JP2015184076A - Welded part inspection device and method for inspecting welded part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method enabling inspection of a welded part with simple processes where materials are filler-welded together.SOLUTION: A welded part inspection device according to an embodiment of the present invention, includes: a vibration body 10 that applies shock on a first welded material of the first and a second welded materials welded together; a sensor 12 that measures a vibration intensity of a shock wave having passed from the first welded material to the second welded material through the welded part due to the shock; an operating unit 120 that operates a parameter for inspecting the welded part using the measured vibration intensity; and a magnetic material 310 at the end of an enclosure of the vibration body that makes the enclosure and the first welded material immediately close to each other.

Description

  The present invention relates to a welded part inspection apparatus and a welded part inspection method, and more particularly to an inspection method and an inspection apparatus for a welded part such as a bottom plate of a crude oil tank.

  The crude oil tank is formed by welding a metal plate such as carbon steel. For example, it is formed in a cylindrical shape. The crude oil tank has a diameter of, for example, 100 m, and the bottom plate of the crude oil tank is welded with a large number of plate materials without gaps. For example, fillet welding is performed between one end portion and the other surface by stacking plate members. Therefore, the number of the welded portions between the plate members and the total length of the welded portions of the respective plates are enormous. Such crude oil tanks require regular maintenance. At the time of maintenance, workers entered the dark tank from which crude oil had been removed and visually inspected the welds while illuminating the lights. . The inspection has been performed, for example, by measuring the throat thickness of fillet welds. However, since it is difficult to visually measure the throat thickness, the leg length or the like of the welded portion is measured and applied to a mold gauge or the like of the cross section to obtain the throat thickness by calculation. The labor required for workers to perform these measurements on a vast length of welded parts and perform throat thickness calculation on a pattern paper or the like at any time was immeasurable. Therefore, it is desirable that inspection can be performed with simpler work during maintenance. Thus, for example, a technique capable of inspecting a welded portion by a simple operation is desired for an inspection target in which fillet welding is performed by overlapping plate materials represented by a crude oil tank, for example.

  Here, for the throat thickness measurement of fillet weld, fillet weld the horizontal plate and the standing plate arranged on the back side of the horizontal plate, and scan with a phased array probe from the front side of the horizontal plate A method for measuring the throat thickness value of a fillet weld is disclosed (see, for example, Patent Document 1). Such a method is intended for the fillet welding of a horizontal plate and a vertical plate, and therefore has a different structure from the bottom plate of a crude oil tank. In addition, in the case of such a technique, it is necessary to apply grease to the probe in order to efficiently propagate the ultrasonic wave to the detected portion, and there is a problem that work operability is poor. And this method measures from the back surface of a non-welding material. Therefore, this method is not suitable for inspection of the bottom plate of the crude oil tank.

JP 2007-147548 A

  Therefore, the present invention provides an apparatus and method that can overcome the above-described problems and can inspect a welded part with a simple operation on an inspection object in which the welded materials are fillet welded together. With the goal.

The welded part inspection apparatus according to one aspect of the present invention includes:
Of the welded first and second welded materials, a vibrating body that applies an impact to the first welded material;
A sensor for measuring the vibration strength of the shock wave propagated from the first workpiece to the second workpiece through the weld by the impact;
A calculation unit that calculates the inspection parameters of the weld using the measured vibration strength,
Table,
A plurality of legs supporting the table;
A first shaft arranged to be movable in a direction perpendicular to the table surface of the table through a first opening formed in the table;
A first universal joint that connects the tip end of the first shaft on the table surface side supported by the plurality of legs and the vibrating body so that the joining angle can be freely changed;
A second shaft arranged to be movable in a direction orthogonal to the table surface of the table through a second opening formed in the table;
A second universal joint for connecting the tip of the second shaft on the table surface side supported by the plurality of legs and the sensor so that the joining angle can be freely changed;
A magnet member disposed at the tip of the housing of the vibrating body and causing the housing of the vibrating body to be in close contact with the first workpiece;
It is provided with.

