JP2012132543A - Metallic flexible pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metallic flexible pipe which can secure the sealing performance and retaining of a flexible pipe and a rotating nipple by a configuration not requiring welding and having a small parts count.SOLUTION: It is formed in the tip tapered thread part 43a which is larger than the inside diameter of the rotating nipple 5 and smaller than the tip root diameter of the male screw 52 of the perimeter face 5a, the rear face side 43c of this tip tapered thread part 43a counters to 5d of the tip face of the rotating nipple 5, the seal ring 10 is inserted between the root part 42a of the flexible pipe 4 in the area where is covered by the rotating nipple 5 and the inner circumference face 5b of the rotating nipple 5, and the alignment ring 20 is inserted between the more tip root part 42b than the root part 42a, in which the seal ring 10 is inserted, and the rear root part 42c and the inner circumference face 5b of the rotating nipple 5, For this reason, it can prevent that the flexible pipe 4 moves to the axial direction of L back, falls out from the rotating nipple 5 and comes out of it without using welding and other member.

Description

  The present invention relates to a metal flexible tube that is used by circulating a fluid in a pipe line.

  Conventionally, pipes for distributing fluids such as liquid (for example, tap water and sewage), gas (for example, gas), and powder have displacement absorption and are made of metal from the viewpoint of high flexibility in the piping direction. Flexible tubes are widely used.

  For example, in the conventional metal flexible tube disclosed in Patent Document 1, when a stainless steel metal flexible tube is connected to another tube member, a sleeve is provided on the tip side of the metal flexible tube. The rear end is fixed by welding, the sleeve and the other pipe member are arranged in abutment, and the two are connected using a cap nut. Specifically, an enlarged portion having a smaller outer diameter is provided on the outer periphery on the front end portion side of the sleeve through a stepped portion from the butt end portion, while the cap nut has a rear end side corresponding to the enlarged portion Has a slightly larger inner diameter than the outer periphery of the butt end of the sleeve, and a concave peripheral portion is provided in the axially intermediate portion of the inner diameter surface, and a cap nut is inserted from the tip end side of the sleeve. The incised metal retaining wire member is attached to the concave peripheral portion from the metal flexible tube side with its outer diameter reduced, and in this state, the sleeve and the other tube member are interposed with packing. And then connecting the cap nut and the other pipe member by screwing together.

JP 2000-81176 A (refer to FIG. 2 in particular)

However, in the conventional metal flexible tube as disclosed in Patent Document 1, when connecting a stainless steel metal flexible tube and another tube member, the tip side of the metal flexible tube The sleeve is fixed by welding, the sleeve and the other pipe member are arranged in abutment, and the two are connected using a cap nut.
As described above, the sleeve and the metal flexible tube need to be welded, which not only takes a long time for welding work, but also requires heat treatment for removing the thermal stress by welding or solidifying the material. The assembly time was significantly long, which caused an increase in cost. Further, the assembly man-hours increase and the manufacturing time increases, so that the overall unit price of the product increases.

  In view of the above problems, an object of the present invention is a metal that can ensure sealing performance and retaining of a flexible tube and a rotating nipple with a simple configuration that does not require welding to prevent fluid leakage and has a small number of parts. The object is to provide a flexible tube.

  In order to solve the above problems, the metal flexible tube according to the present invention has a rotating nipple externally fitted to at least the tip of the flexible tube, and a male screw is provided on the outer peripheral surface of the tip of the rotating nipple. A crest on the distal end side of the flexible tube is crushed in the axial direction and formed into a front expanded crest having an outer diameter larger than the inner diameter of the rotating nipple and smaller than the tip trough diameter of the male thread of the rotating nipple. In addition, the rear surface side of the front enlarged ridge portion is opposed to the tip surface of the rotating nipple, and the valley of the flexible tube in the region covered with the rotating nipple and the inner peripheral surface of the rotating nipple. In between, a seal ring that seals between them is fitted, and between the trough on the tip side of the trough where the seal ring is fitted and the inner peripheral surface of the rotating nipple, Alignment rings for securing the sealing performance by the pressure contact of the seal ring are fitted between the valley portion on the rear side of the valley portion where the seal ring is fitted and the inner peripheral surface of the rotary nipple, respectively. It is characterized by.

According to the metal flexible tube of the present invention, it is formed on the front expanded ridge having an outer diameter larger than the inner diameter of the rotating nipple, and the rear surface side of the forward expanded ridge is the tip of the rotating nipple. Because it faces the surface, it is possible to prevent the flexible tube from moving out of the rotating nipple in the axial direction without using welding or other members (in other words, the rotating nipple is at the tip of the flexible tube). Can be prevented from coming off the outside).
Moreover, the sealing performance between the distal end portion of the flexible tube and the rotating nipple can be ensured by the seal ring interposed between the distal end portion of the flexible tube and the rotating nipple.
Therefore, conventional sleeves and welding are not required, the number of members can be reduced, the manufacturing time can be shortened, the cost can be reduced, and fluid leakage can also be prevented.

At that time, the maximum outer diameter of the front expanded ridge portion is formed to be larger than the inner diameter of the inner diameter portion of the rotating nipple and smaller than the tip valley diameter (minimum outer diameter) of the male screw portion of the rotating nipple.
As a result, when the male threaded portion of the rotating nipple is screwed and connected to the female threaded portion on the inner peripheral surface of the connecting portion provided on the connection target (for example, piping, joint, equipment, facility, etc.), it may become an obstacle. Absent.

In addition, a seal ring that seals between the valley portion of the flexible tube and the inner peripheral surface of the rotary nipple in the region covered with the rotary nipple is fitted, and the seal ring is press-fitted before and after the seal ring. A centering ring for securing the sealing performance by is fitted.
With such a configuration, even if impact force from internal fluid or external force acts on the flexible tube, the rotating nipple and each axis of the flexible tube can be inserted into the seal ring by the alignment ring. Therefore, it is possible to prevent a large deviation from occurring, and to keep the seal ring pressed against the flexible pipe and the rotary nipple over the entire circumference, thereby effectively preventing fluid leakage in the flexible pipe.

Further, as an aspect for restricting or suppressing the movement of the rotating nipple in the axial direction rearward, an enlarged rear end opening that is radially outwardly enlarged is formed at the rear end opening of the inner diameter portion of the rotating nipple, and the position corresponding to the enlarged rear end opening The crest portion of the flexible pipe is squeezed in the axial direction to form a rear enlarged crest portion having an outer diameter larger than the inner diameter of the inner diameter portion of the rotary nipple, and this rear enlarged crest portion is inserted into the enlarged rear end opening portion. It is possible to adopt a configuration that
With such a configuration, it is possible to prevent the rotating nipple from moving unintentionally in the axially rearward direction from the distal end region of the flexible tube.

It is preferable that the above-mentioned front diameter-expanded crest is configured to crush the crest on the distal end side of the flexible tube in a plurality of axial directions.
By adopting such a configuration, the number of the front expanded crests facing the front end surface of the rotating nipple becomes plural, so that the rigidity of the front expanded crests is improved and the flexible tube is pulled out from the rotating nipple. The pull-out preventing force that prevents the rotation (in other words, the preventive force that prevents the rotating nipple from coming off from the distal end portion of the flexible tube) can be greatly improved as compared with a single case.

  In addition, the external thread formed on the outer peripheral surface of the rotating nipple is screwed into the internal thread on the inner peripheral surface of the connection target, and the front end surface of the external thread portion of the rotating nipple and the connection target facing this front end surface It is possible to adopt a structure in which the front diameter-expanded crest portion is narrowly attached to the receiving surface behind the female screw portion. If this tightly-fitting structure is adopted, fluid leakage in the flexible pipe can be effectively prevented at the narrowed part, and the flexible pipe is not easily pulled out even if a strong pulling force acts on the flexible pipe. The pull-out prevention force of the flexible tube can be greatly improved. In addition, if the number of the front diameter-expanded crests is plural in the narrowed portion, the effect of preventing fluid leakage in the flexible pipe and the effect of preventing the drawing of the flexible pipe can be further improved.

