JP7273705B2 - Distance measuring device, friction stir welding device, and friction stir welding method - Google Patents

Description

TECHNICAL FIELD Embodiments of the present invention relate to a distance measuring device, a friction stir welding device, and a friction stir welding method.

In friction stir welding, it is important to control the pushing amount of the shoulder surface of the welding tool into the workpiece. In particular, the surface height of long workpieces fluctuates greatly, so the surface shape of the workpiece along the bonding line is measured before bonding, and the height of the tool is changed during bonding. Therefore, it may take a long time from setting to joining.
Methods for controlling the pushing amount of the shoulder surface of the welding tool for workpieces with uneven surface height include, for example, a method of measuring the workpiece height using a laser beam, and detecting torque fluctuations of the motor that rotates the welding tool. A method of controlling the height of the welding tool so that the load falls within a predetermined range, and a method of supporting the work table with a cylinder and controlling the height of the work table so that the load applied to the welding tool is constant. etc. are known.

Japanese Patent No. 3314706 Japanese Patent No. 4199446 Japanese Patent No. 6040352

However, when using a method of measuring the workpiece height using a laser beam in order to control the pushing amount of the shoulder surface of the welding tool for workpieces with uneven surface heights, it is necessary to use a laser beam measuring device. There is a problem that the device and adjustment are complicated or the cost is high. In addition, there is a method of detecting torque fluctuations of the motor that rotates the welding tool and controlling the height of the welding tool so that the load falls within a predetermined range, and a method of supporting the work table with a cylinder so that the load applied to the welding tool is constant. In the method of controlling the height of the work table so as to be , there is a problem that it is difficult to detect the torque fluctuation when using a small-diameter welding tool.
Embodiments of the present invention provide a distance measuring device, a friction stir welding device, and a friction stir welding method that are capable of performing high-quality welding even on workpieces with large variations in surface height.

According to the embodiment of the present invention, the distance measuring device includes: a contact portion that contacts a shoulder surface of a welding tool for friction stir welding; a detector for detecting the position of the tip in the first direction; and outputting data on the position of the tip in the first direction detected by the detector. and an output unit for calculating the position of the tip with respect to the contact portion from the position data output from the output unit, and calculating the shoulder surface of the welding tool and the work piece. and a controller for calculating the distance to the surface.

1 is a schematic diagram of a friction stir welding apparatus according to an embodiment of the present invention; FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the friction stir welding method which concerns on embodiment of this invention. FIG. 4 is a schematic diagram showing a method of measuring the distance between the shoulder surface of the welding tool and the surface of the workpiece using the distance measuring mechanism according to the embodiment of the present invention; BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the friction stir welding method which concerns on embodiment of this invention. FIG. 4 is a schematic diagram of another example of the distance measuring mechanism according to the embodiment of the present invention;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each figure, the same elements are denoted by the same reference numerals, and detailed description thereof will be omitted as appropriate. The drawings are schematic, and the relationship between the thickness and width of each portion, the size ratio between portions, and the like are not necessarily the same as the actual ones. Also, even when the same parts are shown, the dimensions and ratios may be different depending on the drawing.

FIG. 1 is a schematic diagram of a friction stir welding apparatus 50 according to an embodiment of the present invention.

A friction stir welding apparatus 50 has a welding tool 10 and a distance measuring device 40 . The distance measuring device 40 has a distance measuring mechanism 20 and a control section 30 .

The joining tool 10 has, for example, a cylindrical shank 11 and a probe pin 12 . A shoulder surface 11 a is formed at one axial end of the shank 11 . A probe pin 12 projecting axially from the shank 11 is provided at the center of the shoulder surface 11a. At least the probe pin 12 and the shoulder surface 11a are made of a material harder than the workpiece to be joined.

A welding tool 10 is held in a tool holder 15 . The tool holder 15 is connected to a rotating mechanism, and the welding tool 10 is rotationally driven around the central axis of the shank 11, for example.

The distance measuring mechanism 20 has a main body 21 , a movable portion 24 , a tip portion 25 , detectors 26 and 27 and an output unit 29 . The body 21 has a contact portion 22 that contacts the shoulder surface 11 a of the welding tool 10 . The main body 21 is fixed to the welding tool 10 with its contact portion 22 in contact with the shoulder surface 11 a of the welding tool 10 .

