JP2006075898A - Aluminum and aluminum alloy spiral tube, and its manufacturing method, friction stir welding method, and structure of friction stir-welded aluminum and aluminum alloy - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aluminum and aluminum alloy spiral tube of high quality and highly efficient manufacture and to establish its manufacturing method, to prevent occurrence of an unjoined part on the rear face of a material to be joined in a friction stir welding method, and to make such rear face a decorative face to be externally viewed. <P>SOLUTION: The spiral tube is manufactured by continuous manufacturing process including: a forming means by which a belt-like material is formed into a circular spiral shape; and a friction stir welding means in which a rotary tool (7) comprising a pin (5) and a shoulder (6) with a recess (8) around the pin is arranged in the inner circumferential face in the butting part of the formed body (4), in which, while rotating the tool, the pin is inserted till the shoulder part bites the butting part with the sweepback angle (θ), and in which a back bead is formed, while producing a burr, by a rotary roller (10) having also a role of a backing material, on the outer circumferential face of the abutting part of the formed body. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a spiral tube of aluminum and aluminum alloy, a manufacturing method thereof, a friction stir welding method, and a structure thereof.

  Table 1 shows the production methods applied to conventional aluminum and aluminum alloy pipes in relation to the diameter size of the pipes (see, for example, Non-Patent Document 1 and Non-Patent Document 2). The seamless pipe includes a drawn pipe and an extruded pipe. The maximum outer diameter of the drawn tube is about 200 mm, and the maximum outer diameter of the extruded tube is about 420 mm. The jointed pipe includes a high-frequency induction heating welded pipe and an arc welded pipe. The maximum outer diameter of the high frequency induction heating welded tube is about 100 mm. The outer diameter size of the arc welded pipe is about 200 to 1,500 mm, and its manufacturing range is the widest. However, from the viewpoint of weldability, the 2000 series, 6000 series and 7000 series aluminum alloys do not have a high-frequency induction heating welded arc or an arc welded pipe. In addition, such arc welded pipes have the disadvantage that in terms of quality, poor fusion, cracks, blow holes, etc. are likely to occur. Furthermore, when manufacturing many types of pipes having different diameters, there is a drawback in that strips having various types of widths corresponding to the diameters must be prepared. The welding direction of the welded pipe is the longitudinal direction of the pipe. When internal pressure is applied to the pipe, the maximum stress is applied in the longitudinal direction, which is twice the stress generated on the circumference of the pipe.

  In recent years, friction stir welding methods have been developed, and there are 200 domestically applied patent documents, and numerous research announcements and explanations are featured in the Journal of the Japan Welding Society. One of the features of the friction stir welding method is that, since no filler material is added, the joint thickness is theoretically thinner than the base material of the base material so that the joint is sound. It is. This is because there is a material loss as a “burr” during joining and a lack of material volume due to butt accuracy. For example, the thickness reduction due to the “undercut” of the shoulder surface biting amount (t) described in Patent Document 1. Therefore, the application of such a joining method is not suitable for a strict regulation of wall thickness tolerance. On the other hand, in order to solve the disadvantages of the friction stir welding method, many methods have been proposed in which a convex portion (14) is provided at the abutting portion, and the width equal to the diameter of the shoulder portion (6) of the rotary tool (7). Is disclosed (for example, Non-Patent Document 3). However, as shown in the upper diagram of FIG. 12, when the rotary tool (7) is encroached on the entire surface of the shoulder (6) perpendicularly to the material to be joined (9), before heating by friction occurs. The convex portion (14) is cut by the shoulder portion and the effect is not sufficiently produced. In addition, as shown in the lower diagram of FIG. 12, when the shoulder surface is bitten into the surface of the material to be joined with a receding angle (θ), the upper surface of the joining portion is formed in an arc shape, and the convex shape The left part (15) of a part arises, and the post process which deletes this left part after joining is needed.

