Among the three schemes, scheme 1 has the most accurate positioning and counting, but the cost is the highest; while scheme 2 is the second, the cost is second; method 3 is the worst, but the cost is the lowest. Since the positioning requirements for the tool magazine are not particularly high in the CNC machining center, it is generally the case with the plan 3, and even so, the cost is thousands of dollars. At present, all enterprises are tapping into potential, reducing costs and increasing efficiency. In the meantime, we made some useful attempts to solve the problem of toolbox counting in the machining center. Here is a simple, effective, reliable and economical way to solve the problem of tool magazine positioning and counting.
1 proximity switch installation indication 11 these two signal level changes to periodic; 21 signal change period has an integer multiple relationship with the tool rotation of the tool magazine, ie Tm = nTs; in the n = 2. Based on this, according to When the magazine is actually running, observe and calculate the value of n, which is definitely an integer (when designing the tool magazine, select the gear with the correct number of teeth). We also see the change of the proximity switch signal. It is necessary to see that there are two signals in each signal change period Ts at the same time, so we can do two points: 11 by observing and monitoring the number of change cycles of the two signals. , that is, the number m of Ts, calculate the number of bits NT of the tool magazine rotated, that is: NT=mn; 21 because the tool magazine generally has two speeds in normal use: one normal running speed, the other is coming at the end Low speed at the target location. It is easy to use both signals in each Ts to be 1 at the same time, which makes it easy to change the tool magazine from low speed to stop. Therefore, it can be concluded that the counting and positioning of the tool magazine can be realized by two simple non-contact switches, and it is very reliable. In terms of cost, the price has dropped by an order of magnitude, and two non-contact switches, that is, the use of foreign imports are only a few hundred dollars. So it is a very economical solution.
The XH756 horizontal machining center of our factory uses a chain cutter with a modular design of 60 knives. The n= of the tool magazine, namely Ts=Tm, the tool change every cycle, the signal changes one cycle. Thus, NT=m.
In the past, the absolute position encoder method was adopted. The encoder was imported from Japan and the price was around 3,000 yuan. After our improved design, if the domestic proximity switch was used, the cost was only less than 300 yuan. Later, we improved Reliability, replaced by the German company Balluf (BALLUFF), the cost has only increased by less than double, the economic benefits are very obvious. From the aspect of error, we calculate the number of revolutions by calculating the number of pulses emitted by the absolute encoder, and calculate the number of revolutions by calculating the number of cycles from which the proximity switch signal changes from 0 to 1. In fact, there is no difference. The error of using this method is indeed larger, but for the tool magazine, such positioning accuracy is sufficient, and later we have adopted mechanical positioning pins to ensure the reliability and accuracy of use. Moreover, after adopting the method of the proximity switch, when the tool position of the tool magazine is adjusted, that is, the respective tool positions are simultaneously translated, it is particularly convenient and the maintenance is relatively easy. At the beginning, according to the principle, a proximity switch is used, but considering the precise positioning of the tool magazine and the cooperation with the rotation direction, two proximity switches are used. When processing in the PLC, reference: C1, C2 are two switching signals, R1, R2 are intermediate addresses. When the direction of rotation is reversed, C1 and C2 are exchanged. In addition, the other two conditions can be added. In practical applications, it is only necessary to use the R1 pulse as the counting condition of the magazine counter.
It can be seen that the technical innovation and technical transformation of CNC machine tools, in order to receive good results, not only the use of new technologies, new processes, but also the creative application of the existing technology.
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Carbon Steel Fuel Tank Transport Semi Trailer
Carbon Steel Fuel Tank Semi Trailer
Guangzhou Maowo Machinery Technology Co., Ltd , https://www.maowogroup.com