JP4727077B2 - Plug-in fittings - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plug-in pipe joint having a good sealing property, and more particularly to a plug-in pipe joint that can be satisfactorily sealed and prevented by simply inserting a bellows pipe into a joint body.
[0002]
[Prior art]
In general, as a plug-in type pipe joint for connecting a flexible pipe through which a fluid such as a gas flows, a joint disclosed in, for example, Utility Model Publication No. 2565469 is known. FIG. 9 is a cross-sectional view showing a pipe joint disclosed in the above publication. As shown in the figure, this pipe joint includes a socket 4 formed with a connection hole 2 into which a flexible bellows pipe F is inserted. The tightening member 6 screwed into the open end of the socket 4 and the substantially C-shape mounted between the both ends of the socket 4 and the tightening member 6 so that the tightening member 6 is positioned at the initial screwing position. A positioning member 8; a plurality of retainers 10 which are radially arranged inside the connection hole 2 of the socket 4 and whose inner peripheral surface is formed in an uneven shape corresponding to the outer peripheral surface of the bellows tube F; A holding member 12 is provided that elastically holds the retainer 10 so that the inner diameter is enlarged and reduced. Then, after inserting the bellows tube F between the plurality of retainers 10, the positioning member 8 is removed and the tightening member 6 is screwed and tightened to press the retainer 10 toward the bottom of the connection hole 2. The tube F is fixed to the socket 4.
[0003]
[Problems to be solved by the invention]
By the way, in the above-described conventional pipe joint, when the bellows pipe F is inserted into the connection hole 2 and the positioning member 8 is removed and then the fastening member 6 is fastened to the socket 4, this is performed using a tool (not shown). It is like that. For this reason, there is still a work of tightening with a tool. For this reason, for example, after inserting the bellows tube F, there is a problem that the tightening may be forgotten to cause leakage. In addition, there is a trouble of removing the positioning member, and it cannot be easily connected. Furthermore, an elastic holding member for holding a plurality of retainers is required, and the structure is complicated.
[0004]
Therefore, the present applicant has disclosed a plug-in pipe joint that can be easily connected by simply inserting the bellows tube in the previous application (Japanese Patent Application No. 11-316155). However, this pipe joint has the advantage that it can be connected simply by being inserted, but has an improvement in that the structure is somewhat complicated because a spring or the like is provided inside.
Further, as other conventional pipe joints, those disclosed in JP-A-5-164280, JP-A-5-31289, JP-A-6-58474, JP-A-6-58475, etc. are also known. It has been. In the pipe joints shown in each of these known examples, all use ring springs that are ring-shaped and elastically expandable and contractible, and are fitted into the recesses of the bellows pipe to lock the pipe joints. By doing so, the bellows tube is prevented from falling off and falling off.
However, in this case, since the ring spring has a structure to be mounted in the pipe joint in an expanded state, a member for maintaining the expanded state is required, and the number of parts increases. There was a problem.
The present invention has been devised to pay attention to the above problems and to effectively solve them. An object of the present invention is to provide a plug-in pipe joint that can be securely sealed and attached simply by inserting the bellows pipe into the joint body, and that is simple in structure and safe.
[0005]
[Means for Solving the Problems]
The invention defined in claim 1 is an insertion-type pipe joint for connecting a bellows tube having an uneven portion whose outer peripheral surface is formed in a wavy shape, wherein a tube insertion hole for inserting the bellows tube is formed, and an inner wall surface A joint body formed in a stepped shape, a ring-shaped nut member fixed to the tip of the joint body, a packing member provided on the inner wall surface of the joint body, and when the bellows tube is inserted A ring-shaped guide member that contacts the tip of the bellows tube and moves to the back along the inner peripheral surface of the packing member, and is provided in a ring-shaped receiving groove provided on the outer peripheral surface of the guide member at the initial stage, When the bellows tube is inserted, the coil ring retainer is inserted into the bellows tube while being elastically expanded and contracted in the radial direction of the bellows tube by being brought into contact with the tip of the packing member when the bellows tube is inserted. With components The nut member is formed with a slip-off preventing taper surface that prevents deformation of the retainer member in the diameter expanding direction when a force is applied to the bellows tube in the pulling direction. It is.
