JP2003071574A - Friction stir welding method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To join thin metal plates by friction stir welding favorable of the thin metal plate. SOLUTION: A non-consumable pin 14 for a probe 16 is eccentrically mounted against the probe 16 to revolve the non-consumable pin 14 against the axial line 16x of the probe 16, and while the lower half part of the non-consumable pin 14 is subjected to diametric expansion in a taper state to generate large frictional heat in the thin material to be welded as well, welding is carried out by stirring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a friction stir welding method and apparatus that can be used for joining thin sheet metals required for manufacturing a heat sink, for example.

[0002]

2. Description of the Related Art In recent years, high-density packaging products have been used in the fields of computers, communications, automobiles, etc. In order to dissipate heat from the high-density packaging products, such as heat pipes and radiation fins. A heat sink is used to dissipate the heat. For this heat sink, a thin plate of non-ferrous metal such as aluminum or its alloy having good thermal conductivity is used. In the prior art, a heat sink is manufactured by brazing this thin sheet metal, joining it by laser welding, ultrasonic welding, etc., but these joining methods are expensive because the device is expensive, so the manufacturing cost is high. was there.

In particular, since brazing is performed in a high-temperature furnace, there is a drawback that the material is annealed to lower the strength, workability is low, and the cost is high. Therefore, if the sheet metal is friction stir welded (FSW). This is advantageous because it is possible to avoid such drawbacks.

Friction stir welding is a simple device,
It is suitable for joining metals at low cost. An example of this friction stir welding is shown in Japanese Patent Publication No. 7-505090 (WO93 / 10).
935) or Tokumeihei Hyo No. 9-508073 (WO95 /
26254). As shown in FIG. 9 and FIG. 10, these methods are applied to the materials to be welded 212P, 21P.
The non-consumable pin 214 of the probe 216 is rotated while frictionally contacting the 2P 'joint, and the metal of the joint of the material to be welded is melted and joined by frictional heat.

As described above, the friction stir welding method is suitable for welding a thick plate having a thickness of 2 mm or more, because the non-consumable pin 214 is bitten into the material to melt and bond the material. When friction stir welding of thin sheet metal with a thickness of less than 2 mm is used as in the case of manufacturing heat sinks, the non-consumable pins must be thin and short. This is because the friction surface is required to melt the thin sheet metal material. Welding of sheet metal is physically impossible because it is too small to generate sufficient frictional heat and stirring to join. Further, since the thin sheet metal easily dissipates frictional heat and cannot retain the heat for melting the metal, it is difficult to weld the thin sheet metal also from this aspect.

[0006]

One object to be solved by the present invention is to provide a friction stir welding method and apparatus capable of reliably contacting non-consumable pins with a thin sheet metal to perform welding. is there.

Another object of the present invention is to provide a friction stir welding method and apparatus capable of reliably friction welding a thin sheet metal by suppressing the dissipation of friction heat from the sheet metal.

[0008]

A first basic problem solving means of the present invention is a friction stir welding method in which a non-consumable pin of a probe is frictionally brought into contact with a material to be welded and is rotated to weld the material to be welded. In order to provide a friction stir welding method, the non-consumable pin is eccentrically rotated so as to revolve around the rotation axis of the probe to stir weld the material to be welded. The non-consumable pins may have the same diameter, but preferably have a surface that expands downward and may be a hollow hollow pin.

The second basic problem solving means of the present invention is as follows.
In a friction stir welding method in which a non-consumable pin of a probe is brought into frictional contact with a material to be welded to rotate and weld the material to be welded, the non-consumable pin is composed of a hollow hollow pin. It is to provide a welding method.

In the case of welding by the first and second means for solving problems, when the material to be welded is mounted on the heat insulating mounting table and welded, even if the material to be welded is a thin plate, the dissipation of frictional heat is suppressed. Therefore, it is possible to reliably and efficiently perform friction welding of thin plates.

