JPH09105487A - Pipe coupling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate a connection work by a method wherein a backup material is located between the bottom of a second annular groove retaining ring and in this way, a second cylinder body is smoothly pushed in a first cylinder body without special operation. SOLUTION: When a retaining ring 3 reaches a position, where it coincides with a first annular groove 11, through push-in movement of a second cylinder body 2, the retaining ring 3 is restored to its initial shape through the elastic return force of itself and an elastic ring 4a and fitted in the first annular groove 11. Thereafter, by slightly pulling back the second cylinder body 2, the retaining ring 3 is moved to the rigid ring 5a side and the side wall of an annular groove part on the rigid ring 5a side and the outer side wall of the first annular groove 11 are engaged with each other through the retaining ring 3. This constitution, since the first and second cylinder bodies 1 and 2 are interconnected in a slip protection state, simplifies connection operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint.

[0002]

2. Description of the Related Art A conventional pipe joint is shown in FIG. This pipe joint is composed of a first tubular body (1) and a second tubular body (2) inserted therein, and a second annular groove circumferentially provided on the outer peripheral surface of one of the second tubular bodies (2). A metal C-shaped retaining ring (3) having a diameter larger than the inner diameter of the other first cylindrical body (1) is externally fitted and held on (21). The second annular groove (21) is the retaining ring.
The depth (3) is set to be smaller than the inner diameter of the first cylindrical body (1) and can be reduced.

In order to bring this pipe joint into a connected state, one of the second cylindrical bodies (2) is pushed into the other of the first cylindrical bodies (1). At this time, the retaining ring (3) has its diameter reduced by the guiding action of the insertion opening of the first tubular body (1) and is pushed inward. When the first annular groove (11) and the second annular groove (21) provided on the inner peripheral surface of the first tubular body (1) coincide with each other, the retaining ring (3) itself The elastic return force returns to the size before reduction and is fitted into the first annular groove (11).
As a result, the first and second cylindrical bodies (1) and (2) are axially engaged with each other via the retaining ring (3) and are connected in a retaining state.

In this structure, the first and second cylindrical bodies (1) (2)
Since they are connected to each other only by the retaining ring (3), the structure for this connection is simple.

[0005]

However, in the prior art, the depth of the second annular groove (21) is set as described above, and the diameter of the bottom surface of the second annular groove (21) is Since it is smaller than the inner diameter of the retaining ring (3) in the free state, a gap is formed between the bottom surface and the retaining ring (3). Therefore, depending on the posture of the second cylindrical body (2), the retaining ring (3) is eccentric with respect to this and the retaining ring from the second annular groove (21).
(3) is in a state where it protrudes greatly to one side. In this state, when the second cylinder (2) is pushed in, the snap ring
(3) is easily caught in the insertion opening. Therefore, when the pushing-in is performed while holding the retaining ring (3) with respect to the second cylindrical body (2) by a jig or the like so as not to decenter the second cylindrical body (2), the first and second cylindrical bodies (1) ( The connection in 2) could not be made smoothly.

According to the invention of claim 1, the "first cylinder (1) and the second cylinder (2) inserted therein, one of the second cylinder
The second annular groove (21) provided around the outer peripheral surface of (2) is provided with a retaining ring (3) which is larger in diameter than the inner diameter of the other first tubular body (1) and is elastically deformable in the radial direction. A first annular ring, which is contractably fitted and held, and which is provided around the inner peripheral surface of the first tubular body (1) by pushing the second tubular body (2) into the first tubular body (1). By fitting the retaining ring (3) in the groove (11), the first and second cylindrical bodies
(1) (2) Pipe joints that are connected to each other ", so that the second cylinder (2) can be smoothly pushed into the first cylinder (1) without any special operation, The task is to facilitate these connection work.

