JP2019116957A - Reinforcement jig of joint part - Google Patents

Abstract

To provide a reinforcement jig of a joint part which can be easily attached to flange joint parts having any shapes and satisfy requirements of desired removal prevention force.SOLUTION: A reinforcement jig P of a joint part includes: a first pressing part 6B which presses an outer surface of a first flange part in which a head of a connection bolt or a nut is disposed; a second pressing part 5C which presses an outer surface of a second flange part as seen in a joint direction; a fastening mechanism 7 which fixes the first pressing part 6B and the second pressing part 5C in a manner that those pressing parts come close to each other in the joint direction; and a falling prevention mechanism 9 which is configured to be detachably attached to the first pressing part 6B and contacts with the head of the connection bolt or the nut from the radial inner side in a radial outer direction.SELECTED DRAWING: Figure 7

Description

  The present disclosure relates to a reinforcing jig that reinforces a joint between flanges projecting radially outward from the end of both cylindrical members.

  As the above-mentioned reinforcement jig, for example, according to Patent Document 1, a pair of holding members provided with pressing portions respectively abutted on flange joint portions of a pair of pipes (cylindrical members) and a bonding direction of the holding portions A configuration is disclosed that includes a fastening mechanism that pulls on and secures.

  In addition, a C-shaped dropout prevention arm is integrally formed on one of the holding members, the head being in contact with the head or nut of the connecting bolt connecting both flanges in the radial direction from the inside in the radial direction. There is. The fall-off preventing arm prevents the reinforcing jig from falling off the both flanges.

JP 2014-141995

  By the way, when reinforcing the joint between the flanges, it is necessary to satisfy the separation preventing force of 3DkN (D is the nominal diameter (the outer diameter of the pipe)) specified as the seismic joint standard. For example, in the case of piping with a nominal diameter of 500 mm, this separation prevention force is required to have a large separation prevention force such as 1500 kN.

  On the other hand, the number of heads or nuts of connection bolts connecting both flanges is determined for each size of the flanges, and the number of reinforcing jigs connected to the heads or nuts of the connection bolts is limited. In addition, there are pipings connected to both flanges provided with projections such as a plurality of ribs, so that the fall-off preventing arm may be in the way and installation of the reinforcement jig may become difficult. In that case, in order to secure the number of reinforcement jigs installed, it is necessary to cut off the drop-off prevention arm integrally formed on one of the holding members at the site and install the reinforcement jigs, resulting in a decrease in work efficiency. .

  Therefore, there is a demand for a reinforcing jig for a joint that can be easily mounted to a flange joint of any shape and that can satisfy a desired detachment prevention force.

  A characterizing feature of the reinforcing jig of the joint portion is the first flange projecting radially outward from the end of the first cylindrical member and the second flange projecting outward from the end of the second cylindrical member. A reinforcing jig of a joint mounted on a joint joined with a joint by a joint bolt, wherein a head of the joint bolt or an outer surface in a joint direction of the first flange on which a nut is disposed is pressed A first pressing portion, a second pressing portion for pressing the outer side surface of the second flange portion, and a fastening mechanism for fixing the first pressing portion and the second pressing portion close to each other in the joining direction; And a dropout prevention mechanism configured to be detachably attached to the first pressing portion and to be in contact with the head or the nut from the inside in the radial direction toward the outside in the radial direction.

  In this configuration, when the reinforcing jig is fixed to the flange joint, when the fastening mechanism is tightened, the first flange portion and the second flange portion move closer to each other by the fastening force of the fastening mechanism. As a result, the connection bolt can be further tightened, and the tightening torque on the flange joint can be increased. By alternately fastening the fastening mechanism and the connection bolt, a detachment preventing force is obtained for the flange joint.

  Furthermore, the dropout prevention mechanism in the present configuration is configured to be removable with respect to the first pressing portion. For this reason, the dropout prevention mechanism can be easily removed at a location where the installation of the reinforcing jig is difficult due to the dropout prevention mechanism being in the way. As a result, even if it is a flange joint of any shape, the number of reinforcement jigs installed can be secured to the maximum by properly using the reinforcement jig having the fall prevention mechanism and the reinforcement jig not having the fall prevention mechanism. Is possible. As described above, it is possible to provide a reinforcing jig of a joint which can be easily attached to a flange joint of any shape and which can satisfy a desired detachment preventing force.

  Another characteristic configuration is that the dropout prevention mechanism contacts an outer surface of the first pressing portion that is in contact with an outer surface opposite to a pressing surface that presses the outer surface of the first flange portion with respect to the joining direction. A base portion having a contact portion, a pair of side contact portions extending from both end portions of the outer surface contact portion and coming into contact with both side surfaces of the first pressing portion, and extending from one of the pair of side contact portions; An arm portion which abuts against the head or nut in the radial direction from the inside in the radial direction to the outside in the radial direction, and the other of the pair of side surface contact portions. And a prevention part.

  According to this configuration, the base of the dropout prevention mechanism has the outer surface contact portion and the pair of side surface contact portions, so that the cross section along the joining direction is formed in a U-shape. Further, the detachment prevention mechanism has an arm portion extending from one of the pair of side contact portions. That is, since the base and the arm portion can be integrally mounted from the outside of the first pressing portion, the mounting of the dropout prevention mechanism is extremely easy. Furthermore, since the detachment prevention mechanism is provided with the withdrawal prevention part on the other of the pair of side contact parts, it becomes possible to operate the withdrawal prevention part regardless of the arrangement of the arm part, and the working efficiency is enhanced. Can.

  Another characteristic configuration is that at least one of the outer surface and the both side surfaces of the first pressing portion is formed with a stepped portion that abuts against the base in the radially outer direction than the base.

  When securing the reinforcing jig to the flange joint, when the fastening mechanism is tightened, the arm abuts on the head or nut of the connection bolt. At this time, the arm portion tends to rotate in the radially inward direction by the reaction force received from the head or the nut of the connection bolt. And the force which moves the radial outward direction of a 1st flange acts on the base which the arm part extends. Since the first pressing portion of the present configuration has a step portion that abuts the base portion in a radially outward direction than the base portion, the step portion prevents movement of the base portion in the radially outer direction. Therefore, since the mounting posture of the falling prevention mechanism is stabilized, the falling prevention function of the reinforcing jig by the falling prevention mechanism can be reliably exhibited.

