JP2020015226A - Method for manufacturing resin tube member - Google Patents

Abstract

To provide a method for manufacturing a resin tube member that can effectively manufacture various resin tube members having different tube lengths, each of which has a connection part used for connection with a piping member.SOLUTION: A method for producing a resin tube member 1 of the present invention is a method for producing a resin tube member 1 having a tube part 2 having an internal passage IP, and a connection part 3 provided at an end 2a of the tube part 2 and used for connection with a piping member 21. The method for producing the resin tube member 1 includes an end heating step of heating an end 32a of a resin-made tube material 32, and an insert molding step of forming the connection part 3 at the end 32a of the tube material 32 that becomes the tube part 2 by injecting a resin material to the end 32a of the tube material 32 heated in the end heating step. The connection part 3 formed in the insert molding step includes a sleeve part 4 surrounding the end 2a of the tube part 2 from an outer peripheral side, and a tip end projection 5 that protrudes from the end 2a toward a tip end side continuously with the sleeve part 4.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a resin tube member having a connection portion used for connection with a piping member at an end of a tube portion, and in particular, various resin tube members having different tube lengths. It is intended to propose a technology that can effectively manufacture the.

  This kind of resin tube member is connected to another pipe member such as a resin pipe joint, and can constitute a part of a pipe through which a chemical solution or other fluid flows inside, and as an example, There is one described in Patent Document 1.

FIGS. 1 and 2 of Patent Literature 1 state that “the outer circumference of one end 21 a of a resin tube member 21 inserted into the through passage 23 of the joint body 20 is connected to the male screw 26 of the socket 24 of the union nut 22. An annular seal portion 30 having a bulging portion 31 that comes into close contact with the inlet-side seal portion 25 due to the tightening action and a fitting convex portion 32 that comes into close contact with the inner-side seal portion 27 are integrally formed of resin. "Molded resin-type pipe joint structure". In this “fusion-type resin pipe joint structure”, “the other end 21b of the tube member 21 is a fusion-bonded portion that abuts and fuses with the end of another resin-made tube member 38”. ing.
According to such a “fusion-type resin pipe joint structure”, “a swelling portion which comes into close contact with the inlet side seal portion of the joint body by tightening the union nut, An annular seal portion having a fitting convex portion which comes into close contact with the tubular member is integrally formed on a part of the outer periphery of the tube member so that no gap is formed between the outer periphery of the tube member and the annular seal portion. However, the problem of fluid accumulation as in the conventional resin pipe joint structure described above is eliminated, and the obstacle to the purification of fluid can be eliminated. "

  In addition, as a technique of insert molding with respect to a resin tube member, there are techniques described in Patent Documents 2 and 3, and the like.

JP 2005-291500 A JP 2007-196638 A Japanese Patent No. 4424137

  Patent Literature 1 relates to the manufacture of the “tube member 21” of the “fusion-type resin pipe joint structure”. “The tube member 21 is formed by integrally resin-molding an annular seal portion 30 around the outer periphery of one end 21a thereof. ", A pair of tube members having a left-right symmetrical annular seal portion is formed, and after forming, a central portion of the tube member is cut to obtain two tube members of required shapes. It is described. In addition, Patent Document 1 states that “the annular seal portion 30 that comes into close contact with the inlet-side seal portion 25 and the inner-side seal portion 27 of the joint body 20 by tightening the union nut 22 is integrally formed on the outer periphery of the tube member 21. Since there is no gap formed between the tube member 21 and the tube member 21, it is possible to solve the problem of fluid accumulation as in the above-described conventional resin pipe joint structure, which contributes to high purity fluid. Can be done. "

By the way, in the case of piping that is required to have various different shapes depending on the installation location, the manner of feeding the fluid, and the like, it may be necessary to use various resin tube members having different tube lengths.
Here, when the entirety of the resin tube member as described in Patent Document 1 is molded at once by injection molding or the like, a longer tube length than that is described in Patent Document 1. As described above, the end of another resin tube member is butted and welded to the other end of the resin tube member opposite to the one end provided with the connection portion used for connection with the piping member. Cost.

  However, when the end of the other resin tube member is welded to the other end in this way, a large inner bead that bulges in an annular shape on the inner circumferential side is easily formed on the inner circumferential surface of the welded portion, This causes the chemical solution to remain due to the liquid pool and an increase in pressure loss due to the flow resistance. Therefore, the above-described method of manufacturing a resin tube member having a connection portion at an end thereof can easily meet various demands for various resin tube members having different tube lengths while ensuring good fluidity. It is hard to say that it can respond to.

  Here, Patent Documents 2 and 3 do not specifically describe how to manufacture a resin tube member having a connection portion having a predetermined shape at an end. Further, these Patent Documents 2 and 3 focus on improving the sealing property by insert molding, and do not pay any attention to manufacturing resin tube members having different tube lengths.

  An object of the present invention is to solve such a problem, and an object of the present invention is to provide a resin tube member provided with a connection portion used for connection with a pipe member, and various resin tubes having different tube lengths. It is an object of the present invention to provide a method for manufacturing a resin tube member that can effectively manufacture a tube member.

  According to a method of manufacturing a resin tube member of the present invention, a resin tube member including a tube portion having an internal passage and a connection portion provided at an end of the tube portion and used for connection with a piping member is manufactured. In a method, an end heating step of heating an end of a resin tube material, and injecting a resin material toward the end of the tube material heated in the end heating step, to the tube portion An insert molding step of forming the connection portion at the end of the tube material, wherein the connection portion formed in the insert molding step surrounds a periphery of the end of the tube portion from an outer peripheral side; And a front end protruding portion that protrudes further to the front end side than the end portion.

  In the method for manufacturing a resin-made tube member according to the present invention, in the insert molding step, a core pin is inserted from the end side into the tube material, and the outside of the end portion of the tube material is injected into an injection mold. A resin material is injected toward the cavity including the periphery of the core pin exposed portion located at the position, and the distal end protruding portion is formed around the core pin exposed portion, and the connection portion is located on the distal end side with respect to the end portion. It is preferable to have the front end protruding portion formed by partitioning the passage.

  Further, in the method for manufacturing a resin tube member according to the present invention, the resin tube member defines an internal passage by an inner peripheral surface of the tube portion and an inner peripheral surface of the tip protrusion, and an inner peripheral surface of the tube portion. It is preferable to have a constant inner diameter from to the inner peripheral surface of the tip protrusion.

The method of manufacturing a resin tube member according to the present invention may further include an end processing step of processing an end of the tube material before the end heating step.
In the above-mentioned end processing step, the thickness of the end of the tube material can be reduced and / or a groove can be formed on the outer peripheral surface of the end.
When the thickness of the end of the tube material is reduced in the end processing step, it is preferable that the outer peripheral surface of the end be tapered toward the distal end.

  By the way, in the method of manufacturing a resin tube member according to the present invention, it is preferable that an end surface of the connection portion on the sleeve portion side is a smooth surface.

  Further, in the method of manufacturing a resin tube member according to the present invention, the resin tube member has a constant outer diameter at the tube portion and an outer diameter larger than the tube portion at the connection portion. The outer peripheral surface is connected to a large-diameter region in which the outer diameter is constant while forming an angle with the end surface on the sleeve portion side, a tapered region in which the outer diameter gradually decreases from the large-diameter region toward the distal end, and the tapered region. It is preferable that the outer diameter is constant and is formed in a small diameter area smaller than the large diameter area.

  Further, in the method of manufacturing a resin tube member according to the present invention, the distal end protruding portion of the connection portion has an outer peripheral protruding portion that protrudes to the distal end side over the entire circumference on an outer peripheral side portion of the end face on the distal end protruding portion side. In addition, it is preferable that an annular concave portion that is more concave than the outer peripheral convex portion and the inner peripheral edge portion is provided on a portion of the end face closer to the inner peripheral side than the outer peripheral convex portion.

  According to the method for manufacturing a resin tube member of the present invention, the method further includes an insert molding step of injecting a resin material into an end of the tube material heated in the end heating step and forming the connection portion at the end. Thereby, a connection portion of a predetermined shape can be formed at the end of the resin tube member, and by appropriately changing the tube length of the tube material, resin tube members having different tube lengths can be effectively used. Can be manufactured.

It is a longitudinal section containing the central axis which shows the example of the resin tube member manufactured by the method of one embodiment of this invention. FIG. 2 is a longitudinal sectional view including a center axis, showing a connection structure between a resin tube member and a resin pipe joint of FIG. 1. FIG. 3 is a side view of the connection structure of FIG. 2. FIG. 3 is a front view of the connection structure of FIG. 2. It is a longitudinal section containing the central axis which shows other examples of a resin tube member. It is a flow figure showing the manufacturing method of the resin tube member concerning one embodiment of this invention. FIG. 7 is a longitudinal sectional view showing a tube material used in the manufacturing method of FIG. 6 and including a central axis. It is an expanded longitudinal section of the end which shows the example of the processing which can be performed to the end of the tube material in the end processing step. It is a longitudinal cross-sectional view which shows the tube material which inserted the core pin inside in the insert molding process in the state arrange | positioned in the injection molding die. FIG. 2 is an enlarged longitudinal sectional view showing a main part of the resin tube member of FIG. 1.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
A resin tube member 1 illustrated in FIG. 1 includes a circular or other tubular tube portion 2 having an internal passage IP, and at least one end of both ends 2a and 2b of the tube portion 2, in this example, one end. A connecting portion 3 which is provided integrally with the end portion 2a only and has a larger outer diameter than the tube portion 2. The connecting portion 3 is connected to a piping member such as a resin pipe joint as described later. Used for connection.

  The connection portion 3 of the resin tube member 1 is located on the inner side in the axial direction of the central axis Ct with respect to the end surface 2c of the end portion 2a of the tube portion 2, and substantially surrounds the periphery of the end portion 2a from the outer peripheral side. The sleeve portion 4 has a shape such as a shape, and a distal end protruding portion 5 which is located outside the end surface 2c in the axial direction and protrudes from the end portion 2a to the distal end side continuously with the sleeve portion 4.

In this embodiment, the distal projecting portion 5 of the connecting portion 3 is provided such that its inner peripheral surface faces the internal passage IP, whereby the distal end of the internal passage IP is located closer to the distal end than the end 2 a of the tube portion 2. , More specifically, a portion outside the end face 2c in the axial direction is formed inside.
Therefore, in the resin tube member 1 of this embodiment, the internal passage IP is defined by the inner peripheral surface of the tube portion 2 and the inner peripheral surface of the distal end protruding portion 5 of the connection portion 3.

  As shown in FIGS. 2 to 4, the resin tube member 1 shown in the drawing is formed by a nut member 11 at an end 2 a of the tube portion 2 provided with the connection portion 3, by using a resin pipe joint 21 as an example of a pipe member. Connected to the joint end 21a.

Here, as shown in FIG. 2, on the outer surface of the joint end portion 21a of the resin pipe joint 21, a male screw portion 22 formed of a spiral groove extending in the axial direction while being wound in the circumferential direction is formed. Further, a female screw portion 12 composed of a spiral groove corresponding to the male screw portion 22 is formed on the inner surface of one end side (the right side in FIG. 2) of the nut member 11 in the axial direction. When the female screw portion 12 is screwed into the male screw portion 22, the inner surface of the nut member 11 is screwed to the outer surface of the joint end 21a.
Here, an annular inward flange 13 extending toward the inner peripheral side over the entire circumference is provided at the other end (left side in FIG. 2) of the nut member 11 in the axial direction.

  In order to connect the resin-made tube member 1 and the resin-made pipe joint 21 with the connection structure shown in FIG. 2, the end 2a of the tube portion 2 of the resin-made tube member 1 is provided at the end 2a. It is inserted together with the connection portion 3 inside the joint end portion 21a of the resin pipe joint 21. In this state, the nut member 11 is connected to the connection portion 3 so that the connection portion 3 of the resin tube member 1 and the joint end 21a of the resin pipe joint 21 are surrounded by the nut member 11 from the outer peripheral side. While being arranged around the joint end 21a, the female thread 12 of the nut member 11 is screwed into the male thread 22 of the joint end 21a, and they are screwed together.

  As a result, as the nut member 11 is tightened into the joint end portion 21a, the end surface 3b of the connection portion 3 of the resin tube member 1 on the sleeve portion 4 side is connected to the joint end portion 21a by the inward flange 13 of the nut member 11. While the connection portion 3 of the resin tube member 1 is pushed into the inside of the joint end portion 21a, the portion of the sleeve portion 4 mainly having a large outer diameter is formed between the inward flange 13 and the joint end portion 21a. It is sandwiched between. At this time, the pressing force acting on the resin tube member 1 in the direction of entering the joint end portion 21a presses the distal end protruding portion 5 against the inner surface of the joint end portion 21a, and forms a seal there. The resin-made tube member 1 and the resin-made pipe joint 21 can be connected in a liquid-tight or air-tight manner.

In the resin tube member 1 connected to the resin pipe joint 21 in this manner, a large force acts on the distal end protruding portion 5 pressed against the inner surface of the joint end portion 21a at the time of the connection.
In the illustrated resin tube member 1, as described above, the tube portion 2 is terminated before the end surface 3 a without reaching the end surface 3 a of the connection portion 3, and the distal end of the connection portion 3 protrudes there. A part 5 is provided, and the tip projecting part 5 defines a part of the internal passage IP. Thus, even if a large force acts on the distal end protruding portion 5 during connection with the resin-made pipe joint 21, as described later, the connecting portion 3 formed in an insert molding step separately from the tube portion 2, 2 is more effectively secured.

  On the other hand, as shown in FIG. 5, the tube portion 52 reaches the end surface 53 a of the connection portion 53 on the tip projecting portion 55 side, so that the internal passage IP is formed only on the inner peripheral surface of the tube portion 52. The tube member 51 may be used. In this case, the boundary between the connection portion 53 and the tube portion 52 is located on the end face 53a of the connection portion 53 on the side of the tip protrusion 55. The resin tube member 51 shown in FIG. 5 is substantially the same as the resin tube member shown in FIG. 1 except that the tube portion 52 reaches the end surface 53 a of the connection portion 53 on the side of the tip protrusion 55. It has a structure of.

When the resin-made tube member 1 shown in FIG. 1 is manufactured, for example, the respective steps shown in FIG. 6 can be performed.
First, a resin tube material 32 having a tubular shape such as a circular tube as shown in FIG. 7 is prepared. The tube material 32 may be prepared by purchase or some other method, or may be formed by extrusion in an extrusion process. Therefore, the embodiment of the present invention can include an extrusion molding step for obtaining the tube material 32, and the tube material 32 obtained in the extrusion molding step can be cut into a predetermined length as necessary. it can. Alternatively, the tube material 32 can be formed by injection molding instead of extrusion molding. Therefore, this extrusion step may not always be necessary.

  Examples of the resin material constituting the tube material 32 include perfluoroalkoxyalkane (PFA), perfluoroethylene propene copolymer (FEP), and polyetheretherketone (PEEK). It is also possible to use other than these. The connection portion 3 formed in an insert molding step described later can also be made of the same resin material, and preferably uses the same resin material as the tube material 32.

  An end processing step can be performed on the tube material 32 before the end heating step, if necessary. In the end processing step, the end 32a of the tube material 32 to be heated in the end heating step is pre-processed to reduce the thickness of the end 32a of the tube material 32 as shown in FIG. Alternatively, as shown in FIG. 8B, a groove 34 is formed on the outer peripheral surface of the end 32a, or both of them are performed.

When the thickness of the end 32a of the tube material 32 is reduced, the end 32a has a tapered outer surface 33 that tapers toward the distal end by cutting the outer surface. Can be. The groove 34 formed on the outer peripheral surface of the end portion 32a may be, for example, one or more grooves 34 extending along the entire circumference, if necessary, along at least a part of the circumferential direction.
By performing the end processing step, the end 32a of the tube material 32 is easily heated in the subsequent end heating step. However, this end processing step can be omitted.

Then, an end heating step of heating the end 32a of the tube material 32 is performed. In the end heating step, for example, a heating device (not shown) is used to heat the end 32a of the tube material 32 so that the end 32a of the tube material 32 placed in the injection molding die in a later insert molding step is in a semi-molten state. And heats the end portion 32a therein. By performing the insert molding step after the end heating step, the connecting portion 3 formed in the insert molding step is firmly integrated with the end 32 a of the tube material 32.
In the end heating step, the end 32a of the tube material 32 can be heated to a temperature of, for example, 250 ° C. to 350 ° C., depending on the type of the resin material constituting the tube material 32 and other conditions.

  Thereafter, an insert molding step is performed. Here, as illustrated in FIG. 9, a core pin 41 is inserted into the tube material 32 from the side of the end 32a heated in the end heating step, and in this state, the tube material 32 is inserted into an injection mold 42. Place within.

  At this time, the core pin 41 is disposed inside the tube material 32 so that a part thereof is located outside the end 32a of the tube material 32, and the core pin 41 is separated from the tube material 32 outside the end 32a of the tube material 32. A cavity 43 is defined between the exposed core pin exposed portion 41a and the inner surface of the injection mold 42. By injecting the resin material into the cavity 43, a portion corresponding to the sleeve portion 4 surrounding the end from the outer peripheral side is formed around the end 32 a of the tube material 32 in the cavity 43, and the cavity 43 is formed. Inside the core pin exposed portion 41a, a portion corresponding to the distal end protruding portion 5 that defines the internal passage IP on the distal side with respect to the end portion 32a is formed. As a result, the connecting portion 3 having the sleeve portion 4 and the distal end protruding portion 5 can be formed at the end 32a of the tube material 32. In the resin tube member 1 manufactured in this manner, the tube material 32 becomes the tube portion 2.

In such a manufacturing method, the tube length of the resin-made tube member 1 is appropriately changed according to the tube length of the resin-made tube member 1 to be manufactured. Requests for changes can be easily accommodated. In this case, there is no need to subsequently weld another resin tube member to make up for the insufficient length, so that there is no possibility of causing a problem regarding fluidity of the fluid accompanying the generation of the inner bead at the welding location. .
Therefore, according to the above-described manufacturing method, resin tube members having different tube lengths can be effectively manufactured.

  The resin tube member 1 manufactured as described above has an outer diameter of the core pin 41 inserted into the end 32 a of the tube material 32 substantially equal to an inner diameter of the tube material 32, so that the inside of the tube portion 2 can be formed. It is possible to have a constant inner diameter from the peripheral surface to the inner peripheral surface of the tip projecting portion 5. Such a resin tube member 1 having a constant inner diameter is advantageous since a liquid or the like can flow smoothly through a pipe constructed using the same.

  In the illustrated resin tube member 1, the boundary between the tube portion 2 and the connection portion 3 is clearly shown and these are clearly distinguished for easy understanding. In the case where the tube part 2 and the connection part 3 are integrated, usually they cannot be substantially distinguished due to being integrated.

  In such a resin tube member 1, the end surface 3b of the connection portion 3 on the side of the sleeve portion 4 is a smooth and smooth surface having no irregularities as shown in the figure, and the nut member 11 is brought into contact with the end surface 3b in correspondence with this. It is preferable that the inner surface of the inward flange 13 has a similar smooth surface. Further, it is preferable that the end face 3b of the connecting portion 3 and the inner face of the inward flange 13 are planes perpendicular to the central axis Ct. According to this, the resin tube member 1 is firmly held by the nut member 11.

  Here, as shown in FIG. 2, the inner peripheral surface of the inward flange 13 of the nut member 11 facing inward in the radial direction is positioned at a position away from the joint end 21 a from the connection portion 3 in the axial direction, and 2 is in surface contact over the entire circumference. In this case, the radial displacement of the resin tube member 1, which may be subjected to a radial force during use, is effectively restrained by the nut member 11, and the expected displacement at the tip protrusion 5 is obtained. Sealing property can be ensured.

The tube portion 2 of the resin tube member 1 has a constant outer diameter, while the connecting portion 3 has a larger outer diameter than the tube portion 2 in the middle.
More specifically, as shown in an enlarged view in FIG. 10, the outer peripheral surface of the connection portion 3 forms an angle such as a right angle with the end surface 3b on the side of the sleeve portion 4 and has a constant outer diameter, and a large-diameter region AL. The outer diameter is gradually reduced linearly or the like in the illustrated longitudinal section from the large-diameter region AL toward the distal end side (the right side in FIG. 10). And a small-diameter region AS having a small and constant outer diameter.
At the time of connection with the joint end portion 21a of the resin-made pipe joint 21 described above, the entire small-diameter region AS on the outer peripheral surface of the connection portion 3 enters the inside of the joint end portion 21a, and the joint end portion 21a has a tapered region AT. Abuts the corresponding tapered inner surface. Further, here, the inward flange 13 of the nut member 11 is arranged at a position adjacent to the large diameter area AL on the outer peripheral surface of the connection portion 3, and the end surface 3 b of the connection portion 3 on the sleeve portion 4 side and the inward flange 13 are formed. The inner surface, the outer peripheral surface of the tube portion 2 and the inner peripheral surface of the inward flange 13 are in surface contact with each other.

Further, the end protruding portion 5 of the connecting portion 3 of the resin tube member 1 is fitted into the inner surface of the joint end 21a having a shape corresponding to the end surface 3a on the end protruding portion 5 side, and the joint end 21a A seal structure is formed between the inner surface and the inner surface.
The end face 3a of the connecting portion 3 on the side of the tip protruding portion 5 will be described in detail. As shown in FIG. 10, the tip protruding portion 5 has a cylindrical shape protruding to the tip side over the entire outer circumference of the end face 3a. And the like. The distal end side of the small diameter region AS on the outer peripheral surface of the connection portion 3 is the outer peripheral surface of the outer peripheral convex portion 6. Further, between the inner peripheral edge portion 7 of the end face 3a on the inner peripheral side of the outer peripheral convex portion 6 and the inner peripheral edge portion 7 located on the innermost peripheral side of the end face 3a, the outer peripheral convex portion 6 and the inner peripheral edge portion 7 An annular concave portion 8 that is depressed inward in the axial direction is formed. In the longitudinal section shown in FIG. 10, the annular concave portion 8 recedes linearly inward in the axial direction from the inner peripheral edge portion 7 toward the outer peripheral side, and the deepest portion is a curved surface. The inner surface of the joint end portion 21a has a shape corresponding to the end surface 3a on the tip projecting portion 5 side, and the end surface 3a provided with the outer peripheral convex portion 6 and the annular concave portion 8 is fitted in substantially aligned manner. A double seal can be realized by pressing in the axial direction and press-fitting in the radial direction.

  The inner diameter of the joint end portion 21a can be made equal to the inner diameter of the tube portion 2 of the resin tube member 1 and the inner diameter of the tip projecting portion 5, thereby achieving a smooth flow of liquid or the like flowing therethrough. Is done.

