LASER PROFILOMETRE Russian patent published in 2009 - IPC G01B11/24 

FIELD: physics; measurement.

SUBSTANCE: laser profilometre for controlling the profile of objects with an irregular shape of the type of blades of gas turbine engines using light section method has a fastening mechanism and a mechanism for longitudinal movement of blades, a source of slit-type lighting the blade, symmetrically arranged about the blade at its opposite ends and forming flat light beams in a plane, perpendicular the longitudinal axis of the blade. The device also has a TV camera, a computer for calculating parametres of the controlled section, two additional objective lenses, the optical axes of which are in the plane, formed by axes of the lasers and the longitudinal axis of the blade and lying symmetrically at angles α, to the longitudinal axis of the blade, which are chosen from the relationship α≥arctg (t/Δ). Focal distances of the additional objective lenses f_K, are chosen from the relationship The optical axis of the objective lens of the TV camera coincides with the axis of the first additional objective. Focal points of the additional objective lenses coincide with each other and with the point of intersection of the axes of the lasers and the longitudinal axis of the blade. The profilometre also has a beam splitter, the reflecting semitransparent plane of which is perpendicular to the plane, formed by axes of the additional objective lenses, and inclined at 45° to the axis of the objective lens of the TV camera. At the intersection of the optical axis of the second additional objective lens and the perpendicular, reproduced from the point of intersection of the reflecting plane of the beam splitter and the axis of the objective lens of the TV camera in the plane of the optical axes of the additional objective lenses, perpendicular this plane, there is a reflector. There are also two selective light filters, spectral transmission ranges of which do not coincide with each other and fitted in front of objective lenses on their optical axes perpendicular to them with provision for input-output from the optical arrangement, and a test object with a polychromatic lighting source, the radiation spectrum of which overlaps the spectral transmission ranges of both selective light filters and the spectral selectivity of the TV camera.

EFFECT: increased accuracy of measurement and metrological reliability of the profilometre.

2 dwg