SU727336A1 - Opening working method - Google Patents

Description

(54) METHOD FOR HANDLING

one

The invention relates to the field of metalworking and can be used in the boring of parts on machine tools, mainly boring.

There is a method of processing holes, in which the axis of the pre-treated surface is shifted from the axis of the shpindl of the tool J.,

The purpose of the invention is to improve the accuracy of the surface shape.

This is achieved. According to the proposed method, the direction of displacement is chosen to coincide with the direction of the resultant diagram of the absolute values of the difference between the stiffness of the AIDS system depending on the angle of rotation of the spindle and the arithmetic average value of the system stiffness in the same cross section, processing.

FIG. 1 shows a diagram of the implementation of the proposed method on a horizontal boring machine; in fig. 2 is a diagram of the stiffness of the AIDS system in FIG. 1 depending on the angle of rotation of the spindle; in fig. 3 is a plot of the absolute values of the difference between the rigidity in FIG. 2 and the arithmetic mean value of the system stiffness; in fig. 4 is a schematic representation of a method for a boring machine.

When boring a hole on a universal horizontal boring machine, the workpiece 1 is set on the table 2, which carries out the movement of the longitudinal feed. The cutter 3 rotates with the boring pin 4 mounted on the spindle. The spindle headstock 5 installs moves on the front pillar 6 of the machine.

The plot of the rigidity of the considered AIDS system, depending on the angle φ of rotation of the pinchpin (Fig. 2), is constructed using well-known techniques. The radius of the circle plotted on the plot is equal to the average

5 arithmetic value of system stiffness

Jcp -y- (Jf + Ja + - + Jn),

where J 1 - the rigidity of the system when the horizontal position of the cutter (J i 0);

J 2.- the same, when turning the spindle on

TYAO about

angle J and counterclockwise;

Claims (2)

 however, when the spindle is rotated at an angle L „(n-1). The plot of the absolute values of the difference between the rigidity of the system depending on the angle of rotation of the spindle and the arithmetic mean value of the rigidity of the system (Fig. 3) is built on a circle of radius Jcb. For example, IAJ, | | J, -J ,,, |; l AJ2l | Ji-J 4.1. The direction J of the resultant of this plot is found by summing the n vectors (DL if, I DLg., ..., 1A Jr, 1 in a known manner. The direction Jj can also be determined by a similar analysis of the pliability curve of the AIDS system. After the pretreatment, the holes in the workpiece shift the last in the Jji direction relative to the spindle axis so that the distance between the pre-machined hole axis O and the spindle axis Osh is -6 (Fig. 1). If the pre-machined hole diameter DJ. is bored to diameter D, then the specified The repetition of the 2t DD operation and to ensure that the entire surface is treated without blackness is necessary that -t t. The allowance removed in this case is shaded in Fig. 1. Fig. 4 shows an example of the implementation of the proposed method on a machine, for example, a finishing boring machine, which characterized by a rigidity of knots close to uniform in the angle of rotation of the spindle. However, the workpiece 7 has a pronounced local deviation of stiffness from the uniform, which leads to a local deviation of the stiffness of the AIDS system from uniform in the angle of rotation of the spins ate. In this case, there is no need to search for the direction of the resultant diagram of the absolute values of the difference between the stiffness of the system depending on the angle of rotation of the spindle and the average value of the stiffness, since it coincides with the direction of the greatest deviation of stiffness from its average value. When boring a hole with a diameter D in the workpiece 7 with a cutter 8 installed in a rotating boring mandrel 9 mounted on a pin, the desired direction of displacement is found from an analysis of the shape of the workpiece and the position in which it is installed on the machine. FIG. 4 this direction runs horizontally from the axis Osh of the spindle to the place of the workpiece with the smallest rigidity, i.e., to the left, where the O предварительно axis of the previously machined hole with a diameter Dj is shifted. from the spindle axis by the value (D-Dj) 2. The pre-machined surface of the workpiece can be displaced from the spindle axis of rotation by appropriate processing of the workpiece 7 in a preliminary operation. Ovality of the bore surface caused by unequal elastic spins of the system during one revolution of spindles 0- KYI + YS) - (Yi + Yiv), (1) where 1, .-, y-elastic spring; systems of AIDS in the four spindle angular positions with an interval of 90 °. In turn, Jt (2) where is the radial component of the cutting force in the i-th spindle angular position; Ji - stiffness of the AIDS system in the same spindle position. If, as the first angular position of the spindle, to accept the one shown in FIG. 4, for the workpiece 7, the rigidity Jl Jli Jl JjE- (3) When boring with a uniformly distributed allowance Pyi Rui. Rji and according to the formula (2) taking into account the expression (3) YI YlT Yfa YE. leading to ovality. Since the relationship between the depth of cut and the radial component of the cutting force is close to linear, when the workpiece is shifted to the left by the value of {t, the components Pyi 0; Ru Rui P (fi. Pall + PSS, Taking into account the expression (3), the ovality calculated by the formula (1) is zero. Consequently, the displacement of the workpiece by the proposed method by the value of t does not exclude the ovality of the bore surface completely, but reduces it by comparison with a uniformly distributed allowance. If a blank is bored, for which in the first spindle angular position the stiffness of the AIDS system also differs markedly, but upwards, then Jl JIT Jg JiE, and with an even distribution of the allowance YI YE YE YJI with an oval exit And in this case, the displacement of the workpiece by the magnitude -tt in the direction of the cross section with extreme rigidity reduces the Ruth component to zero and doubles the Ruy component, reducing the calculated ovality to zero. The results of the proposed method are similar with the more complex nature of changes in the rigidity of the AIDS system, for example, as graphically depicted in FIG. 2 .. Claim of the method of processing holes, in which the axis of the pre-machined surface is displaced from the spindle axis of the tool, characterized in that, in order to increase the accuracy of the surface surface being machined by thin boring under conditions of non-uniform rotation angle of the spindle stiffness of the AIDS system, the direction of displacement choose coinciding with the direction of the resultant diagram of the absolute values of the difference between the rigidity of the AIDS system depending on the angle of rotation of the spindle and the average arithmetic value iem stiffness of the system in the same cross section, and the shift is performed within the allowances for processing. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 205497, cl. 23/35/00, 1965. . Aer.