JP2022008994A - Attachment method of flange separation prevention device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an attachment method of a flange separation prevention device which can fasten a bolt in a small working space, can avoid damage, and can efficiently grip a flange.

SOLUTION: In an attachment method of a flange separation prevention device 4 which comprises a grip frame 5 having a grip piece part 5b arranged outside a pipe axial direction of either of a pair of flanges 1a, 1a' for connecting a pair of conduit constitution members, a grip body 6 arranged outside the pipe axial direction of the other flange, and a bolt 7 for imparting a pressing force to the grip body, presses the grip body by the bolt, and grips a pair of the flanges by the grip part and the grip piece part, an existing connection bolt and a nut for connecting a pair of the flanges are exchanged to a new connection bolt 2a and a nut 2b, the grip body is pressed to the grip frame by the bolt so as to make the bolt obliquely advance and retreat with respect to the pipe axial directions of the conduit constitution members in a state that a pair of the flanges is gripped by the grip body and the grip piece part, and after a pair of the flanges is gripped by the grip body and the grip piece part, the new connection bolt and the nut are tightened.

SELECTED DRAWING: Figure 8

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to a flange separation prevention device that prevents a pair of facing flanges from being separated from each other.

Conventionally, a flange separation prevention device used for increasing the connection strength between flange-connected pipeline constituent members is a narrow-holding frame having a narrow-holding piece portion arranged on the outer side in the pipe axis direction of a pair of flanges. There is a bolt that is attached to the narrow holding piece portion of the above and presses the flange in the pipe axis direction of the fluid pipe, and the bolt and the other narrow holding piece portion hold a pair of flanges (for example). , Patent Document 1).

In addition, two flanges are arranged so as to sandwich the pair of flanges in the pipe axis direction, and the pair of flanges are connected by bolts at positions outside the pair of flanges in the pipe axis direction. There was something that was narrowed down (see, for example, Patent Document 2).

However, since the flange separation prevention devices shown in Patent Documents 1 and 2 have a configuration in which a pair of flanges are narrowed by tightening bolts in the pipe axis direction of the pipeline constituent member, the fluid pipe has a structure. When a component such as a repair valve is arranged in the pipe axis direction, it may not be possible to perform the work of tightening the bolt by interfering with the component. Further, in Patent Document 2, since the two sandwiching members are tightened with bolts at the positions outside the pair of flanges, the inner portions of the sandwiching members may open and the sandwiching members may not be sufficiently sandwiched.

Therefore, a bolt capable of advancing and retreating in the radial direction of the pair of flanges with the narrow holding frame attached to the pair of flanges and an intervening member pressed by the bolt are provided, and the bolt is provided in the outer diameter direction of the pair of flanges. The pressing force generated in the radial direction by advancing in the inner diameter direction is converted into the pressing force in the pipe axis direction by the inclined surface of the intervening member, and the intervening member and the narrowing piece portion of the holding frame form a pair. A flange has been developed that narrows the flange in the pipe axis direction (see, for example, Patent Document 3).

Jikkai Sho 63-103086 (1st page, 1st figure) Japanese Unexamined Patent Publication No. 2016-125599 (Page 10, Fig. 9) Japanese Unexamined Patent Publication No. 2015-178850 (Page 5, Fig. 3)

In the flange separation prevention device of Patent Document 3, since the bolts are oriented in the radial direction, the bolts can be tightened while avoiding the constituent members arranged in the pipe axis direction of the pair of flanges. , Bolt tightening work can be done easily, but since the bolt is configured to protrude greatly in the outer diameter direction of the fluid pipe, not only a large work space is required in the outer diameter direction of the fluid pipe, but also the work There was a risk that the flange separation prevention device would be damaged due to the load applied to the backfilling afterwards and the interference of heavy machinery during re-excavation.

The present invention has been made by paying attention to such a problem, and is a flange separation prevention device capable of tightening bolts in a small work space, avoiding breakage, and efficiently sandwiching a flange. The purpose is to provide.

In order to solve the above problems, the flange separation prevention device of the present invention is used.
A narrow holding frame having a narrow holding piece portion arranged outside the pipe axis direction of one flange in a pair of flanges connecting a pair of pipeline components, and a narrow holding frame arranged outside the pipe axis direction of the other flange. A body and a bolt that applies a pressing force to the narrow holding body are provided, and by pressing the narrow holding body with the bolt, the pair of flanges are narrowed between the narrow holding body and the narrow holding piece portion. It is a flange separation prevention device to be held.
The bolt is attached to the holding frame so as to advance and retreat diagonally with respect to the pipe axis direction of the pipeline constituent member in a state where the pair of flanges is held between the holding body and the holding piece portion. It is characterized by being attached.
According to this feature, since the bolt advances and retreats diagonally with respect to the pipe axis direction of the pipeline constituent member, it is possible to prevent the bolt from protruding significantly in the radial direction of the pipeline constituent member, so that the bolt can be used in a small space. The tightening work can be performed, and the flange can be efficiently pinched by suppressing damage during backfilling or re-excavation.

The bolt is characterized in that it extends substantially parallel to the moving direction of the holding body.
According to this feature, the pressing force of the bolt can be efficiently transmitted to the holding body without being dispersed.

The narrowed body has a pressed surface that is pressed by the bolt, and the bolt is characterized in that it presses substantially perpendicular to the pressed surface.
According to this feature, the pressing force of the bolt can be efficiently transmitted to the holding body without being dispersed.

