JP2000226144A - Paper feeding roller and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively manufacture a paper feeding roller with a large diameter and high shape and dimension stabilities by connecting and integrating a rotary shaft and a plurality of cylindrical roller parts constituted by pressurizing and molding a mixture made of hydraulic composition and curing and hardening the mixture in an axial direction and inserting the rotary shaft into these roller parts. SOLUTION: By pressurizing and molding a mixture made of hydraulic composition, forming cylindrical molded bodies 1 to 3 by curing and hardening the mixture, inserting a rotary shaft 4 into an object that these molded bodies 1 to 3 are connected on co-axial line and integrally connecting the cylindrical molded bodies 1 to 3 one another by using proper adhesive, a paper feeding roller is formed. At this time, the cylindrical molded body 1 is formed by providing a cylindrical recessed part and a cylindrical projecting part on a right side inner peripheral surface and at a left side tip part, respectively. The cylindrical molded body 2 and the cylindrical molded body 3 are formed by providing a cylindrical projecting part at a left side tip part and a cylindrical recessed part on a right side inner peripheral surface, respectively. By tightly fitting corresponding recessed parts and projecting parts, the paper feeding roller excellent in concentric circle property is obtained.

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 use in a printer, a facsimile machine, a copier or the like which uses a hydraulic composition for a roller portion and which needs to accurately transfer paper, and a method of manufacturing the same. About.

[0002]

2. Description of the Related Art Conventionally, metal rollers, rubber rollers and the like have been used as such paper feed rollers.

[0003]

The metal roller has been formed by welding, by welding, end plates having shaft portions attached to both ends of a hollow metal cylindrical body constituting the roller portion. In this case, the rotating shaft of the metal roller is formed by the shaft portions at both ends, but there is a problem that it is extremely difficult to ensure a concentric state between the metal cylindrical body and the rotating shaft.
Further, a paper feed roller in which the roller portion is made of hard rubber is used to reduce the weight, but there is a disadvantage that the thermal expansion of the roller portion is large and an error easily occurs in the paper feed operation.

[0004] In order to solve the above problems, there has been proposed a cement-made composite roller manufactured by pouring cement around the rotation axis after positioning the rotation axis at the center of the mold. However, since a large amount of water is used for pouring the cement, a volume change occurs at the time of drainage, and the shape and dimension stability is insufficient, which is not suitable for high precision.

Accordingly, the present applicant has filed a Japanese Patent Application No. Hei 10-177.
100 (filed on June 24, 1998) proposed a method for manufacturing a paper feed roller in which a cylindrical roller portion is formed by pressing a hydraulic composition into a cylindrical shape around a rotation axis. However, in this method, it is necessary to prepare a molding die for each type, and in order to cope with a large sheet of A3 or larger, the molding die and the pressing device of the paper feed roller become huge. This leads to an increase in cost, and as the size of the mold increases, the pressure during pressure molding becomes non-uniform, leading to a reduction in moldability, and to achieve the desired accuracy of the paper feed roller. There is a drawback that the time and labor for finishing are increased.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and uses a hydraulic composition to respond to various demands for a conventional paper feed roller. An object of the present invention is to provide a paper feed roller having excellent stability and high shape and dimension stability, and a method for manufacturing the same.

[Means for Solving the Problems]

A paper feed roller according to the present invention is a cylinder formed by press-molding a mixture comprising a hydraulic composition, curing and curing the mixture, and integrated with the outer peripheral surface of the rotation shaft. A paper feed roller comprising a cylindrical roller portion, wherein the cylindrical roller portion is formed by connecting a plurality of cylindrical molded bodies in a rotation axis direction. Preferred embodiments of the present invention include the following (1) to (3). Any combination of (1) and (3) is also considered a preferred embodiment. (1) The connection ends of the cylindrical molded bodies connected to each other have a shape that fits each other, and at these ends, the cylindrical molded bodies are connected to each other by fitting. Here, the shapes that are fitted to each other refer to a shape in which the convex portion is in a relationship with the concave portion so that it can be firmly fitted into the concave portion, or the shape can be loosely fitted so as to slide. (2) The hydraulic composition is 50 to 90% by weight of a hydraulic powder, and 10 to 50% by weight of a non-hydraulic powder having an average particle diameter smaller than the average particle diameter of the hydraulic powder by one digit or more. And 2 to 18 parts by weight per 100 parts by weight of the mixed powder
And a processability improver blended in parts by weight. (3) The processability improving agent is at least one selected from a vinyl acetate resin or a copolymer resin with vinyl acetate, an acrylic resin or a copolymer resin with acrylic, a styrene resin or a copolymer resin with styrene, and an epoxy resin. It is a powder or emulsion composed of various kinds of resins.

