71 results about "Tolerance design" patented technology

The invention discloses a tolerance optimization allocation method based on a tolerance grade and a genetic algorithm, comprising the following steps: (1) creating a tolerance optimization mathematical model; (2) creating a standard tolerance database; (3) encoding based on the tolerance grade; (4) determining an adaptability function of the genetic algorithm; (5) setting a genetic operator; (6) performing genetic evolution; and (7) decoding to obtain a corresponding tolerance grade and inquiring a corresponding tolerance value. The method disclosed by the invention realizes the tolerance optimization allocation in the product design by using a computer, thereby replacing the manual distribution, improving the efficiency and saving the time; meanwhile, the method performs the optimization allocation through the genetic algorithm, serves the minimum processing cost as an optimization target and reduces the processing cost of products. Therefore, the method has good practical value and extensive application prospect in the technical field of computer aided tolerance design.

The invention relates to an actual-condition tolerance modeling method based on Jacobian spinors, belonging to the technical field of mechanical tolerance digitization. By calculating the deformation of a working part during loading, changing to the correction quantity of Jacobian spinors and compensating and correcting a Jacobian spinor tolerance model in an ideal condition, the invention establishes an assembly tolerance mathematical model based on Jacobian spinors and actual conditions. The actual-condition tolerance modeling method is technically characterized by comprising the steps of: firstly establishing an assembly tolerance model in the ideal condition; then considering the influences of environmental factors in the actual conditions, and calculating the changes of the size, the shape and the position of a component caused by the influences; mathematically expressing the changes in a spinor matrix mode as compensation, and combining the compensation with the tolerance model in the ideal conditions; and finally obtaining the assembly tolerance model in the actual conditions accordingly. The invention has the advantages that calculation results can be used for judging the assembling properties in the actual conditions and verifying and checking the tolerance design results, thereby predicting and judging the changes of product performances under different assembling design tolerances.

A method and system is provided for achieving good dynamic performance and negligible wear to spindle motor components. In an aspect, a disc drive storage system is provided having a hydro bearing surface coating for meeting bearing gap tolerance design specifications. In an aspect, the surface coating is a non-reactive coating of diamond like carbon (DLC), applied with physical vapor deposition (PVD). In an aspect, the surface coating nullifies any taper of an opposing surface coating. In an aspect, the hydro bearing, with an applied coating, defines a uniform gap between 0.5 microns and 6 microns.

The invention relates to a design method of twin-screw pulping mechanism statistical tolerance. The requirements for side clearance and diametral clearance of the twin-screw pulping machine are transformed to the requirements for dimension tolerance and form and position tolerances of such parts of the twin-screw pulping machine as a screw element, a mandrel and the like, thus laying a solid foundation for the precision design, tolerance design, assurance of assembly quality and reduction of manufacturing cost. Especially, the design method of computer assistant statistical tolerance based on mixed convolution algorithm, on the premise of guaranteeing the assembly quality of a complex dimension chain, provides more favorable tools and methods for the further reduction of the processing cost of the parts. The design method has important meaning for the design and manufacturing of the twin-screw pulping machine and assurance of the quality of the twin-screw pulping machine.

The invention relates to a design method of computer assistant tolerance statistics based on mixed convolution algorithm. A dimension chain is provided with n composition rings, the function relation between the dimension Z of a closed ring and the dimension Xi of the composition ring is set as a design function which is analyzed into a linear part and a nonlinear part, the nonlinear part is linearized and a high-level remainder is omitted to transform the design function into a linear function, i.e., a mixed convolution method comprising a resolution convolution and a numerical convolution can be used for determining the distribution of the dimension Z of the closed ring, and the calculation results can be corrected by the adoption of a closed ring correction method or a composition ring correction method. The design method promotes the existing tolerance statistics method to the calculation of the dimension chain of the composition ring and the closed ring with different distributions, is applicable to the mixed convolution algorithm that is effective for various linear and nonlinear problems, and has relatively rapid calculation speed and relatively high calculation precision.

