JP2007268558A - Apparatus and method for friction stir welding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and a method for friction stir welding which can improve the efficiency in a small quantity production, and fully bear a reaction force from a rotary tool. <P>SOLUTION: The apparatus 1 for friction stir welding includes: the rotary tool 30 having a probe 32 at the tip thereof; a holding device 20 for holding this rotary tool 30; a roller 50 fixed to the holding device 20 so as to face the rotary tool 30; and a workpiece table T fixed with two welding materials W1, W2 to be weld and disposed between the rotary tool 30 and the roller 50. The workpiece table T is mounted on a multi-articular robot 10, and independently movable relative to the holding device 20. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a friction stir welding apparatus and a friction stir welding method.

  In recent years, a friction stir welding technique has been widely applied as a joining technique with less distortion and deformation due to the thermal effect during joining. Friction stir welding is a method in which a rotating tool is pressed against a contact portion (joint portion) between two workpieces while being rotated, and the periphery of the contact portion is plastically flowed by the rotational force of the rotating tool. This is a technique for joining materials to be joined together.

As a friction stir welding apparatus, for example, the following is known (see Patent Document 1).
The friction stir welding apparatus described in Patent Document 1 has a C-shaped holding arm to which a welding tool and a cradle are fixed at opposing positions. In this friction stir welding apparatus, a holding arm is attached to the tip of an arm of an articulated robot (hereinafter referred to as “robot arm”), and can be moved three-dimensionally via the robot arm. On the other hand, the material to be joined is set on a work table having a feed roller attached to the lower surface. The friction stir welding device adjusts the upper surface of the cradle to contact the feed roller so that it can receive a reaction force, and then inserts it into the workpiece while rotating the rotary tool. The workpieces are joined together by being moved along the line.
JP 2002-103061 A (paragraphs 0027-0033)

  However, the friction stir welding apparatus according to the prior art employs a configuration in which the cradle is fed by the feed roller of the work table, and therefore can move only in the feed direction of the feed roller during the joining operation. For this reason, each time the direction of the material to be bonded is changed, it is necessary to change the direction of the material to be bonded and set it again on the work table, which makes it impossible to increase the efficiency of small-volume production. It was.

  Further, since the rotary tool is attached to the articulated robot side, there is a problem that a large load is applied to the articulated robot when the reaction force generated by the rotary tool is received by the rigidity of the robot arm itself. Furthermore, when the reaction force from the lower side of the material to be joined is generated by the holding arm cradle, there is a problem that a sufficient reaction force cannot be obtained for joining a long distance.

  Then, this invention makes it a subject to provide the friction stir welding apparatus and friction stir welding method which can fully endure the reaction force from a rotary tool while improving the efficiency at the time of a small quantity production.

  In order to solve the above-described problem, the invention according to claim 1 is a rotating tool having a probe at a tip, a holding device that holds the rotating tool, and a roller that is fixed to the holding device so as to face the rotating tool. Two workpieces to be joined are fixed, and a work table placed between the rotary tool and the roller, the friction stir welding apparatus, wherein the work table is attached to the articulated robot It is attached and it is comprised so that it can move independently with respect to the said holding | maintenance apparatus.

  According to the first aspect of the present invention, the work base on which the two materials to be joined are fixed is moved by the articulated robot, and the work base is disposed between the rotary tool and the roller. Then, the roller is brought into contact with the lower surface of the work table, and the lower surface of the work table is supported by the roller. Then, the work table is moved by the articulated robot so that the rotating tool follows the joining line of the workpieces. As described above, since the work table is configured to be movable by the articulated robot, two workpieces can be joined along a predetermined (programmed) joining line. In addition, it is configured to be movable by attaching the work table to the articulated robot, and the reaction force from the rotating tool is received by the holding device, not the articulated robot. Can withstand enough.

  According to a second aspect of the present invention, there is provided a rotary tool having a probe at a tip, a holding device for holding the rotary tool, a roller fixed to the holding device so as to face the rotary tool, the rotary tool, and the A friction stir welding method for joining two materials to be joined using a friction stir welding apparatus provided with a work table disposed between rollers, wherein the work tables on which the two materials to be joined are fixed And an inserting step of pressing and inserting the rotating tool while rotating the rotating tool with respect to the material to be joined in a state where the lower surface of the work table is supported by the roller. A flow step of plastically flowing the periphery of the rotating tool in the material to be joined by frictional heat generated by the rotation of the rotating tool, and the rotating tool as a joining line of the material to be joined. In Migihitsuji, characterized in that it comprises a bonding step of bonding the two said members to be joined is moved by the work platform articulated robot.

