JP5631709B2 - Pipe fitting - Google Patents

Description

  The present invention relates to an insertion port formed at the distal end portion of one fluid pipe in the tube axis direction, and a receiving portion formed at the distal end portion of the other fluid pipe in the tube axis direction. An annular rust prevention member having an elastic member that rusts by pressing the tube end surface of the insertion portion by being inserted into the insertion portion, and having a holding portion that holds the elastic member with the tube end surface; And a pipe joint that is watertightly connected by inserting the insertion part into the receiving part.

  Conventionally, an anticorrosion ring (rust prevention member) provided with a ring main body that can be externally fitted to an end portion of a pipe body (fluid pipe) and an inward projecting piece formed in an inner diameter direction from an inner peripheral edge of one end portion of the ring main body. is there. Such an anticorrosion ring has a rubber adhesive (elastic member) disposed on the surface of the inwardly protruding piece on the side facing the tip surface (tube end surface) of the tube, and the anticorrosion ring is externally fitted to the tube. Thus, a rubber adhesive is adhered to the distal end surface of the tubular body to prevent rusting of the distal end surface of the tubular body (see, for example, Patent Document 1).

Japanese Utility Model Publication No. 7-22198 (page 5, Fig. 1)

  However, in the anticorrosion ring (rust prevention member) described in Patent Document 1, the anticorrosion ring is attached to the tip surface (tube end surface) of the pipe body (fluid pipe) until the rubber adhesive (elastic member) is dried. Is not completed, and there is a problem that the work efficiency at the site where the pipe joint is being constructed is lowered.

  This invention is made paying attention to such a problem, and it aims at providing the pipe joint which can attach a rust prevention member to the pipe end surface of an insertion part, without requiring time.

In order to solve the above problems, the pipe joint of the present invention is
An insertion opening formed at the distal end portion of one fluid pipe in the tube axis direction, a receiving portion formed at the distal end portion of the other fluid pipe in the tube axial direction, and the insertion portion An annular rust prevention member having an elastic member that rusts by pressing the tube end surface of the insertion portion by being inserted into the mouth portion, and having a holding portion that holds the elastic member with the tube end surface On the outer peripheral surface of the insertion portion, an engaged portion made of countless irregularities formed over the entire circumference by cooling the cast iron in the casting process of the fluid pipe and removing it from the mold. has, a pipe joint the spigot portion is connected in a watertight by being inserted into the socket portion,
The rust preventive member extends in a tapered shape that gradually decreases in diameter toward the insertion direction of the holding portion in the holding portion, and on the inner diameter direction side of the extending portion that is formed in an annular shape over the entire circumference. and the engaging portion is formed, the extension of the extended portion of the holding portion is fitted on the outer circumferential surface of the spigot portion, the elastic member by the holding portion in a state of being pressed toward the tube end face The engaging portion formed on the inner diameter direction side of the installation portion and the engaged portion on the outer peripheral surface of the insertion opening portion are engaged with each other in a concavo-convex manner.
According to this feature, the user simply inserts the rust preventive member toward the insertion portion at the construction site of the pipe joint, and covers the engagement portion without performing special processing on the insertion portion. Since the elastic member can be pressed and held on the pipe end surface in the state of engaging with the engaging portion, the positioning of the rust preventive member on the pipe end surface is aligned in the circumferential direction between the insertion portion and the rust preventive member. Can be completed in less time.

The pipe joint of the present invention is
A plurality of the engaging portions are provided apart from each other in the tube axis direction.
According to this feature, after the rust preventive member is attached to the insertion portion and the insertion portion is inserted into the receiving portion, the uneven engagement with the engaged portion is released due to deterioration or the like of some of the engagement portions. However, it is possible to maintain the attachment of the rust preventive member to the insertion portion by the concave and convex engagement with the engaged portion of the other engaging portion, and to continue the rust prevention of the pipe end surface.

