JP2002126882A - Friction-agitation jointing equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a friction-agitation jointing equipment capable of conducting jointing without forming a recess nor cavity. SOLUTION: The friction-agitation jointing equipment is provided with a rotor 2 and a servomotor 4, and the rotor 2 is composed of a rotor supporting member 3 and a rotor body 9. To the rotor supporting member 3, a rotating force is transmitted from the servomotor 4 through a timing belt 24. On the rotor 2, a guide hole 17 is formed along the axial line L. From a sending out means 23 provided on the upper side, a metal wire material 8 is sent out, and from the tip of the pin 7, the metal wire material 8 is sent out. In jointing, the metal wire material 8 is softened by the frictional heat caused by the rotation of the rotor 2, agitated, and jointed integrally with a base metal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction stir welding apparatus that softens, stirs, and welds an object by frictional heat generated by rotation.

[0002]

2. Description of the Related Art FIG. 10 is a perspective view showing a typical conventional friction stir welding apparatus 50. In friction stir welding equipment,
A rotor 53 has a pin 52 protruding from the center of the columnar tip 51. The rotor 53 is inserted into and joined to a work 54 while rotating at a high speed. Rotor 5 that rotates at high speed
When the third pin 52 is pressed against the work 54, the work is softened by frictional heat. When the work is further pressed, the pin is inserted into the softened work, and the base material around the pin undergoes plastic flow with the rotating pin and is stirred. You.

When two works 54a and 54b are continuously butt-joined, the two works 54a and 54b are joined together.
The rotating pin 52 is inserted into the butting portion 54b, and the rotor is moved along the butting portion. Then, the plastic flow portion where the pin has passed hardens, and the two workpieces 54a, 5a
4b will be butt-joined.

[0004]

At the tip of the rotor, a pin 52 projects from the center of the cylindrical end face.
The pin 52 is inserted with the cylindrical end face pressed against the work surface. The cylindrical end face pressed by the work is hereinafter referred to as a shoulder.

When the rotor 53 moves while rotating clockwise as viewed from above, the material on the left side of the rotor in the traveling direction is pressed by the shoulder portion to be pressed.
Since there is a tendency to move to the right side of the rotor, defects (small cavities) are apt to be formed on the left side of the joining line in the joined work.

Further, if the base material scatters from the pin portion and the shoulder portion, plastically flows so as to swell around the shoulder portion, or if there is a large gap in the work joint,
The joint site becomes concave (undercut) as much as it is filled with the base material. When such a gap is excessive, a cavity is formed at the joint portion in addition to the undercut.

In order to prevent such a cavity from being formed, it is necessary to strictly control the gap at the joint and to minimize the gap. In addition, since recesses are likely to be formed, the appearance deteriorates, the product cannot be made unpainted, and there is a problem that the amount of putty increases when painting.

In order to prevent such a concave portion from being formed, a convex portion projecting in the thickness direction of the joint portion is provided along the longitudinal direction of the joint portion, and is rotated from the convex portion side or the side opposite to the convex portion. A method of inserting and joining a child has been proposed. In other words, in the joint portion, by filling the material of the amount of the base material flowing out or the volume of the gap of the joint portion from the convex portion, it is attempted to prevent the joint portion from becoming concave or forming a cavity. Is what you do.

[0009] However, in these methods, the provision of the convex portion at the joint portion itself leads to an increase in the cost of the material in terms of work. In order to provide a margin for the above-mentioned amount of compensation, the width of the convex portion must be larger than the diameter of the shoulder portion of the rotor, and after joining, a portion of the convex portion remains and it is necessary to cut that portion. There is. When the width of the gap fluctuates in accordance with the length direction of the joining portion, there is a problem that the joining surface does not have a constant height.

[0010] Another prior art for preventing such a recess is WO96 / 38256. In this prior art, as shown in FIG. 11, an aluminum material having substantially the same quality as the work is sent out from the center of the pin. However, in this method, a part of the cavity in the rotor is filled with an aluminum material in advance, and the aluminum material is heated in advance or separately heated (b). The material is driven to be delivered by the spring washers (a) and (b) or the spiral rotary auger (auger) (c). When all the aluminum material is delivered, the aluminum material is finished (there is a limit).