  In addition, it is preferable to further include a spring member that presses the sensor toward the second material to be welded.

  Further, it is preferable to further include a sheet member disposed at the tip of the sensor and in contact with the second workpiece.

  In addition, it is preferable to further include a plurality of magnet members arranged at the tips of the corresponding legs of the plurality of legs.

  Further, it is preferable to further include a suppression guide that suppresses the movement of the angle of the second universal joint.

The welded part inspection method according to an aspect of the present invention includes:
A vibrating body is disposed on the first welded material across a welded portion where the first and second welded materials are fillet welded, and the gap between the tip of the housing of the vibrating body and the first welded material A step of applying an impact to the first workpiece using a vibrating body in a state where the magnet member is closely attached and the sensor is disposed on the second workpiece;
Using a sensor to measure the vibration strength of a shock wave propagated from the first workpiece to the second workpiece through the weld by impact;
Using the measured vibration strength to calculate a weld inspection parameter;
It is provided with.

  According to one aspect of the present invention, it is possible to inspect a welded portion with a simple operation on an inspection object in which fillets are welded to each other. Furthermore, the casing of the vibrating body can be brought into close contact with a material to be welded that is one of measurement objects. Therefore, the contact condition of the vibrating body can be kept constant.

It is a conceptual diagram which shows an example of the apparatus structure of the welding part inspection apparatus in Embodiment 1. FIG. FIG. 3 is a perspective view of a jig part of the welded part inspection apparatus in the first embodiment. 3 is a diagram illustrating a configuration of a tip portion of a vibrating body in the first embodiment. FIG. 2 is a conceptual diagram illustrating an example of an internal configuration of a control circuit in Embodiment 1. FIG. 3 is a cross-sectional view showing an example of an inspection target in Embodiment 1. FIG. FIG. 5 is a flowchart for explaining a main process of the welded part inspection method in the first embodiment. 6 is a diagram showing an example of a shock wave profile including a direct current component in Embodiment 1. FIG. 6 is a diagram showing an example of a shock wave profile in the first embodiment. FIG. 4 is a diagram showing an example of a cross section of a test piece in Embodiment 1. FIG. 4 is a graph showing an example of correlation data between a peak voltage and a throat thickness in the first embodiment. FIG. 4 is a conceptual diagram for explaining an example of a peak voltage calculation method in the first embodiment.

Embodiment 1 FIG.
FIG. 1 is a conceptual diagram showing an example of the apparatus configuration of a welded part inspection apparatus according to Embodiment 1. In FIG. 1, the welded part inspection apparatus 100 includes a jig part 150 and a control part 160.

  FIG. 2 is a perspective view of the jig portion of the welded portion inspection apparatus in the first embodiment. 1 and 2, the jig 150 includes a vibrating body 10, a sensor 12, a table 14, shaft members (shafts) 16 and 18, universal joints (universal couplings) 20 and 22, a plurality of legs 23 and 24, and a plurality of legs. Male screw 25, a plurality of height adjustment blocks 26, a plurality of knurled nuts 28, guides 30 and 32, retaining members 34 and 36, a spring material 302, a magnet member 310, a sheet 312, a restraining guide 322, and a magnet member 323. , 324.

  The back surface of the table 14 is supported by a combination of, for example, two legs 23 having a fixed height and, for example, two sets of legs 24 and male screws 25 capable of adjusting the height. For example, the side of the table 14 on which the vibrating body 10 is arranged is supported by, for example, two legs 23 having a fixed height. Conversely, the side of the table 14 on which the sensor 12 is disposed may be supported by a combination of, for example, two sets of legs 24 and male screws 25 that are adjustable in height. The leg 24 is formed shorter than the leg 23. A male screw 25 is combined with the end of the leg 24 on the table 14 side. A knurled nut 28 is disposed at the tip of the male screw 25, and the male screw 25 can be rotated by the knurled nut 28. The male screw 25 is connected to the leg 24 via a height adjustment block 26 in which a female screw fixed to the back surface of the table 14 is formed. Therefore, the male screw 25 and the female screw of the height adjusting block 26 are engaged with each other, and the length of the male screw 25 protruding to the back side of the table 14 can be adjusted.

