CN107505059A - A kind of welding process detection device and welding parameter acquisition method - Google Patents

Abstract

The invention relates to a welding process detection device and a welding parameter collection method. The detection device includes a welding machine, a collection system and a host computer, wherein the welding machine and the collection system are respectively connected to the host computer. The parameter collection method includes 5 steps. After adopting the invention, the electric signal and temperature field signal in the welding process can be collected and stored in real time, and the temperature can be collected in a wide range from -200°C to 1300°C, and can withstand 3000v TIG high-voltage arcing without damage. The data obtained by adopting the present invention can be analyzed in the upper computer software of the computer. The analysis of welding voltage and current includes average voltage, average current, voltage waveform diagram, current waveform diagram, voltage and current waveform diagram, voltage density distribution curve, and current density distribution. curve. Signal analysis of temperature field includes 8-channel temperature field curve, maximum temperature, minimum temperature, average temperature, temperature change speed, T85 time, T83 time of each channel.

Description

A welding process detection device and welding parameter collection method

technical field

The invention relates to the field of welding technology, in particular to a device and technology suitable for synchronously collecting welding voltage, current, and temperature field signals during the welding process, specifically a welding process detection device and a welding parameter collection method.

Background technique

In the previous welding procedure qualification process, only attention was paid to the shape, structure, metallographic, mechanical properties and other data of the welded joint, and the electrical signal and temperature field signal during the welding process were basically ignored. This leads to some joints with poor process performance and cannot find out the reason. The electric signal is the most direct energy output mode of the welding machine during the welding process. This signal can reflect the working performance of the welding machine and the welding method adopted. Under the same heat input, different electrical signal waveforms will have a significant impact on the shape, structure, metallographic and mechanical properties of the joint. The forming of the joint is melting at high temperature and then cooling to form. The temperature field signal can most directly reflect the heating state of the workpiece. Therefore, we invented a system that can collect the voltage, current, and temperature field signals in the welding process synchronously. With these data, we can find out the waveform of the welding electrical signal of a certain joint and the thermal cycle curve of the temperature field. Using these data, we can analyze the forming, structure, metallographic and mechanical properties of the joint from different angles, and different angles The analysis results should be mutually corroborated. Such an analysis method will be more scientific, more comprehensive, more accurate and easier to find the problem than the previous method, which will greatly promote the development of modern welding procedure qualification.

Contents of the invention

The equipment provided by the invention can collect and store electrical signals and temperature field signals in the welding process in real time, and can collect temperature in a wide range from -200°C to 1300°C, and can withstand 3000v TIG high-voltage arcing without damage. The data obtained by adopting the present invention can be analyzed in the upper computer software of the computer. The analysis of welding voltage and current includes average voltage, average current, voltage waveform diagram, current waveform diagram, voltage and current waveform diagram, voltage density distribution curve, and current density distribution. curve. Signal analysis of temperature field includes 8-channel temperature field curve, maximum temperature, minimum temperature, average temperature, temperature change speed, T85 time, T83 time of each channel. The present invention is specifically as follows:

A welding device includes a welding machine, an acquisition system and a host computer, wherein the welder and the acquisition system are respectively connected to the host computer, and the synchronous acquisition system includes a voltage acquisition unit, a current acquisition unit, and a temperature field acquisition unit. in,

The voltage acquisition unit is responsible for collecting the welding voltage signal, and conditioning the voltage signal of ±200v to ±10v. And it can withstand TIG's 3000v high voltage arcing without being damaged.

The current collection unit is responsible for collecting welding current signals, and conditioning the ±1000A current signals to ±10v.

The temperature field collection unit is responsible for collecting the temperature of the workpiece, and the temperature measurement range is -200°C to 1300°C.

