JP5461885B2 - Metal touch type clamp fitting - Google Patents

Description

  The present invention relates to a metal touch-type clamp fitting that connects and fixes both tubular bodies by butting together connection end portions having flange portions of the tubular bodies and winding and fastening a clamp band around the outer periphery of the joined flange portions.

  In general, in clamp fittings, the connecting ends of the pipe body with flanges are directly abutted with a metal touch type, or with a seal ring type via an annular packing, and a clamp band is wound around the outer periphery of the joined flange part. It is designed to be tightened.

  As shown in FIG. 4 (A), the seal ring type clamp pipe joint is provided with annular recesses 23 at opposite positions on the end faces of both pipes 21 and 22 to be connected, and the entire annular packing 40 is formed. By using a flat ring shape having an annular convex portion 41 on both sides and fitting the annular convex portion 24a into the annular concave portion 23 of both tubular bodies 21, 22, the tubular bodies 21, 22 are centered and joined. This structure is often used (FIG. 2 of Patent Document 1). As shown in FIG. 4B, the clamp band 3 has a pair of substantially C-shaped band halves 31 and 32 each having an inner periphery formed in a groove shape, and are pivotally attached to each other via a pivot 33 on one end side. The band halves 31 and 32 are externally fitted to the flange portions 21a and 22a of the joined pipe bodies 21 and 22, and are fastened to the projecting portion 31a on the other end side of the one band half body 31. The attached bolt 34 is passed through the projecting piece 32a on the other end side of the other band half 32, and the nuts 35 are screwed and tightened to the fastening bolt 34 so that both the tubular bodies 21 and 22 are joined. It comes to fix with. In addition, as shown in the figure, as an annular packing 40 applied to liquid foods, beverages, liquid pharmaceuticals, etc., the surface of a base material 40a made of rubber as an elastic body is used to prevent perfume and impart chemical resistance to rubber. Are provided with a coating layer 40b of fluororesin.

  However, in such a seal-ring type clamp pipe joint, when a load in the vertical direction is applied to one of the two pipe bodies 21 and 22 particularly in a connection portion in a horizontal pipe, as shown in FIG. In addition, since the axial center o of both the tubular bodies 21 and 22 is shifted up and down with the elastic deformation of the annular packing 40, a step is formed in the pipe, so that the liquid pool P is generated at the lower pipe inner bottom. Similarly, even in the case where both pipes 21 and 22 are thermally expanded at the connecting portion of the horizontal pipe, as shown in FIG. 5B, the annular packing 40 pressed from both sides is compressed and deformed to the inside of the pipe. Therefore, the liquid pool P is generated at the bottom of the pipe with the protruding portion 42 of the annular packing 40 as a weir. Therefore, when the pipe sterilization by heating steam is performed under such a condition that the liquid pool P can be generated, there is a concern that condensed water may accumulate in the liquid pool P, resulting in poor sterilization due to insufficient temperature rise. In order to avoid this, there is a problem that the heat energy cost increases by extending the sterilization time or increasing the steam supply amount.

  On the other hand, the conventional metal touch clamp pipe joint has a drawback in that leakage from the pipe joint is liable to occur due to internal pressure because the sealability of the pipe joint is insufficient. Further, the annular packing in the seal ring type is made of metal (Patent Document 2), or the annular protrusion at one end of the tubular body is crimped to the tapered portion at the other end of the tubular body with non-packing (Patent Document 1) Has been proposed. However, with these proposed means, steps and dents on the inner peripheral surface of the pipe, gaps in details, etc. are generated, so it is assumed that sufficient results cannot be obtained in terms of sealing durability, prevention of liquid accumulation, prevention of corruption in gaps, etc. The

  As shown in FIG. 6, an annular groove 51a is provided at a position near the inner periphery of one of the connection end faces of both pipe bodies 51 and 52 to be joined by the metal touch method, and an O-ring 53 is fitted into the annular groove 51a. By doing so, a pipe joint structure in which the sealing performance by the O-ring 53 is loaded on the connection end surface of the metal touch is also conceivable. However, in such a pipe joint structure, the seal position s by the O-ring 53 becomes a compressed portion by both pipe bodies 51 and 52 as shown in the figure, from the gap g connecting the annular groove 51a and the inside of the pipe to the seal positions s on both sides. Since the handling liquid remains in the gap 50 and the washing does not reach the gap 50, there is a concern that the septic of the staying liquid in the gap 50 may leach into the pipe and cause back contamination.

