Micromechanical aspects and ways to increase the efficiency of the compounding process of dispersed materials

Abstract

The article solves the current scientific and applied problem of algorithmization of calculation of smooth limit gauges intended for control of holes in mechanical engineering, using modern digital design methods. It is substantiated that in the conditions of transition to the concept of "Industry 4.0" traditional deterministic methods of calculation of parameters of the control tool need to be supplemented with probabilistic models to ensure the reliability of geometric control.

The authors have developed and formalized a normative algorithm for determining the limit sizes of through and non-through gauges, which is based on the requirements of national and international standards DSTU ISO 286 and ISO 1938-1. The algorithm is presented in a structured tabular form, which allows it to be easily integrated into computer-aided design systems (CAD) and quality management systems based on spreadsheet processors. Particular attention is paid to the unambiguous determination of the limits of manufacturing tolerances and wear of the through gauge as basic parameters for further digital modeling.

The scientific novelty of the work lies in the development of a risk-oriented probabilistic model for estimating errors in attributive control. Unlike the classical approach, where the wear allowance is considered as a fixed geometric margin, the proposed model takes into account the stochastic nature of the technological process (variation of the sizes of parts in the batch) and the random nature of wear of the working surfaces of the gauge. The use of the normal distribution function made it possible to establish a mathematical relationship between the current state of the gauge and the probability of passing a defect (consumer risk).

The author's method for determining the operational limit wear of a through gauge is proposed, which is based on establishing an acceptable risk level . This allows us to move from formal removal of the tool from operation to reasonable management of its resource depending on the criticality of the controlled connection and economic factors. An economic interpretation of the results in the context of risk management was performed in accordance with the principles of DSTU ISO 9001:2015, which shows the impact of control errors on the total production costs.

Practical testing of the method on the example of calculating calibers for controlling the 30H7 hole confirmed that the risk-oriented approach provides higher reliability of control in conditions of drift of technological process parameters. The results of the study can be implemented at machine-building enterprises for digitalization of metrological support and optimization of costs for control tools.