JP2001012676A - Fusion connecting structure of resin pipe and fusion connecting method of resin pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an accident such as breakage from being caused in a resin pipe and to visually determine the quality of the connecting state by restraining the relative bending deformation of a resin pipe or resin cylinder at the end of a fusion-connecting position when a bending force is applied to the fusion-connected resin pipe or resin cylinder to the degree that it is not broken. SOLUTION: This connecting method comprises fitting a resin cylinder 2 to a resin pipe 1 and fusion connecting the both in an overlapping part (b). A cylindrical sheath part 24 protruded from a fusion connecting position (overlapping part b) and fitted onto the resin pipe 1 is extended from the resin cylinder 2. The sheath part 24 regulates the bending deformation of the resin pipe 1 at the end of the fusion connecting position to the degree that it is not broken. The resin cylinder 2 has an inspection port 25 facing the end of the fusion connecting position, and the excessive resin generated in the fusion connection of the overlapping part (b) is penetrated into the inspection port 25 to form a swollen part 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin tube fusion joining structure and a resin tube fusion joining method.

[0002]

2. Description of the Related Art Conventionally, a resin pipe made of a thermoplastic resin such as a polybutene pipe is attached to another resin pipe made of a thermoplastic resin compatible with the constituent resin of the resin pipe or a resin tubular body such as a resin joint. The following procedure has been adopted when fitting and fusing together.

That is, by using a predetermined heater,
The resin inner layer of the resin tube and the resin outer layer of the resin tube are heated and melted so that they can be joined, and then removed from the heater for heating. Then, the fused resin outer layer portion and the resin inner layer portion are fused by fusing, and thereafter, the fused portion is cured. When this procedure is adopted, excess resin generated when the resin cylinder is externally fitted into the resin pipe in a press-fitting manner protrudes into the inner portion of the resin cylinder and the end of the resin cylinder, and is called a bead. Form extra slugs.

When a resin joint and a resin pipe are joined in an appropriate state, a bead (hereinafter, referred to as a “resin bead”) is formed in a ring shape. Therefore, the shape of the resin bead is used to determine the quality of the bonding state, and when the resin bead is formed in a ring-shaped shape, the bonding state is determined to be good, and the resin bead is determined to have a discontinuous portion or insufficient swelling. When this occurred, it was determined that the connection was defective (first conventional example).

There is also a fusion bonding structure and a fusion bonding method for a resin pipe using the tool 5 shown in FIGS. 4 to 7 (second conventional example). FIGS. 7 to 9 show the joining method.

In FIG. 9, reference numeral 1 denotes a resin tube, and 2 denotes a resin cylinder formed by a connection port of a resin joint. 2
Are fusion-bonded at an overlapping portion A shown by a broken line. Further, a corner-shaped recess 4 formed by the end surface 21 of the resin cylinder 2 and the outer surface 11 of the resin tube 1 is filled with the resin bead 3.

[0007] Such a fusion bonding structure is formed by a method described below. In this method, the tool 5 shown in FIG. 4 is used. The tool 5 fixes a pair of upper and lower openable / closable clamp pieces 51 for holding the resin tube 1, a measuring slide piece 53 attached to the upper clamp piece 51, and the slide piece 53 to the clamp piece 51. And a tightening tool 54 for the purpose. The front ends of the pair of clamp pieces 51 and slide pieces 53 are provided with outwardly extending inclined surfaces 51a and 53a. And FIG.
5 and FIG. 5, the slide piece 53 is retracted and its tip 56 is moved to the pair of clamp pieces 5.
When the end portions 55 are flush with each other, the inclined surfaces 51a and 53a of the clamp piece 51 and the slide piece 53 cooperate with each other to form a tapered expanding surface 57.

