JP2010036247A - Friction stir welding apparatus and friction stir welding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a friction stir welding apparatus and a friction stir welding method capable of obtaining a desired energy efficiency. <P>SOLUTION: In the friction stir welding apparatus 1, a rotary tool 2 is rotated by a rotary motor so that a heat generation by the rotary tool 2 becomes a prescribed heat generation enabling welding, and simultaneously the tip end side of the rotary tool 2 is thrusted into an abutted part between outer panels. Then, the rotary tool 2 is pressurized so that the surface pressure of the rotary tool 2 so thrusted becomes a prescribed surface pressure enabling welding, and concurrently, the rotary tool 2 is moved along the abutted portion by a displacing motor. Here, the rotary tool 2 is configured to include a shoulder part 8 showing a columnar shape, and the shoulder diameter D is set on the basis of consumable electricity of the rotary motor and the displacing motor. Accordingly, by using a relation in which power consumption decreases with reduction in the shoulder diameter D, a desired energy efficiency can be obtained. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a friction stir welding apparatus and a friction stir welding method for joining metal materials together.

Conventionally, Friction Stir Welding (FSW) is known as a method for joining metal materials. In the friction stir welding apparatus that performs this friction stir welding, the rotary tool has a shoulder portion that has a cylindrical shape (see, for example, Patent Document 1).
JP-A-9-508073

  Here, when joining metal materials using the friction stir welding apparatus as described above, first, while rotating the rotary tool with the rotating means, the tip side of the rotary tool is pushed into the contact portion between the metal materials. . At this time, the rotary tool is rotated so that the heat generation amount becomes a predetermined heat generation amount that can be joined. And while pressing the said rotary tool so that the surface pressure of a rotary tool may become the predetermined surface pressure which can be joined, this rotary tool is moved along a contact part by a moving means. As a result, the frictional heat generated by the rotation of the rotary tool is used to plastically flow the contact portion, and the metal materials are joined to each other.

  However, in the friction stir welding apparatus as described above, for example, when the melting point of the metal material to be joined is high, the load on the rotating means and the moving means increases depending on the case, and the power consumption of these rotating means and the moving means is increased. May increase. Therefore, there is a possibility that desired energy efficiency cannot be obtained.

  Then, this invention makes it a subject to provide the friction stir welding apparatus and friction stir welding method which can obtain desired energy efficiency.

  In order to solve the above-mentioned problems, the present inventors have made extensive studies, and as a result, have obtained the following knowledge regarding the outer diameter (hereinafter referred to as “shoulder diameter”) of the front end surface of the shoulder portion.

  That is, when the shoulder diameter is reduced, the area of the tip end surface of the shoulder portion is reduced, so that the bonding load pressed to keep the surface pressure of the rotary tool at a predetermined surface pressure is reduced. Therefore, the load on the moving means and the rotating means is reduced according to the reduction in the bonding load. On the other hand, when the area of the front end surface of the shoulder portion is reduced, the amount of heat generated by friction is reduced, so that the number of rotations of the rotary tool is increased to keep the amount of heat generated at a predetermined amount of heat. Therefore, the load on the rotating means increases as the rotational speed increases. In this regard, the present inventors have intensively studied, and in the rotating means, the contribution of the reduction in the joint load is greater than the increase in the number of rotations. Therefore, if the area of the front end surface of the shoulder portion is reduced, the load is reduced as a result. I found out. That is, when the shoulder diameter is reduced, the load on the moving unit and the rotating unit is reduced, and the power consumption of these units is reduced.

  Accordingly, the present inventors have conceived that it becomes possible to obtain desired energy efficiency by paying attention to the shoulder diameter, and the present invention has been completed. That is, the friction stir welding apparatus according to the present invention pushes the distal end side of the rotary tool into the contact portion between the metal materials while rotating the rotary tool, and moves the rotary tool along the contact portion. A friction stir welding apparatus for joining metal materials, a pressing means for pressing the rotary tool so that the surface pressure of the rotary tool becomes a predetermined surface pressure that can be joined, and a predetermined heat generation amount that the heat generated by the rotary tool can be joined A rotating means for rotating the rotating tool so that the rotating tool is moved, and a moving means for moving the rotating tool along the contact portion. The rotating tool includes a shoulder portion having a cylindrical shape. The outer diameter of the distal end surface is set based on the power consumption of the rotating means and the moving means.

