Automatic light-changing filter lens and welding mask comprising same

Abstract

The automatic light-changing filter lens comprises a micro-control unit, a photoelectric sensor, a welding current sensing unit and a light-changing protection unit, wherein the photoelectric sensor, the welding current sensing unit and the light-changing protection unit are coupled with the micro-control unit; the photoelectric sensor is configured to execute arc detection and send a first signal representing the existence of an arc to the micro-control unit; the welding current sensing unit is configured to receive and process a second signal representing existence of welding current from an external welding current sensing device and send the second signal to the micro-control unit; the automatic light-changing filter lens can be selectively operated in a mode based on arc detection and / or welding current detection, and in the corresponding mode, the micro-control unit outputs a control signal to the light-changing protection unit based on the received first signal and / or second signal; the liquid crystal driving circuit in the light changing protection unit excites the liquid crystal box assembly to achieve the expected shading degree under the condition that the control signal is received. The invention also relates to a corresponding welding mask and to a method for determining whether to initiate an automatic dimming in an electric welding operation.

Description

Technical Field

[0001] The present invention generally relates to welding protection equipment, and more particularly to an automatic darkening filter (ADF) for providing eye protection for welding operators during welding operations. The present invention also relates to a welding helmet including the automatic darkening filter and a detection and control method for starting a liquid crystal darkening operation. Background Art

[0002] At present, in the production operations of arc welding or gas cutting, automatic darkening filter (ADF) products are used as visual safety protection. Common ADF products are mainly composed of the following components, including but not limited to photoelectric sensors, light valve liquid crystal boxes, and signal preprocessing, processing, driving and execution, main control and other related circuits, supporting structures, etc.

[0003] The working principle of the automatic darkening welding mask is to detect the arc (including infrared, ultraviolet, visible light, etc.) generated during welding through the photoelectric sensor circuit, and then the control circuit of the light valve liquid crystal box applies the corresponding driving signal to the ADF liquid crystal box according to the appropriate light transmittance calculated by preset or real-time detection. The light valve liquid crystal box will change its transmittance, reduce the transmittance of visible light, weaken the strong light to the weak light that the human eye can bear, and filter the infrared and ultraviolet rays generated by the arc that are harmful to the human eye.

[0004] The working mode of the automatic darkening welding mask on the market is as follows: when not welding, the light valve liquid crystal box is in the bright state, the field of vision is clear and bright, which is convenient for the operator to observe the welding part and make preparations before welding. When the arc is generated at the moment of welding, the automatic darkening welding mask instantly changes from the bright state to the dark state to protect the operator's eyes and skin from the welding arc. When welding stops, it changes from the dark state to the bright state again, and the operator can clearly observe the welding effect and prepare for the next welding operation.

[0005] The core of the existing automatic darkening welding helmet lies in its built-in photoelectric sensor and liquid crystal color change technology. Among them, the photoelectric sensor can detect the changes in the welding arc in real time, and the liquid crystal color change technology quickly adjusts the light transmittance of the mask according to the light intensity captured by the sensor. For the photoelectric sensor, it is required to be extremely sensitive to the welding arc and be able to quickly capture the changes in light intensity. As welding begins, the arc intensity rises rapidly, and the sensor immediately captures this change. There are many types of common photoelectric sensors, and their operating bands include but are not limited to the visible light and near-infrared range.

[0006] However, there are still the following problems for this type of automatic dimming filter using a photoelectric sensor. First, the automatic dimming filter will be interfered by special light sources in the environment, and there is a probability of erroneous dimming. Secondly, when there are multiple workstations in the work area performing welding operations at the same time, it is easy for the arc generated by welding at a certain workstation to irradiate a large space to the adjacent workstation, causing the automatic dimming filter in the adjacent workstation that should not be operated to also operate at the same time due to the above-mentioned erroneous dimming, resulting in mutual interference, thereby causing functional failure. More seriously, if the photoelectric sensor is damaged or accidentally blocked, affecting the mode switching of the ADF from the bright state to the dark state, it may cause damage to the operator's vision, or seriously affect work efficiency, or even cause industrial accidents.

[0007] It should be noted that the "background technology" section is only used to help understand the content of the present invention, so the content disclosed in the "background technology" section may contain some prior art that is not known to those skilled in the art. The content disclosed in the "background technology" section does not mean that the content or the problems to be solved by one or more embodiments of the present invention have been known or recognized by those skilled in the art before the application of the present invention. Summary of the invention

[0008] In view of the above-mentioned defects in the prior art, it is necessary to provide an improved automatic darkening filter and corresponding detection means to avoid the problem of ADF misoperation caused by the above-mentioned scenario, thereby effectively enhancing the protection function of related equipment.