  According to the invention which concerns on Claim 2, it is along a predetermined (programmed) joining line by moving a work stand with an articulated robot so that a rotary tool may follow the joining line of a to-be-joined material. Two materials to be joined can be joined. In addition, it is configured to be movable by attaching the work table to the articulated robot, and the reaction force from the rotating tool is received by the holding device, not the articulated robot. Can withstand enough.

  According to the friction stir welding apparatus and the friction stir welding method according to the present invention, two workpieces can be moved and joined in arbitrary directions by moving the work table by an articulated robot. Efficiency in production can be improved. In addition, since the rotary tool is held by the holding device, the reaction force from the rotary tool can be sufficiently resisted by the holding device.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the drawings to be referred to, FIG. 1 is a perspective view of a friction stir welding apparatus according to the present embodiment.

[Friction stir welding equipment]
As shown in FIG. 1, the friction stir welding apparatus 1 includes a work table T held by an articulated robot 10, a holding device 20 disposed in the vicinity of the articulated robot 10, and a rotation attached to the holding device 20. The tool 30 includes a driving unit 40 that drives the rotating tool 30, a roller member 50 that is attached to the holding device 20, and a control unit 60 (see FIG. 2).
Hereinafter, for convenience of description, the holding device 20, the rotary tool 30, the drive unit 40, and the roller member 50 may be collectively referred to as an apparatus main body E.

  The articulated robot 10 is a moving device for moving the work table T three-dimensionally, a turntable 11, a first arm 12 connected to the tip from the turntable 11 side, A second arm 13 and a third arm 14 (robot arm) are provided.

  The turntable 11 is configured to be rotatable about an axis substantially perpendicular to the base 15 installed on the installation surface. The first arm 12 is attached to the turntable 11 via a joint 16a pivotally supported on the turntable 11, and is rotatable around the joint 16a. The second arm 13 is attached via a joint 16b pivotally supported on the first arm 12, and is rotatable around the joint 16b. The third arm 14 is attached to the second arm 13 via a joint 16c, is rotatable about the joint 16c, and can rotate about an axis substantially perpendicular to the joint 16c. It has become. A work table T is attached to the tip of the third arm 14.

  The work table T is a plate-shaped table to which the materials to be joined W1 and W2 are fixed. The work table T is formed of, for example, a highly rigid member such as high-speed steel and can sufficiently withstand the pressing force of the rotary tool 30 described later. The fixing means for fixing the workpieces W1 and W2 to the work table T is not shown, but known fixing means can be applied. For example, means for covering the both ends in the longitudinal direction of the materials to be joined W1 and W2 with a high-rigidity member and fixing the high-rigidity member to the work table T with bolts may be mentioned.

  In the articulated robot 10 to which the work table T is thus attached, each arm 12 is driven by driving the joint 16a, the joint 16b, the joint 16c, and the turntable 11 by a hydraulic system (not shown) as in the known articulated robot. -14 operate | moves and the work stand T attached to the front-end | tip of the 3rd arm 14 is movable three-dimensionally. That is, the work table T is configured to be movable independently of the holding device 20 described later.

  FIG. 2 is a diagram of the apparatus main body and the control unit according to the present embodiment. In the present embodiment, the vertical direction is determined with reference to the state of FIG.

  As shown in FIG. 2, the apparatus main body E includes a holding device 20, a rotating tool 30 attached to the holding device 20, a drive unit 40 that drives the rotating tool 30, and a roller member 50 attached to the holding device 20. And.

  The holding device 20 is a base formed in a substantially U-shape when viewed from the front, and is made of a material having high rigidity such as high-speed steel. The holding device 20 includes a rotating tool 30 on the upper side and a roller member 50 on the lower side, and the rotating tool 30 and the roller member 50 are opposed to each other.

  The rotary tool 30 is a tool for joining the workpieces W1 and W2, and includes a cylindrical body 31 and a probe 32 that protrudes coaxially from the tip of the body 31. The body part 31 is coupled to a drive part 40 described later. The probe 32 is a pin-shaped member having a diameter smaller than that of the body portion 31, and a screw is cut on the outer peripheral surface thereof. The length of the probe 32 is approximately the same as the thickness of the material to be joined W2. The body portion 31 and the probe 32 are formed of a material that is harder than the materials to be joined W1 and W2 and has heat resistance that can withstand frictional heat generated during joining.

