JP2005282724A - Metal bellows pipe joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable the securing of a predetermined inserting quantity of a metal bellows pipe by making such a structure that the inserting feeling can be obtained at the completion of inserting the metal bellows pipe, eliminating the need for marking, and to solve the problem that inserting is insufficient, even in a narrow place, a closed place, a dark place, etc. <P>SOLUTION: A snap ring 5 having an outside diameter which is greater than a root inside diameter and smaller than a height inside diameter of the metal bellows pipe 7 is fitted into a deeper position than a seal packing 3 on the circumference of an inner cylinder 10 of a pipe joint body 1. An inserting resistance value for inserting the metal bellows pipe 7 into the snap ring 5 is set greater than an inserting resistance value for inserting it into an annular holder 4. An exposed end 7a of the metal bellows pipe 7 is inserted into a push ring 2, the annular holder 4, and a seal packing 3 successively. Reaching the snap ring 5, the inserting resistance becomes a maximum when the endmost root of the exposed end 7a of the metal bellows pipe 7 exceeds the snap ring 5, and the predetermined inserting quantity can be confirmed to obtain by the inserting feeling directly after going beyond there. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pipe joint for a metal bellows pipe connected to an outdoor gas appliance or the like.

  For example, a conventional metal bellows pipe joint has a structure as shown in FIG. There, a joint main body 33 having a receiving portion 32 composed of inner and outer double cylindrical portions 30 and 31 at one end, a push ring 35 screwed into a female screw 34 provided on the inner periphery of the outer cylindrical portion 31, and an outer cylindrical portion 31 An annular seal packing 36 fitted inside and an annular holder 37 made of metal that can be expanded and contracted are provided. Thus, the exposed end portion 7a from which the resin coating 6 of the metal bellows tube 7 having the resin coating 6 applied on the outer surface is peeled off is inserted into the pusher wheel 35 as shown in FIG. The seal packing 36 is inserted between each inner periphery and the outer periphery of the inner cylinder part 30. The annular holder 37 is used to prevent the metal bellows tube 7 from being inserted, and the minimum inner diameter portion of the annular holder 37 is smaller than the outer diameter of the mountain portion of the metal bellows tube 7 and smaller than the outer diameter of the valley portion. The metal bellows tube 7 can be prevented from coming off by being set large and maintaining the engagement state in a certain valley after the metal bellows tube 7 is inserted.

  However, in the metal bellows pipe joint, when the exposed end 7a of the metal bellows pipe 7 is inserted, the seal packing 36 is passed after passing through the annular holder 37. Since the resistance when the metal bellows tube 7 passes through the annular holder 37 is larger than the resistance when the tube 7 passes through the seal packing 36, the insertion is completed after the metal bellows tube 7 passes through the annular holder 37. However, the sense of insertion is obtained, and it is difficult to judge when the insertion is completed. Therefore, it is unavoidable that the metal bellows tube 7 is marked by marking (not shown). However, since visual confirmation of the marking is very difficult in a narrow working place, closed place, dark place, etc., the metal bellows tube 7 is insufficiently inserted and the metal bellows tube in the joint body 1 due to insufficient insertion. Anxiety remains in the long-term airtightness by the seal packing 36 between the seven.

  Accordingly, an object of the present invention was made to solve such problems, and by making efforts to obtain a reliable insertion feeling when the insertion of the metal bellows tube is completed, a marking-less configuration can be achieved. An object of the present invention is to provide a metal bellows pipe joint that can solve the problem of insufficient insertion even in a closed place, a dark place, and the like.

  The metal bellows pipe joint according to the present invention includes a joint main body having a receiving portion made of an inner and outer double tube portion at one end, a push ring screwed into a female screw provided on the inner periphery of the outer tube portion, and the outer tube portion. And an annular seal packing fitted inside and an annular holder that can be expanded and contracted, and an exposed end portion of a metal bellows tube having a resin coating on the outer surface is inserted into the push ring, Further, the seal packing and the annular holder are inserted between the inner circumference and the outer circumference of the inner cylinder portion, and the smallest inner diameter portion of the annular holder is the outer diameter of the crest of the metal bellows tube It is set smaller than the outer diameter of the valley.