[0009] To achieve the above-mentioned object, the present invention provides an automatic dimming filter for welding protection, comprising: a microcontroller unit and a photoelectric sensor, a welding current sensing unit and a dimming protection unit respectively coupled thereto;

[0010] The photoelectric sensor is configured to perform arc detection and send a first signal indicating the presence of an arc to the micro control unit;

[0011] The welding current sensing unit is configured to receive and process a second signal indicating the presence of welding current from a welding current sensing device outside the automatic darkening filter, and send the second signal to the micro control unit;

[0012] The automatic darkening filter is selectively operable in a detection mode based on arc detection and / or welding current detection, wherein in the corresponding detection mode, the micro control unit outputs a control signal to the darkening protection unit based on receiving the first signal and / or the second signal; and

[0013] The light-changing protection unit includes a liquid crystal driving circuit and a liquid crystal box component electrically connected to the liquid crystal driving circuit. When receiving the control signal from the micro control unit, the liquid crystal driving circuit stimulates the liquid crystal box component to achieve the expected light shielding degree.

[0014] Preferably, the automatic darkening filter further comprises an operating parameter setting unit, which is pre-set with default operating parameters related to the operation of the automatic darkening filter and / or receives operating parameters input by an operator and sends the operating parameters to the micro control unit.

[0015] Preferably, the working parameters include detection mode parameters of the automatic darkening filter, based on which the automatic darkening filter operates in one of the detection modes based on both arc detection and welding current detection, based on arc detection or based on welding current detection.

[0016] Preferably, when the automatic dimming filter operates in a detection mode based on both arc detection and welding current detection, the microcontroller unit outputs a control signal to the dimming protection unit when it receives both a first signal indicating the presence of an arc and a second signal indicating the presence of a welding current, so that the liquid crystal box assembly achieves the expected shading level that can be achieved during normal welding operation.

[0017] Optionally, when the automatic dimming filter operates in a detection mode based on both arc detection and welding current detection, the microcontroller unit does not output a control signal to the dimming protection unit when it only receives a first signal indicating the presence of an arc but does not receive a second signal indicating the presence of a welding current, so that the liquid crystal box assembly remains in an initial bright state.

[0018] Optionally, when the automatic dimming filter is operated in a detection mode based on both arc detection and welding current detection, the microcontroller unit, when receiving only the second signal indicating the presence of welding current but not the first signal indicating the presence of arc, can output a control signal to the dimming protection unit based on a transient darkness from the working parameter setting unit so that the liquid crystal box component achieves the transient darkness, wherein the range of the transient darkness is between the darkness corresponding to the liquid crystal box component in the initial bright state and the DIN No. 7 darkness. When the microcontroller unit further receives the first signal indicating the presence of arc within a subsequent threshold time period, the microcontroller unit outputs a control signal to the dimming protection unit so that the liquid crystal box component further dims from the transient darkness to achieve the expected shading degree that can be achieved during normal welding operation; conversely, when the microcontroller unit does not further receive the first signal indicating the presence of arc within a subsequent threshold time period, the microcontroller unit stops outputting a control signal to the dimming protection unit so that the liquid crystal box component returns from the transient darkness to the initial bright state.

[0019] Optionally, the automatic dimming filter also includes a liquid crystal signal control unit coupled to the microcontroller unit and the liquid crystal drive circuit. Depending on the corresponding detection mode, the microcontroller unit is capable of outputting a control signal to the liquid crystal signal control unit based on receiving the first signal and / or the second signal and pre-set or input working parameters from a working parameter setting unit. The liquid crystal signal control unit then provides the liquid crystal drive circuit with the driving voltage required to excite the liquid crystal box assembly based on the control signal.

[0020] According to another aspect of the present invention, there is provided a welding helmet including the above-mentioned automatic darkening filter, which includes a mask body having a mounting opening, and the automatic darkening filter can be detachably mounted in the mounting opening.

[0021] According to another aspect of the present invention, there is provided a method for determining whether to activate automatic dimming of a welding helmet during an electric welding operation, comprising the following steps:

[0022] A welding mask and an electric welding system according to the above invention are provided, wherein the electric welding system comprises a welding machine, a welding gun and a welding current sensing device, wherein the welding machine is electrically connected to the welding gun via a welding gun line and is electrically connected to a workpiece to be welded via a grounding line, wherein the welding current sensing device is used to detect the welding current flowing between the welding machine, the welding gun and the workpiece to be welded, and the welding current sensing device is communicatively coupled to a welding current sensing unit in an automatic darkening filter of the welding mask;

[0023] selecting a detection mode of the auto-darkening filter, the detection mode comprising arc detection performed using a photoelectric sensor and / or welding current detection performed using a welding current sensing device;

[0024] Based on the selected detection mode and the fact that the photoelectric sensor detects a first signal indicating the presence of an arc and / or the welding current sensing device detects a second signal indicating the presence of a welding current during the welding operation, the microcontroller unit sends a control signal to the liquid crystal drive circuit in the dimming protection unit. Upon receiving the control signal from the microcontroller unit, the liquid crystal drive circuit excites the liquid crystal box assembly to achieve the desired shading degree.

