JP6249131B1 - How to assemble pipe fittings - Google Patents

Abstract

A pipe joint assembly method capable of easily forming a pipe joint capable of relatively rotating a first flow path member and a second flow path member with a specified small torque.
The assembly method includes a first flow path member 2 having an outer cylinder portion 6 having an inward claw portion 7 formed on an inner peripheral surface, and a resin made of an outer claw portion 16 formed on an outer peripheral surface. This is applied to a pipe joint including the second flow path member 3 having the inner cylinder portion 12 and an in-core disposed inside the inner cylinder portion 12. In the first step, the inner cylinder part 12 is inserted into the outer cylinder part 6, and the outward claw part 16 of the inner cylinder part 12 is snap-engaged with the inward claw part 7 of the outer cylinder part 6. In the second step, the diameter expansion jig 20 having a diameter larger than the outer diameter of the in-core is inserted into the inner cylinder portion 12. In the third step, the diameter expansion jig 20 is taken out from the inner cylinder portion 12. In the fourth step, the in-core is inserted and arranged in the inner cylinder portion 12.
[Selection] Figure 5

Description

  The present invention relates to a method for assembling a pipe joint.

  As a pipe joint used for piping for water supply and hot water supply, etc., a first flow path member connected to an instrument such as a water tap, and a resin that can be connected to a water supply pipe etc. and engaged with the first flow path member 2. Description of the Related Art A known second flow path member and an in-core for realizing long-term engagement of the second flow path member with the first flow path member are known.

  In the pipe joint, the inner cylinder portion of the second flow path member is inserted into the outer cylinder portion of the first flow path member, and the outward claw portion formed on the outer peripheral surface of the inner cylinder portion is the outer cylinder. The second flow path member is prevented from coming out of the first flow path member by snap-engaging with an inward claw part formed on the inner peripheral surface of the part. In addition, an in-core is provided inside the inner cylinder part, and the in-core suppresses deformation of the inner cylinder part, and an outward claw part accompanying the deformation and an inward claw part of the outer cylinder part. Release of engagement is suppressed.

  Patent Document 1 discloses a method for assembling the pipe joint described above. In Patent Document 1, by inserting the inner cylindrical portion of the second flow path member into the outer cylindrical portion of the first flow path member, the outward claw portion formed on the outer peripheral surface of the inner cylindrical portion is Using the elasticity based on the fact that the tube portion is made of resin, the tube portion is snap-engaged with an inward claw portion formed on the inner peripheral surface of the outer tube portion. Then, after this snap engagement is performed, the in-core is inserted inside the inner cylinder portion.

Japanese Patent No. 5269178

Here, in order to increase the degree of freedom of connection to various devices (water faucets, water supply pipes, etc.), the pipe joint may have a structure in which the first flow path member and the second flow path member are relatively rotatable. Conceivable.
In this case, if the inner cylinder portion of the second flow path member is simply inserted and arranged in the outer cylinder portion of the first flow path member, it is necessary for the relative rotation of the first flow path member and the second flow path member. There is a risk that the torque to become unnecessarily large. Specifically, as described above, when the inward claw portion of the first flow path member and the outward claw portion of the second flow path member are snap-engaged, the inner cylinder portion of the second flow path member is reduced in diameter. It is inserted into the outer cylinder part of the first flow path member while being deformed. At this time, the outward claw portion formed on the outer peripheral surface of the inner cylinder portion of the second flow path member is pressed against the inward claw portion formed on the inner peripheral surface of the outer cylinder portion of the first flow path member and is unnecessary. It will deform | transform into 1 part and will contact | abut on the internal peripheral surface of the outer cylinder part of a 1st flow path member. As a result, the first flow path member and the second flow path member are difficult to rotate relative to each other, and in some cases, the first flow path member and the second flow path member may not be relatively rotatable.

  The present invention has been made in view of such circumstances, and an object thereof is to easily form a pipe joint capable of relatively rotating the first flow path member and the second flow path member with a specified small torque. An object of the present invention is to provide a method for assembling a pipe joint.

An assembly method of a pipe joint for solving the above-mentioned problem is that a first flow path member having an outer cylinder part in which an engaged part is formed on the inner peripheral surface, and an engaging part is formed on the outer peripheral surface. A second flow path member having an inner cylinder portion made of resin, and an in-core disposed inside the inner cylinder portion , wherein the first flow path member and the second flow path member are relatively rotatable. A pipe joint assembly method comprising: inserting the inner cylinder part into the outer cylinder part, and providing the engaging part of the inner cylinder part by the inner cylinder part being made of resin. A first step of snap-engaging the engaged portion of the outer cylinder portion using elasticity, and a diameter expanding jig having a diameter larger than the outer diameter of the in-core is inserted into the inner cylinder portion. A second step, a third step of taking out the diameter expansion jig, and a fourth step of inserting and arranging the in-core into the inner cylinder part.

  In the first step of the assembling method, the inner cylinder part is deformed in the diameter reducing direction as the inner cylinder part is inserted into the outer cylinder part. However, in the second step after the engaging portion of the inner tube portion and the engaged portion of the outer tube portion are snap-engaged, a diameter expansion jig is inserted into the inner tube portion, and the engaging portion is The outer peripheral surface of the inner cylinder part is pressed against the inner peripheral surface of the outer cylinder part having the engaged part so that the outer shape of the inner cylinder part is re-formed into a shape that follows the inner peripheral surface of the outer cylinder part. Become. Further, in the subsequent third step and fourth step, the above-mentioned diameter expansion jig is taken out, and an incore having a smaller outer diameter than that of the diameter expansion jig is inserted and arranged inside the inner cylindrical portion. The inner cylinder part in a state where the is formed is deformed so as to be reduced in diameter by its own elasticity, that is, in a direction away from the inner peripheral surface of the outer cylinder part.