  According to this friction stir welding apparatus, the shoulder diameter is set based on the power consumption of the rotating means and the moving means (hereinafter simply referred to as “power consumption”). Therefore, it is possible to obtain desired energy efficiency by utilizing the above relationship that the amount of power consumption decreases as the shoulder diameter is reduced.

The rotating tool further includes a probe portion that is provided at the center of the distal end surface of the shoulder portion and has a cylindrical shape. The outer diameter of the distal end surface of the shoulder portion is the square of the outer diameter of the distal end surface of the probe portion. It is preferable that the ratio satisfies the following formula (1).
D ² / d ² <6 (1)
Where D: outer diameter of the tip surface of the shoulder portion d: outer diameter of the tip surface of the probe portion

  In this case, it is possible to reduce power consumption and obtain high energy efficiency. This is because it is found that the power consumption is significantly reduced when the square of the shoulder diameter is smaller than 6 times the square of the probe diameter.

Here, it is preferable that a square ratio of the outer diameter of the distal end surface of the shoulder portion with respect to the outer diameter of the distal end surface of the probe portion satisfies the following formula (2).
D ² : d ² = 4: 1 (2)
Where D: outer diameter of the tip surface of the shoulder portion d: outer diameter of the tip surface of the probe portion

  In this case, the shoulder diameter can be minimized while suppressing poor bonding. This is because when the square of the shoulder diameter is smaller than three times the square of the probe diameter, the function of the front end surface of the shoulder part, that is, the function of holding the metal material stirred and plastically flowed by the probe part. This is because it is difficult to sufficiently exhibit the above, and there is a possibility that a bonding failure may occur. Therefore, when satisfy | filling said Formula (2), power consumption will be reduced further from the said relationship that power consumption will reduce as a shoulder diameter is made small.

  Moreover, the outer diameter of the front end surface of the shoulder part may be specifically larger than 10 mm and smaller than 15 mm.

  Moreover, it is preferable that a shoulder part has a chamfering part which chamfers the front end side peripheral part, and a chamfering part demarcates the outer diameter of the front end surface of a shoulder part. In this case, with a portion other than the chamfered portion in the shoulder portion, a decrease in strength of the shoulder portion can be suppressed, and breakage of the rotary tool can be prevented.

  Moreover, the friction stir welding method according to the present invention is characterized in that metal materials are joined together using the friction stir welding apparatus.

  Also in this friction stir welding method, it is possible to obtain desired energy efficiency by utilizing the above relationship that the power consumption is reduced as the shoulder diameter is reduced.

  According to the present invention, desired energy efficiency can be obtained.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same or equivalent elements will be denoted by the same reference numerals, and redundant description will be omitted.

  FIG. 1 is a schematic perspective view showing a friction stir welding apparatus according to an embodiment of the present invention. As shown in FIG. 1, the friction stir welding apparatus 1 according to the present embodiment joins the outer plates 10 a and 10 b (metal materials) that are butted against each other along the butted portion (contact portion) L. Is. Here, the friction stir welding apparatus 1 is a load control system.

  The outer plates 10a and 10b are plate members made of a steel material which is a high melting point material, and are adopted for railway vehicles and the like. Here, the outer plates 10a and 10b are made of austenitic stainless steel, and the thickness thereof is about several millimeters.

  The friction stir welding apparatus 1 includes a rotary tool 2 and a tool holder 3. The rotary tool 2 is pushed into the butted portion L and rotated. The rotary tool 2 includes a shoulder portion 8 that has a cylindrical shape, and a probe portion 9 that is provided at the center of the distal end surface 8a of the shoulder portion 8 and has a cylindrical shape (details will be described later). .

