JP2005325934A - Terminal structure of flexible metal hose - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an easily manufacturable flexible metal hose having a simple configuration and capable of being supplied at comparatively low cost and holding leakage stop effect for a long time. <P>SOLUTION: This terminal structure of the flexible metal hose includes a pressing nut 4 allowing a corrugated metal tube 1 to be inserted and a coupling 3 in which the pressing nut 4 is screwed while the metal tube 1 is inserted. A tip part of the metal tube 1 is pressed against a sealing member 10 arranged in the coupling 3 in accordance with screwing of the pressing nut 4 into the coupling 3 to achieve sealing of its part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a flexible metal hose terminal structure, more specifically, a simple structure of a flexible metal hose composed of a wave-processed metal tube that feeds pressure fluid such as water, oil, gas, air, and steam. It relates to the terminal structure.

  In general, a flexible metal hose is usually made of a stainless steel metal tube with a uniform wave formed on the metal tube. When the fluid to be fed is at a very high pressure, a braid consisting of many wires braided on the metal tube. However, the object of the present invention is a type that does not cover this blade.

  Joint means for connecting to other pipes are installed at both ends of the metal tube. The terminal structure of the conventional flexible metal hose for installing the joint means can be roughly classified into a weld type and a non-weld type.

  The hose terminal structure shown in FIGS. 4 and 5 is a welding type. In FIG. 4, a joint 53 fitted into a loose flange 54 is fitted to the end of the metal tube 51. In this case, the long-formed metal tube 51 with the blade 52 is cut to a desired length and welded from the cut end of the metal tube 51 to the blade 52 and the joint 53 (welded portion 55).

  The hose terminal structure shown in FIG. 5 has a blade retainer 56 fitted to the end of a tube 51 with a blade 52 sheathed, and a sleeve 58 with a slide nut 57 engaged with the end surface of the metal tube 51. It is. In this case, first, the separated end portion of the metal tube 51 cut to a desired length, the blade 52 and the blade retainer 56 are welded (welded portion 59), and then the sleeve 58 is welded to the welded portion 59 (see FIG. Weld 60).

  In the case of these welding methods, the metal tube 51 is manually welded in an annular shape along the cut end. However, since the welded portion is heated, the surface of the metal tube 51 is easily oxidized and oxidized. As a result, the corrosion resistance is reduced.

  In addition, the flexibility of the metal tube is given by the change in the radius of curvature of the corrugation, but when the influence of heating is large, the metal structure near the welded joint of the metal tube changes and the change in the radius of curvature, that is, The bending resistance is significantly reduced. In particular, in the case of the hose end structure shown in FIG. 5, the influence of heating is greatly affected because the welding operation must be performed twice.

On the other hand, the non-welding type hose terminal structure not based on welding is to fix the ends of the metal tube 51 and the blade 52 to a nut or the like by a method such as caulking or clamping.
6 is one in which a fixing pipe 61 is fixed by caulking and a connecting pipe 62 is connected (Japanese Patent Laid-Open No. 2000-220781).

  In this case, a fixing fitting 61 having a concave groove 63 formed on the outer peripheral surface is inserted between the blade 52 and the metal tube 51, and a fixing ring 64 is fitted into the concave groove 63 from above the blade 52. The end of 52 is fixed. The metal tube 51 is inserted into the connection pipe 62 after performing a secondary process of extending the waved end portion into a straight pipe 51a. Then, the insertion end portion of the connecting pipe 62 in the fixing bracket 61 is flared, and the O-ring 66 fitted in the fixing bracket 61 abuts on the flare portion 65. By coming into contact with the wave 67 on the front end side, fluid leakage at that portion is prevented.

  In the case of this structure, not only is it difficult to manage the manufacturing dimensional accuracy, but also the problem that it takes time and cost for manufacturing because it is necessary to stretch the wave once formed, flaring the connecting pipe 62, and the like. .