Thus, the prior art shown in FIG. 11 has many problems. As another prior art, there is JP-A-11-156561. In this prior art, a hole filling material corresponding to a pin diameter is supplied after joining in order to fill a hole generated after a pin is pulled out. Therefore, it is not possible to prevent cavities and recesses generated during joining.

An object of the present invention is to provide a friction stir welding apparatus in which a concave portion is not formed at a joining portion without previously processing a work side.

[0013]

According to the first aspect of the present invention, a tip of a high-speed rotating rotor is pressed against a workpiece.
In a friction stir welding apparatus for softening a contact portion between the distal end portion and the workpiece by frictional heat due to rotation and agitating and joining the workpiece, a delivery unit for delivering a metal material from a rotor distal end is provided. The friction stir welding apparatus is characterized in that, at the time of welding, the metal material sent out from the tip of the rotor is also softened by frictional heat, stirred and integrated with the workpiece.

According to the present invention, the material to be joined is softened by rotating the rotor at a high speed and pressing against the material to be joined.
Stir and join. Here, in the present invention, the metal material is fed from the tip of the rotor at the time of joining. The fed-out metal material is also softened by frictional heat generated by the high-speed rotating rotor, stirred together with the softened material to be joined, and hardened to join the material to be joined. In this way, the metal material is supplied from the tip of the rotor at the time of joining, so that a recess formed at the time of joining and a recess formed at the joining end point can be prevented. In addition, since the metal material is supplied to fill the recess, it is not necessary to form the workpiece side in advance. In addition, since the delivered metal material is softened by frictional heat due to rotation, it is not necessary to overheat in advance as in the prior art shown in FIG. 11, and it is not necessary to provide a heating means or the like.

According to a second aspect of the present invention, the metal material is a wire, and the feeding means continuously feeds the metal wire.

According to the present invention, since the metal material is a wire, it can be continuously fed, and there is no limitation as in the prior art shown in FIG.

According to a third aspect of the present invention, the metal wire is an aluminum alloy material having substantially the same hardness as that of the object to be welded.

According to the present invention, since the metal material supplied at the time of joining is an aluminum alloy having substantially the same hardness as that of the object to be joined, the metal material is easily integrated with the object to be joined, and sufficient joining is achieved. Strength is obtained.

According to a fourth aspect of the present invention, the feeding means has a pair of rollers for sandwiching the metal wire, and continuously feeds the metal wire by rotating the roller.

According to the present invention, the metal wire can be fed smoothly with a simple structure by feeding the metal wire between the pair of rollers. Further, the feed amount of the metal material can be controlled with high accuracy.

According to a fifth aspect of the present invention, an insertion hole into which a metal wire is inserted is formed, and a guide member for guiding the metal wire is provided immediately after the roller of the feeding means.

The metal wire buckles when a strong compressive load is applied in the longitudinal direction. In the present invention, since the guide member for inserting the metal material is provided immediately after the roller of the feeding means for feeding the metal wire material, it is possible to prevent the metal wire material from buckling due to the feeding force from the roller.

According to a sixth aspect of the present invention, there is provided a linearly moving member which is relatively linearly moved with respect to the rotor in the direction of the rotation axis and has an insertion hole through which a metal wire is inserted. Is formed with a guide hole that penetrates along the rotation axis and guides the metal wire, and is connected to the guide hole, and a recess is formed in which the distal end of the rectilinear moving member is displaceably inserted, and is inserted into the recess. A coil spring through which a metal wire is inserted is provided between the end surface of the rectilinear member and the bottom surface of the recess.

According to the present invention, the rotor moves linearly in the axial direction to press the tip against the workpiece. For example, assuming that the linearly moving member is at a fixed position, the linearly moving member and the rotor relatively linearly move.

