JP5641242B2 - Friction stir welded joint diameter measuring method and apparatus, and friction stir weld quality inspection method and apparatus - Google Patents

Description

  The present invention relates to a friction stir welding joint diameter measuring method and apparatus, a friction stir welding quality inspection method, and a friction stir welding quality measurement method for measuring a joint diameter of a joint where two members are joined using a friction stir welding method. It relates to the device.

In recent years, a friction stir welding (FSW) method has been developed as a solid-phase joining method for two members. This is because a joining tool (tool) having a projection (pin) at the tip is made to enter and rotate into the joining target part of two superimposed members to give frictional heat to create a plasticized phase in the material. This is a joining method in which two members are joined at a temperature below the melting point.
For example, friction stir spot welding (spot FSW) using such a friction stir welding method is mainly used for joining aluminum alloy materials. In order to confirm the quality of this joining, the fracture diameter may be measured. However, since the joined product is destroyed in the measurement by fracture, Patent Document 1 that measures the joining region non-destructively (estimates the joining diameter). The described method is proposed.

WO2007 / 116629 (Republished Patent Gazette)

  However, in the above-described prior art, when a pressure contact surface is generated between two bonding members, this pressure contact surface region cannot be distinguished from a diffusion bonding region, and erroneously measured that even a pressure contact surface region that is not diffusion bonded is bonded. There is a problem. This can be confirmed from a comparison between the result of measuring the joint diameter of the two joining members by using the ultrasonic wave and the result of measuring the joint diameter by observing the actual fracture surface of the joint member.

The present invention has been made in view of the above circumstances, and can avoid erroneously measuring the pressure contact area as a diffusion bonding area during nondestructive measurement using ultrasonic waves, and can increase the diffusion bonding diameter with higher accuracy. It is an object of the present invention to provide a method and an apparatus for measuring a joint diameter of a friction stir joint that can be measured.
Moreover, this invention makes it a subject to provide the friction stir welding quality inspection method and apparatus which can test | inspect the quality of a junction part with higher precision.

The said subject is solved by making the structure and measuring apparatus of a friction stir welding quality inspection method and apparatus of a friction stir welding part into the following each aspect.
As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is merely for the purpose of facilitating the understanding of the present invention, and the technical features described in this specification and combinations thereof should not be construed as being limited to those described in the following sections. . In addition, when a plurality of items are described in one section, it is not always necessary to employ the plurality of items together, and it is also possible to take out only a part of the items and employ them.

  Of the following items, (1) is in claim 1, (2) is in claim 2, (3) is in claim 3, (4) is in claim 4, (5) The term corresponds to claim 5, and the term (6) corresponds to claim 6.

(1) A method for measuring a joint diameter of a joint portion in which two overlapped members to be joined are joined by a friction stir spot joining method, wherein an estimated value of the joint diameter is obtained by ultrasonic measurement; A second step of obtaining a distance between a shoulder push-in position of the welding tool during friction stir welding and a back surface of the joined member on the welding tool side, and the estimated value when the distance exceeds a predetermined threshold value. And a third step of measuring the joint diameter as a measured value of the joint diameter.
(2) The distance obtained in the second step is the remaining base thickness in the joint, the distance from the tip end position of the shoulder of the joining tool to the tip end position of the pin, and the joined side opposite to the joining tool side. The method for measuring the joint diameter of the friction stir joint according to item (1), wherein the joint diameter is calculated based on the thickness of the member.
(3) A device for measuring a joint diameter of a joint portion in which two overlapping members to be joined are joined by the friction stir spot joining method, and obtaining an estimated value of the joint diameter by ultrasonic measurement Distance calculating means for obtaining a distance between a shoulder pressing position of the welding tool of the welding tool at the time of friction stir welding and a back surface of the bonded member on the welding tool side, and the estimation when the distance exceeds a predetermined threshold value And a joining diameter determining means having a value as a measured value of the joining diameter.
(4) The distance calculated by the distance calculation means is the remaining base thickness in the joint, the distance from the tip position of the shoulder of the joining tool to the tip position of the pin, and the workpiece to be joined opposite to the joining tool side. The joint diameter measuring device for a friction stir weld according to item (3), which is calculated based on the thickness of the member.
(5) A method for inspecting a joint where two stacked members to be joined are joined by the friction stir spot joining method, and measuring the joint diameter of the friction stir joint according to (1) or (2) A friction stir welding quality inspection method, wherein quality of the joint is inspected based on a measurement result obtained by the method.
(6) An apparatus for inspecting a bonded portion in which two overlapped members to be bonded are bonded by a friction stir spot bonding method, and measuring the bonding diameter of the friction stir bonding portion according to (3) or (4) A friction stir welding quality inspection apparatus comprising: a determination unit that determines whether or not the quality of the joint is good based on a measurement result by the apparatus; and an output unit that outputs a determination result of the determination unit.

