SU1411119A1 - Method of assembling parts of shaft-bush type - Google Patents

Abstract

The invention relates to the assembly industry, in particular to methods of assembling parts such as a vap-bushing. The goal is to improve the quality of the assembly by increasing the likelihood of mating products. For this, one of the assembled parts 2 is based. The second part 1 is placed relative to part 2 so that their axes are displaced one relative to another by an amount, where A is the amplitude of parasitic oscillations of one part relative to another, is the tolerance for positioning accuracy. The displacement of the axes of the parts significantly increases the time spent on the part. 1 in the field of tolerance for SG, which increases the likelihood of conjugation. 4 il.

Description

I1

S L - g-

/// /// /// /// /// tf

FIG.

L.J

///

The invention relates to robotics, in particular to methods for assembling parts such as a shaft-hub, mainly in instrument making.

The purpose of the invention is to improve the build quality by increasing the likelihood of mating parts,: FIG. The scheme of the assembly according to the proposed method is presented when the axes of parts are shifted; Fig, 2 is a graph of the oscillatory process when combining the axes of parts; on fig.Z - assembly diagram when combining the axes of parts; in fig. A is a graph of the oscillator of that process when the axes of parts are shifted.

The method is carried out as follows.

When coupling parts 1 and 2 between them, as a rule, pa- are observed: active oscillations arising from;} and engine work, mechanical friction, etc. In the event that the range 2A of these oscillations exceeds the tolerance value (f for positional accuracy (given by the dimensions of parts 1 and 2), the probability of matching to fall within (/) is low, which leads to frequent failure of work. The contingency of this is determined by 1) the magnitude of the fluctuations and the tolerance for the accuracy of the validation. The greater the residence time of part 1 within the cG tolerance, the greater the likelihood of mating parts 1 and 2.

Having mated parts 1 2 (fig. 3, 4), in which the center of oscillation (axis 0) of part I coincides with the axis of part 2, it is possible to finish with a relatively low time tC of part 1 being within L tolerance tf, and hence the bottom, Coi probability of conjugation. The time T is determined by the expression, + t2 + tg,

Having mated parts I and 2 (Fig. 1 and 2), in which the center of oscillation (axis 0) of part 1 is offset relative to the axis O of part 2 (

the displacement depends on the nature of the oscillations), it is possible to achieve a higher time T of the part I S within the tolerance field, and a trace - Telno, and a higher probability of conjugation. This is evident when comparing the graphs of the oscillatory process. In this case, considered the simplest form of oscillation - sine

ABOUT

five

0

0

five

far The magnitude of the displacement of the axes O and o in this case should be such that the position of the part 2 corresponds to the extreme position of the part 1. This allows you to achieve the maximum likelihood of conjugation and thereby reduce the number of equipment malfunctions.

In the case when the oscillations become more complex, the magnitude of the displacement of the axes O and O is determined from the condition of the maximum probability of falling within the tolerance field tf (from a mathematical point of view, the problem is typical).

PRI me R. The OA-127A robot performs the docking of the shaft 1 and the hub 2 of the stepping motor. The tolerance for positioning accuracy, based on the fit, is 30 microns. At the moment of splicing between them, a parasitic oscillatory process is observed. Its amplitude is 45-50 microns. The amplitude of oscillation was determined with a microscope. The nature of the oscillations was determined using a capacitive sensor located near part 2.

At the same time, the probability of docking is approximately 50% (out of 200 docking attempts, 104 are successful). It is practically not profitable to use a robot in this case.

With the displacement of the centers of the shaft 1 and the bushings 2 by 10–15 µm, the probability of their joining is approximately 70% (out of 200 joining attempts, 137 successful). At this probability, the performance of the robot provides the needs of production.

In the method, the magnitude of the displacement of the axes is determined by the ratio

X-A-A-A- -,

where A is the amplitude of oscillations of one part relative to another; o is the tolerance for positioning accuracy.

Claims (1)

Invention Formula The method of assembling parts such as a shaft - a sleeve, between which there is a parasitic sinusoidal oscillation, consisting in rigid basing of one part, combining the axis of the second part with the axis of the first one within the tolerance for positioning accuracy and subsequent matching of parts and with that, with tse- | - 1 0- (7 / X l t-t Fi9.2