A guide hole into which a metal wire is inserted penetrates the rotor, and a tip end of the linearly moving member is inserted into a recess connected to one end of the guide hole. The linear moving member and the rotor at the fixed position side, the linear movement of the rotor, the tip of the linear moving member to be inserted into the recess, the interval between the bottom of the recess is expanded, thereby, A space that allows the bending of the metal wire is expanded, and the metal wire may buckle.

In the present invention, in view of this point, a coil spring is provided in the recess, and a metal wire is inserted through the coil spring. The coil spring can prevent the metal wire from bending in the recess, and the coil spring can expand and contract according to the displacement of the interval between the tip of the rectilinear moving member and the bottom of the recess. . In this way, the buckling of the metal wire can be reliably prevented with a simple configuration.

[0027]

FIG. 1A is a view showing the structure of a friction stir welding apparatus 1 according to a first embodiment of the present invention.
(B) is an enlarged view of the tip of the friction stir welding apparatus 1. The friction stir welding apparatus 1 includes a rotor 2, a servomotor 4 serving as a rotation drive source, an electromagnetic brake 5, a delivery unit 23 for delivering a metal wire 8, and a support member (not shown) for supporting these components. 2 includes a rotor main body 9 and a rotor holding member 3 that holds the rotor main body 9. The rotor main body 9 has a substantially columnar shape, the center axis is the rotation axis L, the tip is tapered, and the tip is formed with a column 6 coaxial with the rotation axis L, and the lower end surface of this column is shouldered. The pin 7 protrudes from the portion 6a along the axis L. Guide holes 17 that penetrate along the rotation axis L and guide the metal wire 8 are formed in the rotor body 9 and the rotor holding member 3. The guide hole 17 is opened at the tip of the pin 7, and the metal wire 8 sent from the sending means 23 is sent from the tip of the pin.

The rotor 2 is rotated around the rotation axis L at a high speed, and is advanced along the rotation axis L. Then, the pin 7 at the tip is pressed against the work to be joined, the work is softened by frictional heat, the pin 7 is inserted into the work, and further stirred by the rotating pin 7 to generate plastic flow. Further, the lower end surface 6a of the cylindrical portion 6 is pressed against the work, and frictional heat is generated also on this lower end surface 6a and the work is stirred. At the same time, the metal wire 8 is sent out from the tip of the pin by the sending-out means 23. Then, the delivered metal wire 8 is also softened by the frictional heat generated by the rotation of the pin 7 to generate a plastic flow, and is similarly stirred and integrated with the work that has generated the plastic flow.

After such stirring, in the case of spot joining, the rotor 2 is raised along the axis L and the pins are pulled out. In the case of continuous joining, the rotor 2 and the workpiece are moved relative to each other by an arbitrary length in a direction perpendicular to the rotation axis L to join continuously, and then the rotor 2 is raised and the pins 7 are pulled out. Conventionally, when a pin is pulled out, a pin hole is formed. However, in the present invention, by supplying the metal wire 8, a metal material enough to fill the pin hole can be supplied. Without forming a hole,
Friction stir welding can be performed. Also, by supplying the metal material during the bonding, the formation of undercuts and cavities can be prevented. In this manner, two workpieces can be joined without forming a recess. The metal wire 8 to be sent out is a metal material of substantially the same hardness and substantially the same hardness as the work, and in the present embodiment, the work and the metal wire are aluminum alloy of the same quality.

The rotor holding member 3 has a cylindrical shape having the rotation axis L of the rotor 2 in common, and has a rotor body 9 at the lower end.
Is inserted, and the rotation about the rotation axis L and the rotation axis L
The rotor body 9 is held in a state where the movement in the direction is prevented. A plurality of splines 10 are formed on an outer peripheral portion of the rotor holding member 3 in parallel with the rotation axis L, and three annular spline receivers 1 into which the splines 10 are fitted.
1, 12 and 13 are supported by bearings 14, 15 and 16 respectively so as to be rotatable around the rotation axis L.
Each of the bearings 14, 15, 16 is fixed to a support member. With such a configuration, the rotor holding member 3 is rotatable about the rotation axis L and movable in the rotation axis direction L. It is supported by the support member.

