JP6899900B2 - Resin tube members, manufacturing methods for resin tube members, resin pipe fittings, and resin piping - Google Patents

Description

INDUSTRIAL APPLICABILITY According to the present invention, a resin tube member in which an internal flow path through which fluid flows is formed and connected to a resin pipe joint or another resin tube member by welding at the end, a method for manufacturing a resin tube member, It relates to resin pipe joints and resin pipes, and in particular, effectively utilizes so-called inner beads that may occur when a resin tube member is welded to a resin pipe joint or another resin tube member at an end. It proposes a technology that can be suppressed.

Resin pipes such as chemical transport lines used in various industries are welded by abutting each end of a resin pipe joint made of thermoplastic resin or the like or a resin tube member by using a welding machine. May be manufactured.

To elaborate on an example of such a method for manufacturing a resin pipe, for example, two resin tube members and resin pipe joints are attached to each of the clamp jigs paired with the welding machine at their ends. Hold the parts in a posture facing each other. Next, the ends of the two resin tube members held by each clamp jig are heated by a heater or the like to melt the ends, and in that state, the two resin tubes are made. The tube members and the like are brought close to each other, and the ends thereof are abutted and welded by the action of a required pressure. By repeatedly welding the ends of the resin tube member or the like to connect the resin tube member or the like, a pipe having a predetermined shape can be manufactured.

Here, in order to connect the resin tube members or the resin tube member and another resin pipe joint as described above, in order to obtain sufficient welding strength, prior to welding the ends. It is necessary to heat at a predetermined high temperature and then apply a predetermined large pressure when abutting the ends.
However, in this case, due to such heating and pressurization, a flow of the molten resin is generated at the end of the molten state at the time of abutting, and the resin is cured in a state of being raised from the inner surface to the inner peripheral side. , A raised portion may be formed on the inner surface of the welded portion. Such a ridge is sometimes referred to as an inner bead. Further, since the inner bead formed on the inner surface of the welded portion of the pipe partially narrows the inner diameter of the pipeline, there is a problem that when the liquid flows, a liquid pool is generated there and the flow rate is lowered.

In response to this problem, in Patent Document 1, "a method of welding synthetic resin tubular members", "after heating and melting the ends of the first and second synthetic resin tubular members, the end faces are joined to each other. It is a method of butt welding, in which internal pressure is applied to both tubular members at the time of butt welding, and "chamfering of the inner diameter portion of the butt end portion of both tubular members before heating" has been proposed. Then, according to this method, "the convex amount of the inner surface of the bead portion existing in the butt portion can be reduced, and by using the tubular member thus obtained for the piping, the joint portion allows a smooth flow of the liquid. It is not hindered, and it is also possible to prevent the joint from becoming a liquid pool and prolonging the time required for liquid replacement. "

Japanese Unexamined Patent Publication No. 2004-284048

In the technique proposed in Patent Document 1, internal pressure is applied when the ends of resin tube members and the like are butted against each other and welded, so that a welding machine and a pressurizing device for applying the internal pressure are required, which requires equipment cost. There was another problem that the working time was increased due to pressurization. In particular, when a plurality of resin tube members and resin pipe joints are sequentially connected to form a pipe, a pressurizing device must be arranged each time the ends thereof are welded to each other. It is undeniable that the production efficiency has declined.

An object of the present invention is to solve such a problem of the prior art, and an object of the present invention is to connect a resin tube member to a resin tube joint or another resin tube member and an end portion. It is an object of the present invention to provide a resin tube member, a method for manufacturing a resin tube member, a resin pipe joint, and a resin pipe capable of effectively suppressing an inner bead that may be generated in a welded portion at the time of welding.

The resin tube member of the present invention is arranged so as to cover at least the periphery of at least the end of the tube body on the outer peripheral side of the tube body and the tube body in which an internal flow path through which a fluid flows is formed. The outer cylinder end portion which has an outer cylinder fixed or fixed to the tube main body and is welded to the end portion of another resin tube member or resin pipe joint is an axis line from the main body end portion on the inner peripheral side thereof. An inner surface step is provided which is located so as to protrude outward in the direction and is formed by the inner surface of the outer cylinder end portion and the inner surface of the main body end portion. It has a tapered shape that inclines inward in the direction.

