35 results about "Freeform surface machining" patented technology

The invention discloses a method for curve surface grinding with a cylindrical grinding wheel at a virtual ball cutter radius. The method includes the steps that 1, the attitude angle of the cylindrical grinding wheel is designed, and the inclination angle of the axis of the cylindrical grinding wheel on a curve surface tangency point normal vector is designed through a virtual ball cutter model; 2, a cutter path is planned and determined according to the curved surface tangency point normal vector and the virtual ball cutter model, and the set inclination angle in the step 1 is guaranteed through a rotating shaft of a machine tool; 3, by the adoption of an axial feeding mode, a workpiece is subjected to grinding machining according to the cutter path. The cylindrical or quasi-cylindrical grinding wheel can be used for four-axis machining of a free curved surface, and the method has the advantages that planning of the cutter path is simple and flexible, the precision of a machining shape is high, and surface roughness is low, and is suitable for machining free curve surfaces of optical glass and other hard brittle materials.

The invention relates to an arc length parameter curve processing track generation method of a free curved surface. The method comprises following steps of smooth and continuous characteristic curve processing track extraction, given precision parameter curve processing track generation and processing track arc length parameterization. In the step (1), processing tracks generated by computer aidedmanufacturing software (CAM) are classified according to arc length characteristics; and discrete free curve processing tracks with smooth and continuous characteristics are extracted; in the step (2), fitting is performed on the extracted discrete free curve processing tracks under the given precision, so parameter curve processing tracks meeting a geometric representation precision requirementare obtained; and in the step (3), by use of the method of continuous iteration arc length re-parameterization, arc length re-parameterization is performed on the parameter curves obtained in the step(2), and finally, the arc length parameter curve free curved face processing track is obtained. According to the invention, the difficulty level in real-time interpolation and speed planning in freecurved face processing is reduced; and smoothness and processing precision in the processing process are improved.

The invention discloses a tracing method for determining a local interference region boundary of free-form surface machining. Through analysis of principal curvatures of a free-form surface and an isometric offset surface, the local interference region boundary condition of the free-form surface machining is obtained. A tracing initial point of the local interference region boundary is obtained through combination of a surface discrete method and a dichotomy method. A rough point of the local interference region boundary is obtained through tracking along an osculating circle of the interference region boundary from the initial point. A precision point of the local interference region boundary is calculated through iteration by using a gradient method. Two tracing judgmental end conditions are obtained according to the condition that whether the local interference region boundary is enclosed on the surface. The tracing method for determining local interference region boundary of the free-form surface machining has the advantages that the tracing method is suitable for fast tracing and determining the interference region boundary of the complex free-form surface machining, a tool path track is regionally planned, a total length of the tool path track is reduced, and the surface machining efficiency is improved.

The invention relates to design method of a grating with a glaring concave surface. For a concave substrate with the preset radius R, carving grooves with preset angles and intervals are carved on the substrate so as to obtain the grating with the glaring concave surface. Incident light is spherical wave sent out by a point light source, the point light source is located on a Rowland circle, angles of curving groove surfaces are designed so as to enable the incident light to be perpendicular to the carving groove surfaces, the interval of the carving grooves is designed so as to enable optical path difference of adjacent carving grooves to be integral multiple of preset wavelength, carving grooves with corresponding angles and interval are carved one by one on the concave substrate by using a free curved-surface processing instrument, and the required grating with the glaring concave surface is obtained. The designed concave grating has remarkable glaring enhancement effect on the preset wavelength lambda, the design method is convenient to implement, only relates to calculation of elementary mathematics, dose not need professional optical design software, and the designed grating with the glaring concave surface can be widely applied to the technical field of a spectrum analysis instrument, optical detection, optical measurement and the like.

The invention discloses a free-form surface processing device which comprises a workpiece shaft unit, a drive unit for driving the workpiece shaft unit to rotate, a workpiece shaft feeding unit for driving the workpiece shaft unit to rapidly axially displace, a cutter unit and a cutter feeding unit for driving the cutter unit to slowly axially and radially displace. The free-form surface processing device also comprises a coupler arranged between the workpiece shaft unit and the drive unit, wherein the drive unit is fixedly arranged and the workpiece shaft unit can axially displace relative to the drive unit. Compared with the prior art, the drive unit used for driving the workpiece shaft unit to rotate is relatively fixedly arranged, and the coupler is arranged between the workpiece shaft unit and the drive unit, therefore, the workpiece shaft feeding unit can drive the workpiece shaft unit to axially displace relative to the drive unit, the mass of the rapid displacing part is reduced furthest, thus the rapid feeding acceleration can be reliably improved when in same power, and the purposes of improving the workpiece rotating speed and further enhancing the processing efficiencycan be realized.

