Manufacturing method of opening member

Abstract

To excellently insert a cover member into an opening.SOLUTION: A manufacturing method includes inserting a cover member attached to a fitting surface of a cover member into a substantially circular opening of an opening member. An inner peripheral part of the cover member is substantially elliptical, and a holding part of the cover member is held by an end part of the opening member and another member connected to the opening. A long diameter of an outer periphery of an inner peripheral part is equal to or larger than a diameter of the opening, and a short diameter of the outer periphery of the inner peripheral part is less than a diameter of the opening. A length of the outer periphery of the inner peripheral part is equal to or less than a length of a circumference of the opening. A first virtual line of the fitting surface shows an inner peripheral part of the cover member, and a second virtual line of the fitting surface shows the opening when inserting the cover member. A positioning part is disposed inside the first and second virtual lines on the fitting surface, and the positioning part is close to a plurality of specific places of the first virtual line.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present disclosure relates to a method for manufacturing an opening member. [Background technology]

[0002] Turbochargers of vehicle engines and parts used around them are required to have high-temperature oxidation resistance because they are exposed to high-temperature exhaust gas, and are also required to have cyclic oxidation resistance because they are repeatedly heated and cooled.In response to this, Patent Document 1 discloses a technology for improving the heat resistance of an exhaust pipe by providing a cover member at the opening of the exhaust pipe into which exhaust gas from the turbocharger flows in, and covering the area around the opening on the inner peripheral surface of the exhaust pipe. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-181467 A Summary of the Invention [Problem to be solved by the invention]

[0004] The cover member is a ring-shaped member and includes an inner peripheral portion that covers the inner peripheral surface of the exhaust pipe, and a clamping portion that extends outward from the end of the inner peripheral portion. The cover member is first inserted into the opening of the exhaust pipe so that the inner peripheral portion covers the inner peripheral surface of the exhaust pipe. After that, the upstream exhaust pipe is fastened to the exhaust pipe opening into which the cover member has been inserted by a V-clamp or the like, and at that time, the clamping portion of the cover member is clamped by the end faces surrounding the opening of the exhaust pipe.

[0005] In one aspect of the present disclosure, it is desirable to provide a good insertion of the cover member into the opening. [Means for solving the problem]

[0006] One aspect of the present disclosure is a method for manufacturing an aperture member having a substantially circular opening provided at an end, comprising attaching a cover member to an attachment surface of a jig and inserting the cover member attached to the attachment surface of the jig into the opening. The cover member has an inner periphery and a clamping portion. The inner periphery is a ring-shaped portion that is substantially elliptical, and when the cover member is inserted into the opening, its outer periphery faces the inner periphery surrounding the internal space of the aperture member that communicates with the opening. The clamping portion is a portion that spreads outward from the end of the inner periphery and is clamped between the end of the aperture member and another member connected to the opening. The major axis of the outer periphery of the inner periphery is equal to or longer than the diameter of the opening, and the minor axis of the outer periphery of the inner periphery is shorter than the diameter of the opening. The length of the outer periphery of the inner periphery is equal to or shorter than the circumference of the opening. First and second imaginary lines can be set on the mounting surface, the first imaginary line indicating an inner periphery of the cover member attached to the mounting surface, the second imaginary line indicating an opening for inserting the cover member attached to the mounting surface, and the center of the inner periphery indicated by the first imaginary line and the center of the opening indicated by the second imaginary line substantially coincide with each other. Positioning portions are provided on the mounting surface inside the first and second imaginary lines, the positioning portions are adjacent to a plurality of specific points on the first imaginary line, and at least two of the plurality of specific points face each other across the center of the first imaginary line and the center of the second imaginary line.

[0007] According to the above configuration, when the cover member is attached to the attachment surface of the jig, the positioning portion can appropriately position the cover member. In addition, since the positioning portion is located inside the second virtual line, the positioning portion can be prevented from interfering with the insertion of the cover member into the opening of the opening member using the jig. Therefore, the cover member can be smoothly inserted into the opening.

[0008] In one embodiment of the present disclosure, the multiple specific locations may be located around at least three intersections of the first virtual line and the second virtual line. According to the above configuration, the cover member can be appropriately positioned when the cover member is attached to the attachment surface of the jig.

[0009] In one embodiment of the present disclosure, the positioning portion may have two long portions extending along the long axis of the approximately elliptical inner circumference indicated by the first virtual line, and two short portions extending along the short axis.

[0010] According to the above configuration, the cover member can be appropriately positioned when the cover member is attached to the attachment surface of the jig. In one aspect of the present disclosure, the opening member may be an exhaust pipe mounted on a vehicle.

