JPS5831607Y2 - Back bead cutting tool for inner surface of welded pipe - Google Patents

Description

[Detailed description of the invention] The present invention is configured so that the force based on the cutting resistance applied to the cutting blade when cutting the back bead can be effectively avoided in the back bead cutting tool 1% of the welded pipe, and the shoe is cooled. This invention relates to a back bead cutting tool that is installed so as not to obstruct the flow of water, etc.

A belt-shaped metal material is fed in the longitudinal direction and bent into a C-shaped cross section, and a high-frequency current flowing through an induction coil or electrode provided on the outer periphery of the metal material is applied to the metal material by the action of an impeder provided inside the metal material. When producing a welded pipe by welding the seams using high-frequency heating concentrated on the joint (opening end surface), the back heat generated on the inner surface of the welded pipe has conventionally been dissipated in the direction of movement of the welded pipe within the welded pipe. On the other hand, it is cut and removed by a back bead cutting tool provided on the front side (downstream side) of the impeder.

This back bead cutting tool is equipped with an elastic body or shoe that supports the cutting tool in a predetermined state within the pipe, guides the back bead correctly to the guide, and presses the cutting blade against the back bead with an appropriate force. is installed.

Conventionally, this shoe has generally been brought into contact with the inner surface of the welded pipe at three contact surfaces, although this may vary somewhat depending on surrounding circumstances.

That is, in FIGS. 1a and 1b showing an example of a conventional back bead cutting tool, the back bead cutting tool 1 has horizontal shoes 2a, 2b and a lower shoe 2c on both sides and at the bottom, respectively.
are attached, and by these shoes, the back bead 7 on the inner surface of the welded pipe 6 is correctly guided to the guide groove 5 of the guide 4, and the cutting blade 8 is pressed against the back bead 7 with an appropriate force ( It's Rono.

In the welding pipe 6, there is a cooling water for discharging spatter 9 that falls from the welding point W during welding, cooling an impeder (not shown), lubricating oil, etc. flowing between rolls (not shown). is being distributed, but shoe 2a, 2
If b and 2c are installed as described above,
There was a problem in that the spatter 9 accumulated around the lower joule 2c and obstructed the flow of cooling water.

In other words, in the conventional method, three shoes are attached, and in addition to the space (cross-sectional area) through which cooling water, etc. can flow, is small, the inside of the fusing tube 6, where the spatter 9 tends to concentrate. Because the lower shoe 20 is attached to the bottom of the welding point, the flow of cooling water, etc. is poor, and the spa that falls from the J welding point W cannot be sufficiently drained. The water level in the pipe, such as cooling water, rises and cools the J welding point, which may result in poor joint support at the joint of metal materials.

In the worst case scenario, cooling water overflows from the joints of the metal materials and cools the welding points, making it impossible to form pipes.

Further, there is also the disadvantage that the temple part of the welded pipe 6 may be damaged by the insects 97 accumulated around the lower shoe 2c.

In addition, in the conventional example shown in FIGS. 1a and 1b, the cutting force is attached to the downstream side of the guide 4 with bolts, etc., so the force based on the cutting resistance is applied to the cutting edge. 8, the center of rotation, in other words, the point where the cutting blade 8 is fixed by the bolt is located forward (downstream) from the cutting edge in the direction in which the welded pipe 6 is fed. As the cutting blade 8 attempts to rotate counterclockwise (in the same figure) around the fixed point due to the force applied to the cutting edge, the cutting blade bites into the inner surface of the welded pipe 6 more than necessary. If you try to cut it, the cutting force will increase and the molten tube 6Vc will be easily torn, cracked, or cracked. Therefore, there is an inherent problem that causes cutting defects.

Also, due to the above force, the end of the back bead cutting tool on the rear (upstream side) with respect to the direction of movement of the metal material may be lifted by the upper man. This also causes an undesirable phenomenon in which the impeder holder and the like connected to the end of the back bead cutting tool are simultaneously moved toward the welded portion of the metal material.