In the resin tube member of the present invention, it is preferable that the outer cylinder is welded to the tube body.
In this case, it is more preferable that the outer cylinder is formed by welding to the tube body by insert molding.

Here, in the resin tube member of the present invention, it is preferable that the height of the inner surface step in the radial direction is 0.5 mm to 1.5 mm.
Further, in the resin tube member of the present invention, it is preferable that the protrusion length of the outer cylinder end portion in the axial direction with respect to the main body end portion of the tube body is 0.2 mm to 1.0 mm.

Further, in the resin tube member of the present invention,
The inclination angle of the end face of the tapered shape is preferably in the range of 5 ° to 10 ° with respect to the plane orthogonal to the axial direction.

Further, in the resin tube member of the present invention, it is preferable that the end face of the outer cylinder end portion has an area more than twice as large as that of the end face of the main body end portion of the tube body.

The method for manufacturing a resin tube member of the present invention is a method for manufacturing any of the above resin tube members, in which at least the end of the main body of the tube body is arranged in an injection molding die, and the injection molding die is formed. It has an outer cylinder molding step of forming an outer cylinder on the outer peripheral side of the tube body by injecting a resin material into the mold.
In the method for manufacturing a resin tube member of the present invention, it is preferable to further include a main body molding step of forming a tube main body by extrusion molding prior to the outer cylinder molding step.

The resin pipe joint of the present invention is connected to any of the above resin tube members by welding the end portion, and the joint end portion welded to the outer cylinder end portion of the resin tube member. In addition, a step on the inner surface is provided.

In the resin pipe joint of the present invention, the height of the inner surface step at the end of the joint in the radial direction is preferably 0.5 mm to 1.5 mm.
Further, in the resin pipe joint of the present invention, the end face of the joint end has a tapered shape that gradually inclines inward in the axial direction toward the inside in the radial direction, and the end face of the tapered shape has a tapered shape. The inclination angle is preferably in the range of 5 ° to 10 ° with respect to the plane orthogonal to the axial direction.

The resin pipe of the present invention includes at least one of the above resin tube members, and is a connection point between the resin tube member and another resin tube member or resin pipe joint, and / Or, inside the connecting portion between the resin tube members, at least a part of the inner surface step is filled with the resin portion at the end of the outer cylinder, and the connecting portion is equal to or equal to the inner diameter of the tube body. It has an inner diameter larger than the inner diameter.

According to the present invention, an outer cylinder that covers at least the periphery of the end of the main body is arranged on the outer peripheral side of the tube body of the resin tube member, and the end of the outer cylinder to be used for welding the end is the inner circumference thereof. By projecting from the end of the main body on the side to the outside in the axial direction and providing an inner surface step there, the end of another resin tube member or resin pipe joint and the end of the outer cylinder are butted against each other. When welding is performed, the resin portion that rises on the inner peripheral side is filled in at least a part of the inner surface step, and the uplift of the resin portion toward the inner peripheral side is suppressed, so that the formation of the inner bead at the welded portion is effective. It can be suppressed.

It is a vertical sectional view including a central axis which shows the main part of the resin tube member of one Embodiment of this invention. It is a partially enlarged vertical sectional view of FIG. It is a vertical cross-sectional view which shows the resin tube member of FIG. 1 together with the resin pipe joint connected to it. FIG. 3 is a vertical cross-sectional view showing a welded portion which is a connecting portion between the resin tube member and the resin pipe joint of FIG. It is a vertical cross-sectional view which shows the deformation example of the outer cylinder of a resin tube member. It is a vertical cross-sectional view which shows the other modification of the outer cylinder of a resin tube member. It is a vertical cross-sectional view which shows the resin tube member of the comparative example in an Example in the state before and after welding of the end part. It is a vertical cross-sectional view which shows the resin tube member of Invention Example 1 in an Example in the state before and after welding of the end part. It is a vertical cross-sectional view which shows the resin tube member of Invention Example 2 in an Example in the state before and after welding of the end part.

