JPH085436Y2 - 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 retainers that are previously meshed 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. ring pressing the end portion a ₁ of the metal flexible tube a by the projecting portion 121, 121 of the 120, 120, 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 It can be pressed.

According to this connection fitting, when the nut body 110 is completely tightened, the protruding portions 121, 121 of the retaining ring 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 housed in the concave portion 103 serves as a protruding portion 121, 121 of the retaining ring 120, 120. The end portion A ₁ of the flexible metal tube A pressed by the convex portion 102 of the connection port portion 101 and the protruding portions 121, 121 of the retaining rings 120, 120 are compressed to seal the periphery of the metal touch portion. ing.

[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 protruding portions 121, 121 of the 120 are engaged with each other between the same peaks a ₁ , a ₁ of the metal flexible tube A so that the retaining rings 120, 120 are annularly aligned, and then the retaining ring 12 is annularly aligned.
Be careful not to lose the shape of the 0, 120, and attach the retaining ring 120, 120 to the connection port 101 of the joint body 100 and the nut body 110.
There has been a problem that a careful and troublesome work of covering the nut body 110 and screwing the nut body 110 into the connection port 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 a state in which the overhanging portions 121, 121 are separated from each other so that the metal flexible tube A can be fitted therein. Then, the rattling of the pair of retaining rings 120, 120 must be increased inside the connection port portion 101, so-called dancing of the retaining rings 120, 120 occurs, and the metal flexible tube A cannot be inserted well.
Overhang 121,1 of retaining ring 120,120 even if it is inserted
There is a problem in that 21 cannot mesh with the mutually different ridges a ₁ and a ₁ of the metal flexible tube A to form a reliable metal touch, and the fireproof sealability cannot be secured.

The present invention has been made in view of the above situation,
The connection work with the retaining ring set in advance in the joint where the corrugated metal flexible tube is inserted can be performed smoothly and easily without causing rattling of the retaining ring. When a plurality of metal flexible tubes are connected to each other, a predetermined sealing function can be ensured, and the overall size of the joint body including the plurality of connecting parts can be made compact and cost-effective. It is an object of the present invention to provide a connecting fitting for relaying a flexible metal tube that can save the space required.

[Means for Solving the Problems] In order to achieve the above object, a metal flexible tube relay connection fitting according to the present invention is inserted with a metal flexible tube having a corrugated cross section and a cut end face. Joint body having a plurality of tubular connection ports, a plurality of nut bodies screwed into the above-mentioned connection ports in a state of being externally fitted to the metal flexible tube, and these nut bodies are screwed into the respective connection ports. With a plurality of retaining rings that are set inside each connection port in a combined state,
In the natural state, each of the retaining rings has a truncated circular shape whose inner diameter is set to be larger than the outer diameter of the metal flexible tube, and its cross-sectional shape is circular, elliptical or a polygon corresponding thereto. Each of the nut bodies is a cap nut having a U-shaped cross section, and the outer ring portion thereof has a female screw threaded to a male screw thread formed on the outer peripheral portion of the tip of each connection port portion, and the inner ring portion thereof. Pushing the retaining ring at the tip of the portion, and having a contact portion that allows the retaining ring to be reduced in diameter, each connection port portion of the joint body has a male screw to which the female screw of the nut body is screwed, A tapered guide surface facing the abutment portion of the nut body so as to slide and guide the retaining ring pushed by the nut body and to advance the retaining ring radially inward. This taper A straight surface that follows the guide surface and an annular projection that abuts the cut end surface of the metal flexible tube that engages with the retaining ring that is formed at the rear end of this straight surface and has a reduced diameter and is pressed by the retaining ring. And a recess for fitting and holding a seal ring formed around the outer periphery of the annular convex portion and compressed by an inclined portion continuous with the cut end face of the metal flexible tube in a state where the nut body is completely screwed. It is characterized by having.