The narrow holding frame has an accommodating portion capable of accommodating the narrow holding body, and has an accommodating portion.
A movement restricting portion that comes into contact with the narrow holding body is provided on the inner diameter side of the pipeline constituent member of the accommodating portion.
According to this feature, the narrow holding body can be strongly pressed against the flange by the bolt and the movement restricting portion.

The movement restricting portion and the narrow holding body each have an inclined surface extending substantially parallel to the bolt, and the inclined surfaces are in surface contact with each other.
According to this feature, the inclined surfaces of the movement restricting portion and the narrow holding body are brought into surface contact with each other, so that the pair of flanges can be narrowly held while maintaining an appropriate angle between the narrow holding frame and the narrow holding body. ..

The narrow holding body is characterized by having a locking piece that can be locked on the inner diameter side of the pipeline constituent member of the connecting bolt connecting the pair of flanges.
According to this feature, it is possible to prevent the narrow holding body from slipping in the outer diameter direction of the pipeline constituent member.

The bolt is characterized in that it is inclined in a range of 45 degrees or less with respect to the pipe axis of the pipeline constituent member.
According to this feature, the pressing force of the bolt can be efficiently transmitted to the holding body without being dispersed.

The narrow holding body is characterized in that at least a part thereof includes a connecting bolt connecting the pair of flanges and an overlapping portion superposed in the pipe axis direction.
According to this feature, since the narrow holding body can be arranged as close as possible to the connecting bolt by the overlapping portion, the narrow holding body can be arranged even when the separation width between the adjacent connecting bolts is small.

The holding member for holding the narrow holding body in the narrow holding frame is provided in the narrow holding body.
According to this feature, the narrow holding body and the narrow holding frame can be unitized by the holding member, so that it is easy to handle.

It is a top view which shows the flange connection part which attached the flange separation prevention device in Example 1. FIG. FIG. 1 is a cross-sectional view taken along the line AA of FIG. FIG. 2 is a cross-sectional view taken along the line BB of FIG. (A) is a side view showing the structure of the flange separation prevention device in the first embodiment, (b) is also a front view, and (c) is also a top view. (A) is a side view showing the structure of the narrow holding frame, (b) is the same front view, (c) is the same top view, (d) is the same bottom view, (e) is a CC sectional view, (f). ) Is a cross-sectional view taken along the line DD. (A) is a side view showing the structure of the narrow holding body in Example 1, (b) is also a bottom view, (c) is a side view showing the structure of a narrow holding body having a different standard, and (d) is also a bottom view. Is. (A) is a side sectional view showing a state before tightening the bolt in the flange separation prevention device, and (b) is a side sectional view showing a state after tightening the bolt in the flange separation prevention device. (A) is a side sectional view showing a state in which the flange separation prevention device is temporarily installed at the flange connection portion, and (b) is an EE sectional view. (A) is a side sectional view showing a state in which the flange separation prevention device is slid to the outer diameter side from the state of FIG. 8, and (b) is an FF sectional view. (A) is a side sectional view showing a state in which a bolt is tightened from the state of FIG. 8 and a flange separation prevention device is fixed to a flange connection portion, and (b) is a GG sectional view. (A) is a side sectional view showing the flange separation preventing device of the modified example 1, and (b) is a side sectional view showing the flange separation preventing device of the modified example 2. (A) is a side sectional view showing the flange separation prevention device of the modified example 3, (b) is a side view of the narrow holding body in the modified example 3, and (c) is a bottom view of the narrowed body in the modified example 3. (A) is a side sectional view showing the flange separation prevention device of the modification 4, and (b) is a top view showing a state in which the flange separation prevention device of the modification 4 is attached to the flange connection portion.

A mode for carrying out the flange separation prevention device according to the present invention will be described below based on examples.

The flange separation prevention device according to the first embodiment will be described with reference to FIGS. 1 to 10. As shown in FIGS. 1 and 2, the fluid pipeline buried in the ground is configured by connecting a plurality of fluid pipes 1, 1', ... (Pipeline constituent members). The fluid in the fluid pipes 1 and 1'may be, for example, clean water, industrial water, sewage, or the like, or a gas or a gas-liquid mixture of a gas and a liquid.

The fluid pipes 1 and 1'are ductile cast iron pipes and are formed in a substantially circular shape in cross section. The fluid pipe according to the present invention may be made of other metal such as cast iron or steel, or may be made of concrete, vinyl chloride, polyethylene, polyolefin or the like. Furthermore, the inner peripheral surface of the fluid tube may be coated with an epoxy resin layer, mortar, plating, or the like, or an appropriate material may be coated on the inner peripheral surface of the fluid tube by powder coating.

Here, a connection mode of the fluid pipes 1, 1'will be described by way of example. The fluid pipes 1 and 1'have flanges 1a and 1a'(flange connection portions) protruding from the ends in a direction (diametrical direction) orthogonal to the pipe axis, respectively, and the flanges 1a and 1a' are overlapped with each other. At the same time, the fluid tubes 1 and 1'are connected to each other by tightening the flanges 1a and 1a'by the connecting bolts 2a and the nuts 2b extending in the pipe axis direction. Further, one fluid pipe 1 is a short pipe, and a structural member 3 such as a repair valve is connected to an end opposite to the other fluid pipe 1', and the outer surface of the structural member 3 is a fluid pipe. It is designed to overhang greatly in the radial direction of 1. The structural member 3 is not limited to the repair valve, and may be another valve, a joint, or the like.

In such a connection mode of the fluid pipes 1 and 1', since they are connected only by a plurality of connection bolts 2a and nuts 2b arranged in the circumferential direction, the connection strength is insufficient and the fluid pipe 1 is connected. , 1'Because there is a risk that the flanges 1a and 1a'will be separated due to the pressure of the fluid flowing in 1', the external force such as an earthquake, and the influence of rust due to aging. The connection strength of the flanges 1a and 1a'is increased by attaching the 4'to the flanges 1a and 1a' afterwards.

