JP5818855B2 - Pipe fitting - Google Patents

Description

  The present invention relates to a pipe joint.

Pipe joints are used when connecting pipes to equipment nipples and the like. There exists a union joint as this pipe joint (for example, refer patent document 1). The union joint includes a cylindrical core material connected to the nipple and a cap nut for fixing the core material to the nipple.
The union joint is tightened with a union nut on the male thread of the nipple, so that the inner flange of the cap nut presses the outer flange of the core toward the nipple, and the outer flange is clamped and fixed between the inner flange and the nipple. The
A side wall surface orthogonal to the axial direction is provided on the inner flange side of the outer flange, and a side wall surface facing the side wall surface of the outer flange is provided on the outer flange side of the inner flange, and the cap nut is tightened. At this time, the pressing force from the side wall surface of the inner flange is received by the side wall surface of the outer flange.

Japanese Patent Laid-Open No. 2005-114001

By the way, since the outer flange of the union joint is clamped and fixed between the inner flange and the nipple of the cap nut, when an external force in a direction crossing the axial direction acts on the core material, stress is applied to the corner of the outer flange. concentrate. When the core material is a synthetic resin, it is better to suppress stress concentration as much as possible in consideration of durability.
In order to suppress this stress concentration, it is generally considered to form an arc surface at the corner of the outer flange. However, if the arc surface is enlarged in consideration of stress concentration, the side wall surface of the outer flange that receives the pressing force from the inner flange tends to be smaller, and the contact area between the inner flange and the outer flange becomes smaller, so Since the pressing force concentrates on the part, the axial strength of the outer flange is reduced.
Although it is conceivable to increase the size of the outer flange and cap nut in order to secure the contact area between the inner flange and the outer flange, the size of the joint increases and the cost also increases. Further, when the diameter of the core material is reduced in order to secure the contact area between the inner flange and the outer flange, the inner diameter of the core material is reduced, resulting in a decrease in flow rate.

  In consideration of the above facts, the present invention provides a pipe joint that can secure the strength of the outer flange in the axial direction even when an inclined surface that suppresses stress concentration is formed at the corner of the outer flange formed in the core. The purpose is to provide.

The pipe joint according to claim 1 is formed in a cylindrical shape, a synthetic resin core material having a tubular body connected to one end portion in the longitudinal direction, and the other end portion of the core material. An annular outer flange extending toward the outer flange, and formed on the outer flange, provided at a corner of the core and the outer flange, and viewed from a cross section along the axial direction with respect to the outer peripheral surface of the core look including a first inclined surface which is inclined, the abutting face the first inclined surface is recessed circular surface of radius of curvature r1, cylindrical portion internally threaded portion is formed, radially from an end portion of said tubular portion An inner flange that protrudes inward and has a hole through which the core material is inserted; a second inclined surface that is formed at a corner of the inner flange and contacts the first inclined surface; and the second inclined surface There wherein a contact surface and a convex arcuate surface of a radius of curvature r2 of contact, the contact surface being set to r1 = r2, the Has a bag nut was example, the.

  In the pipe joint according to claim 1, for example, an annular seal member is disposed between the nipple and the outer flange formed on the core member, and the female thread portion of the cap nut is screwed into the male thread portion of the nipple and tightened. By connecting the pipe body to the connecting portion provided in the core material, the pipe body and the nipple can be connected to each other.

Further, a contact surface including a first inclined surface provided at a corner portion of the outer flange is formed on the outer flange of the joint body, and an inner flange of the cap nut is formed on the first inclined surface of the outer flange. Since the abutted surface that abuts against the abutment surface of the outer flange is provided including the abutting second inclined surface, the contact area between the inner flange and the outer flange when the cap nut is tightened is increased. Can take. For this reason, the stress concentration generated at the corners of the outer flange is suppressed, the strength in the direction orthogonal to the axial direction of the core material is secured, and the strength in the axial direction of the outer flange can be secured.
Furthermore, in the pipe joint according to claim 1, since the first inclined surface is a concave arc surface having a radius of curvature r1, the second inclined surface is a convex arc surface having a radius of curvature r2, and r1 = r2 is set. The first inclined surface that is the concave arc surface and the second inclined surface that is the convex arc surface can be brought into full contact with each other reliably.

