TWI718627B - Method of detecting material surface defects with surface wave frequency - Google Patents

Abstract

A method for detecting material surface defects at the frequency of surface waves includes the following steps: making a surface wave pass through a material surface of a material that is smooth and flawless and a material surface of a material to be tested, the material and the material to be tested. The test material moves from a transmitting end of the surface wave toward a receiving end of the surface wave at a transmission rate, and a processing module obtains the predetermined frequency and the predetermined frequency of the surface wave passing through the surface of the material from the Doppler effect relationship The surface wave passes through a detection frequency on the surface of the material to be tested; the processing module compares the predetermined frequency with the detection frequency, and when the predetermined frequency does not match the detection frequency, the processing module determines the material to be measured The surface of the material to be tested is flawed. In this way, a low-cost, convenient and continuous detection method for material surface defects is provided.

Description

Method for detecting material surface defects with surface wave frequency

The invention relates to a method for detecting material defects, in particular to a method for detecting material surface defects using surface wave frequencies.

In the process, if there are cracks on the surface of the material, in addition to reducing the strength of the material itself, the cracks may damage the material as the stress applied by the process increases. Therefore, there are various inspection methods in the industry to conduct rapid product defect detection to improve the process effectiveness.

Among different detection methods, non-destructive detection method is a common detection method. Specifically, the Republic of China Patent Certificate No. I480539 provides a defect detection device and method for light-transmitting materials, which are located above and below the traveling film. The first and second polarizers are arranged in a crossed Nicol pattern. The light is irradiated on the film by the light projector through the first polarizing plate, and the light emitted from the second polarizing plate is detected by the light receiver, and the defect of the film is detected. A band pass filter is provided between the first polarizing plate and the light projector. The band pass filter removes the light from the light projector that has a wavelength range of 420 nm or less and 700 nm or more. Since the light in the unnecessary wavelength region does not enter the light receiver, the accuracy of detecting defects can be improved.

There is also a technology that uses the time difference between the ultrasonic wave to pass the flaw and the non-defect to detect the depth of the flaw. The aforementioned time difference is often in the order of nanoseconds. To detect such an accurate time difference requires extremely sophisticated and expensive instruments, and other current non-destructive The equipment required for sexual testing, such as sorting machines, indexing plate screening machines, optical image screening machines, etc., are also expensive and cannot be popularized in traditional Manufacturer; there is also a hand-held material detector. Although the price is relatively low, it cannot be continuously tested, and there are still many inconveniences in use.

計算得到該表面波通過該材料表面之一預設頻率；B.再使該表面波通過一待測材料的一待測材料表面，該待測材料以相同的該輸送速率自該發射端朝該接收端移動，該處理模組依據都卜勒效應關係式計算得到該表面波通過該待測材料表面之一檢測頻率；C.該處理模組比對該預設頻率及該檢測頻率，當該預設頻率與該檢測頻率不相符時，該處理模組判斷該待測材料的該待測材料表面有瑕疵；D.一儲存模組儲存複數之該檢測頻率，該處理模組由該預設頻率及複數之該檢測頻率分析得到一良率。 In this regard, in order to effectively improve the process efficiency, the inventor proposes a method for detecting material surface defects with a surface wave frequency, which includes the following steps: A. A surface wave passes through a surface of a material that is smooth and flawless. From a transmitting end of the surface wave to a receiving end of the surface wave at a transmission rate, a processing module is based on the Doppler effect relationship

It is calculated that the surface wave passes through a predetermined frequency of the material surface; B. The surface wave is then passed through a material surface of a material to be tested, and the material to be tested is transferred from the transmitting end toward the When the receiving end moves, the processing module calculates the detection frequency of the surface wave passing through the surface of the material to be measured according to the Doppler effect relation; C. The processing module compares the preset frequency with the detection frequency, when the When the preset frequency does not match the detection frequency, the processing module determines that the surface of the material to be tested is flawed; D. A storage module stores a plurality of the detection frequencies, and the processing module is determined by the preset The frequency and the detection frequency of the plural number are analyzed to obtain a yield rate.

Wherein, the frequency of the surface wave and the transmission rate are controlled by the processing module.

Wherein, the material is conveyed from the transmitting end to the receiving end along with a conveyor belt at the conveying rate.

Among them, the surface wave system is ultrasonic.

According to the above technical features, the following effects can be achieved:

1. Detect the surface defects of the material to be tested with high-resolution and low-cost surface wave frequency, saving the high cost of other precision instruments for non-destructive testing.

2. The material to be tested moves with the conveyor belt, and the defect detection can be completed after passing through the transmitting end and the receiving end, which is convenient and can be continuously measured.

