Rectifier, coating apparatus, coating method, and method for manufacturing a photoreceptor

Abstract

To provide a straightening device that suppresses a flow from being disordered at a position where fluid flowing along a first guide wall and fluid flowing along a second guide wall are confluent as compared with a case in which a closing end part of a second flow passage on an opposite side from a first flow passage is plane along an axially right-angled plane.SOLUTION: A straightening device has: a first flow passage member 42 which forms an annular first flow passage 43; a second flow passage member 44 which forms a second flow passage 45 connecting with the first flow passage 43 over an entire circumference upstream from the first flow passage 43; an inflow part 46 which is provided to the second flow passage member 44; a first guide wall 50A which is provided circumferentially apart from the inflow part 46 inside the second flow passage 45, and guides coating liquid L flowing in the second flow passage 45 in one circumferential direction to the side of the first flow passage 43; and a second guide wall 50B which is provided circumferentially adjacently to the first guide wall 50A inside the second flow passage 45 to guide the coating liquid L flowing in the second flow passage 45 to the other circumferential direction to the side of the first flow passage 43, and is arranged in a direction crossing the first guide wall 50A.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a rectifying device, a coating device, a coating method, and a method for manufacturing a photoreceptor.

Background Art

[0002] In Patent Document 1 below, in the process of continuously moving a coated object having a cylindrical outer peripheral surface in its longitudinal direction, the periphery is surrounded annularly, and a coating liquid is applied to the outer peripheral surface of the coated object. Further, in an annular coating device having an annular liquid reservoir chamber, a supply port for supplying a coating liquid from the outside to a part of the liquid reservoir chamber, and a slit opening inward of the liquid reservoir chamber, a bypass passage connecting parts of the liquid reservoir chamber is provided, and a coating liquid pressure feeding means is disposed in the middle thereof. A manufacturing apparatus for a photoreceptor is disclosed.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present disclosure is to obtain a rectifying device, a coating device, a coating method, and a method for manufacturing a photoreceptor in which the flow disturbance at the position where the fluid flowing along the first guide wall and the fluid flowing along the second guide wall merge is suppressed as compared with the case where the closed end portion on the opposite side of the first flow path in the second flow path is planar along the plane perpendicular to the axis.

Means for Solving the Problems

[0005] A flow straightening device according to the first embodiment includes: a first flow channel member that forms an annular first flow channel through which fluid flows axially between an inner circumferential wall and an outer circumferential wall; a second flow channel member that is provided upstream of the first flow channel in the direction of fluid flow and forms a second flow channel between the inner circumferential wall and the outer circumferential wall that is connected to the first flow channel over its entire circumference; an inlet provided in the second flow channel member that allows fluid to flow into a portion of the second flow channel in the circumferential direction that is separated from the first flow channel in the axial direction; a first guide wall provided in the second flow channel at a position separated circumferentially from the inlet and that guides fluid flowing in the second flow channel toward one circumferential direction toward the first flow channel; and a second guide wall provided in the second flow channel adjacent to the first guide wall in the circumferential direction and that guides fluid flowing in the second flow channel toward the other circumferential direction toward the first flow channel and is arranged in a direction intersecting the first guide wall.

[0006] The flow straightening device according to the second embodiment is the flow straightening device according to the first embodiment, wherein the angle between the connecting end where the first guide wall and the second guide wall are connected and the line connecting a point on the first guide wall and a point on the second guide wall at 1 / 4 of the height from the connecting end to the lowest end of the inlet is 40° or less.

[0007] The flow straightening device according to the third embodiment is the flow straightening device according to the second embodiment, wherein the angle between the connecting end where the first guide wall and the second guide wall are connected and the line connecting a point on the first guide wall and a point on the second guide wall at 1 / 4 of the height from the connecting end to the lowest end of the inlet is 10° or less.

[0008] The flow straightening device according to the fourth embodiment is a flow straightening device according to any one embodiment from the first to the third embodiment, wherein one inlet is provided, and one first guide wall and one second guide wall are provided, and the fluid flowing in from the inlet and flowing through the second channel toward one direction in the circumferential direction is guided by the first guide wall, and the fluid flowing in from the inlet and flowing through the second channel toward the other direction in the circumferential direction is guided by the second guide wall.

[0009] The flow straightening device according to the fifth embodiment is a flow straightening device according to any one embodiment from the first to the third embodiment, wherein two or more inlet sections are provided, and one first guide wall and one second guide wall are provided for each of the multiple inlet sections, and a fluid flowing in from one adjacent inlet section and flowing through the second flow path toward one circumferential direction is guided by the first guide wall, and a fluid flowing in from another inlet section adjacent to the one inlet section and flowing through the second flow path toward the other circumferential direction is guided by the second guide wall adjacent to the first guide wall.

[0010] The flow straightening device according to the sixth embodiment is a flow straightening device according to any one embodiment from the first to the fifth embodiment, comprising: a cylindrical inner cylinder constituting the inner circumferential wall of the first flow channel member and the second flow channel member; a protruding portion integrally formed on the outer circumferential surface of the inner cylinder, wherein the first guide wall and the second guide wall protrude radially outward from the inner cylinder; and a cylindrical outer cylinder into which the inner cylinder is inserted, the protruding portion contacting the inner circumferential surface, and which constitutes the outer circumferential wall of the first flow channel member and the second flow channel member.

[0011] The flow straightening device according to the seventh embodiment is the flow straightening device according to the sixth embodiment, wherein the outer cylinder is provided with the inlet.

[0012] The coating apparatus according to the eighth embodiment comprises a flow straightening device according to any one of the first to seventh embodiments, wherein the fluid is a coating liquid applied to a cylindrical body, and a coating liquid holding part provided downstream in the flow direction of the coating liquid in the first flow path of the flow straightening device, having an upper opening and a lower opening, and holding the coating liquid, wherein the cylindrical body is passed through the upper opening and the lower opening, and the cylindrical body is moved relative to the outer surface of the cylindrical body by vertically moving it upward, thereby applying the coating liquid to the outer surface of the cylindrical body.

[0013] A coating method according to the ninth embodiment is a coating method for applying a coating liquid using the coating apparatus described in the eighth embodiment, comprising the steps of: introducing the coating liquid from the inlet and guiding the coating liquid flowing in the second channel toward one side in the circumferential direction along the first guide wall toward the first channel side, introducing the coating liquid from the inlet and guiding the coating liquid flowing in the second channel toward the other side in the circumferential direction along the second guide wall toward the first channel side, and supplying the coating liquid that has merged into the first channel to the coating liquid holding section; and moving the cylindrical body relative to the coating liquid holding section upward in the vertical direction, and applying the coating liquid from the coating liquid holding section to the outer surface of the cylindrical body.

[0014] The coating method according to the tenth embodiment is the coating method described in the ninth embodiment, wherein the cylindrical body is a cylindrical member or a cylindrical core material around which an endless belt-like member is wrapped.

[0015] A method for manufacturing a photoreceptor according to the 11th embodiment is a method for manufacturing a photoreceptor using the coating method described in the 9th or 10th embodiment, wherein the cylindrical body is a cylindrical metal member or a cylindrical core material around which an endless belt-shaped metal member is wrapped, and the coating liquid contains a photosensitive material. [Effects of the Invention]

[0016] According to the flow straightening device of the first embodiment, compared to the case where the closing end of the second flow channel opposite to the first flow channel is planar along a plane perpendicular to the axis, turbulence in the fluid flow at the point where the fluid flowing along the first guide wall and the fluid flowing along the second guide wall merge is suppressed.

[0017] In the flow straightening device according to the second embodiment, compared to the case where the angle between the connecting end where the first guide wall and the second guide wall are connected and the line connecting a point on the first guide wall and a point on the second guide wall at 1 / 4 of the height from the connecting end to the lowest end of the inlet is greater than 40°, turbulence in the fluid flow at the point where the fluids merge is suppressed.

[0018] According to the rectifying device according to the third aspect, compared with the case where the angle formed by the connecting end where the first guide inner wall and the second guide inner wall are connected and the line connecting the points on the first guide inner wall and the points on the second guide inner wall at 1 / 4 of the height from the connecting end side to the lowermost end of the inflow portion is greater than 10°, the turbulence of the fluid flow at the position where the fluids merge is suppressed.