In the tool 5, the allowance (fitting length) L of the resin tube 1 with respect to the resin cylinder 2 and the length a (see FIG. 7) of a heating zone by a heater for heating (described later) are appropriately determined. Used for In order to properly determine the insertion allowance L,
As shown in FIG. 6, the slide piece 53 is protruded from the clamp piece 51 by a desired length L so that its tip 56 matches the tip position of the resin tube 1 loosely held by the pair of clamp pieces 51. After the resin tube 1 is strongly clamped by the pair of clamp pieces 51, the slide piece 53 may be retracted to the position shown in FIG. 4 or FIG.
The end of the resin tube 1 protrudes from the pair of clamp pieces 51 holding the same by the above-mentioned length L, and the length L is an insertion margin.

As shown in FIG. 7, a heating heater 6 is set in the resin pipe 1 in which the insertion margin L is appropriately determined. At this time, the length a of the heating area is determined by the clamp piece 51 holding the resin tube 1. That is, as shown in the figure, the heating heater 6 has a tubular resin tube side heating section 62 fitted into the resin tube 1, and the heat of the resin tube side heating section 62 causes the resin tube side heating section 62 to heat the resin tube side. The resin outer layer portion 12 of the resin pipe 1 with which the portion 62 is in contact or close proximity is heated and melted. Further, as shown in the figure, the resin tube side heating unit 62 is fitted into the resin tube 1 until the tip of the heating unit 62 hits the clamp piece 51. for that reason,
The length a of the heating zone by the heater 6 and the insertion margin L are substantially the same. On the other hand, the heater 6 is also used to heat the resin cylinder 2. That is, the heater 6 for heating is provided with the cylindrical-body-side heating unit 63,
The resin inner layer portion 22 of the resin cylinder 2 with which the cylinder-side heating portion 63 is in contact or close proximity is heated and melted. At this time, the heating area length b of the resin cylinder 2 by the cylinder-side heating section 63 is set substantially equal to the heating area length a of the resin pipe 1 described above.

After the heating and melting of the resin inner layer 22 of the resin tube 2 and the heating and melting of the resin outer layer 12 of the resin tube 1 are simultaneously performed, the resin tube 2 from which the heater 6 is removed is removed. It is externally fitted into the resin tube 1 in a press-fitting manner. At this time, as shown in FIG. 8, the resin tube 2 is inserted until it comes into contact with the tip 55 of the clamp piece 51 and the tip 56 of the slide piece 53.
The resin tube 2 and the resin inner layer portion 22 of the resin tube 2 that are heated and melted are fused to each other at an overlapping portion A of the resin tube 1 and the resin tube 2. In addition, as the resin cylinder 2 is externally fitted into the resin pipe 1 in a press-fitting manner, excess resin protruding from the end of the resin cylinder 2 fills the above-described corner-shaped recess 4 to form a resin bead. 3
To form In this case, since the recessed portion 4 in the corner shape is closed by the tapered surface 57 formed by the clamp piece 51 and the slide piece 53 of the tool 5, the resin bead 3 filling the recess 4 is formed. The outer surface 31 of the resin tube 1 is separated from the outer surface 1 of the resin tube 1 by a tapered surface 57 that expands.
It is formed into a shape inclined downwardly toward 1. In FIG. 9, reference symbol B indicates an overlapping portion between the end face 21 of the resin cylinder 2 and the resin bead 3, and reference symbol C indicates an overlapping portion between the outer surface 11 of the resin pipe 1 and the resin bead 3. 8 and 9, the dashed line indicates the fusion-bonded portion, and the solid line indicates the fusion-bonded portion.

Further, after the resin cylinder and the resin pipe are fitted in a press-fitting manner and their overlapping portions are fusion-bonded, the resin cylinder and the resin pipe are elastically held by using a rubber reinforcing member. (3rd conventional example).

[0012]

In the above-mentioned first conventional example, even if it is determined from the shape of the resin bead that the joining state is good, when a bending force is applied to the resin tube, the resin tube is closed. In some cases, stress was extremely concentrated on the resin tube at the end, and the resin tube was broken at that portion in some cases.

