JP2009030761A - Pipe removal preventing device for union nut joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily remove a retaining ring 26 from a joint pipe K when loosening a bolt 28 and a nut 29 for reconstruction. <P>SOLUTION: This pipe removal preventing device comprises: the retaining ring 26 externally mounted on the joint pipe K and fastened with the bolt 28 and the nut 29; locking lug portions 27, 27 protrudedly formed on the outer periphery side face of the retaining ring 26; a horseshoe-shaped locking fitting 31 engageable/disengageable with/from an annular recessed portion 30 of a union nut 25; and arms 33 mounted on the outer periphery side face of the locking fitting 31 and having hooks 32 at the front ends, engageable with the locking lug portions 27. The retaining ring 26 has: two opposed and curved externally fitted portions 26b, 26b to be externally fitted to the joint pipe K; bolt insertion portions 36, 37 protruded from one end and the other end of each of the two externally fitted portions 26b toward the outside apart from the joint pipe K; and a fork portion 38. The two externally fitted portions 26b, 26b, the two bolt insertion portions 36, 37 and the fork portion 38 are cast with ductile iron to range over into one unit. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an expansion / contraction flexible pipe joint in which a pipe end portion of a joint pipe not engraved with a screw is inserted into a receiving portion of a pipe or a joint main body, and is fastened with a union nut through a rubber packing. The present invention relates to a provided pipe detachment prevention device.

As shown in FIGS. 13 and 14, the pipe detachment preventing device 1 provided in the expansion / contraction flexible pipe joint described in Patent Document 1 has a male screw 4 engraved on the outer peripheral surface of the receiving portion 3 of the pipe or joint body 2. A circumferential direction on the outer peripheral side surface of the retaining ring 6 facing the union nut 5 screwed and tightened, a retaining ring 6 having a C-shaped outer fitting portion 6a cut out on the outer circumferential surface. The locking ears 7 formed so as to protrude, bolts 8 and nuts 9 for fastening the retaining ring 6 onto the outer peripheral surface of the joint pipe P, the annular recess 10 provided in the union nut 5, and the annular recess 10 And a hook 12 that can be engaged with the locking ear portion 7 of the retaining ring 6 at the tip thereof. And arm 13.
Japanese Patent No. 3858227

  The expansion / contraction flexible pipe joint provided with the pipe detachment prevention device 1 connects the joining pipe K and the pipe or the joint body 2 and, after the pipe detachment prevention device 1 is mounted, for maintenance and repair, or for temporary piping, In some cases, such as when used for house cultivation, pipes are connected for a certain period of time, then disassembled and reassembled at a different location and time for reuse. At this time, the retaining ring 6 is unfastened by tightening the bolts 8 and the nuts 9 to be expanded and removed from the joining pipe K.

  As the tightening of the bolt 8 and the nut 9 proceeds, the retaining ring 6 first undergoes a large plastic deformation on the back side B due to a large bending stress generated on the back side B of the outer fitting portion 6a. Even if the final tightening is loosened, the plastic deformation remains, and the disconnection side A does not naturally expand only by elastic return of the outer fitting portion 6a, but it is necessary to forcibly expand it with a tool and remove it from the joint tube K. is there. Therefore, in the case of re-construction, there is a disadvantage that the retaining ring 6 is expanded and attached to the joining pipe K with a removal tool, and further, the removal tool is removed from the retaining ring 6 and the tool is removed. In particular, in the retaining ring 6 having a size applicable to a small-diameter joining pipe K having an outer diameter of 32 mm or less (corresponding to nominal 25 in the case of a general-purpose HIVP pipe), plastic deformation is remarkable.

  The present invention is intended to provide a pipe detachment prevention device that allows a retaining ring to be easily detached from a joint pipe when bolts and nuts are loosened for re-construction.

  In order to allow the retaining ring to be easily detached from the joint pipe when the bolts and nuts are loosened for re-construction, the means adopted by the present invention according to claim 1 is a receiver in which an external thread is engraved on the outer peripheral surface. A pipe or joint body having a mouth portion is provided with a pipe joint having a structure in which an unthreaded joining pipe is inserted, an annular rubber packing is inserted and interposed, and a union nut is screwed and tightened to the mouth portion. A retaining ring that is externally fitted to the joining pipe on the rear end side of the union nut and is tightened by a bolt and a nut; and a locking ear formed to project from the outer peripheral side surface of the retaining ring along the circumferential direction An annular recess provided in the union nut, a horseshoe-shaped locking bracket detachable with respect to the annular recess, an outer peripheral side surface of the locking bracket, and a locking ear of the retaining ring at the tip Tube detachment with arm with hooks that can engage the part It is a stop device, and the above-mentioned retaining ring protrudes toward the outside away from the joining pipe from one end side of each of the two curved outer fitting parts opposed to the joining pipe and the two outer fitting parts. A bolt insertion portion, and an elastically deformable bifurcated portion extending from the other end side of each of the two outer fitting portions toward the outside away from the joining tube and joining the tip end side, A pipe detachment preventing device for a union nut joint, wherein a fitting portion, two bolt insertion portions, and a bifurcated portion are cast and joined together by ductile cast iron.

  The means adopted by the present invention according to claim 2 to apply to a corresponding joining pipe having a small outer diameter of 32 mm or less is that the retaining ring is fitted on a corresponding joining pipe having an outer diameter of 32 mm or less. Two outer fitting parts are formed in a possible size, and the dimension along the pipe diameter direction from one end of the inner peripheral surface of the two outer fitting parts to the thickness center of the tip of the bifurcated part is defined as the outer diameter of the joining pipe. 2. A pipe detachment preventing device for a union nut joint according to claim 1, wherein a total value obtained by adding a value selected in a range of 8 mm to 18 mm to the dimension is used.

