JP7365176B2 - fitting - Google Patents

Description

The present invention relates to a resin joint.

Conventionally, resin joints are known, for example, as described in Patent Documents 1 and 2 below. This joint is joined to a metal member such as a valve or a conversion joint, for example. The joint includes a sleeve pipe joined to the member.
Generally, one end of the two ends of the sleeve tube is joined to the member. The other end is joined to another resin pipe via an electric fusion joint.

JP2014-88933A JP2014-66328A

Since this type of joint is installed on-site, such as in a building under construction, it is desired to improve its workability.

The present invention was made in view of the above-mentioned circumstances, and an object of the present invention is to provide a joint with high workability.

In order to solve the above problems, the present invention proposes the following means.
A joint according to the present invention is a joint made of resin that is joined to a metal member, and includes a sleeve pipe that is joined to the member and an electrically fused portion that is joined to the sleeve pipe. The length is 150 mm or less, and there is no protrusion extending in the circumferential direction on the inner peripheral surface of the sleeve tube.

Since the electric fusion part is joined to the sleeve tube, there is no need to combine the sleeve tube and the electric fusion joint on site. Furthermore, the length of the sleeve tube is 150 mm or less, making it suitable for work in narrow spaces as a joint. Therefore, workability can be improved.
There is no protrusion extending in the circumferential direction on the inner peripheral surface of the sleeve tube. Therefore, this type of protrusion does not obstruct the flow of fluid, and the fluid flows smoothly within the sleeve tube.

A gate mark may be provided on the outer peripheral surface of the electrically fused portion.

The gate mark is not on the outer circumferential surface of the sleeve tube but on the outer circumferential surface of the electrically fused part. Therefore, when joining the sleeve tube to the member, the joining is not hindered by the gate marks.

There may be no gate marks on the outer circumferential surface of the sleeve tube.

There are no gate marks on the outer circumferential surface of the sleeve tube. Therefore, when joining the sleeve tube to the member, the joining is not hindered by the gate marks.

The electric welding part includes a socket part and a terminal provided on the outer peripheral surface of the socket part, and a parting line is provided on the outer peripheral surface of the sleeve pipe and extends in the axial direction of the sleeve pipe. and may be arranged on the same straight line as the terminal.

A parting line is provided on the outer peripheral surface of the sleeve tube, extends in the axial direction of the sleeve tube, and is arranged on the same straight line as the terminal. Therefore, the terminals can be aligned, etc. using the tapering line as an index.

A parting line may be provided on the outer circumferential surface of the joint between the sleeve tube and the electrically fused portion, and may extend in the circumferential direction.

A parting line is provided on the outer circumferential surface of the joint between the sleeve tube and the electrically fused portion, and extends in the circumferential direction. Therefore, when joining the sleeve tube to the member, the joining is not hindered by the parting line.

A parting line may be provided on the inner circumferential surface of the joint between the sleeve tube and the electrically fused portion, and may extend in the circumferential direction.

A parting line is provided on the inner circumferential surface of the joint between the sleeve tube and the electrically fused portion, and extends in the circumferential direction. Therefore, when joining the sleeve tube to the member, the joining is not hindered by the parting line.

The sleeve tube and the electrically fused portion may be fused.

The sleeve tube and the electrically fused portion are fused together. In other words, among the cores of the mold, the core of the sleeve tube (hereinafter also referred to as the first core) and the core of the electrically fused portion (hereinafter also referred to as the second core) are formed by different cores. Thereby, for example, the second core can be used in other joints in which only the sleeve tube is different in size among the sleeve tube and the electrically fused portion. Furthermore, for example, the first core can also be used in other joints in which only the size of the electrically welded part differs between the sleeve tube and the electrically welded part.

According to the present invention, a joint with high workability can be provided.

