Wire Cutting Machine Frequently Asked Questions 39 Cases

1. How is the linearity of X and Y movements guaranteed?

First, it should be clear that the straightness of an axis refers to its straightness in two planes. For example, the straightness of the X-axis refers to the straightness in the X, Y plane and the X, Z plane. This is like a road—that is, it must not bend up or down without bending.

The pallet of the machine tool is carried on the guide rail, so the straightness of the guide rail determines the straightness of the movement. There are two reasons for the loss of straightness. One is the straightness of the rail itself, and the other is the straightness of the rail mounting reference plane. The high accuracy and stable state of the guide rails, the combination of the pallet and the bed are the basic conditions for guaranteeing the straightness. This is also the purpose of the high and low temperature and aging treatment of rails, pallets and beds.

The inconsistency of the roller (steel ball) will lead to less stress points or seesaw phenomenon is also obvious.

It should be noted that the non-standard movement of the screw may also affect the guide rail. For example, the axial direction of the screw is not parallel to the guide rail, the center height of the screw and the nut is inconsistent, and the screw and the nut bear a twisting force and the wire The bending of the bar, etc., will both push the hard bar and interfere with the linear motion of the guide rail while moving. This is what we emphasize to make the screw, the nut, the screw seat and the screw base all accurate. The basic reason for the specification.

Whether it is a "V" shape or a "1" shape, the guide rail and the raceway must not be contaminated with any contaminants. It will not only affect the straightness of the guide rail but also cause damage and deformation of the guide rail. The guide rail requirements are spotless. This is one of the rules for maintaining and maintaining machine tools and maintaining long-term accuracy.

Second, how is X and Y movement verticality guaranteed?

The perpendicularity of the two axes is based on the respective straightness. The error of the straight line will be reflected in the measurement of the verticality. The result of the numerical superposition makes the measurement of the verticality inaccurate. Therefore, the straightness of the two axes is guaranteed firstly. Guarantee the perpendicularity of each other.

The verticality of the two axes is completely determined by the verticality of the two sets of guide rails on the middle bracket. When assembling, the set of guide rails is fixed on the reference, and the other guide rails are perpendicular to the reference after measurement and adjustment, and then fixed and matched. The nail holes are driven so that the verticality of the two sets of rails on the middle pallet is fixed. This assembly and measurement process, that is, the pursuit of safe and effective operation, should also intentionally increase the precision by one step. The control of this intermediate process index is very important, because whether it is installed, repaired, or effected for some time, this accuracy will be achieved. Worse, if the initial installation to use the allowable error value, then the accuracy of the value will be inaccurate. For example, if the accuracy standard of a machine tool is 0.02, the accuracy of internal control at the first assembly should be less than 0.012. The strict control of the first part of the important part and the pin and nail are secure and effective. In addition, the guide rail itself is straight and accurate, and the verticality of the two axes is guaranteed.

Like the straightness, the working state of the screw is also an important factor that affects the verticality. Any external force that forms a certain angle with the positioning surface of the guide rail will cause the guide rail to change, because the guide rail is only the guide rail and does not pinch. Therefore, once the verticality of the X-axis and Y-axis is found to exceed the standard, it must be carefully judged whether it is caused by the deformation or misalignment of the guide rail or the movement of the screw. If it is due to the guiding action of the guide rail, the screw and the nut are repeatedly loosened and refastened in several positions. The direction and the value of the excessive standard should be generally stable. If it is caused by the interference of the screw and the nut, it will lose the direction and value, and even cause the molybdenum wire to be grooved. Therefore, a simple taper machine formed by a taper device is generally installed on a linear machine, and the maximum cutting taper is generally limited to ±60. This taper value is more than sufficient for the completion of some drafting tasks. Larger taper cutting depends on special taper machine tools, which must solve the problem of guide roller and UV runaway. There is no interference effect of the guide pulley groove after the yaw, and the taper of the cutting is theoretically accurate. Associated negative effects are that the overall stiffness is reduced in order to solve the yaw follow-up problem, the motion delay and hysteresis are highlighted, and the accuracy of sports fidelity is also greatly reduced. In daily use, the versatility, stability and convenience of linear cutting are also affected.

XI. Analysis and Resolution of Wire Cutting "Flowers"

After cutting for a period of time, the molybdenum wire will have a period of dark spots. The dark spots are usually several to ten millimeters long, and the intervals of the black spots are usually several to several tens of centimeters. Dark spots are continuous arc discharges over a period of time, burns and carbonization. Fine and brittle and easily broken after carbonization. Black spots form a black spot on the package, and sometimes they are arranged in a regular pattern to form a pattern. It is called "filament."

