JP2523405Y2 - Pipe fittings - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application field] The present invention relates to a pipe joint provided with a retaining ring for retaining a pipe.

[Conventional technology]

As a conventional pipe joint, for example, as shown in FIG. 6, a restricting portion a formed by a tapered surface that gradually decreases inward in the axial direction is formed on the inner periphery of the end of a cylindrical joint body A, An annular elastic seal member B made of rubber is pressed inward in the axial direction via a retainer E by a pressing ring D screwed to an end of the joint body A, so as to be pressed against the regulating portion a, and The outer periphery of the pipe C inserted into the joint body A through the pressing ring D is also pressed against the outer periphery of the pipe C to secure the sealing property between the joint body A and the pipe C. And an annular space X formed by the outer circumference of the pipe C and the inner circumference of the pressing ring D.
In addition, a retaining ring F in which a plurality of biting teeth f1 to f4 to be inserted into the outer surface of the pipe C are formed in an axially tandem and provided with a cut-out portion (not shown) allowing diameter expansion and diameter reduction. There is known a structure in which the pipe C is prevented from falling off by the retaining ring F.

In such a pipe joint, the amount of protrusion (protrusion width) of the retaining teeth F into the radially inward direction of the biting teeth f1 to f4 of the retaining ring F in a state where the axis of the joint main body A and the axis of the retaining ring F coincide with each other. Is the same for all the teeth f1 to f4. In addition, the press ring D has a first cylindrical surface d1 disposed concentrically with the joint body A on the inner periphery thereof, and the first cylindrical surface d1 is provided with the retaining ring F. The second cylindrical surface f5 provided on the outer periphery is slidably overlapped in the axial direction.

In the appropriate initial state of connecting pipe C to this fitting,
As shown in FIG. 6, the first pressing ring D connected to the joint body A
The second cylindrical surface f5 of the retaining ring F is slidably overlapped in the axial direction on the cylindrical surface d1, and furthermore, the first cylindrical surface d1 is pushed inward in the radial direction to reduce the diameter. Stop ring F
All the biting teeth f1 to f4 bit into the pipe C at a uniform depth. Therefore, when the pipe C moves inward or outward in the axial direction with respect to the joint body A at the time of an earthquake or the like,
The above-mentioned retaining ring F into which the hard teeth f1 to f4 of the tube C bite moves together with the tube C in the same direction as the tube C, so that the movement of the tube C is absorbed. Then, the retaining ring F moves axially outward together with the pipe C, and the tapered surface fa formed at the end of the retaining ring F is pressed against the pressing ring D.
When the pipe C hits the tapered surface d formed on the inner periphery of the pipe C, the pipe C is prevented from dropping at that position.

When the pipe joint described with reference to FIG. 6 normally exerts the original function given to it, the above-described appropriate pipe movement absorbing action and pipe drop-out preventing action are obtained.

However, in order for the pipe joint described with reference to FIG. 6 to normally exhibit its original function, the fitting ring A is screwed into the fitting body A and the retaining ring F is housed inside the fitting ring D while reducing the diameter. And thereby the first cylindrical surface of the joint body A
It is necessary to make the second cylindrical surface f5 of the retaining ring F overlap with d1. In addition, in order to accommodate the retaining ring F inside the pressing ring D, the retaining ring F must be removed while reducing its diameter. All bite teeth f1 ~ of the retaining ring F
Since it is necessary to insert f4 into the pipe C, a large torque is required as a tightening torque when the pressing ring D is screwed into the joint body A.

However, the amount of the biting teeth f1 to f4 necessary for normally exerting the original function of the pipe joint with respect to the pipe C is predetermined to a predetermined size.
The magnitude of the above-described tightening torque is set to a predetermined magnitude in advance based on the amount of biting of the biting teeth f1 to f4 into the pipe C.

