JP2011007205A - Separation preventing pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a separation preventing pipe joint preventing corrosion of a pipe or a locking tool by maintaining insulation between a press bolt, the locking tool and the pipe without causing damage to the outer surface of the locking tool when the press bolt is fastened to a housing.SOLUTION: A protective plate 38 engaged with the locking tool 34 and prevented from being rotated is put on the position of the locking tool 34, facing the tip of the press bolt 36, the locking tool having a pawl portion 34a bitten into the outer peripheral surface of a spigot 22.

Description

  The present invention relates to a detachment prevention pipe joint having a function of preventing detachment of joined pipes.

  Metal pipes such as ductile cast iron pipes that are used as underground water and sewage pipes are constructed by joining a plurality of pipes so that the pipes can move relatively within a certain range. As a result, the entire pipeline can be expanded and contracted against external forces such as earthquakes.

  There are the following methods for joining the tubes together. Preliminarily, an inlet with an expanded inner diameter is provided on one end of the tube, and an insertion port with an unextended outer diameter is provided on the other end. When joining two tubes, insert the inlet of one tube. What is necessary is just to insert in the receptacle of the other pipe | tube.

  In this method, when the joined pipes are moved away from each other by external force (water pressure due to water flow into the pipe, etc.), the joined part of the pipe is not released and released. Is provided with a function for preventing separation.

  Here, when the pipe itself is not provided with a detachment prevention function, there is a method of providing a detachment prevention function as described in Patent Document 1. FIG. 7 shows the configuration of such a pipe joint in the prior art.

In FIG. 7, one tube 1 has a receiving port 51, and a flange portion 54 having an outer diameter larger than that of the receiving port back side is provided on the outer periphery of the opening end of the receiving port 51.
The other tube 2 has an insertion port 52, and this insertion port 52 is inserted into the receiving port 51, and is made of an elastic material between the inner peripheral surface of the receiving port 51 and the outer peripheral surface of the insertion port 52. The annular seal member 60 (rubber ring or the like) is compressed and fitted, and the elasticity closes the gap between the inner peripheral surface of the receiving port 51 and the outer peripheral surface of the insertion port 52.

  The housing 53 is externally fitted from a position facing the outer surface of the insertion opening 52 outside the receiving port 51 to a position facing the outer surface of the receiving port 51 on the deeper side of the receiving port than the flange 54.

On the back side of the receiving port 51 of the housing 53 (on the right side in FIG. 7), a flange portion 55 is provided to face the flange portion 54.
The inner diameter of the flange portion 55 is larger than that of the flange portion 54, and a lock ring 58 that is divided into an appropriate number in the circumferential direction (for example, divided by one) is disposed between the flange portion 55 and the flange portion 54. It is installed. The outer diameter of the lock ring 58 is formed so as to be larger than the outer diameter of the flange portion 54 when the lock ring 58 is disposed on the outer peripheral surface of the receiving port 51 on the back side of the receiving port 51 with respect to the flange portion 54. Has been.

  Then, the tip of a set bolt 59 provided at an appropriate position in the circumferential direction (for example, at four equal pitches) and screwed inwardly in the pipe radial direction from the outer surface of the housing 53 comes into contact with the outer peripheral surface of the lock ring 58. The lock ring 58 is fitted on the outer peripheral surface of the receiving port 51 on the back side of the receiving port 51 with respect to the flange portion 54.

  On the other hand, the inner surface of the housing 53 is tapered so that the inner diameter increases from the insertion port 52 side toward the opening end of the receiving port 51 at a position facing the outer surface of the insertion port 52. A plurality of locking tools 56 are disposed between the outer peripheral surface of the insertion port 52 and the inner peripheral surface of the housing 53 at a predetermined interval in the tube circumferential direction of the insertion port 52.

  A claw portion 56 a that can bite into the outer peripheral surface of the insertion opening 52 is provided on the inner peripheral surface side of the locking tool 56, and the outer peripheral surface side of the locking tool 56 is the tapered inner surface of the housing 53. It becomes the taper surface of the shape along.

