SU1491679A1 - Method of controlling the process of grinding of discontinuous acylic surfaces - Google Patents

Abstract

The invention relates to a machine tool industry, in particular, to grinding round parts with an automatic cycle. The purpose of the invention is to improve the accuracy and productivity of processing by automatically choosing a control method depending on the presence and size of the cavity in the parts. At the beginning of the grinding cycle, the CNC system performs the movement of the grinding wheel. After touching the wheel and the part (or at a given coordinate), the feed rate is switched. After the end of the draft feed, the counting time for finishing feed begins. At a given point in time, the active control device (PAK) turns on. If at the moment of switching on, the PAC does not immediately issue the command "End of finishing feed", then control is transferred to the PACK, i. before issuing the "size ready" command. If, at the moment of switching on, the PAC immediately issues the command "End of finishing feed", then control continues to be performed by the CNC system until the end of the finishing grinding stage. 2 Il.

Description

The invention relates to a machine tool industry, in particular to grinding round parts with an automatic cycle.

The purpose of the invention is to improve the accuracy and productivity of processing by automatically selecting the control method depending on the presence and size of the cavity in the details

Fig. 1 is a block diagram of an apparatus for carrying out the method; FIG. 2 shows a defective section giving a false command. Size is ready.

The control method is as follows.

At the beginning of the grinding cycle, control is performed by the CNC system to move the grinding wheel. After touching the wheel and part (if fio a predetermined coordinate), the feed rate is switched, for example, from forced to rough. At the end of the roughing (this time is set in advance by the TNC by the corresponding coordinate), the counting time for finishing feed begins. This count can be carried out both in time and in the coordinate of the movement of the grinding wheel, since the feed rates are set in advance

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but

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and with a sufficient degree of frequency, accuracy may be considered constant. After a predetermined period of time has elapsed (or when a predetermined coordinate has been reached), the active control device (PAK) is turned on (PAK is installed on the part earlier, usually simultaneously with the end of the draft feed). The time (or coordinate) of the inclusion is chosen so that the grinding is still continued at the finishing feed (this time or coordinate is easily determined from the given allowances for finishing grinding and the feed speed).

If, at the moment the PAK is turned on, it does not immediately issue the End Finishing Feed command, then the control of the encryption process is transmitted by the PAK, which controls the machine’s working cycle to the end, i.e. Up to the team Size is ready. In this case, the adjusted size of the finished part, i.e. the corrected coordinate of the final position of the grinding wheel under the condition that the finished part size is obtained taking into account stress, thermal deformations and the condition of the wheel at a given moment.

If, at the moment the PAK is turned on, it immediately issues the End Feed command, then the grinding process continues to be controlled by the CNC until the end of the final grinding stage. In this case, after the end of the finishing stage and the beginning of the finishing grinding, a new countdown of time (or coordinates) begins and as soon as the predetermined value (or coordinate) is reached, the ACL is turned on again. This time (or coordinate) is chosen so that the grinding still continues on the finishing feed.

Then everything happens as in the above described stage of final grinding.

If a more complex grinding cycle is organized, the indicated sequence of switching on the PAK and the I transfer of control to the PAK or the CNC system can be carried out at each stage or at several (or only one) of the latter.

If the control is not transferred to the PAK until the end of grinding, then the end of the process will come when the system

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The CNC will issue the Size Ready command, which will correspond to the coordinate of the grinding wheel at the time the finished part is produced in the previous (or in one of the previous) grinding cycles.

Thus, parts that have sinks (depressions) smaller in depth than the machining allowance will be treated like parts that do not have such depressions, i.e. on the device active control. Parts that have depressions that are larger in depth than the machining allowance will be processed in accordance with the coordinate of the grinding end corresponding to the last part that was machined with PAK.

The block diagram of the device contains a mechanical part of the machine 1 with drives mounted on it, connected by a communication channel 2 to an executive system 3, which in turn is connected by a control channel 4 to a control system 5 and channel 6 to an automatic control selection unit 7 .

The control system automatic selection unit 7 has the following communication channels: channels 8 and 9 with the control system 5, channels 10 and 11 with the control unit 12 by the time of the final command, channel 13 with the time reference device 14 and the active control device (PAK) 15 With channels 16-17, block 12 is connected to device 14 and PAK 15. Sensor 18 is connected to PAK 15 by channel 19.

The device works as follows.

The control system 5 through channel 4 sets the executive system 3 for speed (feed) at all stages of processing, and for channel 8, the amount of movement for each feed (allowance). At the beginning of the machine operation, the commands of channel 8 freely pass block 7 and enter channel 3 into system 3 for their implementation by drives of machine 1.

After the transition from the forced feed to the draft from the control system 5, channel 9 and block 7 receive a command to activate PAK 15. In this case, from block 7, channel 13 receives the command to activate PAK 15 and the device 14, channel 8 commands are blocked, instead of them go commands

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from 15 through channel 17 through block 12 further through channel 10 through block 7, channel 6 to the executive system 3. In parallel, a command is received from device 14 via channel 16 in block 12 to read the monitoring time set in advance. Sensor 18 through channel 19 issues the actual dimensions of parts to the PACK 15, and based on the measurements, the PACK 15 issues commands 17 through channel 17 to reach the transition points to the next mode.

If the Size command is not received in block 12 within the monitoring time, channel 11 is blocked, the entire grinding cycle is controlled by the above method. By the final Size command, the control system 5 is ready and adjusts its end processing value.

If during the control time, the value of which is less than the time of the full grinding cycle, passes the Size ready command, then in the PAK sensor operation area there is a defective section of the workpiece (Fig. 2). In this case, the block 12 blocks the channel 10, which prevents the control system 5 from misleading the position of the final command, while at the same time the channel 11 sends the command to switch control from the ACC 15 to the system 5. 8 through block 7 is connected to the channel 6 and cycle control is maintained by system 5.

Thus, the machine control system is automatically selected to prevent the output

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from the machine of the unfinished part and the false correction of the value of the control command when there is a fault in the measured PAK section of the defect.

Claims (1)

Invention Formula The method of controlling the process of 10 fanning discontinuous non-cyclical surfaces, including the measurement of the part and the setting of transition points from one stage of the cycle to another at a time of reaching the size, which is due to the fact that, in order to increase the accuracy and productivity of processing, preliminarily set threshold values 2d to proceed, respectively, to the stages of the cycle and assign the control time to reach the specified threshold values of intermediate sizes, measure the actual size of the 25 hoists at the appropriate stage of the cycle and in the case when it detects the achievement of the first of the specified threshold values before the designated control time, 30, the further grinding of the part continues without moving to the next stage, and the cycle control is carried out by the amount of movement of the grinding wheel, and in the case where 35 in the actual measurement of the part when the control time is reached, the achievement of the first of the specified size thresholds is not recorded, further grinding control 40 and cycle switching is performed upon reaching the predetermined threshold values of the intermediate dimensions of the part. 03g.1 Finished size for roughing & ravotke Finished size with finishing Natechki Datchin PAK