WO2018218748A1

WO2018218748A1 - Auto-darkening welding filter and auto darkening welding helmet

Info

Publication number: WO2018218748A1
Application number: PCT/CN2017/092794
Authority: WO
Inventors: 黄上游
Original assignee: 武汉威和光电股份有限公司
Priority date: 2017-06-02
Filing date: 2017-07-13
Publication date: 2018-12-06
Also published as: CN107242935A; CN107242935B

Abstract

An auto-darkening welding filter (1), comprising a filter frame (11), a liquid crystal piece (13), a photoelectric sensor (15) and a drive circuit (17) driving the liquid crystal piece (13); both the liquid crystal piece (13) and the photoelectric sensor (15) are provided on the filter frame (11); the photoelectric sensor (15) is provided on one side, close to the eyes, of the liquid crystal piece (13); the photoelectric sensor (15) acquires optical signals transmitted by means of the liquid crystal piece (13) and feeds same back to the drive circuit (17); the drive circuit (17) controls the light transmittance of the liquid crystal piece (13) according to the signals fed back from the photoelectric sensor (15), thereby forming a closed-loop control system, such that the illuminance of light passing through the auto-changing shade auto-darkening welding filter (1) is constant. The auto-darkening welding filter (1) constantly performs feedback regulation by means of the closed-loop control system, thereby preventing the situation in which the darkening welding filter becomes too dark or too bright.

Description

Automatic dimming welding filter and automatic dimming welding mask

Technical field

The invention relates to the technical field of electric welding protection, in particular to an automatic dimming welding filter and an automatic dimming welding mask.

Background technique

A welding arc is often generated during metal welding. A welding arc is a gas discharge phenomenon that occurs between an electrode and a weldment. It contains a large amount of high-intensity visible light, infrared rays, and ultraviolet rays. High-intensity visible light, infrared rays, and ultraviolet rays are used. Light radiation can damage the welder's eyes.

The luminosity of the visible light in the welding arc is 10,000 times larger than the illuminance of the human eye. The strong visible light will burn the retina and cause retinitis. At this time, the welder will feel pain in the eyes, visual film, and center. Dark spots, even temporary blindness, such as long-term repeated effects, vision will gradually decline.

In the welding arc, the damage of the infrared rays to the eyes is a chronic process. After the lens of the eye absorbs excessive infrared rays for a long time, the elasticity is deteriorated, the adjustment is difficult, and the vision is reduced. In severe cases, the crystal turbidity may be caused and the vision is impaired. When the ultraviolet rays are irradiated to the human eye in the welding arc, the cornea and conjunctiva are inflamed, and the "electro-optic ophthalmia" is listed as the second largest occupational disease other than pneumoconiosis. Ultraviolet rays and infrared rays may cause permanent damage to the human eye. hurt.

The welding mask is used to help the welder protect the occupational hazards from welding, helping them to protect the eyes and accurately position and efficiently weld during the welding process. The early welding mask was equipped with a piece of black glass on the hand-held protective mask to protect the eyes, but it was necessary to cover the eyes at the moment of arcing. If the welder did not move in time, it would easily burn the eyes and affect the welding quality.

With the advancement of technology, an automatic dimming welding mask has appeared, and an automatic dimming welding mask is provided with an automatic darkening filter (ADF) to achieve an automatic dimming function. The ADF provides the welder with a bright and clear view before starting the arc, through the ADF. The solder joint can be accurately positioned. Once the arc is started, the ADF can be automatically and quickly dimmed, which can reduce the intensity of visible light and effectively block the ultraviolet and infrared rays in the arc to prevent the eyes from being burned.

The conventional ADF generally includes a lens frame, a liquid crystal film disposed on the frame, an arc sensor disposed outside the frame, and a driving circuit. The ADF mainly utilizes a characteristic that the arrangement of the liquid crystal molecules changes with the applied voltage of the driving circuit. Control of light transmittance. Before the arcing, the ADF is in a bright state, and the welder can prepare for welding through the ADF. When the welding arc occurs, the arc sensor first senses the arc generated by the welding, and then transmits the signal to the driving circuit, and the driving circuit applies a voltage to the liquid crystal film, thereby The transmittance of external light incident into the ADF is adjusted, and the ADF is changed from a bright state to a dark state, thereby preventing the welder's eyes from being damaged by optical radiation.