In this embodiment, the flange separation prevention devices 4, 4'are arranged in a predetermined number in the circumferential direction of the flanges 1a, 1a' (for convenience of explanation, pipes are arranged at two locations facing each other in the radial direction in the figure. The flange separation prevention device 4'is attached to the flanges 1a, 1a'in a state of being inverted upside down with respect to the flange separation prevention device 4). The quantity and mounting orientation of the flange separation prevention devices 4 and 4'mounted on the flanges 1a and 1a'may be freely changed, but the holding force is substantially evenly distributed in the circumferential direction of the flanges 1a and 1a'. It is preferable that a plurality of them are attached in a substantially equal arrangement in order to impart the above.

Next, the structure of the flange separation prevention device 4 will be described with reference to FIGS. 2 to 6. As shown in FIGS. 2 and 4, the flange separation prevention device 4 is mainly composed of a narrow holding frame 5, a narrow holding body 6, and a bolt 7. Since the flange separation prevention devices 4 and 4'have substantially the same configuration, only the flange separation prevention device 4 will be described, and the description of the flange separation prevention device 4'will be omitted.

First, the narrow holding frame 5 will be described. As shown in FIG. 2, the narrow holding frame 5 is composed of a base portion 5a facing the outer peripheral surface of the pair of flanges 1a, 1a'and a narrow holding piece portion 5b, 5c erected at both ends of the base portion 5a. It is a member having a substantially U-shaped side view, and can be fitted from the outer diameter side of the flanges 1a and 1a'.

When the narrow holding frame 5 is fitted to the flanges 1a and 1a', one of the narrow holding piece portions 5b (the lower narrow holding piece portion in this embodiment) is the lower flange 1a'. The other narrow-holding piece portion 5c (upper narrow-holding piece portion in this embodiment) is arranged below the upper flange 1a, and the base portion 5a is located on the outer diameter side of the flanges 1a, 1a'. Be placed. Hereinafter, for convenience of explanation, the base portion 5a side of the narrow holding frame 5 is the outer diameter side of the flanges 1a, 1a', and the narrow holding piece portions 5b, 5c even if they are not attached to the flanges 1a, 1a'. The free end side of the above will be described as the inner diameter side of the flanges 1a and 1a'.

As shown in FIG. 5, a specific configuration of the narrow holding frame 5 will be described. The lower portion of the base portion 5a is a vertical portion 5d that stands substantially vertically in the side view of the narrow holding frame 5, and is a base portion. The upper portion of 5a is an inclined portion 5e extending upward so as to be inclined toward the outer diameter side with respect to the vertical portion 5d (see particularly FIG. 5 (f)). At the lower end of the vertical portion 5d, one narrow holding piece portion 5b extending substantially horizontally toward the inner diameter side along the lower surface of the lower flange 1a'is provided (see FIG. 2). A notch 5f that opens to the tip side is formed at a substantially central portion of the tip portion of the narrow holding piece portion 5b in the extending direction. According to this, since the nut 2b can be accommodated in the notch portion 5f, the narrow holding piece portion 5b can be arranged at the place where the connection bolt 2a and the nut 2b are arranged (see FIGS. 1 and 3). ..

Further, the tip portion 5g of the narrow holding piece portion 5b slightly protrudes upward, and a plurality of grooves are formed in a mesh shape on the protruding upper surface (particularly, see FIG. 5E). According to this, since the unevenness is formed in the tip portion 5g by a plurality of grooves, the frictional force when contacting the lower surface of the flange 1a'is increased, and the grip force is enhanced.

The other narrow holding piece portion 5c has an upper wall portion 5h extending upward from the upper end of the inclined portion 5e of the base portion 5a on the inner diameter side, and an upper wall portion 5h inclined downward on the inner diameter side from the tip of the upper wall portion 5h. A pair provided so as to close both sides of a U-shaped cross-sectional portion composed of a front wall portion 5j extending substantially parallel to the portion 5e, an inclined portion 5e, an upper wall portion 5h, and a front wall portion 5j. It is composed of the side wall portions 5k and 5k of the above (see particularly FIG. 5 (f)). That is, the accommodation recess 51 (accommodation portion) that opens diagonally downward on the inner diameter side is formed by the inclined portion 5e, the upper wall portion 5h, the front wall portion 5j, and the side wall portions 5k and 5k, and the accommodation recess 51 is formed. , The above-mentioned narrow holding body 6 can be accommodated.

The inner diameter side of the accommodating recess 51 is tapered portions 5q and 5q configured to taper in the inner diameter direction (see particularly FIGS. 5 (c) and 10 (b)). Since the tapered portions 5q and 5q are formed at the edge portions of the front wall portion 5j and the side wall portions 5k and 5k, they are inclined at the same angle as the front wall portion 5j when viewed from the side.

The upper wall portion 5h is formed with a screw hole 5m penetrating substantially at right angles to the extending direction of the upper wall portion 5h, and the bolt 7 can be screwed into the screw hole 5m. Further, a recess 5n capable of partially accommodating the head of the bolt 7 is formed around the screw hole 5m on the upper surface side of the upper wall portion 5h.

The front wall portion 5j is inclined downward on the inner diameter side substantially parallel to the central axis of the screw hole 5m and extends. Further, a notch 5p that opens downward is formed in a substantially central portion of the tip edge of the front wall portion 5j. The width of the notch 5p is dimension L3 (see FIG. 5B).

