JP2005282684A - Earthquake resistant pipe fitting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an earthquake resistant pipe fitting with a socket outside portion 2b having improved breaking strength and flexibility. <P>SOLUTION: One splitting tight lock ring 13 is movably fitted into an annular groove 15 of a spigot 1 and a lock ball 11 is provided in an annular groove 12 of the socket 2, and the lock ball and the lock ring abut with each other at their circular faces. In this way, two lock members exist where the lock ball has a sufficient diameter to abut on the lock ring and the groove storing the lock ball has a sufficient depth to make the spigot pass when storing it and to absorb the larger diameter of the lock ring. Thus, the socket side lock member storage groove can be shallower than that of a PII type fitting, and so the pipe thickness of the socket in its groove area can be thicker, thereby achieving higher breaking strength. When the spigot is bent in the socket, its abutting point is moved along the circular face of the lock ball to allow the bending, therefore achieving smooth bending. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an earthquake-resistant pipe joint and a method for connecting the pipe joint when constructing a pipe for transporting fluid used in waterworks, gas, sewers and the like.

  When constructing a pipe for fluid transportation with ductile cast iron pipe, etc., the pipe joint part is constructed by inserting the insertion port of one pipe into the receiving port of another pipe via a rubber ring, and into the receiving port. There are PII-type, S-type, NS-type, SII-type, etc. as joints that have an earthquake-resistant structure in which the insertion port can be expanded and contracted within a required range (can be inserted and removed).

The seismic pipe joint is usually one in which the insertion port is movable in the axial direction with respect to the receiving port. For example, a PII type joint receives a pipe P as shown in FIG. After the rubber ring 6 for sealing is inserted in the inner side of the mouth 2 and the lock ring 3 is loaded on the outer side, the insertion port 1 is expanded in diameter of the lock ring 3 and is stored in the storage groove 7 of the receiving port 2. 6 is inserted while being compressed, and when the lock ring 3 reaches the annular groove 5 on the outer peripheral surface of the insertion opening, set bolts 4 are screwed into the receiving opening 2 from several places around the receiving opening 2 to reduce the diameter of the lock ring 3 and thereby reduce the groove 5. (See Patent Document 1).
Japanese Utility Model Publication No. 54-24326

  On the other hand, as a method of embedding fluid transport pipes such as ductile cast iron pipes, the open-cut method of excavating and laying the ground was common, but recently the traffic volume has increased not only on main roads but also on general roads Therefore, it is difficult to block traffic due to the open-cut method. For this reason, only the starting and reaching shafts are excavated, and a fume pipe or steel pipe is pushed and buried as a sheath pipe (sheath pipe), then a ductile cast iron pipe is inserted, or an existing pipe is used as a sheath pipe. A propulsion method such as a pipe-in-pipe method, in which a new pipe with a small diameter is inserted to renew the pipe line, has come to be widely adopted.

  In the pipe-in-pipe method, as shown in FIG. 11, a new pipe P having a smaller diameter is inserted and laid in an existing pipe P ′ buried between the start pit S and the arrival pit R. In the starting pit S, a hydraulic jack J is installed, the rear portion of the hydraulic jack J abuts against the reaction force receiver H, and the front portion presses the new pipe P via the push angle B. The new pipe P is sequentially joined by inserting the insertion port 1 at the tip end thereof into the receiving port 2 at the rear end part of the preceding new pipe P, and is pushed into the existing pipe P ′. A leading sled K for reducing insertion resistance is attached to the tip of the leading new pipe P.

  At this time, when the PII type joint is used as a new pipe P, in order to secure a large distribution area by using one having a nominal diameter smaller than the diameter of the sheath pipe P ′, The outer diameters of the insertion port 1 and the receiving port 2 are smaller than those of the insertion port 1 and the receiving port 2 (thicknesses of the insertion port 1 and the receiving port 2 are reduced).

