Rational reduction of work in progress when assembling parts of a product using the group interchangeability method

The article discusses the method for interchangeability method. To reduce the volume of work in progress, the design of a fixed combined compensator is developed, which provides stepwise regulation. The article reducing the work in progress by stepwise regulation in multilink dimension chains when assembled using the group proposes a rational technology for the use of combined compensator, taking into account the peculiarities of the group interchangeability method. In order to reduce the work in progress during assembly using the group interchangeability method, two ways of using the combined compensator have been developed: 1 - the inclusion of a compensator in each dimensional chain collected by the group interchangeability method; 2-application of the compensator only at the stage of formation of work in progress during group assembly by replacing one of the parts with it. The peculiarity of the methods is the use of the informational advantage of group assembly — information about the actual dimensions necessary for sorting parts into groups. This eliminates the step of measuring the closing link during assembly and simplifies the design of the compensator, reducing the number of control steps.

Determination of the parameters of typical multi-link dimensional chains (closing link is tension) using recurrent dependencies

The existing approach to the use of the group interchangeability method during assembly, which are concentrated, has a number of significant drawbacks: 1) there are no formulas for calculating the upper and lower deviations of the component parts of the dimensional chain; 2) deviations are selected without taking into account the design of the component links (the method of equal tolerances is used); 3) the method is applicable for the number of links no more than three with a small number of groups. For other types of problems there is no algorithm, mathematical apparatus, and examples of calculation are not considered sequentially; 4) the calculation by the group interchangeability method is limited by the condition of equal tolerances, i.e. excluding compensators and compensating properties of materials as a part of mechanisms; 5) the calculations are based on assumptions about the economic feasibility of increasing the closing link by a factor of n without taking into account the feasibility of such an increase in the component links that is not permissible in complex mechanisms; 6) the size of the batch of parts and the volume of work in progress are not reflected, as one of the factors of economic feasibility of establishing production tolerance. In this regard, it is necessary to improve the method of achieving accuracy by group interchangeability. This article discusses typical problems that rise when solving dimensional chains in which the closing link is a tension.

PRACTICE OF DIMENSIONAL IN THE IMPLEMENTATION OF THE METHODOLOGY OF GROUP INTERCHANGEABILITY

The subject of consideration in this article is the process of modeling the dimensional relationships at the Assembly stage using a single-circuit graph size scheme, which describes the mechanism of the individual parts of the conjugation in the implementation of the Assembly area group interchangeability methodology, reflecting the specific conditions of production. In the context of dimensional modeling, calculation procedures are considered on the basis of the developed mathematical model, which can be applied to both single-circuit and multi-circuit size schemes with dependent size chains. In particular, for the conditions of large-scale production, the algorithm for determining the scattering field of the assembled parts sizes by sorting them into size groups is considered. The design procedure is considered on the concrete example which describes a variant of completing of details with rather wide tolerances in the Assembly unit meeting the set criterion of working capacity.

THE INCREASE IN DRILLING DURABILITY OF TRICONE BITS

The process of location error the bit in the chuck was verified experimentally and put into production by measuring the gap between the working surface of the limiting ring and the calibrating surface of the cutter to improve the accuracy of the bit production. Bits having a diameter close to the lower limit value can be processed in a cartridge with a restrictive ring of reduced diameter. The height of cutters is reduced as a result of introduction into production of the method of group interchangeability of sections in height, measured in a direction parallel to the axis of the bit.

Method of axial adjustment for precessional transmissions

Axial adjustment method for precessional transmissions includes compensation error calculation, determination compensator groups, achieved in the form of base and auxiliary rings. The compensator has on the base ring axial canals in which can be placed clamping bolts but the auxiliary ring has axial holes for the screws. The auxiliary ring is formed from increasing sectors - the distance between auxiliary ring stairs and front side of body, from decreasing sectors - the distance between base ring and bottom place, and the closure element - the clearance between gear body and the front surface of the base ring. According to the method of group interchangeability is determined the deviation value of the upper and lower group tolerance and the clearance between lid and body. Then rotating one of the rings is ensured the dimension of the compensator which must match to compensation clearance value and then the compensator is adjusted to required value.