[Operation] According to the present invention, the seal ring is fitted and held in the recess of each connection opening of the joint body, and the internal thread of each connection opening is fitted with the female thread of the nut body screwed onto the male thread at the tip. Set the retaining ring on each of them in advance. In this set state, the inner diameter of each retaining ring is expanded so that it is larger than the outer diameter of the metal flexible tube, and each retaining port of the retaining ring is connected to the guide surface and the nut body. It is temporarily fixed so that it will not get rattled by being caught between the contact part. Therefore, in this state, when the metal flexible tubes are inserted into the nut body, the retaining ring and the connection port portion, the retaining rings do not rattle, so that the metal flexible tubes can be smoothly moved. It is possible to plug in. When a plurality of flexible metal tubes are inserted in this way and then the nut bodies are screwed into the respective connection ports, the retaining rings are pushed back through the contact parts at the inner ring tip ends of these nut bodies. At this time, the retaining ring is guided by the tapered guide surface of the connection port portion and is advanced while being radially reduced inward. In this way, as the nut body is screwed in, the retaining ring is reduced in diameter while advancing and engages with the valley portion of the metal flexible tube, and in this engaged state, each retaining ring is straight at each connection port. The surface prevents the diameter from expanding due to being backed up from the outside. In this way, when the nut body is completely screwed in, the cut end face at the valley portion of the metal flexible tube is pressed against the annular convex portion of each connection opening portion and metal-touches to form a predetermined fireproof seal. At the same time, the seal ring is compressed on the outer periphery thereof without being damaged by the inclined portion of the end portion of the metal flexible tube, and the outer periphery of the metal touch portion is reliably hermetically sealed.

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

FIG. 1A and FIG. 1B are longitudinal sectional views of a main part of a metal flexible tube relay connection fitting according to an embodiment of the present invention.

Reference numeral 1 is a joint body having a plurality of tubular connection ports 10. Each connection port 10 has an external thread 11 formed at one end thereof and a tapered guide on the inner peripheral portion of the one end. surface
A straight surface 13 having 12 and continuing to the guide surface 12 thereof
An annular convex portion 14 is formed at the innermost end of the, and a concave portion 15 is formed around the convex portion 14.

Reference numeral 2 denotes a nut body having a U-shaped cross-sectional shape. An inner thread 22 is formed on an outer ring portion 21 of the nut body, and a tip portion of the inner ring portion 23 is a contact portion 24. This nut body 2 has its inner thread
22 is screwed onto the outer screw 11 of the connection port 10, and the contact part 24 faces the guide surface 12 of the connection port 10.

Reference numeral 3 is a retaining ring having a circular cross-sectional shape, and has a truncated circle shape as shown in FIG. 2A. The retaining ring 3 is made of a metal flexible tube A having a corrugated inner peripheral diameter in a natural state.
The outer diameter of the retaining ring 3 is larger than the outer diameter of the ring, and the gap 31 of the missing circle shown in FIG. 2A is completely closed as shown in FIG. 2B. crests of the inner peripheral diameter of the metal flexible tube a is when a reduced diameter Te a ₁
It is designed to be slightly smaller than the outer diameter of.

The nut body 2 is attached to the outer screw 11 of the connection port 10 of the joint body 1 described above.
When screwing the inner screws 22 of the above and setting the retaining ring 3 inside them, even if there is a slight difference in the outer diameter of the retaining ring 3 to be set in the natural state, the connection port
If the nut body 2 is screwed so that the retaining ring 3 is sandwiched and fixed between the guide surface 12 of the 10 and the contact portion 24 of the nut body 2, the retaining ring 3 is fixed without rattling. Be set automatically. Therefore, the metal flexible tube A is connected to the connection port.
The retaining ring 3 will not rattle when inserting it into the 10 and it will not be difficult to insert it. Even in such a set state, the inner diameter of the retaining ring 3 is equal to the peak of the metal flexible tube A.
It is larger than the outer diameter of a _{1 and} the gap 31 is kept open.

