JP2010043705A - Joint for flexible tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joint for a flexible tube, which does not have a tendency to allow leakage of fluid therefrom. <P>SOLUTION: The joint 10 for a flexible tube includes a joint body 20, and an elastically-deformable seal material 22 which is accommodated in the joint body 20. A pipe penetration hole 60 is formed at the center of the seal material 22. The flexible tube 300 is inserted into the pipe penetration hole 60. The seal material 22 provides sealing between the external peripheral face of the flexible tube 300 inserted into the pipe penetration hole 60 and the internal peripheral face of the joint body 20. A protrusion 50 which opposes the external peripheral face of the flexible pipe 300 is formed at the internal peripheral side of the seal material 22, and the protrusion 50 is engaged with a trough part 312 of the flexible pipe 300 by inserting the flexible tube 300 into the pipe penetration hole 60 of the seal material 22 while getting over a mountain part 310 of the flexible tube 300. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a joint for flexible pipes that hardly causes fluid leakage.

  Patent Document 1 discloses a joint for flexible pipe as shown in FIG. This flexible pipe joint includes a joint body 200, a sleeve 202, a ring spring 204, an O-ring 206, a packing 208, and a push ring 210.

  A large diameter hole 200a, a medium diameter hole 200b, and a small diameter hole 200c are formed in the joint body 200 in order from the inlet side. The sleeve 202 is slidably mounted in the medium diameter hole 200 b of the joint main body 200 and engages with the distal end portion of the flexible tube 300. The inlet side of the sleeve 202 extends to the large diameter hole 200 a of the joint body 200. The ring spring 204 is formed in an annular shape, expands and contracts due to elastic deformation, is fitted into the outer periphery of the valley portion 312 of the flexible tube 300 in a state where no load is applied, and is attached to the outer surface on the inlet side of the sleeve 202 in the expanded state. The The push ring 210 is screwed to the inlet side of the joint body 200 via an O-ring 206. A packing 208 is attached to the inner peripheral surface of the pusher wheel 210. The inner peripheral surface in the vicinity of the inner rear end of the pusher wheel 210 is formed to have a smaller diameter than the outer diameter of the ring spring 204 when the ring spring 204 is fitted into the outer periphery of the valley 312.

JP-A-6-185680

  However, the flexible pipe joint disclosed in Patent Document 1 has a problem that fluid leakage is likely to occur.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a joint for flexible pipes that is less likely to cause fluid leakage.

  In order to achieve the above object, according to one aspect of the present invention, the flexible pipe joint 10 includes a joint body 20 and an elastically deformable seal member 22 accommodated in the joint body 20. The flexible tube 300 is inserted into the joint body 20. On the outer periphery of the flexible tube 300, peaks 310 and valleys 312 extending along the entire circumference are alternately arranged in the tube axis direction. A tube insertion hole 60 is formed in the center of the sealing material 22. The flexible tube 300 is inserted into the tube insertion hole 60. The sealing material 22 seals between the outer peripheral surface of the flexible tube 300 inserted into the tube insertion hole 60 and the inner peripheral surface of the joint body 20. On the inner peripheral side of the sealing material 22, there is a convex portion 50 facing the outer peripheral surface of the flexible tube 300, and the convex portion 50 is formed by inserting the flexible tube 300 into the tube insertion hole 60 of the sealing material 22. Then, it climbs over the peak portion 310 of the flexible tube 300 and engages with the valley portion 312 of the flexible tube 300.

  According to the present invention, it is difficult to cause fluid leakage.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  FIG. 1 is a half-broken cross-sectional view showing a flexible pipe joint 10 according to an embodiment of the present invention in a state before insertion of a flexible pipe 300. FIG. 2 is a half cutaway cross-sectional view of the flexible pipe joint 10 shown in the middle of insertion of the flexible pipe 300. FIG. 3 is a half-broken cross-sectional view of the flexible pipe joint 10 shown in a state after the insertion of the flexible pipe 300 is completed. FIG. 4 is a half-broken cross-sectional view of the flexible pipe joint 10 when a pulling force is applied to the flexible pipe 300. FIG. 5 is a plan view of the ring 26 with protrusions according to the embodiment of the present invention. FIG. 6 is a perspective view of the support member 28 according to the embodiment of the present invention.

  As shown in FIG. 1, the flexible pipe joint 10 according to the present embodiment includes a joint body 20, a seal material 22, a push ring 24, a ring 26 with a protrusion, a support member 28, and a ring 30.

  An insertion port 40 is formed at one end of the joint body 20. A connecting male thread 48 is formed on the outer periphery of the other end of the joint body 20. The insertion port 40 is a part into which the tip of the metal flexible tube 300 is inserted. The sealing material 22 is accommodated in the joint body 20. The push ring 24 is screwed inside the insertion port 40. The pusher wheel 24 has a tube insertion hole 36. The ring 26 with protrusions, the support member 28, and the ring 30 are accommodated in the insertion port 40 of the joint body 20.

  As shown in FIG. 2, the flexible tube 300 has crests 310 and troughs 312 extending along the entire circumference in the outer circumferential portion alternately arranged in the tube axis direction, and the outer circumference is made of a synthetic resin such as vinyl chloride. Covered with layer 314.

  As shown in FIG. 1, an accommodation portion 42 is provided at the back of the insertion port 40 of the joint body 20. The sealing material 22 is accommodated in the accommodating portion 42. In the housing portion 42, the sealing material 22 can move in the axial direction of the joint body 20. A stopper portion 44 is provided at the back of the accommodating portion 42. A collar 46 is provided at the center of the stopper portion 44. When the flexible tube 300 is inserted into the joint body 20 and the tip of the flexible tube 300 reaches the stopper portion 44, the tip of the collar 46 is fitted into the flexible tube 300.

  In the present embodiment, the sealing material 22 is a rubber cylinder. Examples of rubber used as the material of the sealing material 22 include NBR (Acrylonitrile-Butadiene Rubber), SBR (Styrene-butadiene rubber), EPDM (ethylene propylene rubber), and the like. A convex portion 50 is provided on the inner peripheral surface of the sealing material 22.

  As shown in FIG. 5, the ring 26 with a protrusion is a washer-like member provided with a protrusion 70 on the inner periphery. When the flexible tube 300 passes through the inner periphery of the ring 26 with the protrusion, the protrusion 70 is pushed and widened by the peak portion 310 of the flexible tube 300. When the peak portion 310 passes the inner periphery of the ring 26 with the protrusion, the protrusion 70 returns to the state before the peak portion 310 passes.

  As shown in FIG. 6, the support member 28 has a ring portion 80 and a plurality of claws 82. The claw 82 is formed so as to be integrated with the ring portion 80. The ring 30 described above is fitted into the step 92 at the tip of the claw 82 to prevent the claw 82 from spreading. The ring 26 with protrusions and the support member 28 constitute a retaining mechanism that prevents the flexible tube 300 from being pulled out. A mechanism for preventing withdrawal by the retaining mechanism will be described later.

  As shown in FIG. 1, the pusher wheel 24 has a packing groove 90. The packing groove 90 is provided on the inner periphery of the end of the push wheel 24 on the inlet side. The packing groove 90 is formed in the circumferential direction. The waterproof packing 100 is fitted in the packing groove 90. The waterproof packing 100 is made of EPDM or the like. The cross section of the waterproof packing 100 is T-shaped.

  Next, the point which connects the flexible pipe 300 to the flexible pipe joint 10 mentioned above is demonstrated, referring FIGS. 1-3.

  In the joint body 20, a sealing material 22, a ring 26 with protrusions, a support member 28, and a ring 30 are accommodated in advance, and a push ring 24 is screwed into the insertion port 40 of the joint body 20. ing.

  When connecting the flexible tube 300, first, the flexible tube 300 (the synthetic resin layer 314 of the flexible tube 300 is peeled off in advance. As a result, about six peaks 310 of the flexible tube 300 are exposed. ) Is inserted into the insertion port 40 of the joint body 20 through the tube insertion hole 36 of the push ring 24. The tip of the flexible tube 300 that has passed through the push ring 24 contacts the projection 70 of the ring 26 with projection after passing through the inner periphery of the support member 28.

  The tip of the flexible tube 300 in contact with the protrusion 70 pushes the protrusion 70 as it is. At this time, the seal material 22 and the ring 26 with the protrusion move in the axial direction of the accommodating portion 42. Thereafter, when one end of the sealing material 22 hits the stopper portion 44, the protrusion 70 of the ring 26 with protrusions is spread by the tip of the flexible tube 300. The movement of the sealing material 22 is restricted by the stopper portion 44. Such a limitation is not applied to the support member 28. Thereby, the support member 28 can freely move in the axial direction of the joint body 20. Since the support member 28 can move, there is enough space for the ring 26 with protrusions to deform. As a result, the flexible pipe 300 can be connected to the flexible pipe joint 10 simply by being inserted. FIG. 2 shows the situation at this point.

