JP2005305486A - Friction stir welding jig - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a friction stir welding jig equipped with a rotor which can securely prevent the splash of a molten workpiece and the growth of burrs protruding from the joined surface of the workpiece. <P>SOLUTION: A friction stir welding jig 1 equipped with the cylindrical rotor 2 having a joining pin 4 on its end and also with a fluidity inhibiting member 7 covering the outer circumferential face of the rotor 2. The fluidity inhibiting member 7 is supported in a state that the fluidity inhibiting member 7 does not rotate against members W1 and W2 to be joined. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a friction stir welding jig, and more particularly, to a friction stir welding jig capable of preventing the scattering of molten work and the generation of burrs on the work.

  In recent years, friction stir welding has attracted attention as a method for joining members to be joined (hereinafter referred to as workpieces) made of metal materials such as aluminum, magnesium, iron, and resin materials, and various friction stir welding jigs have been developed. ing. This friction stir welding method is characterized in that the distortion of the workpiece after joining is smaller than that of a conventional joining method such as arc welding, and a joining strength higher than the joining strength in arc welding can be obtained.

  As shown in FIG. 5, this friction stir welding jig is usually provided with a cylindrical rotor 100 having a projection called a joining pin 101 at the tip. Then, while rotating the rotor 100 at a high speed, the joining pin 101 is pressed against the joining point P of the pair of workpieces W1 and W2 in the overlapped state where the backing material M is applied from the back side or the end portions are butted together. [See FIG. 5A] When the vicinity of the joint is softened by frictional heat, the joint pin 101 is further press-fitted [see FIG. 5B], and the shoulder portion 102 of the rotor 100 that supports the joint pin 101 and the joint pin. The vicinity of the joining point of the workpieces W1 and W2 softened in step 1 is agitated to cause plastic flow, and the workpieces are metallurgically integrated [see FIG. 5C].

  However, since the shoulder portion 102 of the rotor 100 rubs against the workpiece by high speed rotation, a part of the melted workpiece is scattered, or a burr B protruding in an arc shape is generated at a portion corresponding to the edge of the shoulder portion of the workpiece surface. (See FIG. 6). Such burrs are not preferable from the viewpoint of the appearance and quality of the product and need to be removed. However, since removal work is added to the work process, the number of processes is increased, and it takes time and effort, leading to an increase in product cost.

  In addition, the amount of work in the joint portion is reduced by the amount of burrs or scattering, and there are cases where the joint strength is lowered due to the formation of voids in the work in the joint portion.

Therefore, as a jig for preventing such burr generation and scattering, a ring-shaped convex portion is formed at the edge of the shoulder portion of the rotor, and the shoulder portion between the ring-shaped convex portion and the joining pin There has been proposed a rotor provided with a reservoir for storing a melted workpiece (see Patent Document 1). Further, there has been proposed a rotor in which protrusions for cutting burrs are provided outwardly at the edge of the shoulder portion of the rotor, and the generated burrs are removed by the protrusions that rotate as the rotor rotates ( Patent Document 2).
JP 2002-224859 A JP 2002-66760 A

  However, when the friction stir welding is actually performed using the rotor described in Patent Document 1, the melted workpiece does not collect in the pool part or overflows from the pool part, and scatters or burrs are generated. Occasionally, it cannot be said that burr generation and scattering can be reliably prevented.

  Moreover, in the rotor of patent document 2, unless the attachment position and attachment angle with respect to the rotor of the cutting protrusion rotating with the rotor or the pressing of the rotor against the workpiece are not properly adjusted, the cutting protrusion There is a problem that the burrs cannot be removed accurately, or the cutting projection hits the workpiece, and new burrs are generated or the workpiece is scattered.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a friction stir welding jig including a rotor that can reliably prevent the melted workpiece from scattering and the occurrence of burrs protruding on the workpiece joining surface.

  In order to solve the above problem, the friction stir welding jig according to claim 1 is a friction stir welding jig provided with a cylindrical rotor having a joining pin at a tip, and the outer peripheral surface of the rotor is annularly formed. A flow suppressing member is provided, and the flow suppressing member is supported in a state in which the flow suppressing member does not rotate with respect to the bonded member.

  According to the first aspect of the present invention, the joining pin is press-fitted into the member to be joined (that is, the workpiece) softened by frictional heat, and the shoulder portion at the tip of the rotor contacts the workpiece to heat the workpiece by frictional heat. In such a state, the flow suppressing member that annularly covers the outer peripheral surface of the rotor contacts the workpiece without rotating with respect to the workpiece.