The invention discloses an inspection device for a three-way catalyst assembly of an automobile. The inspection device comprises a base, a benchmark positioning mechanism, a guide supporting mechanism, a support location detecting mechanism, an oxygen sensor base and hanging hook location detecting mechanism and a discharge flange detecting mechanism, wherein the benchmark positioning mechanism, the guide supporting mechanism, the support location detecting mechanism, the oxygen sensor base and hanging hook location detecting mechanism and the discharge flange detecting mechanism are respectively fixed on the base according to the mutual corresponding relations with the three-way catalyst assembly. The inspection device is easy and convenient to operate, high in detecting accuracy and capable of detecting whether a key assembly location satisfies the assembly requirements and tolerance design requirements, improving detecting tact and enhancing production efficiency.

The invention discloses a tolerance modeling method based on a peripheral Bezier parameter space. An ideal workpiece is embedded into a peripheral Bezier parameter space, the workpiece is expressed through control points of the peripheral parameter space, the positions of the control points are changed, the peripheral parameter space is changed, and therefore the size, the shape and the position of the embedded workpiece are indirectly changed. By establishing a mathematical model between the offset of the peripheral space control point and the workpiece tolerance range, the offset of the peripheral control point can be solved within a given tolerance range, and finally a tolerance representation and statistical tolerance model under the worst condition is obtained. According to the method, the assembly property under the actual working condition can be judged according to the calculation result, the tolerance design result is verified and checked, and then product performance changesunder different assembly design tolerances can be predicted and judged; The modeling mode is not only suitable for dimensional tolerance modeling, but also suitable for form and location tolerance modeling; And meanwhile, the method is suitable for tolerance analysis and integration under the worst condition, and is also suitable for tolerance analysis and design under statistical significance.

The invention relates to an assembly tolerance optimization method based on quality loss and cost minimization. The method mainly comprises the following steps: establishing a mathematical model of quality loss and processing cost; adding actual processing capability constraints; performing parameter initialization on a multi-objective teaching and learning algorithm; performing iteration in a teaching phase on an initial solution of the algorithm; adopting a hill-climbing search strategy to further develop the solution; performing Pareto ranking on a population; further studying the solution, and further increasing the accuracy of the solution; and completing the iterative process and finding the optimal solution. The assembly tolerance optimization method based on the quality loss and cost minimization provided by the invention is based on the computer technology, and combines the swarm intelligent optimization algorithm in the field of artificial intelligence, which further improves the calculation efficiency and calculation accuracy of assembly tolerance design, and aims to satisfy the design accuracy under precision manufacturing, improve the production efficiency, and improve the parts quality, so as to further reduce the production cost.

The invention discloses a machine tool assembling joint surface design method capable of taking deformation error compensation as a target. The method comprises the following steps: in CAD (Computer Aided Design) software, according to statics analysis requirements and the structural characteristics of a machine tool, carrying out structure simplification; then, carrying out parameterized assembling on a machine tool entity model; importing the entity model subjected to the simplification and the parameterized assembling into finite element analysis software Ansys Workbench; creating a container capable of carrying out automatic analysis and extraction deformation by utilizing the software, carrying out orthogonalization of a processing spatial position and mesh generation, and meanwhile, finishing statics analysis and result storage; then, through data learning, obtaining the practical deformation amount of a machine tool assembling nominal joint surface under a situation that whole processing space deformation is considered; flipping the obtained practical deformation amount, adding the flipped amount and the nominal joint surface to serve as an actively designed machine tool assembling joint surface; and on the basis of a Monte Carlo method and a least square method, finishing profile tolerance design of the assembling joint surface with the combination of a data regression technology.