At present, most of the ADF, the arc sensor is only used to judge whether there is a welding arc currently, and then according to the set liquid crystal driving conditions, an appropriate driving voltage is applied to both ends of the liquid crystal film to achieve a preset transmittance. A small part is the ADF which can automatically adjust the transmittance. If the welding environment changes, the arc sensor senses the welding arc of different brightness, and transmits different strong and weak signals to the driving circuit, and then the driving circuit controls the liquid crystal adjustment. To different light transmittance. However, in the above two ADFs, the transmittance of the liquid crystal film is determined by the arc of the arc induced by the arc sensor. This control mode is one-way open-loop control, and there is no feedback process, and the adjustment effect of the transmittance of the liquid crystal film cannot be evaluated. It may be that the transmittance of the ADF is too high, it is still high-intensity visible light, or it may damage the welder's eyes, or the transmittance of the ADF is too low, the field of view is too dark, and the welder cannot see the solder joints, thus affecting the efficiency of the welding work. .

In addition, the existing arc sensor is generally small because of its high price. The common ones are 1.5mm×1.5mm or 3mm×3mm, but in the welding process, hot particles, hot liquid or molten metal are often generated. Once the welding slag splashes onto the arc sensor, it may block or even destroy the arc sensor, so that the signal of the arc sensor is affected. Some ADFs also protect the arc sensor and the liquid crystal film through the outer protective sheet to isolate the welding arc, but due to the arc The relative area of the sensor is small. If the welding slag splashes onto the outer protective sheet or there is an obstruction between the solder joint and the outer protective sheet, it is also easy to cover the arc sensor, and the arc sensor loses its effect, causing interference to the arc sensor inducing the arc welding process. .

Therefore, it is urgent to develop a new automatic dimming welding filter to solve the above problems.

Summary of the invention

The object of the present invention is to provide an automatic dimming welding filter for solving the technical problem that the conventional automatic dimming welding filter cannot evaluate the adjustment effect of the transmittance of the liquid crystal sheet due to the one-way open-loop control mode. .

In order to achieve the above object, the present invention provides the following technical solution: an automatic dimming welding filter includes a lens frame, at least one liquid crystal panel, a photoelectric sensor, and a driving circuit for driving the liquid crystal panel, the liquid crystal panel and the photoelectric The sensor is disposed on the frame, and the photoelectric sensor is disposed on a side of the liquid crystal film near the human eye, and the photoelectric sensor collects an optical signal transmitted through the liquid crystal chip, and converts the electrical signal into an electrical signal and feeds back to the a driving circuit, the driving circuit controls the transmittance of the liquid crystal panel according to an electrical signal fed back by the photoelectric sensor to form a closed loop control system, so that the illuminance of the light passing through the automatic dimming filter is 0.05- The range of 1.0 lux is constant.

Preferably, the photosensor is an amorphous silicon solar cell.

Amorphous silicon solar cells are easy to be large-area and low in cost. Compared with crystalline silicon solar cells, which are suitable for high light conditions or ultraviolet light, amorphous silicon solar cells can receive weak light signals well, and amorphous silicon The spectral response curve of the solar cell is closer to the human visual function and closer to the human eye.

Preferably, the photosensor has a size ranging from 5 mm*50 mm to 25 mm*120 mm.

The area of the photoelectric sensor is much larger than that of the existing arc sensor. Even if there is slag splash or obstruction blockage, it will not have a great influence on the photoelectric signal received by the photoelectric sensor. At the same time, the photoelectric sensor has a large area and can receive more. The optical signal, which enhances the signal strength, also partially offsets the influence of the weakening of the optical signal caused by the rear of the photoelectric sensor and the difficulty of processing.

Preferably, the auto-dimmer welding filter further includes a first filter disposed on the frame for attenuating ultraviolet radiation and infrared light, the first filter being located at the liquid crystal film away from the person One side of the eye.

The first filter can effectively prevent ultraviolet rays and infrared rays from entering the auto-dimmering filter to damage the optical components and enhance the protection of the welder's eyes.

Preferably, the auto-dimming welding filter further includes a diffusing plate disposed on the frame for reducing the influence of different incident angles of light on the optical signal, the diffusing plate being located at the liquid crystal panel and the photoelectric Between the sensors.

The astigmatism plate reduces the angular dependence of the light transmittance, so that the automatic dimming welding filter can accurately and automatically change the various point, line and surface light sources that may exist during the welding process, thereby further protecting the welder's eyes.

Preferably, the auto-dimmer welding filter further includes a second filter disposed on the frame for correcting a spectral response curve of the photosensor to match a human visual function, the second filter A light sheet is located between the diffusing plate and the photosensor.

The second filter corrects the spectral response curve of the photosensor to match the human visual function, so that the illuminance value measured by the photosensor through the received optical signal is consistent with the perception of the human eye, so that the photoelectric sensor can replace the welder The eyes can judge the strength of the light and can better protect the eyes.

Preferably, the second filter is any one of a coated filter, an absorptive filter or a colored glass.

Preferably, the automatic dimming filter further includes an auxiliary photosensor disposed outside the frame, the auxiliary photosensor collecting an optical signal incident on the frame and feeding back to the driving circuit. The driving circuit controls the transmittance of the liquid crystal panel according to the signal fed back by the auxiliary photosensor, and realizes the transition of the auto-dimming welding filter from a bright state to a dark state.

The auxiliary photoelectric sensor pre-darks the liquid crystal film at the moment of arcing, and then the photoelectric sensor continues the feedback control process according to the optical signal transmitted through the liquid crystal film, thereby reducing the influence of the hysteresis on the photoelectric sensor due to factors such as linear amplification of the circuit, and performing auxiliary judgment. Make the closed-loop control system more precise.

Preferably, the auxiliary photosensor is a photoresistor or a photodiode.

The invention also provides an automatic dimming welding mask, the automatic dimming welding mask comprising An automatic dimming welding filter according to any of the above.

Compared with the prior art, the automatic dimming welding filter and the automatic dimming welding mask of the present invention have the following advantages:

1. The present invention continuously performs feedback adjustment through a closed loop control system until the auto-dimming welding filter adjusts to a dark state light-shielding number corresponding to the illuminance of the welding light, so that the light transmitted through the automatic dimming welding filter The illuminance is constant, effectively preventing the auto-dimming welding filter from being too dark, the welder may not be able to see the welding environment or the auto-dimming welding filter is too bright, and may still damage the welder's eyes;

2. The automatic dimming welding filter provided by the invention adopts a closed-loop control system, which improves the reliability and stability of the automatic dimming welding filter, and is easier to achieve an optimal working state.

DRAWINGS

Various other advantages and benefits will become apparent to those skilled in the art from a The drawings are only for the purpose of illustrating the preferred embodiments and are not to be construed as limiting. In the drawing:

1 is a schematic structural view of an automatic dimming welding filter according to a first preferred embodiment of the present invention;

Figure 2 is a diagram showing the control relationship of the automatic dimming filter of Figure 1;

Figure 3 shows a correction curve of the second filter of Figure 1;

Fig. 4 is a view showing the structure of an automatic dimming welding filter of a second preferred embodiment of the present invention.

DRAWINGS

11-frame, 12-first filter,

13-liquid crystal, 14-dispersive plate,

15-photoelectric sensor, 16-second filter,

17-drive circuit, 18-auxiliary photoelectric sensor.

detailed description

The present invention provides many applicable inventive concepts that can be embodied in a large number of contexts. The specific embodiments described in the following embodiments of the present invention are merely illustrative of the specific embodiments of the invention, and are not intended to limit the scope of the invention.

First, the terms related to the present invention are explained:

The wavelength range of 380 nm to 780 nm in the electromagnetic spectrum is defined as the visible light range, that is, the range of light radiation that can be detected by the human eye, the wavelength range of wavelength less than 380 nm is defined as the ultraviolet wavelength band, and the wavelength range of wavelength greater than 780 nm is defined. For the infrared band.

According to the national industry standard GB/T 3609.2-2009 "Professional eye and face protection welding protection Part 1: automatic dimming welding filter", the definition of automatic dimming filter is: when the arc is generated instantaneously, Automatically converts the shading number from a lower value (bright shading number) to a higher value (dark shading number) protective filter.