The pipe joint of the present invention is
The holding portion and the elastic member include an adjusting portion that can adjust a protruding length of the one fluid pipe in the tube axis direction so as not to protrude from the inner diameter side end of the insertion port. It is characterized by.
According to this feature, the drag that the rust prevention member receives from the fluid flowing in one fluid pipe and the other fluid pipe can be reduced, and the rust prevention of the pipe end surface of the insertion portion by the rust prevention member can be easily continued. . Further, when cleaning the inside of one fluid pipe and the other fluid pipe, the pipe moving body for pipe cleaning that moves in the one fluid pipe and the other fluid pipe does not contact the holding portion and the elastic member. The inside of one fluid pipe and the other fluid pipe can be cleaned smoothly.

The pipe joint of the present invention is
The elastic member is made of a low rebound elastic material.
According to this feature, the elastic member is pressed against the tube end surface by inserting the rust preventive member into the insertion portion. For example, even if the tube end surface of the insertion portion is not a flat surface, the low resilience elastic material Since the shape of the elastic member can be easily deformed according to the shape of the tube end surface and can be brought into close contact with the tube end surface, rust prevention of the tube end surface can be performed more reliably.

It is a disassembled sectional view of a pipe joint which shows a mouth part and an insertion part in Example 1. (A) is a front view which shows a rustproof cover, (b) is AA sectional drawing of the rustproof cover in Fig.2 (a). It is sectional drawing which shows the attachment to the insertion part of a rust prevention cover. (A) is sectional drawing which shows the state which the rust prevention cover rusted the pipe end surface of the insertion part, (b) is sectional drawing which shows the state in which the insertion part was inserted in the receiving part. . (A) is sectional drawing which shows the state which attached the antirust cover to the insertion part, (b) is sectional drawing which shows the state which cut | disconnected the holding piece part and anticorrosion rubber which are long in length It is. It is sectional drawing of the antirust cover in Example 2. It is sectional drawing of the antirust cover in Example 3. It is sectional drawing of the antirust cover in Example 4. It is sectional drawing which shows the state which attached the antirust cover in Example 5 to the insertion part.

  EMBODIMENT OF THE INVENTION The form for implementing the pipe joint which concerns on this invention is demonstrated below based on an Example.

  The pipe joint according to the first embodiment will be described with reference to FIGS. 1 to 5. Hereinafter, in this embodiment, the left side of the paper surface in FIGS. 1, 2B, 3, 4A, and 4B is the front side (front side) of the anticorrosion cover, and FIG. ) Is the front side (front side) of the anticorrosion cover. Reference numeral 1 in FIG. 1 is a pipe joint to which the present invention is applied.

  As shown in FIG. 1, the pipe joint 1 in this embodiment includes a fluid pipe 2 in which a receiving part 2 a is formed at the tip part in the tube axis C direction, and a receiving part 2 a in the tip part in the tube axis C direction. A fluid pipe 3 in which an insertion portion 3a is inserted, a seal member 4 that has elasticity and prevents leakage of fluid from between the receiving portion 2a and the insertion portion 3a, and an insertion portion The anticorrosive cover 5 as an antirust member in the present invention for antirusting the pipe end surface 3b of 3a. These fluid pipes 2 and 3 are, for example, water pipes for flowing clean water as a fluid therein.

  In this embodiment, these fluid pipes 2 and 3 are ductile cast iron pipes manufactured by pouring ductile cast iron into a mold and then cooling. Although not shown in the drawings, the inner surface of a ductile cast iron pipe mold has innumerable irregularities stamped over substantially the entire surface so that the fluid pipes 2 and 3 can be easily detached from the mold after the casting of the fluid pipes 2 and 3. Yes.

  For this reason, as shown in FIG. 3, the fluid pipes 2, 3 are made of ductile cast iron that is poured into the concavo-convex part of the mold in the casting process, so that the ductile cast iron is cooled and removed from the mold. An engaged portion 3e having a plurality of recesses 3g is formed over substantially the entire circumference of the outer peripheral surfaces 3c of the second and third (the outer peripheral surface of the fluid pipe 3 is not shown).

  The fluid pipes 2 and 3 of this embodiment are cast by a gravity casting method, a die casting method, a centrifugal casting method, or the like. In particular, when the fluid pipes 2 and 3 are cast by the centrifugal casting method, a frictional force is applied to the liquid ductile cast iron that performs centrifugal motion in the mold by the innumerable recesses formed on the inner surface of the mold. It is possible to cast the fluid pipes 2 and 3 with less deviation.