[0025] Preferably, the welding current sensing device is arranged in any of the following ways: located between the welding machine and the welding gun, located between the welding machine and the workpiece to be welded, as an accessory or a part thereof connected to the welding machine via a standard interface, and modularized for integration into the welding machine.

[0026] Preferably, the welding current sensing device is communicatively coupled to the welding current sensing unit in the automatic darkening filter in any one of a wired connection, a wireless connection, or a combination of a wireless receiver and a wired connection.

[0027] Preferably, the welding current sensing device detects the welding current in a non-directly associated and non-invasive manner, and the welding current sensing device is selected from one or more of a current transformer, a Hall current sensor, a fluxgate current sensor, a Rogowski coil, or a giant magnetoresistance current sensor.

[0028] The automatic darkening filter according to the present invention further combines an enhanced detection scheme based on welding current induction detection on the basis of the original detection scheme of the photoelectric sensor, which can reduce the risk of misoperation and enhance the protection performance of related equipment (such as an automatic darkening welding mask or helmet). BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and other aspects of the present invention will be more thoroughly understood and appreciated with reference to the accompanying drawings, in which:

[0030] Figure 1 is a schematic diagram of an electric welding operation, wherein a conventional automatic darkening filter using a photoelectric sensor for detection is shown;

[0031] Figure 2 A schematic diagram of an enhanced detection scheme and its application principle according to the present invention;

[0032] Figure 3A schematic block diagram of an automatic dimming filter according to the present invention, wherein the automatic dimming filter combines conventional photoelectric sensor detection with detection of welding current to determine whether to activate automatic dimming;

[0033] Figure 4 is a schematic diagram of an auto-darkening welding helmet including an improved auto-darkening filter according to the present invention;

[0034] Figure 5 To determine Figure 4 A flow chart of a method for determining whether an auto-darkening welding helmet is activated during an electric welding operation. DETAILED DESCRIPTION

[0035] In order to make the technical problems, technical solutions and beneficial technical effects to be solved by the present invention clearer, the present invention will be further described in detail in conjunction with the accompanying drawings and exemplary embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the scope of protection of the present invention. Unless otherwise clearly stated in the drawings, the sizes, positions, etc. of various parts, features, elements, etc. and any distances therebetween are not necessarily drawn to scale, and may be disproportionate and / or exaggerated for the sake of clarity.

[0036] The terms used herein are only used to describe the purpose of specific exemplary embodiments, and are not intended to be restrictive. As used herein, unless the context clearly indicates, the singular forms "one", "an" and "the" are intended to also include plural forms. It should be recognized that the terms "include", "comprise" and / or "compose" when used in this specification specify the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or combinations thereof. Unless otherwise indicated, when the range of values ​​is enumerated, the upper and lower limits of the range are included, as well as any sub-ranges therebetween. Unless otherwise specified, terms such as "first", "second", etc., are only used to distinguish one element from another element. For example, an element may be referred to as a "first element", and similarly, another element may be referred to as a "second element", and vice versa. The paragraph titles used herein are only used for organizational purposes and should not be interpreted as limiting the subject matter described.

[0037] Unless expressly indicated otherwise, the terms "about," "approximately," "substantially," and the like mean that quantities, sizes, formulations, parameters, and other quantities and features are not and need not be exact, but may be approximate and / or larger or smaller as desired.

[0038] Unless otherwise expressly indicated, all connections and all operative connections may be direct or indirect. Likewise, unless otherwise expressly indicated, all connections and all operative connections may be rigid or non-rigid. In addition, in the present invention, the term "connection / coupling" includes not only mechanical connections, but also electrical connections and communicative couplings between components and / or units / modules.

[0039] Like reference numerals refer to like elements throughout the text. Therefore, the same or similar reference numerals may be described with reference to other figures even if they are neither mentioned nor described in the corresponding figures. Moreover, even elements that are not marked with reference numerals may be described with reference to other figures.

[0040] Reference Figure 1 The existing electric welding system includes a welding machine 2 and a welding gun 3 connected to the welding machine 2 via a welding gun line 23. In addition, the welding machine 2 is further connected to a workpiece 4 to be welded via a grounding wire 24. The workpiece 4 to be welded has a welding work surface 40. When the electric welding operation is performed, the welding wire at the end of the welding gun 3 is manually rubbed on the welding work surface 40 (i.e., the usual arc starting operation, so that a small air gap is generated between the welding wire and the welding work surface 40), thereby forming a closed loop between the welding gun 3, the workpiece 4 to be welded and the welding machine 2, and a welding current is generated at this time. When a large welding current flows through the above-mentioned air gap, a dazzling arc and high-temperature sparks will be generated. The high-temperature sparks further heat the welding work surface 40 and melt the welding wire to fill the surface gap of the welding work surface 40, thereby completing the electric welding operation.

