JPS60252890A - 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 The present invention relates to a pipe joint for a bellows pipe whose outer surface is formed into a corrugated shape.

Conventional methods for connecting this type of pipe include forming the pipe end into a smooth cylindrical shape and fixing it to a pipe joint by brazing, or flaring the pipe end into a funnel shape and protruding into a V-shape. Methods such as pressure contacting the ends of pipe joints have been adopted. However, since all of these require processing in a factory, pipes are used that are cut to a certain size in advance and have pipe fittings fixed to both ends. On the other hand, since the piping site is not necessarily constant, it is currently not possible to construct effective piping using only short corrugated pipes.

For this reason, a method has been adopted in which long pipes are cut on site by crimping a rubber seal to the outer circumference of the pipe, but there are concerns about the long lifespan and heat resistance of the rubber seal. .

In view of the above points, this invention not only enables easy piping by cutting long pipes on-site in response to on-site conditions, but also eliminates flow problems 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 with leak-proof performance and fire resistance.

The gist of the present invention is to provide a joint body having a tapered hole portion that narrows toward the inner peripheral side of the end portion and a wall portion of the pipe holder that is connected to the through hole formed at the back of the tapered hole portion; A cap nut is screwed onto the male thread, and the inner surface, which is pressed from the rear when the cap nut is tightened, has a corrugated inner circumferential surface that engages with the corrugated outer circumference of the pipe to be connected. A pipe joint comprising a sleeve that forms an outer circumferential surface and has a cut groove in the axial direction leaving a part of the wall thickness on the outer circumferential surface and a cut groove on the other side. I will explain about it.

FIG. 1 shows the state before tightening of the cap nut of the embodiment of the present invention, and FIG. 2 shows the state after tightening the cap nut.

The joint body 1 has pipe threads 5 on the outer periphery of its seven ends to serve as means for connecting to equipment, and a through hole 6 on the inner periphery. The other end has a parallel male thread 9 on its outer periphery, and a tapered hole 7 with an extremely small angle that decreases toward the back of the joint body is formed on its inner periphery, and is connected to a through hole on the back side. The tube holder 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. match. The rear portion of the outer peripheral side of the sleeve 3 is designed so that the cap nut 2 can be tightened to easily engage the cap nut 2, and also to abut against the open end 71 of the tapered hole 7 of the joint body 1, so that the tightness of the cap nut can be regulated to a constant level. Although a flange portion 11 extending toward the outer circumferential side is provided, this is not an essential requirement for the configuration of the present invention. The outer peripheral surface in front of the flange portion 11 is the main body 1.
In the embodiment, the outer circumferential surface of the sleeve 3 has a parallel cylindrical shape with a small angle of 0 to 10 degrees from the tapered hole 7, whereas the tapered hole of the joint body has an angle of about 2 degrees on one side. It is formed. In addition, after connecting the cap nut 2 by tightening the nut 2, loosen the nut 2 from the joint body 1 again, and when removing the pipe 4, there is a stepped part 12 for hooking a screwdriver etc. so that the sleeve 3 can be easily removed from the body 1. This has no bearing on sealing performance. As shown in FIG. 3, this sleeve 3 has a V-shaped groove 16 having an angle θ 1 in the axial direction and a cut groove 17 on the other side, leaving a part of the wall thickness on the outer peripheral surface.

This angle θ 1 is the angle between the sleeve 3 and the connected pipe 4 shown in FIG.
This corresponds to the amount of deformation θ 2 during serving.

In addition, a fire-resistant gasket 14 is attached to the wall portion 8 of the tube holder, but this is not possible if the corrugated tube 4 has a spiral waveform.
The pipe end 41 and the pipe holder are necessary to maintain good adhesion with the wall 8 and sealing performance, but in the case of the continuous interior bellows pipe 4 in which the pipe 4 has a corrugated waveform formed individually, Since the end 41 and the tube holder are in close contact with each other along the entire circumference of the tube end, it is not necessarily necessary to provide the gasket 14.

When connecting the pipes, the cap nut 2 is first inserted into the pipe 4, and then the notch 16 of the sleeve 3 is opened so that about 1 to 5 crests of the pipe 4 protrude, and the pipe 4 is attached so as to match the crests of the pipe 4.

In this case, the material of the sleeve 3 is made of a soft metal such as copper or copper alloy, and the sleeve 3 is attached to the pipe 4 by opening the cut portion 17 by hand as shown in FIG.
If the tube is mechanically deformed until the flange portions 162 come into contact with each other, the fitting of the pipe to be contacted is easy, and the remaining portion 15 of the flange portion 11 is not divided.