Since the PII type joint expands the diameter of the lock ring 3 and inserts the insertion port 1 into the receiving port 2, the storage groove 7 of the lock ring 3 needs to have a depth capable of absorbing the expanded diameter. For this reason, the tube thickness of the receiving port 2 of the annular groove 5 is reduced, and a pulling force acts on the insertion port 1 as shown in FIG. 10, and the pulling force acts on the receiving port 2 by the lock ring 3. Then, force acts on the outer portion 2b of the lock ring groove (storage groove) 7 as indicated by an arrow, and the outer portion 2b may be damaged.
Incidentally, the PII type joint has only a 1/2 insertion opening removal preventing force from the point that the outer portion 2b is easily damaged compared to the joint having the highest level of earthquake resistance such as the NS type joint.

  In addition, since the lock ring 3 is fixed with the set bolt 4 in the PII type joint, it is difficult to construct it when the pipe is bent greatly, and excessive stress may be generated if the joint is bent forcibly. There is.

  An object of the present invention is to increase the breaking strength of the outer portion 2b of the receiving opening and improve the flexibility.

  In order to achieve the above object, according to the present invention, first, a locking member is provided on both the insertion port side and the receiving port side, and the pulling force is transmitted from the insertion port to the receiving port via both locking members. It was.

In this case, the lock member on the receiving side only needs to have a thickness with which the lock member on the insertion port side comes into contact, and the groove for storing the lock member on the receiving side stores the lock member. What is necessary is just to have the depth which can absorb the expansion diameter of the insertion port side locking member at the time of the insertion, and the depth which an insertion port can pass in the accommodation state.
For this reason, the receiving-side annular groove (lock ring housing groove 7) can be made shallower than the PII type joint, and thereby the tube thickness of the receiving port of the groove portion can be increased. If it is thicker, the breaking strength becomes higher.

  Next, according to the present invention, the lock member on the receiving side is constituted by a lock ball. When the surface of the lock ball is an arc surface, and the receiving side locking surface is an arc surface, the lock ring on the insertion port side comes into contact with the arc surface. Since the contact point with the lock ring moves along the arc surface to allow the bending, the bending is performed smoothly.

  As described above, according to the present invention, since the lock member is provided on both the inlet side and the receiving side and the receiving side locking member is a lock ball, the breaking strength of the outer portion of the receiving port is increased and the flexibility is increased. It can be an improved earthquake resistant pipe joint.

Best Mode for Carrying Out the Invention

  As an embodiment of the present invention, an insertion port of one tube is inserted into a receiving port of another tube via a rubber ring, and a required width in the tube axis direction is provided around the outer periphery of the distal end portion of the insertion port. An annular groove is formed, and a lock ring with one split screw is fitted into the annular groove so as to be movable in the width direction, and the insertion opening is inserted into the reception opening on the entire inner surface of the reception opening. An annular groove is formed to allow the lock ring to expand when inserted, and a lock ball is fitted into the annular groove, and the lock ring fitted into the insertion-portion-side annular groove is inserted into the lock ball. It is possible to employ a configuration that locks in the pulling direction.

  In this configuration, movement of the lock ring within the width of the annular groove on the insertion port side allows expansion and contraction of the insertion port with respect to the reception port, and the lock ring engages with the lock ball so that the insertion port is pulled out from the reception port. The tip of the insertion port is in contact with the inner end surface of the receiving side annular groove while the tip of the insertion port is in contact with the inner end surface of the receiving side annular groove. Further insertion (pushing) of the insertion opening is prevented.

