JP2009002456A - Insertion type pipe joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To carry out installation without damaging a seal ring at an end portion of a connecting pipe, to reduce an insertion load of the connecting pipe, and to improve sealing performance of the connecting pipe. <P>SOLUTION: The insertion type pipe joint comprises the seal ring 5 stored in a joint body 2 and adhering closely to an outer peripheral surface of the connecting pipe 11, and a damage preventive sleeve 7 disposed in an inner diameter portion of the seal ring and externally fitting into a terminal of the connecting pipe 11. The damage preventive sleeve 7 is pressed in toward a deep side of the joint body at the terminal of the connecting pipe with the connecting pipe 11 is inserted to be predetermined length, and comes out from the seal ring 5. The seal ring 5 is formed in a shape having an annular seal projecting piece 5b elastically deforming. In a free state, an inner diameter of the seal projecting piece 5b is formed to be smaller dimensions than an outer diameter of the connecting pipe 11. The seal projecting piece 5b deforms to increase a diameter with coming out of the damage preventive sleeve 7, thereby adhering closely to the outer peripheral surface of the connecting pipe 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a plug-in type pipe joint used for connecting a pipe such as a stainless steel pipe for water supply or hot water supply with one touch.

  As this type of one-touch plug-in pipe joint, for example, as shown in FIG. 11, an O-ring 31 is fitted into two circumferential grooves provided on the inner surface of the large-diameter portion of the base body (joint body) 30. A coil spring 32 at the edge of the large-diameter portion and an inner collar 34 made of a synthetic resin that holds a pressing member 33 having a right-angled edge 33a on the inner surface are arranged and covered with a tapered outer collar (press wheel) 35. (See Patent Document 1). According to this plug-in type pipe joint, when the connecting pipe 36 is inserted from the front end of the inner collar 34, the pressing member 33 is pressed toward the front end side of the inner collar 34, but the outer surface of the pressing member 33 is the outer collar 35. By being pressed by the taper surface 35 a and the right-angled edge 33 a on the inner surface bites into the connection pipe 36, the connection between the plug-in type pipe joint and the connection pipe 36 is maintained. When a pulling force acts on the connecting pipe 36 in this coupled state, the pressing member 33 is pressed against the tapered surface 35a side of the outer collar 35 by the elastic force of the coil spring 32, and the right-angled edge 33a of the pressing member 33 is formed by the tapered surface 35a. When the connection pipe 36 is pressed, the connection pipe 36 is prevented from being pulled out.

JP-A-10-122460 (FIGS. 1 to 7)

However, in the conventional plug-in type pipe joint, when an outer edge is generated at the end of the connection pipe 36 when the connection pipe 36 is inserted, the O-ring 31 is damaged at the end, and the O-ring 31 is damaged. Adversely affects the sealing function. For this reason, after the connection pipe 36 is cut, a process such as chamfering for removing the outer edge generated on the cut end face is necessary. Moreover, although the cutting method of the connection pipe | tube 36 in which an outer edge does not generate | occur | produce includes a rotary cutter etc., there existed a restriction | limiting that it was limited to such a cutting method. Further, the connecting pipe 36 may be inserted into the joint body 30 at an angle, but at this time, the O-ring 31 was easily damaged at the end of the connecting pipe 36.
Further, the improvement in surface pressure due to the elasticity of the O-ring 31 itself and the improvement in the insertion operability of the connecting pipe 36 are in a contradictory relationship, and a load (preferably 150 N, limit load 200 N that can be inserted manually into the connecting pipe 36 in practice) ), The surface pressure due to the compression of the O-ring 31, that is, the squeeze rate is 10% to 13% at a nominal diameter 20 Su. At this time, the connecting pipe 36 is bent and inserted (about 3 deg to 5 deg or more). ), A minute leakage of water occurs. For this reason, safety measures such as installing the O-ring 31 in two strips have been taken, but this is disadvantageous in view of economy, and it is desired that a single sealing member such as the O-ring 31 can ensure sealing performance. Is done.

  The present invention has been made to solve such problems, and the object of the present invention is that it can be connected in a seal-like manner by simply inserting the connecting pipe and is limited to a method for cutting the connecting pipe. Depending on the cutting method, an outer edge may be generated on the cutting end face, especially the outer periphery of the connecting pipe end. If you fail to remove the outer edge, or if you insert the connecting pipe diagonally However, it is to provide a plug-in type pipe joint that can be constructed without scratching the seal ring and is excellent in workability. A further object of the present invention is to provide a plug-in type pipe joint that can reduce the insertion load of the connecting pipe and improve the sealing performance by a single seal ring.