[0019] According to the rectifying device according to the fourth aspect, in a configuration where one inflow portion is provided, compared with the case where the closing end portion on the side opposite to the first flow path in the second flow path is planar along the plane perpendicular to the axis, the turbulence of the fluid flow at the position where the fluid flowing along the first guide inner wall and the fluid flowing along the second guide inner wall merge is suppressed.

[0020] According to the rectifying device according to the fifth aspect, in a configuration where two or more inflow portions are provided, compared with the case where the closing end portion on the side opposite to the first flow path in the second flow path is planar along the plane perpendicular to the axis, the turbulence of the fluid flow at the position where the fluid flowing along the first guide inner wall and the fluid flowing along the second guide inner wall merge is suppressed.

[0021] According to the rectifying device according to the sixth aspect, compared with the case where the first guide inner wall and the second guide inner wall are separately formed between the inner cylinder and the outer cylinder, the creation of the rectifying device becomes easier.

[0022] According to the rectifying device according to the seventh aspect, compared with the case where the inflow portion is provided in a portion other than the outer cylinder, the creation of the rectifying device becomes easier.

[0023] According to the coating device according to the eighth aspect, in a configuration provided with a coating liquid holding portion, compared with the case where the closing end portion on the side opposite to the first flow path in the second flow path is planar along the plane perpendicular to the axis, the occurrence of defects in the coating film on the outer peripheral surface of the cylindrical body is suppressed.

[0024] According to the coating method according to the ninth aspect, compared with the case where the closing end portion on the side opposite to the first flow path in the second flow path is planar along the plane perpendicular to the axis, the occurrence of defects in the coating film on the outer peripheral surface of the cylindrical body is suppressed.

[0025] According to the coating method according to the tenth aspect, the occurrence of defects in the coating film of the cylindrical member or endless belt member is suppressed as compared with the case where the closing end portion on the side opposite to the first flow path in the second flow path is planar along the plane perpendicular to the axis.

[0026] According to the method for manufacturing a photoreceptor according to the eleventh aspect, the occurrence of defects in the coating film on the outer peripheral surface of the photoreceptor is suppressed as compared with the case where the closing end portion on the side opposite to the first flow path in the second flow path is planar along the plane perpendicular to the axis.

Brief Description of the Drawings

[0027] [Figure 1] It is a cross-sectional view showing an outline of the overall configuration of a coating device provided with a rectifying device according to the first embodiment. [Figure 2] It is a cross-sectional view showing a partially enlarged state of a coating liquid holding portion used in a coating device provided with a rectifying device according to the first embodiment. [Figure 3] It is an exploded perspective view showing an inner cylinder and an outer cylinder constituting a rectifying device according to the first embodiment. [Figure 4] It is a front view showing the vicinity of a connecting end where a first guide inner wall and a second guide inner wall used in a rectifying device according to the first embodiment are connected. [Figure 5] (A) is a configuration diagram showing a state before inserting a cylindrical body into a coating liquid holding portion of a coating device, (B) is a configuration diagram showing a state where the cylindrical body is inserted into the coating liquid holding portion of the coating device and lowered, and (C) is a configuration diagram showing a state during moving the cylindrical body upward in the vertical direction with respect to the coating liquid holding portion. [Figure 6] (A) is a side view showing a part of a cylindrical body on which a coating film by a coating liquid is formed on the outer peripheral surface of the cylindrical body, and (B) is a cross-sectional view taken along line 5B-5B in (A). [Figure 7] It is a schematic side view showing a rectifying device according to the second embodiment. [Figure 8] It is a cross-sectional view showing a main part of a coating device according to the first comparative example. [Figure 9] In the coating device according to the first comparative example, it is a schematic plan view showing a state where coating liquids merge. [Figure 10] This is a schematic perspective view showing the state in which the coating liquids merge in the coating apparatus according to the first comparative example. [Figure 11] This is a cross-sectional view showing the main part of the coating apparatus according to the second comparative example. [Figure 12] This is a schematic plan view showing the state in which the coating liquids merge in the coating apparatus according to the second comparative example. [Figure 13] This is a schematic perspective view showing the state in which the coating liquids merge in the coating apparatus according to the second comparative example. [Modes for carrying out the invention]

[0028] The following describes embodiments for implementing the technology of this disclosure. In the following description, the direction indicated by the arrow UP as shown in the drawings is considered to be the upper side in the vertical direction of the device.

[0029] [First Embodiment] <Overall configuration of the coating apparatus> Figure 1 shows a cross-sectional view of an example of a coating apparatus 10 equipped with a flow straightening device 40 according to the first embodiment.

[0030] As shown in Figure 1, the coating apparatus 10 is a device for applying a coating liquid L to the outer circumferential surface 100A of a cylindrical body 100. The coating apparatus 10 includes a coating liquid holding section 12 in which the coating liquid L is held, and a flow straightening device 40 positioned upstream of the coating liquid holding section 12 in the flow direction of the coating liquid L to straighten the flow of the coating liquid L. The coating apparatus 10 also includes a container 14 for containing the coating liquid L that has flowed down from the coating liquid holding section 12, and a circulation section 16 for circulating the coating liquid L inside the container 14 back to the coating liquid holding section 12. Furthermore, the coating apparatus 10 includes a cylindrical housing 20 that supports the coating liquid holding section 12. Here, the coating liquid L is an example of a fluid.

[0031] (Cylindrical body) The cylindrical body 100 is, for example, a cylindrical metal member or a cylindrical core material around which an endless belt-shaped metal member is wound. The cylindrical member or endless belt-shaped member constituting the cylindrical body 100 is, for example, a photosensitive substrate for electrophotography. Furthermore, for example, when a photosensitive substrate for electrophotography is used as the cylindrical body 100, the coating liquid L is a liquid containing a photosensitive material. In this embodiment, the coating device 10 applies the coating liquid L to the cylindrical member or endless belt-shaped member constituting the cylindrical body 100. By using a liquid containing a photosensitive material as the coating liquid L, a photosensitive material for electrophotography can be manufactured.

[0032] (Enclosure) As shown in Figure 1, the housing 20 is composed of cylindrical members and is arranged so that its axial direction is vertical. For example, the housing 20 includes a cylindrical portion 20A arranged along the vertical direction.

[0033] The upper end of the cylindrical portion 20A is provided with an upper wall portion 21B that extends radially inward, and a circular opening 21C is formed in the upper wall portion 21B. The inner diameter of the opening 21C is larger than the outer diameter of the cylindrical body 100. The cylindrical body 100 is configured to pass through the opening 21C of the upper wall portion 21B in the axial direction.

[0034] (Coating liquid holding part) As shown in Figures 1 and 2, the coating liquid holding section 12 has the function of holding the coating liquid L supplied from the circulation section 16. The coating liquid holding section 12 is provided continuously above the upper part of the rectifier 40 in the vertical direction. The coating liquid holding section 12 comprises a case 24. The case 24 comprises a cylindrical section 24A, an upper wall section 24B bent radially inward from the upper end of the cylindrical section 24A, and a block section 24C provided on the lower side of the cylindrical section 24A.

[0035] The cylindrical portion 24A is positioned so that its axial direction is vertical. The upper wall portion 24B is provided with a circular upper opening 25 (see Figure 2). The inner diameter of the upper opening 25 is larger than the outer diameter of the cylindrical body 100. The cylindrical body 100 is configured to pass through the upper opening 25 of the upper wall portion 24B in the axial direction.

[0036] The block section 24C is cylindrical and includes a cylindrical wall section 26B located radially inward of the cylindrical section 24A. The wall section 26B of the block section 24C is connected to the inner circumferential wall 40A of the flow straightening device 40, which will be described later. An inclined section 27 is formed on the inner surface of the wall section 26B, which is arranged to have an upward slope toward the radial inward direction. A circular lower opening 28 is provided at the upper end of the inclined section 27. The inner diameter of the lower opening 28 is larger than the outer diameter of the cylindrical body 100. Also, the inner diameter of the lower opening 28 is smaller than the inner diameter of the upper opening 25. The cylindrical body 100 is configured to pass through the lower opening 28 of the wall section 26B in the block section 24C in the axial direction.

[0037] The coating liquid holding section 12 is supported by a support section (not shown) on the upper side in the vertical direction inside the housing 20.

[0038] The case 24 comprises a cylindrical portion 24A, an upper wall portion 24B, and a block portion 24C, with the upper side of the block portion 24C opening radially inward. An installation surface 30 is provided on the upper part of the block portion 24C, and an annular body 32 is arranged on the installation surface 30 so as to be relatively displaceable. The installation surface 30 is planar and arranged along the horizontal direction.