  The tip of the push bolt 57 screwed from the outer peripheral side of the housing 53 toward the tapered outer peripheral surface of the locking member 56 (that is, at an angle inclined with respect to the outer peripheral surface of the insertion port 52) The stopper 56 is pressed against the outer peripheral surface of the insertion opening 52 by contacting the outer peripheral surface of the taper.

  With such a configuration, when an external force (detachment force) is applied to extract the insertion port 52 from the receiving port 51, the insertion port 52 attempts to move away from the receiving port 51. As the insertion port 52 moves, the locking member 56 moves to the smaller diameter side of the tapered surface of the inner peripheral surface of the housing 53 on the insertion port 52 side, so that the locking member 56 protrudes from the inner peripheral surface of the housing 53 by the wedge action. The front end surface of the push bolt 57 is pressed strongly toward the outer peripheral surface of the insertion port 52, and the claw portion 56 a bites into the outer peripheral surface of the insertion port 52. As a result, the detachment force applied to the insertion opening 52 is transmitted to the housing 53.

  Since the receiving port 51 side of the housing 53 is engaged with the flange portion 54 of the receiving port 51 via the flange portion 55 and the lock ring 58, the detachment force is transmitted from the insertion port 52 to the locking tool 56 and the housing 53. , It is transmitted to the receiving port 51 side through the lock ring 58, and the insertion port 52 and the receiving port 51 do not move in a direction away from each other, and the insertion port 52 may be detached from the receiving port 51. Is prevented.

Japanese Utility Model Publication No. 60-161774

  Incidentally, the push bolt 57, the locking tool 56 and the pipe are often made of ductile cast iron, but the push bolt 57 is used as a pipe joint for joining pipes embedded in the ground. In some cases, in order to prevent corrosion due to exposure to groundwater or the like, it may be made of stainless steel having high corrosion resistance. When the push bolt 57 is made of stainless steel, the push bolt 57, the locking tool 56, and the pipe are made of different kinds of metals. Since the push bolt 57, the locking tool 56, and the pipe are electrically connected to each other by dissimilar metals, corrosion of the locking tool 56 and the pipe is promoted by the sacrificial anode effect.

  Therefore, in order to prevent corrosion from being promoted even if the pressing bolt 57 and the locking tool 56 come into contact with each other, an insulating film is applied to the outer peripheral side surface of the locking tool 56 (the surface contacting the tip of the pressing bolt 57). There is a way. If an insulating film is painted on the outer peripheral surface of the locking tool 56, the pressing bolt 57 and the locking tool 56 are insulated even if the tip of the pressing bolt 57 is in contact with the outer peripheral surface of the locking tool 56. Therefore, the corrosion of the locking tool 56 and the pipe is prevented from being promoted by the sacrificial anode effect due to the contact between different metals.

  However, in the prior art as described in Patent Document 1, in order to securely bite the claw portion 56a on the inner periphery of the locking tool 56 into the outer peripheral surface of the insertion opening 52, the push bolt 57 is tightened from the outer peripheral side of the tube. Therefore, it is necessary to press the outer peripheral surface of the locking tool 56 toward the insertion port 52 side (inner side in the pipe diameter direction) with the tip of the push bolt 57. At this time, since the tip of the push bolt 57 contacts and rotates with the outer peripheral surface of the locking tool 56, when tightened with a strong torque, the portion of the outer peripheral surface of the locking tool 56 that contacts the tip of the pressing bolt 57 is damaged. And the insulating film painted on the locking member 56 at that portion is peeled off.

  When the insulation film of the locking tool 56 is peeled off by tightening the push bolt 57, the push bolt 57, the locking tool 56, and the pipe are in a state of being electrically connected to each other by different metals, and the locking tool is caused by the sacrificial anode effect. Corrosion of the 56 and the pipe is promoted, and the corrosion of the locking member 56 and the pipe progresses rapidly.