  As described above, according to the above assembling method, the outer shape of the inner cylindrical portion is re-formed to follow the inner peripheral surface of the outer cylindrical portion through the insertion of the diameter expanding jig into the inner cylindrical portion, and thereafter the inner cylindrical portion By taking out the diameter-enlarging jig, the entire inner cylinder portion can be deformed so that the outer diameter becomes smaller. By forming the pipe joint by such an assembling method, it is possible to suppress a part of the outer peripheral surface of the inner cylinder part from hitting the inner peripheral surface of the outer cylinder part. Therefore, it is possible to easily form a pipe joint capable of relatively rotating the first flow path member and the second flow path member with a specified small torque.

  In the above assembly method, when the value obtained by dividing the outer diameter of the diameter expansion jig by the outer diameter of the in-core is “V”, the same value “V” satisfies the relational expression “1.025 ≦ V ≦ 1.075”. It is preferable that the above-mentioned diameter expansion jig having a value is used.

  According to the present invention, it is possible to easily form a pipe joint capable of relatively rotating the first flow path member and the second flow path member with a specified small torque.

Sectional drawing which shows the structure of the pipe joint with which the assembly method of one Embodiment is applied. (A) And (b) is sectional drawing which shows the execution aspect of a previous process. (A)-(c) is sectional drawing which shows the execution aspect of a 1st process. The side view of the diameter expansion jig used for the assembly of a pipe joint. Sectional drawing which shows the execution aspect of a 2nd process. Sectional drawing which shows the execution aspect of a 3rd process. (A) And (b) is sectional drawing which shows the execution aspect of a 4th process. The graph which shows the relationship between the elapsed time after completion of assembly of a pipe joint, and the rotatable torque of the pipe joint.

Hereinafter, an embodiment of a pipe joint assembling method will be described.
As shown in FIG. 1, a pipe joint 1 includes a cylindrical first flow path member 2 made of metal or resin, a resin-made second flow path member 3 engaged with the first flow path member 2, An in-core 4 made of metal or hard resin for realizing long-term engagement of the second flow path member 3 with the first flow path member 2. The pipe joint 1 is used for connecting a pipe material having a nominal diameter of “13A”.

  A male thread 5 for connecting the pipe joint 1 to an instrument such as a water tap is formed on the outer peripheral surface of the first flow path member 2 on the one end (lower end in FIG. 1) side. An outer cylinder portion 6 for attaching the second flow path member 3 is provided on the other end (upper end in FIG. 1) side of the first flow path member 2.

  An inner peripheral surface of the outer tube portion 6 in the first flow path member 2 plays a role as an engaged portion that is engaged with the second flow path member 3 in order from the upper end side of the first flow path member 2. A fitting groove 8 into which the facing claw portion 7, an engaging portion (an outward claw portion 16 described later) of the second flow path member 3 is fitted, and a housing groove 10 in which the seal ring 9 is housed are formed.

  The inward claw portion 7 protrudes from the inner peripheral surface of the outer cylindrical portion 6 toward the axis L of the first flow path member 2 and has an annular shape extending in the circumferential direction of the inner peripheral surface of the outer cylindrical portion 6. . An outer peripheral surface of a portion on the upper end side of the first flow path member 2 in the inward claw portion 7 is a tapered surface 7 a that decreases in diameter toward the inner depth of the first flow path member 2. On the other hand, the outer peripheral surface of the portion on the lower end side of the first flow path member 2 in the inward claw portion 7 is a cylindrical surface 7b extending in the axis L direction with the same diameter. Further, the lower end portion of the inward claw portion 7 is a vertical surface 7 c orthogonal to the axis L of the first flow path member 2.

  The fitting groove 8 is disposed adjacent to the inward claw portion 7 so that the vertical surface 7c of the inward claw portion 7 becomes one side wall. The outer peripheral surface of the lower end portion of the fitting groove 8 is a tapered surface 8a that decreases in diameter toward the inner depth (downward in FIG. 1) of the first flow path member 2, and the upper end portion of the fitting groove 8 The outer peripheral surface is a cylindrical surface 8b extending in the axis L direction with the same diameter.

The second flow path member 3 has two parts (a large diameter part 11 and an inner cylinder part 12) having different outer diameters.
The large-diameter portion 11 forms a portion on the one end portion (upper end in FIG. 1) side in the axis L direction of the second flow path member 3. A heating wire coil 13 is provided on the inner peripheral surface of the large diameter portion 11, and a pair of electrodes 14 connected to the heating wire coil 13 protrude outward from the outer peripheral surface of the large diameter portion 11. And by energizing the heating wire coil 13 with the resin water supply pipe inserted into the large diameter portion 11, the contact portion between the water supply pipe and the large diameter portion 11 is melted and joined together. It has become.