The lock ball can be fitted into the receiving-side annular groove by any means before the insertion port is inserted into the receiving port. A hole that leads to the mouth-side annular groove is formed, and a lock ball is fitted into each hole and protrudes into the mouth-side annular groove. The ring is locked in the direction of pulling out the insertion opening, and the holes are plugged to prevent the lock ball from coming out, and the lock ball is not locked with the lock ring. Can be adopted.
In this way, if the lock ball can be set after inserting the insertion port into the receiving port, the lock member (lock ball) on the receiving side when the insertion port is inserted into the inner surface of the receiving port. Since there is no need to consider the protrusion, the annular groove on the receiving port side only needs to have a depth for accommodating the lock member on the insertion port side when the diameter thereof is expanded, and the depth can be made shallower.

In these configurations, a circumferential groove in the circumferential direction of the receiving-side annular groove can be formed from each of the holes, and the lock ball can be inserted into the groove so that the lock ring is not released.
In this way, if the circumferential groove is formed, the circumferential groove can store the lock ball when inserted into the insertion port, and the circumferential groove is partially compared to the annular groove. Therefore, compared with the case where the lock ball is stored in the annular groove when the insertion port is inserted into the receiving port, the outer portion of the receiving port has a higher breaking strength.

  Further, if the wall surface of the hole or circumferential groove that is in contact with the lock ball in the insertion direction of the insertion port is the same curvature surface as that of the lock ball, the pulling force through the lock ball from the lock ring is the curvature surface (arc Surface) is transmitted to the receiving port over the entire area, there is no stress concentration, and the outer portion of the receiving port is difficult to break due to the pulling force.

  Furthermore, if the abutment surface of the lock ring with the lock ball is an inclined surface or a vertical surface facing the axis of the tube in the direction of pulling out the insertion port, the tube axis of the insertion port and the receiving port may be misaligned or inserted. If there is a manufacturing tolerance between the outer surface of the mouth and the inner surface of the receiving port, the deviation or tolerance is absorbed by the deviation (movement) of the both contact surfaces in the contact surface direction.

  These earthquake-resistant pipe joints can be conceived in various connection methods. For example, a rubber ring and a lock ring are loaded in the receiving port of one tube, and the diameter of the lock ring is not expanded in the insertion port of the other tube. It is possible to adopt a method of inserting and fitting the lock ring into the insertion-portion-side annular groove, and then inserting a lock ball from the hole to engage with the lock ring.

  At that time, the insertion port can be inserted in a state in which a diameter expanding tool is inserted from the end face opening of the receiving port and the lock ring is expanded in diameter by the diameter expanding tool.

FIG. 1 to FIG. 7 show an embodiment. In this embodiment, one pipe P made of a ductile cast iron pipe is inserted into the receiving port 2 of another pipe P with a rubber ring 6 interposed. The grooves 12 and 15 having the required widths t ₁ and t ₂ are respectively formed in the tube axis direction on the entire inner periphery of the receiving port 2 and the entire outer periphery of the distal end of the insertion port 1. (Refer to FIG. 6 (a)), the lock ball 11 is fitted in the receiving side groove 12, and the lock ring 13 is fitted between the grooves 12, 15 so as to be movable in the tube axis direction.

  The receiving-side annular groove 12 has a depth allowing the diameter of the lock ring 13 to be expanded when the insertion port 1 is inserted into the reception port 2. A hole 14 is formed in the circumferential direction of the receiving-side annular groove 12 from each hole 14, and the lock ball 11 enters the groove 16 to receive the hole. It protrudes into the mouth-side annular groove 12. A screw plug 17 is screwed into each hole 14 to prevent the lock ball 11 from coming out. The number of the holes 14 and the length of the circumferential groove 16 are arbitrary. In the drawing, 18 is a guide groove formed on the inner surface of the receiving port 2 extending from the end surface of the receiving port 2 to the groove 12.

  The outer wall surface 16a of the circumferential groove 16 has the same curvature surface as that of the lock ball 11, and the pulling force through the lock ball 11 from the lock ring 13 is received by the entire curvature surface (arc surface) 16a. 2, there is no stress concentration, and the receiving-portion outer portion 2 b is hardly broken by the pulling force.

