JP2013052476A - Method of polishing tubular elastic body, method of manufacturing elastic roller, and elastic roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of polishing a tubular elastic body, for polishing the tubular elastic body so as to have high deflection accuracy, an elastic roller having an elastic layer of high deflection accuracy, and a method of manufacturing the elastic roller.SOLUTION: The method of polishing a tubular elastic body 7 disposed on the outer peripheral surface of a shaft body 71 includes: a step of gripping a cylindrical outer peripheral surface 17c having an axial length of 8 to 21% of that of the shaft body 71 protruded from the end surface of the tubular elastic body 71c within 10 mm from the end surface of the shaft body 71 by a collet chuck 3; a step of relatively rotating the tubular elastic body 7; and a step of polishing the outer peripheral surface of the tubular elastic body 7 by a grinding stone 4 without adjusting the surrounding environment of the collet chuck 3. The method of manufacturing the elastic roller includes: a step of disposing the tubular elastic body 7 on the outer peripheral surface of the shaft body 71 to manufacture a roller base body 6; and a step of polishing the tubular elastic body 7 by the method of polishing the tubular elastic body 7. The elastic roller manufactured by the manufacturing method has deflection accuracy of 0.10 mm or less.

Description

  The present invention relates to a method for polishing a tubular elastic body, a method for manufacturing an elastic roller, and an elastic roller, and more specifically, a method for polishing a tubular elastic body capable of polishing the tubular elastic body so as to have a high runout accuracy with respect to a shaft body, The present invention also relates to an elastic roller having an elastic layer with high deflection accuracy with respect to a shaft body and an elastic roller manufacturing method capable of manufacturing the elastic roller.

  Various types of image forming apparatuses using an electrophotographic system are employed in laser printers, copiers, video printers, facsimiles, and multifunctional machines of these. Various image forming apparatuses are equipped with elastic rollers such as a charging roller, a developing roller, a transfer roller, a pressure roller, a fixing roller, a paper feed / conveying roller, and a developer supply roller. These elastic rollers usually include a shaft body and an elastic layer disposed on the outer peripheral surface of the shaft body.

  These elastic rollers are generally manufactured by molding a rubber composition on the outer peripheral surface of a shaft body to produce a roller base body having a tubular elastic body and polishing the tubular elastic body of the roller base body. Specifically, as shown in FIG. 6, the end portion of the shaft body 71 of the produced roller original body 6 is gripped by, for example, the collet chuck 50 shown in FIG. An elastic roller can be manufactured by grind | polishing the outer peripheral surface of the tubular elastic body 7 with a grindstone.

  For example, in Patent Document 1, “in a method of grinding a peripheral surface of a rubber roller while rotating a rubber roller with a rod-shaped member protruding from both ends while holding both ends of the rod-shaped member, at least one of the rod-shaped members is disclosed. A collet chuck that is entirely covered with a cover provided with an insertion port for inserting the end, and inserting the end of the rod-shaped member through the insertion port. A step of holding the collet chuck in a positive pressure state, and a step of jetting air from the inside of the collet chuck toward a portion holding the end of the rod-shaped member. And rotating the rubber roller in a state where the inside of the cover is in a positive pressure state and air is being blown out from the inside of the collet chuck. Characterized by a step of grinding the describes a grinding method "of the rubber roller.

  Further, Patent Document 2 states that “the grinding wheel having an outer peripheral surface of the rubber part of the rubber roll provided with a rubber part around the core shaft has a grinding wheel wider than the length of the rubber part. A method of manufacturing a rubber roll that is ground and finished by relative movement of the rubber roll in the radial direction, wherein the grinder is provided with collet chucks facing each other, and both ends of the core shaft are gripped by the collet chuck. The outer peripheral surface of the rubber portion of the rubber roll that rotates by rotating one of the chucks is pressed against the grinding wheel at a first forward speed V1 of 15 to 25 mm / min in the radial direction with respect to the core shaft. A pre-grinding step for grinding by advancing, an intermediate grinding step for grinding by grinding the grinding wheel at a second forward speed V2 lower than the first forward speed V1, The finish grinding step of grinding the grinding wheel by pushing it at a third advance speed V3 lower than the second advance speed V2, and the forward movement of the grinding wheel is stopped at the final position of the finish grinding step. And a method for producing a rubber roll characterized by grinding through a grinding step including a non-firework grinding step for holding in a pressed state.

JP 2002-254220 A Japanese Patent Laid-Open No. 2004-195606

  In an elastic roller mounted on an image forming apparatus, the elastic layer is required to have a small amount of circumferential deflection with respect to the shaft, and in particular in recent image forming apparatuses in which high definition, high speed, and the like are achieved. The elastic roller to be mounted is required to have high runout accuracy in the circumferential direction.

  However, in the conventional manufacturing method in which both end portions of the shaft body in the roller base body are gripped by the collet chuck, the elastic layer cannot be formed with high runout accuracy with respect to the shaft body. When the shaft body is eccentric or the dimensions of the shaft body vary within a tolerance range, an elastic layer having high runout accuracy may not be formed on the shaft body. Furthermore, even when a shaft body having a chamfered portion is used at the end, an elastic layer having high runout accuracy may not be formed on the shaft body.

  Therefore, an object of the present invention is to provide a method for polishing a tubular elastic body, which can polish the tubular elastic body so as to have high deflection accuracy with respect to the shaft body.

