JPS6220994A - Pipe joint - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pipe joint for a bellows pipe having a corrugated outer surface.

[Conventional technology]

Conventionally, methods for connecting this type of pipe include machining the pipe end into a smooth cylindrical shape and fixing it to a pipe joint by brazing;
Alternatively, a method has been adopted in which the tube end is machined into a funnel-shaped 7-reare shape and is pressed into contact with the end of a tube joint which is protruded in a V-shape.

[Problem that the invention seeks to solve]

However, all of these require processing in the factory, so
A pipe is used that is cut in advance to a certain size and has pipe fittings fixed to both ends.

On the other hand, the current situation is that the piping site is not always fixed, so effective piping cannot be achieved using only short full-date pipes.

For this reason, by applying pressure to the outer circumference of the tube with the rubber gasket,
Another method is to cut long pipes on-site and install them, but there are concerns about the long lifespan and heat resistance of rubber gaskets. Another problem is that after the pipes are connected, water droplets such as rainwater enter the joint from the outside of the joint and come into contact with the pipe inside the joint, gradually corroding the pipe.

In view of the above points, this invention enables easy piping by cutting long pipes on-site in response to on-site conditions, and eliminates the 70- problem caused by rubber aging and thermal expansion, resulting in stable piping over a long period of time. The purpose of this invention is to provide a pipe joint that has excellent leak-proof performance, fire resistance, and external corrosion resistance.

[Means for Solving the Problems] The present invention has a threaded portion on the outer periphery of the end, a tapered hole portion that narrows toward the inner circumference of the end toward the back, and a hole formed at the back of the tapered hole. The pipe holder connected to the through hole includes a joint main body having a wall portion, and a corrugated inner circumferential surface whose inner surface, which is pressed from the rear when the cap nut is tightened, engages with the corrugated outer circumference of the pipe to be connected.1.
a sleeve formed with an outer circumferential surface having an angle smaller than the taper angle of the tapered hole, and provided with a notch so as to divide the outer circumferential surface in the ring direction, leaving a part of the wall thickness on the large diameter side; and the male thread section. It consists of a flange that is screwed into the flange to press the sleeve to the inner part of the joint body, a bag collar F that has a groove on its outer outer surface, and a seal that engages with the groove and seals between the outer surface of the pipe and the flange. It is a pipe joint.

Examples will be described below with reference to the drawings.

〔Example〕

FIG. 1 shows the state before the cap nut is tightened according to the embodiment of the present invention, and FIG. 2 shows the state after the cap nut is tightened.

The joint body 1 has a pipe thread 5 provided on the outer periphery of one end to serve as a connection means to equipment, and has a through hole 6 provided on the inner periphery. The outer periphery of the other end has a parallel male thread 9, and the inner periphery thereof is formed with a tapered hole 7 having an extremely small angle that decreases toward the back of the joint body. The tube holder connected to 6 is provided with a wall portion 8.

The tube 4 is a bellows tube made of thin metal and has a corrugated outer circumferential surface, and a waveform matching the corrugated outer circumference of the bellows tube 4 is formed on the inner circumferential surface of the sleeve 3 to engage with the outer circumference of the bellows tube 4. do. The rear part of the outer peripheral side of the sleeve 3 is designed so that the cap nut 2 can be easily pressed and engaged by tightening, and the tightening margin of the cap nut can be regulated to a constant level by abutting against the open end 71 of the tapered hole 7 of the joint body 1. Although the flange portion 11 protruding toward the outer periphery is provided, it is not an essential condition for completing the MII of the present invention.

The outer circumferential surface in front of the flange g1i is provided with an outer circumferential surface 31 having a small angle of QO~10 degrees from the taper hole 7 of the joint body 1, and in the embodiment, the taper hole 7 of the joint body 1 has an angle of about 2 degrees on one side. The outer peripheral surface 31 of the sleeve 3 has a parallel cylindrical shape with an angle of 0 degrees.

Note that 12 was read by tightening the cap nut 2 when removing the nut 2 from the joint body 1 again and removing the pipe 4 from the wall.
It is a stepped part 12 for hooking a screwdriver etc. so that the sleeve 3 can be easily removed from the joint body 1, and has nothing to do with sealing performance.
As shown in FIG. 3, notches 16 are provided to divide the flange 11 in the ring direction, leaving a portion of the flange 11 intact.

At the rear of the cap nut 2, a concave groove 21 is provided on the outer surface of the nut 2, into which a seal 22 is engaged. I/I? 144 to prevent water droplets from entering from outside the joint.

The fireproof socket 14 is still attached to the wall 111s8 of the tube holder, but this is because the corrugated pipe 4 has a spiral shape, so the tube end 41 and the tube holder have good adhesion to the wall 8. However, in the case of a continuous single-pitch bellows pipe 4 in which the corrugations of the pipe 4 are formed individually, one by one, the pipe ya41 and the pipe holder must be in close contact with the wall 8 at the pipe end. 41, so it is not necessarily necessary.

To connect the pipes, first insert the cap nut 2 into W4, and then attach the notch 16 of the sleeve 3 so that the wave peaks of the IW4 pipe 4 protrude by about 1 to 5 peaks and match the wave peaks of ff4.

In this case, if the material of the sleeve 3 is a soft metal such as copper or copper alloy, even if the notch 16 is made by hand, the remaining portion 15 of the flange portion 11 with the notch left will not be divided, and the tube 4 The sleeve 3 attached to the sleeve 3 is inserted into the tapered hole 7 as shown in FIG. 1, and the cap nut 2 is screwed into the parallel male threaded portion 9 of the joint body 1. When the cap nut 2 is tightened to the first joint body 11 from this state, the sleeve 3 is held at a reduced diameter by the tapered hole 7 and advances toward the back of the tapered hole 7 without crimping the pipe 4. .