The invention relates to a single-motor double-degree-of-freedom speed change wheel type airbag polishing device, and belongs to the field of precise free curved surface machining. A revolving drivingunit is fixed at the upper part of a shell unit; a rotation driving unit is fixed under the revolving driving unit; a tool driving unit is fixed under the rotation driving unit; an airbag polishing tool unit is fixed on the tool driving unit; and air pressure control units are integrated in the revolving driving unit and the tool driving unit. The device has the following advantages: the revolving and rotation double-degree-of-freedom movement is performed on the surfaces of workpieces to form Gaussion like removing functions; and single motor drives double-degree-of-freedom airbags for polishing movement, so that the structure redundancy is reduced, the driving chain stacking problem is improved, the maintenance of stable revolving and rotation speed ratio is facilitated, and the stability of device removing functions is improved.

The invention belongs to the technical field of ultra-precise work and complex parts manufacturing, which relates to a path generating method of a curved face processing. The method is utilized on a diamond ultra-precise machine tool with three shafts, which comprises first, establishing a coordinate system of a free curved face model of a processing surface of a workpiece, and establishing conversion relationship between the model coordinate system and a machine tool coordinate system, second, conversing the model coordinate of a processing point on the processed free curved face to a coordinate under the coordinate system of the machine tool, third, solving and processing a normal vector of cutting face of a cutter when the point is processed, fourth, projecting the normal vector of the point of the curved face on the cutting face, and compensating a circular arc radius of the cutter on the projection vector direction, and getting a coordinate of the arc center of the cutting edge under the cutting edge coordinate system, traversing the processing point on the free curved face, at last generating a processing path. The limitation of processing the free curved face on the machine tool with three shafts can be broken by adopting the path generating method which is provided by the invention, the invention can achieve ultra-sophisticated processing of the free curved face.

The invention discloses a method for curve surface grinding with a cylindrical grinding wheel at a virtual ball cutter radius. The method includes the steps that 1, the attitude angle of the cylindrical grinding wheel is designed, and the inclination angle of the axis of the cylindrical grinding wheel on a curve surface tangency point normal vector is designed through a virtual ball cutter model; 2, a cutter path is planned and determined according to the curved surface tangency point normal vector and the virtual ball cutter model, and the set inclination angle in the step 1 is guaranteed through a rotating shaft of a machine tool; 3, by the adoption of an axial feeding mode, a workpiece is subjected to grinding machining according to the cutter path. The cylindrical or quasi-cylindrical grinding wheel can be used for four-axis machining of a free curved surface, and the method has the advantages that planning of the cutter path is simple and flexible, the precision of a machining shape is high, and surface roughness is low, and is suitable for machining free curve surfaces of optical glass and other hard brittle materials.

The invention discloses a reflection type homogenizing mirror for generating flat-top-like rectangular light spots and a homogenizing system, and belongs to the field of laser processing. The reflection type homogenizing mirror for generating flat-top-like rectangular light spots comprises a mirror body and a reflection mirror surface, the reflection mirror surface comprises a left rotating curved surface set and a right rotating curved surface set, the distance fw between the rotating curved surface sets and a working face, the vertical distances hl and hr between the rotating curved surface sets and respective rotating shafts, and the distances dl and dr between the left rotating shaft and the right rotating shaft and the central axis of the two rotating curved surface sets meet the relations shown in the following formulas, uniform-like light spots can be obtained in the uniform-like direction, D1 is the left half width of incident light on the reflecting mirror surface, and Dr is the right half width of the incident light on the reflecting mirror surface. The light spot edge in the quasi-uniform direction drops steeply, so that the virtual light influence caused by Gaussian distribution can be greatly reduced, the utilization rate of Gaussian beam edge energy is effectively improved, and the application range is wider. According to the device, a high-precision rotating lathe can be adopted for machining, an expensive high-precision free-form surface machining machine tool is not needed, and the machining cost can be reduced.

The invention discloses a tracing method for determining a local interference region boundary of free-form surface machining. Through analysis of principal curvatures of a free-form surface and an isometric offset surface, the local interference region boundary condition of the free-form surface machining is obtained. A tracing initial point of the local interference region boundary is obtained through combination of a surface discrete method and a dichotomy method. A rough point of the local interference region boundary is obtained through tracking along an osculating circle of the interference region boundary from the initial point. A precision point of the local interference region boundary is calculated through iteration by using a gradient method. Two tracing judgmental end conditions are obtained according to the condition that whether the local interference region boundary is enclosed on the surface. The tracing method for determining local interference region boundary of the free-form surface machining has the advantages that the tracing method is suitable for fast tracing and determining the interference region boundary of the complex free-form surface machining, a tool path track is regionally planned, a total length of the tool path track is reduced, and the surface machining efficiency is improved.

