Of grating detect principle of job of principle safety grating

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The working principle of common grating is a basis of stripe of the Mo Er on physics form a principle to have the job. Graph 4-9 is graph of its job principle. When the strain line on the strain line that should make indicate grating to go up and rear sight grating sets two grating rule into one angle, the strain line that can create two grating feet to go up necessarily is mutual across. Below the illuminate of illuminant, crossing overlaps as a result of black strain line inside near zonule, shading area is the consequently smallest, the effect that block light is the weakest, smooth accumulation action makes this area appears bright belt. Contrary, be apart from the region with more remote crossing, because of two grating feet the jackknife part of opaque black strain line becomes less and less, opaque area area greatens gradually, namely shading area greatens gradually, make strain of the effect that block light strong, only less light can pass through grating through this area, make this area appears shady area. These and grating strain line are almost perpendicular, the light that alternate with appears, shady area is Mo Er stripe. Mo Er stripe has the following quality: (When 1) should use grating of illuminate of parallel beam of light, through Mo Er the luminous intensity of stripe distributings approximate at cosine function. (If 2) indicates the breadth of Mo Er stripe with W, d states the bar of grating is apart from, θ expresses the included angle of strain line of two grating feet, criterion the geometrical relation between them is W=d ／ Sin (4—15) when horn very hour, take Sin≈ , type can be written into W=d ／ θ approximately on (4—16) if take D=0.

01mm, θ=0.

01rad, criterion by on type can get W=1mm. This explains, need not complex optical system and electric subsystem, use smooth interference appearance, can be apart from the bar of grating changeover becomes enlarge the width of the Mo Er stripe of 100 times. Action of this kind of enlarge is a of grating important characteristic. (3) because Mo Er stripe is by a certain number of collective interference forms grating strain line, so the bar between specific to grating strain line is apart from Mo Er stripe the error has average effect, can eliminate grating bar to be apart from the effect that inhomogenous place causes. (The shift of stripe of 4) Mo Er and the opposite shift between two grating feet are opposite should. Two grating feet is relatively mobile a bar is apart from D, mo Er stripe moves accordingly W of width of stripe of a Mo Er, its direction and the direction with two grating relatively mobile feet are perpendicular, and when be being changed relative to mobile direction when two grating feet, the direction with Mo Er mobile stripe also is changed subsequently. Basis of principle of job of graph 4-9 grating the character of afore-mentioned Mo Er stripe, if we are in,Mo Er opens 4 viewport mouth A on the direction with mobile stripe, b, c, d, and make two two-phase are apart from these 4 windows 1 ／ width of 4 Mo Er stripe, namely W ／ 4. By afore-mentioned discussion knowable, when two grating feet is relatively mobile, mo Er stripe moves subsequently, observe window A from 4, b, c, d can get 4 are in phasic go up ordinal lead or lag (depend on the direction with two grating relatively mobile feet) 4 cycle of 1 ／ (namely of π ／ 2) change at the luminous intensity of cosine function approximately process, with express, see graph 4-9(c) . If use photosensitive component to detect, photosensitive component changes the luminous intensity change that passes through viewport mouth into corresponding voltage signal, set for. According to signal of these 4 voltage, can detect the opposite shift that gives grating rule. 1. Of  displacement size because the shift of Mo Er stripe and the opposite shift between two grating feet are to answer relatively,detect, reason is passed detect the metabolic circumstance of signal of these 4 voltage, can detect accordingly an opposite shift between two grating feet. Every change a cycle, namely Mo Er stripe every change a cycle, show two grating feet moved relatively the distance that a bar is apart from; If the opposite shift between two grating feet is less than a bar to be apart from, because be cosine function, the value of reason foundation also can be calculated the space that gives its to move relatively. Of direction of 2  displacement detect in graph 4-9(a) , if rear sight grating is secured,do not move, square of demonstrative grating edge to shift, at this moment, mo Er stripe moves accordingly along the direction that be down, pass through viewport mouth A and B, the process of luminous intensity change that photosensitive component detects and the corresponding voltage signal that reach output and place of the 4-10(a) that be like a graph are shown, below this kind of circumstance, of lag phasic for ／ 2; Conversely, if rear sight grating is secured,do not move, demonstrative grating moves along negative direction, at this moment, mo Er stripe is corresponding ground edge up direction is mobile, pass through viewport mouth A and B, the process of luminous intensity change that photosensitive component detects and the corresponding voltage signal that reach output and place of the 4-10(b) that be like a graph are shown, below this kind of circumstance, of lead phasic for ／ 2. Accordingly, basis and two signal mutual the lead between and lag concern, can decide the relatively mobile way between two grating feet truly. The displacement of graph 4-10 grating detects block diagram of circuitry of information processing of grating of 4-11 of principle plan plan of 3  speed detect the floating rate that the relatively floating rate of two grating feet is deciding Mo Er stripe, deciding to pass through the frequency of the luminous intensity of viewport mouth namely, accordingly, can conclude through detected metabolic frequency the relatively floating rate that gives two grating rule. The working principle of safe grating: Give out infra-red beam of light by emitter, receiver undertakes correspondence is received, form protective smooth act. If the object is passed from inside grating, can obscure corresponding infra-red light, photoelectricity sensor can detect, it is smooth signal change telegraphic date, transmit PLC or call the police circuit, implementation equipment stops or issue safe warning thereby, the composition of the grating of person safety security of the safe production that ensures equipment and operator: Give off light implement: By composition of a certain number of glow parts of an apparatus, shoot infra-red light; Get light implement: By composition of a certain number of parts of an apparatus getting light, accept infra-red light, with glow implement glow parts of an apparatus is one to one correspondence, form protective smooth act, generation connects signal of smooth, shading, transmit signal controller to undertake controlling to peripheral equipment through signal cable at the same time; Signal cable: Use transmission controller and irradiation implement, get light implement the functional characteristic of the signal safety grating between: Installation way is agile, simple, have waterproof and dustproof function, photoelectricity loop self check, use line synchronism technology, interference rejection capability is strong, SMD sticks a design, entrance high end yuan parts of an apparatus, noise is in season a short, reliability is high. 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