[0039] Inside the case 24, a flow path 34 is provided between the cylindrical portion 24A and the block portion 24C, and between the cylindrical portion 24A and the annular body 32, through which the coating liquid L flows.

[0040] A cylindrical body 100 passes through the upper opening 25 and lower opening 28 of the coating liquid holding section 12, and the cylindrical body 100 is configured to move relative to the coating liquid holding section 12 in the vertical direction (see Figure 9). The mounting surface 30 is positioned in a direction intersecting the direction of relative movement of the cylindrical body 100.

[0041] The inner diameter of the annular body 32 is larger than the outer diameter of the cylindrical body 100. For example, the inner diameter of the annular body 32 is smaller than the inner diameter of the lower opening 28. The annular body 32 is configured such that, when placed on the installation surface 30, the cylindrical body 100 passes through the inside of the annular body 32 in the axial direction. For example, the annular body 32 is placed on the upper installation surface 30 of the block portion 24C with the coating liquid L interposed therebetween. The annular body 32 is movable (slidable in this embodiment) relative to the installation surface 30 with the coating liquid L interposed therebetween. In this embodiment, there is no drive unit to directly drive the annular body 32, and the annular body 32 is configured to autonomously slide relative to the installation surface 30.

[0042] As shown in Figure 2, a slit-shaped discharge section 36 is provided between the upper opening 25 of the upper wall portion 24B of the coating liquid holding section 12 and the annular body 32, extending in the circumferential direction. The coating liquid L is discharged from the discharge section 36. The coating liquid L discharged from the discharge section 36 flows from the upper opening 25 to the upper surface side of the upper wall portion 24B and overflows, and also flows downward between the annular body 32 and the outer circumferential surface 100A of the cylindrical body 100 (see Figure 1). In other words, the annular body 32 is configured such that the coating liquid L held in the coating liquid holding section 12 flows in from above and out from below as the annular body 32 moves relative to the cylindrical body 100.

[0043] In the coating apparatus 10, the coating liquid L is applied to the outer circumferential surface 100A of the cylindrical body 100 by moving the cylindrical body 100 relatively upward in the vertical direction relative to the coating liquid holding section 12 (see Figures 5(B) and 5(C)). In the coating liquid holding section 12, the coating liquid L flows between the outer circumferential surface 100A of the cylindrical body 100 and the inner circumferential surface 32A of the annular body 32, and the pressure of the flowing coating liquid L causes the annular body 32 to be displaced relative to the installation surface 30. At this time, the annular body 32 is displaced relative to the installation surface 30 so that the gap between the outer circumferential surface 100A of the cylindrical body 100 and the inner circumferential surface 32A of the annular body 32 becomes uniform along the circumferential direction.

[0044] As shown in Figure 2, the inner circumferential surface 32A of the annular body 32 is provided with an inclined surface 33A located on the upper side and sloping downward from the upper opening 25 side, and a straight section 33B that is straight along the vertical direction from the lower end of the inclined surface 33A.

[0045] Figure 5 shows an example of a method for applying coating liquid L to the outer surface 100A of a cylindrical body 100 using the coating liquid holding section 12 of the coating device 10. As shown in Figure 5(A), the cylindrical body 100 is inserted axially from above the coating liquid holding section 12 and moved downward (in the direction of arrow A). As shown in Figure 5(B), the cylindrical body 100 is further lowered in the direction of arrow A, and the coating liquid L is supplied to the coating liquid holding section 12 by the circulation section 16 (see Figure 1), thereby filling the space between the annular body 32 of the coating liquid holding section 12 and the outer surface 100A of the cylindrical body 100. When the cylindrical body 100 reaches its lowest point, the upper end of the cylindrical body 100 in the axial direction is positioned opposite the coating liquid holding section 12.

[0046] Subsequently, as shown in Figure 5(C), the cylindrical body 100 is moved upward (in the direction of arrow B) relative to the coating liquid holding section 12. At this time, the coating liquid L is discharged from the discharge section 36 so that it overflows from above the coating liquid holding section 12. As a result, the coating liquid L flows downward from the lower opening 28 and is applied to the outer circumferential surface 100A of the cylindrical body 100, which is located above the upper opening 25, thereby forming a coating film 102 on the outer circumferential surface 100A of the cylindrical body 100 (see Figure 6(B)). Note that Figure 5 is an example of a method for applying the coating liquid L to the outer circumferential surface 100A of the cylindrical body 100, and the application method can be changed.

[0047] As shown in Figure 6(A), during the process of applying the coating liquid L to the outer surface 100A of the cylindrical body 100, the coating liquid L applied to the outer surface 100A of the cylindrical body 100 flows downward along the outer surface 100A of the cylindrical body 100.

[0048] Furthermore, as shown in Figure 1, in the coating apparatus 10, a wall portion 150 is provided below the coating liquid holding portion 12 inside the housing 20. The wall portion 150 has an opening 150A through which the cylindrical body 100 passes. In addition, a hole portion 150B is provided at the diagonal lower end of the wall portion 150, positioned adjacent to the inner wall surface of the housing 20. As a result, the coating liquid L flows down from the hole portion 150B of the wall portion 150 along the inner wall surface of the housing 20, and the coating liquid L is collected in the container 14.

[0049] (Overall configuration of the rectifier) As shown in Figures 1 and 3, the flow straightening device 40 is positioned upstream of the coating liquid holding section 12 in the flow direction of the coating liquid L, and has the function of straightening the flow of the coating liquid L and allowing it to flow into the coating liquid holding section 12. In this embodiment, the flow straightening device 40 is provided continuously with the coating liquid holding section 12 on the lower side in the vertical direction of the coating liquid holding section 12.

[0050] As shown in Figure 3, the flow straightening device 40 comprises a first flow channel member 42 and a second flow channel member 44 provided on the upstream side of the first flow channel member 42 in the flow direction of the coating liquid L. The flow straightening device 40 includes an inlet 46 provided in the second flow channel member 44 into which the coating liquid L flows. The flow straightening device 40 comprises an inner circumferential wall 40A and an outer circumferential wall 40B located outside the inner circumferential wall 40A. Note that the upstream or downstream side in the flow direction of the coating liquid L may be simply referred to as "upstream side" or "downstream side" without specifying "flow direction of the coating liquid L".

[0051] (First flow channel member) As shown in Figure 3, the first flow channel member 42 is positioned on the upper side in the vertical direction, and the upper part of the first flow channel member 42 is connected to the coating liquid holding section 12 (see Figure 1). The upper parts of the inner circumferential wall 40A and the outer circumferential wall 40B constitute a part of the first flow channel member 42. The first flow channel member 42 has an annular first flow channel 43 formed between the inner circumferential wall 40A and the outer circumferential wall 40B, through which the coating liquid L flows in the axial direction. That is, the coating liquid holding section 12 is provided on the downstream side in the flow direction of the coating liquid L in the first flow channel 43 of the first flow channel member 42, and the annular first flow channel 43 and the annular flow channel 34 (see Figure 1) in the coating liquid holding section 12 are connected in the axial direction.

[0052] (Second flow channel member and inflow section) As shown in Figure 3, the second flow channel member 44 is continuously arranged on the lower side in the vertical direction of the first flow channel member 42. That is, the second flow channel member 44 is connected to the lower side in the vertical direction of the first flow channel member 42. The lower sides of the inner circumferential wall 40A and the outer circumferential wall 40B constitute a part of the second flow channel member 44. The second flow channel member 44 is formed between the inner circumferential wall 40A and the outer circumferential wall 40B and includes a second flow channel 45 that is connected to the first flow channel 43 over its entire circumference. The second flow channel 45 is provided on the upstream side of the first flow channel 43 in the flow direction of the coating liquid L.

[0053] The second flow channel member 44 is provided with a projection 48 that protrudes radially outward from the outer surface of the inner circumferential wall 40A. A portion of the projection 48 is located below the inlet 46. The inlet 46 is provided in a portion of the second flow channel 45 that is circumferentially separated from the first flow channel 43 in the axial direction, and the coating liquid L flows into the second flow channel 45 from the inlet 46. As an example, the inlet 46 is a cylindrical tube, and one end of the tube in the axial direction is connected to the outer circumferential wall 40B.

[0054] The second flow channel member 44 includes a bottom wall portion 48A positioned toward one side in the circumferential direction from the inlet portion 46. A second flow channel 45 is formed above the bottom wall portion 48A. In this embodiment, the bottom wall portion 48A is formed on the upper part of the protruding portion 48 and extends radially outward from the inner circumferential wall 40A, forming the bottom of a part of the circumferential direction of the second flow channel 45. The bottom wall portion 48A is positioned to have an upward slope toward one side in the circumferential direction from the inlet portion 46. As an example, the bottom wall portion 48A is formed in a curved shape so as to change the angle of inclination with respect to the horizontal direction. In this embodiment, at least the upper side of the bottom wall portion 48A has an increasing angle of inclination with respect to the horizontal direction as it moves away from the inlet portion 46. As a result, the coating liquid L flowing in from the inlet portion 46 flows through the second flow channel 45 above the bottom wall portion 48A toward one side in the circumferential direction (direction of arrow C1).

[0055] Within the second channel 45, at a position circumferentially away from the inlet 46, is a first guide wall 50A that guides the coating liquid L flowing in one circumferential direction (direction of arrow C1) towards the first channel 43. The first guide wall 50A constitutes a part of the upper end of the bottom wall 48A and is positioned at the downstream end in the flow direction of the coating liquid L.

[0056] The second flow channel member 44 includes a bottom wall portion 48B positioned toward the other circumferential direction from the inlet portion 46, and a second flow channel 45 is formed above the bottom wall portion 48B. In this embodiment, the bottom wall portion 48B is formed on the upper part of the protrusion portion 48 and extends radially outward from the inner circumferential wall 40A, forming the bottom of a part of the second flow channel 45 in the circumferential direction. The bottom wall portion 48B is positioned to have an upward slope toward the other circumferential direction from the inlet portion 46. As an example, the bottom wall portion 48B is formed to be curved so as to change the angle of inclination with respect to the horizontal direction. In this embodiment, at least the upper side of the bottom wall portion 48B has an increasing angle of inclination with respect to the horizontal direction as it moves away from the inlet portion 46. For example, the bottom wall portion 48B is formed to be symmetrical with respect to the bottom wall portion 48A in a direction perpendicular to the axial direction of the flow straightener 40. As a result, the coating liquid L that flows in from the inlet 46 flows through the second channel 45 above the bottom wall 48B in the other direction in the circumferential direction (arrow C2 direction).

[0057] A second guide wall 50B is provided in the second channel 45 at a position circumferentially away from the inlet 46, guiding the coating liquid L flowing in the second channel 45 toward the other circumferential direction (direction of arrow C2) toward the first channel 43. The second guide wall 50B constitutes a part of the upper end of the bottom wall 48B and is located at the downstream end in the flow direction of the coating liquid L. The second guide wall 50B is provided adjacent to the first guide wall 50A in the circumferential direction within the second channel 45. The second guide wall 50B is arranged in a direction intersecting the first guide wall 50A.

[0058] In other words, the flow straightening device 40 has one inlet 46, and one first guide wall 50A and one second guide wall 50B. In the flow straightening device 40, the coating liquid L that flows in from the inlet 46 and flows through the second flow path 45 in one direction in the circumferential direction (arrow C1 direction) is guided to the first guide wall 50A. Also, in the flow straightening device 40, the coating liquid L that flows in from the inlet 46 and flows through the second flow path 45 in the other direction in the circumferential direction (arrow C2 direction) is guided to the second guide wall 50B.

[0059] The downstream ends of the first guide wall 50A and the second guide wall 50B in the flow direction of the coating liquid L are designated as a confluence section 50 where the coating liquid L flows together. The confluence section 50 is provided with a connecting end 50C that connects the first guide wall 50A and the second guide wall 50B. The connecting end 50C has an R shape smaller than R2.5mm (see Figure 4). In the flow straightening device 40, the coating liquid L flowing in one direction in the circumferential direction (arrow C1 direction) through the second flow channel 45 and the coating liquid L flowing in the other direction in the circumferential direction (arrow C2 direction) through the second flow channel 45 merge at the confluence section 50. In this embodiment, when viewed from a direction perpendicular to the axial direction of the flow straightening device 40, the first guide wall 50A and the second guide wall 50B are arranged in intersecting directions and are arranged to be convex upwards. The connecting end 50C is provided at a position 180° from the inlet section 46 in the circumferential direction of the second flow channel member 44.

[0060] As shown in Figure 4, the angle θ is the angle between the connecting end 50C, where the first guide wall 50A and the second guide wall 50B are connected, and the lines 51A and 51B, which connect point X on the first guide wall 50A and point X' on the second guide wall 50B at a position 1 / 4 of the height H from the connecting end 50C to the lowest end of the inlet 46. That is, this angle θ is the angle between the connecting end 50C, where the first guide wall 50A and the second guide wall 50B are connected, and the lines 51A and 51B, which connect point X on the first guide wall 50A and point X' on the second guide wall 50B at a position 1 / 4 of the height H from the connecting end 50C to the lowest end of the inlet 46. In this case, the angle θ is preferably 40° or less, more preferably 30° or less, and even more preferably 10° or less. In this embodiment, the angle θ is set to, for example, 10°.

[0061] As shown in Figure 3, the flow straightening device 40 includes, as an example, a cylindrical inner cylinder 52 that constitutes the inner circumferential wall 40A, and a projection 48 integrally formed on the outer circumferential surface of the inner cylinder 52. Furthermore, the flow straightening device 40 includes a cylindrical outer cylinder 54 into which the inner cylinder 52 is inserted and which constitutes the outer circumferential wall 40B. A first guide wall 50A and a second guide wall 50B are provided on the upper part of the projection 48. That is, the first guide wall 50A and the second guide wall 50B protrude radially outward from the inner cylinder 52. In this embodiment, during the manufacture of the flow straightening device 40, the inner cylinder 52 with the projection 48 integrally formed is inserted into the outer cylinder 54. With the inner cylinder 52 inserted into the outer cylinder 54, the projection 48 comes into contact with the inner circumferential surface of the outer cylinder 54. The flow straightening device 40 is manufactured by joining the outer surface of the projection 48 and the inner surface of the outer cylinder 54. As a result, a first flow path 43 of the first flow path member 42 is formed between the inner cylinder 52 and the outer cylinder 54, and a second flow path 45 of the second flow path member 44 is formed between the inner cylinder 52 and the outer cylinder 54. The flow straightening device 40 includes an inlet 46 formed in the outer cylinder 54. As an example, one end of the cylindrical inlet 46 in the axial direction is connected to the outer cylinder 54.

[0062] (container) As shown in Figure 1, the container 14 is located at the lower part of the housing 20 in the vertical direction. For example, the container 14 is connected to the lower end of the cylindrical portion 20A of the housing 20.

[0063] The container 14 comprises a cylindrical portion 14A connected to the cylindrical portion 20A, and a recess 14B located below the cylindrical portion 14A, with a valley-shaped depression at its bottom. In this embodiment, the bottom surface of the recess 14B is shaped like an inverted cone, with the inner diameter gradually decreasing towards the bottom.

[0064] The recess 14B has a bottom surface that slopes downward from the cylindrical portion 14A towards the radial center, with the center of the recess 14B being the lowest point. The coating liquid L that flows down from the coating liquid holding portion 12 accumulates in the recess 14B of the container 14. For example, the liquid level L1 of the coating liquid L is located on the upper side of the recess 14B.

[0065] (circulation section) As shown in Figure 1, the circulation unit 16 includes a supply pipe 60 that supplies the coating liquid L inside the container 14 to the flow straightening device 40, and a pump 62 provided in the middle of the supply pipe 60. The pump 62 transfers the coating liquid L from the supply pipe 60 from the container 14 side to the flow straightening device 40 side.

[0066] The upstream end 60A of the supply pipe 60 in the direction of the flow of the coating liquid L is connected to the bottom of the container 14. In this embodiment, the upstream end 60A of the supply pipe 60 is connected to the center, which is the lowest part of the recess 14B. The downstream end 60B of the supply pipe 60 in the direction of the flow of the coating liquid L penetrates the housing 20 and is connected to the inlet 46 of the flow straightener 40. As a result, the coating liquid L flowing through the supply pipe 60 is introduced from the inlet 46 into the second flow path 45 inside the flow straightener 40. From the second flow path 45 of the flow straightener 40, it is supplied to the flow path 34 of the coating liquid holding unit 12 via the first flow path 43.

