Pallet for Cylindrical Body and Method for Manufacturing Photoreceptor Drum

Abstract

To provide a pallet for a cylindrical body capable of reliably holding even a small-diameter cylindrical body in a substantially standing state, and a manufacturing method of a photosensitive drum substrate using the pallet.SOLUTION: A pallet 1 has a placement surface 3 on which a cylindrical body 30 is placed in a standing state, a skewer 5 is provided on the placement surface 3 so as to project upward, and the skewer 5 is inserted into the cylindrical body 30 from a lower end opening 30b to hold the cylindrical body 30 in a substantially standing state. At least one step part 7 is formed on a peripheral surface 6 of the skewer 5 so that the skewer 5 becomes thinner stepwise upward. A step surface 8 of the step part 7 serves as a receiving surface 9 for receiving a lower end of the cylindrical body having an inner diameter smaller than an inner diameter of the cylindrical body 30.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a pallet for a cylindrical body used to hold a cylindrical body such as a photosensitive drum substrate substantially upright during cleaning, drying, etc. of the cylindrical body, and a method for manufacturing a photosensitive drum using the pallet.

Background Art

[0002] When manufacturing a photosensitive drum for an electrophotographic apparatus such as a copying machine, a laser beam printer, or a facsimile apparatus, a plurality of photosensitive drum substrates are transported, cleaned, or dried while being placed upright on a pallet. A plurality of holding members for holding the respective substrates upright are attached to the pallet (see, for example, Patent Documents 1 to 3).

[0003] Generally, photosensitive drums of the same diameter size are mass-produced in order to reduce manufacturing costs and the like. In this case, a pallet corresponding to the substrate size (inner diameter) of the photosensitive drum to be manufactured is used. In this case, in the manufacturing process of the photosensitive drum, when the substrate size of the photosensitive drum to be manufactured is changed, it is necessary to replace the pallet or replace the holding members corresponding to the substrate size on the pallet each time, resulting in poor workability.

[0004] Therefore, in Patent Document 4, a pallet is proposed that has a placement surface on which a photosensitive drum substrate (cylindrical body) is placed, and a plurality of positioning pins that project vertically from this placement surface to hold the substrate, and these positioning pins are arranged on a plurality of concentric circles on the placement surface.

[0005] According to this pallet, when holding a substrate having a predetermined inner diameter upright, a circle corresponding to the inner diameter of the substrate is selected from among the plurality of concentric circles, and the substrate is placed on the placement surface so that the positioning pins arranged on this circle are inserted into the substrate, whereby the substrate is configured to be held upright.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0007] In recent years, the diameter of the photosensitive drum substrate has been decreasing. For example, there are substrates with different diameter sizes, such as a substrate with an outer diameter of φ24 mm (inner diameter of φ22.5 mm) and a substrate with an outer diameter of φ20 mm (inner diameter of φ18.5 mm). In this case, the difference between the inner diameter of the former substrate and the outer diameter of the latter substrate is as small as 2.5 mm (radius difference of 1.25 mm). In order to hold such a substrate upright on the placement surface of the above-mentioned pallet, it is necessary to make the positioning pin thinner, and therefore, the strength of the pin is weak, and it has been difficult to hold the substrate upright.

[0008] The present invention has been made in view of the above-described technical background, and an object thereof is to provide a pallet for a cylindrical body that can surely hold a small-diameter cylindrical body in a substantially upright state, and a method for manufacturing a photosensitive drum substrate using the same.

Means for Solving the Problems

[0009] The present invention provides the following means.

[0010] 1) A pallet for a cylindrical body having a placement surface on which the cylindrical body is placed in a substantially upright state, and a string is provided on the placement surface so as to protrude upward, and the string is inserted into the cylindrical body from its lower end opening and the cylindrical body is held in a substantially upright state, at least one step portion is formed on the peripheral surface of the string so that the string gradually becomes thinner upward, A pallet for a cylindrical body, wherein the stepped surface of the stepped portion serves as a receiving surface for receiving the lower end of a cylindrical body having a smaller inner diameter than the inner diameter of the cylindrical body.

[0011] 2) The pallet for a cylindrical body according to item 1 above, wherein, in the upper part and the lower part adjacent to each other with respect to the height position of the stepped portion in the string, the central axis of the minimum circumscribed circle of the cross section of the upper part is eccentric with respect to the central axis of the minimum circumscribed circle of the cross section of the lower part.

[0012] 3) A guiding portion for guiding the lower end of the cylindrical body downward relative to the string when the string is inserted into the cylindrical body is provided on the peripheral surface of the string, and the pallet for a cylindrical body according to item 1 or 2 above, wherein the guiding portion extends linearly downward from the upper end portion of the peripheral surface of the string to a position lower than the height position of the lowermost step of the at least one-step stepped portion.

[0013] 4) The string includes 3 to 6 blade plate portions that protrude radially outward in the radial direction with respect to the central axis of the string, extend downward from the upper end portion to the lower end portion of the string, and are inserted and arranged in the cylindrical body, and the pallet for a cylindrical body according to any one of items 1 to 3 above, wherein the stepped portion is formed at the outer end of at least one of the 3 to 6 blade plate portions.

[0014] 5) A guiding portion for guiding the lower end of the cylindrical body downward relative to the string when the string is inserted into the cylindrical body is provided on the peripheral surface of the string, and the guiding portion extends linearly downward from the upper end of the peripheral surface of the string to a position lower than the height position of the lowermost step of the at least one-step stepped portion, the string includes 5 blade plate portions that protrude radially outward in the radial direction with respect to the central axis of the string, extend downward from the upper end portion to the lower end portion of the string, and are inserted and arranged in the cylindrical body. Of the five blade plate portions, the outer ends of two blade plate portions serve as the guides, and at least one stepped portion is formed at the outer ends of the remaining three blade plate portions, respectively. The pallet for a cylindrical body according to item 1 or 2 above.

[0015] 6) The pallet for a cylindrical body according to item 5 above, wherein the opening angles between adjacent blade plate portions in the circumferential direction in the remaining three blade plate portions are each in the range of 80° to 110°.

[0016] 7) A method for manufacturing a photosensitive drum, which cleans the photosensitive drum substrate in a state where the photosensitive drum substrate is held substantially upright, Using the pallet for a cylindrical body according to any one of items 1 to 6 above, the string of the pallet is inserted and arranged in the photosensitive drum substrate as a cylindrical body, thereby holding the photosensitive drum substrate substantially upright. A method for manufacturing a photosensitive drum.

[0017] 8) A method for manufacturing a photosensitive drum, which cleans the photosensitive drum substrate in a state where the photosensitive drum substrate is held substantially upright, Using the pallet for a cylindrical body according to any one of items 3, 5, and 6 above, the lower end of the photosensitive drum substrate is relatively lowered with respect to the string along the guide portion of the string so that the string of the pallet is inserted into the photosensitive drum substrate as a cylindrical body, thereby holding the photosensitive drum substrate substantially upright. A method for manufacturing a photosensitive drum.

Advantages of the Invention

[0018] The present invention has the following effects.

[0019] In item 1 above, since the stepped surface of the stepped portion formed on the circumferential surface of the string serves as a receiving surface for receiving the lower end of the cylindrical body with a small inner diameter, even a cylindrical body with a small diameter can be reliably held substantially upright.

[0020] In the second item above, in the upper part and the lower part adjacent to each other with respect to the height position of the stepped portion on the skewer, since the central axis of the minimum circumscribed circle of the cross section of the upper part is eccentric with respect to the central axis of the minimum circumscribed circle of the cross section of the lower part, the stepped surface (receiving surface) of the stepped portion can be widened. Therefore, the lower end of the small-diameter cylindrical body can be stably received by the stepped surface over a long period of time.

[0021] In the third item above, since a guide portion is provided on the peripheral surface of the skewer, when inserting the skewer into the cylindrical body, by relatively lowering the lower end of the cylindrical body along the guide portion with respect to the skewer, it is possible to prevent the problem that the lower end of the cylindrical body is caught by the stepped portion of the skewer, and thereby the holding operation of the cylindrical body can be easily performed.

[0022] In the fourth item above, since the skewer is provided with 3 to 6 blade plate portions, when drying after washing the cylindrical body, the drying air (e.g., hot air, warm air) supplied into the cylindrical body surely passes through the gaps between the blade plate portions from the upper end of the skewer downward, so that the water drainage property with respect to the cleaning liquid adhering to the cylindrical body is high, and the drying time can be shortened.

[0023] In the fifth item above, it has the same effect as the effect of the third item above. Furthermore, since the outer ends of two of the five blade plate portions are respectively used as guide portions, the lower end of the cylindrical body can be stably lowered along the guide portion, and thereby the holding operation of the cylindrical body can be surely and easily performed.

[0024] Furthermore, since stepped portions are respectively formed at the outer ends of the remaining three blade plates, the stability of the small-diameter cylindrical body is high in a state where the lower end of the small-diameter cylindrical body is received by the stepped surface of the stepped portion.

[0025] In the sixth item above, since the opening angles between the blade plates adjacent in the circumferential direction are respectively in the range of 80° to 110°, the stability of the small-diameter cylindrical body and the water drainage property of the cylindrical body can be surely enhanced respectively.

[0026] In the seventh item above, when manufacturing the photosensitive drum, any of the effects of the first to sixth items above can be achieved.

[0027] In the above item 8, when manufacturing the photosensitive drum, any of the effects of the above items 3, 5, and 6 can be achieved.

Brief Explanation of Drawings

[0028]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Best Mode for Carrying Out the Invention

[0029] Some embodiments of the present invention will be described below with reference to the drawings.

[0030] As shown in FIGS. 1 and 2, the pallet 1 for a cylindrical body, which is a pallet for a photosensitive drum substrate according to the first embodiment of the present invention, is a plate-shaped (more specifically, flat plate-shaped) one used for transporting, cleaning, and drying a plurality of cylindrical photosensitive drum substrates 30 as a plurality of cylindrical bodies while holding them upright. The substrate 30 is made of a metal such as aluminum.

[0031] The pallet 1 includes a plate-shaped pallet body 2 having a mounting surface 3 on which the substrate 30 is mounted upright, and a string 5 provided on the mounting surface 3 so as to protrude upward with respect to the mounting surface 3.

[0032] As shown in FIG. 3, the string 5 is inserted and disposed into the substrate 30 from its lower end opening 30b to hold the substrate 30 upright. The mounting surface 3 is horizontally disposed, and in this first embodiment, the mounting surface 3 is formed of the upper surface of the pallet body 2 and is flat. The string 5 is made of a synthetic resin, and the total number of the strings 5 is plural.

[0033] The plurality of substrates 30 described above are collectively cleaned and dried according to a conventional method while being held upright on the pallet 1 (more specifically, the pallet body 2). Thereafter, a predetermined layer such as a photosensitive layer is formed on the outer surface of each substrate 30 to obtain a photosensitive drum.

[0034] The cleaning of the substrate 30 is performed by immersing the substrate 30 in the cleaning liquid 41 in the cleaning tank 40 as shown in FIG. 2 while the substrate 30 is held upright, or by shower cleaning (not shown).

[0035] The drying of the substrate 30 is performed by blowing, for example, drying air (warm air, hot air, etc.) onto the substrate 30 while the substrate 30 is held upright.

[0036] As shown in FIGS. 4 and 5, in a state where the base body 30 is placed upright on the placement surface 3, the string 5 is inserted and disposed in the base body 30, and the lower end 30a of the base body 30 abuts against and is received by the placement surface 3. In this state, the base body 30 is held upright on the placement surface 3.

[0037] In this way, the base body 30 whose lower end 30a abuts against and is received by the placement surface 3 is hereinafter also particularly referred to as the "basic photosensitive drum base body (basic base body) 30". Note that this basic base body 30 corresponds to, for example, a photosensitive drum base body with an outer diameter of φ24 mm (inner diameter of φ22.5 mm).

[0038] Furthermore, as shown in FIGS. 7 and 8, the string 5 is configured to be able to hold upright a photosensitive drum base body 31 having a smaller inner diameter than the inner diameter of the basic base body 30. This base body 31 is hereinafter also particularly referred to as the "small-diameter photosensitive drum base body (small-diameter base body) 31". Note that this small-diameter base body 31 corresponds to, for example, a photosensitive drum base body with an outer diameter of φ20 mm (inner diameter of φ18.5 mm).

[0039] As shown in FIG. 3, at least one stepped portion 7 is formed on the circumferential surface 6 of the string 5 such that the string 5 becomes thinner stepwise in the upward direction. In the first embodiment, the total number of stepped portions 7 is one, and this stepped portion 7 is formed at a substantially intermediate position in the height direction of the string 5 on the circumferential surface 6 of the string 5 (specifically, at a height position between the lower end position and the intermediate position of the string 5).

[0040] Furthermore, as shown in FIG. 5, in the upper portion 5b and the lower portion 5a adjacent to each other with respect to the height position h of the stepped portion 7 in the string 5, the central axis P1 of the minimum circumscribed circle C1 (shown by a two-dot chain line in FIG. 4) of the cross section of the upper portion 5b is eccentric with respect to the central axis P0 of the minimum circumscribed circle C0 (shown by a two-dot chain line in FIG. 4) of the cross section of the lower portion 5a toward the guide portion 10 to be described later.

[0041] The stepped surface 8 of the stepped portion 7 of the string 5 is formed horizontally and flatly, and this stepped surface 8 serves as a receiving surface 9 that receives the lower end 31a of the small-diameter base body 31 so that the small-diameter base body 31 stands upright, as shown in FIGS. 7 and 8. Then, with the string 5 (more specifically, the upper portion 5b of the string 5) inserted and arranged in the small-diameter base body 31, the lower end 31a of the small-diameter base body 31 is received by the stepped surface 8 (receiving surface 9), so that the small-diameter base body 31 is held upright on the stepped surface 8.

[0042] Furthermore, as shown in FIG. 6, on the peripheral surface 6 of the string 5, a guiding portion 10 is formed that slidably guides the lower end 30a of the basic base body 30 downward relative to the string 5 when the string 5 is inserted into the basic base body 30. This guiding portion 10 extends continuously and linearly downward from the upper end of the peripheral surface 6 of the string 5 to a position lower than the height position h of the stepped portion 7. More specifically, it extends continuously and linearly downward from the upper end to the lower end (mounting surface 3) of the peripheral surface 6 of the string 5.

[0043] Also, in the upper portion 5b and the lower portion 5a of the string 5, as described above, the central axis P1 of the upper portion 5b is eccentric toward the guiding portion 10 side with respect to the central axis P0 of the lower portion 5a.

[0044] The configuration of the string 5 of the first embodiment will be described in detail as follows.

[0045] As shown in FIG. 3, the string 5 includes a plurality of blade plate portions 12 that radially project outward from the radius in the direction of the central axis (more specifically, the central axis P0 of the lower portion 5a described above and its extension line) and extend continuously and linearly downward from the upper end to the lower end of the string 5. The thickness of each blade plate portion 12 is substantially constant in the vertical direction.

[0046] These blade plate portions 12 are integrally connected at the position of the central axis P0 of the lower portion 5a of the string 5 and are spaced apart from each other in the circumferential direction of the string 5. Furthermore, these blade plate portions 12 constitute a string body that is inserted and arranged in the basic base body 30 when the basic base body 30 is held upright. That is, the string 5 is composed of these blade plate portions 12, and the peripheral surface 6 of the string 5 is composed of the outer ends 13 (more specifically, the outer end faces) of these blade plate portions 12.

[0047] The total number of the blade plate parts 12 is preferably 3 to 6, and particularly preferably 5 as in the first embodiment. When the total number of the blade plate parts 12 is 3 to 6, when drying after cleaning the basic substrate 30 and the small-diameter substrate 31, the drying air supplied from the upper end opening into the substrate can surely pass downward from the upper end of the gaps between the blade plate parts 12, 12, so that the water drainage property for the cleaning liquid adhering to the substrate is high, and the drying time can be shortened. Particularly when the total number of the blade plate parts 12 is 5 as in the first embodiment, the above-described effect can be surely achieved. The cross-sectional shape of the string 5 is substantially in the shape of a "big" character (see FIG. 4).

[0048] Of the five blade plate parts 12, the outer ends 13, 13 of the two blade plate parts 12A, 12A are the above-described guide parts 10, and extend continuously linearly downward from the upper end to the lower end (mounting surface 3) of each blade plate part 12A.

[0049] The above-described stepped parts 7 are formed at the same height position on the outer ends 13, 13, 13 of the remaining three blade plate parts 12B, 12B, 12B.

[0050] Hereinafter, for convenience of explanation, the blade plate part 12 in which the stepped part 7 is not formed on the outer end 13 (that is, the outer end 13 is the guide part 10) is also referred to as a "non-stepped blade plate part 12A", and the blade plate part 12 in which the stepped part 7 is formed on the outer end 13 is also referred to as a "stepped blade plate part 12B".

[0051] When holding the basic substrate 30 upright using the pallet 1 of the first embodiment, first, as shown in FIG. 3, the basic substrate 30 is disposed substantially vertically above the rod 5 of the pallet 1. Next, as shown in FIG. 6, the lower end 30a of the basic substrate 30 is slid downward relative to the rod 5 along the guide portion 10 so that the rod 5 is inserted into the basic substrate 30 from its lower end opening 30b. Then, when the lower end 30a of the basic substrate 30 abuts against the placement surface 3, the descent of the basic substrate 30 stops. As a result, as shown in FIG. 5, the lower end 30a of the basic substrate 30 is received by the placement surface 3 and the rod 5 is inserted and disposed within the basic substrate 30, whereby the basic substrate 30 is held upright.

[0052] It is preferable to perform such a holding operation of the basic substrate 30 onto the rod 5 with a robot arm that has been pre-taught. By doing so, the holding operation can be performed even more easily.

[0053] When holding the small-diameter substrate 31 upright, similar to the holding operation of the basic substrate 30 described above, first, the small-diameter substrate 31 is disposed substantially vertically above the rod 5 of the pallet 1. Next, the lower end 31a of the small-diameter substrate 31 is slid downward relative to the rod 5 along the guide portion 10 so that the rod 5 is inserted into the small-diameter substrate 31 from its lower end opening. Then, when the lower end 31a of the small-diameter substrate 31 abuts against the step surface 8 (receiving surface 9) of the step portion 7 of the stepped vane plate portion 12B, the descent of the small-diameter substrate 31 stops. As a result, as shown in FIG. 8, the lower end 31a of the small-diameter substrate 31 is received by the step surface 8 and the rod 5 (specifically, the upper portion 5b of the rod 5) is inserted and disposed within the small-diameter substrate 31, whereby the small-diameter substrate 31 is held upright.

[0054] According to the pallet 1 of the first embodiment, since the step surface 8 of the step portion 7 formed on the peripheral surface 6 of the rod 5 serves as the receiving surface 9 for receiving the lower end 31a of the small-diameter substrate 31, the small-diameter substrate 31 can also be surely held upright.

[0055] Furthermore, since the string 5 is provided with 3 to 6 blade plate portions 12, when drying after cleaning the basic base 30 and the small-diameter base 31, the drying air supplied into the base from its upper end opening can surely pass downward through the gaps between the respective blade plate portions 12 from the upper end of the string 5. Therefore, the water drainage property with respect to the cleaning liquid adhering to the base is high, and the drying time can be shortened.

[0056] Furthermore, since the total number of the stepped blade plate portions 12B of the string 5 is 3 as described above, the stability of the small-diameter base 31 is high in a state where the lower end 31a of the small-diameter base 31 is received by the step surface 8 of the step portion 7, and the water drainage property with respect to the cleaning liquid adhering to the base can be surely enhanced.

[0057] In these stepped blade plate portions 12B, as shown in FIG. 4, the opening angle α between the stepped blade plate portions 12B, 12B adjacent to each other in the circumferential direction of the string 5 is preferably in the range of 80° to 110°. In this case, the stability of the small-diameter base 31 and the water drainage property of the base can be surely enhanced respectively. In the first embodiment, the opening angle α is, for example, 90°.

[0058] Moreover, since the outer end 13 of the non-stepped blade plate portion 12A of the string 5 is the guide portion 10, when inserting the string 5 into the basic base 30, by relatively lowering the lower end 30a of the basic base 30 along the guide portion 10 with respect to the string 5, it is possible to prevent the lower end 30a of the basic base 30 from being caught by the step portion 7 of the string 5, and thereby the holding operation of the basic base 30 can be easily performed.

[0059] Furthermore, since the total number of the non-stepped blade plate portions 12A is 2, and the outer ends 13, 13 of both non-stepped blade plate portions 12A, 12A are the guide portions 10, the lower end 30a of the basic base 30 can be stably lowered along the guide portion 10, and thereby the holding operation of the basic base 30 can be surely and easily performed. The preferable opening angle β between both non-stepped blade plate portions 12A, 12A is in the range of 60° to 110°.

[0060] Furthermore, the pallet 1 of the first embodiment has the following advantages. This will be described below with reference to FIGS. 9 and 10.

[0061] Reference numeral "5" in FIG. 9 is the string of the pallet of the first embodiment. Reference numeral "5B" in FIG. 10 is a deformed form of the string 5 of the pallet of the first embodiment. In this string 5B, with respect to the height position h of the stepped portion 7 in the string 5B, in the upper portion 5b and the lower portion 5a adjacent to each other, the central axis P1 of the minimum circumscribed circle of the cross section of the upper portion 5b is coaxial with the central axis P0 of the minimum circumscribed circle of the cross section of the lower portion 5a. In this case, the widths of the stepped surfaces 8 of the stepped portions 7 on both sides with respect to the central axis P0 are the same as each other.

[0062] On the other hand, in the string 5 of the pallet of the first embodiment as shown in FIG. 9, since the central axis P1 of the upper portion 5b is eccentric with respect to the central axis P0 of the lower portion 5b as described above, the stepped surface 8 of the stepped portion 7 can be made wider than the stepped surface 8 (one side) of the deformed string 5B.

[0063] Therefore, when the pallet is repeatedly used, in the string 5B of the deformed form (FIG. 10), the stepped surface 8 wears (the worn portion 15) so that the corners of the stepped portions 7 on both sides become round, and thus the stability of the small-diameter base body 31 is likely to be impaired. On the other hand, in the string 5 of the first embodiment (FIG. 9), the stepped surface 8 of the stepped portion 7 wears (the worn portion thereof) so as to be recessed in a substantially circular arc shape in cross section. Therefore, the lower end 31a of the small-diameter base body 31 can be stably received by the stepped surface 8 over a long period of time.

[0064] FIGS. 11 and 12 are views for explaining a pallet 1A for a photosensitive drum base according to the second embodiment of the present invention. In these figures, elements of the pallet 1A of the second embodiment that have the same functions as the elements of the pallet 1 of the first embodiment are given the same reference numerals as the elements of the pallet 1 of the first embodiment. Hereinafter, the second embodiment will be described mainly focusing on the differences from the first embodiment.

