JP2784365B2 - Pipe fittings - Google Patents

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 pipes by tightening cap nuts.

[0002]

2. Description of the Related Art In the above-mentioned pipe joint, a pipe is temporarily tightened with a weak force such as hand tightening at the time of normal construction, and then a main tightening is performed using a tool such as a pipe wrench. At this time, if the pipe connection is completed halfway with only temporary fastening of the pipe joint and the final work with a wrench or the like is not performed, no leak is detected in the leak test after piping. May leak during use. Therefore, it is very important for the contractor to check whether the pipe joint has been completely tightened.

Conventionally, Japanese Unexamined Utility Model Publication No. 63-145089 discloses a disc spring having only one surface colored between a flange and a nut of a joint body, as shown in FIGS. When the nut is screwed into the joint main body to complete the connection with the pipe, the disc spring is sandwiched between the main body and the nut in an upright state as shown in FIG. Confirm completion.

[0004] Further, as disclosed in Japanese Utility Model Laid-Open Publication No. 3-59586, as shown in FIGS. 9 and 10, between the abutting portion provided on the main body and the end of the cap nut, two different diameters are provided. One ring sandwiches an adjustment ring integrally molded in a step-like manner. In the temporarily tightened state of FIG. 9, the nut is locked because the nut is clamped without deforming the adjustment ring, but in the fully tightened state with a wrench, the adjustment ring is broken from its stairs and overlaps as shown in FIG. The outer surface on the side with the smaller diameter becomes invisible, and the completion of the tightening of the cap nut by the final tightening can be confirmed.

[0005]

In any of the above conventional pipe joints, the packing in the joint body may come into contact with the pipe while the cap nut is manually tightened, and the fluid in the pipe may be sealed. In addition, it is necessary to provide a large flange corresponding to the outer diameter of the cap nut, which is considerably larger than the outer diameter of the thread when the external thread of the joint body is used. It is. In addition, when this tightening is performed, the disc spring and the adjusting ring are sandwiched between the abutment portion of the main body and the cap nut, the cap nut is locked, and the cap nut cannot be further tightened. Further, in the latter type, in which the two rings having different diameters sandwich the adjusting ring in which the rings are integrated stepwise, if the outer surface of the ring is to be identified by color, the part to be identified after molding is colored because of the integral structure. There is a need. The present invention solves the above-mentioned problems, can easily confirm the connection failure due to forgetting to tighten the cap nut, and can prevent the construction error. The joint body can be formed compactly, and the end thread is machined. It is an object of the present invention to provide a pipe joint that does not require an obstructive flange, can easily perform thread processing, and can retighten a cap nut after connection is completed.

[0006]

SUMMARY OF THE INVENTION The gist of the present invention is to provide a pipe joint for connecting a pipe by tightening a cap nut screwed into a male screw of a joint body, the center being located near the center in the axial direction following the male screw of the joint body. A locking portion is provided on the outer periphery, an outer ring is mounted between the locking portion and a cap nut screwed into a male screw, and at a position where sealing with a pipe is not performed, the cap nut is manually tightened. When the locking part and the outer ring collide, the rotation of the cap nut is locked and the cap nut is fully tightened using a tool.When the cap nut is tightened, the outer ring slides toward the outer surface of the locking part. A pipe joint characterized by covering an outer surface of a locking portion and making a seal connection with a pipe.

[0007]

According to the present invention having the above-described structure, the cap nut abuts against the end face of the outer ring in the temporarily tightened state by hand,
Since the outer ring abuts a locking portion provided on the joint body, the rotation of the cap nut is locked, and screwing by hand tightening is restricted. Therefore, when the cap nut is manually tightened, the internal fluid leaks from the connection portion of the pipe, so that a defective connection can be easily detected in a leak test after pipe installation. Next, when the cap nut is fully tightened using a tool such as a wrench, the outer ring slides on the outer surface of the engaging portion provided on the joint body, and receives an expanding deformation force on the outer surface of the engaging portion. When raised, the outer ring covers the outer surface of the locking portion, and the outer surface of the locking portion becomes invisible. When this tightening is completed, the seal connection with the pipe is completed,
In addition, it can be easily confirmed whether or not the cap nut has been fully tightened by making the locking portion invisible. Further, since the cap nut does not hit the lock section even when the lock section is not visible, the cap nut can be further tightened. In addition, since a flange that hinders the processing of the external thread of the joint body is unnecessary, the external thread processing is easy. In addition, since the locking portion and the outer ring are separate members, for example, the outer ring can be formed of a material of a different color from that of the locking portion so that identification can be easily performed.

