JPH0511430Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a pipe joint for connecting a corrugated pipe made of a thin metal material and having an axially corrugated outer surface to piping, and in particular, the invention relates to a pipe joint for connecting a corrugated pipe made of a thin metal material with an axially corrugated outer surface. The present invention relates to a pipe joint equipped with a pipe joint.

[Prior Art] As a pipe joint for connecting a corrugated pipe to a pipe, for example, there is a pipe joint shown in FIG. 4, which was filed by the present applicant and disclosed in Japanese Patent Application Laid-open No. 73193/1983. The general structure of this pipe joint includes a sleeve 3 that engages with the outer surface of a corrugated pipe 4, a cap nut 2 that has a collar 22 on the inside of the rear end and a female thread 23 on the front, and a cap nut 2 that has a thread on the front. 19 and a hole 17, a communicating hole 16 with a smaller diameter than the hole 17 is provided at the rear part, and a tube receiving wall 18 is formed. Pressing the protruding part 42 of the protruding corrugated pipe 4 against the pipe receiving wall part 18,
It connects the corrugated pipe 4 to the joint body 1.

In addition, as a pipe joint with electrical insulation performance for steel pipes, there is a pipe joint as shown in FIG.
There is a pipe joint disclosed in No. 60-208687. As shown in Fig. 5, these pipe fittings have a fitting body 1.
This is a pipe joint in which an insulating material 13 made of an insulating coating or an electrically insulating material is interposed on the surface of a connecting screw 12 provided on at least one side of the pipe.

[Problems to be solved by the invention] However, in the above-mentioned conventional pipe joint, the fourth
What was disclosed in Japanese Patent Application Laid-open No. 60-73193, shown in the figure, is
The corrugated pipe 4 can be easily connected at the piping site, but the joint body 1 and the thin-walled metal corrugated pipe 4
There is a state of electrical continuity between the corrugated pipe and the pipe connected to the other end of the joint body 1, and there is a risk that a minute current generated in the pipe connected to the other end of the joint body 1 may cause holes in the surface of the corrugated pipe due to macrocell corrosion. For this reason, it was necessary to provide an extra insulated pipe joint, such as the one disclosed in Japanese Patent Application Laid-open No. 60-37488, on a part of the piping to interrupt electrical continuity, complicating work at the piping site.

In addition, the pipe joint for steel pipes disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 60-37488 and the pipe joint for steel pipes disclosed in Japanese Patent Application Laid-Open No. 60-208687, shown in Fig. 5, require thread cutting on the steel pipes to be connected. When connecting pipe fittings, it is necessary to secure the steel pipe with a wrench, etc. However, it is impossible to cut threads or use a wrench with thin-walled metal corrugated pipes, so conventional technology cannot be used. Furthermore, in the above-mentioned conventional pipe fittings for steel pipes, since an insulating material is interposed in the threaded part, the thickness of the insulating material must be extremely thin, and it must also withstand the shearing force during the threaded joint. , the material was subject to certain limitations.

Therefore, in order to solve the above-mentioned problems of the conventional method, the present invention eliminates the need to perform any processing on the cut corrugated pipe at the piping site, and allows the insulating material to be selected from a wide variety of materials. The present invention provides a pipe joint for connecting corrugated pipes that has excellent electrical insulation performance.

[Means for Solving the Problems] The gist of the present invention is to provide a sleeve that has a corrugated inner surface that engages with the outer surface of the corrugated pipe and has at least one cut in the axial direction so that the corrugated pipe can be attached to the sleeve. , a cap nut with a collar on the inside of the rear end having an inner surface that engages with the rear side wall of the sleeve and a female thread on the front part, an external thread that is screwed into the female thread of the cap nut, and the front of the sleeve. and a joint body having a hole in the front part for inserting the part and a communicating hole with a smaller diameter than the hole in the rear part to form a pipe receiving wall part,
A pipe joint for connecting a corrugated pipe in which a corrugated pipe protruding from the front side of the sleeve is connected by crimping between the front end surface of the sleeve and a pipe receiving wall of the joint body, wherein the pipe receiving wall of the joint body A corrugate characterized in that a ring-shaped packing having both electrical insulation performance and sealing performance is attached to the corrugate, and an electrical insulation member is attached to the inner surface of the hole of the joint body and the inner surface of the collar of the cap nut. This is an insulated pipe joint for pipe connections.

