JP2003334671A - Friction stir welding method, its device, and welding member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily judge whether the whole of a welding interface is uniformly softened and uniformly welded or not. <P>SOLUTION: Two sheets of members to be welded 1, 2 are friction stir welded by using a rotary tool 20 having a protrusion part 21 at its tip and rotatable by making the axis core of the protrusion part 21 as the rotation center and a receiving base 30 in which a circumference shaped recessed streak part 33 as a detection means to detect pressure receiving force on a pressure receiving face 31 on which pressing force of the rotary tool 20 acts is provided around the rotation center. The welding quality is judged by comparison of the molding extent of a molding protrusion part in the circumferential direction since the molding protrusion part is molded on the surface of the member 1 to be welded brought into contact with the pressure receiving face 31 by the circumference shaped recessed streak part 33. <P>COPYRIGHT: (C)2004,JPO

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 method and apparatus, and a welding member. INDUSTRIAL APPLICATION This invention can be utilized suitably, for example, when joining board materials made from aluminum alloys.

[0002]

2. Description of the Related Art Friction stir welding has been known as one of the techniques for joining members to be joined such as plates in a state of being superposed.

For example, Japanese Patent Laid-Open No. 2001-314963 discloses friction stir welding using a rotary tool having a protrusion at its tip and rotatable about an axis of the protrusion as a rotation center, and a pedestal. It is disclosed. In this friction stir welding, a plurality of members to be welded are superposed and disposed on a receiving table, and then the rotary tool is pressed against the members to be welded disposed on the receiving table while rotating the rotary tool so that the protrusion is formed. The materials of the members to be joined are agitated by friction in a non-molten state by joining the members to be joined together.

[0004]

By the way, in the above friction stir welding, if any of the rotary tool, the pedestal and the member to be welded is not frictionally maintained due to a setting error or the like, the friction stir welding is performed. There is. For example, when a rotary tool that is obliquely inclined is pressed against a member to be welded horizontally placed on a pedestal, the pressing direction of the rotary tool to the member to be welded is inclined and the rotating tool is pressed against the member to be welded. The pressure acts at an angle. Then, the bonding interface of the members to be bonded is unevenly pressed to be in an unevenly softened state, resulting in defective bonding.

However, even if such a joining failure occurs, no significant difference is observed in the appearance of the joining member as compared with the case of a good joining state.

Therefore, in the conventional friction stir welding, there is a problem that it is not possible to judge from the appearance of the joining member whether or not the entire joining interface is softened uniformly and is joined uniformly.

The present invention has been made in view of the above circumstances, and in friction stir welding, it is possible to easily judge whether or not the entire joint interface is softened uniformly and is joined uniformly. It is a technical problem to be solved to provide a joining method, an apparatus therefor, and a joining member.

[0008]

A friction stir welding method of the present invention for solving the above-mentioned problems has a rotary tool having a projection at its tip and rotatable about an axis of the projection as a rotation center, and the rotary tool. A plurality of members to be joined are superposed on each other by using a receiving table on the pressure receiving surface on which the pressing force of the tool acts, for detecting the receiving pressure, which is arranged substantially evenly in the circumferential direction around the rotation center. An arranging step of arranging the pedestal on the pedestal, and pressing the rotary tool against the member to be bonded arranged on the pedestal while rotating the rotary tool so that the protrusion enters the inside of the member to be bonded, It is characterized in that a joining step of joining the members to be joined together by stirring the materials of the members to be joined by friction in a non-molten state by friction.

In a preferred aspect, the detection means is a concave portion or a convex portion that is concavely or convexly provided on the pressure receiving surface, and in the joining step, the surface of the member to be joined that abuts the pressure receiving surface, A molding convex portion or a molding concave portion is molded by the concave portion or the convex portion.

In a preferred mode, the detection means is a pressure sensor capable of detecting the received pressure.

A friction stir welding apparatus of the present invention which solves the above-mentioned problems has a pedestal on which a plurality of members to be welded are superposed and provided with a projection at the tip, and the axis of the projection is rotated. In a friction stir welding apparatus provided with a rotary tool that is pressed against the members to be welded arranged on the pedestal while being rotated as a center, in the pedestal, a pressure-receiving force on which the pressing force of the rotary tool acts. It is characterized in that the surface is provided with detection means for detecting the received pressure substantially evenly in the circumferential direction around the rotation center.