1, 51 Resin tube member 2, 52 Tube portion 2a, 2b, 52a, 52b End portion of tube portion 2c, 52c End surface of tube portion 3, 53 Connection portion 3a, 53a End surface 3b of the connection portion at the tip end protruding portion side, 53b End face on the sleeve side of connection portion 4, 54 Sleeve 5, 55 Tip protruding portion 6 Outer peripheral protruding portion 7 Inner peripheral edge 8 Annular concave portion 11 Nut member 12 Female thread portion 13 Inward flange 21 Resin pipe joint (pipe member)
21a Joint end 22 Male thread 32 Tube material 32a, 32b Tube material end 33 Tapered outer surface 34 Groove 41 Core pin 41a Core pin exposed portion 42 Injection mold 43 Cavity Ct Center axis IP Internal passage

Claims (9)

A method of manufacturing a resin-made tube member including a tube portion having an internal passage and a connection portion provided at an end of the tube portion and used for connection with a piping member,
An end heating step of heating the end of the resin-made tube material, and injecting a resin material toward the end of the tube material heated in the end heating step, the tube material becoming the tube portion Including an insert molding step of forming the connection portion at an end,
The connecting portion formed in the insert molding step includes a sleeve portion surrounding the periphery of the end portion of the tube portion from the outer peripheral side, and a tip projecting portion projecting from the end portion to the tip side continuously with the sleeve portion. A method for manufacturing a resin tube member. In the insert molding step, a core pin is inserted from the end side into the tube material, and in an injection mold, a cavity including a periphery of the core pin exposed portion located outside the end of the tube material is inserted into a cavity. Aiming at, injecting a resin material, forming the tip protrusion around the core pin exposed portion,
The method of manufacturing a resin tube member according to claim 1, wherein the connection portion has the distal end protruding portion formed by partitioning an internal passage closer to the distal end side than the end portion.   A resin tube member defines an internal passage with an inner peripheral surface of the tube portion and an inner peripheral surface of the distal end protrusion, and has a constant inner diameter from the inner peripheral surface of the tube portion to the inner peripheral surface of the distal end protrusion. The method for producing a resin-made tube member according to claim 2.   The method of manufacturing a resin tube member according to any one of claims 1 to 3, further comprising an end processing step of processing an end of the tube material before the end heating step.   The method of manufacturing a resin tube member according to claim 4, wherein in the end processing step, a thickness of an end of the tube material is reduced and / or a groove is formed on an outer peripheral surface of the end.   6. The manufacturing of the resin tube member according to claim 5, wherein in the end processing step, the thickness of the end of the tube material is reduced, and the outer peripheral surface of the end is tapered toward the front end. Method.   The method for manufacturing a resin tube member according to any one of claims 1 to 6, wherein an end surface of the connection portion on the sleeve portion side is a smooth surface. The resin-made tube member has a constant outer diameter at the tube portion, and has a larger outer diameter than the tube portion at the connection portion,
An outer peripheral surface of the connection portion, a large-diameter region that forms an angle with the end surface on the sleeve portion side and has a constant outer diameter, a tapered region in which the outer diameter gradually decreases from the large-diameter region toward the distal end, and The method for manufacturing a resin tube member according to any one of claims 1 to 7, wherein the resin tube member is formed in a small-diameter region that is connected to the tapered region and has a constant outer diameter and is smaller than the large-diameter region.   The distal projection of the connection portion has an outer peripheral projection on the outer peripheral portion of the end surface on the distal projection side, and an outer peripheral projection protruding toward the distal end over the entire circumference, and a more inner peripheral portion of the end surface than the outer peripheral projection. The method for manufacturing a resin-made tube member according to any one of claims 1 to 8, further comprising an annular concave portion depressed from the outer peripheral convex portion and the inner peripheral edge portion.

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