JP2010151194A - Joint structure for tube, processing method of tube end, and processing device of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joint structure for a tube in which the tube with a barrier layer formed on its outer peripheral surface side is securely/firmly heat-welded to a joint, and the joint strength of the tube and the joint can be improved. <P>SOLUTION: An end 12 of the tube 10 has a cut peripheral surface 13 where the barrier layer 11 on the outer peripheral surface side is cut by a predetermined axial length and thermoplastic material is exposed at the cut part. With the end 12 of the tube 10 fitted into a tube end 21 of the joint 20, the cut peripheral surface 13 in the end 12 of the tube 10 and an inner peripheral surface 22 in the tube end 21 of the joint 20 also made of the thermoplastic material are mutually heat-welded and joined together. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a tube joining structure for joining a tube having a barrier layer formed on the outer peripheral surface side and a joint having a tube end portion into which the end portion of the tube is fitted.
Further, the present invention provides a tube having a barrier layer formed on the outer peripheral surface side, and has a tube end portion into which the end portion of the tube is fitted, and is joined to a joint made of a thermoplastic material like the tube main portion. The present invention relates to a processing method and a processing apparatus for the tube end.

  2. Description of the Related Art Conventionally, as a method for joining resin tubes and joints, methods of joining by heating and welding to each other using the thermoplasticity of each material have been widely used. That is, in a state where the end portion of the tube is fitted into the tube end portion of the joint, the heating member is pressed against the outer peripheral surface side of the tube end portion of the outermost joint to heat the tube, and the joint pipe overlapping in the axial direction The inner peripheral surface of the end portion and the outer peripheral surface of the end portion of the tube are bonded by heating and welding to each other.

In this way, as a joining structure of the tube heat-welded to the joint, it is possible to heat-weld and join without generating a void in the welded portion and without generating a bead bulge or a dent inside the welded portion. What can be done is known (for example, see Patent Document 1).
Also, a tube end processing apparatus is known in which the inner peripheral edge of the distal end surface at the end of the tube is chamfered so that the welding strength to the joint can be sufficiently increased (see, for example, Patent Document 2). .)

  By the way, a fluororesin is generally used as a material for tubes and joints, and in particular, a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA) is widely used. PFA is a thermoplastic fluororesin made of a copolymer of tetrafluoroethylene (TFE) and perfluoroalkoxyethylene, which has excellent chemical resistance, is thermoplastic and can be melt processed, It is a material with excellent surface smoothness.

  However, in the case of a conventional PFA tube, when a highly permeable chemical solution (hydrochloric acid, etc.) passes through the inside of the tube, cracks occur and the permeability is increased, or the light transmission is hindered by whitening. was there. In order to solve this problem, a low-permeability PFA tube with improved barrier properties against highly permeable acid is formed by forming a barrier layer made of a barrier fluoropolymer (CPT) on the outer peripheral surface side of the PFA tube. It has become popular recently.

JP 2007-239973 A Utility Model Registration No. 3092640

  In the conventional joining structure of the tube to the joint as described above and the processing device for the tube end, the end face of the tube may be chamfered, but the barrier layer on the outer peripheral surface side of the end of the tube In the state that it was left as it was, it was welded and joined to the joint.

  However, since the barrier layer in the tube is a composition different from the thermoplastic material (PFA) for forming the tube or the joint, the same material (PFA) is used due to the difference in melting temperature at the time of heat welding. ) Compared with the case of heat-welding each other, there is a problem that the welding stability is not good and the mechanical joint strength is also inferior.

  The present invention has been made paying attention to the problems of the conventional techniques as described above, and in particular, a tube having a barrier layer formed on the outer peripheral surface side is reliably and firmly heat-welded to a joint. It is an object of the present invention to provide a tube joint structure, a tube end processing method, and a processing apparatus that can improve the joint strength between the tube and the joint.

The gist of the present invention for achieving the object described above resides in the inventions of the following items.
[1] A tube (10) having a barrier layer (11) formed on the outer peripheral surface side, and a joint (20) provided with a pipe end (21) into which the end (12) of the tube (10) is fitted. In the joining structure of the tube (10) for joining each,
The end portion (12) of the tube (10) has a predetermined length in the axial direction, and the barrier layer (11) on the outer peripheral surface side is cut to a cutting circumference where a thermoplastic material is exposed at the cut portion. Having a surface (13),
The cutting peripheral surface (13) at the end (12) of the tube (10) with the end (12) of the tube (10) fitted into the pipe end (21) of the joint (20). And a joint structure of the tube (10), wherein the inner peripheral surface (22) of the pipe end portion (21) of the joint (20), which is also made of a thermoplastic material, is joined by heat welding. .

[2] A tube (10) having a barrier layer (11) formed on the outer peripheral surface side, and a joint (20) including a pipe end (21) into which the end (12) of the tube (10) is fitted. In the joining structure of the tube (10) for joining each,
The end portion (12) of the tube (10) has a predetermined length in the axial direction, and the barrier layer (11) on the outer peripheral surface side is cut to a cutting circumference where a thermoplastic material is exposed at the cut portion. A surface (13) and a separate auxiliary ring (40) to be externally fitted to the cutting peripheral surface (13),
The auxiliary ring (40) is made of the same thermoplastic material as the tube (10), and the outer peripheral surface of the auxiliary ring (40) is fitted to the outer peripheral surface of the barrier layer (11). Formed in continuous thickness,
The end (12) of the tube (10) is fitted into the pipe end (21) of the joint (20) with the auxiliary ring (40) fitted over the end (12) of the tube (10). The cutting peripheral surface (13) in the portion (12) and the inner peripheral surface (22) in the pipe end portion (21) of the joint (20) made of the same thermoplastic material are connected to the auxiliary ring (40). A joining structure of the tube (10), characterized in that the tubes (10) are joined by heating and welding.