The present invention was developed against the background of the above-mentioned circumstances.The purpose is to make the coolant circulation space in the welded pipe as large as possible, and to prevent spatter from accumulating at the bottom of the welded pipe. In order to effectively remove the back bead on the inner surface of the welded pipe and to avoid cutting damage to other parts as much as possible, the cutting force applied to the cutting blade when cutting the back bead is An object of the present invention is to provide a back bead cutting tool configured so as to be able to avoid the applied force.

In order to achieve this purpose, the present invention has nine features in which the cutting blade of the back bead cutting tool is shaped like an abbreviation, consisting of a vertical cutting blade part and a horizontal mounting part. In addition to having a side surface shape, the cutting blade enters the lower side of the guide at the horizontal attachment part □, and the cutting blade is located upstream of the cutting blade part with respect to the traveling direction of the force transfer tower connecting pipe. The 12 shoes were attached with pins to the inner part □ of the guide so that they were on the sides, and the 12 shoes were imaginary bead cut so that they were almost symmetrical to the vertical edge passing through the axis of the welded pipe. By providing it at the bottom of the tool and bringing it into contact with the inner surface of the welded pipe, this back bead cutting tool is supported in the welded pipe so that it is in its original state, and is also aligned with the axis of the three shoes. Opening angle from 400~
I made it so that it was 120'.

)' □ ゛Hereinafter, in order to clarify the present invention more specifically, a first embodiment of the present invention will be described in detail based on the drawings.

Back bead cutting tool 60 of this embodiment shown in FIG. 2 a = b
consists of the members shown in Figures 3 to i.

First, the cutting tool main body 20 shown in FIGS. 3a and 3d has a bottom plate portion 21. a pair of upright parts 2 provided at a predetermined distance;
7. The upright part 23 of the dying J that connects these uprights 81322
It is provided with a pair of protruding capes 2 protruding in the horizontal force direction from the upright part 23 of the 7i bib.

゛Then, the bottom plate portion 21, both upright portions 22, and the upright portion 2
A space 25 is formed by 3.

this is. Elastic body 30, cutting blade 35, and guide 4 described later
5 in this space 25.

Also. A long hole 26 is provided in the upright portion 22, and a circular hole 2T is provided in the J protrusion m24'.

Furthermore, shoes 28 are fixed to each corner formed by the bottom plate part 21 and the pair of upright parts 23.

These two shoes 28 are long rod-shaped or columnar members (generally made of copper alloy) whose abutting portions 28', which are brought into contact with the welded pipe, have an arcuate surface so that they match the inner surface of the welded pipe. ), and the opening angle (a in Fig. 3 d) formed at the corner with respect to the center of the assembled back bead cutting tool 60 (as described later, this approximately coincides with the axis of the welded pipe). ), but here they are fixed at approximately 90°.

The elastic body 30 shown in FIGS. 4a and 4b has a lower surface (fourth
In the figure, the right side surface) 30a is brought into close contact with the bottom plate portion 21 of the cutting tool main body 20, and is housed in the lowest part of the space 25.

The cutting blade 35 shown in FIGS. 5a to 5d has its overall width matched to the width of the space 250, and its side surface shape is an abbreviated shape consisting of a horizontal portion 36 and a vertical portion 37. ing.

Of these, a circular hole 38 is diagonally bored in the vertical portion 37, and the top edge thereof serves as a cutting edge portion 39.

Further, a pin hole 40 is formed in the horizontal portion 36 in a direction perpendicular to the upper surface 36a thereof.

The guide 45 shown in FIGS. 6a to 6d has the same width as the space 25 as a whole, and has a substantially inverted shape consisting of a horizontal portion 46 and a vertical portion 47, and the upper surface 45a has a guide A groove 48 is formed.

Further, on the lower surface 46a of the horizontal portion 46, a pin 49 that is fitted into the pin hole 40 of the cutting blade 35 is provided vertically downward, while in the vertical portion 47, a circular hole 50 is provided at right angles to the side surface of the pin 49. It is perforated.

