JP2024118608A - Pipe Fittings - Google Patents

Abstract

[Problem] The objective is to provide a pipe fitting that does not damage the pipe or the installer's hands when inserting the pipe, and allows the inner core to be visually confirmed during installation. [Solution] A pipe fitting comprising a fitting body, an inner core arranged on the inner peripheral surface of the fitting body, and a cap 102 arranged on the end of the fitting body, the end surface 102c of the cap 102 having a plurality of through recesses 200, at least one of the through recesses 200 having a gate mark 201. [Selected Figure] Figure 3

Description

The present invention relates to a pipe joint.

Pipe joints have been used to connect pipes used for water supply, hot water supply, or air conditioning equipment in buildings (see, for example, Patent Document 1). The pipe joint includes a cylindrical joint body with a receiving recess formed on its inner circumferential surface, a retaining ring that is received in the receiving recess and contacts the outer circumferential surface of a pipe inserted inside the joint body, and an annular spacer that is disposed on the inner circumferential surface of the joint body. The spacer is sandwiched between a first retaining ring and a second retaining ring. The first retaining ring is also sandwiched between a base and the spacer. A synthetic resin cap is attached to the joint body. The synthetic resin cap is generally manufactured by injection molding.

JP 2021-139495 A

In the injection molding process of the cap, gate marks can remain. If a gate recess is provided on the inner peripheral surface of the cap and a gate mark is formed inside it, as in the pipe fitting of Patent Document 1, the pipe can be damaged when the pipe is inserted due to the remaining gate mark, making it impossible to stop water flow. Also, in the process of inserting the pipe of the pipe fitting at the construction site, when the core is inserted into the cap, the core protrudes only about 1 mm from the end face of the cap, which is difficult to see, which is an issue.

The present invention was made in consideration of these problems, and aims to provide a pipe fitting that is less likely to damage the pipe when the pipe is inserted into the pipe fitting at the construction site, and that allows the inner core to be visually confirmed.

In order to solve the above problems, the present invention proposes the following means.
The pipe fitting of the present invention comprises a fitting body, an inner core arranged on the inner surface of the fitting body, and a cap arranged on an end of the fitting body, wherein the end face of the cap has a plurality of through recesses, and at least one of the through recesses has a gate mark.

According to this invention, the end face of the cap has multiple through-hole recesses, and at least one of the through-hole recesses has a gate mark, so the pipe is less likely to be damaged when it is inserted at the construction site. In addition, the inner core can be seen through the through-hole recesses.

In the above pipe joint, an end face of the cap and the through recess may have a partially concave structure.
According to this invention, since the end face of the through recess has a partially concave structure, a step is formed when the cap is viewed in vertical cross section, and the in-core can be visually confirmed.

In the above pipe joint, the through recesses may be disposed at three or more equal locations on the end face of the cap.
According to this invention, the gate mark can be seen from any direction when the cap is viewed from, so the pipe is less likely to be damaged when it is inserted at the construction site. Furthermore, the in-core can be seen from any direction when the cap is viewed from.

In the above pipe joint, the through recess may occupy 2% to 20% of the area of the end face of the cap.
According to this invention, in the injection molding process of the cap, the synthetic resin tends to flow evenly from the through recess in the end face of the cap, so that the cap can be molded to have a perfect circle, for example.

In the above pipe joint, the through recess may have a depth of 0.5 mm to 3 mm.
According to this invention, by making the through recess deeper, a larger torque can be applied to the through recess in the molding process of the pipe joint, and the cap can be easily tightened onto the pipe joint.

In the above pipe joint, the length of the notch in the circumferential direction of the through recess may be 1.0 mm to 4.0 mm.
According to this invention, the strength of the cross-shaped joint jig used in the molding process of the pipe joint can be ensured.

The present invention provides a pipe fitting that is less likely to damage the pipe when the pipe is inserted into the pipe fitting at the construction site and allows the in-core to be visually confirmed.

FIG. 1 is a perspective view showing a pipe joint according to an embodiment of the present invention, the perspective view being partially cross-sectional. FIG. 2 is a perspective view showing a component configuration of a pipe joint according to an embodiment of the present invention. FIG. 2 is a perspective view showing the shape of a cap according to an embodiment of the present invention. FIG. 2 is a perspective view showing the shape of a cap according to an embodiment of the present invention. 1 is a partial vertical cross-sectional view of a cap according to an embodiment of the present invention. 1 is a portion of a vertical cross-sectional view of a cap when an in-core according to one embodiment of the present invention is inserted. FIG. 2 is a perspective view showing a female thread portion of a cap according to an embodiment of the present invention.