  According to a second aspect of the present invention, in the pipe joint according to the first aspect, the first dimension relative to the radial dimension H of the outer flange along the radial direction from the outer peripheral surface of the core member to the outer peripheral surface of the outer flange. The radial dimension h of the inclined surface 1 is set to 40% or more.

  In the pipe joint according to claim 2, the radial dimension h of the first inclined surface with respect to the radial dimension H of the outer flange along the radial direction from the outer peripheral surface of the core material to the outer peripheral surface of the outer flange is 40% or more. Therefore, it is possible to effectively suppress stress concentration when an external force in a direction intersecting the axis is applied to the core material.

According to a third aspect of the present invention, in the pipe joint according to the first or second aspect, the contact surface includes a first side wall surface orthogonal to the outer peripheral surface of the core member, and the covered surface. The contact surface includes a second sidewall surface that contacts the first sidewall surface.

In the pipe joint according to claim 3 , the contact surface includes a first side wall surface orthogonal to the outer peripheral surface of the core member, and a first inclined surface formed as a concave arc surface, The surface includes a second side wall surface that comes into contact with the first side wall surface, and a second inclined surface that comes into contact with the first inclined surface.
Therefore, the first inclined surface and the second inclined surface can be brought into contact with each other, and the first side wall surface and the second side wall surface can be brought into contact with each other.

  As described above, according to the pipe joint of the present invention, the axial strength of the outer flange can be increased even when the inclined surface that suppresses stress concentration is formed at the corner of the outer flange formed in the core material. Can be secured.

It is sectional drawing along the axis which shows the pipe joint which concerns on one Embodiment of this invention. (A) is an enlarged sectional view along the axis showing a state where the inner flange of the cap nut and the outer flange of the core material are in contact, and (B) is a separation between the inner flange of the cap nut and the outer flange of the core material. It is an expanded sectional view along the axis which shows the state which carried out. It is sectional drawing along the axis which shows the state which connected the resin pipe and the nipple to the pipe joint which concerns on one Embodiment of this invention. It is sectional drawing along the axis line which shows the contact surface and to-be-contacted surface of the pipe joint which concerns on 2nd Embodiment. It is sectional drawing along the axis line which shows the contact surface and to-be-contacted surface of the pipe joint which concerns on 3rd Embodiment.

[First Embodiment]
A pipe joint 10 according to a first embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the pipe joint 10 of the present embodiment includes a joint body 12 and a cap nut 54.
(Fitting body)
The joint body 12 includes a core member 14, a sleeve 16, an intermediate ring 18, an engagement release member 20, an O-ring 22 as a water stop member, and a lock ring 24, and these members are arranged so that their central axes coincide with each other. Has been. In the present embodiment, the core material 14, the sleeve 16, the intermediate ring 18, and the disengagement member 20 are synthetic resin molded products.

The core material 14 is a core portion 26 that can be inserted into the resin pipe P to be connected on the arrow L direction side. A pair of fitting insertion grooves 28 are formed on the outer peripheral surface of the core portion 26, and O-rings 22 are fitted in these fitting insertion grooves 28, respectively. When the core portion 26 is inserted into the resin tube P, the O-ring 22 is in close contact with the inner peripheral surface of the resin tube P and seals between the resin tube P and the core material 14.
The arrow R direction side of the core member 14 is a large-diameter portion 30 formed larger in diameter than the core portion 26, and a groove 32 is formed in the large-diameter portion 30 in the vicinity of the boundary with the core portion 26. ing.

The intermediate ring 18 is disposed outside the outer peripheral surface of the core member 14 on the arrow L direction side.
An end of the intermediate ring 18 on the arrow R direction side enters and fits into the groove 32 of the core member 14, whereby the intermediate ring 18 is fixed to the core member 14.
The hollow cylindrical insertion portion 34 surrounded by the inner peripheral surface of the intermediate ring 18, the outer peripheral surface of the core portion 26, and the end portion of the large-diameter portion 30 is set to a size that allows the end portion of the resin tube P to be inserted with a certain size. Has been.