  The means adopted by the present invention according to claim 3 in order to clamp the joint pipe with two outer fitting portions facing each other in a balanced manner is that the bifurcated portion of the retaining ring has a size along the tube diameter direction. 3. The union nut joint disengagement prevention device according to claim 1 or 2, wherein the same two linear regions and a curved region connected to the two linear regions are formed in a U shape.

  In order to secure the final tightening of the bolt and the nut with the set torque, the means adopted by the present invention according to claim 4 is characterized in that the two bolt insertion portions are each formed with a protruding portion facing the opposite surface side. When the bolts and nuts are tightened and finally tightened, the projecting parts are brought into contact with each other so that the retaining ring does not come off from the joint pipe. When the bolts and nuts are loosened and the tightening is released, the retaining ring 4. The pipe detachment preventing device for a union nut joint according to claim 1, wherein the projecting dimensions of the convex parts are determined so that the inner diameter dimension of the two outer fitting parts is larger than the outer diameter dimension of the joining pipe. It is.

  According to a fifth aspect of the present invention, the retaining ring projects a portion of the outer fitting portion closer to the other end from a portion where the two linear regions of the forked portion are joined to the two outer fitting portions. In the state where the bolt and the nut are tightened or not tightened, the distance between the inner surfaces of the two linear regions of the fork is made larger than the distance between the other ends of the two outer fitting parts. An imaginary connecting straight line extending from the intersection of the center line extending in the diameter direction of the joining pipe through the center of the wall thickness of the straight region and the center line extending in the circumferential direction passing through the center of the thickness of the outer fitting part to the center point of the joining pipe The pipe disengagement prevention device for a union nut joint according to claim 1, 2, 3 or 4, wherein the pipe is intersected with a bipartite center line passing through the center point of the joining pipe in a range of 25 ° to 40 °.

  Since the fork removal prevention device for a union nut joint according to the first aspect of the present invention is provided with a bifurcated portion at a location of a retaining ring away from the bolt and the nut, the retaining ring has two outer fitting portions on the joining tube. In the initial stage until contact, plastic deformation does not occur in the bifurcated portion, or even if it occurs, plastic deformation can be made very small, and further, in the stage where the pressing of the two outer fitting portions against the joining tube proceeds, The reaction force transmitted from the joint pipe to the two outer fitting portions gradually reduces the degree of progress of the elastic deformation of the bifurcated portion, so that the plastic deformation does not occur in the bifurcated portion or even if it is caused, the plastic deformation can be made very small. When the bolts and nuts are loosened for re-construction and the final tightening is released, it becomes possible to separate the two external fitting parts with the repulsive elastic force stored in the bifurcated part etc. and naturally expand, Bol for re-construction - it can be easily removed from the joint tube when you loosen the nut.

  According to a second aspect of the present invention, there is provided a pipe detachment preventing device for a union nut joint according to the present invention, wherein two outer fitting portions of a retaining ring having a size corresponding to the joining pipe are fitted on a joining pipe having an outer diameter of 32 mm or less. When this is done, the value along the pipe diameter direction from the one end of the two outer fitting parts to the thickness center of the tip of the bifurcated part is added to the outer diameter dimension of the joining pipe within the range of 8 mm to 18 mm. This makes it possible to prevent plastic deformation at the bifurcated portion (especially at the tip of the bifurcated portion) or to make the plastic deformation very small. It is possible to naturally expand the diameter by separating the two outer fitting portions by the stored rebound elastic force.

  Since the bending moment of the same state arises in the two linear regions of the bifurcated part of the retaining ring, the union nut joint pipe detachment preventing device according to the present invention according to claim 3 has two external fittings for pressing the joint pipe. The force generated in the portion can be made equal, and the two outer fitting portions can be pressed while sandwiching the joining tube in a balanced manner.

  According to a fourth aspect of the present invention, there is provided the union nut joint pipe disengagement preventing device according to the present invention, wherein when the bolts and nuts are tightened and finally tightened, the projections of the two bolt insertion portions come into contact with each other. It is possible to secure the final tightening by tightening the bolts and nuts with an appropriate torque by cautioning the worker not to perform the tightening, and when the bolts and nuts are loosened and the tightening is released, the retaining ring Since the inner diameter is made larger than the outer diameter of the joining pipe, the retaining ring can be detached from the joining pipe.

  The pipe separation preventing device for a union nut joint according to the present invention described in claim 5 is joined to the other end side of the outer fitting portion by adopting the relationship and the value for the separation dimension and the crossing angle with respect to the retaining ring 26. It is possible to generate a pressing force toward the center point of the tube and press the bonded tube reliably.

