JP2007222925A - Friction stirring and joining method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a friction stirring and joining method capable of maintaining the high strength of a joined part without generating any crack or cavity defect in a metallic member having the lower softening temperature when joining dissimilar material having different softening temperature by using a friction stirring and joining tool. <P>SOLUTION: In a method for performing the overlap-joining of plate parts 3 and 2 of first and second metallic members having different softening temperature, a groove 5 is formed in a joined portion of the plate part of the second metallic member 2 having the higher softening temperature; and a fore end of a probe 6a of a friction stirring and joining tool is inserted in the groove 5 through a plastic flow part while the plastic flow of a part facing the groove 5 of the first metallic member 3 having the lower softening temperature is formed by the friction stirring and joining tool 6. The pushing force for pushing the first metallic member 3 subjected to the plastic flow by rotating the probe while inserting the fore end of the probe in the groove 5 is generated, and a plastic-flow material 3a is filled in the groove 5 and cooled and solidified. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In the present invention, when dissimilar metal members having different softening temperatures are overlapped and joined by the friction stir welding method, strong joining is achieved without causing void defects or cracks in the metal member having a higher softening temperature. The present invention relates to a friction stir welding method capable of forming a part.

  In general, the friction stir welding method for joining two joining members arranged in a butted state or a superposed state is one of the solid phase joining methods, and is rotated to the butted portion or the superposed portion of the joined member. Insert the probe, soften the contact part between the probe and the shoulder with frictional heat, plastically flow while stirring, and cool and solidify the plastic flow part while moving the probe along the abutting part or overlapping part. Are to be joined.

Since such a friction stir welding method is solid phase bonding, it is not limited by the type of material of the joining member, or due to thermal distortion at the time of joining as compared with fusion welding methods such as MIG, TIG, laser welding, etc. There are advantages such as less deformation.
However, the application range of the material of the joining member is limited to a material that easily plastically flows at a low temperature, such as Al and Cu, and application to a hardly plastic fluid material such as a steel material is limited.

  If the probe is applied to a material with a high softening temperature such as a steel material, the probe may be damaged. Therefore, a friction between a material that is plastically flowable at a low temperature such as Al or Cu and a material that is difficult to plasticize such as a steel material. Joining by the stir welding method is likely to cause a joining defect, and it is difficult to obtain a sound joint. Therefore, various devices have been tried for joining methods of dissimilar metal members.

  For example, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2003-266183), when refractory plastic flow materials are butt-joined by a friction stir welding method, an intermediate member that easily plastically flows is interposed on the butt-joint surface. A concave portion is formed on the abutting surface on the plastic fluid material side, the probe of the friction stir tool is pressed onto the intermediate member, the probe is inserted into the intermediate member while friction stirring, and the material of the intermediate member follows the concave portion. A method of plastic flow is disclosed.

  Further, in Patent Document 2 (Japanese Patent Application Laid-Open No. 2004-42117), when different materials are butt-joined, a probe is inserted into one plastic-flowable member side near the butt surface, and the other difficult plasticity is inserted. A probe is not inserted into the flow member, and only the member on the side where the probe is inserted is plastically flowed, so that diffusion of atoms at the bonding interface is promoted by plastic flow, and diffusion bonding is performed. In FIG. 5 of Patent Document 2, a concave portion is provided on the abutting surface on the hardly plastic fluid member side, and a mechanical fluid is applied by the wedge effect by introducing the plastic fluidized member into the concave portion. A technique is disclosed.

  Further, in Patent Document 3 (Japanese Patent Laid-Open No. 2005-288525), when metal members having different materials and hardness are overlapped and point-joined, a convex jig is disposed on the metal member side having low hardness, By placing the concave jig on the high metal member side and inserting the convex portion of the convex jig from the surface side of the metal member with low hardness into the point-joined part, 2 in the recess of the concave jig. A method is disclosed in which after a seed metal is pushed in, the rotation of the convex jig is started, and a metal member having low hardness is plastically flowed to bond them together.

A reaction plate for a conventional linear motor car is composed of a primary iron core and a secondary core corresponding to the primary side of the carriage, a secondary conductor, and a pedestal that horizontally supports them. The secondary conductor through which the eddy current flows is integrally coupled to the upper side of the secondary iron core constituting the magnetic path of the linear motor.
The secondary conductor is usually made of aluminum or copper, and since the material is different from that of the secondary core, they cannot be joined together by welding. Therefore, the conventional explosive bonding method or crimping method is used, and the secondary core and base are also used. These were fillet welded in order to prevent misalignment.

