JPH06201081A - Pipe joint - Google Patents

Abstract

PURPOSE:To provide a pipe joint for connecting synthetic resin pipes and metal pipes using a cap nut without the fear of a screw part being deformed or damaged at the connecting time and without the looseness of the cap nut even with the use for many hours. CONSTITUTION:A protruding part 23 is formed at the contact face 22 of a cap nut 2, and a recessed part is formed at the face, coming in contact with the contact face 22 of the cap nut 2, of the collar part 10 of a pipe joint body 1. After connection, the protruding part 23 is fitted into the recessed part so as to impede the reverse rotation of the cap nut 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint for connecting synthetic resin pipes, metal pipes, etc. used for water supply pipes, hot water supply pipes, etc. The present invention relates to a pipe joint in which a threaded portion is not deformed or damaged by tightening when connecting a pipe or a metal pipe.

[0002]

2. Description of the Related Art Synthetic resin pipes, metal pipes, etc. used for water supply pipes, hot water supply pipes, etc. are designed so as not to be easily separated, for example, as disclosed in Japanese Utility Model Laid-Open No. 61-2291. The method of connecting the ends of the connecting pipes by screw connection through a pipe joint is often used because it is relatively simple and a strong fastening force can be obtained.

The pipe joint used in the above method is
It consists of a pipe joint body, a cap nut, and a connecting cylinder body. The pipe joint body is integrally provided with a cylindrical portion into which one end of one connecting pipe is inserted, and from one end of this cylindrical portion toward the outer peripheral direction. A flange is provided, a male screw is formed on the outer periphery of the cylindrical portion, and a notch is provided so that the tip can be reduced in diameter. Also,
The cap nut has a female threaded portion that is screwed into the male threaded portion of the pipe joint body on the inner circumference of the tip, and has a taper on the inner circumference of the base.

Further, in the connecting cylinder, the male screw portion to which the end portion of the other connecting pipe is screwed, the nut portion to be engaged in the collar portion of the pipe joint body, and the end portion on the opposite side of the male screw portion are guided. It is considered a division. When connecting, packing is attached to the outer peripheral surface of the guide portion of the connecting tube. The connection tube body is incorporated in the pipe joint body by fitting the flange portion of the pipe joint body into the nut portion of the connection tube body from the outside.

When connecting the pipes, one of the connecting pipes is screwed into the female screw portion of the connecting cylinder. Then, the end portion of the other connecting pipe is inserted between the guide portion of the connecting cylinder body and the cylindrical portion of the pipe joint body. The cap nut is externally fitted on the connecting pipe. Next, the female screw part of the cap nut is screwed into the male screw part of the pipe joint body, and the cap nut is tightened until the tip of the cap nut comes into contact with the flange end face of the pipe joint body.

As the cap nut moves toward the pipe joint body side, the tapered portion of the cap nut pushes the tip of the cylindrical portion of the pipe joint body inward, and the notch at the tip of the cylindrical portion contracts.
As a result, the notch at the tip of the cylindrical portion presses the outer surface of the connecting pipe over the entire circumference, and the inner peripheral surface of the connecting pipe is pressed against the packing attached to the outer peripheral surface of the guide portion of the connecting cylinder to form a water blocking structure. , The connection is closed.

By the way, the connection of a pipe such as a hot water supply pipe is made in a narrow and dark place such as a space under the ceiling or under the floor. Therefore, when the cap nut is rotated relative to the pipe joint main body and the tip end face of the cap nut is brought into contact with the end face of the flange portion, it is not possible to visually recognize that the end faces abut.

Therefore, the cap nut is gradually tightened carefully, and the increase in the tightening resistance after the end face of the cap nut comes into contact with the end face of the flange portion of the pipe joint body is manually detected through a tool such as a spanner. Had stopped tightening.

However, since the tightening resistance acting on the tool gradually and continuously rises, an appropriate final tightening time cannot be known, and the end face of the cap nut is in contact with the end face of the flange portion of the pipe joint body. Nevertheless, the cap nut was sometimes tightened further. Due to over-tightening of the cap nut, the screw part may be deformed or damaged, the cap nut may retract from the specified position, the tightening force of the connecting pipe by the cap nut may decrease, and the sealing of the connection part may be perfect. Not
The liquid could leak.

