AE signal puts in former processing law 's charge to grind the application in be being monitored dully in emery wheel

1The installation J of AE sensor.

Webster, i.

Marinescu and R.

Bennett experiment proves, the distance that sensor of AE of mechanical coupling type installs the position to be apart from grinding area exceeds 150mm to cannot detect AE signal. Take sensor of mechanical coupling means to be apart from grinding area for the gram far and cause signal pollution and lack fidelity inadequacy, we used the new-style voice that uses cooling fluid to pass information of state of emery wheel grinding as medium to launch sensor, this kind of sensor installation is on the nozzle of the lubricant cooling pipe with original machine tool, AE signal passes emery wheel tatty lubricant cooling fluid, with flowing with lubricant cooling fluid opposite way delivers sensor, undertake analytic handling through collecting card to enter the computer next. 1.

2AE signal puts in experiment of former processing law 's charge to prove, in grinding process, when treatment object and treatment parameter are changeless, the condition of the amplitude of transmit and emery wheel surface has reputation very good correspondence concerns, can the threshold value with appropriate set, change through monitoring transmit amplitude, monitor level of emery wheel passivation effectively. But, the process is machined in grinding of small lot, much breed in, parameter of treatment object, treatment often changes, condition of even if emery wheel falls in consistent circumstance, when treatment object is changed, transmit amplitude also can produce sound acuteness change, through monitoring transmit amplitude size, the method that judges extent of emery wheel passivation no longer effective. The passivation circumstance of the emery wheel in putting in former processing law 's charge to monitor process of grinding of small lot, much breed for what this article puts forward to use transmit. Its are basic the thought is to adopt different grinding requirement (the grinding object that differs namely and grinding parameter) produce the sum of transmit amplitude increment Δ T, the signal source that regards passivation of the emery wheel that monitor as degree (1) seeing a picture. Graph transmit amplitude change that condition of 1 different grinding produces T3+ of Δ of T2+ of Δ of T1+ of Δ of T= of Δ of the sum of increment of AE signal amplitude... + Δ Tn among them, Δ T1, Δ T2, ... the increment of AE signal amplitude that Δ Tn issues for different grinding condition respectively. Compare Δ T and photograph of set threshold value, if exceed threshold value, state emery wheel already was ground blunt, need nap. 2 experiments and conclusion are opposite for material of workpiece of test and verify and treatment parameter the influence of AE signal, it is OK to prove AE signal puts in former processing law 's charge further degree of passivation of emery wheel of process of treatment of grinding of pair of small lot, much breed undertakes be monitoringed effectively, we had the following test. 2.

Machine tool of 1 experiment condition: MMB140 accurate semi-automatic all-purpose cylindrical grinder: Grinding means: Infeed grinding: Emery wheel norms: GZ60ZR1A6P: Workpiece material: 45 quench steel, 2Cr13 alloy steel, HT200 casting pig: Cooling fluid: Common emulsion. 2.

2 experiments method is below the situation with other same condition, respectively grinding quenchs 45 numbers alloy steel of steel, 2Cr13 and HT200 casting pig the work with 3 kinds of simple material: In other condition same situation falls, the work with the cutting deepness same grinding that differs with 3 kinds respectively: In other condition same situation falls, the work with the same grinding of fore-and-aft feed speed that differs with 3 kinds respectively: In other condition same situation falls, the work with the same grinding of workpiece rotate speed that differs with 3 kinds respectively: In other condition same situation falls, the cooling fluid that differs with 3 kinds respectively sheds division of fast refrigeration grinding: The workpiece that norms of grinding object and grinding parameter change, treatment asks to differ 20, write down the increment of amplitude of RMS of signal of the AE when processing every work only. Increment of amplitude of signal of 3 AE of graph of influencing factor of signal of graph 2 AE changes 2.

Result of test of before 3 tests result 5 kinds of program sees a picture 2. See not hard, workpiece material change is the most apparent to influence of AE signal amplitude. In other condition same situation falls, the amplitude of AE signal RMS of the generation when workpiece of grinding HT200 casting pig is the smallest for 1100mV, take second place of 2Cr13 alloy steel is 1600mV, 45 quench steel most greatly 1700mV. Other.

Kind the element is weaker to the influence of amplitude of AE signal RMS, but the effect that has different rate, cannot oversight. The 6 results that reach see plan graph 3. Can see in the graph, no matter machine material or grinding parameter to produce change, the amplitude increment of transmit has reputation different level land increases. Because firm nap emery wheel is apparently certain,the occurrence of negative worth is when arenaceous bead suffers nap pound and have loss, the amplitude of AE signal RMS that grinding begins phase is bigger, reduce gradually later. 3 conclusion by test result knowable, when workpiece of grinding small lot, much breed and grinding parameter change, the method that uses variation of size of amplitude of RMS of signal of the AE that monitor does not suit to monitor emery wheel passivation, and use increment of amplitude of RMS of signal of the AE that monitor put in former processing law 's charge to suit to monitor emery wheel to grind blunt degree quite. CNC Milling CNC Machining