JP2010007820A - Pipe joint for plastic resin pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To connect a pipe in a single operation only by fitting a connection pipe end into a pipe joint and manually tightening a cap, and to prevent co-rotation of the pipe in turning and screwing of the cap. <P>SOLUTION: A joint body 8 is covered and screwed on an inner core 9 having a water passing hole H9 on an inner periphery and an O ring 4 on an outer periphery while having a layer of a space dg, the cap 3 encapsulating a diameter reduction fixing ring 5, an auxiliary ring 6 and a diameter reduction fitting ring 7 is temporarily screwed to an end of the joint body 8, the plastic resin pipe 12 is fitted into the space dg in the form of covering the inner core 9 from the inside of the cap 3, and the cap 3 is turned and advanced, and thereby, the diameters of the fixing ring 5 and the fitting ring 7 are reduced so as to press an outer peripheral surface 12c of the pipe 12, and the plastic resin pipe 12 is water-tightly pressed, and nonslip fixing retention can be achieved. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pipe joint for connecting a plastic resin pipe of a water supply pipe or a hot water supply pipe.

Conventionally, cast iron pipes and steel pipes have been used for water supply and hot water supply pipes, but in recent years, polyethylene, crosslinked polyethylene, polybutene, ethylene, etc. have been used in view of corrosion resistance, earthquake resistance, hygiene, workability and cost. Octene. Pipes molded from plastic resins such as copolymers have come to be used as piping for water supply and hot water supply, floor heating, and heat medium for road heating in detached houses, apartment houses, industrial buildings, etc. It was.
Therefore, the joints of Conventional Examples 1 and 2 have been proposed as pipe joints effective for connecting plastic resin pipes.

10A and 10B are pipe joints of Conventional Example 1 cited as Patent Document 1. FIG. 10A is a side sectional view of a state before connection, and FIG. 10B is a side sectional view of a connection state.
That is, the pipe joint of Conventional Example 1 (FIG. 10) is composed of a joint body, a split ring, and a cap nut. As shown in FIG. 10 (A), the joint body has a male thread having a threaded surface on the outer peripheral surface. An inner core portion protrudes from the tube portion, and a locking notch for holding the inner peripheral surface of the plastic tube is disposed over the entire length on the outer peripheral surface of the inner core portion.

In addition, the split ring to be fitted to the outer peripheral surface of the plastic pipe is provided with a crack portion for reducing the diameter, and a protrusion is provided on the inner peripheral surface, and the outer peripheral surface provided with a tapered surface portion on the outer end portion. In order to reduce friction, a fluororesin coating layer is formed.
In addition, the cap nut is provided with a female thread portion for screwing onto the outer periphery of the male screw pipe portion on the front inner peripheral surface, and a tapered surface portion for reducing the diameter of the split ring on the rear inner peripheral surface. The taper surface portion is formed with a fluororesin coating layer.

  When connecting the plastic pipe to the joint body, as shown in FIG. 10 (A), a cap nut is fitted on the outer periphery of the connecting end of the plastic pipe, and then a split ring is fitted, as shown in FIG. 10 (B). The plastic pipe connecting part is covered and fitted to the inner core part of the joint body, the tip of the plastic pipe is brought into contact with the proximal end of the inner core part, and then the cap nut is screwed forward and fastened to the joint body. While the nut pushes the split ring to the proximal end of the inner core portion, the tapered surface of the cap nut pushes the compression ring and compresses the diameter of the plastic tube, the notch portion of the inner core portion located on the inner peripheral surface, It is clamped and held by the protrusions of the split ring located on the outer peripheral surface.

11A and 11B are explanatory diagrams of Conventional Example 2 cited as Patent Document 2, in which FIG. 11A is a sectional view of a plastic pipe fastened state, and FIG. 11B is an enlarged view of a main part of FIG. .
That is, in the conventional example 2, as shown in FIG. 11, the concave portion on the inner peripheral surface of the joint body includes an O-ring, an auxiliary ring, and a locking ring inside the front end, and the outer peripheral surface is reduced in diameter backward. A diameter-reducing pressing ring having a tapered portion is sequentially arranged, and a cap having a tapered portion aligned with the tapered portion of the pressing ring on the inner periphery of the front end is temporarily screwed into the joint body.

When connecting the pipe, the connecting end of the plastic pipe is fitted along the inner peripheral surface of the cap and the inner peripheral surface of the joint body, and the cap is screwed and fastened to the joint body, so that the taper surface of the cap and the pressure ring The pressure ring is advanced and contracted by the cooperative action with the taper surface, and the pressure ring and the locking ring press and secure the outer peripheral surface of the plastic tube, and the O ring is pressed by the advance of the auxiliary ring by the advance of the pressure ring. The outer peripheral surface of the plastic pipe is sealed by the radial displacement of the O-ring, and the outer periphery of the plastic pipe is pressed and held by the locking ring and the pressing ring. The plastic pipe is inserted into the pipe joint. This is a pipe joint that can be connected with a single touch of a plastic pipe by simply rotating the cap.
JP-A-9-229258 Japanese Patent Application Laid-Open No. 11-141765

  In the pipe joint of the conventional example 1 (FIG. 10), the protruding portion of the inner peripheral surface of the split ring bites into the outer peripheral surface of the plastic pipe due to the reduced diameter of the split ring, and the outer peripheral notch of the inner core portion The joint action prevents the plastic pipe from being pulled out, and the joint rotation of the plastic pipe in the fastening action of the pipe joint is applied to the outer peripheral surface of the split ring and the tapered surface of the inner periphery of the cap nut. Although it can be suppressed by sliding between the coating layers of the fluororesin, there is a problem in workability because the cap nut and the split ring are individually attached when the plastic pipe is inserted and joined.

That is, in the pipe joint of the conventional example 1, the split ring is accommodated in the cap nut, and the cap nut is temporarily screwed into the joint main body and is carried to the site.
(I). Disassemble into joint body, split ring and cap nut.
(B). As shown in FIG. 10 (A), the cap nut and the split ring are fitted to the plastic tube with a space therebetween.
(C). A plastic tube is attached to the base end of the inner core part.
(D). Move the split ring to the inner core.
(E). Put the cap nut on the split ring and screw it onto the joint body.
As described above, the connection work is performed in the work steps (A) to (E), and the connection of the pipes is complicated and takes time.