[3] The end (12) of the tube (10) has a chamfered portion (14) having an acute cross-sectional shape in which the inner peripheral edge of the distal end surface is cut.
The pipe end part (21) of the joint (20) is bitten by the chamfered part (14) in the middle of the inner peripheral surface (22) thereof, so that the pipe end part (21) of the joint (20) The tube (10) joining structure according to [1] or [2], further comprising an encroached portion (23) for regulating a position where the end portion (12) of the tube (10) is fitted.

[4] A tube (10) having a barrier layer (11) formed on the outer peripheral surface side is provided with a tube end (21) into which the end (12) of the tube (10) is fitted, and the tube (10) A method of processing the end (12) of the tube (10) in order to join the joint (20) made of a thermoplastic material,
The barrier layer (11) on the outer peripheral surface side is cut at a predetermined length in the axial direction of the end portion (12) of the tube (10), and a thermoplastic material is exposed at the cut portion. An outer peripheral cutting step of forming a cutting peripheral surface (13) to be heat-welded to the inner peripheral surface of the pipe end (21) of the joint (20);
A chamfer cutting step of cutting the inner peripheral edge of the tip surface at the end (12) of the tube (10) to form a chamfered portion (14) having an acute cross-sectional shape;
A method for processing the end (12) of the tube (10), characterized by comprising:

[5] A tube (10) having a barrier layer (11) formed on the outer peripheral surface side is provided with a tube end (21) into which the end (12) of the tube (10) is fitted, and the tube (10) A processing device (50) for processing the end (12) of the tube (10) in order to join to a joint (20) made of a thermoplastic material,
An inner space into which the end (12) of the tube (10) is inserted is provided, and the end (12) of the tube (10) is inserted into the inner space. A rotatable jig body (51),
In the internal space of the jig body (51),
A tube guide (52) that guides to the inner space along the axial direction while holding the tube (10) by being fitted into the end (12) of the tube (10);
An axis of the tube (10) with respect to the jig main body (51), which is disposed and fixed at a position where the tube (10) is guided by the tube guide (52) to the depth of the barrier layer (11). The cutter blade for outer periphery (53) which cuts the barrier layer (11) of the tube (10) in the axial direction from the tip surface to the entire circumferential direction with the movement of the direction and the relative rotation around the axis. When,
The outer peripheral cutter blade (53) is arranged and fixed at a position where the barrier layer (11) cuts into the inner peripheral edge of the distal end surface of the tube (10) which has been cut to a predetermined length in the axial direction, and the jig body ( 51) A cutter blade for a distal end that cuts the inner peripheral edge of the distal end surface at the end portion (12) of the tube (10) over the entire circumferential direction with relative rotation around the axis of the tube (10) with respect to 51). (54)
An apparatus (50) for processing an end (12) of a tube (10), characterized in that

[6] A tube holder (60) fixed so as to surround the middle of the tube (10) with the tube (10) penetrated,
The tube holder (60) has its end surface (60a) abutting against the peripheral edge of the opening of the internal space of the jig main body (51), so that the tube (10) is connected to the tube guide (52) in the internal space. The processing device (50) for the end (12) of the tube (10) according to [5], wherein the amount of movement in the axial direction guided by the tube (10) is regulated.

The present invention operates as follows.
According to the joining structure of the tube (10) described in [1], the end portion (12) of the tube (10) has a predetermined length in the axial direction, and the barrier layer (11) on the outer peripheral surface side is cut. The cut portion has a cut surface (13) where a thermoplastic material is exposed to the outside. Here, the main part of the tube (10) excluding the barrier layer (11) is formed of the same thermoplastic material.

  In order to join the tube (10) to the joint (20), the end (12) of the tube (10) is fitted into the pipe end (21) of the joint (20) and the end of the tube (10) is joined. The cutting peripheral surface (13) in the section (12) and the inner peripheral surface in the pipe end (21) of the joint (20) made of the same thermoplastic material as the cutting peripheral surface (13) are heated from the outside. Then, they are welded and bonded together.

  Thus, in the end part (12) of the tube (10), the part directly welded to the inner peripheral surface of the pipe end part (21) of the joint (20) is the cutting circumference in which the barrier layer (11) has been removed in advance. It is a surface (13), and the site | parts which consist of a material with the mutually same thermoplasticity will be joined directly. Therefore, the tube (10) and the joint (20) can be reliably heat-welded to each other, and the bonding strength between the tube (10) and the joint (20) can be improved.

  According to the joining structure of the tube (10) described in [2], the end portion (12) of the tube (10) has the cutting circumference where the barrier layer (11) is cut and the thermoplastic material is exposed. Not only the surface (13) but also a separate auxiliary ring (40) to be externally fitted to the cutting peripheral surface (13).

