TWI325496B - - Google Patents

Description

1325496 IX. Description of the Invention: [Technical Field] The present invention relates to a method for detecting and a test system thereof, and more particularly to a method for detecting flaws in a weld bead and a test system therefor. [Prior Art] The welding process for sheet metal parts in the automotive industry, machinery and aerospace industry is a very important manufacturing process, especially in the quality of welding.

surface. Therefore, the weld bead (or weld joint) is “defective and requires a set of inspection equipment for inspection and testing. At present, the commonly used welding defect detection methods include ultrasonic detection, dynamic resistance, or instantaneous measurement of the electrical impedance function in the splicing. 'Super chopping detection refers to the detection of the internal plague of the welded object to be tested with ultrasonic waves of low energy and high frequency. The frequency range used for ultrasonic detection is from z to 25 MHz, and the basic equipment needs to have electrons. The signal generator 'transmits the ultrasonic wave' through the Transducer of Pr〇be, or the search Umt, and then passes through the contact medium (4) into the object to be tested. Ultrasonic waves will have more or less clothing reduction in the object to be tested. When passing to different material interfaces, the ultrasonic waves may reflect or transmit. Therefore, by detecting, analyzing reflection or transmitting signals, the ultrasonic waves can be detected. Determine the detection position. Ultrasonic penetration is high, it can be used to inspect thick objects and it is harmless to the body. However, ultrasonic detection requires a profound technique (4), and is not suitable for (4) or coarse particles of crystal grains. It is not suitable for thin objects, etc., which is the biggest disadvantage of ultrasonic detection. Another-known solder joint method is achieved by measuring dynamic resistance 5 1325496 (Dynamic Resistance). After the test object is passed into the alternating current, the peak value of the voltage measured every half cycle is divided by the peak value of the current measured in the half cycle to obtain the dynamic resistance. Among them, one cycle can be set to lake seconds (for 6 〇 H \ frequency). However, the measurement method of the dynamic resistance has only two data per cycle, which is too simple, and the voltage peak and the current peak have a -time difference, so the resulting dynamic resistance is only an approximation similar to the actual value. < 幵—筲知

> The bar defect detection method and detection device measure the electrical impedance function instantaneously in the welding process. The conventional detecting device is combined with a spot welding device. When the spot welding device is welded - the object to be welded, the detecting device instantly measures the current signal between the two electrodes of the spot welding system and (4) the signal, = when spot welding The electrode is connected to a high current, and the current must be reduced by the _current comparator to measure the appropriate current value, and then the Hilbert (10) _ rans 0rm) conversion operation is used to obtain the immediate electrical impedance (4) he (10)) signal two measurements: Γ can According to the electrical impedance signal, it is known that the possible fresh joint defect measuring device can only measure the voltage and the thunder during the welding process of the welding device, and the welding object (the welding object) After 2 towels, the welding defects of the cold towel can not be detected. The j-bar is as described above, and these conventional knowledge is that it is impossible to accurately measure the limitation of the detection method of the welded joint, or the result, therefore, it is necessary to seek a solution [invention] that a weld bead defect is provided. The object of the invention is therefore the object of the invention, 1325496. Another object of the invention is to provide a test system for the detection of weld bead defects. The method for inspecting the weld bead of the present invention comprises the following steps: 'The weldment to be tested connected to the two electrodes is continuously passed through the intersection = two and measured (four) between the electrodes - the predetermined time - analog current signal = electricity wish signal. Then, the analog current signal and the analog current are respectively converted. "The electric signal is a digital current function and a digital voltage function. Lack = 'The digital current function and the digital electric function are respectively converted into a complex number; and the complex electric house function' where the complex current function and the complex = The fort function consists of the real part and the imaginary part of the _Hilbert conversion equation. Then 'divide the complex electric function by the complex current function and pass it to an electrical impedance value. Then' the electrical impedance The function is converted into an electrical impedance waveform to display the weld bead defect of the weldment to be tested. The test system for weld bead defect detection of the present invention is suitable for analyzing a test to be tested and includes a test platform unit and a current measurement. a unit, a voltage measuring unit, an analog-to-digital converting unit group, a processing unit, and a round-out unit. The test platform unit includes two electrodes electrically connected to the fresh end of the solder to be tested, and electrically connected to the electrodes And providing a power module of the AC power source. The power module is configured to continuously input AC power to the one to be tested after welding. The current measuring unit is electrically connected to the test platform unit. And measuring the analog current signal between the electrodes. The voltage measuring unit is electrically connected to the test platform unit 'and is used to measure the analog voltage signal 7 1325496 between the electrodes. The analog to digital conversion unit group is electrically connected. The electric current measuring unit and the voltage detecting unit convert the analog current signal and the analog voltage signal into a digital current function and a digital voltage function respectively. The processing unit is electrically connected to the analog to digital conversion unit group, and includes An operation module, wherein the operation module is configured to convert the digital current function and the digital voltage function into a complex current function and a complex voltage function, and calculate an electrical impedance function and an electrical impedance waveform. The complex current function and the complex voltage function respectively comprise a real part and an imaginary part calculated by a Hilbert conversion equation. The output unit is electrically connected to the processing unit for displaying the electrical impedance waveform. Accurately measuring the electrical impedance function of the fresh component to be tested after welding and generating a corresponding electrical impedance waveform for inspection The test personnel can understand whether the weld to be tested is defective. [Embodiment] The foregoing and other technical contents, features and effects of the present invention are described in the following detailed description of two preferred embodiments with reference to the drawings. Will be clearly presented. Before the invention is described, it should be noted that