  The lock ring 13 has a circular shape lacking a part 13b shown in FIG. 3 and is made of the same material as the conventional lock ring 3 such as FCD, SS, etc. The distal end of the insertion opening 1 can pass through while being expanded and fit into the groove 15. In order to facilitate the spreading, the entire outer periphery of the tip of the insertion opening is a downwardly inclined taper surface 1a. The lock ball 11 is also made of the same material as the conventional lock ring 3 such as FCD or SS (see FIG. 2A).

A contact surface 13 a of the lock ring 13 with the lock ball 11 is an inclined surface directed toward the axis c (see FIG. 7) of the tube P in the direction of pulling out the insertion port 1, and the tube of the insertion port 1 and the receiving port 2. If the axis c is displaced or if there is a manufacturing tolerance between the outer surface of the insertion slot 1 and the inner surface of the receptacle 2, the deviation or tolerance is absorbed by the displacement (movement) of the contact surfaces 13a in the contact surface direction.
Further, since the lock ball 11 has an arcuate surface and the lock ring 13 has an inclined surface 13a, when the lock ring 13 comes into contact with the lock ball 11 fitted in the groove 12 (16), the lock ball 11 into which the lock ring 13 enters. And the inner end surface 12b of the groove 12 are wide at the entrance and gradually narrow, and the entry is smooth, and the both 11 and 13 smoothly abut (lock).

  As shown in FIGS. 4 (a) and 5 (a), the pipes P and P of this embodiment are connected by setting a push-on type rubber ring 6 on the inner surface of the receiving port 2 and receiving the receiving port 2 as shown in FIGS. A lock ring 13 is set in the side groove 12. The lock ring 13 is expanded in diameter by fitting the plate-like diameter expanding tool 19 inserted through the guide groove 18 into the lacking portion 13b, and is accommodated in the groove 12. In this way, if the lock ring 13 is placed in the groove 12, it does not get in the way when the insertion port 1 is inserted, so that the tip of the insertion port 1 has a tapered surface 1a so that the diameter of the lock ring 13 can be increased smoothly. You don't have to.

Thereafter, as shown in FIG. 4B, when the insertion slot 1 is inserted into the receiving slot 2, and the lock ring 13 corresponds to the groove 15 of the insertion slot 1, as shown in FIG. The diameter tool 19 is pulled out to reduce the diameter of the lock ring 13 (tighten) and fit into the groove 15. In the state of the figure (b), since the diameter of the lock ring 13 is expanded, it is possible to confirm the mounting state of the rubber ring 6 into which the insertion slot 1 is inserted using a gauge.
Next, as shown in FIG. 4D, the lock ball 11 is inserted from each hole 14 and rolled by its own weight to reach the circumferential groove 16 so that it can be engaged with the lock ring 13. A screw plug 17 is screwed into each hole 14 to complete the connection of the pipe joint.

  In this pipe joint, as shown in FIG. 6 (a), the lock ring 13 is normally located in the middle of the groove 15, and a large crustal deformation occurs due to an earthquake or the like, as shown in FIG. 6 (b). When the pulling force (arrow) is applied to the pipe P, the lock ring 13 moves in the groove 12 of the receiving port 2 and eventually comes into contact with the inner end face 15b of the groove 15 in contact with the lock ball 11, Further withdrawal of the insertion slot 1 is prevented.

  At this time, as described above, the outer wall surface 16a of the circumferential groove 16 has the same curvature surface as that of the lock ball 11, and the pulling force from the lock ring 13 via the lock ball 11 is the entire curvature surface 16a. Therefore, the stress generated on the outer end surface 16a in the tube axial direction of the circumferential groove 16 and the outer portion 2b around the peripheral groove 16 with respect to the force from the receiving-side lock ball 11 via the insertion-port-side lock ring 13 (Pointed portion in the figure) is widened and stress concentration is relaxed, and the outer portion 2b of the receiving port is hardly damaged. It should be noted that the inclined surface 13a of the lock ring 13 is appropriately determined so that the lock ball 11 is surely brought into contact with the deep curved surface of the outer circumferential wall surface 16a of the circumferential groove, and the lock ball 11 is surely pushed outward (upward in the drawing). To.