The invention discloses a tolerance management system and a tolerance management method. The method is used for enterprises to manage product appearance (gap and surface difference), noise, vibration,assembly interference, poor product interchangeability, long manufacturing period and low product qualification rate caused by tolerance in product design and manufacturing stages. According to the solution, tolerance is taken as an entry point, and analysis and feedback are established for detection data of a product in a design stage and a manufacturing stage of the product, so that closed-loopcyclic feedback of a size data flow from design to manufacturing to design is realized; whole-process tracking and management of product part dimensional tolerance from design to process, to manufacturing and then to detection are realized; the capacity of dimensional tolerance design and management of enterprises is continuously improved, and the iterative efficiency of product structure designoptimization is improved. Therefore, the consistency of products is improved, the assembly quality and the assembly efficiency are improved, the design robustness and the product quality stability areimproved, and finally the purposes of improving the quality, reducing the cost, increasing the batch and shortening the period are achieved.

The present invention discloses a T/R module automatic test system structure. The structure comprises a pressing plate, a heat conduction pad, a cold plate, an upper cover plate, a frame, an A panel,a side cover plate, a B panel, a bottom plate and a device installation plate. A standard piece is employed to connect with the cold plate, the heat conduction pad, a T/R module, the pressing plate and the upper cover plate, an upper end of a KK joint is inserted into the T/R module through circular holes of the upper cover plate and the cold plate, and the test system is inserted into the lowerend of the KK joint to form an access. Through the dimensional tolerance design of the cold plate, the KK joint and the T/R module, the high-precision mutual insertion is achieved to ensure the electrical performances. The test system is installed on the installation plate. The A panel, the B panel, the side cover plate and the bottom plate are connected with an assembling structure on the frame to achieve the automatic test function of the T/R module. The system is compact in structure, convenient to implement and low in cost, simulates the T/R module working scene in high precision, improvesthe test efficiency of the T/R module and ensures the test reliability.

The invention belongs to the design of a helicopter automatic inclinator, and in particular relates to a guide cylinder-free automatic inclinator which is an important part of a light unmanned helicopter rotor system. The guide cylinder-free automatic inclinator of the unmanned helicopter is characterized by comprising moving rings (1), a fixed ring (2), variable pitch pull rod components (3), torque arm components (4), a snap ring (5), an anti-torque arm component (6) and spherical hinge components (8). According to a set of the guide cylinder-free automatic inclinator provided by the invention, the spherical hinge components and self-lubricating bushings of special structures are selected to reduce the design of high-cost parts of guide cylinders, wear-resistant bushings and the like, and the guide cylinder-free automatic inclinator has the advantages of simple structure, light weight, convenience in use and maintenance and the like. Clever part tolerance design is adopted, so that the use of wear-resistant washers at part assembling interfaces is canceled to control transverse gaps of the assembling interfaces between the torque arm parts and the anti-torque arm parts to effectively improve the reliability and prolong the fatigue life of the whole automatic inclinator and lower the design and manufacture costs.

The invention discloses a tolerance distribution method and device for a flexible thin-wall structure based on a deformed base, and belongs to the technical field of machine manufacturing. According to the tolerance distribution method for the flexible thin-wall structure based on the deformed base provided by the invention, a modal shape forming a basic unit of an assembly is selected as a basic deformed base, a bias field is represented by using the deformed base and a corresponding bias factor, the relevance of the bias factor of the assembly and the bias factor of the basic unit is used as one item in constraint conditions, an objective function for a tolerance allocation model is solved, and an optimal bias factor of the assembly is solved, so that prediction and control for the bias factor of each basic unit of the assembly are realized, and the tolerance design problem of the flexible large thin-film structure can be solved. Tolerance values are allocated for each basic unit, so that the measuring efficiency and the assembling quality of the product are effectively improved.

The invention discloses a method for welding an automotive anti-rolling steel tube and an A column reinforcement plate. The A column reinforcement plate comprises an upper reinforcement plate and a lower reinforcement plate. The A column reinforcement plate and the steel tube are positioned by molding surfaces. A certain welding manufacture gap is formed between the steel tube and two sides of the upper reinforcement plate. One side of the lower reinforcement plate contacts the steel tube, and the steel tube is welded on the A column reinforcement plate under the condition that the other side of the lower reinforcement plate is not contacted with the steel tube. The welding method has the following advantages: a tolerance design is adopted for the welding between the A column reinforcement plate and the steel tube, so that a design gap is formed between the A column reinforcement plate and the steel tube, and a manufacturing error and a clamping error of the steel tube (with a curvature) are guaranteed; the A column steel tube and the A column reinforcement plate are positioned by the molding surfaces, the welding is more firm and the requirement on complete automobile performance is met due to a plug welding mode; the welding method can guarantee welding precision and assembly, realizes the welding technology, also can improve the welding strength of the steel tube and has more firm welding.