FIG. 2 is a side view showing a joint according to the present invention, in which the joint and the valve body are joined together in a partially sectional view. FIG. 2 is a side view showing a joint according to the present invention, in which the joint and the valve body are joined together in a partially sectional view. FIG. 2 is a partially sectional side view of the joint according to the present invention. FIG. 2 is a partially sectional side view of the joint according to the present invention. FIG. 1 is a partially cross-sectional side view of a mold, showing a first example of a method for manufacturing a joint according to the present invention. A second example of the method for manufacturing a joint according to the present invention is shown, in which (a) is a partially sectional side view taken along a plane passing through the tube axis Q of the mold, and (b) is a terminal forming portion of the mold. It is a sectional view perpendicular to the longitudinal direction in . FIG. 7 is a partially cross-sectional side view of a mold, showing a third example of the method for manufacturing a joint according to the present invention. FIG. 7 is a partially cross-sectional side view of a mold, showing a fourth example of the method for manufacturing a joint according to the present invention. It is a side view which shows the modified example of the joint based on this invention, and shows the state where the joint and the conversion joint were joined. It is a sectional view showing a modified example of the joint according to the present invention, and showing a state in which the joint and the conversion joint are joined. FIG. 7 is a partially sectional side view of a modified example of the joint according to the present invention. It is a side view which shows the modification of the joint based on this invention.

Embodiments of the present invention will be described below with reference to the drawings.

[Joint]
As shown in FIGS. 1 to 3, the joint 1 of this embodiment includes a sleeve tube 2 and an electrically fused portion 3 joined to the sleeve tube 2.

FIG. 1 shows a joint according to the present embodiment, and is a partially sectional side view of a state in which the joint and the valve body are joined. FIG. 2 shows the joint of this embodiment, and is a partially sectional side view of the state in which the joint and the valve body are joined. FIG. 3 is a partially sectional top view of the joint of this embodiment. Note that although Figures 1 and 2 show a state in which the joint is joined to the valve body, Figure 3 shows a state in which the joint is not joined to the valve body (a state before it is joined to the valve body). It shows.

The joint 1 of this embodiment is a joint made of resin, and is used by being joined to a metal valve body 100, for example, as shown in FIG. FIG. 1 shows a state in which a pair of joints 1 are connected via a valve body 100. The valve body 100 includes a valve box 101 and a pair of connection sockets 102 extending on both sides with the valve box 101 in between. The valve box 101 is provided with an operation section such as a handle (not shown). An annular uneven portion 103 is formed on the outer periphery of the connection socket 102 .

As the resin constituting the joint 1, a resin composition containing polyolefin such as polyethylene as a main component can be used.

For example, as shown in FIG. 1, the sleeve tube 2 is joined to a connection socket 102 of a valve body 100. The sleeve tube 2 is joined to the connection socket 102 by pushing the concavo-convex portion 103 of the connection socket 102 into one longitudinal end portion 2A of the sleeve tube 2 (the end opposite to the electrically fused portion 3). Further, a cylindrical press-fit ring 50 is fitted into the outer periphery of the sleeve tube 2 joined to the connection socket 102. Thereby, the sleeve tube 2 is firmly joined to the connection socket 102.
As shown in FIG. 3, before the sleeve tube 2 is joined to the valve body 100, the sleeve tube 2 has the same diameter over its entire length. As shown in FIG. 2, when the one end portion 2A of the sleeve tube 2 is press-fitted into the connection socket 102, the connection socket 102 pushes it outward in the radial direction and expands its diameter.

The length L of the sleeve tube 2 (the length in the direction in which it is joined to the electrically fused portion 3) is 150 mm or less. If the length of the sleeve tube 2 is equal to or less than the above upper limit, it is suitable for working in a narrow space. Therefore, workability can be improved. It is preferable that the length L of the sleeve tube 2 is less than or equal to the total length of the EF clamp and the supporting metal fittings (both not shown). Note that the EF clamp is a clamp used when electrically welding the electrically fused part 3 and another pipe, and the support fitting is a fitting that supports the sleeve tube 2 during this joining. . That is, it is preferable that the sleeve tube 2 has a length that allows electrical fusion between the joint 1 and the other tube.
Note that the length L of the sleeve tube 2 is defined as the distance from the open end edge of the sleeve tube 2 (the edge on the opposite side from the electric welding part 3 of both ends of the sleeve tube 2) to the sleeve tube 2 and the electric welding part 3. This refers to the length in the direction of the tube axis Q up to the joint.

As shown in FIGS. 1 to 3, the inner circumferential surface 2a of the sleeve tube 2 has no protrusions extending in the circumferential direction. Therefore, this type of protrusion does not obstruct the flow of fluid, and the fluid flows smoothly within the sleeve tube 2.