  The drive unit 40 is disposed inside the upper portion of the holding device 20, and includes a pressure drive unit 41 that moves the rotary tool 30 forward and backward toward the materials W <b> 1 and W <b> 2, and a rotary drive unit 42 that rotates the rotary tool 30. It consists of.

  The pressure drive unit 41 is attached to a mount bracket B1 fixed to the upper part of the holding device 20, and includes a servo motor 41a, a ball screw 41b, a slide guide rail 41c, and a slide table 41d.

  The servo motor 41a transmits the rotational force to the ball screw 41b via the drive belt V. The ball screw 41b is a mechanism that converts the rotational force from the servo motor 41a into direct power and transmits it to the slide table 41d. The slide guide rail 41c is a rail for guiding the slide table 41d, and is attached in parallel to the ball screw 41b between the mount bracket B1 and the support portion B2. The slide table 41d is supported via a nut (not shown) that is screwed to the ball screw 41b, and is attached across the ball screw 41b and the slide guide rail 41c. The rotary tool 30 is attached to the slide table 41d via a rotation drive unit 42.

  In the pressurizing drive unit 41, the servomotor 41a is driven to rotate the ball screw 41b. This rotational force is transmitted to the slide table 41d as a direct power, and the slide table 41d is unidirectional along the slide guide rail 41c. To move to. Further, the slide table 41d is moved in the opposite direction by rotating the ball screw 41b in the reverse direction. Thereby, the rotary tool 30 can be moved back and forth toward the materials W1 and W2.

  The rotation drive part 42 is comprised with the servomotor, and is attached to the slide table 41d. The rotation shaft of the servo motor that is the rotation drive unit 42 is coupled to the rotation tool 30, and the rotation tool 30 can be rotated by driving the rotation drive unit 42.

  The roller member 50 supports the load by the rotary tool 30 that presses the workpieces W1 and W2 from the lower surface side of the work table T and guides its movement during the joining operation. The roller member 50 is a so-called caster, and includes a rotating shaft member 51 and a caster roller 52 attached to the rotating shaft member 51.

  The rotating shaft member 51 includes a shaft body 51a and a roller holder 51b provided on the shaft body 51a. The shaft main body 51a is attached to the holding device 20 so as to be rotatable on the same axis as the rotation axis of the rotary tool 30 (in a direction matching the axial direction). The rotating shaft member 51 can linearly receive the load from the rotating tool 30 because it coincides with the axial direction of the rotating tool. Further, by rotating the rotating shaft member 51, the caster roller 52 can be directed in all directions. The roller holder 51b is a U-shaped member, and supports the caster roller 52 inside thereof.

  The caster roller 52 has a roller shaft 52a orthogonal to the rotation shaft member 51 and a roller body 52b formed integrally with the roller shaft 52a. Both ends of the roller shaft 52a are supported by the roller holder 51b. The roller body 52b is a cylindrical member whose roller surface faces the rotary tool 30, and the roller shaft 52a passes through the center thereof. The roller body 52b rotates around the axis of the roller shaft 52a and guides the movement of the work table T. The width of the roller body 52b may be appropriately designed according to the load applied by the rotary tool 30.

  The control unit 60 is mainly composed of a robot control unit 61, a tool rotation control unit 62, a pressurization control unit 63, and a main control unit 64. The control unit 60 is configured separately from the apparatus main body E.

  The robot control unit 61 controls the movement of the work table T according to a command from the main control unit 64, and therefore, a hydraulic system that drives the joints 16 a, 16 b and 16 c of the multi-joint robot 10 and the turntable 11 ( Control of the hydraulic pressure (not shown) is performed.

  The tool rotation control unit 62 sets rotation conditions such as a rotation speed and a rotation direction of the servo motor in the rotation driving unit 42 according to a command from the main control unit 64. This rotation condition is set according to the feed rate of the probe 32, the material of the material to be joined W2, the thickness, and the like. Incidentally, the rotation of the servo motor by the tool rotation control unit 62 is performed via an inverter or the like (not shown).