The plug-in type pipe joint according to the present invention will be described with reference to the reference numerals attached to FIGS. 1 to 9 in order to facilitate understanding of the contents of the invention. 12) In the plug-in type pipe joint in which the end of the connection pipe (11) is inserted into the receiving part (12) of the joint body (2) having 12), the connection pipe (11) is accommodated inside the joint body (2). A seal ring (5) that is in close contact with the outer peripheral surface of the seal ring (5), and a scratch-preventing sleeve (7) that is disposed on the inner diameter portion of the seal ring (5) and can be fitted onto the end of the connecting pipe (11). As the connecting pipe (11) is inserted to a predetermined length, the scratch-preventing sleeve (7) is pushed into the inner end of the joint body (2) at the end of the connecting pipe (11), and the seal ring ( 5) and the seal ring (5) is connected to the ring body (5a), The ring main body (5a) is formed in a shape having an elastically deformable annular seal protrusion (5b) protruding inward in the radial direction, and the inner diameter of the seal protrusion (5b) in the free state is the connecting pipe (11 ) And the outer diameter of the connecting pipe (11) is deformed by expanding the diameter of the seal protrusion (5b) of the seal ring (5) as the damage prevention sleeve (7) comes out. It is characterized by being in close contact with the surface.
According to such a structure, since the damage prevention sleeve (7) that can be fitted to the end of the connection pipe (11) is provided, when the connection pipe (11) is cut, some outer edges are formed on the cut end face. Even if the processing for generating and removing it is neglected and the connecting pipe (11) is inserted obliquely, the seal ring (5) is not damaged by the outer edge of the end of the connecting pipe (11). Can be constructed. Therefore, there is no restriction on the method of cutting the connecting pipe (11), and the degree of freedom of the cutting work can be obtained.
Since the seal ring (5) has an annular seal protrusion (5b) that can be elastically deformed, the sleeve (5b) is prevented from being damaged by a small insertion load of the connecting pipe (11). 7), and can be easily deformed via the connecting pipe (11), and the sealing protrusion (5b) is made elastic, and the sealing pressure is generated by the water pressure itself. The seal function is exhibited, and the single seal ring (5) effectively exerts the water leakage prevention action.

  The plug-in type pipe joint according to claim 1, as described in claim 2, contains a retaining member (3) that engages with the outer peripheral surface of the connection pipe (11) inside the joint body (2). A configuration can be employed. According to such a configuration, the connection pipe (11) can be connected in a retaining shape with a single touch by simply inserting the connection pipe (11).

The plug-in type pipe joint according to claim 1 or 2, wherein the damage prevention sleeve (7) has a seal ring holding tube portion (7a) for holding the seal ring (5) on the outer periphery. And a connection pipe end receiving portion that is connected to the rear end side of the seal ring holding cylinder portion and has an inner diameter larger than the outer diameter of the connection pipe (11) and can be externally fitted to the end of the connection pipe (11). It can form in the form which has a cylinder part (7b).
According to such a configuration, when the insertion length of the connection pipe (11) is insufficient, the damage prevention sleeve (7) is interposed between the connection pipe (11) and the seal ring (5) as shown in FIG. Since the connecting tube end receiving tube portion (7b) is interposed and the connecting tube (11) is in a non-contact state with the seal ring (5), it is connected to the inner peripheral surface of the scratch-preventing sleeve (7) in the water pressure test. It is possible to detect water leakage from the gap between the pipe (11) and the outer peripheral surface along the outer peripheral surface of the connecting pipe (11) toward the receiving port (12). This water leakage detection can confirm the lack of insertion of the connecting pipe (11).

  According to a third aspect of the present invention, in the plug-in type pipe joint, the seal protrusion piece (5b) of the seal ring (5) in a free state is fitted on the outer periphery of the seal ring holding cylinder (7a). A recessed groove (24) can be formed. According to this, internal stress is not generated in the seal protrusion (5b) of the seal ring (5) before the connection pipe (11) is inserted, that is, during inventory and storage, and the seal protrusion ( 5b) elastically expands the diameter only when the connecting pipe (11) is inserted, and adheres to the outer periphery of the connecting pipe (11), so that an appropriate compression allowance is maintained over a long period of time, and a predetermined service life is obtained. Can be guaranteed. In the claims and specification of the present application, the “free state” means a state in which the seal ring (5) is not deformed so as to expand its diameter and no compressive stress or tensile stress is applied.