  Further, the present invention provides an elastic roller manufacturing method capable of manufacturing an elastic roller having an elastic layer having a high deflection accuracy in the circumferential direction with respect to the shaft body (hereinafter sometimes simply referred to as “runout accuracy”), and the deflection An object of the present invention is to provide an elastic roller having an elastic layer with high accuracy.

  The inventors of the present invention have examined the relationship between the polishing process and the deflection accuracy of the elastic roller. When the tubular elastic body of the original roller is polished by gripping the collet chuck, the polished elastic layer is the collet chuck. It has been found that the shaft layer gripped by the elastic member has a high runout accuracy, but the elastic layer of the elastic roller deteriorates when it is removed from the collet chuck.

  In order to improve the deflection accuracy of the elastic layer, the inventors of the present invention have made the shaft body gripped by the collet chuck stronger or the shaft driven by the collet chuck. When the gripping amount of the body is increased, especially when both ends of the shaft body are gripped by the collet chuck, the shaft body with the shaft line slightly decentered, the shaft body with dimensional variation and / or the chamfered portion at the end If a shaft body having a foreign object attached to or scratched on the gripped portion is used, the shape and / or axis is larger than the shape and axis of the shaft body that is not gripped. It was speculated that the shaft body might be forcibly gripped by the collet chuck as it deviated.

  Based on this assumption, the inventors of the present invention strengthen the grip of the shaft body by the collet chuck or increase the grip amount of the shaft body in order to improve the deflection accuracy of the elastic layer. Contrary to the common sense of gripping, it has been found that by identifying the gripping position of the shaft body by the collet chuck and reducing the gripping amount, it is possible to polish the tubular elastic body of the original roller so as to form an elastic layer with high runout accuracy. It was.

That is, as means for solving the above-mentioned problem,
Claim 1 is a method of polishing a tubular elastic body for polishing an outer peripheral surface of a tubular elastic body disposed on an outer peripheral surface of a shaft body, and is within 10 mm from an end surface of at least one end of the shaft body. The step of gripping a cylindrical outer peripheral surface having an axial length of 8 to 21% with respect to the axial length of the shaft body protruding from the end surface of the tubular elastic body with a collet chuck, and relatively rotating the tubular elastic body A method of polishing the tubular elastic body, and a step of polishing the outer peripheral surface of the tubular elastic body with a grindstone without adjusting the surrounding environment of the collet chuck,
Claim 2 is the method for polishing a tubular elastic body according to claim 1, wherein the shaft body has chamfered parts chamfered at both ends.
Claim 3 is the method for polishing a tubular elastic body according to claim 1 or 2, wherein the gripping step grips both end portions of the shaft body with the collet chuck.
According to a fourth aspect of the present invention, in the gripping step, the one end portion of the shaft body is gripped by the collet chuck, and the other end portion of the shaft body is pressed against a core push stand and held. It is a polishing method of the tubular elastic body described,
5. An elastic roller manufacturing method for manufacturing an elastic roller having an elastic layer disposed on an outer peripheral surface of a shaft body, wherein a tubular elastic body is disposed on the outer peripheral surface of the shaft body, and the original roller. And a step of polishing the tubular elastic body by the method for polishing a tubular elastic body according to any one of claims 1 to 4,
A sixth aspect of the present invention is an elastic roller that is manufactured by the method for manufacturing the elastic roller according to the fifth aspect, and has a circumferential deflection accuracy of 0.10 mm or less.

  The method for polishing a tubular elastic body according to the present invention is within 8 to 21% of the axial length of the shaft body which is within 10 mm from the end face of at least one end of the shaft body and protrudes from the end face of the tubular elastic body. A step of gripping the cylindrical outer peripheral surface of the axial length with a collet chuck, a step of rotating the tubular elastic body relatively, and a step of polishing the outer peripheral surface of the tubular elastic body with a grindstone with the surrounding environment of the collet chuck as normal pressure Therefore, the tubular elastic body can be polished so as to have high runout accuracy. Thus, according to the method for polishing a tubular elastic body according to the present invention, an elastic layer with high deflection accuracy can be formed.

  Since the elastic roller manufacturing method according to the present invention includes the step of polishing the tubular elastic body by the tubular elastic body polishing method according to the present invention, an elastic roller having an elastic layer with high deflection accuracy can be manufactured.

  Since the elastic roller according to the present invention is manufactured by the method for manufacturing an elastic roller according to the present invention, the elastic roller has an elastic layer with high deflection accuracy.

  Therefore, according to the present invention, a method for polishing a tubular elastic body capable of polishing the tubular elastic body so as to have high runout accuracy, a method for producing an elastic roller capable of producing an elastic roller having an elastic layer with high runout accuracy, and runout Each elastic roller having an elastic layer with high accuracy can be provided.

FIG. 1 is an enlarged cross-sectional view of an essential part showing an example of a collet chuck suitably used in a method for polishing a tubular elastic body according to the present invention and a method for manufacturing an elastic roller according to the present invention. FIG. 2 is an enlarged cross-sectional view showing a main part of an example of a collet chuck suitably used in the method for polishing a tubular elastic body according to the present invention and the method for manufacturing an elastic roller according to the present invention. . FIG. 3 is a schematic explanatory view showing a state in which the roller base is gripped by a polishing apparatus suitably used in the method for polishing a tubular elastic body according to the present invention and the method for manufacturing an elastic roller according to the present invention. FIG. 4 is a schematic cross-sectional view showing an example of an elastic roller manufactured by the elastic roller manufacturing method according to the present invention. FIG. 5 is an enlarged sectional view of a main part showing a conventional collet chuck. FIG. 6 is an enlarged cross-sectional view of a main part showing a state in which a shaft body is gripped by a conventional collet chuck.