[0011] According to the above configuration, the cover member can be smoothly inserted into the opening of the exhaust pipe. [Brief description of the drawings]

[0012] [Figure 1] FIG. 4 is a cross-sectional view taken along the axis of the first and second exhaust pipes which are fastened together. [Diagram 2] 2 is an enlarged view of the surrounding area of ​​the cover member and the first edge portion in the cross-sectional view of FIG. 1. [Diagram 3] FIG. 4 is a front view of a first end portion of the first exhaust pipe with a cover member attached. [Figure 4] 11 is a front view of the first opening and the cover member before attachment to the first end portion. FIG. [Diagram 5] FIG. 4 is a side view of the pushing jig and the first exhaust pipe. [Figure 6] 11 is a top view of the pushing jig and the first exhaust pipe in the insertion step, viewed from the pushing jig side. FIG. [Figure 7] 11 is a cross-sectional view of a pushing jig and a first exhaust pipe in an insertion step. FIG. [Figure 8] FIG. [Figure 9] 13A and 13B are explanatory views of the cover member and the chamfered portion in the insertion process. [Figure 10] 13A and 13B are explanatory views of the cover member and the chamfered portion in the insertion process. [Figure 11] FIG. 11 is an explanatory diagram of a mounting surface in the first modified example. [Figure 12] 13 is an explanatory diagram of a mounting surface in the second modified example. FIG. [Figure 13]13 is an explanatory diagram of a mounting surface in Modification 3. FIG. [Figure 14] FIG. 13 is an explanatory diagram of a mounting surface in the fourth modified example. [Figure 15] FIG. 13 is an explanatory diagram of a mounting surface in the fifth modified example. [Figure 16] 13 is an explanatory diagram of a mounting surface in Modification 6. FIG. [Figure 17] 13 is an explanatory diagram of a mounting surface in Modification 6. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the embodiments of the present disclosure are not limited to the following embodiments, and various forms may be adopted as long as they fall within the technical scope of the present disclosure.

[0014] [1. First exhaust pipe] The first exhaust pipe 1 constitutes a flow path for exhaust gas from an engine of a vehicle (see FIG. 1). As an example, the first exhaust pipe 1 is fastened by a V-clamp 5 to the downstream side of a second exhaust pipe 3 (in other words, another member) that discharges exhaust gas from a turbocharger. The first exhaust pipe 1 is also configured to accommodate a purification member (for example, a catalyst or a filter) that purifies the exhaust gas.

[0015] The first and second exhaust pipes 1, 3 may be made of austenitic steel material having heat resistance, for example. However, the first and second exhaust pipes 1, 3 are not limited to being made of austenitic steel material, and may be made of other steel material having heat resistance. Furthermore, the second exhaust pipe 3 may be made of a material having higher heat resistance than the material making up the first exhaust pipe 1.

[0016] The first exhaust pipe 1 includes a first end portion 10, a first opening 11, a first flange portion 12, and a cover member 2, which will be described later (see FIGS. 1 to 3). The first opening 11 is a substantially circular opening located at the first end 10 of the first exhaust pipe 1, and communicates with the internal space 16 of the first exhaust pipe 1. The first opening 11 is located upstream in the flow direction of exhaust gas in the first exhaust pipe 1, and is connected to the second exhaust pipe 3. Hereinafter, a straight line that passes through the center of the first opening 11 and is perpendicular to the first opening 11 will be referred to as an axis 11A.

[0017] The first flange portion 12 is provided at the first end portion 10 of the first exhaust pipe 1 and is used for fastening to the second exhaust pipe 3. The first end portion 10 surrounds the first opening 11 and extends in a plane in a direction perpendicular to the axis 11A of the first opening 11. The first end portion 10 includes a groove portion 13 and a first edge portion .

[0018] The first edge 14 is a portion that protrudes from the first end 10 toward the second exhaust pipe 3 along the axis 11A, and is adjacent to and surrounds the first opening 11. A clamping surface 14A located at the top of the first edge 14 extends in a plane in a direction perpendicular to the axis 11A. The inner circumferential surface of the first edge 14 forms an inner circumferential surface 15 that surrounds the internal space 16 of the first exhaust pipe 1.

[0019] Also, a chamfered portion 14C is formed at the boundary between the clamping surface 14A and the inner peripheral surface 15 of the first edge portion 14 (see FIG. 2). The chamfered portion 14C is formed so as to surround the first opening 11, and is inclined so as to move away from the axis 11A as it approaches the first end portion 10. The chamfered portion 14C is inclined, for example, at 10 to 80 degrees, more preferably 45 degrees, with respect to the axis 11A.

[0020] Groove 13 is a groove-shaped portion provided in first end 10, and surrounds first opening 11. Groove 13 is provided adjacent to the outside of first edge 14, and outer circumferential surface 14B of first edge 14 protrudes along axis 11A from the bottom surface of groove 13. A ring-shaped gasket 4 is disposed in groove 13 to seal the gap between first opening 11 and second opening 31.

[0021] [2. Second exhaust pipe] The second exhaust pipe 3 includes a second end 30, a second opening 31, and a second flange portion 32 (see FIGS. 1 and 2).

[0022] The second opening 31 is located at the second end 30 of the second exhaust pipe 3. In addition, the second opening 31 is connected to the first opening 11 of the first exhaust pipe 1, and has the same shape as the first opening 11 (for example, substantially circular).

[0023] The second flange portion 32 is provided at the second end portion 30 of the second exhaust pipe 3 and is used for fastening to the first exhaust pipe 1. The second end portion 30 surrounds the second opening 31 and extends in a plane in a direction perpendicular to the axis 11A of the first opening 11 of the first exhaust pipe 1 connected to the second opening 31. The second end portion 30 includes a recess 33.

