JP2009156459A - Rust-proof means - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rust-proof means occupying no place in the outside of a pipe body. <P>SOLUTION: In a pipe joint equipped with a spigot part 12 constituting one metal-made fluid pipe and a socket part 5 constituting the other fluid pipe to which the spigot part 12 is inserted, the rust-proof means performs rust-proof processing with respect to a pipe end surface 12d exposed to the liquid directly by a metal material 1a of the spigot part 12 inserted into a socket part 5. The rust-proof means is at least provided with a metal block 14 comprising metal having the higher ionization tendency than the metal constituting the spigot part 12, and the metal block 14 is disposed in the socket part 5 into which the spigot part 12 is inserted so as to be electrically conducted with the pipe end surface 12d, and thereby, the metal block 14 can prevent rust on the pipe end surface 12d without exposing to the outside of the socket part 5, and the flexibity of attaching the metal block 14 to an inner surface of the socket part 5 or the spigot part 12 inserted into the socket part 5 can be secured. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is a pipe joint comprising: an insertion portion constituting one metal fluid pipe; and a receiving portion constituting the other fluid pipe into which the insertion portion is inserted. The present invention relates to a rust prevention means for performing a rust prevention treatment on a metal exposed portion in which a metal material of an insertion portion is directly exposed in the fluid.

  Conventionally, when one fluid pipe and the other fluid pipe are connected by, for example, metal water transport pipes with a joint, the length is adjusted by cutting the pipe body according to the situation at the installation site, etc. There is. Generally, the surface of such a metal tube body is coated with an anticorrosion paint or the like, but when cut as described above, the metal substrate is exposed on the tube end surface of the tube body. If installed as it is, there is a problem that the pipe end face is corroded by the fluid.

  Therefore, it is conceivable to coat the pipe end surface with anticorrosion paint after cutting, but because the work load at the site increases, lead wires are arranged outside the pipe body and the joint, and one fluid pipe and the other fluid One that electrically connects one end of the lead wire to the joint that maintains the connection with the tube, and connects the other end of the lead wire to the galvanic anode made of magnesium, to prevent rust of the water transport pipe is there. (For example, refer to Patent Document 1).

Japanese Utility Model Publication No. 58-6081 (page 3, FIG. 3)

  However, in Patent Document 1, since the lead wire and the galvanic anode are arranged outside the tube body, a space in which the lead wire and the electric means can be installed outside the tube body must be secured. There was a problem that the lead wires and electrical means took up space.

  The present invention has been made paying attention to such problems, and an object of the present invention is to provide a rust preventive means that does not take up space outside the tubular body.

In order to solve the above problems, the rust preventive means according to claim 1 of the present invention is:
An insertion portion constituting one metal fluid pipe;
A receiving part constituting the other fluid pipe into which the insertion part is inserted;
In a pipe joint comprising:
A rust preventive means for performing a rust preventive treatment on a metal exposed portion in which the metal material of the insertion portion inserted into the receiving portion is directly exposed in the fluid,
The rust prevention means includes at least a metal lump made of a metal having a larger ionization tendency than the metal constituting the insertion portion,
The metal lump is provided in a receiving portion into which the insertion portion is inserted so as to be electrically connected to the exposed metal portion.
According to this feature, since the metal lump having a greater ionization tendency than the insertion portion is provided in the receiving portion so as to be electrically connected to the metal exposed portion, the metal lump is exposed to the outside of the receiving portion. In addition to preventing the occurrence of rust in the exposed metal portion, the metal lump can be attached to the inner surface of the receiving portion or the insertion portion inserted into the receiving portion.

The rust prevention means according to claim 2 of the present invention is the rust prevention means according to claim 1,
The metal exposed portion is formed on the tube end surface of the insertion portion,
The metal lump is held in advance with respect to the insertion portion so as to be electrically connected to the metal exposed portion at a position facing the tube end surface.
According to this feature, even if the insertion portion that holds the metal block in advance is inserted into the reception portion with an appropriate insertion depth, the electrically conductive state can be maintained. Moreover, since the metal lump is held at a position facing the tube end surface, it is difficult to insert the both ends by holding the metal lump on the outer peripheral side of the insertion portion, and the inner lump of the metal lump is inserted. It is possible to avoid difficulty in circulating the fluid due to holding on the side.

The rust preventive means according to claim 3 of the present invention is the rust preventive means according to claim 2,
The rust prevention means includes a holding portion capable of holding the metal block with the pipe end surface, and a member extending from the holding portion along the outer peripheral surface of the insertion port and locking to the insertion port. And a cap body that is fitted to the pipe end surface.
According to this feature, the holding part holds the metal lump and the locking part maintains the held state by fitting the cap body to the insertion portion in a state where the metal lump is disposed at the facing position. It is possible to easily ensure the electrical continuity between the metal block and the tube end surface.

