JP2012061729A - Method of manufacturing elastic roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of obtaining a highly accurate elastic roller at low cost by supporting a lower end surface of a core metal more reliably, irrespective of a processing state of the lower end surface of the core metal.SOLUTION: A method of manufacturing the elastic roller includes a process of supplying a plurality of core metals continuously to a crosshead connected to an extruder and covering the peripheries of respective core metals with a raw rubber composition while carrying the core metals vertically downward. The process includes a step of carrying the core metal vertically downward while supporting the lower end surface of the core metal extruded from the crosshead in a support surface of a core metal-supporting member. When the lower end surface of the core metal extruded from the crosshead is tilted to a support surface of the core metal-supporting surface, the core metal-supporting member can support the core metal while bringing the lower end surface of the core metal into surface contact with the support surface of the core metal-supporting member.

Description

  The present invention relates to a method for manufacturing an elastic roller used in an electrophotographic apparatus or the like.

  Patent Document 1 discloses the following method as a method for manufacturing an elastic roller whose core is covered with rubber, which is used for a charging roller, a conveyance roller, or the like in an electrophotographic apparatus or the like. That is, while continuously supplying a metal core to the cross head, supplying a rubber melt to the cross head from an extruder connected to the cross head, and co-extruding the metal core and the rubber composition from the cross head Thus, the method includes a step of coating the periphery of the core metal with a rubber composition. At this time, if the mandrel extruded vertically downward from the crosshead is allowed to fall freely, the coating of the rubber composition covering the periphery of the mandrel is partially stretched by the weight of the mandrel, and the thickness May be difficult to manage. For this reason, the metal core is conveyed vertically downward while the lower end surface of the metal core extruded from the cross head is supported by a support member.

JP 2005-227754 A

  However, according to the study by the present inventors, some of the core bars are not processed at right angles to the peripheral surface of the core bar. When trying to support the end surface of such a core metal with the support member described in Patent Document 1, the core metal is supported by a point, and the position of the core metal may be shifted during the conveyance vertically downward. It was. A plurality of core bars continuously extruded from the cross head are connected by a layer of a rubber composition covering the outer periphery thereof. For this reason, the vibration due to the deviation is transmitted to the core metal that is coextruded together with the rubber composition at the exit of the crosshead, and the thickness of the layer of the rubber composition covering the periphery of the core metal May be non-uniform.

  Accordingly, an object of the present invention is to provide a method for obtaining a highly accurate elastic roller at a low cost by more reliably supporting the lower end surface of the core metal regardless of the state of processing of the lower end surface of the core metal. is there.

The method for producing an elastic roller according to the present invention is such that a plurality of metal cores are continuously supplied to a crosshead connected to an extruder, and each core metal is conveyed vertically downward, while surrounding the core metal is a raw rubber. A method for producing an elastic roller having a step of coating with a composition,
The step includes a step of conveying the core metal vertically downward while supporting the lower end surface of the core metal extruded from the cross head on the support surface of the core metal support member,
The support surface of the cored bar support member is configured to be tiltable with respect to the conveying direction of the cored bar, and the cored bar support member has a lower end surface of the cored bar extruded from the crosshead. When the metal core is inclined with respect to the support surface, the metal core can be supported in a state where the lower end surface of the metal core and the support surface of the metal core support member are in contact with each other.

  ADVANTAGE OF THE INVENTION According to this invention, the method of obtaining a highly accurate elastic roller at low cost can be provided by supporting the lower end surface of a metal core more reliably irrespective of the processing state of the lower surface of a metal core. .

