WO2017072886A1 - Resin piping member, resin pipe joint, and piping production method - Google Patents

Abstract

This resin piping member (1) comprises: a pipe main body part (2) that has an internal flow path (P) that allows a fluid to flow; and two or more weld end parts (3a, 3b, 3c) that are respectively provided to two or more open sections (A1, A2, A3) of the internal flow path (P) and that are to abut and be welded to end parts of other resin piping members. At least one of the weld end parts (3a, 3b, 3c) is provided with an expanded-inner-diameter section (4) that has a larger inner diameter than the pipe main body part (2). An inner surface of the expanded-inner-diameter section (4) comprises inclined surfaces (5a, 5b) that are inclined with respect to a plane that is orthogonal to the center axis (C) of the internal flow path (P) at the location of the weld end part (3a, 3b, 3c) and are configured such that the inclination angle (θ1, θ2) of the inner surface with respect to the plane changes along the axial direction of the internal flow path (P).

Description

Resin piping member, resin pipe joint, and manufacturing method of piping

The present invention is provided in each of a tube main body portion having an internal flow path for allowing fluid to flow and two or more opening portions of the internal flow path, and is brought into contact with and welded to an end portion of another resin piping member. In particular, the present invention relates to a resin pipe member having two or more welded end parts, a resin pipe joint, and a method for manufacturing a pipe, and in particular, a resin pipe member is welded to another resin pipe member at an end part. The present invention proposes a technique that can effectively suppress the so-called inner bead that may be generated when the above is performed.

Pipes such as chemical transport lines used in various industries, using welding machines, resin pipe fittings such as resin pipe joints and resin tube members made of thermoplastic resin, and other resin pipe members In some cases, the respective end portions of the butt are brought into contact with each other and welded together.

More specifically, for example, the resin pipes are arranged so that the end portions of the resin pipe members and the end portions of the other resin pipe members face each other in each of the clamp jigs forming a pair of welding machines. Each of the member and the other resin piping member is held.
Next, both ends of the resin piping member and other resin piping members held by the clamp jig are heated by a heater or other heating device to melt those ends, and in that state, the resin piping member A piping member and other resin piping members are brought close to each other, and their end portions are brought into contact and welded by the action of a required pressure.

In this way, when the resin piping member and another resin piping member are abutted and welded at the end portions, melting is performed by pressing the end portions in a molten state by the action of a predetermined pressure. Due to the flow of the resin, at the welded portion between the resin piping member and the other resin piping member, the resin hardens in a state of rising from the inner surface to the inner peripheral side, and a raised portion can be formed on the inner surface. It has been known. Such ridges are sometimes referred to as inner beads.
In this case, in the inner bead formed on the inner surface of the welded portion of the pipe, there is a problem that when the liquid flows, a liquid pool is generated and the flow rate is reduced.

In order to solve this problem, Patent Document 1 states that “the end portions of the first and second synthetic resin tubular members are heated and melted, and then the end surfaces are butted and welded. A method of welding synthetic resin tubular members characterized by applying an internal pressure to the members has been proposed. And, according to this method, “the convexity of the inner surface of the bead part existing in the abutting part can be reduced, and by using the tubular member thus obtained for the pipe, the joint part can smoothly flow the liquid. It is not hindered, and it is also possible to prevent the junction from becoming a puddle and increasing the time required to replace the liquid. "
Furthermore, Patent Document 1 discloses that in the above-described method, “the chamfered inner diameter portions of the butted ends of both tubular members before heating” are disclosed.

JP 2004-284048 A

In patent document 1, before heating the edge part of a synthetic resin tubular member, as chamfering given to the edge part of a tubular member, specifically, each of Drawing 5 (a) and (b) of patent document 1 is shown, respectively. As shown in the figure, the end surface of the tubular member is a conical chamfer that is a surface that is linearly inclined with respect to a plane orthogonal to the central axis in the illustrated cross section, and the end surface of the tubular member is the central axis. It is disclosed that chamfering is performed to form a surface composed of an outer peripheral portion parallel to a plane orthogonal to the inner surface and an inner peripheral portion inclined linearly with respect to the plane.
However, in such chamfering disclosed in Patent Document 1, when the end portions of the tubular members are brought into contact with each other and welded, it is possible to sufficiently suppress the flow of the molten resin toward the inner peripheral side at the end portions in contact. As a result, the generation of the inner bead could not be reliably prevented.