[0007]

According to a first aspect of the present invention, there is provided "a bottom surface of the second annular groove (21) and the retaining ring".
A backup material (4) made of an elastic material is interposed between (3) and ”. In this structure, the backup material (4) is interposed between the retaining ring (3) fitted and held in the second annular groove (21) and the bottom surface of the second annular groove (21). Therefore, regardless of the posture of the second cylindrical body (2),
The retaining ring (3) is maintained substantially concentric with the second cylindrical body (2). Therefore, when the second cylinder (2) is pushed into the first cylinder (1), the retaining ring (3) is moved to the first cylinder.
It will not be excessively caught partially in the insertion opening of (1). Further, since the backup material (4) is made of an elastic material, the diameter of the retaining ring (3) can be reduced. Therefore, in the initial stage of the connecting operation of the first and second cylindrical bodies (1) and (2), the diameter of the retaining ring (3) is smoothly reduced by the guiding action of the insertion opening portion, and the first cylindrical body ( 1) It is pushed in.

When the second cylinder (2) is pushed to the final position, the retaining ring is pushed in the same manner as the conventional one.
(3) is fitted into both the first and second annular grooves (11) and (21), and the first and second cylindrical bodies (1) and (2) are connected to each other in a retaining state. Here, as the backup material (4), as in the invention of claim 2, "an elastic ring (4a) provided over the entire area of the second annular groove (21) in the circumferential direction" is also used. Good. Further, it may be provided at predetermined intervals in the circumferential direction.

According to the third aspect of the present invention, "the elastic ring (4a) has a rigidity ring (4) having a rigidity higher than that of the elastic ring (4a) forward of the second cylinder (2) in the pushing direction. 5a) are connected and integrated, and these elastic ring (4a) and rigid ring (5a)
a) is closely fitted in the second annular groove (21), and is inserted into the annular groove portion (45) provided over the boundary between the elastic ring (4a) and the rigid ring (5a). The retaining ring (3) may be fitted on the outer surface.

When the second cylinder (2) is pushed into the first cylinder (1), the retaining ring (3) is moved to the second cylinder by the insertion opening of the first cylinder (1). It is pushed backward in the pushing direction of the cylinder (2). As a result, the retaining ring (3) is wholly located on the side of the elastic ring (4a), and can be contracted. After that, the retaining ring (3) is reduced by the guiding action of the insertion port, and the first cylinder (1)
It is inserted into the first annular groove (11) in the same manner as the operation of the first aspect of the invention.

Thereafter, when the second tubular body (2) is slightly pulled back, the retaining ring (3) moves to the rigid ring (5a) side, and the annular groove (45) on the rigid ring (5a) side. ) Face the side wall. In this state, the rigid ring (5a) is
It is in a state of being engaged with the first cylindrical body (1) through (3). As a result, the first and second cylindrical bodies (1) and (2) are connected to each other in a retaining state.

In this connected state, even if a repulsive force acts on the first and second cylindrical bodies (1) and (2) and a force in the contracting direction acts on the retaining ring (3), the retaining ring (3 ) Is the elastic ring (4a) and the rigid ring (5a) having a higher rigidity than this
Since the outer ring is fitted over the outer ring, the retaining ring (3) is less likely to be contracted as compared with the outer ring fitted only on the elastic ring (4a).

Further, according to the invention of claim 4, "the elastic ring (4a) is made of rubber, and the elastic ring (4a) is
A seal portion (41) is provided which extends outwardly between the annular side wall of the second annular groove (21) and the retaining ring (3) and is larger than the inner diameter of the first tubular body (1). " It may be one. In this case, when the second tubular body (2) is inserted into the first tubular body (1), the seal portion (41) protruding from the second annular groove (21) has the first tubular body (1). Since it is pressed against the inner peripheral surface of the body (1), the seal portion (41) ensures airtightness between the first and second cylindrical bodies (1) and (2).

[0014]

As described above, according to the first aspect of the invention, the second cylindrical body is used to connect the first and second cylindrical bodies (1) and (2).
When pushing (2) into the first cylinder (1), the snap ring (3) smoothly guides the diameter of the insertion hole of the first cylinder (1) without any special operation. Since the size is reduced, the connecting operation of the first and second cylindrical bodies (1) and (2) is easy. Further, when the retaining ring (3) is fitted into the first annular groove (11), the retaining ring (3) has an elastic restoring force of the backup material (4) in addition to the elastic restoring force of itself. Since it works, the fitting operation of the retaining ring (3) into the first annular groove (11) becomes more reliable.