XII. Causes of the "flower filament" phenomenon

Due to the inability to effectively deionize and cause continuous arc discharge, the resistive heat of the arc precipitates a large amount of carbon to form carbon fine particles, and the molybdenum wire itself is also carbonized. Thickness of the workpiece (long discharge gap), low dielectric coefficient of water (poor recovery of insulation capacity), and one of the three sources of the pulsed source with a delayed arc-extinguishing DC component (greater than 10 mA) are the basic conditions for the “flower filament” phenomenon. . The “impurities” brought into the discharge gap (or inherent in the workpiece) that affect the spark discharge are the cause of the “filament” phenomenon. "Filigree" is the same as the arc burn of spark discharge machining. Once the arc burn in the gap is formed, the workpiece and the electrode will be burned out of the pit and formed into charcoal particles. If the carbon fine particles are not cleaned, they cannot continue. Processing. Fine carbon pellets stick there, where arc burns will take place, and the area will become larger and larger, and there is absolutely no possibility of self-elimination. If the workpiece and the electrode are displaced, each new and the opposite arc will cause a new burn in the arc, one in two locations. The only way is for people to clean up, and the line cut is powerless.

XIII. The occurrence and development of "flower filaments"

When the discharge gap is long, discharge of the erosion material is difficult, the ability to recover the insulation is poor, and the spark explosion is weak, “impurities” are easily generated, the resistance heat rapidly becomes arc burn, and the carbon fine particles are mixed together. During the movement of the wire, each pulse of energy is released through this point of arcing until the point of arcing is removed from the workpiece. Insulation can recover and new spark discharges may occur. Molybdenum wire burns at this point (ie dark spots) are formed. If the point where the arc burn just induced in the gap is still tenacious, it is very easy to repeat the arc discharge with the molybdenum wire that is in contact with it, and the second burned carbonized (ie, black spot) spot is formed again. So the distance between that point and the workpiece exit is often equal to the distance between the two dark spots. After the first burn was carbonized, a carbonization point was left on the wire, and a series of charring spots were left in the workpiece gap. Fine carbon particles spread into the water and entered the gap at any time. They all became the inducement of “filigree”. factor. It became a "cross-infection". At this time, no matter which silk, water, or work piece was changed, it would be useless to change everything. After a period of time, those predisposing factors for "cross-infection" have disappeared, and the same conditions, or even the piece of material, can be cut.

XIV. The appearance and observation of "flower filaments"

Due to arc discharge, short circuit, open circuit, and carbon pellets, the pulse source ammeter can swing significantly. Discharge sparks will appear red, yellow, and white. The black spots formed at the beginning are thickened by heat burning and carbonization, and pass through the gap and ablate several times and then become thinner. Heating and tensioning for a period of time also naturally thins the dark spots. Brittleness is caused by burning red and cooling and causing serious carbonization. Because the "flower filaments" formed on the silk tube are very easy to regularize, many people try to find out the laws. The result is not the same as the circumference of the package, the circumference of the guide wheel, and the distance between the conductive block and the other. If there is regularity, it is the distance from the point of burn to the exit of the workpiece.

Fifteen, "Filament" solution and analysis

Once the "filament" phenomenon has occurred, we must start with the three elements of the cause. First of all, to confirm the quality of the pulse generator, as long as there is no DC component that prevents arcing, it usually does not cause thread breakage. Second, we must pay attention to water, dirt, rare earth, and less effective components, certainly not; containing a certain amount of salt, alkali and other components that hinder dielectric insulation is even more difficult. Once again, we must pay attention to the fact that thin materials are all good. Even if there is an incentive to pull an arc burn, the exchange of water is quick, and the elimination of impurities and impurities is easy to eliminate. Thick, the incentive to pull the arc burn is very easy to produce and extremely difficult to discharge. In particular, with the oxidation of black skin, forging sandwich, raw materials quenched without quenching and tempering, resulting in a "flower filament" the chance is very high. After the "filigree" material, silk, and water have only one of them, the possibility of "filigree" is still high.

If you can't help but can only cut this piece of material, then completely change the wire, change the water, wipe the machine tool; material sandwich, quenching has no way, at least remove the surface oxidation black skin clean; avoid the cut that has been cut. With large pulses, large pulse widths, small currents, and high voltages, the current can be gradually increased when the stability is only slow, but it is still limited to 2.5A.

There will be a major factor at the beginning of the "flower filament", but because of the "cross-infection", no one will be responsible for the change. Anxious to change the same, try again, change again, try again, it is not spirit, corrupted, wasted things, did not solve the problem. The key to solving "flower filaments" is to "quietly analyze and find out the reasons for the occurrence of the first black spot, change the three basic conditions as well as possible, avoid the incentives as best as possible, and do not be afraid of trouble or hurry, and start from scratch. ".

"Filigree" phenomenon is not a machine tool for many reasons. After determining that there is no fault in the pulse source and there is no abnormality in the clearance tracking, it is necessary to switch to three basic conditions and one incentive to find it. Just to tune the bed, help solve the problem, but also mislead the user, lose their way of thinking, I do not know the reason.