1 is a diagram schematically showing a configuration of an electrophotographic apparatus using a contact charging type transfer unit. It is a figure which shows an elastic roller typically. It is the figure which showed the manufacturing apparatus of the elastic roller typically. It is a cross-sectional schematic diagram of the crosshead connected with the extruder. (A) is the figure which showed the core metal supporting member conventionally known typically, (b) is a case where the contact area of a metal core lower end surface and a metal core support surface becomes small. It is the figure shown in. It is the figure which showed typically the metal core support member which concerns on this invention, (a) is a compression spring type, (b) is a spherical body holding type, (c) is a metal core with a sponge type inclination member. It is the figure which showed the support member typically. It is the figure which showed typically the run-out measurement of the metal core. It is the figure which showed typically the shift | offset | difference measurement of a metal core lower end surface and a metal core support surface. It is the figure which showed the cutting | disconnection of an elastic roller typically, (a) is a figure before cutting, (b) is a figure showing the elastic roller after cutting | disconnection.

  According to the present invention, it is possible to mitigate the influence of the inclination of the lower end surface of the core metal that is given to the support state between the lower end surface of the core metal extruded from the cross head and the support member. As a result, since a series of conveyance of the cored bar vertically downward can be performed more stably, a highly accurate elastic roller can be stably produced. The elastic roller obtained by the present invention can be used for a charging roller, a conveying roller and the like in an electrophotographic apparatus as shown in FIG. The electrophotographic apparatus of FIG. 1 has a photoconductor 11 as an image carrier rotating in the direction of an arrow, a charging member 12 for uniformly charging the photoconductor 11, and a toner image on the photoconductor 11 on a recording medium P. A transfer roller 14 for transferring and a developing roller 13 disposed in contact with the photosensitive member 11 are provided. Moreover, the elastic roller 23 can be composed of a cored bar 21 and a conductive elastic layer 22 produced using a raw rubber composition as shown in FIG.

  The present invention will be described in detail below with reference to the drawings.

<Crosshead extrusion molding device>
FIG. 3 shows an example of a crosshead extrusion molding apparatus applicable to the elastic roller manufacturing method of the present invention. This apparatus has an extruder 60, a crosshead 40, a cored bar supply unit 50, and a cored bar take-up unit 70 described later. These are described below.

[Extruder]
As shown in FIG. 4, the extruder 60 includes an inlet 61 for feeding the raw rubber composition 1, a cylinder 62 and a screw 63 for conveying the raw rubber composition 1 while plasticizing and kneading, and further plasticizing and kneading. It has a discharge port 64 for discharging the raw rubber composition. Installation of a mesh and a mesh holder for the purpose of promoting kneading of the raw rubber composition 1 and removing foreign matter is permitted at the discharge port 64. The rubber discharge port 64 of the extruder 60 is connected to the introduction port 45 of the outer die 42 constituting the cross head 40.

[Crosshead]
In the present invention, the crosshead 40 is installed so that the cored bar is conveyed in the vertical direction. This reduces the influence of the member that contacts the core metal 21 during the extrusion and exerts an external force and the influence of the weight of the core metal 21 to suppress the center deviation due to the gravity effect during the core metal extrusion, and the center deviation is small. This is to obtain a highly accurate roller. The accuracy of installation of the crosshead 40 in the vertical direction of the axis 47 is as follows. That is, the axis 47 should be as close as possible to the direction of gravity. However, in consideration of the machining accuracy of the extruder and the crosshead, the deviation from the direction of gravity is preferably 1 degree or less. Within the range is particularly preferred.

  The cross head 40 includes at least an outer die 42, an inner die 41, a nipple 43, and a die 44, and the outer die 42 and the inner die 41 constitute an annular flow path 46. The inner die 41 has a through hole in the same direction as the central axis of the annular flow path 46, and can be mounted with the core bar 21 supplied from the core bar feed roller 53 of the core bar supply unit 50. A die 44 is provided at the tip of the annular channel 46, and the material rubber composition 1 formed in a cylindrical shape is covered with the core metal 21 to become the elastic roller 23, and is discharged vertically downward from the die 44.