In the method for producing a paper feed roller of the present invention, a plurality of cylindrical molded bodies having a hole at the center are formed from the hydraulic composition through the steps of molding, demolding, curing and curing. Then, a rotating shaft is inserted into the holes of the plurality of cylindrical molded bodies, and adjacent cylindrical molded bodies are connected to each other to form a cylindrical roller portion integrally on the outer peripheral surface of the rotating shaft. I do.

In another method of manufacturing a paper feed roller according to the present invention, a plurality of cylindrical shaped bodies having a hole at the center are obtained by molding and demolding from a hydraulic composition, respectively. After inserting the rotating shaft into the hole of the shape-forming body and connecting the adjacent cylindrical shape-forming bodies together, curing and curing the cylindrical shape-forming body to form a cylindrical molded body, A cylindrical roller portion is integrally formed on the outer peripheral surface.

[0010]

According to the paper feed roller and the method of manufacturing the same of the present invention, the cylindrical molded body of the hydraulic composition and the rotary shaft are integrated, so that the rotary shaft and the roller portion are excellent in concentricity. . In addition, since the roller portion is formed by pressing the hydraulic composition into a single piece, the shape is excellent in shape and dimension stability, and the paper feeding accuracy is excellent.

Further, since the length of the cylindrical molded body itself can be reduced as compared with a desired roller portion, the molding die can be downsized. In addition, by setting the length of one cylindrical molded body from the relationship between the size of the paper and the number of cylindrical molded bodies to be connected, it is easy to prepare a plurality of single-shaped cylindrical molded bodies in advance. It is possible to manufacture a plurality of types of paper feed rollers corresponding to the paper size by using a predetermined number of the single-shaped cylindrical molded bodies. Furthermore, as compared with the case of integrally molding with the rotating shaft, the molding of the cylindrical molded body and the formation of the roller portion can be performed with high accuracy, the finishing work can be reduced, and the production cost can be reduced. .

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail. 1. Paper feed roller (1-1) Rotary axis As the rotary axis used in the present invention, the same one as the rotary axis of the conventional paper feed roller is used. Examples of the shape include a shaft provided with a bearing mounting portion or a driving force transmission mechanism mounting portion or the like provided by cutting and finishing processing on a shaft supporting a cylindrical body serving as a paper feeding portion. Examples of the material include ordinary SUM free-cutting steel. Further, the surface may be subjected to electroless Ni-P plating or the like.

(1-2) Cylindrical Roller Portion In the paper feed roller of the present invention, the connecting end portions of the cylindrical molded bodies connected to each other have a shape that fits with each other, and the cylindrical end portions are formed at these ends. It is preferable that the shaped bodies are connected by fitting. By doing so, the adjacent cylindrical molded bodies are connected more firmly, and as a result, the integrity of the roller portion formed by the cylindrical molded bodies is more firmly maintained.

In the fitting, cylindrical projections and cylindrical recesses are provided at connection end portions of the cylindrical molded bodies connected to each other, and the cylindrical projections and the cylindrical recesses are nestedly fitted. It is preferable to have a structure that can be used. Further, by providing a spline-shaped fitting groove and a convex portion on the outer peripheral surface and the inner peripheral surface of the cylindrical convex portion and the cylindrical concave portion, respectively, the cylindrical molded bodies connected to each other can be slid in the circumferential direction. Can be prevented. In addition, the outer peripheral surface of the corresponding cylindrical convex portion and the inner peripheral surface of the cylindrical concave portion are each formed into a polygonal fitting structure, so that the cylindrical molded bodies connected to each other can slide in the circumferential direction. Can be prevented. Further, a concave portion may be provided on the inner peripheral surface of the cylindrical molded bodies connected to each other, and the cylindrical molded bodies may be connected to each other by a connecting member fitted over the concave portion.

The thickness of the cylindrical roller portion is determined by the outer diameter of the rotating shaft used and the paper feed roller having a desired outer diameter. The tolerance of the diameter of the cylindrical portion is set to a desired value in design, but is usually ± 0.003 mm of the desired outer diameter.
Is set to the processing accuracy of Further, a thermosetting resin mixed with abrasive grains may be applied and cured on the surface of the cylindrical roller portion in order to further reduce slip between the paper and the paper. Further, the surface of the cylindrical roller portion itself may be roughly finished using sand blasting or the like.

