JPH089509Y2 - Metal fittings for relaying flexible tubes - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is for connecting metal fittings used for gas pipes or hot water supply pipes for circulating gases such as combustible gas, particularly corrugated metal flexible pipes. The present invention relates to a connection fitting for relaying a flexible metal tube.

[Conventional technology]

In a conventional general metal flexible tube connecting fitting, for example, a connection opening on one end side is connected to a header, and a metal flexible tube is connected to a connection opening on the other end side.

However, recently, not only in such a case, a connecting metal fitting for relay connecting metal flexible tubes has been required.

Therefore, a metal fitting for metal flexible tube relay as shown in FIGS. 3A and 3B has been considered. This is a pair of split retaining members that are set in each connection opening 101 when the nut body 110 is screwed into each of the plurality of tubular connection openings 101 formed in the joint body 100. By pushing the rings 120, 120 by the rear end portion 111 of the nut body 110, the retaining members previously engaged with each other between the peak portions a ₁ , a ₁ of the corrugated metal flexible tube A set in the connection port portion 101. pressing the end portion a ₁ of the metal flexible tube a by the engagement portion 121, 121 of the ring 120, 120 presses the end portion a ₁ of the metal flexible tube a by the pressing action on the annular protrusion 102 that is provided to the joint body 100 I'm supposed to get it.

According to this connection fitting, when the nut body 110 is completely tightened, the engagement portions 121, 121 of the retaining rings 120, 120 are
And the convex portion 102 of the connection port portion 101, the end portion of the metal flexible tube A.
Portion _{1 to} 3 of A ₁ is clamped and connection fitting 10
The convex portion 102 of ₁ and the end portion A ₁ of the metal flexible tube A are metal-touched to form a fireproof seal structure. A concave portion 103 is formed on the outer peripheral portion of the convex portion 102 of the connection port portion 101, and a rubber ring 130 such as an O ring accommodated in the concave portion 103 is connected to the engaging portions 121 and 121 of the retaining rings 120 and 120. It is structured to seal around the metal touch portion by being compressed by the end portion A ₁ of the metal flexible tube A pressed by the convex portion 102 of the mouth portion 101 and the engaging portions 121, 121 of the retaining rings 120, 120. .

[Problems to be solved by the device]

However, when connecting the metal flexible tube A with the conventional connecting fitting, a pair of split retaining rings 120,
The meshing parts 121, 121 of the 120 are replaced by the same peak parts a ₁ , a ₁ of the metal flexible tube A.
The retaining rings 120,120 that engage with each other
To the ring, and then to the retaining ring
Be careful not to lose the shape of the 120, 120, and attach the retaining ring 120, 120 to the connection port 101 of the joint body 100 and the nut body 1
There has been a problem that a careful and troublesome work of covering the connection body with the nut body 110 by screwing the nut body 110 onto the connection portion 101 is required.

On the other hand, regardless of the procedure described above, the nut body 110 is loosely screwed to the connection port portion 101, the retaining rings 120, 120 are previously set therein, and the metal flexible tube A is inserted thereinto to insert the nut. It is not always impossible to connect the metal flexible tube A by tightening the body 110. However, in the case of such a procedure, the pair of retaining rings 120, 120 need to be set in such a state that their meshing portions 121, 121 are separated from each other so that the metal flexible tube A can be fitted therein. If so, the rattling of the pair of retaining rings 120, 120 must be increased inside the connection port 101, so-called dance of the retaining rings 120, 120 occurs, and the metal flexible tube A cannot be inserted well,
Even if it is inserted, the engagement part 121,1 of the retaining ring 120,120
There is a problem that 21 is meshed between the different ridges a ₁ and a ₁ of the flexible metal tube A and a reliable metal touch cannot be formed.

The present invention has been made in view of the above situation,
Not only can the connection work with the retaining rings set inside the connection ports of the joint body be performed smoothly and easily without causing rattling of the retaining rings, but Regardless of the relative positional relationship between the engagement part of the retaining ring and the crest of the metal flexible tube, the engagement part of the retaining ring is properly meshed with the crest of the metal flexible tube due to the shrinking diameter of the retaining ring. It is an object of the present invention to provide a connection fitting for a metal flexible tube relay that can exert a reliable metal touch function, a sealing function, and a reliable and strong retaining function in a connected state.

