JP5689916B2 - Pipe fitting - Google Patents

Description

  The present invention relates to a pipe joint.

  A structure is disclosed in which a joint member is constituted by a synthetic resin tubular member and a metal outer member, and a nut portion for integrally engaging a tool is provided integrally with the outer member (see Patent Document 1).

JP 2012-37011 A

  However, in the above-described conventional example, since the nut portion is provided on the metal outer member, cutting is required, and it is difficult to suppress material costs and processing costs.

  On the other hand, a metal tube is insert-molded into a resin tube so that a nut portion (clamping portion) is made of resin. In this case, airtight performance is ensured at the contact portion between the resin and the metal. In order to reduce the cost of materials by making the pipe joint as compact as possible, the close contact portion is designed to be located at or near the radially inner side of the tightening portion.

  However, if an excessive tightening force is applied to this tightening part, the force is transmitted to an unintended vicinity, and peeling occurs not only in the close contact part in the radial direction of the tightening part but also in the close contact part in the vicinity. It is conceivable that the airtight performance is lowered.

  In view of the above-described facts, an object of the present invention is to improve the airtightness of a pipe joint that is composed of a metal pipe and a resin pipe and is provided with a tightening portion.

The invention according to claim 1 (pipe joint) is configured such that a metal tube configured to be connectable to a tube body, one end portion is configured to be connectable to another tube body, and the other end portion covers an outer periphery of the metal tube. A plurality of portions that are integrally molded with the metal tube, the other end portion is divided in the axial direction and are fitted to the metal tube, and an input portion for tightening torque is provided at a portion other than at least one of the plurality of portions. The other end is in contact with the outer periphery of the metal tube, and the thickness is thinner than the radial thickness from the outer surface of the plurality of parts to the outer periphery of the metal tube, and A thin tube portion formed by forming a groove on the outer surface is provided, and the plurality of portions have a resin pipe connected in the axial direction by the thin wall portion .

In this pipe joint, the other end portion of the resin pipe is provided with a plurality of portions that are divided in the axial direction and fitted into the metal tube, so that when the metal tube portion is connected to the pipe body, the other end portion is tightened. Even if a tightening torque is input to the part, it is difficult to transmit the torque to the vicinity. Therefore, even if peeling occurs at the close contact portion between the resin tube and the metal tube on the radially inner side of the tightening portion, the peel hardly occurs at the close contact portion in the vicinity thereof. For this reason, the airtight performance about the pipe joint comprised by the metal pipe and the resin pipe, and having provided the fastening part in the resin pipe can be improved.

Further , it is possible to suppress the transmission of the tightening torque from the tightening portion to the nearby portion while integrally molding the plurality of portions.

Furthermore, when forming a thin part in the resin tube by partially increasing the diameter of the metal tube, it is necessary to process the metal tube. In this pipe joint, since the groove is formed on the outer surface of the resin pipe to form the thin portion, the processing of the metal pipe can be reduced. For this reason, the increase in processing cost can be suppressed.

The invention of claim 2 is the pipe joint of claim 1, the radial thickness of the thin portion is 0.5 mm to 1.5 mm.

  Here, when the thickness of the thin portion in the radial direction exceeds 1.5 mm, the tightening torque is easily transmitted from the tightening portion to the vicinity thereof. Moreover, if the thickness of the thin portion in the radial direction is less than 0.5 mm, the resin hardly flows during molding.

In the pipe joint described in this embodiment, since the thickness of the thin portion is appropriately set, transmission of the tightening torque from the tightening portion to the vicinity thereof can be effectively suppressed.

According to a third aspect of the present invention, in the pipe joint according to the first or second aspect , the outer surface of the tightening portion at the other end is formed in a polygonal shape.

In this pipe joint, since the outer surface of the tightening portion at the other end is formed in a polygonal shape, it is easy to input a tightening torque to the tightening portion. For this reason, the workability | operativity at the time of connecting the part of a metal pipe to a tubular body can be improved.

  According to the pipe joint according to the present invention, it is possible to obtain an excellent effect that it is possible to enhance the airtight performance of a pipe joint that is formed of a metal pipe and a resin pipe and is provided with a tightening portion.

It is sectional drawing which shows the state which cut | disconnected a part of pipe joint in the axial direction. It is an enlarged view which shows the contact | adherence part vicinity in a pipe joint.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In FIG. 1, a pipe joint 10 according to the present embodiment includes a metal pipe 12 and a resin pipe 14.

  The metal tube 12 is configured to be connectable to the tube body 20. The metal tube 12 has a small diameter portion 16 and a large diameter portion 18. For example, knurling is performed on the outer periphery 16 </ b> A of the small-diameter portion 16 in order to improve the adhesion with the resin tube 14 (not shown). Further, for example, three grooves 16B extending in the circumferential direction are formed on the outer periphery 16A of the small diameter portion 16. The groove 16B may not be provided, and the contact portion between the resin tube 14 and the metal tube 12 may be a cylindrical surface. On the other hand, a pipe male male screw for fastening with the pipe body 20 is formed on the outer periphery 18 </ b> A of the large diameter portion 18. The pipe body 20 is various piping components in which a pipe taper female thread is formed. A plurality of grooves 18 </ b> B extending in the circumferential direction are formed on the inner periphery of the large diameter portion 18.