  Alternatively, as disclosed in Non-Patent Document 1 (Kawasaki Steel Technical Report Vol.22 No.3 1990), a method of joining a secondary conductor and a secondary iron core by an anchor bond method has also been performed. In the conventional joining method, dovetail grooves, which have been difficult in the past hot rolling, are formed on the surface of flat steel, and the protrusions of the aluminum plate or copper plate are filled into the dovetail grooves by plastic deformation and joined. Is.

JP 2003-266183 A JP 2004-42117 A (paragraph [0023], FIG. 5) JP 2005-288525 A Kawasaki Steel Technical Report Vol. No. 22 3 1990

  However, in the method disclosed in Patent Document 1, there is a possibility that the shoulder portion above the probe that rotatably supports the probe hits the surface of a hardly plastic fluid material such as a steel material and breaks. Further, since the probe is not inserted into the recess provided on the abutting surface, the plastically flowed intermediate member cannot easily enter the recess. Further, even if the plastic-fluided intermediate member enters the recess, the shoulder portion hits the surface of the hardly plastic fluid material as described above, so that a pressing force can be applied to the plastic-fluided intermediate member. Therefore, there is a problem that a cavity defect or a crack is generated inside the intermediate member and the strength is lowered.

  In addition, the method disclosed in Patent Document 2 covers the surface of the hardly plastic fluid member that the shoulder portion contacts with a member that is made of the same material as the material that easily plastically flows. 2, since the probe is not inserted into the concave portion provided on the abutting surface, the plastically flowed member does not easily enter the concave portion, and even if the plastically flowed intermediate member enters the concave portion, Along with that, there is a problem that void defects and cracks are generated inside the intermediate member, and the strength is lowered.

  In addition, the method disclosed in Patent Document 3 is inserted into a dissimilar metal member overlapped with a convex jig and plastically deformed. Therefore, a large load may be applied to the convex jig, which may damage the convex jig. is there. Also, since different types of metal members with different hardness are deformed in a superposed state, the metal member with the lower hardness is pressed and the film shape cannot be maintained, and a metal with low hardness is formed around the convex jig. There is a problem that burrs made of members are formed.

  Moreover, since a considerably strong tensile force acts on the reaction plate for the linear motor car from the vehicle side, the secondary conductor may be peeled off from both ends in the longitudinal direction. Conventional bonding methods such as the adhesion method, the pressure bonding method, and the anchor bond method disclosed in Non-Patent Document 1 require a large-scale apparatus and cannot be easily constructed. Conventionally, the secondary iron core and the gantry are joined by fillet welding, but there is a problem that a crack is generated in the fillet welded portion by a strong tensile force from the vehicle.

In the present invention, in view of the problems of the prior art, when different materials having different softening temperatures are joined using a friction stir tool, the metal member having a lower softening temperature can be joined without generating cracks or void defects. It aims at proposing the joining method which can keep the intensity | strength of a part high.
In addition, the purpose of the present invention is to realize a friction stir method that can be achieved without causing structural defects in the joint by a simple method, particularly the joining of the secondary iron core and the secondary conductor constituting the reaction plate for a linear motor car. To do.

In order to achieve the above object, the friction stir welding method of the present invention comprises:
In the method of laminating and joining the plate-like portions of the first and second metal members having different softening temperatures,
A groove is provided at the joint portion of the plate-like portion of the second metal member having the higher softening temperature,
While the portion of the first metal member having the lower softening temperature facing the groove is caused to generate plastic flow by the friction stir tool, the tip of the probe of the friction stir tool is passed through the plastic flow portion to the inside of the groove. Inserted into
The probe is rotated while the tip of the probe is inserted into the groove to generate a pushing force to push the plastic flowed first metal member into the groove, and the plastic flow member is filled into the groove to be cooled and solidified. It is.

  In the present invention, the probe of the friction stir tool uses a structure that generates a pushing force by which the plastic fluid material made of the first metal member is pushed into the groove by rotating inside the groove. . For example, a screw part is provided on the probe peripheral surface, or the probe is formed in a conical shape with a tapered inclination. In the case where a screw portion is provided on the probe peripheral surface, the probe is rotated clockwise when the left screw is used, and the probe is rotated counterclockwise when the right screw is used.

  Since the plastic fluidized material does not shrink when cooled and solidified, no void is generated in the groove. Therefore, the strength of the joint is maintained. Further, if the groove has a wedge shape whose area increases toward the back, the plastic fluidized material is filled in the groove, and when it is cooled and solidified, the bonding force of the joint is strengthened by the wedge effect.

  Further, when the plastic fluidized material is filled in the groove, the surface of the first metal member is recessed by the amount filled in the groove. Therefore, it is possible to prevent a dent from occurring by previously filling a replenisher of the same material as the first metal member in the groove. Alternatively, a convex portion having a width corresponding to the width of the groove and a volume corresponding to the volume of the groove is provided on the upper surface or the lower surface of the portion facing the groove of the first metal member, or the groove of the first metal member. If a replenishment material made of a first metal material having a width corresponding to the width of the groove and a volume corresponding to the volume of the groove is previously installed on the upper surface of the portion facing the surface, the surface of the first metal member There is no dent.

  Further, the groove can be formed in an extended line shape or a spot shape. When the groove is formed in an extended linear shape, the tip of the probe of the friction stir tool is placed on the portion of the first metal member facing the groove while causing plastic flow with the friction stir tool. A linear joint can be continuously formed by inserting the friction stir tool along the groove while the probe is inserted into the groove through the plastic flow site and the probe is inserted into the groove. it can.

Further, when the groove is formed in a spot shape, a female thread is formed on the inner surface of the groove, and a plastic flow material made of a first metal member is filled so as to form a male thread for the female screw. When the material is cooled and solidified, the first metal member and the second metal member are in a bolted state, and a strong bonding force can be obtained.
Further, the thickness of the first metal member is reduced by the amount corresponding to the dent amount of the first metal member due to plastic flow of the first metal member to the required plate thickness and filling the groove. An allowance may be added and set, and after the friction stir welding, the shaving allowance may be cut.

  The present invention is particularly suitable for application to the production of a reaction plate for a linear motor car. That is, the first metal member is a secondary conductor of a reaction plate for a linear motor car, and the second metal member is a frame of the reaction plate or a secondary iron core attached to the frame, the frame or the secondary iron core. A joining portion can be formed by forming a linear or spot-like groove on the overlapping surface of the secondary conductor and filling the plastic fluid material of the secondary conductor into the groove. This eliminates the need for large-scale equipment and construction as in the prior art, such as the explosive bonding method, pressure bonding method, and anchor bond method.

  Further, a plurality of linear grooves are provided over the entire length in the longitudinal direction of the gantry or secondary iron core, and a plurality of spot-like grooves are provided between the linear grooves at both longitudinal ends of the gantry or the secondary iron core. If the linear groove and the spot-like groove are filled with the plastic fluid material of the secondary conductor, the joint strength at both ends of the secondary conductor that can be easily peeled off can be increased.

  According to the method of the present invention, a groove is provided at the joint portion of the plate-like portion of the second metal member having a high softening temperature, and the portion facing the groove of the first metal member having the lower softening temperature is used for friction stirring. The plastic flow is generated by inserting the tip of the probe of the friction stir tool into the groove through the plastic flow portion and rotating the probe while inserting the tip of the probe into the groove while generating plastic flow with the tool. The metal fluid member is pushed into the groove, and the plastic fluidizing material is filled in the groove. Therefore, the plastic fluidizing material has a sufficient pushing force into the groove, and the groove inside the groove. Thus, a sufficient stirring force can be applied to form a joint having a sufficient strength.

  Further, unlike the conventional method, cracks and cavity defects do not occur in the first metal member having a low softening temperature due to filling of the plastic fluid material into the groove, and preferably, the same material as the first metal member is used. The replenishing material is filled in the groove in advance, or a convex portion made of the first metal member is provided on the upper surface or the lower surface of the portion facing the groove of the first metal member, thereby entering the groove of the plastic fluid material. It is possible to prevent dents associated with filling.

Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this embodiment are not intended to limit the present invention to that only, unless otherwise specified.
FIG. 1 (a) is a sectional elevation view of the first embodiment in which the present invention is applied to the production of a reaction plate for a linear motor car (cross section AA in FIG. 1 (b)), and FIG. 2 is an explanatory view showing the friction stir welding method in the first embodiment, and FIG. 3A is a sectional elevation view of the second embodiment of the present invention similarly applied to the production of the reaction plate ((b)). (B-B cross section), (b) is also a plan view, and (c) is an enlarged view of part C of (a).

  4A is a sectional elevational view (DD sectional view of (b)) of the third embodiment of the present invention applied to the production of the reaction plate, and FIG. 4B is a plan view of the same. ) Is an enlarged view of part E in FIG. 5A, and FIG. 5A is a sectional elevation view of the fourth embodiment of the present invention applied to the production of the reaction plate (FF sectional view in FIG. 5B). (B) is a plan view, (c) is an enlarged view of the G portion of (a), (d) is an enlarged view of the H portion of (a), and FIGS. FIG.

  In FIG. 1 showing the first embodiment, a linear motor car reaction plate 1 includes, as basic components, a secondary iron core 2 and a secondary conductor 3 corresponding to a primary iron core and a primary conductor on a carriage side, and those. A supporting frame 4 is provided. A secondary conductor 3 through which an eddy current flows is integrally coupled to the upper side of the secondary iron core 2 constituting the magnetic path of the linear motor. The gantry 4 is fixed to sleepers (not shown) by fixing means (not shown).

  In this embodiment, the gantry 4 and the secondary iron core 2 are made of mild steel (SS400), and the secondary iron core 2 attached to the top surface of the gantry 4 is attached to the gantry 4 by fillet welding w. The secondary conductor 3 made of aluminum or copper is joined by the friction stir welding method shown in FIG. The secondary iron core 2 is provided with a plurality of linear grooves 5 in parallel in the longitudinal direction. The linear groove 5 has a tapered wedge shape with a larger area at the bottom.

  In FIG. 2, the friction stir tool 6 is pressed against the surface of the secondary conductor 3 facing the linear groove 5 of the secondary iron core 2. The friction stir tool 6 includes a probe 6 a and a shoulder 6 b that rotate together, and rotates in the r direction while applying a pressing force f to the surface of the secondary conductor 3. A male thread 7 is formed on the peripheral surface of the probe 6a. When the friction stir tool 6 rotates in the clockwise direction, a left-hand thread is cut, and when it rotates in the counterclockwise direction, a right-hand thread is cut. When the friction stir tool 6 is rotated by such a configuration, a pressing force g for pressing the plastic-flowing secondary conductor material into the linear groove 5 is given.

  When the friction stir tool 6 is pressed against the surface of the secondary conductor 3 facing the linear groove 5 and rotates in the r direction, the secondary conductor material in contact with the probe 6a is in a plastic flow state. Therefore, the probe 6 a is further inserted while rotating the friction stir tool 6 until the tip of the probe 6 a enters the inside of the groove 5. Since the external thread 7 is formed on the peripheral surface of the probe 6a, a pushing force g for pushing the plastically flowed secondary conductor material into the groove 5 is generated, and the action causes the inside of the linear groove 5 to be secondary. Filled with conductive material. At this time, the secondary iron core 2 does not plastically flow.

When the secondary conductor material filled in the linear groove 5 is cooled and solidified, the secondary iron core 2 and the secondary conductor 3 are strengthened by the wedge effect of the secondary conductor material filled in the wedge-shaped groove 5. Can be combined.
Conventionally, the secondary iron core 2 and the secondary conductor 3 made of aluminum or copper are made of different materials, so the explosion bonding method, the pressure bonding method or the anchor bond method disclosed in Non-Patent Document 1 is adopted. However, the explosive deposition method required large-scale equipment and produced a loud explosion sound, and the construction was troublesome. Also, the crimping method and the anchor bond method required large-scale equipment as well, and the construction was troublesome. By adopting the friction stir welding method as in the present embodiment, it is possible to easily join with a simple device and to improve the strength of the joint.

  Further, according to the present embodiment, only one secondary conductor material 3 is plastically flowed, the secondary iron core 2 is not plastically flowed, and the plastic fluid material 3a of the secondary conductor 3 is provided on the secondary iron core 2. Therefore, even if the softening temperatures of the two materials are different, it is not necessary to force the secondary iron core 2 having a high softening temperature to plastically flow, and the friction stir tool 6 may be damaged. There is no need for big power.

  Further, in this embodiment, a recess having a capacity corresponding to the plastic fluid filled in the linear groove 5 may be generated on the surface of the secondary conductor. By applying pressure with the shoulder 6b of the stirring tool 6 or adjusting the insertion depth of the probe 6a, there is no crack or void defect inside the plastic fluidized material as in Patent Document 1 or 2.

In addition, since the threaded portion 7 is provided on the probe surface and the pushing force g for pushing the plastic fluid material into the linear groove 5 is applied, the plastic fluid material can be reliably filled into the linear groove 5, Since the tip of the probe 6a is inserted into the linear groove 5 and rotated, a sufficient agitation force works in the groove, so that a joint having sufficient strength can be obtained without causing cracks or voids. Can be formed. Further, since the plastic fluidized material does not shrink even when cooled and solidified, no voids are generated in the groove even after cooling and solidifying.
In this embodiment, the linear grooves 5 are formed at equal intervals in the longitudinal direction of the gantry 4, and a strong joint is formed by the linear grooves 5, so that the secondary conductor 3 is coupled to the secondary core 2. Power will be strong.

  In this embodiment, the male thread 7 is formed on the peripheral surface of the probe 6a as a configuration for applying the pushing force g of the plastic fluid material to the inside of the linear groove 5, but as another means for forming the pushing force. The probe 6a may have a tapered conical shape, and a pressing force may be applied to the inside of the linear groove 5 along the inclined peripheral surface of the conical shape.

  Next, a second embodiment of the present invention will be described with reference to FIG. This embodiment is an embodiment when applied to a reaction plate for a linear motor car as in the first embodiment. However, the reaction plate 11 of this embodiment eliminates the secondary iron core, and the reaction plate base 13 is provided. In this configuration, the secondary conductor is directly joined to the substrate. 3A is a cross-sectional view taken along the line BB of FIG. 3B, FIG. 3B is a plan view, and FIG. 3C is an enlarged view of a portion C in FIG. The reaction plate 11 is elongated in the longitudinal direction, and has a long side of about 5 m, for example, on a base 13 made of mild steel (SS400), and a secondary conductor 12 made of aluminum or copper is joined and joined. It consists of

  Similar to the first embodiment, a plurality of linear grooves 14 are provided at equal intervals in the longitudinal direction on the upper surface of the gantry 13, and the linear grooves 14 become deeper as in the first embodiment. It has a wedge shape with a wide area. The secondary conductor 12 is placed on the upper surface of the gantry 13 to form an overlapping surface to be joined to each other. The overlapped surface is friction stir welded using the friction stir tool 6 by the same method as shown in FIG. 2 of the first embodiment.

  That is, the friction stir tool 6 is applied to the surface of the secondary conductor 12 facing the linear groove 14 and rotated while applying a pressing force to the secondary conductor 12, thereby causing the secondary conductor 12 to flow plastically. The tip of the probe 6a is inserted into the linear groove 14 while stirring the aluminum or copper material constituting the secondary conductor by inserting the probe 6a into the plastic-flowed secondary conductor 12.

  By rotating the probe 6a in the linear groove 14 in this way, a pushing force for pushing the plastic fluid material into the linear groove 14 is generated, and the plastic fluid material 12a is filled in the linear groove 14. At the same time, by rotating the probe 6a inside the linear groove 14 and sufficiently stirring the plastic fluid 12a filled in the linear groove 14, a joint having high strength can be formed. it can. FIG. 3C shows a state where the plastic fluid material 12 a is filled in the linear groove 14. The operational effects obtained by carrying out such a friction stir welding method are the same as those in the first embodiment.

  In this embodiment, since the secondary iron core is eliminated, there is no need to fillet weld the gantry 4 and the secondary iron core 2 as in the first embodiment, and there is a concern about cracking of the fillet weld. No need to do.

  Next, a third embodiment of the present invention will be described with reference to FIG. The present embodiment is applied to the production of a reaction plate having the same configuration as the second embodiment (that is, the configuration without the secondary iron core), and the shape of the linear groove 21 is different from that of the second embodiment. Differently, other configurations are the same. In addition, about the site | part which has the structure and function same as the said 2nd Example, the code | symbol same as 2nd Example is attached | subjected. In FIG. 4, the linear grooves 21 are the same as the second embodiment in that the linear grooves 21 are linearly arranged in the longitudinal direction of the gantry 13, but the shape of the linear grooves 21 is a wedge shape. Rather, both the opening and the bottom have an elongated rectangular parallelepiped shape having the same area, and an uneven portion 22 extending in the longitudinal direction is provided on the inner surface.