[Core supply unit]
A cored bar supply unit 50 is installed at the upper end of the crosshead 40 and continuously supplies a plurality of cored bars to the internal through-hole of the inner die 41 of the crosshead 40. The cored bar supply unit 50 includes a mechanism for taking out the cored bar 21 from the cored bar stocker 52 and supplying the cored bar 21 to the cored bar feeding roller 53 in the cored bar supply unit. The core metal feed roller 53 is formed using aluminum, brass, copper, or an alloy thereof in addition to a resin such as polyamide, PTFE (polytetrafluoroethylene), polyacetal, or the like so as not to damage the core metal. May be. Further, by changing the feed rate regularly at a period corresponding to the length of the core metal, the outer diameter shape of the elastic roller can be arbitrarily changed to be, for example, a crown shape or an inverted crown shape.

[Core collection unit]
The metal core take-up unit 70 can include a metal core support mechanism 100 that supports the metal core lower end surface 24 of the elastic roller 23 extruded from the die 44 while synchronizing with the speed at which the elastic roller 23 is pushed out. Furthermore, the core bar take-up unit 70 is allowed to include a cutting blade 71 for dividing the extruded elastic roller 23, an auto hand 72 for taking out the elastic roller, a pallet 73 on which the elastic roller 23 is placed, and the like. .

[Core support mechanism]
A cored bar support mechanism 100 shown in FIG. 3 includes a support member 102 and a reaction force load member 101. Specifically, the support member 102 applies a substantially constant reaction force to the elastic roller 23 until the core bar lower end surface 24 of the elastic roller 23 extruded from the cross head contacts the support member 102 and is separated by the cutting blade 71. It is connected to the reaction force load member 101 for loading. In the embodiments to be described later, an air cylinder is used as the reaction force load member 101, but other known configurations that can generate a substantially constant reaction force such as a hydraulic cylinder, a brake by friction, electricity, or magnetic force can be used. .

  FIG. 5A shows a schematic diagram of a conventional support member 102. The conventional support member is composed of a member 104 having a core metal support surface 103 and a support portion 106, and the support surface 103 is different from the present invention with respect to the transport direction of the core metal extruded from the crosshead. It was not designed to tilt. Conventionally, the member 104 and the support portion 106 are made of a structure or material that does not tilt due to contact with the metal core support surface 103 such as metal or plastic.

  Next, FIGS. 6A to 6C are schematic views of the cored bar supporting member according to the present invention. The support member 102 used in the present invention includes a core metal support surface 103 that is tiltably contacted with the lower end surface 24 of the core of the elastic roller, and an inclined member 105 that holds the core metal support surface so as to be tiltable. Can do. The support surface 103 supports the lower end surface 24 of the core bar extruded from the cross head, and is configured to be tiltable with respect to the transport direction of the core bar. Further, the cored bar support member can support the cored bar in a state where the cored bar lower end surface 24 and the support surface 103 are in contact with each other when the cored bar lower end surface is inclined. For this reason, as shown in FIG. 5B, even if the core metal 21 whose end surface is not machined at right angles to the peripheral surface is used, the core metal support surface 103 is the lower end surface as in the prior art. 24 is not supported by a point, and can be conveyed in the vertical direction without shifting the position of the cored bar.

  In addition, if the core metal support surface 103 and the inclined member 105 satisfy the requirements of the support member used in the present invention, even if the surface of the inclined member 105 is the core metal support surface 103 as shown in FIG. good. As shown in FIGS. 6A and 6C, the support member 102 may include a member 104 having a cored bar support surface 103 and an inclined member 105.

  The member 104 having the metal core support surface 103 used in the present invention can be formed using a material selected as necessary. For example, the tool steel SK-5 defined in JIS G 3311 is processed. It can be used as the member 104. The member 104 may be a known material as long as it can smoothly transmit the inclination of the inclined member 105 to the metal core support surface 103, and a known material such as metal or plastic can be used.