  The resin tube 14 is configured such that one end portion 22 can be connected to another tube body 24, and the other end portion 26 covers the outer periphery of the metal tube 12 and is integrally formed with the metal tube 12. In the illustrated example, the other end portion 26 covers the outer periphery of the small diameter portion 16 and also covers a part of the outer periphery of the large diameter portion 18. Further, the other end portion 26 includes a plurality of portions that are divided in the axial direction and fit into the metal tube 12. In the illustrated example, the other end portion 26 includes two portions. The two portions are fitting portions that are respectively fitted to, for example, the outer periphery 16 </ b> A of the small diameter portion 16 in the metal tube 12. Here, “division” is not limited to “separation”. As a material for the resin tube 14, a resin selected from PB, PEX, PPS, and PPSU is preferable, and in particular, PPS and PPSU are more preferable. However, the material is not limited to this, and these are combined. It can also be used.

The other end portion 26 is in contact with the outer periphery 16A of the small diameter portion 16 of the metal tube 12, and the thickness t is thinner than the radial thicknesses t1 and t2 from the outer surface of the two portions to the outer periphery 16A of the small diameter portion 16. A thin portion 28 is provided. The two portions are connected in the axial direction by the thin portion 28. In other words, the two portions are partitioned in the axial direction by the thin portion 28.
The thicknesses t, t1, and t2 are based on the outer periphery 16A of the small-diameter portion 16 in the radial direction, and are not based on the groove 16B. The thin portion 28 is preferably located on the outer periphery 16A of the small diameter portion 16. When the outer periphery 16 </ b> A is not smooth due to knurling or the like, the thickness t is the average thickness in the thin portion 28. When the thicknesses t1 and t2 change in the circumferential direction, the thicknesses t1 and t2 are the minimum thicknesses. The thickness t1 can be appropriately set according to the size of a tool (not shown) such as a spanner to be hung on the tightening portion 30.

  As shown in FIG. 2, the thin portion 28 is configured by forming a groove on the outer surface of the resin tube 14. In other words, in order to form the thin portion 28, a convex portion extending in the circumferential direction is not provided on the outer periphery 16 </ b> A of the small diameter portion 16 of the metal tube 12. If a convex part is not formed in the outer periphery of the surface which performs metal processing, such as knurl processing, it will become easy to perform metal processing. In the axial direction, the position of the thin portion 28 is out of the groove 16B of the small diameter portion 16. The thickness t in the radial direction of the thin portion 28 is, for example, 1.5 mm or less, and more preferably 1.0 mm or less. When the thickness t exceeds 1.5 mm, the tightening torque is easily transmitted from the tightening portion 30 to the vicinity thereof. In consideration of the ease of resin flow during molding, the thickness t is preferably 0.5 mm or more. Further, the axial length of the thin portion 28 is preferably 0.5 mm to 2 mm. If it is less than 0.5 mm, the tightening torque is easily transmitted, and if it exceeds 2 mm, the resin may not flow easily during molding.

  A tightening portion 30 serving as a tightening torque input portion is provided in a portion excluding at least one of the plurality of portions. In the axial direction, the tightening portion 30 is formed on the side close to the large diameter portion 18 of the metal tube 18. Thus, when a tool (not shown) such as a spanner is applied to the tightening portion 30, it does not interfere with the resin cap 34. A portion far from the large diameter portion 18 is a cylindrical general portion 32. That is, in the illustrated example, the tightening portion 30 is provided in a portion of the two portions excluding the general portion 32. The outer surface of the fastening part 30 in the other end part 26 is formed in, for example, a polygonal shape. The polygon is, for example, a hexagon or an octagon, and is a hexagon in the illustrated example. In order to make it easy to put a tool (not shown) such as a spanner on the tightening portion 30, it is desirable that the two-side width in the diameter direction of the tightening portion 30 be equal to or larger than the outer diameter of the general portion 32.

  For example, a mechanism for completing the connection only by inserting the tube body 24 is incorporated in the one end portion 22 of the resin tube 14, and this portion is covered with a resin cap 34. An O-ring 38 is attached to the groove formed on the outer periphery of the one end portion 22. Thereby, the watertightness between the pipe bodies 24 and airtightness are ensured.

  The resin constituting the resin pipe 14 also covers the inner periphery of the metal pipe 12, and the fluid flowing through the pipe joint 10 passes through the inside of the resin pipe 14. The resin enters the groove 16B of the small diameter portion 16 and the groove 18B of the large diameter portion 18 of the metal tube 12 and is engaged in the axial direction during insert molding. Thereby, the intensity | strength of the axial direction of the pipe joint 10 is raised.

