Secondary current signal detection method for vacuum laser welding

Abstract

The invention discloses a secondary current signal detection method for vacuum laser welding, which comprises the following steps of: arranging a sheet copper plate as a secondary current collector in a vacuum chamber for vacuum laser welding; an amplification system is connected through an electric signal, and the collected secondary current signal is transmitted and amplified; and a signal display and analysis system is adopted to carry out digital processing on the digital secondary current signal and carry out on-line display and real-time analysis on the secondary current signal after digital processing. According to the invention, secondary current signals during vacuum laser welding can be collected in real time, and the secondary current signals can be subjected to signal processing, online display and real-time analysis; therefore, non-intrusive online monitoring of vacuum laser welding is realized by monitoring the secondary current signal.

Description

Technical Field

[0001] The invention relates to a secondary current signal detection method for vacuum laser welding. Background Art

[0002] Vacuum laser welding is a welding technology that uses a laser beam to heat, melt and connect workpieces with high energy density in a vacuum environment. It is used in the fields of automobile, aerospace and electronic equipment manufacturing. Its advantages include improved welding quality, deep welding and narrow welds, fast processing speed and small heat-affected zone, which can improve product quality, reliability and production efficiency.

[0003] Since it is difficult to intervene manually in the vacuum laser welding process, when process defects such as poor forming occur, it must be able to perform complete closed-loop automatic control. During vacuum laser welding, in the vacuum chamber, the metal material is irradiated by the laser, and a large number of free electrons are generated inside the metal vapor and plasma formed by the evaporation of the material. These free electrons are secondary electrons; the current formed by the secondary electrons is the secondary current; by monitoring the size of the secondary current, non-invasive online monitoring of vacuum laser welding can be achieved. Therefore, it is necessary to design a secondary current signal detection method that can be applied to real-time monitoring of vacuum laser welding. Summary of the invention

[0004] In order to solve the defects of the prior art, the present invention provides a secondary current signal detection method for vacuum laser welding, comprising:

[0005] A thin copper plate is placed in the vacuum chamber of the vacuum laser welding as a secondary current collector;

[0006] An electrical signal connection amplification system is used to transmit and amplify the collected secondary current signal;

[0007] The signal display and analysis system is used to digitally process the digital secondary current signal, and the digitally processed secondary current signal is displayed online and analyzed in real time.

[0008] Preferably, a thin copper plate is connected to the top of the welding plate, an electric potential difference is generated between the thin copper plate and the workpiece, and an external load resistor is connected to form a loop; the thin copper plate outputs the collected secondary current to the outside, generating a voltage drop on the load resistor, thereby realizing real-time collection of the secondary current signal during the welding process.

[0009] Preferably, a signal display and analysis system is used which integrates an aviation plug, a metal wire, a filter amplifier, and a data acquisition card.

[0010] Preferably, the aviation plug is used to dock with the inside of the vacuum chamber and receive the secondary current collected by the thin copper plate.

[0011] Preferably, the metal wire is used to transmit the secondary current received by the aviation plug.

[0012] Preferably, the filter amplifier is used to filter and amplify the secondary current transmitted by the metal wire.

[0013] Preferably, the data acquisition card is used to collect data on the filtered and amplified secondary current and convert it into a digital secondary current signal.

[0014] Preferably, a signal display and analysis system integrating a computer and a processor is used.

[0015] Preferably, the digital secondary current signal is digitized by a processor and transmitted to a computer, wherein the digitization processing includes Fourier transform.

[0016] Preferably, the digitally processed secondary current signal is displayed online and the signal spectrum and characteristic values ​​are analyzed in real time by a computer.

[0017] The advantages and beneficial effects of the present invention are: providing a secondary current signal detection method for vacuum laser welding, which can collect the secondary current signal during vacuum laser welding in real time, and can perform signal processing, online display and real-time analysis on the secondary current signal; so as to realize non-invasive online monitoring of vacuum laser welding by monitoring the secondary current signal. DETAILED DESCRIPTION

[0018] The specific implementation of the present invention is further described below in conjunction with the examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention, and cannot be used to limit the protection scope of the present invention.