The servo motor 4 is also fixed to the support member, and the output shaft 20 is disposed parallel to the rotation axis L of the rotor 2, and is rotatably supported by the support member by a bearing 21. The toothed belt wheel 23 is attached to the section. Further, a toothed belt wheel is formed on the outer periphery of the center spline receiver 12 of the three spline receivers, and a timing belt 24 is wound from the toothed belt wheel to the toothed belt wheel 23 of the servo motor 4. Can be hung. With this configuration, the rotor 2 can be driven to rotate around the rotation axis L by driving the servo motor 4 to rotate.

A screw shaft 30 is provided above the rotor holding member 3.
Are rotatably supported by a support member by a bearing 31 around a rotation axis L. The screw shaft 30 functions as a linearly moving member that linearly drives the rotor 2 and relatively linearly moves with respect to the rotor 2. Also, the rotor holding member 3
At the upper end of the screw shaft 30 around the rotation axis L
The nut member 32 which is a ball screw screwed into the nut is fixed. The screw shaft 30 is rod-shaped, and has a flange 33 at the center.
Is formed, an external thread is formed below the flange 32, and the bearing 31 is disposed on the flange 33. The bearing 31 is a radial bearing and a thrust bearing, and receives a thrust pressing force from the flange 33 in the thrust direction. The electromagnetic brake 5 is provided above the bearing 31. The electromagnetic brake 5 is fixed to a support member,
When the current is applied and excited, the screw shaft 30
, And the rotation of the screw shaft 30 around the rotation axis L is braked.

Therefore, when the servomotor 4 is rotated forward (clockwise as viewed from above) with the electromagnetic brake turned off, the rotor holding member 3 rotates about the rotation axis L together with the screw shaft 30. The screw shaft 30 is a right-hand screw. When the electromagnetic brake 5 is turned on and the rotation of the screw shaft 30 is stopped in a state where the rotor holding member 3 is rotated clockwise,
The nut member 32 fixed to the rotor holding member 3 rotates around the screw shaft 30, and the nut member 32 and the rotor holding member 3 move forward (down) in the direction of the rotation axis L. The rotating force from the servomotor 4 is transmitted to the rotor holding member 3,
In addition, since the movement in the direction of the rotation axis L is permitted by the spline, the rotor 2 can move straight while rotating. When the rotation direction of the servo motor 4 is reversed, the rotor 2 rises while rotating in the reverse direction. Also, when the rotor holding member 3 is raised, the lower end of the screw shaft 30 does not collide with the upper end surface of the rotor holding member 3 so that
The nut member 32 is fixed at a position separated from the upper end surface of the rotor holding member 3 as shown in FIG.

A delivery means 23 is provided above the electromagnetic brake 5. FIG. 2 is an enlarged view showing the feeding means 23.

The feeding means 23 has a pair of pinch rollers 25 and 26 rotatably supported by the support member, and pinches the metal wire 8 between the pinch rollers 25 and 26.
By rotating and driving the pinch rollers 25 and 26, the metal wire 8 is sent out toward the rotor 2.

The electromagnetic brake 5 holds the screw shaft 30,
The screw shaft 30 penetrates along the axis, and the metal wire 8
An insertion hole 29 through which is inserted is formed. Further, the electromagnetic brake 5 is provided with a guide 28 for guiding the metal wire 8 sent from the sending means 23. Guide 28
The front end faces between the pair of pinch rollers 25 and 26, and the metal wire fed from the pinch rollers 25 and 26 is inserted. Further, the tip 28a of the guide 28 is formed in a truncated conical shape, is arranged as close as possible between the pinch rollers 25 and 26, and the metal wire 8 immediately after being fed is inserted into the guide. Thereby, the sending-out means 23
Buckling of the metal wire 8 immediately after is prevented. The metal wire 8 introduced into the guide 28 is
Is inserted into the insertion hole 29.

FIG. 3 is an enlarged sectional view showing the vicinity of the lower end of the screw shaft 30. The metal wire 8 is fed by the feeding means 23
, And is led out toward the work from the tip of the pin of the rotor 2, so that a large compressive load acts in the axial direction,
The structure is easy to buckle. Therefore, it is necessary to prevent buckling from the delivery means 23 to the tip of the pin so as not to buckle. Hereinafter, a mechanism for preventing buckling will be described.

While the rotor 2 moves linearly in the axial direction, the delivery means 23, the electromagnetic brake 5, and the screw shaft 30
Is supported by a support member and is disposed at a fixed position with respect to the rotor 2 that moves linearly. That is, the screw shaft 30 and the rotor 2
, It is necessary to guide the metal wire 8 while allowing the relative movement.

For this purpose, a guide 42 is provided at the lower end of the screw shaft 30, which projects toward the rotor and has an insertion hole 29 through which the metal wire 8 is inserted, and the upper end of the rotor holding member 3 of the rotor 2. A recess 40 is formed in the portion, in which the guide 42 is inserted so as to be displaceable in the direction of the axis L. The recess 40 is formed along the axis L at the upper end of the rotor holding member 3,
The bottom 40 a communicates with the guide hole 17, and the metal wire 8 derived from the screw shaft 30 is guided to the guide hole 17.

Since the lower end 42a of the guide 42 is inserted into the recess 40 to allow relative displacement between the screw shaft 30 and the rotor 2, the lower end 42a of the guide 42 and the bottom 40a of the recess 40 A space is formed between them. Therefore, in the recess 40, the metal wire 8 led out from the lower end 42 a of the guide 42 is exposed to the space in the recess 40 before being inserted into the through hole 17 in the bottom 40 a of the recess 40. become. That is, buckling may occur during this time.

In view of this point, the coil spring 4 is
1 was provided. The coil spring 41 is disposed in the recess 40, through which the metal wire 8 is inserted, and closes a space between the metal wire 8 and the peripheral wall of the recess 40. Thereby, the metal wire 8 is prevented from bending in the recess 40, and buckling can be reliably prevented. Further, the coil spring 41 has elasticity, and the bottom 40 a of the recess 40 and the lower end 4
2a, the rotor 2 moves straight, and when the distance between the lower end 42a of the guide 42 and the bottom 40a of the recess 40 becomes smaller, the lower end 42a of the guide
When the space is large, it is expanded by the elastic force. In this way, it is always arranged between the lower end 42a of the guide 42 and the bottom a of the recess 40.

Next, a method of setting a pressing force at the time of joining will be described. The servo motor 4 is feedback-controlled so that the rotation speed is constant. If the detected rotation speed is lower than a set value, the servo motor 4 increases the current value so that the rotation speed increases, and is higher than the set value. In this case, lower the current value so as to lower the rotation speed. In other words, when the work is pressed by the tip of the rotor and the rotation torque of the servomotor 4 increases and the rotation speed decreases, the current supplied to the servomotor 4 increases. When the rotation torque decreases, the current is supplied to the servomotor 4. The current decreases. Therefore, the servo motor 4
The rotational torque of the servo motor 4 can be detected by detecting the current value of. Therefore, a current value of the servomotor 4 corresponding to a predetermined pressing force is set in advance, and when the detected current value reaches the set value, the electromagnetic brake 5 is controlled to be turned off, so that the pressing is performed. Set pressure.

Next, a first control method of the friction stir welding apparatus 1 during the welding operation to which the pressing force setting method is applied will be described with reference to a time chart shown in FIG. In addition,
4, pressing force, rotor position, electromagnetic brake,
Rotation direction of servo motor, servo motor torque, rotation of pinch rollers 25 and 26 of feeding means 23, rotor 2
3 is a time chart showing the horizontal position of the.

In the initial state, it is assumed that the rotor 2 is at the original position where the rotor holding member 3 has risen, and the servomotor 4 is rotating in the reverse direction (counterclockwise). That is,
It is assumed that the previous joining operation has been completed, and the rotor 2 has been lifted up and returned to the original position while being rotated in the reverse direction. At this time, the electromagnetic brake 5 is in the off state and is not excited. That is, the rotation of the screw shaft 30 is not restricted,
The rotor 2 rotates together with the rotor holding member 3, and the linear movement of the rotor 2 is stopped.

When the servo motor 4 is not rotating, the servo motor torque is 0. When the servo motor 4 is rotating forward, the value is +, and when it is reverse, the value is-. In this state, the rotor 2 does not press the work, and the pressing force is 0 (no load).
However, since the rotation is reversed, the servo motor torque is −
Becomes

In preparation for joining, the servo motor 4 is rotated forward (clockwise). Then, the servo motor torque becomes +. At this time, the screw shaft 30 is also rotating clockwise together with the nut member 32.

When the electromagnetic brake 5 is turned on, the screw shaft 3
0 is constrained, the nut member 32 rotates clockwise with respect to the screw shaft 30, and the rotating holding member 3 and the rotor 2 start to descend while rotating clockwise. Further, the servo motor torque increases by the amount of the linear movement of the rotor holding member 3 and the rotor 2. The brake torque of the electromagnetic brake 4 at this time is set to such an extent that a predetermined pressing force is sufficiently generated.

When the rotor 2 comes into contact with the work, the lowering of the rotor 2 stops, and a pressing force is generated. This also increases the servomotor torque. When the servomotor torque reaches a value corresponding to a predetermined pressing force, the electromagnetic brake 5 is turned off. As a result, the workpiece is pressed with a predetermined pressing force. Then, the horizontal position of the rotor 2 starts relative movement from the joining start point to the joining end point, and at the same time, the pinch rollers 25, which supply the metal wire 8,
The rotation of 26 is started. Then, the metal wire is sent out from the tip of the pin while the pressing force of the rotor is maintained.

At the tip of the pin, the base material is softened at a high temperature due to frictional heat, and the metal wire sent out also has a high temperature.
As shown in (1), it is softened and inserted into the base material. And
Since there is a relative movement between the rotor 2 and the work, the softened and inserted metal wire is sequentially taken into the base material. As a result, it is possible to supplement or increase the amount of the metal wire at the joint.

When the horizontal position of the rotor 2 reaches the joining end point, the rotation of the pinch rollers 25 and 26 is stopped to stop the feeding of the metal wire. The servomotor torque at this time is a load acting on the flange 33 of the screw shaft 30 which resists the pressing force of the rotor 2 due to the friction between the rotor tip and the work.

After the pressing, the servo motor 4 is rotated reversely (counterclockwise) and the electromagnetic brake 5 is turned on.
Then, the screw shaft 30 is restrained, the nut member 32 rotates counterclockwise with respect to the screw shaft 30, and the rotor 2 rises. Note that the servo motor torque at this time is equal to the rotor 2
Because it is the load when raising, it is slightly lower than when.

When the rotor 2 rises to the original position, the electromagnetic brake 5 is turned off and stopped. Since the movement amount from the original position to the work pressing position is set in advance, the electromagnetic brake 5 is turned off when the servo motor 4 is rotated by the rotation amount corresponding to the movement amount after the reverse rotation of the servo motor 4. I do. As a result, the rotor 2 returns to the original position.

One cycle of the joining operation is completed with the rotor returned to the original position. This state is the same as the state described above.

In the joining method described above, the pressing force at the time of pressing is controlled to be constant, but the pressing force may be controlled to be increased stepwise or steplessly. For example, when the servomotor torque reaches a predetermined first value, the electromagnetic brake is once turned off and pressed for a predetermined time, and then the electromagnetic brake 5 is turned on again,
When the servomotor torque reaches a second value larger than the first value, the electromagnetic brake 5 is turned off and pressed for a predetermined time. In this way, the pressing force can be increased stepwise.

At this time, the pressing force can be reduced by turning on the electromagnetic brake 5 and simultaneously rotating the servo motor 4 in the reverse direction.

In this embodiment, the case where the rotor tip is moved from the welding start point to the welding end point while the rotor tip is inserted into the workpiece and the rotor is continuously joined is shown in FIG. 6 (a). The workpiece may be intermittently joined by repeatedly inserting and extracting the tip of the rotor at different joining portions of the workpiece, and as shown in FIG. 6B, inserting a pin at each joining point of the workpiece. The work may be spot-joined in a spot-like manner.

Further, in the present embodiment, in the time chart of FIG. 4, the stopping of the feeding of the metal wire and the raising of the rotor (pulling out) are performed at the same time, but the time corresponding to the length of the pin 7 corresponds to the length of the metal wire. 8 may be delayed. That is, as shown in FIG. 7, while the pin 7 is in the work, the metal wire 8 is continuously fed out so that the pin 7
Is not hollow after being pulled out, and is covered with the metal wire 8. This is not limited to the case of continuous joining, but also at each end point in the case of intermittent joining shown in FIG. 6A and at each joining point of spot joining shown in FIG. The metal wire 8 may be sent out at the time of drawing.

In this embodiment, the rotor 2 rotates, but the metal wire 8 is fixed to the pinch rollers 25, 26.
, The metal wire 8 does not rotate (rotate).

Next, an embodiment in which the metal wire is aluminum will be described. The maximum temperature of a joint caused by frictional heat is usually 450 ° C. (sometimes reaches 500 ° C.) (Light Metal Welding Vol. 37 No. 9 p13). The normal temperature of aluminum is set to 20 ° C.

Here, the normal stress F (Kg / mm ² ) for pushing the object B into the base material A is given assuming that the yield stress of the base material A is Y (Kg / mm ² ) (FIG. 8). F = 2.82Y (Nikkan Kogyo Shimbun, Metal Materials Science, p. 220), and in the case of aluminum, Y = 12.3 at room temperature (see p.
221) At the melting point of 660 ° C., Y = 0.

Here, it is assumed that the temperature and the yield stress are almost inversely proportional, and if the margin ratio is doubled, the yield stress at the time of friction stirring at 450 ° C. is Y _{at450 ° C.} = 12.3 × (660−450) / (660-
20) × 2 = 8.07 Therefore, the normal stress F when B is pushed in at 450 ° C. is: Y _{at450 ° C.} = 2.82 × Y at _{450 ° C.} (Kg / mm ² ).

Although there are few documents showing the relationship between temperature and yield stress, it is considered that the yield strength in the JIS test method is proportional to the yield stress. About the proof stress, the graph of FIG. 9 (Aluminum Handbook p42 edited by Light Metal Association)
As shown in FIG. 5, almost all kinds of aluminum alloys have a proof stress of 50 N / m
m ² (5.1 kg / mm ² ), which is considered to be less than 450 ° C., which is the maximum temperature of friction stir welding, and consequently, it is considered correct to assume that it is almost inversely proportional.

On the other hand, if the aluminum wire to be sent is 1.2 mmφ, the sectional area is 1.13 mm ² . Therefore,
As normal stress × cross-sectional area, 22.8 × 1.13 = 25.8 (Kg) (1), and the aluminum wire may be driven and supplied with a force of 25.8 kg or more. On the other hand, as an example of a wire supply device that is commercially available as an arc welding device, a maximum torque of a motor for driving a feeding roll: 30.6 kg · mm Motor rotation → a reduction ratio of a rotation of the feeding roll: 21.04 The feeding roll is effective. With a radius (wire driving radius) of 17.5 mm, the driving force in the wire feeding direction at the wire contact point of the ball feeding roll is 30.6 × 21.04 ÷ 17.5 = 36.8 kg (26.8) ).

In general, there is a slip between the feeding roll and the wire to be fed, so that the driving force of the feeding roll in the wire feeding direction and the wire feeding force (pushing force).
Although it does not necessarily match, increase the pressing force by the pressure roll. The circumferential portion of the portion of the feed roll that contacts the wire has a large frictional force, or a small protrusion or the like is provided on the surface of the portion of the feed roll that contacts the wire to prevent slippage. A plurality of sets of feeding rolls and pressure rolls are provided (for example, two sets are connected). For example, various proposals have been made to prevent slipping between the feeding roll and the feeding wire. If these methods are used, the slip can be reduced as much as possible, and the wire feeding force (pushing force) can be reduced. Can be brought as close as possible to the driving force of the feeding roll in the wire feeding direction. Therefore,
With (2), (1) can be realized, and the aluminum wire can be inserted (pressed) into the aluminum base material.