On the outer peripheral surface of the intermediate ring 18 on the arrow R direction side, an uneven sleeve engaging portion 36 is formed.
The sleeve 16 has a substantially cylindrical shape, and is disposed outside the outer peripheral surface of the intermediate ring 18 on the arrow L direction side.
On the inner peripheral surface of the sleeve 16, an uneven engagement portion 38 that can be fitted to the sleeve engagement portion 36 is formed on the arrow L direction side. The sleeve engaging portion 36 is fitted to the engaged portion 38 and the intermediate ring 18 is fixed to the sleeve 16.
On the side of arrow L in the direction of arrow L from the engaged portion 38 of the sleeve 16, an inclined portion 40 whose inner diameter decreases as it goes in the direction of arrow L, a first constant diameter portion 42 having a constant inner diameter, and a first constant diameter portion 42. The second constant diameter portion 44 having an inner diameter smaller than the inner diameter is sequentially formed.

  The lock ring 24 is disposed on the inner peripheral side of the inclined portion 40 of the sleeve 16 and between the intermediate ring 18 and an engagement release member 20 described later. The lock ring 24 is provided with a plurality of elastically deformable claw portions 24A projecting toward the inner peripheral side at intervals in the circumferential direction, and the diameter of an imaginary circle passing through the tip of the claw portion 24A is outside the resin tube P. The diameter is set slightly smaller than the diameter.

The disengagement member 20 has a substantially cylindrical shape whose inner diameter is slightly larger than the outer diameter of the resin pipe P, and is disposed on the inner peripheral side of the sleeve 16 so as to be movable along the central axis K1. The disengagement member 20 includes a pressing inclined portion 46 for pressing the claw portion 24A on the arrow R direction side, and a constant outer diameter portion 48 on the arrow L direction side of the pressing inclined portion 46.
The constant outer diameter portion 48 of the disengagement member 20 is smaller in diameter than the first constant diameter portion 42 of the sleeve 16 and the second constant diameter portion 44 so that the disengagement member 20 does not come off the sleeve 16. It is formed in a larger diameter than.

As shown in FIGS. 1 and 2, an annular outer flange 50 extending outward in the radial direction is formed at the end in the arrow R direction of the large-diameter portion 30 of the core member 14.
As shown in FIG. 2B, a first inclined surface 52 is formed at a corner (base portion of the outer flange 50) formed by the outer peripheral surface of the large diameter portion 30 and the first side wall surface 51 of the outer flange 50. Is formed.
The first side wall surface 51 of the present embodiment is orthogonal to the axis of the core material 14 when viewed in a cross section along the axial direction of the core material 14. The first inclined surface 52 has a concave arc shape with a radius r <b> 1 having a center of curvature on the radially outer side of the large diameter portion 30 when viewed in a cross section along the axial direction of the core member 14. Are smoothly connected to the outer peripheral surface and the first side wall surface 51.
In addition, the 1st side wall surface 51 and the 1st inclined surface 52 of this embodiment are equivalent to the contact surface of this invention.

(Cap nut)
As shown in FIGS. 1 and 2, the cap nut 54 is formed of a hexagonal columnar metal member. A first hole 56 is formed in the axial center from the end on the arrow R direction side toward the arrow L direction side, and the first hole 56 has a smaller diameter than the first hole 56 on the arrow L direction side. A second hole 58 is formed. An internal thread 62 is formed in the first hole 56 from the end on the arrow R direction side toward the hole bottom.

  The inner diameter of the first hole 56 is set to a dimension in which the outer flange 50 of the core member 14 can be inserted. On the other hand, the inner diameter of the second hole 58 is set to be smaller than the outer diameter of the outer flange 50 of the core member 14 and slightly larger than the outer diameter of the large-diameter portion 30 of the core member 14. Thereby, the cap nut 54 is rotatable relative to the core member 14 and is movable in the axial direction.

An annular inner flange 60 extending radially inward from the inner surface of the first hole 56 is formed between the end of the cap nut 54 on the arrow L direction side and the bottom of the first hole 56.
The second side wall surface 61 on the first hole 56 side (arrow R direction side) of the inner flange 60 is orthogonal to the axis of the cap nut 54 when viewed in a cross section along the axial direction of the cap nut 54. The first side wall surface 51 of the outer flange 50 can be opposed to the first side wall surface 51.

