Core shaft, elastomer roller and manufacturing method of elastomer roller

Abstract

Provided is a mandrel for an elastomer roller, an elastomer roller having the mandrel, and a method for manufacturing an elastomer roller, which can embed a mandrel and an elastic cover member without using an adhesive, can suppress the occurrence of adverse situations caused by air remaining between the mandrel and the elastic cover member (the material of the elastic cover member), and can discharge air present between the mandrel and the elastic cover member in a short time. A mandrel (2) for an elastomer roller (1) has a shaft-shaped mandrel main body (11) and an air passage (3) that is open on both an outer peripheral surface (11c) of the mandrel main body (11) and end surfaces (11a, 11b) of the mandrel main body (11).

Description

Technical Field

[0001] This invention relates to a mandrel, an elastomer roller, and a method for manufacturing an elastomer roller. Background Technology

[0002] Image forming devices such as copiers, printers, multifunction printers, and fax machines have various rollers. Among such rollers, rubber-coated rollers with a rubber sleeve fitted over the outer circumferential surface of the spindle are known.

[0003] For rubber-coated rollers, there are structures in which the mandrel and rubber sleeve are bonded together by adhesives or the like, and structures in which the mandrel and rubber sleeve are pressed in as described in Patent Document 1.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 4908782 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] As described above, in structures that use adhesives to bond the mandrel and rubber sleeve, equipment such as a coating machine for applying the adhesive is required. Furthermore, multiple processes are needed, including a heating process for curing the adhesive. Moreover, if the rubber sleeve, which is bonded to the mandrel, becomes defective during processing, the mandrel cannot be regenerated. As a result, the manufacturing cost of the rubber-coated roller increases.

[0009] On the other hand, as described in Patent Document 1, in the structure where the rubber sleeve is pressed into the mandrel, firstly, the rubber sleeve is mounted on the outer circumferential surface of the mandrel. At this time, compressed air is blown between the mandrel and the rubber sleeve to expand the rubber sleeve, making it easier for the rubber sleeve to fit onto the mandrel. Next, an O-ring is placed on the rubber sleeve. Then, while tightening the O-ring by hand, it is moved from one end of the rubber sleeve to the other, thereby expelling any air remaining between the mandrel and the rubber sleeve.

[0010] As described in Patent Document 1, in structures where the mandrel and rubber sleeve are pressed together without the use of adhesive, air between the mandrel and rubber sleeve may not be completely expelled depending on the thickness and hardness of the rubber sleeve and the shape of the mandrel. For example, sometimes the rubber sleeve, which is longer than the mandrel, is cut after being fitted onto the mandrel so that its length matches the length of the mandrel. In this case, the portion of the rubber sleeve protruding from the mandrel (the ear) flexes to block the outer periphery of the mandrel's end. Therefore, in the degassing process described above, where O-rings are used to expel air between the rubber sleeve and the mandrel, air between the rubber sleeve and the mandrel is difficult to expel from the end of the mandrel. Especially when the rubber sleeve is flexible, the ear of the rubber sleeve blocks the outer periphery of the mandrel's end more strongly, making it difficult for air between the rubber sleeve and the mandrel to escape. As a result, air may sometimes remain between the rubber sleeve and the mandrel at the end of the mandrel.

[0011] If air remains between the rubber sleeve and the mandrel, during finishing processes such as pressing the rubber sleeve into the mandrel, the low seal between the sleeve and mandrel may cause the rubber sleeve to twist or shift relative to the mandrel. To fully remove the air between the mandrel and the rubber sleeve, it is considered to spend time in a degassing process. However, spending such time would increase the manufacturing time required for the rubber-coated roller.

[0012] Against this backdrop, the present invention provides a mandrel for use in an elastomer roller, an elastomer roller having the mandrel, and a method for manufacturing the elastomer roller, which enables the mandrel and the elastic cover to be fitted together without the use of an adhesive, suppresses the occurrence of defects caused by air remaining between the mandrel and the elastic cover (the material of the elastic cover), and is able to expel the air present between the mandrel and the elastic cover in a short time.

[0013] Solution for solving the problem

[0014] The present invention is based on the following mandrel, the elastomer roller having the mandrel, and the method for manufacturing the elastomer roller.

[0015] (1) Mandrel, which is a mandrel used for elastomer rollers, wherein...

[0016] The mandrel includes:

[0017] A shaft-shaped mandrel body; and

[0018] An air passage is provided, which is open on both the outer peripheral surface of the mandrel body and the end face of the mandrel body.

[0019] (2) The mandrel according to (1), wherein the air passage includes a scribing groove extending axially along the outer peripheral surface.

[0020] (3) The mandrel according to (2), wherein the scribing groove is formed over the entire area along the axial direction of the mandrel body.

[0021] (4) According to the mandrel described in (2), wherein, as the scribing groove, a first scribing groove open on the end face of one axial end of the mandrel body and a second scribing groove open on the end face of the other axial end of the mandrel body are provided.

[0022] The first scribe groove and the second scribe groove are separated from each other.

[0023] (5) The mandrel according to (2), wherein the scribing groove is open on one end face of the mandrel body in the axial direction and closed on the other end face of the mandrel body in the axial direction.

