Axle seal and method for manufacturing the same

Abstract

This enables improved manufacturing efficiency for shaft seals. [Solution] A method for manufacturing an annular shaft seal from an intermediate product having a strip-shaped base material and a fiber member located on the first surface side of the base material, using a first mold having a first recess, a second mold having a second recess, and a pin. The method comprises a first bending step in which the intermediate product is sandwiched between the pin and the first recess, with the pin positioned on the first surface side, and the intermediate product is bent so that the bending point is the central part in the longitudinal direction of the strip-shaped base material; and a second bending step in which the intermediate product, with a portion located between the pin and the first recess, is sandwiched between the first recess and the second recess to form an annular shape.

Description

Technical Field

[0001] The present invention relates to a shaft seal and a method for manufacturing the same.

Background Art

[0002] For example, in the developing unit of an electrophotographic system, a shaft seal is used to prevent powders such as toner and carrier from leaking outside the apparatus through the shaft portion of a rotating body (see Patent Document 1). The shaft seal has an annular base material and a fiber member located on the inner peripheral side of the base material. The fiber member is constituted by, for example, a pile fabric or a pile knitted fabric including cut pile.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventionally, as shown in FIG. 12(A), a method for manufacturing a shaft seal as described above is performed by bending an intermediate product 90 having a linear belt-shaped base material 91 and a fiber member 92 located on the first surface 911 side of the base material 91 using a mold 100. That is, the belt-shaped intermediate product 90 is placed on the first lower mold 99 (FIG. 12(A)), and the intermediate product 90 is formed into a W shape having an arc by the first punch 98 (FIG. 12(B)). The intermediate product 90 formed into a W shape is removed from the first lower mold 99 and placed on a second lower mold 97 different from the first lower mold 99 (FIG. 12(C)). Then, the intermediate product 90 is formed into an annular shape by a second punch 96 different from the first punch 98 (FIG. 12(D)). An annular shaft seal is manufactured in this way.

[0005] The object of the present invention is to provide a method for manufacturing shaft seals that has a new technical means that enables improved manufacturing efficiency compared to conventional methods, and to provide shaft seals manufactured by this method. [Means for solving the problem]

[0006] The present invention provides a method for manufacturing an annular shaft seal, which involves producing a first type having a first recess, a second type having a second recess, and a pin, from an intermediate product having a strip-shaped base material and a fiber member located on the first surface side of the base material. The method comprises a first bending step in which the intermediate product is sandwiched between the pin and the first recess, with the pin positioned on the first surface side, and the intermediate product is bent so that the bending point is the central part in the longitudinal direction of the strip-shaped base material; and a second bending step in which the intermediate product, with a portion of it located between the pin and the first recess, is sandwiched between the first recess and the second recess to form an annular shape.

[0007] The shaft seal of the present invention comprises an annular base material having a gap at one location in the circumferential direction, and a fibrous member located on the inner circumference side of the base material. The outer surface of the substrate has grooves parallel to the center line of the substrate at two separate locations along its circumferential direction, and these grooves are positioned symmetrically with respect to a virtual plane that passes through the gap and the center line. [Effects of the Invention]

[0008] According to the present invention's method for manufacturing shaft seals, it is possible to improve the manufacturing efficiency of shaft seals. The shaft seal of the present invention is obtained by a method that enables improved manufacturing efficiency and cost reduction. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic diagram showing one embodiment of a shaft seal. [Figure 2] Figure 2 is a schematic diagram showing one form of shaft sealing. [Figure 3]Figure 3 is an explanatory diagram showing the usage state of the shaft seal. [Figure 4] Figure 4 is a diagram illustrating the manufacturing method of a shaft seal. [Figure 5] Figure 5 is a diagram illustrating the manufacturing method of a shaft seal. [Figure 6] Figure 6 is a diagram illustrating the manufacturing method of a shaft seal. [Figure 7] Figure 7 is a diagram illustrating the manufacturing method of a shaft seal. [Figure 8] Figure 8 is a diagram illustrating the manufacturing method of a shaft seal. [Figure 9] Figure 9 is a diagram illustrating the manufacturing method of a shaft seal. [Figure 10] Figure 10 is a diagram showing the main type and the secondary type separated. [Figure 11] Figure 11 is an explanatory diagram of the pin and its surroundings. [Figure 12] Figure 12 is a diagram illustrating a conventional method for manufacturing shaft seals. [Modes for carrying out the invention]

[0010] <Overview of Embodiments> (1) The method for manufacturing an axle seal is to manufacture an annular axle seal from an intermediate product having a strip-shaped base material and a fiber member located on the first surface side of the base material, using a first type having a first recess, a second type having a second recess, and a pin. The method comprises a first bending step in which the intermediate product is sandwiched between the pin and the first recess, with the pin positioned on the first surface side, and the intermediate product is bent so that the bending point is the central part in the longitudinal direction of the strip-shaped base material; and a second bending step in which the intermediate product, with a portion of it located between the pin and the first recess, is sandwiched between the first recess and the second recess to form an annular shape.

