JP2017056600A - Manufacturing method of roll and manufacturing method of charging roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an increase in an outer diameter of a rubber material at a tip end part of a core grid when an extrusion speed of the core grid is controlled compared to a structure in which the feeding speed of the tip end part of the core grid is not increased from the controlled speed in a method for manufacturing a plurality of rolls by feeding the plurality of core grids to the rubber material at intervals while extruding the rubber material.SOLUTION: A plurality of core grids 22 are fed sequentially at a controlled speed at intervals in a center part C of a rubber material G extruded in a cylindrical shape. A rubber roll part 56 where an outer periphery surface of the core grid 22 is covered by the rubber material G and a hollow part 58 where the core grid 22 does not exist in the center part C of the rubber material G between the former core grid 22 and the rear core grid 22 are discharged alternately. Note here that the feeding speed of the core grid 22 when feeding a tip part of the core grid 22 in an axial direction to the center part C is increased to a level higher than the controlled speed such that a ratio of an outer diameter of the rubber material G in the tip end part of the core grid 22 in the axial direction to the outer diameter of the rubber material G in a rear end part falls within a range of 100%, inclusive, to 200%, exclusive.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a roll manufacturing method and a charging roll manufacturing method.

  The roll manufacturing method of Patent Document 1 is a method in which the outer shape is crowned using a crosshead extrusion device, and the moving speed of the cored bar in the die nozzle is gradually decreased and then gradually increased. The diameter is changed in the length direction.

Japanese Patent Laid-Open No. 2003-300279

  In a method of manufacturing a plurality of rolls by feeding a plurality of core bars into the rubber material at intervals while extruding the rubber material, in a configuration in which the moving speed of the core metal is gradually reduced by controlling the quadratic curve, at a constant speed The extruded rubber material may accumulate at the tip of the cored bar. Accordingly, there is a possibility that the outer diameter of the rubber material is increased from the determined outer diameter at the tip of the core metal of the roll.

  The present invention relates to a method for producing a plurality of rolls by feeding a plurality of metal cores at intervals while extruding a rubber material, and increasing the feeding speed of the tip of the metal core from the speed by the quadratic curve control. An object of the present invention is to suppress an increase in the outer diameter of the rubber material at the tip of the core metal when the extrusion speed of the core metal is controlled by a quadratic curve, as compared with a configuration that does not speed.

  In the roll manufacturing method according to claim 1 of the present invention, a plurality of core bars are sequentially fed at a speed controlled by a quadratic curve at intervals in the center of a rubber material extruded in a cylindrical shape. Manufacture of a roll that alternately discharges a rubber roll portion that is coated on the outer peripheral surface of the core metal and an intermediate portion that does not have a core metal in the center of the rubber material between a front core metal and a rear core metal It is a method, Comprising: The said metal core so that ratio of the outer diameter of the said rubber material in the axial direction front-end | tip part of the said metal core and the outer diameter of the said rubber material in a rear-end part may be 100% or more and less than 200%. The feeding speed of the cored bar when feeding the axial tip of the core to the center is increased from the speed by the quadratic curve control.

  In the roll manufacturing method according to claim 2 of the present invention, the axial total length of the cored bar is 100%, and the end position that is the position from the tip of the cored bar and ends the acceleration is 1.4% or more. Within the range of 5% or less.

  In the roll manufacturing method according to claim 3 of the present invention, the feeding speed of the cored bar is increased with the lowest feeding speed among the feeding speeds of the cored bar controlled by the quadratic curve as a reference speed. When the speed is increased, the ratio of the feeding speed to the reference speed is set to 120% to 300%.

  The charging roll manufacturing method according to claim 4 of the present invention is the roll manufacturing method according to any one of claims 1 to 3, wherein the core metal is an elastic layer made of the conductive rubber material. Form.

  The invention according to claim 1 is a method of manufacturing a plurality of rolls by feeding a plurality of metal cores into a rubber material at intervals while extruding a rubber material. Compared to a configuration in which the speed is not increased from the speed, it is possible to suppress an increase in the outer diameter of the rubber material at the tip of the core metal when the extrusion speed of the core metal is controlled by a quadratic curve.

  In the invention of claim 2, the tip end portion of the metal core is compared with the configuration in which the feed speed of the metal core is increased in a range where the end position of the acceleration is smaller than 1.4% or larger than 8.5%. Thus, the increase in the outer diameter of the rubber material can be suppressed.

  In the invention of claim 3, the outer diameter of the rubber material is increased or excessively decreased at the tip end portion of the metal core as compared with the configuration in which the ratio of the feeding speed to the reference speed is smaller than 120% or larger than 300%. Can be suppressed.

  The invention of claim 4 can suppress an increase in the outer diameter of the elastic layer at the tip of the cored bar as compared with a configuration in which the feeding speed of the cored bar is not increased from the speed by the quadratic curve control. .

It is sectional drawing which shows the structure of the roll manufacturing apparatus which concerns on this embodiment. It is a block diagram of the control part concerning this embodiment. (A) It is a schematic diagram of the metal core which concerns on this embodiment. (B) It is sectional drawing of the rubber roll part which concerns on this embodiment. (C) It is a schematic diagram of the charging roll which concerns on this embodiment. It is a graph which shows the change with respect to the position of the axial direction of the feeding speed of the metal core which concerns on this embodiment. (A), (B), (C) It is sectional drawing which shows the state from which the metal core which concerns on this embodiment is sent into a rubber material, and is taken out. (A), (B) It is sectional drawing which shows the state from which the rubber roll part which concerns on this embodiment is taken out by the extraction part. (A), (B), (C) It is sectional drawing which shows the state which presses the hollow part which concerns on this embodiment with a pressing member. (A) It is a table | surface which shows the measurement result of the position from the front-end | tip, the speed ratio, and the outer diameter ratio in Example 1 to Example 9 of this embodiment. (B) It is a table | surface which shows the measurement result of the position from the front-end | tip, the speed ratio, and the outer diameter ratio in the comparative example 1 to the comparative example 4 of this embodiment. (A) It is explanatory drawing which compared the feeding speed line of the metal core of this embodiment, and the feeding speed line by quadratic curve control. (B) It is explanatory drawing which compared the feeding speed line of the metal core in the modification of this embodiment, and the feeding speed line by quadratic curve control.