Further, when the retaining ring (3) is C-shaped with a part of the circumferential direction opened, when reducing the diameter of this retaining ring (3), the symmetrical part of the opening with respect to its center is It tends to bend ahead of the part, but with this one,
Since the tendency is alleviated by the elastic force of the backup material (4), the retaining ring (3) is bent evenly in the circumferential direction. Therefore, also in this point, the snap ring of the retaining ring (3) with respect to the insertion opening of the first tubular body (1) is small, and the second tubular body (2) can be pushed in more smoothly.

In the invention of claim 3, the first and second cylindrical bodies
(1) (2) In the state where they are connected to each other, the retaining ring (3)
Is difficult to shrink, the first and second cylinders (1) (2)
Mutual retaining strength increases. In the invention of claim 4,
The seal portion (41) provided on the elastic ring (4a) ensures the airtightness between the first and second cylindrical bodies (1) and (2), and therefore means for ensuring the airtightness. Need not be provided separately, and the structure of this pipe joint is simplified.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings. As shown in FIG. 1, this embodiment is carried out in a pipe joint for gas piping in which the second cylinder (2) is on the upstream side and the first cylinder (1) is on the downstream side. [Regarding Configuration of Each Part] One first cylinder (1) is a cylinder for connecting the second cylinder (2) to the upstream side of the first connection part (12) provided with a female screw part. The part (13) is continuous. The other second tubular body (2) has an insertion tubular portion (23) to be inserted into the tubular portion (13) on the downstream side of the second connecting portion (22) having a female screw portion. It has a continuous structure.

The outer diameter of the insertion tube portion (23) is equal to that of the cylindrical portion.
It is set to a fitting intersection of a very slight clearance fitting with respect to the inner diameter of (13), and the outer peripheral surface of the base end portion of this insertion tubular portion (23) is
As shown in FIGS. 1 and 2, a second annular groove (21) having a rectangular cross section.
Are installed around. In the second annular groove (21), an elastic ring (4a) made of rubber having a square cross section and a square cross section integrally connected to the front of the insertion tubular portion (23) in the insertion direction are integrated. A ring body (5) including a metal rigid ring (5a) is closely fitted. The outer peripheral surface of the ring body (5) and the outer peripheral surface of the inserting tubular portion (23) are substantially aligned with each other. The backup material (4) according to claim 1, wherein the elastic ring (4a) is described above.
It is.

Then, on the outer periphery of the ring body (5),
The rigid ring (5a) and the elastic ring (4a) is provided with an annular groove portion (45) having a semicircular cross section symmetrical with respect to the boundary line, and the annular groove portion (45) is made of a metal having a circular cross section. C-shaped retaining ring
(3) is fitted. The diameter of the cross section of this retaining ring (3) is
It is substantially the same as that of the annular groove (45), and the retaining ring
The inner diameter of (3) is substantially the same as the minimum diameter of the annular groove (45).

Further, on the inner peripheral surface in the vicinity of the open end of the cylindrical portion (13), there is provided a first rectangular cross section for fitting the retaining ring (3).
An annular groove (11) is provided around. This first annular groove (11)
The insertion cylinder portion (23) is provided at a position corresponding to the annular groove portion (45) at the time when the insertion cylindrical portion (23) is pushed into the substantially final position, and the bottom surface of the first annular groove (11). The diameter of is substantially the same as the outer diameter of the retaining ring (3).

A pair of annular groove portions (25) and (26) are provided side by side on the outer peripheral surface of the insertion cylinder portion (23) closer to the tip than the middle thereof, and these groove portions (25) and (26) are arranged in parallel. A cylindrical portion for insertion into the cylindrical portion (13)
A pair of O-rings (61) and (62) are provided to ensure airtightness between the two when the (23) is inserted. In this case, the outer peripheral surface of the insertion tube portion (23) has a large diameter on the base end side with respect to the formation portion of the groove portions (25) (26) on the tip side from the middle. The inner peripheral surface of the cylindrical portion (13) also has a large diameter portion and a small diameter portion that follow the outer peripheral surface of the insertion cylindrical portion (23). At the final insertion position of the second tubular body (2), the boundaries of the large diameter portion and the small diameter portion are in contact with each other.