Further, in the pipe joint of the conventional example 1 (FIG. 10), if the cap nut is over-tightened to prevent water leakage, the plastic pipe is over-compressed by a plurality of notches having an inner core surface. The outer peripheral surface is deformed due to over-compression by the split ring ridge, and after a long period of time, creep deformation (deformation that increases with time without applying stress) occurs, and there is a fear that the water stoppage may be lowered. is there.
Further, the connecting portion at the tip of the plastic pipe is deformed by the biting of the plurality of notch portions of the inner core portion with respect to the inner peripheral surface and the biting ridge portion of the split ring with respect to the outer peripheral surface, so that the water leakage preventing state is maintained. Therefore, the plastically deformed connecting portion of the plastic pipe cannot be used for the pipe connection again.

  Further, in the pipe joint of the conventional example 2 (FIG. 11), as shown in FIG. 11 (A), the inner diameter of the cap body includes an O-ring, an auxiliary ring, a locking ring and a pressing ring. This is a one-touch type pipe joint in which a plastic pipe is inserted into a pipe joint that has been temporarily screwed into the joint body, and a cap is screwed and tightened. For this reason, a winding rod is attached, and the pipe cross section of the connecting portion for insertion into the pipe joint is deformed into an elliptical shape.

  Therefore, if the plastic pipe connecting part is inserted into the inner diameter part of the cap at random, the pipe tip collides with the O ring exposed in the inner diameter direction, and the O ring is fitted in the inner peripheral groove of the joint body. In addition, the O-ring has a desired sealing performance when it is connected to a plastic pipe by giving the action of pulling in the inner circumferential direction and dropping the O-ring from the insertion groove, cutting it, or deforming it. There is a fear of leaking water.

If water leakage occurs in the pipe joint, remove the cap, remove the plastic pipe, and once remove the pressing ring, locking ring, auxiliary ring, and O-ring, then reset the pipe joint again, and then remove the plastic pipe. Will be inserted.
Therefore, the connecting operation of the plastic pipe with the winding rod is a difficult operation requiring attention, and the workability is poor.
For example, even if the plastic pipe can be inserted into the pipe joint without damaging the O-ring, the cap tightening work must be performed so that the inner diameter of the cap is in contact with the outer peripheral surface of the plastic pipe, and the final tightening is the pressing ring. By applying the rotation pressing force to the plastic tube, the plastic tube rotates together to cause partial twisting, and the plastic tube is buckled or stress-strained, which impairs the durability of the plastic tube itself.
The present invention provides an innovative one-touch connection type plastic pipe joint that solves or improves the problems of the conventional examples 1 and 2.

  As shown in FIG. 1, for example, the pipe joint for plastic resin pipe according to the present invention has a joint body 8 mounted on the outer periphery of a tubular inner core 9, a cap 3 is attached to the end of the joint body 8, and a pipe 12 Is a pipe joint in which the plastic resin pipe 12 is connected to the inner core 9 through the cap 3 by one-touch operation by turning the cap 3, and the inner core 9 is a pipe having a water passage hole H9. The outer peripheral surface 9c includes a threaded surface 9S for screwing the joint body 8 and an O-ring 4 fitted in the locking groove 9G. The joint body 8 is in the form of a pipe and has an inner periphery. The surface 8d is provided with a screw surface 8S 'for screwing the inner core 9 and the outer peripheral surface 8c is provided with a screw surface 8S for screwing the cap 3, and an end portion of the inner peripheral surface has a tapered surface t8 that expands outward. The cap 3 is provided on the rear surface 3B. A fitting hole H3, a threaded surface 3S that is screwed with a threaded surface 8S of the joint body at the front part of the inner peripheral surface, a tapered surface t3 that is contracted outwardly at the rear part of the inner peripheral surface, and the joint body The fixing ring 5 having the tapered surface t5 that matches the tapered surface t8 on the outer periphery and the slit 5G for reducing the diameter, the auxiliary ring 6, and the tapered surface t7 that matches the tapered surface t3 of the cap are provided on the outer periphery. Then, the engagement ring 7 provided with the slit 7G for diameter reduction is fitted and contained, and the plastic resin pipe 12 is inserted into the gap dg between the inner core 9 and the joint body 8 from the insertion hole H3 of the cap 3. When the cap 3 is screwed and fastened, the fixing ring 5 and the locking ring 7 are reduced in diameter, and the plastic resin pipe 12 is pressed against the outer peripheral surface 9c of the inner core 9 in a watertight manner.

  In this case, although the material of each member which comprises a pipe joint is not ask | required, since it will produce problems, such as rust and a metal elution, if it is made of gunmetal or brass, a plastic resin material is preferable. The joint body 8 and the inner core 9 are molded articles of polyetherimide resin (trade name: Ultem resin), and the fixing ring 5, the auxiliary ring 6 and the locking ring 7 are molded of polyphenylene oxide resin (trade name: Noryl resin). It is a product.

  Further, the gap dg between the outer peripheral surface 9c of the inner core 9 and the inner peripheral surface 8d of the joint body 8 may be of a size that allows the plastic resin pipe 12 to be inserted. The formation of the gap dg is as shown in FIG. The joint body inner peripheral surface 8d may be smooth and may be formed by the diameter-expanded step portion dg of the inner core outer peripheral surface 9c. The inner core outer peripheral surface 9c may be formed as a smooth surface, or although not shown, a step protrusion for forming the gap dg may be disposed from the joint main body inner peripheral surface 8d and the inner core outer peripheral surface 9c. The formation of the gap dg may be appropriately selected and determined from the production surface of the pipe joint.

The plastic resin pipe 12 that employs a pipe joint is preferably a flexible plastic pipe, and is typically made of ethylene. Octene. It is made of a copolymer (PE-RT) resin.
The O-ring 4 is typically a circular ring with a 1.9 mm thickness of JISB2401 nitrile rubber having excellent wear resistance and heat resistance. The plastic resin pipe 12 having an outer diameter R12 having a nominal diameter of 13 mm of 17 mm and an inner diameter R12 ′ of 13 mm has a tolerance of ± 0.15 mm, so the thickness is 1.9 mm. The O-ring 4 may be configured to protrude 0.5 mm from the outer peripheral surface 9c of the inner core 9 having an outer diameter R9 'of 12.6 mm.
Since the O-ring 4 corresponds to the tolerance of the diameter of the plastic resin pipe 12 with sufficient sealing performance, typically, two O-rings are arranged, and each O-ring 4 is within the pressing area of the fixing ring 5. Arrangement is sufficient.

