JP2015145013A - Friction stir welding method and friction stir welding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a friction stir welding method and a friction stir welding device which does not require to consider abrasion of a bonding tool in particular, and can improve bondability or can improve appearance after bonding, when performing friction stir bonding.SOLUTION: A bonding tool comprises a bonding auxiliary material which subjects a member to be bonded to friction agitation by coming into sliding contact with the member to be bonded and a friction stir bonding tool main body which is rotated and driven, is separably connected with a bonding auxiliary material and is connected with the bonding auxiliary material and is rotated together with the bonding auxiliary material during friction stir welding process. Therein, a pressing force of the bonding auxiliary material on a sliding surface of the bonding auxiliary material and the member to be bonded is generated or adjusted by utilizing deformation of the bonding auxiliary material during the friction stir welding process and, after completion of the friction stir welding process, the bonding auxiliary material is separated from the friction stir bonding tool main body.

Description

  The present invention relates to a friction stir welding method and a friction stir welding apparatus, and is particularly suitable for friction stir welding from the inside of a hole formed in a member to be joined, or when spotting friction stir welding of stacked plate materials. The present invention relates to a friction stir welding method and a friction stir welding apparatus.

  Joining technology using Friction Stir Processing (FSP) or Friction Stir Welding (FSW: Friction Stir Welding) rotates a cylindrical joining tool with a protrusion (pin or probe) at the tip. The material is softened by the frictional heat generated between the projection of the welding tool and the material, and the projection of the welding tool is pressed into the material. This is a joining technique that unifies the joint between two materials by plastically flowing and kneading the material around the projection of the joining tool by rotational force.

  In the FSP bonding technique, the bonded portion can be metal-bonded by stirring metal atoms around the softening temperature of the metal without reaching the melting point of the metal. The metals to be joined can be the same or different metals. Furthermore, since the FSP joining technique is a stir welding in the vicinity of the softening temperature of the metal, the joining strain is small and a solidification cooling process is unnecessary. That is, in the FSP joining technology, the joining interface is joined by the metal softening phenomenon caused by frictional heat and the dynamic energy of the rotation of the joining tool. It does not go through the coagulation process. For this reason, there is no coarsening of the crystal at the bonding interface, and a fine metal structure is obtained at the bonding interface without generating an intermetallic compound. FSP joining technology can be joined only with a joining tool, and since the joint is not heated as compared with welding or the like, no thermal strain stress is generated, so recently, metal joints including joining of automobile parts are included. It is often used for joining.

  FSP joining technology includes a joining method in which joining is performed by rotating a joining tool having projections along the abutting surfaces (joining lines) of two metal plates, and a metal plate in which joining tools having projections are superimposed. There is a method of pressing from one side and joining in a spot manner.

  FSP joining technology is premised on the friction between the joining tool and the member to be joined, so the wear of the tip of the joining tool (the part to be joined and the friction contact part) is inevitable, The welding tool needs to be replaced. Since the joining tool is made of a wear-resistant material, it is relatively expensive, and the replacement of the joining tool causes a reduction in workability.

Conventionally, as countermeasures against wear of a welding tool, for example, there are techniques described in Patent Document 1 and Patent Document 2.
In Patent Document 1, a joining tool is divided into a joining tool that is immersed in a member to be joined and a tool holder that is detachably attached to the tip part, and only the joining tool is made of an abrasion-resistant material. It is disclosed that the cost spent for friction stir welding can be reduced by manufacturing and exchanging.
In Patent Document 2, by providing the friction stir processing apparatus with a tool regeneration mechanism that grinds the tip of a tool worn by friction stir processing with a grindstone, even if the tool is worn during friction stir processing, It is disclosed that the tool replacement frequency can be reduced by restoring and restoring the previous shape such as wear.

JP 2006-212657 A JP 2013-212540 A

Conventionally, including the Patent Document 1 and Patent Document 2, when the joining tool (or processing tool) is worn, the joining tool is replaced (partially replaced) or regenerated.
The present inventors have reviewed the welding tool in the conventional friction stir welding technique and have come up with a welding tool based on a new concept different from the conventional welding tool. Then, the present inventors have found that by using a joining tool based on a new concept, friction stir welding can be applied to various joining parts and various joining sites that are difficult to apply with conventional joining tools.

  An object of the present invention is to improve the joining property when performing friction stir welding of various joining parts and various joining parts using a joining tool based on a new concept that does not particularly consider the wear of the joining tool. An object of the present invention is to provide a friction stir welding method and a friction stir welding apparatus capable of improving the appearance after joining.

  The present invention relates to a joining tool, which is slidably contacted with a member to be joined and friction stirs the member to be joined, is rotationally driven and is detachably connected to the joining aid, and friction stir welding. The friction stir welding tool main body is connected to the joining aid and rotates together with the joining aid during the process, and the joining aid is added to the sliding surfaces of the joining aid and the joined member during the friction stir welding process. The pressure is generated or adjusted using deformation of the joining auxiliary material, and after the friction stir welding process is completed, the joining auxiliary material is separated from the friction stir welding tool body. When the member to be joined is rotated and the member to be joined and the joining auxiliary material are brought into sliding contact with each other, the friction stir welding tool body is held so as not to rotate. To prevent rotation of the joining aid. The deformation of the joining auxiliary material occurs, for example, by causing a relative displacement between the friction stir welding tool main body (joining auxiliary material) and the member to be joined by lowering the friction stir welding tool main body (joining auxiliary material). Let

According to the present invention, it is possible to perform friction stir welding without particularly considering wear of the welding tool. In other words, the present invention, in other words, uses the joining auxiliary material as a single-piece joining tool constituent member in one friction stir welding, so there is no need to consider the wear of the joining tool in particular.
Moreover, friction stir welding can be applied to various joining parts and various joining parts by making a joining auxiliary material into a suitable form according to joining parts and joining parts. For example, when the member to be joined is friction stir welded from the inside of the hole, the pressure of the joining auxiliary material on the sliding surface between the joining auxiliary member and the member to be joined is generated using the deformation of the joining auxiliary material. Since the adjustment is performed, friction stir welding can be performed under an appropriate pressure, and the bondability can be improved. In addition, for example, when spot-stirring the laminated plate materials, the joining auxiliary material is made into a large disk shape as compared to the friction stir welding tool body, and using the deformation of this disk-shaped joining auxiliary material, By generating or adjusting the pressing force on the sliding surface between the member to be joined and the joining auxiliary material, the pressing force does not act locally on the member to be joined, so that local deformation of the member to be joined is suppressed and friction stirring is performed. Bonding can be performed, and the appearance after bonding can be improved.
Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is sectional drawing in the time of completion of friction stirring of the joining method in Example 1 of this invention. It is process explanatory drawing of the joining method in Example 1 of this invention. It is process explanatory drawing of the joining method in Example 1 of this invention. It is process explanatory drawing of the joining method in Example 1 of this invention. It is process explanatory drawing of the joining method in Example 2 of this invention. It is process explanatory drawing of the joining method in Example 2 of this invention. It is a figure which shows an example of the joining auxiliary material used for Example 3 of this invention. It is process explanatory drawing of the joining method in Example 3 of this invention. It is process explanatory drawing of the joining method in Example 3 of this invention. It is process explanatory drawing of the joining method in Example 4 of this invention. It is process explanatory drawing of the joining method in Example 4 of this invention. It is process explanatory drawing of the joining method in Example 5 of this invention. It is process explanatory drawing of the joining method in Example 5 of this invention. It is process explanatory drawing of the joining method in Example 6 of this invention. It is process explanatory drawing of the joining method in Example 6 of this invention. It is process explanatory drawing of the joining method in Example 7 of this invention. It is process explanatory drawing of the joining method in Example 7 of this invention. It is process explanatory drawing of the joining method in Example 7 of this invention. It is process explanatory drawing of the joining method in Example 7 of this invention. It is a figure which shows an example of the friction stir welding tool main body used for Example 7 of this invention. It is process explanatory drawing of the joining method in Example 8 of this invention. It is process explanatory drawing of the joining method in Example 8 of this invention. It is process explanatory drawing of the joining method in Example 8 of this invention. It is process explanatory drawing of the joining method in Example 8 of this invention. It is process explanatory drawing of the joining method in Example 9 of this invention. It is process explanatory drawing of the joining method in Example 9 of this invention. It is process explanatory drawing of the joining method in Example 9 of this invention. It is process explanatory drawing of the joining method in Example 9 of this invention. It is a figure which shows an example of the joining apparatus used for the joining method of each Example of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