When connecting the metal flexible tube A having a trough portion a ₂ having a cut end surface in a corrugated cross-section to the connection fitting having the above-described configuration, first, the O-ring as a seal ring is previously provided in the recess 15 of the connection opening 10. After the rubber ring 4 is fitted and held, the retaining ring 3 is set inside the connection port 10 as described above, and in this state, the metal flexible tube is connected to the connection port 10 as shown in FIG. 1A. A at its end
After inserting the cut end surface a ₃ of A _{1 to} a position where the cut end surface a ₃ comes into contact with the convex portion 14 of the connection opening portion 10, the nut body 2 screwed onto the connection opening portion 10 is screwed in. In this way, the retaining ring 3 is pushed by the abutting portion 24 of the nut body 2, and accordingly, the retaining ring 3 slides on the guide surface 12 of the connection port portion 10 while reducing the diameter inward in the radial direction. When the metal flexible tube A is advanced, the retaining ring 3 meshes between the ridges a ₁ and a ₁ of the metal flexible tube A so that the end A ₁ of the metal flexible tube A is protruded from the connection port 10. Press on 14. Then, the nut body 2 is completely screwed in (the tapered surface 33 of the retaining ring 3 may exceed the guide surface 12 in this state, and the retaining ring 3 may be backed up from the outside by the straight surface 13). ), As shown in FIGS. 1B and 2B, a portion of the end portion A ₁ of the flexible metal tube A having a few peaks extends from the protrusion 32 of the retaining ring 3 and the protrusion 14
And the end portion A ₁ of the metal flexible tube A is pressed against the convex portion 14
At the same time with the metal touch to configure the fireproof seal,
The rubber ring 4 fitted and held in the recess 15 is compressed by the inclined part of the end portion A ₁ of the metal flexible tube A which is pressed and pressed against the surface of the recess 15 to make the metal touch. The outer periphery of the portion is hermetically sealed, and the clamped end portion A _{1 of} the metal flexible tube A engages with the retaining ring 3 in the pulling direction to exert a reliable retaining action.

Since the operation described above is exhibited when the metal flexible tubes A are connected to all the connection ports 10, the use of the connecting fittings allows the metal flexible tubes A, A to be easily and quickly connected to each other.
In addition, it is possible to secure a predetermined sealing function for connection.

If necessary, a ring made of expanded graphite may be interposed between the rubber ring 4 and the metal touch portion. If this is done, the rubber ring 4 may be exposed to heat from a fire or the like. When the sealability of the rubber ring 4 is impaired due to melting or burning, the expanded graphite ring is expanded by receiving heat at that time, which helps to maintain the sealability 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 contact portion 24 of the nut body 2 is pressed by the action of the guide surface 12 of the connection port portion 10 to reduce the diameter of the retaining ring 3, the retaining ring 3 reduces in diameter while advancing. Will play a role in boosting while allowing the diameter reduction.

In this embodiment, the case where the retaining ring 3 has a circular cross-sectional shape has been described, but the retaining ring 3 may have an oval cross-sectional shape such as a triangle, a quadrangle, a pentagon or a trapezoid. It may be. In short, the retaining ring 3 may have a circular shape, an elliptical shape, or a polygonal shape corresponding to it so that it can be meshed between the peaks a ₁ and a ₁ of the metal flexible tube A due to its diameter reduction. Therefore, the cylindrical retaining ring is excluded from the scope of the present invention. Further, in the above embodiment, the outer threads 11 are formed on the plurality of connection ports 10 of the joint body 1, and the inner threads are formed on each nut body 2.
Although the description has been given with the case where 22 is formed, an inner thread may be formed on each connection port 10 side and an outer thread may be formed on each nut body 2 side.