Therefore, in the pipe joint as described above, in order to avoid excessive tightening of the cap nut, an engaging portion is provided on one of the contact surface of the cap nut and the contact surface of the collar portion, and the other is provided on the other. A pipe joint has been proposed in which the engaging portion is provided with a protrusion that can be engaged (Japanese Patent Laid-Open No. 64-65384).

According to this pipe joint, at the time of connection, when the cap nut and the pipe joint main body are relatively rotated to bring both abutting surfaces close to each other, and the desired water-stop structure is obtained, the protrusion is formed. Since the force of engaging with the engaging portion fluctuates greatly, the worker can easily detect the change in the tightening resistance through the tool.

[0012] Then, by judging this time as the proper final tightening position and stopping the tightening of the cap nut, the cap nut and the threaded portion of the pipe joint body are not damaged or deformed, and a reliable seal can be made. The tightening force can be uniform.

[Problems to be Solved by the Invention]

In the above pipe joint, for a while after the pipe is connected, the tip of the cylindrical portion of the pipe joint body, which has been reduced in diameter by the tapered portion of the cap nut, has a force to restore the original diameter. The taper portion of the cap nut is pressed outward by this restoring force, so that the pressing force prevents the cap nut from loosening.

However, due to long-term use, the force with which the tip of the cylindrical portion tries to return to the original diameter is weakened, and the pressing force of the tip of the cylindrical portion against the taper portion of the cap nut disappears, so the cap nut may loosen.

By the way, in the above pipe joint, the contact surface between the flange portion of the pipe joint body and the cap nut is shown in FIG.
As shown in (b), the flange portion 10A is formed in a side surface hexagonal nut shape having a flat portion 101A and a corner portion 102A on the outer surface, and the engaging portion 12A is formed in the corner portion 10A of the flange portion 10A.
Open in the vicinity of 2A toward the cap nut 2A and outward,
The inner peripheral surface edge 231A of the protrusion 23A and the side edge 23 in the screwing direction
Although the portion surrounded by 2A is formed so as to enter, the side edge 233A on the side opposite to the screwing direction of the protrusion 23A has no place to be locked at the engaging portion 11A. In addition, 3A is a connection cylinder and 5A is a connection pipe.

Therefore, when the cap nut 2A is rotated in the tightening direction, the inner peripheral surface end edge 231A of the projection 23A and the side edge 232A on the screwing direction side engage with the engaging portion 11A to form a large size. Although the resistance force is generated, the resistance force is not generated at all in the opposite rotation, that is, the rotation in the direction in which the cap nut 2A is loosened.

Therefore, if the restoring force of the reduced diameter tip of the cylindrical portion of the joint body 1A disappears, the cap nut 10A may rotate and loosen in the direction opposite to the tightening and screwing direction due to vibration or the like. There was a risk that the water-stopping function would deteriorate, causing water leakage.

In view of the above points, the present invention avoids the excessive tightening of the cap nut and prevents the screw portion from being deformed or damaged, and does not cause the cap nut to loosen even after long-term use. The purpose is to provide a pipe joint.

[0019]

DISCLOSURE OF THE INVENTION The pipe joint of the present invention is a cylindrical portion externally fitted to an end portion of a connecting pipe and having a male screw portion formed on the outer periphery thereof, and an outer peripheral direction projecting from one end portion of the cylindrical portion. A cap nut having a flange portion provided therein and a female screw portion that is screwed into the male screw portion of the pipe joint body is formed on the inner circumference of the end portion, and a taper portion is provided on the inner circumference of the base portion. And a threaded engagement between the female thread of the cap nut and the male thread of the pipe joint body causes the contact surface formed at the tip of the cap nut to be the contact surface formed in the flange portion of the pipe joint body. In a pipe joint in which the outer surface of the connecting pipe fitted in the cylindrical portion of the pipe joint body is pinched by pressing the cap nut inwardly of the taper portion, the cap nut abuts There is a recess on either the surface or the contact surface of the flange of the pipe fitting body. Made is, which projections fit into the recesses in the other are formed, the object can be achieved.

[0020]

When the cap nut and the pipe joint body are relatively rotated at the time of connection so that both contact surfaces come close to each other, the projection fits into the recess when the desired water-stop structure is obtained. Therefore, the force required for tightening is greatly increased, and the force is easily sensed through the tool, and the operator can determine this time as the proper final tightening position.