It is a half notched cross-sectional view of a metal flexible tube according to an embodiment of the present invention. It is the elements on larger scale of the A section enclosed with the dashed-dotted line in FIG.

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

<1. About Configuration of Metal Flexible Tube 1 According to One Embodiment and its Components>
As shown in FIG. 1 and partially enlarged FIG. 2, the metal flexible tube 1 according to the present embodiment includes a flexible tube 4 and a rotating nipple 5 that is externally fitted to the distal end portion in the axial direction L of the flexible tube 4. And.

The material of the flexible tube 4 is made of metal. In particular, those made of stainless steel that have corrosion resistance, flexibility, and flexibility and can cope with slight displacement in the longitudinal direction and temperature expansion and contraction are preferable.
The outer periphery of the flexible tube 4 has a corrugated cross-sectional shape in which peaks 41 and valleys 42 are alternately formed in the axial direction L.

The rotating nipple 5 has a cylindrical shape and is made of metal.
A male screw portion 52 is provided on the outer peripheral surface 5 a of the tip portion 51 of the rotating nipple 5. As a result, the male threaded portion 52 of the rotating nipple 5 can be screwed and connected to the female threaded portion Y on the inner peripheral surface of the end of the connecting portion X provided in the connection target (for example, piping, joint, equipment, facility, etc.).
Further, the rotary nipple 5 is provided with an enlarged rear end port 53 b formed at a rear end port 53 a of the inner diameter portion 53 larger than the inner diameter of the inner diameter portion 53.

And the boundary part 54 of the radial direction internal peripheral surface 5b of the internal diameter part 53 of the rotation nipple 5 and the radial direction internal peripheral surface 5c of the expansion rear end port 53b is an annular shape upright in the radial direction so as to be stepped. It is formed on the engagement surface.
The engagement surface of the boundary portion 54 is not limited to an upright surface, and may be an inclined surface having a diameter that is smaller toward the distal end portion 51 side of the rotating nipple 5 or may be stepped.

<2. More specific explanation>
Subsequently, the embodiment will be described more specifically.

As shown in FIGS. 1 and 2, the crest 41 a on the distal end side of the flexible tube 4 is crushed in the axial direction until the opposed inner peripheral surfaces are in contact with or in close contact with each other. It is formed in the front enlarged crest 43a having a large outer diameter smaller than the tip trough diameter of the male screw 52 of the rotary nipple 5, and the rear surface side 43c of the front enlarged crest 43a is the front end surface 5d of the rotary nipple 5. Are opposed to each other in a state of contacting or approaching.
Further, between the two valleys 42a of the flexible tube 4 and the inner peripheral surface 5b of the rotating nipple 5 in the region covered with the rotating nipple 5, a seal ring 10 made of rubber or the like for sealing between them, 10 is fitted, and the valley 42a between which the seal ring 10 is further fitted is formed between the valley 42b on the tip side of the valley 42a into which the seal rings 10 and 10 are fitted and the inner peripheral surface 5b of the rotary nipple 5. Centering rings 20 and 20 for securing the sealing performance by the pressure contact of the seal ring 10 are fitted between the valley portion 42c on the rear side and the inner peripheral surface 5b of the rotary nipple 5, respectively.

  Next, an example of a procedure for inserting and fixing the flexible tube 4 inside the rotating nipple 5 will be described below. In the present embodiment, the front expanded diameter crests 43a and 43b are formed in two.

