JP2008307606A - Tool for friction stir welding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a friction stir welding tool capable of satisfactorily performing friction stir welding on a weld zone. <P>SOLUTION: The friction stir welding tool 13 includes a shoulder part 13a having a round shoulder face 31 that imparts frictional heat to a workpiece, with a probe 13b provided in a hanging condition along the center axial line of the shoulder face. In the probe, a machining pattern is formed such that, on the upper side of the probe, stirring is performed in the probe circumferential direction parallel to the shoulder face and that, on the lower side of the probe, convection is produced downward. The shoulder face is a face orthogonal to the axial line and, in the shoulder face, there is formed a forced moving pattern of the frictional heat going from the outer circumference to the center relative to the shoulder rotating direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a tool used when performing friction stir welding, and particularly to a tool capable of performing friction stir welding favorably.

  First, the friction stir welding will be described with reference to FIG. For example, the tool 13 is used when joining the two plate materials 11 and 12 by friction stir welding. The tool 13 includes a shoulder portion 13a having a circular shoulder surface that imparts frictional heat to the workpiece, and a probe 13b that is suspended along the central axis of the shoulder surface. When joining the plate materials 11 and 12, the plate materials 11 and 12 are abutted along a joining line (joining line) and clamped on a gantry. Next, the tool 13 is rotated, and the probe 13b is brought into contact with the joining line and press-fitted until the circular shoulder surfaces come into contact with the plate members 11 and 12. The tool 13 is pressed from above and moves along the joining line while rotating. The shoulder portion 13a that rotates while being in contact with the plate members 11 and 12 prevents the softened plate member (material) from popping out, and generates and maintains frictional heat due to relative movement with the plate member. Take on.

  The temperature of the joint portion is equal to or lower than the melting point temperature of the plate material, but the material softened by the frictional heat generated according to the rotational motion of the shoulder portion 13a due to the fluid pressure effect caused by the rotation of the probe 13b and the movement of the shoulder portion 13a. Flowing around the probe, the plate members 11 and 12 are joined at the joint.

  Further, in the friction stir welding method described in Japanese Patent Application Laid-Open No. 2000-233284, as shown in FIG. 6, the center portion of the circular shoulder surface is concave as the shoulder portion (large diameter portion) 202 of the rotary tool 200. The probe 201 of the rotary tool 200 is inserted into the joint and rotated while pressing the joint with the circular shoulder surface to join the molds 100 and 101 (conventional example 1). ).

  On the other hand, as a tool used for friction stir welding, a tool in which the shape of the probe is variously changed is known. For example, in the tool shown in FIG. 7, a spiral screw body 14 is formed on the probe 13b, and the screw body 14 increases the stirring effect of the joint softened by frictional heat (conventional example 2). ).

  Further, in the tool shown in FIG. 8, at least one convex line or groove is provided spirally on the outer periphery of the probe 13b over at least a part of the length in the probe axial direction. That is, in the example shown in FIG. 8, three concave grooves 22 are provided in a spiral shape with a phase difference of 120 ° from the tip of the probe 13b toward the base side (from bottom to top) on the outer periphery of the probe 13b. (Conventional example 3). And in such a state that the probe 13b is inserted into the joint by the spiral concave groove 22, the plastic flow of the material is enhanced by the stirring effect of the probe 13b.

  Moreover, in the tool shown in FIG. 9, the groove | channel 25 extended from the front-end | tip to the center part in the axial direction is formed in the outer periphery of the probe 13b, and these groove | channels 25 are arrange | positioned by shifting the angle relatively ( Conventional Example 4). And the stirring effect of the probe 13b is heightened by these concave grooves 25.

  By the way, since the circular shoulder surface is formed into a flat shape, the stirring effect by the circular shoulder surface is not sufficient. As a result, as shown in FIG. 10, the convection phenomenon is not sufficiently performed, and the friction stir welding is not performed. May be enough. In particular, the rotational speed (circumferential speed) of the circular shoulder surface is higher near the outer periphery than near the central axis, and a convection phenomenon from the outer periphery toward the central axis is unlikely to occur.

  On the other hand, when the shoulder portion having a concave center portion of the circular shoulder surface is used as in Conventional Example 1, almost no frictional heat is generated near the center portion, and the joint portion is satisfactorily friction stir welded. It is difficult.

  Further, in the conventional example 2, although the spiral screw body 14 is provided, the material is merely plastically flowed from the upper side to the lower side in the figure, and it is difficult to convect the material. In addition, the friction stir welding may not be performed satisfactorily. Moreover, even in the conventional example 2, since the circular shoulder surface of the shoulder portion 13a is formed into a flat shape, the convection phenomenon hardly occurs.

