JP2524754Y2 - Resin pipe fittings - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a fluid pipe such as a pipe for supplying high-purity liquid or ultrapure water for semiconductor production to fluid equipment such as various valves, filters, pumps, flow meters and tanks. The present invention relates to a resin-made pipe joint used when connecting the pipes.

[0002]

2. Description of the Related Art As a conventional pipe joint of this type, a pipe joint shown in FIG. 4 is known. This pipe joint has a socket A1 of the joint body A into which the one end insertion portion b1 of the pipe material B is inserted.
A seal part a1 formed of an annular surface is formed at the entrance of the tube member B, and an inner ring F having a curved peripheral wall f is press-fitted immediately inside the insertion part b1 of the tube member B, whereby the tube member B
Is locally bulged radially outward along the peripheral wall f to form a bulged portion b.
3 and a male screw part a at one end of the joint body A.
2, the female threaded portion e1 of the push ring E is screwed and screwed to push the bulged portion b3 and the inner ring F of the tube material B toward the joint body A side, and the tube end side of the bulged portion b3. The inclined surface is configured to be pressed against the seal portion a1 to apply a sealing force.

[0003] Therefore, the swelling portion b3 of the tube material B is sandwiched between the sealing portion a1 of the joint body A, the pressing portion e2 of the pressing wheel E, and the peripheral wall f of the inner ring F, so that the tube material B is prevented from coming off. The external leakage of the fluid in the pipe B and the invasion of foreign matter into the pipe B are prevented by the sealing force generated when the pipe end side inclination of the bulging portion b3 is pressed against the seal portion a1.

[0004]

The conventional resin-made pipe joint having the above-mentioned structure is extremely easily softened when the fluid is at a high temperature because the inner ring F is directly exposed to the fluid. For this reason, the stress of the inner ring F is remarkably reduced, and the force of pressing the tube B against the bulging portion b3 is reduced, so that the sealing force is lost and the fluid leaks.

Further, since the inner ring F is press-fitted into the tube B, the smooth movement of the fluid tends to be hindered at the inner ring F. In particular, the outer surface of the peripheral wall f of the inner ring F and the bulging portion A phenomenon occurs in which the fluid stays in a small gap with the inner surface of b3. Therefore, it is unsuitable as a joint for piping for high-purity liquid or ultrapure water, which requires smooth movement, and is restricted in use.

For this reason, the present applicant has already filed Japanese Utility Model Application No.
As disclosed in No. 69378 (Japanese Utility Model Laid-Open No. 2-117494), the one-end insertion portion of the tube material whose diameter has been enlarged by press-fitting the inner ring is inserted into the one-end receptacle of the tubular joint main body. The primary seal portion crossing the axis formed at the back of the receiving port is brought into contact with the inner end seal portion of the inner ring and pressed against the bulge formed on the outer periphery of the outer end portion side of the inner ring. The secondary sealing portion crossing an axis formed at the entrance of the receiving port is brought into contact with an outer peripheral sealing surface which is reduced in diameter toward the pipe end formed on the outer periphery of the insertion portion, and The present invention proposes a pipe joint which applies a sealing force to the primary seal portion and the inner end seal portion and the secondary seal portion and the outer peripheral seal surface by screwing a press ring screwed into an outer thread portion of the joint body. doing.

[0007] According to the above-mentioned resin pipe joint which the present applicant has already proposed, a strong sealing force is generated between the primary seal part of the joint body and the inner end seal part of the inner ring by the screwing of the pressing ring, and since this is a load pressing force in the axial direction is the primary seal formed by the normal temperature at the time of course, be suppressed as much as possible the stress relaxation due to variations in temperature (high temperature), also the movement of the fluid Since the inner ring that does not hinder the insertion is pressed into the insertion portion of the tube material, the cross section of the flow path becomes uniform, and the fluid can be smoothly moved without stagnation. In addition, a strong sealing force is generated between the secondary seal portion of the joint body and the outer peripheral seal surface of the tube, and an axial pressing force is applied to the secondary seal, thereby relieving the stress similarly to the primary seal. Can be suppressed as much as possible. Therefore, such a pipe joint can be suitably used as a pipe joint for high-purity liquid or ultrapure water.