  The elastic roller according to the present invention will be described. The roller according to the present invention is manufactured by the elastic roller manufacturing method according to the present invention, which has the tubular elastic body polishing method according to the present invention as an essential step. The elastic roller according to the present invention may be a roller in which an elastic layer is disposed on the outer peripheral surface of the shaft body, and may include, for example, an adhesive layer, a primer layer, a surface layer, or the like in addition to the shaft body and the elastic layer. .

  The elastic roller according to the present invention has high deflection accuracy, for example, 0.10 mm or less, preferably 0.03 mm or less. The lower limit of the shake accuracy is ideally zero, but is practically 0.02 mm. Here, the runout accuracy is an accuracy indicating the concentricity between the shaft body and the elastic layer, in other words, an accuracy indicating the thickness uniformity in the circumferential direction of the elastic layer, that is, the thickness runout. The elastic roller is shaken using a laser length measuring device, for example, a product name “Laser Scan Micrometer” (Lsm-600 manufactured by MITUTOYO) while rotating the elastic roller around the central axis of the shaft body at a rotation speed of 30 rpm. It can be calculated by measuring the outer diameter of the elastic roller.

  An example of the elastic roller according to the present invention will be described with reference to the drawings. As shown in FIG. 4, the elastic roller 70 as an example includes a shaft body 71 and an elastic layer 72.

  As shown in FIG. 4, the shaft body 71 is basically the same as the shaft body in a conventionally known elastic roller. The shaft 71 has a cylindrical outer peripheral surface 71c and a chamfered portion 71a that are gripped by a collet chuck described later. Specifically, the shaft body 71 is a rod-like body extending in one direction, and is in the axial direction arranged on both end sides of the tubular elastic body 7, that is, the elastic layer forming region where the elastic layer 72 is formed. It has a cylindrical outer peripheral surface 71c having a uniform outer diameter, and chamfered portions 71a arranged at both ends. This elastic layer forming region has a uniform outer diameter in the axial direction.

  The chamfered portion 71a is usually an annular tapered surface 71b that is flat toward each end of the shaft body 71 and gradually decreases in outer diameter, that is, a C surface or an annular curved surface, that is, an R surface. Is an annular tapered surface 71b. The annular tapered surface 71b can also be called a frustum-shaped outer peripheral surface. The chamfer 71a is formed by chamfering such as C chamfering or R chamfering (round chamfering). In the chamfered portion 71a, an inclination angle (also referred to as a chamfered angle) of the chamfered portion 71a with respect to a plane perpendicular to the axis of the shaft body 71 is in the range of more than 0 ° and not more than 90 °, preferably 15 to 75 °. Is in range. The length of the chamfered portion 71a in the axial direction can be set to, for example, 0.5 to 2 mm (in the case of a C chamfered portion, “C0.5 to 2”).

  The cylindrical outer peripheral surface 71c is an outer peripheral surface of each end portion of the shaft body 71 projecting from each end surface of an elastic layer 72 as a tubular elastic body described later, and the shaft body 71 is a chamfered portion 71a. In the case of having the chamfered portion 71a, the region does not include the chamfered portion 71a and exists between the elastic layer forming region and the chamfered portion 71a. The cylindrical outer peripheral surface 71c has the same outer diameter as the continuous elastic layer forming region and an axial length equal to or greater than the axial length of the gripping surface 19 in the collet chuck described later.

  The shaft body 71 should be free from protrusions such as burrs and scratches generated during chamfering on a cylindrical outer peripheral surface 71c held by a collet chuck, which will be described later, and in this invention, a region that is not held by the collet chuck, For example, the elastic layer 72 having high deflection accuracy with respect to the shaft body 71 can be formed even if protrusions such as burrs, scratches, and the like exist in the chamfered portion 71a and the vicinity thereof. The dimensional tolerance of the shaft 71 is usually 0.03 mm or less.

  The shaft body 71 is a shaft body called a “core metal” made of iron, aluminum, stainless steel, brass, or the like, and has good conductive characteristics. The shaft body 71 may be a shaft body that is made conductive by plating an insulating core body such as a thermoplastic resin or a thermosetting resin.

  In this invention, the shaft body may be a shaft body having chamfered portions at both ends thereof as shown in FIG. 4, and the chamfered portions are provided at both end portions with the inclination angle of 0 °. It may be a shaft body having a uniform outer diameter in the axial direction not having, or a shaft body having a journal portion having a diameter smaller than that of the elastic layer forming region in which the elastic layer is formed at least at one end. Alternatively, it may be a shaft body having an outer diameter that gradually increases or decreases so that at least the elastic layer forming region has a so-called “crown shape” or a so-called “reverse crown shape”.

  The elastic layer 72 is basically the same as the elastic layer in a conventionally known elastic roller except that the deflection accuracy with respect to the shaft 71 is high. The elastic layer 72 is an elastic layer formed by curing a rubber composition described later on the outer peripheral surface of the shaft body 71. The elastic layer 72 may be a “foamed elastic layer” formed of a sponge body or a solid so-called “solid elastic layer” depending on applications and the like, and may have an appropriate hardness, electrical resistance and thickness. It is adjusted to the same. The thickness of the elastic layer 72 is usually preferably 1 to 30 mm, and more preferably 5 to 20 mm.