  On the other hand, in the friction stir welding method, a backing material method that can be removed after joining is applied, and a defect of joining failure occurs on the back surface of the material to be joined that the backing material contacts, and many solutions have been proposed. (For example, Patent Document 2). However, with such a proposal, it is difficult to eliminate the bonding failure on the back surface although it decreases. The reason is that it is understood that it is impossible to simultaneously proceed the opposite phenomena of heating by frictional heat and cooling by the backing material. Patent Document 3 discloses a technique in which a friction stir welding method in which a spiral tube is joined from the inner surface of a spiral tube to a spiral butt portion is disclosed. The reason for joining from the inner surface is that the outer peripheral surface is clean and the pressure reaction force of the rotary tool (7) can be received by the inner peripheral surface of the tube. However, there is no disclosure of any means for making the appearance of the outer peripheral surface of the pipe clean and means for preventing the bonding failure of the outer peripheral surface (what kind of backing method is adopted, etc.). In addition, the spiral tube has a larger number of windings of the strip material than the length of the tube, and the length of the joining portion becomes longer. If the forming process and the joining process of the pipe are made independent, the production efficiency Has a disadvantage that it becomes extremely low.

    Patent No. 2792233 Patent Publication     JP 2001-71155 A     JP 11-226756 A     JIS H 4080, aluminum and aluminum alloy seamless pipe     JIS H 4090, aluminum and aluminum alloy welded pipe     Okamura Hisanobu, Characteristics of Friction Stir Welding (FSW) and Application in Japan, Journal of the Japan Welding Society, 69 (2000), page 14, Fig. 8

  The problem to be solved by the invention is to solve the above-mentioned problems, as described below. The present invention is to provide high-quality and high-efficiency production pipes for aluminum and aluminum alloys including 2000 series, 6000 series and 7000 series having the same outer diameter size as arc welded pipes and to establish a production method therefor. And in the case of a spiral tube, the maximum stress generated by the action of the internal pressure in the tube is the longitudinal direction of the tube, and since it is not a spiral joint location, by applying a friction stir welding method with high joint quality, It has been noted that there is little trouble even if the thickness of the joint portion is reduced as described above. Specification of tolerance of thickness of arc welded pipe of aluminum and aluminum alloy (Non-patent document 2) (Nominal diameter 450A or less: + 15%, -12.5%, Nominal diameter 450A exceeding: + 15% -10%), the thickness reduction due to friction stir welding is 10% or less, and this tolerance is considered to be sufficiently satisfied. In addition, as a method for increasing the manufacturing efficiency of such a spiral tube, attention was paid to the fact that the tube forming means and the tube joining step may be made continuous.

  In addition, when the rotary tool (7) to which the receding angle (θ) is applied is arranged on the inner peripheral surface of the pipe and joined from the inner peripheral face, the joining portion can be formed into an arc shape. We also paid attention to the fact that the inner peripheral surface can be imitated. Furthermore, even in the case of a spiral tube, it is necessary to effectively use the convex portion of the butt portion provided in advance for joining in response to a case where the tolerance of the thickness of the joint portion is required to be smaller. We also focused on the method that left no part left.

  Another problem is to prevent a back side joining failure, which is a disadvantage of the friction stir welding method using a backing material that can be removed after joining, and to make the back side a cosmetic surface that can be visually seen. By providing a time lag (time delay) between the plastic flow zone agitated by frictional heating at the back of the butt location and cooling and solidification of the plastic flow zone by the backing material, it is possible to prevent poor bonding on the back side. I noticed. Then, attention was paid to the application of the rotary roller (10) as a backing material. Further, if the plastic flow zone is appropriately expanded at a time point before midnight of the rotary roller (10), and the plastic flow zone is cooled and solidified at the time point of time of the rotary roller, We also paid attention to the fact that it can be molded into the desired back bead shape (slightly inflated, slightly dented, flattened) while producing a flash, and it can be finished into a cosmetic surface that can be visually seen. Here, the “back bead” means that the back surface of the abutting portion (the outer peripheral surface in the case of a tube) is plastically flowed and stirred, and the plastic flow zone portion is cooled and solidified while being formed by a rotating roller. Say part. That is, in order to be formed into a back bead shape, the occurrence of “burrs” is indispensable, and most of the flashes are thinly rolled and removed by a rotating roller. If there is a small gap between the roller and the material to be joined, the flash may remain, but since it is rolled thinly, it can be easily removed and does not cause any trouble. Absent. From the results of many experiments, when the occurrence of “burrs” on the back surface can be confirmed, it has been found that there is no bonding failure on the back surface, which greatly contributes to quality control in the bonding process as will be described later.

