JP2011083799A - Friction stir welding mechanism and friction stir welding apparatus having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reliably weld base materials to be held by upper and lower shoulders to each other by friction stir welding. <P>SOLUTION: A friction stir welding mechanism includes an upper shoulder 4 which is held in a tool upper 2, a holder 8 which is fixed in a space formed by the upper shoulder 4 by a spring pin 7 through a long hole 6 in a side face of the upper shoulder 4, and fixes a probe 10 integrated with a lower shoulder 9 through a fore end hole 5 in the upper shoulder 4, and a coned disk spring 11 to be interposed between the upper shoulder 4 and the holder 8. Since the pressure P of the upper shoulder 4 to a base material W, the diameter L1 of the upper and lower shoulders 4, 9, the diameter L2 of the probe 10, and a gap L3 between the probe 10 and the fore end hole 5 of the upper shoulder 4 are regulated, the requested friction heat is generated in a requested range irrespective of unevenness of the base materials during the friction stir welding, any breakage of the probe or cohesion of the base materials is prevented, and the base materials can be smoothly and reliably welded to each other. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The invention of the present application includes a friction stir welding mechanism that holds a base material whose end surfaces are butted together by a shoulder from above and below, and performs friction stir welding by a probe along the butted end surfaces of the base materials, and the friction stir welding mechanism. The present invention relates to a friction stir welding apparatus.

  For example, for joining aluminum alloy base materials, end faces of the aluminum alloy materials are brought into contact with each other, and fusion joining or friction stir welding such as MIG welding, TIG welding, flash butt welding, or DC butt welding is generally used. Applicable.

  However, in the case of applying the above-described fusion bonding in joining aluminum alloy materials, MIG welding and TIG welding are excellent in terms of manufacturing cost, but flash butt welding and DC butt welding are very disadvantageous. Further, in terms of quality, since melt bonding tends to cause distortion and blowholes due to heat at the joint, deterioration in appearance and strength becomes a problem.

  On the other hand, in the case of applying friction stir welding, although it is somewhat inferior in terms of manufacturing cost, in terms of quality, since distortion and blowholes due to heat hardly occur in the joint, strength and appearance at the joint are advantageous. Become.

However, the friction stir welding also has the following problems.
That is, in friction stir welding with a fixed pin, a backing jig is required at the time of friction stir welding, the appearance deteriorates due to the trace of the fixed pin when the fixing pin is pulled out, and the kissing bond that causes poor bonding due to insufficient friction stirring There are problems such as generation, distortion in the thickness direction due to the difference in distribution of frictional heat generated during friction stir welding, and an increase in initial investment. Further, in the friction stir welding by the bobbin tool in which the base material is sandwiched by the bobbin from above and below, there are problems such as strict fine adjustment in the plate thickness direction of the probe during friction stir welding and an increase in initial investment.

  In addition, irregularities are likely to occur at the edges of the base materials to be joined. For this reason, the unevenness of the edge of the base material prevents the bobbin from being held with a constant pressure during friction stir welding. As a result, fluctuations in the pressure applied to the base material cannot generate the frictional heat necessary for the base material, and there is a risk of preventing smooth and reliable friction stir welding by the probe.

  For this reason, the first bobbin, the first bobbin, and the first bobbin that clamps the base material from above and below, that is, the first bobbin and the second bobbin, are interposed between the first bobbin and the base member integrated with the probe. There has been proposed a two-bobbin and clamping mechanism that can move in a parallel direction along the central axis (Patent Document 1). However, the first bobbin, the second bobbin, the probe, and the like that can be moved by the springs are the same as the first bobbin that sandwiches the base material even when vertical movement occurs due to the unevenness of the base material to be joined during friction stir welding. Since the two bobbins are interlocked with a spring interposed, the followability to the unevenness of the base material is lacking. That is, the pressure applied by the first bobbin is likely to fluctuate, and the vertical movement of the probe easily takes in a part of the base material to be friction-stirred and tends to cause adhesion of the base material. is there.

