JP2010084880A - Pipe joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further enhance the locking effect of a water pipe by improving a biting structure to the water pipe while ensuring a high fastening force by uniformly reducing the diameter of the whole body so as not to cause biased fastening of a chuck ring. <P>SOLUTION: The pipe joint includes: a joint body having an annular space between an external thread body and a water-passing sleeve as an insert part of the water pipe, in which a tapered port gradually reduced in diameter is formed at an opening of the external thread body and an outward projection is formed on the outer circumferential surface of the water-passing sleeve; a cap nut having a reversed tapered port reversed to the tapered port at an inner surface opening, the cap nut being screwed to the external thread body; and a chuck ring having tapered surfaces corresponding respectively to the tapered port and the reversed tapered port, which are formed on the outer surface at both sides. A pair of inward projections is formed in symmetric positions across the outward projection in an internal insert hole of the chuck ring, and the tapered port and the reversed tapered port have the same inclination in linear symmetry. On the outer circumferential surface of the water-passing sleeve, a pair of inward recessed parts facing respectively the inward projections of the chuck ring is formed across the outward projection. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an improvement of a pipe joint in which a water pipe such as a resin pipe inserted into a joint body is held by reducing the diameter of a chuck ring by tightening a cap nut.

  When the pipe to be connected (referred to as a water pipe) is a resin pipe or a three-layer pipe in which a resin layer is formed inside and outside the metal layer, the water pipe is inserted through a split ring-shaped chuck ring, The diameter of the chuck ring is reduced by tightening the cap nut that is screwed onto the joint body, so that the water pipe is tightened and the protrusions (biting teeth) in the chuck ring are bitten into the pipe surface to prevent the water pipe from coming off. Such pipe joints are known, and the present applicant has proposed a plurality of cases so far (see, for example, Patent Documents 1 to 6).

JP 2000-46272 A JP 2001-41378 A JP 2002-81586 A JP 2002-115785 A JP 2003-130274 A JP 2006-138378 A

  By the way, in the above-mentioned conventional pipe joint, the chuck ring has a tapered surface on one outer surface on the side of the cap nut, and the cap nut has a tapered port that fits the tapered surface. As the screwing progresses, the inner pressure dimension of the chuck ring is reduced in order from the one side as a result of the radial inward pressing force applied to the tapered surface by the tapered opening. For this reason, the diameter is not uniformly reduced with respect to the shaft hole, but the taper port of the cap nut first acts to start reducing the diameter, and tightening is not average. In other words, with the conventional configuration, the chuck ring is biased and the diameter is reduced, so the effective length necessary for preventing the water pipe from coming off becomes small. Therefore, even if the amount of tightening of the cap nut is increased, If the diameter is reduced excessively, the protrusions in the shaft hole may bite excessively and damage the tube surface.

  As another problem, in the conventional pipe joint, the joint body has a water passage sleeve, and the diameter of the chuck ring is reduced while the water pipe is inserted into the water passage sleeve. The O-ring attached to the outer surface of the water flow sleeve is mainly responsible for securing the water tightness of the water sleeve and the water flow tube. For this reason, if the diameter of the O-ring is increased to increase water tightness, the insertion resistance of the water pipe to the water passage sleeve increases and the workability is hindered. On the other hand, if priority is given to ease of insertion (workability), the O-ring There is a problem that sufficient water-tightness cannot be secured with the reduction in diameter.

  The present invention has been made in view of the above-described problems. The object of the present invention is to prevent the chuck ring from being single-clamped while uniformly reducing the diameter of the entire chuck ring to ensure a high clamping force. It is an object of the present invention to provide a pipe joint in which the biting structure is also improved to further enhance the effect of preventing the water pipe from coming off. Another object of the present invention is to obtain higher water tightness while improving workability such as inserting a water pipe and tightening a cap nut.

  In order to achieve the above-mentioned object, in the present invention, an annular space between the male screw cylinder and the water passage sleeve is formed as a insertion portion of the water pipe, and a tapered port gradually reducing in diameter is formed in the opening of the male screw cylinder. A joint body in which outwardly protruding ridges are formed on the outer circumferential surface of the water flow sleeve; a cap nut that forms a reverse tapered port opposite to the tapered port in the inner surface opening and is screwed into the male screw barrel; And a chuck ring having a taper surface corresponding to the taper port and the reverse taper port on each outer surface. According to the means described so far, both the tapered surfaces on both sides of the chuck ring are simultaneously press-fitted into the tapered port and the reverse tapered port as the cap nut is threaded. Therefore, the inner insertion hole is reduced in diameter almost uniformly over the entire length according to the tightening amount of the cap nut.