Furthermore, the temperature field acquisition unit consists of a thermocouple sub-module 1, a first signal conditioning sub-module 2, a first ARM chip 3, a second ARM chip 4, a touch screen 5, a button sub-module 6, a second signal conditioning sub-module 7, AD conversion module 8 and SD card module 9. in,

The thermocouple sub-module 1 is connected to the first ARM chip 3 through the first signal conditioning sub-module 2 .

The output end of the second signal conditioning sub-module 7 is connected to the input end of the AD conversion module 8 .

The first ARM chip 3 , the touch screen 5 , the AD conversion module 8 and the SD card module 9 are respectively connected to the second ARM chip 4 for two-way data communication.

The button sub-module 6 is connected with the second ARM chip 4 for unidirectional data communication.

Adopt the welding control method of a kind of welding equipment of the present invention, carry out according to the following steps:

Step 1: Use a drill to punch holes in the plates to be welded. Subsequently, a thermocouple is inserted into the hole. The thermocouple is then secured by inserting welding wire into the hole in which the thermocouple is inserted.

Step 2: Connect the positive and negative poles of the voltage acquisition line to the corresponding positive and negative pole outputs of the plate to be welded.

Step 3: Pass the ground wire through the Hall current sensor according to the current direction.

Step 4:

After completing the above wiring work, turn on the power and fit the temperature according to the following function:

y=ax+b,

Wherein, the value range of a is between 0.010 and 0.500, and the value range of b is between 0.800 and 400.1000.

Step 5: Store the above fitting temperature to the SD card and display it on the 7-inch LCD screen.

Step 6: Use the host computer software to analyze the electrical signal and temperature field data of the SD card, and evaluate the welding process.

Beneficial technical effect

Some traditional thermocouple temperature acquisition circuits are completed using analog circuits, and some are implemented using dedicated chips. The former has the disadvantages of complex circuit, large error and narrow temperature measurement range, while the latter has the disadvantages of high price and narrow temperature measurement range. However, the present invention can overcome the problems of electromagnetic interference in the welding process and bad working environment.

The temperature measuring range of the present invention is particularly wide -200°C-1000°C. When there is a post-weld surface cooling process, there will be negative temperatures. The invention overcomes the problem that the traditional methods (the above two solutions) are difficult to meet the use requirements.

The invention can directly collect the electrical signals of various welding machines. The sampling of electrical signals can reach 8 channels, and the sampling rate of each channel can reach 200KHZ. It can withstand the high voltage and high frequency arc ignition of TIG. The temperature field can measure the temperature from -200℃ to 1300℃. All data can be saved in real time. All data can be automatically analyzed on the software of the host computer. In addition, the present invention also has the following characteristics:

1. Wide temperature range -200℃-1300℃.

2. Good anti-interference performance, can collect temperature signals of various welding equipment.

3. Simple circuit, digital temperature acquisition.

4. The temperature data transmission is convenient, which can be can, wireless or other methods.

5. The control chip of the present invention adopts a cost-effective ARM chip-STM32F429VGT6, and its built-in 1MB flash memory and 256KB SRAM such a super large storage space can satisfy the use of the UCOS-III real-time operating system to complete all control and acquisition tasks. Displayed on a 7-inch LCD screen, the LCD screen is connected to the ARM chip through the FSMC bus, and the graphical interface display is developed based on the STemWin graphical interface system. All data is stored in the SD card, and the SD card is connected to the ARM through the SDIO interface, and the operation of the SD card uses the FatFS file system. The STM32F429 series adopts the latest 180MHz ARM Cortex-M4 processor core, and its speed can meet our high-speed data acquisition requirements. The collected data can also be transmitted to other devices through wireless or network ports. The wireless communication protocol adopts the MODBUS protocol, and the communication protocol of the network port uses the lwip protocol stack.

6. Most of the welding electrical signals are in the range of ±200v/±1000A. In order to collect the electrical signals, we adjust them to the range of ±10v, and then connect them to the AD7606 analog-to-digital conversion chip, which is connected to the ARM through the INTER8086 interface. on chip. The data sampling rate of AD7606 can reach 8 channels, each channel is 200KHZ.