In addition, the inner diameters R5 ′ and R7 ′ in the free state of the fixing ring 5 and the locking ring 7 acting to reduce the diameter are the inner diameters in which the outer diameter R12 (standard: 17 mm) of the plastic resin pipe 12 can be loosely fitted together with the auxiliary ring 6. (Standard: 17.6 mm) The width of the taper surface t5 and the slit 5G of the fixing ring 5 and the width of the taper surface t7 and the slit 7G of the locking ring 7 are reduced by the diameter of the fixing ring 5 and the locking ring 7. Thus, the plastic resin pipe 12 may be set to a relational dimension that allows watertight pressing to the outer peripheral surface 9c of the inner core 9.
The relational structure between the taper surface t5 of the fixing ring 5 and the taper surface t8 of the joint body 8 is such that no excessive pressure is applied to the outer peripheral surface 12c of the plastic resin pipe 12 of the fixing ring 5, that is, the joint body inner periphery. It is preferable that the stopper surface st of the surface 8d has a structure that defines the forward movement of the fixing ring 5.

  Accordingly, the plastic resin pipe 12 is connected to the pipe joint of the present invention by inserting the pipe 12 through the insertion hole H3 at the outer end (rear end) of the cap as shown in FIG. Passes through the holes H7, H6, H5 for insertion with the retaining ring 7, the auxiliary ring 6 and the fixed ring 5 that are held, and passes through the clearance between the outer peripheral surface 9c of the inner core 9 and the joint with the outer peripheral surface 9c of the inner core 9 The cap 3 is screwed forward on the joint body 8 just by manually inserting the cap 3 and inserting the cap 3 into the innermost surface 8d of the inner peripheral surface 8d. The diameter of the pipe 12 is reduced by the cooperative action of the tapered surface t5 of itself and the tapered surface t8 of the joint body 8, the inner peripheral surface 12d of the pipe 12 is pressed against the O-ring 4 on the outer periphery of the inner core, and is watertight pressed. Stop ring 7 also has its own taper The diameter of the pipe 12 is reduced by the cooperative action of the t7 and the taper surface t3 of the cap 3, the inner peripheral surface 12d of the pipe 12 is pressed against the outer peripheral surface 9c of the tip of the inner core 9, and the pipe joint of the plastic resin pipe 12 by the one-touch method. Connection fastening to can be performed.

Due to the presence of the inner core 9, even a plastic resin pipe 12 with a curl is inserted in a perfect circle, and even if the pipe tip collides with the O-ring protrusion, the tip of the pipe 12 is The O-ring 4 is slid on the O-ring 4 without causing stress to expand the elastic diameter of the O-ring 4 and pulled out from the locking groove 9G, so that the O-ring 4 is not deformed or damaged.
Further, at the initial fastening stage of the cap 3, the forward movement of the fixing ring 5 and the locking ring 7 by the sliding rotation with respect to the outer peripheral surface 12 c of the pipe 12 by the rotation of the cap 3 is fixed by the intervention of the auxiliary ring 6. Contact cooperation between the slit 5G of the ring 5 and the slit 7G of the locking ring 7 is broken, and the pipe 12 proceeds without twisting.

At the stage where the fixing ring 5 generates pressure friction with the outer peripheral surface 12 c of the pipe 12, the fixing ring 5 increases the pressing friction force between its own tapered surface t 5 and the tapered surface t 8 of the joint body, and the pipe of the fixing ring 5. The fixing ring 5 does not rotate around the pipe 12 due to an increase in frictional force due to the reduced diameter contact with the inner peripheral surface 12d.
At the stage where the diameter of the locking ring 7 is also reduced and the pipe 12 is pressed, the slit 7G of the locking ring bites into the outer peripheral surface 12c of the pipe 12 and the fixed ring 5 that presses the pipe 12 without rotation. The rotation is suppressed by the frictional force via the auxiliary ring 6, and when the cap 3 is finally screwed, the fixing ring 5 and the locking ring 7 do not rotate and only press the pipe 12 against the inner core 9. The plastic resin pipe 12 can be tightened and connected by a pipe joint without causing buckling or twisting due to co-rotation at the connection portion.

The diameters of the fixing ring 5 and the locking ring 7 are reduced by the biting of the diameter-reducing slits 5G and 7G into the outer peripheral surface 12c of the plastic resin pipe. As a result, the pipe 12 is prevented from being pulled out and the water-tight press against the inner core 9 of the pipe 12 is ensured.
For this reason, the pipe joint of the present invention is a simple one-touch connection fastening operation, but the joint portion of the plastic resin pipe 12 does not cause a co-rotation phenomenon, and the O-ring 4 is displaced and damaged. In addition, it is possible to perform reliable watertight pressing and reliable pipe fixing and holding at two front and rear portions of the connection portion.

Further, in the present invention, as shown in FIG. 1A, the inner core 9 includes a plurality of O-rings 4, and when the cap 3 is screwed and fastened, the taper surface t5 of the fixing ring 5 and the joint body taper. It is preferable that the fixing ring 5 presses the plastic resin pipe 12 against the O-ring 4 by the cooperative action with the surface t8.
In this case, if a plurality of O-rings 4 are arranged at intervals, the plastic resin pipe inner peripheral surface 12d and the O-ring 4 group constitute a face seal, and the protruding dimension of each O-ring 4 is suppressed. However, typically, the O-ring 4 has a center interval (L9 ′) of 5 mm, and each O-ring 4 is arranged in a form protruding 0.5 mm from the inner core outer peripheral surface 9c.

Further, the fixing ring 5 only needs to have a dimension in which the front-rear direction width (axial width) W5 of the inner peripheral surface 5d covers the site where each O-ring 4 is present. Typically, the width W5 of the fixing ring 5 is 8 mm.
In this case, the fixing ring 5 and the locking ring 7 are required to have a function of preventing the plastic resin pipe 12 from being pulled out (disengaged), so the inner peripheral surface 5d of the fixing ring 5 and the locking ring 7 The inner circumferential surface 7d is preferably provided with a frictional force increasing means such as an uneven surface or a threaded surface.