In the above-mentioned second conventional example, as shown in FIG. 9, the outer surface 31 of the resin bead 3 is formed so as to be inclined downward from the resin cylinder 2 toward the outer surface 11 of the resin tube 1. Therefore, when a bending force is applied to the resin pipe 1, the force is dispersed within the length range of the overlapping portion c. Therefore, at the end of the resin cylinder 2, the resin pipe 1
Extremely concentrated stress is avoided. Therefore, compared to the case of the first conventional example, there is less possibility that the resin pipe 1 is broken due to the concentration of the bending stress. However, since the resin bead 3 is formed of the above-described small amount of surplus resin and its length is very short, the resin bead 3 is formed at the end of the resin cylindrical body 2, that is, at the end of the fusion bonding portion (overlapping portion a). The effect of restricting the bending deformation of the member of the resin tube 1 and preventing its breakage was hardly exhibited, and was not a sufficient measure for preventing breakage.

In the above third conventional example, a rubber reinforcing member is fitted into a resin pipe before joining, and after the temperature of the fusion joint is lowered to room temperature, a resin bead is formed. It is necessary to pull back the reinforcing tool so as to cover the resin tube and elastically press it over the resin cylinder and the resin tube. Therefore, there is a problem that the operation is troublesome, and labor and cost are required.

The present invention has been made in view of the above circumstances and problems, and when a bending force is applied to a resin pipe or a resin cylindrical body that is fusion-bonded to each other, an end of the fusion-bonded portion is formed. A resin pipe fusion bonding structure that can suppress the relative bending deformation of the resin pipe and the resin cylinder to such an extent that the resin pipe does not break, thereby avoiding the occurrence of breakage or the like in the resin pipe. The purpose is to provide.

Another object of the present invention is to provide a method for fusing and joining resin pipes capable of forming such a fusion-bonded structure.

Still another object of the present invention is to provide a fusion bonding structure and a fusion bonding method which can visually determine the quality of a bonding state.

[0018]

SUMMARY OF THE INVENTION In a fusion splicing structure for a resin tube according to the present invention, one member (resin cylinder 2) of a resin tube 1 and a resin cylinder 2 which is a counterpart thereof is connected to the other side. They are externally fitted to the member (resin tube 1), and they are fused and joined at the overlapping portion d. Further, a cylindrical sheath portion 24 that protrudes from the fusion bonding portion and is externally fitted to the other member extends from the one side member, and the sheath portion is an end portion of the fusion bonding portion. Thus, the bending deformation of the other side member is restricted within a range not to break.

As described above, the cylindrical sheath extending from the one-side member protrudes from the fusion-bonded portion and is externally fitted to the other-side member, and does not break the bending deformation of the other-side member. If the bending stress is extremely restricted to the other side member at the end of the fusion-bonded portion, the bending deformation of the other side member is prevented by the sheath portion. As a result, the other side member is prevented from being broken. In order to restrict the bending deformation of the other side member by the sheath portion within a range that does not break, the length of the sheath portion is made sufficiently long so that the bending stress applied to the one side member falls within the length range of the sheath portion. It is effective to be distributed.

An inspection port 25 is formed in the one-side member so as to allow the excess resin, which faces the end of the fusion-bonding portion and is generated at the time of fusion-bonding of the overlapped portion, to enter the excess portion 32. It is desirable to have been. With this configuration, it is possible to visually check through the inspection port whether the surplus resin has entered the inspection port to form an extra bulge. Therefore, it is possible to determine the quality of the joined state by visually checking the extra height portion from the inspection opening.

According to the method for fusion-bonding a resin pipe according to the present invention, one side member of a resin pipe and a counterpart resin cylindrical body is externally fitted to the other side member and both are fused at an overlapping portion. It relates to a joining method.

Further, in the method for fusion joining resin tubes according to the present invention, one side member is divided into a sheath portion 24 on the distal end side and an outer joint portion 26 adjacent to the sheath portion. The resin inner layer portion 22 is heated and melted, and the other side member is divided into an inner joint portion 16 overlapped with the outer joint portion and a fitting portion 17 overlapped with the sheath portion adjacent to the inner joint portion. In a state where the resin outer layer portion 12 of the inner joint portion is heated and melted, the two members are fitted into each other in a press-fitting manner, so that the resin inner layer portion of the melted outer joint portion of the one side member and the other side member And fusing the molten outer joint portion of the inner joint portion with the resin outer layer portion, and externally fitting the sheath portion of the one-side member to the fitting portion of the other-side member. And the above-mentioned inner joint portion are cured.