It is an exploded perspective view of both cylindrical members. It is a top view of both cylindrical members. It is a longitudinal cross-sectional view of both cylindrical members. It is a figure which shows schematic structure of the 1st clamping member which concerns on 1st embodiment. It is a figure which shows schematic structure of the 2nd clamping member which concerns on 1st embodiment. It is sectional drawing in the IV-IV line of FIG. 4 of the reinforcement jig | tool, and the VV line | wire of FIG. It is a perspective view of the omission prevention mechanism concerning a first embodiment. It is a perspective view which shows the mounting state of the reinforcement jig which concerns on 1st embodiment. It is an enlarged plan view of the reinforcement jig concerning a first embodiment. It is an enlarged plan view showing the process of fastening the connection bolt concerning a first embodiment. It is the schematic which shows the installation modification of the reinforcement jig which concerns on 1st embodiment. It is an enlarged perspective view which shows the 1st modification of the 1st press part which concerns on 1st embodiment. It is a top view which shows the 2nd modification of the drop-off prevention mechanism which concerns on 1st embodiment. It is a top view which shows the 3rd modification of the drop-off prevention mechanism which concerns on 1st embodiment. It is a front view of the 1st press part which shows the 4th modification of the drop-off prevention mechanism which concerns on 1st embodiment. It is a perspective view of the reinforcement jig concerning a second embodiment. It is an enlarged plan view which shows the mounting state of the reinforcement jig which concerns on 2nd embodiment. It is a longitudinal cross-sectional view which shows the mounting state of the reinforcement jig which concerns on 3rd embodiment.

  Hereinafter, an embodiment of a reinforcing jig of a joint according to the present disclosure will be described based on the drawings. In the present embodiment, as an example of the reinforcing jig P, both flanges 1A, 1B (in the radial outward direction protruding from the end of the water pipe 1, 1 (an example of the first tubular member and the second tubular member) The case of reinforcing the joint portion of the first flange portion and the second flange portion will be described. However, without being limited to the following embodiments, various modifications can be made without departing from the scope of the invention. The term "radial direction" used in the following description means the radial direction of both flanges 1A and 1B.

  1 to 3 show a flange joint part in the middle of a fluid piping system (pipeline). The flanges 1A and 1B of large diameter, which are respectively formed in the shape of a disc from the ends of the cast iron water pipes 1 and 2 which are an example of fluid pipes, project radially outward from the plurality of connecting bolts 4A and It is connected by a nut 4B (in the present embodiment, 14 points each). In the present embodiment, the side where the nut 4B is located is the first flange portion 1A, and the side where the head 4a of the connection bolt 4A is located is the second flange portion 1B. Washers 4C and 4C intervene between the nut 4B and the first flange portion 1A and between the head 4a of the connection bolt 4A and the second flange portion 1B. Thus, the connection bolt 4A, the nut 4B, and the washers 4C and 4C constitute a connection mechanism for connecting the flanges 1A and 1B. The washers 4C and 4C may be omitted.

  A ring-shaped, sheet-like gasket 2 is interposed between the flanges 1A and 1B. In both flange portions 1A and 1B, a plurality of through holes 3 (14 points in this embodiment) penetrating in the flange joining direction (axial direction, hereinafter referred to as "joining direction") are equally spaced in the circumferential direction The connection bolt 4A is formed in these through holes 3, and the nut 4B is screwed and fixed to the tip end side of the male screw portion 4b of the connection bolt 4A. Both flanges 1A and 1B of the present embodiment are so-called RF type flanges provided with a flat seating surface at a position where the gasket 2 on the radially inner side of the through hole 3 is interposed.

  Hereinafter, in both of the flanges 1A and 1B, the surfaces on which the water pipe 1 projects are referred to as the outer surfaces 1a and 1a in the joining direction. Further, the radially outer side surfaces 1A and 1B of both flanges will be described as the outer peripheral surfaces 1c and 1c.

  As shown in FIGS. 4 to 10, the reinforcing jig P is detachably attachable to the first holding member 6 having the first pressing portion 6B for pressing the outer side surface 1a of the first flange portion 1A, and the first pressing portion 6B. And a second holding member having a second pressing portion 5C for pressing the outer side surface 1a of the second flange portion 1B. 5 and. The both pressing surfaces 6e and 5e of these pressing portions 6B and 5C, for example, are formed with fine irregularities or a rubber member is attached to the surfaces of both pressing surfaces 6e and 5e to form the flanges 1A and 1B. Friction processing is applied to the outer side surfaces 1a, 1a so as to generate frictional resistance. In addition, it is not necessary to give friction processing to both the press surface 6e, 5e, and the aspect of friction processing is not specifically limited, either.

  Further, the reinforcing jig P holds both the holding members 6 and 5 (both pressing surfaces 6e and 5e) in a state where the pressing surfaces 6e and 5e are in contact with the outer surfaces 1a and 1a of the flanges 1A and 1B, respectively. A fastening mechanism 7 is provided which pulls in (adjacent to) in the joining direction and fixes (see FIG. 6).

  The first holding member 6 is made of a metal material, and in a cross section, the inserted portion 6A having an outer surface 6a and an inner surface 6b formed in an elliptical bottomed cylindrical shape, and an inserted portion at one end of the inserted portion 6A. A first pressing portion 6B extending outward from one side surface of the outer surface 6a of the portion 6A and having a first pressing surface 6e (an example of a pressing surface) is integrally configured (see FIG. 4). ).

  Inside the inserted portion 6A, a cylindrical inner space 6c for receiving an insertion portion 5A of the second holding member 5 described later along the joining direction is formed. That is, when the reinforcing jig P is attached to both the flanges 1A and 1B, the insertion portion 5A is formed in the second holding member 5 at a position radially outward of the outer peripheral surface 1c of the first flange 1A. The first holding member 6 is formed with an inserted portion 6A for receiving the inserted portion 5A inside along the joining direction (see FIGS. 6 and 8).

  The cylindrical internal space 6c is formed in an elliptical shape in a cross sectional view, and is formed slightly larger than the elliptical insertion portion 5A in a cross sectional view. Therefore, the shape perpendicular to the joining direction of the outer surface 5a of the insertion portion 5A and the inner surface 6b of the insertion portion 6A is the insertion direction (cylindrical shape when the insertion portion 5A is inserted into the cylindrical internal space 6c of the insertion portion 6A It is slidable in the longitudinal direction of the internal space 6c, but is formed such that relative rotation around the insertion direction (around the axis along the longitudinal direction of the cylindrical internal space 6c) is not possible.