JP 2004-114138 A

  The problem to be solved is that when the base material is clamped by the shoulder from the top and bottom direction and friction stir welding is performed with a probe, a constant pressure is always applied regardless of the unevenness of the edge of the base material. It is a point that sufficient frictional heat is generated in such a range that problems such as adhesion of the base material between the probe and the bobbin and breakage of the probe cannot be prevented.

  In the present invention, among the upper and lower shoulders sandwiching the base material, in order to allow the upper shoulder to slide in the vertical direction according to the unevenness at the joint portion, an elastic material is mounted in the upper shoulder, and the mother by the upper shoulder The main characteristics are to define the pressure applied to the material, the shoulder diameter, the probe diameter, and the distance between the probe and the upper shoulder through hole.

As a first feature, a tool upper, an upper shoulder that is slidable vertically in the holding hole of the tool upper, and an upper shoulder in a space formed by the upper shoulder in the holding hole of the tool upper A holder which is fixed by a spring pin through a long hole drilled in the side surface of the body and holds a probe which integrally forms a lower shoulder through a tip hole of the upper shoulder, and an elastic body which is interposed between the upper shoulder and the holder Configured,
The pressure P applied to the upper shoulder base material is P ≧ 0.2 (kN),
The diameter L1 of the upper and lower shoulders is 10 ≦ L1 ≦ 30 (mm),
The diameter L2 of the probe is 4 ≦ L2 ≦ 10 (mm),
The gap L3 between the probe and the tip hole of the upper shoulder is 0.05 ≦ L3 ≦ 0.2 (mm).

  For this reason, even if there are irregularities at the edge of the base material sandwiched between the upper and lower shoulders, the upper shoulders are irregular in the joints due to the elasticity of the elastic body interposed between the upper shoulders and the holder. It follows and quickly slides up and down. As a result, the upper shoulder can keep applying a constant pressure to the base material at all times, so that the friction stir welding by the probe can be reliably performed.

  In addition, since necessary frictional heat can be generated in a necessary range in the base material and the probe can be prevented from being broken and the base material can be prevented from adhering, the friction stir welding of the base material can be performed smoothly.

The pressure applied to the base material by the upper shoulder contributes to the generation of frictional heat for the base material sandwiched between the lower shoulder during friction stir welding. Therefore, if the pressure P applied to the base material is less than 0.2 kN, the upper shoulder cannot generate sufficient frictional heat with respect to the base material during the friction stir welding, and the friction stir welding by the probe cannot be performed reliably. Therefore, it is preferable that the pressure P applied to the base material by the upper shoulder is 0.2 kN or more.
The diameters of the upper and lower shoulders contribute to the range in which the frictional heat required by the friction stir welding is generated in the base material sandwiched therebetween. For this reason, if the diameter L1 of the upper and lower shoulders is less than 4 mm, the range in which frictional heat is generated in the base material during friction stir welding becomes narrow and sufficient friction stir cannot be performed, and if it exceeds 10 mm In this case, the range in which frictional heat is generated becomes excessively large, resulting in a decrease in workability and an increase in work cost. Therefore, it is preferable that the diameter L1 of the upper and lower shoulders is 10 mm or more and 30 mm or less.
Further, an excessive load is applied to the probe because the base material is directly frictionally stirred. Therefore, if the probe diameter L2 is less than 4 mm, the strength against the load applied to the probe at the time of friction stir welding is insufficient and easily breaks, and if it exceeds 10 mm, the friction stir portion in the base material to be joined significantly expands. Therefore, the appearance is deteriorated. Therefore, the probe diameter L2 is preferably 4 mm or more and 10 mm or less.
In addition, a gap is required between the probe and the tip hole of the upper shoulder in order to prevent rotation interference between the probe and the upper shoulder. Therefore, if the gap L3 between the probe and the tip hole of the upper shoulder is less than 0.05 mm, interference between the probe and the tip hole of the upper shoulder is likely to occur due to eccentricity during rotation of the probe, and it exceeds 0.2 mm. A part of the base material overflowing from the base material to be joined may intrude into and adhere to the tip hole of the upper shoulder, preventing smooth rotation of the probe. Therefore, the gap L3 between the probe and the tip hole of the upper shoulder is preferably set to 0.05 mm or more and 0.2 mm or less.