In a preferred mode, the detecting means is a concave portion or a convex portion which is provided in a concave shape or a convex shape in the pressure receiving surface.

In a preferred mode, the detection means is a pressure sensor capable of detecting the received pressure.

In the friction stir welding, the pressing force from the rotary tool acts on the pressure receiving surface of the pedestal through the members to be welded. At this time, if the pressing force is uniformly applied to the entire pressure receiving surface of the pedestal, the pressing force is evenly applied to the entire joint interface between the members to be joined, resulting in a uniform softened state. ,
Bonded evenly. On the other hand, if the pressing force does not act uniformly on the pressure receiving surface of the pedestal, the joint interface will be in a non-uniform softened state, resulting in defective joints.

In the stir welding method and the apparatus therefor according to the present invention, the detection means for detecting the pressure receiving force is provided on the pressure receiving surface of the pedestal on which the pressing force of the rotating tool acts, in the circumferential direction around the rotation center of the rotating tool. Are arranged substantially evenly. Therefore, it is possible to judge the quality of the joint by comparing the received pressure detected by using this detecting means in the circumferential direction around the rotation center.

That is, if the pressure received by the detecting means is uniform in the circumferential direction around the center of rotation, the pressing force from the rotary tool acts evenly on the joining interface, and the joining interface It can be judged that the whole is in a uniform and proper softened state and is in a good joined state.

On the other hand, if the received pressure detected by the detecting means is not uniform in the circumferential direction around the rotation center,
It can be determined that the pressing force from the rotary tool acts non-uniformly even at the above-mentioned joining interface to cause joining failure. For example, when the pressure received on one side with respect to the center of rotation is larger than that on the other side, the joining strength on the other side is insufficient as compared to the one side, and it can be determined that a joining failure has occurred.

In the case where the detecting means is a concave portion or a convex portion concavely or convexly provided on the pressure receiving surface, the surface of the member to be joined which comes into contact with the pressure receiving surface of the pedestal in the joining step,
A molding convex portion or a molding concave portion is molded by the concave portion or the convex portion. Therefore, by comparing the forming degree of the forming convex portion or the forming concave portion in the circumferential direction around the rotation center, it is possible to easily judge visually whether the joining is good or bad.

That is, if the molding convex portion or the molding concave portion is uniformly molded in the circumferential direction around the rotation center, it can be determined that the bonding interface is in a good bonding state. On the other hand, when the molding projections or molding recesses are molded unevenly in the circumferential direction around the rotation center, for example, the molding projections or molding recesses are molded only on one side of the rotation center and the other side. Then, in the case where it is not molded, it can be determined that the bonding strength on the other side is insufficient as compared with that on the one side, and a bonding failure has occurred.

When the detecting means is a pressure sensor capable of detecting the pressure receiving force, the pressure receiving force detected by the pressure sensor is compared in the circumferential direction around the rotation center to determine the quality of the joining. You can judge.

That is, if the pressure received by the pressure sensor is uniform in the circumferential direction around the center of rotation, it can be determined that the joining interface is in a good joining state. on the other hand,
When the pressure receiving force detected by the pressure sensor is non-uniform in the circumferential direction around the rotation center, for example, when the pressure receiving force on one side of the rotation center is larger than that on the other side, the bonding strength at the other side Is insufficient as compared with one side, and it can be determined that a defective joint has occurred.

The joining member of the present invention for solving the above-mentioned problems is
A rotary tool having a protrusion at its tip and rotatable about an axis of the protrusion as a rotation center, and a concave portion or a convex portion on a pressure receiving surface on which the pressing force of the rotary tool acts in a circumferential direction around the rotation center. Using a pedestal that is substantially evenly recessed or convexly provided, presses the protrusion while rotating the rotating tool at the joining point of a plurality of members to be joined that are arranged in an overlapping manner on the pedestal. A joining member obtained by friction stir welding in which the materials of the members to be joined are agitated by friction in a non-molten state by friction to join the members to be joined, wherein the recesses are formed. Alternatively, the molding convex portion or the molding concave portion formed by the convex portion is provided substantially evenly in the circumferential direction around the joining point.

