JP2006068800A - Friction stir spot joining method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a friction stir spot joining method where, at the time of the relative movement of a joining gun and the works to be joined, a pin is pushed into the works to be joined and is moved to a joining point at an early stage, further, even after the completion of the joining, the pin is pulled out from the works to be joined simultaneously with the relative movement of the joining gun and the works to be joined, thus the reduction of joining time and the secure joining of the works to be joined are possible on the whole. <P>SOLUTION: Before a joining tool 8 approaches the joining part in the works to be joined, a motor for movement is driven, and the joining tool is moved (2) toward the works W1, W2 to be joined, is press-fitted from the upstream side of a joining point to the works to be joined and is made to reach the joining point. In the joining point (3), the works to be joined are joined by a pin 7. Further, a robot is operated and the motor for movement is reversed, and, as the joining tool is separated from the joining point of the works to be joined, it is gradually pulled-out (4) from the works to be joined on the downstream side of the joining point. Then, the rotation of the motor for movement is stopped at a position where the joining tool is perfectly separated from the works to be joined. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention includes a joining tool having a pin at the tip, a stirring motor for rotating the joining tool, and a moving motor for moving the joining tool pin into and out of the member to be joined. It consists of a joining gun and a robot that moves the joining tool and the member to be joined relative to each other, and presses the pin of the joining tool into the member to be joined and softens the object to be joined by frictional heat generated by the rotation of the pin. The present invention relates to a friction stir spot welding method in which stirring and spot welding are performed.

  Conventionally, a joining gun having a joining tool having a pin at the tip, a stirring motor for rotating the joining tool, and a moving motor for moving the joining tool pin into and out of the member to be joined. And a robot that relatively moves the joining tool and the member to be joined. The pins of the joining tool are press-fitted into the member to be joined, and the object to be joined is softened and agitated by frictional heat generated by the rotation of the pins. This is a friction stir spot welding method in which spot welding is performed, and the robot guides the pin of the welding tool directly above the joining point of the member to be joined, stops the robot at this point, and then lowers the welding tool. After pressurizing the members to be joined and completing the joining by friction stirring with pins, the joining tool is pulled out in the axial direction, and then the joining gun is moved to the next joining point by the robot. There is a spot bonding method For example, see Patent Document 1.).

Japanese Patent No. 3429475.

  By the way, in the above conventional technique, at the time of joining the members to be joined, the robot guides the pins of the joining tool to the position just above the joining point of the members to be joined, where the robot once stops the movement of the joining gun, After the series of operations of lowering, pushing, stirring, and pulling out the welding tool from the part is completed, the movement of the welding gun by the robot is started again from the part immediately above, so that it takes time to join the members to be joined. In particular, in a member to be joined such as an automobile part, which generally has a large number of joining points, the total time required for joining becomes long, which greatly affects the number of automobile body assembly lines produced. There is.

  The present invention has been made in view of such problems of the prior art, and the object of the present invention is to move the moving motor early when the robot moves the welding gun and the member to be joined. Driven, pushes the pin into the member to be joined, moves it to the joining point while stirring, and even after the joining of the member to be joined is completed, the robot moves the joining gun and the member to be joined together with the relative movement between the joining gun and the member to be joined. An object of the present invention is to provide a friction stir spot welding method capable of shortening the overall joining time and reliably joining the members to be joined by pulling them out from the members to be joined.

  In order to achieve the above object, the friction stir spot welding method according to the present invention operates the robot to drive the moving motor before the welding tool approaches the joining part of the member to be joined. The tool is moved toward the member to be joined, and sequentially press-fitted into the member to be joined from the upstream side of the joining point to reach the joining point, the joined member is joined by the pin at the joining point, and the robot is further operated. At the same time, the moving motor is reversed, and the joining tool is sequentially pulled out from the joined member at the downstream side of the joining point while separating the joining tool from the joining point of the joined member. The rotation of the motor for movement is stopped at a position completely separated from the joining member.

  Further, the joining tool is moved by the robot, and the joining tool and the member to be joined are moved relative to each other.

  Further, the member to be joined is moved by the robot, and the joining tool and the member to be joined are moved relative to each other.