  The auxiliary ring (40) is made of a thermoplastic material similar to the tube (10), and the outer peripheral surface of the auxiliary ring (40) is connected to the outer peripheral surface of the barrier layer (11) in a state where the auxiliary ring (40) is externally fitted to the cutting peripheral surface (13). Formed. That is, the auxiliary ring (40) fills the concave steps on the cutting peripheral surface (13) so as to continue to the outer periphery of the barrier layer (11) serving as a reference of the outer peripheral surface of the tube (10).

  In order to join the tube (10) to the joint (20), the end (12) of the tube (10) is fitted on the cutting peripheral surface (13) of the auxiliary ring (40) and then the joint (20). In the state fitted in the pipe end (21), the cutting peripheral surface (13) at the end (12) of the tube (10) and a joint made of a thermoplastic material similar to the cutting peripheral surface (13) ( 20) and the inner peripheral surface of the pipe end portion (21) are heated from the outside and bonded to each other via the auxiliary ring (40).

  Thus, in the end portion (12) of the tube (10), the barrier layer (11) is removed in advance from the portion that is welded directly to the inner peripheral surface of the pipe end portion (21) of the joint (20). Moreover, the concave steps are filled with the auxiliary ring (40), and the parts made of the same thermoplastic material are joined to each other through the auxiliary ring (40). Therefore, the tube (10) and the joint (20) can be reliably and firmly heat-welded without any gap, and the joint strength between the tube (10) and the joint (20) can be further improved.

  According to the joining structure of the tube (10) described in [3], the end portion (12) of the tube (10) has a chamfered portion (14) having an acute cross-sectional shape in which the inner peripheral edge of the distal end surface is cut. Have On the other hand, the tube end (21) of the joint (20) is bitten by the chamfered portion (14) in the middle of its inner peripheral surface, and the tube (10) with respect to the tube end (21) of the joint (20). The end portion (12) has a portion to be eaten (23) that regulates the position where the end portion (12) is inserted.

  Thereby, when fitting the end part (12) of the tube (10) into the pipe end part (21) of the joint (20), the engagement between the chamfered part (14) and the eroded part (23) In addition to being able to position the tube (10) at an appropriate insertion position, the chamfered portion (14) and the biting portion (23) overlap each other in the axial direction perpendicular to the axial direction. Thus, the joint strength between the tube (10) and the joint (20) can be further improved.

According to the method for processing the tube (10) end (12) described in [4], the tube (10) end (12) is processed by at least two steps.
That is, the outer peripheral surface side barrier layer (11) is cut with a predetermined length in the axial direction of the end portion (12) of the tube (10) by the outer peripheral cutting step, and a thermoplastic material is applied to the cut portion. A cutting peripheral surface (13) that is exposed and heat-welded to the inner peripheral surface (22) of the pipe end (21) of the joint (20) is formed.

Further, the inner peripheral edge of the distal end surface of the end portion (12) of the tube (10) is cut by a chamfer cutting step to form a chamfered portion (14) having an acute cross-sectional shape.
By the two processes of the outer peripheral cutting process and the chamfering cutting process, it is possible to obtain the optimum shape of the tube (10) in the above-described joint structure of the tube (10).

  According to the processing device (50) of the tube (10) end (12) described in [5] above, in order to process the end (12) of the tube (10), the inside of the jig body (51) The end (12) of the tube (10) is inserted into the space, and the end (12) of the tube (10) is fitted into the tube guide (52) in the internal space. As a result, the end (12) of the tube (10) is corrected even if it is somewhat deformed, and is guided to the collar of the internal space along the axial direction while being held by the tube guide (52).

  When the end (12) of the tube (10) is guided to the flange of the internal space, the tip end surface of the end (12) of the tube (10) comes into contact with the outer cutter blade (53). Here, when the tube (10) is further moved in the axial direction with respect to the jig main body (51) and is rotated relatively around the axis, the depth of the barrier layer (11) from the tip surface of the tube (10) is increased. The outer cutter blade (53) that bites into the edge gradually cuts the barrier layer (11) in the axial direction from the tip surface to the entire circumference.

  When the barrier layer (11) has been cut by a predetermined length in the axial direction by the outer cutter blade (53), the distal end surface of the tube (10) will now contact the distal cutter blade (54) at this position. Get in touch. In this state, when the tube (10) is rotated relative to the jig body (51) relative to the axis, the tip cutter blade (54) becomes the tip surface at the end (12) of the tube (10). The inner peripheral edge is cut along the entire circumferential direction.

  According to the processing device (50) including such a jig body (51), the cutting peripheral surface (13) obtained by excising the barrier layer (11) at the end (12) of the tube (10) and the acute angle at the tip. The chamfered portion (14) having a cross-sectional shape can be easily and continuously processed. As a result, it is possible to reduce the cost in the joint structure of the tube (10).

  According to the processing device (50) for the end (12) of the tube (10) described in [6], the tube (10) is fixed so as to surround the middle of the tube (10) in a state of passing through the tube (10). The tube holder (60) has an end surface (60a) that abuts the peripheral edge of the opening of the internal space of the jig body (51). The amount of axial movement of the tube (10) guided by the tube guide (52) is restricted.

  Thereby, the predetermined length of the cutting peripheral surface (13) at the end (12) of the tube (10), that is, the cutting peripheral surface (13), depending on the fixing position of the tube holder (60) surrounding the tube (10). The distance from the chamfered portion (14) located at the tip of the cutting surface to the base end of the cutting peripheral surface (13) can be processed to be an accurate length, and the length can be adjusted as appropriate. it can.