A second inclined surface 64 facing the first inclined surface 52 formed on the core member 14 of the joint body 12 is formed at the inner corner of the inner flange 60 on the first hole 56 side (arrow R direction side). Is formed. The second inclined surface 64 has a convex arc shape with a radius r2 having a center of curvature on the radially inner side of the inner flange 60 when viewed in a cross section along the axial direction. In the present embodiment, the radius r1 of the first inclined surface 52 and the radius r2 of the second inclined surface 64 are set to the same dimension.
In addition, the 2nd side wall surface 61 and the 2nd inclined surface 64 of this embodiment are equivalent to the to-be-contacted surface of this invention.

  Accordingly, the second side wall surface 61 of the inner flange 60 and the first side wall surface 51 of the outer flange 50 are brought into contact with each other, and the second inclined surface 64 of the inner flange 60 and the first inclination of the outer flange 50 are brought into contact with each other. The surface 52 can be brought into contact.

(Function, effect)
Next, the usage method of the pipe joint 10 of this embodiment is demonstrated.
First, a connection procedure between the pipe joint 10 and the nipple 66 as one connection partner will be described.
As shown in FIG. 1, an annular seal 68 is disposed between the outer flange 50 of the core member 14 of the pipe joint 10 and the nipple 66, and the female screw 62 of the cap nut 54 is screwed to the male screw 70 of the nipple 66. Tighten the cap nut 54.

By tightening the cap nut 54, the pipe joint 10 is connected to the nipple 66, and the outer flange 50 and the seal 68 are sandwiched between the inner flange 60 and the nipple 66 as shown in FIG. 2.
Accordingly, the second side wall surface 61 of the inner flange 60 abuts on the first side wall surface 51 of the outer flange 50, and the second inclined surface 64 of the inner flange 60 is in contact with the first inclined surface 52 of the outer flange 50. Abut.

In the pipe joint 10 of the present embodiment, since the arc-shaped first inclined surface 52 is formed at the corner formed by the outer peripheral surface of the large diameter portion 30 and the first side wall surface 51 of the outer flange 50, the core material 14 On the other hand, it is possible to suppress the stress concentration generated in the corner when a force in a direction crossing the axial direction is applied.
The force in the direction intersecting the axial direction refers to an external force when, for example, a spanner that is tightening the cap nut 54 of another adjacent pipe joint 10 is hit, but the resin pipe P is pulled. Other external forces such as an external force acting when applied can be used.
In order to effectively suppress the stress concentration, the outer flange 50 measured along the radial direction from the outer peripheral surface of the large-diameter portion 30 to the outer peripheral surface of the outer flange 50 as shown in FIG. It is preferable that h is 40% or more of H, where H is the height dimension of H and the radial dimension of the first inclined surface 52 that is measured along the radial direction is h.

Further, in the pipe joint 10 of the present embodiment, the second inclined surface 64 of the inner flange 60 is brought into contact with the first inclined surface 52 of the outer flange 50, and the inner wall is in contact with the first side wall surface 51 of the outer flange 50. Since the second side wall surface 61 of the flange 60 is brought into contact, the contact area between the outer flange 50 and the inner flange 60 can be increased.
For this reason, the first inclined surface 52 is formed at the corner of the outer flange 50, but when the cap nut 54 is tightened, the pressing force of the inner flange 60 over the entire side of the outer flange 50 on the inner flange side. Since the pressing force is not concentrated on a part of the outer flange 50, the axial strength of the outer flange can be ensured.

  In the pipe joint 10 of the present embodiment, since the first inclined surface 52 and the second inclined surface 64 have a simple arc shape, the first inclined surface 52 and the second inclined surface 64 can be easily formed. The dimensional stability of the first inclined surface 52 and the second inclined surface 64 is also good, and the first inclined surface 52 and the second inclined surface 64 can be reliably brought into contact with each other.

Finally, a connection procedure between the pipe joint 10 and the resin pipe P which is the other connection partner will be described.
The resin pipe P is inserted into the insertion part 34 of the joint body 12, and the end of the resin pipe P is abutted against the end of the large diameter part 30. By inserting the resin tube P into the insertion portion 34, the claw portion 24A of the lock ring 24 is pushed and expanded by the resin tube P, and the tip end portion of the claw portion 24A is caught on the outer peripheral surface of the resin tube P. Is prevented, and the resin pipe P is securely connected to the pipe joint 10. When the resin pipe P is connected to the joint body 12, the O-ring 22 of the core material 14 is in close contact with the inner peripheral surface of the resin pipe P, so that the sealing performance between the resin pipe P and the core material 14 is ensured. Is done.

