JPH07158782A - Piping and connecting method of piping - Google Patents

Abstract

PURPOSE:To provide a sufficient connecting strength by firmly mutually connecting pipings differed in diameter by use of a cap nut. CONSTITUTION:A piping 1 has a swollen part 2 expansible and contractible in the longitudinal direction of an outward swollen piping which is circumferentially provided near one end part 1A. A cap nut 4 is inserted in the state where this piping 1 is longitudinally pulled to contract the diameter of the swollen part 2. Thereafter, the piping 1 is longitudinally pushed to extend the diameter of the swollen part 2, and the cap nut 4 is engaged with the swollen part 2. Thus, since a major diameter piping 3 is fixed by the screwing of the cap nut 4, and the swollen part 2 of the piping 1 is also engaged with the cap nut 4, the piping 1 and the major diameter piping 3 can be firmly connected to each other to the separating directional force. The cap nut 4 can be easily mounted and engaged by the expansion and contraction of the swollen part 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe and a pipe connecting method, and more particularly, to a pipe having a different diameter when a cap nut is used to connect the pipes and a connecting method using the pipe. Regarding

[0002]

2. Description of the Related Art FIG. 3 shows a conventional method for connecting different diameter pipes. A large-diameter pipe (hereinafter referred to as "large-diameter pipe") 11 having a male screw 11a on the outer peripheral surface on the connecting end side, and a small-diameter pipe (hereinafter referred to as "small-diameter pipe") 12; The cap nut 13 and the annular rubber packing 14 are used. First, the cap nut 13 and the rubber packing 14 are fitted into the small diameter pipe 12, and the end of the small diameter pipe 12 is inserted into the large diameter pipe 11. Next, the cap nut 13 is screwed into the male screw 11a. When the cap nut 13 is strongly screwed in, the rubber packing 1
The large-diameter pipe 11 and the small-diameter pipe 12 are connected and fixed with good watertightness (or airtightness) by the tightening force generated by pressing and deforming 4.

[0003]

According to the above-described conventional pipe connecting method, the large diameter pipe and the small diameter pipe can be connected with good watertightness (or airtightness), but the connection strength is sufficiently high. It can not be said. That is, the connection strength is not sufficient with respect to the force that strongly pulls the large diameter pipe and the small diameter pipe in the separating direction, and the pipe may come off.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems and to provide a pipe capable of easily and firmly connecting different diameter pipes and a connecting method using the pipe.

[0005]

According to a first aspect of the present invention, there is provided a pipe having a bulging portion, which bulges outward and is expandable / contractible in a longitudinal direction of the pipe, in the vicinity of one end. To do.

According to a second aspect of the present invention, there is provided a method for connecting pipes, wherein one end of the pipe of claim 1 is inserted into a cylindrical body having an external thread on the outer periphery of the end, and the rear end edge of the cap nut is set to the bulging portion. Of the pipe which is screwed into the male screw while being locked, and the bulging portion is sandwiched between the rear end edge of the cap nut and the front end surface of the tubular body to connect the pipe to the tubular body. A connecting method, in which the bulging portion is contracted by pulling the pipe in a longitudinal direction prior to inserting the pipe into the tubular body, and in this state, a cap nut is inserted from one end side of the pipe. And passing through the bulging portion, and then pressing the pipe in the longitudinal direction to expand the bulging portion so that the rear end edge of the cap nut can engage with the bulging portion. It is characterized by having done.

[0007]

In the pipe of the present invention, a bulging portion that bulges outward is provided in the vicinity of one end (connecting end). For this reason, one end (connecting end) of the pipe of the present invention is inserted into a tubular body provided with a male screw on the outer periphery of the end, and the rear end edge of the cap nut is locked to the bulging portion of the tubular body. The pipe can be firmly connected to the tubular body by being screwed into the male screw and sandwiching the bulging portion of the pipe between the rear end edge of the cap nut and the tip surface of the tubular body. In this connection structure, since the cap nut is fixed to the tubular body by screwing and the pipe is locked to the cap nut by the bulging portion, the tubular body and the pipe have sufficient force in the separating direction. It shows the connection strength, and the pipe is hardly detached.

Moreover, the bulging portion of the pipe of the present invention can be expanded and contracted in the longitudinal direction of the pipe. Therefore, it is possible to reduce the diameter of the bulging portion by pulling the pipe in the longitudinal direction, and it is possible to easily insert the cap nut from the connecting end side of the pipe in a state where the bulging portion is reduced in diameter. it can. And
After passing the cap nut through the bulging part, the bulging part can be expanded by pressing the pipe in the longitudinal direction. Can be securely engaged.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of the pipe of the present invention, and FIG. 2 is a sectional view showing an embodiment of a connecting structure by the pipe of the present invention.