2. Mixture consisting of hydraulic composition The mixture consisting of the hydraulic forming composition used in the present invention is a hydraulic molding composition comprising a hydraulic powder, a non-hydraulic powder and a processability improver, and if necessary. It is a mixture of other additives to be added and water to be contained as required. The details are described below.

(2-1) Hydraulic Powder The hydraulic powder used in the present invention refers to a powder that is hardened by water, such as a calcium silicate compound powder, a calcium aluminate compound powder, and a calcium fluoroaluminate compound. Powder, calcium sulfoaluminate compound, calcium alumino ferrite compound powder, calcium phosphate compound powder, hemihydrate or anhydrous gypsum powder, self-hardening quicklime powder, and a mixture powder of two or more of these powders Can be illustrated. A typical example thereof is a powder such as Portland cement.

Regarding the particle size distribution of the hydraulic powder, it is preferable that the Blaine specific surface area is 2500 cm ² / g or more in order to secure hydraulic performance with respect to the strength of the molded product. Also,
The mixing amount of the hydraulic powder is 50 to 90% by weight based on the total amount of the hydraulic powder and the non-hydraulic powder of 100% by weight.
It is preferably 75% by weight. 50% by weight
If it is less than 90% by weight, the strength and the filling factor are low, and if it exceeds 90% by weight, the filling ratio for obtaining a molded body is low, and in any case, it can withstand the processing stress during mechanical processing. It is not preferable because it has effects such as not being able to be performed.

(2-2) Non-Hydraulic Powder The non-hydraulic powder refers to a powder which does not harden even when it comes into contact with water when used alone.
Alternatively, the powder includes a powder in which the component is eluted in a high-pressure steam atmosphere and reacts with other already-eluted components to form a product.
Representative examples of the non-hydraulic powder include, for example, calcium hydroxide powder, gypsum powder, calcium carbonate powder, slag powder, fly ash powder, silica stone powder, clay powder, silica fume powder and the like. The average particle size of these non-hydraulic powders is smaller than the average particle size of the hydraulic powder by at least one digit, preferably by at least two digits. The lower limit of the fineness need not be particularly set unless the effect of the present invention is impaired.

The compounding amount of the non-hydraulic powder is 10 to 50% by weight in terms of the composition ratio of the mixed powder composed of the hydraulic powder and the non-hydraulic powder, but is preferably 25 to 35% by weight. preferable. When the amount is less than 10% by weight, the filling rate is low, and when it exceeds 50% by weight, the strength and the filling rate are low. In any case, various physical properties after molding and curing, for example, It is not preferable because chipping occurs during machining and dimensional stability is adversely affected. In consideration of machinability and the like, it is preferable to adjust the blending amount of the non-hydraulic powder so that the filling rate does not become too low. By adding the non-hydraulic powder, it is possible to increase the filling rate of the molded article during molding and to reduce the porosity of the obtained molded article. Thereby, the dimensional stability of the molded body can be improved.

(2-3) Workability improver A workability improver is an improvement in the formability, mold release, cutting / grindability, and grinding accuracy of a molded product obtained from a hydraulic composition, particularly cutting / grinding. Refers to a material that has properties that contribute to the improvement of grinding properties and grinding accuracy. That is, the mixture comprising the hydraulic composition obtained by adding the processability improver improves the formability since the processability improver plays a role as a molding aid during pressure molding. Further, the molded body obtained by improving the fragility of the cement-based hardened body by the processability improver is released without any damage at the time of demolding, which leads to improvement in workability. In general, a molded product obtained from a hydraulic composition, which is a brittle material, exhibits a cutting state of a “crack type” mechanism during cutting, but in such a case, the material is cracked or chipped (microscopically). Problems).

Since the hydraulic composition of the present invention contains a processability improver, the resulting molded article is provided with toughness for promoting the machinability as a solid material, and the above-mentioned material is free from cracks, chips and the like. It is possible to prevent problems. In other words, the processability improver makes it possible to improve the processability of a molded body obtained from a hydraulic composition, which was conventionally difficult to machine such as cutting and grinding, to the same level as a metal material. In addition, cutting with a lathe or the like, and grinding with a cylindrical grinder or the like can be performed in the same manner as a metal material. By performing these processes, it becomes possible to perform a precise process on the order of μm for a desired dimension.

The compounding amount of the processability improver is 2 to 18 parts by weight on a dry basis with respect to 100 parts by weight of the mixed powder of the hydraulic powder and the non-hydraulic powder, but is 5 to 15 parts by weight. Is preferred. If the compounding amount is less than 2 parts by weight, the machinability deteriorates, which is not preferable. If the amount exceeds 18 parts by weight, the moldability is good, but the grinding accuracy is reduced and the dimensional stability after grinding is reduced. The particle size is generally 1 μm or less in terms of a single dispersed particle.