According to the invention described in item (1), an appropriate threshold value is set in measuring the joint diameter of the joint portions of the joined members joined by the friction stir spot joining method, and the influence of the pressure contact surface region, Since the above-described bonding diameter is measured while avoiding an erroneous determination that the bonding is performed while it is not bonded, the bonding diameter can be measured with high accuracy.
According to the invention described in item (2), the distance obtained in the second step in the invention of item (1) can be obtained easily and accurately.
According to the invention described in the item (3), an appropriate threshold value is set in measuring the joint diameter of the joint portions of the members to be joined joined by the friction stir spot joining method, and the influence of the pressure contact surface region, Since the above-described bonding diameter is measured while avoiding an erroneous determination that the bonding is performed while it is not bonded, the bonding diameter can be measured with high accuracy.
According to the invention described in the item (4), the distance obtained by the distance calculating means in the invention of the item (3) can be obtained easily and accurately.
According to the invention described in the item (5), since the quality of the joint is inspected based on the result of the joint diameter measurement by the method for measuring the joint diameter of the friction stir joint described in the item (1) or (2), It is possible to provide a friction stir welding quality inspection method capable of non-destructive and high-precision inspection of a joint.
According to the invention described in the item (6), since the quality of the joint is inspected based on the joint diameter measurement result by the joint diameter measuring device of the friction stir joint according to the item (3) or (4), It is possible to provide a friction stir welding quality inspection device capable of inspecting a joint with nondestructive and high accuracy.

It is a block diagram which shows one Embodiment of the joint diameter measuring apparatus of the friction stir welding part by this invention. It is a schematic explanatory drawing of the joining tool used for the friction stir spot joining method and the joining method. It is a figure which shows typically the longitudinal cross-section of the junction part of the upper board and lower board joined by the same joining method. It is a figure for demonstrating the mode of the ultrasonic measurement of a junction part same as the above. It is a figure which shows the image (at the time of a normal measurement) by the measurement result of the junction part of the upper board and lower board joined by the friction stir spot joining method. It is a figure which similarly shows the image (at the time of abnormal measurement) by the measurement result of the junction part of an upper board and a lower board.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol shows the same or an equivalent part between each figure.
FIG. 1 is a block diagram showing an embodiment of a joint diameter measuring apparatus for a friction stir joint to which the method of the present invention is applied.
This friction stir welded joint diameter measuring device is a device that measures the joint diameter of a joint where two stacked members to be joined are joined by the friction stir spot joining method, and is basically an ultrasonic measurement. The apparatus 1 includes a computer program for measuring the joint diameter of the friction stir welded portion (a computer program for executing the method of the present invention; hereinafter abbreviated as a program for measuring the joint diameter) 2.

Here, the ultrasonic measurement apparatus 1 transmits an ultrasonic wave from the surface of the measurement object and receives a reflected wave (echo signal), and the distance from the surface of the measurement object to the reflection position of the ultrasonic wave or the reflection position. This is a known apparatus for ultrasonic measurement capable of measuring the distance between each other nondestructively.
The ultrasonic measurement apparatus 1 includes an ultrasonic measurement apparatus main body 3, an ultrasonic probe 4, ultrasonic transmission / reception means 5, probe movement means 6, probe position detection means 7, various data / parameter input means 8 and output means 9. It is equipped with.