In this joining member, due to the concave portion or the convex portion provided on the pressure receiving surface of the pedestal, the surface of the member to be joined which has been in contact with the pressure receiving surface of the pedestal when it is arranged on the pedestal,
The forming protrusions or forming recesses are formed substantially evenly in the circumferential direction. In the joining member in which the forming projections or forming recesses are formed substantially evenly in the circumferential direction, the pressing force of the rotating tool acts uniformly on the joining interface during friction stir welding, and thus a uniform joining state is obtained. ing. Therefore, the joining member according to the present invention has high joining strength reliability.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION In a friction stir welding method and apparatus according to the present invention, a rotary tool having a protrusion at its tip and rotatable about the axis of the protrusion as a rotation center, and a pusher for the rotary tool. The pressure receiving surface on which the pressure acts uses a pedestal in which the detecting means for detecting the pressure receiving is disposed substantially evenly in the circumferential direction around the rotation center. Then, by performing the disposing step and the joining step, friction stir welding is performed in a state where at least two members to be joined are superposed.

In the arranging step, a plurality of members to be joined are stacked and arranged on the pedestal. The number of members to be joined may be two, or three or more in some cases.

In the joining step, the rotary tool is pressed against the member to be joined arranged on the pedestal while rotating the rotary tool to allow the protrusion to enter the inside of the member to be joined.
The materials of the members to be joined are agitated by friction in a non-molten state to join the members to be joined.

In this joining step, a rotary tool that rotates at a predetermined rotation speed is pressed against the members to be bonded with a predetermined pressing force. As a result, the rotary tool having a hardness higher than that of the members to be joined is adopted as will be described later, so that the protrusion of the rotary tool enters the inside of the members to be joined. At this time,
Since friction occurs between the member to be welded that contacts the rotating tool and the rotating tool, the frictional heat softens the material of the member to be welded, and as the softening progresses, the protrusion of the rotating tool is welded. Enter the inside of the member. Further, the softened material of the members to be welded is agitated in the non-melted state in the rotation direction of the rotary tool, the length (axial center) direction of the protrusion, and the like. Then, the frictional heat generated by the contact with the projection of the rotary tool causes the material of the member to be welded closest to the cradle side to be softened at the bonding interface and stirred until the material is agitated in the rotation direction or the like. . In this way, at the joining interface between the members to be joined, the materials of the members to be joined are softened in a non-melted state and stirred, whereby the members to be joined can be joined together.

The material forming the rotary tool and the pedestal is not particularly limited as long as it is a material having a hardness higher than that of the members to be joined, but it is preferable to use a material having high wear resistance, for example, wear resistance. High steel materials (such as cemented carbide) can be adopted. The material of the members to be joined is not particularly limited as long as it has a lower hardness than the rotary tool and the pedestal, and may be copper, magnesium, iron or an alloy thereof, in addition to aluminum or an aluminum alloy.

The shape of the rotary tool, the protrusion of the rotary tool, and the pedestal may be cylindrical or the like.
The sizes of the rotary tool, the protrusion, and the pedestal are not particularly limited, but for example, the outer diameter of the rotary tool is 5 to 30 mm.
The outer diameter of the protrusion of the rotary tool can be about 2 to 10 mm, and the outer diameter of the pedestal is equal to or larger than the outer diameter of the rotary tool.

Further, the protrusion length (axial length) of the protrusion of the rotary tool is the surface of the member to be welded closest to the rotary tool among the plurality of members to be welded arranged on the pedestal. To the joint interface closest to the pedestal side (when two members to be joined are superposed and joined, the value of the depth D is the thickness T of the joined member on the rotary tool side). ),
It is preferably 1.0 times or more.

Such a rotary tool can be rotatably attached to an arm or the like of an articulated robot so that the rotary tool can be moved in the X-axis and Y-axis directions to a plurality of respective joint points. Then, in the arm or the like of the articulated robot, a pedestal arranged so as to face the rotary tool, such as a motor as a driving means for rotationally driving the rotary tool, and a distance between the rotary tool and the pedestal are adjusted. It is possible to attach an actuator or the like as a pressing force adjusting means for adjusting the pressing force of the rotary tool on the members to be joined.