On the other hand, the outer diameter of the tube C and the first cylindrical surface d2 of the pressing ring D
Since there is a manufacturing dimensional error within a tolerance range with respect to the inner diameter of the inner ring and the outer diameter of the retaining ring F, depending on the combination of the tube C, the pressing ring D and the retaining ring F, the above-mentioned biting tooth f1 may be used. The penetration amount of f4 to the pipe C is not always the predetermined degree. For example, the distance between the second cylindrical surface f5 of the retaining ring F and the tip of the biting teeth f1 to f4 (for the size of the mutual interval H between the pipe C and the first cylindrical surface d1 of the pressing ring D) ( It is possible that H1 is too large or too small (corresponding to the thickness of the retaining ring), and under such circumstances, the press ring D is screwed into the joint body A and the press ring D When the retaining ring F is accommodated in the inside, the amount of penetration of the dent teeth f1 to f4 into the tube C may be insufficient or excessive for the above-mentioned predetermined size.

[Problems to be solved by the invention]

However, as is apparent from the above description, in the conventional pipe joint, when the press ring D is screwed to the joint main body A and coupled, the tightening torque applied to the press ring D is as follows.
Since the plurality of biting teeth f1 to f4 of the retaining ring F are used to make the pipe C difficult to insert into the pipe C, the above-mentioned mutual spacing H and the size of the spacing H1 are in an appropriate relationship. Even so, a large torque is required as a predetermined tightening torque when the pressing wheel D is screwed into the joint body A. Even more, the above-mentioned interval H1 is too large for the size of the mutual interval H described above. Occasionally, simply tightening the pressing wheel D with a predetermined tightening torque may not be able to secure an appropriate amount of tightening of the pressing wheel D. If the amount of tightening of the pressing wheel D is insufficient, the gap G shown in FIG. 7 is generated between the retainer E and the pressing wheel D, and the sealing surface pressure of the elastic sheet member B is reduced, and the sealing performance is reduced. Will decrease.

The present invention has been made in view of such circumstances.
That is, the present invention provides a pipe joint having a function of exhibiting the pipe movement absorbing action and the pipe retaining action as described above, wherein the outer diameter of the pipe and the inner diameter of the first cylindrical surface of the pressing ring are described. Furthermore, when there is a manufacturing dimensional error within the tolerance range with respect to the outer diameter of the retaining ring, no matter how the three members of the tube, the press ring, and the retaining ring are combined, the fastening when screwing into the joint body is performed. It is an object of the present invention to provide a pipe joint which can secure an appropriate amount of tightening of a press wheel simply by tightening the press wheel with a torque which is previously set to a predetermined magnitude as an applied torque.

[Means for solving the problem]

In order to achieve the above object, the present invention has a female thread at an end inner circumference, and a taper that gradually decreases in diameter inward in the axial direction on an inner circumference axially inward from the female thread. A cylindrical joint body having a restricting portion formed by a surface, a cylindrical push ring having a male screw portion capable of being screwed to the female screw portion of the joint body, and by screwing the male screw portion and the female screw portion together An elastic member disposed in a first annular space formed between a pipe inserted into the joint body through the pressing ring connected to the joint body and the regulating portion radially opposed to the pipe in the joint body. A second annular space formed between the seal member and the elastic seal member and the pressing ring that is opposed to the elastic sealing member in the axial direction of the joint body and is directed inward in the axial direction by the pressing ring. The above elasticity A retainer that presses the screw member inward in the axial direction of the joint body, and a pull-out that is disposed in a third annular space formed between the pipe and the pressing ring that radially opposes the pipe. A retaining ring, wherein the pressing ring is formed on an inner periphery of the first cylindrical surface concentrically disposed with the joint body, and is formed adjacent to the first cylindrical surface on an axially outward side. And a first tapered surface that is gradually reduced in diameter in an axially outward direction, and the retaining ring is formed in an annular shape with a cut-out portion allowing diameter expansion and diameter reduction. A second cylindrical surface that slidably overlaps the first cylindrical surface of the pressing ring, and that is formed adjacent to the second cylindrical surface on the outer side in the axial direction so as to face outward in the axial direction. A second tapered surface which is gradually reduced in diameter and which is opposed to the first tapered surface of the pressing wheel in the axial direction of the pressing wheel; A plurality of serrations are formed in the axial column, which can be inserted into the tube, and one of these teeth protrudes more radially inward than the other. It is.