By performing ultrasonic measurement while moving the ultrasonic probe 4 in the linear direction, not only various numerical data (distance data etc.) on the straight line but also an ultrasonic tomographic image output means 9 based on the measurement result. Can be displayed.
Further, if ultrasonic measurement is performed while moving (scanning) the ultrasonic probe 4 in the surface direction, an image of the ultrasonic reflection surface inside the measurement object in a direction along the surface of the measurement object or a predetermined reflected wave A surface image in which the luminance corresponding to the intensity of the reflected wave at each position on the surface of the measurement object, such as a surface image configured with the luminance corresponding to the peak value as the pixel value, can be displayed on the output unit 9.

In the present embodiment, the bonding diameter measurement program 2 is stored in the external storage means 10. Various data, parameters, and the like necessary for the execution of the joint diameter measuring program 2 are also stored in the external storage means 10 along with the joint diameter measuring program 2.
The ultrasonic measurement apparatus main body 3 includes a control / processing unit 11 including a CPU and a memory (ROM, RAM) necessary for ultrasonic measurement.
Numerical data as an ultrasonic measurement result, the above-described image (data), a reflected wave data group constituting the image, and the like are stored in the control / processing unit 11 or the external storage unit 10 or read out arbitrarily after storage. It is also possible to display again on the output means 9 such as a display device.

In the present embodiment, the ultrasonic measurement apparatus main body 3 is configured such that the control / processing unit 11 functions by executing the bonding diameter measurement program 2 stored in the external storage unit 10, and a distance calculation unit. 13 and a joining diameter determining means 14.
Hereinafter, these means 12 to 14 will be described with reference to FIGS.

  As shown in FIG. 2, the friction stir spot welding (spot FSW) method includes two stacked members to be bonded, in this case, two metal plates stacked above and below, for example, an aluminum plate (hereinafter referred to as an upper plate). 21 and the lower plate 22)) with respect to the joining target portion, a joining tool 24 having a pin 23 at the tip is made to enter and rotate from above the upper plate 21, and the upper plate 21 and the lower plate 22 are solid-phase joined. This is a joining method. The pin 23 is inserted deeply into the upper and lower plates 21 and 22, but the shoulder 25 is only slightly pushed into the upper plate 21. The length of the pin 23 (the distance from the tip position of the shoulder 25 to the tip position of the pin 23) L and the shoulder diameter D can be changed according to the thicknesses T1, T2, etc. of the upper and lower plates 21, 22.

FIG. 3 is a diagram schematically showing a longitudinal section of a joint portion of the upper plate 21 and the lower plate 22 joined by the friction stir spot joining method, which is a measurement object in the present embodiment.
In FIG. 3, T1 is the thickness of the upper plate 21, T2 is the thickness of the lower plate 22, D is the shoulder diameter, Δt is the residual base thickness, T3 is the length L of the pin 23 and the residual base thickness Δt. (T3 = L + Δt).
ΔT is the distance between the pushing position of the shoulder 25 of the welding tool 24 and the member to be joined on the welding tool 24 side, that is, the back surface (the lower surface in FIG. 3) of the upper plate 21. It is obtained by subtracting the thickness T2 of the lower plate 22 from T3.
φA is the joint diameter measured by the conventional joint diameter measurement (estimation), and there is a pressure contact surface region PE between the upper and lower plates 21 and 22, and the pressure contact surface region PE is also erroneously measured as a diffusion joint region. Is a diffusion bonding diameter (an erroneous measurement bonding diameter). The range of φA shown in FIG. 3 is an example, and changes depending on the generation range, position, and the like of the pressure contact surface region PE.
φA ′ is a true diffusion bonding diameter (true bonding diameter) that can be found by actual shear failure with a chisel or the like.
φA ″ is a diffusion bonding diameter (invention measurement bonding diameter) measured by the bonding diameter measuring device of the friction stir welding portion according to the present embodiment. The range of φA ″ shown in FIG. 3 is an example.