  In addition, the present invention provides a snap ring having an outer diameter larger than the inner diameter of the valley portion of the metal bellows tube and smaller than the inner diameter of the peak portion, and having a pipe insertion guide taper at one end of the outer diameter portion. The insertion resistance value of the metal bellows tube is inserted into the inner ring portion of the seal packing on the outer peripheral surface, and the insertion resistance value of the metal bellows tube to the annular holder is larger than the insertion resistance value of the metal bellows tube to the annular holder. It is characterized by being set large.

  When the snap ring is fitted in the inner part of the outer peripheral surface of the inner cylinder portion in this way, the exposed end portion of the metal bellows tube is sequentially inserted into the push ring, the annular holder and the seal packing to reach the snap ring. When the most advanced valley of the exposed end of the metal bellows gets over the snap ring, the insertion resistance is maximized and the response is maximized. It is done. That is, the insertion of the metal bellows tube is completed by the insertion feeling obtained immediately after the most advanced valley of the exposed end portion of the metal bellows tube gets over the snap ring, and a predetermined insertion amount is obtained by the insertion feeling at this time. Can be confirmed. Also, the exposed end of the metal bellows tube can be easily inserted by hand.

  Further, the present invention provides a snap ring having an inner diameter that is smaller than the outer diameter of the peak portion of the metal bellows tube and larger than the outer diameter of the valley portion, and has a taper for pipe insertion guide at one end of the inner diameter portion. The insertion resistance value of the metal bellows tube is inserted into the snap ring so as to be located at a deeper position than the seal packing on the inner peripheral surface, and the insertion resistance value of the metal bellows tube to the annular holder is smaller than the insertion resistance value of the metal bellows tube It is characterized by being set large.

  When the snap ring is fitted in the inner part of the inner peripheral surface of the receiving portion in this way, the exposed end of the metal bellows tube is sequentially inserted into the press ring, the annular holder, and the seal packing, so that the snap ring When the leading edge of the exposed end of the metal bellows tube gets over this snap ring, the insertion resistance is maximized and there is a response, and when it gets over the snap ring, there is a certain insertion feeling, that is, a click feeling can get. As described above, the insertion is stopped immediately after the metal bellows tube is completely inserted. At this stage, it can be confirmed that a predetermined insertion amount of the metal bellows tube has been obtained. Also, the exposed end of the metal bellows tube can be easily inserted by hand.

  Furthermore, the present invention is arranged such that the annular holder is located inward of the seal packing, and the insertion resistance value of the metal bellows tube to the annular holder is the insertion resistance of the metal bellows tube to the seal packing. It is characterized by being set larger than the value.

  According to this, when the exposed end of the metal bellows tube is sequentially inserted into the press ring and the seal packing and reaches the annular holder, the leading edge of the exposed end of the metal bellows tube passes through this annular holder. However, the insertion resistance at the time of passing is greater than the resistance at the time of passing the seal packing, and there is a response, and the insertion is stopped immediately after this response. That is, it can be confirmed that the predetermined insertion amount is obtained immediately after the completion of the insertion of the metal bellows tube. Also, the exposed end of the metal bellows tube can be easily inserted by hand.

  According to the metal bellows pipe joint of the present invention, since the insertion of the metal bellows pipe is structured to obtain a reliable insertion feeling, a predetermined insertion amount of the metal bellows pipe can be ensured, and marking-free can be achieved. Even in narrow places, closed places, dark places, etc., the problem of insufficient insertion can be solved and the safety can be improved.

  Hereinafter, a preferred embodiment of a metal bellows joint according to the present invention will be described.

(First embodiment)
A first embodiment of a metal bellows joint according to the present invention will be described with reference to FIGS. As shown in FIG. 1, the metal bellows pipe joint includes a joint body 1, a push ring 2, a seal packing 3, an annular holder 4, and a snap ring 5.

  The joint body 1 is provided at one end thereof with a receiving portion 8 for receiving the exposed end portion 7a from which the resin coating 6 of the metal bellows tube 7 whose outer surface is coated with the resin coating 6 is peeled off. A male screw 9 to which other riser pipe joints and the like are connected is provided on the outer periphery. The receiving portion 8 is composed of inner and outer double tube portions 10 and 11, and the outer tube portion 11 is formed to protrude longer than the inner tube portion 10, and a female screw 12 is provided on the inner periphery of the opening end.