The inclined member 105 is easily inclined by a reaction force applied by contact between the metal core lower end surface 24 and the metal core support surface 103, and the metal core lower end surface 24 and the metal core support surface 103 are parallel to each other. Any known configuration can be used. Specifically, as the inclined member 105, a cushion type using an elastic body made of rubber or elastomer or a compression spring type using a compression spring can be used. In the case of the cushion type, the material of the inclined member 105 includes natural rubber, butadiene rubber, styrene butadiene rubber (SBR), nitrile rubber, ethylene propylene rubber (EPDM), chloroprene rubber (CR), nitrile butadiene rubber (NBR), epichlorohydrin. In addition to rubber such as rubber, butyl rubber, silicone rubber, urethane rubber, and fluorine rubber, low density polyethylene; high density polyethylene; linear low density polyethylene; polyethylene-based resin such as ethylene-vinyl acetate copolymer resin, and polypropylene resin , Acrylonitrile-butadiene-styrene resin, polystyrene resin, fluororesin, polyamide 6; polyamide 66; polyamide resin such as MXD6, polyolefin elastomer, styrene-isoprene copolymer resin; - ethylene - butene copolymer resin; a styrene - ethylene - propylene copolymer resins such as styrene-based elastomer, may be used resins such as polyester elastomer. Moreover, it is also possible to mix and use 2 or more types in combination. In the case of the compression spring type, a material used for a known spring such as metal or resin can be used as the spring material.
In addition to this, as shown in FIG. 6B, a flat sphere 107 having a core metal support surface 103 in contact with the lower end surface 24 of the metal core and a conical hole holding the flat sphere 107 are installed. A sphere-holding inclined member 105 composed of the sphere-holding portion 108 can be used as the support member 102. The sphere 107 with a plane is rotatably held by the sphere holder 108, and the cored bar support surface 103 can be tilted in accordance with the tilt of the lower end surface of the cored bar. In addition, the spherical body 107 with a plane can be formed by cutting the tool steel SK-5, for example. Moreover, the spherical body support part 108 can be formed, for example with the said tool steel SK-5. For the purpose of preventing deformation of the outer peripheral surface of the conductive layer 22 of the elastic roller 23, it is preferable to use a sphere-holding type that can easily reduce the force for inclining the core metal support surface as the inclined member. The sphere holding type can reduce friction by filling the interface between the flat sphere 107 and the sphere holding portion 108 with a lubricant, air, oil, water, or the like. In addition, the sphere portion of the flat sphere 107 constituting the boundary surface and the sphere holding portion 108 may be subjected to a known surface treatment for reducing frictional resistance or improving wear resistance, such as tetrafluoroethylene treatment or nitriding treatment. Permissible.

  Examples of the inclined member include a sponge type in which an elastic body used in a cushion type is a sponge-like elastic body. As shown in FIG. 6C, the sponge type uses a porous body made of rubber, thermoplastic elastomer, or the like as the inclined member 105, and supports the core metal on the inclined member 105 of the porous body. A member 104 having a surface 103 is provided. A well-known joining member such as an adhesive can be used for joining the inclined member 105 of the porous body and the member 104 having the metal core support surface 103 on the surface. Furthermore, the member 104 having the cored bar supporting surface 103 and the inclined member 105 can be simultaneously molded by using known multilayer molding used for rubber or resin molding. The foaming form of the sponge-type sponge is not limited in any way, and continuous foam, single foam, and a combination of the continuous foam and the single foam are also acceptable. Known foaming forms such as capsules and water foaming can be used.

  Further, in order to easily prevent slippage between the metal core support surface 103 and the metal core end surface 24 when the metal core support surface 103 and the metal core end surface 24 come into contact with each other, the metal core support surface 103 is provided. The surface can be anti-slip treated. Specifically, the anti-slip treatment includes a method of bonding a material having a large friction coefficient with a core metal end surface such as rubber to the core metal support surface before the anti-slip treatment, or increasing the surface roughness of the core metal support surface by machining. There are ways to do it. Furthermore, an adhesive member typified by an adhesive tape or the like can be provided on the core metal support surface before the anti-slip treatment. In consideration of wear and wear due to contact with the lower end surface of the core metal, a layer containing hard particles such as diamond and cubic boron nitride is formed on the core metal support surface before the anti-slip process as an anti-slip process. A method of increasing the thickness is preferable. The layer containing hard particles such as diamond and cubic boron nitride can be formed on the core support surface before the anti-slip treatment by a metal bond method or an electrodeposition method. The metal bond method and the electrodeposition method are methods for fixing hard particles used for manufacturing a grinding wheel or a rotary cutting blade used for general industrial use to an adherend.