[0067] Furthermore, a viscosity measuring unit 66 for measuring the viscosity of the coating liquid L is provided in the supply pipe 60, downstream of the pump 62 in the flow direction of the coating liquid L. In addition, a filter 68 for removing foreign matter contained in the coating liquid L is provided in the supply pipe 60, upstream of the viscosity measuring unit 66 in the flow direction of the coating liquid L.

[0068] In the coating apparatus 10, the coating liquid L in the container 14 is supplied to the flow straightener 40 through the supply pipe 60 by driving the pump 62 of the circulation unit 16. The flow straightener 40 then supplies the coating liquid L to the coating liquid holding unit 12. In the coating liquid holding unit 12, the coating liquid L is applied to the outer surface 100A of the cylindrical body 100, and the coating liquid L that flows down the outer surface 100A of the cylindrical body 100 is collected in the container 14. The coating liquid L in the container 14 is then supplied to the flow straightener 40 through the supply pipe 60. Thus, the circulation unit 16 ensures that the coating liquid L in the container 14 is circulated to the coating liquid holding unit 12 via the flow straightener 40.

[0069] <Mechanism and Effects> Next, the operation and effects of this embodiment will be described.

[0070] The coating apparatus 10 includes a flow straightening device 40 and a coating liquid holding unit 12 provided on the downstream side in the flow direction of the coating liquid L in the first flow path 43 of the flow straightening device 40. The coating liquid holding unit 12 has an upper opening 25 and a lower opening 28 and holds the coating liquid L. In the coating liquid holding unit 12, a cylindrical body 100 is passed through the upper opening 25 and the lower opening 28, and the coating liquid L is applied to the outer circumferential surface 100A of the cylindrical body 100 by moving the cylindrical body 100 relatively upward in the vertical direction.

[0071] More specifically, as shown in Figure 5(A), the cylindrical body 100 is inserted from above the coating liquid holding section 12 in the direction of arrow A. As shown in Figure 5(B), the cylindrical body 100 is lowered in the direction of arrow A, and the coating liquid L is supplied to the coating liquid holding section 12 by the circulation section 16 (see Figure 1), thereby filling the space between the annular body 32 of the coating liquid holding section 12 and the outer circumferential surface 100A of the cylindrical body 100. Finally, the cylindrical body 100 is brought to the bottom.

[0072] Subsequently, as shown in Figure 5(C), the cylindrical body 100 is moved upward (in the direction of arrow B) relative to the coating liquid holding section 12, and the coating liquid L is discharged from the discharge section 36 so that it overflows from above. As a result, the coating liquid L flows downward from the lower opening 28 and is applied to the outer circumferential surface 100A of the cylindrical body 100, which is located above the upper opening 25. This forms a coating film 102 on the outer circumferential surface 100A of the cylindrical body 100 (see Figure 6(B)).

[0073] Furthermore, the flow straightening device 40 is provided upstream of the coating liquid holding section 12 in the flow direction of the coating liquid L (see Figure 1). As shown in Figure 3, the flow straightening device 40 includes a first flow channel member 42 that forms an annular first flow channel 43 through which the coating liquid L flows axially between an inner circumferential wall 40A and an outer circumferential wall 40B. The flow straightening device 40 also includes a second flow channel member 44 provided upstream of the first flow channel 43 in the flow direction of the coating liquid L. The second flow channel member 44 has a second flow channel 45 formed between the inner circumferential wall 40A and the outer circumferential wall 40B that is connected to the first flow channel 34 over its entire circumference. The second flow channel member 44 also has an inlet 46 that allows the coating liquid L to flow into a portion of the second flow channel 45 in the circumferential direction, away from the first flow channel 43 in the axial direction.

[0074] Furthermore, the flow straightening device 40 includes a first guide wall 50A located circumferentially away from the inlet 46 within the second flow channel 45. The first guide wall 50A guides the coating liquid L flowing in one circumferential direction (direction of arrow C1) through the second flow channel 45 towards the first flow channel 43. In addition, the flow straightening device 40 includes a second guide wall 50B located circumferentially adjacent to the first guide wall 50A within the second flow channel 45, and the second guide wall 50B is arranged in a direction intersecting the first guide wall 50A. The second guide wall 50B guides the coating liquid L flowing in the other circumferential direction (direction of arrow C2) through the second flow channel 45 towards the first flow channel 43.

[0075] In the flow straightening device 40, the first guide wall 50A and the second guide wall 50B are arranged in a direction that intersects with each other. As a result, at the confluence section 50, near the connecting end 50C where the first guide wall 50A and the second guide wall 50B are connected, the coating liquid L flowing along the first guide wall 50A in the direction of arrow C1 and the coating liquid L flowing along the second guide wall 50B in the direction of arrow C2 smoothly merge. That is, the streamlines of the coating liquid L flowing along the first guide wall 50A in the direction of arrow C1 and the streamlines of the coating liquid L flowing along the second guide wall 50B in the direction of arrow C2 merge in a nearly parallel state. Therefore, collisions between the coating liquid L flowing along the first guide wall 50A and the coating liquid L flowing along the second guide wall 50B are suppressed, and the generation of vortices in the coating liquid L in the first flow path 43 downstream of the connecting end 50C is suppressed.

[0076] Therefore, in the flow straightening device 40, compared to the case where the closed end of the second flow path opposite to the first flow path is planar along a plane perpendicular to the axis, turbulence in the flow of the coating liquid L at the point where the coating liquid L flowing along the first guide wall 50A and the coating liquid L flowing along the second guide wall 50B merge is suppressed. Consequently, the flow of the coating liquid L supplied from the flow straightening device 40 to the coating liquid holding unit 12 is stabilized, and variations in the flow velocity of the coating liquid L in the circumferential direction of the discharge unit 36 ​​of the coating liquid holding unit 12 can be suppressed.

[0077] Here, the coating apparatus 200 of the first comparative example will be described using Figures 8 to 10.

[0078] As shown in Figure 8, the coating apparatus 200 includes a coating liquid holding section 202. The coating liquid holding section 202 includes a case 204. The case 204 includes a cylindrical section 24A, an upper wall section 24B, and a block section 24C. Furthermore, the case 204 includes a bottom wall section 204A connecting the lower end of the cylindrical section 24A and the lower end of the block section 24C. Between the cylindrical section 24A and the block section 24C, a flow path 206 is formed around the entire circumference of the cylindrical section 24A, through which the coating liquid L flows in the axial direction. The flow path 206 is located above the bottom wall section 204A.

[0079] Furthermore, a cylindrical inlet 208 into which the coating liquid L flows is connected to a part of the circumferential direction at the lower vertical end of the cylindrical portion 24A. The downstream end of the inlet 208 is connected to the upper side of the bottom wall portion 204A at the lower vertical end of the cylindrical portion 24A. The bottom wall portion 204A is planar and is formed horizontally along the circumferential direction of the cylindrical portion 24A. In the coating apparatus 200, the coating liquid L flows into the flow path 206 from the inlet 208.

[0080] In the coating apparatus 200, a planar bottom wall portion 204A is formed along the circumferential direction of the cylindrical portion 24A at the position where the inlet portion 208 is connected. As a result, as shown in Figures 9 and 10, the coating liquid L flowing from the inlet portion 208 into the flow path 206 flows along the bottom wall portion 204A in one circumferential direction as indicated by arrow D1, and flows along the bottom wall portion 204A in the other circumferential direction as indicated by arrow D2. Therefore, the coating liquid L flowing in the flow path 206 in the direction of arrow D1 and the coating liquid L flowing in the direction of arrow D2 collide at position 210 opposite the inlet portion 208, which can disrupt the flow velocity of the coating liquid L and potentially generate vortices in the coating liquid L. For this reason, there is a concern that particle aggregation may occur in coating liquid L in which particles are dispersed.

[0081] Furthermore, the coating apparatus 220 of the second comparative example will be described using Figures 11 to 13.

[0082] As shown in Figure 11, the coating apparatus 220 includes a coating liquid holding section 222. The coating liquid holding section 222 has two inlet sections 224 and 226 located on opposite sides in the circumferential direction at the lower axial direction of the cylindrical section 24A. The configuration of the coating apparatus 220, other than the inlet sections 224 and 226, is the same as that of the coating apparatus 200.

