JP2002045981A - Method of friction stir welding and friction stir welding structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize welding of hollow members without the support of a tool, and further to realize welding of members to be welded having a curved face. SOLUTION: In a method of friction stir welding by which a rotating tool 1 (denoted as a tool hereafter), whose material is harder than the members to be welded and provided with two shoulders 3a and 3b stouter than a locally slim pin 2 which is clamped by the shoulders located with a predetermined space, is used, and the welding is performed by frictional heat generated by the rotational action of the tool 1 against the members to be welded while the members 4a and 4b to be welded are clamped between two shoulders 3a and 3b, and the thickness of the members 4a and 4b to be welded which are clamped between the shoulders is larger than the gap between the two shoulders 3a and 3b.

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, a joining structure, and a joining apparatus, and more particularly to an invention that contributes to improving joining quality by preventing joining defects such as cavities and cracks generated in a joining portion.

[0002]

2. Description of the Related Art In a friction stir welding method, a tool made of a material that is substantially harder than the material of the welding is inserted into a joint of a workpiece.
The method is a method of joining by using frictional heat generated between the tool and the joining material by moving the tool while rotating the tool. This is a special publication 7-50509
It is known from Japanese Patent Publication No. 0 (EPO615480B1). That is, the method utilizes a plastic flow phenomenon caused by frictional heat between the tool and the joining material, and does not weld by melting a workpiece as in arc welding.

Further, this joining method is different from the conventional method of rotating the workpieces and joining them by frictional heat, as in the conventional friction welding method, and continuously joining the joining material in the joining line direction, that is, in the longitudinal direction. There is a characteristic that can be welded.

[0004]

[Problems to be solved by the invention]
The tool in the friction stir welding method according to Japanese Patent Publication No. 090 includes a pin portion and a shoulder portion thinner than the pin portion. When joining by the method of the above publication, a tool is inserted into the joining material and joined. That is, since the joining is performed while pressing the joining material with the tool, a large pressing force acts on the joining material. Therefore, a support plate or a supporting column for supporting the pushing force of the tool in a direction opposite to the tool is necessary.

[0005] On the other hand, the tool of the present invention has two shoulder portions which are thicker than the pins so as to sandwich the pin portions at a fixed interval from both sides. That is, in the friction stir welding method of the present invention, the joining material is joined by the two shoulders so as to sandwich the joining material from the front surface and the back surface.
Therefore, there is a feature that the pressing force of the tool is zero (0) as in the above-mentioned publication. However, the joining method in which the joining material is surrounded by the two shoulders has the following problems.

(1) The distance between the two shoulder portions and the distance between the surfaces of the bonding material greatly affect the quality of the bonded portion. For example, when there is a gap between the gap between the shoulder portions and the bonding material, no pressure is applied to the bonding portion, and thus a hollow defect occurs. Further, when the distance between the shoulder portions and the thickness of the joining material are the same, the portion sandwiched by the shoulder portions is cut in the joining process, so that the thickness becomes smaller than the thickness of the portion other than the joined portion. For this reason, there is a problem in terms of the quality of the joint and the appearance. Therefore, the thickness of the joining material in the joining process needs to be larger than the distance between the two shoulder portions.

(2) In the above-mentioned joining method, the joining material is sandwiched between the front and back surfaces by two shoulders, so that the joining material is cut on both front and back surfaces. For this reason, when there is a gap between two joining materials that are joined to face each other, there is a shortage of the joining material that fills the gap, so that the tendency of occurrence of joining defects increases.

(3) The surface of the bonding material is generally uneven.
Not a constant thickness. In particular, when the joining material is long, this change in thickness is remarkable. Further, even when the thickness of the joining material is constant, the height of the joining material surface changes due to frictional heat during the joining process. Therefore, it is necessary to adjust the position of the tool in the joining process up and down according to the change in the unevenness of the joining material surface.

(4) In the bonding method, it is preferable that a center of a thickness of the bonding material is bonded at a center between the two shoulders. For this reason, it is necessary to join while adjusting so that the joining material is always joined at the center between the shoulders.

[0010] (5) In the above-mentioned joining method, the joining material is joined by sandwiching the joining material from both the front surface and the back surface between the two shoulder portions. Generates frictional heat. For this reason, the distortion of the joining material in the joining process and after joining is also doubled, the quality of the joined body is reduced, and a repair work after joining is required, which is problematic in terms of cost. Further, if it becomes difficult to restrain the joining material in the joining process, there is a problem in workability.

[0011]

The tool of the present invention has two shoulder portions which are thicker than the pin so as to sandwich the pin at a fixed interval from both sides. In other words, in the friction stir welding method of the present invention, the joining material is joined between the two shoulders so as to sandwich the joining material from the front surface and the back surface. For this reason, the pressing force of the tool, that is, the reaction force of the tool becomes zero (0), so that it is possible to join even a structure having no rib supporting the pressing force at the lower part of the tool.

The above object (1) can be achieved by making the thickness of the joining material larger than the distance between the two shoulder portions. This can be achieved by locally increasing the thickness of the bonding material at the portion sandwiched between the shoulder portions in advance.

[0013] The above object (2) can be attained by making the shape of the joint portion of the two opposed joining members to be butt joined into a mutually fitting structure.

[0014] The problem (3) is that a detector for detecting the height of the joining material is disposed in front of the tool, on the front surface and / or the back surface of the joining material, and a change in height from the detector is provided. This can be achieved by manually or automatically controlling the position of the tool in the vertical direction in accordance with the detection signal.

[0015] The problem (4) is to arrange the rotating rolls so that both surfaces of the joining material are sandwiched between the front and / or the rear in the joining direction of the tool, so that the deformation and unevenness of the joining material are achieved. Can be joined while straightening. Therefore, even a joining material having a curved surface and a curvature can be easily joined.

The object (5) can be attained by joining under water or in the vicinity of the tool locally or by applying water or oil or a cooling gas to the entire joining material.

By locally increasing the thickness of the joining material sandwiched between the shoulder portions from other portions, the joining material can be joined in a state where pressure is applied stably from both the front surface and the back surface. For this reason, a healthy joint having no defect in the joint can be obtained. Even if a local dent is formed by the cutting by the shoulder, the thickness is previously increased even after the dent locally occurs, so that the thickness after the joining becomes the same as the thickness outside the joint. Further, even when there is a gap between the butting portions of the two joining materials, the joining metal can be locally replenished from the thick portion, so that joining can be performed without defects.

[0018] Further, by forming the structure of the joining portion of the two joining materials which are joined to face each other into a fitting structure, even if a gap is formed in the joining portion, the gap is replenished by the fitting portion. Can be joined without.

On the other hand, detectors for detecting the height of the surface of the joining material are arranged on both surfaces or one of the joining materials in front of the tool. By manually or automatically controlling the position of the tool in the vertical direction according to the detection signal of the change in the height of the bonding material surface from the detector, it is always stable even if the thickness or deformation of the bonding material occurs Bonding is possible.

Further, by disposing rotating rolls so as to sandwich both surfaces of the joining material in front and / or rear of the joining direction of the tool, deformation and unevenness of the joining material are corrected before joining. Therefore, it is possible to stably join even a joining material having a curved surface structure.

On the other hand, by joining the entire joining material including the local portion or the joining portion in the vicinity of the tool while applying a coolant such as water, oil, or gas, the joining can be performed at a low temperature without deformation, so that stable joining can be achieved. . Since the internal pressure of the joint is higher than the atmospheric pressure due to the rotation of the tool and the heat of friction, water does not enter the inside of the joint.

According to the above method, it is possible to join even a structure having no support plate or support column on the opposite side of the tool against the pressing force of the tool. For this reason, the weight of the joint structure can be reduced.

[0023]

(Embodiment 1) FIG. 1 shows a cross section of a tool structure according to an embodiment of the present invention. The tool 1 has two shoulder portions 3 arranged so as to surround the thin pin portion 2.
a and 3b. The diameter (D) of the shoulder 3 is larger than the diameter (d) of the pin 1. The distance (L) between the two shoulders 3a and 3b is determined by the thickness of the joining material, and the outer distance (L) is preferably smaller than the inner distance (X). The angle (α) between the outside and the inside is desirably 1 to 10 degrees. When the distances L and X are the same, defects are likely to occur. In the tool having the above structure, it rotates integrally.