As explained above, I hope to help solve the "filigree" problem.

16. Decrease and elimination of commutation stripe of electrode wire

The main cause of high-speed wire reversal streaks is the uneven cooling state in the slits. In other words, any measures that can improve the cooling conditions in the slits can reduce the occurrence of stripes, if only the molybdenum wire is short and frequent. Switching to cover up the stripes will greatly reduce productivity. It is a visual experience that does not actually solve the problem. The solutions to the problem include: increasing the concentration of coolant to improve the washing performance; increasing the interval between pulses to make the liquid as much as possible; appropriately increasing the pulse width, mainly for building waveforms, adjusting the tracking, etc., but the most important The solution is to choose a good working fluid. I have tested a variety of working fluids. Any liquid that shows an oily surface on the cutting surface indicates that the surface is well cooled. Among them, the Nanguang-1 blended DX-1 and Jiarun series products are the most obvious. DX-4 is also OK, but the surface is yellow, you can use it. Of course, the best situation is when cutting Cr12 material, there is almost no commutator.

17. Suddenly broken wire during cutting

the reason:

(1) improper choice of electrical parameters, current is too large;

(2) Inadequate feed adjustment, sudden change, frequent open circuit short circuit;

(3) improper use of the working fluid (such as the wrong use of ordinary machine tool emulsion), the emulsion is too thin, the use of a long time, too dirty;

(4) The pipeline is blocked and the working fluid flow is greatly reduced;

(5) The conductive block has not been in contact with the molybdenum wire or has been pulled out of the molybdenum wire, causing poor contact;

(6) When cutting thick parts, the intermittent is too small or use working fluid that is not suitable for cutting thick parts;

(7) The performance of the pulse power clipping diode deteriorates, and the negative wave during processing is relatively large, which increases the loss of the molybdenum wire in a short time;

(8) The quality of the molybdenum wire is poor or the storage is poor, oxidation occurs, or the wire is damaged by using an inappropriate tool such as a small iron bar to stretch the wire;

(9) The speed of the storage drum is too slow, making the molybdenum wire stay in the work area too long;

(10) Improper selection of molybdenum wire diameter when cutting the workpiece.

Solution:

(1) Reduce the pulse width, increase the interval, or reduce the number of power tubes;

(2) Improve the operation level, adjust the feed properly, adjust the feed potentiometer, and stabilize the feed;

(3) Use wire cutting special working fluid;

(4) cleaning the pipeline;

(5) Replace or move the conductive block to a position;

(6) Choose a suitable interval and use a working fluid that is suitable for cutting thick parts;

(7) Replacement of clipping diodes;

(8) Replace the molybdenum wire and use the upper wire;

(9) Reasonably select the wire speed;

(10) Select molybdenum wire diameter according to the recommendation of the instruction manual.

18. Broken wire when the workpiece nears the end of cutting:

the reason:

(1) Deformation of workpiece material, pinch off molybdenum wire;

(2) When the workpiece falls, it breaks the molybdenum wire.

Solution:

(1) Select the appropriate cutting route, materials, and heat treatment process to minimize distortion;

(2) When quick cutting is finished, use a small magnet to suck the workpiece or hold the workpiece with the tool so that it does not fall.

Nineteenth, encountered some problems in online processing, after analysis, are summarized as follows:

1. When you are looking for a center, it is always unacceptable. It may be that there are impurities in the hole or the hole itself has not been straightened. If there are impurities in the hole, it can be cleaned up; if the hole itself is processed, it can only be reworked and the center can be found again.

2. When the program is written with the dot as the starting point, it is normal when the graphic is displayed, but it shows that it does not match the edited figure when it is running. This is because it is not necessary to change the starting point option in the parameter setting to 0.

20. The voltage, current, pulse width, and pulse-to-pulse relationships among the pulse parameters are 1) The voltage is increased appropriately, which helps to improve the stability and processing speed and improve the machining accuracy; (2) Increase the pulse current , It also helps to improve the stability and cutting speed, but the surface roughness value increases, the wire loss will also increase; (3) increase the pulse width, not only helps to improve stability and cutting speed, but also helps to reduce Loss of electrode wire, but the surface roughness value increases; (4) reduce the pulse, can increase the processing current and cutting speed, surface roughness value will increase.

Twenty-one, how to do abnormal noise walking silk system?

The abnormal noise of the silking system appears in the following five parts:

1, reversing moments, couplings or keys: At this time we must carefully observe the reasons, replace the keys that have been loosened and weighed, so that it recovers a large area of ​​tight fit; coupling to restore the function of the cushion, so that flexibility The buffer is really effective, these parts can not work long-term sick, otherwise it will cause irreparable consequences.

2. The sound of foreign matter in the package is mostly due to the small metal particles or molybdenum wire entering the package. As long as it is not the balance adjustment in the package, the pin can fall off and it can be operated as usual. Very quickly, small metal particles or molybdenum wire. The head will wear away.