1 to 3, the joint diameter estimating means 12 is an ultrasonic measurement, and an estimated value of the joint diameter of the joint portion of the upper plate 21 and the lower plate 22 by the friction stir spot joining, that is, a conventional joint diameter measurement. To determine the bonding diameter φA (incorrect measurement bonding diameter).
Further, the distance calculating means 13 calculates a distance ΔT between the pushing position of the shoulder 25 of the welding tool 24 at the time of friction stir welding and the back surface (the lower surface in FIG. 3) of the upper plate 21 which is a member to be joined on the welding tool 24 side. It is a means to seek. In the present embodiment, the distance calculation means 13 subtracts the thickness T2 of the lower plate 22 from the added value T3 (= L + Δt) of the length L of the pin 23 and the remaining base thickness Δt shown in FIG. Looking for. The remaining mother thickness Δt can be easily measured at the time of measuring the bonding diameter by ultrasonic measurement.
Further, the joining diameter determining means 14 determines the estimated value when the distance ΔT exceeds a predetermined threshold, for example, 0.6 (mm) (ΔT> 0.6), This is a means for determining the joint diameter as the measured value φA ″ (measured joint diameter of the present invention) of the joint diameter of the joint portion of the plate 22.

  In the present embodiment, the joint diameter estimating means 12, the distance calculating means 13, and the joint diameter determining means 14 (function) are incorporated in the ultrasonic measuring device main body 3 to execute the joint diameter measurement of the friction stir joint. It is. Various parameters necessary for the execution, in this embodiment, the length L of the pin 23, the thickness T1 of the upper plate 21, the thickness T2 of the lower plate 22, and the residual base thickness Δt are measured by ultrasonic measurement before performing the bonding diameter measurement. Input to the apparatus body 3. Here, it inputs directly to the ultrasonic measuring device main body 3 through the input means 8 such as a keyboard. When the bonding diameter is measured by the ultrasonic measuring device 1, the thickness T 1 of the upper plate 21, the thickness T 2 of the lower plate 22, and the residual base thickness Δt are automatically measured and automatically input to the ultrasonic measuring device body 3. You may do it.

Next, the operation will be described.
First, as shown in FIG. 4, the upper and lower surfaces of the upper plate 21 and the lower plate 22 joined by the friction stir spot welding method are reversed, and the surface of the lower plate 22 that forms a flat surface (the upper surface in FIG. 4) is The ultrasonic probe 4 is moved. The movement is performed so that the entire surface area of the surface of the lower plate 22 corresponding to the region including the joint portion of the upper plate 21 and the lower plate 22 is scanned.
During this movement, the ultrasonic probe 4 performs transmission / reception of ultrasonic waves continuously or intermittently, and the reflected wave (corresponding to the position of the ultrasonic probe 4 is transmitted to the control / processing unit 11 of the ultrasonic measurement apparatus main body 3. Many echo signals) are captured.
The first peak of the reflected wave appears in the reflected wave from the surface of the lower plate 22 in contact with the ultrasonic probe 4.
The second peak of the reflected wave is either on the surface (the lower surface in FIG. 4) side of the upper plate 21 from the position where the first peak is generated in the range of the total thickness T1 + T2 of the upper plate 21 and the lower plate 22. Appears in the reflected wave from the position of. In the central part of the joint between the upper plate 21 and the lower plate 22, a reflected wave from the lower surface (interface with the atmosphere) in FIG. In the portion excluding the central portion of the joint portion of the upper plate 21 and the lower plate 22, it usually appears in the reflected wave from the lower surface (interface with the atmosphere) in FIG.

The control / processing unit 11 performs non-destructive based on the reflected wave (first peak, second peak) data and the position data on the scanning surface of the ultrasonic probe 4 when the data is obtained. The distance (depth) to the ultrasonic reflection position at each position in the ultrasonic probe scanning region including the joint portion of the upper plate 21 and the lower plate 22 is measured.
For example, the upper and lower plates 21 and 22 in FIG. 4 from the surface of the lower plate 22 (upper surface in FIG. 4) in the ultrasonic probe scanning region depending on the ultrasonic reflection positions where the first and second peaks are generated. The distance to the bottom surface (interface with the atmosphere) is measured. The control / processing unit 11 further measures the distance, in other words, the longitudinal section contour shape data of the joint and its peripheral portion, and the ultrasonic probe scanning region, particularly at each position within the range of the shoulder diameter D. Depending on the intensity of the reflected wave, a plane image (see FIGS. 5 and 6) with the luminance corresponding to the intensity of the reflected wave as a pixel value can be displayed on the output means 9.