  In the present invention based on the above-mentioned means, a pair of inward ridges are formed at symmetrical positions sandwiching the outward ridges in the internal insertion hole of the chuck ring, so the outward ridges and the pair of inward By projecting the ridges, the wall of the water pipe can be deformed into a wave shape inside the chuck ring to obtain a high pull-out preventing force and at the same time improve the water tightness. Here, in the chuck ring, it is preferable that the outward ridge of the water flow sleeve is positioned between the pair of inward ridges when the cap nut is tightened.

  The taper port of the male screw cylinder and the reverse taper port of the cap nut are gradually reduced in diameter in opposite directions. However, if the same inclination angle is set in line symmetry, the press-fitting conditions of both the taper surfaces of the chuck ring As a result, the chuck ring can be reduced in diameter more uniformly.

  If the outer ridge is further sandwiched between the outer ridges and a pair of inward ridges facing each of the inward ridges of the chuck ring are formed, the chuck ring is fully tightened when the cap nut is completely tightened. Since the substantial difference in height between the inwardly protruding ridges and the outwardly protruding ridges of the water flow sleeve is increased, the water flow pipe can be deformed into a waveform having a larger height difference.

  In addition, by forming the inclined surfaces of the tapered surfaces of the chuck ring into convex curved shapes that bulge outward toward the tapered port and the reverse tapered port, the contact area between the tapered port and the reverse tapered port is reduced, and the cap nut is tightened. Torque is reduced.

  Furthermore, if the inwardly protruding ridge of the chuck ring has a trapezoidal shape with a rounded apex, the frictional resistance when inserting the water pipe can be reduced.

  The outward projecting ridge of the water flow sleeve is integrally formed when the water flow sleeve is molded, and an annular groove is provided around the outer peripheral surface of the water flow sleeve, and an O-ring is attached to the annular groove. It can be. In this case, the water tightness can be further enhanced by the O-ring.

  According to the present invention, the diameter of the chuck ring is gradually reduced from both sides thereof, and the water pipe is tightened almost uniformly, so that connection failure or damage to the pipe surface due to one-side tightening is not caused. Since the water pipe is deformed into a corrugated shape, it is possible to more reliably prevent the water pipe from coming off and to simultaneously prevent water leakage from the water contact surface with the water flow sleeve.

  In addition, when the taper port of the male screw cylinder and the reverse taper port of the cap nut have the same inclination angle in line symmetry, both sides of the chuck ring can be reduced in diameter under exactly the same conditions. It can be tightened more uniformly.

  Further, in the case where the inwardly recessed grooves are formed on the outer peripheral surface of the water flow sleeve, the water flow pipe can be deformed into a waveform having a larger height difference in the chuck ring, so that the effect of retaining and leaking water can be obtained. Increase more.

  Further, in the case where the inclined surface of the taper surface of the chuck ring is a convex curved surface, the contact area with the taper port and the reverse taper port is reduced, and the cap nut can be tightened with low torque. In the case where the inwardly protruding ridge of the chuck ring has a trapezoidal shape with a rounded round cross section, the water pipe can be easily inserted into the chuck ring, so that workability is improved.

  Furthermore, when the outwardly protruding ridge of the water flow sleeve is replaced with one having an O-ring attached to the annular groove, the water tightness of the water contact surface with the water flow sleeve can be further improved.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is an upper half sectional view of a pipe joint showing an embodiment of the present invention. A joint body 1 is provided with a male screw cylinder 3 and a water flow sleeve 4 coaxially on one side with a flange portion 2 as a boundary. While the annular space between both 3 and 4 is used as the insertion portion of the water pipe P, the opposite side is the connecting portion 5 having an arbitrary configuration. In this joint body 1, the opening of the male screw cylinder 3 is an axially reduced taper port 3 a whose inner diameter is gradually reduced toward the insertion portion. Further, in the case of this embodiment, the water passing sleeve 4 has a length that partially protrudes from the taper port 3a of the male screw barrel 3, and an outwardly protruding ridge having an annular tip round on the outer peripheral surface of the protruding portion. 4a is provided around. Furthermore, in this embodiment, as selective means in the present invention, an annular inward groove 4b is formed on the outer peripheral surface of the water passing sleeve 4 at the same distance position before and after the outward protrusion 4a (left and right in the drawing).・ A pair of 4c is provided.

