JP3386341B2 - Rubber coated roller - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber-coated roller suitable for a paper feed roller used in office automation equipment such as copiers, printers and facsimiles.

[0002]

2. Description of the Related Art As a paper feed roller for OA equipment, a rubber-coated roller in which a rubber member having a uniform thickness is attached to the outer periphery of a core formed of ABS resin or polyacetal resin in a round shaft shape is often used. . This type of rubber-covered roller is generally manufactured by separately manufacturing a core material and a rubber sleeve that is a cylindrical rubber member, and then inserting the rubber sleeve into the core material. In this case, set the inner diameter of the rubber sleeve in a single state before it is inserted into the core material to be slightly smaller than the outer diameter of the core material, press the rubber sleeve into the core material, and do not use adhesive etc. The rubber sleeve is fixed to the core material only by the tightening force due to the elastic contraction.

[0003]

The rubber coated roller used as the paper feed roller of the OA equipment as described above is an OA.
Due to the demand for miniaturization of equipment, the diameter is becoming smaller and smaller. Therefore, it is demanded that the cylindrical rubber sleeve fitted around the outer periphery of the core material be made thinner and thinner, but this thickness reduction is difficult with the problem of quality deterioration. is the current situation. That is, when a thin cylindrical rubber sleeve having a thickness of about several mm is inserted into the core material and the paper is fed on the surface of the rubber sleeve, the strain applied to the surface of the rubber sleeve at the time of feeding the paper directly causes the thin rubber sleeve. A large amount of twisting force is transmitted to the inside of the sleeve and the contact part between the core material and the rubber sleeve is applied, and this twisting force causes cracks in the thin rubber sleeve. More likely.

Therefore, the material of the rubber sleeve has a high friction coefficient, wear resistance, and environment resistance (especially environment resistance against O ₃ and heat).
Technical studies have been conducted to suppress the occurrence of cracks (rubber tears) in the rubber sleeve, such as by making it an excellent EPDM rubber, but the rate of occurrence of rubber tear is still high, and the thickness of the rubber sleeve is reduced. At present, it is difficult to reduce the diameter of rubber-coated rollers.

An object of the present invention is to provide a rubber-coated roller in which the thickness of the rubber sleeve and the diameter of the paper feed roller are reduced without deteriorating the performance and quality of the cylindrical rubber sleeve fitted into the core material. Especially.

[0006]

SUMMARY OF THE INVENTION The present invention is a rubber-coated roller in which a cylindrical rubber sleeve is elastically fitted around the outer circumference of a round shaft-shaped core material, and the dimensional relationship between the core material and the rubber sleeve is as follows. As described above, the above object is achieved by modifying the tightening force of the rubber sleeve on the core material.

That is, if the outer diameter of the core material is a and the inner diameter of the cylindrical rubber sleeve before being fitted into the outer circumference of the core material is b, then a> b
And when the tightening margin x (%) to the core material due to the inner diameter of the rubber sleeve when the rubber sleeve is fitted on the outer periphery of the core material is [1- (b / a)] × 100, % ≦ x ≦
The thickness of the rubber sleeve is 14%, and the thickness of the rubber sleeve when the rubber sleeve is fitted around the core material is set to 3 mm to 2 mm .

The above-described relationship between the dimensions of the core material and the rubber sleeve is established by making the inner diameter of the cylindrical rubber sleeve before being fitted into the core material smaller than the current inner diameter. By doing so, the tightening force of the rubber sleeve on the core material is increased, the occurrence rate of rubber tearing is reduced, and the thickness of the rubber sleeve is easily thinned.

In the rubber-coated roller of the present invention, it is desirable that the rubber sleeve is made of EPDM rubber in terms of high friction coefficient, abrasion resistance, environment resistance, cost and the like.

When the rubber-coated roller of the present invention is used as a paper feed roller for OA equipment, a predetermined test rubber piece is made to be 100%, that is, twice as long as the rubber sleeve according to the measuring method specified in JIS. 4 to 10 when extended
It is desirable to mold the rubber having a modulus (elastic modulus) of kg / cm ² in order to improve the function and life of the paper feed roller.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a rubber-coated roller of the present invention applied to, for example, a paper feeding roller of an office automation equipment will be described with reference to FIGS. 1 and 2. The rubber-coated roller 1 shown in FIG. , A cylindrical rubber sleeve 3 which is a rubber-like elastic body is press-fitted to the outer circumference of a round shaft-shaped core material 2 which is molded in the same manner as in the past by using ABS resin, polyacetal resin or the like. The basic structure of the rubber-covered roller 1 may be the same as the conventional one. In the present invention, as shown in FIGS. 2 (I) and (II), the outer diameter a of the portion of the core material 2 into which the rubber sleeve 3 is fitted, An inner diameter b of the cylindrical rubber sleeve 3 before being fitted into the core material 2,
The thickness t of the rubber sleeve 3 fitted into the core material 2 is set as follows.