  The inner cylinder portion 12 forms a portion on the other end portion (lower end in FIG. 1) side in the axis L direction of the second flow path member 3 and is inserted inside the outer cylinder section 6 in the first flow path member 2. Has been placed. The outer diameter of the inner cylinder portion 12 is smaller than the outer diameter of the large diameter portion 11 and is the same as or slightly smaller than the inner diameter of the outer cylinder portion 6 in the first flow path member 2. On the outer peripheral surface of the inner cylinder portion 12, an outward claw portion 16 that serves as an engagement portion that snap-engages with the inward claw portion 7 (engaged portion) of the first flow path member 2 is formed. .

  The outward claw portion 16 has an annular shape extending in the circumferential direction of the outer peripheral surface of the inner cylinder portion 12. The outer peripheral surface of the portion on the lower end side of the second flow path member 3 in the outward claw portion 16 is a tapered surface 16 a that decreases in diameter toward the lower end of the second flow path member 3. On the other hand, the outer peripheral surface of the portion on the upper end side of the second flow path member 3 in the outward claw portion 16 is a cylindrical surface 16b extending with the same diameter in the axis L direction. Further, the upper end portion of the outward claw portion 16 is a vertical surface 16 c that is orthogonal to the axis L of the second flow path member 3. And when the inner cylinder part 12 of the 2nd flow path member 3 is attached inside the outer cylinder part 6 of the 1st flow path member 2, ie, when the outward claw part 16 snap-engages with the inward claw part 7. The vertical surface 16 c of the outward claw portion 16 is in a state of facing the vertical surface 7 c of the inward claw portion 7 in the axis L direction of the first flow path member 2.

  Under this state, the fact that the inner cylinder portion 12 of the second flow path member 3 comes out of the outer cylinder portion 6 of the first flow path member 2 means that the vertical surface 16c of the outward claw portion 16 and the inward claw portion 7 This is prevented by contact with the vertical surface 7c. Also, under this state, the first flow path member 2 and the second flow path member 3 can be rotated relative to each other about the axis L, and the outer tube portion 6 and the inner tube portion 12 are sealed by the seal ring 9. The space between is sealed.

  In addition, in this embodiment, it is the rotational torque which acts on the pipe joint 1 so that the 1st flow path member 2 and the 2nd flow path member 3 may be rotated relatively, and these 1st flow path member 2 and the 2nd flow path member The lowest value in the rotational torque range in which 3 actually rotates relative to each other is assumed to be a rotatable torque (in this embodiment, the design value is 0.50 [N · m]). In the pipe joint 1 of the present embodiment, the above-described rotatable torque is smaller than the tightening torque required when the first flow path member 2 is connected to a connection target instrument (for example, a water tap) using the male screw 5.

  Further, when the inner cylinder portion 12 of the second flow path member 3 is attached to the outer cylinder portion 6 of the first flow path member 2, the outward claw portion 16 of the second flow path member 3 is connected to the first flow path member 2. It is in a state of being fitted in the fitting groove 8. And in this embodiment, the shape of the outer peripheral surface of the inner cylinder part 12 of the 2nd flow path member 3 remove | excludes the part in which the accommodation groove | channel 10 in the inner peripheral surface of the outer cylinder part 6 of the 1st flow path member 2 was formed, The shape corresponds to the shape of the inner peripheral surface of the outer cylindrical portion 6 (specifically, substantially the same shape).

  The inside of the second flow path member 3 is a stepped through hole (first hole 18a, second hole 18b, third hole 18c) having a circular cross section and extending in the axis L direction. The first hole 18 a extends inside the upper end portion of the large diameter portion 11, and the second hole 18 b extends inside the lower end portion of the large diameter portion 11 and inside the upper end portion of the inner cylinder portion 12. The third hole 18c extends inside the portion on the lower end side of the inner cylinder portion 12. The inner diameter of the through hole is larger toward the upper end side ([the inner diameter of the first hole 18a]> [the inner diameter of the second hole 18b]> [the inner diameter of the third hole 18c)]. Further, the inner peripheral surface of the second hole 18b is a portion of the inner peripheral surface of the inner cylindrical portion 12 that is inward of the radially inward claw 16 and the radial direction of the receiving groove 10 (seal ring 9) of the first flow path member 2. The part which hits inward is included.

  The in-core 4 is inserted inside the inner cylinder portion 12 (specifically, the second hole 18b) in the second flow path member 3. The in-core 4 has a cylindrical shape and extends in the axial direction L of the second flow path member 3 inside the second hole 18b. A flange 17 is formed at the upper end of the in-core 4. And this flange 17 is contacting the level | step difference of the boundary part of the 1st hole 18a and the 2nd hole 18b inside the 2nd flow-path member 3, and the in-core 4 is a lower end with respect to the inner cylinder part 12 by the contact. It does not move too much to the side. The outer diameter (in this embodiment, the diameter = 12.5 mm) of the in-core 4 (specifically, the portion in contact with the inner peripheral surface of the second hole 18b) is the first diameter before the in-core 4 and the first flow path member 2 are attached. It is larger than the inner diameter (in this embodiment, the diameter = 12.4 mm) of the inner cylinder portion 12 (specifically, the second hole 18b) of the two flow path member 3. The outer diameter of the in-core 4 in this magnitude relationship is the diameter D3 shown in FIG. 7 (a), and the inner diameter of the inner cylinder portion 12 (second hole 18b) is the diameter D4 shown in FIG. 3 (a). It is.

  When the in-core 4 is inserted inside the inner cylindrical portion 12 in the second flow path member 3, the portion corresponding to the outward claw portion 16 in the inner cylindrical portion 12 is suppressed from being deformed in the reduced diameter direction, and thus the same deformation. Accordingly, release of the snap engagement between the outward claw portion 16 and the inward claw portion 7 is suppressed. Therefore, by inserting the in-core 4 into the inner cylinder portion 12 of the second flow path member 3, the snap engagement between the outward claw portion 16 and the inward claw portion 7 becomes strong, and the snap engagement Can be maintained over a long period of time.

Next, the procedure for assembling the pipe joint 1 described above will be described in detail.
In assembling the pipe joint 1, first, a pre-process is performed. In this pre-process, as shown by a white arrow in FIG. 2A, the seal ring 9 is elastically deformed and the opening of the outer cylinder part 6 is opened from the upper end side of the outer cylinder part 6 of the first flow path member 2. Insert inside. Thereby, as shown in FIG. 2B, the seal ring 9 is accommodated in the accommodation groove 10 of the outer cylinder portion 6 of the first flow path member 2.

  After such a pre-process, the first process is performed. In this first step, as shown in FIG. 3, the inner cylindrical portion 12 of the second flow path member 3 is inserted into the outer cylindrical portion 6 of the first flow path member 2. Thereby, using the elasticity provided with the outward nail | claw part 16 formed in the outer peripheral surface of the inner cylinder part 12 of the 2nd flow path member 3 by the said inner cylinder part 12 being resin, the 1st flow path The member 2 is snap-engaged with an inward claw portion 7 formed on the inner peripheral surface of the outer cylinder portion 6 of the member 2.

  Specifically, first, as indicated by a white arrow in FIG. 3A, the inner cylinder portion 12 of the second flow path member 3 is connected to one end portion of the outer cylinder portion 6 of the first flow path member 2 (FIG. 3). It is inserted into the outer cylinder part 6 from the upper end of (a). Thereby, as shown in FIG. 3B, the tapered surface 16 a of the outward claw portion 16 of the second flow path member 3 is in contact with the tapered surface 7 a of the inward claw portion 7 of the first flow path member 2. Become.

  And even after the taper surfaces 16a and 7a are in contact with each other, the first flow path member 2 so as to press-fit the inner cylinder part 12 of the second flow path member 3 into the outer cylinder part 6 of the first flow path member 2. And the 2nd flow path member 3 is pressed in the direction which mutually approaches. At this time, a portion of the inner cylinder portion 12 corresponding to the outward claw portion 16 is deformed so as to be reduced in diameter by being pushed by the tapered surface 7a.

  Thereafter, as shown in FIG. 3C, when the outward claw portion 16 of the second flow path member 3 gets over the inward claw portion 7 of the first flow path member 2, the inner cylindrical portion of the second flow path member 3. The portion corresponding to the outward claw portion 16 in 12 is restored (expanded) from the deformation by the repulsive force accompanying the deformation. By restoration from this deformation, the vertical surface 16c of the outward claw portion 16 and the vertical surface 7c of the inward claw portion 7 face each other, and the outward claw portion 16 of the second flow path member 3 is in the first flow. It comes to be snap-engaged with the inward claw portion 7 of the road member 2.

After such a first step, a second step is performed. In the second step, the diameter expansion jig 20 shown in FIG. 4 is inserted into the inner cylinder portion 12 of the second flow path member 3 in the state shown in FIG.
As shown in FIG. 4, the diameter expansion jig 20 has a stepped columnar shape. Specifically, in the diameter expanding jig 20, a portion on one side (lower side in FIG. 4) forms a small diameter insertion portion 21, and a portion on the other side (upper side in FIG. 4) has a relatively large diameter base. 22 is made. The boundary portion between the insertion portion 21 and the base portion 22 in the diameter expansion jig 20 is a stopper surface 23 that is orthogonal to the axis of the diameter expansion jig 20. The outer diameter of the insertion portion 21 of the diameter expanding jig 20 (diameter = 13.2 mm in this embodiment) is larger than the outer diameter of the in-core 4 (diameter = 12.5 mm in this embodiment).

  In the second step, as shown in FIG. 5, the stopper surface 23 of the diameter expanding jig 20 abuts against the end surface of the second flow path member 3 on the large diameter portion 11 side (upper side in FIG. 5). The insertion part 21 of the diameter expansion jig 20 is inserted into the inner cylinder part 12 up to the position. As a result, the insertion of the diameter expansion jig 20 to the position where the tip of the insertion part 21 of the diameter expansion jig 20 reaches the radially inward direction of the outward claw part 16 of the inner cylinder part 12 of the second flow path member 3. The part 21 is inserted into the inner cylinder part 12. At this time, since the insertion portion 21 of the diameter expanding jig 20 is inserted partway through the second hole 18b of the second flow path member 3, the inner diameter of the second hole 18b is the same at the portion where the insertion portion 21 is inserted. 21 will be spread directly. In the second step, the portion in which the inner diameter of the second hole 18b is directly pushed and expanded is the insertion direction of the diameter-expanding jig 20 (downward in FIG. 5) rather than the portion where the inner portion of the receiving groove 10 (seal ring 9) hits radially inward. The insertion portion 21 of the diameter expansion jig 20 is inserted into the inner cylinder portion 12 in a manner that becomes a portion on the near side.

  After the second step, the third step is performed. In this third step, as shown in FIG. 6, the diameter expansion jig 20 (see FIG. 5) inserted into the inner cylindrical portion 12 of the second flow path member 3 in the second step is used inside the inner cylindrical portion 12. Pull out and remove.

  After the third step, the fourth step is performed. In the fourth step, as shown in FIG. 7, the in-core 4 is inserted and arranged inside the inner cylinder portion 12 of the second flow path member 3. Specifically, in the fourth step, the in-core 4 is inserted into the inner cylindrical portion 12 as indicated by a white arrow in FIG. Then, as shown in FIG. 7B, when the flange 17 of the in-core 4 is inserted to a position where it comes into contact with the boundary portion between the large-diameter portion 11 and the inner tube portion 12 of the second flow path member 3, the inner tube portion The insertion of the in-core 4 into the 12 is completed. Thereby, the in-core 4 is in a state of being inserted into a portion including a portion corresponding to the radially inner side of the outward claw portion 16 on the inner peripheral surface of the inner cylinder portion 12 of the second flow path member 3.

Next, the effect | action by having employ | adopted the assembly method of the pipe joint 1 mentioned above is demonstrated.
In the assembling method of the present embodiment, as shown in FIG. 3C, the inner cylinder part is inserted along with the insertion of the inner cylinder part 12 of the second flow path member 3 into the outer cylinder part 6 of the first flow path member 2. 12, the portion where the outward claw portion 16 is formed and its periphery are deformed in the direction of diameter reduction. At this time, a part of the outward claw part 16 of the inner cylinder part 12 and its peripheral part are deformed so as to fall down to the rear side (upper side in FIG. 3C) in the insertion direction of the inner cylinder part 12. The outer shape of the cylindrical portion 12 is irregularly deformed. Therefore, after inserting the inner cylinder part 12 of the second flow path member 3 into the outer cylinder part 6 of the first flow path member 2, the outer peripheral surface of the inner cylinder part 12 and the inner peripheral surface of the outer cylinder part 6 are in contact with each other. There is a risk.

  In the pipe joint 1 of the present embodiment, the first flow path member 2 and the second flow path member 3 are relatively rotatable. Therefore, when the inner peripheral surface of the outer cylinder portion 6 of the first flow path member 2 and the outer peripheral surface of the inner cylinder portion 12 of the second flow path member 3 are in contact with each other as described above, these first flow path members 2 are used. And the rotational torque required in order to make the 2nd flow path member 3 rotate relatively will become large unnecessarily.

  However, in this embodiment, in the second step after the outward claw portion 16 of the inner cylinder portion 12 and the inward claw portion 7 of the outer cylinder portion 6 are snap-engaged, the inner core portion 12 is in-core. The diameter-expanding jig 20 having a diameter larger than 4 (specifically, its insertion portion 21) is inserted. As a result, as shown in FIG. 5, the inner cylindrical portion 12 of the second flow path member 3 is deformed so as to expand in diameter, and the outer peripheral surface of the inner cylindrical portion 12 having the outward claw portion 16 is inwardly directed claw portion. 7 and the inner circumferential surface of the outer cylinder portion 6 having the fitting groove 8.

  As described above, the shape of the outer peripheral surface of the inner cylindrical portion 12 of the second flow path member 3 is the same as that of the outer peripheral portion except for the portion where the accommodation groove 10 is formed on the inner peripheral surface of the outer cylindrical portion 6 of the first flow path member 2. It has a shape (substantially the same shape) corresponding to the shape of the inner peripheral surface of the cylindrical portion 6. Therefore, in the second step, the outer peripheral surface of the inner cylindrical portion 12 is pressed against the inner peripheral surface of the outer cylindrical portion 6, so that the outer shape of the inner cylindrical portion 12 is reshaped to follow the inner peripheral surface of the outer cylindrical portion 6. can do.

  Further, in the subsequent third step and fourth step, the diameter expansion jig 20 is pulled out from the inside of the inner tube portion 12 of the second flow path member 3 and the outer diameter is larger than the insertion portion 21 of the diameter expansion jig 20. The small in-core 4 is inserted and arranged inside the inner cylinder portion 12. Therefore, the inner cylinder part 12 in a state in which the outer shape is reshaped is deformed so as to be reduced in diameter (restored) by its own elasticity, that is, in a direction away from the inner peripheral surface of the outer cylinder part 6.

  As described above, according to the present embodiment, the outer shape of the inner cylindrical portion 12 follows the inner peripheral surface of the outer cylindrical portion 6 through the insertion of the diameter expanding jig 20 into the inner cylindrical portion 12 of the second flow path member 3. Then, by pulling out the diameter expansion jig 20 from the inner cylinder part 12 after that, the entire inner cylinder part 12 can be deformed so that the outer diameter becomes smaller. As a result, a part of the outer peripheral surface of the inner cylindrical portion 12 of the second flow path member 3 can be prevented from hitting the inner peripheral surface of the outer cylindrical portion 6 of the first flow path member 2. Therefore, it is possible to easily form the pipe joint 1 capable of relatively rotating the first flow path member 2 and the second flow path member 3 with a specified small torque (for example, about 0.55 N · m).

