The effect of the relative vibrations of the abrasive tool and the workpiece on the probability of material removing during finishing grinding

OBRABOTKAMETALLOV Vol. 23 No. 3 2021 MATERIAL SCIENCE EQUIPMENT. INSTRUMENTS 4 1 2 Results and Discussion The calculation of the probability of material removing in the presence of vibrations in any area of the contact zone with a known initial state of the surface is calculated by substituting the indicator ( , ) a y a   from expression (14) into equation (4) taking into account the parameter , for each of the cases when the initial phase is: 0(2 ) y    (15); y    (16); 0(2 ) y    (17); 0(2 )    (18). For clarity of the calculation procedure, let’s consider a numerical example. Let’s calculate the probability of not removing and the probability of removing the material when grinding holes with a diameter of 150 mm in workpieces made of titanium alloy VT3-1 with a tool AW 60 × 25 × 13 63C F90 M 7 BA 35 m/s (at a wheel speed of 35 m/s, a workpiece speed of 0.25 m/s, longitudinal feed – 33 mm/s, transverse feed – 0.005 mm/stroke). From the calculation of the balance of displacements [20], we determine that for the given processing conditions 6 11.54 10 m f t    . Based on the research data [20, 21, 22], we accept: = 0.9 m c K ; 6 = 7.31 10 m z    ; 2 = 15.86 grains/mm z n . For the considered conditions 4 =3.397 10 m y L   , 628 rad/s   , 100 Hz   . The calculation is performed according to equations (2), (3), (4) for the level 6 10.38 10 m y    at 0.8 2 y L z   , = 0.2 f A t . Let’s calculate the parameters y u z V      and y y u L V      for the cases when the initial phase is equal to 0 y   : 4 628( 0.136 10 ) = 0= 0.341, 0.25       –4 628 3.397 10 0 0.853 0.25      Отсюда получим sin 0.3344    , cos 0.942   , sin = 0.753  , cos 0.658   , sin2 = 0.63   , sin2 = 0.991  . After substituting the numerical values of the parameters in (15), we obtain:   -6 -6 4 3 3 3 4 5 3 5 0 2 2(11.54 10 10.36 10 ) (3.397 10 ) ( 0.136 10 ) (3.397 10 ) ( 0.136 10 ) 3 0.1 5 0.1 Y                          2 2 3 4 6 6 6 0.136 10 +3.397 10 2.308 10 +2 11.54 10 10.38 10 2                     6 2 6 2 4 3 2 (2.308 10 ) 0.25( 0.63+0.991) 4 2.308 10 0.25 3.397 10 0.942 ( ) ±0.136 10 0.658 4 628 0.1 628                      6 2 2 6 6 3 2 2.308 10 0.25 2 0.25 + 0.1 628 11.54 10 10.38 10 ( 0.3344 + 0.753) 0.1 2 ) 6 8 (                   6 4 2 3 2 15 2 2.308 10 0.25 (3.397 10 ) 0.3344 ( 0.136 10 ) 0.753 = 1.22 10 0.1 628                 . Then, according to equation (14), we calculate the value of the indicator, taking into account vibrations ( , ) ( , ) a y a y z   : 6 6 15 6 3/2 3 3.14 15.866 10 1 2 7.31 10 (35±0.25)1.22 10 ( , ) = 0.282 8 0.25 (11.54 10 ) a y z               .

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