JP6059649B2 - Double-side friction stir welding method and double-side friction stir welding apparatus - Google Patents

Description

  The present invention relates to a double-sided friction stir welding apparatus and a double-sided friction stir welding apparatus, in which a metal plate such as an aluminum member is abutted, and stir welding (FSW) is performed by frictional heat along the mating surface, and particularly a double-sided friction stir welding tool is used. In addition, the present invention also relates to a double-sided friction stir welding method for performing high-quality and efficient joining, and a double-sided friction stir welding apparatus for carrying out the same for a long aluminum member or the like.

In the following Patent Documents 1 and 2, double-sided friction stir welding is performed at a speed higher than the conventional joining speed along the abutting portion of two aluminum members abutted against each other by using the friction stir welding tools facing each other. A joining apparatus is disclosed.
One of such friction stir welding tools includes a large-diameter shoulder portion and a small-diameter probe on the end surface on the side that is coaxial with the shoulder portion and is inserted into the mating surface of the aluminum member. The other friction stir welding tool disposed so as to face each other with the butted portion of the aluminum member interposed therebetween has a recess having a diameter substantially larger than that of the probe of the one friction stir welding tool.

These two friction stir welding tools are inserted into the abutting portion of the aluminum member while being rotated in a state of being sandwiched from the front surface and the back surface, and stir welding is performed by giving heat to the abutting portion due to friction.
In this way, in the stir welding using the friction stir welding tool, by inserting a tool that rotates from both sides, a large amount of heat can be input compared to the conventional friction stir welding, and the joining speed can be increased. It has become.

  In Patent Document 3, only the peripheral part of the joining tool for temporary joining is pressed against the butt part of the joining member made of two aluminum materials arranged in the butt state, and the contact part with the peripheral part is softened by frictional heat. It is described that the joining member is temporarily joined at the abutting portion by relatively moving the peripheral portion along the abutting portion in a pressed state while stirring.

  Further, Patent Document 4 discloses a temporary attachment method using a friction stir welding for friction stir welding of plate materials at a predetermined pitch while backstepping from the end side to the start side of the continuous friction stir welding. It is described that bonding is performed.

Japanese Patent No. 4838385 Japanese Patent No. 4838388 JP 2000-94156 A JP 2002-1551 A

FIG. 1 is a schematic view of stir welding using a conventional double-side friction stir welding apparatus. The double-sided friction stir welding apparatus includes a shoulder portion 51 having a large-diameter shoulder portion 41 and an upper friction stir welding tool 40 having a small-diameter probe 42 at an end thereof, and a concave portion 52 having a diameter substantially larger than the probe 42. It comprises a lower friction stir welding tool 50 provided. In FIG. 1, θ ₁ and θ ₂ are rearward tilt angles with respect to the joining direction of the upper friction stir welding tool 40 and the lower friction stir welding tool 50.

  At the time of joining, in a state where the two friction stir welding tools 40, 50 are rotated in opposite directions, positioning is performed so as to match the mating surface of the joining portion of the aluminum members 10, 20 where the axes of the probes 42 are abutted, As shown in FIG. 2, the upper and lower friction stir welding tools 40 and 50 are moved along the mating surfaces while the friction stir welding tools 40 and 50 are clamped, and the friction stir welding is performed.

  By joining the aluminum member using such a double-sided friction stir welding apparatus, unlike the conventional friction stir welding, the shoulder portion 41 and the probe 42 of the upper friction stir welding tool 40 can be seen from both the front and back surfaces of the aluminum members 10 and 20. Because the frictional heat generated by the rotation of the shoulder 51 of the lower friction stir welding tool 50 is input, the amount of heat input is high, the joining speed is high, and the entire mating surfaces can be joined firmly. It becomes.

  FIG. 2 is a cross section of the joint portion 30 of the aluminum members 10 and 20 joined by the double-side friction stir welding apparatus. While clamping the shoulder 41 of the upper friction stir welding tool 40 and the shoulder 51 of the lower friction stir welding tool 50 from both the front and back surfaces of the aluminum members 10 and 20, the probe 42 of the upper friction stir welding tool 40 covers the entire mating surface. Since the agitation joining is performed, the cross section of the joining portion 30 has a symmetrical shape in the plate thickness direction of the aluminum members 10 and 20, and the joining strength is excellent, and a high-quality joining surface can be obtained.

Thus, the double-sided friction stir welding apparatus has an excellent feature that enables high-quality stir welding at high speed. However, as a side effect of increasing the joining speed, the running resistance increases, and accordingly, a strong spreading force is generated in the direction of expanding the butted surfaces of the aluminum members 10 and 20.
For this reason, a gap as shown by 70 in FIG. 3 is generated, and in some cases, the gap 70 at the abutting portion becomes more than allowable, and sufficient friction stir welding is not performed, and a defect may occur in the bonded portion. .

  Therefore, conventionally, as shown in Patent Documents 1 and 2, the upper and lower friction stir welding tools 40 and 50 are moved along the mating surfaces while firmly gripping both sides of the mating surfaces of the aluminum members 10 and 20. Thus, friction stir welding is performed. For this reason, a pair of upper and lower gripping devices for gripping strongly over the entire length of the mating surfaces of the aluminum members 10 and 20 are required, leading to an increase in size and cost of friction stir welding equipment.

In addition, the length that can be continuously stirred and joined is limited by the length in the mating surface direction of the upper and lower gripping devices. Therefore, a long aluminum material as long as 20 m to 25 m that is used for the structure of a railway vehicle is continuously used. There was a problem that it could not be joined.
For this reason, in Patent Document 3 described above, vertical ribs are provided on the outer sides of both aluminum members to be abutted, and the ribs are guided by a guide roller so that both aluminum members are conveyed while maintaining the abutting of both. It is shown that temporary joining is performed with a friction stir welding tool for temporary joining, and main joining is simultaneously performed with a subsequent friction stir welding tool.