  The pusher wheel 2 is provided with a male screw 13 that is screwed into the female screw 12 of the joint body 1 on the outer periphery of the tip thereof, and an annular groove 14 is provided on the inner periphery of the pusher wheel 2. The annular groove 14 has a T-shaped cross section. The waterproof packing 15 is fitted. When the presser wheel 2 is screwed into the female thread 12 of the joint body 1, a resin ring sheet 25 is provided between the opening end surface of the outer cylinder portion 11 of the joint body 1 and the end surface of the flange portion 2 a of the presser wheel 2 facing the end surface. Intervene.

  The seal packing 3 is formed in an annular shape by NBR or the like, and a refractory part 3a made of thermally expandable graphite or the like is integrally formed at one end thereof. The seal packing 3 has an inner diameter smaller than the outer diameter of the peak portion of the metal bellows tube 7 and is fitted into the outer cylinder portion 11 of the joint body 1 so that the refractory portion 3a is on the inner back side.

  As shown in FIG. 3, the annular holder 4 has slits 29 at predetermined intervals in the circumferential direction in the metal ring to divide the metal ring into several parts, and into grooves 16 provided on the outer periphery of each divided body 4a. The elastic ring 17 made of a coil spring or the like of about 1.5 turns is fitted so that it can be expanded and contracted. The annular holder 4 is provided with a tube insertion guide taper 18 on the inner periphery of the opening at one end, and the minimum inner diameter portion of the annular holder 4 is set smaller than the outer diameter of the peak of the metal bellows tube 7 and larger than the outer diameter of the valley. doing. As shown in FIG. 1, the annular holder 4 is fitted into the outer cylinder portion 11 so as to be positioned between the distal end portion of the presser wheel 2 and the seal packing 3 in the joint body 1.

  As shown in FIG. 4, the snap ring 5 is formed in a notch ring in which a part of the circumference of a metal ring such as SUS is cut off, and a pipe insertion guide taper 19 is attached to one end in the axial direction of the outer diameter portion. . The outer diameter of the snap ring 5 is set larger than the inner diameter of the valley of the metal bellows tube 7 and smaller than the inner diameter of the peak. As shown in FIG. 1, the snap ring 5 has a back-up ring 21 made of NBR or the like in an annular groove 20 provided in the inner back portion of the seal cylinder 3 on the outer peripheral surface of the inner cylinder portion 10 of the joint body 1. It is inserted through. The insertion resistance value of the metal bellows tube 7 to the snap ring 5 is set larger than the insertion resistance value of the metal bellows tube 7 to the annular holder 4.

  In the metal bellows pipe joint assembled as described above, the exposed end portion 7a of the metal bellows pipe 7 is provided inside the presser wheel 2, the inner circumference of the annular holder 4 and the seal packing 3, and the outer circumference of the inner cylinder part 10. However, when the snap ring 5 is reached, the insertion resistance is maximized when the most advanced trough 22 of the exposed end portion 7a of the metal bellows tube 7 gets over the snap ring 5. There is a response, and as shown in FIG. 2, it can be overcome, and at the same time, a certain insertion feeling, that is, a clicking feeling can be obtained. That is, immediately after the completion of the insertion of the metal bellows tube 7, the insertion is stopped, and it can be confirmed that a predetermined insertion amount of the metal bellows tube 7 is obtained at this time. Also, the exposed end of the metal bellows tube can be easily inserted by hand.

  When the insertion of the metal bellows tube 7 as shown in FIG. 2 is completed, the seal packing 3 ensures airtightness between the inner diameter portion of the outer cylinder portion 11 of the joint body 1 and the exposed end portion 7 a of the metal bellows tube 7. Is done. By maintaining the state in which the minimum inner diameter portion of the annular holder 4 is engaged with the outer diameter portion of a certain valley portion of the metal bellows tube 7, the metal bellows tube 7 is held in a retaining shape. The space between the resin coating 6 of the metal bellows tube 7 and the inner diameter portion of the push ring 2 is sealed with a waterproof packing 15 to prevent water from entering from the outside.