First, the background to the idea of the present invention will be described.
Friction stir welding has been put to practical use as a means of joining relatively large structures such as vehicles and bridges, but in the future, small and thin parts such as parts of equipment and devices (especially electronic device mounting devices) will be used. Adoption is expected to progress in joining of joining members and joining of various shapes.
Since the friction stir welding tool rotates and slides directly with respect to the member to be joined, it involves wear. Furthermore, when the friction stir welding tool and the member to be joined are directly rotated and slid, adhesion and deposition (adhesion or adhesion) of the material of the member to be joined to the surface of the friction stir welding tool occurs. As a result, when continuous friction stir welding is performed, bondability (bonding force and the like) and bonding accuracy are reduced. For this reason, in the case of continuous joining, it is necessary to replace the friction stir welding tool or perform maintenance work (such as deposit removal work on the surface of the welding tool). Replacing and maintaining the friction stir welding tool will greatly reduce productivity (working efficiency). In addition, the friction stir welding tool is a relatively expensive tool, and the friction stir welding tool tends to be specialized and expensive, and the consumption of the friction stir welding tool leads to higher cost of the joining work.

  These issues are the effects of wear of the friction stir welding tool and adhesion of foreign matter to the tool surface when a relatively large workpiece can be joined or a high-strength tool material can be selected for the workpiece. Small and not a big problem.

  However, it becomes an important issue when friction stir welding is performed on miniaturized members to be joined or diversified joining sites. For example, when joining a large number of miniaturized members to be joined such as parts of equipment / devices, it is necessary to perform uniform friction stir welding on a large number of parts (members to be joined). It becomes difficult to wear when the material of the member to be joined adheres to the friction stir welding tool. If the friction stir welding tool is replaced for each joint, uniform friction stir welding can be performed on a large number of parts. This leads to higher costs. In addition, for example, when it is difficult to give the tool material relatively sufficient strength due to the high-strength members to be joined, the wear of the friction stir welding tool should be dealt with for each joint (exchange and maintenance). It is necessary to consider.

  Therefore, the present inventors have made various studies and arrived at a friction stir welding tool based on a new concept different from the conventional friction stir welding tools.

  As a merit of friction stir welding, if there is basically a friction stir welding tool (cylindrical welding tool with a protrusion at the tip) and means for driving it, dissimilar metal joining can be performed without using additional parts and auxiliary materials. It is mentioned that various metals including it can be joined. The joining tool is divided into a joining tool that immerses in the member to be joined and a tool holder that is detachably attached to the tip, and only the joining tool is manufactured and replaced with wear-resistant material. However, in addition to the joining tool and its driving means, additional parts and auxiliary materials are basically unnecessary.

  Although the present inventors are contrary to the merit of friction stir welding in which an additional part and an auxiliary material are not required, the inventors investigated performing friction stir welding using a welding auxiliary material. Then, the present inventors are driven to rotate by the friction stir welding tool body as a constituent member of the friction stir welding tool that frictionally stirs the member to be joined by rotating and sliding contact with the member to be joined. In addition, after the friction stir welding, the friction stir welding is separated from the main body of the friction stir welding, that is, the friction stir welding is performed without considering the wear of the welding tool, etc. I found out that it was possible to do.

  In this friction stir welding, the joining auxiliary material rotates and makes sliding contact with the members to be joined to generate frictional heat, and a friction stirring layer is formed by the materials of the members to be joined and both the members to be joined and the joining aid material. Thus, the members to be joined are joined together. The friction stir welding tool body does not make sliding contact with the member to be joined. In other words, a joining auxiliary material is interposed between the friction stir welding tool main body and the member to be joined. The friction stir welding tool main body mainly plays the same role as a wrench or driver that transmits rotational motion and pressure to the welding auxiliary material, and basically does not need to consider wear, and does not need to consider replacement due to deterioration. This friction stir welding tool body is configured as standardized and generalized as much as possible as a rotation / pressure transmission tool.

  Since the joining auxiliary material only needs to be able to friction stir the member to be joined, it may be the same material as the member to be joined and the same degree of hardness, and does not need to have high wear resistance. Further, the friction stir welding tool main body does not need to have high wear resistance, and it is not necessary to use an expensive material or perform processing. Therefore, the friction stir welding tool can be configured at a low cost.

  In addition, as a joining aid, it is possible to ensure the fitting state of the friction stir welding tool body and the joining aid material, and it is difficult to adhere to the friction stir welding tool body or easily from the friction stir welding tool body. It is desirable to make it easy to desorb.

  When performing continuous friction stir welding on a large number of parts, the welding tool is divided into a welding tool that immerses in the member to be joined and a tool holder that detachably attaches this welding tool to the tip. However, it is conceivable to manufacture and replace only the welding tool with a wear-resistant material. In this case, it is necessary to securely attach the welding tool to the tool holder before starting the friction stir welding. At the time of completion, the welding tool is firmly attached to the tool holder and separated from the member to be joined. That is, it is necessary to securely attach and detach the joining tool to / from the tool holder, and it takes time to replace the joining tool. On the other hand, in the case of the present invention, since the joining auxiliary material is attached to the member to be joined in advance or after the friction stir welding is completed, the joining auxiliary material is separated from the friction stir welding tool body. It is only necessary to secure a fitting state between the friction stir welding tool main body and the joining auxiliary material during the process, and the joining work of supplying the joining auxiliary material is easier than the replacement work of the joining tool. That is, when performing friction stir welding continuously on a large number of parts, the friction stir welding tool main body only needs to be fitted to the welding auxiliary material, and the work corresponding to the welding tool replacement work is omitted. be able to. Further, in the present invention, the friction stir welding tool main body does not slide directly into contact with the member to be joined, so that the maintenance work for removing deposits from the surface of the joining tool as in the prior art is unnecessary. Therefore, in the present invention, it is possible to greatly improve the productivity when performing friction stir welding on a large number of parts continuously.

  Further, in the present invention, friction stirrer occurs even between the joining auxiliary material and the member to be joined, but even when the joining auxiliary material is left on the member to be joined after the friction stir welding, the main joining between the members to be joined is as follows. This is done by friction-stirring the members to be joined together with a joining auxiliary material. The main joining / fixing of the members to be joined is not performed by the friction stir between the joining auxiliary material and the member to be joined, and the friction stirring between the joining auxiliary material and the member to be joined is not the friction between the members to be joined. Supports stir welding.

  Further, when friction stir welding is continuously performed on a large number of parts, in the present invention, the joining auxiliary material is friction stir with the member to be joined, and the joining auxiliary material is used up for one friction stir welding. Since it is a member, it is not necessary to consider the adherence of the member to be joined to the surface as in a conventional joining tool, and the joining properties of friction stir welding in a large number of parts can be made uniform.

  As described above, the joining tool of the present invention has a new concept in which the joining auxiliary material is a constituent member of the joining tool. Then, the present inventors pay attention to the fact that the joining auxiliary material is separated from the friction stir welding tool main body, and that it is a single-use member. It has been found that friction stir welding can be applied to various joining parts and various joining sites by adopting an appropriate form.

  That is, in the present invention, the friction stir welding tool main body may be detachably connected to the joining auxiliary material so that a rotational force and a pressing force can be applied to the joining auxiliary material. Since it can be attached to the member to be joined in advance, and after the friction stir welding, it can be separated from the friction stir welding tool body and can be integrated with the member to be joined. Various forms of friction stir welding that cannot be achieved can be realized. For example, friction stir welding inside a hole in a tubular part, where it is difficult to place the welding tool with a conventional welding tool, can be easily realized. That is, the joining auxiliary material is arranged inside the hole as corresponding to the shape of the hole of the tubular part, the friction stir welding tool main body is fitted to the joining auxiliary material, and the joining auxiliary material is driven to rotate. The auxiliary material and the inside of the tubular part are in sliding contact, and the inside of the tubular part can be frictionally stirred. As described above, in the present invention, the form, arrangement, material, and the like of the joining auxiliary material can be appropriately determined or selected in response to downsizing / thinning of the members to be joined, diversification of joining parts, and the like. Thus, various forms of friction stir welding can be realized. In particular, the smaller the size, the smaller the space, the thinner the plate, and the finer the structure, the greater the influence of the size and shape of the friction stir welding tool, the load during welding, etc. Is a great advantage.

  However, the present inventors have found that in these friction stir welding, there is a problem that is not a problem in the conventional friction stir welding. In other words, due to the downsizing and thinning of the members to be joined, further diversification of shapes and joining parts, restrictions on the shape after joining, restrictions on space and environment, etc., the generation of the friction stir layer becomes insufficient, and It has been found that problems such as insufficient bonding force or breakage of a member to be bonded can occur. In addition, the present inventors have introduced a joining auxiliary material at the time of the friction stir welding process, which is caused when the friction stir welding is performed and causes a deterioration in the appearance of a member to be joined which is reduced in size and thickness. It has been found that the appearance after bonding can be improved by effectively utilizing.

  Then, the present inventors use the deformation or wear of the joining auxiliary material during the friction stir welding process to change the pressure receiving direction of the members to be joined, the pressure receiving distribution (local pressure), etc. It has been found that the appearance after bonding can be improved.

  For example, when the member to be joined is friction stir welded from the inside of the hole, the outer diameter of the member to be joined is set to be equal to that of the member to be joined in order to ensure the pressure applied to the sliding surface between the member to be joined and the joining aid. If it is larger than the inner diameter of the hole, the torque required at the start of rotational drive by the friction stir welding tool body becomes too large, making it difficult to increase the outer diameter of the welding aid. It can be difficult to get.

  Therefore, in the present invention, the pressure applied to the welding tool (for example, the force in the downward direction of the welding tool) is different via the welding auxiliary material that is a constituent member of the welding tool, that is, using the deformation of the welding auxiliary material. It is converted into force vector, and the pressure receiving direction of the member to be joined by the joining tool is changed to secure the pressure acting on the sliding surface between the member to be joined and the joining auxiliary material, and the member to be joined is rubbed by the joining auxiliary material. Stir and join. As described above, since the pressure of the joining auxiliary material on the sliding surface between the joining auxiliary material and the member to be joined is generated or adjusted by using the deformation of the joining auxiliary material, Friction stir welding can be performed and the bondability can be improved (see Examples 1 to 6 for further details).

  In addition, for example, when spot-stirring friction stir welding of laminated plate materials, a conventional welding tool locally applies pressure to the members to be joined, causing local deformation of the members to be joined and causing friction. The appearance after stir welding may deteriorate.

  Therefore, in the present invention, for example, the welding auxiliary material is formed into a large disk shape as compared with the friction stir welding tool body, and the pressure of the welding tool (the force in the downward direction of the welding tool) is used as a disk that is a constituent member of the welding tool. The pressure receiving direction and the pressure distribution of the members to be joined by the joining tool are changed by converting the force vector into a different force vector through the use of the joining aid material in a shape, that is, using the deformation of the disk-like joining aid material. In this way, by using the deformation of the disk-shaped joining auxiliary material, by generating or adjusting the pressing force on the sliding surface between the joined member and the joining auxiliary material, the pressurized force is locally applied to the joined member. Since it does not act, friction stir welding can be performed while suppressing local deformation of the members to be joined, and the appearance after joining can be improved (see Examples 7 to 9 for further details).

  In addition, as above-mentioned, in this invention, the joining auxiliary | assistant material is used as the joining tool structural member used up by one friction stir welding. Here, the term “joining auxiliary material” means that the constituent members of the friction stir welding tool are different from the so-called single-use tool, and are deformed during the friction stirring step as described above, so that the joining property of the members to be joined is reduced. This is because it can be regarded as a joint improving component supplied for each friction stir welding.

  The present embodiment (embodiment 1) will be described with reference to FIGS. 1A to 1D. FIG. 1A is a cross-sectional view at the time of completion of friction agitation in the present embodiment, and FIGS. 1B to 1D are enlarged cross-sectional views for explaining the behavior of the joint portion in the joining step in the present embodiment. In addition, although deformation | transformation is largely described so that it may be easy to understand in drawing, in reality, the deformation | transformation of a joining auxiliary material is slight.

  The present embodiment is applied to the case where the members to be joined 3 of the thick laminated plates (two sheets) are subjected to friction stir welding from the inside of the hole. In addition, a present Example is applicable also when carrying out the friction stir welding of the two pipe-shaped to-be-joined members 3 from an inner wall surface side.

  In this embodiment, the disk-shaped joining auxiliary material 1 is fitted and sandwiched in advance in a space formed between two members to be joined 3, and the joining auxiliary material is rotated by the friction stir welding tool body 2, thereby joining assistance. The material 1 and the member 3 to be joined are rotated and slid. In this embodiment, the joining surface of the member to be joined 3 is friction stir welded with the joining auxiliary material, and the joining aid material itself is friction stir welded to the joined member on the three surfaces of the outer peripheral side surface, the upper surface, and the lower surface. Can be realized. As described above, by using the joining auxiliary material, friction stir welding in a form that cannot be conceived from the prior art becomes possible. In the case of friction stir welding in such a form, the pressure applied on the sliding surface is two. It depends on the degree of fitting when the auxiliary bonding material is fitted and sandwiched in the space formed between the two members 3 to be joined. However, there is a possibility that sufficient pressure cannot be obtained on the sliding surface simply by fitting. In addition, when it is fitted with excessive force, the applied pressure becomes too large and a large rotational force is required to resist the applied pressure, and it may be difficult to apply such rotational force. There is. In particular, the problem of the rotational force is important because the three surfaces of the joining auxiliary material are in contact with the member to be joined.

  Therefore, in this embodiment, in order to cope with the lack of joining force due to lack of pressure on the sliding surface, or the difficulty of transmitting rotational force against the pressure, the joining aid 1 is During the joining process, the friction stir welding is performed while being distorted by the applied pressure of the friction stir welding tool body 2 (FIG. 1A). By doing in this way, since a joining auxiliary material will incline in a fitting part with a to-be-joined member, a pressurizing force generate | occur | produces partially in each contact surface (a side surface, an upper surface, and a lower surface). That is, the pressure of the welding tool (the force in the downward direction of the welding tool) is changed to a different force vector via the welding auxiliary material 1 that is a constituent member of the welding tool, that is, using the deformation of the welding auxiliary material 1. The pressure applied to the sliding surfaces of the member to be joined 3 and the joining auxiliary material 1 is ensured by conversion. Therefore, since the joining auxiliary member rotates and slides while generating a pressing force against the member to be joined, it is possible to effectively perform the friction stir welding and realize a strong joining.