However, in this prior art, it is necessary to form vertical ribs on the outside of both aluminum members, and in order to form a flat plate after joining, it is necessary to cut out the ribs, resulting in an increase in manufacturing cost. Moreover, a large amount of unnecessary aluminum members may be generated.
Also, with long materials, if there is no support base for supporting both aluminum members over the entire length on the upstream side and downstream side of the front and rear receiving rollers, the aluminum member will bend and the product quality will be reduced. Become. In addition, it is necessary to provide both a temporary joining apparatus provided with a friction stir welding tool for temporary joining and a main joining apparatus provided with a friction stir welding tool for main joining, resulting in high cost of the joining equipment itself. there is a possibility.

  Further, Patent Document 4 describes that temporary friction stir welding is performed at a predetermined pitch while backstepping from the end side to the start side of continuous friction stir welding. The theme is to suppress the expansion of the groove at the time of joining, and the temporary joining process takes time due to the back step. And since temporary joining is intermittently performed using the same joining tool as this joining, the joint intensity | strength of each temporary joining point must be raised, and also a big expansion force generate | occur | produces in each temporary joining point.

  Therefore, for example, in a state where the aluminum members are abutted with each other on the pedestal, and the opposite side surface of the mating surface is fixed by the clamp device, the mating surface is intermittently temporarily joined by arc welding such as MIG welding in which the spreading force does not act. By welding, it is conceivable to prevent expansion of the mating surface during the main joining by double-side frictional stirring without using a strong gripping device or the like.

However, in such temporary joining welding, it is necessary to provide an arc welding apparatus separately and perform temporary joining in the pre-process of the main joining.
For this reason, the cost of the joining equipment is also increased, setup by the operator is required, continuous joining cannot be performed, and the original characteristics of the double-side friction stir welding apparatus cannot be utilized.

In addition, a large heat load is applied to the temporary joint by arc welding, and the molten aluminum material is solidified in a state where the metal composition of the welding rod is mixed.
For this reason, as shown in FIG. 4, as shown in FIG. 5, at the time of the main joining, at the time of the stir welding at high speed along the mating surfaces by the double-side friction stir welding, when passing through the temporary joining portion 31 by arc welding. In addition, there is an extremely high possibility that the defective portion 32 and the bonding quality are lowered due to poor stirring.

  In order to minimize such poor bonding and deterioration in bonding quality, it is necessary to minimize arc welding, and at any intervals depending on the thickness of the mating surfaces of the aluminum members and the bonding length. However, there is a problem that the determination of what strength should be used for temporary joint welding must depend on the high skill of the operator.

  Therefore, the object of the present invention is to provide the minimum necessary temporary joining and the main joining by friction stir welding without providing a special device for performing temporary joining welding and without depending on the high skill of the operator. It is to solve the above-mentioned problem by making it possible to perform continuously.

In order to solve the above-mentioned problems, in the present invention, the double-sided friction stir welding using a double-sided friction stir welding apparatus is used to perform the minimum necessary temporary joining, and at the time of the main joining in the next step of stirring the entire mating surface. This realizes the minimum bonding strength required to hold the mating surface against the spreading force generated.
More specifically, for example, the configuration described in the claims is adopted. The present invention includes a plurality of means for solving the above-described problems. To give an example, the friction stir welding method of the present invention includes the first and second surfaces of the joint portion of the two metal plates on the first side and the rear side. And the second friction stir welding tool are arranged so as to oppose each other, and the first and second friction stir welding tools are used to friction stir the joint, thereby joining the two metal plates. In the method, as the first and second friction stir welding tools, a friction stir welding tool capable of obtaining a desired depth of stirring at the time of friction stirring is selected, and in the state where the front side and the back side of the joint are pressed, The friction stir welding tool and the joint are relatively moved along the first joining step for continuous temporary joining, and as the first and second friction stir welding tools, the shoulder part and the Provided with a probe protruding from the shoulder A combination of the friction stir welding tool and the friction stir welding tool having at least one recess for housing the probe when joining the two metal plates, and pressing the front side and the back side of the joint In this state, the second joining step is performed by moving along the joining portion and continuously performing the main joining.

  Moreover, the double-sided friction stir welding apparatus of the present invention for efficiently performing the above-described friction stir welding method includes a first friction stir welding tool and a second friction stir welding tool on the front side and the back side of the joining part of two metal plates. In the double-sided friction stir welding apparatus for joining the two metal plates by friction stir of the joint by using the first and second friction stir welding tools. A tool rotation driving device that rotationally drives the first and second friction stir welding tools mounted so as to face the front surface side and the back surface side of the bonding portion of the plate, and the first device mounted on the tool rotation driving device. And a tool pressing device that moves the second friction stir welding tool in a direction approaching each other and presses the first and second friction stir welding tools against the front surface side and the back surface side of the joint portion of the metal plate, and Attached to the tool rotation drive A moving device that relatively moves the first and second friction stir welding tools and the joint; and an exchange function of the first and second friction stir welding tools; When the friction stir welding tool for temporary joining that provides a desired stirring depth during friction stirring is installed as the friction stir welding tool of No. 2, the two metal plates are aligned at a predetermined stirring depth. Friction stir welding tool having a shoulder portion and a probe projecting from the shoulder portion as the first and second friction stir welding tools, and joining the two metal plates When a friction stir welding tool for main joining, sometimes having at least one recess for housing the probe, is mounted, the mating surfaces of the two metal plates are continuously main joined. Tool pressing equipment ; And a and joining controller for controlling the mobile device.