Insert the sleeve 3 attached to the pipe 4 into the tapered hole 7 as shown in FIG.
be screwed together. From this state, when the cap nut 2 is tightened toward the joint body, the sleeve 3 is maintained at a reduced diameter by the tapered hole 7 and advances toward the back of the tapered hole 7 while compressing the pipe 4. Further, the front tube 42 with the sleeve 3 attached advances at the same time as the sleeve, and the tip 41 of the tube 42 abuts the tube holder of the joint body 1 against the wall 8, and as the cap nut 2 is tightened, the protruding tube portion 42 begins to be compressed. Additionally, the tube holder is crimped between the wall portion 8 and the front end 31 of the sleeve 2 to form a crimped tube portion 43 as shown in FIG. A sealing action is performed between the crimp tube portion 43 and the tube holder and the wall portion 8. In the figure, a fire-resistant gasket 14 is interposed between these parts to further improve the sealing performance, but the joint body tube holder can maintain the sealing effect even if the wall 8 and the crimp tube end 41 are in close contact with each other. .

As described above, according to the present invention, pipes can be easily connected by cutting them on site, and since the sleeve is made of metal, there is no need to worry about long-term leak-proof performance when using rubber gaskets. This makes it possible to realize long-life pipe joints.

In addition, since the bellows tube 4 is firmly fixed to the joint body 1 by the sleeve 3, even if the tube 4 is subjected to movements such as vibration, bending, torsion, or deformation stress, the tube holder, which is a sealing portion, will not move at the wall portion 8.
No stress is transmitted to the crimped portion of the tube end 41 which is in close contact with the pipe. Therefore, 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, thereby preventing the tube 4 from twisting.

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 cap nut 2 is limited.
The pushing amount and the diameter reduction amount of the sleeve 3 can be set within the optimum range.

Further, as shown in FIG. 3, since a V-shaped groove 16 is provided on one side of the outer periphery of the sleeve 3, when assembling, as shown in FIG. 16 angle θ
It can be expanded for one minute and then closed by wrapping it around the outside diameter of the tube 4, making it extremely easy to attach the sleeve 3 to the tube 4, and since the sleeve segments do not separate,
Bag nut 2 without causing any discrepancy between the sleeve pieces.
Pressure is always averaged. Furthermore, handling and management of the sleeve is easy.

Furthermore, it is also possible to improve the adhesion between the tube tip 41 and the wall 8 by coating the wall 8 at the back of a part of the main body taper with a soft elastic material such as plastic instead of the gasket.

Further, a small-diameter stepped portion 12 is provided on the front side of the flange portion 11,
By making the main body taper abut against the outer end of the hole 7, when it becomes necessary to disassemble the sleeve 3 after connection, a tool such as a screwdriver can be inserted into the gap between the collar 5Il111 and the cylindrical part 8 to pry it up. Sleeve 3
can be extracted from the tapered portion 7.

[Brief explanation of the drawing]

FIG. 1 is a side view of 3 in one embodiment of the present invention before the pipe connection is completed. 1: Joint body, 2: Cap nut, 3 Ni sleeve, 4: Bellows pipe, 7: Taber one hole, 8: Tube holder is wall, 11: Flange, 12: Step, 16: V-shaped groove 17: Kirikarimizo Agent Patent Attorney Taka Ishi Tachibana Ma ,, Low, Steam: Sae 7
@Figure 2

Claims (1)

[Claims] 1. A pipe having a d-threaded portion on the outer periphery of the end, a tapered hole portion on the inner periphery side of the end that decreases toward the back, and a pipe connected to a through hole formed at the back of the tapered hole. The receiver includes a joint body having a wall portion, a cap nut that is screwed into the male threaded portion, and an inner surface that is compressed from the rear toward the joint body when the cap nut is tightened and engages with the corrugated outer periphery of the connected pipe. The tapered inner circumferential surface has a corrugated inner circumferential surface, an outer circumferential surface having a smaller taper angle than the taper angle of the tapered hole, and an outer circumferential surface having a wall thickness of 1 of the wall thickness of the corrugated inner circumferential surface.
1. A pipe fitting comprising: a sleeve having a notch dividing the outer circumferential surface of the sleeve in the axial direction with a cut portion remaining, and a sleeve having a cut portion on the other side; 2. In claim 1, the outer circumferential surface of the sleeve is 0 to 10 times smaller than the taper angle of the tapered hole.
A pipe joint consisting of an outer peripheral surface with a small angle. 3. A pipe joint according to claims 1 and 2, wherein a flange portion that expands outward is provided at a rear portion of the sleeve circumferential surface. 4. The pipe joint according to claim 1, wherein a gasket is attached to the pipe receiving wall.