What Is a Cutting Machine Tool?

Wire cutting electrical discharge machine (WEDM for short) belongs to the category of electrical processing. The wire cutting machine was also invented in the former Soviet Union in 1960. Its basic physical principle is that free cations and electrons accumulate in the field and soon form an ionized ion. Conductive channel.

At this stage, a current is formed between the two plates. Resulting in numerous collisions between particles, forming a plasma zone, and quickly rising to a high temperature of 8000 to 12,000 degrees, some materials are instantly melted on the surfaces of the two conductors, and at the same time, a gas bubble is formed due to the vaporization of the electrodes and the dielectric fluid. And its pressure regularly rises until very high. Then the current was interrupted, and the temperature suddenly dropped, causing the bubble to explode inward. The generated power ejected the molten material out of the crater, and then the corroded material re-condensed into small spheres in the dielectric fluid and was discharged by the dielectric fluid. Then through NC control monitoring and control, the servo mechanism executes to make this discharge phenomenon uniform, so that the workpiece is processed, making it a product that meets the required dimensional accuracy and shape accuracy.

Control system From the late 1960s to the mid 1970s, China s high-speed wire-cutting machine tool CNC machine special industrial computer used transistor discrete components to form the gate circuit, and the gate circuit composed of registers, input controllers, arithmetic units, and output control The processing program is manually input through a toggle switch, or read from a perforated paper tape through a photoelectric reader. The glow digital tube and neon light are used to display the count length and X and Y coordinate values (binary). In the late 1970s, CNC systems have transitioned to circuits based on medium and large-scale integrated circuit chips. Although the basic principle and structure have not changed, the functions have been strengthened and the reliability has been improved. Its input still has two types of manual input (toggle or key) and paper tape input (telegraph head). The instructions are in the form of fluorescent digital tube and light-emitting diode. These products were in use until the end of the 1980s. With the emergence of single-board microcomputers (computers with CPU, RAM, ROM, and input / output interfaces mounted on a printed circuit board, referred to as single-board machines), the high-speed wire-cutting machine controller is widely used. Microprocessor-based single-board computers have truly achieved the goals of strong functions and price. For the simple numerical control system, this is a glorious period. With the development and promotion of other related industries, the numerical control high-speed electric discharge wire cutting machine has been rapidly popularized.

By the 1990s, the controllers of the numerical control system based on 8051 series single-chip microcomputers had functions such as graphic scaling, backlash compensation, short-circuit rollback, wire break protection, power failure memory, automatic centering, and automatic shutdown after processing. Features. The all-in-one programming and control integrated machine with display has also begun to be used, but the programmed programs cannot be directly transmitted to other consoles, but there are external equipment equipped with printers, paper punchers, etc., and they can only control a single machine. With the rapid development and popularization of computers, the use of desktop microcomputers (including industrial computers) can control several machine tools that work independently. Within the allowable number range, adding a machine requires only adding a control card. The working status of each machine tool can be monitored separately by switching screens. This not only saves the cost of the control system, but also takes advantage of the computer's powerful data access capabilities. The functions of the automatic programming system are constantly enhanced, and the programming methods are also diverse. There are instruction input, drawing method, scanning method, CAD file conversion, etc., and data can be exchanged through interfaces and communication such as U disk and network. Avoid manual input procedures, drawing inefficiencies and errors.

The development of fast-moving wire-cutting technology has become clearer. On the basis of maintaining the advantages of reciprocating wire-cutting, we continue to explore and research, and apply new theories and methods to new systems. The new generation control system will be more stable, more practical, simpler and more convenient.

NC wire cutting machine is composed of three parts: mechanical, electrical and working fluid systems.

(1) Wire cutting-short for CNC EDM wire cutting.

(2) Working principle: The moving metal wire is used as a tool electrode, and a pulse current is passed between the metal wire and the workpiece, and the workpiece is cut by the corrosion effect of pulse discharge.

(3) Because it uses wire electrodes, it can only be used for contour cutting.

(4) The working principle is shown in Figure 2.

Features of SAJ wire cutting machine special inverter:

Low-frequency torque output 180%, good low-frequency running characteristics

The output frequency is up to 600Hz, which can control high-speed motors

Comprehensive detection and protection function (over-voltage, under-voltage, overload) Instant restart after power failure

Protection functions such as acceleration, deceleration, and stall prevention during rotation

Automatic identification of motor dynamic parameters to ensure system stability and accuracy

Quick response during high-speed shutdown

Rich and flexible input and output interfaces and control methods, strong versatility

Using SMT full placement production and three anti-paint treatment process, the product has high stability

The entire series uses the latest Siemens IGBT power devices to ensure high quality

1. Check the switch knob of the circuit system and turn it on

1. The operator must be familiar with the performance and structure of the machine tool, master the operating procedures, and strictly abide by the safety rules and operation and maintenance procedures.