The rust preventive means according to claim 4 of the present invention is the rust preventive means according to claim 3,
The metal lump is formed in a ring shape along the circumferential direction of the tube end surface, and has a plurality of bulges that bulge toward the tube end surface at predetermined intervals along the circumferential direction. At least one of the projecting portions is in contact with the pipe end surface.
According to this feature, even if the tube end surface of the insertion portion has, for example, an uneven portion or an inclined portion in the circumferential direction and lacks smoothness, the metal mass formed in a ring shape has a predetermined interval in the circumferential direction. Any one of the plurality of bulges that are in contact with each other directly contacts the tube end surface, so that the electrical conduction state between the metal block and the tube end surface can be reliably maintained regardless of the smoothness of the tube end surface.

The rust preventive means according to claim 5 of the present invention is the rust preventive means according to claim 3,
The insertion part has a coating layer for anticorrosion formed on the outer peripheral surface of the metal material,
The rust prevention means further includes a conduction means that is continuous from the metal lump and extends along the inner surface of the locking portion of the cap body,
The conduction means has a pointed inner peripheral pointed portion toward the outer peripheral surface of the metal material,
The locking part of the cap body is locked to the outer peripheral surface of the insertion part, so that the inner peripheral cusp part peels off the coating layer of the insertion part and contacts the metal material.
According to this feature, only by fitting the cap body to the tube end surface of the insertion portion, no special peeling means is required using the force with which the locking portion is engaged with the outer peripheral surface of the insertion portion. In addition, since the coating layer of the insertion portion can be peeled off by the inner peripheral pointed portion of the conduction means and contacted with the metal material, the metal lump and the tube end face can be electrically conducted through the conduction means. Even if there is a case where relative movement in the tube axis direction occurs between the metal block and the insertion portion due to unexpected external force, etc., the coating layer is peeled off even at the position after the relative movement of the inner peripheral pointed portion. And maintain electrical continuity.

The rust prevention means according to claim 6 of the present invention is the rust prevention means according to claim 3,
The insertion portion has an anticorrosive coating layer formed on the outer peripheral surface of the metal material, and an exposed portion is formed where the metal material is exposed when at least a part of the coating layer is peeled off. And
The rust prevention means further includes a conduction means that is continuous from the metal lump and extends along the inner surface of the locking portion of the cap body,
The conduction means has a contact portion that contacts the exposed portion.
According to this feature, simply by fitting the cap body to the tube end surface of the insertion portion, the contact portion of the conduction means can come into contact with the exposed portion where the metal material of the insertion portion is exposed. The metal block and the pipe end surface can be electrically connected.

The rust preventive means according to claim 7 of the present invention is the rust preventive means according to claim 6,
An elastic member is provided on the surface side of the conducting means excluding the contact portion that faces the insertion portion,
The locking portion is pressed toward the outer peripheral surface of the insertion portion by the reception portion in a state where the insertion portion is inserted into the reception portion,
The abutting portion is characterized in that the elastic member is deformed when the locking portion is pressed against the receiving portion, and abuts on the exposed portion.
According to this feature, when the locking part is pressed toward the outer peripheral surface of the insertion part by inserting the insertion part into the reception part, the pressing force is uniformly distributed by the deformation of the elastic member. Therefore, even if the contact portion is not sufficiently in contact with the contact surface of the exposed portion, the contact can be ensured.

  Examples of the present invention will be described below.

  The embodiment of the present invention will be described with reference to the drawings. First, FIG. 1 is a schematic view showing the arrangement of pipe joints in the embodiment of the present invention, and FIG. FIG. 3A is a front view showing the rust prevention means, FIG. 3B is a right side view showing the rust prevention means, and FIG. It is AA expanded sectional drawing of (a), FIG.4 (a) is sectional drawing which shows the state in which the insertion part to which the antirust means was attached is inserted in the receiving part, (b) These are sectional drawings which show the state by which the insertion part to which the antirust means was attached was inserted in the receiving part, and FIG. 5 is an expanded sectional view which shows FIG.4 (b). Hereinafter, the left and right sides of FIG. 2 will be described as the left and right sides of the metal fluid pipe.

  First, as shown in FIG. 1 of the present embodiment, a pipe line 4 of the present invention includes, for example, a straight pipe 11 disposed in the ground, and an elbow pipe 2 having a curved portion in part along the pipe axis. Or a bend pipe 13 or the like having a curved portion and a relatively short length, and a fluid such as water and sewage and gas flows down a path formed inside the pipe.

  In particular, existing buried objects 3 such as existing pipes or existing cables are often buried in the ground, and it is inevitable to arrange the piping 4 while avoiding the buried objects 3. 2, a straight pipe 11 and a bend pipe 13 are appropriately combined, and the pipes can be connected to each other via the pipe joints 1 and 100 to form a desired pipe path. As described above, the types of members constituting the pipe line 4 are various, and the pipe joints connecting the respective members are required to be sealed without leaking the fluid flowing down inside the pipe.