(Second embodiment)
Next, a second embodiment of the metal bellows joint will be described with reference to FIGS. In this embodiment, the snap ring 5 is formed in an NBR groove 28 provided in an inner back portion of the inner peripheral surface of the receiving portion 8 of the joint body 1, that is, on the inner peripheral surface of the outer cylinder portion 11, rather than the seal packing 3. It is inserted through a backup ring 20 made of or the like. The snap ring 5 has an inner diameter that is smaller than the outer diameter of the peak portion of the metal bellows tube 7 and larger than the outer diameter of the valley portion, and has a pipe insertion guide taper 23 at one end of the inner diameter portion. The insertion resistance value of the metal bellows tube 7 to the snap ring 5 is set larger than the insertion resistance value of the metal bellows tube 7 to the annular holder 4 of the metal bellows tube 7. In this embodiment, the receiving port 8 can be constituted only by the outer cylinder part 11, and the inner cylinder part 10 is not necessarily required. Other configurations are the same as those of the metal bellows joint of the first embodiment.

  Also in the metal bellows pipe joint of this embodiment, the exposed end portion 7a of the metal bellows pipe 7 has the push ring 2, the annular holder 4, the seal packing 3, and the snap ring 5 as in the case of the first embodiment. Inserted one after another, but after reaching the snap ring 5 and the most advanced peak 24 of the exposed end portion 7a of the metal bellows tube 7 getting over the snap ring 5, a certain insertion feeling, that is, a clicking feeling is obtained. It is done. That is, it can be confirmed that a predetermined insertion amount is obtained by obtaining an insertion feeling when the insertion of the metal bellows tube 7 is completed. Further, the exposed end portion 7a of the metal bellows tube 7 can be easily inserted by hand.

(Third embodiment)
7 and 8 show the metal bellows pipe joint of the third embodiment. In this embodiment, the snap ring 5 is not used as in the first and second embodiments. The annular holder 4 is arranged on the inner peripheral surface of the receiving portion 8, that is, the inner peripheral surface of the outer cylinder portion 11 so as to be located inward of the seal packing 3, and the metal bellows tube 7 is connected to the annular holder 4. The insertion resistance value is set larger than the insertion resistance value of the metal bellows tube 7 to the seal packing 3. When setting the insertion reduction values of the annular holder 4 and the seal packing 3, for example, in the case of the annular holder 4, the number of divisions, the wire diameter of the elastic ring 17 and the like are adjusted, and the hardness of the seal packing 3 is adjusted accordingly. Adjust the axial length. A metal-made retainer 26 having a triangular cross section is interposed between the annular holder 4 on the inner peripheral surface of the receiving port 8 and the seal packing 3. Further inside the annular holder 4 on the inner peripheral surface of the receiving port 8, a fireproof packing 27 formed of thermally expandable graphite or the like is disposed separately from the seal packing 3. In this embodiment, the receiving port portion 8 can be constituted only by the outer tube portion 11, and the inner tube portion 10 is not necessarily required. Other configurations are the same as those of the metal bellows joint of the first embodiment.

  According to the metal bellows pipe joint configured as described above, the exposed end portion 7 a of the metal bellows pipe 7 is sequentially inserted into the pusher wheel 2, the seal packing 3, and the annular holder 4. When it reaches, the leading edge 24 of the exposed end portion 7a of the metal bellows tube 7 gets over the annular holder 4, and the insertion resistance at this time is larger than the resistance when the seal packing 3 passes, so that the response is high. There is a certain insertion feeling, that is, a click feeling immediately after overcoming it. That is, it can be confirmed that the predetermined insertion amount is obtained by obtaining such an insertion feeling when the insertion of the metal bellows tube 7 is completed. Further, the exposed end portion 7a of the metal bellows tube 7 can be easily inserted by hand.

  Needless to say, the metal bellows pipe joint that is the subject of the present invention is not limited to the straight shape shown in the illustrated example, but can be applied to other shapes such as an elbow shape and a T shape. .