  In Conventional Example 3, since the spiral concave groove 22 is only formed in a part (lower side) of the probe 13b, the stirring effect on the upper side of the probe 13b is not sufficient. And also in the prior art 3, since the circular shoulder surface of the shoulder part 13a is shape | molded by planar shape, a convection phenomenon will not occur easily.

  In Conventional Example 4, although the concave groove 25 is formed on the outer periphery of the probe 13b, the stirring effect on the upper side of the probe 13b is not sufficient, and also in Conventional Example 4, the circular shoulder surface of the shoulder portion 13a is planar. Therefore, the convection phenomenon is unlikely to occur.

  As described above, in the conventional tool, the convection effect in the shoulder portion 13a is not sufficiently performed, and further, the stirring effect by the probe 13b is not sufficient, so that the joint portion may not be satisfactorily friction stir welded.

  An object of the present invention is to provide a friction stir welding tool that can satisfactorily friction stir weld a joint.

  In the present invention, in a tool for performing friction stir welding in which a probe is suspended along a central axis of a shoulder portion and a shoulder surface having a circular shoulder surface that imparts frictional heat to a workpiece, the probe is a probe On the upper side, there is provided a friction stir welding tool characterized in that a processing pattern is formed so as to stir in the probe circumferential direction parallel to the shoulder surface and to generate convection downward on the lower side of the probe. can get.

  According to this invention, the probe is formed with a processing pattern that stirs in the probe circumferential direction parallel to the shoulder surface on the upper side of the probe and causes convection downward on the lower side of the probe. Stirring and convection can be performed sufficiently, and as a result, good friction stir welding can be performed. For example, the processing pattern on the upper side of the probe is a vertical or mesh pattern, and the processing pattern on the lower side of the probe is a spiral or screw pattern that causes a rotational flow to be generated downward with respect to the probe rotation direction.

  According to the present invention, in the tool for performing the friction stir welding in which the probe is suspended along the central axis of the shoulder portion and the shoulder portion having a circular shoulder surface for applying frictional heat to the workpiece, The shoulder surface is a surface orthogonal to the axis, a frictional heat forced movement pattern is formed on the shoulder surface from the outer peripheral side to the center side with respect to the shoulder rotation direction, and the probe is parallel to the shoulder surface on the probe upper side. A friction stir welding tool is obtained in which a working pattern is formed so as to stir the probe in the circumferential direction and generate convection downward on the probe lower side.

  According to this invention, since the frictional heat forced movement pattern is formed on the shoulder surface from the outer peripheral side toward the central side with respect to the shoulder rotation direction, the frictional heat caused by the rotational movement of the shoulder portion is transferred to the outside of the joint portion. Can be forced to move from the center to the center, and as a result, the convection phenomenon is sufficient. And if it does in this way, the plastic flow in a junction part will be raised. Furthermore, the probe has a processing pattern that agitates in the probe circumferential direction parallel to the shoulder surface on the upper side of the probe and generates convection downward on the lower side of the probe. As a result, satisfactory friction stir welding can be performed.

  According to this invention, since the frictional heat forced movement pattern is formed on the shoulder surface from the outer peripheral side toward the central side with respect to the shoulder rotation direction, the frictional heat caused by the rotational movement of the shoulder portion is transferred to the outside of the joint portion. Can be forcibly moved from the center to the center, so that the convection phenomenon is sufficient. And if it does in this way, the plastic flow in a junction part will be raised and friction stir welding can be performed satisfactorily.

  In the present invention, the frictional heat forced movement pattern is, for example, a continuous convex or concave curve formed of a scroll, a spiral pattern, or a radial curve line from the outside toward the center with respect to the shoulder rotation direction.

  As described above, if the frictional heat forced movement pattern is a continuous convex or concave curve consisting of a scroll or spiral pattern or a radial curve line from the outside to the center side with respect to the shoulder rotation direction, the heat generation amount on the outside and the heat generation on the center side. The amount can be different, so that the convection phenomenon is sufficient.

  In the present invention, the frictional heat forced movement pattern is, for example, a scattered point pattern in which the density difference or the diameter ratio is varied from the outer peripheral side toward the central side. Even in this case, the heat generation amount on the outer side and the heat generation amount on the center side can be made different.