  According to the tube joining structure of the present invention, the barrier layer is removed in advance from the end portion of the tube having the barrier layer formed on the outer peripheral surface side, and the portion directly welded to the inner peripheral surface of the pipe end portion of the joint. By directly joining parts made of materials with the same thermoplasticity to each other, the tube can be reliably and firmly heat-welded to the joint, and the mechanical joint strength between the tube and joint Can be improved.

  In addition, not only the cutting peripheral surface where the barrier layer at the end of the tube is cut, but also a separate auxiliary ring that is externally fitted to this cutting peripheral surface, the concave step with the barrier layer removed is an auxiliary The parts made of materials having the same thermoplasticity are joined to each other through the auxiliary ring in a state of being filled with the ring, and the tube and the joint are surely and firmly heat-welded with no gap between each other. And the joint strength between the tube and the joint can be further improved.

  By using such an auxiliary ring, the welded joints currently on sale can be welded in the existing state without changing the welded part on the joint side, so there is no need to design and manufacture the joints again. Initial costs such as mold manufacturing costs can be reduced.

  Furthermore, according to the processing method and the processing apparatus for the tube end portion according to the present invention, the cutting peripheral surface obtained by cutting off the barrier layer at the end portion of the tube and the chamfered portion having an acute cross-sectional shape at the tip end are each in two steps. It becomes possible to process continuously and easily. As a result, it is possible to reduce the cost in the tube connection structure.

Hereinafter, various embodiments representing the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing a state of the tube 10 according to the first embodiment of the present invention when the tube 10 is welded to the joint 20 by heat welding. FIG. 2 is a perspective view showing a partially broken state when the tube 10 is fitted into the joint 20 with respect to the joint structure of the tube 10 according to the first embodiment.

  As shown in FIGS. 1 and 2, the tube 10 is a hollow cylindrical tube, and specific materials thereof include, for example, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoro A fluororesin represented by ethylene (PTFE) or the like is used. That is, the material of the tube 10 is not only excellent in chemical resistance but also a thermoplastic material that can be melt processed. Note that the material of the tube 10 refers to the material of the main part other than the barrier layer 11.

  On the outer peripheral surface side of the tube 10, a barrier layer 11 made of a material having a lower permeability than the above-described material is formed. The barrier layer 11 is made of, for example, a barrier fluoropolymer (CPT) obtained by adding an additive to PFA, and has a function of improving the barrier property of the tube 10 against a highly permeable acid. For example, the thickness of the barrier layer 11 is preferably about one third of the entire thickness of the joint 20.

  Such a tube 10 has a cutting peripheral surface 13 in which the barrier layer 11 on the outer peripheral surface side is cut at a predetermined length in the axial direction from the front end surface at the end portion 12, and a thermoplastic material is exposed at the cut portion. have. This cutting peripheral surface 13 becomes a part which is heat-welded to the inner peripheral surface 22 in the pipe end portion 21 of the joint 20 described below.

  Further, the tube 10 has a chamfered portion 14 having an acute cross-sectional shape in which the inner peripheral edge of the distal end surface at the end portion 12 is cut and inclined in a tapered shape toward the outer peripheral side and the opening end from the axis of the end portion 12. is doing. The chamfered portion 14 is a portion that bites into the biting portion 23 on the inner peripheral surface 22 of the pipe end portion 21 in the joint 20 described below.

  As shown in FIGS. 1 and 2, the joint 20 is basically a hollow cylindrical tube as in the case of the tube 10. The specific material is, for example, tetrafluoroethylene / perfluoroalkyl. A fluororesin represented by vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE) or the like is used. In the present embodiment, the tube 10 and the joint 20 are each formed from the same material.

  The joint 20 includes a pipe end portion 21 into which the end portion 12 of the tube 10 is fitted on one end side thereof. The inner peripheral surface 22 of the joint 20 includes a guide surface 22a for guiding the end portion 12 of the tube 10 in order from the distal end of the tube end portion 21, an outward surface 22b for forming an encroached portion 23 described later, and an inner surface. It is divided into a circumferential reference surface 22c.

  The guide surface 22 a has a larger inner diameter than the inner peripheral reference surface 22 c that forms the reference surface of the inner peripheral surface 22. Specifically, the inner diameter of the guide surface 22 a is set to be slightly larger than the outer diameter of the cutting peripheral surface 13 of the tube 10 except for the portion near the opening end of the tube end portion 21. When the end portion 12 (more precisely, the cutting peripheral surface 13) of the tube 10 is inserted, the cutting peripheral surface 13 is brought into contact with each other.

  The outward surface 22b is inclined in a tapered shape from the end of the guide surface 22a toward the axial center of the tube end portion 21 and the open end. Accordingly, the outward surface 22b and the guide surface 22a intersect each other at an acute angle, and the encroached portion 23 is formed at the site. The biting portion 23 is for restricting the position where the end portion 12 of the tube 10 is inserted into the pipe end portion 21 of the joint 20 by the chamfering portion 14 at the end portion 12 of the tube 10 biting in. It is a part.

  The inner peripheral reference surface 22 c is formed with a uniform inner diameter from the encroached portion 23 to the other end side of the joint 20. The inner peripheral reference surface 22c is set to have the same inner diameter as the inner peripheral surface of the tube 10 joined to the joint 20, and is set to be continuous as an inner peripheral surface having the same inner diameter.