[ First Reference Example ]
Next, the pipe joint 10 according to the first reference example will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same structure as 1st Embodiment, and the description is abbreviate | omitted.
In the first embodiment, the first inclined surface 52 has a concave arc shape with a radius r1 having a center of curvature on the radially outer side of the large-diameter portion 30, but in this reference example, as shown in FIG. It is a linear inclined surface that is inclined at a constant angle with respect to the outer peripheral surface of the large-diameter portion 30 and the first sidewall surface 51. In this case, the second inclined surface 64 of the cap nut 54 has a shape that comes into contact with the first inclined surface 52.

[ Second Reference Example ]
Next, the pipe joint 10 according to the second reference example will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same structure as 1st Embodiment, and the description is abbreviate | omitted.
As shown in FIG. 5, the first inclined surface 52 may include an arcuate surface 52A and a linear inclined surface 52B inclined at a constant angle. Also in this case, the second inclined surface 64 of the cap nut 54 has a shape that comes into contact with the first inclined surface 52 including the arc surface 52A and the inclined surface 52B.
Although not shown, the first inclined surface 52 may be a curved shape formed by connecting a plurality of concave arc shapes having different curvature radii, and a plurality of linear inclined surfaces having different inclination angles (each of which is constant). (Angle) may be combined.

(Other embodiments)
The embodiments of the present invention have been described with reference to the embodiments. However, these embodiments are merely examples, and various modifications can be made without departing from the scope of the present invention. It goes without saying that the scope of rights of the present invention is not limited to these embodiments.

  In the said embodiment, although the 1st side wall surface 51 and the 1st inclined surface 52 were formed in the inner flange side of the outer flange 50 of the core material 14, this invention is not restricted to this, The inner side of the outer flange 50 There may be no first side wall surface 51 perpendicular to the axial direction on the flange side, and the inner flange side may be the first inclined surface 52. In this case, the inner flange 60 of the cap nut 54 has the second inclined surface 64 on the outer flange side.

  In the above embodiment, the radius r1 of the first inclined surface 52 and the radius r2 of the second inclined surface 64 are matched, but when the cap nut 54 is tightened, the first inclined surface 52 and the second inclined surface 52 are The radius r1 and the radius r2 do not have to be completely coincident with each other because of the manufacturing error or the like.

10 pipe joint, 12 joint body, 14 core material, 16 sleeve (connection part), 18 intermediate ring (connection part), 22 O-ring (connection part), 24 lock ring (connection part), 26 core part (connection part) , 50 outer flange, 51 first side wall surface (contact surface), 52 first inclined surface (contact surface), 54 cap nut, 56 first hole, 58 second hole, 60 inner flange, 61 Second side wall surface (contacted surface), 62 female thread, 64 Second inclined surface (contacted surface)

Claims (3)

A synthetic resin core material that is formed in a cylindrical shape and has a tubular body connected to one end in the longitudinal direction;
An annular outer flange formed on the other end of the core material and extending radially outward;
A first inclined surface formed on the outer flange and provided at a corner of the core and the outer flange and inclined with respect to the outer peripheral surface of the core when viewed in a cross section along the axial direction. A contact surface in which the first inclined surface is a concave arc surface having a radius of curvature r1 ,
A cylindrical portion formed with an internal thread portion, an inner flange that protrudes radially inward from an end portion of the cylindrical portion, and has a hole through which the core material is inserted, and is formed at a corner portion of the inner flange and the first slope A second inclined surface that contacts the surface, and the second inclined surface is a convex arc surface having a radius of curvature r2 that contacts the contact surface, and a contacted surface that is set to r1 = r2. A provided cap nut,
Pipe fittings with   The radial dimension h of the first inclined surface with respect to the radial dimension H of the outer flange along the radial direction from the outer peripheral surface of the core material to the outer peripheral surface of the outer flange is set to 40% or more; The pipe joint according to claim 1. The contact surface includes a first side wall surface orthogonal to the outer peripheral surface of the core member,
The pipe joint according to claim 1 or 2, wherein the abutted surface includes a second side wall surface that abuts on the first side wall surface.

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