[0083] In the coating apparatus 220, a planar bottom wall portion 204A is formed along the circumferential direction of the cylindrical portion 24A at the location where the inlets 224 and 226 are connected. As a result, as shown in Figures 12 and 13, the coating liquid L flowing into the flow path 206 from the inlet 224 flows along the bottom wall portion 204A in one circumferential direction as indicated by arrow E1, and the other circumferential direction flows along the bottom wall portion 204A as indicated by arrow E2. Similarly, the coating liquid L flowing into the flow path 206 from the inlet 226 flows along the bottom wall portion 204A in one circumferential direction as indicated by arrow E3, and the other circumferential direction flows along the bottom wall portion 204A as indicated by arrow E4. Therefore, the coating liquid L flowing into the flow path 206 from the inlet 224 and the coating liquid L flowing into the flow path 206 from the inlet 226 collide at two locations 330 and 332 along the circumferential direction of the flow path 206, which can disrupt the flow velocity of the coating liquid L and potentially generate vortices in the coating liquid L. For this reason, there is a concern that particle aggregation may occur in coating liquids L in which particles are dispersed.

[0084] In contrast, in the flow straightening device 40 of this embodiment, the streamlines of the coating liquid L flowing along the first guide wall 50A in the direction of arrow C1 and the streamlines of the coating liquid L flowing along the second guide wall 50B in the direction of arrow C1 merge in a nearly parallel state, thereby suppressing collisions of the coating liquid L. As a result, turbulence in the flow velocity of the coating liquid L is suppressed, and the generation of vortices in the coating liquid L in the first flow path 43 downstream of the connecting end 50C is suppressed. Consequently, even in a coating liquid L in which particles are dispersed, particle aggregation is suppressed.

[0085] Furthermore, in the flow straightening device 40, the angle θ between the connecting end 50C where the first guide wall 50A and the second guide wall 50B are connected, and the lines 51A and 51B connecting point X on the first guide wall 50A and point X' on the second guide wall 50B at a position 1 / 4 of the height H from the connecting end 50C to the lowest end of the inlet 46, is set to 40° or less. Therefore, in the flow straightening device 40, compared to the case where the angle between the connecting end where the first guide wall and the second guide wall are connected, and the lines 51A and 51B connecting point X on the first guide wall and point X' on the second guide wall at a position 1 / 4 of the height H from the connecting end 50C to the lowest end of the inlet 46 is greater than 40°, turbulence in the flow of the coating liquid L at the point where the coating liquid L merges is suppressed.

[0086] Furthermore, in the flow straightening device 40, the angle θ between the connecting end 50C where the first guide wall 50A and the second guide wall 50B are connected, and the lines 51A and 51B connecting point X on the first guide wall 50A and point X' on the second guide wall 50B at a position 1 / 4 of the height H from the connecting end 50C to the lowest end of the inlet 46, is set to 10° or less. Therefore, in the flow straightening device 40, compared to the case where the angle between the connecting end where the first guide wall and the second guide wall are connected, and the lines 51A and 51B connecting point X on the first guide wall and point X' on the second guide wall at a position 1 / 4 of the height H from the connecting end 50C to the lowest end of the inlet 46 is greater than 10°, turbulence in the flow of the coating liquid L at the point where the coating liquid L merges is suppressed.

[0087] Furthermore, the flow straightening device 40 has one inlet 46, and one first guide wall 50A and one second guide wall 50B. In the flow straightening device 40, the coating liquid L that flows in from the inlet 46 and flows in one direction in the circumferential direction (direction of arrow C1) along the second flow path 45 is guided to the first guide wall 50A. Also, in the flow straightening device 40, the coating liquid L that flows in from the inlet 46 and flows in the other direction in the circumferential direction (direction of arrow C2) along the second flow path 45 is guided to the second guide wall 50B. Therefore, in the configuration of the flow straightening device 40 with one inlet, compared to the case where the closed end of the second flow path opposite to the first flow path is planar along a plane perpendicular to the axis, turbulence in the flow of the coating liquid L at the point where the coating liquid L flowing along the first guide wall 50A and the coating liquid L flowing along the second guide wall 50B merge is suppressed.

[0088] Furthermore, the flow straightening device 40 includes a cylindrical inner cylinder 52 that constitutes the inner circumferential wall 40A, a projection 48 integrally formed on the outer circumferential surface of the inner cylinder 52, and a cylindrical outer cylinder 54 into which the inner cylinder 52 is inserted and which constitutes the outer circumferential wall 40B. A first guide wall 50A and a second guide wall 50B are formed on the projection 48, and the first guide wall 50A and the second guide wall 50B protrude radially outward from the inner cylinder 52. When the inner cylinder 52 is inserted into the outer cylinder 54, the projection 48 is in contact with the inner circumferential surface of the outer cylinder 54. For this reason, the flow straightening device 40 is easier to manufacture compared to the case in which the first guide wall and the second guide wall are formed separately between the inner cylinder and the outer cylinder.

[0089] Furthermore, the flow straightening device 40 has an inlet 46 in the outer cylinder 54. Therefore, compared to cases where the inlet is provided in a part other than the outer cylinder, the fabrication of the flow straightening device 40 is easier.

[0090] Furthermore, the coating apparatus 10 includes a flow straightening device 40 and a coating liquid holding unit 12 provided on the downstream side in the flow direction of the coating liquid L in the first flow path 43 of the flow straightening device 40. The coating liquid holding unit 12 applies the coating liquid L to the outer circumferential surface 100A of the cylindrical body 100 by passing a cylindrical body 100 through the upper opening 25 and the lower opening 28 and moving the cylindrical body 100 relatively upward in the vertical direction. In the coating apparatus 10, the flow of the coating liquid L supplied from the flow straightening device 40 to the coating liquid holding unit 12 is stabilized, and variations in the flow velocity of the coating liquid L are suppressed in the circumferential direction of the discharge section 36 of the coating liquid holding unit 12.

[0091] Therefore, in the coating apparatus 10, with a coating liquid holding section, the occurrence of defects in the coating film 102 on the outer surface 100A of the cylindrical body 100 is suppressed compared to the case where the closing end of the second flow channel opposite to the first flow channel is planar along a plane perpendicular to the axis.

[0092] Furthermore, the coating method for applying the coating liquid L using the coating device 10 includes the steps of: introducing the coating liquid L from the inlet 46 and guiding the coating liquid L flowing in the second channel 45 toward one direction in the circumferential direction (arrow C1 direction) along the first guide wall 50A toward the first channel 43 side; introducing the coating liquid L from the inlet 46 and guiding the coating liquid L flowing in the second channel 45 toward the other direction in the circumferential direction (arrow C2 direction) along the second guide wall 50B toward the first channel 43 side; and supplying the coating liquid L that has merged into the first channel 43 to the coating liquid holding unit 12. Furthermore, the coating method for applying the coating liquid L using the coating device 10 also includes the steps of moving the cylindrical body 100 relative to the coating liquid holding unit 12 in the vertical direction upward, and applying the coating liquid L from the coating liquid holding unit 12 to the outer circumferential surface 100A of the cylindrical body 100. Therefore, in this coating method, compared to the case where the closing end of the second channel opposite to the first channel is planar along a plane perpendicular to the axis, the occurrence of defects in the coating film 102 on the outer surface 100A of the cylindrical body 100 is suppressed.

[0093] Furthermore, in the coating method in which the coating liquid is applied using the coating device 10, the cylindrical body 100 is a cylindrical member or a cylindrical core material with an endless belt-shaped member wrapped around it. Therefore, in this coating method, compared to the case where the closing end of the second flow channel opposite to the first flow channel is planar along a plane perpendicular to the axis, the occurrence of defects in the coating film on the outer surface 100A of the cylindrical member or endless belt-shaped member is suppressed.

[0094] Furthermore, in the method for manufacturing a photoreceptor using the above coating method, the cylindrical body 100 is a cylindrical metal member, or a cylindrical core material with an endless belt-shaped metal member wrapped around it, and the coating liquid L contains a photosensitive material. Therefore, according to the method for manufacturing a photoreceptor, the occurrence of defects in the coating film on the outer surface of the photoreceptor is suppressed compared to the case where the closing end of the second channel opposite to the first channel is planar along a plane perpendicular to the axis.

[0095] [Second Embodiment] Next, the rectifier 120 of the second embodiment will be described using Figure 7. Note that components identical to those of the first embodiment described above will be given the same numbers and their descriptions will be omitted.