The automatic dimming welding filter is divided into a manually set level automatic dimming welding filter and an automatic setting level automatic dimming welding filter, wherein the manually set level automatic dimming welding filter is Refers to the protection filter that automatically converts the level from a lower value (bright state level) to a preset higher value (dark state level) at the moment of welding arcing; automatically sets the level of automatic dimming filter The light microscope refers to an automatic dimming welding filter with an automatic conversion function, which can automatically adjust the dark state shading number according to the intensity of the arc irradiance generated at the moment of welding arcing.

The shading number N is the darkness number of the auto-dimming welding filter, and the relationship between the shading number N and the visible light transmittance τ _v is as shown in the formula (1).

The visible light transmittance in the formula (1) is the ratio of the outgoing light flux passing through the filter to the incident light flux, and the visible light transmittance (ie, the visible light transmittance) corresponding to the different light-shielding numbers can be derived from the formula (1), as shown in Table 1. Show.

Table 1 shows the visible light transmittance corresponding to different shading numbers

It can be seen from Table 1 that for different shading numbers, the visible light transmittance is very different, and the shading number is a lower value. For example, when the shading number is 3, the visible light transmittance is higher, reaching 10 ^-1 , that is, the light is attenuated to ten. One of the points, indicating that there are many visible light transmitted through the filter, the welder's field of view is brighter; the shading number is higher, such as the shading number is 13, the visible light transmittance is very low, reaching 10 ^-6 , that is, the light is attenuated. One in a million, indicating that the visible light transmitted through the filter is small, which can hinder the damage of the high-intensity visible light to the welder's eyes. In the welding industry, according to different welding environments, the shading number of the filter after arcing is preferably 9-13.

According to the national industry standard GB/T 3609.2-2009 "Professional eye and face protection welding protection part 1: automatic dimming welding filter", the light state of the automatic light-shearing filter before the production of the arc is made. The shading number corresponding to the maximum value, the shading number of the dark state is the shading number corresponding to the lower light transmittance value achieved by the auto-dimmering welding filter after the welding arc is generated.

Automatically set the level of automatic dimming filter to meet the following requirements:

The dark state shading number N depends on the illuminance E _V , which is the luminous flux per unit area of the visible light, and is used to indicate the intensity of the illumination and the amount of illumination of the surface area of the object. The relationship between the dark state shading number and the illuminance is as shown in equation (2).

N=2.93+2.25lg(E _V ) Equation (2)

In the formula (2), the illuminance E _v is an illuminance value of the front surface of the incident surface of the automatic dimming filter, and the unit is lx (lux).

The illuminance value corresponding to different dark state shading numbers can be derived from equation (2), as shown in Table 2.

Table 2 illuminance values corresponding to different dark state shading numbers

暗态遮光号/NDark state shading number / N	照度Ev/lxIlluminance Ev/lx
88	180180
99	500500
1010	14001400
1111	39003900
1212	1070010700
1313	3000030000
1414	8300083000

It can be seen from Table 2 that in the welding environment with different illumination, the automatic setting of the automatic dimming filter needs to be automatically changed to different dark state shading numbers to achieve the purpose of protecting the eyes. When the low value is 180lx (lux), the automatic dimming filter should automatically adjust the dark state shading number to 8, and according to the data in Table 1, when the dark state shading number is 8, the visible light transmittance is 0.00061-0.0016. The visible light illumination through the automatic dimming filter should be in the range of 0.1098-0.288 lux; when the illumination light illumination is higher, such as 30,000 lx (lux), the automatic dimming filter should automatically adjust the dark state. The shading number is 13, and according to the data in Table 1, when the dark state shading number is 13, the visible light transmittance is 0.0000044-0.000012, and the visible light illumination passing through the auto-dimming welding filter should be in the range of 0.132-0.360 lux.

Therefore, it is calculated that when the illuminance of the welding light is in the range of 180-83000lx, the automatic dimming filter should be automatically adjusted to the corresponding dark state opacity, and the visible illuminance through the automatic dimming filter should be It remains constant over the 0.1-0.4 lux range. What needs to be explained is that Considering the difference between the human eye and the individual's preference, it is possible to allow adjustment of ±1 color number within the standard range, so the visible light illumination through the automatic dimming filter should be 0.132/2.68-0.360*2.68 That is, it remains constant in the range of 0.05 to 1.0 lux.