[0024] (6) The mandrel according to any one of (2) to (5), wherein, when viewed from the axial direction of the mandrel, the width of the scribing groove is 0.1 mm to 2.2 mm, the depth of the scribing groove is 0.02 mm to 0.50 mm, and the value obtained by dividing the depth by the width is 0.03 or more.

[0025] (7) The mandrel according to any one of (2) to (6), wherein the length of the scribing groove in the axial direction of the mandrel body is 7 mm or more.

[0026] (8) The mandrel according to any one of (1) to (7), wherein the mandrel further includes a mandrel end that protrudes from the axial end face of the mandrel body and has an outer diameter smaller than the outer diameter of the mandrel body.

[0027] (9) Elastomer roller, wherein

[0028] The elastomer roller includes:

[0029] Hollow elastic covering; and

[0030] The mandrel described in any one of (1) to (8) has the elastic covering sleeved on the mandrel body.

[0031] (10) A method for manufacturing an elastomer roller, wherein,

[0032] The manufacturing method of this elastomer roller includes:

[0033] Preparation process, in which a hollow elastic covering and a mandrel as described in any one of (1) to (8) are prepared;

[0034] In the pressing-in process, the elastic covering is pressed into the mandrel by engaging its inner circumferential surface with the outer circumferential surface of the mandrel body; and

[0035] In the degassing process, air is discharged between the mandrel and the elastic cover through the air passage.

[0036] The effects of the invention

[0037] According to the present invention, when manufacturing an elastomer roller, the mandrel and the elastic cover can be fitted together without the use of adhesive, the occurrence of defects caused by air remaining between the mandrel and the elastic cover (the material of the elastic cover) can be suppressed, and the air present between the mandrel and the elastic cover can be discharged in a short time. Attached Figure Description

[0038] Figure 1 (A) is a front view of an elastomer roller according to an embodiment of the present invention, shown in partial section. Figure 1 (B) is a partial cross-sectional side view of the elastomer roller.

[0039] Figure 2 This is a magnified front view showing the main parts of the elastomer roller.

[0040] Figure 3 It is along Figure 2 Line III-III represents a partial cross-sectional view of the mandrel of the elastomer roller.

[0041] Figure 4 (A) and Figure 4 (B) are diagrams illustrating the manufacturing method of the elastomer roller.

[0042] Figure 5 (A) and Figure 5 (B) are diagrams illustrating the manufacturing method of the elastomer roller.

[0043] Figure 6 This is a diagram showing the first modified example of the elastomer roller.

[0044] Figure 7 This is a diagram showing the second variation of the elastomer roller.

[0045] Figure 8 It is a graph representing the results of vibration measurements taken by a measuring machine.

[0046] Explanation of reference numerals in the attached figures

[0047] 1. Elastomer roller; 2. Mandrel; 3. 3A, 3B. Air passages; 4. 4B. Elastic covering; 11. Mandrel body; 11a, 11b. End faces of the mandrel body; 11c. Outer circumferential surface of the mandrel body; 12a, 12b. Ends of the mandrel; 31. First scribing groove; 32. Second scribing groove; A. Axial direction; D. Depth of the scribing groove; L. Length of the scribing groove; W. Width of the scribing groove. Detailed Implementation

[0048] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Furthermore, in this specification and the accompanying drawings, structural elements having substantially the same functional structure are labeled with the same reference numerals, and repeated descriptions are omitted.

[0049] Figure 1 (A) is a front view of an elastomer roller 1 according to an embodiment of the present invention, shown in partial cutaway. Figure 1 (B) is a side view of the elastomer roller 1. Figure 2 This is a magnified partial cross-sectional front view of the main part of the elastomer roller 1. Figure 3 It is along Figure 2 Line III-III represents a partial cross-sectional view of the mandrel 2 of the elastomer roller 1.

[0050] Reference Figure 1 (A) Figure 3 The elastomer roller 1 is installed, for example, in image forming apparatuses such as copiers, printers, multifunction printers, and fax machines. The elastomer roller 1 is sometimes used as, for example, a charging roller for charging the photosensitive drum, a developing roller for supplying toner to the photosensitive drum, or a transfer roller for transferring toner images from the photosensitive drum to paper. The elastomer roller 1 can also be used as a counter roller arranged opposite to the transfer roller. Furthermore, the elastomer roller 1 can be a drive roller driven by an electric motor provided in the image forming apparatus, or a driven roller that rotates due to force applied by a transfer belt or the like.

[0051] The elastomer roller 1 has a spindle 2, an air passage 3 formed on the spindle 2, and an elastic covering 4 disposed on the outer periphery of the spindle 2.

[0052] The mandrel 2 is the mandrel used for the elastomer roller 1, and is formed of metal or synthetic resin, etc. The hardness of the mandrel 2 only needs to be high enough relative to the hardness of the elastic covering 4, and it is considered a rigid body relative to the elastic covering 4.

[0053] The mandrel 2 has a shaft-shaped mandrel body 11 and mandrel ends 12a and 12b that protrude from the axial end faces 11a and 11b of the mandrel body 11 and have an outer diameter smaller than that of the mandrel body 11.