[0096] As shown in Figure 7, the flow straightening device 120 comprises a first flow channel member 42 and a second flow channel member 122 positioned upstream of the first flow channel member 42 in the flow direction of the coating liquid L. The second flow channel member 122 is provided with two inlet openings 124 and 126 on opposite sides in the circumferential direction of the outer peripheral wall 40B. In the second flow channel member 122, the coating liquid L flows into the second flow channel 45 from the inlet openings 124 and 126. In addition, in the second flow channel member 122, one first guide wall 130A and one second guide wall 130B are provided for each of the multiple (two in this embodiment) inlet openings 124 and 126.

[0097] In other words, a confluence section 130 is provided between the inlet 124 and the inlet 126 in the circumferential direction of the outer peripheral wall 40B. In Figure 7, to make the configuration easier to understand, only the confluence section 130 on the near side of Figure 7 is shown, and the confluence section 130 on the far side of Figure 7 is omitted. The confluence section 130 is provided with a first guide wall 130A that guides the coating liquid L flowing in one direction (arrow C3 direction) of the second flow path 45, and a second guide wall 130B that guides the coating liquid L flowing in the other direction (arrow C4 direction) of the second flow path 45. In the confluence section 130, the first guide wall 130A and the second guide wall 130B are arranged adjacent to each other, and a connecting end 130C is provided to connect the first guide wall 130A and the second guide wall 130B. The second guide wall 130B is arranged in a direction that intersects with the first guide wall 130A. The connecting end 130C is located at a 90° angle from the inlet 124 and inlet 126 in the circumferential direction of the second flow channel member 122.

[0098] The angle θ between the connecting end 130C, where the first guide wall 130A and the second guide wall 130B are connected, and the line connecting a point on the first guide wall 130A and a point on the second guide wall 130B at a position that is 1 / 4 of the height H from the connecting end 130C to the lowest end of the inlet 46, is preferably 40° or less, more preferably 30° or less, and even more preferably 10° or less. In this embodiment, the angle θ is set to, for example, 10°.

[0099] In the second flow channel member 122, the coating liquid L flowing in from one adjacent inlet 124 and flowing in one direction in the circumferential direction (direction of arrow C3) along the second flow channel 45 is guided to the first guide wall 130A. In addition, the coating liquid L flowing in from another inlet 126 adjacent to the inlet 124 and flowing in the other direction in the circumferential direction (direction of arrow C4) along the second flow channel 45 is guided to the second guide wall 130B. The coating liquid L then merges at the connecting end 130C where the first guide wall 130A and the second guide wall 130B are connected. The other configurations of the flow straightener 120 are the same as those of the flow straightener 40 in the first embodiment.

[0100] The rectifier 120 described above can achieve the same operation and effect as the rectifier 40 of the first embodiment by having the same configuration.

[0101] Furthermore, in the flow straightening device 120, the second flow channel member 122 is provided with two inlet sections 124 and 126, and one first guide wall 130A and one second guide wall 130B are provided for each of the two inlet sections 124 and 126. Therefore, in the flow straightening device 120, in a configuration in which two or more inlet sections are provided, compared to the case where the closing end of the second flow channel opposite to the first flow channel is planar along a plane perpendicular to the axis, turbulence in the flow of the coating liquid L at the point where the coating liquid L flowing along the first guide wall 130A and the coating liquid L flowing along the second guide wall 130B merge is suppressed.

[0102] 〔supplementary explanation〕 In the first and second embodiments described above, the configuration of each component constituting the flow straightening device can be changed as long as it can straighten the flow of the coating liquid L. The shapes of the first guide wall and the second guide wall can be changed as long as they intersect. For example, the first guide wall and the second guide wall may be in a straight line. In the first embodiment, the protrusion 48 is provided on the inner cylinder 52, but the protrusion may be provided on the outer cylinder. Also, the protrusion may be a separate component from the inner cylinder and the outer cylinder. Furthermore, there may be a configuration in which three inlet sections are provided, with a merging section provided between each adjacent inlet section.

[0103] In the first and second embodiments described above, the configuration of each member of the coating liquid holding section 12 can be changed as long as it is configured to allow the coating liquid L to be applied to the outer circumferential surface 100A of the cylindrical body 100.

[0104] Although the present invention has been described in detail with respect to specific embodiments, it will be apparent to those skilled in the art that the present invention is not limited to these embodiments, and that various other embodiments are possible within the scope of the present invention. [Examples]

[0105] The coating apparatus and coating method of this disclosure will be described in more detail below with reference to examples, but the coating apparatus and coating method of this disclosure are not limited to the following examples unless they exceed the spirit of the disclosure.

[0106] First, as the first embodiment, the coating liquid L was applied to the outer surface 100A of the cylindrical body 100 by changing the angle of the inclined surface of the annular body with respect to the vertical direction, and the unevenness of the coating film thickness was evaluated.

[0107] [Example 1] <Preparation of coating solution> (Preparation of metal oxide nanoparticles A) 100 parts by weight of zinc oxide (average particle size 70 μm: prototype manufactured by Teika Co., Ltd.) was stirred and mixed with 450 parts by weight of toluene and 50 parts by weight of methanol. 0.25 parts by weight of silane coupling agent (KBM 603: manufactured by Shin-Etsu Chemical Co., Ltd.) was added, and the mixture was dispersed in a sand grinder mill for 1 hour. The toluene was then removed by vacuum distillation, the mixture was baked at 150 °C for 2 hours, cooled to room temperature, and crushed to obtain surface-treated zinc oxide.

[0108] (Preparation of coating solution) 3 parts by weight of metal oxide fine particles A, 6 parts by weight of blocked isocyanate (Sumijule 3175, manufactured by Sumitomo Bayern Urethanes), and 25 parts by weight of methyl ethyl ketone were mixed for 30 minutes. Then, 5 parts by weight of butyral resin (BM-1, manufactured by Sekisui Chemical Co., Ltd.), 3 parts by weight of silicone balls (Tospar 145, manufactured by Toshiba Silicone Co., Ltd.), and 0.01 parts by weight of leveling agent (silicone oil SH29PA, manufactured by Toray Dow Corning Silicone Co., Ltd.) were added to the above mixture, and the mixture was dispersed in a sand mill for 2 hours to obtain coating solution L.

[0109] The viscosity of the above coating liquid L was measured using a "RE500H" type viscometer (manufactured by Tokiki Sangyo Co., Ltd.) with a standard cone (1°34′), at 25℃, and a shear rate of 100s. -1 Under those conditions, the pressure was 100 mPa·s.

[0110] (Application) An aluminum pipe with a diameter of φ84 × 340 mm was used as the cylindrical body 100, and coating was performed using the coating apparatus shown in Figure 1 and the coating liquid L described above. 0.4 L of coating liquid L per minute was continuously circulated and supplied to the coating liquid holding section 12, and another 0.4 L per minute was supplied to the cylindrical body 100 below the upper opening 25. While continuously circulating the coating liquid L, the upper inner surface of the cylindrical body 100 was gripped by a gripping section (not shown), and it was driven through the upper opening 25 provided in the coating liquid holding section from vertically above at a constant speed of 500 mm per minute. By the time the cylindrical body 100 reached its lowest point, the coating liquid L filled the coating liquid holding section 12 and overflowed.

[0111] Next, the cylindrical body 100 was raised at a constant speed of 250 mm per minute to form a coating film 102 on the outer surface 100A of the cylindrical body 100. While the cylindrical body 100 moved up and down in the upper opening 25, the outer surface 100A of the cylindrical body 100 below the upper opening 25 was completely covered by the coating liquid L discharged from the slit-shaped discharge section 36 provided in the upper opening 25, and the coating liquid flowed down from the outer surface 100A of the cylindrical body 100 due to gravity. The sample with the coating liquid L applied to the cylindrical body 100 (with the coating film 102 formed on the outer surface 100A of the cylindrical body 100) was dried with hot air at 170°C for 40 minutes.

[0112] Furthermore, a flow straightening device 40, as shown in Figure 3, was used. The angle θ between the connecting end at the junction of the flow straightening device and the point on the first guide wall and the point on the second guide wall at a position 1 / 4 of the height from the connecting end to the lowest end of the inlet was set to 3°. In the embodiment of this disclosure, the angle θ between the two lines connecting the point on the first guide wall and the point on the second guide wall at a position 1 / 4 of the height H from the connecting end to the lowest end of the inlet is the angle θ between the two lines connecting the point on the first guide wall and the point on the second guide wall at a position 1 / 4 of the height H from the connecting end to the lowest end of the inlet, below the connecting end where the first guide wall and the second guide wall are connected. When the angle θ is set to 3°, the vector direction of the flow velocity of the coating liquid L flowing along the first guide wall is the same as the vector direction of the flow velocity of the coating liquid L flowing along the second guide wall. The impact of the confluence on the coating quality of the outer surface 100A of the cylindrical body 100 was evaluated using an automated surface inspection machine, based on the number of coating defects detected per unit area (detected by differences in coating density). The evaluation results of the coating quality of the outer surface 100A of the cylindrical body 100 are shown in Table 1.