  A tubular outer ring 30 is attached to the pipe end portion 21 of the joint 20 so as to surround the outer peripheral surface thereof. The outer peripheral surface of the outer ring 30 is in contact with the outer peripheral surface of the pipe end 21 of the joint 20, and further overlaps the position where the pipe end 21 of the joint 20 and the cutting peripheral surface 13 of the tube 10 overlap in the axial direction. To be fitted.

  The outer ring 30 is formed of a material in which the molten joint 20 and the tube 10 are difficult to weld. Examples of such a material include PTFE and modified PTFE. A heat transfer member for transferring heat from a heating device (not shown) is disposed on the outer peripheral surface side of the outer ring 30.

  Next, the processing device 50 for the end 12 of the tube 10 shown in FIGS. 3 to 5 will be described. The processing apparatus 50 includes a jig body 51 and a tube holder 60 that is an accessory thereof. The tube holder 60 is not an essential component of the processing apparatus 50 and can be omitted.

  The jig body 51 is formed in a substantially cylindrical shape so as to be easily gripped, and includes an internal space into which the end portion 12 of the tube 10 is inserted. With the end 12 of the tube 10 inserted into this internal space, the jig body 51 is operated by being relatively rotated about the axis of the tube 10.

  In the inner space of the jig body 51, a tube guide 52 is fixed to a bottom surface portion opposite to the opening. The tube guide 52 is a member for guiding the end portion 12 of the tube 10 to guide the inner space along the axial direction while holding the tube 10.

  The tube guide 52 is formed in a truncated cone shape that tapers from the proximal end in contact with the bottom of the internal space toward the distal end so that the end 12 of the tube 10 can be easily fitted. The outer diameter of the base end of the tube guide 52 is set to be slightly smaller than the inner diameter of the end portion 12 of the tube 10, and the end of the tube 10 is interposed between the outer peripheral wall of the tube guide 52 and the inner peripheral wall of the internal space. A gap for guiding the portion 12 is formed.

  Further, an outer cutter blade 53 for cutting the barrier layer 11 of the tube 10 to form the cutting peripheral surface 13 is disposed in the internal space of the jig main body 51. The outer cutter blade 53 is fixed to the mounting concave groove 51a opened from the outer peripheral surface of the jig main body 51 to the side of the inner space with a screw 53b so that the blade edge faces the inner space.

  The cutter blade 53 for outer periphery is disposed and fixed at a position where it penetrates from the distal end surface of the tube 10 guided by the tube guide 52 to the depth of the barrier layer 11, and the axial movement and axial center of the tube 10 with respect to the jig body 51. With the relative rotation around, the barrier layer 11 of the tube 10 is cut in the axial direction over the entire circumference from the tip surface.

  The outer cutter blade 53 is arranged and fixed with respect to the circumferential tangent of the tube 10 so as to have a contact angle at which the barrier layer 11 can be cut. According to the results of experiments by the inventors, the outer cutter blade 53 is shown in FIG. Specifically, it has been confirmed that optimum cutting performance can be obtained when the contact angle is specifically set to 146 degrees. Therefore, the contact angle is preferably set within a predetermined range centered at 146 degrees.

  Further, the fixing position of the outer cutter blade 53 is adjusted as appropriate by the relative movement of the screw 53b with respect to the long groove-like screw hole 53a in the outer cutter blade 53. Can do. The mounting concave groove 51a also serves as a space for releasing cutting waste from the barrier layer 11 of the tube 10.

  Further, in the internal space of the jig body 51, a tip cutter blade 54 for cutting the inner peripheral edge of the tip end surface of the tube 10 to form the chamfered portion 14 is disposed. The tip cutter blade 54 is fixed to a mounting groove 51b formed from the bottom surface of the jig main body 51 toward the internal space with a screw 54b with the blade edge facing the internal space.

  The tip cutter blade 54 is disposed and fixed at a position where the outer peripheral cutter blade 53 bites into the inner peripheral edge of the distal end surface of the tube 10 after the barrier layer 11 has been cut to a predetermined length in the axial direction. With the relative rotation around the axis of the tube 10, the inner peripheral edge of the distal end surface of the tube 10 is cut over the entire circumferential direction.

  The fixing position of the tip cutter blade 54 can also be adjusted as appropriate by the relative movement of the screw 54b with respect to the long groove-like screw hole 54a. The mounting concave groove 51b also serves as a space for releasing chamfered cutting waste at the tip of the tube 10.

  As shown in FIG. 5, the tube holder 60 that constitutes the processing apparatus 50 together with the jig main body 51 is fixed so as to surround the middle of the tube 10 in a state where the tube 10 is penetrated. The tube holder 60 includes a pair of clamps 61 and 62, and the clamps 61 and 62 are connected so that one end thereof can be opened and closed by a hinge.

  Each of the clamps 61 and 62 has a semicircular cross-sectional groove formed in a portion facing each other. When one clamp 61 is fixed to the other clamp 62 by a fastening screw 63, The circular cross-sectional groove forms one circular hole and is configured so as to sandwich the middle of the tube 10 from above and below. Such a tube holder 60 has an end face 60a abutting against the peripheral edge of the opening of the internal space of the jig body 51 so that the tube 10 is guided by the tube guide 52 in the internal space in the axial direction. Is to regulate.