[0054] In this embodiment, the mandrel 2 is formed using a cylindrical member 5 and a pair of end members 6a and 6b. The cylindrical member 5 constitutes a portion of the outer peripheral side of the end faces 11a and 11b of the mandrel body 11 and the outer peripheral surface 11c. The pair of end members 6a and 6b are fixed to both ends of the cylindrical member 5 by pressing or the like and constitute a portion of the inner peripheral side of the end faces 11a and 11b and the mandrel ends 12a and 12b. Alternatively, the end members 6a and 6b may be omitted, and the mandrel 2 may be formed using the cylindrical member 5. Furthermore, the cylindrical member 5 may be hollow or solid. Additionally, the mandrel 2 may be a one-piece molded product formed entirely from a single component.

[0055] The mandrel ends 12a and 12b protrude from a pair of end faces 11a and 11b of the mandrel body 11 along the axial direction A (hereinafter simply referred to as axial direction A) of the elastomer roller 1. The mandrel ends 12a and 12b are portions supported on bearings or the like (not shown) provided in the image forming apparatus. In this embodiment, each mandrel end 12a and 12b includes a portion with a relatively small outer diameter and a portion with a relatively large outer diameter, and the portion with the relatively large outer diameter is continuous with the corresponding end faces 11a and 11b of the mandrel body 11. In addition, the shape of the mandrel ends 12a and 12b is not particularly limited, and the mandrel ends 12a and 12b can be symmetrical or asymmetrical along the axial direction A.

[0056] The mandrel body 11 is the portion covered by the elastic covering member 4 by pressing. The mandrel body 11 is the portion with the largest outer diameter in the mandrel 2, having an outer diameter larger than the maximum value of the outer diameter of the mandrel ends 12a and 12b. In this embodiment, the outer peripheral surface 11c of the mandrel body 11 is a cylindrical surface. The diameter of the outer peripheral surface 11c of the mandrel body 11 (outer diameter of the mandrel 2) is, for example, about 6 to 50 mm. The total length of the mandrel body 11 (length along the axial direction A) is, for example, about 200 mm to about 1000 mm. Furthermore, the pair of end faces 11a and 11b of the mandrel body 11 are annular planes arranged orthogonally to the axial direction A. Alternatively, the pair of end faces 11a and 11b can also be formed into a tapered shape along the axial direction A, with the outer diameter decreasing as they approach the corresponding mandrel ends 12a and 12b.

[0057] In this embodiment, the air passage 3 is open on both the outer peripheral surface 11c and the end faces 11a and 11b of the mandrel body 11. The air passage 3 is provided to allow air to flow from the outer peripheral surface 11c of the mandrel 2 to the end faces 11a and 11b. More specifically, the air passage 3 is provided to discharge air present between the cylindrical material 40 and the outer peripheral surface 11c when the cylindrical material 40, which is the material of the elastic covering member 4, covers the outer peripheral surface 11c of the mandrel body 11.

[0058] As described later, after the cylindrical material 40 is pressed into the mandrel body 11, the ears 41a and 41b at both ends are cut and further ground on their outer peripheral surfaces to become the elastic covering 4. The inner diameter of the cylindrical material 40 in its free state without external force is smaller than the outer diameter of the mandrel body 11. Immediately after the cylindrical material 40 is pressed into the mandrel body 11, both ends of the cylindrical material 40 protrude from the mandrel body 11 in the axial direction A, and these protruding portions become the ears 41a and 41b. The ears 41a and 41b flex at both ends of the mandrel body 11 in the axial direction A to tighten the outer peripheral surface 11c of the mandrel body 11. Thus, the ears 41a and 41b tighten the outer peripheral edges of the pair of end faces 11a and 11b, hindering the flow of air between the cylindrical material 40 and the pair of end faces 11a and 11b.

[0059] In this embodiment, the air passage 3 is a scribing groove extending along the axial direction A of the outer peripheral surface 11c. In this specification, "scibing groove" refers to an elongated linear groove, regardless of the forming method. The air passage 3 can be formed using a tool for engraving scribing grooves, or using a machine tool cutting tool, etc. In this embodiment, the air passage 3 is formed over the entire axial region of the mandrel body 11. The air passage 3 is open at one end face 11a on the axial side of the mandrel body 11, and open at the other end face 11b on the axial side of the mandrel body 11. In this embodiment, the air passage 3 is formed parallel to the axial direction A. The air passage 3 is not completely blocked by the ears 41a, 41b of the cylindrical material 40; at least a portion of it is open relative to the outside of the mandrel body 11.

[0060] In this embodiment, an air passage 3 is provided, but it may not be. The air passage 3 may, for example, be formed at multiple locations on the circumferential mandrel body 11 of the elastomer roller 1. Furthermore, the air passage 3 may be formed in a spiral shape or the like on the outer circumferential surface of the mandrel body 11, thereby extending along the axial direction A without being parallel to it.

[0061] The section orthogonal to axis A (hereinafter also referred to as the axial section). Figure 3 When observing the mandrel body 11 in the cross-section shown, the air passage 3 is formed in shapes such as the letter V, letter U, or letter W. In the axial section, the air passage 3 is a fine groove, formed, as previously described, for example, by cutting the outer peripheral surface 11c of the mandrel body 11 using a tool such as a cutting tool. Therefore, the shape of the air passage 3 is affected by the shape of the aforementioned tool. In this embodiment, the air passage 3 is formed in the axial section as a letter V shape without sharp edges.

[0062] In the axial section, that is, when viewed from the axial direction of the mandrel 2, it is preferable that the width W of the air passage 3 is 0.1 mm to 2.2 mm. With a width W of 0.1 mm or more, air can pass smoothly through the air passage 3, reliably expelling air between the ears 41a and 41b of the cylindrical material 40 and the outer peripheral surface 11c of the mandrel body 11 from between the cylindrical material 40 and the mandrel body 11. Furthermore, with a width W of 2.2 mm or less, the width of the air passage 3 is not excessive. Therefore, when the cylindrical material 40 is formed into the elastic cover 4 by grinding the outer peripheral surface of the cylindrical material 40 pressed into it by a tool such as a grinding wheel against the mandrel 2, the degree to which the cylindrical material 40 deforms in a concave manner due to the entry of the cylindrical material 40 into the air passage 3 is minimized. As a result, the dimensional accuracy of the outer peripheral surface of the elastic cover 4 can be improved. Furthermore, the lower limit of the width W of the air passage 3 is more preferably 0.5 mm, and even more preferably 1.2 mm. In addition, the upper limit of the width W of the air passage 3 is more preferably 1.85 mm.

[0063] In the axial section, it is preferable that the depth D of the air passage 3 is 0.02 mm to 0.50 mm. A depth D of 0.02 mm or more allows air to pass smoothly through the air passage 3, reliably expelling air between the cylindrical material 40 and the outer peripheral surface 11c of the mandrel body 11. Furthermore, a depth D of 0.50 mm or less prevents the air passage 3 from becoming too deep. Therefore, when the cylindrical material 40 is formed into an elastic covering 4 by grinding its outer peripheral surface by pressing a tool such as a grinding wheel against the mandrel 2, the degree to which the cylindrical material 40 deforms in a concave manner due to entering the air passage 3 is minimized. As a result, the dimensional accuracy of the outer peripheral surface of the elastic covering 4 can be improved. Furthermore, the lower limit of the depth D of the air passage 3 is more preferably 0.15 mm, and even more preferably 0.25 mm. Furthermore, the upper limit of the depth D of the air passage 3 is more preferably 0.45 mm, and even more preferably 0.30 mm.

[0064] In this embodiment, in order to smoothly discharge air between the cylindrical material 40 and the mandrel body 11, it is more preferable to also consider the ratio of the width W to the depth D of the air passage 3. Specifically, it is preferable that the value D / W, obtained by dividing the depth D of the air passage 3 by the width W, is 0.03 or more. As mentioned above, when the cylindrical material 40 is pressed into the outer peripheral surface 11c of the mandrel body 11, the axial end on the outer peripheral surface 11c of the mandrel body 11 and the ears 41a, 41b of the cylindrical material 40 are blocked by the ears 41a, 41b. However, even in this state, by having a value D / W of 0.03 or more, the air passage 3 has a sufficient depth D relative to the width W, so that the outer peripheral edges of the end faces 11a, 11b are not blocked by the cylindrical material 40, and air can be discharged from between the cylindrical material 40 and the mandrel 2 to the outside more reliably.

[0065] In this embodiment, it is preferable that the length L of the air passage 3 in the axial direction A is 7 mm or more. When the cylindrical material 40 is fitted onto the mandrel body 11, the ears 41a and 41b block the outer peripheral edges of the end faces 11a and 11b of the mandrel body 11, thus creating a tendency for air to easily accumulate at the end of the mandrel body 11 in the axial direction A. Even in this case, by setting the length L to 7 mm or more, air can be more reliably discharged from the area where air is likely to accumulate. In this embodiment, the length L is the same as the total length of the mandrel body 11.

[0066] The elastic cover 4 is, for example, a portion that holds an image forming agent such as toner or a transfer belt. The elastic cover 4 is a cylindrical shaft-shaped member, formed into a hollow shape. The elastic cover 4 is fitted onto the outer peripheral surface 11c of the mandrel body 11. The elastic cover 4 is disposed over the entire area along the axial direction A of the mandrel body 11. Additionally, one end face 4a of the elastic cover 4 along the axial direction A may be positioned approximately 5 mm away from the end face 11a on one side of the mandrel body 11, moving inward (towards the center side of the mandrel body 11 along the axial direction A) or outward. Similarly, the other end face 4b of the elastic cover 4 along the axial direction A may be positioned approximately 5 mm away from the end face 11b on the other side of the mandrel body 11, moving inward or outward along the axial direction A. In its standalone state, when not installed on the mandrel body 11, the inner diameter of the elastic cover 4 is smaller than the outer diameter of the mandrel body 11; its inner diameter expands when fitted onto the mandrel body 11. Thus, the elastic covering 4 is pressed into the mandrel body 11. The wall thickness of the elastic covering 4 when pressed into the mandrel body 11 is, for example, a few millimeters, but no specific value is limited.