Further, when the material to be welded is not linear and has a complicated joint, the material to be welded is mounted on the movable table, and the probe is adapted to adapt to the traveling direction of the material to be welded. It is preferably connected to the inclination setting means via universal support means.

The third basic problem solving means of the present invention is to:
In a friction stir welding apparatus including a movable table on which a material to be welded is placed, a probe having a non-consumable pin that makes frictional contact with the material to be welded, and a rotary drive source that rotates the probe, the non-consumable pin is a probe. To provide a friction stir welding apparatus characterized in that the friction stir welding apparatus has a portion that is eccentrically attached from the rotation axis and has a diameter that expands downward.

A fourth basic problem solving means of the present invention is
In a friction stir welding apparatus including a movable table on which the material to be welded is placed, a probe having a non-consumable pin that makes frictional contact with the material to be welded, and a rotary drive source that rotates the probe, the non-consumable pin is Another object of the present invention is to provide a friction stir welding device, which is characterized by being formed of a hollow hollow pin.

A fifth basic problem solving means of the present invention is
In a friction stir welding apparatus including a movable table on which a material to be welded is placed, a probe having a non-consumable pin that makes frictional contact with the material to be welded, and a rotary drive source that rotates the probe, the non-consumable pin is a probe. The object is to provide a friction stir welding apparatus, characterized in that the friction stir welding apparatus is composed of a hollow hollow pin that is eccentrically attached from the rotation axis.

In these welding devices, when the movable table is a multi-stage XY table and a rotating mechanism is provided between the upper and lower XY tables, the material to be welded is welded along a complicated joining line including a curved line. can do.

As described above, when the non-consumable pin of the probe is eccentrically rotated so as to revolve around the rotation axis of the probe, even if the non-consumable pin is thin and short, the area of frictional contact with the thin metal material increases. Can generate sufficient frictional heat and agitation to bond the materials to be welded together, and is therefore suitable for welding thin sheet metals such as heat sinks. In particular, if the non-consumable pin has a portion that expands in diameter downward or is made of a hollow hollow pin, frictional heat and stirring force in the material to be welded can be increased. preferable.

Further, if the non-consumable pin is a hollow pin, a large friction can be generated between the material to be welded and the inner and outer surfaces of the hollow pin, but the hollow pin forms a slit forming a split. It is more preferable that the metal in a semi-molten state flows through the inside through the inside to improve the stirring effect.

When the material to be welded of the thin plate is mounted on the heat insulating mounting table and welded, the dissipation of frictional heat from the material to be welded is suppressed, so that the friction welding of the thin plate can be reliably and efficiently performed.

Further, in the case of joining a material to be welded, which is a complex line including a curved line, rather than a linear portion, the movable table on which the material to be welded is placed is a multi-stage XY table, and the upper and lower XY tables are joined. It is preferable to have a rotating mechanism between the tables. A portion of the material to be welded having a curved joining line can be welded to the material to be welded by moving the movable table by the rotating mechanism.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail with reference to the drawings. FIGS. 1 and 2 show a friction stir welding apparatus 10 suitable for carrying out the method according to the present invention. ,
In the illustrated embodiment, two metal plates 12P and 12P 'having a thickness t, which are the materials 12 to be welded, are joined so that their vertical side surfaces (which are substantially coincident with the probe rotation axis described later in FIG. 1) are mutually opposed. An example is shown.

As shown in FIGS. 1 and 2, the friction stir welding apparatus 10 of the present invention includes a probe 16 having a non-consumable pin 14 that makes frictional contact with the material 12 to be welded, and the probe 1
6 and a rotary drive source 18 for rotating 6.

In the embodiment shown in FIG. 1, the non-consumable pin 14 is mounted eccentrically from the rotation axis 16X of the probe 16 by a distance d, and the non-consumable pin 14 extends downward in the lower half portion of the probe and has a diameter expansion angle α. It has a portion 14E that expands in diameter. The appropriate eccentricity d is about 0.5 mm or less, and the expansion angle α
Is preferably 3 to 5 °.

