JP2010019408A - Stainless steel pipe joint for inhibiting electric corrosion, and insulating spacer for stainless steel pipe joint for inhibiting electric corrosion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance attaching work efficiency compared with that in a prior art, to prevent a compression change of an insulating spacer caused by tightening a box nut in piping execution, to surely prevent damage by the deterioration of the compression of the insulating spacer or the like, and to enhance an yield of a product. <P>SOLUTION: The insulating spacer 6 attached to a straight pipe of a stainless steel pipe has a cylindrical part is formed with a diameter-expanded flange 6b at an end of the cylindrical part 6a is has a cut-in part in a stripe form over a longitudinal direction of the cylindrical part 6a and the flange 6b, and constituted to be developed into a half-cut state via the cut-in part, a wall thickness T of the cylindrical part 6a and a wall thickness t of the flange 6b are set to satisfy a relation of (the wall thickness T of the cylindrical part 6a)≥(the wall thickness t of the flange 6b), and the electric corrosion between the stainless steel pipe and the box nut is inhibited by the attached insulating spacer 6. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

Detailed Description of the Invention

  TECHNICAL FIELD The present invention relates to a stainless steel pipe joint for preventing electrolytic corrosion that can be manufactured at a low cost with better mounting workability than before, and an insulating spacer for a stainless steel pipe joint for preventing electrolytic corrosion.

  In recent years, flexible stainless steel pipes with bellows have been widely used as water supply pipes from the viewpoints of preventing red water generation due to high durability and absorbing the displacement due to earthquakes, constant vibrations, ground subsidence, etc. Yes. As such a water pipe, one end side of a stainless steel pipe is connected from a water supply pipe buried on a public road through a saddle water faucet and joints, and the other end side of the stainless steel pipe is connected to a stop cock through the joints. , Water faucets, etc. are connected and branched into the residential land.

  Moreover, in order to perform such piping work quickly and easily, a stainless steel pipe having an end structure as shown in FIG. 6 is used. That is, one end side (the right side in the figure) of the stainless steel pipe 1 having the bellows part 1a is a straight pipe part 1b, and an end part of the straight pipe part 1b is a flare end part 2, and the straight pipe part 1b and the flare end part are formed. A cap nut 3 made of brass, which is a dissimilar metal, is freely attached to 2, and a retaining line 4 inserted into an inner circumferential groove 3 b of the cap nut 3 is connected to the flange of the flare end 2 via a spacer 5. To prevent the cap nut 3 from coming off, and screw the male screw 3b formed on the inner peripheral surface of the cap nut 3 with a male screw of another member such as a joint to facilitate pipe connection work at the construction site. Like to do.

  Since the cap nut 3 is remarkably expensive when formed as a stainless steel one, conventionally, a cap nut made of brass, which is a metal different from the stainless steel pipe, is used, and the cap nut 3 made of brass is used. This prevents the occurrence of electric corrosion between different metals between the pipe and the stainless steel pipe 1.

  Moreover, since this kind of stainless steel pipe produces a deformation | transformation in a raw material structure, if the straight pipe part 1b is flared, it will be necessary to anneal in order to correct the deformation | transformation of a raw material structure. If the insulating spacer 5 made of resin is previously placed on the straight pipe portion 1b of the stainless steel pipe 1, the insulating spacer 5 may be damaged by heat at the time of annealing. When retrofitting to the straight pipe portion 1b, there is a situation that the inner through hole of the insulating spacer 5 cannot be inserted through the flare end portion having a diameter larger than the diameter of the inner spacer hole.

  In order to solve these problems, that is, the number of parts increases, the number of manufacturing processes increases, and the manufacturing is easily performed at low cost, and the insulating spacer 5 is mounted on the straight pipe portion 1b and the flare end portion 2 well. In order to solve problems such as inability to do so, technical means such as Patent Document 1 and Patent Document 2 have been used to solve the problem.

  The sleeve is generally used for insulation and bundling protection, and refers to a metal fitting that fits a rod shaft, etc., and the spacer refers to a small piece or thin piece that is sandwiched between two parts when they are spaced apart. Any expression of a sleeve or a spacer may be used, but in the present invention, it will be described as a spacer.