According to this method, the resin inner layer portion of the one side member and the resin outer layer portion of the other side member are fusion-bonded, and the sheath portion of the one side member is externally fitted to the fitting portion of the other side member. The fused joint structure, that is, the fused joint structure according to the present invention described above is formed.

When the method of the present invention is carried out, the boundary between the sheath portion of the one-side member and the outer joint portion is provided at the boundary between the resin inner layer portion of the outer joint portion where the one-side member is melted and the melting portion of the other member. It is desirable that an inspection port is provided for allowing excess resin generated when fitting the inner joint portion to the resin outer layer portion to enter to form a surplus portion. According to this method, if the surplus portion is visually observed through the inspection port, it can be determined that the joining has been successfully performed when the surplus resin enters the inspection port to form the surplus portion. If is not formed or is formed only insufficiently, it is possible to determine that the bonding is defective. In the description of this column, reference numerals in the drawings are used to facilitate understanding of the contents, and are not intended to limit the contents of the invention to those shown in the drawings.

[0025]

1 and 2 show an embodiment of a fusion bonding method according to the present invention. FIG. 3 shows an embodiment of the fusion bonding structure obtained by the method.

In FIG. 3 showing the fusion bonding structure, 1 indicates a resin tube, and 2 indicates a resin cylinder. The resin cylindrical body 2 is formed by a connection port of a resin joint, and a protrusion 23 is provided in a ring shape inside a central portion in the axial direction. Further, the distal end portion 13 of the resin pipe 1 is fusion-bonded to the projection 23 of the resin tubular body 2 which is externally fitted to the resin pipe 1 so as to form an extra portion 13a. A predetermined length portion on the side and an overlapping portion d of the resin cylinder 2 are fusion-bonded. On the other hand, a sufficiently long cylindrical sheath portion 24 protruding from the overlapping portion d which is a fusion bonding portion extends from the resin tubular body 2, and the sheath portion 24 is externally fitted to the resin pipe 1. Then, the bending deformation of the resin tube 1 at the end of the overlapping portion d is restricted within a range not to break.
Further, inspection ports 25 are opened at a plurality of locations (for example, four locations) in the circumferential direction of the root portion of the sheath portion 24 of the resin cylinder 2. The inspection port 25 faces the end of the overlapping portion d which is a fusion bonding portion, and furthermore, the excess resin generated at the time of the fusion bonding of the overlapping portion d is allowed to enter to form the surplus portion 32. It is as large as possible.

According to the fusion bonding structure, since the bending of the resin tube 1 is restricted by the cylindrical sheath 24 extending to the resin cylindrical body 2 so as not to be broken, the fusion bonding portion is used. The situation where bending stress is extremely concentrated on the resin tube 1 at the end of a certain overlapped portion d is avoided, and at the same time, the bending deformation of the resin tube 1 is regulated by the sheath portion 24 so as not to break. Therefore, even if a large bending force is applied to the resin tube 1, the resin tube 1 does not break. The length of the sheath portion 24 is determined so as to be restricted within a range where the bending deformation of the resin tube 1 is not broken.

Further, the inspection port 25 is passed through the inspection port 25.
It is possible to visually determine whether or not the extra banking portion 32 is formed, whether or not it is formed, or whether or not it is insufficient. Therefore,
By utilizing this fact, it is possible to determine the quality of the joined state by visually checking the presence or absence of the extra bank 32 from the inspection port 25.

Next, an embodiment of a fusion bonding method for obtaining the fusion bonding structure shown in FIG. 3 will be described with reference to FIGS.

