TWI736767B - Resin pipe member, method of manufacturing resin pipe member, resin pipe joint, and resin pipe - Google Patents

Abstract

The resin pipe member (1) of the present invention has: a pipe body (2) having an internal flow path (P) for fluid to flow inside; The outer peripheral side is arranged to cover at least the body end (2a) of the pipe body (2), and is fixed or fixed to the pipe body (2); welded to the end of other resin pipe members or resin pipe joints The outer cylinder end (3a) is positioned to protrude to the outer side of the axial direction (AD) than the above-mentioned body end (2a) on the inner peripheral side, and is provided with the inner surface of the outer cylinder end (3a) and The inner surface step (4) formed by the inner surface of the body end (2a).

Description

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

The present invention relates to a method for manufacturing a resin pipe member and a resin pipe member in which an internal flow path for fluid flow is formed and the ends are welded to connect with a resin pipe joint or other resin pipe members , Resin pipe joints and resin piping, in particular, proposes a technology that can effectively suppress the so-called internal protrusion that may occur when the resin pipe member is welded to the resin pipe joint or other resin pipe members at the end.

Resin pipes such as chemical liquid delivery lines used in various industries are sometimes manufactured by using a welding machine to connect each end of a resin pipe joint or a resin pipe member made of thermoplastic resin, etc. Manufactured by welding each other to the ground.

To explain in detail an example of the manufacturing method of such a resin pipe, for example, in each of the paired clamps of the welding machine, the two resin pipe members or resin pipe joints are mutually connected with each other. Maintain the facing posture. Then, the ends of the two resin pipe members and the like held in each jig are heated by a heater or the like to melt the ends of the two resin pipes. In this state, the two resin pipes are heated. The components are close to each other, so that the end is welded to the ground by the required pressure. By repeating the welding of the ends of such a resin pipe member and the like to connect the resin pipe member and the like, a pipe of a specific shape can be manufactured.

Here, in order to obtain sufficient welding strength for connecting resin pipe members or resin pipe members and other resin pipe joints in the above manner, it is necessary to heat the ends at a specific higher temperature before welding the ends. After the ends are butted with each other, a specific greater pressure is applied.

However, in this case, due to such heating and pressurization, the flow of the molten resin is generated at the end of the molten state during the butting. Therefore, there are cases where the resin moves to the inner peripheral side than the inner surface. The raised state is hardened, and a raised portion is formed on the inner surface of the welded part. This bulge is sometimes referred to as an inner bulge. Moreover, since the inner protrusion formed on the inner surface of the welded portion of the pipe partially narrows the inner diameter of the pipe, there is a problem that liquid accumulates there and reduces the flow rate when the liquid flows.

In response to this problem, Patent Document 1 proposes a "method for welding synthetic resin tubular members to each other", which is to heat and melt the ends of the first and second synthetic resin tubular members, and then make the end faces face each other. The method of welding, and applying internal pressure to the two tubular members during the butting", "before heating, chamfer the inner diameter of the butt ends of the two tubular members". Moreover, according to this method, "the amount of protrusion existing on the inner surface of the protrusion of the butt portion can be reduced, and by using the thus obtained tubular member for piping, the joint portion does not hinder the smooth flow of the liquid, and also Prevent the junction from becoming effluent and prolong the time required for liquid replacement."

[Prior Technical Literature]

[Patent Literature]

[Patent Document 1] JP 2004-284048 A

In the technique disclosed in Patent Document 1, internal pressure is applied when the ends of resin pipe members and the like are welded to each other. Therefore, there are other problems in that a welding machine and pressure for applying the internal pressure are required. Device, thereby increasing equipment cost, and leading to an increase in working time due to pressurization. In particular, when a plurality of resin pipe members or resin pipe joints are connected in sequence to form a pipe, a pressurizing device must be installed every time the ends of the pipe are welded to each other. It is undeniable that the manufacturing efficiency of the pipe is reduced. .

The subject of the present invention is to solve such problems in the prior art, and its object is to provide a method that can effectively suppress the possibility of welding a resin pipe member and a resin pipe joint or other resin pipe members from being welded at the end. Resin pipe member that protrudes inside the part, method of manufacturing resin pipe member, resin pipe joint, and resin pipe.

