JP2013002520A - Pipe end anticorrosion structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely fix an anticorrosion core fitted to a pipe end portion of a cut pipe.SOLUTION: An anticorrosion core 11 is fitted to a pipe end portion 10a, a fitting 20 of which the cross section is U-shaped is fitted to the anticorrosion core 11, and the anticorrosion core 11 is held from the inside and the outside in a radial direction of the pipe end portion 10a between a pair of holding parts 22, 23 extending in a pipe axial direction of the fitting 20. The holding parts 22, 23 of the fitting 20 include recesses 22b, 23b which are formed by caulking a tool and extends in the pipe axial direction, and the anticorrosion core 11 is pressed to the pipe end portion 10a by the recesses 22b, 23b.

Description

  The present invention relates to a pipe end anticorrosion structure and a pipe end anticorrosion method in which a pipe end anticorrosion core or the like attached to a metal pipe insertion opening constituting various pipes such as waterworks is fixed.

  Conventionally, when a ductile cast iron pipe is buried in the ground and a pipe line is laid, the entire pipe is subjected to corrosion prevention by painting or lining, and as shown in FIG. It is common to insert and insert two insertion openings 2a. At this time, as shown in the figure, in the NS type joint provided with earthquake resistance, the lock ring 3 is provided on the inner surface of the receiving port 1a, and the lock ring 3 is inserted over the protrusion 4 as shown by a chain line in the figure. Insert the mouth 2a. In the figure, 5 is a packing and 6 is a lining.

  In the laying of this pipe line, there is a case in which it is not always limited only by joining with a fixed-size pipe, and the succeeding pipe 2 may be cut and joined so as to have a predetermined length at the construction site. When the succeeding tube 2 is cut in this way, the coating is peeled off and the background is exposed on the tube end surface that becomes the cut surface, so that the anticorrosion function is impaired and red water or the like is generated.

  Therefore, in general, anticorrosion coating is applied again to the end face after the cut tube to perform anticorrosion. However, when anticorrosion paint is applied to the end face after the cut tube and the anticorrosion is applied again, it takes time to dry in cold weather, and it is difficult to apply in places where running water does not stop completely, such as switching work. There is a problem that it is difficult to work.

  For this reason, as a method other than applying the anticorrosion paint to the end face after the cut tube, as shown in FIGS. 13 and 14, the anticorrosion core 7 is used to remove the pipe end 10a of the cast iron pipe 10 after the cut tube. There is a method of sealing the exposed part. Since the anticorrosion core 7 is made of an elastic body such as rubber, the anticorrosion core 7 is retained by its elasticity. However, as a method for more reliably fixing, the anticorrosion core is used by using a fixing ring 40 that is open in the circumferential direction. There is one in which 7 is fixed from the inner surface by the expanding force. (See Patent Document 1)

  The fixing ring 40 has one end 41 and the other end 42 overlapped, the one end 41 is overlapped with a long hole 43 formed in the other end 42, and a locking piece formed in the other end 42 in the hole 44 formed in the one end 41. 45, the locking piece 45 is folded back and the diameter reduction function of the fixing ring 40 is given by the folding.

  When the anticorrosion core 7 is fixed by the fixing ring 40, it is necessary to hold the annular fixing ring 40 on the inner surface of the tube end portion 10a in an expanded state by the snap ring pliers, and to turn the locking piece 45 back. It takes time and effort. Further, it is difficult to hold the fixing ring 40 in an expanded state, and the fixing ring 40 may be tilted or buckled, and it is necessary to become familiar with handling of the snap ring pliers.

  For this reason, as shown in FIG. 15, a pipe end anticorrosion structure is proposed in which an anticorrosion core fitted to the pipe end is sandwiched between U-shaped fixing pieces 50 and pressed against the pipe end 10a ( Patent Document 2 (see FIG. 17). When this fixing piece 50 is used, the anticorrosion core 7 can be easily fixed to the pipe end portion 10a as compared with the case where the above-described fixing ring 40 is used.

JP 2002-286195 A JP 2003-120891 A

  The U-shaped fixing piece 50 described in Patent Document 2 is obtained by processing a band-shaped metal plate into a U-shape, and sandwiching portions 50a and 50b extending in the tube axis direction are flat. . For this reason, as shown in FIG. 16, the annular anticorrosion core 7 is formed on the inner peripheral side of the tube end portion 10a by the side edges P and P of the clamping portion 50a (both side edges in the circumferential direction of the tube end). On the outer peripheral side of the portion 10a, it is pressed against the tube end portion 10a by the center of the clamping portion 50b (the center in the circumferential direction of the tube end).

The positions of pressing by the sandwiching portion 50a and the sandwiching portion 50b with respect to the anticorrosion core 7 are shifted in the circumferential direction on the inner and outer peripheral surfaces of the tube end portion 10a and do not coincide with each other. For this reason, the pinching by the fixing piece 50 becomes insufficient, and it is difficult to reliably fix the anticorrosion core 7.

  Then, the subject of this invention is to make it possible to reliably fix the anticorrosion core fitted to the tube end of the cut tube.

  In order to solve the above-mentioned problems, a pipe end anticorrosion structure according to the present invention has an anticorrosion core fitted to a pipe end, and a U-shaped fixing tool is fitted to the anticorrosion core. A tube end anticorrosion structure in which the anticorrosion core is sandwiched from the radially inner and outer sides of the tube end portion by a pair of axially extending sandwiching portions, and the holding portion of the fixture is formed by caulking of a tool. In addition, the anticorrosion core is pressed against the pipe end by the concave part of the fixture.

  If it does in this way, since the crevice of both clamping parts of a fixture pinches a corrosion prevention core from the both sides of the diameter direction inside and outside of a pipe end part, a corrosion prevention core is certainly fixed to a pipe end.

  The holding part of the fixing tool has a plurality of teeth protruding toward the tube end on the inner surface thereof, and the plurality of teeth are pressed by the recesses of the fixing tool to bite into the anticorrosion core. Can be.

  When the fixing tool having teeth is fitted together, the plurality of teeth of the both sandwiching parts bite into the anticorrosion core, and the positional deviation of the fixing tool can be prevented.

  In order to solve the above-mentioned problem, the pipe end anticorrosion method according to the present invention includes fitting an anticorrosion core to the pipe end, fitting a U-shaped fixture to the anticorrosion core, and fixing the fixing part. The anticorrosion core is sandwiched from the radially inner and outer sides of the pipe end by a pair of sandwiching portions extending in the tube axis direction, and the pair of sandwiching portions of the fixture is crimped by a tool, and the sandwiching portion is axially It is possible to adopt a method in which a concave portion extending along the line is formed and the concave portion of the fixture is pressed against the anticorrosion core.

  As described above, according to the present invention, the anticorrosion core is securely fixed because the anticorrosion core in which the concave portion of the holding part of the fixture is fitted to the pipe end is sandwiched from the radially inner side of the pipe end.

The perspective view which shows the pipe end anti-corrosion structure of one Embodiment of this invention The perspective view which shows the principal part of a pipe end anti-corrosion structure same as the above (A) Front view showing the same anticorrosion core, (b) Cross section showing the same anticorrosion core (A) The perspective view which shows a fixing tool same as the above, (b) The front view which shows a fixing tool same as the above, (c) The side view which shows a fixing tool same as the above Radial sectional view showing the main part of the pipe end anticorrosion structure Sectional drawing in the VI-VI line of FIG. (A) The front view which shows the tool used for the pipe end anticorrosion method concerning this invention, (b) The side view which shows the tool used for the pipe end anticorrosion method same as the above (A) Explanatory drawing which shows attachment of the anticorrosion core of a pipe end anticorrosion method same as the above, (b) Explanatory drawing which shows attachment of a fixing tool same as the above, (c) Explanatory drawing which shows the state before caulking by a tool same as the above, (D) Explanatory drawing which shows the state after caulking with a tool same as the above (A) Radial direction sectional view showing the state before caulking with the above tool, (b) Radial direction cross section showing the caulking state with the above tool The perspective view which shows the fixing tool of the pipe end anticorrosion structure of other embodiment, (b) The front view which shows a fixing tool same as the above, (c) The side view which shows a fixing tool same as the above Radial sectional view showing the main part of the pipe end anticorrosion structure Cross section of the main part of the pipe joint Expanded cross-sectional view of the main part of the pipe insertion opening Illustration of mounting action of fixing ring The perspective view which shows the conventional pipe end anti-corrosion structure Same as above

Hereinafter, an embodiment of a pipe end anticorrosion structure according to the present invention will be described with reference to FIGS.
This embodiment is applied to what the anticorrosion core 11 was fitted by the pipe end part 10a which cut | disconnected cast iron pipes 10, such as a ductile cast iron pipe shown in FIG. The anticorrosion core 11 is formed in a U-shaped cross section made of an elastic body such as ethylene propylene rubber (EPR) or styrene butadiene rubber (SBR) (see FIGS. 3A and 3B).

  As the anticorrosion core 11, the diameter of the outer cylinder portion 11a is slightly smaller than the outer diameter of the tube end portion 10a, while the diameter of the inner cylinder portion 11b is slightly larger than the inner diameter of the tube end portion 10a. ing. For this reason, the anticorrosion core 11 fitted to the tube end 10a covers the end surface and the inner and outer peripheral surfaces of the tube end 10a, and is in close contact with these surfaces, so that moisture, dust and the like enter the tube end 10a. To prevent.