<2-1. Configuration of the front diameter-expanded peak portion 43 of the flexible tube 4>
First, a lubricant such as silicon grease is applied to the inner peripheral surface 5 b of the rotating nipple 5, and the distal end side of the flexible tube 4 is inserted into the rotating nipple 5. At this time, the peak portions 41a and 41b on the distal end side of the flexible tube 4 are protruded from the distal end port 51a of the rotary nipple 5 to the extent that the forward enlarged peak portions 43a and 43b can be formed later.
Thereafter, the crests 41a and 41b on the distal end side of the flexible tube 4 projecting from the distal end port 51a of the inner diameter part 53 of the rotating nipple 5 are arranged on the opposed inner peripheral surfaces of the crests 41a and 41b and the crests 41a and 41b. It crushes with the crushing tool which is not illustrated in the axial direction L back side with respect to 5 d of front-end | tip surfaces of the rotation nipple 5 until it mutually contact | abuts or closely_contact | adheres.
At this time, the crest portions 41a and 41b on the distal end side of the flexible tube 4 crushed in the axial direction L rear side are larger than the inner diameter of the rotating nipple 5 and smaller than the distal end trough diameter of the male screw portion 52 of the rotating nipple 5. It is formed in the front enlarged crest parts 43a and 43b of the outer diameter.
Even after the formation of the front enlarged diameter crests 43a and 43b, it is preferable to keep the state in contact with or close to the front end surface 5d of the rotary nipple 5, but the state is not necessarily maintained. It is not essential to continue.

With the above configuration, the flexible tube 4 can be prevented from moving backward from the rotating nipple 5 in the axial direction L without using welding or other members.
And the sealing performance by the seal ring 10 between the flexible pipe 4 and the rotary nipple 5 and the prevention from the rotary nipple 5 can be secured by using the peak portions 41a and the valley portions 42a.
Therefore, conventional sleeves and welding are not required, the number of members can be reduced, the manufacturing time can be shortened, and the cost can be reduced, and fluid leakage can be easily prevented.

Note that the maximum outer diameter of the front enlarged ridge portions 43a and 43b is formed to be larger than the inner diameter of the inner diameter portion 53 of the rotating nipple 5 and smaller than the tip trough diameter (minimum outer diameter) of the male screw portion 52 of the rotating nipple 5. Keep it. By doing so, it may be an obstacle to screw the male threaded portion 52 of the rotating nipple 5 into the female threaded portion Y on the inner peripheral surface of the connecting portion X provided on the connection target shown in FIG. Absent.
Further, the male threaded portion 52 of the rotating nipple 5 is screwed and connected to the female threaded portion Y of the connecting portion X provided for connection, and the front end surface 5d of the male threaded portion 52 of the rotating nipple 5 is opposed to the front end surface 5d. It is possible to employ a structure in which the front diameter-expanded crests 43a and 43b are tightly connected to the receiving surface Z behind the female thread Y to be connected. With this tightly attached structure, fluid leakage in the flexible tube 4 can be effectively prevented at the tightly attached portion, and the flexible tube 4 is not easily pulled out even if a strong pulling force acts on the flexible tube 4 and is flexible. The pull-out prevention force of the pipe can be greatly improved.
In addition, when the said front diameter expansion peak part is only the front diameter expansion peak part 43a, only this front diameter expansion peak part 43a is closely attached between the front end surface 5d of the rotation nipple 5, and the receiving surface Z of a connection object. As a result, the fluid leakage effect in the flexible tube 4 and the effect of the pull-out preventing force of the flexible tube 4 are exhibited.

<2-2. Configuration of Seal Ring 10 and Alignment Ring 20>
Next, the seal ring 10 and the alignment ring 20 in the present embodiment will be described with reference to FIG.

First, the seal ring 10 in this embodiment will be described.
A seal ring 10 for sealing and sealing between the valley 42a of the flexible tube 4 and the inner peripheral surface 5b of the rotary nipple 5 in a region covered with the rotary nipple 5 is fitted.
In the present embodiment, as shown in FIG. 2, a certain valley 42 a in the tip side region of the flexible tube 4 covered with the rotating nipple 5 and one mountain from the valley 42 a are located behind the flexible tube 4. Seal rings 10 and 10 are respectively fitted between one trough portion 42 a on the side and the inner peripheral surface 5 b of the rotating nipple 5.
The material of the seal ring 10 is made of rubber, synthetic resin, expanded graphite or the like having a sealing function.