  Further, in the cylindrical internal space 6c, the side opposite to the side where the first pressing portion 6B is formed is opened, and the bottom portion 6Aa of the inserted portion 6A is formed on the side where the first pressing portion 6B is formed. It is done. The bottom portion 6Aa of the inserted portion 6A is formed by inserting two insertion holes 6d1 and 6d2 into which the male screw portions 7a1 and 7b1 of two adjacent fastening bolts 70A and 70B can be inserted and the head portions 7a2 and 7b2 can not be inserted. (See FIG. 4 cross section, FIG. 6). In the state where male screw parts 7a1 and 7b1 of fastening bolts 70A and 70B are inserted into insertion holes 6d1 and 6d2, a predetermined amount is provided between the outer peripheral surface of male screw parts 7a1 and 7b1 and the inner peripheral surface of insertion holes 6d1 and 6d2. A gap is formed (see FIG. 6).

  The first pressing portion 6B is formed in a slightly tapered shape in plan view (see a plan view in FIG. 4), and has a tapered shape so that both side surfaces 6h become closer to the tip. Further, the surface of the first pressing portion 6B that faces the outer side surface 1a of the first flange portion 1A is formed as a first pressing surface 6e perpendicular to the outer surface 6a of the inserted portion 6A (FIG. 4, cross-sectional view, See Figure 6). Furthermore, the first pressing surface 6e of the first pressing portion 6B pressing the outer surface 1a of the first flange portion 1A is perpendicular to the outer surface 6g opposite to the bonding direction and the outer surface 6g and is opposed to each other On both side surfaces 6h, an outer diameter step portion 6i (an example of a step portion) which abuts on the base 9A in a radially outward direction than the base 9A of the falling-off preventing mechanism 9 described later is formed (see FIGS. 4 and 6) . The outer diameter step portion 6i may be provided on any one of the outer surface 6g and both side surfaces 6h of the first pressing portion 6B.

  The detachment prevention mechanism 9 includes a base 9A having a U-shaped cross section having an outer surface contact portion 91 and a pair of side surface contact portions 92, an arm portion 9B extending from one of the pair of side surface contact portions 92, and a pair And a withdrawal prevention portion 9C provided on the other side of the side contact portion 92 to prevent the detachment prevention mechanism 9 (the base 9A and the arm 9B) from coming off (see FIG. 7).

  The outer surface contact portion 91 is in contact with the outer surface 6g of the first pressing portion 6B and in contact with the outer radial step portion 6i of the first pressing portion 6B. The pair of side contact portions 92 extend from both ends of the outer surface contact portion 91, contact with both side surfaces 6h of the first pressing portion 6B and contact with the outer step portion 6i of the first pressing portion 6B. . The arm portion 9B is an L-shaped or C-shaped member extending from one of the pair of side contact portions 92, and abuts against the nut 4B in the radial direction from the radially inner side (see FIG. 8). ). The arm 9B is formed so as to surround at least a part of the nut 4B screwed to the connection bolt 4A (see FIG. 9). Further, in the longitudinal sectional view, the surface of the arm 9B facing the outer side surface 1a of the first flange 1A has a gap from the first flange 1A at the time of mounting, from the first pressing surface 6e. Are also retired (see Figure 6). The first holding member 6 and the second holding member 5 may be mounted oppositely, and the arm portion 9B may be brought into contact with the head portion 4a of the connection bolt 4A, and is not particularly limited.

  The extraction preventing portion 9C includes a through hole 92a of the pair of side surface contact portions 92, a retaining screw 95 screwed into the through hole 92a, and a first pressure opposite to the other of the pair of side surface contact portions 92. It is formed on the side surface 6h of the portion 6B, and is constituted by a hole 96 into which the retaining screw 95 is inserted (see FIG. 7). The hole 96 in the present embodiment is formed as an oblong notch in which the side of the outer surface 6g of the first pressing portion 6B of the side contact portion 92 is closed and the side of the pressing surface 6e is opened. By closing the side of the outer surface 6g of the first pressing portion 6B in the hole portion 96, the closed portion abuts against the retaining screw 95 so that the base 9A and the arm 9B are separated from the first pressing portion 6B. It is prevented. Further, the side wall of the hole 96 abuts against the retaining screw 95, so that the base 9A and the arm 9B are prevented from being separated from the first pressing portion 6B. Although the retaining screw 95 is constituted by a double screw bolt, a bolt with a head, etc., it may be constituted by a retaining pin. Further, the hole 96 may be formed in a round hole or a square hole without being formed in a long hole shape.

  The arm 9B of the detachment prevention mechanism 9 has another portion of the thickness of the edge 9Ba that abuts at least a part of the nut 4B so as to withdraw in the joining direction (toward the first flange 1A) with respect to the nut 4B. It is set smaller than that (see FIGS. 7 to 9). In particular, in the edge 9Ba of the arm 9B in the present embodiment, the step 9Bc stepped down toward the first flange 1A is formed from the connection between the base 9A and the arm 9B to the tip 9Bb. ing. That is, a notch having an L-shaped cross section is formed in the edge portion 9Ba radially inward so as to retract toward the first flange portion 1A more than the top surface 9Bd of the arm portion 9B. The notch of the edge 9Ba is set to a size that allows insertion of a tightening tool R such as a ratchet wrench for tightening the nut 4B (see FIGS. 9 to 10). If such a step 9Bc (notch) is formed, a concave gap is formed between the side surface of the nut 4B and the side wall of the step 9Bc, so that the tightening tool R can be easily inserted. It is easy to hook the tip of R to the nut 4B.

  Further, the edge 9Ba is formed in an arc shape, and is in point contact with the apex of the hexagonal nut 4B. The edge 9Ba may be in surface contact with the washer 4C, or the nut 4B may be formed in an arc shape to make the edge 9Ba in surface contact, and is not particularly limited. In addition, the nut 4B may be configured in a polygonal shape other than a hexagon, or the edge 9Ba may be configured in a shape along the outer shape of the nut 4B.

  As a result, even when distortion, deformation or relative displacement occurs in both flanges 1A and 1B due to its own weight or earthquake etc., the fall-off preventing mechanism 9 abuts on the nut 4B securely, so that the reinforcing jig P It is possible to more reliably prevent the flanges 1A and 1B from falling off.