FIG. 2 shows the shape of the joining material of the present invention. FIG.
As shown in (1), the joining material of the present invention is characterized in that the joining portion is locally thickened. It is desirable that the width (A) of the locally thick portion be equal to or slightly larger than the diameter (D) of the shoulder portion 3. It is desirable that the thickness (H) of the joint portion sandwiched between the shoulder portions is 0.2 mm or more and 3 mm or less than the total thickness (h) of the joining material. If it is less than 0.2 mm, dents and defects are likely to occur in the joining material. In case of 3mm or more, the cost and the load (reaction force) on the tool in the joining direction
There is a problem in that the number increases.

In this embodiment, the entire thickness (h) of the bonding material is 3 mm, but the thickness (H) of the portion in contact with the shoulder portion 3 is 4 mm, which is locally thick. In addition,
The distance (L) between the upper and lower shoulders in this embodiment is 3 mm,
The diameter of the pin part is 8 mm, and the diameter of the shoulder part is 20 mm.

Here, the thickness (H) of the bonding material sandwiched between the shoulder portions is 4 mm, which is locally thicker than the upper and lower spacing (L) of 3 mm of the shoulder portions.

The locally thick portion of the joining material that is in contact with the shoulder portion is mechanically cut from both the front surface and the back surface of the shoulder portion during the joining process. It will be the same thickness of 3mm.

The joining material is an aluminum alloy of JIS standard 6N01. The width of the aluminum alloy is 500m each
m, length is 25 m. The joining speed of the tool is 5
00 mm / min and the rotation speed is 800 rpm. Here, as shown in FIG. 2, it is desirable that the tool is inclined with respect to the joining direction. This inclination angle (θ) is desirably 1 to 3 degrees. The joining material joined according to the above embodiment provides a sound joint without defects, and the joining is applied to railway vehicles, ships, and aviation equipment. (Embodiment 2) FIG. 2 shows a cross section of a joint structure in an embodiment of the present invention. It is characterized in that the thickness (H) of the joining portion between the joining materials 4a and 4b is locally thicker than the thickness (h) other than the joining portion, and has a structure in which they are fitted to each other.

The depth (C) of the fitting portion is desirably 0.5 mm or more and 4 mm or less. That is, when the diameter is less than 0.5 mm, the effect is small, and when the diameter is more than 4 mm, the diameter becomes larger than the diameter (d) of the pin 2 of the tool.

FIG. 4 is a cross-sectional view of an embodiment in which the joining material of FIG. 3 is joined by the tool of FIG. FIG. 5 is a cross-sectional view in the AB direction of FIG. 3, that is, the joining direction. 4 and 5, the tool 1 is arranged so that the joining members 4a and 4b are sandwiched between the shoulder portions 3a and 3b. The pin portion 2 and the shoulder portion 3 move in the joining line direction 6 while rotating 5 integrally. At this time, the joining material 4 is joined by frictional heat generated between the rotation of the pin 2 and the joining material 4. The thickness (f) after joining 7 joined by the above method is almost equal to the thickness (h) other than the joining portion. (Embodiment 3) In this embodiment, a method of detecting a change in the vertical direction and unevenness of the surface of the bonding material and controlling the position of the tool in accordance with the change will be described.

In FIG. 6, a laser displacement detector 8 for detecting the unevenness of the surface of the bonding material 4 and a change in the vertical direction is disposed in front of the tool 1 to detect the unevenness of the bonding material 4 and a change in the vertical direction. The detection signal detected by the detector is converted into an electric signal by the signal control device 10. The control device 1
0 controls the vertical position of the tool 1 by controlling the hydraulic cylinder 12 connected to the rotation motor 11 of the tool in accordance with the change of the detection signal. The tool, drive motor, hydraulic cylinder, laser displacement detector, and the like are all mounted on a highly rigid base 13. Joining the tool 1
The gantry 13 moves with the rotation of
It is possible even if moves.

In this embodiment, the joining material is an aluminum alloy having a total thickness of 4 mm, a width of 500 mm, and a length of 25 m.
S standard 6N01 material. The thickness of the portion sandwiched between the shoulders is 5 mm, the diameter of the pin 2 is 8 mm, the diameter of the shoulder portion is 20 mm, and the distance (L) between the upper and lower shoulder portions is 4.3 mm. Further, the joining speed of the tool is 500 mm / min, and the rotation speed is 1000 rpm.

As described above, since the length of the joining material is as long as 25 m, the thickness of the joining material varies and the entire surface has irregularities. However, the height of the tool depends on the deformation of the joining material in the joining process. In order to control the height up and down, the bonding material is 25
Even if the length is as long as m, bonding can be performed stably without defects. In particular, the above embodiment can be effectively applied as a roof structure and an outer structure for a vehicle having a long joint length.

The thickness and the vertical displacement of the bonding material are detected on the front and back surfaces of the bonding material using a 10 MHz ultrasonic signal in the same manner as described above, and the tool is vertically moved with respect to the bonding material surface. Can control position. (Embodiment 4) In this embodiment, a method is described in which laser displacement detectors are arranged on both the front surface and the back surface of the bonding material, and the position of the tool is controlled in accordance with the vertical change and unevenness of the bonding material. explain.

FIG. 7 shows laser displacement detectors 8a and 8b arranged on both the front and back surfaces of the bonding material. The two detectors 8 independently detect irregularities on the front and back surfaces of the bonding material and changes in the vertical direction. The two detection signals 9a and 9b detected by the detector are converted into electric signals by the control device 10. Further, the control device 10 compares the magnitudes of the two detection signals 9a and 9b. That is, the magnitude of the unevenness on the front and back surfaces of the bonding material or the magnitude of the change in the vertical direction is compared as an electric signal. Here, said 2
The hydraulic cylinder 12 connected to the rotary motor 11 of the tool 1 is controlled so that the difference between the two detection signals 9a and 9b becomes a preset value, and the vertical position in the joining process of the tool 1 is controlled.

The aluminum alloy of the bonding material 4 of this embodiment is a JIS standard 6013 material having a total thickness of 4 mm, a width of 500 mm, and a length of 25 m. The thickness of the joining material between the shoulders is 5 mm, the diameter of the pin portion is 8 mm, the diameter of the shoulder portion is 20 mm, and the distance (L) between the upper and lower shoulder portions is 4.3 m.
m. Furthermore, the joining speed of the tool is 500mm / min,
The rotation speed is 1000 rpm.

As described above, since the length of the joining material is as long as 25 m, there are variations in the thickness of the joining material and unevenness as a whole. However, the height of the tool is changed according to the deformation of the joining material in the joining process. Since the drive is controlled up and down, even if the joining material is as long as 25 m, joining can be stably performed without defects. The joined body joined in the above embodiment can be used as a floor structure for a vehicle, an outer structure, and a floor plate for a ship.

The thickness and the vertical displacement of the bonding material are detected on the front and back surfaces of the bonding material by a 5 MHz ultrasonic signal in the same manner as described above, and the tool is vertically moved with respect to the bonding material surface. Can control position. (Embodiment 5) In this embodiment, a joining method for joining the joining material 4 having a curved surface structure by disposing rotating rolls 14a and 14b sandwiching the joining material 4 from both sides in front of the tool will be described.

In FIG. 8, in addition to the laser displacement detector 8 of the embodiment shown in FIG. 7, rotating rolls 14a1 and 4b sandwiching the bonding material 4 from both sides are disposed in front of the tool. The roll 14 corrects unevenness of the surface of the bonding material and deformation in the vertical direction in the bonding process before bonding.

That is, the joining is performed by the tool while the unevenness and deformation of the joining material surface are corrected by the roll before joining. Here, the position of the roll 14 in the height direction is the same as the position of the tool 1 in the height direction. It is desirable that the position of the roll 14 in the joining direction be as close as possible to the position of the tool 1.