[0065] In the pallet 1A of the second embodiment, two stepped portions 7a and 7b are formed on the peripheral surface 6 of the skewer 5A such that the skewer 5A becomes gradually thinner upward. Specifically, among the five blade plate portions 12 constituting the skewer 5A, the outer ends 13 and 13 of the two non-stepped blade plate portions 12A and 12A are guide portions 10. That is, the outer ends 13 and 13 (guide portions 10) of the two non-stepped blade plate portions 12A and 12A continuously extend linearly downward from their upper ends to positions lower than the height position h of the first stepped portion 7a from the bottom among the two stepped portions 7a and 7b. Specifically, they continuously extend linearly downward from their upper ends to the lower ends (placement surface 3). The above-described two stepped portions 7a and 7b are formed on the outer ends 13, 13, and 13 of the remaining three stepped blade plate portions 12B, 12B, and 12B.

[0066] Hereinafter, for convenience of explanation, in the two stepped portions 7a and 7b, the first stepped portion 7a from the bottom is referred to as the "first stepped portion 7a", and the second stepped portion 7b is referred to as the "second stepped portion 7b".

[0067] Similar to the pallet 1 of the first embodiment, the stepped surface 8a of the first stepped portion 7a is a receiving surface 9 that receives the lower end 31a of the photosensitive drum substrate 31 (see FIGS. 7 and 8) having a smaller inner diameter than the inner diameter of the basic substrate 30 so that the smaller-diameter substrate 31 stands upright. This smaller-diameter substrate 31 is also particularly referred to as the "first smaller-diameter photosensitive drum substrate (first smaller-diameter substrate) 31".

[0068] As shown in FIG. 12, the stepped surface 8a of the second stepped portion 7b is a receiving surface 9 that receives the lower end 32a of the photosensitive drum substrate 32 having a smaller inner diameter than the inner diameter of the first smaller-diameter substrate 31 so that the smaller-diameter substrate 32 stands upright. This smaller-diameter substrate 32 is also particularly referred to as the "second smaller-diameter photosensitive drum substrate (second smaller-diameter substrate) 32".

[0069] In the upper portion 5b and the lower portion 5a adjacent to each other with respect to the height position h1 of the first stepped portion 7a in the skewer 5A, similar to the pallet 1 of the first embodiment, the central axis P1 of the minimum circumscribed circle of the cross section of the upper portion 5b is eccentric toward the guide portion 10 with respect to the central axis P0 of the minimum circumscribed circle of the cross section of the lower portion 5a.

[0070] Furthermore, in the upper part 5c and the lower part 5b adjacent to each other with respect to the height position h2 of the second step portion 7b in the string 5A, the central axis P2 of the minimum circumscribed circle of the cross section of the upper part 5c is eccentric toward the guide portion 10 with respect to the central axis P1 of the minimum circumscribed circle of the cross section of the lower part 5b.

[0071] When holding the first small-diameter base body 31 upright using the pallet 1A of the second embodiment, the lower end 31a of the first small-diameter base body 31 is received by the step surface 8a of the first step portion 7a in the same manner as the holding operation of the small-diameter base body 31 described above in the first embodiment, whereby the first small-diameter base body 31 is held upright.

[0072] When holding the second small-diameter base body 32 upright, similar to the holding operation of the small-diameter base body 31 described above in the first embodiment, first, the second small-diameter base body 32 is disposed substantially vertically above the string 5A of the pallet 1A, and then the lower end 32a of the second small-diameter base body 32 is slid downward relative to the string 5A along the guide portion 10 so that the string 5A is inserted into the second small-diameter base body 32 from its lower end opening. Then, when the lower end 32a of the second small-diameter base body 32 abuts against the step surface 8b of the second step portion 7b of the stepped vane plate portion 12B, the descent of the second small-diameter base body 32 is stopped. As a result, as shown in FIG. 12, the lower end 32a of the second small-diameter base body 32 is received by the step surface 8b of the second step portion 7b and the string 5A (specifically, the upper part 5c of the string 5A) is inserted and disposed in the second small-diameter base body 32, so that the second small-diameter base body 32 is held upright.

[0073] According to the pallet 1A of the second embodiment, not only can the basic base body 30 be held upright, but also two types of small-diameter base bodies (the first and second small-diameter base bodies 31 and 32) having a smaller inner diameter than the inner diameter of the basic base body 30 and different inner diameters from each other can be held upright.

[0074] Here, in the present invention, the total number of steps 7 formed on the peripheral surface 6 of the skewer 5 is not limited to one step (first embodiment) or two steps (second embodiment), and may be, for example, three steps. In this case, three types of small-diameter substrates with diameters smaller than the inner diameter of the basic substrate 30 and different from each other in inner diameter can be held upright.