  In each of the left and right areas of the table 14, two openings 31 and 33 are formed, one by one, and the guide 30 is incorporated in one opening 31 (first opening). A guide 32 is incorporated in the other opening 33 (second opening). The shaft member 16 (second shaft) is disposed so as to be movable by the guide 30 in a direction orthogonal to the table surface of the table 14 through the opening 31 formed in the table 14. Further, the shaft member 18 (first shaft) is disposed so as to be movable by the guide 32 in a direction orthogonal to the table surface of the table 14 through the opening 33 formed in the table 14. For example, linear guides are preferably used as the guides 30 and 32. Thereby, the shaft members 16 and 18 can move smoothly in the vertical direction. Alternatively, as the guides 30 and 32, for example, a slide bearing or the like is suitable. Alternatively, the shaft member 16 may slide on the side surface of the opening 31 and the shaft member 18 may slide on the side surface of the opening 33 without using the guides 30 and 32.

  Of the two tip portions of the shaft member 18, the tip portion on the table surface (back surface) side supported by the plurality of legs 23 and 24 and the vibrating body 10 are connected by a universal joint 22 (first universal joint). Yes. By connecting with the universal joint 22, the joining angle can be freely changed. For example, a solenoid or the like is preferably used as the vibrating body 10. Of the two tip portions of the shaft member 16, the tip portion on the table surface (back surface) side supported by the plurality of legs 23 and 24 and the sensor 12 are connected by a universal joint 20 (second universal joint). . By connecting with the universal joint 20, the joining angle can be freely changed. The vibration sensor 12 preferably has a measurement frequency of 10 Hz to 15 kHz, for example. However, the present invention is not limited to this. It suffices to have a frequency band in which the impact from the vibrating body 10 can be measured. Further, for example, those having a measurement range of about 1000 mV are suitable. Also, the shaft member 16 has a larger outer diameter than the inner diameter of the opening 31 or the guide 30 at the other end of the shaft member 16 so that the shaft member 16 does not come out of the opening 31 of the table 14 due to an impact from the vibrating body 10 or the like. A stop member 34 is disposed. Similarly, a retaining member 36 having an outer diameter larger than the inner diameter of the opening 33 or the guide 32 is disposed at the other end of the shaft member 18. The center-to-center distance between the vibrating body 10 and the sensor 12 may be set as appropriate, but is longer than the leg length of the welded portion 54 and is set to, for example, about 60 mm. A sheet member 312 is disposed at the tip of the sensor 12. Therefore, when the sensor 12 is set on the plate material 50 (second welded material) to be inspected, the sheet member 312 comes into contact with the plate material 50. By sandwiching the sheet member 312 between the sensor 12 and the plate material 50, it is possible to prevent a gap from being left between the sensor 12 and the plate material 50 even when the surface of the plate material 50 is uneven. The sheet member 312 may be a flexible material such as a vinyl sheet.

  Furthermore, in the first embodiment, the spring member 302 is disposed between the guide 30 and the universal joint 20. The spring member 302 is preferably arranged so that the shaft member 16 can move within the spring member 302. Since the guide 30 is fixed to the table 14, the sensor 12 is configured to be disposed on the plate member 50 at a position where the spring member 302 is contracted, so that the sensor 12 is pressed toward the plate member 50 by the elastic force of the spring member 302. it can. As a result, the sensor 12 can be brought into close contact with the plate member 50 via the sheet member 312. The elastic force of the spring member 302 may be about 3N, for example. However, the present invention is not limited to this. Other elastic forces may be used. Here, in order to prevent the table 14 from being lifted by the elastic force of the spring member 302, the magnet member 324 is provided at each end of the two sets of legs 24 opposite to the table 14 side (the plate 52 side to be inspected). Is fixed by magnetically attaching to the plate material on which the legs 24 are placed (to prevent the legs 24 from floating). Similarly, magnet members 323 are arranged at the ends of the two sets of legs 23 opposite to the table 14 side (the plate material 50 side to be inspected), and are attached to the plate material on which the legs 23 are placed by a magnetic force. Fix (prevent leg 23 from floating). In this way, the plurality of magnet members 323 and 324 are arranged at the tips of the corresponding legs of the plurality of legs 23 and 24, respectively.