  The pipe joint 1 has a seal ring 9 disposed between the inner peripheral surface of the outer cylinder portion of the first flow path member 2 and the outer peripheral surface of the inner cylinder portion 12 of the second flow path member 3. The seal ring 9 supports the inner peripheral surface of the outer cylinder portion 6 and the outer peripheral surface of the inner cylinder portion 12, so that the displacement between the axis of the outer cylinder portion 6 and the axis of the inner cylinder portion 12 is suppressed. The relative positions of the outer cylinder part 6 and the inner cylinder part 12 can be maintained. Also by this, since the contact between the inner peripheral surface of the outer cylindrical portion 6 and the outer peripheral surface of the inner cylindrical portion 12 can be suppressed, smooth relative rotation of the first flow path member 2 and the second flow path member 3 is realized. can do.

  In the present embodiment, in the second step, the insertion portion 21 of the diameter expansion jig 20 is inserted partway through the second hole 18 b of the second flow path member 3. Therefore, after the diameter expansion jig 20 is pulled out in the third step, the inner diameter is not expanded on the back side of the second hole 18b in the insertion direction of the diameter expansion jig 20 (downward in FIG. 6). That is, a portion (inner diameter = 12.4 mm) having an inner diameter smaller than the outer diameter (diameter = 12.5 mm) of the in-core 4 remains. As a result, as shown in FIG. 7, in the fourth step, a part of the incore 4 is press-fitted into a portion having a small inner diameter in the second hole 18b. It is possible to suppress the dropout from the flow path member 3).

  Here, when the pipe joint 1 is connected to a connection target instrument (for example, a water faucet) using the male screw 5, a torsional moment may be applied to the pipe joint 1 by the rotation of the first flow path member 2. is there. If the pipe joint 1 is fixed to the connection target instrument in a state where such a torsional moment is applied, the connection target instrument, the pipe joint 1, and the water supply pipe fixed to the pipe joint 1 are fixed after the fixing. Internal stress is generated, and there is a possibility that the reliability of the piping structure including the pipe joint 1 is lowered.

  In this regard, in the pipe joint 1 of the present embodiment, the lowest value of the rotational torque range in which the first flow path member 2 and the second flow path member 3 are actually relatively rotated by being applied to the pipe joint 1 ( The rotation torque) is smaller than the tightening torque required when the first flow path member 2 is connected to the connection target instrument using the male screw 5. Therefore, even when the torsional moment is applied to the pipe joint 1 when the pipe joint 1 is connected to the connection object tool, the rotation for connection applied to the pipe joint 1 is completed before the connection is completed. The torque exceeds the rotatable torque, and the first flow path member 2 and the second flow path member 3 rotate relative to each other. Thereby, it can suppress that a torsion moment acts on the pipe joint 1 or a connection object instrument. In addition, since it is possible to prevent the internal stress from remaining in the pipe joint 1 or the connection target instrument after the pipe joint 1 is connected to the connection target instrument, the piping structure including the pipe joint 1 is highly reliable. Can be.

Hereinafter, the case where the pipe joint 1 is assembled without using the diameter expansion jig 20 will be considered.
Even when the pipe joint 1 is assembled without using the diameter expansion jig 20, after the outward claw portion 16 of the inner cylinder portion 12 and the inward claw portion 7 of the outer cylinder portion 6 are snap-engaged. By inserting and placing the in-core 4 inside the inner cylinder portion 12, the inner cylinder portion 12 is deformed (expanded diameter). Moreover, the shape of the inner cylinder portion 12 is restored (reduced in diameter) with the passage of time after completion of the assembly due to the elasticity of the inner cylinder portion 12 of the second flow path member 3. With this restoration, it is estimated that the rotatable torque gradually decreases.

  The inventor conducted an experiment for assembling the pipe joint 1 without using the diameter expansion jig 20 and measuring the relationship between the elapsed time and the above-described rotatable torque of the pipe joint 1. And even if it is a case where the pipe joint 1 is assembled without using the diameter expansion jig 20 from this experimental result, about two and a half years pass after the assembly, the design value ( 0.50 [N · m]) and the actual value are such that the user feels no difference (for example, the difference between the design value and the actual value is 0.20 [N · m]). It turned out to be smaller. Thus, when the pipe joint 1 is assembled without using the diameter expansion jig 20, until the shape of the second flow path member 3 is restored to such an extent that the rotatable torque is appropriately reduced. Takes a long time.

  Since the pipe joint 1 has a structure in which the first flow path member 2 and the second flow path member 3 can rotate relative to each other, the rotational torque of each pipe joint 1 is measured in order to confirm the function before shipment. It is desirable to perform an inspection. When performing such an inspection, if the pipe joint 1 is assembled without using the diameter expansion jig 20, the above inspection should be performed in a state where the rotatable torque of the pipe joint 1 has increased with the assembly. Since it cannot be obtained, the inspection cannot be performed properly. In this regard, by assembling the pipe joint 1 by the assembling method of the present embodiment, the first flow path member 2 and the second flow path member 3 can be relatively rotated with a small torque from an early stage after the assembly is completed. Therefore, the inspection can be properly performed.

Next, consideration will be given to the rotatable torque of the pipe joint 1 when an in-core one having a large diameter (diameter = 13.2 mm) is employed.
The inventor conducted an experiment to measure the rotatable torque with the diameter expansion jig 20 (the diameter of the insertion portion 21 = 13.2 mm) being inserted into the inner cylindrical portion 12 of the second flow path member 3. . As a result, the rotatable torque of the pipe joint 1 in this state is a larger value (2.40 [N · m]) than when the small-diameter incore 4 (diameter = 12.5 mm) is employed. I understood that.