2. Non-designated personnel shall not use equipment casually, and there are safety fire prevention measures in the room.

3. The following tasks should be done before starting the machine:

1) Check whether all parts of the machine tool are intact and adjust the level regularly. Fill up the lubricating oil and fill the working fluid tank with saponified oil and water according to the lubrication regulations, keep it clean, and check whether the pipe joints are firm.

2) Check whether the connection between the machine tool and the control box is well connected, whether the input signal is consistent with the moving direction of the carriage, and adjust the high-frequency pulse power.

3) Check whether the vertical and horizontal stroke of the table is flexible, and whether the reciprocating movement of the ball cylinder carriage is flexible. The travel switch stop should be adjusted within the required range, so as not to cause the thread take-off plate to pull out when the machine is turned on. The motor must be turned off when the roller moves to the middle position. Always close. In order to avoid the inertia effect, the roller carriage is moved to break the molybdenum wire, and even the screw nut is unthreaded. Only after the above checks are correct, can the machine be turned on.

4) Install the workpiece. Place the workpiece to be cut on the mounting table and fix it with pressure plate screws. When cutting the entire cavity, the workpiece and the mounting table must not touch the wire frame. If the die is cut, the molybdenum wire should be passed through the workpiece. The reserved holes on the top can be cut only after being aligned.

5) When cutting the workpiece, first start the thread rolling cylinder and press the wire feed button. After the guide wheel rotates, start the working fluid motor and open the working fluid valve. If the machine is stopped during cutting or the machine is stopped after processing, the frequency converter must be turned off, the high-frequency power supply must be turned off, and then the working fluid pump must be turned off. After the working fluid on the guide wheel is thrown off, the roller motor must be turned off.

6) The working fluid should be kept clean and the pipelines unblocked. In order to reduce the electric corrosion in the working fluid, foam plastics can be placed in the workbench, backwater tank and working fluid tank for filtering, and the working fluid tank and filter should be cleaned regularly. Replace working fluid.

7) Keep the workbench carriage, ball screw and rolling guides clean at all times. Do not allow dust to enter, so as not to affect the accuracy of movement.

8) If the roller is shaken or vibrated during the commutation, stop using it immediately, check whether the relevant parts are loose, and adjust in time.

9) 1-2 times per week should be injected into the guide roller bearings with kerosene to maintain cleanliness and service life.

10) Pay special attention to the careful maintenance of the console device and keep it clean.

11) The operator must not disturb the electrical components and console devices. If any problems are found, the operator should immediately stop the machine and notify the maintenance personnel for maintenance.

12) When the work is finished or after work, cut off the power supply, wipe the machine tool and all the controls, and keep it tidy. It is best to cover the computer with a cover and clean the work site (to avoid dust flying), especially the sliding surface of the guide rail of the machine tool. , And refueling carefully to do a good job of handover and operation records.

1. The operator must be familiar with the operation technology of the wire bed. Before starting the machine, lubricate the relevant parts of the machine according to the equipment lubrication requirements (the lubricant must meet the requirements of the machine manual).

2. The operator must be familiar with the wire cutting process, properly select the processing parameters, and operate according to the ingot operation sequence to prevent failures such as broken wires.

3. After the handle is used as the silk storage cylinder, it should be pulled out in time to prevent it from hurting people when the storage cylinder is rotated. When handling the electrode wire, take care to prevent the electrode wire from getting stuck. The replaced waste wire should be placed in the window of the ingot to prevent accidents such as short circuit, electric shock and wire breakage caused by mixing into the circuit and wire walking system. Pay attention to prevent the broken wire and the transmission parts from colliding due to the inertia of the spool. For this reason, when stopping the machine, press the stop button as soon as possible after the storage drum has been reversed.

4. Before formally processing the workpiece, you should confirm that the workpiece position is installed correctly to prevent collision of the wire frame and damage to the screw, nut and other transmission components due to overtravel.

5. Try to eliminate the residual stress of the workpiece to prevent the workpiece from exploding and hurting during the cutting process. The protective cover should be installed before processing.

6. Do not place flammable and explosive items near the machine tool to prevent accidents caused by sparks caused by insufficient supply of working fluid.

7. When servicing machine tools, machine tool components, pulse power, and control systems, care should be taken to properly cut off the power to prevent electric shock and damage to circuit components.

8. Regularly check whether the protective grounding of the machine tool is reliable, pay attention to whether each part is leaking, and use an electric switch as much as possible. Close the processing power hand, do not touch the two output terminals (bed and workpiece) of the pulse at the same time with your hand or a conductive tool to prevent electric shock.

9. It is forbidden to press the switch with wet hands or touch the electrical parts. Prevent conductive materials such as working fluid from entering the electrical parts. In the event of an electrical short circuit, cut off the power first and immediately use a suitable fire extinguisher such as carbon tetrachloride to extinguish the fire. Do not use water to extinguish the fire.

10. When stopping, stop the high-frequency pulse power first, then stop the working fluid, let the electrode run for a period of time, and wait for the wire storage cylinder to reverse before stopping the wire feeding. After the work is completed, turn off the main power, clean the workbench and fixture, and lubricate the machine tool ^[3] .