CN116626927A - Automatic dimming filter for laser processing protection and protective mask - Google Patents

Abstract

The application discloses an automatic dimming filter for laser processing protection, which comprises the following components: a mounting frame; and an observation window assembly and a light sensor installed in the installation frame, wherein the light sensor is configured to generate an excitation signal after detecting intense light generated during laser processing, the observation window assembly comprises a laser protection sheet positioned on the side facing the intense light generation direction during laser processing and a liquid crystal panel positioned at the downstream of the laser protection sheet, the automatic dimming filter further comprises a control unit, the control unit is electrically connected with the light sensor, and after receiving the excitation signal, the control unit controls the liquid crystal panel to switch from an idle state to a dimming state, wherein the transmittance of the liquid crystal panel for visible light, far ultraviolet rays and infrared rays in the idle state is higher than the transmittance of the liquid crystal panel for visible light, far ultraviolet rays and infrared rays in the dimming state. The application also comprises a protective mask provided with the automatic dimming filter.

Description

Auto-darkening filters and protective visors for laser processing protection

technical field

The present application generally relates to automatic darkening filters for laser processing protection and protective visors equipped with such automatic darkening filters.

Background technique

Compared with the traditional handheld welding device, the handheld laser welding device can only occupy a single hand of the welder, which is convenient for flexible operation of the welding device. In addition, due to the high concentration of laser welding energy density, extremely fast heating and cooling speed during welding, small heat-affected zone; small welding stress and deformation; no contact processing, no external force on the weldment and other advantages are becoming more and more popular in welding operations. been widely adopted.

In the process of laser welding, welding uses laser light to irradiate the surface of the metal parts to be welded, so that a high-temperature molten pool is locally generated, thereby welding the surfaces of the two metal parts together. During this process, the irradiated laser light itself scatters at the surface of the metal part and can burn the welder's eyes and exposed skin. In addition, the high-temperature molten pool itself will produce harmful rays (rays in the visible spectrum and invisible spectrum) that are harmful to the human body due to high temperature and high heat.

Currently, welders often only wear a pair of laser safety glasses when performing handheld laser welding operations. Although this can avoid the direct exposure of the scattered laser light to human eyes, it cannot protect the exposed facial skin of the welding personnel, which may cause the harmful rays produced by the scattered laser light and the high temperature molten pool to burn the welding personnel's eyes and face. In addition, such traditional laser safety glasses only have a constant light transmittance. Therefore, for laser welding operations with different power requirements, welders must wear laser protective glasses with different light transmittance specifications to meet the protection requirements of welding operations, which will lead to a decrease in labor efficiency and if the welder wears laser protective glasses of the wrong specification It can also damage the glasses. In addition, this kind of traditional laser protective glasses often does not take into account the potential threat that the rays produced by the high temperature molten pool will also cause harm to human eyes.

In addition, if the lenses such as laser safety glasses are simply placed inside the welding mask to provide protection against laser welding, due to the complicated conditions at the welding site, if such lenses accidentally fall off, it is easy to cause laser protection failure for human eyes.

In addition, similar problems exist not only in the field of laser welding, but also in other fields that require hand-held laser processing, such as laser cutting.

Contents of the invention

In view of the above problems, the present application aims to propose a novel automatic darkening filter for laser processing, especially for laser welding protection, and a protective mask equipped with the automatic darkening filter.

According to one aspect of the present application, an automatic darkening filter for laser processing protection is provided, comprising:

mounting frame; and

An observation window assembly and an optical sensor installed in the installation frame, the optical sensor is configured to generate an excitation signal after detecting the strong light generated during laser processing, and the observation window assembly includes a a laser protection sheet on one side and a liquid crystal panel positioned upstream or downstream of the laser protection sheet,

The automatic darkening filter also includes a control unit, the control unit is electrically connected to the light sensor, and after receiving the excitation signal, the control unit controls the liquid crystal panel to switch from an idle state to a darkened state state, wherein the transmittance of the liquid crystal panel for visible light, far ultraviolet and infrared rays in the idle state is higher than that in the darkened state.

In this way, the automatic darkening filter according to the present application can not only protect the accidentally scattered laser beams during laser processing, but also protect the strong light generated by laser processing, thereby providing more comprehensive protection for human eyes.