  Further, at both ends of the elbow pipe 2, the straight pipe 11 and the bend pipe 13, a receiving portion 5 having a large diameter formed at one end in order to insert and connect one pipe body to the other pipe body. And the insertion portion 12 formed at the other end, and the insertion portion 12 and the receiving portion 5 constitute a part of the pipe joints 1 and 100.

  In addition, since the pipe joint 1 and each pipe joint 100 are configured in substantially the same manner, in the following, the pipe joint 1 including the receiving portion 5 of the elbow pipe 2 and the insertion portion 12 of the straight pipe 11 is referred to as a pipe joint. It will be described as an example, and description regarding the other pipe joint 100 will be omitted.

  As shown in FIG. 2, the pipe joint 1 in the present embodiment includes an elbow pipe 2 as a fluid pipe provided with a receiving portion 5 and an insertion portion 12 to be inserted into the inner peripheral surface of the receiving portion 5. Fluid leaks from the straight pipe 11 as a metal fluid pipe provided and between the inner peripheral surface of the receiving portion 5 having elasticity and the outer peripheral surface of the insertion portion 12 inserted into the receiving portion 5. The sealing member 8 for preventing the insertion, the cap body 23 fitted to the pipe end surface 12d of the insertion portion 12, the metal lump 14 provided inside the cap body 23, and the receiving portion 5 to the insertion portion 12 And an extraction restriction means 15 for restricting extraction.

  Although the connection of the pipe joint 1 will be described later, the insertion portion 12 is inserted into the receiving portion 5 in the insertion direction toward the right side in FIG. 2, and the removal restricting means 15 connects the receiving portion 5 to the insertion portion 12. Regulate withdrawal.

  The insertion portion 12 is formed with coating layers 12b and 12c, respectively, which are coated on the inner and outer peripheral surfaces of a metal material 12a made of ductile cast iron containing iron (Fe) and carbon with a rust preventive paint or the like. Has been. In the present embodiment, not only the insertion portion 12 but also the entire straight pipe 11 is made of ductile cast iron containing iron (Fe) and carbon. Furthermore, in the present embodiment, the coating layer 12b on the inner peripheral surface side of the metal material 12a, which is desired to have a high rust prevention effect because the fluid flows in the insertion portion 12, was applied to the outer peripheral surface of the metal material 12a. It is formed thicker than the coating layer 12c.

  Further, the inner diameter of the insertion portion 12 is substantially the same as the inner diameter of the inner peripheral surface 5 g of the elbow pipe 2, and the outer diameter of the insertion portion 12 is slightly smaller than the inner diameter of the receiving portion 5. Small diameter. In addition, the distal end of the insertion portion 12 has a tube end surface 12d formed along the circumferential direction continuous to the outer peripheral surface of the insertion portion 12 and the inner peripheral surface of the insertion portion 12. The tube end surface 12d is formed as a metal exposed portion where iron (Fe), which is a metal material of the insertion portion 12, is exposed by cutting the end portion of the straight tube 11 constituting the insertion portion 12. In addition, the metal exposure part is not necessarily restricted to what is formed in the pipe end surface 12d of the insertion part 12 like a present Example, For example, you may be formed in the outer peripheral surface of the insertion part 12. FIG.

  In the receiving part 5 of the elbow pipe 2 to which the seal member 8 is mounted, there are a recess 5a provided along the circumferential direction on the opening end side of the elbow pipe 2, and a pipe back side of the recess 5a in the circumferential direction. An accommodation groove 5e provided along the line is formed.

  A housing surface 5c that is substantially parallel to the tube axis C is formed on the inner peripheral surface of the tube rear side of the housing groove 5e. From the end of the housing surface 5c on the tube back side, the housing surface 5c is more A back end face 5d that is substantially perpendicular to the tube axis C is formed so as to be connected to the small-diameter inner peripheral face 5g. That is, a step is formed between the accommodation surface 5c and the back end surface 5d.

  The seal member 8 is inserted into a fitting portion 8 a that is fitted into a concave portion 5 a formed along the circumferential direction on the inner peripheral surface of the receiving portion 5, and the inner peripheral surface of the receiving portion 5 and the receiving portion 5. A valve portion 8c for watertightly sealing a gap between the insertion portion 12 and the outer peripheral surface of the insertion portion 12, and the outer diameter is a ring body having substantially the same diameter as the inner diameter of the receiving portion 5 to provide elasticity. It has a rubber body (see FIG. 4A).

  In a state where the seal member 8 is disposed in the receiving portion 5 and the insertion portion 12 is inserted into the receiving portion 5, the fitting portion 8a is fitted in the concave portion 5a in the circumferential direction, and the valve portion 8c. Is compressed in the receiving groove 5e (see FIG. 4 (a)), and as shown in FIG. 2, the valve portion 8c is compressed without the insertion portion 12 of the straight pipe 11 being inserted yet. In a state where the cross section is not formed, the cross-sectional shape is formed in a substantially circular shape, and the inner peripheral surface bulges toward the tube axis C as compared with the fitting portion 8a.