JP 2008-303894A JP 2008-303895 A

  In view of the above-described circumstances, the present invention provides a clamp joint with high rigidity of the connecting portion by metal touch and high sealing performance by the O-ring, and does not cause a step due to misalignment of both side pipes due to external force. In addition, the O-ring does not protrude into the pipe, the liquid does not accumulate in the horizontal piping, and there is no gap that cannot be washed, completely preventing back-contamination due to decay of the accumulated liquid in the gap. It aims to provide what can be done.

If means for achieving the above-mentioned object is shown with reference numerals in the drawings, the invention of claim 1 buttes the connecting end surfaces 11 and 12 having the flange portions 1a and 2a of the pipe bodies 1 and 2 together and joins them. In the metal touch type clamp fitting for connecting and fixing both the tubular bodies 1 and 2 by winding and fastening the clamp band 3 around the outer periphery of the flanges 1a and 2a, the inner peripheral edge of the connecting end of one tubular body 1 An annular groove 4 for fitting an O-ring that is open from the pipe inner peripheral surface 10 side to the connection end surface 11 side is formed in the portion, and the inner peripheral side of the annular groove 4 is flush with the pipe inner peripheral surface 10. An O-ring 7 having an annular protruding edge 5 and having a circular cross section is fitted in the annular groove 4, and the O-ring 7 is deeper than the depth d of the annular groove 4 in the direction of the tube axis o. From the diameter Φ3 of the outer circumferential groove edge of the annular groove 4 having a large cross-sectional circle diameter c Have a larger ring outer diameter .phi.1, in the connected state of the two pipe members 1 and 2, the wall portion of the O-ring 7 which is compressed by press-contact of the other pipe body 2 of the connection end face 12 on the tube side of the annular groove 4 It swells to the open part 4a that faces, and the top end of the bulge part 7a is set to be at the same level or slightly lower than the pipe inner peripheral surface 10, and the inner peripheral side of the outer groove edge of the annular groove 4 is the connection end surface 11 In addition to forming a reverse tapered portion 6a that is reduced in diameter toward the side, the outer peripheral surface of the annular protruding edge portion 5 is formed as a tapered portion 6b that is reduced in diameter toward the connection end surface 11, and the opposing interval w between the reverse tapered portion 6a and the tapered portion 6b Is set to be approximately equal to the cross-sectional circle diameter c of the O-ring 7 .

The invention according to claim 2 is the metal touch clamp joint according to claim 1, wherein the connecting end surface of one tube 1 is provided with an annular recess 13 in the radially intermediate portion of the connecting end surface 12 of the other tube 2. 11 is provided with an annular convex portion 14 fitted into the annular concave portion 13 in the intermediate portion in the radial direction.

According to a third aspect of the present invention, in the metal touch clamp joint of the first or second aspect, the tube axes o of both the tubular bodies 1 and 2 are configured along the horizontal direction.

According to a fourth aspect of the present invention, in the metal touch clamp joint according to any one of the first to third aspects, the O-ring 7 is provided with a coating layer 71 of a fluororesin on the surface of a base material 70 having rubber elasticity. It consists of.