In addition, in the welding method disclosed in Patent Document 1, since it is necessary to provide a pressurizing means for introducing nitrogen gas in order to apply an internal pressure to both tubular members at the time of matching, in addition to the increase in equipment cost, When a plurality of synthetic resin tubular members are sequentially connected to form a pipe, the above-described pressurizing means must be provided each time the ends of the tubular members are welded, and the pipe manufacturing efficiency is improved. The decline cannot be denied.

The present invention has an object to solve such problems of the prior art, and the object of the present invention is to connect a resin pipe member to another resin pipe without using special equipment. An object of the present invention is to provide a resin pipe member, a resin pipe joint, and a pipe manufacturing method capable of effectively suppressing an inner bead that may be generated in the welded part when welding the member and the end part.

The resin piping member of the present invention is provided in each of a pipe main body portion having an internal flow path for flowing a fluid and two or more opening portions of the internal flow path, and is an end portion of another resin piping member. Two or more welding end portions that are welded in contact with each other, wherein at least one of the welding end portions is provided with an inner diameter enlarged portion having an inner diameter larger than that of the tube main body portion, and the inner diameter The inner surface of the enlarged portion is inclined with respect to a plane orthogonal to the central axis of the internal flow path at the position of the welding end, and the inclined angle with respect to the plane changes in the middle of the axial direction of the internal flow path It will be.

The inner surface of the inner diameter enlarged portion has an outer inclined surface that is inclined with respect to a plane perpendicular to the central axis of the internal flow path at the position of the welding end, and the central axis is closer to the central axis than the outer inclined surface. It is preferable to have an inner inclined surface that is inclined at a larger angle than the outer inclined surface with respect to an orthogonal plane.

In this case, it is preferable that each of the inner inclined surface and the outer inclined surface is a linear tapered surface that forms a straight line in a longitudinal section along the central axis.
Here, the outer inclined surface is preferably inclined at 3 ° to 20 ° with respect to a plane perpendicular to the central axis of the internal flow path at the position of the welding end.
Here, it is preferable that the inner inclined surface is inclined at 30 ° to 60 ° with respect to a plane perpendicular to the central axis of the internal flow path at the position of the welding end.

The outer surface of the inner diameter enlarged portion can be a straight section parallel to the central axis of the internal flow path in a longitudinal section along the central axis.
The resin pipe joint of the present invention comprises any one of the above resin pipe members.

Further, the pipe manufacturing method of the present invention is a method of manufacturing a pipe by connecting a plurality of resin pipe members, and in connecting two resin pipe members to each other, At least one resin piping member of the resin piping members is any one of the resin piping members described above, and the welding end portions of the two resin piping members are heated and melted, and then The welding end portions are brought into contact with each other to be welded.
In this manufacturing method, it is preferable that the inner diameters of the welded portions of the two resin piping members connected to each other by welding the welded end portions are equal to the inner diameters of the portions adjacent to the welded portions.

According to this invention, the inner diameter enlarged portion is provided at the welding end portion of the resin piping member, and the inner surface of the inner diameter enlarged portion is inclined with respect to a plane orthogonal to the central axis of the internal flow path at the position of the welding end portion, In addition, when the resin piping member is abutted with another resin piping member at the end portion and welded by the inclined surface whose inclination angle with respect to the plane changes in the middle of the axial direction of the internal flow path, the abutting The flow of the resin to the inner peripheral side at the end portion can be effectively suppressed, and the occurrence of the inner bead at the weld portion can be reliably prevented after the end portion is welded.

It is a perspective view which shows one Embodiment of the resin-made piping members of this invention. It is a longitudinal cross-sectional view in alignment with the central axis of an internal flow path of the resin piping members of FIG. It is a longitudinal cross-sectional view which expands and shows the welding edge part of the resin-made piping members of FIG. FIG. 3 is a schematic vertical cross-sectional view showing an enlarged welded portion when the resin piping member of FIG. 1 is welded to another resin piping member at an end portion. It is a longitudinal cross-sectional view which shows the modification of a welding edge part. It is a longitudinal cross-sectional view which shows other embodiment of the resin-made piping members of this invention along the center axis line of an internal flow path. It is a longitudinal cross-sectional view in alignment with the central axis of an internal flow path which shows other embodiment of the resin-made piping members of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
A resin pipe member 1 illustrated in FIGS. 1 and 2 is an embodiment in which the present invention is applied to a resin pipe joint, and a pipe main body portion having an internal flow path P having a T shape in a longitudinal section shown in FIG. 2 and welding end portions 3a to 3c provided in each of the three opening portions A1 to A3 of the internal flow path.

Here, the welding end portions 3a to 3c of the resin piping member 1 are made of a resin tube such as a straight tube or a curved tube using a welding machine (not shown) when a pipe including the resin piping member 1 is formed. It is welded in contact with the end of another resin pipe member such as a member or another resin pipe joint. This welding is performed, for example, in such a manner that the end portions of the resin piping member 1 and the end portions of the other resin piping members are opposed to each other of the clamp jigs forming a pair of welding machines. Each of the member 1 and other resin piping members is held, and then both ends of the resin piping member 1 and other resin piping members held by the clamp jig are heated by a heater or other heating device. In a melted state, the resin piping member 1 and another resin piping member can be brought close to each other and their end portions can be brought into contact with each other by the action of a required pressure. The welding end portions 3a to 3c can be given a thickness of 1 mm or more as a welding allowance.

Also, here, the internal flow path P of the resin piping member 1 allows a liquid such as a chemical solution or a gas or other fluid to flow, for example, when the piping using the resin piping member 1 is used. Function to send to. The internal flow path P in this embodiment includes a base portion that linearly extends in the left-right direction in FIG. 2 and a branch portion that branches vertically from the base portion (in the vertical direction in FIG. 2) at the center of the base portion in the middle of the extension. The outer shape of the tube main body 2 having the T-shaped internal flow path P is also substantially T-shaped.

In such a resin piping member, when the inner diameter at the welding end is constant with the same size as the inner diameter at the tube main body, when abutting and welding at the end with another resin piping member, Due to the fact that the ends melted by heating are pressed at a predetermined pressure, the resin at the weld end escapes to the inner and outer peripheral sides of the pipe and rises and cools and cures in that state, thereby mutual An inner bead that protrudes toward the inner peripheral side and an outer bead that protrudes toward the outer peripheral side are formed at the welded portion at the position of the end portion welded to the outer peripheral side. Such an inner bead is a pipe including the resin pipe member, and when a liquid or the like is flowed, the smooth flow of the liquid is obstructed to cause a liquid pool there, and a local flow rate there. Incurs the problem of reducing.

In order to cope with this, in the present invention, as can be seen from the enlarged view of the welding end portion 3c in FIG. 3, the welding end portions 3a to 3c have an inner diameter enlarged portion having a larger inner diameter than the tube main body portion 2. 4 is provided. The inner diameter enlarged portion 4 receives the molten resin at the welding end portions 3a to 3c, which is pressed with a predetermined force and is slightly shortened at the time of welding with the end portion of another resin piping member. It functions to prevent the flow to the inner circumference side.

Further, here, the inner surface of the enlarged inner diameter portion 4 is inclined with respect to a plane perpendicular to the central axis C of the internal flow path P at the position of the welding end portions 3a to 3c, and inclination angles θ1 and θ2 with respect to the plane are set. The inclined surface changes in the middle of the internal flow path P in the axial direction.
As a result, at the time of welding with the end portion of another resin piping member, the molten resin on the tip end side (opening portion A1 to A3 side of the internal flow path P) of the welding end portions 3a to 3c changes the inclination angle of the inner surface. The welding end portions 3a to 3c can flow to the portion of the tube main body portion 2 side.