After the connection, even if the cap nut tries to rotate in the reverse direction due to vibration or the like, the protrusion fits into the recess to prevent the rotation, and the cap nut does not loosen.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show an embodiment of a pipe joint of the present invention. FIG. 1 is a front view, FIG. 2 is a partially cutaway front view showing a state in which pipes are connected, and FIG. Figure,
1A is a sectional view taken along the line III-III in FIG. 1, and FIG. 1B is an enlarged sectional view of an essential part thereof.

As shown in FIGS. 1 to 3, the pipe joint is
It is composed of a pipe joint body 1 and a cap nut 2, and a pair of connection pipes 4 and 5 such as a hot water supply pipe and a water supply pipe are connected using a connection cylinder 3.

The pipe joint body 1 is provided with a cylindrical portion 14 having a male screw portion 15 formed on the outer periphery thereof, and a flange portion 10 integrally projecting from one end of the cylindrical portion 14 in the outer peripheral direction.

A plurality of notches 16 which are long in the axial direction are formed at the tip of the cylindrical portion 14 so that the tip of the cylindrical portion 14 can be reduced in diameter by an external pressing force. The inner diameter of the cylindrical portion 14 is substantially equal to or slightly larger than the outer diameter of the connecting pipe 5. The length of the cylindrical portion 14 is set so that the tip of the cutout portion 16 substantially corresponds to the position of an annular groove 33 provided on the outer periphery of the guide cylinder 31 of the connecting cylinder body 3 described later.

The collar portion 10 is formed, for example, in the shape of a hexagonal nut having a flat portion 101 and a corner portion 102 on the outer peripheral surface, so that a tightening tool such as a spanner can be engaged with the outer surface of the collar portion, or rotated or fixed. It has become. This collar part 1
The open side surface of 0 is formed in a shape that can be externally fitted to the nut portion 32 of the connection cylindrical body 3.

Then, the contact surface 11 of the collar 10 is provided with a recess 12
Are provided at appropriate intervals in the circumferential direction, for example, six pieces are provided. The recess 12 is located at the edge of the contact surface 11,
As shown in FIGS. 3A and 3B, the flat portion 101
In the vicinity of the side of the corner portion 102 of the cap nut 2 in the screwing direction, a substantially triangular shape is formed when viewed from the side.

The cap nut 2 has a cylindrical portion 14 on the inner circumference at one end.
A female screw portion 20 for screwing into the male screw portion 15, and a taper portion 21 formed on the inner peripheral surface with a reduced diameter toward the other end,
And an opening at the opposite end of the female screw portion 20. This opening is a part for guiding the connecting pipe 5, and the connecting pipe 5
Has an inner diameter slightly larger than the outer diameter of.

The cap nut 2 is mounted on the pipe joint body 1 by screwing the female screw portion 20 into the male screw portion 15 of the pipe joint body 1. When connecting the connecting pipe 5, the cap nut 2 is attached. Loosen or once removed, insert the end of the connection pipe 5 into the opening, and then tighten or screw the cap nut 2. As the screwing of the cap nut 2 progresses, the taper portion 21
Indicates that the tip end portion of the cylindrical portion 14 of the pipe joint body 1 having the cutout portion 16 is pressed in the inner diameter direction to reduce the diameter.

On the contact surface 22 having the female thread portion 20 of the cap nut 2, there is formed a projection 23 for fitting into the recess 12 of the flange 10. When the contact surface 11 of the flange 10 is brought into contact with the contact surface 22 of the cap nut 2, the protrusions 23 are arranged at positions corresponding to the recesses 12, that is, six protrusions are provided. ing. The projection 23 is formed in a substantially trapezoidal shape when viewed from the side surface, but the side surface 231 in the screwing side direction and the opposite side surface 232 are fitted into the recess 12 by entering the recess 12. There is.

Therefore, when the projection 23 is fitted in the recess 12, when the cap nut 2 is turned in the tightening direction, the side surface 231 in the screwing side direction comes into contact with the side surface of the recess 12 and is loosened in the opposite direction. When the nut 2 is turned, the side surface 232 on the side opposite to the screwing direction comes into contact with the side surface of the recess 12 and a large resistance force is generated in any case.

The connecting cylindrical body 3 is provided with a nut 32 having a square shape, for example, a hexagonal shape, in a substantially central portion thereof, a connecting portion 30 for connecting the pipe 4 is provided at one end thereof, and a connecting portion 30 is provided at the other end thereof. A cylindrical guide tube 31 for connecting the pipe 5 is extended. A male screw is formed on the outer peripheral surface of the connecting portion 30, and the connecting pipe 4 is connected by screwing.

