SU930259A1 - Method of correcting grinding programme - Google Patents

Description

(54) METHOD OF PROGRAM CORRECTION

one

The invention relates to control and regulation, and more specifically to methods for programmed control of the feed rate during grinding.

There is a known method of controlling the feeding of the grinding caliper, which includes generating a control signal, npt a peri-onal current product, generating a correction signal proportional to the size of the allowance and its removal rate, summing the latter with a reference signal, comparing the control signal with the total signal and generating a signal for changing the feed when their equality is 1,

However, this method does not take into account the effects of other disturbing influences on the processing process, such as, for example, the cutting ability of the grinding wheel, change in its dimensions, temperature deformations, etc. The method takes into account only the amount of allowance, since CKt is the removal rate of allowance, mainly determined by the value of allowance for grinding

bridging. This leads to low correction accuracy.

When implementing this method, it is necessary to use storage and other complex devices for storing information about the state of the grinding process at a certain moment of the technological process in order to correct the size of the allowance for nursing. This leads to a complication of the system

10 controls grinding and reduces its reliability.

The closest in technical detail to the image is the method

15 correction of the allowance for nursing when grinding, which consists in the formation during processing of the part of the control signal proportional to the current size, the formation of measles

20 of the rectifying signal proportional to the constant time of the AIDS system, summing it with the reference signal, comparing the control signal with the sum; and forming a signal to change the feed when they are equal to 2. However, this method cannot provide high accuracy of correction, since the constant time takes into account most of the factors affecting the nursing process, but does not take into account the speed of the actual (actual) feed before nursing. The constant speMeiffl of the AIDS system is measured at the beginning of the grinding cycle, and the correction command of the feed change is carried out at the end of the cycle. Due to the fact that the grinding wheel is salted and during one cycle, there is a substantially different cutting ability that is constant. time also varies significantly, since the cutting ability of the wheel is one of the constant time components of the AIDS system. Yes, it follows that in order to form a correction signal, it is necessary to measure the time constant near the command to change the grinding mode. The complexity of the implementation, due to the need to use a memory, mortise and other complex devices for storing, storing and issuing information at a certain time on the grinding process, leads to a significant complication of the grinding control system and reduces its reliability. The purpose of the invention is to improve the accuracy of the correction. The goal is achieved by the fact that, according to the method of correcting the program, grinding is performed. in the process of processing signals proportional to the current allowance, the constant time of the AIDS system, the removal rate of the allowance, the signals proportional to the constant time of the AIDS system and the removal rate of the allowance are algebraically summed with the signal proportional to the current allowance, and the result of the sequence is compared with the specified the reference signals and, when they are equal, form commands to switch processing modes. The adjustment of the reference levels corresponding to the set values of the allowance at which the feed rate must be reduced is made on the basis of the total control signal 3v,. Else 3sf is selected at maximum values of the constant time T of the AIDS system and velocity P: .the allowance V. For this case, the switch from rough grinding to finishing is carried out when -h / is equal to the reference signal DO. Switching from finishing feed to nursing is performed when Jv / is equal to the reference signal Rear (. Grinding end 1sh is done at point O when the allowance is zero. When grinding a product with lower T and V values, the control signal is more than the previous one (, which was used to adjust the levels of E will provide a correction of the triggering times of the comparators by the magnitude of the change in T and V. Thus, when the grinding conditions change, the control signal is corrected (corrected) and the change in grinding modes The value of the delay introduced into the control signal on the scale, the allowance is proportional to the constant time of the AIDS system and the removal rate of the allowance. The drawing schematically shows a device for implementing the method.The device includes a measure 1 of the size of the workpiece 2, through the adder 3 connected to the first Bxtv of 4–6 comparators of commands, constant time meters 7 and feed rates 8 connected to adder 3. The device operates next M orazom. When supplying the grinding caliper 9 to the workpiece 2 begins with the removal of the metal. The adder 3 informs about the grinding process in the form of electrical signals: from meter 1 - signal proportional to the value of the remaining allowance from meter 7 - signal proportional to the value of the time constant of the AIDS system, from meter S - signal proportional to the speed of removal of the allowance. Moreover, the signals from the meters 7 and 8 are fed to the adder so that they are subtracted from the signal from the meter 1. The algebraic sum of the signals from the output of the adder 3 in the form of a control C11 signal 3, is fed to the first inputs of the comparators 4, 5 and 6. To the second inputs of the comparators apply constant signals, proportional to the given values of npifflycKOB, on the final grinding of the rear, nursing and size Hfi, respectively. During the grinding process, the size of the remaining allowance decreases. Reduces the control signal D-y from the adder as well. When the signal Jvy decreases to 3., the controller 4 will issue a command to the machine 10 to turn on the final feed. With a further reduction of ZU, the Comparators 5 (with Zch, 3o,) and B (with O) are triggered. The implementation of the method will significantly improve the quality of processing by increasing the correction accuracy and reliability and obtain an economic effect of more than 5OO rubles per formula Formula of the grinding program, consisting in the formation in the processing of signals proportional to the current allowance, the constant time of the AIDS system and the removal rate of the allowance, characterized in that, in order to improve the accuracy of the correction, the signal ala proportional to the time constant of the system and AIDS removal rate allowance algebraically summed with the signal proportional to the current machining allowance, and the result is compared successively with preset reference signals and when they are equal formed switching command processing modes. Sources of information taken into account in the examination 1. USSR author's certificate N9 4796G4, cl. B 24 B 49/00, 1973. .2. Author's certificate of the USSR No. 601148, cl. Q 05 19/00, 1977 (prototype).

Claims (1)

Claim A method for correcting a grinding program, which consists in generating, during processing, signals proportional to the current stock, AIDS system time constant and stock removal speed, characterized in that, in order to increase the correction accuracy 5, signals are proportional to the AIDS system time constant and stock removal speed , are algebraically summed with a signal proportional to the current stock, and the result is sequentially compared with the given reference signals and, if they are equal, generate switching commands e processing modes.