Cutting tool main body 20 and elastic body 30 shown in FIGS. 3 to 6
, when assembling the back bead cutting tool 60 shown in FIG. Bring it into close contact.

Next, the cutting blade 35 is placed on the elastic body 30.

Next, the guide 45 is inserted and the pin 49 is fitted into the pin hole 40 of the cutting blade 35, and then the pin 55 having the same length as the width of the two upright parts 22 of the cutting tool body 20 is inserted into the upright part 22.
It is inserted into the circular hole 50 of the vertical portion 47 of the guide 45 through the elongated hole 26 .

The back bead cutting tool 60 assembled in this way is
As is clear from FIG. 2, the guide groove 48 of the guide 45
guides the back pin 70 on the inner surface of the welded pipe 65, which is fed in the direction of arrow C in the same figure, and the abutting portions 28' of the two shoes 28 meet the perpendicular line passing through the axis of the inner surface of the welded pipe 65 (see FIG. 2). (Illustrated as T in the figure) at two symmetrical contact surfaces 65', and is connected to a predetermined member 57 (for example, an impeder holder that holds the impeder) by a screw member 56. It is maintained in the state shown in this figure.

In this embodiment, the two shoes 28 are thus fixed to the diagonally lower corners of the back bead cutting tool 60 (see FIG. 2).

A large space is secured between the back bead cutting tool 60 and the inner surface of the welded pipe 65 for the circulation of cold water, so that the back bead cutting tool does not obstruct the circulation of cooling water as in the conventional case. Spats 15 fall from the weld W without any problem.
is completely turned to the left (Fig. 2a) by a relatively small amount of cooling water.
).

Furthermore, since a sufficient space is secured between the lower surface 65a of the back bead cutting tool 60 and the welded pipe 65, even if the span tough 5 falls a lot, the fallen spatter will be The spun tough 5 is reliably carried away by the cooling liquid flowing in the space, and does not accumulate at the bottom of the welded pipe 65.

Therefore, the water level in the welded pipe 65 does not rise due to poor circulation of the cooling water and cool the welding point W, and the inner surface of the bottom part of the welded pipe 65 is There will be no damage caused by the span tough 5 being caught between the shoe 28 and the shoe 28.

Moreover, in the back bead cutting tool 60 of this embodiment,
When cutting the back bead 70, the cutting blade 35 has its attachment portion (
When a force is applied to rotate the hole 40 in the counterclockwise direction in FIG. 2a as shown in FIG. The vertical portion 37 is also elastically deformed in a direction that is larger than the 90° angle formed with the horizontal portion 36.

Moreover, at this time, the left half of the elastic body 30 (also in FIG. 2a) is also elastically deformed at the same time.

Therefore, even if a large cutting resistance force is applied, the cutting edge portion 39 of the cutting blade 35 moves in the direction away from the inner surface of the welded pipe 65 (see Fig. 2a).
), it escapes to the lower left), and thus the Ura Be-4
With the removal of '70, the situation where the cutting edge portion 39 digs into the welded pipe 65 is effectively avoided, and the welded pipe 65 does not become thinner.

Further, the cutting edge portion 39 is not easily damaged or damaged.

Furthermore, there is no longer any possibility that the end of the cutting tool 60 connected to the impeder holder or the like is lifted upwards significantly, causing various inconveniences.

In addition, in this embodiment, the elastic body 30 provided below the cutting blade 35 aims to further facilitate the displacement of the cutting blade part 39 by its intervention.
Since the elastic body 30 itself has an L-shape and is easily elastically shaped, it is not essential to provide such an elastic body 30, and instead, a mere spacer may be provided. It is also possible to do so.

It goes without saying that the present invention is not limited to the above-mentioned embodiments, and that changes and modifications can be made as appropriate without departing from the spirit thereof.

For example, the opening angle of the shoe can be arbitrarily selected within the range of 400-12o0°, particularly preferably 800-100'.