The invention relates to a method for controlling a machining track of a numerically-controlled machine tool. The method comprises the following steps of: determining the number N of positions to be smoothly machined; initialing N displacement storage units and storing the planned displacement of current movement in a machining plan into a current displacement storage unit; taking an average value of the N displacement storage units as the actual displacement of the current movement; and circulating the process to finish the machining. By utilizing the method disclosed by the invention, the displacement in single time of movement in the machining plan is realized by being dispersed into N times of movements so that the displacement variables among multiple times of close movements are reduced, the fitting degree of a machined free-form surface is better, and the degree of finish of the machined surface is higher; therefore, with the method disclosed by the invention, under the condition that a machining file does not need to be lengthened, the degree of finish of the machined free-form surface is increased, the increase of data processing amount of the numerically-controlled machine tool is avoided, and the cost of the numerically-controlled machine tool is reduced under the condition that application requirements are same.

The invention relates to an arc length parameter curve processing track generation method of a free curved surface. The method comprises following steps of smooth and continuous characteristic curve processing track extraction, given precision parameter curve processing track generation and processing track arc length parameterization. In the step (1), processing tracks generated by computer aidedmanufacturing software (CAM) are classified according to arc length characteristics; and discrete free curve processing tracks with smooth and continuous characteristics are extracted; in the step (2), fitting is performed on the extracted discrete free curve processing tracks under the given precision, so parameter curve processing tracks meeting a geometric representation precision requirementare obtained; and in the step (3), by use of the method of continuous iteration arc length re-parameterization, arc length re-parameterization is performed on the parameter curves obtained in the step(2), and finally, the arc length parameter curve free curved face processing track is obtained. According to the invention, the difficulty level in real-time interpolation and speed planning in freecurved face processing is reduced; and smoothness and processing precision in the processing process are improved.

The invention relates to a single-motor double-degree-of-freedom variable-speed wheel airbag polishing device, which belongs to the field of precision free-form surface processing. The revolution drive unit is fixed on the upper part of the shell unit, the autorotation drive unit is fixed under the revolution drive unit, the tool drive unit is fixed under the autorotation drive unit, the airbag polishing tool unit is fixed on the tool drive unit, and the air pressure control unit is integrated between the revolution drive unit and the in the tool drive unit. The advantage is that the airbag performs two-degree-of-freedom motion on the surface of the workpiece, forming a Gaussian-like removal function. The single-motor drives the two-degree-of-freedom airbag polishing movement, which not only reduces structural redundancy and improves the stacking problem of the drive chain, but also helps maintain a stable The public rotation speed ratio increases the stability of the removal function of the device.

The invention discloses a machining error rapid detection and compensation method based on an NURBS curved surface. The method comprises the steps that a designed NURBS curved surface is analyzed, and a series of characteristic points are selected as a sequence P to be measured; according to a machine tool processing curved surface applied to the designed NURBS curved surface, points to be measured in the sequence P to be measured are measured to acquire an actually measured sequence Q'; the deviation between the actually measured sequence Q' and the sequence P to be measured is computed; if the deviation is less than or equal to the machining accuracy, adjusting is not needed; if the deviation is greater than the machining precision, the sequence P to be measured is adjusted according to the deviation to acquire a compensation sequence W; 4) a control point C is adjusted according to the compensation sequence W to acquire a compensation curved surface; and machining is carried out according to the compensation curved surface to acquire a machining curved surface, wherein the error between the machining curved surface and the designed NURBS curved surface is small. According to the method provided by the invention, the efficiency of the detection of an on machine measurement method on the machining accuracy of a free curved surface is improved, and compensation machining can be carried out on the free curved surface.

The invention discloses a generating method of a three-dimensional elliptical vibrating cutting optical freeform surface machining path. The generating method is used on a triaxial diamond ultra-precision machine tool and an elliptical vibration generating device. A machine tool spindle can perform rotary motion, a working table can perform X-direction and Z-direction motions, and simultaneously a diamond cutter performs three-dimensional elliptical motion through the elliptical vibration generating device. The generating method of a cutter path track comprises building a workpiece Cartesian coordinate system, and obtaining an expression of the predesigned free optical curved surface S under the workpiece Cartesian coordinate system and a cylindrical coordinate system; determining coordinate values of xi, j(L) and yi, j(L) of a cutter location point PL (i, j); solving coordinate values of xi, j(L2) and yi and j(L2) of a new cutter location point PL2 (i, j) adding to elliptical y-directional displacement and x-directional displacement; solving the z coordinate value zi, j(L2) of a cutter location point PL2 (i, j) according to the coordinate values of xi, j(L2) and yi, j(L2) of the cutter location point PL2 (i, j); solving z coordinate value zi, j(L3) of a new cutter location point PL3 (i, j) added to elliptical z-directional displacement; and performing processing motion according to the steps, traversing processing points of the freeform surface, and finally generating the processing path.