[0024] The recess 33 is formed in the second end 30 adjacent to and surrounding the second opening 31, and has a bottom surface 34 and a first inner circumferential surface 35. The bottom surface 34 is a portion that extends in a plane in a direction perpendicular to the axis 10A of the first opening 11 connected to the second opening 31, and is provided so as to go around the inner circumferential surface of the second exhaust pipe 3. In addition, the bottom surface 34 forms a step on the inner circumferential surface of the second exhaust pipe 3, and divides the inner circumferential surface into a first inner circumferential surface 35 and a second inner circumferential surface 36.

[0025] The first inner circumferential surface 35 is adjacent to the second opening 31 and surrounds the second opening 31. The first inner circumferential surface 35 is adjacent to the second inner circumferential surface 36 with the bottom surface 34 in between, and the diameter of the first inner circumferential surface 35 is larger than the diameter of the second inner circumferential surface 36.

[0026] [3. Cover material] The cover member 2 is provided at the first end 10 of the first exhaust pipe 1, and is clamped between the fastened first end 10 and the second end 30 of the second exhaust pipe 3 (see FIGS. 1 to 3). The cover member 2 is a ring-shaped member provided so as to surround the first opening 11, and includes a clamping portion 20 and an inner circumferential portion 21, with a cross section perpendicular to the circumferential direction being L-shaped.

[0027] The inner circumferential portion 21 is a flat ring-shaped member, and the width direction of the inner circumferential portion 21 approximately coincides with a direction perpendicular to the radial direction of the cover member 2. The outer circumferential surface 21B of the inner circumferential portion 21 faces a portion of the inner circumferential surface 15 of the first exhaust pipe 1 around the first opening 11. Specifically, the outer circumferential surface 21B of the inner circumferential portion 21 abuts against that portion or is disposed with a gap therebetween.

[0028] The clamping portion 20 is also a flat ring-shaped member, and the width direction of the clamping portion 20 approximately coincides with the radial direction of the cover member 2. The clamping portion 20 extends outward from an end portion in the width direction of the inner circumferential portion 21. The clamping portion 20 is clamped between the clamping surface 14A of the first edge portion 14 of the first exhaust pipe 1 and the bottom surface 34 of the recessed portion 33 of the second exhaust pipe 3.

[0029] The cover member 2 is made of a material that has higher heat resistance than the material that makes up the first end 10 of the first exhaust pipe 1, etc. Specifically, the cover member 2 may be made of a ferritic steel material, for example. Of course, the cover member 2 may be made of other materials. Furthermore, the heat resistance of the material that makes up the cover member 2 may be the same as the heat resistance of the material that makes up the first end 10 of the first exhaust pipe 1, etc., or it may be lower.

[0030] [4. Attaching the cover parts] Next, a method of attaching the cover member 2 to the first end 10 of the first exhaust pipe 1, in other words, a manufacturing method of the first exhaust pipe 1 with the cover member 2 attached to the first end 10, will be described.

[0031] [(1) Cover parts before and after installation] Before being attached to the first end portion 10, the cover member 2 has a substantially elliptical ring shape (see FIG. 4). Specifically, a major axis DL of the substantially ellipse formed by the outer peripheral surface 21B of the inner peripheral portion 21 is larger than the diameter D of the first opening 11, and a minor axis DS of the substantially ellipse is smaller than the diameter D of the first opening 11. The major axis DL may be equal to the diameter D. In addition, the circumference of the substantially ellipse, i.e., the circumferential length of the outer peripheral surface 21B, is shorter than the circumferential length of the first opening 11.

[0032] The attachment of the cover member 2 to the first end portion 10 is performed through a plurality of steps including an attachment step and an insertion step. The cover member 2 attached to the first end portion 10 is arranged along the circumference of the first opening 11 in a state in which elastic deformation occurs, and the shape of the cover member 2 becomes substantially circular, or substantially elliptical with the major axis DL shortened and the minor axis DS extended. Therefore, the elastic force of the cover member 2 encourages the position of the cover member 2 to be maintained.

[0033] For this reason, when the cover member 2 attached to the first end portion 10 becomes substantially elliptical, the outer peripheral surface 21B of the inner peripheral portion 21 at the long diameter portion 2A of the cover member 2 after attachment abuts against the inner peripheral surface 15 of the first exhaust pipe 1. On the other hand, the outer peripheral surface 21B at the short diameter portion 2B of the cover member 2 is disposed with a gap between it and the inner peripheral surface 15 of the first exhaust pipe 1.

[0034] Here, the long diameter portion 2A refers to a portion located around the end of the long diameter DL of the cover member 2 before attachment to the first end portion 10. The portion of the cover member 2 after attachment to the first end portion 10 that corresponds to the long diameter portion 2A of the cover member 2 before attachment is also described as the long diameter portion 2A. The short diameter portion 2B refers to a portion located around the end of the short diameter DS of the cover member 2 before attachment to the first end portion 10. The portion of the cover member 2 after attachment to the first end portion 10 that corresponds to the short diameter portion 2B of the cover member 2 before attachment is also described as the short diameter portion 2B.

[0035] [(2) Pressing jig] When attaching the cover member 2, a pressing jig 6 is used (see Figs. 5 to 7). The pressing jig 6 includes a cylindrical base 60, a rectangular thick plate-like bottom 61, and a positioning portion 63 (in other words, a core).