An annular convex portion (43) projecting to the outer peripheral side is provided at an end portion of the elastic ring (4a) at the rear side in the insertion direction of the inserting cylindrical portion (23), and the diameter thereof is the above-mentioned. It is set so as to be pressed against the inner peripheral surface of the cylindrical portion (13) in the inserted state. Therefore, in the inserted state, the O-rings (61) (6
In addition to 2), also by the annular convex portion (43), the cylindrical portion
The airtightness between the (13) and the insertion tube portion (23) is secured, and the airtightness is improved. The annular convex portion (43) is the seal portion (41) according to the above-mentioned claim 2. Further, the annular convex portion (43) may not be provided.

Further, a disc-shaped valve body (7) of a type that is automatically closed by a spring is built in the insertion cylinder portion (23). Then, by the shaft portion (8) at the central portion of the annular member (81) fixed to the end surface continuing to the downstream side of the cylindrical portion (13), the valve body (7) is in the valve opening position in the inserted state. It is configured to be pushed into. On the contrary, in a state where the inserting cylinder portion (23) is not inserted into the cylindrical portion (13), the pushing of the valve body (7) by the shaft portion (8) is released, and the valve body (7) is released.
Is automatically closed.

[Actual Connection of First Cylinder (1) and Second Cylinder (2)] In order to bring the first and second cylinders (1) and (2) having the above-mentioned configuration into a connected state. Is the cylindrical part (13) of the first cylindrical body (1)
The inserting cylinder portion (23) of the second cylinder body (2) is pushed into. At this time, since the retaining ring (3) is fitted on the ring body (5) mounted on the outer peripheral surface of the insertion cylindrical portion (23), the retaining ring (3) is Maintained concentrically with section (23). Therefore, the degree of protrusion of the retaining ring (3) from the surface of the insertion tubular portion (23) is uniform in the entire circumferential direction, so that the retaining ring (3) is eccentric when pushed. By doing so, a part thereof will not be excessively caught in the insertion opening portion (130) of the cylindrical portion (13). In addition, since the latter half of the second cylindrical body (2) in the pushing direction of the ring body (5) is the elastic ring (4a), the retaining ring
(3) moves to the elastic ring (4a) side when it abuts on the insertion opening (130) (state of FIG. 2A). As a result, the retaining ring (3) can be contracted, and the retaining ring (3) is reduced in diameter by the guiding action of the insertion opening (130) so that the retaining ring (3) is inserted into the insertion tube (23). Inserted (Fig. 2
-B condition).

When the retaining ring (3) reaches a position corresponding to the first annular groove (11) by the pushing movement of the second tubular body (2), the retaining ring (3) itself Also, the elastic ring (4a) restores its initial shape by the elastic restoring force and is fitted into the first annular groove (11). Then, when the second tubular body (2) is slightly pulled back, the retaining ring (3) moves to the rigid ring (5a) side, and the side wall of the annular groove (45) on the rigid ring (5a) side. And the outer side wall of the first annular groove (11) are engaged with each other via the retaining ring (3) (state of FIG. 2C). As a result, the first and second cylindrical bodies (1) and (2) are connected to each other in a retaining state.

In this case, the rigid ring made of metal in the front half of the annular groove (45) in the pushing direction.
It is formed by (5a). Therefore, in the connected state, repulsive force acts between the first and second cylindrical bodies (1) and (2),
Even if a force in the diameter reducing direction acts on the retaining ring (3) from the side wall of the first annular groove (11), the retaining ring (3) is not reduced in diameter. Therefore, the connection state is reliable.

Further, as shown in FIGS. 1 and 2, when the insertion opening portion (130) is a taper portion whose diameter decreases toward the inside, the reduction operation of the retaining ring (3) becomes smooth. ,
The retaining ring (3) can be inserted into the cylindrical portion (13) more smoothly. When the retaining ring (3) has a circular cross section, it is not always necessary to make the insertion opening (130) a tapered portion, but when the retaining ring (3) has a rectangular cross section, this The tapered portion is particularly effective.