The resin pipe member of the present invention has: a pipe body in which an internal flow path for fluid to flow is formed; and an outer cylinder arranged to cover the periphery of at least the end of the pipe body on the outer circumference of the pipe body , And fixed or fixed to the pipe body; the end of the outer tube fused to other resin pipe members or resin pipe joints protrudes to the outside of the axial direction than the end of the body on the inner circumference side. It is positioned, and is provided with an inner surface level difference formed by the inner surface of the end of the outer cylinder and the inner surface of the end of the body.

In the resin pipe member of the present invention, it is preferable that the outer cylinder is welded to the pipe body.

In this case, it is more preferable that the outer cylinder is welded and formed on the pipe body by insert molding.

Here, in the resin pipe member of the present invention, it is preferable that the height of the inner surface step difference in the radial direction is 0.5 mm to 1.5 mm.

Furthermore, here, in the resin pipe member of the present invention, it is preferable that the protruding length of the end of the outer cylinder with respect to the axial direction of the end of the pipe body is 0.2 mm to 1.0 mm.

Furthermore, in the resin pipe member of the present invention, it is preferable that the end surface of the end portion of the outer cylinder has the following tapered shape, and the inclination angle of the tapered end surface is 5° with respect to a plane orthogonal to the axial direction Within the range of ~10°, the cone shape gradually slopes toward the inner side of the axis direction as it goes toward the radial inner side.

Furthermore, in the resin pipe member of the present invention, it is preferable that the end surface of the end of the outer cylinder has an area more than twice that of the end surface of the main body end of the pipe body.

The method of manufacturing a resin pipe member of the present invention is a method of manufacturing any of the above-mentioned resin pipe members, and has an outer cylinder forming step in which at least the body end of the pipe body is arranged in an injection molding die, The resin material is injected into the injection mold, thereby forming an outer cylinder on the outer peripheral side of the pipe body.

In the method for manufacturing a resin pipe member of the present invention, it is preferable to further include a body forming step of forming the tube body by extrusion before the outer cylinder forming step.

The resin pipe joint of the present invention is connected to any one of the above-mentioned resin pipe members by welding at the end, and the joint end welded to the end of the outer cylinder of the resin pipe member is provided with an inner surface Step difference.

In the resin pipe joint of the present invention, it is preferable that the radial height of the step of the inner surface of the joint end is 0.5 mm to 1.5 mm.

In addition, in the resin pipe joint of the present invention, it is preferable that the end surface of the end of the joint has the following tapered shape, and the inclination angle of the tapered end surface is 5° to a plane orthogonal to the axial direction. Within the range of 10°, the tapered shape gradually slopes toward the inner side of the axial direction as it goes toward the radial inner side.

The resin piping of the present invention is provided with at least one of any one of the above-mentioned resin pipe members, and is used at the connection site of the above-mentioned resin pipe member and other resin pipe members or resin pipe joints, and/or the above-mentioned resin pipe member At least a part of the inner surface step is filled with the resin part of the end of the outer cylinder on the inner side of the connecting part, and the connecting part has an inner diameter equal to or larger than the inner diameter of the pipe body.

According to the present invention, the outer cylinder covering at least the end of the body is arranged on the outer circumference of the pipe body of the resin pipe member, so that the end of the outer cylinder for the welding of the end is higher than the end of the body on the inner circumference. It is positioned to protrude to the outside of the axial direction, and an inner surface level difference is provided here, so that if the end of other resin pipe members or resin pipe joints and the end of the outer cylinder are welded to the ground, the inner circumference The resin part of the side bulge is filled to at least a part of the inner surface level difference, and the bulge of the resin part to the inner peripheral side is suppressed, so the formation of the inner bulge of the welded portion can be effectively suppressed.