  The extraction restriction means 15 includes a plurality of bolt holes 5b formed at predetermined intervals in the circumferential direction on the outer peripheral surface in the vicinity of the outer end of the receiving portion 5, and a direction orthogonal to the tube axis C from the outside of the elbow pipe 2. And a plurality of push bolts 9 screwed into the bolt holes 5b, and a plurality of the bolts at predetermined intervals in the circumferential direction on the inner peripheral surface in the vicinity of the outer end of the receiving portion 5 (the present embodiment). 6 at intervals of 60 degrees), and a plurality of fixed claws 10 disposed in the arc groove 7 and having a sharp edge 10a at the tip. The outlet portion 5 and the insertion portion 12 are connected to each other by the removal restriction means 15 so that the removal of the insertion portion 12 from the reception portion 5 can be restricted.

  As shown in FIGS. 2 and 3A to 3C, the metal lump 14 is formed in a ring shape and is aluminum (Al) which is a metal having a higher ionization tendency than the metal material 12 a of the insertion portion 12. Consists of.

  The cap body 23 is provided in a ring shape along the circumferential direction of the metal lump 14, and a holding portion 16 that holds the metal lump 14 between the pipe end surface 12 d and a locking portion that locks the insertion portion 12. 29, and in the present embodiment, the cap body 23 and the metal lump 14 constitute a rust prevention means. In addition, the inner diameter of the holding portion 16 is slightly smaller than the outer diameter of the insertion portion 12 in a natural state, and the holding portion 16 extends slightly in the radial direction so that the tube end surface 12d side of the insertion portion 12 is located. The cap body 23 is attached to the insertion portion 12 by fitting and placing the metal lump 14 at a position facing the tube end surface 12d.

  In the abutting portion where the tube end surface 12d of the insertion portion 12 in the metal lump 14 abuts at the opposite position, the bulging portion 17 that bulges toward the tube end surface 12d of the insertion portion 12 has a predetermined interval along the circumferential direction. A plurality are formed at intervals (four in this embodiment at intervals of 90 degrees). The bulging portion 17 is formed so that the central portion in the circumferential direction bulges toward the insertion portion 12 side (the left side of the drawing in FIG. 3C) from the outer peripheral side and the inner peripheral side. A contact surface 17a of the projecting portion 17 with the tube end surface 12d is formed in a flat shape substantially parallel to the tube end surface 12d. In this embodiment, four bulging portions 17 are formed at intervals of 90 degrees, but two bulging portions 17 may be formed at intervals of 180 °, for example, or three or five at predetermined intervals. It may be formed as described above.

  As shown in FIG. 2 and FIG. 3C, the cap body 23 is formed in a substantially U shape in sectional view so that the locking portion 29 can be fitted into the outer peripheral surface of the insertion portion 12 from the holding portion 16. In addition, the holding portion 16 is enclosed along the outer peripheral surface 25 and the back surface 26 of the metal lump 14 and is integrally connected by welding or the like so that the metal lump 14 does not separate from the cap body 23, or is not necessarily integral. It is not necessary to connect to each other, as long as an electrical conduction state can be secured at the time of assembly.

  Further, as shown in FIGS. 3A and 3B, the locking portion 29 has a plurality of groove-like slits 28 cut out in the tube axis direction from the locking portion 29 side in the circumferential direction (this embodiment). 8 is formed at intervals of 45 degrees.) With this shape, the locking portion 29 can be bent radially outward by elastic force. In the state where the holding portion 16 is attached to the insertion portion 12, the axial centers of the insertion portion 12 and the holding portion 16 coincide with each other.

  Further, the holding portion 16 has a back surface 19 formed on the surface facing the back end surface 5d. The back surface 19 abuts on the back end surface 5d in a state where the cap body 23 is installed in the receiving portion 5. Therefore, the insertion port 12 is prevented from being excessively inserted into the receiving port 5 (see FIG. 4A). Further, as shown in FIG. 3C, the cap body 23 is formed with a circular hole 24 through which a fluid flows, and the inner peripheral surface of the circular hole 24 is the inner peripheral surface of the circular hole of the metal lump 14. It is formed so as to be substantially flush with 18.

  Next, the connection of the pipe joint 1 of the present invention will be described.

  As shown in FIG. 2, first, the locking portion 29 of the cap body 23 is inserted from the tube end surface 12 d side of the insertion portion 12, whereby the distal end side of the locking portion 29 is bent radially outward by the slit 28. The contact surface 17a of the bulging portion 17 and the tube end surface 12d are pushed by pushing the locking portion 29 toward the insertion portion 12 while the outer peripheral surface of the locking portion 29 and the outer peripheral surface of the insertion portion 12 are in close contact with each other. Contact at the opposite position. Thereby, the metal lump 14 and the pipe end surface 12d are in a state of electrical conduction.