7. The temperature is collected by a thermocouple, and the potential caused by the temperature difference is conditioned and then connected to the ADC interface of the STM32F373. High-precision temperature measurement can be achieved using the chip's 16-bit sigma-delta ADC. When using a k-type thermocouple, the temperature measurement range can reach -200°C--1300°C. STM32F373 can be used independently as a temperature field acquisition module. The temperature data can be transmitted to the STM32F429VGT6 chip through wireless or CAN communication, and then stored in the SD card.

8. The data in the SD card can be analyzed in the upper computer software of the computer. The data of the temperature field can see the thermal cycle curve, the highest problem of each channel, the duration of high temperature, and the temperature change rate. For electrical signals, you can see the waveform of the electrical signal, the average value, standard deviation, coefficient of variation, and instantaneous power of the electrical signal.

To sum up, the present invention is specially developed for the field of welding, and can withstand the interference of high-voltage and high-frequency arc ignition during welding. When the welding speed is determined, the system can also measure the heat input during welding. The electrical signal channel can reach 8 channels, which can measure the power source of various hybrid welding. The temperature can be measured to -200°C. The electrical signal and temperature field of welding are closely related to the process performance of the welded joint, and the problem can be analyzed from multiple angles. The system has been used in many occasions, small size, easy to use, stable system.

Description of drawings

Fig. 1 is a structural block diagram of the present invention.

detailed description

The present invention will be further described in detail with reference to the accompanying drawings and embodiments.

A welding process detection device, including a welding machine, an acquisition system, and a host computer, wherein the welding machine and the acquisition system are respectively connected to the host computer, and is characterized in that the synchronous acquisition system includes a voltage acquisition unit, a current acquisition unit, and a temperature field acquisition unit. unit. in,

The voltage acquisition unit is responsible for collecting the welding voltage signal, and conditioning the voltage signal of ±200v to ±10v. And it can withstand TIG's 3000v high voltage arcing without being damaged.

The current collection unit is responsible for collecting welding current signals, and conditioning the ±1000A current signals to +10v.

The temperature field collection unit is responsible for collecting the temperature of the workpiece, and the temperature measurement range is -200°C to 1300°C.

Furthermore, the temperature field acquisition unit contains 8-channel thermocouples to detect the ambient temperature from -200°C to 1300°C. The sampling voltage range of the voltage acquisition unit is between -200V and 200V. The sampling current range of the current acquisition unit is between -1000A and 1000A.

Referring to Fig. 1, further, the temperature field acquisition unit is composed of a thermocouple sub-module 1, a first signal conditioning sub-module 2, a first ARM chip 3, a second ARM chip 4, a touch screen 5, a button sub-module 6, a second signal conditioning Submodule 7, AD conversion module 8 and SD card module 9. Wherein, the thermocouple sub-module 1 is connected to the first ARM chip 3 through the first signal conditioning sub-module 2 . The output end of the second signal conditioning sub-module 7 is connected to the input end of the AD conversion module 8 . The first ARM chip 3 , the touch screen 5 , the AD conversion module 8 and the SD card module 9 are respectively connected to the second ARM chip 4 for two-way data communication. The button sub-module 6 is connected with the second ARM chip 4 for unidirectional data communication.

Furthermore, the thermocouple sub-module 1 contains no less than 8 channels. The thermocouple sub-module 1 is a K-type thermocouple. The temperature measuring range of the thermocouple module 1 is between -200°C and 1300°C. The model of the first ARM chip 3 is STM32F373. The model of the second ARM chip 4 is STM32F429. The first signal conditioning sub-module 2 is responsible for eliminating the interference and noise signals on the thermocouple and isolating and outputting the thermoelectric potential signal to the ARM chip. The input and output range of the thermoelectric potential is ±1v. The second signal conditioning sub-module 7 is responsible for considering the interference and noise signals during the welding process and conditioning the received welding voltage and current signals to the range of -10V to +10V. The model of AD conversion module 8 is AD7606 analog-to-digital conversion chip. The data sampling rate of the AD conversion module 8 is not less than 8 channels, and each channel is 200KHZ.