In the metal touch clamp pipe joint according to the first aspect of the present invention, in the annular groove 4 provided at the inner peripheral edge of the connecting end of one pipe body 1, a cross-sectional circle larger than the depth d in the pipe axis o direction. Although the O-ring 7 having the diameter c is fitted, the flesh of the O-ring 7 compressed by the pressing of the connecting end surface 12 of the other tube 2 expands to the open portion 4a facing the inside of the annular groove 4. Since the top end of the bulging portion 7a is set to be the same level as or slightly lower than the pipe inner peripheral surface 10, in addition to obtaining high sealing performance of the connecting portion by the O-ring 7, Due to the high rigidity of the joint due to metal touch, no step due to misalignment of both tubes 1 and 2 due to external force occurs, and further compression of the O-ring 7 even if both tubes 1 and 2 thermally expand Therefore, the O-ring 7 is not deformed so as to protrude into the pipe. . Therefore, according to this clamp fitting, liquid pool does not occur even in the horizontal piping section, so there is no concern that when performing in-tube sterilization with heated steam, condensed water accumulates in the liquid pool and sterilization failure due to insufficient temperature rise occurs. Since heat sterilization can be performed efficiently and reliably, the heat energy cost can be reduced.

  Further, since the O-ring 7 has a ring outer diameter Φ1 larger than the diameter Φ3 of the outer peripheral groove edge of the annular groove 4, the annular groove 4 is in a state before the connection ends of both the tubular bodies 1 and 2 are abutted. Since the O-ring 7 fitted to the tube is less likely to drop off, the connection operation is facilitated, and the width of the opening 4a facing the inside of the tube of the annular groove 4 is narrowed by the annular projecting edge 5, and this narrowed opening 4a is formed. Since the compressed O-ring 7 becomes uneven and swells, the sealing position s between the tubular bodies 1 and 2 by the O-ring 7 is in the vicinity of both side edges of the open portion 4a. A gap that cannot be cleaned is not formed, and back-contamination due to decay of the accumulated liquid in the gap is prevented.

Further , according to the present invention, the inner peripheral side of the outer groove edge of the annular groove 4 forms the reverse tapered portion 6a whose diameter is reduced toward the connection end face 11, and the outer peripheral face of the annular protrusion 5 is reduced in diameter toward the connection end face 11. Since the opposing distance w between the reverse tapered portion 6a and the tapered portion 6b is substantially equal to the cross-sectional circle diameter c of the O-ring 7, the connecting end portions of both tubular bodies 1 and 2 are brought into contact with each other. The O-ring 7 fitted in the annular groove 4 in the previous state is more difficult to drop off, and the mounting operation of the O-ring 7 to the annular groove 4 is facilitated. In addition, the gap between the inner surface of the annular groove 4 and the outer surface of the O-ring 7 before the joining of the tubular bodies 1 and 2 is reduced by the reverse tapered portion 6a and the tapered portion 6b. Due to the uneven thickness of the O-ring 7, the gap is extremely reduced, and the wall portion of the O-ring 7 is strongly pressed against the groove inner surface at the seal positions s on both sides of the open portion 4 a facing the inside of the annular groove 4. Therefore, liquid intrusion into the gap between the annular groove 4 and the O-ring 7 is reliably prevented, and back-contamination due to decay of residual liquid in the gap is completely avoided.

According to the second aspect of the present invention, when the pipes 1 and 2 are connected, the pipes 1 and 2 are simply fitted together with the annular convex part 14 on the other connecting end face 12. The axes of the bodies 1 and 2 can be matched. Moreover, there exists an advantage that what is equipped with the cyclic | annular recessed part for cyclic | annular packing conventionally standardized as the other pipe body 2 which has the cyclic | annular recessed part 13 can be utilized as it is.

According to the invention of claim 3 , the tube axes o of both the tubular bodies 1 and 2 are configured along the horizontal direction. However, since there is no step or protrusion of the seal ring in the tube of the connecting portion, the tube is sterilized by heating steam. There is no concern that condensate will accumulate in the liquid reservoir and cause sterilization failure due to insufficient temperature rise, and heat sterilization can be performed efficiently and reliably, and the heat energy cost can be reduced.