<Method for producing elastic roller>
Hereinafter, the manufacturing method of the elastic roller according to the present invention will be described with reference to the drawings. The raw rubber composition 1 charged into the inlet 61 of the extruder is sheared by the screw 63 in the cylinder 62 and is conveyed to the outlet 64 while being plasticized and kneaded. Subsequently, it is conveyed to the introduction port 45 of the crosshead 40. A mesh and a mesh holder can be attached between the discharge port 64 and the introduction port 45 for the purpose of removing foreign substances. The raw rubber composition 1 is changed into a flow direction by the cross head 40 and is formed into a cylindrical shape by an annular flow path 46 constituted by the outer die 42 and the inner die 41 to form a rubber cylinder. The rubber cylindrical body is coated on the core metal 21 conveyed from the core metal supply unit 50 to the through hole of the inner die 41, adjusted to a desired outer diameter with a die 44, and extruded as an elastic roller 23. The

  The extruded elastic roller 23 is pushed out in its entirety while the speed is synchronized with the support mechanism 100 while the lower end surface 24 of the core metal is supported by the support mechanism 100 that has been stationary. At this time, even when the lower end surface 24 of the core metal and the core metal support surface 103 are not parallel, the following occurs. When the metal core lower end surface 24 comes into contact with the metal core support surface 103, the reaction force between the metal core lower end surface 24 and the metal core support surface 103 caused by this contact causes the metal core support surface 103 to be parallel to the metal core lower end surface 24. The contact area with the lower end surface 24 of the metal core increases. That is, the support surface 103 and the cored bar lower end surface 24 are in a surface contact state. For this reason, a shift | offset | difference does not arise between the metal core lower end surface 24 and the metal core support surface 103 during the metal core lowering. In this way, the influence of the inclination of the lower end surface of the core bar on the support state between the lower end surface 24 of the core metal and the support member is alleviated, and the outer peripheral surface of the conductive layer 22 of the elastic roller 23 has a poor outer diameter such as irregularities. It is possible to stably manufacture an elastic roller having no friction.

  Furthermore, by making the cored bar support surface 103 a non-slip surface, the coefficient of friction between the cored bar lower end surface 24 and the cored bar support surface 103 is increased, and the gap between the cored bar lower end surface and the cored bar support surface is increased. Deviations are even less likely to occur.

  Next, the elastic roller 23 pushed out from the cross head has the coating film of the raw rubber composition 1 on the uppermost end portion of the core metal cut by the cutting blade 71. Simultaneously with the cutting, the closed cutting blade 71 and the support mechanism 100 are moved at a speed faster than the core metal feed speed in the core bar extrusion direction, and the elastic roller 23 coated in a cylindrical shape with the raw rubber composition 1 is moved one by one. Separate into books. The elastic roller 23 supported by the support mechanism 100 and the cutting blade 71 is placed on the pallet 73 while being turned by the reversing auto hand 72.

  The resulting elastic roller is heated and vulcanized in a hot air oven as necessary, and the outer peripheral surface is further polished, and a layer is further provided on the outer periphery for resistance adjustment and surface property adjustment. For example, a charging roller or a conveyance roller can be obtained.

<Core>
The core metal used in the present invention can be appropriately selected from cores known in the field of elastic rollers used in electrophotographic apparatuses and the like. Moreover, an adhesive agent etc. can also be suitably apply | coated to a metal core, As an adhesive agent, an electroconductive hot-melt type thing can be mentioned, for example.