  The tool holder 3 has a substantially cylindrical shape formed of a ductile material such as metal. The tool holder 3 has the upper end of the rotary tool 2 inserted into the lower end thereof. Thereby, the rotary tool 2 is gripped by the tool holder 3.

  Further, the friction stir welding apparatus 1 includes a rotation motor (rotation means) 4, a movement motor (movement means) 5, and a pressing device (pressing means) 6. The rotary motor 4 is a motor that rotates the rotary tool 2 around an axis (so-called spindle axis) G of the rotary tool 2. The moving motor 5 is a motor that moves the rotary tool 2 along the abutting portion L. The pressing device 6 applies a joining load as a pressing force to the rotary tool 2 and, for example, a Z-axis cylinder is used. A controller 7 for controlling the operation is connected to the rotary motor 4, the moving motor 5 and the pressing device 6.

  The controller 7 controls the pressing device 6 to control the bonding load so that the surface pressure of the pressed rotary tool 2 becomes a predetermined surface pressure that can be bonded. The controller 7 controls the rotation motor 4 to control the rotation speed of the rotary tool 2 so that the heat generation amount by the rotary tool 2 becomes a predetermined heat generation amount that can be joined. Furthermore, the controller 7 controls the moving motor 5 to control the speed at which the rotary tool 2 is moved along the butted portion L (hereinafter referred to as “joining speed”).

  When the outer plates 10a and 10b are bonded to each other by the friction stir welding apparatus 1 described above, first, the outer plates 10a and 10b are mounted on the mounting portion 11, and the end surfaces of the outer plates 10a and 10b are brought into contact with each other. (S1 in FIG. 2).

  Subsequently, while rotating the rotary tool 2, the distal end side of the rotary tool 2 is pushed into one end of the abutting portion L of the outer plates 10a and 10b (S2). At this time, the rotation speed of the rotary tool 2 is set to a rotation speed at which the heat generation amount by the rotary tool 2 becomes a predetermined heat generation amount (a heat generation amount capable of joining the outer plates 10a and 10b). Then, the rotary tool 2 is pressed with a joining load such that the surface pressure becomes a predetermined surface pressure (surface pressure capable of joining the outer plates 10a and 10b) (S3).

  Thereby, the frictional heat generated between the rotating rotary tool 2 and the outer plates 10a and 10b is used, and plastic flow occurs. Specifically, the outer plates 10a and 10b are stirred by the probe unit 9 and flow so as to overflow to the rotating tool 2 side. At the same time, the fluidized outer plates 10 a and 10 b are further agitated while being fastened by the front end surface 8 a of the shoulder portion 8. As a result, a joint portion W that joins the outer plates 10a and 10b to each other is formed.

  Then, the rotary tool 2 is moved along the abutting portion L to the other end of the abutting portion L with the tilting angle θ (for example, 3 °) inclined toward the front side with respect to the moving direction (S4). . As a result, the joint W is formed from one end of the butted portion L to the other end. Thereafter, the rotary tool 2 is lifted from the outer plates 10a and 10b, and the process is terminated.

  Next, the rotary tool 2 described above will be described in detail.

  FIG. 3 is an enlarged cross-sectional view showing the distal end side of the rotary tool in the friction stir welding apparatus of FIG. As shown in FIG. 3, the rotary tool 2 is a tool for frictionally stirring the outer plates 10 a and 10 b, and the tip side (the lower side in the drawing) is pushed into the abutting portion L. As described above, the rotary tool 2 includes the shoulder portion 8 and the probe portion 9.

  The front end surface 8a of the shoulder portion 8 is an inclined surface that is recessed toward the center as preferable for securing the fluidized outer plates 10a and 10b. The shoulder portion 8 has a chamfered portion K formed by chamfering a corner portion of the distal end side peripheral edge portion. The chamfered portion K defines an outer diameter (hereinafter referred to as “shoulder diameter”) D of the distal end surface 8 a of the shoulder portion 8.