The joint diameter estimating means 12 obtains an estimated value (joint diameter φA: see FIG. 3) of the joint diameters of the upper and lower plates 21 and 22 by friction stir spot joining by ultrasonic measurement as described above.
Subsequently, the distance calculation means 13 obtains the above estimated value, and from the added value T3 of the length L (see FIG. 2) of the pin 23 related to the friction stir spot joining of the lower plates 21 and 22, and the residual base thickness Δt. The thickness T2 of the lower plate 22 is subtracted to obtain a distance ΔT between the pushing position of the shoulder 25 of the joining tool 24 and the back surface (the lower surface in FIG. 3) of the upper plate 21. The length L of the pin 23 and the residual base thickness Δt are input to the ultrasonic measurement apparatus main body 3 before execution of the joint diameter measurement of the friction stir joint. As for the remaining mother thickness Δt, the remaining mother thickness Δt measured at the time of the ultrasonic measurement may be automatically input to the ultrasonic measuring device body 3.
Then, when the distance ΔT obtained by the distance calculating means 13 exceeds a predetermined threshold value, the joining diameter determining means 14 uses the estimated values obtained by the joining diameter estimating means 12 as the upper and lower plates 21. , 22 is determined as a measured diameter φA ″ (measured joint diameter of the present invention) of the joint diameter.

Hereinafter, the threshold value and the setting of the threshold value when determining the bonding diameter will be described.
According to the experiments by the inventors, the conventional measurement of the diameter of the joints of the upper and lower plates 21 and 22 using ultrasonic measurement (estimated) result φA and the actual fracture surface of the joint (actually with a chisel, etc.) It was found that there was no correlation at all with the measurement result φA ′ of the bonding diameter by observation of the fracture surface fractured by shearing. In the conventional bonding diameter measurement, when a pressure contact surface is formed between the upper and lower plates 21, 22, this pressure contact surface region PE (see FIG. 3) cannot be distinguished from the diffusion bond region, and the pressure contact surface is not diffusion bonded. This is probably due to erroneous measurement that even the region PE is bonded.
If the images of the joint portions of the upper and lower plates 21 and 22 are measured correctly, the outer shape becomes a substantially circular image as illustrated in FIG. 5, but if measured incorrectly, the outer shape is illustrated in FIG. Becomes an image extending greatly outward from the circle.
In addition, in the two lines intersecting in an “x” shape in the images shown in FIGS. 5 and 6, the shorter one indicates the short diameter of the measured joint diameter, and the long one indicates the long diameter. In the image shown in FIG. 6, the difference between the major and minor diameters is large, and the circular shape indicating the joint is greatly distorted.

Therefore, the inventors decided to distinguish the pressure-contact surface region PE from the diffusion bonding region. According to the inventors' diligent research, first, the pressing position of the shoulder 25 of the welding tool 24 at the time of friction stir welding and the back surface (the lower surface in FIG. 3) of the upper plate 21 which is a member to be joined on the welding tool 24 side. Focused on the distance ΔT. When an appropriate threshold value is set for the distance ΔT and threshold processing is performed, and the threshold processing result is “OK” (for example, the distance ΔT exceeds the threshold value). Further, the inventors have found that it is possible to avoid erroneously detecting the pressure contact surface region PE as a diffusion bonding region.
According to this, when the above threshold value processing is performed on the distance ΔT and the result is “OK”, the above-mentioned joint diameter measurement result, that is, the joint diameter estimated value φA is used as the upper and lower plates. By determining the joint diameter as a measured value φA ″ of the joint diameter of the 21 and 22 joints (measured joint diameter of the present invention), the measured joint diameter of the present invention φA ″ is set to the true joint diameter φA ′ as much as possible. It will approach.