According to the present invention, prior to performing the main joining of the joining surfaces of the two metal plates by the double-side friction stir welding, the same double-side friction stir welding apparatus is used in advance for the expansion force generated during the main joining. With the friction stir welding tool for temporary joining that can obtain the minimum necessary friction stirring depth that can be withstood, temporary joining can be efficiently performed in a short time from both the upper and lower surfaces of the mating surfaces.
Thereby, it is possible to always keep the butt of the metal plates in an optimum state against the spreading force generated when performing the main joining by the friction stir welding without depending on the skill of the operator.
In addition, the amount of provisional joining can be minimized as compared with provisional joining only on one side, and impurities and excessive temperature load are not applied to the metal plate. And high-quality bonding can be realized.

FIG. 1 is a schematic view of a conventional double-side friction stir welding tool. FIG. 2 is a cross-sectional view of a joint portion by double-side friction stir welding. FIG. 3 is a schematic view of stir welding using a conventional double-side friction stir welding tool. FIG. 4 is a schematic diagram in the case where the main joining is performed by the double-side friction stir welding apparatus after the temporary joining by MIG welding. FIG. 5 is a diagram showing a defect portion that occurs when a temporary joint portion by MIG welding is subjected to main joining by double-side friction stir welding. FIG. 6 is a schematic diagram of a double-sided friction stir welding apparatus based on Example 1. FIG. 7 is a diagram illustrating a state when temporary bonding is started based on the first embodiment. FIG. 8 is a diagram illustrating a first example of the temporary stir friction stir welding tool used in the first embodiment. FIG. 9 is a view showing a cross-section of a tack joint formed by the friction stir welding tool of FIG. FIG. 10 is a diagram illustrating a second example of the friction stir welding tool for temporary joining used in the first embodiment. FIG. 11 is a view showing a cross section of a temporary joint formed by the friction stir welding tool of FIG. FIG. 12 is a front view of the double-sided friction stir welding apparatus according to Example 2 as viewed from the longitudinal direction of the aluminum member. FIG. 13 is a plan view of a double-sided friction stir welding apparatus based on the second embodiment. FIG. 14: is the front view which looked at the double-sided friction stir welding apparatus based on Example 3 from the longitudinal direction of the aluminum member. FIG. 15 is a plan view of a double-sided friction stir welding apparatus based on the third embodiment. FIG. 16: is the front view which looked at the double-sided friction stir welding apparatus based on Example 4 from the longitudinal direction of the aluminum member. FIG. 17 is a plan view of a double-sided friction stir welding apparatus based on the fourth embodiment. FIG. 18 is a front view of the double-sided friction stir welding apparatus according to Example 5 as viewed from the longitudinal direction of the aluminum member. FIG. 19 is a plan view of a double-sided friction stir welding apparatus based on the fifth embodiment.

  Embodiments of the present invention will be described below with reference to FIGS. In addition, about the same thing as the conventional double-sided friction stir welding apparatus, the same code | symbol is attached | subjected and description is abbreviate | omitted.

[Example 1]
FIG. 6 is an overall schematic diagram of the present embodiment, and particularly shows a double-sided friction stir welding apparatus for efficiently joining two long materials.
As described above, particularly in the case of a long material, the end face and the entire surface of the long material are strengthened over the entire length of the long material in order to withstand the strong spreading force acting during the main joining and to prevent plastic deformation of the aluminum member. Unless a large facility that can be restrained is used, it is impossible to perform the main joining in one step.

  Therefore, the double-sided friction stir welding apparatus of this embodiment is provided with two tables 100A and 100B on which each of the long aluminum members 10 and 20 as metal plates can be placed over the entire longitudinal direction, and aluminum as metal plates. In a state where the members 10 and 20 are brought into contact with each other, both outer end faces can be restrained by a restraining device 60 arranged at regular intervals. A constant distance D is provided between the tables 100A and 100B along the mating surface of the joint where the aluminum members 10 and 20 are abutted, and the upper friction stir welding tool 40 positioned above the mating surface and The lower friction stir welding tools 50 are disposed below the mating surfaces so as to face each other.

  That is, an upper rail is installed above both tables 100A and 100B, and the upper friction stir welding tool 40 including the tool drive motor is attached to a traveling device that travels on the upper rail and performs multi-axis control. The movement position is controlled along the position directly above the mating surfaces of the aluminum members 10 and 20 by the NC control device (bonding control device).

  On the other hand, on the floor surface on which both tables 100A and 100B are installed, a floor rail is installed along the gap between the two tables, and the lower friction stir welding tool 50 includes the tool drive motor and the floor surface. It is attached to a traveling device that travels on a rail. By controlling this traveling device by the NC control device, it moves along the position immediately below the mating surfaces of the aluminum members 10 and 20 while maintaining the optimal facing position in synchronization with the upper friction stir welding tool 40. The position is controlled.

  In this embodiment, the two tables 100A and 100B are fixed, and the upper friction stir welding tool 40 and the lower friction stir welding tool 50 are always opposed to each other along the mating surfaces of the aluminum members 10 and 20. The movement position was synchronized. However, the present invention is not limited to this, and both the upper friction stir welding tool 40 and the lower friction stir welding tool 50 are fixed so as to oppose each other at an optimum facing position, and both tables 100A and 100B are controlled by the NC control device. As a table, the mating surfaces of the aluminum members 10 and 20 restrained by the restraining device 60 may be moved along the opposing positions of the stationary upper friction stir welding tool 40 and the lower friction stir welding tool 50.

  Even in this case, it goes without saying that the double-side friction stir welding apparatus itself has a function of adjusting the positions of the upper friction stir welding tool 40 and the lower friction stir welding tool 50 in response to a command from the NC controller. Nor. By this position adjustment function, the position of the upper friction stir welding tool 40 and the lower friction stir welding tool 50 facing each other is adjusted to the mating surface of the aluminum members 10 and 20 constrained by the moving tables 100A and 100B. Is done. The same applies to the other embodiments.

Now, the double-sided friction stir welding apparatus itself has the same structure as that of FIG. 1, but in this embodiment, using a tool change tool or the like, a temporary stirring friction stir welding tool and a main joining friction stirrer are used. It is comprised so that a joining tool can be replaced | exchanged, In order to determine stirring depth according to the temporary joining mode mentioned later using FIGS. 7-11, and this joining mode, the gap | interval of each friction stir welding tool, joining The backward tilt angles θ ₁ and θ ₂ (see FIGS. 8 and 10) with respect to the direction can be automatically controlled by the NC control device. The agitation depth is the thickness dimension of the temporary joint formed by stirring both aluminum members at the mating surface when temporarily joining along the mating surface with a friction stir welding tool for temporary joining. means.

  Hereinafter, both tables 100A and 100B are fixed, and the friction stir welding tool for temporary joining and the friction stir welding tool for main joining are switched and used, and the opposing positions of the upper and lower friction stir welding tools are controlled by the NC controller. The procedure for joining the aluminum members will be described by taking, as an example, a case in which the temporary joining and the main joining are sequentially performed along the mating surfaces of the aluminum members 10 and 20 so as to be maintained.

[Step 1]
First, the long aluminum members 10 and 20 are transported on both the tables 100A and 100B, and are positioned so that their mating surfaces coincide with the central portion of the gap D between the tables 100A and 100B.

[Step 2]
Next, both end surfaces (counter mating surfaces) of the aluminum members 10 and 20 are restrained at regular intervals by restraining devices 60 provided on both longitudinal sides of the tables 100A and 100B.
In addition, since the restraint device 60 performs the friction stir welding at the minimum required stirring depth as will be described later in the temporary bonding in the next step, the expanding force generated can be suppressed to the minimum necessary. For this reason, what is necessary is just to hold | maintain the side surface on the opposite side to the mating surface of both the aluminum members 10 and 20 so that a clearance gap may not generate | occur | produce in a mating surface according to the expansion force generate | occur | produced at the time of temporary joining. Therefore, for example, by controlling the hydraulic pressure or electric actuator that operates the restraint device 60 by sequence control using the NC control device, switching between restraint and release is performed.

[Step 3]
First, friction stir welding tools 80 and 90 for temporary joining, which will be described later with reference to FIGS. 8 and 10, are attached to the double-side friction stir welding apparatus as shown in FIG. , 20 in the state of being rotated in front of the joining start end of the joint 20, the NC control device, the central axis of the friction stir welding tools 80, 90 for temporary joining, the aluminum members 10, 20 directly above the butted surface Position.

[Step 4]
Next, the optimum value of the friction stirring depth at the time of temporary joining by the friction stir welding tools 80 and 90 for temporary joining and the joining speed in the mating surface direction is determined.
At the time of the main joining, the shoulder portion 41 and the upper friction stir welding tool 40 having the probe 42 at the end thereof described in FIG. 1 and the shoulder portion 51 having the concave portion 52 having a diameter substantially larger than the probe 42 are provided. Using the friction stir welding tool composed of the lower friction stir welding tool 50, the probe 42 is passed through the mating surface, and the entire surface is friction stir welded.

At this time, the diameters of the shoulder portion 41 and the probe 42 of the upper friction stir welding tool 40 are selected according to the elastic modulus in the width direction determined for each material of the aluminum member (aluminum alloy) and the thickness thereof. The expansion force acting during the main joining generally follows the thickness of the aluminum member, the diameter of the selected probe 42, and the upper friction stir welding tool 40 and the lower friction stir welding tool 50 along the mating surfaces. It depends on the moving speed, that is, the joining speed. Therefore, the relationship between the thickness, the diameter of the selected probe 42, the joining speed, and the spreading force is previously stored in a database for each material of the aluminum member.
In the experimental results, it is found that when the same upper friction stir welding tool 40 and lower friction stir welding tool 50 are used, the spreading force generated during the main welding is substantially proportional to the welding speed.

On the other hand, at the time of temporary joining, as will be described later, as the upper and lower friction stir welding tools, the height of the probe including zero is less than 1/2 of the plate thickness, and the probe diameter is accordingly increased. However, by using a friction stir welding tool having a diameter smaller than the diameter of the probe 42 of the upper friction stir welding tool 40 used at the time of the main joining, the friction stir welding is continuously performed at a desired stirring depth above and below the mating surfaces. The bonding strength obtained by this depends on the stirring depth with respect to the upper and lower surfaces of the mating surfaces. In addition, a desired value can be obtained for the stirring depth at the time of temporary joining mainly depending on the height of the probe. For this reason, a desired stirring depth can be obtained by selecting friction stir welding tools having different probe heights and diameters or using a friction stir welding tool capable of adjusting the probe height.
When the thin aluminum member is fully joined, the probe height of 0, that is, a probeless friction stir welding tool can be selected as the friction stir welding tool for temporary joining.