[0067] Examples of materials that can be used for the elastic covering 4 include NBR, epichlorohydrin rubber, polyurethane, EPDM, other synthetic rubbers, and sponge. The hardness of the elastic covering 4 is not particularly limited, but when the elastic covering 4 is made of rubber, examples show a hardness of 40 to 80 on an A-type hardness tester. Furthermore, when the elastic covering 4 is made of sponge, examples show a hardness of 20 to 80 on an Asker C hardness tester.

[0068] The lower the hardness of the elastic covering 4, the greater the degree to which the outer periphery of the pair of end faces 11a, 11b of the spindle body 11 is covered by the ears 41a, 41b at both ends of the cylindrical material 40. Therefore, even in the case of the lowest hardness and softness mentioned above, it is necessary to ensure that the air passage 3 is not blocked by the cylindrical material 40 at the end faces 11a, 11b. As such a structure, as described above, it is preferable that the value D / W obtained by dividing the depth D by the width W is 0.03 or higher.

[0069] The pair of end faces 4a and 4b of the elastic cover 4 are opposite to the air passage 3 in the radial direction of the spindle 2, or are located outside the air passage 3 in the axial direction A.

[0070] The above is a general structure of the elastomer roller 1. Next, an example of the manufacturing method of the elastomer roller 1 will be described.

[0071] Reference Figure 4 In manufacturing the elastomer roller 1, firstly, a mandrel 2 and a cylindrical material 40 (a hollow elastic covering) are prepared (preparation process). The total length of the cylindrical material 40 is, for example, a few mm to a few cm longer than the total length of the mandrel body 11.

[0072] Next, the cylindrical material 40 is pressed into the mandrel body 11 by fitting its inner circumferential surface with the outer circumferential surface 11c. At this time, the cylindrical material 40 is enlarged in inner diameter and mounted on the mandrel body 11 by compressed air B supplied from a nozzle 51 located on one end face 40a of the cylindrical material 40. The supply of compressed air is stopped after the cylindrical material 40 is fitted onto the mandrel body 11, thereby tightening the cylindrical material 40 against the mandrel body 11 and pressing it in. Thus, as... Figure 4As shown in (B), a manufacturing intermediate 21 is completed, in which the cylindrical material 40 is fitted onto the outer peripheral surface 11c of the mandrel body 11. In the manufacturing intermediate 21, the lugs 41a and 41b of the cylindrical material 40, located near the end faces 11a and 11b of the mandrel body 11, elastically deform to tighten the two ends of the mandrel body 11. Furthermore, in the manufacturing intermediate 21, air C remains between the outer peripheral surface 11c of the mandrel body 11 and the inner peripheral surface of the cylindrical material 40. As described above, this air remains due to the supply of compressed air or the like.

[0073] Next, the manufacturing intermediate 21 is degassed (vented) (degassing process). In the degassing process, for example, the manufacturing intermediate 21 is left to stand for a few minutes. As a result, the air C between the mandrel body 11 and the cylindrical material 40 is discharged to the outside of the manufacturing intermediate 21 through the air passage 3.

[0074] like Figure 5 As shown in (A), the cylindrical material 40 is cut into the degassed manufacturing intermediate 21. During cutting, the ears 41a and 41b of the cylindrical material 40 are cut off using a cutter 52. By cutting off the ears 41a and 41b of the cylindrical material 40, the positions of the pair of end faces 40a and 40b of the cylindrical material 40 are aligned with the positions of the pair of end faces 11a and 11b of the mandrel body 11. Alternatively, the positions of the pair of end faces 40a and 40b of the cut cylindrical material 40 may be offset relative to the corresponding end faces 11a and 11b of the mandrel body 11 within a range of 0.5 mm in the axial direction A. By cutting the cylindrical material 40, the manufacturing intermediate 21 becomes the final manufacturing intermediate 22.

[0075] Next, refer to Figure 5 (B) While rotating the final manufacturing intermediate 22, the outer circumferential surface of the cylindrical material 40 is ground using the grinding tool 53, so that the outer diameter of the cylindrical material 40 becomes the outer diameter of the elastic covering 4. Thus, the cylindrical material 40 becomes the elastic covering 4, completing the elastomer roller 1.

[0076] As explained above, according to this embodiment, the air passage 3 is open on both the outer peripheral surface 11c and the end faces 11a and 11b of the mandrel body 11. Therefore, by placing the manufacturing intermediate 21 for only a short time, air between the cylindrical material 40 and the mandrel body 11 can be discharged to the outside via the air passage 3. With this structure, unlike degassing operations that involve manually or mechanically tightening the cylindrical material 40 while moving the tightening position from one end of the manufacturing intermediate 21 to the other to discharge air, less time and effort is required for degassing. Furthermore, unlike degassing performed manually, the degree of degassing does not vary depending on the operator's skill level, and stable degassing performance can be achieved using the air passage 3. This reduces the quality deviation of the elastomer roller 1. In addition, since degassing between the elastic covering 4 and the mandrel body 11 is reliably performed, the tightness between the elastic covering 4 and the mandrel body 11 can be improved. Therefore, defects caused by air C remaining between the elastic cover 4 and the mandrel body 11 will not occur. Examples of such defects include: when grinding the cylindrical material 40, the cylindrical material 40 will undergo unexpected dent deformation at the location where air C exists, resulting in a decrease in the dimensional accuracy of the elastic cover 4; when cutting and grinding the cylindrical material 40, the cylindrical material 40 will twist; and the cylindrical material 40 will shift in position relative to the mandrel body 11 along the axial direction A. As a result, the mandrel 2 and the elastic cover 4 can be fitted together without the use of adhesive, defects caused by air remaining between the mandrel 2 and the elastic cover 4 can be suppressed, and the air present between the mandrel 2 and the elastic cover 4 (cylindrical material 40) can be expelled in a short time, thereby improving the production efficiency of the elastomer roller 1.

