JP7614573B2 - Pipe Fittings - Google Patents

Description

The present invention relates to a pipe joint.

Figure 5 shows the pipe joint 101 described in Patent Document 1. In the pipe joint 101, a first seal ring 109 and a second seal ring 111 are used to ensure watertightness between the pipe 102 and the pipe. The first seal ring 109 and the second seal ring 111 are housed in a seal portion 108 provided in the joint body 104. In the seal portion 108, a spacer ring 110 is disposed between the first seal ring 109 and the second seal ring 111 to prevent them from directly contacting each other.

The joint body 104 is made of synthetic resin, and due to mold restrictions, it is difficult to form separate seal sections that accommodate the first seal ring 109 and the second seal ring 111 alone (particularly to form the rear seal section that accommodates the first seal ring 109 in a groove shape), so the above-mentioned structure using the spacer ring 110 is adopted.

JP 2018-168980 A

However, as shown in FIG. 6, when the pipe 102 is inserted obliquely into the pipe fitting 101, the spacer ring 110 receives the insertion force of the pipe 102 unevenly at a portion of the circumferential direction, and the spacer ring 110 is tilted relative to the first seal ring 109. If the inclination of the spacer ring 110 relative to the first seal ring 109 becomes excessive, a portion of the circumferential direction of the first seal ring 109 is excessively pressed toward the back and radially inward (pressing force F), which causes the portion to protrude from the seal portion 108.

The object of the present invention is to provide a pipe fitting in which the first seal ring is less likely to protrude from the seal portion when the pipe is inserted.

In order to achieve the above object, the invention of claim 1 is a pipe fitting in which a first seal ring and a second seal ring are arranged in the axial direction of the seal portion on the inner peripheral surface of a resin fitting body into which a pipe is inserted, in order from the side opposite to the insertion side of the pipe, and a spacer ring is arranged between the first seal ring and the second seal ring in the seal portion so that it can tilt with respect to the first seal ring, and the spacer ring has a trapezoidal cross section, and the short side and long side, which are parallel opposite sides of the trapezoidal cross section, are one located radially inward and the other located radially outward.

The present invention provides a pipe fitting in which the first seal ring is less likely to protrude from the seal portion when the pipe is inserted.

FIG. FIG. 2 is an enlarged view of a main part of FIG. FIG. 13 is an exaggerated view showing the state in which the pipe is inserted at an angle. FIG. FIG. 1 is a vertical cross-sectional view showing an entire conventional pipe joint. FIG. 13 is an exaggerated view showing the state in which the pipe is inserted at an angle.

An embodiment of the pipe joint will now be described.
The pipe fitting 1 shown in Fig. 1 is for connecting synthetic resin pipes 2 through which a fluid flows, and includes a cylindrical synthetic resin fitting body 4. The upstream pipe 2 (right side in Fig. 1) is inserted into the fitting body 4 from one end (right end in Fig. 1) in the axial direction of the fitting body 4. The downstream pipe 2 (left side in Fig. 1) is inserted into the fitting body 4 from the other end (left end in Fig. 2) in the axial direction of the fitting body 4.

In addition, since the upstream and downstream sides of the pipe fitting 1 have the same structure, only the structure on the upstream side will be described below, and the structure on the downstream side will be given the same reference numerals as the upstream side and will not be described.

On the inner circumferential surface of the joint body 4, an annular protrusion 5 is formed in the center of the axial direction of the joint body 4. On the inner circumferential surface of the joint body 4, a housing portion 6 that houses the end of the pipe 2 is provided in a portion near the end of the joint body 4 adjacent to the annular protrusion 5. A cylindrical incore 7 is inserted into the end of the pipe 2. The incore 7 is prevented from sinking into the pipe 2 by a flange 7a formed on the end of the incore 7. The end of the pipe 2 with the incore 7 inserted is inserted from the end of the joint body 4 and housed in the housing portion 6.

A seal section 8 with a larger diameter than the accommodation section 6 is provided on the inner peripheral surface of the fitting body 4 in the portion between the accommodation section 6 and the corresponding end of the fitting body 4. In the seal section 8, a first seal ring 9, a spacer ring 10, a second seal ring 11, and a retaining ring 12 are arranged in the same order from the accommodation section 6 side toward the end of the fitting body 4. The first seal ring 9 and the second seal ring 11 are the same (same material, shape, dimensions, etc.), so there is no trouble in distinguishing them from each other when assembling the pipe fitting 1.