Referring to FIG. 1 , further speaking, the first ARM chip 3 and the second ARM chip 4 are connected by wireless connection or CAN cable. The touch screen 5 is connected with the second ARM chip 4 through FSMC. The button sub-module 6 is connected to the second ARM chip 4 through I/O. The AD conversion module 8 is connected with the second ARM chip 4 through INTER8086.

Referring to FIG. 1 , further speaking, the receiving end of the second signal conditioning sub-module 7 is connected to the welding electrical signal interface 10 .

Referring to FIG. 1 , further speaking, the output terminals of the voltage acquisition unit and the output terminal of the current acquisition unit are respectively connected to the welding electrical signal interface 10 .

Adopt the welding parameter collection method of a kind of welding process detection equipment of the present invention, carry out according to the following steps:

Step 1: Use a drill to punch holes in the plates to be welded. Subsequently, a thermocouple is inserted into the hole. The thermocouple is then secured by inserting welding wire into the hole in which the thermocouple is inserted. Step 2: Connect the positive and negative poles of the voltage acquisition line to the corresponding positive and negative pole outputs of the plate to be welded. Step 3: Pass the ground wire through the Hall current sensor according to the current direction. Step 4: After completing the above wiring work, turn on the power and fit the temperature according to the following function:

y=ax+b,

Wherein, the value range of a is between 0.010 and 0.500, and the value range of b is between 0.800 and 400.1000.

Step 5: Store the above fitting temperature to the SD card and display it on the 7-inch LCD screen.

Step 6: Use the host computer software to analyze the electrical signal and temperature field data of the SD card, and evaluate the welding process.

Furthermore, using a welding parameter acquisition method of welding process detection equipment, in different temperature ranges, the values of a and b are specifically as follows:

Temperature detected by thermocouple sub-module 1 a b Linearity -250℃～-200℃ 0.0956 367.24 0.9838 -199℃～100℃ 0.0424 55.768 0.9930 -99℃～-50℃ 0.0301 7.4615 0.9996 -49℃～0℃ 0.0265 0.4084 0.9998 1°C-100°C 0.0243 0.5317 1.0000 101°C-200°C 0.0248 -1.8988 1.0000 201℃-400℃ 0.0242 4.2684 0.9990 401℃-600℃ 0.0235 15.057 1.0000 601℃-800℃ 0.0239 4.5397 1.0000 801°C-1000°C 0.0250 -32.73 1.0000 1001°C-1300°C 0.0250 -32.73 0.9998

In the above fitting function, y is temperature in °C, and x is thermoelectric potential in uV. Compared with the graduated table, the function after segment fitting has only a maximum error of ±3°C.

The thermoelectric potential is collected through the differential ADC, and then the corresponding temperature is calculated through the fitting function to complete the temperature collection.

Linearity is the degree of deviation between the fitted function and the actual graduated table. Use continuous functions to represent discrete points. The higher the linearity, the smaller the error between the fitted function and the discrete point. It can be seen from the above table that the temperature error between the temperature obtained after adopting the equipment and method of the present invention and the actual temperature is small.

Claims (9)

1. The utility model provides a welding process check out test set, includes welding machine, collection system and host computer, wherein, welding machine and collection system are connected with the host computer respectively, its characterized in that: the synchronous acquisition system comprises a voltage acquisition unit, a current acquisition unit and a temperature field acquisition unit; the voltage acquisition unit is responsible for acquiring a welding voltage signal, conditioning a voltage signal of +/-200 v to +/-10 v, and bearing 3000v high-voltage arcing of TIG without being damaged; the current acquisition unit is responsible for acquiring welding current signals, and conditioning the current signals of +/-1000A to +/-10 v; the temperature field acquisition unit is responsible for acquiring the temperature of the workpiece, and the temperature measurement range is-200 ℃ to 1300 ℃.