  An example of a roll manufacturing method and a charging roll manufacturing method according to the present embodiment will be described. The rubber-coated shaft body manufactured by the roll manufacturing method and the charging roll manufacturing method according to the present embodiment is used as the charging roll 70 (see FIG. 3C) as an example.

  A charging roll 70 shown in FIG. 3C is an example of a roll, and rotates in contact with a photoreceptor (not shown) of the image forming apparatus to charge the outer peripheral surface of the photoreceptor. Further, the charging roll 70 includes a metal cored bar 22 and an elastic layer 72 including a conductive rubber material G coated on the outer peripheral surface of the cored bar 22.

[Roll manufacturing equipment]
FIG. 1 shows a roll manufacturing apparatus 10 as an example of the present embodiment. The roll manufacturing apparatus 10 includes a discharge unit 12 that discharges the rubber material G and the cored bar 22, an extraction unit 16 that is disposed below the discharge unit 12 and extracts a rubber roll unit 56 that will be described later, and the discharge unit 12 and the extraction unit 16. And a pressing portion 14 that presses the rubber material G. In the following description, the front (lower) cored bar 22 may be referred to as a cored bar 22A, and the rear (upper) cored bar 22 may be referred to as a cored bar 22B. In the case where the front core metal 22A and the rear core metal 22B are not distinguished, the core metal 22 will be described.

[Discharge part]
The discharge unit 12 is constituted by a so-called cross head die. The discharge unit 12 includes a supply unit 18 that supplies the unvulcanized rubber material G, an extrusion unit 20 that extrudes the rubber material G supplied from the supply unit 18 in a cylindrical shape, and a cylindrical shape that is extruded from the extrusion unit 20. And a feeding portion 24 that feeds the cored bar 22 at an interval from the central portion C of the rubber material G.

<Supply section>
The supply unit 18 is provided with a screw 28 rotatably inside a cylindrical main body 26 extending in the illustrated horizontal direction. The screw 28 is rotationally driven by a supply motor 30 with the illustrated lateral direction as an axial direction. The operation of the supply motor 30 is controlled by a control unit 80 described later. In addition, on the supply motor 30 side of the main body portion 26, a charging port 32 for charging the rubber material G is provided. Thereby, the rubber material G introduced from the insertion port 32 is supplied toward the extrusion unit 20 while being kneaded by the screw 28 inside the main body 26. In the supply unit 18, the supply speed of the rubber material G is adjusted by adjusting the rotation speed of the screw 28.

(Rubber material)
The rubber material G contains a rubber material, a processing aid, a conductive agent, a plasticizer, a vulcanization accelerator, and the like. In the present embodiment, epichlorohydrin rubber is used as an example of the rubber material, and carbon black is used as an example of the conductive agent.

  The rubber material is not limited to epichlorohydrin rubber, but isoprene rubber, chloroprene rubber, butyl rubber, polyurethane, silicone rubber, fluorine rubber, styrene-butadiene rubber, butadiene rubber, nitrile rubber, ethylene propylene rubber, epichlorohydrin-ethylene oxide copolymer rubber, epichlorohydrin- Examples include ethylene oxide-allyl glycidyl ether copolymer rubber, ethylene-propylene-diene terpolymer rubber (EPDM), acrylonitrile-butadiene copolymer rubber (NBR), natural rubber, and blend rubbers thereof. Among these, polyurethane, silicone rubber, EPDM, epichlorohydrin-ethylene oxide copolymer rubber, epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber, NBR, and blended rubbers thereof are preferably used. These rubber materials may be foamed or non-foamed.

  As the conductive agent, an electronic conductive agent or an ionic conductive agent is used. Examples of electronic conductive agents include carbon blacks such as ketjen black and acetylene black; pyrolytic carbon, graphite; various conductive metals or alloys such as aluminum, copper, nickel, stainless steel; tin oxide, indium oxide, titanium oxide And various conductive metal oxides such as tin oxide-antimony oxide solid solution, tin oxide-indium oxide solid solution; and the like.

  Examples of the ionic conductive agent include perchlorates and chlorates such as tetraethylammonium and lauryltrimethylammonium; alkali metals such as lithium and magnesium, perchlorates and chlorates of alkaline earth metals, and the like.

  These conductive agents may be used alone or in combination of two or more. There is no restriction | limiting in particular in the addition amount of a electrically conductive agent. In the case of an electronic conductive agent, it is preferably in the range of 1 to 40 parts by mass, more preferably in the range of 10 to 30 parts by mass with respect to 100 parts by mass of the rubber material. More preferably, it is in the range of 15 to 25 parts by mass. In the case of an ionic conductive agent, the range is preferably 0.1 parts by weight or more and 5.0 parts by weight or less, and 0.5 parts by weight or more and 3.0 parts by weight or less with respect to 100 parts by weight of the rubber material. It is more preferable that Thus, the rubber material G has high conductivity.

<Extruded part>
The extrusion unit 20 includes a cylindrical case 34 connected to the supply unit 18, a columnar mandrel 36 disposed at the center of the case 34, and a discharge head 38 disposed below the mandrel 36. ing.

  The mandrel 36 is held by a holding member 40 attached to the upper side of the case 34. The discharge head 38 is held by a holding member 42 attached to the lower side of the case 34. The rubber material G flows in an annular shape (cylindrical shape) between the outer peripheral surface of the mandrel 36 (the outer peripheral surface of the holding member 40) and the inner peripheral surface of the holding member 42 (the inner peripheral surface of the discharge head 38). An annular channel 44 is formed.