[Function] Since the present invention has the above-mentioned configuration, a cap nut is inserted into the corrugated pipe, the tip of the corrugated pipe is made to protrude, a sleeve is attached to the corrugated pipe, and the hole in the joint body to which the electrically insulating joint member is attached is inserted. When the sleeve is inserted into the sleeve, and then the female thread of the cap nut is screwed into the male thread of the joint body, and the cap nut is tightened and rotated, the sleeve engages with the inner surface of the collar of the cap nut with the electrical insulation member attached. moves toward the joint body, and at the same time, the corrugated pipe engaged with the corrugated inner surface of the sleeve also moves toward the joint body, and the protruding part of the corrugated pipe has both electrical insulation performance and sealing performance with the front end surface of the sleeve. The corrugated pipe is crimped with the pipe receiving wall fitted with the packing, and in this way the corrugated pipe has sealing performance and is electrically insulated and connected to the joint body, and therefore connects to the pipe connected to the rear of the joint body. electrically isolated between the two.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings. Figure 1 shows the state before tightening the cap nut.
FIG. 2 shows the state of the pipe joint shown in FIG. 1 after the cap nut has been tightened.

In Fig. 1, 1 is the joint body, which has a male thread 19 at the front and a tapered hole 17 whose diameter decreases toward the back.
A tapered male thread 15 for connecting to a pipe (not shown), a hexagonal part 14, and a communication hole 16 communicating with the pipe are provided at the rear part, and the diameter of the communication hole 16 is as described above. The diameter is smaller than that of the hole 17, and an annular tube receiving wall portion 18 is formed between the two.

Reference numeral 2 designates a cap nut, which has a female thread 23 on the front part that is screwed into the external thread 19 of the joint body 1, and a collar 22 with an inner surface 21 on the inside of the rear end. The outer surface is formed into a hexagonal shape.

3 is a sleeve having a corrugated inner surface 32 that engages with the corrugated outer surface of the corrugated pipe 4. The rear part of the outer circumference of the sleeve 3 is secured to the cap nut 2 by tightening the cap nut 2.
A flange 31 protruding toward the outer periphery is provided to facilitate press engagement with the inner surface 21 of the rear side wall 39 that engages with the inner surface 21. Flange 31
The outer surface 33 located further forward is formed so as to be fit into the hole 17 of the joint body 1, and is formed into a tapered surface having the same taper angle as the taper of the hole 17 or at a slightly smaller angle. Further, as shown in FIG. 3, the sleeve 3 is provided with an axial cut 35 and a cut groove 34 on opposite ends of the circumference, and when attached to the outer surface of the corrugated pipe 4, the cut groove 34 is opened and the sleeve 3 is divided into two parts. and is installed. 2 from the beginning
A sleeve that is divided may also be used.

Reference numeral 5 denotes a ring-shaped packing having both electrical insulation performance and sealing performance, which is attached to the pipe receiving wall 18 of the joint body, and the tip 41 of the corrugated pipe 4 comes into contact with the pipe receiving wall 18 via this packing 5.

Reference numeral 6 denotes an electrically insulating member attached to the inner surface of the hole 17 of the joint body 1, which is made of a 0.2 to 0.3 mm thick sheet made of glass cloth as a base material and epoxy resin laminated on the upper and lower surfaces thereof.

Reference numeral 7 denotes an electrically insulating member attached to the inner surface 21 of the cap nut 2, and is made of a sheet of the same material as described above.

In addition, in this embodiment, the female thread 2 of the cap nut 2 is
An insulating member 8 made of the same sheet as described above is also installed on the inner inner surface 24 of the inner part except for parts 3 and the front end side surface 11 of the joint body 1.
and 9 are installed, so that even if the chips generated by the screwing of the cap nut 2 and the joint body 1 are interposed near the flange 31 of the sleeve 3, there will be no electrical conduction due to the chips. be.