2. The welding process detection device of claim 1, wherein: the temperature field acquisition unit comprises an 8-channel thermocouple and is used for detecting the ambient temperature of-200 ℃ to 1300 ℃; the sampling voltage range of the voltage acquisition unit is between-200V and 200V; the sampling current range of the current acquisition unit is between-1000A and 1000A.

3. The welding process detection device of claim 1, wherein: the temperature field acquisition unit consists of a thermocouple sub-module (1), a first signal conditioning sub-module (2), a first ARM chip (3), a second ARM chip (4), a touch screen (5), a key sub-module (6), a second signal conditioning sub-module (7), an AD conversion module (8) and an SD card module (9); the thermocouple submodule (1) is connected with the first ARM chip (3) through the first signal conditioning submodule (2); the output end of the second signal conditioning submodule (7) is connected with the input end of the AD conversion module (8); the first ARM chip (3), the touch screen (5), the AD conversion module (8) and the SD card module (9) are respectively connected with the second ARM chip (4) and are in bidirectional data communication; the key submodule (6) is connected with the second ARM chip (4) and is in one-way data communication.

4. A welding process detection apparatus according to claim 3, wherein: the thermocouple submodule (1) comprises not less than 8 channels; the thermocouple sub-module (1) is a K-type thermocouple; the temperature measuring range of the thermocouple sub-module (1) is between-200 ℃ and 1300 ℃; the model of the first ARM chip (3) is STM32F 373; the model of the second ARM chip (4) is STM32F 429; the first signal conditioning submodule (2) is responsible for filtering interference and noise signals on the thermocouple and isolating and outputting thermoelectric potential signals to the ARM chip, and the input and output range of thermoelectric potential is +/-1 v; the second signal conditioning submodule (7) is responsible for filtering interference and noise signals in the welding process and conditioning received welding voltage and current signals to a range from-10V to + 10V; the model of the AD conversion module (8) is an AD7606 analog-to-digital conversion chip; the data sampling rate of the AD conversion module (8) is not less than 8 channels, and each channel has 200 KHZ.

5. A welding process detection apparatus according to claim 3, wherein: the first ARM chip (3) is connected with the second ARM chip (4) in a wireless connection mode or a CAN wired mode; the touch screen (5) is connected with the second ARM chip (4) through the FSMC; the key submodule (6) is connected with the second ARM chip (4) through I/O; the AD conversion module (8) is connected with the second ARM chip (4) through an INTER 8086.

6. A welding process detection apparatus according to claim 3, wherein: the receiving end of the second signal conditioning submodule (7) is connected with the welding electric signal interface (10).

7. The welding process detection device of claim 6, wherein: the output end of the voltage acquisition unit and the output end of the current acquisition unit are respectively connected with the welding electric signal interface (10).

8. A welding parameter acquisition method using a welding process detection apparatus according to claims 1 to 7, characterized in that: the method comprises the following steps:

step 1: punching a hole on a plate to be welded by using a drill bit; subsequently, a thermocouple was inserted into the hole; then, a welding wire is plugged into the hole in which the thermocouple is inserted, so that the thermocouple is fixed;

step 2: welding the positive and negative electrodes of the voltage acquisition line to the corresponding positive and negative electrode outputs of the plate to be welded;

and step 3: the ground wire penetrates through the Hall current sensor according to the current direction;

and 4, step 4: after the wiring work is finished, starting the machine and fitting the temperature according to the following functional formula:

y＝ax+b，

wherein, the value range of a is between 0.010 and 0.500, and the value range of b is between 0.800 and 400.1000.

And 5: and outputting the fitting temperature.

9. The method of claim 8 for collecting welding parameters using a welding process sensing device, wherein the method comprises the steps of: in different temperature ranges, the values of a and b are specifically as follows: