JP2003260572A - Method and tool for frictional agitation bonding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a frictional agitation bonding method reducing unjointed area in the vicinity of a counter on which a board to be bonded is placed. <P>SOLUTION: In the method, a rotating tool for frictional agitation bonding 200 fixes a tool member 230 to the end of a cylindrical member 210 with screws. A second minor diameter 241 passes through the turning center of the tool member 230 to protrude beyond a minor diameter 231 of the tool member 230. A spring 250 is provided inside the cylindrical member 210 to depress the second minor diameter 241 towards the end side. This second minor diameter 241 is made to approach a counter 20 to do frictional agitation bonding. When the second minor diameter 241 makes contact with the counter for any reason, the second minor diameter 241 backs off to avoid contact. Therefore the normal distance between the second minor diameter 241 and the counter 20 can be shortened to minimize unjointed area. <P>COPYRIGHT: (C)2003,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 a rotary tool used therefor.

[0002]

2. Description of the Related Art A rotary tool for a friction stir welding method comprises a small diameter portion to be inserted into a welding portion and a large diameter portion located outside. The boundary between the small diameter portion and the large diameter portion is slightly inserted in the joint portion. The small diameter portion and the large diameter portion are coaxial. This is patent 30707
No. 35 (USP 6050474).

In the case of friction stir welding the abutting portions of the plates, the plates are placed on a pedestal. The small diameter part of the rotary tool is inserted up to near the back surface of the plate (mounting side). In this case, if the rotary tool is excessively inserted, the tip of the small diameter portion contacts the gantry. Then, various inconveniences occur. For example, the plates are joined to the pedestal so that they do not separate. On the other hand, when the insertion of the rotary tool is insufficient, unbonded portions are generated on the back surface and the side of the plate, resulting in poor strength. The excess and deficiency of this insertion allowance is
It occurs due to various factors such as the accuracy of the friction stir welding apparatus.

Therefore, the small diameter portion is provided so as to be capable of expanding and contracting with respect to the large diameter portion, and when the small diameter portion comes into contact with the pedestal, the small diameter portion is retracted against the spring by the load so that the small diameter portion does not come into strong contact with the pedestal. I have to. This is USP 5718366
Is shown in.

[0005]

If the small-diameter portion is set back when the small-diameter portion comes into contact with the gantry, the tip of the small-diameter portion can be inserted close to the gantry.

However, the rotary tool is inserted with an extremely large force. In normal times, it is necessary to prevent the small diameter part from retracting. Therefore, the spring force pressing the small diameter portion is large. Requires large springs and large rotating tools. Although it is called a small diameter portion, its diameter is relatively large, so it is necessary to increase the spring force.

The present invention provides a friction stir welding method that reduces unwelding and joining with a gantry.

[0008]

According to the present invention, a first small diameter portion is provided at the tip of the large diameter portion, and a second portion is provided from the tip of the first small diameter portion.
Of the small diameter portion of the small diameter portion is inserted into a plate material mounted on a mount using a tool in which the small diameter portion of the second small diameter portion is made to project and the second small diameter portion is made to expand and contract with respect to the first small diameter portion. The tip is inserted up to the vicinity of the gantry, and the small diameter portion is allowed to expand and contract toward the large diameter portion side by a load applied in the axial direction of the small diameter portion, and the tool is moved while rotating.
It is characterized by.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. In FIG. 3, the upper right A is connected to the lower left A. In addition, FIGS. 1, 4, and 5 are cross-sectional views for facilitating understanding of the relationship between the connecting portion of the center member 240 and the cylindrical member 210, particularly the rotation preventing portion 244. Therefore, the center member 240 and the cylindrical member 21
2 and 3 are correct as to the relationship with the coupling portion with 0, especially with the rotation preventing portion 244.

The friction stir welding rotary tool 200 includes a cylindrical member 210, a friction stir welding tool member 230 attached to the tip of the cylindrical member 210, a center member 240 slightly protruding from the tool member 230, A spring 250 for pressing and a fixing member 260 for fixing the spring 250. As for the cylindrical member 210, the friction stir welding device is a rotary tool 2
This is the part that grabs 00 and rotates it.

A small diameter cylindrical portion 2 is provided at one end of the cylindrical member 210.
There are 12 and there is an external thread 213 in this part. A groove 215 along the radial direction is provided on the tip side of the cylindrical portion 212. A screw 218 is provided on the inner surface of the other end of the cylindrical member 210.

The tool member 230 has a small diameter portion 231 and a large diameter portion 233 called a shoulder portion. The end surface of the large-diameter portion 233 on the small-diameter portion 231 side has a tapered portion 2 in which the center side is recessed.
34. The outer surface of the small diameter portion 231 has a screw.
As is well known, the small diameter portion 231 is inserted into the plate material 30 to be joined, and a part of the large diameter portion 233 is also inserted into the plate material 30.

At the end of the large diameter portion 233 opposite the small diameter portion 231, there is a cylindrical portion 236. The inner surface of the cylindrical portion has a cylindrical portion 2
There are screws that fit into the twelve screws 214. Due to this screwing, the end surface of the cylindrical portion 236 contacts and is fixed to the end surface of the cylindrical member 210. There is a hole 238 therethrough at the center of rotation of the tool member 230. The hole 238 penetrates the cylindrical portion 236, the large diameter portion 233, and the small diameter portion 231.

The center member 240 comprises a second small diameter portion 241 penetrating the hole 238 of the tool member 230, a rotation stopping portion 244, a cylindrical base portion 247 and the like. The second small-diameter portion 241 penetrates the hole 238, and the tip of the second small-diameter portion 241 is attached to the small-diameter portion 23.
1 is projected from the tip. The anti-rotation portion 244 has a substantially rectangular cross section in a direction orthogonal to the axial direction, enters the inside of the cylindrical portion 236, and enters the bottom of the cylindrical portion 236 (the large diameter portion 2).
End portion 33) 236b. The base 247 has a circular cross section. At the tip of the base 247 is a protrusion 248 that enters the inside of the spring 250. The tips of the small diameter portions 231 and 241 have an arc shape.

The detent 244 is in the groove 215. Further, the circular base portion 247 is contained in the cylindrical portion 212.

The coil spring 250 is inserted in the cylindrical member 210. One end of the spring 250 is in contact with the end surface of the base portion 247 of the center member 240. The fixing member 260 is screwed into the screw 218, and the center member 240 is pressed with a predetermined force. At the tip of the fixing member 260, there is a protrusion 262 that enters the inside of the spring 250. The outer shape of the head 263 at the other end of the fixing member 260 is a hexagon for applying a spanner. The end of the east part 263 is in contact with the end of the cylindrical member 210. By tightening the fixing member 260 until the head 263 contacts the cylindrical member 260, the spring 250 is pressed with a predetermined force.

When the above items are assembled as shown in FIG. 1,
Normally, the tip of the second small diameter portion 241 slightly projects from the small diameter portion 231. The protrusion amount is, for example, 1.0 mm. At the time of joining, the rotary tool 20 up to a protruding state of 0.5 mm
0 is inserted. 0.5m from a protruding state of 0.5mm
You can retreat. Further, it is possible to further project 0.5 mm from the projecting state of 0.5 mm. That is, the maximum value of the expansion / contraction amount of the small diameter portion 231 is 1.0 mm.

When the tool member 230 is screwed onto the cylindrical member 210, the tip of the cylindrical portion 236 of the tool member 230 is in contact with the end of the cylindrical member 210. In this state, the cylindrical portion 2
A detent portion 244 is provided between the bottom 236b of 36 and the bottom surface 214b of the groove 214. The distance between the bottom 236b and the bottom surface 215b of the groove 215 is larger than the thickness of the rotation stopping portion 244. The gap between the two serves as the expansion / contraction margin of the second small diameter portion 241.

For example, the diameter of the small diameter portion 231 is 6 mm, the second
The diameter of the small diameter part 241 is 3.5 mm. Thus, the diameter of the second small diameter portion 241 is small. Therefore, the small diameter portion 23
Compared with the case where 1 is expanded and contracted with respect to the tubular member 210,
The force of the spring 260 can be reduced. Therefore, the spring 250
Can be a coil spring having a small diameter, can be inserted into the tubular member 210, and the diameter of the rotary tool 200 can be reduced.

The force for inserting the rotary tool 200 into the members to be joined is extremely large. For example, the diameter of the large diameter portion is 15 mm and is about 700 kg. The second small diameter portion 241 should not retract due to this force. The pressing force of the spring 250 is determined by the insertion force of the rotary tool and the diameter of the second small diameter portion 241.

The rotary tool 200 is inserted into a pair of plate members 30 placed on the pedestal 20, and is moved while being rotated to perform friction stir welding. The tip of the second small-diameter portion is inclined with respect to the upper end of the rotary tool 200 so as to be positioned forward in the moving direction. Above the plate material 30, the plate material 3 is provided from the friction stir welding device.
There is an optical sensor that measures the distance to the top surface of zero. The value detected by this optical sensor determines the height position of the rotary tool 200. During friction stir welding, detection is always performed to always determine the height position of the rotary tool 200.

Therefore, the small diameter portion 231 and the second small diameter portion 2
The distance from the tip of 41 to the backing plate 20 is substantially constant. However, the optical sensor, the device for determining the height position of the rotary tool 200, the accuracy of the plate member 30, the pedestal 20, and
The position of the tip of the second small diameter portion 241 (small diameter portion 231) is different due to factors such as the rigidity of the gantry 20 and the friction stir welding apparatus. The mount 20 is made of iron.

FIG. 4 shows the friction stirring of the rotary tool 200 of the present invention.
It is a longitudinal cross-sectional view for explaining the action at the time of stir welding. Turner
The state in which the tool 200 is inserted is shown in FIG. This state
At the tip of the second small diameter portion 241 and the upper surface of the gantry 20
The gap with 20b is G₁(For example, 0.2 mm or less
It ). In this state, the second small diameter portion 241 is 0.5
Since it projects by mm, the tip of the small diameter portion 231 and the pedestal 20
G between the upper surface 20b of the _TwoIs 0.7m in the above example
m or less. Gap G₁Is 0.2 mm or less, the protrusion
It is possible to bond without causing unbonding at the joint. This gap
G₁A rotary tool 200 having a target value of (0.2 mm or less)
Insert.

As shown in FIG. 4 (b), the second
When the gap G ₁ between the tip of the small diameter portion 241 and the upper surface 20a of the gantry 20 becomes smaller than a predetermined value, the second small diameter portion 241
Contacts the upper surface 20a of the gantry 20. As a result, an upward force acts on the second small diameter portion 241, so that the second small diameter portion 241 immediately retracts. It is considered that an extremely thin metal film is formed between the tip of the second small diameter portion 241 and the upper surface 20b of the gantry 20. by this,
It is considered that the joining of the plate member 30 and the gantry 20 can be prevented.

Therefore, as shown in FIG. 4 (c), the upper surface of the pedestal 20 and the tip of the rotary tool 200 until the tip of the second small diameter portion 241 and the tip of the small diameter portion 231 are substantially flush with each other. It is possible to reduce the distance G ₂ between the and. In the example above, the second
It is possible to allow the gap G ₂ between the tip of the small diameter portion 241 and the upper surface 20a of the gantry 20 to be reduced to 0.7 mm. That is, in the maximum range of 0.7 mm,

Therefore, in the range of maximum 0.7 mm, the second
The contact between the small diameter portion 241 and the pedestal 20 can be substantially prevented, and the joining of the both can be prevented. Further, the gaps G ₁ and G ₂ from the tips of the second small diameter portion 241 and the small diameter portion 231 to the gantry 20 can be reduced, and the unbonded portion can be reduced. Even if there is a gap G ₁ from the tip of the small diameter portion 241 to the back surface of the plate member 30, the vicinity of the tip of the second small diameter portion 241 is friction stir welded by the tip of the second small diameter portion 241 or the tip of the small diameter portion 231. Therefore, the unbonded portion can be eliminated.