Embodiments of the present invention will be described in detail below with reference to the drawings.
The resin tube member 1 illustrated in FIG. 1 has a straight or curved straight tube or curved tube body 2 in which an internal flow path P through which a liquid such as a chemical solution or a gas or other fluid flows is formed. The outer tube 3 has a tubular shape such as a cylinder, which is arranged on the outer peripheral side of the tube body 2 so as to cover at least the periphery of the end portion 2a of the tube body 2 and is fixed or fixed to the tube body 2. It is made up of.

The tube body 2 and the outer cylinder 3 constituting the resin tube member 1 are made of a resin material such as perfluoroalkoxy alkane (PFA), perfluoroethylene propene copolymer (FEP), or polyetheretherketone (PEEK), respectively. Yes, they can be formed using the same or different resin materials.

Here, in the resin tube member 1, as shown in an enlarged view in FIG. 2, the outer cylinder end 3a of the outer cylinder 3 is more than the main body end 2a of the tube body 2 arranged on the inner peripheral side thereof. It is positioned so as to protrude to the outside of the axial direction AD, whereby an inner surface step 4 having a height in the radial direction is formed between the inner surface of the outer cylinder end portion 3a and the inner surface of the main body end portion 2a.

More specifically, the resin tube member 1 has a relatively small inner diameter Dt of the tube body 2 in the portion where the tube body 2 inside the axial direction AD exists, but the end portion of the resin tube member 1. On the outside of the axial direction AD from the inner surface step 4 in the above, the outer cylinder end portion 3a protrudes to the outside of the axial direction AD from the main body end portion 2a, and the tube main body 2 does not exist, so that the outer cylinder end portion 3a is relatively relative. It has a large inner diameter Dc. As a result, an enlarged diameter space 5 is formed at the end of the resin tube member 1 so as to be partitioned by the inner surface step 4 and the inner surface of the outer cylinder end 3a.

In order to manufacture a pipe using such a resin tube member 1, the resin tube members 1 are welded to each other by welding the resin tube member 1 with another resin tube member or a resin pipe joint at an end. And / or the connection between the resin tube member and the resin pipe joint is repeated.
Specifically, for example, the end of the resin tube member 1 and the end of another resin tube member or resin pipe joint are welded to each of the clamp jigs that form a pair of welding machines (not shown). Each of the resin tube members 1 and the like is held in a posture in which the portions face each other, and then both ends of the resin tube member 1 and the like held by the clamp jig are heated by a heater or other heating device. This can be done by bringing the resin tube members 1 and the like closer to each other in the molten state and abutting their ends by the action of a required pressure.

Here, as shown in FIG. 3, the resin tube member 1 is welded and connected to the joint end 11a of the resin pipe joint 11 at the outer cylinder end 3a.
According to this, at the time of welding the end portion, the resin portion of the outer cylinder end portion 3a, which is abutted against the joint end portion 11a of the resin pipe joint 11 in a molten state at a predetermined pressure, is affected by the action of the pressure. Although the 21 flows in the radial direction and moves to the inner peripheral side, as shown in FIG. 4, the resin portion 21 enters the enlarged diameter space 5 provided there through the inner surface step 4, so that the resin portion 21 However, it is prevented from rising from the inner surface to the inner peripheral side of the inner flow path P of the tube main body 2 which forms a part of the pipe line of the pipe. Therefore, it is possible to effectively suppress the generation of inner beads that cause problems such as liquid pooling and a decrease in flow rate. As a result, the heating and pressurizing conditions at the time of welding can be set without considering the formation of the inner bead, so that the ends can be welded with sufficiently high strength.

Therefore, the resin pipe produced in this way has a connection point Cp between the resin tube member 1 provided therein and another resin tube member or a resin pipe joint 11, and a connection between the resin tube members 1. Inside the portion, as shown in FIG. 4, at least a part of the inner surface step 4 is filled with the resin portion 21 of the outer cylinder end portion 3a, and the connecting portion Cp is the inner diameter Dt of the tube body 2. It is preferable to have an inner diameter equal to or larger than the inner diameter Dt. That is, the inner surface step 4 of the resin tube member 1 and the inner surface step 4 so that there is no ridge such as an inner bead whose inner diameter is smaller than the inner diameter Dt of the tube body 2 at the connecting portion Cp of the manufactured resin pipe. Design the dimensions and shape of the outer cylinder 3, tube body 2, etc.
Specifically, when the inner diameter at the connecting portion Cp is equal to or larger than the inner diameter Dt of the tube body 2, the difference between the inner diameter at the connecting portion Cp and the inner diameter Dt of the tube body 2 is preferably the largest diameter of the connecting portion Cp. The part where is large is 0 mm or more and 1 mm or less. If the inner diameter at the connecting portion Cp becomes too large than the inner diameter Dt of the tube body 2, there is a concern that liquid pooling may occur.

Here, in the illustrated embodiment, the outer cylinder 3 is arranged in a region covering the end portion side portion including the main body end portion 2a of the tube main body 2. However, even when the outer cylinder is provided so as to cover the entire circumference of the tube body in the axial direction, if an inner surface step is formed at the end of the outer cylinder, the inner bead suppressing effect as described above is obtained. Therefore, the outer cylinder may be arranged so as to cover at least the end portion of the main body.

The outer cylinder 3 is preferably welded to the tube main body 2, and particularly preferably welded to the tube main body 2 by insert molding as described later, but the present invention is not limited to this, for example, the use of an adhesive or the outer cylinder. And the concave portion and the convex portion (not shown) formed in each of the tube main body may be fixed or fixed by fitting or engaging or other various methods.

The inner surface step 4 formed by the outer cylinder end portion 3a and the main body end portion 2a preferably has a height Hs in the radial direction of 0.5 mm to 1.5 mm. When the radial height Hs of the inner surface step 4 is smaller than 0.5 mm, the inner surface that allows the resin portion 21 to swell when welded to the joint end portion 11a of the resin joint 11 at the outer cylinder end portion 3a. If the step 4 is too small, the inner bead may be raised and formed on the inner peripheral side. On the other hand, if the radial height Hs of the inner surface step 4 is made larger than 1.5 mm, there is a concern that the welding strength may be insufficient or liquid pooling may occur.

Further, the protrusion length Lc of the outer cylinder end portion 3a in the axial direction AD with respect to the main body end portion 2a of the tube main body 2 is preferably 0.2 mm to 1.0 mm, for example. If the protruding length Lc of the outer cylinder end 3a is too long, liquid pooling may occur, while if the protruding length Lc is too short, the tube body 2 is melted at the time of welding and the tube is formed. This is because an inner bead that exceeds the inner surface of the main body 2 may be generated.

In the illustrated resin tube member 1, the enlarged diameter space 5 formed by the inner surface step 4 as described above is formed by the end surface of the main body end portion 2a parallel to the plane orthogonal to the axial direction AD and the outer cylinder end portion 3a. It is partitioned by the inner surface of the protruding portion to form an annular shape with a substantially rectangular cross section.

Here, the area of the end surface 3b of the outer cylinder end portion 3a welded to the joint end portion 11a or the like of the resin pipe joint 11 is the area of the end surface of the main body end portion 2a forming the inner surface step 4 with the outer cylinder end portion 3a. It is preferable to double or more. As a result, it can be sufficiently firmly welded to the joint end portion 11a or the like of the resin pipe joint 11. However, if the area of the end surface 3b of the outer cylinder end portion 3a is too large, there is a concern that the appearance may be poor such as sink marks. Therefore, the area of the end surface 3b of the outer cylinder end portion 3a is the area of the end surface of the main body end portion 2a. It can be three times or less the area.