The inner diameter of the sleeve tube 2 is not particularly limited, but is adjusted as appropriate depending on the inner diameter of the member (for example, the connection socket 102) to be joined to the sleeve tube 2. Further, the outer diameter of the sleeve tube 2 is not particularly limited, but is appropriately adjusted depending on the outer diameter of the member (for example, the connection socket 102) to be joined to the sleeve tube 2. Note that these inner diameters and outer diameters mean the inner diameter and outer diameter in a state before the sleeve tube 2 is joined to the valve body 100, as shown in FIG.

As shown in FIGS. 1 to 3, the electric welding part 3 has a cylindrical socket part 3A at one end in the tube axis Q direction. Further, the electrically welded part 3 has an enlarged diameter part 3B whose diameter increases as the distance from the sleeve tube 2 increases. The enlarged diameter portion 3B is a so-called tapered portion. The socket portion 3A of the electric welding portion 3 is joined to the sleeve tube 2 via the enlarged diameter portion 3B. That is, the inner diameter of the socket portion 3A of the electrically fused portion 3 is larger than the inner diameter of the sleeve tube 2.
Helical heating wires 5 are embedded in a part of the region (hereinafter also referred to as "heating region") 3C of the inner circumferential surface of the socket portion 3A.
A pair of terminal pins (terminals) 6 that protrude outward in the radial direction are present on the outer circumferential surface of both ends of the socket portion 3A of the electrically fused portion 3 in the direction of the tube axis Q. The terminal pin 6 is electrically connected to the heating wire 5. When a cable connector of an energizing device (not shown) is attached to the terminal pin 6 and the heating wire 5 is energized, the heating wire 5 generates heat.
An indicator 7 is present on the outer peripheral surface of the heating area 3C. The indicator 7 is connected to the bottom surface of a recess 7a recessed in the radial direction. When the fusion is properly performed, the indicator 7 protrudes radially outward and is exposed from the recess 7a.

In the direction of the tube axis Q, there are cold zones on both sides of the heating area 3C where no heating wire is present. Hereinafter, the cold zone existing on the sleeve tube 2 side with respect to the heating area 3C will be referred to as an inner cold zone 3D, and the cold zone existing on the end surface side of the electrically fused portion 3 will be referred to as an outer cold zone 3E. Further, the length of the inner cold zone 3D in the tube axis Q direction is La, the length of the heating region 3C in the tube axis Q direction is Lb, and the length of the outer cold zone 3D in the tube axis Q direction is Lc.
The length (La+Lb+Lc) of the socket portion 3A of the electrically fused portion 3 in the direction of the tube axis Q is designed according to the application of the joint 1.

In the joint 1 of this embodiment, the terminal pin 6 is inserted into the socket 3A of the electric welding part 3 with another pipe (not shown) made of a resin composition made of the same material as the joint 1. The heating wire 5 is energized to fuse the electrically welded portion 3 and another tube in the heating region 3C, thereby making it possible to join them together. Insert the other tubes until they hit the enlarged diameter section 3B.
In the heating region 3C of the socket part 3A of the electrically welded part 3, the inner circumferential surface of the socket part 3A and the outer circumferential surface of another tube are fused and integrated.

According to the joint 1 of this embodiment, since the electrically fused portion 3 is joined to the sleeve tube 2, there is no need to combine the sleeve tube and the electrically fused joint at the site. In addition, the sleeve tube 2 has a length of 150 mm or less, making it suitable for work in a narrow space as a joint. Therefore, workability can be improved. Moreover, there is no protrusion extending in the circumferential direction on the inner circumferential surface 2a of the sleeve tube 2. Therefore, this type of protrusion does not obstruct the flow of fluid, and the fluid flows smoothly within the sleeve tube 2.

By the way, the joint 1 of this embodiment is integrally formed by injection molding. That is, the sleeve tube 2 and the electrically fused portion 3 are integrally formed within the same mold. In other words, the sleeve tube 2 and the electrically fused portion 3 are not individually molded and then joined together.
Here, when butt joining (butt joining) the individually molded sleeve tube 2 and the electrically fused portion 3, a protrusion is formed at the joint part, and this protrusion is also formed on the inner circumferential surface of the sleeve tube 2. . Since the joint 1 of this embodiment is integrally formed by injection molding, the protrusions are not formed, and as a result, as described above, no protrusions are formed on the inner circumferential surface of the sleeve tube 2.
However, gate marks and parting lines PL are generally formed in the joint 1 formed by injection molding in this way. Depending on the position of the gate mark and the parting line PL, the function of the joint 1 may be affected.

Here, in the joint 1 of this embodiment, a configuration in which no gate marks are provided in the joint 1 can be realized by a manufacturing method described later. In the joint 1 of the present embodiment, gate marks may be provided on the outer circumferential surface of the electrically fused portion 3 during injection molding of the joint 1. In other words, it is preferable that there are no gate marks on the outer peripheral surface of the sleeve tube 2. Since the gate marks are provided not on the outer peripheral surface of the sleeve tube 2 but on the outer peripheral surface of the electrically fused part 3, when the sleeve tube 2 is joined to the above-mentioned member (for example, the connection socket 102), Bonding is not inhibited. For example, when fitting the press-fit ring 50 onto the outer periphery of the sleeve tube 2, the fit of the press-fit ring 50 is not hindered by gate marks.

In the joint 1 of this embodiment, the parting line PL formed when injection molding the joint 1 is provided on the outer peripheral surface of the sleeve pipe 2 and extends in the axial direction of the sleeve pipe 2 (pipe axis Q direction), In addition, it may be arranged on the same straight line as the pair of terminal pins (terminals) 6. In the half-sectional view shown in FIG. 2, a parting line PL is arranged along the tube axis Q. Thereby, the positioning of the terminal pin (terminal) 6 and the operation part of the valve body 100, and the pair of joints 1 connected via the valve body 100 can be performed using the parting line as an index. Further, the electric welding section 3 can easily weld other resin tubes.

In the joint 1 of this embodiment, the parting lines PL1 and PL2 are the outer circumferential surface or inner circumferential surface of the electrically welded portion 3, or the outer circumferential surface or the inner circumferential surface of the joint portion 8 between the sleeve tube 2 and the electrically welded portion 3. It may be provided on the surface and may extend in the circumferential direction. In the modified joint 1A shown in FIG. 4, a parting line PL1 is provided on the inner peripheral surface of the joint, and a parting line PL2 is provided on the outer peripheral surface of the joint. Thereby, when joining the sleeve tube 2 to the above-mentioned member (for example, the connection socket 102), the joining is not hindered by the parting line 10. That is, when the parting lines PL1 and PL2 are formed on the outer circumferential surface or inner circumferential surface of the sleeve tube 2, there is a possibility that they may interfere with the connection socket 102 and the press-fit ring 50. In this case, the connection between the sleeve tube 2 and the connection socket 102 may be weakened.

[Method of manufacturing joint 1]
A method for manufacturing the joint 1 of this embodiment will be explained in detail.
5 to 8 are diagrams showing examples of the manufacturing method (first to fourth examples) of the joint 1 of this embodiment.
In the first to third examples of the manufacturing method of the joint 1 according to the present embodiment shown in FIGS. It has a step (first step) of supplying it to a mold to obtain a tubular body (precursor of the joint 1). In these examples, after this step, the joint 1 is obtained through a step of processing the tubular body (second step).
On the other hand, in a fourth example of the manufacturing method of the joint 1 of the present embodiment shown in FIG. , has a step of obtaining the joint 1 itself.

(First example)
In a first example, a method for manufacturing a joint 1 in which no gate marks are formed will be described. Note that this first example is an example for explaining the position of the gate in the mold, and can be combined with other examples described later as long as no contradiction occurs.
FIG. 5 shows a first example of the method for manufacturing the joint 1 of this embodiment, and is a side view of a mold partially in section.
In the example shown in FIG. 5, the mold 300 has a core 310 and a cavity 320. Between the core 310 and the cavity 320 there is a space 330 in the shape of the joint 1.
The core 310 has an outer shape (outer surface shape) that is the same as the inner surface shape of the joint 1 . That is, the core 310 has a first portion 311 having an outer shape that is the same as the inner shape of the sleeve tube 2, and a second portion 312 that has an outer shape that is the same as the inner shape of the electrically fused portion 3. The cavity 320 has an inner shape that is the same as the outer shape (outer surface shape) of the joint 1 . That is, the cavity 320 has a first portion 321 having an inner surface having the same shape as the outer shape of the sleeve tube 2, and a second portion 322 having an inner surface having the same shape as the outer shape of the electrically fused portion 3.