According to the invention of claim 4 , since the O-ring 7 is formed by providing the surface of the base material 70 having rubber elasticity with the coating layer 71 of the fluororesin, the sealing performance excellent in rubber elasticity by the base material. In addition, the coating layer 71 provides good chemical resistance and anti-scenting effect, and since it has a circular cross section, there is an advantage that an inexpensive standard O-ring can be employed.

The metal touch type clamp pipe joint concerning one embodiment of the present invention is shown, (A) is a half section side view of the whole pipe joint, and (B) is an enlarged view in dashed-dotted line circle B of (A). It is a vertical side view which shows the O-ring intervened with both the pipe bodies in the same pipe joint in an exploded state. It is a vertical side view which expands and shows the inner periphery side of the junction edge part in one pipe body of the same pipe joint. The conventional general clamp joint is shown, (A) is a half section side view of the whole pipe joint, (B) is a half section front view of a clamp band. The state of occurrence of a liquid pool due to a conventional general clamp joint is shown. (A) is a side view of a half cross section when the axial centers of both pipes are displaced by a vertical load, and (B) is both It is a half section side view at the time of the annular packing compressed by the thermal expansion of the pipe body protruding to the inner side of the pipe. It is a longitudinal cross-sectional view which shows the connection part of a normal O-ring combined metal touch pipe joint.

  1 (A) and 1 (B), the metal touch type clamp fitting has a flange portion in which connecting end surfaces 11 and 12 having flange portions 1a and 2a of pipes 1 and 2 to be connected are butted together and joined by metal touch. Both clamp bodies 1 and 2 are connected and fixed by winding and tightening clamp bands 3 around the outer peripheries of 1a and 2a, and the tube axis o of both the pipe bodies 1 and 2 is configured along the horizontal direction. The clamp band 3 is the same as that shown in FIG. 4B described in the above-described prior art, and therefore description of each part is omitted here.

One pipe body 1 in this pipe joint has an annular groove 4 opened from the pipe inner peripheral surface 10 side to the connection end face 11 side at the inner peripheral edge of the connection end, and the circular groove 4 has an O-ring 7 having a circular cross section. And an annular convex portion 14 at the intermediate portion in the radial direction of the connection end surface 11. Further, the other tube body 2 has an annular recess 13 corresponding to the annular protrusion 14 of the tube body 1 in the intermediate portion in the radial direction of the connection end surface 12.

  As shown in FIGS. 2 and 3, the annular groove 4 in one tubular body 1 has an open portion 4 a facing the inside of the tube narrowed by an annular projecting edge portion 5 provided at the inner groove edge, and an outer groove. The inner circumferential side of the edge forms a reverse taper portion 6a whose diameter is reduced toward the connection end face 11, and the reverse taper portion 6a makes the outer groove edge diameter Φ2 smaller than the outer maximum groove diameter Φ3. Further, the corner portions 4b on both sides of the groove bottom facing the connection end face 11 side of the annular groove 4 are rounded. The annular projecting edge 5 is flush with the pipe inner surface 10 on the inner peripheral side, but the outer peripheral side, that is, the inner side surface of the annular groove 4 is a tapered portion 6b that decreases in diameter toward the connection end surface 11 side.

  The O-ring 7 is obtained by providing a fluororesin coating layer 71 on the surface of a base material 70 made of an elastic body such as rubber, and a commercially available product can be used. The ring outer diameter Φ1 is larger than the diameter Φ3 of the outer peripheral groove edge of the annular groove 4 of the tube 1 and is substantially equal to the outer maximum groove diameter Φ2. Further, the cross-sectional circle diameter c of the O-ring 7 is larger than the depth d of the annular groove 4 in the tube axis o direction, and the tapered portion 6b on the inner side surface and the reverse tapered portion 6a on the outer side surface of the annular groove 4 Is substantially equal to the facing interval w.