  Further, the present invention is characterized in that the pin is moved in a state of being tilted rearward and upward with respect to the moving direction of the bonding tool when the bonding tool and the member to be bonded are moved by the robot. .

  In the friction stir spot welding method according to the present invention, the robot is operated to drive the moving motor before the joining tool approaches the joining portion of the member to be joined. The joint member is sequentially pressed into the joining member from the upstream side of the joining point to reach the joining point, and the joining member is joined by the pin at the joining point, and the robot is operated and the moving motor is reversed. The welding tool is sequentially pulled out of the member to be joined at the downstream side of the joining point while separating the joining tool from the joining point of the member to be joined, and the joining tool is completely detached from the member to be joined. Since the rotation of the moving motor is stopped, a relatively wide agitation zone is formed from the upstream side to the downstream side of the joining point of the members to be joined. Whether relative movement is performed When the welding gun is moved by the robot, the movement motor is already driven, the pin is pushed into the member to be joined, moved to the joining point while stirring, and the joining gun is moved by the robot even after the joining of the member to be joined is completed. At the same time, by pulling out the pin by the moving motor from the member to be joined, the friction stir spot joining method is possible which can shorten the joining time as a whole and reliably join the member to be joined.

  Also, if the pins are moved rearward and upward relative to the direction of movement of the welding tool when the welding tool and the workpiece are moved relative to each other by the robot, the member to be joined is more reliable. This is a friction stir spot welding method capable of smooth joining.

  The friction stir spot welding method is defined as “a joining tool having a pin at the tip, a stirring motor for rotating the joining tool, and a moving motor for bringing the joining tool pin into and out of the member to be joined. And a robot that relatively moves the joining tool and the member to be joined, and presses the pin of the joining tool into the member to be joined, and is joined by frictional heat generated by the rotation of the pin. In friction stir spot welding in which an object is softened and stirred to perform spot welding, the robot is operated to drive the moving motor before the welding tool approaches the joining part of the member to be joined. -Move the screw toward the member to be joined, press-fit sequentially into the member to be joined from the upstream side of the joining point, reach the joining point, join the joined member with the pin at the joining point, and further operate the robot Reverse the motor for movement The welding tool is sequentially withdrawn from the member to be joined at the downstream side of the joining point while separating the joining tool from the joining point of the member to be joined, and the joining tool is completely detached from the member to be joined. The configuration is such that the rotation of the motor for movement is stopped.

  In some cases, the pins are moved rearward and upward with respect to the direction of movement of the joining tool when the joining tool and the member to be joined are moved by the robot.

  FIG. 1 is a schematic configuration diagram of a welding apparatus suitable for carrying out the friction stir spot welding method according to the present invention, and FIG. 2 is a schematic explanatory diagram showing the movement of the welding tool relative to the members to be joined.

  In FIG. 1, reference numeral 1 denotes a gun bracket connected to a wrist 2 of a robot. A transmission box 3 is provided at the base of the gun bracket 1, and a joining tool (to be described later) is provided on one side of the transmission box 3. A moving motor 4 for moving the pins in and out of the member to be joined is arranged, and a C-shaped fixing arm 5 is extended on the other side.

  A stirring motor 6 is disposed in the transmission box 3, and a joining tool 8 having a pin 7 at the tip is connected to the stirring motor 6.

  A backing material 9 is attached to the front end of the fixed arm 5 so as to face the pin 7, and the backing material 9 is sequentially positioned near the joining point of the members W1 and W2 to be joined by a robot. It is like that.

  Reference numeral 10 denotes a ball nut fixed to the rear end side of the agitating motor 6, and an LM guide 12 is provided on one side of the bracket 11 that holds the ball nut 10. A guide rail 13 is provided in the transmission box 3 in the axial direction of the agitating motor 6 so as to be very close to the agitating motor 6. The LM guide 12 is movable along the guide rail 13, and the bracket 11 of the LM guide 12 is fixed to the rear end side of the stirring motor 6.