Hereinafter, a pipe joint 100 according to one embodiment of the present invention will be described with reference to Figures 1 and 2. Figure 1 shows a pipe joint 100 including a joint body 101, an annular packing 103a arranged on the inner peripheral surface of the joint body 101, an annular base member 103b arranged on the inner peripheral surface of the joint body 101, an annular spacer 104c arranged on the inner peripheral surface of the joint body 101, a first retaining ring 104a arranged on the inner peripheral surface of the joint body 101, a second retaining ring 104b arranged on the inner peripheral surface of the joint body 101, a resin in-core 105 arranged on the inner peripheral surface of the joint body 101, and a cap 102 arranged on the end of the joint body 101.
The pipe joint 100 according to the present embodiment is a member for connecting a plurality of pipes (pipes) for water intake, hot water supply, or air conditioning equipment in a building. The pipe joint 100 and the pipes connected to the pipe joint 100 constitute a piping structure.

The pipe joint 100 includes a cylindrical joint body 101 and a cap 102 provided on an end of the joint body 101 .
In the following description, the direction along the central axis of the joint body 101 is referred to as the axial direction, and the direction intersecting the central axis in a plan view of the joint body 101 from the axial direction is referred to as the radial direction. Also, the direction going around the central axis in the plan view is referred to as the circumferential direction.

A step 113 is formed on the inner peripheral surface of the joint body 101 at the end in the axial direction. The step 113 protrudes radially inward from the inner peripheral surface of the joint body 101. The step 113 is provided over the entire circumference in the circumferential direction. In the step 113, the inner diameter of the joint body 101 is gradually (step-like) reduced from the outside to the inside in the axial direction. An in-core 105 formed separately from the joint body 101 abuts against the step 113.
Hereinafter, the portion of the joint body 101 from the end face of the joint body 101 to the step 113 will be referred to as the open end of the joint body 101.

An outer flange portion 101b and a male thread portion 101c are formed on the outer peripheral surface of each of both axial ends of the joint body 101.
The outer flange portion 101b protrudes radially outward from the joint body 101. The outer flange portion 101b extends around the entire outer circumferential surface of the joint body 101.
The male thread portion 101c is formed on a portion of the outer peripheral surface of the joint body 101 that is located axially outward from the outer flange portion 101b (i.e., closer to the end of the joint body 101).

1 and 2, the cap 102 is cylindrical in shape with an outer diameter that decreases stepwise in the axial direction. The cap 102 includes a first tube 102a having an internal thread formed on its inner circumferential surface, and a second tube 102b that is positioned outward of the first tube 102a in the axial direction.
The first tube 102a is screwed onto the male thread portion 101c. A step 102d is provided at a portion of the inner circumference of the cap 102 that corresponds to the boundary between the first tube 102a and the second tube 102b. The step 102d extends over the entire circumference. The step 102d contacts or is close to an end face of the joint body 101 that faces outward in the axial direction.

The second cylinder 102b has a smaller diameter than the first cylinder 102a and extends outward in the axial direction from the first cylinder 102a.
In the pipe joint 100, an accommodating recess 106 for accommodating the water stop portion 103 and the fixing portion 104 is formed between the joint body 101 and the cap 102. The accommodating recess 106 is formed between the step 102d and an end face of the joint body 101 facing outward in the axial direction. The accommodating recess 106 extends around the entire circumference in the circumferential direction.

The joint body 101 is formed, for example, by injection molding of a synthetic resin material, or by cutting, casting, or forging of a metal material.
The cap 102 is formed, for example, by injection molding of a synthetic resin material, or by cutting, casting, or forging of a metal material.
The synthetic resin material can be arbitrarily selected based on quality design according to the application, for example, cross-linked polyethylene, polybutene, polyvinyl chloride (PVC), polysulfone resin (PSU), polycarbonate resin (PC), polyamide resin (PA), polyacetal resin (POM), polyphenylsulfone resin (PPSU), polyphenylene sulfide resin (PPS), glass fiber reinforced PPS, polyvinylidene fluoride (PVDF), etc. In addition, other processing methods such as cutting and fusion may be used.
The metal material can be arbitrarily selected from stainless steel, low alloy steel, carbon steel, low temperature carbon steel, low temperature alloy steel, brass, gunmetal, aluminum alloy, magnesium alloy, etc., based on quality design according to the application.

At each axial end of the pipe fitting 100, a packing 103a (sealing member), a base member 103b, a retaining ring 104a (first retaining ring), a spacer 104c, and a retaining ring 104b (second retaining ring) are provided in that order toward the end of the fitting body 101. That is, the fixing portion 104 is located closer to the end than the water stop portion 103.
The packing 103a and the base member 103b constitute a watertight portion 103. The watertight portion 103 prevents the contents of the pipe P from leaking out from the pipe joint 100.
The retaining ring 104a, the spacer 104c and the retaining ring 104b constitute the fixing portion 104. The pipe P inserted into the pipe joint 100 is fixed to the pipe joint 100 by the fixing portion 104.