In the following description, the 7L pieces of the _ 7 L Bay U are indicated by the same reference numerals. Referring to the drawings, the first preferred embodiment of the test system for the detection of weld bead defects, the preferred embodiment of the invention, the analysis of the appropriate poems, the welding of the material m weldment, and the inclusion of a test platform unit 2, a Leifa 曰 3 1: machine The measuring unit 3, a voltage measuring unit, an analog to digital conversion unit, a processing unit 6, and a wheeling unit, the test platform unit 2 is electrically connected to the electrode 21 of the 8 1325496 end of the to-be-tested weldment and an electrical connection The electrodes 2ι provide a power mode of the AC power source. The 22 power module 22 is used to continuously input AC power to the weldment 1 to be tested. The power module 22 can provide the AC generator. The AC power required for measuring the platform unit 2 can also change the external AC power source into a stable, continuous and appropriate current and electric dust, and the AC current value of the 4 weldment 1 to be tested must be based on the welding to be tested. The current measuring unit 3 is electrically connected to the test platform unit 2 and is used to measure an analog current signal between the electrodes 21 of the test platform unit 2. The voltage measuring unit 4 is electrically connected to the testing platform Element 2, and is used to measure the analog voltage signal between the electrodes 21 of the flat panel D unit 2. The analog to digital conversion unit group 5 is electrically connected to the current measuring unit 3 and 6 hai voltage 3: measuring unit 4 And converting the analog current signal and the analog voltage signal into a digital current function and a digital voltage function, wherein the analog to digital conversion unit group 5 can be a single digital analog converter, and the input analog current signal And the analog voltage signal is converted into a corresponding digital current function and a digital voltage function. However, the analog to digital conversion unit group 5 is not limited to the above embodiment, and may be a current analog to digital converter 51 and a voltage analogy. The analog converter 52 is electrically connected to the current measuring unit 3 and the voltage measuring unit 4, and then analog-to-digital conversion is performed. The processing unit 6 is electrically connected to the analog-to-digital converting unit group 5 and includes a computing module. Group 61, when the computing module 61 receives the digital current function and the digital voltage function, 'converts the digital current function and the digital voltage function 丄 325496 The operation is performed for the complex (c〇mplex) form. The reason for using the complex operation is that the welding process produces an inductive effect, so the voltage phase leads the current phase, so the electrical impedance function of the weldment to be tested cannot be directly divided by the voltage. The current is calculated. The complex current function generated by the operation module 61 is calculated according to the formula (1): .......................... ..... redundant t a...................I丄)

Wherein, the function is the complex current, the function is the digital current function and is the real part of the complex current function, and the digital current function is substituted into a Hilbert Transf〇rm equation The imaginary part of the complex current function obtained by the difference is imaginary. The complex current function can be expressed by the formula (2) after being calculated by the formula (1): ~)=|/(〇卜_).................... .... where 'the φ 2 is the relative phase.