1‧‧‧Resin pipe components

2‧‧‧Tube body

2a‧‧‧End of body

3‧‧‧Outer cylinder

3a, 33a, 43a‧‧‧Outer cylinder end

3b, 33b, 43b‧‧‧The end surface of the end of the outer cylinder

4‧‧‧Inside level difference

34、44‧‧‧Outside step difference

5‧‧‧Expansion space

46‧‧‧Inner recess

11‧‧‧Resin pipe joint

11a‧‧‧Connector end

11b‧‧‧end face

12‧‧‧Inside level difference

21‧‧‧Resin part

P‧‧‧Internal flow path

AD‧‧‧Axis direction

θ‧‧‧The inclination angle of the end surface of the cone shape

Dc‧‧‧Inner diameter of outer cylinder

Dt‧‧‧Inner diameter of tube body

Hs‧‧‧The radial height of the inner step difference

Lc‧‧‧The protruding length of the end of the outer cylinder in the axial direction

Cp‧‧‧Connecting part

Fig. 1 is a longitudinal cross-sectional view including a central axis of a main part of a resin pipe member according to an embodiment of the present invention.

Fig. 2 is a partial enlarged longitudinal sectional view of Fig. 1.

Fig. 3 is a longitudinal sectional view showing the resin pipe member of Fig. 1 together with a resin pipe joint connected thereto.

Fig. 4 is a longitudinal cross-sectional view showing a welded part, which is a connection part between the resin pipe member and the resin pipe joint of Fig. 3.

Fig. 5 is a longitudinal sectional view showing a modification of the outer tube of the resin pipe member.

Fig. 6 is a longitudinal sectional view showing another modification of the outer tube of the resin pipe member.

Fig. 7 is a longitudinal cross-sectional view showing the resin pipe member of the comparative example in the embodiment in the state before and after the welding of the end.

Fig. 8 is a longitudinal cross-sectional view showing the resin pipe member of Invention Example 1 in the embodiment in the state before and after welding of the ends.

Fig. 9 is a longitudinal sectional view showing the resin pipe member of Invention Example 2 in the embodiment in the state before and after welding of the ends.

Hereinafter, the embodiments of the present invention will be described in detail while referring to the drawings.

The resin pipe member 1 illustrated in Fig. 1 has a straight or curved pipe body 2 in the shape of a straight pipe or a curved pipe, and an internal flow path P through which liquids such as liquid medicine or gas and other fluids flow are formed inside. And the outer cylinder 3, which covers at least the circumference of the body end 2a of the tube body 2 on the outer circumference of the tube body 2, and is fixed or fixed to the tube body 2, in a cylindrical shape such as a cylinder.

The pipe body 2 and the outer cylinder 3 constituting the resin pipe member 1 are respectively composed of resin materials such as perfluoroalkoxy alkane (PFA), perfluoroethylene propylene copolymer (FEP) or polyether ether ketone (PEEK) , And can be formed by using the same or different resin materials.

Here, in the resin pipe member 1, as shown in the enlarged view in FIG. 2, the outer cylinder end 3a of the outer cylinder 3 is more oriented than the main body end 2a of the pipe main body 2 arranged on the inner peripheral side. It is positioned in such a way that the outer side protrudes in the axial direction AD, whereby an inner surface step 4 with a height in the radial direction is formed between the inner surface of the outer cylinder end 3a and the inner surface of the main body end 2a.

In more detail, the resin pipe member 1 is the part where the pipe body 2 exists on the inner side of the axial direction AD, and has a relatively small inner diameter Dt of the pipe body 2, but in the end of the resin pipe member 1 Compared with the inner surface step 4, it is closer to the outer side of the axial direction AD, and the outer cylinder end 3a protrudes further to the outer side of the axial direction AD than the body end 2a. There is no pipe body 2, and the outer cylinder end 3a is relatively larger. The inner diameter Dc. As a result, an enlarged diameter space 5 partitioned by the inner surface step 4 and the inner surface of the outer cylinder end 3a is formed at the end of the resin pipe member 1.

In order to manufacture piping using this resin pipe member 1, the connection and/or connection of resin pipe members by welding the resin pipe member 1 and other resin pipe members or resin pipe joints at the ends are repeated Connection of resin pipe members and resin pipe joints.

Specifically, the welding of the end can be performed, for example, by using the end of the resin pipe member 1 and other resin pipe members in each of the paired clamps of the welding machine not shown in the figure. Or a posture where the ends of the resin pipe joints face each other, so that the resin pipe members 1 and the like are held separately, and then the ends of the resin pipe members 1 and the like held in the jig are held by heaters and The other heating device heats and melts the resin pipe members 1 and the like close to each other, and the ends of the resin pipe members 1 and the like are abutted by the required pressure.