As an example of the threshold value, when the upper and lower plates 21 and 22 are made of an aluminum material and the thicknesses T1 and T2 are 0.9 mm, respectively, the threshold value is set to 0.6 mm.
In FIG. 3, when the distance ΔT exceeds 0.6 mm (ΔT> 0.6), the joint diameter estimated value φA is the true joint diameter φA ′ or a value near the true joint diameter φA ′. When the threshold value is an appropriate value, 0.6 in this example, the joint diameter estimated value φA is the boundary surface position between the upper and lower plates 21 and 22 (the position at the height T2 in FIG. 3). It is measured by. Therefore, the influence exerted by the pressure contact surface region PE is eliminated or reduced, and an erroneous determination that the bonding is performed while not being bonded is avoided. Accordingly, the joint diameter estimated value φA when the distance ΔT exceeds 0.6 mm is determined as the measurement joint diameter φA ″ according to the present invention, whereby erroneous measurement of the joint diameter φA ′ is avoided as much as possible, and the diffusion joint diameter is highly accurate. Can be measured.

  When the distance ΔT is equal to or less than the threshold value, here 0.6 mm or less (ΔT ≦ 0.6), the estimated bonding diameter φA is the shoulder diameter D or a value in the vicinity thereof. In this case, the estimated bonding diameter φA is erroneously determined as a position including the pressure contact surface region PE (non-bonded region), that is, because the upper and lower plates 21 and 22 are firmly pressed. Measured including position. Therefore, the joint diameter estimated value φA when the distance ΔT is 0.6 mm or less is not used as the measurement joint diameter φA ″ of the present invention, thereby avoiding erroneous measurement of the joint diameter φA ′.

When the distance ΔT is 0.6 mm or less (ΔT ≦ 0.6), it is assumed that the pressure contact surface region PE is formed on the outer peripheral side portion in the joint diameter estimated value φA. Thus, the joint diameter estimated value φA may be measured, and the joint diameter estimated value φA may be set as the measured joint diameter φA ″ of the present invention.
That is, in the case of ΔT ≦ 0.6, the joint diameter estimated value φA is slightly higher than the position of the boundary surface between the upper and lower plates 21 and 22, that is, the position of the height T2 in FIG. If the measurement is performed at the minimum height position α in a range where no detection is made, an erroneous determination due to the pressure contact surface area PE is avoided. Accordingly, when the estimated joint diameter φA at this time is described as a corrected joint diameter estimated value φA, the corrected joint diameter estimated value φA may be used as the measured joint diameter φA ″ of the present invention, which also causes an error in the joint diameter φA ′. Measurement is avoided and the diffusion bonding diameter can be measured with high accuracy.

The threshold value is set as follows, for example.
That is, friction stir spot welding is performed in advance on the same number of upper and lower plates 21 and 22 in advance. The joined upper and lower plates 21 and 22 are referred to as test pieces.
First, a temporary threshold is set, and divided into a test piece in which a measurement result exceeding the temporary threshold is obtained and a test piece in which a measurement result less than that value is obtained. '' Is determined (measured). After that, for each test piece, the joint diameter measurement result φA ′ by the fracture surface actually sheared with a chisel or the like is measured, and compared with the above provisional measurement joint diameter φA ″, the provisional threshold value is Determine whether the value is appropriate. If it is not an appropriate value, a new temporary threshold value is set, and it is determined whether or not the new temporary threshold value is an appropriate value through the same process as described above. Thereafter, this is repeated until the provisional threshold value is determined to be an appropriate value, and the threshold value used for the measurement of the measurement joint diameter φA ″ of the present invention is set.

  According to the above-described embodiment, an appropriate threshold value is set in measuring the joint diameter of the joint parts to be joined that are joined by the friction stir spot joining method, and the influence of the pressure contact surface area, that is, unjoined However, since the above-mentioned joint diameter is measured while avoiding an erroneous determination that the joints are joined, the joint diameters of the joint portions of the upper and lower plates 21 and 22 can be measured with high accuracy.