  The pressurization control unit 63 sets rotation conditions such as the rotation speed and the rotation direction of the servo motor 41 a of the pressurization drive unit 41 according to a command from the main control unit 64. This rotation condition is set according to the amount of pressing of the probe 32 into the workpiece W2, the speed at which the probe 32 approaches or separates from the workpiece W2, and the like. Incidentally, the rotation of the servo motor 41a by the pressurization control unit 63 is performed through an inverter or the like (not shown).

  When the friction stir welding apparatus 1 is started, the main control unit 64 rotates the tool so that the servo motors of the rotation driving unit 42 and the pressure driving unit 41 rotate at a predetermined timing at a predetermined timing. A command signal is output to the control unit 62 and the pressurization control unit 63. Further, the main control unit 64 moves the rotary tool 30 relative to the workpieces W1 and W2 along a predetermined joining line L1 (see FIG. 4), in other words, the work table T is predetermined. A command signal is output to the robot controller 61 so as to achieve the following movement.

[Materials W1 and W2]
Next, the workpieces W1 and W2 that are workpieces will be described. For example, the materials W1 and W2 are members each made of an aluminum alloy. The material to be joined W1 is a member having a trapezoidal cross section and a long shape, and the material to be joined W2 is a thin plate member that is pressed into a shape that covers the upper surface of the material to be joined W1. These materials to be joined W1 and W2 are set (fixed) on the work table T in a state of being overlapped, and are joined by the apparatus main body E.

[Operation of friction stir welding equipment]
Next, the operation of the friction stir welding apparatus 1 will be described with reference to the drawings as appropriate. In the drawings to be referred to, FIG. 3 is a front view of the friction stir welding apparatus, (a) shows the friction stir welding apparatus immediately after the start of the joining operation, and (b) shows the friction stir welding apparatus during the joining operation. . FIG. 4 is an enlarged perspective view of a main part of the friction stir welding apparatus during the joining operation. Hereinafter, the case where the materials W1 and W2 are joined along the joining line L1 shown in FIG. 4 will be described. In the controller 60, the articulated robot 10 is taught in advance based on the shapes of the workpieces W1 and W2 so that the work table T moves in a predetermined manner.

  First, the articulated robot 10 (see FIG. 1) is operated to move the work table T. Specifically, as shown in FIG. 3A, the work table T is positioned so that the workpieces W1 and W2 set on the work table T are sandwiched between the rotary tool 30 and the roller member 50. To do. Then, the roller body 52 b of the roller member 50 is brought into contact with the lower surface side of the work table T. At this time, the roller body 52b is aligned so as to rotate in the joining direction.

  Then, the pressure driving unit 41 is driven while rotating the rotary tool 30 by driving the rotation driving unit 42. As a result, as shown in FIG. 3A, the rotary tool 30 descends while rotating, and the workpieces W <b> 1 and W <b> 2 are pressed by the probe 32. The workpieces W1 and W2 are softened by frictional heat generated by the rotation of the rotary tool 30, and the probe 32 of the rotary tool 30 is gradually inserted into the workpiece W2 arranged on the upper side, and the workpiece W1 is joined. (See FIG. 4). At this time, the work table T is supported by the roller member 50 arranged on the lower side thereof. Thus, by being supported by the roller member 50, a sufficient reaction force from the lower side can be obtained. The friction stir welding apparatus 1 is configured such that the reaction force is adjusted by the pressure drive unit 41 even if the load of the rotary tool 30 on the surfaces of the materials W1 and W2 increases.

  Then, as shown in FIG. 3B, the work table T is moved in a state where the probe 32 of the rotary tool 30 is inserted into the workpiece W2. Specifically, the articulated robot 10 to which the work table T is attached is operated so that the probe 32 moves relative to the joining line L1 (see FIG. 4). At this time, the inclination of the work table T is adjusted via the articulated robot 10 so that the contact portions of the materials W1 and W2 can always receive a vertical load. Further, the vertical movement amount of the rotary tool 30 is also adjusted via the pressure drive unit 41 so that the insertion amount of the probe 32 with respect to the material to be bonded W2 is kept constant.

  Thus, the probe 32 moves relative to the work table T while rotating, so that the vicinity of the contact parts of the materials W1 and W2 fixed to the work table T is plastically fluidized by frictional heat. Joined along the joining line L1. Note that the pressure applied by the rotary tool 30 to the workpieces W1 and W2 is, for example, a reaction force acting on the rotary tool 30 is detected by a pressure sensor, and the servo motor 41a is controlled based on the detected value.