  According to the present invention

Claim 1

as well as

Claim 2

The aluminum and aluminum alloy spiral tubes described in 1) and the production method thereof are as follows. Roll forming means (1, 2) for forming a circular spiral so that both side surfaces (a, b) of the strip (3) abut each other, and the abutting locations (a, b) of the molded body (4) ) Is provided with a rotating tool (7) comprising a pin (5) on the inner peripheral surface and a shoulder (6) having a concave surface (8) around the pin, and the pin is moved backward (θ) while rotating the tool. Until the shoulder portion bites into the abutting portion, and the outer peripheral surface of the shaped portion is joined to the outer peripheral surface of the abutting portion by a rotating roller (10) that also serves as a backing material. -It is manufactured by the continuous process of the friction stir welding means which shape | molds a door (FIG.1, FIG.2, FIG.3, FIG.4).

  According to the present invention

Claim 3

as well as

Claim 7

The friction stir welding method for aluminum and aluminum alloy and the structure thereof described in 1) are as follows. A rotating tool (7) comprising a pin (5) and a shoulder (6) having a concave surface (8) around the pin is provided on one surface of the abutting portion of both the workpieces (9), and the tool is rotated. Rotating roller with a receding angle (θ) while the shoulder is inserted until the shoulder part bites into the abutting location, and also serves as a backing material on the other side of the abutting location of both materials to be joined It is characterized by having a means for forming a back bead while producing a burr according to (10) (FIG. 5).

  According to the present invention

Claim 4

In the friction stir welding method described in claim 3, as a dependent claim of claim 3, the pin (5) has a tapered spiral shape and is joined while rotating the rotary tool (7) in the direction opposite to the screwing direction of the pin. It is characterized by.
According to the present invention

Claim 5

According to the friction stir welding method described in claim 3, as a dependent claim of claim 3 or claim 4, the rotary tool (7) comprises an assembly structure of a pin (5) and a shoulder (6), and the length of the pin It has a precision screw structure that can be finely adjusted.
According to the present invention

Claim 6

In the friction stir welding method described in claim 3, as a subordinate claim of claim 3, claim 4 or claim 5, the protrusions (14) having a width smaller than the minimum diameter of the pin (5) at the abutting locations of the two materials to be joined. ) To be joined.

The invention's effect

  With the completion of the present invention, high-efficiency production of spiral tubes having a diameter of 200 mm or more of aluminum and aluminum alloys including 2000 series, 6000 series and 7000 series is achieved, which contributes to a reduction in production cost.

  Further, by preventing poor bonding on the back surface of the friction stir welding method, it is possible to provide higher quality bonding, and not only on the outer peripheral surface of the spiral tube but also on the back surface of other friction stir welding structures. A cosmetic surface that can be visually seen without introducing a special finishing process can be finished, which contributes to man-hour reduction and cost reduction. It should be noted that the presence or absence of backside bonding failure can be determined by checking only the presence or absence of backside flash, and the quality control in the joining process is significantly facilitated.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the aluminum and aluminum alloy spiral tube and the manufacturing method thereof according to the present invention will be described in detail below.

  A strip (3) of aluminum or aluminum alloy having a predetermined width may be prepared, and the α angle portion may be cut off as shown in FIG. This is because the length (c) of the cut-off is the circumferential length of the molded body (4). Then, the strip (3) is supplied to a molding machine as shown in FIG. 1 at a supply angle (β) and wound in a circular spiral shape so that both side surfaces (a and b) of the strip collide. It is good also as a roll shaping | molding means used as a molded object (4). FIG. 1 shows two drive rolls (1) and one pressurization roll, but the molded body depends on the positional relationship between the drive rolls and the pressurization roll. Adjust the radius of curvature.

  FIG. 7 shows the relationship between the cutting angle (α) of the band width of the predetermined width (w), the pitch length (p) of the molded body (4), and the diameter (d) of the molded body (4).

Number 1

as well as

Number 2

Find and show from. Where d is

Number 1

      p = w / sin α

Number 2

d = w / 3.14 cos α
Substantially, it is determined by the distance between the drive rollers and the positional relationship between the pressure rollers as described above.

  The diameter of 200 to 1,500 mm targeted by the present invention may be achieved with one type of band material. For that reason, when applying 45 or more as α, when applying 60 degrees or more and when applying 75 degrees or more, the bandwidth is set.