  Furthermore, the fluid pipes 2 and 3 are configured such that a rust preventive paint (not shown) is applied over substantially the entire circumference of the outer peripheral surface 3c after casting, and this rust preventive paint is applied to the recessed portion of the engaged portion 3e. By accumulating, the rust prevention effect of the outer peripheral surface 3c of the fluid pipes 2 and 3 is increased.

  The front end of the receiving portion 2a is formed on the inner peripheral surface 2b whose inner diameter is larger than the outer diameter of the insertion portion 3a. A plurality of recesses 2c that open toward the tube axis C are formed at the tip of the receiving portion 2a over the circumferential direction of the receiving portion 2a. In these recesses 2c, a fixed claw 6 made of a metal material or the like and having a sharp blade 6a at the end facing the tube axis C side is disposed.

  Further, a plurality of bolt holes 2d are formed at predetermined intervals in the circumferential direction at the tip of the receiving portion 2a. These bolt holes 2d communicate with different concave portions 2c, and are bolted with bolts 7. For this reason, the fixed claw 6 is pressed toward the tube axis C by screwing in the bolt 7. An annular fitting groove 2e for fitting a fitting portion 4a (described later) of the seal member 4 closer to the insertion direction of the insertion portion 3a than the recess 2c in the inner peripheral surface 2b of the receiving portion 2a. Is formed.

  On the back side of the fitting groove 2e on the inner peripheral surface 2b of the receiving portion 2a, it is substantially perpendicular to the tube axis C so as to be connected to the inner peripheral surface 2g having a smaller diameter than the tip of the receiving portion 2a. An annular back end face 2h is formed.

  As shown in FIG. 1, a lining layer 3 f is formed on the inner peripheral surface 3 d of the fluid pipe 3 by mortar as a rust prevention treatment for preventing rust from the fluid flowing in the fluid pipes 2 and 3. . For this reason, the insertion part 3a has a longer wall thickness than the dimension in the radial direction of the rust preventive rubber 5a and the holding piece part 5d described later. In this embodiment, the lining layer 3f is made of mortar having a sufficient thickness for rust prevention. However, if the inner peripheral surface 3d of the fluid pipe 3 can be rust-prevented, the lining layer 3f is made thinner. You may form, for example, you may comprise with a thin coating layer by the powder coating material which consists of a rust preventive material.

  As shown in FIGS. 1 and 4A, the seal member 4 includes a fitting portion 4a fitted in the fitting groove 2e. Further, the fitting portion 4a has a valve portion for watertightly sealing a gap between the inner peripheral surface 2b of the receiving portion 2a and the outer peripheral surface 3c of the insertion portion 3a inserted into the receiving portion 2a. 4b bulges out.

  As shown in FIG. 1, FIG. 2 (a) and FIG. 2 (b), the rust preventive cover 5 is an elastic member in the present invention for rusting the tube end surface 3b of the insertion portion 3a over the entire circumference. The ring-shaped antirust rubber 5a and the guide ring 5b as a holding portion in the present invention for holding the antirust rubber 5a between the insertion portion 3a when the pipe end surface 3b is rusted. Has been. The guide ring 5b is made of a soft resin material having an annular elasticity in a front view, and the rust preventive rubber 5a is a low rebound elastic material, that is, a material having a relatively low rebound elastic modulus, and has an adhesive force. It is comprised by the butyl rubber which has.

  Further, as shown in FIG. 2 (b), the guide ring 5b faces in the front-rear direction of the rust preventive cover 5 and is formed in an annular shape over the entire circumference of the guide ring 5b. It consists of a piece 5c and a holding piece 5d extending from the rear end of the outer peripheral piece 5c toward the inner diameter direction of the rust preventive cover 5, and the guide ring 5b is shown over the entire circumference. It is formed in a substantially L shape in a sectional view shown in 2 (b).

  Among these, the outer peripheral piece part 5c is formed in the taper shape gradually diameter-reduced toward the front side of the antirust cover 5. FIG. Further, on the inner peripheral surface 5e of the outer peripheral piece 5c, a protrusion 5f as an engaging portion in the present invention is separated in the tube axis C direction over the entire circumference in the circumferential direction of the outer peripheral piece 5c. It is installed.

