SU753609A1 - Method of coinciding tool-oscillation axis with groove profile centre - Google Patents

Description

This invention relates to a technology for the finishing of parts such as ball bearing rings and can be used in machines for finishing the grooves of ball bearing rings. There is a method of aligning the tool swing axis with the center of the groove profile, in which the sensor follows the sensor to radially release the tool, memorizes signal values, compare them and form commands to execute correction movements of the tool axis relative to the groove profile 1. The known method provides for the determination of the radial pressing of the tool at two fixed extreme points of the gutter profile, after which a correction movement is carried out proportional to the value of the difference of the spin at the extreme points. The disadvantage of this method is the limited accuracy of the combination, due to the need. to fix at each swing of the instrument its extreme right and left target position with an accuracy of 2-3% (20-30 arc-minutes), which requires sensors with very high accuracy and stability of operation, and also the fact that the interval between measurements is determined by the period swing bar and is 0.025-0.1 sec, which imposes very high demands on the speed of the system, which must determine the value of the signals and remember them during this interval, and that the comparison of signals at fixed points in time cannot provide high reliability, since the command is formed on the basis of only two measurements of the instantaneous value of the signal and the random short-term interference can be said on the measurement result. The disadvantage of this method is also the complexity of instrumental etching. The aim of the invention is to improve the accuracy of combination, as well as to simplify the hardware shaping. To achieve this goal, determine the value of the sensor signal during the measurement period not less than the duration of one double swing of the bar

(tool), after which they make a relative movement, repeat the 3s measure, determine the sign of the spacing of the subsequent and previous values and, with a positive difference, reverse the movement, and with a negative difference, move, measure and determine the signs of their differences until the signal reaches its minimum.

FIG. Figure 1 shows the relative arrangement of the tool axis and the center of the groove profile, which is changed during the implementation of the proposed method, as well as the block. the scheme of the device performing individual operations of the proposed method; in fig. 2 is one of the modifications of the device implementing the method; in fig. 3 shows a second modification of the device implementing the method.

Abrasive tool-bar 1, swinging about the swing axis Oj when superfinishing the groove of the ball bearing ring 2 with the m-m profile, having a center at the Oj point, must be moved along the X axis Hci, Oj 0, in order to align the swing axis with the center of the groove profile.

The magnitude of the mismatch 0 02 between the axis of swing of the tool and the center of the profile of the ring groove is due to the presence of the inevitable spread of the center of the ring groove relative to its base end. This variation is a consequence of the previous operations of processing the ring groove (grinding). Such an alignment will not be made when adjusting the glass before processing, because of uneven annealing of the tool, the gauge is fixed along the fixed axis, at the edges of the profile there will be no uniform metal removal and, thus, the desired groove profile in cross section and one of the edges of the gutter will remain unprocessed. In order to achieve the minimum required removal from the untreated side, it is necessary to drastically increase the total removal, which requires an increase in processing time several times. In addition, the tool will suffer more due to the increase in pressure on it on the one hand, which will also lead to a decrease in processing performance due to the need for more frequent tool changes.

Abrasive tool-bar 1, rolling around the axis Uj, processes the profile of the groove of the ring 2 ball bearing, which is the center of symmetry at the point Oj.

The rocking of the bar is carried out by the engine 3 connected by the V-belt drive 4 to the swing shaft 5, the finger .6 of which interacts with the fork 7. In the plug 7, the sleeve 8 is mounted, inside which the bar 1 is elastically pressed by the spring 9 to the profile to be processed. The bar 1 is fixed on the sleeve 10, having the possibility of relative movement along the sleeve 8.

To adjust the position of the axis ka of the bar relative to the center of the profile, a sensor 11 fixed at a moving bar 1 mounted in the holder 8 is measured by changing the spin of the bar along axis 0. The release value is a periodic function of the angle of rotation of the bar with a period equal to the double swing angle of the plug 7 and the associated bar 1. Therefore, the release of the sensor 11 is measured and its signal is determined for a time not less than the duration of one double swing. At some initial mismatch Oj 0. for a period of time not less than the duration of one double swing, the signal value of the sensor 11 is measured, it is memorized and immediately after that, using the actuator 12, the center of the groove 0 profile is moved relative to the swing axis of the Oj bar .

To do this, the motor 13 is used, which is connected via a gear train 14, 15 with a screw 16 interacting with a nut 17 made on the headstock of the product 18 on which ring 2 is based. A correction axis can also be made to move the swing axis Oj of the tool relative to the center Q profile gutter rings.

For this purpose, an engine 19 is coupled via a gear train 20 21 with a screw 22 interacting with a nut 23 formed on the tool head 24 carrying the tool. The relative correction movement after the first measurement is carried out by a step size, which is determined by the technological tolerance for the distance from the center of the groove profile to the base end for a particular size of the rings to be processed. After the step-by-step movement is performed, the signal value of the sensor 11 is again measured for a period of time not less than the duration of one double swing, the previous value is subtracted from it, and the sign of the difference is determined. To memorize the values of the signal from the sensor 11, to subtract them, and to determine the sign of the difference, use the block 25.

Claims (1)

If the sign of the difference is positive, i.e. the value of the subsequent sensor signal is greater than the value of the previous signal, then the second correction movement is performed already in the opposite direction with respect to the direction of the correction movement that was performed after the first measurement of the sensor signal, i.e. movement reversed. This is done with the help of the reversing drive 26. If the difference sign is negative, then the next correction movement is made in the same direction as the first one, using the actuator 12. In both cases, after the second correction movement has been completed, the knowledge the sensor signal is memorized; the sensor signal value is subtracted from it, the sensor signal value is memorized, the sensor signal value obtained from the measurement preceding this corrective movement is subtracted from it, and determine the sign of the difference. If the difference sign is not changed, then the correction movement in the same direction is repeated, the value of the sensor signal is measured again, the value of the previous signal is subtracted from it, the difference sign is determined. The sequence of operations is repeated until after the next movement the sign of the difference does not change to the opposite the second time. In this case, they are reversible with respect to the previous movement and complete the setting. When obtained as a result of these movements, the positions of the swing axis 0 | with respect to the center 02 of the groove profile of the ring 2, the signal of the sensor 11 will be minimal. The quantity that characterizes the signal (electrical voltage) of the sensor 11 can be used by the mean or maximum (amplitude) value of this voltage for a period not less than one double swing of the bar. The minimum of the above voltage values corresponds to the exact coincidence of the Oj axes with Oj. This method allows to increase the accuracy of alignment of the axis of swing of the bar with the center of the gutter profile, since random short-term changes in the sensor signal do not affect the magnitude of the signal that is established over a period of time equal to or greater than the period of the tool. In addition, by eliminating the need for high-precision and stable elements that fix the extreme positions of the instrument, which ensure the generation of a signal at discrete points in time corresponding to these extreme positions, the instrumentation required for implementing the method is greatly simplified. The method of aligning the swing axis of the tool with the center of the chute profile, which by means of the sensor tracks the radial squeezing of the tool, memorizes the values of the signals, compares them and generates commands to perform correction movements of the swing axis of the tool relative to the chute profile, the purpose of increasing the accuracy of the combination is to determine the signal value during the measurement period, not less than the duration of one double swing of the instrument, after which l dissolved relative movement, repeated measurement, determining the sign of the difference of the previous and subsequent values of difference and .polozhitelnoy reverses a movement, and if negative - repeated movement, measurements and determining the signs of the difference signal to achieve a minimum. Sources of information taken into account during the examination 1. Copyright certificate of the USSR No.-309796, cl. In 24 V, 1 9/06, publ. 1 971 W /