3. The processing module obtains the yield rate by analyzing the multiple detection frequencies stored in the storage module, which is convenient for the factory to repair or upgrade the manufacturing equipment based on the yield rate to ensure the quality of the materials to be tested.

4. The processing module controls the transmission frequency and transmission rate of the surface wave, and can select the appropriate surface wave frequency and transmission rate according to different materials, and does not require manual operation.

1: Processing module

2: Transmitter

3: receiving end

4: Conveyor belt

5: Notification module

6: Storage module

A: Material

B: Material to be tested

S1: Preliminary steps

S2: Detection steps

S3: Comparison steps

S4: Analysis step

[The first figure] is a system block diagram of an embodiment of the present invention.

[The second figure] is a schematic flow diagram of an embodiment of the present invention.

[The third figure] is the first schematic diagram of the embodiment of the present invention, showing the use of smooth and flawless materials.

[Fourth figure] is the second schematic diagram of the embodiment of the present invention, showing the use of the material to be tested.

Combining the above technical features, the main effect of the method of detecting material surface defects by using surface wave frequencies of the present invention will be clearly demonstrated in the following embodiments.

Please refer to the first figure, which is a system that implements the method of detecting material surface defects at a surface wave frequency. The system includes a processing module (1), a transmitting terminal (2), and a receiving terminal (3). , A conveyor belt (4), a notification module (5) and a storage module (6).

The processing module (1) is signal connected to the transmitting terminal (2), the receiving terminal (3), the conveyor belt (4), the notification module (5) and the storage module (6), and the processing module (1) Control the transmission frequency of a surface wave emitted by the transmitter (2) and a transmission rate of the conveyor belt (4), in the adjustment of the manufacturing process or production speed When necessary, the transmission frequency and the transmission rate of the surface wave can be selected appropriately according to different materials, without a user's own operation and setting.

The transmitting terminal (2) and the receiving terminal (3) respectively transmit and receive the surface wave, and the surface wave system is an ultrasonic wave. The notification module (5) can be a display, an alarm, or a voice player, etc. For example, when the processing module (1) determines that a material to be tested (B) is defective, the notification module (5) can borrow The user is notified that the material to be tested (B) is defective by means of screen, ringing or voice. The storage module (6) can be a virtual storage device such as a cloud server, or a physical storage device such as a hard disk and a flash drive.

Please refer to the first to fourth figures, the following will describe in detail the steps of the surface wave frequency method for detecting material surface defects:

計算得到該表面波通過該材料(A)之該材料表面的一預設頻率。 A pre-step (S1): as shown in the third figure, the transmitting end (2) emits the surface wave, so that the surface wave passes through a surface of a material (A) that is smooth and flawless, and the material (A) The transmitting end (2) of the surface wave moves with the conveyor belt (4) toward the receiving end (3) of the surface wave at the conveying rate, and the processing module (1) is based on the Doppler effect relationship

A preset frequency of the surface wave passing through the material surface of the material (A) is calculated.

，該處理模組(1)再據此計算該預設頻率。 In the Doppler effect equation, f _{o is} the preset frequency, and f _{s is} the frequency of the surface wave emitted by the transmitting end (2), which is the transmitting frequency. v is the wave speed of the surface wave traveling in the material (A), which varies according to different materials. Taking an isotropic material for example, the traveling speed of the longitudinal wave in medium carbon steel is 5923 meters per second. The travel speed of transverse waves in medium carbon steel is 3240 meters per second. v _{o is} the relative velocity of the receiving end (3). The transmitting end (2) and the receiving end (3) are turned on synchronously. When the transmitting end (2) sends the surface wave to the material (A), the The surface wave is transmitted along the surface of the material (A), and the material (A) is conveyed by the conveyor belt (4) at the conveying rate, so that the surface wave advances toward the receiving end (3), and the The receiving end (3) does not move, and v _o is 0. v _s is the rate of the material (A), that is, the conveying rate of the conveyor belt (4). For example, if the conveyor belt (4) is conveyed at the conveying rate of 1 cm per second, then v _s will also be every 1 cm per second. In the Doppler effect equation, the surface wave approaching the receiving end (3) is the operator. Based on the above, the Doppler effect equation can be rewritten as

, The processing module (1) then calculates the preset frequency accordingly.

A detection step (S2): as shown in the fourth figure, the transmitting end (2) then emits the surface wave, and the surface wave passes through the surface of a material to be tested of the material to be tested (B), and the material to be tested ( B) Move from the transmitting end (2) to the receiving end (3) at the same conveying rate as the material (A), and the processing module (1) then according to the Doppler effect relationship formula to compare with the previous Set the same calculation method in step (S1) to obtain a detection frequency of the surface wave passing through the surface of the material to be tested.