  Further, as shown in FIG. 2B and FIG. 3, the rust preventive rubber 5a and the holding piece 5d have dimensions of substantially the same length in the radial direction of the guide ring 5b. The holding piece 5d is fixed to the front side with an adhesive or the like. As shown in FIGS. 2 (a) and 2 (b), the groove portion 5g is rust-proof at the end portion on the inner diameter side of the rust preventive rubber 5a over the entire circumference of the rust preventive rubber 5a. It is formed so as to open toward the front side of the rubber 5a.

  Similarly, at the end of the holding piece portion 5d on the inner diameter side of the guide ring 5b, the groove portion 5h opens toward the back side of the guide ring 5b over the entire circumference in the circumferential direction of the holding piece portion 5d. Is formed. These groove portions 5g and 5h constitute the adjustment portion in the present invention and are opposed in the direction of the tube axis C. As will be described later, the user places the rust preventive rubber 5a and the holding piece portion 5d along the groove portions 5g and 5h. By cutting, the dimensions of the rust preventive rubber 5a and the holding piece 5d in the radial direction can be adjusted to be short. The grooves 5g or the grooves 5h are not necessarily limited to those formed over the entire circumference in the circumferential direction as in this embodiment. For example, the grooves 5g or the grooves 5h are formed in a perforated shape at predetermined intervals along the circumferential direction. It doesn't matter.

  Next, connection of the fluid pipes 2 and 3 using the pipe joint 1 configured as described above will be described. First, as shown in FIG.1 and FIG.3, the antirust cover 5 is arrange | positioned on the pipe axis C of the fluid pipe 3, and the front side of the antirust cover 5 is made to oppose the pipe end surface 3b of the insertion part 3a. Then, the outer peripheral piece 5c formed in a tapered shape that gradually decreases in diameter toward the front side of the rust preventive cover 5 is slid onto the outer peripheral surface 3c in a state where the distal end is expanded in diameter by pressing the outer peripheral piece 5c against the insertion opening 3a. The rust preventive rubber 5a is pressed toward the tube end surface 3b by the holding piece 5d by inserting the rust preventive cover 5 toward the tube end surface 3b of the insertion port 3a while being in contact therewith.

  By pressing the rust preventive rubber 5a against the pipe end surface 3b by the holding piece 5d, the protrusions 5f and 5f are engaged with the recess 3g by the restoring force in the diameter reducing direction of the outer peripheral piece 5c, and the rust preventive rubber. 5a is elastically deformed into a shape that is in close contact with the tube end surface 3b and is in close contact with the tube end surface 3b. The rust preventive rubber 5a is bonded to the pipe end surface 3b in the elastically deformed state by the adhesive force of the rust preventive rubber 5a itself made of butyl rubber, and has low rebound resilience possessed by the rust preventive rubber 5a itself made of butyl rubber. By the force to be elastically restored in the range of the above, the protrusions 5f, 5f protruding from the outer peripheral piece 5c are more strongly engaged with the recesses 3g formed in the engaged portion 3e.

  Due to the concavo-convex engagement between each of the protrusions 5f and 5f and the engaged portion 3e, the rust prevention cover 5 is pressed in the radial direction by the outer peripheral piece 5c disposed on the outer diameter side of the insertion opening 3a. Positioning is performed with respect to the mouth 3a. Furthermore, the rust preventive rubber 5a is elastically deformed between the holding piece portion 5d and the tube end surface 3b and held in close contact with the tube end surface 3b, and the attachment of the rust preventive cover 5 to the insertion portion 3a is completed.

  In addition, since the thickness of the insertion part 3a is formed longer than the dimension of the rust prevention rubber 5a and the holding piece part 5d in the radial direction, the rust prevention rubber 5a and the holding piece part 5d are formed on the pipe end face 3b. The end portion on the inner diameter direction side is disposed on the outer diameter side with respect to the inner diameter side end portion of the lining layer 3f while preventing the side made of ductile cast iron, which is the outer peripheral side, from being rusted. For this reason, the end portions on the inner diameter side of the rust preventive rubber 5 a and the holding piece portion 5 d can suppress the drag received from the fluid flowing in the fluid pipes 2 and 3 to a small value.