[Means for Solving the Problems] In order to achieve the above object, the metal fitting for relaying a flexible metal tube according to the present invention has a pair of cylindrical connection ports into which a flexible metal tube having a corrugated cross section is inserted. And a pair of nut bodies that are respectively screwed into the connection opening portion of the joint body in a state of being fitted onto the metal flexible tube, and set inside the connection opening portion where these nut bodies are screwed together. The retaining ring is formed in an annular shape having an inner diameter larger than the outer diameter of the metal flexible tube in a natural state. When the stop ring is reduced in diameter, a meshing portion that meshes between the crests of the metal flexible tube is provided, and the inner end portion of this meshing portion is formed so as to gradually expand from the minimum inner diameter point to both axial sides. , And the tip surface of the meshing part is gradually expanded. Is formed in a direction orthogonal to the axial direction of the meshing portion from the twisted end, the pair of nut bodies has a contact portion that pushes the retaining rings backward when screwed into the connection ports, The pair of connection port portions are formed on both sides in the axial direction of the annular bulging portion integrally formed in the central portion of the inner peripheral surface of the joint body, and these connection port portions respectively have the nut body. A tapered guide surface is formed which slides the retaining ring that is pushed by the forward direction to reduce the diameter of the retaining ring inward in the radial direction and to move forward, and both outer surfaces in the axial direction of the annular bulging portion. Is formed with a recess for fitting and holding a seal ring that is in pressure contact with the end of the metal flexible tube.

[Operation] According to the present invention, the retaining ring is set in advance inside each connection opening with the nut body screwed onto the plurality of connection openings of the joint body. In this set state, the inner diameter of the retaining ring is expanded so as to be larger than the outer diameter of the metal flexible tube, and the retaining ring is attached to the guide surface of the connection port and the contact portion of the nut body. It is sandwiched between and and temporarily fixed so that it does not rattle. Therefore, in this state, when inserting the metal flexible tube into the nut body, the retaining ring and the connection port, the retaining ring does not rattle, so that the metal flexible tube should be inserted smoothly. Is possible. When the metal flexible tube is inserted in this way and the nut body is screwed into the connection opening, the retaining ring is pushed backwards through the abutment portion of the nut body, and the retaining ring is advanced. The ring is guided by the tapered guide surface of the connection port and is radially inwardly reduced, so that the meshing part meshes with the crests of the metal flexible tube. Here, the engagement portion of the retaining ring is formed in a shape that gradually expands from the minimum inner diameter point of the inner end portion to both sides in the axial direction, and the tip end surface is formed in the direction orthogonal to the axial direction from the expanded end. Therefore, regardless of the position of the crest portion of the metal flexible tube inserted into the engagement portion of the retaining ring, that is, at the position where the engagement portion abuts the crest portion of the metal flexible tube, for example. Even though the metal flexible tube elastically deforms as the diameter of the retaining ring decreases, the metal flexible tube eventually slides with respect to the meshing portion, and the meshing portions properly mesh with each other between the mountain portions. It will be. Therefore, in a predetermined relay connection state, the metal flexible tube and each connection opening are surely metal-touched to form a predetermined fireproof seal, and the end of the metal flexible tube and the seal ring are pressed against each other. It is possible to secure the sealing property around the metal touch portion and to exert a reliable and strong retaining function.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1A, 1B and 1C are longitudinal sectional views of a main part of a connecting fitting for relaying a flexible metal tube according to an embodiment of the present invention. In each of these drawings, 1 is a joint body, By integrally forming the annular bulging portion 1A at the central portion of the inner peripheral surface of the joint body 1, a pair of cylindrical connection port portions 10 are formed on both sides in the axial direction of the bulging portion 1A. These pair of connection ports 10
Each has an inner thread 11 formed at one end thereof, and a diameter having a tapered guide surface 12 at the terminal end of the inner thread 11 for advancing while reducing the diameter of a retaining ring to be described later in the radial direction. A small stepped portion 13 is formed, and at the inner end of the stepped portion 13, on both outer surfaces in the axial direction of the annular bulging portion 1A, an annular convex portion 14 and a peripheral portion of the convex portion 14 are provided. A recess 15 for fitting and holding a rubber ring 4 such as an O-ring as a seal ring which is compressed by the end portion A ₁ of the metal flexible tube A and presses against it.
And are formed.