When the end of the pipe 2 is inserted into the housing portion 6 of the fitting body 4, the pipe 2 passes through the first seal ring 9, the spacer ring 10, the second seal ring 11, and the retaining ring 12. At this time, the first seal ring 9 and the second seal ring 11 are in contact with the outer peripheral surface of the pipe 2, and this state prevents the fluid flowing through the fitting body 4 from leaking out of the pipe fitting 1 from between the outer peripheral surface of the pipe 2 and the inner peripheral surface of the fitting body 4.

The pipe fitting 1 includes a retaining member 13 for retaining the pipe 2 on the fitting body 4, and a cap 14 for attaching the retaining member 13 to the fitting body 4. The retaining member 13 is provided with an annular lock ring 17 located between the fitting ring 15 and the split ring 16. The retaining member 13 is located adjacent to the retaining ring 12 arranged in the seal portion 8 of the fitting body 4.

The cap 14 is formed in a cylindrical shape. The end (insertion end) of the joint body 4 is inserted into the open end (end on the joint body 4 side) of the cap 14, thereby sandwiching the retaining member 13 between the joint body 4 (retaining ring 12) and the cap 14.

The cap 14 is attached to the fitting body 4 by snapping its open end to the insertion end of the fitting body 4 at a portion where the open end radially overlaps the insertion end of the fitting body 4. By attaching the cap 14 to the fitting body 4, the retaining member 13 sandwiched between the fitting body 4 and the cap 14 is attached to the fitting body 4.

When the retaining member 13 is attached to the fitting body 4 by the cap 14 and the end of the pipe 2 penetrates the retaining member 13 and the cap 14 and is inserted into the accommodation section 6 from the insertion end of the fitting body 4, the lock ring 17 of the retaining member 13 presses against the outer circumferential surface of the pipe 2, thereby preventing the pipe 2 from slipping out of the fitting body 4.

Next, the spacer ring 10 will be described in detail.
2, the spacer ring 10 has an annular shape and a trapezoidal cross section. The spacer ring 10 is a machined product made from a bar of metal material such as a copper alloy. Therefore, the spacer ring 10 can have a higher degree of circularity and is also more stable in shape than a spacer ring made of, for example, a synthetic resin.

The outer diameter of the spacer ring 10 is set to be slightly smaller than the inner diameter of the seal portion 8. Therefore, the spacer ring 10 can move freely in the seal portion 8, in other words, it is easy to place it in the seal portion 8 when assembling the pipe joint 1.

The spacer ring 10 is subjected to barrel processing after the cutting process. Examples of barrel processing include barrel polishing and barrel plating. The corners of the spacer ring 10 that has been barrel processed are appropriately chamfered. Therefore, when the pipe 2 is inserted, the spacer ring 10 comes into contact with the inner surface of the seal portion 8 and the outer surface of the pipe 2 softly, preventing scratches on the peripheral surface and preventing a decrease in watertightness between the first seal ring 9 and/or the second seal ring 11 due to scratches. In other words, even if the spacer ring 10 is made of a hard metal, it can slide well against the soft pipe 2 and the joint body 4 (seal portion 8) made of synthetic resin.

The trapezoidal cross-sectional shape of the spacer ring 10 is specifically set so that the short side is radially outward and the long side (the side opposite the short side) parallel to the short side is radially inward. Therefore, the first tip surface 10a of the spacer ring 10, which is located on the side facing the first seal ring 9, is a conical surface that is inclined so that it moves away from the first seal ring 9 as it moves radially outward. The angle of inclination is referred to as the "inclination angle X."

Figure 3 shows an exaggerated view of the spacer ring 10 tilted relative to the first seal ring 9. This tilt of the spacer ring 10 is caused by the pipe 2 being inserted obliquely into the pipe fitting 1, causing the spacer ring 10 to receive the insertion force of the pipe 2 unevenly at a portion of its circumference. If the spacer ring 10 is tilted too far relative to the first seal ring 9, that portion of the circumference of the first seal ring 9 is excessively pressed toward the rear side via the corresponding portion of the first tip surface 10a of the spacer ring 10 (pressing force F).