[0006]
According to this, when the bellows tube is inserted, the guide member comes into contact with the tip and the guide member is pushed into the joint main body, and at the same time, the bellows tube has a diameter of the retainer member in the ring-shaped retainer member. The retainer member is attached while being expanded and contracted and fitted in the concave portion of the bellows tube. When a force is applied to the bellows tube in the pulling direction, the retainer taper surface formed on the nut member acts. Since it acts so as to prevent the bellows tube from being pulled out, the bellows tube can be connected while maintaining a good sealing property by simply inserting and inserting the bellows tube into the joint body. Therefore, the bellows tube can be easily and reliably connected without complicating the structure of the plug-in type pipe joint.
[0007]
In this case, for example, as defined in claim 2, the groove wall surface on the distal end side of the joint body of the housing groove is formed as a taper surface so that the retainer member comes out of the housing groove when the bellows tube is inserted. Is formed.
For example, as defined in claim 3, the step portion of the joint body functions as a stopper step portion that stops further movement of the guide member when the guide member moves.
[0008]
According to the related art of the present invention, in the plug-in type pipe joint for connecting the bellows pipe having the concavo-convex portion whose outer peripheral surface is formed in a wavy shape, a tube insertion hole for inserting the bellows pipe is formed, and the inner wall surface A joint body formed in a stepped shape, a ring-shaped nut member fixed to the tip of the joint body, a packing member provided on the inner wall surface of the joint body, and provided in the joint body, A coil ring-shaped retainer member that inserts the bellows tube inward while elastically expanding and contracting in the radial direction of the bellows tube when the bellows tube is inserted, and the nut member is pulled out to the bellows tube The plug-type pipe joint is characterized in that a slip-off preventing tapered surface is formed to prevent deformation of the retainer member in the diameter expansion direction when a force is applied in the direction.
According to this, when the bellows tube is inserted, the bellows tube is inserted into the ring-shaped retainer member supported in the joint body while expanding and contracting the diameter of the retainer member, and is fitted into the concave portion of the bellows tube. The retainer member will be mounted in the retracted state, and if a force is applied to the bellows tube in the pulling direction, the pulling prevention taper surface formed on the nut member acts to prevent the bellows tube from being pulled out. By simply inserting the bellows tube into the joint body and inserting the bellows tube, the bellows tube can be connected while maintaining good sealing performance. Therefore, the bellows tube can be easily and reliably connected without complicating the structure of the plug-in type pipe joint.
[0009]
In this case, for example, the coil ring-shaped retainer member is accommodated in a retainer accommodating space formed between a front end portion of the packing member and a rear end portion of the nut member.
Also, the Li retainer member Invite example embodiment is accommodated in the nut member of the proximal ring-shaped retainer housing space provided on the unit.
Further, for example請Motomeko as prescribed in 4, wherein a portion of the shape when the cross section of the retainer member viewed from a direction perpendicular thereto, the cross section of the concave portions of the concavo-convex portion of the outer peripheral surface of the bellows pipe It is formed so as to substantially match the contour of the shape.
According to this, the retainer member is closely accommodated in the concave portion of the bellows tube, thereby improving the holding performance and airtightness of the bellows tube and increasing the pull-out preventing force. .
Further, for example , as defined in claim 5, the joint portion between the joint main body and the nut member is screwed to be screwed together, and subsequently the screwing of the mutual screw portions is released. A flat part is provided.
Thereby, even if the nut member and the joint main body are inadvertently rotated, it is possible to prevent the coupling between the two from being inadvertently loosened.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Below, one Example of the insertion type pipe joint which concerns on this invention is explained in full detail based on an accompanying drawing.
FIG. 1 is a cross-sectional view showing a plug-in pipe joint and a bellows pipe according to the present invention, FIG. 2 is a plan view showing a coil ring retainer member, and FIG. 3 shows a process of inserting the bellows pipe into the plug-in pipe joint. FIG. 4 is a process diagram, FIG. 4 is an enlarged view showing a shape of the retainer member when the cross section is viewed from a direction perpendicular thereto, and FIG. 5 is a diagram showing an engaged state between each retainer member and the bellows tube.