[0036] The outer surface of the bottom 61 is formed with first and second square faces facing each other in the thickness direction. The base 60 is provided so as to protrude from the first face of the bottom 61. Meanwhile, the second face of the bottom 61 is configured as an attachment face 62 to which the cover member 2 can be attached. As an example, the cover member 2 is attached to the attachment face 62 by magnetic force of a magnet arranged inside the bottom 61. At this time, the face of the clamping portion 20 of the cover member 2 that abuts against the second end 30 of the second exhaust pipe 3 abuts against the attachment face 62, and the inner periphery 21 protrudes from the attachment face 62. Of course, the cover member 2 can be attached to the attachment face 62 by various methods other than magnetic force, such as fastening or adhesion.

[0037] The positioning portion 63 is a portion for positioning the cover member 2 to be attached to the attachment surface 62. The positioning portion 63 is provided so as to protrude from the attachment surface 62 of the bottom portion 61, and the cover member 2 is attached to the attachment surface 62 with the positioning portion 63 located inside the inner periphery 21.

[0038] Here, first and second imaginary lines 64, 65 can be set on the mounting surface 62 (see Figs. 8, 111 to 17). The first imaginary line 64 indicates the inner periphery 21 of the cover member 2 attached to the mounting surface 62. The second imaginary line 65 indicates the circumference of the first opening 11 when the cover member 2 attached to the mounting surface 62 is inserted. In other words, the first imaginary line 64 is substantially elliptical, and the second imaginary line 65 is substantially circular, and the center of the inner periphery 21 indicated by the first imaginary line 64 and the center of the first opening 11 indicated by the second imaginary line 65 approximately coincide with each other.

[0039] As an example, the first and second imaginary lines 64, 65 refer to imaginary lines that are not actually provided on the mounting surface 62. However, the first and second imaginary lines 64, 65 may be lines that are actually provided on the mounting surface 62, and the first and second imaginary lines 64, 65 may be drawn on the mounting surface 62, for example.

[0040] The positioning portion 63 is provided in an area inside the first and second imaginary lines 64, 65 on the mounting surface 62, and is adjacent to at least two specific points 64A on the first imaginary line 64. In this disclosure, the concept of "adjacent" includes "contact." In other words, the positioning portion 63 adjacent to the specific point 64A has a slight gap with respect to the specific point 64A, or contacts the specific point 64A. The two specific points 64A face each other across the center of the first imaginary line 64 and the second imaginary line 65.

[0041] As an example, the positioning portion 63 is provided in a substantially rectangular region on the mounting surface 62 (see FIG. 8). That is, the positioning portion 63 has a substantially rectangular shape when viewed from the front of the mounting surface 62. The edge of the positioning portion 63 is formed with two long parts 63A extending substantially linearly along the direction of the major axis DL of the outer peripheral surface 21B of the inner peripheral portion 21 indicated by the first imaginary line 64, and two short parts 63B extending substantially linearly along the direction of the minor axis DS of the outer peripheral surface 21B. Hereinafter, the major axis DL and minor axis DS of the outer peripheral surface 21B of the inner peripheral portion 21 indicated by the first imaginary line 64 may be simply referred to as the major axis DL and minor axis DS, respectively.

[0042] Moreover, the four corners of the positioning portion 63 are each rounded and are close to the first virtual line 64 around the four intersections (hereinafter, virtual intersections 64B) between the first virtual line 64 and the second virtual line 65. That is, the four points close to these corners of the first virtual line 64 become specific points 64A, and these specific points 64A are located around the four virtual intersections 64B. Moreover, each specific point 64A faces another specific point 64A across the center (hereinafter, virtual center 64C) of the first and second virtual lines 64, 65.

[0043] [(3) Mounting and Insertion Process] In the attachment process, the cover member 2 is attached to the attachment surface 62 so as to surround the positioning portion 63 with the direction of the major diameter DL coinciding with the direction of the longitudinal portion 63A of the positioning portion 63 (see FIGS. 5, 7, and 8). At this time, the four corners of the positioning portion 63 are close to the inner circumferential surface 21A of the inner circumferential portion 21 of the cover member 2. As a result, the inner circumferential portion 21 of the cover member 2 is disposed along the first imaginary line 64.

[0044] In the subsequent insertion step, first, the first exhaust pipe 1 is fixed by a fixing jig (not shown) provided around the first end 10 of the first exhaust pipe 1. Then, the cover member 2 attached to the mounting surface 62 of the pressing jig 6 is brought close to the first opening 11 in a state where it is arranged at an insertion position determined based on the first exhaust pipe 1 (e.g., the first opening 11) as a reference, for example, with the virtual center 64C and the axis 11A coinciding, and the cover member 2 is inserted into the first opening 11 (see FIG. 7 ).

[0045] When the cover member 2 is inserted into the first opening 11, the cover member 2 arranged along the first imaginary line 64 is deformed into a substantially circular shape and extends along the second imaginary line 65 of the mounting surface 62. After insertion, by moving the pushing jig 6 away from the first opening 11, the cover member 2 is separated from the mounting surface 62 while remaining inserted into the first opening 11, thereby completing the attachment of the cover member 2.

[0046] During insertion of the cover member 2, the end of the inner periphery 21 at the long diameter portion 2A of the cover member 2 collides with the chamfered portion 14C of the first exhaust pipe 1 (see FIG. 9). The inner periphery 21 then enters the first opening 11 while deforming so as to be inclined inward due to the inclination of the chamfered portion 14C. Meanwhile, the inner periphery 21 at the short diameter 2B is located inside the chamfered portion 14C of the first exhaust pipe 1, and the end of the inner periphery 21 does not collide with the clamping surface 14A or the chamfered portion 14C, and enters the first opening 11 (see FIG. 10).

[0047] Note that, for example, the cover member 2 may be placed at the insertion position by adjusting the relative position between a mark (not shown) provided on the pushing jig 6 and a specific portion of the first exhaust pipe 1. Furthermore, as an example, the cover member 2 may be press-fitted into the first opening 11 by pressing the pushing jig 6 toward the first opening 11.

[0048] Moreover, by inserting the cover member 2 in the insertion position into the first opening 11, the inner circumferential portion 21 located at the long diameter portion 2A of the cover member 2 is disposed at a portion (hereinafter, weak portion) of the inner circumferential surface 15 of the first exhaust pipe 1 that is likely to be damaged. This encourages the inner circumferential portion 21 of the cover member 2 attached to the first opening 11 to abut against the weak portion, and it is possible to prevent the exhaust gas from directly hitting the weak portion. Specifically, for example, a portion where the flow of the drifted exhaust gas is likely to concentrate or a portion that is likely to become relatively hot may be the weak portion, or, if a wastegate is provided inside the second exhaust pipe 3, a portion where the flow of the exhaust gas flowing out from the wastegate is likely to concentrate may be the weak portion. In addition, for example, a portion of the first exhaust pipe 1 that is thin and has low strength or a portion where stress is likely to concentrate may be the weak portion. Also, for example, a case where a positioning portion including a recessed portion or a protruding portion is provided on a part of the circumferential direction of the cover member 2 is assumed. In this case, it is conceivable to provide a positioned portion including a convex portion or a concave portion, which is a portion corresponding to the circumferential positioning portion, on the edge portion of the first opening 11 of the first exhaust pipe 1. In such a case, the positioned portion becomes a weak portion.

[0049] On the other hand, the inner periphery 21 located at the short diameter portion 2B of the cover member 2 abuts against the inner periphery surface 15 of the first exhaust pipe 1, or is in a state where there is a gap between the inner periphery surface 15 and the inner periphery surface 15. Thereafter, the first end 10 of the first exhaust pipe 1, to which the cover member 2 is attached, and the second end 30 of the second exhaust pipe 3 are fastened together by, for example, a V-clamp 5 or the like.

[0050] [5. Modifications of positioning part] [(1) Variation 1] As shown in FIG. 11, the positioning portion 63 of the above embodiment may be provided in a substantially rectangular region in which the long and short sides are curved in an arc shape so that the center bulges outward. That is, the positioning portion 63 is substantially rectangular, but each long portion 63A and each short portion 63B are arc-shaped. The entire area of ​​each long portion 63A extends along the major axis DL of the first virtual line 64 and is close to each of two sections that face each other across the virtual center 64C. That is, the two sections are the specific points 64A. These specific points 64A are located around the four virtual intersections 64B. Note that a part of each long portion 63A may be close to the section. On the other hand, each short portion 63B is located away from the first and second virtual lines 64, 65.

[0051] Then, in the attachment process, the cover member 2 is attached to the attachment surface 62 so as to surround the positioning portion 63 with the direction of the long diameter DL approximately coinciding with the direction of the long portion 63A of the positioning portion 63. At this time, each long portion 63A is close to the inner circumferential surface 21A of the inner circumferential portion 21 located in a section including the short diameter portion 2B of the cover member 2. As a result, the inner circumferential portion 21 of the cover member 2 is disposed along the first imaginary line 64.

[0052] [(2) Variation 2] As shown in FIG. 12, the positioning portion 63 may be provided in a substantially elliptical region whose major and minor axes correspond to the major axis DL and minor axis DS of the first virtual line 64. The edge of the positioning portion 63 is provided with two long parts 63A that pass through the end of the minor axis and extend along the major axis DL of the first virtual line 64, and two short parts 63B that pass through the end of the major axis and extend along the minor axis DS of the first virtual line 64. Each long part 63A passes through the end of the minor axis DS of the first virtual line 64 and is close to each of two sections that face each other across the virtual center 64C in the first virtual line 64. In other words, the two sections are the specific points 64A. On the other hand, each short part 63B is located away from the first and second virtual lines 64, 65.

[0053] Then, in the attachment process, the cover member 2 is attached to the attachment surface 62 so as to surround the positioning portion 63 with the direction of the long diameter DL approximately coinciding with the direction of the long diameter of the positioning portion 63. At this time, each long portion 63A is close to the inner circumferential surface 21A of the inner circumferential portion 21 located at the short diameter portion 2B of the cover member 2. As a result, the inner circumferential portion 21 of the cover member 2 is disposed along the first imaginary line 64.

[0054] [(3) Variation 3] As shown in Fig. 13, the positioning portion 63 may be provided in a substantially elliptical region corresponding to the entire inside of the first and second virtual lines 64, 65. That is, each longitudinal portion 63A extending along the major axis at the edge of the positioning portion 63 is located inside the second virtual line 65 of the first virtual line 64, and is close to each of the entire areas of two sections facing each other across the virtual center 64C. That is, the two sections become the specific points 64A. Moreover, these specific points 64A are located around the four virtual intersections 64B. Note that a part of each longitudinal portion 63A may be close to the section.

[0055] Moreover, the two short parts 63B, which are parts extending along the short diameter at the edge of the positioning part 63, are close to the entire area of ​​each of the two sections of the second virtual line 65 located inside the first virtual line 64. Furthermore, the positioning part 63 is provided with an elastic part 63C corresponding to each short part 63B. The elastic part 63C is configured to displace the short part 63B toward the center of the positioning part 63 along the direction of the long diameter in response to pressure from the outside, and to return to its original position by elastic force. Specifically, the elastic part 63C may be, for example, a part made of an elastic material provided around the short part 63B in the positioning part 63, or a part having a spring or the like arranged inside the positioning part 63.

[0056] In the attachment process, the cover member 2 is attached to the attachment surface 62 so as to surround the positioning portion 63 with the direction of the long diameter DL approximately coinciding with the direction of the long portion 63A. At this time, each long portion 63A is close to the inner circumferential surface 21A of the inner circumferential portion 21 located in a section including the short diameter portion 2B of the cover member 2. As a result, the inner circumferential portion 21 of the cover member 2 is disposed along the first imaginary line 64.

[0057] Furthermore, when the cover member 2 is inserted into the first opening 11 in the insertion process, the cover member 2 is deformed and enters a state in which the cover member 2 extends along the second imaginary line 65 of the mounting surface 62, and each short portion 63B of the positioning portion 63 approaches the inserted cover member 2. At this time, the elastic portion 63C deforms each short portion 63B toward the center, making it easier to separate the cover member 2 from the mounting surface 62.

[0058] [(4) Variation 4] 14, the positioning portion 63 may be provided in a region of a substantially right-angled triangle on the mounting surface 62. That is, the positioning portion 63 is in the shape of a substantially right-angled triangle when viewed from the front of the mounting surface 62. The edge of the positioning portion 63 is formed with a long side portion 63A extending substantially linearly along the direction of the major axis DL of the first virtual line 64, and a short side portion 63B extending substantially linearly along the direction of the minor axis DS.

[0059] Moreover, the three corners of the positioning portion 63 are each rounded and are adjacent to the first virtual line 64 around different virtual intersections 64B. That is, the three points adjacent to these corners on the first virtual line 64 become specific points 64A, and these specific points 64A are located around the three virtual intersections 64B. Moreover, two of these specific points 64A face each other along a portion that forms the oblique side of the positioning portion 63 (hereinafter, oblique side portion 63D) with the virtual center 64C in between.

[0060] In the mounting process, the cover member 2 is mounted on the mounting surface 62 so that the three corners of the positioning portion 63 are adjacent to the inner circumferential surface 21A of the inner circumferential portion 21 of the cover member 2. As a result, the inner circumferential portion 21 of the cover member 2 is disposed along the first imaginary line 64.

[0061] [(5) Variation 5] 15, the positioning portion 63 of the fourth modification may be provided in a region of a substantially right-angled triangle in which each side is curved in an arc shape so that the center bulges outward. In other words, the positioning portion 63 is a substantially right-angled triangle, but the long side 63A, the short side 63B, and the oblique side 63D are arc-shaped.

[0062] The entire area of ​​the long portion 63A is close to one of the two sections extending along the major axis DL of the first virtual line 64. That is, the section of the first virtual line 64 is the specific portion 64A. A part of each long portion 63A may be close to the section. Also, the corner portion located between the short portion 63B and the oblique side portion 63D is close to the first virtual line 64. That is, two points on the first virtual line 64 close to the long portion 63A and the corner portion are the specific portion 64A. These specific portions 64A are located around the three virtual intersections 64B. Also, the specific portion 64A close to the corner portion faces the end of the specific portion 64A close to the long portion 63A across the virtual center 64C. On the other hand, the short portion 63B and the oblique side portion 63D are located away from the first and second virtual lines 64, 65.

[0063] Then, in the attachment process, the cover member 2 is attached to the attachment surface 62 so as to surround the positioning portion 63 with the direction of the long diameter DL approximately coinciding with the direction of the long portion 63A of the positioning portion 63. At this time, the long portion 63A and the corner between the short portion 63B and the oblique side portion 63D are close to the inner circumferential surface 21A of the inner circumferential portion 21 located in a section including the short diameter portion 2B of the cover member 2. As a result, the inner circumferential portion 21 of the cover member 2 is disposed along the first imaginary line 64.

[0064] [(6) Variation 6] 16, the positioning portion 63 may have four portions provided in four substantially circular regions on the mounting surface 62. In other words, each portion of the positioning portion 63 has a substantially circular shape when viewed from the front of the mounting surface 62.

[0065] Each portion (hereinafter, circular portion) of the positioning portion 63 is adjacent to the virtual intersection 64B and the first virtual line 64. That is, four points on the first virtual line 64 that are adjacent to these circular portions become specific portions 64A, and these specific portions 64A are located around the four virtual intersections 64B, respectively. Also, each specific portion 64A faces another specific portion 64A across the virtual center 64C.

[0066] In the mounting process, the cover member 2 is mounted on the mounting surface 62 so that the four circular portions of the positioning portion 63 are adjacent to the inner circumferential surface 21A of the inner circumferential portion 21 of the cover member 2. As a result, the inner circumferential portion 21 of the cover member 2 is disposed along the first imaginary line 64.

[0067] The number of circular portions in Modification 6 may be three as shown in Fig. 17, or may be two. When the number of circular portions is two, these circular portions are disposed so as to face each other across the virtual center 64C. In other words, the specific points 64A of the first virtual line 64 where these circular portions are adjacent are disposed across the virtual center 64C.

[0068] In addition, the number of circular portions may be five or more, in which case, four circular portions may be arranged as in FIG. 16, and further circular portions may be provided between the circular portions arranged along the major diameter DL so as to be close to the first virtual line 64.

[0069] [6. Effects] (1) According to the above embodiment, when the cover member 2 is attached to the attachment surface 62 of the pressing jig 6 in the attachment step, the cover member 2 is arranged to surround the positioning portion 63, so that the cover member 2 can be attached to the attachment surface 62 along the first imaginary line 64. This makes it possible to appropriately position the cover member 2. Furthermore, since the positioning portion 63 is located inside the second imaginary line 65 that indicates the first opening 11 of the first exhaust pipe 1, it is possible to prevent the positioning portion 63 from interfering with the insertion of the cover member 2 into the first opening 11 in the insertion step. This makes it possible to insert the cover member 2 into the first opening 11 well.

[0070] (2) In addition, around the long diameter portion 2A of the elliptical cover member 2, the inner periphery 21 is likely to come into contact with the inner periphery 15 of the first exhaust pipe 1, but around the short diameter portion 2B, a gap may occur between the inner periphery 21 and the inner periphery 15 of the first exhaust pipe 1. In contrast, exhaust gas is likely to drift downstream of the turbocharger. For this reason, if the flow of high-temperature exhaust gas concentrates around the short diameter portion 2B of the cover member 2, the exhaust gas may directly hit the inner periphery 15 of the first exhaust pipe 1, causing damage. Therefore, when inserting the cover member 2 into the first opening 11, it is desirable to adjust the orientation of the cover member 2 so that the periphery of the long diameter portion 2A of the cover member 2 covers the portion where the flow of exhaust gas concentrates.

[0071] In contrast, according to the above embodiment, by using the positioning portion 63 to position the cover member 2 at an appropriate position on the mounting surface 62, the cover member 2 can be reliably positioned at the insertion position by adjusting the relative position of the pushing jig 6 and the first exhaust pipe 1 in the insertion step. As a result, when the cover member 2 is inserted into the first opening 11, it is possible to encourage the peripheral portion of the long diameter portion 2A of the inner periphery 21 to abut against the chamfered portion 14C, or to be positioned at a weak portion on the inner periphery 15 of the first exhaust pipe 1.

[0072] (3) In the above embodiment and modifications 1, 3 to 6, the specific points 64A are located around at least three virtual intersections 64B. As a result, by disposing the cover member 2 so as to surround the positioning portion 63, the cover member 2 can be easily disposed along the first virtual line 64. Therefore, the positioning of the cover member 2 can be appropriately performed.

[0073] (4) In the above embodiment and modified examples 1 and 3, the positioning portion 63 has two long portions 63A and two short portions 63B. This makes it easier to grasp the appropriate mounting position of the cover member 2 based on the positioning portion 63, and by arranging the cover member 2 so as to surround the positioning portion 63, the cover member 2 can be more reliably arranged along the first virtual line 64. This allows the positioning of the cover member 2 to be performed appropriately.

[0074] 7. Other embodiments (1) The first end 10 of the first exhaust pipe 1 in the above embodiment may not be formed with the groove portion 13. Furthermore, the first end 10 may not be formed with the groove portion 13 and the first edge portion 14, and the first and second end portions 10, 30 may be formed as flat surfaces without any steps. Even in this case, the cover member 2 can be attached to the first end surface 10 and the clamping portion 20 of the cover member 2 can be clamped by the first and second end portions 10, 30 in the same manner as in the above embodiment.

[0075] (2) In the above embodiment, the cover member 2 is attached to the first opening 11 of the first end portion 10 located on the upstream side of the first exhaust pipe 1 which is connected to the downstream side of the second exhaust pipe 3 which discharges exhaust gas from the turbocharger. However, this is not limiting, and the cover member 2 may be attached to the opening of the end portion on the downstream side of the first exhaust pipe 1, or the cover member 2 may be attached in a similar manner to an exhaust pipe which is disposed away from the turbocharger, or an exhaust pipe which forms an exhaust gas flow path in which a turbocharger is not provided.

[0076] Furthermore, the cover member 2 may be attached in a similar manner to the opening of a tubular member mounted on a vehicle, or to the opening of an exhaust pipe or a tubular member other than an exhaust pipe that is not mounted on a vehicle. Also, the cover member 2 may be attached in a similar manner to the opening of an opening member that has an internal space, an opening on its outer surface that communicates with the internal space, and an end portion that surrounds the opening, without being limited to a tubular member.