  In this embodiment, the joining auxiliary material 1 has a disk shape with a hole. As shown in FIG. 1B, the disk-like joining auxiliary material 1 is fitted and sandwiched in a space formed in advance between two members 3 to be joined. After that, the friction stir welding tool main body 2 is lowered and fitted into the hole of the joining auxiliary material. In order to reliably transmit the rotational force, irregularities may be formed on the contact surface between the inner surface of the welding auxiliary material 1 and the outer surface of the friction stir welding tool body 2. In addition, the joining auxiliary material 1 does not necessarily need to have a hole. A simple disk-shaped member may be used, and a fitting portion (concave or convex) with the friction stir welding tool main body may be formed at the center thereof. After the connection of the friction stir welding tool main body 2 with the welding auxiliary material 1 is completed, the friction stir welding tool main body 2 is rotated. Thereby, the joining auxiliary material 1 and the member to be joined 3 rotate and slide. In addition, since a large force is required at the initial stage of rotation, it is better to generate the applied pressure by the deformation after the rotation. After the friction stir welding tool body 2 reaches a predetermined number of revolutions, the friction stir welding tool body 2 is further lowered as shown in FIG. 1C. Thereby, as shown to FIG. 1C, the joining auxiliary | assistant material 1 receives the downward force on the inner side rather than the outer periphery, and the deflection | deviation of the direction where the center sinks generate | occur | produces. In addition, since frictional heat is generated by rotational sliding, the joining auxiliary material 1 is easily deformed. As a result, the joining auxiliary material is deformed, and if attention is paid to the side surface, a pressing force in the horizontal direction is generated. Thereby, the side surface of the joining auxiliary material 1 and the inner peripheral wall of the member 3 to be joined are rotated and slid while partially generating a high pressure. Moreover, a local pressurizing part is also generated on the upper and lower surfaces of the bonding auxiliary material 1. As a result, the upper and lower surfaces of the joining auxiliary member and the member to be joined are rotated and slid while partially generating a high applied pressure. As a result, as shown in FIG. 1D, the friction stirrer layer 4 is formed on the joining surface of the member to be joined 3 while partially generating high pressurizing force on the joining aid material 1, and the joining aid material itself is on the outer peripheral side surface. Then, the friction stir layer 4 is formed while generating a high pressurizing force partially with respect to the member to be joined on the three surfaces of the upper surface and the lower surface. That is, the friction stir layer 4 is formed without causing insufficient pressurization, and strong bonding can be realized. The joint surfaces formed in this way are the upper, lower, and outer peripheral surfaces of the disk-shaped joining auxiliary material, and even if a local stress occurs in a slight gap, it is difficult to break, and also for joining other surfaces. Since there is no influence, the bonding reliability is very high. Further, in this embodiment, since the joining auxiliary material can be deformed to adjust the pressure, it is necessary to fit the joining aid to the member to be joined with an excessive force in order to obtain the pressure. There is no need for a large rotational force that is substantially difficult to prepare.

In addition, an example of the friction stir welding apparatus used when implementing the friction stir welding method of a present Example and the below-mentioned Example is shown in FIG. FIG. 11 is a diagram illustrating a schematic configuration of the friction stir welding apparatus.
The friction stir welding apparatus includes a welding tool (friction stir welding tool main body) rotating motor 10, a welding tool (friction stir welding tool main body) pressing motor (or air cylinder) 20, and a welding tool (friction stir welding tool main body) supporting. The arm 30, the fixing jig 40 for fixing the member to be joined, the work table 50 for moving the fixing jig in the xy direction, and a joining tool (friction stir welding tool main body) holding unit 60 are roughly configured. A control device (not shown) for driving and controlling these devices is provided. Moreover, in FIG. 11, illustration of the joining auxiliary material is omitted. The joining auxiliary material is previously attached to the member 3 to be joined or is fitted to the tip of the friction stir welding tool main body 2.

  In the above-described embodiment, the friction stir welding tool main body is lowered in order to deform the joining auxiliary material. However, in order to obtain the deformation of the joining auxiliary material, the rotation shaft between the member to be joined and the joining auxiliary material is used. Since there is only a relative displacement in the direction, the member 3 to be joined may be raised.

  In this embodiment, the friction stir welding tool main body 2 and the joining auxiliary material 1 are rotated. However, the friction stir welding tool main body 2 and the welding auxiliary material 1 are fixed, and the member 3 to be joined is rotated. Also good. When the member to be joined 3 and the joining auxiliary material 1 are brought into sliding contact, the friction stir welding tool main body 2 is held so as not to rotate. The rotation of the material 1 is prevented.

  In the present embodiment, the case where the friction stir welding is performed from the inside of the hole formed in the member to be joined has been described. However, for example, when the member to be joined is a tubular member, the present invention can also be applied to the case where the friction stir welding is performed from the outside. . In this case, the inner diameter of the joining auxiliary material is equal to or larger than the outer diameter of the tubular member, and if the pressure of the friction stir welding tool body is applied to the outer peripheral portion of the joining auxiliary material, the joining auxiliary material and the object to be joined are deformed by the deformation of the joining auxiliary material. A pressing force can be secured on the sliding surface of the member.

  A second embodiment will be described with reference to FIGS. 2A to 2B. In the present embodiment, in addition to the configuration of the first embodiment, as shown in FIG. 2A, the outer diameter of the inserted portion of the bonded member 3 of the friction stir welding tool body 2 is slightly smaller than the inner diameter of the hole of the bonded member. An annular cutter 2A is provided. The cutter 2 </ b> A is configured to perform a lowering operation independently of the lowering operation of the friction stir welding tool body 2. After the friction stir welding of the member 3 to be joined, as shown in FIG. 2B, the cutter 2 </ b> A is pressed down to cut and remove the disk portion 1 </ b> G of the joining auxiliary material 1 remaining inside the hole of the member 3 to be joined. The outer diameter portion 1F of the auxiliary bonding material 1 remains integrated in the member 3 to be bonded. Thus, by cutting and removing the disc portion 1G of the joining auxiliary material 1, it is possible to form the hole of the member 3 to be joined into a relatively smooth circular pipe in the same process as the friction stir welding.

  A third embodiment will be described with reference to FIGS. 3A to 3C. FIG. 3A is a diagram illustrating an example of a bonding auxiliary material used in the present embodiment, and FIGS. 3B to 3C are process explanatory diagrams of the bonding method according to the third embodiment. This embodiment is also applied to the case where the members to be joined 3 of thick laminated plates (two sheets) are subjected to friction stir welding from the inside of the hole. The present embodiment can also be applied to the case where two pipe-like members 3 are friction stir welded from the inner wall surface side.

  When the inner wall surface is friction stir welded from the inside of a hole, such as by joining thick plates or pipes, the inner wall surface direction (friction stir welding tool body (joint aid It is desirable to apply pressure in the vertical direction).

  In this embodiment, the joining aid is provided with a shape means (structural means) for deforming in the outer circumferential direction in accordance with the descending pressure of the friction stir welding tool body. Deformation in the direction (perpendicular to the rotation axis) occurs, and it is possible to generate sufficient pressure on the inner wall of the member to be joined and the outer peripheral surface of the joining auxiliary material. That is, also in the present embodiment, the force in the descending direction of the joining tool is converted into different force vectors via the joining auxiliary material 1 which is a constituent member of the joining tool, and the joined member 3 and the joining auxiliary material 1 The pressure applied to the sliding surface is secured.