  When the protrusion 70 of the ring 26 with protrusions is pushed and expanded by the tip of the flexible tube 300, the tip of the flexible tube 300 passes through the ring 26 with protrusions and enters the tube insertion hole 60 of the sealing material 22. When the flexible tube 300 is inserted into the tube insertion hole 60 of the seal material 22, the convex portion 50 of the seal material 22 gets over the peak portion 310 of the flexible tube 300 and engages with the valley portion 312 of the flexible tube 300. Thereafter, until the leading end of the flexible tube 300 abuts against the stopper portion 44, the convex portion 50 of the sealing material 22 repeatedly goes over the mountain portion 310 of the flexible tube 300 and engages with the valley portion 312 of the flexible tube 300. When the tip of the flexible tube 300 hits the stopper portion 44, the insertion of the flexible tube 300 is completed. FIG. 3 illustrates this situation.

  Assume that a pulling force is applied to the flexible tube 300 after the insertion of the flexible tube 300 is completed. In this case, the flexible tube 300 moves slightly in the direction of its pulling force. Since the convex portion 50 is engaged with the valley portion 312, the sealing material 22 moves similarly. The ring 26 with protrusions is moved in the same manner by being pushed by the sealing material 22. The support member 28 is pushed by the ring 26 with protrusions and moves, and then hits the tip of the pusher wheel 24. Thereby, the sealing material 22, the ring 26 with a protrusion, and the support member 28 cannot move any more. FIG. 4 illustrates this situation.

  If further pulling force is applied in this state, the protrusion 70 of the ring 26 with protrusions receives a force from the peak portion 310 of the flexible tube 300. On the other hand, since the projection 70 receives a reaction force from the support member 28, the projection 70 does not expand as when the flexible tube 300 is inserted into the joint body 20. The protrusion 70 remains fitted in the valley 312. As a result, the flexible pipe 300 cannot be removed from the flexible pipe joint 10.

  The embodiments disclosed herein are illustrative in all respects. The scope of the present invention is not limited based on the above-described embodiment, and various design changes may be made without departing from the spirit of the present invention.

  For example, the present invention is not limited to the male threaded flexible pipe joint in which the insertion port 40 is formed at one end of the joint body 20 and the connection male thread 48 is formed at the outer periphery of the other end of the joint body 20. Needless to say, the present invention can be applied to other structures, for example, symmetrical socket-type joints for flexible pipes having elbows at both ends, elbow-type joints for flexible pipes, and the like.

  Further, the present invention is not limited to the case where the sealing material seals two portions of the valley 312 of the flexible tube 300. Of the sealing material, the portion that is in close contact with the valley 312 of the flexible tube 300 may be only one location, or may be three or more locations.

  Further, the interval between the convex portions 50 may be smaller than the interval between the valley portions 312 of the flexible tube 300. This is because the interval between the convex portions 50 is widened by elastic deformation when meshing with the valley 312 of the flexible tube 300.

  Further, the retaining mechanism is not limited to the one described above.

  Further, the push wheel is not limited to one that is screwed into the insertion port 40. FIG. 7 is a half-broken cross-sectional view showing the flexible pipe joint 11 according to the first modification of the present invention in a state before insertion of the flexible pipe. The flexible pipe joint 11 according to this modification includes a joint body 21 and a push ring 25 instead of the joint body 20 and the push ring 24 described above. The joint body 21 has a snap ring engaging groove 110. The snap ring engagement groove 110 is formed on the inner periphery of the insertion port 40. The push ring 21 has a snap ring receiving groove 112. The snap ring housing groove 112 is formed on the outer periphery of the portion of the pusher wheel 21 that is inserted into the insertion port 40. The pusher wheel 25 is fixed to the joint body 21 by a snap ring 120. The outer periphery of the snap ring 120 is fitted in the snap ring engaging groove 110, and the inner circumference of the snap ring 120 is fitted in the snap ring receiving groove 112. The other points are the same as those of the joint body 20 and the pusher wheel 24 described above. Even if it is such a structure, the effect similar to the coupling 10 for flexible pipes mentioned above can be acquired.