The invention is further described below in conjunction with the drawings and specific embodiments.

Example 1

As shown in FIG. 1 and FIG. 2, the embodiment provides an automatic dimming welding filter, which is an automatically set grade automatic dimming welding filter.

The auto-dimmer welding filter includes a lens frame 11, a first filter 12, a liquid crystal panel 13, a diffusing plate 14, a photosensor 15, a second filter 16, and a driving circuit 17 for driving the liquid crystal panel 13. The first filter 12, the liquid crystal panel 13, the diffusing plate 14, the second filter 16, and the photosensor 15 are sequentially disposed in the frame 11, and the photosensor 15 is disposed in the vicinity of the light irradiation direction. On one side of the human eye, the liquid crystal cell 13 and the photosensor 15 are respectively connected to the drive circuit 17.

The frame 11 is used for mounting the optical components and fixing the position thereof, so that the automatic dimming welding filter is integrally mounted on the automatic dimming welding mask.

The first filter 12 is for attenuating the ultraviolet radiation and the infrared light, and is located at the outermost side of the auto-dimming welding filter, that is, the side of the liquid crystal panel 13 away from the human eye. Specifically, the first filter 12 is a UV/IR filter, and the first filter 12 has the same ultraviolet and infrared blocking regardless of the environment of the welder or whether the driving circuit 17 operates. The ability to effectively prevent UV and IR from entering the auto-dimmering filter to damage the optics and enhance the protection of the welder's eyes.

The liquid crystal cell 13 is based on the principle of a liquid crystal light valve which controls the phase retardation of light by controlling the refractive index of liquid crystal molecules by voltage.

Specifically, the liquid crystal light valve is composed of a liquid crystal cell with an alignment film and a polarizing plate disposed on both sides of the liquid crystal cell. When no voltage is applied to the liquid crystal light valve, the liquid crystal molecules in the liquid crystal cell are rotatably arranged in a direction restricted by the alignment film, parallel to the plane of the polarizing plate, and produce an optical rotation effect on the passing light, so that the linear polarization of the polarizing plate is transmitted. After the incident light passes through the liquid crystal cell, it can be emitted from a polarizing plate perpendicular to the incident polarizing plate; when a voltage is applied to the liquid crystal light valve, the liquid crystal in the liquid crystal cell The molecules are arranged at an oblique angle on the original horizontal plane, and the optical rotation disappears. The polarized light transmitted through the polarizing plate cannot be emitted from the polarizing plate perpendicular to the incident polarizing plate. The larger the voltage, the larger the tilt angle of the liquid crystal molecules and the more perpendicular to the polarization. The horizontal plane in which the sheets are placed, the lower the transmittance to light.

The number of the liquid crystal cells 13 is at least one. In the embodiment, the number of the liquid crystal cells 13 is preferably two. Of course, in order to improve the optical characteristics of the auto-dimming welding filter, the liquid crystal film 13 can also be three pieces.

In this embodiment, the liquid crystal panel 13 is a twisted nematic (TN) type liquid crystal panel. Of course, the liquid crystal panel 13 may also be other types of liquid crystal wafers, such as vertical alignment (Vertical Alignment, VA). A liquid crystal panel, an In-Plane Switching (IPS) type liquid crystal cell, a Fringe Filed Switching (FFS) type liquid crystal cell, or the like, as long as the liquid crystal molecules can be rotated by an electric signal.

The diffusing plate 14 is configured to reduce the influence of different incident angles of light on the optical signal. Without the diffusing plate 14, the incident light is irradiated onto the automatic dimming welding filter with the same illumination intensity and different incident angles, and the light intensity received by the automatic dimming welding filter is different, and the light transmittance is followed. The change may be a strong light intensity, but the light transmittance is low, and the eye of the welder can still be damaged. Therefore, the present invention provides that the diffusing plate 14 is disposed on the liquid crystal panel 13 and the second filter 16 Maintaining the transmittance of the auto-dimming welding filter within a range of a solid angle of 15° between the incident light and the normal of the auto-darkening filter, which does not change with the change of the incident angle, that is, reduces the penetration. The angular dependence of the light rate enables the automatic dimming filter to accurately and automatically light the various point, line and surface light sources that may exist during the welding process, thereby further protecting the welder's eyes.