In this example, the space of the mold 300 is A resin composition is injected into the tube 330 to form a tubular body 400, which is a precursor of the joint 1. The tubular body 400 has a sleeve tube 410 that becomes the sleeve tube 2, an electrically fused section 420 that becomes the electrically fused section 3, and a disk gate section 430. By cutting out the disk gate portion 430 from the tubular body 400, no gate marks remain on the outer circumferential surface of the sleeve tube 2 or the outer circumferential surface of the electrically welded portion 3, as in the joints shown in FIGS. 1 to 3. Furthermore, the resin composition is uniformly injected into the mold 300, and no weld lines, which are traces of confluence of the resin composition in the mold 300, are formed on the sleeve tube 2, so the sleeve tube 2 can be molded into a perfect circle. . Further, a disk gate 340 is provided at one end of the cavity 320 (the end of the first portion 311 on the opposite side from the second portion 322).
In this example, since the core 310 is pulled out from the other end of the cavity 320 (the end opposite to the first part 321 in the second part 322), the outer diameter of the core 310 increases toward the disk gate 340 side. It's getting thinner. Therefore, the inner diameter of the sleeve tube 2 becomes smaller from the connection part with the electrically fused part 3 toward the disk gate 340 side. For example, if the cavity 320 is a split type and the outer diameter of the sleeve tube 2 is constant from the connection part with the electric welding part 3 toward the disk gate 340 side, the wall thickness of the sleeve tube 2 is It becomes larger toward the disk gate 340 side from the connection part with part 3.

(Second example)
In the second example, the parting line PL is provided on the outer circumferential surface of the sleeve tube 2, extends in the axial direction of the sleeve tube 2 (tube axis Q direction), and is aligned with the pair of terminal pins (terminals) 6. A method for manufacturing the joint 1 arranged on a line will be described. Note that this second example is an example for explaining the position of the cavity 520, and can be combined with other examples as long as no contradiction occurs. Although the following description assumes injection according to the first example, the form of resin injection is not limited to this.
FIG. 6 shows a second example of the method for manufacturing the joint 1 of this embodiment, in which (a) is a side view partially taken in section along a plane passing through the tube axis Q of the mold, and (b) is a side view of the mold. FIG. 3 is a cross-sectional view perpendicular to the longitudinal direction of the terminal forming portion of the mold.
In the example shown in FIG. 6, the mold 500 has a core 510 and a cavity 520. Between the core 510 and the cavity 520 there is a space 530 in the shape of the joint 1.
The core 510 has an outer shape (outer surface shape) that is the same as the inner shape of the joint 1 . That is, the core 510 has a first portion having an outer shape that is the same as the inner shape of the sleeve tube 2 and a second portion having an outer shape that is the same as the inner shape of the electrically fused portion 3 . The cavity 520 has an inner shape that is the same as the outer shape (outer surface shape) of the joint 1 . That is, the cavity 520 has a first portion 521 having an inner surface having the same shape as the outer shape of the sleeve tube 2 and a second portion 522 having an inner surface having the same outer shape as the outer shape of the electrically welded portion 3 . Further, the cavity 520 can be divided into a lower mold 520A and an upper mold 520B at a parting line 501 along the axial direction of the mold 500.

As shown in FIG. 6A, a pair of terminal forming portions 523 are arranged in the cavity 520 on the same straight line as the parting line 501, forming a portion for providing the terminal pin 6 described above.

In this example, as in the first example, a resin composition is injected into the space 520 of the mold 500 to mold the tubular body 400, which is a precursor of the joint 1. When the tubular body 400 is taken out from the mold 500 by separating the lower mold 520A and the upper mold 520B of the cavity 520 from the tubular body 400, a parting line is formed in the tubular body 400 at a position corresponding to the parting line 501. PL is formed. Thereafter, by cutting out the disk gate portion 430 from the tubular body 400, the joint 1 as shown in FIG. 3 is manufactured.