[Advantage of the Invention] As described above, according to the present invention, each nut is provided with a plurality of retaining rings in an annular shape, the inner diameter of which is set larger than the outer diameter of the flexible metal tube in the natural state. As the body is screwed in, the diameter is reduced while advancing, and the diameter reduction state is configured to be backed up by the straight surface of each connection port in the joint body, and these retaining rings are attached to each nut body. Each nut body is configured to be temporarily fixed by being sandwiched between a contact portion at the tip of the inner ring portion and a tapered guide surface provided at each connection opening portion so as to face the contact portion. A rational work procedure in which a retaining ring is set in advance inside each connection port in a state where it is screwed into each connection port, and then multiple metal flexible tubes are inserted and each nut body is screwed in. Adopted At this time, even if there is some error in the outer diameter of each retaining ring, the retaining rings can be prevented from rattling, and a plurality of metal flexible tubes can be inserted very smoothly and easily. In addition, when the nut body is screwed in after inserting each metal flexible tube, the retaining ring is slidably guided to the tapered guide surface of each connection port to reduce the diameter while advancing, and the valley portion of each metal flexible tube. It is possible to securely engage with each other, and thereby, the connecting end face at the valley portion of each metal flexible tube is pressed against and brought into contact with the annular convex portion of each connection opening portion of the joint main body to provide a fire-resistant seal by metal touch. The structure can be reliably formed. At the same time, on the outer periphery of the metal touch portion, the inclined portion of the end of each metal flexible tube compresses the seal ring fitted and held in the recess formed around the outer periphery of the convex portion of each of the above-mentioned connection port portions to compress the metal touch The airtight seal portion can be formed around the outer periphery of the portion, and the tip of the metal flexible tube is not pierced and damaged by the seal ring forming the airtight seal portion. Therefore, while a work of connecting a plurality of metal flexible tubes can be performed easily and reliably, a plurality of metal flexible tubes are relay-connected to each other while ensuring a strong retaining function and a reliable sealing performance. be able to.

Moreover, by using a cap nut having a U-shaped cross section as the nut body, it is possible to form a female screw for screwing the connection opening portion and a contact portion that pushes the retaining ring backward within a narrow axial width. It is possible, and the joint body as well as the nut body can be shortened in the axial direction. Therefore, the joint body can be made compact and compact, and the cost can be reduced. There is an effect that the space occupied by the connecting portion can be reduced and the space required for connecting a plurality of metal flexible tubes can be reduced.

[Brief description of drawings]

FIG. 1A is a partial cross-sectional view showing a portion corresponding to one side connection opening portion of a metal fitting flexible tube relay connection fitting according to an embodiment of the present invention, and FIG. 1B corresponds to both connection opening portions of the connection fitting. 2A and 2B are sectional views showing the parts to be
FIG. 3A is a sectional view showing the metal flexible tube and the retaining ring as seen from the portion along the line IIA-IIA in FIG. 1A and the line IIB-IIB in FIG. 1B.
FIG. 3 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, 24 ... contact portion.

Claims (1)

[Scope of utility model registration request] 1. A joint main body having a plurality of cylindrical connection ports into which a metal flexible tube having a corrugated cross section and a cut end surface being a cut end surface is inserted, and the joint body externally fitted to the metal flexible tube. A plurality of nut bodies to be screwed into each connection opening portion, and a plurality of retaining rings that are set inside each connection opening portion in a state where these nut bodies are screwed into each connection opening portion are provided. The ring, in its natural state, has an inner diameter that is set to be larger than the outer diameter of the metal flexible tube, and has a cutout shape, and its cross-sectional shape is circular, oval, or a polygonal shape similar to these. Each of the nut bodies is a cap nut having a U-shaped cross section, and the outer ring portion thereof has a female screw threaded to a male thread formed on the outer peripheral portion of the tip of each of the connection port portions, and at the tip of the inner ring portion thereof. Push the retaining ring back and Has a contact portion that allows the diameter of the female ring to be reduced, and each connection port of the joint body slides and guides the male screw to which the female screw of the nut body is screwed and the retaining ring pushed by the nut body. And a taper-shaped guide surface facing the contact portion of the nut body so as to be advanced while radially contracting the retaining ring radially inward, a straight surface continuous with the taper-shaped guide surface, and a straight surface. An annular convex portion which is formed at the innermost end of the metal and is abutted against the cut end surface of the metal flexible tube that is pressed by the retaining ring that is reduced in diameter, and the outer periphery of the annular convex portion And a recess for fitting and holding a seal ring that is compressed by an inclined portion that is continuous with the cut end surface of the metal flexible tube when the nut body is completely screwed in. Fittings for tube relay.