  In the friction stir welding mechanism of the present invention, the upper shoulder slides quickly in the vertical direction according to the irregularities of the base materials to be joined, so that a constant pressure can be constantly applied to the base material. Friction stir by making the upper shoulder pressure P by the elastic body interposed in the shoulder, the upper and lower shoulder diameter L1, the probe diameter L2, and the gap between the probe and the upper shoulder tip hole constant. Since problems that occur during joining can be prevented, friction stir welding using a probe between base materials can be performed smoothly and reliably.

(A) is a fragmentary sectional view which shows the friction stir welding mechanism of this invention, (b) is a side view of an upper shoulder. FIG. 2 is a partial sectional view showing the operation of the friction stir welding mechanism of the present invention.

  An elastic material that is inserted in the upper shoulder for the purpose of securely joining the base material to be joined at the time of friction stir welding with a constant pressing force and also preventing problems during friction stir welding And the upper shoulder pressure P, the upper and lower tool bobbin diameter L1, the probe diameter L2, and the gap L3 between the probe and the upper shoulder tip hole.

  FIG. 1 is a partial sectional view showing a friction stir welding mechanism 1 of the present invention. As an example, the friction stir welding mechanism 1 moves a base material W in the front-rear direction (X-axis direction) (not shown), and moves the friction stir welding mechanism 1 of the present invention in the left-right direction (Y-axis direction). What is provided in a friction stir welding apparatus composed of a movable table (not shown) that freely supports and a gantry (not shown) that supports the movable table so as to be movable in the vertical direction (Z-axis direction). It is.

  The friction stir welding mechanism 1 provided in the friction stir welding apparatus is made of a tool steel material SKD61, and is held in a tool upper 2 having a diameter of 42 mm and slidable in the vertical direction in the holding hole 3 of the tool upper 2. The upper shoulder 4 having a diameter of 26 mm and a long hole 6 which is formed in the side surface of the upper shoulder 4 in the space formed by the upper shoulder 4 in the holding hole 3 of the tool upper 2 and extends in the vertical direction. A holder 8 which is fixed by a spring pin 7 and integrally holds a lower shoulder 9 having a diameter of 26 mm, which is fixed through a tip hole 5 of the upper shoulder 4, and is interposed between the upper shoulder 4 and the holder 8. The disc spring 11 is made of an elastic material.

Then, the pressure P applied to the base material W of the upper shoulder 4 is set to P ≧ 0.2 (kN),
The diameter L1 of the upper and lower shoulders 4 and 9 is 10 ≦ L1 ≦ 30 (mm),
The diameter L2 of the probe 10 is 4 ≦ L2 ≦ 10 (mm),
The gap L3 between the probe 10 and the tip hole 5 of the upper shoulder 4 is 0.05 ≦ L3 ≦ 0.2 (mm).

  As described above, since the friction stir welding mechanism 1 of the present invention is configured, the elastic force of the disc spring 11 interposed between the base material W and the holder 8 in the upper shoulder 4 at the time of friction stir welding. Therefore, the upper and lower shoulders 4 and 9 are sandwiched with a constant pressure P. Therefore, even if the edge of the base material W is uneven, and the thickness of the base material W at that portion is increased from t to t ′, the upper shoulder 4 has a disc spring 11 interposed therein. By compressing, the upper member slides upward following the unevenness of the edge of the base material W, so that a constant pressing force can be continuously applied to the base material W. As a result, the upper and lower shoulders 4 and 9 can generate frictional heat necessary for friction stir welding at the edge of the base material W, and the friction stir welding by the probe 10 can be performed reliably. When the upper shoulder 4 slides upward in the holding hole 3 of the tool upper 2, the long hole 6 of the upper shoulder 4 is the same along the spring pin 7 that unites the tool upper 2 and the holder 8. Slide in the direction. Therefore, the holder 8 itself does not slide upward, and the lower shoulder 9 and the probe 10 remain in place. Even when the thickness of the base material W decreases from t ′ to t, the upper shoulder 4 slides downward, but the holder 8 itself does not slide downward, and the lower shoulder 9 and the probe 10 are also fixed. Will remain in position.