[0041] Further, Figure 1 The figure also schematically shows an existing automatic dimming filter 1 for welding protection (especially for welding helmets), the automatic dimming filter 1 includes a photoelectric sensor 100, a microcontroller unit MCU and a dimming protection unit 300, the photoelectric sensor 100 is configured to detect the optical signal indicating whether a welding arc exists (as shown by the dotted arrow in the figure), and convert the detected optical signal into an electrical signal to be sent to the microcontroller unit MCU electrically connected thereto for subsequent analysis and processing. The dimming protection unit 300 includes a liquid crystal drive circuit 310 electrically connected to the microcontroller unit MCU and a liquid crystal box assembly LCD electrically connected to the liquid crystal drive circuit 310 to change the light transmission state in response to the excitation from the liquid crystal drive circuit 310 (see for a more detailed view). Figure 3, which schematically shows two liquid crystal box components LCD1 and LCD2). The liquid crystal box component LCD is displayed in a bright state (corresponding to a relatively low shading degree, the darkness value is usually between DIN 3 and 4) when it is not driven by voltage in the initial state, and is displayed in a dark state (corresponding to a relatively high shading degree, depending on the change of the driving voltage, the darkness value is usually between DIN 5 and 14) when it is driven by voltage. As introduced in the background technology part, the above automatic darkening welding mask based on arc detection may be dimmed incorrectly for various reasons. For this reason, the present invention further proposes a detection scheme combined with welding current to supplement and enhance the existing detection scheme.

[0042] Specifically, in Figure 1 Based on the existing electric welding system shown in Figure 1 The same parts will not be repeated below), such as Figure 2 As shown, a welding current sensing device 5 is further added. Although the principles of the welding current sensing device are generally based on Ohm's law, Ampere's law and Faraday's law of electromagnetic induction, Hall effect, photoelectric effect, etc., the measurement and sampling of the welding current in the welding scenario should be suitable for non-directly associated inductive work, in other words, excluding the sampling principle of the resistance shunt based on Ohm's law. Accordingly, the specific type selection of the above-mentioned welding current sensing device can be based on and is not limited to: 1) current transformer; 2) Hall current sensor; 3) fluxgate current sensor; 4) Rogowski coil; 5) giant magnetoresistance current sensor, etc. In this case, the welding current can be detected and sampled in a manner that is not directly associated with the traditional system or non-invasive (that is, there is no need to directly contact the circuit under test and will not interfere with the circuit). Taking the caliper-type current transformer as an example, when sampling the welding current, it is only necessary to place the welding gun wire 23 or the ground wire 24 in the jaws of the caliper to complete the operation without adding a resistance shunt to the existing connection line. In addition, according to Figure 2 As shown, the welding current sensing device 5 can be preferably installed on one side of the welding gun line 23 (as shown in the solid line frame in the figure, that is, the device detects the welding current flowing between the welding gun 3 and the welding machine 2), or alternatively installed on one side of the grounding wire 24 between the welding machine 2 and the workpiece 4 to be welded (as shown in the dotted line frame in the figure, that is, the device detects the welding current flowing between the welding machine 2 and the workpiece 4 to be welded). When the welding current sensing device 5 is installed on one side of the welding gun line 23, the distance from the welding current sensing device 5 to the automatic darkening filter 10 is shorter, especially in the case of a wired connection, which can reduce the restriction on the cable length.

[0043] Reference Figure 3, which shows a schematic block diagram of the automatic darkening filter 10 according to the present invention. Different from the conventional ADF product that realizes automatic darkening control by sensing the welding arc through a photoelectric sensor, the automatic darkening filter 10 of the present invention is further provided with a welding current sensing unit 200 for receiving and processing the welding current signal. After the welding machine is started, the welding gun starts welding at the moment when the welding current is generated in the welding gun line and the ground wire as the source signal. Figure 2 The welding current sensing device 5 in the automatic darkening filter 10 detects the welding current, and the detected welding current signal is sent to the welding current sensing unit 200 and further communicated to the microcontroller unit MCU. On the other hand, the photoelectric sensor 100 in the automatic darkening filter 10 also detects the welding arc caused by the arc starting operation and further sends a signal indicating the existence of the arc to the microcontroller unit MCU. When the microcontroller unit MCU receives the welding current signal and the arc signal at the same time (i.e., it is determined that the operator starts welding), the microcontroller unit MCU outputs a control signal to the liquid crystal drive circuit 310 in the darkening protection unit 300, and then the corresponding liquid crystal drive circuit 310 applies a specific drive voltage to the liquid crystal box assembly LCD (shown as two LCD1 and LCD2 in the figure, but it can be one or more as needed), thereby controlling the automatic darkening filter to change from the initial bright state before the operation to the dark state to achieve the human eye protection function.

[0044] Further references Figure 2, the welding current signal detected by the welding current sensing device can be sent to the welding current sensing unit of the automatic darkening filter 10 in the following ways, namely: a) wired connection; b) wireless connection; and c) using a combination of a wireless receiver 510 and a wired connection. Among them, a transmitting circuit is provided in the welding current sensing device, and the transmitting circuit includes a current-voltage conversion circuit and a transmitting module; correspondingly, the welding current sensing unit in the automatic darkening filter includes a corresponding receiving module, an integrated voltage stabilizer, a multivibrator, and an electrical signal receiving and processing circuit. The above modules / components are well known to those skilled in the art, and their structures and operating principles are not repeated here. When a wired connection is used, the cable connection between the welding current sensing device 5 and the automatic darkening filter 10 is relatively simple to implement, but it will be subject to length restrictions, and this is especially true when the welding current sensing device 5 is configured to detect and sample the welding current flowing through the ground wire 24. When wireless connection is used, the connection is convenient and the limitation of cable length in the above-mentioned wired connection is avoided, but at the same time, higher requirements are put forward on the layout of each printed circuit board (PCB) inside the automatic dimming filter 10 and how to control power consumption. Compared with using wired connection or wireless connection alone, the signal transmission method using a combination of the two can combine the advantages of the above-mentioned two solutions and produce the following beneficial effects: i) avoiding the limitation of cable length or work interference of wired connection; ii) convenience of wireless connection; iii) solving the technical problems of limited space in the structure of the automatic dimming filter body and limited PCB layout space; iv) reducing the influence of wireless unit power consumption on automatic dimming; and v) at the same time, through the wireless receiving unit external to the automatic dimming filter, a unified standard interface can be selected between the automatic dimming filter body and the automatic dimming filter body, and various automatic dimming filter product bodies only need to provide such standard interfaces, and will not be affected by the solution of the external wireless receiving unit.

[0045] Further, Figure 4 The overall schematic diagram of a welding helmet according to the present invention is shown, and the welding helmet comprises a mask body 20 and an automatic darkening filter 10 as described above in the specification, wherein the mask body 20 is used to be connected with a headband structure (not shown in the figure) to be worn on the operator's head. As further shown in the figure, the automatic darkening filter 10 is detachably mounted at a front mounting opening 201 of the mask body 20, so that when the operator wears it, the liquid crystal box assembly of the automatic darkening filter 10 is aligned with the operator's eyes.

[0046] It should be noted that the above only uses the preferred embodiments as examples to explain and illustrate the principles of the present invention. However, the present invention is not limited to the specific structures in the above preferred embodiments, but further improvements and modifications can be made.

[0047] For example, in an alternative embodiment, the welding current sensing device 5 can be implemented as an accessory or a part of an accessory adapted to the welding machine 2, and the accessory can be connected to the welding machine 2 via a standard interface. In this case, the welding gun line 23 and the ground line 24 can be connected to the above-mentioned accessory to complete the entire welding circuit and realize the sensing of the welding current. It can be understood that as long as the sensing of the welding current can be realized and the corresponding signal can be sent to the welding current sensing unit 200 of the automatic darkening filter 10 provided in the welding mask, the above-mentioned welding current sensing device 5 can also be modularized and integrated in the existing welding machine 2.

[0048] Further Figure 3As shown, the automatic dimming filter 10 according to the present invention also includes a working parameter setting unit 400, which can be pre-set with default working parameters related to the operation of the automatic dimming filter 10 and / or receive the self-defined working parameters input by the operator, and send the working parameters to the microcontroller unit MCU. In addition to the traditional shading control parameters, sensitivity control parameters, delay control parameters, and working mode parameters such as grinding, welding, cutting, etc., the working parameters also include the detection mode parameters of the automatic dimming filter in the present invention. For the input and display of parameters, the working parameter setting unit 400 can preferably use the setting method of selecting buttons to input the working parameters to be adjusted and display the adjusted working parameters via a display device in the form of an LED screen. Those skilled in the art can also foresee the use of human-machine interaction modules such as knobs, resistive or capacitive touch screens to adjust the above working parameters. For example, by default, the automatic dimming filter according to the present invention adopts a detection mode combining arc detection and welding current induction, but the operator can select any one of the two detection modes as a standard for judging whether to start the automatic dimming of the liquid crystal box assembly according to actual needs. The selection of the above detection mode can be realized by the working parameter setting unit 400. For example, in the case where a single person performs welding operation and is not easily disturbed by the arc from the adjacent workstation, the detection mode of the automatic darkening filter can be set to rely only on the photoelectric sensor 100 for arc detection with the help of the working parameter setting unit 400. At this time, as long as the photoelectric sensor 100 detects the arc and converts the optical signal into an electrical signal and sends it to the microcontroller unit MCU, the microcontroller unit MCU can send a control signal to the liquid crystal drive circuit 310 based on the default pre-stored or manually set working parameters from the working parameter setting unit 400, and then the liquid crystal drive circuit 310 applies a corresponding driving voltage to the liquid crystal box assembly, and the arrangement state of the liquid crystal molecules inside the liquid crystal box assembly changes. At this time, the polarization direction of the incident linear polarized light will be perpendicular to the light transmission axis direction of the outgoing polarizer and blocked, thereby achieving the expected shading degree. It should be noted that the "expected shading degree" referred to herein includes but is not limited to the shading degree to be achieved during normal welding operation that is pre-stored or manually set by the working parameter setting unit 400 by default, and the shading degree can be changed within a preset range or can be corrected by the microcontroller unit during operation according to the needs of different operators. On the other hand, if it is determined that the photoelectric sensor 100 is easily blocked or damaged in the current working environment, the detection mode of the automatic darkening filter can be set to rely only on the detection of the welding current by the external welding current sensing device through the working parameter setting unit 400.At this time, the welding current sensing device senses the welding current and sends an electrical signal to the welding current sensing unit 200 in the automatic dimming filter and further to the microcontroller unit MCU. The microcontroller unit MCU will send a corresponding control signal to the liquid crystal drive circuit 310, and then the liquid crystal drive circuit 310 applies a corresponding drive voltage to the liquid crystal box assembly to achieve the expected shading degree.