[Action]

When connecting a pipe to such a pipe joint of the present invention, for example, an elastic seal member, a retainer and a retaining ring are inserted in this order inside the joint body, and a male screw of a press ring is inserted into the female screw portion of the joint body. The push ring is loosely connected to the joint body by screwing the parts, and the pipe is inserted into the joint body through the push ring, the retaining ring, the retainer, and the elastic seal member. Thereafter, the pressing wheel is tightened with the above-described predetermined tightening torque.

With this configuration, the retaining ring is reduced in diameter and accommodated inside the pressing ring as the pressing ring is tightened, whereby the second cylindrical surface of the retaining ring slides on the first cylindrical surface of the pressing ring. Overlap freely. The tightening torque applied to the push ring at this time is used to make the retaining ring biting teeth into the tube, but only one specific biting tooth must be inserted into the tube. However, since there is no need to make other biting teeth jammed in the tube, the tightening torque required to secure an appropriate amount of tightening of the pressing wheel does not become so large.

Such an effect is obtained by appropriately determining the difference between the protrusion amount of one specific biting tooth of the retaining ring and the protrusion amount of another biting tooth, and there is a manufacturing dimensional error within a tolerance range. It can be exerted in any combination of the three members of the tube, the pressing wheel and the retaining ring.

It should be noted that, given the size of the mutual interval between the pipe and the first cylindrical surface of the pressing ring (see reference numeral H in FIG. 6), the distance between the second cylindrical surface of the retaining ring and the tip of the other biting tooth is large. Interval (H1 in FIG. 6)
It is conceivable that when one of the above-mentioned specific biting teeth is large, the other biting tooth may enter into the tube together with the one specific biting tooth. However, even in this case, the difference between the above-mentioned protrusion amounts is appropriately determined. By doing so, it is possible to reduce the amount of penetration of the other biting teeth as compared with the conventional case, and even in such a case, since one specific biting tooth is inserted into the tube, the bonding strength between the tube and the retaining ring is reduced. Is not impaired.

Also, in this pipe joint, the pipe movement absorbing action is such that one specific biting tooth of the retaining ring bites into the pipe,
In addition, this is exhibited because the first cylindrical surface of the pressing ring and the second cylindrical surface of the retaining ring housed in the pressing ring are slidable. In addition, the pipe retaining action is achieved by the second retaining ring, in which one specific biting tooth is embedded in the pipe.
This is exerted when the tapered surface hits the first tapered surface of the press wheel.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a half sectional view showing an embodiment of the present invention.
In the figure, a tubular joint body 1 is formed in a tubular shape from metal or hard resin, and a female screw portion 1A is formed on an inner periphery of both axial ends (only one end is shown in the drawing).
A restricting portion 1B formed by a tapered surface whose diameter gradually decreases inward in the axial direction is formed on the inner periphery of the female screw portion 1A on the inner side in the axial direction.

The cylindrical pressing wheel 2 is formed in a cylindrical shape from metal or hard resin, and is provided with a male screw portion 2A that can be screwed to the female screw portion 1A on the outer periphery of an inner end in the axial direction. The female threaded portion 1 </ b> A is screwed to the joint body 1. The press wheel 2 has the joint body 1 on its inner periphery.
A first cylindrical surface 2B concentrically arranged with the first cylindrical surface 2B, and a first taper formed adjacent to the first cylindrical surface 2B on the outer side in the axial direction and gradually reducing its diameter toward the outer side in the axial direction Surface 2C.