  Further, an insertion hole 46 into which the cored bar 22 is inserted is formed in the center of the mandrel 36 with the vertical direction shown in the figure as the axial direction. Furthermore, the lower part of the mandrel 36 has a tapered shape toward the lower end. A lower region below the mandrel 36 is a joining portion 48 where the core metal 22 supplied from the insertion hole 46 and the rubber material G supplied from the annular flow path 44 merge. That is, in the extruding part 20, the rubber material G is extruded in a cylindrical shape toward the joining part 48, and the cored bar 22 is fed into the central part C of the rubber material G that is extruded in a cylindrical shape.

  Here, the rubber material G flows through the merging portion 48 and is extruded from the extruding portion 20 without the cored bar 22. The speed at this time is referred to as an extrusion speed. That is, the extrusion speed is the speed of the rubber material G (substantially constant speed) when the rubber material G is pushed out of the discharge head 38 by the rotation of the screw 28 without the cored bar 22.

<Sending part>
The feeding unit 24 has a roll pair 50 disposed above the mandrel 36. A plurality of roll pairs 50 (three pairs as an example) are provided, and one roll of each roll pair 50 is rotated by a driving roll 54 via a belt 52. The drive roll 54 is configured such that a rotation speed (feeding speed described later) is controlled by a control unit 80 described later.

  Specifically, the drive roll 54 is rotationally driven by the drive motor 84. The operation of the drive motor 84 is controlled by the motor driver 82. Further, the operation of the motor driver 82 is controlled by the control unit 80. As a result, when the drive roll 54 is driven by the drive motor 84, the cored bar 22 sandwiched by each pair of rolls 50 is sent toward the insertion hole 46 of the mandrel 36.

<Control unit>
As shown in FIG. 2, the control unit 80 includes a computer. And the roll manufacturing program for making a computer function as an example of a control means is set to the control part 80. FIG.

  Specifically, the control unit 80 includes a CPU (Central Processing Unit) 80A, a ROM (Read Only Memory) 80B, a RAM (Random Access Memory) 80C, and a nonvolatile memory 80D. The control unit 80 has a configuration in which a CPU 80A, a ROM 80B, a RAM 80C, a nonvolatile memory 80D, and an input / output interface (I / O) 80E are connected to each other via a bus 80F.

  A motor driver 82 is electrically connected to the input / output interface 80E, and the motor driver 82 is electrically connected to the drive motor 84. In this case, for example, a roll manufacturing program is written in the ROM 80B and is read by the CPU 80A, whereby the CPU 80A controls the motor driver 82. The non-volatile memory 80D may be connected to the outside of the control unit 80 via the input / output interface 80E, and may be an external storage device such as a memory card, for example.

  Further, the control unit 80 shown in FIG. 1 controls the decrease and increase in the speed at which the core bar 22 is fed into the rubber material G by the feeding section 24 (hereinafter referred to as the feeding speed). As an example, the feeding speed of the core bar 22 by the feeding section 24 is higher than the extrusion speed of the rubber material G and the speed V2 (see FIG. 6 (B)) of the rubber roll section 56 by the take-out section 16 described later. Is set.

  The total length of the cored bar 22 is set to a predetermined length L (see FIG. 3A). Here, the rear core metal 22B sent by the roll pair 50 pushes the front core metal 22A existing in the insertion hole 46 of the mandrel 36, and the front core metal 22A is taken out by the extraction portion 16. It is. For this reason, the plurality of metal cores 22 are sequentially moved in the insertion hole 46.

  Further, the driving of the drive roll 54 is temporarily stopped when the front end (lower end) of each cored bar 22 is positioned at the front end (lower end) of the mandrel 36. On the other hand, even when the drive roll 54 is temporarily stopped, the rubber material G continues to be pushed out. For this reason, the cored bar 22 is fed at an interval in the junction 48 below the mandrel 36.

  As described above, in the discharge unit 12, the rubber material G is pushed out in a cylindrical shape at the merging portion 48, and a plurality of core bars whose speeds are controlled by a quadratic curve, which will be described later, are spaced from the central portion C of the rubber material G. 22 are sequentially sent. As a result, the cored bar 22 exists in the central part C of the rubber material G between the rubber roll 56 in which the outer peripheral surface of the cored bar 22 is covered with the rubber material G, and the front cored bar 22 and the rear cored bar 22. The hollow portions 58 as an example of the intermediate portion not to be discharged are alternately discharged from the discharge head 38. Note that a primer (not shown) is applied in advance to the outer peripheral surface of the cored bar 22 in order to improve the adhesiveness with the rubber material G.

  As shown in FIG. 3B, the rubber roll portion 56 is formed by covering the outer peripheral surface of the cored bar 22 and the end surfaces 68 at both axial ends of the cored bar 22 with the rubber material G. The charging roll 70 is a state in which the rubber material G at both axial ends of the rubber roll portion 56 is cut along the radial direction of the cored bar 22 and both ends of the cored bar 22 are exposed (see FIG. 3C). It is.

<Pressing part>
As shown in FIG. 1, the pressing portion 14 has a pair of semi-cylindrical pressing members 60. The pair of pressing members 60 are disposed to face each other so as to sandwich the rubber roll portion 56 discharged from the discharge portion 12. Each pressing member 60 is formed with a protruding portion 62 that protrudes toward the rubber roll portion 56. Each pressing member 60 is movable in the horizontal direction and vertical direction shown in the figure by a drive mechanism (not shown). The pair of pressing members 60 presses the hollow portion 58 that is a part of the rubber material G without the core metal 22 between the front core metal 22A and the rear core metal 22B, so that the rubber material G is cut off.

<Extraction department>
The extraction part 16 has a pair of semi-cylindrical extraction members 64. The pair of extraction members 64 are disposed to face each other so as to sandwich the rubber roll portion 56 discharged from the discharge portion 12. Each extraction member 64 is formed with a grip portion 66 having a shape corresponding to the outer peripheral surface shape of the rubber roll portion 56. Each extraction member 64 can be moved in the horizontal direction and the vertical direction in the figure by a drive mechanism (not shown). The speed at which the rubber roll 56 is taken out (pulled out) by the takeout member 64 is referred to as the takeout speed.

