Chen Xingwu, Gao Zengfa 2 (1. China Aviation Technology In and Out â–¡ Fujian Company, Fuzhou 350001, China; 2. Fuzhou University, Fujian, Fuzhou 350002) Combined with AC servo motor, the manual tool grinder can be modified to realize four-axis computer numerical control linkage Processing a variety of complex tools. A simple and practical programming method allows complex tools to be ground on a modified CNC grinding machine. Only a small amount of cost is invested. Achieve high processing accuracy and production efficiency. The processing of milling cutters in China is mainly carried out on hand tool grinders. The CNC machine tool grinding machine with high price is high, and it is mainly used for the processing of complex milling cutters with less precision requirements. In this paper, the Pentium microcomputer and P80C51 single-chip microcomputer are used to carry out numerical control transformation on the domestic MQ6025A manual tool grinding machine: through hardware development and software design, it can be used for four-axis linkage and can be used for batch M-axis machining of tools. 1 Reconstruction scheme 1.1 The MQ6025A manual tool grinder structure is as follows: 4mm/rev, and the synchronous transmission belt with the transmission ratio of 4:5 is selected. Then the pulse equivalent of the X, Y and Z linear movement coordinates realized is: X, Y, Z axis : 1 worm worm gear pair and 1: 2 synchronous tooth belt, then the pulse equivalent of A slewing sleeve is: A-axis pulse 2 mechanical mechanism design 2.1 rail modification 2-1-1 vertical axis X guide rail modification. The rail structure before and after the transformation is as follows. However, it is easy to flutter, the motion accuracy is poor, and the carrying capacity is small. Now remove the V? plane guide, remove the overlapping parts of the pads m, iv and the upper slide, load the blocks I, I, n, iv. Then install the rolling guide pair HJG? D25 on the corresponding block . After this modification, the entire longitudinal rail is raised upward by about 50 mm. The remaining dimensions remain unchanged. 2.1.2 Transformation of the horizontal axis Z. The method is the same as the modification of the longitudinal uranium X, except that the height of the spacer used is smaller, and the position of the entire cross slide is not raised. The rest will not be repeated. 2.1.3 Vertical axis Y. The vertical axis Y is a circular guide structure and is not modified. 2.2 Modification of the transmission mechanism 2.2.1 Modification of the transmission mechanism of the longitudinal axis X. The transmission of the longitudinal axis X is originally a gear rack sub-structure, and the rack and pinion and its spacer are now removed. 5 kW, as shown, ie, the modified bearings A, B, C, cut off the overlapping parts, and then install the ball wire at the end of the ball screw to install the synchronous gear 1, 2. Synchronous toothed belt and AC servo motor MANA2. 5kW, as shown, The drive of the longitudinal axis X can be achieved. 2.2.2 Transformation of the transmission mechanism of the horizontal axis Z. The horizontal axis Z is originally a sliding screw drive structure. Just use the ball screw of the same size in the original position instead. The method of installing the timing belt drive pair and the stepping motor is the same as that of the vertical axis. 2.2.3 Retrofit of the transmission mechanism of the vertical shaft Y. The transmission mechanism of the vertical circular guide on the MQ6025A grinding machine is as shown. A 'anti-wheel is passed through a pair of gears to drive a pair of worm gears to the IJ, and then the ball screw is driven to move the circular guide up and down. Install an overrunning clutch on the ball screw to raise the grinding head. The flat bearing on the overrunning clutch rolls for rolling friction to reduce the resistance. When the grinding head descends, the flat bearing loses its function, and the plane slide friction is used to open and close the zero switch of the shaft. For step control. By judging the state combination of 丨, different step control can be issued. I. Used for debugging or trial grinding. The driving force is balanced when the rise and fall are reached. Now use high-precision ball screw to replace the original precision screw with poor precision, retain the overrunning clutch structure, remove the gear, worm and worm gear and other transmission mechanism, replace it with synchronous gear belt drive, and then install AC servo motor drive. . The motor output shaft has a brake, which can hold the motor shaft when the stepper motor is powered off, so as to prevent the grinding head from falling off due to its own weight. 2.3 Adding the computer numerical control rotary axis A A computer numerical control rotary table FK15110 is installed at the zero position of the left end of the workbench to calibrate the parallelism between the rotary axis A and the vertical and horizontal directions. The turret is a worm gear pair that directly drives the displacement pitch of the AC servo motor, and the clamping seat of the standard workpiece chuck is driven to realize the gapless rotation. The indexing accuracy is up to 60", and the repeatability is 7.5", which meets the needs of the work. The turret can be connected with 46 bar of compressed air to complete the clamping and disengaging of the workpiece chuck, which facilitates the clamping of the workpiece. 3 The development of computer numerical control device detects and controls the input and output of various signals during processing through the extended I/O port. Now I'm using the 8243 I/O chip, and the I/O port of the expansion host is as shown. Port, it can be programmed to operate as an input port or an output port. After reading, it is in a high-impedance state; after writing, it can be latched out with low resistance. And the data on the port can be logically ANDed, ORed with the internal accumulator, and the result is stored on the corresponding port. Each I/O line of the 8243 chip can be set as an input or output signal line for receiving or transmitting control signals. For the zero position signal of each axis, by judging its high and low state, it can be determined that the 4 system function is to ensure the modified CNC grinding machine, which can adapt to the grinding process of common milling cutters. The three working states are designed as follows: stop state. Press the stop button to input program data, modify parameters, etc. to the microcontroller. The CPU can perform calculations and processing operations. Manual status. Press the light manual button to manually control the four-axis motion and complete the manual grinding process. Pre-adjustment, tool setting, and grinding can also be performed. Automatic machining status. Press the auto-machining button, the CPU runs the machining program, controls the four-axis linkage according to the calculated trajectory, and completes the grinding process. During the machining process, you can press the pause button to pause the machining. After completing the necessary auxiliary operations, press the pause button again to continue the machining. 