As a result, as illustrated in FIG. 4, in the welded portion where the ends of the resin piping member 1 and the other resin piping member 51 are welded, the formation of the inner bead is suppressed, and the inner diameter D1 is reduced. , Can be sufficiently close to the inner diameter of the adjacent portion. In addition, since resin slightly flows also on the outer peripheral side of the pipe at the time of welding, an outer bead is formed although it is smaller than the prior art as illustrated in FIG. It does not affect the flow of the liquid flowing through the flow path, but rather can increase the welding strength.
More preferably, as shown in FIG. 4, the inner diameter D <b> 1 of the welded portion 52 between the resin pipe member 1 and the other resin pipe member 51 is an inner diameter of a location adjacent to the welded portion 52, for example, the tube main body portion 2. It becomes equal to the inner diameter D2 or the like. Here, the fact that the inner diameter D1 of the welded portion 52 is equal to the inner diameter D2 of the tube main body portion 2 does not require that the inner diameter D1 and the inner diameter D2 completely coincide with each other. It means that the following inner diameter difference is allowed. This difference in inner diameter does not hinder the flow of liquid during use to such an extent that it has an adverse effect, and cannot be regarded as an inner bead.
When the resin piping member 1 and another resin piping member are welded at the end portions, it is more preferable to provide a similar inner diameter enlarged portion at the welding end portion of the other resin piping member.

If the inclination angle of the inner surface of the inner diameter enlarged portion is constant as in the prior art, when welding with the end portion of another resin piping member, the length of the molten resin at the weld end portion that is shortened by pressing is reduced. Since there is not enough escape space on the tube body 2 side, an inner bead is formed as a result of the molten resin flowing toward the inner peripheral side.

In the illustrated embodiment, the three inner end portions 3a to 3c are all provided with the inner diameter enlarged portion 4 as described above, but at least one of them has the inner diameter enlarged portion so that the weld end portion is provided. And an inner bead at the time of welding with the end part with other resin piping members can be prevented.

Here, in the embodiment shown in FIG. 3, the inner surface of the enlarged inner diameter portion 4 is inclined outwardly at an inclination angle θ1 with respect to a plane perpendicular to the central axis C of the internal flow path P at the position of the welding end 3c. A surface 5a and an inner inclined surface 5b that is located closer to the central axis C than the outer inclined surface 5a and is inclined at an inclination angle θ2 larger than the inclination angle θ1 with respect to a plane orthogonal to the central axis C. . Each of the inclination angles θ1 and θ2 is an acute angle with respect to a plane orthogonal to the central axis C, and means an angle inclined with respect to the plane orthogonal to the central axis C. Not included.
In this case, at the time of welding with the end of another resin piping member, the resin present at the position of the outer inclined surface 5a can be melted and flow toward the inner inclined surface 5b having a larger inclination angle. From the viewpoint of preventing inner beads more reliably.

The inclination angle θ1 of the outer inclined surface 5a is preferably 3 ° to 20 ° with respect to the plane orthogonal to the central axis C. When the inclination angle θ1 is smaller than 3 °, the flow is almost parallel to the plane orthogonal to the central axis C (that is, substantially perpendicular to the central axis C), so that the flow of the molten resin toward the inner peripheral side is sufficient. There is a possibility that inner beads are easily generated without being suppressed. On the other hand, when the inclination angle θ1 is larger than 20 °, the molten resin does not sufficiently fill the inner inclined surface 5b, and the inner surface may be recessed, and the outer bead may become too large.

The inclination angle θ2 of the inner inclined surface 5b is preferably 30 ° to 60 ° with respect to the plane orthogonal to the central axis C. When the inclination angle θ2 is less than 30 °, there is a concern that the inner bead becomes large. Further, when the inclination angle θ2 exceeds 60 °, the molten resin may not sufficiently fill the inside inclined surface 5b, so that the inner surface may be dented, and abutted with the end of another resin piping member. At this time, in order to sufficiently weld the end portions, it is necessary to increase the pushing amount between the end portions, so that the outer bead may become too large.
Such a preferable numerical range of the inclination angles θ1 and θ2 is considered to be different depending on the material forming the resin piping member.

In this embodiment, the length L1 of the outer inclined surface 5a in the direction along the central axis C of the internal flow path P is expressed as a ratio (L1 / L2) to the same length L2 of the inner inclined surface 5b, and is expressed as 0. .04 to 2.71. That is, when this ratio (L1 / L2) is smaller than 0.04, the molten resin may not sufficiently fill the inner inclined surface 5b, and the inner surface may be depressed, and other resin pipes may be formed. When the end portions of the members are brought into contact with each other, in order to sufficiently weld the end portions, it is necessary to increase the pushing amount between the end portions, so that the outer bead may become too large. Moreover, when larger than 2.71, it is possible that an inner bead becomes high.
Specifically, the length L1 of the outer inclined surface 5a can be 0.02 mm to 0.47 mm, and the length L2 of the inner inclined surface 5b is 0.17 mm to 0.52 mm. Can do. The length (L1 + L2) of the inner diameter enlarged portion 4 in the direction along the central axis C of the internal flow path P can be 0.19 mm to 0.99 mm.

In FIG. 3, each of the outer inclined surface 5a and the inner inclined surface 5b is a linear tapered surface that is linear in the illustrated longitudinal section along the central axis C, but at least one of the inclined surfaces Can be a curved tapered surface having a curved shape in the illustrated longitudinal section.
Further, as shown in FIG. 5 (a), for example, the inner diameter gradually increases from the inner surface of the tube main body 2 to the tips of the welding end portions 3a to 3c, and the entire inner diameter is increased by a curved tapered surface. It can also be part 14.

In the modification shown in FIG. 5A, the inclination angle θ of the inner surface of the inner diameter enlarged portion 14 means the angle on the acute angle side with respect to the plane perpendicular to the central axis C of the tangent line TL of the curve in the illustrated longitudinal section. . Also in this modified example, the inner surface of the inner diameter enlarged portion 14 has an inclination angle θ with respect to a plane perpendicular to the central axis C that changes in the middle of the axial direction. Since it increases gradually toward the main body part 2 side, it has an outer inclined surface and an inner inclined surface inclined at an inclination angle larger than the inclination angle of the outer inclined surface.
However, depending on the method of forming the inner diameter enlarged portion described later, the outer inclined surface 5a and the inner inclined surface 5b made of a linear tapered surface shown in FIG. 3 may be easier to form.

Further, the inner diameter enlarged portion includes an outer inclined surface 25a positioned on the outer side with respect to the central axis C and an inner inclined surface 25b positioned on the central axis C side, as in a further modification shown in FIG. And an inclined surface with three or more different inclination angles, such as an inner diameter enlarged portion 24 of an inner surface composed of an outer inclined surface 25a and an intermediate inclined surface 25c located between the outer inclined surface 25a and the inner inclined surface 25b. It can be. In this case, the inclination angle can be increased from the outer inclined surface toward the inner inclined surface with respect to the central axis C. Specifically, in the inner diameter enlarged portion 24 shown in FIG. 5B, the inclination angle θ1 of the outer inclined surface 25a, the inclination angle θ3 of the intermediate inclined surface 25c, and the inclination angle θ2 of the inner inclined surface 25b are arranged in this order. Has increased.

The outer surfaces of the inner diameter enlarged portions 4, 14, and 24 are not so important from the viewpoint of the flow of the liquid. However, as in the illustrated embodiment, the outer surfaces of the inner flow path P are in a longitudinal section along the central axis C. It can be a straight line parallel to the central axis. If the outer diameter of the inner diameter enlarged portion is not linear, but the outer diameter is increased at the inner diameter enlarged portion, the amount of the resin existing there is increased and the inner bead cannot be sufficiently suppressed. In addition, if the outer diameter is reduced at the inner diameter enlarged portion, the amount of resin contributing to welding with the end of another resin piping member is reduced, and it is sufficiently strong with other resin piping members. There is a risk that it will not be welded.

In order to form the inner diameter enlarged portions 4, 14, and 24 as described above on the welding end portions 3a to 3c, for example, after the resin piping member 1 is formed by injection molding, extrusion molding or other methods, the welding end is formed. It can be performed by cutting the portions 3a to 3c and providing a predetermined shape of inclined surface on the inner surface.
Alternatively, when the resin piping member 1 is molded by injection molding, the core pin disposed in the cavity of an injection mold (not shown) may have a shape that expands in diameter at a position corresponding to the welding end portions 3a to 3b. The inner diameter enlarged portions 4, 14, and 24 can be formed.