[0008]

1 to 4 show an embodiment of the present invention.
FIG. 1 shows a state of temporary tightening by manual tightening, and FIG. 2 shows a state of final tightening by wrench hooking. The joint body 7 is provided with a taper outer surface 71 which is in contact with the inner surface of the flare portion 81 of the tube 8 connected to the end, and a rubber groove 73 provided with a packing groove 72 provided on the taper outer surface 71. A parallel external thread 74 is formed following the taper outer surface 71.
The female screw 41 of the cap nut 4 is screwed into the nut. An annular groove 75 is provided on the outer surface on the center side following the male screw 74, and the locking ring 5 is attached to the annular groove 75 to form a locking portion.

The locking ring 5 has a slit 52 at one end on the circumference.
And is fitted into the annular groove 75 from the end of the joint body 7 beyond the external thread 74. A tapered surface 51 is provided on the outer surface on the end side, and the outer ring 2 is locked on the tapered surface 51 as shown in FIG. The outer surface of the locking ring 5 is colored red, blue or the like so that it can be easily distinguished from the joint body surface.

The outer ring 2 is made of resin or metal and is provided with a cut in an annular or circumferential part thereof. A locking portion 21 is provided at a portion where the outer ring 2 comes into contact with and locks with the locking ring 5. . The cap nut 4 has a female screw 41 to be screwed into an external thread of the main body and a taper inner surface 42. When the cap nut 4 is tightened to the joint main body 7, the flare portion 81 of the pipe 8 forms a taper outer surface 71 of the main body with the cap nut. Tapered between the taper inner surface 41 and the taper outer surface 7
The rubber ring 73 mounted on the tube 1 comes into contact with the flare portion 81 of the tube and is sealed, whereby the tube 8 is sealed.

In connection, as shown in FIG. 1, when the flared portion 81 of the pipe 8 is engaged with the cap nut 4 and screwed into the joint body by hand-tightening, the outer ring 2 engaged with the engaging ring 5 is engaged. And the rotation of the cap nut is restricted, so that the cap nut 4 cannot be screwed any further. In this state, since the inner surface of the flare portion 81 of the tube does not compress the rubber ring 73, the sealing function with the tube 8 does not work. Next, as shown in FIG. 2, when the cap nut 4 is fully tightened using a pipe wrench or the like, the outer ring 2 is pressed toward the center of the main body by the tightening force of the cap nut. It moves up and slides. When the flare portion 81 of the tube is completely tightened, it covers the outer surface of the locking ring 5 and the outer surface of the locking ring 5 cannot be seen. Therefore, since the colored surface on the outer surface of the locking ring becomes invisible, it can be easily confirmed from the outside that the tightening of the cap nut 4 by the final tightening is completed. In this state, the taper inner surface 42 of the cap nut clamps the flared portion 81 of the tube between the taper outer surface 71 of the main body, and the sealing and retaining action with the tube 8 works. In this state, since the end face of the cap nut 4 does not abut on the locking ring 73,
After the final tightening, the cap nut 4 can be further tightened.

FIG. 4 shows another embodiment in which the locking ring 5 and the outer ring 2 of the above embodiment are integrated. The locking ring 5 and the outer ring 2 are bonded or welded at several places on the circumference. They are not separated before connection. Note that the locking ring 5 may be provided with a locking portion integrally with the joint main body without being separated from the joint main body 7. Further, the connection structure with the pipe 8 is not a flare type as in the above embodiment, but may be another connection structure.

