Improvement of the spindle system In the numerical control transformation of the C0630 lathe, in order to make it possible to have both the functions of CNC machining and easy teaching, and reduce the investment, the original gearbox is retained for the spindle system by the shifting handle. To complete the stepless speed regulation of the spindle, the spindle motor adopts three-phase asynchronous motor, model Y954, power is 1.1kw, equipped with corresponding electrical control equipment, can realize the positive and negative rotation of the spindle, the spindle jog, the thermal protection of the spindle motor And other functions, as shown, the forward or reverse command is written in the program through the panel operation, and the forward output relay (KAZ) or reverse relay (KAF) is controlled by the PLC output port to make the contactors KM1 and KM2 act to complete the spindle. In order to reduce the starting current of the spindle motor, three contactors KM3, KM4 and KM5 are used to complete the star-delta switching of the motor. To accommodate the threading requirements, an encoder is mounted on the spindle and the 802SNC unit is input via port X4. A set of normally open contacts of the thermal relay (FR) is connected to the PLC input point I0.7. When the motor overheats, the thermal relay (FR) acts to make I0.7 valid, the NC unit generates an alarm, and cuts off the power of the spindle motor. . Spindle encoder Although the spindle speed is controlled by the machine, the spindle speed must be known during the threading process. The feedrate is calculated according to the spindle speed. For this purpose, we have installed a spindle encoder on the spindle to detect the spindle speed. According to the processing accuracy requirements, select the spindle encoder with 1200 pulses per revolution. The encoder signal enters the 802S NC unit through port X4, and the X4 port is a 15-pin D-type socket (hole), where 1015 feet are zero phase positive and negative pulses Z and Z-, B phase positive and negative pulses B and B and A The positive and negative pulses A and A-, 4 and 6 are GND. Finally, the number of pulses per revolution of the encoder is filled into the machine data 31020 of the NC unit. The electric tool holder adopts the LD4C0625 four-station electric tool holder produced by Changzhou Hongda Machine Tool CNC Equipment Factory. It is used as the electric tool holder of C0630 lathe. When selecting the tool, input the T number (tool number) and D number of the selected tool in the program. (cut edge number), the NC unit turns on the forward rotation relay of the electric tool holder (in the tool holder controller) through Q0.4 of the PLC output port X2005, so that the tool holder rotates forward, when the selected tool reaches the machining position. The integrated Hall element on the tool holder sends a signal to inform the NC unit to end the tool selection through the I0.0I0.3 of the PLC input port X2003. The schematic diagram is as shown. The four lines of 1, 2, 3, and 4 in the 802S input and output wiring diagram are respectively connected to the four in-position signals of the electric tool post (active low level), while the PLC input of the 802S is high level (1530VDC), so use KA1. , KA2, KA3, KA4 four 24V DC relays to complete the high and low level conversion. Reference Point Establishment The machine coordinate system is the machine-specific coordinate system. It is the reference point for other coordinate systems (such as the workpiece coordinate system and the programmed coordinate system). The coordinate origin M of the C0630 lathe is set at the intersection of the chuck base and the spindle center line. As shown, the numerical control system establishes the machine coordinate system by detecting the specific position of the reference point. We use two proximity switches, mounted on the bed, one in each of the X and Z directions to establish a reference point. When moving the tool holder and both proximity switches have signal output, the current position of the tool holder is the reference point R. Measure ZR and XR and write them to machine data 34100 (reference point position value), which can be used in CNC The machine coordinate system is established in the system. (Finish) Automobile And Motorcycle Accessories Die Casting,Die Casting Machining,Die Casting Machine Stamping Part Co., Ltd. , http://www.nscnc-machining.com