3, the abnormal sound of the belt or gear, to check whether the belt or gear has been excessive wear and tear, should be promptly replaced, such as due to improper meshing gap, it is necessary to timely adjust the bite gap.

4. The wire spool runs to the lead screw and bears excessive load force to cause friction or impact noise. The relevant parts will be destroyed soon. The abnormal phenomenon at this part should be checked carefully until it is eliminated.

5, wire drawing motor blade or its own dynamic balance.

Twenty-two, how to determine broken wire protection spirit

Broken wire protection function is achieved by *KA2 small relay, 12V DC power supply is connected to KA2 by molybdenum wire between two electric blocks on the wire frame, and KA2 is pulled in. When there is no molybdenum wire between the two electric blocks, KA2 will disconnect. The two electrical blocks are connected in parallel with a pair of contacts on the “broken wire protection” switch on the button disk, and the “broken wire protection” switch plays the role of whether to replace the molybdenum wire. The molybdenum wires between the two electric blocks or the “broken wire protection” switches all play a role in KA2 pull-in. A pair of normally open contacts of KA2 are connected in the control circuit of the main switch contactor KMI, and KA2 loses power. , KMI power off, cut off the power of the machine. When there is no molybdenum wire, the “broken wire protection” switch determines whether the KMI can pull in. When the two power blocks are short-circuited by the molybdenum wire, the “break wire protection” switch can be switched off even if the switch is off. If the molybdenum wire is manually disconnected from contact with an electric block, the entire machine is immediately powered off. Here, it should be explained that the contact between the moving molybdenum wire and the fixed electric inlet block is not a very stable connection, and sparks on the electric block may even be a malfunction of the KA2. This * adjusts the degree of contact of the molybdenum wire in the electric block, so that there is a good electrical contact and does not cause excessive resistance. At the same time, the insulation between the electric block and the bed and the cleaning and stability of the electric block are also very important. In order to achieve the sensitive and effective protection of broken wire, the adjustment and cleaning of this part is of course very important.

Twenty-three, stepping motor

There are straight-pulling methods and differential gears for the linear cutting machine. The selection of the straight-pulling motor can be a servo motor, and the stepping motor is selected for the differential gear. The three-phase and five-phase of the stepping motor are more commonly used. .

The drive current of each phase of the stepper motor must be balanced to ensure that the motor drives the carriage according to the normal phase sequence. The X, Y phase sequence indication LED on the control panel is a kind of monitoring of the running status of the stepper motor. If a status LED is off or not flashing, it indicates that the phase is not working. In some cases, the status LED indicates normal, but the stepper motor shows in situ jitter and does not operate normally, which means that the stepping motor is in a phase-off state and is simple to determine. Method, you can use the table to measure the motor's phase voltage is normal (consistent) ------ can find the fault point.

Twenty-four, silk can not open

Inspection Method:

1. First, check if there is a relay to pull in. If there is a relay that releases with the cartridge switch, check the three-phase power supply circuit, whether the motor is two phases, whether the fuse is bad, and whether the relay contact is in good condition.

2. If there is no relay pull-in, there is a problem with the relay control circuit. The relevant components are: a. Torch switch button b. Machine stop button c. Special attention should be paid to the fact that our company's products also have a tight stop button on the controller. If this button is pressed, the machine tool spool is not openable. In addition, there is a limit switch on the machine tool electrical board, only the machine tool board pushes. In the end, the switch is turned on and the machine can work.

Twenty-five, silk tube does not change direction

Inspection method: The reel change involves two (or one) relays in the wire barrel limit switch and the machine tool electrical appliances. In general, the possibility of a bad trip switch is greater, as long as the limit switch can be used, pay attention to the top two of the limit switch. For the commutation of the package, the third one is used for reversing high frequency (some models do not have), and the fourth is the stop switch

Twenty-six, press the pump switch (or press the high frequency switch) the machine stops

Inspection Method:

1. The broken wire shutdown function is connected to the machine tool of our company. According to the water pump switch (or high frequency switch), the molybdenum wire must be put in first, and the molybdenum wire machine tool is not considered to be broken, that is, the machine stops immediately.

2. The wire breakage line is connected to a certain reference seat. The introduction must be metal introduction. If the wire is broken or the guide wheel is replaced with a ceramic guide wheel, it will not work.

3. There is two triodes on the board in the machine tool board, which is generally easy to be broken and can be replaced by the model.

Twenty-seven, machine tool X, Y carriage (or U, V carriage) are out of step

Inspection Method:

1. This situation is generally caused by a low stepping motor's 24V power supply. Check if the 10000uf electrolytic capacitor has failed and if there is a problem with the 24V bridge rectifier.

2. If the external power supply is too low, it will cause a loss of synchronization. Check if the controller power is normal. Consider using a 220V regulator.