<Raw rubber composition>
Examples of the polymer constituting the raw rubber composition for coating the core metal include natural rubber, butadiene rubber, styrene butadiene rubber (SBR), nitrile rubber, ethylene propylene rubber (EPDM), chloroprene rubber (CR), and nitrile butadiene rubber. (NBR), epichlorohydrin rubber, butyl rubber, silicone rubber, urethane rubber, fluorine rubber and the like can be mentioned, and any of these can be used.

Examples of the conductive powder dispersed in the polymer include carbons such as carbon black and conductive carbon, metal oxides such as graphite, TiO ₂ , SnO ₂ , and ZnO, a solid solution of SnO ₂ and Sb ₂ O ₃ , ZnO And double oxides such as a solid solution of Al ₂ O ₃ , metal powders such as Cu and Ag, and conductive fibers. The conductive powder is preferably added to the raw rubber composition in an amount of 5 parts by mass to 200 parts by mass with respect to 100 parts by mass of the polymer raw material. Furthermore, a vulcanizing agent, an inorganic filler, other known vulcanization accelerators, process oils, and the like are appropriately added to the raw rubber composition. Examples of the vulcanizing agent include sulfur, metal oxide, and organic oxide. Examples of the inorganic filler include carbon black, talc, and clay.

  Hereinafter, the present invention will be described in more detail using Examples and Comparative Examples.

  First, the materials shown in Table 1 were mixed with an open roll to prepare a raw rubber composition (prescription 1) used in each example.

  Subsequently, in order to form the obtained raw rubber composition around the core metal, in each example, a die having an inner diameter of 10 mm (diameter) is set in an extrusion apparatus schematically shown in FIG. The temperature of the crosshead was adjusted to 80 ° C. Next, a cored bar having a diameter of 6 mm and a total length of 252 mm, in which an adhesive was applied in advance to a region excluding both ends 10 mm, was prepared. The adhesive used was an electrically conductive hot melt type.

The core metal has a maximum circumferential runout of the core metal end face of the other end of 5 μm or less when one end of the core metal 21 is supported by the support mechanism 80 by the method shown in FIG. And each having a maximum circumferential run of 8 μm or more and 12 μm or less (core metal 2 group) was used in each example.
Using the apparatus shown in FIG. 3, these metal cores are continuously extruded simultaneously with the raw rubber composition, and a cylindrical raw rubber composition is formed around the core metal to obtain the elastic roller shown in each example. It was. In addition, surface roughness Ra of the metal core support surface shown in each example was measured according to JIS B 0601.

Example 1
In Example 1, as shown in FIG. 6B, a support member in which the inclined member 105 is a sphere holding type is used. That is, the inclined member that holds the sphere 107 with a plane having a diameter of 15 mm and having a plane with a diameter of 10 mm on the surface by the sphere holder 108 is used. The flat sphere 107 was obtained by cutting tool steel SK-5 defined in JIS G 3311. The spherical body holding portion 108 was made of carbon steel for mechanical structure S45C defined in JIS G 4051. As a non-slip treatment, diamond powder having a particle size of No. 200 (particle size of 0.1 mm) was electrodeposited and fixed on the surface of the flat sphere 107 using nickel to form the cored bar support surface 103. The surface roughness of the metal core support surface was Ra 16 μm.

The support member 102 waited about 100 mm below the lower surface of the die 44, and the lower end surface of the core metal to be extruded and the core metal support surface were brought into contact with each other to perform extrusion molding of the elastic roller.
In addition, about the shift | offset | difference of a metal core lower end surface and a metal core support surface, it measured as follows. As shown in FIG. 8, laser light from a CCD laser displacement sensor (trade name: LK-010, manufactured by Keyence) is applied in four directions on the outer peripheral surface of the elastic roller 2 mm above the lower end surface 24 of the core of the elastic roller. The displacement (displacement) described later was measured by irradiation. When the displacement measured by the displacement sensor changes by 20 μm or more from when the lower end surface of the core bar pushed out from the cross head comes into contact with the core bar support surface until it is cut by the cutting blade 71 as shown in FIG. As a result, 10,000 elastic rollers were molded and the occurrence rate of deviation (deviation rate%) was counted.