As shown in the figure, this plug-in type pipe joint 16 is for connecting a flexible bellows pipe F made of, for example, stainless steel, and the outer peripheral surface of the bellows pipe F is formed in a wave-like shape with concave portions 18 and convex portions 20. It is formed and covered with a coating layer 22 made of a soft resin such as soft vinyl chloride, except for the connected tip. In addition, a marker 23 indicating a length position to be inserted is provided in advance on a part of the covering layer 22.
[0011]
The insertion-type pipe joint 16 has a joint body 26 in which the inner wall surface is formed in two steps to insert the bellows pipe F and a pipe insertion hole 24 is formed, and a pipe insertion hole 28 in the center. The ring-shaped nut member 30 is mainly configured. The nut member 30 is formed, for example, in a ring shape from brass or the like, and has a tube insertion hole 28 having a size that allows the bellows tube F to be inserted therethrough. The outer surface of the nut member 30 is, for example, cylindrical or hexagonal. The base end portion side of the nut member 30 is fixed to the tip end of the joint body 24 by screwing with a screw portion 32, and a watertight O-ring 34 made of a circular ring-shaped elastic body is provided at the joint portion. Intervene to prevent moisture from entering inside.
[0012]
A watertight packing 36 made of a circular ring-shaped elastic body is mounted along the circumferential direction on the inner peripheral surface on the tip side of the nut member 30, and the inner protrusion 36 </ b> A of the watertight packing 36 is inserted. It seals closely with the coating layer 22 of the bellows tube F, and prevents corrosive water or the like from entering the pipe joint from the outside.
A part of the nut member 30 is provided with a through hole extending in the radial direction, and a selectively permeable member 38 that allows gas to permeate from the inside to the outside but does not permeate solids or liquids. is there.
The permselective member 38 allows gas to permeate from the inside of the joint to the outside, so that in the unlikely event that a gas is leaked due to a hole in the bellows tube F by nailing or the like, the surface of the bellows tube F and the resin coated on the outer surface of this The gas enters the joint through the gap between the coating layer 22 and the gas passes through the permselective member 38 and is ejected to the outside of the pipe joint 16. For this reason, after the bellows pipe F is piped, a gas leak detector is brought close to the portion of the selectively permeable member 38 of the pipe joint 16 so that the hole opening failure of the bellows pipe F can be easily detected. Gas accidents can be prevented.
[0013]
An airtight packing member 40 made of an elastic body in the shape of a circular ring and a fireproof packing member 42 made of an elastic body in the form of a circular ring connected thereto are fixed to the step portion on the distal end side of the joint body 26. Is provided. The airtight packing member 40 is made of, for example, NBR (nitrile rubber), fluorine rubber, or the like, and the fireproof packing member 42 is made of, for example, an elastic body integrally formed with expanded graphite and a rubber material such as NBR, When exposed to a high temperature such as in a fire, the volume of the fireproof packing member 42 expands to seal the inside. The inner diameters of the airtight packing member 40 and the fireproof packing member 42 are set so as to be approximately intermediate between the diameter of the convex portion 20 of the bellows tube F and the diameter of the concave portion 18, respectively. At the time of insertion, the bellows tube F can be inserted while elastically pressing the inner peripheral surfaces of the packing members 40 and 42.
[0014]
The inner diameters of the packing members 40 and 42 and the inner diameter of the stepped portion on the base end side of the joint body 26 are set to be substantially the same, and both inner peripheral surfaces are level surfaces. Further, a stepped portion having a narrower inner diameter, that is, a stopper stepped portion 26A is formed at the back of the stepped portion.
A ring-shaped guide member 44 that can be slidably moved back along the inner peripheral surface is fitted into the distal end portion of the hermetic packing member 40. The guide member 44 is made of, for example, a brass material, a stainless steel material, or the like, and has a cylindrical support having an outer diameter set slightly smaller than the inner diameter of the concave portion 18 of the bellows tube F at the tip thereof. The cylinder 46 is provided so as to extend forward.