(Third example)
In a third example, a method for manufacturing a joint 1A in which a parting line PL2 is provided on the outer circumferential surface of the joint between the sleeve tube 2 and the electrically fused portion 3 and extends in the circumferential direction will be described. Note that this third example is also an example for explaining the position of the cavity 620, and can be combined with other examples (for example, the first example) as long as no contradiction occurs. Although the following description assumes injection according to the first example, the form of resin injection is not limited to this.
FIG. 7 shows a third example of the method for manufacturing the joint 1 of this embodiment, and is a side view of a mold partially in section.

In the example shown in FIG. 7, the mold 600 has a core 610 and a cavity 620. Between the core 610 and the cavity 620 there is a space 630 in the shape of the joint 1.
The core 610 has an outer shape (outer surface shape) that is the same as the inner shape of the joint 1 . That is, the core 610 has a first portion 611 having an outer shape that is the same as the inner shape of the sleeve tube 2, and a second portion 612 having an outer shape that is the same as the inner shape of the electrically fused portion 3. The cavity 620 has an inner shape that is the same as the outer shape (outer surface shape) of the joint 1 . That is, the cavity 620 has a first portion 621 having an inner surface having the same shape as the outer shape of the sleeve tube 2 and a second portion 622 having an inner surface having the same outer shape as the outer shape of the electrically fused portion 3 . Furthermore, the cavity 620 can be divided into a first portion 621 and a second portion 622 along a parting line 623. The parting line 623 is provided along the boundary between the sleeve tube 410 and the electrically fused portion 420 of the tubular body 400. More specifically, due to the drawing taper of the mold 600, the second portion 622 corresponds to the socket portion 3A of the electric welding portion 3, and the first portion 621 corresponds to the other portions including the sleeve tube 2. corresponds to the part. That is, the outer diameter of the sleeve tube 2 gradually decreases as it moves away from the electrically fused portion 3, and the outer diameter of the socket portion 3A also gradually decreases as it moves away from the sleeve tube 2.

In this example, a resin composition is injected into the space 630 of the mold 600 to mold the tubular body 400, which is a precursor of the joint 1. When the tubular body 400 is taken out from the mold 600 by separating the first portion 621 and the second portion 622 of the cavity 620 from the tubular body 400, a part is formed in the tubular body 400 at a position corresponding to the parting line 623. A running line PL2 is formed. Thereafter, by cutting the disk gate portion 430 from the tubular body 400, the joint 1 in which the parting line PL2 is formed at the position shown in FIG. 4 is manufactured.

(Fourth example)
In a fourth example, a method for manufacturing a joint 1A in which a parting line PL1 is provided on the inner circumferential surface of the joint between the sleeve tube 2 and the electrically fused portion 3 and extends in the circumferential direction will be described.
FIG. 8 shows a fourth example of the method for manufacturing the joint 1A of the present embodiment, and is a side view of a mold partially in section.

In the example shown in FIG. 8, the mold 700 has a core 710 and a cavity 720. Between the core 710 and the cavity 720 there is a space 730 in the shape of the joint 1 .
The core 710 has an outer shape (outer surface shape) that is the same as the inner shape of the joint 1 . That is, the core 710 has a first portion 711 having an outer shape that is the same as the inner shape of the sleeve tube 2 and a second portion 712 having an outer shape that is the same as the inner shape of the electrically fused portion 3 . Further, the core 710 can be divided into a first portion 711 and a second portion 712 at a parting line 713. The parting line 713 is provided along the boundary between the sleeve tube 410 and the electrically fused portion 420 of the tubular body 400. More specifically, the first portion 711 corresponds to the entire sleeve tube 2, and the second portion 712 corresponds to the entire electrically fused portion 3. That is, the inner diameter of the sleeve tube 2 gradually increases as the distance from the sleeve tube 2 increases, and the inner diameter of the electric weld section 3 also gradually increases as the distance from the sleeve tube 2 increases.
The cavity 720 has an inner shape that is the same as the outer shape (outer surface shape) of the joint 1 . That is, the cavity 720 has a first portion 721 having an inner surface having the same shape as the outer shape of the sleeve tube 2 and a second portion 722 having an inner surface having the same outer shape as the outer shape of the electrically welded portion 3 . Further, the cavity 720 can be divided into a first portion 721 and a second portion 722 at a parting line 723. The parting line 723 is provided along the boundary between the sleeve tube 410 and the electrically fused portion 420 of the tubular body 400. More specifically, due to the drawing taper of the mold 700, the second portion 722 corresponds to the socket portion 3A of the electric welding portion 3, and the first portion 721 corresponds to the other portions including the sleeve tube 2. corresponds to the part. That is, the outer diameter of the sleeve tube 2 gradually decreases as it moves away from the electrically fused portion 3, and the outer diameter of the socket portion 3A also gradually decreases as it moves away from the sleeve tube 2.