In the above description, the example in which the resin pipe member is a resin pipe joint called T-shaped cheese in which the internal flow path P branches in the middle has been described. 6 (a), a resin pipe joint 31 called an L-shaped elbow in which the internal flow path P bends or curves in the middle, or an internal flow as shown in FIG. 6 (b). It can be set as the resin pipe joint 41 called the reducer from which the diameter of the path P changes on the way. Further, the resin piping member is bent or curved by heating a straight tube-shaped resin tube member 61 having a straight internal flow path P as shown in FIG. It is also possible to provide a bent tubular resin tube member.
By selecting appropriate ones from such resin piping members, welding the resin piping members at the ends and sequentially connecting them, manufacturing a pipe of the desired shape Can do.

Examples of the material constituting the resin piping member include perfluoroalkoxyalkane (PFA), perfluoroethylene propene copolymer (FEP), and polyetheretherketone (PEEK). It is also possible to use other than these.

Next, since a resin piping member according to the present invention was prototyped and its effect was confirmed, it will be described below. However, the description here is for illustrative purposes only and is not intended to be limiting.

Example 1
Using a resin pipe member having an outer diameter of 19.05 mm (3/4 inch), Invention Example 1 in which a double taper is provided at the welding end and Comparative Example 1 in which a single taper is provided are respectively prototyped and their inventions. In Example 1 and Comparative Example 1, it was verified whether or not the height of the inner bead formed by end welding was different.

The end face of the welded end of the resin piping member having a wall thickness of 1.59 mm and an outer diameter of 19.05 mm is linearly inclined at an angle θ1 of 10 ° with respect to a plane perpendicular to the central axis of the internal flow path. Chamfering of a double taper composed of an outer inclined surface and an inner inclined surface inclined linearly at an angle θ2 of 45 ° with respect to a similar plane was made, and this was designated as Invention Example 1. In Invention Example 1, the thickness T1 of the outer inclined surface in the direction along the plane perpendicular to the central axis of the internal flow path was 1.29 mm, and the thickness T2 of the same inner inclined surface was 0.3 mm.

In addition, a single taper chamfer consisting of a single inclined surface that is linearly inclined at an inclination angle of 10 ° with respect to a plane perpendicular to the central axis of the internal flow path is formed on the end surface of the welding end portion of a similar resin piping member. This was designated as Comparative Example 1.

A test was conducted in which two of the resin piping members of Invention Example 1 were welded at the ends. In Invention Example 1, since the welding was insufficient, the amount of pushing in the direction in which the end portions were brought into contact with each other during welding was 1.1 mm. Then, when the inner surface of the welded portion was observed, an inner bead of 0.2 mm was generated at a location that protruded highest on the inner peripheral side.

When two of the resin-made piping members of Comparative Example 1 were welded at the end portions, in Comparative Example 1, since a large amount of resin was present at the welded end portions, the amount of pushing should be 0.9 mm and welded sufficiently. Was possible.
On the inner surface of the welded portion after the welding, an inner bead of 0.3 mm was generated at a location that protruded highest on the inner peripheral side.

From the above test, the invention example 1 has a smaller inner bead than the comparative example 1 in spite of the fact that the indentation amount at the time of welding is larger than that of the comparative example 1. It was found that the occurrence of beads can be suppressed.

(Example 2)
Double tapers with different inclination angles and lengths were provided on the resin piping member having an outer diameter of 3.17 mm (1/8 inch) and the resin piping member having an outer diameter of 9.53 mm (3/8 inch). Invention examples 2 and 3 were manufactured as prototypes, and the presence or absence of internal beads due to the difference in the size and shape of the double taper was verified.

In Invention Example 2, the angle of inclination θ1 of the outer inclined surface is 3 on the end surface of the welded end of the resin piping member having an inner diameter of 2.17 mm, an outer diameter of 3.17 mm, and a wall thickness of 0.79 mm. A double taper with an inclination angle θ2 of the inner inclined surface of 60 ° was provided. In Example 2, the ratio (L1 / L2) of the length L1 of the outer inclined surface to the length L2 of the inner inclined surface was 0.04.

