Temporary fastening jig

Abstract

To provide a temporary fastening jig for temporarily fastening a flange joint to be fastened, capable of supporting an inner surface packing sandwiched between the flange joint and the temporary fastening jig at an appropriate position.SOLUTION: A temporary fastening jig 10 for temporarily fastening a flange joint 5 to be fastened includes a cylindrical pin portion 11 to be inserted into an 6b of a bolt hole of the flange joint 5, and a head portion 16 having an outside diameter larger than an inside diameter of the 6a of the bolt hole, and the pin portion 11 has, on a cylindrical side surface thereof, a packing support plane 13 dug down to support a disk-shaped inner surface packing 9 installed between the flange joints 5. The packing support plane 13 is a plane parallel to a tangential plane in contact with the cylindrical side surface of the pin portion 11.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a temporary fastening jig for temporarily fastening a flange joint. [Background technology]

[0002] Flange joints have traditionally been widely used as a method of connecting pipes in piping work. When using flange joints to connect pipes, adjacent flange joints are fastened together with bolts and nuts, with a packing (gasket) sandwiched between them.

[0003] However, with conventional construction methods, a worker must align the bolt holes of adjacent flange joints and simultaneously insert the gasket in the appropriate position in order to fasten them with bolts, making this task difficult for one person to perform.

[0004] In view of these issues, Patent Document 1 below proposes facilitating the connection work of flange joints by passing a temporary fixing pin (reamer pin) through the bolt holes of adjacent flange joints during the fastening work to temporarily fasten the two together, and further supporting the inner surface packing sandwiched between them with this pin. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2020-34069 Summary of the Invention [Problem to be solved by the invention]

[0006] Looking at the sizes of commonly available flange joints, fastening bolts, and inner packing (gaskets), for example, the diameter of a fastening bolt (16 mm) is set 3 mm smaller in diameter and 1.5 mm smaller in radius than the inner diameter (19 mm) of a bolt hole in a flange joint. This is to ensure that the fastening bolt can be inserted reliably and easily into the bolt hole of a flange joint even if there are manufacturing errors, etc.

[0007] This means that even in the case of flange joints with bolt hole inner diameters other than 19mm, such as 15mm, 23mm, 25mm, and 27mm, the diameters of the fastening bolts used to fasten each bolt hole are similarly set to 12mm, 20mm, 22mm, and 24mm, all of which are 3mm smaller in diameter.

[0008] In addition, the outer diameter of commonly available inner packings is set so that when the center holes of the flange joint and the inner packing are aligned, the outer edge of the inner packing protrudes 1.5 mm radially from the bolt hole, so that it can be well supported by a fastening bolt whose diameter is 3 mm smaller than the diameter of the bolt hole.

[0009] In contrast to this, in the above Patent Document 1, the diameter of the temporary fixing pin is approximately the same as the inner diameter of the bolt hole (0 to 0.5 mm smaller), so when the packing is supported by the temporary fixing pin, which is the same size as the bolt hole, its outer edge does not protrude into the bolt hole area, and the packing is shifted upward from the appropriate installation position when fastened.

[0010] If a full-surface gasket is installed in a misaligned position, the outer edge of the gasket will be exposed to the outside of the flange joint, making it possible to return it to the appropriate position. However, if an internal gasket is used, it is sandwiched between the flange joints and cannot be seen from the outside, making it difficult to check the installation position. Furthermore, if it is installed in a misaligned position, the center hole of the internal gasket will become misaligned, hindering the smooth flow of fluid within the piping after installation.

[0011] The present invention has been made in consideration of these problems, and aims to provide a temporary fastening jig for temporarily fastening flange joints to be fastened, which is capable of supporting the inner surface packing sandwiched between the two in an appropriate position. [Means for solving the problem]

[0012] In order to solve the above problems, the temporary fastening jig of the present invention is a temporary fastening jig for temporarily fastening flange joints to be fastened, and is characterized in that it comprises a cylindrical pin portion that is inserted into a bolt hole of the flange joint, and a head portion having an outer diameter larger than the inner diameter of the bolt hole, and the pin portion has a gasket support plane formed on its cylindrical side surface that is dug out to support a disk-shaped inner gasket that is installed between the flange joints.