As the processability improver, at least one selected from a vinyl acetate resin or a copolymer resin with vinyl acetate, an acrylic resin or a copolymer resin with acrylic, a styrene resin or a copolymer resin with styrene, and an epoxy resin. Powders or emulsions of more than one type of resin can be used. Examples of the copolymer resin with vinyl acetate include vinyl acetate acrylic copolymer resin, vinyl acetate veova copolymer resin, vinyl acetate veoba terpolymer resin, vinyl acetate malate copolymer resin, vinyl acetate ethylene copolymer resin, and vinyl acetate ethylene vinyl chloride. Copolymer resins and the like can be exemplified.
Examples of the copolymer resin with acryl include an acryl styrene copolymer resin and an acryl silicone copolymer resin. Examples of the copolymer resin with styrene include a styrene butadiene copolymer resin.

(2-4) Other Additives In addition to the above essential components (2-1) to (2-3), the mixture comprising the hydraulic composition of the present invention may further comprise an aggregate such as silica sand as an extender. Powder mixture of hydraulic powder and non-hydraulic powder 10
10 to 50 parts by weight, preferably 20 to 3 parts by weight per 0 parts by weight
0 parts by weight can be added. In order to further improve the moldability, a known ceramic molding aid can be added in a proportion of 1 to 10 parts by weight, preferably 3 to 6 parts by weight, per 100 parts by weight of the mixed powder. Further, in order to suppress a dimensional change due to shrinkage or the like during curing of the material, a water repellent for reducing water absorption such as silicone oil is added in an amount of 0.5 to 5 parts by weight based on 100 parts by weight of the mixed powder.
Preferably, it can be added at a ratio of 1 to 2 parts by weight.

3. Manufacturing Method of Paper Feed Roller (1) Molding of Cylindrical Molded Article A cylindrical molded article having a predetermined length and an outer diameter and having a central hole through which a rotating shaft passes is molded from a predetermined hydraulic composition. . The length of one cylindrical molded body is set from the relationship between the dimensions of the paper and the number of cylindrical molded bodies connected to manufacture the paper feed roller. In this case, if necessary, the cylindrical molded bodies to be connected to each other are molded so that the connecting ends thereof are fitted to each other, and at these ends, the cylindrical molded bodies are connected to each other by fitting. It is possible.

In order to prepare a molding mixture using the hydraulic composition, the mixture of the hydraulic powder and the non-hydraulic powder is added to the hydraulic composition and other additives added as necessary.
30 parts by weight or less, preferably 25 parts by weight, of water
It can be obtained by mixing the components contained in parts by weight or less. In order to reduce drying shrinkage, it is preferable to reduce water as much as possible. Depending on the conditions, it may not be necessary to add water.

The method of mixing is not particularly limited, but preferably a mixing method or a mixer capable of applying a strong shearing force to the mixture. Since the non-hydraulic powder particle diameter has an average particle diameter that is at least one order of magnitude smaller than the hydraulic powder particle diameter, in order to obtain a uniform mixture, the time required for mixing is required unless a mixer having a shearing force is used. It will be very long.

Further, in order to improve the handling of the mixture during molding, the mixture may be granulated to a size suitable for the shape to be molded. As the granulation method, a known method such as a rolling granulation method, a compression granulation method, and a stirring granulation method may be used.
The molding mixture thus obtained is filled in a mold,
Pressing is performed by a method using a hydrostatic press, a multi-axial press, or a single-axial press. As the conditions for pressurization, it is preferable that the press pressure is higher so as to be as close as possible to the calculated theoretical density, but the lower limit condition is large due to the difference in the easy moldability of the mixture, the content of water or the required dimensional accuracy. different.

(2) Rotating shaft When a predetermined number of cylindrical molded bodies are assembled to the rotating shaft, a predetermined material is provided at both ends so that the bearing mounting portion or the driving force transmission mechanism mounting portion is exposed to the outside. To form a rotation axis. The outer diameter of the rotating shaft at the portion where the cylindrical molded body is attached is smaller than the inner diameter of the cylindrical molded body by about 10 to 50 μm, but is preferably 10 to 30 μm. If it is less than 10 μm, it becomes difficult to assemble the cylindrical molded body on the rotating shaft, and if it is larger than 50 μm, the roundness (deviation from concentricity) of the rotating shaft and the cylindrical molded body increases, and the roller accuracy decreases. . When the thickness is 30 μm or less, the cylindrical molded body can be attached to the rotating shaft due to shrinkage due to curing without using an adhesive.

