Apparatus for manufacturing cylindrical member and method of manufacturing cylindrical member

The invention provides an apparatus for manufacturing a cylindrical member comprising a cylindrical core body having an outer peripheral surface with a releasing property, the apparatus comprising: a film-forming device that forms a resin film in a region at a central portion from both ends in the axial direction of the outer peripheral surface of the core body; a judging device that judges the deterioration of the releasing property of regions continuous from the region where the resin film is to be formed in the region at the inner side from both ends in the axial direction of the outer peripheral surface of the core body, before the resin film is formed by the film-forming device; and a control device that controls the film-forming device such that the resin film is formed by exposing regions with an undeteriorated releasing property on both ends in the axial direction of the outer peripheral surface of the core body, in accordance with the results of judgment by the judging device.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2009-073781 filed on Mar. 25, 2009.

BACKGROUND

1. Technical Field

The present invention relates to an apparatus for manufacturing a cylindrical member and a method of manufacturing the cylindrical member.

2. Related Art

In electrophotographic apparatuses such as an electrophotographic image forming apparatus and the like, a number of cylindrical members are used. For example, a charging roll as a charging member, a development roll as a developing device, and a transfer belt and a transfer roll as a transfer device, a fixing roll as a fixing device and the like are used.

If such a cylindrical member has a seam, there may be the case where the deterioration of an image quality to be formed arises, and therefore, seamless members have been preferably used.

SUMMARY

According to an aspect of the invention, there is provided an apparatus for manufacturing a cylindrical member comprising a cylindrical core body having an outer peripheral surface with a releasing property, the apparatus comprising: a film-forming device that forms a resin film in a region at a central portion from both ends in the axial direction of the outer peripheral surface of the core body; a judging device that judges the deterioration of the releasing property of regions continuous from the region where the resin film is to be formed in the region at the inner side from both ends in the axial direction of the outer peripheral surface of the core body, before the resin film is formed by the film-forming device; and a control device that controls the film-forming device such that the resin film is formed by exposing regions with an undeteriorated releasing property on both ends in the axial direction of the outer peripheral surface of the core body, in accordance with the results of judgment by the judging device.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments according to the invention will be described in detail with reference to the drawings.

As shown inFIG. 1, a manufacturing apparatus10for a cylindrical member of the present exemplary embodiment (hereafter, the apparatus is referred to as a “cylindrical member manufacturing apparatus”) is an apparatus for manufacturing a cylindrical member52(refer toFIG. 2D).

The cylindrical member52manufactured by the cylindrical member manufacturing apparatus10is an endless tubular body which is used suitably for the photoreceptor in an electrophotographic copier, a laser beam printer and the like; an intermediate transfer belt, an intermediate transfer body, a conveyer belt, a charging roll, a transfer roll, a development roll and the like; and the material, shape, size and the like thereof can be appropriately selected in accordance with the use, function or the like.

As shown inFIG. 2A, in the cylindrical member manufacturing apparatus10, first, a core body50is prepared, and a releasing agent is coated over the entire outer peripheral surface of the core body to form a releasing layer51, thereby forming a state where the outer peripheral surface of the core body50has a releasing property.

Next, a coating film52A is formed by coating a resin solution onto the outer peripheral surface of the core body50(refer toFIG. 2B). After the coating film52A is formed, the coating film52A is baked at a predetermined baking temperature. As shown inFIG. 2C, air is injected between both ends in the axial direction of the baked coating film52A from an air injection member60to form a clearance between the coating film52A and the outer peripheral surface of the core body50, then the baked coating film52A is released and drawn out from the core body50so that a cylindrical member52is manufactured as shown inFIG. 2D.

Hereinafter, the structure of the cylindrical member manufacturing apparatus10will be described in detail.

The cylindrical member manufacturing apparatus10is constituted by including a cylindrical member manufacturing section20for manufacturing the cylindrical member52and a control section30for controlling the cylindrical member manufacturing section20, as shown inFIG. 1. The cylindrical member manufacturing section20is constituted by including an identification section22, a film-forming section24, a baking section26and a releasing section28. The identification section22, the film-forming section24, the baking section26and the releasing section28are connected to a control section30, respectively, to enable transmission and reception of signals.

Further the cylindrical member manufacturing apparatus10includes an output unit23and an input unit21. The output unit23and the input unit21are also connected to the control section30, respectively, to enable transmission and reception of signals. The output unit23is an output device for displaying information inputted from the control section30to the outside, and examples of the output unit23include a display device such as a CRT and LCD, a printer, and the like. The input unit21is used as a command operation for inputting a variety of information, and examples of the input unit21include a keyboard and the like.

The identification section22is a device which reads identification information for identifying the core body50. The identification section22may be any of identification information-readable devices, and when the display mode of identification information to be identified is a bar code, a bar code reader may be used, and the display mode is characters or numerals, a device having a character-recognizing function and an image pickup element may be used, and the devices may be appropriately selected in accordance with display modes.

As shown inFIG. 3, in the cylindrical member manufacturing apparatus10of the exemplary embodiment, the core body50having a releasing layer51on the surface thereof is secured onto a seat40in an upright state with a securing member (that are not shown in the drawing). In the exemplary embodiment, although the case where three core bodies50are secured onto the seat40is exemplary described, the case is not limited to three core bodies. Further, although drawings are omitted, plural seats40, onto which plural core bodies50are secured, are installed in the cylindrical member manufacturing apparatus10.

