1. Machine control system
This article describes the dynamic gantry, twin-spindle, dual-axis group of CNC machine tools mainly by the machine operator panel (including the display), X1, X2, Y1, Y2, Z1, Z2 six linear coordinate axes (where X1, X2 for the gantry synchronization axis) , Double spindle and machine tool hydraulic, lubrication, cooling system and other auxiliary functions. The electrical system of the machine tool includes a numerical control system (CNC), a servo drive system, a spindle frequency conversion speed control system, and a PLC control system for input and output of the machine tool. The CNC system mainly completes man-machine dialogue operations and the control of six coordinate axes and two spindles and machine tool auxiliary devices. Due to the number of control axes of the machine and the requirements of the multi-axis group, the NUM Power 1060 system is used as the numerical control system with the best cost performance.
2. Features of NUM Power 1060 CNC System
The NUM Power 1060 is one of the world's most advanced systems. With features of strong functionality, good development and high stability. The NUM Power 1060 system can control eight axes. Four-axis linkage is the basic configuration. The graphics function in the system manages the CNC panel display and the keyboard. The memory is used to store operating programs, LC programs and user files. The powerful communication function provides three communication interfaces and RS232, RS485, and RS422 communication options. Powerful network functions reserve a network interface for users.
For this machine, it uses many powerful features of the NUM Power 1060.
2.1 Multi-axis group function
The machine has two spindles and can be cut at the same time, requiring the system to have dual axis functions. The advantage of the dual-axis group control is that the system has two relatively independent channels. Each channel has a relatively independent PLC, NC information exchange area, M code, T code, and PLC variables and flags.
The system can be switched between the common axis group mode and the independent axis group mode. When the system works in the common axis group, the two axis groups have the same working mode. When the system works in the independent axis group, the two axis groups can have different working modes and can operate independently.
The machine places X1, Y1, Z1, and X2 in axis group 1, and Y2 and Z2 in axis group 2. The two spindles of the machine tool are assigned to different axis groups. In different axis groups, the two spindles can work simultaneously or individually at their own speed and direction. In addition, the number of linkage axes given by the system can be realized in each axis group.
2.2 Longmen synchronization function
The machine tool is a moving gantry structure with a large span and must use a dual drive method. This requires that both servo motors remain synchronized. Using NUM's synchronous axis function, which uses two axis ports to drive two motors, NC's software ensures that they have the same acceleration, velocity loop, and position loop. (see picture 1)
Figure 1 system synchronization axis control method
As shown in Figure 1, X1 and X2 are synchronized axes, and the NC controls their speed loops and position loops to ensure their strict synchronization.
3. PLC of NUM Power 1060
The NUM1060 system built-in PLC uses the input/output interface provided by the NUM system to exchange data with the outside world. The data in the storage area is refreshed through the PLC scan cycle. PLC reads the outside world data through the %I variable, and the PLC output to the outside world data is through The %Q variable is performed. The data is exchanged between the built-in PLC and the NC through the exchange area. The contents in the exchange area are input/output data between the NC and the PLC.
The programming of NUM CNC system PLC program adopts ladder diagram form, which is a combination of ladder diagram language and statement statement language (that is, the statement table instructions can be directly written on the ladder diagram, without the mutual conversion between the ladder diagram and the statement table), and The structure is a multi-tasking, time-sharing approach that is particularly suitable for the preparation of more complex PLC programs. NUM provides powerful PLC instructions, and PLC programs can be dynamically displayed on the screen. Through the PLCTOOL software running under the WINDOWS environment, it is possible to transfer programs programmed on the PC to the NC and perform on-line monitoring.
Two-axis group functions involve PLC variables:
%W2.2 Switch between common axis group and independent axis group. %W17.B axis group selection. Used to display the corresponding axis group data.
%Wg03.B independent axis group work mode selection. %Wg00.5 M function response signal for axis group g.
%Wg01.2 Cycle start request for independent axis group g. %Wg01.1 Cycle stop request for independent axis group g.
%Wg02.B Feedrate override of axis group g. The %Rg1E.W axis group g requires the M function code of the reply.
%Rg7C.L Tool number of axis group g.
Synchronous axis function involves PLC variables:
%W4.4 axis synchronization signal.
4. The machine parameter settings
NUM1060 parameters can be divided into axis configuration, measurement parameter setting, servo control parameter setting, stroke setting, spindle parameter setting, auxiliary function parameter, communication parameter setting, and DISC axis parameter setting according to function. Eight other aspects. When parameters are set, it is very convenient and flexible to use these several aspects to set up. It is easy to learn and use.
Two-axis group function-related parameters:
P97 This parameter defines the number of axis groups of the CNC system. P0 This parameter defines the axis of the CNC system to be displayed.
P2 This parameter defines the measuring axis P3 of the CNC system. This parameter defines the servo axis and interpolation axis of the CNC system.
P5 This parameter defines the machine type P9 of the axis group. This parameter is used to associate the axis name with the actual address.
Synchronous axis function related parameters:
P27 This parameter assigns the slave axis and master axis. P28 This parameter is used to enable synchronization of the master and slave axes.
P24 This parameter is used to specify an axis's allowable synchronization error, correction factor, and maximum synchronization error.
5. Problems with the programming of workpieces
The multi-axis group machining program is a combination of programs corresponding to each axis group. Each program has a common basic sequence number, followed by an index number for the specified axis group. The subprograms of the machining program do not need the index number.
For example: %8.1 Axis group 1 program number % 8.2 Axis group 2 program number
In addition, there is the G78 axis group synchronization function, because the synchronization axis is placed in the 1-axis group, so the synchronization of the axis group must pay attention in the programming process.
For example: %8.1 %8.2
N10...N10...
N30...N30...
N40G78Q1N40G78P1.1 Waits for Q1 in %8.1
Waiting for Q1 N70G78Q2P1.2 N70G78Q1 in %8.2
N80... N80...
N90G78P2.1
When the flag 1 appears in program %8.1, %8.2N40 will run down. When the flag 1 appears in %8.2, N70 will run down in %8.1. %8.2N90 will run down when the flag 2 appears in %8.1.
The main functions and controls of this moving gantry and twin-axis machine tool are completed by the above aspects, and the processing in the PLC is indispensable for this machine tool. After processing the above parameters and variables, the two-axis group and gantry-synchronized machine can work normally.