JP-A-8-312875 JP2001-173856

  By the way, the insulating spacer 5 must improve the mounting workability from the viewpoint of improving the product yield. Further, at the time of piping construction, it is necessary to prevent the insulation spacer 5 from being changed especially by tightening the cap nut 3 and to prevent damage.

  This invention was made based on such circumstances, and while improving the mounting workability as compared with the prior art, improving the compressive strength resistance of the insulating spacer by tightening the cap nut at the time of piping construction, It is an object of the present invention to provide a stainless steel pipe joint for preventing electrolytic corrosion that improves the product yield and an insulating spacer for the stainless steel pipe joint for preventing electrolytic corrosion.

In order to achieve the above object, the present invention has a flare end portion on one end side of a straight pipe portion of a stainless steel pipe as described in claim 1 as a stainless steel pipe joint for preventing electric corrosion, A stainless steel pipe to which a cap nut made of a dissimilar metal is attached so as to be loosely fitted through the flare end portion and the like, and has a cylindrical portion attached to the straight pipe portion of the stainless steel pipe, A flange portion having an enlarged diameter at the end portion, and a cut portion is provided in the longitudinal direction of the cylindrical portion and the flange portion, and is made of a resin that can be split in half through the cut portion. The thickness (T) of the cylindrical portion and the thickness (t) of the collar portion are the relationship of the thickness (T) of the cylindrical portion ≧ the thickness (t) of the collar portion. Set to
Electrolytic corrosion between the stainless steel pipe and the cap nut is prevented through the mounted insulating spacer. Further, as described in claim 2, a slit is formed by being provided from the end portion side of the cylindrical portion, and the resin member is made of polyamide resin or polyacetal. The collar portion is made of resin, and the thickness of the collar portion is set such that the thickness of the cylindrical portion (T) ≧ the thickness of the collar portion (t) at the time of molding, or molding It is characterized in that the thickness is later reduced and corrected through a correction tool.

  Moreover, as an insulating spacer of the stainless steel pipe joint for preventing electric corrosion, as described in claim 5, the cylindrical part is attached to the straight pipe part of the stainless steel pipe, and the diameter is expanded at the end of the cylindrical part. A flange portion is formed, and a cut portion is provided in the longitudinal direction of the cylindrical portion and the flange portion, and has an insulating spacer made of resin that can be developed in a split shape through the cut portion, The thickness (T) of the cylindrical portion and the thickness (t) of the collar portion are set so as to satisfy the relationship of the thickness (T) of the cylindrical portion ≧ the thickness (t) of the collar portion. Electrolytic corrosion between the stainless steel pipe and the cap nut is prevented through the insulating spacer. Further, as described in claim 6, from the end of the cylindrical portion, a slit is drilled and provided, and as described in claim 7, the resin member is made of polyamide resin or polyacetal. The collar portion is made of resin, and the thickness of the collar portion is set so that the thickness of the cylindrical portion (T) ≧ the thickness of the collar portion (t) at the time of molding, or molding It is characterized in that the thickness is later reduced and corrected through a correction tool.

  According to this invention, since the insulation spacer is attached and attached to the outer peripheral surface of the straight pipe portion and the flare end portion forming the end portion of the stainless steel pipe, the attachment workability is good and low. The installation process of the insulating spacer can be performed at a cost. Furthermore, since the inner periphery of the flange part of the insulating spacer is formed thinner than the cylindrical part, it is possible to improve the product yield of the insulating spacer by tightening the cap nut at the time of piping construction.

  Embodiments of the present invention will be described below in detail with reference to the drawings. 1 is an external perspective view showing an insulating spacer according to the present invention, FIG. 2 is a side view showing each side of the insulating spacer, FIG. 3 is an explanatory view showing a stainless steel pipe joint according to the present invention, and FIG. FIG. 5 is an explanatory view showing an example of forming the collar portion. In the description of the embodiment, FIG. 6 will be referred to, and the same parts as those in the prior art will be described with the same reference numerals.