Metals such as aluminum, nickel and stainless steel are used for the core body50. In addition, the outer peripheral surface of the core body50is preferably roughened, from the viewpoint of preventing the coating film52A from blistering under the influence of byproducts such as residual solvent or water in the coating film52A when the coating film52A formed on the outer peripheral surface of the core body50is dried.

Specifically, it is desirable that the arithmetic average roughness Ra of the outer peripheral surface is roughened in the range of from 0.2 μm to 2.0 μm. In the case where the outer peripheral surface of the core body50is roughened in the above range, vapor of residual solvent or water generated from the coating film52A when the coating film52A formed on the surface of the core body50is dried and baked, is released from small clearances between the core body50and the coating film52A to the outside. Accordingly occurrence of blisters in the coating film can be prevented.

Examples of methods of the surface roughening of the outer peripheral surface of the core body50include blasting, cutting, sandpapering and the like. In order to make the interior surface of the coating film52A into a spherical convex shape, in particular, it is desirable that the outer peripheral surface of the core body50is blast-processed with the use of spherical grains. The blast processing using spherical grains is a method of spraying grains containing glass, alumina, zirconia or the like having a diameter of about 0.1 mm to about 1 mm onto the core body with compressed air. If amorphous alumina grains (for example, general polishing grains) are used as the grains, since the configuration of the outer peripheral surface of the core body50also becomes amorphous, and in particular, protrusions and recesses with acute angles are easily formed, protrusions and recesses with acute angles are also formed on the inner peripheral surface of the cylindrical member52to be formed, which is not preferable.

The releasing layer51is formed on the outer peripheral surface of the core body50before the core body50is mounted on the seat40of the cylindrical member manufacturing apparatus10. The releasing layer51is formed by applying a releasing agent uniformly over the entire outer peripheral surface of the core body50. Accordingly, the entire region of the outer peripheral surface of the core body50is in a state having a releasing property. Releasing agents having a heat-resistance provided by modifying a silicone-based oil or fluorine-based oil are effective. Further, an aqueous releasing agent formed by dispersing ultrafine particles of a silicone resin in water may be used. The releasing layer51is formed by coating the releasing agent on the outer peripheral surface of the core body50, and allowing a solvent to dry as is, or by further conducting baking after the releasing agent is coated.

The core bodies50having the releasing layer51formed on outer peripheral surface thereof are placed on the seat40, and identification plates22A, on which identification information for identifying each core body50placed on the seat40is recorded, are arranged at positions corresponding to the respective core bodies50. In the exemplary embodiment, a bar code is recorded on the identification plate22A as identification information for identifying each core body50.

Each bar code recorded on the identification plate22A is read by the identification section22arranged at the position corresponding to each plate. In addition, in the exemplary embodiment, when the core body50, on the surface of which the releasing layer51is formed, is mounted on the seat40, the seat40is conveyed by a conveying device (that is not shown in the drawing) to the position where the identification plate22A is read by the identification section22, and the identification information on each core body50is read by the identification section22.

The film-forming section24is a device for forming the coating film52A on the outer peripheral surface of the core body50by applying the resin solution52B to the outer peripheral surface of the core body50, on which the releasing layer51is formed. When the identification information of the core body50mounted on the seat40is read by the identification section22, the core body50, whose identification information has been read, is conveyed to the film-forming section24by a drive mechanism (that is not shown in the drawing). For example, as shown inFIG. 4, each core body50mounted on the seat40is toppled so that the axial direction of the core body50becomes horizontal (pushed down in the direction of Arrow A inFIG. 4), and the core body50is conveyed to the film-forming section24by a drive mechanism (that is not shown in the drawing).

As shown inFIGS. 1,5and6, the film-forming section24is constituted by including a supply unit24C, a rotation drive unit24A which drives rotationally the core body50in the circumferential direction, and a motor24B which moves the supply unit24C in the axial direction of the core body50. The rotation drive unit24A, the motor24B and the supply unit24C are connected to the control section30, respectively, to enable transmission and reception of signals.

As shown inFIGS. 5 and 6, the supply unit24C is a device which supplies a resin solution52B to the outer peripheral surface of the core body50. The resin solution52B stored in a storage unit25B passes through a supply pipe25C, is extruded from an ejection unit25D and then passes through a nozzle2SE, and is thereby supplied to the outer peripheral surface of the core body50. As the supply unit24C, a dispenser may be exemplified.

The resin solution52B is a solution containing a material which constitutes the cylindrical member52to be formed. Examples of the resin solution52B include a polyimide varnish, a polyimide precursor varnish and an inorganic filler-containing varnish formed by containing inorganic filler into the polyimide varnish or the polyimide precursor varnish. When these varnishes are used as a resin solution52B, the cylindrical member52formed from the polyimide resin can be manufactured.

In the exemplary embodiment, although the following explanations will be made in the case where the polyimide resin as the resin solution52B is used, any solutions of constituent materials for forming the cylindrical member52may be used. As the constituent material for forming the cylindrical member52, a thermosetting resin is desirable, and specifically, the polyimide-based resin, a polyamideimide-based resin, a polyester-based resin, a polyamide-based resin, a fluorine-based resin, and the like may be exemplified. In particular, when the cylindrical member52used for an intermediate transfer belt and a transfer convey belt in the image forming apparatus used for the electrophotographic system are manufactured, the polyimide-based resin containing an electroconductive agent (inorganic filler) may be suitably used.

As shown inFIGS. 5 and 6, the core body50is rotatably supported at the axial center thereof in the film-forming section24by bearings (that are not shown in the drawing). An elongated rail34is arranged such that a space is provided between the rail34and the core body50, and the rail34is extended in the axial direction of the core body50in the vicinity of the core body50in a state of being supported in the film-forming section24.

