JP3167268B2 - Forming method of the projection of the tube opening - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a projection of a pipe opening formed of a metal material such as ductile cast iron.

[0002]

2. Description of the Related Art FIG. 4 shows a known type of a separation preventing pipe joint. That is, the receiving port 2 is formed at the end of one duct 1 made of ductile cast iron,
An insertion port 4 is formed at an end of the other tube 3, and a mortar lining layer 5 is formed on the inner periphery of each of the tubes 1 and 3. Then, as shown in the drawing, the pipes 1 and 3 are joined together by inserting the insertion port 4 of the other pipe 3 into the receptacle 2 of the one pipe 1.

[0003] In detail, a seal material accommodating groove 6 and a lock ring accommodating groove 7 located on the inner side of the seal material accommodating groove 6 are formed on the inner periphery of the receiving port 2. An annular rubber sealing member 8 for sealing between the inner peripheral surface of the receiving port 2 and the outer peripheral surface of the insertion port 4 is mounted in the sealing material receiving groove 6. A lock ring 9 made of metal is mounted in the lock ring housing groove 7. A centering rubber ring 10 for centering the lock ring 9 is fitted between the outer periphery of the lock ring 9 and the inner periphery of the lock ring housing groove 7.

A lock ring 9 is provided on the outer periphery of the tip of the insertion opening 4.
A projection 11 is formed to prevent the insertion opening 4 from being detached from the receiving opening 2 by engaging with the opening.

[0005] In such a configuration, when the sealing material 8 and the lock ring 9 are mounted in the receiving port 2, the receiving port 2 is closed.
When the insertion hole 4 is inserted into the inside, first, the protrusion 11 pushes out the sealing material 8 and passes through the inner periphery of the sealing material 8,
Similarly, when the projection 11 pushes and spreads the lock ring 9 and passes through the inner periphery of the lock ring 9, the insertion port 4 and the receiving port 2 are joined to each other as shown in the figure.

Conventionally, the projection 11 of the insertion opening 4 is formed as shown in FIG. That is, as shown in FIG. 1A, first, an annular groove 12 is formed on the outer periphery of the insertion opening 4, and the annular groove 12 is formed on the distal end side in the radial direction of the tube 13 and on the opposite side to the distal end. And a tapered surface 14 formed on the substrate. Then, a tight metal ring 15 having a rectangular cross section and formed in the circumferential direction is fitted into the annular groove 12 from the front end side of the insertion opening 4.

[0007] Next, as shown in FIG.
Weld the part corresponding to 14. 16 is the weld.
After that, the front end side of the insertion hole 4 is welded to a welded portion
By welding. At this time, the spatter 18 often adheres to the outer peripheral surface of the ring 15 as illustrated.

[0008] Finally, the protrusion 11 having a predetermined shape as shown in FIG. 1C is formed by grinding or lathing. That is, it is necessary to accurately form the corner 19 at a portion opposite to the distal end of the insertion port 4 so as to be able to reliably engage with the lock ring on the receiving side. On the surface, it is necessary to form the surface smoothly so that the sealing material and the lock ring on the receiving side can be pushed and spread smoothly and pass through the inner circumference.
Moreover, in order to smoothly perform this spreading, it is necessary to form a tapered surface 21 following the tapered surface 20 on the outer periphery of the distal end of the insertion opening 4 in the welded portion 17 having the built-up shape.

[0009]

However, the portions where such welds 16, 17 and spatter 18 are adhered are in a state of high hardness due to the influence of heat during welding and the like, and the portions are grinded. There is a problem that lathe processing involves considerable difficulty.

Accordingly, an object of the present invention is to solve such a problem and to make it possible to easily form a projection of an insertion opening.

[0011]

According to the present invention, a ring having a constant thickness in the radial direction and having an outer peripheral groove formed therein is mounted on the outer periphery of an insertion opening of a pipe. By performing welding, the molten metal is welded inside the groove, and the outer peripheral portion of the welded metal portion is formed so as to swell outside the groove, and at the portion between the ring and the pipe opening around the groove. A penetration portion is formed, and thereafter, a portion of the welded metal portion that protrudes from the groove is removed, and a tip portion of the insertion port and a corresponding ring portion are processed to finish the portion as a tapered surface. is there.

[0012] In this case, since only the portion of the weld metal protruding outside the ring outer peripheral groove needs to be processed, the processing is easy. In addition, the appearance is beautifully finished. By forming a welded portion in the portion of the ring and the pipe insertion hole around the groove, these rings and the insertion hole are welded to each other, so that the other portion, that is, the receiving side which affects the detachment prevention performance of the pipe joint. No welded metal portion is formed in the portion that engages with the lock ring, so that this portion has a corner from the beginning.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1 (a), a ring 27 which can be fitted into an insertion opening 26 of a ductile cast iron pipe 25 is prepared. The ring 27 is formed so as to have an elongated rectangular shape in cross section as shown in the figure, and is formed in a circumferentially split annular shape as shown in FIG. As shown, the dividing portion 24 is formed in an oblique direction. As shown in FIG. 1B, an outer peripheral groove 28 is formed in a portion of the ring 27 which is located at a distance from the tip of the insertion hole 26 when the ring 27 is fitted into the insertion hole 26. ing. This outer peripheral groove 28
As shown in the figure, the groove bottom 29 is formed so that the thickness thereof is as small as possible. In the outer peripheral groove 28, a side portion closer to the distal end of the insertion opening 26 is formed as a side surface 30 in the pipe radial direction, and a side portion away from the distal end of the insertion opening 26 is formed as a tapered surface 31. .