In this example, a resin composition is injected into the space 730 of the mold 700 to mold the tubular body 400, which is a precursor of the joint 1. By dividing the mold 700 along the parting lines 713 and 723, the core 510 and the cavity 720 can be easily removed from the joint 1A. As a result, a joint 1A in which a parting line PL1 is formed at a position as shown in FIG. 4 is manufactured.

Note that, as in this example, when the parting lines PL1 and PL2 are provided on the outer circumferential surface or the inner circumferential surface of the joint between the sleeve tube 2 and the electric welding part 3, the parting surface of the mold is located between the sleeve tube 2 and the electric welding part 3. This is the joint part with the fitting part 3. That is, a mold for forming the sleeve tube 2 (first portions 711, 721, hereinafter also referred to as the first core) and a mold for forming the electrically fused portion 3 (second portions 712, 722, hereinafter also referred to as the second core). ) are considered to be different molds. Thereby, for example, the second core can be used in other joints in which only the sleeve tube 2 is different in size among the sleeve tube 2 and the electrically fused portion 3. Furthermore, for example, the first core can also be used in other joints in which only the size of the electrically welded part 3 is different between the sleeve tube 2 and the electrically welded part 3.

[Modified example]
FIG. 9 is a side view showing a modified example of the joint of this embodiment, showing a state in which the joint and the conversion joint are joined. FIG. 10 shows a modification of the joint of this embodiment, and is a sectional view showing a state in which the joint and the conversion joint are joined. FIG. 11 is a partially sectional side view of a modification of the joint of this embodiment. FIG. 12 is a side view showing a modification of the joint of this embodiment.
In FIGS. 9 to 12, the same components as those of the joint shown in FIGS. 1 to 3 are denoted by the same reference numerals, and the description thereof will be omitted. The joint 1B of this embodiment has a substantial structure similar to that of the previous embodiment, except that the objects to be connected are different.

(First modification)
The joint 1B of this embodiment is used by being joined to a conversion joint 200, for example, as shown in FIGS. 9 and 10. The conversion joint 200 has a first connection part 201 and a second connection part 202 that extend in the longitudinal direction via an annular protrusion 203 . An annular uneven portion 204 is formed on the outer periphery of the first connecting portion 201 . An annular uneven portion 205 is formed on the outer periphery of the second connecting portion 202 .

The sleeve tube 2 is joined to the first connecting portion 201 of the conversion joint 200, for example, as shown in FIGS. 9 and 10. By pushing the first connecting portion 201 of the conversion joint 200 into one end portion 2A of the sleeve tube 2, the sleeve tube 2 is joined to the first connecting portion 201. Furthermore, a cylindrical press-fit ring 60 is fitted into the outer periphery of the sleeve tube 2 joined to the first connecting portion 201. Thereby, the sleeve tube 2 is firmly joined to the first connecting portion 201.

(Second modification)
As shown in FIG. 11, the joint 800 includes a sleeve tube 802 and an electrically fused portion 803 joined to the sleeve tube 802.
As the resin constituting the joint 800, the same resin as the resin constituting the joint 1 can be used.

The electric welding part 803 is a socket as shown in FIG. The electric fusion part 803 has a cylindrical socket part 803A and a cylindrical socket part 803B at both ends in the tube axis Q direction. The electric welding section 803 includes a heating wire 805, a terminal pin 806, and an indicator 807, like the electric welding section 3 described above.