Next, the holding body 6 will be described with reference to FIG. As shown in FIGS. 6A and 6B, the holding body 6 has a pressing surface 6a that presses the upper surface of the flange 1a, a pressed surface 6b that is pressed by the bolt 7, and tapered portions 5q and 5q. It is mainly composed of tapered portions 6c and 6c that can be contacted, and locking pieces 6d and 6d that can be locked to the head of the connection bolt 2a as described later.

The lower portion of the narrow holding body 6 provided with the pressing surface 6a is formed with a step portion so that the inner diameter side thereof is located above the pressing surface 6a, and the step portion is formed so as to project downward from the inner diameter side end portion of the step portion. Locking pieces 6d and 6d are arranged laterally apart from each other. A notch accommodating portion 6e capable of accommodating the head of the connection bolt 2a is formed in the portion of the narrow holding body 6 where the above-mentioned step portion is provided, and the inner diameter side and the lower side of the notch accommodating portion 6e are opened. ing.

The opening on the inner diameter side of the notch accommodating portion 6e is formed at a position separated from the locking pieces 6d and 6d on the outer diameter side, and the opening width is wider than the width of the head of the connection bolt 2a of a normal standard. Has a slightly larger size L1. Further, since the vertical width of the notch accommodating portion 6e is formed to be larger than the vertical thickness of the head of the connection bolt 2a, the connection bolt 2a is in a state where the head of the connection bolt 2a is accommodated in the notch accommodating portion 6e. The head of the head and the holding body 6 do not come into contact with each other up and down.

Further, the narrow holding body 6 is tapered on the inner diameter side when viewed from the upper surface side due to the tapered portions 6c and 6c. That is, the lateral width of the inner diameter side end portion 6h of the narrow holding body 6 is tapered so as to be smaller than the lateral width dimension L5 on the outer diameter side of the narrow holding body 6 (L4 <L5). Further, the width dimension L4 of the inner diameter side end portion 6h in the narrow holding body 6 is smaller than the width dimension L3 of the notch portion 5p described above (L3> L4).

The inner diameter side end portion 6h of the narrow holding body 6 is inclined so that the upper end portion is located on the outer diameter side of the lower end portion. Further, since the tapered portions 6c and 6c are formed at the edge portion between the side surface of the narrow holding body 6 and the inner diameter side end portion 6h, the upper end portion is located on the outer diameter side of the lower end portion when viewed from the side surface side. It is tilted to do.

Further, concave slits 6f, 6f that incline from the upper outer diameter side to the lower inner diameter side are formed on both side surfaces of the narrow holding body 6, and the slits 6f, 6f hold elastic. Members 6g and 6g can be mounted. As shown in FIG. 6B, the holding members 6g and 6g have side walls constituting the narrow holding body 6 and the accommodating recess 51 when the narrow holding body 6 is accommodated in the accommodating recess 51 of the narrow holding frame 5. It is designed to be compressed between the parts 5k and 5k. According to this, when the narrow holding body 6 is housed in the storage recess 51 of the narrow holding frame 5, the elastic restoring force of the holding members 6g and 6g compressed between the narrow holding body 6 and the side wall portions 5k and 5k. Therefore, it is possible to prevent the narrow holding body 6 from falling from the accommodating recess 51. That is, since the narrow holding frame 5 and the narrow holding body 6 can be unitized by the holding members 6g and 6g, the flange separation prevention device 4 can be easily attached to the flanges 1a and 1a'.

Further, as shown in FIGS. 6 (c) and 6 (d), a narrow holding body 6'is prepared in which the opening width of the opening portion on the inner diameter side of the notch accommodating portion 6e'is a dimension L2 larger than the dimension L1. Therefore, it is possible to handle connection bolts having different specifications (connection bolts having a head larger than the head of the connection bolt 2a). It should be noted that a narrow holding body having an opening width of the notch accommodating portion smaller than the dimension L1 may be prepared so as to be compatible with a connecting bolt having a head smaller than the head of the connecting bolt 2a. Furthermore, three or more types of narrow holding bodies 6 having different opening widths of the notch accommodating portion 6e may be prepared so as to be compatible with various connection bolts having different specifications.

Next, the operation of the flange separation prevention device 4 will be described with reference to FIG. 7. As shown in FIG. 7A, in the state before the bolt 7 is tightened, the narrow holding body 6 is accommodated in the accommodating recess 51 of the narrowing frame 5 so as to be substantially accommodated, and the accommodating recess is provided. By contacting the upper wall portion 5h and the front wall portion 5j constituting the 51, it becomes difficult to tilt. Since a slight gap is formed in the radial direction between the accommodating recess 51 and the narrow holding body 6, it is possible to move in the radial direction within the range of the gap.

Further, the bolt 7 is substantially perpendicular to the pressed surface 6b of the narrow holding body 6 in a state where the narrow holding body 6 is housed in the housing recess 51, and is near the center of gravity of the narrow holding body 6. The axis of the bolt 7 passes through. Further, the pressing surface 7a (tip surface) of the bolt 7 and the pressed surface 6b are in surface contact with each other, but the pressing surface (tip surface) of the bolt 7 is not limited to this. By forming it into a substantially spherical surface, it may be in point contact with the pressed surface 6b of the substantially flat surface of the narrow holding body 6.