  According to a second aspect of the present invention, in the friction stir welding jig according to the first aspect, an annular elastic body is provided on the rear end side of the flow suppressing member.

  According to invention of Claim 2, when the said flow suppression member contacts with a workpiece | work in the state which does not rotate with respect to a workpiece | work, with the elastic force of the elastic body provided in the rear-end side of the flow suppression member, The flow suppressing member is pressed against the workpiece.

  According to a third aspect of the present invention, in the friction stir welding jig according to the second aspect, the rear end side of the elastic body is fixed to an annular mounting member surrounding the rotor.

  According to the third aspect of the present invention, by fixing the mounting member to the friction stir welding apparatus main body, the flow suppressing member can be fixed to the mounting member via the elastic body, and the flow suppressing member is dragged by the rotation of the rotor. And is prevented from rotating.

  According to a fourth aspect of the present invention, in the friction stir welding tool according to any one of the first to third aspects, a lubricant is filled in a gap between the flow suppressing member and the rotor. It is characterized by that.

  According to the invention described in claim 4, since the lubricant is filled between the flow suppressing member and the rotor, the high-speed rotation of the rotor becomes smooth, and the rotation of the rotor makes the flow suppressing member The applied rotational moment is further reduced.

  According to the first aspect of the present invention, the joining pin at the rotor tip of the friction stir welding jig is press-fitted into the member to be joined (that is, the workpiece) softened by frictional heat, and the shoulder portion at the tip of the rotor is inserted into the workpiece. In the state where the workpiece is heated by frictional heat, the flow suppressing member that annularly covers the outer peripheral surface of the rotor contacts the workpiece without rotating with respect to the workpiece, so that the rotor is softened and melted by the high-speed rotation of the rotor. The outflow of the workpiece to the outside of the rotor is effectively prevented by the flow suppressing member in contact with the workpiece. Further, since the flow suppressing member itself does not rotate with respect to the workpiece, it is possible to avoid the melting of the molten workpiece and the occurrence of burrs due to the rotation of the flow suppressing member.

  In this way, it is possible to reliably prevent the workpiece from being scattered and burr generated during friction stir welding, and at the same time, it is not necessary to remove the burr in the joining work, saving labor and melting at the work joint. Therefore, it is possible to effectively avoid a situation in which a gap is generated in the joining portion or the joining strength is reduced.

  According to invention of Claim 2, when the said flow suppression member contacts with a workpiece | work in the state which does not rotate with respect to a workpiece | work, with the elastic force of the elastic body provided in the rear-end side of the flow suppression member, Since the flow suppressing member is pressed against the work, in addition to the effect of the invention described in claim 1, the flow suppressing member more effectively exhibits the effect of preventing the softened and melted work from flowing out to the outside of the rotor. It becomes possible to make it.

  According to the third aspect of the present invention, since the flow suppressing member can be fixed to the mounting member via the elastic body by fixing the mounting member to the friction stir welding apparatus main body, the flow suppressing member can rotate the rotor. The rotation by being dragged is effectively prevented, and the effects of the invention described in the claims can be more reliably exhibited.

  According to the invention described in claim 4, since the lubricant is filled between the flow suppressing member and the rotor, the high-speed rotation of the rotor becomes smooth, and the rotation of the rotor makes the flow suppressing member The applied moment of rotation is further reduced. For this reason, the effects of the invention described in the above claims are more effectively exhibited, and the excessive rotational moment applied to the rotor and the flow suppressing member, as well as the elastic body and the mounting member is reduced, and each member is consumed. Alleviated. Moreover, useless power consumption can be avoided.

  Hereinafter, embodiments of a friction stir welding tool according to the present invention will be described with reference to the drawings.

  FIG. 1A is a perspective view of the friction stir welding jig of the present embodiment, and FIG. 1B is a cross-sectional view of the friction stir welding jig of FIG. 1A taken along the line XX. The friction stir welding jig 1 includes a cylindrical rotor 2. The rotor 2 is configured to be rotated at high speed about the axis L by a friction stir welding apparatus body (not shown) on the rear end side. In the present embodiment, the outer peripheral surface 3 of the rotor 2 is subjected to surface treatment so as to reduce the friction coefficient.