Here, as shown in FIG. 3, the resin pipe member 1 is welded and connected to the joint end portion 11 a of the resin pipe joint 11 and the like at the outer cylinder end portion 3 a.

According to this situation, when the end is welded, the outer cylinder end 3a is abutted with the joint end 11a of the resin pipe joint 11 in a molten state under a specific pressure, and the resin part 21 is formed by the pressure. Flowing in the radial direction and moving to the inner peripheral side is also shown in FIG. 4, the resin portion 21 enters the enlarged diameter space 5 where the inner surface step 4 is interposed, so that the resin portion 21 is prevented from bulging to a relatively high degree. The inner surface of the internal flow path P of the pipe main body 2 which is a part of the piping is close to the inner peripheral side. Therefore, it is possible to effectively suppress the occurrence of bulge within the problem of fluid accumulation or decrease in flow rate. As a result, the heating and pressurizing conditions during welding can be set regardless of the formation of the inner protrusion, so that the ends can be welded with a sufficiently high strength.

Therefore, the resin piping manufactured in this way is located inside the connection part Cp between the resin pipe member 1 and other resin pipe members or resin pipe joints 11, or the connection part between the resin pipe members 1, as shown in the figure. As shown in 4, at least a part of the inner surface step 4 will be filled with the resin portion 21 of the outer cylinder end 3a, and it is preferable that the connecting portion Cp has an inner diameter equal to or greater than the inner diameter Dt of the pipe body 2 . That is, the inner surface of the resin pipe member 1 is designed in such a way that there is no bulge such as an inner bulge whose inner diameter is smaller than the inner diameter Dt of the pipe body 2 at the connection part Cp of the manufactured resin pipe The size and shape of the step 4 or the outer cylinder 3, the tube body 2, etc.

Specifically, when the inner diameter of the connecting portion Cp is greater than the inner diameter Dt of the pipe body 2, the difference between the inner diameter of the connecting portion Cp and the inner diameter Dt of the pipe body 2 is preferably the largest in the diameter of the connecting portion Cp The part is set to 0mm or more and 1mm or less. If the inner diameter of the connecting portion Cp is too larger than the inner diameter Dt of the pipe body 2, there is a fear of effusion.

Furthermore, here, in the embodiment shown in the figure, the outer cylinder 3 is arranged in a region covering the end portion side portion including the main body end 2a of the pipe main body 2. However, even when the outer cylinder is installed to cover the circumference of the pipe body as a whole in the axial direction, if the inner surface step is formed at the end of the outer cylinder, the above-mentioned inner protrusion suppression effect can be exerted. Therefore, the outer cylinder only needs to be arranged to cover at least the end of the main body.

The outer tube 3 is welded to the tube body 2, and is particularly preferably welded to the tube body 2 by insert molding as described below, but it is not limited to this. For example, it can also be formed on the outer tube and the tube body by the use of an adhesive. Each of them is fixed or fixed by fitting or engaging with recesses and protrusions not shown in the figure, and various other methods.

The inner surface step 4 formed by the outer cylinder end portion 3a and the main body end portion 2a has a height Hs in the radial direction of preferably 0.5 mm to 1.5 mm. When the radial height Hs of the inner step 4 is less than 0.5mm, when the outer cylinder end 3a is welded to the joint end 11a of the resin joint 11, the inner step allows the bulge of the resin part 21 The difference 4 is too small, and therefore, there is a possibility that the inner protrusion bulges toward the inner peripheral side and is formed. On the other hand, if the radial height Hs of the inner surface step 4 is greater than 1.5 mm, there is a fear of insufficient welding strength or liquid accumulation.

Moreover, the protruding length Lc of the outer cylinder end 3a with respect to the axial direction AD of the main body end 2a of the pipe main body 2 is preferably 0.2 mm to 1.0 mm, for example. The reason is that when the protruding length Lc of the outer cylinder end 3a is too long, there is a possibility of liquid accumulation. On the other hand, when the protruding length Lc is too short, it may melt to the tube during welding. The inner surface of the tube body 2 may bulge beyond the inner surface of the tube body 2.