[0075] That is, among the three steps, the step surface of the first step from the bottom (referred to as the "first step") is a receiving surface that receives the lower end of the small-diameter substrate with the largest first inner diameter among the three types of small-diameter substrates, and the step surface of the second step from the bottom (referred to as the "second step") is a receiving surface that receives the lower end of the small-diameter substrate with the second largest inner diameter, and the step surface of the third step from the bottom (referred to as the "second step") is a receiving surface that receives the lower end of the small-diameter substrate with the third largest inner diameter.

[0076] Furthermore, the total number of steps 7 may be four or more. In this case, four or more types of small-diameter substrates with different inner diameters from each other can be held upright.

[0077] Generally, when the total number of steps 7 is one step, the step surface 8 of the step 7 is a receiving surface 9 that receives the lower end 31a of the small-diameter substrate 31 with a diameter smaller than the inner diameter of the basic substrate 30 and of one type in terms of inner diameter size. Furthermore, when the total number of steps 7 is a plurality of steps, when the total number of steps 7 is N (where 2 ≤ N, N is a natural number), and the nth step 7 from the bottom (where 2 ≤ n ≤ N, n is a natural number) is the nth step, the step surface of the nth step is a receiving surface that receives the lower end of the small-diameter substrate with the nth largest inner diameter among the N types of small-diameter substrates with different inner diameters.

[0078] Although some embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be variously modified without departing from the gist of the present invention.

[0079] Also, in the above embodiments, the cylindrical body is a photosensitive drum substrate, but in the present invention, the cylindrical body is not limited to being a photosensitive drum substrate, and it may be a cylindrical object other than the photosensitive drum substrate.

[0080] In addition, in the above embodiment, the placement surface 3 is formed by the upper surface of the plate-shaped pallet body 2. However, in the present invention, for example, a placement table for a basic cylindrical body (not shown) may be installed on the upper surface of the pallet body 2, and the placement surface 3 may be formed by the upper surface of this placement table.

Industrial Applicability

[0081] The present invention can be used for a pallet for a cylindrical body used to hold the cylindrical body in a substantially upright state during cleaning, drying, etc. of a cylindrical body such as a photosensitive drum substrate, and a method for manufacturing a photosensitive drum.

Explanation of Signs

[0082] 1: Pallet 3: Placement surface 5: Rod 6: Peripheral surface of the rod 7: Step portion 8: Step surface 9: Receiving surface 10: Guide 12: Blade plate portion 12A: Blade plate portion without steps 12B: Blade plate portion with steps 13: Outer end of the blade plate portion 30: Basic photosensitive drum substrate 31: First small-diameter photosensitive drum substrate 32: Second small-diameter photosensitive drum substrate

Claims

1. A pallet for a cylindrical body having a placement surface on which the cylindrical body is placed in a substantially upright state, and skewers are provided on the placement surface so as to protrude upward. The skewers are inserted into the cylindrical body from its lower end opening and hold the cylindrical body in a substantially upright state. The pallet for a cylindrical body is characterized in that: At least one stepped portion is formed on the circumferential surface of the skewer so that the skewer becomes gradually thinner upward. The stepped surface of the stepped portion serves as a receiving surface for receiving the lower end of a cylindrical body having a smaller inner diameter than the inner diameter of the cylindrical body. A pallet for a cylindrical body, wherein the central axis of the minimum circumscribed circle of the upper part and the lower part adjacent to each other with respect to the height position of the stepped portion in the skewer is eccentric with respect to the central axis of the minimum circumscribed circle of the lower part.

2. A guiding portion is provided on the circumferential surface of the skewer to guide the lower end of the cylindrical body downward relative to the skewer when the skewer is inserted into the cylindrical body. The guiding portion linearly extends downward from the upper end portion of the circumferential surface of the skewer to a position lower than the height position of the lowermost stepped portion among the at least one stepped portion, according to Claim 1 of the pallet for a cylindrical body.

3. A pallet for a cylindrical body having a placement surface on which the cylindrical body is placed in a substantially upright state, and skewers are provided on the placement surface so as to protrude upward. The skewers are inserted into the cylindrical body from its lower end opening and hold the cylindrical body in a substantially upright state. The pallet for a cylindrical body is characterized in that: At least one stepped portion is formed on the circumferential surface of the skewer so that the skewer becomes gradually thinner upward. The stepped surface of the stepped portion serves as a receiving surface for receiving the lower end of a cylindrical body having a smaller inner diameter than the inner diameter of the cylindrical body. A guiding portion is provided on the circumferential surface of the skewer to guide the lower end of the cylindrical body downward relative to the skewer when the skewer is inserted into the cylindrical body. The guiding portion linearly extends downward from the upper end portion of the circumferential surface of the skewer to a position lower than the height position of the lowermost stepped portion among the at least one stepped portion, according to Claim 1 of the pallet for a cylindrical body.