  As described above, according to the present invention, the probe is agitated in the probe circumferential direction parallel to the shoulder surface on the upper side of the probe, and the processing pattern is generated so as to generate convection downward on the lower side of the probe. Since they are formed, the material can be sufficiently stirred and convected, and as a result, there is an effect that good friction stir welding can be performed. If the machining pattern on the upper side of the probe is a vertical or mesh pattern, and the machining pattern on the lower side of the probe is a spiral or screw pattern that generates a downward flow with respect to the probe rotation direction, the machining pattern can be easily formed on the probe. can do.

  In the present invention, a forced frictional movement pattern is formed on the shoulder surface from the outer peripheral side to the center side in the shoulder rotation direction, and the probe is agitated in the probe circumferential direction parallel to the shoulder surface on the probe upper side. Since the processing pattern that causes convection toward the lower side on the lower side is formed, the frictional heat caused by the rotational movement of the shoulder portion can be forcibly moved from the outside of the joint portion to the center side, As a result, not only can the convection phenomenon be sufficiently generated, but also the material can be sufficiently stirred and convectioned by the probe, and as a result, a good friction stir welding can be performed. is there.

  In the present invention, since the frictional heat forced movement pattern from the outer peripheral side toward the central side with respect to the shoulder rotation direction is formed on the shoulder surface, the frictional heat caused by the rotational movement of the shoulder portion is abutted against the outside of the joint portion. Can be forcibly moved to the center side. As a result, the convection phenomenon becomes sufficient, the plastic flow at the butt joint is increased, and there is an effect that the friction stir welding can be performed satisfactorily.

  In the present invention, the frictional heat forced movement pattern is a continuous convex or concave curve consisting of a scroll or spiral pattern or a radial curve line from the outside to the center side with respect to the shoulder rotation direction. It can be formed on the shoulder surface, and the heat generation amount on the outer side and the heat generation amount on the center side can be made different, so that the convection phenomenon can be sufficiently generated.

  In the present invention, since the scattered point pattern in which the density difference or the diameter ratio is different from the outer peripheral side toward the central side is used as the frictional heat forced movement pattern, the calorific value on the outer side and the calorific value on the central side are calculated. The convection phenomenon can be sufficiently generated.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.

  Hereinafter, embodiments of the present invention will be exemplarily described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. This is just an example.

  FIG. 1 is a view showing a circular shoulder surface 31 defined in the shoulder portion 13 a of the friction stir welding tool 13. The circular shoulder surface 31 is a surface orthogonal to the axis of the tool 13, and the circular shoulder surface 31 has a friction from the outer peripheral side of the circular shoulder surface 31 toward the center side in the shoulder rotation direction (direction indicated by the solid line arrow). A heat forced movement pattern 32 is formed.

  For example, in the example shown in FIG. 1A, the circular shoulder surface 31 has a frictional heat forced movement pattern 32 from the outer side (outer periphery) to the central side (center side) of the circular shoulder surface 31 with respect to the shoulder rotation direction. A scroll-like continuous curve is formed toward the head, and this scroll-like continuous curve is a convex or concave curve.

  When the friction stir welding is performed as shown in FIG. 5 using the tool 13 having the circular shoulder surface 31 as the frictional heat forced movement pattern 32, the scroll-like convex or concave curve shown in FIG. Or, since the concave curve is a scroll-like continuous curve from the outer side of the circular shoulder surface 31 toward the center side with respect to the shoulder rotation direction, the circular shoulder surface 31 is joined at the junction (see FIG. The pressing force for pressing the plate members 11 and 12) shown in FIG. 2 is different, and the area where the circular shoulder surface 31 is in contact with the joint is greatly different between the vicinity of the center and the vicinity of the outside. There will be a difference in frictional heat between the area and the vicinity. Then, convection from the outside to the inside occurs. Since the friction effect is improved by forming the scroll-like convex or concave curve, the convection phenomenon is sufficiently and satisfactorily performed as shown in FIG.

  As a result, the plate material that has flowed plastically is sufficiently stirred at the joint, and the friction stir welding can be performed satisfactorily.

  In the example shown in FIG. 1B, the circular shoulder surface 31 has a frictional heat forced movement pattern 32 from the outer side (outer periphery) of the circular shoulder surface 31 to the center side (center side) with respect to the shoulder rotation direction. A spiral continuous curve is formed, and this spiral continuous curve is a convex or concave curve.