As shown in FIG. 7 (b), when the bolt 7 is tightened from the state of FIG. 7 (a), the narrow holding body 6 is pressed by the bolt 7 and the inner diameter is guided by the inner peripheral wall forming the accommodating recess 51. Slide diagonally downward toward the side. Specifically, in addition to the presence of the center of gravity of the narrow holding body 6 in the axial direction of the bolt 7, the bolt 7 is substantially perpendicular to the pressed surface 6b of the narrow holding body 6, so that the narrow holding body 6 is provided. Will slide and move substantially parallel to the pressing direction of the bolt 7 while maintaining that posture. That is, the pressing force of the bolt 7 can be efficiently transmitted to the holding body 6 without being dispersed in a direction different from the pressing direction.

Further, since the pressing surface 7a of the bolt 7 and the pressed surface 6b are in surface contact with each other, when the holding body 6 is pressed by the bolt 7, the bolt 7 and the holding body 6 are relative to each other. Tilt is unlikely to occur, and the pressing force of the bolt 7 can be distributed evenly and efficiently to the narrow holding body 6. Further, even if the narrow holding body 6 is tilted, it is guided by the accommodating recess 51 and the posture of the narrow holding body 6 is maintained.

When the narrow holding body 6 is pressed by a predetermined distance, the inner diameter side end portion 6h of the narrow holding body 6 is arranged while being guided to a position corresponding to the notch portion 5p in the narrow holding frame 5. As described above, since the width dimension L4 of the inner diameter side end portion 6h of the narrow holding body 6 is smaller than the width dimension L3 of the notch portion 5p in the narrow holding frame 5, the inner diameter side end portion 6h of the narrow holding body 6 Can move (tilt) within the notch 5p. According to this, the inclination of the narrow holding body 6 can be adjusted until the flanges 1a and 1a'are pressed by the narrow holding body 6.

Next, a state in which the flange separation prevention device 4 is actually temporarily installed on the flanges 1a and 1a'will be described with reference to FIGS. 8 and 9. Here, a case where the flange separation prevention device 4 is temporarily installed in the existing fluid pipes 1 and 1'will be described as an example.

In FIG. 8, in a state where the narrow holding body 6 is housed in the storage recess 51 of the narrow holding frame 5, the flanges 1a and 1a'are fitted from the outer diameter side, and the pressing surface 6a of the narrow holding body 6 and the narrow holding frame 5 are fitted. It shows a temporary installation state in which the bolt 7 is tightened until the narrow holding piece portion 5b of the above abuts on the upper surface and the lower surface of the flanges 1a and 1a'. In the state of FIG. 8, the pressing surface 6a of the narrow holding body 6 and the narrow holding piece portion 5b of the narrow holding frame 5 are in contact with the upper surface of the flange 1a and the lower surface of the flange 1a'. It is not tightly held in the axial direction.

When the flange separation prevention device 4 is temporarily installed on the flanges 1a, 1a', although not shown, the existing connection bolts and nuts connecting the flanges 1a, 1a' are attached to the connection bolts 2a and nuts 2b of this embodiment. Replace it. The connection bolts 2a and nuts 2b of this embodiment are made of a metal such as stainless steel, which has a rust preventive function and has high rigidity. As will be described later, in this embodiment of the connection bolt 2a, the degree of rotation of the hexagonal head is adjusted so that the head of the connection bolt 2a is accommodated in the notch accommodating portion 6e of the holding body 6. deep.

In the state where the flange separation prevention device 4 is temporarily installed on the flanges 1a and 1a', as described above, the nut 2b is housed in the notch portion 5f of the narrow holding frame 5, and the notch of the narrow holding body 6 is accommodated. The head of the connecting bolt 2a is housed in the accommodating portion 6e, and the locking pieces 6d and 6d are arranged so as to be separated from the head of the connecting bolt 2a on the inner diameter side.

In other words, since a part of the narrow holding frame 5 and the narrow holding body 6 overlaps the connecting bolt 2a and the nut 2b in the pipe axis direction, they are brought as close as possible to the connecting bolt 2a and the nut 2b to prevent flange separation. When the device 4 (narrowing frame 5 and narrowing body 6) can be arranged and the separation width of the connection bolt 2a and the nut 2b adjacent in the circumferential direction is small (for example, the flanges 1a and 1a as in this embodiment). Even when the connection bolts 2a and nuts 2b are arranged in 8 equal parts with respect to'), the flange separation prevention device 4 can be arranged without interfering with the adjacent connection bolts 2a and nuts 2b. That is, the notch portion 5f and the notch accommodating portion 6e function as a superimposing portion that overlaps with the connection bolt 2a and the nut 2b in the pipe axis direction.

Further, since the inner surface of the notch accommodating portion 6e of the narrow holding body 6 and the outer surface of the head of the connecting bolt 2a are in contact with each other, the flange separation preventing device 4 is restricted from rotating.

In a state where the flange separation prevention device 4 is temporarily installed on the flanges 1a, 1a', the pressing surface 6a of the narrow holding body 6 and the narrow holding piece portion 5b of the narrow holding frame 5 connect the flanges 1a, 1a' to the pipe shaft. Since it is not tightly held in the direction, it may move relative to the outer diameter side with respect to the flanges 1a and 1a'due to the external force. Further, the center of gravity of the flange separation prevention device 4 is located on the outer diameter side of the flanges 1a and 1a', and the reaction force generated when the bolt 7 presses the narrow holding body 6 acts on the outer diameter side. Therefore, in the middle stage until the flange separation prevention device 4 is temporarily installed on the flanges 1a, 1a', the flange separation prevention device 4 tends to move to the outer diameter side with respect to the flanges 1a, 1a'.

