RU1787747C - Method of ball machining - Google Patents

Description

The ball is accompanied by rolling along the annular groove and rotating in a plane perpendicular to the circumference of the average diameter of the groove and passing through the center of the ball. Such kinematics of the balls in the working area ensures uniform application of traces of processing on the spherical surface of the products.

In FIG. 1 shows a diagram of the implementation of the proposed method 7 of the processing method — balls, longitudinal section; n | figure 2 is a view of the working surface of the lower disk (the position of the upper disk is shown by a dotted line); figure 3 - the position of the ball in the annular groove ..

The proposed method of processing balls includes the rotation of the processed ball 1 by the lower drive disk 2 and the upper flat drive disk 3, the distance between the axis of rotation of which He and Ov is equal to e. On the lower disk 2 there are annular grooves 4 of average diameter D, the centers of which are located on a circle radius R. In each groove 4 place one ball 1.

Disks 2 and 3 rotate with angular velocities WH and ОДз, wherein: their ratio depends on the values of e, Jj, D. Due to the difference in speeds VH and VB of the contact points of ball 1, respectively, with the lower 2 and upper 3 disks, it moves along annular groove 4. .. -: / ..

Ball made a single revolution in the annular groove in one, lower disk revolution,; if its center will move along the groove with an average diameter D with a velocity of Ush .0.5 (It is D. The speed of movement of the point of contact with the ball of the upper disk relative to the lower disk V0tn | VB - VH should be at least 2USh D (since the center the ball moves at least two times slower than VOTH.) Moving the ball along the entire length of the annular groove is possible if the vector 7 is constantly changing its position relative to the vector VH. To do this, it is necessary that the disks rotate in one direction and at maximum distance annular groove from center of the upper disk (R + e) its linear speed exceeded the linear speed of the lower disk, and at a minimum distance (R - e) it would be lower than the speed of the lower disk (vector. VOTH in this case makes a complete revolution around the end of the vector VH in one revolution of the lower disk ). The above conditions can be written in the form of inequalities: 0) B (R + e) -; - WM R f (D; WnR - a) B ((R e) (D. and therefore

(Is he

sh sh

(y

R + e R + D R -e

R-D

The range of possible ratios of the angular velocities of the lower and upper disks can be determined by the expression:

R -e

(Ov

R + e

D

2

R-D yy R + D

If the ratio (does not fall within the indicated range, then the ball does not move along the entire length of the groove, but along a certain portion thereof. The groove wears unevenly along the length, which leads to a decrease in machining accuracy;

The numerical values of the limits of the range of the sleep / a ratio are determined from the following considerations. The maximum distance between the axes of the disks e cannot be greater than the radius R of the circle on which the centers of the annular grooves are located. The minimum value of the average diameter D of the annular groove may be zero (the annular groove turns into a hole). Substituting the limiting values of E and D in the above ratio, we obtain the angular velocities of the lower and upper disks;

(Uv

The position of the ball in the annular groove is determined by the direction and magnitude of the relative velocity, the displacement of the contact points of the disks with the ball. The ball will be in the groove at the point at which the projection of the VOTH vector onto the direction of the vector / w is equal to 2USH. (3). The angle: a between the vectors Vsh and VOTH is determined from the expression: 2 Vch CD D

 rel. VOTH

The same angle y is the radius of the groove drawn to the center of the Osh ball with a straight line perpendicular to the VOTH vector and passing through the center of the groove Ok.

Thus, when the lower and upper disks rotate in the indicated range of angular velocities, the ball moves along the annular groove, making one revolution around its center for each revolution of the lower disk. Since the relative velocity vector is directed at an angle to the velocity vector of the center of the ball, the latter performs multiaxial rotation in the working area, which ensures high precision processing.

Examples of the method.

Fine grinding of balls with a diameter of 5.5 mm made of glass grade K8 was carried out. The initial size of the balls is 0.1 mm; the deviation from the spherical С0 - - shape is 0.06 mm. The tool kit consisted of two disks made of LS 59-1 brass. On the lower disk, annular grooves with a diameter of 15 mm were cut at a distance of R 45 mm from the center of the disk. The distance between the axes of rotation of the discs is e 25 mm. Processing was carried out in three transitions with a decrease in the granularity of the white electrocorundum abrasive powder from M 28 to M 10. The processing time at each transition was 40 minutes. The range of possible ratios of the angular velocities of the lower and upper disks for these values of e, R, D is 0.7-1.1.

PRI me R 1. The angular velocity of rotation of the lower disk is set equal to 6.6 from the upper disk - 9.4 (Yun / a 0.7). The size of the balls in the party was 4.3 μm, the deviation from the spherical shape

- 1.9 microns.

 Example. The angular velocity of rotation of the lower disk is 6.6, the upper disk

-6.9 ((UnLuv 0.95). The size of the balls was 2.5 microns, the deviation from the spherical shape was 1.1 microns.

PRI me RZ. The angular velocity of rotation of the lower disk is 6.6, and the upper one is 6.0 (1.1). The size of the balls was 3.2 μm, the deviation from the spherical shape of 1.4 μm.

Thus, the best accuracy parameters of the balls are achieved when

5

0

5

0

wearing angular velocities of the lower and upper discs close to unity.

To compare the proposed method for processing balls with a prototype, we present the results of thin grinding of balls with a diameter of 5.0 mm made of glass grade K8. The tool kit consisted of two brass discs: the upper one was flat. and lower - with concentric annular grooves, abrasive material - white aluminum oxide M 10. The best precision; the parameters of the balls, achieved in a known manner, were as follows: various sizes 4.5 microns, deviation from the spherical shape - 2, 0 microns.

Claims (1)

SUMMARY OF THE INVENTION A method of treating balls in which the upper and lower discs are eccentrically mounted, rotate them and place the balls in the annular grooves of the lower disc a and gf and press them with the upper flat disc, which means that in order to improve the quality and precision machining, the lower disk is taken with ring grooves of the same average diameter, the centers of which lie on the same circle. The disk in each groove is placed on a ball, while the disks are rotated in one direction, and the ratio of their angle O velocity conditions selected from where is the dream and (ov 35 - angular rotational speeds of the lower and upper disks, respectively. Editor Compiled by K. Schetnikovich Tehred M. Morgenthal Corrector O. Kravtsova