  When the friction stir welding is performed as shown in FIG. 5 using the tool 13 having the circular shoulder surface 31 as the frictional heat forced movement pattern 32, the spiral convexity or concave curve shown in FIG. Alternatively, since the concave curve is a spiral continuous curve from the outer side of the circular shoulder surface 31 toward the center side with respect to the shoulder rotation direction, the circular shoulder surface 31 presses the joint portion near the center and near the outer side. The pressure is different, and the area where the circular shoulder surface 31 is in contact with the joint is greatly different between the vicinity of the center and the vicinity of the outside, and a difference in frictional heat occurs between the outside (outer periphery) of the joint and the vicinity of the center. It will be. Then, convection from the outside to the inside occurs. Since the friction effect is improved by forming the spiral convex or concave curve, the convection phenomenon is sufficiently and satisfactorily performed.

  In the example shown in FIG. 1C, the circular shoulder surface 31 has a frictional heat forced movement pattern 32 from the outer side (outer periphery) of the circular shoulder surface 31 toward the center side (center side) with respect to the shoulder rotation direction. A radial curved continuous curve is formed, and this radial curved continuous curve is a convex or concave curve.

  When the friction stir welding is performed as shown in FIG. 5 using the tool 13 having the circular shoulder surface 31 as the frictional heat forced movement pattern 32 having the radial curved convex or concave curve shown in FIG. This convex or concave curve is a continuous curve of a radial curve from the outer side of the circular shoulder surface 31 toward the center side with respect to the shoulder rotation direction, so that the circular shoulder surface 31 has a joint portion near the center and near the outer side. The pressing force to be pressed is different, and the area where the circular shoulder surface 31 is in contact with the joint portion is greatly different between the vicinity of the center and the vicinity of the outer portion, and frictional heat is generated between the outer portion (outer periphery) of the joint portion and the vicinity of the center portion. There will be a difference. Then, convection from the outside to the inside occurs. Since the frictional effect is improved by forming the radial curved convex or concave curve, the convection phenomenon is sufficiently and satisfactorily performed.

  Further, as shown in FIG. 1 (d), as the frictional heat forced movement pattern 32 on the circular shoulder surface 31, the density difference or the diameter ratio from the outer side (outer periphery) to the central side (center side) of the circular shoulder surface 31. Alternatively, the scattered point pattern 33 may be formed. Each scattered point 33a of the scattered point pattern 33 is, for example, convex or concave.

  Each scattered point 33a is circular, for example, and when each scattered point 33a is concave, the diameter of the scattered point 33a is small on the center side, and the diameter increases toward the outside. Then, it is desirable to arrange the scattered points 33a in a spiral shape, for example.

  When the friction stir welding is performed as shown in FIG. 5 using the tool 13 having the circular shoulder surface 31 on which such a scattered point pattern 33 is formed, the concave scattered point pattern 33 has an outer side from the center side. Since the diameter increases toward the center, the pressing force with which the circular shoulder surface 31 presses the joint is different between the vicinity of the center and the vicinity of the outside, and the area where the circular shoulder surface 31 contacts the joint is near the center. Therefore, there is a difference in frictional heat between the outside (outer periphery) of the joint and the vicinity of the center. Then, convection from the outside to the inside occurs. Since the frictional effect is improved by forming the radial curved convex or concave curve, the convection phenomenon is sufficiently and satisfactorily performed.

  As described above, instead of making the diameter ratio of the concave scattered points 33a located on the outer side and the concave scattered points 33a located on the center side different, the density difference may be made different. That is, the concave scattered points 33a may be reduced on the center side of the circular shoulder surface 31, and the concave scattered points 33a may be increased as going outward. Even in this case, the pressing force with which the circular shoulder surface 31 presses the joint portion is different, and the area where the circular shoulder surface 31 is in contact with the joint portion is greatly different between the vicinity of the center and the vicinity of the outer portion. There will be a difference in frictional heat between the outside (outer periphery) and the vicinity of the center.

  Further, when each scattered point 33a is convex, the diameter of the scattered point 33a is increased on the center side, and the diameter is decreased toward the outside. Further, the convex scattered points 33a may be increased on the center side of the circular shoulder surface 31, and the convex scattered points 33a may be decreased toward the outside.

  Note that the shape of each scattered point 33a is not limited to a circle, and may be a polygon, for example. In any case, the contact area between the center side and the outer side (outer peripheral side) of the circular shoulder surface 31 What is necessary is to make it different.

  Referring to FIG. 3, a machining pattern 41 is formed on the outer peripheral surface of the probe 13b of the tool 13. The machining pattern 41 includes an upper machining pattern 41a positioned on the upper side of the probe 13b in the drawing, and a probe. And a lower processing pattern 41b positioned on the lower side of 13b. Then, stirring is performed in the probe circumferential direction parallel to the circular shoulder surface 13a by the upper processing pattern 41a, and convection is generated toward the lower side in the figure by the lower processing pattern 41b.

  As shown in FIG. 3, a mesh pattern (knurled mesh pattern) is used as the upper processing pattern 41a, and a screw pattern is used as the lower processing pattern 41b. When the friction stir welding is performed as shown in FIG. 5 using the tool 13 having the probe 13b on which such a processed pattern 41 is formed, the joint portions of the plate members 11 and 12 are circular shoulder surfaces due to the mesh pattern. It will be stirred in the probe circumferential direction parallel to 13a. On the other hand, convection is generated downward by the screw pattern. As a result, as shown in FIG. 3, convection occurs from the upper side to the lower side in the vicinity of the probe due to the stirring action of the probe 13a, and convection from the lower side to the upper side occurs in the vicinity of the probe and is joined by the probe 13b. The part will be sufficiently stirred. As a result, the plastically flowed plate material is sufficiently agitated in the joint portion, and the friction stir welding can be performed satisfactorily.

  As shown in FIG. 4, the upper processing pattern 41a may be a vertical pattern (knurl pattern), and the lower processing pattern 41b may be a spiral pattern. Even in this case, the convection occurs from the upper side to the lower side in the vicinity of the probe due to the stirring action of the probe 13a, and the convection from the lower side to the upper side occurs in the vicinity of the probe. It will be stirred.

  In this way, if the processing pattern that causes stirring in the probe circumferential direction parallel to the circular shoulder surface on the upper side of the probe and causes convection downward on the lower side of the probe is formed on the outer peripheral surface of the probe, Can be sufficiently stirred.

  If the tool 13 is formed with the above-described friction forced movement pattern 32 formed on the circular shoulder surface 13a and the above-described machining pattern 41 formed on the outer peripheral surface of the probe 13b, both the convection effect and the stirring effect are improved. Thus, the friction stir welding can be performed more satisfactorily.

According to the present invention, it is possible to provide a friction stir welding tool that can satisfactorily friction stir weld the joint.

It is a figure which shows the example of the frictional heat forced movement pattern formed in the tool by this invention, (a) is a figure which shows a 1st example, (b) is a figure which shows a 2nd example, (c) is a 3rd (D) is a figure which shows the example of 4th. It is a figure which shows the convection phenomenon at the time of using the tool shown in FIG. It is a figure which shows an example of the process pattern formed in the probe with which the tool by this invention was equipped. It is a figure which shows the other example of the process pattern formed in the probe with which the tool by this invention was equipped. It is a figure for demonstrating friction stir welding. It is sectional drawing for demonstrating an example of the conventional tool. It is sectional drawing for demonstrating the other example of the conventional tool. It is sectional drawing for demonstrating the other example of the conventional tool. It is sectional drawing for demonstrating the other example of the conventional tool. It is a figure which shows the convection phenomenon when the shoulder surface of a tool is a plane.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11, 12 Board | plate material 13 Tool 13a Shoulder part 13b Probe 31 Circular shoulder surface 32 Frictional heat forced movement pattern 33 Scattered point pattern 41 Processing pattern 41a Upper side processing pattern 41b Lower side processing pattern

Claims (3)

In a tool for performing friction stir welding in which a probe is suspended along a center axis of a shoulder portion having a circular shoulder surface that imparts frictional heat to a work piece and a shoulder surface,
The probe is agitated in the probe circumferential direction parallel to the shoulder surface on the upper side of the probe on the shoulder surface side, and a processing pattern is formed so as to generate convection downward on the lower side of the probe on the anti-shoulder surface side. A friction stir welding tool characterized by comprising:   The probe has a processing pattern on the shoulder surface side above the probe that is a vertical or mesh pattern, and a processing pattern on the anti-shoulder surface side that is on the lower side of the probe is a spiral or screw pattern that causes a downward flow with respect to the probe rotation direction. The friction stir welding tool according to claim 1, wherein the friction stir welding tool is provided. In a tool for performing friction stir welding in which a probe is suspended along a central axis of a shoulder portion and a shoulder surface provided with a circular shoulder surface that imparts frictional heat to a workpiece,
The shoulder surface is a surface orthogonal to the axis, and a frictional heat forced movement pattern is formed on the shoulder surface from the outer peripheral side to the center side with respect to the shoulder rotation direction.
In addition, a processing pattern is formed so that the probe is agitated in the probe circumferential direction parallel to the shoulder surface on the upper side of the probe on the shoulder surface side, and convection is generated on the lower side of the probe on the opposite shoulder surface side. A friction stir welding tool characterized by being made.

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