Further, in order to more effectively prevent the resin portion from rising to the inner peripheral side at the time of welding, the end surface 3b of the outer cylinder end portion 3a is gradually axially oriented toward the inside in the radial direction as shown in the illustrated embodiment. It can have a tapered shape that inclines inwardly toward the inside of the AD. More specifically, the inclination angle θ of the tapered end surface 3b of the outer cylinder end portion 3a is preferably in the range of 5 ° to 10 ° with respect to the plane orthogonal to the axial direction AD. If the inclination angle θ of the tapered end surface 3b is less than 5 °, there is a concern that the resin portion 21 rises too much toward the inner peripheral side, and if the inclination angle θ is larger than 10 °, welding may be insufficient. However, such a tapered shape of the end surface 3b of the outer cylinder end portion 3a is not an essential configuration.
Although not shown, in addition to or instead of having the end surface 3b of the outer cylinder end portion 3a having a tapered shape, the end surface of the main body end portion of the tube body can have a similar tapered shape. Is. In this case, the tapered end face of the main body end may also be inclined within a range of 5 ° to 10 ° with respect to a plane orthogonal to the axial direction.

It is preferable that the outer cylinder 3 and the inner surface step 4 resulting from the above are formed at both ends of the resin tube member 1 from the viewpoint of effectively suppressing the generation of inner beads due to welding at both ends. Depending on the mode of the other resin tube member welded to each end or the end of the resin pipe joint, only one end of the resin tube member 1 has the outer cylinder 3 and the inner surface step 4 May be formed. Similarly, the tapered shape of the end surface 3b of the outer cylinder end portion 3a can be provided at at least one end portion.

As in the modified example shown in FIG. 5, an outer surface step 34 that reduces the outer diameter on the outer side in the axial direction can be provided on the outer surface side of the outer cylinder end portion 33a of the outer cylinder 33. Since the outer surface step 34 can effectively suppress the swelling of the resin portion to the outer peripheral side at the time of welding with the joint end portion 11a of the resin pipe joint 11, from the viewpoint of the arrangement space of the pipe and the appearance. preferable. The dimensional shape of the outer surface step 34 can be appropriately set according to a predetermined condition such as the size of the end face, but the dimensional shape may be the same as that of the inner surface step 4.

Further, as in another modification shown in FIG. 6, the inner surface of the outer cylinder end 43a of the outer cylinder 43 is opened on the inner surface side and the axial outer side of the outer cylinder end 43a, respectively, on the outer side in the axial direction. An inner recess 46 that increases the inner diameter can be provided. As a result, the inner bead can be more reliably recessed on the outer peripheral side of the inner surface of the tube. Even in this case, the end surface 43b of the outer cylinder end portion 43a is located so as to protrude outward in the axial direction from the end surface of the main body end portion 2a of the tube main body 2, and the inner surface of the outer cylinder end portion 43a and the main body end portion. An inner surface step 4 is formed between the inner surface and the inner surface of 2a.
The axially formed region of the inner recess 46 is, for example, from a position 0.5 mm inward in the axial direction from the end surface of the main body end 2a of the tube body 2 to a position 1.0 mm outward in the axial direction from the end surface. be able to. The radial length of the inner recess 46 can be, for example, 0.5 mm to 1.0 mm.
In the place shown in FIG. 6, the outer cylinder end portion 43a is provided with the outer surface step 44 together with the inner recess 46, but although not shown, the outer surface step 44 may be provided and only the inner recess 46 may be provided. ..

Of the resin pipe joint 11 that is connected to the resin tube member 1 by welding the ends, the joint end 11a that is welded to the outer cylinder end 3a of the resin tube member 1 is also the one of the resin tube member 1. It is preferable that the inner surface step 12 substantially similar to the above is provided. In this case, from the same viewpoint, the radial height of the inner surface step 12 of the joint end portion 11a is 0.5 mm to 1.5 mm, and the end surface 11b of the joint end portion 11a becomes inward in the radial direction. It shall have a tapered shape that gradually inclines inward in the axial direction, and the inclination angle of the end face 11b of the tapered shape shall be within the range of 5 ° to 10 ° with respect to the plane orthogonal to the axial direction. Each is preferable.

As the resin pipe joint 11, for example, an elbow in which the internal flow path is bent in a substantially L shape, cheese in which the internal flow path branches in the middle to form a T shape, etc., and a cross-sectional area of the internal flow path changes in the middle. There is a reducer etc.