The complex voltage function generated by the operation module 61 is calculated according to the formula (7): π} t-t' ......................... ..................... where f (〇 is the complex voltage function, the <〇 is the function of the digital voltage and is the function of the complex voltage And the ^ is the imaginary part of the complex voltage function obtained by substituting the digital voltage function into the Hilbert conversion equation, and _/ is an imaginary unit. The complex voltage function is calculated by the above formula 10 . ···(4) After the calculation, it can be expressed by the formula (4): V(0 = |v(i)|eM(wherein, the P 1 is a relative phase - 1Φ to obtain the complex current function and the complex number After the voltage function, it can be 4 - the resistance 枋孑 1 1 j leaf ζ ζ (,) 而 而 and the electrical impedance function is calculated according to the formula (5): ' > ~)] phase μ-..... ................................ I , . . , 丨 z(t) 丨 represents the amplitude of the electrical impedance, The relative phase between the two systems is two: after the electrical impedance function is obtained, the resistance of the electrical impedance function can be used as the vertical axis impedance waveform.兀7 Electrically connecting the processing unit 6' to display the electrical resistance.... Because the resistance of the weldment without the weld bead and the weldment with the weld bead, the waveform is different, the tester can understand the test piece according to the electrical impedance waveform 1 Whether the peak is actually welded. , m 2 'The method for detecting the weld bead defect of the first preferred embodiment of the present invention is applicable to the above test system for weld bead defect detection, and includes the following steps: First, as in step 9 As shown in FIG. 1 , after the welding, the welding consumables are electrically connected to the electrodes 21 of the test platform unit 2 and continuously connected to the alternating current. At this time, the current measuring unit 3 and the voltage measuring unit 4 can be utilized. The knife does not measure the analog current signal and the analog voltage signal between the electrodes 21 within a predetermined time. 11 Next, if the step 902 %· + 2 is not used, the analog to current group 5 is used to convert the analog current signal.兀