  As shown in FIG. 3A, the joining auxiliary material 1 has a slotted cylindrical portion 1A provided with a long (high) slit (a plurality of slits open on one side) 1B, and a slotted cylindrical shape. The inner wall of the portion 1A is a tapered surface with a small diameter at the tip. Similarly to the inner wall, the outer wall of the cylindrical portion 1A with a slit has a tapered surface with a small diameter, and the cylindrical portion 1A with a slit has a tapered tube (the thickness of the slit portion is constant, and the outer wall has the same angle as the inner wall. It is formed as a taper). 3A (a) is a schematic cross-sectional view of the joining aid, and FIG. 3A (b) is a view of the joining aid from below. Further, as shown in FIG. 3B, the joining auxiliary material 1 is the same as FIG. 3A in that the inner wall of the slotted cylindrical portion 1A has a tapered surface, but the outer wall of the slotted cylindrical portion 1A. Can be formed as a straight pipe (change in the thickness of the slit portion).

Based on FIG. 3B and FIG. 3C, the joining method in a present Example is demonstrated by taking the case where the latter joining auxiliary material (slot part thickness change) is used as an example.
As shown in FIG. 3B, the joining auxiliary material 1 is composed of a cylindrical portion 1A with a slit of an outer straight pipe and an inner tapered pipe, and a perforated disk portion 1C formed on the upper portion. The hole formed in advance in the member 3 to be joined has a hole diameter that is the same as or slightly larger than the outer diameter of the joining auxiliary material 1 (cylindrical portion 1A with slit). Further, the slotted cylindrical portion 1A of the joining auxiliary material 1 is installed in advance in the hole of the member 3 to be joined, and is supported on the upper surface of the member 3 to be joined by the heel 1H of the perforated disk portion 1C. The It is preferable that the tip of the slotted cylindrical portion 1 </ b> A of the joining auxiliary material 1 is in the vicinity of slightly exceeding the joining surface of the member 3 to be joined.

  As shown in FIG. 3B, the friction stir welding tool main body 2 is lowered and the protrusion 2 </ b> B of the friction stir welding tool main body 2 is fitted into the groove 1 </ b> K formed in the holed disk portion 1 </ b> C of the welding auxiliary material 1. Thereby, the rotational motion of the friction stir welding tool main body 2 is transmitted to the joining auxiliary material 1, the joining auxiliary material 1 rotates, and the outer periphery of the joining auxiliary material 1 (the cylindrical portion 1 </ b> A with the slit) and the joined member 3. The inner wall slides and friction stirring starts. The friction stir welding tool main body 2 is advanced into the tapered tube of the slotted cylindrical portion 1A of the welding auxiliary material 1 by the pressurizing force of the friction stir welding tool main body 2 as the temperature of the welding auxiliary material 1 increases. . The slotted cylindrical portion 1A of the joining auxiliary material is frictionally stirred with the inner wall of the member 3 to be joined while being pressed by the friction stir welding tool main body 2 to open in the outer circumferential direction (FIG. 3C). That is, the member to be joined 3 is friction stir welded while the inner wall of the member 3 to be joined receives the pressure applied to the outer periphery of the joining auxiliary material 1.

  In this embodiment, the friction stir welding tool main body 2 is lowered, but the joining auxiliary material 1 is not lowered because it is supported on the upper surface of the member 3 to be joined by the ridges of the perforated disk portion 1H. In consideration of this, a fitting shape of the friction stir welding tool main body 2 and the joining auxiliary material 1 (perforated disk portion 1C) is desired. Here, in order to transmit the rotational motion, a protrusion is formed on the outer wall of the friction stir welding tool main body 2 2B is provided with a groove 1K on the inner wall of the perforated disk portion 1C of the joining auxiliary material, and the depth of the groove 1K (depth in the rotation axis direction) is a depth at which the protrusion 2B of the friction stir welding tool body 2 can descend. It is said.

  In addition, when using the joining auxiliary | assistant material 1 which has the cylindrical part 1A with the slit of a taper pipe | tube as shown in FIG. 3A, the junction inner wall of the hole of the to-be-joined member 3 is the grinding | polishing of the joining auxiliary | assistant material 1. A tapered inner wall (reduced tube) similar to the outer wall of the split cylindrical portion 1A is used. Further, the outer shape of the friction stir welding tool main body 2 is a tapered outer shape combined with the inner wall of the cylindrical portion 1 </ b> A with the slit portion of the bonding auxiliary material 1. In the joining step, the joining auxiliary material 1 is placed on the tapered portion of the hole of the member 3 to be joined, and then the friction stir welding tool body 2 is inserted. A fitting shape (such as a wrench or a driver shape) capable of transmitting the rotational force and the applied pressure of the friction stir welding tool main body 2 is appropriately formed in the welding auxiliary material 1. However, the applied pressure is applied not to the head portion of the joining auxiliary material 1 but to the inner wall tapered portion of the slotted cylindrical portion 1A. By rotating and pressurizing the friction stir welding tool body 2, the bonding auxiliary material 1 rotates and slides with the member 3 to be bonded. The pressurizing force of the friction stir welding tool body 2 is applied to the inner wall taper surface of the slotted cylindrical portion 1A of the welding auxiliary material 1, so that the outer peripheral taper surface of the friction stir welding tool body 2 descends along the taper surface. . Since the joining auxiliary material 1 is fixed so as not to be lowered by the inner wall tapered surface of the member 3 to be joined, the force by which the friction stir welding tool body 2 descends pushes the slotted cylindrical portion 1A of the joining auxiliary material 1. It becomes power. That is, the applied pressure acts in the outer peripheral direction of the joining auxiliary material 1, and this applied pressure becomes the energy of friction stir welding together with the rotational sliding on the inner wall of the member 3 to be joined and the outer circumference of the joining auxiliary material 1. It is possible to improve the bondability.

  As in the first embodiment, in this embodiment, in order to deform the joining auxiliary material 1, the member to be joined 3 may be raised, and the joining auxiliary material and the member to be joined are rotated and slid. In order to make contact, the friction stir welding tool main body 2 and the joining auxiliary material 1 may be fixed, and the member to be joined 3 may be rotated.

  A fourth embodiment will be described with reference to FIGS. 4A to 4B. 4A to 4B are process explanatory views of the joining method in the fourth embodiment. This embodiment is also applied to the case where the members to be joined 3 of thick laminated plates (two sheets) are subjected to friction stir welding from the inside of the hole. The present embodiment can also be applied to the case where two pipe-like members 3 are friction stir welded from the inner wall surface side.

  In the present embodiment, similar to the third embodiment, the friction stir welding is performed by providing a shape auxiliary means (structural means) for deforming in the outer peripheral direction in accordance with the descending pressure of the friction stir welding tool body on the joining auxiliary material. Sometimes, the auxiliary joining material is deformed in the direction of the outer periphery (perpendicular to the rotation axis), so that sufficient pressure can be generated on the inner wall of the joined member and the outer peripheral surface of the joining auxiliary material. It is.