(3) Assembly of Cylindrical Formed Body and Rotating Shaft (2-1) First Method After forming a plurality of cylindrical formed forms each having a hole in the center from the hydraulic composition, the cylindrical form is formed. Through the steps of demolding, curing and curing the formed body, a plurality of cylindrical molded bodies having a hole in the center are formed, and a rotating shaft is inserted into a predetermined position in the holes of the plurality of cylindrical molded bodies. Then, the adjacent cylindrical molded bodies are connected to each other, and a cylindrical roller portion is integrally assembled on the outer peripheral surface of the rotating shaft. After pressure molding, curing and curing of the cylindrical molded body removed from the mold can be performed by one or a combination of room temperature curing, normal pressure steam curing, autoclave curing, etc. Considering stability, dimensional stability and the like, autoclave curing is preferred.
After the curing in the autoclave for about 5 to 10 hours, the curing reaction of the cylindrical molded body is completely terminated, and the subsequent dimensional change becomes extremely small. When the autoclave curing is performed, the size of the cylindrical molded body shrinks in a range of 0.08 to 0.15% (depending on the blending conditions), so that the inner diameter portion of the cylindrical molded body is formed in consideration of the amount of shrinkage. At least 10μ is required to attach the cylindrical molded body to the rotating shaft after curing and curing.
m or more clearance is required, but after autoclaving, since there is no shrinkage of the cylindrical molded body,
It is also possible to use an adhesive for attachment to the rotating shaft, or to provide a clearance that can be attached by cooling the rotating shaft or heating the cylindrical molded body. As the adhesive to be used, an epoxy adhesive, a urethane adhesive, an emulsion adhesive, a synthetic rubber adhesive, an acrylate adhesive, or the like is used.

(2-2) Second Method Another method of manufacturing the paper feed roller of the present invention is to form a plurality of cylindrical forming bodies each having a hole in the center from a hydraulic composition, and then forming the cylindrical body. The shape-generating features are demolded to obtain a plurality of cylindrical shape-forming features having a central hole. A rotating shaft is inserted to a predetermined position in a hole of each of the plurality of cylindrical forming bodies, and adjacent cylindrical forming bodies are connected to each other. in this case,
The cylindrical forming body is shaped so that the cylindrical forming body has a strength that does not break in the step of inserting the rotating shaft into the center of the cylindrical forming body. The cylindrical roller is integrally formed on the outer peripheral surface of the rotating shaft by forming a cylindrical molded body through a step of curing and curing the cylindrical formed body inserted on the outer periphery of the rotating shaft.

(4) Curing and curing After pressure molding, it takes several hours to several days for the resin to be removed from the mold and develop sufficient strength.
It may be left at room temperature or cured in water or steam, but preferably cured in an autoclave. In addition, when the amount of water for forming a cured body is missing or insufficient, steam curing is preferable.
In particular, curing in an autoclave is preferred. The autoclave curing is performed at a saturated vapor pressure of 7.15 kg / cm ² , 1
It is performed at 65 ° C. or higher, but has a saturated vapor pressure of 9.10 kg / cm ^2.
The above is preferred. The curing time varies depending on the curing temperature, but is 5 to 15 hours under the condition of 175 ° C. 5 N in compressive strength after pressure molding and before starting autoclave curing
/ Mm ² is preferred. If sufficient strength is not developed by autoclave curing,
Explosion of the molded body occurs.

(Preferred Embodiment) FIGS. 1 to 4 show a preferred embodiment of the paper feed roller of the present invention. FIG.
1A to 1F show a preferred embodiment of the paper feed roller of the present invention. FIG. 1 (a) is the same as FIG. 1 (d), FIG.
(E) shows the cylindrical molded body 1 at the center in the paper feed roller shown in the cross-sectional view, a left side view on the left, a front view on the right side, a right side view on the right side, and a front view on the right side. FIG. 2 is a cross-sectional view taken along the line AA as viewed along the line AA. FIG.
(B) and FIG. 1 (c) correspond to FIG. 1 (d) and FIG.
(E) shows the right and left cylindrical molded bodies 2 and 3, the details of each figure being the same as FIG. 1 (a). Each cylindrical molded body is formed from a hydraulic composition and has a length of, for example, 50
１００100 mm.