FIG. 9 shows a state in which the flange separation prevention device 4 is moved from the state of FIG. 8 to the outer diameter side by an external force. When the flange separation prevention device 4 moves to the outer diameter side, the locking pieces 6d and 6d are locked to the head of the connection bolt 2a, and the narrow holding frame 5 is mounted on the tapered portion 6c of the narrow holding body 6. By locking the tapered portion 5q (not shown), it is possible to prevent the flange separation preventing device 4 from moving to the outer diameter side of the flanges 1a and 1a'and falling off.

Further, the inner surface of the notch accommodating portion 6e of the narrow holding body 6 and the outer surface of the head of the connecting bolt 2a are in contact with each other, and the locking pieces 6d and 6d are engaged on both sides of the rotation center of the connecting bolt 2a. Since it is stopped, it is possible to suitably prevent the flange separation preventing device 4 from rotating due to the screwing of the bolt 7. Further, it is possible to prevent the connection bolt 2a from rotating due to the contact between the head of the connection bolt 2a and the locking pieces 6d and 6d.

Next, a state in which the flange separation prevention device 4 is actually installed on the flanges 1a and 1a'will be described with reference to FIG. In FIG. 10, the bolt 7 is tightened from the state of FIG. 8, and the flanges 1a and 1a'are strongly narrowed in the pipe axis direction by the pressing surface 6a of the narrow holding body 6 and the narrow holding piece portion 5b of the narrow holding frame 5. It shows the installation status.

As shown in FIG. 10A, when the bolt 7 is tightened from the state of FIG. 8, the holding body 6 is pressed diagonally downward on the inner diameter side of the flanges 1a, 1a', and the holding body 6 is pressed. The reaction force generated when the flange 1a is pressed is transmitted to the narrow holding frame 5 via the bolt 7, and the narrow holding frame 5 moves diagonally upward on the outer diameter side of the flanges 1a, 1a'. As a result, the flanges 1a and 1a'are strongly narrowed in the pipe axis direction by the pressing surface 6a of the narrow holding body 6 and the narrow holding piece portion 5b of the narrow holding frame 5.

Further, since the tip portion 5g of the narrow holding piece portion 5b is in direct contact with the lower surface of the flange 1a'and a plurality of irregularities are formed on the tip portion 5g, the flange 1a'. A large frictional force acts when it comes into contact with the lower surface of the flange, and it is possible to prevent the narrow holding piece portion 5b and the lower surface of the flange 1a'from sliding.

As shown in FIG. 10B, when the bolt 7 is tightened from the state of FIG. 8, the holding body 6 moves diagonally downward on the inner diameter side of the flanges 1a, 1a', and the holding frame 5 moves to the flange 1a, Since it moves diagonally upward on the outer diameter side of 1a', the tapered portions 6c and 6c of the narrow holding body 6 come into contact with the tapered portions 5q and 5q (movement restricting portion) of the narrow holding frame 5, and the inner diameter of the narrow holding body 6 is reached. Movement diagonally downward is restricted. In this embodiment, since the tapered portions 5q and 5q of the narrow holding frame 5 and the tapered portions 6c and 6c of the narrow holding body 6 come into contact with each other, the front wall portion 5j of the narrow holding frame 5 and the narrow holding body 6 come into contact with each other. It does not come into contact with the inner diameter side end portion 6h of 6.

Further, since the tapered portions 5q and 5q and the tapered portions 6c and 6c are inclined from the upper outer diameter side to the lower inner diameter side, the movement of the narrow holding body 6 diagonally downward on the inner diameter side is on the lower side in the pipe axis direction. It is converted to the movement to (flange 1a side). In this way, the narrow holding body 6 can be strongly pressed against the flange 1a by the bolt 7 and the tapered portions 5q and 5q.

Further, as described above, when the head of the connecting bolt 2a is housed in the notch accommodating portion 6e, the head of the connecting bolt 2a and the holding body 6 do not come into contact with each other in the vertical direction. The pressing surface 6a of the body 6 can press the flange 1a in a stable state. As described above, as a result of the flanges 1a and 1a'being strongly pinched by tightening the bolt 7, the packing (not shown) interposed between the flanges 1a and 1a' is crushed, and the separation distance between the flanges 1a and 1a' is increased. If it is narrowed, it is advisable to retighten the connection bolt 2a and the nut 2b. At the time of retightening, the head of the connecting bolt 2a is accommodated in the notch accommodating portion 6e of the holding body 6 and its rotation is restricted, so that the head of the connecting bolt 2a is accommodated in the notch portion 5f of the holding frame 5 in a loosely fitted state. The nut 2b can be rotated by a tool or the like (not shown).

As described above, the bolt 7 has a pair of flanges 1a, 1a'held by the narrow-holding body 6 and the narrow-holding piece portion 5b in the pipe-axis direction, and the fluid pipe 1,1'in the pipe-axis direction. It is attached to the narrow holding frame 5 so as to be inclined toward the outer diameter side, and is adapted to advance and retreat diagonally with respect to the pipe axis direction of the fluid pipes 1, 1'.

According to this, even when a structural member 3 such as a repair valve that greatly projects in the radial direction of the fluid pipe 1 in the pipe axial direction of the fluid pipes 1 and 1'is attached as in the present embodiment. By advancing and retreating the bolt 7 diagonally with respect to the pipe axis direction of the fluid pipes 1 and 1', the bolt 7 can be tightened while avoiding interference with the structural member 3.

Further, since it is possible to prevent the bolt 7 from protruding significantly in the radial direction of the fluid pipes 1, 1', the work space required for the tightening work of the bolt 7 can be reduced. In addition, it is possible to increase the durability against the load (earth pressure, etc.) applied during backfilling after the work, and heavy machinery and the like can be used during re-excavation when performing predetermined work around the flanges 1a, 1a'. Since it is difficult to interfere with each other, the flanges 1a and 1a'can be efficiently sandwiched by avoiding damage to the flange separation prevention device 4.