[0077] (3) Multiple functions possessed by one component in the above embodiments may be realized by multiple components, or one function possessed by one component may be realized by multiple components. Also, multiple functions possessed by multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Also, part of the configuration of the above embodiments may be omitted. Also, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0078] [8. Technical Concepts Disclosed in This Specification] [Item 1] A method for manufacturing an aperture member having a substantially circular opening provided at an end portion, comprising the steps of: Attaching a cover member to a mounting surface of the jig; inserting the cover member attached to the mounting surface of the jig into the opening; Equipped with The cover member is an inner peripheral portion that is a ring-shaped portion having a substantially elliptical shape, and that is a portion in which an outer peripheral surface thereof faces an inner peripheral surface that surrounds an internal space of the opening member that communicates with the opening when the cover member is inserted into the opening; a clamping portion that is a portion that extends outward from an end of the inner periphery and is clamped between the end of the opening member and another member that is connected to the opening, The major axis of the outer periphery of the inner periphery is equal to or longer than the diameter of the opening, The minor axis of the outer periphery of the inner periphery is shorter than the diameter of the opening, The outer periphery of the inner periphery is equal to or less than the periphery of the opening, a first imaginary line and a second imaginary line can be set on the mounting surface, the first imaginary line indicates the inner periphery of the cover member attached to the mounting surface, the second imaginary line indicates the opening when the cover member attached to the mounting surface is inserted, and a center of the inner periphery indicated by the first imaginary line and a center of the opening indicated by the second imaginary line substantially coincide with each other; A positioning portion is provided on the mounting surface inside the first and second virtual lines, the positioning portion is adjacent to a plurality of specific points on the first virtual line, and at least two of the plurality of specific points face each other across the center of the first virtual line and the center of the second virtual line. A manufacturing method for opening materials.

[0079] [Item 2] A method for producing the opening member according to item 1, The specific points are located around at least three intersections of the first virtual line and the second virtual line. A manufacturing method for opening materials.

[0080] [Item 3] A method for producing the opening member according to item 1 or 2, The positioning portion has two long sides extending along the major axis of the inner periphery of the substantially elliptical shape indicated by the first imaginary line, and two short sides extending along the minor axis. A manufacturing method for opening materials.

[0081] [Item 4] A method for producing an opening member according to any one of items 1 to 3, The opening member is an exhaust pipe mounted on a vehicle. A manufacturing method for opening materials. [Explanation of symbols]

[0082] 1...first exhaust pipe, 10...first end portion, 11...first opening, 11A...axis line, D...diameter, 12...first flange portion, 13...groove portion, 14...first edge portion, 14A...clamping surface, 14B...outer peripheral surface, 14C...chamfered portion, 15...inner peripheral surface, 16...internal space, 2...cover member, 2A...long diameter portion, 2B...short diameter portion, 20...clamping portion, 21...inner peripheral portion, 2 1A...inner surface, 21B...outer surface, DL...long diameter, DS...short diameter, 6...pushing jig, 60...base, 61...bottom, 62...mounting surface, 63...positioning portion, 63A...long portion, 63B...short portion, 63C...elastic portion, 63D...hypothetic portion, 64...first virtual line, 64A...specific location, 64B...virtual intersection, 64C...virtual center, 65...second virtual line.

Claims

1. A method for manufacturing an aperture member having a substantially circular opening provided at an end portion, comprising the steps of: Attaching a cover member to a mounting surface of the jig; inserting the cover member attached to the mounting surface of the jig into the opening; Equipped with The cover member is an inner peripheral portion that is a ring-shaped portion having a substantially elliptical shape, and that is a portion in which an outer peripheral surface thereof faces an inner peripheral surface that surrounds an internal space of the opening member that communicates with the opening when the cover member is inserted into the opening; a clamping portion that is a portion that extends outward from an end of the inner periphery and is clamped between the end of the opening member and another member that is connected to the opening, The major axis of the outer periphery of the inner periphery is equal to or longer than the diameter of the opening, The minor axis of the outer periphery of the inner periphery is shorter than the diameter of the opening, The outer periphery of the inner periphery is equal to or less than the periphery of the opening, a first imaginary line and a second imaginary line can be set on the mounting surface, the first imaginary line indicates the inner periphery of the cover member attached to the mounting surface, the second imaginary line indicates the opening when the cover member attached to the mounting surface is inserted, and a center of the inner periphery indicated by the first imaginary line and a center of the opening indicated by the second imaginary line substantially coincide with each other; A positioning portion is provided on the mounting surface inside the first and second virtual lines, the positioning portion is adjacent to a plurality of specific points on the first virtual line, and at least two of the plurality of specific points face each other across a center of the first virtual line and a center of the second virtual line. A manufacturing method for opening materials.

2. A method for manufacturing the opening member according to claim 1, The specific locations are located around at least three intersections between the first virtual line and the second virtual line. A manufacturing method for opening materials.

3. A method for manufacturing the opening member according to claim 1 or 2, The positioning portion has two long sides extending along the major axis of the inner periphery of the substantially elliptical shape indicated by the first imaginary line, and two short sides extending along the minor axis. A manufacturing method for opening materials.

4. A method for manufacturing the opening member according to claim 1 or 2, The opening member is an exhaust pipe mounted on a vehicle. A manufacturing method for opening materials.

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