  In view of the above problems, the present invention does not damage the outer surface of the locking tool when the pressing bolt is tightened, and the insulation between the pressing bolt, the locking tool, and the tube is maintained. An object of the present invention is to provide a disconnection prevention pipe joint that prevents corrosion of the steel.

  In order to solve the above-mentioned problem, the separation preventing pipe joint of the present invention has one tube provided with a receiving port and the other tube provided with an insertion port inserted into the receiving port of the one tube. A housing that is externally fitted from a position facing the insertion outer surface on the outside of the receiving port to a position facing the receiving outer surface is joined to the receiving port; Between the peripheral surface and the outer peripheral surface of the insertion port, a locking tool having a claw part that can bite into the outer peripheral surface of the insertion port and having an insulating film coated on the outer peripheral surface is disposed, A push bolt hole into which a push bolt can be screwed is formed at a position facing the lock in the housing, and the lock is screwed into the push bolt hole and screwed in from the outer peripheral side of the pipe of the housing. It has a push bolt that can be pressed toward the outer peripheral surface of the insertion opening, And a protective plate to a position facing the pressing bolt tip is covered.

  And a pipe joint having one tube provided with a receiving port and the other tube provided with an insertion port inserted into the receiving port of the one tube, and an inner peripheral surface of the receiving port. Between the outer peripheral surface of the insertion port, a locking tool having a claw part that can bite into the outer peripheral surface of the insertion port and having an insulating film coated on the outer peripheral side surface is disposed. A push bolt hole into which a push bolt can be screwed is formed at a position facing the locking tool, and the locking tool is inserted into the push bolt hole by being screwed from the outer peripheral side of the receiving port. A push bolt that can be pressed toward the outer peripheral surface side is provided, and a protective plate is covered at a position facing the tip end of the push bolt of the locking tool.

If comprised in this way, when a push bolt is tightened and a latching tool is pressed, since the protective plate is attached to the latching tool, a latching tool and a push bolt will not contact directly.
Further, it is desirable that the protective plate is provided with a rotation stopper that prevents the protective plate from rotating with respect to the locking tool when the push bolt is tightened by engaging with the locking tool.

  If comprised in this way, the pressing force at the time of clamping | tightening a push bolt can be transmitted to a locking tool, preventing that a protection board rotates with respect to a locking tool by rotation of a push bolt.

  According to the separation preventing metal fitting of the present invention, the locking tool and the push bolt are not in direct contact with each other, so that the outer surface of the locking tool is not damaged by the tip of the push bolt when the push bolt is tightened. Since there is no possibility that the insulating film is peeled off, the insulation between the push bolt, the locking tool, and the pipe is maintained, and corrosion of the locking tool and the pipe is prevented.

  Also, if the protective plate is prevented from rotating and the protective plate is prevented from rotating with respect to the locking tool by the rotation of the push bolt, the surface of the locking tool may be damaged by the rotation of the protective plate. Can be prevented.

  Moreover, since the protective plate is prevented from being detached from the locking tool by engaging the protective plate with the locking tool, workability when the protective plate is attached to the locking tool is improved. .

Sectional drawing which shows the structure of the fastener periphery in the separation prevention pipe joint of embodiment of this invention (A) is a top view which shows the locking tool used for the said separation prevention pipe joint, (b) is a front view which shows the locking tool, (c) is sectional drawing which shows the locking tool (A) is a top view which shows the protection plate covered on the locking tool, (b) is a front view which shows the protection plate, (c) is an end view which shows the protection plate The perspective view which shows the protective plate used for the said separation prevention pipe joint Sectional drawing which shows another example of the locking tool used for the said separation prevention pipe joint Sectional drawing which shows the structure of the locking tool periphery in the separation prevention pipe joint which concerns on another example of embodiment of this invention. Sectional view showing the structure of a conventional anti-separation fitting

Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.
First, the structure around the locking member of the separation preventing pipe joint according to the present embodiment will be described with reference to FIG.