Further, the rotational speed of the rotary tool and the pressing force against the members to be welded can be appropriately set within a range in which good friction stir welding can be performed according to the hardness of the materials of the members to be welded, the required joining strength, and the like. is there. For example, the rotation speed of the rotary tool can be set to about 500 to 4000 rpm, and the pressing force of the rotary tool on the members to be joined can be set to about 50 to 600 kgf. Incidentally, if the rotation speed of the rotary tool is too slow, the softening and stirring of the material of the members to be welded will be insufficient and the joining strength will be insufficient, and even if the rotation speed is too fast, the softened metal to be stirred is Since it cannot follow the rotation, it is not sufficiently stirred and the joint strength becomes insufficient. Further, if the pressing force of the rotary tool is too large, the rotary tool is excessively inserted, so the plate thickness of the members to be bonded on the rotary tool side becomes thin and the bonding strength becomes insufficient, and even if it is too small, friction heat generation will be small. Therefore, the softening of the members to be joined becomes insufficient and the joining strength becomes insufficient.

Here, in the friction stir welding and the apparatus therefor according to the present invention, the detection means for detecting the pressure receiving surface of the pedestal on which the pressing force of the rotary tool acts is substantially in the circumferential direction around the rotation center. The greatest feature is that they are evenly arranged,
As a result, the above-described effects can be obtained.

As the above-mentioned detecting means, it is preferable to use a concave portion or a convex portion which is concave or convex on the pressure receiving surface of the pedestal, or a pressure sensor capable of detecting the pressure received.

In the case where the pressure receiving surface of the pedestal is provided with a concave portion or a convex portion on the pressure receiving surface, the center of rotation is the surface of the member to be contacted by the concave portion or the convex portion in the joining step. A molding convex portion or a molding concave portion is molded around (that is, a joining point where the protrusion of the rotary tool is pressed). Then, in the above-mentioned joining step, if the pressing force of the rotary tool acts uniformly on the joining interface to bring about a uniform joining state, the forming projections or forming recesses are formed substantially evenly in the circumferential direction around the joining point. Therefore, the joining member according to the present invention in which the molding convex portion or the molding concave portion is molded substantially evenly in the circumferential direction around the joining point has high reliability of the joining strength.

The recess or protrusion may be preferably a recess or protrusion extending in the circumferential direction around the center of rotation. Even if the concave portion or the convex portion is a circumferential concave portion or convex portion that continuously extends in the entire circumferential direction around the rotation center, it is intermittent in the circumferential direction around the rotation center. It may be a plurality of arc-shaped recessed ridges or ridges extending. However, in the case of forming a plurality of arc-shaped concave streak portions or convex streak portions, it is necessary that the respective arc-shaped concave streak portions or convex streak portions are arranged substantially evenly in the circumferential direction around the rotation center. Further, the concave portions or convex portions may be a plurality of dot-shaped concave portions or convex portions which are dispersed and arranged substantially uniformly in the circumferential direction around the rotation center.

The pressure sensor is not particularly limited, but a load cell or the like can be used. This pressure sensor is, for example, embedded in the pedestal or attached to the pressure receiving surface of the pedestal so that the pressure sensing portion of the pressure sensor is exposed on the pressure receiving surface and disposed on the pedestal. It is possible to directly contact the members to be joined.

[0038]

EXAMPLES Examples of the present invention will be described below.
A description will be given with reference to the drawings.

(Embodiment 1) In this embodiment, as shown in FIG. 1, a friction stir welding apparatus equipped with a rotary tool 20 and a pedestal 30 is used, and two members 1, 2 to be welded are used. Friction stir welding is performed in a state where they are superposed. Further, the concave portion as the detection means is provided on the pressure receiving surface 31 of the pedestal 30.

The members 1 and 2 to be joined are plate materials (plate thickness 1 mm) made of aluminum alloy.

The rotary tool 20 is made of a cemented carbide having a hardness higher than that of the aluminum alloy forming the members to be joined 1 and 2 and a high wear resistance, and has a columnar shape with an outer diameter of 10 mm. Then, at the tip of the rotary tool 20, there is concentrically formed a protruding portion 21 having a cylindrical shape with an outer diameter of 4 mm and an axial length of 1.3 mm.

The rotary tool 20 is rotatable about the axis C1 (see FIG. 3) of the rotary tool 20 and the protrusion 21. The protrusion length (axial length) of the protrusion 21 is about 1.3 times the depth D (plate thickness of the member 1 to be joined). Therefore, in the joining step described later, the protrusion 21 of the rotary tool 20 penetrates the welded member 2 on the rotary tool 20 side and passes through the joint interface between the welded members 1 and 2, and the tip of the protrusion 21 is About 0.3 to 0.4 mm is inserted into the joined member 1 on the cradle 30 side.

