JPH0413427A - Manufacture of flare flange and pipe expansion tool used therefor - Google Patents

Abstract

PURPOSE:To prevent the contraction of a pipe by fitting a cylindrical body into the inside of the pipe in the course of working of a flare flange so that the pipe is not contracted in the root part of the flange, at the time of expanding the pipe end by pressing a cone against the end of the pipe, while rotating it. CONSTITUTION:When hydraulic pressure is applied to the inside of a cylinder 1 from a port 1a, a piston 2 advances, and a piston shaft 3 and a cone 8 advance toward a pipe 13. The cone 8 attached eccentrically so as to be freely rotatable to the tip of a rotary shaft 4 is pressed against the end of the pipe 13, while driving to rotate this rotary shaft, and by expanding the pipe end, a flange 13a is formed. In the course of flare working, a cylindrical body 27 is fitted into the inside of the pipe so that the pipe is not contracted in the root part of the flange. In such a way, it can be prevented that the pipe is contracted in the root part of the flange.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method of expanding the end of a pipe to form a flare flange, and a pipe expanding tool used in the method.

(Prior Art) Conventionally, instead of welding flanges, a method has been developed in which the end of a pipe is expanded using a flare machine to form a flange. According to this method, not only can the welding process be omitted, but also the welding distortion that is inherent in welding flanges can be eliminated.

The method of fabricating a flare flange will be explained with reference to the drawings. In FIG. 1, reference numeral 1 denotes a hydraulic cylinder fixed to a machine base, into which a piston 2 is inserted so as to be able to freely slide back and forth. A piston shaft 3 integral with the piston 2 extends outward through both ends of the cylinder l.

The piston shaft 3 is formed hollow, and a rotary shaft 4 is rotatably supported therein. The symbol δ is a conical roller bearing that supports the rotating shaft, and the symbol 6 is a radial bearing.

The rear end of the rotating shaft 4 is coupled to a drive device so that it can move back and forth.

A crank 7 is fixed to the front end of the rotating shaft 4, and a cone 8 is attached to this.

With this structure, when hydraulic pressure is applied from the boat 1a into the cylinder 1, the piston 2 moves forward, and accordingly, the piston shaft 3 and cone 8 move forward toward the vibrator 13. ing. When hydraulic pressure is applied to the boat 1b, the piston 2 and therefore the cone 8 move back.

The shaft 9 of the cone 8 is eccentric from the rotation axis 4 and is not parallel to the rotation axis, but is attached obliquely.

The cone 8 is detachable from the crank 7, and two types of cones are available. One is a first cone 8a with a tip angle of 37 degrees, and the other is a second cone 8b with a tip angle of 143 degrees.

Reference numeral 12 is a clamp for fixing the vibrator 11.

When processing, first, the first cone 8a is attached to the crank 7, and the cone 8 is advanced while rotating the rotating shaft 4. Then, the vibrator 13 is pressed by the cone 8.
The tube end of the tube is enlarged at an angle of 37 degrees with respect to the pipe axis, as shown at 13a.

Note that when the cone 9 is pressed against the tube end, the cone 8 is mounted on a radial bearing 10 so that the cone rotates around the shaft 9 and the frictional resistance between the cone and the vibrator 13 is reduced.
It is supported by Further, the axial load applied to the cone 8 is borne by the thrust bearing 11.

Next, replace the cone with the second cone 8b and repeat.
When the cone is advanced, the tube end is further enlarged to a right angle, forming a flange 13a (FIG. 8).

(Problem to be Solved by the Invention) By the way, when a flare flange is formed in this way, especially in the case of a thin-walled pipe, the neck of the vibrator (the base of the flange) becomes constricted, as shown by the chain line in Fig. 8. A phenomenon can be seen. Of course, such a constriction is not desirable in terms of strength,
Furthermore, when forming a lined vibe by inserting a liner into the vibrator, a problem arises in that the liner cannot be inserted.

The present invention provides a method for manufacturing a flare flange that does not cause such neck tension, and a device used therefor.

(Means and effects for solving the problem) This invention has a cone eccentrically and rotatably attached to the tip of a rotating shaft.
In the method of manufacturing a flare flange, in which the rotary shaft is rotationally driven and pressed against the end of the vibrator to expand the tube end to form a flange, during the flaring process, in order to prevent the vibrator from becoming constricted at the base of the flange, To provide a method for manufacturing a flare flange characterized by fitting a cylindrical body inside a vibrator.

According to this method, the flaring process is performed with the cylindrical body fitted inside the vibrator, so the vibrator does not become constricted at the base of the flange.

The present invention also provides a device that fits into a vibrator to prevent the vibrator from being crushed during flaring, and the device is a cylinder that is divided into several parts in the axial direction and whose inner diameter increases toward one end. a disk-shaped disk whose outer shape expands toward the outside, placed in the cylinder, and a disk-shaped support disk supported by the cylinder so as not to move in the axial direction; A pipe expanding tool is provided which is made of a bolt that fastens a disk to the support disk.

According to this tube expansion tool, the contact surface between the cylinder and the disk is tapered, and by tightening the bolt, the disk pushes the cylinder and tries to expand the vibrator. Therefore, if the second pipe expanding tool is used, the pipe will not become constricted during flaring.

Further, the present invention provides a device that fits into a pipe to prevent the pipe from collapsing during flaring, comprising:
A pair of halves that are joined together to form a cylindrical body, and tapped holes, one of which has a right-hand thread and the other a left-hand thread, formed so as to face each other in each of the half halves, and these screw holes. To provide a pipe expansion tool consisting of a composite bolt in which a right-handed threaded bolt and a left-handed threaded bolt are connected back to back, and which is screwed into the pipe.

In this case, the cylindrical body expands or contracts by turning the bolt using a spanner or the like.