  In the present embodiment, the seal ring 10 is fitted into another valley 42a placed one mountain, but the seal ring 10 may be fitted into another valley 42a located two or more mountains.

Next, the alignment ring 20 in this embodiment will be described.
Between the troughs 42a and 42a into which the seal rings 10 and 10 are fitted, and between the troughs 42b on the tip side of the troughs 42a and 42a and the inner peripheral surface 5b of the rotary nipple 5, and further from the troughs 42a and 42a into which the seal rings 10 and 10 are fitted. Centering rings 20 and 20 for securing the sealing performance by the pressure contact of the seal ring 10 are fitted between the rear valley 42c and the inner peripheral surface 5b of the rotary nipple 5, respectively.
The material of the alignment ring 20 is made of resin or metal.
The shape of the alignment ring 20 is formed in a notch shape in which a part of each circumference is cut. As shown in FIG. 2, the outer peripheral surfaces of the alignment rings 20, 20 are planar along the inner peripheral surface 5 b of the rotating nipple 5 so that the contact area with the inner peripheral surface 5 b of the rotating nipple 5 increases. Is formed. In addition, the outer peripheral surfaces of the alignment rings 20 and 20 may be formed in a state where the outer periphery is rounded (arc state). Since the outer periphery of the outer peripheral surface of the alignment rings 20 and 20 is rounded in this manner, the outer periphery of the alignment rings 20 and 20 is in line contact with the inner periphery of the rotating nipple 5. The flexible tube 4 can be easily inserted into the nipple 5 and the assembly becomes easier. Furthermore, in order to obtain the same effect, the alignment rings 20 and 20 may be formed in a circular shape in a sectional view. Moreover, it is preferable that the inner peripheral surfaces of the alignment rings 20 and 20 are formed with curved surfaces along the valley shapes of the valley portions 42 a and 42 a of the flexible tube 4.

  After the seal rings 10 and 10 and the alignment rings 20 and 20 are attached to the flexible tube 4 as described above, silicon grease or the like is provided on the outer peripheral surfaces of the seal rings 10 and 10 and the alignment rings 20 and 20. The rotation nipple 5 is easily rotated by applying the lubricant.

  With such a configuration, even if an internal force due to fluid pressure of the flexible tube 4 or an external force from the outside acts on the flexible tube 4, the rotating nipple 5 and the flexible tube 4 are sealed by the alignment rings 20 and 20. A large shift of the shaft center is prevented at the place where the rings 10 and 10 are fitted, and the seal rings 10 and 10 can be satisfactorily pressed against the flexible tube 4 and the rotating nipple 5 over the entire circumference, so that fluid leaks in the flexible tube 4. Can be effectively prevented.

<3. Other configurations>
As mentioned above, although one Embodiment of this invention was described, the specific structure of each part is not limited only to embodiment mentioned above, A various change is possible in the range which does not deviate from the meaning of this invention.

<3-1. Configuration of Backward Expanded Mountain 44 of Flexible Tube 4>
For example, as a mode for restricting or suppressing the axial rearward movement of the rotating nipple 5, the rear end port 53 a of the inner diameter portion 53 of the rotating nipple 5 expands radially outward from the inner diameter of the inner diameter portion 53. The enlarged rear end port 53b is formed, and the crest portion 41 of the flexible tube 4 at the position corresponding to the enlarged rear end port 53b is crushed in the axial direction L so that a gap remains between the opposing inner peripheral surfaces ( Alternatively, although not shown, a rear enlarged crest 44 having an outer diameter larger than the inner diameter of the inner diameter portion 53 of the rotary nipple 5 is formed by crushing in the axial direction L so that no gap remains between the opposed inner peripheral surfaces. A configuration in which the rear diameter-expanded peak portion 44 is inserted into the enlarged rear end port 53b can be employed.
By adopting such a configuration, it is possible to prevent the rotating nipple 5 from unintentionally shifting from the distal end side region of the flexible tube 4 to the rear in the axial direction L.