The photosensor 15 is preferably an amorphous silicon solar cell. Amorphous silicon solar cells are generally formed by decomposing and depositing silane gas by a high-frequency glow discharge method. Due to the low external deposition temperature, a film of about 1 μm thick can be deposited on glass, stainless steel plates, ceramic plates, and flexible plastic sheets, which is easy to be large in area, low in cost, and mostly adopts a p in structure. In order to improve efficiency and improve stability, it is sometimes made into a three-layer P in multi-layer laminated structure, or a transition layer is inserted.

The working principle of amorphous silicon solar cells is based on the photovoltaic effect. Amorphous silicon photovoltaic cells are essentially a large-area PN junction. When incident light illuminates the surface of the P region, if photon energy Greater than the forbidden band width of amorphous silicon, an "electron-hole" pair is generated for each photon absorbed in the P region. The more photons absorbed on the surface of the P region, the more "electron-hole" pairs are excited, and the fewer photons flow to the inside, the difference in concentration forms a natural tendency to diffuse from the surface to the inside, due to the electric field in the PN junction. The direction is from the N region to the P region, so the "electron-hole" pair diffused to the vicinity of the PN junction will be separated, the photogenerated electrons will be pushed to the N region, and the photogenerated holes will be left in the P region, thereby causing the N region to be negatively charged. The P zone is positively charged to form a photo-generated electromotive force. If the P and N regions are connected together by wires, a photocurrent will pass through the circuit and be converted into an electrical signal by the optical signal. Therefore, under the irradiation of incident light, the current generated by the amorphous silicon solar cell will increase as the light intensity increases, and the optical signal is converted into an electrical signal.

As shown in FIG. 2, the photosensor 15 collects an optical signal transmitted through the liquid crystal panel 13 and converts it into an electrical signal, which is fed back to the driving circuit 17 after being amplified, and the driving circuit 17 is based on the photosensor 15 The feedback electrical signal controls the light transmittance of the liquid crystal cell 13, forming a closed loop control system such that the illuminance of the light transmitted through the auto-dimming welding filter is constant. The closed loop control system is a negative feedback control system.

Specifically, the photosensor 15 collects an optical signal transmitted through the liquid crystal panel 13. If the soldering light is visible light having a high illuminance, the optical signal transmitted through the liquid crystal panel 13 is strong, and the photosensor 15 will After the strong optical signal is converted into a strong electrical signal and fed back to the driving circuit 17, the driving circuit 17 applies a large voltage to the liquid crystal panel 13 to reduce the light transmittance of the liquid crystal panel 13. Rate, light passing through the liquid crystal panel 13 is reduced;

If the transmittance of the liquid crystal panel 13 is too low, that is, the dark state light shielding number is too high, the photosensor 15 collects a very weak optical signal, and converts it into an electrical signal and feeds back to the driving circuit 17 The driving circuit 17 reduces the applied voltage, increases the light transmittance of the liquid crystal panel 13, and reduces the dark state shading number;

If the transmittance of the liquid crystal panel 13 is too high, that is, the dark state light shielding number is too low, the photosensor 15 collects a still strong optical signal, and converts it into an electrical signal and feeds back to the driving circuit. 17, the driving circuit 17 will continue to increase the applied voltage, reduce the transmittance of the liquid crystal panel 13, and increase the dark state shading number;

Through the above-mentioned continuous feedback closed loop control system until the automatic dimming welding filter Adjusting to the dark state opacity corresponds to the illuminance of the welding light, so that the illuminance of the light passing through the automatic dimming filter is constant, effectively preventing the auto-dimming welding filter from being too dark, and the welder may not see the welding environment or The auto-dimming welding filter is too bright, which may still damage the welder's eyes, improve the reliability and stability of the auto-dimming welding filter, and make it easier to achieve the best working condition.

It should be noted that the closed-loop control system adjusts the transition time of the automatic dimming filter from the bright state to the dark state very short, which may be only between one thousandth of a second to one ten thousandth of a second, or even shorter. Therefore, the impact of the conversion time on the welder can be ignored.

In this embodiment, the size of the photosensor 15 ranges from 5 mm*50 mm to 25 mm*120 mm. The area of the photosensor 15 is much larger than the existing arc sensor having a size of 1.5 mm×1.5 mm or 3 mm×3 mm, and the photosensor is not received by the photosensor 15 even if there is spatter splash or obstruction blocking. The photoelectric sensor 15 has a large area, can receive more optical signals, enhances the signal intensity, and partially cancels the influence of the light signal weakening and the processing difficulty caused by the rear of the photoelectric sensor 15. .

The second filter 16 is configured to correct the spectral response curve of the photosensor 15 to match the human visual function.

The human eye has different sensitivities to light of different wavelengths. Different human eyes often have different sensitivities to light of various wavelengths. Even with the same radiant power, light of different envelopes is generated for the human eye. The brightness perception is different. The International Commission on Illumination (CIE) has given a lot of experiments and statistics to give the relative sensitivity of the human eye to the brightness perception of different wavelengths of light, called the spectral light efficiency curve, also known as the human visual function.

As shown in FIG. 3, the photosensor 15 is an amorphous silicon solar cell whose spectral response curve is close to a human visual function, and the second filter 16 corrects the spectral response curve of the photosensor 15. Obtaining a correction curve that matches the human visual function such that the illuminance value measured by the photosensor 15 by the received optical signal is consistent with the perception of the human eye, so that the photosensor 15 can replace the welder's eye. Judging the strength of light can better protect your eyes.

In addition, after the second filter 16 is modified, light that is invisible to the human eye but sensitive to the photosensor 15 can be shielded. For example, the photosensor 15 is sensitive to infrared rays, and is not corrected by the second filter 16. When a certain amount of infrared light is irradiated to the photosensor 15, the photosensor 15 may consider that a strong light is received, and an erroneous electric signal is output to the driving circuit 17, and the liquid crystal chip 13 is The light transmittance is lowered, and the automatic dimming filter is darkened, but in fact, the human eye does not see infrared light, and it is not considered that there is strong light at this time, so the automatic dimming filter may become dark. Affects the operation of the welder, causing adverse effects.

The second filter 16 is any one of a plating filter, an absorption filter, or a colored glass.

As shown in FIG. 2, the automatic dimming process of the automatic dimming welding filter provided by this embodiment is:

Before the arcing, when the user does not perform the soldering operation, the photosensor 15 does not detect the welding arc, the driving circuit 17 does not apply a voltage, and the liquid crystal panel 13 is in a bright state.

After the arcing, the soldering light is transmitted through the liquid crystal panel 13 by the photosensor 15, and the photosensor 15 is converted into an electric signal according to the received optical signal and fed back to the driving circuit 17, which is applied by the driving circuit 17. a certain voltage, the light transmittance of the liquid crystal panel 13 is lowered and darkened;

Through the above-mentioned continuous feedback closed-loop control system, until the automatic dimming filter is adjusted to correspond to the illuminance of the welding light, so that the automatic dimming filter is transmitted through the The light intensity of the light mirror is constant.

It should be noted that, since the amorphous silicon solar cell is mature in manufacturing, low in cost, and its spectral response curve is close to the human visual function, the correction effect is better. Therefore, the photosensor 15 provided by the present invention is preferably amorphous silicon. The solar cell, but not limited to the amorphous silicon solar cell, is capable of collecting an optical signal transmitted through the liquid crystal cell 13 and converting it into an electrical signal, and the photosensor that is fed back to the driving circuit 17 after amplification is in the present invention. Within the scope of protection.

Example 2

As shown in FIG. 4, the automatic dimming welding filter provided in this embodiment is different from the first embodiment only in that the automatic dimming welding filter further includes an outer side of the frame 11. An auxiliary photosensor 18 that collects an optical signal incident on the frame 11 and feeds back to the drive circuit 17, the drive circuit 17 controlling the signal according to a signal fed back by the auxiliary photosensor 18. The light transmittance of the liquid crystal panel 13 realizes a transition of the liquid crystal panel 13 from a bright state to a dark state.

The working state of the auxiliary photosensor 18 is a state in which the welding light is from scratch. Specifically, since the auxiliary photosensor 18 is disposed outside the frame 11, when the welding occurs, the auxiliary photosensor 18 first The welding light is received and fed back to the driving circuit 17, the light transmittance of the liquid crystal panel 13 is controlled, the liquid crystal panel 13 is previously darkened, and then the photosensor 15 is based on the light transmitted through the liquid crystal panel 13. The signal continues the feedback control process, reducing the effect of the hysteresis on the photosensor 15 due to linear amplifier circuit processing and the like.

The auxiliary photosensor 18 is a photoresistor or a photodiode.

It should be noted that the auxiliary photosensor 18 is working throughout the welding process to assist in determining whether a welding arc is currently occurring.

The present invention also provides an automatic dimming welding mask comprising an automatic dimming welding filter as described in Embodiment 1, the automatic dimming welding filter being fixed to the automatic by a frame On the dimming welding mask, the automatic dimming welding mask can automatically adjust the shading number according to the illumination of the welding light by using the automatic dimming welding filter, and the closed loop control system The welder's eyes are protected by constant illumination through the auto-dimming welding filter.

It is to be noted that the above-described embodiments are illustrative of the invention and are not intended to limit the invention, and that alternative embodiments can be devised by those skilled in the art without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as a limitation. The word "comprising" does not exclude the presence of the elements or steps that are not recited in the claims.

Claims

An automatic dimming welding filter, comprising: a frame (11), at least one liquid crystal panel (13), a photosensor (15), and a driving circuit (17) for driving the liquid crystal panel (13) The liquid crystal panel (13) and the photosensor (15) are both disposed on the frame (11), and the photosensor (15) is disposed on the side of the liquid crystal panel (13) near the human eye. The photosensor (15) collects an optical signal transmitted through the liquid crystal panel (13) and converts it into an electrical signal fed back to the driving circuit (17), and the driving circuit (17) is based on the photosensor (15) The feedback electrical signal controls the light transmittance of the liquid crystal cell (13) to form a closed loop control system such that the illuminance of the light transmitted through the auto-dimming welding filter is constant in the range of 0.05-1.0 lux.
The auto-dimming welding filter according to claim 1, wherein the photosensor (15) is an amorphous silicon solar cell.
The automatic dimming welding filter according to claim 2, wherein the photosensor (15) has a size ranging from 5 mm * 50 mm to 25 mm * 120 mm.
The automatic dimming welding filter according to claim 2, wherein the auto-dimmer welding filter further comprises a first filter (12) disposed on the frame (11) for The ultraviolet radiation and the infrared light are attenuated, and the first filter (12) is located on a side of the liquid crystal panel (13) away from the human eye.
The automatic dimming welding filter according to claim 1, wherein the auto-dimming welding filter further comprises a diffusing plate (14) provided on the frame (11) for reducing light. The effect of different incident angles on the optical signal, the diffusing plate (14) being located between the liquid crystal panel (13) and the photosensor (15).
The auto-dimming welding filter according to claim 5, wherein the auto-dimming welding filter further comprises a second filter (16) disposed on the frame (11) for Correcting the spectral response curve of the photosensor (15) to match the human visual function, the second filter (16) being located between the diffusing plate (14) and the photosensor (15) .
The automatic dimming welding filter according to claim 6, wherein said The second filter (16) is any one of a coated filter, an absorptive filter, or a colored glass.
The auto-dimming welding filter according to claim 1, wherein the auto-dimmer welding filter further comprises an auxiliary photosensor (18) disposed outside the frame (11), the auxiliary A photosensor (18) collects an optical signal incident on the frame (11) and feeds back to the drive circuit (17), the drive circuit (17) being controlled according to a signal fed back by the auxiliary photosensor (18) The light transmittance of the liquid crystal panel (13) realizes a transition from a bright state to a dark state of the auto-dimming solder filter.
The automatic dimming welding mask according to claim 8, characterized in that the auxiliary photosensor (18) is a photoresistor or a photodiode.
An automatic dimming welding mask, comprising the automatic dimming welding mask according to any one of claims 1 to 9.