  Accordingly, in the present invention, since a sealing action surface can be formed by a plurality of O-rings 4, the O-ring 4 is arranged so that the O-ring 4 is inserted and fitted when the plastic resin pipe 12 is covered and fitted to the inner core 9. Even if the projection is small (standard: 0.5 mm) so as not to become an obstacle, it is possible to obtain a complete watertight pressing action against the plastic resin pipe 12 by the fixing ring 5, and it is easy to insert the plastic resin pipe 12 into the pipe joint. Thus, it is a one-touch type pipe joint that can be connected and fastened only by manually rotating the cap 3, and there is no fear of water leakage or fear of pulling out.

In the present invention, it is preferable that all members constituting the pipe joint are made of a plastic resin, and at least the inner core 9, the joint body 8, and the cap 3 are made of a transparent plastic resin.
In this case, being transparent means transparent or colored translucent, and means that the back side (inner side) component (member) can be seen through.
Further, since the O-ring 4 is a member on the inner side of the plastic resin pipe, if the O-ring 4 is black, it can be visually observed from the outside through the colored plastic resin pipe 12.

Accordingly, at the time of connecting the plastic resin pipe 12 by the pipe joint, whether the tip of the plastic resin pipe 12 is properly fitted to a predetermined position, whether each O-ring 4 is maintained in an appropriate state, or whether the fixing ring 5 is in an appropriate state , Etc. can be visually observed by an operator, and fastening work is facilitated.
The conventional water supply pipes and hot water supply pipes are the same color, the cross-linked polyethylene pipes are translucent and the polybutene pipes are cream-colored. High flexibility, ethylene. Octene. If a water / hot water supply pipe made of copolymer resin is adopted, the water supply pipe is white and the hot water supply pipe is pink.

Further, in the present invention, as shown in FIG. 6, the fixing ring 5 has an axial width (front-rear direction width) W5 that covers a plurality of O-ring 4 regions, and the inner peripheral surface 5d has It is preferable to provide a plurality of circumferential grooves 5G ′.
Since the O-ring 4 is typically arranged with two intervals of 5 mm, the axial dimension W5 of the fixing ring 5 may be 8 mm.
Further, the circumferential groove 5G ′ of the inner peripheral surface 5d only needs to have a function of holding and holding (preventing pull-out) with respect to the plastic resin pipe outer peripheral surface 12c, and the width, depth, and interval of the groove 5G ′ are as follows. It may be determined appropriately according to the target plastic resin pipe 12, but typically, as shown in FIG. 6 (B), two inner circumferential grooves having a depth of 0.3 mm and a width of 0.3 mm are provided in the front and rear, 5 mm. Arrange at intervals.

Accordingly, if the fixing ring 5 is reduced in diameter with respect to the outer peripheral surface 12c of the plastic resin pipe 12 to generate a pressing action, the outer peripheral surface 12c of the plastic resin pipe 12 is microscopically compressed and deformed. As a result, the groove 5G ′ bites into the groove 5G ′ and the gripping force of the fixing ring 5 on the resin pipe 12 increases.
The plastic resin pipe 12 is pressed by the fixing ring 5 so that the inner peripheral surface 12d is pressed by the plurality of protruding O-rings 4 and the outer peripheral surface 12c bites into the plurality of grooves 5G ′. Will give the plastic resin pipe 12 a water-tight sealing action and a pull-out preventing action by a surface action, and will perform a strong water-tight pressing and a strong locking and holding action.

In the present invention, as shown in FIG. 7, the auxiliary ring 6 includes an outer peripheral surface 6c of the front cylindrical portion and a tapered surface t6 whose diameter is reduced rearward from the outer peripheral surface 6c of the cylindrical portion. It is preferable that the front surface 6F having a large area is in contact with the fixing ring 5 and the rear surface 6B having a small area is in contact with the locking ring 7.
In this case, the auxiliary ring 6 typically has a thickness (axial width) W6 of 2 mm, an outer diameter R6 of a fixed ring outer diameter R5 (standard: 27.6 mm), and a locking ring outer diameter R7. The diameter of the insertion hole H6 is slightly smaller than (standard: 27.6 mm). The diameter of the insertion hole H6 is the same as the diameter of the insertion hole H5 of the fixing ring 5 (standard: 17.6 mm) and the locking ring. 7 is slightly larger (standard: 18 mm) than the diameter of the insertion hole H7 (standard: 17.6 mm).

  Accordingly, the auxiliary ring 6 is loosely fitted to the plastic resin pipe 12 together with the fixing ring 5 and the locking ring 7 in the initial stage of fastening and advancing the cap 3 of the pipe joint, so that the tapered surface t7 of the locking ring 7 is obtained. Is subjected to frictional rotation of the cap taper surface t3, and under the rotation of the locking ring 7, the auxiliary ring 6 and the fixing ring 5 in contact with the front and rear surfaces, and for the diameter reduction of the fixing ring 5 and the locking ring 7. After sliding on the plastic resin pipe outer peripheral surface 12c while preventing the slits 5G and 7G from being caught, the fixing ring 5 is not present after the taper surface t5 of the fixing ring 5 contacts the taper surface t8 of the joint body 8. It rotates and contracts to enter the pressing action on the pipe 12.

At this stage, the auxiliary ring 6 is subjected to the forward action of the cap 3 in a pressure-contact state between the fixing ring 5 and the locking ring 7, but the auxiliary ring 6 has a large area fixed ring contact with the front surface 6F. Due to the difference in frictional force transmission caused by the difference in area between the contact surface and the small-area locking ring contact surface of the rear surface 6B, the locking ring 7 also becomes free from frictional force from the auxiliary ring 6 and the pipe 12. The plastic resin pipe 12 is pressed together with the fixing ring 5 without rotating together with the cap 3, that is, without imparting a twisting action to the plastic resin pipe 12 due to the frictional force generated by the reduced diameter pressing.
For this reason, the interposition of the auxiliary ring 6 allows the front fixing ring 5 and the rear locking ring 7 to have a predetermined pressing locking action without causing the plastic resin pipe 12 to twist or buckle together. Play.