Further, in this embodiment, in a state where the pair of flanges 1a and 1a'are sandwiched between the narrow holding body 6 and the narrow holding piece portion 5b in the pipe axis direction, the bolt 7 is the pipe shaft of the fluid pipes 1, 1'. It is inclined to the outer diameter side by about 30 degrees with respect to the direction. According to this, since the pressing direction of the bolt 7 can be brought closer to the pipe axial direction of the fluid tubes 1, 1'(the holding direction of the flanges 1a, 1a'), the pressing force of the bolt 7 is applied to the flanges 1a, 1a'. It can be efficiently transmitted to the holding body 6 in the holding direction of the flanges 1a, 1a'without being dispersed in a direction different from the holding direction of.

In this embodiment, the embodiment in which the bolt 7 is inclined to the outer diameter side of the fluid pipes 1, 1'by about 30 degrees with respect to the pipe axis direction is exemplified, but the present invention is not limited to this, and the fluid pipes 1, 1' The angle of the bolt 7 with respect to the pipe axis direction can be freely changed, but from the viewpoint of efficiently transmitting the pressing force of the bolt 7 in the holding direction of the flanges 1a, 1a', the bolt 7 is a pipe of the fluid pipes 1, 1'. It is preferable that the tube is tilted in a range of 45 degrees or less with respect to the axial direction. Further, in this embodiment, the embodiment in which the axis of the bolt 7 intersects with the tube axis of the fluid pipes 1, 1'is illustrated, but the axis of the bolt 7 does not intersect with the tube axis of the fluid pipes 1, 1'. May be.

Further, it can be attached to the flanges 1a, 1a'in a state of being turned upside down like the flange separation prevention devices 4, 4'. Specifically, in the case of the flange separation prevention device 4, the bolt 7 is inclined to the outer diameter side of about 30 degrees with respect to the pipe axis direction of the fluid pipes 1, 1', and in the case of the flange separation prevention device 4', the bolt 7 is inclined to the outer diameter side. The bolt 7 is tilted to the outer diameter side of the fluid pipes 1, 1'by approximately 150 degrees with respect to the pipe axis direction. Therefore, the inclination angle of the bolt 7 with respect to the pipe axis direction of the fluid pipes 1 and 1'is changed depending on the direction in which the flange separation prevention device is attached. It can be attached to the flanges 1a and 1a'.

Further, when the bolt 7 is tightened to narrow the flanges 1a and 1a', a force that rotates the flange separation prevention device 4 around the axis of the bolt 7 is generated. Since the notch accommodating portion 6e of the body 6 and the head of the connecting bolt 2a are in contact with each other, the rotation of the flange separation preventing device 4 is restricted.

Further, as shown in FIG. 3, in a state where the flange separation prevention device 4 is attached to the flanges 1a, 1a', the side edge portions 5r, 5r on the inner diameter side of the base portion 5a of the narrow holding frame 5 are the flanges 1a, 1a'. Since it is arranged near the outer diameter side of the above, even if the flange separation prevention device 4 is slightly rotated by the tightening operation of the bolt 7, the side edge portions 5r and 5r abut on the flanges 1a and 1a', so that the flange separation is performed. The rotation of the prevention device 4 is surely restricted.

The narrow holding frame 5, the narrow holding body 6, and the bolt 7 constituting the flange separation prevention device 4 may be covered with a protective layer such as resin, insulating coating, plating, and rubber lining. According to this, it is possible to suppress the occurrence of rust or the like on the narrow holding frame 5, the narrow holding body 6, and the bolt 7.

Next, Modifications 1 to 4 will be described with reference to FIGS. 11 to 13. As shown in FIG. 11A, the flange separation prevention device 41 of the modified example 1 does not have a notch 5p formed in the front wall portion 51j of the narrow holding frame 511. According to this, even if the holding body 6 is pressed by the bolt 7 for a predetermined distance, it is restricted from interfering with the front wall portion 51j and tilting. Therefore, in the modified example 1, the narrow holding body 6 moves toward the flanges 1a and 1a'while maintaining the posture (the tilting is restricted), so that the narrow holding body 6 is used as a reference. As a result, it is easy to align the flange separation prevention device 41 with respect to the flanges 1a and 1a'.

Further, in the flange separation prevention device 41, the front wall portion 51j functions as a movement restricting portion of the narrow holding body 6 without providing the tapered portions 5q and 5q of the above embodiment. According to this, since the front wall portion 51j inclined substantially parallel to the bolt 7 and the inner diameter side end portion 6h of the narrow holding body 6 come into surface contact with each other, the narrow holding frame 511 and the narrow holding body 6 are suitable. Guided to maintain a relative relative angle, the pair of flanges 1a, 1a'can be suitably narrowed.

As shown in FIG. 11B, the flange separation prevention device 42 of the modified example 2 is not provided with the tapered portions 5q and 5q of the embodiment, and the tip edge 52a on the outer diameter side of the front wall portion 52j is not provided. Functions as a movement restricting portion and comes into contact with the inner diameter side end portion 6h of the narrow holding body 6. As described above, the movement restricting portion is not limited to the one that comes into surface contact with the narrow holding body 6, and may be the one that makes line contact with the narrow holding body 6. Further, although not particularly shown, the movement restricting unit may be in point contact with the narrow holding body 6. That is, the movement restricting unit may be capable of restricting the movement of the narrow holding body 6 in the inner diameter direction while the flanges 1a and 1a'are sandwiched.