  The second holding member 5 is made of a metal material, and the outer surface 5a has an elliptical shape in a cross sectional view, and the two inner peripheral surfaces 5b1 and 5b2 are formed in a cylindrical shape with a circular bottomed cylindrical shape in a cross sectional view. A portion 5A and a second pressing portion 5C extending outward from one end of the insertion portion 5A are integrally provided (see FIG. 5).

  Two cylindrical cylindrical internal spaces 5c1 and 5c2 are formed in the insertion portion 5A, through which the external threads 7a1 and 7b1 of the two fastening bolts 70A and 70B can be inserted (see FIG. 6). The inner diameters of the cylindrical inner spaces 5c1 and 5c2 are formed to be slightly larger than the outer diameters of the male screw parts 7a1 and 7b1 of the fastening bolts 70A and 70B.

  In the cylindrical internal spaces 5c1 and 5c2, the side on which the second pressing portion 5C is formed is formed open, and the side opposite to the side on which the second pressing portion 5C is formed is the male screw portion 7a1 of the fastening bolts 70A and 70B. Two female screw parts 5d1 and 5d2 in which 7b1 can be screwed are formed in an open state so as to penetrate the bottom of the insertion part 5A. That is, the female screw portions 5d1 and 5d2 are formed at the end portions on the inserted portion 6A side in the inner peripheral surfaces 5b1 and 5b2 of the cylindrical inner spaces 5c1 and 5c2 in the insertion portion 5A. The space between these two female screw parts 5d1 and 5d2 is filled with a metal material. Therefore, even when a large tightening torque of the fastening bolts 70A and 70B acts on the female screw parts 5d1 and 5d2, breakage of the insertion part 5A can be prevented.

  The second pressing portion 5C is formed in a slightly tapered shape in plan view (see a plan view in FIG. 5), and is formed in a tapered shape which is inclined toward the female screw portions 5d1 and 5d2 as it goes to the tip end in the longitudinal cross section (See the section in Figure 5). Further, the tip end portion of the surface on the side of the female screw portions 5d1 and 5d2 of the second pressing portion 5C is formed as a second pressing surface 5e perpendicular to the outer surface 5a of the insertion portion 5A. In the present embodiment, step portions 5f are formed on both side surfaces of the second pressing portion 5C as in the first pressing portion 6B (see FIG. 6). By this, the pressing areas of the first pressing surface 6e and the second pressing surface 5e to the first flange portion 1A and the second flange portion 1B are equalized, and a uniform pressing force is applied along the joining direction. There is. The stepped portion 5f may be omitted, and both side surfaces of the second pressing portion 5C may be flush.

  As shown in FIGS. 6 to 7, the fastening mechanism 7 has a first fastening mechanism 7A and a second fastening mechanism 7B provided adjacent to the first fastening mechanism 7A. The first fastening mechanism 7A includes a first fastening bolt 70A which is inserted into the cylindrical internal space 5c1 of the insertion portion 5A from the outside of the insertion portion 6A through the insertion hole 6d1 and an inner circumferential surface 5b1 of the insertion portion 5A. It comprises the formed first female screw 5d1 and the first washer 8A interposed between the first fastening bolt 70A and the bottom 6Aa of the inserted portion 6A. Similarly, the second fastening mechanism 7B includes a second fastening bolt 70B which is inserted into the cylindrical internal space 5c2 of the insertion portion 5A from the outside of the insertion portion 6A through the insertion hole 6d2, and the inner periphery of the insertion portion 5A. A second internal thread portion 5d2 formed on the surface 5b2 and a second washer 8B interposed between the second fastening bolt 70B and the bottom 6Aa of the inserted portion 6A. The first washer 8A and the second washer 8B may be omitted.

  The first fastening bolt 70A has a first head 7a2 located outside the bottom 6Aa of the inserted portion 6A, and a first male screw 7a1 screwed to the first female screw 5d1 of the insert 5A. There is. Similarly, the second fastening bolt 70B includes a second head 7b2 located outside the bottom 6Aa of the inserted portion 6A and a second male screw 7b1 screwed on the second female screw 5d2 of the insertion portion 5A. Have. In the first fastening mechanism 7A, the first head 7a2 of the first fastening bolt 70A is disposed in the cylindrical internal space 5c1 in a detent state, and the nut disposed outside the bottom 6Aa of the inserted portion 6A is It may be configured to be screwed to the first male screw 7a1 of the first fastening bolt 70A, and the second fastening mechanism 7B may be configured in the same manner.

  In the present embodiment, the outer diameter size and the outer diameter shape of the nut 4B, the first head 7a2 of the first fastening bolt 70A, and the second head 7b2 of the second fastening bolt 70B are configured the same. Thereby, the tightening tool R of the ratchet wrench for increasing the tightening torque can also be used.

  Next, an operation process for mounting the reinforcing jig P on both flange portions 1A and 1B connected by the plurality of connection bolts 4A and the nuts 4B will be described.

  First, as shown in FIGS. 1 to 3, one existing bolt and nut (not shown) of both flanges 1A and 1B are removed and replaced with a connection bolt 4A and a nut 4B. This replacement is sequentially performed on all existing bolts and nuts.

  Then, as shown in FIGS. 7-8, there is a space where the arm 9B of the falling-off prevention mechanism 9 can be inserted between the outer peripheral surface of the water pipe 1 and the outer peripheral surface of the nut 4B (inner side in the radial direction of the nut 4B). If there is, the drop prevention mechanism 9 is attached to the first pressing portion 6B of the first holding member 6. When mounting the fall-off prevention mechanism 9, the U-shaped base 9A having the U-shaped cross section integrally formed with the arm 9B is brought close to the first pressing portion 6B from the outside, and the outer surface 6g of the first pressing portion 6B is The outer surface contact portion 91 and the side surface contact portion 92 are brought into contact with the side surfaces 6h. Then, the retaining screw 95 of the removal prevention portion 9C is screwed into the through hole 92a of the side contact portion 92, and is inserted into the hole 96 of the side surface 6h of the first pressing portion 6B. By this, the detachment prevention mechanism 9 is fixed to the first pressing portion 6B. At this time, since the dropout prevention mechanism 9 is provided with the withdrawal prevention portion 9C on the side surface 6h of the first pressing portion 6B opposite to the extending direction of the arm portion 9B, the arrangement space of the arm portion 9B is related. And the screw 95 can be operated.