[0065]

As described above, according to the present invention, the metal material is supplied from the tip of the rotor at the time of joining, so that the recess formed at the time of joining and the recess formed at the end point of joining are prevented. can do. In addition, since the metal material is supplied to fill the recess, it is not necessary to form the workpiece side in advance. Further, since the metal material sent out is softened by frictional heat due to rotation, it is not necessary to overheat in advance, and it is not necessary to provide a heating means or the like.

According to the present invention, since the metal material is a wire, it can be continuously fed.

According to the present invention, the metal material supplied at the time of joining is an aluminum alloy having substantially the same hardness as that of the object to be joined. Bonding strength is obtained.

Further, according to the present invention, the metal wire can be sent out with a simple structure by feeding the metal wire between the pair of rollers. Further, the feed amount of the metal material can be controlled with high accuracy.

According to the present invention, since the guide member for inserting the metal material is provided immediately after the roller of the feeding means for feeding the metal wire material, it is possible to prevent the metal wire material from buckling due to the feeding force from the roller. It is.

According to the present invention, the coil spring is provided in the recess, and the metal wire is inserted through the coil spring, so that the buckling of the metal wire can be prevented.

[Brief description of the drawings]

FIG. 1 is a front view showing a friction stir welding apparatus 1 according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a feeding means 23.

FIG. 3 is an enlarged view of the vicinity of a screw shaft 30;

FIG. 4 is a time chart showing a control method of the friction stir welding apparatus 1.

FIG. 5 is a diagram showing a tip of a rotor 2 at the time of joining.

FIG. 6 is a diagram illustrating a method of intermittently joining.

FIG. 7 is a view showing feeding of a metal wire rod 8 when the rotor 2 is pulled out.

FIG. 8 is a diagram illustrating a relationship between a base material A and an object B;

FIG. 9 is a graph showing a relationship between proof stress and temperature of aluminum.

FIG. 10 is a perspective view showing a typical conventional friction stir welding apparatus 50.

FIG. 11 shows a prior art friction stir welding apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Friction stir welding apparatus 2 Rotor 3 Rotor holding member 4 Servo motor 8 Metal wire 9 Rotor main body 30, 56 Screw shaft 32, 60, 81 Nut member 41 Outer screw 80 Outer screw member 23 Sending means

Claims (6)

[Claims] 1. A tip part of a high-speed rotating rotor is pressed against an object to be joined, a contact part between the tip part and the object to be joined is softened by frictional heat generated by rotation, and the object is stirred by stirring. In a friction stir welding apparatus for joining, there is a delivery means for sending out a metal material from a rotor tip, and at the time of welding, the metal material sent from the rotor tip is also softened by frictional heat, stirred and integrated with a workpiece. A friction stir welding apparatus characterized in that the stir welding is performed. 2. The friction stir welding apparatus according to claim 1, wherein the metal material is a wire, and the feeding means continuously feeds the metal wire. 3. The friction stir welding apparatus according to claim 2, wherein the metal wire is an aluminum alloy material having substantially the same hardness as the object to be welded. 4. The friction stirrer according to claim 2, wherein the feeding means has a pair of rollers for holding the metal wire, and continuously feeds the metal wire by rotating the roller. Joining equipment. 5. The friction stir welding apparatus according to claim 4, wherein an insertion hole into which the metal wire is inserted is formed, and a guide member for guiding the metal wire is provided immediately after the roller of the feeding means. . 6. A linear moving member having a through hole for linearly moving relative to the rotor in the direction of the rotation axis and having a metal wire inserted therethrough, wherein the rotor is provided along the rotation axis. A guide hole that penetrates and guides the metal wire, and a recess that is connected to the guide hole and into which the distal end of the rectilinear moving member is displaceably inserted is formed, and an end face of the rectilinear member inserted into the recess, The friction stir welding apparatus according to any one of claims 2 to 5, wherein a coil spring through which the metal wire is inserted is provided between the bottom and the bottom of the place.