[0015]
A receiving groove 48 (see FIG. 3B) having a semicircular cross section or a slope that is widened outward is formed in a ring shape on the outer peripheral surface of the guide member 44. The groove wall surface on the distal end side of the housing groove 48 is formed as a tapered surface 48 </ b> A so that the retainer member 50 can easily come out of the housing groove 48. A coil ring-shaped retainer member 50 formed by forming a coil spring into a ring shape as shown in FIG. 2 is provided in the ring-shaped receiving groove 48. Therefore, the coil ring-like retainer member 50 can be elastically expanded and contracted in the radial direction to change its diameter elastically. Here, the retainer member 50 is fitted into the receiving groove 48 in a substantially natural state that is not enlarged or reduced in the radial direction. The outer diameter D1 (see FIG. 2) of the retainer member 50 is set to be slightly larger than the inner diameter of the hermetic packing member 40. When the guide member 44 slides backward, the retainer member 50 The airtight packing member 40 is caught on the tip.
[0016]
The base end portion of the nut member 30 is formed with a slip prevention taper surface 52 that is inclined at a predetermined angle in the axial direction along the distal direction at a predetermined angle. When the force is applied in the pull-out direction, the retainer member 50 abuts against the slip-off preventing taper surface 52 to prevent deformation in the diameter-expanding direction, and when the bellows tube F is not inserted, When the guide member 44 moves in the removal direction (front end direction), the retainer member 50 comes into contact with the removal prevention taper surface 52 to prevent the removal.
[0017]
Next, the usage method of the insertion type pipe joint comprised as mentioned above is demonstrated.
First, the worker inserts the distal end portion of the bellows tube F through the tube insertion hole 28 of the nut member 30 and the tube insertion hole 24 of the joint body 26 from the state shown in FIG. The state at this time is shown in FIG. 3A, and when the support tube 46 of the guide member 44 enters the bellows tube F and the tip of the bellows tube F is bent, the insertion direction is corrected. It is like that.
If the bellows tube F is further pushed in from this state, the tip of the bellows tube F comes into contact with the tip of the guide member 44 as shown in FIG. The guide member 44 slides on the inner surfaces of the packing members 40 and 42 as they are pushed in. At this time, the coil ring-shaped retainer member 50 accommodated in the accommodating portion 48 on the outer peripheral surface of the guide member 44 abuts on the tip of the airtight packing member 40 and is pushed out from the accommodating groove 48. Left behind in position. When the retainer member 50 is pushed out from the receiving groove 48, the diameter of the retainer member 50 is slightly elastically expanded.
[0018]
When the bellows tube F is further pushed in this state, as shown in FIG. 3C, the guide member 44 is pushed by the tip of the bellows tube F and slides further to the back of the joint body 26. The distal end of 26 abuts against the stopper step portion 26A on the proximal end side of the joint body 26, and further sliding movement is prevented.
At this time, the outer peripheral surface of the bellows tube F slides while contacting the inner peripheral surfaces of the packing members 40 and 42 made of an elastic body and elastically pressing and deforming them. At the same time, the coil ring-shaped retainer member 50 comes into contact with the outer peripheral surface of the bellows tube F, and allows the bellows tube F to be inserted inside while elastically expanding and contracting in the radial direction. The example shown in FIG. 3C shows a state in which the three protrusions 20 have passed through the ring-shaped retainer member 50, and at the same time as the bellows tube F is inserted, the ring-shaped inner protrusion of the watertight packing 36 is shown. The portion 36A is in contact with the outer peripheral surface of the covering layer 22 of the bellows tube F in a bent state, and the airtightness thereof is maintained. As a result, the bellows tube F is completely attached to the pipe joint 16.
[0019]
Here, when a force is applied to the bellows tube F in the pulling direction, the retainer member 50 fitted in the concave portion 18 of the bellows tube F is formed on the base end of the nut member 30 so as not to come off. And the ring-shaped retainer member 50 is pressed in the direction of diameter reduction. Accordingly, the retainer member 50 is sandwiched between the slip-off preventing taper surface 52 and the concave portion 18 of the bellows tube F so that the further movement is blocked, and the bellows tube F comes off the pipe joint 16 and falls off. Never do.