  As shown in FIG. 4A, the joining auxiliary member 1 of the present embodiment is basically configured in a circular tube shape, and has a barrel shape in which an intermediate portion swells in an arc shape in the outer peripheral direction as compared with the upper end and the lower end. ing. A step portion 3 </ b> A is formed in the hole of the member 3 to be joined. The step portion 3A is formed on the inner wall below the joint portion. The lower end (lower surface) of the joining auxiliary material 1 is supported by the stepped portion 3 </ b> A of the joined member 3. And the intermediate part of the joining auxiliary member 1 is located in the joint part vicinity of a to-be-joined member. The friction stir welding tool main body 2 has a shape capable of transmitting the rotational motion and the pressure applied to the upper surface of the welding auxiliary material 1 to the welding auxiliary material 1. The friction stir welding tool main body 2 descends and fits with the welding auxiliary material 1, and the rotational motion of the friction stir welding tool main body 2 is transmitted to the welding auxiliary material 1. Sliding with the inner wall, frictional stirring of the bonded member 3 is started (FIG. 4A). Although a downward pressing force is applied to the friction stir welding tool body 2, the welding auxiliary material 1 cannot be lowered because the lower surface is suppressed by the stepped portion 3 </ b> A of the member to be joined. As the temperature of the welding aid 1 increases, the welding aid 1 is compressed and deformed by the pressure applied by the friction stir welding tool body 2. This deformation becomes a force that opens the intermediate portion of the joining auxiliary material 1 in the outer peripheral direction, and also becomes a pressure applied to the inner wall of the member to be joined. The member to be joined is effectively frictionally stirred by this applied pressure and rotational sliding (FIG. 4B). That is, the friction stir welding is performed while the inner wall of the member to be joined receives the pressure in the outer peripheral direction of the joining auxiliary material 1.

  In addition, even if the joining auxiliary material 1 does not have a barrel shape as shown in FIG. 4A, it is possible to obtain a pressure application in the direction of the inner wall surface by the same operation as in this embodiment. For example, the joining auxiliary material 1 is basically formed in a circular pipe (straight pipe) shape with respect to the inner and outer shapes, and is formed so that the intermediate portion in the height direction is thinner than the upper end and the lower end. For example, a step or a taper is partially formed in the intermediate part of the inner wall of the joining auxiliary material to form a thin part. In addition, it is preferable that the intermediate part of the outer wall of the joining auxiliary material has a shape that slightly swells in the outer peripheral direction. In the joining step, the friction stir welding tool main body 2 is fitted to the joining auxiliary material 1, and the joining auxiliary material 1 is rotated and pressurized. At this time, since the joining auxiliary material 1 is pressed by the step of the hole of the member 3 to be joined, the applied pressure becomes a force for compressing the joining auxiliary material 1. Since the joining auxiliary material 1 has a thin intermediate portion as described above and has a shape that easily deforms outward, the intermediate portion tends to further expand in the outer peripheral direction when compressed. . That is, the pressure is applied in the outer circumferential direction of the joining auxiliary material 1, and this pressure becomes the energy of friction stir welding together with the rotational sliding on the inner wall of the member 3 to be joined and the outer circumference of the joining auxiliary material 1, and friction stir welding. It is possible to improve the bondability.

  As in the first embodiment, in this embodiment, in order to deform the joining auxiliary material 1, the member to be joined 3 may be raised, and the joining auxiliary material and the member to be joined are rotated and slid. In order to make contact, the friction stir welding tool main body 2 and the joining auxiliary material 1 may be fixed, and the member to be joined 3 may be rotated.

  Example 5 will be described with reference to FIGS. 5A to 5B. 5A to 5B are process explanatory views of the joining method in the fifth embodiment. This embodiment is applied to the case where two pipe-like members 3 are friction stir welded from the inner wall surface side. The present embodiment can also be applied to the case where the members to be joined 3 of the thick laminated plates (two sheets) are friction stir welded from the inside of the hole.

  In the fourth embodiment, the stepped portion 3 </ b> A formed in the hole of the member 3 to be joined can be a hindrance to rotation of the joining auxiliary material 1 due to the contact area between the stepped portion and the lower surface of the joining auxiliary material 1. That is, the larger the area, the better to receive the applied pressure in the descending direction of the friction stir welding tool body 2, but it is necessary to rotate the welding auxiliary material at high speed while sliding with the surface (step) on which the applied pressure works. In addition, the area expansion becomes a factor that causes insufficient rotational force.

  As a countermeasure, in this embodiment, no step is formed in the hole of the member 1 to be joined, and the joining auxiliary material 1 is inserted into the hole of the member 1 to be joined from the side opposite to the friction stir welding tool body 2. Installed on the pedestal 6. This pedestal 6 is rotatable and is separately supported so as not to descend. In other words, in the present embodiment, the lower end of the welding auxiliary material 1 (the surface opposite to the pressure surface by the friction stir welding tool body 2) is in contact with the pressure receiving surface that can rotate during the bonding process. Accordingly, the pedestal 6 also rotates in accordance with the rotation of the joining auxiliary material 1, receives the pressure applied in the descending direction without obstructing the rotation, and acts on the deformation energy of the joining auxiliary material 1 (the inner wall of the member to be joined). (Pressure) can be generated.

  As shown in FIG. 5A, in this embodiment, the joining auxiliary material 1 is constituted by a tapered pipe with a slit, and the vicinity of the joining surface of the member 3 to be joined is also a tapered pipe. And the joining auxiliary | assistant material 1 is mounted on the base 6 which is a jig | tool which the rotation and the position of the height direction were fixed. Then, as shown in FIG. 5B, by lowering the friction stir welding tool main body 2, a pressing force in the outer peripheral direction is generated in the cylindrical portion 1A with the slit portion. Friction stir welding is effectively performed by the pressure applied to the joining aid and the rotation of the joining aid. Further, in this embodiment, the lowering of the joining auxiliary material 1 is restrained by a rotatable pedestal instead of the collar part (the collar part), so that the sliding between the collar part and the upper surface of the member 3 to be joined is suppressed. There is no rotation inhibition.

  As in the first embodiment, in this embodiment, in order to deform the joining auxiliary material 1, the member to be joined 3 may be raised, and the joining auxiliary material and the member to be joined are rotated and slid. In order to make contact, the friction stir welding tool main body 2 and the joining auxiliary material 1 may be fixed, and the member to be joined 3 may be rotated. In this case, the pedestal 6 is also fixed.

  Example 6 will be described with reference to FIGS. 6A to 6B. 6A to 6B are process explanatory views of the joining method in the sixth embodiment. This embodiment is also applied to the case where the members to be joined 3 of thick laminated plates (two sheets) are subjected to friction stir welding from the inside of the hole. The present embodiment can also be applied to the case where two pipe-like members 3 are friction stir welded from the inner wall surface side.

  In this embodiment, as shown in FIG. 6A, the lower end of the joining auxiliary material 1 is in contact with a rotatable base 6 (a rotatable pressure receiving surface) during the joining process, as in the fifth embodiment. The pedestal 6 is separately supported so as not to descend (so that the height can be maintained). As the joining auxiliary material 1 in the present embodiment, the same barrel shape as in the fourth embodiment is used. Unlike the fourth embodiment, the inner wall of the hole formed in the member to be joined 3 is not formed with a step and is formed in a circular tube shape. Therefore, the joining auxiliary material 1 is inserted into the hole from the upper surface of the member 1 to be joined, and the lower end thereof is placed on the rotatable pedestal 6 having a fixed height.

  As shown in FIG. 6B, when the friction stir welding tool body 2 is lowered while being rotated, the joining auxiliary material 1 is supported by the pedestal 6 so as not to be lowered. The middle part of the member 3 swells in the outer circumferential direction, and the member to be joined 3 is subjected to friction stir welding while exerting a pressure in the outer circumferential direction on the inner wall of the hole of the member 3 to be joined. In the present embodiment, the lowering of the joining auxiliary material 1 is suppressed by a rotatable pedestal instead of the stepped portion formed on the joined member. Therefore, even if a large pressure is applied to the joining auxiliary material 1 by the friction stir welding tool body 2 in order to cause deformation of the joining auxiliary material 1, the lower end of the joining auxiliary material 1 is not in sliding contact with the member to be joined. So it does not become rotation inhibition.