The resin pipe joint proposed by the applicant of the present invention has a structure in which an inner ring is pressed against the joint body side via a pipe at a pressing edge portion at a radially inner end of a pressing piece of a pressing ring. In order to improve the sealing function while facilitating the insertion of the tube material during mounting, the shape and dimensions of the inner diameter part of this pressing ring are obtained. Must be set strictly. That is, the larger the inner diameter of the annular pressing piece in the axial direction over the entire length in the axial direction of the pressing ring is larger than the outer diameter of the tube, the easier it is to insert the pressing ring into the tube. The inner surface of the inner ring cannot be in close contact with the outer surface of the inner ring, and a gap is formed between the tube and the inner ring, causing liquid to accumulate. If is set equal to or smaller than the outer diameter of the tube material, a large resistance acts on the screwing operation of the push ring, and the workability deteriorates, and even if the push ring is forcibly screwed, the primary seal or There was a problem that it was difficult to obtain the surface pressure required for the next seal.

The present invention has been made in view of the above-mentioned circumstances. In addition to suppressing the stress relaxation irrespective of the temperature fluctuation of the fluid, the present invention facilitates the mounting workability by the screwing of the push ring, and at the same time, makes the inner surface of the pipe material inner ring. It is an object of the present invention to provide a resin-made pipe joint which can securely adhere to an outer surface to prevent generation of a liquid pool, ensure excellent sealing performance at a seal portion, and can be easily disassembled. The purpose is.

[0010]

In order to achieve the above object, the resin pipe joint according to the present invention is provided with an inner ring on the inner surface.
A tubular joint body having a socket into which one end insertion portion of the pipe member is inserted into the inner peripheral surface and having a male thread portion on the outer peripheral surface, and the insertion port side of the joint body and the insertion portion of the tube material The resin pipe joint comprises a seal portion formed on the side and abutting against each other, and a press ring screwed into an external male screw portion of the joint body and applying a sealing force to the seal portion by screwing thereof. Formed at the inner diameter of the inner surface side of the annular pressing piece at the front end via the tube when the pressing wheel advances.
The vicinity of the pressing edge that presses the inner ring against the joint body side is made minutely in the axial direction, and the inner diameter of the vicinity is set to be equal to or smaller than the outer diameter of the pipe material , and the pressing edge The inner surface of the pressing piece except for the vicinity of the portion is formed as a tapered surface having an angle of 5 to 15 ° whose diameter gradually increases toward the outer end.

[0011]

According to the present invention, the sealing portion on the receiving side of the joint body and the sealing portion on the insertion side of the pipe material are brought into contact with each other by the screwing of the pressing wheel, and the sealing force applied to both sealing portions Stress relaxation due to temperature fluctuation is suppressed, and excellent sealing properties can be secured.

Further, the pressing edge portion of the pressing wheel and its pressing edge are provided.
The inner ring part pressed by the
In order to prevent early deterioration by the elephant, the vicinity of the pressing edge portion of the pressing wheel is formed to have a minute length in the axial direction.
In addition, the inner diameter of the vicinity thereof is equal to or smaller than the outer diameter of the tube material , and the inner surface of the pressing piece except the vicinity of the pressing edge gradually increases in diameter toward the outer end. Since it is formed on a tapered surface having an angle of 5 to 15 °, there is little resistance when the push ring is inserted into the pipe material and when it is screwed after insertion, and the mounting work of this kind of pipe joint can be easily and easily performed. And while being able to do it smoothly,
As the pressing wheel is screwed, the inner surface of the tube is securely adhered to the outer surface of the inner ring by the vicinity of the pressing edge, so that there is no long-term gap between the tube and the inner ring that causes liquid accumulation. In addition, a sufficient surface pressure is obtained in the seal portion between the pipe member and the joint body, and excellent sealing performance can be secured for a long period of time . In addition, even if an excessive surface pressure is applied to the vicinity of the pressing edge of the pressing wheel, the vicinity is prevented from being plastically deformed, and the pressing wheel can be easily removed when the joint is disassembled.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a half sectional view of a resin pipe joint according to an embodiment of the present invention. In FIG. 1, resin pipe joints are, for example, PFA, PTFE, ETFE, CTFE, ECTF.
It is composed of a joint body 1, an inner ring 2, and a pressing wheel 4 formed of a resin having excellent properties of chemical resistance and heat resistance such as E.