The plug-in type pipe joint according to any one of claims 2 to 4, as described in claim 5, is provided between the seal ring (5) in the joint body (2) and the retaining member (3). The elastic member (4) that presses and urges the retaining member (3) toward the inner periphery of the receiving portion (12) is accommodated and disposed, and the retaining member (3) is disposed on the inner periphery of the receiving portion (12). The taper surface (13) for applying a radially inward moving action to the retaining member (3) by the contact of the contact portion (3) can be formed in a narrowed shape toward the outside of the receiving portion (12).
According to such a configuration, when the connecting pipe (11) is completely inserted, the retaining member (3) is pressed against the tapered surface (13) of the receiving port (12) by the elastic member (4), and The diameter of the retaining member (3) is reduced by the tapered surface (13) and engaged with the outer peripheral surface of the connecting pipe (11), so that a reliable retaining state of the connecting pipe (11) is obtained.
Further, when a pulling force is applied to the connecting pipe (11) after the connecting pipe (11) is inserted, the retaining member (3) that accompanies the connecting pipe (11) becomes the tapered surface (13) of the receiving portion (12). , The retaining member (3) moves radially inward, and the engagement force to the outer peripheral surface of the connecting pipe (11) increases. This reliably prevents the connecting pipe (11) from coming out.

  According to the plug-in type pipe joint of the present invention, it can be connected in a seal shape by a so-called one-touch operation by simply inserting the connecting pipe, and there are no restrictions on the cutting method of the connecting pipe. An outer edge may be generated on the outer periphery of the connecting pipe end, but if it is neglected to remove the outer edge, or if the connecting pipe is inserted diagonally, it can be constructed without damaging the seal ring. Excellent. Further, it is advantageous that the insertion load of the connecting pipe can be reduced and the sealing performance can be improved by a single seal ring.

  FIG. 1 is a perspective view of a plug-in type pipe joint showing an embodiment of the present invention, FIG. 2 is a half cutaway cross-sectional view of the plug-in type pipe joint showing a state after the connection pipe is completely inserted, and FIG. FIG. 4 is a cross-sectional view of the plug-in pipe joint showing a state before the pipe is inserted, FIG. 4 is a cross-sectional view of the plug-in pipe joint showing a state during the insertion of the connection pipe, and FIG. FIG. 6 is a perspective view of the damage prevention sleeve of the plug-in type pipe joint, and FIG. 7 is a perspective view of the plug-in type pipe joint. FIG. 8 is a front view of the collar, FIG. 9 is a sectional view of the collar, and FIG. 10 is a half-broken sectional view showing another embodiment of the seal ring.

  As shown in FIGS. 1 to 3, the plug-in type pipe joint 1 includes a joint body 2 having a cylindrical shape with both ends opened, a retaining member 3 accommodated and disposed inside the joint body 2, and an elastic member. 4, a seal ring 5, a scratch prevention sleeve 7, and the like.

  Since the joint body 2 requires corrosion resistance and rigidity, it is manufactured by, for example, a precision casting method using an SCS material or a bronze material. As shown in FIG. 3, the joint body 2 is provided with a first step portion 8 near the center in the axial direction, a large diameter portion 9 on one side and a small diameter portion on the other side across the first step portion 8. A flow path 10 is formed, and an opening end portion of the large diameter portion 9, that is, a receiving end portion 12 into which an end portion of the connection pipe 11 is inserted at one end portion in the axial direction of the joint body 2 is formed, and connected to the outer periphery of the other end portion A male screw 6 is formed. A tapered surface 13 that is tapered toward the outside of the receiving portion on the inner periphery of the opening end side of the receiving portion 12, and a circumferential groove 14 is formed on the outer end of the receiving portion of the tapered surface 13. Yes. A second step portion 19 having a diameter larger than that of the first step portion 8 is provided on the inner periphery of the intermediate portion between the first step portion 8 and the tapered surface 13 in the receiving portion 12.