  Further, on the outer peripheral surface of the elastic roller, the occurrence rate of those having a concave or convex shape with a height difference of 40 μm or more was counted to obtain the appearance defect rate (%). The concavo-convex shape was measured using a laser outer diameter measuring machine by dividing the elastic roller into 1 mm pitch in the length direction and 10 ° pitch in the circumferential direction. The said laser outer diameter measuring machine used the brand name: LS-7000 and the product made by Keyence. The results are shown in Table 3.

  As shown in Table 3, the elastic roller obtained in Example 1 is less likely to be displaced between the lower end surface of the cored bar and the cored bar support surface, and can stably form a highly accurate elastic roller according to the present invention. I was able to.

(Example 2)
In Example 2, a spherical holding type inclined member 105 including a sphere 107 having a diameter of φ10 mm on the surface and a sphere 107 having a diameter of φ8 mm on the surface is used. The core metal supporting surface 103 was formed by applying an anti-slip treatment with crystal boron nitride. The surface roughness of the cored bar support surface was Ra 26 μm. An elastic roller was produced in the same manner as in Example 1 except that this support member was used. The materials used for the sphere 107 and the sphere holder 108 are the same as those in the first embodiment. The results are shown in Table 3.

Example 3
In Example 3, instead of anti-slip treatment with diamond powder, double-sided tape (trade name: manufactured by Nystack Nichiban Co., Ltd.) was applied to the surface of the sphere 107 as anti-slip treatment, and the cored bar support surface 103 was formed. An elastic roller was produced in the same manner as in Example 1. The results are shown in Table 3. The surface roughness of the cored bar supporting surface 103 was Ra 5.4 μm.

Example 4
In Example 4, instead of the anti-slip treatment with diamond powder, a chloroprene rubber sheet manufactured by Togawa Rubber Co., Ltd. having a thickness of 1 mm was installed on the surface of the sphere 107 as an anti-slip treatment, and the core metal support surface 103 was formed. In the same manner as in Example 1, an elastic roller was produced. The chloroprene rubber sheet was attached to the sphere surface using a hot melt adhesive. The surface roughness of the cored bar support surface was Ra 1.2 μm. The results are shown in Table 3.

(Example 5)
In Example 5, the surface of the flat sphere 107 was not subjected to anti-slip treatment, and an elastic roller was formed in the same manner as in Example 1 except that the arithmetic average roughness Ra of the surface of the cored bar support surface 103 was 0.2 μm by buffing. Was made. The arithmetic average roughness Ra is a surface roughness measured according to JIS B 0601. The results are shown in Table 3.

(Example 6)
The materials shown in Table 2 were kneaded with an open roll to prepare a raw rubber composition (Prescription 2).

  In Example 6, a conductive roller was manufactured using a sponge-type metal core support member 102 using an NBR sponge having an Asker C hardness of 15 and a thickness of 5 mm as the inclined member 105. The support member 102 was manufactured by the following process. First, an NBR sponge manufactured by Toho Kogyo Rubber Co., Ltd. was cut into a cylindrical shape having a diameter of 10 mm and a height of 5 mm to obtain an inclined member 105. Next, tool steel SK-5 processed into a disk having a diameter of 10 mm and a height of 1 mm as a member 104 was bonded to one end of the cylindrical NBR sponge with a hot-melt adhesive. Further, a support member 102 having a core metal support surface 103 on its surface is subjected to anti-slip treatment by electrodepositing and fixing diamond powder having a particle size of 200 (particle size: 0.1 mm) on the surface of the member 104 using nickel. Formed. The surface roughness of the cored bar support surface was Ra 33 μm.

  The Asker C hardness was measured using an Asker rubber hardness meter (manufactured by Kobunshi Keiki Co., Ltd.) using a test piece (NBR sponge in Example 6) prepared according to the standard Asker C-type SRIS (Japan Rubber Association Standard) 0101. Is the hardness measured by A conductive roller was produced in the same manner as in Example 1 except that this support member and the raw rubber composition (formulation 2) were used. The results are shown in Table 3.