Reference numeral 2 denotes a nut body having an external thread 21 at its tip and an inner surface of the tip forming an outwardly extending tapered tapered contact portion 22. An outer screw 21 of the nut body 2 is screwed onto an inner screw 11 of the connection port portion 10 of the joint body 1.

3 is a retaining ring formed by a cylindrical body, which is the second A
As shown in the drawing, the front end of the cylindrical portion 31 has a cutout shape, and when the retaining ring 3 is reduced in diameter, it is meshed between the peak portions a ₁ and a ₁ of the corrugated metal flexible tube A. The mating portion 32 is provided inward, and the inner end portion 32a of the meshing portion 32a is formed so as to gradually expand from the minimum inner diameter point to both sides in the axial direction, and the tip surface 32b of the mesh portion 32 is formed. From the end of the inner end portion 32a to the meshing portion 32
Is formed flat in the direction orthogonal to the axial direction of the guide surface 12 of the connection port 10 on the outer periphery of the engagement portion 32.
A tapered surface 33 that slides with is formed. Further, on the outer periphery of the rear end of the cylindrical portion 31, a tapered surface 34 that slides on the contact portion 22 of the nut body 2 is formed. The retaining ring 3 has a meshing portion 32 whose inner diameter in the natural state is larger than the outer diameter of the corrugated metal flexible tube A, and moreover, the cutout portion shown in FIG. 2A. When the entire retaining ring 3 is reduced in diameter against its own elasticity so that the gap 35 of the stopper ring 3 is completely closed as shown in FIG.
The inner peripheral diameter of the metal flexible tube A is equal to or slightly smaller than the outer peripheral diameter of the valley portion a ₂ of the metal flexible tube A.

When the outer screw 21 of the nut body 2 is screwed into the inner screw 11 of the connection port 10 of the joint body 1 and the retaining ring 3 is set inside them, the retaining ring 3 to be set is tapered in the natural state. Even if there are some differences in the outer diameters of the surface 33 and the tapered surface 34, the retaining ring 3 is sandwiched and fixed between the guide surface 12 of the connection port portion 10 and the contact portion 22 of the nut body 2. When the nut body 2 is screwed onto the retaining ring 3, the retaining ring 3 is fixedly set without rattling. Therefore, when the metal flexible tube A is inserted into the connection port 10, the retaining ring 3 does not rattle and it is difficult to insert it. Even in such a set state, the engagement portion 32 of the retaining ring 3
The inner diameter of the metal flexible tube is larger than the outer diameter of the mountain portion a ₁ of the flexible metal tube, and the gap 35 is kept open.