  And after fitting the fitting part 4a of the sealing member 4 over the perimeter of the fitting groove 2e as shown in FIG. 4 (a) and FIG.4 (b), the antirust cover 5 was attached. The valve portion 4b is elastically deformed by the outer peripheral surface 3c of the insertion portion 3a and the inner peripheral surface 2b of the reception portion 2a by inserting the insertion portion 3a into the receiving portion 2a until it comes into contact with the back end surface 2h. However, the space between the insertion portion 3a and the receiving portion 2a is sealed in a watertight manner.

  Finally, as shown in FIG. 4 (b), each of the bolts 7 is screwed to cause the sharp blade 6a of each fixing claw 6 to bite into the outer peripheral surface 3c of the insertion portion 3a to receive the insertion portion 3a. It fixes in the opening part 2a, and the connection of the fluid pipes 2 and 3 is completed. For this reason, rust prevention by the rust preventive rubber 5a is maintained while the rust preventive rubber 5a and the holding piece 5d are sandwiched between the pipe end face 3b of the insertion opening 3a and the back end face 2h of the receiving opening 2a. In the present embodiment, the insertion port 3a with the antirust cover 5 attached in this way is inserted into the receiving port 2a until it abuts against the back end surface 2h, and the anticorrosion rubber 5a prevents the tube end surface 3b from being rusted. However, since the rust prevention of the pipe end surface 3b by the rust prevention rubber 5a has already been made at the time when the rust prevention cover 5 is attached to the insertion portion 3a, the insertion portion 3a is located in the receiving portion 2a. It is not necessary to insert until it contacts the end face 2h.

  In addition, the fluid pipes 2 and 3 made of ductile cast iron as described above are cast in various dimensions within the range of tolerances, but the protrusions 5f and 5f of the rust preventive cover 5 are For any fluid pipe of any outer diameter that is cast within the tolerance range, it projects so as to engage with the engaged portion of the fluid pipe. More specifically, when the outer diameter of the fluid pipe is relatively short within the tolerance range, the diameter is gradually reduced toward the front side of the rust preventive cover 5 as shown in FIG. The protrusion 5f on the front side (the left side in the drawing) of the outer peripheral piece 5c formed in a tapered shape engages more deeply with the engaged portion 3e of the fluid pipe 3, and the outer diameter of the fluid pipe has a tolerance. In the case of a relatively long size within the range, although not shown in particular, both protrusions of the outer peripheral piece elastically deformed substantially parallel to the outer peripheral surface of the fluid pipe are both engaged parts of the fluid pipe. Engage deeply with the concave and convex.

  Furthermore, in the present embodiment, the thickness of the insertion portion 3a is formed longer than the radial dimension of the rust preventive rubber 5a and the holding piece portion 5d, and the rust prevention cover 5 is formed on the tube end surface of the insertion portion 3a. The end portions on the inner diameter side of the rust preventive rubber 5a and the holding piece portion 5d are suppressed to be received by the fluid flowing in the fluid pipes 2 and 3 by inserting them toward 3b, but FIG. 5 (a) and FIG. As shown in FIG. 5 (b), the thickness of the insertion port 3a is formed shorter than the radial dimension of the rust preventive rubber 5a and the holding piece 5d, and the inner diameter of the rust preventive rubber 5a and the holding piece 5d. When the end on the side protrudes toward the inner diameter side of the insertion opening 3a, the user cuts out the inner diameter side ends of the rust preventive rubber 5a and the holding piece 5d along the grooves 5g and 5h, and While maintaining the rust prevention of the side composed of ductile cast iron which is the outer peripheral side of the end surface 3b, the radial dimension of the rust prevention rubber 5a and the holding piece 5d The can end of the inner diameter side of the anticorrosive rubber 5a and holding pieces 5d are adjusted to the dimensions as not to protrude on the inner diameter side of the inserting portion 3a.