[Other Embodiments] The backup material (4) is the elastic ring (4a) with the above configuration.
It is not limited to. Bottom of the second annular groove (21) and snap ring
An elastic ring (4a) having a rectangular cross section without the sealing portion (41) may be used as long as it is interposed between the elastic ring (4a) and the (3). Also, the second annular groove (21)
Instead of being provided all over in the circumferential direction, it may be provided at predetermined intervals in the circumferential direction. Furthermore, the backup material (4) does not have to be made of rubber. For example, a configuration using a leaf spring or the like may be used.

[0029] The rigid ring (5a) is not limited to being made of metal as long as it has higher rigidity than the elastic ring (4a). For example, it may be made of hard synthetic resin or rubber. In addition, the rigidity of this rigid ring (5a)
Even if the retaining ring (3) fitted onto this is made smaller than the inner diameter of the first cylindrical body (1), the rigidity may be such that this rigid ring (5a) is elastically deformed. In this case, the first cylinder (1)
Even if the second tubular body (2) is forcibly pulled out from the above, the rigid ring (5a) is not damaged. Therefore, this pipe joint can be repeatedly used. Also, when pulling out, the rigid ring
It goes without saying that (5a) may be plastically deformable.

[0030] The retaining ring (3) is not limited to being made of metal as long as it can be elastically deformed in the radial direction. Further, the cross-sectional shape is not limited to the above circular cross section. In addition, the first
The same applies to the sectional shapes of the second annular grooves (11) and (21). . In the pipe joint of the above-mentioned embodiment, both ends thereof are connected to a gas pipe or the like, but one or both of the first cylinder body (1) and the second cylinder body (2) are gas It may be integrated with the constituent members of the pipe. For example, the second cylinder (2)
May be integrally formed at the outlet of the gas plug. or,
It goes without saying that the pipe joint of the present invention can be applied to pipe joints other than gas pipes.

[Brief description of the drawings]

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

FIG. 2 is an explanatory view of a main part when connecting this.

FIG. 3 is an explanatory diagram of another embodiment.

FIG. 4 is a sectional view of a prior art pipe joint.

[Explanation of symbols]

 (1) ・ ・ ・ First cylinder (2) ・ ・ ・ Second cylinder (11) ・ ・ ・ First annular groove (12) ・ ・ ・ Second annular groove (3) ・ ・ ・ Retaining ring (4 ) ・ ・ ・ Backup material

Claims (4)

[Claims] 1. A second annular groove formed of a first tubular body (1) and a second tubular body (2) inserted into the first tubular body (1), the second annular groove being provided around the outer peripheral surface of one of the second tubular bodies (2). A retaining ring (3), which has a diameter larger than the inner diameter of the other first tubular body (1) and is elastically deformable in the radial direction, is externally fitted and retained on the (21) so as to be contractable, and the first tubular body (1) ) To the second
When the retaining ring (3) is fitted into the first annular groove (11) provided around the inner peripheral surface of the first cylindrical body (1) by pushing the cylindrical body (2), the first In the pipe joint in which the second tubular bodies (1) and (2) are connected to each other, a backup material (4) made of an elastic material is provided between the bottom surface of the second annular groove (21) and the retaining ring (3). Intervening pipe fittings. 2. The pipe joint according to claim 1, wherein the backup material (4) is an elastic ring (4a) provided over the entire area of the second annular groove (21) in the circumferential direction. 3. The elastic cylinder (4a) includes the second cylindrical body.
A rigid ring (5a) having a rigidity higher than that of the elastic ring (4a) is integrally connected in front of the pushing direction of (2), and the elastic ring (4a) and the rigid ring (5a) are connected to the second annular groove ( 21) is tightly fitted into the elastic ring (4a) and the rigid ring (5).
An annular groove (45) is provided on the outer circumference of the boundary of (a).
The pipe joint according to claim 2, wherein the retaining ring (3) is fitted on the outside. 4. The elastic ring (4a) is made of rubber, and the elastic ring (4a) is provided on the outer peripheral side between the annular side wall of the second annular groove (21) and the retaining ring (3). The pipe joint according to claim 2 or 3, which is provided with a seal portion (41) which is overhanging and is larger than the inner diameter of the first cylindrical body (1).