  The form of the elastic layer 72 is not particularly limited, and may be, for example, a so-called “straight shape” adjusted to have a uniform outer diameter over the axial direction as shown in FIG. The so-called “crown shape” adjusted to be larger than the outer diameter may be used, and the so-called “reverse crown shape” adjusted so that the outer diameter at the center portion is smaller than the outer diameter at both ends thereof. It may be.

  The elastic roller according to the present invention has high shake accuracy, and thus can be suitably used as any elastic roller mounted on an image forming apparatus or the like. However, the quality of the image formed by the image forming apparatus is particularly large. It is suitably used as a developing roller, a developer supply roller, a fixing roller, a pressure roller, a transfer roller, a cleaning roller, etc. that have an influence.

  A polishing apparatus and a collet chuck suitably used in the method for polishing a tubular elastic body according to the present invention and the method for manufacturing an elastic roller according to the present invention will be described. As shown in FIG. 3, the polishing apparatus 1 includes a headstock (not shown), a pair of collet chucks 3 disposed on the headstock so as to face each other, and a collet. A driving unit 2 that rotationally drives one of the chucks 3 and a grindstone 4 that is disposed so as to be able to move back and forth in parallel with the roller base 6 held by the collet chuck 3 and polish the roller base 6 are provided. . The driving means 2 is not particularly limited as long as the collet chuck 3 can be rotationally driven, and examples thereof include various motors.

  The grinding wheel 4 has a grinding wheel width that is longer than the tubular elastic body 7 of the roller base 6 to be polished, and the polishing apparatus 1 is a so-called “plunge type polishing apparatus”. In this so-called “plunge type polishing apparatus”, the load applied to the shaft 71 during polishing is relatively large, and the swing accuracy may be lowered. However, the tubular elastic body polishing method according to the present invention and the elastic roller manufacturing method according to the present invention, which grips a particularly narrow range of the shaft body 71, are different from the conventional holding method for holding the entire end of the shaft body. According to this, since the interference between the shaft body 71 and the collet chuck 3 can be reduced, it is possible to prevent a decrease in runout accuracy.

  The grindstone 4 only needs to be able to polish the tubular elastic body 7. For example, the grindstone 4 may be a grindstone without abrasive grains or a grindstone formed by bonding abrasive grains with a binder or the like. The grindstone 4 and the abrasive grains are arbitrarily adjusted in particle size, material, hardness, shape and the like according to the dimensional accuracy and surface accuracy required for the polishing of the tubular elastic body 7. For example, the materials of the grindstone 4 and the abrasive grains include silicon carbide (carbon random), diamond, diamond-like carbon, alumina, nylon, cubic boron nitride (CBN), and the like. The particle size of the grindstone 4 or the abrasive grains is, for example, preferably about 10 to 80 μm, more preferably about 20 to 70 μm, and particularly preferably about 30 to 45 μm. Examples of the shape of the abrasive grains include a spherical shape, an indefinite shape, a flat shape, a dish shape, and the like, and a spherical shape is preferable. Such a grindstone 4 or abrasive grains can be appropriately prepared, and a commercially available product can also be used. For example, the grindstone or the abrasive grain specified in JIS R 6215 (1999) “rubber cutting grindstone” and JIS R 6001 (1998) “grain size of abrasive for grinding grindstone” can be arbitrarily selected and used. More specifically, for example, “GC fine grinding fine powder” (for example, manufactured by Mabuchi S & T Co., Ltd.) can be mentioned.

  As shown in FIG. 3, the collet chuck 3 is disposed so as to be opposed to each other on a head stock (not shown) of the polishing apparatus 1, and the gripping portion 18 (see FIGS. 1 and 2) is different. Is basically the same as a conventionally known collet chuck. As shown in FIG. 3, one of the collet chucks 3 is connected to the driving means 2 and is pivotally supported so as to be rotationally driven, and the other is pivotally supported so as to be driven to rotate on the headstock. As shown in FIGS. 1 and 2, the set of collet chucks 3 is configured so that a gripping surface 19 of a collet claw 15 to be described later grips a region within 10 mm from the end surface of a cylindrical outer peripheral surface 71 c of a shaft body 71. Are arranged so as to share an axis with an interval.

  As shown in FIGS. 1 and 2, the collet chuck 3 has a cylindrical main body 11 with an open free end, and the main body 11 is relatively movable in the axial direction with respect to the main body 11. The collet 12 is disposed, and a central shaft 13 disposed in the collet 12 so as to be movable in the axial direction relative to the collet 12. The main body 11 and the middle shaft 13 are basically the same as the main body and the middle shaft in a conventionally known collet chuck. For example, the main body 11 is disposed so as to be able to move back and forth in the axial direction thereof, and has an annular inner surface 14 whose inner diameter gradually increases toward the opening on the inner surface of the opening. The annular inner surface 14 is brought into pressure contact with an annular outer surface 17 (to be described later) of the collet 12 by the advancement of the main body 11 to reduce the diameter of the gripping hole 16. The middle shaft 13 is disposed in the gripping hole 16 of the collet 12, contacts the end surface of the shaft body 71 inserted into the gripping hole 16, positions the shaft body 71, and assists the gripping of the shaft body 71. The middle shaft 13 is urged toward the opening of the main body 11 by an elastic body (not shown) such as a coil spring, and can be pushed from the opening to the inside against the urging force.