On the other hand, when the gap G ₁ increases for some reason, the second small diameter portion 241 projects until it contacts the pedestal 20. A maximum protrusion of 1.0 mm is possible. This state is shown in FIG. Further, even if there is a gap of about 0.2 mm between the tip of the projecting second small-diameter portion 241 and the upper surface of the gantry 20, no unbonding occurs, so the gap G ₁ is 1.2 mm.
Tolerable to some extent.

According to this, the range in which the friction stir welding is affected by the expansion and contraction of the second small diameter portion 241 is only the projecting range of the second small diameter portion 241, which is greater than the case where the small diameter portion 231 is expanded and contracted. It is considered that the range can be reduced and the adverse effect of expansion and contraction can be reduced.

Since the second small-diameter portion 241 is guided by the small-diameter portion 231, even if the second small-diameter portion 241 has a small diameter, bending deformation can be suppressed and the second small-diameter portion 241 can easily expand and contract.

Since the second small-diameter portion 241 is in the vicinity of the small-diameter portion 231 having a slightly larger diameter, even if there is a gap between the abutting portions of the plate members 30, 30, they can be sufficiently friction-stirred and joined.

In practice, we think that the following should be done. Second
When the expansion / contraction amount of the small diameter part 241 is 1.0 mm at the maximum, the gap G between the second small diameter part 241 and the pedestal 20 is in a state where the second small diameter part 241 projects by 0.5 mm which is half the expansion / contraction amount.
₁ is 0 mm (it is considered that there is a thin metal layer between the second small diameter portion 241 and the gantry 20). This is the target position. This is a normal time.

According to this, when the gap G ₁ becomes small for some reason, the second small diameter portion 241 retreats. 0.5
It can cope with the reduction of the gap G ₁ up to mm. On the other hand, if the gap G ₁ increases for some reason, the second small diameter portion 241 projects until it comes into contact with the gantry 20, as described above. The maximum protrusion amount of the second small diameter portion 241 at this time is 1.0 mm.

In friction stir welding, the friction stir welding apparatus grips the cylindrical member 210 and rotates it. If the rotation direction of the tool 200 is clockwise rotation, the small diameter portion 2
The thread of 31 is a right-hand thread. The screw 213 for fixing the tool member 230 to the cylindrical member 210 is a left screw. Also,
The screw 218 for fixing the fixture 260 is a right-hand screw.

As described above, since the screw 213 for fixing the tool member 230 has the opposite screw direction to the rotating direction of the rotary tool 200, the tool member 230 is tightened by the rotation of the rotary tool 200, and the tool member 230 is tightened. The other fixing means of 230 can be made unnecessary.

No screws are provided at the tip of the second small diameter portion 241. If a screw is provided at the tip of the second small diameter portion, fluidized metal may enter the gap between the valley of the screw and the through hole 238, and the second small diameter portion 241 may not expand or contract. In this sense, it is desirable not to provide a screw on the second small diameter portion. When a screw is provided, the second small diameter portion 24
Since it is provided only at the tip of No. 1, it is sufficient. That is, it is sufficient that the screw is provided in the range in which the second small diameter portion 241 is maximally projected. Also, to push the metal outward with screws,
Determine the screw direction. If the rotation direction of the rotary tool 200 is right rotation, the second small diameter portion is a left thread.

The small diameter portion 231 is formed at the tip of the second small diameter portion 241.
You may provide the 3rd small diameter part of a diameter about the same. The third small diameter portion is fixed to the second small diameter portion 241. The third small diameter portion rotates with the second small diameter portion. Second small diameter portion 24
Due to the expansion and contraction of the first and third small diameter portions, there is a gap between the tip of the small diameter portion 231 and the third small diameter portion. In order to assemble the rotary tool, the third small-diameter portion is a member separate from the second small-diameter portion and is fixed with screws or the like. Alternatively, the third small diameter portion and the second small diameter portion 241 are integrally provided, and the second small diameter portion 2
41 and the base portion 247 are separate members, and the second small diameter portion 241
The base 247 and the base 247 are fixed by an appropriate means (for example, a screw).