Thus, without complicating the structure of the pipe joint 16 so much, the bellows pipe F can be mounted while maintaining a reliable sealing property simply by inserting and pushing the bellows pipe F into the pipe joint 16. Moreover, it is possible to prevent the bellows tube F from coming out of the pipe joint 16 and falling off. Further, every time the retainer member 50 climbs over one of the concave and convex portions 18 and 20 of the bellows tube F, the operator can feel a click, so that the insertion state can be grasped sensuously.
[0020]
In addition, here, the coil ring-shaped retainer member 50 is formed in a substantially circular shape as shown in FIG. 4A when viewed from the cross-sectional direction of the line AA in FIG. On the other hand, since the uneven shape of the bellows tube F has a shape substantially similar to a sine curve, the contour shapes of the two are slightly different. Therefore, as shown in FIG. 5, when the retainer member 50 is accommodated in the concave portion 18 of the bellows tube F, the two do not come into close contact with each other, and a slight gap 70 is generated. There is a fear of being slightly inferior.
[0021]
Therefore, in order to prevent this deterioration, a part of the shape of the retainer member 50 when viewed from the direction perpendicular to the cross section thereof is obtained by changing the cross-sectional shape of the concave portion of the concave and convex portion on the outer peripheral surface of the bellows tube F. It is preferable to form so as to substantially match the contour. An example of the retainer member having such a cross-sectional shape is shown in FIGS. 4B and 4C. In the retainer member 50B shown in FIG. 4B, the shape of the retainer member 50B shown in FIG. 4B is close to a substantially elliptical shape when the cross section is viewed from the direction orthogonal thereto. Is slightly larger than that of the retainer member 50 having a perfect circular cross section shown in FIG. Therefore, when the retainer member 50B shown in FIG. 4 (B) is accommodated in the concave portion 18 of the bellows tube F, as shown in FIG. It is possible to keep it high.
[0022]
In addition, the retainer member 50C shown in FIG. 4 (C) has a shape close to a tear shape when the cross section is viewed from a direction orthogonal thereto, and the lower end of the retainer member 50C in FIG. 4 (C). The curvature of the portion 74 is also slightly larger than that of the retainer member 50 having a perfect circular cross section shown in FIG. Therefore, when the retainer member 50C shown in FIG. 4 (C) is accommodated in the concave portion 18 of the bellows tube F, as shown in FIG. 5, as shown in FIG. It is possible to maintain sufficiently high retention and adhesion of the bellows tube F.
In the above-described embodiment, a guide member 44 that slides and moves along the inner surface side is provided in the joint body 16, and an accommodation groove 48 on the outer peripheral surface of the guide member 44 is formed to expand and contract the diameter. Although the structure is such that the substantially natural coil ring-shaped retainer member 50 is accommodated, the installation of the guide member 44 may be omitted.
[0023]
FIG. 6 is a cross-sectional view showing a modification of the plug-in pipe joint of the present invention. 6A is a cross-sectional view showing a modification of the plug-in joint, and FIG. 6B is a cross-sectional view showing a state in which the bellows tube F is inserted into the pipe joint. The same members as those shown in FIG. 1 are denoted by the same reference numerals and description thereof is omitted.
Here, the base end portion of the nut member 30 shown in FIG. 1 is further extended to the back, and a ring shape having a substantially triangular cross section formed between the slip-off preventing tapered surface 52 and the distal end portion of the airtight packing member 40. This space is used as a retainer housing space 53, in which a coil ring-shaped retainer member 50 in a substantially natural state whose diameter is not expanded or contracted is housed.
[0024]
Here, instead of the support cylinder 46 provided on the guide member 44 shown in FIG. 1, a support cylinder 54 is provided inside the joint body 26. A circular ring-shaped space 56 is provided on the outer peripheral side of the distal end portion of the hermetic packing member 40, and the distal end portion of the hermetic packing member 40 is easily bent and deformed when the bellows tube F is inserted. ing.
The operation in this embodiment is substantially the same as that described with reference to FIG. 3 except for the action of the guide member 44 in FIG. Here, when the bellows tube F is inserted, the coil ring-shaped retainer member 50 abuts against the tip portion of the airtight packing member 40 and is held here, and the bellows tube F is placed inside the retainer member 50 inside the retainer member 50. It is inserted while expanding and contracting the diameter.