Therefore, when the aluminum or copper plastic fluid 12a that constitutes the secondary conductor 12 is pushed into the linear groove 21, the plastic fluid 12a enters the concavo-convex portion 22, and thus between the gantry 13 and the linear groove 21. A strong bonding force can be exhibited. FIG. 4C shows a state in which the plastic fluid material 12 a is filled in the groove 21.
Other functions and effects are the same as those of the second embodiment.

  Next, a fourth embodiment of the present invention will be described with reference to FIG. Compared with the second embodiment, this embodiment has not only the arrangement of the linear grooves 14 but also the linear grooves arranged at equal intervals in the longitudinal direction of the gantry 13 at both longitudinal ends of the secondary conductor 12. 14, spot-shaped grooves 31 are provided, and friction stir welding is performed at the positions of the linear grooves 14 and the spot-shaped grooves 31.

  The cross-section of the linear groove 14 has a wedge-shaped cross-sectional shape that spreads out in the same manner as in the second embodiment, while the inner surface of the spot-shaped groove 31 has a cylindrical shape and the gantry 13 as shown in FIG. The internal thread 32 is formed in the inner surface. FIG. 5D shows a state where the plastic fluidized material 12b of the secondary conductor 12 has entered the middle portion of the spot-like groove 31 by friction stir welding and has been cooled and solidified.

  In the spot-like groove 31, the plastic fluid 12 b enters the concavities and convexities of the female screw 32 and is cooled and solidified, so that the secondary conductor 12 and the gantry 13 are in the same coupling state as the bolt coupling, and the secondary conductor 12 and the gantry 13 A strong bonding force can be obtained. Both ends in the longitudinal direction of the secondary conductor 12 are particularly easily peeled off from the gantry 13, but by providing not only the linear grooves 14 as in the present embodiment but also the spot-like grooves 31 in which the internal threads 32 are formed on the inner surface, Since a strong bonding force can be generated, there is no possibility that the secondary conductor 12 is peeled off from both ends in the longitudinal direction.

  Next, various modifications of the present invention will be described with reference to FIGS. FIG. 6 to FIG. 10 show the joint portion of the overlapping surface of a member (for example, aluminum) 41 that easily plastically flows and a member 42 that hardly plastically flows. In the present invention, the member 41 that is likely to plastically flow at the joint is plastically flowed by the friction stir tool, and the plastic fluidized material is filled into the groove 43. Although the surface of the member 41 that is likely to plastically flow by a volume corresponding to the filling amount is recessed, in FIG. 6, the convex portion 44 having a volume corresponding to the filling amount is formed on the surface of the member 41 in advance before friction stir welding. As a result, the surface of the member 41 is not dented.

  In FIG. 7, the same convex portion 45 is formed on the lower surface of the member 41 facing the groove 43, and in FIG. 8, the replenishment material 46 made of the same material as that of the member 41 is previously inserted into the groove 43. In FIG. 9, it is possible to prevent the surface of the member 41 from being recessed by placing or sticking the replenishment material 47 made of the same material as the member 41 on the surface of the member 41.

In FIG. 10, the plate thickness of the member 41 is set to a plate thickness obtained by adding the cutting allowance h ₂ corresponding to the filling amount of the plastic fluid material into the groove 43 to the required plate thickness h ₁ , and after joining by the friction stir welding method, Once cause dents on the surface of the member 41 facing the groove 43, by scraping the remaining cutting cash h _2, it is possible to prevent the occurrence of dents.

  According to the present invention, when dissimilar materials having different softening temperatures are joined by the friction stir welding method, only the metal member having the lower softening temperature is frictionally stirred without friction stirring the metal member having the higher softening temperature. Thus, it is possible to provide a friction stir welding method in which a joined portion having excellent joining strength can be easily obtained and there is no crack or void defect inside the plastic fluidized material.

(A) is a sectional elevation view of the first embodiment in which the present invention is applied to manufacture of a reaction plate for a linear motor car (A-A section of (b)), and (b) is a plan view of the same. It is explanatory drawing which shows the friction stir welding method in the said 1st Example. (A) is a sectional elevation view of the second embodiment of the present invention applied to the production of the reaction plate (B-B section of (b)), (b) is a plan view, and (c) is (a). FIG. (A) is a sectional elevation view (DD sectional view of (b)) of the third embodiment of the present invention applied to the production of the reaction plate, (b) is a plan view, and (c) is ( It is the E section enlarged view of a). (A) is a sectional elevation view (F-F sectional view of (b)) of a fourth embodiment of the present invention applied to the production of the reaction plate, (b) is a plan view, and (c) is ( (a) The G section enlarged view of (a), (d) is the H section enlarged view of (a). It is explanatory drawing of the modification of this invention. It is explanatory drawing of another modification of this invention. It is explanatory drawing of another modification of this invention. It is explanatory drawing of another modification of this invention. It is explanatory drawing of another modification of this invention.