The inner diameter side end portion 6h of the narrow holding body 6 is not limited to one that is inclined substantially in parallel with the bolt 7, and may be formed so as to be in contact with the movement restricting portion, for example, so as to intersect the bolt 7. You may.

Further, as shown in FIG. 12, the flange separation prevention device 43 of the modified example 3 covers the entire circumference so that the notch accommodating portion 63e of the narrow holding body 63 forms a substantially elliptical shape that is long in the radial direction when viewed from the lower surface. It is configured to be surrounded by a wall portion 63a (locking piece). According to this, even if the flange separation preventing device 43 moves in the radial direction, the wall portion 63a comes into contact with the connection bolt 2a accommodated in the notch accommodating portion 63e, so that the flange separation preventing device 43 moves in the radial direction. Can be regulated.

Although the locking piece is illustrated as being provided on the narrow holding body, the locking piece is not limited to this, and for example, a locking piece that can be locked to the connection bolt 2a is provided on the front wall portion 5j of the narrow holding frame 5. , The radial movement of the flange separation prevention device may be restricted.

As shown in FIG. 13, the flange separation prevention device 44 of the modified example 4 is not provided with a notch accommodating portion capable of accommodating the head of the connection bolt 2a in the narrow holding body 64. According to this, since the entire lower surface of the narrow holding body 64 can be the pressing surface 64a, when the flange separation prevention device 43 is attached to the flanges 1a and 1a', the flange 1a is pressed using the wide pressing surface 64a. Therefore, the flanges 1a and 1a'can be pressed stably.

For example, as shown in FIG. 13B, the connecting bolts 2a and nuts 2b are arranged in four equal parts in the circumferential direction of the flanges 1a and 1a', and the area between the adjacent connecting bolts 2a and nuts 2b is relatively large. It is useful in cases such as.

Although examples of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these examples, and any changes or additions that do not deviate from the gist of the present invention are included in the present invention. Will be.

In the above-described Examples and Modifications 1 to 4, the fluid pipes 1 and 1'have been described as pipeline constituent members, but the present invention is not limited to this, and repair valves, fire hydrant and other valves, housings and the like that constitute the pipeline are also pipes. Included in road components.

1,1'Fluid pipe (pipeline component)
1a, 1a'Flange 2a Connection bolt 2b Nut 3 Structural member 4, 4'Flange separation prevention device 5 Narrowing frame 5b, 5c Narrowing piece part 5f Notch part (superimposing part)
5q taper part (movement regulation part)
5r side edge (movement control part)
6,6'Narrow holding body 6b Pressed surface 6d Locking piece 6e, 6e' Notch accommodating part (superimposing part)
6g Holding member 6h Inner diameter side end (inclined surface)
7 Bolts 41, 42, 43, 44 Flange separation prevention device 51 Accommodation recess (accommodation part)
51j Front wall part (movement control part, inclined surface)
52a Tip edge (movement control part)
63 Narrow body 63a Wall (locking piece)
63e Notch accommodating part (accommodation part)
64 Narrow holding body 511 Narrow holding frame

Claims (9)

A narrow holding frame having a narrow holding piece portion arranged outside the pipe axis direction of one flange in a pair of flanges connecting a pair of pipeline components, and a narrow holding frame arranged outside the pipe axis direction of the other flange. A body and a bolt that applies a pressing force to the narrow holding body are provided, and by pressing the narrow holding body with the bolt, the pair of flanges are narrowed between the narrow holding body and the narrow holding piece portion. It is a method of mounting the flange separation prevention device to be held.
Replace the existing connection bolts and nuts connecting the pair of flanges with new connection bolts and nuts.
In a state where the pair of flanges are sandwiched between the narrow holding body and the narrow holding piece portion, the bolt is attached to the narrow holding frame so as to advance and retreat diagonally with respect to the pipe axis direction of the pipeline constituent member. ,
By pressing the narrow-holding body with the bolt, the pair of flanges are narrowed between the narrow-holding body and the narrow-holding piece portion, and then the new connecting bolts and nuts are retightened. How to install the flange separation prevention device. The method for mounting a flange separation preventing device according to claim 1, wherein the bolt extends substantially parallel to the moving direction of the holding body. The flange separation prevention according to claim 1 or 2, wherein the holding body has a pressed surface pressed by the bolt, and the bolt presses substantially perpendicular to the pressed surface. How to install the device. The narrow holding frame has an accommodating portion capable of accommodating the narrow holding body, and has an accommodating portion.
The flange separation prevention device according to any one of claims 1 to 3, wherein a movement restricting portion that abuts on the narrow holding body is provided on the inner diameter side of the pipeline constituent member of the accommodating portion. How to wear. The flange separation prevention device according to claim 4, wherein the movement restricting portion and the narrow holding body each have an inclined surface extending substantially parallel to the bolt, and the inclined surfaces come into surface contact with each other. How to wear. The method for mounting a flange separation preventing device according to any one of claims 1 to 5, wherein the holding body is locked to the new connecting bolt and nut by a locking piece contained in the holding body. The method for mounting a flange separation preventing device according to any one of claims 1 to 6, wherein the bolt is inclined in a range of 45 degrees or less with respect to the pipe axis of the pipeline constituent member. The method for mounting a flange separation preventing device according to any one of claims 1 to 7, wherein the sandwiching body is superimposed on the new connecting bolt and nut in the pipe axis direction by the overlapping portion of the sandwiching body. .. The method for mounting a flange separation preventing device according to any one of claims 1 to 8, wherein a holding member for holding the narrow holding body in the narrow holding frame is provided in the narrow holding body.

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