On the other hand, as shown in FIG. 5C, when the insertion force (arrow) is applied to the pipe P, the lock ring 13 is prevented from moving on the inner end face 12b of the groove 12 of the receiving port 2 and the groove of the insertion port 1 15 is moved (slids), and eventually comes into contact with the outer end surface 15a of the insertion slot 1 side annular groove 15, and further insertion of the insertion slot 1 is prevented.
In this way, the pipe joint of this embodiment, the withdrawal allowance L ₁ extension or insert narrowing cash L ₂ contract and stretch allowance L min, stretching to fracture is prevented.

  Further, in this embodiment, as shown in FIG. 7, even if the insertion slot 1 is bent with respect to the receiving slot 2 and the axial centers c and c of both are inclined, the lock ring 13 is abutted by the arc surface of the lock ball 11. In order to make contact, the contact point between the lock ring 13 and the lock ball 11 moves along the arc surface to allow the bending, so that the bending is performed smoothly. At this time, the contact on the circular arc surface is smoothly moved, so that the force is evenly applied to the entire periphery, and it is difficult for the contact to occur.

Further, in this embodiment, the lock ball 11 and the lock ring 13 constitute a lock member of the insertion port 1 and the receiving port 2, and the insertion port 1 is changed to the receiving port 2 through the lock ball 11 and the lock ring 13. Since the pulling force is transmitted, the lock ball 11 only needs to have a diameter (thickness) with which the lock ring 13 abuts, and the groove 16 for storing the lock ball 11 stores the lock ball 11, What is necessary is just to have the depth which the insertion port 1 can pass in the accommodation state.
For this reason, the circumferential groove 16 on the receiving side can be made shallower than that of the PII type joint. As a result, the pipe thickness of the receiving port 2 in the groove 16 portion is increased, and the fracture strength is high. obtain.

  In particular, since the lock ball 11 is inserted from the hole 14, the lock ball 11 can be fitted after the insertion port 1 is inserted into the receiving port 2, and the amount of protrusion of the lock ball 11 at the time of insertion is considered. There is no need. For this reason, the circumferential groove 16 that accommodates the lock ball 11 can secure the amount of protrusion to be locked with the lock ring 13 and can withstand the stress at the time of pulling out the insertion port (the area where the lock ball contacts and locks). ), The depth is arbitrary and may be shallow.

In these embodiments, as shown in FIG. 8, the required insertion length L ₂ of the insertion port 1 is inserted in a state where the lock ring 13 is engaged with the inner end surface in the tube axis direction of the receiving-side annular groove 12. Prior to locking to the outer end surface 15a in the tube axis direction of the mouth-side annular groove 15, the tip of the insertion port 1 may be determined by contacting the inner end 2a of the inner surface of the receiving port.
Further, the lock ball 11 can be placed in the grooves 12 and 16 before being inserted into the receiving port 2 of the insertion port 1 without being inserted into the groove 12 or 16 from the hole 14. In this case, the holes 14 and the like can be omitted, and a plurality of lock balls 11 are supported by an elastic member such as a retainer of a ball bearing, and the lock balls 11 are inserted into the grooves 12 or 16 by the elastic force of the openness of the members. It is good to pay.