As shown in FIG. 1, the pipe 1 of the present invention is provided with a bulging portion 2 which bulges outward in the vicinity of the connecting end portion 1A thereof. The bulging portion 2 is expandable / contractible in the longitudinal direction of the pipe 1, and as shown in FIG. 1B, the bulging portion 2 can be contracted by pulling the pipe 1 in the longitudinal direction.
On the contrary, as shown in FIG. 1C, the bulging portion 2 can be expanded in diameter by pressing the pipe 1 in the longitudinal direction. That is, in FIG. 1, the diameters A, B, C of the bulging portion 2 in each state are shown.
Are in the relationship of B <A <C.

Such a pipe of the present invention can be easily manufactured, for example, by forming the bulging portion by blow molding of synthetic resin.

The shape of the bulging portion is not particularly limited as long as it is near the connecting end of the pipe. In addition, the size (bulging width from the pipe), wall thickness, shape, etc. of the bulging portion is not particularly limited, and may be appropriately set according to the size of the cap nut used for connecting the pipes, the size, the shape of the pipe, or the like. It is determined.

In order to connect such a pipe of the present invention to a tubular body such as another pipe, as shown in FIG. 2, a pipe 1 according to the present invention in which a male screw 3a is provided on the outer periphery of the connecting end. For a pipe (large-diameter pipe) 3 having a diameter larger than that of the connecting end 1A of the pipe 1.
, The female nut 4a of the cap nut 4 is screwed into the male screw 3a of the large diameter pipe 3 while the rear end edge 4A of the cap nut 4 is locked to the bulging portion 2 of the pipe 1. Edge 4A
And the tip surface 3A of the large-diameter pipe 3 with the bulging portion 2 of the pipe 1 sandwiched by the rubber packing 5 to form the large-diameter pipe 3
Connect to.

As a result, the pipe 1 is locked to the cap nut 4 at the bulging portion 2, while the large-diameter pipe 3 is fixed to the cap nut 4 by screwing. Therefore, the pipe 1 and the large-diameter pipe 3 are solid. Connected to.

In connection with such a connection, since the bulging portion 2 of the pipe 1 can be expanded and contracted in the longitudinal direction of the pipe 1, the diameter of the bulging portion 2 is reduced by pulling the pipe 1 in the longitudinal direction ( 1 (b) state), in this state the cap nut 4
Can be easily inserted from the side of the connecting end 1A of the pipe 1, and the bulging portion 2 can be passed through. And then
The bulging portion 2 is expanded by pressing the pipe 1 in the longitudinal direction (see FIG.
In the state (c), the rear end edge 4A of the cap nut 4 can be reliably engaged with the bulging portion 2.

In FIG. 2, the bulging portion 2 of the pipe 1
The rubber packing 5 is interposed between the rubber packing 5 and the front end surface 3A of the large-diameter pipe 3, and the bulging portion 2 is interposed between the rubber packing 5 and the rear end edge 4A of the cap nut. Since 2 also plays the role of a washer, the cap nut 4 can be easily tightened.

[0018]

As described above in detail, according to the pipe and the pipe connecting method of the present invention, different diameter pipes can be easily and firmly connected and fixed using a cap nut.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the pipe of the present invention.

FIG. 2 is a cross-sectional view showing an example of a connection structure by piping of the present invention.

FIG. 3 is a diagram showing a conventional method for connecting pipes, (a)
Shows an exploded perspective view, and (b) shows a sectional view.

[Explanation of symbols]

 1 piping 2 bulge 3 large diameter piping 4 cap nut 5 rubber packing

Claims (2)

[Claims] 1. A pipe in which a bulging portion which bulges outward and is expandable and contractible in the longitudinal direction of the pipe is provided in the vicinity of one end. 2. The one end of the pipe according to claim 1 is inserted into a cylindrical body having an external thread on the outer periphery of the end, and the rear end edge of the cap nut is locked to the bulging portion while the external thread is attached to the external thread. A method for connecting pipes, wherein the pipe is connected to the cylinder by screwing, and the bulging portion is sandwiched between the rear end edge of the cap nut and the front end surface of the cylinder. Prior to inserting into the tubular body, the pipe is pulled in the longitudinal direction to reduce the diameter of the bulging portion, and in this state, a cap nut is inserted from one end side of the pipe,
Moreover, the bulging portion is passed, and then the pipe is pressed in the longitudinal direction to expand the bulging portion so that the rear end edge of the cap nut can be engaged with the bulging portion. A method for connecting pipes characterized by the above.