  For this reason, even if an in-core having a large outer diameter is simply adopted and the inner cylinder portion 12 of the second flow path member 3 is expanded in diameter to adjust its outer shape, the above-described rotatable torque cannot be reduced. Is guessed. In the state where the in-core having a large outer diameter is press-fitted and the inner cylinder part 12 of the second flow path member 3 is expanded in diameter, the outer peripheral surface of the inner cylinder part 12 is the outer cylinder part 6 of the first flow path member 2. This is considered to be because the above-described rotatable torque is increased without being able to be restored (reduced diameter) while being pressed against the inner peripheral surface.

  For this reason, in order to suppress an increase in the rotatable torque of the pipe joint 1, not only the large diameter expanding jig 20 is inserted into the inner cylinder portion 12 of the second flow path member 3 (second step). ), Pulling out the diameter-enlarging jig 20 from the inner cylinder part 12 (third process), and inserting and arranging the in-core 4 having a smaller diameter than the diameter-enlarging jig 20 inside the inner cylinder part 12 (fourth process). ) Is important.

Next, the relationship between the outer diameter of the insertion portion 21 of the diameter expansion jig 20 used for assembling the pipe joint 1 and the rotatable torque of the pipe joint 1 after the assembly will be considered.
The inventor conducted an experiment of assembling the pipe joint 1 using a plurality of diameter expanding jigs having different outer diameters of the insertion portions and measuring the rotatable torque of each pipe joint 1 after the completion of the assembly. The measurement results are shown in FIG. In addition, each measurement data L1 (diameter of the insertion part = 12.5 mm), L2 (12.8 mm), L3 (13.0 mm), L4 (13.2 mm), L5 (13. 4 mm) and L6 (13.6 mm) have a sample number of “4” and indicate an average value thereof. By the way, by increasing the number of samples for each measurement data L1 to L6, it is considered that each measurement data becomes a smooth curve that converges to a common value as time passes.

  As is clear from FIG. 8, by using a diameter expansion jig whose outer diameter of the insertion portion is larger than the outer diameter of the in-core 4 (measurement data L2 to L6), the outer diameter of the insertion portion is the outer diameter of the in-core 4. Compared with the case where a diameter expansion jig equal to the diameter is employed (measurement data L1), the rotatable torque of the pipe joint 1 immediately after the assembly is completed is reduced.

  Further, when the outer diameter of the insertion portion of the diameter expansion jig used for assembling the pipe joint 1 is gradually increased (12.8 mm [measurement data L2] → 13.0 mm [same L3] → 13.2 mm [same L4] ]) Accordingly, the rotatable torque of the pipe joint 1 gradually decreases. When the outer diameter of the insertion portion 21 is 13.2 mm (measurement data L4), the rotatable torque becomes the smallest.

  When the outer diameter of the insertion portion of the diameter expansion jig is further increased beyond 13.2 mm (13.4 mm [measurement data L5] → 13.6 mm [same L6]), the rotation of the pipe joint 1 is accordingly performed. The possible torque gradually increases. This is because the inner cylindrical portion 12 is excessively expanded with the insertion of the insertion portion of the diameter expansion jig into the inner cylindrical portion 12 of the second flow path member 3, and the inner cylindrical portion 12 is restored (reduced diameter). This is considered to be because the degree of fitting between the outer peripheral surface of the inner cylindrical portion 12 and the inner peripheral surface of the outer cylindrical portion 6 remains large.

The items described in (Item A) to (Item C) below were confirmed from the experimental results shown in FIG. In the following (Item A) to (Item C), a value obtained by dividing the outer diameter D1 of the insertion portion of the diameter expansion jig by the outer diameter D2 of the in-core 4 is V (= D1 / D2).
(Item A) When the value V satisfies the relational expression “V> 1.00”, compared to the case where the value V is “1.00”, the rotatable torque of the pipe joint 1 immediately after the assembly is completed is Get smaller.
(Item B) When the value V satisfies the relational expression “1.025 ≦ V ≦ 1.075”, the rotatable torque of the pipe joint 1 immediately after completion of the assembly is suitably reduced.
(Item C) When the value V becomes a value of about “1.050”, the rotatable torque of the pipe joint 1 immediately after the completion of the assembly becomes the smallest.

  In the present embodiment, based on such experimental results, the outer diameter (diameter) of the insertion portion 21 of the diameter expansion jig 20 is set to “13.2 mm”, and the outer diameter (diameter) of the in-core 4 is set to “12.5 mm”. I have to. Thus, the pipe joint 1 that can relatively rotate the first flow path member 2 and the second flow path member 3 with a specified small torque at an early stage after the assembly is completed can be easily formed. Become.

As described above, according to the present embodiment, the following effects can be obtained.
(1) The pipe joint 1 that can relatively rotate the first flow path member 2 and the second flow path member 3 with a specified small torque can be easily formed.

<Modification>
The above embodiment may be modified as follows.
In the second step, the insertion portion 21 of the diameter expansion jig 20 is inserted into the inner cylinder portion 12 of the second flow path member 3, and the distal end of the insertion portion 21 faces the outward claw portion 16 of the inner cylinder portion 12. You may make it carry out in the aspect fastened to the position which does not reach inward in the radial direction. In short, it is only necessary that the diameter expansion jig 20 having the insertion portion 21 having an outer diameter larger than that of the in-core 4 can be inserted into the inner cylindrical portion 12 of the second flow path member 3.

