SU921823A1 - Internal grinding machine control method - Google Patents

Description

(5) METHOD OF MANAGING THE INTERNAL GRINDING MACHINE

I

The invention relates to metal working and can be used. on internal grinding machines.

A known method of controlling the grinding machine to control the load on the electric motor of the grinding wheel with programmable mode switching, which means that the load on the electric motor is recorded before the grinding process begins (before the wheel is entered into the part) and is subtracted from the current load value. intermittent transfer of the 1x circle to the part, the inclusion of the accelerated feed and the switch to grinding: according to a given program, with an increase in the difference between the memorized and the current value Achen load to a predetermined level 11 program.

This method does not allow one to compensate for the effect of the additional and variable as the load circle is worn on the electric motor of the grinding wheel associated with the effect of the coolant. This leads to a significant dispersion of the parameters of the cutting process and the moment of switching from the accelerated to the working feed when processing a batch of parts, and consequently, to a decrease in the productivity and accuracy of grinding.

The purpose of the invention is to improve the accuracy and performance of grinding.

The goal is achieved by the fact that in the method of controlling the internal grinding c-tank to control the load on the grinding motor

15 wheels with a programmable switching of the grinding process modes, the grinding wheel is first jumped to the part, then the value of the load on the electric motor is remembered, the accelerated feed is switched on, and when the difference between the memorized and actual load values is reached to the programmed level, the accelerated feed is switched to grinding given program

This makes it possible to take into account the effect of an additional load on the grinding wheel motor, which changes as the wheel wears out and is associated with a change in the coolant pressure in the crescent cavity between the wheel and the part.

Fig. 1 shows the curve of the load change on the grinding wheel electric motor (e.g., the active component of the power consumed by the electric motor from the network) during the machining of one part; in fig. 2 is a functional diagram of a device implementing the proposed control method.

The proposed control method is as follows.

After the next machining cycle, the parts are overloaded, the grinding wheel is entered into the part (time intervals L ti and d t (respectively), a jump-in supply of the grinding wheel to the surface being processed (time t), accelerated approach and plunge of the wheel into the part (time intervals D t ., respectively). The time tj corresponds to the moment of contact of the part circle. During the entire processing cycle, the load on the grinding wheel electric motor is measured. During the overload of parts, the load on the electric motor Nyx is inserted and the no-load loss in the machine spindle group is met. When a wheel is introduced into a part, the load on the electric motor increases to Мr, due to the resistance exerted by the coolant flow through the hollow spindle of the workhead. The load on the electric motor is increased abruptly due to the formation in the crescent cavity between the circle and the detail of the zone of excessive pressure coolant. Immediately after the sudden approach of a circle, a load is memorized. In the process of accelerated plunging, the memorized load value is continuously subtracted from its current value, and as the resultant signal increases to a predetermined Njjji level, it switches from accelerated feed to grinding according to a predetermined program.

Thus, this control method allows you to compensate for the cumulative effect of such factors as idle loss in the machine spindle group and additional load on the grinding wheel motor due to the resistance of the coolant. This ensures a higher switching accuracy from the accelerated feed to the working one and, accordingly, higher accuracy and processing efficiency as compared with the known control method with only idle loss memorization.

The proposed control method can also be implemented at the stage

Claims (1)

fine grinding in cycles with intermediate grinding wheel grinding. Moreover, the value of the accelerated feed after straightening the wheel and the load on the grinding wheel motor at the time of switching from the accelerated feed to the final grinding can be set different from their values at the rough processing stage. A device that implements the proposed method contains machine 1 with the engine 2 grinding wheels, connected to the sensor 3 load. A memory device 4 and one of the inputs of the adder 5, the second input of which is connected to the output of the memory device k, are connected to the output of the load sensor 3. A threshold device 6 is connected to the output of the adder 5. The memory device t is also connected to the grinding jump start switch 7 the circle to the part and the command block 8 of the initial position of the control circuit 9 of the machine 1, in which these blocks are included. The command block 8 is also connected to the threshold device 6 to which the setpoint 10 is connected. 6 is connected to the machine control circuit 9. The device works as follows. Using sensor 3, the load on the engine 2 of the grinding wheel of the machine 1 is measured. The machine control circuit 9 performs programmable switching of the machine modes according to a predetermined algorithm and is a typical internal machine control circuit. With the help of block 8, the machine equipment is set to the initial state before the cycle, including the initial state of the threshold device 6 and its memory device are set. After a stepwise approach of the grinding wheel to the workpiece from block 7, the memory device k receives a command to memorize the signal of the load sensor 3. From this moment, the adder 5 receives a signal proportional to the current load value from the sensor 3 and the signal from the unit and proportional to the load on the engine 2, depending both on the idling of the engine itself, and on the additional loads on it, arising after the introduction of the grinding wheel into the part and its sudden approach to the machined over associated with the influence of coolant. The resulting signal at the output of adder B is proportional to the load that occurs on engine 2 due to cutting. When the accelerated grinding wheel feed is turned on, this resultant signal will be zero until the wheel touches the workpiece and the process begins. Switching to grinding 1- “. Threshold device 6 is carried out from a specified program with an increased difference between the stored and current load values up to a given level of 9–23 set by setting unit 10, the number of threshold devices 6 and setting unit 10 is determined by the structure of the processing cycle (for example, with cycles grinding wheel between roughing and finishing grinding can be used different settings. Claims The method of controlling the internal grinding machine consists in j that abruptly brings the grinding wheel to the workpiece and turns on the accelerated feed, and when the difference between the actual and the stored motor values of the programmed level is reached, the accelerated feed is switched to grinding according to a predetermined program, characterized in that, in order to increase the accuracy and productivity of grinding, the value of the load on the electric motor is memorized after intermittent supply of the grinding wheel to the workpiece. Sources of information taken into account in the examination 1. Kostyukov KM and Mikhelkevich 8. And, Automatic devices g1-1 v "g |" r-ia t F-icj I KiMc; iri ic ywlpuvtv ioa l reduce the auxiliary time in metalworking, Kuibyshev Book Publishing, 1973 .-.