  Next, the seal member 8 is inserted into the receiving port portion 5 from the tube end opening of the elbow tube 2, and the fitting portion 8 a is fitted into the recess portion 5 a of the receiving port portion 5. Note that the mounting operation of the seal member 8 in the receiving port 5 may be completed in advance at the shipping stage of the elbow pipe 2 or may be performed at the connection site of the pipe joint 1.

  When the insertion portion 12 to which the cap body 23 is attached is inserted into the tube end opening of the elbow pipe 2, a seal in which the outer peripheral surface of the insertion portion 12 is fitted to the inner peripheral surface of the receiving portion 5. As shown in FIG. 4A, the valve portion 8 c is inserted into the receiving portion 5 while being in sliding contact with the fitting portion 8 a of the member 8, and the outer periphery of the inserting portion 12 and the inner periphery of the receiving portion 5. It compresses with the accommodation groove | channel 5e formed along a circumferential direction with a surface. As a result, the gap between the inner peripheral surface of the receiving port 5 and the outer peripheral surface of the insertion port 12 is sealed, and fluid leaks from between the inner peripheral surface of the receiving port 5 and the outer peripheral surface of the insertion port 12. Is prevented.

  Further, the insertion port 12 is inserted into the back side of the tube, and as shown in FIG. 4B, the back surface 19 of the cap body 23 reaches the back end surface 5d, and the push bolt 9 is inserted while maintaining this state. Screwed in from the outside of the arc groove 7, the fixed pawl 10 is pressed against the outer peripheral surface of the insertion portion 12, the push-in bolt 9 is further screwed in, and the sharp blade 10a of the fixed pawl 10 is pressed toward the tube axis to insert the insertion portion. 12 is inserted into the outer peripheral surface of the connector 12 and the receiving portion 5 and the insertion portion 12 are connected. As a result, the pipe joint 1 is configured in a restricted state in which the removal of the insertion portion 12 from the receiving portion 5 is restricted.

  As shown in FIG. 5, in this embodiment, in a state where the pipe joint 1 is configured, a part of the pipe end surface 12 d of the insertion part 12 is exposed in the fluid in the receiving part 5. . The material of the tube end surface 12d is a metal material 12a containing iron (Fe), and the material of the metal lump 14 is aluminum (Al), which has a higher ionization tendency than iron (Fe), and the tube end surface 12d and the metal lump 14 Are in direct contact with each other and are in an electrically conductive state, so that a dissimilar metal battery in which the fluid is an electrolyte solution, the metal mass 14 is an anode, and the tube end surface 12d is a cathode is formed.

  Therefore, a potential difference is generated between the metal lump 14 and the tube end face 12d, and the metal lump 14 on the anode side is eluted as aluminum ions, and at the same time, electrons generated in the metal lump 14 flow toward the tube end face 12d. As a result, the metal lump 14 is consumed as a sacrificial anode, and the tube end surface 12d is not ionized, so that the exposed metal surface of the tube end surface 12d can be prevented from being rusted or corroded.

  Since these rust prevention effects continue until the metal lump 14 is exhausted, the size, shape, etc. of the metal lump 14 may be appropriately set according to the service life of the fluid pipe 1 and the like. Note that the metal lump is not necessarily limited to the one that directly contacts the tube end surface 12d of the insertion portion 12 as in the present embodiment as long as it is attached in a state of being electrically connected to the exposed metal portion. It may be attached to the inner surface of the mouth portion 5 or to the outer peripheral surface or inner peripheral surface of the insertion portion 12 inserted into the receiving portion 5.

  As described above, the rust preventive means of the first embodiment includes at least the metal block 14 made of a metal having a higher ionization tendency than the metal constituting the insertion portion 12, and the metal block 14 is electrically connected to the tube end surface 12d. Since the insertion portion 12 is provided in the insertion portion 5 in which the insertion portion 12 is inserted, the metal lump 14 can not only prevent the occurrence of rust on the tube end surface 12d without being exposed to the outside of the tube body. The metal lump 14 can be attached to the inner surface of the receiving portion 5 or the insertion portion 12 inserted into the receiving portion 5.

  Moreover, since the metal lump 14 is held in advance with respect to the insertion port 12 so as to be electrically connected to the tube end surface 12d at a position facing the tube end surface 12d, the insertion port 12 is connected to the receiving port. The electrical continuity can be maintained regardless of the insertion depth of the portion 5. That is, as in the present embodiment, the insertion portion 12 is not necessarily inserted into the receiving portion 5 until the back surface 19 of the cap body 23 reaches the back end surface 5d. For example, the back surface 19 and the back end surface 5d The insertion port 12 may be inserted into the receiving port 5 so as to form a predetermined gap therebetween. By doing in this way, since there exists a freedom degree with respect to an axial direction in the connection of the insertion part 12 and the receiving part 5, the freedom degree of piping work and the earthquake resistance after piping improve.