To describe an example of the method for manufacturing the resin tube member 1 as described above, first, a main body molding step of forming the tube main body 2 from a predetermined resin material by extrusion molding or the like is performed. Here, the tube body 2 can also be formed by forming a long tubular material by extrusion molding and cutting it to a predetermined length. This cutting can be divided into, for example, a first-stage cutting in which a long tubular material is roughly cut, and then a second-stage cutting in which the end face is finished while being cut to a predetermined length with high accuracy. ..

After that, at least the end portion 2a of the main body 2 of the tube main body 2 is arranged in the injection molding die, and the inner surface shape corresponding to the shape of the outer cylinder 3 to be formed around the tube main body 2 in the injection molding die. A resin material is injected into the cavity, and the resin material is cooled and cured there to perform an outer cylinder molding step of forming an outer cylinder 3 on the outer peripheral side of the tube body 2. By such insert molding, an outer cylinder 3 having a predetermined shape can be formed by welding to a predetermined position around the tube body 2, so that the separately formed outer cylinder 3 is subsequently attached to the tube body 2. It is preferable in that it can be formed easily and in a short time as compared with the case of fixing or fixing.

Prior to the outer cylinder molding step of forming the outer cylinder 3 around the tube main body 2 by insert molding as described above, a preheating step of heating at least the main body end 2a of the tube main body 2 to make it in a semi-molten state is performed. It is also possible. As a result, the tube body 2 and the outer cylinder 3 are firmly integrated at the time of insert molding in the outer cylinder forming step. However, this preheating step may be omitted.

Here, by adjusting the cavity shape of the injection molding die, the outer cylinder 3 having the above-mentioned tapered end surface 3b can be molded around the tube main body 2. Alternatively, in the outer cylinder molding step, the outer cylinder 3 having an end face parallel to the plane orthogonal to the axial direction AD is once formed, and after the outer cylinder molding step, the end face of the outer cylinder end portion 3a is used by using an end face cutter or the like. It is also possible to carry out an end processing step of processing the taper shape.

Next, the resin tube member of the present invention was prototyped and its performance was confirmed, which will be described below. However, the description here is for the purpose of mere illustration, and is not intended to be limited thereto.

As a comparative example, as shown in FIG. 7A, a resin tube member in which an outer cylinder is placed on the outer peripheral side of the tube body and end faces are positioned on substantially the same plane so as not to cause a step on the inner surface and fixed by welding. We made two.
These resin tube members were butted against each other at the ends and welded to each other to be connected. Here, the heating time at the time of end welding was 80 sec, and the pushing amount was 1.0 mm. As a result of confirming the connecting portion after the end welding, as shown in FIG. 7 (b), an upright inner bead having a size of 1.5 mm was formed inward in the radial direction.

As an example of the invention 1, the outer cylinder is welded and fixed to the outer peripheral side of the tube body in the same manner as in the comparative example, and then the end portions of the main body of the tube body are cut and processed so as to be recessed by 0.5 mm in the axial direction. As shown in (a), two resin tube members were produced in which an inner surface step between the inner surface of the outer cylinder end portion and the inner surface of the main body end portion was formed.
Under the same conditions as in the comparative example, these resin tube members were butted against each other at the ends and welded to each other to be connected. When the connecting portion after the end welding was confirmed, the inner bead was not formed as shown in FIG. 8 (b). Although some grooves were confirmed on the inner surface of the connecting portion, it is considered that such grooves can be eliminated by adjusting the conditions at the time of end welding such as the amount of pushing.

As an example of the invention 2, after welding and fixing the outer cylinder to the outer peripheral side of the tube body in the same manner as in the comparative example, for one of them, the end of the main body of the tube body is cut so as to be recessed by 1 mm in the axial direction, and the other. For those of the above, taper cuts are made on the end faces so that the inclination angle with respect to the plane orthogonal to the axial direction is 10 °, and as shown in FIG. 9A, each of the outer cylinder end portions. Two resin tube members having an inner surface step formed between the inner surface and the inner surface of the end of the main body were produced.
Under the same conditions as in the comparative example, these resin tube members were butted against each other at the ends and welded to each other to be connected. When the connecting portion after the end welding was confirmed, the inner bead was not formed as shown in FIG. 9 (b). Also in this Invention Example 2, some grooves were confirmed on the inner surface of the connecting portion.