However, as mentioned above, the first tip surface 10a of the spacer ring 10 is inclined in advance with respect to the first seal ring 9. Therefore, even if the inclination of the spacer ring 10 with respect to the first seal ring 9 becomes excessive, the first tip surface 10a can maintain the state of being "inclined so as to move away from the first seal ring 9 as it moves radially outward."

Therefore, the circumferential portion of the first seal ring 9 that is pushed toward the rear side via the first tip surface 10a is also subjected to a pressing force F that acts radially outward, in other words, a force that acts in a direction that causes the first seal ring 9 to remain in the seal portion 8. For this reason, even if the pipe 2 is inserted at an angle, the first seal ring 9 can be prevented from protruding from the seal portion 8.

2, in order to achieve this effect, it is preferable that the inclination angle X of the first tip surface 10a of the spacer ring 10 is not close to 0 degrees. If the inclination angle X of the first tip surface 10a is close to 0 degrees, when the inclination of the spacer ring 10 with respect to the first seal ring 9 becomes excessive, the state of the first tip surface 10a is easily changed from the "inclination so as to move away from the first seal ring 9 as it moves radially outward" to "inclination so as to move closer to the first seal ring 9 as it moves radially outward", and a force acting radially inward is applied to the first seal ring 9, as in the conventional technology (see FIG. 6).

Conversely, if the inclination angle X of the first tip surface 10a is close to 90 degrees, the spacer ring 10 will have a sharp point toward the first seal ring 9, making it easier to damage the first seal ring 9.

Taking all of the above into consideration, as well as the material (e.g., rubber such as EPDM), shape, and dimensions of the first seal ring 9, the inclination angle X of the first tip surface 10a of the spacer ring 10 is preferably 20 degrees to 30 degrees, more preferably 26 degrees to 28 degrees, and in this embodiment is set to 27 degrees.

The second end face 10b of the spacer ring 10, which faces the second seal ring 11, is inclined so that it moves away from the second seal ring 11 as it moves radially outward. The angle of this inclination is referred to as the "inclination angle Y."

The inclination angle Y of the second tip surface 10b is set to be the same as the inclination angle X of the first tip surface 10a. Therefore, the spacer ring 10 has the same shape in the front and rear of the axial direction and has no directionality in its shape, so there is no need to troublesomely distinguish between the first tip surface 10a and the second tip surface 10b when assembling the pipe fitting 1.

This also means that the long side of the trapezoidal cross section of the spacer ring 10 can be set long. If the long side can be set long, the axial play of the first seal ring 9, spacer ring 10, and second seal ring 11 can be reduced even before the pipe 2 is inserted. Therefore, the inclination of the first seal ring 9, spacer ring 10, and second seal ring 11 when the pipe 2 is inserted can be suppressed, and the protrusion of the first seal ring 9 from the seal portion 8 can be more effectively suppressed.

In other words, in the conventional technology shown in FIG. 5, when considering the filling rate of the first seal ring 109 and the second seal ring 111 in the seal portion 108 after the pipe 102 is inserted into the pipe joint 101, setting the spacer ring 110 to be long in the axial direction is not possible because the filling rate would be too high. Therefore, it is necessary to use a spacer ring 110 that is short in the axial direction, and before the pipe 102 is inserted, the first seal ring 109, the spacer ring 110, and the second seal ring 111 have large play in the axial direction.

If the play is large, the inclination of each of the first seal ring 109, the spacer ring 110, and the second seal ring 111 tends to become large when the pipe 102 is inserted. This encourages the first seal ring 109 to protrude from the seal portion 108 when the pipe 102 is inserted.

As shown in FIG. 2, the spacer ring 10 has chamfers 10c and 10d between the first end face 10a and the long side of the trapezoidal cross section, and between the second end face 10b and the long side. The chamfers 10c and 10d are inclined so that they move away from the corresponding first seal ring 9 or second seal ring 11 as they move radially inward.

As a result, when the pipe 2 is inserted, the spacer ring 10 comes into contact with the outer peripheral surface of the pipe 2 more gently, preventing the outer peripheral surface from being scratched. This prevents a decrease in watertightness between the pipe 2 and the first seal ring 9 and/or the second seal ring 11, which would otherwise be caused by scratches.