The movable portion 24 is connected to the main body 21 via the connecting portion 23 . Due to the expansion and contraction of the connecting part 23 , the movable part 24 is movable in the axial direction of the shank 11 with respect to the main body 21 fixed to the welding tool 10 . The connecting part 23 is, for example, a spring or an electric actuator.

Main body 21 and movable portion 24 are provided with detectors 26 and 27, respectively. Detectors 26 and 27 detect the Z position of the movable portion 24 with respect to the main body 21 . Here, the Z position represents the position of the tip portion 25 of the movable portion 24 in the first direction connecting the surface of the workpiece and the shoulder surface 11a of the welding tool 10 . The detectors 26, 27 are, for example, non-contact position sensors. The distance measuring mechanism 20 also includes an output unit 29 that outputs Z position data detected by the detectors 26 and 27 to the control section 30 .

A distal end portion 25 is provided at the distal end of the movable portion 24 . The tip portion 25 is movable together with the movable portion 24 in the first direction connecting the surface of the work and the shoulder surface 11a while being in contact with the surface of the work. The tip 25 is a rotating body, more specifically a sphere.

The control section 30 is electrically connected to the distance measuring mechanism 20 . Based on the Z position data of the tip 25 output from the output unit 29 of the distance measuring mechanism 20, the controller 30 calculates the position of the tip 25 with respect to the contact part 22, and determines the position of the shoulder surface 11a of the welding tool 10. , and a distance calculation unit 31 for calculating the distance between the surface of the workpiece. The control section 30 has a function of instructing the output unit 29 of the distance measuring mechanism 20 to output Z position data for each arbitrary moving distance of the welding tool 10 . The control unit 30 outputs the X coordinate (coordinate in the second direction that intersects the first direction) and the Y coordinate (coordinate in the third direction that intersects the first direction) on the distance measuring mechanism 20 and the distance calculation unit 31. In order to associate the distance between the shoulder surface 11a to be welded and the surface of the workpiece so that the shoulder surface 11a of the welding tool 10 is pushed into the workpiece at a preset depth in the range from the welding start point to the welding end point. It has a calculation unit 32 for calculating the motion trajectory of the joining tool 10 of. The control section 30 has an operation program creation unit 33 that creates an operation program for the friction stir welding apparatus 50 that realizes the operation trajectory.

Next, a friction stir welding method using the friction stir welding apparatus 50 will be described.

As shown in FIG. 2, for example, two plate-shaped works 100b and 100c (hereinafter sometimes referred to simply as reference numeral 100 without distinction) to be joined are butted side to side, and the works 100b and 100c are placed on the stage. to support. In FIG. 2, two directions parallel to the surface of the workpiece 100 and orthogonal to each other are defined as X direction and Y direction. A direction orthogonal to the X direction and the Y direction (the thickness direction of the workpiece 100) is defined as the Z direction. A first direction connecting the surface of the workpiece 100 and the shoulder surface 11a of the welding tool 10 corresponds to the Z direction.

The joining tool 10 is inserted into the surfaces of the butted portions of the two works 100b and 100c while being rotated at high speed. The probe pin 12 is completely inserted into the workpiece 100, and the shoulder surface 11a is pushed into the surface of the workpiece 100 by a predetermined amount. Then, the rotating welding tool 10 is moved along the butted portion (welding line L) of the workpiece 100, and the frictional heat generated between the welding tool 10 and the workpiece 100 and the stirring of the material are utilized. , joins two works 100b and 100c. At the joint 200 of the two works 100b and 100c, the abutting surfaces disappear.

The welding tool 10 may be moved relative to the workpiece 100 along the welding line L. The welding tool 10 may be moved with respect to the stationary workpiece 100, or may Alternatively, the work 100 may be moved by pressing the Alternatively, the welding tool 10 and the workpiece 100 may be moved in opposite directions.

Here, especially in the case of long workpieces having a long area to be welded, which tend to cause undulations and height variations on the surface, it is important to control the amount of pressing of the shoulder surface 11a of the welding tool 10 into the workpiece. . If the shoulder surface 11a is pressed into the work surface insufficiently, a defective joint is caused due to insufficient frictional heat.

Therefore, according to the present embodiment, the distance between the workpiece surface and the shoulder surface 11a at the joining target site is measured using the distance measuring device 40 described above before joining.