Also in this case, the bellows tube F can be mounted while maintaining a reliable sealing property simply by inserting and pushing the bellows tube F into the pipe joint 16.
[0025]
Further, in the modified example shown in FIG. 6, the retainer accommodating space 52 is formed between the taper surface 52 for preventing the omission and the distal end surface of the airtight packing member 40. Instead, the retainer is accommodated at the base end portion of the nut member. A space may be provided to accommodate the retainer member.
FIG. 7 is a cross-sectional view showing another modification of the plug-in type pipe joint of the present invention. FIG. 7A is a cross-sectional view showing another modification of the plug-in type pipe joint, and FIG. 7B is a cross-sectional view showing a state in which the bellows pipe F is inserted into the pipe joint. The same members as those shown in FIG. 6 are denoted by the same reference numerals, and description thereof is omitted.
Here, as shown in FIG. 7, a taper surface 52 for preventing slippage is provided on the base end side of the nut member 30, and further, a ring-shaped protrusion 60 is provided at the end toward the inside in the radial direction. A retainer member space 62 is formed between the protrusion 60 and the slip-off preventing taper surface 52, and the retainer member 50 is accommodated therein. In this case, since the nut member 30 is formed of a hard member such as stainless steel, the diameter of the retainer member 50 is allowed to expand and contract when the bellows tube F is inserted on the inner surface side defining the retainer housing space 62. An elastic member 64 made of, for example, foam urethane or the like having a predetermined thickness is provided in a ring shape. In addition, the retainer member 50 may be accommodated in the retainer accommodating space 62 in a loosely fitted state within a range in which the central axis of the retainer member 50 is not greatly shifted without providing the elastic member 64.
[0026]
Also in this embodiment, when the bellows tube F is inserted, the coil ring-shaped retainer member 50 abuts against the protrusion 60 of the nut member 30 and is held here, and the inside of the retainer member 50 is held inside the bellows tube F. Is inserted while expanding and reducing the diameter of the retainer member. Also in this case, the bellows tube F can be mounted while maintaining a reliable sealing property simply by inserting and pushing the bellows tube F into the pipe joint 16.
[0027]
Further, in the pipe joint shown in each of the above-described embodiments, the joint body 26 and the nut member 30 are screwed together by the screw portion 32 to be firmly fixedly joined. You may comprise as shown in. Here, although the case where the pipe joint shown in FIG. 1 is deformed is shown, the threaded portion 32A of the joint body 26 and the threaded portion 32B of the nut member 30 are only partially provided in the length direction thereof. Flat portions 35A and 35B for releasing the screwing of the screw portions 32A and 32B are provided following the screw portions 32A and the screw portions 32B, respectively. Accordingly, when the screwing of the screw parts 32A and 32B is advanced, the screw parts 32A and 32B reach the mating flat parts 35B and 35A, respectively, and the screwed state is released. . The joint body 26 and the nut member 30 are coupled in a loosely fitted state with play of a distance ΔL along the axial direction of each other.
According to this, the nut member and the joint body are coupled in a loose fit state, and in order to separate them, the nut member must be rotated in the release direction while being pulled in the opposite directions. Even if the joint body is rotated, it is possible to prevent the coupling between the two from being loosened inadvertently.
In addition, the material of each member in each of the above embodiments is merely an example, and it is needless to say that the material is not limited thereto.
[0028]
【The invention's effect】
As described above, according to the plug-in type pipe joint of the present invention, the following excellent operational effects can be exhibited.
By the present invention lever, and at the same time when the bellows tube is inserted into the tip guide member the guide member abuts is pushed into the fitting body, the bellows tube in a ring-shaped retainer member, the retainer member The retainer member is attached with the diameter of the bellows tube inserted while expanding and contracting, and when the force is applied to the bellows tube in the pulling direction, the removal preventing taper surface of the nut member is formed. Since the action acts to prevent the bellows tube from being pulled out, the bellows tube can be connected in a state of maintaining a good sealing property by simply inserting the bellows tube into the joint body and inserting it. . Therefore, the connection operation of the bellows tube can be performed easily and reliably without complicating the structure of the plug-in type pipe joint so much.