  As in the first embodiment, in this embodiment, in order to deform the joining auxiliary material 1, the member to be joined 3 may be raised, and the joining auxiliary material and the member to be joined are rotated and slid. In order to make contact, the friction stir welding tool main body 2 and the joining auxiliary material 1 may be fixed, and the member to be joined 3 may be rotated. In this case, the pedestal 6 is also fixed.

  A seventh embodiment will be described with reference to FIGS. 7A to 7B. 7A and 7B are process explanatory views of the joining method in Example 7. FIG. This embodiment is applied to a method of spot-stirring friction stir welding of laminated plate materials.

  The member 3 to be joined is a laminated plate material, and the disk-shaped joining auxiliary material 1 is placed thereon (FIG. 7A). The outer diameter of the disk-shaped joining auxiliary material 1 is larger than the outer diameter of the friction stir welding tool body 2 (the outer diameter of the pressurizing portion with respect to the joining auxiliary material 1). The friction stir welding tool main body 2 descends while rotating and contacts the welding auxiliary material 3.

  Here, the friction stir welding tool main body 2 to the welding auxiliary material 1 needs to be fitted so that rotation and pressure are transmitted. Although it is possible to form the fitting shape on the joining auxiliary material 1, a claw 2 </ b> C as shown in FIG. 8B is provided on the contact surface of the friction stir welding tool body 2 with the joining auxiliary material 1. When the rotation is transmitted, the joining auxiliary material 1 can have a simple disk shape. 8A is a side view of the front end portion of the friction stir welding tool main body 2, and FIG. 8B is a view of the front end portion of the friction stir welding tool main body 2 as viewed from below. If such a rotation transmission means is formed at the tip of the friction stir welding tool main body 2, the contact area between the friction stir welding tool main body 2 and the welding auxiliary material 1 becomes small. The heat conduction to the rotation / pressure source device via the welding tool body 2 and further the friction stir welding tool body 2 is reduced, the temperature of the friction stirrer is increased, and the bondability is improved.

  As shown in FIG. 7A, the joining auxiliary material 1 is pressurized while being given a rotational motion, and frictional stirring is started. At the beginning of frictional stirring, the joining auxiliary material 1 maintains a flat plate shape, and the member 3 to be joined and its bottom face are in full contact with each other and slide. At this time, the force vector that the friction stir welding tool body 2 applies to the disk-shaped joining auxiliary material 1 is substantially uniform and in the same direction over the entire contact surface with the member 3 to be joined. That is, depending on the hardness of the disk-shaped joining auxiliary material 1, the force vector applied to the member 3 by the disk-shaped joining auxiliary material 1 is only on the lower surface of the contact surface of the friction stir welding tool body with the joining auxiliary material. Not even the surroundings. However, since the friction stir welding tool main body 2 pressurizes the central portion of the joining auxiliary material 1, the joining auxiliary material 1 gradually deforms and sinks into the joined member 3 while the central portion is depressed (FIG. 7B). . That is, the friction stir welding tool body 2 is converted into a force vector that gradually decreases from the lower surface (center portion) of the friction stir welding tool body 2 to the surroundings. The vector is even smaller. In addition, the direction of the force vector also changes obliquely in the vicinity of the outer periphery of the friction stir welding tool body. That is, with the bending deformation of the joining auxiliary material 1, the to-be-joined member 3 undergoes softening and plastic flow while the sliding area, frictional heat generation state, and applied pressure of the joining auxiliary material 1 and the to-be-joined member 3 change. Joined (FIG. 7C). Thereafter, if the friction stir welding tool main body 2 is pulled up while being rotated, the joining auxiliary material 1 is detached from the member to be joined 3, and a laminated plate of only the member to be joined 3 is obtained as shown in FIG. 7D. Moreover, it is also possible to leave the joining auxiliary material 1 integrated with the member 3 to be joined by pulling up after stopping the rotation of the friction stir welding tool body 2. The integration of the joining auxiliary material 1 and the member to be joined 3 can also be set by the material of the joining auxiliary material and the member to be joined. It is also possible to control the joining state of the members.

  In this embodiment, first, frictional heat is generated in a wide range, and the central portion gradually becomes a high distributed load according to the deflection of the joining auxiliary material 1. Further, the bending deformation of the joining auxiliary material 1 brings about a contact surface with the member 3 to be joined which has a gentler curved surface than the shape of the friction stir welding tool body 2. Accordingly, the friction stirrer always has a softened part due to frictional heat around it, and there is no abrupt load (force vector) change point, thus reducing local thinning and surface floating deformation of the member 3 to be joined. Laminated spot friction stir welding is possible.

  As in the first embodiment, in this embodiment, in order to deform the joining auxiliary material 1, the member to be joined 3 may be raised, and the joining auxiliary material and the member to be joined are rotated and slid. In order to make contact, the friction stir welding tool main body 2 and the joining auxiliary material 1 may be fixed, and the member to be joined 3 may be rotated.

  An eighth embodiment, which is one variation of the seventh embodiment, will be described with reference to FIGS. 9A to 9D. A difference in configuration between the present embodiment and the seventh embodiment is that the shape of the joining auxiliary material 1 is not a simple disk shape but a dish shape (substantially truncated cone shape or hemispherical shape). As shown in FIG. 9A, the dish-shaped joining auxiliary material 1 is placed in a direction in which the dish-shaped joining auxiliary material 1 is turned down (so that there is a gap with the joined member plane in the central portion 1D). The friction stir welding tool main body 2 descends while rotating and comes into contact with the joining auxiliary material 3 to pressurize the member 3 to be joined while being given rotational motion to the joining auxiliary material 1. At the beginning of friction stirring, the joining auxiliary material 1 maintains a dish shape, and the bottom surface of the outer peripheral portion 1E of the member to be joined 3 and the joining auxiliary material 1 comes into contact with and slides. However, since the friction stir welding tool main body 2 pressurizes the central portion 1D of the joining auxiliary material 1, the central portion 1D of the joining auxiliary material 1 gradually becomes depressed, and contacts and slides on the member 3 to be joined (FIG. 9C). As the entire joining auxiliary material 1 is bent and deformed, a large load is applied to the central portion 1D as shown in FIG. That is, first, friction agitation is started from the outer peripheral portion 1E, and finally the central portion 1D is frictionally agitated, and the member 3 to be joined is softened and joined by causing plastic flow.

  In this embodiment, the laminated spot friction stir welding in which local thinning of the member to be joined 3 and surface lifting deformation are further reduced than in the seventh embodiment is possible.

  As in the first embodiment, in this embodiment, in order to deform the joining auxiliary material 1, the member to be joined 3 may be raised, and the joining auxiliary material and the member to be joined are rotated and slid. In order to make contact, the friction stir welding tool main body 2 and the joining auxiliary material 1 may be fixed, and the member to be joined 3 may be rotated. Further, in the present embodiment as well as in the seventh embodiment, it is possible to select whether the joining auxiliary material 1 is detached from the joined member 3 or integrated.

  A ninth embodiment, which is another variation of the seventh embodiment, will be described with reference to FIGS. 10A to 10D. As shown in FIG. 10A, the structural difference between the present example and the examples 7 and 8 is that the joining auxiliary material 1 is opened (the center part 1D is in contact with the plane of the member 3 to be joined, and the outer peripheral part 1E is placed so that there is a gap), the outer diameter of the welding auxiliary material 1 is substantially the same as the outer diameter of the friction stir welding tool main body 2, and the friction stir welding tool main body 2 is a bonding aid. That is, the outer peripheral portion 1E of the material 1 contacts and receives pressure.