Next, a method of processing the end portion 12 of the tube 10 by the processing apparatus 50 according to the present embodiment will be described with reference to FIGS.
The tube 10 is previously held in a state of being positioned by the tube holder 60. That is, as shown in FIG. 6, the clamps 61 and 62 of the tube holder 60 hold the tube 10 so that the middle of the tube 10 is sandwiched from above and below, so that the end portion 12 of the tube 10 is a predetermined length. It is held in a state protruding from the end face 60a.

  In FIG. 7, the jig main body 51 is pressed against the end 12 of the tube 10 from the opening side of the internal space so that the end 12 of the tube 10 is inserted into the internal space of the jig main body 51. At this time, the end 12 of the tube 10 is guided into the gap between the outer peripheral wall of the tube guide 52 and the inner peripheral wall of the internal space while being fitted into the tube guide 52 in the internal space. As a result, the end 12 of the tube 10 is corrected even if it is slightly deformed, and is guided by the inner space along the axial direction while being held by the tube guide 52.

  Subsequently, when the tube guide 52 is inserted into the end portion 12 of the tube 10, the corner of the outer cutter blade 53 comes into contact with the depth position of the barrier layer 11 from the distal end surface of the tube 10. Here, when the jig main body 51 is further moved in the axial direction with respect to the tube 10 and is relatively rotated around the axis, as shown in FIG. The outer cutter blade 53 that cuts into the depth of 11 can gradually cut the barrier layer 11 in the axial direction from the tip surface to the entire circumference.

  By such an outer periphery cutting process, the barrier layer 11 on the outer peripheral surface side is cut with a predetermined length in the axial direction of the end portion 12 of the tube 10, and the thermoplastic material is exposed at the cut portion. Thereby, the cutting peripheral surface 13 which heat-welds to the internal peripheral surface in the pipe end part 21 of the coupling 20 is formed in the end part 12 of the tube 10 (refer FIG. 4).

  In FIG. 8, when the barrier layer 11 has been cut by a predetermined length in the axial direction by the outer cutter blade 53, the distal end surface of the tube 10 is in contact with the distal cutter blade 54 at this position and bites. . In this state, when the tube 10 is rotated relative to the jig body 51 around the axis, the tip cutter blade 54 extends over the entire peripheral direction of the inner peripheral edge of the tip surface of the end portion 12 of the tube 10. To cut.

  By such a chamfer cutting step, the inner peripheral edge of the distal end surface of the end portion 12 of the tube 10 can be cut to form the chamfered portion 14 having an acute cross-sectional shape. At this time, the tube holder 60 has its end surface 60a abutting against the peripheral edge of the opening of the internal space of the jig main body 51, so that the amount of movement in the axial direction in which the tube 10 is guided by the tube guide 52 in the internal space is increased. Be regulated.

  As a result, a predetermined length of the cutting peripheral surface 13 at the end 12 of the tube 10, that is, from the chamfered portion 14 positioned at the tip of the cutting peripheral surface 13 according to the fixing position of the tube holder 60 surrounding the tube 10. The distance to the base end of the surface 13 can be processed to be an accurate length, and the length can be adjusted as appropriate. When the processing is finished, the jig body 51 may be pulled away from the end 12 of the tube 10 as shown in FIG.

  By using the processing apparatus 50 as described above, the cutting peripheral surface 13 obtained by cutting the barrier layer 11 at the end 12 of the tube 10 and the chamfered portion 14 having an acute cross-sectional shape at the tip are continuously and substantially simultaneously. It can be easily processed. As a result, the optimum shape of the end portion 12 in the joining structure of the tube 10 can be easily obtained, and the cost in the joining structure of the tube 10 can be reduced.

Next, the operation of the joining method of the tube 10 and the joint 20 or the joining structure of the tube 10 will be described.
In order to join the tube 10 having the end 12 processed as described above to the joint 20, first, the end 12 of the tube 10 is fitted into the pipe end 21 of the joint 20. At this time, the chamfered portion 14 of the end portion 12 is inserted until it hits the biting portion 23 at the end of the guide surface 22 a formed in the pipe end portion 21 of the joint 20.

  Then, as shown in FIG. 1, the cutting peripheral surface 13 at the end portion 12 of the tube 10 and the guide surface 22a at the tube end portion 21 of the joint 20 made of the same thermoplastic material are opposed to each other. Here, the tube 10 can be positioned at an appropriate insertion position with respect to the joint 20 by the engagement between the chamfered portion 14 and the biting portion 23.

  In this state, heat from a heating device (not shown) is conducted to the tube end 21 of the joint 20 and the end 12 of the tube 10 through the outer ring 30. Thereby, the pipe end 21 of the heated joint 20 and the end 12 of the tube 10 are melted when reaching the melting temperature. Thereby, the cutting peripheral surface 13 and the guide surface 22a are heat-welded mutually and integrally joined.

  As described above, in the end portion 12 of the tube 10, the portion directly welded to the inner peripheral surface 22 of the pipe end portion 21 of the joint 20 has the barrier layer 11 removed in advance, and is made of a material having the same thermoplasticity. Will be joined directly. Therefore, the tube 10 and the joint 20 can be reliably heat-welded to each other and the joint strength between the tube 10 and the joint 20 can be improved.