In order to obtain the pipe joints of these examples by the propulsion method, the jig and the thrust transmission material shown in Patent Document 2 are used and propelled and inserted into the sheath pipe P ′ and the like in the state of FIG. .
JP 2002-276284 A

(A) is the front view of one Example of a pipe joint, (b) is the sectional view on the AA line of (a). (A) is a sectional view taken along line BB in FIG. 1 (b), (b) is a sectional view taken along line CC, and (c) is a sectional view taken along line DD. A lock ring is shown, (a) is a cut side view, (b) is a front view. Connection diagram of the embodiment in the cross section taken along line BB in FIG. Connection action diagram of the same embodiment in the CC cross section Operational diagram of this embodiment Operational diagram of this embodiment Main part cutting front view of another embodiment Cutaway front view of the main part of the conventional example Operation diagram of the conventional example Explanatory drawing of the propulsion method

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Insert port 2 Receptacle port 2a Back end part 2b of receiver inner surface Outer port outer part 6 Sealing rubber ring 11 Lock ball 12 Receiving side annular groove 13 Lock ring 13a Outer end surface 14 of lock ring 15 Insertion side annular groove 15a outer end surface 15b of the insertion-portion side annular groove inner end surface 16 of the insertion-portion-side annular groove 16 circumferential groove 16a outer end surface 17 of the circumferential groove plug 18 guide groove 19 diameter increasing tool 21 insertion port side lock ring P new tube P 'sheath tube ( Existing pipe)

Claims (7)

The insertion port 1 of one tube P is inserted into the receiving port 2 of the other tube P with a rubber ring 6 interposed therebetween, and a required width t ₂ is provided in the tube axis direction on the entire outer periphery of the distal end portion of the insertion port 1. An annular groove 15 is formed, and a lock ring 13 is inserted into the annular groove 15 so as to be movable in the width direction. The insertion port 1 is formed on the entire inner surface of the receiving port 2. An annular groove 12 that allows the diameter of the lock ring 13 to be expanded when inserted into the receiving port 2 is formed, and a lock ball 11 is fitted into the annular groove 12, and the lock ball 11 is inserted into the insertion port side. An anti-seismic pipe joint in which the lock ring 13 fitted in the annular groove 15 is locked in the pull-out direction of the insertion port 1.   Holes 14 are formed in the receptacle 2 so as to communicate with the receptacle-side annular groove 12 from equidistant positions in the circumferential direction of the outer peripheral surface. The lock balls 11 are inserted into the holes 14 so that the receptacle-side annular groove 12 is inserted. Each of the holes 14 has a stopper 17 to prevent the lock ball 11 from coming out, and the lock ball 11 cannot be disengaged from the lock ring 13. The earthquake-resistant pipe joint according to claim 1.   A circumferential groove 16 in the circumferential direction of the receiving-side annular groove 12 is formed from each of the holes 14 so that the lock ball 11 enters the groove 16 so that the lock ring 13 is not disengaged. The earthquake-resistant pipe joint according to claim 2.   4. The wall 14 a of the hole 14 or the circumferential groove 16 that contacts the lock ball 11 in the direction in which the insertion hole 1 is pulled out has the same curvature surface as the lock ball 11. The earthquake-resistant pipe joint described.   The contact surface 13a of the lock ring 13 with the lock ball 11 is an inclined surface or a vertical surface directed toward the axis c of the pipe P in the direction in which the insertion port 1 is pulled out. 4. The earthquake-resistant pipe joint according to any one of 4 above.   The method for connecting earthquake-resistant pipe joints according to claim 2 cited in any one of claims 3 to 5, wherein a rubber ring 6 and a lock ring 13 are loaded into the receiving port 2 of another pipe P, and Insert the insertion port 1 of the pipe P without expanding the diameter of the lock ring 13, fit the lock ring 13 into the insertion port side annular groove 15, and then insert the lock ball 11 from the hole 14 to A method for connecting an earthquake-resistant pipe joint that engages with the lock ring 13 and plugs the hole 14 with a stopper 17.   The insertion port (1) is inserted in a state in which the diameter expansion tool (19) is inserted from the end face opening of the receiving port (2) and the lock ring (13) is expanded in diameter by the diameter expansion tool (19). How to connect earthquake-resistant pipe joints.

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