  The probe portion 9 has a columnar shape smaller than the shoulder diameter D, and is provided coaxially on the distal end surface 8 a of the shoulder portion 8. The outer diameter (hereinafter referred to as “probe diameter”) d of the distal end surface 9a of the probe portion 9 is uniquely set based on the strength of the probe portion 9 and the plate thickness of the outer plates 10a and 10b. In this case, the probe diameter d is set to 6 mm with emphasis on strength. Moreover, the height of the probe part 9 is set based on the shoulder diameter D, and is 1.3 mm here. As a result, when the rotary tool 2 is tilted at the tilt angle θ (in the case of S4), it is possible to prevent the shoulder portion 8 from strongly interfering with the outer plates 10a and 10b. For example, the surface pressure of the rotary tool 2 is reduced. Non-uniformity can be suppressed.

  By the way, in the friction stir welding apparatus 1, since the area of the front end surface 8a of the shoulder portion 8 decreases as the shoulder diameter D decreases, the surface pressure of the rotary tool 2 (surface pressure of the front end surfaces 8a and 9a). ) Is reduced to maintain a predetermined surface pressure, and the load on each of the motors 4 and 5 is reduced in accordance with the reduction of the bonding load. On the other hand, when the area of the front end surface 8a of the shoulder portion 8 is reduced, the amount of heat generated by friction is reduced. Therefore, the number of rotations of the rotary tool 2 is increased to maintain a predetermined amount of heat generation. The load on is increased.

  In this regard, the present inventors have made extensive studies, and in the rotary motor 2, the contribution of the reduction in the joint load is greater than the increase in the number of revolutions. Therefore, when the area of the tip surface 8 a is reduced, the load is reduced as a result. I found out. That is, as the shoulder diameter D is reduced, the load on the motors 4 and 5 is reduced, and the power consumption of both the motors 4 and 5 is reduced.

  FIG. 4A is a graph showing an example of the relationship between the current value of the rotary motor and the joining speed, and FIG. 4B is a graph showing an example of the relationship between the current value of the moving motor and the joining speed. In each figure, D12 and D15 are different data for the rotary tool 2 to be used, and the number after the symbol D means the size (mm) of the shoulder diameter D. The probe diameter d of each rotary tool 2 at D12 and D15 is constant (here, 6 mm). In D12 and D15, the joining conditions are such that the same beat appearance can be obtained. Here, the rotational speed is set to 900 rpm in D12, and the rotational speed is set to 600 rpm in D15.

  As shown in FIG. 4, when the shoulder diameter D is reduced, the relationship that the current value and thus the power consumption is reduced can be confirmed. Specifically, as shown in FIG. 4A, in the range of the joining speed of 300 mm / min to 600 mm / min, in D15, as the joining speed increases, the current value of the rotary motor 4 rapidly increases and becomes a large value. Is shown. In D12, a small value is maintained regardless of the bonding speed. Further, as shown in FIG. 4B, the current value of the moving motor 5 has the same tendency as that of the rotary motor 4.

  For example, when the joining speed is 600 mm / min, “the current value of the rotary motor 4 is 51 A and the current value of the moving motor 5 is 3.8 A at D 15”, whereas “the current value of the rotary motor 4 is“ D 12. The current value is 21 A, and the current value of the moving motor 5 is 2.1 A ”. That is, when the shoulder diameter D is 4/5, the current value of the rotary motor 4 is reduced by about 60% and the current value of the moving motor 5 is reduced by about 45%. Thus, it can be seen that when the shoulder diameter D is small, the current values of the motors 4 and 5 are low.

  Therefore, in the rotary tool 2 of the present embodiment, the shoulder diameter D is set based on the power consumption in order to obtain high energy efficiency based on the above relationship between the shoulder diameter D and the power consumption. , 12 mm. Therefore, in this embodiment, desired energy efficiency can be obtained by suitably utilizing the above relationship between the shoulder diameter D and the power consumption.