  Further, since the metal lump 14 is held at a position facing the pipe end surface 12d, the metal lump 14 is held on the outer peripheral side of the insertion portion 12, or the metal lump 14 is held on the inner peripheral side of the receiving portion 5. Therefore, it is possible to avoid the difficulty of inserting both the mouth portions and the difficulty of circulating the fluid.

  The cap body 23 includes a holding portion 16 that can hold the metal lump 14 between the tube end surface 12d, and a member that extends from the holding portion 16 along the outer peripheral surface of the insertion portion 12 and is locked to the insertion portion 12. Since the holding portion 23 holds the metal lump 14 by fitting the cap body 23 to the insertion portion 12 in a state where the metal lump 14 is disposed at the opposing position, The locked portion 29 can maintain this held state, and an electrical conduction state between the metal lump 14 and the tube end surface 12d can be easily ensured.

  The metal lump 14 is formed in a ring shape along the circumferential direction of the tube end surface 12d, and has a plurality of bulging portions 17 that bulge toward the tube end surface 12d at predetermined intervals along the circumferential direction. Therefore, even when the tube end surface 12d of the insertion portion 12 has a concavo-convex portion or an inclined portion in the circumferential direction, a plurality of metal lumps 14 formed in a ring shape are provided at predetermined intervals in the circumferential direction. Any one of the bulging portions 17 directly contacts the tube end surface 12d, so that the electrical conduction state between the metal lump 14 and the tube end surface 12d can be reliably maintained regardless of the smoothness of the tube end surface 12d.

  Next, Example 2 will be described below.

  Next, the rust prevention means according to the second embodiment will be described with reference to FIG. 6A is a front view of the rust prevention means in Example 2, FIG. 6B is a sectional view taken along line BB of FIG. 6A, and FIG. It is an expanded sectional view showing the state where a part was inserted in a mouth part. In addition, description of the same structure as Example 1 and the duplication is abbreviate | omitted.

  As shown in FIGS. 6A and 6B, the rust preventive means of the second embodiment includes a cap body 33 that is not formed with a bulging portion and is fitted to the pipe end surface 12d of the insertion portion 12. A metal lump 14 ′ having a flat facing surface 17 a ′ facing the tube end surface 12 d, and the metal lump 14 ′ are connected by welding or the like, and extend from the facing surface 17 a ′ to the inner surface of the locking portion 29 of the cap body 33. And a metal extending portion 31 as a conductive means extending in the direction. In the present embodiment, two metal extending portions 31 are formed at intervals of 180 °, but the present invention is not limited to this, and one or three or more metal extending portions 31 may be formed.

  Further, on the inner peripheral surface of the metal extending portion 31, an inner peripheral pointed portion 31a having a pointed shape is formed along the circumferential direction toward the outer peripheral surface of the metal material 12a. The inner diameter of 31 a is slightly smaller than the outer diameter of the insertion portion 12.

  The attachment of the cap body 33 will be described. When the engaging portion 29 engages the tube end surface 12d from the tube end surface 12d side, the engaging portion 29 engages with the outer peripheral surface of the insertion portion 12 by the force that engages the inner peripheral surface. The pointed portion 31a peels off the coating layer 12c of the insertion portion 12 and enters radially inward to contact the outer peripheral surface of the metal material 12a. Then, with the contact between the inner peripheral pointed portion 31a and the outer peripheral surface of the metal material 12a maintained, the cap body 33 is moved to the tube end surface 12d side until the facing surface 17a ′ further contacts the tube end surface 12d at the facing position. Push in. As a result, the cap body 33 moves the insertion portion 12 while the inner peripheral pointed portion 31a peels off the coating layer 12c of the insertion portion 12 and forms a notch 12f deeper than the coating layer 12c in the tube axis direction. Mating. Thereafter, as shown in FIG. 6C, the insertion portion 12 is inserted into the receiving portion 5, and the removal restriction means 15 restricts the removal of the insertion portion 12 from the receiving portion 5.

  In the state of FIG. 6C, the metal lump 14 ′ is electrically connected to the pipe end face 12d of the fluid pipe 1 through the metal extension part 31 including the inner peripheral pointed part 31a in contact with the outer peripheral face of the metal material 12a. Is conductive. Here, since the inner peripheral pointed portion 31a maintains a contact state with the outer peripheral surface of the metal material 12a, the metal lump 14 and the fluid pipe 1 are stably electrically connected via the metal extending portion 31. Conducted to. In this embodiment, the facing surface 17a ′ contacts the pipe end surface 12d and the cap body 33 fits the pipe end surface 12d, but the metal lump 14 and the fluid pipe 1 are electrically connected via the metal extending portion 31. If it is electrically connected, the cap body 33 may fit the pipe end face 12d so that the facing face 17a 'faces the pipe end face 12d without contact.