  Similarly to the pipe joint of the prior art, also in the present embodiment, the insertion port 22 of the other tube is inserted into the reception port (not shown) of one tube, and the housing 3 extends between the reception port and the insertion port 22. It is fitted.

  Here, although illustration is omitted, the housing 3 is externally fitted from the position facing the outer surface of the insertion opening 22 on the outer side of the receiving port to the position facing the outer surface of the receiving port. It is joined to the mouth.

  The inner peripheral surface of the housing 3 is tapered so that the inner diameter increases from the insertion port 22 side toward the receiving port opening end, and between the inner peripheral surface of the housing 3 and the outer peripheral surface of the insertion port 22. Is provided with claw portions 35a, 35b that can bite into the outer peripheral surface of the insertion opening 22 and having an insulating film coated on the outer peripheral surface thereof. A plurality of the locking tools 34 are arranged at predetermined intervals in the tube circumferential direction of the insertion opening 22.

A push bolt hole 32 is formed at a position facing the outer surface of the insertion opening 22 of the housing 3, and the push bolt hole 32 can be screwed into the push bolt 36.
The push bolt 36 is screwed into the push bolt hole 32 and screwed at an angle inclined from the outer peripheral side of the housing 3 to the outer peripheral surface of the insertion opening 22 (an angle such that the tip advances toward the back of the receiving end as the screw is inserted). The front end surface of the bolt 36 is brought into contact with the tapered surface of the outer peripheral surface of the locking tool 34 disposed between the inner peripheral surface of the housing 3 and the outer peripheral surface of the insertion port 22, and the locking tool 34 is inserted into the insertion port 22. It can be pushed to the side.

Here, as shown in FIG. 1, in the present invention, a protection plate 38 is placed at a position facing the tip of the push bolt 36 of the locking tool 34.
FIG. 2 shows the detailed shape of the locking member 34 covered with the protective plate 38 as a single unit. The locking tool 34 has a central portion 30 and both side portions 31a and 31b. As shown in a plan view in FIG. 2 (a) and a front view in FIG. 2 (b), the central portion 30 has both side portions 31a. , 31b, and the outer peripheral surface 34c side (the upper side in FIG. 2B) of the central portion 30 is a portion that receives the pressing force of the pressing bolt 36. Further, as shown in FIG. 2 (a), the both side portions 31a and 31b are configured such that the distal end side along the circumferential direction of the tube (the left-right direction on the paper surface in FIG. 2 (a)) is tapered in plan view. Is formed. Moreover, as shown in FIG.2 (c), the outer peripheral surface 34c side of the center part 30 is a taper surface.

  Then, the inner peripheral surface 34d side (the lower side in FIG. 2B) of the locking tool 34 has an arcuate shape along the outer peripheral surface of the insertion slot 22, and is shown in FIG. As shown in the cross-sectional view, projecting claw portions 35a and 35b are provided at both ends of the inner peripheral surface 34d in the axial direction (left and right direction in FIG. 2C). In FIG. 2C, the sizes of the claw portions 35a and 35b are emphasized to represent the shapes of the claw portions 35a and 35b.

  As shown in FIG. 2A, the claw portion 35a on the front side (the lower side in FIG. 2A) is formed only in the central portion 30, and the circumferential direction of the central portion 30 (FIG. 2A). ) In the horizontal direction of the paper surface). On the other hand, the claw portion 35b on the rear side (the upper side in FIG. 2A) is formed not only on the central portion 30 but also on both side portions 31a and 31b, and extends over the entire circumferential length of the locking device 34. Yes.