  Next, the cap nut 6 has a female screw 6 a that is screwed into the male screw cylinder 3, and the inner diameter of the cap nut 6 is gradually increased toward the male screw cylinder 3 of the joint body 1 at the inner surface opening on one side thereof. A taper port 6b is formed. In other words, the reverse taper port 6 b of the cap nut 6 is reduced in diameter in the opposite direction to the taper port 3 a of the male screw barrel 3. In this embodiment, the taper port 3a and the reverse taper port 6b are formed at the same inclination angle in line symmetry.

  Subsequently, the chuck ring 7 is formed with tapered surfaces 7a and 7b whose outer dimensions gradually increase toward the center on both outer surfaces of the chuck ring 7, and the center is composed of the maximum outer diameter of the tapered surfaces 7a and 7b. The horizontal cylindrical surface 7c is used. These taper surfaces 7a and 7b correspond to the taper port 3a of the male screw cylinder 3 and the reverse taper port 6b of the cap nut 6, respectively, and the press-fit depth to the taper port 3a and the reverse taper port 6b as the cap nut 3 is screwed. This increases the diameter of the chuck ring 7 from both sides.

  The chuck ring 7 has an insertion hole 7d of the water pipe P inside, and has a substantially C-shaped cross section in which a part of the cylindrical wall is cleaved in the axial direction by a slit (not shown). The diameter of the insertion hole 7d is reduced by the narrowing deformation as before. In the case of the present invention, a pair of inwardly protruding ridges 7e and 7f are formed in the insertion hole 7d of the chuck ring 7 from the intermediate position to the equally spaced positions. Further, the projecting length of the inwardly protruding ridges 7e and 7f is set to an amount through which the water pipe P can pass before the chuck ring 7 is reduced in diameter. Further, in this embodiment, the inwardly protruding ridges 7e and 7f are formed as isosceles trapezoidal sections with rounded apex angles so that the water pipe P can be inserted easily without being caught. Any other shape can be used as long as the water pipe P can pass therethrough.

  The chuck ring 7 having the above-described configuration has the inner shape of the insertion hole 7d and the outer shape including the tapered surfaces 7a and 7b line-symmetrical in the front-rear direction (left and right in the drawing). When the pair of inwardly recessed ridges 4b and 4c are formed on the water flow sleeve 4, the distance between the pair of inwardly protruding ridges 7e and 7f is made to coincide.

  Next, with regard to the pipe joint of the present embodiment, the connection procedure of the water pipe P will be described. First, the chuck ring 4 is inserted into the water flow sleeve 4 of the joint body 1 and the cap nut 6 is inserted into the male screw cylinder 3. Tighten loosely. In this state, since the chuck ring 4 is positioned between the reverse tapered port 6b of the cap nut 6 and the tapered port 3a of the male screw cylinder 3, the diameter of the chuck ring 4 is not reduced. The insertion part of the main body 1 can be inserted.

  And the procedure from the insertion of the water pipe P to the tightening of the cap nut 6 is not different from that of the conventional pipe joint. However, in the case of the present embodiment, when the cap nut 6 is tightened, the opposite is true. The press-fit depth of the taper surfaces 7a and 7b of the chuck ring 4 with respect to the taper port 6b and the taper port 3 of the male screw cylinder 3 increases, and the chuck ring 4 is gradually reduced in diameter from both sides. Here, in this embodiment, the cap nut 6 is tightened to the limit position where it comes into contact with the flange portion 2 of the joint body 1 to complete the operation, and FIG. 1 shows this state. When this operation is completed, the chuck ring 4 has the entire diameter of the insertion hole 7d substantially uniformly reduced in diameter, and the water pipe P is uniformly tightened to the water sleeve 4, and the outward protrusion 4a of the water sleeve 4 and the chuck ring 7 are also tightened. Since the inwardly protruding ridges 7e and 7f alternately bite into the water pipe P and deform the pipe wall into a corrugated shape, a high retaining effect and water tightness are exhibited at the same time. In particular, in this embodiment, when the work is completed, the front and rear (left and right in the drawing) of the chuck ring 7 are symmetrical with respect to the outward protrusion 4a of the water flow sleeve 4 as the axis of symmetry, and the inward protrusion 7e Since 7d faces the inwardly recessed grooves 4b and 4c of the water flow sleeve 4, the amount of deformation of the water flow pipe P at this portion increases, and the corrugation is deformed into a waveform having a greater difference in height. The sex can be further enhanced.