In particular, according to the invention defined in claim 4, the retainer member is closely accommodated in the concave portion of the bellows tube, thereby improving the holding performance and airtightness of the bellows tube, thereby preventing this pull-out preventing force. Can be bigger.
In particular, according to the invention defined in claim 5, even if the nut member or the joint body is inadvertently rotated, the coupling between the two can be prevented from being inadvertently loosened.
According to the related art of the present invention, when the bellows tube is inserted, the bellows tube is inserted into the ring-shaped retainer member supported in the joint body while expanding and contracting the diameter of the retainer member. The retainer member is mounted in the state of being fitted into the recess, and when a force is applied to the bellows tube in the pulling direction, the bellows tube is prevented from being pulled out by the action of the slip-off preventing tapered surface formed on the nut member. Therefore, it is possible to connect the bellows tube while maintaining good sealing performance by simply inserting and inserting the bellows tube into the joint body. Therefore, the connection operation of the bellows tube can be performed easily and reliably without complicating the structure of the plug-in type pipe joint so much .
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a plug-in pipe joint and a bellows pipe of the present invention.
FIG. 2 is a plan view showing a coil ring-shaped retainer member.
FIG. 3 is a process diagram showing a process of inserting a bellows tube into a plug-in type pipe joint.
FIG. 4 is an enlarged view showing a shape of a retainer member when a cross section is viewed from a direction perpendicular thereto.
FIG. 5 is a diagram showing an engaged state between each retainer member and a bellows tube.
FIG. 6 is a sectional view showing a modification of the plug-in type pipe joint of the present invention.
FIG. 7 is a cross-sectional view showing another modification of the plug-in type pipe joint of the present invention.
FIG. 8 is a view showing still another modified example of the plug-in type pipe joint of the present invention.
FIG. 9 is a cross-sectional view showing a conventional general plug-in fitting.
[Explanation of symbols]
16 Plug-in type pipe joint 18 Concave portion 20 Convex portion 22 Cover layer 26 Joint body 26A Stopper step portion 30 Nut member 40 Airtight packing member (packing member)
42 Fireproof packing member (packing member)
44 Guide member 48 Housing groove 48A Exit taper surface 50 Retainer member 52 Removal prevention taper surface F Bellows tube

Claims (5)

In the plug-in type pipe joint for connecting the bellows pipe having the concavo-convex part whose outer peripheral surface is formed in a wavy shape,
A joint body in which a tube insertion hole for inserting the bellows tube is formed and the inner wall surface is formed in a stepped shape; and
A ring-shaped nut member fixed to the tip of the joint body;
A packing member provided on the inner wall surface of the joint body;
A ring-shaped guide member that contacts the tip of the bellows tube when the bellows tube is inserted and moves to the back along the inner peripheral surface of the packing member;
Initially provided in a ring-shaped receiving groove provided on the outer peripheral surface of the guide member, and when the bellows tube is inserted, it abuts against the tip of the packing member and is pushed out of the receiving groove to be radius of the bellows tube A coil ring-shaped retainer member that allows the bellows tube to pass inside while elastically expanding and contracting in the direction,
The nut member is formed with a slip-off preventing taper surface that prevents deformation of the retainer member in the diameter expanding direction when a force is applied to the bellows tube in the pulling direction. .   2. The groove wall surface on the distal end side of the joint body of the receiving groove is formed as a tapered surface so that the retainer member comes out of the receiving groove when the bellows tube is inserted. Plug-in fittings.   The plug-in type pipe joint according to claim 1 or 2, wherein the step portion of the joint body functions as a stopper step portion for stopping further movement of the guide member when the guide member moves. . A part of the shape of the retainer member when viewed from the direction orthogonal thereto is formed so as to substantially match the contour of the cross-sectional shape of the concave portion of the concave-convex portion of the outer peripheral surface of the bellows tube. claim 1乃optimum 3, whichever is bayonet type pipe coupling according to one paragraph, wherein. The joint portion between the joint body and the nut member is provided with a screw portion that is screwed together, and subsequently, a flat portion that releases the screwing of the screw portions. bayonet type pipe joint according to any one of claims 1乃optimum 4.

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