  Next, FIG. 3 shows a state of the protection plate 38 in a state of being covered with the locking tool 34. As shown in the plan view of FIG. 3 (a) and the front view of FIG. 3 (b), the protective plate 38 is on the outer peripheral surface 34c side of the central portion 30 of the locking device 34 (the side opposite to the claw portions 35a and 35b). It is put on. As shown in FIG. 1, the protective plate 38 has a center that faces the tip of the push bolt 36 when the locking tool 34 is attached to the insertion opening 22 and the push bolt 36 is screwed into the push bolt hole 32. Since it is only necessary to cover the portion 30, it is not necessary to cover the entire length of the locking tool 34 in the circumferential direction (left and right direction in FIG. 3A) as shown in FIG.

  A perspective view of the protection plate 38 is shown in FIG. The protective plate 38 can be manufactured by press-molding a metal such as stainless steel, and has a shape in which a single plate is bent at two locations. In the present embodiment, a protection plate 38 shown in FIG. 4 is formed by bending a flat metal plate at two locations. Here, in the protection plate 38 shown in FIG. 4, a protection plate front portion 38 a and a protection plate rear portion 38 b are formed at both ends of the protection plate central portion 38 c that covers the outer peripheral surface 34 c of the locking tool 34.

  Here, when bending, as shown in the end view of FIG. 3C, the protective plate central portion 38c between the protective plate front portion 38a and the protective plate rear portion 38b is formed at the central portion of the locking tool 34. It is preferable that the protective plate front portion 38a and the protective plate rear portion 38b be angled along the side surfaces 34a and 34b of the locking member 34 so as to be along the outer peripheral surface 34c side tapered surface of 30.

  When the protection plate 38 is put on the locking member 34 so that the protection plate central portion 38c covers the central portion 30 of the locking device 34, the protection plate front portion 38a is engaged as shown in FIG. A protective plate rear portion 38b is along a side surface 34b on the front side (left side in FIG. 3C) of the stopper 34, and a rear side 38b of the protective plate 34 is on the rear side (right side in FIG. 3C). Each is arranged, and the protection plate 38 is engaged with the locking tool 34.

  In this way, when the protective plate 38 is formed so as to be engageable with the locking tool 34 by bending a single metal plate or the like, the protective plate 38 is covered when the protective plate 38 is put on the locking tool 34. 38 does not slide along the outer peripheral surface 34c side taper surface of the central portion 30 of the locking tool 34. Therefore, when the protective plate 34 is attached (covered) to the locking tool 38 in a factory or the like, the locking tool Since the attaching work can be performed without the risk of the protective plate 34 falling off from 38, workability is improved.

  In this way, the protective plate 38 is covered on the outer peripheral surface of the locking device 34, and the protective plate front portion 38 a and the protective plate rear portion 38 b are along the side surfaces 34 a and 34 b of the locking device 34. When the push bolt 36 is tightened from the outer periphery side of the pipe as shown in FIG. 1 in the state where the push bolt 36 is engaged, the inward force in the pipe radial direction caused by the tightening of the push bolt 36 is engaged via the protective plate 38. It is transmitted to the stopper 34 and acts to press the locking tool 34 toward the outer peripheral surface of the insertion opening 22.

  In this state, when an external force (withdrawal force) is applied to extract the insertion port 22 from the receiving port, the locking tool 34 moves into the insertion port 22 side of the housing 3 as the insertion port 22 moves in the removal direction. It moves to the small-diameter side of the taper surface of the peripheral surface, the locking tool 34 is strongly pressed toward the outer peripheral surface of the insertion port 22, and the claw portions 35 a and 35 b bite into the outer peripheral surface of the insertion port 22. Become. As a result, the detaching force applied to the insertion port 22 is transmitted to the receiving side joined to the housing via the locking member 34 and the housing 3, and the insertion port 22 is released from the receiving port. It is prevented.

  When such a protection plate 38 is put on the locking tool 34, the tip of the push bolt 36 does not directly contact the outer peripheral surface of the locking tool 34. The outer peripheral surface is prevented from being damaged. For this reason, in the locking tool 34 to which the protection plate 38 is attached, the coating such as an insulating film applied to the locking tool 34 is peeled off when the pressing bolt 36 is tightened, and the pressing bolt 36 and the locking tool 34 are removed. In addition, there is no risk of electrical connection with the pipe.