According to the above, the following effects can be obtained in the present embodiment.
In the friction stir welding apparatus 1 according to the present embodiment, the work table T is moved by the articulated robot 10 so that the rotary tool 30 is along the joining line L1 of the workpieces W1 and W2. As described above, since the work table T is configured to be movable by the articulated robot 10, the two workpieces W1 and W2 can be joined along the predetermined (programmed) joining line L1. it can.

  In addition, the work table T is configured to be movable by being gripped by the articulated robot 10, and the reaction force from the rotary tool 30 is received by the holding device 20 instead of the articulated robot. The holding device 20 can sufficiently withstand the reaction force.

  In addition, since the work table T is movable in any direction with respect to the holding device 20, the friction stir welding apparatus 1 can be moved in the three-dimensional direction without resetting the directions of the workpieces W1 and W2. Any joining direction (two or more joining directions) can be easily handled. Thereby, the efficiency at the time of a small quantity production can be improved.

  Although the friction stir welding apparatus 1 according to the present embodiment has been described above, the present invention is not limited to the above-described embodiment, and can be implemented in various forms.

FIG. 5 is a diagram of an apparatus main body according to a modification.
In the above embodiment, the rotation shaft member 51 of the roller member 50 is provided on the same axis line of the rotation axis of the rotary tool 30 (see FIG. 2), but the tool center line A1 of the rotation tool 30 and the roller center line of the caster roller 52 A2 may be offset. Specifically, in the roller holder 51c of the rotating shaft member 51, the roller shaft 52a may be held inside the holding device 20 as compared with the above embodiment. According to this, the roller member 50 can always follow the advancing direction. Thereby, it is possible to perform bonding with high quality even in a complicated shape.

  In the embodiment, the materials W1 and W2 to be joined are made of the same type of aluminum alloy. However, the friction stir welding according to the present embodiment can be used when joining the same material other than the aluminum alloy or different materials. The device 1 can be applied.

  Although the said embodiment demonstrated the case where the to-be-joined materials W1 and W2 were piled up and joined, the friction stir welding apparatus 1 which concerns on this embodiment is applied also when joining the end surfaces of a to-be-joined material. be able to.

  In the above-described embodiment, the roller member 50 that supports the roller main body 52b, which is a rotating body, is used. However, as shown in FIG. 6, a ball bearing type roller member 53 can also be used.

FIG. 1 is a perspective view of a friction stir welding apparatus according to the present embodiment. It is a figure of the apparatus main body and control part which concern on this embodiment. It is a front view of a friction stir welding apparatus, (a) is a friction stir welding apparatus immediately after the start of joining work, (b) is a figure which shows the friction stir welding apparatus in joining work. It is a principal part expansion perspective view of the friction stir welding apparatus in joining operation | work. It is a figure of the apparatus main body which concerns on a modification. It is a figure of the roller member which concerns on a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Friction stir welding apparatus W1 To-be-joined material W2 To-be-joined material 10 Articulated robot 11 Turntable 12 1st arm 13 2nd arm 14 3rd arm 15 Base 20 Holding device 30 Rotating tool 31 Trunk part 32 Probe 40 Drive part 50 Roller member 60 Control unit 61 Robot control unit 62 Tool rotation control unit 63 Pressurization control unit 64 Main control unit E Device body T Work base

Claims (2)

A rotating tool having a probe at the tip;
A holding device for holding the rotating tool;
A roller fixed to the holding device so as to face the rotating tool;
Two workpieces to be joined are fixed, and a work table disposed between the rotating tool and the roller;
A friction stir welding apparatus comprising:
The work table is attached to an articulated robot and configured to be movable independently of the holding device. A rotary tool having a probe at the tip, a holding device that holds the rotary tool, a roller that is fixed to the holding device so as to face the rotary tool, and a rotary tool that is disposed between the rotary tool and the roller A friction stir welding method for joining two workpieces using a friction stir welding apparatus equipped with a work table,
An arranging step of arranging the work table to which the two materials to be joined are fixed between the rotating tool and the holding device;
An insertion step of pressing and inserting the rotating tool while rotating the rotating tool with respect to the material to be joined, with the lower surface of the work table supported by the roller,
A flow step of plastically flowing around the rotary tool in the material to be joined by frictional heat generated by rotation of the rotary tool;
A joining step of joining the two materials to be joined by moving the work table by an articulated robot so that the rotating tool follows a joining line of the materials to be joined;
A friction stir welding method comprising:

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