The cylindrical rubber sleeve 3 is a rubber sleeve molded by a transfer molding method or the like, and the inner diameter b in the molding step is set to be slightly smaller than the outer diameter a of the core material 2 so that a> b. With this dimension setting, the rubber sleeve 3 is pressed into the core material 2, and the rubber sleeve 3 is fixed to the core material 2 by the tightening force of the rubber sleeve 3 to the core material 2. Further, when the rubber sleeve 3 is fitted on the outer periphery of the core material 2, the tightening margin x (%) of the inner periphery of the rubber sleeve 3 to the core material 2 is x =
When [1- (b / a)] × 100, the present invention is 8
% ≦ x ≦ 14%, and the thickness t of the rubber sleeve 3 when the rubber sleeve 3 is fitted on the outer periphery of the core material 2 is 3
It is characterized by being regulated to mm 2 to 2 mm.

That is, the inventor of the present invention sets the inner diameter b of the rubber sleeve 3 to be smaller than the current inner diameter, and sets the rubber sleeve 3
Various sample products were tested to see how the function and quality of the rubber sleeve 3 as a paper feed roller are improved by increasing the tightening margin x to the core material 2. The experimental results are shown in Table 1 below and will be described.

However, the experimental data in Table 1 shows that the material of the rubber sleeve 3 is EPDM rubber and the modulus at 100% elongation is 6.5 kg / cm ² . In addition, the experimental data in Table 1 is the result of the continuous paper feed endurance test in which the sample products A to K were used as the paper feed rollers of the copying machine and the maximum number of A4 vertical paper feeds was 300,000. Is.

[0015]

[Table 1]

The sample product A has a rubber sleeve fitted to the core material with a thickness t of 5 mm and a tightening margin x of 6%.
The rubber sleeve does not crack in the relatively thick rubber sleeve even after the passage of 0,000 sheets, and the function as the paper feed roller of the OA equipment is excellent. However, the thickness t of the rubber sleeve is 5 mm
Since it is thick, it is difficult to reduce the diameter of the paper feed roller with the downsizing of OA equipment.

The sample product B has a rubber sleeve fitted in the core material with a thickness t of 4 mm and a tightening margin x of 6%.
Although rubber tearing does not occur in a relatively thick rubber sleeve even when paper is passed through up to 00 sheets, the thickness t of the rubber sleeve is relatively thick as 4 mm in this case as well. It is difficult to reduce the diameter.

In the sample product C, the thickness t of the rubber sleeve fitted into the core material is 3 mm and the interference x is 6%, and the thickness t of the rubber sleeve is relatively thin as 3 mm.
Although it is easy to reduce the diameter of the paper feed roller in accordance with the downsizing of equipment, a rubber tear occurs in the rubber sleeve at the 150,000th sheet passing, which makes it unsuitable as a paper feed roller for OA equipment.

In the sample product D, the thickness t of the rubber sleeve fitted to the core material is 2 mm and the tightening margin x is 6%. It is even easier to reduce the diameter of the paper feed roller,
At the 50,000th sheet of paper passing, a rubber tear occurred in the rubber sleeve,
It is not qualified as a paper feed roller for OA equipment.

In the sample product E, the thickness t of the rubber sleeve fitted in the core material is 2 mm and the tightening margin x is 7%, and in this case as well, the diameter of the paper feed roller is reduced as the OA equipment is downsized. However, it is not suitable as a paper feed roller for OA equipment because a rubber tear occurs in the rubber sleeve at the 130,000th sheet passing.

The sample product F is a product of the present invention. The thickness t of the rubber sleeve fitted in the core material is 2 mm, and the tightening margin x is 8%. It is easy to reduce the diameter of the paper feed roller due to the above, and even if the thickness t of the rubber sleeve is thinned to 2 mm and 300,000 sheets are passed, the rubber tear does not occur in the rubber sleeve. Good function is maintained.