[0011] According to the manufacturing method, a substantially V-shaped intermediate product with the central portion in the longitudinal direction of the strip-shaped base material as the bending point is obtained (first bending step). With a part of the intermediate product positioned between the pin and the first concave portion, the intermediate product is sandwiched between the first concave portion and the second concave portion and becomes annular (second bending step). Thereby, an annular shaft seal is manufactured. Without removing the intermediate product from the first mold, a shaft seal can be obtained, and the manufacturing efficiency can be improved.

[0012] (2) In the manufacturing method of (1) above, both ends of the base material of the intermediate product bent by the first bending step protrude from the first concave portion toward the second concave portion side. In the second bending step, while bringing the both ends into contact with the second concave portion and along the second concave portion, the base material is plastically deformed along the second concave arc surface having a shape along the circle of the second concave portion, and along the first concave arc surface having a shape along the circle of the first concave portion, the base material is plastically deformed to make the intermediate product annular. In the second bending step, the base material is bent by the first concave arc surface and the second concave arc surface over its entire circumference. The springback of the base material is suppressed, and the intermediate product becomes a desired annular shape.

[0013] (3) In the manufacturing method of (2) above, starting from the completion of the first bending step, the second bending step is started while the relative positions of the pin and the first concave portion do not change. The pin used in the first bending step remains between the first concave portion and the second concave portion in the second bending step. The intermediate product bent in the first bending step is positioned at the first concave portion by the pin. Moreover, the relative positions of the first concave portion and the pin do not change from the completion of the first bending step to the completion of the second bending step. When proceeding from the first bending step to the second bending step, it becomes possible to prevent the intermediate product from falling off the first mold.

[0014] (4) In any one of the manufacturing methods described in (1) to (3) above, the pin has a convex arc surface that contacts the portion of the fiber member corresponding to the central part in the longitudinal direction of the strip-shaped base material, and a pair of sides located on both sides of the convex arc surface, wherein the convex arc surface has a shape along a virtual circle centered on a reference line, and each of the pair of sides is a surface located on the reference line side of the virtual circle.

[0015] In the first bending process, the strip-shaped base material is pressed and bent via the fiber member by the convex arc surface of the pin, and the central part of the base material becomes arc-shaped. The fiber member located at the position corresponding to the central part of the base material is pressed with a certain force by the convex arc surface, but this is only a part of the fiber member, and this part of the fiber member returns to its original shape after the shaft seal is manufactured due to restoring force. In the first bending process, the base material is bent into an annular shape by the first and second recesses in the second bending process. However, the sides of the pins are kept from making strong contact with the fiber member, thus preventing the fiber member from being crushed.

[0016] (5) In the manufacturing method of (4) above, the pin has an outer surface located on the opposite side of the convex arc surface, and the outer surface is a surface located on the reference line side of the virtual circle. In the second bending process, the outer surface of the pin is kept from making strong contact with the fiber member, thus preventing the fiber member from being crushed.

[0017] (6) In any one of the manufacturing methods described in (1) to (5) above, the pin has a convex arc surface that contacts the portion of the fiber member corresponding to the central part in the longitudinal direction of the strip-shaped base material, the first recess has a first concave arc surface that is circular in shape and contacts the central part of the base material, and the radius of the convex arc surface is smaller than the value obtained by dividing the radius of the first concave arc surface by the thickness of the base material. In the first and second bending processes, a gap is created between the convex arc surface of the pin and the central portion of the base material along the first concave arc surface of the first recess. This gap is maintained as a layer of fiber material, preventing the fiber material from being strongly crushed.

[0018] (7) In the manufacturing method of (6) above, the radius of the convex arc surface is greater than the value obtained by dividing the radius of the first concave arc surface by the thickness of the base material, and then further dividing that value by 1 / 5 of the layer thickness of the free-state fiber member. The convex arc surface of the pin compresses a portion of the fiber member, and the base material is bent through that fiber member.

[0019] (8) In any one of the manufacturing methods described in (1) to (7) above, the first mold comprises a main mold having a first concave arc surface that can contact the central part of the strip-shaped base material as part of the first recess, and a sub-mold which is a separate member from the main mold and has a support surface that can contact an intermediate part of the base material between the central part and the end in the first bending step as another part of the first recess. In the first bending process, when the intermediate product is bent into a roughly V-shape with the center of the base material as the bending point, the support surface contacts the intermediate portion of the base material and functions as a fulcrum for that portion. Even if both ends of the first concave arc surface become thin and weak in terms of strength, the ends of the first concave arc surface do not need to be used as fulcrums for the intermediate portion of the base material. In other words, the thinned ends of the first concave arc surface are protected.