As shown in FIG. 3, a measuring mechanism 20 is attached to the welding tool 10 . The abutting portion 22 formed on the main body 21 of the measuring mechanism 20 is brought into contact with the shoulder surface 11 a of the welding tool 10 .

After mounting the measuring mechanism 20 on the welding tool 10 , the tip 25 of the measuring mechanism 20 is brought into contact with the welding start point x1 on the surface 100 a of the work 100 . Then, the tip portion 25 is brought into contact with the surface 100a of the workpiece 100, and the height (position in the Z direction) of the welding tool 10 is kept constant on the device, and the welding tool with the measuring mechanism 20 is attached. 10 is moved substantially horizontally from the joining start point x1 to the joining end point x2 of the work 100 along the joining target portion (joining line) of the work 100 . Note that the welding tool 10 and the distance measuring device 40 are not rotated.

As the welding tool 10 moves, the spherical tip portion 25 moves while rolling on the surface 100a of the workpiece 100 . The connecting portion 23 expands and contracts according to the change in the distance between the surface 100a of the workpiece 100 and the shoulder surface 11a of the welding tool 10, and the movable portion 24 connects the surface 100a of the workpiece 100 and the shoulder surface 11a in the first direction. move to For example, the movable part 24 moves up and down.

During the movement of the welding tool 10 from the welding start point x1 to the welding end point x2, the control section 30 shown in FIG. This detection may be performed continuously from the welding start point x1 to the welding end point x2, or may be detected and output for each preset movement distance of the welding tool 10 . When detection is performed for each movement distance of the welding tool 10, the control unit 30 determines the x-coordinate and y-coordinate of the position of the welding tool 10 to be detected. When the welding tool 10 moves to the measurement position, the controller 30 detects the position of the distal end portion 25 with respect to the contact portion 22 and acquires it as data. Based on this detection result, the distance between the shoulder surface 11a and the surface 100a of the workpiece 100 is calculated in association with the position (x coordinate, y coordinate) of the part to be welded between the welding start point x1 and the welding end point x2. .

Further, the control unit 30 creates motion trajectory data of the welding tool 10 from the distance between the shoulder surface 11a and the surface 100a of the workpiece 100 . For example, the motion trajectory data associates the position (x coordinate, y coordinate) of the part to be welded between the welding start point x1 and the welding end point x2 with the height (z coordinate) of the welding tool 10. be.

The controller 30 creates an operation program for the welding tool 10 based on the operation trajectory data. Then, the measuring mechanism 20 is removed from the welding tool 10, and the workpiece 100 is friction stir welded by the welding tool 10 according to the operation program.

That is, as shown in FIG. 4, the probe pin 12 of the welding tool 10 is inserted into the part to be welded of the workpiece 100, and the shoulder surface 11a is pushed into the surface of the part to be welded. Move from the start point x1 to the joining end point x2.

Based on the movement trajectory data, the position of the welding tool 10 in the direction (Z direction) orthogonal to the moving direction along the welding target part is controlled, and the pushing amount of the shoulder surface 11a to the welding target part is controlled within a predetermined range. be done.

For example, when the outer diameter of the shoulder surface 11a is 10 mm and the length of the probe pin 12 is 3 mm, the pushing amount of the shoulder surface 11a into the joining target site is controlled within a range of 0.2 mm plus or minus 0.05 mm. . If the work to be joined is a thin plate, it is necessary to control the pushing amount with higher precision. For example, when the thickness of the workpiece is 0.5 mm, the outer diameter of the shoulder surface 11a is 3 mm, the length of the probe pin 12 is 0.4 mm, and the amount of pressing of the shoulder surface 11a into the joining target site is 0.05 mm. Control within the range of plus or minus 0.01 mm.

As described above, according to the embodiment, it is possible to appropriately control the pressing amount of the shoulder surface 11a into the joining target site even for the work 100 having uneven surface heights, and perform high-quality joining.
For example, without using an expensive laser light measuring device such as a method of measuring the height of a workpiece using laser light, according to the embodiment, a low-cost and simple contact-type measuring mechanism can be used to measure the shoulder surface 11a and the shoulder surface 11a. The distance to the surface 100a of the workpiece 100 can be measured in a short time.