  A cylindrical joining pin 4 having a chamfered tip corner is provided integrally with the rotor 2 so as to be coaxial with the rotor 2 at the center of the tip surface of the rotor 2. The length or the like of the joining pin 4 is appropriately selected depending on the thickness of a workpiece (not shown) to be joined.

  A shoulder that is inclined so as to enter the inside of the rotor as it goes from the outer peripheral edge to the center joining pin 4, that is, away from the opposing workpiece, at the outer peripheral portion of the joining pin 4 at the front end surface of the rotor 2. A portion 5 is provided, and the shoulder portion 5 is adapted to receive a work melted by frictional heat. Therefore, the degree of inclination of the shoulder portion 5, that is, the volume of the molten workpiece pool portion 6 formed by the outer periphery of the joining pin 4 and the shoulder portion 5 can accommodate all the molten workpiece pushed out by the joining pin 4. Is determined as appropriate.

  On the outer peripheral side of the rotor 2, a cylindrical flow suppressing member 7 is provided so as to cover the outer peripheral surface 3 in a ring shape. In the present embodiment, the inner surface 8 of the flow suppressing member 7 is subjected to a surface treatment so as to reduce the friction coefficient, like the outer peripheral surface 3 of the rotor 2. Further, the gap between the rotor 2 and the flow suppressing member 7 is filled with a lubricant 9, and oils, solid lubricants, and the like are used as the lubricant 9. The gap between the rotor 2 and the flow suppressing member 7 is appropriately set within a range of about 0.5 mm or less.

  On the rear end side of the flow suppressing member 7, a cylindrical elastic body 10 made of a spring, a rubber material, or the like covers the outer peripheral surface 3 of the rotor 2 in a ring shape through the lubricant 9 like the flow suppressing member 7. The flow suppressing member 7 and the elastic body 10 are fixed. The elastic body 10 is for pressing the flow suppressing member 7 against a workpiece (not shown). The elastic modulus is the length of the joining pin 4, the thickness of the workpiece, the material, the strength, the joining pressure, and the joining. It is appropriately determined in consideration of factors such as time and the number of rotations of the rotor 2.

  The rear end side of the elastic body 10 is fixed to an annular mounting member 11 so as to surround the rotor 2, and the mounting member 11 is fixed to a friction stir welding apparatus main body (not shown). That is, in this embodiment, the flow suppressing member 7 and the elastic body 10 are supported so as not to rotate with respect to a workpiece (not shown) by being fixed to the friction stir welding apparatus main body via the mounting member 11.

  Thus, since the flow suppression member 7, the elastic body 10, and the attachment member 11 are in a state of sliding with respect to the rotor 2 that rotates at high speed, heat is generated by friction with the rotor 2. Therefore, it is desirable that heat treatment including the lubricant 9 is performed.

  Next, the operation of the friction stir welding jig 1 of this embodiment will be described.

  FIG. 2 is a cross-sectional view showing a state in which workpieces overlapped using the friction stir welding jig of the present embodiment are spot welded, and shows a state in which the joining pins 4 are press-fitted into the overlapped workpieces W1 and W2. The procedure for joining the workpieces W1 and W2 using the friction stir welding jig 1 is the same as the procedure shown in FIGS. 5A to 5C described above, and FIG. Corresponding to

  In the state of FIG. 2, the rotor 2 rotates at high speed about the axis L [see FIG. 1B], and the workpiece W 1 and the workpiece W 2 in the vicinity of the joint pin 4 and the shoulder portion 5 are joined to the joint pin 4. Heated by friction with the shoulder portion 5 and softened / melted, and further stirred by the joining pin 4 and the shoulder portion 5 to produce a plastic flow and to be integrated.

  On the other hand, the flow suppressing member 7 is fixed to an attachment member 11 attached to the friction stir welding apparatus main body via an elastic body 10, and does not rotate with respect to the workpiece and is stationary. Further, the rotor 2 is in a state of being slightly pushed in from the surface of the workpiece W1 in order to generate frictional heat, but the flow suppressing member 7 is pressed against the surface of the workpiece W1 by the elastic force of the elastic body 10. It will be in the state.