Thus, the non-consumable pin 1 of the probe 16
4 is attached eccentrically from the rotation axis 16X of the probe 16, the non-consumable pin 14 rotates about the rotation axis of the probe 16 as the probe 16 rotates. It means revolving (eccentric rotation) around the rotation axis 16X of. Therefore,
Compared with the case where the non-consumable pin 14 rotates around the rotation axis 16X of the probe 16, the area in which the non-consumable pin 14 makes frictional contact with the material to be welded increases, and sufficient frictional heat and agitation to bond the material to be welded are obtained. Forces can be generated and therefore sheet metal can be reliably welded.

In particular, the expanded diameter portion 14 of the non-consumable pin 14
Since E has a larger outer diameter toward the lower side, it serves to increase the frictional force and the stirring force in the material 12 to be welded together with the eccentricity of the non-consumable pin 14, and therefore the molten metal fuses better. The welding strength can be improved.

In the configuration of FIG. 2, the non-consumable pin 14 is concentric with the rotation axis 16X of the probe 16, but the non-consumable pin 14 is composed of a hollow hollow pin 14H. The hollow hollow pin 14H preferably has opposing slits 15 that communicate the inside and the outside, but the slits 15 are
They do not necessarily have to face each other, and they are offset in the circumferential direction, offset in the vertical direction, and three or more slits 1
5 may be provided.

As described above, the non-consumable pin 14 is the hollow pin 1.
4H, the non-consumable pin 14 has a probe 16
Even if it is concentric with the axis of rotation 16X, a large amount of friction can be generated between the material 12 to be welded and the inner and outer surfaces of the hollow pin 14H, and therefore sufficient friction heat can be obtained even with thin sheet metal. In particular, it is suitable for surely performing friction welding of thin sheet metal.

Further, the metal in a semi-molten state flows into the hollow pin 14H from one of the two slits 15 forming the split of the hollow pin 14H, and heat is further generated in the hollow portion to become a molten state. Since the metal in a molten state flows out from the other slit by the metal flowing in from the slit, the stirring effect can be further improved, so that a good friction stir weld without voids can be obtained.

Friction stir welding apparatus 10 shown in FIGS. 1 and 2.
Can be used, for example, to manufacture a flat type heat sink 20 as shown in FIG. The heat sink 20 includes a flat substrate 22 and an embossed plate 2
4 and a portion 24a where the embossing plate 24 engages with the substrate 22.
It is manufactured by welding in. Substrate 22 and embossing plate 24
Is made from a sheet of aluminum or its alloy. In FIG. 3, reference numeral 26 is the substrate 22 embossing plate 2
4 are cooling passages formed between the cooling passages 4 and 4.

A method of friction stir welding of such a flat heat sink is shown in FIGS. 4 and 5, in which the substrate 22 and the embossing plate 24 are vertically overlapped with each other, and the probe 16 of the friction stir welding apparatus 10 is used. The non-consumable pin 14 is rotated while being in frictional contact with the non-consumable pin 14 by penetrating through the upper embossing plate 24 and reaching up to a position where the plate thickness reaches about half the plate thickness of the substrate 22.

In the example of FIGS. 4 and 5, the non-consumable pin 14 is used.
2 is shown in the form of FIG. 2, but it may be of the form of FIG. Also, in the example of FIG.
The probe 16 rotates about a vertical rotation axis 16X, but in the example of FIG. 5, the probe 16 has a rotation axis 16 inclined at an angle θ with respect to the normal to the horizontal surface of the material to be welded.
It is rotating around X. As shown in FIG. 5, when the probe 16 is rotated around the inclined axis 16X of rotation, the molten material is agitated vertically and laterally in the joint, so that it is subjected to a good agitation action and a good quality of bonding without voids. You can get a part.