[0077] Furthermore, according to this embodiment, the air passage 3 includes a scribing groove extending along the axial direction A. Thus, the air passage 3 can be formed with a simple structure, where the scribing groove is formed on the outer peripheral surface 11c of the spindle body 11, i.e., the portion covered by the elastic covering member 4.

[0078] Furthermore, according to this embodiment, the scribing groove constituting the air passage 3 is formed over the entire axial region. With this structure, air between the mandrel body 11 and the cylindrical material 40 can be discharged more reliably and quickly via the air passage 3.

[0079] Furthermore, according to this embodiment, the mandrel 2 includes mandrel ends 12a and 12b that protrude from the axial end faces 11a and 11b of the mandrel body 11 and have an outer diameter smaller than the outer diameter of the mandrel body 11. With this structure, the shapes of the mandrel ends 12a and 12b and the shape of the mandrel body 11 pressed into the elastic cover 4 can be freely set, and the mandrel ends 12a and 12b are set to have an outer diameter that matches that of the bearing or the like that supports the elastic roller 1. This increases the design freedom of the elastic cover 4.

[0080] The embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments and modifications, and various modifications can be made within the scope of the claims.

[0081] (1) In the above embodiment, the example is described in which the air passage 3 is formed over the entire axial region of the spindle body 11. However, this is not always the case. Figure 6 This is a diagram showing the first modified example of the elastomer roller. (See diagram below.) Figure 6 As shown, an elastomer roller 1A with a pair of scribing grooves can also be used instead of the elastomer roller 1. The difference between the elastomer roller 1A and the elastomer roller 1 is that air passages 3A are formed only at both ends of the spindle body 11 in the axial direction.

[0082] The air passage 3A, as a scribing groove, has: a first scribing groove 31, which is open at one end face 11a on the axial side of the mandrel body 11; and a second scribing groove 32, which is open at the other end face 11b on the axial side of the mandrel body 11. Furthermore, the first scribing groove 31 and the second scribing groove 32 are separate from each other. Preferably, the first scribing groove 31 and the second scribing groove 32 each have a length L of at least 7 mm in the axial direction A. The structure of the first scribing groove 31 and the second scribing groove 32 is equivalent to omitting the structure of the middle portion in the axial direction A in the air passage 3 of the embodiment; therefore, detailed description is omitted. Furthermore, the first scribing groove 31 and the second scribing groove 32 are formed in a symmetrical shape in the axial direction A, but they can also be asymmetrical in the axial direction A. In addition, the cross-sectional shapes at the sections orthogonal to the axial direction A can also be different. Furthermore, the positions of the first scribe groove 31 and the second scribe groove 32 in the circumferential direction of the mandrel body 11 are the same in this modified example, but they may also be different.

[0083] Even when the first scribing groove 31 and the second scribing groove 32, which are separately arranged in the axial direction A, form an air passage 3A, the air between the cylindrical material 40 and the mandrel body 11 can be quickly discharged through the air passage 3A during the degassing process.

[0084] (2) In the above-described embodiment and the first variation, the example was described with the elastic covering 4 disposed over the entire area along the axial direction A of the spindle body 11. However, this is not always the case. Figure 7 This is a diagram showing the second variation of the elastomer roller. (See diagram for example.) Figure 7 As shown, an elastomer roller 1B with an air passage 3B can also be used instead of the elastomer roller 1. The difference between the elastomer roller 1B and the elastomer roller 1 is that the air passage 3B is interrupted at the middle part 11d of the mandrel body 11, and the total length of the elastic covering 4B is shorter than the total length of the mandrel body 11.

[0085] One end face 4a of the elastic cover 4B is disposed near one end face 11a of the spindle body 11, directly opposite the air passage 3B. The other end face 4b of the elastic cover 4B is disposed in the middle portion 11d along the axial direction A of the spindle body 11, away from the other end face 11b of the spindle body 11. The other end face 4b of the elastic cover 4B may or may not be opposite the air passage 3B. The air passage 3B is formed by a scribing groove, open at one end face 11a along the axial direction of the spindle body 11 and closed at the other end face 11b along the axial direction of the spindle body 11. Preferably, the length L of the air passage 3B is at least 7 mm. The air passage 3B corresponds to the structure of the air passage 3 in the embodiment where the middle portion along the axial direction A and the other end are omitted; therefore, detailed description is omitted.