FIG. 5 shows a taper surface in which the locking ring and the outer ring contact each other in two steps, and a step 53 is provided between them. When the cap nut is manually tightened, the outer ring 24 slides while abutting on the tapered surface 55 of the locking ring 54, and abuts on the step 53 to complete the manual tightening. Thereafter, when the final tightening is performed, the outer ring 24 slides while climbing over the step portion 53 and abutting against the taper surface 56, and when the final tightening is completed.
Covers the locking ring 54 so that the outer surface of the locking ring 54 cannot be seen. The outer ring 24 may be provided with a cut groove in a part of the circumference so that the outer ring can be expanded and contracted in an elastic state. In this case, the movement of the locking ring is interlocked with the tightening state of the cap nut, so that the tightening can be confirmed more reliably.

FIG. 6 shows a configuration in which parallel surfaces where the locking ring and the outer ring contact each other are provided in two steps, and a step 57 is provided between them.
When the cap nut is manually tightened, the outer ring 28
Slides while abutting against the parallel surface 59, and abuts against the stepped portion 57 to complete the manual tightening. Thereafter, when the main tightening is performed, the outer ring 28 slides over the stepped portion 57 while abutting on the parallel surface 60. When the main tightening is completed, the outer ring 28 covers the locking ring 58 and the outer surface of the locking ring 58 becomes invisible.

[0015]

As described above, in the pipe joint of the present invention, the separation between the manually tightened state and the fully tightened state of the cap nut can be easily confirmed from the outside and from the viewpoint of an operator.
That is, in the manually tightened state, the tightening rotation of the cap nut is regulated in a state where the internal fluid leaks from the connection portion of the pipe. For this reason, the connection portion leaks unless the main tightening is performed, so that a connection failure portion can be easily detected by a leak test after the piping is installed. Next, in a fully tightened state of the cap nut using a tool such as a wrench, the outer ring covers the outer surface of the locking portion, and the outer surface of the locking portion becomes invisible. When the tightening is completed, the seal connection with the pipe is completed, and it is easy to confirm whether the cap nut has been fully tightened because the locking portion is not visible. This prevents connection mistakes in the connection work,
Also, connection confirmation after construction can be easily performed. Also, the joint body can be formed compactly, and the processing of male threads can be performed easily.
Further, the cap nut can be further tightened after the connection, so that a more reliable connection can be performed.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view illustrating a hand-tight state according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of a fully tightened state showing one embodiment of the present invention.

FIG. 3 is a partial cross-sectional view showing an engagement state between a locking portion and an outer ring.

FIG. 4 is a partial cross-sectional view showing an engagement state between a locking portion and an outer ring according to another embodiment.

FIG. 5 is a partial cross-sectional view showing an engagement state of another locking portion and an outer ring according to the embodiment of the present invention.

FIG. 6 is a partial sectional view showing an engagement state between another locking portion and an outer ring according to the embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a conventional technique in a hand-tight state.

FIG. 8 is a sectional view showing a conventional technique in a final fastening state.

FIG. 9 is a cross-sectional view of another conventional technique in a hand-tight state.

FIG. 10 is a cross-sectional view showing another conventional technique in a final fastening state.

[Explanation of symbols]

 2, 24, 28 Outer ring 4 Cap nut 5, 54, 58 Locking ring 7 Joint body 8 Pipe 41 Female screw of cap nut 42 Taper taper inner surface 51, 55, 56 Tapering surface of locking ring 53, 57 Step portion of locking ring 59, 60 Parallel surface of locking ring 71 Tapered outer surface of joint body 72 Packing groove 73 Rubber ring 74 Male screw 75 Ring groove 81 Flare portion

Claims (1)

(57) [Claims] 1. A pipe joint for connecting a pipe by tightening a cap nut screwed into a male screw of a joint body, wherein a locking portion is provided on an outer periphery near the center in the axial direction following the male screw of the joint body. An outer ring is attached between a stop portion and a cap nut screwed into a male screw, and at a position where sealing with a pipe is not performed, the locking portion and the outer ring collide with each other in a manually tightened state of the cap nut. With the rotation of the cap nut locked, the cap nut is fully tightened with a tool, and the outer ring slides toward the outer surface of the lock by tightening the cap nut, obscuring the outer surface of the lock and the pipe. A pipe joint characterized in that a seal connection is made with the pipe joint.