  As shown in FIG. 3, the flexible stainless steel pipe 1 is a flexible stainless steel pipe having a bellows part 1 a, and one end side of the stainless steel pipe 1 is formed by a straight pipe part 1 b and a flare end part 2. The flare end portion 2 is formed as a flange having a diameter larger than that of the straight pipe portion 1b.

  The cap nut 3 is a brass cap nut that is normally used. An internal thread 3a is formed on the inner peripheral surface of the cap nut 3 and an inner peripheral groove 3b into which the retaining wire 4 is inserted. The inner diameter of the cap nut 3 is formed to be slightly larger than the diameter of the flange that is the flare end 2, so that the cap nut 3 is not obstructed by the flange of the flare end 2. It is inserted into the straight pipe portion 1b from the portion 2 side, and is freely attached to the straight pipe portion 1b.

  On the inner peripheral surface of the cap nut 3, when the retaining line 4 is inserted into the inner peripheral groove 3b formed on the inner peripheral surface, the retaining line 4 protruding from the inner peripheral groove 3b is the outer periphery of the flange of the flare end 2 To prevent the cap nut 3 from coming off.

  As shown in FIGS. 1 and 3, the insulating spacer 6 includes a cylindrical portion 6 a that covers the outer peripheral surface of the straight pipe portion 1 b, and a collar portion 6 b that is provided at one end of the cylindrical portion 6 a and contacts the flange of the flare end portion 2. And is formed by. In the longitudinal direction of the cylindrical portion 6a and the collar portion 6b, a notch portion 6c is provided as a one-piece cracked spacer, and is forcibly expanded and attached from the notch portion 6c when inserted.

  The insulating spacer 6 is provided with a slit 6d formed from one end side of the cylindrical portion 6a at a position opposite to the flare end portion 2, and promotes forced deployment of the insulating spacer 6.

  Further, as shown in FIG. 3, the collar portion 6b of the insulating spacer 6 is formed to be approximately the same as or thinner than the thickness of the cylindrical portion 6a. That is, the relationship is set such that the thickness (T) of the cylindrical portion 6a ≧ the thickness (t) of the collar portion 6b.

  In forming the collar portion 6b, the thickness (T) of the cylindrical portion 6a is equal to or greater than the thickness (t) of the collar portion 6b at the time of molding, or, as illustrated in FIG. The thickness of the inner periphery of the collar portion 6b can be reduced by cutting and straightening. Further, in this embodiment, the thickness (t) is as thin as 0.5 mm, and there is almost no compression allowance, so that the insulating spacer 6 is prevented from being biased even if the cap nut 3 is tightened too much, and the insulating spacer 6 and the like can be prevented from being damaged. In addition, the thickness of the collar part of a conventional product is about 2 mm-2.5 mm.

  The insulating spacer 6 is formed of a resin member, and in this embodiment is formed of a polyamide resin. However, it may be polyacetal or any other material that is suitable for forming this insulating spacer.

  The outer periphery of the flange portion 6b of the insulating spacer 6 is formed to have a slightly larger diameter than the flange of the flare end portion 2, and thereby the outer peripheral surface of the flange of the flare end portion 2 and the inner peripheral surface of the cap nut 3 The gap formed between the two is sealed.

  Further, depending on the relationship such as the load, the material of the insulating spacer 6, the formation thickness, etc., the shape of the retaining line 4 is not limited to a spherical shape, but may be an elliptical shape, for example, so as to equalize the pressing force.

Thus, according to this embodiment, the insulating spacer 6 can be easily rearranged by expanding the cut portion 6c while expanding the straight tube portion 1b of the stainless steel tube 1 to which the cap nut 3 is freely fitted in advance. Can be attached.
Further, the insulating spacer 6 covers the outer peripheral surface of the straight pipe portion 1b and the flare end portion 2, and is formed so as to be developed as a one-piece shaped spacer by the cut portion 6c in the longitudinal direction of the cylindrical portion 6a and the flange portion 6b. In addition, since it is forcibly unfolded and attached from the notch 6c at the time of insertion, it is possible to prevent electrolytic corrosion between the stainless steel pipe 1 and the cap nut 3 made of a different metal via the insulating spacer 6.

  Further, the insulating spacer 6 has a cylindrical portion 6a that covers the outer peripheral surface of the straight pipe portion 1b and a flange portion 6b that is provided at one end of the cylindrical portion 6a and that abuts against the flange of the flare end portion 2. The wall thickness is approximately the same as or thinner than the wall thickness. That is, since the relationship is set so that the thickness (T) of the cylindrical portion 6a ≧ the thickness (t) of the collar portion 6b, the mounting workability is improved as compared with the conventional case, and at the time of piping construction Of anti-corrosion stainless steel pipe joints that improve the compressive strength of insulating spacer 6 by tightening cap nut 3 and to improve the product yield, and provide insulating spacers for stainless steel pipe joints for preventing electric corrosion Can be provided.

It is an external appearance perspective view which shows the insulating spacer which concerns on this invention. It is a side view for explanation which shows each side of an insulating spacer. It is explanatory drawing which shows the stainless steel pipe joint which concerns on this invention. It is sectional drawing for description which shows the cross section of an insulating spacer. It is explanatory drawing which shows one example of shaping | molding of the collar part of an insulating spacer. It is sectional drawing for description which shows an example of the conventional stainless steel pipe end part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stainless steel pipe 1a Bellows part 1b Straight pipe part 2 Flare end part 3 Cap nut 4 Stopping wire 6 Insulation spacer 6a Cylindrical part 6b Collar part 6c Notch part 6d Slit

Claims (8)

In the stainless steel pipe which has a flare end on one end side of the straight pipe portion of the stainless steel pipe, and attaches the dissimilar metal cap nut so that it can be loosely fitted through the flare end etc.
It has a cylindrical part attached to the straight pipe part of the stainless steel pipe, and a flange part having an enlarged diameter is formed at an end part of the cylindrical part, and is cut in the longitudinal direction of the cylindrical part and the collar part. The portion is provided with an insulating spacer made of resin that can be split in half via the cut portion, and the thickness of the cylindrical portion (T) and the thickness of the collar portion (t) are: The thickness of the cylindrical portion (T) ≧ the thickness of the collar portion (t) is set, and the electrolytic corrosion between the stainless steel pipe and the cap nut is prevented through the attached insulating spacer. A stainless steel pipe joint for preventing electrical corrosion.   2. The stainless steel pipe joint for preventing electrolytic corrosion according to claim 1, wherein a slit is drilled and provided from the end side of the cylindrical portion.   The stainless steel pipe joint for preventing electrolytic corrosion according to claim 1 or 2, wherein the resin member is made of polyamide resin or polyacetal resin.   The thickness of the collar portion should be such that the thickness of the cylindrical portion (T) ≧ the thickness of the collar portion (t) at the time of molding, or that the thickness should be reduced and corrected through a correction tool after molding. The stainless steel pipe joint for preventing electrolytic corrosion according to claim 1, 2, or 3. It has a cylindrical part to be attached to the straight pipe part of the stainless steel pipe, a flange part having an enlarged diameter is formed at an end part of the cylindrical part, and a cut part extending in the longitudinal direction of the cylindrical part and the collar part Is provided, and has an insulating spacer made of resin that can be expanded in half through the cut portion, and the thickness (T) of the cylindrical portion and the thickness (t) of the collar portion are as described above. The thickness of the cylindrical portion (T) ≧ the thickness of the collar portion (t) is set, and the electrolytic corrosion between the stainless steel pipe and the cap nut is prevented through the attached insulating spacer. An insulating spacer for stainless steel pipe joints for preventing electrical corrosion.   2. An insulating spacer for a stainless steel pipe joint for preventing electrolytic corrosion according to claim 1, wherein a slit is formed by drilling from the end of the cylindrical portion.   The insulating spacer of the stainless steel pipe joint for preventing electrolytic corrosion according to claim 1 or 2, wherein the resin member is made of polyamide resin or polyacetal resin.   The thickness of the collar portion should be such that the thickness of the cylindrical portion (T) ≧ the thickness of the collar portion (t) at the time of molding, or that the thickness should be reduced and corrected through a correction tool after molding. The insulating spacer of the stainless steel pipe joint for preventing electric corrosion according to claim 5, 6 or 7.

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