  As shown in FIG. 3, inside the receiving portion 12, the retaining member 3 that is inscribed in the tapered surface 13, the collar 15 that holds the retaining member 3, and the retaining member 3 together with the collar 15 toward the tapered surface 13. An elastic member 4 that presses and biases is disposed. The retaining member 3 may be formed of a material harder than the connecting pipe 11, for example, martensitic stainless steel (SUS420) when the connecting pipe 11 is austenitic stainless steel (SUS304). A stopper ring 16 is fitted in the circumferential groove 14 of the joint body 2 to prevent the collar 15 from coming out of the receiving portion at the inner diameter portion thereof. The stopper ring 16 can be formed of austenitic stainless steel (SUS304) or the like.

  The elastic member 4 is formed of a compression coil spring or the like, and the rear end portion of the elastic member 4 engages with a step portion 15 a at the front end of the collar 15, and the front end portion of the elastic member 4 is disposed adjacent to the seal ring 5. It is engaged with an annular spacer 17 having a shape. When a compression coil spring is used as the elastic member 4, this member can be formed of austenitic stainless steel (SUS304) or the like.

  The seal ring 5 is formed of an olefin rubber packing or the like so as to be elastically deformable. In particular, the seal ring 5 is formed of EPDM, which is a terpolymer of ethylene, propylene, and a crosslinking diene monomer excellent in chlorine resistance and heat resistance. Further, it can be formed of FKM (fluoro rubber) having excellent heat resistance and chemical resistance. As shown in FIG. 3, the sealing 5 is formed to have a ring body 5a and an elastically deformable annular seal protrusion 5b projecting radially inward of the ring body 5a. The inner diameter of the projecting piece 5 b is smaller than the outer diameter of the connecting pipe 11. In addition to forming the seal ring 5 in a V-shaped or U-shaped cross section as shown in FIG. The seal ring 5 is disposed on the second step portion 19 in the receiving portion 12.

  The damage prevention sleeve 7 is made of plastic, such as PP or PE, or metal. As shown in FIGS. 2 and 6, the inner diameter is substantially the same as or smaller than the inner diameter of the connecting pipe 11, and the outer diameter is a joint. The seal ring holding cylinder part 7a formed smaller than the inner diameter of the inner peripheral surface 20 between the first step part 8 and the second step part 19 in the main body 2, and the rear end side of the seal ring holding cylinder part 7a Are formed in a shape having a thin connecting pipe end receiving tube portion 7 b that is formed to have an inner diameter larger than the outer diameter of the connecting pipe 11 and can be fitted to the end of the connecting pipe 11. . Between the inner peripheral surface of the seal ring holding cylinder part 7a and the inner peripheral surface of the connection pipe end receiving cylinder part 7b, a step part 23 with which the end of the connection pipe 11 abuts is formed. On the outer periphery of the seal ring holding cylinder portion 7a, a concave groove 24 having a substantially V-shaped cross section into which the seal protrusion 5b of the seal ring 5 in a free state is fitted is formed. The rear end portion 7c of the connecting tube end receiving tube portion 7b is formed in a trumpet shape that gradually increases in diameter rearward, so that the end of the connecting tube 11 is inserted into the connecting tube end receiving tube portion 7b when the connecting tube 11 is inserted. The rear end 7c is smoothly inserted without being caught. Slits S are provided at predetermined intervals in the circumferential direction in the connecting tube end receiving cylinder portion 7b. The outer periphery of the front end of the seal ring holding cylinder 7a is rounded or tapered, and is easily inserted into the inner peripheral surface 20 in the joint body 2.

  The collar 15 is formed of a general-purpose engineering plastic such as cross-linked polyethylene or a special engineering plastic such as PPS (polyphenylene sulfide) having excellent heat resistance, and has a plurality of holding holes as shown in FIGS. 15b is provided at predetermined intervals in the circumferential direction, and the retaining member 3 is fitted in each holding hole 15b. A plurality (two in the illustrated example) of engaging teeth 3 a are formed on the inner surface side of each retaining member 3.

  As shown in FIG. 2, before inserting the connecting pipe 11 into the plug-in fitting 1, markings 21 (illustrated by stippling) are made with magic ink or the like at predetermined positions at a predetermined distance from the end of the connecting pipe 11. Put on. The marking 21 is set so as to be positioned at the opening end of the receiving portion 12 as shown in FIG. 2 when the connecting tube 11 is inserted into the receiving portion 12 of the joint body 2 to a predetermined length. For example, the marking 21 is more easily confirmed by coloring it in a conspicuous color such as red or blue.

  The construction procedure of the connecting pipe 11 by the plug-in pipe joint 1 will be described with reference to FIGS.

  First, before the connection pipe 11 is inserted into the plug-in type pipe joint 1 at the site construction, the builder puts a marking 21 (illustrated by a stippling) at a predetermined position at a predetermined distance from the end of the connection pipe 11.

  Further, as shown in FIG. 3, the retaining member 3, the elastic member 4, the seal ring 5, and the scratch-preventing sleeve are sequentially provided in the joint body 2 in order from the receiving portion 12 toward the inner part of the joint body 2. Incorporate all 7 parts. At that time, the seal ring 5 is disposed in a free state so that the seal projection piece 5b fits into the concave groove 24 of the scratch preventing sleeve 7. Stocked and stored in this built-in state.

After that, as shown in FIG. 4, the connecting pipe 11 is inserted into the receiving port 12 of the joint body 2, and the end thereof is inserted into the connecting pipe end receiving tube 7 b of the scratch preventing sleeve 7. The end is brought into contact with the stepped portion 23 in the scratch preventing sleeve 7. With the insertion of the connecting pipe 11, the retaining member 3 moves along the tapered surface 13 of the receiving portion 12 in the inner and inner directions of the joint body 2, and the engaging teeth 3 a engage with the outer peripheral surface of the connecting pipe 11. . Even if an external force is applied in the direction in which the connecting pipe 11 is pulled out in this state, the engaging teeth 3a of the retaining member 3 that contacts the tapered surface 13 of the receiving portion 12 are engaged with the outer peripheral surface of the connecting pipe 11. The connecting pipe 11 will not come out.
Further, when the connecting pipe 11 is inserted, the damage prevention sleeve 7 is interposed between the seal ring 5 and the end of the connecting pipe 11, and in this state, the end face of the end of the connecting pipe 11 is not in contact with the seal ring 5. Since the joint body 2 is inserted in the contact state, even if an outer edge is formed on the end face of the connection pipe 11, the seal ring 5 is not damaged by the outer edge. Even if it is inserted obliquely, the seal ring 5 is not damaged at the end, and water leakage due to damage of the seal ring 5 does not occur.

When the connecting pipe 11 is inserted further deeply, a seal connection state between the joint body 2 and the connecting pipe 11 is obtained as shown in FIG. That is, when the connecting pipe 11 is inserted partway into the joint body 2 in the state shown in FIG. 5, the connecting pipe 11 pushes the scratch-preventing sleeve 7 inward in the joint body, and the seal ring holding cylinder portion 7a is the seal ring. Come to the same position as 5.
Further, when the connecting pipe 11 is inserted, the connecting pipe 11 is connected to the damage prevention sleeve 7 with the seal ring holding cylinder portion 7a contacting the first step portion 8 in the joint body 2 as shown in FIG. The tube end receiving tube portion 7b is pushed inward from the seal ring 5 in the joint body. At the same time, the marking 21 reaches the insertion completion position of the opening end of the receiving port 12. In this process, the scratch-preventing sleeve 7 moves while turning the seal protrusion 5b of the seal ring 5 in the inner direction of the joint body and is detached from the seal ring 5, and the insertion of the connecting pipe 11 is completed as shown in FIG. Then, the seal projecting piece 5b of the seal ring 5 is in close contact with the outer peripheral surface of the connection pipe 11 in a compressed state, and a state of hermetically sealing between the outer peripheral surface of the connection pipe 11 and the inner peripheral surface of the joint body 2 is obtained. A retaining state in which the engaging teeth 3a of the retaining member 3 are engaged with the outer peripheral surface of the connecting tube 11 is obtained.