Function and the digital voltage function. The electric "L connector" is as shown in step 903, and the processing unit is based on the above equations (1) and (the number (four) stream function (four) modulus·= function, and according to the above equation (7) and equation (electric claw complex electric function). And the "digital voltage function is converted to the then, as shown in step _, the processing module of the processing unit 6 将该 the complex voltage according to the above equation (5) the electrical impedance function. Divided by the complex current function to obtain the receiver Step 9〇5, the operation module 61 of the processing unit 6 converts the electrical impedance function into an electrical impedance waveform 'and displays the electrical impedance waveform by the output unit 7', and the detecting person can know the electrical impedance waveform according to the electrical impedance waveform. Whether the weldment 1 to be tested has a problem of weld bead defects. Referring to Figure 3, a second preferred embodiment of the test system for weld bead defect detection of the present invention, like the first preferred embodiment, also includes a test platform unit 2 Current measuring unit 3 ... voltage measuring unit 4 - analog to digital converting unit group 5, processing unit 6 and - output unit 7. Unlike the first preferred embodiment, the second preferred embodiment Weld defect test system Furthermore, a pass band filter (Band Pass Fiher) 53 and a display unit 8 are included, and the processing unit 6 further includes an _analysis module 62 in addition to a computing fish 61. The passband filter 53 electrically connects the analog to digital conversion. Between the unit group 5 and the processing unit 6, the passband filter 53 is used to increase the detected precision 12 1325496 method for the test system of the bead defect detection of the second preferred embodiment, and includes the following steps: As shown in step 911, the soldering member 1 to be tested is electrically connected to the electrodes 21 of the measuring flat unit 2, and the power module 22 continuously passes the parent current. At this time, the current amount can be utilized. The measuring unit 3 and the voltage measuring unit 4 respectively measure the analog current signal and the analog voltage signal between the electrodes 21 within the predetermined time. Then, as shown in step 912, the analog to digital conversion unit group 5 is used to convert the The analog current signal and the analog voltage signal are a function of the digital current and the digital voltage function. Next, as shown in step 913, the digital current function and the digital voltage function are processed by the passband filter 53. High resonance. Next, as shown in step 914, the operation module 61 of the processing unit 6 is the same as the first preferred embodiment, converting the digital current function into the complex current function, and converting the digital voltage function into the The complex voltage function. Then, as shown in step 915, the operation module 61 of the processing unit 6 divides the complex voltage function by the complex current function to obtain the electrical impedance function. Then, as shown in step 916, the processing unit The operation module 61 of 6 converts the electrical impedance function into an electrical impedance waveform, and displays the electrical impedance waveform by using the output unit 7. Then, as shown in step 917, the analyzing unit 62 of the processing unit 6 compares the electrical impedance function with The historical electrical impedance functions are aligned, and in the display, the electrical impedance function is consistent with any historical electrical impedance function 14 1325496. The analysis unit 62 can use the database to establish the historical electrical impedance functions. The analysis unit 62 can also be used to enhance the ability of the analysis unit 62 to analyze the neural network identification map. The tester can make a correct judgment based on the results displayed by the output unit 7 and the member display unit 8, and even if the test experience is shallower, it can effectively assist the judgment. As described above, the present invention utilizes a complex calculation to avoid the problem of phase difference caused by measuring dynamic resistance. [In addition, the design of the present invention is directed to a weldment that has been successfully completed, so that a non-discharge process can be detected. The resulting defects can effectively improve the accuracy of detecting weld bead defects. Furthermore, in combination with the function of the analysis module 62 in the second preferred embodiment, it is possible to assist an operator without extensive test experience to make an accurate judgment. The above is only the preferred embodiment of the present invention, and is not intended to limit the scope of the practice of the present invention, that is, the simple equivalent change of the scope of the invention and the description of the invention. Modifications are still within the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a first embodiment of a test system for flaw detection of a bead of the present invention; FIG. 2 is a flow chart illustrating a method for detecting a defect of a bead of the present invention. a preferred embodiment; FIG. 3 is a block diagram showing a second preferred embodiment of the test system for bead defect detection of the present invention; and FIG. 4 is a flow chart illustrating a method for detecting a weld bead defect of the present invention. A first preferred embodiment. 15 1325496 [Explanation of main component symbols] 1 ·· ...welding of weldments 2 ..........test platform unit 21.........electrode 22··· ...power module 3 ...· ...... current measuring unit 4 ···· ... voltage measuring unit 5 ···· ... analog to digital conversion unit group 51... ...... current analog to digital converter 52-.. ...voltage analog to digital converter 53 .......... passband filter 6 ..... processing unit 61 ... ... computing module 62 .. .......analysis module 7 ..........output unit 8 .......... display unit 901~905 steps 911~917

16

Claims (1)