The plastic resin pipe 12 has the fixing ring 5 to press and seal the O-ring 4 and prevent the pull-out, and the locking ring 7 to seal by pressing the inner core outer peripheral surface 9c. As a result, the locking action for preventing pull-out is received.
Therefore, the pipe joint of the present invention can be engaged with the front and rear fixing rings 5 without inserting a predetermined plastic resin pipe 12 and manually rotating the cap 3 without giving a joint action to the connection pipe 12. At two sites with the stop ring 7, the pipe 12 has a sealing action and a pull-out prevention action, and can reliably achieve a leak-proof seal and a pull-out prevention connection without damaging the plastic resin pipe 12 for connection. .

In the present invention, as shown in FIG. 1, the inner core 9 and the joint body 8 are sockets having a symmetrical structure in the longitudinal direction. The cap 3 is fitted from both sides, and the plastic resin pipe 12 is attached from both sides. An insertion connection is preferred.
In this case, as shown in FIG. 1, the joint body 8 and the inner core 9 are prepared in a symmetrical form in the longitudinal direction, and the cap 3 including the fixing ring 5, the auxiliary ring 6, and the locking ring 7 is fitted into the joint 3. When fitted to both ends of the main body 8, the pipe joint can be inserted and connected to the plastic resin pipe 12 from both sides.
Therefore, the symmetrical double-headed socket-type pipe joint is effective as an elongated joint of the plastic resin pipe 12.

Further, according to the present invention, as shown in FIG. 9, the joint body 8 has an elbow shape, and a plastic resin pipe 12 can be connected and fastened to a pipe joint at one end. What provided the screw surface 10S is preferable.
In this case, the joint body 8 may be formed by integrally forming a pipe joint structure in one half and a bent elbow pipe 10 in the other half, and the inner core 9 has a joint body as shown in FIG. What is necessary is just to prepare for the dimension corresponding to this pipe joint structure.
Therefore, if the pipe joint of the present invention is adopted, the plastic resin pipe 12 can be connected to one end by a one-touch operation, and the faucet 13 as a terminal device or a socket (not shown) can be connected to the other end. It is effective for the pipe construction which adopted No.12.

  In the pipe joint of the present invention, the plastic resin pipe 12 is inserted into the gap dg between the joint body 8 and the inner core 9 along the outer periphery of the inner core 9 from the cap 3 fitted to the end of the joint body 8. 3 can be secured to the outer peripheral surface 9c of the inner core 9 by the fixing ring 5 and the locking ring 7 whose diameter of the plastic resin pipe 12 is reduced by simply screwing the joint 3 to the joint body 8 manually. It can be connected to the inner core 9 in a watertight manner without fear of pulling out.

  And even if the plastic resin pipe 12 is in a state with a curl hook, that is, in a state with a curved hook or an elliptical deformation hook, the insertion into the pipe joint is a covering fit into the inner core 9. The flexible pipe 12 is inserted while being corrected to a perfect circle shape, and smoothly passes over the O-ring 4 disposed on the outer peripheral surface 9c of the inner core 9, so that the O-ring 4 is removed or damaged. Therefore, the pressing of the plastic resin pipe 12 to the outer peripheral surface 9c of the plastic resin pipe 12 by the fixing ring 5 achieves a predetermined watertight pressing.

  Further, the rotational screwing forward action of the cap 3 to the joint body 8 is caused by the auxiliary ring 6 being interposed in the front fixing ring 5 and the rear locking ring 7 which are reduced in diameter by the screwing advancement of the cap 3. The plastic resin pipe 12 can be firmly and watertightly attached to the outer peripheral surface 9c of the inner core 9 without giving twist to the plastic resin pipe 12, and the plastic resin pipe 12 is Since it is subjected to pressure contact and locking action at the front and rear two parts of the fixing ring 5 part of the part and the locking ring part 7 of the rear part, it is highly reliable by a one-touch operation by simply tightening the cap 3 by manual rotation. Complete, watertight fastening is possible.

An embodiment will be described as a socket-type pipe joint 1 applied to a plastic resin pipe having a nominal diameter 13A of JIS standard, an outer diameter of 17 mm, and an inner diameter of 13 mm.
FIG. 1 (A) is a longitudinal sectional view of the socket-type pipe joint 1. In FIG. 1 (A), the right pipe joint is in a state where the pipe 12 is connected, and the left pipe joint is just before the pipe insertion. FIG. 1B is a side view of FIG. 1A.
As shown in FIG. 1 (A), the socket-type pipe joint 1 has a joint body 8 screwed onto the outer periphery of an inner core 9 having a water passage hole H9, and a fixing ring 5, an auxiliary ring 6 and a locking ring 7 are attached. The cap 3 included in the fitting is screwed onto the outer periphery of the joint body 8.

[Inner core 9 (FIG. 4)]
4A and 4B are explanatory views of the inner core 9, wherein FIG. 4A is a longitudinal side view, and FIG. 4B is a side view.
The inner core 9 is transparent, made of polyetherimide resin (trade name: Ultem resin), and is a pipe-shaped molded product having a general thickness of 3 mm. The total length L9 is 98 mm, and the inner diameter R9 ″ is the water passage hole H9. 6.7 mm, outer diameter R9 ′ is 12.6 mm, and the outer periphery of the central portion of the cylinder has a bulging thick portion with a diameter R9 of 20 mm. The peripheral surface of the bulging thick portion has a length of 18 mm. And a step d9 having a height of 3.65 mm is provided from the inner core outer peripheral surface 9c to the bulging screw surface 9S.
Further, a taper surface t9 having a 1/3 gradient for facilitating insertion into the plastic resin pipe 12 is attached to the outer periphery of both ends, and an O-ring is provided at an intermediate position between the step portion d9 and the tip of the outer peripheral surface 9c. In this example, two locking grooves 9G having a width of 1.9 mm and a depth of 1.4 mm for inserting 4 are arranged with a distance L9 ′ of 5 mm.