  On the other hand, the force that is applied to the push bolt 36 when the push bolt 36 is tightened is transmitted to the protective plate 38 that contacts the tip of the push bolt 36, and the protective plate 38 is pushed by the push bolt. It tries to rotate in the same direction as the rotation direction of 36. However, the protection plate front portion 38a and the protection plate rear portion 38b of the protection plate 38 are along the front and rear side surfaces 34a and 34b of the locking device 34, respectively, so that the protection plate 38 is engaged with the locking device 34. Therefore, the force to rotate is only transmitted to the locking tool 34 through the protection plate front part 38a and the protection plate rear part 38b, and the protection plate 38 does not rotate with respect to the locking tool 34.

  As described above, since the protection plate 38 is engaged with the locking device 34 by the protection plate front portion 38a and the protection plate rear portion 38b, the rotation stop is prevented from rotating with respect to the locking device 34. Further, there is no possibility that the protection plate 38 rotates on the surface of the locking tool 34 according to the rotation of the push bolt 36 and damages the surface of the locking tool 34.

  As a confirmation test, a protective plate made of stainless steel with a thickness of 0.5 mm was actually attached to a locking tool with a nominal diameter of 75 mm and tightened with a tightening torque of 120 N · m toward the locking tool. Although there was a trace of the push bolt on the portion where the force was applied from the push bolt, the portion where the force was applied from the push bolt in the locking tool was not marked, and the coating (insulating film, etc.) was not damaged.

  In this way, in the detachment prevention pipe joint using the locking tool to which the protective plate as in the present invention is attached, the insulating coating coated on the locking tool is not damaged when the push bolt is tightened. The insulation between the push bolt and the locking tool and the tube is maintained. Therefore, the sacrificial anode effect does not promote corrosion of the locking tool and the tube, and corrosion of the claw portion of the locking tool and the tube is prevented.

  In addition, as a locking tool, you may use the locking tool 44 of a shape as shown in FIG. As in the above-described embodiment, the locking member 44 is disposed between the inner peripheral surface at a position facing the insertion port of the housing joined to the receiving port and the outer peripheral surface of the insertion port 22, and has a claw portion. Only one 44a is provided at the axially central portion on the inner peripheral surface side of the locking tool 44, and the portion facing the tip of the push bolt 36 on the outer peripheral surface side is curved in a convex shape in the upward direction on the paper surface. . In addition, an insulating film is coated on the surface on the outer peripheral surface side.

  When such a locking tool 44 is used, when a detachment force is applied to detach the insertion slot 22 from the receiving port, the claw portion 44a on the inner peripheral surface side of the locking tool 44 moves away from the receiving port. Thus, the locking tool 44 swings and the claw portion 44a bites into the outer peripheral surface of the insertion slot 22, so that the detachment force is transmitted from the insertion slot 22 to the receiving slot through the locking tool 44 and the housing. Thus, the insertion opening 22 is prevented from being detached from the receiving opening.

  Even with the locking tool 44 having such a shape, by covering the portion facing the tip of the push bolt 36 on the outer peripheral surface side of the lock tool 44, the lock tool due to the rotation of the push bolt 36. The peeling of the coating on the outer peripheral surface 44 can be prevented.

  In addition, when a protective plate is put on a locking tool having a curved outer peripheral surface like the locking tool 44, the outer periphery of the locking tool 44 in the protective plate 38 is shown in FIG. A portion covering the surface may be curved along the outer surface of the locking tool 44. Thus, when the protection plate 38 having a curved shape along the outer surface of the locking tool 44 is put on the locking tool 44, the curved surface of the protection plate 38 is engaged with the locking tool 44. Function as.