[0020] (9) In any one of the manufacturing methods described in (1) to (8) above, the second mold has a spacer at the bottom of the second recess that allows both end faces of the base material to come into contact with it. In the second bending process, the base material of the intermediate product is plastically deformed along the second concave arc surface, which is shaped to the circle of the second recess, while both ends of the base material of the intermediate product are brought into contact with and along the second recess. As a result, both ends of the base material sandwich the spacer, and the intermediate product becomes annular. Consequently, the base material of the shaft seal, which becomes the finished product from the intermediate product, has a gap at one point in its circumferential direction. When mounting the shaft seal to the inner circumferential surface of the housing, the gap allows the shaft seal to be elastically deformed in the diameter-reducing direction, making the mounting process to the housing easier.

[0021] (10) The shaft seal comprises an annular base material having a gap at one location in the circumferential direction, and a fiber member located on the inner circumference side of the base material. The outer surface of the base material has grooves at two separate locations along its circumferential direction, parallel to the center line of the base material, and the grooves are positioned symmetrically with respect to a virtual plane passing through the gap and the center line. The shaft seal is obtained by any one of the manufacturing methods described in (1) to (9) above. The outer circumferential surface of the base material of the shaft seal has grooves in two places. The shaft seal is used by being mounted on the inner circumferential surface of the housing. The grooves facing the inner circumferential surface of the housing may function to prevent rotation with the rotating shaft.

[0022] <Details of the embodiment> Preferred embodiments will be described below with reference to the drawings. [Shaft seal configuration] Figures 1 and 2 are schematic diagrams showing one embodiment of the shaft seal of the present invention. Figure 1 is a view of the shaft seal 10 from a direction along the center line C, and Figure 2 is a cross-sectional view when cut by a plane including the center line C. The shaft seal 10 has an annular base material 11 and a fiber member 12 located on the inner circumference side of the base material 11. The shaft seal 10 has an adhesive layer 13 that adheres the fiber member 12 to the base material 11. The base material 11 is annular, but has a gap 14 at one location in the circumferential direction of the base material 11. The thickness T of the base material 11 is constant around its entire circumference. The layer thickness H of the free-state fiber member 12 is constant around its entire circumference.

[0023] The shaft seal 10 of this embodiment (see Figure 3) prevents powders such as toner and carrier present inside the device K1 from leaking out to the outside of the device K2 through the shaft portion 8 of the rotating body 7. The shaft seal 10 is used by being mounted on the inner circumferential surface 901 of the housing 9 of the device. The fibrous member 12 of the shaft seal 10 slides in contact with the outer circumferential surface 81 of the shaft portion 8. This prevents the powder from leaking out of the housing 9.

[0024] Before the shaft seal 10 is installed in the housing 9 (i.e., in its free state), the outer diameter D1 of the annular base material 11 is larger than the inner diameter D2 of the inner circumferential surface 901 of the housing 9. Therefore, when installing the shaft seal 10 onto the inner circumferential surface 901, the gap 14 in the base material 11 causes the shaft seal 10 to elastically deform in the diameter-reducing direction. The gap 14 facilitates the installation of the shaft seal 10 onto the housing 9. Once installed on the inner circumferential surface 901, the shaft seal 10 becomes tightly attached to the inner circumferential surface 901 due to the elastic restoring force of the base material 11.

[0025] The base material 11 is made of a material that is elastically deformable and plastically deforms beyond its elastic range. In this embodiment, the base material 11 is made of metal, specifically aluminum. The base material 11 may be made of a material other than metal, and may be made of resin. The fiber member 12 in this embodiment is made of pile. In particular, the fiber member 12 is made of a pile fabric or pile knit fabric including cut pile. The fiber member 12 is made of an aggregate of microfibers. The fiber member 12 may be made of something other than pile, such as felt or non-woven fabric.

[0026] In this disclosure, the direction along the center line C of the annular shaft seal 10, and the direction parallel to the center line C, are defined as the axial direction of the shaft seal 10. The direction perpendicular to the center line C is defined as the radial direction of the shaft seal 10. The direction along the circle centered on the center line C is defined as the circumferential direction of the shaft seal 10. The axial, radial, and circumferential directions of the mold 50 (see, for example, Figure 9) for manufacturing the shaft seal 10, which will be described later, are also defined with respect to the completed shaft seal 10.

[0027] [Manufacturing of shaft seals] Figures 4 to 9 are diagrams illustrating the manufacturing method of the shaft seal 10. The shaft seal 10 is manufactured from an intermediate product 19 which is a straight strip (see Figure 4). The intermediate product 19 has a strip-shaped base material 11 and a fiber member 12 located on the first surface 111 side of the base material 11. The base material 11 of the initial intermediate product 19 shown in Figure 4 is a straight strip. From the aforementioned intermediate product 19, a first mold 20 having a first recess 21, a second mold 30 having a second recess 31, and a pin 40 are used to manufacture an annular shaft seal 10 (see Figure 9). [Configuration of mold 50] A mold 50 used in the manufacture of the shaft seal 10 will now be described. The mold 50 has a first mold 20, a second mold 30, and a pin 40. In this embodiment, the first mold 20 is a lower mold installed at the bottom of a mold frame (not shown), and the second mold 30 is an upper mold located above the first mold 20. The pin 40 is located between the first mold 20 and the second mold 30.