[0086] In this second variation, during the pressing process, the other end face 40b of the cylindrical material 40B, which serves as the material for the elastic covering 4B, is disposed in the middle portion 11d of the mandrel body 11. In this case, the portion near the other end face 40b of the cylindrical material 40B (the other end 40e) fits into the outer peripheral surface 11c of the mandrel body 11 without creating an ear. Therefore, the other end 40e of the cylindrical material 40B is configured to non-airtightly block the space between the cylindrical material 40B and the mandrel body 11. That is, in the structure where the other end 40e of the cylindrical material 40B is disposed in the middle portion 11d of the mandrel body 11, the cylindrical material 40B does not obstruct the airflow between the other end 40e of the cylindrical material 40B and the mandrel body 11. Therefore, even if there is no air passage 3B between the other end 40e of the cylindrical material 40B and the outer peripheral surface 11c of the mandrel body 11, the air present between the other end 40e of the cylindrical material 40B and the mandrel body 11 can be smoothly discharged. Furthermore, since an air passage 3B is provided between the ear 41a formed at one end of the cylindrical material 40B and one end of the mandrel body 11, the air on one end face 11a of the mandrel body 11, and the air between the cylindrical material 40B and the mandrel body 11, can also be smoothly discharged. Moreover, since the air passage 3B only needs to be formed on a portion of the mandrel body 11 in the axial direction, the time spent on cutting and forming the air passage 3B can be further reduced.

[0087] (3) Furthermore, in the above-described embodiments and variations, the air passages 3, 3A, and 3B are explained as examples where they are open on the outer peripheral surface 11c of the spindle body 11. However, this is not always the case. For example, a channel-shaped air passage may be formed inside the spindle body 11, with one end of the air passage open on the outer peripheral surface 11c of the spindle body 11, and the other end of the air passage open on at least one of the end faces 11a and 11b of the spindle body 11.

[0088]

Example

[0089] Elastomer rollers were manufactured as Examples 1 to 8 and Comparative Examples 1 and 2. The manufacturing methods for each example are as follows: First, the cylindrical material is pressed into the mandrel body by fitting its inner circumferential surface with the outer circumferential surface of the mandrel body. At this time, compressed air is blown from one end of the cylindrical material while it is mounted onto the mandrel body. This creates a manufacturing intermediate with the cylindrical material fitted onto the outer circumferential surface of the mandrel. Next, a degassing process is performed on the manufacturing intermediate. During the degassing process, the manufacturing intermediate is left to stand for several minutes. Next, the two ends of the cylindrical material in the degassed manufacturing intermediate are cut so that the total length of the cylindrical material matches the total length of the mandrel body, thus becoming the final manufacturing intermediate. Next, the outer circumferential surface of the cylindrical material in the final manufacturing intermediate is ground so that the outer diameter of the cylindrical material becomes the outer diameter of the covering elastic material. This makes the cylindrical material an elastic covering, completing the elastomeric roller.

[0090] Examples 1 and 2 have the same structure as the elastomeric roller 1A shown in the first modified example, and the air passage has a first scribing groove and a second scribing groove.

[0091] Examples 3 to 6 have the same structure as the elastomer roller 1 shown in the embodiment, with air passages formed in the entire axial region of the mandrel body.

[0092] Examples 7 and 8 have the same structure as the elastomeric roller 1A shown in the first modified example, and the air passage has a first scribing groove and a second scribing groove.

[0093] Comparative Examples 1 and 2 have the same structure as the elastomer roller 1 shown in the embodiment, except that no air passage is formed.

[0094] The width W, depth D, length L, and the value D / W obtained by dividing depth D by width W for each embodiment are shown in Table 1. Furthermore, depth D and width W were measured using a VR-3000 manufactured by Keyence Corporation. In addition, the outer diameter of the mandrel body, the total length of the mandrel body, and the hardness of the elastic covering were measured for each embodiment. The hardness was measured by applying a 1 kg load to the elastomer roller using a Type A hardness tester or an Asker C hardness tester.

[0095] Table 1

[0096]

[0097] <Evaluation Methods>

[0098] For each embodiment, the venting, cutting position, and product vibration were evaluated.

[0099] Regarding venting, in the final manufacturing intermediate, it is measured whether air remains between the cylindrical material and the mandrel body. The measurement method is as follows: Holding the final manufacturing intermediate of Examples 1 to 8 and Comparative Examples 1 to 2, with the mandrel not rotating, the cylindrical material is rotated relative to the mandrel by hand, and it is confirmed whether the cylindrical material moves (rotates) independently in the circumferential direction. The tightness between the cylindrical material and the mandrel body is confirmed by tactile evaluation. Specifically, if the cylindrical material does not rotate, it is considered that venting has been completed, and the evaluation is A. Furthermore, if the cylindrical material is found to be rotating by tactile evaluation, it is considered that air remains, and the evaluation is B.

[0100] Regarding the cutting position, when the manufacturing intermediates of Examples 1 to 8 and Comparative Examples 1 to 2 were formed into the final manufacturing intermediates, the positional offset of the two end faces of the cylindrical material along the axial direction A was measured relative to the target cutting position of the two end faces of the cylindrical material. Cases with an offset of less than 0.5 mm were evaluated as A, cases with an offset of 0.5 mm to 1.5 mm were evaluated as B, and cases with an offset greater than 1.5 mm were evaluated as C.