(Example) In FIG. 2, the tube expansion tool 27 has four
It includes a divided cylinder body 20. The cylindrical body 20 has a taper in which the inner diameter increases toward both ends. code 2
1.22 are a disk and a support body placed inside the cylinder 20, respectively. Both the disk and the support are disk-shaped, and the outer diameter increases toward the outer end. Reference numeral 23 denotes a bolt, which passes through a center hole 21a of the disk 21 and is screwed into a screw hole 22a of the support body 22. A hexagonal hole 23a is formed in each of the bolts 230, into which the tip of a hexagonal spanner 24 is inserted and turned.

A tapped hole 21b is formed in the center of the disk 21, and 230 bolts are housed therein. code 25
is an extraction handle whose tip is screwed into this screw hole 21b.

Note that an annular coil spring 26 is placed around the cylindrical body 20, which is divided into four parts, to prevent it from falling apart. Reference numeral 20a is a groove in which a spring 26 is accommodated.

When in use, insert the tube expander 27 into the pipe 13 to be flared (FIG. 1) and tighten the bolt 23 with the wrench 24. Then, the disk 21 and the support 22
, the outer diameter of the cylindrical body 20 expands, and the pipe 13
(Figure 2).

If the flaring process is performed as described above, the diameter of the pipe will not become smaller, and the neck will not become narrower as shown by the chain line in FIG. 8.

In addition, so that the first cone 8a and the tube expansion tool 27 do not interfere with each other,
The front end of the tube expander is concave in the shape of a mortar.

After flaring is completed, the bolt 23 is loosened using the spanner 24, the handle 25 is screwed into the tapped hole 21b, and the handle 25 is pulled out from the pipe.

What is shown in FIG. 4 is a tube expander 37 for tubes with a diameter of 65 to 200+W. When it comes to pipes this thick,
Since the neck narrowing phenomenon mainly occurs in the process using the second cone, this tube expander is used only in this process. Therefore, the disk 31 does not have a cone-shaped recess.

The support body 32 does not have a tapered portion, but instead has a protrusion on the circumference, which engages with the groove 20b on the inner surface of the circle W30. In this case, when the bolt 33 is tightened, the disc 3
1 approaches the support 32, and the diameter of the circle 11130 increases.

When pulling it out from the pipe, screw the eye bolt into the threaded hole 31c drilled in the disk 31 and pull the eye bolt to pull it out.

The pipe expanding tool 47 shown in FIG. 6 is for larger pipes.

In this case, the cylindrical body 40 is divided into two halves, and the ends of the halves are formed thick, and screw holes 40c and 40d are bored therein so as to face each other. One of the opposing tapped holes has a right-handed thread, and the other has a left-handed thread. Reference numeral 43 is a composite bolt in which a right-handed threaded bolt and a left-handed threaded bolt are joined back to back, and each has a corresponding tapped hole 40c.
, 40d. Therefore, composite bolt 4
If you turn 3 in a certain direction, each bolt will move back through the tapped hole, increasing the diameter of the cylinder 40, and if you turn it in the opposite direction, each bolt will move forward through the tapped hole, decreasing the diameter of the cylinder. It's supposed to be.

(Effects of the Invention) This invention has the following effects.

In the flare flange manufacturing method according to claim 1, when the flange is formed by pressing a cone against the pipe end, the cylindrical body is fitted inside the pipe, so that the pipe does not become constricted at the base of the flange. do not have.

The tube expanding tool according to claims 2 and 3 is suitable as a certificate body used in the method according to claim 1. In particular, the second aspect of the present invention is suitable for small-diameter pipes because the tightening bolt passes in the axial direction of the pipe, so the bolt can be operated from outside the pipe. The third aspect has a very simple structure and is suitable for large diameter pipes.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the flare machine, Figure 2 is the first tube expansion tool.
Embodiment sectional view, FIG. 3 is a front view of the first embodiment, FIG. 4 is a sectional view of the second embodiment of the tube expansion tool, FIG. 5 is a front view of the second embodiment,
FIG. 6 is a front view of a third embodiment of the tube expansion tool, FIG. 7 is a sectional view of the third embodiment, and FIG. 8 is a sectional view of a flare flange. 4... Rotating shaft 8... Cone 13.
... Vibrator 13b ... Flange 20.
30...Cylinder body 21.31...Disc 22.32...Support body 23.33...
...Bolt 40...Cylinder 40c.

Claims (1)

[Claims] 1. The cones 8a and 8b, which are eccentrically and rotatably attached to the tip of the rotating shaft 4, are pressed against the end of the pipe 13 while rotating the rotating shaft to expand the pipe end. Flange 13a
In the manufacturing method of the flare flange, in order to prevent the pipe from constricting at the base of the flange, cylindrical bodies 27, 3 are inserted inside the pipe during processing of the flare flange.
A method for manufacturing a flare flange characterized by fitting parts 7 and 47. 2. A cylindrical body 20, 3 which is a device that fits into the pipe to prevent the pipe from collapsing during flaring, and which is divided into several parts in the axial direction and whose inner diameter increases toward one end.
0, disks 21 and 31 placed in the cylinder whose outer shape expands toward the outside, and disk-shaped supports 22 and 32 supported by the cylinder so as not to move in the axial direction. and a tube expansion tool consisting of bolts 23 and 33 for tightening the disk to the support. 3. A device that fits into the pipe to prevent the pipe from collapsing during flaring, and is a device that fits into the axially divided cylinder 40 and each of the halves of the cylinder. Consists of threaded holes 40c and 40d formed to face each other, one with a right-hand thread and the other with a left-hand thread, and a composite bolt 43 which is a right-hand threaded bolt and a left-hand threaded bolt connected back to back and is screwed into these threaded holes. Tube expansion tool.