  FIGS. 1-9 shows embodiment of the pipe | tube removal prevention apparatus for union nut joints based on this invention. 1 to 3 show a tube detachment preventing device 21 before a joining tube is inserted. FIG. 1 is a side view, FIG. 2 is a front view, and FIG. 3 is a cross-sectional plan view. FIG. 4 is a front view of the retaining ring 26 in a temporarily tightened state. 5 (A) to 5 (C) show the locking metal fitting 31 with the arms 33, 33. FIG. 5 (A) is a side view, FIG. 5 (B) is a front view, and FIG. FIG. 6 and 7 show the tube detachment preventing device 21 in which the joining tube K is inserted and the union nut 25 is tightened. FIG. 6 is a cross-sectional plan view showing the left half, and FIG. 7 is a front view. . 8A is a front view obtained by adding a center line or the like to FIG. 7, and FIG. 8B is a separation dimension f of the straight areas 38a, 38a of the bifurcated portion 38 and the outer fitting portions 34, 35. It is a table | surface which shows the range of the dimension which can take the separation dimension g of a lower end. FIG. 9 shows the relationship between the retaining ring 26, the locking fitting 31, and the union nut 25, and FIG. 9A is a side view showing a state before the locking fitting 31 is attached to the retaining ring 26. (B) is a side view showing the case where the locking metal fitting 31 is attached to the retaining ring 26, and FIG. (C) is a side view showing the case where the engaging metal fitting 31 and the retaining ring 26 are attached to the union nut 25, FIG. ) Is a side view showing a state after mounting (a state of temporary assembly).

  As shown in FIGS. 1 and 2, the pipe detachment preventing device 21 according to the present embodiment is a union nut that is screwed and tightened to a male screw 24 engraved on the outer peripheral surface of the receiving portion 23 of the pipe or joint body 22. 25, a retaining ring 26 that is externally fitted to the joint pipe K on the rear end side of the union nut 25 and is tightened by a bolt 28 and a nut 29, and a circumferential direction on the outer peripheral side surface of the retaining ring 26 facing each other. The protruding locking lugs 27, 27, the annular recess 30 provided in the union nut 25, a horseshoe-shaped locking bracket 31 detachable from the annular recess 30, and the locking bracket 31 And arms 33 and 33 having hooks 32 that can be engaged with the locking ears 27 of the retaining ring 26 at the tip, and are made of a plastic such as a hard vinyl chloride pipe or a polyethylene pipe. Pipe, steel pipe with inner and outer peripheral surfaces covered Used in the pipe joint portion of the uncoated steel pipe.

  As shown in FIG. 4, the retaining ring 26 is formed by bending left and right symmetrically and being symmetrically curved and externally fitting to the joint pipe K, and two external fitting parts 34 and 35. Bolt insertion portions 36, 37 extending from one end side A (upper end in the drawing) to the outer side (upward in the drawing) away from the joining tube K, and each of the two outer fitting portions 34, 35 Elastically deformable by extending from the other end B (lower end in the figure) toward the outside (downward in the figure) away from the joining tube K and joining the distal end (lower end in the figure) The two outer fitting portions 34 and 35, the two bolt insertion portions 36 and 37, and the one forked portion 38 are cast from ductile cast iron and integrally connected. As shown in FIG. 9A and FIG. 4, the left and right locking ear portions 27, 27 of the retaining ring 26 are formed by the left and right curved outer fitting portions 34, 35 when viewed from the side. It has a streak shape extending along the circumferential direction, and is integrally formed with the outer fitting portions 34 and 35 by casting.

  As shown in FIG. 4, the two bolt insertion portions 36 and 37 of the retaining ring 26 are opposed to the main body portions 36a and 37a connected to the two outer fitting portions 34 and 35 and the opposing surface sides of the main body portions 36a and 37a, respectively. The projections 36b and 37b are formed so as to project. As shown in FIG. 7, when the bolts and nuts 28 and 29 are tightened with a set torque and finally tightened, the projections 36b and 37b are brought into contact with each other. To prevent further tightening (if the bolts and nuts 28 and 29 are tightened after the projections 36b and 37b abut, the tightening torque will increase rapidly) It is possible to secure a final tightening by tightening bolts and nuts 28 and 29 with an appropriate torque. The projecting dimensions of these projecting portions 36b and 37b are such that when the bolts and nuts 28 and 29 are tightened and finally tightened, the projecting portions are brought into contact with each other so that the saw blade 26a bites into the joining tube K and cannot be removed. Further, when the bolts and nuts 28 and 29 are loosened after the projections are brought into contact with each other and the tightening is released, the retaining ring 26 sets the inner diameter dimension of the two outer fitting sections 34 and 35 to the outer diameter dimension of the joining pipe K. Decided to be larger.

  As shown in FIG. 4, the retaining ring 26 has two outer parts when a nut 29 is screwed into a bolt 28 passed through bolt insertion portions 36 and 37 and the bolts and nuts 28 and 29 are temporarily tightened. The joint tube K can be inserted in a loose state between the fitting portions 34 and 35. Then, as shown in FIG. 7, when the bolts and nuts 28 and 29 are finally tightened, two external fittings are provided. A large number of saw teeth 26a (see FIG. 6) engraved on the inner peripheral surfaces of the outer fitting portions 34, 35 by bringing the joining pipes K between the two outer fitting portions 34, 35 by bringing the portions 34, 35 closer to each other. Can be made to bite into the outer peripheral surface of the joining tube K to exhibit the anti-slip function.

  The retaining ring 26 is disposed on the distal end side of the bifurcated portion 38 until the inner peripheral surfaces of the two outer fitting portions 34 and 35 are brought into contact with the outer peripheral surface of the joint pipe K by tightening the bolts and nuts 28 and 29. A bending moment is generated. The bending stress generated on the distal end side of the bifurcated portion 38 due to this bending moment is caused by the center of thickness at the distal end of the bifurcated portion 38 from one end 34a, 35a (see FIG. 4) of the inner peripheral surfaces of the two outer fitting portions 34, 35. Since the dimension L along the pipe diameter direction leading to C becomes longer by the provision of the bifurcated portion 38, the back side (the other end side B) of the outer fitting portion 6a of the conventional retaining ring 6 (see FIGS. 13 and 14). It can be made smaller than the bending stress that occurs. For this reason, the retaining ring 26 does not cause plastic deformation in the bifurcated portion 38 in the initial stage until the two outer fitting portions 34 and 35 are brought into contact with the joining pipe K, or very much plastic deformation occurs. You can make it smaller.