  Thus, in this metal touch clamp pipe joint, the annular convex portion 14 of the tubular body 1 and the annular concave portion of the other tubular body 2 in a state where the O-ring 7 is fitted in the annular groove 4 of one tubular body 1. The connecting end faces 12 of the other tubular body 2 are tightened by winding the clamp band 3 around the outer circumferences of the flange portions 1a and 1b that are joined to each other. The wall portion of the O-ring 7 compressed by the pressing contact bulges to the open portion 4a facing the inside of the tube of the annular groove 4, but the top end of the bulge portion 7a is at the same level as or slightly lower than the inner peripheral surface 10 of the tube. It is set to be.

  In the metal touch type clamp fitting with the above configuration, in addition to obtaining a high sealing performance of the connection portion by the O-ring 7, the joint portion becomes highly rigid by the metal touch between the connection end faces 11 and 12, Even if a load due to an external force in the vertical direction is applied, a step due to the misalignment of both tubes 1 and 2 does not occur, and further compression of the O-ring 7 does not occur even when both tubes 1 and 2 are thermally expanded. The O-ring 7 is not deformed so as to protrude into the pipe, so that no liquid pool is generated in the pipe of the connecting portion even in the horizontal piping portion. Therefore, when in-tube sterilization with heating steam is performed, there is no concern that condensed water will accumulate in the liquid reservoir and cause sterilization failure due to insufficient temperature rise, and heat sterilization can be performed efficiently and reliably, so that the heat energy cost can be reduced.

  In addition to the fact that the O-ring 7 has a ring outer diameter Φ1 larger than the diameter Φ3 of the outer peripheral groove edge of the annular groove 4, the inner peripheral side of the outer groove edge of the annular groove 4 forms the reverse tapered portion 6a. The O-ring 7 fitted in the annular groove 4 is unlikely to drop off before the connection ends of the tubular bodies 1 and 2 are butted, and the inner side surface of the annular groove 4 forms a tapered portion 6b. Since the facing interval w between the portion 6a and the tapered portion 6b is substantially equal to the cross-sectional circle diameter c of the O-ring 7, the O-ring 7 itself can be easily fitted into the annular groove 4. Furthermore, the axial centers of both tubular bodies 1 and 2 can be made coincident by simply fitting the annular convex portion 14 of one tubular body 1 and the annular concave portion 13 of the other tubular body 2. Therefore, in this pipe joint, the connecting operation of both pipe bodies 1 and 2 is very easy.

  Moreover, in the annular groove 4 of the tubular body 1, the width of the open portion 4 a facing the inside of the tube of the annular groove 4 is narrowed by the annular projecting edge portion 5, and the O-ring 7 compressed to the narrow open portion 4 a is unevenly thickened. As shown in FIG. 1B, the sealing position s between the tubular bodies 1 and 2 by the O-ring 7 is in the vicinity of both side edges of the open portion 4a. In addition, the gap between the inner surface of the annular groove 4 and the outer surface of the O-ring 7 before joining the tubular bodies 1 and 2 is reduced by the reverse tapered portion 6a and the tapered portion 6b. In addition to the fact that the corners 4b on both sides of the groove bottom are rounded, the gap is extremely reduced due to the uneven thickness of the compressed O-ring 7 in the joined state of the pipes 1 and 2, and the annular shape. The flesh portion of the O-ring 7 is strongly pressed against the inner surface of the groove at the sealing positions s on both sides of the open portion 4a facing the inside of the tube of the groove 4. Therefore, in this pipe joint, a non-cleanable gap is not formed at the fitting portion of the O-ring 7 and liquid intrusion into the gap between the annular groove 4 and the O-ring 7 at the inner depth from the seal position s is reliably prevented. , Back-contamination due to decay of the residual liquid in the gap is completely avoided.