  In addition, as another example of the structure of the separation preventing pipe joint of the present invention, a configuration as shown in FIG. 6 can be used. In the configuration shown in FIG. 6, the insertion port 72 is inserted into the receiving port 71, and an annular sealing material 79 made of an elastic material is fitted between the inner peripheral surface of the receiving port 71 and the outer peripheral surface of the insertion port 72. This is the same as the configuration of the prior art as shown in FIG. However, the method shown in FIG. 6 does not use a housing as shown in FIGS. 1 and 7, and a groove 73 is provided on the inner surface of the receiving port 71 in which a locking tool 76 can be placed. By disposing the locking tool 76, the locking tool 76 having a claw portion 76 a that can bite into the outer peripheral surface of the insertion port 72 between the inner peripheral surface of the receiving port 71 and the outer peripheral surface of the insertion port 72. It is in a state of being arranged. In addition, an insulating film is coated on the outer peripheral side surface of the locking member 76.

  In the separation preventing pipe joint of FIG. 6, the locking tool 76 can be pressed toward the insertion port 72 by the tip of the pressing bolt 77 by screwing the pressing bolt 77 from the outer peripheral side of the receiving port. It has become.

  Here, at the position facing the front end of the push bolt 77 of the locking tool 76, a protective plate 78 with a rotation stop similar to the protective plate 38 shown in FIGS. 3 and 4 is covered. Damage to the paint on the surface of the locking member 76 due to the rotation of the bolt 77 is prevented.

  In this state, by tightening the push bolt 77 from the outer peripheral side of the receiving port 71 and pressing the locking member 76 against the outer peripheral surface of the insertion port 72, the insertion port is the same as the separation preventing pipe joint having the structure shown in FIG. 72 can be prevented from leaving the receiving port 71.

  In this embodiment, stainless steel is used as the protective plate. However, the protective plate is made of a material that does not rust even if it is buried in the ground and exposed to groundwater, and can withstand the pressure of the push bolt. Any material that has

3 Housing 12 Receiving Port 22 Inserting Port 34 Locking Tool 36 Push Bolt 38 Protection Plate

Claims (3)

A pipe joint having one pipe provided with a receiving port and the other pipe provided with an insertion port inserted into the receiving port of the one pipe,
A housing that is externally fitted to a position facing the outer surface of the receiving port from a position facing the outer surface of the insertion port on the outside of the receiving port is joined to the receiving port,
Between the inner peripheral surface of the housing and the outer peripheral surface of the insertion port, a locking tool having a claw portion that can bite into the outer peripheral surface of the insertion port and having an insulating film coated on the outer peripheral surface is disposed. And
A push bolt hole capable of screwing a push bolt is formed at a position facing the locking tool in the housing,
A push bolt that can be screwed into the push bolt hole and screwed from the outer peripheral side of the tube of the housing to press the locking tool toward the outer peripheral surface of the insertion port;
A disengagement prevention pipe joint, wherein a protection plate is put on a position facing the tip of the push bolt of the locking tool. A pipe joint having one pipe provided with a receiving port and the other pipe provided with an insertion port inserted into the receiving port of the one pipe,
Between the inner peripheral surface of the receiving port and the outer peripheral surface of the insertion port, a locking tool having a claw portion that can bite into the outer peripheral surface of the insertion port and having an insulating film coated on the outer peripheral surface is disposed. Has been
A push bolt hole in which a push bolt can be screwed is formed at a position facing the locking tool in the receiving port,
A push bolt that can be screwed into the push bolt hole and screwed in from the outer peripheral side of the pipe of the receiving port to press the locking tool toward the outer peripheral surface of the insertion port;
A disengagement prevention pipe joint, wherein a protection plate is put on a position facing the tip of the push bolt of the locking tool.   3. The protection plate according to claim 1, wherein a rotation stop is provided on the protection plate so that the protection plate does not rotate with respect to the locking tool when the push bolt is tightened by engaging with the locking tool. Detachment prevention pipe joint in any one.

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