  The retaining ring 26 has a tightening force of the bolts and nuts 28 and 29 as the final tightening of the bolts and nuts 28 and 29 proceeds after the two outer fitting portions 34 and 35 are brought into contact with the joint pipe K. In addition, the two external fitting portions 34 and 35 and the bifurcated portion 38 are elastically deformed in response to the reaction force from the joining pipe K, and the internal force and the external fitting of both 34 and 38 at the boundary between the outer fitting portion 34 and the bifurcated portion 38 The internal forces of both the portions 35 and 38 at the boundary portion between the portion 35 and the bifurcated portion 38 are balanced. The two outer fitting portions 34 and 35 receive the tightening force of the bolts and nuts 28 and 29 from the one end side A through the bolt insertion portions 36 and 37, and the other end receives the force of the bifurcated portion 38 that is elastically deformed. Receiving from the side B, the outer peripheral surface of the joining pipe K is pressed. When the retaining ring 26 is pressed against the joining pipe K by the two outer fitting portions 34, 35, the degree of progress of the elastic deformation of the bifurcated portion 38 by the reaction force transmitted from the joining pipe K to the two outer fitting portions 34, 35. Gradually decreases, and the two outer fitting portions 34 and 35 gradually press the joining tube K gradually and tighten it.

  The two outer fitting portions 34 and 35 receive forces from both end sides A and B in this way and press the outer peripheral surface of the joining pipe K (indicated by pressing forces P1, P2 and P3 in FIG. 8). By reducing the difference between the pressing force P1 and the pressing force P3 with respect to the joining pipe K of A and B, the pressing force with respect to the joining pipe K can be made closer to the circumference of the pipe. On the other hand, since the conventional retaining ring 6 (see FIGS. 13 and 14) does not have a bifurcated portion on the other end side, there is a large difference in the pressing force against the joining pipe K on both end sides A and B. The pressing force against K becomes non-uniform in the tube peripheral direction.

  As described above, the retaining ring 26 does not cause plastic deformation in the bifurcated portion 38 in the initial stage until the two outer fitting portions 34 and 35 are brought into contact with the joining pipe K, or plastic deformation does not occur. Further, the elastic force of the bifurcated portion 38 can be reduced by a reaction force transmitted from the joint tube K to the two outer fitting portions 34 and 35 when the two outer fitting portions 34 and 35 are pressed against the joining tube K. Since the degree of progress of deformation gradually decreases, plastic deformation does not occur in the bifurcated portion 38, or even if it occurs, plastic deformation can be made very small. Therefore, the bolts and nuts 28 and 29 are loosened for re-installation. When the tightening is released, the rebound elastic force stored in the bifurcated portion 38 or the like allows the two outer fitting portions 34 and 35 to be separated and expanded naturally, and the bolts and nuts 28 are re-installed. , 29 when loosened It can be easily removed from the case tube K.

  As shown in FIG. 4A and FIG. 9A, the retaining ring 26 has a pipe outer diameter of 32 mm (corresponding to a nominal 25 in the case of a general-purpose HIVP pipe), and a pipe outer diameter of 26 mm (same as above). Nominal 20), pipe outer diameter of 22 mm (corresponding to the same nominal 16), and pipe outer diameter of 18 mm (corresponding to the same nominal 13) of small diameter joining pipe K, 32 mm of outer diameter The two outer fitting portions 34 and 35 are curvedly formed to have a size that can be fitted to the selected joining tube K below, and the two forked portions are formed from one ends 34a and 35a (see FIG. 4) of the two outer fitting portions 34 and 35. 38 is a value obtained by adding a value selected in the range of 8 mm to 18 mm to the outer diameter dimension of the joining pipe K, the dimension L along the pipe diameter direction leading to the wall thickness center portion C at the tip of 38 (specifically, the outer diameter of the pipe When the dimension is 32 mm, the dimension L is 40 to 50 mm, and the outer diameter of the tube is 26 mm. The dimension L is 34 mm to 44 mm, the dimension L is 30 mm to 40 mm when the tube outer diameter is 22 mm, and the dimension L is 26 mm to 36 mm when the tube outer diameter is 18 mm. For the two outer fitting portions 34 and 35 and the forked portion 38, the thickness dimension t (excluding the saw tooth 26a) is in the range of 3.0 mm to 5.0 mm, and the front-rear depth dimension n (see FIG. 9A). ) In a range of 15 mm to 10 mm, the bending moment on the distal end side of the bifurcated portion 38 where the large bending moment is generated in the retaining ring 26 is suppressed so as not to cause plastic deformation, or plastic deformation is prevented. It is made very small so that when it is fully tightened, it is naturally expanded by the repulsive elastic force stored in the bifurcated portion 38, etc., and can be opened or easily opened to the joint tube K. It is to be able.

  As shown in FIG. 4, the bifurcated portion 38 of the retaining ring 26 has two linear regions 38 a and 38 a that are separated from each other along the tube diameter direction and have the same size, and a curved line that continues to the two linear regions 38 a and 38 a. It is formed in a U-shape with the region 38b, and when the bolt 28 and the nut 29 are tightened, a bending moment in the same state is generated in the two linear regions 38a, 38a, so that two outer parts for pressing the joint pipe K are formed. The force generated in the fitting portions 34 and 35 is made equal, and the joining tube K is clamped between the two outer fitting portions 34 and 35 in a balanced manner. In addition, the bifurcated portion 38 can be made U-shaped so that the thickness of the forged portion 38 is less likely to cause poor hot water during casting.