  Further, the push wheel is not always necessary. FIG. 8 is a half-broken cross-sectional view showing the flexible pipe joint 12 according to the second modification of the present invention in a state before the flexible pipe is inserted. The flexible pipe joint 12 according to this modification includes a joint body 32, a seal material 22, a retainer 33, and a retaining member 34. The seal member 22, the retainer 33, and the retaining member 34 are made of rubber having different elastic coefficients. When the flexible pipe 300 is inserted into the flexible pipe joint 12, the sealing material 22 slides in the direction of the stopper portion. Accordingly, the retainer 33 also slides in the direction of the stopper portion. As a result, a gap is formed around the retaining member 34, so that the retaining member 34 can increase its outer diameter and inner diameter. Thereby, the flexible tube 300 can be inserted into the joint 12 for flexible tubes. On the other hand, when the flexible pipe 300 is to be pulled out from the flexible pipe joint 12, the retaining member 34 is pressed against the inner wall of the joint body 32. Thereby, the inner periphery of the retaining member 34 bites into the flexible tube 300. This prevents the flexible tube 300 from coming off. The principle for sealing the outer periphery of the flexible tube 300 and the inner periphery of the joint body 32 is the same as that of the above-described embodiment. Even if it is such a structure, the effect similar to the coupling 10 for flexible pipes mentioned above can be acquired.

It is a half notched cross-sectional view showing the joint for flexible pipe according to the embodiment of the present invention in a state before insertion of the flexible pipe. It is a half notched cross-sectional view of the joint for flexible pipes shown in the state during insertion of the flexible pipes. It is a half notched cross-sectional view of the joint for flexible pipes shown in a state after completion of insertion of the flexible pipes. It is a half notched cross-sectional view of the joint for flexible tube when a pulling force is applied to the flexible tube. It is a top view of the ring with a protrusion concerning the embodiment of the present invention. It is a perspective view of the supporting member concerning the embodiment of the present invention. It is a half notch cross-sectional view which shows the coupling for flexible pipes concerning the 1st modification of this invention in the state before insertion of a flexible pipe. It is a half notched cross-sectional view which shows the joint for flexible pipes concerning the 2nd modification of this invention in the state before flexible pipe insertion. It is a half notched cross-sectional view of a joint for flexible pipe according to a conventional example.

Explanation of symbols

10, 11, 12 Flexible pipe joint 20, 21, 32, 200 Joint body 22 Sealing material 24, 25, 210 Push ring 26 Ring with projection 28 Support member 30, 206 Ring 33 Retainer 34 Retaining prevention material 36 Pipe insertion hole 40 Insertion slot 42 Receiving part 44 Stopper part 46 Collar 48 Male screw 50 Convex part 60 Pipe insertion hole 70 Projection 80 Ring part 82 Claw 90 Packing groove 92 Step part 100 Waterproof packing 110 Snap ring engaging groove 112 Snap ring receiving groove 120 Snap ring 200a Large diameter hole 200b Medium diameter hole 200c Small diameter hole 202 Sleeve 204 Ring spring 208 Packing 300 Flexible pipe 310 Mountain part 312 Valley part 314 Synthetic resin layer

Claims (2)

The fitting body;
An elastically deformable sealing material housed in the joint body,
A flexible tube is inserted into the joint body,
On the outer periphery of the flexible tube, ridges and valleys extending in the entire circumferential direction are alternately arranged in the tube axis direction,
In the sealing material, a tube insertion hole is formed in the center and the flexible tube is inserted,
The sealing material is a joint for flexible pipes that seals between an outer peripheral surface of a flexible pipe inserted into the pipe insertion hole and an inner peripheral surface of the joint body,
On the inner peripheral side of the sealing material, it has a convex portion facing the outer peripheral surface of the flexible tube,
The joint for a flexible pipe is characterized in that the convex part is engaged with a valley part of the flexible pipe by overcoming the peak part of the flexible pipe by inserting the flexible pipe into the pipe insertion hole of the sealing material. . The sealing material has a plurality of the convex portions arranged so as to be aligned in the tube axis direction of the flexible tube,
The adjacent convex portions are connected to each other,
The joint for flexible pipes according to claim 1, wherein an interval between said convex parts is an integral multiple of an interval between trough parts of said flexible pipe.

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