The connecting cylinder 3 is mounted on the pipe joint body 1 by fitting the nut portion 32 into the collar portion 10 of the pipe joint body 1. The cylindrical portion 14 of the pipe joint body 1 is arranged concentrically around the guide cylinder 31 of the connecting cylinder body 3, and the connecting pipe 5 is provided between the outer peripheral surface of the guide cylinder 31 and the inner peripheral surface of the cylindrical portion 14. Thus, the gap portion 7 into which is inserted can be formed. Further, an annular groove 33 is provided on the outer periphery of the guide tube 31 on the tip side, and the packing 6 is mounted in the groove 33.

The pipe joint body 1, the cap nut 2 and the connecting cylinder 3 are made of a synthetic resin or a corrosion-resistant material such as aluminum or copper, which may be the same material or different materials.

Next, a case of connecting the connecting pipes 4 and 5 such as a hot water supply pipe and a water supply pipe using the above pipe joint will be described with reference to FIG.

First, the connecting cylinder 3 is attached to the end of one connecting pipe 4.
Screwing the connection portion 30 of the connection nut, and fitting the cap nut 2 removed from the male screw 15 to the other connection pipe 5 in advance, and in the gap portion 7 between the guide cylinder 31 and the cylinder portion 14, the connection pipe 5 Insert. Subsequently, the pipe joint body 1 is fixed with a tool or the like, and the cap nut 2 is turned with a tool or the like to female thread portion 20 of the cap nut 2.
Is screwed onto the male screw 15 of the cylindrical portion 14.

By this screwing, the cap nut 2 becomes the pipe joint body 1
Of the cap nut 2 and tightens the cap nut 2 until the contact surface 22 formed at the tip of the cap nut 2 substantially contacts the contact surface 11 formed on the side surface of the flange 10 of the pipe joint body 1. And the protrusion 23 formed on the contact surface 22 of the cap nut 2,
The pipe joint body 1 is fitted into the recess 12 formed in the contact surface 11 of the flange 10.

When the projection 23 is fitted in the recess 12, the projection 2
When the side surface 23a of the screw 3 in the direction of the screwing side comes into contact with the side surface of the recess 12, a strong tightening resistance required to rotate the cap nut 2 further acts on the tool as a reaction force, and the tightening force is suddenly increased. To increase. Since this tightening force is detected by hand through the tool, this time is judged as the correct tightening position and the tightening is stopped.

At this time, the tapered surface 21 of the cap nut 2 presses the tip of the cylindrical portion 14 where the notch 16 is formed inward. This pressing reduces the diameter of the tip of the cylindrical portion 14 and presses the end of the pipe 5 inward, so that the inner surface of the connecting pipe 5 has the groove 3 of the guide pipe 31 of the connecting pipe 3.
It is pressed against the outer surface of the packing 6 mounted on the sheet 3, and is sealed in a liquid-tight manner at this portion, and the connecting pipe 5 is prevented from coming off. In this way, the connection of the connecting pipes 4 and 5 is completed.

After a long time has passed after connection, when the restoring force of the reduced diameter tip portion of the cylindrical portion 14 disappears, the cylindrical portion 14
Even if the tip portion of the projection 23 weakens the pressing force that pushes the taper portion 21 of the cap nut 2 outward and the cap nut 2 tries to loosen due to vibration or the like, the side surface 23b of the protrusion 23 opposite to the screwing direction is A large resistance force is generated by coming into contact with the side surface of the concave portion 12, its rotation is blocked, and the cap nut 2 is prevented from loosening.

FIG. 4 shows a socket type pipe joint according to another embodiment, which is provided at both ends with a connecting mechanism which is a feature of the present invention. The pipe joint body 1a has a flange portion 10a at its center portion and cylindrical portions 14a extending at both ends thereof, and includes two cap nuts 2a. The pipe joint body 1a, the recess 12a such as the cap nut 2a, the protrusion 23a and other configurations and usage modes are the same as those of the pipe joint shown in FIGS.
The description is omitted because it is essentially the same. Similarly, the structure of the present invention is also applied to an elbow type or cheese type pipe joint.

The shape of the protrusion and the recess may not be the shape shown in FIG. 3, and the protrusion has at least a side surface on the screw side toward the recess and a side surface opposite to the side surface.
Any shape may be used as long as both side surfaces are locked to the side walls of the recess.