  FIG. 2 shows a more preferable selective modification of the tapered surfaces 7a and 7b of the chuck ring 7. Here, the tapered port 3a of the male screw cylinder 3 and the one-side tapered surface 7b of the chuck ring 7 corresponding thereto. The reverse taper port 6b of the cap nut 6 and the taper surface 7a on the other side of the chuck ring 7 have the same relationship in line symmetry. And in the said embodiment, although the inclined surface was made into linear form, in this modification, the said inclined surface is made into the convex curved surface shape which swells toward an outer side. According to the modified example, the tapered surfaces 7a and 7b are press-fitted into the reverse tapered port 6b of the cap nut 6 and the tapered port 3a of the male screw cylinder 3 in a line contact state. The tightening torque can be reduced. Therefore, as long as this is realized, it is a matter of course that the convex curved surface of the present invention includes an arc or an elliptical arc.

  FIG. 3 shows a second embodiment of the present invention, in which the outwardly protruding ridge 4a of the water flow sleeve 4 is configured by attaching an O-ring R to an annular groove M. According to the second embodiment, the water tightness is further enhanced by the O-ring R.

  In the above-described embodiment, the work is completed by tightening the cap nut 6 until it comes into contact with the flange portion 2 of the joint body 1. However, in the present invention, which stage is the work completion is arbitrary. In addition, the reverse taper port 6b of the cap nut 6 and the taper port 3a of the male screw cylinder 3 can be more securely avoided from being tightened by making the inclination angles exactly the same in line symmetry as in the above embodiment. Although it is optimal because it can be done, a slight angle difference inevitable in manufacturing is within an allowable range.

Upper half sectional view of a pipe joint showing the first embodiment of the present invention The principal part expanded sectional view which showed the more preferable example of a change of the taper surface of a chuck ring Upper half sectional view of a pipe joint showing a second embodiment of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Joint body 3 Male threaded cylinder 3a Taper port 4 Water flow sleeve 4a Outward convex strip 4b, 4c Inward concave strip 6 Cap nut 6b Reverse taper port 7 Chuck ring 7a, 7b Tapered surface 7d Insertion hole 7e, 7f Inward convex Article

Claims (6)

An annular space between the male screw cylinder and the water flow sleeve is used as an insertion portion of the water pipe, and a taper port that gradually decreases in diameter is formed in the opening of the male screw cylinder, and an outwardly projecting ridge on the outer peripheral surface of the water flow sleeve A joint body formed with an inner surface, a cap nut that forms a reverse taper port opposite to the taper port on the inner surface opening and is screwed into the male screw cylinder, and a taper port and a reverse taper port on both outer surfaces. And a chuck ring having a corresponding tapered surface, and a pair of inwardly protruding ridges are formed in symmetrical positions sandwiching the outwardly protruding ridges in the internal insertion hole of the chuck ring.   The pipe joint according to claim 1, wherein the taper port and the reverse taper port have the same inclination angle in line symmetry. The pipe joint according to claim 1 or 2, wherein a pair of inward recesses are formed on the outer peripheral surface of the water flow sleeve so as to sandwich the outward protrusions and to face the inward protrusions of the chuck ring. . The pipe joint according to claim 1, 2, or 3, wherein each of the tapered surfaces of the chuck ring has a convex curved surface. The pipe joint according to any one of claims 1 to 4, wherein the inwardly protruding ridge of the chuck ring has an isosceles trapezoidal cross section with a rounded apex angle. The pipe joint according to any one of claims 1 to 5, wherein the outwardly protruding ridge of the water flow sleeve is formed by attaching an O-ring to an annular groove provided around an outer peripheral surface.

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