5 software design 5.1 system programming According to the three working states of the machine tool, the main program design is shown in the block diagram. Each time the computer performs a function, any function is returned to the main program after execution. The main program mainly includes initialization settings, display and key analysis. Initialization mainly sets the initial working state of the microcontroller, the working mode of the I/O, etc., and sets the address, parameters, and motor motion parameters. The display section is used for observation operations. The key analysis program is used to determine whether there is a key press. If the row value of the key is found, the code of the key is used to find the key, and then the entry value of the key is obtained according to the code value, so that the main program transfers to the address and executes. The key function. The programming of the machining program is described below. Before processing, it must be programmed in the host 5.2 application in this system, the application is the tool program of the tool. To grind tools of different shapes, the corresponding tool program must be programmed. Now take the cylindrical end mill as an example. The programming is as follows: Cylindrical end mills mainly include cylindrical and end face, such as Lf'": 0 executes the part program of the tool and inputs the tool parameters. The host runs a program that counts the points of the tool and stores them in memory. During processing, the computer takes the next point from the starting point in order, finds the coordinate increment, and uses the four-axis linkage with the linear interpolation to run the transition trajectory of the two adjacent points. After running a little. Then perform the interpolation of the next point until all the points are completed. See the processing block diagram. In the grinding process, each blade requires a different grinding wheel to be ground in different processes. When the part program is programmed, several specific operations can be subdivided. Each operation uses a grinding wheel to complete the grinding process of one process until all the operations are run and all the edges are ground. These operations can be run continuously or independently. The main introduction to the grinding process of the front blade surface of the cylindrical end mill is as follows, and the remaining blade faces are programmed in the same way. Firstly, the grinding path of the front blade surface is drawn as follows: 1. The linkage start I I coordinates the coordinates from the menu program 丨 71, F2 value, set I;: point 1 å¿: (FI, 0, 0, F2) And set the fast motion state to read the 丨1 and L values, calculate 360°*F8/L, set the point b coordinate to read the F9 value, set the point 7 coordinates, and set the fast motion. 6 read the octagonal number 10 value, calculate the 360V value, set the five points and 9 coordinates over 1, 2 points, run to the tool point 3, the distance of each coordinate axis running FI, F2, F3, F4 parameters are input by the operator when setting the knife . Then, the rapid feed of the Y-axis (F5) and the A-axis (F6) is performed to 4 o'clock, and then the rapid traverse F7 of the Y-axis is performed to reach the starting machining point 5. The X-axis and the A-axis are started from 5 o'clock. Linkage, grinding the front blade surface in the direction of the tool helix, grinding length (x = F8). Then the Y-axis quickly retreats from F9, and then the X and A axes are also quickly retracted to 8 o'clock. The A axis is equally divided according to the number of teeth 10, the Y axis feeds a F9 to the grinding start point of the second tooth 10, 10 points coincide with 5 points, and the path of 5 to 10 points is cycled until all the front faces are Grind it out. Then determine if a rough or fine grinding cycle is required until the end. Then judge whether to carry out the grinding of the next operation step. If necessary, the Z axis retreats from F10 to 11 o'clock, and retracts the space to transfer to the next process of grinding; if the processing is completed, the warp point starts from 10 o'clock. 11, 12, 3 returned, to 14 o'clock each axis returned to the machine tool zero or more parameters involved in the uranium movement: Fl, F2, ..., F10, and 10, 12, L, etc., unified into a menu form, The operator inputs one by one before the addition, and the tool part program uses these parameters to calculate the coordinate values ​​converted into points. Stored in computer memory. When the grinding process is started, the machining program is started, and the computer takes out the coordinate values ​​point by point, performs the interpolation motion, and completes the grinding process. OP.1 tool value or set value: the corresponding part program is as follows. 2. The tool part program is combined with the menu program. For each operation, you need to input the menu program first, then run the tool part program. Once the computer has completed the calculation, the grinding process can be started. The above describes the programming method of the front edge grinding of the cylindrical end mill. The programming methods of other blade faces are similar and will not be described. 6 Conclusions Through the structural analysis of the MQ6025A manual tool grinder, combined with the current domestic application of microcomputer and single-chip microcomputer, it is summarized as follows: Four-axis linkage computer numerical control transformation of MQ6025 manual tool grinder can not only meet the general needs of tool processing. And can improve processing accuracy, reduce labor intensity, and improve street efficiency. Developed by port as the control of this system. It can meet the needs of work, and simplifies the control structure. The system works reliably and the scheme is feasible, which can greatly improve the performance/price ratio of the tool grinder. (Finish) Cup Mask Making Machine,High Quality Cup Mask Making Machine,Cup Mask Making Machine Details, CN KYD Automatic Mask Machine Factory , https://www.kydultrasonic.com