  Then, the insertion portion 5A of the second holding member 5 is formed at a position radially outward of the outer peripheral surfaces 1c and 1c of both flange portions 1A and 1B, and the cylindrical inner portion of the inserted portion 6A of the first holding member 6 It inserts in the space 6c from a joining direction. At that time, since the outer surface 5a of the insertion portion 5A and the inner surface 6b of the insertion portion 6A are formed in an elliptical shape that can not relatively rotate in cross sectional view, the first pressing surface 6e of the first holding member 6 and the second pressing surface 6e It can be made to insert easily in the state positioned with the relative positional relationship of the expected which extended the 2nd press surface 5e of the clamping member 5 in the same direction.

  Next, the two fastening bolts 70A and 70B are inserted from the outside of the inserted portion 6A in the joining direction via the insertion holes 6d1 and 6d2 into the inside of the cylindrical internal space 6c and temporarily fixed. The engagement between the insertion portion 5A and the insertion portion 6A and the temporary fixing of the fastening bolts 70A and 70B are temporarily performed in the joining direction by the first pressing surface 6e of the first holding member 6 and the second pressing member 5 The distance from the pressing surface 5e is set to be slightly larger than the distance between the outer side surface 1a of the first flange portion 1A and the outer side surface 1a of the second flange portion 1B. That is, the size (insertion distance) of the overlapping portion between the insertion portion 6A and the insertion portion 5A in the joining direction and the distance between the first pressing surface 6e and the second pressing surface 5e can be set appropriately. . Therefore, even when the thickness is changed according to the nominal diameter and design pressure of both flanges 1A and 1B, the first holding member 6 and the second holding member 5 are adjusted by adjusting the size of the overlapping portion. The two flanges 1A and 1B can be fastened and fixed well.

  Subsequently, the reinforcing jig P is attached to both flanges 1A and 1B. At this time, the outer surface 6a of the inserted portion 6A on the side where the first pressing surface 6e extends is brought into partial contact with at least one of the outer peripheral surfaces 1c and 1c of both flanges 1A and 1B from the radially outer direction. Further, the drop prevention mechanism 9 of the first holding member 6 is in a state of being in contact or in proximity to the nut 4B in the radial outer direction from the inner side in the radial direction (see FIG. 9).

  The extension direction of the arm portion 9B of the dropout prevention mechanism 9 is a direction in which the first holding member 6 provided with the dropout prevention mechanism 9 rotates together when the fastening bolts 70A and 70B are rotated to the tightening side. It is set in the same direction. That is, from the side surface 6h of the first pressing portion 6B of the first holding member 6, the arm portion 9B of the fall-off preventing mechanism 9 tightens the tightening bolts 70A and 70B (in the present embodiment, the tightening bolt 70A is a right screw). Since it exists, it is formed to extend toward the clockwise direction centering on the insertion hole 6d.

  Thus, when the fastening bolts 70A and 70B are tightened, the arm 9B of the detachment prevention mechanism 9 tends to rotate radially inward by the reaction force received from the nut 4B. And the force to which it moves to radial outer direction acts on the base 9A which arm part 9B extends. At this time, since the first pressing portion 6B of the present embodiment has an outer diameter step portion 6i that abuts the base portion 9A in a radially outer direction than the base portion 9A, the diameter of the base portion 9A by the outer diameter step portion 6i The outward movement is blocked. Therefore, when the fastening bolts 70A and 70B are tightened, the arm 9B of the detachment prevention mechanism 9 abuts on the nut 4B to provide a rotational resistance, so the tightening operation is easy.

  When there is no space for inserting the arm 9B of the fall-off preventing mechanism 9 because the distance between the adjacent nuts 4B is narrow or there is no space for inserting the arm 9B of the fall-off preventing mechanism 9 inside the nut 4B in the radial direction. The reinforcement jig P is attached to both the flanges 1A and 1B without attaching the dropout prevention mechanism 9 to the first pressing part 6B of the first holding member 6. When there is no space for inserting the arm portion 9B of the drop prevention mechanism 9 inside the radial direction of the nut 4B, the drop prevention mechanism 9 is reinforced with the first press portion 6B of the first holding member 6 attached. The jig P may be turned upside down and reversely mounted on both flanges 1A and 1B. In this case, the dropout prevention mechanism 9 abuts or approaches the head portion 4a of the connection bolt 4A located at the second flange portion 1B from the radially inner side in the radial outer direction.

  Subsequently, the first pressing surface 6e of the first holding member 6 presses the outer side surface 1a of the first flange portion 1A, and the second pressing surface 5e of the second holding member 5 is the outer side surface 1a of the second flange portion 1B. The first fastening bolt 70A and the second fastening bolt 70B are sequentially tightened until the insertion portion 5A and the insertion portion 6A are pulled in the joining direction (see FIG. 6). By this, the reinforcement jig P rotates together clockwise, and the dropout prevention mechanism 9 and the nut 4B reliably abut.

  After mounting the reinforcing jig P, similarly, other reinforcing jigs P are sequentially mounted from the radially outer direction to the other nuts 4B in the both flange portions 1A and 1B (see FIG. 8). The reinforcing jig P may be attached to all the nuts 4B as necessary, or may be attached to only a part of the adjacent portions of the nuts 4B.

  Subsequently, the male screw parts 7a1 and 7b1 of the fastening bolts 70A and 70B are screwed into the female screw parts 5d1 and 5d2 of the insertion part 5A, and the fastening mechanism 7 of all the reinforcing jigs P is additionally tightened. At this time, since the fastening bolts 70A and 70B are located radially outward of the flanges 1A and 1B and outside the bottom 6Aa of the inserted portion 6A, the fastening operation is easy. In addition, since the detachment prevention mechanism 9 is in a state of being in contact with the nut 4B, the tightening posture is stabilized.

  When the fastening bolts 70A and 70B are tightened and fixed, both pressing surfaces 6e and 5e of both holding members 6 and 5 move close to each other in a state of being in contact with the outer surfaces 1a and 1a of both flanges 1A and 1B. At the same time, the first flange portion 1A and the second flange portion 1B move closer to each other by the tightening force of the fastening bolts 70A and 70B. As a result, the nut 4B can be further tightened. At this time, in the present embodiment, since the first fastening mechanism 7A and the second fastening mechanism 7B provided adjacent to the first fastening mechanism 7A are provided, the fastening torque for the flange joint portion of the fastening mechanism 7 is obtained. Can be further increased.