When connecting the corrugated metal flexible tube A, as shown in FIG. 1A, the metal flexible tube A is connected to the end portion A ₁ at the connection port portion 10 in which the retaining ring 3 is set as described above. Convex part 14 of part 10
After inserting the nut body 2 screwed into the connection port portion 10 in the direction of the arrow X in FIG. 1B. By doing so, the retaining ring 3 is pushed by the abutting portion 22 of the nut body 2, and accordingly, the tapered surface 33 of the retaining ring 3 slides on the guide surface 12 of the connection port portion 10 to form the retaining ring 3. As it advances in the radial direction while reducing its diameter, the meshing portion 32 of the retaining ring 3 meshes between the peaks a ₁ and a ₁ of the metal flexible tube A in the middle thereof. Here, the engagement portion 32 of the retaining ring 3 has a shape that gradually expands from the minimum inner diameter point of the inner end portion 32a to both sides in the axial direction, and the tip surface 32b is orthogonal to the axial direction from the expanded end. Since the meshing portion 32 of the retaining ring 3 and the mountain portion a ₁ of the metal flexible tube A are located in the same direction, the meshing portion 32 has, for example, the mountain portion a _{1 of the} metal flexible tube A. Even if the positional relationship is such that the metal flexible tube A is elastically deformed as the diameter of the retaining ring 3 is reduced, the metal flexible tube A finally slides with respect to the meshing portion 32 and becomes a mountain. The meshing portion 32 is appropriately meshed between the portions a ₁ and a ₁ , and the end portion A ₁ is pressed against the convex portion 14 of the joint body 1. And the nut body 2
Is completely screwed in (in this state, the tapered surface 33 of the retaining ring 3 exceeds the guide surface 12 and the retaining ring 3 is backed up from the outside by the inner surface of the stepped portion 13). As shown in FIG. 2 and FIG. 2B, a portion of the end portion A ₁ of the metal flexible tube A is clamped between the meshing portion 32 and the convex portion 14, and the end portion of the metal flexible tube A is clamped. At the same time that A ₁ makes a metal touch with the convex portion 14 to form a fireproof seal, and at the same time, the rubber ring 4 is compressed by the end A ₁ of the metal flexible tube A compressed as described above. 4 is pressed against the surface of the recess 15 to seal the periphery of the metal touch portion, and the retaining ring 3 is provided between the ridges a ₁ and a ₁ of the end A ₁ of the metal flexible tube A. The meshing portion 32 is surely meshed with each other, and a reliable and strong retaining action is exhibited.

Since the operation described above is exhibited at the connection points of the metal flexible tubes A to all the connection ports 10, it is possible to quickly connect the plurality of metal flexible tubes A to each other in a reliable sealed state. Is.

It should be noted that an expanded graphite ring may be interposed between the rubber ring 4 and the metal touch portion. If this is done, the rubber ring 4 may melt or burn due to heat during a fire or the like. When the sealing property of the rubber ring 4 is impaired, the expanded graphite ring swells by receiving heat at that time, which helps maintain the sealing property around the metal touch portion. In addition, the sealing property is exhibited by the metal touch portion regardless of whether the ring made of expanded graphite is interposed or not.

In the connecting step described above, when the retaining ring 3 is reduced in diameter and its meshing portion 32 is brought into pressure contact with the outer peripheral surface of the metal flexible tube A, the frictional engagement force between the guide surface 12 and the tapered surface 33 hits the above. If it is configured to be larger than the frictional engagement force between the portion 22 and the tapered surface 34, after the engagement portion 32 of the retaining ring 3 is pressed against the outer peripheral surface of the metal flexible tube A, the nut body 2 Even if the rotational force due to the screwing in is applied to the retaining ring 3, the retaining ring 3 does not rotate together with the nut body 2 but advances while reducing the diameter, and the twisting force is applied to the metal flexible tube A. The situation in which the flexible metal tube A is twisted in addition does not occur. Further, since the contact portion 22 of the nut body 2 is formed in a tapered shape, it is useful not only for pushing the retaining ring 3 backward, but also for facilitating reduction of the retaining ring 3. However, even when the contact portion 22 is replaced with a vertical surface in a direction orthogonal to the axial center of the nut body 2, the stopper surface is retained by the action of the guide surface 12 of the connection port portion 10 and the tapered surface 33 of the retaining ring 3. The diameter reduction of the ring 3 is promoted, and the retaining ring 3 exhibits an action of reducing the diameter while advancing. Therefore, in this case, the vertical surface functions to push the retaining ring 3 while allowing the diameter of the retaining ring 3 to be reduced.