The supply unit24C is supported by a linear guide35movably supported in the longitudinal direction of the rail34through a holder36. The motor24B is installed on the linear guide35. The motor24B is connected to the control section30to enable transmission and reception of signals. The motor24B is driven in accordance with control signals from the control section30, and the supply unit24C is moved by the drive of the motor24B from one end toward the other end in the axial direction of the core body50.

In the exemplary embodiment, a start positioning component34A for positioning the starting position is arranged at one end part of the longitudinal direction of the rail34, and the end positioning component34B for positioning the ending position is arranged at the other end part. In the exemplary embodiment the starting positioning component34A is placed such that the position of a nozzle25E of the supply unit24C is arranged at the position corresponding to the edge of one end in the axial direction of the core body50, when the linear guide35reaches the start positioning component34A. Further, when the linear guide35arrives at the mounting position of the end positioning component34B, the end positioning component34B is placed such that the nozzle25E of the supply unit24C is arranged at the position corresponding to the edge of other end in the axial direction of the core body50.

Accordingly, the supply unit24C is moved from the position corresponding to the edge of one end in the axial direction of the core body50to the position corresponding to the edge of other end in the axial direction of the core body50with the movement of the linear guide35from the start positioning component34A to the position where the end positioning component34B is mounted.

The rotation drive unit24A installed in the film-forming section24transmits a drive force to the rotating shaft of the core body50through a gear32A, gear32B, and gear32C. Accordingly, the core body50rotates in the circumferential direction (direction of Arrow X inFIGS. 5 and 6) by being driven by the rotation drive unit24A with the control by the control section30.

In the film-forming section24constituted in such a way, while the core body50is being rotated by the drive of the rotation drive unit24A in the circumferential direction of the core body50, the resin solution52B is supplied toward the outer peripheral surface of the core body50from the supply unit24C, and the supply unit24C is moved in the axial direction of the core body50(direction of Arrow Y inFIG. 6) by the motor24B and the surface of the supplied resin solution is smoothed with a blade25F which moves together with the supply unit24C. In this way, the resin solution52B is supplied to the outer peripheral surface of the core body50, thereby forming the coating film52A on the outer peripheral surface of the core body50.

In addition, in the film-forming section24, the resin solution52B is not applied to the entire region from one end portion to the other end portion in the axial direction of the outer peripheral surface of the core body50, but rather, the resin solution52B is applied to the region at the central portion from both ends in the axial direction of the core body50, to form the coating film52A.

Specifically, as shown inFIG. 7, the central region50B at the inner side from both end regions50A in the axial direction within the entire outer peripheral surface of the core body50is the region50B where the resin solution52B is coated (hereinafter, referred to as a “film-forming region”), and the coating film52A is formed on the film-forming region50B. Accordingly, in the formation of the coating film52A on the core body50, regions where the coating film52A is not formed exist at both ends in the axial direction of the surface of the core body50. Here, both ends mean portions including the ends of the core body50, and the central portion means the center in the axial direction of the core body (the position at one half of the length of the core body from the end of the core body).

This is because the regions where the coating film52A is not formed at both ends in the axial direction of the core body50are required, since there is a concern that the supplied resin solution52B may drip from the end edges of the core body50if the resin solution52B is supplied to the entire outer peripheral surface of the core body50at the time when the coating film52A is formed, and further, since the formed coating film52A is released from the core body50by introducing air from both ends of the coating film52A when the coating film52A is released from the core body50after the formed coating film52A is dried and baked in a subsequent process step.

In the film-forming section24, for the purpose of preventing liquid-dripping of the coating film59A, the coating film52A is dried by evaporating the solvent to such an extent that liquid-dripping from the coating film52A does not arise, while the core body50having the coating film52A formed thereon is being rotated in the circumferential direction by being driven by the rotation drive unit24A. Incidentally, the drying process may be carried out in the baking section26. In this case, a mechanism may be installed, in which the core body50is rotated in the circumferential direction while the core body50is being held in the horizontal direction in the baking section26.

In the film-forming section24, the core body50, in a state where the coating film52A is formed on the central regions from both ends on the outer peripheral surface in the axial direction, and is dried to such an extent that liquid-dripping does not arise, is secured onto the seat40in the upright state again by being conveyed by a conveying mechanism (that is not shown in the drawing) (refer toFIG. 8). At this time, each core body50is conveyed by the conveyance mechanism (that is not shown in the drawing) such that the core body50is mounted to the position corresponding to the identification plate22A, on which the identification information of each core body50is recorded.

In the baking section26, the core body50formed the coating film52A thereon, in such a state that the coating film52A does not cause liquid-dripping, is secured onto the seat40, and is maintained in the environment of a predetermined baking temperature, thereby baking the coating film52A. The baking condition of the coating film52A in the baking section26is controlled by a baking condition controlling section (hereinafter, referred to as a baking condition control unit)26A. The baking condition control unit26A is connected to the control section30to enable transmission and reception of signals, and the baking environment is conditioned by the baking condition control unit26A by way of the control section30in accordance with the materials and the like of the coating film52A.

The baked coating film52A is removed from the core body50having the coating film52A baked by being maintained in the environment of being heated and baked in the baking section26, in the releasing section28, thereby forming the cylindrical member52. As shown inFIG. 9, air injection members60which blow air at high pressure are arranged in the releasing section28, and the air is injected between both ends of the baked coating film52A and the outer peripheral surface of the core body50, so that the baked coating film52A is released from the core body50.