  The work softened and melted by the frictional heat is pressed from the joining pin 4 and the shoulder portion 5 but is not formed to flow downward in the figure by the backing material M applied from the back side, and is formed in the shoulder portion 5. It enters the accumulation part 6. Further, a part of the melted work tends to flow from the edge of the shoulder portion 5 to the outside of the rotor 2. However, as described above, since the flow suppressing member 7 is pressed against the work by the elastic body 10 on the outside of the rotor 2, it cannot flow beyond that to the outside of the friction stir welding jig 1, Stays at the workpiece joint.

  As described above, according to the friction stir welding jig 1 of the present embodiment, the outflow of the work softened and melted by the high speed rotation of the rotor 2 to the outside of the rotor is pressed against the work by the elastic force of the elastic body 10. The flow restricting member 7 is effectively prevented. Therefore, it is possible to reliably prevent the workpiece from being scattered and burrs from being generated during friction stir welding.

  Further, at this time, since the flow suppressing member itself does not rotate with respect to the work, it is possible to avoid a situation in which the melted work is scattered by the rotation of the flow suppressing member 7 or a new burr is generated on the work.

  Further, since the generation of burrs is surely prevented by the flow suppressing member 7, it is not necessary to remove the burrs in the joining operation, and labor can be saved, and the molten work remains at the joined portion of the workpiece. It is possible to effectively avoid the occurrence of voids or a decrease in bonding strength.

  In the present embodiment, the case where the overlapped workpieces are spot welded by the friction stir welding jig 1 has been described. However, as shown in FIG. The same can be explained.

  Further, for example, as shown in FIG. 4, the friction stir welding jig 1 in a state where the rotor 2 is rotated at a high speed and the joining pin 4 is press-fitted into the abutting surface F of the workpieces W1 and W2 in a state where the ends are abutted. It is also possible to continuously join the pair of workpieces W1 and W2 by moving along the butting surface F. In this case, the joining pin 4 and the shoulder portion 5 melt the work ahead in the moving direction with frictional heat, and send it backward while stirring. At that time, similarly to the above, the flow suppression member 7 pressed against the workpieces W1 and W2 by the elastic force of the elastic body 10 effectively prevents the molten workpiece from flowing out. It is possible to reliably prevent the occurrence of burrs. The same applies when a pair of stacked workpieces are continuously joined.

  Furthermore, in this embodiment, when the elastic body 10 is provided on the rear end side of the flow suppressing member 7, the rear end is further attached to the attachment member 11, and the flow suppressing member 7 is pressed against the work by the elastic force of the elastic body 10. At the same time, the rotor 2 did not rotate with respect to the workpiece without being dragged by the rotation of the rotor 2. However, this can be realized by other methods and means. For example, instead of providing the annular elastic body 10 on the rear end side of the flow suppressing member 7, the outer peripheral surface of the flow suppressing member 7 and the attachment member 11 or the friction stir welding apparatus main body are prevented from rotating. The above state can also be realized by connecting with an elastic body such as a spring.

(A) is a perspective view of the friction stir welding jig of the present embodiment, and (B) is a cross-sectional view taken along line XX of the friction stir welding jig of (A). It is sectional drawing which shows the state which carries out the spot welding of the workpiece | work piled up using the friction stir welding jig of this embodiment. It is sectional drawing which shows the state which carries out the spot welding of the workpiece | work which faced | matched the edge part using the friction stir welding jig of this embodiment. It is a perspective view which shows the state which continuously joins the workpiece | work which faced | matched the edge part using the friction stir welding jig of this embodiment. It is a figure which shows the state which joins the workpiece | work piled up using the conventional friction stir welding jig. It is a figure explaining the burr | flash which protruded on the workpiece | work surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Friction stir welding tool 2 Rotor 4 Joining pin 7 Flow suppression member 9 Lubricant 10 Elastic body 11 Attachment member W1, W2 Joined member (workpiece)

Claims (4)

A friction stir welding tool provided with a cylindrical rotor having a joining pin at the tip,
A friction stir welding jig comprising a flow suppressing member that annularly covers an outer peripheral surface of the rotor, and the flow suppressing member is supported in a state of not rotating with respect to a member to be bonded.   The friction stir welding jig according to claim 1, wherein an annular elastic body is provided on the rear end side of the flow suppressing member.   The friction stir welding jig according to claim 2, wherein a rear end side of the elastic body is fixed to an annular mounting member surrounding the rotor.   The friction stir welding jig according to any one of claims 1 to 3, wherein a lubricant is filled in a gap between the flow suppressing member and the rotor.

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