FIG. 1 (e) is a sectional view of a paper feed roller in which cylindrical molded bodies 1, 2, 3 are inserted around the outer periphery of a supporting / driving rotary shaft 4 and are integrally connected to each other. The rotation axis 4 is
For example, the length is 250 to 350 mm. The cylindrical molded bodies 1, 2 and 3 are preferably firmly integrated with each other with a suitable adhesive, and preferably each cylindrical molded body is also firmly and integrally fixed to the outer periphery of the rotating shaft with a suitable adhesive. Have been. In this case, even after the cylindrical molded bodies 1, 2, 3 are connected and fixed in advance (see FIG. 1D), they are inserted around the outer periphery of the supporting / driving rotary shaft 4 and integrally connected to each other. Alternatively, the cylindrical molded bodies 1, 2, 3 may be sequentially inserted around the outer periphery of the rotating shaft 4 and integrally connected to each other. The cylindrical molded bodies 1, 2, and 3 are inserted into the rotating shaft after molding, demolding, and curing.
They may be connected and fixed integrally with each other, or may be connected and fixed integrally with each other by being inserted into a rotating shaft immediately after molding and demolding and curing.

A cylindrical concave portion 1a is provided on the inner peripheral surface on the right side of the cylindrical molded body 1, and a cylindrical convex portion 1b is provided on the left end portion. The convex portion 2a and the cylindrical concave portion 3a on the right inner peripheral surface of the cylindrical molded body 3 are fitted tightly. Cylindrical molded body 1,
The outer diameter and the inner diameter of 2, 3 are the same, and when the cylindrical molded bodies are connected to each other, the outer peripheral surface and the inner peripheral surface of each cylindrical molded body are continuous, and the central hole and the outer peripheral surface are concentric. And extend parallel to the axis of rotation and longitudinally. This is the same for the other embodiments.

Although not shown, for example, in the case of manufacturing a cylindrical roller of 450 mm, a molded body having an effective length of about 90 mm (the length of a formed portion not including the concave portion of the fitting portion) is manufactured in advance. Five are inserted on the rotating shaft and fixed integrally.

FIGS. 2A to 2D show another embodiment of the paper feed roller of the present invention. In the present embodiment, the combination of the cylindrical concave portion on the inner peripheral surface and the cylindrical convex portion at the end of each cylindrical molded body is slightly changed from that shown in FIG. 1, and the five cylindrical molded bodies are connected. (Two cylindrical molded bodies 7 and 8 are used). Since the shape and the like are clear by referring to the drawings, the description is omitted.

FIGS. 3A to 3D show still another embodiment of the paper feed roller of the present invention. FIG. 3 (a)
FIG. 3D shows the cylindrical molded body 10 at the center in the paper feed roller shown in the sectional view of FIG. 3D, a left side view on the left, a front view on the right side, a right side view on the right side, and a right side view on the right. A- in front view
FIG. 2 is a cross-sectional view taken along the line AA as viewed along the line A. FIG.
FIG. 3B shows a cylindrical molded body 11 used on the right and left sides in FIG. A concave portion 10 a is provided at both ends of the cylindrical molded body 10, and a concave portion 11 a is provided at one end of the cylindrical molded body 11. FIG. 3C shows a connecting member 12 for connecting the cylindrical molded bodies 10 and 11. The outer diameter of the connecting member 12 is the concave portion 10a of the cylindrical molded body 10, 11,
The inside diameter of the connecting member is substantially the same as the inside diameter of the cylindrical molded bodies 10 and 11.
The connecting member can be formed of the same material as the cylindrical molded bodies 10 and 11, or can be formed of another appropriate material such as metal or ceramic. FIG. 3 (d)
The cylindrical molded bodies 10, 11, 11 and the connecting member 12
Is shown in a sectional view in a state in which the cylindrical moldings 10, 11, 1 are assembled in the same manner as in the embodiment shown in FIG.
1 and the connecting member 12 are assembled to the rotating shaft and integrally fixed.

FIG. 4 shows still another embodiment of a cylindrical molded body. In this embodiment, the fitting structure of the slit and spline nesting type is adopted, and the fitting force between the connected cylindrical molded bodies can be improved. FIG. 5 shows a fitting structure in which the outer peripheral surface of the convex portion and the inner peripheral surface of the cylindrical concave portion of the corresponding cylindrical molded body are each polygonal.

[0041]

EXAMPLES Cylindrical moldings (outer diameter 32 mm, inner diameter 12 mm, length 7) made of a hydraulic composition having the composition shown in Table 1 below
0 mm), attached to a rotating shaft made of SUM (diameter 12 mm × length 430 mm), integrally assembled and fixed to obtain a paper feed roller having the structure shown in FIG. The paper feed rollers of Examples 1 to 4 were manufactured by the above method. Assembling of the cylindrical molded body and the rotating shaft was performed using the first method. That is, after the cylindrical molded body of (a), (b), and (c) shown in FIG. 1 is molded, demolded, cured, and cured, the epoxy resin is used to form (a) the central part using an epoxy adhesive. And three rollers (b) and (c) are attached to the rotating shaft, and 35
The length was set to 0 mm.