[0049] Furthermore, when the automatic dimming filter is in the default operation mode combining arc detection and welding current sensing, if the automatic dimming filter only receives a signal indicating the existence of an arc but does not receive a signal indicating the existence of a welding current (the reason for such a situation is usually due to interference from adjacent workstations), according to practical experience, even if the automatic dimming filter currently used by the operator remains in the initial bright state (darkness value DIN between 3 and 4), the light generated by the arc at the adjacent workstation will not cause damage to his eyes. In this case, the microcontroller unit MCU does not send a control signal to the liquid crystal drive circuit 310 in the dimming protection unit 300, so that the liquid crystal box assembly remains in the initial bright state, thereby ensuring that the operator is not disturbed by the false dimming light and can still observe the surrounding working environment. On the other hand, when the automatic dimming filter is in the default operation mode combining arc detection and welding current sensing, if the automatic dimming filter only receives a signal indicating the presence of a welding current but does not receive a signal indicating the presence of an arc (the reason may be a delay caused by the time difference between the generation and transmission of the two signals. Generally speaking, the signal indicating the presence of a welding current will be received earlier), the microcontroller unit MCU can send a control signal to the liquid crystal drive circuit 310 based on a transient darkness from the working parameter setting unit (the range of the transient darkness is between the darkness corresponding to the liquid crystal box component in the initial bright state (usually DIN 3~4) and the DIN 7 darkness), and the liquid crystal drive circuit 310 then applies a corresponding drive voltage to the liquid crystal box component to achieve light shielding corresponding to the transient darkness. Furthermore, when the microcontroller unit MCU further receives the first signal indicating the existence of an arc within a subsequent threshold time period, the microcontroller unit MCU outputs a control signal to the liquid crystal drive circuit 310 in the dimming protection unit 300 so that the liquid crystal box component is further dimmed from the transient darkness to achieve the expected shading degree (any preset value within the range of DIN 5 to 14 provided by the ADF, such as DIN 11) that can be achieved during normal welding operation; conversely, when the microcontroller unit MCU does not further receive the first signal indicating the existence of an arc within a subsequent threshold time period, the microcontroller unit MCU stops outputting a control signal to the liquid crystal drive circuit 310 in the dimming protection unit 300 so that the liquid crystal box component is restored from the transient darkness to the initial bright state. In the above manner, the operator's eyes can be protected while avoiding the automatic dimming filter from erroneous dimming operation in extreme cases.

[0050] In addition, a liquid crystal signal control unit 500 coupled to the microcontroller unit MCU and the liquid crystal drive circuit 310 may be provided in the automatic dimming filter 10. Depending on the detection mode set by the working parameter setting unit 400, the microcontroller unit MCU can output a control signal to the liquid crystal signal control unit 500 based on the signal from the photoelectric sensor 100 and / or the welding current sensing unit 200 and the preset or input working parameters from the working parameter setting unit 400. The liquid crystal signal control unit 500 further provides the liquid crystal drive circuit 310 with the driving voltage required to excite the liquid crystal box component based on the control signal from the microcontroller unit MCU. The liquid crystal signal control unit 500 can adjust the driving voltage by means of at least one of digital-to-analog conversion, pulse width modulation and RC discharge. Compared with the microcontroller unit MCU directly sending the control signal to the liquid crystal drive circuit 310 in the aforementioned embodiment, in practical operation, a more complex dimming operation of the automatic dimming filter can be realized by means of the liquid crystal signal control unit 500. For example, it can select different liquid crystal driving circuits 310 to control the corresponding liquid crystal box components by switching a switch to simultaneously adjust the darkness and chromaticity, so as to adapt to the habits of different operators; it can also send driving signals representing corresponding driving voltages in different time periods to the liquid crystal driving circuit 310, so as to achieve non-step changes in darkness to enhance the protection function of the operator's glasses and improve comfort, etc.