  As shown in FIG. 8 (A), the retaining ring 26 is connected to the outer fitting portion 34 (35) at a position where the straight region 38a (38a) of the bifurcated portion 38 is joined to the other end 34c of the outer fitting portion 34 (35). (35c) The portion on the near side is overhanging. The retaining ring 26 has two straight areas 38a, 38a of the bifurcated portion 38 in a state immediately after the bolts and nuts 28, 29 are tightened and the convex portions 36b, 37b of the bolt insertion portions 36, 37 are brought into contact with each other. The separation dimension f is set apart (refer to the table in FIG. 5B for the range of values specifically taken for the selected joining pipe K), and the other ends 34c of the two outer fitting parts 34, 35 are provided. 35c is separated from each other to form a separation dimension g (refer to the table in FIG. 5B for the range of values specifically taken for the selected joining pipe K), and the relationship between the separation dimension f and the separation dimension g. f> g (preferably f> 2.5 g), and a center line v and an outer fitting portion extending in the vertical direction (diameter direction of the joining pipe K) passing through the center of the thickness of the straight region 38a of the bifurcated portion 38 The junction tube K from the intersection u with the center line s extending in the circumferential direction passing through the center of the thickness of 34, 35 The connecting imaginary straight line y extending to the center point Ka passes through the center point Ka of the joining pipe K and is divided into two split center lines w and a crossing angle θ (specifically, the value is θ = 30 ° (+ 10 ° Is in the range of θ = 25 ° to 40 °). It is preferable that the separation dimension f of the two linear regions 38a, 38a of the bifurcated portion 38 is about the radial dimension of the joining pipe K.

  Regarding the relationship between the separation dimension f and the separation dimension g of the retaining ring 26 and the intersection angle θ, the state immediately after the projections 36b and 37b of the bolt insertion parts 36 and 37 are brought into contact as described above has been described. The relationship between the separation dimension f and the separation dimension g is f> g, and the crossing angle θ is 25 ° to 40 ° even when the bolts and nuts before the projections 36b and 37b are brought into contact with each other are not tightened or tightened. It may be in the range of °.

  The retaining ring 26 adopts the above relationship and values for the separation dimensions f and g and the crossing angle θ, so that the center point Ka of the joining pipe K is located on the other end 34c (35c) side of the outer fitting portion 34 (35). The joining pipe K can be surely pressed by generating the pressing force P3 toward the head.

  As shown in FIG. 5B, the engagement fitting 31 that is detachably fitted to the annular recess 30 of the union nut 25 has a horseshoe shape. The outer diameter d4 (see FIG. 3) of the groove bottom 30a of the annular recess 30 of the union nut 25 is set to be smaller. In addition, the outer diameter d4 of the groove bottom 30a is set smaller than the diameter D1 of the inner peripheral surface of the locking fitting 31. That is, the dimensional relationship of D1> d4> E is set. As described above, the arms 33 and 33 each having the hook 32 that can be locked to the locking ear portion 27 of the retaining ring 26 are attached to the opposing outer peripheral side surfaces of the locking fitting 31. . Each arm 33 is provided with a protrusion 33b for rotation prevention below the arm main body 33a, and is integrally formed with the locking fitting 31 by casting ductile cast iron.

  The retaining ring 26, the locking bracket 31 with the arms 33 and 33, and the union nut 25 configured in this way can configure a pipe joint, and are set in a relationship that exhibits flexibility and stretchability when the pipe joint is configured. Has been. As shown in FIG. 2, the arms 33, 33 have an inner peripheral surface 32 b of the hook 32 formed in a curved concave shape, and as shown in FIG. 9, the inner surface of the hook 32 extends from the rear end surface 31 a of the locking metal fitting 31. By making the dimension h up to 32a larger than the front-rear depth dimension n of the retaining ring 26, the retaining ring 26 in the temporarily tightened state is inserted between the arms (see FIG. 5B), and the hook 32 is secured to the retaining ring 26. Can be moved from the outside to the outer peripheral surface 34a (35a) of the outer fitting portion 34 (35) along the tube axis direction (front-rear direction) (see FIG. 3C). The hook 32 that has moved in this state is engaged in the tangential direction (vertical direction) of the curved outer peripheral surface 34 a (35 a) of the outer fitting portion 34 (35) of the retaining ring 26 and vertically To prevent separation. Further, the locking bracket 31 is configured so that the rotation-preventing convex portion 33b of each hook 32 can be brought into contact with the locking ear portion 27 of the retaining ring 26, so that the rotational direction deviation from the retaining ring 26 is reduced. Thus, the hook 32 can be securely locked to the locking ear portion 27 of the retaining ring 26. Further, as shown in FIG. 9C, the arms 33 and 33 have a groove width dimension i of the notch groove 33c on the root side and a thickness dimension m of the flange part 39 that forms the annular recess 30 of the union nut 25. The engagement metal fitting 31 can be externally fitted to the annular recess 30 of the union nut 25. The retaining ring 26 has a front and rear depth dimension n set to a value larger than a value (hm) obtained by subtracting the dimension m in the flange portion 39 from the dimension h in the locking bracket 31. The fitting 31 is prevented from being detached from the locking fitting 31 after being attached to the union nut 25. The retaining ring 26 is obtained by adding the sum of the thickness dimension j (dimension along the tube axis direction (front-rear direction)) of the locking ear portion 27 and the thickness dimension m of the flange portion 39 of the union nut 25 to the notch of the arm 33. By making it larger than the groove width dimension i of the groove 33 c (j + m> i), the rotation-preventing convex shape 33 b of the arm 33 can be brought into contact with the locking ear portion 27.