In this method, the amount of insertion of the resin tube 1 into the resin cylinder 2 and the length of the heating zone by the heater 8 are appropriately determined using the clamp tool 7. As shown in FIG. 1, a heating heater 8 is set in the resin pipe 1 in which the insertion margin is appropriately determined by using the clamp tool 7, and the length of the heating area is determined by the clamp tool 7.

Here, the resin cylinder 2 is partitioned into a sheath 24 on the tip side and an outer joint 26 adjacent to the sheath 24. The resin tube 1 is divided into an inner joint 16 overlapped with the outer joint 26 and a fitting portion 17 overlapped with the sheath 24 adjacent to the inner joint 16.

On the other hand, the heating heater 8 is provided with a range of the heating zone length of the resin tube 1 determined by the clamp tool 7, that is, the resin outer layer portion 12 of the entire length of the inner joint portion 16 of the resin tube 1. A function that can be heated and melted is required. In order to cope with this requirement, the heating heater 8 in the illustrated example is provided with a cylindrical resin tube side heating section 82. And
As shown in FIG. 1, the resin tube-side heating unit 82 is fitted to the resin tube 1 until it hits the clamp tool 7. On the other hand, the cylinder-side heating portion 83 provided in the heater 8 is required to have a function of heating and melting only the resin inner layer portion 22 and a part of the protrusion 23 of the outer joint portion 26 of the resin cylinder 2. In order to cope with this demand, the cylinder-side heating section 83 of the heater 8 shown in the figure is used.
Has a heat insulating portion 84 and a heater face portion 85 protruding from the heat insulating portion 84. The heat insulating portion 84 is formed slightly smaller in diameter than the heating portion 85, and a heat insulating material 86 is attached to the outer periphery thereof. Then, the cylinder-side heating section 83
Until the resin cylinder 2 hits the stepped portion 87 of the resin cylinder 2
When the cylinder-side heating section 83 is inserted into the
5 is in proximity to or in contact with the entire length of the outer joining portion 26 of the resin cylinder 2, and the heat insulating portion 84 is opposed to the sheath 24 of the resin cylinder 2. The length of the inner joint 16 of the resin tube 1 is
The length is equal to or slightly longer than the length of the outer joint portion 26 of the resin cylinder 2. In FIG. 1, reference numeral 80 denotes a heater face portion 8 of the resin tube heating portion 82 and the cylindrical body heating portion 83.
5 shows a heat-generating element such as a nichrome wire provided in FIG.

In this way, the inner resin portion 22 of the outer joint portion 26 of the resin cylinder 2 is heated and melted, and the inner joint portion 16 of the resin pipe 1 is melted.
After the heating and melting of the resin outer layer portion 12 are performed at the same time, the resin cylinder 2 from which the heater 8 has been removed is externally fitted into the resin pipe 1 in a press-fit manner. At this time, as shown in FIG. 2, the resin cylindrical body 2 is press-fitted until it hits the clamp tool 7 holding the resin pipe 1, so that the resin outer layer of the molten inner joint portion 16 of the resin pipe 1 is pressed. 12 and resin cylinder 2
The resin inner layer portion 22 of the outer joining portion 26 which has been melted is fused to each other at an overlapping portion A of the resin tube 1 and the resin tube body 2. 2 and the projection 23 is fused with the projection
3a is formed. In addition, the sheath portion 24 of the resin cylinder 2 is externally fitted to the fitting portion 17 of the resin tube 1 without being fused. The overlapping portion d, which is the fusion portion between the outer joint portion 26 and the inner joint portion 16 described above, is subsequently cured.

In this embodiment, the sheath 24 of the resin cylinder 2 is
An inspection port 25 is formed at the boundary between the outer joint 26 and the outer joint 26. The inspection port 25 is formed when the resin inner layer part 22 of the molten outer joint part 26 of the resin cylinder 2 and the resin outer layer part 12 of the molten inner joint part 16 of the resin pipe 1 are fitted. It is provided in order to allow excess resin to enter and form a surplus portion. Therefore, if the extra bank 32 is visually observed through the inspection port 25 at the time of fitting, the inspection port 25
When the surplus resin has entered and formed the extra embossed portion 32, it can be determined that the joining has been successfully performed, and when the extra embossed portion 32 is not formed or is only insufficiently formed, It is possible to determine that the connection is defective.