(1) Deflection Test As a comparative example 1, a hollow paper feed roller made of SUM free-cutting steel having a diameter of 12 mm was manufactured.
A roller portion (length 350 mm, outer diameter 32 mm) made of a hydraulic composition was integrally fixed to the outer periphery of a SUM rotary shaft (diameter 12 mm × length 430 mm).

The paper feed rollers of Examples 1 to 4 and Comparative Examples 1 and 2 obtained above were set to a span of 300 mm and
A load of 196 N (20 kgf) was applied downward to the midpoint of the two fulcrums, and the amount of deflection when a centralized load was applied was measured. The results are shown in Table 2 below.

(Table 2) Deflection amount (mm) Remarks Example 1 (plain joint) 0.38 Example 2 (in-row joint) 0.21 Insertion depth 10 mm Example 3 (in-row joint) 0.19 Insert Depth 15 mm Example 4 (in-row splice) 0.19 Using fitting metal fittings Comparative Example 1 (SUM free-cutting steel) 0.56 Diameter 12 mm Reference example (integral molding) 0.19

As can be seen from the above results, the amount of flexure in Example 1 in which the cylindrical molded body was simply joined by abutting the ends on the rotating shaft was slightly large (0.38 mm), but was sufficiently practical. It was within the range that I could endure. Further, the connecting end portions of the cylindrical molded bodies connected to each other have a shape to be fitted to each other, and the cylindrical molded bodies are connected to each other at these end portions by fitting. Of the paper feed roller made of SUM free-cutting steel had a smaller amount of deflection than that of Comparative Example 1 and was excellent. Examples 2 to 4 exhibited the same amount of flexure as the reference example in which a roller made of a hydraulic composition was integrally fixed to the outer periphery of the SUM rotary shaft.

(2) Workability test With respect to the other paper feed rollers of Examples 2 to 4 and Comparative Examples 1 and 2, the centerless grinder was used to increase the grinding accuracy at a predetermined working speed by +/-. Grinding was performed at 0.002 mm. In Comparative Example 2, the rotating shaft (SUM diameter 12 mm × length 430 m)
m) around an alumina sintered body (diameter 32 mm x length 35)
(0 mm). The results are shown in Table 3 below.

(Table 3) Processing speed Grinding speed Remarks mm / min. mm Example 2 (joint brazing) 1650 ± 0.002 Example 3 (joint brazing) 1650 ± 0.002 Example 4 (joint brazing) 1650 ± 0.002 Comparative Example 1 (SUM free-cutting steel) 1500 ± 0. 002 Standard Comparative Example 2 (alumina sintered body) 120 ± 0.002

As can be seen from the results shown in Table 3 above, Examples 2 to 4 of the present invention show more excellent workability as compared with Comparative Example 1 of the paper feed roller made of SUM free-cutting steel. It can be seen that the workability was significantly improved as compared with Comparative Example 2 in which the roller portion made of the sintered body was inserted on the rotating shaft and fixed integrally.

[Brief description of the drawings]

FIG. 1 (a) shows a cylindrical molded body 1 at the center in one embodiment of a paper feed roller according to the present invention, a left side view on the left, a front view on the right, and a right side on the right. The figure shows a cross-sectional view taken along the line AA of the front view taken along the line AA of the front view, and (b) shows the cylindrical molded body 2 on the right side, and (c) shows the same. Shows the cylindrical molded body 3 on the left side,
(D) is a cross-sectional view showing a state in which the cylindrical molded bodies 1, 2, 3 are connected. (E) is a state in which the cylindrical molded bodies 1, 2, 3 are inserted around the outer periphery of the rotating shaft 4 and connected. FIG. 4 is a cross-sectional view showing a state in which the paper feed roller is integrally fixed and assembled, and FIG.

FIG. 2 (a) shows a cylindrical molded body 6 in the central part in another embodiment of the paper feed roller according to the present invention, a left side view on the left, a front view on the right, and a right side on the right. A sectional view taken along the line AA of the front view and a sectional view taken along the line AA of the front view are shown on the right side, and (b) similarly shows the cylindrical molded body 7 positioned on both right and left sides, (C) similarly shows the cylindrical molded body 8 at the left and right end portions, and (d) inserts and connects the cylindrical molded bodies 1, 2, and 3 around the outer periphery of the rotating shaft 4, and integrally fixes them. FIG. 3 is a cross-sectional view of the paper feed roller in an assembled state.