Number 2

Was obtained by transforming. That is, to d

Number 2

The deformation formula of w = d × 3.14 cos α
The value of 200 was substituted, and the values of 45 degrees, 60 degrees, and 75 degrees were substituted for α. In addition, the supply angle (β) and the pitch length (p) of the strip for each diameter

Number 3

When

Number 1

I asked for it. These are shown in FIG. From this, the angle of α to apply is 45 degrees or more

Number 3

β = 90−α
In this case, especially when d is a small diameter of 500 mm or less, the change in the pitch length is large, and strict management of the supply angle β of the strip is important. On the other hand, when α is 75 ° or more, the fluctuation range of p with respect to d is remarkably small and β can be easily managed. Is significantly longer. Therefore, application of 60 degrees or more as α is considered appropriate.
On the other hand, when the diameter of the tube is limited to a specific size, the band width may be changed for each diameter. FIG. 9 shows the relationship between d and w when a constant value of 75 degrees is applied as α.

Number 2

It is obtained from the deformation formula of By doing so, it is possible to apply a material having a wide band width (w) in proportion to the diameter (d), thereby achieving further high-efficiency production. Further, a predetermined range may be grouped, and one type of band material may be prepared for each range.

  In the friction stir welding means to which the present invention is applied, bonding is performed from the inner surface of the molded body (4). This is because the number of flashes is remarkably increased when joined from the outer surface of the molded body. For this purpose, a rotary tool (7) comprising a pin (5) and a shoulder (6) having a concave surface (8) around the pin is arranged on the inner surface of the molded body (FIG. 2). The concave surface around the pin (5) is that the friction heating zone is limited to the vicinity of the insertion pin, and the bulging portion of the surrounding material to be joined by the insertion of the pin escapes to the concave portion, and the friction at this portion This is because the portion where the heat generation is remarkably generated and plastically fluidized serves to fill and replenish the volume of the pin traces due to the progress of the rotary tool (7).

  In the friction stir welding means to which the present invention is applied, the pin (5) is inserted with the receding angle (θ) while rotating the rotary tool (7) until the portion of the shoulder (6) bites into the abutting position. This is because if the angle of θ is increased, the radius of curvature of the arc shape at the joint is reduced, and the inner peripheral surface can be made to follow by adjusting the angle of θ. Moreover, the application of such a receding angle can also enhance the effect of pre-thickening the abutting portion used for preventing the thickness reduction of the joint as shown in FIG.

  In the friction stir welding means to which the present invention is applied, the back bead is generated while the flash is generated by the rotating roller (10) having the role of a backing material on the outer peripheral surface of the butted portion of the molded body (4). Is formed (FIGS. 2, 3 and 4). Provide a time lag (time delay) between the back bead molding and cooling solidification by the rotating roller (10) of the backing material against the back side bulge by stirring of the plastic flow zone by friction heating, and the back side This is to prevent the bonding failure and to form such a portion into a desired shape. Therefore, the shape of the rotary roller (10) may be a shape that follows the outer peripheral surface of the molded body (4), or the back surface of the joint portion of the molded body (4) is slightly swollen or slightly dented. In this way, the portion in contact with the roller (10) may be slightly dented or slightly inflated to have a desired shape. As shown in FIG. 2, the joining position as viewed in the longitudinal direction of the molded body is desirably the 1st winding number on the lower surface of the molded body. This is because the arm (11) for the rotary tool (7) is not too long. The mounting shaft of the rotating roller (10) is perpendicular to the abutting surfaces (a, b) of the molded body (4). This is because the feeding (19) in the longitudinal direction of the molded body is given to the smooth as will be described later.

The spiral tube manufacturing method according to the present invention is an application of a continuous process of roll forming means and friction stir welding means. This is for high-efficiency manufacturing. In order to achieve this, it is necessary to match the feeding speed of the strip (3) with the joining speed of the molded body (4). Here, the diameter of the driving roller (1) is D ₁ , the diameter of the rotating roller (10) is D ₂ , and the rotational speed of the rotating roller set to give an appropriate joining speed is set. When N ₂ , the rotational speed N ₁ of the drive roll is

Number 4

To the value obtained from

Number 4

N ₁ = (D ₂ / D ₁ ) N ₂ × sin α
Must be set. The two drive rollers (1) (not shown in FIG. 2) are extended so as to be in contact with the position where the molded body (4) is joined, and the rotary roller (10) is also driven. It is desirable to be a source. This is because the upper part and the lower part of the outer peripheral surface of the molded body (4) are sandwiched, and the rotation (18) and feed (19) that overcome the friction stir welding are applied to the molded body smoothly by using three places as driving sources. . In this case, gate-shaped columns connected by beams are built on both sides of the molded body (4) so that the tip of the drive roll (1) does not escape upward, and the drive roll is placed on the beam. The front end may be supported, and the drive roll may have a both end support structure.

As means for preventing the opening of the butt due to the insertion of the pin (5), temporary fixing welding may be performed prior to the friction stir welding. Temporary fastening welding is desirably intermittent heat welding with small heat input by automatic tag welding at 17 points shown in FIG. In this case, although the 2000 series, 6000 series and 7000 series aluminum alloys are liable to cause microcracking, such a portion is plastically flowed and stirred by friction stir welding, and the microcrack disappears.
In addition, a rolling device (12, 13) as shown in FIG. 10 is installed as a part of the continuous process before the forming process of the strip (3), and convex portions (14) are formed at both ends of the strip by slight rolling. As shown in FIG. 11, the convex portion is provided by means of sandwiching the rotary roller (16) connected to the arm (11) for attaching the rotary tool (7) prior to the friction stir welding as shown in FIG. You can do it. Two or more such rotation rollers may be provided. In this case, a ring shorter than the pitch length (p) of the molded body (4) is connected to the pressure roll (2) so that the convex portion (14) is not crushed by the pressure roll (2). It is desirable to fit and provide a relief part of the convex part (14).
Further, as shown in FIG. 1, a guide roller (21) and a rotation-free stopper (22) that moves (19) to match the normal pipe forming speed may be used. This is to prevent the abutment surface from opening due to the insertion of the pin (5) or the like so as not to cause an abnormal increase in the pipe making speed. The moving speed of the rotation-free stopper matched to the normal pipe making speed is

Number 5

Ask from. The moving speed of the stopper (22) may be electrically controlled.

Number 5

    Rotation free stopper moving speed = joining speed × cos α

  Next, the best mode for carrying out the friction stir welding method for aluminum and aluminum alloy and the structure thereof according to the present invention will be described in detail below. The friction stir welding method and the friction stir welding means for the structure according to the present invention are essentially the same as the above-described spiral tube and the friction stir welding means for the manufacturing method thereof, so the description of the overlapping parts is omitted. To do.

  In the friction stir welding means to which the present invention is applied, the pin (5) may have a tapered spiral shape and may be joined while rotating the rotary tool (7) in the direction opposite to the screwing direction of the pin. This is because, in combination with the application of the rotary roller (10), the effect of supplying the plastic flow zone to the back surface and promoting the forming of the back bead is remarkably increased.

  The rotary tool (7) applied in the friction stir welding means of the present invention has an assembly structure composed of a pin (5) and a shoulder (6), and has a precision screw structure capable of finely adjusting the length of the pin. Also good. Combined with the application of the rotary roller (10) described above, the plastic fluidized portion immediately before the molding of the back bead is adjusted to an appropriate bulge amount, and there is an effect of suppressing the generation of flash as much as possible. Because.

  In the friction stir welding means to which the present invention is applied, a convex portion (14) having a width smaller than the minimum diameter of the pin (9) may be provided at the abutting portion of both the workpieces (9). This is because, in a joined structure other than the spiral tube, the thickness tolerance of the joined portion may be required to be smaller. Further, as shown in FIG. 5, the rotary roller (10) can be provided with a recess, and the back bead can be molded into a smooth extra shape (η is 120 degrees or more). This is because there is an effect. You may provide this convex part (14) in the one surface of a butt | matching location, or both surfaces. Moreover, you may insert | pinch what has I shape of the same alloy as a to-be-joined material in a butt | matching location. The reason why the width of the convex portion (14) is made smaller than the minimum diameter of the pin (5) is that most of the convex portion is effectively used for joining, and is left behind as shown in the lower diagram of FIG. This is because the portion (15) hardly occurs.

An aluminum alloy 6061, an O material, a width of 407 mm of the strip (3), and a thickness of 5 mm of the strip are prepared, and a spiral shaped body (4) having a diameter (d) of 500 mm is prepared using the roll shown in FIG. The strip was formed at a supply angle (β) of 15 degrees (α is 75 degrees). In this case, the pitch length (p) of the molded body is 421 mm. The following joining conditions were adopted as friction stir welding linked to the molding process. A rotary tool (7) having the shape shown in FIG. 4 is used, the rotational speed is 2,000 times / minute, the joining speed is 1,300 mm / minute, and the rotary tool (10) shown in FIG. The bead shape is formed flat, and the shoulder (6) bites on the inner surface is 0.3 mm. The rotational speed (N ₁ ) of the drive roll ( ₁ ) was set to 2 times / minute so that the joining speed and the supply speed of the strip were equal (D ₁ and D ₂ were both 200 mm, N ₂ was 2. 07 times / min). In addition, in order to prevent the opening of the abutting surface by inserting the pin (5), temporary fixing by TIG welding is performed at 17 points shown in FIG. 1, and the length of about 30 mm is intermittent for every 90 ° rotation of the molded body (4). Welding was performed automatically. Then, the forming process of the spiral tube and the friction stir welding process were interlocked to finish the spiral tube having a length of 5 m.

  A dye penetration test (JIS Z 2343) was conducted over the entire back bead line of the friction stir welded portion of the 5 m long spiral tube, and the presence or absence of a joining defect including a joining failure was examined. It was a defect. Furthermore, the test piece of the cross section in arbitrary 10 positions was cut out, and the microscope observation of 100 times and 400 times was performed, but joining defects, such as a joining defect, were not observed. The spiral tube was subjected to a T6 heat treatment, and the mechanical properties were examined centering on the joint, and it was confirmed that the specified value (JIS H 4080) of the mechanical properties of the extruded tube was sufficiently satisfied.

  An aluminum alloy 5052, O material, a plate thickness of 10 mm, and a length of 2 m were butted together with an I-type insert (same alloy) interposed therebetween, and friction stir welding was performed. The following joining conditions were adopted as friction stir welding. The rotary tool (7) has an assembly structure of a pin (5) and a shoulder (6), and has a precision screw structure that can finely adjust the length of the pin (5). The shoulder (6) has a concave surface. The pin (5) has a tapered left-handed spiral shape, and is set with a right rotation speed of 800 rotations / minute, a receding angle (θ) of 3 degrees, and a welding speed of 300 mm / minute, as shown in FIG. With the backing roller (10), the back bead shape was formed into a smooth convex shape while generating flash. The width of the I-type insert is the same as the minimum diameter of the pin (5), 1 mm on the back side, 2 mm on the front side, protrudes from the surface of the material to be joined (9), and the insert is Teg welded to the material to be joined Was temporarily fixed to obtain an example of the present invention. As a comparative example, an ordinary backing material that can be directly butted together and removed after joining without using an I-type insert was used. In both the present invention and the comparative example, the tip of the pin (5) is set to a position 1 mm from the bottom surface of the material to be joined (9), the rotary tool (7) is fixed, and the material to be joined is joined while moving. . The amount of biting of shoulder (6) was 0.3 mm in the comparative example, and until the present invention was in contact with the surface of the material to be joined.

  Dye penetrant flaw detection was performed on the entire back surface of both joined bodies, but a joining defect was found in a portion corresponding to the abutting surface of the comparative example. In the present invention, the surplus height was about 0.5 mm. A smooth shape with a toe angle (η) of about 160 degrees was obtained, and no bonding defects were observed. In addition, in the microscopic observation, a clear bonding failure was recognized in the comparative example and was not recognized in the present invention.

These are a front view and a plan view conceptually showing spiral molding. FIG. 3 is a side view conceptually showing friction stir welding. These are the front view and top view which show arrangement | positioning of the rotation roller (10) for back bead shaping | molding which has the role of a backing material in friction stir welding. These are the longitudinal cross-sectional view of the abutting surface which contact | connects the rotation roller shown in FIG. 3 on the left side, and the cross-sectional view of the abutting surface on the right side. These are the longitudinal cross-sectional view of the abutting surface of flat plates on the left side, and the cross-sectional view of the abutting surface on the right side. These are the conceptual diagrams explaining the principle of a spiral tube. These are figures which show the relationship between (alpha), p, and d. These show w in each case where α is 45 degrees or more, α is 60 degrees or more, and α is 75 degrees or more, and also show the relationship between d, β and p in each of the above cases. These are figures which show the relationship between d and w in the case where α is constant at 75 degrees. These are the conceptual diagrams which show the rolling which shape | molds a convex part at the both ends of a strip | belt material. These are the conceptual diagrams which show the means which pinches | interposes a convex part with a rotation roller so that an abutting surface may not open by insertion of a pin. These are the front view and side view at the time of providing the convex part of the width | variety equal to the diameter of the shoulder of a rotary tool as a prior art in a butt | matching part.

Explanation of symbols

w: The width of the strip (3). α: Cutting angle (inclination angle of butt surface). c: Length of the cut portion (circumferential length of the tube). d: Diameter of the tube. p: Spiral pitch length. β: Supply angle of the strip (3). a (b): Joining length of abutting surfaces per pitch. θ: Pin insertion angle. η: angle of the toe part. 1: Drive roll. 2: Pressure roll. 3: Band material. 4: Spiral shaped product. 5: Pin. 6: Shoulder. 7: Rotary tool. 8: Concave surface of the shoulder (6) surface. 9: Joined material. 10: A rotating roller that also serves as a backing material. 11: Arm for attaching the rotary tool (7). 12 (13): Rolling roll. 14: Convex parts formed on both ends of the strip (3). 15: The remaining part of the convex part shown in FIG. 16: Rotating roller for preventing abutting surfaces from opening. 17: Temporary welding position. Arrow 18: direction of rotation. Arrow 19: the moving direction of the molded body (4) or the joined body. Arrow 20: Joining direction. 21: Guide roller. 22: Stopper for rotation free.

Claims (7)

  Roll forming means (1, 2) for forming the strip (3) into a circular spiral shape so that both side surfaces (a, b) of the strip are abutted, and the abutting location of the molded body (4) A rotary tool (7) comprising a shoulder (6) having a pin (5) on the inner peripheral surface of (a, b) and a concave surface (8) around the pin is provided, and the pin is retracted while rotating the tool. Insert the shoulder part with an angle (θ) until the shoulder part bites into the abutting part, and generate a flash on the outer peripheral surface of the abutting part of the molded body by a rotating roller (10) that also serves as a backing material. And a friction stir welding means for forming a back bead, and a spiral tube of aluminum and an aluminum alloy produced by a continuous process.   Roll forming means (1, 2) for forming the strip (3) into a circular spiral shape so that both side surfaces (a, b) of the strip are abutted, and the abutting location of the molded body (4) A rotary tool (7) comprising a shoulder (6) having a pin (5) on the inner peripheral surface of (a, b) and a concave surface (8) around the pin is provided, and the pin is retracted while rotating the tool. Insert the shoulder part with an angle (θ) until the shoulder part bites into the abutting part, and generate a flash on the outer peripheral surface of the abutting part of the molded body by a rotating roller (10) that also serves as a backing material. A manufacturing method of a spiral tube of aluminum and aluminum alloy, characterized by being manufactured by a continuous process of friction stir welding means for forming a back bead.   A rotating tool (7) comprising a pin (5) and a shoulder (6) having a concave surface (8) around the pin is provided on one surface of the abutting portion of both the workpieces (9), and the tool is rotated. Rotating roller with a receding angle (θ) until the shoulder part bites into the abutting part, and the other side of the abutting part of both materials to be joined serves as a backing material ( 10) A method of friction stir welding of aluminum and aluminum alloy, characterized in that it is joined with means for forming a back bead while producing flash according to 10).   The friction stir welding method according to claim 3, wherein the pin (5) has a tapered spiral shape and is joined while rotating the rotary tool (7) in a direction opposite to the screwing direction of the pin.   The rotary tool (7) is composed of an assembly structure of a pin (5) and a shoulder (6), and has a precision screw structure capable of fine adjustment of the length of the pin. 4. The friction stir welding method according to 4.   The protrusions (14) having a width smaller than the minimum diameter of the pin (5) are provided at the abutting locations of the two materials to be bonded (9) and bonded together. Friction stir welding method.   A rotating tool (7) comprising a pin (5) and a shoulder (6) having a concave surface (8) around the pin is provided on one surface of the abutting portion of both the workpieces (9), and the tool is rotated. Rotating roller with a receding angle (θ) until the shoulder part bites into the abutting part, and the other side of the abutting part of both materials to be joined serves as a backing material ( 10) A structure for friction stir welding of aluminum and an aluminum alloy, characterized in that the structure is joined with means for forming a back bead while producing flash.

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