The joining material in this embodiment is an aluminum alloy having a total thickness of 6 mm, a width of 500 mm and a length of 10 m.
It is S standard 5052 material. The thickness of the joining material sandwiched between the shoulders is 6.6 mm, the distance (L) between the upper and lower shoulder portions is 6 mm, the diameter of the pin portion is 10 mm, and the diameter of the shoulder portion is 30 mm. Furthermore, the joining speed of the tool is 500mm /
min, the number of revolutions is 1000 rpm.

As described above, since the length of the joining material is as long as 25 m, the thickness of the joining material varies and the entire surface has irregularities. However, the surface of the joining material in the joining process is smoothed by the roll. Therefore, even if the joining material is as long as 10 m, joining can be performed stably without defects. The joined body joined in the above embodiment can be used as a floor structure and an outer structure of a ship. Further, the present invention can be applied to railway vehicles and automobile members. (Embodiment 6) In this embodiment, as shown in FIG. 9, the rotating members 14a and 14b and 14c and 14d sandwiching the joining material 4 from both sides thereof are arranged in front of and behind the tool. A joining method for joining the two will be described. That is, the unevenness and the vertical deformation of the surface of the joining material in the joining process are corrected by the roll 14 before the joining. Here, the position of the roll 14 in the height direction is the same as the position of the tool 1 in the height direction. It is desirable that the position of the roll 14 in the joining direction be as close as possible to the position of the tool 1.

FIG. 9 shows a fourth embodiment in addition to the rotary roll.
7 is arranged, and the vertical position of the tool is adjusted based on this detection signal.

The bonding material in this embodiment is an aluminum alloy having a total thickness of 6 mm, a width of 500 mm and a length of 10 m.
It is S standard 5052 material. The thickness of the joining material sandwiched between the shoulders is 6.6 mm, the distance (L) between the upper and lower shoulder portions is 6 mm, the diameter of the pin portion is 10 mm, and the diameter of the shoulder portion is 30 mm. The joining speed of the tool is 500 mm / min, and the rotation speed is 700 rpm.

As described above, since the length of the joining material is as long as 25 m, the thickness of the joining material varies and there are irregularities as a whole, but the surface of the joining material in the joining process is smoothed by the roll. Therefore, even if the joining material is as long as 10 m, joining can be performed stably without defects. The joined body joined in the above embodiment can be used as a floor structure and an outer structure of a ship. Further, the present invention can be applied to railway vehicles and automobile members. (Embodiment 7) FIG. 10 illustrates a case where the present invention is applied to joining of a honeycomb panel 15 having a hollow structure. FIG.
Honeycomb panel 15 is made of aluminum alloy JIS standard 6N0
It is a hollow structure made by extruding one material and having a rib 16 inside. Honeycomb panel 1 according to the present invention
The joining of 5 is performed at a position where there is no rib 16. That is, it is characterized in that it can be joined even at a position where there is no supporting material for supporting the load of the tool 1.

The thickness of the front and back surfaces of the honeycomb panel is 3 mm, and the thickness of the joint 17 sandwiched between the shoulders is 4.2 mm, which is locally large. Further, as shown in FIG. 2 of the first embodiment, the structures of the joints are fitted into each other.

The width of one honeycomb panel is 400.
mm, length is 25 m.

In this embodiment, the distance (L) between the upper and lower shoulder portions is 3.5 mm, the diameter of the pin portion is 8 mm, and the diameter of the shoulder portion is 25 mm. The bonding speed in this embodiment is 50
0 mm / min and the rotation speed is 800 rpm. By joining under the above joining conditions, a joint having no defect over a length of 25 m can be obtained. The locally thick portion of the honeycomb panel sandwiched between the shoulder portions is mechanically cut from both the front surface and the back surface of the shoulder portion during the joining process. The same thickness of 3 to 3.5 mm eliminates the need for processing after joining.

On the other hand, since the length of the joining material is as long as 25 m, there are variations in the thickness of the joining material and unevenness as a whole. Further, the joining material is deformed by frictional heat during the joining process.
For this reason, in the joining process, it is necessary to drive and control the height of the tool up and down based on the surface of the joining material.