  Then, the wrist 2 of the robot is taught so as to move the joining gun in accordance with the positions of the joining points of the fixed members W1 and W2 that are stationary. The stirring motor 6 for rotating the joining tool 8 having the pin 7 at the tip is always driven. Further, the moving motor 4 for moving the pin 7 of the joining tool 8 into and out of the joined members W1 and W2 is stopped when the pin 7 is opened, and is upstream of the joining point of the joined members W1 and W2. Driven at a predetermined position on the side, the joint tool 8 is lowered, and when the joint is made at the joint point, it is reversed and the joint tool 8 is raised on the downstream side of the joint point, and the pin 7 is opened. It will be stopped when it returns to. The predetermined position on the upstream side is arbitrarily determined by the moving speed of the welding gun by the robot and the lowering speed of the welding tool 8 by the moving motor 4.

  The progress of the relative movement of the welding tool relative to the member to be joined when the stationary members W1 and W2 are fixed is as shown in FIG. Here, the arrow (1) is the open area of the pin 7, the arrow (2) is the descending area of the pin 7, (3) is the joining area which is the joining point, and the arrow (4) is the ascending area of the pin 7. (4) is connected to the next arrow (1).

  In FIG. 2, first, the pin 7 of the joining tool 8 is rotated by the stirring motor, the moving motor is stopped, the pin 7 is in the open state, and the pin 7 is moved to the arrow by the robot. Move along (1) while maintaining the open state.

  When the welding tool 8 approaches the members to be joined W1 and W2 and the moving motor is driven at a predetermined upstream side from the joining region, the pin 7 enters the descending region indicated by the arrow (2) and descends while the pin 7 Comes into contact with the surface of the member W1 and continues to descend. When the pin 7 comes into contact with the surface of the member W1 to be joined, the stirring of the members W1 and W2 by the pin 7 starts.

  When the pin 7 is pushed to a predetermined depth with respect to the member W1 to be joined, the driving of the moving motor is stopped and the movement of the joining gun by the robot is stopped, so that the pin 7 is covered in the joining area of (3). The joining operation of the joining members W1 and W2 is performed.

  When the joining of the members to be joined W1 and W2 is finished, the drive motor is re-driven on the downstream side of the joining area and the moving direction of the motor is reversed and the movement of the joining gun by the robot is resumed. 7 enters the ascending region of the arrow (4), and the pin 7 is pulled out from the surface of the joined member W1 while moving up, and the ascending / descending continues. The members to be joined W1 and W2 are agitated by the pin 7 until the pin 7 escapes from the surface of the member to be joined W1, and when the pin 7 rises to the open state, the moving mode is reached. -Stop driving.

  Since the movement of the welding tool 8 by the robot is continuously performed, the pin 7 of the welding tool 8 moves from the rising area of the arrow (4) to the opening area of the next arrow (1). Then, the joining gun is moved toward the next joining point of the members to be joined W1, W2.

  As described above, in the joining method according to the present invention, the robot is operated to drive the moving motor 4 before the joining tool 8 approaches the joining portion of the joined members W1 and W2, thereby joining the joining point. Are sequentially press-fitted into the members to be joined W1 and W2 so as to reach the joining point, the members to be joined W1 and W2 are joined by the pins 7 at the joining point, and the robot is operated and the moving motor 4 is moved. The joining tool 8 is sequentially pulled out from the joined members W1 and W2 on the downstream side of the joining point while being reversely moved to separate the joining tool 8 from the joining points of the joined members W1 and W2. Since the rotation of the motor 4 for movement is stopped at a position where it is completely detached from the members W1 and W2, the overall time required for joining is significantly shortened compared to the prior art, and the parts to be joined are also joined. Friction stir spot welding method that enables reliable joining of members

  In the above embodiment, the movement of the bonding gun by the robot is temporarily stopped in the bonding area (3). However, the movement of the bonding gun by the robot is continued in this bonding area (3).

  In this way, even in the joining area (3), by continuing the movement of the joining gun by the robot, the joining area can be given a certain width, and this allows more reliable joining of the members to be joined. This is a friction stir spot welding method.

  FIG. 3 is a schematic configuration diagram of another embodiment of a joining apparatus suitable for carrying out the friction stir spot joining method according to the present invention.

  In this embodiment, the joining gun is a stationary type, and the members W1 and W2 to be joined are moved by a robot. And since the structure of a joining gun is substantially the same as the previous Example, it attaches | subjects the same code | symbol and abbreviate | omits the description.

  In FIG. 3, a bonding gun is fixed to a stand 21 standing on the ground FL. Further, the members W1 and W2 are held on the guides 22 and 23 so as to be movable. The members W1 and W2 are connected to a jig base 24 connected to the wrist 2 of the robot, and move on the guides 22 and 23 with respect to the pins 7 as the robot moves. It is.

  The wrist 2 of the robot is taught to move the members to be joined W1 and W2 so that the positions of the joining points of the members to be joined W1 and W2 that move relative to the stationary joining gun correspond to each other. The stirring motor 6 for rotating the joining tool 8 having the pin 7 at the tip is always driven. Further, the moving motor 4 for moving the pin 7 of the joining tool 8 into and out of the joined members W1 and W2 is stopped when the pin 7 is opened, and is upstream of the joining point of the joined members W1 and W2. Driven at a predetermined position on the side, the joint tool 8 is lowered, and when the joint is made at the joint point, it is reversed and the joint tool 8 is raised on the downstream side of the joint point, and the pin 7 is opened. It will be stopped when it returns to.

  The progress of the relative movement of the joining tool with respect to the member to be joined at the time of joining the members to be joined W1 and W2 to be moved is substantially the same as in the first embodiment.

  Further, the movement of the members to be joined W1 and W2 by the robot may be continued, or the robot may be temporarily stopped in the joining region of the members to be joined W1 and W2.

  In the embodiments described so far, the description will be made on the operation in which the pin 7 is operated in the upright state with respect to the lateral movement direction of the welding tool 8 when the welding tool 8 and the members W1 and W2 are moved relative to each other by the robot. However, as shown in FIG. 4, the pin 7 is moved rearward and upward with respect to the lateral movement direction of the welding tool 8 when the welding tool 8 and the members W1 and W2 are moved relative to each other by the robot. The joining operation may be performed in an inclined state.

  In this case, the stirring operation by the pin 7 is further expanded, and a friction stir spot joining method capable of more reliable joining is obtained.

FIG. 1 is a schematic configuration diagram of a welding apparatus suitable for carrying out the friction stir spot welding method according to the present invention. FIG. 2 is a schematic explanatory view showing the movement of the joining tool relative to the member to be joined. FIG. 3 is a schematic configuration diagram of another embodiment of a joining apparatus suitable for carrying out the friction stir spot joining method according to the present invention. FIG. 4 is a schematic explanatory view of another embodiment showing the movement of the joining tool relative to the member to be joined.

Explanation of symbols

2 Robot wrist 4 Motor for movement 6 Motor for stirring 7 Pin 8 Joining tool W1, W2 Joined member

Claims (4)

A joining gun comprising a joining tool having a pin at the tip, a stirring motor for rotating the joining tool, and a moving motor for moving the joining tool pin to and from the member to be joined; It consists of a robot that moves the joining tool and the member to be joined relative to each other. The pins of the joining tool are press-fitted into the member to be joined, and the object to be joined is softened and agitated by frictional heat generated by the rotation of the pins. In the friction stir spot welding for spot welding, the robot is operated to drive the moving motor before the welding tool approaches the joining part of the workpiece to be joined. The joint member is sequentially press-fitted from the upstream side of the joining point to reach the joining point, and the joining member is joined by the pin at the joining point, and the robot is operated and the moving motor is reversed. The joining tool to be joined Pull out the welding tool sequentially from the joined member at the downstream side of the joining point while separating from the joining point, and stop the rotation of the moving motor at the position where the joining tool is completely detached from the joined member. A friction stir spot welding method characterized by the above. 2. The friction stir spot welding method according to claim 1, wherein the welding tool is moved by the robot to move the welding tool and the member to be joined relative to each other. 2. The friction stir spot welding method according to claim 1, wherein the member to be joined is moved by the robot to move the joining tool and the member to be joined relative to each other. 3. The apparatus according to claim 2, wherein the pin is moved in a state where the pin is inclined rearward and upward with respect to the moving direction of the bonding tool when the bonding tool and the member to be bonded are moved by the robot. 3. The friction stir spot welding method according to 3.

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