  In the case shown in FIG. 7, a metal tube 51 having a wave extending process and flaring processed at the tip is prepared in the same manner as described above, and a base ring 70 is provided between the straight pipe part 51 a and the blade 52. And the end of the blade 52 is clamped by fitting the press ring 71 to the base ring 70 (Japanese Patent Laid-Open No. 2004-76885).

  Further, a joint pipe member 74 having a tapered wall 73 corresponding to the inclination of the flare portion 72 of the metal tube 51 is prepared on the inner periphery, and the tapered wall 73 is provided via a flare extension portion 75 extending to the base ring 70. In order to hold down the flare 72, it is said that sufficient tensile strength in the axial direction can be obtained. However, even in this structure, it is necessary to stretch the wave and flare the tip. As in the case described above, there are drawbacks in that it takes time and effort to manufacture.

  All of the conventional techniques described above are of the type with a blade, but the same can be said for the type without a blade.

JP 2000-220781 A JP 2004-76885 A

  Since the conventional flexible metal hose terminal structure has the above-mentioned problems, the present invention does not have such a problem, that is, it is easy to manufacture and can be supplied at a relatively low cost, and it also prevents leakage for a long time. It aims at providing the terminal structure of the flexible metal hose which can hold | maintain an effect.

  The present invention includes a press nut into which a wave-processed metal tube is inserted, and a coupling into which the press nut is screwed in a state in which the metal tube is inserted, and the press nut is screwed into the coupling. The end of the metal tube is pressed against a seal member provided in the coupling, and the sealing of that portion is achieved. .

  Preferably, pressing of the distal end portion of the metal tube against the seal member by the retaining nut is performed through a retaining ring installed at the distal end portion of the metal tube. In that case, the pressing ring is fitted so that a part thereof protrudes into the trough at the end of the metal tube, and the end side surface of the pressing nut in the coupling protrudes from the trough of the pressing ring. It is preferable that the contact can be made.

  The seal member is an O-ring or a hard packing. In the case of an O-ring, it is installed by being fitted into an annular O-ring fitting groove formed in the middle part of the coupling, and the inner bottom of the O-ring fitting groove is a shallow inclined surface on the outer peripheral side and deep on the inner peripheral side In addition, it is preferable to provide stopper means for restricting the entry end of the presser nut in the coupling.

  The terminal structure of the flexible metal hose according to the present invention does not require time-consuming secondary processing of the metal tube and the like, and thus can be easily manufactured, thereby reducing the cost. The final assembly can be done simply by screwing the holding nut into the coupling and screwing the connecting parts into the coupling. In addition, as the holding nut is screwed in, the separated end of the metal tube is crushed. Since it is in close contact with the seal member, there is an effect that at the same time, a seal for preventing leakage and a firm fixation of the metal hose are achieved.

  Further, in the terminal structure according to the present invention, leakage prevention is performed by pressing the separated end of the metal tube against the seal member. However, in the case of an O-ring, it is stored in the O-ring fitting groove of the coupling. And, since the ingress end of the presser nut in the coupling is restricted, the deformation is limited to a certain range, so that the resilience of the rubber is not impaired, and thus the leakage preventing effect is maintained for a long time. .

  Particularly, in the invention described in claim 6, since the O-ring does not escape at the time of pressure reception, there is an effect that a better and sufficient sealing performance can be obtained.

  The best mode for carrying out the present invention will be described with reference to the accompanying drawings. FIG.1 and FIG.2 is a fragmentary sectional view which shows an example of the terminal structure of the flexible metal hose which concerns on this invention. The flexible metal hose in this embodiment is composed of a metal tube 1 in which waves are formed as in the conventional one. In the illustrated example, the end has a structure including a presser nut 4 to be screwed into the coupling 3.

  One half (right half in the figure) of the coupling 3 is a reduced diameter part 5 having an inner diameter corresponding to the inner diameter of the metal tube 1, and the other half (left half in the figure) is more than the metal tube 1. The enlarged-diameter portion 6 has a large inner diameter. A male screw portion 7 is formed on the outer peripheral surface of the reduced diameter portion 5, and a female screw portion 8 is formed on the inner peripheral surface of the enlarged diameter portion 6.

  The reduced diameter portion 5 extends to substantially the middle position inside the coupling 3, and an annular O-ring fitting groove 9 is formed so as to surround the projecting inner end edge 18, and the O-ring 10 is fitted therein. It is. Usually, when the O-ring 10 is fitted in the O-ring fitting groove 9, the inner end edge 18 protrudes from the O-ring 10.

  Preferably, the inner bottom 11 of the O-ring fitting groove 9 is a tapered surface having a shallow outer peripheral side and a deep inner peripheral side. As will be described later, this configuration prevents the O-ring 10 from escaping to the outer peripheral side when the O-ring 10 is pressed, and acts so that the sealing performance with the end of the metal tube 1 does not deteriorate. Further, a stepped portion 19 that functions as a stopper of the presser nut 4 is formed on the inner peripheral surface of the enlarged diameter portion 6.

  The presser nut 4 has a male screw cylinder 13 formed with a male screw to be engaged with the female screw 8 of the coupling 3, and after inserting the end of the metal tube 1, the male screw cylinder 13 is connected to the female screw part 8 of the coupling 3. Screw it in. The metal tube 1 is simply cut out to a desired length, and it is not necessary to perform a special secondary process thereafter.

  A pressing ring 15 is fitted into the trough 16 at the tip of the metal tube 1. The holding ring 15 is a C-shaped ring that is cut off at one point and the cut-off portion can be opened or closed, or a divided ring that is combined into a circular shape. The upper part of the pressing ring 15 protrudes from the valley 16, and the end surface 4 a of the pressing nut 4 comes into contact with the upper part of the pressing ring 15 protruding from the valley 16 as the pressing nut 4 is screwed into the coupling 3. To be done.

  In order to configure this terminal structure, first, the end portion of the metal tube 1 cut out to a desired length is inserted into the holding nut 4, and the holding ring 15 is fitted into the trough 16 at the distal end portion that protrudes to the opposite side. In this state, the holding nut 4 is shifted to the coupling 3 side, and the male screw cylinder 13 is screwed into the female screw portion 8 of the coupling 3.

  When the presser nut 4 is screwed in this way, the end face 4a eventually hits the upper part of the presser ring 15 protruding from the trough 16, and the presser ring 15 is pushed in as it is further screwed.

  Then, when the separation end 17 of the metal tube 1 first hits the inner end edge 18 of the reduced diameter portion 5 (FIG. 1), and the presser nut 4 is further screwed, the wave at the tip is caused by the inner end edge 18 and the presser ring 15. It is sandwiched between and gradually crushed. That is, the back of the wave at the tip is pressed by the presser ring 15, and the presser ring 15 is pressed against the end surface 4 a of the presser nut 4. The inner end edge 18 and the pressing ring 15 are pressed and crushed. At that time, since the separation end 17 hits the inner end edge 18 and is pressed, the crushed wave is inclined, and the upper part thereof is in close contact with the O-ring 10 (state of FIG. 2). In this way, the upper part of the wave keeps in close contact with the O-ring 10, so that the part can be continuously sealed.

  At that time, the O-ring 10 is also pressurized and deformed, but the O-ring 10 is housed in the fitting groove 9, and the holding nut 4 is screwed until its end face 4a hits the step portion 19, and beyond that, Since it does not advance, the pressurization with respect to the O-ring 10 stops in a predetermined range. Therefore, the deformation of the O-ring 10 is within a certain range, and the resilience elasticity is not impaired by excessive pressurization, and the leak-proof function is maintained for a long time. When the inner bottom surface 11 of the O-ring fitting groove 9 is inclined, the O-ring 10 is prevented from escaping outward during pressure reception, and the sealing performance is prevented from being deteriorated.