Thus, a first annular portion formed between the pipe 3 inserted into the joint body 1 through the pressing ring 2 coupled to the joint body 1 and the regulating portion 1B radially opposed to the pipe 3 in the joint body 1 An annular elastic seal member 5 is disposed in the space 4 (in FIG. 1, the annular space 4 is an elastic seal member 5).
It is buried in. The elastic seal member 5 is made of, for example, hard rubber, and a tapered surface 5A formed on the outer periphery and gradually decreasing in diameter in the axial direction abuts the restricting portion 1B of the joint body 1, and the inner peripheral surface 5B is 3 is pressed.

The retainer 6 is interposed in a second annular space 4A formed between the elastic seal member 5 and the pressing ring 2 which is opposed to the elastic seal member 5 in the axial direction of the joint body 1. The retainer 6 presses the elastic seal member 5 inward in the axial direction of the joint body 1 by being pressed inward in the axial direction by the pressing wheel. The retainer 6 has a configuration in which a core 6A made of a steel plate for reinforcement is enclosed inside.

A retaining ring 7 is formed in a third annular space 8 formed between the tube 3 and the pressing ring 2 which is radially opposed to the tube 3.
Are located in The retaining ring 7 is made of metal or hard resin. As shown in FIGS. 2A and 2B, the retaining ring 7 is formed in an annular shape having a cut-out portion 7A that allows the diameter to be increased and reduced. A second cylindrical surface 7C slidably overlapping the cylindrical surface 2B, and a second cylindrical surface 7C on the axially outer side;
And has a second tapered surface 7B which gradually decreases in diameter in the axial direction outward and faces the first tapered surface 2C of the pressing ring 2 in the axial direction of the pressing ring 2. A plurality of saw-toothed cutting teeth 7a to 7d that can be easily inserted into the tube 3 are formed in the inner periphery in the axial direction with the tooth tips directed radially inward. Of these biting teeth 7a to 7d, one specific biting tooth 7a provided at the outer end protrudes more radially inward than the other biting teeth 7b, 7c, 7d. Therefore, the radially inwardly protruding amount h1 of the specific biting tooth 7a is larger than the radially inwardly protruding amount h2 of each of the other biting teeth 7b, 7c, 7d. And
The protrusion amount h1 of the specific undercut 7a and the other undercuts 7b, 7
The protrusion amount h2 of c and 7d is such that when the second cylindrical surface 7C of the retaining ring 7 overlaps with the first cylindrical surface 2B of the pressing ring 2, only the biting teeth 7a are easily inserted into the tube 3. Stipulated. That is, since the above-described three members of the tube 3, the press wheel 2, and the retaining ring 7 have a manufacturing dimensional error within a tolerance range, depending on a combination of the three members, the third member may be used.
Although the radial space of the annular space 8 is widened or narrowed, the retaining ring 7 is provided on the first cylindrical surface 2B of the pressing ring 2 regardless of whether the third annular space 8 is wide or narrow in the radial direction.
When the second cylindrical surface 7C is overlapped, only the specific biting tooth 7a is stuck in the tube 3, and the other biting tooth
7b, 7c, 7d are the projecting amounts of them so as not to get into the tube 3
h1 and h2 are defined.

In the figure, reference numeral 9 denotes a stiffener fitted to the end of the tube 3.

An example of an operation procedure when connecting the pipe 3 to the pipe joint as described above will be described. The elastic seal member 5, the retainer 6, and the retaining ring 7 are inserted into the joint body 1 in this order, and the male screw 2A of the press ring 2 is screwed into the female screw section 1A of the joint body 1, and the press ring 2 is attached. It is loosely connected to the joint body 1. In this state, the pipe 3 is inserted into the joint main body 1 through the pressing wheel 2, the retaining ring 7, the retainer 6, and the elastic seal member 4. Thereafter, the pressing wheel 2 is tightened with the above-described predetermined tightening torque, and an appropriate amount of tightening of the pressing wheel 2 is secured.