In this embodiment, ultrasonic displacement meters are arranged on both sides of the honeycomb panel face plate to detect the vertical displacement of the joining material. The displacement meter is located 30 in front of the tool.
It is located at the position of mm. The frequency of the deformation meter is 5 MH
z. The vertical drive control device of the tool is controlled by the displacement signal to drive and control the tool in the vertical direction according to the displacement of the thickness. Thereby, even if the joining material is as long as 25 m, joining can be performed stably without defects. Furthermore, since a support column for supporting the tool is not required on the opposite side of the tool, a lightweight structure is possible.

By using the joined body joined in the above embodiment as a roof structure and an outer structure for a vehicle, the weight of the vehicle can be reduced. (Embodiment 8) In this embodiment, a cylindrical tube 1 made of aluminum alloy is used.
8 is applied to the joining in the longitudinal direction.
FIG. 11 is a sectional view of the embodiment, and FIG. 12 is a sectional view in the joining direction. The aluminum alloy is JIS standard 5083
The diameter between the cylinders is 500 mm, the thickness is 5 mm, and the length is 5
m. The thickness of the joint portion of the cylindrical tube, which is sandwiched between the shoulder portions of the tool, is 7 mm in total including the front and back surfaces.
The feature is that it is locally thicker. In this embodiment, the distance between the upper and lower shoulders is 5 mm, the diameter of the pin 2 is 8 mm, and the diameter of the shoulder is 20 mm. In the joining process, the locally thick portion is cut by the shoulder from both front and back sides, so that the thickness (7 mm) of the joined portion after joining is 5 mm, which is the same as the distance between the shoulders.

On the other hand, as for the deformation of the joining material, a laser displacement detector 8 is arranged in front of the tool as in the third embodiment, and the vertical position of the tool 1 is controlled according to the unevenness and deformation of the joining material. ing.

The bonding speed in this embodiment is 300
mm / min and the number of revolutions of the tool is 800 rpm.

In this embodiment, since the thickness of the joining material is a highly rigid aluminum alloy and the thickness is as thick as 7 mm,
A large amount of frictional heat is generated, and the distortion during the joining process is large.
For this reason, as shown in FIG. 12, the cylindrical pipes are joined while being sprinkled with water by water cooling pipes 19 and 20 from both the front and back sides. For this reason, the temperature of the joint surface 3 mm away from the tool can be 100 ° C. or less. Therefore, the joining process and the strain after joining are the same as those in the case of joining in air.
/ 5 to 1/10 or less. The joint 7 joined by the joining method has no defect. For this reason, a cylindrical tube of an aluminum alloy having a precise joining structure can be obtained. The aluminum alloy cylindrical tube joined by the joining method is employed for a chemical plant. (Embodiment 9) In this embodiment, a case where a copper plate is joined by the same joining method as in Embodiment 2 will be described. The thickness of the portion of the copper plate in contact with the shoulder portion is 6 mm, which is locally thicker than the other portions of 5 mm. Further, the joint has a fitting structure similar to that of FIG. In this embodiment, the distance (L) between the upper and lower shoulder portions is 5.2 mm, the diameter of the pin portion of the tool is 10 mm, and the diameter of the shoulder portion is 25 mm. The locally thick portion of the joining material that is in contact with the shoulder portion is mechanically cut from both the front surface and the back surface of the shoulder portion during the joining process.
Thickness. Each of the copper plates has a width of 500 mm and a length of 5
m. The joining speed of the tool is 300 mm / min, and the rotation speed is 1000 rpm.

Here, since the copper plate has higher rigidity than the aluminum alloy, a large amount of frictional heat is generated during the joining process, and the deformation of the copper plate is also increased. Therefore, all of the tool and the joining material were joined in water. Note that the water is circulated so that the temperature in the water is always 20 ° C. or lower. As a result, the temperature of the bonding material surface 2 mm away from the tool is 100 ° C.
The following can be maintained. Therefore, the joining process and the deformation after the joining can be reduced to 1/5 or less of the joining in the air.
The joined body of the joined copper plates was used as a heat sink material for a semiconductor by the above joining method.