FIG. 2 is a half-broken cross-sectional view showing the metal bellows pipe joint of the first embodiment in a state before insertion of the metal bellows pipe. It is a half notched cross-sectional view showing the metal bellows pipe joint of the first embodiment in a state after the metal bellows pipe is inserted. It is a half notched cross-sectional view of the annular holder. It is a front view of a snap ring. It is a half notched cross-sectional view showing the metal bellows pipe joint of the second embodiment in a state before insertion of the metal bellows pipe. It is a half notched cross-sectional view showing the metal bellows pipe joint of the second embodiment in a state after the metal bellows pipe is inserted. It is a half notched cross-sectional view which shows the metal bellows pipe joint of 3rd Example in the state before metal bellows pipe insertion. It is a half notched cross-sectional view which shows the metal bellows pipe joint of 3rd Example in the state after metal bellows pipe insertion. FIG. 6 is a half-broken cross-sectional view showing a conventional metal bellows pipe joint in a state before insertion of the metal bellows pipe. FIG. 10 is a half-broken sectional view showing the metal bellows pipe joint of FIG. 9 in a state after the metal bellows pipe is inserted.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Joint main body 2 Push ring 3 Seal packing 4 Annular holder 5 Snap ring 6 Resin coating 7 Metal bellows tube 8 Receiving part 10 Inner cylinder part 11 Outer cylinder part 18 Taper for pipe insertion guide of annular holder 19 Pipe insertion guide of snap ring Taper

Claims (3)

A joint main body having a receiving portion made of an inner and outer double tube portion at one end, a push ring screwed into a female screw provided on the inner periphery of the outer tube portion, an annular seal packing and an expansion / contraction fit in the outer tube portion And an exposed end portion of a metal bellows tube having an outer surface coated with a resin film is inserted into the push ring, and each of the seal packing and the annular holder is further provided. It is designed to be inserted between the inner periphery and the outer periphery of the inner tube portion, and the minimum inner diameter portion of the annular holder is set smaller than the outer diameter of the peak portion of the metal bellows tube and larger than the outer diameter of the valley portion. Metal bellows pipe joints,
A snap ring having an outer diameter larger than the inner diameter of the valley portion of the metal bellows tube and smaller than the inner diameter of the peak portion, and having a pipe insertion guide taper at one end of the outer diameter portion, is formed on the outer peripheral surface of the inner cylinder portion. The insertion resistance value of the metal bellows tube is set to be larger than the insertion resistance value of the metal bellows tube into the annular holder. A metal bellows pipe joint. A joint body having a receiving portion at one end, a push ring screwed into a female screw provided on the inner periphery of the receiving portion, an annular seal packing fitted into the receiving portion, and an expandable / deformable annular holder; An exposed end portion of a metal bellows tube having an outer surface coated with a resin film is inserted into the push ring and further inserted into each of the seal packing and the annular holder. In the metal bellows pipe joint, the minimum inner diameter portion of the annular holder is set smaller than the outer diameter of the peak of the metal bellows pipe and larger than the outer diameter of the valley.
A snap ring having an inner diameter smaller than a crest outer diameter of the metal bellows pipe and larger than a trough outer diameter, and having a pipe insertion guide taper at one end of the inner diameter part, is formed on the inner peripheral surface of the receiving part. The insertion resistance value of the metal bellows pipe is set to be larger than the insertion resistance value of the metal bellows pipe to the annular holder. A metal bellows pipe joint. A joint body having a receiving portion at one end, a push ring screwed into a female screw provided on the inner periphery of the receiving portion, an annular seal packing fitted into the receiving portion, and an expandable / deformable annular holder; An exposed end portion of a metal bellows tube having an outer surface coated with a resin film is inserted into the push ring and further inserted into each of the seal packing and the annular holder. In the metal bellows pipe joint, the minimum inner diameter portion of the annular holder is set smaller than the outer diameter of the peak of the metal bellows pipe and larger than the outer diameter of the valley.
The annular holder is disposed so as to be located in an inner part of the seal packing, and the insertion resistance value of the metal bellows tube into the annular holder is larger than the insertion resistance value of the metal bellows tube into the seal packing. A metal bellows pipe joint characterized by being set.

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