[0019] The technical solutions specifically implemented in the present invention are as follows:

[0020] The present invention provides a secondary current signal detection method for vacuum laser welding, comprising:

[0021] During vacuum laser welding, in a vacuum chamber, metal materials are irradiated by laser, and a large number of free electrons are generated inside the metal vapor and plasma formed by the evaporation of the material. These free electrons are secondary electrons, and the current formed by the secondary electrons is the secondary current.

[0022] A thin copper plate is set as a secondary current collector in the vacuum chamber of vacuum laser welding. The thin copper plate is connected to the top of the welding plate. A potential difference is generated between the thin copper plate and the workpiece, and an external load resistor is connected to form a loop. According to the plasma wave characteristics, the electron movement speed is faster during the laser welding process, which can form a potential difference relative to the laser incident axis direction. The formula is as follows:

[0023]

[0024] The thin copper plate outputs the collected secondary current to the outside, generating a voltage drop on the load resistor, thus realizing the real-time collection of the secondary current signal during the welding process;

[0025] An electrical signal connection and amplification system integrating an aerial plug, a metal wire, a filter amplifier, and a data acquisition card is used to transmit and amplify the collected secondary current signal; the aerial plug is used to connect with the vacuum chamber and receive the secondary current collected by the thin copper plate; the metal wire is used to transmit the secondary current received by the aerial plug; the filter amplifier is used to filter and amplify the secondary current transmitted by the metal wire; the data acquisition card is used to collect data on the filtered and amplified secondary current and convert it into a digital secondary current signal;

[0026] A signal display and analysis system integrating a computer and a processor is used. The processor performs digital processing such as Fourier transform on the amplified secondary current signal and transmits it to the computer. The computer displays the digitally processed secondary current signal online and analyzes the signal spectrum and characteristic values ​​in real time, thus completing the detection of the secondary current signal in the vacuum laser welding process.

[0027] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A secondary current signal detection method for vacuum laser welding, characterized in that: include: A thin copper plate is placed in the vacuum chamber of the vacuum laser welding as a secondary current collector; An electrical signal connection amplification system is used to transmit and amplify the collected secondary current signal; The signal display and analysis system is used to digitally process the digital secondary current signal, and the digitally processed secondary current signal is displayed online and analyzed in real time.

2. The secondary current signal detection method for vacuum laser welding according to claim 1 is characterized in that: A thin copper plate is connected to the top of the welding plate to generate an electric potential difference between the thin copper plate and the workpiece, and an external load resistor is connected to form a loop; the thin copper plate outputs the collected secondary current to the outside, generating a voltage drop on the load resistor, thereby realizing real-time collection of the secondary current signal during the welding process.

3. The secondary current signal detection method for vacuum laser welding according to claim 1, characterized in that: It adopts a signal display and analysis system that integrates aviation plug, metal wire, filter amplifier and data acquisition card.

4. The secondary current signal detection method for vacuum laser welding according to claim 3 is characterized in that: The aviation plug is used to dock with the inside of the vacuum chamber and receive the secondary current collected by the thin copper plate.

5. The secondary current signal detection method for vacuum laser welding according to claim 4 is characterized in that: The metal wire is used to transmit the secondary current received by the aviation plug.

6. The secondary current signal detection method for vacuum laser welding according to claim 6, characterized in that: The filter amplifier is used to filter and amplify the secondary current transmitted by the metal wire.

7. The secondary current signal detection method for vacuum laser welding according to claim 5, characterized in that: The data acquisition card is used to collect data on the filtered and amplified secondary current and convert it into a digital secondary current signal.

8. The secondary current signal detection method for vacuum laser welding according to claim 1, characterized in that: It adopts a signal display and analysis system that integrates computers and processors.

9. The secondary current signal detection method for vacuum laser welding according to claim 8, characterized in that: The digital secondary current signal is digitized by the processor and transmitted to the computer, wherein the digitization processing includes Fourier transform.

10. The secondary current signal detection method for vacuum laser welding according to claim 9, characterized in that: The digitally processed secondary current signal is displayed online by a computer, and the signal spectrum and characteristic value are analyzed in real time.

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