  By doing in this way, just by fitting the cap body 33 to the tube end surface 12d of the insertion portion 12, the locking portion 29 is engaged with the outer peripheral surface of the insertion portion 12, using a special force. Since the coating layer 12c of the insertion portion 12 can be peeled off and contacted with the metal material 12a by the inner peripheral pointed portion 31a of the metal extending portion 31 without the need for a peeling means, the metal extends through the metal extending portion 31. The lump 14 and the pipe end surface 12d can be electrically connected. Further, even if relative movement in the tube axis direction may occur between the metal lump 14 and the insertion portion 12 due to unforeseen external force or the like, the coating layer is also in the position after the inner peripheral cusp portion 31a is moved relatively. The electrical conduction state can be maintained by peeling 12c.

  Further, the shape and the like of the cap body 33 used in the second embodiment can be arbitrarily modified. The design may be changed as appropriate as in the following modifications. FIG. 7A is a front view of the rust prevention means in the modified example, FIG. 7B is a sectional view taken along the line CC of FIG. 7A, and FIG. 7C is an insertion portion to which the rust prevention means is attached. It is an expanded sectional view which shows the state by which was inserted in the receiving part. In addition, description of the same structure as Example 1, 2 and the duplication is abbreviate | omitted.

  As a modified example, as shown in FIG. 7 (c), a metal material is prepared by previously peeling a part of the coating layer 12c on the outer peripheral surface of the insertion portion 12 by a separate peeling means (not shown). Groove-shaped exposed portions 12e from which 12a is exposed are formed along the circumferential direction.

  Further, as shown in FIGS. 7A to 7C, a contact portion 31 a ′ that contacts the exposed portion 12 e is provided on the surface side of the metal extension portion 31 ′ that faces the insertion portion 12. An elastic member 32 made of rubber or the like is provided on the surface of the metal extension portion 31 ′ excluding the contact portion 31 a ′ that faces the insertion portion 12. It is provided outward from the contact surface of 31a '. Furthermore, the metal extension portion 31 ′ has elasticity that can be bent outward in the radial direction of the insertion portion 21 by the slit 28 formed in the circumferential direction.

  The attachment of the cap body 33 ′ will be described. When the distal end portion of the locking portion 29 of the cap body 33 ′ is inserted, each locking portion 29 is elastically deformed radially outward, and further, the contact portion 31a ′. The locking portion 29 on the side is elastically deformed by the contact between the contact portion 31a ′ and the tube end surface 12d, and then moves inward of the insertion portion 12 together with the other locking portions 29, and the tube end surface 12d. Is inserted until the abutting surface 17a ′ of the metal lump 14 ′ abuts, so that the inner surface of the abutting portion 31a ′ and the inner surface of the elastic member 32 are the outer peripheral surfaces of the exposed portion 12e and the inserting portion 12, respectively. Abut.

  When the contact portion 31a ′ reaches the exposed portion 12e, it is restored inward in the radial direction by the elastic return force of the metal extending portion 31 ′, so that the contact portion 31a ′ is securely contacted with the exposed portion 12e. Match.

  Thereafter, as shown in FIG. 7C, when the locking portion 29 is slightly pressed radially inward by inserting the insertion portion 12 into the receiving portion 5, the elastic member 32 is compressed. Since this pressing force is uniformly distributed and transmitted, even if the contact portion 31a ′ is not sufficiently in contact with the contact surface of the exposed portion 12e, the contact can be ensured. .

  By doing in this way, just by fitting the cap body 32 to the tube end surface of the insertion portion 12, the contact portion 31a 'of the metal extension portion 31' is exposed so that the metal material 12a of the insertion portion 12 is exposed. Since it can contact with the part 12e, the metal lump 14 and the pipe end surface 12d can be electrically connected via the metal extending part 31 ′.

  Although the embodiments of the present invention have been described with reference to the drawings, the specific configuration is not limited to these embodiments, and modifications and additions within the scope of the present invention are included in the present invention. It is.

  In the present embodiment, the cap bodies 23 and 33 are attached to the insertion portion 12 so that the metal lumps 14 and 14 'are kept electrically connected to the tube end surface 12d. You may attach a metal lump to the pipe end surface 12d of the insertion part 12 with a screw | thread etc. FIG. Alternatively, the metal lump may be disposed on the inner surface of the receiving portion 5 so as to maintain the electrical continuity between the metal lump and the tube end surface 12d.

  In the present embodiment, it is sufficient that at least the insertion portion 12 has a rust prevention effect, and the receiving portion may be a receiving portion formed of, for example, concrete as long as the material allows fluid to flow therein. It may be a metal receiving part. In the latter case, the receiving part is made of metal, and the metal lump is further arranged on the inner surface of the receiving part so as to electrically connect the metal lump and the receiving part. The mouth portion can also have an antirust effect.