(Function)
This embodiment is configured as described above, and the operation thereof will be described below. 1 and 2, in the pipe joint 10 according to the present embodiment, the other end portion 26 of the resin pipe 14 includes a plurality of portions that are divided in the axial direction and fit into the metal tube 12, and the plurality of portions are thin. Since the portion 28 is connected in the axial direction, even when a tightening torque is input to the tightening portion 30 of the other end portion 26 when the metal tube 12 portion is connected to the tube body 20, It is difficult for torque to be transmitted to a general part 32. In particular, since the thickness t of the thin portion 28 is appropriately set to 0.5 mm to 1.5 mm, transmission of the tightening torque from the tightening portion 30 to the vicinity thereof can be effectively suppressed.

  Therefore, even if peeling occurs at the close contact portion between the resin tube 14 and the metal tube 12 on the radially inner side of the tightening portion 30, peeling does not easily occur at the close contact portion of the general portion 32 that is the vicinity thereof. Even if the gas 36 enters the boundary between the inner periphery of the metal tube 12 and the resin in the direction of arrow A, it is difficult for the gas 36 to pass through the close contact portion of the general portion 32. For this reason, the airtight performance about the pipe joint comprised by the metal pipe 12 and the resin pipe 14, and having provided the fastening part 30 in the resin pipe 14 can be improved.

  Further, since the outer surface of the tightening portion 30 at the other end portion 26 is formed in a polygonal shape, it is easy to input a tightening torque to the tightening portion 30. For this reason, the workability | operativity at the time of connecting the part of the metal pipe 12 to the pipe body 20 can be improved.

  When the thin portion 28 is formed in the resin tube 14 by partially increasing the diameter of the metal tube 12, the metal tube 12 needs to be processed. However, in the pipe joint 10 according to the present embodiment, since the thin portion 28 is formed by forming a groove on the outer surface of the resin pipe 14, the processing of the metal pipe 12 can be reduced. For this reason, the increase in processing cost can be suppressed.

[Other Embodiments]
The other end 26 of the resin tube 14 may be composed of three or more parts. In this case, at least one part may be the general part 32 and the fastening part 30 may be provided in the remaining part. Further, the tightening portion 30 may be provided in one portion, and the remaining portion may be the general portion 32. A plurality of portions in the other end portion 26 may be separated in the axial direction without being connected by the thin portion 28.

  The tightening portion 30 may be provided over a plurality of portions. Although the outer surface of the tightening portion 30 is formed in a polygonal shape, the shape of the outer surface is not limited to this, and for example, a pair of planes arranged symmetrically with respect to a point may be provided on the cylindrical outer surface. Good.

  Although the thin portion 28 is configured by forming a groove on the outer surface of the resin tube 14, the thin portion 28 is not limited to this and may be configured by a plurality of retaining holes opened on the outer surface. Moreover, although the thin part 28 shall be formed continuously in the circumferential direction, it is not restricted to this, You may form intermittently. Although the thickness t in the radial direction of the thin portion 28 is 0.5 mm to 1.5 mm, the thickness t is not limited to this.

[Test example]
About the pipe joint which concerns on Examples 1-3 and a comparative example, the airtightness test was done. As shown in Table 1, the thickness t in the radial direction of the thin portion was set to four types. The test method is to hang a tool on a hexagonal tightening portion and apply torque to the resin tube until the corner of the tightening portion is deformed and the tool slides. And the thing with which airtightness was ensured between the other end part of a resin pipe and the small diameter part of a metal pipe was set as (circle), and the thing from which airtightness was lost was set as x.

  As a result, as shown in Table 1, it was confirmed that airtightness was ensured for Examples 1 to 3 in which the thickness t in the radial direction of the thin portion was 0.5 to 1.5 mm.

10 pipe joint, 12 metal pipe, 14 resin pipe, 16A outer circumference, 18 metal pipe, 18A outer circumference, 20 pipe body, 22 one end part, 24 pipe body, 26 other end part, 28 thin part, 30 tightening part, t thickness , T1 thickness, t2 thickness

Claims (3)

A metal tube configured to be connectable to the tube;
One end is configured to be connectable to another tube, the other end covers the outer periphery of the metal tube and is integrally molded with the metal tube, and the other end is divided in the axial direction and fitted to the metal tube A tightening portion serving as an input portion of tightening torque is provided at a portion excluding at least one of the plurality of portions, and the other end portion is in contact with the outer periphery of the metal tube and has a thickness. Is provided with a thin portion that is thinner than a radial thickness from an outer surface of the plurality of portions to an outer periphery of the metal tube and is formed by forming a groove on the outer surface, and the plurality of portions are thinned. a resin tube connected axially in parts,
Pipe fittings with The pipe joint according to claim 1 , wherein a thickness of the thin portion in a radial direction is 0.5 mm to 1.5 mm. The pipe joint according to claim 1 or 2 , wherein an outer surface of the tightening portion at the other end is formed in a polygonal shape.

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