In the embodiment shown in FIGS. 4 and 5, the substrate 22 and the embossed plate 24, which are the materials 12 to be welded, are mounted on the heat insulating mounting table 28 and welded. With this configuration, it is possible to prevent the small frictional heat of the thin plate material to be welded from being diffused, hold the frictional heat in the material to be welded, and improve the welding efficiency.

A typical example of the apparatus 100 for friction stir welding with the axis of rotation 16X tilted is shown in FIG. The welding apparatus 100 includes an XY table 102 as a movable table, and the heat insulating mounting table 28 is mounted on the XY table 102. The probe 16 is mounted on a drive shaft 104 connected to a rotary drive source 18, which is supported by universal support means 106 in the form of a ball joint mounted on a frame (not shown). The inclination angle setting means 108 includes the drive shaft 10.
4 comprises an oscillating drive source in the form of a hydraulic cylinder 110 having a piston 110a pivotally connected to 4.

The XY table 102 comprises an X table 114X and a Y table 114Y which are linearly driven in the X and Y directions by linear drive sources 112X and 112Y including servo motors (or pulse motors) for the X and Y directions. In the illustrated form, the Y table 114Y is on the bottom and the X table 114X is on the top, and the heat insulating mounting table 28 is the X table 114.
It is mounted on the X.

The operation of the welding apparatus 100 will be briefly described. The material 12 to be welded is placed on the heat insulating mounting table 28 and fixed to the heat insulating mounting table 28 by an appropriate means. The piston 110a of the hydraulic cylinder 110, which is the rocking drive source, is set to an appropriate length to set a predetermined tilt angle θ of the drive shaft 104. In this state, the rotary drive source 18 is rotationally driven to frictionally rotate the probe 16 while pressing the probe 16 against the material 12 to be welded to friction weld the material 12 to be welded. The probe 16 may have the form shown in FIG. 1 or the form shown in FIG. The material 12 to be welded is the XY table 102.
Is moved according to a program previously stored in a control device such as a microcomputer (not shown) so that the probe 16 moves relatively along the joint.

The welding apparatus 100 is the XY table 1 shown in FIG.
Instead of 02, a multistage, for example, two-stage XY table 116 as shown in FIG. 7 can be provided. The two-stage XY table 116 includes a rotating mechanism 1 such as a mega torque motor between an upper XY table 118 and a lower XY table 120.
22 is provided. The two-stage XY table 116 is different from the lower XY table 118 in the upper XY table 120.
Is preferably used for welding a joint having a complicated joint line including the curve of the material 12 to be welded by rotating (angular displacement). 7, reference numerals 124 and 126 denote upper and lower X tables, 128 and 130 denote upper and lower Y tables, and 132 and 134 denote upper and lower X servo motors (or pulse motors) 136 and 138, respectively. The upper and lower Y servo motors (or pulse motors) are shown.

Next, a method for welding the flat type heat sink 20 shown in FIG. 3 using the two-stage XY table 116 shown in FIG. 7 will be described in detail with reference to FIG. The plates 22 and 24 of the heat sink 20, which is the material to be welded, are placed and fixed on the X table 124 of the upper XY table 118.
The joining line of this heat sink 20 is shown in FIG.
As shown in (B), it is assumed that the four corners are curved trapezoids.

As shown in FIG. 8, the welding starts from point a, transitions to point b, point c, point d, point e, point f, point g, and point h, and returns to point a and ends. . During this time, between points ab and cd
The welding shifts linearly in the interval ---, but the welding shifts in a curve between the points bc, between the points de, and the like. When welding is started from the point a, the central axis of the rotating mechanism 122 is
Initially in position A. In this state, the probe 16 is held at the point a to start welding, and X of the upper XY table 118 is held.
Move the table 124 in the direction of the arrow X to move the welding to the arrow X '.
In sequence.

When the welding is transferred from the point a to the point b, the lower XY table 1 is moved along with the movement of the upper X table 124.
20 Y table 130 (not shown in FIG. 8).
8A is moved upward so that the rotation axis of the rotating mechanism 122 is located at B in FIG. 8A when the welded portion reaches the point b. This position B is a position where the joining line becomes the center of the radius R1 of the curve between the points bc.

When the welding reaches the position b, the rotating mechanism 122
Moves the upper XY table 118 about 90 degrees around the position B.
° Welding proceeds while rotating. Therefore, welding is performed along the curve between the points bc and the state shown in FIG. 8B is obtained.

Similarly, the upper X table 124 is moved in the X direction between the points cd to perform linear welding, and thereafter, similarly, curve welding between the points de (radius R2) and linear welding between the points ef are performed. , Curve welding between points fg (radius R3), straight line welding between points gh, and curve welding between points ha (radius R4) are sequentially performed. These straight line welding and curve welding are performed by driving the upper and lower XY tables 118 and 120 and the rotating mechanism 122 according to a program stored in advance in a control device such as a microcomputer (not shown).

Other welding lines of the heat sink 20 can also be performed while moving the material on the upper and lower XY tables and the rotating mechanism according to a predetermined program.

In the above embodiment, the case where the friction stir welding of the present invention is used for manufacturing the heat sink has been described, but it is needless to say that the present invention can be used for welding thin sheet metal other than the heat sink.

[0043]

According to the present invention, as described above, since the non-consumable pin of the probe eccentrically rotates so as to revolve around the rotation axis of the probe, compared to the case where the probe rotates about the rotation axis of the probe. As a result, the area where the non-consumable pin makes frictional contact with the material to be welded increases, and sufficient frictional heat and stirring force for joining the material to be welded can be generated, so that the thin sheet metal can be reliably welded.

In particular, if the non-consumable pin has an enlarged diameter portion in which the outer diameter increases downward, or if the non-consumable pin is composed of a hollow hollow pin, the non-consumable pin is eccentric to the inside of the material to be welded. Since it increases the frictional force and stirring force at
The molten metals fuse better and the welding strength can be improved.

Further, when the non-consumable pin is a hollow pin in the form of a split pin, even if the non-consumable pin is concentric with the axis of rotation of the probe, there is a gap between the material to be welded and the inner and outer surfaces of the hollow pin. In addition to generating a large amount of friction, the metal in a semi-molten state moves in and out through the slits of the split pins to improve the stirring action, and therefore, it is possible to efficiently weld a thin sheet metal with high strength.

When the material to be welded of the thin plate is mounted on the heat insulating mounting table and welded, the dissipation of frictional heat from the material to be welded is suppressed, so that the friction welding of the thin plate can be reliably and efficiently performed.

If the movable table on which the material to be welded is placed is composed of a multi-stage XY table and a rotating mechanism is provided between the upper and lower XY tables, the portion where the joining line of the material to be welded is a curve can be changed by the rotating mechanism. The movable table can be moved to easily weld the material to be welded.

[Brief description of drawings]

FIG. 1 is an explanatory diagram illustrating the principle of one mode of a friction stir welding method according to the present invention.

2A and 2B are diagrams for explaining the principle of another embodiment of the friction stir welding method according to the present invention. FIG. 2A is an explanatory view thereof and FIG. 2B is a cross-sectional view of a non-consumable pin.

3A and 3B show a flat type heat sink suitable for manufacturing by the method of the present invention, FIG. 3A is a plan view thereof, and FIG. 3B is a sectional view thereof.

FIG. 4 is an explanatory view illustrating one mode of manufacturing the heat sink of FIG. 3 by the welding method of FIG. 1 or FIG.

5 is an explanatory view explaining another embodiment of manufacturing the heat sink of FIG. 3 by the welding method of FIG. 1 or FIG.

FIG. 6 is a front view of a welding apparatus suitable for welding in the form of FIG.

7 shows a two-stage XY table used in place of the XY table of the welding apparatus in FIG. 5, FIG. 7 (A) is a plan view thereof, and FIG. 7 (B) is a front view thereof.

8 shows a method for manufacturing a heat sink using the apparatus of FIG. 7, FIG. 8 (A) shows a state where one linear welding is performed, and FIG. 8 (B) shows the following. It is a figure which shows the state which is performing curvilinear welding.

FIG. 9 is a perspective view showing a state where a thick plate is friction stir welded by a conventional technique.

FIG. 10 is a front view showing the welding state of FIG. 9 with a section of the welding material.

[Explanation of symbols]

10 Friction Stir Welding Equipment 12 Materials to be Welded 12P, 12P 'Metal Plate 14 Non-consumable Pin 14E Expanded Portion 15 Slit 16 Probe 16X Rotation Axis 18 Rotation Drive Source 20 Flat Type Heat Sink 22 Substrate 24 Embossing Plate 24a Substrate of Embossing Plate Joint part 26 Cooling passage 28 Heat insulating mounting table 100 Friction stir welding apparatus 102 XY table 104 Drive shaft 106 Universal supporting means 108 Angle setting means 110 Hydraulic cylinder 110a Pistons 112X and 112Y Servo motors (or pulse motors) 114X and 114Y Movable table 116 Two-stage XY table 118, 120 Upper and lower XY table 122 Rotation mechanism 124, 126 X table 128, 130 Y table 132, 134 X servo motor (or pulse motor) 136, 138 Y servo motor ( Or pulse motor)

Claims (10)

[Claims] 1. In a friction stir welding method in which a non-consumable pin of a probe is brought into frictional contact with a material to be welded while rotating to bring the material to be welded into contact, the non-consumable pin revolves around the axis of rotation of the probe. The friction stir welding method is characterized in that the material to be welded is stirred and welded while being eccentrically rotated. 2. The friction stir welding method according to claim 1, wherein the non-consumable pin has an enlarged diameter portion whose diameter is expanded downward. 3. The friction stir welding method according to claim 1, wherein the non-consumable pin comprises a hollow hollow pin. 4. A friction stir welding method in which a non-consumable pin of a probe is brought into frictional contact with a welding material while rotating so as to weld the welding material, wherein the non-consumable pin comprises a hollow hollow pin. A friction stir welding method, wherein friction and movement of metal are generated between a material and inner and outer surfaces of the hollow pin. 5. The friction stir welding method according to claim 1, wherein the welding material is mounted on an adiabatic mounting table and welded. 6. The friction stir welding method according to claim 1, wherein the welding material is mounted on a movable table, and the probe is the welded object on the movable table. A friction stir welding method characterized in that the friction stir welding means is connected to a tilt setting means through a universal means so as to adapt to the traveling direction of the material. 7. A movable table on which a material to be welded is placed,
In a friction stir welding apparatus comprising a probe having a non-consumable pin that makes frictional contact with the material to be welded, and a rotary drive source that rotates the probe, the non-consumable pin is eccentrically attached from the rotation axis of the probe, Further, the friction stir welding apparatus is characterized by having a portion whose diameter is expanded downward. 8. A movable table on which a material to be welded is placed,
In a friction stir welding apparatus comprising a probe having a non-consumable pin that makes frictional contact with the material to be welded and a rotary drive source that rotates the probe, the non-consumable pin is a hollow hollow pin. And friction stir welding equipment. 9. A movable table on which a material to be welded is placed,
In a friction stir welding apparatus comprising a probe having a non-consumable pin that makes frictional contact with the material to be welded and a rotary drive source that rotates the probe, the non-consumable pin is attached eccentrically from the rotation axis of the probe. A friction stir welding device characterized by being made of hollow hollow pins. 10. The friction stir welding apparatus according to claim 7, wherein the movable table is a multistage X
A friction stir welding apparatus comprising a Y table and having a rotating mechanism between the upper and lower XY tables.