[0113] [Example 2] The angle θ between the connecting end at the confluence of the rectifier and the two lines connecting the point on the first guide wall and the point on the second guide wall was set to 5°, and the coating liquid L was applied in the same manner as in Example 1.

[0114] [Example 3] The angle θ between the connecting end at the confluence of the rectifier and the two lines connecting the point on the first guide wall and the point on the second guide wall was set to 10°, and the coating liquid L was applied in the same manner as in Example 1.

[0115] [Example 4] The angle θ between the connecting end at the confluence of the rectifier and the two lines connecting the point on the first guide wall and the point on the second guide wall was set to 20°, and the coating liquid L was applied in the same manner as in Example 1.

[0116] [Example 5] The angle θ between the connecting end at the confluence of the rectifier and the two lines connecting the point on the first guide wall and the point on the second guide wall was set to 30°, and the coating liquid L was applied in the same manner as in Example 1.

[0117] [Example 6] The angle θ between the connecting end at the confluence of the rectifier and the two lines connecting the point on the first guide wall and the point on the second guide wall was set to 40°, and the coating liquid L was applied in the same manner as in Example 1.

[0118] [Example 7] The angle θ between the connecting end at the confluence of the rectifier and the two lines connecting the point on the first guide wall and the point on the second guide wall was set to 50°, and the coating liquid L was applied in the same manner as in Example 1.

[0119] [Example 8] The angle θ between the connecting end at the confluence of the rectifier and the two lines connecting the point on the first guide wall and the point on the second guide wall was set to 60°, and the coating liquid L was applied in the same manner as in Example 1.

[0120] [Comparative Example 1] As shown in Figure 10, the configuration was made without a rectifier, and the coating liquid L was applied in the same manner as in Example 1 (angle θ could not be measured).

[0121] The number of defects detected in the coating on the outer surface 100A of the cylindrical body 100 was rated as "◎" if it was 1 or less, "〇" if it was 2 to 7, "△" if it was 8 to 35, and "×" if it was 36 or more.

[0122] Table 1 shows the evaluation results of the coating quality on the outer surface 100A of the cylindrical body 100. [Table 1]

[0123] As shown in Table 1, when the angle θ between the connecting end at the junction of the rectifier and the two lines connecting the point on the first guide wall and the point on the second guide wall is 60° or less, it was confirmed that the number of defects detected in the coating on the outer surface 100A of the cylindrical body 100 was lower compared to the configuration without a rectifier in Comparative Example 1. Furthermore, when the angle θ between the connecting end at the junction of the rectifier and the two lines connecting the point on the first guide wall and the point on the second guide wall is 40° or less, it was confirmed that the number of defects detected in the coating on the outer surface 100A of the cylindrical body 100 was considerably lower. [Explanation of symbols]

[0124] 10 Coating device 12 Coating liquid holding section 25 Top opening 28 Lower opening 34 Flow channels 36 Discharge part 40 Rectifier 40A inner peripheral wall 40B outer wall 42 First flow channel member 43 First channel 44 Second flow channel member 45 Second channel 46 Inlet 48 Protrusion 50A First Guide Wall 50B Second Guide Wall 50C connecting end 51A Tangent 51B Tangent line 52 Inner cylinder 54 Outer cylinder 100 Cylinder 100A outer surface 102 Coating film 120 Rectifier 122 Second flow channel member 124 Inlet 126 Inlet 130A First Guide Wall 130B Second Guide Wall 130C connecting end θ angle L coating solution

Claims

1. A first flow channel member comprising an inner circumferential wall and an outer circumferential wall, forming an annular first flow channel through which fluid flows axially between the inner circumferential wall and the outer circumferential wall, A second flow channel member provided upstream of the first flow channel in the fluid flow direction and arranged continuously with the first flow channel member, the second flow channel member being composed of an inner circumferential wall and an outer circumferential wall, and forming a second flow channel between the inner circumferential wall and the outer circumferential wall that connects to the first flow channel over its entire circumference, The second flow channel member includes an inlet that allows fluid to flow into a portion of the second flow channel that is separated from the first flow channel in the axial direction, A first guide wall is provided in the second flow channel member at a position circumferentially away from the inlet within the second flow channel, and guides the fluid flowing in one circumferential direction of the second flow channel toward the first flow channel, A second guide wall is provided within the second flow channel of the second flow channel member adjacent to the first guide wall in the circumferential direction, and guides the fluid flowing in the second flow channel toward the other circumferential direction toward the first flow channel, and is arranged in a direction intersecting the first guide wall, A rectifier having a flow control device.

2. The flow straightening device according to claim 1, wherein the angle between the connecting end where the first guide wall and the second guide wall are connected and the line connecting a point on the first guide wall and a point on the second guide wall at 1 / 4 of the height from the connecting end to the lowest end of the inlet is 40° or less.

3. The flow straightening device according to claim 2, wherein the angle between the connecting end where the first guide wall and the second guide wall are connected and the line connecting a point on the first guide wall and a point on the second guide wall at 1 / 4 of the height from the connecting end to the lowest end of the inlet is 10° or less.

4. The aforementioned inlet is provided as one, and the first guide wall and the second guide wall are each provided as one. The fluid that flows in from the inlet and flows through the second channel toward one direction in the circumferential direction is guided by the first guide wall. The flow straightening device according to any one of claims 1 to 3, wherein the fluid that flows in from the inlet and flows through the second channel toward the other in the circumferential direction is guided by the second guide wall.

5. There are two or more of the aforementioned inflow sections, and one of the first guide wall and one of the second guide wall are provided in each of the multiple aforementioned inflow sections. A fluid flowing in from one of the adjacent inlets and flowing through the second channel toward one direction in the circumferential direction is guided by the first guide wall. A flow straightening device according to any one of claims 1 to 3, wherein a fluid that flows in from one of the inlets adjacent to another inlet and flows through the second flow path toward the other in the circumferential direction is guided by the second guide wall adjacent to the first guide wall.

6. The cylindrical inner cylinder that constitutes the inner circumferential wall of the first flow channel member and the second flow channel member, A protruding portion is integrally formed on the outer circumferential surface of the inner cylinder, and the first guide wall and the second guide wall are configured to protrude radially outward from the inner cylinder, The inner cylinder is inserted into the cylindrical outer cylinder, the protruding portion contacts the inner circumferential surface, and the cylindrical outer cylinder constitutes the outer circumferential wall of the first flow channel member and the second flow channel member. A rectifier according to any one of claims 1 to 5, having the following:

7. The flow straightening device according to claim 6, wherein the outer cylinder is provided with the inlet portion.

8. The fluid is a coating liquid applied to a cylindrical body, as per any one of claims 1 to 7. The rectifier described in section, A coating liquid holding section provided on the downstream side in the flow direction of the coating liquid in the first flow channel of the rectifier, comprising an upper opening and a lower opening, wherein the coating liquid is applied to the outer surface of the cylindrical body by passing the cylindrical body through the upper opening and the lower opening and moving the cylindrical body relatively upward in the vertical direction, A coating apparatus having

9. A coating method comprising applying a coating solution using the coating apparatus described in claim 8, A step of supplying the coating liquid to the coating liquid holding section, which is supplied with the coating liquid that has merged into the first channel, and is supplied to the coating liquid holding section, which is supplied with the coating liquid that has merged into the first channel, and is supplied with the coating liquid that has merged into the first channel, which is supplied with the coating liquid that has merged into the first channel, The process involves moving the cylindrical body relative to the coating liquid holding portion in the vertical direction upward, and applying the coating liquid from the coating liquid holding portion to the outer surface of the cylindrical body. A coating method having

10. The coating method according to claim 9, wherein the cylindrical body is a cylindrical member or a cylindrical core material with an endless belt-shaped member wrapped around it.

11. A method for manufacturing a photoreceptor using the coating method described in claim 9 or claim 10, The cylindrical body is a cylindrical metal member, or a cylindrical core material with an endless belt-like metal member wrapped around it. The coating solution is a method for producing a photoreceptor containing a photosensitive material.

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