[0101] Regarding product vibration, the vibration of the outer peripheral surface of the elastic covering was measured using a measuring machine while the mandrel end of each embodiment was rotated on the bearing. The measuring machine used was a laser scanning measuring instrument "LSM506S" manufactured by Mitutoyo Corporation. Figure 8 An image showing the results of vibration measurements taken by a measuring machine. Figure 8 The horizontal axis represents the axial measurement position of the mandrel body, with one end face of the mandrel body as the reference (zero mm position). Figure 8 The vertical axis represents the vibration magnitude. For vibration magnitude measured by a measuring machine, as shown in Example 1 of the attached diagram, if there is a location where the vibration magnitude is prominent and exhibits a large value, that location is defined as a vibration anomaly. A vibration anomaly is a location where the vibration magnitude varies by more than 20% within a 200mm range from the measurement position. On the other hand, as... Figure 8As shown in Example 2 regarding vibration amount, there are no abnormal vibration areas where there are no areas with prominent vibration amounts exhibiting large values. Furthermore, the presence or absence of abnormal vibration areas is determined based on the rate of change of vibration amount, and is not affected by the absolute value of the vibration amount. Examples 1 to 8 and Comparative Examples 1 to 2 were examined for the presence or absence of abnormal vibration areas. Cases without abnormal vibration areas were rated as A. The elastomer rollers rated A did not experience any defects caused by air remaining between the mandrel and the elastic covering (cylindrical material) during the manufacturing process, and were thus judged to have high vibration accuracy (low vibration amount). Cases with abnormal vibration areas were rated as B. The elastomer rollers rated B experienced defects caused by air remaining between the mandrel and the elastic covering (cylindrical material) during the manufacturing process, resulting in an impact on the vibration accuracy of the elastomer roller. Therefore, they were judged to have low dimensional accuracy (high vibration amount).

[0102] The results are shown in Table 1.

[0103] As shown in Table 1, all Examples 1 to 8 have air passages, resulting in an A rating for exhaust, cutting position, and product vibration. Specifically, for Examples 1 to 8, the width W of the air passage 3 is in the range of 0.1 mm to 2.2 mm, the depth D is in the range of 0.02 mm to 0.50 mm, and the value D / W obtained by dividing the depth D by the width W is 0.03 or higher. Therefore, exhaust, cutting position, and product vibration all receive an A rating. On the other hand, Comparative Examples 1 and 2 do not have air passages, regardless of the outer diameter of the mandrel or the overall length of the mandrel body. Consequently, exhaust, cutting position, and product vibration all receive the lowest ratings, resulting in poor exhaust between the cylindrical material and the mandrel body.

[0104] Based on the evaluation results of Examples 1 to 8 and Comparative Examples 1 to 2, it is clear that by providing an air passage that is open on both the outer peripheral surface and the end face of the mandrel body, air existing between the elastic cover and the mandrel body can be effectively discharged. The results confirm that it is possible to suppress the occurrence of adverse conditions caused by air remaining between the mandrel and the elastic cover (the cylindrical material that serves as the material of the elastic cover).

[0105] Industrial availability

[0106] This invention is applicable to the manufacturing methods of mandrels, elastomer rollers, and elastomer rollers.

Claims

1. A mandrel for use as an elastomer roller, wherein, The mandrel includes: A shaft-shaped mandrel body; and An air passage is provided, which is open on both the outer peripheral surface of the mandrel body and the end face of the mandrel body. The air passage includes a scribing groove extending axially along the outer peripheral surface. As the scribing groove, a first scribing groove is provided, which is open on one end face of the mandrel body and formed in a portion of the axial direction of the mandrel body, and a second scribing groove is open on the other end face of the mandrel body and formed in a portion of the axial direction of the mandrel body. The scribing groove is not formed in the axial center of the mandrel body, and the first scribing groove and the second scribing groove are separated from each other.

2. The mandrel according to claim 1, wherein, When viewed from the axial direction of the mandrel, the width of the scribing groove is 0.1mm to 2.2mm, the depth of the scribing groove is 0.02mm to 0.50mm, and the value obtained by dividing the depth by the width is greater than 0.

03.

3. The mandrel according to claim 1 or 2, wherein, The scribe groove has an axial length of 7 mm or more on the mandrel body.

4. The mandrel according to claim 1 or 2, wherein, The mandrel also includes a mandrel end that protrudes from the axial end face of the mandrel body and has an outer diameter smaller than that of the mandrel body.

5. An elastomer roller, wherein, The elastomer roller includes: Hollow elastic covering; and The mandrel according to any one of claims 1 to 4, wherein the elastic covering is sleeved on the mandrel body.

6. A method for manufacturing an elastomer roller, wherein, The manufacturing method of this elastomer roller includes: The preparation process includes preparing a hollow elastic covering and a mandrel as described in any one of claims 1 to 4; A pressing-in process, in which the elastic covering is pressed into the mandrel by engaging the inner circumferential surface of the elastic covering with the outer circumferential surface of the mandrel body; and In the degassing process, air is discharged between the mandrel and the elastic cover through the air passage.

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