In particular, the pressure P applied to the base material W of the upper shoulder 4 is P ≧ 0.2 (kN),
The diameter L1 of the upper and lower shoulders 4 and 9 is 10 ≦ L1 ≦ 30 (mm),
The diameter L2 of the probe 10 is 4 ≦ L2 ≦ 10 (mm),
The gap L3 between the probe 10 and the tip hole 5 of the upper shoulder 4 is 0.05 ≦ L3 ≦ 0.2 (mm). As a result, the frictional heat necessary for the friction stir welding can be concentrated in the necessary range at the edge of the base material W sandwiched between the upper and lower shoulders 4 and 9 during the friction stir welding. Further, breakage of the probe 10 can be prevented, and a part of the base material W can be prevented from entering and adhering to the gap between the probe 10 and the tip hole 5 of the upper shoulder 4.

  As Example 1, an automotive wheel was manufactured by a friction stir welding apparatus having the friction stir welding mechanism of the present invention. First, the end surfaces of the bent aluminum alloy sheet (5454-O, t4 mm, length 2000 mm) are abutted, and then friction stir welding is performed along the end surfaces by a friction stir welding apparatus including the friction stir welding mechanism. To form a cylindrical shape. And after cut | disconnecting to length 300mm, it was set as the wheel for motor vehicles by the spinning process. Therefore, when a water immersion test and a strength test were performed on the automotive wheel as a product, it was confirmed that the friction stir welding was reliably performed at the joint portion of the automotive wheel and the joint was sufficiently strong. It was done.

  As Example 2, a substation pipeline air was manufactured by a friction stir welding apparatus having the friction stir welding mechanism of the present invention. First, the end surfaces of the bent aluminum alloy plate material (5083-O, t8 mm, length 6000 mm) are butted together, and the friction stir welding is performed along the end surfaces by a friction stir welding apparatus having the friction stir welding mechanism. To form a cylindrical shape. And it was finished bending so that it might become round shape, and it was set as the pipeline air for substations. Therefore, when a penetration flaw test and strength test were performed on the substation pipeline air, it was confirmed that friction stir welding was performed at the junction in the substation pipeline air, and the substation pipeline air was joined with sufficient strength. confirmed.

  Since the friction stir welding can be performed smoothly and surely with a constant applied pressure even when irregularities are formed on the edge of the base material to be joined, it can be applied to the manufacture of any product to which the friction stir welding is applied.

DESCRIPTION OF SYMBOLS 1 Friction stir welding mechanism 2 Tool upper 3 Holding hole 4 Upper shoulder 5 Tip hole 6 Long hole 7 Spring pin 8 Holder 9 Lower shoulder 10 Probe 11 Disc spring 12 Gap W Base material

Claims (2)

A tool upper, an upper shoulder that is slidable vertically in the holding hole of the tool upper, and a side surface of the upper shoulder in a space formed by the upper shoulder in the holding hole of the tool upper It is composed of a holder that is fixed by a spring pin through a long hole and holds a probe that integrally forms a lower shoulder through a tip hole of the upper shoulder, and an elastic body that is interposed between the upper shoulder and the holder,
The pressure P applied to the base material of the upper shoulder is P ≧ 0.2 (kN),
The diameter L1 of the upper and lower shoulders is 10 ≦ L1 ≦ 30 (mm),
The diameter L2 of the probe is 4 ≦ L2 ≦ 10 (mm),
A friction stir welding mechanism characterized in that a gap L3 between the probe and the tip hole of the upper shoulder is 0.05 ≦ L3 ≦ 0.2 (mm).   A friction stir welding apparatus comprising the friction stir welding mechanism according to claim 1.

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