[Effects of the Invention] As described above, according to the present invention, a nut-shaped retaining ring having an internal diameter whose inner diameter is set larger than the outer diameter of the flexible metal tube in a natural state is screwed into the nut body. And the tapered guide surface provided at the connection opening of the joint body so as to face the contact portion of the nut body and the contact portion of the nut body. By being configured to be sandwiched between and to be temporarily fixed, a retaining ring is set in advance inside the connection port in a state where the nut body is screwed to each connection port, After that, when adopting a rational work procedure such as inserting a metal flexible tube and screwing in the nut body, even if there is some error in the outer diameter of the retaining ring,
This rattling of the retaining ring can be prevented, and the metal flexible tube can be inserted very smoothly and easily, and the connection work can be facilitated and ensured as compared with the conventional case.

Moreover, the engagement portion of the retaining ring has a shape that gradually expands from the minimum inner diameter point of its inner end portion to both sides in the axial direction, and its tip surface is formed in a direction orthogonal to the axial direction from the expanded end. Therefore, even if the relative position is such that the meshing part hits the crest of the metal flexible tube, the metal retaining tube is prevented from deforming within the elastic range due to the shrinkage of the metal retaining ring while retaining the metal retaining tube. The meshing parts of can be accurately meshed with each other between the crests of the metal flexible tube, and therefore, the plurality of metal flexible tubes and the respective connection ports can be reliably metal-touched in a predetermined connection state. The effect of being able to reliably form a prescribed fireproof seal and to exert a reliable and strong retaining function while ensuring the sealability by the seal ring around it and the end of the metal flexible tube being pressed against each other. Played, especially It is possible to achieve a significant improvement in the safety of the relay connection fitting pipes together to handle like sex gas.

[Brief description of drawings]

FIGS. 1A and 1B are partial cross-sectional views showing a portion corresponding to a connection opening portion on one side of a metal flexible tube relay connection fitting according to an embodiment of the present invention, and FIG. 1C is a pair of the connection fittings. A partial cross-sectional view showing a portion corresponding to the mouth portion, FIGS. 2A and 2B are a metal flexible tube and a pull-out tube seen from a portion along line IIA-IIA in FIG. 1A and line IIB-IIB in FIG. 1C, respectively. FIG. 3A is a sectional view showing a retaining ring, FIG. 3A is a partial sectional view of a conventional example, and FIG. 3B is a sectional view showing a positional relationship between a metal flexible tube and a retaining ring in the conventional example. A ... Metal flexible tube, 1 ... Joint body, 2 ... Nut body,
3 ... retaining ring, 10 ... connection port, 12 ... guide surface, 14 ... convex portion, 22 ... contact portion, 31 ... cylindrical portion, 32 ...
… Mating part, 33 …… Tapered surface of retaining ring.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-61-171990 (JP, A) Actually open 62-97386 (JP, U) Actually open 3-69785 (JP, U) Actually open 3- 75388 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A joint main body having a pair of cylindrical connection ports into which a metal flexible tube having a corrugated cross section is inserted, and a connection port of the joint main body that is externally fitted to the metal flexible tube. A pair of nut bodies to be screwed in and a pair of retaining rings that are respectively set inside the connection ports where these nut bodies are screwed together are provided. The flexible tube is formed in a cutout shape larger than the outer diameter of the flexible tube, and when the retaining ring is reduced in diameter, a meshing portion is provided between the crests of the metal flexible tube. The inner end portion of the meshing portion is formed so as to gradually expand from the minimum inner diameter point to both sides in the axial direction, and the tip surface of the meshing portion is formed in a direction orthogonal to the axial direction of the meshing portion from the gradually expanded end. The above-mentioned pair of nut bodies are There is a contact portion that pushes back each of the retaining rings when screwed into the connection opening portion, and the pair of connection opening portions are annular bulges integrally formed in the central portion of the inner peripheral surface of the joint body. Are formed on both sides in the axial direction of the portion, and slip-prevention rings pushed by the nut bodies are slid on these connection ports, respectively, and the slide-out prevention rings are advanced while being radially inwardly reduced. A tapered guide surface is formed, and a recess for fitting and holding a seal ring that is in pressure contact with the end of the metal flexible tube is formed on both outer surfaces of the annular bulging portion in the axial direction. A connecting fitting for relaying a flexible metal tube, which is characterized in that