[0056]

According to the present invention, since there is no pressing force of the tool, the joining can be performed without the support material of the tool even if the inside is hollow. Furthermore, a joining material having a curved surface can be joined. Therefore, the weight of the joint structure can be reduced. Furthermore, since joint defects are prevented, a highly reliable joint structure can be manufactured even with a joint structure of a 20 m class joint length, such as a vehicle, a ship, or an automobile having a curved surface structure.

[Brief description of the drawings]

FIG. 1 is a sectional view of a tool structure showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a joint structure showing an embodiment of the present invention.

FIG. 3 is a cross-sectional view of a joint structure showing an embodiment of the present invention.

FIG. 4 is a cross-sectional view of a bonding state arrangement showing an embodiment of the present invention.

FIG. 5 is a sectional view in a joining direction showing a joining state according to the embodiment of the present invention.

FIG. 6 is a configuration diagram of a bonded state showing an embodiment of the present invention.

FIG. 7 is a configuration diagram showing a bonded state according to an embodiment of the present invention.

FIG. 8 is a configuration diagram of a bonded state showing an embodiment of the present invention.

FIG. 9 is a configuration diagram showing a bonded state according to an embodiment of the present invention.

FIG. 10 shows a cross section of a bonded state when the present invention is applied to a honeycomb panel.

FIG. 11 is a cross-sectional view of a joined state when the present invention is applied to a cylindrical tube.

FIG. 12 shows a sectional view in the joining direction when the present invention is applied to a cylindrical tube.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotating tool, 2 ... Pin, 3 ... Shoulder, 4 ... Joining material, 5 ... Tool rotation direction, 6 ... Joining direction, 7 ... Joining part, 8 ... Laser displacement detector, 9 ... Displacement signal, 10 ... Control Device, 11 ... Rotary motor, 12 ... Hydraulic cylinder, 13 ...
Stand, 14: rotating roll, 15: honeycomb panel, 16
... ribs, 17 ... joints, 18 ... cylindrical tubes, 19 ... water cooling hoses.

Claims (8)

[Claims] A tool made of a material harder than a material of a joining material is provided by a rotating tool (described as a tool) in which two shoulder portions thicker than said pin are provided at a fixed interval so as to sandwich a thin pin locally. In a friction stir welding method in which the joining material is sandwiched between the two shoulders and joined by the rotating action of the tool and frictional heat between the joining material, the thickness of the joining portion sandwiched between the shoulder portions Is larger than the distance between the two shoulder portions. 2. The friction stir welding structure according to claim 1, wherein the thickness of the front surface and the back surface of the joining material sandwiched between the shoulder portions is locally thicker than other portions. 3. The friction stir welding structure according to claim 1, wherein the joining portions of the joining materials to be butt-joined have a fitting structure facing each other. 4. The method according to claim 1, wherein a rotating roll sandwiching both surfaces of the joining material is arranged at the front and / or the rear in the joining direction with respect to the position of the tool and joined. Friction stir welding method. 5. The friction stir welding according to claim 1, wherein the tool is joined locally or the tool and the joining material are joined while applying a coolant from both or one of the surface and the surface. Method. 6. A rotary tool (described as a tool) having a tool harder than the material of the joining material and having two shoulder portions thicker than the pin at a fixed interval so as to sandwich a thin pin locally. In a friction stir welding method in which the joining material is sandwiched between the two shoulders and joined by a rotating action of the tool and frictional heat between the joining material and the friction stir welding method, both or one of the front surface and the back surface of the joining material is used. On the other hand, a detector that detects a change in the height of the bonding material surface and the back surface in the bonding process is arranged, and the detector sequentially detects a change in the height of the bonding material surface in the bonding process, and detects the height of the bonding material. A friction stir welding apparatus comprising a mechanism for manually or automatically driving and controlling the position of the tool in a vertical direction according to a change. 7. A friction stir welding apparatus according to claim 1, wherein the detector for detecting the height of the workpiece surface is a laser displacement meter, an ultrasonic displacement meter, or a contact type displacement meter. . 8. A joined structure manufactured by the method according to claim 1.