In general, the bonding strength obtained by temporary bonding can be obtained by multiplying the bonding areas formed above and below the mating surfaces by the tensile strength of the aluminum material.
Since the bonding area formed by temporary bonding is proportional to the stirring depth, the mixing depth for the upper and lower surfaces at the time of temporary bonding and the bonding strength obtained thereby are compiled into a database for each composition of the aluminum material (aluminum alloy). In addition, by selecting the minimum required agitation depth that can withstand the expansion force that occurs during the main joining, the expansion force that occurs during the temporary joining can be applied to the both ends of the aluminum material in the width direction using a very general restraining device. The continuous temporary joining is performed only by restraining, and after the temporary joining is completed, the main joining is continuously performed as it is.

In addition, since the expansion force acting at the time of temporary bonding also depends on the stirring depth and the bonding speed, it can withstand the overall process time from the temporary bonding to the completion of the main bonding and the expansion force at the time of temporary bonding. The agitation depth and the joining speed at the time of temporary joining can be determined by balance with the strength of the restraining device.
Assuming that the main joining is performed while using the restraining device used at the time of temporary joining, the interval (pitch) for installing the restraining device 60 withstands the spreading force at the time of provisional joining and the agitation depth obtained by provisional joining. In addition, it is preferable to select so as to withstand the spreading force generated during the main joining by the restraining force of the restraining device.

  As described above, the spreading force generated at the time of temporary joining can be minimized, and the smaller the stirring depth, the higher the joining speed in the mating surface direction. Temporary joining at a high speed can be performed only by restraining both end faces in the width direction of the member.

In addition, with the friction stir welding tools 80 and 90 for temporary joining, the thickness of the aluminum members 10 and 20 is determined as to what degree of stirring depth the vertical joining is performed on the mating surfaces of the aluminum members 10 and 20. Each alloy type is determined in advance from a database such as a correspondence table and input to the NC controller.
In addition, the necessary data is input to the storage device of the NC control device, and the specifications of the aluminum members 10 and 20 such as the thickness and the alloy type are input so that the NC control device can perform frictional stirring for temporary joining. You may make it set the stirring depth by the joining tools 80 and 90 automatically.

If the stirring depth at the time of temporary joining is determined in this manner, the NC control device positions the friction stir welding tools 80 and 90 for temporary joining with respect to the mating surfaces of the aluminum members 10 and 20 in the depth direction, and FIGS. 10, the optimum values of the rearward tilt angles θ ₁ , θ ₂ and the joining speed in the mating surface direction with respect to the traveling direction are determined, and continuously moved while moving in the joining direction using the friction stir welding tools 80 and 90 for temporary joining. Temporary joining is performed by typical double-sided friction stir welding.
FIG. 8 is a first example of a friction stir welding tool for temporary joining. Friction stir welding tools 80 and 90 for temporary joining have shoulder portions 81 and 91 and probes 82 and 92. By these probes 82 and 92, as shown in FIG. Temporary joining is possible in the range.
However, in order to prevent the friction stir welding tools 80 and 90 for temporary joining from contacting the probes, the total length of the probes 82 and 92 of the friction stir welding tools 80 and 90 for temporary joining is aluminum. It is necessary to be shorter than the plate thickness of the members 10 and 20.

  FIG. 10 shows a second example of the friction stir welding tools 80 and 90 for temporary joining. Unlike the friction stir welding tool for main welding shown in FIG. 1, the friction stir welding tool 80 for upper temporary welding and the friction stir welding tool 90 for lower temporary welding do not include the probe 42 or the recess 52. Further, flat and circular shoulder portions 81 and 91 having diameters reduced toward the upper and lower surfaces of the aluminum members 10 and 20 are provided. This tool has a probe height of 0, that is, a probeless friction stir welding tool, and is used for temporarily joining an aluminum member having a thin plate thickness.

  FIG. 11 is a cross-sectional view of the temporary joints 33 and 34 formed by the friction stir welding tool of FIG. 10, and the temporary joints 33 having a certain depth are formed on the upper and lower surface layers of the mating surfaces of the aluminum members 10 and 20. 34 is continuously formed along the mating surface, and the temporary joining is completed.

  The double-sided friction stir welding apparatus presses the friction stir welding tools 80 and 90 for temporary joining toward the aluminum members 10 and 20 by the NC control device. In this embodiment, the friction stir welding tools 80 and 90 for temporary bonding are rotated at a predetermined rotational speed during the temporary bonding process, and the friction stir welding tools 80 and 90 for temporary bonding are rotated with a predetermined pressing force. The temporary joint portions 33 and 34 are continuously formed by sandwiching and allowing them to self-run along the mating surfaces.

Friction stir welding tools 80 and 90 for both temporary joining to the aluminum members 10 and 20, tool rotation speed, pressing force, and friction stir welding tools 80 and 90 for both temporary joining with respect to the traveling direction, backward tilt angles θ ₁ and θ _2. Can be adjusted in various ways by the NC controller, so by automatically setting the optimum value in advance according to the thickness of the mating surfaces of the aluminum members and the joining length, the temporary joining process can be performed automatically and sequentially. It can be performed.

[Step 5]
When the above temporary joining process is completed, the main joining is performed by double-sided friction stir welding. For this reason, by using an automatic tool changer or the like, both temporary joining tools 80 and 90 are exchanged with friction stir welding tools 40 and 50 for main joining as shown in FIG. This is used to perform the main joining process.
Since the composition of the temporary joining portions 33 and 34 is performed by the above-described double-side friction stir welding for temporary joining, the composition of the aluminum members 10 and 20 is not changed at all without mixing the metal components of the welding rod. Therefore, no joint defect occurs in the temporary joint portions 33 and 34. In addition, the friction stirrer at the time of temporary joining stays at a predetermined stirring depth from the upper surface and the lower surface of the mating surfaces, and the stirring range seen from the vertical direction is limited compared to that at the time of main welding. All the parts are absorbed during the main joining, and the finished quality is not affected.