FIG. 3 (a) shows a cylindrical molded body 10 at a central portion in still another embodiment of the paper feed roller according to the present invention,
A left side view on the left, a front view on the right side, a right side view on the right side, and A cut along the line AA of the front view on the right.
FIG. 2B is a cross-sectional view taken along the line A. FIG. 2B shows a cylindrical molded body 11 similarly positioned on both left and right sides, and FIG. Molded body 11,
11D is a cross-sectional view of the paper feed roller in a state where the cylindrical molded bodies 10, 11, and 12 are inserted and connected to the outer periphery of the rotating shaft 4, connected, and integrally fixedly assembled.

FIG. 4 shows another cylindrical molded body used to make the paper feed roller according to the present invention, a left side view on the left, a front view on the right side, a right side view on the right side, and a front view on the right. FIG. 2 is a cross-sectional view taken along the line AA of FIG.

FIG. 5 shows another cylindrical molded body used to make the paper feed roller according to the present invention, and the outer peripheral surface of the convex portion and the inner peripheral surface of the cylindrical concave portion of the corresponding cylindrical molded body are each polygon-shaped. Is shown.

[Brief description of reference numerals]

 1, 2, 3, 6, 7, 8 ... Cylindrical molded body 1a, 3a ... Cylindrical concave part 2a ... Cylindrical convex part 4 ... Rotary shaft 12 ... Connecting member

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Yasuhiko Shimada 585 Tomicho, Funabashi-shi, Chiba Sumitomo Osaka Cement Co., Ltd. F-term in the building materials division (reference) 3F049 CA22 LA02 LA05 LA07 LB01 3F104 AA02 JA03 JB01

Claims (8)

[Claims] 1. A rotating shaft, and a cylindrical roller portion formed by press-molding a mixture comprising a hydraulic composition, curing and curing the mixture, and integrated with the outer peripheral surface of the rotating shaft. A paper feed roller, wherein the cylindrical roller portion is formed by connecting a plurality of cylindrical molded bodies in a rotation axis direction. 2. A method according to claim 1, wherein the connecting ends of the cylindrical molded bodies connected to each other have a shape that fits each other, and the cylindrical molded bodies are connected to each other at these ends by fitting. The paper feed roller according to claim 1. 3. The hydraulic composition according to claim 1, wherein the hydraulic powder is 50 to 50%.
90% by weight, and 10 to 50% by weight of a non-hydraulic powder having an average particle diameter smaller than the average particle diameter of the hydraulic powder by one digit or more.
3. The paper feed roller according to claim 1, comprising a mixed powder comprising: and a processability improver blended in a ratio of 2 to 18 parts by weight with respect to 100 parts by weight of the mixed powder. . 4. The processability improver is selected from a vinyl acetate resin or a copolymer resin with vinyl acetate, an acrylic resin or a copolymer resin with acrylic, a styrene resin or a copolymer resin with styrene, and an epoxy resin. The paper feed roller according to claim 3, wherein the paper feed roller is a powder or an emulsion made of at least one kind of resin. 5. Molding, demolding, and molding from a hydraulic composition, respectively.
Forming a plurality of cylindrical molded bodies having a hole in the center through the curing and curing step, inserting a rotating shaft into the holes of the plurality of cylindrical molded bodies, and adjoining the cylindrical molded bodies. A method for manufacturing a paper feed roller, wherein a cylindrical roller portion is integrally formed on an outer peripheral surface of a rotating shaft by coupling. 6. The cylindrical molded bodies to be connected to each other are formed into a shape that fits each other, and the cylindrical molded bodies are connected to each other by fitting at these ends. 5. The method for manufacturing a paper feed roller according to 5. 7. Molding and demolding each from the hydraulic composition to obtain a plurality of cylindrical forming bodies having a hole in the center, inserting a rotating shaft into the holes of the plurality of cylindrical forming bodies, and After connecting the adjacent cylindrical forming bodies, a step of curing and curing the cylindrical forming bodies is performed to form a cylindrical formed body, and a cylindrical roller portion is integrally formed on the outer peripheral surface of the rotating shaft. A method for manufacturing a paper feed roller. 8. A method according to claim 1, wherein the connecting ends of the cylindrical molded bodies to be connected to each other are formed into shapes that fit each other, and the cylindrical molded bodies are connected to each other at these ends by fitting. 7. The method for manufacturing a paper feed roller according to item 7.