However, this opening angle should be less than 40°, and 1
An angle of 20° or more must be avoided.

In other words, by setting the opening angle of the shoe to less than 400 degrees, the shoe is brought into contact with the vicinity of the bottom of the welded pipe, and in this case, spatter is less likely to flow out, and the posture of the back bead cutting tool is becomes unstable,
This is because it is necessary to provide a horizontal shoe.

Furthermore, if the opening angle of the shoe exceeds 1200°, the back bead cutting tool may rotate around the axis of the welded pipe if force imbalance occurs, and furthermore, if the opening angle of the shoe exceeds 120°, the back bead cutting tool may rotate around the axis of the welded pipe. If the size exceeds the limit, the shoe will come into contact with the vicinity of both sides of the welded pipe, making it difficult to adjust the force that presses the cutting blade against the back bead, and the back bead cutting tool will become unstable, causing the lower shoe to come into contact with the lower shoe. This may cause inconveniences such as the need to provide additional equipment.

Further, the thickness and length of the shoe can be arbitrarily changed in relation to the shape of the welded pipe, except that the opening angle of the shoe is adjusted to satisfy the conditions of the present invention.

As detailed above, according to the present invention, in cutting and removing the back bead, a cutting blade with an abbreviated side shape is used, and the vertical cutting blade part guides the mounting part in the horizontal direction. By being located downstream of the attachment part to the welded pipe (forward in the direction of movement of the welded pipe), the situation where the cutting edge of the cutting blade digs into the welded pipe more than necessary can be avoided. In addition, the horizontal mounting part of the cutting blade is inserted under the guide and attached to the guide with a pin, which eliminates the need for detailed positioning of the cutting blade and speeds up cutting work. Moreover, by arranging the two shoes within a predetermined angular range, it is possible to effectively drain away spatter falling from the welding area without circulating cooling water more than necessary. The welding point is no longer cooled by cooling water, and the back bead cutting tool itself can be made more compact, among other excellent effects.

[Brief explanation of the drawing]

FIGS. 1a and 1b are a front view and a sectional view taken along line II of the conventional back bead cutting tool. Figures 2a and 2b are a front view and left side view showing an embodiment of the present invention, and Figures 3a to d &! Among the elements constituting the embodiment shown in FIG. 2, the front view of the cutting tool body,
A plan view, a left side view, and a right side view, FIGS. 4a and 4b are the same plan view and right side view of the elastic body, and FIGS. 5a to 5d are views corresponding to FIGS. 3a to d of the cutting blade. , FIGS. 6a to 6d are views corresponding to FIGS. 3a to d of the guide. 20... Cutting tool body, 25... Space,
28... Shoe, 28'... Contact part,
30...Elastic body, 35...Cutting blade, 4
5... Guide, 60... Back bead cutting tool, 65... Welded pipe, 65... Contact surface, γ0... Back Beat', 75...spatter.

Claims (1)

[Scope of claim for utility model registration] A guide guides the back bead formed on the inner surface of a welded pipe manufactured by bending a strip-shaped metal material into a C-shaped cross section while feeding it in the longitudinal direction and welding the seam. Then, with a back bead cutting tool that cuts and removes the back bead with a cutting blade disposed downstream of the guide, the cutting blade is aligned horizontally with the cutting blade part in the perpendicular direction. The horizontal mounting part is inserted under the guide, and the mounting part is oriented with respect to the traveling direction of the welded pipe. Attach the guide with a pin to the lower part of the guide so as to be upstream of the cutting edge, and attach the two shoes to the back bead so that they are approximately symmetrical with respect to a perpendicular line passing through the axis of the welded pipe. By being provided at the lower part of the cutting tool and brought into contact with the inner surface of the welded pipe, the back bead cutting tool is supported in a predetermined state within the welded pipe, and the shaft center of the two shoes is A back bead cutting tool for the inner surface of a welded pipe, characterized in that the opening angle formed by the inner surface of the welded pipe is 400 to 1200.