[Example 2]
In the first embodiment, the case where the joining surfaces of two aluminum members are joined has been described as an example. However, in this embodiment, a plurality of joining surfaces are joined at the same time. A case where four mating surfaces are joined simultaneously will be described as an example.

FIG. 12 is a front view of the joining equipment of the present embodiment as seen from the longitudinal direction of the abutted aluminum members, and FIG. 13 is a plan view.
The upper joining apparatus provided with the upper friction stir welding tool 40 and the upper joining apparatus provided with the lower friction stir welding tool 50 that are opposed to each other have four sets (upper joining) in the apparatus main body 1 corresponding to the four abutting surfaces. 40A and lower joining device 50A to upper joining device 40D and lower joining device 50D) are installed, and moving table 100, in which five aluminum members 10A to 10E are constrained in abutment with each other, is moved in the direction of the mating surface. It is something to be made.

  The moving table 100 is composed of five units 100A to 100E arranged in parallel with each other through a gap, respectively, along the traveling rails 101 installed on the floor surface, in FIG. 12, from the back side to the front side in FIG. In FIG. 13, they can move from the right side to the left side at the same speed in synchronization with each other. Note that each of the movement tables 100A to 100E is speed-controlled by the NC control device, and moves in synchronization with each other while always maintaining the same position.

The five aluminum members 10A to 10E are placed in contact with each other on the pedestals of the moving tables 100A to 100E, and are restrained by the restraining device 60 provided outside the moving tables 100A and 100E.
The aluminum members 10A and 10B are abutted so as to be located at the center of the gap between the moving tables 100A and 100B, and the upper friction stir welding tool 40 and the lower side of the upper joining device 40A are located directly above and below the abutting surface. The lower friction stir welding tool 50 of the joining device 40B is arranged to face each other.

  This is the same for other sets of upper and lower joining devices, and the upper friction stir welding tool and the lower friction stir welding tool correspond to the mating surfaces of the aluminum members 10A to 10E. They are deployed to face each other.

  Also in the present embodiment, similarly to the first embodiment, the moving tables 100A to 100E are intermittently moved, and temporary bonding is performed by the temporary stirring friction stir welding tools 80 and 90 for each temporary bonding position. After completion, continuous main joining is performed by the friction stir welding tools 40 and 50 for main joining. However, since the restraining device 60 restrains only the outer sides of the aluminum members 10A and 10E, the restraining device 60 restrains them when performing temporary joining and main joining of the mating surfaces of the aluminum members 10A to 10E. Therefore, in FIG. 15, each upper bonding apparatus is provided with pressing rollers 110 on both sides of the upper friction stir welding tool 40, and always or in conjunction with the upper friction stir welding tool 40. The ends of the members 10A to 10E are pressed between the moving tables 100A to 100E. Other configurations are the same as those of the first embodiment.

  According to the present embodiment, a plurality of mating surfaces can be bonded simultaneously in one process. In particular, in the manufacturing process of a railway vehicle structure, a plurality of aluminum members having a length of 20 m to 25 m and a width of several tens of centimeters, which are joined in the length direction, are used as the outer wall material. The manufacturing process can be drastically shortened. In the present embodiment, the case where the mating surfaces of the five aluminum members 10A to 10E are joined at the same time is taken as an example. However, a set of an upper joining device and a lower joining device is required according to each part of the structure for a railway vehicle. It is also possible to jointly join five or more aluminum members. Moreover, it may be switched so that a part of the set of the upper bonding apparatus and the lower bonding apparatus is paused and a smaller number of aluminum members are simultaneously bonded.

[Example 3]
In the second embodiment, the upper bonding devices 40A to 40D and the lower bonding devices 50A to 50D that face each other are fixed, and the moving table 100 is moved in the longitudinal direction along the respective mating surfaces of the aluminum members 10A to 10E. However, in this embodiment, the table 100 on which the aluminum members 10A to 10E are placed is fixed, and the respective sets of the upper bonding devices 40A to 40D and the lower bonding devices 50A to 50D are moved to temporarily bond and perform the main bonding. Is to do.

FIG. 14 is a front view of the joining equipment of this embodiment as seen from the longitudinal direction of the abutted aluminum members, and FIG. 15 is a plan view.
The apparatus main body 1 includes vertical walls 1A and 1B that are erected in the joining direction, and a moving frame 1C that moves on a traveling rail 101 provided on the upper surfaces of the vertical walls 1A and 1B. Upper joining devices 40A to 40D are attached to the moving frame 1C.

  On the other hand, the table 100 includes five fixed tables 100A to 100E arranged in parallel with a gap between each other, and a rail 102 is provided along the side surface of each fixed table. Lower bonding apparatuses 50 </ b> A to 50 </ b> D are provided in the gaps between the fixed tables so that they can move along the rails 102. In addition, you may provide the rail 102 in the gap | interval bottom part between each fixed table.

In this embodiment, the five aluminum members 10A to 10E are transported by the transport device from the upper side or the side of FIG. 15, and are positioned so as to abut at the center of the gap between the fixed tables 100A to 100E. Restrained by device 60.
In this state, the moving frame 1C is moved from the front side to the back side in FIG. 14 and from the left side to the right side in FIG. At that time, in the NC control device, the lower bonding devices 50A to 50D are opposed to the upper bonding devices 40A to 50D mounted on the moving frame 1C, and the upper bonding devices 40 and the lower bonding devices 50 are in the optimum positions. And run along the rails 102 provided on the side surfaces of the respective fixed tables.