  The union nut joint pipe detachment preventing device 21 configured as described above is cast-molded in a factory, temporarily assembled as necessary, and shipped in this state. First, as shown in FIG. 3, the temporary assembly is performed by inserting a packing 40 into the inner peripheral surface side of the union nut 25 and engraving the whole on the outer peripheral surface of the receiving portion 23 of the joint body 22. Screw to 24. Subsequently, as shown in FIGS. 3 and 2, the hook 32 of the locking bracket 31 is placed on the outer peripheral surfaces 34 a and 35 a of the outer fitting portions 34 and 35 of the retaining ring 26 in a state where the bolt 28 and the nut 29 are temporarily tightened. 32 is externally fitted so that the hooks 32, 32 can be engaged with the locking ears 27, 27. As shown in FIGS. 9A and 9B, the hook 32 is engaged in a state in which the front end surface 26b of the retaining ring 26 and the rear end surface 31a of the locking metal 31 are joined. The retaining ring 26 and the retaining bracket 31 are relatively moved so that the arm 33 of the retaining member 31 overlaps the retaining ear 27 of the retaining ring 26. Then, the hook 32 at the tip of the arm 33 is slid forward to the locking ear 27 so that the entire locking bracket 31 is slid forward, and as shown in FIG. Increase the interval.

  Next, the union nut 25 is moved from the lower side to the upper side of the locking metal 31 or the locking metal 31 is lowered with respect to the union nut 25, and as shown in FIG. Is fitted into the annular recess 30 of the union nut 25. At this time, the frontage dimension E (see FIG. 5) of the opening of the engagement fitting 31 having a horseshoe shape is set to be smaller than the outer diameter d4 (see FIG. 3) of the groove bottom 12A of the annular recess 30. Therefore, it is forced to fit while increasing the frontage dimension E. As shown in FIG. 4D, the locking metal fitting 31 does not fall off from the union nut 25 due to the dimensional relationship of d4> E after forcibly fitting. Further, the hooks 32 and 32 at the tips of the arms 33 and 33 that are fitted and engaged with the outer fitting portions 34 and 35 of the retaining ring 26 do not fall off the retaining ring 26. That is, the retaining ring 26, the locking fitting 31, and the union nut 25 are present in cooperation as one set in a temporarily assembled state.

  At the construction site, the joining tube K is inserted into the tube disassembly preventing device 21 in the temporarily assembled state. Since the central axes of the retaining ring 26, the union nut 25, the packing 40, and the joint body 22 coincide with each other in the temporarily assembled state, the insertion opening on the distal end side of the joining pipe K is connected to the retaining ring 26 side. Is simply inserted through the union nut 25 and packing 40 to reach into the joint body 22, which is extremely easy. Thereafter, the union nut 25 is manually rotated to temporarily fix the joining pipe K, and then tightened to the minimum tightening torque necessary for water tightness with a spanner or a pipe wrench. After confirming that the retightening of the union nut 25 has been completed, the union nut 25 is rotated so that the fastening portion by the bolt 28 and the nut 29 is easily tightened (position where the fastening portion is located above). Let Finally, the retaining ring 26 is fastened. The fastening of the retaining ring 26 is performed by determining the axial positioning with respect to the joining pipe K and the direction of the bolt fastening portion (positioned upward as shown in FIGS. 1, 2, and 7), and then the bolt / nut 28. , 29 are tightened, and the saw-tooth 26a engraved on the inner peripheral surface of the retaining ring 26 is bitten into the outer peripheral surface of the joint tube K so as to exhibit the anti-slip function.

  Thereby, as shown in FIG. 6, the joining tube K can be flexibly expanded and contracted within a range in which the hook 32 can move on the retaining ring 26. Further, even after the construction, even when a force in the tube detaching direction is applied between the joint tube K and the joint body 22, the hook 32 at the tip of the arm of the locking fitting 31 is the locking ear of the retaining ring 26. Since the engagement fitting 31 is fitted on the annular recess 30 of the union nut 25 in contact with the portion 27, the joining tube K is prevented from being detached.

In order to confirm the effect of the present invention, the inventor made a test product of a ductile cast iron retaining ring used in the present invention shown in FIG. 10 (A) and FIG. D) A conventional ductile cast iron retaining ring test product shown in D) is performed, and a tightening test is performed for an outer diameter of 22 mm (general-use HIVP pipe nominal 16) as shown in FIGS. 11 and 12. The result shown in was obtained. The bolts and nuts of each test product use M5, and the dimensions of the test product are a = 8.00 mm, b = 22.25 mm, c = 11.50 mm, e = 25.50 mm, t = 4.00 mm, n = 14.0 mm. As the material of the retaining ring, a ductile cast iron having a type of FCD420, a tensile strength of 460 N / mm ² and an elongation of 15% was used. As a torque wrench for tightening the nut, a preset type torque wrench (model: T2LN6) manufactured by Maeda Metal Industry Co., Ltd. having a measurement range of 1 to 6 N · m was used. Bolts and nuts were tested by applying an anti-seizure agent.

