fourth aspect of the present invention is the paper feed roller according to the third aspect, wherein the edge of the roller contact surface defined by the pattern groove is chamfered with R = 0.1 mm or more.

A fifth aspect of the present invention is the paper feed roller according to the fourth aspect, wherein the pattern groove is inclined about 60 degrees with respect to the rotation direction.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 (a) is a developed view of the essential parts of the paper feed roller of the present invention. In the figure, 10 is a rubber roller made of rubber, elastomer, resin or the like, and the surface 11 of the rubber roller 10 is A pattern groove 13 inclined by about 60 degrees with respect to the rotation direction 12 is formed. This pattern groove 13
Are formed by integral molding or embossing with the manufacturing of the rubber roller 10 so that the diamond-shaped contact surfaces 14 are formed by crossing each other.

The rubber roller 10 has, for example, a rubber hardness of 2
At 5 degrees, the roller width is 24 mm, the roller diameter is 24 mm, the paper feed speed is 175 mm / sec, and the outer diameter is worn by 0.2 mm when 100,000 sheets are passed. Further, the diameter of pulp fiber, which is a raw material of paper, is 50 μm or less, and the amount of paper powder is about 5 μm.

In forming the pattern groove 13, the groove 1
The depth h of 3 is 50 μm or more, preferably 0.1 mm or more, and preferably, the groove depth is about 200 μm in consideration of the durability life of the roller.

As shown in FIG. 1B, the pattern groove 13
Area (width) b of the roller contact surface (width) a is
It is formed so as to be 1/3 (1/3 <b / a).
That is, the relationship between the width of the groove and the contact area between the paper and the roller is
Under the same conditions, if the contact area between the paper and the roller is large, the frictional force is also large, and ideally b / a is zero. Groove area is required. However, if the groove area is increased, the variation (amplitude) in dynamic friction increases, so in consideration of these, the area of the pattern groove 13 is set so that 1/3 <b / a.

The pattern groove 13 is inclined about 60 degrees with respect to the rotation direction and crossed, but the angle is appropriately changed according to the peripheral speed of the roller 10. That is, if the peripheral speed is high, the tilt angle is small, and if the peripheral speed is slow, the tilt angle is large.

The corners of the diamond-shaped contact surface 14 are R1 and R2.
By chamfering (0.1 mm ≤ R1, R2), the flow of paper powder is changed, and it is easy to fly to the outside. In addition, the peripheral edge of the contact surface 14 defined by the pattern groove 13 is shown in FIG.
As shown in (c), it is advisable to chamfer R3 (0.05 mm≤R3).

By applying the chamfers R1, R2 and R3, the stress concentration due to the rubber deformation can be further eliminated and the mechanical loss can be reduced. That is, as shown in FIG. 2C, when the contact surface 14 is not chamfered, when a force is applied as shown by an arrow 16, the contact surface 14 is easily deformed as shown by a dotted line 17, but as shown in FIG. Chamfered R1, R
When 2 and R3 are applied, even if a force is applied as shown by arrow 16, the force escapes at the chamfered portion and it is only slightly deformed as shown by the dotted line 18, as shown in FIG. 2 (a) as a whole. It is preferable to chamfer because it can be deformed as shown by the dotted line 19 to release the force of the arrow 16, which can further reduce stress concentration and reduce mechanical loss.

FIG. 3 shows various modifications of the pattern groove 13 of the present invention. FIG. 3 (a) shows an example in which the pattern groove 13a is formed in a zigzag shape, and FIG. 3 (b).
Shows an example in which the pattern groove 13b is formed in a wave shape, and FIG. 3 (c) shows an example in which the pattern groove 13c is formed in a V shape.

When the pattern groove 13 and the contact surface 14 are formed, the roller shaft 20 having the irregularities 21 is
You may make it form by coating the rubber 22 used as the contact surface 14.

A specific example will be described below.

(A) Application conditions: (1) The peripheral speed of the roller contact portion is 50 mm / sec (2) Rubber hardness: 30 ° (JIS A type) (3) Pressing load: 100 g (4) Roller width 10 to 20 mm (5) Rubber thickness; 2 mm (b) Suitable conditions for application conditions: (1) Groove depth; around 150 μ (2) Groove width; 0.2 to 0.4 mm (3) Rotation direction Groove angle; 60 ° (4) Contact surface shape; Rhombus with a side of 2 mm (5) Chamfering of convex portion; R1,2,3 0.2 mm or more In the present invention, the pattern groove is rotated relative to the rotating direction. By setting the depth of the groove to be 0.1 mm or more, there is a frictional force, it can be conveyed better than paper sheets, and paper dust can be taken in the pattern groove and blown off, resulting in slippage. Wear resistance is reduced.
Further, by chamfering the peripheral edge of the contact surface, the self-cleaning effect can be enhanced, and the deformation force can be released even when the rubber is deformed, and the mechanical strength can be improved.

[0027]

In summary, according to the present invention, the following effects can be obtained.

(1) Even if the rubber roller is not polished, the friction coefficient corresponding to the polishing can be maintained.

(2) The surface flea of the uneven portion is not polished,
Generate a logical polishing pattern.

(3) When the uneven portion disappears, this can be used as a guide for replacement.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram illustrating rubber deformation with respect to an applied force in the present invention.

FIG. 3 is a diagram showing another embodiment of the present invention.

FIG. 4 is a diagram showing a usage state of a conventional paper feed roller.

FIG. 5 is a diagram showing a conventional paper feed roller.

FIG. 6 is a diagram showing a relationship between the number of passed sheets and a friction coefficient.

[Explanation of symbols]

 10 rubber roller 13 pattern groove 14 contact surface

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[Procedure amendment]

[Submission date] January 24, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction contents]

As shown in FIG. 1B, the pattern groove 13
Area (width) b of the roller contact surface (width) a is
It is formed so as to be 1/3 or less (1/3 ≧ b / a). That is, if the relationship between the width of the groove and the contact area between the paper and the roller is the same, if the contact area between the paper and the roller is large, the frictional force is also large, and ideally b / a is zero. Is ideal, but since paper dust is caught, a certain groove area is required. However, when the groove area is increased, the variation (amplitude) in dynamic friction increases, so in consideration of these, the area of the pattern groove 13 is set so that 1/3 ≧ b / a.

Claims (5)

[Claims] 1. A pattern groove is formed on a surface of a rubber roller by inclining with respect to a rotation direction and a groove depth is 0.1 m.
A paper feed roller characterized by being formed to have a length of m or more. 2. The pattern groove is 1 with respect to the roller contact area.
The paper feed roller according to claim 1, wherein the paper feed roller is formed to have a width of / 3 or less. 3. The paper feed roller according to claim 2, wherein the depth of the pattern groove is about 0.2 mm. 4. The chamfer of R = 0.1 mm or more is applied to the edge of the roller contact surface defined by the pattern groove.
Paper feed roller described. 5. The paper feed roller according to claim 4, wherein the pattern groove is inclined about 60 degrees with respect to the rotation direction.