6 results about "Ideal surface" patented technology

The application relates to the technical field of non-ideal surface generation of machined parts, and particularly discloses a construction method of an assembly joint surface considering wavelet and fractals, which comprises the following steps: S1, according to an ideal numerical model of the assembly joint surface; S2, comparing calculation methods of different fractal parameters; S3, aiming at the assembly joint surface of parts under different machining modes; S4, regarding the assembly joint surface as a structure formed by superposition of different scale contours; S5, introducing a power spectrum analysis method to analyze the surface contour curve characteristics of the assembly joint surface; S6, according to the isotropic or anisotropic properties of the assembly joint surface under different machining modes, introducing the statistical distribution characteristic parameters determined in step S3 into the representation of the assembly joint surface; and S7, associating the contour curve characteristic parameters extracted in step S4 with the fractal parameters determined in step S2. Through multi-scale decomposition of the assembly joint surface by wavelet transform, the specific information of the roughness contour, the waviness contour and the shape error contour can be effectively extracted.

The application belongs to the field of finite element modeling, and particularly relates to a finite element modeling method considering multi-scale characteristics of an assembly interface, structural data of a rough surface is collected, a rough surface height matrix is obtained after convolution coefficient calculation; an ideal surface corresponding to the rough surface is determined, and geometric information of the ideal surface is obtained; the rough surface height matrix is modeled and superimposed on the ideal surface to obtain superimposed rough surface information; finite element modeling is performed on different superimposed rough surface information of the multi-scale surface to obtain a finite element model containing multi-scale characteristics of the assembly interface. The technical problem that existing finite element modeling software and tools cannot directly realize multi-scale modeling of the assembly interface and can only establish a model based on ideal product size, resulting in an ideal smooth contact state of the assembly interface, is solved, and the multi-scale characteristics of the assembly interface are successfully included in the product finite element model, so that the model can contain multi-scale geometric information of the actual surface of the part.

This invention discloses a method for modeling non-ideal surfaces of complex curved parts based on quasi-conformal mapping, belonging to the technical field of complex curved part modeling. The method includes: constructing an initial manufacturing deviation field by calculating the normal distance between each node of the theoretical model surface and the corresponding measured point cloud data; unfolding the developable surface region of the part surface to a two-dimensional plane, and mapping the non-developable surface region to a two-dimensional rectangular domain based on quasi-conformal mapping; obtaining the mapped manufacturing deviation field; performing discrete cosine transform mode decomposition to identify and retain key deviation modes that meet preset energy compaction requirements, and reconstructing them through inverse discrete cosine transform to obtain the reconstructed mapped deviation field; and mapping the reconstructed mapped deviation field back to the original three-dimensional surface of the part through quasi-conformal inverse mapping to construct the non-ideal surface model of the part. This invention achieves high-fidelity modeling of the surface of composite parts containing complex curved surfaces, improving the reliability of assembly accuracy prediction.

The invention relates to the technical field of optical element precision manufacturing, in particular to an optical element three-dimensional modeling method based on normal projection inverse transformation. Comprising the steps of establishing an ideal curved surface parameterization vector expression according to optical design parameters, and determining a curved surface body coordinate system and a vector height function; solving the gradient of the rise function to obtain gradient information of each point of the curved surface and calculating a unit normal vector; projecting the three-dimensional curved surface points to a preset reference plane along the normal direction of the curved surface, establishing a forward geometric mapping relation from the three-dimensional coordinates of the curved surface body coordinate system to the measurement coordinates of the interferometer, and obtaining an explicit expression of the measurement coordinates; two-dimensional normal error distribution data of the optical element are collected, errors are overlaid in the normal direction to construct an actual curved surface expression containing manufacturing errors, and the corresponding relation between three-dimensional normal errors and measurement data is established; and on the basis of forward mapping relation numerical value inverse transformation, the measurement coordinates are inversely calculated into curved surface body coordinates, and the curved surface body coordinates are substituted into an actual curved surface expression to obtain a complete three-dimensional curved surface model containing manufacturing errors.

Provided is a high-precision grinding apparatus for a sealing pair of a triple eccentric butterfly valve, belonging to the technical field of grinding apparatuses. The high-precision grinding apparatus comprises an apparatus body (51), an apparatus base (10), a rotating base (101), a cross beam (52), a grinding-head slide carriage (54), an operating platform (56), a hydrostatic‑hydrodynamic grinding-head motorized spindle (103), an X-axis movement assembly, a Z-axis movement assembly (55), and a swing-angle driving mechanism, wherein the X-axis movement assembly is configured to drive a transverse slide carriage (53) to move, and the swing-angle driving mechanism is configured to drive the rotating base (101) to rotate relative to the apparatus base (10). By means of providing the swing-angle driving mechanism, the X-axis movement assembly and the Z-axis movement assembly (55), a grinding wheel (104) always moves on a sealing surface, which is subjected to grinding, of a workpiece during grinding, that is, following grinding is performed. The ideal surface finish of the ground surface of the sealing pair reaches Ra0.2 or less, and the roundness of inner and outer ground circles reaches 0.003 mm. The machining time is fully utilized, improving the grinding efficiency; the grinding force is uniform, improving the grinding precision; and the compatibility and sealing performance of the sealing pair of the triple eccentric butterfly valve are ensured, thereby achieving 100％ sealing pair interchangeability.

This invention relates to the field of mold polishing technology, specifically to an automatic polishing method and system for neodymium iron boron molding dies. The method includes: clamping the die to be polished and using a laser profilometer to measure reference points and establish a workpiece coordinate system; registering the surface model and surface roughness parameters in the workpiece coordinate system to obtain the surface data to be processed; resampling the areas to be polished to determine the polishing depth and planning graded polishing trajectories; and calling the corresponding polishing modules to execute the graded polishing trajectories. Addressing the problem of uneven polishing and surface misalignment that easily occur in existing automated polishing systems when handling complex surface polishing tasks, this invention determines the available polishing depth at different points based on the error between the surface data to be processed and the ideal surface data, and plans graded polishing trajectories for polishing modules with different roughnesses. This eliminates rough surfaces and burrs, while ensuring that the final polishing result matches the ideal surface data.