[0051] Figure 5 The block diagram shows the steps of the method for determining whether to activate the automatic dimming of the welding mask during the welding operation. It can be understood by those skilled in the art that the automatic dimming filter and the welding mask including the same according to the present invention have functional modules and beneficial effects corresponding to the method. The various steps and technical details of executing the method can be stored in the corresponding functional modules in the form of software, or implemented in the form of a combination of software and hardware. The technical features described in the above embodiments of the ADF product and all optional / alternative technical details can be correspondingly combined with the method.

[0052] At step S110, a welding mask including the automatic darkening filter according to the present invention and Figure 3The electric welding system shown in the figure comprises a welding machine, a welding gun and a welding current sensing device, wherein the welding machine is electrically connected to the welding gun via a welding gun wire and is electrically connected to a workpiece to be welded via a ground wire, wherein the welding current sensing device is used to detect the welding current flowing between the welding machine, the welding gun and the workpiece to be welded, and the welding current sensing device is communicatively coupled to the welding current sensing unit in the automatic darkening filter, wherein the welding current sensing device is coupled to the welding current sensing unit in the automatic darkening filter in any one of a wired connection, a wireless connection, or a combination of a wireless receiver and a wired connection.

[0053] At step S120, a detection mode of the automatic darkening filter is selected, the detection mode including arc detection performed by a photoelectric sensor and / or welding current detection performed by a welding current sensing device. In a default state, the automatic darkening filter operates in a detection mode based on both arc detection and welding current detection. According to actual needs, the operator can also use the human-computer interaction module in the working parameter setting unit to select the detection mode operation based solely on arc detection or solely on welding current detection.

[0054] At step S130, based on the detection mode selected in the aforementioned step S120 and the fact that the photoelectric sensor detects an arc signal and / or the welding current sensing device detects a welding current signal during the welding operation, the microcontroller unit in the automatic dimming filter sends a control signal to the liquid crystal drive circuit in the dimming protection unit, and the liquid crystal drive circuit then applies a driving voltage to the liquid crystal box assembly to excite the liquid crystal box assembly to achieve the desired shading degree.

[0055] In summary, according to the principle of the present invention, by combining photoelectric sensing with welding current sensing to determine under what circumstances the microcontroller unit in the automatic dimming filter outputs a control signal to dim the liquid crystal box component, it is possible to effectively avoid possible misoperation or non-operation of the traditional solution, and greatly enhance the reliability of the system operation mode switching, its safety and work efficiency. In addition, since the inductive sampling scheme for welding current in the present invention adopts a non-directly associated inductive working principle, there is no need to bind the welding machine model, and support includes but is not limited to AC welding machines or DC welding machines, and has very good adaptability to the application environment.

[0056] The above describes in detail a feasible but non-limiting implementation of the automatic dimming filter and the detection and control method of dimming activation according to the present invention with the aid of the accompanying drawings. For those skilled in the art, without departing from the scope and essence of the present disclosure as set forth in the following claims, modifications and supplements to the technology and structure and the re-combination of the features in each embodiment should be considered to be included in the scope of the present invention. Therefore, these modifications and supplements that can be conceived under the teachings of the present invention should be considered as part of the present disclosure. The scope of the present disclosure is defined by the following claims and includes equivalent technologies known at the filing date of the present disclosure and equivalent technologies that have not yet been foreseen.

Claims

1. An automatic darkening filter (10) for welding protection, comprising: A microcontroller unit (MCU) and a photoelectric sensor (100), a welding current sensing unit (200) and a light-changing protection unit (300) respectively coupled thereto; The photoelectric sensor (100) is configured to perform arc detection and send a first signal indicating the presence of an arc to the micro control unit (MCU); The welding current sensing unit (200) is configured to receive and process a second signal indicating the presence of welding current from a welding current sensing device (5) outside the automatic darkening filter (10), and send the second signal to the micro control unit (MCU); The automatic darkening filter (10) is selectively operable in a detection mode based on arc detection and / or welding current detection, wherein in the corresponding detection mode, the micro control unit (MCU) outputs a control signal to the darkening protection unit (300) based on receiving the first signal and / or the second signal; and The light-changing protection unit (300) comprises a liquid crystal drive circuit (310) and a liquid crystal box component electrically connected to the liquid crystal drive circuit (310); the liquid crystal drive circuit (310) stimulates the liquid crystal box component to achieve a desired light shielding degree when receiving the control signal from a microcontroller unit (MCU).

2. The automatic darkening filter (10) according to claim 1, further comprising an operating parameter setting unit (400), which is pre-set with default operating parameters related to the operation of the automatic darkening filter (10) and / or receives operating parameters input by an operator, and sends the operating parameters to a micro control unit (MCU).

3. The automatic darkening filter (10) according to claim 2, wherein the operating parameters include detection mode parameters of the automatic darkening filter (10), based on which the automatic darkening filter (10) operates in one of the detection modes based on both arc detection and welding current detection, based on arc detection, or based on welding current detection.