In the above embodiment, the peak portion 41 of the flexible tube 4 at the position corresponding to the enlarged rear end port 53b is crushed in the axial direction L to form the rear diameter enlarged mountain portion 44, but the position corresponding to the enlarged rear end port 53b. The two or more ridges 41, 41,... Of the flexible tube 4 may be crushed in the axial direction L so as to be formed into the rear diameter enlarged ridges 44, 44,.
By doing so, it is possible to further prevent the rotating nipple 5 from moving unintentionally from the distal end region of the flexible tube 4 to the rear in the axial direction L.

  At this time, the boundary portion 54 of the rotating nipple 5 and the rear side of the flexible tube 4 are in a state where the rear surface side 43c of the front enlarged crest portion 43a is opposed to and brought into contact with the front end surface 5d of the rotating nipple 5. By forming a slight gap s between the expanded ridge 44, the flexible tube 4 slightly extends and moves in the axial direction L due to the internal fluid pressure (or internal powder pressure). Can be configured.

  Moreover, in this embodiment, although the peak parts 41a and 41b by the side of the front-end | tip part of the flexible tube 4 were crushed in the axial direction L, the front diameter expansion peak parts 43a and 43b were comprised, The front diameter-expanded peak portion 43a may be constituted by only one 41a, or the front diameter-expanded peak portion may be constituted by three or more peak portions on the tip side.

  Further, the rotating nipple 5 may be configured to be fitted not only to the front end portion in the axial direction L of the flexible tube 4 but also to the rear end portion.

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Metal flexible pipe 4 Flexible pipe 41 Peak part 41a Peak part 42a Peak part 42 Valley part 42a Tip part side valley part 43a Front diameter expansion peak part 43c Rear surface side 44 Back diameter expansion peak part 5 Rotating nipple 51 Tip part 51a front end port 5a outer peripheral surface 52 male threaded portion 53 inner diameter portion 53a rear end port 5b radial inner peripheral surface 53b enlarged rear end port 5c radial inner peripheral surface 54 boundary portion 5d front end surface 10 seal ring 20 alignment ring L axial direction X connection portion Y Female thread part Z Reception surface

Claims (3)

A rotating nipple is fitted on at least the tip of the flexible tube,
A male screw is provided on the outer peripheral surface of the tip of the rotating nipple,
A crest on the distal end side of the flexible tube is crushed in the axial direction and formed into a front expanded crest having an outer diameter larger than the inner diameter of the rotating nipple and smaller than the tip trough diameter of the male thread of the rotating nipple. And the rear surface side of the front expanded ridge is opposed to the tip surface of the rotating nipple,
Between the trough of the flexible tube in the region covered with the rotating nipple and the inner peripheral surface of the rotating nipple, a seal ring that seals between them is fitted,
Between the trough on the tip side of the trough where the seal ring is fitted and the inner peripheral surface of the rotating nipple, and further on the rear side of the trough where the seal ring is fitted and the inner circumference of the rotating nipple A metal flexible tube characterized in that a centering ring for securing sealing performance by press-contacting the seal ring is fitted between each surface. An enlarged rear end port that expands radially outward is formed at the rear end port of the inner diameter portion of the rotating nipple,
The crest portion of the flexible tube at the position corresponding to the enlarged rear end port is crushed in the axial direction to form a rear enlarged crest portion having an outer diameter larger than the inner diameter of the inner diameter portion of the rotating nipple. The metal flexible tube according to claim 1, wherein a portion is inserted into the enlarged rear end opening.    3. The metal flexible tube according to claim 1, wherein the front diameter-expanded crest portion is configured by crushing a crest portion on a distal end side of the flexible tube in a plurality of axial directions.

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