In the resin pipe member 1 shown in the figure, the enlarged diameter space 5 formed by the inner face step 4 as described above is composed of the end face of the body end 2a parallel to the plane orthogonal to the axial direction AD, and The inner surface of the protruding part of the outer cylinder end 3a is divided to form a ring with a substantially rectangular cross-section.

Furthermore, here, the area of the end surface 3b of the outer cylinder end 3a, such as the joint end 11a of the resin pipe joint 11, is preferably the area of the end surface of the body end 2a where the inner surface step 4 is formed therebetween. More than twice the area. Thereby, it is possible to weld to the joint end portion 11a of the resin pipe joint 11 and the like sufficiently and firmly. However, if the area of the end surface 3b of the outer cylinder end portion 3a is too large, there is a fear of appearance defects such as dents, so the area of the end surface 3b of the outer cylinder end portion 3a can be set to three times the area of the end surface of the body end portion 2a or less .

In addition, in order to more effectively prevent the resin portion from bulging toward the inner periphery during welding, the end surface 3b of the outer cylinder end 3a may have a gradually deeper position as shown in the embodiment shown in the figure. A tapered shape that is inclined toward the inner side of the axis direction AD. More specifically, the inclination angle θ of the end surface 3b forming the tapered shape of the outer cylinder end 3a is preferably within a range of 5° to 10° with respect to a plane orthogonal to the axial direction AD. If the inclination angle θ of the tapered end surface 3b is less than 5°, the resin portion 21 may be excessively swelled toward the inner peripheral side, and if the inclination angle θ is greater than 10°, there may be insufficient welding. However, the tapered shape of the end surface 3b of the outer cylinder end 3a is not an essential configuration.

Furthermore, although illustration is omitted, in addition to or instead of making the end surface 3b of the outer cylinder end 3a a tapered shape, the end surface of the main body end of the pipe body may have the same tapered shape. In this case, the tapered end surface of the body end can also be inclined within a range of 5° to 10° with respect to the plane orthogonal to the axis direction.

As described above, the outer cylinder 3 and the inner surface step 4 formed therefrom are preferably formed in a resin tube from the viewpoint of effectively suppressing the generation of inner protrusions at both ends caused by welding. The ends of the member 1, but according to the shape of the end of other resin pipe members or resin pipe joints welded to each end, only any one end of the resin pipe member 1 may be formed as an outer Tube 3 and inner surface level difference 4. The same applies to the tapered shape of the end surface 3b of the outer cylinder end 3a, which can be provided at at least one end.

Furthermore, as in the modified example shown in FIG. 5, the outer surface step 34 may be provided on the outer side of the outer tube end 33a of the outer tube 33 on the outer side in the axial direction so that the outer diameter becomes smaller. The outer level difference 34 can effectively suppress the bulging of the resin portion to the outer peripheral side during welding with the joint end portion 11a of the resin pipe joint 11 and the like, so it is preferable from the viewpoint of the piping arrangement space and appearance. The size and shape of the outer step 34 can be appropriately set according to specific conditions such as the size of the end surface, but it can also be set to the same size and shape as the inner step 4.

In addition, as shown in other modifications shown in FIG. 6, the inner surface of the outer tube end 43a of the outer tube 43 may be provided on the inner surface side of the outer tube end 43a and the outer side in the axial direction. The inner side recess 46 increases the inner diameter on the outer side. Thereby, the inner protrusion can be more surely dented to the outer peripheral side than the inner surface of the tube. Even in this case, the end surface 43b of the outer cylinder end 43a is positioned to protrude further to the outside of the axial direction than the end surface of the main body end 2a of the pipe body 2, and is positioned between the inner surface of the outer cylinder end 43a and the body end 2a. The inner surface is formed between the inner surface step 4.

The formation area of the inner recess 46 in the axial direction can be set, for example, from a position 0.5 mm inward in the axial direction from the end surface of the body end 2a of the tube body 2 to a position 1.0 mm inward in the axial direction from the end surface. . In addition, the radial length of the inner concave portion 46 can be set to 0.5 mm to 1.0 mm, for example.

In addition, at the point shown in FIG. 6, the outer cylinder end 43a is provided with an outer step 44 together with the inner recess 46. Although the illustration is omitted, the outer step 44 may not be provided and only the inner recess 46 may be provided.