When the seal protrusion 5b of the seal ring 5 is in a compressed state in close contact with the outer peripheral surface of the connection pipe 11 with the seal protrusion 5b facing inward in the joint body 2, water flowing in the joint body 2 Even if it flows into the seal ring 5 from between the circumference and the damage prevention sleeve 7 or between the end of the connection pipe 11 and the damage prevention sleeve 7, the seal protrusion 5 b is applied to the outer peripheral surface of the connection pipe 11 by the water pressure. A sealing pressure of pressing is generated, so that the sealing function is effectively exhibited by the single seal ring 5.
Further, the seal protrusion 5b of the seal ring 5 is easily slid by the sliding action of the inner surface of the concave groove 24 of the damage prevention sleeve 7 and the outer peripheral surface of the connection tube end receiving tube portion 7b with a small insertion load of the connection tube 11. Therefore, the connecting pipe 11 can be easily inserted and operated.

  When the connection pipe 11 is completely inserted, it is confirmed that the marking 21 of the connection pipe 11 has reached the opening end of the receiving portion 12 so that the connection pipe 11 is securely inserted to a predetermined length. Can be confirmed. Therefore, it is possible to prevent internal water leakage due to insufficient insertion of the connecting pipe 11.

  After the connection pipe 11 is completely inserted, when the connection pipe 11 is pulled in the pulling-out direction, the retaining member 3 that accompanies the connecting pipe 11 comes into contact with the constricted side of the tapered surface 13 so that the retaining member 3 is radially inward. The engaging teeth 3a bite into the outer peripheral surface of the connecting tube 11 to increase the engaging force. This reliably prevents the connection pipe 11 from coming out.

Further, the damage prevention sleeve 7 has the following advantages. The scratch-preventing sleeve 7 has a connecting tube end receiving tube portion 7b that wraps the end of the connecting tube 11, and the length of the sleeve 7 is high when a large force such as high water pressure or water hammer is applied to the connecting tube 11. If it is set to a sufficient length longer than the amount of movement of the connecting pipe 11 to be generated, if the insertion length of the connecting pipe 11 is insufficient, there is a scratch between the connecting pipe 11 and the seal ring 5 as shown in FIG. Since the connecting tube end receiving tube portion 7b of the anti-sticking sleeve 7 is interposed and the connecting tube 11 is not in contact with the seal ring 5, the inner peripheral surface of the anti-scratching sleeve 7 and the outer periphery of the connecting tube 11 in the water pressure test. It can be detected that water leaks in the direction of the receiving port 12 along the outer peripheral surface of the connecting pipe 11 from the gap between the surfaces. In addition to being able to confirm that the connection pipe 11 is insufficiently inserted by this water leak detection, when the connection pipe 11 and the seal projection 5b of the seal ring 5 are in close contact with each other, water leakage is detected when water leak is detected in the water pressure test. Although it is not, it is possible to prevent water leakage during actual use.
In the above water pressure test, if the slits S are provided at predetermined intervals in the circumferential direction as shown in FIG. 6 in the connecting tube end receiving tube portion 7b, a larger water leak can be generated and the detection can be performed. It becomes easy.

  In order to artificially detach the connection pipe 11 from the plug-in type pipe joint 1 after the connection pipe 11 is connected, a screwdriver or the like is inserted from the receiving port 12 and the collar 15 together with the retaining member 3 inside the joint body 2. By pushing inward against the elastic force of the elastic member 4, the tightening force due to contact with the tapered surface 13 of the retaining member 3 is released, and the connecting pipe 11 can be pulled out from the joint body 2. .

  As shown in FIG. 3, before inserting the connecting pipe 11, that is, at the time of inventory and storage, the groove 24 formed in the outer periphery of the seal ring holding cylinder portion 7a of the scratch-preventing sleeve 7 has the seal ring 5 in a free state. The seal protrusion 5b is fitted. If this is inserted into the outer periphery of the seal ring holding cylinder portion 7a without providing the concave groove 24 for storing the seal protrusion 5b of the seal ring 5, the seal protrusion 5b of the seal ring 5 is elastically deformed (expanded). . If left in this state for a long period of time, a so-called “sagging phenomenon” occurs in the seal protrusion 5b, the compression set remains, and even if the load is removed, the inner diameter does not return to the original dimension, and the service life is reached. However, as shown in FIG. 3, in the mounted state in which the seal protrusion 5b of the seal ring 5 in the free state is fitted in the groove 24 formed on the outer periphery of the seal ring holding cylinder portion 7a, the seal protrusion 5b No internal stress is generated, and the seal protrusion 5b is elastically enlarged and deformed only when the connecting pipe 11 is inserted, and is in close contact with the outer periphery of the connecting pipe 11. Can be guaranteed over a certain service life.