Twenty-eight, the machine tool out of step or jitter does not go check method:

1. Replace the ring drive board to determine if it is a problem with the drive board. If there is a problem with the drive board, the 3DD 15A or 3DK106B board is generally broken.

2. Observe the stepper motor indicator on the single board machine. There are three lamps in one direction. Flash alternately during operation. If one lamp is always on or off, there is a problem with the single board machine. Check the interface board 3DK2B or 74LS08 or single board machine. PIO chip is damaged.

3. There is a row of resistors at the bottom of the controller, which is the current limiting resistor of the stepper motor. If one of the resistors is broken or the contact of the terminals is not good, it will cause out of step or not.

4. The stepper motor may also have problems and can be judged in exchange.

Twenty-nine, no high frequency

Inspection Method:

1. Whether the high-frequency power supply has been energized or not, there is a relay in the high-frequency circuit that moves along with the spool, or there is a check button on the high-frequency power supply of the machine tool, which can check whether there is a problem with the high frequency, first check the oscillation board, and then drive the board. Whether the working voltage is normal or not, there is a problem with the power board. Generally, there are several groups of high-frequency driving boards that can be swapped to determine whether it is good or bad.

2. The commutation relay has a set of normally closed contacts connected in series in the high frequency control loop. If it is not good, there is no high frequency. Some machine tools specifically have a commutation broken high frequency switch to check.

3. There is a 3DK106 B on the board interface board for high-frequency output control. Check if it is damaged.

Thirty, manually go without going automatically

Inspection Method:

1. First, determine if there is a high frequency, and let the workpiece and the molybdenum wire touch. There is spark to indicate that the high frequency is no problem, no spark is no high frequency, see the above solution.

2. There are two leads at the clamp workpiece, the rough one is high voltage (ie high frequency output), the thin one is the sample input wire, and this wire is broken automatically

31. Short-circuit processing method in wire cutting

During on-line cutting machine processing, short-circuiting due to chip evacuation often occurs, especially when machining thicker workpieces.

In operation, the solution can be used to eliminate short-circuiting. The specific method is: when the short-circuit occurs, first turn off the automatic, high-frequency switch, turn off the working fluid pump, use the brush to pick up the strong permeability of gasoline, kerosene Ethanol and other solvents repeatedly penetrate the molybdenum wire moving on both sides of the workpiece into the slit (note the direction of movement of the molybdenum wire). Until the use of screwdrivers and other tools gently touch the molybdenum wire in the opposite direction of the workpiece at the bottom of the workpiece, the molybdenum wire at the top of the workpiece can move. Then, the working fluid pump and the high-frequency power supply are turned on, relying on the moire of the molybdenum wire to restore the discharge and continue processing.

Thirty-two, in-situ threading after broken wire

The stepper motor should remain in the “suction” state after the wire is broken. Remove the waste wire on the lesser side and adjust the remaining molybdenum wire to the proper position on the wire storage tube to continue using it. Because the workpiece kerf is filled with emulsion impurities and electrocorrosive substances, the surface of the workpiece must first be wiped clean, and kerosene is firstly dripped with a brush in the slit to make it wet and then cut off. It's important to drop a bit of oil at this point. Choose a relatively straight molybdenum wire, cut into pointed tips, and use a lighter flame to roast this piece of molybdenum to make it hard. Use a medical tweezers to pinch the upper part of the molybdenum wire. Gradually, slowly cut the slit along the slit. Send 2-3mm each time until it passes through the workpiece. If the original molybdenum wire cannot be used anymore, replace the new wire. The new yarn is worn at the broken point. It depends on the degree of loss of the original yarn. (Be careful not to lose too much.) If the loss is large, the slit will also become smaller, and the new yarn will not pass through. Then a small piece can be used. Spinning paper smooths the part of the wire that will go through the work piece and can be worn again. Using this method can greatly improve the efficiency of machine tools

Thirty-three, solve the problem of large thickness "copper pieces" cutting broken wire

Because the copper pieces are different from other steel materials, when the thickness exceeds 50 mm, if the operator still processes the electrical parameters used when processing the steel materials, the cutting speed, current instability, frequent short-circuits, and broken wires will occur. . The corresponding measures to be processed normally include:

(1) Do not use emulsions that have been used for a long time. Try to use new emulsions. And it is best to use JR-1A, JR-3A, JR-4, Nanguang-I working fluid. Because the copper material is sticky, the impurities in the old emulsion are hard to be washed out, and the conductive properties of the copper during processing are also affected. The use of new emulsion can avoid the above phenomenon. In addition, the above-mentioned recommended working fluid has better electrolysis performance and a wider slit, which can improve the chip removal condition in the slit. At the same time using a higher wire speed favors chip removal.