  In addition, even if the rust preventive cover 5 in this embodiment moves in a direction away from the insertion portion 3a due to the drag of the fluid flowing in the fluid pipes 2 and 3, to the pipe end surface 3b due to the adhesive force of the rust preventive rubber 5a. As the rust preventive rubber 5a restores itself in the direction of the tube axis C, the engagement of the protrusions 5f and 5f with the recess 3g is strengthened so that the rust prevention of the tube end surface 3b can be maintained. It has become.

  Moreover, since the rust preventive rubber 5a in this embodiment is composed of butyl rubber having excellent acid resistance, alkali resistance, heat resistance, etc., the fluid pipe to which the rust preventive cover 5 of this embodiment is applied is a water pipe. In addition, the present invention can be applied to a fluid pipe in which chemicals, hot water, etc. flow as fluids.

  As described above, in the pipe joint 1 according to the present embodiment, the rust preventive cover 5 protrudes toward the inner diameter direction side of the outer peripheral piece portion 5c extending in the insertion direction of the guide ring 5b into the insertion portion 3a. A portion 5f is formed, and an engaged portion 3e having a plurality of irregularities is formed on the outer peripheral surface 3c of the insertion portion 3a over the entire circumference of the outer peripheral surface 3c when the fluid pipe 3 is manufactured. Since the protrusion 5f and the engaged portion 3e are engaged with each other in a state where the rust preventive rubber 5a is pressed toward the pipe end surface 3b by the holding piece 5d, the user can perform the operation at the construction site of the pipe joint 1 or the like. The elastic member in a state in which the protrusion 5f is unevenly engaged with the engaged portion 3e only by inserting the rust-proof cover 5 toward the insertion portion 3a without performing special processing on the insertion portion 3a. Can be pressed and held on the pipe end face 3b, so that the antirust cover 5 is attached to the pipe end face 3b. , Without having to perform a circumferential alignment between the spigot portion 3a and the rust-preventing cover 5 can be completed without requiring time.

  Further, since a plurality of protrusions 5f are provided apart from each other in the tube axis C direction, after attaching the rust prevention cover 5 to the insertion portion 3a and inserting the insertion portion 3a into the receiving portion 2a, Even if the projection 5f of the projection is released from the concave-convex engagement with the engaged portion 3e due to deterioration or the like, the insertion portion of the rust-proof cover 5 by the concave-convex engagement with the engaged portion 3e of the other projection 5f The attachment to 3a can be maintained and rust prevention of the pipe end surface 3b can be continued.

  Further, the guide ring 5b and the rust preventive rubber 5a are provided with grooves 5g and 5h that can adjust the projecting length of the fluid pipe 3 in the direction of the tube axis C so as not to project from the inner diameter side end of the insertion port 3a. Since the antirust cover 5 is provided, the drag received from the fluid flowing in the fluid pipe 3 and the fluid pipe 2 is reduced, and the antirust of the pipe end surface 3b of the insertion portion 3a by the antirust cover 5 is easily continued. be able to. Further, when cleaning the fluid pipe 3 and the fluid pipe 2, a pipe cleaning moving body that moves in the fluid pipe 3 and the fluid pipe 2 contacts the guide ring 5 b and the rust preventive rubber 5 a. The fluid pipe 3 and the fluid pipe 2 can be smoothly cleaned without contact.

  Further, since the rust preventive rubber 5a is made of a low resilience elastic material, for example, by inserting the rust preventive cover 5 into the insert opening 3a and pressing the rust preventive rubber 5a against the pipe end surface 3b, for example, the insert insert Even if the tube end surface 3b of the portion 3a is not a flat surface but is formed into an uneven surface by cutting or the like, the shape of the rust preventive rubber 5a made of butyl rubber which is a low-rebound resilience material can be easily set according to the uneven surface shape of the tube end surface 3b Therefore, the pipe end surface 3b can be rust-prevented more reliably.

  Next, the pipe joint according to the second embodiment will be described with reference to FIG. In addition, the same structure as the said Example and the overlapping structure are abbreviate | omitted. Hereinafter, the left side of FIG. 6 will be described as the front side (front side) of the antirust cover.