  Further, in a state in which the reinforcing jig P is fixed to both the flange portions 1A and 1B, a virtual annular surface in which the centers of the first pressing surface 6e and the second pressing surface 5e extend the outer shape of the nut 4B in the circumferential direction. It will be located in the area of For this reason, when the first pressing surface 6e and the second pressing surface 5e move close to each other, a fixed gap is easily formed between the nut 4B and the first flange portion 1A, and the nut 4B becomes the first flange portion 1A. There is no inconvenience that it will be a hit state against Therefore, when the nut 4B is tightened, the flanges 1A and 1B move close to each other uniformly.

  Next, additional tightening is performed on all the nuts 4B joining the flanges 1A and 1B using a tightening tool R such as a ratchet spanner (see FIG. 10). At this time, the connecting bolt 4A is fixed using another tool such as a spanner. In this embodiment, the step 9Bc, which is stepped toward the first flange 1A so that the edge 9Ba of the arm 9B of the fall-off preventing mechanism 9 retracts in the joining direction with respect to the nut 4B, is from the base 9A. It is formed across the tip 9Bb (see FIG. 9). That is, the height of the detachment prevention mechanism 9 is set smaller than the height of the nut 4B around the nut 4B. Therefore, when tightening the nut 4B, since the tightening tool R can be reliably inserted around the nut 4B, it is not necessary to configure the nut 4B with an expensive high nut.

  Subsequently, the tightening bolts 70A, 70B and the nut 4B are alternately tightened until the tightening torques of the connecting bolt 4A, the nut 4B and the tightening bolts 70A, 70B reach a predetermined reference value. Thereby, the bonding strength between the flanges 1A and 1B by the reinforcing jig P can be further improved, and separation and deviation of the flanges 1A and 1B and leakage of the water due to these can be more reliably prevented. Also, the seismic performance of the pipeline can be improved. In particular, the fastening mechanism 7 in the present embodiment has a first fastening mechanism 7A and a second fastening mechanism 7B provided adjacent to the first fastening mechanism 7A. For this reason, the fastening torque with respect to both the flange parts 1A and 1B of the fastening mechanism 7 can further be increased. As a result, even with the large-diameter flanges 1A and 1B, it is possible to increase the detachment prevention force.

  As shown in FIG. 6, in the present embodiment, in addition to the fastening portion of the fastening mechanism 7, an overlapping portion of the insertion portion 5A and the insertion portion 6A is provided. Therefore, when a shearing force is applied to shift both flanges 1A and 1B in the radial direction, or a tensile force is applied to separate both flanges 1A and 1B in the axial direction, and both pressing of both holding members 6 and 5 are performed. Even when the surfaces 6e and 5e receive the force in the opening direction, the stress applied to the fastening portion of the fastening mechanism 7 can be reduced.

  In the present embodiment, since the female screw parts 5d1 and 5d2 are positioned at the overlapping portion of the insertion part 5A and the insertion part 6A, the lengths of the fastening bolts 70A and 70B can be made relatively short. Therefore, it can be prevented well that the tip of fastening bolt 70A, 70B protrudes outside cylindrical interior space 5c1, 5c2. In addition, in the state where male screw parts 7a1 and 7b1 of fastening bolts 70A and 70B are inserted into insertion holes 6d1 and 6d2, a predetermined amount is provided between the outer peripheral surface of male screw parts 7a1 and 7b1 and the inner peripheral surface of insertion holes 6d1 and 6d2. A gap is formed. Therefore, even if the fastening bolts 70A and 70B are slightly displaced in the radial direction by a force in the shear direction (radial direction) acting on both flanges 1A and 1B, the male screw 7a1 of the fastening bolts 70A and 70B. , 7b1 do not abut the insertion holes 6d1 and 6d2, and it is possible to prevent the elongation and breakage of the fastening bolts 70A and 70B.

  Further, in the present embodiment, the surface of the arm 9B of the drop prevention mechanism 9 facing the outer surface 1a of the first flange 1A is separated from the outer surface 1a of the first flange 1A more than the first pressing surface 6e. Since it is disposed on the side, even when the fastening bolt 70A is tightened, the arm portion 9B does not abut on the outer side surface 1a of the first flange portion 1A. As a result, no load is directly applied to the drop prevention mechanism 9, and breakage of the drop prevention mechanism 9 can be prevented.

  Furthermore, even if distortion, deformation, or relative displacement occurs in both flanges 1A, 1B due to own weight or earthquake, etc., the fall-off preventing mechanism 9 abuts on the nut 4B securely, so both reinforcing jigs P It is possible to more reliably prevent the flanges 1A and 1B from falling off. Similarly, even when the reinforcing jig P is provided at any place in the circumferential direction of both flanges 1A, 1B, the reinforcing jig P is prevented from dropping downward from both flanges 1A, 1B. be able to.

  Hereinafter, only the configuration different from the above-described embodiment will be described with respect to another embodiment. In order to facilitate understanding of the drawings, the same members will be described using the same names and reference numerals.

[Modification Example of Mounting Reinforcement Jig]
FIG. 11 shows an example in which the reinforcing jig P is attached to both flanges 1A and 1B in the case where the pipe (not shown) as the first cylindrical member and the valve device 1X are used as the second cylindrical member. . In the valve device 1X of the present embodiment, a pedestal 1Xa is provided in a storage space such as a gate valve, and outer peripheral surfaces 1c and 1c on the bottom side of both flange portions 1A and 1B are formed in a rectangular shape protruding outward in the radial direction. It is done. Moreover, the some rib 1Xb is provided in the piping connected to both flange part 1A, 1B. The reinforcing jig P according to the present embodiment includes the dropout prevention mechanism 9 configured to be removable from the first pressing portion 6B, so that the reinforcing jig P can be mounted in a form that avoids irregularities such as the ribs 1Xb.

  Specifically, when there is no space for inserting the arm portion 9B of the dropout prevention mechanism 9 inward in the radial direction of the nut 4B due to the unevenness such as the rib 1Xb, the dropout prevention mechanism 9 is the first pressing of the first holding member 6 A reinforcing jig P not attached to the portion 6B is attached to both flanges 1A and 1B. Further, the inserted portion 6A is disposed obliquely at one corner of the pedestal 1Xa with a slight distance from the outer peripheral surfaces 1c and 1c of the flanges 1A and 1B, and the reinforcing jig P is placed at the other corner of the pedestal 1Xa. In the inverted state, the inserted portions 6A are disposed obliquely with a slight distance from the outer peripheral surfaces 1c and 1c of the flanges 1A and 1B. As described above, with respect to the reinforcing jig P in the present embodiment, the fall-off preventing mechanism 9 can be easily removed at a location where the installation of the reinforcing jig P becomes difficult due to the falling-off prevention mechanism 9 interfering with it. As a result, even if it is a flange joint of any shape, the number of reinforcing jigs P installed by mixing the reinforcing jig P having the falling-off preventing mechanism 9 and the reinforcing jig P not having the falling-off preventing mechanism 9. It is possible to secure the maximum

First Modification of First Embodiment
As a modified example of the first pressing portion 6B in the embodiment described above, as shown in FIG. 12, the distal end portion of the first pressing portion 6B contacts the base 9A in a radially inward direction than the base 9A of the detachment preventing mechanism 9 An inner diameter step portion 6j may be provided. By this, if the base 9A is inserted into the recess formed between the outer diameter step portion 6i and the inner diameter step portion 6j, the dropout prevention mechanism 9 can be attached to the first pressing portion 6B. It is easy. Further, the depression formed between the outer diameter step portion 6i and the inner diameter step portion 6j can reliably prevent the first pressing portion 6B of the falling prevention mechanism 9 from falling off.

Second Modification of First Embodiment
As shown in FIG. 13, an inclined surface 91 a is formed at the end of the outer pressing portion 6 B of the outer pressing portion 6 B of the outer surface contact portion 91 of the base 9 A of the drop prevention mechanism 9. The radially outer step portion 6i of the pressing portion 6B may be inclined to correspond to the inclined surface 91a. The inclined surface 91a is formed to be farther from the tip of the first pressing portion 6B as it is separated from the arm 9B. In other words, since the arm 9B is an L-shaped or C-shaped member that abuts against the nut 4B from the inside in the radial direction toward the outside in the radial direction, the inclined surface 91a extends in the extending direction of the arm 9B. It is inclined in the direction along. Thereby, when the fastening bolts 70A and 70B are tightened, the reaction force received from the nut 4B by the arm 9B of the detachment prevention mechanism 9 acts perpendicular to the inclined surface 91a, so that the reaction force is surely made by the inclined surface 91a. It is received by Thus, the inclined surface 91a can reliably prevent such a disadvantage that the arm portion 9B rotates in the radially inward direction by the reaction force received from the nut 4B.

Third Modification of First Embodiment
As shown in FIG. 14, the base 9A of the fall-off preventing mechanism 9 is brought into contact with the tip surface 6k of the first pressing portion 6B so as to connect between the pair of side contact portions 92 and the pair of side contact portions 92. You may comprise with the front end surface contact part 93 to contact. Further, at the end opposite to the tip end surface contact portion 93 of one side contact portion 92 from which the arm portion 9B extends, a first convex portion 92b is formed projecting to the opposite side to the arm portion 9B. In the side surface 6h of the first pressing portion 6B with which one side surface contact portion 92 abuts, a long groove-shaped first concave portion 6m is formed. Thus, the base 9A is moved closer to the end face 6k of the first pressing portion 6B, and the first inserted portion 92b of the base 9A is engaged with the first recess 6m of the first pressing portion 6B. As the first convex portion 92b abuts on the side wall of the first concave portion 6m, the distal end surface abutting portion 93 abuts on the distal end surface 6k. As described above, since the dropout prevention mechanism 9 can be mounted on the first pressing portion 6B with the first convex portion 92b and the first concave portion 6m as marks, mounting is easy. The first convex portion 92 b and the first concave portion 6 m may be provided on the other side contact portion 92 side.

Fourth Modified Example of First Embodiment
As shown in FIG. 15, the base portion 9A of the fall-off preventing mechanism 9 is a side contact portion 92 from which the arm 9B extends, and an outer surface contact portion extending from one end of the side contact portion 92. 91 and a pressing function portion 94 extending from the other end of the side surface contact portion 92 and functioning as a first pressing surface 6e for pressing the outer surface 1a of the first flange portion 1A. Further, the pressing function portion 94 is provided with a second convex portion 94a protruding toward the outer surface contact portion 91, and a long groove-like second concave portion 6n is formed in the first pressing surface 6e. Thereby, the base 9A is approached from the side surface 6h of the first pressing portion 6B, and the second pressing portion 94a of the base 9A is engaged with the second recess 6n of the first pressing portion 6B. When moved to the other side surface 6h side of the portion 6B, the second projection 94a abuts on the side wall of the second recess 6n, and the side contact portion 92 abuts on the one side surface 6h of the first pressing portion 6B. As described above, the dropout prevention mechanism 9 can be mounted on the first pressing portion 6B with the second convex portion 94a and the second concave portion 6n as marks, so that mounting is easy.

Second Embodiment
The reinforcement jig P which concerns on 2nd embodiment is shown by FIGS. 16-17. In the bottom portion 6Aa of the inserted portion 6A in this embodiment, the height of the second head 7b2 of the second fastening bolt 70B (second bolt) corresponds to the first head of the first fastening bolt 70A (first bolt). A tapered step 6Ab is formed to be lower than the height 7a2. Further, the first pressing portion 6B is formed in a tapered shape in which the side opposite to the side on which the first pressing surface 6e is formed is inclined toward the tip end side.

  Thus, among the plurality of reinforcing jigs P installed in both flange portions 1A and 1B, the first fastening bolt 70A of one reinforcing jig P and another reinforcing jig adjacent to one reinforcing jig P The second fastening bolt 70B having a second head 7b2 lower than the first head 7a2 of the first fastening bolt 70A is positioned between the P first fastening bolt 70A (see FIG. 17). As a result, when tightening the nuts 4B of both flanges 1A and 1B with the tightening tool R, the tightening tool R does not get caught on the second head 7b 2 and the rotation range of the tightening tool R can be enlarged. it can. Therefore, the tightening operation of the nut 4B for obtaining a desired tightening torque is easy.

Third Embodiment
As shown in FIG. 18, the insertion portion 51A of the second holding member 51 is formed in a square bar shape having an outer diameter that can be inserted into the inserted portion 61A of the first holding member 61, and the insertion of the first holding member 61 is performed. The portion 61A is formed in a tubular shape. Then, a pair of bolts 52 having a male screw portion 52a is formed in the joining direction so as to protrude on the tip end side of the insertion portion 51A, and in a state where the insertion portion 51A is engaged with the insertion portion 51A in a relatively non-rotatable manner The fastening nut 53 may be screwed until it abuts on the outer surface side from the outer side of the inserted portion 61A.