[Fitting body 8 (Fig. 2)]
2A and 2B are explanatory views of the joint body, in which FIG. 2A is a longitudinal side view, FIG. 2B is an end view, and FIG. 2C is a side view.
Like the inner core 9, the joint body 8 is a pipe-shaped molded product made of polyetherimide resin (product surface: Ultem resin) with a general thickness of 4 mm. Caps 3 are provided on both sides of the outer peripheral surface 8c. A screw thread 8S is arranged in a form in which a thread thread protrudes from the outer peripheral surface 8c, and a metric fine screw (JISB0207) with a short screw interval for screwing so as not to loosen, and at the center of the outer peripheral surface 8c. When the inner core is attached, a flat surface 8f for contacting a jig (wrench or the like) that prevents the joint body 8 from rotating is arranged symmetrically on the front and back, and the inner peripheral surface 8d A threaded surface 8S ′ for screwing the core 9 is arranged in a protruding form from the inner peripheral surface 8d.

Further, at both ends of the inner peripheral surface, a fitting hole H8 ′ having a length L8 ′ with which the fixing ring 5 is fitted is 7 mm is arranged in an outwardly expanded form through a stopper surface st having a stopper function, The inner peripheral surface that expands outward from the fitting hole H8 ′ is defined as a tapered surface t8.
The tapered surface t8 was formed with a length L8 ′ of 7 mm, an inner end diameter of 21.6 mm, and an outer end diameter of 22.4 mm.
The dimensional relationship of the joint body 8 is that the outer diameter R8 is 26.4 mm, the total length L8 is 73 mm, the center is provided with an insertion hole H8 with a diameter R8 ′ of 19.6 mm, and the length of the inner peripheral surface 8d. In the center portion, a screw surface 8S ′ for inner core screwing is arranged in a projecting form from the inner peripheral surface 8d over a length of 18 mm, and the screw surfaces 8S on both sides of the outer peripheral surface have a length (L8 ′) from the tip. ) 7 mm was placed and placed in a range of 12 mm in length.

[Cap 3 (Fig. 3)]
3A is a rear view of the cap 3, and FIG. 3B is a longitudinal side view.
The cap 3 is a transparent polyphenylene oxide resin (trade name: Noryl resin) molded product, and has a pipe shape as shown in FIG. 3A. The outer peripheral surface 3c has an anti-slip for manual rotation. The longitudinal projections 3P are arranged in a hexagonal shape, and the rear surface 3B is provided with a circular insertion hole H3 having a diameter R3 ″ of 28 mm for inserting the plastic resin pipe 12, slightly more than the front surface 3F (standard) 1 mm) A metric fine screw 3S (JISB0207) for screwing the joint body 8 is provided on the inner peripheral surface 3d from the inner side over 12 mm in the front and rear, and the tapered surface t7 of the locking ring 7 is in contact with the inner side of the rear surface 3B. This is provided with a tapered surface t3.

  The pipe-shaped cap 3 has a general thickness of 3.5 mm, a length L3 of 38 mm, and a diameter R3 of the cylindrical outer peripheral surface 3c of 35 mm. The outer peripheral surface 3c has a width of 5 mm and a protruding height d3 of 1. 5 mm lengthwise projections 3P are provided in a hexagonal shape at equal intervals, the diameter R3 ′ of the insertion hole H3 in the center of the rear surface 3B is 17.6 mm, and the thread surface 3S in the front part of the inner peripheral surface 3d has a width of 12 mm. This is a metric fine thread surface with a pitch interval of 1.5 mm and a height of 0.8 mm. The tapered surface t3 on the rear surface of the inner peripheral surface is a 1/4 gradient from the inner peripheral diameter (R3 ″) of 28 mm, and the rear is 8 mm in length. It is a truncated conical surface that is reduced in diameter.

[O-ring 4 (Fig. 5)]
5A is a front view of the O-ring, and FIG. 5B is a vertical side view of the O-ring.
The O-ring 4 is a sealing member that is fitted in and attached to the locking groove 9G having a width of 1.9 mm and a depth of 1.4 mm of the inner core 9, and is a thick nitrile rubber (JISB2401) that has excellent wear resistance and heat resistance. This is a circular ring with a cross-section having a width W4 of 1.9 mm and an inner diameter R4 of 9.8 mm, and is colored black (colored with a stock solution).

[Fixing ring 5 (FIG. 6)]
6A and 6B are explanatory views of the fixing ring 5, wherein FIG. 6A is a side view, FIG. 6B is a longitudinal side view, and FIG. 6C is a front view.
The fixing ring 5 is a molded product made of polyphenylene oxide resin (trade name: Noryl resin), and the overall shape is a diameter for inserting the plastic resin pipe 12 at the center as shown in FIG. R5 ′ is provided with an insertion hole H5 of 17.6 mm, a front-rear width W5 is 8 mm, a rear end is provided with a flange 5E having a diameter R5 of 27.6 mm and a thickness of 1 mm, and an outer peripheral surface 5c is provided with a rear A tapered surface t5 whose diameter is reduced from the flange 5E at the end to the front end is provided so as to be aligned with the tapered surface t8 at the inner periphery of the distal end of the joint body 8.

  A slit 5G having a small width (standard: 2 mm) is provided to reduce the diameter when external pressure is applied to the fixing ring 5, and the inner peripheral surface 5d is reduced in diameter to the plastic resin pipe 12. When the outer peripheral surface 12c is pressed, a circular groove (standard: depth 0.3 mm, width 0.3 mm) for the plastic resin pipe outer peripheral surface 12c to bite in by elastic deformation is formed on the front of the inner peripheral surface 5d. It is arranged at the rear.

[Auxiliary ring 6 (FIG. 7)]
7A and 7B are explanatory views of the auxiliary ring 6, in which FIG. 7A is a side view, FIG. 7B is a rear view, and FIG. 7C is a longitudinal side view.
The auxiliary ring 6 is a non-reducing thin flat plate ring interposed between the reducing ring 5 and the locking ring 7, and is a molded product made of polyphenylene oxide resin (trade name: Noryl resin). It is.
As shown in FIG. 6C, the overall shape is provided with an insertion hole H6 having a thickness (width in the front-rear direction) W6 of 2 mm, an outer diameter R6 of 26.5 mm, and a diameter R6 ′ of 18 mm at the center. The outer peripheral surface 6c is provided with a tapered surface t6 that is reduced in diameter toward the rear surface 6B, and contacts the front surface of the locking ring 7 with respect to the area of the front surface 6F that contacts the flange 5E of the fixing ring 5. The area is small.