  As shown in FIG. 6, the inner peripheral surface 5 e of the outer peripheral piece portion 5 c in the antirust cover 5 of the present embodiment is projected as an engaging portion in the present invention over the entire circumference in the circumferential direction of the outer peripheral piece portion 5 c. A plurality of portions 5i are continuously formed in the tube axis C direction. Each of the protrusions 5i has a substantially arc shape in cross-sectional view, and is formed in a substantially wave shape in cross-sectional view by being formed in a plurality of strips continuously in the tube axis C direction.

  For this reason, the rust preventive cover 5 in the present embodiment is a state in which the rust preventive rubber 5a is brought into close contact with the pipe end surface 3b by engaging the protrusions 5i with the concave portions 3g of the engaged portions 3e. Thus, it can be held between the holding piece 5d and the pipe end surface 3b.

  Next, a pipe joint according to Example 3 will be described with reference to FIG. It should be noted that the same components as those shown in the above-described embodiment are denoted by the same reference numerals and redundant description is omitted. Hereinafter, the left side of FIG. 7 will be described as the front side (front side) of the antirust cover.

  As shown in FIG. 7, the inner peripheral surface 5e of the outer peripheral piece 5c of the rust preventive cover 5 of the present embodiment has a substantially arc-shaped engagement hole 5j over the entire periphery of the inner peripheral surface 5e. Are drilled at regular intervals. Further, these engagement holes 5j are formed at equal intervals along the tube axis C direction of the inner peripheral surface 5e.

  For this reason, a portion of the inner peripheral surface 5e where the engagement hole 5j is not drilled is configured as a protrusion 5k, and the protrusion 5k is engaged with the recess 3g of the engaged portion 3e. Thus, the rust preventive rubber 5a can be held between the holding piece 5d and the tube end surface 3b in a state of being in close contact with the tube end surface 3b. That is, in this embodiment, the engaging portion is configured by the engaging hole 5j and the protrusion 5k.

  Next, a pipe joint according to Example 4 will be described with reference to FIG. It should be noted that the same components as those shown in the above-described embodiment are denoted by the same reference numerals and redundant description is omitted. Hereinafter, the left side of FIG. 8 will be described as the front side (front side) of the antirust cover.

  As shown in FIG. 8, a hemispherical protrusion 5m as an engaging portion in the present invention is provided on the inner peripheral surface 5e of the outer peripheral piece 5c of the rust preventive cover 5 of this embodiment. It protrudes at equal intervals over the distance. Further, these protrusions 5m are provided so as to be spaced apart at equal intervals along the direction of the tube axis C of the inner peripheral surface 5e.

  For this reason, the rust preventive cover 5 of this embodiment is engaged with each other by engaging each protrusion 5m with the recessed portion 3g of the engaged portion 3e, thereby bringing the rust preventive rubber 5a into close contact with the pipe end surface 3b. In this state, it can be held between the holding piece 5d and the pipe end surface 3b.

  Next, a pipe joint according to Example 5 will be described with reference to FIG. It should be noted that the same components as those shown in the above-described embodiment are denoted by the same reference numerals and redundant description is omitted. Hereinafter, the left side of FIG. 9 will be described as the front side (front side) of the antirust cover.

  As shown in FIG. 9, the fluid pipe | tube 3 in a present Example is a ductile cast iron pipe manufactured by pouring ductile cast iron into a casting mold and then cooling. Although not shown, innumerable recesses are stamped on the inner surface of the mold for the ductile cast iron pipe in this embodiment over almost the entire surface so that the fluid pipe 3 can be easily detached from the mold after the casting of the fluid pipe 3. . For this reason, in the fluid pipe 3, the engaged portion 3e having a plurality of protrusions 3h is formed over substantially the entire circumference of the outer peripheral surface 3c when ductile cast iron is poured into the recess of the mold in the casting process. Is formed.

  For this reason, the rust preventive cover 5 of the present embodiment is concavo-convexly fitted by inserting the protrusions 5f and 5f as the engagement parts between the plurality of protrusions 3h and 3h as the engaged parts 3e, The rust preventive rubber 5a can be held between the holding piece portion 5d and the tube end surface 3b in a state of being in close contact with the tube end surface 3b.

  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.

  For example, in the above-described embodiment, the fluid pipes 2 and 3 are described as water pipes in which clean water flows, but the fluid flowing in the fluid pipes 2 and 3 is liquid other than water, such as petroleum, in addition to clean water. It may be a mixture of liquid and gas.