(2) Eliminating the current short circuit phenomenon, when the copper inclusions appear in the cutting line, the stability of the processing current will be affected, so that the short circuit phenomenon often occurs, and if it is not properly processed, the wire will be broken. The use of high-current, large-pulse-width processing increases power. Relying on the energy of the pulse to break through the relatively small inclusions allows processing to proceed normally. At this time, special attention should be paid to the increase of the time between the pulse and the increase of the rest time. At the same time, the large pulse width ensures that the discharge energy will not be lost due to the good heat transfer of copper.

(3) Since the copper material has good thermal conductivity, if narrow pulse width processing is used, the energy emitted by the power source will be quickly transferred by heat during the action of the narrow pulse width, so that the cutting will occur. Phenomenon, so the copper must be cut with a larger pulse width, generally need to use more than 40μs pulse width.

(4) Pay attention to the loading direction. The shortest side of the cutting path should be stuck in the third direction, that is, the X negative direction, so that the molybdenum wire can go as little as possible in the negative X direction, which can reduce the chance of broken wire.

(5) When the work is stopped, use kerosene to clean the wire on the silk tube again, so that the anti-stained copper foam on the molybdenum wire is greatly reduced, and the effect will be better when the next time the power is turned on.

Thirty-four, how to judge the quality of the working fluid used and whether it has reached the service life

At present, the use of special emulsified oil for wire cutting still accounts for most of the market. The emulsified oil for wire cutting is actually an improved product from ordinary emulsified oil. Under the condition that the general cutting requirements are not high, it shows a strong Versatility, but as the cutting thickness of the workpiece increases, the cutting taper increases, the cutting fee per unit area decreases, and the proportion of difficult-to-machine materials (cementoy, magnet steel, and copper) increases, the original general line cutting special emulsified oil Can not fully meet the cutting requirements. The general performance of the working fluid should have the following characteristics:

★ It can use larger energy for stable processing. Under normal machine conditions, the average machining current for workpieces up to 100mm, such as 60mm, can reach or even exceed 2.5 - 3A (amperes). Under this condition, the unit current is processed. The efficiency should be greater than 25mm2/min.A, ie at a processing current of 3A, the processing efficiency should reach 75 - 80 mm2/min. And it can cut the work piece with larger thickness (200 - 300mm) with a smaller duty cycle.

★ During the processing, there will be more electrocorrosion products (black ink) at the outlet of the workpiece. The ribbon will be out of the electrode and even bubbles will appear. This shows that the cleaning performance of the working fluid in the slit is good and the cooling is even and sufficient.

★ Cut the workpiece should be easy to remove, the surface color is uniform, silver white, lighter or less directional stripes.

The concept of the service life of the working fluid does not necessarily have a clear concept, because most operators use the method of continuously replenishing water and raw liquids. This method will shorten the service life of the working fluid and increase the cost.

Usually a box of working fluid (in terms of 40 liters) has a normal service life of about 80 to 100 hours (ie about one week). Exceeding this time, the cutting efficiency may be greatly reduced. That is, the criterion for the working fluid life is the processing efficiency. Generally, the processing efficiency is reduced by more than 20% as a basis for whether the working fluid should be replaced.

The working fluid with good performance has good chip removal performance and fast cutting speed. Naturally, it is relatively easy to blacken. However, the blackened working fluid does not necessarily reach the end of its useful life. Therefore, the criterion for using the working fluid color as the service life is inaccurate.

Thirty-five, about the experience of line cutting water change

Add 20% milk solution. Add %76 water. Add 2% of motor oil. Add %1 detergent. Add %1 suds. Exclusion is very good. Good finish

36. Preparation of Quick Cutting Wire Working Fluid

The working fluid for wire cutting is made of special emulsified oil and tap water. It is better to use distilled water or magnetized water and emulsified oil to prepare the working fluid. The concentration of the working fluid is determined by the thickness, material and processing precision of the workpiece.

From the workpiece thickness point of view, the thickness of the workpiece is less than 30mm thin, the working fluid concentration between 1O% to 15%; 30 ~ lOOmm thick workpiece, the concentration of about 5% to 1O%; thicker than 1OOmm The workpiece has a concentration of about 3% to 5%.

From the viewpoint of the workpiece material, materials that are easily eroded, such as materials with low melting point and low latent heat of vaporization such as copper and aluminum, can appropriately increase the working fluid concentration to fully utilize the discharge energy and improve the processing efficiency, but at the same time, larger diameters should also be selected. The electrode wire is cut to facilitate full chip removal.

From the point of view of processing accuracy, the concentration of the working fluid is high, the discharge gap is small, and the surface roughness of the workpiece is good, but it is not conducive to chip evacuation and is likely to cause a short circuit. When the concentration of the working fluid is low, the surface roughness of the workpiece is poor, but it is advantageous for chip removal.

In short, in the preparation of line cutting work fluid should be based on the actual processing of the situation, comprehensive consideration of the above factors, in order to ensure smooth chipping, processing premise, as much as possible to improve the quality of the processing surface.