The invention discloses a tolerance optimization method for all-welded assemblies, relates to welding deformation accumulated error prediction and tolerance optimization of multiple assemblies, and solves the problem of tolerance design optimization requirements of all-welded assemblies. The method comprises the steps that original design information of all-welded assemblies is collected, and various kinds of tolerance information are summarized; a three-dimensional tolerance analysis model is established, simulation analysis is conducted through virtual assembly, and the deviation of the total deflection amount of the all-welded assembly is predicted; and a weighted calculation value is established based on the contribution degree factor and the sensitivity factor of each deviation and the control difficulty factor of welding deformation, and iteration is continuously performed according to a simulation analysis result until a tolerance optimization scheme meeting an optimization target is obtained and output. According to the method, the welding deformation accumulative error can be effectively predicted, tolerance optimization is achieved, and the efficiency of tolerance secondary design is improved.

The invention relates to a tolerance design method of multi-axis machine tool parts based on comprehensive geometric precision, in particular to a tolerance design method of multi-axis machine tool parts to solve the problems that an existing comprehensive geometric precision design of a multi-axis machine tool is not implemented into a specific tolerance design of each part forming a kinematic pair, and the comprehensive geometric precision design has a long period and a poor feasibility, and does little help to subsequent comprehensive error compensation direction of the machine tool. The design method mainly comprises the following steps: step 1, analyzing geometric error items of the multi-axis machine tool; step 2, giving geometric tolerance items required to be controlled for each part forming the kinematic pair of the machine tool; step 3, establishing a geometric tolerance analysis model of the multi-axis machine tool; and step 4, giving an emulation analysis report of comprehensive geometric errors of the machine tool, and modifying corresponding part tolerance values. The tolerance design method provided by the invention is used for tolerance design of the multi-axis machine tool parts.

The invention relates to a related ellipsoidal model-based expandable antenna unfolding arm joint tolerance design method. According to the method, a coordinate conversion matrix from a reflector on the end part of an unfolding arm to a satellite coordinate system is established firstly; and meanwhile, a tolerance-cost relation is obtained through research analysis. Specific to the overall structural form of the unfolding arm, various errors in the multi-stage unfolding arms are classified based on correlation; meanwhile, specific to each type of errors with internal correlation, an ellipsoidal mathematical model which represents the correlation is obtained through tests; next, Monte Carlo random sampling is performed in the ellipsoidal sphere, and a final angle error of the reflector is obtained based on the coordinate conversion matrix; and finally, by taking the total cost minimization as the object, by taking tolerance as a design variable, and by taking pointed error for satisfying design requirement as the constraint, tolerance optimization design is performed. A simulation structure shows that effective unfolding arm joint tolerance design can be realized by the method, andmeanwhile, design difficulty of the conventional method caused by no consideration of the correlation is avoided.

The invention belongs to the technical field of assembly tolerance specification design and computer-aided tolerance design (CAT), and particularly relates to an assembly tolerance specification intelligent design method based on Ontology. The method specifically comprises the following steps: (1) constructing a body of an assembly tolerance specification; (2) establishing an SWRL reasoning rule of an assembly tolerance specification; (3) extracting related tolerance information of the assembly tolerance specification; (4) constructing an assembly tolerance specification instantiation ontologymodel; and (5) combining the Jess inference machine with the SWRL rule, inferring the assembly tolerance specification, and outputting a result inference result. An ontology reasoning knowledge framework for the assembly tolerance specification domain knowledge is constructed by utilizing an ontology, and an assembly tolerance specification knowledge base is expanded according to dominant domainknowledge reasoning implicit knowledge. In combination with a semantic network rule language rule base, reasoning design parameters of assembly tolerance specifications for specific design of geometric products and using environmental conditions. The consistency knowledge description framework of the assembly tolerance specification can be provided, so that a computer can automatically select appropriate tolerance principles, tolerance types, size parameters and the like according to shape and size parameters of geometric products, and a quick and effective method is provided for intelligent design of the assembly tolerance specification.

The present invention provides an intelligent manufacturing method driven by rational tolerance design. The intelligent manufacturing method comprises the steps of determining key physical parameters capable of effectively reflecting corresponding product quality for a manufactured target product, and establishing a corresponding optimization model; verifying the optimization model; determining critical dimensions and non-critical dimensions which influence the product quality; establishing a multiple discipline optimization problem, respectively optimizing the critical dimensions and the non-critical dimensions, and generating an optimization result; and adjusting manufacturing processes of the critical dimensions and the non-critical dimensions according to the optimization result. According to the intelligent manufacturing method, first, the relation model of the product quality and the dimensions is established, critical factors and non-critical factors which influence the product quality can be effectively determined through determining the critical dimensions and the non-critical dimensions which influence the product quality, so that the product quality and cost can be targetedly controlled.

The invention relates to an optimized design method for the initial size of a thin-wall structure for wings and a body of an aircraft. According to the method, the scheme of a thin-wall stiffened plate for the wings and a body of the aircraft in the early stage of the project is determined based on a thin-wall project beam theory. The design of the initial size of the thin-wall stiffened plate isa work with challenge and judgment property, and the subsequent design work is directly influenced when the initial size designed and defined by the scheme is reasonable or not. The ideal thin-wall structure needs to adequately meet the design requirements of static strength design, fatigue damage tolerance design, manufacturing, maintaining and the like. By simplifying any one of an analytical method or a to-be-analyzed structure in the design process of the initial size, the cost benefit of the project can be increased. By further introducing manufacturing and maintaining requirements in thepremise that the static strength requirement is satisfied under the condition that the strength requirement is satisfied, the relatively optimized initial size can be acquired. By defining the initial size of the structure according to the design requirements of manufacturing, maintaining and the like under the condition that the strength requirement is satisfied, the optimized design method canmeet the lightweight design requirement of the structure, and the design efficiency is improved.

The invention discloses a vehicle body auxiliary clamping method for assisting a robot in automatic arc welding. Aimed at separated supplied parts existing in welding of a vehicle body, the method comprises the following steps that the resilience deformation at a welding seam position of an assembled body after welding is firstly calculated according to the manufacturing deviation of the suppliedparts, and on the premise that the value meets the design requirements of tolerance, an auxiliary tool clamp is used for clamping the supplied parts; and through deviation source data input of the manufacturing deviation of the supplied parts, clamp positioning errors and the like, a welding seam position adjustment optimization model is constructed, the optimal clamp deviation compensation amountis obtained, the welding seam position is adjusted through the auxiliary tool clamp, and the arc welding robot is guaranteed to conduct welding successfully. According to the method, the arc weldingrobot can be used for accurately performing automatic welding on a target welding seam conveniently according to a preset program, the production efficiency is improved, the manufacturing cost is reduced, and the method has excellent engineering application value.

The invention provides a system and a method for optimizing the tolerance design of a power circuit. The method comprises the following steps: setting corresponding transmission functions and parameters needing to be calculated according to different circuits; obtaining a plurality of types of elements corresponding to a circuit, all models of each type of elements and corresponding parameters; calculating standard error values corresponding to all models of elements in each type of elements according to a standard error value calculation formula; comparing the standard error values corresponding to all models of elements in each type of elements, and determining the model with a maximum error value; substituting the parameters corresponding to all types of elements of the model with the maximum error value into the transmission function for calculation, and judging whether the elements accord with the standard; outputting a judging result. According to the system and the method for optimizing the tolerance design of the power circuit disclosed by the invention, data search, input and calculation are completed by utilizing programmable software, so that the manpower and time are effectively saved, and the degree of accuracy is improved.