  In addition, although temporary joining and this joining are performed similarly to Example 1, movement and position control of 1 C of moving frames and each lower side joining apparatus 50A-50D are NC control apparatuses according to temporary joining and this joining. Thus, sequential control is performed in synchronization with each other.

  Also in this embodiment, only the outer sides of the aluminum members 10A and 10E are restrained by the restraining device 60, so that temporary joining and main joining of the mating surfaces of the aluminum members 10A to 10E are performed. In order to restrain these, in FIG. 14, pressing rollers 110 are provided on both sides of each of the upper joining devices 40 </ b> A to 40 </ b> D, and each aluminum member 10 </ b> A˜ The end of 10E is pressed against the upper surface of the table. Other configurations are the same as those of the first embodiment.

[Example 4]
In the present embodiment, the table 100 on which the aluminum member 10 is placed is moved using a pair of the upper friction stir welding tool 40 and the lower friction stir welding tool 50 to continuously join the butt surfaces. .
FIG. 16 is a front view of the joining equipment of this embodiment as seen from the longitudinal direction of the butt aluminum member 10, and FIG. 17 is a plan view.

The U-shaped device main body 1 is fixed to the floor so as to be positioned on one end side (upper side in FIG. 17) of the moving table 100, and the upper friction stir welding tool 40 of the double-side friction stir welding device is shown in FIG. The upper body 1A is mounted on the right side of the upper frame 1A extending in the horizontal direction on the upper part of the apparatus main body 1.
The moving table 100 is composed of a table 100A on which the aluminum member 10 to be newly supplied and loaded is placed and a table 100B on which the joined aluminum member 10 is placed, and a gap is formed between the tables. Yes.

In this gap, the lower friction stir welding tool 50 is provided so that the lower welding device is installed on the floor and faces the upper friction stir welding tool 40.
The aluminum member 10 is sequentially supplied from the left side in FIG. 16 and from the upper side in FIG. 17, and after being abutted against the end face of the aluminum member that has been joined, the aluminum member 10 is restrained by the restraining device 60.

FIG. 17 shows the state immediately after joining the fourth aluminum member 10A after joining the three aluminum members 10B to 10D. The end surfaces of the aluminum member 10A and the aluminum member 10B are the table 100A and the table. The joint positions of the upper friction stir welding tool 40 and the lower friction stir welding tool 50 are positioned on the mating surfaces.
In this state, the moving tables 100A and 100B are united and moved along the traveling rail 101 from the back side to the front side in FIG. 16 and to the left side in FIG. Are performed sequentially.

At that time, as in the second embodiment, pressure rollers 110 are provided on both sides of the upper friction stir welding tool 40, and the third and fourth sheets are always or prior to joining in conjunction with the upper friction stir welding tool. The eye aluminum member 10 is restrained.
After the final joining of the third and fourth aluminum members 10 has been completed and the movable tables 100A and 100B have returned to the right end in FIG. 17, the aluminum member 10 is driven by a driving roller provided on the back surface of the movable table 100B. , The new aluminum member 10 is supplied from above by the loading device, is restrained by the restraining device 60 again, and the above-described temporary joining and main joining are repeated.

  Since the restraining position on the table 100B changes depending on the number of joined sheets, the restraining device 60 can move on the table 100A, and is linked with the NC controller together with the drive roller for moving the joined aluminum member 10. Be controlled. When the width of the aluminum member 10 is determined in advance, a plurality of restraining devices 60 are arranged for each width, and the corresponding restraining device 60 is also protruded from the table 100B and restrained by the NC control device. Good.

[Example 5]
In this embodiment, the pair of upper and lower joining devices are moved to continuously join the butted surfaces of the aluminum members 10 placed on the fixed table 100.
FIG. 18 is a front view of the joining equipment of the present embodiment as seen from the longitudinal direction of the abutted aluminum members, and FIG. 19 is a plan view.

A traveling rail 101A is provided horizontally on the upper side surface of the apparatus main body 1, and an upper joining device having an upper friction stir welding tool 40 is attached to an upper moving frame 2 that moves along the rail. .
The fixed table 100 includes a table 100A on which the newly supplied aluminum member 10 is placed and a table 100B on which the joined aluminum member 10 is placed, and a gap is formed between the tables.

On the other hand, a traveling rail 101B is horizontally provided on the lower side surface of the apparatus main body 1, and a lower joining apparatus provided with a lower friction stir welding tool 50 on a lower moving frame 3 that moves along the rail 101B. Is attached.
Thus, the NC control device moves the upward moving frame so that the upper friction stir welding tool 40 and the lower friction stir welding tool 50 can move while maintaining a state of facing each other along the gap between the table 100A and the table 100B. 2 and the movement and stop of the downward movement frame 3 are controlled.

  The aluminum member 10 is sequentially supplied from the left side in FIG. 18 and from the upper side in FIG. 19, and after being abutted against the end face of the aluminum member that has been joined, the aluminum member 10 is restrained by the restraining device 60.

FIG. 19 shows a state immediately after joining the three aluminum members 10B to 10D and immediately before joining the four aluminum members 10A. The longitudinal end surfaces of the aluminum member 10A and the aluminum member 10B are connected to the table 100A. It is abutted at the center of the gap of the table 100B, and is positioned at the joining position by the upper friction stir welding tool 40 and the lower friction stir welding tool 50.
In this state, the upper moving frame 2 and the lower moving frame 3 are controlled by the NC control device, and the traveling rail 101A, while maintaining the state in which the upper friction stir welding tool 40 and the lower friction stir welding tool 50 face each other. In FIG. 18, the paper moves from the front surface to the back surface in FIG. 18, and to the left side in FIG. 19.

  At that time, as in the second embodiment, the pressing rollers 110 are provided on both sides of the upper friction stir welding tool 40, and the aluminum members 10A and 10B are connected to the upper friction stir welding tool 40 at all times or before the joining. to bound.

  The drive roller provided on the back surface of the fixed table 100B in the same manner as in Example 4 with the final joining of the aluminum members 10A and 10B finished and the upper moving frame 2 and the lower moving frame 3 returning to the left end in FIG. Thus, the aluminum member 10 is moved downward by the width of the aluminum member 10, a new aluminum member 10 is supplied from the upper side by the loading device, and is again restrained by the restraining device 60 between the fixed table 100 </ b> A and the temporary joining described above. Repeat this bonding.

  Note that the restraining position on the fixed table 100B changes depending on the number of joined sheets, so that the restraining device 60 can move on the table 100A. The restraint device 60 is interlocked and controlled by an NC control device together with a drive roller that moves the joined aluminum member 10. When the width of the aluminum member 10 is determined in advance, a plurality of restraining devices 60 are arranged for each width, and the corresponding aluminum member restraining device 60 is protruded from the fixed table 100B and restrained by the NC control device. It may be.

In the above embodiment, a long one is assumed. However, by adjusting the length of the pedestal, it is possible to cope with a short one, and a pair of pieces for gripping strongly over the entire mating surface of the aluminum members 10 and 20. A vertical gripping device can be dispensed with.
Further, the present invention can be applied to any metal plate other than aluminum as long as it is capable of friction stir welding.

DESCRIPTION OF SYMBOLS 1 Apparatus main body, 10, 20: Aluminum member, 30: Joining part, 31: MIG temporary joining part, 32: Welding defect, 33, 34: Temporary joining part of friction stir welding, 40: Friction stir welding tool (for main joining) Upper side), 41: Shoulder part, 42: Probe, 50: Friction stir welding tool (lower side for main welding), 51: Large diameter part, 52: Hole part, 60: Restraint device, 70: Gap between facing surfaces, 80, 90: Friction stir welding tool for temporary joining, 81, 91: Shoulder portion of friction stir welding tool for temporary joining, 82, 92: Probe provided on the friction stir welding tool for temporary joining, 100; Table, 101, 102: Rail, 110: Pressing roller

Claims (7)

A first friction stir welding tool and a second friction stir welding tool are arranged opposite to each other on the front surface side and the back surface side of the mating surfaces of the two metal plates. In the double-sided friction stir welding method for joining the two metal plates,
As the first and second friction stir welding tools, select a friction stir welding tool that provides a desired depth of stirring during friction stirring, and press the front and back sides of the mating surfaces along the mating surfaces. A first joining step in which the friction stir welding tool and the two metal plates are relatively moved and temporarily joined together,
As the first and second friction stir welding tools, a friction stir welding tool including a shoulder portion and a probe protruding from the shoulder portion, and at least one dent portion for housing the probe when the two metal plates are joined A combination of friction stir welding tools having, and in a state of pressing the front surface side and the back surface side of the mating surface, moving along the mating surface, and continuously joining the second joining step A double-sided friction stir welding method.   Prior to the first joining step, the expansion force acting on the mating surfaces of the two metal plates is called from the database at the time of the second joining step, and a provisional strength that can withstand the spreading force is obtained. The double-sided friction stir welding method according to claim 1, further comprising a step of determining a stirring depth at the time of joining. The first and second friction stir welding tools are arranged opposite to each other on the front side and the back side of the joint portion of the two metal plates, and the joint portion is formed by the first and second friction stir welding tools. In a double-sided friction stir welding apparatus that joins the two metal plates by friction stirring,
A tool rotation driving device that rotationally drives the first and second friction stir welding tools mounted so as to oppose the front surface side and the back surface side of the joint portion of the two metal plates;
A tool pressing device that moves the first and second friction stir welding tools mounted on the tool rotation driving device in directions approaching each other and presses the metal plate against the front surface side and the back surface side;
A moving device for relatively moving the first and second friction stir welding tools and the two metal plates attached to the tool rotation driving device;
An exchange function of the first and second friction stir welding tools,
As the first and second friction stir welding tools, when a friction stir welding tool for temporary joining that provides a desired stirring depth at the time of friction stirring is mounted, the two pieces are used at a predetermined stirring depth. A friction stir welding tool including a shoulder portion and a probe protruding from the shoulder portion as the first and second friction stir welding tools; When the friction stir welding tool for main joining, which has at least one concave portion for housing the probe at the time of joining the two metal plates, is mounted, the joining portions of the two metal plates are continuously connected. A double-sided friction stir welding apparatus comprising the tool pressing device and a welding control device for controlling the moving device so as to be joined to each other.   The friction stir welding tool for temporary joining includes at least one probe formed to protrude from the shoulder portion, and the total length of the probes is shorter than the thickness of the two metal plates. The double-sided friction stir welding apparatus according to claim 3. A plurality of tables arranged parallel to each other with a gap in the longitudinal direction;
A restraining device that is attached to the outer edge of the outermost table of the tables and holds both end surfaces of the metal plates placed on the tables in a state of being butted against each other with the gap between them; The double-sided friction stir welding apparatus according to claim 3 or 4, characterized in that:   The double-sided friction stir welding apparatus according to claim 5, wherein the plurality of tables are fixed tables, and the joining control device controls a moving speed of the tool rotation driving device.   The double-sided friction stir welding apparatus according to claim 5, wherein the plurality of tables are movement tables that move integrally, and the joining control device controls a moving speed of the moving table.