Optionally, the transmittance of the laser protection sheet for laser light is configured so that the laser light passing through the laser protection sheet cannot damage the liquid crystal array of the downstream liquid crystal panel. Since the processing (such as welding) laser directly irradiating the liquid crystal array may burn the liquid crystal array due to excessive energy, so by properly selecting the manufacturing material and manufacturing method of the laser protection sheet to ensure that even if there is laser light passing through the laser protection sheet, this The energy of this laser is not enough to burn the liquid crystal array and provide human eyes with a barrier against the weakened energy of the transmitted laser through the automatic darkening of the liquid crystal array.

Optionally, the laser protection sheet is configured such that the transmittance of laser energy at least at a wavelength of 1064 nm or 1070 nm can reach an order of 10 ⁻³ to 10 ⁻⁶ at least. It should be clear to those skilled in the art that the corresponding national standards of the People's Republic of China can be referred to when referring to the terminology of protection level.

Optionally, the laser protection sheet is configured to have a transmittance of at least 30% for visible light. In this way, even in its idle state, the automatic darkening filter can ensure that the user can observe through the automatic darkening filter, so that it is convenient to adjust parts that have not yet been laser processed (such as laser welding) or through observation. Properly aim the aiming spot at the part to be processed, thereby avoiding errors in laser processing.

Optionally, the liquid crystal panel and the laser protection sheet are bonded together.

Optionally, the automatic darkening filter also includes a control panel, so that the transmittance of the liquid crystal panel for visible light in the darkened state can be set to 13.9%, 5.18%, 1.93%, 0.72%, 0.27%, 0.1%, 0.037%, 0.0139%, 0.0052%, 0.0019%, 0.00072% or 0.00027%; the transmittance of the liquid crystal panel (231) in the darkened state can be set to 0.07%, 0.04%, 0.02%, 0.01%, 0.007%, 0.004%, 0.002%, 0.001%, 0.0007%, 0.0004%, 0.0002% or 0.0001%; the transmittance of the liquid crystal panel for infrared rays in the darkened state can be set to 9.0 %, 5.0%, 2.5%, 1.5%, 1.3%, 1.0%, 0.8%, 0.6%, 0.5%, 0.4%, or 0.3%.

Optionally, the liquid crystal panel is a plurality of liquid crystal panels, and any number of liquid crystal panels in the plurality of liquid crystal panels can be selectively operated to switch from an idle state to a dimmed state. In this way, the observation window assembly can be manufactured at a lower cost through the combination of multiple liquid crystal panels, so that the realization of the above transmittance parameter requirements can be ensured through the selective combination of multiple liquid crystal panels in the darkened state.

Optionally, the laser processing is laser welding. The light sensor is configured such that the excitation signal is generated by detecting the strong light emitted from the high-temperature molten pool during laser welding and/or the reflected laser beam at the position to be welded.

According to another aspect of the present application, there is also provided a protective mask for laser processing protection, especially for laser welding protection, comprising:

mask shell;

The aforementioned automatic darkening filter installed on the mask shell, wherein, the laser protection sheet of the automatic darkening filter is located outside relative to the liquid crystal panel of the automatic darkening filter.

Using the above-mentioned technical means of this application, the automatic dimming filter can be designed to ensure automatic and effective protection of the human eye for laser welding operations with different power requirements, avoiding the need for protection with different light transmittance specifications due to the existing technology. Glasses may cause damage to human eyes caused by wearing glasses by mistake, which can further improve labor efficiency on the premise of improving the safety of human eye protection. In addition, since the laser protection sheet is built into the automatic darkening filter, the connection between the automatic darkening filter and the welding mask can still adopt the reliable connection method of the traditional existing technology, thereby avoiding the process of using the external laser protection sheet Accidental detachment from the center causes protection failure. In addition, the automatic darkening filter is designed to automatically change its light transmittance under the premise of providing laser protection for the appearance of high temperature molten pool and/or welding laser beam, so as to effectively isolate the adverse rays generated by the high temperature molten pool itself damage to the human eye. Compared with traditional laser protective glasses, it further improves the safety of human eye protection.

In addition, the automatic darkening filter of the present application is installed in the protective mask, and the welder wears the protective mask during operation, which can provide efficient protection for the welder's face and avoid burns on the human face by harmful rays.

Description of drawings

The principles and various aspects of the application will be more fully understood from the following detailed description in conjunction with the following drawings. It should be pointed out that the proportions of the drawings may be different for the purpose of clarity, but this will not affect the understanding of the present application. In the attached picture:

Fig. 1 is a perspective view schematically showing a protective mask according to an embodiment of the present application;

FIG. 2 is an exploded perspective view schematically illustrating an automatic darkening filter according to an embodiment of the present application;

Fig. 3 is a system block diagram, schematically shows an automatic darkening filter according to an embodiment of the present application;

Fig. 4 schematically shows a viewing window assembly according to an embodiment of the present application, wherein, for clarity only, the liquid crystal panel and the laser protection sheet of the viewing window assembly are shown separated from each other;

Fig. 5 schematically shows the stacking manner of various components in the observation window assembly according to another embodiment of the present application.

Detailed ways

In the various figures of the application, structurally identical or functionally similar features are indicated by the same reference numerals.

It should be clear to those skilled in the art that although laser welding protection is used for illustration in the following embodiments, the content described in these embodiments is also applicable to other laser processing such as laser cutting.

FIG. 1 schematically shows a protective mask 10 according to an embodiment of the present application, which includes a mask shell 100 and an automatic darkening filter 200 disposed on the mask shell 100 . The mask shell 100 can be connected with a headgear structure (hidden inside the mask shell 100 in the figure) via the knob structure 110 . The headgear structure is configured to be worn directly on the user's head such that the mask shell 100 is fixed relative to the user's head. The mask shell 100 is shaped to cover at least the user's face. An opening is formed at the front of the mask shell 100 . The auto-darkening filter 200 is mounted at the opening via a frame (not shown) from the inside of the inner hollow space surrounded by the mask shell 100 . On the outside of the auto-darkening filter 200, a transparent protective sheet may be installed in the mask shell 100 to provide the auto-darkening filter 200 with protection against abrasion from splashes.

When performing laser welding operations, the protective mask 10 is worn by the welding personnel in place to ensure that the face is adequately covered. The welder then uses a (not shown) hand-held laser welding device to target the part to be welded at the part to be welded. Then, the welder activates the hand-held laser welding device so that the parts to be welded are fused to each other under the action of the laser. During this process, the protective mask 10 according to the present application can not only protect the scattered laser light caused by the scattering of the laser light at the part to be welded, but also protect the face and eyes of the welder from the harmful rays produced by the high temperature molten pool during the welding process. s damage. In addition, the auto-darkening filter 200 according to the present application is designed to automatically switch from an idle state to a darkened state when a laser beam is emitted or when a high-temperature molten pool is generated. In the idle state of the automatic darkening filter 200, the visible light transmittance of the automatic darkening filter 200 is designed to be at least 30%, to ensure that the human eye can see through the automatic darkening filter 200 in the idle state The position to be welded, in particular the light beam produced by the aiming device of the hand-held laser welding device at the position to be welded can be observed. After the automatic darkening filter 200 is switched to its dimmed state, the visible light transmittance of the automatic darkening filter 200 can be designed to be selectively lower than 13.9%, 5.18%, 1.93%, 0.72%, 0.27% as required , 0.1%, 0.037%, 0.0139%, 0.0052%, 0.0019%, 0.00072%, 0.00027%, so as to ensure the safety of human eyes when observing the welding parts.

Fig. 2 schematically shows an automatic darkening filter 200 according to an example of the present application. The auto darkening filter 200 includes a mounting frame. For example, the installation frame includes an outer frame 201 facing outward and an inner frame 202 facing inward after the automatic darkening filter 200 is installed on the protective mask 10 . The outer frame 201 and the inner frame 202 can be attached to each other. For example, attached together via adhesive and/or via structures that can be plugged into each other (a pin as shown and a receptacle for receiving the pin, etc.).

As shown in FIG. 3 , the automatic darkening filter 200 includes a control unit 206 , an observation window assembly 230 , a light sensor 220 , a photoelectric conversion element 210 and a battery 240 , wherein the observation window assembly 230 includes a liquid crystal panel 231 and a laser protection sheet 232 . The liquid crystal panel 231 is arranged on the inner side with respect to the laser protection sheet 232 . That is to say, after the automatic darkening filter 200 is installed on the protective mask 10 and the protective mask 10 is worn by the user, external light or rays can only pass through the laser protection sheet 232 first, and then pass through the liquid crystal panel 231 in the order Enter the hollow interior of the protective mask 10. The control unit 206 may be powered by a battery 240, such as a button cell. In addition, the control unit 206 includes a control circuit electrically connected to the light sensor 220 , the photoelectric conversion element 210 , and the liquid crystal driving circuit 231 a for driving each liquid crystal array of the liquid crystal panel 231 . A plurality of apertures 207 are formed in the outer frame 201 . According to an embodiment of the present application, there may be, for example, four apertures 207 , of which two are shown in FIG. 2 and the other two are hidden. These apertures 207 are used to mount a corresponding number of light sensors 220 . The light sensor 220 is configured to be able to detect the strong light spot generated at the position to be welded by the high-energy laser beam produced by the welding laser or the strong light (for example, infrared light component) emitted by the resulting high-temperature molten pool and/or due to The laser beam is reflected at the position to be welded, and an electrical signal is generated and provided to the control unit 206 . The control unit 206 is configured to activate the liquid crystal drive circuit 231a correspondingly after receiving the electrical signal, so that the light transmittance of the liquid crystal panel 231 changes accordingly when the liquid crystal arrays are energized. The photoelectric conversion element 210 is configured to receive the strong light generated by the high-temperature molten pool and convert the received strong light into electrical energy, which can be stored in the battery 240 for later use by the driving control unit 206 .

As further shown in FIG. 2 , openings 204 and 205 are respectively formed in the outer frame 201 and the inner frame 202 , which are aligned with each other after the mounting frame of the automatic darkening filter 200 is assembled in place. The viewing window assembly 230 is received within the mounting frame such that a substantial area of the viewing window assembly 230 is exposed through the openings 204 and 205 aligned with each other. An opening 203 is also formed in the outer frame 201, so that when the photoelectric conversion element 210 is installed in the installation frame, most of the area of the photoelectric conversion element 210 can be exposed through the opening 203, so as to convert the received light energy into electrical energy. The auto darkening filter 200 may also include a control panel 250 , which may be located next to the viewing window assembly 230 , for example. In the illustrated embodiment, the control panel 250 is aligned with the photoelectric conversion element 210 or its opening 203 in the assembled mounting frame. The control panel 250 can be a touch screen panel, for example, so that it is convenient for the user to input instructions to set various parameters of the liquid crystal panel 231 via the control unit 206, such as the shading number (for example, the light transmittance of the liquid crystal panel in a darkened state), the response Time (that is, the time for the LCD panel to switch from the idle state to the dimmed state), etc.

According to an embodiment of the present application, the laser protection sheet 232 may include a substrate. For example, the substrate can be made of polycarbonate material. According to the present application, the laser protection sheet 232 can be manufactured by reflecting laser light for energy attenuation or absorbing laser light for energy attenuation. For example, in the way of energy attenuation by reflecting laser light, the substrate surface of the laser protection sheet 232 can be plated or coated with a layer of laser beam reflective coating, for example, using evaporated zirconia (ZrO ₂ ) and Silicon dioxide (SiO ₂ ) film, so that the laser energy irradiated on the laser protection sheet 232 can be mostly reflected, without, or only harmless to the naked eye, or will not cause any damage to the liquid crystal array in the downstream liquid crystal panel 231 Laser light at damaging energy levels is able to transmit through the substrate of the laser shield 232 . For another example, in the method of energy attenuation by absorbing laser light, the substrate of the laser protection sheet 232 can be doped with an absorber that can scatter the laser beam to attenuate its energy during the manufacturing process, such as 532 absorber, IR1064 Absorbent, and IR10600 absorbent, etc. Of course, those skilled in the art should understand that the above two methods can also be used simultaneously to manufacture the laser protection sheet 232 .

According to an embodiment of the present application, the laser protection sheet 232 is manufactured so that the protection level against laser radiation, for example, the transmittance of laser energy at a wavelength of 1064 nm or 1070 nm can reach at least an order of 10 ⁻³ to 10 ⁻⁶ . It should be clear that the laser protection sheet 232 used in this application is also configured so that the laser energy transmittance for laser welding in other wavelength ranges should also reach the order of 10 ⁻³ to 10 ⁻⁶ . In addition, the laser shielding sheet 232 is manufactured to have a transmittance of at least 30% for visible light. In a preferred embodiment, the laser protection sheet 232 is manufactured with a high transmittance for visible light to ensure that the user can observe the aiming spot of the handheld laser welding device through the automatic darkening filter 200 in an idle state.

As shown in Figure 4, the reference sign L1 and the solid line arrow represent the laser beam scattered by the workpiece to be welded during laser welding, and the reference sign L2 and the dotted line arrow represent other harmful effects produced by the high temperature molten pool during laser welding. Rays. According to the automatic darkening filter 200 of the present application, when laser welding is performed, the laser beam L1 is blocked by the laser protection sheet 232 and cannot harm human eyes. In addition, since this application considers that welding personnel must be able to observe the welding site or the laser aiming spot when performing welding operations, it is difficult for the transmittance of the laser protection sheet 232 to completely block other harmful rays L2 produced during laser welding. (Mainly harmful rays of visible light). Therefore, other harmful rays L2 are blocked by the liquid crystal panel 231 in the darkened state. In this way, the automatic darkening filter 200 of the present application can provide welding personnel with more comprehensive protection. Especially, after the welder wears the protective mask 10 according to the present application, he can conveniently observe the outside world through the automatic darkening filter 200 in the idle state when the laser welding has not yet started, but when the laser welding is actually performed and the high temperature The moment the molten pool is formed, the auto-dimming filter 200, especially its liquid crystal panel 231, automatically switches to a darkened state, so that the auto-dimming filter 200 can simultaneously provide protection against the laser beam L1 and other harmful rays L2. In addition, the mask shell 100 of the protective mask 10 can also provide welding personnel with protection against harmful radiation on the face or head.

According to the embodiment of the present application, when the liquid crystal panel 231 of the automatic darkening filter 200 is in the darkened state, the average transmittance for visible light can respectively reach 13.9%, 5.18%, 1.93%, 0.72%, 0.27%, 0.1%, 0.037%, 0.0139%, 0.0052%, 0.0019%, 0.00072%, 0.00027%; the average transmittance for far ultraviolet rays can also reach 0.07%, 0.04%, 0.02%, 0.01%, 0.007%, 0.004%, 0.002%, 0.001%, 0.0007%, 0.0004%, 0.0002%, 0.0001%; the average transmittance for infrared rays can also reach 9.0%, 5.0%, 2.5%, 1.5%, 1.3%, 1.0%, 0.8%, 0.6 %, 0.5%, 0.4%, 0.3%. The above parameters can be selectively set using the control panel 250 .

In order to ensure that the liquid crystal panel 231 can meet the above requirements, according to an embodiment of the present application, the liquid crystal panel 231 may be a combination of one, two or more liquid crystal panels. The combination of liquid crystal panels is driven by the liquid crystal driving circuit 231a, so that one, two or any number of liquid crystal panels in the combination of liquid crystal panels can work selectively, so that the above mentioned improvements can be achieved respectively in the darkened state. and transmittance. In addition, the transmittance of a single liquid crystal panel in the liquid crystal panel assembly can also be individually adjusted as required. In this way, according to the present application, the required transmittance parameters can also be achieved by using the selective combination of multiple liquid crystal panels with lower parameter requirements and therefore lower cost, so as to realize the technical solution of the present application at a lower cost.

In the embodiment shown in FIG. 4 , the liquid crystal panel 231 is arranged downstream of the laser protection sheet 232 ; In the context of the present application, terms referring to "upstream" or "downstream" refer to the objects that are first reached by a laser beam such as L1 or harmful rays such as L2 as those that are upstream and those that arrive later are those that are downstream. In fact, due to the installation of the transparent protective sheet in the mask shell 100, the applicant of the present application has found that arranging the laser protective sheet 232 integrated in the auto-dimming filter upstream of the liquid crystal panel 231 is also sufficient for laser welding. protective effect, e.g. when the laser beam does not directly strike the auto-darkening filter.

According to an embodiment of the present application, the liquid crystal panel 231 and the laser protection sheet 232 can be attached to each other in the observation window assembly 230, for example, in a face-to-face contact mode, and static electricity or such as can be used between the contact surfaces. Adhesives such as water glue or optical glue to ensure a firm fit.

While specific embodiments of the application are described in detail herein, they are presented for purposes of illustration only and should not be considered limiting of the scope of the application. In addition, it should be clear to those skilled in the art that the various embodiments described in this specification can be used in combination with each other. Various alternatives, changes and modifications can be devised without departing from the spirit and scope of the application.

Claims (11)

1. An automatic darkening filter (200) for laser machining protection, comprising:

a mounting frame; and

a window assembly (230) and a light sensor (220) mounted in the mounting frame, the light sensor (220) being configured to generate an excitation signal after detecting intense light generated during laser processing, the window assembly (230) comprising a laser protection sheet (232) on a side facing a direction of intense light generation during laser processing and a liquid crystal panel (231) located upstream or downstream of the laser protection sheet (232),

the automatic dimming filter (200) further comprises a control unit (206), the control unit (206) is electrically connected with the light sensor (220), and after receiving the excitation signal, the control unit (206) controls the liquid crystal panel (231) to switch from an idle state to a dimming state, wherein the transmittance of the liquid crystal panel (231) for visible light, far ultraviolet rays and infrared rays in the idle state is higher than the transmittance for visible light, far ultraviolet rays and infrared rays in the dimming state.

2. The automatic darkening filter (200) of claim 1, wherein the transmissivity to laser light of the laser guard sheet (232) is configured such that laser light passing through the laser guard sheet (232) cannot damage the liquid crystal array of the downstream liquid crystal panel (231).

3. The automatic darkening filter (200) of claim 2, wherein the laser guard sheet (232) is configured to provide a laser energy transmission of at least 10 for at least 1064nm or 1070nm wavelengths ^-3 ～10 ^-6 On the order of (2).

4. The automatic darkening filter (200) of claim 3, wherein the laser protection sheet (200) is configured to have a transmittance for visible light of at least 30%.

5. The automatic darkening filter (200) of claim 1, wherein the liquid crystal panel (231) is bonded to the laser protection sheet (232).

6. The automatic darkening filter (200) of any of claims 1 to 5, further comprising a control panel (250) to set the transmittance of the liquid crystal panel (231) for visible light in a darkened state to 13.9%, 5.18%, 1.93%, 0.72%, 0.27%, 0.1%, 0.037%, 0.0139%, 0.0052%, 0.0019%, 0.00072%, or 0.00027%; setting the transmittance of the liquid crystal panel (231) for extreme ultraviolet rays in a darkened state to be 0.07%, 0.04%, 0.02%, 0.01%, 0.007%, 0.004%, 0.002%, 0.001%, 0.0007%, 0.0004%, 0.0002% or 0.0001%; and the transmittance of the liquid crystal panel (231) for infrared rays in a darkened state is set to 9.0%, 5.0%, 2.5%, 1.5%, 1.3%, 1.0%, 0.8%, 0.6%, 0.5%, 0.4% or 0.3%.

7. The automatic dimming filter (200) of claim 6, wherein the liquid crystal panel (231) is a plurality of liquid crystal panels (231), any number of the plurality of liquid crystal panels (231) being selectively operable to switch from an idle state to a dimmed state.

8. The automatic darkening filter (200) of claim 7, wherein the laser machining is laser welding.

9. The automatic darkening filter (200) of claim 8, wherein the light sensor (220) is configured such that the excitation signal is generated by its detection of intense light emitted from a high temperature melt pool during laser welding and/or by a laser beam reflected at the site to be welded.

10. A protective mask (10) for laser machining protection, comprising:

a mask shell (100);

the automatic darkening filter (200) according to any one of claims 1 to 9 mounted on the mask shell (100), wherein the laser protection sheet (232) of the automatic darkening filter (200) is located outside with respect to the liquid crystal panel (231) of the automatic darkening filter (200).

11. The protective mask (10) according to claim 10, wherein the laser machining is laser welding.