  Furthermore, in the first embodiment, the suppression guide 322 is fitted on the outer peripheral side of the universal joint 20 so that the angle of the universal joint 20 is not bent by the elastic force of the spring member 302. By fitting the suppression guide 322 on the outer peripheral side of the universal joint 20, the angular movement of the universal joint 20 can be suppressed to such an extent that it is not bent by the elastic force of the spring member 302. For example, a cylindrical heat-shrinkable resin tube is preferably used as the suppression guide 322.

  FIG. 3 is a diagram illustrating a configuration of a tip portion of the vibrating body in the first embodiment. 3A shows a cross-sectional view, and FIG. 3B shows a bottom view. The vibrating body 10 includes a vibrating element 350 that actually generates vibration and a casing 352 that covers the periphery of the vibrating element 350. In the first embodiment, the magnet member 310 is disposed at the tip of the housing of the vibrating body. The magnet member 310 is preferably formed, for example, in a hollow cylindrical shape in accordance with the outer peripheral shape of the housing 352. Thereby, it can arrange | position without gap with respect to the circumferential direction of the front end surface of the housing 352. FIG. The magnet member 310 brings the casing 352 of the vibrating body 10 into close contact with the plate material 52 (first material to be welded). Thereby, the contact condition with respect to the board | plate material 52 of the vibrating body 10 at the time of giving a hit can be made substantially constant. Therefore, it is possible to eliminate the need to adjust the contact condition of the vibrating body 10 with the plate member 52 in order to give a good impact.

  The control unit 160 includes a control computer 110, a memory 111, an interface (I / F) circuit 119, a control circuit 120, and a storage device 140 such as a magnetic disk device. The control computer 110, the memory 111, the I / F circuit 119, the control circuit 120, and the storage device 140 are connected to each other via a bus (not shown).

  In the control computer 110, a measurement unit 70 and a parameter calculation unit 72 are arranged. Each function such as the measurement unit 70 and the parameter calculation unit 72 may be configured by software such as a program. Alternatively, it may be configured by hardware such as an electronic circuit. Alternatively, a combination thereof may be used. Necessary input data or calculated results in the control computer unit 110 are stored in the memory 111 each time. When at least one of the measurement unit 70 and the parameter calculation unit 72 is configured by software, a calculator such as a CPU or a GPU is arranged.

FIG. 4 is a conceptual diagram illustrating an example of the internal configuration of the control circuit according to the first embodiment. In FIG. 3, the control circuit 120 includes a calculator unit 112, a DC component removal circuit 114, an amplifier 116, and a drive circuit 118. In the calculator unit 112, acquisition unit 80, _{T 0} calculation unit 82, _{V 0} calculation unit 84, a memory 86, and the control unit 88 is arranged. Each features such acquisition unit 80, _{T 0} calculation unit 82, _{V 0} calculation unit 84, and the control unit 88 may be configured by software such as programs. Alternatively, it may be configured by hardware such as an electronic circuit. Alternatively, a combination thereof may be used. Necessary input data or calculated results in the calculator unit 112 are stored in the memory 86 each time. When at least one of the acquisition unit 80, the T ₀ calculation unit 82, the V ₀ calculation unit 84, and the control unit 88 is configured by software, a calculator such as a CPU or a GPU is arranged.

  Here, in FIGS. 1-4, the structure required when describing Embodiment 1 is described. The welded part inspection apparatus 100 may normally have other necessary configurations.