The joint body 1 is cylindrical and has a first primary seal portion 11 which is formed at least in the back of the receiving port 10 at an end thereof and crosses the axis Q. A cross-shaped secondary seal portion 12 is formed on the axis Q. A male screw portion 13 is formed on the outer periphery of the receiving port 10. The inner diameter of the receiving port 10 is formed to be larger than the inner diameter of the body portion 14, and the tapered surface that gradually decreases in diameter from the inner end toward the outside in the axial direction to the inner surface of the body portion 14 is formed by the taper surface. A first primary seal portion 11 is formed. on the other hand,
The secondary seal portion 12 is formed by a tapered surface that gradually expands in diameter from the radially inner surface near the outer end of the receiving port 10 toward the outside in the axial direction and reaches the root of the male screw portion 13. That is, the secondary seal portion 12 is formed at the entrance of the receiving port 10.

The inner ring 2 has a fitting portion 20 having an outer diameter which can be fitted into the socket 10 of the joint body 1 at the inner end thereof, and a pipe material 5 near the connecting portion with the fitting portion 20.
The press-fit portion 21 having a small diameter corresponding to the thickness of the press-fit portion 21 is formed continuously with the fitting portion 20, and has a sleeve shape as a whole. The inner diameter of the inner ring 2 is set to be the same as the inner diameter of the tube 5 and the inner diameter of the body 14 of the joint body 1 so as not to hinder the movement (flow) of the fluid. At the inner end of the inner ring 2, there is formed an inner end seal portion 22 having a tapered surface which abuts on the first primary seal portion 11.

On the other hand, the outer circumference of the outer end of the inner ring 2, that is, the outer circumference of the outer end of the press-fitting portion 21 gradually increases in diameter from the outer end toward the inner end in the axial direction. A tapered outer seal portion 23 intersecting the inner diameter of the outer seal portion 2 is formed, and the diameter of the top portion of the outer end seal portion 23 is at least larger than the outer diameter of the press-fit portion 21 at the connection portion with the fitting portion 20. It is set to be larger than the outer diameter of the fitting portion 20 of the inner ring 2 in the illustrated example. That is, the large-diameter side of the outer end seal portion 23 is a bulged portion 24 having a mountain-shaped cross section formed on the outer peripheral surface on the outer end side of the inner ring 2. The inclination angle of the tapered surface 25 that gradually decreases in diameter from the top of the bulging portion 24 to the inner end side of the inner ring 2 matches the inclination angle of the secondary seal portion 12 of the joint body 1 and When the inner end seal portion 22 abuts against the first primary seal portion 11, the gap between the inner end seal portion 22 and the secondary seal portion 12 is equivalent to the wall thickness of the tube 5.

The inner ring 2 is integrally connected to the tube 5 in a state where the press-fit portion 21 is press-fitted into one end of the tube 5 and its peripheral wall is enlarged. At this time, the enlarged diameter portion of the peripheral wall of the pipe member 5 becomes the insertion portion 50 inserted into the receiving port 10 of the joint body 1. When the insertion portion 50 is inserted into the receiving port 10, the inner end seal portion 22 abuts against the first primary seal portion 11 of the joint body 1 and the outer end seal portion 23 is inserted. The contact portion 50 is in contact with the inner surface of the inclined portion 51. Further, between the secondary seal portion 12 of the joint body 1 and the tapered surface 25 of the inner ring 2, a part of the insertion portion 50 of the tube 5 is held in an inclined state. That is, the outer peripheral surface of the pipe 5 deformed along the tapered surface 25 of the inner ring 2 becomes the outer peripheral seal surface 5a, and the secondary seal portion 12
Abut.

The above-mentioned press ring 4 is provided with a female screw portion 4 screwed to the male screw portion 13 of the joint body 1 on the inner peripheral surface of the cylindrical portion 40.
1 is formed, and an annular pressing piece 42 extending toward the axial center is formed at the outer end. A pressing edge portion 43 is formed at the inner end of the pressing piece 42 on the inner surface side. The position where the pressing edge 43 is formed is set to be more axial than the outer diameter of the portion adjacent to the fitting portion 20 as well as the top of the bulging portion 24 of the press-fitting portion 21.

Then, as shown in FIG. 2, a minute length t (0.5) in the vicinity 44 of the pressing edge 43, that is, in the axial direction.
The inner diameter γ1 is set to be equal to or smaller than the outer diameter γ2 of the tube material 5 at the portion of the pipe material 5. Furthermore, the inner surface of the pressing piece 42 of the pressing wheel 4 has a tapered surface having a constant angle (θ = 5 to 15 °) whose diameter gradually increases toward the outer end except for the vicinity 44 of the pressing edge 43. 45.