In this manner, the retaining ring 7 is accommodated in the inside of the pressing ring 2 with a reduced diameter as the pressing ring 2 is tightened, and the retaining ring 7 is inserted into the third annular space 8 as shown in FIG. In addition, only a specific biting tooth 7a is inserted into the tube 3 and the second cylindrical surface 7C of the retaining ring 7 is slidably overlapped with the first cylindrical surface 2B of the pressing ring 2. And
The tightening torque applied to the push ring 2 when the retaining ring 7 is accommodated in the inside of the press ring 2 with a reduced diameter is only required to allow only one specific biting tooth 7a of the retaining ring 7 to fit into the tube. The other biting teeth 7b, 7c, 7d are
Since it is not difficult, the tightening torque required to secure an appropriate amount of tightening of the pressing wheel can be small.

Therefore, just by tightening the press wheel 2 with the above-mentioned predetermined tightening torque, the press wheel 2 is tightened to an appropriate position, and an appropriate tightening amount is secured. Therefore, the pressing ring 2 presses the elastic seal member 5 inward in the axial direction via the retainer 6, so that the tapered surface of the elastic seal member 5 as shown in FIG.
5A is pressed against the regulating part 1B of the joint body 1 and its inner surface
5B is pressed against the pipe 3, the sealing property between the joint body 1 and the pipe 3 is ensured, and leakage of gas flowing in the pipe 3 and intrusion of water and foreign matter into the pipe 3 are prevented.

In the case where the pipe 3 and the pipe joint are connected as shown in FIG. 1, when a force in a direction of separating or pushing is applied to the pipe 3 and the pipe joint due to an earthquake or the like, the above-described specific The biting teeth 7a are stuck in the tube 3 and the tube 3
The first cylindrical surface 2B of the press ring 2 and the second cylindrical surface 7C of the retaining ring 7 slide in the axial direction, and such a force in the separating direction or the pressing direction is applied to the sliding surface. Absorbed by movement.

When the pulling force in the direction shown by the arrow in FIG. 1 acts on the pipe 3 and the pipe 3 moves in the pulling direction, the specific biting teeth 7a described above are inserted into the pipe 3 and connected to the pipe 3. The second tapered surface 7B of the retaining ring 7
The tube 3 is prevented from coming off by contacting the first tapered surface 2C. The second tapered surface 7B of the retaining ring 7 is the first tapered surface of the pressing wheel 2.
When the tube 3 further moves in the drawing direction after hitting 2C, as shown in FIG. 4, the retaining ring 7 is reduced in diameter by the cooperation of the first tapered surface 2C and the second tapered surface 7B. In addition, the specific biting teeth 7a are deeper into the tube 3, and the other biting teeth 7b, 7c, 7d are also inserted into the tube 3. Therefore, the tube 3 is more firmly connected to the retaining ring 7, and the tube 3 is securely retained. In this case, since the retainer 6 and the elastic seal member 5 do not move, the sealing performance of the elastic seal member 5 does not decrease.

It should be noted that a polyethylene pipe can be used as the pipe 3, but the present invention is not limited to this, and as a matter of course, as shown in FIG. 5, the present invention can also be applied to a corrosion-resistant steel pipe 3 'having a resin coating layer on the outer peripheral surface.

In the above embodiment, the case where only one specific biting tooth 7a fits into the pipe 3 when the retaining ring 7 is accommodated inside the pressing ring 2 with a reduced diameter accompanying the tightening of the pressing ring 2 will be described. did. However, the second cylindrical surface f5 of the retaining ring 7 and the other biting teeth are provided for the mutual spacing between the tube 3 and the first cylindrical surface 2B of the pressing ring 2 (see reference numeral H in FIG. 6). Spacing between the tips of 7b, 7c, and 7d (see reference numeral H1 in FIG. 6)
Is large, it is conceivable that, together with one specific biting tooth 7a described above, other biting teeth 7b, 7c, 7d may enter into the tube. Even in this case,
If the difference in the amount of protrusion between the specific biting tooth 7a and the other biting teeth 7b, 7c, 7d is determined appropriately, the other biting teeth 7b, 7c, 7d
Since it is possible to reduce the amount of penetration of the pressing wheel 2 in order to secure an appropriate amount of tightening, the tightening torque required for securing the appropriate amount of tightening of the pressing wheel 2 does not become too large. Even in such a case, the strength of the connection between the tube 3 and the retaining ring 7 is not impaired because one specific biting tooth 7a is stuck into the tube 3.