  For the tightening test, the first test shown in FIG. 11 and the second test shown in FIG. 12 were performed. In the first test, as shown in FIG. 11A, in both the present invention and the conventional retaining ring, the nut is tightened until T2 = 1.50 mm, and then the nut is tightened. It was opened, and the relationship between the state with respect to the joining pipe and the tightening torque value of the nut and the measured dimension values of the gaps T1, T2, T3 was obtained. It should be noted that the tightening torque of the nut when the saw blade (shown by reference numeral 26a in FIG. 6) contacts the joining pipe was a small value that could not be read. The figure (B) shows the internal-diameter dimension value of the sawtooth of each location in the state before a test (before fastening) and after a test (open | release after fastening). In the first test, the tightening torque of the nut is small, and in both the present invention and the conventional retaining ring, the diameter is naturally expanded until it can be detached from the joint pipe after the test.

  In the second test, as shown in FIG. 12A, in both the present invention and the conventional retaining ring, the nut is tightened until T2 = 1.00 mm, and then the nut is tightened. After loosening and opening, the relationship between the state of the joint pipe and the tightening torque value of the nut, and the measured dimension values of the gaps T1, T2, T3 were obtained. When the nut is loosened and released, in the case of the present invention, the diameter naturally expands until it can be detached from the joint pipe after the test, whereas in the conventional case, the joint pipe cannot be detached from the joint pipe after the test. It was still tightened.

  In the case of the present invention in the second test, T3 shown in FIG. 12A decreases as the nut tightening proceeds, but the value when the nut tightening is released is the value before the tightening. Therefore, it can be seen that only the elastic deformation occurs in the bifurcated portion 38 (see FIG. 4) without plastic deformation. In addition, as for the gaps T1 and T2, since the value when the nut is tightened is slightly smaller than the value before the tightening, some plastic deformation occurs in the outer fitting portions 34 and 35 (see FIG. 4). However, the values of the inner diameter dimensions d1, d2, and d3 of the saw teeth when released after tightening are approximate, and it can be seen that the plastic deformation has occurred in a state close to a perfect circle.

  On the other hand, in the conventional case in the second test, since it does not detach from the joint tube after the test, a large plastic deformation occurs in the C-shaped outer fitting portion 6a (see FIG. 14). I understand.

  In the second test, the maximum value of T2 (hereinafter referred to as “pipe detachment limit value”) that can be naturally expanded and released from the joined pipe when the nut is loosened and released is not calculated. It can be estimated. The allowable range of T2 that can be tightened so that the pipe can be detached after contacting the sawtooth of the retaining ring with the joining pipe is based on a value when the sawtooth starts to contact the joining pipe (hereinafter referred to as “pipe contact start value”). Since it can be evaluated by the value of ΔT2 obtained by subtracting the tube detachment limit value, when the tube detachment limit value is estimated as T2 = 0.90 mm and the conventional case is estimated as T2 = 1.30 mm, the present invention In this case, ΔT2 = 4.80−0.90 = 3.90 mm, whereas in the conventional case, ΔT2 = 3.74-1.30 = 2.44 mm, which is the case of the present invention. large.

  Further, the minimum amount of tightening required to bring the saw blade 26a of the retaining ring 26 into contact with the joining pipe K and then bring the saw tooth 26a into the joining pipe K to exhibit the anti-slip function is evaluated as T2. This corresponds to a reduction of 00 mm. The range from the value of T2 that causes the saw blade 26a to bite into the joining pipe K and exerts the anti-slip function can be evaluated as the margin range S at the time of final tightening, and the margin range S in the case of the present invention. = 4.80-2.00-0.90 = 1.90 mm, while the margin range S in the conventional case is 3.74-2.00-1.30 = 0.44 mm. The case of the invention is about 4 times larger.

  By the way, the ductile cast iron used as the material of the retaining ring 26 has a large variation in mechanical properties such as tensile strength, and also has a large tolerance in casting. Furthermore, the joining pipe K also has an outer diameter tolerance. In order to tighten the retaining ring so that the non-slip function is exerted on the joining pipe, it is necessary to absorb these large variations and tolerances. In the case of the present invention, since the margin range S at the time of final tightening is large, it is possible to absorb these large variations and tolerances, and to reliably exhibit the anti-slip function of the retaining ring 26 with respect to the joint pipe K. It becomes like this. On the other hand, in the conventional case, since the margin range S at the time of final tightening is small, it becomes very difficult to absorb these large variations and tolerances, and the anti-slip function of the retaining ring 6 with respect to the joining pipe K is ensured. May not be able to be demonstrated.

  In the case of the present invention, since the margin range S at the time of final tightening is large, the bolts and nuts 28 and 29 are loosened and released after contacting the convex portions 36b and 37b of the two bolt insertion portions 36 and 37. If the projecting dimensions of the two protrusions 36b and 37b are set in a casting mold so that the diameter can be naturally expanded and removed from the joining tube K, the margin range S during the final tightening can be obtained. It is possible to obtain a cast ring retaining ring 26, which can securely tighten the retaining ring 26 to the joint pipe K regardless of who fastens the bolts and nuts 28, 29. By loosening, the retaining ring 26 can be reliably detached from the joint tube K. On the other hand, the conventional retaining ring 6 has a small margin range S at the time of final tightening, so it is difficult to set the protruding dimensions of the projections of the two bolt insertion portions to a casting mold, and the margin range at the time of final tightening It is difficult to obtain a cast ring that fits in S.