The gasket 103a (sealing member) is disposed on the inner peripheral surface of the joint body 101. In the illustrated example, one gasket 103a is provided, but multiple gaskets 103a may be provided at intervals in the axial direction. The gasket 103a is annular with a circular cross section. The gasket 103a extends over the entire circumference in the circumferential direction. In the illustrated example, an O-ring is used as the gasket 103a. The gasket 103a may be made of rubber materials such as ethylene propylene diene rubber (EPDM), fluororubber (FKM), vinyl methyl silicone rubber (VMQ), acrylonitrile butadiene rubber (NBR), styrene butadiene rubber (SBR), and chloroprene rubber (CR).

The base member 103b is disposed between the packing 103a and the retaining ring 104a. The base member 103b prevents the packing 103a from coming into contact with the retaining ring 104a. The base member 103b is formed in an annular shape. The base member 103b extends over the entire circumference in the circumferential direction. The base member 103b is fitted into the open end of the joint body 101. The base member 103b contacts a first step, which is a step provided on the inner peripheral surface of the joint body 101. The base member 103b is hooked from the outside in the axial direction to the first step of the joint body 101. The inner diameter of the base member 103b is larger than the inner diameter of the packing 103a.
The base member 103b is formed, for example, by injection molding of a synthetic resin material, or by cutting, casting, or forging of a metal material.
The synthetic resin material can be arbitrarily selected based on quality design according to the application, for example, cross-linked polyethylene, polybutene, polyvinyl chloride (PVC), polysulfone resin (PSU), polycarbonate resin (PC), polyamide resin (PA), polyacetal resin (POM), polyphenylsulfone resin (PPSU), polyphenylene sulfide resin (PPS), glass fiber reinforced PPS, polyvinylidene fluoride (PVDF), etc. In addition, other processing methods such as cutting and fusion may be used.
The metal material can be arbitrarily selected from stainless steel, low alloy steel, carbon steel, low temperature carbon steel, low temperature alloy steel, brass, gunmetal, aluminum alloy, magnesium alloy, etc., based on quality design according to the application.

The retaining rings 104a, 104b (first retaining ring, second retaining ring) and the spacer 104c are arranged on the axial outside of the base member 103b. The retaining rings 104a, 104b and the spacer 104c are arranged in the accommodation recess of the joint body 101. The accommodation recess is located axially outside of the first step. The retaining rings 104a, 104b and the spacer 104c are arranged in the accommodation recess with some axial play. The retaining ring 104a, the spacer 104c and the retaining ring 104b are arranged in this order from the axial outside to the axial inside. The spacer 104c is arranged in the accommodation recess, sandwiched axially between the retaining rings 104a and 104b.

Furthermore, as shown in FIG. 3 or FIG. 4, the end surface 102c of the cap 102 has a plurality of through recesses 200, and at least one of the through recesses 200 has a gate mark 201. The plurality of through recesses 200 may be arranged evenly in three or more places in the circumferential direction. In FIG. 3, the through recesses 200 are arranged evenly in four places in the circumferential direction. In FIG. 4, the through recesses 200 are arranged evenly in eight places in the circumferential direction. As a result, even when the pipe P is inserted into the cap 102 at the construction site, the remaining part of the gate mark 201 is on the end surface 102c of the cap 102, not on the inner surface of the cap 102, so that the pipe P is less likely to be damaged. Therefore, water leakage due to damage to the pipe P can be prevented. Furthermore, when the through recesses 200 are arranged evenly in three or more places, the gate mark 201 can be seen from any direction, front, back, left, or right, so that construction can be performed more reliably without damaging the pipe P.

As shown in FIG. 5, the end faces 202 of the multiple through recesses 200 at the end face 102c of the cap 102 are partially concave. The through recesses 200 are rectangular in a front view from the radial direction. As a result, when the cap 102 is viewed in a vertical section, a step is generated between the end face 102c and the end face 202. This step is the depth of the through recess 200. When the pipe P is inserted, the in-core 105 is designed to protrude several millimeters at the end face 102c of the cap 102. However, by providing a step between the end face 102c and the end face 202, even when the pipe P is inserted as shown in FIG. 6, the step functions as a window, allowing the installer to visually confirm that the in-core 105 has been inserted. Since the pipe joint 100 may be poorly installed if the in-core 105 is not inserted, the installer can perform installation more reliably by visually confirming that the in-core 105 has been inserted.