Preferably, in the resin pipe joint 11 connected to the resin pipe member 1 by welding the end, the joint end 11a welded to the outer cylinder end 3a of the resin pipe member 1 is also provided with resin The inner surface level difference 12 of the pipe-making member 1 is substantially the same. In this case, from the same point of view, it is preferable that the radial height of the inner surface step 12 of the joint end 11a is 0.5 mm to 1.5 mm, and it is preferable to have the following tapered shape, and The inclination angle of the tapered end surface 11b is in the range of 5°~10° with respect to the plane orthogonal to the axial direction. The tapered shape is that the end surface 11b of the joint end portion 11a gradually becomes deeper as it goes to the radially inner side. The direction of the inner side of the axis is inclined.

As the resin pipe joint 11, there are, for example, an elbow in which the internal flow path is bent into a substantially L shape, or a pipe joint in which the internal flow path is branched in the middle to form a T shape. The cross-sectional area of the internal flow path changes in the middle. The reduced diameter joints, etc.

To describe an example of the method of manufacturing the resin pipe member 1 as described above, first, the main body forming step of forming the pipe main body 2 from a specific resin material by extrusion molding or the like is performed. Here, by forming a long tubular material by extrusion molding, and cutting it into a specific length, the tube body 2 may also be formed. This cutting can be divided into, for example, a first-stage cutting that roughly cuts a long tubular material, and a second-stage cutting that is then cut to a specific length with higher precision and finishes the end surface.

Then, the following outer cylinder forming step is performed, namely, arranging at least the body end 2a of the tube body 2 in the injection molding mold, and the shape of the outer tube 3 in the injection molding mold and the outer tube 3 to be formed around the tube body 2 A resin material is injected from the cavity corresponding to the inner shape, and the resin material is cooled and hardened, and an outer cylinder 3 is formed on the outer peripheral side of the pipe body 2. By this insert molding, the outer tube 3 with a specific shape can be welded at a specific position around the tube body 2 to form it. Therefore, the outer tube 3 is formed separately and then fixed or fixed to the tube body 2 Compared with the case, it is better in terms of being easily formed in a short time.

Before the outer tube forming step of forming the outer tube 3 around the tube body 2 by insert molding as described above, a pre-heating step of heating at least the body end 2a of the tube body 2 into a semi-molten state may also be performed. Thereby, during the insert molding of the outer cylinder forming step, the tube body 2 and the outer cylinder 3 are firmly integrated. However, this pre-heating step can also be omitted.

Furthermore, here, by adjusting the cavity shape of the injection molding die, the outer tube 3 having the above-mentioned tapered shape on the end surface 3b can be molded around the pipe body 2. Alternatively, in the outer cylinder forming step, the following end processing step may also be performed, that is, the outer cylinder 3 having an end surface parallel to a plane orthogonal to the axial direction AD is temporarily formed, and the end surface is used after the outer cylinder forming step A cutter etc. process the end surface of the outer cylinder end 3a into this tapered shape.

[Example]

Next, the resin pipe member of the present invention is prototyped to confirm its performance, and the description will be given below. However, the description here is for the purpose of mere illustration, and is not intended to be limited to this.

As a comparative example, as shown in Fig. 7(a), two resin pipe members were made. The resin pipe members are made of an outer cylinder so that the end faces are located on the same plane so as not to generate a step difference in the inner surface. It is fixed to the outer peripheral side of the pipe body by welding.

These resin pipe members are welded and connected to each other at the ends. Here, the heating time at the end welding is 80 sec, and the pressing amount is 1.0 mm. The connection part after the end welding was confirmed. As shown in Fig. 7(b), an inner protrusion with a size of 1.5 mm was formed on the inner side in the radial direction.

As Inventive Example 1, two resin pipe members were produced in the same manner as in the comparative example. After the resin pipe member was welded and fixed to the outer cylinder on the outer peripheral side of the pipe body, the ends of the pipe body were respectively recessed in the axial direction. Each 0.5mm method is used for cutting, as shown in Fig. 8(a), to form a step difference between the inner surface of the end of the outer cylinder and the inner surface of the end of the body.