[0028] The first type 20 has a first recess 21 that opens upward. The first recess 21 has a first concave arc surface 22 that follows the shape of a circle. As will be explained later, the first recess 21 further has support surfaces 28, 28 connected to each side of the first concave arc surface 22. In this embodiment, the first mold 20 is supported on the mold frame (not shown) so as to be able to move up and down. The first mold 20 moves up and down by an actuator (not shown). The mold frame is fixed to a device stand (not shown).

[0029] The second type 30 has a second recess 31 that opens downward. The second recess 31 has a second concave arc surface 32 that follows the shape of a circle. As will be explained later, the second recess 31 further has guide surfaces 36, 36 that connect to both sides of the second concave arc surface 32. In this embodiment, the second mold 30 is supported on the mold frame (not shown) so as to be able to move up and down. The second mold 30 moves up and down by an actuator (not shown).

[0030] The second type 30 has a spacer 35 at the bottom 311 of the second recess 31. As will be explained in the later manufacturing method, in the second bending step (see Figures 8 and 9), both end faces 118, 118 of the base material 11 become able to contact the spacer 35.

[0031] The pin 40 is supported in the middle of the mold frame (not shown) in the vertical direction. In this embodiment, the first mold 20 rises and approaches the pin 40 (see Figure 5), and the second mold 30 descends and approaches the pin 40 (see Figures 6 to 9). When the first mold 20 and the second mold 30 are in their closest proximity (see Figure 9), the mold 50 has an inner circumferential surface 51 shaped like a circle, formed by the first concave arc surface 22 and the second concave arc surface 32. The pin 40 is located in the region including the center line 52 of the inner circumferential surface 51. As will be explained later, the base material 11 plastically deforms along its circular inner circumferential surface 51 and becomes circular.

[0032] In the above description, the pin 40 was assumed to be a fixed member that does not move in the vertical direction, but the pin 40 may move along the vertical direction (downward) and approach the first type 20. Alternatively, the pin 40 and the first type 20 may be configured to move along the vertical direction (upward) and approach the second type 30.

[0033] [Method for manufacturing shaft seals] The annular shaft seal 10 is manufactured as described above (see Figure 4) from an intermediate product 19 having a strip-shaped base material 11, using a first mold 20, a second mold 30, and a pin 40. The manufacturing method comprises a first bending step and a second bending step.

[0034] [First bending process] In the first bending process, as shown in Figure 4, the intermediate product 19 is placed on the first mold 20 such that the second surface 112 of the base material 11, opposite to the first surface 111, is in contact with the upper surface 25 of the first mold 20. The first bending process, as shown in Figures 4 and 5, involves bringing the first die 20 and the pin 40 close together and bending the strip-shaped base material 11 into a V-shape (approximately V-shape). Specifically, with the pin 40 positioned on the first surface 111 side (see Figure 4), the intermediate product 19 is sandwiched between the pin 40 and the first recess 21 (see Figure 5), and the intermediate product 19 is bent so that the central part 113 in the longitudinal direction of the strip-shaped base material 11 is the bending point.

[0035] In the first bending process, the pin 40 is brought into contact with the longitudinal central portion 113 of the strip-shaped base material 11 from the fiber member 12 side which is the first surface 111 side. The portion of the fiber member 12 corresponding to the central portion 113 of the base material 11 comes into contact with the convex arc surface 41 which is the lower surface of the pin 40. By bringing the first mold 20 and the pin 40 relatively close together, the intermediate product 19 is bent into a V shape. In the state after the first bending process shown in Figure 5 is completed, a portion of the V-shaped intermediate product 19 is located between the pin 40 and the first recess 21. This portion is the central part 113 of the base material 11 and the portion of the fiber member 12 provided in the central part 113 that contains fibers.

[0036] The first concave arc surface 22 of the first recess 21 is shaped along a circle. In contrast, the bent intermediate product 19 is V-shaped. As shown in Figure 5, the central part 113 of the base material 11 is in contact with the bottom 23 of the first concave arc surface 22, but the portion 116 of the intermediate part 115 of the base material 11 between the central part 113 and the end part 114, closer to the central part 113, may not be in contact with the first concave arc surface 22.

[0037] As shown in Figure 5, in the base material 11, the intermediate portion 117, which is the part near the end 114, contacts the edges 24 on both sides of the first recess 21. Then, both ends 192, 192 of the intermediate product 19, which has been bent in the first bending process, protrude from the first recess 21 toward the second recess 31 of the second mold 30.