[Effect of the invention]

Since the present invention is configured as described above,
The following effects are obtained.

That is, in a pipe joint having a function of exhibiting the above-mentioned pipe movement absorbing action and pipe retaining action, the outer diameter of the pipe, the inner diameter of the first cylindrical surface of the pressing ring, and the outer circumference of the retaining ring If there is a manufacturing dimensional error within the tolerance range with respect to the diameter, no matter how the tube, the press ring, and the retaining ring are combined, a predetermined tightening torque for screwing into the joint body is required. Only by tightening the pressing wheel with the torque determined by the size, it becomes possible to secure an appropriate tightening amount of the pressing wheel.

[Brief description of the drawings]

FIG. 1 is a half sectional view showing an embodiment of the present invention, FIG. 2A is a front view of a retaining ring, and FIG. 2B is IIB- in FIG. 2A.
Sectional view along IIB line, FIG. 3 is an enlarged sectional view of a main part, FIG.
FIG. 5 is an explanatory sectional view when a pulling force is applied to the pipe, FIG. 5 is a half-sectional view showing an embodiment in which the present invention is applied to an external corrosion protection coated steel pipe, and FIG. FIG. 7 is a half sectional vertical sectional view of a provided pipe joint, and FIG. 1 Joint body 1A Female thread 1B Restrictor 2 Press ring 2A Male thread 2B First cylindrical surface 2C First tapered surface 3 Tube 4 First annular space 4A: second annular space 5: elastic seal member 6: retainer 7: retaining ring 7A: missing circle 7B: second tapered surface 7C: second cylindrical surface 7a: specific engagement Teeth 7b, 7c, 7d ... other biting teeth 8 ... third annular space

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Yoshiaki Minami, 153-1, Tajimecho, Kishiwada, Osaka Japan Inside of Nippon Steel Pipe Fitting Co., Ltd. (72) Shozaburo Noda 1, 153, Tajimecho, Kishiwada, Osaka (56) References JP-A-3-265789 (JP, A) JP-A-3-265791 (JP, A) JP-A-59-7895 (JP, U)

Claims (1)

(57) [Scope of request for utility model registration] An end portion has an internal thread at an inner periphery thereof, and a regulation portion formed by a tapered surface gradually decreasing inward in the axial direction at an inner periphery in an axially inner side of the female thread portion. A cylindrical joint main body, a cylindrical push ring having a male screw portion capable of being screwed to the female screw portion of the joint main body, and coupled to the joint main body by screwing the male screw portion and the female screw portion together An elastic seal member disposed in a first annular space formed between the pipe inserted into the joint body through the pressing ring and the restricting portion radially opposed to the pipe in the joint body; By being interposed in the second annular space formed between the member and the pressing ring opposed to the elastic sealing member in the axial direction of the joint body and being pressed inward in the axial direction by the pressing ring, The elastic seal member is A retainer for pressing inward in the axial direction, and a retaining ring disposed in a third annular space formed between the tube and the pressing ring radially opposed to the tube, The pressing ring is formed on its inner periphery with a first cylindrical surface concentrically arranged with the joint body, and formed on the outer side in the axial direction adjacent to the first cylindrical surface and formed on the outer side in the axial direction. A first tapered surface that gradually decreases in diameter toward the first ring, and the retaining ring is formed in an annular shape with a cut-out portion that allows diameter expansion and diameter reduction. A second cylindrical surface slidably overlapping the cylindrical surface, an axially outer side formed adjacent to the second cylindrical surface, gradually reducing its diameter in the axially outward direction, and A second tapered surface that faces the first tapered surface in the axial direction of the pressing wheel,
On its inner circumference, a plurality of serrations, which can be inserted into the tube, are formed in an axial cascade, one of these teeth being more radial than the other. A pipe fitting characterized by protruding inward.