The pedestal 30 is made of a cemented carbide having a hardness higher than that of the aluminum alloy forming the members 1 and 2 to be joined and a high wear resistance, and has a cylindrical shape with an outer diameter of 20 mm. As shown in FIG. 2, the pressure receiving surface 31, which is the upper end surface of the pedestal 30, has a circular recess 32 and a detection provided on the circumference centered around the circular recess 32. A circumferential groove portion 33, which is a concave portion as a means, is provided concentrically with the pedestal 30. The circular recess 32 has a diameter of 3 mm centered on the axis C2 of the pedestal 30.
It has a circular shape and is recessed so that the depth gradually increases from the periphery to the center, and the maximum depth at the center is 0.5 mm. In addition, this circular recess 32
Is the rotary tool 20 and the axis C1 of the protrusion 21, and the pedestal 3
It is provided to confirm that the axis C2 of 0 is coaxial. Further, the circumferential recessed portion 33 is arranged on the circumference centered on the axis C2 of the pedestal 30, and has a constant width (width 1 mm) and a constant depth (depth 0. 5 mm)
It consists of a groove with.

The rotary tool 20 is rotatably attached to an arm of an articulated robot (not shown) so as to be movable in the X-axis and Y-axis directions. In the arm of the articulated robot, a motor as a driving unit that rotationally drives the rotary tool 20, a receiving table 30 concentrically opposed to the rotary tool 20, a rotating tool 20, and the receiving table are provided. An actuator is attached as a pressing force adjusting means for adjusting the interval between the members 30 to adjust the pressing force of the rotary tool 20 against the members 1 and 2 to be joined.

Since the rotary tool 20 and the pedestal 30 are concentrically arranged and friction stir welding is performed, the axis C1 of the rotary tool 20 and the protrusion 21, that is, the rotation center C1 is the pedestal. It coincides with the axis C2 of 30. Therefore, the circumferential groove portion 33 continuously extends in the entire circumferential direction around the rotation center C1 of the rotary tool 20 and the protrusion 21.

By using the rotary tool 20 and the pedestal 30 having the above structure, the following disposing process, joining process and evaluation process are carried out so that the two members 1 and 2 to be joined are superposed. Friction stir welding was performed in this state.

<Arrangement Step> As shown in FIG. 3, the arm of an articulated robot (not shown) is operated, and it is held horizontally by the holding means (not shown) in a superposed state.
The joined members 1 and 2 were placed on the pedestal 30. At this time, the joining point A at which the joined members 1 and 2 are to be joined is located on the rotation center C1 of the rotary tool 20 and the axis C2 of the pedestal 30.

<Joining Step> As shown in FIG. 4, the motor and the actuator (not shown) of the articulated robot are operated to rotate the rotary tool 20 at a predetermined rotation speed (about 2000 rpm in this embodiment) while rotating it. Tool 20
The protrusion 21 was pressed against the joining point A of the members 2 to be joined with a predetermined pressing force (about 200 kgf in this embodiment), and the entire protrusion 21 was inserted into the members 1 and 2 to be joined.
At this time, the protrusion 21 of the rotary tool 20 penetrated the member 2 to be welded, and the tip of the protrusion 21 passed through the welding interface between the members 1 and 2 and entered the inside of the member 1 to be welded. This state is maintained for about 2 seconds, and the materials of both members to be joined 1 and 2 are softened in the non-melted state and stirred at the joining interface between the members to be joined 1
And 2 were joined together to obtain a joining member 10.

In this embodiment, with respect to the members 1 and 2 to be joined which are horizontally arranged on the pressure receiving surface 31 of the pedestal 30,
The rotary tool 20 was pressed exactly from the vertical direction.

Further, in this embodiment, the pressure receiving surface 31 of the pedestal 30 is provided with the circular recess 32 and the circumferential recess 33. Therefore, in this joining step, as shown in FIG. 5, the rotation center C1 (that is, the rotation center C1) on the surface of the joined member 1 that abuts the pressure receiving surface 31 is formed by the circular recess 32 and the circumferential recessed portion 33. , A circular circular bulge 1 centered on the joint point A) on which the convex portion 21 of the rotary tool 20 is pressed
1 and a circumferential molding protrusion 1 centered on the rotation center C1
2 and 2 were molded.

<Evaluation Step> The joining member 10 thus obtained is subjected to a pressing force from the rotary tool 20 by the circumferential forming convex portion 12 formed by the circumferential concave portion 33 as the detecting means. The pressure received by the pressure receiving surface 31 of the pedestal 30 was compared in the circumferential direction around the rotation center C1.