[0037]

According to the present invention, when the gap between the tool tip and the gantry becomes too small, the tool tip is retracted, so that the tool tip does not contact the gantry and good friction stir welding can be performed. Is.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a friction stir welding rotary tool according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is an exploded perspective view of the rotary tool for friction stir welding of FIG.

FIG. 4 is an explanatory view showing the operation of the friction stir welding rotary tool of the present invention.

FIG. 5 is an explanatory view showing the operation of the friction stir welding rotary tool of the present invention.

[Explanation of symbols]

1 Friction stir welding equipment 20 mounts 30 plate materials 200 Rotating tool for friction stir welding 210 Cylindrical member 212 Cylindrical part 213 screw 215 groove 230 Tool member 231 Small diameter part 233 Large diameter part 236 Cylindrical part 240 Center member 241 Second small diameter part 244 Detent 247 base 250 spring 260 fixture

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazunari Fukuyori             Hitachi-Kasa, 794 Higashi-Toyoi, Kudamatsu City, Yamaguchi Prefecture             Inside Toki Kogyo Co., Ltd. F-term (reference) 4E067 BG00 CA01

Claims (12)

[Claims] 1. A large-diameter portion has a first small-diameter portion at a tip thereof, and a second small-diameter portion is projected from a tip of the first small-diameter portion, and the second small-diameter portion is provided with the first small-diameter portion. Using a tool that can be expanded and contracted with respect to the small diameter part, insert the small diameter part into the plate material placed on the mount, and insert the tip of the small diameter part up to the vicinity of the mount, and apply it in the axial direction of the small diameter part. A friction stir welding method, comprising: moving the tool while rotating the tool in a state in which the small diameter portion can expand and contract toward the large diameter portion by a load. 2. The friction stir welding method according to claim 1, wherein the tip of the first small diameter portion is inserted into the plate material with a target position being in contact with the gantry. 3. The friction stir welding method according to claim 1, wherein the retreating is performed by the tip of the first small diameter portion coming into contact with the gantry. 4. The friction stir welding method according to claim 1, wherein the second small-diameter portion penetrates the first small-diameter portion and the large-diameter portion. 5. The friction stir welding method according to claim 1, wherein the second small-diameter portion is pressed toward the first small-diameter portion by a spring. 6. A tubular member, a tool member having a first small diameter portion at the tip of the large diameter portion, the large diameter portion being fixed to an end portion of the tubular member, and a center of rotation of the tool member. A center member having a second small diameter portion inserted into a provided through hole and having a tip protruding from the tip of the first small diameter portion; and a tip of the second small diameter portion from the tip of the first small diameter portion. A rotary tool for friction stir welding, comprising: a spring that presses the center member in a protruding direction. 7. The rotary tool for friction stir welding according to claim 6, wherein the spring is arranged in the tubular member. 8. The rotary tool for friction stir welding according to claim 7, wherein one end of the spring is in contact with the center member and the other end is in contact with a fixing member fixed to the tubular member, The fixing metal fitting is screwed and fixed to the tubular member, and a part of the fixing member in the axial direction is in contact with a part of the tubular member in the axial direction. Rotating tool for joining. 9. The rotary tool for friction stir welding according to claim 6, wherein the large diameter portion and the first small diameter portion are provided from one member, and the tool member is screwed to the cylindrical member. And a part of the tool member in the axial direction is in contact with a part of the cylindrical member in the axial direction. 10. The rotary tool for friction stir welding according to claim 6, wherein the diameter of the second small diameter portion protruding from the first small diameter portion is smaller than the through diameter of the hole. Rotary tool for friction stir welding. 11. The rotary tool for friction stir welding according to claim 6, wherein the second small-diameter portion has a linear outer surface in the axial direction. 12. The rotary tool for friction stir welding according to claim 6, wherein a part of the center member is included in a cylindrical portion of an end portion of the tubular member, and the cylindrical portion extends in a radial direction. A rotary tool for friction stir welding, characterized in that there is a groove, and the center member has a detent portion that enters the groove.