[0038] As described above, in the first bending process, the central part 113 of the base material 11 is used as the bending point, and the edge 24 on the opening side of the first recess 21 is used as a fulcrum for the middle part 117 of the base material 11, and the bending process is carried out. As a result, the intermediate product 19 becomes V-shaped (approximately V-shaped). The bending point (central part 113) of the V-shaped base material 11 is located at the bottom 23 of the first recess 21, and both ends 192,192 of the intermediate product 19 protrude upward from the first mold 20.

[0039] The fiber member 12 is provided along the longitudinal direction of the strip-shaped base material 11 and extends over the entire width direction (perpendicular to the longitudinal direction) of the base material 11. As described above, the pin 40 (convex arc surface 41) contacts the portion of the fiber member 12 that corresponds to the central portion 113 of the base material 11, but does not contact the entire width of that portion, and may contact while leaving a portion of the width of that portion untouched. Therefore, as shown in Figure 5, a portion of the fiber member 12 hides a portion of the tip surface of the pin 40. This contact of the pin 40 with the fiber member 12 is the same in the second bending process.

[0040] [Second bending process] The second bending process is performed immediately after the first bending process. The second bending process involves bringing the combination of the first mold 20 and the pin 40 closer to the second mold 30 (see Figures 6 to 9) to make the V-shaped base material 11 circular. In other words, as shown in Figure 6, the V-shaped intermediate product 19, which has a portion located between the pin 40 and the first recess 21, is sandwiched between the first recess 21 and the second recess 31 to form an annular shape.

[0041] As described above, with the first bending process completed (see Figure 5), both ends 192, 192 of the V-shaped intermediate product 19 protrude above the first recess 21. In the second bending process, the second mold 30 is gradually brought closer to the combination of the first mold 20 and the pin 40. As a result, as shown in Figures 6 to 9, both ends 114, 114 of the base material 11 are brought into contact with the second recess 31, and the base material 11 is plastically deformed along the second concave arc surface 32 of the second recess 31 while moving along the second recess 31, and the base material 11 is plastically deformed along the first concave arc surface 22 of the first recess 21, thereby forming the intermediate product 19 into an annular shape.

[0042] As described above, the second type 30 has a spacer 35 at the bottom 311 of the second recess 31. When the base material 11 is plastically deformed along the second concave arc surface 32 of the second recess 31, with both ends 114, 114 of the base material 11 aligned with the second recess 31, both ends 114, 114 (both end faces 118, 118) sandwich the spacer 35, and the intermediate product 19 becomes annular (see Figure 9).

[0043] As a result, the base material 11 of the finished shaft seal 10 has a gap 14 at one location in its circumferential direction, as shown in Figure 1. As explained in Figure 3, when the shaft seal 10 is attached to the inner circumferential surface 901 of the housing 9, the gap 14 allows the shaft seal 10 to be elastically deformed in the diameter reduction direction, making the attachment work to the housing 9 easier.

[0044] [First bending process and second bending process] As described above, according to the first bending step of the manufacturing method of this embodiment (see Figures 4 and 5), an intermediate product 19 with a substantially V-shape is obtained, with the central part 113 in the longitudinal direction of the strip-shaped base material 11 as the bending point. With a portion of the intermediate product 19 positioned between the pin 40 and the first recess 21, the second bending process is performed (Figures 6 to 9), causing the intermediate product 19 to be sandwiched between the first recess 21 and the second recess 31, forming an annular shape. This results in the production of an annular shaft seal 10. The manufacturing method of this embodiment has two steps, a first bending step and a second bending step, but during this time, the intermediate product 19 is not removed from the first mold 20, and the first mold 20 and the pin 40 are not moved, and an annular shaft seal 10 can be obtained. The number of steps is reduced and the manufacturing efficiency can be improved. It is also suitable for automating the manufacturing of the shaft seal 10.

[0045] In the second bending process, the base material 11 is pressed and bent along its entire circumference by the first concave arc surface 22 and the second concave arc surface 32. As a result, the springback of the base material 11 is suppressed, and the intermediate product 19 takes on the desired annular shape. In contrast, in the case of conventional manufacturing methods (see Figures 12(C) to 12(D)), the W-shaped intermediate product 90 is locally bent at its inflection point 909. As a result, springback is likely to occur in the base material 91 of the intermediate product 90. This embodiment makes it possible to improve the dimensional accuracy of the manufactured shaft seal 10 compared to the conventional method.

[0046] In the manufacturing method of this embodiment, as shown in Figures 5 to 9, the second bending process begins without any change in the relative position between the pin 40 and the first recess 21 after the completion of the first bending process. In other words, the pin 40 used in the first bending process remains between the first recess 21 and the second recess 31 during the second bending process. As a result, the intermediate product 19 bent in the first bending process is positioned in the first recess 21 by the pin 40. Furthermore, the relative position between the first recess 21 and the pin 40 does not change from the completion of the first bending process to the completion of the second bending process. This makes it possible to prevent the intermediate product 19 from falling off the first mold 20 when moving from the first bending process to the second bending process.