Thirty-seven, wire cutting machine operation precautions

1. The operator must be familiar with the structure and performance of the machine tool and must be qualified before training. Non-line cutting personnel are forbidden to use automatic wire cutting equipment. It is forbidden to use wire cutting equipment with super performance.

2. Pre-operation preparation and confirmation

1) Clean up the waste materials and impurities in the work surfaces and work boxes, and do a good job of "5S" work on the machine and around.

2) Check if the working fluid is sufficient. If it is insufficient, add it in time.

3) When there is no machining or precision machining, check whether the electrode wire allowance is sufficient and sufficient. If it is insufficient, replace it.

4) Check the amount of waste wire in the waste wire barrel. If it exceeds 1/2, it must be cleaned in time.

5) Check if the inlet pressure of the filter is normal and whether the compressed air supply pressure is normal.

6) Check whether the interpolar lines are dirty, loose or broken, and check if there is any interference between the interpolar lines when moving the table.

7) Check the wear of the conductive block, change the position of the conductive block when it is worn, and clean it when there is dirt.

8) Check whether the running of the pulley is stable, whether the operation of the electrode wire is stable, and check if there is a jump.

9) Check whether the electrode wire is vertical. Straighten the verticality of the electrode wire before processing.

10) Check if the lower guide is loose and the upper guide is open and closed smoothly.

11) Check whether the nozzle has a defect; if the lower nozzle is lower than the working table 0.05 ~ 0.1mm.

12) Check whether the relevant switches and keys are sensitive and effective.

13) Check to see if the machine is operating properly.

14) When it is found that the machine tool has an abnormal phenomenon, it must be reported in a timely manner and wait for processing.

3, workpiece clamping note

1) Clean the rust residue and impurities before the workpiece is clamped.

2) The mounting surface of the cutting work piece such as the template, plate, etc. is to be dressed and polished with whetstone before being clamped to prevent the unevenness of the surface, affecting the accuracy of the clamping or interference with the lower nozzle.

3) The workpiece clamping method must be correct to ensure that the workpiece is straight and fast.

4) Do not use sliding screws. The screw lock depth should be more than 8mm, the locking force should be moderate, not too tight or too loose.

5) The clamp should be clamped flat to ensure that the clamps are evenly balanced by force.

6) Be careful during the clamping process to prevent the workpiece (plate) from falling down.

7) The position of the workpiece clamping should be conducive to the alignment of the workpiece and it is compatible with the stroke of the machine tool, which is conducive to program cutting.

8) After the workpiece (plate) is clamped, it must be checked again to see if it interferes with the nose and interpolar lines.

4. Precautions when processing

1) When moving the table or the main shaft, it is necessary to correctly select the moving speed according to the distance from the workpiece, and to prevent the collision when the movement is too fast.

2) During programming, the correct processing technology and processing route should be determined according to the actual situation, and the workpieces caused by insufficient processing positions or insufficient strength of cutting edge should be eliminated or cut off in advance.

3) Before the line cutting, it is necessary to confirm whether the program and the compensation amount are correct.

4) Check if the wire tension is sufficient. When cutting the taper, the tension should be reduced to the usual half.

5) Check if the feed rate of the electrode wire is correct.

6) According to the actual situation of the workpiece to be selected open processing or close processing, in the premise of avoiding interference to minimize the distance between the nozzle and the workpiece. For close processing, the distance between the nozzle and the workpiece is generally 0.05 to 0.1 mm.

7) Check whether the choice of jet flow is reasonable, use high-pressure jet flow for rough processing, and use low pressure jet flow for fine processing.

8) When cutting, attention should be paid to observe and judge the processing stability, and if it is found to be bad, adjust in time.

9) During the processing, check and supervise the cutting conditions frequently and find that the problem is dealt with immediately.

10) If an abnormal short-circuit or abnormal shutdown occurs in the machine tool during machining, the real cause must be found and the correct treatment must be performed before continuing processing.

11) When processing is suspended due to a disconnection or the like, after processing, it must be confirmed that there is no interference before processing can continue.

12) Modify the machining condition parameters must be within the allowable range of the machine tool.

13) It is forbidden to touch the electrode wire and the cut object during processing to prevent electric shock.

14) Work should be done to prevent the process fluid from splashing out of the work box.

15) It is forbidden to rely on the machine tool box in processing so as not to affect the machining accuracy.

16) Before cutting off the waste or workpiece, it should wait for the machine to observe, and immediately shut down the processing when cutting off. Note that the waste or workpiece must be removed before moving the workpiece table.

5, other matters needing attention

1) The opening and closing of the machine tool must be performed in accordance with the relevant provisions of the machine tool. It is forbidden to operate in violation of regulations and to prevent damage to electrical components and system files.