In FIG. 2, the dashed line indicates the fusion-bonded portion, and the solid line indicates the fusion-bonded portion.

In the description of FIGS. 1 to 9, the same or corresponding parts are denoted by the same reference numerals to facilitate understanding of the contents.

In the above-described embodiment, the connection port of the resin joint is exemplified as the resin cylinder 2, but the resin cylinder 2 may be the end of the resin pipe.

[0038]

As described above, according to the fusion bonding structure of the present invention, when a bending force is applied to the resin pipe or the resin cylinder that is fusion bonded to each other, the resin pipe may be broken. Disappears.

According to the fusion bonding method of the present invention, such a fusion bonding structure can be formed.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a set state of a heating heater in a fusion bonding method according to the present invention.

FIG. 2 is a partial cross-sectional view showing a state in which a resin cylinder and a resin pipe are fitted in a press-fit manner in the fusion bonding method according to the present invention.

FIG. 3 is a sectional view showing a fusion bonding structure according to the present invention.

FIG. 4 is a schematic perspective view showing a use state of a tool used in a conventional method.

5 is an enlarged partial sectional view of a main part of the tool of FIG. 4;

FIG. 6 is an explanatory diagram in a case where a length of a heating area of a resin pipe is determined by the tool of FIG. 4;

FIG. 7 is a partial cross-sectional view showing a set state of a heater for heating in a conventional fusion bonding method.

FIG. 8 is a partial cross-sectional view showing a state in which a resin cylindrical body and a resin tube are fitted in a press-fitting manner in a conventional fusion bonding method.

FIG. 9 is an enlarged sectional view of a main part of a conventional fusion bonding structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Resin pipe (the other side member) 2 Resin cylinder (one side member) 12 Resin outer layer part 16 Inner joint part 17 Fitting part 22 Resin inner layer part 24 Sheath part 25 Inspection port 26 Outer joint part D Overlapping part (fusion bonding) Location)

Claims (4)

[Claims] 1. One side member of a resin tube and a resin cylinder body which is a counterpart thereof is externally fitted to the other side member, and both are fused and joined at an overlapping portion. A cylindrical sheath portion protruding from the fusion bonding portion and externally fitted to the other side member is extended, and the sheath portion is bent at the end of the fusion bonding portion. A resin tube fusion-bonded structure characterized in that deformation is regulated within a range not to break. 2. An inspection port is formed in the one side member for forming an extra bulge portion by allowing excess resin which faces an end of the fusion bonding portion and which is generated at the time of fusion bonding of the overlapping portion to enter. The resin tube fusion joining structure according to claim 1, wherein 3. A resin tube fusion joining method in which one side member of a resin tube and a resin cylinder body which is the other side of the resin tube is externally fitted to the other side member and both are fused and joined at an overlapping portion. The one side member is divided into a sheath portion on the distal end side and an outer joint portion adjacent to the sheath portion, and the resin inner layer portion of the joint portion is heated and melted, and the other side member is overlapped with the outer joint portion. The two members are pressed into each other while the resin outer layer portion of the inner joint portion is heated and melted while being divided into an inner joint portion to be formed and a fitting portion which is adjacent to the inner joint portion and overlapped with the sheath portion. The inner resin portion of the molten outer joint portion of the one-side member and the outer resin layer portion of the molten inner joint portion of the other-side member are fused by fitting into one shape, and Externally fitting the sheath part to the fitting part of the other member,
And then curing the fusion joint between the outer joint portion and the inner joint portion. 4. A boundary portion between the sheath portion of the one-side member and the outer joint portion, wherein a resin inner layer portion of the molten outer joint portion of the one-side member and a molten inner joint portion of the other-side member. 2. The method according to claim 1, wherein an inspection port is provided for allowing excess resin generated when the resin outer layer portion is fitted to enter the resin portion to form a surplus portion.