  In the above-described embodiment, a plurality of retaining members 3 are respectively fitted into the holding holes 15b provided in the collar 15. However, instead of this, the retaining member 3 is not shown in the drawing, but overall The ring is formed into a single ring shape, and the inner diameter portion thereof is provided with engaging teeth that bite into the outer peripheral surface of the connecting pipe 11, and this is accommodated and arranged on the tapered surface 13 of the inner periphery of the receiving portion 12. It may be. In this case, the collar 15 and the elastic member 4 are not necessary.

  Furthermore, in the said Example, although the external thread adapter plug-in type pipe joint which formed the external thread 6 for connection in the one side of the coupling body 2 was described, this invention is not limited to this, Other structures, for example, left-right symmetry Of course, the present invention can also be applied to socket-type plug fittings, elbow-type plug fittings, and the like. Further, the connecting pipe 11 is not limited to a metal pipe such as a stainless steel pipe, and can be applied to a connecting pipe made of resin, for example, a connecting pipe made of vinyl chloride.

It is a perspective view of the plug-in type pipe joint of one example of the present invention. It is a half notched cross-sectional view of the plug-in type pipe joint showing a state after the connection pipe is completely inserted. It is a half notched cross-sectional view of the same plug-in type pipe joint showing a state before the connecting pipe is inserted. It is a half notched cross-sectional view of the same plug-in type pipe joint showing a state during the insertion of the connecting pipe. It is a half notched cross-sectional view of the plug-in type pipe joint showing a state in the middle of further insertion of the connecting pipe. It is a perspective view of the damage prevention sleeve of the plug-in type pipe joint. It is a top view of the color of the plug-in type pipe joint. It is a front view of the same color. It is sectional drawing of the same color. It is a half notched sectional view showing another embodiment of the seal ring of the plug-in type pipe joint. It is a half notched cross-sectional view of a conventional plug-in type pipe joint.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plug-in type pipe joint 2 Joint main body 3 Detachment member 4 Elastic member 5 Seal ring 5a Ring main body 5b Seal protrusion 7 Scratch prevention sleeve 7a Seal ring holding | maintenance cylinder part 7b Connection pipe end part receiving cylinder part 11 Connection pipe 12 Receptacle Part 13 Tapered surface 24 Concave groove

Claims (5)

In the plug-in type pipe joint in which the end of the connecting pipe is inserted into the receiving part of the joint body having the receiving part,
A seal ring that is housed in the joint body and is in close contact with the outer peripheral surface of the connection pipe; and a scratch-preventing sleeve that is disposed on the inner diameter portion of the seal ring and can be fitted on the end of the connection pipe. The scratch-preventing sleeve is pushed out from the seal ring by being pushed toward the inside of the joint body at the end of the connecting pipe as the connecting pipe is inserted to a predetermined length.
The seal ring is formed to have a ring body and an elastically deformable annular seal protrusion projecting radially inwardly of the ring body, and the inner diameter of the seal protrusion in the free state is It has a smaller dimension than the outer diameter,
The plug-type pipe joint according to claim 1, wherein the seal projecting piece of the seal ring is expanded in diameter as the damage prevention sleeve comes out and is in close contact with the outer peripheral surface of the connection pipe.   The plug-in type pipe joint according to claim 1, wherein a retaining member that engages with an outer peripheral surface of the connection pipe is housed inside the joint body.   The scratch-preventing sleeve is connected to the seal ring holding cylinder portion that holds the seal ring on the outer periphery and the rear end side of the seal ring holding cylinder portion, and has an inner diameter larger than the outer diameter of the connection pipe. The plug-in type pipe joint according to claim 1 or 2, wherein the plug-in pipe joint is formed in a shape having a connecting pipe end receiving tube portion that can be fitted onto the end of the connecting pipe.   The plug-in type pipe joint according to claim 3, wherein a concave groove into which a seal protrusion of the seal ring in a free state is fitted is formed on an outer periphery of the seal ring holding cylinder portion. An elastic member that presses and urges the retaining member toward the inner periphery of the receiving portion is accommodated between the seal ring and the retaining member in the joint body, and the inner periphery of the receiving portion. The taper surface which adds a moving action to the retaining member in the radially inward direction by contact of the retaining member is formed in a constricted shape toward the outside of the receiving portion. The plug-in type pipe joint according to claim 1.

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