It is a side view which shows before inserting a joining pipe | tube in the pipe detachment | leave prevention apparatus which concerns on embodiment of this invention. It is a front view which shows the state before inserting a joining pipe | tube in the pipe | tube removal prevention apparatus which concerns on the embodiment. It is the top view which carried out the cross section which shows the state before inserting a joining pipe | tube in the pipe detachment | leave prevention apparatus concerning the embodiment. It is a front view of the retaining ring of the state temporarily tightened of the pipe detachment preventing device according to the embodiment. FIG. 2 shows a locking fitting with an arm of the pipe detachment preventing device according to the embodiment, in which FIG. (A) is a side view, FIG. (B) is a front view, and FIG. (C) is a bottom view. In the pipe detachment preventing apparatus according to the same embodiment, it is a cross-sectional plan view showing a left half of a state where a joining pipe is inserted and a union nut is tightened. In the pipe detachment preventing apparatus according to the embodiment, it is a front view showing a state in which a joining pipe is inserted and a union nut is tightened. (A) is a front view obtained by adding a center line or the like to FIG. 7, and (B) in FIG. 7 is a range of dimensions that can be taken as a separation dimension of a straight region of a bifurcated part and a separation dimension of a lower end of an outer fitting part. It is a table | surface which shows. FIG. 1 shows a pipe detachment preventing device according to the embodiment, in which FIG. (A) is a side view showing a state before mounting a locking bracket on a retaining ring, and FIG. Side view showing the case of mounting, FIG. (C) is a side view showing the case of mounting the locking bracket and retaining ring to the union nut, and FIG. (D) is a side view showing the state after mounting (temporary assembly state). It is. Figures (A) and (B) are a front view and a side view of a retaining ring in the case of the present invention used for a confirmation test. Figures (C) and (D) are conventional retaining rings of a test product used for a confirmation test. It is the front view and side view which show. Figures (A) and (B) are tables showing the results of the first test. Figures (A) and (B) are tables showing the results of the second test. It is the side view which shows the whole conventional pipe detachment | desorption prevention apparatus, Comprising: One part is fractured | ruptured and shown. It is a front view of the conventional pipe detachment preventing device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 21 ... Detachment prevention apparatus, 22 ... Joint body, 23 ... Receiving part, 24 ... Male screw, 25 ... Union nut, 26 ... Retaining ring, 27 ... Locking ear part, 28 ... Bolt, 29 ... Nut, 30 ... Ring Recessed portion, 31 ... locking metal fitting, 32 ... hook, 33 ... arm, 34 ... outer fitting portion, 35 ... outer fitting portion, 36 ... bolt insertion portion, 37 ... bolt insertion portion, 38 ... bifurcated portion, 40 ... packing

Claims (5)

  Insert a screw-free joining tube into a pipe or joint body with a receiving part with a male thread engraved on the outer peripheral surface, insert an annular rubber packing, and tighten the union nut to the receiving part. A retaining ring that is provided on a pipe joint having a structure, is fitted to a joint pipe on the rear end side of the union nut and is tightened by a bolt and a nut, and protrudes along the outer circumferential side surface of the retaining ring along the circumferential direction. The formed locking ear, an annular recess provided in the union nut, a horseshoe-shaped locking bracket that is detachable with respect to the annular recess, and an outer peripheral side surface of the locking bracket, And an arm with a hook that can be engaged with a locking ear of the retaining ring, wherein the retaining ring has two curved outer surfaces that are externally fitted to the joint tube. The outer side of the fitting part and the outer fitting part from one end side of each of the two outer fitting parts A bolt insertion portion protruding toward the outside, and an elastically deformable bifurcated portion extending from the other end side of each of the two outer fitting portions toward the outside away from the joining tube and joining the tip end side. 2. A pipe disengagement prevention apparatus for a union nut joint, wherein two outer fitting parts, two bolt insertion parts, and a fork part are cast and joined together by ductile cast iron.   The retaining ring is formed with two outer fitting parts having a size that can be fitted onto a corresponding joining pipe having an outer diameter of 32 mm or less, and from the one end of the inner peripheral surface of the two outer fitting parts to the tip of the bifurcated part. 2. A pipe detachment preventing device for a union nut joint according to claim 1, wherein the dimension along the pipe diameter direction leading to the wall thickness center is a total value obtained by adding a value selected in the range of 8 mm to 18 mm to the outer diameter dimension of the joined pipe. .   The bifurcated portion of the retaining ring is formed in a U shape by two linear regions having the same size along the tube diameter direction and a curved region connected to the two linear regions. Pipe separation prevention device for union nut joints.   The two bolt insertion portions are each formed with a protruding portion facing the opposite surface side, and when the bolt and nut are tightened and finally tightened, the protruding portions are brought into contact with each other so that the retaining ring comes from the joining pipe. When the bolts and nuts are loosened and the tightening is released, the retaining ring projects the protrusions so that the inner diameter of the two outer fitting parts is larger than the outer diameter of the joint pipe. The pipe detachment preventing device for a union nut joint according to claim 1, 2 or 3, wherein the dimension is determined.   In the state in which the retaining ring protrudes from the portion where the two linear regions of the bifurcated portion are joined to the two outer fitting portions, the portion closer to the other end of each outer fitting portion, and the bolt and nut are tightened or not tightened. The distance between the inner surfaces of the two straight areas of the forked part is made larger than the distance between the other ends of the two outer fitting parts, and further, through the center of the wall thickness of the straight part of the two forked parts, A connecting virtual straight line extending from the intersection of the center line extending in the diameter direction and the center line extending in the circumferential direction passing through the center of the thickness of the outer fitting portion to the center point of the joint pipe is divided into two split center lines passing through the center point of the joint pipe The pipe | tube removal prevention apparatus for union nut joints of Claim 1, 2, 3 or 4 crossed in the range of 25 degrees-40 degrees.

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