  In particular, the chamfered portion 14 and the encroached portion 23 overlap each other in the axial direction intersecting at right angles to the axial direction, and the joint strength between the tube 10 and the joint 20 can be further improved. Note that the chamfered portion 14 and the encroached portion 23 may be omitted.

11 and 12 show a second embodiment of the present invention.
The joining structure of the tube 10 according to the present embodiment has a separate auxiliary ring 40 that is fitted on a cutting peripheral surface 13 formed by cutting the barrier layer 11 at the end 12 of the tube 10. The auxiliary ring 40 is formed of the same thermoplastic material as that of the tube 10 so that the outer peripheral surface is connected to the outer peripheral surface of the barrier layer 11 in a state where the auxiliary ring 40 is externally fitted to the cutting peripheral surface 13.

  That is, the auxiliary ring 40 plays a role of filling a concave step in the cutting peripheral surface 13 so as to continue to the outer periphery of the barrier layer 11 serving as a reference of the outer peripheral surface of the tube 10. The auxiliary ring 40 may be provided with a tapered portion chamfered on the inner peripheral edge of the opening end so as to be easily fitted to the cutting peripheral surface 13 of the tube 10.

  In this embodiment, in order to join the tube 10 to the joint 20, as shown in FIG. 12, the end portion 12 of the tube 10 is externally fitted to the cutting peripheral surface 13, and then the joint 20 is joined. In a state of being fitted into the tube end portion 21, a cutting peripheral surface 13 at the end portion 12 of the tube 10, and an inner peripheral surface 22 at the tube end portion 21 of the joint 20 made of the same thermoplastic material as the cutting peripheral surface 13 Are heated and welded to each other through the auxiliary ring 40 and joined together.

  As described above, in the end portion 12 of the tube 10, the barrier layer 11 is previously removed from the portion of the pipe end portion 21 of the joint 20 that is directly welded to the inner peripheral surface 22, and the concave step is formed by the auxiliary ring 40. In a state where the holes are filled, the parts made of materials having the same thermoplasticity are joined to each other through the auxiliary ring 40. Therefore, the tube 10 and the joint 20 can be heated and welded reliably and firmly without any gap, and the joint strength between the tube 10 and the joint 20 can be further improved.

  In addition, by using the auxiliary ring 40, the welded joints currently sold can be welded without changing the joint-side welded part, so that it is not necessary to redesign and manufacture the joints. Initial costs such as mold manufacturing costs can be reduced.

  Note that parts that are the same as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted. Moreover, about the processing apparatus 50 of the edge part 12 of the tube 10 which is common in 1st Embodiment, the method of processing the edge part 12 of the tube 10 with the processing apparatus 50, and the concrete joining method of the tube 10 and the coupling 20 The detailed description of is also omitted.

  The embodiments of the present invention have been described above with reference to the drawings. However, the specific configuration is not limited to the above-described embodiments, and changes and additions may be made without departing from the scope of the present invention. It is included in the present invention. For example, in the first and second embodiments, the example in which the chamfered portion 14 is formed on the end portion 12 of the tube 10 has been described. However, the chamfered portion 14 may be omitted.

  In addition, a gap is provided in advance between the tapered surface of the chamfered portion 14 at the end 12 of the tube 10 and the tapered surface of the encroached portion 23 at the inner peripheral surface 22 of the joint 20, and heat welding is performed. The gap may be eliminated while expanding the contact surfaces with each other by expansion at the time, and air may be pushed out and escaped. Thereby, it is possible to join by heating and welding without generating a void in the welded portion and without generating a bead bulge or a dent inside the welded portion.

  Furthermore, the tube 10 and the joint 20 are used, for example, as a flow conduit for cleaning liquid such as pure water used in a clean room at a semiconductor chip manufacturing site or the like, and other general chemical liquids, but the material is not necessarily synthetic resin. It is not limited, and it is also possible to use a metal material that can be thermally welded. Of course, the tube 10 and the joint 20 are not necessarily limited to the same material as long as they are thermoplastic materials that can be welded together.

It is a longitudinal cross-sectional view which shows the state at the time of heat-welding and joining a tube to a joint regarding the joining structure of the tube which concerns on 1st Embodiment of this invention. It is a perspective view which shows the state at the time of joining partially by heating-welding a tube to a joint and shows a part about the joining structure of the tube concerning a 1st embodiment of the present invention. It is a disassembled perspective view which shows the processing apparatus of the tube edge part which concerns on 1st Embodiment of this invention. It is a longitudinal cross-sectional view for demonstrating the effect | action of the processing apparatus of the tube edge part which concerns on 1st Embodiment of this invention. It is a longitudinal cross-sectional view which expands partially in order to demonstrate the effect | action of the processing apparatus of the tube edge part which concerns on 1st Embodiment of this invention. It is a perspective view for demonstrating in order the effect | action of the processing apparatus of the tube edge part which concerns on 1st Embodiment of this invention. It is a perspective view for demonstrating in order the effect | action of the processing apparatus of the tube edge part which concerns on 1st Embodiment of this invention. It is a perspective view for demonstrating in order the effect | action of the processing apparatus of the tube edge part which concerns on 1st Embodiment of this invention. It is a perspective view for demonstrating in order the effect | action of the processing apparatus of the tube edge part which concerns on 1st Embodiment of this invention. It is a cross-sectional view which shows the processing apparatus of the tube edge part which concerns on 1st Embodiment of this invention. It is a longitudinal cross-sectional view which shows the state at the time of heat-welding and joining a tube to a joint regarding the joining structure of the tube which concerns on 2nd Embodiment of this invention. It is a perspective view which shows the state at the time of joining partially by heating-welding a tube to a joint regarding the joining structure of the tube which concerns on 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Tube 11 ... Barrier layer 12 ... End part 13 ... Cutting peripheral surface 14 ... Chamfering part 20 ... Joint 21 ... Pipe end part 22 ... Inner peripheral surface 22a ... Guide surface 22b ... Outward surface 22c ... Inner peripheral reference surface 23 ... Encroached part 30 ... Outer ring 40 ... Auxiliary ring 50 ... Processing device 51 ... Jig main body 51a ... Mounting groove 51b ... Mounting groove 52 ... Tube guide 53 ... Cutter blade for outer periphery 53a ... Screw hole 53b ... Screw 54 Cutter blade for tip 54a ... Screw hole 54b ... Screw 60 ... Tube holder 60a ... End face 61, 62 ... Clamp 63 ... Fastening screw