Explanation of symbols

1, 11 Reaction plate for linear motor car 2 Secondary iron core 3, 12 Secondary conductor 3a, 12a, 12b Plastic flow material 4, 13 Base 5, 14, 21 Linear groove 6 Friction stirring tool 6a Probe 6b Shoulder part 7 Male screw Part 31 Spot-like groove 22 Concavity and convexity part 32 Female thread part 44, 45 Convex part 46, 47 Supplementary material h1 Necessary plate thickness of the member 41 that easily plastically flows h2 Cutting allowance of the member 41 that easily plastically flows g Pushing force r Rotation direction w Corner Meat weld

Claims (12)

In the method of laminating and joining the plate-like portions of the first and second metal members having different softening temperatures,
A groove is provided at the joint portion of the plate-like portion of the second metal member having the higher softening temperature,
While the plastic metal flow is generated by the friction stir tool at the portion facing the groove of the first metal member having the lower softening temperature, the tip of the probe of the friction stir tool passes through the plastic flow point to the inside of the groove. Inserted into
By rotating the tip of the probe while being inserted into the groove, a pressing force is generated to push the first metal member plastically flowed into the groove, and the plastic fluid is filled into the groove to be cooled and solidified. A friction stir welding method characterized by the above.   2. The friction stir welding method according to claim 1, wherein a pressing force for pressing the plastic-flowed first metal member into the groove is generated by providing a screw portion on the peripheral surface of the probe.   2. The friction stir welding method according to claim 1, wherein a pressing force for pressing the plastic-flowed first metal member into the groove is generated by forming the probe into a tapered and tapered shape. 3.   2. The friction stir welding method according to claim 1, wherein the cross-sectional shape of the groove is a wedge shape whose area is enlarged toward the back of the groove.   2. The friction stir welding method according to claim 1, wherein a replenisher made of the same material as that of the first metal member is filled in the groove in advance.   The convex portion having a width corresponding to the width of the groove and a volume corresponding to the inner volume of the groove is provided on an upper surface or a lower surface of a portion facing the groove of the first metal member. 2. The friction stir welding method according to 1.   A replenisher made of the same material as the first metal material having a width corresponding to the width of the groove and a volume corresponding to the volume of the groove on the upper surface of the portion of the first metal member facing the groove. The friction stir welding method according to claim 1, wherein the friction stir welding method is installed in advance.   The thickness of the first metal member is equal to the necessary plate thickness, and the first metal member is plastically flowed and filled into the groove to correspond to the recess height of the first metal member. 2. The friction stir welding method according to claim 1, wherein the cutting allowance is set by adding, and after the friction stir welding, the cutting allowance is cut. The tip of the probe of the friction stir tool is made to flow while the portion of the first metal member facing the groove is formed into a linear shape and plastic flow is generated by the friction stir tool. Inserted into the groove through the site,
2. The friction stir welding method according to claim 1, wherein a linear joint is formed by moving a friction stir tool along the groove in a state where the tip of the probe is inserted into the groove.   The groove has a spot shape, an internal thread is formed on the inner surface of the groove, and the plastic fluidized material made of the first metal member is filled so as to form an external thread for the internal thread of the groove. Item 2. The friction stir welding method according to Item 1.   The first metal member is a secondary conductor of a reaction plate for a linear motor car, and the second metal member is a frame of the reaction plate or a secondary iron core attached to the frame, the frame or the secondary A linear or spot-like groove is formed on the overlapping surface of the iron core and the secondary conductor, and a joining portion is formed by filling the plastic fluid material of the secondary conductor in the groove. The friction stir welding method according to claim 1. A plurality of linear grooves are provided over the entire length in the longitudinal direction of the gantry or the secondary iron core, and a plurality of spot-like grooves are provided between the linear grooves at both longitudinal ends of the gantry or the secondary iron core. Forming,
2. The friction stir welding method according to claim 1, wherein the linear groove and the spot-like groove are filled with a plastic fluidized material of a secondary conductor.

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