(Example 7)
The NBR sponge used for the inclined member 105 in Example 6 was changed to an NBR sponge having an Asker C hardness of 40, and the surface roughness of the cored bar support surface 103 was set to Ra 0.2 μm without performing anti-slip treatment on the surface of the member 104. It was. Otherwise, an elastic roller was produced in the same manner as in Example 6. The results are shown in Table 3.

(Example 8)
In Example 8, a compression spring type cored bar support member as schematically shown in FIG. 6A was used. That is, as the inclined member 105, a compression spring having a material of spring steel SWP-A, a spring wire diameter of 0.2 mm, a spring strip number of 0.1 N / mm, a coil diameter of 4 mm, and a spring free length of 4 mm was used. The member 104 used in Example 7 was installed at one end of the compression spring. A support member having a metal core support surface 103 is obtained by electrodepositing and fixing diamond powder having a particle size of 200 (particle size of 0.1 mm) on the surface of the member using nickel as an anti-slip treatment as in Example 1. Produced. The surface roughness of the cored bar support surface was Ra 42 μm. An elastic roller was produced in the same manner as in Example 7 except that this support member was used. The results are shown in Table 3.

Example 9
In Example 9, an elastic roller was produced in the same manner as in Example 8 except that the anti-slip treatment with diamond powder was not performed and the surface roughness of the cored bar supporting surface 103 was set to Ra 0.2 μm. The results are shown in Table 3.

(Comparative Example 1)
In Comparative Example 1, an elastic roller was produced in the same manner as in Example 1 except that a cored bar supporting member without an inclined member was used as shown in FIG. The core metal support member without the inclined member is formed by machining the carbon steel for mechanical structure S45C defined in JIS G 4051 with a lathe so that the core metal support surface 103, the member 104, and the support portion 106 are integrated. The core metal support member 103 was anti-slip treated with diamond powder in the same manner as in Example 1 to form the core metal support surface 103. The results are shown in Table 3. The surface roughness of the cored bar supporting surface 103 was Ra 19 μm.

(Comparative Example 2)
In Comparative Example 2, an elastic roller was produced in the same manner as in Comparative Example 1 except that the anti-slip treatment with diamond powder was not performed and the surface roughness of the cored bar support surface was set to Ra 12 μm. The results are shown in Table 3.

DESCRIPTION OF SYMBOLS 11 ... Photoconductor 12 ... Charging member 13 ... Developing roller 14 ... Transfer roller 21 ... Core metal 22 ... Conductive elastic layer 23 ... Elastic roller 40 ... Cross head 41 ... Inner die 42 ... Outer die 43 ... Nipple 44 ... Die 45 ... Inlet 46 ... Annular channel 50 ... Core metal supply unit 52 ... Core metal stocker 53 ... Core metal feed roller 60 ... Extruder 61 ... Supply port 62 ... Cylinder 63 ... Screw 64 ... Discharge port 70 ... Core metal take-up unit 71 ... Cutting blade 72 ... auto hand 73 ... pallet 100 ... support mechanism 101 ... reaction load device 102 ... support member 103 ... core metal support surface 105 ... tilt member 107 ... sphere 108 ... Sphere holder

Claims (1)

An elastic roller having a step of continuously supplying a plurality of cores to a crosshead connected to an extruder and coating each cored bar with a raw rubber composition while conveying each cored bar vertically downward A manufacturing method comprising:
The step includes a step of conveying the core metal vertically downward while supporting the lower end surface of the core metal extruded from the cross head on the support surface of the core metal support member,
The support surface of the cored bar support member is configured to be tiltable with respect to the conveying direction of the cored bar, and the cored bar support member has a lower end surface of the cored bar extruded from the crosshead. The core metal can be supported in a state in which the lower end surface of the core metal and the support surface of the core metal support member are in contact with each other when inclined with respect to the support surface of the core metal. Roller manufacturing method.