  If the insertion of the diameter expansion jig 20 into the inner cylindrical portion 12 of the second flow path member 3 can be stopped at an appropriate position in the axial direction of the second flow path member 3, the diameter expansion The base 22 of the jig 20 may be omitted.

  In the third step, the method of taking out the diameter expansion jig from the inside of the inner cylinder part 12 is to adopt a method of moving the diameter expansion jig in the direction opposite to the direction in which it is inserted into the inner cylinder part 12 and pulling it out. Not limited to this, a method of moving in the same direction as the direction in which the diameter expanding jig is inserted and passing the inside of the inner cylindrical portion 12 may be adopted.

  The in-core 4 when the insertion into the inner cylinder portion 12 is completed does not necessarily have to extend over the entire axial direction of the second flow path member 3 inside the second hole 18b. You may make it extend only in a part of the said axial direction inside 18b. For example, it may extend only at the lower end side (lower side in FIG. 1) from the portion corresponding to the radially inner side of the outward claw portion 16 inside the second hole 18b, or at the upper end side (upward in FIG. 1) from the same portion. It is also possible to extend only on the side).

-You may make the internal diameter of the inner cylinder part 12 of the 2nd flow path member 3 and the outer diameter of the in-core 4 the same. Even with such a configuration, the in-core 4 can be mounted inside the inner cylinder portion 12.
If the gap between the first flow path member 2 and the second flow path member 3 is sealed, the seal ring 9 is between the inner peripheral surface of the outer cylinder portion and the outer peripheral surface of the inner cylinder portion. It is not limited to being disposed, but can be disposed at any position such as disposed between the tip of the inner cylinder portion 12 (lower end in FIG. 1) and the inner surface of the first flow path member 2.

  An engagement recess extending annularly in the circumferential direction is formed on one of the inner peripheral surface of the outer cylinder portion of the first flow path member and the outer peripheral surface of the inner cylinder portion of the second flow path member, and the other is annular in the circumferential direction The above assembling method can also be applied to a pipe joint having a structure in which engagement protrusions extending in the direction are formed and the engagement protrusions and the engagement recesses are snap-engaged.

  -The assembly method of the said embodiment is applicable also to the pipe joint used for the connection of the pipe material whose nominal diameter is "16A". In addition, the assembling method of the above embodiment can also be applied to pipe joints used for connecting pipe materials having nominal diameters other than “13A” and “16A”.

<Appendix>
The technical idea grasped from the embodiment and the modified examples will be additionally described below.
(A) a first flow path member having an outer cylindrical portion having an engaged portion formed on the inner peripheral surface, and a second having a resin inner cylindrical portion having an engaging portion formed on the outer peripheral surface. An assembly method of a pipe joint comprising a flow path member,
The inner cylinder part is inserted into the outer cylinder part, and the engagement part of the inner cylinder part is utilized for the engagement of the outer cylinder part by utilizing elasticity provided by the inner cylinder part being made of resin. A first step of snap-engaging with the engaging portion;
A second step of inserting a diameter expansion jig having a diameter larger than the inner diameter of the inner cylinder part into the inner cylinder part;
And a third step of pulling out the diameter expansion jig.

  DESCRIPTION OF SYMBOLS 1 ... Pipe joint, 2 ... 1st flow path member, 3 ... 2nd flow path member, 4 ... Incore, 5 ... Male screw, 6 ... Outer cylinder part, 7 ... Inward claw part, 7a ... Tapered surface, 7b ... Cylindrical surface , 7c ... vertical surface, 8 ... fitting groove, 8a ... tapered surface, 8b ... circumferential surface, 9 ... seal ring, 10 ... receiving groove, 11 ... large diameter portion, 12 ... inner cylinder portion, 13 ... heating wire coil , 14 ... Electrode, 16 ... Outward claw, 16a ... Tapered surface, 16b ... Cylindrical surface, 16c ... Vertical surface, 17 ... Flange, 18a ... First hole, 18b ... Second hole, 18c ... Third hole, 20 ... Diameter expansion jig, 21 ... Insertion part, 22 ... Base part, 23 ... Stopper surface.

Claims (2)

A first flow path member having an outer cylinder portion having an engaged portion formed on the inner peripheral surface, and a second flow path member having a resin inner cylinder portion having an engagement portion formed on the outer peripheral surface. And an in-core disposed inside the inner cylindrical portion, and a method of assembling a pipe joint in which the first flow path member and the second flow path member are relatively rotatable ,
The inner cylinder part is inserted into the outer cylinder part, and the engagement part of the inner cylinder part is utilized for the engagement of the outer cylinder part by utilizing elasticity provided by the inner cylinder part being made of resin. A first step of snap-engaging with the engaging portion;
A second step of inserting a diameter expansion jig having a diameter larger than the outer diameter of the in-core into the inner cylindrical portion;
A third step of taking out the diameter expansion jig;
And a fourth step of inserting and arranging the in-core into the inner cylinder portion. The method of assembling a pipe joint according to claim 1,
When the value obtained by dividing the outer diameter of the diameter expansion jig by the outer diameter of the in-core is “V”, the value “V” is a value that satisfies the relational expression “1.025 ≦ V ≦ 1.075”. A method for assembling a pipe joint, wherein the diameter expansion jig is used.