FIG. 5 is a cross-sectional view showing an example of an inspection object in the first embodiment. The plate material 50 (second welded material) and the plate material 52 (first welded material) to be inspected are overlapped and, for example, fillet welded between the end of the plate material 52 and the surface of the plate material 50. ing. Here, for example, a carbon steel plate material is used. However, the present invention is not limited to this. Other weldable metal materials may be used. Moreover, for example, a material of length 1.2 m × width 1 m × thickness 9 mm is used. However, the present invention is not limited to this. The vertical and horizontal sizes and thicknesses may be other sizes. As shown in FIG. 5, a welded portion 54 is formed at the joint between the plate material 52 and the plate material 50 by fillet welding. In the first embodiment, to measure for example the throat thickness L ₁ of the welded portion 54 as an inspection parameter of the weld 54. Here, for example, the length from the intersection O between the surface of the plate material 50 and the side surface of the end portion of the plate material 52 to the fillet surface of the welded portion 54 at an angle of 45 ° with respect to the surface of the plate material 50 is measured as a throat thickness. However, the definition of throat thickness is not limited thereto, for example, 0.7 times the value of leg length L ₂ of the welded portion 54 (or the leg length L ₂ divided by √2) as throat thickness a Good. Therefore, it is also preferable to use, for example, the leg length L ₂ of the welded portion 54 in addition to the throat thickness L ₁ as the inspection parameter. In the example of FIG. 4, welding is performed so that the leg length L ₂ (bottom side length) of the welded portion 54 is longer than the height (thickness of the plate member 52), but is not limited thereto. If the welding strength is sufficient, the cross section of the welded portion 54 may have a right isosceles triangle shape in design.

  In measuring such inspection parameters, first, the jig portion 150 of the welded portion inspection apparatus 100 is arranged on the plate material 50 and the plate material 52 to be inspected. As shown in FIG. 1, the vibrating body 10 is disposed on the surface of the plate member 52 with a welded portion 54 obtained by fillet welding the plate members 50 and 52 interposed therebetween. And the sensor 12 is arrange | positioned on the board | plate material 50 surface. The jig part 150 is arranged in accordance with such a position. In the example of FIG. 1, two legs 23 are placed on the surface of the plate material 50. Then, the two legs 24 are placed on the surface of the plate member 52 whose height is increased by overlapping the plate member 52 on the plate member 50. The table 14 is arranged as horizontally as possible by adjusting the height on the two legs 24 side. The vibrating body 10 and the sensor 12 are arranged in a direction orthogonal to the weld line of the welded portion 54. More preferably, it is suitable to arrange so as to be in a substantially line-symmetrical position with respect to the weld line of the weld portion 54. Since the vibrating body 10 and the shaft member 18 are connected by the universal joint 22, even if the table 14 fixing the shaft member 18 deviates from the horizontal state, the vibrating body 10 has a contact area with the plate member 52 so as to increase. Can be installed. In other words, it can be installed horizontally. Therefore, unevenness (error) of the applied impact value can be suppressed. Similarly, since the sensor 12 and the shaft member 16 are connected by the universal joint 20, even if the table 14 that fixes the shaft member 16 deviates from the horizontal state, the sensor 12 has a large contact area with the plate member 50. Can be installed. Therefore, the detection error of the detected vibration intensity can be reduced.

  Here, in order to suppress variation in each measurement due to the positional relationship between the vibrating body 10 and the vibration sensor 12 with respect to the weld line, a light source that emits light (not shown) or a plurality of linearly arranged light sources are arranged between the vibrating body 10 and the vibration sensor 12. It is also preferable to irradiate the boundary between the welding line and the plate material 52 from a point light source. The power cable for driving the vibrating body 10 and the measurement cable for the vibration sensor 12 are preferably connected to the control unit 160 from a connector (not shown) provided on the table 14, for example. Thereby, if a cable is removed, the jig | tool part 150 and the control part 160 can be carried separately.

  In the example of FIG. 1, the vibrating body 10 is disposed on the upper plate member 52 and the sensor 12 is disposed on the lower plate member 50. However, the present invention is not limited to this. Good.