Furthermore, the front protruding pipe section 42 to which the sleeve 3 is attached advances at the same time as the sleeve, and the tip ya41 of the protruding pipe s42 hits the wall part 8 of the joint body 1, and as the cap nut 2 is tightened, the protruding pipe section 42 moves forward simultaneously with the sleeve. begins to be compressed, and eventually the tube holder is compressed 9II between the wall portion 8 and the front end portion 32 of the sleeve 2, and a crimp tube portion 43 is formed as shown in Fig. ff12.

A sealing action is performed between the crimp tube portion 43 and the tube holder with the wall portion 8.

In addition, in the figure, a fire-resistant gasket 14 is inserted during this time.
Although it is necessary to further improve the sealing performance by interposing the pipe holder of the fitting body 1! ! ! The sealing effect can also be maintained by the metal-to-metal contact between the crimped tube portion 88 and the crimp tube portion 43.

〔Effect of the invention〕

As described above, according to the present invention, the pipe can be cut on-site and connected to the tube, and since the sleeve is made of metal, there is no need to worry about long-term leak-proofing performance, which is the case when using rubber gaskets. It is possible to solve this problem and create a pipe joint with a long life.

Furthermore, since there is no intrusion of rainwater or the like from outside the joint after connection, there is no problem of corrosion of the pipe within the joint, and durability is improved even when used exclusively for buried piping, for example.

In addition, the bellows pipe 4 is firmly attached to the joint body 1 by the sleeve 3.
Because it is fixed to the wall 8, even if vibration, bending, torsion, or other movement or deformation stress is applied to W4, the tube holder, which is the sealing part, will remain in the wall 8.
No stress is transmitted to the crimped portion of the tube end 41 that is in close contact with the tube end 41, so that the sealing performance is not destroyed by external stress and the sealing performance is strongly maintained.

Furthermore, by making the outer peripheral surface forming the cylinder of the sleeve 3 that fits into the tapered hole 7 of the main body smaller than the angle of the tapered hole 7 of the main body, the sleeve 3 is tightened at the back side of the tapered portion 7 at the initial stage. Since it is locally reduced in diameter and fixed to the tube 4, it is possible to prevent the tube 4 and the cap nut 2 from rotating together due to the tightening of the cap nut 2, thereby preventing the tube 4 from being twisted.

In addition, by providing the flange portion 11 at the rear end of the outer peripheral side of the sleeve 3, the tightening by the bag napht 2 is limited.
The amount of pushing and the amount of diameter reduction of the sleeve 3 can be set within the optimum range.

In addition, as shown in FIG. 3, the sleeve 3 is cut in the axial direction and divided into parts, which are continuous at the remaining part 15 of the flange part 11. When assembling, the sleeve 3 is expanded around the remaining part 15, and The sleeve 3 can be closed by winding it around the tube 4, and the sleeve 3 can be easily attached to the pipe 4, and since the sleeve segments do not separate, the compression by the cap nut 2 is always averaged without causing discrepancies between the sleeve segments. It is done. Furthermore, handling and management of the sleeve 3 is easy.

Moreover, the adhesion between the tube tip 41 and the tube receiving wall 8 can be improved even if the wall 8 of the tube holder at the back of the main body taper hole 7 is coated with a soft elastic material such as plastic instead of the gasket. It is also possible to do so.

By providing a small-diameter stepped portion 12 on the front side of the t-1 flange portion 11 and making it abut against the outer jt1 portion of the main body taper hole portion 7, #? When it becomes necessary to disassemble the sleeve 3 after the connection, the sleeve 3 can be easily pulled out from the tapered part 7 by inserting a tool such as a screwdriver into the gap between the flange part 11 and the opening end 71 and prying it. be.

[Brief explanation of drawings]

Fig. 1 is a partial cross-sectional front view of one example of this invention before the W connection is completed, Fig. 2 is a partial cross-sectional view showing the state after connection, and Fig. 3 is! Fig. 's1 is a side view of the sleeve of Fig. s1; 1: Joint body, 2: Cap nut, 3 Nice sleeve,
4: Snake, llI pipe, 6: Through hole, 7: Taper hole, 8: V receiving wall, 11: Flange,
1t: Gasket, 16: Notch, 21:
Concave groove, 22: Packing, 44: W outer surface coating layer

Claims (4)

[Claims] (1) A threaded portion on the outer periphery of the end, a tapered hole that narrows toward the back on the inner periphery of the end, and a pipe receiving wall that connects with a through hole formed at the back of the tapered hole. and a corrugated inner circumferential surface whose inner surface, which is pressed from the rear toward the joint body by tightening the cap nut, engages with the corrugated outer circumference of the pipe to be connected. A sleeve is formed with an outer circumferential surface having an angle smaller than the taper angle, and is provided with a notch so as to divide the outer circumferential surface in the axial direction, leaving a part of the wall thickness on the large diameter side, and is screwed into the male threaded portion. A tube comprising a collar that presses the sleeve into the inner part of the joint body, a cap nut having a concave groove on its outer surface, and a packing that engages with the concave groove to seal between the tube and the outer surface of the tube. Fittings. (2) In claim 1, the outer circumferential surface of the sleeve has a taper angle of 0 to 1 from the taper angle of the tapered hole.
A pipe joint consisting of an outer peripheral surface with a small angle of 0 degrees. (3) The pipe joint according to claim 1 or 2, wherein a flange portion that expands outward is provided at a rear portion of the outer circumferential surface of the sleeve. (4) A pipe joint according to claim 1, wherein a gasket is attached to the pipe receiving wall.