[0014] As shown in FIG.
When one end is aligned with the tip of the insertion opening, the outer peripheral groove 28 is welded to form a welded metal portion 32 in the groove as shown in FIG. This welded metal part 32 is
33 is formed so as to swell outside the groove 28. As welding for this purpose, MIG welding, electric welding or the like is appropriate. Then, a penetration portion 34 is formed in the ring 27 around the groove 28. The penetration portion 34 also extends to the insertion opening 26 of the tube 25 due to the small thickness of the groove bottom portion 29, whereby the ring 27 is fixed to the outer periphery of the insertion opening 26.

Thereafter, as shown in FIG.
Is processed and the corresponding portion of the ring 27 is processed to finish the portion as a predetermined tapered surface 35. Further, the outer peripheral portion 33 of the welded metal portion 32 protruding from the groove 28 is removed.

In this way, it is sufficient to process only the outer peripheral portion 28 of the deposited metal, and since the deposited metal has a relatively low hardness, there is almost no difficulty in the processing. It is also easy to finish the appearance beautifully. No welded metal part is formed in the engagement part 36 with the lock ring on the receiving side, and a predetermined angle can be formed at the engagement part 36 from the beginning, so that the required detachment prevention performance Can be easily applied to the pipe joint. Although it is possible in principle to make the insertion projection 37 with the ring 27 already formed at the time of factory shipment by work in the manufacturing factory, it is also possible to cut the pipe at the site where the pipeline is laid. The protrusion 37 can be formed in the same manner at the installation site.

FIG. 3 is a view for explaining the welding operation of the ring 27. As shown in the drawing, a pair of ring pressing rollers 40 and 41 are arranged along the tube axis direction, and the ring pressing rollers 40 and 41 press and hold both ends of the ring 27 along the tube axis direction. That is, these ring pressing rollers 40, 41 each have large diameter portions 42, 43 and small diameter portions 44, 45, and in the ring pressing roller 41 on the distal end side of the insertion port 26,
One end of the ring 27 is pressed in the tube radial direction by the outer peripheral surface of the small diameter portion 45, and the side surface of the large diameter portion 43 is brought into contact with the end surface of the ring 27 and the distal end surface of the insertion opening 26, so that this ring 27
Is positioned in the tube axis direction. Similarly, the other side of the ring pressing roller 40 presses the other end of the ring 27 in the pipe diameter direction by the outer peripheral surface of the small diameter portion 44 and positions the end surface of the ring 27 by the side surface of the large diameter portion 42. The outer peripheral surface of the large diameter portion 42 is configured not to contact the outer peripheral surface of the insertion opening 26. MI between the ring holding rollers 40 and 41
A G welding torch 46 is arranged and used for forming the weld metal portion 32 inside the outer peripheral groove 28.

In such a configuration, when welding,
MIG welding torch 46 while rotating pipe 25 around the axis.
Is operated to perform welding to form a penetration portion 34.
The ring pressing rollers 40 and 41 rotate while following the rotation of the tube 25 while pressing the ring 27. Then, since both ends of the ring are pressed by the ring pressing rollers 40 and 41, the warpage of the ring 27 due to heat input by welding can be prevented.

[0019]

As described above, according to the present invention, welding is performed on the outer peripheral groove of a ring having a constant thickness mounted on the outer periphery of the insertion opening of a pipe, and molten metal is welded and welded inside the groove. An outer peripheral portion of the metal portion is formed so as to bulge outside the groove, and a penetration portion is formed at a portion between the ring and the pipe opening around the groove, and thereafter, protrudes from the groove in the welded metal portion. And remove the
Since the tip of the insertion hole and the corresponding ring part are machined and the part is finished as a tapered surface, it is easy to machine only the part of the weld metal that protrudes outside the ring outer peripheral groove, so it is easy It can be processed and beautifully finished. In addition, a penetration portion is formed in the portion between the ring and the pipe opening around the groove, and the ring and the insertion hole are welded to each other, so that the other side, that is, the receiving side which affects the detachment prevention performance of the pipe joint. No welded metal portion is formed in the portion that is engaged with the lock ring, so that a corner can be formed from the beginning in this portion. For this reason, the projection of the insertion opening of the tube can be easily formed.

[Brief description of the drawings]

FIG. 1 is a view for explaining a method for forming a projection of a tube opening based on the present invention.

FIG. 2 is a perspective view of a ring in FIG. 1;

FIG. 3 is a diagram illustrating details of the welding operation shown in FIG. 1;

FIG. 4 is a view showing a cross-sectional structure of a conventional anti-separation pipe joint to which an insertion port having a protrusion formed by the method of the present invention is applicable.

FIG. 5 is a view for explaining a conventional method of forming a projection of an insertion opening of a pipe.

[Explanation of symbols]

 25 Tube 26 Insert 27 Ring 28 Outer circumferential groove 34 Penetration 36 Engagement 37 Insert protrusion

Continuation of the front page (51) Int.Cl. ⁷ identification code FI F16L 21/00 F16L 21/00 D // B23K 103: 06 (56) References JP-A-63-161419 (JP, A) JP-A-51 -62138 (JP, A) JP-A-7-266045 (JP, A) JP-A-6-122072 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23K 9/028 B21D 51/16 B23K 9/007 B23K 9/23 F16L 9/02 F16L 21/00 B23K 103: 06

Claims (1)

(57) [Claims] 1. A ring having a constant thickness in the radial direction and having an outer peripheral groove formed therein is mounted on the outer periphery of an insertion opening of a pipe, and the outer peripheral groove is welded, and a molten metal is welded inside the groove. And weld the outer periphery of the welded metal part outside the groove.
Formed so as to rise, and a penetration portion is formed in a portion between the ring and the tube opening around the groove , and thereafter,
Next, the portion of the welded metal portion protruding from the groove is taken out.
As well as the corresponding tip
And the tapered surface
Method of forming a projection of the spigot of the tube, characterized in that that.