  In the above assembling work, the metal tube 1 is simply cut, and there is no need for secondary processing such as stretching or flaring. Even after assembly, the presser nut 4 is simply screwed into the coupling 3. It is easy to perform, and at the same time, the sealing by the O-ring 10 is achieved with the screwing operation.

  The embodiment shown in FIG. 3 uses an annular hard packing 20 instead of the O-ring 10 in the above-described embodiment. The hard packing 20 includes metallic packing such as cast iron, bronze, white metal, and carbon, and semi-metallic packing made by combining a metal material and a non-metal material. In this case, a recess 9 a for embedding a part or the whole of the hard packing 20 may be provided in the coupling 3, but the inner peripheral side of the recess 9 a is not projected like the inner end edge 18. Further, when the presser nut 4 is tightened, the end surface 4 a is separated so as not to hit the stepped portion in the enlarged diameter portion 6.

  In the case of this embodiment, there is basically no difference from the operational effects and the assembly method of the above embodiment, except that the wave at the tip hits the hard packing 20 and is crushed to maintain the close contact state.

  Although the present invention has been described in some detail with respect to its most preferred embodiments, it will be apparent that a wide variety of embodiments can be constructed without departing from the spirit and scope of the invention, the invention being defined by the appended claims. It is not restricted to the specific embodiment other than limiting in.

It is a fragmentary sectional view which shows the state before clamp nut tightening of one Embodiment of the terminal structure of the flexible metal hose which concerns on this invention. It is a fragmentary sectional view showing the state after tightening the holding nut of one embodiment of the terminal structure of the flexible metal hose concerning the present invention. It is a fragmentary sectional view which shows the state after clamp | tightening the holding nut of other embodiment of the terminal structure of the flexible metal hose which concerns on this invention. It is a fragmentary sectional view which shows one structural example of the terminal structure of the flexible metal hose by the conventional welding method. It is a fragmentary sectional view which shows the other structural example of the terminal structure of the flexible metal hose by the conventional welding method. It is a fragmentary sectional view which shows one structural example of the terminal structure of the flexible metal hose by the conventional non-welding method. It is a fragmentary sectional view which shows the other structural example of the terminal structure of the flexible metal hose by the conventional non-welding method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal tube 3 Coupling 4 Retaining nut 4a End surface of retaining nut 5 Reduced diameter part 6 Expanded part 7 Male thread part 8 Female thread part 9 O-ring fitting groove 9a Recessed part 10 O-ring 11 Inner bottom of fitting groove 13 Male screw cylinder 15 Presser ring 16 Valley 17 Cut end 18 Inner end edge 19 Step 20 Hard packing

Claims (8)

  A holding nut into which a wave-processed metal tube is inserted; and a coupling into which the holding nut is screwed in a state in which the metal tube is inserted. The flexible metal hose terminal structure is characterized in that the tip of the tube is pressed against a seal member provided in the coupling to thereby seal the portion.   The terminal structure of a flexible metal hose according to claim 1, wherein the pressing nut is pressed against the seal member at the tip of the metal tube via a pressing ring installed at the tip of the metal tube.   The presser ring is fitted so that a part thereof protrudes into a trough at the end of the metal tube, and the end surface on the entry side of the presser nut abuts on a part protruding from the trough of the presser ring. The terminal structure of the flexible metal hose according to claim 2, which is made possible.   The terminal structure of a flexible metal hose according to claim 1, wherein the seal member is an O-ring.   The terminal structure of a flexible metal hose according to claim 4, wherein the O-ring is installed by being fitted into an annular O-ring fitting groove formed in an intermediate portion in the coupling.   The terminal structure of a flexible metal hose according to claim 5, wherein the inner bottom of the O-ring fitting groove is an inclined surface having a shallow outer peripheral side and a deep inner peripheral side.   The terminal structure of the flexible metal hose according to any one of claims 4 to 6, wherein stopper means for restricting an entry end of the presser nut is provided in the coupling.   The terminal structure of a flexible metal hose according to claim 1, wherein the seal member is a hard packing.

Images