1325496 X. Patent application scope: 1 · A method for detecting weld bead defects, comprising the following steps: (a) After welding, a weldment to be tested electrically connected to the two electrodes is continuously connected to an alternating current, and the electrodes are measured (b) converting the analog current signal and the analog voltage signal to a digital current function and a digital voltage function respectively; (c) the digital current function is converted between the analog current signal and the analog voltage signal; And the digital voltage function is respectively converted into a complex current function and a complex voltage function, wherein the complex current function and the complex voltage function respectively comprise a real part and an imaginary part calculated by a Hilbert conversion equation; (d) Dividing the complex voltage function by the complex current function to obtain an electrical impedance function; and (e) converting the electrical impedance function into an electrical impedance waveform to display a weld bead defect of the weldment to be tested. 2. According to the method for detecting weld bead defects according to the scope of the patent application, in the steps (b) and (c), a step (f) is further included, and the digital current function is processed by a passband filter. And the higher resonance of the digital voltage function. 3. According to the method for detecting the flaw of the weld bead according to item i of the patent application scope, after the step (e), a step (g) is further included, and the historical electrical impedance function is pre-stored with respect to the electrical impedance resistance function and the complex number. And show whether the electrical impedance function matches any historical electrical impedance function. 4. According to the method for detecting weld bead defects according to item 3 of the patent application scope, 17 wherein the historical electrical impedance resistance functions include a normal electrical impedance resistance function of the double-barbar and a complex electrical impedance function of the complex mark for different reasons. 5. According to the method of detecting the defects of the weld bead as described in Shen Yiqing's patent scope No. 3, +. Λ μ Gudi 3, after the step (e), it is further included - 3 step (h), the electricity The impedance function is stored as one of the historical electrical impedance functions. 6. According to the method of flaw detection of the weld bead mentioned in the scope of the patent application, after the "(4) step", a step (1) is further included, and the electrical impedance function and a neural network trained by the complex historical electrical impedance function are included. The analysis module built by the identification map is analyzed and the analysis result is displayed. 7. The test system for the detection of the weld bead is suitable for analyzing a test piece to be tested, and comprises: a test platform unit, comprising two electrical connections An electrode at both ends of the fresh track of the weldment to be tested and a power module electrically connected to the electrodes and providing an AC power source, the power module is configured to continuously apply an alternating current to the weldment to be tested after the zinc is connected; a measuring unit electrically connected to the test platform unit and configured to measure an analog current signal between the electrodes within a predetermined time; a voltage measuring unit electrically connected to the test platform unit and configured to measure the predetermined time An analog voltage signal between the electrodes; a analog to digital conversion unit group electrically connected to the current measuring unit and the voltage measuring unit, and the analog current signal and The analog voltage signal is converted into a digital current function and a digital voltage function respectively; a processing unit is electrically connected to the analog to digital conversion unit group, and includes a computing module, wherein the computing module is configured to use the digital current function 18 The 1325496 number and the digital voltage function fractional tool are converted into a complex current function and a complex voltage function, and the -resistance function and the electrical impedance waveform are calculated, - "the complex motor function and the complex voltage function respectively include - And the imaginary part calculated by the Hilbert conversion equation; and an output unit electrically connected to the processing unit for displaying the electrical impedance waveform. 8. Test system for bead defect detection according to item 7 of the patent application scope: 'The analog-to-digital conversion unit group includes an analog-to-digital current conversion unit electrically connected to the current measurement unit and an electrical connection The voltage measurement unit is analogous to a digital voltage conversion unit. 9. According to the test system of the fresh track defect detection described in the Japanese Patent Application 帛7, the passband filter is connected to the analog-to-digital conversion unit group and the processing unit, The digital current function and the higher resonance of the digital voltage function are processed. 10. The test system for bead defect detection according to claim 7, wherein the processing unit further comprises an analysis module, wherein the analysis module records a plurality of pre-stored historical electrical impedance functions, and can analyze the Whether the electrical impedance function conforms to any historical electrical impedance function. 11. The test system for weld bead defect detection according to claim 10, wherein the historical electrical impedance function recorded by the analysis module of the processing unit includes a normal electrical impedance function and a complex mark for different reasons. Abnormal electrical impedance function. 1 2. The test system for bead defect detection described in item 1 of the patent application scope further includes a display unit for displaying whether the electrical impedance function is 19 1325496 or any historical electrical impedance function β 13· The testing system for the bead defect detection described in the patent scope 1Q, wherein the processing module of the processing unit can store the electrical impedance function as one of the historical electrical impedance functions. 14. The test system for knowing the defect detection according to item 7 of the scope of the patent application, wherein the processing unit further comprises a gong ', a knife 杈 group, the analysis module uses a complex historical electrical impedance function 钏 green The number of arsenic is established by the network identification diagram and used to analyze the electrical impedance function. 15. The test system for the detection of weld bead defects according to item 34 of the scope of the patent application s 4 further includes a display unit, the base dd — / · ', is not used to display the analysis module after analysis Analysis results. 20