In addition, in order to control the pushing amount of the shoulder surface of the welding tool for workpieces with uneven surface height, the torque fluctuation of the motor that rotates the welding tool is detected, and the welding tool is adjusted so that the load falls within a predetermined range. Welds workpieces with uneven surface heights by controlling the height, or by supporting the work table with a cylinder and controlling the height of the work table so that the load applied to the welding tool is constant. When controlling the pushing amount of the shoulder surface of the tool, it becomes difficult to detect load fluctuations when using a welding tool with a small diameter. In contrast, according to the embodiment, high-quality friction stir welding can be performed even when using a small-diameter welding tool.

The part to be joined (the butted part of two works) is not limited to a straight line, and the joint surface may be a curved surface. Therefore, the movement trajectory of the welding tool 10 moving along the parts to be welded is not limited to a straight line, and may be a curved line.

Further, the tip portion 25 that moves on the surface 100a of the workpiece 100 while being in contact with the surface 100a is not limited to a spherical body, and may be a rotating body such as a roller. Further, the tip portion 25 may be configured not to rotate, but in this case, friction between the tip portion 25 and the surface 100a of the work 100 may bend the surface 100a of the work 100 .

FIG. 1 shows an example in which the distance measuring mechanism 20 is arranged coaxially with the welding tool 10, but as shown in FIG. Even if the movable portion 124 to which the distal end portion 25 is connected is offset from the welding tool 10 and mounted on the welding tool 10, the same friction stir welding as in the above-described embodiment can be performed. The movable part 124 is connected to the main body 121 fixed to the welding tool 10 by a connecting part 123 such as a spring or an electric actuator, and is movable in the axial direction of the shank 11 .

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 10... Joining tool 11a... Shoulder surface 12... Probe pin 20... Distance measuring mechanism 22... Contact part 24... Movable part 25... Tip part 30... Control part 40... Distance measuring device 50... Friction stir welding device, 100, 100b, 100c... work

Claims (7)

a contact portion that contacts a shoulder surface of a welding tool for friction stir welding; a tip portion that is movable in a first direction connecting the surface of the work and the shoulder surface while in contact with the surface of the work; a measuring mechanism comprising: a detector for detecting the position of the tip in the first direction; and an output unit for outputting data on the position of the tip in the first direction detected by the detector;
A control unit that calculates the position of the tip with respect to the contact part from the position data output from the output unit, and calculates the distance between the shoulder surface of the welding tool and the surface of the workpiece. and,
distance measuring device with 2. The distance measuring device according to claim 1, wherein said tip is a rotating body. 3. The distance measuring device according to claim 2, wherein said tip is spherical. The control unit
Calculation for calculating the motion trajectory of the welding tool from the position data output from the output unit of the measuring mechanism and the coordinates of the second and third directions intersecting the first direction on the measuring mechanism. a unit;
a motion program creation unit that creates a motion program for the welding tool based on the motion trajectory;
The distance measuring device according to any one of claims 1 to 3, comprising: A distance measuring device according to any one of claims 1 to 4;
the bonding tool;
Friction stir welding equipment. A welding tool having a shoulder surface and a probe pin is provided with a measuring mechanism having a distal end movable in a first direction connecting the surface of the workpiece and the shoulder surface, and a contact portion of the measuring mechanism is connected to the shoulder of the welding tool. a step of mounting by abutting against a surface;
a step of contacting the tip with a joining start point on the surface of the work;
With the tip part in contact with the surface of the workpiece, the welding tool equipped with the measuring mechanism is moved substantially horizontally from the welding start point along the welding target part of the workpiece to the welding end point of the workpiece. a step of causing
During the movement of the welding tool from the welding start point to the welding end point, the position of the tip portion with respect to the contact portion is detected, and the position of the shoulder surface and the surface of the workpiece at the welding target portion of the workpiece is detected. calculating the distance between
The shoulder surface of the welding tool is pushed into the workpiece at a preset depth in the range from the welding start point to the welding end point from the distance between the shoulder surface and the surface of the workpiece. creating motion trajectory data for the joining tool;
creating an operation program for the friction stir welding apparatus based on the operation trajectory data;
removing the measuring mechanism from the welding tool and moving the welding tool from the welding start point to the welding end point while rotating the welding tool based on the operation program;
A friction stir welding method comprising: Based on the motion trajectory data, the position of the welding tool in the direction perpendicular to the direction of movement along the part to be welded is controlled, and the amount of pressing of the shoulder surface into the part to be welded is controlled within a predetermined range. The friction stir welding method according to claim 6.

Images