These resin pipe members were welded and connected to each other at the ends under the same conditions as in the comparative example. The connection part after the end welding was confirmed. As shown in Fig. 8(b), no internal protrusion was formed. In addition, several grooves were confirmed on the inner surface of the connection part, and it is considered that such grooves can be eliminated by adjusting the conditions at the time of end welding such as the amount of press-in.

As Inventive Example 2, two resin pipe members were produced in the same manner as the comparative example. The resin pipe members were welded and fixed to the outer cylinder on the outer peripheral side of the pipe body. Cutting is performed with a recessed 1mm in the axial direction. For the other, taper cutting is performed so that the end face of the other is tapered so that the inclination angle of the plane perpendicular to the axial direction becomes 10°, as shown in Figure 9(a) As shown, the inner surface level difference between the inner surface of the end of the outer cylinder and the inner surface of the end of the main body is formed respectively.

Under the same conditions as the comparative example, these resin pipe members were welded and joined to each other at the ends. After confirming the connection part after the end part was welded, as shown in Fig. 9(b), no inner protrusion was formed. In Example 2 of the present invention, several grooves were also confirmed on the inner surface of the connection part.

As described above, according to the present invention, it is understood that when a resin pipe member is welded to a resin pipe joint or other resin pipe member at the end, it is possible to effectively suppress the generation of inward protrusions at the connection portion as the weld.

Claims (13)

A resin pipe member having: a pipe body in which an internal flow path for fluid to flow is formed; and an outer tube arranged to cover at least the body end of the pipe body on the outer periphery of the pipe body , And fixed or fixed to the pipe body; the end of the outer tube fused to other resin pipe members or resin pipe joints protrudes to the outside of the axial direction than the end of the body on the inner circumference side. It is positioned and provided with an inner surface step formed by the inner surface of the end of the outer cylinder and the inner surface of the end of the main body; Incline to the direction that is deep inside the axial direction. The resin pipe member according to claim 1, wherein the outer cylinder is welded to the pipe body. The resin pipe member according to claim 2, wherein the outer cylinder is welded by insert molding and formed on the pipe body. The resin pipe member according to any one of claims 1 to 3, wherein the height of the inner surface step difference in the radial direction is 0.5 mm to 1.5 mm. The resin pipe member according to any one of claims 1 to 3, wherein the protruding length of the end of the outer cylinder with respect to the axial direction of the end of the pipe body is 0.2 mm to 1.0 mm. The resin pipe member according to any one of claims 1 to 3, wherein the inclination angle of the end surface of the tapered shape is within a range of 5° to 10° with respect to a plane orthogonal to the axial direction. The resin pipe member according to any one of claims 1 to 3, wherein the end surface of the end of the outer cylinder has an area more than twice that of the end surface of the body end of the pipe body. A method for manufacturing a resin pipe member, which is a method for manufacturing the resin pipe member according to any one of claims 1 to 7, and has an outer cylinder forming step, which is to form at least the body of the pipe body The end is arranged in the injection molding mold, and the resin material is injected into the injection molding mold In this way, an outer cylinder is formed on the outer peripheral side of the pipe body. The method for manufacturing a resin pipe member according to claim 8, which further includes a body forming step of forming the pipe body by extrusion before the outer cylinder forming step. A resin pipe joint which is connected to the resin pipe member according to any one of claims 1 to 7 by welding the end, and is welded to the end of the outer cylinder of the resin pipe member The end is provided with an inner level difference. The resin pipe joint according to claim 10, wherein the radial height of the step of the inner surface of the joint end is 0.5 mm to 1.5 mm. The resin pipe joint according to claim 10 or 11, wherein the end face of the joint end has the following tapered shape, and the inclination angle of the tapered end face is 5° to a plane orthogonal to the axial direction. Within the range of 10°, the tapered shape gradually slopes toward the inner side of the axial direction as it goes toward the radial inner side. A resin piping comprising at least one resin pipe member according to any one of claims 1 to 7, and at a connection location between the resin pipe member and other resin pipe members or resin pipe joints, and / Or the inner side of the connecting part of the resin pipe members, at least a part of the inner surface step is filled with the resin part of the outer cylinder end, and the connecting part has an inner diameter equal to or larger than the inner diameter of the pipe body The inner diameter.

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