[Another example]
4, in the seal portion 8, the wall surface 8a of the step located at the boundary with the accommodation portion 6, in other words the wall surface 8a located on the side opposite the spacer ring 10 and facing the first seal ring 9, is inclined so as to move away from the first seal ring 9 as it moves radially outward. In this way, a reaction force toward the radially outward is applied to the first seal ring 9 even when it abuts against the wall surface 8a, and the first seal ring 9 can be more effectively prevented from protruding from the seal portion 8 when the piping 2 is inserted.

○Do not incline the second tip surface 10b of the spacer ring 10. In other words, set the inclination angle Y of the second tip surface 10b to 0 degrees.

○The spacer ring 10 is made of synthetic resin. An example of a synthetic resin suitable for the spacer ring 10 is a mixture of polyphenylene sulfide resin and glass fiber.

The cross-sectional trapezoid shape of the spacer ring 10 is set so that the short side is radially inward and the long side parallel to the short side is radially outward.

○ Pipe fitting 1 is a so-called socket, but this can be changed to a tee or elbow.

○ All of the retaining members 13 of the pipe fitting 1 were of the so-called one-touch type, but some of the retaining members will be changed to non-one-touch types such as screw joints or heat fusion joints.

[Note]
A pipe fitting in which a first seal ring and a second seal ring are arranged in order from the side opposite the insertion side of the pipe in the axial direction of the seal portion in a seal portion formed on the inner surface of a plastic fitting body into which a piping is inserted, and a spacer ring is arranged in the seal portion between the first seal ring and the second seal ring, and a wall surface in the seal portion that faces the first seal ring in the axial direction is inclined so as to move away from the side of the first seal ring as it moves radially outward.

○ A pipe fitting in which a first seal ring and a second seal ring are arranged in order from the side opposite the insertion side of the pipe in the axial direction of the seal portion formed on the inner peripheral surface of a resin fitting body into which a pipe is inserted, and a spacer ring is arranged between the first seal ring and the second seal ring in the seal portion, and the spacer ring has a trapezoidal cross section, and the short side and long side, which are parallel opposite sides of the trapezoidal cross section, are one located radially inward and the other located radially outward.

(A) A pipe fitting in which a first seal ring and a second seal ring are arranged in the axial direction of the seal portion on the inner circumferential surface of a resin fitting body into which a pipe is inserted, in that order from the side opposite the insertion side of the pipe, and a spacer ring is arranged between the first seal ring and the second seal ring in the seal portion so that it can be tilted with respect to the first seal ring, and the tip surface of the spacer ring facing the first seal ring is tilted so as to move away from the first seal ring as it moves radially outward.

(b) A pipe fitting as described in (a) in which the angle of inclination of the tip surface is 20 degrees to 30 degrees.

According to the inventions (a) and (b), the tip surface of the spacer ring that faces the first seal ring is inclined in advance with respect to the first seal ring. Therefore, even when the inclination of the spacer ring with respect to the first seal ring becomes excessive, the tip surface can maintain the state of "inclining so as to move away from the first seal ring as it moves radially outward." Therefore, a force acting radially outward, in other words a force that tries to make it remain in the seal portion, is applied to a circumferential portion of the first seal ring that is pushed toward the back side via the tip surface. Therefore, even if the piping is inserted at an angle, the first seal ring can be prevented from protruding from the seal portion.

REFERENCE SIGNS LIST 1...pipe joint, 2...piping, 4...joint body, 8...seal portion, 9...first seal ring, 10...spacer ring, 10a...first tip surface, 10b...second tip surface, 11...second seal ring.

Claims (1)

a pipe fitting in which a first seal ring and a second seal ring are arranged in order from the side opposite the insertion side of the pipe in the axial direction of the seal portion in a seal portion formed on the inner surface of a plastic fitting body into which a piping is inserted , so that one pipe is sealed with each of the first seal ring and the second seal ring , and a spacer ring that is separate from the inner surface of the fitting body is arranged between the first seal ring and the second seal ring in the seal portion so as to be able to tilt with respect to the first seal ring, wherein the inner surface of the fitting body is provided with a wall surface located on the side facing the first seal ring on the axial opposite side to the spacer ring, and a reaction force directed radially outward is applied to the first seal ring when it comes into contact with the wall surface which receives a force due to the insertion of the piping .

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