  The friction stir welding tool main body 2 descends while rotating and comes into contact with the joining auxiliary material 3 to pressurize the member 3 to be joined while being given rotational motion to the joining auxiliary material 1. As shown in FIG. 10B, at the beginning of friction stirring, the joining auxiliary material 1 maintains a dish shape, and the to-be-joined member 3 and the bottom surface of the central portion 1D come into contact with each other and slide, and the central portion 1D is to be joined. Friction stirring is performed while biting into the member 3. However, since the friction stir welding tool main body 2 pressurizes the outer peripheral portion 1E of the auxiliary joining material 1, as shown in FIG. 10C, the outer peripheral portion 1E of the auxiliary joining material 1 gradually collapses and contacts / slids against the member 3 to be joined. To do. Then, as shown in FIG. 10D, when a large load is applied to the outer peripheral portion 1E of the auxiliary joining material 1, the members to be joined are softened and plastically flowed and joined. Since the friction stir welding tool main body 2 is in contact with the outer peripheral portion 1E of the welding auxiliary material 1 and the central portion 1D is escaping, a high load is applied to the outer peripheral portion 1E, and the friction stirring portion of the joined member 3 corresponds to the central portion 1D. It also plastically flows to the place where it does. That is, first, friction agitation is started from a location in contact with the central portion 1D, and finally, a location in contact with the outer peripheral portion 1E is subjected to friction agitation, so that the member 3 to be joined is softened and joined with plastic flow. Therefore, a relatively flat joint surface can be obtained.

  As in the first embodiment, in this embodiment, in order to deform the joining auxiliary material 1, the member to be joined 3 may be raised, and the joining auxiliary material and the member to be joined are rotated and slid. In order to make contact, the friction stir welding tool main body 2 and the joining auxiliary material 1 may be fixed, and the member to be joined 3 may be rotated. Further, in the present embodiment as well as in the seventh embodiment, it is possible to select whether the joining auxiliary material 1 is detached from the joined member 3 or integrated.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Joining auxiliary material, 1A ... Cylindrical part with a slot part, 1B ... Slot, 1C ... Perforated disk part, 1D ... Center part, 1E ... Outer periphery part, 1F: outer diameter portion of joining auxiliary material remaining on the member to be joined, 1G: disc portion of joining auxiliary material to be cut, 1H ... 庇 (鍔), 1K ... groove, 2 ... Friction stir welding tool body, 2A ... cutter, 2B ... projection, 2C ... claw, 3 ... member to be joined, 3A ... stepped portion, 4 ... friction stir layer, 6 ....・ Rotating base, 10 ... Motor for rotating the welding tool, 20 ... Motor for pressing the welding tool (or air cylinder), 30 ... Arm for supporting the welding tool, 40 ... Fixing jig, 50 ... -Work table, 60 ... Joining tool holding part.

Claims (16)

A joining auxiliary material that slidingly contacts the member to be joined and friction stirs the member to be joined, and is rotationally driven and is detachably connected to the joining auxiliary material. A method of friction stir welding the members to be joined using a friction stir welding tool provided with a friction stir welding tool body connected to an auxiliary material and rotating together with the joining auxiliary material,
During the friction stir welding step, the pressure of the joining aid on the sliding surface of the joining aid and the member to be joined is generated or adjusted using deformation of the joining aid,
After completion of the friction stir welding process, the welding auxiliary material is separated from the friction stir welding tool body. In the friction stir welding method according to claim 1,
Instead of rotationally driving the friction stir welding tool body, rotationally driving the member to be joined,
When the member to be joined is rotated to bring the member to be joined and the joining auxiliary material into sliding contact, the friction stir welding tool main body is held so as not to rotate, and during the friction stir welding process, the joining is performed. A friction stir welding method characterized in that it is connected to an auxiliary material to prevent rotation of the auxiliary bonding material. In the friction stir welding method according to claim 1 or 2,
The friction stir welding method is characterized in that the deformation of the joining auxiliary material is caused by causing a relative displacement between the friction stir welding tool and the member to be joined by lowering the friction stir welding tool. . In the friction stir welding method according to any one of claims 1 to 3,
A friction stir welding method, comprising: attaching the joining auxiliary material to the member to be joined in advance; and rotating the friction stir welding tool main body connected to the joining auxiliary material. In the friction stir welding method according to any one of claims 4,
A hole is formed in the member to be joined, and the joining auxiliary material is attached inside the hole so as to be sandwiched by the member to be joined,
The joining auxiliary material has a disk shape or a disk shape with a hole, and the vicinity of the center is pressed by the friction stir welding tool body, and the member to be joined is deformed in the direction in which the vicinity of the center is depressed. Friction stir welding method characterized by sliding contact with. In the friction stir welding method according to any one of claims 1 to 4,
A hole is formed in the member to be joined, and the inside of the hole and the joining auxiliary material are in sliding contact,
The method of friction stir welding, wherein the joining auxiliary material has a structural means that causes deformation in the outer peripheral direction of the joining auxiliary material during the friction stir welding step. In the friction stir welding method according to claim 6,
The joining auxiliary material has an annular portion having a slit, and an inner wall of the annular portion in which the slit is formed has a tapered surface, and the joining is performed by inserting the friction stir welding tool body into the annular portion. A friction stir welding method, wherein the auxiliary material is configured to be deformed in the outer circumferential direction. In the friction stir welding method according to claim 6,
The friction stir welding method according to claim 1, wherein the joining auxiliary member has a shape in which a substantially central portion of the joining aid material swells in an outer peripheral direction when the friction stir welding tool body is pressed and crushed up and down. In the friction stir welding method according to any one of claims 1 to 8,
A friction stir welding method, wherein a lower end of the joining auxiliary material is in contact with a pressure-receiving surface that is rotatable during the friction stir welding step. In the friction stir welding method according to any one of claims 1 to 4,
The friction stir welding method, wherein the joining auxiliary material is a disk-shaped joining auxiliary material, and has an outer diameter larger than an outer diameter of a pressurizing portion of the friction stir welding tool body with respect to the joining auxiliary material. In the friction stir welding method according to any one of claims 1 to 4,
The friction stir welding method according to claim 1, wherein the joining auxiliary material is dish-shaped, and the members to be joined are frictionally stirred while causing deformation to approach a flat disk shape by pressure received by the friction stir welding tool body. In the friction stir welding method according to claim 11,
A friction stir welding method, wherein the dish-shaped joining auxiliary material is arranged so that a convex surface side thereof faces the friction stir welding tool main body side and a concave surface side faces the member to be joined. In the friction stir welding method according to claim 11,
A friction stir welding method, wherein the dish-shaped joining auxiliary material is disposed such that a concave surface side thereof faces the friction stir welding tool main body side and a convex surface side faces the member to be joined. In the friction stir welding method according to any one of claims 1 to 4 and 6 to 13,
The friction stir welding method, wherein the joining auxiliary material is detached from the member to be joined after completion of the friction stir welding step. In the friction stir welding method according to any one of claims 1 to 13,
After the friction stir welding process is completed, the joining auxiliary material is integrated with the member to be joined, or is partially removed, and the remaining part is left integrally with the member to be joined. Stir welding method. A friction stir welding apparatus for performing the friction stir welding method according to any one of claims 1 to 4,
Friction stir welding tool comprising the welding aid and the friction stir welding tool body, means for rotationally driving the friction stir welding tool body, and adjusting the pressing force of the friction stir welding tool body to adjust the joining aid A friction stir welding apparatus, comprising: a pressing means for deforming the head.

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