4. The automatic darkening filter (10) according to claim 3, wherein: When the automatic dimming filter (10) operates in a detection mode based on both arc detection and welding current detection, the microcontroller unit (MCU) outputs a control signal to the dimming protection unit (300) when receiving both a first signal indicating the presence of an arc and a second signal indicating the presence of a welding current, so that the liquid crystal box assembly achieves the expected shading degree that can be achieved during normal welding operation.

5. The automatic darkening filter (10) according to claim 3, wherein: When the automatic dimming filter (10) operates in a detection mode based on both arc detection and welding current detection, the microcontroller unit (MCU) does not output a control signal to the dimming protection unit (300) when only a first signal indicating the presence of an arc is received but a second signal indicating the presence of a welding current is not received, so that the liquid crystal box component is maintained in an initial bright state.

6. The automatic darkening filter (10) according to claim 3, wherein: When the automatic dimming filter (10) is operated in a detection mode based on both arc detection and welding current detection, the microcontroller unit (MCU) can output a control signal to the dimming protection unit (300) based on a transient darkness from a working parameter setting unit to enable the liquid crystal box component to achieve the transient darkness, when only a second signal indicating the presence of a welding current is received but a first signal indicating the presence of an arc is not received, wherein the range of the transient darkness is between the darkness corresponding to the liquid crystal box component in an initial bright state and the DIN No. 7 darkness.

7. The automatic darkening filter (10) according to claim 6, wherein: When the microcontroller unit (MCU) further receives a first signal indicating the presence of an arc within a subsequent threshold time period, the microcontroller unit (MCU) outputs a control signal to the dimming protection unit (300) so that the liquid crystal box component further dims from the transient darkness to achieve the expected shading degree that can be achieved during normal welding operations.

8. The automatic darkening filter (10) according to claim 6, wherein: When the microcontroller unit (MCU) does not further receive a first signal indicating the existence of an arc within a subsequent threshold time period, the microcontroller unit (MCU) stops outputting a control signal to the dimming protection unit (300) so that the liquid crystal box component recovers from the transient darkness to an initial bright state.

9. The automatic dimming filter (10) according to any one of claims 3 to 8, further comprising a liquid crystal signal control unit (500) coupled to the micro control unit (MCU) and the liquid crystal drive circuit (310), wherein, depending on a corresponding detection mode, the micro control unit (MCU) is capable of outputting a control signal to the liquid crystal signal control unit (500) based on receiving the first signal and / or the second signal and a pre-set or input working parameter from a working parameter setting unit (400), and the liquid crystal signal control unit (500) further provides the liquid crystal drive circuit (310) with a driving voltage required to excite the liquid crystal box assembly based on the control signal.

10. A welding helmet, comprising an automatic darkening filter (10) according to any one of claims 1 to 9 and a mask body (20) having a mounting opening (201), wherein the automatic darkening filter (10) is detachably mounted in the mounting opening (201).

11. A method for determining whether to activate automatic dimming of a welding helmet during an electric welding operation, comprising the steps of: Provided are a welding mask according to claim 10 and an electric welding system, the electric welding system comprising a welding machine (2), a welding gun (3) and a welding current sensing device (5), the welding machine (2) being electrically connected to the welding gun (3) via a welding gun line (23) and electrically connected to a workpiece (4) to be welded via a ground line (24), the welding current sensing device (5) being used to detect the welding current flowing between the welding machine (2), the welding gun (3) and the workpiece (4) to be welded, and the welding current sensing device (5) being communicatively coupled to a welding current sensing unit (200) in an automatic darkening filter (10) of the welding mask; selecting a detection mode of the automatic darkening filter (10), the detection mode comprising arc detection performed using a photoelectric sensor (100) and / or welding current detection performed using a welding current sensing device (5); Based on the selected detection mode and the fact that the photoelectric sensor (100) detects a first signal indicating the presence of an arc and / or the welding current sensing device (5) detects a second signal indicating the presence of a welding current during a welding operation, a microcontroller unit (MCU) sends a control signal to a liquid crystal drive circuit (310) in a dimming protection unit (300). Upon receiving the control signal from the microcontroller unit (MCU), the liquid crystal drive circuit (310) stimulates the liquid crystal box assembly to achieve a desired shading degree.

12. The method according to claim 11, wherein the welding current sensing device (5) is arranged in any of the following ways: located between the welding machine (2) and the welding gun (3), located between the welding machine (2) and the workpiece (4) to be welded, as an accessory or a part thereof connected to the welding machine (2) via a standard interface, and modularized to be integrated into the welding machine (2).

13. The method according to claim 11 or 12, wherein the welding current sensing device (5) is communicatively coupled to the welding current sensing unit (200) in the automatic darkening filter (10) in any manner of wired connection, wireless connection, or a combination of a wireless receiver (510) and a wired connection.

14. The method according to claim 11 or 12, wherein the welding current sensing device (5) detects the welding current in a non-directly associated and non-invasive manner, and the welding current sensing device (5) is selected from one or more of a current transformer, a Hall current sensor, a fluxgate current sensor, a Rogowski coil, or a giant magnetoresistance current sensor.

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