[0013] Furthermore, the flange joint fastening method of the present invention is a flange joint fastening method for fastening two flange joints using the above-mentioned temporary fastening jig, and comprises: a temporary fastening step of inserting the pin portions of the temporary fastening jig into the two bolt holes on the lower side of the flange joints to be fastened to temporarily fasten the two flange joints; a packing support step of sandwiching an inner surface packing between the flange joints and supporting it by the packing support plane; and a fastening step of fastening the bolt holes of the flange joints with bolts and nuts, wherein the temporary fastening step is a step of inserting the pin portions in an orientation in which the packing support plane is perpendicular to the radial direction of the flange joint and faces radially inward. [Effects of the Invention]

[0014] The temporary fastening jig according to the present invention makes it possible to temporarily fasten the inner surface packing that is sandwiched between the flange joints to be fastened while supporting it in an appropriate position. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view of a temporary fastening jig according to an embodiment of the present invention. [Figure 2]FIG. 2 is a diagram showing the configuration of a temporary fastening jig according to an embodiment of the present invention. [Figure 3] FIG. 3 is a diagram showing the configuration of a flange joint according to an embodiment of the present invention. [Figure 4] FIG. 4 is a perspective view showing the configuration of a packing according to an embodiment of the present invention. [Figure 5] FIG. 5 is a diagram illustrating a temporarily fastened state according to an embodiment of the present invention. [Figure 6] FIG. 6 is a perspective view illustrating a temporarily fastened state according to an embodiment of the present invention. [Figure 7] FIG. 7 is a front view showing the fastened state of a flange joint according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] The temporary fastening jig used when fastening flange joints according to this embodiment will be described in detail below with reference to the drawings. In this embodiment, a temporary fastening jig 10 will be described that is used when fastening and connecting two adjacent flange joints 5 with bolts 3 passed through bolt holes 6b in flange portions 6 during piping work.

[0017] First, we will explain the configuration of the flange joints 5 to be fastened and the inner surface packing 9 that is sandwiched between the two flange joints 5 when fastened. Figure 3(a) is a perspective view of the flange joint 5, Figure 3(b) is a front view of the flange joint 5, and Figure 3(c) is a side view of the flange joint 5.

[0018] The flange joint 5 is made of stainless steel and includes a disk-shaped flange portion 6 with a central hole 6a formed therein and a tubular portion 7 that protrudes to one side from the central hole 6a of the flange portion 6. The central hole 6a is a hole through which fluid flows through the tubular portion 7. Four bolt holes 6b are formed in the flange portion 6 at a predetermined radial distance from the central hole 6a, spaced at 90° intervals in the circumferential direction. The inner diameter of the bolt holes 6b is 19 mm.

[0019] As shown in Figure 4, the inner packing 9 is in the shape of a thin disk, and has a center hole 9a formed therein that is the same shape as the center hole 6a of the flange joint 5. The outer diameter of the inner packing 9 is configured so that when the center hole 9a is aligned with the center hole 6a of the flange portion 6, the outer edge of the inner packing 9 protrudes 1.5 mm in the radial direction into the area of ​​the bolt holes 6b. The diameter of the center hole 9a of the inner packing 9 is the same as the diameter of the center hole 6a of the flange portion 6 and the inner diameter of the pipe portion 7.

[0020] The temporary fastening jig 10 has a pin portion 11 that is inserted into the bolt hole 6b of the flange joint 5, and a head portion 16 that is located at the base end of the pin portion 11. Fig. 2(a) is a plan view of the temporary fastening jig 10, Fig. 2(b) is a front view of the temporary fastening jig 10, and Fig. 2(c) is a side view of the temporary fastening jig 10.

[0021] The pin portion 11 has a long, thin cylindrical shape, and its tip portion is tapered to form a tapered portion 12. A flat, plane packing support plane 13 is formed on the cylindrical side surface of the pin portion 11 (the upper part of the cylindrical side surface in Figure 1). The packing support plane 13 is a plane obtained by hollowing out the tangent plane that contacts the side surface of the cylindrical pin portion 11 in parallel with the radial direction to a depth of 1.5 mm.

[0022] Head 16 is disk-shaped with an outer diameter (diameter) larger than the inner diameter of bolt hole 6b, and cannot enter bolt hole 6b. The diameter of pin portion 11 is set to be slightly smaller than the inner diameter of bolt hole 6b. In this embodiment, the inner diameter of bolt hole 6b is 19 mm, while the diameter of pin portion 11 is 18.6 mm, which is 0.4 mm smaller.

[0023] If the diameter of pin portion 11 becomes too large and approaches the inner diameter of bolt hole 6b, it becomes difficult to insert pin portion 11 into bolt hole 6b. The actual inner diameter of bolt hole 6b and the outer diameter of pin portion 11 may deviate from the design values ​​due to manufacturing errors. Therefore, it is desirable that the diameter of pin portion 11 be at least 0.2 mm smaller than the design value of the inner diameter of bolt hole 6b.

[0024] On the other hand, if the diameter of the pin portion 11 becomes smaller and the difference between the diameter and the inner diameter of the bolt hole 6b becomes larger, when the pin portion 11 is inserted into the bolt hole 6b, the gap between the pin portion 11 and the inner wall surface of the bolt hole 6b becomes larger, causing the pin portion 11 to rattle relative to the bolt hole 6b.

[0025] In other words, the flange joint 5 cannot be stably temporarily fastened during fastening. Therefore, it is desirable that the diameter of the pin portion 11 is not smaller than the inner diameter of the bolt hole 6b by more than 0.4 mm. In this way, the diameter of the pin portion 11 is slightly smaller than the inner diameter of the bolt hole 6b, and is desirably within the range of 0.2 mm to 0.4 mm.

[0026] The packing support plane 13 is formed at its tip from a position a predetermined distance (14 mm in this embodiment) away from the end of the pin portion 11 on the head 16 side. In this embodiment, the thickness of the disk-shaped flange portion 6 is 14 mm, and the packing support plane 13 is spaced from the head 16 by an amount corresponding to this thickness.

[0027] Of course, the position of the packing support plane 13 on the head 16 side can be changed as appropriate, and it may be formed from the boundary with the head 16 toward the tip, that is, over the entire axial direction of the pin portion 11.

[0028] However, if the packing support plane 13 is farther away from the end on the head 16 side than the thickness of the flange portion 6, the packing support plane 13 will not be in a position to support the inner packing 9 when temporarily fastened, so the distance from the end on the head 16 side must be smaller than the thickness of the flange portion 6.

[0029] Furthermore, the packing support plane 13 needs to be formed up to the tip of the pin portion 11. If the tip side of the packing support plane 13 is not formed up to the tip of the pin portion 11, even if an attempt is made to remove the pin portion 11 after fastening the bolt hole 6b into which the temporary fastening jig 10 is not inserted with the bolt 3 and nut 4 during temporary fastening, the inner packing 6 will get caught on a step on the tip side of the packing support plane 13 and will not come out.

[0030] Furthermore, if the length of the excavation from the tangent plane of the packing support plane 13 that contacts the cylindrical side surface of the pin portion 11 becomes larger than the radius of the pin portion 11, the pin portion 11 will become more wobbly within the bolt hole 6b and will no longer be able to be temporarily fastened stably, so the excavation length must be smaller than the radius of the pin portion 11.

[0031] However, as mentioned above, the inner packing 6 currently on the market is designed so that when its central hole 9a is aligned with the central hole 6a of the flange joint 6, its outer edge protrudes 1.5 mm into the area of ​​the bolt hole 6b, so the length to be dug into the packing support plane 13 is usually 1.5 mm, which does not pose a problem.

[0032] The configuration of the temporary fastening jig 10 has been described above, and next, a method for fastening a flange joint using the temporary fastening jig 10 will be described with reference to Figures 5 to 7. Figure 5 is a perspective view showing adjacent flange joints 5 temporarily fastened by two temporary fastening jigs 10.

[0033] Figure 6(a) is a side view showing the state in which two temporary fastening jigs 10 are inserted into the two lower bolt holes 6b of one of the flange joints 5, and Figure 6(b) is a side view for explaining the state in which the inner gasket 6 is supported by the gasket support surface 13 of the temporary fastening jig 10, with the other flange joint 5 omitted.

[0034] First, as shown in Figure 6(a), the pin portions 11 of the temporary fastening jig 10 are inserted into and penetrate the two bolt holes 6b located below one of the flange joints 5 to be fastened. When inserting the pin portions 11, they are inserted with the packing support flat surfaces 13 of the pin portions 11 facing radially inward of the flange portion 6.

[0035] In detail, the packing support plane 13 is perpendicular to the radial direction of the flange portion 6, and is tilted inward by 45° from the horizontal state (in FIG. 6, the left-side pin portion 11 is to the right, and the right-side pin portion 11 is to the left). At this time, if the pin portion 11 of the temporary fastening jig 10 is inserted all the way in so that the head portion 16 contacts the surface of the flange portion 6, the entire packing support plane 13 will pass through the bolt hole 6b and be exposed on the opposite side.

[0036] Next, the other flange joint 5 is also temporarily fastened together using the temporary fastening jig 10. Specifically, with the inner surface packing 6 sandwiched between them, the tip of the pin portion 11 that penetrates and protrudes through one flange portion 6 is inserted into the bolt hole 6b of the other flange joint 6.

[0037] As a result, adjacent flange joints 5 are temporarily fastened together by two temporary fastening jigs 10 with the inner packing 6 sandwiched between them (see Figure 5). At this time, the inner packing 9 is supported at two points by the packing support flat surfaces 13 of the two temporary fastening jigs 10 located below the flange joint 5 (see Figure 6(b)).

[0038] The supported position of the inner packing 6 is a position where its central hole 9a overlaps with the central hole 6a of the flange portion 6, and where its peripheral edge protrudes 1.5 mm into the area of ​​each bolt hole 6b in the radial direction of the flange portion 6 so as to slightly overlap with all four bolt holes 6b.

[0039] In this way, in this embodiment, by inserting the temporary fastening jig 10 into the bolt hole 6b of the flange joint 5 and temporarily fastening it, the inner surface gasket 6 can be accurately positioned in a good position when fastened, and the effort required for fastening the flange joint 5 can be significantly reduced.

[0040] Furthermore, if the position of the inner packing 9 is slightly misaligned, it is possible to appropriately adjust the position and height at which the packing support plane 13 of the temporary fastening jig 10 and the packing 9 come into contact by rotating the temporary fastening jig 10 inserted into the bolt hole 6b around its axis.

[0041] Finally, in this temporarily fastened state, the upper two bolt holes 6b are lightly fastened with bolts 3 and nuts 4, and then the temporary fastening jigs 10 are removed one by one, and the bolt holes 6b in the removed locations are sequentially fastened with bolts 3 and nuts 4, so that all four bolt holes 6b can be fastened with bolts 3 and nuts 4 (see Figure 7).

[0042] Furthermore, if the two upper bolt holes 6b are fastened, the inner packing 6 is sandwiched between the two flange joints 5, so even if the temporary fastening jig 10 is removed, the inner packing 6 will not fall out.

[0043] This embodiment has been described in detail above. According to this embodiment, the temporary fastening jig 10 used for temporary fastening of the flange joint 5 is provided with a packing support plane 13, and by making the diameter of the pin portion 11 slightly smaller than the inner diameter of the bolt hole 6b, stable temporary fastening without rattle by the pin portion 11 inserted into the bolt hole 6b is achieved, and during temporary fastening, the inner surface packing 6 can be supported in an appropriate position where it protrudes 1.5 mm into the area of ​​the bolt hole 6b, thereby significantly improving the workability of the fastening work.

[0044] Furthermore, by fastening the flange joint 5 with the inner packing 6 supported in an appropriate position, the position of the center hole 9a of the inner packing 6 and the position of the center hole 6a of the flange joint 5 will accurately match, allowing fluid to flow smoothly through the piping after installation.

[0045] Furthermore, by rotating the temporary fastening jig 10 around its axis, the packing support plane 13 rotates around the axis of the pin portion 11, so that the support position of the inner packing 6 can be finely adjusted.

[0046] The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the present invention. For example, the shape, size, and material of the components constituting the temporary fastening jig can be changed as appropriate.

[0047] The material of the temporary fastening jig may be iron or aluminum other than stainless steel. The present invention can be applied to commercially available flange joints and inner surface packings of various sizes. [Explanation of symbols]

[0048] 10 Temporary fastening jig 11 Pin section 12 Tapered section 13 Packing support plane 16 head 3 Volts 4 nuts 5 Flange joint 6 Flange 6a center hole 6b Bolt hole 7 Pipe section 9 Inner packing 9a center hole

Claims

1. In a temporary fastening jig for temporarily fastening a flange joint to be fastened, A cylindrical pin portion to be inserted into a bolt hole of the flange joint; a head portion having an outer diameter larger than the inner diameter of the bolt hole, A temporary fastening jig characterized in that the pin portion has a gasket support plane formed on its cylindrical side surface that is dug out to support a disc-shaped inner gasket to be installed between the flange joints.

2. 2. The temporary fastening jig according to claim 1, wherein the packing support plane is a plane parallel to a tangent plane that contacts the cylindrical side surface of the pin portion.

3. 3. The temporary fastening jig according to claim 2, wherein the packing support plane is a plane recessed 1.5 mm from the tangential plane.

4. 2. The temporary fastening jig according to claim 1, wherein the packing support plane is formed from a predetermined position on the head side of the pin portion to the tip.

5. 2. The temporary fastening jig according to claim 1, wherein the diameter of the pin portion is slightly smaller than the inner diameter of the bolt hole.

6. 2. A method for fastening two flange joints using the temporary fastening jig according to claim 1, a temporary fastening process in which the pin portions of the temporary fastening jig are inserted into the two lower bolt holes of the flange joints to be fastened, thereby temporarily fastening the two flange joints; a packing support step of sandwiching an inner packing between the flange joints and supporting it by the packing support plane; a fastening step of fastening the bolt holes of the flange joint with bolts and nuts, A method for fastening a flange joint, characterized in that the temporary fastening step is a step of inserting the pin portion in an attitude in which the packing support plane is perpendicular to the radial direction of the flange joint and faces radially inward.

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