  The dimensional relationship between the annular groove 4 of the tubular body 1 and the O-ring 7 is not particularly limited, but the depth d in the tube axis direction of the annular groove 4 is in the range of 80 to 90% of the cross-sectional circle diameter c of the O-ring 7. It is recommended that the open width e of the annular groove 4 facing the inside of the pipe is set to a range of 45 to 65% of the depth d in the pipe axis direction. That is, by setting the dimensions as described above, a good sealing property can be obtained particularly at the joint portion, and the bulging portion 7a of the O-ring 7 is formed with respect to the opening portion 4a facing the inner side of the annular groove 4. There is an advantage that an appropriate bulging state is achieved without exceeding the tube inner surface 10a and with few dents on both sides in the width direction.

  On the other hand, in the configuration of this embodiment, the tube body 2 having the annular recess 13 is provided with an annular recess for annular packing that has been standardized conventionally, that is, the tubes 21 and 22 in the conventional configuration of FIG. Available. Further, the O-ring 7 has an advantage that an inexpensive standard O-ring can be adopted. Since the O-ring 7 has a fluororesin coating layer 71 on the surface of the base material 70 having rubber elasticity, the rubber elasticity of the base material 70 provides an excellent sealing property and is excellent by the coating layer 71. Chemical resistance and aroma prevention effect.

DESCRIPTION OF SYMBOLS 1 One pipe body 1a Flange part 10 Pipe inner peripheral surface 11, 12 Connection end surface 13 Annular recessed part 14 Annular convex part 2 The other tubular body 2a Flange part 3 Clamp band 4 Annular groove 4a Open part which faces a pipe inner side 5 Annular rim part 6a Reverse taper part 6b Taper part 7 O ring 7a Swelling part 70 Base material 71 Cover layer c Diameter of cross section d Depth in pipe axis direction e Opening width o Pipe axis w Opposite spacing Φ1 Ring outer diameter Φ2 Maximum outer groove diameter Φ3 Diameter of outer peripheral groove edge of annular groove

Claims (4)

In the metal touch type clamp pipe joint that connects and fixes both pipe bodies by butting the connection end parts having the flange parts of the pipe body, winding a clamp band around the outer periphery of the joined flange part and tightening,
An annular groove for fitting an O-ring that is open from the inner peripheral surface of the tube to the connection end surface is formed on the inner peripheral edge of the connecting end of one of the tubes, and the inner peripheral side is connected to the inner peripheral edge of the annular groove. It has an annular protruding edge that is flush with the surface,
An O-ring formed in a circular cross section is fitted in the annular groove ,
The O-ring, the a large cross-sectional circle diameter than the tube axis direction of the depth of the annular groove, and have a larger ring outer diameter than the diameter of the outer circumferential groove edge of the annular groove,
In the connected state of both pipes, the flesh of the O-ring compressed by the pressing of the connecting end surface of the other pipe bulges to the open part facing the pipe inside the annular groove, and The top end is set to be the same level as the pipe inner peripheral surface or slightly lower ,
The inner peripheral side of the outer groove edge of the annular groove forms a reverse taper portion whose diameter decreases toward the connection end surface side, and the outer peripheral surface of the annular protrusion edge portion forms a taper portion whose diameter decreases toward the connection end surface side. The metal touch clamp joint is characterized in that the interval between the taper portion and the taper portion is set substantially equal to the cross-sectional circle diameter of the O-ring .   An annular recess is provided in a radially intermediate portion of the connection end surface of the other tube body, and an annular protrusion is provided in the radially intermediate portion of the connection end surface of the one tube body to be fitted in the annular recess. Item 2. The metal touch clamp fitting according to item 1. The metal touch type clamp pipe joint according to claim 1 or 2, wherein the pipe axes of both pipe bodies are along the horizontal direction. The metal touch clamp fitting according to any one of claims 1 to 3 , wherein the O-ring is formed by providing a fluororesin coating layer on a surface of a base material having rubber elasticity.

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