Patent GB-1232980-A (GB)
IPC: B24B33/02
Filed: 1968-06-08
Abstract: 1,232,980. Honing. WERKZEUGMASCHINENKOMBINAT "7, OKTOBER" BERLIN VEB. 8 June, 1968, No. 55886/67. Heading B3D. In a control system for the rectilinear direction-changing movement of a grinding tool or workpiece, a measuring device delivers signals in accordance with predetermined concentric "oversize" zones to determine the reversal of the working stroke at an "oversize" portion of the workpiece lying within the "oversize" zone adjacent the tool, the machining steps comprising machining the "oversize" portion, consecutively repeating such reversal of the working stroke for each other workpiece "oversize" portion lying within the zone encountered throughout the length of the workpiece and, if necessary, repeating the operation for further workpiece "oversize" portions lying within the next adjacent "oversize" zone. Fig. 1 shows the bore of a workpiece to be honed, the deviations from the cylindrical being divided into "oversize" zones 28-31 which are predetermined by adjustments made at the measuring device, the latter delivering an L signal or an O signal depending on the direction of travel 1 or 2 of the tool carrier. The signal is received by the control system, Fig. 2, which consists of a counter 3 having binary places 4, 5 and a counter 6 which has binary places 7-11 corresponding to the "oversize" zones 28-31 and is associated with logical connecting elements. In operation, at each L signal produced by movement in the direction 1, the counter 3 counts on by one binary place and transmits an L signal to an AND-gate 12. A further L signal is passed from the measuring device to the AND-gate 12 when a workpiece portion located in the oversize zone 28 is reached, the two signals to the AND-gate being applied through an OR-gate 16 to stores 17, 18. The L signal is stored at 17 since the input signal reversed by a negator 23 is applied as an O signal to its erasure input 20; the L signal is not stored at 18 since it is applied as an L signal to its erasure input 22. Movement in the direction 2 produces no change in the counter 3. As soon as the workpiece portion located in the region 28 is left behind, the L signal is erased from the AND-gate 12 and from the stores 17, 18 via OR-gate 16, the O signal thereby produced being reversed by a negator 24 and applied as an L signal to AND-gates 25, 26; the two L signals are therefore applied to the AND-gate 26 and one O signal plus one L signal to AND-gate 25 so that an L signal from the AND-gate 26 is transmitted to the control device which limits the work travel and causes the tool carrier to change direction immediately. The binary places 4, 5 of the counter 3 are erased via an OR-gate 27. The machining is repeated until the workpiece portion located in the region 28 has been removed; with no further L signal being delivered from the area just machined, the tool carriage continues its movement between pre-determined reversal points. If in doing this further workpiece portions projecting into the region 28 are encountered, the machine then operates on that area. When all the workpiece portions projecting into the region 28 have been removed, the counter 3 ceases to be erased and counts up the next binary place 8 of the counter 6, the next region 29 then becoming operative by means of an AND-gate 13. When all the regions have been machined, the binary place 11 of the counter 6 terminates the work process. During the entire procedure, the tool is resiliently urged into engagement with the workpiece but machining is only carried out on the "oversize" portions as controlled.