  FIG. 6 is a flowchart for explaining a main process of the welded part inspection method according to the first embodiment. In FIG. 6, a command transmission step (S102), an impact application step (S104), a vibration intensity measurement step (S106), a DC component removal step (S108), a shock wave profile acquisition step (S110), and a peak time calculation A series of steps of a step (S112), a peak voltage calculation step (S114), and a parameter calculation step (S116) are performed.

  In the command transmission step (S102), the measurement unit 70 transmits a measurement start command to the control circuit 120. Within the control circuit 120, the calculator unit 112 inputs a measurement start command. Then, the control unit 88 in the calculator unit 112 outputs a signal instructing the drive circuit 118 to apply an impact.

  As the impact applying step (S104), the vibrating body 10 is disposed on the plate member 52 with the weld 54 interposed therebetween, the tip of the housing 352 of the vibrating member 10 and the plate member 52 are brought into close contact with each other by the magnet member 310, and a sensor is attached to the plate member 50. In a state where 12 is disposed, the drive circuit 118 drives the vibrating body 10 and applies an impact to the plate member 52. The drive circuit 118 sets the measurement start time 0 to T1 to 0 V, and applies the voltage driven by the vibration body 10 to the vibration body 10 during the subsequent times T1 to T2. The impact may be applied once. If the sound velocity of the iron plate is 5950 m / s, for example, the wavelength of 15 kHz is about 40 cm, which is sufficiently longer than the thickness of the plate members 50 and 52 and the outer diameter dimension of the cross section of the welded portion 53. Thereby, the wave which has propagated through the entire weld can be detected. Therefore, it is possible to detect a wave that has sufficiently propagated through the entire weld with a single shock wave. However, the present invention is not limited to this, and a plurality of impacts may be applied. However, when a plurality of impacts are applied, it is preferable that the impact is applied after the previous shock wave is attenuated. The impact load by the vibrating body 10 is preferably such that the sensor 12 can obtain a vibration strength of about several hundred mV. However, the present invention is not limited to this. You may set suitably according to the performance of a sensor.

  As the vibration strength measurement step (S106), the sensor 12 detects (measures) the vibration strength of the shock wave 60 propagated from the plate material 52 to the plate material 50 through the welded portion 54 due to the impact on the plate material 52. The sensor 12 detects the vibration intensity of the shock wave between the times T1 and T2 described above. As a result, measurement errors due to time lag can be prevented. The detection result of the sensor 12 is output to the amplifier 116 and amplified.

  In the DC component removal step (S108), the DC component removal circuit 114 removes the DC component from the output of the amplifier 116.

  FIG. 7 is a diagram showing an example of a shock wave profile including a direct current component in the first embodiment. In FIG. 7, the vertical axis represents vibration intensity and the horizontal axis represents time. The measured vibration intensity of the shock wave may include a bias component (DC component). In the example of FIG. 7, the entire shock wave profile is shifted by about 100 mV. Therefore, the DC component removal circuit 114 removes the DC component and adjusts the state where the vibration intensity value before the measurement is not touched to zero. Moreover, when the direct current component is not included, the direct current component removal step (S108) may be omitted.

  As the shock wave profile acquisition step (S110), the acquisition unit 80 acquires a shock wave profile from the DC component removal circuit 114.

  FIG. 8 is a diagram showing an example of a shock wave profile in the first embodiment. In FIG. 8, the vertical axis indicates the vibration intensity, and the horizontal axis indicates time. In the example of FIG. 8, an example of the shock wave profile from which the DC component is removed is shown. In the example of FIG. 8, the time axis is adjusted with time T1 as time 0.

As a peak time calculation step (S112), the T ₀ calculation unit 82 calculates a time T ₀ from the measurement start (T1) time to the peak (maximum value) A time of the measured vibration intensity. Alternatively, the time from a certain reference time may be calculated. Here, the time of the maximum voltage (or the time from the measurement start (T1) time) may be calculated from the time-series data of the vibration intensity (voltage) obtained at the sampling period.