In the pressing wheel 4 thus configured, the inner ring 2 is pressed against the joint body 1 via the pipe member 5 (specifically, the joint body 1 and the inner ring 2 are pressed against each other) and the tube member 5 is connected to the joint body 1 side. (Specifically, the joint body 1 and the tube 5 are pressed against each other) to hold the joint body 1, the inner ring 2 and the tube 5 in an integrally joined state, and to apply a sealing force.

In the resin pipe joint having the above structure, first,
When press-fitting the press-fitting portion 21 of the inner ring 2 to the end of the tubing 5, the end portion inner ring 2 of the bulging portion 24 inserted addition unit 50 which is further expanded position corresponding to thereby enlarged as a whole of the pipe member 5 Becomes Then, the inner ring 2 and the one-end insertion portion 50 of the tube 5 into which the press-fit portion 21 is press-fitted into the end portion of the tube 5 are inserted into the receiving port 10 of the joint body 1 and the inner end seal portion 22 is formed. The female threaded part 41 of the press ring 4 which is brought into contact with one primary seal part 11 and then loosely fits in the pipe member 5 in advance is screwed into the male threaded part 13 of the joint body 1, and this is screwed and strongly tightened. The pipe member 5 can be connected to the joint body 1.

By connecting the pipe member 5 in this manner, the insertion portion 50 of the pipe member 5 is sandwiched between the press-fitting portion 21 of the inner ring 2 which cannot be moved in the axial direction and the joint main body 1, and 2 outer end seal portion 23 and pressing wheel 4
Is also locally pinched by the pressing edge portion 43.
Therefore, the tube member 5 is held with a strong retaining force to prevent the tube member 5 from moving.

Further, when the pressing ring 4 is screwed and strongly tightened, the first primary seal portion 11 of the joint body 1 and the inner end seal portion 22 of the inner ring 2 are pressed against each other, and a strong adhesion force is generated therebetween. Also, in the resin pipe joint shown in FIG. 1, at the same time, the secondary seal portion 12 of the joint body 1, the outer peripheral seal surface 5a of the pipe member 5, the outer end seal portion 23 of the inner ring 2, and the second primary seal portion Inclined part 5 of pipe material 5
The inner surfaces 1 are also pressed against each other to generate a strong sealing force therebetween, and the outer and inner surfaces of the tube 5 are sealed on both surfaces. Therefore, in this resin-made pipe joint, a so-called primary seal inside the flow path is formed between the joint body 1 and the inner ring 2 and at two places between the inner ring 2 and the pipe member 5, which is excellent. It is possible to reliably prevent leakage of fluid or intrusion of foreign matter by ensuring sealing performance.

Further, since a so-called secondary seal outside the flow path is formed between the joint body 1 and the pipe member 5, even if a problem occurs in the primary seal due to creep or the like due to a heat cycle, this secondary seal is formed. The secondary seal prevents fluid leakage or foreign matter intrusion, making the seal extremely reliable. In addition, in the case of this resin-made pipe joint, the pressing force in the axial direction is applied to all three seal portions by cooperation of the joint body 1 and the press ring 4, so that not only the fluid at normal temperature but also the fluid Even at high temperatures, seal breakage due to stress relaxation is suppressed as much as possible, and excellent sealing properties can be ensured.

By the way, the inner diameter of the inner ring 2 is set to be the same as the inner diameter of the pipe 5 and the inner diameter of the body 14 of the joint body 1 so as not to hinder the movement of the fluid. Since the cross section of the road becomes uniform and the flow path characteristic of smoothly moving the fluid without stagnation can be secured, it can be suitably used as a joint for a high-purity liquid or ultrapure water pipe.

Furthermore, it is desired that the pressing wheel 4 which is tightened to achieve the primary and secondary seals can be easily inserted into the tube 5 at the time of mounting. However, as shown in FIG. 3, the inner diameter R of the pressing piece 42 of the pressing wheel 4 is determined.
Is larger than the outer diameter dimension γ2 of the pipe member 5, a gap G is formed between the inner surface of the pipe member 5 and the outer end of the inclined portion 51 of the inner ring 2, and a liquid pool may be generated therefrom. Of course, the inner diameter R is equal to the outer diameter γ2 of the tube material 5.
When it is smaller than the above, the resistance at the time of inserting the pressing wheel 4 into the pipe member 5 becomes large, and the workability is deteriorated.

However, in the present invention having the above-described structure, the vicinity of the pressing edge 43 of the pressing wheel 4
4 is set to be equal to or smaller than the outer diameter dimension γ2 of the tube 5, and the tapered surface 45 having an angle of 5 to 15 ° gradually increasing in diameter toward the outer end except for the vicinity 44. Is formed, the resistance is small along the tapered surface 45 when the push ring 4 is inserted into the tube material 5, the insertion is easy and smooth, and the sliding resistance is relatively high even when the push ring 4 after insertion is screwed. The number of tightening operations is relatively small. Moreover, in the tightened state, the inner surface of the tube 5 can be brought into close contact with the outer surface of the inner ring 2 at the vicinity 44 of the pressing edge 43, so that there is no gap that may cause a liquid pool there.

Incidentally, the angle θ of the tapered surface 45 is 5
When the angle is less than 0 °, not only is it very difficult to insert the pushing wheel 4 into the tube 5 and to screw the tube after the insertion, but even if it is forcibly screwed, the inner surface of the tube 5 is When the angle θ of the tapered surface 45 exceeds 15 °, the insertion and screwing of the press wheel 4 is easy and smooth. On the other hand, the surface pressure applied to the peripheral portion 44 of the pressing edge portion 43 is excessive, and the peripheral portion 44 is plastically deformed, which causes a fatal problem that the pressing ring 4 cannot be removed when the resin pipe joint is disassembled. Will be.

[0029]

As described above, according to the present invention, not only can it be suitably used as a joint such as a pipe for ultrapure water, but also the portion near the pressing edge of the pressing wheel can be made minute in the axial direction.
In addition, the inner diameter of the vicinity thereof is equal to or smaller than the outer diameter of the tube material, and the inner surface of the pressing piece except the vicinity of the pressing edge gradually increases in diameter toward the outer end. Due to the synergistic action with the formation of the tapered surface having an angle of up to 15 °, the resistance at the time of inserting the push ring into the pipe material and at the time of screwing after the insertion is reduced, and the mounting work of this kind of pipe joint is impossible. It is easy and smooth, but with the screwing of the push ring, the inner surface of the tube is firmly adhered to the outer surface of the inner ring by the vicinity of the pressing edge, and liquid pools between the tube and the inner ring that results in a gap that causes occur with obtaining eliminate long term, it is possible for a long time ensure excellent sealing performance even provide sufficient surface pressure to the sealing portion between the tube member and the fitting body. In addition, since an excessive surface pressure is not applied to the vicinity of the pressing edge portion of the pressing ring and the vicinity is not plastically deformed, the joint can be easily disassembled by removing the pressing ring.

[Brief description of the drawings]

FIG. 1 is a half sectional view showing a resin pipe joint according to an embodiment of the present invention.

FIG. 2 is a view showing a configuration of a press wheel of the resin pipe joint in the embodiment.

FIG. 3 is an explanatory diagram in the case where the inner diameter of a pressing wheel is too large with respect to the outer diameter of a tube.

FIG. 4 is a half sectional view showing a conventional resin joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Joint main body 2 Inner ring 4 Press ring 5 Tube material 5a Outer peripheral sealing surface 10 Reception port 11 Primary seal part 12 Secondary seal part 22 Inner end seal part 24 Swelling part 42 Pressing piece 43 Pressing edge part 44 Peripheral part of pressing edge part 45 Tapered surface Q axis γ1 inner diameter γ2 outer diameter

Claims (1)

(57) [Scope of request for utility model registration] 1. One end of a tube provided with an inner ring on an inner surface
The insertion portion has a socket inserted into the inner peripheral surface, and has a cylindrical joint body having a male thread portion on the outer peripheral surface, and is formed on the socket side of the joint body and the insertion portion side of the pipe material. A resin pipe joint comprising: a seal portion which is in contact with each other, and a pressing ring which is screwed into an outer peripheral thread portion of the joint main body to apply a sealing force to the seal portion by its screwing;
The inner ring is formed at a radially inner end of an annular pressing piece of the pressing ring through the tube when the pressing ring is screwed.
Axis vicinity of the pressing edge portion for pressing the grayed to the fitting body side
Direction, and set the inner diameter of the vicinity to be equal to or smaller than the outer diameter of the tube ,
And resin pipe fitting, characterized by forming a tapered surface having a 5-15 angle ° progressively become large diameter inner surface toward the outer end of the pressing piece except for the vicinity of the pressing edge portion.