  As shown in FIG. 4A, in D15, when the joining speed is 600 mm / min, the current value exceeds the upper limit, whereas in D12 of this embodiment, the joining speed is 1500 mm. Even if / min, the current value can be set to a predetermined value (in this case, 40 mA) or less. Thereby, in this embodiment, even if it speeds up joining speed, the electric power consumption of each motor 4 and 5 can be maintained low. In other words, in the present embodiment, the shoulder diameter D is set such that the maximum value of the power consumption related to the joining speed is equal to or less than a predetermined value. As a result, the maximum joining speed can be improved.

In the present embodiment, as described above, the shoulder diameter D is 12 mm, and the square ratio with respect to the probe diameter d satisfies the following expression (1). Thereby, it becomes possible to reduce power consumption and to obtain high energy efficiency. As shown in FIG. 4, for D12 where the square of the shoulder diameter D is smaller than 6 times the square of the probe diameter d, the square of the shoulder diameter D is 6 times or more of the square of the probe diameter d. This is because the power consumption is significantly reduced. In the present embodiment, the shoulder diameter D that satisfies the following formula (1) is 14.7 mm or less.
D ² / d ² <6 (1)
Where D: shoulder diameter, d: probe diameter

  Here, if the square of the shoulder diameter D is smaller than three times the square of the probe diameter d, there is a risk that poor bonding is likely to occur. This is due to the following reason. That is, the front end surface 8 a of the shoulder portion 8 has a function of keeping the outer plates 10 a and 10 b plastically flowing by the probe portion 9 from being diffused. This is because if the square of the shoulder diameter D is smaller than three times the square of the probe diameter d, it is considered that such a function is not sufficiently exhibited.

In this regard, in the present embodiment, as described above, the shoulder diameter D is 12 mm, and the square ratio with respect to the probe diameter d satisfies the following expression (2). In other words, the shoulder diameter D of the present embodiment is minimized while suppressing poor bonding. As a result, while achieving good friction stir welding, the power consumption can be further reduced from the above relationship between the shoulder diameter D and the power consumption (see FIG. 4), and the shoulder diameter D is optimized with respect to energy efficiency. It becomes possible to do. Therefore, the running cost can be reduced, the electric capacity of the primary power source (breaker or the like) to be connected can be suppressed, and the installation cost can be reduced.
D ² : d ² = 4: 1 (2)
Where D: shoulder diameter, d: probe diameter

FIG. 5 is a table showing an example of the determination result of the joining state. As shown in FIG. 5, when the probe diameter d is constant at 6 mm, when the shoulder diameter D is 12 mm (when D ² : d ² = 4: 1), the bonding state is good (◯ in the figure). It became. Further, when the shoulder diameter D was 10 mm, which was smaller than 12 mm, the joining state became uneven and became defective (x in the figure). Thereby, when the square of the shoulder diameter D is four times the square of the probe diameter d (when larger than three times), it can be confirmed that the shoulder diameter D is minimized while suppressing poor bonding. . The reason why the shoulder diameter D and the probe diameter d are in a square relationship in the above formulas (1) and (2) is considered that the above function of the distal end surface 8a is related to the area.

Incidentally, in this embodiment, it can be said that the shoulder diameter D preferably satisfies the following expression (3) in consideration of the above expression (1) and the function of the probe unit 9 described above. That is, the shoulder diameter D is preferably larger than 10 mm and smaller than 15 mm. More specifically, the shoulder diameter D is preferably larger than 10.4 mm and not larger than 14.7 mm.
3 <D ² / d ² <6 (3)

  FIG. 6A is a graph showing an example of the time change of the current value in the rotary motor, and FIG. 6B is a graph showing an example of the time change of the current value in the mobile motor. In each figure, the joining speed is 600 mm / min. As shown in FIG. 6A, when starting to move after inserting the rotary tool, the current value of the rotary motor 4 greatly increases at D15, but does not increase greatly at D12 of the present embodiment. Thereby, in this embodiment, the load with respect to the rotary tool 2 can be reduced, and breakage of the rotary tool 2 can be prevented.

  FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 1 in the outer plate after friction stir welding. FIG. 7A shows the outer plates 10a and 10b subjected to friction stir welding with the rotary tool 2 (shoulder diameter 12 mm) of this embodiment, and FIG. 7B shows a conventional rotary tool (shoulder diameter 15 mm). The outer plates 10a and 10b subjected to friction stir welding are shown. As shown in FIGS. 7A and 7B, in the friction stir welding by the conventional rotary tool, the heat input range to the upper surface of the joint W is excessive, so that the angular deformation and the distortion of the joining line increase. . On the other hand, in the friction stir welding by the rotary tool 2 of the present embodiment, it can be seen that the heat input range to the upper surface of the joint W is appropriate and a good joint W is formed.

  In the present embodiment, as described above, the shoulder portion 8 includes the chamfered portion K formed by chamfering the distal end side peripheral edge portion, and the chamfered portion K defines the shoulder diameter D. Thereby, even if the shoulder diameter D is reduced, for example, the shaft diameter of the shoulder portion 8 other than the chamfered portion K can be kept relatively large. Therefore, it is possible to suppress a decrease in the strength of the shoulder portion 8 and prevent breakage of the rotary tool 2 at portions other than the chamfered portion K. Further, in this case, since the above-described effect can be obtained only by providing the chamfered portion K, it can be said that the versatility is high.

  Further, in the present embodiment, as described above, the outer plates 10a and 10b, which are high melting point steel materials, are friction stir welded with desired energy efficiency and consequently high energy efficiency. Therefore, this embodiment is particularly effective.

  FIG. 8 is a graph showing an example of the relationship between the pressure at which the rotary tool is pressed by the pressing device and the joining speed. As shown in FIG. 8, it can be seen that when the shoulder diameter D is reduced, the required bonding load (pressure) is reduced. Therefore, the rigidity of the rotary tool 2 can be lowered, and the mass of the friction stir welding apparatus 1 can be reduced.

  In the present embodiment, as described above, the shoulder diameter D of the rotary tool 2 satisfies the above formula (2), and is the minimum value within a range where no bonding failure occurs. Therefore, since the rotation speed of the rotary tool 2 is increased in order to secure a predetermined heat generation amount, the agitation by the probe unit 9 can be improved, and the joining state can be further improved.

  Incidentally, the height of the probe portion 9 of the rotary tool 2 of the present embodiment is 1.3 mm, whereas the height of the probe portion 9 of the conventional rotary tool (shoulder diameter 15 mm) is 1.5 mm. . That is, in this embodiment, the height of the probe unit 9 can be set low. This is because as the shoulder diameter D decreases, the shoulder portion 8 is less likely to interfere with the outer plates 10a and 10b during the movement of the rotary tool 2 (at the time of S4). As a result, the bending strength of the probe portion 9 can be increased and the life can be extended.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. For example, in the above embodiment, the outer plates 10a and 10b, which are steel materials, are friction stir welded. However, for example, a non-ferrous metal material such as an aluminum alloy may be friction stir welded.

  Further, in the above embodiment, the outer plates 10a and 10b are butted against each other (so-called butted joining), but the joining form is not limited, and the outer plates 10a and 10b are overlapped and joined (so-called overlapping). May be joined together).

  FIG. 9 is a cross-sectional view corresponding to FIG. 7 showing the result of friction stir welding of the stacked outer plates. FIG. 9A shows the outer plates 10c and 10d subjected to the friction stir welding by the rotary tool 2 (shoulder diameter 12 mm), and FIG. 9B shows the friction stir welding by the conventional rotary tool (shoulder diameter 15 mm). The outer plates 10c and 10d are shown. As shown in FIGS. 9 (a) and 9 (b), it can be seen that the present invention can also be suitably applied to lap bonding. Further, in the welded portion W (see FIG. 9A) in which the rotary tool 2 is applied to the superposition joining, similarly to the result shown in FIG. 7, the joined portion W (see FIG. 7) formed by the conventional rotary tool. 9 (b)), it can be seen that the heat input range to the upper surface is appropriate and the bonding state is good.