2) After the machine is turned on, it must be performed back to the origin of the machine tool (the electrode wire should be cut off first), so that the machine tool calibration is consistent.

3) When removing the workpiece (sheet), care must be taken to prevent the workpiece (plate) from falling.

4) After the processing is finished, clean up the workpiece surface and the debris in the work box in time, and do a good job of the "5S" work of the machine tool and its surroundings.

5) The fixtures and workpieces (plates) should be well-prevented and placed in the designated position.

6) Make necessary records after processing.

38. Wire-cut computer on-line optically isolated transmitter (will never burn the print port and main board: 100% stable transmission)

It solves the problems of the traditional connection being susceptible to interference errors, frequent damage to the computer and the machine console, and the inability to send the number over long distances.

The drawbacks of answering transmission methods:

When the wire cutting controller and the wire cutting software use a computer for online transmission, they are divided into synchronous transmission and response transmission, that is, synchronous receiving and response receiving for the single board machine.

光电隔离器主要是针对于应答传送与接收的，因为只有应答式的单板机存在这问题(原因在于应答式的单板机中没有进行光电耦合与限流措施)。现在国内生产应答式的单板机厂家大部分是在上海，宁波，江苏(因为它们是比较早的线切割生产基地，虽然是生产基地，但应答式的技术是源于电报头输入原理，这是非常落后的，过时的技术，随着电子与电脑硬件不断地升级，但线切割控制器系统单板机却没有随之更新，也许是它们根本解决不了这问题，所以在传送程序过程中出现了：烧电脑打印口，联机有困难等问题)

在应答传送与接收时，单板机都需要一定值的电流输出到电脑打印口上以表示通讯握手信号，这样电脑打印口就会存在被烧坏的可能性(烧掉后，就不能传送3B程序)，有些用户还经常进行单板与电脑联机传送线的热插拔，还有在打雷的时，这些都是导致烧打印口。

光电隔离器：

为了解决应答传送时：“烧打印口或主板，不稳定传送完毕”问题，我们设计了线切割电脑联机光电隔离传送器，进行光电耦合与限流，从而安全稳定的直接与电脑打印口连接传送3B程序(现在我们增加了串口传送功能：直接用串口来代替电脑打印口，这样来增加传送的稳定性，稳定性保证100%)。光电隔离器的原理：与"只进不能出"的阀门一样(单向止回阀)，就是由电脑向单板机输出3B程序，而当单板机向电脑输出电流时，就由光耦进行隔离，用电阻进行限流，从而彻底起到保护电脑打印口，如果用串口通过光电隔离器传送到单板机，那就可以做到永远会烧电脑主板及100%稳当传送，单板机100%的接收：这是我们向每位客户的永久保证。

串口+光电隔离器à单板机通讯口：

1. 稳定性提高到100%，高效智能，保证您的代码传输之路畅通无阻。

2. 通讯线路不再受长度限制，可随意向美观方面安装，使生产现场简洁明亮，传送线缆的长度可以增加到50米至100米。长距离传送程序稳定准确，电脑因此可放在合适的工作环境中使用(例如放在办公室，便于生产上的管理);

3. 大大减少传送过程中存在的干扰性，几乎为零，确保传送100%。

4. 分低电平，高电平有效电压传送，同步及应答式通讯口兼容，适合多种不现的控制器，不同厂家和型号的机床都可同时联机，不需改动机床的任何线路。

5. 放弃使用传统的屏蔽线理论，避免因接地不良或设备绝缘问题所潜在地回路引起的设备安全;

6. 安全、耐用、稳定。消除了因电磁干扰、机床故障、电源不稳定等外因而造成烧毁电脑并行口和控制台接口电路的危险因素;

型号与规格：

1、A型--直接传送器——1个端口(直接可连接1台机床，加转换器可增加到4台)

2、B型--直接传送器——8个端口(可同时连接8台机床)

三十九、专业小知识：

使用传统的应答联机，等于电脑与机床电气相通，其缺点表现在：

1、送数时经常出错停机，程序段数较多时根本无法完成传送;

这是因为电脑和机床控制台是由集成电路和电子电路组成，内阻较高，极容易感应到干扰信号，生产现场各种各样的机床在运转时本身也是一个干扰源，

通过电网回路进行干扰，影响了程序的传送。

2、经常烧毁电脑并行口和控制台接口电路;

当干扰能量足够大，或者经常带电拔插通讯插头，或机械转换器开关不良，就会形成瞬间高压，攻击设备;机床数量越多，损害程度越高;最后的结果：

就是要更换电脑和机床控制台。

3、由于干扰的缘故，电脑必须与机床最近的距离使用;

生产场地环境较差，而家用电脑并无防尘、防湿、防干扰等措施，所以造成电脑的故障大增。

调查发现，上述的情况在用户中很常见。

程序传送器，既是保护器，又是稳定准确的通讯器，联机的一切问题都会迎刃而解!