Each of the sample products G, H, and I is also a product of the present invention, and the thickness t of the rubber sleeve fitted in the core material is the same 2 mm, and the tightening margin x is 10%, 12%, 14 % Gradually increasing. Each of the sample products G, H, and I also facilitates the reduction of the diameter of the paper feed roller due to the miniaturization of the OA equipment, and even if the rubber sleeve is thinned to pass 300,000 sheets, the rubber sleeve is torn. Without doing so, the function as the paper feed roller of the OA device is favorably maintained.

In the remaining sample product J, the thickness t of the rubber sleeve fitted in the core material was increased to 2 mm and the tightening margin x was increased to 15%. In this case, the tightening margin x was too large. However, the rubber sleeve cannot be pressed into the core material uniformly and cannot be used as a paper feed roller. In addition, the sample product K is a product in which the tightening margin x is further increased to 17%,
In this case, the rubber sleeve cannot be pressed into the core material and cannot be used as a paper feed roller.

From the above experimental results of each of the sample products A to K, when the tightening margin x is 8% or more and 14% or less, rubber tear does not occur even when 300,000 sheets are passed, and it is suitable as a feeding roller. I understand. In addition, the restriction of the numerical value of the tightening margin x realized the thinning of the rubber sleeve by 3 mm to 2 mm .

Further, in the rubber covered roller 1 shown in FIGS. 1 and 2, it is desirable that the rubber sleeve 3 is made of EPDM rubber in terms of high friction coefficient, abrasion resistance, environment resistance, cost and the like.

Furthermore, when the rubber-coated roller 1 is used as a paper feed roller for OA equipment, the rubber sleeve 3 is set to 100 mm.
It has been found desirable to mold with a rubber having a modulus at 4% elongation of 4 to 10 kg / cm ² , and more preferably to have a modulus at 100% elongation of 5 to 8 kg / cm ² . That is, the experimental data in Table 1 shows that the modulus at 100% elongation is 6.5 kg / c.
It was obtained by using a rubber sleeve of m ² , and even if this modulus was increased or decreased in the range of 5 to 8 kg / cm ² , the experimental data in Table 1 was almost the same and there was no problem, and the modulus was 4 to 10 kg / cm ^2. It does not make a big difference if it is increased / decreased in a wider range of cm ² , but if it is increased / decreased in a range of more than ⁴ to 10 kg / cm ² , the trouble occurrence rate of loosening and crack damage of the rubber sleeve becomes high.

[0027]

According to the present invention, the tightening force of the cylindrical rubber sleeve press-fitted into the core material to the core material is increased, the occurrence rate of rubber tear is reduced, and the thickness of the rubber sleeve is reduced. As a result, it is possible to easily provide a rubber-coated roller having a high commercial added value that facilitates the reduction of the diameter of a paper feeding roller or the like of OA equipment. Further, by using EPDM rubber for the rubber sleeve, it is possible to provide a low-cost rubber-coated roller having a high friction coefficient, high abrasion resistance, and excellent environment resistance.

[Brief description of drawings]

FIG. 1 is a front view of a rubber-coated roller showing an embodiment of the present invention.

FIG. 2 (I) is an enlarged sectional view taken along line TT of FIG.
(I) is a sectional view of the rubber sleeve when the rubber sleeve is removed from the core material of (I).

[Explanation of symbols]

1 Rubber coated roller 2 core material 3 rubber sleeves a Core material outer diameter b Rubber sleeve inner diameter t Rubber sleeve wall thickness

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B65H 3/06

Claims (3)

(57) [Claims] 1. A rubber-coated roller in which a cylindrical rubber sleeve is elastically fitted on the outer circumference of a round shaft-shaped core material, wherein the outer diameter of the core material is a and before the outer circumference of the core material is fitted. When the inner diameter of the rubber sleeve is b, a> b, and when the rubber sleeve is fitted around the outer circumference of the core material, the tightening margin x (%) to the core material by the inner diameter of the rubber sleeve is x = [1- ( b
/ A)] × 100, there is a relationship of 8% ≦ x ≦ 14%, and the thickness of the rubber sleeve when the rubber sleeve is inserted into the outer periphery of the core material is 3 mm to 2 mm . Characteristic rubber coated roller. 2. The rubber-coated roller according to claim 1, wherein the rubber sleeve is EPDM rubber. 3. The rubber-coated roller according to claim 1, wherein the rubber sleeve is formed of a rubber having a modulus at 100% elongation of 4 to 10 kg / cm 2.