  In addition to the above aluminum, the metal lumps 14 and 14 'may be made of an aluminum alloy having a relatively high ionization tendency, zinc or an alloy thereof, magnesium or an alloy thereof, or an alloy combining these three types. Any metal can be used as long as it meets the conditions of ionization tendency.

  Moreover, it is not restricted to what was comprised in ring shape like the metal lumps 14 and 14 ', for example, what was comprised by the arc shape along the inner peripheral surface of a cap body, or along a part of cap body It may be formed in one place.

  In addition, the metal extension portions 31 and 31 ′ may be any component that allows the metal lumps 14 and 14 ′ and the metal material 12a to be in an electrically conductive state, but are preferably made of a highly conductive material. .

It is the schematic which shows the arrangement | positioning condition of the pipe joint in the Example of this invention. It is sectional drawing which shows a receptacle part and the insertion part to which the antirust means was attached. (A) is a front view which shows a rust prevention means, (b) is a right view which shows a rust prevention means, (c) is an AA expanded sectional view of Fig.3 (a). (A) is sectional drawing which shows the state in which the insertion part to which the rust prevention means was attached is inserted in the receiving part, (b) is the insertion part to which the rust prevention means was attached. It is sectional drawing which shows the state inserted in the part. FIG. 5 is an enlarged cross-sectional view showing FIG. (A) is a front view of the rust prevention means in Example 2, (b) is BB sectional drawing of Fig.6 (a), (c) is the insertion part to which the rust prevention means was attached. It is an expanded sectional view which shows the state inserted in the opening part. (A) is a front view of the rust prevention means in the modified example, (b) is a sectional view taken along the line C-C in FIG. It is an expanded sectional view which shows the state inserted in the opening part.

Explanation of symbols

2 Elbow pipe (fluid pipe)
5 Receiving part 11 Straight pipe (metal fluid pipe)
12 Insertion portion 12a Metal material 12b Coating layer 12c Coating layer 12d Pipe end surface (metal exposed portion)
12e Exposed part 14, 14 'Metal lump 16 Holding part 17 Swelling part 23 Cap body 29 Locking part 31, 31' Metal extension part (conduction means)
31a Inner peripheral pointed portion 31a 'contact portion 32 elastic member 33, 33' cap body

Claims (7)

An insertion portion constituting one metal fluid pipe;
A receiving part constituting the other fluid pipe into which the insertion part is inserted;
In a pipe joint comprising:
A rust preventive means for performing a rust preventive treatment on a metal exposed portion in which the metal material of the insertion portion inserted into the receiving portion is directly exposed in the fluid,
The rust prevention means includes at least a metal lump made of a metal having a larger ionization tendency than the metal constituting the insertion portion,
Rust prevention means, wherein the metal block is provided in a receiving portion into which the insertion portion is inserted so as to be electrically connected to the exposed metal portion. The metal exposed portion is formed on the tube end surface of the insertion portion,
The said metal lump is previously hold | maintained with respect to the said insertion part so that it may electrically conduct with the said metal exposure part in the opposing position which opposes the said tube end surface. Rust prevention means.   The rust prevention means includes a holding portion capable of holding the metal block with the pipe end surface, and a member extending from the holding portion along the outer peripheral surface of the insertion port and locking to the insertion port. The rust prevention means according to claim 2, further comprising a cap body having a stop portion and fitted to the pipe end surface.   The metal lump is formed in a ring shape along the circumferential direction of the tube end surface, and has a plurality of bulges that bulge toward the tube end surface at predetermined intervals along the circumferential direction. 4. The rust preventive means according to claim 3, wherein at least one of the protruding portions is in contact with the pipe end surface. The insertion part has a coating layer for anticorrosion formed on the outer peripheral surface of the metal material,
The rust prevention means further includes a conduction means that is continuous from the metal lump and extends along the inner surface of the locking portion of the cap body,
The conduction means has a pointed inner peripheral pointed portion toward the outer peripheral surface of the metal material,
The locking portion of the cap body is locked to the outer peripheral surface of the insertion portion, so that the inner peripheral pointed portion peels the coating layer of the insertion portion and comes into contact with the metal material. Item 4. A rust preventive means according to item 3. The insertion portion has an anticorrosive coating layer formed on the outer peripheral surface of the metal material, and an exposed portion is formed where the metal material is exposed when at least a part of the coating layer is peeled off. And
The rust prevention means further includes a conduction means that is continuous from the metal lump and extends along the inner surface of the locking portion of the cap body,
4. The rust preventive means according to claim 3, wherein the conduction means has a contact portion that contacts the exposed portion. An elastic member is provided on the surface side of the conducting means excluding the contact portion that faces the insertion portion,
The locking portion is pressed toward the outer peripheral surface of the insertion portion by the reception portion in a state where the insertion portion is inserted into the reception portion,
The rust prevention means according to claim 6, wherein the abutting portion abuts on the exposed portion due to deformation of the elastic member when the locking portion is pressed against the receiving portion.

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