That is, the degree of forming of the circumferential forming convex portion 12 was compared in the circumferential direction around the rotation center C1 (joint point A). As a result, the circumferential forming convex portion 12 of the joining member 10 obtained in this example is arranged on the circumference centered on the joining point A, and has a constant width (width 1 mm) in the circumferential direction. It had a constant height (height 0.5 mm) and was uniformly molded in the circumferential direction around the joint point A.

As a result, in the above joining step, the pedestal 3
The pressing force from the rotary tool 20 uniformly acts on the pressure receiving surface 31 of 0 in the circumferential direction around the rotation center C1, and the pressure receiving force on the pressure receiving surface 31 is uniform in the circumferential direction around the rotation center C1. It was confirmed that it was. Therefore, even in the entire joining interface between the members to be joined 1 and 2, the rotary tool 20
The pressing force from acts uniformly, resulting in a uniform softened state,
It can be judged that they are bonded uniformly.

Therefore, the joining member 10 according to the present embodiment, in which the circumferential forming convex portions 12 are evenly formed in the circumferential direction, has high joining strength reliability.

On the other hand, as shown in FIG.
The rotary tool 20 tilted obliquely was pressed against the members 1 and 2 to be welded which were horizontally arranged on the pressure receiving surface 31 of the above. That is, the rotary tool 20 was pressed against the axis C2 of the pedestal 30 with the axis C1 (center of rotation) C1 of the rotating rear portion 20 (protrusion 21) inclined by a predetermined angle θ.

As shown in FIG. 7, the joining member 10 'thus obtained was formed on only one side of the joining point A in the shape of a forming projection 12' having an arc shape corresponding to about half the circumference.

As a result, in the joining process, the pedestal 30
The pressing force from the rotary tool 20 acts non-uniformly on the pressure receiving surface 31 of the rotary tool 20 in the circumferential direction around the rotation center C1, and the pressure receiving force of the pressure receiving surface 31 is uneven in the circumferential direction around the rotation center C1. It was confirmed that it was uniform. Therefore, in this joining member 10 ′, even in the entire joining interface between the members 1 and 2 to be joined, the pressing force from the rotary tool 20 acts non-uniformly, resulting in a non-uniform softening state and non-uniform joining. You can judge that

As described above, according to this embodiment, by comparing the forming degree of the forming convex portion 12 formed on the surface of the joining member 10 after the joining process in the circumferential direction around the rotation center C1, the quality of joining can be determined. It becomes possible to easily judge the appearance.

(Embodiment 2) In this embodiment, a pressure sensor 34 as a detecting means is provided on the pressure receiving surface 31 of the receiving base 30, and the pressure receiving surface 31 of the receiving base 30 has a circular recess 32 and a circular shape. Instead of providing the recessed portion 33, four pressure sensors 34
The same as Example 1 except that is provided.

That is, in this embodiment, the four pressure sensors 34 capable of detecting the pressure receiving force are provided on the pressure receiving surface 31 of the receiving base 30 on which the pressing force of the rotary tool 20 acts. The pressure sensors 34 are evenly arranged at 90 degree intervals in the circumferential direction around the axis C2 of the pedestal 30, that is, around the rotation center C1 of the rotary tool 20. It should be noted that each pressure sensor 34 is embedded in the pedestal 30, and the pressure sensing portion of the pressure sensor 34 is exposed on the pressure receiving surface 31 and is disposed on the pedestal 30.
Is directly contacted with.

In the present embodiment, during the joining process, the pressure received by the pressure receiving surface 31 is detected by each pressure sensor 34, and compared with the circumferential direction around the rotation center C1 to easily determine the quality of the joining. You can judge.

That is, as long as the pressure receiving force detected by each pressure sensor 34 is uniform in the circumferential direction around the rotation center C1 (the pressure receiving pressure detected by each pressure sensor 34 is substantially equal), the bonding interface is also good. It can be judged that they are in a proper joined state. On the other hand, when the pressure received by each pressure sensor 34 is uneven in the circumferential direction around the rotation center (for example, 4
If only one of the received pressures detected by the individual pressure sensors 34 is lower than the other three pressure sensors 34), it can be determined that a bonding failure has occurred.

[0063]

As described above in detail, according to the present invention, it is possible to easily judge whether or not the entire joint interface is softened uniformly in the friction stir welding.