The cap 102 is manufactured by injection molding. The synthetic resin cap 102 is formed by pouring synthetic resin vertically from the end face 102c side of the cap 102. When manufacturing the pipe joint 100, the cap 102 is tightened to the joint body 101 using, for example, a cross-shaped joint jig as the final process. In other words, the cap 102 is tightened to the joint body 101 with the above-mentioned components placed in the accommodation recess of the joint body 101. At this time, when the joint jig is rotated in the circumferential direction with the joint jig fitted into the through recess 200, the joint jig catches on the cap 102, and the cap 102 is attached to the joint body 101.

If the depth of the through recess 200 is less than 0.5 mm, the installer cannot visually confirm that the in-core 105 has been inserted sufficiently. On the other hand, if the depth of the through recess 200 is 3 mm or more, the vertical cutout of the cap 102 becomes large, which may weaken the strength of the cap 102 itself against impact. Therefore, the depth of the through recess 200 is preferably 0.5 mm to 3 mm, and more preferably 0.5 mm to 2 mm. By making the depth of the through recess 200 0.5 mm to 3 mm, a large torque can be applied to the through recess 200 during the installation process of the pipe fitting 100, making it easy to tighten the cap 102 to the pipe fitting 100.

As shown in FIG. 7, a female thread portion 203 is provided on the inside of the cap 102. The female thread portion 203 is a member that is fitted into the male thread portion 101c when constructing the pipe joint. Since the synthetic resin is evenly poured vertically from the end face 102c side of the cap 102 through the multiple through recesses 200, residual stress after injection molding remains in the vertical direction of the cap 102. On the other hand, residual stress is unlikely to remain in the inner diameter direction of the cap 102. Therefore, the female thread portion 203 is molded in a perfect circle. By making the female thread portion 203 perfect, it becomes possible to tighten the male thread portion 101c more smoothly. By setting the ratio of the area occupied by the through recesses 200 to 2% to 20% of the end face 102c of the cap 102, it is possible to provide multiple through recesses 200 and ensure the contact area with the seal material that covers the entire surface of the cap 102. It is more preferable that the ratio of the area occupied by the through recesses 200 is 3% to 15%.

Furthermore, it is preferable that the length of the notch in the circumferential direction of the through recess 200 is 1.0 mm to 4.0 mm. If the length of the notch in the circumferential direction of the through recess 200 is less than 1.0 mm, the strength of the cross joint jig used to tighten the cap 102 when installing the pipe joint 100 will be reduced. If the length of the notch is 4.0 mm or more, the contact area with the sealing material that covers the entire surface of the cap 102 will be reduced. The sealing material is a member that prevents the inner core 105 from coming off from inside the pipe joint 100 when the pipe joint 100 is distributed on the market as a product.

In addition, the components in this embodiment may be replaced with well-known components as appropriate without departing from the spirit of the present invention.

The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the examples described below, and various modifications are possible without departing from the gist of the present invention.

(Example)
In the embodiment, the area ratio of the through recesses 200 in the end face 102c of the cap 102 was measured when the through recesses 200 were provided at four equal locations, and when the through recesses 200 were provided at eight equal locations. The joint calibers used were 10A, 13A, 16A, and 20A. The results are shown in Tables 1 and 2. Table 1 shows the results of the measurement in the example of FIG. 3 in which the through recesses 200 are provided at four equal locations, and Table 2 shows the results of the measurement in the example of FIG. 4 in which the through recesses 200 are provided at eight equal locations.

As shown in Tables 1 and 2, by providing multiple through recesses 200 evenly on the end surface 102c of the cap 102, the area occupied by the through recesses 200 was 2% to 20% even when various sizes of fitting diameters were used.

100 Pipe joint 101 Joint body 101b Outer flange portion 101c Male thread portion 102 Cap 102a First cylinder 102b Second cylinder 102c End surface 102d Step 103 Water stop portion 103a Gasket 103b Base member 104 Fixing portion 104a Stop ring 104b Stop ring 104c Spacer 105 In-core 106 Accommodating recess 113 Step 200 Through recess 201 Gate mark 202 End surface 203 Female thread portion P Pipe

Claims (6)

A joint body,
an in-core disposed on an inner peripheral surface of the joint body;
a cap disposed on an end of the fitting body,
The end surface of the cap has a plurality of through recesses;
At least one of the through recesses has a gate mark. The pipe fitting according to claim 1, wherein the end face of the cap has a partially concave end face. The pipe fitting according to claim 1 or 2, wherein the through recesses are arranged at three or more equal locations on the end surface of the cap. The pipe fitting according to claim 1 or 2, in which the area of the end face of the cap occupied by the through recess is 2% to 20%. The pipe fitting according to claim 1 or 2, in which the depth of the through recess is 0.5 mm to 3 mm. The pipe fitting according to claim 1 or 2, in which the length of the notch in the circumferential direction of the through recess is 1.0 mm to 4.0 mm.

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