(Setting of sending speed)
Next, the setting of the feeding speed of the cored bar 22 in the control unit 80 will be described.

  The charging roll 70 (see FIG. 3C) is rotated while being pressed against a rotating photoreceptor (not shown). At this time, if the contact width (nip width) between the charging roll 70 and the photosensitive member is not uniform in the axial direction, the electric field strength becomes non-uniform in the axial direction, which may cause uneven charging. As a method for aligning the nip area, it is known that the outer shape of the charging roll is a crown shape (a shape in which the outer diameter on the axial center side is larger than the outer diameters on both ends).

  As a manufacturing method of the crown-shaped charging roll 70, rubber that increases in moving speed from the center to the rear end during compression of the rubber material G whose moving speed decreases from the axial front end to the center of the cored bar 22 is used. There is a method of changing the feeding speed of the cored bar 22 when the material G is pulled. Specifically, there is a quadratic curve control method for controlling the feeding speed of the cored bar 22 with a quadratic curve.

  Here, when the feeding speed of the cored bar 22 is controlled by the quadratic curve control method from the front end position to the rear end position in the axial direction of the cored bar 22, the elastic layer 72 on the front end (lower end) side (FIG. 3 ( It was confirmed that the outer diameter of C) was larger than the set outer diameter. This phenomenon is presumed to be because the rubber material G that continues to be extruded at the set extrusion speed has a reservoir of the rubber material G, and a large residual stress is generated in the reservoir. That is, it is considered that the residual stress is released at the moment when the rubber roll portion 56 is discharged from the extruding portion 20, thereby increasing the thickness of the front end side of the rubber roll portion 56. In other words, it is considered that the amount of the rubber material G per unit length in the hollow portion 58 is reduced if the feeding speed on the tip side of the cored bar 22 is increased more than the speed of the quadratic curve control method. It is done.

<Evaluation of charging roll>
In order to increase the speed on the tip side of the core metal 22 beyond the speed of the quadratic curve control, the charging roll 70 is manufactured under each condition described later, and the outer diameter ratio and image evaluation of the obtained charging roll 70 are performed. It was.

  In the evaluation of the charging roll 70, the rubber material G is prepared by kneading a material containing epichlorohydrin rubber as a main component and blending a processing aid, carbon black, calcium carbonate, a plasticizer, a vulcanizing agent, and a vulcanization accelerator. Obtained. The rubber material G had a Mooney viscosity of 50 according to JISK6300-1 (2001). Further, the cored bar 22 used in this evaluation is made of SUS (stainless steel) having L (full length) = 354.5 [mm] and an outer diameter φ8.0 [mm]. The extruder used is a Mitsuba Seisakusho φ60 [mm], a screw effective length L and a screw outer diameter D ratio (L / D) of 20, screw rotation speed 10 [rpm], die diameter Was 12.5 [mm] and the extrusion pressure was 23 [MPa].

  The unvulcanized rubber material G was extruded with an extruder, and the cored bar 22 was continuously fed into the rubber material G under each setting condition described later. After that, charging is performed at 165 [° C.] in a 75 [min] hot air furnace for vulcanization, and a charging roll 70 in which an elastic layer 72 as a vulcanized rubber layer of the rubber material G is formed on the cored bar 22 (FIG. 3 ( C)) was obtained. The rubber material G at both ends of the vulcanized charging roll 70 was cut to expose the cored bar 22. For measurement of the outer diameter of the charging roll 70, a light-shielding laser outer diameter measuring device (manufactured by Asaka Riken: ROLL2000) was used.

  Here, assuming that the axial length of the cored bar 22 is 100%, the length in the axial direction from the tip of the cored bar 22 is expressed as a ratio, and the length from the tip is 0, 0.3, 1.4, The positions of 2.8, 8.5, 14.1, and 17 [%] were set as the end positions of the sections in which the speed was increased more than the speed by the quadratic curve control. And in the setting conditions of each end position, in the whole area from the front-end | tip of the metal core 22 to each end position, the feeding speed was made to increase rather than the speed by quadratic curve control.

  For example, the condition of the end position 1.4 [%] is that the feeding speed of the core metal 22 to be controlled in the entire section from the tip position (0 [%]) of the core metal 22 to the 1.4 [%] position. Means that the speed is higher than the feeding speed by the quadratic curve control. Further, as an example, the speed increase of the cored bar 22 is controlled at a constant speed in the entire section from the tip of the cored bar 22 to the end position, and then shifted to the quadratic curve control (see FIG. 4).

  As shown in FIG. 4, the lowest speed among the feeding speeds of the cored bar 22 that is subjected to quadratic curve control by the control unit 80 (see FIG. 1) is defined as a reference speed Va (see FIG. 4), and the tip position (0 [ %]) To the end position P1 is defined as Vb. Here, speed ratio = Vb / Va × 100 [%]. The speed ratio was changed to 100, 110, 120, 150, 175, 200, 300, 320 [%], and the outer shape was evaluated. In FIG. 4, the vertical axis of the graph G1 representing the feeding speed is shown enlarged. Further, in FIG. 4, the speed when the quadratic curve control is performed from the tip position to the end position P1 is indicated by a two-dot chain line.

  The reference speed Va is set in accordance with the portion where the outer diameter of the charging roll 70 shown in FIG. 3C is the largest. However, since it is necessary to consider the responsiveness of the rubber material G, the shaft of the core bar 22 is used. The speed at which the center position in the direction is sent out is not always the reference speed Va. In FIG. 4, as an example, the reference speed Va is set at a position P2 on the tip side of the position 50 [%].