Therefore, it is possible to provide a joining member having a high joining strength.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating a manner of friction stir welding according to a first embodiment.

2A and 2B show a pedestal according to Embodiment 1, FIG. 2A is a plan view of the pedestal, and FIG. 2B is a partial sectional view of the pedestal.

FIG. 3 is a partial cross-sectional view showing a state after an arranging step of arranging a member to be joined on a pedestal according to the first embodiment.

FIG. 4 is a partial cross-sectional view showing a state after a joining step of friction stir welding by pressing vertically against a member to be joined while rotating a rotary tool according to the first embodiment.

FIG. 5 shows a joining member with good joining obtained by pressing a rotary tool vertically against a member to be joined and friction stir welding according to the first embodiment, and (a) is a partial cross-sectional view of the joining member. , (B) are bottom views of the joining member.

FIG. 6 is a partial cross-sectional view showing a state after a joining step of friction stir welding by pressing diagonally against a member to be joined while rotating a rotary tool according to the first embodiment.

FIG. 7 shows a joining member with poor joining obtained by obliquely pressing a rotary tool against a member to be joined and friction stir welding according to the first embodiment, and (a) is a partial cross-sectional view of the joining member. , (B) are bottom views of the joining member.

FIG. 8 is a partial cross-sectional view showing a state after a joining process in which a rotary tool is rotated and pressed against a member to be joined by friction stir welding according to the second embodiment.

[Explanation of symbols]

1, 2 ... Joined member 10 ... Joined member 12 ... Circumferentially formed convex portion 20 ... Rotating tool 21 ... Projection 30 ... Cradle 31 ... Pressure receiving surface 32 ... Circular concave portion (concave portion as detecting means) 34 ... Pressure sensor (detection means)

Claims (7)

[Claims] 1. A detection tool for detecting a pressure receiving force on a rotary tool having a protrusion at a tip thereof and rotatable about an axis of the protrusion as a rotation center, and a pressure receiving surface on which a pressing force of the rotary tool acts. A step of disposing a plurality of members to be joined on the pedestal by using a pedestal in which the means is disposed substantially evenly in the circumferential direction around the rotation center; While pressing the rotating tool against the arranged member to be welded while rotating the rotary tool, the projection is inserted into the member to be joined, and the material of the member to be joined is agitated by friction in a non-melted state. A friction stir welding method comprising sequentially performing a joining step of joining members to be joined together. 2. The detecting means is a concave portion or a convex portion provided concavely or convexly on the pressure receiving surface, and in the joining step, the concave portion or the surface of the member to be joined that abuts the pressure receiving surface. The friction stir welding method according to claim 1, wherein a molding convex portion or a molding concave portion is molded by the convex portion. 3. The friction stir welding method according to claim 1, wherein the detection means is a pressure sensor capable of detecting the received pressure. 4. A pedestal in which a plurality of members to be joined are arranged in an overlapping manner, and a protrusion is provided at the tip, and the pedestal is mounted on the pedestal while being rotated around the axis of the protrusion as a rotation center. In a friction stir welding apparatus provided with a rotary tool that is pressed against the member to be welded placed, in the pedestal, a detection means for detecting a pressure receiving force is applied to a pressure receiving surface on which a pressing force of the rotating tool acts. A friction stir welding device, wherein the friction stir welding device is arranged substantially evenly around the rotation center. 5. The friction stir welding apparatus according to claim 4, wherein the detection means is a concave portion or a convex portion that is concave or convex on the pressure receiving surface. 6. The friction stir welding apparatus according to claim 4, wherein the detection means is a pressure sensor capable of detecting the received pressure. 7. A rotary tool having a protrusion at its tip and rotatable about an axis of the protrusion as a center of rotation, and a concave or convex portion on the pressure receiving surface on which the pressing force of the rotary tool acts. Using a pedestal that is concavely or convexly provided substantially evenly in the circumferential direction around the pedestal, pressing the rotating tool while rotating the rotary tool at the joining point of a plurality of members to be joined that are arranged in an overlapping manner on the pedestal. A joining member obtained by friction stir welding for joining the members to be joined by frictionally stirring the material of the members to be joined in a non-molten state by inserting the protrusion into the inside of the members to be joined. A joining member, characterized in that the forming protrusions or forming recesses formed by the recesses or the protruding portions are provided substantially evenly in the circumferential direction around the joining point.