As the peak voltage calculation step (S114), the V ₀ calculation unit 84 calculates the peak voltage V ₀ (maximum voltage) of the measured vibration intensity corresponding to the time T ₀ . The calculated peak voltage V ₀ is output to the control computer 110.

FIG. 9 is a diagram showing an example of a cross section of the test piece in the first embodiment. Prior to the inspection, correlation data between the peak voltage V ₀ and the inspection parameter is acquired in advance. For this purpose, a plurality of test pieces are prepared in which the inspection parameters of the welded portion are made variable with the same material, the same plate thickness, the same plate width, and the like as the inspection object. In the example of FIG. 9, the throat thickness of the weld is used as the inspection parameter. FIG. 9A shows an example of a test piece that is welded substantially similar to the throat thickness of a design in which a welded portion 55a in which the plate material 51a and the plate material 53a are fillet welded is a right triangle. FIG. 9B shows an example of a test piece in which the fillet surface of the welded portion 55b obtained by fillet welding the plate material 51b and the plate material 53b is recessed (the throat thickness is smaller than the designed throat thickness). FIG. 9C shows an example of a test piece in which the fillet surface of a welded portion 55c obtained by fillet welding the plate material 51c and the plate material 53c is convexly bulged (the throat thickness is larger than the designed throat thickness). . A plurality of test pieces with variable throat thicknesses as shown in FIG. 9 are prepared, the same impact is applied to each test piece, and the peak voltage V ₀ is measured. In addition, conditions such as the installation location (fixing method) are also matched to the inspection object. The value of the throat thickness of each test piece may be measured from the cross section.

FIG. 10 is a graph showing an example of correlation data between the peak voltage and the throat thickness in the first embodiment. In FIG. 10, the vertical axis indicates the vibration intensity and the horizontal axis indicates the throat thickness. The peak voltage V ₀ obtained from a plurality of test pieces having variable throat thickness values is plotted, and the approximate expression is calculated by approximating the measurement points. In the example of FIG. 10, for example, an approximate expression (y = ax + b) that is linear proportional is obtained. The data of the approximate expression is stored in the storage device 140 as correlation data between the peak voltage V ₀ and the inspection parameter.

  As the parameter value calculation step (S116), the parameter calculation unit 72 reads correlation data (for example, an approximate expression or a coefficient of the approximate expression) stored in the storage device 140, and uses the measured vibration intensity as correlation data (for example, an approximate expression). And the throat thickness (an example of an inspection parameter) of the welded portion 53 is calculated. The calculation result is output to a display device (for example, a monitor) (not shown) via the I / F circuit 119. What is necessary is just to determine the usability (safety) of the welding part 53 using the output throat thickness.

  By inspecting as described above, it is possible to inspect the welded portion 53 with a simple operation with respect to the inspection target in which the welded materials are fillet welded.

FIG. 11 is a conceptual diagram for explaining an example of a peak voltage calculation method according to the first embodiment. For example, the sampling period by the sensor 12 may not coincide with the actual peak voltage time, and the peak voltage may not be detected. In this case, in the peak time calculation step (S112), the T ₀ calculation unit 82, for example, from the measurement start (T1), for example, a plurality of times T _n−1 and T _n that are assumed to be near the detected data peak. , T _{n + 1} . Times T _n−1 , T _n , and T _{n + 1} are synchronized with the sampling period. Then, the vibration intensities at these plural times T _n−1 , T _n , T _{n + 1} are plotted and approximated by a polynomial. Then, as the peak voltage calculation step (S114), the V ₀ calculation unit 84 calculates the peak voltage V ₀ (maximum voltage) of the vibration intensity from the approximated curve. Thereby, the voltage T ₀ closer to the actual peak voltage can be calculated.