For example, as shown in FIG. 5, a cap nut 2b
The projection 23b provided on the base is a rectangular parallelepiped and has a collar 10b.
The recess 12b can be shaped so that the rectangular parallelepiped projection 23b is just fitted. Further, as shown in FIG. 6, the screwing side of the projection 23c provided on the cap nut 2c is chamfered to form an inclined surface, and the recessed portion 12c of the collar portion 10c at the time of screwing.
It may be one that is easily fitted to.

FIG. 7 shows a socket type pipe joint using a connection tube 3d of a mode different from the connection tube 3 of FIGS.

Similar to the pipe joint body 1a in FIG. 4, the pipe joint body 1d has a central portion with a collar portion 10d and cylindrical portions 14d extending at both ends thereof. Cap nut 2d is also 2
One piece is provided and screwed into the cylindrical portion 14d of the pipe joint body 1d.
The connecting tube 3d is used by being attached to the ends of the connecting pipes 4d and 5d without being incorporated in the pipe joint body 1d. The packing 6d used for the water blocking structure between the connecting pipes 4 and 6 and the pipe joint is mounted so as to be sandwiched between the tip end surface of the cylindrical portion 14d and the taper portion 21d of the cap nut 2d.

Therefore, in this pipe joint, the taper portion 21d is packed 6d by screwing the cap nut 2d.
, And as a result the packing 6d causes the connecting pipes 4d, 5
The water blocking function is exerted by being pressed against the outer surface of d. Recess 12
The configurations of d and the protrusion 23d and other configurations are not particularly different from those of the pipe joints of FIGS.

[0048]

As described above, the pipe joint of the present invention is
By fitting the protrusion and the recess, the tightening limit of the cap nut can be sensed, and by stopping the tightening of the cap nut, the cap nut and the threaded portion of the pipe joint body will not be damaged or deformed. Not only can it be sealed, but also the tightening force can be made uniform.

Further, after the connection, the cap nut is prevented from rotating in the reverse direction due to the fitting of the projection and the recess even after vibration, so that the cap nut does not become loose and a good sealing property is provided for a long period of time. Can be maintained.

[Brief description of drawings]

FIG. 1 is a front view of an embodiment of a pipe joint of the present invention.

FIG. 2 is a partially cutaway front view showing a usage state of the pipe joint of FIG.

FIG. 3 is a cross-sectional view of the pipe joint, (a) of FIG.
FIG. 3B is a sectional view taken along the line III, and FIG.

FIG. 4 is a front view of another embodiment.

FIG. 5 is a perspective view showing another aspect of the projection and the recess of the pipe joint of the present invention.

FIG. 6 is a perspective view showing still another aspect of the projection and the recess of the pipe joint of the present invention.

FIG. 7 is a cutaway front view of the upper half of yet another embodiment.

FIG. 8A is a cross-sectional view of a main part of a conventional pipe joint,
(B) is a partial expanded sectional view of (a).

[Explanation of symbols]

 1, 1a, 1d Pipe joint body, 10, 10a, 10b, 10c, 10d Collar portion 12, 12a, 12b, 12c, 12d Recessed portion 14, 14d Cylindrical portion 2, 2a, 2b, 2c, 2d Cap nut 20 Female screw portion 21 , 21d Tapered part 23, 23a Projection part 3, 3d Connection cylinder 4, 4d, 5, 5d Connection pipe 6, 6d Packing

Claims (1)

[Claims] 1. A pipe joint main body having a cylindrical portion externally fitted to an end portion of a connecting pipe and having a male screw portion formed on the outer periphery thereof, and a flange portion protruding from one end portion of the cylindrical portion toward the outer peripheral direction. And a cap nut having a female screw portion that is screwed into the male screw portion of the pipe joint body is formed on the inner circumference of the end portion, and a taper portion is provided on the inner circumference of the base portion. The contact surface formed at the tip of the cap nut is brought close to the contact surface formed at the flange portion of the pipe joint body by screwing between the male screw portion of the pipe joint body and the male screw portion of the pipe joint body, and the taper portion of the cap nut is formed. In the pipe joint in which the outer surface of the connecting pipe fitted in the cylindrical portion of the pipe joint body is pinched by the inward pressing, the contact surface of the cap nut or the contact surface of the flange portion A recess is formed in one of them, and a protrusion that fits in the recess is formed in the other. Pipe joint, characterized by being made.