4. The skewer includes 3 to 6 blade plate portions that radially protrude radially outward with respect to the central axis of the skewer, extend downward from the upper end portion to the lower end portion of the skewer, and are inserted and arranged in the cylindrical body. The pallet for a cylindrical body according to any one of Claims 1 to 3, wherein the stepped portion is formed at the outer end of at least one of the 3 to 6 blade plate portions.

5. A pallet for a cylindrical body, having a placement surface on which the cylindrical body is placed in a substantially upright state, with skewers provided in an upwardly protruding manner on the placement surface, and the skewers being inserted into the cylindrical body from its lower end opening and holding the cylindrical body in a substantially upright state, At least one stepped portion is formed on the peripheral surface of the skewer such that the skewer becomes gradually thinner upward. The stepped surface of the stepped portion serves as a receiving surface for receiving the lower end of a cylindrical body having a smaller inner diameter than the inner diameter of the cylindrical body. The skewer includes 3 to 6 blade plate portions that protrude radially outward with respect to the central axis of the skewer, extend downward from the upper end portion to the lower end portion of the skewer, and are inserted and arranged in the cylindrical body. A pallet for a cylindrical body, in which the stepped portion is formed at the outer end of at least one of the 3 to 6 blade plate portions.

6. A guiding portion is provided on the peripheral surface of the skewer to guide the lower end of the cylindrical body downward relative to the skewer when the skewer is inserted into the cylindrical body, The guiding portion extends linearly downward from the upper end of the peripheral surface of the skewer to a position lower than the height position of the lowermost stepped portion among the at least one stepped portion. The skewer includes 5 blade plate portions that protrude radially outward with respect to the central axis of the skewer, extend downward from the upper end portion to the lower end portion of the skewer, and are inserted and arranged in the cylindrical body. The pallet for a cylindrical body according to claim 1, wherein the outer ends of 2 of the 5 blade plate portions serve as the guiding portion, and the stepped portion of at least one step is formed at the outer ends of the remaining 3 blade plate portions respectively.

7. A pallet for a cylindrical body, having a placement surface on which the cylindrical body is placed in a substantially upright state, with skewers provided in an upwardly protruding manner on the placement surface, and the skewers being inserted into the cylindrical body from its lower end opening and holding the cylindrical body in a substantially upright state, At least one stepped portion is formed on the peripheral surface of the skewer such that the skewer becomes gradually thinner upward. The stepped surface of the stepped portion serves as a receiving surface for receiving the lower end of a cylindrical body having a smaller inner diameter than the inner diameter of the cylindrical body. A guiding portion is provided on the peripheral surface of the skewer to guide the lower end of the cylindrical body downward relative to the skewer when the skewer is inserted into the cylindrical body, The guiding portion extends linearly downward from the upper end of the peripheral surface of the skewer to a position lower than the height position of the lowermost stepped portion among the at least one stepped portion. The string includes five blade plate portions that project radially outward in a radius direction with respect to the central axis of the string, extend downward from the upper end portion to the lower end portion of the string, and are inserted and arranged within the cylindrical body. A pallet for a cylindrical body, wherein the outer ends of two of the five blade plate portions are the guide portions, and at least one step portion is formed at the outer ends of the remaining three blade plate portions respectively.

8. The pallet for a cylindrical body according to claim 6 or 7, wherein the opening angles between the blade plates adjacent to each other in the circumferential direction in the remaining three blade plate portions are each in the range of 80° to 110°.

9. A method for manufacturing a photosensitive drum, comprising cleaning the photosensitive drum substrate while holding the photosensitive drum substrate in a substantially upright state. A method for manufacturing a photosensitive drum, using the pallet for a cylindrical body according to any one of claims 1 to 8, and inserting and arranging the string of the pallet into the photosensitive drum substrate as a cylindrical body to hold the photosensitive drum substrate in a substantially upright state.

10. A method for manufacturing a photosensitive drum, comprising cleaning the photosensitive drum substrate while holding the photosensitive drum substrate in a substantially upright state. A method for manufacturing a photosensitive drum, using the pallet for a cylindrical body according to any one of claims 2, 3, 6, 7, and 8, and relatively lowering the lower end of the photosensitive drum substrate along the guide portion of the string with respect to the string so that the string of the pallet is inserted into the photosensitive drum substrate as a cylindrical body, thereby holding the photosensitive drum substrate in a substantially upright state.

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