In the above embodiment, the method and the apparatus for measuring the bonding diameter have been described. However, based on the measurement result of the bonding diameter by such a method and apparatus, the quality of the bonded portion, for example, the measured value of the bonding diameter is determined in advance. It is also possible to inspect (non-destructive inspection) whether or not it is larger than a predetermined value.
As a friction stir welding quality inspection apparatus for performing such quality inspection, for example, in the above-mentioned friction stir welding portion joint diameter measuring device, whether or not the measured value of the joint diameter is larger than a predetermined value as described above. It is configured by adding a determination means for determining whether or not and an output means for outputting the determination result of the determination means. The determination unit may be configured to function by execution of a computer program, and may be added to the above-described bonding diameter measurement program and stored in the external storage unit. The output means for outputting the determination result of the determination means can also be used as the output means of the joining diameter measuring device for the friction stir welding portion.
Thus, by inspecting the quality of the joint based on the joint diameter measurement result of the joint diameter measuring device of the friction stir joint, the joint can be inspected nondestructively and with high accuracy.

1: Ultrasonic measuring device, 2: Bonding diameter measuring program, 3: Ultrasonic measuring device main body, 4: Ultrasonic probe, 5: Ultrasonic transmitting / receiving means, 8: Input means, 9: Output means, 11: Control / Processing means, 12: Joining diameter estimating means, 13: Distance calculating means, 14: Joining diameter determining means, 21: Upper plate, 22: Lower plate, 23: Pin, 24: Joining tool, 25: Shoulder, T1: Upper plate , T2: thickness of lower plate, ΔT: distance between shoulder push-in position of welding tool and upper plate back surface, D: shoulder diameter, L: length of pin, Δt: residual thickness, PE: pressure welding Surface area, φA: erroneous measurement junction diameter, φA ′: true junction diameter, φA ″: measurement junction diameter of the present invention.

Claims (6)

A method of measuring a bonding diameter of a bonded portion in which two overlapped members to be bonded are bonded by a friction stir spot bonding method,
A first step of obtaining an estimated value of the bonding diameter by ultrasonic measurement;
A second step of obtaining a distance between the position where the shoulder of the welding tool is pressed during friction stir welding and the back surface of the joined member on the side of the welding tool;
A third step in which the estimated value is a measured value of the joint diameter when the distance exceeds a predetermined threshold;
A method for measuring a joint diameter of a friction stir welded portion.   The distance obtained in the second step is the residual base thickness in the joint, the distance from the shoulder tip position to the pin tip position of the joining tool, and the thickness of the member to be joined on the opposite side of the joining tool side. 2. The method for measuring a joint diameter of a friction stir weld according to claim 1, wherein the joint diameter is calculated based on the above. An apparatus for measuring a bonding diameter of a bonded portion in which two overlapped members to be bonded are bonded by a friction stir spot bonding method,
A joining diameter estimating means for obtaining an estimated value of the joining diameter by ultrasonic measurement;
A distance calculating means for obtaining a distance between a position where the shoulder of the welding tool is pushed at the time of friction stir welding and a back surface of the member to be joined on the side of the welding tool;
A joining diameter determining means that uses the estimated value as a measurement value of the joining diameter when the distance exceeds a predetermined threshold;
A device for measuring a joint diameter of a friction stir joint, comprising:   The distance calculated by the distance calculating means is the remaining base thickness in the joint, the distance from the shoulder tip position of the joining tool to the pin tip position, and the thickness of the member to be joined on the opposite side of the joining tool side. 4. The apparatus for measuring a joint diameter of a friction stir weld according to claim 3, wherein the joint diameter is calculated based on the above. A method for inspecting a joint where two stacked members to be joined are joined by a friction stir spot joining method,
A friction stir welding quality inspection method, wherein quality of the joint is inspected based on a measurement result obtained by the method for measuring the diameter of a friction stir welding portion according to claim 1 or 2. An apparatus for inspecting a joint where two members to be joined are joined by a friction stir spot joining method,
Determination means for determining the quality of the joint based on the measurement result by the joint diameter measuring device of the friction stir joint according to claim 3 or 4,
Output means for outputting the determination result of the determination means;
A friction stir welding quality inspection apparatus comprising: