JP3425461B2 - Loose flange structure of composite pipe - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite flange loose flange structure in which the outer surface of a synthetic resin tube is reinforced with a fiber reinforced resin layer. [0002] For example, as a means of transporting various chemical solutions,
In some cases, a synthetic resin-based composite tube that is relatively lightweight and has excellent corrosion resistance and strength is used. This is one in which the outer surface side of a tube made of a thermoplastic resin or the like is reinforced with a fiber reinforced resin layer. When such a composite pipe is connected to other pipes, valves, or other equipment, a so-called flange joint is often used. In this method, a flange is provided in advance at the end of a pipe or a pipe joint to be connected to each other, and one of the flanges is aligned with the flange of the other side and the two are fastened with bolts. Since the bolts are tightened by the bolts and the parts where the flanges are mounted, stresses due to thermal expansion and contraction of the pipes occur after connection, for example, due to fluctuations in ambient temperature. Sufficient strength is required. [0004] In order to meet such a demand, the present applicant has proposed a flange structure in which a peripheral portion of a flange of a composite pipe is reinforced with a metal core material in Japanese Patent Application No. 4-120484. This is a composite pipe having a flange formed at an end, in which a core member made of a metal flanged short pipe having a plurality of through holes is embedded from the back surface of the flange to the outer peripheral portion of the pipe main body. According to this, the fiber reinforced resin layer spreads in the through hole of the core material and inside and outside of the core material, and the fiber reinforced resin layer is provided on the back side of the flange and the outer peripheral portion of the pipe body by the anchor effect of the fiber reinforced resin layer in the through hole. Since the layer and the metal core material are firmly bonded, it is possible to sufficiently withstand the bolting load acting on the flange attachment portion and the axial stress due to thermal expansion and contraction applied to the flange mounting portion at the time of connection of the pipe or after the connection. However, in a structure in which a flange is fixed in advance to a pipe end as in the above-described flange structure, when the flanges are fastened with bolts, the positions of the bolt holes are limited. Since the tubes cannot be connected if they are displaced, one or both of the tubes or the like to be connected each time must be rotated by a required amount around the axis to correct the position of the bolt hole. This kind of positioning operation or connection position correcting operation is troublesome even with a relatively small-diameter pipe, but is particularly difficult with a large-diameter composite pipe used for transporting a chemical solution or the like. [0006] Such a problem can be solved by using a flange provided movably relative to the pipe body, that is, a loose flange. However, since the loose flange is generally movable not only in the circumferential direction but also in the axial direction, it may fall off from the pipe body during transportation or at the time of piping construction, or the piping work may be rather troublesome. . For example, in order from the bottom in the vertical direction, 2
When connecting these pipes, in order to prevent the upper loose flange from falling off the upper pipe, drop the upper loose flange to the bottom in advance, and in this state, tighten the bolt holes in the lower loose flange. While it is necessary to fasten both parts by adjusting the position to the position of the bolt hole of the loose flange of the lower pipe, also move the upper loose flange, which has been dropped to the bottom beforehand, to the upper part when fastening the lower pipe. And the fastening work becomes extremely troublesome. The present invention has been made in view of the above-mentioned circumstances in a conventional resin-based composite pipe, and can sufficiently withstand a bolt tightening load and thermal expansion and contraction of a pipe. An object of the present invention is to provide a loose flange structure of a composite pipe in which the flange does not fall off the pipe at the time of the above, and the positioning of the bolt hole can be easily performed. [0008] In order to achieve the above object, the present invention provides a composite pipe in which the outer surface side of a synthetic resin pipe is reinforced with a fiber reinforced resin layer, and a flange is formed at one end of the composite pipe. A loose flange structure of a composite pipe in which a loose flange is provided at a pipe end on a flange side is characterized in that it is configured as follows. That is, a metal outer tube is provided on the outer peripheral portion of the composite tube so that one end is located on the back surface side of the flange portion of the composite tube. While forming the protruding convex portion, a concave groove is formed in the circumferential direction of the inner peripheral surface of the loose flange to be rotatably fitted to the convex portion of the outer cylindrical tube, and the other end side of the outer cylindrical tube Is fixed with a fiber reinforced resin layer.
Teisu Ru. According to the above construction, a metal outer tube is provided on the outer periphery of the composite tube, and the convex portion formed at one end of the outer tube has a concave portion on the inner surface of the loose flange. Since the axial movement of the loose flange is regulated by the fitting of the groove, the loose flange does not fall off or fall from the composite pipe during transportation or during vertical piping. Further, the loose flange is rotatable in a state where the concave groove on the inner peripheral surface thereof is fitted to the convex portion of the outer tube, so that when the loose flange is connected to another tube or equipment, etc. By rotating the loose flange by a predetermined amount around the pipe axis, the positioning and correction of the bolt holes can be easily performed, and the flange connection work becomes easier accordingly. In addition, the outer tube fitted with the loose flange is made of metal, and the other end of the outer tube is made of fiber-reinforced wood.
By being fixed with a grease layer , the metal outer tube portion can receive all or a part of the bolting load, etc., and the flange portion of the composite tube, that is, the flange mounting portion, Since a load such as a bolting load that acts directly can be reduced, it is possible to sufficiently withstand a bolting load and stress due to thermal expansion and contraction. An embodiment of the present invention will be described below. FIG. 1 shows the appearance of the loose flange structure of the composite pipe according to the present embodiment, and FIG. 2 shows a longitudinal sectional view taken along the line II-II of FIG. 1 and omitting the left half thereof. As shown in these figures, the composite tube 1 has a synthetic resin tube 2 made of a thermoplastic resin (for example, vinyl chloride resin), and a fiber reinforced resin layer 3 for reinforcing the outer surface thereof. A flange portion 2a is formed at one end of the synthetic resin tube 2, and the above-mentioned fiber reinforced resin layer 3 is provided from the outer peripheral surface and the back surface of the flange portion 2a to the outer peripheral surface of the continuous tube. As a resin constituting such a fiber reinforced resin layer 3, for example, a glass fiber reinforced unsaturated polyester resin can be used. A metal loose flange 4 having a plurality of bolt holes 4a... 4a is provided on the outer peripheral portion of the composite pipe 1 on the flange 2a side. The loose flange 4 has an inner peripheral portion on one end 4b side (joining surface side) fitted to the flange portion 2a, and the other end 4c side located on the back surface side of the flange portion 2a. On the inner peripheral surface of the loose flange on the other end 4c side located on the rear surface side of the flange portion, a concave groove 4d forming a characteristic portion of the present invention is formed in the circumferential direction together with an outer tube described below. On the other hand, the outer tube 5 described above is provided on the outer periphery of the composite tube 1. The outer tube 5 is made of metal and has one end 5a located near the back surface of the flange 2a and the other end 5b embedded between the inner layer 3a and the outer layer 3b of the fiber reinforced resin layer 3. It is fixed in the state where it was put. On one end 5a side of the outer tube 5, an annular convex portion 5c protruding radially outward is formed in the circumferential direction, and the concave portion 4d of the loose flange 4 is formed in the convex portion 5d. By being rotatably fitted, the flange 4 can be rotated in the circumferential direction in a state in which movement in the direction of the tube end opposite to the flange 2a (upward in the state of FIG. 2) is restricted. It has become. According to the loose flange structure of the composite pipe 1 having such a configuration, the loose flange 4 is formed by the composite pipe 1
The concave groove 4d on the inner peripheral surface of the flange is fitted in the convex portion 5c of the metal outer tube 5 provided on the outer peripheral portion of the outer peripheral portion, so that the convex portion 5c causes the pipe end direction opposite to the flange portion 2a. (The upward movement in the state of FIG. 2) is restricted. Therefore, the loose flange 4 does not drop or fall from the composite pipe 1 during transportation or during vertical piping. Further, in this case, since the concave groove 4d on the inner peripheral surface of the loose flange is rotatably fitted to the convex portion 5c of the outer cylindrical tube 5, when connecting with another tube or equipment, etc. Just by rotating the loose flange 4 by a predetermined amount around the pipe axis, the position of the bolt hole 4a can be adjusted and the position can be corrected.
That facilitates the flange connection work. In the composite pipe 1 as described above, since one end 4b of the loose flange 4 is fitted to the flange 2a at the pipe end, the bolt hole 4a of the loose flange 4 is required to perform the flange connection operation. When tightening through a bolt (not shown) or when thermal expansion and contraction of the pipeline occurs after connection, the axial load caused by the bolt tightening load and thermal expansion and contraction of the pipeline will not only occur in the loose flange 4 but also in the pipe end. Collar part 2
Also acts on a. Therefore, if these loads cannot be tolerated, the loose flange 4 and the flange 2 as an attachment portion thereof are not provided.
a may be damaged. However, in the above embodiment of the present invention, since the loose flange 4 is made of metal, the flange 4 itself can sufficiently withstand a load such as a bolt tightening load. As for the flange 2a at the end of the tube, the loose flange 4 is fitted to the convex portion 5c of the metal outer tube 5 to restrict axial displacement, and the outer tube 5 itself is a composite tube 1. Is fixed in a state where one end 5b side is embedded in the fiber reinforced resin layer 3 provided on the outer peripheral portion, so that a part or all of a load such as a bolt tightening load applied from the loose flange 4 side is made of metal. Convex part 5c of outer tube 5
Therefore, the axial load acting directly on the flange portion 2a is reduced by that much. As a result, the flange 2 at the pipe end
The damage of the flange portion 2a, which may occur when a bolting load or the like directly acts on a, is prevented. Next, an example of a method for manufacturing the loose flange structure of the composite pipe will be described. First, as shown in FIG. 3, in a state where an outer tube material 5 'to be a metal outer tube 5 is inserted into the loose flange 4, it is fitted to a groove 4d provided in advance on the inner peripheral surface of the loose flange. By expanding the diameter of a predetermined portion (a portion shown by a chain line in the figure) at the end of the outer tube material 5 ', an annular convex portion 5c fitted into the concave groove 4d is formed. Such diameter expansion processing, that is, the formation of the convex portion 5c can be performed, for example, by pressing the peripheral surface of the outer tube material 5 'from inside to outside with a roller or the like (not shown). When the convex portion 5c is formed by enlarging a predetermined portion of the outer tube material 5 'in this manner, the loose flange 4 is fitted with the concave portion 4d of the inner peripheral surface thereof into the convex portion 5c of the outer tube 5 so as to form a peripheral portion. In such a manner as to be rotatable in any direction. Next, the loose flange 4 is attached to the composite pipe 1.
And the outer tube 5 is inserted in the direction of the arrow in the figure to fit the inner periphery of the loose flange 4 on one end 4b side into the flange 2a at the tube end of the composite tube 1 and the inner layer 3a of the fiber reinforced resin layer 3 The outer tube 5 is attached to the outer periphery of the outer tube, and in this state, the other end 5b of the outer tube 5 is fixed by the outer layer 3a of the fiber reinforced resin layer 3 as shown in FIG. Thereby, the loose flange structure of the composite pipe 1 as shown in FIG. 1 or FIG. 2 is obtained. Here, the outer layer 3a of the fiber reinforced resin layer 3 is formed by, for example, a spray-up method in which a glass chop and a curable resin such as an unsaturated polyester resin are sprayed, or a curable resin applied to a glass fiber woven or nonwoven fabric. It can be carried out using a hand lay-up method of impregnating and laminating. Since it is difficult to bond the metal and the fiber-reinforced resin, the outer tube is provided with, for example, (A) to (C) of FIG.
It is preferable to previously provide through holes, projections, and the like as shown in FIG. Among them, FIG. 1A shows a case where a rectangular through-hole 15d is provided in the peripheral wall of the outer tube 15 and FIG.
5 shows a case where a round through hole 25d is provided in the peripheral wall, and FIG. 5 (C) shows a case where a ridge 35d is provided in the outer peripheral surface of the outer tube 35 in the circumferential direction. Such a through hole 15
If the fiber reinforced resin layer 3 shown in FIG. 2 spreads in the through holes 15d, 25d and the periphery of the protrusion 35d, the outer cylindrical pipe against the axial load is formed by the anchor effect. And the fiber reinforced resin layer are securely connected, so that the outer tube is firmly fixed at a predetermined position on the outer peripheral portion of the composite tube. As described above, according to the present invention, the loose flange is rotatably fitted to the convex portion of the outer tube provided on the outer peripheral portion of the composite tube. The other end is a fiber reinforced resin layer
Since the loose flange is prevented from moving in the direction of the pipe end opposite to the flange of the composite pipe,
It is possible to prevent the loose flange from dropping or dropping from the composite pipe during transportation or during vertical piping. When connecting to other pipes or devices,
By rotating the loose flange by a predetermined amount around the pipe axis, it is possible to easily perform the alignment and position correction of the bolt holes, which facilitates the flange connection work and improves piping workability. Become. Further, when fastening bolts are passed through the bolt holes in the loose flange or when thermal expansion and contraction of the pipeline occurs, part or all of the bolting load and the stress caused by thermal expansion and contraction can be reduced by using an external metal. Since it can be handled by the convex portion of the cylindrical tube, the bolting load and the stress directly acting on the flange portion of the composite tube are alleviated accordingly. Thereby, it is possible to realize a loose flange structure of the composite pipe that can sufficiently withstand the bolting load and the stress caused by thermal expansion and contraction.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an appearance of a loose flange structure of a composite pipe according to one embodiment of the present invention. FIG. 2 is a longitudinal sectional view taken along line II-II of FIG. 1 and showing a right half thereof. FIG. 3 is an explanatory view showing one example of a method of manufacturing the loose flange structure, and showing a step of connecting an outer tube and a loose flange and then inserting the same into a composite tube. FIG. 4 is a perspective view showing a preferred example of an outer tube used in the present invention, wherein (A) shows an outer tube having a rectangular through hole formed in a peripheral wall in a state of being connected to a loose flange;
(B) is a perspective view showing a part of the outer tube provided with a round through-hole, and (C) is a perspective view showing a part of the outer tube provided with a ridge on a peripheral surface. [Description of Signs] 1 ... Composite pipe 2 ... Synthetic resin pipe 2a ... Flange 3 ... Fiber reinforced resin layer 4 ... Loose flange 4d ... Concave grooves 5, 15, 25, 35 ... outer cylinder tube 5c ... convex part

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16L 23/02

Claims (1)

(57) [Claim 1] A flange portion is formed at one end of a composite tube formed by reinforcing the outer surface side of a synthetic resin tube with a fiber reinforced resin layer, and a loose end is formed at the tube end on the flange portion side. A loose flange structure of a composite pipe provided with a flange, wherein a metal outer pipe is provided on an outer peripheral portion of the composite pipe so that one end is located on the back side of the flange section, On the one end side, a convex portion protruding radially outward is formed. On the other hand, the loose flange has a concave groove formed in a circumferential direction of an inner peripheral surface thereof and is rotatable on the convex portion of the outer tube. And the other end of the outer tube is
A loose flange structure of a composite pipe characterized by being fixed with a fiber reinforced resin layer .