[Locking ring 7 (FIG. 8)]
8A and 8B are explanatory views of the locking ring 7, wherein FIG. 8A is a side view, FIG. 8B is a rear view, and FIG. 8C is a longitudinal side view.
The locking ring 7 is a molded product made of polyphenylene oxide resin (trade name: Noryl resin). As shown in FIG. 8 (C), the locking ring 7 has an axial (front-rear) width W7 of 9 mm and a front diameter R7. The outer peripheral surface 7c is aligned with the tapered surface t3 of the inner periphery of the rear portion of the cap 3 with the tapered surface t7 having a diameter reduced to the rear surface through a horizontal portion 7W having a small width (standard: 1.7 mm) on the front surface. Arranged.

In the center, an insertion hole H7 having a diameter R7 ′ of 17.6 mm is arranged for insertion of the plastic resin pipe 12, and the locking ring 7 is provided on the inner peripheral surface 7d in the same manner as the inner peripheral surface of the fixing ring 5. However, when the plastic resin pipe 12 was tightened from the outer surface, a small groove (standard: depth 0.3 mm, width 0.3 mm) for biting into the outer peripheral surface 12c of the plastic resin pipe was arranged at the front and rear.
Further, as shown in FIG. 8B, if pressure is applied to the peripheral surface of the locking ring 7, that is, if the tapered surface t3 of the cap 3 presses the tapered surface t7, a small width for reducing the diameter ( Standard: 2 mm) slits 7G are arranged in the form of split grooves in the axial direction.

(Use of pipe fittings)
In the factory, as shown in FIG. 1A, the pipe joint has a locking groove 9G (width: 1.G) arranged in a cylindrical portion of the inner core 9 whose outer diameter R9 ′ of the cylindrical outer peripheral surface 9c is 12.6 mm. 9 mm, depth 1.4 mm) and a black O-ring 4 (diameter 1.9 mm, inner diameter 9.8 mm) is fitted, and then the thread surface 8S ′ at the center of the inner peripheral surface 8d of the socket joint body 8 Then, the thread surface 9S of the outer peripheral surface central portion of the socket inner core 9 is screwed and fastened, and the joint body 8 and the inner core 9 are provided with a gap dg for inserting a pipe on both sides.
In this case, workability is good because the inner core 9 is screwed and fastened with the flat surfaces 8f on both sides sandwiched between the outer peripheral surfaces 8c of the joint body.

Next, into the cap 3, as shown in the left half of FIG. 1A, the tapered surface t7 of the locking ring 7 is the tapered surface of the cap 3 in the order of the locking ring 7, the auxiliary ring 6, and the fixing ring 5. In response to t3, the auxiliary ring 6 is fitted and contained with the rear surface 6B on the tapered surface t6 side as the locking ring 7 side, and the fixing ring 5 with the tapered surface t5 on the front surface, and the cap 3 is attached to the end of the joint body 8. As shown in the left end state of 1 (A), it is temporarily screwed and carried into the construction site.
When the cap 3 is temporarily screwed into the joint body 8, the insertion holes of the locking ring 7, the auxiliary ring 6, and the fixing ring 5 are aligned with the cap insertion hole.

At the construction site, as shown on the left side of FIG. 1 (A), as a plastic resin pipe 12, ethylene. With a nominal diameter 13A (outside diameter R12: 17 mm, inside diameter R12 ′: 13 mm) of JIS standard is used. Octene. From the insertion hole H3 (hole diameter: 17.6 mm) at the rear end of the cap 3, the copolymer (PE-RT) resin pipe 12 is connected to each locking ring 7 (hole diameter: 17.6 mm) and auxiliary ring 6 (hole diameter: 18 mm) and the fixing ring 5 (hole diameter: 17.6 mm) are inserted into the outer periphery of the inner core 9 in a covering form, and the gap dg is inserted to the step portion d9.
In this case, since the cap 3, the joint body 8, and the inner core 9 are transparent, the plastic resin pipe 12 does not cause any displacement in the O-ring 4 and is visually confirmed to be inserted into the step portion d9. I can do it.

Next, the cap 3 is rotated by hand, and the joint body 8 is screwed forward until it feels hard.
Then, as the cap 3 rotates forward with respect to the joint body 8, the locking ring 7, auxiliary ring 6, and fixing ring 5 included in the cap 3 also move forward and loosely fit on the outer periphery of the plastic resin pipe 12. The fixing ring 5 and the locking ring 7 have a taper surface t5 that is pressed by the taper surface t8 of the joint body, and the locking ring 7 has a taper surface t7 that is a taper surface at the rear end of the cap 3, respectively. Due to the pressing action at t3, both diameters are reduced and the outer peripheral surface 12c of the plastic resin pipe 12 is pressed.

In this case, when the cap 3 is fully tightened, as shown on the right side of FIG. 1A, the fixing ring 5 presses the outer peripheral surface of the arrangement area of the O-ring 4 and the inner peripheral surface of the plastic resin pipe 12. 12d and the inner peripheral surface 9d of the inner core 9 are completely watertight pressed, and the locking ring 7 also achieves watertight pressing of the inner peripheral surface 12d of the plastic resin pipe to the inner peripheral surface 9d of the inner core 9, and at the same time The groove 5G 'and slit 5G on the inner peripheral surface 5d of the fixing ring 5 and the groove 7G' and slit 7G on the inner peripheral surface 7d of the locking ring 7 are formed on the outer peripheral surface 12c of the flexible plastic resin pipe 12. It exerts a biting action and also prevents the plastic resin pipe 12 from being pulled out from the pipe joint.
That is, in the socket type pipe joint shown in FIG. 1, the pipe 12 can be connected with one touch by inserting the pipe 12 from both sides and rotating and tightening the cap 3, and the watertight press and pull-out prevention holding are achieved. Can be implemented in two front and rear parts, and pipe connection that can guarantee safety can be achieved.

[Modification (FIG. 9)]
FIG. 9 is an explanatory view in which the pipe joint of the present invention is applied to a faucet connection in the form of an elbow, wherein FIG. 9 (A) is a longitudinal side view and FIG. 9 (B) is a side view.
In this case, as shown in FIG. 9 (A), the other end of the joint body 8 is a bent elbow pipe 10, and the inner core 9, the joint body 8, and the cap 3 are arranged only on one end side of the joint body 8. That is, the socket type pipe joint 1 shown in FIG. 1 is configured to correspond to one end side, and the connecting thread surface 10S is arranged on the inner periphery of the tip of the elbow pipe 10 at the other end according to the fitting to be screwed.
Accordingly, as shown in FIG. 9 (B), the pipe joint 2 is fixed at a predetermined position, and the plastic resin pipe 12 is connected to the joint body 8 at one end by a one-touch operation, and the faucet 13 or the other end is shown. It is possible to screw and fix the socket fitting on the water supply side.

It is explanatory drawing of the socket type pipe joint of this invention, Comprising: (A) is a vertical side view, (B) is a side view. It is explanatory drawing of the coupling main body 8, Comprising: (A) is a vertical side view, (B) is an end view, (C) is a side view. It is explanatory drawing of the cap 3, Comprising: (A) is a rear view, (B) is a vertical side view. It is explanatory drawing of the inner core 9, Comprising: (A) is a vertical side view, (B) is a side view. It is explanatory drawing of the O-ring 4, Comprising: (A) is a front view, (B) is a vertical side view. It is explanatory drawing of the fixing ring 5, Comprising: (A) is a side view, (B) is a vertical side view, (C) is a front view. It is explanatory drawing of the auxiliary | assistant ring 6, Comprising: (A) is a side view, (B) is a rear view, (C) is a vertical side view. It is explanatory drawing of the locking ring 7, Comprising: (A) is a side view, (B) is a rear view, (C) is a vertical side view. It is explanatory drawing which applied this invention to the elbow type pipe joint, Comprising: (A) is a vertical side view, (B) is a side view. It is explanatory drawing of the prior art example 1, Comprising: (A) is a vertical side view of the state before a connection, (B) is a vertical side view of a connection state. It is explanatory drawing of the prior art example 2, Comprising: (A) is a vertical side view of a connection state, (B) is the elements on larger scale of (A).

Explanation of symbols

1 Socket type pipe fittings (pipe fittings)
2 Elbow type pipe fitting (pipe fitting)
3 Cap 3B, 5B, 6B, 7B Rear surface 3c, 5c, 6c, 7c, 8c, 9c, 12c Outer peripheral surface 3d, 5d, 7d, 8d, 9d, 12d Inner peripheral surface 3F, 5F, 6F, 7F Front surface 3P Projection 3S , 8S, 8S ', 9S, 10S Thread surface 4 O-ring 5 Fixing ring 5E Flange 5G, 7G Slit 5G', 7G 'Groove 6 Auxiliary ring 7 Locking ring 7W Horizontal portion 8 Joint body 8f Flat surface 9 Inner core 9G Locking groove 10 Elbow pipe 12 Plastic resin pipe (pipe)
13 Water faucet dg Clearance d9 Stepped portion H3, H5, H6, H7, H8 Insertion hole H8 'Fitting hole H9 Water passage hole t3, t5, t6, t7, t8, t9 Tapered surface st Stopper surface

Claims (7)

  The joint body (8) is mounted on the outer periphery of the tubular inner core (9), the cap (3) is attached to the end of the joint body (8), and the plastic resin pipe (12) is passed through the cap (3). A pipe joint that is inserted into the inner core (9) and is connected to the plastic resin pipe (12) by one-touch rotation of the cap (3). The inner core (9) has a water passage hole (H9). The outer peripheral surface (9c) is provided with a thread surface (9S) for screwing the joint body (8) and an O-ring (4) fitted in the locking groove (9G). The joint body (8) is in the form of a pipe, the inner peripheral surface (8d) has a thread surface (8S ') for screwing the inner core (9), and the outer peripheral surface (8c) has a cap (3 ) A threaded thread surface (8S) is provided, and the inner peripheral surface end portion is a tape that expands outward. The cap (3) has an insertion hole (H3) on the rear surface (3B), and a threaded surface (3S) that engages with the threaded surface (8S) of the joint body on the front surface of the inner peripheral surface. ) At the rear of the inner peripheral surface is provided with a tapered surface (t3) that decreases outwardly, and has a tapered surface (t5) that matches the tapered surface (t8) of the joint body on the outer periphery. A fixing ring (5) having a slit (5G), an auxiliary ring (6), and a taper surface (t7) aligned with the taper surface (t3) of the cap on the outer periphery to reduce the diameter of the slit (7G ) And a plastic resin pipe (12) from the insertion hole (H3) of the cap (3) to the inner core (9) and the joint body (8). Insert into the gap (dg), and fix the ring (5) and lock by screwing the cap (3) A pipe joint for a plastic resin pipe in which the diameter of the ring (7) is reduced and the plastic resin pipe (12) is watertightly pressed to the outer peripheral surface (9c) of the inner core (9).   The inner core (9) includes a plurality of O-rings (4). When the cap (3) is screwed and fastened, the taper surface (t5) of the fixing ring (5) and the joint body taper surface (t8) cooperate. Pipe fitting according to claim 1, wherein the fixing ring (5) presses the plastic resin pipe (12) against the O-ring (4) by action.   The pipe joint according to claim 1 or 2, wherein all members constituting the pipe joint are made of plastic resin, and at least the inner core (9), the joint body (8), and the cap (3) are made of transparent plastic resin. .   The fixing ring (5) has an axial width (W5) having a dimension that covers a plurality of O-ring (4) regions, and a plurality of circumferential grooves (5G ') on the inner peripheral surface (5d). The pipe joint according to any one of claims 1 to 3, further comprising:   The auxiliary ring (6) is a thin plate ring having an outer peripheral surface including an outer peripheral surface (6c) of the front cylindrical portion and a tapered surface (t6) whose diameter is reduced rearward from the cylindrical outer peripheral surface (6c). The pipe joint according to any one of claims 1 to 4, wherein the front surface (6F) having a large area comes into surface contact with the fixing ring (5) and the rear surface (6B) with a small area comes into contact with the locking ring (7).   The inner core (9) and the joint body (8) are in the form of a symmetrical socket in the longitudinal direction, and the cap (3) is fitted from both sides, and the plastic resin pipe (12) is inserted and connected from both sides. The pipe joint according to any one of claims 1 to 5.   The joint body (8) is in an elbow form, and a plastic resin pipe (12) can be connected and fastened to a pipe joint at one end, and a connecting thread surface (10S) is provided on the other end inner surface of the elbow pipe (10). The pipe joint according to any one of claims 1 to 5, which is provided.

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