  The collet 12 is basically the same as a conventionally known collet chuck except that the holding portion 18, that is, the portion that holds the shaft body 71 is adjusted, and is connected to each other at a base portion (not shown). A plurality of, for example, four collet claws 15 formed in an arc shape with a central angle of less than 90 ° are provided, and a gripping hole 16 for gripping the shaft body 71 by these collet claws 15 is formed as an axial hole on the axis. Each of the collet claws 15 is formed such that an annular outer surface 17 whose free end, that is, an outer peripheral surface on the opening side of the main body 11 gradually increases, contacts the annular inner surface 14. As shown in FIGS. 1 and 2, each collet claw 15 has a grip portion 18 having a small inner diameter for gripping the cylindrical outer peripheral surface 71c of the shaft body 71 on the free end side, that is, on the inner peripheral surface on the free end side. It has a gripping portion 18 protruding in the axial direction. The inner diameter of the base side of the grip part 18 of the collet claw 15 is larger than that of the grip part 18. The gripping portion 18 has a gripping surface 19 having an arcuate shape in an axial view so that the cylindrical outer peripheral surface 71c can be gripped uniformly from the outer peripheral surface. The axial length of the gripping surface 19 is set to be 8 to 21% of the axial length of the shaft 71 protruding from the end surface of the tubular elastic body 7 of the roller base body 6 to be gripped. Yes.

  The polishing apparatus 1 and the collet chuck 3 that are preferably used in the method for polishing a tubular elastic body according to the present invention and the method for manufacturing an elastic roller according to the present invention have been described. The method for polishing a tubular elastic body according to the present invention and this The polishing apparatus and the collet chuck used in the method for manufacturing the elastic roller according to the invention are not limited to the polishing apparatus 1 and the collet chuck 3 as long as they can hold a specific cylindrical outer peripheral surface of the shaft body. A collet chuck can be used.

  The method for polishing a tubular elastic body according to the present invention is within 8 to 21% of the axial length of the shaft body which is within 10 mm from the end surface of at least one end of the shaft body and protrudes from the end surface of the tubular elastic body. A step of gripping the cylindrical outer peripheral surface of the axial length with a collet chuck, a step of relatively rotating the tubular elastic body, and a step of polishing the outer peripheral surface of the tubular elastic body with a grindstone without adjusting the peripheral environment of the collet chuck have. Further, the elastic roller manufacturing method according to the present invention includes a step of producing a roller base body by arranging a tubular tubular body on the outer peripheral surface of the shaft body, and a tubular elastic body polishing method according to the present invention. And a step of polishing.

  An example of manufacturing the elastic roller 70 shown in FIG. 4 using the polishing apparatus 1 shown in FIGS. 1 to 3 together with the method for manufacturing an elastic roller according to the present invention (hereinafter referred to as the elastic roller 70) shown in FIG. This will be specifically described with reference to a manufacturing method. The elastic roller 70 is as described above.

  In this one manufacturing method, first, the shaft body 71 is prepared. The shaft 71 is made of, for example, a metal such as iron, aluminum, stainless steel, brass, or an alloy thereof, a resin such as a thermoplastic resin or a thermosetting resin, and carbon black or metal powder as a conductivity-imparting agent for the resin. It is prepared in a desired shape by a known method using a material such as a conductive resin blended with a body. This shaft body 71 has C-chamfered at both ends of a rod-like body extending in one direction, at least an elastic layer forming region where an elastic layer 72 described later is formed and a cylindrical outer peripheral surface 71c having a uniform outer diameter in the axial direction. The chamfered portion 71a is formed by processing and is manufactured. At this time, protrusions such as burrs during C chamfering may not be removed in the vicinity of the chamfered portion 71a. The shaft body 71 thus produced may be coated with a conventionally known primer on the outer peripheral surface in order to form a primer layer having a thickness of, for example, 0.1 to 10 μm, if desired.

  In this manufacturing method, next, a rubber composition described later is cured on the outer peripheral surface of the shaft body 71 to produce a roller base body 6 having a tubular elastic body 7 disposed on the outer peripheral surface of the shaft body 71. To implement. Such a roller base 6 can be produced by a known method. For example, first, a rubber composition is disposed on the outer peripheral surface of the shaft body 71. The method is appropriately selected depending on the rubber composition. For example, a method of dispensing the shaft body 71 and the rubber composition integrally with an extruder or the like, or a rubber composition in a mold for housing the shaft body 71 The method of injecting a thing etc. are mentioned. Among these, the method of dispensing the shaft body 71 and the rubber composition integrally with an extruder or the like is preferable because the work is easy and the work can be performed continuously. Thus, after arrange | positioning a rubber composition to the outer peripheral surface of the shaft 71, a rubber composition is heated with the shaft 71 while maintaining this state. The heating of the rubber composition is usually performed under conditions sufficient for the rubber or resin contained in the rubber composition to be crosslinked by a heating furnace such as an infrared heating furnace or a hot air furnace, a heating machine such as a dryer, and the like. Good. Thus, the roller base body 6 having the tubular elastic body 7 disposed on the outer peripheral surface of the shaft body 71 is produced.

  In this manufacturing method, the cylindrical outer peripheral surface 71c of each end portion of the shaft body 71 in the manufactured roller original body 6 is then within 10 mm from the end surface and protrudes from the end surface of the tubular elastic body 7. The step of gripping with the collet chuck 3 is performed so that the axial length is 8 to 21% with respect to the axial length. Specifically, as shown in FIGS. 2 and 3, both end portions of the shaft body 71 are inserted into the holding holes 16 of the collet chuck 3, and the main body 11 is moved to the opening side. Then, as shown in FIG. 2, the annular outer surface 17 of the collet claw 15 is pressed by the annular inner surface 14 of the main body 11, and the gripping hole 16 into which the shaft body 71 is inserted is reduced in diameter. The surface 19 is in pressure contact with each of the cylindrical outer peripheral surfaces 71c of the shaft body 71 toward the axis. At this time, as shown in FIG. 2, the shaft body 71 is positioned in the axial direction with both ends of the shaft body 71 abutting against the middle shaft 13, and the gripping state by the collet chuck 3 is assisted. When the both ends of the shaft body 71 are gripped by the collet chuck 3 in this way, the polishing apparatus 1, particularly the collet chuck 3, is configured as described above. At each end of the cylindrical outer peripheral surface 71c protruding from the axial length of 8 to 21% with respect to the axial length of the shaft body 71 which is a region within 10 mm from the end surface and protrudes from the end surface of the tubular elastic body 7 Is held by the holding surface 19 of the collet claw 15 and held by the polishing apparatus 1.

  As described above, when the collet chuck 3 grips the cylindrical outer peripheral surface 71c within a region of 10 mm from the end surface of the shaft body 71 as a gripping position, the problem that “runout accuracy decreases” ”Can be avoided, and it is critical to make the gripping position“ within 10 mm ”. In order not to cause this problem effectively, the area gripped by the collet chuck 3 is preferably within 5 mm from the end surface of the shaft body 71. The minimum distance from the end face of the region gripped by the collet chuck 3 is not particularly limited as long as it can be gripped by the collet chuck 3, but is actually about 1 mm, and the shaft body 71 has a chamfered portion 71a. In this case, it is closer to the tubular elastic body 7 than the chamfered portion 71a.

  Further, when the collet chuck 3 grips a region having an axial length of less than 8% with respect to the axial length of the shaft 71 projecting from the end surface of the tubular elastic body 7 of the roller base 6 on the cylindrical outer peripheral surface 71c. There may be a problem that the idling or runout accuracy of the shaft body 71 is lowered during polishing. On the other hand, if the collet chuck 3 grips a region having an axial length exceeding 21% with respect to the axial length, the runout accuracy is improved. There may be a problem of degradation. Thus, contrary to the conventional technical common sense that it is desirable to increase the gripping amount in order to improve the deflection accuracy, the gripping amount reduced from this technical common sense, that is, the axial length is 8 to 21%. The above problems can be avoided, and the gripping amount has a critical significance. The region gripped by the collet chuck 3 in terms of not causing these problems effectively is a region of 8.5 to 12.5% with respect to the axial length of the shaft body 71 protruding from the end face of the tubular elastic body 7. Preferably there is. In this invention, the grip width of the cylindrical outer peripheral surface 71c may be in the above range, but specifically, the grip width of the cylindrical outer peripheral surface 71c is preferably 1 to 5 mm, and is preferably 2 to 3 mm. Is particularly preferred.

  When the cylindrical outer peripheral surface 71c of the shaft body 71 is gripped by the collet chuck 3 in this manner, the shaft body 71 is slightly decentered, the shaft body 71 is uneven in dimension, and the chamfered portion 71a is not burred. Even when there are protrusions such as the shaft body 71 and the both ends of the shaft body 71 are gripped by the collet chuck 3, the shaft body 71 is substantially the same as the shape and axis of the shaft body 71 that is not gripped. In this state, it is held by the polishing apparatus 1, that is, the collet chuck 3.

  In this manufacturing method, the step of rotating the tubular elastic body 7, that is, the roller base body 6, is then performed. This rotating step is performed by driving the driving means 2 to rotate the collet chuck 3 that holds the shaft 71. At this time, the rotational speed at the time of polishing the tubular elastic body 7 may be appropriately set according to the tubular elastic body 7 to be polished, the polishing amount, and the like, and is set to 70 to 400 rpm, for example. In this manufacturing method, the tubular elastic body is rotated as the step of rotating the tubular elastic body, but the tubular elastic body may be fixed and the grindstone may be rotated, and both the tubular elastic body and the grindstone are rotated. Also good.

  In this manufacturing method, the step of polishing the outer peripheral surface of the tubular elastic body 7 with the grindstone 4 is then performed without adjusting the surrounding environment of the collet chuck 3. This polishing step is performed during the rotating step without adjusting the surrounding environment of the collet chuck 3 during polishing, that is, in the surrounding environment where the polishing apparatus 1 is disposed, for example, in the normal pressure environment. . In other words, it is carried out in a state where the collet claw 15 is exposed to the atmosphere without positive pressure, that is, pressurization around the collet chuck 3. “Polishing” in the polishing step is a concept including surface treatment steps such as “grinding” and “cutting”.

  In the polishing step, the grindstone 4 is moved relatively toward the roller base 6 so as to be substantially parallel to be pressed against the tubular elastic body 7. At this time, the press-contact pressure of the grindstone 4 to the tubular elastic body 7 is appropriately set according to the tubular elastic body 7 to be polished, the polishing amount, and the like. In this step, the grindstone 4 may be stationary or may itself be rotated. When the grindstone 4 is rotated, the rotational speed of the grindstone 4 may be appropriately set according to the tubular elastic body 7 to be polished, the polishing amount, and the like. For example, the rotational speed of the grindstone 4 is set to 1500 to 4500 rpm. The direction may be the same as the direction of rotation of the tubular elastic body 7 or the reverse direction, and the reverse direction is preferable in terms of excellent polishing efficiency.

  In this way, an example of the method for polishing a tubular elastic body according to the present invention, in which the tubular elastic body 7 is polished all at once in the axial direction, is implemented, and the elastic roller 70 is manufactured. One manufacturing method which is an example of a method is implemented.

  In this manufacturing method, when the polishing step is performed as described above, the shape and axis of the shaft body 71 that is not gripped regardless of the size and shape accuracy of the shaft body 71 and the number of grips in the gripping step. Since the shaft body 71 is gripped by the polishing apparatus 1, that is, the collet chuck 3 in a state that substantially coincides with the cylindrical elastic body, a tubular elastic body is provided so that the deflection accuracy when the shaft body 71 is removed from the polishing apparatus 1, that is, the collet chuck 3 is increased. 7 can be polished. Therefore, according to the method for polishing a tubular elastic body according to the present invention, the tubular elastic body can be polished so as to have high runout accuracy, and an elastic layer having high runout accuracy with respect to the shaft body 71 can be formed. In addition, according to the elastic roller manufacturing method of the present invention, the elastic roller 70 having the elastic layer 72 with high deflection accuracy with respect to the shaft body 71 can be manufactured. Moreover, in the method for polishing a tubular elastic body according to the present invention and the method for manufacturing an elastic roller according to the present invention, it is not necessary to adjust the surrounding environment of the polishing apparatus 1, that is, the collet chuck 3. Although it can be implemented well, it can realize a high runout accuracy equal to or higher than that of a conventional polishing method, for example, “rubber roller grinding method” described in Patent Document 1.

  The method for polishing a tubular elastic body according to the present invention and the method for manufacturing the elastic roller according to the present invention are not limited to the above-described embodiments, and various modifications are possible within the scope that the object of the present invention can be achieved. Is possible. For example, in the manufacturing method, both end portions of the shaft body 5 are gripped by the collet chuck 3, but in this invention, the shaft body has the gripping amount as described above at least one of the both end portions by the collet chuck. For example, one end portion of the shaft body is gripped by the collet chuck as described above, and the other end portion, particularly the end surface thereof, has a conical recess having a gradually decreasing inner diameter, for example. You may press and hold on a stand.

  In the manufacturing method described above, the tubular elastic body 7 of the roller base 6 is polished at once using a “plunge type polishing apparatus”. In the present invention, the roller base whose axial length is to be polished is used. Using a so-called “traverse polishing device” equipped with a grindstone shorter than the tubular elastic body, the grindstone is pressed against the tubular elastic body of the roller base and moved in the axial direction to polish the tubular elastic body. Good. At this time, the grindstone may be moved one way in the axial direction, may be reciprocated once, or may be reciprocated a plurality of times.

  In the one manufacturing method, the shaft body 71 having the chamfered portions 71a at both ends is used. However, in the present invention, a shaft body without a chamfered portion can also be used.

  The one manufacturing method includes a step of polishing the tubular elastic body 7. In the present invention, in addition to the polishing step, the resin composition is cured on the outer peripheral surface of the elastic layer as desired. You may have the process of forming a coat layer. This step is carried out, for example, by applying a resin composition to the surface of the elastic layer according to a conventional method and heat curing.

  In the manufacturing method, the shaft 71 is gripped by the collet chuck 3 and polished. In this invention, the shaft is gripped by the collet chuck and the peripheral pressure of the collet chuck changes greatly. Polishing may be performed while flowing air in the axial direction from the base side of the collet chuck to such an extent that it does not occur. When polishing is performed while air is circulated in this manner, it is possible to prevent the polishing residue and the like from entering the collet chuck. Such a mechanism for circulating air can be configured in the same manner as a conventionally known polishing apparatus.

  The elastic roller according to the present invention is not limited to the above-described embodiments, and various modifications can be made within a range in which the object of the present invention can be achieved. For example, the elastic roller 70 includes a shaft body 71 having a chamfered portion 71a and an elastic layer 72. However, in the present invention, the elastic roller may include a shaft body having no chamfered portion and elastic. You may provide the coating layer arrange | positioned at the outer peripheral surface of a layer.

Example 1
Both ends of a rod-shaped body made of SUM22 steel having a diameter of 5.95 mm and a length of 281.5 mm are chamfered to form a chamfered portion 71 a having an axial length of 1 mm (C1) and an inclination angle of 45 °. . The outer peripheral surface of this rod-shaped body was subjected to electroless nickel plating, washed with toluene, and a silicone primer (trade name “Primer No. 16”, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to the surface. The primer-treated rod-shaped body was baked at a temperature of 150 ° C. for 10 minutes using a gear oven, and then cooled at room temperature for 30 minutes or more. In this way, a shaft 71 having a primer layer on the surface was produced.

  On the other hand, 100 parts by weight of methyl vinyl silicone raw rubber (trade name “KE-78VBS”, manufactured by Shin-Etsu Chemical Co., Ltd.) and 20 parts by weight of dimethyl silicone raw rubber (trade name “KE-76VBS”, manufactured by Shin-Etsu Chemical Co., Ltd.) , 10 parts by mass of carbon black (trade name “Asahi Thermal”, manufactured by Asahi Carbon Co., Ltd.), 15 parts by mass of fumed silica-based filler (trade name “AEROSIL 20”, manufactured by Nippon Aerosil Co., Ltd.), platinum catalyst ( 0.5 parts by mass of product name “C-19A”, manufactured by Shin-Etsu Chemical Co., Ltd., and 2.0 parts by mass of hydrogen polysiloxane (trade name “C-19B”, manufactured by Shin-Etsu Chemical Co., Ltd.) Then, the mixture was kneaded with a pressure kneader to prepare an addition-curable millable conductive silicone rubber composition.

  Next, the shaft body 71 and the addition-curable millable conductive silicone rubber composition were integrated and dispensed using a crosshead with an extruder, and heated in a gear oven at 300 ° C. for 15 minutes. Next, in this state, it was heated in a gear oven at 200 ° C. for 4 hours to be secondarily cured, and the tubular elastic body 7 having an outer diameter of 23 mm and an axial length of 234.5 mm was formed on the outer peripheral surface of the shaft 71. A roller base 6 having the above was produced. The axial length of the shaft body 71 protruding from each end face of the tubular elastic body 7 in this roller original body 6 was 23.5 mm.

  A polishing apparatus 1 was prepared in which a set of collet chucks 3 each having a collet 12 composed of four collet claws 15 each having a gripping surface 19 having an axis length of 2 mm was disposed on a headstock. This polishing apparatus 1 has a cylindrical grindstone 4 having an outer diameter of 305 mm and an axial length of 250 mm (trade name “GC220HRV”, manufactured by Mitsui Whetstone Co., Ltd., material is silicon carbide, binder is resinoid, abrasive grains The shape was spherical.

  Next, the collet chuck 3 of the polishing apparatus 1 prepared is within 10 mm from the end surface and has an axial length of 2.0 mm (8. 8 with respect to the axial length of the shaft body 71 protruding from the end surface of the tubular elastic body 7. 5%) cylindrical outer peripheral surface 71c was gripped, and then the driving means 2 was driven to rotate the roller base 6 at 130 rpm around its axis. In this state, without adjusting the surrounding environment of the collet chuck 3, the grindstone 4 is pressed at the entire axial direction of the tubular elastic body 7 while rotating the grindstone 4 at 2800 rpm in the opposite direction to the roller original body 6 at atmospheric pressure. The outer peripheral surface of 7 was polished. The amount of polishing of the tubular elastic body 7 at this time was 0.25 mm in the thickness direction. In this way, an elastic roller was manufactured.

(Example 2)
An elastic roller was manufactured basically in the same manner as in Example 1 except that the axial length of the gripping surface 19 in the collet claw 15 was changed to 4.5 mm (19% with respect to the axial length).

(Example 3)
Instead of one of the collet chucks 3 of the polishing apparatus 1 being a 12 mm outer diameter core pusher having a conical recess (depth 10 mm) with a gradually decreasing inner diameter, one end of the shaft 71 is connected to the collet chuck 3. In the same manner as in Example 1 except that the grip was held at 2.0 mm (8.5% with respect to the axial length) as described above, and the other end was pressed against and held by the press stand. An elastic roller was manufactured.

(Comparative Example 1)
Each of the two collet chucks 3 of the polishing apparatus 1 is changed to a collet chuck 50 shown in FIG. 5, and the entire area from each end face of the shaft body 71 to 5.5 mm as shown in FIG. An elastic roller was manufactured in basically the same manner as in Example 1 except that (23.4% with respect to the axial length) was gripped. As shown in FIG. 6, the collet chuck 50 has an axial length that allows the gripping surface 53 of the gripping portion 52 of the collet claw 51 to grip the entire region from the end surface of the shaft body 71 to 15 mm. Is basically the same as the collet chuck 3, and the same members as those of the collet chuck 3 are denoted by the same reference numerals.

  The runout accuracy of each elastic roller manufactured in this way was measured as described above. The results are shown in Table 1.

DESCRIPTION OF SYMBOLS 1 Polishing device 2 Driving means 3, 50 Collet chuck 4 Grinding stone 6 Roller base 7 Tubular elastic body 11 Main body 12 Collet 13 Center shaft 14 Annular inner surface 15, 51 Collet claw 16 Grasping hole 17 Annular outer surface 18, 52 Grasping parts 19, 53 Surface 70 Elastic roller 71 Shaft 71a Chamfer 71b Annular taper surface 71c Cylindrical outer peripheral surface 72 Elastic layer

Claims (6)

A method for polishing a tubular elastic body for polishing an outer peripheral surface of a tubular elastic body disposed on an outer peripheral surface of a shaft body,
A cylindrical outer peripheral surface having an axial length of 8 to 21% with respect to the axial length of the shaft within 10 mm from the end surface of at least one end of the shaft and protruding from the end surface of the tubular elastic body. Gripping with a collet chuck;
Relatively rotating the tubular elastic body;
Polishing the outer peripheral surface of the tubular elastic body with a grindstone without adjusting the surrounding environment of the collet chuck.   The tubular elastic body polishing method according to claim 1, wherein the shaft body has chamfered portions chamfered at both ends.   The tubular elastic body polishing method according to claim 1 or 2, wherein the gripping step grips both end portions of the shaft body with the collet chuck.   The tubular elasticity according to claim 1 or 2, wherein the gripping step grips one end portion of the shaft body with the collet chuck and presses and holds the other end portion of the shaft body against a core push stand. Body polishing method. An elastic roller manufacturing method for manufacturing an elastic roller having an elastic layer disposed on an outer peripheral surface of a shaft body,
A step of arranging a tubular elastic body on the outer peripheral surface of the shaft body to produce a roller base body;
A method of manufacturing an elastic roller, comprising: polishing the tubular elastic body with the tubular elastic body polishing method according to any one of claims 1 to 4.   An elastic roller manufactured by the method for manufacturing an elastic roller according to claim 5 and having a circumferential runout accuracy of 0.10 mm or less.

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