[0047] [Regarding the shape of mold 50] The first type 20 (see Figure 4) has a main mold 26 and a sub-mold 27 which is a separate component from the main mold 26 and is attached to the main mold 26. Figure 10 is an exploded view of the main mold 26 and the sub-mold 27. The sub-mold 27 is mounted and positioned on the main mold 26. The sub-mold 27 is fixed to the main mold 26 by fastening members such as bolts. The main mold 26 has a first concave arc surface 22 that follows the shape of a circle, as described above, as part of the first recess 21. In the first bending process (see Figure 5), the first concave arc surface 22 is able to contact at least the central portion 113 of the base material 11. In the second bending process (see Figure 9), the first concave arc surface 22 contacts approximately half of the base material 11.

[0048] In Figure 10, the first concave arc surface 22 has a shape along a circle centered on the center line 52, and in this embodiment, it is an arc surface in the range of 180 degrees. The center line 52 is the center line of the inner circumferential surface 51 (see Figure 9) of the mold 50, which is formed by the first concave arc surface 22 of the first mold 20 and the second concave arc surface 32 of the second mold 30. The main mold 26 (see Figure 10) has recesses 56 adjacent to both sides of the first concave arc surface 22. Each of the two recesses 56 forms a space into which the guide portion 34 of the second mold 30 enters during the second bending process (see, for example, Figure 7). Of the main mold 26, the portion between the first concave arc surface 22 and the recess 56, that is, both ends 221, 221 of the first concave arc surface 22, taper towards the upper side which is the second mold 30 side, as shown in Figure 10.

[0049] The sub-mold 27 has a support surface 28 as another part of the first recess 21. The support surface 28 can contact the intermediate portion 117 between the central portion 113 and the end portion 114 of the base material 11 when the base material 11 is bent into a V shape during the first bending process (see Figure 5). The support surface 28 has a linear surface 281 that extends with tangential components at both side edges of the first concave arc surface 22 when the sub-type 27 is attached to the main type 26 (see Figure 4), and a convex small arc surface 282 that is continuous with the surface 281 (see Figure 10).

[0050] In the first bending process (see Figure 5), the middle portion 117 of the base material 11 comes into contact with either or both of these linear surfaces 281 and small arcuate surfaces 282. In other words, the linear surface 281 and the small arcuate surface 282 become the edges 24 on the opening side of the first recess 21, and act as fulcrums for the middle portion 117 of the base material 11 during the first bending process.

[0051] Thus, in the first bending process, when the intermediate product 19 is bent into a V-shape with the central part 113 of the base material 11 as the bending point, the support surface 28 of the sub-die 27 contacts the middle part 117 of the base material 11 and functions as a fulcrum for that middle part 117. As described above (see Figure 10), in the main mold 26, both ends 221, 221 of the first concave arc surface 22 become thin and weak in terms of strength. However, with the sub-mold 27, which is a separate part from the main mold 26, the thinned ends 221, 221 do not need to be used as fulcrums for the middle part 117 of the base material 11. The thinned ends 221, 221 of the first concave arc surface 22 are protected by the sub-mold 27.

[0052] The second type 30 (see, for example, Figure 4) has a mold body 33 and a pair of guide parts 34 that are integrated with the mold body 33. The mold body portion 33 has a second concave arc surface 32 that follows the shape of a circle, as described above, as part of the second recess 31. The second concave arc surface 32 has a shape that follows a circle centered on the center line 52 (see Figure 9), and in this embodiment, it is an arc surface in the range of less than 180 degrees. Each of the pair of guide sections 34 extends from the mold body 33 toward the first mold 20 and has a shape that gradually tapers toward its tip. During the second bending process (see Figures 7 to 9), the guide section 34 enters the recess 56 of the first mold 20.

[0053] The guide section 34 (see Figure 4) has a guide surface 36 as another part of the second recess 31. The guide surface 36 is a surface that extends with tangential components at both edges of the second concave arc surface 32. The distance between the pair of guide surfaces 36, 36 gradually widens toward the first mold 20 side. The distance between the pair of guide surfaces 36, 36 at their tips toward the first mold 20 is greater than the width dimension of the V-shaped intermediate product 19 (see Figure 6).

[0054] Therefore, during the second bending process, both ends 114, 114 of the base material 11 of the V-shaped intermediate product 19 come into contact with the second recess 31, which includes the guide surface 36. Furthermore, both ends 114, 114 of the base material 11 can plastically deform along the second recess 31 and along the second concave arc surface 32.

[0055] Figure 11 is an explanatory diagram of the pin 40 and its surroundings. Figure 11 shows the later stage of the second bending process shown in Figure 9, but the fiber member 12 covering the tip of the pin 40 has been omitted in order to explain the shape of the pin 40, etc. The pin 40 is a columnar member that is long along the axial direction of the annular axial seal 10. The pin 40 has a convex arc surface 41, a pair of side surfaces 42, 42, and an outer surface 43 on its outer circumferential surface.

[0056] The convex arc surface 41 has a shape along a virtual circle Q centered on a reference line. At the completion of the first bending process, the reference line coincides with the center line of the first concave arc surface 22, and in the second bending process, it coincides with the center line 52 of the inner circumferential surface 51 of the mold 50 formed by the first concave arc surface 22 and the second concave arc surface 32. The convex arc surface 41 is the surface of the fiber member 12 that contacts the portion 121 corresponding to the central part 113 in the longitudinal direction of the base material 11.

[0057] In the first bending process, the strip-shaped base material 11 is pressed and bent via the fiber member 12 by the convex arc surface 41 of the pin 40, and the central part 113 of the base material 11 becomes arc-shaped. The fiber member 12 located at the position corresponding to the central part 113 of the base material 11 is pressed with a certain force by the convex arc surface 41, but this is only a part of the fiber member 12 and only for a short time. Therefore, the restoring force of the aforementioned part of the fiber member 12 returns it to its original shape (free state) after the manufacturing of the shaft seal 10.

[0058] The pair of side surfaces 42, 42 of the pin 40 are located on both sides of the convex arc surface 41. Each of the pair of side surfaces 42, 42 is located on the reference line side (center line 52 side) of the virtual circle Q. In the first bending process, the base material 11 is bent into an annular shape by the first recess 21 and the second recess 31 in the second bending process. However, the sides 42, 42 of the pin 40 are prevented from making strong contact with the fiber member 12, so as not to crush the fiber member 12.

[0059] The outer surface 43 is located on the opposite side of the convex arc surface 41 from the reference line (across the center line 52) and between the pair of side surfaces 42, 42. The outer surface 43 is located on the reference line side (center line 52 side) of the virtual circle Q. Therefore, in the second bending process, the outer surface 43 of the pin 40 is prevented from making strong contact with the fiber member 12, and the fiber member 12 is not crushed.

[0060] The radius r of the convex arc surface 41 is smaller than the value obtained by dividing the radius R of the first concave arc surface 22 of the first recess 21 by the thickness T of the base material 11 (r <R-T)。 In this configuration, during the first and second bending processes, a gap e is created between the convex arc surface 41 of the pin 40 and the central portion 113 of the base material 11 along the first concave arc surface 22 of the first recess 21 (see Figure 11). This gap e is maintained as a layer of the compressed fiber member 12. The gap e prevents the fiber member 12 from being crushed too strongly.

[0061] Let's further explain the radius r of the convex arc surface 41. The radius r of the convex arc surface 41 is greater than the value obtained by dividing the radius R of the first concave arc surface 22 by the thickness T of the base material 11 (RT), and then further dividing that by 1 / 5 of the layer thickness H of the free-state fiber member 12 (see Figures 1 and 2) (r>RTt / 5).

[0062] In the first bending process, a portion of the fiber member 12 is pressed and compressed by the convex arc surface 41 of the pin 40, and the strip-shaped base material 11 is pressed and bent through the fiber member 12. The aforementioned configuration (r>RTt / 5) is set based on the fact that the fiber member 12 of the shaft seal 10 is compressed to a certain extent. If the shaft seal is made of a non-compressible material such as resin (meaning it cannot be crushed or is difficult to crush), then the above-mentioned configuration (r>RTt / 5) is not feasible.

[0063] [Regarding shaft seal 10] The shaft seal 10 manufactured by the above method will now be described. In the second bending process, as described above (see Figure 9), the mold 50 has a single circular inner surface 51 formed by the first concave arc surface 22 and the second concave arc surface 32. The base material 11 is bent into an annular shape along this inner surface 51. The first mold 20 has a first recess 21, and the second mold 30, which is separate from the first mold 20, has a second recess 31.

[0064] Regarding the annular shaft seal 10 manufactured using such a mold 50, the outer circumferential surface 119 of the base material 11 that contacts the inner circumferential surface 51 of the mold 50 (see Figure 1) has grooves 60 in two separate locations along its circumferential direction, parallel to the center line C of the base material 11. The grooves 60 are in symmetrical positions with respect to a virtual plane X. The virtual plane X is a plane that passes through a gap 14 provided at one location in the circumferential direction of the base material 11 and the center line C. The grooves 60 are formed on the outer circumferential surface 119 of the base material 11 at positions corresponding to the boundary between the first recess 21 and the second recess 31 of the mold 50. The grooves 60 are lines that appear due to a discontinuity in the outer circumferential surface 119 of the mold 50.

[0065] Let me explain the position of the groove 60 further. When the annular base material 11, which has a gap 14 in one place in the circumferential direction, is divided into four equal parts along the circumferential direction, the base material 11 is divided into a pair of first arc portions S1 located on the side of the gap 14 and a pair of second arc portions S2 located on the side of the central part 113 in the longitudinal direction of the base material 11, which is opposite to the gap 14.

[0066] In this case, the groove 60 is located within the range of the first arc portion S1 on the gap 14 side, or at the boundary between the first arc portion S1 and the second arc portion S2. As explained in Figure 3, the shaft seal 10 is used by being mounted on the inner circumferential surface 901 of the housing 9. The grooves 60 provided on the outer circumferential surface 119 of the base material 11 facing the inner circumferential surface 901 may function to prevent it from rotating together with the rotating body 7 (shaft portion 8) through an anchoring effect.

[0067] 〔others〕 The embodiments disclosed are illustrative in all respects and not restrictive. The scope of the present invention is not limited to the embodiments described above and includes all modifications within the scope equivalent to the configurations described in the claims. [Explanation of Symbols]

[0068] 10 Axis seal 11 Base material 12 Fiber members 13 Adhesive layer 14 gaps 19 Intermediate products 20 Type 1 21 First recess 22 First concave arc surface 26 Main Type 27 Subtype 28 Support surface 30 Type 2 31 Second recess 32 Second concave arc surface 35 Spacers 40 pins 41 Convex arc surface 42 Side view 43 Exterior 52 Center line (reference line) 60 Suji 111 Front page 113 Central part 114 End 117 Middle part 119 Outer surface 311 Bottom C center line H Fiber member layer thickness Q Virtual Yen R is the radius of the first concave arc surface. T: Thickness of the base material X virtual plane r is the radius of the convex arc surface.

Claims

1. A method for manufacturing an annular shaft seal from an intermediate product having a strip-shaped base material and a fiber member located on the first surface side of the base material, comprising a first type having a first recess, a second type having a second recess, and a pin, A first bending step involves positioning the pin on the first surface side, sandwiching the intermediate product between the pin and the first recess, and bending the intermediate product such that the central part in the longitudinal direction of the strip-shaped base material is the bending point. A second bending step involves sandwiching the intermediate product, which has a portion located between the pin and the first recess, between the first recess and the second recess to form an annular shape. Having, A method for manufacturing shaft seals.

2. The ends of the base material of the intermediate product that has been bent by the first bending process protrude from the first recess toward the second recess. In the second bending process, While bringing both ends into contact with and along the second recess, the base material is plastically deformed along the second concave arc surface, which has a circular shape along the second recess, The base material is plastically deformed along the first concave arc surface, which has a circular shape in the first recess, to form the intermediate product into an annular shape. A method for manufacturing a shaft seal according to claim 1.

3. The second bending process is started without changing the relative position between the pin and the first recess from the time of completion of the first bending process. The method for manufacturing a shaft seal according to claim 2.

4. The aforementioned pin is, Among the fiber members, a convex arc surface that contacts the portion corresponding to the central part in the longitudinal direction of the strip-shaped base material, It has a pair of side surfaces located on both sides of the convex arc surface, The aforementioned convex arc surface has a shape along a virtual circle centered on the reference line, The method for manufacturing an axial seal according to any one of claims 1 to 3, wherein each of the pair of sides is a surface located on the reference line side of the virtual circle.

5. The pin has an outer surface located opposite to the convex arc surface, The method for manufacturing an axial seal according to claim 4, wherein the outer surface is a surface located on the reference line side of the virtual circle.

6. The pin has a convex arc surface that contacts the portion of the fiber member corresponding to the central part in the longitudinal direction of the strip-shaped base material. The first recess has a circular shape and a first concave arc surface that contacts the central part of the base material, The method for manufacturing an axial seal according to any one of claims 1 to 3, wherein the radius of the convex arc surface is smaller than the value obtained by dividing the radius of the first concave arc surface by the thickness of the base material.

7. The radius of the convex arc surface is greater than the value obtained by dividing the radius of the first concave arc surface by the thickness of the base material, and then further dividing that value by 1 / 5 of the layer thickness of the fiber member in its free state. The method for manufacturing a shaft seal according to claim 6.

8. The aforementioned Type 1 is, A main mold having a first concave arc surface that can contact the central part of the strip-shaped base material as part of the first recess, A sub-mold, which is a separate component from the main mold, has a support surface that can contact the intermediate portion between the central and end portions of the base material during the first bending process, as another part of the first recess, A method for manufacturing a shaft seal according to any one of claims 1 to 3, comprising having

9. The method for manufacturing a shaft seal according to any one of claims 1 to 3, wherein the second type has a spacer at the bottom of the second recess that allows both end faces of the base material to come into contact with it.

10. It comprises an annular base material having a gap at one point in the circumferential direction, and a fiber member located on the inner circumference side of the base material, The outer surface of the substrate has two grooves parallel to the center line of the substrate at two separate locations along its circumferential direction. The groove is located in a position symmetrical with respect to a virtual plane passing through the gap and the center line, forming an axial seal.

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