First, the input device
The function of the input device is to transfer and store the numerical control code on the program carrier (information carrier) into the numerical control system. Depending on the control of the storage medium, the input device may be an optical reader, a tape drive, or a floppy disk drive. CNC machining programs can also be directly input to the CNC system through the keyboard. The NC machining program can also be transmitted to the CNC system by programming computer using RS232C or using network communication.
There are two different methods for the input process of the part machining program: one is the edge-reading edge machining (the memory of the numerical control system is small), and the other is the one-time reading of the part machining program into the internal memory of the numerical control device, and then processing The internal memory is called up piece by piece and processed.
Second, numerical control device
The numerical control device is the core of the numerical control machine tool. The numerical control device takes out or accepts the one or several sections of numerical control machining programs sent from the internal memory by the input device, and after compiling, calculating and logically processing the logic circuit or system software of the numerical control device, it outputs various control information and instructions to control the machine tool. The work of each part enables it to carry out the prescribed orderly movements and actions.
The contour figure of a part is often composed of a straight line, an arc, or other non-circular arc curve. In the machining process, the tool must move according to the shape and size of the part, that is, move according to the figure track. However, the input part machining program can only be the data of the starting point and end point coordinate values of each line segment trajectory, and cannot meet the requirements. Therefore, the trajectory interpolation is performed, that is, the data points are encrypted between the starting point and end point coordinate values of the line segment. "Changing", the coordinates of a series of intermediate points are obtained, and the pulse signals are output to the corresponding coordinates to control the feed speed, feed direction and feed displacement of each coordinate axis (ie, the actuators of the feed motion).
Third, the drive device and position detection device
The drive device receives the instruction information from the numerical control device. After the power is amplified, the machine tool moving component is driven in strict accordance with the requirements of the instruction information to process the component that meets the requirement of the pattern. Therefore, its servo precision and dynamic response performance are one of the important factors affecting the machining accuracy, surface quality and productivity of CNC machine tools. The driving device includes two parts, a controller (including a power amplifier) and an actuator. Most of the current use of DC or AC servo motor as the actuator.
The position detection device detects the actual displacement of each coordinate axis of the numerical control machine tool, and after the feedback system is input to the numerical control device of the machine tool, the numerical control device compares the actual displacement value feedbacked with the set value, and controls the drive device according to the instruction. Fixed-value sports.
Fourth, auxiliary control device
The main function of the auxiliary control device is to receive the switch quantity command signal output by the numerical control device, and after compiling, logically identifying and moving, and then drive the corresponding electric device after the power amplification, to drive the mechanical, hydraulic, pneumatic and other auxiliary devices of the machine tool to complete the instructions. Switching action. These controls include the shifting, commutation and start-stop commands of the moving parts of the spindle, the selection and exchange of the tool instructions, the start and stop of the cooling and lubricating devices, the loosening and clamping of workpieces and machine components, and the indexing table indexing. Other switch assisted actions.
Because programmable logic controllers (PLCs) have the characteristics of fast response, reliable performance, ease of use, programming and modification of programs, and direct start-up of machine switches, they are now widely used as auxiliary control devices for CNC machine tools.
Fifth, the machine body
The machine body of a CNC machine tool is similar to a traditional machine tool and consists of a spindle transmission device, a feed transmission device, a bed, a work table, an auxiliary movement device, a hydraulic pneumatic system, a lubrication system, and a cooling device. However, great changes have taken place in the overall layout, appearance design, transmission system, tool system structure, and operating mechanism of CNC machine tools. The purpose of this change is to meet the requirements of CNC machine tools and give full play to the characteristics of CNC machine tools.
First, disassembly and assembly tools
1. Single-head hook-type wrench: It is divided into fixed type and adjustable type. It can be used to pull a round nut with a straight slot or hole in the circumferential direction.
2. Circular nut wrenches with slots or holes on the face: They can be classified into socket wrenches and double-pin fork wrenches.
3, the elastic ring assembly and disassembly pliers: divided into the shaft with the elastic ring assembly and disassembly pliers and holes with elastic ring assembly and disassembly pliers.
4, elastic hand hammer: can be divided into wooden hammer and copper hammer.
5, pull taper flat key tools: can be divided into impact pull taper flat key tools and pull pull taper flat key tools.
6, pull tape with small shaft, taper pin tool (commonly known as dialing device).
7, pull off the tool: disassembled on the shaft of the rolling bearings, pulleys and other parts of the coupling, commonly used pull unloading tools, pull unloading tools are often divided into two types of screw and hydraulic, screw pull unloading tools in two claws , three-jaw and hinged.
8. Pull the open-end pin wrench and pin punch.
Second, commonly used mechanical repair tools
1, feet: divided into flat feet, knife ruler and 90 degree square.
2. Horns: horns with a surface of 90°, horns with an angle of 55° and level horns.
3, test rods: There are standard taper shank test bars, cylindrical test bars and special test bars.
4. Lever Micrometer: When the geometric precision of the part is required to be high, the use of a lever micrometer can meet its measurement requirements, and its measurement accuracy can reach 0.001mm.
5, Universal Angle Ruler: Measuring tool used to measure the angle between the inside and outside of the workpiece, according to the vernier reading value can be divided into 2 'and 5' two, according to the shape of its ruler can be divided into two kinds of round and fan-shaped.