A comparison step (S3): the processing module (1) compares the preset frequency and the detection frequency, and when the preset frequency does not match the detection frequency, the processing module (1) determines the to-be-tested frequency The material (B) has a defect on the surface of the material to be tested, and the processing module (1) controls the notification module (5) to issue a warning. For example, if the notification module (5) is a siren, the warning is the alarm sound of the siren; if the notification module (5) is a display, the warning is the flashing of the display screen or on the display screen Displaying exclamation marks and other methods that can attract the user’s attention is convenient for the user to pick out the material to be tested (B) with defects, and to prevent the material to be tested (B) from being found to have defects after processing, which can improve production efficiency .

會小於該材料(A)之該預設頻率

，該處理模組(1)因此判斷該待測材料(B)為有瑕疵。 When there is a flaw on the surface of the material to be tested, it means that there are cracks or scars on the surface of the material to be tested, so that the surface wave cannot pass through the surface of the material to be tested directly along the original path and needs to pass through the cracks or scars. The time for the surface wave to reach the receiving end (3) through cracks or scars is longer than the time for the surface wave to reach the receiving end (3) through the surface of the material (A). For the surface wave, it is equivalent to _{The speed v p} on the test material (B) is slower _{than the speed v s} on the material (A), then the detection frequency of the test material (B)

Will be less than the preset frequency of the material (A)

Therefore, the processing module (1) determines that the material to be tested (B) is defective.

An analysis step (S4): the storage module (6) stores a plurality of the detection frequencies, the processing module (1) analyzes the preset frequency and the plurality of the detection frequencies to obtain a yield, the processing module ( 1) And control the notification module (5) to send a notification message. for example. If the notification module (5) is a display, the notification message can display the yield rate on the display screen; if the notification module (5) is a voice player, the notification message can be a display of the yield rate The voice is convenient for the user to perform maintenance or upgrade of related manufacturing equipment according to the yield rate to ensure the quality of the material to be tested (B).

After the material to be tested (B) moves with the conveyor belt (4) through the transmitting end (2) and the receiving end (3), and is compared by the processing module (1), the instant defect can be completed Detection. This method of detecting material defects with surface wave frequency is convenient, fast and can be continuously measured. Because the resolution of surface wave frequency detection equipment is higher than that of detection time, it also saves other non-destructive testing. The high cost required for precision instruments.

It should be particularly noted that not every test of the material to be tested (B) needs to start with the pre-step (S1) and end with the analysis step (S4). After performing the pre-step (S1) once, the preset frequency detected by the surface wave of the emission frequency of the material (A) at the delivery rate can be obtained, and then if the delivery rate and the emission frequency are maintained , As long as the material to be tested (B) is of the same material, the inspection can be started directly from the inspection step (S2) to speed up the inspection efficiency, and the comparison step (S3) can find out whether there are defects. When the same batch is produced After the material to be tested (B) is confirmed to be flawless, the analysis step (S4) can be used to confirm the yield of the material to be tested (B).

Based on the description of the above-mentioned embodiments, when the operation and use of the present invention and the effects of the present invention can be fully understood, the above-mentioned embodiments are only the preferred embodiments of the present invention. Therefore, the scope of implementation of the present invention is limited, that is, simple equivalent changes and modifications made according to the scope of patent application and description of the invention are all within the scope of the present invention.

S1: Preliminary steps

S2: Detection steps

S3: Comparison steps

S4: Analysis step

Claims (4)

A method for detecting material surface defects at the frequency of surface waves, including the following steps: A. Pass a surface wave through a surface of a material that is smooth and flawless, and the material is conveyed at a transmission rate from an emitting end of the surface wave toward One of the receiving end of the surface wave moves, and a processing module is based on the Doppler effect relationship

It is calculated that the surface wave passes through a predetermined frequency of the material surface; B. The surface wave is then passed through a material surface of a material to be tested, and the material to be tested is transferred from the transmitting end toward the When the receiving end moves, the processing module calculates the detection frequency of the surface wave passing through the surface of the material to be measured according to the Doppler effect relation; C. The processing module compares the preset frequency with the detection frequency, when the When the preset frequency does not match the detection frequency, the processing module determines that the surface of the material to be tested is flawed; D. A storage module stores a plurality of the detection frequencies, and the processing module is determined by the preset The frequency and the detection frequency of the plural number are analyzed to obtain a yield rate. The method for detecting surface defects of a material with a surface wave frequency as described in claim 1, wherein the frequency of the surface wave and the transmission rate are controlled by the processing module. The method for detecting surface defects of a material using a surface wave frequency as described in claim 1, wherein the material is conveyed from the transmitting end to the receiving end along a conveyor belt at the conveying rate. The method for detecting surface defects of a material using a surface wave frequency as described in claim 1, wherein the surface wave is ultrasonic.

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