In the cylindrical member manufacturing apparatus10, the series of processes including the film formation of the coating film52A by coating the resin solution52B in the film-forming section24, the heating and baking in the baking section26, and the release of the baked coating film52A from the core body50in the releasing section28is performed as described in the above, so that the cylindrical body52is manufactured. The series of the processes are repeatedly performed, and the cylindrical bodies52are successively manufactured.

Here, as described above, the releasing layer51has been formed in the outer peripheral surface of the core body50, to impart the releasing property to the outer peripheral surface of the core body50. In the coating film52A which is baked after the coating film52A is formed on the outer peripheral surface of the core body50having an outer peripheral surface with a releasing property, air is injected between both ends of the baked coating film52A and the outer peripheral surface of the core body50, so that the baked coating film52A is easily released from the core body50.

However, in the manufacturing process of the cylindrical member52as described above, the coating film52A is formed in the region at the central portion in the axial direction from both ends of the core body50, from the viewpoint of controlling the releasing property of the cylindrical member52and preventing the resin solution52B from dripping from the ends of the core body50. In the baking section26, the core body50is also maintained in the baking environment in order to bake the coating film52A. Accordingly, the regions of the core body50(regions50A inFIG. 7), where the coating film52A is not formed, are also exposed to an atmosphere at a high temperature together with the coating film52A, and the releasing property of the exposed region50A is more easily deteriorated than that of the region (film-forming region50B) covered with the coating film52A. Therefore, even if air is injected between both ends in the axial direction of the baked coating film52A and the outer peripheral surface of the core body50, there may be cases where the releasing of the baked coating film52A from the core body50becomes difficult due to sticking of the coating film52A to the outer peripheral surface of the core body50, in the case where the releasing property in the regions continuous from the coating film52A is deteriorated.

In addition, in order to recover the releasing property of the outer peripheral surface of the core body50, it is considered that a method may be used, in which the releasing property is recovered by repeatedly applying a releasing agent to the core body50and baking the releasing agent-coated core body50for each predetermined period, but this method requires a great many man-hours for the recovery of the releasing property. Moreover, in order to compensate for the shortage of the core bodies50in the cylindrical member manufacturing apparatus10in such a recovery process of the releasing property, it is required that extra core bodies50be prepared.

Accordingly, in the cylindrical member manufacturing apparatus10according to the exemplary embodiment, when the deterioration of the releasing property in the regions continuous from the region where the coating film52A is to be formed, at both ends in the axial direction of the outer peripheral surface of the core body50is judged in the control section30, the film-forming section24is controlled such that the coating film52A is formed so that regions with an undeteriorated releasing property are exposed on both end portions in the axial direction on the outer peripheral surface of the core body50. According to this control, the coating film52A is formed on the outer peripheral surface of the core body50in the state where regions with an undeteriorated releasing property on both end portions in the axial direction of the core body50are always exposed, so that easy releasing of the baked coating film52A from the core body50can be maintained over a long period of time.

Hereinafter, the control executed in the control section30will be described in detail.

The control section30controls each unit of the cylindrical member manufacturing apparatus10. As described above, the control section30is connected to the identification section22, the rotation drive unit24A, the motor24B, the baking condition control unit26A and the releasing section28to enable transmission and reception of signals. The control section30is constituted by connecting a CPU (central processing unit)30A to a memory30B via a bus.

The memory30B stores beforehand the process routine (refer toFIG. 10), which will be described later, a deterioration judgment table, an information table on the number of times of cylindrical member manufacturing, the starting position information indicating the starting position for coating the resin solution52B, the ending position information indicating the ending position for coating the resin solution52B, and various data, and further, stores various data additionally.

The deterioration judgment table is a table which specifies the criteria of the judgment of the deterioration of the outer peripheral surface of the core body50, and is a table in which information relating to the number of times of cylindrical member manufacturing indicating the number of times cylindrical members have been manufactured on the core body50is correlated beforehand to information indicating the deterioration or information indicating the undeterioration. The number of times cylindrical members have been manufactured on the core body50are counted in such a manner that in the cylindrical member manufacturing apparatus10, one series of processes (hereinafter, referred to as a cylindrical member manufacture process) including the film-forming process of the coating film52A by coating the resin solution52B on the core body50in the film-forming section24, the drying process, the heating and baking in the baking section26, and the removal of the cylindrical member52from the core body50in the releasing section28, is counted as one time.

The deterioration information is information which indicates that the regions continuous from the region where the coating film52A is to be formed, at both ends in the axial direction of the outer peripheral surface of the core body50are in the state of a deteriorated releasing property. The undeterioration information is information which indicates that the regions continuous from the region where the coating film52A is to be formed, at both ends in the axial direction of the outer peripheral surface of the core body50are not in the state of a deteriorated releasing property.

The deterioration information and the undeterioration information are information which is judged as to whether the regions where the coating film52A is not formed on the outer peripheral surface of the core body50, on which the releasing layer51has been formed, are deteriorated, in accordance with the number of times of performing manufacturing processing of the cylindrical member (number of times of cylindrical member manufacturing), and the information can be stored in the deterioration judgment table, in which the judgment results are correlated to the information regarding the number of times of cylindrical member manufacturing beforehand.