In invention example 3, the angle of inclination θ1 of the outer inclined surface is 20 on the end surface of the welded end portion of the resin piping member whose inner diameter is 6.35 mm, outer diameter is 9.53 mm, and wall thickness is 1.59 mm. It was assumed that a double taper with an inclination angle θ2 of the inner inclined surface of 30 ° was provided. In Invention Example 3, the ratio (L1 / L2) of the length L1 of the outer inclined surface to the length L2 of the inner inclined surface was 2.71.

About each of said invention example 2 and 3, when the test which welds the edge part of two resin piping members was done like Example 1 described previously, all of invention examples 2 and 3 were Similarly to the above-described Invention Example 1, the height of the inner bead formed in the welded portion could be lowered to such an extent that the flow of the liquid was not inhibited.
Therefore, it has been found that the generation of the inner bead can be sufficiently effectively suppressed within the range of the above-described dimensional shape of the outer inclined surface and the inner inclined surface provided at the welding end.

1, 31, 41, 61 Resin piping member (resin pipe joint, resin tube member)
2 Pipe body portion 3a to 3c Weld end portion 4 Inner diameter enlarged portion 5a, 25a Outer inclined surface 5b, 25b Inner inclined surface 25c Intermediate inclined surface 51 Other resin piping member 52 Welded portion θ1, θ2, θ3, θ Inclination angle L1 Length of outer inclined surface L2 Length of inner inclined surface D1, D2 Inner diameter TL Tangent P Internal flow path A1-A3 Opening portion of internal flow path C Center axis of internal flow path

Claims (9)

1. Two or more pipe body parts having an internal flow path for fluid flow and two or more openings provided in each of the two or more opening portions of the internal flow path and butted against the ends of other resin piping members A resin-made piping member provided with a welding end of
   At least one of the welding end portions is provided with an inner diameter enlarged portion having an inner diameter larger than that of the tube main body portion, and the inner surface of the inner diameter enlarged portion is orthogonal to the central axis of the internal flow path at the position of the welding end portion. A resin-made piping member that is inclined with respect to a plane and has an inclination angle with respect to the plane that changes in the middle of the axial direction of the internal flow path.
2. The inner surface of the inner diameter enlarged portion has an outer inclined surface that is inclined with respect to a plane orthogonal to the central axis of the internal flow path at the position of the welding end, and is orthogonal to the central axis on the central axis side from the outer inclined surface. The resin piping member according to claim 1, further comprising an inner inclined surface that is inclined at a larger angle than the outer inclined surface with respect to a flat surface.
3. 3. The resin piping member according to claim 2, wherein each of the inner inclined surface and the outer inclined surface is a linear tapered surface that is linear in a longitudinal section along the central axis.
4. The resin piping member according to claim 3, wherein the outer inclined surface is inclined at 3 ° to 20 ° with respect to a plane perpendicular to the central axis of the internal flow path at the position of the welding end.
5. The resin piping member according to claim 3 or 4, wherein the inner inclined surface is inclined at 30 ° to 60 ° with respect to a plane perpendicular to the central axis of the internal flow path at the position of the welding end.
6. The resin piping member according to any one of claims 1 to 5, wherein an outer surface of the inner diameter enlarged portion has a vertical cross section along the central axis and a straight line parallel to the central axis of the internal flow path.
7. A resin pipe joint comprising the resin pipe member according to any one of claims 1 to 6.
8. A method of manufacturing a pipe by connecting a plurality of resin piping members, wherein at least one resin of the two resin piping members is connected to each other. The pipe member made of resin is the resin pipe member according to any one of claims 1 to 6, and the welding end portions of the two resin pipe members are heated and melted, and then A method for manufacturing piping, in which welded end portions are butted against each other.
9. The pipe manufacturing method according to claim 8, wherein an inner diameter of the two resin pipe members connected to each other by welding the weld end parts is equal to an inner diameter of a portion adjacent to the weld part. .

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