After the sleeve tube 802 is inserted into the socket 803A of the electrically welded part 803, it is fused and joined to the electrically welded part 803 by generating heat in the heating wire 805. A resin tube can be joined to the socket part 803B of the electric fusion part 803 as well as to the socket part 803A.

The length of a portion 802A of the sleeve tube 802 that protrudes from the electrically fused portion 803 (hereinafter referred to as a "protrusion") is 150 mm or less. If the length of the protrusion 802A is equal to or less than the above upper limit, it is suitable for working in a narrow space. Therefore, workability can be improved.

Moreover, as shown in FIG. 11, the inner circumferential surface 802a of the sleeve tube 802 does not have a protrusion extending in the circumferential direction. Therefore, this type of protrusion does not obstruct the flow of fluid, and the fluid flows smoothly within the sleeve tube 802.

(Third modification)
As shown in FIG. 12, in the joint 1, a fastening band 900 may be provided at the socket portion 3A of the electric welding portion 3. The fastening band 900 has a tubular main body portion 801 and a threaded portion 802.
By fitting the main body part 901 into the outer peripheral surface of another resin pipe 1000 inserted into the socket part 3A and tightening the threaded part 902, the pipe 1000 can be made stronger against the electric welding part 3. Can be joined to.

(Other variations)
In the joint 1 of this embodiment, unevenness may be provided on the outer circumferential surface of the socket portion 3A of the electric fusion part 3 so that the joint 1 can be easily held. This makes it difficult for the tube axis to move when press-fitting the valve body 100 and the conversion joint 200 into the sleeve tube 2.

In the joint 1 of this embodiment, it is preferable that the nominal diameter of the sleeve tube 2 is 50 mm or less (outer diameter 63 mm or less, inner diameter 50 mm or less). When the nominal diameter is small, the proportion of the inner surface protrusion of the sleeve pipe 2 in the water passage area is higher than when the nominal diameter is large, but in this embodiment, there is no protrusion on the inner surface, so even if the nominal diameter is small, the pressure loss is small. suppressed.
Further, it is preferable that the length of the electrically fused portion 3 in the direction of the tube axis Q is 100 mm or less. This makes it suitable for working in narrow spaces as a joint.

In the joint 1 of this embodiment, the inner and/or outer surface of the end of the sleeve tube 2 that is to be joined to the connection socket 102 or the like may be chamfered. The chamfering makes it easy to insert the tip of the uneven portion 103 into the sleeve tube 2, and especially when the end of the sleeve tube 2 is thick, it is easy to push the uneven portion 103 into the sleeve tube 2.

Since the joint of the present invention has high workability, it can be used for joining water pipes in narrow spaces, for example, pipe spaces in buildings such as buildings.

1,800 Joint 2,802 Sleeve pipe 3,803 Electric fusion part 3A Socket part 4 Unevenness 5,805 Heating wire 6,806 Terminal pin 7,807 Indicator 8 Joint part PL, PL1, PL2 Parting line

Claims (5)

A resin joint joined to a metal member,
a sleeve tube joined to the member;
an electrically fused portion joined to the sleeve tube,
The length of the sleeve tube is 150 mm or less,
There is no protrusion extending in the circumferential direction on the inner peripheral surface of the sleeve tube,
The electric fusion part includes a socket part and a terminal provided on the outer peripheral surface of the socket part,
A joint in which a parting line is provided on the outer peripheral surface of the sleeve tube, extends in the axial direction of the sleeve tube, and is disposed on the same straight line as the terminal. A resin joint joined to a metal member,
a sleeve tube joined to the member;
an electrically fused portion joined to the sleeve tube,
The length of the sleeve tube is 150 mm or less,
There is no protrusion extending in the circumferential direction on the inner peripheral surface of the sleeve tube,
A joint in which a parting line is provided on an outer circumferential surface of a joint between the sleeve pipe and the electrically welded part and extends in the circumferential direction. The joint according to claim 1 or 2, wherein gate marks are provided on the outer peripheral surface of the electrically fused portion. The joint according to any one of claims 1 to 3, wherein there are no gate marks on the outer circumferential surface of the sleeve pipe. The joint according to any one of claims 1 to 4 , wherein a parting line is provided on an inner circumferential surface of a joint between the sleeve tube and the electrically fused portion and extends in the circumferential direction.

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