  Moreover, in the said Example, although the outer peripheral piece part 5c was formed cyclically | annularly over the perimeter of the guide ring 5b, several outer peripheral piece parts are formed along the circumferential direction of the outer diameter side edge part of the holding piece part 5d. You may do it.

  Moreover, in the said Example, although the guide ring 5b was comprised with the soft resin material etc. which have cyclic | annular elasticity by front view, the rust prevention rubber 5a is carried out by engaging the protrusion 5f with the to-be-engaged part 3e. The guide ring 5b may be a hard resin material, a non-corrosive metal material, or the like as long as it is possible to continue the rust prevention of the tube end surface 3b.

  Moreover, in the said Example, although the outer peripheral piece part 5c of the guide ring 5b was formed in the taper shape which diameter-reduces gradually toward the front side of the antirust cover 5, if the guide ring 5b is comprised with the soft resin material, it is. The outer peripheral piece 5c may be extended linearly toward the front side of the antirust cover 5.

  Moreover, in the said Example, although the elastic member demonstrated as the rust prevention rubber 5a comprised as butyl rubber which has a low impact resilience rate, it can contact | adhere to the pipe end surface 3b by changing with respect to the shape of the pipe end surface 3b. If so, the material of the elastic member may be a material other than butyl rubber.

  In the third embodiment, the engagement holes 5j are formed at equal intervals along the circumferential direction of the inner peripheral surface 5e of the outer peripheral piece 5c and the tube axis C direction of the inner peripheral surface 5e. In the fourth embodiment, the protrusions 5m are protruded at equal intervals along the circumferential direction of the inner peripheral surface 5e of the outer peripheral piece 5c and the tube axis C direction of the inner peripheral surface 5e. You may make it form 5j and the protrusion 5m at random over the whole inner peripheral surface 5e of the outer peripheral piece 5c.

DESCRIPTION OF SYMBOLS 1 Pipe joint 2 Fluid pipe 2a Receiving part 3 Fluid pipe 3a Insertion part 3b End face 3c Outer peripheral surface 3e Engagement part 3g Recessed part 3h Projection part 5 Rust prevention cover (rust prevention member)
5a Rust prevention rubber (elastic member)
5b Guide ring (holding part)
5c Outer peripheral piece (extension part)
5f Projection (engagement part)
5g, 5h Groove (adjustment part)
5i Projection (engagement part)
5j engagement hole (engagement part)
5k protrusion (engagement part)
5m protrusion (engagement part)

Claims (4)

An insertion opening formed at the distal end portion of one fluid pipe in the tube axis direction, a receiving portion formed at the distal end portion of the other fluid pipe in the tube axial direction, and the insertion portion An annular rust prevention member having an elastic member that rusts by pressing the tube end surface of the insertion portion by being inserted into the mouth portion, and having a holding portion that holds the elastic member with the tube end surface On the outer peripheral surface of the insertion portion, an engaged portion made of countless irregularities formed over the entire circumference by cooling the cast iron in the casting process of the fluid pipe and removing it from the mold. has, a pipe joint the spigot portion is connected in a watertight by being inserted into the socket portion,
The rust preventive member extends in a tapered shape that gradually decreases in diameter toward the insertion direction of the holding portion in the holding portion, and on the inner diameter direction side of the extending portion that is formed in an annular shape over the entire circumference. and the engaging portion is formed, the extension of the extended portion of the holding portion is fitted on the outer circumferential surface of the spigot portion, the elastic member by the holding portion in a state of being pressed toward the tube end face A pipe joint , wherein the engaging portion formed on the inner diameter direction side of the installation portion and the engaged portion on the outer peripheral surface of the insertion port portion are engaged with each other.   The pipe joint according to claim 1, wherein a plurality of the engaging portions are provided apart from each other in the pipe axis direction.   The holding portion and the elastic member include an adjusting portion that can adjust a protruding length of the one fluid pipe in the tube axis direction so as not to protrude from the inner diameter side end of the insertion port. The pipe joint according to claim 1 or 2, wherein   The pipe joint according to any one of claims 1 to 3, wherein the elastic member is made of a low resilience elastic material.

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