The judgment as to whether the outer peripheral surface of the core body is deteriorated or is not deteriorated, for example, may be performed in the following manner. The contact angle of water on the regions where the coating film52A is not formed on the outer peripheral surface of the core body50, on which the releasing layer51has been formed, is measured each time the cylindrical member manufacturing process is performed. When the contact angle of water is 10° or less under the conditions of 25° C. and 50% RH, the releasing property is judged to be in the state of “deterioration”, and when the contact angle exceeds 10°, the releasing property is judged to be in the state of “undeterioration”, and the judgment results are stored in correlation with the processing times information.

In addition, the contact angle of water is obtained in such a manner that after about 31 μl of pure water is dropped onto the surface of the region to be measured of the outer peripheral surface of the core body50in the environment of 25° and 50% RH, with the use of an automatic contact meter DM500 (trade name) manufactured by Kyowa Interface Science Co., Ltd., and the coordinate of one end, the other end and the vertical angle of the water drop at 15 seconds after dropping is image-processed, and the contact angle W of water is obtained based on the calculated diameter (2r) and the height (h) of the water drop from the following equation (in the equation, “r” represents the radius of the water drop);
W=2 tan−1(h/r).

For example, as a deterioration judgment table, the table shown in Table 1 is beforehand stored in the memory30B.

TABLE 1Number of Times of ManufactureDeterioration/of Cylindrical MemberUndeterioration0 to 49Undeteriorated50 or moreDeteriorated

In the exemplary embodiment, it is judged that when the contact angle of water is 10° or less, the releasing property is in a deteriorated state, and when the contact angle of water exceeds 10°, the releasing property is not in a deteriorated state. However, this judgment criteria are based on the contact angle in the case where a polyimide resin coating film is used as the coating film52A, and a material formed from a silicone-based releasing agent or a fluorine-based releasing agent is used as the releasing layer51with a thickness of 0.05 μm (the thickness when the cylindrical member manufacturing process has not yet been carried out) on the core body50. Accordingly the angle for the judgment criteria of the deterioration of the releasing property may be changed in accordance with the constituent material of the coating film52A or the constituent material of the releasing layer51, and is not limited to the angle of 10°.

When the judgment criteria is changed in accordance with the constituent material of the coating film52A or the constituent material of the releasing layer51, the deterioration judgment table may be obtained beforehand and stored in the memory30for each constituent material of the coating film52A or constituent material of the releasing layer51, and information for prompting an operator to input information indicating the material for forming the releasing layer52formed on the outer peripheral surface of the core body50used the material for forming the cylindrical member52, and the constituent material of the coating film52A is displayed on the output unit23to prompt the operator to input the information, prior to the execution of the process routine as shown inFIG. 10. When the information is inputted from the input unit21, the deterioration judgment table corresponding to the information is read, and the read table is used in the process routine as shown inFIG. 10.

The information table of the number of times of the cylindrical member manufacturing is a table in which the identification information for identifying the core body50in correlation with the information of the number of times of the manufacture of the cylindrical member indicating the number of times of the cylindrical member manufacturing is stored. The information of the number of times of the manufacture of the cylindrical member is counted up by the CPU30A, each time the series of the cylindrical member manufacturing processes for manufacturing the core body50corresponding to the information is performed

When the core body50identified by the information corresponding to the information of the number of times of the cylindrical member manufacturing stored in the information table of the number of times of the cylindrical member manufacturing, is subjected to the releasing property recovery process for restoring the releasing property over the entire region of the outer peripheral surface, the number of times of the cylindrical member manufacturing may reset to “0”. For example, the reset of the number of times of the cylindrical member manufacturing may be made to “0” by inputting information by a user, or alternatively, a releasing property recovery mechanism may be installed in the cylindrical member manufacturing apparatus10, separately, and a process, in which the number of times of the cylindrical member manufacturing corresponding to the identification number of the core body50which has been subjected to the releasing property recovery process, is rewritten to “0”, may be executed in the CPU30A.

Examples of the releasing property recovery processes include a process in which a releasing agent is again applied to the outer peripheral surface of the core body50to form a releasing layer51, and the releasing agent-coated core body50is baked.

The starting position information which indicates the starting position for coating the resin solution52B is information for indicating the starting position for coating the resin solution52B onto the core body50. The ending position information which indicates the ending position for coating the resin solution52B is information for indicating the ending position for coating of the resin solution52B onto the core body50. These starting position information and ending position information are stored beforehand in correlation with the identification information for identifying the core body50in the memory30B.

For example, as shown inFIG. 11A, the information which indicates the position of the distance “a” from an end in the axial direction of the core body50is stored beforehand as the coating starting position, and the information which indicates the position of the distance “b” from the end of the axial direction is beforehand stored as the coating ending position.

As described above, the distance “a” and the distance “b” may be determined such that the positions are in the central side positions in the axial direction from both ends of the axial direction of the core body50, so that at least regions, where the coating film52A is not coated, are formed at both end portions in the axial direction of the core body50. The regions may be determined in accordance with the width (length in the axial direction) of the cylindrical member52to be formed, or the length of the core body50in the axial direction.

In addition, the values of the distance “a” and the distance “b” are to be overwritten in the process routine, which will be described later.

In the CPU30A of the control section30, when a command signal for starting the cylindrical member manufacturing process is inputted by the operation of a command button (that is not shown in drawing) by a user after the core body50is mounted to the seat40, the process routine as shown inFIG. 10is executed to proceed to step100.

In the step100, the identification information of the core body50to be subjected to the film-forming process is read. In the step100, the signal indicating the identification information of the core body50inputted from the identification section22, is read, thereby reading the identification information of the core body50to be subjected to the film-forming process.

In the next step102, the information of the number of times of the cylindrical member manufacturing corresponding to the identification information which has been read in the step100is read from the information table of the number of times of the cylindrical member manufacturing stored in the memory30B.

In the next step104, it is judged whether the releasing property in the regions continuous from the film-forming region of the coating film52A to be formed at the inner side from both ends on the outer peripheral surface in the axial direction of the core body50corresponding to the identification information which has been read in the step100is deteriorated, or is not deteriorated. The judgment in the step104is executed to judge as to whether the information which indicates deterioration or undeterioration corresponding to information of the number of times of the cylindrical member manufacturing in the deterioration judgment table stored in the memory20B which has been read in the step102is deterioration information.

For example, when the deterioration judgment table as shown in Table 1 as a deterioration judgment table is specified, it is judged that the releasing property is deteriorated when the information of the number of times of the cylindrical member manufacturing read in the step102is information indicating 50 times, and it is judged that the releasing property is not deteriorated when the information of the number of times of the cylindrical member manufacturing is information indicating 49 times or less.

When the judgment in the step104is negative, namely, when the releasing property in the regions continuous from the film-forming region of the coating film52A to be formed at the inner side from both ends on the outer peripheral surface in the axial direction of the core body50to be processed is undeteriorated, the flow proceeds to step110, which will be described later.

On the other hand, if the judgment in the step104is affirmative, namely, when the releasing property in the regions continuous from the film-forming region of the coating film52A to be formed at the inner side from both ends on the outer peripheral surface in the axial direction of the core body50to be processed is deteriorated, the flow proceeds to step106.

In the step106, the coating starting position and the coating ending position of the resin solution52B on the core body50are changed to the central portion from the previous coating starting position and the previous coating ending position in the axial direction, respectively.

Specifically, in the step106, the starting position information and ending position information corresponding to the identification information which has been read in the step100are read, and the coating starting position and the coating ending position which are indicated by the read starting position information and the read ending position information are changed such that the positions are shifted to the central portion in the axial direction of the core body50from the previous respective positions.

For example, when the starting position information corresponding to the identification information stored in the memory30B which has been read in the step100indicates the position of the distance “a” from the end of the core body50in the axial direction as shown inFIG. 11A, the starting position information is changed such that the coating starting position is “a1” which includes a distance a′ that is shifted from the distance “a” to the central portion in the axial direction of the core body50. Similarly, as shown inFIG. 11A, when the ending position information corresponding to the identification information stored in the memory30B which has been read in the step100indicates the position of the distance “b” from the end of the core body50in the axial direction as shown inFIG. 11A, the ending position information is changed such that the coating starting position is “b1” that is shifted by the distance b′ from the distance “b” to the central portion in the axial direction of the core body50.

In addition, the adjustment distances a′ and b′ may be any distances having regions with the releasing property required for releasing easily the baked coating film52A from the core body50, and may be determined beforehand in accordance with the material of the releasing layer51, or the material of the coating film52A.

In the next step108, the starting position information indicating the coating starting position changed in the step106, and the ending position information indicating the coating ending position changed in the step106are overwritten and stored in the memory30B in correlation with the identification information which has been read in the step100, so that the starting position information and ending position information corresponding to the identification information stored in the memory30B are rewritten, respectively.

In the processes from the step104to the step108, when it is judged that the releasing property in the regions continuous from the film-forming region of the coating film52A at the inner side from both ends on the outer peripheral surface in the axial direction of the core body50is not deteriorated, the supply starting position and supply ending position of the resin solution52B are not changed and are identical to the previous supply starting position and supply ending position of the resin solution52B, respectively.

On the other hand, when it is judged that the releasing property in the regions continuous from the film-forming region of the coating film52A at the inner side from both ends on the outer peripheral surface in the axial direction of the core body50is deteriorated, the supply starting position and supply ending position of the resin solution52B are changed such that the supply starting position and supply ending position of the resin solution52B are shifted to the central portion from the previous supply starting position and the previous supply ending position of the resin solution52B in the axial direction, respectively.

In the next step110, the starting position information and the ending position information indicating the coating starting position and the coating ending position, respectively, corresponding to the identification information which has been read in the step100, are read from the memory30B.

In the next step112, the film-forming starting information command signals including the identification information, the starting position information, the ending position information and the command signal indicating the starting of the film-formation, which have been read in the step110, are outputted to the film-forming section24.

In the film-forming section24which received the film-forming starting information command signals, while the core body50is being rotated by the drive of the rotation drive unit24A in the circumferential direction of the core body50, the resin solution52B is supplied to the outer peripheral surface of the core body50from the supply unit24C, and the supply unit24C is moved in the axial direction of the core body50(direction of Arrow Y inFIG. 6) by the motor24B and the surface of the supplied resin solution is smoothed with the blade25F which moves together with the supply unit24C.

In more detail, the motor24B which receives the starting position information and the ending position information contained in the film-forming starting command signals moves the supply unit24C in the axial direction of the core body50from the film-forming starting position in the starting position information to the film-forming ending position in the ending position information contained in the received film-forming command signals. Further, the rotation drive unit24A which receives the film-forming start command signal initiates the rotation of the core body50in the circumferential direction.

The CPU30A receives the signal indicating that the supply unit24C reaches the film-forming starting position by the drive of the motor24B, and upon receipt of the signal, the CPU30A outputs the signal indicating the supply starting to the supply unit24C. Upon receipt of the signal indicating the supply start, the supply unit24C starts the supply of the resin solution52B by opening a valve (that is not shown in the drawing). Further, the CPU30A receives the signal indicating that the supply unit24C moves and arrives at the film-forming ending position from the film-forming start position by the drive of the motor24B, and upon receipt of the signal, the CPU30A outputs the signal indicating the supply ending to the supply unit24C. The supply unit24C which receives the supply ending signal indicating closes the valve (that is not shown in the drawing) to stop the supply of the resin solution52B.

That is, in the process of the step112, the resin solution52B is applied to the outer peripheral surface of the core body50from the coating starting position to the coating ending position which have been read in the step110, thereby forming the coating film52A.

In the processes from the step104to the step108, when the releasing property in the regions continuous from the film-forming region of the coating film52A to be formed at the inner side from both ends on the outer peripheral surface in the axial direction of the core body50is not deteriorated, the supply starting position and supply ending position of the resin solution52B are not changed and are identical to the previous supply starting position and supply ending position of the resin solution52B, and when the releasing property is deteriorated, the supply starting position and supply ending position of the resin solution52B are changed to the central portion from the previous supply starting position and the previous supply ending position of the resin solution52B in the axial direction, respectively.

Accordingly, in the process of the step112, the coating film52A is formed such that the regions, where the releasing property is not deteriorated, are always exposed in the regions continuous from the coating film52A at the inner side from both ends on the outer peripheral surface in the axial direction of the core body50.

In the next step114, the negative judgment is repeatedly checked until the film-forming process of the coating film52A in the step112is completed, and if the judgment is affirmative, the routine proceeds to step116. In the judgment in the step114, for example, the signal indicating that the supply unit24C is moved and arrives at the film-forming ending position from the film-forming starting position by the drive of the motor24B is received, and upon receipt of the signal, the signal indicating the supply ending is outputted to the supply unit24C, and the affirmative judgment can be made.

In the film-forming section24, the coating film52A is formed in the region of the central portion from both ends of the axial direction on the outer peripheral surface, and the core body50which has been subjected to the drying process as described in the above is in the state where liquid-dripping is not caused, is mounted again onto the seat40(refer toFIG. 8) by a conveyance mechanism (that is not shown in the drawing). At this time, each core body50is conveyed by the conveyance mechanism (that is not shown in the drawing) such that the core body50is mounted to the position corresponding to the identification plate22A, on which the identification information for each core body50is recorded.

In the next step116, baking start signals including the condition signal indicating the baking conditions of the coating film52A and the baking start signal indicating the start of drying and baking are outputted to the baking section26.

The baking condition control unit26A in the baking section26, which has received the baking starting signals, controls the baking conditions for conditioning the baking in accordance with the condition signal contained in the baking starting signals, and the baking of the coating film52A is performed.

In the next step118, the negative judgment is repeatedly checked until the baking of the coating film52A is completed, and if the judgment is affirmative, the routine proceeds to step120. In the judgment in the step118, ending signal indicating the completion of the baking is received, and upon receipt of the ending signal, the affirmative judgment can be made.

In the releasing section28, the baked coating film52A formed by being maintained in the baking environment in the baking section26, is removed from the core body50by injecting air between the core body50and the coating film52A from both ends of the coating film52A, thereby forming a cylindrical body52.

In the next step120, the identification information of the core body50which has been subjected to the series of the processes is read by the identification section22. In the step120, the signal indicating a reading command is outputted to each identification section22prepared at the position corresponding to the identification plate22A installed at the position corresponding to each core body50on the seat40, and the identification information of the core body50is read by receiving the identification information received from each identification section22.

In the next step122, the number of times of the cylindrical member manufacturing corresponding to the identification information which is read from the information table of the number of times of the cylindrical member manufacturing stored in the memory30B is incremented by one.

In the next step124, it is judged as to whether the manufacture process of the cylindrical member is finished, and if the judgment is negative, the flow returns to the step100, and if the judgment is affirmative, the process routine ends. For example, in the step124, the affirmative judgment may be made when the signal indicating the end of process is inputted from the input unit21, or alternatively, the number of times of the manufacture processes of the cylindrical member to be successively manufactured is stored beforehand in the memory30B, and the number of times of the manufacture processes is incremented one by one, each time the process from step100to step122is executed, and the affirmative judgment may be made when the number of times of the manufacture processes thus counted up becomes coincident with the number stored beforehand.

By executing the process routine from the step100to the step124, as shown inFIG. 11A, when the releasing property in the regions continuous from the film-forming region where the coating film52A is to be formed, at both end portions in the axial direction of the outer peripheral surface of the core body50, is not deteriorated, the coating film52A is formed in the predetermined position at the central portion from both ends in the axial direction. When the series of the processes are repeatedly performed, and the releasing property in the regions continuous from the region where the coating film52A is to be formed is deteriorated thereby (refer to the region51A inFIGS. 11A and 11B), the coating starting position and the coating ending position of the coating film52A are changed toward the central portion in the axial direction, respectively, such that the regions where the releasing property is not deteriorated (region51B inFIGS. 11A and 11B) are exposed in the regions continuous from both ends in the axial direction of the coating film52A. For this reason, as shown inFIG. 11B, the coating film52A is formed on the outer peripheral surface of the core body50such that the undeteriorated regions (undeteriorated region51B inFIG. 11) are exposed at both end portions in the axial direction of the core body50.

Further, when the series of the processes are further repeatedly performed, and the releasing property in the regions continuous from the region where the coating film52A is to be formed is deteriorated, the coating starting position and the coating ending position of the coating film52A are further changed to the central portion in the axial direction, respectively, such that the regions where the releasing property is not deteriorated are exposed in the regions continuous from both end portions in the axial direction of the coating film52A. Accordingly, as shown inFIG. 11C, the coating film52A is formed on the outer peripheral surface of the core body50such that the undeteriorated region (undeteriorated region51B inFIG. 11C) becomes in the state where the undeteriorated regions are exposed at both end portions in the axial direction of the core body50.

As described in the above, according to the present exemplary embodiment, the cylindrical member manufacturing apparatus10, when the deterioration of the releasing property of the regions continuous from the region where the coating film52A to be formed at the inner side from both ends in the axial direction on the outer peripheral surface of the core body50is judged, the film-forming section24is controlled such that the coating film52A is formed by exposing the regions having an undeteriorated releasing property on the outer peripheral surface of the core body50at both end portions in the axial direction.

Accordingly, the coating film52A is formed on the outer peripheral surface of the core body50, and the release of the baked coating film52A from the core body50with ease is maintained over a long period of time so that the undeteriorated regions are always exposed at both end portions of the axial direction of the core body50.

EXAMPLES

Hereafter, the invention will be described in detail based on exemplary embodiments and comparative examples. However, the invention is not particularly limited thereto.

As a core body50, the stainless steel pipe having an inner diameter Φ of 278 μm, a length of 980 mm, and a thickness of 5.8 mm is prepared, and the outer peripheral surface of the pipe is subjected to a blast processing to form a surface roughness Ra of 0.45 μm. After the surface of the core body50is degreased, and coated with a mixed solution of a silicone-based releasing agent (SEPACOAT (trade name) manufactured by Shin-Etsu Chemical Co., Ltd.) and heptane, the coated core body is baked at 420° C. for 2 hours. Furthermore, after the core body50is cooled sufficiently, the core body50is coated with the above mixed-solution of the releasing agent and heptane is coated once again, and is baked at 330° C. for one hour. In this manner, a releasing layer51is formed on the outer peripheral surface of the core body50to impart a releasing property, thereby preparing the core body50with the releasing property on the outer peripheral surface thereof.

Using the above core body50, in the cylindrical member manufacturing apparatus10as shown inFIGS. 1,3,5,6,8and9, the process routine as shown inFIG. 10is executed, and the manufacturing process of the cylindrical member is performed.

In addition, in a film-forming section24, a mixed-liquid formed by dispersing carbon powder in an amount of 80 parts by weight in a PI precursor solution (U-IMIDE (trade name) manufactured by Unitika Ltd.) having a viscosity of 50 Pa·s at a temperature of 25° C. is used as a resin solution52B. Further, in the film-forming condition in the film-forming section24, the resin solution52B is supplied from a nozzle having an inner diameter of 2 mm and a length of 10 mm to the outer peripheral surface of the core body50with the use of NEMO Pump (registered trade name, manufactured by HEISHIN Ltd.) as a supply unit24C. Moreover, the revolving speed of the core body50by a rotation drive unit24A is set to 50 rpm, and the moving speed (movement speed in the axial direction of the core body50) of the supply unit24C and the blade25F by a motor24B is set to 135 mm/minute.

Further, the coating starting position and the coating ending position in the film-forming section24are set to a distance of 55 mm and 925 mm, from one end of the core body50, respectively. That is, the distance “a” is set to 55 mm, and the distance “b” is set to 925 mm inFIG. 11A. The starting position information and the ending position information are beforehand stored in a memory30B in correlation with the identification information of the core body50.

In addition, after a coating film52A is formed in the film-forming section24, the core body50is allowed to stand at a temperature of 145° C. for 15 minutes in a heating device, while the core body50in the horizontal state is being rotated at a speed of 10 rpm by the drive of the rotation drive unit24A. Thereafter, the temperature is changed to a temperature of 155° C. to further dry the core body50for 12 minutes. Moreover, in a baking section26, the coating film52A formed from a polyimide resin is baked by heating the core body50at temperatures of 200° C., 250° C., 280° C. and 315° C., respectively, for 30 minutes each, by elevating the temperature stepwise.

Further, as a deterioration judgment table, Table 1 is used.

Furthermore, the distances of the coating starting position and the coating ending position to be shifted in the axial direction to the central portion of the core body50are set to 3 mm, respectively. That is, the distance a′ and the distance b′ inFIG. 11Bare set to 3 mm. The information is beforehand stored in the memory30B.

According to Example 1, the process routine as shown inFIG. 10is executed in the cylindrical member manufacturing apparatus10having the above constitution. A series of manufacturing processes including the film-formation of the coating film52A by coating the resin solution52B in the film-forming section24, the heating and baking process in the baking section26, and the release of the cylindrical member52in the releasing section28is successively performed 135 times. In each of all the cylindrical members52thus manufactured, it is confirmed that the coating film52A is easily released from the core body50.

Comparative Example 1

In the process routine as shown inFIG. 10executed in the cylindrical member manufacturing apparatus10in Example 1, the manufacturing process of the cylindrical member is performed in the same conditions as those of Example 1, except that the process routine steps104-108are not executed by changing the program so as not to change the coating starting position and the coating ending position.

A series of manufacturing processes including the film-formation of the coating film52A by coating the resin solution52B in the film-forming section24, the heating and baking process in the baking section26, and the release of the cylindrical member52in the releasing section28is successively performed 135 times.

In each of the cylindrical members52, it is confirmed that the coating film52A is easily released from the core body50thus manufactured in the processes from one to 49 times. However, in the cylindrical members52manufactured in the processes after 50 times, the coating film52A cannot be released from the core body50due to the sticking of the coating film52A to the outer peripheral surface of the core body50.