When connecting the corrugated pipe 4, first attach the packing 5 and the electrically insulating members 6, 9 to the joint body 1, then attach the electrically insulating members 7, 8 to the cap nut 2, and then attach the cap nut 2 to the corrugated pipe 4. is inserted, and the sleeve 3 is attached to the outer surface of the corrugated pipe 4 so that about 2 to 4 peaks at the tip of the corrugated pipe 4 protrude. The sleeve attached to the corrugated pipe 4 is
As shown in the figure, it is inserted into the hole 17 of the joint body 1, and the female thread 23 of the cap nut 2 is screwed together with the male thread 19 of the joint body 1. As the cap nut 2 is screwed in, the sleeve 3 is pressed through the electrically insulating member 7 and the hole 17 is pressed.
It enters the inner part of the corrugated pipe 4 via the electrically insulating member 6, and is compressed by engagement with the tapered part of the hole 17 and crimped onto the corrugated pipe 4.

Further, the protruding part 42 of the corrugated pipe 4 protruding forward from the sleeve 3 also advances at the same time as the sleeve 3, and the tip 41 of the protruding part 42 hits the pipe receiving wall part 18 via the packing 5, and finally the pipe receiving wall part 18 and the sleeve 3 to form a crimp tube portion 43 as shown in FIG. A sealing action is performed between the crimp tube portion 43 and the tube receiving wall portion 18 by the packing 5. Further, the corrugated pipe 4 is connected to the cap nut 2 by the packing 5 and the electrically insulating members 6 and 7.
and is electrically insulated from the joint body 1.

FIG. 6 shows another embodiment of the sleeve 3 and the electrically insulating member 7, in which the sleeve 3 engages with the cap nut 2.
By moving the rear side wall 39 of the sleeve 3 forward of the rear end surface 37 of the sleeve 3, the insulation performance between the rear part 44 of the corrugated pipe 4 and the collar 22 of the cap nut 2 is improved, and at the same time, the inner surface of the collar 22 of the cap nut 2 is Also electrical insulation member 7
is attached to maintain insulation between the collar 22 and the sleeve 3.

[Effects of the invention] As explained above, the pipe joint of the invention can be easily connected to a corrugated pipe in a cut state, and has electrical insulation performance, so there is no problem of corrosion due to electrical conduction such as macrocell corrosion. There is no need to install an extra insulating joint on a part of the piping.

[Brief explanation of the drawing]

Fig. 1 is a partially sectional front view showing a state in which corrugated pipes are connected by a pipe joint according to an embodiment of the present invention, and Fig. 2 shows a state after corrugated pipes are connected by the pipe joint of Fig. 1. 3 is a side view of the sleeve, FIGS. 4 and 5 are front views of a conventional example, and FIG. 6 is a front view of a sleeve and an electrically insulating member. It is a sectional view showing an example. 1... Joint body, 2... Cap nut, 3... Sleeve, 4... Corrugated pipe, 5... Packing, 1
DESCRIPTION OF SYMBOLS 1... Front end side surface, 6, 7, 8, 9... Electrical insulating member, 16... Communication hole, 17... Hole, 18... Tube receiving wall, 21... Inner surface, 24... Inner surface, 31 …
...flange, 32...corrugated inner surface.

Claims (1)

[Claims for Utility Model Registration] 1. A sleeve that has a corrugated inner surface that engages with the outer surface of a corrugated pipe and has at least one slit in the axial direction so that it can be attached to the corrugated pipe, and a rear side wall of the sleeve. A cap nut having a collar having an engaging inner surface on the inside of the rear end and having a female thread in the front part, a male thread to be screwed into the female thread of the cap nut, and a hole into which the front part of the sleeve is inserted. It consists of a joint body that is provided in the front part and has a communication hole smaller in diameter than the hole in the rear part to form a pipe receiving wall part,
A pipe joint for connecting a corrugated pipe in which a corrugated pipe protruding from the front end of the sleeve is connected by crimping between the front end surface of the sleeve and a pipe receiving wall of the joint main body, the pipe receiving wall of the joint main body A corrugate characterized in that a ring-shaped packing having both electrical insulation performance and sealing performance is attached to the corrugate, and an electrical insulation member is attached to the inner surface of the hole of the joint body and the inner surface of the collar of the cap nut. Insulated pipe fittings for pipe connections. 2 Utility Model Registration The insulating pipe for corrugate pipe connection as set forth in claim 1, characterized in that an electrically insulating member is further attached to the front end side surface of the joint body and the inner surface on the back side from the female thread of the cap nut. Fittings.