  Further, the above “4: 1”, “cylindrical shape”, and “central portion” include approximately 4: 1, substantially cylindrical shape, and substantially central portion, respectively. For example, variations due to dimensional tolerances, manufacturing errors, etc. Is included.

  In addition, the joining of this invention includes the continuous joining (normal FSW) which forms a junction part continuously along a contact part, and the intermittent joining (spot FSW) which forms a junction part intermittently. . Therefore, the joint of the present invention includes, for example, the butt continuous joint, the butt intermittent joint, the superposed continuous joint, and the superposed intermittent joint in consideration of the relationship between the butt joint and the superposed joint.

It is a schematic perspective view which shows the friction stir welding apparatus which concerns on one Embodiment of this invention. It is a flowchart which shows the procedure of the method of joining outer plates with the friction stir welding apparatus of FIG. It is an expanded sectional view which shows the front end side of the rotary tool in the friction stir welding apparatus of FIG. (A) is a graph which shows an example of the relationship between the electric current value of a rotary motor, and joining speed, (b) is a graph which shows an example of the relationship between the electric current value of a moving motor, and joining speed. It is a table | surface which shows an example of the determination result of a joining state. (A) is a graph which shows an example of the time change of the electric current value in a rotary motor, (b) is a graph which shows an example of the time change of the electric current value in a movement motor. It is sectional drawing which follows the VII-VII line of FIG. It is a graph which shows an example of the relationship between the pressure loaded on a rotary tool with a pressing device, and joining speed. It is sectional drawing corresponding to FIG. 7 which shows the result of carrying out friction stir welding of the laminated | stacked outer plate | board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Friction stir welding apparatus, 2 ... Rotation tool, 4 ... Rotation motor (rotation means), 5 ... Movement motor (movement means), 6 ... Pressing device (pressing means), 8 ... Shoulder part, 8a ... Tip surface, 9 ... probe part, 9a ... tip surface, 10a, 10b ... outer plate (metal material), K ... chamfering part, L ... butting part (contact part), D ... shoulder diameter, d ... probe diameter.

Claims (6)

Friction stir welding that joins the metal materials by pushing the tip side of the rotary tool into the abutting portion between the metal materials while rotating the rotating tool and moving the rotating tool along the abutting portion A device,
A pressing means for pressing the rotating tool so that the surface pressure of the rotating tool becomes a predetermined surface pressure that can be joined;
Rotating means for rotating the rotating tool so that the amount of heat generated by the rotating tool is a predetermined amount of heat that can be joined;
Moving means for moving the rotating tool along the contact portion,
The rotating tool includes a shoulder portion having a cylindrical shape,
The outer diameter of the front end surface of the shoulder part is set based on the power consumption of the rotating means and the moving means. The rotating tool is further configured to include a probe portion that is provided at the center portion of the front end surface of the shoulder portion and has a cylindrical shape,
2. The friction stir welding apparatus according to claim 1, wherein a square ratio of the outer diameter of the front end surface of the shoulder portion to the outer diameter of the front end surface of the probe portion satisfies the following expression (1).
D ² / d ² <6 (1)
Where D: outer diameter of the tip surface of the shoulder portion d: outer diameter of the tip surface of the probe portion 3. The friction stir welding apparatus according to claim 2, wherein a square ratio of the outer diameter of the front end surface of the shoulder portion to the outer diameter of the front end surface of the probe portion satisfies the following formula (2).
D ² : d ² = 4: 1 (2)
Where D: outer diameter of the tip surface of the shoulder portion d: outer diameter of the tip surface of the probe portion   The friction stir welding apparatus according to any one of claims 1 to 3, wherein an outer diameter of a front end surface of the shoulder portion is larger than 10 mm and smaller than 15 mm. The shoulder portion has a chamfered portion formed by chamfering a distal end side peripheral portion thereof,
The friction stir welding apparatus according to any one of claims 1 to 4, wherein the chamfered portion defines an outer diameter of a front end surface of the shoulder portion.   A friction stir welding method comprising joining metal materials using the friction stir welding apparatus according to any one of claims 1 to 5.

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