Here, although the peak voltage V ₀ is used in the above-described example, the present invention is not limited to this. For example, a difference value (difference voltage) between the maximum value A and the minimum value B of the vibration intensity shown in FIG. 7 may be used. In such a case, it is needless to say that correlation data between the maximum value of the vibration intensity and the difference voltage of the minimum value of the throat thickness is acquired as the correlation data in advance by using the plurality of test pieces described above. Then, the V ₀ calculation unit 84 may calculate not only the peak voltage V ₀ but also the minimum voltage and further calculate the difference voltage between them.

  The embodiments have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, the leg length may be used as the inspection parameter as described above. In such a case, it is necessary to conduct an experiment in advance using a plurality of test pieces having variable leg lengths, and to obtain correlation data between the peak voltage (maximum value) of the vibration intensity and the leg length of the weld as correlation data. Needless to say. Or the correlation data of the difference voltage of the maximum value of vibration intensity and the minimum value, and the leg length of a welding part should just be acquired.

  In addition, although descriptions are omitted for parts and the like that are not directly required for the description of the present invention, such as a device configuration and a control method, a required device configuration and a control method can be appropriately selected and used.

  In addition, all welded part inspection methods and welded part inspection apparatuses that include the elements of the present invention and that can be appropriately modified by those skilled in the art are included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Vibration body 12 Sensor 14 Table 16, 18 Shaft member 20,22 Universal joint 23,24 Leg 25 Male screw 26 Height adjustment block 28 Knurled nut 30,32 Guide 31,33 Opening part 34,36 Retaining member 60 Shock wave 70 Measurement unit 72 Parameter calculation unit 80 Acquisition unit 82 T ₀ calculation unit 84 V ₀ calculation unit 86 Memory 88 Control unit 100 Welded part inspection device 110 Control computer 111 Memory 112 Computer unit 114 DC component removal circuit 116 Amplifier 118 Drive circuit 119 I / F circuit 120 Control circuit 140 Storage device 150 Jig part 160 Control part 302 Spring material 310 Magnet member 312 Sheet 322 Suppression guides 323 and 324 Magnet member

Claims (6)

Of the welded first and second welded materials, a vibrating body that applies an impact to the first welded material;
A sensor for measuring the vibration strength of a shock wave propagated from the first work piece to the second work piece through the weld by the impact;
A calculation unit that calculates the inspection parameter of the weld using the measured vibration strength,
Table,
A plurality of legs supporting the table;
A first shaft arranged to be movable in a direction orthogonal to the table surface of the table through a first opening formed in the table;
A first universal joint that connects the tip of the first shaft on the table surface side supported by the plurality of legs and the vibrating body so that a joining angle can be freely changed;
A second shaft arranged to be movable in a direction perpendicular to the table surface of the table through a second opening formed in the table;
A second universal joint that connects the tip of the second shaft on the table surface side supported by the plurality of legs and the sensor so that the angle at which the sensor is joined can be freely changed;
A magnet member disposed at a tip of the housing of the vibrating body, and causing the housing of the vibrating body to be in close contact with the first material to be welded;
A welded part inspection apparatus comprising:   The welded portion inspection apparatus according to claim 1, further comprising a spring member that presses the sensor toward the second material to be welded.   The welded portion inspection apparatus according to claim 1, further comprising a sheet member disposed at a tip of the sensor and in contact with the second material to be welded.   The welded part inspection apparatus according to any one of claims 1 to 3, further comprising a plurality of magnet members disposed at tips of corresponding legs of the plurality of legs.   The welded portion inspection apparatus according to any one of claims 1 to 4, further comprising a suppression guide for suppressing movement of an angle of the second universal joint. A vibrating body is disposed on the first welded material across a welded portion where the first and second welded materials are fillet welded, and the tip of the housing of the vibrating body and the first welded material A step of applying an impact to the first material to be welded using the vibrating body in a state where a sensor is disposed on the second material to be welded,
Measuring the vibration strength of a shock wave propagated from the first welded material to the second welded material through the weld by the impact using the sensor;
A step of calculating an inspection parameter of the weld using the measured vibration strength;
A method for inspecting a welded portion.

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