  In the outer shape evaluation of the charging roll 70, the ratio of the outer diameter of the elastic layer 72 at the tip end portion to the outer diameter of the elastic layer 72 at the rear end portion of the charging roll 70 (see FIG. 3C) is defined as an outer diameter ratio [%]. Evaluation was made in three stages. Specifically, the outer diameter ratio is 100% or more and 150% or less A, the outer diameter ratio is larger than 150% and less than 200% B, and the outer diameter ratio is 200. [%] Or more was C, and the outer diameter was less than 100 [%]. The leading end portion of the charging roll 70 means the lower end position of the rubber material G (elastic layer 72) of the charging roll 70, and the rear end portion means the rubber material G (elastic layer 72) of the charging roll 70. This means the upper end position.

  Further, the charging roll 70 having a different outer diameter ratio was attached to an image forming apparatus (manufactured by Fuji Xerox Co., Ltd .: Docu Center-IV C2260, voltage applied to the charging roll 70 -1000 [V]), and image evaluation was performed. . The image evaluation was performed by forming a gray solid image with a set number of sheets and visually observing the density unevenness of the image after fixing the last one sheet. The image evaluation results were evaluated in a two-step evaluation, with ◯ indicating that no density unevenness was visually confirmed, and x indicating that density unevenness was visually confirmed.

  FIG. 8A shows the evaluation results from Example 1 to Example 9, which is an example of the charging roll 70 of this embodiment (see FIG. 3C). FIG. 8B shows the evaluation results of the charging rolls (not shown) from Comparative Example 1 to Comparative Example 4.

  As for the image evaluation result, a correlation with the outer diameter ratio was observed. Specifically, for Example 1 to Example 9 in which the outer diameter ratio is A or B, the image evaluation result was “good”. On the other hand, for Comparative Examples 1 to 4 in which the outer diameter ratio was C, the image evaluation result was x. That is, the ratio (outer diameter ratio) between the outer diameter of the rubber material G at the front end portion in the axial direction of the core bar 22 and the outer diameter of the rubber material G at the rear end portion shown in FIG. It is desirable to set the position from the tip and the speed ratio so that it is less than 200 [%].

  Here, from the evaluation results of FIGS. 8A and 8B, the axial total length of the cored bar 22 (see FIG. 3C) is set to 100 [%], and the end position of acceleration with respect to the quadratic curve control is determined. It was confirmed that it is desirable to set it within the range of 1.4 [%] to 8.5 [%]. Further, it was confirmed that when the feeding speed of the cored bar 22 is increased, it is desirable that the speed ratio of the feeding speed with respect to the reference speed described above is 120% or more and 300% or less. As described above, it is confirmed that it is desirable to increase the feeding speed of the cored bar 22 when feeding the axial tip of the cored bar 22 to the center part C of the rubber material G more than the speed by the quadratic curve control. It was done.

  In the roll manufacturing apparatus 10 (see FIG. 1), based on the evaluation result, as an example, the end position of the increase in the feeding speed is set to 2.8 [%], the speed ratio is set to 175 [%], and the outer diameter The charging roll 70 with the ratio A is set to be manufactured. That is, the feeding speed of the cored bar 22 is changed according to the speed control pattern of the graph G1 shown in FIG.

[Action]
Next, the operation of this embodiment will be described.

  When the roll manufacturing apparatus 10 shown in FIG. 1 is started, the supply motor 30 is driven. Thereby, the screw 28 is rotationally driven, and the unvulcanized rubber material G is extruded in a cylindrical shape at a predetermined extrusion speed V1 (see FIG. 5A).

  Subsequently, the drive motor 84 is driven, and the drive roll 54 and the roll pair 50 are rotated. Thereby, as shown to FIG. 5 (A), 22 A of front metal bars begin to be sent in the center part C of the rubber material G at the sending speed Vb. The feeding speed Vb is a speed of 175 [%] with respect to the above-described reference speed Va (see FIG. 4). In addition, although illustration is abbreviate | omitted, the front-end | tip (lower end) of the core metal 22A is covered with the rubber material G when the pressing member 60 moves to a horizontal direction.

  Subsequently, as shown in FIG. 5B, a portion (position) where the length Lx = 2.8 [%] from the tip (lower end) of the mandrel 22 to the lower end of the mandrel 36 is at the lower end of the mandrel 36. After reaching, the feeding speed of the core metal 22A is controlled by a quadratic curve according to the graph G1 (see FIG. 4).

  Subsequently, as shown in FIGS. 5C and 6A, the rubber roll portion 56 (the core metal 22A and the rubber material G) is taken out (pulled) by the take-out portion 16.

  Subsequently, as illustrated in FIG. 6B, the rubber roll portions 56 and the hollow portions 58 in which the central portion C of the rubber material G is hollow are discharged alternately. At this time, the feeding speed of the cored bar 22B is also controlled for the rear cored bar 22B in accordance with the graph G1 (see FIG. 4), similarly to the preceding cored bar 22A.

  Subsequently, as shown in FIG. 7A, when the hollow portion 58 moves to the position opposite to the pressing member 60, each pressing member 60 is moved in a direction approaching each other, and the rubber material G of the hollow portion 58 is It is pressed inward by the protrusion 62 of the pressing member 60. As a result, as shown in FIG. 7B, the end surface 68 of the front metal core 22A and the end surface 68 of the rear metal core 22B are covered with the rubber material G of the hollow portion 58.

  Subsequently, as shown in FIG. 7C, when the pressing members 60 are moved away from each other, the cored bar 22 is formed into a bag-like shape (both ends of the cored bar 22A are covered with the rubber material G). E) The charging roll 70 is formed. Each take-out member 64 moves downward while gripping the separated rubber roll portion 56 and then moves to a standby position for gripping the next rubber roll portion 56. And the charging roll 70 (refer FIG.3 (C)) is obtained by performing the above-mentioned vulcanization process and the cutting process of the rubber material G of both ends about the obtained rubber roll part 56. FIG.

  Here, as an example, when the outer diameter ratio of the obtained charging roll 70 was measured by the method described above, it was 140 [%], and the outer diameter ratio was in the range of 100 [%] to less than 200 [%]. It was confirmed that

  As described above, according to an example of the roll manufacturing method of the present embodiment, when the rubber material G stays in the hollow portion 58 between the front rubber roll portion 56 and the rear rubber roll portion 56. The cored bar 22 increased in speed than the speed by the quadratic curve control is fed into the rubber material G. For this reason, compared with the case where the rubber material G staying in the hollow portion 58 controls the feeding speed of the cored bar 22 to a quadratic curve, it is suppressed that the rubber material G is locally attached to the tip end part of the cored bar 22. Is done. Thereby, when the feeding speed of the cored bar 22 is controlled by a quadratic curve, the outer diameter of the rubber material G at the tip of the cored bar 22 is compared with the configuration in which the feeding speed is not increased by the quadratic curve control. Is suppressed from increasing with respect to the rear end portion.

  Further, according to an example of the roll manufacturing method of the present embodiment, assuming that the axial total length of the cored bar 22 is 100 [%], the speed increasing end position of the cored bar 22 is 1.4 [%] or more and 8.5. [%] It is set within the following range. As a result, the speed of the cored bar 22 is increased more than the speed of the quadratic curve control in a place where the rubber material G tends to stay, so that it is outside the range of 1.4 [%] or more and 8.5 [%] or less. Compared to the configuration in which the acceleration end position is set, an increase in the outer diameter of the rubber material G at the tip of the cored bar 22 is suppressed.

  Furthermore, according to an example of the roll manufacturing method of the present embodiment, when the feeding speed of the cored bar 22 is increased with the lowest feeding speed of the feeding speed of the cored bar 22 as the reference speed Va, The speed ratio with respect to the reference speed Va is set to 120 [%] or more and 300 [%] or less. Here, as a comparative example, when the speed ratio is smaller than 120 [%], the rubber material G easily adheres locally to the cored bar 22 and the outer diameter increases. When the speed ratio is larger than 300 [%], the acceleration of the cored bar 22 increases, the rubber material G extends, and the outer diameter of the tip portion decreases. On the other hand, in the method of the present embodiment, the local adhesion of the rubber material G or the decrease in the outer diameter is suppressed by setting the speed ratio to 120 [%] or more and 300 [%] or less. For this reason, as compared with a configuration in which the speed ratio is not set to 120% or more and 300% or less, the outer diameter of the rubber material G is suppressed from being increased or excessively reduced at the tip portion of the cored bar 22.

  Moreover, according to an example of the manufacturing method of the charging roll of this embodiment, when the feeding speed of the core metal 22 is controlled by a quadratic curve, the outer diameter of the rubber material G at the front end portion of the core metal 22 becomes the rear end portion. An increase compared to the above is suppressed. That is, an increase in the outer diameter of the elastic layer 72 at the tip of the cored bar 22 is suppressed.

  In addition, this invention is not limited to said embodiment.

  In FIG. 9A, the feeding speed of the cored bar 22 (see FIG. 3C) is changed from the tip position 0% to the end position P1 [ %]], And the graph G1 of the above-described embodiment in which the quadratic curve control is performed thereafter is shown. However, the present invention is not limited to the constant speed from the tip position 0 [%] to the end position P1 [%] as described above.

  For example, as shown in FIG. 9 (B), the tip speed of the cored bar 22 is linear from the tip position 0 [%] to the end position P1 [%] with respect to quadratic curve control (two-dot chain line graph). It is good also as the graph G2 to which it decelerates to 2nd curve control after the end position P1. Moreover, you may decelerate in a curve from the front-end | tip position 0 [%] to the end position P1 [%] in the range accelerated from a quadratic curve control.

  The means for extruding the rubber material G is not limited to a screw shape, and may be a piston shape. Further, the feeding means for the cored bar 22 is not limited to the roll pair, and may be a moving member having a gripping portion. Furthermore, the take-out means of the rubber roll unit 56 is not limited to the one that grips and moves the rubber roll unit 56, but may be moved by a roll pair.

  If the outer diameter ratio of the charging roll 70 is set to 100 [%] or more and less than 200 [%] for the setting of the position for increasing the speed, the position where the acceleration is finished is 1.4 [%] or more and 8. The position may be outside the range of 5% or less. In addition, the speed ratio may be a value different from 120% or more and 300% or less as long as the outer diameter ratio of the charging roll 70 is 100% or more and less than 200%. .

  In the roll manufacturing apparatus 10, the charging roll 70 is separated by the hollow portion 58 by the pressing portion 14. However, after the rubber material of the hollow portion 58 is pressed inward by the pressing portion 14, another cutting member (not shown) is illustrated. You may comprise so that the charging roll 70 may be isolate | separated by (cutter).

  Although the rubber material G illustrated what used epichlorohydrin rubber, it is not restricted to this, You may use another rubber material. Further, in the charging roll 70, the entire end surface 68 of the cored bar 22 was covered with a rubber material G in the hollow part 58 in a bag-like shape. However, the present invention is not limited to this, and at least the peripheral part of the end surface 68 of the cored bar 22 is What is necessary is just to be covered with the rubber material G of the hollow part 58. FIG.

  A roll (finished product) obtained by the roll manufacturing method of the present embodiment is used in an image forming apparatus such as a copying machine or a printer. It may be used for a transfer roll or the like.

10 roll manufacturing equipment,
22 Core 56 Rubber roll 58 Hollow part (an example of an intermediate part)
70 Charging roll (an example of a roll)
72 Elastic layer G Rubber material

In a method of manufacturing a plurality of rolls by feeding a plurality of core bars at intervals while extruding a rubber material, the movement speed of the core metal is determined from the position from the axial end of the core metal and the movement speed of the core metal. In the configuration of controlling the speed represented by a curve in which the moving speed decreases from the axial front end to the center of the core metal and the moving speed increases from the center to the rear end of the core metal , a constant speed In some cases, the rubber material that is pushed out at the end of the core bar collects. Accordingly, there is a possibility that the outer diameter of the rubber material is increased from the determined outer diameter at the tip of the core metal of the roll.

In the method of manufacturing a plurality of rolls by feeding a plurality of metal cores at intervals while extruding a rubber material, the present invention does not increase the feeding speed at the tip of the metal core from the speed controlled by the speed control. Compared to the configuration, an object is to suppress an increase in the outer diameter of the rubber material at the tip of the core metal when the extrusion speed of the core metal is controlled.

In the roll manufacturing method according to claim 1 of the present invention, the relationship between the position of the cored bar from the axial tip and the moving speed of the cored bar is spaced from the central part of the rubber material extruded in a cylindrical shape. sequentially feeding a plurality of said metal core at a rate controlling the movement speed from the axial tip of the metal core to the center from the rear end of the metal core will slow moving speed toward the center is represented by go faster curve, said metal core rubber roller portion outer peripheral surface is coated with the rubber material, and an intermediate portion, not the core metal is present in the center of the rubber material in between other party of the metal core and the rear of said core metal It is a manufacturing method of the roll discharged alternately, Comprising: Ratio of the outer diameter of the rubber material in the tip part of the direction of an axis of the core metal and the outer diameter of the rubber material in the rear end part is 100% or more and less than 200% So that the axial tip of the cored bar is fed into the central part A constant velocity the infeed speed of the metal core and speed higher than the speed by the speed control.

Roll manufacturing method according to claim 3 of the present invention, as reference speed to lowest infeed speed of the infeed speed of the core metal that is the speed control, the speed increasing the infeed rate of the metal core Sometimes, the ratio of the feeding speed to the reference speed is 120% or more and 300% or less.

The invention of claim 1 is a method for producing a plurality of rolls by feeding at intervals a plurality of core metal while extruding rubber material in the rubber material, the speed of the speed control infeed speed of the tip portion of the core metal Compared to a configuration in which the speed is not increased, it is possible to suppress an increase in the outer diameter of the rubber material at the tip of the core metal when the extrusion speed of the core metal is controlled.

The invention of claim 4 can suppress an increase in the outer diameter of the elastic layer at the tip of the cored bar as compared with a configuration in which the feeding speed of the cored bar is not increased from the speed controlled by the speed control.

It is sectional drawing which shows the structure of the roll manufacturing apparatus which concerns on this embodiment. It is a block diagram of the control part concerning this embodiment. (A) It is a schematic diagram of the metal core which concerns on this embodiment. (B) It is sectional drawing of the rubber roll part which concerns on this embodiment. (C) It is a schematic diagram of the charging roll which concerns on this embodiment. It is a graph which shows the change with respect to the position of the axial direction of the feeding speed of the metal core which concerns on this embodiment. (A), (B), (C) It is sectional drawing which shows the state from which the metal core which concerns on this embodiment is sent into a rubber material, and is taken out. (A), (B) It is sectional drawing which shows the state from which the rubber roll part which concerns on this embodiment is taken out by the extraction part. (A), (B), (C) It is sectional drawing which shows the state which presses the hollow part which concerns on this embodiment with a pressing member. (A) It is a table | surface which shows the measurement result of the position from the front-end | tip, the speed ratio, and the outer diameter ratio in Example 1 to Example 9 of this embodiment. (B) It is a table | surface which shows the measurement result of the position from the front-end | tip, the speed ratio, and the outer diameter ratio in the comparative example 1 to the comparative example 4 of this embodiment. (A) It is explanatory drawing which compared the line of the feeding speed of the metal core of this embodiment, and the line of the feeding speed by speed control. (B) It is explanatory drawing which compared the line of the feeding speed of the metal core in the modification of this embodiment, and the line of the feeding speed by speed control.

Thus, the discharge unit 12, together with the extruded rubber material G into a cylindrical shape in the merging portion 48, at an interval in the center C of the rubber material G, a plurality of core bar 22 the speed which is the speed control will be described later , Are sent sequentially. As a result, the cored bar 22 exists in the central part C of the rubber material G between the rubber roll 56 in which the outer peripheral surface of the cored bar 22 is covered with the rubber material G, and the front cored bar 22 and the rear cored bar 22. The hollow portions 58 as an example of the intermediate portion not to be discharged are alternately discharged from the discharge head 38. Note that a primer (not shown) is applied in advance to the outer peripheral surface of the cored bar 22 in order to improve the adhesiveness with the rubber material G.

As a manufacturing method of the crown-shaped charging roll 70, rubber that increases in moving speed from the center to the rear end during compression of the rubber material G whose moving speed decreases from the axial front end to the center of the cored bar 22 is used. There is a speed control method represented by a curve that changes the feeding speed of the cored bar 22 when the material G is pulled .

Here, when the feeding speed of the cored bar 22 is controlled by the above-described speed control method from the front end position to the rear end position of the cored bar 22 in the axial direction, the elastic layer 72 on the front end (lower end) side (FIG. 3). The phenomenon that the outer diameter of (see (C)) becomes larger than the set outer diameter was confirmed. This phenomenon is presumed to be because the rubber material G that continues to be extruded at the set extrusion speed has a reservoir of the rubber material G, and a large residual stress is generated in the reservoir. That is, it is considered that the residual stress is released at the moment when the rubber roll portion 56 is discharged from the extruding portion 20, thereby increasing the thickness of the front end side of the rubber roll portion 56. In other words, the amount of the rubber material G per unit length in the hollow portion 58 is reduced if the feeding speed on the tip side of the cored bar 22 is increased from the speed control method described above. Conceivable.

<Evaluation of charging roll>
In order to increase the speed on the tip end side of the core metal 22 from the speed control speed described above, the charging roll 70 is manufactured under each condition described later, and the outer diameter ratio and image evaluation of the obtained charging roll 70 are performed. went.

Here, assuming that the axial length of the cored bar 22 is 100%, the length in the axial direction from the tip of the cored bar 22 is expressed as a ratio, and the length from the tip is 0, 0.3, 1.4, The positions of 2.8, 8.5, 14.1, and 17 [%] were set as the end positions of the sections where the speed was increased from the speed by the speed control described above . And in the setting conditions of each end position, the feeding speed was increased from the speed of the speed control described above in the entire section from the tip of the core metal 22 to each end position.