Based on the above, according to the present invention, when a resin tube member is welded to a resin pipe joint or another resin tube member at an end portion, generation of an inner bead at a connecting portion which is a welded portion is effectively suppressed. It turned out that it could be done.

1 Resin tube member 2 Tube body 2a Body end 3 Outer cylinder 3a, 33a, 43a Outer cylinder end 3b, 33b, 43b Outer cylinder end end surface 4 Inner surface step 34, 44 Outer surface step 5 Diameter expansion space 46 Inner recess 11 Resin pipe joint 11a Joint end 11b End face 12 Inner surface step 21 Resin part P Internal flow path AD Axial direction θ Tapered end face inclination angle Dc Outer cylinder inner diameter Dt Tube body inner diameter Hs Inner surface step radial height Lc Extension length of the outer cylinder end in the axial direction Cp Connection point

Claims (13)

A tube body in which an internal flow path through which a fluid flows is formed, and an outer side fixed or fixed to the tube body by being arranged so as to cover at least the periphery of the end of the tube body on the outer peripheral side of the tube body. Has a tube and
The outer cylinder end portion welded to the end portion of another resin tube member or resin pipe joint is located so as to protrude outward in the axial direction from the main body end portion on the inner peripheral side thereof, and is located on the inner surface of the outer cylinder end portion. An inner surface step formed by the inner surface of the main body and the inner surface of the main body is provided.
A resin tube member having a tapered shape in which the end surface of the outer cylinder end portion gradually inclines inward in the axial direction toward the inside in the radial direction. The resin tube member according to claim 1, wherein the outer cylinder is welded to the tube body. The resin tube member according to claim 2, wherein the outer cylinder is formed by welding to the tube body by insert molding. The resin tube member according to any one of claims 1 to 3, wherein the height of the inner surface step in the radial direction is 0.5 mm to 1.5 mm. The resin tube member according to any one of claims 1 to 4, wherein the protrusion length of the outer cylinder end portion in the axial direction with respect to the main body end portion of the tube main body is 0.2 mm to 1.0 mm. The resin tube member according to any one of claims 1 to 5, wherein the inclination angle of the end face of the tapered shape is within a range of 5 ° to 10 ° with respect to a plane orthogonal to the axial direction. The resin tube member according to any one of claims 1 to 6, wherein the end surface of the outer cylinder end portion has an area at least twice that of the end surface of the main body end portion of the tube body. The method for manufacturing a resin tube member according to any one of claims 1 to 7, wherein at least the end of the tube body is arranged in an injection molding die, and the resin is formed in the injection molding die. A method for manufacturing a resin tube member, which comprises an outer cylinder molding step of forming an outer cylinder on the outer peripheral side of the tube body by injecting a material. The method for manufacturing a resin tube member according to claim 8, further comprising a main body molding step of forming a tube main body by extrusion molding prior to the outer cylinder molding step. A resin pipe fitting that is connected to the resin tube member according to any one of claims 1 to 7 by welding the ends thereof, and is welded to the outer cylinder end portion of the resin tube member. A resin pipe joint with an inner step at the end. The resin pipe joint according to claim 10, wherein the height of the inner surface step at the end of the joint in the radial direction is 0.5 mm to 1.5 mm. The end face of the joint end has a tapered shape that gradually inclines inward in the axial direction toward the inside in the radial direction, and the inclination angle of the end face of the tapered shape is a plane orthogonal to the axial direction. The resin pipe joint according to claim 10 or 11, which is in the range of 5 ° to 10 °. A resin pipe including at least one resin tube member according to any one of claims 1 to 7.
At least a part of the inner surface step inside the connecting point between the resin tube member and another resin tube member or the resin pipe joint and / or the connecting point between the resin tube members is the outer cylinder. A resin pipe filled with a resin portion at an end, wherein the connecting portion has an inner diameter equal to or larger than the inner diameter of the tube body.

Images