Other Embodiments
(A) The number of connection bolts 4A and nuts 4B can be appropriately adjusted according to the nominal diameter of flanges 1A and 1B, the design pressure, and the like. In the embodiment described above, the side where the nut 4B is positioned is the first flange portion 1A, and the side where the head 4a of the connecting bolt 4A is positioned is the second flange portion 1B, but the side where the nut 4B is positioned is the first The side where the double flange portion 1B and the head 4a of the connecting bolt 4A are located may be used as the first flange portion 1A.

(B) The mounting procedure of the reinforcement jig P can be changed suitably. For example, the first pressing surface 6e of the first holding member 6 is brought into contact with the outer side surface 1a of the first flange portion 1A, and the insertion portion 5A of the second holding member 5 is inserted into the inserted portion 6A in the joining direction. While the second pressing surface 5e is in contact with the outer side surface 1a of the second flange portion 1B. Subsequently, the dropout prevention mechanism 9 is attached to the first pressing portion 6B of the first holding member 6 so as to abut or approach the nut 4B from the radially inner side of the first flange portion 1A. Then, the male screw parts 7a1 and 7b1 of the fastening bolts 70A and 70B are screwed into the female screw parts 5d1 and 5d2 of the insertion part 5A through the insertion holes 6d1 and 6d2 of the insertion part 6A, and both clamping members 6 and 5 are flanged It can also be attached to the sections 1A and 1B.

  As another mounting procedure, first, the first pressing surface 6e of the first holding member 6 on which the drop prevention mechanism 9 is mounted is brought into contact with the outer side surface 1a of the first flange portion 1A, and the drop prevention mechanism 9 is The nut 4B is brought into contact with or in proximity to the nut 4B from the radially inner side of the portion 1A. Then, the second pressing surface 5e is brought into contact with the outer side surface 1a of the second flange portion 1B while inserting the insertion portion 5A of the second holding member 5 into the inside of the inserted portion 6A in the joining direction. Then, the male screw parts 7a1 and 7b1 of the fastening bolts 70A and 70B are screwed into the female screw parts 5d1 and 5d2 of the insertion part 5A through the insertion holes 6d1 and 6d2 of the insertion part 6A, and both clamping members 6 and 5 are flanged It can also be attached to the sections 1A and 1B.

(C) In the above embodiment, the dropout prevention mechanism 9 is provided only on the first holding member 6, but may be provided on the second holding member 5 or both holding members 6, 5 as necessary. Further, the arm 9B of the dropout prevention mechanism 9 is formed in a concave shape that wraps radially outward from the radially inner side of both flanges 1A, 1B with respect to the head 4a of the connection bolt 4A or the nut 4B. Instead, it may be configured simply by a rod-like member that abuts from the radially inner side of both flange portions 1A, 1B. Further, the step 9Bc formed on the arm 9B of the dropout prevention mechanism 9 may be omitted.

(D) In the above embodiment, the first holding member 6 is provided with the inserted portion 6A, and the second holding member 5 is provided with the insertion portion 5A. However, the second holding member 5 is provided with the inserted portion The first holding member 6 may be configured to have an insertion portion.

(E) In the above embodiment, the shape of the insertion portion 5A of the second holding member 5 and the inserted portion 6A of the first holding member 6 is an elliptical shape in a cross sectional view, but relative rotation around the bonding direction As long as it is configured to be impossible, it may have any shape. For example, when viewed in cross section, the outer surface 5a of the insertion portion 5A and the inner surface 6b of the insertion portion 6A can be formed in a polygonal shape or the like.

(F) In the above-described embodiment, the first fastening mechanism 7A and the second fastening mechanism 7B are provided. However, the fastening mechanism 7 may be configured by one.

(G) In the above embodiment, both flanges 1A and 1B have been described as so-called RF flanges, but any other flange connection may be used as long as it is a flange connection, for example, a groove for a gasket It may be a so-called GF type flange provided with

(H) In the above embodiment, the reinforcing jig P is attached to both flange portions 1A and 1B formed on the two cast water pipes 1 and 1 made of cast iron, which is an example of a fluid pipe constituting a fluid piping system (pipeline). Although the example has been described, the fluid pipe may be a pipe through which gas or liquid flows.

  The reinforcing jig and the reinforcing structure of the joint according to the present disclosure can be used as a jig for reinforcing the joint between the pipes, between the fluid devices, or the joint between the fluid machine and the pipe.

1 Water pipe (first tubular member, second tubular member)
1A First flange portion 1B Second flange portion 1a Outer side surface 4A Connecting bolt 4a Head 4B Nut 5 Second holding member 5C Second pressing portion 6 First holding member 6B First pressing portion 6e First pressing surface (pressing surface)
6g Outer surface 6h both side surface 6i diameter outer step (step)
7 Fastening mechanism 9 Falling prevention mechanism 9A Base 9B Arm 9C Extraction prevention portion 91 Outer surface contact portion 92 Side surface contact portion P Reinforcement jig

Claims (3)

A joint portion in which a first flange portion protruding radially outward from an end portion of the first cylindrical member and a second flange portion protruding radially outward from the end portion of the second cylindrical member are joined by a connection bolt It is a reinforcement jig of a joint to be mounted,
A first pressing portion for pressing an outer surface in the joining direction of the first flange portion where the head or nut of the connection bolt is disposed;
A second pressing portion that presses the outer surface of the second flange portion;
A fastening mechanism for fixing the first pressing portion and the second pressing portion in the bonding direction so as to be close to each other;
A reinforcing jig for a joint portion, comprising: a dropout prevention mechanism configured to be detachably attached to the first pressing portion and coming into contact with the head or the nut from the radial inner side toward the radial outer direction. The drop prevention mechanism is
Of the first pressing portion, an outer surface contact portion contacting an outer surface opposite to the pressing surface pressing the outer surface of the first flange portion with respect to the joining direction, and both end portions of the outer surface contacting portion A base having a pair of side contact portions that contact the opposite side surfaces of the first pressing portion, and the extending portion;
An arm portion extending from one of the pair of side surface contact portions and abutting against the head or nut in the radial direction from the inner side in the radial direction;
The reinforcement jig of the joint portion according to claim 1, further comprising: a withdrawal preventing portion provided on the other of the pair of side contact portions and preventing the detachment prevention mechanism from coming off.   The reinforcing member according to claim 2, wherein a stepped portion is formed on at least one of the outer surface and the both side surfaces of the first pressing portion so as to abut the base in the radially outer direction than the base. Equipment.

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