  A plurality of fixtures 20 are attached to the anticorrosion core 11 fitted to the tube end portion 10a in the circumferential direction. As shown in FIG. 4, the fixture 20 is a rectangular band-shaped metal plate processed into a U-shaped cross section, and includes a base portion 21 and a pair of sandwiching portions 22, 23 extending in the same direction at right angles from both ends thereof. It consists of. On the opposing inner surfaces of the pair of sandwiching portions 22 and 23, teeth 22a and 23a protruding in a chevron shape are formed in a row at the tip.

  As shown in FIGS. 1 and 2, the fixture 20 attached to the tube end portion 10 a has a pair of sandwiching portions 22 and 23 formed with recesses 22 b and 23 b. The recesses 22b and 23b extend along the tube axis direction from the base 21 side end to the tip at the center of the sandwiching portions 22 and 23, and are recessed on the tube end 10a side.

  The teeth 22a and 23a of the fixture 20 bite into the distal end portions of the outer cylinder portion 11a and the inner cylinder portion 11b of the anticorrosion core 11 in the tube axis direction (see FIG. 6). The recesses 22b and 23b have a width w and a flat bottom, and the bottom presses the outer cylinder part 11a and the inner cylinder part 11b of the anticorrosion core 11 within the range of the width w (FIG. 5). reference). By pressing the recesses 22b and 23b, the teeth 22a and 23a located in the recesses 22b and 23b bite deeper into the outer cylinder part 11a and the inner cylinder part 11b of the anticorrosion core 11.

  The recesses 22b and 23b of the fixture 20 are formed by caulking the pliers 30 as the tool shown in FIG. 7 with the fixture 20 attached to the anticorrosion core 11 fitted to the tube end portion 10a.

  The pliers 30 have basically the same configuration as that of a commercially available plier, and a pair of pliers main bodies 31 having a grip 32 at one end and a clamping portion 33 at the other end are overlapped and connected via a shaft 34. It is. The pair of grips 32 and the sandwiching portion 33 facing each other can be opened and closed around a shaft 34.

  On the opposing surfaces of the pair of sandwiching portions 33, 33, a protrusion 33 a is formed in the center from the tip toward the shaft 34. The protrusion 33a has the same width as the width w of the recesses 22b and 23b of the fixture 20.

  The sandwiching portions 22 and 23 of the fixture 20 attached to the pipe end 10 a are sandwiched between the pair of sandwiching portions 33 and 33 of the pliers 30, and the gripping portions 22 and 23 are gripped so that the sandwiching portions 22 and 23 are The concave portions 22b and 23b are formed by crimping.

In the recesses 22b and 23b formed by caulking the pliers 30, the anticorrosion core 11 is pressed against the pipe end 10a by the bottom. Further, as shown in FIG. 5, the teeth 22 a and 23 a of the holding portions 22 and 23 of the fixture 20 bite into the anticorrosion core 11. Thereby, the anticorrosion core 11 is reliably fixed to the pipe end part 10 a by the fixture 20, and the pipe end part 10 a is anticorrosive by the anticorrosion core 11.

  As a method of preventing corrosion of the pipe end 10a using the fixture 20, first, the corrosion prevention core 11 is attached to the pipe end 10a of the cut cast iron pipe 10 shown in FIG. (Figure 8 (b)).

  Subsequently, the base portion 21 of the fixture 20 is connected to the anticorrosion core 11 fitted to the tube end portion 10a so that the tube end portion 10a is sandwiched between the pair of holding portions 22 and 23 from the radially inner and outer sides. The fixture 20 is fitted to the anticorrosion core 11 by pressing against the end face. At this time, as shown in FIG. 8C, the plurality of teeth 22a, 23a of the pair of sandwiching portions 22, 23 are respectively along the edges of the outer cylindrical portion 11a and the inner cylindrical portion 11b of the anticorrosive core 11. positioned. In addition, the fixture 20 is fitted to the tube end portion 10a at a plurality of locations in the circumferential direction at equal intervals.

  Subsequently, as shown in FIG. 9A, the protrusions 33 a of the pair of sandwiching portions 33, 33 of the pliers 30 are connected to the sandwiching portions 22, 23 of the fixture 20 from the base 21 side end portion to the distal end portion. To the center in the width direction.

Thereafter, the pair of grips 32 and 32 of the pliers 30 are gripped, and the clamping portions 22 and 23 of the fixture 20 are crimped (see FIG. 9B). This caulking is performed on a plurality of fixtures 20 attached in the circumferential direction of the tube end portion 10a, and recesses 22b and 23b are formed in the clamping portions 22 and 23 of the fixture 20 (see FIG. 8D).

  The bottom portions of the crimped recesses 22b and 23b sandwich the anticorrosion core 11 from the inside and outside in the radial direction of the pipe end portion 10a. Thereby, as shown in FIG.9 (b), since the clamping part 23 of the fixing tool 20 presses the anticorrosion core 11 at the bottom part of the recessed part 23b of not only the both ends edge Q of the width direction but the center part of the width direction, The anticorrosion core 11 is securely fixed to the tube end portion 10a.

Another embodiment of the pipe end anticorrosion structure according to the present invention will be described with reference to FIGS.
In the following, only the differences from the pipe end anticorrosion structure according to the above-described embodiment will be described, and the same reference numerals are used for the same conceivable components, and the description thereof will be omitted.
As shown in FIG. 10, the fixture 20 in this embodiment does not have the chevron teeth 22a, 23a in the pair of sandwiching portions 22, 23.

  The fixture 20 is fitted to the anticorrosion core 11 fitted to the tube end portion 10a in a state of being sandwiched between the pair of sandwiching portions 22 and 23, and the pair of sandwiching portions 22 and 23 has recesses 22b and 23b. It is formed (see FIG. 11).

  The recesses 22b and 23b are formed by caulking the pliers 30 with the fixture 20 attached to the anticorrosion core 11 fitted to the tube end 10a. That is, between the pair of sandwiching portions 33, 33 of the pliers 30, the sandwiching portions 22, 23 of the fixture 20 attached to the pipe end portion 10a are sandwiched, and the pair of grips 32, 32 are gripped. 23 is caulked to form recesses 22b and 23b.

  In addition, the method for preventing corrosion of the tube end 10a using the fixture 20 in this embodiment is the same as the method for preventing corrosion of the tube end 10a in the above-described embodiment.

  In the clamping portions 22 and 23 of the fixture 20 crimped based on this method, the bottom portions of the recesses 22b and 23b pinch the anticorrosion core 11 from the inside and outside in the radial direction of the tube end portion 10a. Accordingly, as shown in FIG. 11, the holding portion 23 of the fixture 20 presses the anticorrosion core 11 not only at the both end edges R in the width direction but also at the bottom of the recess portion 23b in the center portion in the width direction. The anticorrosion core 11 is securely fixed to 10a.

DESCRIPTION OF SYMBOLS 1 Pipe 1a Receptacle 2 Subsequent pipe 2a Insert 3 Lock ring 4 Protrusion 5 Packing 6 Lining 7 Corrosion-proof core 10 Cast iron pipe 10a Pipe end part 11 Corrosion-proof core 11a Outer cylinder part 11b Inner cylinder part 20 Fixing tool 21 Base 22, 23 Holding part 22a, 23a Teeth 22b, 23b Recess 30 Plier 31 Plier main body 32 Grip 33 Holding part 33a Projection 34 Shaft 40 Fixing ring 41 One end 42 Other end 43 Long hole 44 Hole 45 Locking piece 50 Fixing piece 50a, 50b Holding part P Both side edges Q, R of the clamping part of the fixing piece Both side edges of the clamping part of the fixing tool

Claims (3)

  An anticorrosion core (11) is fitted to the pipe end (10a), and a fixture (20) having a U-shaped cross section is fitted to the anticorrosion core (11), and extends in the tube axis direction of the fixture (20). A pipe end anticorrosion structure in which the anticorrosion core (11) is sandwiched from the radially inner and outer sides of the pipe end (10a) by a pair of clamping parts (22, 23). The sandwiching portions (22, 23) have recesses (22b, 23b) extending along the tube axis direction formed by caulking of the tool, and the anticorrosion core is formed by the recesses (22b, 23b) of the fixture (20). A pipe end anticorrosion structure in which (11) is pressed against the pipe end (10a).   The clamping part (22, 23) of the fixture (20) has a plurality of teeth (22a, 23a) protruding toward the tube end (10a) on the inner surface thereof, and the plurality of teeth (22a, 23a). The pipe end anticorrosion structure according to claim 1, wherein the anticorrosion core (11) is bitten by being pressed by the recesses (22b, 23b) of the fixture (20).   A pair of the anticorrosion core (11) is fitted to the pipe end (10a), a U-shaped fixing tool (20) is fitted to the anticorrosion core (11), and a pair extending in the tube axis direction of the fixing part (20). The pair of sandwiching portions (22, 23) of the fixture (20) is sandwiched by the sandwiching portions (22, 23) so that the anticorrosion core (11) is sandwiched from the radially inner side of the tube end portion (10a). By caulking with a tool, recesses (22b, 23b) extending along the tube axis direction are formed in the clamping portions (22, 23), and the recesses (22b, 23b) of the fixture (20) are formed on the anticorrosion core ( 11) Pipe end anticorrosion method to be pressed.

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