Claims (6)

In the tube joining structure for joining the tube with the barrier layer formed on the outer peripheral surface side and the joint having the tube end portion into which the end portion of the tube is fitted, respectively.
The end portion of the tube has a cutting peripheral surface where the barrier layer on the outer peripheral surface side is cut at a predetermined length in the axial direction, and a thermoplastic material is exposed at the cut portion.
With the end of the tube fitted into the pipe end of the joint, the cutting peripheral surface at the end of the tube and the inner peripheral surface at the pipe end of the joint made of the same thermoplastic material. A tube joining structure characterized in that they are joined by heating and welding to each other. In the tube joining structure for joining the tube with the barrier layer formed on the outer peripheral surface side and the joint having the tube end portion into which the end portion of the tube is fitted, respectively.
The end portion of the tube has a predetermined length in the axial direction, the cutting of the barrier layer on the outer peripheral surface side, and a cutting peripheral surface where a thermoplastic material is exposed at the cut portion, and an outer periphery of the cutting peripheral surface. A separate auxiliary ring to be fitted,
The auxiliary ring is made of a thermoplastic material similar to the tube, and is formed in a thickness where the outer peripheral surface is continuous with the outer peripheral surface of the barrier layer, with the outer peripheral surface being fitted to the cutting peripheral surface.
In the state where the end of the tube is fitted into the pipe end of the joint with the auxiliary ring fitted, the cutting peripheral surface of the end of the tube and the joint made of the same thermoplastic material A tube joining structure characterized in that an inner peripheral surface at a pipe end portion is joined by heating and welding to each other via the auxiliary ring. The end portion of the tube has a chamfered portion with an acute cross-sectional shape in which the inner peripheral edge of the distal end surface is cut.
The pipe end portion of the joint has a bite portion that regulates a position where the end portion of the tube is fitted to the pipe end portion of the joint by the chamfered portion biting in the middle of the inner peripheral surface thereof. The tube joining structure according to claim 1 or 2, characterized in that In order to join a tube having a barrier layer formed on the outer peripheral surface side thereof to a joint made of a thermoplastic material like the tube, the tube end portion is fitted with the tube end portion. A method of processing,
The barrier layer on the outer peripheral surface side is cut at a predetermined length in the axial direction of the end portion of the tube, and a thermoplastic material is exposed at the cut portion, so that the inner peripheral surface at the pipe end portion of the joint An outer periphery cutting step for forming a cutting peripheral surface to be heat-welded to,
A chamfer cutting step of cutting the inner peripheral edge of the tip surface at the end of the tube to form a chamfered portion having an acute cross-sectional shape,
The processing method of the tube edge part characterized by having. In order to join a tube having a barrier layer formed on the outer peripheral surface side thereof to a joint made of a thermoplastic material like the tube, the tube end portion is fitted with the tube end portion. A processing device for processing,
It has an internal space for inserting the end of the tube, and has a jig body that is relatively rotatable around the axis of the tube with the end of the tube inserted in the internal space.
In the internal space of the jig body,
A tube guide that guides the inner space along the axial direction while holding the tube by being fitted into the end of the tube;
In accordance with the axial movement of the tube relative to the jig body and the relative rotation around the axis centered at a position that penetrates from the distal end surface of the tube guided by the tube guide to the depth of the barrier layer. , An outer cutter blade that cuts the barrier layer of the tube in the axial direction over the entire circumference from the tip surface;
The barrier layer is disposed and fixed at a position where the barrier layer bites into the inner peripheral edge of the distal end surface of the tube that has been cut to a predetermined length in the axial direction by the outer cutter blade, and is relative to the jig main body around the axis of the tube. With the rotation, the cutter blade for the tip that cuts the inner peripheral edge of the tip surface at the end of the tube over the entire circumferential direction,
An apparatus for processing a tube end portion. A tube holder fixed so as to surround the middle of the tube in a state where the tube is penetrated,
The tube holder has its end face abutting against the peripheral edge of the opening of the internal space of the jig body, thereby restricting the amount of axial movement of the tube guided by the tube guide in the internal space. The tube end portion processing apparatus according to claim 5, wherein the tube end portion processing apparatus is characterized in that:

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