For example, the condition of the end position 1.4 [%] is that the feeding speed of the core metal 22 to be controlled in the entire section from the tip position (0 [%]) of the core metal 22 to the 1.4 [%] position. Means that the speed is higher than the feeding speed by the speed control described above . As an example, the speed increase of the cored bar 22 is controlled at a constant speed in the entire section from the tip of the cored bar 22 to the end position, and then the speed control described above is performed (see FIG. 4). .

As shown in FIG. 4, the lowest speed among the feeding speeds of the cored bar 22 whose speed is controlled by the control unit 80 (see FIG. 1) is set as the reference speed Va (see FIG. 4), and the tip position (0 Let Vb be a constant feed speed from [%] to the end position P1. Here, speed ratio = Vb / Va × 100 [%]. The speed ratio was changed to 100, 110, 120, 150, 175, 200, 300, 320 [%], and the outer shape was evaluated. In FIG. 4, the vertical axis of the graph G1 representing the feeding speed is shown enlarged. In FIG. 4, the speed when the speed control described above is performed from the tip position to the end position P <b > 1 is indicated by a two-dot chain line.

Here, based on the evaluation results of FIGS. 8A and 8B, the axial total length of the cored bar 22 (see FIG. 3C) is 100%, and the end position of the speed increase with respect to the speed control described above. It was confirmed that it is desirable to set the value within the range of 1.4 [%] to 8.5 [%]. Further, it was confirmed that when the feeding speed of the cored bar 22 is increased, it is desirable that the speed ratio of the feeding speed with respect to the reference speed described above is 120% or more and 300% or less. Thus, it is desirable that the feeding speed of the cored bar 22 when the axial tip end of the cored bar 22 is fed into the central part C of the rubber material G is higher than the speed by the speed control described above. confirmed.

Subsequently, as shown in FIG. 5B, a portion (position) where the length Lx = 2.8 [%] from the tip (lower end) of the mandrel 22 to the lower end of the mandrel 36 is at the lower end of the mandrel 36. after having reached the infeed speed of the core 22A is speed controlled according to the graph G1 (see FIG. 4).

As described above, according to an example of the roll manufacturing method of the present embodiment, when the rubber material G stays in the hollow portion 58 between the front rubber roll portion 56 and the rear rubber roll portion 56. The cored bar 22 increased in speed from the speed controlled by the speed control described above is fed into the rubber material G. For this reason, the rubber material G staying in the hollow portion 58 may locally adhere more to the tip of the core metal 22 than when the feed speed of the core metal 22 is controlled as described above. It is suppressed. Thus, when the speed control the infeed speed of the metal core 22, as compared with the configuration not speed higher than the infeed speed of aforementioned speed control, the outer diameter of the rubber member G is at the tip of the core bar 22 An increase with respect to the rear end portion is suppressed.

Further, according to an example of the roll manufacturing method of the present embodiment, assuming that the axial total length of the cored bar 22 is 100 [%], the speed increasing end position of the cored bar 22 is 1.4 [%] or more and 8.5. [%] It is set within the following range. As a result, the speed of the cored bar 22 is increased more than the speed control speed described above at a place where the rubber material G tends to stay, so that it is outside the range of 1.4 [%] or more and 8.5 [%] or less. In comparison with the configuration in which the end position of the acceleration is set at the end, an increase in the outer diameter of the rubber material G at the tip portion of the cored bar 22 is suppressed.

Moreover, according to an example of the manufacturing method of the charging roll of this embodiment, when the feeding speed of the cored bar 22 is controlled as described above, the outer diameter of the rubber material G is the rear end of the leading end of the cored bar 22. It is suppressed from increasing compared to. That is, an increase in the outer diameter of the elastic layer 72 at the tip of the cored bar 22 is suppressed.

In FIG. 9 (A), the feeding speed of the cored bar 22 (see FIG. 3 (C)) is changed from the tip position 0 [%] to the end position P1 with respect to the speed control (two-dot chain line graph) described above . The graph G1 of the above-described embodiment in which the above-described speed control is performed is shown after the feed rate Vb is substantially constant until [%]. However, the present invention is not limited to the constant speed from the tip position 0 [%] to the end position P1 [%] as described above.

For example, as shown in FIG. 9B, the tip speed of the cored bar 22 is a straight line from the tip position 0 [%] to the end position P1 [%] with respect to the speed control described above (two-dot chain line graph). It is good also as the graph G2 which makes it decelerate automatically and speed- controls as stated above after the end position P1. Further, the vehicle may be decelerated in a curve from the tip position 0 [%] to the end position P1 [%] within a range in which the speed is increased as compared with the speed control described above .

Claims (4)

A rubber roll part in which a plurality of cores are sequentially fed at a speed controlled by a quadratic curve at an interval at the center part of the rubber material extruded in a cylindrical shape, and an outer peripheral surface of the core metal is covered with the rubber material, A method of manufacturing a roll that alternately discharges an intermediate portion in which a core metal does not exist in a central portion of the rubber material between a front core metal and a rear core metal,
The tip end in the axial direction of the core metal so that the ratio of the outer diameter of the rubber material at the tip end portion in the axial direction of the core metal to the outer diameter of the rubber material at the rear end portion is 100% or more and less than 200%. A roll manufacturing method in which the feeding speed of the cored bar when feeding a part into the central part is increased more than the speed by the quadratic curve control.   The axial end length of the cored bar is 100%, and the end position that is a position from the tip of the cored bar and ends the speed increase is in the range of 1.4% to 8.5%. Manufacturing method of the roll. The lowest feeding speed among the feeding speeds of the core bar controlled by the quadratic curve is set as a reference speed,
The roll manufacturing method according to claim 2, wherein when the feeding speed of the core metal is increased, a ratio of the feeding speed to the reference speed is set to 120% or more and 300% or less. In the manufacturing method of the roll of any one of Claims 1-3,
A method for producing a charging roll, wherein an elastic layer made of the conductive rubber material is formed on the core metal.